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BACKGROUND
[0001] This invention relates to techniques for presenting media to a group of users in an online environment. In today's work environment where people often work in offices located in different cities, it is common to do various types of media presentations, such as slide show presentations, using various types of computer networks, such as Intranets or the Internet. Typically, the presentations are done in conjunction with a telephone conference call, so that the participants can listen to and ask questions to the presenter.
[0002] In some cases, the slides used in the presentation are distributed to all the participants before the presentation, for example, through e-mail or by downloading the slides from a server to the participants' computers. During the presentation, each participant views her own copy of the slides on her computer using some kind of slideshow presentation software, for example, the PowerPoint® software application which can be obtained from Microsoft Inc. of Redmond, Wash. A challenge to this approach is to keep the slides synchronized amongst the participants during the presentation. Typically, the moderator must tell the participants whenever he changes slides and verbally state what slide he is on. If a participant were to miss a slide number announcement, he may get confused and not realize that the presenter is talking about a different slide.
[0003] In other cases, no slides are provided to the participants in advance of the presentation. Instead, some kind of web conferencing solution is used. One commonly used web conferencing system is provided by WebEx Communications Inc. of Santa Clara, Calif. In the web conferencing solution, the presenter and participants register with a web service, and during the presentation a bitmap representation of what is shown on the presenter's computer screen is transmitted to all the participants in real time and displayed in a web browser. That is, no special software is required to be installed on the presenter's or participants' computers. However, the participants lack the ability of going back and forth between slides as the presentation is going on, and can only view the slide that is currently selected by the presenter.
SUMMARY
[0004] In general, in one aspect, the invention provides methods and apparatus, including computer program products, implementing and using techniques for synchronizing a media presentation. A locally stored electronic copy of the media presentation is displayed on a presenter's presentation device and a locally stored copy of the media presentation is displayed on each of one or more participants' presentation devices. The presenter's presentation device and each participant's presentation device is operable to communicate with each other through a communications network. In response to the presenter performing an action on the electronic copy of the media presentation on the presenter's presentation device during the media presentation, data pertaining to the action is transmitted through the communications network to each participant's presentation device. The appearance of the media presentation on each participant's presentation device is changed in accordance with the data transmitted from the presenter.
[0005] The invention can be implemented to include one or more of the following advantages. The participants know at all times what slide the presenter is referring to. Only a small amount of information is sent through the computer network to the participants, thereby preserving valuable bandwidth. The presenter can obtain information in real time, or after the presentation, about what slides individual participants, or the group of participants as a whole, spent most or least time on. The presenter can highlight sections of individual slides to indicate to the participants what section of the slide is being discussed. The control of the presentation can be handed off, temporarily or permanently, from the moderator to one of the participants. It is easy for all participants to be redirected to a particular position in the presentation. The presenter can at any time relinquish control to one of the participants. The presenter can be informed when all users have advanced to a particular portion of their respective local copies of the presentation.
[0006] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0007] FIG. 1 shows a flowchart of a process for performing a media presentation in accordance with one embodiment of the invention.
[0008] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0009] Embodiments of the invention will be described below by way of example and with reference to a slide show presentation. It should, however, be noted that the various embodiments of invention are not limited to slide show presentations only, and that the concepts described herein can be applied to other types of media, such video or various types of electronic documents, that is to be shared among a group of users. Furthermore, the operations described herein can be performed by a stand-alone software application, or be integrated partly or entirely in a slide show presentation software application. In the following description, it is assumed that each participant's computer, as well as the presenter's computer is connected to a computer network, such as an Intranet or the Internet, through a wired or wireless connection, such that information pertaining to the presentation can be exchanged between the presenter and the participants through the network.
[0010] As shown in FIG. 1 , a process ( 100 ) for performing a media presentation, in this illustrative example a slideshow presentation, in accordance with one embodiment of the invention starts by an individual copy of the slideshow presentation being distributed to each participant who plans to view the slideshow presentation (step 102 ). The participants can either be selected by the presenter, or sign up to view the presentation in response to a general announcement or invitation, using mechanisms that are well known to those of ordinary skill in the art. This typically occurs some time before the time of the presentation, but in some implementations it is also possible for tentative participants to view a list of ongoing presentations that are available to them on their network, and instantaneously sign up to join the presentation as a participant. In some implementations, a publish-subscribe system is used, which allows the presentation software application to connect to a presenter's calendar system on his computer to obtain a list of the participants of the presentation from a calendar entry. Alternatively, the presenter can manually enter the IP address for the participants. The distribution of the slide show presentation to the participants can be done by any conventional means, such as, for example by e-mail or by the participants downloading the slideshow presentation from a server connected to the computer network.
[0011] Next, the presentation is initiated (step 104 ). This step typically involves the presenter and each participant opening their personal copy of the presentation in some kind of slideshow presentation software application, such as the PowerPoint® application or a similar application. The participants' slideshow presentation software application (or their stand alone application) allows the participant to synchronize their slides with another user, in this case the presenter, by simply selecting that user from a drop-down list or other type of menu. The software then subscribes to that user's activity. An audio connection is also established so that the participants and the presenter can hear each other. In one implementation, the audio connection is established by the presenter and the participants joining a telephone conference call. In other implementations, the audio connection is established using voice over IP (VOIP) technology, such that no separate telephone connection is needed between the presenter and the participants. Instead, the audio is transmitted over the computer network along with the slideshow information.
[0012] The process then keeps checking whether the presenter has selected a new slide (step 106 ). When a new slide is selected by the presenter, slide information is distributed to the participants (step 108 ). In a simple embodiment, when the presenter changes slides, the software broadcasts an integer indicating the new slide number to the participants. The presenter's slide number can then be shown in a particular location on a participant's computer display, or a popup window can be displayed, in which the participant is asked to advance to the next slide. In more sophisticated embodiments, the new slide number is received in the participant's slideshow presentation software, where it automatically triggers the software application to display the same slide that the presenter is viewing. Regardless of which embodiment is used, this allows the participants to always stay current with what slide the presenter is talking about during any point of the presentation, which significantly reduces the chance of confusion among the participants. Furthermore, in all of these implementations, a very small amount of information is passed through the computer network compared to the bitmap images that must be transmitted during web conferencing presentations.
[0013] In some implementations, more sophisticated actions pertaining to the slides can be distributed from the presenter to the participants as well. For example, the presenter may highlight some text on a slide, rearrange the order of the slides, or perform some other kind of operation that affects the content of one or more slides in the presentation. This information can be broadcast as metadata to the participants in addition to the slide number information, and be reflected on their computer screens. For instance, in the case of highlighting text, a unique identifier can be passed that corresponds to the text box object, as well as displacement integers that describe what portion of the text is highlighted.
[0014] Some embodiments of the invention optionally allow the participants to provide feedback to the presenter (step 110 ). This feedback can take several forms. For example, in its simplest form, the control of the slideshow presentation can be temporarily relinquished by the presenter and passed on to one of the participants who may have questions about a particular slide. For example, consider Alice who is presenting a slideshow presentation to the participants Bob and Charlie. If, during the presentation, Bob says to Alice “Wait a second. What about this previous slide you talked about?” Alice, with a click of a button, can view on her slideshow software what slide Bob is currently viewing. Bob doesn't actually have to tell Alice what slide number he is viewing. Alice can also agree to temporarily give Bob control of the presentation, so that he can select specific areas of the slide that he is asking questions about.
[0015] Another type of feedback that can be provided to the presenter is statistical information pertaining to which slides the participants are viewing at any given instance during the presentation. For example, in the above example, Alice may want to keep track of what all the participants are viewing. A portion of Alice's computer screen can be dedicated to a grid of slides where she can see what slide Charlie, Bob, and others are viewing. In some implementations, this information can also be recorded and processed after the presentation is concluded. For example, if Alice is presenting to a remote audience of hundreds of participants she may want to view statistics of what slides where most viewed, or what slides the participants spent the most time viewing, which may give her an indication of which slides are most interesting to her audience.
[0016] Finally, the process checks whether all slides are done (step 112 ), that is, whether the presentation is finished. If all slides are done, the process ends, otherwise it returns to step 106 to determine whether the presenter has advanced to a new slide.
[0017] In some embodiments, the entire presentation can be saved and replayed at a later point in time. This is particularly useful for participants that are unable to attend the live presentation or who can only attend a portion of the live presentation, as it allows them to still obtain the same information at a later point in time. In one embodiment, the presentation is saved as an audio file that contains slide changing queues. This enables a participant to play the audio file and the locally saved copy of the presentation or slideshow will change to reflect the time the presenter spent on each slide.
[0018] The invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. In a preferred embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc.
[0019] Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
[0020] The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk—read only memory (CD-ROM), compact disk—read/write (CD-R/W) and DVD.
[0021] A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution.
[0022] Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers.
[0023] Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters.
[0024] A number of implementations of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the invention has been described above by way of example of the participants using computers to view the presentation. However, any type of device capable of displaying a presentation, such as a PDA (Personal Digital Assistant), mobile telephone, or other types of electronic communication devices can be used. The participants have been described above as being identified by IP addresses of their devices, but it is also possible to identify participants' devices through other methods, such as, RFID (Radio Frequency Identification) tags or Bluetooth devices that know they are near a device that is somehow associated with the presentation, for example, close to a telephone that will be used in the presentation, or inside a conference room that will be used for the presentation. Accordingly, other embodiments are within the scope of the following claims.
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Methods and apparatus, including computer program products, implementing and using techniques for synchronizing a media presentation. A locally stored electronic copy of the media presentation is displayed on a presenter's presentation device and a locally stored copy of the media presentation is displayed on each of one or more participants' presentation devices. The presenter's presentation device and each participant's presentation device is operable to communicate with each other through a communications network. In response to the presenter performing an action on the electronic copy of the media presentation on the presenter's presentation device during the media presentation, data pertaining to the action is transmitted through the communications network to each participant's presentation device. The appearance of the media presentation on each participant's presentation device is changed in accordance with the data transmitted from the presenter.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of U.S. patent application Ser. No. 09/418,090 filed Oct. 14, 1999 and issued as U.S. Pat. No. 6,405,430, which is a continuation of U.S. patent application Ser. No. 09/146,702 filed Sep. 3, 1998 and issued as U.S. Pat. No. 6,029,329, which is a division of U.S. patent application Ser. No. 08/598,148 filed Feb. 7, 1996 and issued as U.S. Pat. No. 5,907,902.
BACKGROUND
1. Field of the Invention
The present invention relates generally to the continuous handling of material for processing. More particularly, the present invention relates to a belt feed machine for trimming and forming leads on semiconductor electrical components.
2. Description of the Invention Background
Solid state electrical devices are typically connected to other devices, as well as common substrates, such as printed circuit boards, through the use of electrical connectors, or leads, that are attached to input and output contacts on the device. The quality of the electrical connections between the devices depends upon the proper formation and positioning of the leads and the proper placement of the device.
The individual electrical devices are typically mass produced on common semiconductor substrate, or wafer, which is subsequently cut up to separate the individual dies. Electrical leads are attached to the dies as part of a preformed lead frame in which the leads are flat members extending from a common paddle. The leads are subsequently trimmed from the lead frame and formed to the desired shape after attachment to the die. Lead frames are often produced as a series of individual frames, each containing electrical leads for attachment to a die. The formation of multiple devices in a single lead frame or strip provides for easier handling of the lead frame during processing. In addition, the lead frames typically contain indexing holes for use in handling and alignment of the lead frame during subsequent processing. After the leads are attached, the devices are typically encapsulated in a molding compound to protect the device from moisture and other deleterious environmental conditions. The lead frames also contain dambars that are attached perpendicularly to the leads to provide structural support to the leads during processing and to prevent molding compound that extrudes from the mold during the encapsulation, known as flashing, and accumulates between the leads from flowing onto the portion of the leads to be attached to another component or onto adjacent devices.
After the plastic encapsulation of the device, the flashing and the dambars must be removed from between the leads. In addition, the electrical leads must be disconnected from the lead frames, trimmed and formed to a desired shape. Finally, the individual devices must be separated from the lead frame to yield the finished product. Each of these processes is generally performed through the use of die and punch tooling.
In the prior art, specially dedicated machines were used to perform each of the die and punch operations. The strips of lead frames would be processed in one machine for a given step and then transported to another machine to further processing. However, the transporting of the strips between machines and the required overhead with loading and feeding strips to the machines greatly increased the processing time and lowered the yield of the devices due to higher incidence of damage. Many of the problems with the use of the individual machines were overcome with development of integrated machines that can be used to perform a series of tooling operations on the framed device in one machine. In those machines, the die and punch tooling operations are linearly arranged in tooling stages and the frames are moved serially through each tooling operation.
The integrated machines use a “walking beam” method to advance the frames through the various stages. In a walking beam method, the strip is horizontally oriented and fed into a track at the inlet of the machine until the indexing holes which the initial position of the first finger of the walking beam and are engaged from above by the first set of pins extending from the first finger. The track supports the frame while leaving both sides of the device exposed and guides the strip through the machine as the strip is advanced by the fingers of the walking beam. Actuation of the beam causes the finger to move the lead frame to the first tooling stage. In the tooling stages, the punch tooling is reciprocated to contact and push the lead frame from above so as to disengage the lead frame from the pins on the walking beam finger and to push the lead frame onto the alignment pins attached to the stationary die. Once the lead frame is seated with the alignment pins in the indexing holes, the punch tooling stroke is continued to perform the tooling operation on the device. After the punch tooling disengages the lead frame from the walking beam finger pins, the finger is reciprocated back to its initial position where the pins on the finger engage the next pair of indexing holes in the lead frame, while during the punch operation is occurring. After the punch operation is completed, the punch tooling is reciprocated away from the stationary die and the track and lead frame lift off of the alignment pins on the stationary die. The walking beam finger is then actuated to advance the next frame into the tooling stage, which advances the preceding frame into the next tooling stage. In the final step, the devices are removed, or singulated, from the frames and the frames are discarded. While the use of the walking beam has provided a significant improvement over the prior art, the overall throughput of the machines is limited by the number of times that the strip must be engaged and disengaged by the walking beam pins, which is one of the most time consuming operation during processing. Also, the necessary reciprocal motion of the actuator results in a significant amount of unnecessary machine operations that can affect the long term reliability of the machine. Additionally in the walking beam method, the punch tooling is reciprocated not only to bring the punch into contact with the device, but to align and drive the device into the die tooling. This procedure significantly increases the stroke length of the punch, thereby increasing the possibility of damaging the devices, in addition to potentially causing tooling alignment difficulties due to bending of the frames and/or track.
Some of the problems associated with the unnecessary machine motion and potential overstroke of the punching tooling are resolved with the development of the pinch roller advance machines. The pinch roller machine advances the strip in a vertically oriented position through the use of a series of pinch rollers that contact the edges of the lead frame. The only advancement operation performed by the pinch roller machine operation is the rotation of the pinch rollers to advance the strip, thereby eliminating the unnecessary reciprocal operations associated with the walking beam method. Additionally, the pinch roller machine provides for reciprocal movement of both the punch and die tooling so as to reduce or eliminate many of the problems associated with the movement of only the punch tooling in the walking beam method. However, a limitation the pinch roller method is that the rollers must still be disengaged to some extent in each tooling stage to allow the alignment of the lead frame on the alignment pins of the die tooling prior to performing the tooling operation. Unlike the walking beam method, the disengagement of the strip by the rollers and the alignment of the frame on the die are not inherently interrelated operations, and therefore, must be synchronized to operate correctly, such as through the use of computer controller. The same is true after the completion of the tooling operation and the reengagement of the strip by the pinch rollers. As is the case with the walking beam method, these operations are a critical path operation and tend to limit the throughput of the machines. In addition, the performance of the pinch rollers must be closely monitored to ensure that the rollers do not apply excessive compressive forces on the lead frame during movement of the strip that may tend to damage frame, but that sufficient force is applied to prevent the strip from slipping during rotation of the roller that will cause a misalignment condition.
The present invention is directed to continuous belt feed design which overcomes, among others, the above-discussed problems so as to allow machines that commonly use walking beam transfer arrangements to provide for increased throughput capacities by eliminating the unproductive and time consuming machine operations that are required to reciprocate the walking beam apparatus back into position prior to handling subsequent devices.
SUMMARY OF THE INVENTION
The above objects and others are accomplished by a belt feed apparatus in accordance with the present invention. The apparatus includes at least two rotatable pulleys, an endless belt capable of retaining devices to be processed is disposed around the pulleys such that rotation of the pulleys will cause said belt to travel around said pulleys, and a plurality of paired tooling members, each of said paired tooling members having first and second tooling members disposed on opposing sides of the belt and directly opposing so as to cooperate and perform a tooling operation on the leads when reciprocated toward each other along a common axis. In a preferred embodiment, two horizontally aligned pulleys with vertical axes of rotation are used to rotate the belt in a horizontal plane and the first and second tooling member are reciprocated by a common cam and the rotation of the belt and the reciprocation of the tooling members are synchronized. Alternatively, the first and second members can be driven by different cam drives that are synchronized in conjunction with the rotation of the pulleys.
Accordingly, the present invention provides significant increase in the efficiency of handling devices during sequential operations. These and other details, objects, and advantages of the invention will become apparent as the following detailed description of the present preferred embodiment thereof proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will be described in greater detail with reference to the accompanying drawings, wherein like members bear like reference numerals and wherein:
FIG. 1 is a top view of the apparatus showing three pairs of tooling members;
FIG. 2 is a front view of the apparatus along line 2 — 2 showing three pairs of tooling members;
FIG. 3 is a side view of the apparatus along line 3 — 3 showing a device in position between the tooling members with a top driven pulley and a bottom driven cam;
FIG. 4 is a side view of the apparatus comparable to FIG. 3 showing an alternative cam embodiments without the pulleys and belt; and,
FIG. 5 is a front view showing a 20-lead device in a frame attached to the device side of the belt.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The operation of the apparatus 10 will be described generally with reference to the drawings for the purpose of illustrating present preferred embodiments of the invention only and not for purposes of limiting the same. In accordance with the present invention, an endless belt 30 is disposed around the periphery of at least two horizontally aligned pulleys 20 having vertical axes of rotation. A series of directly opposed first and second tooling members, 40 and 50 , respectively are disposed on opposite sides of the belt 30 . Lead frames 98 containing electrical devices 90 having leads 92 are attached to the endless belt 30 and the pulleys 20 are rotated causing the endless belt 30 travel around the pulleys 20 until the lead frames 98 are positioned between the first and second tooling members, 40 and 50 , respectively. The first and second tooling members, 40 and 50 , respectively are then reciprocated so as to cooperate and perform a tooling operation on the device 90 . The pulleys 20 are then rotated to advance the device 90 to the subsequent pairs of tooling members. After the final shape of the device 90 is attained, the device 90 is separated from the frame 98 and the frame 98 is discarded.
In a preferred embodiment, two pulleys 20 are mounted on a horizontal bench top 12 with the rotation of the pulleys 20 occurring about the vertical axis 24 , either from below or above as shown in FIGS. 2 and 3, respectively. Two pulleys 20 are preferred to minimize the area occupied by the machine (“the footprint”) and to provide for linear movement of the devices through the tooling equipment. However, any number of pulleys 20 can be used with the present invention to achieve a desired result, for example, different sized and shaped tooling members can be accommodated by adding pulleys to change the shape of the belt. Preferably, the pulleys 20 are constructed from aluminum and the bench top 12 constructed from steel. Other materials of comparable physical characteristics can be used for the pulleys 20 and bench top 12 of the present invention. The actual dimensions and materials of construction can be varied depending upon the size of the devices to be processed.
Preferably, the pulleys 20 are provided with a series of protrusions 22 that are spaced around the perimeters of the pulleys 20 and are capable of engaging holes in the belt 30 and preventing the belt 30 from slipping when the pulleys 20 are rotated. The protrusions 22 are preferably centered and positioned in 45.degree. intervals around the circumference of the pulleys 20 and constructed of a hard tool steel grade to insure accuracy and long life; however, the design, location, and materials of construction of the protrusions can be varied by the skilled practitioner to achieve a desired result.
The endless belt 30 is preferably constructed of stainless steel or other suitable material and has a circumferential length of a size suitable to fit securely around the pulleys 20 . The belt 30 has opposing faces, a pulley face 32 that contacts the periphery of the pulleys 20 and a device face 34 that contacts the devices 90 . The belt has holes 38 through the opposing faces that are preferably centered, sized and spaced to mate with the protrusions 22 on the pulleys 20 as the belt 30 travels around the pulleys. Pins 36 are provided on the device face 34 of the belt to engage the indexing holes 96 and retain the lead frames 98 . Alternatively, the pulleys 20 can be oriented with a horizontal axis of rotation and the belt faces 32 and 34 would be horizontal. Preferably, a track 48 is provided for additional alignment and support for the bottom portion of the frame 98 when the frame 98 is attached to the belt 30 . Preferably, a high torque stepper servomotor is used to rotate the pulleys 20 and to provide precise stop and start control of the belt 30 . A pulley housing 26 can also be incorporated to protect the pulleys 20 and the belt 30 from accidental disruption during operation.
A plurality of paired first and second tooling members, 40 and 50 , respectively, are disposed on opposing sides, 32 and 34 , respectively of the belt 30 . In a preferred embodiment, each pair of tooling members are reciprocally attached to the horizontal bench top 12 in a directly opposed configuration on a monorail barrel roller assembly 58 , which is preferably provided for increased alignment accuracy and loading capability. The first and second tooling members, 40 and 50 , respectively, have opposing tooling faces 42 and 52 , respectively, which are designed to cooperate to perform a desired tooling operation on the devices 90 , when the faces are placed in close proximity by reciprocating the first tooling member 40 and the second tooling member 50 toward one another. In a preferred embodiment, the first tooling members 40 and second tooling members 50 are die and punch tooling, respectively. The actual number of paired tooling members, or stages, and the design of the tooling faces 42 and 52 , respectively, is dependent on the final design of the leads 92 as well as the shape of the leads 92 when fed into the apparatus 10 . FIGS. 1 and 2 show one possible arrangement of three paired tooling members. Additional discussion on the number of stages and the tooling is provided below by way of example.
In a preferred embodiment, each of the paired tooling members 40 and 50 , respectively, are reciprocated in opposite directions along the common rail 58 by a single cam 60 having first and second cam faces, 62 and 64 , respectively. The cams 60 for each tooling stage are driven by a common camshaft 68 , which provides for synchronization of the devices 90 in each tooling stage. A trough 66 is provided in each of the cam faces, 62 and 64 , respectively, for conversion of the rotational motion of the cam 60 into reciprocal motion of the tooling members, 40 and 50 , respectively. A lever arm 70 connects the cam 60 and the tooling members 40 and 50 , respectively. The lever arm 70 has a cam end 72 that rides in the trough 66 of the cam 60 . The lever arm 70 is mounted on the bench top 12 using a sturdy bearing assembly 71 that creates an axis about which the arm could pivot such that when the cam end 72 moves within the trough 66 the lever arm 70 and the tooling members, 40 and 50 , respectively, reciprocate a fixed distance relative to the amount of the displacement of the cam end 72 . Substantially simultaneous reciprocation of the tooling members 40 and 50 is achieved through the use of complimentary troughs 66 in the first and second cam faces, 62 and 64 . The attachment of a first lever arm 70 between the first cam face 62 and the first tooling member 40 and the attachment of a second lever arm 70 between the second cam face 64 and the second tooling member 50 allow the motion of the tooling members, 40 and 50 , to be commonly controlled. Preferably, the tooling members, 40 and 50 , are spaced equidistant from the location of the devices 90 and the troughs 66 are complimentary so as to provide for minimal translation of the tooling members, 40 and 50 . However, it will be appreciated that the relative translation of each tooling member, 40 and 50 , respectively, and the timing of the movements can be varied by changing the design of the trough 66 in each of the cam faces 62 and 64 , respectively. Also, the cams 60 and the cam shaft 68 are preferably positioned below the horizontal bench top 12 in a cam housing 14 and the lever arms 70 pass through the bench top 12 in order to provide a more compact arrangement of the components. Alternatively, the cams 60 and camshaft 68 can be mounted on the bench top 12 in a linear arrangement. Preferably, a three phase servomotor with a gear reducer and a clutch/brake device is used to provide precise start and stop control over the turning of the cam shaft 68 ; however, other methods of precisely controlling the turning of the cam shaft 68 may be used in the present invention.
In an alternative cam embodiment, as shown in FIG. 4, the first tooling member 40 and the second tooling member 50 are driven by separate camshafts, 68 and 69 , respectively. The relative movement of the first and second tooling members, 40 and 50 , respectively, can be synchronized by the use of a common servomotor in conjunction with 90-degree gears connecting camshaft 68 with camshaft 69 or through the use of separate servomotors that are synchronized in some manner, such as with a computer.
Also in a preferred embodiment, a computer is used to provide synchronized control over both the pulley servomotor and the cam servomotors. In addition, alignment sensors can be positioned on the respective tooling members, 40 and 50 , to be used in conjunction with the holes 38 in the belt 30 and tied into the computer to ensure the proper alignment of the device 90 in the tooling stage prior to movement of the tooling members, 40 and 50 , respectively. The anticipated speed of processing devices 90 is approximately 3 to 4 strokes/second as compared to a speed of approximately 1 stroke/second using the prior art methods.
An example of the use of the apparatus of the present invention will be described with respect to the trimming and forming of a 20-lead device as shown in FIG. 5 . In a preferred embodiment for processing the 20-lead device to have J-shaped leads, the pulleys 20 are preferably 5.5 inches in diameter having an axial length of 1.0 inch and constructed from aluminum and spaced apart with approximately 15.0 inches between the axes of rotation. The belt 30 is constructed of {fraction (3/4 )} inch wide by 10 mil thick stainless steel. Seven paired tooling members are positioned on opposing sides of the belt 30 and spaced in ¾ inch intervals to perform the tooling operations on the devices. Lead frames 98 containing the devices 90 are fed to the apparatus be conventional methods and are attached to the pins 36 on the belt 30 through the ovular shaped indexing holes 96 in the top portion of the lead frames 98 . The bottom portion of the lead frame 98 is engaged in the track 48 . The pulleys 20 are rotated to cause the belt 30 to travel bringing the lead frame 98 to the first tooling stage in which the die and punch tooling has been designed to remove the flashing from between the leads 92 . The die and punch tooling is reciprocated toward the device and the alignment pins on the die tooling engage the circular indexing holes 95 in the bottom portion of the lead frame 98 . The precise alignment of the lead frame 98 in the die is accommodated without disengaging the lead frame 98 by incremental slide of the ovular shaped indexing holes 96 on the pins 36 . The pulleys 20 are again rotated to move the belt 30 and the lead frame 98 to a second tooling stage where the dambars 97 which are used to provide additional structural support to the lead frame 98 and to prevent the flow of molding compound onto other devices are punched out of the lead frame 98 . The lead frame 98 is then advanced to the next tooling stage where the leads 92 are trimmed to the proper length. The lead frames 98 are then advanced through a series of four forming operations in which the free end of the leads are first bent approximately 90-degree with respect to the end of the lead attached to the device 90 toward the bottom side of the device 90 . The leads 92 are then bent near the attached end approximately 90-degree toward the bottom side of the device 90 after which the free end of the leads 92 are again bent so that the free end faces the bottom surface of the device 90 . Finally, the leads 92 is bent toward the bottom surface of the device 90 until the free end of the device 90 is in a close proximate relation with the bottom surface of the device 90 . After this final forming step, the device is singulated from the lead frame 98 by punching the device 90 out of the lead frame 98 . The lead frame 98 can then be discarded.
Those of ordinary skill in the art will appreciate that the present invention provides tremendous advantages over the current state of the art for efficient handling of material through staged processing. In particular, the present invention provides for a continuous feed of lead frames containing electrical devices to a trim and form machine. Also, the present invention allows for short stroke lengths of the punch and die tooling. Thus, the present invention provides a effective method of increasing the capacity of machines used to perform material handling applications. While the subject invention provides these and other advantages over the prior art, it will be understood, however, that various changes in the details, materials and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.
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A method of processing a leadframe strip defining a first row of alignment holes and a second row of alignment holes. One embodiment of the method comprises allowing incremental advancement of said leadframe strip using said first row of alignment holes and refraining from using said second row of alignment holes to allow said advancement.
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FIELD OF THE INVENTION
This invention relates to a method for testing precorneal tear film stability. It relates to a process to aid in the diagnosis of diseases of the eye surface and of the lacrimal system. More specifically, it tests dry and wet eye conditions. Precorneal tear film stability is also useful for predicting candidates who might be successful contact lens wearers.
BACKGROUND OF THE INVENTION
A stable preocular tear film is essential for maintenance of a healthy and comfortable ocular surface as well as for good vision. An unstable preocular tear film results from inadequate or excessive tear production and from inadequate blink force improperly mixing the tear constituents. The ability to quantitatively measure tear film inadequacy is important to the diagnosis and management of dry and wet eye conditions.
DESCRIPTION OF THE PRIOR ART
There are a number of tests which describe methods of measuring preocular tear film stability. None of the tests are definitive in a differential diagnosis of dry and wet eye conditions. They only lend supportive evidence for diagnosing these conditions.
Schirmer tear test is a tear production test using a strip of wettable filter paper inserted into the lower conjunctival fornix. An assessment of tear production is made based on the length of wetness of the strip over a five minute time. This test is invasive, potentially dangerous to the corneal surface, inaccurate due to inter and intra subject variation of tear flow and the results are controversial among eye car practitioners.
Break up time (BUT) test is a tear integrity test. The time interval between the blink and the first observable dry spot of the corneal surface is related to tear integrity. The test requires sodium fluorescein which disrupts the tears and leads to inaccurate results. The test is limited by the skill, experience and subjectivity of the observer. It requires the use of expensive equipment, namely a biomicroscope which projects a bright light which may cause reflex tearing. It also tests during an abnormal state since the eyes must remain open beyond the normal blink rate.
Tear thinning time (TTT) test is a test of tear integrity. The time interval between the blink and the first observable distortion of the reflected mire from a keratometer is related to tear integrity. This test requires the use of expensive equipment, a keratometer, and is limited by observer experience. The test is also limited in that it tests a very small area of the preocular tear surface. It tests during an abnormal state since the eye must remain open beyond the normal blink rate.
Tear meniscus Height (TMH) is a tear production test. It assesses the amount of tear by the height of tear meniscus between the eye surface and the lower lid. It requires expensive equipment, namely a biomicroscope with a bright light which could stimulate reflex tears. Additional tears would cause inaccurate results. It is also limited by the experience and subjectivity of the observer.
Lipid layer thickness test is a specific test about the external lipid layer of the tear film. Deficiencies of this layer could enhance tear evaporation and thus create a risk for dry eye condition. The test is not specific nor dry eye but indicates dry eye conditions indirectly when the lipid layer is not seen. The test is limited by the experience of the observer. It also requires expensive equipment, namely a biomicroscope.
Dye tests such as Rose Bengal and Sodium Fluorescein will detect tissue destruction. When the tissue shows destruction, one can conclude a potential loss of mucin, the inner layer of the tear film. Since mucin is responsible for the maintenance of the tear film over the eye surface, dry eye symptoms may be present. This test does not provide quantitative or qualitative tear film measurements. It requires the expensive biomicroscope and an experienced observer.
Punctum plug test obstructs the drainage of tear from the eye surface. Therefore, if one has dry eye symptoms from insufficient tear production, more tears should remain on the eye surface when drainage is obstructed. That in turn should result in some amelioration of the dry eye symptoms. This test does not provide qualitative measurements, just indirect quantitative tear production via patient symptoms or signs of improvement several days into the test. The test is limited by the skill and experience of the practitioner. It is invasive and expensive requiring considerable practitioner skill, time and expensive equipment, namely the biomicroscope.
Lactoplate test assesses the lacrimal gland function by the amount of lactoferrin it produces in the tear film. The test uses a filter paper which is placed on the eye to absorb the tear with the lactoferrin. The amount of lactoferrin is assessed using an immunodiffusion technique. The test is invasive and is limited by the experience of the examiner. It is expensive and requires two or three days to determine if the lacrimal gland is functioning normally. This test uses indirect assessment of the aqueous tear layer and is not conclusive for all dry eye conditions.
Agar diffusion lysozyme test differs from the lactoplate test only by the product which the lacrimal gland secretes. It possesses the same benefits and disadvantages.
Conjunctival scraping and impression cytology assesses the goblet cell density which determines the amount of mucin secretion. It is invasive and is neither quantitative nor qualitative toward tear film stability. It requires an experienced practitioner and expensive equipment.
DESCRIPTION OF THE INVENTION
The invention, Lavaux tear test, Lacrimal Equilibration Time Test (LET), assesses preocular tear film stability. Visual acuity is measured with standard tests such as: a snellen chart, Landolt C or tumbling E chart, or other such character type charts or contrast sensitivity tests. This measurement, then becomes the normal or standard visual acuity one relates to during the test. An ophthalmic preparation, such as carboxymethylcellulose, the principal ingredient of Celluvisc® ophthalmic solution manufactured by Allergan Pharmaceutical, is then added to the preocular tear film.
Due to the viscosity of this preparation, visual acuity becomes blurred. The subject resumes normal blinking and eye movements during the test. If the subject is capable of normal tear film stability, adequate tear production, adequate blink force and sufficient drainage, the preparation will be eliminated via the lacrimal drainage system from the preocular surface within a reasonable time. The time required for visual acuity to return to normal becomes the Lacrimal Equilibration Time (LET). The LET time is then used to diagnose normal and abnormal tear film stability. Using one drop of carboxymethylcellulose per eye, normal LET is considered to be 5 minutes or less. LET times longer than 5 minutes detects subjects with unstable tear film. This includes subjects with inadequate aqueous tear production, inadequate blink force and/or inadequate tear drainage. Thus the Lavaux tear test detects both qualitatively and quantitatively dry and wet eye subjects.
The Lavaux Tear Test, Lacrimal Equilibration Time (LET) is easily administered. With minor training or simple written instructions, ancillary personnel and lay people can administer the test in a practitioner's office or off-site in a variety of facilities. The test is performed under normal eye conditions and is non-invasive and safe, since the ophthalmic preparation is soothing and comfortable to the eye. The ophthalmic preparation is readily available and quite inexpensive. The LET is quick, since the results are observable within five minutes.
EXAMPLE 1
This example sets forth a generalized procedure for this dry eye test and results.
Twenty patients were selected from my practice without regard to age or sex. Their average age was 52 and ranged from 17 to 77 years of age. There were 7 males and 13 females. None of the patients were currently wearing contact lenses or presenting microbial infection. An attempt was made to include 12 symptomatic patients as well as 8 asymptomatic patients. Subjects were selected over a two month period from patients seeking routine care as well as from patients who had been previously diagnosed as symptomatic dry eye patients. I either performed or directly supervised the performance of all subject testing.
For each patient the best snellen visual acuity of both eyes was measured at 20 feet. Patients used their glasses if needed for better VA. This acuity was used as the base-line standard and patients were instructed to relate to this standard throughout the test. Patients were asked to assume an upward gaze, the lower lid was gently depressed and one drop of Celluvisc® was instilled into the lower conjunctival sac of the right followed by the left eyes. Care was practiced to minimize expression of lower lid meibomian and accessary gland secretions as well to avoid creating patient anxiety. A stop watch was switched on when the Celluvisc® was instilled and was switched off when the subjects base-line VA was regained and sustained after normal blinks. This time interval became the Lacrimal Equilibration Time (LET). Subjects were instructed not to force blinking or wipe their eyes in an effort to hasten the removal of the drop for early resumption of base-line VA. Patients remained in the examination chair without restriction of eye movements. During the test time, patients were questioned about possible dry and wet eye symptoms or engaged in "small talk" to distract them from focusing on visual clarity. After at least 20 minutes, each patient received a Schirmer I test under anesthesia by a single drop of 0.5% proparacain OU.
RESULTS AND DISCUSSION
Data representing age, sex, LET times, Schirmer times and presence of dry eye symptoms for all 20 patients are presented in Table 1. The findings of the Schirmer tear test showed less tear production with advancing age. The findings of the LET test also showed longer times with advancing age. Both lower Schirmer test and longer LET times showed a direct correlation with aging and thus with each other. The LET test identified symptomatic patients as those patients requiring over 5 minutes to complete the test. Completion of the test was defined as reaching base-line VA. Asymptomatic patients completed the test in less than 5 minutes.
The LET test involves the entire lacrimal system, tear production, tear mixing by blinking and tear elimination. A drop of Celluvisc® to the tear disturbs both the normal visual acuity and tear volume. High LET results may be due to one of three reasons: (1) A poor flushing mechanism of the aqueous layer may exist. (2) High LET times may be a result of poor tear elimination of the tears via the lacrimal drainage system and (3) High Let times may be a result of inadequate blink force.
CONCLUSIONS
The LET offers an alternative to currently available dry eye tests. It correlates highly with dry eye symptoms. It offers significant advantages to the practitioner since it uses readily available materials, as easily administered by clinicians and their ancillary personnel and can be performed off-site by persons with minimal training. In this study the LET test results were at least as reliable as the more invasive Schirmer test in assessing tear production. It demonstrated superior results over the Schirmer test in detecting symptomatic patients. It may also be useful for detecting inadequate tear elimination via the lacrimal drainage system and inadequate blink force.
The LET test may prove to be the easiest, least invasive, quickest, most reliable and most cost effective dry eye test currently available to the eye care practitioner.
TABLE 1______________________________________Collected data of twenty Patient tests.Age Sex OD-Schirmer-OS OD--LET--OS Symptoms______________________________________17 F 17.00 16.00 1.75 1.75 026 F 15.00 13.00 1.50 1.25 027 F 7.50 10.00 10.00 11.50 Y31 F 13.00 13.00 3.50 3.75 032 M 17.00 17.00 3.25 3.25 035 F 5.50 10.00 1.00 1.50 038 F 8.00 11.00 10.50 9.00 Y40 F 13.00 14.00 1.50 0.67 044 F 3.50 3.50 10.00 8.50 Y46 F 2.00 9.00 12.00 12.00 Y49 F 20.00 19.00 5.00 3.00 064 M 5.00 8.00 15.00 15.00 Y70 M 3.50 7.00 14.00 11.00 Y71 F 14.00 13.00 13.00 15.00 Y71 M 15.00 15.00 6.00 6.00 Y73 M 6.00 15.00 5.50 5.50 Y74 F 5.50 0.00 4.50 4.00 075 M 13.00 13.00 15.00 15.00 Y76 F 2.50 0.00 15.00 5.75 Y77 M 5.50 6.00 10.00 10.00 YAVERAGE51.80 9.58 10.63 7.90 7.17STANDARD DEVIATION5.50 5.16 4.94 4.76______________________________________
The test results shown herein, as well as other data collection still in progress, show the benefits of this invention for the identification of persons possessing inadequate precorneal tear film stability. The above example is not intended to be all inclusive or to limit in any way the application of the invention or the scope of the appended claims.
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A method for measuring precorneal tear film stability and diagnosing dry and wet eye conditions. The method comprises stressing baseline visual acuity with the installation of a predetermined ophthalmic preparation and measuring the time to recover normal visual acuity. Once baseline visual acuity is regained and sustained, the Lacrimal Equilibration Time (LET) is recorded. LET measures the quality of precorneal tear film stability and is related to the degree of dry and wet eye condition.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for calibrating extruded lines from hollow chamber sheets formed of thermoplastic resin. The present invention also relates to hollow chamber sheets that have been manufactured on an extruder with the inventive calibration device.
2. Discussion of the Background
DE-C 32 44 953 and EP-B 158 951 describe vacuum mold channels which are used to calibrate hollow chamber profiles out of thermoplastic resin. These documents disclose that single piece extruded hollow chamber profiles are guided through a channel of two cooling plates that are equipped with vacuum channels. Sinking of the hollow chamber profile due to gravitational forces during the cooling phase is counteracted by a supporting force resulting from the difference in pressure between the interior and exterior of the hollow chamber profile.
DE 3 526 752 describes a procedure and an apparatus for the production of hollow chamber sheets out of resin. In this procedure, the upper and lower flanges are extruded and then bonded with prefabricated fins. The upper and lower flanges are taken in and cooled with the help of vacuum calibrators. This procedure offers the benefit of being able to achieve any fin design and combine various resins on the hollow chamber profiles.
DE-U 9 014 958 describes a procedure and an apparatus for the extrusion of hollow chamber sheets out of thermoplastic resin. In this procedure, the flanges and the fins of the profile are extruded separately and then welded to each other while they are still in their thermoplastic condition. This is done to prevent sink marks that can occur due to thermal contraction of the fins during the cooling phase, particularly in the case of single piece extrusion. The hollow chamber sheet profile obtained this way is immediately guided through a calibration device with an upper and a lower endless belt which preferably consists of metal. The cooling plates, which are located above or below the endless belts and through which coolant flows, serve to release heat. In order to maintain good contact between the endless belts and the cooling plates and to guide the endless belts at an established and even distance, the cooling plates can be equipped with vacuum channels via which the endless belts are taken in. This calibration method has the disadvantage that the hollow chamber profile is not supported by vacuum forces against gravity related sinking so that the method cannot be used on single piece extruded hollow chamber profiles.
Common vacuum calibration devices, where frictional forces occur between the extruded surface and the cooled metal plates of the calibration device (which also have vacuum openings), have a variety of disadvantages. Particularly on scratch-sensitive resins, the gliding of the extruding surface during calibration may cause the extruded surface to become scratched. Scratching of the extruded surface may lead to other problems if the abrasions accumulate.
The change between sticking and gliding (“stick-slip”) between the extrudate (i.e., the extruded surface) and the calibration device leads to an uneven draw of the extrudate. As a consequence of the uneven draw, fluctuations in the thickness of the extrudate in the extrusion direction may occur. These fluctuations may cause noticeable waviness on the hollow chamber profile. This waviness impairs the transparency of fin plates formed out of the transparent resin.
Cooling related to shrinkage of the fins when the fin plate runs through the calibration process (and also due to the pressure of the upper and lower flanges on the calibration surface) can lead to the formation of sink marks in the area of the fins. The sink marks become more distinct when the temperature difference of the fins between entering and exiting calibration increases. The sink marks also become more distinct if the negative pressure becomes lower and if the fins become thicker.
High negative pressure, which is desired for good thermal transmission between calibration and the strap surface and for avoiding sink marks, leads to high draw forces due to the frictional forces between the calibration device and the extrudate. In extreme cases, high draw forces can cause the extrudate to rupture between the calibration device and the drawing equipment.
The drawing rollers can also slip on the extrudate surface. This slipping may cause the extrusion process to collapse. In order to avoid such slipping, even at high negative pressure, complex multi-roller designs are required.
Too large a temperature difference can lead to the formation of internal stresses in the extrudate. Thus, the drawing speed that can be achieved with dry vacuum calibration is limited by the maximum allowable temperature difference between the temperature of the extrudate when exiting the extrusion die and temperature of the extrudate when exiting the calibration device. An extension of the calibration device as an alternative to increase the drawing speed is also problematic due to rising draw forces.
SUMMARY OF THE INVENTION
Accordingly, one object of the invention is to provide a novel and improved apparatus and method for the calibration of hollow chamber sheet extruded lines formed of thermoplastic resin.
Another object of the invention is to provide an apparatus and method for calibrating extruded lines in which frictional forces on the extruded line are minimized.
These and other objects are achieved according to the present invention by providing an apparatus for the calibration of hollow chamber sheet extruded lines. The apparatus includes a vacuum housing and a planar intake area at a first end of said vacuum housing. The planar intake area is configured to receive the extruded line. Support rollers within said vacuum housing are configured to support said extruded line. Said extruded line exits said vacuum housing through a planar outlet area located at a second end of said vacuum housing opposite said first end.
BRIEF DESCRIPTION OF THE DRAWINGS
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:
FIG. 1 is an illustration of an inventive apparatus for calibrating hollow chamber sheet extrudate; and
FIG. 2 is a flowchart describing the inventive process for calibrating hollow chamber sheet extrudate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1 thereof, a calibrating device 100 is located a short distance behind an extrusion die that is fed by an extruder. The calibrating device includes a vacuum housing 1 which has a planar intake area 2 , support rollers 3 , and a planar outlet area 4 . The intake area 2 , the support rollers 3 , and the outlet area 4 form a channel through which the extruded hollow chamber sheet extruded line is pulled, supported, and cooled. A drawing device, such as a pair of drawing rollers 8 , creates a tensile force in the extruded line. It is also possible, however, to equip the support rollers 3 with a drive, with both a drive and the structure described above, and/or with any suitable device for drawing the extruded line.
The planar intake area 2 serves the purpose of cooling the outer surfaces of the extruded line to below its distortion temperature. An extruded line formed out of polymethylmethacrylate resin, for example, exits the extrusion die at a temperature of 260° C. (500° F.) but is cooled to about 110° C. (230° F.) by the planar intake area 2 . Further, the planar intake area 2 serves the purpose of sealing the housing 1 from the environment so that a negative pressure can be maintained in the housing 1 .
At least in the upper area, it must be possible to evacuate the housing 1 to avoid a sinking of the hollow chamber sheet profile (e.g., a fin double plate) due to the weight of the upper flange and the fins. For this purpose, a relatively low negative pressure of 10 to 100 Pa, for example, is sufficient. Also, the lower half facing the extrudate bottom is evacuated to safely avoid the formation of sink marks due to cooling related contraction of the fins.
The support rollers 3 are arranged above and beneath the channel for the extruded line. They support the extruded hollow chamber sheet line against the negative pressure on the housing. Advantageously, the support rollers 3 can be adjusted in height relative to the vacuum housing 1 . This offers the benefit of being able to adjust the support for the extrudate surface in exact accordance with the shrinkage of the fins throughout the progressive cooling process.
Cooling of the extrudate surface occurs through a cooling of the support rollers 3 , through spray cooling of the extrudate surface, or by flooding the entire housing 1 with water (wet calibration). Under certain circumstances, cooling of the housing 1 and thermal transfer through radiation and convection may be sufficient.
The planar outlet area 4 , similar to the planar intake area 2 , serves to seal the calibration device. The height of the planar outlet area 4 can be adjusted relative to the vacuum housing 1 , if necessary, or equipped with flexible sealant strips 7 . The flexible sealant strips 7 are formed of any temperature-resistant resin with good gliding properties such as polytetrafluoroethylene (PTFE), for example.
Referring now to FIG. 2, a flowchart describing the inventive method is shown. In step 200 , a hollow chamber sheet extruded line 5 formed of thermoplastic resin is pushed out of an extrusion die 6 . In step 202 , the extruded line 5 is pulled through the planar intake area 2 . In step 204 , the extruded line is supported by and pulled between the support rollers 3 . In step 206 the extruded line 5 is pulled through the planar outlet area 4 with flexible gaskets 7 . A drawing device such as the drawing rollers 8 may be used to pull the extruded line 5 through the vacuum housing 1 of the calibration device.
On an extruder that is equipped with a calibration device in accordance with the invention, high-quality hollow chamber sheets formed out of thermoplastic resin can be produced.
The calibration fixture according to the invention is basically suited for hollow chamber sheets and resins of all types. Particular benefits result from multiple fin plates and double fin plates formed out of polymethylmethacrylate, polycarbonate, or other transparent resins. In this manner, better transparency of the hollow chamber profiles is achieved since scratching of the profile surface is avoided. Additionally, wavy thickness fluctuations on the flange are largely avoided. Such fluctuations lead to an undesirable deflection of penetrating rays of light due to lens flare. Also, the calibration device can be adjusted randomly in its measurements to fit all extruders or all hollow chamber sheet extrusion dies.
Due to the low frictional forces in the calibration device, the necessary draw forces are also comparatively small. This makes it possible to produce fin plates with few or very thin fins, which resist only low draw forces. By avoiding gliding processing techniques, damage to the extrudate surface is prevented. Further, the disadvantageous changes between sticking and gliding (“stick-slip”) of common vacuum calibration fixtures does not occur. Moreover, the hollow chamber sheets that are produced are nearly free of waviness and sink marks in the area of the fins. Due to overall low frictional forces in the calibration device, it is possible to achieve equipment layouts that are considerably longer than those conventionally utilized.
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.
The present application is based on German Patent Application 198 04 235.3, filed Feb. 4, 1998. German Patent Application 198 04 235.3 and all reference cited therein are hereby incorporated by reference in their entirety.
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An apparatus for calibrating hollow chamber sheet extruded lines out of thermoplastic resin includes a vacuum housing and a planar intake area at a first end of the vacuum housing. The planar intake area is configured to receive the extruded line. Support rollers within the vacuum housing are configured to support the extruded line. The extruded line exits the vacuum housing through a planar outlet area located at a second end of the vacuum housing opposite the first end.
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BACKGROUND OF THE INVENTION
Commercially useful copper base alloys which possess a combination of high strength and high electrical conductivity are usually difficult to obtain because the methods and elements utilized to provide good strength properties, for example, usually do so at the detriment of the electrical conductivity of the alloys. From a number of approaches to the solution of this problem, two methods of achieving the combination of high strength and high electrical conductivity have been most readily utilized. The first method is determining and adjusting the elements to be alloyed with the base copper to provide inherent high strength and electrical conductivity properties in the resulting alloy system. Elements such as zirconium and chromium have been used in the past as additions to copper base alloys to provide the desirable strength-conductivity combination. Precipitation hardened alloys which contain chromium generally have lower electrical conductivity but higher strength than pure copper. The precipitation of zirconium in copper is known to give large increases in electrical conductivity to the base copper but only small increases in strength properties over the values for the solid solution of zirconium in copper.
Another method which has been utilized to provide the strength-conductivity combination in copper base alloys includes adjusting the homogenization, hot working, annealing and aging of the alloy to provide high strength properties to the alloy system without reducing the electrical conductivity of the system. An example of this approach may be found in U.S. Pat. No. 3,930,894, issued Jan. 6, 1976. This patent teaches a method of working phosphor-bronze copper alloys which includes a high temperature homogenization, hot and cold working, intermediate annealing and a final heat treatment to provide desired properties. The alloy system utilized in said patent may include chromium. This patent does not discuss treating precipitation hardenable copper base alloys which contain chromium as an alloying element.
The present invention is an attempt to overcome the shortcomings of the alloying element methods and processing method described above by treating chromium-containing precipitation hardenable copper base alloys so that not only the strength properties of said alloys are increased after treatment but the electrical conductivity properties are also increased.
Accordingly, it is a principal object of the present invention to provide a method of processing chromium-containing precipitation hardenable copper base alloys in such a manner so as to increase both the strength and electrical conductivity properties of the alloys.
Further objects and advantages of the present invention will become apparent from a consideration of the following specification.
SUMMARY OF THE INVENTION
In accordance with the present invention it has been found that the foregoing object may be readily achieved by processing a precipitation hardenable chromium-containing copper base alloy according to the following steps:
a. casting a precipitation hardenable copper base alloy which contains chromium;
b 1 . hot working the alloy at a starting temperature of 850°-950° C; or
b 2 . hot working the alloy at a starting temperature of 950°-1000° C to effect the maximum solid solution of all alloying elements;
c. if step (b 1 ) has been utilized, solution annealing the worked alloy at a solutionizing temperature of 950°-1000° C, preferably 975°-1000° C, for a period of time sufficient to insure the maximum solid solution of all alloying elements;
d. rapidly cooling said alloy to maintain said maximum solid solution to all alloying elements;
e. cold working the alloy to a total reduction of at least 60% and preferably to at least 75%;
f. aging said alloy at 400°-500° C for one to 24 hours and preferably 430°-470° C for 2 to 10 hours;
g. cold working the alloy to a total reduction of at least 50% and preferably to at least 75%;
h. aging said alloy at 150°-250° C for one to 24 hours and preferably 175°-225° C for 2 to 10 hours; and
i. optionally cold working said alloy to the final desired temper.
DETAILED DESCRIPTION
The present invention provides an improvement in the combination of strength and electrical conductivity properties of the alloy system being processed through the steps of solution annealing to bring all alloying elements into maximum solid solution, cold working the alloy to such a degree so as to strain harden the alloy to high strength and finally subjecting the alloy to an aging/cold working combination of steps.
The alloy system which may be processed effectively according to the present invention must be precipitation hardenable and should contain at least a small percentage of chromium. Additional alloying elements may be added to the copper-chromium system, among which are zirconium, vanadium and niobium. Other elements may also be added to achieve particularly desirable strength and/or conductivity properties.
The hot working step of the processing of the present invention may by itself be used to provide the effect of solution annealing. This is generally accomplished by performing the hot working at a temperature which is high enough to place all of the alloying elements into maximum solid solution. This temperature should be at least 950° C with a preferred temperature range of 975°-1000° C to insure said maximum solid solution.
The alloys utilized in said process are generally cast at a temperature which ranges between 25° C above the melting point of the alloy up to approximately 1300° C. This casting may be performed by any known and convenient method.
The hot working reduction requirement is generally what is most convenient for further working. The process utilized in the present invention has no particular dimensional requirements other than that the hot working be accomplished according to good mill practice. If the hot working step is also utilized to provide the solution annealing of the alloy, the main consideration is that the hot working be performed to effect the maximum solid solution of all the alloying elements. This permits the later precipitation during aging of the most desirable high volume fraction of fine uniform dispersions of intermediate solid phases consisting of chromium, zirconium and niobium, the phases existing in the alloy matrix either as dependent or intermixed phases. The solution annealing step of the process utilized in the present invention, whether performed as part of the hot working step or as a separate step after hot working, also provides for the maximum solid solution of all the alloying elements. This solution annealing is accomplished at a temperature between 950° and 1000° C. It is preferred that the solution annealing be accomplished at a temperature between 975° and 1000° C. It should be noted that this solution annealing step can take place at any point in the instant process after the initial hot working step, provided that rapid cooling, cold working and aging steps are performed after the solution annealing step.
The alloy, after being either hot worked alone or hot worked in combination with a separate solution annealing step, is then rapidly cooled so as to maintain the maximum solid solution of all alloying elements. Cooling to 350° C or less is necessary to maintain said maximum solid solution. This cooling may be accomplished according to procedures well known in this art, using either air or a liquid as the cooling medium.
The next step in the process utilized in the present invention is cold working of the alloy. This cold working step is utilized to provide an increase in strength to the alloy as well as being used to meet dimensional requirements. The alloy is generally cold worked to an initial reduction of at least 60% and preferably at least 75%. This relatively high cold reduction serves to impart more strain hardening to the alloy prior to aging as well as impart improvement in the electrical conductivity of the aged alloy. The improvement in electrical conductivity after aging of the alloy is presumably brought about by altering the kinetics of precipitation in the alloy matrix. This cold working step may be the final cold working before aging of the alloy if the alloy is reduced to the final desired dimensions. The cold working may be utilized in cycles with the aging so that a cycle may end with either an aging step or a cold working step.
The cold working of the alloy is followed by an aging step. This aging is generally performed at a temperature between 400°-500° C for one to 24 hours, preferably between 430°-470° C for 2 to 10 hours. This aging is performed to increase the mechanical and electrical conductivity properties of the alloy. After this aging step, the alloy is further cold worked to a total reduction of at least 50% and preferably 75%. The alloy is then aged at a temperature between 150°-250° C for one to 24 hours, preferably between 175°-225° for 2 to 10 hours. This final aging is performed to restore the electrical conductivity values to the highly cold worked alloy and thus provide the desirable combination of high electrical conductivity and high strength in the alloy.
The process of the present invention also contemplates the steps of fabricating a final desired article out of the worked alloy material and then subjecting said fabricated article to the low temperature thermal treatment of the present invention. In other words, the final cold working step before the final low temperature thermal treatment step of the present invention will become a fabricating cold working step.
The process of the present invention and the advantages obtained thereby may be more readily understood from a consideration of the following illustrative example.
EXAMPLE
An alloy having a composition of 0.60% by weight chromium, 0.16% by weight zirconium, 0.18% by weight niobium, balance essentially copper was vacuum melted and cast under an argon protective atmosphere. After hot working the alloy, it was solution annealed at 1000° C for 45 minutes to place all alloying elements into maximum solid solution. The alloy was then cooled and subjected to cold working with a 75% reduction. The alloy was subjected to heat treatment of 450° C for 4 hours and was then cold worked to an additional 75% reduction. Properties of the alloy were measured at this point in the processing and again after an additional heat treatment at 200° C for 8 hours. Both the strength and electrical conductivity properties of the alloy increased after the additional low temperature heat treatment. These results are shown in Table I. For a comparison, this processing was compared to another processing system from the literature. This other system contained an alloy composed of copper with 0.40% by weight chromium, 0.15 % by weight zirconium, 0.05% by weight magnesium, balance essentially copper. This alloy was subjected to the processing shown in Table I and measurements of its properties were taken both after cold reduction and after an additional heat treatment.
TABLE I______________________________________ELECTRICAL CONDUCTIVITY ANDSTRENGTH COMPARISON PROPERTIES UTS 0.2% YSProcessing (ksi) (ksi) % IACS______________________________________S.A. + 75% CR + 450° C/4 hrs. + 92 88 7175% CR (A)(A) + 200° C/8 hrs. 98 93 74Literature Processing.sup.(1)S.A. + 60% RA + 450° C/1/2 hr. + 100 97 6590% RA (A)(A) + 450° C/1/2 hr. 95 90 80______________________________________ .sup.(1) P. W. Taubenblatt et al., Metals Engineering Quarterly, November 1972, Volume 12, p. 41.
Table I illustrates the improvement in both strength and electrical conductivity obtained by the final low temperature thermal treatment in the process of the present invention. This improvement in both strength and conductivity properties is to be contrasted with the properties obtained from the high temperature thermal treatment from the literature processing, where the strength properties were diminished with treatment and only the electrical conductivity was improved. The process of the present invention therefore presents an opportunity to improve both the strength and electrical conductivity properties of an alloy without detrimentally affecting either one of the properties.
This invention may be embodied in other forms or carried out in other ways without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered as in all respects illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all changes which come within the meaning and range of equivalency are intended to be embraced therein.
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A process of heat treating and mechanically working chromium-containing precipitation hardenable copper base alloys is disclosed. The combination of hot and cold working, annealing and novel low temperature thermal treatment steps increases both the strength and electrical conductivity properties of the alloys without excessive cold working.
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BACKGROUND OF THE INVENTION
Bit and/or stabilizer balling is regarded as a prime technical problem area in oil and gas well drilling. Balling is prevalently defined as the stuck formation material consisting of the drilled materials, also called `drilled cuttings`, or debris that is stuck tight to the surface of the bit and/or stabilizers that are otherwise hard to be removed by the hydraulic circulation of the drilling fluid present. Balling results in detrimental effects to the drilling operations in the form of decreased rate-of-penetration (ROP), frequent trips in and out of the hole causing increased cost of the drilling operation, surge and swab pressure increases, reduced weight-on-bit (WOB) and bore-hole instability.
The causes of bit-balling have been documented in the literature as being manifold. Causes vary from the type of formation that is being drilled, the design characteristics of the drill-bit, the applied down-hole hydraulics, itself consisting of the flow-rate, bit-hydraulic-horsepower (BHHP), formation confining and/or differential pressure, physical and chemical properties of the drilling fluid. However, studying the problem of bit/stabilizer balling in the field can be extremely time consuming as well as expensive. Further, it becomes a great problem to isolate and study the effects of each affecting parameters independently. Hence what is needed in the art is a new technique to study the problem of bit/stabilizer balling, the test procedure of which is quick and the methodology of which is simple yet robust, such that the desired operating conditions can be simulated quickly, providing accurate and repeatable results.
DESCRIPTION OF THE PRIOR ART
The prior art in the study of bit/stabilizer balling has consisted mainly of full-scale laboratory experimentation and field scale drilling studies. A few drilling studies utilizing micro-bits have also been conducted.
Cheatham and Nahm (1990) conducted some of the earliest full-scale drilling experiments in the laboratory to study bit-balling. Pierre shale core samples measuring 15 inches in diameter and 3 feet in length were used under separate differential and confining pressure conditions. The influence of confining pressure on bit-balling was studied as also the effect of balling on the torque while the drilling operation was in progress. Although the study provided an insight into the mechanism of balling and documented the influence of the confining pressure on balling tendency, no attempt was made to quantify the degree of balling. Further, the study was mainly focussed on roller-cone bits and on PDC (Polycrystalline Diamond Bits) in which the balling phenomena tends to be a more serious problem.
Ledgerwood and Salisbusry, "Bit-balling and Wellbore Stability of Downhole Shales", SPE22578, (October 1991), studied the bit-balling problem in shale through micro-bit drilling experiments under atmospheric as well as pressurized conditions. The micro-bit consisted of a couple of PDC cutters attached to a shaft oriented in a fish-tail fashion. The amount of balling was classified subjectively as `severe`, `moderate`, and `slight`, presenting problems in repeatability as well as a uniform means to quantify the amount of cuttings stuck on the bit.
Hemphill and Clark (1991) conducted full-scale experiments in the laboratory to observe the effect of different drilling fluids on balling in the laboratory. They further utilized the variation of the drilling torque as an indicator of the balling phenomena, pointing out the fact that when a bit got severely balled up, the torque decreased correspondingly.
Zijsling and Illerhaus (1991) documented the field performance of the "Egg-Beater" bit designed especially for the prevention of the balling. The project necessitated testing of the product in the field under controlled conditions.
Holster and Kipp (1984) conducted full-scale drilling studies in Mancos and Pierre shales and have described the influence of hydraulics on the balling tendency. However, the conclusions drawn from this work was the fact that gumbo-type shales cannot be drilled effectively and balling cannot be prevented through hydraulics alone, especially so when PDC bits are being used.
All of the above tests involved an outlay of large amounts of time and money. Frequently, even for obtaining very few data points, tests involved the setting up of huge testing procedures and mounting large rock cores under carefully controlled environmental conditions. Frequently, even after running such large elaborate experiments, the interpretations are incomplete for want of more data which demand the need for running of many such similar experiments to even form a `trend` of data that can be interpreted with confidence. In this manner the entire process becomes an extremely tedious and tiresome research exercise.
SUMMARY OF THE INVENTION
In response to the above need in the art, for a process that provided a reliable and consistent methodology and apparatus for obtaining repeatable results quickly in the laboratory, the present invention provides a novel process and device.
A process is formulated for determining the likelihood and/or extent of bit-balling occurring in the presence of a specified formation material through which a borehole would be drilled and a specified drilling fluid which would be used to drill the borehole by providing a sample of the specified formation material or a similar substitute material; providing a sample of a specified drilling fluid or a similar substitute fluid. Providing a bob simulating a drill-bit; enclosing the bob and the formation material both submerged in the drilling fluid which is caused to circulate through a pump so that the same fluid recirculates during the entire duration of the test. The bit/stabilizer balling test would involve forcing the bob (simulating the drill-bit) against the formation material at a specified load (simulating a value to proportionally correspond to the weight-on-bit (WOB) being used in the field in normal or conventional drilling operations in the oil and gas industry) and rotating the bob at a constant speed (rpm) for a specified duration of time. The apparatus is instrumented to record the rotary torque during the rotation and also to record the rotary speed.
At the end of the specified duration of time of the test, the drilling fluid is drained away and the bob is removed from the spindle and weighed from which the amount of cuttings stuck on the faces and the amount of cuttings stuck in the slots of the bob are calculated separately and recorded providing a quantitative estimate of the degree of balling through the amount of cuttings stuck to the faces as well as stuck inside the slots of the bob.
The complete apparatus comprising a bob simulating a bit; the bob comprising eight different cutting faces, one part of each of which is inclined at a specified negative rake angle (FIG. 3) forming into a slot, and the other side of which forms two faces at specially inclined relief angles (FIG. 3); the entire bob formed out of material 440C steel and subsequently heat treated to required specifications; a holder for holding the rock sample, a chamber enclosing the rock sample, holder and also the drilling fluid, a fluid inlet and a fluid outlet to the chamber for circulating a drilling fluid in contact with the bob and the rock sample, means for pumping the circulating fluid, means for rotating the bob, means for applying different loads on the rock through the bob, means for measuring and recording data like rotary torque and rotary speed, means to mount samples in thermally insulated holders with the intention of maintaining the bob at particular specified polarity well isolated from rest of the apparatus, means to maintain the bob at a particular specified polarity in such a manner so as to isolate the rock sample from rest of the apparatus, a means for weighing the bob for determining the amount of rock cuttings adhering to the faces and stuck in the slots of the bob.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is the cross-section of the apparatus of the invention.
FIG. 2 is a front view of the apparatus of the invention.
FIG. 3 is the front view of the first bob known as Design 1 of the invention with the following descriptive parameters:
Rake Angle=-8.5 degrees
Relief Angle I=8.5 degrees
Relief Angle II=20.0 degrees
FIG. 4 is the front view of the second bob known as Design 2 of the invention with the following descriptive parameters:
Rake Angle=-8.5 degrees
Relief Angle I=8.5 degrees
Relief Angle II=25.0 degrees
FIG. 5 is the front view of the third bob known as Design 3 of the invention with the following descriptive parameters:
Rake Angle=21.5 degrees
Relief Angle I=8.5 degrees
Relief Angle II=20.0 degrees
FIG. 6 is the front view of the fourth bob known as Design 4 of the invention with the following descriptive parameters:
Rake Angle=21.5 degrees
Relief Angle I=8.5 degrees
Relief Angle II=30.0 degrees
FIG. 7 is the front view of the fifth bob known as Design 5 of the invention with the following descriptive parameters:
Rake Angle=21.5 degrees
Relief Angle I=8.5 degrees
Relief Angle II=25.0 degrees
FIG. 8 is the front view of the sixth and optimized bob known as Design 6 of the invention with the following descriptive parameters:
Rake Angle=-38.5 degrees
Relief Angle I=8.5 degrees
Relief Angle II=20.0 degrees
FIG. 9 provides test results showing the amount of balled-up cuttings.
FIG. 10 shows a plot of Number of Tests versus Weight of Stuck Cuttings.
FIG. 11 shows the amount of stuck balled cuttings of Pierre II shale rock.
FIG. 12 shows test results that indicate improvement (reduction) of bit-balling amount due to DRILLFREE additive.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The test procedure of the invention involves preparation of a sample such as a rock sample which may be shale, sandstone, etc., and a test fluid such as a drilling fluid that is well known to the art, mounting the sample in the test cell and adding the test fluid which is circulated through the cell during the duration of the experiment; rotating the bob which has been described earlier above, against the rock sample under a specified load for the specified duration of the experiment, draining the test fluid, removing the cell and then removing the bob and weighing the bob with the stuck/adhered rock cuttings to it and recording the weight, then carefully removing the stuck cuttings from the faces of the bob alone and weighing for a second time and record the second weight and then carefully remove the stuck cuttings from the slots of the bob and then weighing for a third time and record the third weight; then clean bob of all remaining cuttings from both faces and slots with water and then weigh for fourth time the dry bob alone and record fourth weight; the difference between first weight and second weight providing the amount of balling on the faces alone; the difference between second weight and third weight providing the amount of balling in slots; the difference between third weight and fourth weight providing the amount of stuck cuttings remaining on both faces and slots combined, provides the amount of balling on the faces, slots and remaining balled cuttings, respectively.
As shown in FIGS. 1 and 2 a test cell housing 1 is provided which encloses a bob or cutter 2 and a rock sample 3. The bob is rotated by a main shaft or spindle 4 which extends through the wall of the test cell housing. The rock sample 3 is forced against the bob 2 by load shaft 5, which is under pressure from a load 6. Fluid inlet 7 and fluid outlet 8 are provided for circulating a test fluid such as a drill fluid through the test cell housing and into contact with the bob and the rock sample.
As explained above, after the apparatus has been run for a period of time with the bob rotated against the rock sample, the device is then shut down, the circulation of the fluid is stopped and the fluid drained from the test chamber, the bob is removed from the main shaft/spindle and weighed. After the cuttings from the faces and slots have been removed step by step and weighted between each removal operation of the balled up cuttings, the differences between each previous weighing and the subsequent weighing indicates the amount of bit-balling occurring for the bit-like bob under the particular set of controlled experimental parameters used for the particular experiment.
The following tests were conducted to study the phenomenon of bit/stabilizer balling utilizing the said test apparatus and bob.
EXAMPLE 1
This test was conducted to determine which of the above listed bob designs (1 through 6) would be heavily balled with cuttings and which would be cleaner.
Bit/stabilizer balling test was conducted using each of the six designs using identical pieces of Pierre II shale as rock specimen in fresh water as the drilling fluid for the same duration of time. The amount of balled cuttings were measured at the end of the experiment for each bob on the faces, slots and after flushing with water. The test parameters are as below.
______________________________________Weight-on-bob 50 lbRPM 75Fluid Fresh WaterDuration 120 secRock Pierre II Shale______________________________________
SUMMARY OF TEST RESULTS
The results are illustrated in FIG. 9. The test results provided excellent results. The amount of balled up cuttings on the faces varied from 2 gm for Design 4 to about 25 gm for Design 5. The amount of balling for Design 6 the optimized design was about 22 gm. The balled up shale cuttings were extremely sticky and difficult to remove. The balling for the other Designs 1, 2 and 3 was about 14 gm, 2 gm and 12 gm, respectively. For Design 2 the amount of balling in the slots was observed to be more than on the faces.
EXAMPLE 2
This test was conducted to examine consistency and repeatability of balled experimental data. It was found that the bob which provided the most consistent and repeatable data was Design 6. After a number of tests have been run on the this bob, at various test parameters and durations at periodic intervals the `control` test was run with the following test conditions.
______________________________________Weight-on-bob 50 lbRPM 75Fluid Fresh WaterDuration 120 secRock Pierre II Shale______________________________________
SUMMARY OF TEST RESULTS
The test result is shown in FIG. 10. The plot of Number of Tests versus Weight of Stuck Cuttings shows excellent repeatability of the balled up amount for identical experimental conditions. The amount of balled up cuttings on the faces remains around an average value of about 21 gm even after about 70 tests with the bob under different conditions of weight and rpm. The same trend with the amount of stuck cuttings in the slots is noticed, remaining constant at about 5 gm.
EXAMPLE 3
This test was conducted to examine the effectiveness of the process of electro-osmosis in the prevention of bit/stabilizer balling. Here the rock sample was held in an insulated rock holder and maintained at a positive potential with respect to the bob at +10 VDC. The bob was connected to the negative terminal of the 10 VDC power supply making it the cathode. The test parameters were as below.
______________________________________Weight-on-bob 50 lbRPM 75Fluid Fresh WaterDuration 120 secRock Pierre II ShaleVoltage 10VDC______________________________________
SUMMARY OF TEST RESULTS
The test results are shown in FIG. 11. The figure shows the amount of stuck balled cuttings of Pierre II shale rock on the faces, slots and after cleaning with water for both the conditions viz. when no electo-osmosis was applied and when a 10 VDC potential was applied making the bob the cathode.
It is clearly seen that the amount of balling on the faces is reduced from 20 gm to about 7 gm, a reduction of about 65%. The amount of balling in the slots is reduced to by about 20% through this novel process for prevention of bit/stabilizer balling called electro-osmosis.
EXAMPLE 4
This series of four tests were conducted to examine the effectiveness of a particular drilling additive to the drilling fluid, as well as the effect of electro-osmosis in the prevention of bit-balling. The tests were:
(i) Control, which involved conducting balling test in the specified drilling fluid without any additives or electro-osmosis.
(ii) Additive was the balling test with the drilling fluid containing additive DRILLFREE by MI Drilling Fluids (75 lb/bbl).
(iii) Electro-Osmosis (EO), which consisted of the test with maintaining the bob at a negative electrical potential with respect to the rock sample maintained at 10 VDC in the drilling fluid containing no DRILLFREE.
(iv) Mud+EO+DRILLFREE consisted of the test for balling of the drilling fluid containing the additive DRILLFREE of 0.75/bbl concentration combined with electro-osmosis at 10 VDC maintaining the bob at a negative potential of 10 VDC with respect to the rock sample. The test conditions are shown below:
______________________________________Weight-on-bob 50 lbRPM 75Duration 120 secVoltage 10VDCFluid Frsh WaterRock Pierre II ShaleAdditive DRILLFREE______________________________________
The test results are shown in FIG. 12.
From the results it is seen that DRILLFREE reduces the amount of bit-balling from 22 gm (Control) to about 15 gm, a reduction of about 32%. Electro-osmosis alone reduces the amount of balling on the faces by about 41%. When electro-osmosis and the fluid additive both are used, the total reduction in balling is from 22 gm to about 7 gm; 68%. These test results indicate that the amount of bit/stabilizer balling can be measured and quantified.
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A novel process and apparatus have been contrived for the study of the bit/stabilizer balling phenomenon in the laboratory. The device permits a standard testing procedure using a specially designed bob simulating the drill bit for comparing degrees of balling for different rock formations under different drilling conditions involving variable and controlled parameters like weight-on-bit, revolutions-per-minute (rpm), drilling fluids, etc.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No. 10/924,240, filed Sep. 15, 2004, which claims priority to United Kingdom Patent Application No. 0321757.7, filed Sep. 17, 2003.
FIELD OF THE INVENTION
[0002] This invention relates to road safety barriers for use at the sides or central reservations of roads and motorways, and in particular these including a plurality of wire ropes interwoven and maintained under tension between supporting posts.
SUMMARY OF THE INVENTION
[0003] A known wire rope road safety barrier, described in EP 0 369 659 A1, includes two pairs of wire ropes, one pair of upper ropes supported in slots provided in a number of posts and lying generally parallel to one another, and a lower pair of ropes held in tension against and in contact with opposite side edge surfaces of posts. Each lower cable follows a sinuous path and passes to a different one of the two side surfaces of the same post. Although this safety barrier design added substantially to the containment capability over an earlier two wire rope barrier, it is now recognized that there are disadvantages associated with the parallel arrangement of the upper ropes because they have very little connectivity/cohesion with the posts. Consequently the upper ropes behave less stiffly and have less energy absorption capability than the (interwoven) lower ropes. Also because of the vertical rigidity of the posts there is a possibility of an errant vehicle straddling the safety barrier and receiving an upward thrust leading to overturning of the vehicle, if the posts fail to collapse in time.
[0004] It is desirable to achieve a degree of pre-tensioning of the interwoven wire ropes such that the integrity of the barrier is maintained during the mediate post-crash period. However, a consequence of the pre-tensioning is a tendency for the interwoven ropes to grip the posts so tightly that their combined frictional grip in the direction of the line of the barrier exceeds the elastic bending strength of the posts in that direction. This can lead to posts located some distance away from the vehicle impact zone being pulled over by the ropes towards the vehicle to the extent that they are permanently deformed.
[0005] It is an aim of the present invention to provide a road safety barrier which alleviates the aforementioned problems.
[0006] According to the present invention, there is provided a road safety barrier comprising four or more ropes supported by posts rigidly mounted on or in the ground, each rope being held in tension against the posts and following a sinuous path between the posts.
[0007] In embodiments of the invention, the tensioning of the ropes against the posts gives rise to a combined frictional resistance to displacement of the ropes relative to each post or at least some of the posts along the length of the safety barrier. The structure of each post and/or its/their mounting with respect to the ground defines a minimum bending yield strength in a direction along the length of the barrier. This minimum bending yield strength is advantageously greater than the bending moment resulting from the combined frictional resistance forces acting on the post.
[0008] Notwithstanding the above requirement it is highly desirable that all (or most) of the posts exhibit a preferential mode of collapse in a direction along the length of the safety barrier, relative to a transverse direction, so that they do not project from the line of the fence after an accident.
[0009] Embodiments of the present invention may provide an enhanced vehicle restraint capability relative to the four-wire rope fence described in EP 0 369 659 A1 particularly in cases involving larger and heavier vehicles. Further ropes may be interwoven between the posts to create a multi-rope barrier in order to achieve an increased containment capability although additional ropes to the minimum four are preferably added in pairs so the total number of ropes is even. This is so that the barrier has a more consistent resistance to vehicle penetration along its length. The ropes may be arranged in pairs at different heights on the posts or alternatively each rope may be at a different height from the others. In the latter case, the dispersion of the ropes allows the barrier to better accommodate a wide variety of vehicle types/heights and reduces the risk of rope redundancy in terms of vehicle capture.
[0010] Rope supports may be provided on the posts for vertically locating the ropes thereon while permitting longitudinal movement in the direction of the plane of the barrier. The rope supports may be formed integrally in the posts, possibly by way of longitudinally disposed notches. Alternatively the ropes may be supported on frangible supports such as rollers mounted on the posts.
[0011] The posts may have an asymmetrical cross-sectional profile such that the post presents the same profile to oncoming traffic on both sides of the barrier. This is, when the post is installed in the ground, rounded corners of the post are presented to oncoming traffic travelling in opposite directions on either side of the barrier. For example, the cross-sectional profile of the post may be of “S” or “Z”, preferably with rounded corners on the line of the bend so that a rounded corner is presented to oncoming traffic. The S-post is therefore to be preferred in the central reservation of dual carriageways where vehicles drive on the left-hand side of the road, whereas the Z-post is preferable in the near-side verges. The opposite choice would naturally prevail in right-hand drive countries.
[0012] Embodiments of the present invention are advantageous in that when a vehicle impacts the barrier, there is an enhanced vehicle containment/retardation capability and a reduced risk of post collapse or damage in the regions of the barrier up and downstream of the impact area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention will now be further described by way of example with reference to the accompanying drawings, in which like reference numerals designate like elements, and in which:
[0014] FIG. 1 shows part of a road safety barrier described in EP 0 369 659 A1;
[0015] FIG. 2 shows a section of a road safety barrier according to a first embodiment of the present invention;
[0016] FIG. 3 shows a section of a road safety barrier according to a second embodiment of the present invention;
[0017] FIGS. 4 a to 4 c show a rope support which may be adopted in embodiments of the present invention;
[0018] FIG. 4 d shows an alternative rope support which may be adopted in embodiments of the present invention;
[0019] FIG. 5 is a graph showing frictional resistance between ropes and posts due to interweaving; and
[0020] FIG. 6 is a graph showing tension fall-off due to rope interweaving.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] In the arrangement shown in FIG. 1 , posts 1 , 2 and 3 are inserted into the ground (not shown) and support two pairs of wire ropes 4 , 5 and 6 , 7 . The posts may be inserted into the ground either into recesses in pre-cast footings or by any other suitable means. The posts may be made from steel pressings having, for example, an “S” or “Z” cross-section such that a rounded corner of the line of the bend is offered to the direction of the traffic instead of a sharp edge. In addition the post shape will preferably present a smooth conforming surface to the ropes, and a smooth radiussed surface to any other impacting bodies so as to minimize the damage thereto under collision conditions.
[0022] The ropes 4 , 5 of one pair are lying parallel to one another and supported within notches 8 , 9 and 10 provided within respective posts 1 , 2 and 3 . The ropes 6 , 7 of the other pair are interwoven between the posts in the manner illustrated and supported in a vertical direction on the side of the posts by way of supports 11 , 12 and 13 . Each rope is maintained under tension so that the barrier provides an effective restraint to errant vehicles.
[0023] In the first embodiment of the present invention, as illustrated in FIG. 2 , the ropes of both pairs 4 , 5 and 6 , 7 are interwoven about the posts 1 , 2 and 3 instead of only the lower pair 6 , 7 . Each of the ropes is supported in a vertical direction on the side of the posts by way of supports 11 , 12 and 13 . The ropes of the first pair 4 , 5 are at substantially the same height above the ground as one another and the ropes of the second pair 6 , 7 are also at substantially the same height above the ground as one another but lower than the first pair. In the second embodiment, illustrated in FIG. 3 , all of the ropes 4 to 7 are interwoven but instead of being arranged in two pairs vertically spaced apart from one another, all of the ropes are vertically spaced apart with respect to one another at different heights above the round. The first and second embodiments have the advantage, relative to the prior art arrangement illustrated in FIG. 1 , that the containment capability of the barrier is improved and the risk of an impacting vehicle overturning is reduced for a wider range of vehicle weights and sizes. It is noted that FIGS. 2 and 3 illustrate a preferred method of interweaving in that each of the ropes passes from one side of the first post to the alternate side of the next one and so on progressively along the length of the barrier. It is preferred for the interweaving of half of the ropes to be arranged out of phase with the other half and in a manner which balances the potential bending moments on the respective posts, to ensure a consistent resistance to penetration (by vehicles) along the length of the barrier.
[0024] FIGS. 4 a to 4 c show rope supports which may be advantageously adopted in the posts of the embodiments of FIGS. 2 and 3 . FIG. 4 a shows a keyhole slot 15 formed in the wall of the post 1 . A support roller 16 is mounted within the keyhole slot 15 and held therein by spigot 17 . The roller 16 supports the wire rope 4 so that it is free to slide in the longitudinal direction of the safety barrier and free to move upwardly in the event of a vehicle impact. The roller supports are preferably frangible so that, in the event of a vehicle impact in which the posts fail to collapse towards the ground, the ropes are able to become detached from the posts more easily. Instead of supporting the ropes by way of the support roller 16 illustrated in FIGS. 4 a to 4 c , the ropes could be supported by a simple protuberance formed in the surface of the post.
[0025] Alternatively, as illustrated in FIG. 4 d which shows a part view of the post 1 , the rope 4 may be located within shallow and longitudinally orientated grooves/depressions or notches 20 provided in flanges of the post section. This enables smooth supporting of the ropes as well as simple and accurate positioning thereof at predetermined heights on the one hand while allowing the ropes to be released from the notch if a significant vertical force is exerted on the rope. The release of the rope from the post 1 when subjected to an upward or downward force avoids them applying any upthrust to the vehicle and the possibility of the post 1 being pulled out of the ground.
[0026] Each of the ropes 4 to 7 is pre-tensioned by means of ground anchors at suitable intervals along the highway. The tension may be applied, for example, by temporary jacking means and adjustable rope anchorages, or by threaded end connectors and bottle screws (not shown). Intermediate tensioning means may be introduced to permit the end anchorages to be more widely separated.
[0027] During installation of the safety barrier, steps should be taken to ensure that the pre-tensioning of the wire ropes 4 to 7 is such that the tension is uniformly distributed along the barrier between the anchorage points.
[0028] In a preferred embodiment of the present invention, the yield strength of the posts in the longitudinal direction of the safety barrier exceeds the combined bending moments due to the normal frictional forces of the ropes on the posts under the expected tensions in the system. The significance of the post-rope frictional resistance and its bearing on the performance of the safety barrier will be explained in more detail below under the heading “Safety Barrier Crash Performance”.
[0029] The posts should be designed to be secured in the ground in a manner capable of resisting the (longitudinal and transverse) bending moments on the post prior to and during its collapse under vehicle impact conditions, having regard to the prevailing ground conditions.
[0030] The post cross-section may be of any size and shape which satisfies the above criteria, and may vary in dimensions along the length of the barrier to reflect differing requirements, e.g. curves in the highway and/or changing post spacing.
[0031] Examples of Possible Z-Post sections:
[0000] Superficial dimensions of 2 nd Moment of Inertia mm 4 post cross-section mm In plane of Depth Width Thickness barrier Normal to barrier 100 32 5.0 59,000 914,000 100 32 6.0 66,700 1,064,000 100 40 6.0 125,000 1,280,000 110 40 6.0 130,000 1,625,000 110 50 6.0 242,000 1,960,000 120 40 6.0 135,000 2,016,000 120 50 6.0 245,000 2,420,000 120 50 8.0 307,000 3,070,000
It may also vary in flexural stiffness along the length of the post to take account of the varying bending moment. The type of section will therefore preferably lend itself to being manufactured by processes which can readily accommodate changes in size and shape without incurring prohibitive costs for tooling and the like.
[0032] The posts shall be of such a cross-section that they not only provide the barrier with adequate resistance to vehicle penetration (transverse to the line of the barrier) but also have a preferential mode of collapse in the direction of the line of the barrier. This is achieved by making the second moment of area of the posts in the longitudinal direction (in the plane of the barrier) significantly less than its second moment of area in the transverse direction (normal to the barrier) as illustrated in the above table. In order to comply safely with this requirement it is expected that the depth of the post cross-section is preferably in the region of 2-3 times the width thereof.
[0033] The constructional design detail of the rope tendons is believed non-critical to the initial functionality of the barrier so long as the ultimate strength and axial stiffness of the ropes are correctly specified, in keeping with the expected (crash) performance of the barrier. However the 19 mm diameter 3×7(6/1) rope is commonly used at present in this application and is a suitable rope for use in barriers embodying the present invention. This type of rope is favored both for ease of manufacture/handling, and for its structural integrity when subjected to mechanical abrasion/abuse. In addition it is substantially torque balanced under load which facilitates pre-tensioning and avoids undesirable rotational displacements in service.
[0034] However to optimize the functionality of the barrier in the immediate post-crash period steps should be taken to minimize the loss in rope tension when the barrier is impacted by a vehicle. In addition to ensuring that the barrier is uniformly pre-tensioned along its length, the ropes should be pre-stretched at a tension equivalent to 50% of their breaking strength, to remove initial stretch and elevate the elastic limit of the wire rope. Typically such ropes will have a minimum breaking strength of 174 kN and an axial stiffness of at least 23 MN.
[0035] The level of pre-tension applied to the wire ropes during installation of the barrier maybe regarded as an important variable in determining the crash performance of the barrier, with particular regard to vehicle deceleration rates and the permissible level of penetration beyond the line of the barrier. Normally for effective containment the ropes will be pre-tensioned to a tension equal to at least 10% of their breaking strength, and preferably to a tension equivalent to about 15% of their breaking strength and even up to a level equivalent to about 20% of their breaking strength where other design and practical considerations allow.
[0036] Safety Barrier Crash Performance
[0037] The use of parallel top ropes in the prior art barrier illustrated in FIG. 1 is advantageous in that it is easy to apply and maintain tension in those elements of the system. Specifically, the frictional resistance between the ropes and the post slots (in which they are a loose fit) is so low that that tension is readily transmitted over long lengths simply by tightening up the bottle screws at the anchorage points. This has the added benefit that in the event of a vehicle collision with the fence, there is little loss in tension in the top ropes and their functionality is largely maintained, thus preserving the integrity of the barrier until repairs can be effected. On the other hand, the use of interwoven top ropes increases the dynamic stiffness of the barrier and its energy absorption capability, thus improving the primary safety of the barrier.
[0038] Embodiments of the invention adopt interwoven ropes in place of the prior art parallel top rope arrangement. However, interwoven ropes are more difficult to pre-tension, because the angular deflection of the ropes creates a proportional increase in the frictional resistance to movement between them and the posts. Typically the ropes are deflected from the line of the barrier by 2-3 degrees, but at shorter post spacing the angular deflection increases rapidly and may reach 5 degrees or more. The effect of this on the frictional resistance between the ropes and the posts is illustrated in FIG. 5 below. This figure takes the example of a 19 mm (¾″) dia. rope on 100 mm (4″) deep posts, and assumes a coefficient of friction=0.20.
[0039] This tensioning difficulty can be overcome by adopting an iterative tensioning procedure. The ropes may be tensioned up to or slightly beyond the desired level at the anchorage or tensioning points, and then the intervening posts (in the direction of the line of the fence) may be disturbed so as to promote rope slip and the re-distribution of the tension. This procedure is repeated to effect a progressive tensioning of the whole fence stage, up to the desired level.
[0040] Notwithstanding the effectiveness of this technique, the interwoven ropes suffer a significant loss in local tension when posts are collapsed by an impacting vehicle, as the angular (zigzag) deflection of the ropes is removed in the area of the collision. FIG. 6 (below) illustrates this effect graphically by considering one (or more) post bays in isolation from the rest of the fence and assuming that the ropes are initially pre-tensioned to 20% of the breaking strength (B/S) of the ropes.
[0041] This is admittedly a worst case scenario and in practice a considerable amount of these tension losses will be taken up by the undisturbed rope in the adjoining fence bays. Nevertheless the residual tension in the ropes will be significantly less than if they had not been interwoven. This emphasizes the need for effective pre-tensioning of the ropes to the recommended level, if a degree of barrier integrity is to be maintained in the immediate post-crash period.
[0042] A consequence of these effects is that the interwoven ropes will tend to grip the posts tightly such that their combined frictional grip in the direction of the line of the fence exceeds the elastic bending strength of the posts in that direction. When interwoven upper ropes are introduced, there is therefore the prospect of posts being pulled over by the ropes in positions not directly affected by an impacting vehicle. This presupposes that the rope displacements are sufficiently large to induce flexural yielding of the posts. Significantly the direction of this movement will be towards the colliding vehicle. Therefore, in accordance with a preferred aspect of the present invention, the posts are constructed and/or their attachment to the ground is such that the yield strength in bending of the posts (in the direction of the line of the fence) exceeds the combined bending moment of the rope frictional forces.
[0043] The move to a fully interwoven barrier system in accordance with the present invention further alleviates this problem. Embodiments may be provided with means for supporting the ropes, which are frangible at the posts. In the embodiment illustrated with reference to FIGS. 4 a to 4 c , the (roller) supports are mounted on spigots which readily shear in the event of substantial downward forces being applied.
WORKED EXAMPLE
[0044] Consider the case of a 4-rope interwoven barrier in which the ropes have a mean heist above ground level of 550 mm and posts at 2.4 m spacing, each having a depth of 100 mm. The resulting angular deviation of the ropes (in plan view relative to the line of the barrier) will be 2.38 degrees. If we assume for design purposes that each rope will see a tension of 50 kN, then it can be shown that the four ropes will generate a frictional grip on a post of 3.33 kN (taking the coefficient of friction to be 0.20). The effect of this force is to create a bending moment in the post which will reach a maximum of 1832 Nm (at the base of the post) before the ropes slip. The result of this bending moment in terms of maximum bending stress will vary with the strength and stiffness of the type of post selected as illustrated in the table below:
[0045] Comparison of Maximum Bending Stresses in Z-Posts at 2.4 m Centres:
[0000]
In-line
Combined
Post dimensions mm
moment of
bending
Maximum bending
D × W × Thickness
inertial mm 4
moment Nm
stress N/mm 2
100 × 32 × 6.0
66,700
1832
439
100 × 40 × 6.0
125,000
1832
293
120 × 50 × 6.0
245,000
2197
224
[0046] [assumes 50 kN rope tension and 550 mm mean rope height]
[0047] With the Standard (100×32×6 mm) post it was found that the maximum bending stress greatly exceeded the yield strength of the post, which is 275 MPa [for Fe430A grade material]. The use of a larger (100×40×6.0 mm) post was therefore considered but the maximum bending stress still marginally exceeded the Fe430A yield strength. In this instance the problem could be solved by using a higher grade of steel post, e.g. Grade Fe510A which offers a yield strength of 355 MPa. A possible alternative solution would be to use a yet larger post such as the 120×50×6 mm section. Whilst this increases the angular deviation of the ropes and the bending moment slightly, the maximum bending stress falls to 224 MPa, well below the normal yield strength of 275 MPa.
[0048] Although intuition would suggest that post failure would be caused by direct impact of a colliding vehicle on the post, it appears that (for a pre-tensioned wire rope safety barrier) the mode of collapse of the posts is more generally attributable to the longitudinal components of the tensions in the ropes, as they are deflected by the ingress of the vehicle beyond the line of the barrier. The angular deflection of the ropes increases rapidly as the vehicle approaches the (first) post, up to the point at which the yield point of the post is reached, whereupon the ropes are released from the first post, to apply a similar progressive force (and bending moment) to the next post in line.
[0049] In an interwoven barrier, only the ropes that are on the upstream side of the post in question (i.e. lie between it and the oncoming vehicle) can act to pull it down. Hence, provision of an even number of ropes would render the barrier to a more consistent resistance to vehicle penetration along its length. Similar considerations apply to the selection of an optimum interweaving pattern for the ropes, if the ropes are not being paired at the same height.
[0050] It is noted that in embodiments of the present invention, the aforementioned problem of posts being pulled over is less apparent in the regions of the barrier close to the ends where the ropes are anchored to the ground. This is because at posts close to the barrier ends, the effective stiffness of the ropes increases due to the relatively short length thereof between the post in question and the anchorage point. Consequently, the ropes near the end positions of the barrier tend to deflect less under crash conditions relative to positions further away from the ends. As a result the frictional resistance of the ropes against the posts in these positions is less likely to deflect the post sufficient to cause yielding in bending. Therefore, posts near the anchorage ends of the barrier need not necessarily comply with the minimum bending yield strength of the present invention.
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A road safety barrier having a plurality of ropes supported by posts rigidly mounted on or in the ground is described. Each rope is held in tension against the posts and supported in a notch or groove in a side of the posts. The ropes are released from a post and the post is not pulled from the ground when a vertical force is exerted on the rope. The ropes when weaved are tensioned against the posts and this gives rise to a combined frictional resistance to displacement of the ropes relative to each post along the length of the safety barrier. The structure of at least some of the posts and/or their mounting with respect to the ground defines a minimum bending yield strength in a direction along the length of the barrier. This minimum bending yield strength is greater than the bending moment resulting from the combined frictional resistance forces acting on the post.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to PCT Application entitled “Robust 1D Gesture Light Control Algorithm,” having serial number PCT/CN2007/003050, filed on Oct. 26, 2007, which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a lighting system comprising a lamp arranged to transform electricity into a light beam having properties such as intensity, colour, colour temperature, direction and beam cone angle, and a light control means arranged to adjust said light beam properties.
BACKGROUND OF THE INVENTION
[0003] Adjustment of a lamp's properties is well known to be achieved via a remote control (RC). A disadvantage of a remote control is the necessity of the presence of the remote control on the right location at a random moment. Also a lot of different remote controls are already present in the living room for TV, audio, VCR, CD/DVD player/recorder, etc. Further, the different buttons on a remote control can be confusing to the user. Finally, the costs of a remote control and the accompanying receiver are relatively high.
[0004] Also control of electrical devices by the use of video cameras and movement detection software is known, wherein the user can control the electrical device by making gestures in front of the camera. Such systems require heavy duty processing power, have a relatively long response time, and are relatively expensive.
[0005] WO 2006/056814 describes a lighting system comprising a lamp and a control means comprising an infrared transmitter, an infrared receiver and a lens arrangement. The control means measure the intensity of the reflected infrared light, and changes the lamp brightness in reaction thereto. In this manner the lamp can be switched on and off, and can be dimmed by hand movements in the infrared beam. Such an arrangement is however relatively expensive and inaccurate, as the intensity of the reflected infrared signal heavily depends on the kind of object that is moved in the beam.
[0006] It is a goal of the invention to provide an improved, cheap, reliable and easy-to-use control system for lighting. A further goal of the invention is to provide a lighting system that is safe and comfortable for its users and their environment.
SUMMARY OF THE INVENTION
[0007] According to the invention the lighting system further comprises an ultrasonic transmitter arranged to transmit ultrasonic signals, an ultrasonic receiver arranged to receive reflected ultrasonic signals, and a processing means arranged to derive a time-of-flight signal representing the time differences between said transmitted and received ultrasonic signals and to send control signals, for instance binary code, to said light control means in dependence of said time-of-flight signal. Thereby a user of the system can adjust the lamp properties by moving an object, such as his hand, in the ultrasonic beam.
[0008] The ultrasonic transmitter may for instance emit sound at a frequency of 40 kHz. Although alternatives to the use of ultrasonic transmitters/receivers, such as for instance infrared or radar transmitters/receivers would be capable of measuring the time-of-flight of the respective signals, ultrasound is in particular suitable for the present application, since the time-of-flight (where the typical distance is between 0.2 and 2 meter) can be measured in milliseconds rather than in nanoseconds, which allows for easy and accurate measurement with low cost processing equipment. The system of the invention can be produced at very low cost, since piezoelectric acoustic transducers are very cheap.
[0009] GB-A-2 291 289 describes a lighting system comprising a control means for switching a lamp on and off and for dimming the lamp, wherein piezoelectric ultrasonic transmitters and receivers are used to detect the presence of an object in the vicinity of the lamp, and said control means is arranged to react to the presence of said object. This system does however not use time-of-flight measurements of the ultrasonic signal, and thereby is not able to react to movement of the object.
[0010] The system of the invention is easy to control, with a simple user interface which does not require additional equipment such as a remote control. Other qualities of the system of the invention are its robustness, its independency from environmental conditions, its one-dimensional recognition of control movements, and its low processing power requirements. The further advantage of an ultrasound sensor is that it is less influenced by changing ambient light, temperature and humidity conditions.
[0011] The processing means is preferably arranged to analyse the dynamic behaviour of said time-of-flight signals and to send control signals to said light control means in dependence of said dynamic behaviour. Thereby the user can make gestures in the ultrasonic beam that will be recognised by the processing means and translated into control signals.
[0012] Said processing means is preferably arranged to stop sending control signals if said time-of-flight signal changed from dynamic behaviour to a value that has been substantially constant for a first predetermined period of time, said first predetermined period of time preferably being in the range of 0.5-2 s. By switching off the sending of control signals it is possible to prevent accidental adjustment of the lamp properties by a moving object. In order to turn the sending of control signals on, said processing means is further preferably arranged to determine and store a highest reference value, which reference value is determined as the value that has been present during most of a second predetermined longer period of time of for instance several minutes, and said processing means is then further arranged to start sending control signals if said time-of-flight signal changed from said highest reference value to a lower value that has been substantially constant for at least a shorter third predetermined period of time, said third predetermined period of time preferably being in the range of 0.5-2 s.
[0013] In the preferred embodiment said lamp is a spotlight type lamp arranged to emit a light beam having a beam cone angle θ smaller than 45°, preferably smaller than 30°. Said beam cone angle of the transmitted ultrasonic signals is preferably smaller than 15°. To that end said ultrasonic transmitter may comprise a horn for reducing the beam cone angle of the transmitted ultrasonic signals.
[0014] In the preferred embodiment said ultrasonic transmitter and receiver are arranged to transmit and receive ultrasonic signals in a direction extending within the light beam of the lamp. The light source of said lamp is preferably a plurality of LEDs, wherein said ultrasonic transmitter and receiver preferably extend substantially between said plurality of LEDs.
[0015] Said ultrasonic transmitter and receiver, processing means, and/or light control means, preferably extend in the lamp housing, and said ultrasonic transmitter and receiver preferably are a combined ultrasonic transducer. Thereby a compact and easy to install lighting system is provided, that is intuitively controlled by moving one's hand in the centre of the light beam. The invention also relates to a single lamp unit comprising the entire lighting system as described above.
[0016] According to a further aspect of the invention, in order to adjust the sound pressure of the ultrasonic transmitter to an acceptable, un-harmful and comfortable level for the users of the lighting system and their environment, said processing means is further arranged to perform a sound pressure level calibration step wherein the amplitude of the received reflected ultrasonic signal of the receiver is measured and wherein the amplitude of the transmitted ultrasonic signal of the transmitter is adjusted such that the amplitude of the received reflected signal approximates a predetermined threshold value. The amplitude of the received reflected ultrasonic signal in a certain situation depends on the transmitted amplitude, the distance-of-travel, the environmental absorption (e.g. absorption of ultrasound by air), and the diffraction by the reflecting reference surface (e.g. a fixed table, floor, etc.). In a certain situation for the period that the lamp is switched on it can be assumed that the absorption and diffraction are either constant if no object moves into the ultrasonic beam, or that the received amplitude will increase because the reflecting object is closer to the ultrasonic receiver, and therefore after calibration the transmitted amplitude can remain constant while it is more or less ensured that the received signal is always higher than the required threshold. In case however that after calibration the lighting system does (sometimes) not react to control gestures of the user, the user can be instructed to calibrate the system while holding the control object (f.i. his hand) at the farthest point he is expecting to put said object for controlling the system.
[0017] The transmitted and received sound pressure levels are measured in dB, but can be represented by a voltage, for instance the voltage put on the ultrasonic transmitter or the voltage received from the ultrasonic receiver. The maximum permissible exposure to 40 kHz ultrasound for instance is set by various organisations around 100 dB. The invention aims however at much lower levels than this, and will adjust the pressure level to a minimum, yet optimum level.
[0018] In order to further reduce the influence of the acoustic pressure on the users, the system is arranged to transmit said ultrasonic signals intermittently in short (preferably max. 100 ms) intervals.
[0019] Said processing means is preferably arranged to perform said sound pressure level calibration step in a short period, for instance within the first few seconds, after the lamp is switched on. Further said processing means is preferably arranged to start deriving said time-of-flight signal and sending control signals after said sound pressure level calibration step. Furthermore preferably said processing means is arranged to repeatedly perform said sound pressure level calibration step while it is deriving said time-of-flight signals and is sending said control signals to said light control means. Thereby a dynamic calibration of the sound pressure level to the lowest level that is necessary to operate the system is achieved.
[0020] In order to achieve the minimum necessary sound pressure level for the system to work properly, said processing means is preferably arranged to start said sound pressure level calibration step with a first calibration cycle wherein the ultrasonic transmitter is caused to send an ultrasonic pulse with a predetermined lowest amplitude and wherein the amplitude of the received reflected signal is measured, and to repeat said calibration cycle with a transmitted amplitude that is increased in each subsequent cycle with a predetermined value as often as necessary until the amplitude of the received reflected signal is equal to or higher than said predetermined threshold value. Said processing means is preferably arranged to cause a warning signal to be emitted by said lighting system, for instance a flickering of said lamp, if the amplitude of the received reflected signal is lower than said predetermined threshold value after a predetermined maximum number of calibration cycles.
[0021] There are several issues related to the robustness and reliability of a gesture light control system based on ultrasound. Reflections, diffraction, interference, noise may disturb the received signal. Other issues like a moved reference surface, other moving objects, multiple objects should be dealt with.
[0022] According to a further aspect of the invention, in order to provide a robust and reliable system, said processing means is further arranged to perform a reference calibration step, wherein the time-of-flight (TOF) is repeatedly measured a multitude of times, and wherein the processing means determines if the deviation of the majority of the measured time-of-flight values (TOFI) of said multitude of measurements is lower than a predetermined threshold (z), and wherein said processing means is arranged to calculate the average (TOFREF) of said measured time-of-flight values (TOFI) and store said average (TOFREF) in memory means as a reference time-of-flight value if said deviation is lower than said threshold (z). Said processing means is preferably arranged to generate an error signal if said deviation is not lower than said threshold (z).
[0023] Preferably said processing means is arranged to store said reference time-of-flight value (TOFREF) in said memory means only if said reference time-of-flight value (TOFREF) is greater than a predetermined minimum value. Said processing means is preferably arranged to generate an error signal if said reference time-of-flight value (TOFREF) is not greater than said predetermined minimum value.
[0024] Preferably said processing means is arranged not to store a reference time-of-flight value (TOFREF) in said memory means if during said reference calibration step no signal is received by said ultrasonic receiver during at least a predetermined number of time-of-flight measurements. Said processing means is preferably arranged to generate an error signal if during said reference calibration step no signal is received by said ultrasonic receiver during at least said predetermined number of time-of-flight measurements.
[0025] According to a further aspect of the invention, in order to provide a robust and reliable system, said processing means is arranged to perform a wait-for-control-enablement cycle wherein said time-of-flight (TOF) is repeatedly measured at predetermined intervals and to compare said measured time-of-flight value (TOF) with a reference time-of-flight value (TOFREF) which is stored in memory during said wait-for-control cycle, and to repeat said measurement if said measured time-of-flight value (TOF) is equal to or larger than said reference time-of-flight value (TOFREF), said processing means is further arranged to determine if the measured time-of-flight value (TOF) is smaller than said reference time-of-flight value (TOFREF) and if the deviation between the measured time-of-flight value (TOFH) and the previous measured time-of-flight value (TOFH−1) is lower than a predetermined threshold (tx), and said processing means is arranged to send control signals to said light control means in dependence of time-of-flight signals derived after it is determined that the measured time-of-flight value (TOF) is smaller than said reference time-of-flight value (TOFREF) and that said deviation is lower than said threshold (tx) for a predetermined number of repeated measurements.
[0026] Said predetermined interval is preferably substantially larger if it is determined that said measured time-of-flight value (TOF) is equal to or larger than said reference time-of-flight value (TOFREF), than if it is determined that said measured time-of-flight value (TOF) is smaller than said reference time-of-flight value (TOFREF).
[0027] Preferably said processing means is arranged to calculate the average of said measured time-of-flight values (TOF) and to store said average (TOFH) in memory means, and the processing means is arranged to send control signals to said light control means in dependence on the positive or negative difference between the measured time-of-flight (TOF) and said average time-of-flight (TOFH) after it is determined that said deviation is lower than said threshold (tx) for a predetermined number of repeated measurements.
[0028] Preferably said processing means is further arranged to clip the difference of the measured time-of-flight value (TOF) to a maximum allowed positive or negative difference between the measured time-of-flight (TOF) and said average time-of-flight (TOFH) for the purpose of determining the control signals to be sent to the light control means.
[0029] Preferably said processing means is further arranged to calculate said maximum allowed positive and negative difference such that the negative difference is smaller than said average time-of-flight (TOFH), and that the positive difference is smaller than the difference between said reference time-of-flight (TOFREF) and said average time-of-flight (TOFH).
[0030] Preferably said processing means is further arranged to adapt the determination of the control signals to be sent to the light control means such, that the full range of control signal can be achieved within the calculated range of the maximum allowed positive and negative difference.
[0031] According to a further aspect of the invention, in order to be able to adjust different light beam properties, said processing means and said light control means are further arranged to change from adjustment of one of said light beam properties to adjustment of another one of said light beam properties, if a predetermined behaviour in said time-of-flight signal is determined.
[0032] In a preferred embodiment said behaviour is a series of subsequently measured time-of-flight values that is substantially constant during a predetermined period.
[0033] In a further preferred embodiment said behaviour is a predetermined number of alternations of high and low measured time-of-flight values.
[0034] In a still further preferred embodiment said behaviour is a predetermined number of alternations of the presence and absence of measured time-of-flight values.
[0035] In a remote controlled lighting system it is desirable to provide feedback about the status and working of the system to the user in an efficient and low-cost manner.
[0036] The invention therefore further relates to a lighting system comprising a lamp arranged to transform electricity into a light beam having properties such as intensity, colour, colour temperature, direction and beam cone angle; a light control means arranged to adjust said light beam properties; a processing means arranged to send control signals to said light control means; a user control interface arranged to transform user control input into electronic input signals and to send those electronic input signals to said processing means; wherein said processing means is arranged to send a user feedback signal to said light control means such that said lamp properties either alternate in time or are different in adjacent locations, such that a user can recognize said alternating or adjacent different light properties as a feed back signal.
[0037] Preferably said processing means is arranged to send said user feedback signal to said light control means for a short period of time, for instance 0.2-5 seconds, and to send subsequently a signal to said light control means such that said lamp properties return back to the previous state or are set to a predefined steady state such as the switched off state.
[0038] In a preferred embodiment said feedback signal is such that the lamp intensity is visibly changed at least twice within said short period of time.
[0039] In a further preferred embodiment said feedback signal is such that the colour temperature is visibly changed at least twice within said short period of time.
[0040] In a still further preferred embodiments said lamp comprises an array of LEDs, wherein said light control means is arranged to individually power said LEDs in said LED array, and wherein said feedback signal is such that a visible sign such as a letter or an icon is formed in said array during said short period of time. Preferably said lamp comprises a lens to project said LED array on a reference surface. Said lens is preferably adjustably mounted in said lamp such that it is adjustable in dependence of the measured distance between the lamp and the reference surface.
[0041] In the preferred embodiment said user control interface comprises an ultrasonic transmitter arranged to transmit ultrasonic signals; an ultrasonic receiver arranged to receive reflected ultrasonic signals; wherein said processing means is arranged to derive a time-of-flight signal representing the time differences between said transmitted and received ultrasonic signals and to send control signals to said light control means in dependence of said time-of-flight signal. Said ultrasonic transmitter and/or receiver is preferably built-in in the centre of the lens.
[0042] It is desirable that the ultrasound controlled lighting system is easy to produce in mass quantities, with low cost components, and has small dimensions so that it can be built-in in even in a small lamp.
[0043] The invention therefore further relates to a lighting system comprising a lamp comprising an array of LEDs arranged to transform electricity into a light beam having properties such as intensity, colour, colour temperature; a light control means comprising a LED driver and a pulse width modulator arranged to adjust said light beam properties; a DA-converter, an ultrasound driver and an ultrasonic transmitter arranged to convert a digital transmit signal into the transmission of an ultrasonic pulse; an ultrasonic receiver and an amplifier arranged to receive reflected ultrasonic signals and transform said ultrasonic signal in a voltage, and a comparator arranged to generate a digital receive signal if said voltage is greater than a predetermined threshold; a processing means arranged to derive a time-of-flight signal representing the time differences between said digital transmit and receive signals and to send control signals to said light control means in dependence of said time-of-flight signal, wherein said processing means, said pulse width modulator, said DA-converter and said comparator are integrated in a single microcontroller chip.
[0044] Said microcontroller chip is preferably chosen from the single-chip 8-bit 8051/80C51 microcontroller family, preferably comprising small sized RAM and ROM, preferably smaller than 4 kB ROM and smaller than 512 B RAM.
[0045] Preferably said ultrasonic transmitter and said ultrasonic receiver are integrated in a piezoelectric ultrasound transducer.
[0046] Preferably said transmitting ultrasound driver and said receiving ultrasound amplifier are integrated in a pre-processing circuit. Said pre-processing circuit preferably further comprises a second order filter for filtering out low frequent signals from said received signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] The invention will be further explained by means of a preferred embodiment as shown in the accompanying drawings, wherein:
[0048] FIG. 1 is a graph showing the principle of time-of-flight measurement with an ultrasonic transceiver;
[0049] FIG. 2 is a schematic perspective view of the lamp and its control mechanism;
[0050] FIG. 3 is a combined drawing showing stills of hand movements in the system of FIG. 2 and a graph showing the time-of-flight signal against time, and various stages of lamp property control caused by said hand movements;
[0051] FIG. 4 is a schematic perspective view of the lamp of FIG. 2 ;
[0052] FIG. 5 is a schematic top view of an average hand;
[0053] FIG. 6 is a three-dimensional graph showing beam radius against beam angle and vertical distance;
[0054] FIG. 7 shows schematically the movement of a hand in and out of the beam and the related graph of the time-of-flight against time;
[0055] FIG. 8 is a schematic cross-sectional view of an ultrasonic transducer and a horn;
[0056] FIG. 9 is a flow chart showing the calibration process of the lamp system;
[0057] FIG. 10 is a combined drawing showing graphs of the voltage of the transmitted ultrasound pulse signals, the voltage of the received reflected signals and the status of the sound pressure level calibration in time;
[0058] FIGS. 11A-11C shows schematically the movement of a hand in and out of the beam;
[0059] FIG. 12 shows schematically the movement of a vase in the beam and the related graph of the time-of-flight against time and the various phases of control;
[0060] FIGS. 13-18 and 20 - 21 show flow charts of various control algorithms;
[0061] FIG. 19 schematically shows the determination of the control range;
[0062] FIG. 22 schematically shows the control mechanism of different light properties in time;
[0063] FIGS. 23-28 schematically show the control mechanism of different light properties in various stages;
[0064] FIGS. 29 and 30 show schematically the movement of a hand in the beam and the related graph of the time-of-flight against time;
[0065] FIG. 31 schematically shows a LED array lamp showing a message;
[0066] FIG. 32 schematically shows a LED array lamp projecting a message on a reference surface;
[0067] FIGS. 33 and 34 schematically show an electronic hardware implementation of the invention; and
[0068] FIG. 35 is a perspective view of a lamp according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0069] The lamp 1 as shown in FIG. 2 comprises a plurality of LEDs and an ultrasonic transceiver built-in in the centre of said plurality of LEDs. Also a processing means for translating the signals of the transceiver into control signals, and control means to adjust the light properties are built-in.
[0070] If the ultrasonic transceiver is switched on it will send an acoustic signal. If an object is present the acoustic signal will be reflected at the object and will be received by the ultrasonic transceiver inside the lamp. The time difference, called the time-of-flight, between sending and receiving the acoustic signal will be measured. If the distance between the object and the lamp 1 is changed another time-of-flight value will be measured. The detected movement of the object is a one-dimensional movement (the object must stay in the ultrasound beam cone). The change in time-of-flight will be translated into a change in a digital control signal. This control signal will control the properties of the light beam, like colour, intensity or colour temperature, etc.
[0071] The object may be the hand 2 of a user. Thus a one-dimensional movement of the hand 2 , like up/down or left/right direction (depending on lamp position, horizontal or vertical) can control the light beam properties.
[0072] In commercially available pulse echo distance measurement units of the transmitter-reflector-receiver type (TRR), the most common task is to measure the distance to the closest reflecting object. The measured time is the representative of travelling twice the distance. The returned signal follows essentially the same path back to a receiver located close to the transmitter. Transmitting and receiving transducers are located in the same device. The receiver amplifier sends these reflected signals (echoes) to the micro-controller which times them to determine how far away the object is, by using the speed of sound in air.
[0073] The time-of-flight of acoustic signals is commonly used as a distance measurement method. A time-of-flight measurement, as illustrated in FIG. 1 is formed by subtracting the time-of-transmission (T in FIG. 1 ) of a signal from the measured time-of-receipt (R in FIG. 1 ). This time distance information will be transferred into a binary code in the microprocessor to control the lamp properties.
[0074] In FIG. 2 a hand 2 is the obstacle/object and a table 3 , floor or ceiling is the reference. The ultrasonic transducer sends an ultrasonic wave in the form of a beam cone 4 . If the distance y from the transducer to the reference is 1.5 m, the total travel distance for the ultra-sound beam 4 is 2*y=3 m. The time-of-flight then is 8.7 ms (at an ambient temperature of 25° C.). If the distance x from the transducer to the hand is 0.5 m, the time-of-flight is 2.9 ms. If the required accuracy of control steps of the hand movement is 2 cm (time-of-flight steps of 0.12 ms), and the range of control is for instance 64 cm, there are 32 control steps, which allows for 5-bit control.
[0075] The control signal as shown in FIG. 3 is made by the movement of the hand 2 in a one-dimensional vertical direction in the ultrasonic beam 4 . At T 1 =1 s the hand 2 is outside the beam, the reference value is measured, and lamp control is disabled (stage A). At T 2 =2 s the hand 2 moves into the beam 4 and is held there for more than 1 second until at T 3 =3 s lamp control is enabled by the microcontroller (stage B). Then the hand 2 moves up between T 3 =3 s and T 5 =5 s, whereby for instance the intensity of the lamp 1 is increased by the microprocessor (stage C). At T 6 =6 s the hand is withdrawn from the beam 4 so that the reference value is measured, and lamp control is disabled thereby (stage D). An accidental movement of the hand 2 in the ultrasonic beam 4 as shown at T 7 =7 s does therefore not result in an accidental adjustment of the lamp properties (stage E). Hence, the lamp control is activated by holding an object in the ultrasonic beam 4 for more than 1 second.
[0076] The ultrasonic beam cone angle is important to provide reliable hand control. In FIG. 4 the beam radius at the reference position is r. The beam radius rh at the hand position must be high enough to have optimum control by hand. During control of a lamp property the average beam radius should be equal to approximately half the length of the average hand shape as shown in FIG. 5 . If the total control range is around X/2 (for a lamp/table application), the ultrasound beam angle at the minimum beam radius during control of the lamp property will be around Lh/2. For example: if Lh=150 mm and X=1.5 m, the ultrasound beam angle θ should be 11°. The relationship between the vertical distance X and the beam angle as function of the beam radius is shown in FIG. 6 . Lamp control will be possible if the hand 2 is in the narrow ultrasound cone 4 as shown in FIG. 7 . Reduction of a wide ultrasound beam 4 and an increase of sound pressure level (SPL) of an ultrasonic transducer 5 may be achieved by a horn 6 as shown in FIG. 8 .
[0077] FIG. 9 shows the calibration process of the sound pressure level (SPL) generated by the ultrasound transducer. In step A, when the lamp is switched on, the value for the representative of the sound pressure level amplitude (SPLampI T ) as transmitted by the transducer is zero and the value of the sound pressure level status (SPL OK) is zero. Said representative for SPLampI T may for instance be expressed in a voltage which is put on the transducer.
[0078] In step B the first calibration cycle is started by the processing means, by increasing the transmitted sound pressure level amplitude value by incremental increase value (gain) G. In step B the transducer sends an ultrasound pulse based on said SPLampI T value. In steps D and E the processor monitors during a maximum period of 20 ms if a signal is received that is greater than a predetermined threshold value. If no such signal is received after 20 ms, in step F a period of 100 ms is waited, and the loop is repeated as from step B.
[0079] If in step D it is determined that a signal SPLampI R is received that is greater than a predetermined threshold value, at least two extra smaller increases of SPLampI T may be made in order to ensure that the emitted amplitude has enough margin to compensate for instance for temperature changes. To that end, if in step G it is determined that SPL OK is not greater than 1, then in step H SPL OK is increased by 1, the value for the incremental increase is reduced to half the previous value, and after waiting 100 ms in step F the loop is repeated as from step B.
[0080] After these steps the final value for SPLampI T is established and stored in memory in step I. This value is then used during the remaining period that the lamp is on, i.e. the voltage represented by said value is put on the transducer during the light control process of the lamp as described above.
[0081] The above calibration process of the SPL does not necessarily take place on a fixed reference surface such as a table. It can also be applied while the user is holding his hand in the ultrasonic beam, preferably at the lowest point of control operation. Thereby the SPL can be set at a lower level than for instance would be the case if the fixed reference surface would be a floor. It is even possible to combine the SPL calibration process with the control movement of the hand, and dynamically calibrate the sound pressure level while the hand is moving in the ultrasonic beam.
[0082] The process of increasing the voltage put on the transducer during the transmission of ultrasonic pulses and measuring the voltage of the received reflected signals from the transducer, and increasing the SPL OK status until the threshold is exceeded is shown in FIG. 10 .
[0083] There are two important issues with respect to robustness of gesture light control based on ultrasound: acoustic issues like reflections, diffraction, fatal interference, extra noise adds to receiver, and user interface issues like unstable objects (as shown in FIG. 11A-11C ), changed (reference) objects (as shown in FIG. 12 ), and different objects at the same time, etcetera.
[0084] In FIG. 11A a hand 2 is shown, which accidentally moves horizontally through the ultrasonic beam 4 from T 1 to T 3 . In FIG. 11B a hand 2 is shown, which accidentally moves vertically through the ultrasonic beam 4 from T 1 to T 3 . In FIG. 11C a hand 2 is shown which moves into the ultrasonic beam 4 from T 1 to T 2 and is held stably in said beam until T 3 . It is desirable that the accidental movements as shown in FIGS. 11A and 11B do not incur any light control actions. The action as shown in FIG. 11C however is proposed to be a user command that enables light control thereafter, as explained above with reference to FIG. 3 .
[0085] In FIG. 12 a vase 7 is shown, which is put on the reference surface 3 (for instance a table) between T 1 and T 2 . Thereby the measured time-of-flight is shortened. On T 1 lamp control is disabled (stage A), and the shortened time-of-flight will result in enablement of the lamp control (stage B), as explained above with reference to FIG. 3 .
[0086] If however the vase 7 , is in the beam 4 for more than a predetermined period, for instance 1.5 seconds or longer, then it is assumed that a new reference object is placed in the beam (stage C). The measured value is then stored as the new reference value and control is disabled (stage D).
[0087] In FIG. 13 a basic algorithm for gesture light control is shown. If we the lamp is switched on (step A) and hardware is initialised (step B) the sound pressure level will be calibrated (step C) as described above with reference to FIG. 9 . The ultrasonic transceiver will be sent an acoustic signal to check if a (reference) object is present and to regulate the sound pressure of the acoustic echo signal to a minimum. If no signal is received after a predetermined period (step D), an error signal is generated and presented to the user (step E).
[0088] Then a reference calibration (step F) will be performed at a fixed obstacle like a table, a floor, etcetera and is based on the first received echo signal after sending a pulse to the transmitter. Other received echo signals shifted in time (compared with the first received echo) are signals based on reflection (as shown in FIG. 1 ). These signals are eliminated.
[0089] The reference calibration algorithm (step F) is further explained with reference to FIG. 14 . A pulse is sent (step G) and the time-of-flight from the source to the reference surface and back to the source is measured (step H) and stored as TOF I (step J). If no signal is received after a predetermined time-out period (for instance 3 seconds) (step K) after more than two attempts (step L), an error signal is generated and presented to the user (step M). Reproducibility of this measurement is checked by repeating the measurement for I=0 to I=19. A check is performed if the stored values for TOF I (apart from the two most extreme values) are within a predetermined threshold z (step O), otherwise the reference calibration is started again. Then the average reference value TOF REF is calculated (step P) and is stored as representative of the maximum allowable distance (step Q), but only if said TOF REF is larger then a predetermined minimum, otherwise an error signal is generated and presented to the user (step R). In this example said minimum is 32 times a predetermined minimum increment, so that at least 32 incremental distances of a hand movement can be measured and translated into control instructions. During gesture control no movement beyond the maximum distance represented by TOF REF is expected nor tolerated. The reference distance will also determine the control range.
[0090] After the reference calibration (step F) the system is set into a “wait-for-control-enable” state (step S), as shown in FIG. 15 . The sample frequency is reduced to 4 Hz (250 ms) (step V). The system will wait for an obstacle/object (e.g. a hand), by measuring TOF H (step T, shown in more detail in FIG. 16 ; Time_out=100 ms) and comparing said TOF H with the reference value (step U). As long as TOF H is greater than or equal to the reference value TOF REF it is assumed that no object is present in the beam and the system will repeat this cycle at the sample frequency.
[0091] If TOF H is smaller than the reference value TOF REF twenty measurements (for H=0 to 19) during 1 second are performed to check if the object is stable, by checking if the difference between TOF H and the previous measurement TOF H−1 is smaller than a predetermined threshold tx (for instance a value representing a distance of 2 cm) (step V). If this is the case the average of the measured TOF-s, TOFH (step W) is stored and the algorithm continues to the control enable step (step X) in FIG. 13 . During the control enable cycle the system checks if the object (hand) is still present in the beam (step X 3 in FIGS. 13 and 17 ) and if the object is making control gestures, i.e. by moving (step X 4 in FIGS. 13 and 17 ), as explained in more detail with reference to FIG. 17 below. Through the above-described algorithm the system will not react on short (<1 second) disturbances of the ultrasound beam cone during the wait-for-control-enable cycle. A continuous check if echo signals are received will be carried out at the reduced sample frequency.
[0092] By the proposed algorithms the control of light will be only possible when the hand movement fulfils a certain profile, as exemplified above with reference to FIG. 3 . Control is disabled when the hand is moved outside the ultrasound beam cone (step D in FIG. 3 ). Control is also disabled when the reference object is changed, as explained above with reference to FIG. 12 .
[0093] Now with reference to FIGS. 17 and 18 (wherein C and FC start with value 0) the enable-control algorithm (step X) is further explained. In order to give feedback to the user with respect to the fact that control is enabled, a visual signal is given, for example in this embodiment a green LED (G-LED) will be switched on (step X 1 ). The sample frequency is increased to 40 Hz.
[0094] Based on the determined TOF the control range will be automatically determined (step X 2 ), as illustrated in FIGS. 19 and 20 . Preferably the total number of steps Ns tot is chosen such that the sensitivity of the system, i.e. the length of a control step, is approximately 2 cm, which corresponds to a TOF of 0.116 ms (2*0.02 m/345 m/s). A preferred number of control steps of 32 is proposed, so that the control range of the hand is 64 cm, wherein the initial position of the hand is the centre of said range. However if the hand is closer to the source or the reference surface than 32 cm (minus a safety margin, reflected by TOFBS and TOFBR) obviously the control range cannot be 32 cm on either side of the hand, and the control range is shifted, for instance by locating the upper or lower limit of the control range (RangeMin or RangeMax) on the respective safety margin borders (TOFBR or TOFBS).
[0095] The time-of-flight (TOF C ) between the source and the hand is determined. Continuous checks are made to determine if the hand is still in the beam (step X 3 ) and if the hand is moving (step X 4 ). If the hand is not in the ultrasound beam anymore for a predetermined time, control will be disabled. If the hand is in the beam, but not moving for at least one second, it is checked if prior thereto light properties have been controlled (FC>0). If this is the case, the FC is reset to 0 and control is disabled. If this is not the case, the control mode is switched to controlling a different light property, indicated by FC being raised by 1, and the algorithm returns to TOF C determination loop.
[0096] If it is determined that the hand is moving (step X 4 ), and then it is checked if the TOF C is within the calculated range (step X 5 ). If TOF C is outside said range clipping takes place (step X 6 ), for instance by replacing TOF C with the nearest maximum value, as illustrated in FIG. 21 . The direction (step X 7 ) and the number of steps Ns act (step X 8 ) is calculated, which is used to translate the physical hand position into a digital position value for control purposes.
[0097] Ns act is calculated by dividing the difference in the measured TOF (TOF C −TOF C−1 ) by TOF. These values are translated to a drive signal sent to the LED drivers to control the light properties. The current value of FC determines which one of the light properties is controlled (step X 9 ). In this example there are only two properties to be controlled: “basic control” and “fine control”, but this can be easily extended. This control loop for controlling a light property is repeated until control is switched off, or until FC is raised so that a different light property is controlled.
[0098] Three different methods are proposed as examples for selecting the light properties to be controlled, based on a menu structure. In the first method the selection of the basic light controls will be based on the freezing of the object (i.e. hand 2 ) during for instance 1 second. The second method of selection of the basic controls is based on rotation of the hand. The third method of selection in menu control for basic light controls is based on the hand crossing the ultrasound beam in horizontal direction (assuming that the ultrasound beam extends in vertical direction).
[0099] With these methods the basic light controls can be selected in a sequential manner, as illustrated in FIG. 22 . This means that if a user first selects a light colour (from 1 s to 1.8 s), the control selection is moved on towards control of the colour temperature of the chosen colour 1 second later (at 2.8 s). Control of colour temperature is then also achieved by hand movement (from 2.8 s). The control range is chosen the same as used for the previous basic control.
[0100] FIGS. 23-28 shows as an example the different steps in a menu for three basic LED light controls. In FIG. 23 the colour is controlled by up-and-down movement of hand 2 . In FIG. 24 the hand 2 is frozen at specific desired colour for 1 second, so that said specific colour is chosen, and control selection is switched to colour temperature control in FIG. 25 . In FIG. 26 the hand 2 is frozen at a specific desired colour temperature again for 1 second, so that said specific colour temperature is chosen, and control selection is switched to intensity in FIG. 27 . In FIG. 28 hand 2 is frozen at a specific desired light intensity, so that said specific light intensity is chosen, and control is switched off.
[0101] Switching from one basic control to another one can also be achieved by making a hand rotation. Therefore a certain angle between hand and ultrasonic beam has to be made (see FIG. 29 ). If the angle between hand and ultrasound bean cone is 90 degrees the maximum echo signal will be received by the ultrasound transceiver. If the hand makes an angle of 45 degrees with the ultrasound beam cone (almost) no echo signal will be received by the transceiver, because the echo signal will be reflected by the hand to another position. A certain unique profile can be chosen for selecting one of the basic controls in a menu, for example as shown in FIG. 29 .
[0102] With this method the user can switch from one basic control to another one without the need to control each basic control. Stepping through the menu is done by another type of
[0103] Selection of a basic light control can also be achieved by (horizontal) hand movements crossing the ultrasound beam cone, as illustrated in FIG. 30 . The time-of-flight is measured with a high sample rate, and an alternating TOF signal (low-high-low, etcetera) is recognized as a unique profile, which can be chosen for selecting the basic controls in a menu.
[0104] In a light remote control system, before, during or after the user inputs light control instructions feedback or messages will be given to said user, comparable to TV applications where feedback is given via the display to the user during control of the basic functions like contrast, brightness, saturation, etcetera. For example if the light system does not receive the control signal, or the signal is too weak, a certain error messages to the user is desirable.
[0105] Depending of the used light control application like remote control, ultrasound or video based gesture light control, different feedback mechanisms are proposed.
[0106] In a menu controlled system changes have to be made visible for the user. Also when control is enabled feedback has to be given. If an error occurs also feedback has to be given to the user. Also different kinds of error messages can be given to the user or to a service environment for fast analyses and repair of the error.
[0107] The first proposed method for feedback to the user is messaging by light pulses, or flickering of light.
[0108] Eyes are very sensitive for light flicker until frequencies around 60 Hz. Flicker can be made by switching the light off and on again very fast. A alternative method to create light flicker is reducing light intensity for a very short moment in time and change it back to the original light intensity.
[0109] The second proposed method for feedback to the user is messaging by light colour changes or colour temperature changes. Different colours or colour temperature could give different messages to end-user. Also a combination of the first two methods can communicate extra information to the user.
[0110] The third proposed method is to make text feedback using a LED array lamp. By placing the LEDs in an array as shown in FIG. 31 , array text messages can be formed. Also icons can be formed. FIG. 31 shows an example of a message text “E 2 ”, which could be a certain error message. In this manner the LED lamp is used as a display to send different text messages to the user or service department during an error situation.
[0111] As shown in FIG. 32 , the text of the LED array can also be projected by a lens 8 on an object surface (reference 3 ) like a table, a wall or floor. In an ultrasound based gesture light control system as described above the distance between the lens 8 and the object (the focal length f) by the TOF measurement of the ultrasound sensor 5 (here shown built in the lens 8 ) can be used. With this information the focal length can be adjusted as function of the distance with the object (automatic focus). For example a stepper motor can perform the adjustment of the focal length. The text of the lamp array has to be mirrored if a lens is used.
[0112] In order to reduce the costs of the lamp to a minimum and to have the possibility to control all possible lighting parameters like colour, intensity, etcetera, the electronic circuit needed for carrying out the control functions is integrated in the lamp. The microprocessor used for gesture control is also integrated in the LED control microprocessor to reduce the cost even more. The integration of the ultrasound sensor in the lamp makes low cost, high volume production possible.
[0113] With reference to FIG. 33 , as explained above the micro-controller sends a pulse to the ultrasound transmitter of the ultrasound transceiver 5 . A digital pulse signal is generated by the control part 13 A of a micro-controller 13 , and converted by DA-converter 17 in said micro-controller 13 into an electric pulse. This pulse will be amplified by the amplifier 18 in the pre-processor 10 (shown in more detail in FIG. 34 ) to a value that can be used by the ultrasound transmitter part of the ultrasound transceiver 5 . Then the piezo-electric ultrasound transceiver 5 sends an acoustic signal (for instance at a frequency of 40 kHz). An object will reflect this acoustic signal. The pre-processor 10 will receive the reflected signal via the ultrasound transducer 5 . In order to reduce the influence of outside disturbances the signal is filtered by a 2nd order High-Pass filter 11 of for instance 20 kHz (=fc). After filtering the signal is amplified by amplifier 12 in the pre-processor 10 .
[0114] Microcontroller 13 comprises a comparator 14 , which creates a digital pulse signal from the electric signal received from the pre-processor 10 , which can be processed by the micro-controller 13 .
[0115] The micro-controller 13 further comprises a LED driver part 13 B, with a modulator 20 , which is connected to the LED driver 19 , and part of the ROM 15 and the RAM 16 , which is shared, with the control part 13 A of the micro-controller.
[0116] Such a micro-controller 13 , arranged to drive a LED, is well known in the art, but is further programmed to perform the control functions as described above. The micro-controller can be a simple processor, for instance of the 8051-family. The size of the ROM 15 can be as low as 2 kB and the size of the RAM 16 can be as low as 256 bytes.
[0117] FIG. 35 shows a lamp according to the invention comprising a housing with a standard incandescent lamp type fitting, ten LEDs 21 arranged in a circle, a transducer 5 in a horn 6 . All the electronic components like the micro-controller 13 , pre-processor 10 and LED driver 19 are built-in in the housing 23 . Thereby a very compact lighting system is obtained, which requires no further external accessories to be operated and controlled.
[0118] Although the invention is described herein by way of preferred embodiments as example, the man skilled in the art will appreciate that many modifications and variations are possible within the scope of the invention.
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A lighting system comprising a lamp arranged to transform electricity into a light beam having different properties; a light control means arranged to adjust said light beam properties; an ultrasonic transmitter arranged to transmit ultrasonic signals; an ultrasonic receiver arranged to receive reflected ultrasonic signals; and a processing means arranged to derive a time-of-flight signal representing the time differences between said transmitted and received ultrasonic signals and to send control signals to said light control means in dependence of said time-of-flight signal. The processing means performs a reference calibration step: the time-of-flight is repeatedly measured a multitude of times, and calculates the average of said measured time-of-flight values and stores the average in memory means as a reference time-of-flight value if said deviation of the majority of the measured time-of-flight values of said multitude of measurements is lower than a predetermined threshold.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention pertains generally to eddy current data obtained from non-destructive examination of a component and more particularly, to a method of combining eddy current data obtained at two different scanning frequencies.
[0003] 2. Description of the Prior Art
[0004] Nondestructive examination of components is carried out in a number of fields and is particularly important in the periodic inspection of steam generator tubing that form part of the primary circuit of a pressurized water reactor nuclear steam supply system. The integrity of the steam generator tubing in the primary circuit of a pressurized water nuclear reactor steam supply system is essential to assure that radioactive coolant from the reactor does not contaminate the secondary side circuit in which it is in heat transfer relationship to create steam to drive a turbine which in turn drives a generator to create electricity. A hot leg of the nuclear reactor primary coolant circuit is connected to one side of a hemispherical plenum on the underside of the steam generator. The hemispherical plenum is divided into two substantially equal parts and bounded on its upper side by a tube sheet. Heat exchanger tubes extend from one side of the hemispherical plenum through the tube sheet into the secondary side in a U-shaped design that terminates through the tube sheet to the other side of the hemispherical plenum. The other side of the hemispherical plenum is connected to a cold leg of the nuclear reactor primary coolant circuit. There are hundreds of tubes within the steam generator communicating between the hot side and the cold side of the plenum. To ensure the integrity of the tubes, periodically, during reactor outages, the plenum is accessed through manways and the tubes inspected. Eddy current probes are inserted into the tubes and the tube position and data read by the eddy current detectors are recorded to identify any flaws that may have developed in the tubes during the preceding service period between inspections. The eddy current data takes the form of signal patterns, which require a great deal of experience to interpret to identify the existence, type and extent of any flaws that may be present in the tubing. If flaws are detected that exceed a given criteria, the corresponding tubing is plugged and thus taken out of service to reduce the likelihood of failure during the forthcoming reactor operating cycle.
[0005] Obtaining eddy current data representative of the various kinds of flaws that are likely to be encountered under field conditions, among a background of scattering data and other noise encountered in the field, to train data analysts and test inspection techniques, is extremely difficult and expensive. However, such training is essential to being able to properly interpret eddy current data. Similarly, the testing of inspection techniques is necessary to understand the probability of detecting different types of flaws and the affect the sizing of a flaw has on the various discontinuity responses.
[0006] Accordingly, a need exists to acquire eddy current data representative of the detection of a number of different flaws that is suitable for training and qualifying analysts and testing inspection techniques. Desirably, such data should have substantially the same background, scatter and other noise as is encountered in the field.
[0007] U.S. Pat. No. 6,823,269 addresses this need by teaching a method for synthesizing eddy current data for this purpose. The steps of the method involve creating a specimen that simulates the component undergoing nondestructive examination with preselected flaws of interest. The specimen is then monitored by an eddy current probe to create a set of eddy current data representative of the flaws detected in the specimen. At least some of the eddy current data collected at a field site is combined with at least some of the eddy current data collected from the specimen to establish a combined data train that reflects the eddy current response to the selected flaws in a background representative of data collected at the field site. Preferably, the eddy current probes used to collect data at the field site and at the specimen are the same type and are operated at the same inspection frequencies and data sampling rates. Furthermore, the patent teaches that it is desirable that the field and specimen data sets are calibrated separately to substantially the same standard so that the signal level and orientation for a given flaw correspond. However, the patent reference recognizes in the real world there will be differences in monitoring conditions between the field data set and the data set obtained from the specimen and states that if there are differences in the inspection conditions, mathematical models can be used to interpolate one or the other of the responses if coil size or inspection frequencies are not identical.
[0008] Initially, simple linear combinations of the inspection results from two frequencies were used in an attempt to infer the response at an intermediate frequency. While this produces a result that approximates the desired response it was found that it lacked many of the subtleties present in the original data. It was determined that the shortcoming of the approach was a consequence of the frequency dependent field spread associated with the eddy current coil. This leads to a response being in the lower frequency data at locations where there was none at the higher frequency. A simple combination of the two responses is satisfactory where the two responses overlap but is inadequate where they do not.
[0009] Accordingly, a new method is desired that would enable the data union method to be employed with two or more data sets obtained at different frequencies.
[0010] Furthermore, such a method is desired that would enable the combination of different data sets obtained at different frequencies without the loss of any of the information in the original data sets.
SUMMARY OF THE INVENTION
[0011] These and other objects are achieved by the method of this invention for interpolating or extrapolating eddy current inspection data at a desired frequency. The method acquires a first set of eddy current inspection data at a first frequency, a second set of eddy current inspection data at a second frequency and a reference set of eddy current inspection data at the first frequency, the second frequency and at the desired frequency. The method then infers the eddy current inspection data at the desired frequency based upon the first set, the second set and the reference set of eddy current inspection data. In most instances, the desired frequency will be one or the other of the first frequency or the second frequency. All three or more data sets should be obtained from the same type of probe and under substantially similar inspection conditions. The remaining two or more data sets should be rotated and scaled to the data set obtained at the desired frequency before interpolation or extrapolation. Desirably, the reference data set should include a number of responses to different discontinuities and structures that are likely to be encountered in a field inspection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Further understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:
[0013] FIG. 1 is a perspective view of a portion of a steam generator tube in which an eddy current probe is about to be inserted;
[0014] FIG. 2 is a computer screen image of a comparison of 200 kHz response of the calibration standard to that interpolated from 400 and 100 kHz response;
[0015] FIG. 3 is a computer screen image showing a comparison of a 380 kHz response of the calibration standard to that interpolated from 760 and 130 kHz response;
[0016] FIG. 4 is a computer screen image of a comparison of 760 kHz response of the calibration standard to that extrapolated from 380 and 130 kHz response.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] In the inspection of steam generator tubes ( 10 ) by nondestructive eddy current probes ( 11 ) (as figuratively shown in FIG. 1 ) eddy current data is routinely acquired for a number of different inspection frequencies and from a number of different eddy current coils. In modern instrumentation all timing and data acquisition are conducted digitally so that all eddy current data are assumed to be in digital format, although the described process could be accomplished in analog also. At each inspection interval data are acquired (often referred to as a time slice or just slice) for each of the coils at each of the frequencies in a prescribed order. The data are then stored in the prescribed order in an array. At the next interval the process is repeated such that, typically, each interval of data corresponds to some relative motion of the coils over the part under inspection. For coils pulled though a tube ( 10 ), e.g., a bobbin coil ( 11 ), the response for each coil and frequency are two one dimensional arrays with adjacent elements, corresponding to different coil positions along the axis of the tube. For coils that raster over a surface or are rotated inside a tube the resulting data are also in a time sequence, however, the response resulting from a particular location on the part being tested now occurs during a sequence of slices separated by multiple intervals determined by the scanning pattern.
[0018] The algorithm of this invention incorporates a set of coefficients that are multiplied by the responses obtained for the desired coil at the measurement frequencies and for inspection intervals associated with the location of interest within the overall data set. For data obtained from a bobbin coil this corresponds to intervals adjacent to one of interest. For raster data the process includes data from both adjacent intervals and also those intervals that are adjacent spatially within the coil motion. For simplicity what follows is a description of the algorithm as applied to bobbin coil data.
[0019] To begin, assume that there are two sets of inspection data that were acquired with similar probes and similar inspection conditions such that the only difference is that the set of inspection frequencies are different. Further, both data sets have been appropriately rotated and scaled to allow for their data to be appropriately combined. Again, for simplicity, it is assumed that there is only one inspection frequency that is different between the two data sets i.e. Set A uses frequencies f 1 , f a , and f 3 and Set B uses frequencies f 1 , f b and f 3 where f 1 >f a and f b >f 3 . The desire is to combine data Set A with data Set B requiring that data at the response at f b be interpolated from f 1 , f a and f 3 . For each data interval (t) the relationship between the measurement at f b and the measurement at f 1 , f a and f 3 can be written:
[0000] C *( A )=( B )
[0000] Where C is the matrix of coefficients
C 11 C 12 C 13 . . . C 1m
C 21 C 22 C 23 . . . C 2m
[0020] and A is a vector of x(f) and y(f) components at each of the frequencies f 1 , f a and f 3 for the various data intervals t−n*d, t−(n−)*d . . . t . . . t+(n−1)*d, t+n*d where n is the number of slices to include before and after t and d is the distance between slices and m is the largest dimension of the coefficient matrix and is related to n and the number of frequencies used in the interpolation/extrapolation.
[0000] A =( x ( f 1 ) t−n*d . . . x ( f 1 ) t . . . x ( f 1 ) t+n*d , y ( f 1 ) t−n*d . . . y ( f 1 ) t . . . y ( f 1 ) t+n*d , x ( f a ) t−n*d . . . x ( f a ) t+nd , y ( f 3 ) t−n*d . . . y ( f 3 ) t+n*d ) T
[0021] So that m=2*number of frequencies*(2n+1)=6*(2*n+1)
[0000] And B =( x ( f b ) t ,y ( f b ) t ) T
[0022] After B is calculated for each data interval the entire set is inserted in place of the portion of data Set A that contains the inspection data obtained at inspection frequency f a . The resulting data set (Set A′) can then be combined with data Set B as per the Data Union process described in U.S. Pat. No. 6,823,269.
[0023] To implement this procedure, however, the coefficient matrix must be calculated. This requires that a third set of data (Set R) exists or is created that includes inspection results from all of the inspection frequencies that are to be included in the interpolation/extrapolation process. For the example this means that the data Set R contain data obtained at the inspection frequencies f 1 , f a , f b and f 3 . Again data Set R must be acquired in a manner consistent with data Sets A and B and rotated and scaled appropriately. Within Set R responses for a number of discontinuities and structures must be present, so that it is most appropriately the data from a calibration tube. The process to calculate the coefficient matrix C is as follows.
[0024] Vectors A and B are constructed from the appropriate subset of data Set R. For each interval the following is constructed
[0000] λ=( C *( A )− B )
[0025] C is the set of coefficients that minimizes (λ) 2 for the data intervals containing the responses of interest. Once matrix C is calculated it can be utilized to interpolate inspection frequencies for any data set that has been obtained in a fashion similar to Set R. This includes data obtained from different tubing sizes provided that the inspection frequencies have been appropriately scaled.
[0026] To verify the process consider the following example using a data set for ⅞ inch diameter tubing having inspection frequencies 400, 200 and 100 kHz. The data from 400 and 100 kHz will be used to interpolate the 200 kHz data. In this case the 200 Hz data was used to calculate C and the resulting interpolation compared directly to the actual data. FIG. 2 shows the response of various simulations associated with the calibration tube both interpolated and measured. The difference in the two responses is minimal. More specifically FIG. 2 shows a Comparison of a 200 kHz response of the calibration standard to that interpolated from 400 and 100 kHz. The left image shows the responses of the tube support simulation and 100% discontinuity while the right image shows the responses of the 60%, 40% and 20% discontinuities. The lower images show the 200 kHz responses, and the upper images show the interpolated responses. The extent of the discontinuity is determined by the phase. For example, the left discontinuity reflected signal is deeper than the right reflected signal.
[0027] As another example the C matrix calculated for the ⅞ inch diameter tubing was applied to the data collected for a ⅝ inch diameter tube. Since the wall thickness is less for the small diameter tube the inspection frequencies are adjusted to compensate resulting in the use of 760, 380 and 130 kHz. FIG. 3 shows a comparison of the interpolated 380 kHz response with that measured. The lower images are the measured responses, and the upper images are the interpolated responses. Again the differences in the responses are minimal. More specifically FIG. 3 shows a Comparison of a 380 kHz response of the calibration standard to that interpolated from 760 and 130 kHz using the coefficient calculated for use with the ⅞ inch diameter tube. The left image shows the responses of the tube support simulation while the right image shows the responses of the 100%, 60%, 40% and 20% discontinuities.
[0028] An additional functionality for which the process is applicable is to extrapolate the response to a frequency range outside of that bounded by the examination frequencies. In this scenario f b could be either greater than f 1 or less than f 3 in the above examples. As an example of this capability, the ⅝ inch diameter tubing data were used. In this case the inspection data obtained at 380 and 130 kHz was used to extrapolate the response for 760 kHz. FIG. 4 shows a comparison of the extrapolated 760 kHz response with that measured. The lower images are the measured responses, and the upper images are the extrapolated responses. Again the differences in the responses are minimal. More specifically FIG. 4 shows a Comparison of a 760 kHz response of the calibration standard to that extrapolated from 380 and 130 kHz. The left image shows the responses of the tube support simulation while the right image shows the responses of the 100%, 60%, 40% and 20% discontinuities.
[0029] While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular embodiments disclosed are meant to be illustrative only and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalence thereof.
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A method of synthesizing nondestructive examination data of a component that combines data sets acquired at least two different frequencies. At least one of the data sets is interpolated or extrapolated to the equivalent of data acquired at one of the other frequencies employing a third, reference set of eddy current inspection data that is acquired at each of the inspection frequencies being combined.
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FIELD AND BACKGROUND OF THE INVENTION
This invention relates to a thickness gauge for non-metallic materials in the form of foil, film, tape or the like.
The thickness of such materials can be measured indirectly by measuring the absorption of a radiation source, or directly by measuring and comparing the distance of the two faces or surfaces of the film. Gauges which directly measure the distance of the film surfaces can perform the measurement either with or without contact.
Document GB 2,217,835A describes a non-contact thickness gauge for measuring the thickness of foil, film and tape made of non-metallic materials.
In particular, it illustrates the combination of a first optical sensor which measures the distance to the upper surface of the film, and a second inductive sensor which measures the distance to a metal reference surface.
The inductive sensor is hollow to allow the housing of the optical sensor, and the two sensors are installed coaxially so that they perform their measurements along the same measuring axis.
While the measurements of the first sensor are performed directly on the measuring axis, those of the second sensor naturally take place on an area surrounding that measuring axis (typically an annulus), so that in practice the second sensor estimates the distance to the metal reference surface along that measuring axis.
In a first disclosed embodiment, the metal reference surface comes into contact with the lower surface of the film.
Since the film moves, the said reference surface is preferably a roller in order to minimise friction.
GB2217835A also describes a second construction in which the metal reference surface is positioned at a distance away from the lower surface of the film, such distance being known as a result of the use of a third, optical sensor.
The above-mentioned thickness gauge presents some drawbacks, however.
Depending on the composition of the material being examined and its surface characteristics, the ratio between the regular reflection factor and the diffuse reflection factor can vary considerably, as can the diffusion indicating curve.
The optical sensors used in thickness gauges designed in accordance with the known technique must therefore be specially constructed on the basis of the optical characteristics of the materials to be measured.
Equally, the optical characteristics of the materials to be measured often present intentional or unintentional dissimilarities which can prejudice the regulation system of the sensor.
In this respect, it should be noted that the speed of the material to be measured relative to the thickness gauge can reach values of around 10 m/sec. By contrast the time constant of the regulator of an optical sensor is measured in tenths of a second, with the result that sudden variations in the optical characteristics of the material overload the regulation circuit of the optical sensor. This makes the measurements performed unreliable because of the adjustment time required by the optical sensor regulator (typically a few tenths of a second). Moreover, the large size of currently known optical sensors means that inductive sensors with a very large diameter have to be used, thus reducing the reliability of the measurements taken.
In fact, the larger the size of the annulus on which the measurement of the inductive sensor is performed, the less precise is the estimated distance of the metal reference surface along the measuring axis.
It should be noted that optical distance sensors have a maximum accuracy of around ±10 μm, which is not always satisfactory, especially when the average thickness of materials measured is under 1 mm.
In general the non contact thickness gauges currently known for non metallic materials present reliability problems.
SUMMARY OF THE INVENTION
In the light of these drawbacks, this invention offers an improved thickness gauge for non-metallic materials in the form of film, foil, tape and the like.
According to one aspect of this invention, a gauge for measuring the thickness of foil, film, tape and similar materials has been designed.
The invention also relates to a method of measuring the thickness of a foil, film or tape.
Finally a method for calibrating the gauge is provided.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described below by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a front elevation in partial cross-section of a thickness gauge in accordance with one embodiment of the invention;
FIG. 2 is a side elevation in partial cross-section of the device shown in FIG. 1;
FIG. 3 is the same view as in FIG. 2, showing the thickness gauge mechanically de-activated;
FIG. 4 is a cross-sectional view of a detail of the thickness gauge in accordance with another embodiment of the invention;
FIG. 4a is an enlarged cross section view similar to FIG. 4.
FIG. 5 is the same view as in FIG. 4, showing an alternative embodiment of the invention;
FIG. 6 is a diagram showing the output curves of a backscattering fluid sensor used with in the gauge of the invention;
FIG. 7 is a diagram showing the curve of a pressure differential amplifier used in an embodiment of the gauge of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the annexed drawings, reference number 1 (see FIGS. 4 and 5) indicates the thickness gauge. The thickness gauge 1 for first non-contact measuring means 3, designed to measure the distance to a first or upper face 2 of a non-metallic material 4 present in the form of film, foil, tape or on the flattened form, and second non-contact measuring means 5, designed to measure the distance to an upper metal reference surface 6.
First and second measuring means 3 and 5 are both positioned above the upper face 2 of material 4, and function coaxially so that the measurements relate to the same measuring axis 8.
In accordance with a first embodiment, as seen in FIG. 4, film 4 moves in contact with metal reference surface 6, ie. metal reference surface 6 coincides with the second or lower face 18 of film 4.
To reduce friction between film 4 and the reference surface 6, surface 6 can be a rotating surface.
A characteristic of the thickness gauge 1 is that first means 3 consist of a backscattering fluid sensor.
The purpose of a backscattering fluid sensor is to detect the pressure induced inside a detecting duct 35 due to an air flow coming from the outlet 36 and reflected from the surface 2 to be measured.
In fact, the pressure induced in the detecting duct 35 is a function of the distance between the outlet duct 36 and the surface to be measured.
According to a preferred embodiment, the air flow coming from the outlet duct 36 has a pressure of about 250 mBAR, while the pressure induced in the detecting duct 35 can be up to 70 mBAR.
Fluid sensors of this type, normally used to detect the presence of objects, are known, and are therefore not further described.
The use of backscattering fluid sensors allows the construction of a gauge designed to measure the distance to the upper surface 2 of material 4 which is unaffected by the optical characteristics of material 4.
Backscattering fluid sensors present very low radial dimensions which are smaller than those of an optical sensor (approximately 5 mm in diameter). This allows the use of second measuring systems 5 with smaller radial dimensions than those normally used, and which therefore provide more precise measurements.
Backscattering fluid sensors also present a higher level of accuracy than optical sensors, typically around 1.5 mm/mbar.
It should be noted that the backscattering fluid sensor presents a relatively large measurement spot (typically a circle of about 5 mm in diameter). This area is considerably larger than the spot a laser distance gauge measures (typically an ellipse of about 0.3 mm×1 mm).
This characteristic can be advantageously used when the sheet 4 presents surface profile that is extremely irregular (e.g. in the case of non wowen materials) as the measurement obtained represents an average value which is after all the most important information.
Typically, when materials 4 of this type are measured immediately following their exit from a production line, their temperature is often much higher than ambient temperature.
This heat emission can affect the permeability of the inductance in inductive sensor 5, thus producing measuring errors.
For this purpose, a preferred embodiment includes means 7, designed to maintain inductive sensor 5 at a constant temperature.
In accordance with this embodiment, the means 7 has an electrical resistor controlled by an electronic temperature regulation device.
In an alternative embodiment, the means 7 is a thermistor.
The reliability of the readings of first means 3 depends (inter alia) on the quality of the power source.
Any variations in input pressure, even of very short duration and relatively modest value, can make the readings of fluid reference sensor 3 unreliable.
For these reasons, means 9, designed to differentiate between the part of the global signal emitted by first means 3 which is due to variations in the profile of surface 2, and the part due to disturbances in the power source of first means 3, can be installed.
In one embodiment, the means 9 comprises a second backscattering fluid sensor or fluid reference sensor 9 (FIG. 2), powered by the same source as first backscattering fluid sensor 3, which measures a constant preset distance, e.g. a distance equal (or roughly equal) to the mean value of the measuring range in which first fluid sensor 3 operates.
As reference sensor 9 measures a constant distance, any variation detected by it is obviously attributable to disturbances in the power source.
If the difference between the signals of sensor 3 and reference sensor 9 is calculated, e.g. by means of a pressure differential amplifier (FIG. 7) a signal practically free of power source is obtained until the signals are substantially the same value, that is until the error components have approximately the same values. According to a different embodiment, means 9 comprises two reference backscattering fluid sensors powered by the same source powering the backscattering fluid sensor 3.
In this case, the two reference sensors 9 measure two distinct constant values, for example two intermediate distances in the sensor measuring range.
Again since the distances measured by said two reference sensors 9 are constant, any variation detected by them is obviously attributable to disturbances in the power source.
A primary advantage to using two reference sensor (9) is that it is possible to achieve a good error suppression through all the measuring range.
While an inductive sensor presents a relatively wide measuring range (in practice from approx. 0 to 8 mm), backscattering fluid sensors present a far narrower measuring range (in practice from approx. 0.1 to 1 mm) (FIG. 6 line with little circles).
In order to increase the range of use of the gauge of the invention up to the limits allowed by inductive sensor 5, fluid sensor 3 can be made to move along measuring axis 8.
In one embodiment, sensors 3 and 5 are both mobile, and for this purpose are both coupled to a slide 10 which runs on straight tracks 21 (shown in FIG. 3), along measuring axis 8.
Slide 10 can be driven by suitable motor systems 20, such as a direct-current motor or a step motor, which transmits motion to the slide 10 via a suitable mechanical drive such as a recirculating-ball screw.
The possibility of adjusting the position of first and second means 3 and 5, allows the use of the gauge in object with a wide range of thicknesses.
A position detector or transducer 11 is provided for knowing the position of gauge 1.
According to the preferred embodiment, the presence of the means for moving the first and second measuring means 3 and 5 can be suitably used for performing the calibration of sensor 3 and 5 even when they are fitted on the machine.
In other words the sensor 3 and 5 are moved along the measurement axis 8 and their measurements are compared with the measurement of detector 11.
The measuring surface can be, for example, the metal reference surface 6.
It should be noted that the calibration method does not require means for moving the measured surface.
Since the precision of the calibration thus effected depends primarily on the precision of detector or transducer 11, it is necessary to select the said detector or transducer 11 with particular care.
In accordance with a preferred form of construction, transducer 11, is an absolute position transducer, such as the type comprising an electric transformer with axially mobile core which supplies output voltage proportional to the position of the core. These transducers are commonly known as LVDT's (Linear Variable-Differential Transformers).
In order to eliminate the presence of moving mechanical parts which can be a source of malfunctions in the long run, an optical device can be used to make detector 11.
According to an alternative form of construction, transducer 11 can be an incremental position transducer, such as an electronic revolution counter (also known as an encoder) which counts the revolutions of motor 20.
In this case, the current vertical position of thickness gauge 1 is the algebraic sum of the movements previously performed.
It is obviously possible to use any other position transducer which provides an acceptable degree of precision.
In accordance with the annexed drawings, thickness gauge 1 oscillates around an axis 23 which is basically parallel to the plane of the material to be measured 4, and perpendicular to the direction of movement of material 4.
This latter system is preferable, as it enables thickness gauge 1 to be retracted rapidly from material 4 in case of slipping or contact between material 4 and gauge 1. This prevents possible damage to gauge 1. For this purpose, thickness gauge 1 can be connected to slide 10 via a first hinge 13, and to a linear actuator 15 via a second hinge (not shown).
In a preferred form of use, thickness gauge 1 is immobile along axis 8 during measurement of the material.
If the material presents a thickness profile with high variations, basically of the same magnitude as the measuring range of fluid sensor 3, it is preferable (and may even be necessary) for thickness gauge 1 to move in the direction of axis 8, continually compensating for variations in the thickness of the material, so that the distance of gauge 1 from upper surface 2 of the material remains costant.
For this purpose, a suitable electronic circuit of known type is installed to compensate for variations in distance between thickness gauge 1 and upper surface 2 of material 4. This circuit detects the variation in distance (or error) between thickness gauge 1 and upper surface 2 of material 4 at first preset intervals, and controls electronic motor 20 at second preset intervals to compensate for variations in distance between gauge 1 and upper surface 2.
The position regulation of thickness gauge 1 can be the proportional (P), proportional-plus-derivative (PD) or proportional-plus-derivative-plus-integral (PID) type.
FIG. 5 shows an alternative form of construction of the invention which is preferable when, in view of the low flexibility or adherence of material 4, lower surface 18 is not in constant contact with metal reference surface 6.
In this case, film 4 is maintained at a distance from reference surface 6, and third non-contact measuring systems 25, integral with the said reference surface 6, are installed to measure the distance between lower surface 18 and reference surface 6.
For the reasons explained above, the said third systems 25 are constituted by a backscattering fluid sensor.
In another embodiment, metal reference surface 6 and third sensor 25 are designed to move along measuring axis 8, driven by motor systems for example, like the motor systems used to move sensor 3 and 5.
A second position transducer or detector could also be installed (not shown) associated with the said third sensor 25.
The measurements taken by fluid sensor 25 can be corrected by comparing them with the measurements taken by one or more fluid reference sensors as already explained.
For calibrating the gauge 1 a device (not shown) for allocating a reference metallic surface in a known position along the measurement axis 8 could be provided.
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The invention relates to a thickness gauge (1) for non metallic materials (4) in the form of foil, film, tape or the like which comprises first non contact measuring means (3), designed to measure the distance of the faced material surface, and second non contact measuring means (5), designed to measure the distance of a metal reference surface (6), said first and second measuring means (3, 5) being installed on one side of a space for receiving the material (4) and operating in two coaxial spatial regions, so that their measurements refer to a same measuring axis (8), wherein the first non contact measuring means (3) is a backscattering fluid sensor.
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PRIORITY CLAIM
The present application claims priority on European Patent Application 03254300.1 filed Jul. 7, 2003.
1. Field of the Invention
The present invention relates to a method of expanding a tubular element having a first portion to be expanded to a first inner diameter and a second portion to be expanded to a second inner diameter larger than the first inner diameter.
2. Background of the Invention
Expandable tubular elements find increased application in the industry of wellbore construction, for example, in applications whereby the tubular element, after installation in the wellbore, is radially expanded to form a wellbore casing or liner. Typically the wellbore is drilled in sections, whereby after drilling each wellbore section a casing or liner is lowered in unexpanded state into the newly drilled wellbore section and subsequently radially expanded. Optionally the expanded casing/liner can be cemented in the wellbore by pumping a layer of cement between the casing/liner either before or after the expansion process.
Generally it will be required that subsequent casing or liner sections are interconnected in a manner that a fluid tight seal is obtained at the interconnection. This can be achieved, for example, by creating an overlap between subsequent sections of casing or liners such that an upper end portion of a lower casing section extends into a lower end portion of an upper casing section, either with or without a sleeve of deformable material there-between. Such overlap requires that the end portion of the tubular element into which the other tubular element extends, is expanded to a relatively large diameter. However, no reliable expansion method for achieving such result is available.
SUMMARY OF THE INVENTION
The present inventions include a method of expanding a tubular element having a first portion to be expanded to a first inner diameter and a second portion to be expanded to a second inner diameter larger than the first inner diameter, the method comprising:
a) arranging an expandable sleeve of selected wall thickness in said second tubular element portion; b) positioning an expander in the tubular element; c) operating the expander so as to expand said first tubular element portion to the first inner diameter, and operating the expander so as to expand the sleeve to an inner diameter substantially equal to the second inner diameter minus double the wall thickness of the sleeve; and d) retrieving the sleeve from the tubular element.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained hereinafter in more detail by way of example with reference to the accompanying drawings in which:
FIG. 1A schematically shows a side view of an expander when in retracted mode, used in an embodiment of the method of the invention;
FIG. 1B schematically shows the expander of FIG. 1A when in expanded mode;
FIG. 1C schematically shows the expander of FIG. 1A in longitudinal section;
FIG. 2 schematically shows a first step in expansion of a tubular element;
FIG. 3A schematically shows a side view of an expandable sleeve for use in the embodiment of the method of the invention;
FIG. 3B schematically shows a side view of the sleeve of FIG. 3A after radial expansion thereof;
FIGS. 4-6 schematically show a sequence of steps in expansion of the tubular element of FIG. 2 ; and
FIGS. 7A-B schematically show a retrieval tool positioned in the tubular element of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
In the drawings, like reference numerals relate to like components.
Referring to FIGS. 1A-C there is shown an expander 1 including a steel tubular expander body 2 having a front cylindrical part 2 a , a rear cylindrical part 2 b , and a tapering part 2 c arranged between the cylindrical parts 2 a , 2 b . A plurality of narrow longitudinal slots 6 are provided in the expander body 2 , which slots are regularly spaced along the circumference of the expander body 2 . Each slot 6 extends radially through the wall of tubular expander body 2 , and has opposite ends 7 , 8 located at some distance from the respective ends of the expander body 2 . The slots 6 define a plurality of longitudinal body segments 10 spaced along the circumference of the expander body 2 , whereby each body segment 10 extends between a pair of adjacent slots 6 (and vice versa). By virtue of their elongate shape and elastic properties, the body segments 10 will elastically deform by bending radially outward upon application of a suitable radial load to the body segments 10 . Thus the expander 1 is expandable from a radially retracted mode ( FIG. 1A ) whereby each body segment 10 is in its rest position, to a radially expanded mode ( FIG. 1B ) whereby each body segment 10 is in its radially outward bent position upon application of said radial load to the body segment 10 .
The expander further includes cylindrical end closures 12 , 14 arranged to close the respective ends of the expander body 2 , each end closure 12 , 14 being fixedly connected to the expander body 2 , for example by suitable bolts (not shown). End closure 12 is provided with a through-opening 15 .
An inflatable member in the form of elastomeric bladder 16 is arranged within the tubular expander body 2 . The bladder 16 has a cylindrical wall 18 resting against the inner surface of the tubular expander body 2 , and opposite end walls 20 , 22 resting against the respective end closures 12 , 14 , thereby defining a fluid chamber 23 formed within the bladder 16 . The end wall 20 is sealed to the end closure 12 and has a through-opening aligned with, and in fluid communication with, through-opening 15 of end closure 12 . A fluid conduit 26 is at one end thereof in fluid communication with the fluid chamber 23 via through-opening 15 . The fluid conduit 26 is at the other end thereof in fluid communication with a fluid control system (not shown) for controlling inflow of fluid to, and outflow of fluid from, the fluid chamber 23 .
Reference is further made to FIG. 2 showing the expander 1 arranged at the lower end 30 of a tubular casing 32 which extends into a wellbore 34 formed in an earth formation 35 . The expander 1 is suspended from surface by a conduit 26 . An expandable tubular sleeve 36 is arranged in a lower portion 38 of the casing 32 and temporarily fixed to the lower end 30 of the casing 32 by tack-welds 39 which should be strong enough to carry the weight of the sleeve 36 and to allow initial expansion of the sleeve 36 and lower casing portion 38 . Hereinafter the lower casing portion 38 is referred to as the bell portion 38 of the casing, and the remainder of the casing 32 is referred to as the remainder casing portion 41 . The front cylindrical part 2 a of expander 1 extends into the sleeve 36 .
The sleeve 36 is shown in more detail in FIGS. 3A and 3B , whereby FIG. 3A shows the sleeve 36 before radial expansion thereof, and FIG. 3B shows the sleeve 36 after radial expansion thereof. The wall of the sleeve 36 is provided with a plurality of through-openings in the form of slots 40 extending in axial direction. The slots 40 are arranged in rows of axially aligned slots, whereby adjacent rows are arranged staggered relative to each other so as to form a plurality of axially overlapping slots 40 . Each slot 40 is at each end thereof provided with a circular hole 42 . Plastic hinges 43 are formed by the wall portions of the sleeve 36 between each slot 40 and the respective adjacent holes 42 . In FIG. 3A the width of each plastic hinge 43 is indicated by symbol H.
The resistance to bending of the hinges 43 is governed by their wall thickness and width H.
In FIG. 4 , the expander 1 is located in the sleeve 36 whereby part of the sleeve 36 and part of the casing 32 have been radially expanded.
In FIG. 5 , the expander 1 is located upwardly from the bell portion 38 whereby the sleeve 36 , the bell portion 38 and part of the remainder casing portion 41 have been radially expanded.
In FIG. 6 , the expander 1 is located further upwardly from the bell portion 38 whereby the sleeve 36 , the bell portion 38 and a further part of the remainder casing portion 41 have been radially expanded.
Referring to FIG. 7A there is shown a retrieval tool 46 suspended from surface on a running string 48 extending into the casing 32 . The retrieval tool 46 is provided with a number of radially extending spring-loaded pins 50 biased into corresponding openings 52 formed in the wall of the sleeve 36 so as to latch the retrieval tool 46 to the sleeve 36 .
Referring to FIG. 7B there is shown the retrieval tool 46 latched to the sleeve 36 whereby the sleeve has been pulled upwardly a short distance through the casing 32 .
During normal operation, the casing 32 is lowered into the wellbore 34 whereby the sleeve 34 and the expander 1 are arranged relative the casing. 32 in the position shown in FIG. 2 whereby a moderate pulling force is exerted from surface to the expander 1 via conduit 26 . Subsequently the casing 32 is radially expanded in a plurality of expansion cycles whereby each cycle includes a first stage and a second stage, as explained below.
In the first stage of the expansion cycle the fluid control system is operated to pump pressurised fluid, for example drilling fluid, via the conduit 26 into the fluid chamber 23 of the bladder 16 . As a result the bladder 16 is inflated and thereby exerts a radially outward pressure against the body segments 10 which thereby. become elastically deformed by radially outward bending.
The volume of fluid pumped into the bladder 16 is selected such that any deformation of the body segment 10 remains within the elastic domain.
In order to promote uniform outward bending of the segments 10 , the front part 2 a of the expander body 2 is optionally provided with a ring or a sleeve (not shown) which limits outward bending of the segments 10 .
Thus the body segments 10 revert to their initial positions after release of the fluid pressure in the bladder 16 . Thus the expander 1 is expanded upon pumping of fluid into the bladder 16 from the radially retracted mode to the radially expanded mode thereof. As a result a short initial section of the casing 32 becomes plastically expanded.
In the second stage of the expansion cycle the fluid control system is operated to release the fluid pressure in the bladder 16 by allowing outflow of fluid from the bladder 16 back to the control system. The bladder 16 thereby deflates and the body segments 10 move back to their initial undeformed shape so that the expander 1 moves back to the radially unexpanded mode thereof. Optionally, the fluid pressure in the bladder is reduced to below the hydrostatic head, causing the segments to bend inwards. As a result the expander 1 is pulled by conduit 26 a short distance further into the sleeve 36 .
Subsequently the above expansion cycle is repeated as many times as needed to expand successively the bell portion 38 of the casing and the remainder casing portion 41 or a desired length thereof.
During expansion of the bell portion 38 of the casing, the sleeve 36 is expanded simultaneously with the bell portion 38 . Upon expansion of the sleeve 36 , the plastic hinges 43 deform plastically. The wall sections between the respective hinges 43 rotate thereby opening-up the slots 40 ( FIG. 3B ). Such rotation causes the sleeve 36 to shorten, and the diameter increase of the sleeve 36 is accommodated by deformation of the hinges 43 .
By virtue of opening-up of the slots 40 , the expansion force required to expand the sleeve 36 is significantly lower than the force required to expand the casing 32 . Therefore, simultaneous expansion of the sleeve 36 and the bell portion 38 of the casing 32 requires only a slightly higher force than the force required to expand the casing 32 only. It will be understood that the inner surface of the sleeve 36 and the inner surface of the remainder casing portion 41 are expanded to the same diameter. This implies that the inner surface of the bell portion 38 of the casing is expanded to a larger diameter than the inner surface of the remainder casing portion 41 . The difference between the inner diameter of the bell portion 38 and the inner diameter of the remainder casing portion 41 after the expansion process, is substantially equal to twice the wall thickness of the sleeve 36 . The wall thickness of the sleeve 36 does not change during expansion because the deformation is concentrated in the plastic hinges 43 .
Furthermore, the sleeve 36 has a relatively large tendency to spring back after expansion because elastic relaxation of the sleeve is governed by elastic reverse bending of the hinges 43 rather than elastic contraction in circumferential direction as occurs in the casing 32 .
The tack-welds 39 are sheared-off during expansion of the bell portion 38 due to differential axial shortening of the sleeve 36 and the bell portion 38 as a result of the expansion process.
Subsequent stages of the expansion process are shown in FIGS. 4-6 indicating gradual progression of the expander 1 through the casing 32 .
After the casing 32 has been expanded, the expander 1 is removed from the casing and the retrieval tool 46 is lowered on running string 48 through the casing 32 . Upon arrival of the retrieval tool 46 at the sleeve 36 , lowering is slowly continued until the retrieval tool latches to the sleeve 36 by virtue of latching of the spring-loaded pins 50 into the openings 52 of the sleeve 36 . The retrieval tool 46 is then pulled upwardly on running string 48 .
As shown in FIG. 7B , the sleeve 36 is thereby radially compressed as it moves upwardly into the remainder casing portion 41 . Compression of the sleeve 36 does not require a high compression force since such compression is accomplished by closing of the slots 50 of the sleeve 36 . Furthermore, the tendency of the sleeve to spring back elastically, and the pulling force exerted to the sleeve by the retrieval tool, enable easy removal of the sleeve 36 from the casing 32 . The sleeve 36 is finally removed from the casing 32 at the upper end thereof.
In this manner it is achieved that the lower portion of the casing 32 is expanded to a larger diameter than the remainder of the casing so that a subsequent casing (not shown) can be installed and expanded below the casing 32 whereby an upper end portion of the subsequent casing extends into the bell portion 38 of the casing 32 .
Thereby an overlap is created between the casing 32 and the subsequent casing, which enables fixing and sealing of the casings to each other.
The resistance to expansion of the sleeve can be reduced further by reducing the width H of the hinges and/or by reducing the wall thickness of the sleeve at the hinges and/or by increasing the length of the slots.
Instead of fixing the sleeve to the casing by welding, the sleeve can be fixed to the casing by a layer of adhesive which fails upon differential movement between the sleeve and the casing during expansion. It is thereby ensured that the sleeve is secured in place until the entire sleeve has been expanded. Also the body segments can be spot-welded to the tubular element at their respective mid portions.
Instead of using the expander described above, a conventional expander cone can be used, for example an expander cone which is pulled, pumped or pushed through the casing.
Instead of using the retrieval tool described above, a retrieval tool can be used which is connected to the expander and therefore moves simultaneously with the expander through the casing. In such application the sleeve is removed from the casing simultaneously with expansion of the remainder casing portion.
Instead of the expander body being provided with slots having opposite ends near the respective ends of the expander body, the expander body can be provided with slots which extend only along a portion of the length of the expander body and which are arranged in a longitudinally overlapping arrangement. Such arrangement can be, for example, similar to the arrangement of the slots of the sleeve shown in FIGS. 3A , 3 B.
In addition to operating the fluid control system so as to pump pressurised fluid via the conduit into the bladder, the fluid control system can be operated to exert suction to the bladder so as to extract fluid from the bladder causing inward bending of the segments of the expander body. In this manner the expansion ratio of the expander can be increased.
Instead of applying a sleeve with hinges which deform plastically, a sleeve can be applied with hinges which deform purely elastically, such as, for example, a sleeve made of shape memory metal.
Another example of a suitable sleeve is a sleeve provided with slots defining a pattern of bi-stable cells, each cell being capable of assuming a first stable configuration and a second stable configuration, whereby the sleeve has a larger inner diameter when the cells are in their respective second stable configurations than when the cells are in their respective first stable configurations. An example embodiment of such sleeve is the tube formed of bi-stable cells disclosed in GB-A-2368082.
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A method of expanding a tubular element is provided, the tubular element having a first portion to be expanded to a first inner diameter and a second portion to be expanded to a second inner diameter larger than the first inner diameter. The method comprising:
a) arranging an expandable sleeve of selected wall thickness in said second tubular element portion; b) positioning an expander in the tubular element; c) operating the expander so as to expand said first tubular element portion to the first inner diameter, and operating the expander so as to expand the sleeve to an inner diameter substantially equal to the second inner diameter minus double the wall thickness of the sleeve; and d) retrieving the sleeve from the tubular element.
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FIELD OF THE INVENTION
The invention relates to a belt drive including a toothed belt and toothed wheel which have a tooth system constituted by engaging tooth ribs and tooth grooves.
The operating characteristics of such belt drives are determined, amongst other things, by two important parameters, namely on the one hand by the side guide on the toothed belt and on the other hand by the development of operating noise.
DESCRIPTION OF THE PRIOR ART
In order to prevent the toothed belt running laterally off the toothed wheel, the toothed wheel has been provided with lateral webs. This makes the manufacture of the toothed wheel more expensive. An additional factor is that the lateral contact surfaces increase the wear and the operating noise. The toothing has also been divided into a number of rows which are offset from one another in such a manner that the lateral surfaces of the tooth ribs of one row were situated in front of the tooth grooves of the laterally adjacent row and thus constituted lateral contact surfaces. The problem of wear and of operating noise, however, remained. The manufacture of the toothed wheel was also as expensive as before since a number of component wheels had to be manufactured and joined together offset from one another.
In order to reduce the operating noise, noise-damping material has been arranged between the engaging tooth ribs and tooth grooves, whereby the wear resistance of the belt drive decreased and the manufacturing costs increased.
It is the object of the invention to improve the operating characteristics of the belt drive in a manner which is simple from the manufacturing point of view.
SUMMARY OF THE INVENTION
In order to solve this object the belt drive of the type referred to above is characterised in accordance with the invention in that the toothing on at least one section of the length of the tooth ribs and the tooth grooves extends in an arcuate shape over the toothed belt and the toothed wheel.
The arcuate shape of the tooth ribs and the tooth grooves produces an automatic self-centering of the toothed belt on the toothed wheel without the requirement for lateral contact surfaces. The consequence is a corresponding simplification in manufacture. There is also no risk that the toothed belt moves up the tooth ribs on the toothed wheel when even small lateral deflections occur.
Above all, the operating noises of the belt drive are enormously reduced. The tooth ribs and tooth grooves no longer mesh together simultaneously over their entire breadth (linearly) but mesh progressively point by point. The polygon effect, which could not be avoided with conventional belt drives, is practically completely eliminated. The polygon effect results from the fact that the point of engagement of the toothed belt with the toothed wheel periodically alters in the radial direction as a result of the conventional toothing, which is directed linearly perpendicular to the direction of movement. This results in the toothed belt impinging against the toothed wheel with a certain radial velocity component. Tests have shown that this impingement caused by the polygon effect represents the main cause for the production of operational noise. Since the arcuate toothing in accordance with the invention eliminates this effect there is a substantial lack of noise.
The toothed belt thus runs with extremely low vibration so that toothed tension rollers, as were otherwise necessary for the purpose of vibration damping, can be omitted.
A further advantage of the belt drive in accordance with the invention is produced if the toothed belt runs in the form of a conveyor belt tangentially over horizontal, cylindrical support rollers. With conventional toothing, each tooth groove results in sinking and each tooth rib in rising of the toothed belt. The toothed belt thus "chatters" over the support rollers. The same effect is produced, if not quite so markedly, when a toothed belt with conventional is toothing is guided around a cylindrical deflection roller. With the arcuate toothing in accordance with the invention this "chattering" does not occur.
The belt drive in accordance with the invention makes a tooth loading possible which is at least 5% higher compared to conventional toothing under conditions which are otherwise the same by reason of the fact that the length of the tooth ribs is larger than the breadth of the toothed belt. The length over which engagement occurs is thus increased so that the increased tooth loading does not exceed the permissible flank pressure.
The invention basically permits any desired arcuate shape. It is, however, advantageous for manufacturing reasons to make the arcuate sections of the tooth ribs and the tooth grooves of circular arcuate shape.
The invention also imposes no limit as regards the tooth pitch. It is, however, particularly advantageous in this connection that the shape of the toothing is such that a forwardly situated tooth rib in the direction of movement only terminates its engagement movement when the subsequent tooth rib has already started its engagement movement. This promotes operational silence of the belt drive.
It can be advantageous under certain circumstances for producing a substantial overlap to construct the arcuate toothing of elliptical shape, the major axis of the ellipse being directed in the direction of movement of the toothed belt and the toothed disc, respectively.
A further preferred feature is that a respective linear section is connected on both sides to the arcuate sections of the tooth ribs and the tooth grooves. Toothing is thus produced whose linear limbs are connected together by an arc. Gaps can readily be provided between the individual sections of the tooth ribs.
It is proposed in an important embodiment of the invention that the toothing be divided into at least two rows extending in the direction of movement. Each row is occupied by tooth ribs and tooth grooves, widely varying shapes being possible. Thus the tooth ribs and tooth grooves of adjacent rows can merge directly into one another. Gaps can also be provided between the tooth ribs of adjacent rows which facilitate the escape of air during the engagement process. It is particularly advantageous to offset the tooth ribs and the tooth grooves in one of the rows of the toothing in the direction of movement with respect to that in the adjacent row. This also facilitates the escape of air and further contributes to increasing the operational silence of the belt drive.
The tooth ribs and the tooth grooves in adjacent rows of the toothing preferably constitute mutually offset semi-arcs. A particularly simple pattern is thereby produced. A particular advantage is also achieved if the crests of the arcs of the toothing are directed in the direction of movement of the toothed belt and the toothed wheel, respectively. A self-centering action is in fact produced which automatically guides the toothed belt back into the correct meshed position if an external intervention should have temporarily disturbed the centering.
In this connection, it is proposed in an embodiment of the invention that the tooth ribs and the tooth grooves in adjacent rows of the toothing constitute arcs directed in opposite senses to one another. The self-centering effect is thus produced also with reversing direction of movement of the belt drive.
It is proposed in an important embodiment of the invention that the tooth ribs of the toothed belt and the tooth grooves of the toothed wheel each have a constant breadth whilst the tooth grooves of the toothed belt and the tooth ribs of the toothed wheel taper towards their ends. The advantage achieved thereby relates to manufacture. When manufacturing the toothed wheel a profiled milling machine is used which is guided on an arcuate path and thus mills a tooth groove. For the next tooth groove the system is advanced by one tooth pitch. The tooth grooves are thus milled on their convex surface by the inner side of the milling machine in its first position whilst the concave flanks are subjected to the action of the outer side of the milling machine in its second position. The important simplification resides in the fact that the pivotal path of the milling machine remains constant--with a circular arcuate shaped toothing of the pivotal radius of the milling machine. The same conditions, but mirror reversed, are present when manufacturing the toothed wheel shape for the toothed belt.
It is further advantageous that a channel of constant breadth extends in the base of each tooth groove in the toothed belt. Its depth is limited by the longitudinally extending wire strands which are embedded in the material of the toothed belt. The advantage in this case again relates to the manufacturing process.
The mould for producing the toothed belt, is as mentioned, constructed in the form of a toothed wheel. The wire strands are tightened by means of this toothed wheel. In order to prevent the wire strands from constituting the bases of the tooth grooves in the finished toothed belt, each tooth rib in the mould carries a so-called winding protrusion of very small breadth. If the winding protrusions were to be formed together with the tooth grooves of the mould, the winding protrusions, and also the tooth ribs of the mould, would have a breadth which decreases towards the edges. This is unacceptable by reason of the breadth of the winding protrusions which is in any event extremely small. Accordingly, when machining the front flanks and the rear flanks of the winding protrusion, the pivotal path, optionally the pivotal radius, of the milling machine (a separate machine is used) is altered such that the breadth of the winding protrusions remains constant. This then produces the constant breadth of the channels in the tooth grooves of the toothed belt. The geometrical relationships, namely the tooth pitch, the arcuate shape of the toothing and its breadth, are so selected that not only is, as mentioned, a winding protrusion of constant breadth produced but also that the breadth of the tooth ribs of the mould (that is to say the tooth grooves of the toothed belt) does not fall below a minimum breadth at their ends. This is determined by the breadth of the base of the winding protrusion.
It is further proposed in an important embodiment of the invention that the arcs of the toothed belt are of different curvature to the arcs of the toothed wheel. This offers an optimum possibility of controlling the meshing process of the toothing. Thus the beginning of the meshing can occur with a small clearance so that practically no friction occurs. The clearance can then be progressively reduced until clearance-free meshing is produced.
The invention will be described below in more detail with reference to preferred exemplary embodiments in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 8 of the drawings are plan views of the profiled side of different toothed belts, the contour of the toothed belt being indicated on the left-hand side in each case. A few tooth ribs of the toothed wheel are indicated between the tooth ribs of the toothed belt in the embodiment shown in FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The toothed belt 1 shown in FIG. 1 is provided with tooth ribs 2 and tooth grooves 3. The tooth ribs 2 are hatched in this case--as also in all the other Figures--for reasons of clarity.
The tooth ribs 2 and the tooth grooves 3 extend in an arcuate shape over the breadth of the toothed belt 1 symmetrically with respect to its longitudinal central line 4. The gear tooth system is of circular arcuate shape in the present case.
The dimension x, measured in the longitudinal direction of the toothed belt 1, of each arc from the longitudinal center line 4 to the edges of the toothed belt, plus the thickness of the tooth ribs is larger than a tooth pitch y. It is thus ensured that a forwardly situated tooth rib in the direction of movement only terminates its meshing movement when the subsequent tooth rib has already started its meshing movement.
The toothed belt 1 is provided in the present case for non-reversible operation, namely for upward movement in FIG. 1. The crowns of the arcs thus point in the direction of movement.
The toothed belt 1 together with an associated toothed wheel constitutes a belt drive in accordance with the invention. The toothed wheel is of complementary construction as regards its tooth ribs and tooth grooves. A separate illustration of it is thus omitted.
The belt drive ensures self guiding of the toothed belt on the toothed wheel, whereby there is no danger of the toothed belt running up the tooth ribs of the toothed wheel immediately a lateral deflection occurs. Instead, the gear tooth system, which is arcuate in the direction of movement, produces an automatic recentering of a laterally deflected toothed belt. The toothed belt operates with an extremely high degree of operational silence and minimal noise development since no polygon effect occurs. Toothed tension rollers for oscillation damping are not necessary. The belt can also run over cylindrical support rollers tangentially without "chattering". The same applies also to passing around cylindrical deflection rollers.
It will be apparent from the drawing that the tooth ribs 2 are of constant breadth whilst the tooth grooves 3 taper from the center towards the edges. This is the result of a particularly simple manner of manufacture. The tool, which is in the nature of a toothed wheel, for forming the toothed belt is produced by milling its tooth grooves, which later form the tooth ribs of the toothed belt, by a milling machine whose pivot point is advanced in each case by one tooth pitch. The tooth ribs of the tool, which later form the tooth grooves in the toothed belt, are thus milled on the convex flank from the internal surface of the milling machine in its first position whilst the concave flanks are subject to the action of the outer surface of the milling machine in its second position. The crucial simplification resides in the fact that the pivotal radius of the milling machine need not be altered. This advantage is particularly effective also in the manufacture of the actual toothed wheel.
The drawing shows further that the base of each tooth groove 3 has a channel 5 of constant breadth which extends to wire strands 6 which are embedded in the material of the toothed belt l. The channel 5 is produced by the so-called winding protrusion on the tooth ribs of the tool by means of which the wire strands 6 are tightened. When machining the flanks of the winding noses, the associated milling machine is also advanced by one tooth pitch, whereby its pivotal radius also alters so that the winding noses are produced with a constant breadth. Since they are extremely narrow, tapering towards the edges could not be tolerated.
The embodiment of FIG. 2 differs from that of FIG. 1 in that the tooth system is divided into two rows 7 and 8 extending in the direction of movement and that the tooth ribs and tooth grooves of one row are offset with respect to those of the other row. This produces a further increase in the operational silence of the belt drive. The tooth ribs and tooth grooves of the rows are constituted by mutually offset semi-arcs.
The tooth system is also divided into the two rows 7 and 8 in FIG. 3. However, the tooth ribs and the tooth grooves of the two rows directly adjoin one another. However, the toothed wheel in this embodiment can be manufactured in a single piece. When milling the tooth grooves of the toothed wheel, the milling machine passes through a reversal point on their peripheral centre line. This may be seen in FIG. 3 at the lower arcuate transitions of the tooth ribs 2 on the longitudinal central line 4 of the toothed belt. Peaks are produced here if the toothed wheel is manufactured from two separate, connected wheels.
A corresponding embodiment is illustrated in FIG. 4. This embodiment otherwise differs from that of FIG. 3 in that the tooth ribs 2 and the tooth grooves 3 in the two rows 7 and 8 each comprise semi-arcs.
The embodiment of FIG. 5 also follows that of FIG. 3. It relates to a modification in which the tooth ribs 2 and the tooth grooves 3 of the two rows 7 and 8 are offset from one another.
The belt drives described above are preferably provided for an irreversible direction of movement, the crests of the arcs of the toothing pointing in the direction of movement. The embodiment of FIG. 6, on the other hand, is so constructed that the belt drive develops the advantage of self-centering in both directions of movement. For this purpose, the tooth ribs 2 and the tooth grooves 3 of the two rows 7 and 8 constitute arcs which are directed in opposite senses to one another. The same applies also to the embodiment of FIG. 7, whereby in this case the tooth ribs 2 and the tooth grooves 3 of the two rows 7 and 8 are offset from one another in the direction of movement.
The embodiment of FIG. 8 substantially corresponds to that of FIG. 1, but with the proviso that only the central section of the toothing, namely the region on both sides of the longitudinal sectional line 4, is of arcuate construction. Linear sections are connected to the arcs at these sides.
Finally, FIG. 9 shows, in addition to the tooth ribs 2 of the toothed belt, further tooth ribs 7 which belong to the toothed wheel which is otherwise not shown. As may be seen, the curvatures of the tooth ribs 7 do not coincide with those of the tooth ribs 2. The meshing characteristics of the belt drive may be influenced in this manner with very simple means. Meshing can begin with tooth clearance, this progressively decreasing and finally merging into a point engagement on both sides.
Furthermore, modifications are of course possible within the scope of the invention. Thus instead of circular arcuate toothing, elliptical toothing can be selected, the major axis of the ellipse coinciding with the longitudinal central line 4. This construction will be selected if the overlap is substantially to exceed one tooth pitch. Any desired tooth pitch can be selected differing from the illustrated tooth pitches. Finally, the invention may be used on belt drives of any desired type, whereby it is to be stressed that higher powers and higher speeds may be achieved in every case than is possible with conventional belt drives, the toothing of which extends in a straight line transverse to the direction of movement. The invention is suitable above all for belt drives with toothed belts of thermoplastic polymer materials.
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A belt drive includes a toothed belt and a toothed wheel which have engaging tooth ribs and tooth grooves. The tooth ribs and the tooth grooves extend in an arcuate shape over the breadth of the toothed belt. The toothed wheel is of complementary construction. This results in automatic self guiding of the toothed belt with a high load bearing ability. The belt drive runs extremely quietly and with low vibration. This applies also to the case in which the belt runs tangentially over a support roller or runs round a support roller.
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BACKGROUND OF THE INVENTION
This invention relates to the field of intravascular catheters, and more particularly to an inflatable member formed in part of liquid crystal polymeric material.
Balloon catheters generally comprise a catheter shaft with a inflatable member on the distal end of the shaft, and are used in a number of procedures, such as percutaneous transluminal coronary angioplasty (PTCA). In PTCA the balloon catheter is used to restore free flow in a clogged coronary vessel. The catheter is maneuvered through the patient's tortuous anatomy and into the patient's coronary anatomy until the inflatable member is properly positioned across the stenosis to be dilated. Once properly positioned, the inflatable member is inflated with liquid one or more times to a predetermined size at relatively high pressures (e.g. greater than 4 atm) to reopen the coronary passageway.
The material used to make the catheter inflatable member must have sufficient strength to contain the inflation fluid without bursting. In addition, the degree of compliance must be tailored so that the inflatable member expands during use, but does not overexpand and damage the body lumen. During extrusion and subsequent processing of polymeric inflatable member tubing, the longitudinal and radial orientation of polymeric molecules can be tailored to increase the longitudinal and radial strength of the inflatable member produced therefrom. Because the force required to blow a inflatable member from tubing destroys some of the longitudinal orientation produced during extrusion, the extrusion process, and particularly the draw down ratio, is designed around optimizing the molecular orientation that is ultimately produced in the finished inflatable member. The strength of a inflatable member is typically expressed in terms of hoop strength and burst pressure.
Inflatable members formed from thermoplastics such as PET blended with liquid crystal polymers to improve the compliance of the inflatable member have been suggested (U.S. Pat. No. 5,306,246 (Sahatjian et al.)). However, Sahatjian et al. fails to address the problem of lower burst pressures of inflatable members produced from blends of a minor amount of liquid crystal polymer with a major amount of a non-liquid crystal polymer, relative to inflatable members produced from only thermoplastics such as PET.
Therefore, what has been needed is a catheter with an inflatable member having improved strength characteristics. The present invention satisfies these and other needs.
SUMMARY OF THE INVENTION
The invention is directed to a catheter which has an inflatable member formed of a polymeric blend comprising a minor amount of a liquid crystal polymeric material and a major amount of a non-liquid crystal polymeric material. There are many suitable liquid crystal polymeric materials that may be used, and a presently preferred example is VECTRA sold by Hoechst-Celanese. The non-liquid crystal polymeric material used in the LCP blend may be any extrudable thermoplastic polymer, and presently preferred examples are nylon 12 available from EMS, and PEBAX available from Atochem.
The LCP acts as reinforcement in the polymer matrix, similar to fiber reinforced composites, but at significantly lower dimensional scale and ease of processing. One presently preferred embodiment of the invention is a dilatation catheter which has an elongated catheter shaft and an inflatable dilatation member on a distal portion of the catheter. Conventional catheter design may be used, including over the wire, fixed wire and rapid exchange designs, having a single shaft with dual lumens or a multimembered shaft with inner and outer tubular members.
Liquid crystal polymers exhibit crystalline behavior in the liquid phase. The orientation of the molecules in the liquid state can be maintained in the solid state due to the long relaxation times of these molecules. The molecular orientation improves the strength of a polymeric component in the direction of orientation. The extent of molecular orientation can be expressed in terms of the Herman's orientation parameter (S) with a scale of from 0 (no orientation) to 1 (very highly oriented), which is a factor of the draw-down ratio (i.e. the ratio of the diameter of the die to the diameter of the finished extrudate) used during extrusion and viscosity. Liquid crystal polymers can be made to solidify after extrusion with an even greater degree of molecular orientation than ordinary polymers, and thus can be used to form ultra high strength articles. However, the high molecular orientation may result in disadvantageous characteristics in an inflatable member, such as little ability to withstand loads applied transverse to the orientation direction, increased stiffness, and poor bonding between layers. These disadvantages are avoided by the polymer blend of the invention. In the polymer blend of the invention, the Herman's orientation parameter is about 0.5 or less. Thus, the inflatable member of the invention formed from a minor amount of liquid crystal polymeric material existing as elongated liquid crystal polymeric fibers having an aspect ratio of about 10 to about 100, and preferably about 50 to about 100 has improved strength characteristics.
The inflatable member is formed from a blend comprising a minor amount, preferably less than about 20 to about 10 percent by weight of the blend, of liquid crystal polymeric material, with a major amount, preferably about 80 to about 90 percent by weight of the blend, of a non-liquid crystal polymeric material (hereafter, the LCP polymeric blend). By blending the liquid crystal polymeric material with another thermoplastic material the transverse strength of the inflatable member produced therefrom is increased. Additionally, it has been found that an inflatable member having LCP fibers that are highly oriented in the machine direction has improved mechanical characteristics. Specifically, if the aspect ratio of the liquid crystal polymer fibers is greater than 100, the LCP polymeric blend has mechanical characteristics similar to a continuous long-fiber-reinforced composite. As a result, the main load on the inflatable member is taken by the fibers (iso-strain process), as opposed to short fiber or dispersed phase composites where the load is shared by the filler and the matrix (iso-stress). Therefore, the LCP polymeric blend having a high aspect ratio can be used to produce thin walled inflatable members with improved burst pressures. Additionally, the risk of inflatable member overexpansion during use is reduced, because the high aspect ratio results in an advantageous reduction in inflatable member compliance.
An inflatable member formed from the LCP polymeric blend of the invention has improved strength and optimal compliance due to the high aspect ratio produced during extrusion. These and other advantages of the invention will become more apparent from the following detail description of the invention and the accompanying exemplary drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view partially in section of a inflatable member catheter which embodies features of the invention.
FIG. 2 is a longitudinal cross-sectional view of the shaft of the catheter shown in FIG. 1, in circle 2 .
FIG. 3 is a transverse cross-sectional view of the shaft shown in FIG. 2, taken along lines 3 — 3 .
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the catheter 10 of the invention generally includes an elongated catheter shaft 11 with an inflatable member 12 on a distal portion of the catheter shaft which has an interior in fluid communication with a lumen within the shaft, and an adapter 13 mounted on the proximal end of the catheter shaft.
The catheter shaft 11 has an outer tubular member 14 and an inner tubular member 15 disposed within the outer tubular member 14 and defining with the outer tubular member 14 an annular lumen 16 which is in fluid communication with the interior of the inflatable member 12 . The inner tubular member 15 has an inner lumen 17 extending therein which is configured to slidably receive a guidewire 18 suitable for advancement through a patient's coronary arteries. The distal end of the inflatable member 12 is sealingly secured to the distal end of the inner tubular member 15 and the proximal end of the inflatable member 12 is secured to the distal end of the outer tubular member 16 .
In the embodiment illustrated in FIG. 1, the outer tubular member 16 has a relatively stiff proximal shaft section 20 tapering to a smaller diameter and more flexible distal shaft section 21 . The distal end of the proximal shaft section 20 is secured to the distal end of the distal shaft section 21 at lap joint 22 formed by suitable means such as heat or laser fusion or commercially available cyanoacrylate adhesive. However, a variety of suitable configurations may be used to connect the distal shaft section 21 to the proximal shaft section 20 . The inner tubular member 15 extends the length of the catheter and may be formed of suitable materials, including but not limited to polyethylene, HYTREL, or the like.
Inflatable member 12 is formed from a blend of a minor amount of a liquid crystal polymeric material and a major amount of an non-LCP polymeric material (LCP polymeric blend). The LCP polymeric blend is extruded as tubing with high aspect ratio LCP fibers, which is then processed into an inflatable member 12 using conventional procedures. The melt processed, e.g. extruded, LCP polymeric blend has a high aspect ratio of about 10 to about 100, and preferably greater than about 50, and most preferably greater than about 80. In the extrusion process, a high draw down ratio and a viscosity ratio close to unity is used to produce the high molecular orientation. The draw down ratio, as measured by the outer diameter of the extrusion die divided by the outer diameter of the extruded tubing, is not less than about 2, preferably not less than about 3, and is typically about 3 to about 10. The viscosity ratio is not less than about 1.1, and is typically about 1.1 to about 3.0. Because the inflatable member is produced from extruded tubing having a high aspect ratio, the load during pressurization of the inflatable member will be absorbed by the high strength LCP fibers. Consequently, the inflatable members of the invention have high hoop strength. The hoop strength is typically about 1200 atm to about 2500 atm, and preferably about 2000 atm. The burst pressure is about 14 atm to about 27 atm, and preferably about 23 atm, and the tensile strength is about 340 atm to about 1000 atm.
In a presently preferred embodiment, the inflatable member is formed by blow molding the extruded tube at 90° C. to 200° C., and 50 psi to 400 psi, depending on the thermoplastic material used. The extrusion process results in uniaxially oriented LCP fibers, and the blowing process imparts some radial orientation to the LCP fibers. Alternatively, a rotating die and/or mandrel extrusion can be used to produce an extrudate having fibers with longitudinal and radial orientation. The strength of the inflatable member is related to the longitudinal and radial orientation of the LCP fibers, and the extent of orientation should be tailored to ensure that the inflatable members produced will not have radial failure during use.
High strength inflatable members of the invention provide increased protection against the risk of bursting during pressurization, and can be used to produce strong, thin walled inflatable members. In an expanded state, the inflatable member outer diameter is generally about 0.1 cm to about 6 cm, and the length is about 10 mm to about 50 mm, and preferably about 20 mm.
A variety of suitable thermoplastic polymers may be used for the non-liquid crystal polymeric matrix in the LCP polymeric blend. The overall softness of the inflatable member can be improved by using soft thermoplastic elastomers or polyolefins. Alternatively, stiffer engineering polymers may be used as the matrix polymer. Presently preferred matrix polymers are polyether block amides such as PEBAX, and polyamides such as nylon 12. Suitable thermoplastic polymers include, but are not limited to, PET, PEEK, PEN, Nylon, HYTREL, VESTAMID, PPS, and polyethylene.
The liquid crystal polymeric material is a separate phase from the non liquid crystal polymeric material of the blend. Suitable liquid crystal polymeric materials are copolyesters, such as those sold under the trade name VECTRA, and polyesteramides such as XYDAR. In a presently preferred embodiment the invention, the liquid crystal polymeric material and matrix polymeric material are temperature-melt (T-melt) compatible, so that the polymers melt in the same temperature range. The T-melt compatibility is desirable because it avoids the polymer degradation that may otherwise result during extrusion.
In another embodiment, the blend may contain a small fraction of a compatibilizer to improve the adhesion between the LCP and the thermoplastic material, including ionomers such as metal neutralized sulfonated polystyrene, or polypropylene with maleic anhydride.
The length of the dilatation catheter 10 may be about 120 to about 150 cm in length, and typically is about 135 cm in length. The outer tubular member 14 has an OD of about 0.03 to about 0.05 inch (0.76-1.27 mm) and an ID of about 0.025 to about 0.035 inch (0.635-0.899 mm). The outer tubular member 14 may taper in its distal portion to a smaller OD of about 0.04 to about 0.02 inch (1.02-10.55 mm) and a smaller ID of about 0.03 to about 0.015 inch (0.762-0.381). The smaller diameter portion between the taper and the proximal extremity of the inflatable member 12 may be about 5 to about 25 cm in length.
The inner tubular member 15 has an OD ranging from about 0.018 to about 0.026 inch (0.457-0.66 mm), and the ID of the inner tubular member will usually be determined by the diameter of the guidewire 18 which is to be used with the catheter, which may range from about 0.008 to about 0.02 inch (0.203-0.51 mm). The inner diameter of the inner lumen should be about 0.002 to about 0.005 inch (0.051-0.127 mm) larger than the OD of the guidewire 18 to be used. Usually there will be a family of catheters for each size of guidewire with a variety of maximum inflated inflatable member sizes, e.g., 0.5 to about 4 mm in diameter and with various working lengths ranging from about 1 to about 10 cm.
To the extent not previously described herein, the various catheter components may be formed of conventional materials. For example, radiopaque marker 31 may be a gold band and the adapter body may be formed of polycarbonate polymers.
While the present invention has been described in terms of certain preferred embodiments, those skilled in the art will recognize that modifications and improvements may be made to the invention without departing from the scope thereof. For example, while the catheter illustrated has an outer tubular member with proximal and distal sections, and an inner tubular member, a variety of suitable shaft designs may be used including a dual lumen shaft.
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A catheter having an inflatable member formed of a liquid crystal polymeric material. The inflatable member is formed from a blend of a minor amount, preferably less than 10%, of liquid crystal polymer with a major amount of a non-liquid crystal polymer having LCP fibers that are highly oriented in the machine direction. The aspect ratio of the liquid crystal polymeric material fibers is greater than 10, so that the polymer blend has mechanical characteristics similar to a fiber-reinforced composite with improved strength and optimal compliance.
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RELATED APPLICATIONS
This Application claims priority to U.S. Provisional Application No. 60/120,706, filed Feb. 16, 1999, which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention concerns a process for determining the pivot center of proximal and intermediary articulations, also known as joints, of an appendicular skeleton.
BACKGROUND OF THE INVENTION
The appendicular skeleton comprises arms and legs and includes the proximal articulations of those limbs (i.e., hips and shoulders) and the intermediary articulations (i.e., elbows or knees) and distal articulations (wrists or ankles). The articulations are connected by proximal bone segments (humerus for arms or femur for legs) and distal bone segments (radius for arms or tibia for legs).
It is common for appendicular joints to be replaced with prosthetic devices. During such replacements, it is very important that the joint be properly aligned—a misaligned bone can shorten the lifespan of the replacement joint considerably, for example, as much as by 20% to 50% of the time. Proper alignment using traditional methods requires a significant amount of skill and experience.
During a surgery involving part of the appendicular skeleton, it is important for proper alignment to know the pivot centers of the proximal and intermediary articulations of the skeleton. In fact, when it is necessary to cut the proximal bone segment, for instance, it is important to make the cut exactly at a right angle with respect to the plane connecting these two articulations, or pivot centers. It is also useful to optimize pivot centers of articulations for physical therapy applications, and for sports medicine applications. Determining the pivot point can also be used as a diagnostic tool for tracking the progression of certain bone diseases.
In the case of the hip, for instance, the pivot center corresponds to the articulation center of the hip, which is spherical. This is not the case with a non-spherical articulation, such as, for example, the knee. The pivot center of the knee, for instance, corresponds to the average of a range of points (the “cloud point”) formed by the pivot centers of this non-spherical articulation during the relative movement of the bone segments surrounding it.
Initially, articulations were positioned by observation. This method resulted in a relatively high failure rate, leading to the development of .mechanically assisted methods, such as those reported in the prior art, such as, for instance, the method disclosed by F. Leitner, F. Picard, R. Minfelde et al., Computer - Assisted Surgical Total Replacement of the Knee (published in the Proceedings of the First Joint Conference, Computer Vision, Virtual Reality and Robotics in Medicine, Medical Robotics and Computer Assisted Surgery (1997); and as published by S. L. Delp, et al., Computer Assisted Knee Replacement , Clinical Orthopedics and Related Research, 354, 49-56 (1998). Throughout these methods, a set of data are generated which, when analyzed, provides assistance in locating the ideal pivot point. Prior art techniques for generating data include preoperative imagery, where the pivot point is determined prior to surgery. This method, however, is somewhat complicated and requires sophisticated imaging equipment and technicians, and sometimes engineers. In general, traditional techniques used to generate these data remain somewhat rudimentary, and inaccuracies in these data generation techniques create inaccuracies in the pivot points generated even by computer-assisted techniques.
One improvement to traditional pre-surgical determinations of the pivot point utilizes at least four individual markers (optical-type, super-resonant, magnetic or inertial) which are surgically screwed into the bones, and each of which each is associated to a means of detection, such as a camera connected to a computer. This allows the medical staff to monitor the positioning and orientation of each marker in real time during a surgical procedure. For purposes of this invention, positioning is the x, y and z cartesian coordinates of the marker, and orientation is the polar coordinates of this marker, expressed at the point of reference point.
A When using this prior art method on a leg, for instance, the first two markers are affixed on either side of the knee, at the extremities toward the tibia and the femur. Two additional markers are affixed on the pelvis and a foot bone, respectively. The patient is placed horizontally, with his femur raised and restrained from movement, and then the tibia is moved toward the motionless femur. A computer is used during this movement to determine the maximal invariancy point, which corresponds to the pivot center of the knee articulation. The pivot center of the hip articulation may be determined in the same manner by moving the femur toward the trunk, and the pivot center of the ankle articulation by moving the foot toward the tibia
This solution has certain drawbacks. It requires a large number of markers, and since each marker must be attached to the corresponding bone, it is necessary to affix with screws at least some of these markers to the bone in question. These affixing procedures are time-consuming and can be rather traumatizing for the patient. Also, many methods of moving the body to collect data points for determining the pivot point are used, with differing outcomes. Lastly, differences in bone structure between patients make standardization of traditional techniques for locating optimal pivot points difficult.
Thus, it would be useful to have an optimized positioning method for use with computer assisted orthopedic surgery, which would provide accurately and reliably provide data for generating an optimal articulation pivot point, and which would be faster and less traumatizing for the patient than traditional methods of determining an optimal pivot point. It would also be advantageous to develop a standard technique which could be used for any bone structure and which could account for a wide variety of bone deformities.
The present invention overcomes these drawbacks, in that it provides a means for determining the pivot center of an articulation using only a single marker.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for optimizing the alignment of orthopedic prosthetic devices.
It is a further object of the invention to provide a method of generating data points from physical movements for use in determining the optimal pivot point of a bone articulation that is more accurate and reproduceable than prior art methods.
It is yet another object of the invention to provide a method for determining an optimal pivot point that is fast and less traumatic to the patient as compared to prior art methods.
It is another object of the invention to provide an optimal movement sequence for generating data points which can be used to reliably and accurately locate optimal pivot points of articulations.
It is also an object of the invention to locate an optimal pivot point using a single marker.
In this regard, the invention is a method for determining pivot centers for the proximal and intermediary articulations of an appendicular skeleton, for use during computer-assisted orthopedic surgery or other diagnostic or rehabilitative treatments. The novel method of the invention requires the affixation of a single marker to the bone, which may be affixed by screws or by less traumatic methods such as but not limited to external affixation devices such as elastic bands. Pivot centers for proximal and intermediary articulations may be determined through the use of at least one marker placed between intermediary and distal joints, and pivot centers for intermediary and distal articulations may be determined through the use of at least one marker placed over or at least near the distal joint.
Once the marker is affixed to the bone, the pivot center is determined using rotational movements of the appendicular skeleton in accordance with the sequence of the invention. The sequence of the invention utilizes at least the first and second rotations of the proximal bone segment around the proximal articulation in accordance with the first and second axes, sensibly orthogonal to each other, and at least the third and fourth rotations of the distal bone segment around the intermediary articulation, along the third and fourth axes, sensibly orthogonal to each other.
During the movement sequence, data points on the position and orientation of the marker are collected on a continuous basis from a predetermined point of reference, the localizer. Next, from among the resulting data collected on a continuous basis, a minimal number of distinct postures of the skeleton during the movement sequence are selected, and to each posture is ascribed a value representing the position and orientation of the marker in the predetermined point of reference. Next, from all of the values the coordinates of the optimal pivot point. (also called rotational center) of the proximal and intermediary articulations is determined. Once the optimal pivot points are determined, the optimal alignment of the articulations are possible. “Patient” as used herein denotes legged mammals, most particularly people although it is contemplated and within the scope of the present invention that the methods disclosed herein would work with other legged mammals as well.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention shall be described below with reference to the attached drawings, provided solely as non-limited examples, in which:
FIG. 1 is a perspective view diagram of a patient in a supine position, showing three planes and three physiological axes connected to the patient;
FIG. 2 is a side perspective view showing a patient whose appendicular skeleton is undergoing a first movement from a sequence of the procedure in accordance with the invention;
FIGS. 3 is a side perspective view of the appendicular skeleton of a patient that is undergoing a first movement from a sequence of the procedure in accordance with the invention;
FIG. 4 is a top perspective view of the appendicular skeleton of a patient that is undergoing a first movement from a sequence of the procedure in accordance with the invention; and
FIG. 5 is a side perspective view showing a patient whose appendicular skeleton is undergoing a second movement from a sequence of the procedure in accordance with the invention.
FIG. 6 is a schematic representation of the hardware required for determining the optimal pivot point of an articulation in accordance with the method of the invention.
DESCRIPTION OF THE INVENTION
FIG. 1 represents, in a simplified drawing, a patient lying down, with a complete designation in reference 2 . This patient has a trunk 4 , two upper appendicular skeletons 6 and two lower appendicular skeletons 8 .
The position of a patient is defined by three physiological planes, with three corresponding physiological axes. The frontal plane, designated by reference 10 , is associated a beam of frontal axes 12 which are perpendicular to the frontal plane 10 and which therefore extend from the rear to the front of the patient.
The sagittal plane 14 is the median plane of the patient, extending from the medial axis to the lateral side of the patient. A beam of sagittal axes 16 , perpendicular to sagittal plane 14 , are associated with the sagittal plane.
Axial plane 18 is the horizontal plane perpendicular to the frontal plane 10 as well as the sagittal plane 14 , that is going through the cranium of the patient. A beam of axes, called axial 20 , is associated with the axial plane 18 , and perpendicular to it.
FIGS. 2 to 4 show the patient in FIG. 1 undergoing a first movement in the determination procedure described herein, in accordance with the methods of the invention.
The lower appendicular skeleton 8 of the patient 2 includes a proximal articulation 22 , i.e. the articulation of the hip connecting skeleton 8 to trunk 4 , a proximal bone segment 24 , i.e. femur, and intermediary articulation 26 , i.e. the knee and a distal bone segment 28 , i.e. tibia, articulated on the femur 24 , by the knee 26 . The distal segment 28 ends with a distal articulation 30 , i.e. the ankle to which the foot 32 is connected.
The procedure in accordance with the invention simultaneously determines the pivot center of multiple articulations in an appendicular skeleton, such as, for instance, the hip 22 and knee 26 articulations. The preferred embodiment illustrated here will be the hip and knee, although the principles of the invention apply similarly to any set of articulations within the appendicular skeleton, such as but not limited to the articulations of the arm, and the knee-shoulder articulations; Each of these other articulations are also embodiments of the invention and the same principles are used to describe these embodiments as set forth below.
In the illustrated preferred embodiment, hip and knee articulations, an optical marker 34 is placed preferably on the patient's tibia 28 . In all embodiments, it is preferable that the marker be placed between an intermediary articulation and a distal articulation. The invention provides an advantage over the prior art in that markers may be affixed without the use of screws, although traditional methods of using screws to affix markers to the bone may be used. Using the method of the invention, markers may be affixed to a bone, such as a tibia, with glue or an elastic band, or any other suitable means that now exists or may be developed. The marker can be affixed anywhere along the bone, in the case of the illustrated embodiment, the tibia 28 , and is most optimally located where the bone is very near to the skin of the limb.
The marker 34 includes transmitters 40 , in this embodiment most optimally at least three transmitters, connected to a receiver, or locator 42 (such as but not limited to a camera), in contact with a processing device 44 such as but not limited to a computer, as shown in FIG. 6 . The transmitters 40 may be infrared diodes, for example, or any other marker material suitable for use with the invention, including but not limited to ultrasound or accelerometer markers, and the receivers 42 are adapted to receive signals from the transmitters 40 . The marker 34 , locator 42 , and processing device 44 may be any commercially available system, such as that marketed by the company NORTHERN DIGITAL under the trademark OPTOTRAK, as illustrated in FIG. 6 . The receiver insures the locating, on a continuous basis, of the position and orientation of the marker at the point of reference of this receiver. The computer connected to the locator allows measurement and data collection of distinct values indicative of the positions and orientations of the marker.
The starting position of the first movement to which patient 2 is subjected to determines the pivot center of the hip 22 and knee 26 articulations, as illustrated in FIGS. 3 and 4. In this position, seen from the side (FIG. 3 ), the patient's trunk 4 is horizontal, the femur is raised at an angle α of about 60° from the axial axis 20 a going from the articulation of the hip 22 . The main axis 36 of the tibia 28 is inclined with regard to the main axis 38 of the femur 24 , at an angle β of about 90° in that resting position. Moreover, given the above (FIG. 4 ), the femur 24 forms an angle γ with regard to axis 20 a of about −10°.
The first movement of the sequence in accordance with the invention requires a moving, such as but not limited to a pedaling, of the appendicular skeleton 8 combined with a rotation of the skeleton around the axial axis and plane 20 a going through the articulation of the hip 22 . The articulation of the ankle 30 , therefore, is subjected to a movement in the shape of an H helix.
During the pedaling movement, angle α varies alternatingly between around 40° and 60°, angle β varies alternately between around 20° and 120°, while angle y increases continuously from about −10° to 20°. The diameter D of the helix along which the ankle 30 moves is about 30 cm. During this movement, the number of revolutions of the helix is between about 5 and 50, although fewer or more revolutions may be used.
This first movement described with references in FIGS. 2 to 4 prompts three rotations, i.e. a rotation of the femur 24 around the frontal axis and plane 12 a going through the hip 22 , a rotation of this femur around the sagittal axis and plane 16 a going through the hip 22 , as well as a rotation of the tibia around the sagittal axis and plane 16 b going through the articulation of the knee 26 .
During this movement, the locator enables finding the position and orientation of the marker. We select distinct postures through the computer, i.e. 150 in the example in question. This selection is run at regular time periods during this movement. Six values are designated for each posture, i.e. three Cartesian coordinates and three polar coordinates of the marker for the point of reference determined by the locator. This first movement, therefore, results in 900 data points obtained.
The sequence in accordance with the invention includes a second movement shown in FIG. 5 . To carry out this second movement we first place the patient in the position shown with full lines in FIGS. 3 and 4, i.e. femur raised at an angle of 60° from the horizontal plane, and the tibia at a right angle to this femur. Then, while keeping the femur stationary, we pivot the tibia 28 around its main axis and plane 36 , at the dimension of angle γ of about 15°. This rotation movement of the tibia around its axis and plane is done by exercising a continuous pressure on the extremity of the foot 32 , next to the ankle 30 , in the direction of the knee 26 . This second movement is most optimally practiced for 5 to 50 repetitions, back and forth, although more repetitions may be performed.
During this second movement, we select 50 successive positions of the appendicular skeleton, and use the transmitter, receiver and the processor to collect approximately 300 data points for the position and orientation of the marker 34 , although more or fewer values may be obtained and function with the invention. For the embodiment described here, the entire sequence, including the first and second movements, results in approximately 1,200 known data points, or values, collected which correspond to three Cartesian coordinates and three polar coordinates of the marker at the reference point of the locator.
During the sequence, the trunk of the patient must remain relatively immobile within the point of reference of the locator. Light movements of less than 2 mm and rotations of less than 1° are, however, acceptable as long as their occurrences can be deemed as random.
Seven unknowns are consistent for the 200 samples taken throughout the sequence. These are, first of all, the three Cartesian coordinates of the pivot center of the hip, at the reference point of the locator of the three Cartesian coordinates of the pivot center of the knee articulation, at the actual reference point of the marker, as well as distance D separating these two pivot centers.
For j varying from 1 to 200, corresponding to the number of sample positions, we note T ld (j) of the homogeneous matrix known to have been taken from the three Cartesian coordinates and the three polar coordinates of the distal marker (d) measured for each sampling at the point of reference of the localizer (1).
We also note the P di position, i.e. the three Cartesian coordinates at the distal point of reference (d) of the intermediary articulation (i).
We also note the P lp position, i.e. the three Cartesian coordinates at the point of reference of the locator (1) of the pivot center of the proximal articulation (p).
Finally, we note the P li position, i.e. the three Cartesian coordinates at the point of reference of the locator (1) of the pivot center of the intermediary articulation (i).
By definition, the distance D separating the two pivot centers, proximal and intermediary, respectively, corresponds to the standard of the vector shaped by these centers. We can, therefore, note:
D=. . . P
li
−P
lp
P lp is an unknown constant during the 200 samples, which is not the case of P li . But, by definition, we have P li =T ld ·P di . However, T ld is known, and P di does not vary for each of the 200 positions.
We therefore have, for 1=1 to 200
( T ld ( j )· P di −P lp )= D
This leads to obtaining a system of 200 equations with 7 unknowns, which is highly linear and, therefore, does not allow, a priori, solution to be obtained. We, therefore, reformulate this system of equations by adding, for each one of them, either a j included between 1 and 200, or a secondary unknown called εj corresponding to an error term. We then obtain a system of 200 equations with 207 unknowns.
This system allows for an infinite number of solutions; the invention uses the one for which the sum of the squares of the εj error values is minimal. This solution is obtained, for example, by means of a classical-type minimizing algorithm for the smallest squares. We can, for example, use the commonly known LEVENBERG-MARQUARDT algorithm as well as an algorithm applying a gradient descent at a regular pace, or any other suitable algorithm now known or developed in the future.
For the embodiment described here, the use of such a least squares algorithm is preferable. However, it is also possible to solve the system of 200 equations with 7 unknowns without using an error value. In this case, we cut these 200 equations into as many sub-systems with 7 equations, so as to form a partition of 7-equation sub-systems with 7 unknowns, each one allowing a partial solution. We then obtain a number of partial solutions corresponding to the number of the partition sub-system. We then keep a final calculated solution, i.e. by arithmetic averages of the partial solutions. It is anticipated that the method of the invention will generate data which may be analyzed by any suitable commercially available program.
Once the Cartesian coordinates of the pivot centers of the hip and knee articulations are established, the computer determines the axis connecting these pivot centers. The surgeon then proceeds with cutting the femur at a 90° angle from this axis.
The invention has been described as a sequence which prompts a first movement generating three different rotations, then a second movement generating a unique rotation, for a total of four rotations. Each of the 150 positions sampled thus allows to obtain data regarding the three different rotations.
It is also possible to prompt a single movement during which the four rotations mentioned above are activated simultaneously. In this case, a smaller number of sampled positions shall be required, given that each position reveals the four simultaneous positions.
It is also possible to move the patient's appendicular skeleton in a sequence prompting three, even four successive movements, each involving one or two rotations of either bone segment around the corresponding articulation. In this case, if we wish to reach the same degree of precision as in the example described above, it is necessary to proceed with a higher number of samples than in that example.
In the described embodiment, for example, we use an optical-type marker. However, we can use any other marker, such as a magnetic or inertial marker combined with a tracking device which reports the position and orientation of this marker at a determined point of reference.
It is also possible to determine the pivot centers of the elbow and shoulder articulations, by moving the upper appendicular skeleton in accordance with a sequence involving at least two rotations of the humerus, and at least two rotations of the radius.
The procedure in accordance with the invention is preferable to traditional techniques, as it involves just one marker. Moreover, given the nature of the distal bone segment to which the marker is attached, it is not necessary to use screws. Gluing or attaching the marker on this bone segment by means of an elastic band has been found to be sufficient.
The sequence making use of two successive movements involving three different rotations, respectively, and then a sole rotation, is preferable as long as it is simple to undertaken and provides sufficient data to avoid a high number of samples.
It is understood that for example purposes a single representative embodiment is described above, although the invention may be used with many other embodiments, including all appendicular articulations. It should be understood that various changes and modifications to the embodiment described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be within the scope of the claims.
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A system for determining pivot centers for proximal and intermediary articulations of an appendicular skeleton. The system includes a single marker affixed to a bone, the marker having a signal transmitter; a sequence involving at least one movement for moving a portion of the appendicular skeleton; a signal receiver for collecting data points correlating to the position and orientation of the marker; at least one processing device for selecting a number of skeletal positions during the sequence using the collected data points; and for assigning a value to each posture representing the position and orientation of the marker in a predetermined point of reference, and an algorithm for determining the coordinates of the rotational centers of the proximal and intermediary articulations using the assigned values.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is entitled to the benefit of and incorporates by reference essential subject matter disclosed in international Patent Application No. PCT/DK2003/000422 filed on Jun. 20, 2003 and Danish Patent Application No. PA 2002 00966 filed on Jun. 23, 2002.
FIELD OF THE INVENTION
The invention concerns a power converter for use in green power applications, and concerns particularly a module concept. “Green power” is the term used for energy sources like wind, sun or fuel cells, and the inventive power converter can be used for these different sources of electrical energy.
BACKGROUND OF THE INVENTION
The power generated by green power units is converted into a voltage and a frequency suited to the commercial mains. Conversion is typically done by using a switch mode DC/DC-converter followed by a conversion into AC. DE 199 19 766 A1 describes the use of parallelled DC/DC-converters that are electrically connected to the same DC/AC-inverter. In this way, all DC/DC-converters feed energy to a common DC-bus, and advantageously only one DC/AC-inverter is used. This design is centered about a central microprocessor solution of the power converter, which microprocessor controls the connected DC/DC converter. Due to this centralised control structure, the number of additional DC/DC converters is limited as is the possibility of simultaneously using DC/DC converters for different types of green power. The modules are not coordinated with each other and act as slaves with only limited control capability.
SUMMARY OF THE INVENTION
A first object of the invention is to enable independent control in each of the modules used in the system, hereby providing an easy form of controlling power switches used inside a power converter.
A second object of the invention is to provide a modularized power converter which exhibits an improved electrical efficiency compared to prior art.
These objects are met with a power converter according to the independent claim.
Advantageously, a system with distributed intelligence is achieved. As each module has its own controller and communicates via a bus, each module controls itself according to commands or information received from other modules. Thus, a high degree of load management and load distribution is possible. But also flexibility is achieved. Exchanging a photovoltaic DC/DC module with a fuel cell module is possible, because the controller on the module has all control strategies at hand. The same DC/AC-inverter can be used. Further, the inventive power converter has the advantage, that the DC-input from the green cell is decoupled from the output of the grid connected inverter. This means, that the green cell is not affected by the 100/120 Hz ripple caused by the fact, that the power is not constant on the output of a single phase inverter. When having an independent controller on the DC/DC-converter module, this controller can modulate the power switches to suppress ripple retroaction. The inventive design further has the advantage, that the placement of the transformer on the DC/DC module makes exchange of a fuel cell DC/DC-converter module with a solar cell DC/DC-converter module relatively inexpensive. If the transformer was placed on the DC/AC-inverter module, then this also had to be replaced.
Advantageously, the first module comprises a current sourced inverter and the second module a voltage sourced inverter. A current sourced inverter will reduce the ripple on the input of the DC/DC-converter because of the placing of a coil in the rail feeding energy to the switches. Actually the coil could have been inserted in the DC-bus on the DC/AC-inverter, but this would give more ripple on the current fed from the source. Therefore, a current sourced DC/DC-converter is preferred. Further, capacitors of lower ratings can be used on the input of the DC/DC-converter. The voltage sourced inverter on the second module is preferred because it enables an easy connection of multiple DC/DC modules to the DC/AC module.
Thus, selecting an interface between the first and the second module after the rectifier gives a well-defined point of connection for multiple DC/DC-converters to be connected to one and the same DC-bus in the inverter module.
If the first module uses a power module, an H-bridge of switches and a full bridge rectifier can be integrated into the same. housing of the power module.
This gives a high degree of integration and component density, which further enables the use of only one cooling module instead of two.
Preferably, two or more first modules are connected to the second module. This means that one can connect two solar cells, or one solar cell and one fuel cell to the same inverter and obtain either higher power input or redundancy in the supply of energy.
The use of independent controllers means that each DC/DC module is able to perform a suppression of ripple generated by the delivery of power to a single phase grid. This ripple acts back into the DC/DC-converter, but can be compensated in that an actual voltage amplitude of a ripple on the DC voltage of the second module, or an actual phase angle of a ripple on the power delivered to the grid, is measured and converted into a duty cycle compensation value which is added to a duty cycle of the switches of the first module. In this way, the ripple simply stays in the DC-bus capacitor of the DC/AC-inverter module. Information about the angle value or the voltage amplitude is transferred via the communication bus. The suppression of ripple improves the electrical efficiency of the power converter.
It is preferred, that the first and second controller are galvanically separated from each other. Hereby a total galvanic separation of the DC/DC-converter module and the DC/AC-inverter module is reached. The galvanically separated bus typically communicates via optocouplers.
A man-machine interface module can be connected to the serial communication bus, and be used for parametrisation of the power converter.
A snubber circuit can be connected in front of the inverter of the DC/DC-module. Using a passive snubber for preventing the power switches against overvoltages from the transformer is a well known measure, but by feeding back the energy to the DC-input of the DC/DC-converter the overall effeciency of the power converter is increased.
Advantageously, an active snubber is used. Connecting a switch to a snubber capacitor allows the first controller to control the flow of energy, which has the advantage that a further raise in the efficiency is obtained.
The electrical efficiency of the DC/DC-converter is increased, if the voltage across said snubber capacitor is a function of the voltage supplied from the green power unit. The first controller calculates a voltage set point from the green power unit voltage and the switch is modulated to induce a voltage across the capacitor which voltage corresponds to the voltage set point.
The DC/DC-converter is preferably started in a discontinuous current mode during which a duty cycle is increased by a duty cycle generator until a limit value is reached, whereafter the DC/DC-converter is operated on this limit value for a time period. This softstart enables the use of a solar cell also at sun rise or at sun set, because the solar cell normally will collapse if the DC/DC-converter is allowed to draw more current from the cell than it is able to deliver. To avoid collapse, the DC/DC-converter is driven at exactly the limit value which matches the lower current which the solar cell can provide at sun rise and sun set.
An H-bridge of switches in the DC/DC-converter is preferred if the green power unit supplies a higher voltage which is the case for a solar cell. Thus there is no need for high voltage ratings of the power switches in the H-bridge, and the transformer can be designed smaller.
A current sensor, preferably a shunt, is inserted in the minus conductor of the inverters in the DC/DC-converter and the DC/AC-inverters respectively, and the current signals are led to the first and second controller respectively. Hereby only one shunt is used per inverter as opposed to solutions where the shunt is inserted in each leg of the lower switches.
Instead of an H-bridge, the DC/DC-converter can be designed with a push pull stage. Push pull converters are preferred if the green power unit supplies low voltage, which is e.g. the case with fuel cells.
The push pull stage of the DC/DC-converter is preferably started in a discontinuous current mode during which a duty cycle is increased by a duty cycle generator until a limit value is reached, whereafter the DC/DC-converter enters a continuous current mode in which the duty cycle generator freely generates the duty cycle to regulate the current in the DC/DC-converter. Hereby, the power converter can be started without large inrush currents. The value of the duty cycle is forcingly raised slowly during a first period, and varying freely during a second period. Thus, the inrush current is reduced in the discontinuous mode of the converter.
Preferably, the limit value is a minimum simultaneous conduction time or minimum overlap in duty cycle of the switches in the DC/DC-converter.
More preferably, after reaching the limit value the duty cycle controller keeps the duty cycle approximately constant at a minimum overlap for a period of time during a transition zone between the discontinuous current mode and the continuous current mode.
When using a push pull converter, an optimum working point of the green power unit can be reached with a search method which is characterized in that a current reference for the current of the DC-coil of the push pull converter is regulated stepwise until an optimum operating voltage of the green power unit is reached. The optimum operating voltage gives the highest output power.
The inverter of the second module is preferably controlled to emulate an ohmic resistor towards the grid. This gives low harmonic distortion. This type of control is implemented with the second controller controlling the inverter of the second module by means of two control loops, a current control loop regulating the shape of current supplied to the grid similar to the shape of the grid voltage, and a voltage control loop regulating the amplitude of the current supplied to the grid.
Preferably, the first controller is connected to minus of the DC/DC-converter, and the second controller is connected to minus of the DC/AC-inverter. This simplifies the gate drives, and no extra power supplies and optoisolators are needed.
An LCL filter is inserted between the output of the second module and the grid. This filter smoothes the current and voltage delivered to the grid. Oscillations may occur, but these can be dampened by adding an ohmic resistor in parallel with the coil next to the grid.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained in details by means of the Figures, where
FIG. 1 shows paralleled DC/DC modules and one DC/AC module according to the invention connected to a common DC-bus.
FIG. 2 shows a modularized power converter according to the invention with an H-bridge DC/DC-converter.
FIG. 3 is a diagram according to the invention of a grid connected DC/AC inverter with a full bridge DC/DC-converter.
FIG. 4 shows the waveforms of the circuit in FIG. 3 .
FIG. 5 is an elaboration of FIG. 3 , now incorporating an active clamp in the DC/DC module.
FIG. 6 shows the waveforms of the circuit in FIG. 5 .
FIG. 7 is a diagram of a full bridge DC/DC-converter with an active snubber circuit.
FIG. 8 is a diagram according to the invention of a grid connected inverter with a push-pull DC/DC-converter.
FIG. 9 shows the transfer characteristic of an analog PWM generator used in the push-pull DC/DC-converter.
FIG. 10 shows the relation between duty cycle and current and voltage mode in the push-pull converter.
FIG. 11 illustrates the pulse sequence generated by a microprocessor in voltage mode of the push pull converter.
FIG. 12 shows the ideal characteristic of a load for a snubber circuit and its practical implementation for use in a push pull converter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows how a DC/DC-module A is connected to a DC-bus 3 , which is common to several other DC/DC-converters. They are all feeding energy into the DC-bus, and DC/AC-inverter B taps the DC-bus and converts the energy into a grid voltage and grid frequency. A filter 13 as described later in this application may be used. Such filter is also a module, as shown in FIG. 2 . The modules A and B are connected to each other via an interface 4 shown on FIG. 2 . Such interface is preferably an easy insertion interface. The modules communicate via a serial bus 5 . The CAN bus is preferred. The control of the system consisting of modules A and B is divided into two control circuits 1 and 2 galvanically isolated from each other. In this embodiment, a micro controller regulates the DC/DC-converter, and a Digital Signal Processor regulates the DC/AC-inverter. The DC/DC-converter and controller are placed on a first module A and AC/DC-inverter and controller are placed on a second module B. In this way, a modularized system is achieved, which makes customisation easy. Thus, in the case where the energy cell is not a photovoltaic cell but a fuel cell, module A is replaced by module A′ or A″ comprising a control and a DC/DC-converter suited for a fuel cell, which supplies a lower voltage than the photovoltaic cell. Or, alternatively, the inverter module B can be replaced. Also, the Man-Machine Interface M is an intelligent module with communication capability.
In summary, by dividing the green power converter into modules comprising a DC/DC-converter and a DC/AC-inverter module respectively, and adding control intelligence to each module, the possibility of a modular system is opened. The converter and the inverter can be designed separately, and altering the DC/DC-converter topology can be done without changing the inverter topology. Thus, the green power converter is flexible on system level as well as on a converter technology level.
Continuing on FIG. 2 , the DC/DC-converter controller 1 is connected to minus Ml of the converter, i.e. to minus of the green cell P. This simplifies the gate drives and no extra power supplies and optoisolators are needed. Current measurement may be made with a resistor RM 1 inserted serially in the power leg, but a shunt in the minus is preferred. Further, input reference signals from the outside world will advantageously be on low potential.
Also, the inverter controller 2 is connected to minus M 2 of the DC/AC-inverter. This simplifies gatedrives and supply for these, since bootstrap supply based gatedrive IC's can be used. Since the inverter voltage loop always operates at fixed voltage reference (375 V) an external reference is not needed for this subcircuit. Startup or shut-down signals between the two circuits, i.e. the first and the second controller, may easily be transferred via inexpensive optocouplers. This can be done by means of the serial bus.
The modular concept enables the distribution of intelligence. Instead of having one master controlling all modules, each module A, A′, A″, B or M has its own controller and communication interface. While module A is designed for photovoltaic, module A′ and A″ may be designed for fuel cells. A, A′ and A″ can at the same time be connected to inverter module B.
Different topologies can be used in the power converter, where it must be observed that the high frequency ripple of the green power cell current should be small and that the cost should be minimized.
As mentioned, the power converter should provide galvanic isolation between the green cell terminals and the utility grid. If the green cell is a fuel cell, it operates in the voltage range 25-45 VDC. Having a grid voltage of 230 Vrms, the power converter must perform two tasks: the power must be inverted and the voltage must be amplified. These tasks could either be done by connecting an inverter to the fuel cell followed by a 50 Hz transformer (AC-AC voltage gain) or by connecting a switch mode DC/DC-converter to the fuel cell (DC/DC voltage gain) followed by a grid connected DC/AC-inverter. A DC/DC voltage gain (switch mode DC/DC-converter) is preferred in order to limit physical size and the cost of the system. Hence, a system with a switch mode DC/DC-converter followed by a grid connected DC/AC-inverter is selected. Using a grid connected DC/AC-inverter makes the power converter system more modular as the DC/DC-converter can be replaced according to the application and a standard inverter system can be employed. Basically, the DC/DC-converter can be a current sourced or a voltage sourced converter. A current sourced DC/DC-converter requires less input filtering in order to minimize the high frequency current ripple drawn by the power converter because an inductor is placed at the input. Thus, a current sourced DC/DC-converter is preferred. The two most attractive DC/DC-converter topologies are the the full-bridge converter and the push pull converter. Both topologies exhibit a high efficiency capability. They are well known technologies and have a good utillisation of the magnetics (bidirectional magnetization of the transformer) and of the power switches. Both will be detailed later.
The three most attractive single phase DC/AC-inverter topologies are the full-bridge inverter, the half-bridge inverter and the push-pull inverter. A standard H-bridge inverter is preferred due to the good utilization of the materials and a high efficiency capability.
In the following, a current sourced full bridge DC/DC-converter with a full bridge DC/AC-inverter will be described with reference to FIG. 3 .
The fundamental operation of the dual full bridge topology is the following: the voltage delivered by the fuel cell 15 is inverted into a high frequency voltage in the first DC/AC-inverter 18 . This voltage is fed into a high frequency transformer 10 . The transformer secondary is connected to a rectifier 8 with a filter capacitor 9 , and thereby a DC/DC-converter is achieved. The voltage delivered by the DC/DC-converter is fed into the DC/AC-inverter 14 , whose main task is to generate a sinusoidal grid current. The DC/DC-converter is controlled in such a way, that the current delivered by the fuel cell is constant at the desired value. This may cause the voltage of the DC-link between the rectifier and DC/AC-inverter to rise beyond a certain limit. Therefore, the DC/AC-inverter 14 is controlled to lower the DC-link voltage, meanwhile it also generates the grid current. This means that the reference for the peak grid current is dictated by the maximum DC-link voltage.
The advantage of such two-stage inverters is that the energy storage capacitors may be reduced in size when compared with the single step topologies. It may also be easier to obtain a controller for these inverters, because they are decoupled by the energy storage. Moreover, a high frequency transformer 10 is used, which is much smaller than a 50 Hz transformer, for galvanic isolation and stepping up the fuel cell voltage.
The full bridge current source—full bridge voltage source power converter of FIG. 3 is used in the low power region. A major advantage is that the converter is based on the principle of boost operation, which means that it is possible to step up the voltage without the transformer. Another advantage is that the diodes in the rectifier are commutated by a current, and no reverse recovery currents are therefore generated. Probably the only disadvantage associated with this converter is the inherent presence of voltage spikes across the switches. These spikes originate from the transformer current and leakage inductance. In practice, the leakage inductance may be held small by making a proper transformer design, but not small enough in order to be able to omit a snubber.
FIG. 4 shows the control signals and the waveforms of the DC/DC-converter:
[t 0 -t 1 ] All four switches (q 1 -q 4 ) are closed, causing the current i LFC through inductor 6 to rise linearily by means of the cell voltage. The cell voltage is clamped by the input capacitor 16 , so only a small amount of ripple is present. The output is supplied by the stored energy in capacitor 9 . [t 1 -t 2 ] The transistors q 3 and q 2 turn off at time t 1 . The current stored in the input inductor 6 is then forced through the transformer 10 , and the inductor is discharged by means of the cell voltage and the reflected DC-link voltage. The transformer current i a is negative, and feeds the output capacitor 9 through the rectifier 8 . [t 2 -t 3 ] Transistors q 3 and q 2 turn on again at time t 2 , and the input inductor is charged again. [t 3 -t 4 ] q 3 and q 4 turn off, and the transformer current is now positive.
The voltage spike across the switches 7 may be determined in terms of their output capacitances C oss and the leakage inductance. The spike amplitude may be decomposed into two terms, one from the reflecting DC-link voltage, and the other from the voltage generated by the leakage inductance. The current delivered by the leakage inductance is poorly damped, and reaches a peak value of two times the fuel cell inductor current.
In order to reduce the turn-off voltage spikes over the switches, it is necessary to reduce the transformer leakage inductance. If this not is possible, a snubber circuit must be added in parallel with the DC-link.
Supplying power to the a single-phase grid gives 100 Hz or 120 Hz pulsations on the output of the power converter. The pulsations act back into the DC/AC-module, and causes ripple. This ripple is also reflected back to the input and hence the operating point moves away from the optimum cell voltage. This lowers the overall efficiency of the power converter. However, this can be compensated by measuring the actual phase value of the power delivered to the grid, converting the phase value into a duty cycle compensation value, and adding this compensation value to the normal regulation duty cycle. An upward going motion on the power curve on the grid is counteracted by inducing a positive going motion in the voltage delivered by the fuel cell. The duty cycle compensation value is a feed forward contribution which can be negative or positive, and is calculated by controller 1 . Instead of measuring the power, measurement of the actual phase value of the grid voltage or the actual voltage value of the ripple in the DC-link is possible.
An active clamped current source—voltage source converter is depicted in FIG. 5 , and the key waveforms in FIG. 6 . This active clamp is a good compromise between complexity, reliability and efficiency. The advantage of this topology is that a passive snubber is replaced with an active one, which increases the overall effciency when compared with the converter of FIG. 3 . The active clamp consists of a switch 20 and a snubber capacitor 21 , and is switching on during zero current in the inductor 6 , and therefore only turn off losses may appear together with the forward voltage drop of the switch.
The mode of operation is shown in FIG. 6 :
[t 0 -t 1 ] As in the CS-VS converter. [t 1 -t 2 ] When transistors q 3 and q 2 turn off, the leakage current is discharged into the snubber capacitor 21 through the internal body diode of the snubber switch 20 . This causes the voltage across the switches to raise slowly. The snubber switch 20 (q C ) is then turned on before the snubber current becomes negative, and zero current switching is in this way achieved. The capacitor current is now negative, causing the voltage to drop toward the reflected voltage from the DC-link. [t 2 -t 3 ] As in the CS-VS converter. [t 3 -t 4 ] q 1 and q 4 turns off.
The ripple current in coil 6 and the ripple voltage across capacitor 16 is equal to the ones given for the CS-VS converter.
Starting the H-bridge is alleviated by the snubber, which enables the controller 1 to keep the input current from the fuel cell at a low value during e.g. low capacity in the fuel cell. Hereby, the cell is protected against overload.
FIG. 7 illustrates a current fed DC/DC-converter provided with an active snubber circuit 25 . The DC/DC-converter comprises a power module 26 , which incorporates the inverter bridge 27 , the rectifier 28 and a shunt 29 . Thus inverter and rectifier are integrated into the same housing. In order to obtain a fully galvanic isolation between rectifier and inverter inside the power module 26 , a separating channel 35 is built into the power module. This channel has a width of 3 mm. The controller 1 controls the snubber circuit 25 and inverter 27 , but details about control of the latter is omitted here. The snubber circuit consist of a snubber capacitor 30 , which through diode 31 stores energy delivered from transients generated by switchings of the inverter. The stored energy is fed to the input of the DC/DC-converter, hereby raising the efficiency. Controller 1 pulse width modulates through galvanically isolated driver 32 switch 33 to draw current from capacitor 30 through resistor 34 and snubber coil 36 . A voltage set point of the snubber capacitor 30 is calculated by the controller 1 on the basis of the voltage of the fuel cell inputted to the controller, and the controller modulates switch 33 to obtain a voltage across capacitor 30 which corresponds to said voltage set point. The calculated voltage set point maximises the efficiency of the DC/DC-converter, and the set point is preferably kept constant for a fuel cell voltage between 0-50V, and raised to 70V for cell voltages above 50V. The set point can also be calculated as a function of the fuel cell current or the DC-link voltage of the second module, but in general the set point voltage must be higher than the maximum voltage from the fuel cell. Because of the high frequency PWM switching, the snubber coil 36 can be limited in size and still reduce the ripple of the current fed to the input. Thus, the amount of snubber energy fed back to the DC-input is controllable.
FIG. 8 shows a power converter which instead of the full bridge inverter in the DC/DC-converter uses a current-fed push-pull DC/DC-converter, which is basically an isolated boost converter consisting of DC-coil 40 , power switch 42 , diode 43 and capacitor 44 . The steady state voltage transfer function for continuous conduction mode is:
V DC = n 1 - D L · V FC ( 1 )
where D L is the duty cycle seen from the inductor, n is the turns ratio on the transformer 10 , V FC is the voltage from the fuel cell and V DC the DC bus voltage. Through inspection of the current waveforms and on/off-times of the power switches, the following coherence between inductor duty cycle D L and switch duty cycle D q can be established:
D
q
=
D
L
+
1
2
(
2
)
It appears that the frequency seen from the inductor is twice the switching frequency of the power switches (i.e. f L =2f q ). Keeping the duty cycle D≧0.5 means current mode operation. In this embodiment the controller 1 comprises a microprocessor 1 and a PWM modulator (of the type SG3525) 46 . This modulator is not ideal and an offset in the inductor (overlapping) duty cycle is present in the system which can be seen from FIG. 9 . The PWM modulator chip 46 is designed for driving the two transistors 41 , 42 in push-pull configuration. The span of the control voltage is given in the design catalog 0-5V, but continuous variation of the duty cycle is provided only between 0.9 V-3.6V. From 3.3 V to 5V, the duty cycle remains unchanged (about 47%), while below 0.9 V, the duty cycle of the pulses changes suddenly from about 5% to zero (no pulses). The input to the PWM modulator is the control voltage that gives a duty cycle according to FIG. 9 . Thus, the minimum inductor duty cycle is 5%. This gives rise to a high startup current which may trigger the over-current protection and the system can therefore be difficult to start. Due to the duty cycle offset a smooth startup procedure has been developed. The PWM modulator chip 46 is designed to drive voltage mode push pull converters. Initially the converter is started in voltage mode (D<0.5) and the switch duty cycle is ramped up from zero to one half. When the switch duty cycle reaches 0.5 the microprocessor is allowed to operate. When the push-pull converter operates in voltage mode, the microprocessor provides gate signals to the MOSFETs 41 , 42 , and when the push-pull converter operates in current mode the PWM modulator 46 provides the gate signals. The microprocessor dictates the operating mode of the push-pull converter a ‘select pulses’ signal ( FIG. 10 ) is used to select the source of the gate signals. In addition, a ‘force minimum PWM ref’ ( FIG. 10 ) is used to force the PWM reference of the analog control to be minimal during the transition from voltage mode to current mode. When the push-pull converter has entered current mode operation the analog control IC is released. In the following, the push-pull controller will be further elaborated.
The control of the push pull converter uses an analog PI controller to deliver a command signal to the dedicated dual PWM generator 46 . In conjunction to this analog control, a logic control unit implemented in a Programmable Logic Device (PLD, not shown) is employed in order to provide the necessary protections and to improve the flexibility, such as the controlled soft start-up of the converter in voltage mode, driven by the micro processor.
The control system for the push pull converter has the following requirements:
to accept reference signal from the microprocessor to include a PI controller for the inductor current to convert the output signal from the PI current controller into pulses for the push pull transistors to include auxiliary circuits to provide soft start-up of the converter, antiwindup
In order to avoid over currents during start-up, caused by the unmagnetized transformer 10 or the saturation of the analog PI controller which may cause overshooting of the control signal, auxiliary circuits should be used. These consist of:
an anti-windup circuit on both upper (4.7 V) and lower (0.9 V) limit of the PI controller output, which gives the possibility to have continuous pulse generation. a controllable minimum switch overlap duty cycle circuit, which gives the possibility to force the push-pull converter to work with minimum switch overlap duty cycle, meaning minimum power in DC-link, commanded from the microprocessor when needed; extra functional logic found in the PLD, to allow direct command of the push-pull transistors from the microprocessor when needed. few digital outputs from the microprocessor controlled by software.
All these subcircuits form a hybrid regulator (analog& digital), able to react very fast (characteristic for analog control) in order to control the current in the inductor 40 , and also providing flexibility (characteristic for digital control) in order to solve easily all the required tasks needed by the inventive power converter.
As mentioned, in order to be able to start-up the push-pull converter without overcurrents, it is necessary to ramp-up the duty cycle in voltage mode from zero duty cycle to 50% and beyond, when this goes in current mode, until it reaches the minimum limit of the switch overlap duty cycle given by the analog modulator. In this way, any shock is eliminated. However, due to the presence of the inductance in the circuit, during voltage mode much energy is produced which flows into a snubber circuit. Therefore, this ramping should be completed fast, and it should be verified that the snubber circuit is able to withstand the transient without exceeding the safe operation voltage level.
Investigations to implement the above start-up principle exclusively by analog circuitry gave no result, therefore It has been chosen to let the microprocessor produce the two desired controllable duty cycle 180° shifted pulses, by using two digital outputs driven by a capture-compare unit. To be able to control directly the gate driver by these signals, another signal to select the source (analog PWM-modulator or microprocessor) should be used. In FIG. 11 the principle of generation of the pulses is shown.
Timer T 0 is running continuously with a frequency very close to the analog PWM generator. Digital outputs P 2 . 8 and P 2 . 9 are programmed to work in a mode, which is commanded by compare registers CC 8 and CC 9 in the microprocessor, which are both assigned to timer T 0 . The pulses are not equally placed because of software simplicity, but also, because it is possible to reduce the energy which flows in the snubber circuit when one firing pulse is immediately following a previous firing pulse in the push pull converter. Also, it is easy to overlap the pulses, by making CC 9 smaller than CC 8 , and performing smoothly the transition from voltage mode to current mode. In order to eliminate overshoots of the analog control, when the converter is started, or when the command is switched back to the analog PWM modulator, a circuit to force the Pi controller output, being controlled from the microprocessor by a digital output, is necessary.
This circuit should force the output of the PI controller to be higher than 3.6V, which corresponds to the minimum switch overlap duty cycle when commanded from microprocessor, and to ensure a smooth transition to steady state when command is released.
In FIG. 10 the evolution of the control signals during the start-up is shown. The converter starts driven by pulses produced by the microprocessor, with a variable duty cycle, ramping to a value, which corresponds to the minimum switch overlapping duty cycle, specific to the analog controller. Therefore, at the end of the ramping, the converter goes smoothly from voltage mode to current mode. All this time, the output of the PI controller is clamped to a value, which applied to the PWM generator, produces the same duty cycle synthesized by the microprocessor at the end of the ramp. Therefore, when the source of the pulses is switched from microprocessor to the analog PWM generator, no transient should appear. Only after the output of the PI controller is softly released, the duty cycle of the switches may vary freely, in order to regulate the inductor current at the desired level.
Practical tests on the start up procedure have shown, that though an inrush current is still present, it is reduced and far below the over current protection limit, so a smooth startup is achieved.
The transformer 10 in FIG. 8 is the key component when designing the current fed push-pull DC/DC-converter due to the demand for a high efficiency. A high efficiency demands for a good magnetic coupling between the two primary windings in order to decrease the power dissipated in a snubber circuit. The primary windings are the most important part in the transformer design due to the high coupling requirement and the high current through these windings. Different types of magnetic designs were tested and a transformer with copper foil for the primary windings gave the best coupling between the two primary windings. This solution also gave the best efficiency since the foil windings provided a good utilization of the winding area and thereby allowing a lower current density in the transformer.
From FIG. 8 it is seen, that a single phase H-bridge inverter 48 is used as DC/AC-inverter, and an LCL filter 47 is placed at the output in order to achieve a high filtering of the inverter output current. The aim of the inverter control is to load the DC-link capacitor 44 in order to maintain the average of the DC-link voltage at the desired value V DC,ref . The current impressed into the utility grid must comply with IEC-61000-3-2. In addition, the inverter must be fast enough to protect the DC-link and the semiconductors from over-voltages due to spikes from the power source. In order to fulfill the low harmonic regulation IEC 61000-3-2, the inverter is controlled to emulate a resistor R e . Hence, the grid current waveform must be a scalar of the voltage waveform: R e =v g /i g . The control is done digitally.
Besides the harmonic content of the line current, two performance indexes axe used: % THD I and PF. With perfect resistor emulation and with a background distorted line voltage, the line current % THD I will be the same as the line voltage distortion % THD V . The power factor will be unity for perfect resistor emulation and regardless of background distortion.
In order to obtain a high power factor and a low % THD I the current controller must be able to track not only the fundamental grid frequency at 50 Hz but also the distortion components. The switching frequency and the sampling frequency is 10 kHz.
The inverter control consists of two control loops. The inner control loop shapes the grid current to a wave shape proportional to the grid voltage. The outer control loop controls the amplitude of the grid current in order to maintain the average of the DC-voltage equal to the reference.
Hence, the inverter emulates a resistance by means of two cascaded loops. The grid and the inductor current are not sinusoidal because the DC-link voltage control loop distorts the current reference, which the current controller follows (cf. the multiplier in FIG. 8 ). For that reason, the sampling time of the DC-link voltage controller should be equal to 20 ms. In this way, the DC-current injection to the grid is reduced to a minimum. It has been found, that a feed forward of the grid voltage cancels the influence from the grid voltage (at low frequencies). However, the feed-forward loop has less attennuation at higher frequencies and is thus not immune towards high frequency noise. Therefore a low-pass filtering of the feed forward loop should be used in order to avoid noise problems. Design of the current controller is done based on the third order LCL transfer functions given with the LCL filter yet to be described.
By using two loops, it becomes in this way possible to attach more than one power source to the same inverter-stage.
As demonstrated in the previous section, the current controller controls the wave shape of the line current. The DC-link voltage is controlled by varying the amplitude of the grid current i g . The DC-link voltage must be maintained on a level above the peak of the line voltage in order to be able to maintain controllability of the inverter. Regarding the bandwidth of the voltage controller there is a trade off between grid current reference distortion and DC-link overvoltage protection: The grid current reference is basically formed as the DC-link current reference multiplied by the measured grid voltage which means that the grid current reference will only be a scalar replica of the grid voltage in the case of a constant DC-link current reference. This requires a very slow DC-link control. In terms of DC voltage protection the dc voltage controller must be fast enough to avoid hazardous operation. Actually hazardous operation will not be reached due to the hardware protection, but the DC-link controller must be fast enough to avoid triggering the hardware protection which shuts down the system (The maximum DC-link voltage allowed by the hardware is 420 V). Setting again the damping ratio to ξ=1/√2 and taking the slow dynamic operational requirements from the fuel cell system into account the bandwidth of the voltage controller can be chosen very low around f b,dc =2-5 Hz.
The dynamics of the current loop can be neglected during design of the voltage controller since the current loop bandwidth is app. 250 times higher than the outer voltage loop bandwidth. In addition the push-pull current control bandwidth is also much higher than the voltage controller bandwidth. For perfect resistor emulation and with sinusoidal grid voltage the power balance gives:
i
dc
,
tg
=
i
^
g
v
^
g
2
v
dc
,
tg
(
6
)
Thus in steady state there is a simple relation between i DC and i g . A PI controller is selected in order to achieve a DC voltage error at zero and to have a more smooth DC current reference less sensitive to noise.
The amplitude of the line current or the value of the emulated resistance is controlled by the outer voltages loop. Since the line current-in the ideal case-is sinusoidal, the power delivered to the grid is a pulsating power at twice the line frequency and the power ripple is 100%.
Referring again to FIG. 8 , the areas enclosed by the hatched lines are implemented in two microprocessors 45 , 49 and hence, the control of the system is a mixture of digital and analog control. The fuel cell provides a reference for the fuel cell voltage V ref and the power converter then controls the current reference in order to achieve the correct fuel cell voltage as the fuel cell follows a linear characteristic in a (v FC ,i FC ) coordinate system. Since the dynamics of the fuel cell are very slow compared to the power converter capability, a simple and slow search algorithm is implemented for the voltage control. The voltage control steps the current reference in accordance with the mentioned linear characteristic towards the desired fuel cell voltage. It should be noted that the search algorithm does not need any information on the internal fuel cell resistance but only information of its maximum current and the operating voltage range of the fuel cell to avoid overloading the fuel cell. An analog PI-controller 50 then controls the inductor current in accordance with the reference given by the microprocessor through a D/A-converter.
In the following, the snubber circuit of the push pull converter will be dealt with in detail by reference to FIG. 8 . The snubber consists of resistor 51 , capacitor 52 and diodes 53 and 54 . The energy, which flows in the snubber circuit capacitor during normal operation, depends only on the leakage inductance of each primary winding, and is dependent on load condition.
As a high internal resistance characterizes the characteristic of the fuel cell, it is expected that the power flow in the snubber circuit will increase drastically, when the operating point is getting close to the maximum power. This depends on the leakage inductance of the half split primary winding of the transformer 10 (L trafo ), on the value of the switching frequency f sw and on the current, which is braked.
P
clamp
=
2
·
f
sw
·
L
trafo
2
·
(
I
FC
+
Δ
I
ripp
2
)
2
2
(
3
)
Requirements for the adaptive load in the snubber circuit are to limit the voltage level in order to provide safe operation for the switches and also to maintain a higher voltage in the snubber capacitor 52 , which will force a faster turn-off and therefore lower switching losses and also keep the snubber circuit blocked from working as a rectifer when the voltage across the primary reflects the conduction of the diode rectifier in the secondary winding. Therefore, the voltage in the snubber circuit should be maintained high in a wide range of power levels. Experiments on the transformers are carried out by adapting the value of the load in order to maintain the voltage in the snubber capacitor at a desired value. The load consists in a variable resistor to feed back energy to the fuel cell, with a maximum value of 8.8 kΩ, which may be decreased in order to increase consumption.
An ideal characteristic of the load for the snubber circuit is presented in FIG. 12 and the practical implementation is depicted in the right side.
The meaning of the elements in the circuit: The zener diode is necessary to ensure that the load will work only for voltage levels higher than the reflected voltage from the secondary side and below the maximum allowable voltage. At low power, it is necessary to by-pass the zener diode with a parallel resistor Rp, in order to discharge the clamp capacitor, as well as to decrease the power dissipation in the zener diode at higher voltage drop level.
A series resistance Rs is necessary to adapt the external characteristic of the fuel cell. Because the energy from this load applied to the snubber circuit is wasted, a circuit could be introduced which uses a part of this energy to feed a small fan for cooling of the power transformer of the push pull converter. A comparator senses when the amount of energy in the snubber circuit, which is proportional to the fuel cell current, increases, which means that the power processed by the push pull converter increases and losses in the transformer increase. Then the fan is supplied and starts cooling the transformer. The overall effciency of the push pull converter is not affected.
Turning again to FIG. 8 , the LCL filter 47 will now be discussed.
In order to maintain a sinusoidal grid current with low harmonic distortion and a high power factor, the inverter is controlled to emulate a negative resistance towards the grid. The size of the emulated resistor is determined by the DC-link voltage controller, which tries to maintain a constant DC-link voltage. This is however not possible, while the power into the DC-link is constant and the power out of the DC-link is a second powered sinusoidal with an amplitude of two times the average power.
For that reason a ripple is present. In order to lower the transmitted high frequency current ripple, due to the operation of the inverter, an LCL filter is inserted between the grid and the inverter. The LCL filter may be regarded as an inductor for frequencies slightly below the resonant frequency of the filter; hence the control of the filter becomes easy. On the other side, the z-plane poles for the filter, even with parasitic resistances, lie close to the border of the unit-circle. Adding a resistance in parallel with the outer inductor Z g in the LCL filter shows to improve the stability at the cost of a slightly higher loss. A 1 kW power converter was designed and implemented. The result shows that the LCL filter is stable when the damping-resistor is added. The total harmonic current distortion was measured below 4.0 and the power factor is better than 0.99 for an input power above 300 W.
The LCL filter of FIG. 8 has the following components in the s-domain:
{ Z i = R i + L i s Z g = R g + L g s Zo = 1 / Cs ( 4 )
where L i has a value of 4.0 mH, R i 400 mΩ, L g 850 μH, R g 180 mΩ and C 2.2 μF. In the general case all passive elements are treated as impedances.
Transfer functions have been derived for the LCL filter for the purpose of current control. The transfer functions link the two filter terminal voltages (grid voltage and inverter voltage) to the corresponding inductor currents.
A comparison between the established third order functions and an inductive equivalent shows that below the resonance frequency a single inductor-resistor equivalent is an adequate approximation of the inverter voltage to inverter current but in order to describe/analyse stability the LR circuit is not adequate near the resonance frequency of the LCL filter.
Looking at the amplitude responses it has been found, that damping of the filter can be utilized in order to improve the stability of the current loop. As mentioned a resistor in parallel with the inductor Zg ( FIG. 8 ) towards the grid is added. In the ideal case where parasitic conducting resistors are omitted, the impedance Zg can be written as follows:
Z g = L g s ❘ ❘ R d = L g sR d L g s + R d ( 5 )
where Rd is the damping resistor. Damping is introduced of the open loop poles at unity proportional gain. Of course as the damping resistor increases the poles and zeros move towards undamped positions. It can be observed that the open loop poles without damping are placed very close to the border of stability. One might choose a damping resistor with a low value. But since the power dissipation in the damping resistor increases and filter attenuation decreases, as the resistor value decreases, there exists a trade off between stability, efficiency and filter attennuation. A damping resistor of Rd=38Ω has been chosen.
While the present invention has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this invention may be made without departing from the spirit and scope of the present invention.
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A power converter for converting energy from a green power unit as e.g. a solar cell into energy fed into the commercial grid is described. The object is to provide a versatile modularized power converter with eased access to control of the power switches. Another object is to improve the electrical efficiency. This is achieved by using an independent controller on a DC/DC module and an independent controller on a DC/AC module, whereby the two independent controllers communicate with each other and the outside world by means of a communication bus. Further, the DC/DC module of the power converter comprises a transformer which transfers energy from the DC/DC module to the DC/AC module. This design enables independent control of the modules and eases controllability of the power switches in order to suppress retroaction from pulsations generated on the mains when supplying energy to a single phase grid. Hereby the electrical efficiency of the power converter is increased. Also, an active snubber circuit is described which further increase the efficiency.
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FIELD OF THE INVENTION AND RELATED ART
The present invention relates to a process for distributing and uniformly dispersing a short fibrous material onto a continuously-travelling sheet-like shaped material of any thickness inclusive of film, sheet, mat and plate (which will be inclusively referred to as "sheet" hereinafter), and an apparatus therefor.
For example, a resinous sheet having electroconductive fiber uniformly dispersed on the surface thereof, which has been produced by using a resinous sheet as an example of the sheet and conductive fiber as an example of the fiber, may be formed into an electromagnetic wave-shielding sheet or a conductive molding material by fixing the fibers on the surface into the resinous matrix of the sheet while the resinous sheet is being transferred.
As methods for incorporating a fibrous material into a resinous material in the production of the above-mentioned conductive film or conductive synthetic resin shaped material as electronic materials illustrated as an example of application of the present invention, in general, the following various processes have hitherto been adopted:
(1) A process comprising mixing conductive fiber with a molten thermoplastic syntheric resin and forming the mixture into a sheet or film by an extruder.
(2) A process wherein a conductive fiber is mixed with a thermoplastic synthetic resin fiber (polyolefinic synthetic pulp) and/or vegetable fiber (wood pulp) in a dispersing medium (in a wet system); the mixture is subjected to a paper-making process to form a blend paper; and the paper is dried and hot-pressed to produce an electroconductive film or sheet (Japanese Laid-Open Patent Application Nos. 26597/1984 and 213730/1984 and Japanese Patent Application No. 239561/1984).
(3) A process comprising placing and hot-pressing a woven fabric of, e.g., conductive fiber, onto a thermoplastic synthetic resin film or sheet to produce a film or sheet.
(4) A process which comprises dropping and distributing conductive fiber onto a sheet of thermoplastic resin alone produced by melt extruding, while cutting the conductive fiber into slivers and subjecting them to hot-pressing at a temperature higher than a softening point of the thermoplastic resin (Japanese Laid-Open Patent Application No. 217345/1983).
(5) A process for depositing short fiber by suction onto a continuously travelling gas-permeable sheet while disintegrating the short fiber by using a compressed air medium (Japanese Laid-Open Patent Application Nos. 49928/1984 and 49929/1984).
However, the above-mentioned processes are respectively accompanied by the following problems.
In the process (1), the severance of the fiber occurs during mixing the thermoplatic synthetic resin with the conductive fiber and further, the orientation of the fiber is caused by the melt extrusion, resulting in a difficulty in forming a uniform film or sheet having a desired conductivity.
In the process (2), the energy for drying the wet blended paper is excessively consumed, and unevenness in thickness during paper-making reaches as large as a factor of 4 to 5 and hence, it is not easy to provide a uniform film.
In the process (3), the use of the woven fabric causes the conductive fiber to be used in an amount larger than required, thus being uneconomical.
In the process (4), the slivers are dropped and dispersed, but even cut fibers are entangled during dropping to become rebundled and therefore, the uniform dispersion thereof on the resinous sheet is not ensured. On the other hand, the unevenness in distribution is not remarkable when the amount of conductive fiber per unit area (amount of fiber distributed) in the conductive sheet is larger. Because it is desirable, however, that the product sheet is transparent when used as a packaging paper so that the content is seen therethrough, the amount per unit area should be controlled to a smaller level of 300 to 400 g/m 2 or less. In such a case, nothing is solved with respect to the problem of the remarkable unevenness in distribution. Particularly, in producing a wider composite resinous sheet, the uniform distribution of fiber in a smaller amount is significantly required.
In the process (5), not only a fiber distribution face on which the fiber is distributed is limited to that given by a gas-permeable sheet which permits air as a medium used for disintegrating and transferring the fiber to pass therethrough while leaving the fiber dispersed thereon, but also a huge cost is required for treatment of dust produced with process may not be regarded as an economical process.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process and apparatus for distributing a fibrous material wherein the problems found in the prior art processes are overcome, and wherein a short fibrous material can be more simply distributed even in such a small amount that the amount per unit area reaches 0.1 gm 2 as a possible lower limit on a moving sheet. More specifically, present invention aims at accomplishing the following objects while using a resinous sheet as the sheet.
(1) To avoid the use of a particular dispersing medium for fiber dispersion.
(2) To ensure a uniform dispersion of a fibrous material even in such a case that the fibrous material is dispersed in a small dispersion rate of the order of 0.1 g/m 2 -sheet as required for imparting a transparency which in turn is required for an electroconductive film for packaging use.
(3) To ensure a uniform dispersion on a continuously travelling resinous sheet of a large width.
To solve the above-mentioned problems found in the prior art processes, the present invention contemplates to apply a vibrating screen which has been used for screening of a powdery or granular material. Conventionally, the screening or classification by a vibrating screen is normally applied to powder or granules such as those of grain and inorganic, organic or synthetic resin, and may not be commonly used in the dry-system distribution of a fibrous material. The greatst reason why such screening classification is not used in the dry-system distribution of the fibrous material is that fluffy pills are produced due to entanglement of the fiber on a screening mesh or screening plate, resulting in an extremely poor efficiency of distribution.
We have discovered that the above-mentioned problems are solved and the uniform distribution of fiber can be ensured by mounting partitions on a mesh screen provided substantially in contact with the lower portion of a hopper so as to reduce the generation of the pills to the utmost and applying a contrivance to the structure of the partitions to distribute fiber through the openings of the screen, while horizontally moving the fiber on the mesh screen in a reciprocating manner, and consequently, have accomplished the present invention.
According to the present invention, it is possible to distribute a short fibrous material, for example, having a fiber length of 2 to 20 mm, in a small amount down to the lower limit in an amount per unit area of 0.1 g/m 2 onto a sheet horizontally travelling at a speed of 30 m/min or less, and it is also possible to uniformly distribute the fibrous material with a deviation of 20% or less in amount per unit area both in the longitudinal and transverse directions with respect to the direction of travelling of the resinous sheet.
The technical background of the present invention will now be described in brief.
Many factors participate in the dry-system distribution of a fibrous material. For example, a mesh screen as used in the present invention is typically made of a wire mesh, and is provided wit a fiber distributing box having side walls on the opposite sides in the direction of vibration thereof as well as on the front and rear sides in the direction of travelling of the sheet. The amount of fiber distributed by the fiber distributing box is directly related to the amount per unit area of fiber distributed onto the sheet. For example, if all of the distributed fiber is uniformly dropped onto the travelling resinous sheet, the relationship between the amount per unit area and the amount of fiber distributed can be represented by an equation:
[amount per unit area of fiber distributed on the sheet (g/m.sup.2)]=[distributing rate (g/m.sup.2.min.)]×[(area of wire mesh to distribute fiber)-(amplitude area of wire mesh to distribute fiber (m.sup.2)]/[a travelling speed of sheet (m/min.)×width of sheet (m)].
Accordingly, even if only the amount of fiber distributed is concerned, an extremely large number of factors participate in the distributing rate, such as the size of opening and the weaving pattern of the wire mesh (screen), vibrating conditions applied to a fiber distributing box including the frequency, amplitude and inclination of the wire mesh and specificities resulting from the quality of fiber such as the generation of pills due to movement of the fiber on the wire mesh. With respect to the amount per unit area of the fiber fixed in the composite resinous sheet obtained by distribution and dropping of the fiber from the wire mesh to be placed on the sheet, followed fixation under heating, the area of the wire mesh determined by subtracting an area thereof corresponding to the amplitude and the distributing rate are to be considered as relevant factors as well as the travelling speed and width of the sheet relating to the areal travelling speed of the sheet.
Further, the factors relating to uniform distribution of the fiber include: (1) the direction of vibration of the fiber distributing box with respect to the travelling direction of the sheet, (2) the length of an approach or preliminary travel section where the thickness of the fiber layer on the wire mesh, i.e., the thickness of the fiber layer on the wire mesh before the distribution is started, is made uniform, corresponding to (3) the height of the exit of the hopper means for uniformly discharging the fiber from the exit of the hopper over the entirety of the opening thereof, and (4) means for minimizing the generation of fluffy pills resulting from the movement of the fiber on the distribution box.
We have investigated various attempts relating to the above-mentioned factors and have discovered that, among others, the combination of a lateral vibration screen provided below the fiber hopper substantially in contact therewith (i.e., in an arrangement substantially avoiding free dropping of the fiber) and a partition, is effective for prevention of pills and uniform distribution of the fiber. Thus the present invention has been accomplished.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view illustrating the arrangement of an apparatus according to the present invention;
FIG. 2 is a plan view of the apparatus;
FIGS. 3 to 5 are respectively enlarged photographs (each in a magnification of 3) illustrating a pattern of carbon fiber distributed on a resinous sheet while using various distances H (mm) of dropping of screened fiber from screening wire mesh of a fiber distributing box to the resinous sheet according to Example 4 appearing hereinafter; and
FIGS. 6 to 8 are respectively enlarged photographs (each in a magnification of two) illustrating a pattern of nylon fiber distributed on a resinous sheet for respective distances of dropping of fiber according to Example 5 appearing hereinafter.
DETAILED DESCRIPTION OF THE INVENTION
Fibrous materials which may be used include single-component short fibers selected from inorganic fibers such as metal, carbon and glass fibers or organic polymeric fibers such as plastic fibers. As used herein, the term "short fiber" means fiber having a length such that entanglement of fiber which is problematic from a process point of view does not readly occur under conditions of operation according to the present invention. The length of the short fiber depends on the type of fiber used, and more specifically, short fibers preferably used are those having a diameter of about 3 to 30 microns and a length of about 2 to 20 mm and controlled to have a specific average length.
Materials of the sheet to be used in the present invention may be, for example, metals or inorganic sheets having an adhesive applied thereon, and they are not particularly limited. However, the use of resinous sheets is particularly preferred when the product is intended to be used as a packaging or molding material. The resinous sheets may comprise a material in the form of a sheet, which comprises a synthetic resin capable of fixing therein or thereon the short fiber material distributed thereon by adhesion through thermal fusion or thermal curing. Accordingly, any of thermoplastic or thermosetting resins can be used as a synthetic resin to be used for this purpose.
The present invention will now be described with reference to the accompanying drawings, while taking an example of a conductive fiber distributing method as a provisional for production of an electroconductive film (conductive fiber-composited resinous sheet) by distributing conductive fiber on a resinous sheet and securing the fibers on the sheet by hot-pressing. The following description is primarily directed to a case using short carbon fiber having an average diameter of 14.5 microns and an average length of 3 mm. The carbon fiber is screenable with a residue of 6 to 7 wt. % by a standard mesh having openings of 2 mm and with a residue of 2 to 3 wt. % by a standard mesh having openings of 4 mm. Further, a polyethylene film (having a thickness of 20 to 100 microns) is used as a resinous sheet.
FIG. 1 is a side view illustrating the arrangement of an apparatus according to the present invention. Referring to this figure, there is provided a fiber receiving hopper 1 in which a disintegrated short fibrous material is stored, so that sheared short fiber as a feed or raw material is charged into the hopper through an upper portion thereof. The hopper is desirably made in the form of a rectangular tube, pipe or chamber in order to diminish the generation of pills during storage therein and to provide a fiber discharge port or exit for permitting the discharge of the fiber in a width equal to or larger than that of the resinous sheet onto which the fiber is to be distributed. The discharge port is provided at the lower portion of the hopper and has a damper 2 for feeding the short fiber onto the distributing wire mesh 4 in a fiber distributing box 3 at a controlled rate. For the purpose of uniformly distributing the fiber onto the resinous sheet over the entire width thereof, the width of the discharge port is preferably equal to or larger than the width of the travelling resinous sheet onto which the fiber is distributed. The height of the discharge port is adjusted by vertical displacement of the damper 2, so that the short fiber within the hopper may be discharged substantially uniformly over the span of the exit in connection with the raking-out action by the vibration of the partitions mounted on the distributing box. If the height of the hopper exit is 65 to 70 mm for carbon fiber having an average length of 3 mm, the fiber is discharged substantially uniformly over the entire port, but the height exceeding 70 mm can result in either an ununiform discharge or an impossibility of discharge. When the discharge amount is too small, the fiber may move on the distributing box in the direction perpendicular to the flow of the fiber due to horizontal reciprocating vibration. Thus, the generation of pills increases, and only fractions having a shorter length are easily dropped, causing classification of fiber and failing to effect uniform distribution. Therefore, the discharge amount has a lower limit.
The portion of the fiber distributing box 3 immediately below the hopper is formed into a bottom made of a flat plate to support the short fiber within the hopper. The length of the subsequent approach travel section L1 where th short fiber discharged from the hopper may be made even to a uniform height on the bottom surface of the distribution box by vibration of the distribution box varies depending on the amount of fiber discharged from the hopper and hence, the openings in a distributing wire mesh are closed by a slide plate 9 provided below the distributing wire mesh over a certain section from the discharge exit as shown in FIG. 1 to ensure a required length of the approach travel section L1. The length of the distribution box is determined so that a required fiber distributing section L2 is adjustably set in addition to the section L1. The fiber distributing box 3 is supported on a sliding or rolling guide bearing 5 and vibrated transversely (in the direction perpendicular to the direction of travelling of the sheet) by the transmission of a reciprocating movement to the distributing box 3 through a drive motor 6 and a reciprocation converting device 7 using a cam/link mechanism and a reversing mechanism.
The distributing box is substantially horizontal, i.e., horizontal or inclined slightly downwardly in the direction of travelling of the resinous sheet. It is to be noted that even if the distributing box was inclined downwardly, the amount of fiber distributed and the uniformity of distribution were not particularly improved under the conditions of the present invention as compared with those in the case of horizontal setting. From the above fact, the horizontal setting of the distributing box which is easily carried out, is more preferable.
It is preferred to select a wire mesh (i.e., mesh screen) 4 having openings with a size substantially equal to the average fiber length of the fibrous material as a feed material, because the fibrous material can be distributed with the average fiber length at maximum. If the size of the openings is too small, the fiber may move on the distributing box in the direction perpendicular to the flow of the fiber due to the vibration. For this reason, the generation of pills increases and only fiber fractions having a shorter fiber length are preferentially distributed to cause classification of the fiber, resulting in an impossibility of continuously conducting uniform distribution of the fiber. If the size of the openings is larger, the fiber may be passed through the mesh as it remain in the form of a bundle, resulting in an ununiformly distributed pattern on the film. It should be noted however that even when the openings have a size substantially different from the average fiber length, the fiber can be uniformly distributed by providing a multi-stage mesh screen.
Preferred conditions were sought by continuously feeding the fiber into the fiber distributing box from the hopper, using a wire mesh having openings of such a size and varying the frequency and amplitude of vibration. As a result, it has been confirmed that the frequency is preferably in the range of 200 to 800 cycles/min., particularly, 300 to 450 cycles/min. and the amplitude is preferably in the range of 3 to 20 times, particularly, 10 to 15 times the average fiber length. The amount of fiber distributed is proportional to the magnitude of the frequency or/and amplitude, but if the frequency is increased too much, the flotation of the fiber on the wire mesh occurs remarkably, resulting in an increased fluctuation in amount of fiber distributed. With a frequency lower than 200 cycles/min., the amount of fiber distributed becomes too small to cause classification of the fiber due to a difference in fiber length as described above, so that continuous uniform distribution becomes impossible. An amplitude of 3 to 20 times, preferably 10 to 15 times, the average fiber length, is selected as described above. With an amplitude smaller than a value of 3 times, the generation of pills is liable to occur and further, the vibration is absorbed by the fiber to lead to a dull movement of the fiber on the screen. On the other hand, if an amplitude exceeds 20 times, the movement of carbon fiber on the wire mesh is not uniform to cause a fluctuation in amount of fiber distributed, resulting in impossibility of uniform distribution. Especially, it is preferred to select a stable range of conditions under which the generation of pills is reduced and moderate disintegration of fiber is effected on the wire mesh, based on the conditions in the above-mentioned ranges for both frequency and amplitude.
A plurality of partition plates 12 are fixedly mounted on the bottom surface of the distributing box at a suitable spacing in parallel with the direction of flow of the fiber and acts to rake out the fiber at the discharge port of the hopper. More specifically, the partition plates fulfil the following effects:
(1) When a large-sized box having an increased width is required to be used in distributing the fiber onto a wide sheet, deformation or bending of the bottom surface of the distributing box and thus the wire mesh, is fatal to uniform distribution, whereas the bottom surface of the distributing box can be reinforced by placing the partition plates.
(2) Upon vibration of the distribution box, the partition plates also vibrate therewith and hence, they serve to rake out the fiber from the lower portion of the hopper, thus making it possible to prevent the clogging of fiber at the exit of the hopper.
(3) The fiber is liable to move in the direction of the vibration which is perpendicular to the direction of proceeding of the fiber in the distributing box, and if this is permitted, the rolling of the fiber is also caused so that pills may be liable to generate, while the movement of the fiber in the direction of vibration is suppressed to the minimum by provision of the partition plates.
(4) Loosely bound pills of the fiber present in the distributing box are disintegrated by contacting the partition plates.
It is preferred that the partition plates are spaced by 10 mm or less, particularly 5 to 6 mm, from the bottom surface of the distributing box and thus from the wire mesh, because stagnation in movement of the fiber on the bottom plate can be prevented by such a spacing. It has been confirmed to be preferable that the distance between the partition plates is 30 to 100 mm and the height of the partition plate is of 20 to 50 mm, and further, a metal plate having a thickness of 2 to 5 mm is used as a partition plate.
In the present invention, the vibration of the distributing box is applied in the direction perpendicular to the direction of travelling of the resinous sheet, i.e., perpendicular to the direction of flow of the fiber on the distributing box. This is desirable for the following reason. The amount of fiber distributed is increased as compared with that in the case of vibration in the same direction as the flow of the fiber, and the uniform distribution of the fiber is provided, while the generation of pills is reduced, and the disintegration efect is ensured between the partition plates as described above.
On the other hand, when the vibrating direction as described above is adopted in the present invention, a considerably strong vibration must be applied to move the fiber on the distributing box, so that a lower limit to the frequency exists. The lower limit to the frequency is related to the amplitude, and it has been confirmed that the lower limit is 400 cycles/min. when the amplitude is 10 mm, and is 200 cycles/min. when the amplitude is 50 mm. Thus, it has been confirmed that the lower limit to the frequency is of the order of 200 cycles/min. as described above for the fiber having an average fiber length of 0.1 to 9 mm.
The apparatus is designed so that the fiber just after discharge from the hopper may be spreaded fully over the discharge port of the hopper by the vibration of the partition plate, but it is still preferred to provide an approach travel section or a certain distance from the fiber discharge port to that portion of the wire mesh at which the distribution is started, in order to ensure a distribution so as to form a fiber layer having an even thickness over the entire width of the distributing box. As described above, the approach travel section L1 is adjusted by opening or closing of the horizontal slide plate 9 provided below the wire mesh.
Preferably, the distance between the wire mesh 4 and the travelling sheet 14 may be as short as possible and more particularly, may be 100 mm at the maximum or less. With a distance exceeding 100 mm, a more uniform distribution can be attained as compared with the prior art, but a distinct spot-like pattern due to the interbundling of fiber may be observed. With a distance of 10 to 20 mm, the interbundling of the fiber would not occur and a particularly uniform distribution can be ensured. Enlarged photographs are shown in Figures as examples of the distribution patterns and in obtaining these enlarged photographs in Example 4 described hereinafter, the respectively distances of fiber dropped were 20 mm (FIG. 3), 100 mm (FIG. 4), and 150 mm (FIG. 5).
The residue remaining on the distributing wire mesh including pills and the fiber dropped outside the travelling sheet are transferred and circulated by a circulating conveyor 11. A disintegrating device 13 can be placed on the way of the transfer to effectively disintegrate pills incorporated in the fed sheared short fiber, pills produced from the long fiber incorporated in the short fiber, or pills generated during transfering and circulation, thereby enabling the fiber to be repeatedly used. The disintegrating device 13 comprises two feed rollers having slip-preventing means such as a groove or uneven surface and a single disintegrating roller having scratching means such as a notched tooth or pin. The disintegrating roller is rotated at a speed higher than that of the feed rollers to scratch the pills put between the feed rollers, thereby fully effecting the disintegration of the pills.
The sheet having the fiber distributed thereon obtained in the above manner is subjected to fixing of the fiber in an appropriate manner depending on the quality of the sheet, and the sheets thus processed are used in respective applications. For example, when the sheet is made of a resin, the thermoplastic or thermosetting property thereof is utilized to conduct the fixing, or when the sheet is made of a metal or inorganic material, an adhesive may be utilized to effect the fixing. For example, for a combination of conductive fiber and a thermoplastic resin sheet, a hot-pressing may be carried out by a process as described in the previously described Japanese Patent Laid-Open Application No. 21735/1983 if molding or shaping material is intended to be produced, or by a process as described in Japanese Patent Application No. 236772/84 developed by a research group to which we belong, if an electrocoductive film suitable as a packaging material is intended to be produced. Such an electroconductive film is used as a packaging film for an electric part, a dustproof film or an electromagnetic wave-shielding film for an electronic machine. In addition, a fiber-composited resinous molding material which has been produced by dispersing and fixing conductive fiber on a resinous sheet made of a synthetic resin as described previously and then pelletizing the resulting sheet, may be employed to produce, e.g., a molded material for a cabinet of a microcomputer for shielding an electromagnetic wave. Resinous sheets obtained by dispersing and fixing various short fibrous materials on a composited or laminated resinous sheet may also be used as wall papers.
On the other hand, resinous sheets having electrically insulating fibers such as plastic fibers and glass fiber dispersed thereon can be used, e.g., for the production of not only insulating substrates for print-wiring but also fiber-composited resinous sheets for laminate molding in general.
The present invention will now be described in more detail by way of Examples.
EXAMPLE 1
Carbon fiber was distributed onto a resinous sheet by using an apparatus shown in FIGS. 1 and 2 and having an approach travel section L1 of 150 mm or more and a distributing section L2 varied in a range of 10 to 250 mm.
More specifically, carbon fiber having an average fiber diameter of 14.5 microns and an average fiber length of 3 mm were continuously distributed onto a polyethylene film having a width of 400 mm while causing the film to travel at a speed in the range of 1 to 20 m/min. by using a distributing box having a distribution width W of 500 mm.
A distributing wire mesh of the distributing box was made of plain weave stainless steel wire mesh and had openings of 3 mm, and the distributing box was set horizontally. The amount of fiber distributed and the uniformity of distribution (in terms of deviation in amount of fiber distributed) were measured at a frequency of 370 cycles/min. and an amplitude of 30 mm. The partition plates having a thickness of 3 mm and a height of 25 mm were placed at a spacing of 4 mm above the wire mesh and at distances of 75 mm spaced from each other.
The amount of fiber distributed on the produced resinous film was measured by using, as a sample, a film piece produced by affixing, onto a travelling resinous film, a double-face adhesive tape having a side length corresponding to the width of the travelling resinous film and a side length in the travelling direction the resinous film varying in the range of 9 to 30 cm depending on the amount of fiber distributed, followed by distribution and fixing fiber on the tape. Ten samples were prepared for each test among those carried out under varying measurement conditions. The ten samples made in this manner were further divided and modified in size into square sample pieces having a side length of 3 to 10 cm depending on the amount of fiber distributed, and such pieces were used as test samples identified according to the positions thereof on the travelling resinous film. That is, the size of each sample plate was changed depending on the amount of fiber distributed, i.e., in 3 cm-square when the amount was large, and in 10 cm-square when the amount was small. This is because the sensitivity of a balance used for the measurement of the weight was 0.1 mg, and the sample size of 10 cm-square was adopted when th amount of fiber distributed was about 1 g/m 2 or less. The difference in weight of a film piece having an adhesive thereon before and after the distribution of the fiber thereon was measured to determine the amount of fiber distributed.
The amounts of distributed fiber on the above mentioned plurality of sample pieces were respectively compared with the average thereof, and the absolute differences therebetween were expressed in terms of percentages with respect to the average value. The deviation value as a measure of uniformity of distribution was represented in terms of an arithmetic mean of the thus obtained percentage differences. This is represented by the following equation: ##EQU1## wherein n stands for the number of measured examples.
The results of measurements are given in Table 1. As apparent from Table 1, the amount of fiber distributed is inversely proportional to the travelling speed of the polyethylene sheet (see Test Nos. 1 and 2) and proportional to the area of the wire mesh (see Test Nos. 1 to 6). In addition, the deviation value (%) gradually decreases and the amount of fibers distributed per area become uniform as the amount of fiber distributed increases.
TABLE 1______________________________________ Deviation inTest Amount of fiber distributedNo. Conditions distributed amount______________________________________1 L.sub.2 = 10 mm 0.38 g/m.sup.2 5.3%S.T.S.* = 20 m/min.2 L.sub.2 = 10 mm 0.76 g/m.sup.2 4.0%S.T.S.* = 10 m/min.3 L.sub.2 = 50 mm 1.87 g/m.sup.2 2.6%S.T.S.* = 20 m/min.4 L.sub.2 = 150 mm 5.47 g/m.sup.2 1.5%S.T.S.* = 20 m/min.5 L.sub.2 = 250 mm 17.50 g/m.sup.2 0.9%S.T.S.* = 10 m/min.6 L.sub.2 = 250 mm 175.0 g/m.sup.2 0.7%S.T.S.* = 1 m/min.______________________________________ *S.T.S. stands for a sheet travelling speed.
EXAMPLE 2
The same carbon fiber as in Example 1 was distributed onto the surface of a resinous film having a width of 400 mm affixed with the same double-face adhesive tape as in Example 1, while causing the film to travel at a speed of 10 m/min., by using the same fiber distributing apparatus with the frequency and amplitude of the distributing box and the openings in the wire mesh attached to the distributing box being varied.
The partition plates in the distributing box were the same as those in Example 1. A plain weave wire mesh made of stainless steel wire was used and the screening section L2 was set at a constant value of 50 mm.
The results of measurements are given in Table 2. As can be seen from Table 2, the openings in the wire mesh are preferred to have a size equal to or larger than the fiber length. If the size of the openings is constant and the frequency is increased, the amount of fiber distributed increases. If the size of the openings and the frequency are constant, the amount of fiber distributed increases also when the amplitude is increased.
TABLE 2______________________________________Conditions Amount of Deviation inOpenings in Fre- Ampli- fibers distributedTest wire mesh quency tude distributed amountNo. (mm) (c/min) (mm) (g/m.sup.2) (%)______________________________________ 7 4 375 30 5.50 2.1 8 3 450 20 4.25 2.3 9 3 400 30 4.15 2.010 3 350 30 3.75 2.211 3 300 30 3.05 3.712 3 290 50 3.75 4.313 2 375 30 2.15 3.214 2 300 50 2.00 4.415 1.68 500 20 1.88 5.616 1.68 380 40 1.75 5.9______________________________________
EXAMPLE 3
Using the same fiber distributing apparatus, travelling polyethylene film and fiber to be distributed as in Example 1, the fiber was distributed onto the travelling polyethylene film, and the uniformity of distribution was evaluated for a predetermined amount of fiber distributed (amount per unit area) set by using a light-penetration method for detecting the distributed amount, while adjusting the frequency and amplitude of the distributing box and the area of the wire mesh by means of the slide plate below the wire mesh of the distributing box.
The used wire mesh of the distributing box was the same as in Example 1, and the travelling speed of the resinous film was 10 m/min.
The results of the measurements are given in Table 3, and as apparent from Table 3, it was confirmed that the carbon fiber-composited polyethylene film having an amount of fiber per unit area in a wide range of 1 to 20 g/m 2 could be produced with the fiber uniformly distributed thereon by the adjustment of the amount of fiber distributed by use of th amount-detecting device according to the light-penetration scheme.
TABLE 3______________________________________Test Set amount of fiber Deviation value inNo. distributed (g/m.sup.2) measured amount (%)______________________________________17 1 1.218 3 0.819 10 0.520 20 0.5______________________________________
EXAMPLE 4
The same fiber to be distributed in Example 1, was distributed onto a travelling polyethylene film, and the patterns of fiber distributed on the film depending on the distances of fiber dropped between the wire mesh of the distributing box and the travelling film were observed.
FIG. 3 shows a pattern of fiber distributed from the surface of the wire mesh when the distance of fiber dropped was 20 mm.
FIGS. 4 and 5 respectively show patterns of fiber distributed when the distances of fibers dropped were respectively 100 mm and 150 mm.
As can be seen from FIGS. 3 to 5, if the distance of fiber dropped from the wire mesh onto the film was 100 mm or less, then a mesh-like uniform pattern of distributed short fiber was provided. If the distance of fiber dropped exceeded 100 mm, then the distributed fiber could cause entanglement during the dropping in the space between the wire mesh of the distributing box and the travelling polyethylene film, resulting in a spot-like pattern, and thus, the uniform distribution was not exhibited. Such a pattern is shown in FIG. 5 wherein the distance of fiber dropped was 150 mm.
EXAMPLE 5
Using the same fiber distributing apparatus as in Example 1, nylon fiber having an average fiber diameter of 30 microns and an average fiber length of 5 mm as a short fibrous material was distributed onto the surface of polyethylene film having a width of 400 mm and provided with an adhesive thereon.
It was confirmed that as conditions under which the uniform distribution was ensured, a frequency of 250 cycles/min. and an amplitude of 50 mm were appropriate for a stainless steel wire mesh of plain weave having openings of 4.5 mm. The film was caused to travel at a speed of 10 m/min., and the patterns of nylon fiber distributed onto the film depending on the distances of fiber dropped between the wire mesh of the distributing box and the travelling resinous film was observed in the same manner as in Example 4. The used partition plates in the distributing box were the same as those in Example 1.
The distance of fiber dropped was varied from 50 mm to 500 mm to observe the patterns of fiber distributed on the film. The results showed that if the distance of fiber dropped was 200 mm or less, the uniform distribution was ensured, but if the distance exceeded 200 mm, then the entanglement of the fiber occurred to prevent the uniform distribution. In FIGS. 6, 7, and 8, there are shown patterns of fiber distributed when the distances of fiber dropped were 50 mm, 200 mm and 500 mm, respectively.
As apparent from the foregoing Examples, with process and apparatus according to the present invention, it is possible to dispersively distribute more simply and uniformly, onto a travelling sheet, fibers which have neither been distributed easily nor dispersed uniformly because they are flexible and liable to form fluffy pills, thus making it possible to continuously produce, in a lower cost, electroconductive films, sheets or fiber-reinforced composite molded products which will be expected in application as packaging materials and molding materials. Particularly, the process according to the present invention is useful as a process for producing a thin film-like composite functional material because of possibility of dispersively and uniformly distributing an extremely small amount of sheared short fiber.
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A process and an apparatus for distributing short fibrous material onto a horizontally travelling sheet. A disintegrated short fibrous material is fed into a hopper comprising a substantially hollow casing disposed above the travelling sheet and having a fiber discharge port at a lower portion with of a side wall on the downstream side. A mesh having a width equal to or larger than that of the travelling sheet and having partitions provided thereabove for suppressing the transverse movement of the fiber is provided below the hopper and with a spacing above the travelling sheet. The mesh screen is horizontally and transversely vibrated to distribute the fiber therethrough onto the travelling sheet, whereby the fiber is uniformly distributed without causing pilling even if it is fed at a considerably small rate.
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REFERENCE TO RELATED CASE
This application is a continuation-in-part of copending U.S. patent application Ser. No. 08/558,988 filed on Nov. 10, 1995 by W. Neuberger, V. V. Volodjko, L. M. Blinov, inventors, entitled "Process and Equipment for Manufacturing Glassbodies for the Manufacturing of Optical Fiber" abandoned; which in turn was a continuation of U.S. patent application Ser. No. 08/201,526 filed on Feb. 25, 1994, now abandoned; which was a continuation-in-part of U.S. patent application Ser. No. 07/948,260 filed on Sep. 21, 1992, now abandoned, and incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a process for manufacturing preforms used in optical fibers, and more specifically to manufacturing preforms by outside reactive deposition.
2. Information Disclosure Statement
The prior art regarding reactive deposition essentially centers around two methods: inside reactive deposition and outside reactive deposition. Several patents disclose methods for the inside coating of a core material For example, Greenham et al., U.S. Pat. No. 4,936,889, Moisan et al., U.S. Pat. No. 4,944,244, Auwerda U.S. Pat. No. 4,714,589, Nourshargh U.S. Pat. No. 4,619,680, and European Patent DE-PS 24 44 100 are exclusively concerned with inside deposition methods. Additionally, European Patent DE-OS36 32 684 discloses a resonator design useful for performing an inside reactive deposition.
The inside reactive deposition process involves generating a plasma zone inside a tube, and axially moving the tube relative to the plasma generating equipment. The reactive deposition is performed in a pressure range of 1 to 10 Torr, and a temperature zone is superimposed over the plasma zone. Because the reaction chamber is small, this process provides good control of the reactive gas and maintains a clean depositing environment.
The product obtained from the process is a preform which is used to draw an optical fiber. For data communication applications, the light conducting core of the fiber is usually small in comparison with the outside diameter of the fiber. The process of inside deposition (as described by the above mentioned patents) is suitable for this application.
Other applications such as laser delivery or sensing systems, however, require fibers with a large, usually undoped core and a relatively thin, mostly fluorine doped cladding. For these applications, it is preferred to start the manufacturing process from an undoped, commercially available quartz glass rod of high purity and to deposit only a relatively thin doped layer on its outside. The inside deposition method on the other hand requires a high quantity of material to be deposited in this case because the core area is large. Consequently, this method consumes a large part of the gas mixture.
The manufacturing of preforms with high core to clad ratios is usually performed starting from undoped quartz rods. These rods are then coated on the outside with a doped quartz layer by means of atmospheric plasma burners. This process suffers from several shortcomings such as environmental contamination and the elaborate measures required to maintain purity of the deposited substance in the open atmosphere. Consequently, the atmospheric plasma burner yields much lower reagent disassociation and deposition efficiencies of silica. For example, Mansfield, U.S. Pat. No. 4,863,501 describes an atmospheric plasma burner depositing soot, not fused silica.
One method that avoids a plasma burner is described in AJlG (DE 3331899 A1). That patent describes a method for the reactive deposition on a glass-body. More specifically, it describes a method for the production of preforms where the essential advantage claimed is the absence of moving parts. This is achieved by inserting a rod in the center of a discharge tube and filing the tubes with gas. Next, a theta pinch plasma reaction is initialized to compress the ionized gas particles towards the rods surface where layers are successively deposited.
This process, however, has several shortcomings. A major disadvantage of this method is a build-up on the inside of the tube and not the rod. This results because the inductive discharge produces maximum field strength on the inside of the tube. Additionally, the extremely strong ionization that would be required to produce the radial compression toward the rod would inhibit the chemical process necessary for effective deposition. Finally, the high field strength required would make a continuous process impractical and perhaps impossible.
Therefore, a need exists to deposit layers on the outside of a glass-body, to maintain high gas efficiencies, to avoid contaminating layers, to minimize build up on the inside of the device, and to provide for possible continuous processing. The present invention fulfills these needs. SUMMARY OF THE INVENTION
The present invention is directed at an improved method for reactive deposition in the production of preforms. It is a particular object of the invention to deposit layers on the outside of a starting body while maintaining high gas efficiencies, avoiding contamination of the layers, and allowing for a continuous process. This is accomplished by using a wave type resonator in a controlled atmosphere. The resonator in the present invention avoids the extra consolidation stage necessary in the Mansfield patent because the system works at low pressures (several Torr) and the resonator produces a much higher field intensity (E) than a burner as described in the Mansfield patent. Since deposition efficiency strongly increases with field intensity (E), the present invention promotes higher deposition rates of fused silica glass.
It is another object of the invention to deposit on the outside of a starting body while suppressing deposition on the inside walls of the tube. The invention achieves this object by achieving a maximum field strength in the region of the starting body and a node in the field strength near the tube. Since the deposition relates to field strength, the layers would tend to form on the starting body rather than the inside of the device. Alternatively or in combination, the present invention maintains a radial protective gas flow through (a porous) tube which buffers the inner wall from the reactive gas.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, the several figures in which like reference numerals identify like elements and in which:
FIG. 1 shows a longitudinal cut through a device for manufacturing outside coated glass rods or glass tubes for the manufacturing of optical fiber by means of a plasma generator.
FIG. 2 shows the cross section of the same device.
FIG. 3 gives an overview of the device inside a furnace.
FIG. 4 shows details of another preferred embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The prime feature of the experimental devices and procedures, described below, is providing means for suppressing deposition on inside walls of a deposition chamber while achieving a highly efficient deposition on the surface of the starting body. In one preferred embodiment this involves having a way to produce and isolate a specific wave structure in the resonator cavity so that the electric field intensity is at its highest value near the surface of glass-body on which deposition is desired, while simultaneously the electric field intensity has a node, i.e. a zero value, at the inside walls of the cavity. The plasma is strongest where the electric field strength is greatest and thus the deposition is most favored there as well.
A key to achieving such an electric field intensity distribution has been found by isolating a specific electromagnetic wave type within the resonator/deposition chamber, having the form E 020 , using polar coordinates [z,r,φ] to describe the cylindrical symmetry of the resonator/deposition chamber There are at least three ways to achieve this:
a. resonator geometry such that the desired E 020 wave is stable within the resonator chamber while other waves are unstable due to deconstructive addition from reflections within the chamber;
b. geometry of the entrance for the microwaves into the resonator chamber, which can interfere with non-selected wavelengths as they enter the chamber; and
c. specialty microwave filters introduced to the resonator chamber at some distance outside of the chamber center, where the starting body and inner wall are positioned.
In one alternative embodiment described below, the suppression of deposition along the inner wall surrounding the starting body is achieved by providing a protective gas flow over and through the inner wall. To achieve highly efficient deposition on the starting body surface, though, the microwave initiated plasma should still have a maximum in its wave amplitude near the surface of the starting body.
A device for performing the process of manufacturing outside coated glass-bodies is shown in FIGS. 1 and 2. In one preferred form, the device comprises a vessel 2 which defines a channel 5. Channel 5 is adapted to receive a cylindrical, starting body 1 and a reactive gas.
Starting body 1 is composed of a dielectric material, and has several preferred embodiments. For example, it could be shaped as a rod or tube, and could be comprised of undoped quartz glass, doped quartz glass, or ceramic.
The reactive gas surrounds starting body 1 and has current I and pressure P1. The reactive gas contains a coating material precursor. Reactive deposition causes the coating material precursor to react and deposit out of the reactive gas, thereby changing the reactive gas to a spent gas.
A reactive gas supply means 12 supplies channel 5 with the reactive gas, and evacuates the spent gas. Reactive gas supply means may be fashioned after any gas supply/exhaust means known in the art. Such devices traditionally comprise either a positive pressure or vacuum pump, filters, reactors, connectors, and control devices.
A resonator 4 generates a plasma zone 3 within channel 5 which concentrically envelopes starting body 1. Plasma zone 3 facilitates the reactive deposition of the coating material precursor on starting body 1. Suitable windows 7 on resonator 4 provides homogeneous field strength distribution. Radiation of the plasma to the outside is limited by means of a barrier wall 6 that surrounds vessel 2.
Wave energy supply means 8 supplies resonator 4 with wave energy, and is well known in the art. In the preferred embodiment shown in FIG. 1, the wave energy supply means comprises a hollow waveguide to supply microwave energy to resonator 4.
FIG. 3 depicts a schematic of the total assembly. Here, starting body 1, vessel 2, and resonator 4 are positioned inside furnace 9, and are connected by connecting means 11. Connecting means 11 connects vessel 2 and resonator 4 such that they can move axially in relation to one another. For example, vessel 2 may remain stationary while resonator 4 moves. In either case, connecting means 11 allows resonator 4 to apply a desired level of coating to starting body 1. A slit 10 in furnace 9 allows resonator 4 together with hollow waveguide 8 to move along starting body 1. The device is not dependent upon gravity, and consequently, can have horizontal, vertical or inclined orientation. A vertical arrangement, however, may be preferred to avoid bending problems due to gravity when starting body 1 is heated.
Deposition of the gas on the inside of vessel 2 is limited by suppressing means. Suppressing means comprises several different embodiments. For example, resonator 4 can be chosen to isolate E 020 as a standing wave within it. In general electrodynamics theory, E lmn means the electric field intensity distribution along the cylindrical space coordinates z, r, φ. The zeros in the classification indicate a homogeneous field at that particular coordinate (no zero point transitions). From E 020 therefore corresponds to an electric field that has a radial distribution such that the field strength is at a node value on the inside of vessel 2 and maximized near the outside of starting body 1. This is indicated in FIG. 2 where the field distribution curve EZ of the E-field of resonator 4 is shown as a dashed line. Since reactive deposition relates to the field strength of resonator 4, deposition will occur mostly at the surface of starting body 1 and minimally at the inside of vessel 2.
As an illustrative example, referring to FIGS. 1-3, the deposition conditions to deposit a fluorosilicate cladding over a pure silica core starting body is presented. A 2.5 kilowatt microwave source operating at 2.45 GHz generates microwaves which enter wave energy supply means 8 and are guided into resonator 4. Reactive gas supply means 12 supplies channel 5 with a mixture of oxygen, silicon tetrachloride, and perfluoroethane approximately in the ratio of 133 to 20 to 1, respectively, to yield a pressure of 4.8 mbar within channel 5. Starting body 1 is a pure silica rod having a diameter of 24 mm and channel 5 has a diameter of 46 mm. This combination works well to isolate the E 020 field within channel 5 and to have the maximum field energy near the surface of the pure silica rod. The cladding deposition is allowed to proceed until the diameter of starting body 1 is increased to about 26.4 mm. Because of the relatively small change in diameter of starting body 1 during the deposition the maximum field strength of E 020 remains near the surface of the silica rod. Furnace 9 surrounds resonator 4 and starting body 1 and is set at about 1120° C. to cause the newly deposited material to consolidate onto starting body 1. The final product is a composite silica rod called a preform which is used as the starting point for the production of optical fibers for various photonic applications, including laser surgery, sensing, spectrophotometry and optical metrology.
FIG. 4 shows another preferred embodiment of the invention's suppressing means. Here, vessel 2 comprises two concentric walls, an outer wall 2b and a gas permeable inner wall 2a. Outer wall 2b and inner wall 2a form an annular volume 5a. Annular volume 5a is adapted to receive a suppressing gas with a pressure P2 which is higher than pressure P1 of the reactive gas in channel 5. In one preferred embodiment, suppressing gas consists of Oxygen. By maintaining a suitable positive pressure difference (P2-P1) across inner wall 2a, the suppressing gas flows from annular volume 2b to channel 5 just inside inner wall 2a. This suppressing gas layer prohibits the deposition of coating material on the inside of vessel 2 in a gas-dynamic manner. The material comprising inner wall 2a is suitably chosen to be a water-free dielectric like quartz glass or ceramics.
FIG. 4 shows an suppressing gas supply means 13 which supplies annular volume 5a with the suppressing gas, and if needed, evacuates annular volume 5b. Suppressing gas supply means 13 may be fashioned after any gas supply/exhaust means known in the art. Such devices traditionally comprise either a positive pressure or vacuum pump, filters, reactors, connectors, and control devices.
The process of reactive deposition is achieved by filing channel 5 with the reactive gas and surrounding starting body 1. Resonator 4 generates plasma zone 3 within channel 5 on the surface of starting body 1. Starting body 1 should be aligned such that plasma zone 3 concentrically envelopes it. This allows preforms with a large core to clad ratio to be manufactured in a controlled atmosphere with a good efficiency of gas usage and high quality. These conditions insure the preforms' usefulness in optical fiber production. The results are particularly good if the reactive deposition of the coating material precursor is performed using a pressure range of one to twelve Torr and a temperature zone is superimposed on the plasma zone.
Deposition of the coating material on the inside of vessel 2 is suppressed by keeping the field-strength of resonator 4 at the inside of the vessel at a low level and/or maintaining a suppressing gas-layer at the inside surface of vessel 2.
In a preferred embodiment of the invention, fluorine and/or boron doped SiO 2 is deposited on the outside surface of a pure SiO 2 starting body 1. The concentration of at least one dopant(fluorine or boron) could be maintained constant over an essential part of the deposited layer, or it could be continuously increased or decreased as the layer thickens. The described process can also be used in the manufacture of graded index fibers. To this end, the refractive index of successively deposited layers is continuously decreased towards the outside of the preform.
Once the preform is manufactured, it may be desirous to remove starting body 1 before drawing of an optical fiber. This removal could be accomplished by cracking out starting body 1, or by drilling out starting body 1. Removing starting body 1 leaves a hollow preform which may need to be collapsed before drawing into optical fiber. To collapse the preform, a glass lathe and a hydrogen-oxygen burner name could be used.
Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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The present invention is directed at a method and device for manufacturing a preform. The method involves arranging a starting body within a channel as defined by a vessel. Then, the channel is supplied with a reactive gas containing a coating material precursor. A resonator then generates a plasma zone within the channel. The starting body is aligned in the channel such that the plasma zone concentrically surrounds the starting body. The axial movement of the resonator relative to the starting body is controlled such that a desired layer of coating material precursor reactively deposits on the starting body to form the preform. The method suppresses deposition on the inside of the vessel via suppressing means, which may involve inducing nodes in the E-field at the vessel walls, or using an suppressing gas on the inner surface of the vessel, or a combination of the two. The present invention is also directed at a device to facilitate the aforementioned method.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Provisional Application Ser. No. 60/676,204, filed Apr. 29, 2005 and Ser. No. 60/602,847, filed Aug. 19, 2004.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was supported by a grant from the Environmental Protection Agency Grant No. RD 830904. The U.S. Government has certain rights to this invention.
STATEMENT REGARDING GOVERNMENT RIGHTS
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] (1) Field of the Invention
[0005] Polyhydroxyalkanoates (PHAs), particularly polyhydroxybutyrate (PHB), are biodegradable polyesters derived from renewable resources and have shown excellent promise as environmentally friendly substitute for polypropylene (PP). This invention aims to reduce the inherent brittleness of PHA's (PHB), while retaining their attractive stiffness and strength, by incorporating functionalized (reactive) rubbers. This provides significant improvement in toughness with minimum compromise in the stiffness. Preferably clays are provided in the composites.
[0006] (2) Description of Related Art
[0007] Many semi-crystalline polymers like PHB, Nylon and PP exhibit very attractive strength and ductility at room temperature and under moderate rates of deformation. However, they become brittle under severe conditions of deformation such as low temperature or high strain rates, and can undergo a sharp ductile-to-brittle transition (Lu, et al., Journal of Applied Polymer Science, Vol. 76, 311-319 (2000)). In the brittle regime a crack can propagate with little resistance. Because of this poor performance at extreme conditions there has been considerable commercial and scientific interest in the toughening of semi-crystalline thermoplastics. An extensive literature is now available on the toughening of commodity as well as engineering polymers such as polyethylene (Bartzcak et al., Polymer, 40, 2331-2346 (1999); Bartzcak et al., Polymer, 40, 2347-2365 (1999); and Macromol. Mater. Eng. 289 360-367 (2004)), polyamide (D. M. Laura et al., Polymer 42, 6161-6172 (2001)), polypropylene (Ismail, H. and Suryadiansyah, Journal of Reinforced Plast. And Composites, 23, 6, 639-650 (2004); Van der Wal et al., Polymer, 39, 26, 6781-6787 (1998); and Van der Wal et al., Polymer, 40, 6031-6075 (1999)) and polyvinylchloride [Ishiaku et al., Journal of Applied Polymer Science, Vo. 73, 75-83 (1999); and Ishiaku et al., Journal of Applied Polymer Science, Vol. 69, 1357-1366 (1998)).
[0008] Under proper conditions and using appropriate compatibilizers, synergistic effects arise to create high impact toughened polyolefins (TPO). Typically, a stiff filler material is incorporated into this TPO matrix to overcome the lost stiffness and strength. These fillers were conventionally glass fibers (Mehta et al., Journal of Applied Polymer Science, Vol. 92, 928-936 (2004)) but recent developments and results (Okada, O., et al., Mater Res Soc. Symp Proc., 171, 45 (1990); Pinnavaia, T. J., et al., ACS Symp Ser 622, 250 (1996); Messersmith, P. B., et al., Chem Mater 6, 1719 (1994); Yano, K., et al., J. Poly Sci Part A: Polym Chem., 31, 2493 (1993); Vaia, R. A., et al., Chem Mater 5, 1694 (1993); Wang, Z., et al., Chem Mater 10, 3769 (1998); Ke, Y., et al., J. Appl Polym Sci 71, 1139 (1999); Hasegawa, N., et al., J. Appl. Polym. Sci. 63, 137 (1997); and Mohanty, A. K., et al., Proceedings of 9 th Annual Global Plastics Environmental Conference (GPEC 2002), Feb. 26 & 27 (2003), Detroit Mich., Society of Plastics Engineers, Plastics Impact on the environment, Full paper published in the Proceedings 69-78, (2003)). Use of a nanoclay has been described in TPO's.
[0009] The incorporation of rubber particles into a brittle thermoplastic matrix is known to improve the impact properties and the toughness of the polymer (Amos, J. L., et al., U.S. Pat. No. 2,694,692 (1954); Baer, et al., U.S. Pat. No. 4,306,040 (1981); and Patel, P., et al., Rubber-toughened thermoplastics, Brit. Pat. (1978)). Under proper conditions and using appropriate compatibilizers, synergistic effects arise to create high impact toughened blends. But, adding low modulus rubber particles to the polymer lowers the stiffness and strength and this reduction in rigidity significantly lowers the scratch/mar resistance of the resulting blends. This problem has hindered the growth of rubber-toughened thermoplastics in the automotive industry. Hence, to overcome this brittleness, high modulus fillers like clay are incorporated into the toughened blend which, with optimal processing and chemistry, can regain this lost strength and stiffness (Suzuki, K., et al., Thermoplastic resin nanocomposites with good heat and impact resistance and rigidity for automobiles, Jpn. Kokai Tokyo Koho (2004); Ito, T., et al., Manufacture of polyolefin compositions for automobile parts with improved rigidity and heat resistance, Jpn. Kokai Tokkyo Koho (2004): and Maruyama, T., et al., Rubber nanocomposites containing layered clay minerals well dispersed therein, Jpn. Kokai Tokkyo Koho (2004)). General Motors and supplier partners recently launched a nanocomposite TPO-based step-assist which was the first instance of a nanocomposite material being used in automotive exterior applications (http://www.scprod.com/gm.html).
[0010] However PP and subsequently TPO are both non-biodegradable and also petroleum-based. Vast amounts and varieties of such plastics, notably polyolefins, are currently produced from fossil fuels, consumed and discarded into the environment, ending up as un-degradable wastes. Manufacturers are looking for alternative eco-friendly green materials that can replace these non-renewable-resource based non-biodegradable materials. Numerous recent federal acts and executive orders encourage the development of biobased products to assist in ‘greening’ the country through recycling and waste-prevention. These green biomaterials not only protect the environment and reduce greenhouse gasses but also increase national security by reducing dependency on foreign oil for our needs.
[0011] Another route to overcome the inherent brittleness of polyhydroxybutyrate is by using polyhydroxybutyrate-hydroxyvalerate (PHBV) copolymers, which have low levels of valerate. However, PHBV exhibits lower melting point than PHB and so narrows the utilization temperature range of the composition. PHBV is also costlier than PHB and this hinders its scope and usage.
[0012] U.S. Pat. No. 5,714,573 to Randall et al describes polylactide polymer compositions. The present invention does not use lactide polymers.
[0013] Based on the above literature, the following problems were identified with conventional toughened polymers:
1) The incorporation of rubber particles into a brittle thermoplastic matrix is known to improve the impact properties and the toughness of the PHA polymer but only under proper conditions and using compatiblizers. 2) Adding elastomer particles to the PHA polymer lowers stiffness and strength and this reduction in rigidity significantly lowers the scratch/mar resistance of the resulting blends. 3) Stiffness and strength of the PHA polymer can be regained by adding a stiff reinforcement like nanoclay but property improvements are only achieved if optimum dispersion and compatibility are created. 4) Clay is inherently hydrophilic and hence does not mix with the PHA polymer matrix. This leads to agglomeration and poor properties and this has to be overcome by modifying the clay surface. 5) Conventional TPO's are based on non-renewable resources and hence are not sustainable or ecofriendly and there is a need for alternative eco-friendly green materials that can replace these non-renewable-resource based non-biodegradable materials. 6) Performance limitations and high cost however have limited these PHA biopolymers to niche markets. 7) PHB is typically a bacterial biobased polymer. It has mechanical properties very similar to the matrix polymer PP in TPO. However, PHB's main drawbacks are its brittleness and thermal instability.
OBJECTS
[0021] It is an object of this invention to improve the toughness and impact strength of PHA's without compromising its inherent stiffness and strength. It is also an object of the present invention to provide PHA composites which are relatively inexpensive and easy to manufacture. These and other objects will become increasingly apparent by reference to the following description.
SUMMARY OF THE INVENTION
[0022] The present invention relates to a toughened polymer composition which comprises a reacted mixture of:
(a) a polyhydroxy alkanoate (PHA) polymer: (b) a maleated polybutadiene rubber; and (c) an epoxidized natural or synthetic rubber,
wherein the mixture has been reactively blended in proportions to produce a polymer which is toughened in relation to PHA alone. The PHA's are derived from monomers containing 4 to 8 carbon atoms.
[0026] The present invention also relates to a composition derived from a reactively blended admixture comprising:
(a) between about 50 and 60 parts by weight of a polyhydroxyalkanoate (PHA) polymer having a molecular weight between about 100,000 and 1,000,000 and repeating alkanoate units having 1 to 8 carbon atoms; (b) between about 5 and 20 parts by weight of a maleated polybutadiene rubber having a molecular weight between about 1500 and 7500; and (c) between about 10 and 40 parts by weight of an epoxidized natural or synthetic rubber.
[0030] Preferably the PHA is polyhydroxybutyrate (PHB). Preferably between 10 and 30 parts by weight of a plasticizer is reactively blended in the admixture. Preferably 1 to 15 parts by weight of clay is reactively blended in the admixture. Preferably the clay is a natural clay which is unmodified. Preferably the clay is an organic onium ion modified clay. Preferably the clay is a quaternary ammonium modified clay. Preferably the clay has been modified by reaction with a titanate coupling agent containing 48 to 60 carbon atoms. Preferably the metal coupling agent is titanate coupling agent containing 60 carbon atoms. Preferably the clay is modified by addition of 1 to 15 parts by weight of the titanate coupling agent. Preferably the modification is done in aromatic solvent. Preferably the modification is done in an aliphatic solvent. Preferably the modification is done by solvent-less reaction. Preferably the modification technique atomizes and sprays the coupling agent directly onto the clay.
[0031] The present invention also relates to a process for producing a toughened polymer which comprises reactively blending an admixture of:
(a) a polyhydroxy alkoxide (PHA) polymer: (b) a maleated polybutadiene rubber; and (c) an epoxidized natural or synthetic rubber,
wherein the composition has been reactively blended in proportions to produce a polymer which is toughened in relation to PHA alone.
[0035] The present invention also relates to a process for producing a toughened polymer which comprises reactively blending an admixture of:
(a) between about 50 and 60 parts by weight of a polyhydroxyalkanoate (PHA) polymer having a molecular weight between about 100,000 and 1,000,000 and repeating alkanoate units having 1 to 8 carbon atoms; (b) between about 5 and 20 parts by weight of a maleated polybutadiene rubber having a molecular weight between about 1500 and 7500; and (c) between about 10 and 40 parts by weight of an epoxidized natural or synthetic rubber. Preferably the PHA is polyhydroxybutyrate (PHB). Preferably between 10 and 30 parts by weight of a plasticizer is reactively blended in the admixture. Preferably 1 to 15 parts by weight of clay is reactively blended in the admixture. Preferably the clay is a natural clay which is unmodified. Preferably the clay is an organic onium ion modified clay. Preferably the clay is a quaternary ammonium modified clay. Preferably the clay has been modified by reaction with a titanate coupling agent containing 48 to 60 carbon atoms. Preferably the metal coupling agent is a titanate coupling agent containing 60 carbon atoms. Preferably the clay is modified by addition of 1 to 15 parts by weight of the titanate coupling agent. Preferably the modification of the clay is done in an aromatic solvent. Preferably the modification of the clay is done in an aliphatic solvent. Preferably the modification is done by a solvent-less reaction. Preferably the modification technique atomizes and sprays the titanate coupling agent directly onto the clay.
[0039] The present invention particularly relates to a polymer composition which comprises a reacted blend of (a) polyhydroxybutyrate (PHB); (b) epoxidized natural or synthetic rubber (ENR); (c) maleated polybutadiene rubber (MR); and (d) optionally an organometallic modified clay (OMC).
[0040] Further the present invention relates to a process for preparing a polymer composition which comprises melt compounding in an extruder, a mixture of PHB; epoxidized natural or synthetic rubber (ENR); maleated polybutadiene rubber (MR); and optionally an organometallic modified clay (OMC). The invention also relates to a process for modifying the pristine clay using either solvent-based solution technique or non-solvent atomizing technique.
[0041] This invention uses epoxidized natural or synthetic rubber as the impact modifier which has reactive centers for interaction with the PHB matrix. This invention also uses maleated rubber as interfacial compatibilizer. Preferably the clay is treated with a titanate-based coupling agent. All the above factors synergistically combine to create a High impact-high strength material with improved impact strength and improved modulus due to good interfacial bonding and dispersion of the nano-filler.
[0042] The titanate coupling agents are a broad class of neoalkoxy titanates. The chemical description of the preferred titanate is titanium IV 2,2(bis 2 propenolatomethyl)butanolato, tris(dioctyl)pyrophosphato-O. The structure and a different nomenclature is shown in Scheme 4.
BRIEF DESCRIPTION OF FIGURES
[0043] FIGS. 1A to 1 D are drawings showing in FIGS. 1A to 1 C a DSM microcompounder extruder with an injection molder for producing molded specimens, and a transfer pot. FIG. 1D shows the overall apparatus.
[0044] FIG. 2 is a drawing showing direct injection of liquid maleated rubber into PHB-rubber system.
[0045] FIG. 3 is a drawing showing an atomizing-spraying process for clay modification.
[0046] FIG. 4 is a graph showing the comparative impact strength of PHB-epoxidized natural rubber with maleated rubber compatibilizer versus other compositions.
[0047] FIG. 5 is a graph showing comparative modulus of PHB-epoxidized natural rubber with maleated rubber-II compatibilizer versus other compositions.
[0048] FIG. 6 is a graph showing a variation of the modulus of PHB and the toughened PHB with temperature versus other compositions.
[0049] FIG. 7 is a schematic representation of the titanate modified clay.
[0050] FIG. 8 is a graph showing the impact properties of toughened PHB nanocomposites versus other compositions.
[0051] FIG. 9 is a graph showing modulus of toughened PHB nanocomposites versus other compositions.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0052] The chemical structures of PHB, Natural rubber and epoxidized natural rubber are shown in Schemes 1, 2 and 3 respectively.
[0053] Polyhydroxybutyrate, PHB (Biomer P226) with 23 wt. % citrate plasticizer was supplied by Biomer (Germany). Epoxidized natural or synthetic rubber (ENR 25), which is a chemically-modified form of natural or synthetic rubber with epoxide rings on the chain, with 25% epoxidization, was used as the functionalized rubber. The maleated rubber compatibilizer (RI 130 MA20) was provided by Sartomer (Exton, Pa.).
[0054] Commercially modified montmorillonite (organoclay) (Cloisite 30B) was purchased from Southern Clay (Gonzales, Tex.) and pristine clay (PGW) was purchased from Nanocor (Arlington Heights, Ill.). The ammonium cation of Cloisite 30B, is methyl tallow bis-2-hydroxyethyl quaternary ammonium.
[0055] Titanate based coupling agents were provided by Kenrich Petrochemicals as LI-38 neopentyl(diallyloxy)tri(dioctyl)pyrophospato titanante. The structures are shown in Scheme 4.
[0056] Baseline data for comparison studies was obtained using a commercial TPO from Basell. The materials and suppliers are shown in Table 1.
TABLE 1 Materials list Material Name Tradename Supplier Location Polyhydroxybutyrate PHB Biomer ® P- Biomer Krailling, Germany 226 Epoxidized Natural ENR Research Malaysian Malaysia Rubber Sample Rubber Board Maleated MR RI130MA20 Sartomer Exton, PA Polybutadiene Organically OMMT Cloisite ® 30B Southern Clay Gonzales, modified Products Inc TX montmorillonite Pristine Na+ MT Cloisite Na+ Southern Clay Gonzales, montmorillonite Products Inc TX neopentyl Titanate Ken-react ® Kenrich Bayonne, (diallyl)oxy based LICA-38 Petrochemicals NJ tri(dioctyl) coupling pyrophosphato agent titanate Toluene Toluene Toluene Aldrich St. Louis, 179418 ACS MO reagent, >99.5% Aliphatic Aliphatic Kwik-Dri Ashland Columbus, hydrocarbon Solvent Distribution OH Thermoplastic TPO Medium Basell Elkton, MD Olefin impact research sample
[0057] The technique used for blending PHB and rubber was melt compounding in a microcompounder ( FIGS. 1A to 1 D). The parts are standard and are:
[0058]
FIG. 1
1 . Barrel
2 . Screws
3 . Exit port
4 . Feeder
5 . Feeder port
6 . Injector
7 . Mold and mold heater
8 . Transfer cylinder
9 . Piston
10 . Pneumatic piston
11 . Pressure gauge
12 . Piston control knob
13 . Mold temperature controller
14 . Transfer Cylinder temperature controller
[0073] This apparatus is a laboratory scale twin-screw extruder with an attached injection molder. Varying amount of rubber (10, 20, 30 and 40 wt. %) was blended with PHB at 200 rpm and 170° C. for 2-3 minutes along with varying amount of compatiblizers (5, 10 and 20 wt %). These compatiblizers are liquids and were incorporated into the PHB-rubber system by direct injection into the barrel ( FIG. 2 ). These processing conditions were based on initial optimization studies. The optimized formulation is given in Table 2 (Run 3).
TABLE 2 Run PHB Epoxidized rubber Maleated rubber 1 100 — — 2 60 40 — 3 60 30 10
[0074] Clay modification: The surface of the clay platelets is inherently hydrophilic and is modified by surface treatments to make the platelet compatible with the organic polymer. This is achieved by exchanging the metal counterions from the clay surface with cationic-organic surfactants so as to form a molecular organophilic coating. The hydroxyl functionality on the surface of the clay platelet is substituted by an alkyl-titanate group from the titanate modifier making the surface organophilic. These titanate coupling agents form chemical bonds between inorganic and organic species via proton coordination and form an atomic layer on the surface of the clay by chemical modification. The large alkyl group also increases the inter-clay platelet spacing and hence facilitates intercalation and exfoliation.
[0075] Clay modification work was done on pristine montmorillonite clay (Nanocor PGV). In a first process, the coupling agent was coated onto the clay by two techniques; in one process the titanate-additive was dissolved in solvent and then the clay was dispersed into it and mixed for 2 hours. The solvent used is an aromatic toluene (Toluene, Aldrich Chemicals), and a non-aromatic aliphatic eco-friendly solvent (Qwikdri™, Ashland Chemicals) could also be used. Following the dispersion, the clay was decanted and dried for 5 hours at 55° C. to drive off the solvent.
[0076] The second process was by atomizing the coupling agent onto a fluidized bed of clay ( FIG. 3 ). The atomizing was achieved by using a ultrasonic probe that produced a fine spray of the titanate-coupling agent directly onto the clay thus eliminating the need for any solvent. In both techniques, two levels of titanate loading were used; modified clay MC1 having modifier corresponding to 3.8% of clay weight and MC2 corresponding to 11.4% of clay weight. Nanocomposite fabrication was done by high-shear melt compounding in the microextruder ( FIGS. 1 and 2 ). 2, 5 and 7 wt. % of each clay was added to the toughened PHB-rubber system and processed for 2 minutes at 200 rpm and then injection molded into testing samples. A sample formulation with 5 wt % clay in PHB and toughened PHB matrices is given in Table 3 (Run 3).
TABLE 3 Epoxidized Maleated Run PHB rubber rubber Clay 1 100 — — 5 2 57 38 — 5 3 57 28.5 9.5 5
[0077] PHB and its blends with natural or synthetic rubber and epoxidized natural or synthetic rubber in presence and absence of compatiblizers and clays were molded into bars for impact studies, disks for morphology studies and beams for modulus measurements.
[0000] Characterization
[0078] Clay characterization: Surface elemental analysis was performed on an X-ray photoelectron spectrometer (XPS) using a Physical Electronics PHI-5400 ESCA workstation. A Thermometric Analyzer (TGA 2950, TA Instruments, DE) was used to determine the weight loss of the pristine and modified clays. These experiments were performed in platinum pans at a ramp rate of 10° C./min under a nitrogen purge flow (90 ml/min). The water contact angle for the clays were measured on a CAHN 322 microbalance (ThermoCahn, Wis.) in the wicking mode.
[0079] Thermal properties: Modulus measurements were obtained on a dynamic mechanical analyzer (2980 DMA), (TA instruments, DE) using dual cantilever mode and from −50° C. to 150° C.
[0080] Mechanical properties: Notched Impact properties of the toughened materials and their nanocomposites were measured according to ASTM D256 using a Testing Machines Inc. 43-02-01 Monitor/Impact machine with a 5 ft-lb pendulum. The samples were notched and conditioned for 48 hours before testing.
[0000] Results and Discussion
[0000] Toughened PHB
[0081] Addition of up to 40% epoxidized natural rubber alone did not affect the impact strength of PHB but on addition of 10% of maleated rubber the impact strength improved by 440% (even more than TPO) ( FIG. 4 ). The modulus of PHB was reduced by 63% by addition of ENR but only by 50% when maleated rubber and ENR were added together ( FIG. 5 ). The compatibilizer also affects the modulus of the PHB-ENR system at depressed and elevated temperatures ( FIG. 6 ). At −50° C., the modulus of PHB reduced by 63% by addition of ENR but only by 50% when maleated rubber and ENR were added together. Similar behavior was seen at room temperature (30° C.) and at 120° C. At 140° C. the modulus of the PHB-ENR-MR (288 Mpa) system is even higher that PHB (200 Mpa) possible due to crosslinking of the maleated rubber.
[0000] 6.2 Clay Modification
[0082] XPS surface profile of the pristine clay shows the presence of silicon and aluminum atoms that are integral to the clay structure. The high oxygen atom concentration on the surface is attributed to the hydroxyl groups on the hydrophilic surface. These hydroxyl groups are targeted to be exchanged with alkyl-titanate complexes from the surface modifier in the modification reaction. The XPS spectra of the modified clay show significant reduction in the atomic concentration of oxygen thus justifying the modification mechanism. The titanium and phosphorous atoms in the alkyl-titanate complex from the surface modifier are also evident in the atomic profile.
Pristine clay Modified clay-1 Modified clay-2 Carbon 20.59 33.07 35.53 Nitrogen 0.77 1.05 1.1 Oxygen 53.24 46.33 43.74 Sodium 1.64 0.82 0.87 Aluminum 6.47 5.45 4.52 Silicon 17.29 11.56 11.5 Phosphorous 0 1.3 2.03 Titanium 0 0.42 0.71
[0083] FIG. 7 is a schematic drawing of the complex in the modified clay.
[0084] The TGA weight decomposition curves also indicate the presence of surface modification in both the treated clays as indicated by the lesser weight loss until 250° C. as compared to the pristine clay. The surface modification makes the hydrophilic clay surface organophilic that can be described by an increase in the contact angle for water. The contact angle for pristine clay was measured to be close to zero as is expected for the hydrophilic surface with ample hydroxyl groups capable of interacting with water. For the modified clay, the organic groups in the alkyl-titanate complex increase the surface energy of the clay surface. This increase in the surface energy reflects in decrease in wetability and thus the contact angle increases to about 44°. Thus the clay surface has successfully been modified to make it organophilic and thus ideal for organic matrices.
Material constant (c) Cos Degrees Pristine 0.000142 0.9948 6.0 clay Modified 0.000165 0.8483 31.9 Clay-1 Modified 0.000275 0.7168 44.2 Clay-2
Nanocomposites
[0085] Toughening of PHB with ENR and maleated rubber resulted in dramatic improvement in impact properties yet the modulus and consequently the stiffness of the material reduced. The nanoclay platelets were introduced to regain the stiffness to some extent. Addition of commercially modified clay (Cloisite 30B) reduced the impact properties due to absence of coupling between the filler and the matrix and this is seen by the reduction in impact strength from 124 j/m to 50 j/m ( FIG. 8 ). But on addition of modified clay, the impact strength was regained to 117 j/m which is still 408% improvement over pure PHB and more than the impact of commercial toughened Polyolefin (TPO). In case of PHB-ENR without compatibilizer, the modulus drastically reduced possibly because the clay did not disperse but addition of coupling-agent treated clay (solvent method) improved modulus to 0.91 GPa. The modified clay provides a modulus comparable to TPO modulus ( FIG. 9 ).
[0086] The compositions of the present invention can be used in settings where a toughened polyolefin would be used, such as automotive applications.
[0087] It is intended that the foregoing description be only illustrative of the present invention and that the present invention be limited only by the hereinafter appended claims.
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Toughened compositions from polyhydroxyalkanoate (PHA), preferably PHB reactively blended with maleated poly butadiene and with an epoxidized natural or synthetic rubber are described. The compositions preferably include clay nanoparticles which can be organically modified and can be exfoliated by the blend. The compositions can be used in a variety of applications, including automotive uses.
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This is a continuation of application Ser. No. 487,273 filed July 10, 1974, now abandoned, which, in turn, is a continuation of application Ser. No. 275,830 filed July 27, 1972, now U.S. Pat. No. 3,844,488.
BACKGROUND OF THE INVENTION
The present invention relates to the preparation of waste paper stock in general, and more particularly to an apparatus for pulping and grading of waste paper to thereby produce a waste paper stock therefrom.
The recovery of pulp or stock from waste paper is well known per se. It is known that for this purpose the waste paper must be shredded in a suspension, to form from it a pulp which can be further processed. A difficulty in the preparation of stock from waste paper resides in the fact that quite often substances of low specific gravity, such as synthetic plastic foams, rubber, foils and the like are contained in the waste paper, substances which can be removed from the receptacle wherein the pulping takes place neither through the pulp outlet nor through the outlet provided for removal of heavy substances which are not intended to be used as part of the pulp. The difficulties created by this light-weight, hereafter designated for the sake of convenience as "impurities", result from the fact that such matter accumulates very rapidly in the receptacle so that after an operating period of only a few days the apparatus must be shut down to permit a complete emptying of the receptacle. It has been observed that in many instances the operating time of the apparatus, that is the time from one to the next shut-down and complete emptying of the receptacle of the apparatus, is as little as two or three consecutive days.
It goes without saying that a complete shutdown of the apparatus means lost time and increased expenses, and that this is not tolerable. The problem having been realized, the prior art has proposed to withdraw from the receptacle a partial stream of the pulped suspension, to supply it to an additional pulper or disintegrator and to a subsequent coarse grading device, and then to return it into the original receptacle. Such an approach does offer some hope of improvement, but quite evidently it also will increase the expenses involved and decrease the economy of operation of an apparatus of the type here under discussion, due to the investment costs required for the additional equipment and the increased energy requirements for operating such equipment. The problem outlined above thus has not heretofore been satisfactorily solved.
SUMMARY OF THE INVENTION
It is, accordingly, a general object of the present invention to provide an improved apparatus for pulping and grading of waste paper, which is not possessed of the disadvantages outlined above with respect to the prior art.
More particularly, it is an object of the present invention to provide such an apparatus which assures the longest possible operating period before complete emptying of the apparatus becomes necessary.
An additional object of the invention is to provide such an apparatus which is simple in its construction and reliable in its operation.
In pursuance of these objects and of others which will become apparent hereafter, one feature of the invention resides, in an apparatus for pulping and grading of waste paper, in the provision of a combination which comprises a receptacle adapted to accommodate a waste paper suspension and having a peripheral wall, and rotor means located in said receptacle adjacent one portion of said wall and being operative for shredding said waste paper in said suspension so as to obtain a pulp. First outlet means is provided in the wall in the region of the rotor for discharge of the pulp from the receptacle, and strainer means is provided for straining the pulp which is discharged through the first outlet means. In accordance with the invention there is further provided second discharge means, in another portion of the wall which is opposite the one portion and the rotor means and this second discharge means serves for discharging from the receptacle of matter having low specific gravity.
It has been found that the flow of suspension which is caused in the receptacle by the operation of the rotor causes an accumulation of the low specific gravity matter, that is the light-weight matter, in the region of the aforementioned other wall portion. If the second discharge means is provided in this region, then the accumulating light-weight matter or "impurities" will flow out through this second discharge means. It is advantageous to normally keep the second discharge means closed in order to avoid significant losses of desirable pulp matter, and to open it only briefly from time to time to permit the discharge of accumulated impurities.
It has been found that in an apparatus according to the present invention it is possible to operate the apparatus continuously for periods of several weeks before it becomes necessary to shut the apparatus down in order to empty it out completely.
According to a further concept of the invention it may be advantageous to connect the second discharge means with a suction arrangement, for instance a pump or a gravity tube, to assure that the impurities can be readily discharged from the receptacle in a simple and reliable manner even if the receptacle is of the open type, that is not of the type which is under internal overpressure.
The receptacle may further be provided in an inner surface of its peripheral wall with an annular recess which is coaxial with the axis of rotation of the rotor. In such a recess the heavy fraction of the waste paper will settle, and can then be removed by means of an appropriate outlet communicating with this recess. In such a construction both undesirable fractions, namely the light-weight impurities and the heavy-weight matter can be removed without any difficulties so that only the desirable pulp will be recovered for further use.
The rotor itself may be of such construction that the vortex flow created in the suspension by rotation of the rotor, and which extends coaxial with the axis of rotation of the rotor, will have a vortex core which extends from the rotor to the opposite wall portion of the receptacle, that is the wall portion in which the discharge means for the impurities is located. In such a construction, the vortex core is essentially centered in the receptacle and the region where the discharge for the impurities must be provided, can thus be determined precisely.
It is particularly advantageous if upstream of the receptacle there is located an additional unit also having a receptacle adapted to accommodate a waste paper suspension and being in its arrangement and its associated components -- namely the rotor means, the first outlet means and the strainer means -- essentially similar to the apparatus already outlined. The outlet for the pulp which issues from the additional receptacle then communicates with an inlet of the first-mentioned receptacle, and the strainer means should be coarser than that of the first-mentioned receptacle.
In place of the second discharge means for light-weight impurities, the second receptacle is provided in the wall portion opposite its rotor with an outlet through which tangled suspension components can be withdrawn in form of elongated rope-like wads. With such an apparatus all undesirable contaminants accommodated in or forming part of the waste paper can be largely removed, thus assuring the production of a high-grade pulp having a minimum of contaminants, and at the same time assuring a maximum length of continuous operation without downtime. The energy required for operating the first-mentioned receptacle with its associated components, that is the receptacle having the second discharge means for the light-weight impurities, is relatively small, because the rotor of this second receptacle or downstream receptacle will be required only for additional shredding of the waste paper which has already received its initial shredding in the upstream receptacle. and the desired low providing for the discharge of the light-weight impurities through the second discharge means is produced as a highly desirable incidental effect requiring no additional energy. The novel features which are considered characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, 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 DRAWING
FIG. 1 is a perspective view illustrating one embodiment of the invention;
FIG. 2 is a diagrammatic vertical section through another embodiment of the invention; and
FIG. 3 is a diagrammatic vertical section through still an additional embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Discussing now forstly FIG. 1 of the drawing it will be seen that in this embodiment there is provided an apparatus 1 in accordance with the present invention. This apparatus 1 is a part of a waste paper stock preparation plant the details of which are not illustrated because they do not form a part of the invention and are known per se. What is novel in accordance with the present invention is the apparatus 1, a pulper and grader for waste paper. The apparatus 1 has a receptacle or housing 2 which in the illustrated embodiment is substantially cylindrical in its configuration and is a closed housing. Its axis of symmetry is horizontal in this embodiment.
The housing 2 has a peripheral wall which is provided, in the region of one axial end of the receptacle 2, with a supply conduit 3 which enters substantially tangentially and supplies into the housing 2 a suspension of waste paper and a liquid, usually water. A drive shaft 5 extends into the housing through the opposite axial end wall thereof, the drive shaft 5 being adapted to be driven in rotation by a non-illustrated motive source, Mounted at or on the inner end portion of the drive shaft 5 is a rotor 6 which is itself of known construction, and, when rotated by rotation of the drive shaft 5 shreds the waste paper in the suspension in the interior of the housing 2 and forces the thus obtained pulp through a screen 7 and subsequently into a collecting chamber 8 from which the pulp enters into an outlet 9. The circumferential wall of the housing 2 is provided in this embodiment with an annular recess 10 with which an outlet 11 communicates.
The axial end of the housing 2 which is opposite that end at which the rotor 6 is located, is provided with an outlet 4, and in the illustrated embodiment the axis of rotation of the rotor 6 and the longitudinal axis of the outlet 4 are coincident.
Rotation of the rotor 6 causes in the suspension accommodated in the housing 2 a flow pattern which is indicated by the arrows of FIG. 1. It is clear that the suspension entering into the housing 2 from the tangentially discharging inlet conduit 3 is given a flow direction in the region of the end wall where the inlet 3 discharges, which causes it to flow in axial direction longitudinally of the axis of rotation of the rotor 6 and towards the latter. The pulp or stock which results from shredding of the waste paper in the suspension by the rotor 6 is forced by the rotor through the screen or strainer 7 to subsequently enter the outlet 9. Those suspension components which have not been sufficiently shredded to pass through the strainer 7 flow substantially along the circumferential wall of the housing 2 back to the end wall in the region of which the inlet 3 discharges the newly incoming suspension.
heavy suspension components, for instance metallic contaminants in the suspension, will settle in the recess 10. light-weight components or impurities, for instance synthetic plastic foam, rubber or the like, accumulate in the region of the end wall provided with the outlet 4 and leave the housing 2 through the latter. Advantageously the outlet 4 is provided with a closing device, for instance a known valve or the like, not shown, which normally closes the outlet 4 and which is opened only from time to time to permit the removal of accumulated light-weight contaminants or impurities without resulting in the loss of a substantial amount of pulp or useable waste paper.
It will be understood that the rotation of the rotor 6 causes a vortex flow which extends axially along the axis of rotation of the rotor 6 to the end wall provided with the outlet 4. The flow has a vortex core centered on the one hand by the construction of the rotor 6 and on the other hand by the housing wall, so that the location for the outlet 4 can be precisely determined in conjunction with the readily calculable manner in which the light-weight impurities will be ejected from the vortex core.
In FIG. 2 I have illustrated an embodiment which is quite similar to that of FIG. 1 except that the housing 2' is open, rather than closed as the housing 2 in FIG. 1. In FIG. 2, components similar to those of FIG. 1, have been given the same reference numerals but with a prime suffix. A conduit 18 communicates with that end wall of the housing 2' which is axially spaced from the rotor 6', the latter being mounted on the drive shaft 5' which here is shown as being connected with the drive means 5", the latter being diagrammatically illustrated and representative of an electric motor or the like.
The purpose of the conduit 18 is to permit the withdrawal of rope-like wads 29 of tangling components of the suspension. The formation of such wads is well known and they can be withdrawn by means of the withdrawal rollers 30, 30 shown in FIG. 2, one or both of which may be driven for this purpose.
An outlet conduit 4', corresponding to the outlet 4 of FIg. 1, communicates with the conduit 18 for the withdrawal of the light-weight impurities from the interior of the housing 2'. In the embodiment of FIg. 2, the conduit 4' has interposed in it a suction means, here illustrated in form of pump P. although it is possible to replace the pump P by constructing the outlet conduit 4' itself as a gravity tube in which suction is created by the gravity descent of matter in the tube. The outlet 11' is here provided with a slide valve 11" for controlling the outflow of matter.
Reference numeral 23 designates in this embodiment a bail of waste paper to be shredded and reference numeral 24 designates an inlet conduit for liquid.
FIG. 3, finally, illustrates still a further embodiment of the invention. Here, there is provided an apparatus 1 which is essentially the same as that shown in FIG. 1, but which operates in conjunction with an apparatus 21 resembling essentially (but with some modifications) the apparatus of FIG. 2. In particular, like components are identified with like reference numerals as in the preceding embodiments to the extent possible without producing confusion.
In FIG. 3 the apparatus 21 has a housing 22 or a receptacle, which is open at the top, and into which unless 23 of waste paper to be pulped are introduced. Reference numeral 24 designates an inlet conduit for admission of liquid in which the paper is to be suspended.
One side wall of the housing 22 has a drive shaft 25 of a drive 25' passing therethrough, carrying at the inner end located within the housing 22 a rotor 26 which may be similar to the one shown in FIG. 1. The rotor 26 again serves for shredding of the waste paper which circulates in suspension in the housing 22, and for forcing the shredded waste paper in form of pulp through the screen 27 into the chamber 33 from where it passes into the inlet conduit 3 of the housing 2 of the apparatus 1 which is located downstream with respect to the apparatus 21. Clearly it is not necessary that the apparatus 1 be located physically at a lower lever than the apparatus 21 but it must be kept in mind that the apparatus 1 is to be located downstream of the apparatus 21, that is it must receive pulp from the latter.
The wall of the housing 22 which is located oppositely to and spaced from the rotor 26 is provided with a conduit 28 whose purpose is the same as the conduit 18 in FIG. 2, namely to permit withdrawal of a rope-like wad 29 of tangling matter which is part of the bales 23 of incoming waste paper. The wad 29 is withdrawn by the withdrawing arrangement 30 which is the same as that in FIG. 2.
The bottom wall of the housing 22 is provided with an outlet conduit 31 through which heavy fractions of the suspension, for instance, metallic parts or the like, can be withdrawn after settling at the bottom. The outflow of matter through the outlet conduit 31 is controlled by a slide valve 32 which is operated by a diagrammatically illustrated arrangement, and which is opened from time to time to permit the issuance of the accumulated heavy matter.
The apparatus 1 is essentially the same as that illustrated in FIG. 1, except that as shown in FIG. 3, the apparatus 1 is turned end for end with respect to the showing in FIG. 1. It is emphasized that although the housing 2 of the apparatus 1 in FIG. 3 is closed, as is the case in FIG. 1 also, the housing could be open as is the housing 22 of the apparatus 21. The screen 27 is coarser -- that is of larger mesh -- than the screen 7 of the apparatus 1 so that pre-pulping takes place in the apparatus 21 and final pulping in the apparatus 1. As in the embodiment of FIG. 1, the flow is illustrated with the arrows in the housing 2 of the apparatus 1 and it will be seen that the impurities of light-specific gravity are shown as tending to accumulate in the region of the axial end wall which is remote from the rotor 6, that is in the region where the outlet 4 is provided. In FIG. 3 I have shown that the outlet 4 can be normally closed by means of a slide valve 4" and can be opened from time to time to permit withdrawal of the accumulated light-weight impurities, for instance by means of the diagrammatically illustrated pump P. Maintaining the outlet 4 normally closed prevents the loss of desirable matter, that is of pulp or the like. The circumferential recess 10 resembles the one illustrated in FIG. 1 and is provided for the same purpose. Its outlet 11' is closed by a slide valve 11", which is normally closed and can be opened from time to time to permit the removal of accumulated heavy matter. The control of the movements of the slide valves 4" and 11' is effected by the diagrammatically illustrated devices which do not form a part of the invention and require no further detailed discussion.
Due to the fact that the mesh size of the screen or strainer 27 of the apparatus 21 is relatively large, between substantially 14 and 25 mm. with respect to substantially 4-14 mm. for the screen 7 of the apparatus 1. the light-weight impurities can leave the apparatus 21 together with the pulp. This prevents the light-weight impurities from blocking the apparatus 21 after a relatively short period of operation. The tangling components, however, are almost completely removed to form of the wad 29 so that the suspension as it enters the apparatus 1 contains almost no such components. On the other hand, the light-weight impurities are almost completely removed in the apparatus 1, so that they cannot accumulate therein and do not necessitate the shutting-down of the apparatus except after periods of operation which may last as long as several weeks.
With the embodiment in FIG. 3, the volumetric content of the housing 2 of the apparatus 1 can be substantially smaller than that of the housing 22 of the apparatus 21. Practical tests have shown that a size ratio of 10:1 for the apparatus 21 versus the apparatus 1 is possible, and it has been determined that a volumetric content of between 20-40 m 3 for the apparatus 21 and of about 3.5 m 3 for the apparatus 1 are advantageous.
It will be seen that with the present invention the difficulties of the prior art have been overcome and the objects outlined herein have been attained. It is now possible to operate an apparatus according to the present invention for periods of several weeks without having to shut it down in order to remove accumulated light-weight impurities from the housing or receptacle. Evidently, this not only results in a saving in down-time, but also in a generally more economic operation of the apparatus.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in an apparatus for pulping and grading of waste paper, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
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A receptacle accommodates a waste paper suspension and a rotor located adjacent one portion of the receptacle wall. A first outlet is provided in the wall in the region of the rotor so that pulp produced by shredding of waste paper by the rotor can be discharged from the receptacle. A strainer is interposed in the first outlet, and a second outlet is provided in an opposite portion of the wall and arranged to discharge matter having low specific gravity from the receptacle.
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BACKGROUND OF INVENTION
The present invention relates to a battery with on-board load leveling and, more particularly, to the integration of at least a battery with at least a supercapacitor and miniaturized electronic controllers within a single housing, wherein the supercapacitor provides load leveling to the battery at charging and discharging.
Batteries are indispensable in the modern life. From automobiles and cellular to lap tops and PDA″s, the devices will not perform without batteries. Batteries are generally categorized as primary batteries that offer only one time of use, and secondary batteries that can be reused through electrically recharging in a number of cycles. As chemical reactions coupled with structural alteration are involved in the energy transfer of batteries, they are all limited in the rates of charge and discharge, as well as the depth of discharge. High power density and rapid recharge-ability are thus two goals in the incessant developing endeavors for batteries.
On the contrary, although capacitors have superior power density, depth of discharge, and recharge-ability than battery for the energy transfer occur only on the electrode surface of capacitors. Nevertheless, as the bulk of electrodes is not utilized for storing energy capacitors have an inferior energy density than batteries. To improve the energy density thus becomes the major developing target for capacitors. Obviously, an ideal energy-storage device should combine the advantageous qualities of both batteries and capacitors. Just like lead acid battery has the greatest power density among commonly used batteries including Ni—Cd, Ni—MH, Li, and Zn—air, supercapacitor has the highest volumetric energy density among all capacitors including ceramic, plastic film, aluminum electrolytic, tantalum, glass, and mica capacitors. Because of its high energy content, supercapacitor is capable of delivering and receiving currents up to hundreds of Ampere that impart the capacitor practical values to provide load leveling to batteries and fuel cells for power applications.
It is a paradox for an energy-storage device to simultaneously possess both of high energy density and high power density. As high energy density requires thick electrodes, whereas thin electrodes are needed for high power density. The device can be achieved only when a material with nanometer dimensions and a high energy capacity together with an implementing method, which can exactly convert the material into electrodes without losing the distinctive characters of the material, can be established. Otherwise the ideal energy-storage device is hardly attainable. While enthusiastic endeavors are dedicated to the discovery of the aforementioned material and method, there are hybrid designs proclaimed for enhancing the energy capacity and/or the energy efficiency of batteries and capacitors. In U.S. Pat. Nos. 4,959,281, 6,088,217, 6,222,723, and 6,252,762, also reports by Drews et al. “High-rate lithium/manganese dioxide batteries; the double cell concept”, J. Power Sources, vol. 65, pp 129–132, 1997, and by Arbizzani et al., “New trends in electrochemical supercapacitors”, J. Power Sources, vol. 100, pp 164–170, 2001, as well as by Pasquier et al. “A Nonaqueous Asymmetric Hybrid Li 4 Ti 5 O 12 /Poly (fluorophenylthiophene) Energy Storage Device”, J. Electrochem. Soc., vol. 149, no. 3, pp A302–A306, 2002, wherein a battery electrode is used as anode and a supercapacitor electrode as cathode to construct hybrid devices. By properly selecting the hybrid pairs, it is said that the energy density of an asymmetric supercapacitor is increased by six times as stated in U.S. Pat. No. 6,222,723. Even with 10-fold augmentation in the energy density of supercapacitor, its energy content is still tiny in comparison to that stored in batteries. In addition, neither the battery electrode can be protected against over-charge and over-discharge by the capacitor electrode, nor can the capacitor electrode completely utilize all the increased energy for providing peak currents as the reaction on the battery electrode is slow as usual. There is no practical gain in the asymmetric devices.
It is known in the art that batteries should have protection mechanisms and electronic circuits against high internal pressure, run-away temperature, inverse polarity, over-charge, and over-discharge. Normally, batteries and their protection means are two separate identities in different packages. However, for fast and precise performance, mechanics and electronics are now being integrated into a single device known as mechatronics that can be found in products such as computer disk drive, dryer, air bag, CD/DVD player, and automobile braking system. Such concept has been applied to the construction of integrated batteries as well. U.S. Pat. Nos. 4,622,507, 5,644,207, 5,645,949, 6,020,082 and 6,163,131 all disclose the integration of batteries with control circuits in a single housing. They are incorporated herein by references in their entirety. By placing the controllers by the batteries within a single casing can provide a number of advantages including fewer connecting cables used, close monitoring, EMI (electromagnetic interference) shielding, and real-time response. An electronic controller should modulate at least the following four key functions of batteries: 1) use time, 2) power output, 3)recharge time, and 4)safety. The first two functions relate to the discharge of batteries on driving various loads. U.S. Pat. No. 6,163,131 has allocated one-quarter of its entire content to a discharge sub-controller wherein the energy utilization of batteries is enhanced via safe deeper discharge. In essence, using electronic controllers alone for improving the qualities of batteries is a passive approach. Though the electronic controllers can protect the batteries from damages due to excessive charge and discharge, the circuits merely regulate and guide the batteries to execute energy transfer under some predetermined levels. On one hand, the controllers contain no energy to help batteries to meet great power demands, on the other the controllers can not assist batteries to receive large energy as generated in the regenerative braking of electrical vehicles. The controllers just block excessive energies instead of retrieval. To provide a realtime load leveling and to save all available energies, the present invention integrate batteries, supercapacitors and electronic controllers within a single housing.
SUMMARY OF INVENTION
The invention provides a supercapacitor, which is an energy storage device with the same electric characteristics as capacitor, and yet it stores much more energy than the conventional capacitors. As long as the rated voltage of capacitor is complied, supercapacitor can accept charging currents of any magnitude and store the energy quickly. On releasing the stored energy, supercapacitor can robustly deliver peak currents with tens thousands of cycle-life and more than 99% depth of discharge. Therefore, supercapacitor is energetic and reliable for power applications, and it is a universal element for actively improving the energy qualities of batteries and fuel cells.
In accordance with the unique properties of supercapacitor, an object of the invention is to use the capacitor as an in-cell load leveling element for batteries and fuel cells. Regardless of the load demands, the batteries integrated are set to discharge at 1C or lower rates, and the supercapacitor will provide the extra power needs. As the batteries always discharge at low currents, their use time and lifetime will be extended.
Another object of the invention is to increase the utilization of the allowable energy stored in batteries. Near the end of the discharge cycle of batteries, their residual energy is often insufficient to drive many loads. However, the residual energy can become potent and useful after being boosted by supercapacitor. With the assistance of supercapacitor, the residual energy of batteries is safely drained.
Yet another object of the invention is to use supercapacitor as a buffer or equalizer for the electrical charging of batteries. The capacitor is first charged by external power sources that provide miscellaneous charging currents at voltages below the nominal operating potential of capacitor, then the capacitor transfers its stored energy to the batteries following the charging protocols of batteries. By the foregoing algorithm, all available energies are saved, batteries are protected from excessive charging currents, and battery charging is expedited because of energy equalization provided by supercapacitor.
Still another object of the invention is to simplify the controlling or protecting circuits of batteries by using supercapacitor for energy management. Supercapacitor performs both as an energy device and an electronic component. Because of moderately high energy density and high power density of supercapacitor, some DC-DC converters and step-up circuits can be saved or minimized.
A further object of the invention is the incorporation of battery and supercapacitor within a single housing. Since both devices share a number of similarities in the electrolyte system and in manufacturing procedures and equipments, they are easy to be made in one package without the problem of cross contamination. Combining the strength of the battery and supercapacitor, the hybrid device attains a synergistic effect as the two elements are electrically integrated.
A still further object of the invention is provision of powers to actuate micro fans installed inside metal-air batteries, or to turn on a heating element in fuel cells such as proton exchange fuel cell (PEFC), for initiating the operation of the air-driven energy apparatus. Both apparatus can attain longer use time and higher power density with the assistance of load leveling provided by supercapacitor.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,
FIG. 1 is a cylindrical integrated-battery containing battery, supercapacitor, and microprocessor within a single housing, according to one preferred embodiment of this invention;
FIG. 2 is a simplified diagram showing battery and supercapacitor are connected in parallel by a charge sub-controller and a discharge sub-controller, according to one preferred embodiment of this invention;
FIG. 2A elaborates the circuitry of charge sub-controller that regulates the electrical charging of battery and supercapacitor, according to one preferred embodiment of this invention;
FIG. 2B elaborates the circuitry of discharge sub-controller that governs the energy output provided collectively by battery and supercapacitor, according to one preferred embodiment of this invention;
FIG. 3 is a detailed layout of the charge and discharge sub-controllers shown in FIG. 2 , according to one preferred embodiment of this invention; and
FIG. 4 is a multi-cell zinc-air battery consisting of an in-cell air management that is actuated by supercapacitor (not shown), according to one preferred embodiment of this invention.
DETAILED DESCRIPTION
An integrated battery is a smart battery that has on-board electronic circuits and complementary devices to allow the battery taking heavy-duty loads without over-discharge or over-charge. Battery and supercapacitor are electrochemical cells for storing energy in different mechanisms. Bulk chemical reactions are evolved in battery wherein electrical energy is converted to chemical energy at charging, and the reverse process occurs at discharge. In contrary, the energy transfer at charge and discharge of supercapacitor is more a physical process than a chemical reaction. Regardless of the mechanistic difference, batteries and supercapacitors can be manufactured using the same production procedures and equipments. However, supercapacitors can use identical electrodes as anode and cathode, their fabrication is more flexible and economical than that of batteries. The latter must use asymmetric electrodes. As both devices can use the same electrolyte system, it is easy to integrate battery and supercapacitor into a single device. Inclusion of supercapacitors adds no significant increment to the production cost of batteries.
FIG. 1 shows one preferred embodiment of incorporating rechargeable battery element LI/B 110 , supercapacitor element S/C 112 , and microprocessor 103 within a single housing of cylindrical shape 104 to form the integrated battery 100 . There are four communication buses, 106 , two for each element, between microprocessor 103 and rechargeable battery LI/B 110 , as well as between 103 and supercapacitor S/C 112 . Battery 100 has positive and negative terminals indicated by 101 and 102 , respectively, on the exterior of housing 104 . The communication bus 106 allows LI/B 110 and S/C 112 to perform complementary actions to each other through microprocessor 103 , while insulator 105 provides hermetic seal to the components within the housing 104 . Both ends of supercapacitor S/C 112 are further sealed with an edge sealer 107 so that S/C 112 can be bipolar and isolated from other components in the housing. A bipolar design has at least three electrodes with the middle one serving as anode and cathode simultaneously. As a matter of fact, a bipolar cell is a device that contains two cells or more in series connection without connecting cables. The open cell voltage of a bipolar cell is the sum of the voltages of cells constituting the bipolar device. Nevertheless, the electrolyte must remain in each cell and that is the main reason why edge sealer 107 is used. The dimension and capacity of supercapacitor S/C 112 relative to that of rechargeable battery LI/B 110 can be custom-made according to application needs.
Practically, all electrolytes employed for batteries or fuel cells are applicable to supercapacitor. For example, electrolytes (in parenthesis) for primary batteries such as Zn/MnO 2 (KOH), Zn/Ag 2 O(KOH), and Zn/air (KOH), electrolytes for secondary batteries as in lead-acid (H 2 SO 4 ), nickel-cadmium (KOH), nickel-metal hydride (KOH) and lithium ion (salt in organic solvent such as propylene carbonate (PC)), polymeric electrolyte in lithium polymer batteries, also electrolyte for PEFC (H 3 PO 4 ), all have been proved to work for supercapacitor. Particularly, PC, a frequently utilized solvent for lithium ion batteries, is also a common solvent for supercapacitor. Other suitable solvents, for example, can be used for both battery and supercapacitor include acetonitrile, ethylene carbonate, diethyl carbonate, and dimethyl carbonate. Though LiPF 6 is the common salt for Li ion batteries and (C 2 H 5 ) 4 NBF 4 for supercapacitors, it is the solvent that causes cross contamination. In other words, battery LI/B 110 and supercapacitor S/C 112 in FIG. 1 are truly compatible. When S/C 112 is a bipolar device composing of three electrodes and an organic electrolyte, it will have a nominal working potential of 5V that is close to the open circuit voltage of lithium ion batteries, that is 4.2V. As a matter of fact, the cell voltage of supercapacitor can be made to match that of battery via bipolar configuration in small volume.
In another preferred embodiment, the integration of battery and supercapacitor is by stacking the electrode plates of both devices into a housing or a package of prismatic shape. Not only the stacking arrangement provides easier cell assembly than spiral winding as shown in FIG. 1 , it also allows multi-cell battery and multi-cell supercapacitor to be gathered within a single housing. There are four kinds of material for constructing the electrodes of supercapacitor : 1)carbons, 2)metal oxides, 3)conductive polymers, and 4) a composite in various combinations of the foregoing three. With different materials as the active layer of electrodes, the resulting capacitors will have different electrical characteristics. Hence, supercapacitor, ultracapacitor, and electric double layer capacitor are the most common names given to the high-capacity (≧0.15F/cm 2 ) capacitors ad hoc. Except the conducting polymer, the present invention has tested the other three on providing load leveling to batteries, and the results are satisfactory. It is primarily the cost of material and fabrication that decides which active material should be utilized to implement the invention.
In addition to the cost of supercapacitor related to the commercial viability of the integrated battery of the present invention, the price of the enclosed electronic controller is also a critical factor. FIG. 2 is a preferred embodiment showing a block diagram of an on-board controller 200 for guiding the compensatory actions between battery LI/B 110 and supercapacitor S/C 112 . Inside the housing 201 , the controller is consisted of a charge sub-controller (C) 205 and a discharge sub-controller (D) 206 for governing energy supplied through diode 204 from an input such as an AC or a DC power source, as well as for governing energy output to loads. When there is no external energy, battery LI/B provides energy with voltage adjustment, for example, 4.2V or lower is stepped up to 5.0V, by the charge sub-controller C through communication bus 202 and 203 to charge supercapacitor S/C. Battery LI/B is pry-set to discharge at no more than 1 C. 1 C rate means that the allowable energy of batteries is drained in 1 hour. If there exists a power difference between a power demanded by a load and that provided by the LI/B, it can be supplemented by a provision of supercapacitor S/C via the modulation of discharge sub-controller D.
Now, the topology of charge sub-controller C and discharge sub-controller D is explained in FIGS. 2A and 2B , respectively. FIG. 2A shows charge sub-controller C consisting of a micro-controller (μC 1 ) denoted as 217 and three switches, SW 1 ( 219 ), SW 2 ( 221 ), and SW 3 ( 223 ), of MOSFET (metal oxide semiconductor field effect transistor) type encased in the housing 211 . During charging, a charging current is supplied by an external power source to point IN, which is regulated by micro-controller 217 through switches 219 and 221 also communication buses 215 , 225 , and 227 to primarily charge supercapacitor S/C 112 to its nominal cell voltage. Within the forgoing voltage, S/C 112 can accept charging currents of a magnitude up to hundreds of Ampere. Hence, even as large as the currents generated in the regenerative braking systems of trucks can be conserved and re-used by employing supercapacitor as load leveling for the integrated battery. Once S/C 112 is fully charged and battery LI/B 110 is detected low in energy content, S/C 112 will supply energy under the command of micro-controller 217 via bus 227 and bus 215 , switch 223 into bus 213 to charge LI/B 110 . A double arrow is included in 223 to indicate a two-way charging between S/C and LI/B. If necessary, the charging sequence will be repeated until both S/C 112 and LI/B 110 are fully charged. By then, the charge sub-controller C will automatically disconnect the integrated battery from the external power source.
Next, the discharge sub-controller D is illustrated in FIG. 2B wherein a micro-controller, (μC 2 ) or 214 , and two switches, SW 4 ( 222 ) and SW 5 ( 224 ), of MOSFET type are utilized to regulate battery LI/B and supercapacitor S/C on providing energy to the output of housing 212 . During discharging, it is LI/B that primarily supplies energy to S/C via switch 223 in FIG. 2A and loads under a total discharge rate not exceeding a predetermined level, for example, 1C. When loads demand a power more than 1C discharge rate can furnish, switches 222 and 224 will be proportionally opened at the command of micro-controller 214 according to power apportion on communication bus 216 and 220 . No matter how heavy the load is, LI/B is always discharged at a safe level that does not cause significant IR drop at the battery so that the use time and cycle life of battery can be extended. Furthermore, so long as LI/B has not decayed below its cut-off voltage, the residual energy of LI/B may be converted by the PWM (pulse width modulation) 218 of S/C to accomplish some finale such as sending a message by cellular or saving data of a lap-top. By safely extracting the last bit of the battery power, the energy efficiency of LI/B is enhanced. Finally, combining charge sub-controller C and discharge sub-controller D forms the entire picture of the on-board controller 300 in the housing 301 as shown in FIG. 3 . Same reference numbers as in FIGS. 2A and 2B are ensued for the identical components in FIG. 3 . In essence, the two micro-controllers 217 and 214 are two constituent parts of the micro-controller 304 . Two phantom lines are used to indicate the foregoing relationship in FIG. 3 . Communication bus 302 and 303 are responsible for detecting cell voltages of both LI/B and S/C during charging.
Supercapacitor is utilized as a built-in load leveling for primary and secondary batteries in the above discussion. There are other important energy devices that may solve our energy need particularly in the future, for example, metal-air batteries and fuel cells. This type of apparatus can carry a large reservoir of fuel such as metal fuel or hydrogen gas, technically, they can offer an indefinite service run time. Another unique feature of the air-driven devices is that they depend on an air cathode for their chemical reactions to generate electricity. Using air as reactant has the advantages of free material, inexhaustible source and indefinite shelf life attainable by completely closing the air intake by the devices. Nevertheless, metal-air batteries require power to resume the air flow, while fuel cells demand power for heating the various kinds of equipment to their operating temperatures. Apparently, metal-air batteries and fuel cells can be equipped with an on-board load leveling to provide the aforementioned needs. FIG. 4 shows a multi-cell zinc-air battery 400 containing an in-cell air management. As discussed above, integration of supercapacitor in the stacking arrangement is completed simply by adding the electrode plates of supercapacitor (not shown in FIG. 4 ) to the battery stack 401 formed by the battery plates 402 . As seen in FIG. 4 , a number of protruding dots are printed on spacers disposed against the (air) cathode plates to create air channels 403 . There are a number of air inlets 405 , as well as two micro fans or micro pumps 404 , atop both caps 406 a and 406 b of the hybrid battery 400 . It is also easy to conceal a controller as depicted by FIG. 3 inside the housing of 400 (both controller and housing are not shown in FIG. 4 for clearance).
The aforementioned micro fans 404 of FIG. 4 can be fabricated by LIGA (German acronym for Lithographe, Galvanoformung, und Abformung) technique. To make the micro fans to work, there should have a bending element and at least one force element. Several materials available for constructing the bending element that include single crystal silicon (such as silicon wafer) or an electroactive polymer (EAP) diaphragm. While the force element may be made of a piezoelectric crystal (such as zinc oxide), a magonestrictive alloy (such as terbium-dysprosium-iron), or a thermally dependent film (such as aluminum). Mechanically, the force element is attached to the bending element. When a voltage is applied to the force element, it will induce a physical change such as the length change of the element. Such change of the force element will cause the bending diaphragm to flex inward or outward depending on the location of the force element. Through the foregoing flexing motion of the bending element, an air draft will be developed through a check valve of the micro fans in the zinc-air battery 400 of FIG. 4 . Air intake of the battery depends on the voltage applied to the force element. When there is enough room inside the housings of metal-air batteries or fuel cells, a micro rotary fan or blower may be used as micro fans 404 to replace the bending diaphragm for drawing air into the air-dependent devices. Regardless of which design is selected, the mechanical unit is secured at the middle region of the first cap 406 a and the second cap 406 b of battery 400 . Furthermore, the micro fans 404 at the both ends of battery 400 are arranged to flex or rotate in opposite direction so that air draft is created in the air pathways 403 . To impart high power density to metal-air batteries and fuel cells, the flow rate of air in the devices is preferably greater than 10 me/min, and the power consumption of micro fans 404 is preferably smaller than 0.5W. Supercapacitor works with a non-air cell that may be constituted by a metal anode including Zn, Al, Mg and Fe and a cathode selected from NiOOH, MnO 2 or Ag 2 O to supply the power required for actuating the micro fans. In the foregoing arrangement, supercapacitor provides a load leveling for the non-air cells so that the power output of the latter can be boosted. Similar combination of non-air cell and supercapacitor may also be encased within the housings of fuel cells to supply power to a heating element, for example, a Ni—Cr resistor or PTC, to generate the operating temperatures for driving the fuel cells.
To demonstrate the load-leveling capability of supercapacitor, the following example is provided.
EXAMPLE
A multi-cell alkaline battery using Zn metal as anode, MnO 2 as cathode and an aqueous KOH solution as electrolyte is constructed to have an open-circuit voltage of 9V and 1.5 Ah capacity. Then, two supercapacitors, which use Fe 3 O 4 /carbon composite as active material for the electrodes and aqueous KOH solution as electrolyte, connected in parallel with each piece having an open circuit voltage of 7.5V, 6F capacitance, and 40 m ΩESR (equivalent series resistance) are provided for being integrated with the alkaline battery and an electronic controller within a single container. Right at the moment of power demand, the controller can convert the supercapacitors into series connection. It is measured that the hybrid device is capable of providing a peak power of 15V×25A or 375W that is good enough for driving various power tools. Without the supercapacitor, the alkaline battery can only deliver 13.5W (9V×1.5A) at 1C discharge rate. Clearly, the supercapacitor has boosted the power output of the battery by 27 times. The load leveling furnished to the battery by the supercapacitors is evident and practical.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention covers modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
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An integrated battery by incorporating battery elements, supercapscitors elements, and miniaturized electronic controllers within a single housing is devised. The supercapacitors provide a load leveling for the battery elements at both charging and discharging. So long as the rated working voltage of supercapacitor is complied, the capacitor can be charged with charging currents of any magnitude. Then, the energy stored in the supercapacitors can be transferred from the capacitors to the batteries resulted in fast charging and energy conservation. With load leveling provided by the supercapacitors, the batteries are set to constantly discharge at 1C or lower rates and their residual energy near the end of discharge cycle can become useful as well. Therefore, the service run time, cycle life, and energy utilization of the batteries integrated are improved. In addition, the supercapacitor can be a built-in actuator to provide powers to in-cell air management systems for generating air draft inside metal-air batteries and fuel cells to increase their shelf life and power density.
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BACKGROUND OF THE INVENTION
The present invention relates to a novel oxide garnet single. crystal or, more particularly, to a rare earth-based oxide garnet single crystal having improved light absorption characteristics in the 1.55 μm wavelength band and outstandingly small saturation magnetization and useful as a functional element in various magneto-optical devices such as optical isolators, optical switches and the like, which enables a more compact design of the devices.
Single crystals of a bismuth-substituted rare earth-iron oxide garnet are well known materials to serve as a functional element in various kinds of magneto-optical devices such as optical isolators, optical switches and the like and they are conventionally prepared by the method of epitaxial growth on the substrate of a certain single crystalline material. As a consequence of the epitaxial growing method, it is almost unavoidable that the rare earth-based oxide garnet single crystals as grown are contaminated with various kinds of contaminants including, for example, lead ions originating from the lead oxide used as a constituent of the flux of the melt and platinum ions originating from the material of the crucible used in the liquid epitaxial growing method. These contaminants are of course very detrimental against the performance of the single crystals as a functional element of magneto-optical devices. When the oxide garnet single crystal is used as an element in an optical isolator, for example, the absorption of light in the working wavelengths of 0.8 μm, 1.3 μm and 1.55 μm is more or less increased by these contaminants resulting in an increased insertion loss.
In consideration of these problems, a proposal has been made to introduce a very trace amount of divalent or tetravalent metallic ions such as Ca 2+ , Mg 2+ , Ti 4+ and the like into the oxide garnet single crystals of this type (see, for example, The 11th Japan Applied Magnetics Society, Preprints for Scientific Lectures, November 1987, 2C-10, page 137). This method has another problem that, while the rare earth-based oxide garnet single crystals as epitaxially grown are required to have a thickness of at least 50 μm, introduction of the above mentioned metallic ions thereinto causes variation in the chemical composition of the oxide garnet layer during the epitaxial growing to destroy the uniformity in the performance of the single crystal-based devices.
Alternatively, Japanese Patent Publication No. 5-13916 teaches that the above mentioned problem can be solved with an epitaxially grown oxide garnet single crystal having a chemical composition expressed by the formula
(Bi.sub.0.26 Eu.sub.0.07 Tb.sub.0.67).sub.3 (Fe.sub.0.94 Ga0.06).sub.5 O.sub.12.
Although this oxide garnet single crystal has good magneto-optical characteristics in the 1.3 μm wavelength band, the light absorption loss in the 1.55 μm wavelength band is increased due to the influence of the light absorption by the terbium ions in the longer wavelength region so that, for example, magneto-optical devices such as optical isolators prepared by using such a single crystal suffer from an increased insertion loss when they are to be used in the 1.55 μm wavelength band.
Further alternatively, Japanese Patent Kokai No. 2-77719 proposes a magneto-optical oxide garnet single crystal suitable for temperature compensation, which has a chemical composition expressed by the general formula Ho 3-x-y Gd x Bi y Fe 5-z Ga z O 12 , in which x is a positive number of 0.8 to 1.2, y is a positive number of 0.7 to 1.2 and z is a positive number of 1.2 to 1.7. As a consequence of the substitution of the so large amount of gallium as a non-magnetic element for iron as the magnetic element, the Faraday rotation coefficient thereof is so small as to be about 590 degrees/cm for the light of a wavelength of 1.55 μm as is shown in the Examples so that such an epitaxially grown garnet film cannot be used alone in a Faraday rotation device such as optical isolators unless the film thickness of the garnet film is unduly large. Needless to say, such a garnet film having a sufficiently large thickness can be obtained only by a substantial extension of the time taken for the epitaxial growth of the garnet film naturally with a disadvantage in the production costs.
Still alternatively, Japanese Patent Kokai No. 3-280012 proposes a magneto-optical material which is a magnetic oxide garnet single crystal film having a chemical composition expressed by the formula Ho 3-u-v Gd u Bi v Fe 5 O 12 , in which u and v are each zero or a positive number smaller than 3 with the proviso that u+v does not exceed 3. A problem in the garnet single crystals of this type is that, when the content of gadolinium is so small as in the garnet of the formula Ho 1 .45 Gd 0 .25 Bi 1 .30 Fe 5 O 12 shown in the Examples, the magnetic saturation thereof is as large as about 1000 G so that a magneto-optical device such as optical isolators prepared with such a garnet single crystal can work only by using an unduly large magnet generating a magnetic field strong enough.
SUMMARY OF THE INVENTION
The present invention accordingly has an object to provide a novel and improved epitaxially grown single crystal of a rare earth-based oxide garnet free from the above described problems and disadvantages in the conventional oxide garnet single crystals of the similar types.
Thus, the invention provides an epitaxially grown single crystal of a rare earth-based oxide garnet having a chemical composition represented by the general formula
Gd.sub.a Ho.sub.b Eu.sub.d Bi.sub.3-a-b-d Fe.sub.5-c M.sub.c O.sub.12, (I)
in which M is an element or a combination of elements selected from the group consisting of aluminum, scandium, gallium and indium, the subscript a is a positive number in the range from 1.1 to 2.1 or, preferably, from 1.2 to 1.6, the subscript b is a positive number in the range from 0.1 to 0.9 or, preferably, from 0.6 to 0.9, the subscript c is 0 or a positive number not exceeding 0.5 and the subscript d is zero or a positive number not exceeding 0.6 with the proviso that 3-a-b-d is in the range from 0.7 to 1.2 or, preferably, from 0.7 to 1.1.
The value of the subscript d, which defines the content of europium, can be zero in the garnet composition but introduction of a substantial amount of europium, for example, corresponding to the value d of at least 0.03 has an effect of greatly decreasing the light absorption.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As is understood from the above given description, the oxide garnet single crystal of the invention has a chemical composition represented by the general formula (I) given above, which is, when the subscript d is zero, analogous to the formula disclosed in Japanese Patent Kokai No. 2-77719 excepting for the omission or decrease of the amount of gallium which partially substitute for the iron although the atomic ratio of gadolinium, holmium and bismuth overlaps with that taught in the prior art.
In particular, it has been unexpectedly discovered that incorporation of europium in an amount corresponding to the value of the subscript d of 0.03 to 0.6 is advantageous in respect of the decrease in the light absorption.
The above defined rare earth-based oxide garnet single crystal is obtained by the method of liquid epitaxial growth on a single crystal substrate. Namely, the epitaxial growth of the oxide garnet single crystal proceeds on a substrate surface from a melt of an oxide mixture consisting of oxides of the respective elements containing flux materials such as lead oxide and boron oxide.
The above mentioned substrate is a single crystal plate of a rare earth-based garnet such as the samarium-gallium garnet, referred to as SGG hereinafter, neodymium-gallium garnet, referred to as NGG hereinafter, gadolinium-gallium garnet, referred to as GGG hereinafter, and the like, optionally, doped with a limited amount of a dopant such as calcium, magnesium, zirconium, yttrium and the like sold under the tradenames of SOG, NOG and others by Shin-Etsu Chemical Co., Ltd., Japan. These rare earth-based garnet single crystals can be prepared by the so-called Czochralski method in which a single crystal boule is pulled up from a melt of the oxide mixture consisting of gallium oxide and gadolinium oxide, samarium oxide or neodymium oxide, if necessary, with admixture of a small amount of the dopant oxide such as calcium oxide, magnesium oxide, zirconium oxide and the like as grown on the bottom end of a single crystal seed.
The rare earth-based oxide garnet single crystal of the invention to be grown on the surface of the above described garnet single crystal as the substrate usually in the form of a flat plate or disc has a chemical composition represented by the formula (I) given before in which each symbol has the meaning as defined there. It is important that the value of the subscript a in the formula is at least 1.1 because, when the value of a is too small, the saturation magnetization of the oxide garnet single crystal cannot be lower than 700 G which is a desirable upper limit of the saturation magnetization in order that an magneto-optical device such as optical isolators and the like can be constructed with a sufficiently compact magnet.
Thus, an oxide melt is formed from the respective oxides including gadolinium oxide Gd 2 O 3 , holmium oxide Ho 2 O 3 , bismuth oxide Bi 2 O 3 , iron oxide Fe 2 O 3 and, if the subscript d is not zero, europium oxide Eu 2 O 3 together with flux materials including lead oxide PbO and boron oxide B 2 O 3 by heating the mixture at a temperature of 1100° to 1200 ° C. with the substrate plate immersed therein followed by keeping the melt in a supercooled state at a temperature of 750° to 950° C. so that epitaxial growth of the oxide garnet single crystal proceeds on the surface of the substrate plate to form a layer of the single crystal.
In the above described method of liquid epitaxial growth of the inventive rare earth-based oxide garnet single crystal on the substrate surface, it is important that the epitaxially grown single crystal layer has a relatively large thickness still without any cracks or other defects that the difference between the lattice constant of the epitaxially grown oxide garnet single crystal and that of the garnet single crystal as the substrate, which is 1.2508 nm in the NGG and 1.2496 nm in the NOG, is as small as possible or, desirably, not larger by ±0.0003 nm. This requirement can be satisfied by appropriately selecting the values of the subscripts a, b, c and d in the composition formula (I). With the prerequisite that the value of the subscript a must be 1.1 or larger as is mentioned above, for example, the value of b should not exceed 0.9 since otherwise the lattice constant of the epitaxially grown single crystal is too small. The balance between the values of a and b is also important because, if the content of bismuth in the single crystal is too low, the single crystal would suffer from a decrease in the Faraday rotation coefficient. This problem is solved by selecting the value of the subscript a not exceeding 2.1 and the value of b not smaller than 0.1. These limitations in the values of a and the subscript b also satisfactory in order not to unduly increase the lattice constant of the single crystal.
When the above mentioned requirements are satisfied so as to almost completely eliminate the mismatching in the lattice constant between the substrate single crystal and the epitaxially grown single crystal, the epitaxially grown oxide garnet single crystal of the invention is free from any defects such as cracks and pits on the surface. The principal constituents including gadolinium, holmium and europium, each being a rare earth element, naturally have good compatibility with other rare earth ions not to cause any problems relative to the uniformity of the oxide garnet single crystal. The combination of gadolinium and holmium is particularly advantageous in order to effect an improvement in respect of the light absorption at a wavelength of 1.55 μm. The saturation magnetization can be small enough when appropriate selection is made for the content of gadolinium. In addition, introduction of europium has an effect to further improve the light absorption. Having these characteristics, the rare earth-based oxide garnet single crystal of the invention can be used advantageously as a material of various kinds of magneto-optical devices such as optical isolators and the like of high performance with compact dimensions.
In the following, the rare earth-based oxide garnet single crystal of the invention is described in more detail by way of examples and comparative examples.
EXAMPLE 1
The substrate plate used for the epitaxial growth of the inventive oxide garnet single crystal was a single crystal wafer of NOG having a thickness of 0.500 mm and a diameter of 25 mm with a lattice constant of 1.2496 nm. Into a platinum crucible were introduced 8.610 g of gadolinium oxide, 5.983 g of holmium oxide, 932.04 g of bismuth oxide, 120.55 g of iron oxide, 892.9 g of lead oxide and 39.90 g of boron oxide and they were mixed together and heated at 1100° C. to form a melt in which the substrate wafer was immersed. The temperature of the melt was gradually decreased and kept in the range from 784.5° to 789.5° C. for about 53 hours so as to effect epitaxial growth of the oxide garnet single crystal layer on both of the substrate surfaces.
The thus epitaxially formed layer of the oxide garnet single crystal having a thickness of 0.591 mm was analyzed for the chemical composition by the ICP (induction-coupled plasma) emission spectrophotometry to find that the chemical composition thereof could be expressed by the formula
Gd.sub.1.26 Ho.sub.0.76 Bi.sub.0.98 Fe.sub.5 O.sub.12.
The epitaxially grown single crystal layers of the oxide garnet on the substrate surfaces were freed from the substrate wafer by mechanical working and polished on the surface followed by cutting into pieces of the epitaxially grown oxide garnet single crystal each having dimensions of 2.9 mm by 2.9 mm by 0.512 mm which were subjected to the measurement of the magneto-optical properties at a wavelength of 1.55 μm to find quite satisfactory values of the parameters including -44.8 degrees of the Faraday rotation angle, 0.056 degree/°C. of the temperature dependency coefficient thereof, -875 degrees/cm of the Faraday rotation coefficient, 0.05 dB of the loss by light absorption and 660 G of the saturation magnetization.
EXAMPLE 2
The same NOG wafer as in Example 1 was used as the substrate plate and the epitaxial growth of an oxide garnet single crystal layer thereon was performed at a temperature in the range from 783.5° to 788.5° C. for 47 hours in a melt of an oxide mixture consisting of 8.318 g of gadolinium oxide, 5.780 g of holmium oxide, 931.82 g of bismuth oxide, 116.47 g of iron oxide, 5.011 g of gallium oxide, 892.7 g of lead oxide and 39.89 g of boron oxide melted by heating at 1100° C. in a platinum crucible.
The thus formed layer of the oxide garnet single crystal having a thickness of 0.636 mm was analyzed for the chemical composition by the ICP emission spectrophotometry to find that the chemical composition thereof could be expressed by the formula
Gd.sub.1.18 Ho.sub.0.71 Bi.sub.1.11 Fe.sub.4.73 Ga.sub.0.27 O.sub.12.
The epitaxially grown single crystal layers of the oxide garnet were freed from the substrate wafer by mechanical working and polished on the surface followed by cutting into pieces of the epitaxially grown oxide garnet single crystal each having dimensions of 2.9 mm by 2.9 mm by 0.559 mm which were subjected to the measurement of the magneto-optical properties at a wavelength of 1.55 μm to find quite satisfactory values of the parameters including -44.8 degrees of the Faraday rotation angle, 0.059 degree/°C. of the temperature dependency coefficient thereof, -801 degrees/cm of the Faraday rotation coefficient, 0.05 dB of the loss by light absorption and 430 G of the saturation magnetization.
Comparative Example 1
The same NOG wafer as in Example 1 was used as the substrate plate and the epitaxial growth of an oxide garnet single crystal layer thereon was performed at a temperature in the range from 749.5° to 752.5° C. for 63 hours in a melt of an oxide mixture consisting of 1.489 g of europium oxide, 13.929 g of terbium oxide, 977.38 g of bismuth oxide, 123.86 g of iron oxide, 5.273 g of gallium oxide, 936.36 g of lead oxide and 41.72 g of boron oxide melted by heating at 1100° C. in a platinum crucible..
The thus formed layers of the oxide garnet single crystal having a thickness of 0.695 mm were analyzed for the chemical composition by the ICP emission spectrophotometry to find that the chemical composition thereof could be expressed by the formula
Eu.sub.0.21 Tb.sub.1.97 Bi.sub.0.82 Fe.sub.4.71 Ga.sub.0.29 O.sub.12.
The wafer-borne epitaxially grown single crystal layers of the oxide garnet were freed from the substrate wafer by mechanical working and polished on the surface followed by cutting into pieces of the epitaxially grown oxide garnet single crystal each having dimensions of 2.9 mm by 2.9 mm by 0.559 mm which were subjected to the measurement of the magneto-optical properties at a wavelength of 1.55 μm to find quite satisfactory values of the parameters including -44.7 degrees of the Faraday rotation angle, 0.051 degree/°C. of the temperature dependency coefficient thereof, -736 degrees/cm of the Faraday rotation coefficient and 350 G of the saturation magnetization but the loss by light absorption was as large as 0.12 dB.
EXAMPLE 3
The substrate plate used for the epitaxial growth of the inventive oxide garnet single crystal was a single crystal wafer of NOG having a thickness of 0.500 mm and a diameter of 25 mm with a lattice constant of 1.2496 nm. Into a platinum crucible were introduced 7.732 g of gadolinium oxide, 5.373 g of holmium oxide, 1.421 g of europium oxide, 932.07 g of bismuth oxide, 120.55 g of iron oxide, 892.94 g of lead oxide and 39.90 g of boron oxide and they were mixed together and heated at 1100° C. to form a melt in which the substrate wafer was immersed. The temperature of the melt was gradually decreased and kept in the range from 786.0° to 791.0° C. for about 66 hours so as to effect epitaxial growth of the oxide garnet single crystal layer on both of the substrate surfaces.
The thus epitaxially formed layer of the oxide garnet single crystal having a thickness of 0.725 mm was analyzed for the chemical composition by the ICP (induction-coupled plasma) emission spectrophotometry to find that the chemical composition thereof could be expressed by the formula
Gd.sub.1.21 Ho.sub.0.82 Eu.sub.0.20 Bi.sub.0.77 Fe.sub.5 O.sub.12.
The epitaxially grown single crystal layers of the oxide garnet on the substrate surfaces were freed from the substrate wafer by mechanical working and polished on the surface followed by cutting into pieces of the epitaxially grown oxide garnet single crystal each having dimensions of 2.9 mm by 2.9 mm by 0.669 mm which were subjected to the measurement of the magneto-optical properties at a wavelength of 1.55 μm to find quite satisfactory values of the parameters including -45.0 degrees of the Faraday rotation angle, 0.056 degree/°C. of the temperature dependency coefficient thereof, -673 degrees/cm of the Faraday rotation coefficient, 0.02 dB of the loss by light absorption and 670 G of the saturation magnetization.
Comparative Example 2
The same NOG wafer as in Example I was used as the substrate plate and the epitaxial growth of an oxide garnet single crystal layer thereon was performed at a temperature in the range from 757.5° to 762.5° C. for 38 hours in a melt of an oxide mixture consisting of 5.740 g of gadolinium oxide, 8.974 g of holmium oxide, 931.98 g of bismuth oxide, 120.54 g of iron oxide, 892.86 g of lead oxide and 39.90 g of boron oxide melted by heating at 1100° C. in a platinum crucible ..
The thus formed layers of the oxide garnet single crystal having a thickness of 0.696 mm were analyzed for the chemical composition by the ICP emission spectrophotometry to find that the chemical composition thereof could be expressed by the formula
Gd.sub.0.95 Ho.sub.1.03 Bi.sub.1.02 Fe.sub.5 O.sub.12.
The wafer-borne epitaxially grown single crystal layers of the oxide garnet were freed from the substrate wafer by mechanical working and polished on the surface followed by cutting into pieces of the epitaxially grown oxide garnet single crystal each having dimensions of 2.9 mm by 2.9 mm by 0.498 mm which were subjected to the measurement of the magneto-optical properties at a wavelength of 1.55 μm to find quite satisfactory values of the parameters including -44.8 degrees of the Faraday rotation angle, 0.067 degree/°C. of the temperature dependency coefficient thereof, -904 degrees/cm of the Faraday rotation coefficient and as large as 820 G of the saturation magnetization not to ensure use of a compact magnet in a magneto-optical device such as optical isolators although the loss by light absorption was as large as 0.06 dB.
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A novel rare earth-based oxide garnet single crystal suitable as a material of the elements in a magneto-optical device to exhibit a greatly decreased light absorption loss is proposed, which is prepared by the liquid epitaxial growth method on a oxide garnet single crystal wafer and having a chemical composition represented by the general formula
Gd.sub.a Ho.sub.b Eu.sub.d Bi.sub.3-a-b-d Fe.sub.5-c M.sub.c O.sub.12,
in which M is an element or a combination of elements selected from the group consisting of aluminum, scandium, gallium and indium, the subscript a is a positive number in the range from 1.1 to 2.1, the subscript b is a positive number in the range from 0.1 to 0.9, the subscript c is 0 or a positive number not exceeding 0.5 and the subscript d is zero or a positive number not exceeding 0.6 or, in particular, in the range from 0.03 to 0.6 with the proviso that 3-a-b-d is in the range from 0.7 to 1.2.
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BACKGROUND
[0001] 1. Technical Field
[0002] The present invention relates to a terminal apparatus and a communication method thereof.
[0003] 2. Description of the Related Art
[0004] In the uplink of the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE), single carrier transmission is performed to maintain a low cubic metric (CM). More specifically, in the presence of data signals, the data signals and control information are time multiplexed and transmitted in a physical uplink shared channel (PUSCH). The control information includes response signals (positive/negative acknowledgments (ACK/NACK), hereinafter called “ACK/NACK signals”) and channel quality indicators (hereinafter called the “CQIs”). Data signals are divided into code blocks (CB), and a cyclic redundancy check (CRC) code is added to each code block for error correction.
[0005] ACK/NACK signals and CQIs have different allocation methods. (See Non-Patent Literatures 1 and 2, for example). More specifically, ACK/NACK signals are allocated in parts of a data signal resource by puncturing parts of the data signals (4 symbols) mapped to the resource adjacent to Reference Signals (RSs) (i.e., overwriting the data signals with the ACK/NACK signals). In contrasts, CQIs are allocated over entire sub-frames (2 slots). Since the data signals are allocated in resources other than the CQI allocated resource, no CQIs are punctured (see FIG. 1 .) The reasons for the difference in allocation are as follows: the allocation or non-allocation of an ACK/NACK signal depends on the presence or absence of data signals in downlink. In other words, it is more difficult to predict the occurrence of ACK/NACK signals than it is to predict that of CQIs; hence, puncturing capable of allocating the resource of a suddenly occurring ACK/NACK signal is used during mapping of ACK/NACK signals. Meanwhile, the timing of CQI transmission (i.e., sub-frames) is predetermined based on notification information, which allows the determination of allocation of data signal and CQI resources. Since ACK/NACK signals are important information, they are assigned to symbols in the vicinity of pilot signals, which have high estimation accuracy of transmission paths, thereby reducing ACK/NACK signal errors.
[0006] A modulation and coding rate scheme (MCS) for data signals in uplink is determined by a base station apparatus (hereinafter called the “base station” or “eNB”) based on the channel quality of the uplink. An MCS for control information in the uplink is determined by adding an offset to the MCS for data signals (see Non-Patent Literature 1, for example). More specifically, since control information is more important than data signals, the MCS for control information is set to a lower transmission rate than the MCS for data signals. This guarantees high-quality transmission of control information.
[0007] For example, in the 3GPP LTE uplink, if control information is transmitted in a PUSCH, the amount of resource assigned to the control information is determined based on a coding rate indicated in the MCS for data signals. More specifically, as shown in equation 1 below, the amount of the resource Q assigned to the control information is obtained by multiplying the inverse of the coding rate of data signal by an offset.
[0000]
Q
=
⌈
(
O
+
P
)
·
M
sc
PUSCH
-
initial
·
N
symb
PUSCH
-
initial
·
β
offset
PUSCH
∑
r
=
0
C
-
1
K
r
⌉
(
Equation
1
)
[0008] With reference to equation 1, O indicates the number of bits in control information (i.e., ACK/NACK signal or CQI) and P indicates the number of bits for error correction added to the control information (for example, the number of bits in CRC and in some cases, P=0). The total of O and P (O+P) indicates the number of bits in uplink control information (UCI). M SC PUSCH-initial , N Symb PUSCH-initial , C and K r indicate the transmission bandwidth for PUSCH, the number of symbols transmitted in the PUSCH per unit transmission bandwidth, the number of code blocks into which data signals are divided, and the number of bits in each code block, respectively. UCI (i.e., control information) includes ACK/NACK, CQI, a rank indicator (RI), which indicates rank information, and a precoding matrix indicator (PMI), which provides precoding information.
[0009] With reference to equation 1, (M SC PUSCH-initial ·N Symb PUSCH-initial ) indicates the amount of transmission data signal resources, ΣK r indicates the number of bits in a single data signal (i.e., the total number of bits in code blocks into which the data signal is divided). Accordingly, ΣK r /(M SC PUSCH-initial ·N Symb PUSCH-initial ) represents a value that depends the coding rate of the data signal (hereinafter, called “coding rate”). The (M SC PUSCH-initial ·N Symb PUSCH-initial )/ΣK r shown in equation 1 indicates the inverse of the coding rate of data signal (i.e., the number of resource elements (RE: resource composed of one symbol or one sub-carrier) used to transmit one bit) β offset PUSCH indicates the amount of offset by which the above-mentioned inverse of the coding rate of data signal is multiplied, and is reported from a base station to each terminal apparatus (hereinafter, called the “terminal” or UE) via upper layers. More specifically, a table indicating candidates of the amounts of offset β offset PUSCH is defined for each part of control information (i.e., ACK/NACK signal and CQI). For example, a base station selects one amount of offset β offset PUSCH from the table (for example, see FIG. 2 ) containing candidates for the amount of offset β offset PUSCH defined for ACK/NACK signal and then notifies a terminal of a notification index corresponding to the selected amount of offset. As is evident from the term “PUSCH-initial,” (M SC PUSCH-initial ·N Symb PUSCH-initial ) represents the amount of transmission resource for the initial transmission of a data signal.
[0010] The standardization of 3GPP LTE-Advanced, which provides higher-speed transmission than 3GPP LTE, has started. The 3GPP LTE-Advanced system (hereinafter, may be called “LTE-A system”) follows the 3GPP LTE system (hereinafter, called “LTE system”). In 3GPP LTE-Advanced, base stations and terminals that can communicate in a wideband frequency range of 40 MHz or higher will be introduced to achieve downlink transmission rates of up to 1 Gbps.
[0011] In an LTE-Advanced uplink, the use of single user multiple input multiple output (SU-MIMO) transmission in which a single terminal transmits data signals in a plurality of layers has been studied. In the SU-MIMO communications, data signals are generated in a plurality of code words (CWs), each of which is transmitted in different layers. For example, CW#0 is transmitted in layers #0 and #1, and CW#1 is transmitted in layers #2 and #3. In each CW, a data signal is divided into a plurality of code blocks and CRC is added to each code block for error correction. For example, a data signal in CW#0 is divided into five code blocks and a data signal in CW#1 into eight code blocks. The “code word” can be regarded as a unit of data signals to be retransmitted. The “layer” is a synonym of a stream.
[0012] Unlike the above-mentioned LTE-A system, the LTE systems disclosed in the above-mentioned Non-Patent Literatures 1 and 2 assume the use of the non-MIMO transmission in uplink. In the non-MIMO transmission, a single layer is used at each terminal
[0013] In the SU-MIMO transmission, control information is transmitted in a plurality of layers in some cases, and it is transmitted in one of the plurality of layers in other cases. For example, in an LTE-Advanced uplink, allocation of an ACK/NACK signal in a plurality of CWs and of a CQI in a single CW has been studied. More specifically, since an ACK/NACK signal is the most important information in all parts of control information, the same ACK/NACK signal is allocated in all the CWs (i.e., the same information is assigned to all layers (rank-1 transmission)), thereby reducing inter-layer interference. The same ACK/NACK signals transmitted in a plurality of CWs (i.e., space-division multiplexed) are combined into a single part of information on a transmission path, thereby eliminating the need for the receiving side (base station) to separate the ACK/NACK signals transmitted in a plurality of CWs. Accordingly, inter-layer interference that may occur on the receiving side during the separation does not occur. Thus, high receiving quality can be achieved. Note that the description below assumes that the control information is an ACK/NACK signal and allocated in two CWs (CW#0 and CW#1).
CITATION LIST
Non-Patent Literatures
NPL1
[0014] TS36.212 v8.7.0, “3GPP TSG RAN; Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding”
NPL2
[0015] TS36.213 v8.8.0, “3GPP TSG RAN; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Layer Procedure”
BRIEF SUMMARY
Technical Problem
[0016] In the SU-MIMO communications, when transmitting control information in a PUSCH, the amount of the resource required to allocate control information (ACK/NACK signals) is determined based on the coding rate of one of the two CWs, just as in the LTE system (for example, Non-Patent Literature 1). For example, as shown in equation 2 below, the coding rate r CW#0 of CW#0 of the two CWs (i.e., CW#0 and CW#1) is used to determine the amount of the resource Q CW#0 required to assign control information in each layer.
[0000]
Q
CW
#0
=
⌈
(
O
+
P
)
×
1
r
CW
#0
×
β
offset
PUSCH
/
L
⌉
(
Equation
2
)
[0017] In equation 2, L indicates the total number of layers (the total number of layers to which CW#0 and CW#1 are assigned). In equation 2, as in equation 1, the amount of the resource required to allocate control information in each layer is determined by multiplying the inverse (1/r CW#0 ) of the coding rate r CW#0 by an offset amount β offset PUSCH and then dividing the result by the total number of layers L. A terminal uses the amount of the resource Q CW#0 determined in accordance with equation 2 to transmit CW#0 and CW#1 assigned to the layers (i.e., L layers).
[0018] In this case, however, when CW#0 and CW#1 are combined in the base station, there is a concern that the reception quality of control information after the combination may be poor and fail to meet a requirement.
[0019] CW#0, for example, is transmitted using the amount of the resource Q CW#0 which is determined based on the coding rate r CW#0 of CW#0, that is, the amount of resource appropriate for CW#0. Accordingly, control information allocated in CW#0 is likely to meet required reception quality. In contrast, CW#1 is transmitted using the amount of the resource Q CW#0 which is determined based on the coding rate r CW#0 of CW#0 (that is, the other CW). Thus, control information allocated in CW#1 may degrade in the reception quality if the layer to which CW#1 is allocated has a poor transmission path environment.
[0020] As shown in FIG. 3 , for example, CW#0 is allocated in layer #0 and layer #1 and CW#1 is allocated in layer #2 and layer #3. A description is given of a case where the coding rate of CW#0 is higher than the coding rate of CW#1. To put it differently, the amount of resource required for the control information allocated in CW#0 is smaller than that required for the control information allocated in CW#1.
[0021] In layers #0 and #1, control information allocated in CW#0 can meet the reception quality required by each CW (i.e., reception quality required for control information for the LTE system/the number of CWs). In contrast, in layers #2 and #3, the control information allocated in CW#1 has an amount of resource determined based on CW#0; thus, the amount of resource to meet the required reception quality runs short, thus failing to meet the reception quality required for each CW. Thus, a combination of the control information allocated in CW#0 and CW#1 may result in a lower reception quality than that required for all the CWs (i.e., reception quality required for control information in the LTE system).
[0022] Accordingly, it is an object of the present invention to provide a terminal capable of preventing the degradation of reception quality of control information even in a case of adopting the SU-MIMO transmission method, and also to provide a communication method thereof.
Solution to Problem
[0023] A first aspect of the present invention provides a terminal apparatus that transmits two code words to which control information is allocated, in a plurality of different layers, the apparatus including: a determination section that determines the amount of resource of the control information in each of the plurality of layers; and a transmission signal generating section that generates a transmission signal through modulation of the control information using the amount of the resource and allocation of the modulated control information to the two code words, in which the determination section determines the amount of the resource based on a lower coding rate of the coding rates of the two code words, or the average of the inverses of the coding rates of the two code words.
[0024] A second aspect of the present invention provides a communication method including: determining an amount of resource of control information in each of a plurality of different layers in which two code words are transmitted, the control information being allocated in the two code words; modulating the control information using the amount of the resource; and allocating the modulated control information in the two code words to generate a transmission signal, in which the amount of the resource is determined based on a lower coding rate of the coding rates of the two code words, or the average of the inverses of the coding rates of the two code words.
Advantageous Effects of Invention
[0025] The present invention can prevent the degradation of reception quality of control information even in a case of adopting the SU-MIMO transmission method.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0026] FIG. 1 shows a conventional allocation of ACKs/NACKs and CQIs;
[0027] FIG. 2 is a diagram provided for describing a table containing candidates for an offset amount in the conventional case;
[0028] FIG. 3 is a diagram provided for describing a technical problem;
[0029] FIG. 4 is a block diagram showing the configuration of a base station according to Embodiment 1 of the present invention;
[0030] FIG. 5 is a block diagram showing the configuration of a terminal according to Embodiment 1 of the present invention;
[0031] FIG. 6 shows exemplary correction factors according to Embodiment 1 of the present invention;
[0032] FIG. 7 shows exemplary correction factors according to Embodiment 2 of the present invention;
[0033] FIG. 8 shows exemplary correction factors according to Embodiment 2 of the present invention;
[0034] FIG. 9 shows a technical problem in the case where the number of layers differs between initial transmission and re-transmission according to Embodiment 3 of the present invention; and
[0035] FIG. 10 shows a process for determining the amount of resource of control information according to Embodiment 3 of the present invention.
DETAILED DESCRIPTION
[0036] Embodiments of the present invention will be hereinafter described in detail with reference to the accompanying drawings. In the embodiments, the same components are given the same reference numerals without redundant descriptions.
Embodiment 1
(Overview of Communication System)
[0037] In the following description, a communications system including base station 100 and terminal 200 as described hereinafter is an LTE-A system, for example. Base station 100 is an LTE-A base station, and terminal 200 is an LTE-A terminal, for example. The communication system is assumed to be a frequency division duplex (FDD) system. Terminal 200 (LTE-A terminal) can be switched between non-MIMO and SU-MIMO transmission modes.
(Configuration of Base Station)
[0038] FIG. 11 is a block diagram showing the configuration of base station 100 according to this embodiment.
[0039] In base station 100 as shown in FIG. 4 , setting section 101 sets control parameters related to resource allocation for control information (including at least ACK/NACK signals or CQIs) transmitted in an uplink data channel (PUSCH) used to communicate with a terminal for which the control parameters are set based on the transmitting and receiving capability of the terminal (i.e., UE capability) or the state of the transmission path. The control parameters include, for example, an amount of offset (for example, an amount of offset β offset PUSCH as shown in equation 2) used in allocation of resource of control information transmitted by the terminal for which the control parameters are set. Setting section 101 outputs setting information including the control parameters to coding and modulating section 102 and ACK/NACK and CQI receiving section 111 .
[0040] For terminals performing the non-MIMO transmission, setting section 101 generates MCS information for a single CW (or transport block) and allocation control information including resource (or resource block (RB)) allocation information, while for terminals performing SU-MIMO transmission, setting section 101 generates allocation control information including MCS information for the two CWs (or transport blocks), or the like.
[0041] The allocation control information generated by setting section 101 includes uplink allocation control information indicating uplink resource (for example, physical uplink shared channel (PUSCH)) to which uplink data of a terminal is assigned, and downlink allocation control information indicating downlink resource (for example, physical downlink shared channel (PDSCH)) to which downlink data addressed to a terminal is assigned. In addition, the downlink allocation control information includes information indicating the number of bits of ACK/NACK signals for the downlink data (i.e., ACK/NACK information). Setting section 101 outputs the uplink allocation control information to coding and modulating section 102 , reception processing sections 109 in reception sections 107 - 1 to 107 -N, and ACK/NACK and CQI receiving section 111 and outputs the downlink allocation control information to transmission signal generating section 104 and ACK/NACK and CQI receiving section 111 .
[0042] Coding and modulating section 102 codes and modulates the set information and uplink allocation control information received from setting section 101 , and then outputs the modulated signals to transmission signal generating section 104 .
[0043] Coding and modulating section 103 codes and modulates transmission data to be received and then outputs the modulated data signals (for example, PDSCH signals) to transmission signal generating section 104 .
[0044] Transmission signal generating section 104 allocates the signals received from coding and modulating section 102 and the data signals received from coding and modulating section 103 to a frequency resource to generate frequency domain signals based on the downlink allocation control information received from setting section 101 . Transmission signal generating section 104 then converts the frequency domain signals into time-waveform signals using inverse fast Fourier transform (IFFT) processing, and adds a cyclic prefix (CP) to the time waveform signals, thereby obtaining orthogonal frequency division multiplexing (OFDM) signals.
[0045] Transmitting section 105 performs radio transmission processing (upconversion and digital-analogue (D/A) conversion and/or the like) on the OFDM signals received from transmission signal generating section 104 , and then transmits the signals through antenna 106 - 1 .
[0046] Reception sections 107 - 1 to 107 -N are provided to antennas 106 - 1 to 106 -N, respectively. Reception sections 107 include respective radio processing sections 108 and reception processing sections 109 .
[0047] More specifically, radio processing sections 108 in respective reception sections 107 - 1 to 107 -N receive radio signals through respective antennas 106 , perform radio processing (downconversion and analog-digital (A/D) conversion and/or the like) on the received radio signals and then output the resulting reception signals to respective reception processing sections 109 .
[0048] Reception processing sections 109 remove CP from the reception signals and perform fast Fourier transform (FFT) on the signals to convert the signals into frequency domain signals. Reception processing sections 109 extract uplink signals for each terminal (including data signals and control signals (i.e., ACK/NACK signal and CQI)) from the frequency domain signals based on the uplink allocation control information received from setting section 101 . If the reception signals are space-division multiplexed (that is, a plurality of CWs are used (i.e., on the SU-MIMO transmission)), reception processing sections 109 separate and combine the CWs. Reception processing sections 109 then perform inverse discrete Fourier transform (IDFT) processing on the extracted (or extracted and separated) signals to convert the signals into time domain signals. Reception processing sections 109 output the time domain signals to data reception section 110 and ACK/NACK and CQI receiving section 111 .
[0049] Data reception section 110 decodes the time domain signals received from reception processing sections 109 and then outputs the decoded uplink data as reception data.
[0050] ACK/NACK and CQI receiving section 111 calculates the amount of uplink resource to which ACK/NACK signals are assigned, based on the setting information (i.e., control parameters), the MCS information for uplink data signals (i.e., MCS information for each CW in the case of the SU-MIMO transmission), and the downlink allocation control information (for example, ACK/NACK information showing the number of bits of ACK/NACK signals for downlink data) received from setting section 101. For CQIs, ACK/NACK and CQI receiving section 111 further calculates an amount of uplink resource (e.g., PUSCH) to which the CQI is assigned, using information concerning the preset number of bits of a CQI. Based on the calculated amount of resource, ACK/NACK and CQI receiving section 111 then extracts ACK/NACKs or CQIs from each terminal for downlink data (PDSCH signals) from the channel (for example, PUSCH) to which uplink data signals have been assigned.
[0051] If the traffic state in cells covered by base station 100 remains unchanged or if the measurement of an average reception quality is needed, control parameters (for example, the amount of offset β offset PUSCH ) to be notified by base station 100 to terminal 200 should preferably be transmitted in an upper layer at a long notification interval (RRC signaling) from a perspective of signaling. Transmitting all or part of these control parameters as broadcast information leads to a reduction in an amount of resource required for the notification. On the contrary, if control parameters need to be dynamically changed in response to the traffic state in cells covered by base station 100, all or part of these control parameters should preferably be notified in a PDCCH at a short notification interval.
(Terminal Configuration)
[0052] FIG. 12 is a block diagram showing the configuration of terminal 200 in accordance with Embodiment 1 of the present invention. Terminal 200 is an LTE-A terminal which receives data signals (downlink data) and transmits an ACK/NACK signal corresponding to the data signals through a physical uplink control channel (PUCCH) or PUSCH to base station 100 . Terminal 200 transmits a CQI to base station 100 in accordance with instruction information notified through a physical downlink control channel (PDCCH).
[0053] In terminal 200 shown in FIG. 5 , reception section 202 performs radio processing (down-conversion and analog-digital (A/D) conversion and/or the like) on radio signals received through antenna 201 - 1 (i.e., OFDM signals herein) and outputs the resulting reception signals to reception processing section 203 . The reception signals include data signals (for example, PDSCH signals), allocation control information and upper layer control information including setting information.
[0054] Reception processing section 203 removes CP from the reception signals and performs fast Fourier transform (FFT) on the remaining signals to convert the signals into frequency domain signals. Reception processing section 203 then separates the frequency domain signals into upper layer control signals (for example, RRC signaling) including setting information, allocation control information, and data signals (i.e., PDSCH signals), and then demodulates and decodes the separated signals. Reception processing section 203 also checks the data signals for an error, and if the received data contains an error, a NACK signal is generated, and if not, it generates an ACK signal as the ACK/NACK signal. Reception processing section 203 outputs ACK/NACK signals and ACK/NACK information and MCS information in the allocation control information to resource amount determining section 204 and transmission signal generating section 205 , and outputs setting information (for example, control parameters (an amount of offset)) to resource amount determining section 204 , and outputs the uplink allocation control information in the allocation control information (for example, uplink resource allocation results) to transmission processing sections 207 in respective transmitting sections 206 - 1 to 206 -M.
[0055] Resource amount determining section 204 determines the amount of resource required to allocate ACK/NACK signals, based on the ACK/NACK information (the number of bits of ACK/NACK signals), MCS information and control parameters (an amount of offset or the like) concerning resource allocation of control information (ACK/NACK signals) received from reception processing section 203 . For CQIs, resource amount determining section 204 determines the amount of resource required to allocate CQIs, based on the MCS information and control parameters (an amount of offset or the like) concerning resource allocation of control information (CQIs) received from reception processing section 203 , and the preset number of bits of a CQI. In the case of the SU-MIMO transmission, where the two CWs (CW#0 and CW#1) are transmitted in a plurality of layers, resource amount determining section 204 determines the amount of resource for each of the plurality of layers, the amount of the resource being allocated to control information (ACK/NACK signals) allocated in the two CWs (CW#0 and CW#1). More specifically, resource amount determining section 204 determines the amount of the resource based on either the lower coding rate of the coding rates of the two CWs or the average of the inverses of the coding rates of the two CWs. Details on methods for determining the amount of the resource required to allocate control information (ACK/NACKs or CQIs) in resource amount determining section 204 is given hereinafter. Resource amount determining section 204 outputs the determined amount of resource to transmission signal generating section 205 .
[0056] Transmission signal generating section 205 generates a transmission signal by allocating an ACK/NACK signal (error detection result of downlink data), data signals (uplink data) and CQIs (downlink quality information) in CWs allocated to one or more layers based on the ACK/NACK information (the number of bits of an ACK/NACK signal) and MCS information received from reception processing section 203 .
[0057] More specifically, transmission signal generating section 205 first modulates the ACK/NACK signal based on the amount of the resource (i.e., the amount of resource of the ACK/NACK signal) received from resource amount determining section 204 . Transmission signal generating section 205 also modulates the CQI based on the amount of the resource (i.e., the amount of resource of the CQIs) received from resource amount determining section 204 . Transmission signal generating section 205 modulates transmission data using the amount of the resource specified by using the amount of the resource (i.e., CQI resource amount) received from resource amount determining section 204 (the amount of the resource is specified by subtracting the amount of CQI resource from the amount of the resource for each slot).
[0058] In the case of non-MIMO transmission, transmission signal generating section 205 generates a transmission signal by allocating the ACK/NACK signal, data signals and CQI that have been modulated using the above-mentioned amount of resource in a single CW. Meanwhile, in the case of SU-MIMO transmission, transmission signal generating section 205 generates a transmission signal by allocating the ACK/NACK signal and data signals that have been modulated using the above-mentioned amount of resource in the two CWs and by allocating the CQI in one of the two CWs. Furthermore, in the case of non-MIMO transmission, transmission signal generating section 205 assigns a single CW to a single layer, and in the case of SU-MIMO transmission, transmission signal generating section 205 assigns the two CWs to a plurality of layers. For example, in the case of the SU-MIMO transmission, transmission signal generating section 205 assigns CW#0 to layer #0 and layer #1 and assigns CW#1 to layer #2 and layer #3.
[0059] In the presence of data signals and CQIs to be transmitted, transmission signal generating section 205 assigns the data signals and CQIs to an uplink data channel (PUSCH) by time multiplexing or frequency division multiplexing using a rate matching in one of the plurality of CWs as shown in FIG. 1 . In the presence of data signals and ACK/NACK signals to be transmitted, transmission signal generating section 205 overwrites part of the data signals with ACK/NACK signals in all of the plurality of layers (i.e., puncturing). To put it differently, ACK/NACK signals are transmitted in all the layers. In the absence of data signals to be transmitted, transmission signal generating section 205 assigns CQIs and ACK/NACK signals to an uplink control channel (for example, PUCCH). Transmission signal generating section 205 then outputs the transmission signals thus generated (including ACK/NACK signals, data signals or CQIs) to transmitting sections 206 - 1 to 206 -M.
[0060] Transmitting sections 206 - 1 to 206 -M correspond to antennas 201 - 1 to 201 -M, respectively. Transmitting sections 206 include respective transmission processing sections 207 and radio processing sections 208 .
[0061] More specifically, transmission processing sections 207 in respective transmitting sections 206 - 1 to 206 -M perform discrete Fourier transform (DFT) to the transmission signals received from transmission signal generating section 205 (i.e., signals corresponding to respective layers) to convert the data signals, ACK/NACK signals and CQIs into frequency domain signals. Transmission processing sections 207 then maps the plurality of frequency components obtained by the DFT processing (including ACK/NACK signals and CQIs transmitted on the PUSCH) to the uplink data channels (PUSCH) based on the uplink resource allocation information received from reception processing section 203 . Transmission processing sections 207 convert the plurality of frequency components mapped to the PUSCH into time domain waveforms and add CP thereto.
[0062] Radio processing sections 208 perform radio processing (upconversion and digital-analog (D/A) conversion and/or the like) on the signals to which CP has been added, and then transmit the signals through respective antennas 201 - 1 to 201 -M.
(Operations of Base Station 100 and Terminal 200 )
[0063] The operations of base station 100 and terminal 200 having the above-mentioned configurations will be described below. In particular, the method used by resource amount determining section 204 of terminal 200 to determine the amount of the resource required to allocate control information (ACK/NACKs or CQIs) will be described in details. In the following description, the method for determining the amount of the resource in the SU-MIMO transmission, where a plurality of CWs to which control information is allocated are transmitted in a plurality of layers, will be described.
[0064] In the following description, terminal 200 (transmission signal generating section 205 ) allocates ACK/NACK signals, which are control information, in the two CWs (i.e., CW#0 and CW#1).
[0065] Determination Methods 1 to 5 for determining the amount of the resource of control information are described below.
<Determination Method 1>
[0066] In Determination Method 1, resource amount determining section 204 determines the amount of the resource required to allocate control information in each layer based on the lower coding rate of the coding rates of the two CWs to which control information is allocated. More specifically, resource amount determining section 204 determines the amount of the resource required to allocate control information in each layer Q CW#0+CW#1 based on the lower coding rate of the coding rates of CW#0 and CW#1 (coding rate r lowMCS ) in accordance with equation 3.
[0000]
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
×
1
r
lowMCS
×
β
offset
PUSCH
/
L
⌉
(
Equation
3
)
[0067] With reference to equation 3, O indicates the number of bits in control information and P indicates the number of bits for error correction added to control information (for example, the number of bits in CRC and in some cases, P=0). L indicates the total number of layers (the total number of layers containing CWs).
[0068] Resource amount determining section 204 , as shown in equation 3 and as in equation 1, determines the amount of the resource of control information in each layer by multiplying the inverse (1/r lowMCS ) of the coding rate r lowMCS by the amount of offset β offset PUSCH , and then dividing the result by the total number of layers L.
[0069] In this manner, the reception quality required by each CW can be ensured in all the layers. More specifically, in the layer containing CW#0 or CW#1 having the lower coding rate (i.e., CW with the coding rate r lowMCS ), the amount of resource Q CW#0+CW#1 determined based on the coding rate r lowMCS , that is, an appropriate amount of resource is used for transmission, thus ensuring the control information allocated in that CW meets the required reception quality. In the layer containing CW#0 or CW#1 having the higher coding rate, the amount of the resource Q CW#0+CW#1 determined based on the coding rate r lowMCS (that is, the coding rate of the other CW) is used for transmission, but that amount is equal to or more than the appropriate amount of resource. Thus, the control information allocated in that CW can sufficiently meet the required reception quality.
[0070] As shown above, in accordance with Determination Method 1, resource amount determining section 204 uses a CW with the lower coding rate of the coding rates of the plurality of CWs to determine the amount of the resource of control information in each layer. In other words, resource amount determining section 204 uses a CW assigned to a layer in a poor transmission path environment among a plurality of CWs to determine the amount of the resource of control information in each layer, thus ensuring that required reception quality is sufficiently met in all the CWs, including the CW assigned to a layer in a poor transmission path environment. Thus, base station 100 can meet reception quality required by all the CWs (i.e., reception quality required by control information in an LTE system). Accordingly, by combining CW#0 and CW#1 into control information, base station 100 can ensure that the combined control information can meet the required reception quality, and prevent the degradation of reception quality of the control information.
<Determination Method 2>
[0071] In Determination Method 2, resource amount determining section 204 determines the amount of the resource of control information in each layer based on the average of the inverses of the coding rates of the two CWs. More specifically, resource amount determining section 204 determines the amount of the resource Q CW#0+CW#1 of control information in each layer in accordance with equation 4 below.
[0000]
(
Equation
4
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
×
1
r
CW
#0
+
1
r
CW
#1
2
×
β
offset
PUSCH
/
L
⌉
[
4
]
[0072] In equation 4, r CW#0 indicates the coding rate of CW#0 and r CW#1 indicates the coding rate of CW#1.
[0073] Resource amount determining section 204 , as shown in equation 4 and as in equation 1, determines the amount of the resource of control information in each layer by multiplying an average of the inverse (1/r CW#0 ) of the coding rate r CW#0 and the inverse (1/r CW#1 ) of the coding rate r CW#1 by an amount of offset β offset PUSCH and dividing the result by the total number of layers L.
[0074] One bit of the control information allocated in CW#0 is coded into (1/r CW#0 ) bit. Likewise, one bit of the control information allocated in CW#1 is coded into (1/r CW#1 ) bit. In other words, the average of the number of bits obtained by coding one bit of the control information in each CW ((1/r CW#0 )+(1/r CW#1 )/2) corresponds to the average of the number of bits appropriate for combining CW#0 and CW#1. Thus, the average of the inverses of the CW coding rates ((1/r CW#0 )+(1/r CW#1 )/2) equals the inverse of the coding rate of a combined CW obtained by combining CW#0 and CW#1.
[0075] In accordance with Determination Method 1 (equation 3), the amount of resource is determined based on the lower coding rate of the coding rates of the two CWs (i.e., CW#0 and CW#1). This means that an appropriate amount of resource is determined for the layer containing a CW with the lower coding rate among CW#0 and CW#1, while an amount of resource equal to or more than an appropriate amount of resource is determined for the layer containing the other CW (i.e., CW with the higher coding rate), which results in wasteful use of resource.
[0076] In contrast, in accordance with Determination Method 2, resource amount determining section 204 determines the amount of resource of control information in each layer based on the inverse of the coding rate of a combined CW obtained by combining CW#0 and CW#1 (the average of the inverses of the coding rates of CW#0 and CW#1).
[0077] an amount of resource smaller than that determined by Determination Method 1 for the layer containing a CW with a higher coding rate between CW#0 and CW#1 is determined. In other words, Determination Method 2 can reduce more wasteful use of resource than Determination Method 1 for a layer allocated to a CW with the higher coding rate. In contrast, an amount of resource less than an appropriate amount of resource is determined for a layer allocated to a CW having the lower coding rate. As described above, since resource amount determining section 204 determines the amount of the resource such that a combined CW obtained by combining all the CWs can meet required reception quality, base station 100 combines CW#0 and CW#1 and ensures that the combined control information can meet required reception quality.
[0078] As described above, in accordance with Determination Method 2, resource amount determining section 204 determines the amount of resource required to assign control information in each layer based on the average of the inverses of the coding rates of the plurality of CWs. This prevents the degradation of reception quality of control information while reducing wasteful use of resources.
<Determination Method 3>
[0079] In Determination Method 3, resource amount determining section 204 determines the amount of the resource of control information in each layer based on the inverse of the coding rate of one of the two CWs and a correction factor notified from base station 100 . More specifically, resource amount determining section 204 determines the amount of the resource Q CW#0+CW#1 of control information in each layer in accordance with equation 5 below.
[0000]
(
Equation
5
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
×
1
r
CW
#0
×
β
offset
PUSCH
×
γ
offset
/
L
⌉
[
5
]
[0080] In equation 5, r CW#0 indicates the coding rate of CW#0 and γ offset indicates a correction factor notified from base station 100 as a control parameter.
[0081] Resource amount determining section 204 , as shown in equation 5 and as in equation 1, determines the amount of the resource of control information in each layer by multiplying the inverse (1/r CW#0 ) of the coding rate r CW#0 by an amount of offset β offset PUSCH , further multiplying the resulting resource amount by a correction factor γ offset , and dividing the result by the total number of layers L.
[0082] An exemplary correction factor γ offset notified from base station 100 is shown in FIG. 6 . Base station 100 selects a correction factor γ offset based on a difference in coding rate between two CW#0 and CW#1 (difference in reception quality) or a coding rate ratio between CW#0 and CW#1 (ratio of reception quality).
[0083] More specifically, if the coding rate of a single CW (coding rate r CW#0 of CW#0 in this case) used to determine the amount of the resource of control information is lower than the coding rate of the other CW (coding rate r CW#1 of CW#1 in this case), base station 100 uses a correction factor γ offset of a value less than 1.0 (any of the correction factors for the signaling #A to #C shown in FIG. 6 ).
[0084] On the other hand, if the coding rate of a single CW (coding rate r CW#0 of CW#0 in this case) used to determine the amount of the resource of control information is higher than the coding rate of the other CW (coding rate r CW#1 of CW#1 in this case), base station 100 uses a correction factor γ offset exceeding 1.0 (one of correction factors for the signaling #E and #F shown in FIG. 6 ).
[0085] The smaller the difference in coding rate between the CWs (difference in reception quality) is, the closer to 1.0 the correction factor γ offset selected by base station 100 is (if there is no difference in coding rate between the CWs (i.e., the rates are identical), the correction factor for signaling #D shown in FIG. 6 (1.0) is selected).
[0086] Base station 100 notifies terminal 200 of setting information including control parameters including the selected correction factor γ offset (the signaling number of the correction factor γ offset ) via the upper layers.
[0087] As described above, resource amount determining section 204 uses a correction factor γ offset set in accordance with a difference in coding rate (a difference in reception quality) between the two CWs to correct the amount of the resource determined based on the coding rate (inverse) of one of the two CWs.
[0088] As shown above, determination of the amount of the resource based on the inverse of the lower coding rate of the coding rates of the two CWs (coding rate r CW#0 of CW#0 in this case) results in setting of an excess amount of resource for the other CW (CW#1 in this case), for example. To cope with this problem, resource amount determining section 204 can reduce the excess use of resource for the other CW (CW#1 in this case) by multiplying the amount of the resource determined based on the inverse of the lower coding rate by a correction factor γ offset of a value less than 1.0. Likewise, determination of the amount of the resource based on the inverse of the higher coding rate of the coding rates of the two CWs results in an insufficient amount of resource for the other CW. To address this problem, resource amount determining section 204 can increase the amount of the resource of the other CW by multiplying the amount of the resource determined based on the inverse of the higher coding rate by a correction factor γ offset of a value exceeding 1.0.
[0089] As described above, equation 5 corrects the amount of the resource determined based on the coding rate of one of CWs (coding rate r CW#0 of CW#0 in this case) with a correction factor γ offset set in accordance with a difference in coding rate between the two CWs, thereby allowing the calculation of the amount of the resource based on the two CWs (i.e., required reception quality of a combined CW obtained by combining the two CWs).
[0090] To put it differently, resource amount determining section 204 corrects the coding rate (inverse) of one of the two CWs in accordance with the difference in coding rate between the two CWs. More specifically, resource amount determining section 204 adjusts the corrected coding rate such that the coding rate is approximated to the average of the coding rates of the two CWs by adopting a larger correction factor (γ offset ) for the coding rate (i.e., inverse) of one of the two CWs in response to a larger difference in coding rate between the two CWs. Accordingly, the inverse of the corrected coding rate (γ offset /r CW#0 in equation 5) corresponds to the average of the inverses of the coding rates of the two CWs (i.e., the value to which the corrected coding rate is approximated). Resource amount determining section 204 determines the amount of the resource of control information in each layer based on the average of the inverses of the coding rates of the two CWs (i.e., the inverse of the corrected coding rate (γ offset /r CW#0 in equation 5).
[0091] As shown above, in accordance with Determination Method 3, resource amount determining section 204 determines the amount of the resource required to allocate control information in each layer based on the inverse of the coding rate of one CW and a correction factor set in accordance with a difference in coding rate between the two CWs. In this manner, the amount of the resource in consideration of both of the two CWs can be determined, which in turn, prevents the degradation in reception quality of control information while reducing wasteful use of resource.
[0092] In accordance with Determination Method 3, even in the case where the coding rate of one of the two CWs (coding rate r CW#0 of CW#0 in equation 5) is extremely low (for example, r CW#0 is infinitely close to 0), assignment of an excessive amount of resource to control information can be prevented by multiplying the amount of the resource calculated based on the coding rate r CW#0 by a correction factor γ offset set in accordance with a difference in coding rate between the two CWs. This means that the correction factor can prevent the assignment of an excessive assignment of resources.
[0093] If it is pre-determined that the lower coding rate of the coding rates of the two CWs is used to determine the amount of the resource Q CW#0+CW#1 , instead of the coding rate r CW#0 of CW#0 shown in equation 5, only correction factors γ offset of values equal to 1.0 or lower may be used as candidates. For example, among the candidates for correction factor γ offset in FIG. 6 , only the correction factors γ offset for the signaling #A to #D may be set. This leads to a reduction in the amount of signaling used for notification of the correction factors γ offset .
[0094] Likewise, if it is pre-determined that the higher coding rate of the coding rates of the two CWs is used to determine the amount of the resource Q CW#0+CW#1 , instead of the coding rate r CW#0 of CW#0 shown in equation 5, only correction factors γ offset of values equal to 1.0 or higher may be used as candidates. For example, among the candidates for correction factor γ offset in FIG. 6 , only the correction factors γ offset for the signaling #D to #F may be set. This leads to a reduction in the amount of signaling used for notification of the correction factors γ offset .
[0095] A plurality of correction factor γ offset candidate tables may be provided and switched depending on whether the coding rate r CW#0 of CW#0 in equation 5 is the lower or higher coding rate of the coding rates of two CWs. For example, if the coding rate r CW#0 of CW#0 in equation 5 is the lower coding rate of the coding rates of the two CWs, a candidate table containing the correction factors γ offset for the signaling #A to #D shown in FIG. 6 may be used. In contrast, if the coding rate r CW#0 of CW#0 in equation 5 is the higher coding rate of the coding rates of the two CWs, a candidate table containing correction factors γ offset for the signaling #D to #E shown in FIG. 6 may be used.
<Determination Method 4>
[0096] Determination Method 4 is identical to Determination Method 3 (equation 5) in that the amount of the resource of control information is calculated based on the coding rate (inverse) of one of the two CWs, except for the calculation method of the correction factor.
[0097] Hereinafter, Determination Method 4 is described in details.
[0098] Since the two CWs to which control information is allocated are combined at base station 100 as described above, focusing on “reception quality of one” of the two CWs, reception quality of (“reception quality of a combined CW”/“reception quality of one of the two CWs”) fold is obtained after combining the two CWs. The “reception quality of a combined CW” is obtained when the two CWs are combined.
[0099] To maintain the reception quality required for the entire CWs, the correction factor for the amount of the resource of control information calculated based on the coding rate (inverse) of one of CWs may be set to (“reception quality of one of CWs”/“reception quality of a combined CW”). This ensures the reception quality necessary to maintain the reception quality required by each CW to which control information is allocated at a minimum amount of resource required after combination of the two CWs.
[0100] In general, the following relationship holds between the reception quality and the coding rate: The higher the reception quality of a signal is, the higher the coding rate of the signal is. Thus, (“coding rate of one of CWs”/“coding rate of a combined CW”) can be substituted for (“reception quality of one of CWs”/“reception quality of a combined CW”) as a correction factor. The “coding rate of a combined CW” is obtained by combining two CWs.
[0101] Resource amount determining section 204 uses equation 6 below to set a correction factor γ offset which is represented by (“coding rate of one of CWs (r CW#0 )”/“coding rate of a combined CW (r CW#+CW#1 )”). In equation 6, the coding rate r CW#0 of CW#0 of the CW#0 and CW#1 is used as the “coding rate of one of CWs”.
[0000]
(
Equation
6
)
γ
offset
=
coding
rate
of
one
of
CWs
(
r
CW
#0
)
coding
rate
of
a
combined
CW
(
r
CW
#0
+
CW
#1
)
=
r
CW
#0
×
M
CW
#0
sc
PUSCH
-
initial
·
N
CW
#0
symb
PUSCH
-
initial
+
M
CW
#1
sc
PUSCH
-
initial
·
N
CW
#1
symb
PUSCH
-
initial
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
[
6
]
[0102] In equation 6, M CW#SC PUSCH-initial indicates a PUSCH transmission bandwidth for CW#0, M CW#1SC PUSCH-initial indicates a PUSCH transmission bandwidth for CW#1, N CW#0Symb PUSCH-initial indicates the number of transmission symbols in PUSCH per unit transmission bandwidth for CW#0, and N CW#1Symb PUSCH-initial indicates the number of transmission symbols in PUSCH per unit transmission bandwidth for CW#1. C CW#0 indicates the number of code blocks into which a data signal allocated in CW#0 is divided, C CW#1 indicates the number of code blocks into which a data signal allocated in CW#1 is divided, K r CW#0 indicates the number of bits in each code block in CW#0 and K r CW#1 indicates the number of bits in each code block in CW#1. For example, if CW#0 is assigned to two layers and assigned to 12 transmission symbols and has 12 sub-carriers in each layer, the amount of the resource of CW#0 (M CW#0SC PUSCH-initial ·N CW#0Symb PUSCH-initial ) is 288 (RE). To be more precise, the M CW#0SC PUSCH-initial equals 12 sub-carriers, and the N CW#0Symb PUSCH-initial equals 24 transmission symbols (two layers each have 12 transmission symbols); thus, the amount of the resource of CW#0 (M CW#0SC PUSCH-initial ·N CW#0Symb PUSCH-initial ) is 288 (=12×24). Note that M CW#0 SC PUSCH-initial , M CW#1SC PUSCH-initial , N CW#0Symb PUSCH-initial and N CW#1Symb PUSCH-initial represent values at initial transmission.
[0103] (M CW#0SC PUSCH-initial ·N CW#0Symb PUSCH-initial +M CW#1SC PUSCH-initial ·N CW#1Symb PUSCH-initial ) shown in equation 6 indicates the total amount of transmission resources of respective data signals in CW#0 and CW#1, and (ΣK r CW#0 +ΣK r CW#1 ) indicates the total number of transmission symbols in a PUSCH (or the total number of bits in CW#0 and CW#1) to which respective data signals in CW#0 and CW#1 (all code blocks) are assigned. Accordingly, (M CW#0SC PUSCH-initial ·N CW#0Symb PUSCH-initial +M CW#1SC PUSCH-initial ·N CW#1Symb PUSCH-initial )/(ΣK r CW#0 +ΣK r CW#1 ) shown in equation 6 indicates the inverse of the coding rate of a combined CW (1/(coding rate of a combined CW (r CW#0+CW#1 ))).
[0104] Resource amount determining section 204 assigns the correction factor γ offset shown in equation 6 to, for example, equation 5. Resource amount determining section 204 determines the amount of the resource of control information Q CW#0+CW#1 in each layer in accordance with equation 7 below:
[0000]
(
Equation
7
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
M
CW
#0
sc
PUSCH
-
initial
·
N
CW
#0
symb
PUSCH
-
initial
+
M
CW
#1
sc
PUSCH
-
initial
·
N
CW
#1
symb
PUSCH
-
initial
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
·
β
offset
PUSCH
/
L
⌉
[
7
]
[0105] Resource amount determining section 204 , as shown in equation 7 and as in equation 1, determines the amount of the resource of control information in each layer by multiplying the inverse (1/r CW#0 ) of the coding rate r CW#0 by an amount of offset β offset PUSCH to obtain an amount of resource, multiplying the resulting amount of resource by a correction factor γ offset , and then dividing the result by the total number of layers L.
[0106] the result obtained by multiplying the inverse (1/r CW#0 ) of the “coding rate of one of CWs (r CW#0 )” in equation 5 by a correction factor γ offset shown in equation 6 (“coding rate of one of CWs (r CW#0 )”/“coding rate of a combined CW (r CW#0+CW#1 )”) is equivalent to the inverse of the coding rate of a CW obtained by combining CW#0 and CW#1 (1/(coding rate of a combined CW (r CW#0+CW#1 ))). In other words, the inverse of the coding rate of a combined CW (1/(coding rate of a combined CW (r CW#0+CW#1 ))), that is, the average of the inverses of the coding rates of the two CWs can be obtained by correcting the inverse of the coding rate of one of the two CWs (1/r CW#0 ) with a correction factor γ offset (equation 6). Accordingly, resource amount determining section 204 uses the inverse of the coding rate of a combined CW as the average of the inverses of the coding rates of the two CWs to determine the amount of the resource of control information in each layer.
[0107] As shown above, in Determination Method 4, resource amount determining section 204 determines the amount of the resource required to allocate control information in each layer based on the inverse of the coding rate of one of CWs, and the correction factor calculated based on the ratio of reception quality (i.e., the ratio of coding rates) between the two CWs. In other words, resource amount determining section 204 uses the ratio between the coding rate (reception quality) of one of CWs and the coding rate (reception quality) of a combined CW obtained by combining the two CWs, that is, the ratio of coding rates (i.e., ratio of reception quality) between the two CWs as a correction factor. This allows resource amount determining section 204 to obtain the reception quality necessary to maintain the reception quality required by each CW to which control information is allocated at a minimum amount of resource required. As shown above, Determination Method 4 can determine the amount of the resource in consideration of both the two CWs, thus preventing the degradation of reception quality of control information without wasteful use of resource.
[0108] Furthermore, Determination Method 4 allows terminal 200 to calculate a correction factor based on the coding rates (reception quality) of the two CWs, thus eliminating the need for base station 100 to notify terminal 200 of a correction factor, unlike in Determination Method 3. More specifically, Determination Method 4 can reduce the amount of signaling from base station 100 to terminal 200 , as compared with Determination Method 3.
[0109] In Determination Method 4, the denominator of the correction factor γ offset shown in equation 6 indicates the total number of bits in CW#0 and CW#1. Accordingly, even if the coding rate of either CW#0 or CW#1 is extremely low (data size is extremely small), the correction factor γ offset is determined, taking the coding rate of the other CW into account, thereby preventing assignment of an excess amount of resource to the control information.
<Determination Method 5>
[0110] If the same control information is transmitted in a plurality of layers at the same time and at the same frequency, that is, if a rank-1 transmission is performed, the amount of the resource allocated to control information transmitted in each of a plurality of layers is equal.
[0111] In such a case, resource amount determining section 204 should preferably determine the amount of the resource of control information in each layer based on the number of bits that can be transmitted in the same amount of resource (for example, a certain number of REs (for example, a single RE)) in each layer.
[0112] More specifically, the coding rate r CW#0 of CW#0 indicates the number of bits in CW#0 that can be transmitted using a single RE, and the coding rate r CW#1 of CW#1 indicates the number of bits in CW#1 that can be transmitted using a single RE. Assuming that the number of layers in which CW#0 is allocated is indicated by L CW#0 and the number of layers in which CW#1 is allocated is indicated by L CW#1 , and the number of bits W RE that can be transmitted using a single RE in all the layers ((L CW#0 +L CW#1 ) layers) is obtained from equation 8:
[0000] W RE =r CW#0 ×L CW#0 +r CW#1 ×L CW#1 (Equation 8)
[0113] To put it more specifically, this equation indicates that each layer can transmit (W RE /(L CW#0 +L CW#1 )) bits of data signal using a single RE on average. Namely, (W RE /L CW#0 +L CW#1 )) may be used as the average of coding rates (i.e., the number of bits that can be transmitted using a single RE) of a CW allocated to each layer. This achieves reception quality necessary to maintain the reception quality required by each CW to which the control information is allocated at a minimum amount of resource required after combination of the two CWs transmitted in a plurality of layers.
[0114] Resource amount determining section 204 , in accordance with equation 9 below, determines the amount of the resource of control information Q CW#0+CW#1 in each layer based on the inverse of the average of the coding rates of the CWs assigned to each layer ((r CW#0 ×L CW#0 +r CW#1 ×L CW#1 )/(L CW#0 +L CW#1)).
[0000]
(
Equation
9
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
L
CW
#0
+
L
CW
#1
r
CW
#0
×
L
CW
#0
+
r
CW
#1
×
L
CW
#1
·
β
offset
PUSCH
/
L
⌉
[
9
]
[0115] Resource amount determining section 204 , as shown in equation 9 and as in equation 1, determines the amount of the resource of control information in each layer by multiplying the inverse of the average of the coding rates of the CWs assigned to each layer ((L CW#0 +L CW#1 )/(r CW#0 ×L CW#0 +r CW#1 ×L CW#1 )) by the amount of offset β offset PUSCH and then dividing the result by the total number of layers L.
[0116] The average of the coding rates of the CWs assigned to each layer ((r CW#0 ×L CW#0 +r CW# 1 ×L CW#1 )/(L CW#0 +L CW#1 )), as shown in equation 9, can be represented by r CW#0 ×(L CW#0 /(L CW#0 +L CW#1 ))+r CW#1 ×(L CW#1 /(L CW#0 +L CW#1 )). This indicates that the coding rate r CW#0 of CW#0 is weighted by the proportion of the number of layers to which CW#0 is assigned (L CW#0 ) in all the number of layers (L CW#0 +L CW#1 ), and that the coding rate r CW#1 of CW#1 is weighted by the proportion of the number of layers to which CW#1 is assigned (L CW#1 ) in all the number of layers (L CW#0 +L CW#1 ).
[0117] In other words, resource amount determining section 204 weights the coding rate of each CW by the proportion of the number of layers to which the CW is assigned in all the layers to which a plurality of CWs are assigned. To be more precise, the greater the proportion of the number of layers to which a CW is assigned in all the layers to which a plurality of CWs are assigned is, the greater the weight given to the coding rate of the CW is. For example, in Determination Method 2 (equation 4), the average of the coding rates of the two CWs is simply calculated, and the number of layers to which each CW is assigned is not taken into account. In contrast, in Determination Method 5 (equation 9), the average of the coding rates of a CW in all the layers containing the CW can be calculated accurately.
[0118] As shown above, in accordance with Determination Method 5, resource amount determining section 204 determines the amount of the resource of control information in each layer using the average of the numbers of bits that can be transmitted in the same amount of resource (for example, a single RE) in each layer as the average of the coding rates of the CWs allocated to each layer. In this manner, the amount of the resource in consideration of the two CWs assigned to a plurality of layers can be determined. Thus, the degradation of reception quality of control information can be prevented without wasteful use of resource.
[0119] Since the rank-1 transmission is used for control information, the amount of resource is identical for each layer. In contrast, a transmission mode other than the rank-1 transmission may be used for data signals, in which case the amount of the resource varies depending on layers. In such a case, the same amount of resource is assumed for each layer and the average number of transmittable bits is calculated, as shown in Determination Method 5, which allows calculation of an appropriate amount of resource. In other words, Determination Method 5 is applicable to data signals with different transmission bandwidths. Suppose, for example, that, on initial transmission (i.e., in sub-frame 0 ), CW#0 is responded with ACK and CW#1 is responded with NACK, and on retransmission (i.e., in sub-frame 8 ), a new packet is assigned for CW#0 and a retransmission packet is assigned for CW#1. In this case, there may be a case where the transmission bandwidth differs between the new packet and the retransmission packet in sub-frame 8 . In this case, the amount of the resource of control information is calculated by assigning the information on CW#0 that is transmitted initially in sub-frame 8 as CW#0 information, and the information on CW#1 that was transmitted initially in sub-frame 0 in equation 9 as CW#1 information. This method allows calculations of the amount of the resource, assuming that each layer uses the same amount of resource to transmit control information, and is effective when the same control information in a plurality of layers is transmitted at the same time and at the same frequency, that is, when rank-1 transmission is performed.
[0120] Furthermore, Determination Method 5 allows terminal 200 to calculate the correction factor based on the coding rates (reception quality) of the two CWs, thereby eliminating the need for base station 100 to notify terminal 200 of the correction factor, unlike in Determination Method 3. Accordingly, Determination Method 5 can reduce the amount of signaling from base station 100 to terminal 200 , as compared with Determination Method 3.
[0121] In Determination Method 5, the denominator of the portion corresponding to the inverse of the coding rates in equation 9 ((L CW#0 +L CW#1 )/(r CW#0 ×L CW#0 +r CW#1 ×L CW#1 )) indicates the total number of bits transmittable using a single RE in all the layers to which CW#0 and CW#1 are assigned. This can prevent assignment of an excess amount of resource to control information since the coding rate of the other CW is taken into account, even if either CW#0 or CW#1 has an extremely lower coding rate (extremely small data size).
[0122] Assuming that the same amount of resource is assigned to layers to each of which a CW is assigned, the following equations are obtained: M CW#0SC PUSCH-initial ·N CW#0Symb PUSCH-initial =M SC PUSCH-initial(0) ·N Symb PUSCH-initial(0) ·L CW#0 and M CW#1SC PUSCH-initial ·N CW#1Symb PUSCH-initial =M SC PUSCH-initial(1) ·N Symb PUSCH-initial(1) ·L CW#1 . The M SC PUSCH-initial(0) ·N Symb PUSCH-initial(0) indicates an amount of the resource of data signals on initial transmission for each of layers to which CW#0 is assigned, and the M SC PUSCH-initial(1) ·N Symb PUSCH-initial(1) indicates an amount of the resource of data signals on initial transmission for each of layers to which CW#1 is assigned. Equation 9 can be simplified to equation 10 using the abovementioned equations. Since L CW#0 +L CW#1 =L, equation 10 is equivalent to equation 11.
[0000]
(
Equation
10
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
L
CW
#0
+
L
CW
#1
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
M
CW
#0
sc
PUSCH
-
initial
·
N
CW
#0
symb
PUSCH
-
initial
×
L
CW
#0
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
M
CW
#1
sc
PUSCH
-
initial
·
N
CW
#1
symb
PUSCH
-
initial
×
L
CW
#1
·
β
offset
PUSCH
/
L
⌉
=
⌈
(
O
+
P
)
·
L
CW
#0
+
L
CW
#1
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
M
sc
PUSCH
-
initial
(
0
)
·
N
symb
PUSCH
-
initial
(
0
)
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
M
sc
PUSCH
-
initial
(
1
)
·
N
symb
PUSCH
-
initial
(
1
)
·
β
offset
PUSCH
/
L
⌉
[
10
]
(
Equation
11
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
1
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
M
sc
PUSCH
-
initial
(
0
)
·
N
symb
PUSCH
-
initial
(
0
)
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
M
sc
PUSCH
-
initial
(
1
)
·
N
symb
PUSCH
-
initial
(
1
)
·
β
offset
PUSCH
⌉
[
11
]
[0123] Assuming that the same amount of resource is assigned to each of layers to which a CW is assigned (W layer =M SC PUSCH-initial ·N Symb PUSCH-initial ), equation 9 can be simplified to equation 12.
[0000]
(
Equation
12
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
L
CW
#0
+
L
CW
#1
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
M
CW
#0
sc
PUSCH
-
initial
·
N
CW
#0
symb
PUSCH
-
initial
×
L
CW
#0
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
M
CW
#1
sc
PUSCH
-
initial
·
N
CW
#1
symb
PUSCH
-
initial
×
L
CW
#1
·
β
offset
PUSCH
/
L
⌉
=
⌈
(
O
+
P
)
·
L
CW
#0
+
L
CW
#1
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
L
CW
#0
×
W
layer
×
L
CW
#0
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
L
CW
#1
×
W
layer
×
L
CW
#1
·
β
offset
PUSCH
/
L
⌉
=
⌈
(
O
+
P
)
·
L
CW
#0
+
L
CW
#1
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
W
layer
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
W
layer
·
β
offset
PUSCH
/
L
⌉
=
⌈
(
O
+
P
)
·
(
L
CW
#0
+
L
CW
#1
)
×
W
layer
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
·
β
offset
PUSCH
/
L
⌉
[
12
]
[0124] ((L CW#0 +L CW#1 )×W layer ) in equation 12 is equivalent to equation 13 below:
[0000] M CW#0sc PUSCH-initial ·N CW#0symb PUSCH-initial +M CW#1sc PUSCH-initial ·N CW#1symb PUSCH-initial (Equation 13)
[0125] Since W layer =M SC PUSCH-initial ·N Symb PUSCH-initial and L CW#0 +L CW#1 =L, equation 10 can be simplified to equation 14 below:
[0000]
(
Equation
14
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
M
SC
PUSCH
-
initial
·
N
symb
PUSCH
-
initial
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
·
β
offset
PUSCH
⌉
[
14
]
[0126] Determination Methods 1 to 5 for determining the amount of the resource of control information have been described.
[0127] ACK/NACK and CQI receiving section 111 of base station 100 determines the amount of the resource of control information (ACK/NACK signals or CQIs) in a reception signal using a method similar to Determination Methods 1 to 5 used in resource amount determining section 204 . Based on the determined amount of the resource, ACK/NACK and CQI receiving section 111 extracts an ACK/NACK or CQI to downlink data (PDSCH signals) sent by each terminal from a channel (for example, PUSCH) to which uplink data signals have been assigned.
[0128] As shown above, this embodiment can prevent the degradation in reception quality of control information even in the case of adopting the SU-MIMO transmission method.
Embodiment 2
[0129] In Embodiment 1, the amount of the resource of control information is determined based on the lower coding rate of the coding rates of the two CWs (code words) or the average of the inverses of the coding rates of the two CWs. Meanwhile, in Embodiment 2, besides the processing in Embodiment 1, the amount of the resource of control information is determined in consideration of a difference in interference between layers for data signals and for control information.
[0130] Since the basic configurations of the base station and the terminal in accordance with Embodiment 2 are the same as those in Embodiment 1, FIGS. 4 and 5 are used to describe Embodiment 2.
[0131] Besides the processing similar to that of Embodiment 1, setting section 101 ( FIG. 4 ) in base station 100 in accordance with Embodiment 2 sets a correction factor (α offset (L)).
[0132] Besides the processing similar to that of Embodiment 1, ACK/NACK and CQI receiving section 111 determines the amount of the resource using the correction factor (α offset (L)) received from setting section 101 .
[0133] Meanwhile, resource amount determining section 204 in terminal 200 according to Embodiment 2 ( FIG. 5 ) uses a correction factor (α offset (L)) notified from base station 100 to determine the amount of the resource.
(Operations of Base Station 100 and Terminal 200 )
[0134] The operations of base station 100 and terminal 200 having the above-mentioned configurations will be described below:
<Determination Method 6>
[0135] If the number of layers or the number of ranks for control information equals the number of layers or the number of ranks for data signals, the same inter-layer interference occurs between data signals and control information. For example, if spatial multiplexing is performed with CW#0 to which control information is allocated and which is assigned to layer #0 and CW#1 containing data signals assigned to layer #1, a rank-2 transmission is performed for data signals and for control information, causing inter-layer interference of the same level.
[0136] Alternatively, if the number of ranks differs between control information and data signals, different inter-layer interference occurs between data signals and control information. If the same control information is allocated in CW#0 and CW#1 and transmitted in layer #0 and layer #1, that is, if a rank-1 transmission is performed, less inter-layer interference occurs, as compared with when different signals are allocated in CW#0 and CW#1 and transmitted in layer #0 and layer #1.
[0137] In this respect, resource amount determining section 204 increases or decreases the amount of the resource calculated with an above equation (for example, equation 1), depending on the number of ranks or the number of layers for data signals and for control information.
[0138] More specifically, resource amount determining section 204 , as shown in equation 15 below, calculates the amount of the resource Q CW#0+CW#1 by determining the amount of the resource of control information in each layer based on the coding rate of one of CWs (CW#0 or CW#1) or the coding rates of both CWs using the above equation 1, multiplying the determined amount of the resource by a correction factor α offset (L) which depends on the number of ranks or the number of layers, and then dividing the result of multiplication by the total number of layers L.
[0000]
(
Equation
15
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
×
1
r
CW
#0
×
β
offset
PUSCH
/
L
×
α
offset
(
L
)
⌉
[
15
]
[0139] In equation 15, α offset (L) represents a correction factor that depends on the number of layers or the number of ranks for data signals and for control information.
[0140] For example, if the number of ranks or the number of layers for data signals is larger than that of control information, the correction factor α offset (L), as shown in FIG. 7 , implicitly decrease as a difference in the number of ranks or the number of layers between data signals and control information increases. As the difference in the number of ranks or the number of layers between data signals and control information decreases, the correction factor is approximated to 1.0.
[0141] Alternatively, if the number of ranks or the number of layers for data signals is smaller than that for control information, the correction factor α offset (L), as shown in FIG. 8 , implicitly increases as a difference in the number of ranks or the number of layers between data signals and control information increases.
[0142] The inter-layer interference is dependent on channel variations (or channel matrix): thus, inter-layer interference varies even if the number of ranks or the number of layers is identical, which means an appropriate correction is difficult using one set value. To cope with this problem, a plurality of correction factors α offset shared between base station 100 and terminal 200 are provided in each layer to allow base station 100 to select one from the correction factors and notify terminal 200 via upper layers or PDCCH. Terminal 200 receives the correction factor α offset from base station 100 and uses it to calculate the amount of the resource, as in Determination Method 6. Base station 100 may report the amount of offset β offset PUSCH for each layer (or each rank).
[0143] the amount of the resource can be set in consideration of a difference in inter-layer interference between data signals and control information. Thus, the degradation of reception quality of control information can be prevented, while wasteful use of resource can be reduced.
[0144] Since inter-layer interference is dependent on channel variations (or channel matrix), upper layers cannot change channels frequently. To cope with frequently-occurring channel variations, the presence or absence of a correction factor may be reported using one bit in a physical downlink control channel (PDCCH) message having a shorter notification interval than upper layers. The PDCCH message is conveyed in each sub-frame, thereby facilitating flexible switching. Furthermore, use of one bit in the PDCCH to direct switching between use or non-use of the correction factor leads to a reduction in the amount of signaling.
[0145] The above-mentioned correction factor has a variable set value, depending on the control information (ACK/NACK signals and CQIs and/or the like), but a common notification (notification using a common set value) may be used for the control information (ACK/NACK signals and CQIs and/or the like). For example, if a set value 1 is conveyed to a terminal, the terminal selects a correction factor for ACK/NACK signals that corresponds to the set value 1 and a correction factor for CQIs that corresponds to the set value 1. This allows notification using a single set value for a plurality of parts of control information, thereby reducing the amount of signaling for notification of a correction factor.
[0146] this embodiment, the correction factor is increased or decreased, depending on the number of ranks or the number of layers for data signals and for control information, but since the number of layers and the number of ranks are closely related with CWs, the correction factor may be increased or decreased, depending on the number of CWs containing data signals and control information. Furthermore, the correction factor may be changed, depending on whether the number of ranks, the number of layers or the number of CWs for data signals and for control information is equal to or exceeds 1.
Embodiment 3
[0147] Embodiment 1 assumes that the number of layers is identical between initial transmission and retransmission. In contrast, in Embodiment 3, the amount of the resource of control information is determined in consideration of a difference in the number of layers between initial transmission and retransmission in the processing shown in Embodiment 1.
[0148] Since the basic configurations of the base station and the terminal according to Embodiment 3 is the same as those of Embodiment 1, FIGS. 4 and 5 are used to describe Embodiment 3.
[0149] ACK/NACK and CQI receiving section 111 in base station 100 according to Embodiment 3 ( FIG. 4 ) performs processing similar to that of Embodiment 1 and calculates the amount of the resource required to allocate control information based on the number of layers on initial transmission and on retransmission. ACK/NACK and CQI receiving section 111 in Embodiment 3 differs from that in Embodiment 1 in that the equation to calculate the amount of the resource of control information is expanded.
[0150] Meanwhile, resource amount determining section 204 in terminal 200 according to Embodiment 3 ( FIG. 5 ) performs processing similar to that of Embodiment 1 and calculates the amount of the resource required to allocate control information based on the number of layers on initial transmission and retransmission. Resource amount determining section 204 in Embodiment 3 differs from that in Embodiment 1 in that the equation to calculate the amount of the resource of control information is expanded.
(Operations of Base Station 100 and Terminal 200 )
[0151] The operations of base station 100 and terminal 200 having the above-mentioned configurations will be described.
<Determination Method 7>
[0152] Determination Methods 1 to 6 assume that the number of layers is identical between initial transmission and retransmission. On initial transmission, the reception quality that is equal to or greater than a certain level (required reception quality) can be achieved for control information by setting the amount of the resource of control information using, for example, equation 9 (Determination Method 5).
[0153] Since Determination Methods 1 to 6 (for example, equation 9) assume that the amount of the resource of control information is identical for each layer between initial transmission and retransmission, the total amount of the resource of control information in all the layers also decreases due to a reduction in the number of layers when the number of layers is changed on retransmission (for example, decreases). This results in the degradation of reception quality of control information on retransmission, as compared with that on initial transmission (for example, see FIG. 9 ). For example, as shown in FIG. 9 , if allocation notification information (UL grant) is used to change the number of layers from four (on initial transmission) to two (on retransmission), the amount of resource of data signals decreases and thus the total amount of the resource of control information (for example, ACK/NACK signals) also decreases in all the layers.
[0154] resource amount determining section 204 re-sets the amount of the resource of control information on retransmission based on the number of layers in which each CW is allocated on retransmission. More specifically, on retransmission, resource amount determining section 204 does not use the amount of the resource per layer which was calculated on initial transmission, and instead, assigns the number of layers in which each CW is allocated on retransmission (i.e., current number) in equation 9 to re-calculate the amount of the resource per layer on retransmission (i.e., current amount). For the information other than the number of layers (i.e. M CW#0SC PUSCH-initial , M CW#1SC PUSCH-initial , N CW#0Symb PUSCH-initial , N CW#1Symb PUSCH-initial , ΣK r CW#0 and ΣK r CW# ), the numerical values used on initial transmission that have been set to meet a certain error rate requirement (for example, 10%) are used. More specifically, taking L CW#0 +L CW#1 =L into account, equation 9 on retransmission (i.e., currently) can be transformed into equation 16.
[0000]
(
Equation
16
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
1
r
CW
#0
×
L
CW
#0
current
+
r
CW
#1
×
L
CW
#1
current
·
β
offset
PUSCH
⌉
[
16
]
[0155] L CW#0 current and L CW#1 current indicate the number of layers to which CW#0 and CW#1 are assigned on retransmission (i.e., currently), respectively, and L CW#0 initial and L CW#1 initial indicate the number of layers to which CW#0 and CW#1 are assigned on initial transmission, respectively. Since Determination Methods 1 to 6 assume that the number of layers is identical between initial transmission and retransmission, the number of layers is not considered on initial transmission and retransmission. Hence, the number of layers used in Determination Methods 1 to 6 represents the information on initial transmission, just like the number of bits in each CW and/or the amount of the resource in each CW.
[0156] Equation 16 is derived by multiplying each term in the denominator of equation 9 by the ratio of the number of layers on retransmission to that on initial transmission (i.e., L CW#0 current /L CW#0 initial , L CW#1 current /L CW#1 initial ). Equation 17 is derived from equations 16 and 11.
[0000]
(
Equation
17
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
1
r
CW
#0
×
L
CW
#0
initial
×
L
CW
#0
current
L
CW
#0
initial
+
r
CW
#1
×
L
CW
#1
initial
×
L
CW
#1
current
L
CW
#1
initial
·
β
offset
PUSCH
⌉
=
⌈
(
O
+
P
)
·
1
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
M
sc
PUSCH
-
initial
(
0
)
·
N
symb
PUSCH
-
initial
(
0
)
×
L
CW
#0
current
L
CW
#0
initial
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
M
sc
PUSCH
-
initial
(
1
)
·
N
symb
PUSCH
-
initial
(
1
)
×
L
CW
#1
current
L
CW
#1
initial
·
β
offset
PUSCH
⌉
[
17
]
[0157] Equation 19 indicates that if the number of layers for transmitting data signals decreases, the amount of the resource of control information per layer increases. This means that the total amount of resource of layers containing control information is almost identical (i.e., the number of layers containing control information×the amount of the resource of control information per layer) is almost identical) between initial transmission and retransmission, thereby achieving the reception quality that is equal to or exceeds a certain level (required reception quality) for control information even on retransmission (see FIG. 10 .).
[0158] This allows the amount of the resource of control information to be set in consideration of the number of layers on retransmission (currently) even if the number of layers transmitting data signals differs between initial transmission and retransmission. Thus, the degradation of reception quality of control information can be prevented without wasteful use of resource.
[0159] If the ratio of the number of layers on retransmission to that on initial transmission (i.e., the number of layers on retransmission/the number of layers on initial transmission) is 1/A fold (A: integer) for both of CW#0 and CW#1, equation 18 below may be substituted for equation 17.
[0000]
(
Equation
18
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
1
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
M
sc
PUSCH
-
initial
(
0
)
·
N
symb
PUSCH
-
initial
(
0
)
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
M
sc
PUSCH
-
initial
(
1
)
·
N
symb
PUSCH
-
initial
(
1
)
·
β
offset
PUSCH
×
L
current
L
initial
⌉
[
18
]
[0160] L initial and L current indicate the total number of layers on initial transmission and on retransmission, respectively. Unless the above-mentioned condition (i.e., the number of layers on retransmission/the number of layers on initial transmission)=1/A) is met, the amount of the resource of control information may be excessive or insufficient, which results in wasteful use of the resource or low quality. If the probability of not meeting the above condition is low, or if the system is designed so as to avoid such occurrence, resource amount determining section 204 may use equation 18 to calculate the amount of the resource of control information.
[0161] The case in which the total amount of resource (for example, the number of layers) on retransmission is reduced from that on initial transmission has been described above. The total amount of resource (for example, the number of layers) on retransmission may increase from that on initial transmission. In that case, resource amount determining section 204 may use equation 16, 17 or 18 to prevent the assignment of an excess amount of resource to control information.
[0162] The number of layers may be replaced with the number of antenna ports. For example, the number of layers on initial transmission in the above description (i.e., four layers in FIG. 10 ) is replaced with the number of antenna ports (four ports in FIG. 10 ), the number of layers on retransmission (currently) (two layers in FIG. 10 ) is replaced with the number of antenna ports on retransmission (currently) (two ports in FIG. 10 ), and the total number of layers is replaced with the total number of antenna ports. In other words, resource amount determining section 204 replaces the number of layers in equation 16, 17 or 18 with the number of antenna ports to calculate the amount of the resource of control information.
[0163] Note that if the number of layers is defined as the number of antenna ports through which different signaling sequences are transmitted, the number of layers is not always identical to the number of antenna ports. For example, when a rank-1 transmission is performed through four antenna ports, the number of layers is one since the same signaling sequence is transmitted through the four antenna ports. In this case, if a 4-layer transmission is performed using four antenna ports on initial transmission, while a 1-layer transmission (rank-1 transmission) is performed using four antenna ports on retransmission, the amount of the resource of control information need not be corrected. In contrast, if a 4-layer transmission is performed using four antenna ports on initial transmission, while a 1-layer transmission (using one layer) is performed using one antenna port on retransmission, the amount of the resource of control information needs to be corrected.
[0164] If the number of antenna ports used for retransmission decreases, transmission power per antenna port is increased to compensate for the decrease, thereby avoiding the correction of the amount of the resource of control information. For example, if the number of antenna ports is reduced from four to two, the transmission power per antenna port may be increased by 3 dB (i.e., doubled), and if the number of antenna ports is reduced from four to one, the transmission power per antenna port may be increased by 6 dB (i.e., quadruplicated).
[0165] If a precoding vector (or matrix) in which the number of antenna ports used on retransmission is identical to that on initial transmission is used, equation 11 or 14, for example, may be used. If a precoding vector (or matrix) in which the number of antenna ports used on retransmission is different from that on initial transmission is used, for example, the number of layers in equation 16, 17 or 18 may be used with the number of layers replaced with the number of antenna ports.
[0166] Equations 16 and 17 may be applicable to a case in which one of CWs is responded with ACK and the other CW is responded with NACK, resulting in a decrease in the number of CWs. More specifically, if CW#0 is responded with ACK, while CW#1 is responded with NACK on initial transmission, and only CW#1 is thus retransmitted, L CW#0 current=0 is assigned in equation 16 or 17 and the amount of the resource of control information is calculated from equation 19. Equation 19 indicates a case in which only CW1 is responded with NACK, but if only CW0 is responded with NACK, the CW1 information in equation 19 may be replaced with CW0 information.
[0000]
(
Equation
19
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
1
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
M
sc
PUSCH
-
initial
(
1
)
·
N
symb
PUSCH
-
initial
(
1
)
×
L
CW
#1
current
L
CW
#1
initial
·
β
offset
PUSCH
⌉
[
19
]
[0167] If signals are transmitted in the two CWs, equation 11 or 14 may be used. If signals are retransmitted in a single CW, equation 19 may be used as exception processing. For example, if 4-antenna-port transmission is performed using the two CWs on initial transmission and if 2-antenna-port transmission is performed using a single CW on retransmission, equation 19 is used on retransmission. In the fallback mode, which is used when reception quality undergoes extreme degradation, for example, 1-antenna-port transmission may be performed using a single CW on retransmission, in which case equation 19 may be used as exception processing. Equation 19 may incorporate a correction value as shown in equation 20.
[0000]
(
Equation
20
)
Q
CW
#0
+
CW
#1
==
⌈
(
O
+
P
)
·
1
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
M
sc
PUSCH
-
initial
(
1
)
·
N
symb
PUSCH
-
initial
(
1
)
×
W
×
β
offset
PUSCH
⌉
[
20
]
[0168] W in equation 20 indicates a correction factor. Correction value W may be determined based on the number of layers (or number of antenna ports) for CW0 or CW1 on initial transmission and on retransmission. For example, the correction value W in equation 20 is the ratio of number of antenna ports to which CW0 or CW1 is assigned on retransmission to the number of antenna ports to which CW0 or CW1 is assigned on initial transmission. The correction value W may be included in the amount of offset β offset PUSCH . For example, the amount of offsetβ offset PUSCH is determined based on the number of layers (or number of antenna ports) for CW0 or CW1 on initial transmission and on retransmission.
[0169] The case in which the calculation of the amount of resource on retransmission using CW information used in initial transmission has been described. A reason for calculating the amount of the resource on retransmission using CW information used in initial transmission is that the data signal error rate on retransmission may not be set to a constant value such as 10%. More specifically, on initial transmission, a base station allocates resource to each terminal such that the data signal error rate is 10%, while on retransmission the base station is likely to assign a smaller amount of resource to data signals than on initial transmission since it is sufficient as long as an improvement in the initial data signal error rate on retransmission is made. In other words, in the equation calculating the amount of the resource of control information, a reduction in the amount of the resource of data signals (i.e. M SC PUSCH-retransmission ·N Symb PUSCH-retransmission ) on retransmission results in a reduction in the amount of the resource of control information, which leads to the degradation of reception quality of control information. To cope with this problem, the information on initial transmission is used to determine the amount of resource, thereby keeping the reception quality that is equal to or exceeds a certain level (i.e., required reception quality) for control information. Note that ΣK r , ΣK r CW#0 and ΣK r CW#1 are identical between initial transmission and retransmission.
[0170] Even if a data error rate is set to 10% (0.1) on initial transmission, the data signal error rate may exceed 10% due to delay on retransmission (i.e., the error rate may further increase.) To address this problem, preferably, the correction value (K) is multiplied when the amount of the resource on retransmission is determined. For example, as shown in equation 21, the ratio of the number of layers for each CW on initial transmission (L CW#0 initial , L CW#1 initial ) to the number of layers for each CW on retransmission (L CW#0 current , L CW#1 current ) may be multiplied by a correction value specific to the term generated for each CW (K CW#0 , K cw#1 ). Alternatively, as shown in equation 22, the ratio of the number of layers (L initial ) on initial transmission to the number of layers (L current ) on retransmission may be multiplied by the correction value (K). Correction values are not limited to the above-mentioned examples, and one or more time delays may be multiplied by a correction value.
[0000]
(
Equation
21
)
Q
CW
#0
+
CW
#1
==
⌈
(
O
+
P
)
·
1
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
M
sc
PUSCH
-
initial
(
0
)
·
N
symb
PUSCH
-
initial
(
0
)
×
L
CW
#0
current
L
CW
#0
initial
×
K
CW
#0
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
M
sc
PUSCH
-
initial
(
1
)
·
N
symb
PUSCH
-
initial
(
1
)
×
L
CW
#1
current
L
CW
#1
initial
×
K
CW
#1
⌉
[
21
]
(
Equation
22
)
Q
CW
#0
+
CW
#1
=
⌈
(
O
+
P
)
·
1
∑
r
=
0
C
CW
#0
-
1
K
r
CW
#0
M
sc
PUSCH
-
initial
(
0
)
·
N
symb
PUSCH
-
initial
(
0
)
+
∑
r
=
0
C
CW
#1
-
1
K
r
CW
#1
M
sc
PUSCH
-
initial
(
1
)
·
N
symb
PUSCH
-
initial
(
1
)
β
offset
PUSCH
×
L
current
L
initial
×
K
·
⌉
[
22
]
[0171] Unlike Determination Methods 1 to 7, a restriction that the same number of layers as that on initial transmission should be always used on retransmission may be imposed. For example, changing the number of layers for each CW on retransmission with allocation information (UL grant) or the like may be prohibited. ACK/NACKs may be transmitted in the same number of layers as that on initial transmission even if the number of layers for each CW decreases on retransmission.
[0172] The embodiments of the present invention have been described above.
Other Embodiments
[0000]
(1) The MIMO transmission mode in the above-mentioned embodiments may be transmission mode 3 or 4, as set forth in LTE, that is, a transmission mode that supports transmission of two CWs, and the non-MIMO transmission mode may be any other transmission mode, that is, a transmission mode in which only single CW is transmitted. The description of the above-mentioned embodiments has assumed the MIMO transmission mode using a plurality of CWs and the non-MIMO transmission mode using a single CW. More specifically, as described above, the above description has been made on the assumption that signals are transmitted in a plurality of layers (or a plurality of ranks) in the MIMO transmission mode and that signals are transmitted in a single layer (or single rank) in the non-MIMO transmission mode. The transmission modes, however, should not be limited to these examples; signals may be transmitted through a plurality of antenna ports in the MIMO transmission mode (for example, the SU-MIMO transmission) and signals may be transmitted through a single antenna port in the non-MIMO transmission mode.
[0174] The code words in the above-mentioned embodiments may be replaced with transport blocks (TB).
(2) In the above-mentioned embodiments, ACK/NACKs and CQIs are used as examples of control information, but the control information is not limited to the information. Any information (control information) that requires higher reception quality than data signals is applicable. For example, CQIs or ACK/NACKs may be replaced with PMIs (information concerning pre-coding) and/or RI (i.e., information concerning ranks) (3) The term “layer” in the above-mentioned embodiments refers to a virtual transmission path in the space. For example, in the MIMO transmission, data signals generated in each CW are transmitted in different virtual transmission paths (i.e., different layers) in the space at the same time and at the same frequency. The term “layer” may be referred to as a “stream.” (4) In the above-mentioned embodiments, a terminal that determines the amount of resource of control information based on a difference in coding rates between the two CWs to which control information is allocated (or coding rate ratio) has been described. A difference in MCS between the two CWs (or an MCS ratio) may be used, instead of a difference in coding rates between the two CWs to which control information is allocated (or coding rate ratio). Alternatively, a combination of a coding rate and a modulation method may be used as a coding rate. (5) The above-mentioned amount of offset may be referred to as a correction factor, and the correction factor may be referred to as an amount of offset. Any two or three of the correction factors and amounts of offset (α offset (L), β offset PUSCH and γ offset ) used in the above-mentioned embodiments may be combined into one correction factor or offset. (6) In the above-mentioned embodiments, the description has been given with antennas, but the present invention can be applied to antenna ports as well.
[0180] The antenna port refers to a logical antenna composed of one or more physical antennas. Thus, an antenna port does not necessarily refer to one physical antenna, and may refer to an antenna array composed of a plurality of antennas.
[0181] For example, in 3 GPP LTE, how many physical antennas are included in the antenna port is not specified, but an antenna port is specified as a minimum unit allowing the base station to transmit a different reference signal.
[0182] In addition, the antenna port may be specified as a minimum unit in multiplication of a weight of the precoding vector.
[0183] The number of layers may be defined as the number of different data signals transmitted concurrently in the space. Furthermore, the layer may be defined as a signal transmitted through an antenna port associated with data signals or reference signals (or as a communication path thereof in the space). For example, a vector used for weight control (precoding vector) that has been studied for uplink demodulation pilot signals in LTE-A has one-to-one relationship with a layer.
(7) The above-mentioned embodiments have been described by taking an example of the present invention being implemented by hardware, but the present invention may be implemented by software in cooperation with hardware.
[0185] Functional blocks used to describe the above-mentioned embodiments are typically achieved by LSIs, which are integrated circuits. The integrated circuits may be implemented individually into separate chips, or all or part of the integrated circuit may be implemented into one chip. Although such integrated circuits are referred to as LSIs herein, they may be called ICs, system LSIs, super LSIs or ultra LSIs, depending on the degree of integration.
[0186] The methods for manufacturing integrated circuits are not limited to LSIs, and dedicated circuits or general-purpose processors may be used to implement them. After LSI production, field programmable gate arrays (FPGAs) or reconfigurable processors that allow connection or setting of circuit cells within LSIs may be used.
[0187] If advancement in semiconductor technology or other technology derived therefrom leads to emergence of integrated circuit manufacturing technology that takes the place of LSI, obviously, such technology may be used to integrate functional blocks. Biotechnology may also be applicable.
[0188] The entire disclosure of the specifications, drawings and abstracts in Japanese Patent Application No 2010-140751 filed on Jun. 21, 2010 and Japanese Patent Application No 2010-221392 filed on Sep. 30, 2010 are incorporated herein by reference.
INDUSTRIAL APPLICABILITY
[0189] The present invention is useful in mobile communication systems and/or the like.
REFERENCE SIGNS LIST
[0190] 100 base station
[0191] 200 terminal
[0192] 101 setting section
[0193] 102 , 103 coding and modulating section
[0194] 104 , 205 transmission signal generating section
[0195] 105 , 206 transmitting section
[0196] 106 , 201 antenna
[0197] 107 , 202 reception section
[0198] 108 , 208 radio processing section
[0199] 109 , 203 reception processing section
[0200] 110 data reception section
[0201] 111 ACK/NACK and CQI receiving section
[0202] 204 resource amount determining section
[0203] 207 transmission processing section
|
This invention is directed to a terminal apparatus capable of preventing the degradation of reception quality of control information even in a case of employing SU-MIMO transmission system. A terminal ( 200 ), which uses a plurality of different layers to transmit two code words in which control information is placed, comprises: a resource amount determining unit ( 204 ) that determines, based on a lower one of the encoding rates of the two code words or based on the average value of the reciprocals of the encoding rates of the two code words, resource amounts of control information in the respective ones of the plurality of layers; and a transport signal forming unit ( 205 ) that places, in the two code words, the control information modulated by use of the resource amounts, thereby forming a transport signal.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This non-provisional patent application claims priority under 35 U.S.C. §119(a) from Patent Application No. 201610116816.X filed in The People's Republic of China on Mar. 1, 2016.
FIELD OF THE INVENTION
[0002] This invention relates to a vehicle window lift control system and its control method, and in particular to a vehicle window lift control system with an anti-pinch function and its control method.
BACKGROUND OF THE INVENTION
[0003] Many cars are equipped with electric windows to facilitate opening and closing of the windows. Opening and closing of the electric windows are achieved through a vehicle window lift mechanism. The vehicle window lift mechanism typically includes a motor and an associated transmission assembly. However, traditionally, the motor for driving the vehicle window is usually a brushed motor including components such as a stator, a rotor, brushes, and the like, which leads to a relatively large motor size. In addition, as the motor operates, a commutator connected with the rotor and the brushes produce a mutual friction therebetween, which causes the brushes to be easily worn. Therefore, the electric vehicle windows utilizing the brushed motor have a high failure rate and short lifespan. In addition, current electric vehicle windows usually need to include an auto-lift system, and the electric vehicle windows including the auto-lift system need to have an anti-pinch function. Therefore, a switch-type Hall sensor needs to be installed to determine the position of the vehicle window, which greatly dilutes the cost advantages of utilizing the brushed motor.
SUMMARY OF THE INVENTION
[0004] Accordingly, there is a need for a vehicle window lift control system having a relatively smaller size, lower failure rate and reasonable cost, and a vehicle window lift control method.
[0005] A vehicle window lift control system for controlling lifting up or lowering down of a vehicle window includes a window lift motor, a motor drive/control module, an inverter, and a rotor position sensing unit. The window lift motor is a brushless direct current motor. The motor drive/control module is configured to drive the inverter to thereby control rotation of the window lift motor based on a rotor position feedback signal obtained by the rotor position sensing unit. The vehicle window lift control system further includes an anti-pinch module. The anti-pinch module includes a pulse counter, a count comparator, an obstacle judgment unit, and an anti-pinch instruction unit. The pulse counter is configured to record the number of pulses generated by the rotor position sensing unit during lifting up of the vehicle window. The count comparator is configured to compare the recorded number of the pulses against a preset threshold to determine whether or not the vehicle window is in an anti-pinch area. The obstacle judgment unit is initiated when it is determined that the vehicle window is in the anti-pinch area. When the obstacle judgment unit determines that there is an obstacle, the anti-pinch instruction unit sends an anti-pinch instruction to the motor drive/control module, and the motor drive/control module drives the inverter according to the anti-pinch instruction to make the motor rotate reversely.
[0006] A vehicle window lift control method includes the steps of: providing a brushless direct current motor for driving a vehicle window to lift up or lower down; operating the brushless direct current motor according to an external command and a motor position feedback signal; determining whether or not the vehicle window is in an anti-pinch area according to the rotor position feedback signal; determining whether or not the lifting vehicle window meets an obstacle according a motor operating parameter when it is determined that the vehicle window is in the anti-pinch area; and controlling the motor to perform an anti-pinch operation when it is determined that the lifting vehicle window meets an obstacle.
[0007] The vehicle window lift control system of the present invention utilizes the brushless direct current motor, and the anti-pinch operation is performed based on the position feedback signals generated by the rotor position sensing unit that is inherently included in the brushless direct current motor. Therefore, the present vehicle window lift control system has a smaller size, lower failure rate and reasonable cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram of a vehicle window lift control system according to one embodiment of the present invention.
[0009] FIG. 2 is a block diagram of a vehicle window lift control system according to another embodiment of the present invention.
[0010] FIG. 3 is a circuit diagram of the inverter of FIG. 1 .
[0011] FIG. 4 is a circuit diagram of the inventor of FIG. 1 according to another embodiment.
[0012] FIG. 5 is a flow chart of a vehicle window lift control method according to one embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] The present invention will now be described further, by way of example only, with reference to the accompanying drawings.
[0014] Referring to FIG. 1 , a vehicle window lift control system of the present invention is used to control a vehicle window 80 to lift up or lower down. The vehicle window lift control system includes a window lift motor 10 , a motor drive/control module 20 , an inverter 30 , a rotor position sensing unit 40 , and an anti-pinch module 50 .
[0015] The window lift motor 10 is a three-phase or single-phase brushless direct current motor. The window lift motor 10 is connected to the vehicle window 80 through a transmission assembly including a gearbox, traction cables, and the like, such that power outputted from a rotary shaft of the window lift motor 10 is transmitted to the vehicle window 80 to form a traction force for driving the vehicle window 80 to lift up or lower down.
[0016] The motor drive/control module 20 is configured to receive and execute an external command, and have the functions of data processing and driving the inverter 30 . The motor drive/control module 20 includes a command receiving unit 21 , a data processing unit 23 , and a driving unit 25 . The command receiving unit 21 receives an external command, such as an instruction of lifting up, lowering down or stopping the vehicle window that is inputted through a button or a trigger. The data processing unit 23 performs data processing according to the received command to obtain a corresponding motor control signal. The driving unit 25 obtains a regular driving signal according to the motor control signal and drives the inverter 30 to supply or cut off power to various windings of the window lift motor 10 , thereby starting the motor 10 in a desired direction or stopping the motor 10 .
[0017] Since the window lift motor 10 is a brushless direct current motor, in order to ensure continuous operation of the window lift motor 10 , the rotor position sensing unit 40 is required to detect a position of the motor rotor, and upon the motor rotor 50 rotating over a preset position, the motor drive/control module 20 drives the inverter 30 to make the motor 10 run continuous. Specifically, the data processing unit 23 of the motor drive/control module 20 is connected to the rotor position sensing unit 40 to receive a position feedback signal from the rotor position sensing unit 40 . The data processing unit 23 generates commutation instruction according to the position feedback signal, and the driving unit 25 drives the inverter 30 to perform proper commutation, thereby ensuring continuous rotation of the window lift motor 10 and hence achieving the control of automatic lifting up or lowering down of the vehicle window 80 . The rotor position sensing unit 40 includes one or more switch-type Hall sensors. Each of the switch-type Hall sensors generates a continuous square wave signal as the motor operates.
[0018] In one embodiment, the motor drive/control module 20 further includes a rotation direction judgment unit 27 to judge a motor actual rotating direction and judge whether the motor actual rotating direction is consistent with the control command received by the command receiving unit 21 , and generate a failure signal when the motor actual rotating direction is inconsistent with the control command It is noted that, when the rotation direction judgment unit 27 is included, the rotor position sensing unit 40 includes at least two switch-type Hall sensors, and the rotation direction judgment unit 27 judges the motor rotating direction according to a sequence of two square wave signals generated by the two switch-type Hall sensors.
[0019] Specifically, when the window lift motor 10 is a three-phase brushless direct current motor, the rotor position sensing unit 40 includes three switch-type Hall sensors. The three switch-type Hall sensors detect the position of the motor rotor relative to the stator winding of each of three phases. Therefore, positions of two adjacent switch-type Hall sensors have a 120-degree electric angle difference therebetween. the motor actual rotating direction can be judged according to a sequence of the square wave signals generated by any two or all of the three switch-type Hall sensors. When the window lift motor 10 is a single phase brushless direct current motor, the rotation direction judgment unit 27 is not included, and the rotor position sensing unit 40 needs only one switch-type Hall sensor. Of course, as noted above, when the rotation direction judgment unit 27 is included, two switch-type Hall sensors are needed, one of which is used to operate the motor, and both of which are used in combination to judge the motor rotating direction.
[0020] The inverter 30 is a bridge switch circuit. Referring to FIG. 3 , when the three-phase brushless direct current motor is used, the bridge switch circuit is typically a three-phase bridge switch circuit having six power transistor switches. Referring to FIG. 4 , when the single-phase brushless direct current motor is used, the bridge switch circuit is typically an H-bridge switch circuit having four transistor switches. The power transistor switches may be metal-oxide-semiconductor field-effect transistors (MOSFETs).
[0021] The anti-pinch module 50 includes a pulse counter 51 , a count comparator 53 , an obstacle judgment unit 55 , and an anti-pinch instruct unit 57 . Since the rotor position sensing unit 40 includes one or more switch-type Hall sensors, the rotor position sensing unit 40 generates square wave pulse signals as the motor rotor rotates. The number of the pulses is directly proportional to rotation turns of the rotor. The transmission module has a fixed reduction ratio. Therefore, the number of the pulses linearly corresponds to a position of the vehicle window, and the position of the vehicle window can be determined by recording the number of the pulses. In one embodiment, the window lift motor 10 is a three-phase brushless direct current motor, the rotor position sensing unit 40 includes three switch-type Hall sensors, and the pulse counter 51 are used to record the number of the pulses generated by the three switch-type Hall sensors during lifting up of the vehicle window 80 . In another embodiment, the vehicle window 80 is a single-phase brushless direct current motor, the rotor position sensing unit 40 includes two switch-type Hall sensors, and the pulse counter 51 is used to record the number of the pulses generated by one of the two switch-type Hall sensors during lifting up of the vehicle window 80 . The count comparator 53 is used to compare the number of the pulses recorded in the pulse counter 51 against a predetermined threshold, and determine whether or not the vehicle window is in an anti-pinch area according to a relationship between the recorded number of the pulses and the threshold. For example, the threshold includes a threshold upper limit and threshold lower limit. When the recorded number of the pulses falls between the threshold upper limit and the threshold lower limit, it is determined that the vehicle in window is in the anti-pinch area, such that the obstacle judgment unit 55 is initiated.
[0022] The obstacle judgment unit 55 can determine whether the lifting vehicle window meets an obstacle by measuring at least one of a motor speed, a current of the motor windings and a motor output torque and comparing the measured parameter against a preset threshold. A width of the pulses generated by the rotor position sensing unit 40 has a positive correlation with the rotation speed of the window lift motor 10 and can therefore be used to indicate the motor speed. In one embodiment, the obstacle judgment unit 55 includes a pulse width recorder and a pulse width comparator. The pulse width recorder is used to record the width of the pulses generated by the rotor position sensing unit 40 . The pulse width comparator is used to compare the recorded pulse width against a preset threshold. When the recorded pulse width is greater than the preset threshold, the obstacle judgment unit 55 determines that there is an obstacle. When the vehicle window 10 is a three-phase brushless direct current motor, the rotor position sensing unit 40 includes three switch-type Hall sensors, and the pulse width recorder is used to record the width of the pulses generated by one of the switch-type Hall sensors. When the vehicle window 10 is a single-phase brushless direct current motor, the rotor position sensing unit 40 includes two switch-type Hall sensors, the pulse width recorder is used to record the width of the pulses generated by one of the switch-type Hall sensors.
[0023] The anti-pinch instruction unit 57 is connected to the motor drive/control module 20 . When the obstacle judgment unit 55 judges that there is an obstacle, the anti-pinch instruction unit 57 generates an anti-pinch instruction, and the data processing unit 23 of the motor drive/control module 20 performs data processing according to the anti-pinch instruction to obtain a corresponding anti-pinch control signal. The driving unit 25 of the motor drive/control module 20 generates an anti-pinch driving signal according to the anti-pinch control signal and drives the inverter 30 to perform the anti-pinch operation, making the window lift motor 10 rotate reversely.
[0024] Referring to FIG. 5 , a vehicle window lift control method according to one embodiment of the present invention includes the following steps.
[0025] S 10 : a brushless direct current motor is provided to drive the vehicle window to lift up or lower down.
[0026] A rotary shaft of the brushless direct current motor is connected to the vehicle window through a transmission mechanism. The window lift motor is connected to the vehicle window through a transmission assembly including a gearbox, traction cables and the like, such that power outputted from the rotary shaft of the window lift motor is transmitted to the vehicle window to form a traction force to drive the vehicle window to lift up or lower down. An external power supply supplies power to the brushless direct current motor through an inverter.
[0027] S 20 : the brushless direct current motor is started in a desired direction or stopped according to an external command. The step S 20 includes the following steps:
[0028] S 21 : a data processing is perfoiiiied according to an external command to obtain a corresponding motor control instruction. The external command includes an instruction of lifting up, lowering down or stopping the vehicle window that is inputted through a vehicle window button.
[0029] S 22 : Inverter is driven according to the motor control instruction to supply or cut off power to various windings of the brushless direct current motor, thereby starting the motor in a desired direction or stopping the motor.
[0030] S 30 : Rotor position is detected with a rotor sensing unit, a motor actual rotating direction is determined according to a sequence of the position feedback signals, and the actual rotating direction is compared against a rotating direction controlled by the control signal. If the two rotating directions are inconsistent, a failure signal is generated.
[0031] S 40 : The inverter is driven to ensure continuous running of the motor according to rotor positon feedback signals.
[0032] S 50 : it is deteiiiiined whether or not the vehicle window is in an anti-pinch area.
[0033] The step S 50 includes the following steps:
[0034] S 51 : the number of the position feedback signals is recorded. In one embodiment, recording the number of the position feedback signals is performed using a counter to record the number of the square wave pulses.
[0035] S 52 : the recorded number of the position feedback signals is compared against a preset threshold, and whether or not the vehicle window is in the anti-pinch area is determined according to the relationship between the number of the position feedback signals and the preset threshold. In one embodiment, the preset threshold has a threshold upper limit and a threshold lower limit. When the number of the feedback signals falls between the threshold upper limit and the threshold lower limit, it is determined that the vehicle window is in the anti-pinch area.
[0036] S 60 : it is determined whether or not the lifting vehicle window meets an obstacle when it is determined that the vehicle window is in the anti-pinch area.
[0037] The step S 60 includes the following steps.
[0038] S 61 : an operational parameter of the brushless direct current motor is detected. The parameter includes any one or more of a motor rotating speed, a current of the motor windings, and a motor output torque. When the feedback signals generated by the rotor position sensing unit are square wave pulse signals, a pulse width of the pulse signals can be used to indicate the motor rotating speed. In one embodiment, this step records the width of the pulses generated by the position sensing unit.
[0039] S 62 : the detected operational parameter of the brushless direct current motor is compared against a preset threshold, and whether or not the lifting vehicle window meets an obstacle is determined according to the relationship between the detected operational parameter of the brushless direct current motor and its corresponding threshold. In one embodiment, the recorded width of the pulses generated by the position sensing unit is compared against a threshold of the pulse width. It is determined that there is an obstacle when the recorded width of the pulses generated by the position sensing unit is greater than the threshold.
[0040] S 70 : when it is determined that there is an obstacle, the motor is controlled to perform an anti-pinch operation.
[0041] The step S 50 comprises the following steps:
[0042] S 51 : when it is determined that there is an obstacle, an anti-pinch instruction is generated.
[0043] S 52 : a corresponding anti-pinch control signal is obtained by data processing according to the anti-pinch instruction.
[0044] S 53 : according to the anti-pinch control signal, a driving signal is generated which is used to drive the inverter to perform the anti-pinch operation. The anti-pinch operation includes making the brushless direct current motor rotate reversely.
[0045] Although the invention is described with reference to one or more embodiments, the above description of the embodiments is used only to enable people skilled in the art to practice or use the invention. It should be appreciated by those skilled in the art that various modifications are possible without departing from the spirit or scope of the present invention. The embodiments illustrated herein should not be interpreted as limits to the present invention, and the scope of the invention is to be determined by reference to the claims that follow.
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A vehicle window lift control system includes a window lift motor, a motor drive/control module, an inverter, a rotor position sensing unit, and an anti-pinch module. The window lift motor is a brushless direct current motor. The anti-pinch module detennines whether or not the vehicle window is in an anti-pinch area based on position feedback signals generated by a rotor position sensing unit that is inherently included in the brushless direct current motor. When the vehicle window is in the anti-pinch area, an obstacle judgment unit is initiated. When there is an obstacle, an anti-pinch instruction unit sends an anti-pinch instruction to the motor drive/control module, and the motor drive/control module drives the inverter according to the anti-pinch instruction to make the motor rotate reversely. The present vehicle window lift control system has the advantages of small size, low failure rate and low cost.
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BACKGROUND
As shown in FIG. 1 , a nuclear power station conventionally includes a reactor pressure vessel 10 with various configurations of fuel and reactor internals for producing nuclear power. For example, vessel 10 may include a core shroud 30 surrounding a nuclear fuel core 35 that houses fuel structures, such as fuel assemblies, 40 . A top guide 45 and a fuel support 70 may support each fuel assembly 40 . An annular downcomer region 25 may be formed between core shroud 30 and vessel 10 , through which fluid coolant and moderator flows into the core lower plenum 55 . For example, in US Light Water Reactor types, the fluid may be purified water, while in natural uranium type reactors, the fluid may be purified heavy water. In gas-cooled reactors, the fluid coolant may be a gas such as helium, with moderation provided by other structures. The fluid may flow upward from core lower plenum 55 through core 35 . In a water-based reactor, a mixture of water and steam exits nuclear fuel core 35 and enters core upper plenum 60 under shroud head 65 . One or more control rod drives 1 may be positioned below vessel 10 and connect to control rod blades or other control elements that extend among fuel assemblies 40 within core 35 .
Nuclear reactors are refueled periodically with new fuel to support power operations throughout an operating cycle. During shutdown for refueling, the vessel 10 is cooled, depressurized, and opened by removing upper head 95 at flange 90 . With access to the reactor internals, some of fuel bundle assemblies 40 are replaced and/or moved within core 35 , and maintenance on other internal structures and external structures like control rod drive (CRD) 1 may be performed from outside of reactor 10 .
As shown in FIG. 2 , CRD 1 may be mounted vertically within a CRD housing welded to a stub tube 8 , which may extend up into reactor pressure vessel 10 . A spud 46 at a top of index tube 26 may engage and lock into a socket at the bottom of the control element, and index tube 26 may vertically move through action of the CRD hydraulic system to vertically drive or hold the control element. CRD 1 and any control rod element connected via spud 46 form an integral unit that is manually uncoupled by before CRD 1 or control element may be removed from reactor 10 . Below vessel 10 , in an access area or drywell, CRD flange 6 may extend downward from vessel 10 and the CRD housing. CRD 1 may be secured to a face by mounting bolts 88 in flange 6 . A pressure-tight seal can be created by O-ring gaskets (not shown) between flange 6 and any mounting surface.
One or more CRD hydraulic system lines 81 may pass through ports in flange 6 and work with a CRD hydraulic system for CRD operation, inserting, holding, and/or withdrawing a control element (not shown) via spud 46 at desired positions and speeds for reactor operation. For example, CRD flange 6 may include a withdraw port 82 and an insert port 83 with a check valve 20 . Lines 81 may carry water to insert port 83 and from withdraw port 82 . Withdraw port 82 may serve as an inlet port for water during control rod withdrawal, via vertical downward movement of spud 46 . A piston port 69 may connect to withdraw port 82 in CRD flange 6 . Through piston port 69 , water and hydraulic pressure may be applied through an under-the-collet-piston annulus to collet piston 29 to cause withdrawal, or downward vertical movement of spud 46 . For normal or scram insertion, via vertical upward movement of spud 46 , water may be supplied to inlet port 82 , and withdrawal port 82 may work as an outlet port for water. For rapid shutdown, such as scram insertion with rapid upward movement of spud 46 , check valve 20 may direct external hydraulic pressure or reactor pressure to an underside of drive piston 24 .
FIG. 3 is a detail view of a bottom of flange 6 , showing an area for insertion of probe 12 a . As shown in FIG. 3 , piston tube 15 extends upward through the length of CRD 1 , terminating in a watertight cap near the upper end of the tube section and, oppositely, at a threaded end secured by a fixed piston tube nut 16 at the lower end of CRD 1 . A position indicator probe 12 a may be slid into piston tube 15 from the bottom, potentially sealed into indicator tube within the same. External to piston tube 15 , probe 12 a can be welded to a plate 12 b bolted to housing 12 extending from a bottom of flange 6 . Housing 12 may be secured to CRD ring flange 17 , a downward extension of flange 6 , by housing screws 13 . In turn, ring flange 17 may be secured to flange 6 by flange screws 9 . Probe 12 a and housing 12 attached about fixed piston tube nut 16 as a unit, removable from a bottom of flange 6 together through removal of housing screws 13 .
Probe 12 a transmits electrical signals to provide remote indications of control rod position and CRD operating temperature. Probe 12 a can include a switch support with reed switches and a thermocouple for transmitting electrical signals to provide remote indications of control rod position and CRD operating temperature. The reed switches are normally open but may be closed individually during CRD operation by a ring magnet in the bottom of drive piston 24 ( FIG. 2 ). The reed switches are connected by electrical wires to a connection port 14 that may extend outside of housing 12 and provide wired connectivity to remote operators. Housing 12 may protect any electrical wires extending into connection port 14 .
In order to uncouple a control element from CRD 1 , a lock plug in spud 46 ( FIG. 2 ) may be raised from below by operators working below reactor vessel 10 . Conventionally, position indicator probe 12 a is removed from CRD 1 prior to drive removal to allow access to piston tube 15 by an uncoupling tool. Operators typically manually attach an uncoupling tool is to a bottom of CRD 1 and apply force, such as with a jack, to raise piston tube 15 . When the control element is in its “full-out” position directly atop stub tube 8 , drive piston 24 may be separated from a piston head by a small distance. Operators typically observe this positioning directly under vessel 10 , and when the positioning is reached, give an indication for removal by other operators. Raising piston tube 15 by this distance lifts the lock plug out of spud 46 , allowing spud and piston together to be withdrawn and disengage from a control element.
SUMMARY
Example embodiments include systems that attach to control rod drives and selectively bias the same through a joining structure and a driving jack. The joining structures may fit about an outside of the control rod drive and secure a portion of the jack with the stationary control rod drive exterior. A displacement platform of the jack may then be fitted against a moveable control rod drive structure, like a piston tube that can be displaced in a control element decoupling action. For example, a joining structure may include clamping surfaces that fit about a flange of a control rod drive to secure the jack against the piston tube. The jack can then drive the piston tube with several pounds of force relative to the control rod drive against which the jack expands or contacts. This driving can be achieved via a local force that requires no human interaction. Further, attaching and removing the driving jack to a control rod drive may require no tools, little force, and very little time. This permits control rod drive decoupling actions and procedures to be undertaken with minimal expense and effort, including minimal radiation exposure in areas typically having higher doses directly under a reactor. A probe or other instrumentation, as well as local power connections or supplies and receivers/transmitters allow remote operators to control and monitor the action of example embodiments, progress of any decoupling procedure, and/or malfunctions in control rod drive structures.
BRIEF DESCRIPTIONS OF THE DRAWINGS
Example embodiments will become more apparent by describing, in detail, the attached drawings, wherein like elements are represented by like reference numerals, which are given by way of illustration only and thus do not limit the terms which they depict.
FIG. 1 is an illustration of a related art nuclear power vessel and internals.
FIG. 2 is an illustration of a related art control rod drive.
FIG. 3 is a detail illustration of a related art control rod drive.
FIG. 4 is an illustration of an example embodiment remote decoupling system.
FIG. 5 is an illustration of an example embodiment attachment subsystem.
FIG. 6 is an illustration of an example embodiment piston tube probe.
FIG. 7 is an illustration of an example embodiment drive subsystem.
FIGS. 8A and 8B are detailed illustrations of an example embodiment slide lock for a probe to a drive subsystem.
FIGS. 9A and 9B are detailed illustrations of an example embodiment slide lock for an attachment subsystem to a drive subsystem.
FIGS. 10A and 10B are illustrations of example embodiment motors useable in drive subsystems.
DETAILED DESCRIPTION
This is a patent document, and general broad rules of construction should be applied when reading and understanding it. Everything described and shown in this document is an example of subject matter falling within the scope of the appended claims. Any specific structural and functional details disclosed herein are merely for purposes of describing how to make and use example embodiments or methods. Several different embodiments not specifically disclosed herein fall within the claim scope; as such, the claims may be embodied in many alternate forms and should not be construed as limited to only example embodiments set forth herein.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that when an element is referred to as being “connected,” “coupled,” “mated,” “attached,” or “fixed” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between”, “adjacent” versus “directly adjacent”, etc.). Similarly, a term such as “communicatively connected” includes all variations of information exchange routes between two devices, including intermediary devices, networks, etc., connected wirelessly or not.
As used herein, the singular forms “a”, “an” and “the” are intended to include both the singular and plural forms, unless the language explicitly indicates otherwise with words like “only,” “single,” and/or “one.” It will be further understood that the terms “comprises”, “comprising,”, “includes” and/or “including”, when used herein, specify the presence of stated features, steps, operations, elements, ideas, and/or components, but do not themselves preclude the presence or addition of one or more other features, steps, operations, elements, components, ideas, and/or groups thereof.
It should also be noted that the structures and operations discussed below may occur out of the order described and/or noted in the figures. For example, two operations and/or figures shown in succession may in fact be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Similarly, individual operations within example methods described below may be executed repetitively, individually or sequentially, so as to provide looping or other series of operations aside from the single operations described below. It should be presumed that any embodiment having features and functionality described below, in any workable combination, falls within the scope of example embodiments.
Applicants have recognized problems in uncoupling tools and procedures. For example, uncoupling tools typically require manual action for long periods of time directly under reactor vessels. Operators must manually jack up each piston tube and measure/hold them in uncoupling positions while control elements are replaced. Further, uncoupling tools typically include a magnet-actuatable switch that reacts to a ring magnet in a drive piston, giving indication (e.g., a single LED illumination) when a piston tube is raised to a sufficient uncoupling distance. Operators typically have to directly observe this indication and manually react with raising/lowering the tube with a jack and other specialized tools to maintain the same. To overcome these newly-recognized problems as well as others, the inventors have developed easily-installed systems and methods for reliable, remote control rod drive (CRD) actuation and monitoring that may reduce operator burden and radiation exposure.
The present invention is systems, methods, and subsystems using remotely-operable drives to move reactor components through expansion or retraction of the drives. In contrast to the present invention, the few example embodiments and example methods discussed below illustrate just a subset of the variety of different configurations that can be used as and/or in connection with the present invention.
FIG. 4 is an illustration of an example embodiment remote decoupling system 100 in use with a CRD 1 , such as an existing drive in a nuclear power reactor 10 shown and described in FIGS. 1-3 . As shown in FIG. 4 , example embodiment system 100 may include several subsystems operable together to connect to a lower flange 6 of a CRD 1 , typically under reactor 10 . For example, system 100 may include an example embodiment attachment subsystem 300 , an example embodiment drive subsystem 400 , and/or an example embodiment probe 212 . While example embodiment subsystems 300 and 400 and probe 212 are useable to attach to and decouple CRD 1 , it is understood that other subsystems are useable in example embodiments.
Attachment subsystem 300 removably secures to CRD 1 via lower flange 6 , permitting force to be remotely and selectively directed to CRD tube 15 . FIG. 5 is a detail illustration of an example attachment subsystem 300 as it may be installed about a CRD 1 . As shown in FIG. 5 , attachment subsystem 300 includes at least one clamp arm 310 and a flange sleeve 320 . Clamp arm 310 may extend in an axial direction a length sufficient to span a distance from drive subsystem 400 ( FIG. 4 ) to above a lower flange 6 of CRD 1 , in order to securely join the two. As seen in FIG. 5 , clamp arm 310 may include a U-shaped end, hook, or other clamping structure that can join around flange 6 and/or bias against a back surface of flange 6 .
Flange sleeve 320 may be shaped to sit around or over a lower axial end of CRD flange 6 , near where bolts 88 and/or screws 9 / 13 connect terminal pieces to CRD 1 . Any terminal housing structures and/or fixed piston tube nut 16 ( FIG. 3 ) may be removed from CRD 1 prior to installation of attachment subsystem 300 , such as during an outage or at plant fabrication or decommissioning, to expose piston tube 15 . Flange sleeve 320 may include a receptacle 325 for storing fixed piston tube nut 16 during installation and use of example embodiments, to prevent misplacement and allow easy accounting for and reassembly with fixed piston tube nut 16 . Flange sleeve 320 may also sit below flange 6 , about shoot-out steel, probe 212 , or another structure that connects to flange 6 to achieve the same securing as a direct sleeve-flange connection.
With CRD lower flange 6 and piston tube 15 free and accessible, flange sleeve 320 may be seated against lower flange 6 in a vertical or axial direction securely except potentially to permit rotation about a vertical axis for proper aligning. Flange sleeve 320 may include a number of sleeve wings 321 for each clamp arm 310 . Clamp arm 310 may be joined to flange sleeve 320 at a hinge 311 on sleeve wing 321 or other connection point that permits movement for removable installation and securing. For example, hinge 311 on sleeve wing 321 may permit clamp arm 311 to rotate about a single axis relative to flange sleeve 320 . If sleeve wing 321 is relatively narrow, flange sleeve 320 and clamp arm 310 joined thereto may be rotated together about a length axis of CRD 1 between bolts 88 for desired positioning while avoiding the same.
As shown in FIG. 5 , clamp arm 310 may initially be collapsed inward at a free lower end/outward at a clamping end during installation such that clamp arm 310 and flange sleeve 320 seat completely onto and over lower flange 6 of CRD 1 and rotated into position about the same without blocking by clamp arm 310 . Then clamp arm 310 may be expanded so as to rotate and seat a U-shaped or clamping end against a back of flange 6 , as shown by the terminal inward arrow in FIG. 5 .
Clamp arm 310 may include a selective lock that secures attachment subsystem 300 to CRD 1 following installation. For example, as shown in FIG. 5 , a rotatable locking edge 312 may be positioned on a telescoping or extendable end of clamp arm 310 . Locking edge 312 may include a variable diameter that is shaped at some portions to seat into a locking notch 322 in a corresponding guide ear 321 . In this way, after one or more clamp arms 310 are extended over and rotated to seat against flange 6 to secure subsystem 300 , locking edges 312 may be extended vertically to locking notches 322 and rotated (in a vertical axis perpendicular to that of hinge 311 ) into locking notches 322 . For example, locking edges 312 may have a varying diameter that allows edges 312 to be moved with arm 310 vertically (long, straight double arrow in FIG. 5 ) to locking notches 322 without being blocked by guide ear 321 when arm 310 is rotated outward and secured to flange 6 . The varying diameter may then be rotated (rotational double arrow in FIG. 5 ) at notch 322 to engage notch 322 and prevent any further movement of arm 310 except rotation in the vertical axis to “unlock” the edge 312 from notch 322 . The resulting installation is shown in FIG. 3 , with arms 310 substantially vertical and parallel with CRD 1 .
The movements and interrelation of parts of example embodiment attachment subsystem 300 may allow easy and quick installation of attachment subsystem 300 to flange 6 of CRD 1 without any vertical slippage. Subsystem 300 of FIG. 3 may also be easily removed through rotation, then extension, then rotation of clamp arms. This easy and reliable installation and removal may permit minimal personnel effort and work-time about CRD 1 to install and use example embodiments. As such, example embodiments may reduce radiation exposure and increase productivity in control rod operations and maintenance.
Although example embodiment attachment subsystem 300 is shown with two clamp arms 310 that reach around flange 6 to vertically secure to the CRD 1 , it is understood that any number of clamp arms 310 and/or other attachment devices, including magnets, adhesives, cables, screw clamps, hydraulics, etc. may be used to attach various systems and subsystems in example embodiments to CRD 1 .
FIG. 6 is an illustration of an example embodiment probe 212 useable in example embodiment system 200 . Example embodiment probe 212 is sized and shaped to fit within piston tube 15 ( FIG. 4 ). As shown in FIG. 4 , example embodiment probe 212 may be inserted into piston tube 15 before or after installation of attachment subsystem 300 when nut 16 is removed and stored in receptacle 325 or piston tube 15 is otherwise accessible. Probe 212 may include threads or other securing structures that permit a removable joining with piston tube 15 , such that a position of probe 212 accurately reflects a vertical displacement of piston tube 15 in CRD 1 during decoupling. Further, any securing structure between probe 212 and piston tube 15 may be sufficiently robust to transfer thousands of pounds of forces in upward and downward vertical directions to piston tube 15 without slippage or breaking in the even probe 212 is the only direct connection to piston tube 15 .
As shown in FIG. 6 , example embodiment probe may include a stem 213 with electronics, such as Hall effect sensors, magnetostrictive sensors, or magnetic members, that can detect a position of stem 213 and probe 212 in piston tube 15 . For example, stem 213 may be lined with sensors that detect ring magnets within a piston or piston tube 15 of a conventional CRD 1 ( FIG. 2 ). Based on magnetic field strength at various vertical positions, probe 212 may determine a degree of insertion and/or extension of piston tube 15 , similar to a determination made in conventional CRD decoupling.
Electronics in stem 213 may connect to a probe port 215 in a spring-biased base 214 that extends out of piston tube 15 in example embodiment probe 212 . For example, one or more pins or other known communicative interfaces in probe port 215 may transmit signals to other components for proper decoupling measurement. Spring-biased base 241 may connect to other mechanical or communications systems to ensure that example embodiment probe 212 remains seated in piston tube 15 to accurately measure vertical movement of the same decoupling.
As shown in FIG. 4 , with probe 212 and attachment subsystem 300 in place and secured to lower flange 6 of CRD 1 , example embodiment drive subsystem 400 may be installed to probe 212 and attachment subsystem 300 in order to provide remote communications and movement of piston tube 15 for decoupling.
FIG. 7 is a detailed illustration of drive subsystem 400 . As shown in FIG. 7 , drive subsystem 400 may include a base 450 , connection arm 410 , and jack platform 415 . Each connection arm 410 may match location of a terminal of installed clamp arm 310 from example embodiment attachment subsystem 300 , and jack platform 415 may match a location of example embodiment probe 212 and/or piston tube 15 in a CRD. In this way, example embodiment drive subsystem may be useable with other example embodiments. Of course, other dimensioning and configuration of example embodiments is possible to successfully interact with a control rod drive.
Each connection arm 410 may receive or otherwise attach to a terminal end of clamp arm 310 in order to join example embodiment subsystems 300 and 400 and transfer force to piston tube 15 . For example, connection arm 410 may define a receptacle 412 into which a corresponding clamp arm 310 ( FIG. 5 ) fits. A locking structure, such as slide lock 411 may permit securing a lower end of clamp arm 310 in receptacle 412 .
Similarly, jack platform 415 may receive or otherwise attach to a probe 212 , such as via spring-biased face 214 of probe 212 ( FIG. 6 ). For example, jack platform may define a receptacle 417 into which a corresponding probe 212 ( FIG. 6 ) fits. A locking structure, such as slide lock 416 may permit securing a lower end of probe 212 in receptacle 417 . Jack platform 415 may also directly attach to piston tube 15 or indirectly attach to piston tube 15 through probe 212 ; similar connection structures are useable between such elements.
FIGS. 8-9 are details of receptacles 412 and 417 showing examples of simple locking structures in action. As seen in FIGS. 8A and 8B , slide lock 416 may be easily movable in a depth dimension in jack platform 415 . Slide lock 416 may define a variable-shaped gap where it intersects receptacle 417 , such that an edge of slide lock 416 extends into receptacle 417 when fully seated into jack platform 415 . When withdrawn in the depth direction, the variable-shaped edge of slide lock 416 may not extend into receptacle 417 . When paired with a notch in probe 212 , slide lock 416 may thus secure probe and jack platform 415 together, transferring force between the two and/or piston tube 15 , to which probe 212 and/or jack platform 415 may be secured. As shown in FIGS. 8A-B , jack platform 415 may further include a communications interface 418 that receives information from probe 212 and/or provides power and information to probe 212 . For example, communications interface 418 may be pin receptacles that uniquely fit pins in probe port 215 on a face of example embodiment probe 212 .
As seen in FIGS. 9A and 9B , slide lock 411 may be easily movable in a depth dimension in connection arm 410 . Slide lock 411 may define a variable-shaped gap where it intersects receptacle 412 , such that an edge of slide lock 411 extends into receptacle 412 when fully seated into connection arm 410 . When withdrawn in the depth direction, the variable-shaped edge of slide lock 411 may not extend into receptacle 412 . When paired with a notch in clamp arm 310 ( FIG. 5 ), slide lock 411 may thus secure attachment subsystem 300 and connection arm 410 together, ensuring example embodiments and CRD 1 remain in relatively static positions, with the exception of any relative movement of jack platform 415 , probe 212 , and piston tube 15 .
Example embodiment subsystems 300 and 400 , as shown in FIGS. 5 and 8-9 , may take advantage of relatively simple connection structures that reliably and statically interconnect CRD 1 and example embodiment system 100 , while permitting relative movement of jack platform 415 and piston tube 15 . These simple connection structures may require no separate tooling; for example, all connection structures in FIGS. 5 and 8-9 may be directly installed and manually operated through pushing, pulling, or twisting the connectors to lock them into place by hand. This relatively simple installation may permit relatively quick and unencumbered installation and securing of example embodiment system 200 with no additional tools required, speeding work time and easing work burden about CRD 1 , which may be a higher radiation area.
Returning to FIG. 7 , base 450 may include a face with interactive structures for communications and manual interaction. As shown in FIG. 7 , a communications and/or power port 451 may allow connection to a wire, pinned interface, or other connector for information transmission from example embodiments during decoupling. For example, port 451 may be interfaced with probe 212 via communications interface 418 and probe port 215 , and data and/or operation instructions to/from probe 212 may be transacted through port 451 . Port 451 may further receive instructions or operations signals from a remote user for translation into decoupling actions to be taken, including raising or lowering jack platform 415 . Port 451 may further accept external power connections to power various parts of example embodiment system 200 . Or port 451 may be internal or missing entirely, and communications and operation may be provided through wireless communication over WiFi or other electromagnetic communication. In such an example, base 450 may include a local power source such as a battery to drive operations without external power sources.
Base 450 may further include operations indicators 452 that show a status of example embodiment system 200 . For example, operations indicators 452 may include LED lights reflecting power status, initialization routines, successful data connection, errors, etc. A power button 453 may provide manual, local activation capabilities, and an initialization button 454 may provide internal testing and initialization to confirm proper connection with other systems and/or piston tube 15 . Of course, indicators 452 , and power/initialization button 452 / 454 may be absent, and such functionality may be provided remotely through wireless communications with a receiver in base 450 or via a cable connected to port 451 , for example.
Through relatively simple setup, example embodiment system 200 may be fabricated by installing attachment subsystem 300 , inserting probe 212 (if any), and connecting them to drive subsystem 400 through relatively simple and reliable joining mechanisms. Base 450 may then be connected to remote operations and/or operated locally. Removal, such as following decoupling, may be achieved by reversing these actions in example embodiment system 200 . As such, total assembly and disassembly may be relatively simple and consume minimal time, and personnel may vacate the area of CRD 1 during the actual uncoupling procedure, which may be achieve through remote operation of example embodiment system 200 discussed below. Although various types of physical and communicative connections and securing structures, as well as different subcomponents have been discussed and interrelated in the above example embodiments, it is understood that other joining mechanisms, communications devices and protocols, and securing structures may be used in example embodiments while still allowing remote decoupling action and monitoring of the same.
In order to perform a decoupling operation on typical CRDs 1 , piston tube 15 must be raised by an inch or more using upwards of approximately 1000 pound of force. As such, jack platform 415 raises and lowers vertically relative to base 450 in order to similarly move piston tube 15 to which it may be rigidly joined in the vertical/axial direction. Jack platform 415 may exert large amounts of force through proper gearing and/or induction driving structures in base 450 , for example, over the required distance. Such raising and lowering may be performed in the absence of any local personnel action through remote operation of example embodiment system 200 .
FIGS. 10A and 10B are illustrations of an example embodiment motorized drive in base 450 to provide for raising jack platform 415 ( FIG. 4 ) under sufficient force and distances. As shown in FIG. 10A , a motor 465 may be mounted inside base 450 . Motor 465 may be an electric motor powered by a local battery or external power source. Motor 465 may have sufficient wattage or torque, or be connected through sufficient gearing, to create over 1000 pounds of force in jack platform 415 in an upward and downward vertical direction. For example, motor 465 may connect to a worm gear 460 that converts force from motor 465 to controlled vertical movement in a geared piston in jack platform 415 without slippage or reversal/overshoot under action of motor 465 . Motor 465 may be actuated remotely, such as through wireless or electrical signal from a user positioned in a control room or offsite, allowing jacking of piston tube 15 remotely.
Motor 465 may be selectively engaged, such as via an engagement assembly 466 that moves motor 465 in a depth direction to engage or disengage with worm gear 460 . For example, by driving a screw in engagement assembly 466 , a user or automatic function may disengage or engage motor 465 as desired. As shown in FIG. 10B , disengagement of motor 465 by turning a screw in assembly 466 to disconnect gearings of motor 465 and worm gear 460 may allow a user to manually operate work gear 460 in the instance of motor failure or necessary manual intervention. Motor 465 may further include a cycle counter or other sensor that relates its position, torque, and/or velocity to location, force, and/or speed of jack platform 415 . Such data may also be communicated to remote users through communications ports or interfaces in example embodiments, such that users may remotely monitor jack platform position, potentially independent of any piston tube sensor magnetic readings, in order to monitor progress and confirm or calibrate other sensors.
As seen in FIG. 4 , through connection of various subsystems among example embodiments, a relatively large amount of force may be selectively applied to piston tube 15 in CRD 1 in an upward or downward vertical direction. This force may be controlled by operators stationed remotely, allowing movement of piston tube 15 for decoupling without direct human action or monitoring, thus reducing human radiation exposure and workload. Further, operations of example embodiments, including system status/malfunction, exact location of probe 212 and thus piston tube 15 in CRD 1 , height and movement direction of jack platform 415 , etc. may be transmitted to remote operators to better inform their actions and other decoupling activities, such as in-core control element movements and removal from any unlocked spud.
Although a selectively-engaged motor 465 may be useable to provide the remotely-actuated force in example embodiments to achieve conscious uncoupling through relative movement, it is understood that any number of different force-creating devices can be used in example embodiments. For example, pneumatic cylinders or direct induction drives can be used to create desired vertical movement of platform 415 remotely.
Example embodiments and methods thus being described, it will be appreciated by one skilled in the art that example embodiments may be varied and substituted through routine experimentation while still falling within the scope of the following claims. For example, a variety of control rod drive designs are compatible with example embodiments and methods simply through proper dimensioning of example embodiments—and fall within the scope of the claims. Such variations are not to be regarded as departure from the scope of these claims.
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Systems join with a control rod drive and expand or contract to displace elements necessary for decoupling. Joining structures affix to on sides of the control rod drive allow discriminatory jacking by a powered drive also in contact with the control rod drive. A moveable piston tube can be displaced by this jacking with hundreds or thousands of pounds of force with respect to the control rod drive. Probes and other instrumentation and sensors are useable in the systems to accurately measure any of piston tube displacement, temperature, malfunction; drive power status, displacement or speed; and communications status. Manual interaction with the systems are not required during the jacking, and installation and removal of the systems requires no tools or great amount of time or effort. Through remote operation and brief installation, human exposure to radiation about control rod drives is minimized.
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CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application relates to U.S. non-provisional patent applications titled, “Supplemental Sensory Input/Output for Accessibility” and “Peripheral Device,” both of which were filed contemporaneously herewith.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] None.
REFERENCE TO SEQUENTIAL LISTING, ETC
[0003] None.
BACKGROUND
[0004] 1. Field of the Invention
[0005] The present invention relates generally to printers and multi-function peripheral (MFP) devices, and more particularly to access to networked peripheral devices for users.
[0006] 2. Background
[0007] Many of today's networked printers, networked MFP devices and other networked information technology (IT) devices support “walk-up” user-initiated functions such as confidential print, copy, facsimile, and so forth. A user interface (UI) typically enables a selection of a function and related attributes to be entered for the selected function.
[0008] These devices often employ a touch screen UI, which requires a user to be able to visually see and discern information presented on the UI to select a function and/or select attributes associated with the selected function. This can restrict a disabled or impaired user's ability to use the device.
[0009] In 1998, Congress amended the Rehabilitation Act to require Federal agencies to make their electronic and information technology accessible to people with disabilities. Inaccessible technology interferes with an individual's ability to obtain and use information quickly and easily. Section 508 was enacted to eliminate barriers in information technology, to make available new opportunities for people with disabilities, and to encourage development of technologies that will help achieve these goals. The law applies to all Federal agencies when they develop, procure, maintain, or use electronic and information technology. Under Section 508 (29 U.S.C. § 794d), agencies must give disabled employees and members of the public access to information that is comparable to the access available to others.
SUMMARY OF THE INVENTION
[0010] The present invention provides methods and apparatuses, including computer programs, for accessing networked peripheral devices.
[0011] In general, in one aspect, the present invention features a method for a user to control a peripheral device, including receiving an input from the user at a workstation adapted to the user, determining whether the received input is valid, generating a job ticket from the valid input, sending the job ticket to the peripheral device, and receiving an identifier representing the job ticket from the peripheral device. The method may also include signaling the user in response to the determining whether the received input is valid. The method may also include receiving a completion indication from the user.
[0012] In embodiments, the input can include one or more alphanumeric characters representing one or more peripheral device functions and associated attributes, parameters or instructions.
[0013] Determining can include checking or verifying that the received input represents valid peripheral device functions or associated attributes, parameters or instructions.
[0014] Signaling can include a first audio sound signifying the received input is valid, and a second audio sound signifying the received input is invalid. Signaling can also include a first visual indication signifying valid input was received and a second visual indication signifying invalid input was received.
[0015] The job ticket can include a request for the peripheral device to perform a function. The job ticket can also include one or more attributes, parameters or instructions associated with such function.
[0016] In another aspect, the present invention features a method to control a networked peripheral device including receiving an input from a user at an input/output (I/O) device adapted for the user, determining whether the received input is valid, sending the valid input to the networked peripheral device, and receiving, from the networked peripheral device, an identifier representing the valid input. The method may also include signaling the user in response to the determining whether the received input is valid. The method may also include receiving a completion indication from the user.
[0017] In embodiments, the input can include one or more alphanumeric characters representing one or more peripheral device functions and associated attributes, parameters or instructions.
[0018] Determining can include checking or verifying that the received represents valid peripheral device functions or associated attributes, parameters or instructions.
[0019] Signaling can include a first audio sound signifying valid received input, and a second audio sound signifying invalid received input. Signaling can also include a first visual indication signifying valid received input, and a second visual indication signifying invalid received input.
[0020] The valid input can include a request for the peripheral device to perform a function. The valid input can also include one or more attributes, parameters or instructions associated with such function.
[0021] In another aspect, the present invention features a method of executing a job ticket in an MFP device including assigning an identifier to a job ticket received over a network from a user, storing the job ticket by the identifier, receiving input at the MFP device, and executing the job ticket associated with the identifier if the input received matches the identifier. The method may also include signaling negative feedback if the input received fails to match the identifier and signaling positive feedback if the input received matches the identifier.
[0022] In embodiments, signaling can include a first audio sound signifying the negative feedback and a second audio sound signifying the positive feedback.
[0023] The job ticket can include a request for the MFP device to perform a function. The job ticket may also include one or more attributes, parameters or instructions associated with the function.
[0024] The present invention can be implemented to realize one or more of the following advantages.
[0025] Methods enable a user to retrieve a predefined job ticket (i.e., a request for a device to perform a function including a selection of one or more associated attributes, parameters or instructions) created by the user at the user's adaptive workstation. The user can submit the job ticket for the device to process independent of the user's ability to discern visual information presented on a standard UI. The methods may also result in the user having to spend less time at the device.
[0026] One implementation of the present invention provides all of the above advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above-mentioned and other features and advantages of the present invention, and the manner of attaining them, will become more apparent, and the present invention will be better understood by reference to the following description of embodiments of the present invention in conjunction with the accompanying drawings, wherein:
[0028] FIG. 1 is a block diagram of an exemplary system.
[0029] FIG. 2 is a block diagram of an exemplary multifunction peripheral (MFP) device.
[0030] FIG. 3 is a block diagram of an exemplary operation panel adapted to the MFP of FIG. 2 .
[0031] FIG. 4 is a flow diagram of an exemplary process to create a job ticket in accordance with the present invention.
[0032] FIG. 5 is a flow diagram of an exemplary process to generate an identifier in accordance with the present invention.
[0033] FIG. 6 is a flow diagram of an exemplary process to execute a job ticket in accordance with the present invention.
[0034] Like reference numbers and designations in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0035] It is to be understood that the present invention is not limited in its application to the details of construction or the arrangement of components set forth in the following description or illustrated in the drawings. The present invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use herein of “including,” “comprising,” or “having” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted,” and variations thereof are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical connections or couplings.
[0036] In addition, it should be understood that embodiments of the present invention may include both hardware and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic based aspects of the present invention may be implemented in software. As such, it should be noted that a plurality of hardware and software-based devices, as well as a plurality of different structural components may be utilized to implement the present invention. Furthermore, as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify embodiments of the present invention, and other alternative mechanical configurations are possible.
[0037] As shown in FIG. 1 , an exemplary system 100 includes a user's workstation 110 connected to an all-in-one, mopier or multifunction peripheral (MFP) device 120 via a network 130 . The user's workstation 110 is adapted to a user with a disability, such as a disability in seeing, hearing, performing manual tasks or working and may include a processor 140 , memory 150 and input/output (I/O) device 160 . I/O device 160 is one of assistive technology adapted for use by the user and can include an interactive voice response system, large viewing screen, a screen reader, touch screen, keyboard, mouse, voice recognition system, digital ink pen, track pad, track ball and/or sound generating device. As such, I/O device 160 enables input discernable by sight (e.g., color, size, graphics), touch (e.g., size, shape, location), and/or sound (e.g., tone generation). Given that that workstation 110 and I/O device 160 has been selected and configured specifically for a user with a specific disability, this working environment is generally referred to as being such user's “comfort zone.”
[0038] Network 130 may be any suitable communication network or system, such as the Internet, the telephone system, wireless networks, satellite networks or cable TV networks. Network 130 may also be one or more networks, and various private and public networks could be used in various combinations to provide the communication links desired or needed to create embodiments or implementations of the present invention, as would be apparent to one of ordinary skill in the art. Thus, the present invention is not limited to any specific network or combinations of networks.
[0039] MFP device 120 is an office machine that is capable of performing multiple functions, such as printing, copying, faxing, scanning, and e-mailing or any combination thereof. Components of MFP device 120 can include a printer or printing unit; scanner, scanning unit or scanning system; copier; facsimile; media card readers units; and/or hard disk. MFP device 120 can work both as a computer peripheral (using a computer port, like ethernet/Wi-Fi-LAN, USB, or FireWire) and as a stand-alone device (i.e., with no need for a computer connection) to perform functions such as copying, e-mailing or faxing.
[0040] As shown in FIG. 2 , MFP device 120 can include a scanner, scanning unit or scanning system 210 and an image signal processor 220 . MFP device 120 can also include a printer or printing unit 230 having a printing processor 240 , an optical system 250 , and an image forming system 260 . MFP device 120 may also include a memory 270 , a document transport unit 280 , and an operation (e.g., input/output) panel 290 . Operation panel 290 is attached to the MFP device 120 for initiating walk-up operations or functions, such as copying, faxing, scanning, or e-mailing, and for displaying device options or conditions, such as duplex copying or stapling. In an alternate embodiment, operation panel 290 may be integrated or housed within MFP device 120 .
[0041] Scanning system 210 reads a document and converts the obtained data into image data. Memory 270 transmits image data and color data, if applicable, to printing unit 230 either directly, or through a memory installed therein. The image data and color data may also be transmitted to a users workstation or computer for further processing or storage. The image data and color data may also be transmitted to a desired destination by facsimile or electronic mail.
[0042] As shown in FIG. 3 , operation panel 290 can include, for example, a signaling device 310 , such as a sound generating or audio signaling device (e.g., beeper, tone generator, audio speaker, and so forth) and a display screen or touch panel 320 for indicating a warning, such as jamming, a service man call, and paper empty, or other information, attributes or conditions such as a threshold level, magnification ratio, and copy sheet size. Operation panel 290 may also include a keypad or key group 330 for entering input such as the desired number of copies and magnification ratio; a clear key 340 for clearing input entered at keypad 330 ; a panel reset key 350 for clearing all of the set conditions; a stop key 360 for stopping or halting operation of MFP device 120 and a start key 370 for starting or commencing the current or desired operation.
[0043] Signaling device 310 provides additional assistance for users with disabilities. For example, as shown FIG. 3 , signaling device 310 is an audio signal device for assisting a vision-impaired user who may not be able to discern visual indications on the touch panel 320 .
[0044] The exemplary description below details operation panel 290 and I/O device 160 for a vision-impaired user. However, as will be appreciated by one of ordinary skill in the art, other systems may be designed or implemented for other types of disabilities.
[0045] Referring back to FIG. 1 , in one example, using workstation 110 and/or I/O device 160 , which may be specifically configured to assist a user with a disability, the user can setup, pre-program, emulate or request a walk-up operation or function, such as copying, faxing, scanning, or e-mailing, from the user's workstation instead of at MFP device 120 . This request is accomplished by creating a job ticket or work order and depositing or storing that job ticket in networked MFP device 120 , as illustrated by process 400 in FIG. 4 .
[0046] At block 402 , I/O device 160 receives input corresponding to the desired walk-up operation or function from the user. Such input may be a request to setup the desired function or an attribute, instruction or parameter associated with the function to be performed. For example, if the desired operation is to make a copy, associated attributes may include input sides, output sides, number of pages per copy, and number of copies. For facsimile functions, the associated attributes may be the destination fax number, input sides and delayed send option. For electronic mail, the associated attributes and parameters may include the destination e-mail address and input sides.
[0047] Input may be entered in any format recognizable by MFP device 120 . For example, input may be one or more alphanumeric characters entered through a keyboard or touchscreen; selections made by clicking on desired attributes, instructions or parameters with a mouse or other input device; or verbal responses recorded as a list of desired attributes, instructions or parameters are read to the user.
[0048] Validation of the input occurs at block 404 . Validation includes verifying the input received is valid. For example, validation may help ensure that the function requested is recognized by MFP device 120 or that the attributes, parameters or instructions inputted can be associated with the selected function. Validation may further include checking to make sure that required parameters have been set.
[0049] Once validation 404 has been performed, feedback may be provided to the user through I/O device 160 at workstation 110 (block 406 , 408 ). Positive feedback, which indicates that progress is being made towards the successful creation of a job ticket, may be signaled for valid inputs (block 406 ), and negative feedback may be signaled for invalid inputs (block 408 ). After the user receives the feedback, positive or negative, the user may re-input the invalid function request, attribute, instruction or parameter or continue inputting or selecting additional function requests attributes instructions or parameters. The input, validation and feedback processes may be repeated until all desired attributes, instructions or parameters have been defined or an indication that the setup operation is complete, such as an end of input indicator or job creation indicator, a perform function signal, or a job submission indicator, is received (block 412 ). It will be appreciated by one of ordinary skill in the art that validation of job ticket may also occur after a predetermined number of inputs or after an indication is received rather than after each individual input.
[0050] At block 418 , the job ticket or work order, based upon the input received from the user at workstation 110 using I/O device 160 is generated or created. The data format of job ticket may be any format recognizable by MFP device 120 , such as XML format or HTML format. The job ticket is then sent to MFP device 120 via network 130 (block 420 ). At block 422 , a job identifier or ID associated with the job ticket is received from MFP device 120 via network 130 at workstation 110 . The job identifier can be any identifier capable of being presented at MFP device 120 , such as alphanumeric or numeric characters, hotkeys or functions keys.
[0051] The process 500 for creating a job identifier or ID is described in FIG. 5 . Once MFP device 120 receives the job ticket (block 502 ), it may check or verify that the received job ticket is of a valid form (block 503 ). For example, MFP device 120 can check to make sure there was no error in the job ticket transmission to MFP device 120 . MFP device 120 may also verify that MFP device 120 has the capability to perform the desired function, such as by querying the capabilities of MFP device 120 . Verification can further include verifying that required parameters of the desired function have been set. For example, for an electronic mail function, MFP device 120 may verify that the job ticket includes the destination e-mail address; and for a facsimile function, MFP device 120 may verify that the job ticket includes the destination facsimile number.
[0052] At block 506 , MFP device 120 stores the job ticket and assigns a job identifier or ID to the job ticket. The job identifier is then stored at MFP device 120 (block 508 ). At block 510 , the job identifier is also returned, communicated or sent via network 130 to workstation 110 and communicated to the user so that the user can proceed to MFP device 120 with the knowledge that the desired MFP function request, together with any associated instructions, attributes or parameters to facilitate such request, have been preloaded and are accessible via the job identifier.
[0053] One exemplary process 600 for executing the desired function request is illustrated in FIG. 6 . In this example, using the operation panel 290 at MFP device 120 , the user can locate and activate or press a preset or predetermined button or key, such as an idle key, to begin the job execution process. At block 602 , MFP device 120 may verify whether the device is ready to receive and perform requested functions. MFP device 120 may also provide the appropriate ready state feedback (block 604 ) to the user, such as through an audio signal or visual display on operation panel 290 . For example, if MFP device 120 is not in a ready state, it may provide negative feedback, such as. a “razz” sound, to indicate that a request cannot be honored, possibly due to, for example, MFP device 120 being in an intervention required state (e.g., out of paper or network down) and that further input is futile. If MFP device 120 is in a ready state, it may provide positive feedback, such as a “ding” sound to indicate that requests can be honored and that MFP device 120 is ready for the user to select or input a function.
[0054] Once the user is notified that the MFP device 120 is ready, the user can enter the job identifier at MFP device 120 (block 608 ). MFP device 120 verifies that a valid job identifier is received (block 610 ). If a valid job identifier was received, MFP device 120 may automatically and immediately execute the job associated with the job identifier (block 614 ). MFP device 120 may also wait until it receives an indication from the user, such as by another key or button press, that the user is ready for the job to be performed before actually executing the job.
[0055] If the job ID received by MFP device 120 is not recognized or is invalid, MFP device 120 may provide negative feedback, such a through an audio signal or visual display on the operation panel 290 of MFP device 120 (block 612 ), so that the user is notified that the expected job cannot be completed.
[0056] Embodiments of the present invention can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of thereof. Embodiments of the present invention can be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine readable storage device or in a propagated signal, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.
[0057] The exemplary embodiments of the present invention can be performed by one or more programmable processors executing a computer program to perform functions of the present invention by operating on input data and generating output. The exemplary embodiments can also be performed by, and apparatus of the present invention can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).
[0058] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in special purpose logic circuitry.
[0059] The foregoing description of several methods and an embodiment of the present invention have been presented for purposes of illustration. It is not intended to be exhaustive or to limit the present invention to the precise steps and/or forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is intended that the scope of the present invention be defined by the claims appended hereto.
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A method for controlling a peripheral device includes receiving input from a user at a workstation adapted to the user, determining whether the received input can be valid, generating a job ticket from the valid input, sending the job ticket to the peripheral device and receiving an identifier representing the job ticket from the peripheral device.
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BACKGROUND OF THE INVENTION
A tampon is defined by Webster's New 20th Century Dictionary as a plug of cotton or other absorbent material placed into a wound, cavity, etc. for the control of hemorrhage or the absorption of secretions. The word has become almost exclusively the name of a form of the product used by women during menstruation.
The effort by the industry supplying tampons has been to create more and more absorbency in order to necessitate fewer changes by the user. There has been very little departure from the original cylindrical cotton body except in the mechanical art of insertion and in the absorbency of the body itself.
SUMMARY OF THE INVENTION
This product satisfies the requirements of a completely effective tampon including complete absorption of menstrual fluid. These criteria are met in such a way that the anatomical and physiological environment of the vaginal tract are not adversely disturbed. For example, the interfaces between the tampon and the mucosa are designed to be compatible and non-ulcerating. The common problem of channeling of the menstrual fluid around the tampon is avoided by design and not by pressure packing. Partial emptying of the tampon of its potentially toxic contents is prevented by a unique pursing closure system which is activated upon tampon removal. Only recently has new information been obtained on the role of catamenial products in the pathogenisis of potentially serious diseases such as Toxic Shock Syndrome, and therefore, it is an object of this invention to produce a product that will offer both high performance and safety.
The tampon is a substantially tubular body of absorbent material which, upon being inserted into the vagina will flower to an open funnel position and cap the cervix whereby essentially all of the menstrual fluid is captured and directed into an inward channel of the tampon.
It is also an object of the invention to produce a container effect of the tampon by preventing moisture absorbency through the lower portion of the tampon from an area which produces no menstrual blood. A conventional tampon will extract moisture from the vagina and cause excess drying and possible adverse results to the vaginal tissue.
This product satisfies the requirements of a completely effective tampon, including complete absorption of menstrual fluid. These criteria are met in such a way that the anatomical and physiological environment of the vaginal tract are not adversely disturbed.
Set forth below is a set of Anatomical an Physiological Considerations and Problems in separately numbered paragraphs. The means of satisfying the conditions and meeting the problems according to this invention are set forth as lettered paragraphs following each numbered paragraph.
1. All menstrual fluids flow from the uterus down into the vagina through an opening in the cervix (cerival os).
A. The tampon, upon insertion into the vagina, will flower open to an open funnel position and cap the cervix capturing the menstrual fluid which is directed into an inner chamber of the tampon.
2. The fluid products of menstruation are intended to pass rapidly through the vagina and be excreted. Freshly released menstrual fluid is only mildly toxic, but stagnant fluid both decomposes rapidly to form toxic substances and also supports microbial growth which produces toxins, which are causative factors for diseases such as the Toxic Shock Syndrome.
B. The menstrual fluid is trapped within the highly absorbent inner chamber of the tampon and is no longer able to have contact with the vaginal tissue, i.e. the fluid is essentially removed from the body upon being released by the cervix.
3. The vaginal glands release their own fluids which coat the vaginal tissues and are intended to protect the vaginal tissues from the menstrual fluids. Currently marketed high absorbency tampons remove this protective layer of vaginal fluids along with the menstrual fluids. This indiscriminate removal and subsequent drying and ulceration has been implicated strongly by medical scientists at the Center for Disease Control (CDC) as an important mechanism in the development of the Toxic Shock Syndrome.
C. This tampon is designed to absorb only the menstrual fluids as they are released from the cervix by means of a highly absorbent funnel system around the cervical os. The protective vaginal secretions are not absorbed by this tampon. This selective absorbency is achieved by having a non-absorbent outer covering over the lower exterior of the tampon which corresponds to the anatomical area which has the protective secretions. The non-absorbent outer layer of the tampon and the secretion covered vaginal tissue provide a compatible, non-ulcerating interface which protects the body from any noxious substance.
4. Channeling of menstrual fluids around tampons has been a problem. It occurs because the vagina (birth canal) has many folds which provide channels (thus the term channeling) for the menstrual fluid to flow around the ordinary tampon, thus resulting in tampon failure.
D. This tampon avoids channeling by its funneling design. All of the menstrual fluid is trapped by the absorbent funnel and directed into the inner retaining chamber. This is in contrast to currently marketed products which solve the problem by having the tampon expand upon wetting, producing a pressure pack to prevent the channeling.
5. The anatomical configuration of the vaginal tract is such that the inner cavity is larger than the narrowed exterior opening. The consequence of this is that currently marketed tampons, which are designed to expand in an unrestricted fashion in order to eliminate channeling, must be squeezed during removal. The squeezing action causes "stagnant menstrual fluid" (see number 2) to be released into the inner vaginal cavity and possibly retained where toxic substances can be absorbed through ulcerated areas of the vaginal wall, possibly producing serious illnesses or death.
E. This tampon is a complete collector of menstrual fluid without requiring expansion. It is in fact restricted in its expansion by its tubular, nonabsorbent exterior surface. Therefore, upon removal it is not squeezed like other tampons. An additional safety feature of this tampon is its unique pursing closure system which is activated upon the tampon's removal. The closure system prevents stagnant menstrual fluid from escaping during removal.
DETAILED DESCRIPTIONS OF THE DRAWINGS
FIG. 1 is an exterior view of a commercial embodiment of the tampon as supplied to the user.
FIG. 2 is a top end view of the tampon with the drawstring illustrated diagramatically in that it is unencased in the hemmed edge of the forward peripheral edge.
FIG. 3 is a vertical section in smaller size than the FIG. 2, illustrating the pursed condition of the forward end either before use or after extraction.
FIG. 3A is an enlarged detail of one section of the forward end of FIG. 3 illustrating the hemmed encasement of the drawstring for pursing and the membrane encasement for opening restriction.
FIG. 4 is a top view, enlarged, of the flowered open end of the tampon.
FIG. 5 illustrates a beginning step in the insertion wherein the membrane has caused the flowered opening.
FIG. 6 illustrates the rupture of the restricting membrane as the tampon is further driven out of its carrier.
DETAILED DESCRIPTION
FIG. 1 illustrates the exterior view of a tampon 10 as it appears in an insertion cylinder 12 and having an insertion plunger 14. This external view is not significantly different in appearance than other conventional tampons available.
The shelf form of the tampon device of FIG. 1 is illustrated in vertical section in the FIG. 3. Absorbency is provided by a body 16 of superabsorbent material of conventional nature. Body 16 is preferably substantially tubular with an open central area 17. It is preferable to have a completely open area 32, although an elongated cylindrical member with a gradually decreased density of absorbent material to the center may be employed with the advantages of this invention.
In the shelf form of FIG. 3, a forward end 18 projects from the forward end of the insertion cylinder 12. The forward end 18 has an annular perimeter wall 20 operable between a funnel-open configuration as shown in FIGS. 5 and 6, and a pursed condition as shown in FIG. 3 wherein the annular wall 20 is drawn onto the central axis of the tubular body.
One of the principal objects of the invention is to flair the forward end 18 open to a funnel configuration, substantially as shown in FIGS. 5 and 6. This opening is sometimes referred to as a flowering open which refers to the opening from a bud to a mature flower condition.
To accomplish the flaring open of the forward end 18, the preferred embodiment employs an encasing membrane 22 which is secured to the area of the perimeter wall 20 and extends around to the forward end of the insertion cylinder 12 where it is secured in a fused area 23. A heat seal thermoplastic membrane is preferred, but a tie device of another material may otherwise be secured by adhesives. The membrane 22 is therefore very similar to a protective annulus over the end 18, but is employed for another purpose which supersedes any encapsulating function. That function is to cause the end 18 to flare.
Flaring of the end is achieved by moving the tampon out of the carrier in a forward direction by driving force of the plunger 14. As the tampon is thus ejected from its carrier, the membrane 22 will exert a restricting force to the perimeter wall 20 because of the limited length of the membrane. Thus, the perimeter wall 20 will begin to unfold and eventually reach the extreme condition shown in FIG. 5 wherein the membrane is stretched to its limit and the end 18 has fully flared to the open condition.
The membrane 22 is preferably formed with a tear strip 24 which is simply a weakened area or preferably a perforated area which will allow further drive of the tampon to exert a force on the membrane greater than the strength of the tear strip. Thus, severing of the membrane will take place as illustrated in the FIG. 6. Thereafter, the body of the tampon may be ejected from the insertion cylinder 12 and the forward end 18 of the tampon will be a funnel configuration that will move forward and essentially cap the cervix of the user and thereby enhance the directing of menstrual fluid into the tampon as opposed to seeping down around the exterior as in conventional practice.
Although a membrane 22 is the preferred form of the tie means restricting the end 18 to cause opening, a series of separate strips or strings has been found to be an acceptable alternative. These tie means, whichever form selected, is a means for spreading the forward end of the body to an open funnel configuration. The importance of the tie means is that it be of limited length and connect the insertion tube outer wall to the forward annular wall of the tampon body for limiting the outward movement of the body annular wall as the body is ejected from the insertion tube, whereby the annular wall is caused to flare to the open funnel configuration. It is also necessary to then have a means for severance of the tie means upon full opening of the forward end to the funnel configuration. This is done by preferably perforating a line around a membrane but does have alternative possibilities in weakened lines and tie devices.
After the tampon has been saturated, and the central area 17 filled with as much fluid as practical, a separate means is provided for drawing the forward end perimeter of the body in an inward and downward direction toward the center of the body, whereby the body forward end is closed to entrap menstrual fluid within the interior of the absorbent body.
The separate means for drawing the forward end inwardly is a drawstring in this preferred embodiment. The area of the perimeter wall 20 is preferably hemmed to form a channel 26 but could be separate belt loops or similar devices for forming a pursing action when a drawstring 28 is placed in the channel and drawn to shorten the string within the channel.
In FIG. 2, the drawstring is shown as it appears in the original package and after having been activated to draw the end closed. FIG. 4 illustrates the open funnel configuration. Both FIGS. 2 and 4 are somewhat schematic in that the hemmed channel is cut away to reveal the position of the drawstring 28 which would be obscured by showing the string encased within the confines of the channel.
Openings 30 on opposite sides of the perimeter wall 20 admit the drawstring into separate channel areas and the string is attached at opposite sides of the perimeter wall at points 29.
The drawstring is knotted by a knot 31 to cooperate with a support disk 33 at the base end of the cylinder 12 as illustrated best in FIG. 3. When the knot 31 is engaged in the central opening of disk 31, it can no longer be activated to draw the string beyond that limit, and thereafter will exert a uniform pull on the entire tampon. Thus, after the tampon is inserted and the insertion cylinder and plunger removed, the string 28 will serve as a combined closure means and withdrawal means to first pull the drawstring and purse the forward end of the tampon and thereafter, when the knot 31 strikes the support disk 33, the tampon will be removed from the vagina of the user.
This closing action is important in that any fluid absorbed to overcapacity in the funnel forward portion of the tampon is caused to flow downwardly and into the center area of the tampon rather than to flow out of the tampon into the vaginal channel.
In order to assure the capturing of the menstrual fluid and simultaneously prevent the overdrying and absorption of natural mucosa from the vagina channel, a moisture barrier 34 encapsulates the exterior of the tampon body from the area of the perimeter wall 20 to the bottom end of the tampon. Thus, as the pursing closing action takes place, the moisture barrier wall will cause the menstrual fluid to move downwardly into the central area of the tampon and prevent the loss of the fluid into the vaginal tract. Also, prior to that function, that barrier wall forms an exceedingly necessary and novel function in this improved tampon not heretofore available.
There has been much publicity about Toxic Shock Syndrome caused possibly by overabsorbency and subsequent ulceration caused by modern super absorbent materials used in tampons. In a publication Annals of Internal Medicine, a report in a conference held Nov. 20-22, 1982, sponsored by the Institute of Medicine and National Academy of Sciences, Volume 96, June 1982, reported on the pathological findings in twelve fatal cases of Toxic Shock Syndrome. That report said that there are notable pathological changes occuring in the vagina, cervix, lungs, liver, and kidney. And the report goes on to state that of these, the most striking pathological changes were noted in the vaginal, cervical mucosa. Extensive desquamation of the ulceration were seen in six of six patients where adequate vaginal/cervical sections were available.
The report is in detail and vital to the understanding of the overabsorbent relationship to the Toxic Shock Syndrome and concludes by stating that the findings of the study--normal endometrium without evidence of bacterial invasion associated with severely ulcerated cervical/vaginal mucosa showing evidence of superficial gram-positive bacterial invasion--suggests that access to the systemic circulation may be gained through cervical/vaginal blood or lymph vessels exposed by desquamation or ulceration. They state in this report that the vaginal tampon may be important in these processes. Excessive absorption of blood and of protective secretions may lead to mucosal drying and increased susceptibility so to superficial abrasion with both tampon insertion and withdrawal.
Although the report is very carefully worded not to directly attribute Toxic Shock Syndrome to tampon use and/or over absorption, it has been found that the barrier wall 34, provided for the containment of fluid, has performed the extremely important second function of prevention of vaginal wall drying. This structure will thereby fully eliminate any superabsorbency contribution to vaginal problems.
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A catamenial device which is a tampon having a hollow or loosely packed central area and a forward end which flares open to a funnel configuration upon insertion into the vaginal tract of the user to cap the cervix and thereby direct menstrual fluid into the interior thereof. The tampon is removed by pulling a drawstring which is also a pursing string. The string first closes the forward end before exerting removal force on the tampon. Also, the body of the tampon is encased in a fluid barrier so that fluid is captured and retained within the tampon and absorption by the tampon from the vaginal wall is prevented.
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TECHNICAL HELD
The invention relates to thrust reversers for turbofan gas turbine engines.
BACKGROUND
Thrust reversers on gas turbine engines have to fulfill two functions: while stowed, to provide an exhaust nozzle for the direct thrust generated by the engine; and while deployed, to redirect the engine thrust to order to provide a decelerating force after landing. Since almost the entire flight sequence occurs with the thrust reverser in the stowed position, it is desirable that the presence of the thrust reverser does not degrade the direct thrust performance of the engine.
While many thrust reversers models have been used successfully for a number of years, there is a need to provide an improved arrangement.
SUMMARY
In one aspect, the present concept provides a thrust reverser for a turbofan engine, the thrust reverser comprising at least first and second doors pivotally connected to a jet pipe, the jet pipe having an exit defined by an exit profile, each door having an outer skin and an inner skin mounted to the outer skin, the inner skin extending along only a portion of an axial length of the outer skin, the inner skin of the doors having edges that matingly engage the edges of the jet pipe substantially along the length of the exit profile.
In another aspect, the present concept provides a thrust reverser comprising: a jet pipe having an inner flow surface for receiving engine exhaust gases, the jet pipe having a circular portion and two arms extending rearward of the circular portion; and a pair of opposed doors pivotally connected to the jet pipe arms, each door having an inner flow surface in registry with the inner flow surface of the jet pipe and mating therewith to engage the jet pipe along its exit length when the doors are closed, wherein the inner surface of the jet pipe and the inner surfaces of the doors co-operate to provide a nozzle for engine exhaust gases.
In another aspect, the present concept provides a thrust reverser for a turbofan engine, the thrust reverser comprising an interior wall defining a continuous nozzle interior surface from a nozzle inlet to a thrust reverser exit when the doors are in a stowed position, the nozzle interior surface co-operatively defined by an internal surface of a jet pipe of the thrust reverser, internal surfaces of a plurality of closed thrust reverser doors of the thrust reverser, and seals extending between the jet pipe and each door substantially along an interface between the jet pipe and said door.
Further details of these and other aspects of the improvements presented herein will be apparent from the detailed description and appended figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a side view of an example of a nacelle provided with a thrust reverser according to the present arrangement, its doors being shown in a stowed position;
FIG. 2 is a schematic side view of the thrust reverser of FIG. 1 , with doors shown in a deployed position;
FIG. 3 is a rear view of what is shown in FIG. 2 ;
FIG. 4 is a schematic longitudinal cross-sectional view showing an example of the improved arrangement with the thrust reverser doors in the stowed position;
FIG. 5 is a view similar to FIG. 4 , showing the doors in a deployed position;
FIG. 6 is an isometric view showing an example of an improved upper door;
FIG. 7 is an isometric view showing an example of an improved lower door;
FIG. 8 is a cross-section through lines 8 - 8 of FIG. 1 ;
FIG. 9A is an isometric view of the upper seal shown in FIG. 4 and FIG. 9B is an enlarged cross section of an example of the seal mounted to the jet pipe; and
FIG. 10 is a view similar to FIG. 4 , showing another embodiment of the improved arrangement.
DETAILED DESCRIPTION
Referring now to FIG. 1 , there is shown an example of a nacelle 20 including a thrust reverser 22 of the target/bucket type, located in the aft section 20 a of the nacelle 20 . The turbofan gas turbine engine is located within the nacelle 20 and the engine and nacelle 20 are attached under the wings, or to the fuselage, of the aircraft using an appropriate arrangement (not shown).
The thrust reverser 22 comprises two opposite pivoting doors 24 , 26 forming an exhaust exit nozzle of the nacelle 20 , having a planar exit 28 , when the doors are in their stowed position. One door 24 is at the upper side and the other door 26 is at the lower side.
Each door 24 , 26 has a trailing edge 24 a , 26 a defining a portion of the exit 28 . The arrows in FIG. 1 represent the direct thrust air flow generated by operation of the engine.
FIG. 2 is an enlarged view of only the thrust reverser of FIG. 1 , showing a jet pipe 30 to which doors 24 , 26 are pivotally connected.
FIG. 3 is a rear view of what is shown in FIG. 2 . The doors 24 , 26 are in their deployed position in FIGS. 2 and 3 . The jet pipe 30 is concealed inside the aft section 20 a of the nacelle 20 when the doors 24 , 26 are in their stowed position, as in FIG. 1 .
As shown in FIG. 4 , the jet pipe 30 has axially-downstream-extending arms 32 on either side of upper and lower cutouts 34 , with peripheral edges defining the cutouts 34 , each edge having substantially horizontal or longitudinal portion 38 and a generally vertical or circumferential portion 40 (which the reader will appreciate is semi-circular in shape, extending from the substantially horizontal portion 38 on one side or arm of the jet pipe 30 , to the substantially horizontal portion 38 on the other side or arm of the jet pipe 30 ). Peripheral edges preferably include a seal 52 along the lengths of portions 38 and 40 , as will be described further below.
The arrows in FIG. 2 indicate the main exhaust gas flow path during thrust reversal. Exhaust gases coming out of the engine are redirected substantially forwardly when the doors 24 , 26 are in their deployed position.
The gases exit the doors 24 , 26 in the vicinity of their leading edges 24 b , 26 b . The leading edges 24 b , 26 b are located at the front of the doors 24 , 26 , and hence are ?leading? edges with reference to the travel path of the aircraft.
The redirection of the gases coming out of the engine creates a horizontal retarding force opposing the forward movement of the aircraft. Increasing the output thrust generated by the engine increases the aerodynamic decelerating force.
In the illustrated example, the trailing edge 24 a of the upper door 24 is pivoted behind the trailing edge 26 a of the lower door 26 , this resulting from the asymmetrical positioning of the pivots with reference to the horizontal medial plane of the jet pipe 30 , as described in applicant's co-pending application Ser. No. 11/534,202, filed Sep. 21, 2006.
It should be noted that, although the doors 24 , 26 are described herein and shown in the figures as an upper reverser door 24 and a lower reverser door 26 movable in a vertical plane, the doors may instead be configured with any other suitable orientation, such as a left door and right door movable in a horizontal plane. Other suitable arrangements are possible, as well, within the teachings of the present concepts.
FIG. 4 schematically shows a longitudinal cross section of the thrust reverser of FIG. 1 , and shows an example of the thrust reverser with doors 24 , 26 in a stowed position, adjacent the jet pipe 30 , such as is the case during direct thrust generation through operation of the engine.
Each door 24 , 26 has an outer skin or wall 44 extending from the leading edge 24 b , 26 b to the trailing edge 24 a , 26 a thereof. An inwardly extending rib(s) 45 (only one is shown) is provided adjacent the leading edge 24 b , 26 b , for strength and stiffness, and similar ribs extend along the sides of the door (not shown).
On the interior side of outer skin 44 , each door 24 , 26 has an inner skin, configured to provide a flow deflector 50 as will be described further below, mounted to the aft portion of the outer skin or wall 44 . Each flow deflector 50 has an axial or longitudinal length that is preferably less than the length of the outer skin of wall 44 of the corresponding door 24 , 26 .
Each flow deflector 50 is defined by a leading edge 56 and lateral edges 58 (see FIGS. 6 and 7 ) that preferably matingly correspond to the shape of the cutouts 34 of the jet pipe 30 , as will be described further below, to provide a substantially continuous exit nozzle 60 when doors 24 , 26 are stowed, as shown in FIG. 4 .
Each flow deflector 50 is preferably shaped and configured to create a substantially uniform interior flow surface, sometimes referred to as an inner mold line (IML), for exit nozzle 60 when the doors 24 , 26 are in their stowed position. The nozzle 60 is preferably defined by surface 62 on the inside of jet pipe 30 and arm 32 , and surfaces 64 ( FIG. 6 ) provided by deflectors 50 .
In this case, where the jet pipe 30 and deflectors 50 have interior flow lines which provide a fully-convergent (e.g. such as frustoconical) nozzle 60 , the flow deflectors 50 preferably have an inner surface 54 shaped and configured to continue the interior flow lines of jet pipe 30 in a fully-convergent fashion.
That is, the flow deflectors 50 complete the interior flow lines otherwise interrupted by the cutout portions 34 of the jet pipe 30 , and thus the surfaces 64 of the flow deflectors 50 create a substantially continuous and uninterrupted surface with the interior surface 62 of the jet pipe 30 .
As can be seen, in this example each flow deflector 50 extends forwardly from its trailing edge 24 a , 26 a to about the axial midpoint of its door 24 , 26 . This leaves the front or leading portion of each door 24 , 26 with a single layer skin or wall 44 , and results in a construction for the doors 24 , 26 which is lighter than a double skin construction.
The outer and inner skins may be sheet metal, cast, machined from solid, or made by other suitable technique. The inner skin/flow deflector 50 can be a single piece or multiple pieces joined together.
The deflectors 50 can be attached to skin 44 by rivets 70 (see FIGS. 6 and 7 ) or otherwise suitably fastened to the wall 44 of the doors 24 , 26 . Reinforcing radial frames(s) 80 (only one is shown per door in FIGS. 4 and 5 ) or other suitable structural reinforcement is preferably provided under flow deflectors 50 , if required or desired, for example to stiffen skin 44 or structurally support flow deflector 50 .
Referring to FIG. 8 , shown is a schematic lateral cross-section of the thrust reverser, taken generally along the lines 8 - 8 in FIG. 1 (door hinges, actuators, etc. are omitted, for clarity). As can be seen, a substantially continuous nozzle surface 62 is provided, through the co-operation of flow deflectors 50 and jet pipe 30 and arms 32 of jet pipe 30 .
In use, when the doors 24 , 26 are stowed, the flow deflectors 50 preferably matingly engage the jet pipe 30 substantially all along the peripheral edges. The edges are provided with a preferably continuous peripheral seal 52 preferably substantially along the entire length of the peripheral edges, i.e. along portions 38 and 40 . The peripheral seals 52 are preferably of the resilient type and are compressed substantially along their entire lengths when the doors are stowed.
In this example, the seal 52 is engaged and compressed by the leading edges 56 and lateral edges 58 of the flow deflectors 50 when the doors are stowed, to provide a complete sealing substantially around flow deflectors 50 , and thus impeding engine exhaust gases from leaking past the seals 52 during the direct thrust operation (i.e. doors stowed).
This has beneficial implications for powerplant efficiency because there are reduced aerodynamic losses within the nozzle 60 . To facilitate sealing in this example, leading edges 56 and lateral edges 58 are preferably smooth and contiguous, so that seal 52 is continuously sealingly engaged by the edges 56 , 58 , when the doors are stowed.
As described above, the peripheral seals 52 extend substantially along the longitudinal portion 38 , i.e. along the edges of the extending jet pipe arms 32 , and along the substantially circumferential portion 40 , along the edges of the jet pipe cutouts 34 . The seals 52 are the same length on the upper and lower sides of the jet pipe 30 when the jet pipe cutouts are symmetrical, as shown in FIGS. 4 and 5 .
Referring to FIG. 10 , showing another embodiment, lower cutout 34 b is larger than upper cutout 34 a , and with this arrangement, the seal 52 b is necessarily longer than seal 52 a , since the perimeter of cutout 34 b is longer than that of cutout 34 a , as the reader will appreciate. The asymmetrical cutout of the jet pipe shown in FIG. 10 is meant to provide substantially the same efflux exit effective area for the top and the lower reverser doors when said doors 24 , 26 are in their deployed position.
FIG. 5 shows the example thrust reverser of FIG. 3 with the doors 24 , 26 in a deployed position. As can be seen, gases flowing out through the jet pipe 30 are deflected by the doors 24 , 26 toward the front of the aircraft. It also shows that the front or leading edge 56 of the deflectors 50 is inclined to more smoothly blend to the inner surface of the skin/wall 44 . Other shapes, configuration and arrangements are possible for cutouts 34 and flow deflectors 50 . The reverse efflux preferably does not impinge the seals.
FIGS. 6 and 7 show isometric views of the example thrust reverser doors 24 , 26 of FIGS. 2 to 5 , each door being provided with a flow deflector 50 . FIG. 6 shows the upper door 24 and FIG. 7 shows the lower door 26 .
FIG. 9A shows an isometric view of the shape of upper seal 52 when installed on peripheral edge. As can be seen in this figure, and in FIGS. 6 and 7 , the shape of the seal 52 and peripheral edge, and the shape of deflector 50 , matingly engage along a three-dimensional interface defined between them. Longitudinal portion 38 has a slight curved portion 39 in the region of the door hinges, to facilitate sealing in this area.
FIG. 9B shows an example seal 52 , having a mounting portion 52 a suitably mounted (e.g. by bonding, riveting with the addition of a seal retainer (not shown) etc.) to jet pipe 30 , and a resilient sealing portion 52 b which is engaged and compressed by door 24 (in this case) when the door is closed (depicted by broken lines).
As can be appreciated, the arrangement described herein provides a way to seal the interface between doors 24 , 26 and jet pipe 30 , when the doors are in a stowed position, to eliminate cavities and provide a continuous aerodynamic nozzle surface for exhaust gases exiting the engine through the thrust reverser.
These cavities may otherwise generate turbulence or other aerodynamic losses, thus decrease the overall efficiency of the thrust reverser nozzle during the direct thrust operation of the engine.
Using substantially continuous peripheral seals, preferably along the entire length of edges 52 , between the jet pipe arms 32 , cutouts 34 and the doors 24 , 26 , is therefore an improvement to reverser efficiency when stowed.
As mentioned, the seal is preferably compressed all along its length, preferably at a substantial constant compression sufficient to provide effective sealing in view of the pressure drop across the sealed interface and temperature of the exhaust gases. The seal 52 may be provided in any material(s) and configuration(s) suitable to provide the sealing taught herein.
The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the spirit of the invention disclosed.
For instance, the shapes and the configuration of the doors may differ from what are shown and described. Although the reverser nozzle described is fully convergent when the reverser doors are stowed, the flow lines (IML) of the nozzle could be any suitable design, such as convergent-divergent, if desired.
The shape and the configuration of the deflectors may also differ from what is shown and described without departing from the concepts taught. Any surface(s) of the deflector may be used to engage the surface to be sealed.
It should be noted that the flow deflectors 50 of the two doors 24 , 26 do not need to be identical, as for example is shown in FIG. 10 . As mentioned, the present approach is not limited to a particular seal composition or configuration.
Still other modifications will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the scope of the appended claims.
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The thrust reverser includes, in one aspect, an interior flow deflector which defines a portion of a substantially continuous and uninterrupted nozzle interior surface with the interior of a jet pipe when the door is in a stowed position, thereby reducing aerodynamic losses and improving efficiency. In another aspect, improved sealing arrangement between the jet pipe and the door provides increased performance when the doors are stowed.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates in general to rock drill bits and, in particular, to an improved system, method, and apparatus for conformal bearings in rock drill bits.
[0003] 2. Description of the Related Art
[0004] Rolling cone earth boring bits have a bit body that typically has three bit legs which extend downward from the body. A bearing pin extends inward and downward from each bit leg. A conventional rock: bit bearing pin is cylindrical and rotatably receives a cone. There are several varieties of bearing systems used to support the cone. These bearing systems typically consist of a combination of radial and thrust bearings that may be either scaled and lubricated or unsealed and open to the drilling fluid. The contacting wear surfaces may consist of wear-resistant metals or non-metals such as tungsten carbide and/or diamond, and may engage through sliding and/or rolling. Open bearings may contain ports to force drilling fluid through the bearing system to lubricate and cool the wear surfaces.
[0005] The cones have teeth or compacts on their exteriors for disintegrating earth formations as the cones rotate on the bearing pins. A sealed, grease-lubricated bearing drill bit contains a lubricant reservoir in the bit body that supplies lubricant to the bearing pins. A seal prevents debris from contaminating the bearing and also blocks the lubricant from leaking to the exterior. When operated in a borehole filled with liquid, hydrostatic pressure acts on the drill bit as a result of the weight of the column of drilling fluid. Each bearing pin has a pressure compensation system that is mounted in the lubricant reservoirs in the bit body. A lubricant passage extends from the reservoir of the compensator to an exterior portion of the bearing pin. The pressure compensation system has a communication port that communicates with the hydrostatic pressure on the exterior to equalize the pressure on the exterior with lubricant pressure in the passages and clearances within the drill bit. The viscous lubricant creates hydrodynamic lift as the cone rotates on the bearing pin so that the load is partially supported by lubricant fluid film and partially by surface asperity to surface asperity contact.
[0006] A polycrystalline diamond compact (PDC) bearing is a type of open bearing system. The bearing pin and cone contain discreet PDC elements placed in a circumferential array on the radial bearing and in a planar array on the thrust bearing. The PDC elements on the cone slidingly engage the PDC elements on the bearing pin. Drilling fluid is driven through the bearing to cool and to lubricate the bearing. In this type of bearing system, load is supported almost entirely by surface asperity contact. Drill bits of this nature operate under extreme conditions. Very heavy weights are imposed on the drill bit to facilitate the cutting action, and friction causes the drill bit to generate heat. In addition, the temperatures in the well can be several hundred degrees Fahrenheit. Improvements in cutting structure have allowed drill bits to operate effectively for much longer periods of time than in the past. Engineers involved in rock bit design continually seek improvements to the bearings to avoid bearing failure before the cutting structure wears out.
[0007] In conventional bits ( FIG. 1 ), even though the clearance 111 between the cavity 113 of the cone 15 and the bearing pin 117 is quite small, the high load imposed on the drill bit causes the axis 119 of the cone 115 to translate eccentrically relative to the axis 121 of the bearing pin 117 . The clearance 111 is smaller on the lower side of the bearing pin 117 than the clearance 123 (e.g., 0.006 in) on the upper side of the bearing pin 117 . At high loads, the clearance 111 between the lower side of bearing pin 117 and cone 115 is reduced to zero and surface asperity to surface asperity contact occurs. The different radii of bearing pin 117 and cone 115 cause the surface asperity to surface asperity contact to be concentrated in a small area on the lower side of bearing pin 117 . The concentrated contact load creates large stress and temperature gradients that can lead to bearing failure.
[0008] There has been a variety of patented proposals to address this issue. For example, U.S. Pat. No. 4,403,812 discloses the use of an elastomeric suspension around the ball bearing race to take up bearing play. This compliant suspension allows the bearing elements to self-align. Other techniques have called for pre-wearing the bearings to increase surface contact area, and modifying the PDC element size and shape. Although each of these designs is workable, an improved solution that overcomes the limitations of the prior art would be desirable.
SUMMARY OF THE INVENTION
[0009] Embodiments of a system, method, and apparatus for rock drilling bit comprises improved radial bearings that maximize the contact area between the journal and cone bearings and, thus, maximizes load support. The radius of curvature of the journal and cone bearing are matched or conformed to greatly increase the apparent contact surface area on the pressure side of the bearing. The conformal radial bearing matches the journal and cone bearing radius on the bearing pressure side. This design reduces thermal fatigue cracks compared to conventional, completely cylindrical designs. The conformal journal surfaces may be formed on the main journal bearing, the pilot pin radial bearing, or both surfaces. In addition, diamond inlays or particles may be located on the bearing surfaces of the cone, the bearing pin, or both components.
[0010] The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the present invention, taken in conjunction with the appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] So that the manner in which the features and advantages of the present invention, which will become apparent, are attained and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof that are illustrated in the appended drawings which form a part of this specification. It is to be noted, however, that the drawings illustrate only some embodiments of the invention and therefore are not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
[0012] FIG. 1 is a sectional view of a conventional journal bearing for a rotating cone drill bit;
[0013] FIG. 2 is a quarter-sectional view of an earth boring drill bit constructed in accordance with the invention;
[0014] FIG. 3 is a sectional view of a bearing pin and cone on the drill bit of FIG. 2 taken along the line 3 - 3 of FIG. 2 , and is constructed in accordance with the invention;
[0015] FIG. 4 is a partial isometric view of an interior of a cone that is constructed in accordance with the invention;
[0016] FIG. 5 is a sectional end view of one embodiment of a bearing pin constructed in accordance with the invention;
[0017] FIG. 6 is a sectional side view of the bearing pin of FIG. 5 , taken along the line 6 - 6 of FIG. 5 , and is constructed in accordance with the invention; and
[0018] FIGS. 7-10 are schematic sectional views of some embodiments of drill bit bearing pins and cones constructed in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring to FIG. 2 , a bit 11 has a body 13 at an upper end that is threaded (not shown) for attachment to the lower end of a drill string. Body 13 has at least one bit leg 15 , typically three, which extend downward from it. Each bit leg 15 has a bearing pin 17 that extends downward and inward along an axis 16 . Bearing pin 17 has an outer end, referred to as last machined surface 19 , where it joins bit leg 15 . Bearing pin 17 has a main journal surface 18 and a nose 21 having a smaller diameter than surface 18 that is formed on its inner end. Nose 21 also has a pilot pin radial bearing surface 22 that is parallel to surface 18 relative to axis 16 .
[0020] A cone 23 rotatably mounts on bearing pin 17 . Cone 23 has a plurality of protruding teeth 25 or compacts (not shown). Cone 23 has a cavity 27 that is slightly larger in diameter than the outer diameters of bearing pin 17 . Cone 23 has a back face 29 that is located adjacent, but not touching, last machined surface 19 . If the bearing type is a sealed, lubricated bearing, a seal 31 is located in a seal cavity adjacent to the back face 29 . Seal 31 may be of a variety of types, and in this embodiment is shown to be as an o-ring. Seal 31 engages a gland or area of bearing pin 17 adjacent to last machined surface 19 . Other types of seals such as dual seals, seals with non-circular cross-sectional shapes, etc., also may be used.
[0021] Cone 23 may be retained in more than one manner. In the embodiment shown, cone 23 is retained on bearing pin 17 by a plurality of balls 33 that engage a mating annular recess formed in cone cavity 27 and on bearing pin 17 . Balls 33 lock cone 23 to bearing pin 17 and are inserted through a ball passage 35 during assembly after cone 23 is placed on bearing pin 17 . Ball passage 35 extends to the exterior of bit leg 15 and may be plugged as shown after balls 33 are installed.
[0022] A portion of cavity 27 slidingly engages journal surfaces 18 and 22 . In one embodiment, the outer end of journal surface 18 is considered to be at the junction with the gland area engaged by seal 31 , and the inner end of journal surface 18 is considered to be at the junction with the groove or race for balls 33 . Journal surfaces 18 and 22 serve as a journal bearing for loads imposed along the axis of bit 11 .
[0023] In sealed, lubricated bearings, a first lubricant port 37 is located on an exterior portion of journal surface 18 of bearing pin 17 . In one embodiment, first port 37 is located on the upper or unloaded side of journal surface 18 of bearing pin 17 between balls 33 and seal 31 . When viewed from nose 21 ( FIG. 2 ), the first port 37 is shown at zero degrees to vertical ( FIG. 3 ), which is top dead center. First port 37 could be on other areas of journal surface 18 , but may be located in the range from zero to 90 degrees. First port 37 is connected to a first passage 39 ( FIG. 2 ) via ball passage 35 . First passage 39 leads to a lubricant reservoir 41 that contains a lubricant.
[0024] Lubricant reservoir 41 may be of a variety of types. In one embodiment, an elastomeric diaphragm 43 separates lubricant in lubricant reservoir 41 from a communication port 45 that leads to the exterior of bit body 13 . Communication port 45 communicates the hydrostatic pressure on the exterior of bit 11 with pressure compensator 43 to reduce and preferably equalize the pressure differential between the lubricant and the hydrostatic pressure on the exterior.
[0025] The precise positioning between bearing pin 17 and cone 23 varies as the drill bit 11 is loaded during service, thereby creating eccentricity. The eccentricity is a result of the difference between the outer diameter of journal surfaces 18 and 22 and the inner diameter of cone cavity 27 . FIG. 3 shows the annular clearance 51 greatly exaggerated for illustration purposes. In actuality, annular clearance 51 is quite small, typically being no more than about 0.006 inches on a side. Annular clearance 51 may be the same as in the prior art bits of this type.
[0026] Under load, there is a difference between axis 16 ( FIG. 2 ) of bearing pin 17 and the axis of cone 23 . A particular bit 11 will have a maximum theoretical eccentric distance between the axes of the pin and cone based on a maximum load. In operation, there is an actual eccentric distance between the axes based on the actual load. The eccentricity ratio is the actual eccentric distance under a given load divided by the maximum eccentric distance possible. Under high loads, there is some elastic deformation of bearing pin 17 and cone 23 . The eccentricity ratio of bit 11 during operation may vary between about 0.9 to slightly greater than 1.0.
[0027] Even though annular clearance 51 is very small, it is required to allow assembly of cone 23 on bearing pin 17 and to allow for differences in thermal expansion during service. The annular space 51 has a largest width or clearance point 51 a at approximately 0° (i.e., top dead center). A minimum width or clearance span 51 b extends on both sides of a position at approximately 180° due to the downward force imposed on the bit during drilling.
[0028] Assuming cone 23 rotates clockwise in FIG. 3 , in one embodiment clearance 51 has a converging region 51 c from 0° to the region of minimum clearance at approximately 90° where the annular space for the lubricant gradually gets smaller. Clearance 51 has a diverging region 51 d , from approximately 270° to 0° where the annular space for the lubricant gets gradually larger. The minimum clearance span 51 b is effectively zero other than the lubricant film thickness between bearing pin 17 and cone 23 . During operation, at times the minimum clearance region 51 b may reach zero, but normally does not remain at zero. The converging region 51 c ends at minimum clearance span 51 b , and the diverging region 51 d begins at minimum clearance span 51 b.
[0029] In one embodiment, the invention comprises an earth boring bit 11 ( FIG. 2 ) having a bit body 13 with at least one depending leg 15 . A bearing pin 17 extends from the leg 15 and has journal surfaces 18 , 22 with shapes that are not perfectly circular designs with regard to their cross-sectional shapes (i.e., slightly rotationally asynmetrical about axis 16 , which may comprise the center axis of the bearing pin in some embodiments). A rotatable cone 23 has a cylindrical cavity 27 , 28 that fits slidingly on and directly engages the journal surface of the bearing pin. The journal surface comprises a main journal bearing surface 18 on a proximal end of the bearing pin 17 , and a pilot pin radial bearing surface 22 on a distal end of the bearing pin 17 . Both the main journal bearing surface 18 and the pilot pin radial bearing surface 22 may incorporate designs that are not perfectly or completely circular in cross-section (i.e., they are non-circular or not quite rotationally symmetrical about axis 16 ). In some embodiments, the term “rotationally asymmetric” encompasses any bearing wherein a portion of the mating surfaces have a minimum clearance space as described herein.
[0030] Optionally, the invention may further comprise a material 42 ( FIG. 4 ) such as metal (e.g., powdered metallurgy), diamond inlays, diamond particles, tungsten carbide, polycrystalline diamond and diamond-enhanced carbide wear surfaces located on at least one of the journal surface of the bearing pin 17 and the cylindrical cavity of the cone 23 .
[0031] As shown in FIGS. 5 and 6 , such materials 71 also may be formed on and/or incorporated into one or more surfaces 18 , 22 of the bearing pin 17 . For example, the materials 71 may include those described above, including a plurality of polycrystalline diamond bearing elements or inserts (e.g., assembled into a ring on a steel carrier ring 73 ), wherein the bearing surfaces are formed or machined to different radii. This bearing surface configuration may embody any of the variations described herein. In the embodiment shown, the two radii, R 1 and R 2 , have the same center but R 1 <R 2 .
[0032] In the illustrated embodiment of FIG. 3 , the journal surface 18 and/or 22 comprises a “pressure side” or direct contact surface (adjacent span 51 b ) formed at a first radius 61 . A “non-pressure side” or non-contact surface (adjacent areas 51 a, c, d ) is formed at a second radius 63 that is shorter than the first radius 61 .
[0033] The cylindrical cavity 27 defines a maximum potential contact area having an angular span of approximately 180° as shown in FIG. 3 . In one embodiment, the direct contact surface 51 b spans an angle 65 of at least 130° of said maximum potential contact area. The radial center 67 of the bearing pin 17 may be eccentric to a radial center 69 of the cone 23 (and the radial center of radius 61 ). This offset may comprise approximately the value of the radial bearing clearance. Alternatively, the bearing pin may be formed at two or more radii that originate from the same radial center. In still another alternative, only a portion 51 b of the journal surface 18 , 22 may be formed at the radius 61 that matches the radius of the cylindrical cavity 27 .
[0034] In alternate embodiments (e.g., FIGS. 7-10 ), the second radius may be equal to or greater than first radius 61 . For example, FIG. 7 depicts an embodiment wherein the pressure and non-pressure sides of the pin have equal radii 75 , 77 (e.g., 0.990 inches) that originate from different centers 79 , 81 , respectively. FIG. 8 illustrates an embodiment wherein pressure side radius 83 (e.g., 0.990 inches) is greater than non-pressure side radius 85 (e.g., 0.950 inches), but they originate from the same center 87 . FIG. 9 depicts an embodiment where the pressure side radius 89 (e.g., 0.990 inches) is greater than the non-pressure side radius 91 (e.g., 0.950 inches), and they originate from different centers 93 , 95 , respectively. FIG. 10 illustrates an embodiment where the pressure side radius 97 (e.g., 0.990 inches) is less than the non-pressure side radius 99 (e.g., 1.030 inches), and they originate from different centers 101 , 103 , respectively.
[0035] In another embodiment, the zero clearance conforming bearing surfaces are created in combination with spherical bearing surface curvature to further increase bearing contact area under conditions when the cone misaligns on the bearing pin.
[0036] While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.
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A rock drilling bit having PDC radial bearings has journal and cone bearing surfaces with increased contact area to increase load support. The radius of curvature of the bearing pin journal and cone bearing surfaces are matched or conformed on the bearing pressure side. The conformal journal surfaces may be formed on the main journal bearing, the pilot pin radial bearing, or both surfaces. In addition, diamond inlays may be located on the bearing surfaces of the cone, the bearing pin, or both components.
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The invention refers to a gripper loom, especially a rapier tape gripper loom with insertion rapier tapes and gripper bodies having warp thread supports outside of the path of insertion and retraction of the gripper head.
STATEMENT OF THE PROBLEM
In the gripper looms widely distributed today a bringer gripper inserts the weft yarn into the middle region of the shed, where it is taken over by a taker gripper. As shown in the EP 0 352 223 the warp threads are usually laid on a guide track and the gripper bodies are slid by their insertion rapier tapes over the warp threads supported by means of the guide track. The warp threads in the region of the weft insertion are therefore subjected to mechanical loading the result of which may be damaged or severed warp threads. Apart from the supporting guide track there are within the shed no guide devices acting directly upon the gripper, so that it is solely the insertion rapier tapes which act upon the grippers to determine their direction and guide them.
The force acting via the insertion rapier tape for accelerating or braking the respective gripper does not engage absolutely with the center of gravity of the gripper, or the gripper's sliding face or the guide track exhibit, e.g., unevennesses, in particular because of deposits of dirt, the consequence of which is that at intervals the gripper rises from the base supporting it and flies through the open shed. Thus, for example, in a first phase of insertion a gripper may fly over the warp threads, only to slam down onto the warp threads during braking and slide on them up to transfer of the weft yarn. The impact of the gripper causes injured, bruised warp threads or makes shiny places in the cloth. In particular towards the middle of the length of cloth a risk exists of severe soiling of the cloth since particles caused by friction, such, e.g., as slivers of yarn, are deposited in the warp threads in the region of the gripper as it slams down, slides, is braked or changes its direction of motion. The particles caused by friction lie especially on the surface of the guide track so that the respective warp threads are pressed into the particles through the weight of the gripper and become soiled. But soiling of the warp threads may also occur on the side next the gripper since the gripper slides directly on the warp threads and hence particles caused by friction may be forced into the warp threads.
A circumstance that further contributes to soiling of the cloth is that after transfer of the yarn has been effected the gripper as it slides over the warp threads within the shed is being accelerated in the direction of the rapier tape drum. Since the warp threads are lightly clamped between the gripper head and the guide track at the time, the gripper heads running out at high acceleration, especially in the region of the middle of the weave, cause a force to act upon the warp threads in the direction of withdrawal, so that predominantly the warp threads lying in the middle of the weave experience a deflection acting transversely to their alignment, which makes the warp threads slide to and fro on the supporting guide track during the repeated weft yarn insertion. Besides possible damage to the warp threads this transverse movement of the warp threads caused by frictional forces engaging them directly, brings about additional soiling of the warp threads, in particular in the middle of the weave and thereby soiling of the cloth.
In the EP 0 446 561 elements for maintaining pitch in gripper looms are disclosed, which penetrate between the warp threads and support a gripper sliding in the shed in such a way that it does not come to lie on the warp threads. But the pitch-maintaining elements entering the open shed from below may in doing so injure warp threads. Therefore there are fabrics which cannot reliably be woven with pitch-maintaining elements penetrating them, for example, fabrics with a high warp thread density such as very fine fabrics with a density in the range of 190 warp threads per cm. Again, the disadvantage persists that the pitch-maintaining elements entering certain weaves cause streakiness in the warp, the consequence of which is irregularities in the appearance of the goods. The problem of the present invention is to eliminate or at least reduce the interaction between grippers, warp threads and guide track in such a way that injuries to the yarn and soiling of the yarn by grippers or guide track do not occur or occur less often.
SUMMARY OF THE INVENTION
The insertion rapier tapes usually exhibit great stiffness in the horizontal direction whereas in the vertical direction they are very flexible so that the insertion rapier tape may be wound round a rapier tape drum. At high warp thread densities, for well known reasons pitch-maintaining elements entering the shed must be waived. It therefore cannot be avoided that the grippers and also under certain circumstances the insertion rapier tapes cover at least parts of their travel during insertion and withdrawal, sliding upon the warp threads. Equally it often cannot be avoided that the gripper during the insertion phase of the weft yarn drops with a bump on the warp threads. In the present invention the warp threads are protected by the warp threads which are in the lower shed at the time, being resiliently supported.
At least in the area over which bringer or taker grippers slide in contact with the warp threads, the warp threads of the lower shed are supported resiliently, preferably in the direction of gravity. For doing that the warp threads may in this area be supported elastically by, for example, the supporting hard surface of the guide track being coated with an additional elastic layer or by the whole guide track consisting of an elastic material so that the warp threads of the lower shed are supported elastically at least in the direction of gravity. This kind of execution of the guide track is suitable even for supporting a gripper with the loom at standstill, e.g., by the guide track under the warp threads lying offset slightly in the direction of gravity and only carrying the gripper with the loom at standstill.
A further possibility of achieving yielding properties in the area mentioned consists in supporting the warp threads only outside the area swept by the grippers. An appropriate supporting member may be realized, for example, as narrow warp-thread bearer rails which support the warp threads in parallel with the direction of motion of the grippers outside the swept area. In the case of bearer rails which are inelastic or not very elastic, for example, metallic bearer rails, it is predominantly the elastic properties of the warp threads which bring about the resilient properties in the swept area. Naturally the bearer rails may also be created in such a way that they have yielding properties, e.g., by plastics having the elasticity of rubber being employed.
Again, the devices supporting the warp threads of the lower shed may be combined, for example, by the warp threads of the lower shed in the region in the middle of the weft yarn insertion within which the grippers definitely slide on these warp threads, being supported by bearer members of the kind which engage outside the swept area, whereas in both regions towards the respective selvedges a guide track supports the warp threads.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described below with the aid of embodiments. There is shown in:
FIG. 1 --the elevation of one half of a gripper loom, seen from the cloth side;
FIG. 2 --a section of a sley with bearer members in accordance with the invention and a gripper head;
FIG. 3 --a cross-section through the shed and the sley with bearer members;
FIG. 4 --a further cross-section through a shed with sley and bearer members;
FIG. 5 --a further cross-section through a shed with sley and a U-shaped bearer member.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 a rapier tape gripper loom is represented with a sley 1 and a reed 2. The rapier tape drum 8 moves the bringer gripper head 3a which is connected to the rapier tape drum 8 via the insertion rapier tape 9, to and fro in the shed. The taker gripper head 3d moves in the opposite sense to the bringer gripper head 3a and takes over the weft yarn each time in the middle of the weave. The frame 10a of the loom and the base 10b, the cloth 6a with a slevedge 6e and the width of the cloth shown by A, as well as the cloth beam 6b are also represented.
The perspective in FIG. 2 shows a sley 1 to which are fastened a reed 2 and two bearer members 4, 5 for supporting the warp threads 7b of the lower shed. The heald eyes 12a and 12b determine at any time the angle of opening of the shed formed by the warp threads 7a and 7b. A bringer gripper head 3a is also shown, which inserts a weft yarn 11 into the shed formed by the high level warp threads 7a and the low level warp threads 7b. The bringer gripper head 3a is shown slightly enlarged in comparison with the sley 1. For the sake of clarity the taker gripper head 3d is not shown which would approach inside the shed in the opposite direction to the bringer gripper head 3a. The width of the cloth 6 is designated by A. The bringer gripper head 3a which has a width B in the direction of the warp threads rests across its whole width B on the lowlevel warp threads 7b. The area AB is an area of length A and width B and designates that zone of the lowlevel warp threads 7b over which the two gripper heads 3a, 3d slide or fly during each weft yarn insertion. At the latest towards the middle of the weave the two gripper heads 3a and 3d lie on the low level warp threads 7b and slide into one another, whereupon the yarn 11 is taken over by the taker gripper head 3d and thereupon the two gripper heads 3a and 3d are pulled out of the shed by the insertion rapier tapes 9, sliding mainly on the warp threads 7b. No guide elements are provided inside the shed for the gripper heads 3a and 3d, so that the direction of insertion of the gripper heads 3a and 3d is determined mainly by the insertion rapier tapes 9 which are stiff in the direction of the cloth beat-up. The position of the area AB on the lower warp threads 7b is therefore determined mainly through the arrangement of the rapier tape drums 8 and insertion rapier tapes 9 and at least in the direction of the cloth beat-up always remains approximately at the same place whereas the low level warp threads 7b move during the weaving process in the direction of beat-up. The width B of the region within which the gripper heads 3a and 3d slide or fly over the warp threads may also be greater than the effective width of a gripper head 3 since the insertion rapier tapes 9 are affected by play in the direction of beat-up. This play of the gripper heads 3 in the direction of the warp threads has the effect that the width B of the area AB swept by the gripper heads may become slightly greater than the effective width of the gripper heads 3. For supporting the warp threads 7b the bearer member 4 is arranged as a bearer rail adjoining the reed 2 on its beat-up side and running in parallel with it. The second bearer member 5 is fastened to the sley 1 offset and parallel with the beat-up edge 6c of the cloth, in such a way that the warp threads 7b of the lower shed are supported only outside the area AB by the bearer rails 4 and 5.
A gripper head 3 which during weft yarn insertion drops onto the warp threads 7b is damped springily by their not being supported within the region of the area AB. In that case it has to be taken into consideration that the warp threads 7b are preferably deflected only within their elastic range, which means that an appropriate number of warp threads 7b of an appropriate tensile strength must be present in the lower shed. For strong loadable warp threads such as those employed, e.g., in the production of wire cloth a correspondingly small number of supporting warp threads 7b is necessary in the lower shed. On the other hand, in the case of very fine weaves a correspondingly large number of supporting warp threads 7b is necessary.
In completion of FIG. 2 FIG. 3 shows a cross-section through a similar arrangement. In supplement a cloth-supporting rail 6d is shown for supporting the cloth 6a in the region of the cloth beat-up edge 6c, as well as fastener means 51 for fastening and setting the position of the warp thread bearer rail 5 on the sley 1. The gripper head 3 differs from the embodiment represented in FIG. 2. From the cross-section a gripper head 3 having a housing 3b and inner components 3c may be seen. The housing 3b lies like a sledge with two runners 3e on the warp threads 7b. One advantage of this execution of gripper may be seen, for example, in that the width B sweeping the warp threads 7b may be chosen wider than the actual gripper housing 3b. The gripper 3 thereby slides over the warp threads 7b in a more stable manner. During at least one part of the weft yarn insertion the warp threads 7b rest on the warp thread bearer rails 4 and 5 and are lowered, coupled with the beat-up movement of the sley 1, in order after the change of shed has been effected to support the low level warp threads 7b again during the next weft yarn insertion.
The warp thread bearer rails 4 and 5 are represented in the present embodiment as separate elements. Naturally a U-shaped element the two arms of which running in parallel exhibit at least a separation B, can fulfill the same function as the two separate bearer rails 4 and 5.
In FIG. 4 a further possibility is represented for supporting the low level warp threads 7b. The warp threads 7b are supported against the direction of gravity primarily by the cloth supporting rail 6d as well as the heald eyes 12b which guide the warp threads of the lower shed. Only from a certain loading or bending respectively of the warp threads 7b do the warp thread bearer rails 4 and 5 in the embodiment represented take over a supporting function. The bearer member 4 is fastened to the sley 1 by a fastener 42 on the side next the heald eye 12b. The bearer member 4 may also be connected rigidly to the loom frame 10a (see FIG. 1) in the position shown, so that only the bearer member 5 lying between the sley 1 and the cloth beat-up edge 6c and coupled to the sley 1 executes with it each beat-up movement.
In FIG. 5 a U-shaped bearer member 4 is represented, the two warp thread supporting rails 4b of which run on both sides outside the insertion area AB in parallel with the direction of motion of the grippers. In contrast to FIG. 3, in the embodiment in accordance with FIG. 5 the two warp thread supporting rails 4b are one constituent of a single bearer member 4. The bearer member 4 exhibits a connection between the warp thread supporting rails 4b, the surface 4a of the bearer member 4 next the warp threads being made, for example, as a plane area which extends between the warp thread supporting rails 4b in the direction of motion of the grippers. The two warp thread supporting rails 4b project above the area 4a by at least 1 mm so that during the weft yarn insertion the area 4a exercises no supporting function upon the warp threads 7b of the lower shed. But with the loom at standstill and the warp threads 7b at least slightly slackened it may, for example, in partial regions of the area AB, be possible for warp threads 7b and a gripper 3 which is perhaps lying on them, to rest upon the area 4a of the bearer member 4.
In order to avoid or reduce the deposit on the area 4a of particles caused by friction it may prove advantageous to provide the bearer member, for example, in the direction of gravity, with openings such as drilled holes, shown as DH in FIG. 5 the said particles are led away via the openings.
Both in the arrangement in accordance with FIG. 3 and in accordance with FIG. 4 and FIG. 5 each of the bearer members 4 or 5 may be arranged in such a way that in the position for weft yarn insertion they touch the lowlevel warp threads 7b in support or else exhibit a small clearance in which case the clearance may lie in a range of up to one millimeter so that the supporting elements 4 and/or 5 act in support only in the case of correspondingly greater deflections. For example, holes of 0.5 mm may be used.
Depending upon the properties of the warp threads 7a, 7b and further supporting devices like the cloth supporting rail 6d or heald eyes 12b it may even be sufficient to provide only one additional bearer member 4 or 5 for the additional support of the warp threads 7b.
The bearer members 4 and 5 may in turn also exhibit springy or resilient properties and be produced from metallic materials or from plastics.
In the present embodiment the device in accordance with the invention has always been described in connection with a rapier tape gripper loom. But the device in accordance with the invention is equally suitable for rapier gripper looms.
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A rapier tape gripper loom having inserter rapier tapes driving inserter and taker gripper heads has the warp threads only provide gripper head support over at least part of the insertion path. The insertion path occupies a width of the shed defined by the path of insertion and retraction of the gripper heads. It is the warp threads of the lower shed which act exclusively as direct support to the gripper heads over the part of the insertion path. During the insertion of the weft yarn, at least one bearer member supports the warp threads alongside of but not in the insertion path. This support effected by the at least one bearer member is outside the insertion path over which the gripper heads travel, leaving the warp threads as adjacently supported by the bearer member as the sole supporting members for the gripper heads.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application incorporates by reference and claims priority to U.S. Provisional Application 62/161,736, filed May 14, 2015, for Video Processing Unit for a Visual Prosthesis. This patent application is related to and incorporates by reference U.S. Pat. No. 8,798,756 for Video Processing Unit for a Visual Prosthetic Apparatus. The present invention represents a next generation improvement over the devices described in U.S. Pat. No. 8,798,756. The users controls described here are intended to work with a visual prosthesis system as described in U.S. Pat. No. 8,798,756.
FIELD OF THE INVENTION
[0002] The present disclosure is directed to a video processing unit for a visual prosthesis, and more specifically to improved user controls for a visual prosthesis.
SUMMARY OF THE INVENTION
[0003] The present invention is an improved visual prosthesis including a video processing unit with user controls optimized for use by blind individuals. The controls include easily identifiable shapes. The controls are programmable to provide improved usability with a simple tactile interface. A programmable slider serves a variety of input functions.
DESCRIPTION OF THE FIGURES OF THE DRAWING
[0004] FIG. 1 is a top right perspective view of the video processing unit.
[0005] FIG. 2 is a front view of the video processing unit.
[0006] FIG. 3 is a rear view of the video processing unit.
[0007] FIG. 4 is a right side view of the video processing unit.
[0008] FIG. 5 is a left side view of the video processing unit.
[0009] FIG. 6 is a top view of the video processing unit.
[0010] FIG. 7 is a bottom view of the video processing unit.
[0011] FIG. 8 is a perspective view of the glasses.
[0012] FIG. 9 is a perspective view of the implanted portion of the visual prosthesis.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] Referring to FIGS. 1-7 , user input controls on the housing of the video processing unit 2 include a power button 4 and a mute button 12 on the top of video processing unit 2 housing. The power button is depressed for a predetermined time, about a second, to turn the video processor 2 on or off. The mute 12 button mutes audio feedback. On the face of the video processing unit 2 housing is an analog slider 8 . In the default mode, the analog slider 8 controls brightness. The analog slider is a potentiostat that returns its value to the microprocessor in the video processing unit 2 through an analog to digital converter. It can be programmed for any function. Alternate functions can include gain, sensitivity (including separate indoor and outdoor settings), exposure, contrast or zoom (zoom in, zoom out, and 1-1), total brightness limit (useful for photo phobic patients) and frequency of stimulation.
[0014] Below the analog slider 8 is a three position selector switch 10 to choose between programmable options. The three position selector switch includes tactile marks 11 to aid blind users. The three position selector switch is also programmable for function. The position selector switch can select between predefined filters or alter the function of the analog slider 8 as discussed above. Below the three position selector switch 10 is an invert switch 6 . The invert switch 6 inverts the image, light is dark and dark is light. All of the buttons are programmable to multiple functions. As an example, the power button 4 and the mute button 12 can be programmed as yes and no responses to menu functions. An additional programmable button 14 is on the bottom of the housing. The battery cover 22 is also on the bottom of the housing and includes tactile markings to aid the blind user.
[0015] The buttons are arranged to maximize use by blind users. Inset 16 surrounds the analog slider 8 , thee position selector 10 and invert switch 6 . This allows a user to quickly indentify the front and back of the video processing unit 2 housing and to find the location of user controls. Top and bottom orientation is achieved by the location of the data cable 18 in the top. The data cable 18 is connected to the top via the data cable connector 24 . The video processing unit 2 further includes a speaker 20 on the back side opposite the user controls. The speaker 20 can be used for informative signals like those associated with turning on or off, error warning or announcements supporting use of the menu system.
[0016] Referring to FIG. 8 , the glasses 25 may comprise, for example, a frame 31 holding a camera 32 , an external coil 34 and a mounting system 36 for the external coil 34 . The mounting system 36 may also enclose the RF circuitry. In this configuration, the video camera 32 captures live video. The video signal is sent to the Video Processing Unit 2 (shown in FIGS. 1-7 ), which processes the video signal and subsequently transforms the processed video signal into electrical stimulation patterns or data. The electrical stimulation data are then sent to the external coil 34 that sends both data and power via radio-frequency (RF) telemetry to the coil 116 of the retinal stimulation system 100 , shown in FIG. 9 . The coil 116 receives the RF commands which control the application specific integrated circuit (ASIC) inside the electronics package 114 , which in turn delivers stimulation to the retina of the subject via a thin film electrode array (TFEA) 112 . In one aspect of an embodiment, light amplitude is recorded by the camera 32 . The VPU 2 may use a logarithmic encoding scheme to convert the incoming light amplitudes into the electrical stimulation patterns or data. These electrical stimulation patterns or data may then be passed on to the Retinal Stimulation System 100 , which results in the retinal cells being stimulated via the electrodes in the electrode array 110 (shown in FIG. 9 ). In one exemplary embodiment, the electrical stimulation patterns or data being transmitted by the external coil 34 is binary data. The external coil 34 may contain a receiver and transmitter antennae and a radio-frequency (RF) electronics card for communicating with the internal coil 116 .
[0017] FIG. 9 shows a perspective view of the implanted portion of the preferred visual prosthesis. A flexible circuit 112 includes a flexible circuit electrode array 110 which is mounted by a retinal tack (not shown) or similar means to the epiretinal surface. The flexible circuit electrode array 110 is electrically coupled by a flexible circuit cable 112 , which pierces the sclera and is electrically coupled to an electronics package 114 , external to the sclera.
[0018] The electronics package 114 is electrically coupled to a secondary inductive coil 116 . Preferably the secondary inductive coil 116 is made from wound wire. Alternatively, the secondary inductive coil 116 may be made from a flexible circuit polymer sandwich with wire traces deposited between layers of flexible circuit polymer. The secondary inductive coil receives power and data from a primary inductive coil 34 , which is external to the body. The electronics package 114 and secondary inductive coil 116 are held together by the molded body 118 . The molded body 18 holds the electronics package 114 and secondary inductive coil 116 end to end. The molded body 118 holds the secondary inductive coil 116 and electronics package 114 in the end to end orientation and minimizes the thickness or height above the sclera of the entire device. The molded body 118 may also include suture tabs 120 . The molded body 118 narrows to form a strap 122 which surrounds the sclera and holds the molded body 118 , secondary inductive coil 116 , and electronics package 114 in place. The molded body 118 , suture tabs 120 and strap 122 are preferably an integrated unit made of silicone elastomer. Silicone elastomer can be formed in a pre-curved shape to match the curvature of a typical sclera. However, silicone remains flexible enough to accommodate implantation and to adapt to variations in the curvature of an individual sclera. The secondary inductive coil 116 and molded body 118 are preferably oval shaped. A strap 122 can better support an oval shaped coil. It should be noted that the entire implant is attached to and supported by the sclera. An eye moves constantly. The eye moves to scan a scene and also has a jitter motion to improve acuity. Even though such motion is useless in the blind, it often continues long after a person has lost their sight. By placing the device under the rectus muscles with the electronics package in an area of fatty tissue between the rectus muscles, eye motion does not cause any flexing which might fatigue, and eventually damage, the device.
[0019] The molded body 118 narrows into a fin tail 124 at the strap 122 . When implanting the visual prosthesis, it is necessary to pass the strap 122 under the eye muscles to surround the sclera. The secondary inductive coil 116 and molded body 118 must also follow the strap 122 under the lateral rectus muscle on the side of the sclera. The implanted portion of the visual prosthesis is very delicate. It is easy to tear the molded body 118 or break wires in the secondary inductive coil 116 . In order to allow the molded body 118 to slide smoothly under the lateral rectus muscle, the molded body 118 is shaped in the form of a fan tail 124 on the end opposite the electronics package 114 .
[0020] Accordingly, what has been shown is an improved visual prosthesis. While the invention has been described by means of specific embodiments and applications thereof, it is understood that numerous modifications and variations could be made thereto by those skilled in the art without departing from the spirit and scope of the invention. It is therefore to be understood that within the scope of the claims, the invention may be practiced otherwise than as specifically described herein.
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The present invention is an improved visual prosthesis including a video processing unit with user controls optimized for use by blind individuals. The controls include easily identifiable shapes. The controls are programmable to provide improved usability with a simple tactile interface.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] [0002] Thermoanaerobacter thermohydrosulfuricus (Tts) DNA polymerase has been cloned and expressed in E. coli and purified. A U.S patent (U.S. Pat. No. 5,744,312) has been recently issued to Amersham Life Science, Inc. A significant property of this polymerase is its ability to catalyze RNA-dependent DNA polymerase activity, reverse transcriptase activity (U.S. Pat. No. 5,744,312), in addition to its DNA dependent DNA polymerase. This polymerase performs optimally at a broad temperature range from 37-65 C. with maximal activity at 60 C. These activities combined with thermostability of the enzyme offer several benefits as discussed below. Several different variants of the enzyme have been generated for utility in DNA sequencing, for use in first-strand cDNA synthesis, RT-PCR and for strand displacement amplification.
[0003] 2. Description of Related Art
[0004] DNA polymerases and Reverse Transcriptases (RTs) isolated from various organisms ranging from bacteria, viruses, archaebacteria are being successfully used in the field of molecular biology for various applications. The growth temperatures for these organisms could range from extremely low to high. Applications of enzymes derived from the organisms range from cloning, polymerase chain reaction (PCR) (U.S. Pat. No. 4,683,195, Mullis et. al.), DNA sequencing, mutagenesis, genomic library construction, and nucleic acid labeling such as cDNA labeling for micro and macro arrays.
[0005] DNA Polymerases discriminate against the incorporation of unnatural bases during DNA synthesis. Most naturally occurring DNA polymerases also do not employ RNA as a template molecule. However, the natural template for a reverse transcriptase is both RNA and DNA. The natural building blocks for DNA polymerases and RTs are the four deoxy ribonucleotides (dATP, dGTP, dCTP and dTTP). Most naturally occurring polymerases and reverse transcriptases exhibit poor incorporation efficiencies towards most nucleotide analogs. The analogs could be any variants of naturally occurring dNTPs, such as ddNTPs, rNTPs, conjugates (dye or otherwise) of dNTPs and ddNTPs. This selection is important in the survival of the host. Frequent incorporation of non-natural bases would hamper subsequent rounds of replication resulting in the ultimate death of the organism. If and when polymerases do incorporate non-natural bases in their host, it is under extreme conditions that would lead to the ultimate survival of the organism. Such events however lead to mutations in the organism that may be needed for survival under extreme conditions. Therefore it is not unusual that native polymerases, having wild type amino acid sequence, either isolated directly from the host or by recombinant means exhibit a discriminatory effect towards non-natural nucleotides. Nevertheless, under very high concentrations of the analogs, native polymerases do incorporate these analogs during DNA synthesis albeit poorly. This feature is currently being exploited in all applications that use DNA polymerases or RTs for nucleic acid labeling. Consequently, the specific activity of the probe made using the naturally occurring polymerases or RTs is generally low. The current approaches to using natural enzymes for labeling encounter numerous technical difficulties. For example, incorporation of fluorescently labeled nucleotides by these naturally occurring enzymes can only be marginally improved by using excessive amounts of these labeled nucleotides in the reaction. But this imposes a different set of problems. It is generally difficult to remove the unused excess labeled nucleotides after the reaction, imposing serious problems with respect to poor signal to noise ratios. Additionally, a large amount of usually rare raw material is used to achieve marginal labeling. Apart from these problems, there is also sacrifice in the yield of the total probe generated. This is attributed to the discrimination by wild type polymerases and RTs to extend from an incorporated dNTP analog, such as a dye-dNTP. This again is a built-in feature of wild type polymerases and reverse transcriptases.
[0006] Higher specific activity probes are useful in multiple applications. This requires a facile addition of dye-dNMP followed by subsequent extension. Repeated rounds of addition of dye-dNMP and extension results in the formation of probes with higher specific activity. Since, naturally occurring polymerases and RTs are discriminatory to both addition and extension of a dNTP analog or dye-dNTP, the probes generated are of low specific activity.
[0007] As the above discussion suggests, a way of altering the natural properties of polymerases for better incorporation of nucleotide analogs during DNA synthesis, is desirable. For example, an improved ability to incorporate labeled nucleotides in various nucleic acid applications such as rolling circle amplification and single nucleotide polymorphism detection would be useful. This concern is addressed in greater detail below.
SUMMARY OF THE INVENTION
[0008] Accordingly, it is the object of the invention to provide an enzymatically active DNA polymerase having improved incorporation of nucleotide analogs and natural bases during DNA synthesis and a method of incorporating dye labeled dNTP's using the DNA polymerase or an active fragment thereof. It is a further object of the invention to provide a method of utilizing the DNA polymerase for performing direct RNA sequencing and to provide kits for labeling a polynucleotide from a DNA or RNA template with a DNA or RNA primer comprising the DNA polymerase.
[0009] The objectives are met by the present invention, which relates in one aspect to a DNA polymerase or active fragment thereof. The DNA polymerse or active fragment thereof, has at least 80% identity in its amino acid sequence to the DNA polymerase of Thermoanaerobacter thermohydrosulfuricus or a fragment thereof, and has an amino acid alteration at position 720 in Tts Pol I or at position 426 in ΔTts or at a homologous position defined with respect to Tts DNA polymerase, and has improved incorporation of nucleotide anaologs and natural bases during DNA synthesis, as compared to unaltered enzyme. In one embodiment the nucleotide analogs are dNTP, ddNTP and rNTP analogs. In a second embodiment the dNTP, ddNTP and rNTP analogs are dye-conjugated or biotin-conjugated. In a third embodiment the dye in the dye-conjugated nucleotide analogs is a rhodamine or Cyanine derivative dye. In a fourth embodiment the rhodamine dye is R110, R6G, TMR or Rox. In a fifth embodiment the Cyanine derivative dye is Cy3, Cy3.5, Cy5.0 or Cy5.5. In a sixth embodiment the DNA polymerase has the asparatate at position 720 in Tts Pol I or at position 426 in ΔTts Pol I, replaced with agrinine.
[0010] A related aspect of the invention relates to a method of utilizing the DNA polymerase of Thermoanaerobacter thermohydrosulfuricus or a fragment thereof, having an amino acid alteration at position 720 in Tts Pol I or at position 426 in ΔTts or at a homologous position defined with respect to Tts DNA polymerase, having improved incorporation of nucleotide analogs and natural bases during DNA synthesis, as compared to unaltered enzyme, for incorporating Cy3 and Cy5 dye conjugated dNTP's across a range of reaction temperatures form 37-65° C.
[0011] In a further aspect, the invention relates to a method of utilizing the DNA polymerase for performing direct RNA sequencing, while a further aspect relates to providing kits for labeling a polynucleotide from a DNA or RNA template with a DNA or RNA primer comprising the DNA polymerase.
[0012] The above objects and features of the invention will become more fully apparent when the following detailed description of the invention is read in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF DRAWINGS
[0013] [0013]FIG. 1. (SEQ ID No. 1) is the Amino acid sequence of the full-length of Tts DNA polymerase I. A full-length recombinant form of the enzyme, harboring both the native 5′-3′ DNA template mediated DNA polymerase function and 5′-3′ exonuclease. (Covered under U.S. Pat. No. 5,744,312) serves as a reference amino acid sequence. In addition, the enzyme harbors reverse transcriptase activity.
[0014] [0014]FIG. 1A. (SEQ ID No. 2) is the DNA sequence of the full-length of Tts DNA polymerase I (Covered under U.S. Pat. No. 5,744,312)
[0015] [0015]FIG. 2. (SEQ ID No. 3) is the amino acid sequence of the ΔTts DNA polymerase I. A 5′-3′ exonuclease deficient (exo−) form of the enzyme, with a truncation at the amino-terminus. (Covered under U.S. Pat. No. 5,744,312). Blocked portion represents the region of the deleted amino acids from the full-length version of the enzyme.
[0016] [0016]FIG. 2A. DNA sequence of the ΔTts DNA polymerase I. (SEQ ID No. 4). (Covered under U.S. Pat. No. 5,744,312)
[0017] [0017]FIG. 3. Amino acid sequence of the F412Y variant of the ΔTts DNA polymerase I. (Covered under U.S. Pat. No. 5,744,312). Blocked portion represents the region of the deleted amino acids from the full-length version of the enzyme (Position 412 in ΔTts corresponds to 706 in full-length enzyme, phenylalanine in this position is implicated in discrimination towards ddNTP. The F412Y change facilitates easy incorporation of ddNTP. (SEQ ID No. 5)
[0018] [0018]FIG. 3A. DNA sequence of the F412Y variant of the ΔTts DNA polymerase I. (SEQ ID No. 6). (Covered under U.S. Pat. No. 5,744,312)
[0019] [0019]FIG. 4. Amino acid sequence of the ΔTtsF412YD426R variant polymerase. Blocked portion is the deleted amino acids from the full-length version of the enzyme. Position 412 in ΔTts corresponds to 706 in full-length enzyme, phenylalanine in this position is implicated in discrimination towards ddNTP. Position 426 in ΔTts corresponds to 720 in full-length enzyme. Discrimination towards both incorporation and extension of a dye conjugates of dNTP, rNTP or ddNTP is governed by aspartate residue at this position. Mutation was generated by oligonucleotide based site-directed mutagenesis technique to introduce a Δ Tts D426R change in the Tts F412Y background. (SEQ ID No. 7)
[0020] [0020]FIG. 5. Amino acid sequence of the ΔTts D426R polymerase. Blocked portion is the deleted amino acids from the full-length version of the enzyme. Position 426 in ΔTts corresponds to 720 in full-length enzyme. Discrimination towards both incorporation and extension of a dye conjugates of dNTP, rNTP or ddNTP is governed by aspartate residue at this position. (SEQ ID No. 8)
[0021] [0021]FIG. 6. Alignment of wild type Pol I sequences from different microorganisms. Homologous positions around the “finger region” of Polymerases of Pol I family are shown here. Richardson, “DNA polymerase from Escherichia coli ,” Procedures in Nucleic Acid Research, Cantoni and Davies editors, Harper and Row, New York, pp. 263-276 (1966). Scopes, Protein Purification, Springer-Verlag, New York, N.Y., pp. 46-48 (1994).
[0022] [0022]FIG. 7. Improved incorporation of Dye (Cy 3.5)-dCTP and dCTP by ΔTts D426R form of ΔTts Pol I.
[0023] [0023]FIG. 8. Direct RNA sequencing by AMV RT, ΔTts and ΔTts F412Y Pol I.
[0024] [0024]FIG. 9. ΔTts F412YD426R performance in cDNA labeling using Cy3 and Cy5-dCTP and utility in microarray applications.
[0025] [0025]FIG. 10. ΔTts F412YD426R performance in cDNA labeling using Cy3 and Cy5-dUTP and utility in microarray applications.
[0026] [0026]FIG. 11. Usefulness of ΔTts F412Y or ΔTtsF412YD426R Pol I in single nucleotide primer extension (SnuPE), using RNA templates. Incorporation of dye labeled or unlabeled ddA, ddT, ddG and ddC is demonstrated here.
[0027] [0027]FIG. 12. Utility of ΔTts DNA polymerase in Rolling Circle Amplification reaction
[0028] [0028]FIG. 13. Incorporation of dye labeled nucleotide during DNA dependent DNA synthesis ΔTts, ΔTts F412Y, ΔTts F412YD426R.
[0029] [0029]FIGS. 14 a & b. ΔTtsF412YD426R Performance in cDNA labeling using Cy3/Cy5-dCTP; demonstration of accurate determination of gene expression over a wide reaction temperature range (FIGS. 14 a and b ).
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention discloses the utility of native DNA pol I and variant forms of DNA Pol I of Thermoanaerobacter thermohydrosulfuricus for nucleic acid labeling by fluorescent nucleotide analogs. Utility in applications such as cDNA labeling, rolling circle amplification, RNA sequencing and single nucleotide primer extension on RNA is also covered.
[0031] In this present invention we have found ways of altering the natural properties of polymerases for better incorporation of nucleotide analogs during DNA synthesis. Described here are modifications that can be introduced to the naturally occurring polymerases/reverse transcriptases to facilitate incorporation of fluorescent labeled nucleotides. The present invention identifies a single amino acid residue in polymerases that is responsible for improved incorporation of certain nucleotide analogs. A change in amino acid residue results in a profound increase in the ability of the enzyme for incorporation and extension from dye labeled nucleotides. This feature is useful in any nucleic acid application that employs fluorescent labeling by incorporation of nucleotide analog by a DNA polymerase. Such applications include labeling during DNA synthesis in various applications such as microarray analysis of gene expression. We also show the utility of some variants of the enzyme in direct RNA sequencing, rolling circle amplification, single nucleotide polymorphism detection (SNP) by single nucleotide primer extension utilizing either DNA or RNA templates. This invention relates to the wild type and mutant forms of the enzymes and their DNA sequence and amino acid sequence and the vectors that are used to generate them.
[0032] The first aspect of the invention relates to the generation and purification of a variant form of the native DNA Pol I of Thermoanaerobacter thermohydrosulfuricus and of sequences of polymerases that are at least 80% amino acid sequence identity as shown in FIG. 1 (U.S. Pat. No. 5,744,312).
[0033] [0033]FIG. 1 shows the reference sequence of the amino acid encoded by the genomic DNA between positions 1056-3674 of the Tts revealed in patent (U.S. Pat. No. 5,744,312) (SEQ ID No. 1). Enzymes have been engineered in the previous disclosure to abolish an associated 5′-3′ exonuclease function in the native enzyme and is shown here as reference sequence in FIG. 2.
[0034] For ease of reference FIGS. 1, 2 and 3 are illustrated here (covered under U.S. Pat. No. 5,744,312). FIG. 1 is a full-length recombinant form of the enzyme, harboring both the native 5′-3′ DNA template mediated DNA polymerase function and 5′-3′ exonuclease. (covered under U.S. Pat. No. 5,744,312) serves as a reference amino acid sequence as shown in FIG. 1. The full-length version of the enzyme henceforth in this document will be referred to as Tts DNA Pol I.
[0035] [0035]FIG. 2 is a 5′-3′ exonuclease deficient (exo−) form of the enzyme, with a truncation at the amino-terminus. (covered under U.S. Pat. No. 5,744,312). Henceforth this form of the enzyme will be referred to as ΔTts enzyme. The numbering of amino acids for truncated form of the enzyme begins with the first amino acid of the truncated form. Additionally in some instances numbering of amino acids in this document is also indicated on non-truncated full-length version of the enzyme for easy comparison.
[0036] [0036]FIG. 3 is an exonulease deficient truncated version form of the enzyme with an F (phenlyalanine) to Y (Tyrosine) change in the O-helix region at position 412, and is shown for reference (covered under U.S. Pat. No. 5,744,312)
[0037] [0037]FIG. 4 is the enzyme showing the introduction of a point mutation altering the Aspartate (D) residue at 426 to Arginine (R) in ΔTtsF412Y form of the enzyme. This form of the enzyme henceforth will be referred to as ΔTtsF412YD420R.
[0038] [0038]FIG. 5 shows another form of enzyme referred to as ΔTtsD426R by reversing the tyrosine (Y) residue at 412 back to phenylalanine (F) of ΔTtsF412Y form of the enzyme. Single letter amino acids are according to conventional codes used in the literature.
[0039] U.S. Pat. No. 5,744,312 shows utility for the native Tts, ΔTts, ΔTtsF412Y in applications ranging from cDNA preparation, strand displacement amplification (Walker et al., “Isothermal in vitro amplification of DNA by a restriction enzyme/DNA polymerase system,” Proc. Natl. Acad. Sci. USA 89:392-396 (1992)) and DNA sequencing.
[0040] The present application shows the utility of various forms of Tts enzyme in the incorporation of non-natural base analogs during DNA synthesis. Some examples are the incorporation of either unlabeled or dye-labeled versions of dNTPs, ddNTPs and rNTPs. DNA synthesis can be either DNA template mediated (DNA polymerase activity) or RNA template mediated (reverse transcriptase activity). DNA or RNA template-mediated cDNA probes are increasingly in demand for microarray applications. This invention demonstrates the utility of the enzyme variants in nucleic acid labeling during DNA synthesis with particular emphasis on microarray applications for gene expression studies.
[0041] Incorporation of ddNTP or ddNTP analogs is extremely useful in applications such as DNA or RNA sequencing. Herein it is demonstrated that ΔTtsF412Y and ΔTtsF412YD426R forms of the enzyme holds great promise for applications such as direct RNA sequencing and situations where single nucleotide primer extension is monitored. For example it can be seen that the F412Y variant is capable of generating excellent sequence information from short stretches of RNA compared to retroviral reverse transcriptases. Experimental results are also presented to document the utility of some enzyme variants in single nucleotide primer extension (SnuPE) applications for interrogation of target sequence of DNA or RNA backbone.
[0042] This finding is useful in applications that involve single polymorphism detection, mutation detection in DNA or RNA. Direct mutation detection at RNA level is useful in many respects. An example of such an application would be to determine drug resistance mutations in Human Immunodeficiency viral (HIV) RNA from patients undergoing drug treatments. Resistance mutations to HIV reverse transcriptase and protease inhibitors are attributed directly to mutations in the genes encoding these proteins in the RNA genome. Additionally, in humans and higher organisms improper splicing of RNA leading to defective mRNA is implicated in major disorders. Direct RNA sequencing of limited stretch such RNA or direct detection of improperly spliced RNA by mutation detection using SnuPE is feasible with the ΔTtsF412Y or ΔTtsF412RD426R variants. These would be different from current approaches that are being followed. Since retroviral RTs are not good sequencing enzymes, in current approaches a RT-PCR step is required before sequencing is undertaken.
[0043] In addition to mutation detection, Tts Pol I variants can be used for estimating RNA copy number. This has value in HIV research or gene expression studies. The enzyme's ability to incorporate dye-terminators and its potential for incorporating dye-labeled dNTP and ddNTP during cDNA synthesis can be capitalized on for estimating copy number of HIV-RNA, hence for estimating virus titer. This property of dye-labeled nucleotide incorporation by ΔTtsD426R would also be useful in mRNA quantification and gene expression studies on micro or macroarrays. The alternative strategies that are currently being employed: 1) quantitative RT-PCR used for estimating viral RNA and mRNA. 2) Branched DNA/nuclease excision for viral and mRNA quantitation.
[0044] The utility of Tts enzyme variants in strand displacement amplifications such as Rolling Circle Amplification (RCA) is also demonstrated in this invention.
EXAMPLES
[0045] The following examples serve to illustrate the utility of the subject DNA polymerases and are for illustration purposes only and should not be used in any way to limit the appended claims.
Example 1
[0046] Generation of ΔTts F412YD426R Variant (FIG. 4)
[0047] The expression vector PLS-3 harboring ΔTts F412Y variant disclosed in U.S. Pat. No. 5,744,312 served as a starting plasmid for this invention. Primers were designed to alter the codon encoding the residue 426 of ΔTts pol I from asparate to arginine. A forward primer of sequence “gggctttctcgacgccttaaaatatca” (SEQ ID No. 9)(encoding positions 422 to 430) and a complementary sequence was employed to introduce the intended point mutation. The new codon used for amino acid R was “cgc”. The primers were annealed and a cycling reaction with Pfu DNA polymerase was carried out in the presence of all four dNTPs to generate new strands. The final product was used in transformation of E. coli strain and colonies were screened individually by DNA sequencing to select for clones with desired mutation.
Example 2
[0048] Generation of ΔTts D426R Variant (FIG. 5)
[0049] A clone containing the plasmid with ΔTts F412YD426R variant shown in example 1 above served as a starting material for the generation of ΔTts D426R variant. A strategy similar to above was employed. Two primers complementary to each other were designed to introduce the intended original phenylalanine “F” residue at position 412 of ΔTts F412YD426R. A forward primer GCCGTAAATTTTGGCATAATATATGGC (SEQ ID No. 10)(to span positions 409 to 417 of the ΔTts F412YD426R polymerase) and a complementary sequence was employed to change “Y” residue were designed. A codon “TTT” for phenylalanine was employed to engineer the change.
Example 3
[0050] Alignment of Wild Type Pol I Sequences from Different Microorganisms FIG. 6.
[0051] Homologous positions in finger region of Polymerases of Pol I family are shown here. Note the alignment of amino acids corresponding to 720 of full-length (position 426 of ΔTts) Tts Pol I. The blocked region demonstrates the region of homology between the enzymes. The role of phenlyalanine at positions corresponding 706 of Tts Pol I in discrimination towards ddNTPs is shown for reference and has been documented in literature. The claims of this patent cover the role of amino acid at position 720 of full-length Tts DNA polymerase I. Alteration of this amino acid results in easy incorporation of dye-labeled nucleotide analogs. A negatively charged amino acid at this position is more discriminatory towards the incorporation of dye-labeled nucleotide. An alteration to positively charged residues such as arginine or lysine or other bulky residues results in the lowering of discrimination towards the dNTP or ddNTP conjugates. Besides the usefulness of other naturally occurring polymerases for dye nucleotide labeling, that naturally harbor residues other than glutamate or aspartate are also covered in this patent.
Example 4
[0052] Assay Conditions
[0053] The experiment shown in FIG. 7 investigates the relative efficiencies of incorporation of dye-CTP (Cy3.5-dCTP) and dCTP. Three enzyme preparations ΔTts, ΔTts F412Y, ΔTtsF412YD426R were analyzed in this experiment.
[0054] Optimized 1×buffer compositions for Reverse Transcriptase (RNA dependent DNA Polymerase) and DNA Polymerase (DNA dependent DNA polymerase) reactions for all variants of Tts Pol I are as follows. Tris, pH 8.0 (50 mM), KCl (40 mM), MgCl2 (3 mM), DTT (1 mM), DNA or RNA template (as needed), primer (5 to 50 femto mols), enzyme 0.5 to 1 units, dNTP or dNTP analog (varying concentrations as needed). In standard synthesis reactions, when full-length synthesis is monitored, 50 uM of all 4 dNTPs are included. Typical reaction volume is 10 ul. Reaction temperature was kept between 37-60 C. depending on the experimental needs. Reaction time was limited to 10 minutes for single nucleotide incorporation studies. Time was varied as needed for the purpose of the experiments, sometimes up to 1 hour if longer extensions are monitored.
[0055] The experiment shown in FIG. 7 investigates the relative efficiencies of incorporation of dye-CTP (Cy3.5-dCTP) and dCTP. Three enzyme preparations ΔTts, ΔTtsFY, ΔTtsF412YD426R were analyzed in this experiment.
[0056] In FIG. 7, Globin mRNA served as the template. A 5′ P-33 labeled primer (DNA 25-mer) was annealed to the template. Reactions were performed with varying concentrations of either Cy3.5-dCTP or dCTP alone. Inclusion of only one dNTP allowed incorporation of the next correct nucleotide alone. The sequence of the template-primer that allowed for the examination of single nucleotide “C” incorporation is shown below.
CAGGCTGCCTATCAGAAGGTGGTGGCTGGTGTGGCCkATGCCCTGGCTCA 5′ 3′ mRNA (SEQ ID No. 11) TTCCACCACCGACCACACCGGTTACGG* CP-16 3′-5′ (SEQ ID No. 12)
[0057] Lanes 1,2,3 and 4 contain 20, 2, 0.2, and 0.02 uM of dNTP or dye-dNTP. Lane with no label has no enzyme, to show the integrity of the starting P-33 labeled primer. Quantification of the single nucleotide extension product is one way to tell if DR change to in the enzyme led to any consequence. “P” indicates a radio labeled primer. “P+1” represents the elongated product by a single nucleotide or nucleotide analog. P+1 migrates slowly with the dye-dNTP conjugate. Note that the migration of Cy3.5 dCMP containing bands travel slowly on the gel compared to dCTP extended products. Comparing Panel A, B and C, lanes 1 through 4 shows that the alteration of the amino acid back bone of the enzyme from D to R results in the improved efficiency of natural nucleotides. P+1 product is achieved between 10-100 fold less concentration of dCTP with the enzyme having the DR change Likewise, a comparison of panels A′, B′ and C′ reveals that the alteration DR results in improved incorporation of dye-CTP. Essentially, incorporation is achieved at lower concentrations (less than 10 times) of dye-dNTP compared to that of the wild type polymerase. It is evident that the DR enzyme was able to incorporate Cy3.5 dCTP at concentrations as low as 0.2 uM (Cy3.5 dCTP) or even lower. Compare this with the D enzyme, which exhibits relatively poor incorporation at these lower concentrations. And the results also show that this mutation dramatically reverses the decreased incorporation of dye-CTP seen with Tts F412Y in panel B′. In this experiment the template-primer is a mRNA annealed to radio labeled primer. Extension is monitored qualitatively as P+1 for the natural nucleotides and P+1* for dye labeled nucleotide. This is a promising first observation for potential use in microarray applications for cDNA probe labeling.
Example 5
[0058] Direct RNA Sequencing by AMV RT, ΔTts and ΔTtsF412Y Pol I (FIG. 8).
[0059] Globin mRNA served as a template. The 50-mer DNA was used a primer. Standard sequencing components in Amersham Pharmacia Thermo Sequenase kit were employed for sequencing. P-33 labeled terminators (ddNTP) were obtained from Amersham Pharmacia Biotech. Post-sequencing reaction products were separated on 6% urea-polyacrylamide gels. AMV, Avian Myeloblastosis virus RT.
Example 6
[0060] ΔTtsF412YD426R Performance in cDNA Labeling Using Cy3 and Cy5-dCTP and Utility in Microarray Applications (FIG. 9).
[0061] A typical 20 μl reaction Cy3 or Cy5 reaction had 1 μg of human skeletal muscle mRNA, oligo dT (25) and random nonamer primers and TtsFYDR polymerase enzyme in 1×reaction buffer (50 mM Tris, pH 8.0, 1 mM DDT, 40 mM KC, 100 uM dA,G and TTP and 50 um each of CTP and Cy3-dCTP or Cy5-dCTP depending on the reaction). Control mRNAs (APBiotech Inc.) of known sequence compositions were included in various concentrations to serve as dynamic range and gene expression ratio controls. Tts reactions were carried out at temperatures from 50 degrees C. Template RNA was hydrolyzed by alkali treatment and neutralized with HEPES.
[0062] Probes were purified using MultiScreen filters (Millipore) and quantified by spectrophotometry. Glass slides containing human cDNA gene targets were hybridized with equal amounts (30 pmol each) of Cy3 and Cy5 labeled cDNA probes. Slides were scanned using a GenePix® (Axon) scanner and quantified using ImageQuant software. The figure illustrates the accurate representation of probes, near even incorporation of Cy3 and Cy5 and differential gene expression in Cy3 versus Cy5 reactions.
Example 7
[0063] ΔTtsF412YD426R Performance in cDNA Labeling Using Cy3 and Cy5-dUTP and Utility in Microarray Applications (FIG. 10).
[0064] A typical 20 μl reaction Cy3 or Cy5 reaction had 1 μg of human skeletal muscle mRNA, oligo dT (25) and random nonamer primers and TtsFYDR polymerase enzyme in 1×reaction buffer (50 mM Tris, pH 8.0, 1 mM DDT, 40 mM KC, 100 uM dA,G and CTP and 50 um each of TTP and Cy3-dUTP or Cy5-dUTP depending on the reaction). Control mRNAs (APBiotech Inc.) of known sequence compositions were included in various concentrations to serve as dynamic range and gene expression ratio controls. Tts reactions were carried out at temperatures from 50 degrees C. Template RNA was hydrolyzed by alkali treatment and neutralized with HEPES.
[0065] Probes were purified using MultiScreen filters (Millipore) and quantified by spectrophotometry. Glass slides containing human cDNA gene targets were hybridized with equal amounts (30 pmol each) of Cy3 and Cy5 labeled cDNA probes. Slides were scanned using a GenePix® (Axon) scanner and quantified using ImageQuant software. The figure illustrates the accurate representation of probes, near even incorporation of Cy3 and Cy5 and differential gene expression in Cy3 versus Cy5 reactions.
Example 8
[0066] Usefulness of ΔTtsF412Y or ΔTtsF412YD426R Pol I in SnuPE, single nucleotide primer extension for investigation of target base on RNA (FIG. 11). Lane 1 is dNTP (G, A, T or C in panels A, B, C and D). Lane 2 is cold ddNTP. Lane 3 is a dye labeled ddNTP (linker arm length eleven carbon atoms). Lane 4 is a dye labeled ddNTP (linker arm length four carbon atoms). The dyes are from rhodamine class of FAM, R6G, TMR and Rox conjugated to ddG, ddA, ddT and ddC by either a 4-carbon or 11-carbon linkage.
[0067] The sequence of the template-primer that allowed for the examination of single nucleotide “G” incorporation is shown below.
CAGGCTGCCTATCAGAAGGTGGTGGCTGGTGTGGCCAATGCCCTGGCTCA 5′ 3′ mRNA (SEQ ID No. 13) TCTTCCACCACCGACCACACCGGTTACGG* CP-18 (3′-5′) (SEQ ID No. 14)
[0068] The sequence of the template-primer that allowed for the examination of single nucleotide “A” incorporation is shown below.
CAGGCTGCCTATCAGAAGGTGGTGGCTGGTGTGGCCAATGCCCTGGCTCA 5′ 3′ mRNA (SEQ ID No. 15) GTCTTCCACCACCGACCACACCGGTTACGG* CP-19 (3′-5′) (SEQ ID No. 16)
[0069] The sequence of the template-primer that allowed for the examination of single nucleotide “T” incorporation is shown below.
CAGGCTGCCTATCAGAAGGTGGTGGCTGGTGTGGCCAATGCCCTGGCTCA 5′ 3′ mRNA (SEQ ID No. 17) CTTCCACCACCGACCACACCGGTTACGG* CP-17 (3′-5′) (SEQ ID No. 18)
[0070] The sequence of the template-primer that allowed for the examination of single nucleotide “C” incorporation is shown below.
CAGGCTGCCTATCAGAAGGTGGTGGCTGGTGTGGCCAATGCCCTGGCTCA 5′ 3′ mRNA (SEQ TD No. 19) TTCCACCACCGACCACACCGGTTACGG* CP-16 (3′-5′) (SEQ ID No. 20)
[0071] Assays for measuring efficiency of dye-ddNTP or ddNTP by Tts variants were measured as below. A cocktail containing all reaction components except the ddNTP or dye-ddNTP was prepared as below. The reactions contained the following components. Tris, pH 8.0 (50 mM), KCl (40 mM), MgCl 2 , (3 mM) DTT (1 mM) dNTP or dye dNTP 0.2 uM (lanes 1, 2, 3 and 4), 5′ labeled p-33 primer (0.2 pimol), mRNA globin Template (100 ng), enzyme in a 10-ul reaction volume.
[0072] Template-primer annealing was accomplished by treating the components at 60 C. for 10 minutes followed by slowly cooling to 37 C. to allow for proper annealing. Reactions carried out for 10 min at appropriate temperature. Reactions were terminated by addition of 6 ul of formamide-stop solution. Samples were separated and analyzed on a 16% denaturing polyacrylamide gel. The wet gel was dried on Whatmann Filter paper and imaged using Autoradiography or PhosPhor Imager.
Example 9
[0073] Utility of Either ΔTts in RCA Reaction (FIG. 12)
[0074] Isothermal Rolling circle amplification reactions were performed as below. Template circular DNA was with primers 1 (Complementary to the circle) and 2 (same polarity as the circle), with all the components including the enzyme were combined as below. The reactions were performed at 55 C. for an hour and products analyzed following separation on 1% agarose gel. A 20-ul reaction contained, Tris pH 8.0 (50 uM), KCl (40 uM), MgCl2 (3 uM), DTT (1 uM) and dNTP (400 uM), primer 1 & 2 (1 uM, each), template and enzyme 20 units. Tth pol I reactions were done at 70 C. and Bst DNA pol reactions carried out at 55 C.
Example 10
[0075] Incorporation of Dye Labeled Nucleotide During DNA Dependent DNA Synthesis ΔTts, ΔTtsF412Y, ΔTtsF412YD426R (FIG. 13).
[0076] Primer extension was monitored using a defined DNA template-DNA primer.
[0077] In this experiment the relative efficiencies of incorporation of dye-CTP (Cy3.5-dCTP) was investigated. Three enzyme preparations were tested ΔTts, ΔTtsF412Y, and ΔTtsF412YD426R
[0078] Defined DNA shown below served as the template. A P-33 labeled primer (DNA 25 mer) was annealed to the template. Reactions were performed with varying concentrations of either Cy3.5-dCTP or dCTP alone. Inclusion of only one dNTP allowed incorporation of the next correct nucleotide alone. The sequence of the template-primer that allowed for the examination of single nucleotide “C” incorporation is shown below.
CAGGCTGCCTATCAGAAGGTGGTGGCTGGTGTGGCCAATGCCCTGGCTCA 5′ 3′ DNA (SEQ ID No. 21) TTCCACCACCGACCACACCGGTTACGG* CP-16 3′-5′ (SEQ hID No. 22)
[0079] Lanes 1, 2, 3, 4 and 5 contain 20, 2, 0.2, 0.02 and 0 uM dye-dCTP. Lane 5 has no enzyme, to show the integrity of the starting p-33 labeled primer. Quantification of the single nucleotide extension product is one way to tell if DR change in the enzyme led to any consequence. “P” indicates a radio labeled primer. “P+1” represents the elongated product by a single nucleotide or nucleotide analog. P+1 migrates slowly with the dye-dNTP conjugate. Note that the migration of Cy3.5-dCTP containing band travel slowly on the gel compared to dCMP extended products. Comparing Panel A, B and C, lanes 1 through 4 shows that the alteration of the amino acid back bone of the enzyme from D to R results in the improved efficiency of natural nucleotides. P+1 product is achieved between 10-100 fold less concentration of dye-dCTP with the enzyme having the DR change. Essentially, incorporation is achieved at a much lower concentration of dye-dNMP compared to the wild type enzyme. It is evident that the DR enzyme was able to incorporate Cy3.5-dCTP at concentrations as low as 0.2 uM or even lower. Compare this with the D enzyme (wild type), which exhibits relatively poor incorporation at these lower concentrations. And the results also show that this mutation dramatically reverses the decreased incorporation of dye-CMP seen with Tts F412Y in panel B. These observations demonstrate the utility of a DR variant in labeling during DNA template dependent synthesis as well.
Example 11
[0080] ΔTtsF412YD426R Performance in cDNA Labeling Using Cy3/Cy5-dCTP; Demonstration of Accurate Determination of Gene Expression Over a Wide Reaction Temperature Range (FIGS. 14 a and b ).
[0081] A 20 μl reaction Cy3 or Cy5 reaction had 1 μg of human skeletal muscle mRNA, oligo dT (25) and random nonamer primers and TtsFYDR polymerase enzyme in 1×reaction buffer (50 mM Tris, pH 8.0, 1 mM DDT, 40 mM KC, 100 uM dA,G and TTP and 50 um each of CTP and Cy3-dCTP or Cy5-dCTP depending on the reaction). Control mRNAs (APBiotech Inc.) of known sequence compositions were included in various concentrations to serve as dynamic range and gene expression ratio controls. Tts reactions were carried out at temperatures from 37, 42, 45, 50, 55, 60 and 65 degrees. For Superscript II, cDNA synthesis reactions were carried out at 42 C. (Life Technologies). Template RNA was hydrolyzed by alkali treatment and neutralized with HEPES.
[0082] Probes were purified using MultiScreen filters (Millipore) and quantified by spectrophotometry. Glass slides containing human cDNA gene targets were hybridized with equal amounts (30 pmol each) of Cy3 and Cy5 labeled cDNA probes. Slides were scanned using a GenePix® (Axon) scanner and quantified using ImageQuant software. A normalization factor of 2 (due to differences in the excitation efficiencies of Cy3 and Cy5) was applied to the observed ratio of raw flourescence signal. The figure illustrates precise determination of gene expression differences in Cy3 and Cy5 reactions. For example across all temperature ranges the normalized observed ratios were very close to the target ratios demonstrating the ability to accurately determine gene expression differences over a wide temperature range using ΔTtsF412YD426R.
Example 12
[0083] Protein Purification Protocol ΔTtsF412YD426R or ΔTtsD426R pol I Purification Scheme
[0084] The following was the protocol adapted for cells harvested from 1 L of LB media for initial enzyme evaluation studies (Typical yield of wet cells 4-6 g). E. coli cells harboring the expression vector were grown according to standard protocols as described in the original patent and harvested and kept frozen until ready for use. Cell lysis was carried out by adding 5 ml lysis buffer for every gram of wet cell paste (50 mM Tris pH 8.0, 1 mM EDTA, 50 mM NaCl, 10% Glycerol and containing 1 mg/ml lysozyme). Cells were left on ice for 40 minutes. Upon complete resuspension the cells were passed through a French Press at 15,000 PSI. After lysis, cell extract was treated at 70 C. for 10 to inactivate host enzymes. The extract was then clarified following centrifugation at 12,000 rpm for 30 minutes. The supernatant containing the enzyme fraction was then used for further purification.
[0085] The lysate was then loaded on to a Q-Sepharose HP column previously equilibrated with buffer A (Tris 50 mM (pH 7.5), EDTA 1 mM, NaCl 150 mM, 10% glycerol). The column was washed four times with buffer A. The flow rate of the buffer was 8- 10 ml per minute. This step selectively binds nucleic acid and the follow-through containing the enzyme is used in subsequent column. The flow-through sample was concentrated to small volume and removed of salt by tangential flow and diafiltration device to prepare for the next column. The sample was loaded on to a second Q-Sepharose HP column pre-equilibrated with buffer B (Tris 50 mM (pH 7.5), EDTA 1 mM, 10% glycerol). The column was washed with buffer B for three additional column volumes to remove any unbound proteins. The ΔTts F412YD426R pol I preparation was eluted by establishing a 0-30% gradient salt using NaCl. The eluted sample was dialyzed against buffer C (30 mM sodium phosphate, 30 mM sodium formate, 60 mM sodium acetate, 1 mM EDTA and 10% glycerol). The dialyzed sample was loaded on to a Resource S column previously equilibrated with buffer C. Column was washed with buffer C for three additional column volumes to remove unbound proteins. ΔTtsF412YD426R Pol I was eluted specifically using a 0-50% salt gradient using NaCl. This sample contained the purified enzyme preparation.
[0086] A similar purification protocol was employed for ΔTtsD426R Pol I.
1
32
1
872
PRT
Thermoanaerobacter thermohydrosulfuricus
1
Met Tyr Lys Phe Leu Ile Ile Asp Gly Ser Ser Leu Met Tyr Arg Ala
1 5 10 15
Tyr Tyr Ala Leu Pro Met Leu Thr Thr Ser Glu Gly Leu Pro Thr Asn
20 25 30
Ala Leu Tyr Gly Phe Thr Met Met Leu Ile Lys Leu Ile Glu Glu Glu
35 40 45
Lys Pro Asp Tyr Ile Ala Ile Ala Phe Asp Lys Lys Ala Pro Thr Phe
50 55 60
Arg His Lys Glu Tyr Gln Asp Tyr Lys Ala Thr Arg Gln Ala Met Pro
65 70 75 80
Glu Glu Leu Ala Glu Gln Val Asp Tyr Leu Lys Glu Ile Ile Asp Gly
85 90 95
Phe Asn Ile Lys Thr Leu Glu Leu Glu Gly Tyr Glu Ala Asp Asp Ile
100 105 110
Ile Gly Thr Ile Ser Lys Leu Ala Glu Glu Lys Gly Met Glu Val Leu
115 120 125
Val Val Thr Gly Asp Arg Asp Ala Leu Gln Leu Val Ser Asp Lys Val
130 135 140
Lys Ile Lys Ile Ser Lys Lys Gly Ile Thr Gln Met Glu Glu Phe Asp
145 150 155 160
Glu Lys Ala Ile Leu Glu Arg Tyr Gly Ile Thr Pro Gln Gln Phe Ile
165 170 175
Asp Leu Lys Gly Leu Met Gly Asp Lys Ser Asp Asn Ile Pro Gly Val
180 185 190
Pro Asn Ile Gly Glu Lys Thr Ala Ile Lys Leu Leu Lys Asp Phe Gly
195 200 205
Thr Ile Glu Asn Leu Ile Gln Asn Leu Ser Gln Leu Lys Gly Lys Ile
210 215 220
Lys Glu Asn Ile Glu Asn Asn Lys Glu Leu Ala Ile Met Ser Lys Arg
225 230 235 240
Leu Ala Thr Ile Lys Arg Asp Ile Pro Ile Glu Ile Asp Phe Glu Glu
245 250 255
Tyr Lys Val Lys Lys Phe Asn Glu Glu Lys Leu Leu Glu Leu Phe Asn
260 265 270
Lys Leu Glu Phe Phe Ser Leu Ile Asp Asn Ile Lys Lys Glu Ser Ser
275 280 285
Ile Glu Ile Val Asp Asn His Lys Val Glu Lys Trp Ser Lys Val Asp
290 295 300
Ile Lys Glu Leu Val Thr Leu Leu Gln Asp Asn Arg Asn Ile Ala Phe
305 310 315 320
Tyr Pro Leu Ile Tyr Glu Gly Glu Ile Lys Lys Ile Ala Phe Ser Phe
325 330 335
Gly Lys Asp Thr Val Tyr Ile Asp Val Phe Gln Thr Glu Asp Leu Lys
340 345 350
Glu Ile Phe Glu Lys Glu Asp Phe Glu Phe Thr Thr His Glu Ile Lys
355 360 365
Asp Phe Leu Val Arg Leu Ser Tyr Lys Gly Ile Glu Cys Lys Ser Lys
370 375 380
Tyr Ile Asp Thr Ala Val Met Ala Tyr Leu Leu Asn Pro Ser Glu Ser
385 390 395 400
Asn Tyr Asp Leu Asp Arg Val Leu Lys Lys Tyr Leu Lys Val Asp Val
405 410 415
Pro Ser Tyr Glu Gly Ile Phe Gly Lys Gly Arg Asp Lys Lys Lys Ile
420 425 430
Glu Glu Ile Asp Glu Asn Ile Leu Ala Asp Tyr Ile Cys Ser Arg Cys
435 440 445
Val Tyr Leu Phe Asp Leu Lys Glu Lys Leu Met Asn Phe Ile Glu Glu
450 455 460
Met Asp Met Lys Lys Leu Leu Leu Glu Ile Glu Met Pro Leu Val Glu
465 470 475 480
Val Leu Lys Ser Met Glu Val Ser Gly Phe Thr Leu Asp Lys Glu Val
485 490 495
Leu Lys Glu Leu Ser Gln Lys Ile Asp Asp Arg Ile Gly Glu Ile Leu
500 505 510
Asp Lys Ile Tyr Lys Glu Ala Gly Tyr Gln Phe Asn Val Asn Ser Pro
515 520 525
Lys Gln Leu Ser Glu Phe Leu Phe Glu Lys Leu Asn Leu Pro Val Ile
530 535 540
Lys Lys Thr Lys Thr Gly Tyr Ser Thr Asp Ser Glu Val Leu Glu Gln
545 550 555 560
Leu Val Pro Tyr Asn Asp Ile Val Ser Asp Ile Ile Glu Tyr Arg Gln
565 570 575
Leu Thr Lys Leu Lys Ser Thr Tyr Ile Asp Gly Phe Leu Pro Leu Met
580 585 590
Asp Glu Asn Asn Arg Val His Ser Asn Phe Lys Gln Met Val Thr Ala
595 600 605
Thr Gly Arg Ile Ser Ser Thr Glu Pro Asn Leu Gln Asn Ile Pro Ile
610 615 620
Arg Glu Glu Phe Gly Arg Gln Ile Arg Arg Ala Phe Ile Pro Arg Ser
625 630 635 640
Arg Asp Gly Tyr Ile Val Ser Ala Asp Tyr Ser Gln Ile Glu Leu Arg
645 650 655
Val Leu Ala His Val Ser Gly Asp Glu Lys Leu Ile Glu Ser Phe Met
660 665 670
Asn Asn Glu Asp Ile His Leu Arg Thr Ala Ser Glu Val Phe Lys Val
675 680 685
Pro Met Glu Lys Val Thr Pro Glu Met Arg Arg Ala Ala Lys Ala Val
690 695 700
Asn Phe Gly Ile Ile Tyr Gly Ile Ser Asp Tyr Gly Leu Ser Arg Asp
705 710 715 720
Leu Lys Ile Ser Arg Lys Glu Ala Lys Glu Tyr Ile Asn Asn Tyr Phe
725 730 735
Glu Arg Tyr Lys Gly Val Lys Asp Tyr Ile Glu Lys Ile Val Arg Phe
740 745 750
Ala Lys Glu Asn Gly Tyr Val Thr Thr Ile Met Asn Arg Arg Arg Tyr
755 760 765
Ile Pro Glu Ile Asn Ser Arg Asn Phe Thr Gln Arg Ser Gln Ala Glu
770 775 780
Arg Leu Ala Met Asn Ala Pro Ile Gln Gly Ser Ala Ala Asp Ile Ile
785 790 795 800
Lys Met Ala Met Val Lys Val Tyr Asn Asp Leu Lys Lys Leu Lys Leu
805 810 815
Lys Ser Lys Leu Ile Leu Gln Val His Asp Glu Leu Val Val Asp Thr
820 825 830
Tyr Lys Asp Glu Val Asp Ile Ile Lys Lys Ile Leu Lys Glu Asn Met
835 840 845
Glu Asn Val Val Gln Leu Lys Val Pro Leu Val Val Glu Ile Gly Val
850 855 860
Gly Pro Asn Trp Phe Leu Ala Lys
865 870
2
2619
DNA
Thermoanaerobacter thermohydrosulfuricus
2
atgtataaat ttttaataat tgatggaagt agcctcatgt acagagccta ttatgccttg 60
cccatgctta ctacaagtga gggattgcct acaaatgctc tgtatggttt tactatgatg 120
cttataaaac ttatcgagga ggaaaaacct gattacatag ctattgcttt tgacaaaaaa 180
gctcctactt ttagacacaa agaatatcaa gactacaaag ctacaagaca agctatgcct 240
gaagaacttg ctgaacaagt agactatttg aaagaaatta tagatggctt taatataaag 300
acattagaat tagaaggtta tgaagctgat gacattatag ggactatttc aaagctggca 360
gaggaaaaag gaatggaagt gcttgtagtt acaggagaca gagatgctct tcaattagtt 420
tcagataaag tgaagataaa aatttctaaa aagggtatta ctcagatgga agagtttgac 480
gaaaaggcta ttttagaaag gtatggaata actcctcagc agtttataga tttaaaaggg 540
cttatgggag ataaatctga taatatccct ggagtaccta atatagggga aaaaactgcg 600
attaagctat taaaggattt tggaacaatt gaaaatttaa tccaaaatct ttctcagctt 660
aaaggtaaaa taaaagaaaa tatagaaaac aataaagagt tagctataat gagtaagagg 720
cttgctacta taaaaagaga cattcccatt gagatagatt ttgaggagta taaagtaaaa 780
aaatttaatg aggagaagct tttagagctt tttaataaat tagaattctt tagtttaatt 840
gataacataa agaaagaaag tagcatagag attgtagata atcataaagt tgaaaaatgg 900
tcaaaagtag atataaaaga attagtaact ttgttgcaag ataacagaaa tattgctttt 960
tacccgttaa tttatgaagg ggaaataaaa aaaatagcct tttcttttgg aaaggatacg 1020
gtttatattg acgttttcca aacagaagat ttaaaggaga tttttgaaaa agaagatttt 1080
gaatttacaa cccatgaaat aaaggatttt ttagtgaggc tttcttataa aggaatagag 1140
tgtaaaagca agtacataga tactgctgta atggcttatc ttctgaatcc ttctgagtct 1200
aactatgact tagaccgtgt gctaaaaaaa tatttaaagg tagatgtgcc ttcttatgaa 1260
ggaatatttg gcaaaggtag ggataaaaag aaaattgaag agattgacga aaacatactt 1320
gctgattata tttgcagtag atgtgtgtat ctatttgatt taaaagaaaa gctgatgaat 1380
tttattgaag agatggatat gaaaaaactt ctattagaaa tagaaatgcc tcttgtagaa 1440
gttttaaaat caatggaggt aagtggtttt acattggata aagaagttct aaaagagctt 1500
tcacaaaaga tagatgatag aataggagaa atactagata aaatttataa agaggcagga 1560
tatcaattta atgtaaattc acctaagcaa ttaagtgaat ttttgtttga aaagttaaac 1620
ttaccagtaa taaagaaaac aaaaacagga tactctacgg attctgaagt tttggaacaa 1680
ttggttcctt ataatgatat tgtcagcgat ataatagagt atcggcaact tacaaaactt 1740
aaatctactt atatagatgg atttttgcct cttatggatg aaaacaatag agtacattct 1800
aattttaaac aaatggttac tgctacaggt agaataagca gcaccgagcc aaatctacaa 1860
aatataccta taagagaaga gtttggcaga caaattagaa gggcttttat tccgaggagt 1920
agagatggat atattgtttc agcagattat tctcagattg aactgagggt tttagcacat 1980
gtttcgggag atgaaaagct aatagaatct tttatgaata atgaagatat acatttaagg 2040
acagcttcgg aggtttttaa agttcctatg gaaaaagtta caccggagat gagaagagca 2100
gcaaaagccg taaattttgg cataatatat ggcataagcg attatgggct ttctcgagac 2160
cttaaaatat caagaaaaga agcaaaagag tacataaata attattttga aagatataaa 2220
ggagtaaaag attatattga aaaaatagta cgatttgcaa aagaaaatgg ctatgtgact 2280
acaataatga acagaaggag atatattcct gaaataaact caagaaattt tactcaaaga 2340
tcgcaggccg aaaggttagc aatgaatgct ccgatacagg gaagtgcggc tgatataata 2400
aaaatggcaa tggttaaggt atacaacgat ttaaaaaaat taaagcttaa gtctaagctt 2460
atattgcaag ttcatgacga gcttgtagtg gatacttata aggatgaagt agatatcata 2520
aaaaagatac ttaaagaaaa tatggaaaat gtagtgcaat taaaagttcc tctggttgtt 2580
gaaattggcg tagggcctaa ttggtttttg gccaagtga 2619
3
872
PRT
Thermoanaerobacter thermohydrosulfuricus
3
Met Tyr Lys Phe Leu Ile Ile Asp Gly Ser Ser Leu Met Tyr Arg Ala
1 5 10 15
Tyr Tyr Ala Leu Pro Met Leu Thr Thr Ser Glu Gly Leu Pro Thr Asn
20 25 30
Ala Leu Tyr Gly Phe Thr Met Met Leu Ile Lys Leu Ile Glu Glu Glu
35 40 45
Lys Pro Asp Tyr Ile Ala Ile Ala Phe Asp Lys Lys Ala Pro Thr Phe
50 55 60
Arg His Lys Glu Tyr Gln Asp Tyr Lys Ala Thr Arg Gln Ala Met Pro
65 70 75 80
Glu Glu Leu Ala Glu Gln Val Asp Tyr Leu Lys Glu Ile Ile Asp Gly
85 90 95
Phe Asn Ile Lys Thr Leu Glu Leu Glu Gly Tyr Glu Ala Asp Asp Ile
100 105 110
Ile Gly Thr Ile Ser Lys Leu Ala Glu Glu Lys Gly Met Glu Val Leu
115 120 125
Val Val Thr Gly Asp Arg Asp Ala Leu Gln Leu Val Ser Asp Lys Val
130 135 140
Lys Ile Lys Ile Ser Lys Lys Gly Ile Thr Gln Met Glu Glu Phe Asp
145 150 155 160
Glu Lys Ala Ile Leu Glu Arg Tyr Gly Ile Thr Pro Gln Gln Phe Ile
165 170 175
Asp Leu Lys Gly Leu Met Gly Asp Lys Ser Asp Asn Ile Pro Gly Val
180 185 190
Pro Asn Ile Gly Glu Lys Thr Ala Ile Lys Leu Leu Lys Asp Phe Gly
195 200 205
Thr Ile Glu Asn Leu Ile Gln Asn Leu Ser Gln Leu Lys Gly Lys Ile
210 215 220
Lys Glu Asn Ile Glu Asn Asn Lys Glu Leu Ala Ile Met Ser Lys Arg
225 230 235 240
Leu Ala Thr Ile Lys Arg Asp Ile Pro Ile Glu Ile Asp Phe Glu Glu
245 250 255
Tyr Lys Val Lys Lys Phe Asn Glu Glu Lys Leu Leu Glu Leu Phe Asn
260 265 270
Lys Leu Glu Phe Phe Ser Leu Ile Asp Asn Ile Lys Lys Glu Ser Ser
275 280 285
Ile Glu Ile Val Asp Asn His Lys Val Glu Lys Trp Ser Lys Val Asp
290 295 300
Ile Lys Glu Leu Val Thr Leu Leu Gln Asp Asn Arg Asn Ile Ala Phe
305 310 315 320
Tyr Pro Leu Ile Tyr Glu Gly Glu Ile Lys Lys Ile Ala Phe Ser Phe
325 330 335
Gly Lys Asp Thr Val Tyr Ile Asp Val Phe Gln Thr Glu Asp Leu Lys
340 345 350
Glu Ile Phe Glu Lys Glu Asp Phe Glu Phe Thr Thr His Glu Ile Lys
355 360 365
Asp Phe Leu Val Arg Leu Ser Tyr Lys Gly Ile Glu Cys Lys Ser Lys
370 375 380
Tyr Ile Asp Thr Ala Val Met Ala Tyr Leu Leu Asn Pro Ser Glu Ser
385 390 395 400
Asn Tyr Asp Leu Asp Arg Val Leu Lys Lys Tyr Leu Lys Val Asp Val
405 410 415
Pro Ser Tyr Glu Gly Ile Phe Gly Lys Gly Arg Asp Lys Lys Lys Ile
420 425 430
Glu Glu Ile Asp Glu Asn Ile Leu Ala Asp Tyr Ile Cys Ser Arg Cys
435 440 445
Val Tyr Leu Phe Asp Leu Lys Glu Lys Leu Met Asn Phe Ile Glu Glu
450 455 460
Met Asp Met Lys Lys Leu Leu Leu Glu Ile Glu Met Pro Leu Val Glu
465 470 475 480
Val Leu Lys Ser Met Glu Val Ser Gly Phe Thr Leu Asp Lys Glu Val
485 490 495
Leu Lys Glu Leu Ser Gln Lys Ile Asp Asp Arg Ile Gly Glu Ile Leu
500 505 510
Asp Lys Ile Tyr Lys Glu Ala Gly Tyr Gln Phe Asn Val Asn Ser Pro
515 520 525
Lys Gln Leu Ser Glu Phe Leu Phe Glu Lys Leu Asn Leu Pro Val Ile
530 535 540
Lys Lys Thr Lys Thr Gly Tyr Ser Thr Asp Ser Glu Val Leu Glu Gln
545 550 555 560
Leu Val Pro Tyr Asn Asp Ile Val Ser Asp Ile Ile Glu Tyr Arg Gln
565 570 575
Leu Thr Lys Leu Lys Ser Thr Tyr Ile Asp Gly Phe Leu Pro Leu Met
580 585 590
Asp Glu Asn Asn Arg Val His Ser Asn Phe Lys Gln Met Val Thr Ala
595 600 605
Thr Gly Arg Ile Ser Ser Thr Glu Pro Asn Leu Gln Asn Ile Pro Ile
610 615 620
Arg Glu Glu Phe Gly Arg Gln Ile Arg Arg Ala Phe Ile Pro Arg Ser
625 630 635 640
Arg Asp Gly Tyr Ile Val Ser Ala Asp Tyr Ser Gln Ile Glu Leu Arg
645 650 655
Val Leu Ala His Val Ser Gly Asp Glu Lys Leu Ile Glu Ser Phe Met
660 665 670
Asn Asn Glu Asp Ile His Leu Arg Thr Ala Ser Glu Val Phe Lys Val
675 680 685
Pro Met Glu Lys Val Thr Pro Glu Met Arg Arg Ala Ala Lys Ala Val
690 695 700
Asn Phe Gly Ile Ile Tyr Gly Ile Ser Asp Tyr Gly Leu Ser Arg Asp
705 710 715 720
Leu Lys Ile Ser Arg Lys Glu Ala Lys Glu Tyr Ile Asn Asn Tyr Phe
725 730 735
Glu Arg Tyr Lys Gly Val Lys Asp Tyr Ile Glu Lys Ile Val Arg Phe
740 745 750
Ala Lys Glu Asn Gly Tyr Val Thr Thr Ile Met Asn Arg Arg Arg Tyr
755 760 765
Ile Pro Glu Ile Asn Ser Arg Asn Phe Thr Gln Arg Ser Gln Ala Glu
770 775 780
Arg Leu Ala Met Asn Ala Pro Ile Gln Gly Ser Ala Ala Asp Ile Ile
785 790 795 800
Lys Met Ala Met Val Lys Val Tyr Asn Asp Leu Lys Lys Leu Lys Leu
805 810 815
Lys Ser Lys Leu Ile Leu Gln Val His Asp Glu Leu Val Val Asp Thr
820 825 830
Tyr Lys Asp Glu Val Asp Ile Ile Lys Lys Ile Leu Lys Glu Asn Met
835 840 845
Glu Asn Val Val Gln Leu Lys Val Pro Leu Val Val Glu Ile Gly Val
850 855 860
Gly Pro Asn Trp Phe Leu Ala Lys
865 870
4
1737
DNA
Thermoanaerobacter thermohydrosulfuricus
4
atgaaagttg aaaaatggtc aaaagtagat ataaaagaat tagtaacttt gttgcaagat 60
aacagaaata ttgcttttta cccgttaatt tatgaagggg aaataaaaaa aatagccttt 120
tcttttggaa aggatacggt ttatattgac gttttccaaa cagaagattt aaaggagatt 180
tttgaaaaag aagattttga atttacaacc catgaaataa aggatttttt agtgaggctt 240
tcttataaag gaatagagtg taaaagcaag tacatagata ctgctgtaat ggcttatctt 300
ctgaatcctt ctgagtctaa ctatgactta gaccgtgtgc taaaaaaata tttaaaggta 360
gatgtgcctt cttatgaagg aatatttggc aaaggtaggg ataaaaagaa aattgaagag 420
attgacgaaa acatacttgc tgattatatt tgcagtagat gtgtgtatct atttgattta 480
aaagaaaagc tgatgaattt tattgaagag atggatatga aaaaacttct attagaaata 540
gaaatgcctc ttgtagaagt tttaaaatca atggaggtaa gtggttttac attggataaa 600
gaagttctaa aagagctttc acaaaagata gatgatagaa taggagaaat actagataaa 660
atttataaag aggcaggata tcaatttaat gtaaattcac ctaagcaatt aagtgaattt 720
ttgtttgaaa agttaaactt accagtaata aagaaaacaa aaacaggata ctctacggat 780
tctgaagttt tggaacaatt ggttccttat aatgatattg tcagcgatat aatagagtat 840
cggcaactta caaaacttaa atctacttat atagatggat ttttgcctct tatggatgaa 900
aacaatagag tacattctaa ttttaaacaa atggttactg ctacaggtag aataagcagc 960
accgagccaa atctacaaaa tatacctata agagaagagt ttggcagaca aattagaagg 1020
gcttttattc cgaggagtag agatggatat attgtttcag cagattattc tcagattgaa 1080
ctgagggttt tagcacatgt ttcgggagat gaaaagctaa tagaatcttt tatgaataat 1140
gaagatatac atttaaggac agcttcggag gtttttaaag ttcctatgga aaaagttaca 1200
ccggagatga gaagagcagc aaaagccgta aattttggca taatatatgg cataagcgat 1260
tatgggcttt ctcgagacct taaaatatca agaaaagaag caaaagagta cataaataat 1320
tattttgaaa gatataaagg agtaaaagat tatattgaaa aaatagtacg atttgcaaaa 1380
gaaaatggct atgtgactac aataatgaac agaaggagat atattcctga aataaactca 1440
agaaatttta ctcaaagatc gcaggccgaa aggttagcaa tgaatgctcc gatacaggga 1500
agtgcggctg atataataaa aatggcaatg gttaaggtat acaacgattt aaaaaaatta 1560
aagcttaagt ctaagcttat attgcaagtt catgacgagc ttgtagtgga tacttataag 1620
gatgaagtag atatcataaa aaagatactt aaagaaaata tggaaaatgt agtgcaatta 1680
aaagttcctc tggttgttga aattggcgta gggcctaatt ggtttttggc caagtga 1737
5
872
PRT
Thermoanaerobacter thermohydrosulfuricus
5
Met Tyr Lys Phe Leu Ile Ile Asp Gly Ser Ser Leu Met Tyr Arg Ala
1 5 10 15
Tyr Tyr Ala Leu Pro Met Leu Thr Thr Ser Glu Gly Leu Pro Thr Asn
20 25 30
Ala Leu Tyr Gly Phe Thr Met Met Leu Ile Lys Leu Ile Glu Glu Glu
35 40 45
Lys Pro Asp Tyr Ile Ala Ile Ala Phe Asp Lys Lys Ala Pro Thr Phe
50 55 60
Arg His Lys Glu Tyr Gln Asp Tyr Lys Ala Thr Arg Gln Ala Met Pro
65 70 75 80
Glu Glu Leu Ala Glu Gln Val Asp Tyr Leu Lys Glu Ile Ile Asp Gly
85 90 95
Phe Asn Ile Lys Thr Leu Glu Leu Glu Gly Tyr Glu Ala Asp Asp Ile
100 105 110
Ile Gly Thr Ile Ser Lys Leu Ala Glu Glu Lys Gly Met Glu Val Leu
115 120 125
Val Val Thr Gly Asp Arg Asp Ala Leu Gln Leu Val Ser Asp Lys Val
130 135 140
Lys Ile Lys Ile Ser Lys Lys Gly Ile Thr Gln Met Glu Glu Phe Asp
145 150 155 160
Glu Lys Ala Ile Leu Glu Arg Tyr Gly Ile Thr Pro Gln Gln Phe Ile
165 170 175
Asp Leu Lys Gly Leu Met Gly Asp Lys Ser Asp Asn Ile Pro Gly Val
180 185 190
Pro Asn Ile Gly Glu Lys Thr Ala Ile Lys Leu Leu Lys Asp Phe Gly
195 200 205
Thr Ile Glu Asn Leu Ile Gln Asn Leu Ser Gln Leu Lys Gly Lys Ile
210 215 220
Lys Glu Asn Ile Glu Asn Asn Lys Glu Leu Ala Ile Met Ser Lys Arg
225 230 235 240
Leu Ala Thr Ile Lys Arg Asp Ile Pro Ile Glu Ile Asp Phe Glu Glu
245 250 255
Tyr Lys Val Lys Lys Phe Asn Glu Glu Lys Leu Leu Glu Leu Phe Asn
260 265 270
Lys Leu Glu Phe Phe Ser Leu Ile Asp Asn Ile Lys Lys Glu Ser Ser
275 280 285
Ile Glu Ile Val Asp Asn His Lys Val Glu Lys Trp Ser Lys Val Asp
290 295 300
Ile Lys Glu Leu Val Thr Leu Leu Gln Asp Asn Arg Asn Ile Ala Phe
305 310 315 320
Tyr Pro Leu Ile Tyr Glu Gly Glu Ile Lys Lys Ile Ala Phe Ser Phe
325 330 335
Gly Lys Asp Thr Val Tyr Ile Asp Val Phe Gln Thr Glu Asp Leu Lys
340 345 350
Glu Ile Phe Glu Lys Glu Asp Phe Glu Phe Thr Thr His Glu Ile Lys
355 360 365
Asp Phe Leu Val Arg Leu Ser Tyr Lys Gly Ile Glu Cys Lys Ser Lys
370 375 380
Tyr Ile Asp Thr Ala Val Met Ala Tyr Leu Leu Asn Pro Ser Glu Ser
385 390 395 400
Asn Tyr Asp Leu Asp Arg Val Leu Lys Lys Tyr Leu Lys Val Asp Val
405 410 415
Pro Ser Tyr Glu Gly Ile Phe Gly Lys Gly Arg Asp Lys Lys Lys Ile
420 425 430
Glu Glu Ile Asp Glu Asn Ile Leu Ala Asp Tyr Ile Cys Ser Arg Cys
435 440 445
Val Tyr Leu Phe Asp Leu Lys Glu Lys Leu Met Asn Phe Ile Glu Glu
450 455 460
Met Asp Met Lys Lys Leu Leu Leu Glu Ile Glu Met Pro Leu Val Glu
465 470 475 480
Val Leu Lys Ser Met Glu Val Ser Gly Phe Thr Leu Asp Lys Glu Val
485 490 495
Leu Lys Glu Leu Ser Gln Lys Ile Asp Asp Arg Ile Gly Glu Ile Leu
500 505 510
Asp Lys Ile Tyr Lys Glu Ala Gly Tyr Gln Phe Asn Val Asn Ser Pro
515 520 525
Lys Gln Leu Ser Glu Phe Leu Phe Glu Lys Leu Asn Leu Pro Val Ile
530 535 540
Lys Lys Thr Lys Thr Gly Tyr Ser Thr Asp Ser Glu Val Leu Glu Gln
545 550 555 560
Leu Val Pro Tyr Asn Asp Ile Val Ser Asp Ile Ile Glu Tyr Arg Gln
565 570 575
Leu Thr Lys Leu Lys Ser Thr Tyr Ile Asp Gly Phe Leu Pro Leu Met
580 585 590
Asp Glu Asn Asn Arg Val His Ser Asn Phe Lys Gln Met Val Thr Ala
595 600 605
Thr Gly Arg Ile Ser Ser Thr Glu Pro Asn Leu Gln Asn Ile Pro Ile
610 615 620
Arg Glu Glu Phe Gly Arg Gln Ile Arg Arg Ala Phe Ile Pro Arg Ser
625 630 635 640
Arg Asp Gly Tyr Ile Val Ser Ala Asp Tyr Ser Gln Ile Glu Leu Arg
645 650 655
Val Leu Ala His Val Ser Gly Asp Glu Lys Leu Ile Glu Ser Phe Met
660 665 670
Asn Asn Glu Asp Ile His Leu Arg Thr Ala Ser Glu Val Phe Lys Val
675 680 685
Pro Met Glu Lys Val Thr Pro Glu Met Arg Arg Ala Ala Lys Ala Val
690 695 700
Asn Tyr Gly Ile Ile Tyr Gly Ile Ser Asp Tyr Gly Leu Ser Arg Asp
705 710 715 720
Leu Lys Ile Ser Arg Lys Glu Ala Lys Glu Tyr Ile Asn Asn Tyr Phe
725 730 735
Glu Arg Tyr Lys Gly Val Lys Asp Tyr Ile Glu Lys Ile Val Arg Phe
740 745 750
Ala Lys Glu Asn Gly Tyr Val Thr Thr Ile Met Asn Arg Arg Arg Tyr
755 760 765
Ile Pro Glu Ile Asn Ser Arg Asn Phe Thr Gln Arg Ser Gln Ala Glu
770 775 780
Arg Leu Ala Met Asn Ala Pro Ile Gln Gly Ser Ala Ala Asp Ile Ile
785 790 795 800
Lys Met Ala Met Val Lys Val Tyr Asn Asp Leu Lys Lys Leu Lys Leu
805 810 815
Lys Ser Lys Leu Ile Leu Gln Val His Asp Glu Leu Val Val Asp Thr
820 825 830
Tyr Lys Asp Glu Val Asp Ile Ile Lys Lys Ile Leu Lys Glu Asn Met
835 840 845
Glu Asn Val Val Gln Leu Lys Val Pro Leu Val Val Glu Ile Gly Val
850 855 860
Gly Pro Asn Trp Phe Leu Ala Lys
865 870
6
1737
DNA
Thermoanaerobacter thermohydrosulfuricus
6
atgaaagttg aaaaatggtc aaaagtagat ataaaagaat tagtaacttt gttgcaagat 60
aacagaaata ttgcttttta cccgttaatt tatgaagggg aaataaaaaa aatagccttt 120
tcttttggaa aggatacggt ttatattgac gttttccaaa cagaagattt aaaggagatt 180
tttgaaaaag aagattttga atttacaacc catgaaataa aggatttttt agtgaggctt 240
tcttataaag gaatagagtg taaaagcaag tacatagata ctgctgtaat ggcttatctt 300
ctgaatcctt ctgagtctaa ctatgactta gaccgtgtgc taaaaaaata tttaaaggta 360
gatgtgcctt cttatgaagg aatatttggc aaaggtaggg ataaaaagaa aattgaagag 420
attgacgaaa acatacttgc tgattatatt tgcagtagat gtgtgtatct atttgattta 480
aaagaaaagc tgatgaattt tattgaagag atggatatga aaaaacttct attagaaata 540
gaaatgcctc ttgtagaagt tttaaaatca atggaggtaa gtggttttac attggataaa 600
gaagttctaa aagagctttc acaaaagata gatgatagaa taggagaaat actagataaa 660
atttataaag aggcaggata tcaatttaat gtaaattcac ctaagcaatt aagtgaattt 720
ttgtttgaaa agttaaactt accagtaata aagaaaacaa aaacaggata ctctacggat 780
tctgaagttt tggaacaatt ggttccttat aatgatattg tcagcgatat aatagagtat 840
cggcaactta caaaacttaa atctacttat atagatggat ttttgcctct tatggatgaa 900
aacaatagag tacattctaa ttttaaacaa atggttactg ctacaggtag aataagcagc 960
accgagccaa atctacaaaa tatacctata agagaagagt ttggcagaca aattagaagg 1020
gcttttattc cgaggagtag agatggatat attgtttcag cagattattc tcagattgaa 1080
ctgagggttt tagcacatgt ttcgggagat gaaaagctaa tagaatcttt tatgaataat 1140
gaagatatac atttaaggac agcttcggag gtttttaaag ttcctatgga aaaagttaca 1200
ccggagatga gaagagcagc aaaagccgta aattatggca taatatatgg cataagcgat 1260
tatgggcttt ctcgagacct taaaatatca agaaaagaag caaaagagta cataaataat 1320
tattttgaaa gatataaagg agtaaaagat tatattgaaa aaatagtacg atttgcaaaa 1380
gaaaatggct atgtgactac aataatgaac agaaggagat atattcctga aataaactca 1440
agaaatttta ctcaaagatc gcaggccgaa aggttagcaa tgaatgctcc gatacaggga 1500
agtgcggctg atataataaa aatggcaatg gttaaggtat acaacgattt aaaaaaatta 1560
aagcttaagt ctaagcttat attgcaagtt catgacgagc ttgtagtgga tacttataag 1620
gatgaagtag atatcataaa aaagatactt aaagaaaata tggaaaatgt agtgcaatta 1680
aaagttcctc tggttgttga aattggcgta gggcctaatt ggtttttggc caagtga 1737
7
872
PRT
Thermoanaerobacter thermohydrosulfuricus
7
Met Tyr Lys Phe Leu Ile Ile Asp Gly Ser Ser Leu Met Tyr Arg Ala
1 5 10 15
Tyr Tyr Ala Leu Pro Met Leu Thr Thr Ser Glu Gly Leu Pro Thr Asn
20 25 30
Ala Leu Tyr Gly Phe Thr Met Met Leu Ile Lys Leu Ile Glu Glu Glu
35 40 45
Lys Pro Asp Tyr Ile Ala Ile Ala Phe Asp Lys Lys Ala Pro Thr Phe
50 55 60
Arg His Lys Glu Tyr Gln Asp Tyr Lys Ala Thr Arg Gln Ala Met Pro
65 70 75 80
Glu Glu Leu Ala Glu Gln Val Asp Tyr Leu Lys Glu Ile Ile Asp Gly
85 90 95
Phe Asn Ile Lys Thr Leu Glu Leu Glu Gly Tyr Glu Ala Asp Asp Ile
100 105 110
Ile Gly Thr Ile Ser Lys Leu Ala Glu Glu Lys Gly Met Glu Val Leu
115 120 125
Val Val Thr Gly Asp Arg Asp Ala Leu Gln Leu Val Ser Asp Lys Val
130 135 140
Lys Ile Lys Ile Ser Lys Lys Gly Ile Thr Gln Met Glu Glu Phe Asp
145 150 155 160
Glu Lys Ala Ile Leu Glu Arg Tyr Gly Ile Thr Pro Gln Gln Phe Ile
165 170 175
Asp Leu Lys Gly Leu Met Gly Asp Lys Ser Asp Asn Ile Pro Gly Val
180 185 190
Pro Asn Ile Gly Glu Lys Thr Ala Ile Lys Leu Leu Lys Asp Phe Gly
195 200 205
Thr Ile Glu Asn Leu Ile Gln Asn Leu Ser Gln Leu Lys Gly Lys Ile
210 215 220
Lys Glu Asn Ile Glu Asn Asn Lys Glu Leu Ala Ile Met Ser Lys Arg
225 230 235 240
Leu Ala Thr Ile Lys Arg Asp Ile Pro Ile Glu Ile Asp Phe Glu Glu
245 250 255
Tyr Lys Val Lys Lys Phe Asn Glu Glu Lys Leu Leu Glu Leu Phe Asn
260 265 270
Lys Leu Glu Phe Phe Ser Leu Ile Asp Asn Ile Lys Lys Glu Ser Ser
275 280 285
Ile Glu Ile Val Asp Asn His Lys Val Glu Lys Trp Ser Lys Val Asp
290 295 300
Ile Lys Glu Leu Val Thr Leu Leu Gln Asp Asn Arg Asn Ile Ala Phe
305 310 315 320
Tyr Pro Leu Ile Tyr Glu Gly Glu Ile Lys Lys Ile Ala Phe Ser Phe
325 330 335
Gly Lys Asp Thr Val Tyr Ile Asp Val Phe Gln Thr Glu Asp Leu Lys
340 345 350
Glu Ile Phe Glu Lys Glu Asp Phe Glu Phe Thr Thr His Glu Ile Lys
355 360 365
Asp Phe Leu Val Arg Leu Ser Tyr Lys Gly Ile Glu Cys Lys Ser Lys
370 375 380
Tyr Ile Asp Thr Ala Val Met Ala Tyr Leu Leu Asn Pro Ser Glu Ser
385 390 395 400
Asn Tyr Asp Leu Asp Arg Val Leu Lys Lys Tyr Leu Lys Val Asp Val
405 410 415
Pro Ser Tyr Glu Gly Ile Phe Gly Lys Gly Arg Asp Lys Lys Lys Ile
420 425 430
Glu Glu Ile Asp Glu Asn Ile Leu Ala Asp Tyr Ile Cys Ser Arg Cys
435 440 445
Val Tyr Leu Phe Asp Leu Lys Glu Lys Leu Met Asn Phe Ile Glu Glu
450 455 460
Met Asp Met Lys Lys Leu Leu Leu Glu Ile Glu Met Pro Leu Val Glu
465 470 475 480
Val Leu Lys Ser Met Glu Val Ser Gly Phe Thr Leu Asp Lys Glu Val
485 490 495
Leu Lys Glu Leu Ser Gln Lys Ile Asp Asp Arg Ile Gly Glu Ile Leu
500 505 510
Asp Lys Ile Tyr Lys Glu Ala Gly Tyr Gln Phe Asn Val Asn Ser Pro
515 520 525
Lys Gln Leu Ser Glu Phe Leu Phe Glu Lys Leu Asn Leu Pro Val Ile
530 535 540
Lys Lys Thr Lys Thr Gly Tyr Ser Thr Asp Ser Glu Val Leu Glu Gln
545 550 555 560
Leu Val Pro Tyr Asn Asp Ile Val Ser Asp Ile Ile Glu Tyr Arg Gln
565 570 575
Leu Thr Lys Leu Lys Ser Thr Tyr Ile Asp Gly Phe Leu Pro Leu Met
580 585 590
Asp Glu Asn Asn Arg Val His Ser Asn Phe Lys Gln Met Val Thr Ala
595 600 605
Thr Gly Arg Ile Ser Ser Thr Glu Pro Asn Leu Gln Asn Ile Pro Ile
610 615 620
Arg Glu Glu Phe Gly Arg Gln Ile Arg Arg Ala Phe Ile Pro Arg Ser
625 630 635 640
Arg Asp Gly Tyr Ile Val Ser Ala Asp Tyr Ser Gln Ile Glu Leu Arg
645 650 655
Val Leu Ala His Val Ser Gly Asp Glu Lys Leu Ile Glu Ser Phe Met
660 665 670
Asn Asn Glu Asp Ile His Leu Arg Thr Ala Ser Glu Val Phe Lys Val
675 680 685
Pro Met Glu Lys Val Thr Pro Glu Met Arg Arg Ala Ala Lys Ala Val
690 695 700
Asn Tyr Gly Ile Ile Tyr Gly Ile Ser Asp Tyr Gly Leu Ser Arg Arg
705 710 715 720
Leu Lys Ile Ser Arg Lys Glu Ala Lys Glu Tyr Ile Asn Asn Tyr Phe
725 730 735
Glu Arg Tyr Lys Gly Val Lys Asp Tyr Ile Glu Lys Ile Val Arg Phe
740 745 750
Ala Lys Glu Asn Gly Tyr Val Thr Thr Ile Met Asn Arg Arg Arg Tyr
755 760 765
Ile Pro Glu Ile Asn Ser Arg Asn Phe Thr Gln Arg Ser Gln Ala Glu
770 775 780
Arg Leu Ala Met Asn Ala Pro Ile Gln Gly Ser Ala Ala Asp Ile Ile
785 790 795 800
Lys Met Ala Met Val Lys Val Tyr Asn Asp Leu Lys Lys Leu Lys Leu
805 810 815
Lys Ser Lys Leu Ile Leu Gln Val His Asp Glu Leu Val Val Asp Thr
820 825 830
Tyr Lys Asp Glu Val Asp Ile Ile Lys Lys Ile Leu Lys Glu Asn Met
835 840 845
Glu Asn Val Val Gln Leu Lys Val Pro Leu Val Val Glu Ile Gly Val
850 855 860
Gly Pro Asn Trp Phe Leu Ala Lys
865 870
8
872
PRT
Thermoanaerobacter thermohydrosulfuricus
8
Met Tyr Lys Phe Leu Ile Ile Asp Gly Ser Ser Leu Met Tyr Arg Ala
1 5 10 15
Tyr Tyr Ala Leu Pro Met Leu Thr Thr Ser Glu Gly Leu Pro Thr Asn
20 25 30
Ala Leu Tyr Gly Phe Thr Met Met Leu Ile Lys Leu Ile Glu Glu Glu
35 40 45
Lys Pro Asp Tyr Ile Ala Ile Ala Phe Asp Lys Lys Ala Pro Thr Phe
50 55 60
Arg His Lys Glu Tyr Gln Asp Tyr Lys Ala Thr Arg Gln Ala Met Pro
65 70 75 80
Glu Glu Leu Ala Glu Gln Val Asp Tyr Leu Lys Glu Ile Ile Asp Gly
85 90 95
Phe Asn Ile Lys Thr Leu Glu Leu Glu Gly Tyr Glu Ala Asp Asp Ile
100 105 110
Ile Gly Thr Ile Ser Lys Leu Ala Glu Glu Lys Gly Met Glu Val Leu
115 120 125
Val Val Thr Gly Asp Arg Asp Ala Leu Gln Leu Val Ser Asp Lys Val
130 135 140
Lys Ile Lys Ile Ser Lys Lys Gly Ile Thr Gln Met Glu Glu Phe Asp
145 150 155 160
Glu Lys Ala Ile Leu Glu Arg Tyr Gly Ile Thr Pro Gln Gln Phe Ile
165 170 175
Asp Leu Lys Gly Leu Met Gly Asp Lys Ser Asp Asn Ile Pro Gly Val
180 185 190
Pro Asn Ile Gly Glu Lys Thr Ala Ile Lys Leu Leu Lys Asp Phe Gly
195 200 205
Thr Ile Glu Asn Leu Ile Gln Asn Leu Ser Gln Leu Lys Gly Lys Ile
210 215 220
Lys Glu Asn Ile Glu Asn Asn Lys Glu Leu Ala Ile Met Ser Lys Arg
225 230 235 240
Leu Ala Thr Ile Lys Arg Asp Ile Pro Ile Glu Ile Asp Phe Glu Glu
245 250 255
Tyr Lys Val Lys Lys Phe Asn Glu Glu Lys Leu Leu Glu Leu Phe Asn
260 265 270
Lys Leu Glu Phe Phe Ser Leu Ile Asp Asn Ile Lys Lys Glu Ser Ser
275 280 285
Ile Glu Ile Val Asp Asn His Lys Val Glu Lys Trp Ser Lys Val Asp
290 295 300
Ile Lys Glu Leu Val Thr Leu Leu Gln Asp Asn Arg Asn Ile Ala Phe
305 310 315 320
Tyr Pro Leu Ile Tyr Glu Gly Glu Ile Lys Lys Ile Ala Phe Ser Phe
325 330 335
Gly Lys Asp Thr Val Tyr Ile Asp Val Phe Gln Thr Glu Asp Leu Lys
340 345 350
Glu Ile Phe Glu Lys Glu Asp Phe Glu Phe Thr Thr His Glu Ile Lys
355 360 365
Asp Phe Leu Val Arg Leu Ser Tyr Lys Gly Ile Glu Cys Lys Ser Lys
370 375 380
Tyr Ile Asp Thr Ala Val Met Ala Tyr Leu Leu Asn Pro Ser Glu Ser
385 390 395 400
Asn Tyr Asp Leu Asp Arg Val Leu Lys Lys Tyr Leu Lys Val Asp Val
405 410 415
Pro Ser Tyr Glu Gly Ile Phe Gly Lys Gly Arg Asp Lys Lys Lys Ile
420 425 430
Glu Glu Ile Asp Glu Asn Ile Leu Ala Asp Tyr Ile Cys Ser Arg Cys
435 440 445
Val Tyr Leu Phe Asp Leu Lys Glu Lys Leu Met Asn Phe Ile Glu Glu
450 455 460
Met Asp Met Lys Lys Leu Leu Leu Glu Ile Glu Met Pro Leu Val Glu
465 470 475 480
Val Leu Lys Ser Met Glu Val Ser Gly Phe Thr Leu Asp Lys Glu Val
485 490 495
Leu Lys Glu Leu Ser Gln Lys Ile Asp Asp Arg Ile Gly Glu Ile Leu
500 505 510
Asp Lys Ile Tyr Lys Glu Ala Gly Tyr Gln Phe Asn Val Asn Ser Pro
515 520 525
Lys Gln Leu Ser Glu Phe Leu Phe Glu Lys Leu Asn Leu Pro Val Ile
530 535 540
Lys Lys Thr Lys Thr Gly Tyr Ser Thr Asp Ser Glu Val Leu Glu Gln
545 550 555 560
Leu Val Pro Tyr Asn Asp Ile Val Ser Asp Ile Ile Glu Tyr Arg Gln
565 570 575
Leu Thr Lys Leu Lys Ser Thr Tyr Ile Asp Gly Phe Leu Pro Leu Met
580 585 590
Asp Glu Asn Asn Arg Val His Ser Asn Phe Lys Gln Met Val Thr Ala
595 600 605
Thr Gly Arg Ile Ser Ser Thr Glu Pro Asn Leu Gln Asn Ile Pro Ile
610 615 620
Arg Glu Glu Phe Gly Arg Gln Ile Arg Arg Ala Phe Ile Pro Arg Ser
625 630 635 640
Arg Asp Gly Tyr Ile Val Ser Ala Asp Tyr Ser Gln Ile Glu Leu Arg
645 650 655
Val Leu Ala His Val Ser Gly Asp Glu Lys Leu Ile Glu Ser Phe Met
660 665 670
Asn Asn Glu Asp Ile His Leu Arg Thr Ala Ser Glu Val Phe Lys Val
675 680 685
Pro Met Glu Lys Val Thr Pro Glu Met Arg Arg Ala Ala Lys Ala Val
690 695 700
Asn Phe Gly Ile Ile Tyr Gly Ile Ser Asp Tyr Gly Leu Ser Arg Asp
705 710 715 720
Leu Lys Ile Ser Arg Lys Glu Ala Lys Glu Tyr Ile Asn Asn Tyr Phe
725 730 735
Glu Arg Tyr Lys Gly Val Lys Asp Tyr Ile Glu Lys Ile Val Arg Phe
740 745 750
Ala Lys Glu Asn Gly Tyr Val Thr Thr Ile Met Asn Arg Arg Arg Tyr
755 760 765
Ile Pro Glu Ile Asn Ser Arg Asn Phe Thr Gln Arg Ser Gln Ala Glu
770 775 780
Arg Leu Ala Met Asn Ala Pro Ile Gln Gly Ser Ala Ala Asp Ile Ile
785 790 795 800
Lys Met Ala Met Val Lys Val Tyr Asn Asp Leu Lys Lys Leu Lys Leu
805 810 815
Lys Ser Lys Leu Ile Leu Gln Val His Asp Glu Leu Val Val Asp Thr
820 825 830
Tyr Lys Asp Glu Val Asp Ile Ile Lys Lys Ile Leu Lys Glu Asn Met
835 840 845
Glu Asn Val Val Gln Leu Lys Val Pro Leu Val Val Glu Ile Gly Val
850 855 860
Gly Pro Asn Trp Phe Leu Ala Lys
865 870
9
27
DNA
Artificial Sequence
Description of Artificial Sequence Primer
9
gggctttctc gacgccttaa aatatca 27
10
27
DNA
Artificial Sequence
Description of Artificial Sequence Primer
10
gccgtaaatt ttggcataat atatggc 27
11
50
DNA
Thermoanaerobacter thermohydrosulfuricus
11
caggctgcct atcagaaggt ggtggctggt gtggccaatg ccctggctca 50
12
27
DNA
Artificial Sequence
Description of Artificial Sequence Primer
12
ggcattggcc acaccagcca ccacctt 27
13
50
DNA
Thermoanaerobacter thermohydrosulfuricus
13
caggctgcct atcagaaggt ggtggctggt gtggccaatg ccctggctca 50
14
29
DNA
Artificial Sequence
Description of Artificial Sequence Primer
14
ggcattggcc acaccagcca ccaccttct 29
15
50
DNA
Thermoanaerobacter thermohydrosulfuricus
15
caggctgcct atcagaaggt ggtggctggt gtggccaatg ccctggctca 50
16
30
DNA
Artificial Sequence
Description of Artificial Sequence Primer
16
ggcattggcc acaccagcca ccaccttctg 30
17
50
DNA
Thermoanaerobacter thermohydrosulfuricus
17
caggctgcct atcagaaggt ggtggctggt gtggccaatg ccctggctca 50
18
28
DNA
Artificial Sequence
Description of Artificial Sequence Primer
18
ggcattggcc acaccagcca ccaccttc 28
19
50
DNA
Thermoanaerobacter thermohydrosulfuricus
19
caggctgcct atcagaaggt ggtggctggt gtggccaatg ccctggctca 50
20
27
DNA
Artificial Sequence
Description of Artificial Sequence Primer
20
ggcattggcc acaccagcca ccacctt 27
21
50
DNA
Thermoanaerobacter thermohydrosulfuricus
21
caggctgcct atcagaaggt ggtggctggt gtggccaatg ccctggctca 50
22
27
DNA
Artificial Sequence
Description of Artificial Sequence Primer
22
ggcattggcc acaccagcca ccacctt 27
23
40
PRT
Thermotoga maritima
23
Asn Val Lys Pro Glu Glu Val Thr Glu Glu Met Arg Arg Ala Gly Lys
1 5 10 15
Met Val Asn Phe Ser Ile Ile Tyr Gly Val Thr Pro Tyr Gly Leu Ser
20 25 30
Val Arg Leu Gly Val Pro Val Lys
35 40
24
40
PRT
Thermotoga neapolitana
24
Asn Val Lys Pro Glu Glu Val Asn Glu Glu Met Arg Arg Val Gly Lys
1 5 10 15
Met Val Asn Phe Ser Ile Ile Tyr Gly Val Thr Pro Tyr Gly Leu Ser
20 25 30
Val Arg Leu Gly Ile Pro Val Lys
35 40
25
40
PRT
Thermotoga subterranea
25
Gly Val Ser Glu Met Phe Val Ser Glu Gln Met Arg Arg Val Gly Lys
1 5 10 15
Met Val Asn Phe Ala Ile Ile Tyr Gly Val Ser Pro Tyr Gly Leu Ser
20 25 30
Lys Arg Ile Gly Leu Ser Val Ser
35 40
26
40
PRT
Escherichia coli
26
Gly Leu Pro Leu Glu Thr Val Thr Ser Glu Gln Arg Arg Ser Ala Lys
1 5 10 15
Ala Ile Asn Phe Gly Leu Ile Tyr Gly Met Ser Ala Phe Gly Leu Ala
20 25 30
Arg Gln Leu Asn Ile Pro Arg Lys
35 40
27
40
PRT
Thermus caldophilus
27
Gly Val Pro Pro Glu Ala Val Asp Pro Leu Met Arg Arg Ala Ala Lys
1 5 10 15
Thr Val Asn Phe Gly Val Leu Tyr Gly Met Ser Ala His Arg Leu Ser
20 25 30
Gln Glu Leu Ala Ile Pro Tyr Glu
35 40
28
40
PRT
Thermus filiformis
28
Gly Leu Asp Pro Ala Leu Val Asp Pro Lys Met Arg Arg Ala Ala Lys
1 5 10 15
Thr Val Asn Phe Gly Val Leu Tyr Gly Met Ser Ala His Arg Leu Ser
20 25 30
Gln Glu Leu Gly Ile Asp Tyr Lys
35 40
29
40
PRT
Thermus flavus
29
Gly Val Ser Pro Glu Gly Val Asp Pro Leu Met Arg Arg Ala Ala Lys
1 5 10 15
Thr Ile Asn Phe Gly Val Leu Tyr Gly Met Ser Ala His Arg Leu Ser
20 25 30
Gly Glu Leu Ser Ile Pro Tyr Glu
35 40
30
40
PRT
Thermus thermophilus
30
Gly Val Pro Pro Glu Ala Val Asp Pro Leu Met Arg Arg Ala Ala Lys
1 5 10 15
Thr Val Asn Phe Gly Val Leu Tyr Gly Met Ser Ala His Arg Leu Ser
20 25 30
Gln Glu Leu Ala Ile Pro Tyr Glu
35 40
31
40
PRT
Thermus aquaticus
31
Gly Val Pro Arg Glu Ala Val Asp Pro Leu Met Arg Arg Ala Ala Lys
1 5 10 15
Thr Ile Asn Phe Gly Val Leu Tyr Gly Met Ser Ala His Arg Leu Ser
20 25 30
Gln Glu Leu Ala Ile Pro Tyr Glu
35 40
32
40
PRT
Thermoanaerobacter thermohydrosulfuricus
32
Lys Val Pro Met Glu Lys Val Thr Pro Glu Met Arg Arg Ala Ala Lys
1 5 10 15
Ala Val Asn Phe Gly Ile Ile Tyr Gly Ile Ser Asp Tyr Gly Leu Ser
20 25 30
Arg Asp Leu Lys Ile Ser Arg Lys
35 40
|
An enzymatically active DNA polymerase or active fragment thereof, having at least 80% identity in its amino acid sequence to the DNA polymerase of Thermoanaerobacter thermohydrosulfuricus or fragment thereof, and having an amino acid alteration at position 720 in Tts Pol I or at position 426 in ΔTts Pol I or at a homologous position defined with respect to Tts DNA ploymerase I, having improved incorporation of nucleotide analogs and natural bases during DNA synthesis compared to unaltered enzyme.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application Ser. No. 62/189,097, filed Jul. 6, 2015, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates generally to tubular sleeve assemblies that provide thermal protection to an electronic object contained therein, and more particularly to a tubular sleeve assembly including a positioning member to maintain the assembly in a selectively releasable, fixed position about the electronic object contained therein.
2. Related Art
Sensors used in automotive applications, such as oxygen sensors which provide data to control engine operation and performance, are often mounted within the engine compartment of a vehicle where they are subject to harsh environmental elements including intense radiant heat, sources of abrasion and vibration during vehicle operation. Due to the harsh environmental elements, it is advantageous, and in many cases a requirement, to cover the relatively delicate, temperature sensitive sensors with protective sleeving in an effort to dampen vibration, provide protection against abrasion and shield radiant heat from reaching the sensor. Such sleeves generally comprise an elongated, cylindrical tube extending between opposite, open free ends. The cylindrical tube includes a damping inner layer of a nonwoven material, for example, polyester felt and a reflective outer layer comprising, for example, an aluminum foil layer laminated to an outer surface of the inner layer.
Due to the configuration of the aforementioned protective cylindrical sleeve and its harsh environment, it is typically difficult to assemble the sleeve about the sensor in a manner which allows the sleeve to be reliably secured and maintained in a desired position, while at the same time being readily removable for servicing of the sensor. Adhesives, tape and interference fits of an entirety of an inner surface of the cylindrical wall of the sleeve are used to effect attachment, but each of these mechanisms suffer various disadvantages. Adhesive attachment of the sleeve about the sensor, while generally secure, at least initially, permanently attaches the sleeve to the sensor, and thus, complicates servicing the sensor at a future time, and in addition, the adhesives can breakdown over time, thereby causing the sleeve to become dislodged from its desired protective position about the sensor. As a result, while generally effective in its initially bonded position, this method does not allow for easy removal of the sleeve for servicing of the sensor or reuse of the sleeve, as it requires destroying the bond joint of the adhesive. In addition, tape and interference fits can be unreliable in view of the heat and vibration encountered within the engine compartment, with tapes further being particularly burdensome to apply, and friction fits of an entirety of a sleeve inner surface suffer from variances in component tolerances, and difficulty of assembly, particularly if the interference is too great, or if the sleeve needs to traverse increased diameter obstacles along the path of assembly, such as a connector, for example. Further mechanisms are also known, such as using end caps made from separate materials from the tubular sleeve to position the sleeve; however, this method requires assembly of multiple components to one another in construction of the sleeve, thereby adding complexity and cost to the manufacture and assembly of the insulative sleeve.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention, a thermal sleeve for protecting an electronic member connected to a wiring harness is provided. The thermal sleeve includes a tubular heat-settable nonwoven inner layer having a generally cylindrical portion and an outer surface extending along a longitudinal central axis between opposite open ends. A reflective outer layer is disposed about the outer surface. At least one finger of the heat-settable nonwoven inner layer extends radially inwardly from the generally cylindrical portion. The at least one finger is heat-set to remain extended radially inwardly absent an externally applied force thereon. The at least one finger has a free end surrounding a through opening sized for receipt of the wiring harness.
In accordance with another aspect of the invention, the at least one finger includes a plurality of fingers.
In accordance with another aspect of the invention, the reflective outer layer can be spiral wrapped about the outer surface.
In accordance with another aspect of the invention, the reflective outer layer can be cigarette wrapped about the outer surface.
In accordance with another aspect of the invention, the reflective outer layer can be bonded to the outer surface.
In accordance with another aspect of the invention, the reflective outer layer extends over the at least one finger.
In accordance with another aspect of the invention, a solidified resinous material can be disposed on the nonwoven layer of the at least one finger.
In accordance with another aspect of the invention, a rigid layer of material can be bonded to the nonwoven layer of the at least one finger with the nonwoven layer being sandwiched between the reflective outer layer and the rigid layer of material.
In accordance with another aspect of the invention, the rigid layer of material can be formed of plastic.
In accordance with another aspect of the invention, the at least one finger can include a plurality of fingers and the rigid layer of material can be formed having a plurality of slits aligned with spaces between the fingers.
In accordance with another aspect of the invention, the at least one finger can be provided as a single finger having a plurality of overlapping folded regions.
In accordance with another aspect of the invention, a method of constructing a sleeve for protecting an electronic member connected to a wiring harness is provided. The method includes forming a tubular heat-settable nonwoven inner layer having a generally cylindrical portion and an outer surface extending along a longitudinal central axis between opposite open ends; fixing a reflective outer about the outer surface; and heat-setting at least one finger of the heat-settable nonwoven inner layer to extend radially inwardly from the cylindrical portion and establishing a through opening with a free end of the at least one finger for receipt of the wiring harness in an interference fit therein.
In accordance with another aspect of the invention, the method can further include forming a plurality of the at least one finger.
In accordance with another aspect of the invention, the method can further include forming the plurality fingers after the heat-setting step.
In accordance with another aspect of the invention, the method can further include forming the plurality fingers before the heat-setting step.
In accordance with another aspect of the invention, the method can further include establishing the through opening after heat-setting the at least one finger.
In accordance with another aspect of the invention, the method can further include disposing a resinous layer on the heat-settable nonwoven inner layer of the at least one finger.
In accordance with another aspect of the invention, the method can further include sandwiching the nonwoven layer of the at least one finger between the reflective outer layer and an inner rigid layer of material.
In accordance with another aspect of the invention, the method can further include forming the inner rigid layer of material having generally the same shape as the at least one finger.
In accordance with another aspect of the invention, the method can further include forming the inner rigid layer of material from plastic.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description of presently preferred embodiments and best mode, appended claims and accompanying drawings, in which:
FIG. 1A is a schematic side view of an assembly constructed in accordance with one aspect of the invention for protecting an electrical component;
FIG. 1B is a schematic side view of an assembly constructed in accordance with another aspect of the invention for protecting an electrical component;
FIG. 2A is a schematic isometric view of the thermal sleeve in accordance with one aspect of the invention of FIGS. 1A-1B shown in a partially constructed state;
FIG. 2B is a schematic isometric view of the thermal sleeve in accordance with another aspect of the invention of FIGS. 1A-1B shown in a partially constructed state;
FIG. 2C is a schematic isometric view of the thermal sleeve in accordance with another aspect of the invention of FIGS. 1A-1B shown in a partially constructed state;
FIG. 2D is a partial cross-sectional end view of the thermal sleeve in accordance with another aspect of the invention of FIGS. 1A-1B ;
FIG. 3 is an isometric view of the assembly looking generally along the arrow 2 of FIG. 1A ;
FIG. 3A is a partial cross-sectional side view of the thermal sleeve and elongate member of FIG. 3 showing a finger in phantom as it deflects axial during relative sliding movement between the thermal sleeve and elongate member;
FIG. 4 is an isometric end view of the thermal sleeve of FIG. 2A shown in a finished state;
FIG. 5A is an isometric view of an opposite end of the thermal sleeve of FIG. 4 ;
FIG. 5B is view similar to FIG. 5A of the thermal sleeve of FIG. 2B shown in a finished state;
FIG. 5C is view similar to FIG. 5A of the thermal sleeve of FIG. 2C shown in a finished state;
FIG. 6 is a cross-sectional view of a thermal sleeve constructed in accordance with yet another aspect of the invention; and
FIG. 7 is a plan view of a support member of the thermal sleeve of FIG. 6 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring in more detail to the drawings, FIGS. 1A-1B each show an assembly 10 , including a thermal protective sleeve including an integral position member, referred to hereafter simply as sleeve 12 , constructed in accordance with one aspect of the invention. The sleeve 12 is used, as least in part, to protect an electrical member 14 contained at least in part therein, such as sensor, against the effects of extreme radiant heat, abrasion, contamination and vibration. The sensor 14 is shown connected to an end of a wire harness 16 on an engine component 18 of a vehicle. The wire harness 16 can be provided as a bundle of exposed, insulated wires, or as a bundle of insulated wires enclosed within an outer protective sleeve, also referred to as tube 20 ( FIG. 1A ), 20 ′ ( FIG. 1B ), wherein the tube 20 , 20 ′ can have a corrugated or convolute outer surface 22 ( FIG. 1A ), or generally smooth outer surface 22 ′ ( FIG. 1B ), by way of example and without limitation. The sleeve 12 is configured for slidable movement along a longitudinal axis 24 of the wire harness 16 and tube 20 , 20 ′, if provided, to bring the sleeve 12 into its desired protective position about the sensor 14 . The sleeve 12 is further configured, via an integral positioning member made as one-piece of material with the sleeve 12 , as discussed in further detail below, to remain fixed in the protective position until desired to selectively slide the sleeve 12 away from its protective position, such as may be desired to service the sensor 14 . The sleeve 12 remains in its protective position during use via frictional engagement of the positioning member with the wires 16 or tube 20 , 20 ′ thereof, without need of secondary fasteners, such as tape or adhesives, and thus, assembly 10 is made simple and cost effective.
The sleeve 12 can be constructed having any desired length. The sleeve 12 , as shown in partially constructed embodiments of FIGS. 2A-2C and respective finished embodiments of FIGS. 5A-5C , has a nonwoven inner layer 26 and a reflective outer layer 28 . The inner layer 26 , in accordance with one aspect of the invention, is constructed of a heat-formable nonwoven material, and can be constructed having any desired wall thicknesses (t), depending on the nature and severity of heat exposure in the intended environment. The nonwoven material forming the inner layer 26 is formed including heat-settable fibers, such as heat-settable low melt fibers including either monofilaments and/or bi-component fibers. The low melt fibers can be mixed with standard thermoplastic fibers and/or fiberglass and/or natural fibers of hemp, jute, Keflex, or the like. The low melt fibers at least partially melt at a temperature lower than the remaining fibers when heat treated in a heat-setting process, whereupon the low melt fibers take on a solidified, heat-set configuration, thereby biasing the inner layer 26 and outer layer 28 to take on and retain a heat-set shape. If bi-component fibers are provided as low melt fibers, they can be provided having a core of a standard thermoplastic material, such as polyethylene terephthalate (PET), for example, with an outer sheath of polypropylene, polyethylene, or low melt polyester, for example. The standard thermoplastic fibers can be provided as any thermoplastic fiber, such as nylon or PET, for example, and act in part to provide the desired density and thickness (t) to the inner layer 26 , as desired, thereby providing additional thermal protection and rigidity to the sleeve 12 , while also being relatively inexpensive compared to the heat-settable fibers. Accordingly, the inner layer 26 is constructed having a suitable thickness (t) and density of mechanically intertwined, or otherwise bonded, non-woven standard thermoplastic fibers and low melt fibers to obtain the desired physical properties, depending on the application, while also being heat-settable into a desired shape.
The outer layer 28 is provided to reflect extreme radiant heat typical of an engine compartment, including temperatures generated by an exhaust system. The outer layer 28 can be formed of any suitable metal material, including a foil layer of aluminum or other desired metals. The foil outer layer 28 is relatively thin, thereby allowing the sleeve 12 to remain flexible over meandering paths and corners. The outer layer 28 is disposed about an outer surface 27 of the inner layer 26 , and can be spiral wrapped or cigarette wrapped about the nonwoven inner layer 26 , as desired. Any suitable, heat resistant adhesive can be used to facilitate bonding the outer layer 28 to the inner layer 26 , if desired.
In accordance with one presently preferred method of constructing the sleeve 12 , the nonwoven inner layer 26 is formed as a circumferentially continuous tubular wall, such as by being spiral wrapped, wherein the opposite edges can be brought into flush abutting relation with one another, thereby forming a butt joint 25 ( FIG. 2D ), to form smooth cylindrical outer and inner surfaces 27 , 29 extending between opposite open ends 30 , 32 . Then, the foil outer layer 28 can be wrapped about, in spiral or cigarette fashion, wherein the foil layer 28 can have opposite edges 33 , 35 brought into overlapping relation with one another, and can be mechanically fixed or bonded to the outer surface 27 of the inner layer 26 . Then, integral fingers 34 , also referred to as positioning members, end projections or locating and retention features, can be formed. In one embodiment, the fingers 34 can be formed in a cutting operation, whereupon some of the inner layer 26 and outer layer 28 is cut via any suitable cutting process to form slits or spaces 36 between adjacent fingers 34 . The spaces 36 , by way of example and without limitation, are shown as being generally V-shaped in FIG. 2A , though any desired shaped can be formed, thereby facilitating a subsequent folding operation, wherein the fingers 34 are folded radially inwardly to point generally toward one another and subsequently heat-set ( FIGS. 3, 4, 5A ). For example, as shown in another embodiment, rather than having V-shaped notches formed between adjacent fingers 34 , the slits 36 can be formed as straight or substantially straight slits ( FIG. 2B ), thereby forming generally rectangular fingers 34 , whereupon the fingers 34 can then be folded radially inwardly and subsequently heat-set ( FIG. 5B ). In this embodiment, it can be seen that the individual fingers 34 overlap one another along their radially extending edges, which can further act to provide enhanced protection to the sensor 14 . Further yet, rather than forming slits or otherwise cutting the sleeve wall to form individual fingers, a desired uncut length (L; FIG. 2C ) of an end region of the sleeve wall can be folded radially inwardly without first cutting or slitting, whereupon a single, circumferentially extending finger 34 can be formed, having accordion-like, folded overlapping regions as a result of not having slits ( FIG. 5C ). The folding operation can be performed by first disposing the tubular wall on a mandrel, and then folding the plurality of fingers 34 or single finger 34 , depending on the construction desired, over an end of the mandrel to bring the inner layer 26 into abutment with a generally flat end of the mandrel. Then, with the finger(s) 34 in the folded position, sufficient heat can be applied to the inner layer 26 to cause the inner layer, at least within the region including the finger(s) 34 , to take on a heat-set. The heat can be applied via a heatable mandrel and/or via an external source of heat. Accordingly, the finger(s) 34 are heat-shaped to remain or substantially remain in the “as folded” position, thereby providing the sleeve 12 with a remaining cylindrical portion extending from one end 30 to the location, a newly formed end 32 ′ of the cylindrical portion of the sleeve 12 , where the finger(s) 34 are bent radially inwardly. In accordance with another aspect of the invention, as shown in FIGS. 5A-5C , it is contemplated that a resinous material RM could be applied to the inner layer 26 , at least on the region of the inner layer 26 forming the fingers 34 , or to the entirety of the inner layer 26 , if desired, to facilitate providing the material of the fingers 34 with the desired stiffness, rigidity, resiliency and flexibility desired to optimally function as retention and retaining members. Further yet, as shown in FIGS. 6 and 7 , a separate support member in the form of a reinforcing layer of material, such as a plastic material, by way of example and without limitation, of desired thickness, resiliency and flexibility, such as a generally circular disc 38 , having through opening 40 sized and shaped similarly to an opening 42 formed by free ends 44 of the fingers 34 , could be bonded inside the sleeve 12 in abutment with the inner layer 26 of the fingers 34 . If provided, it is contemplated that the circular disc 38 would have slits 46 formed therein, as shown, with the slits 46 being arranged to register in axially and radially aligned relation with the slits or spaces 36 to allow the fingers 34 to remain resiliently flexible axially inwardly and axially outwardly along the axis 24 during assembly and removal of the sleeve 12 along the wire harness 16 . Of course, it should be recognized the slits 46 can be formed to take on the same shape as the slits 36 formed between the fingers 34 , as desired.
Upon completing the heat-setting operation, the sleeve 12 can be removed from the mandrel, wherein the one-piece sleeve 12 is provided, without having to fasten other components thereto in secondary operations, having a cylindrical portion extending from the open end 30 to an end location 32 ′ where the fingers 34 are folded radially inwardly, without need of secondary fasteners to join the fingers 34 to the sleeve 12 .
In use, the sleeve 12 can be easily slid over the wire harness 16 or tube 20 thereof, whereupon ends 44 of the fingers 34 engage and flex axially against the wires harness 16 or tube 20 . A predetermined amount of friction and interference between the finger end(s) 44 and the wire harness 16 or tube 20 can be provided by sizing the opening 42 bounded by the finger end(s) 44 in construction. As shown generally in FIG. 3A , with the fingers 34 being flexible and resilient, the fingers 34 are readily biased slightly axially via friction or interference with the wire harness 16 or tube 20 to flex axially away from the sleeve end 30 during installation and axially toward the sleeve end 30 during removal, such as may be required in service. If a tube 20 is provided as a corrugate tube ( FIG. 1A ), the fingers 34 can be biased to flex axially over annular crests C during installation and removal, and can be constructed to take on a predetermined thickness to be received within annular valleys V of the corrugations to facilitate maintaining the sleeve 12 in its intended “in use” position about the sensor 14 .
In FIG. 5C , a sleeve 112 constructed in accordance with another aspect of the invention is shown, wherein the same reference numerals, offset by a factor of 100 , are used to identify like features. The sleeve 112 has an inner layer 126 and an outer layer 128 constructed of the same materials discussed above for the sleeve 12 . In contrast to the sleeve 12 , a single finger 134 is folded radially inwardly, however, the free end 144 of the finger 134 , rather than forming an opening for receipt of the wires 16 or tube 20 as folded, can be formed via a subsequent cutting operation, such as die cutting via a circular punch, or any desired outer peripherally shaped punch. As such, the through opening 142 can be formed having a precisely sized and shaped configuration, whether circular or other configuration, thereby resulting in a precision amount of interference between a free end 144 of the finger 134 . As such, it should be recognized that a single, circumferentially continuous finger 134 can be folded radially inwardly, and then the opening 142 can be cut. Of course, this same mechanism for form the central opening can be used if a plurality of fingers 134 are formed and folded radially inwardly. If a single finger 134 is formed, the finger 134 has a plurality of overlapping folded regions 50 formed by the material of the finger 134 . Further yet, it is contemplated that upon folding the single finger 134 or plurality of fingers 134 radially inwardly, the finished shape of individual fingers 134 can be subsequently formed in a cutting operation, in addition to the cutting operation used in forming the opening 142 .
Obviously, in light of the above teachings, many modifications and variations of the present invention are possible. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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A thermal sleeve for protecting an electronic member connected to a wiring harness, assembly therewith and method of construction are provided. The thermal sleeve includes a tubular heat-settable nonwoven inner layer having a generally cylindrical portion and an outer surface extending along a longitudinal central axis between opposite open ends. A reflective outer layer is disposed about the outer surface. At least one finger of the heat-settable nonwoven inner layer extends radially inwardly from the generally cylindrical portion. The at least one finger is heat-set to remain extended radially inwardly absent an externally applied force thereon. The at least one finger has a free end surrounding a through opening sized for receipt of the wiring harness.
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PRIORITY CLAIM
This application claims the benefit of U.S. Patent Application No. 61/312,930, filed on Mar. 11, 2010, and which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a clothing folding apparatus. The present invention further relates to a system for folding and storing clothing.
BACKGROUND OF THE INVENTION
Clothing, whether stored on a shelf, in a closet, drawer, storage bin, suitcase or other container can be time consuming to arrange on the shelf or in the container in a neat manner. And even if arranged in a neat manner, it is difficult to maintain the clothing in a neat state. Items of clothing stored using conventional containers, or means of arranging clothing in the containers, can over time result in the stored clothing becoming messy, especially through removal of one or more items of clothing from the remaining stored items of clothing. This creates the need to reorganize the clothing, or otherwise it becomes more time consuming to locate specific items of clothing, and also the clothing that may have become disorganized can wrinkle. This can contribute to the need to re-launder or dry clean clothes or spend time or money pressing or steaming clothing. With certain, more fragile items of clothing, conventional clothing arranging and storing technologies can even result in damage to the clothing.
Another important consideration is space. In many residences, there is a need to optimize the use of storage space. This can help avoid the need to rent storage space for storing surplus and off-season items, which is a growing trend particularly in urban areas where space is at a premium. This leads to the No, this additional cost of renting the storage space and the significant time investment in organizing items both at the residence and at the storage space, and the trips between the storage space and the residence.
Conventional methods of arranging and storing method can be improved on to better utilize and improve access to available storage space. There is a need for a system and method that enables individuals to make better use of their existing storage space.
Using prior art systems and methods, individuals who organize their closets with a significant number of items of clothing can find it difficult to find particular items. When they are locating specific items of clothing they may disturb the organization of the items. This creates a need to re-organize the items of clothing which is time consuming.
Also, there is a growing demand for the “hotel aesthetic” in residences, including in closets for example, i.e. the sleek, modern, uncluttered look. The prior art systems and methods do not provide a cost effective and easy to use system and method for achieving and maintaining these objectives.
Certain prior art clothing folding and packing technologies are known.
For example, UK Patent Application No. 2,452,245 discloses a clothing folding and packing apparatus that is designed to enable clothing to be folded down the middle of clothing.
Another folding technology is disclosed in EP 0 7656617 A2, entitled “Frames for Packaging Articles”.
U.S. patent Publication Ser. No. 12/440,356 discloses a relatively complex clothing folding and packing apparatus.
There is a need therefore for an improved method of folding clothing, and arranging and storing folded clothing that is easy to use and inexpensive to manufacture. There is also need for a low cost folding guide that enables clothing, once folded, to remain in a folded state.
SUMMARY
In one aspect of the invention, a clothing folding system is provided comprising: one or more folding guides comprising: two or more sections or panels of substantially rigid material, and an intermediate area or web disposed between any two of the two or more sections of substantially rigid material, enabling the folding guide to be folded along the length of the intermediate area or web; wherein the one or more folding guides are sized so as to enable each folding guide to be used to place the folding guide in contact with an article of clothing, folding the article of clothing in a folding pattern defined by folding each intermediate area or web of the folding guide, wherein the folding guide remains folded within the article of clothing; and wherein the folding of multiple articles of clothing using the folding guides presents a plurality of articles of clothing that are substantially consistent in shape and size in their folded state, and such folded articles of clothing thereby are suitable to be stored in an organized arrangement.
In a particular aspect of the invention, the intermediate area is presented by a flexible web disposed between any two of the sections or panels.
In another aspect of the invention, a folding guide is provided comprising: two or more sections of substantially rigid material; and an intermediate area or web disposed between any two of the two or more sections or panels of substantially rigid material, enabling the folding guide to be folded along the length of the intermediate area or web; wherein the one or more folding guides are sized so as to enable each folding guide to be used to place the folding guide such that it is contact with an article of clothing, folding the article of clothing in a folding pattern defined by folding each flexible web of the folding guide, wherein the folding guide remains folded within the article of clothing; and wherein the folding of multiple articles of clothing with the assistance of the folding guides presents a plurality of articles of clothing that are substantially consistent in shape and size in their folded state, and such folded articles of clothing thereby are suitable to be stored in an organized arrangement.
In a still other aspect of the invention a folding method is provided comprising the steps of: (a) providing a plurality of folding guides that comprise two or more sections or panels of substantially rigid material, and an intermediate area or web disposed between any two of the two or more sections of substantially rigid material, enabling the folding guide to be folded along the length of the intermediate area or web; (b) placing the folding guide in contact with a first article of clothing, folding the article of clothing with the assistance of the folding guide to achieve a folding pattern defined by folding each intermediate area or web of the folding guide, wherein the folding guide remains folded within the article of clothing; (c) repeating step (b) for the remaining articles of clothing so as to present the plurality of articles of clothing such that in their folded state they have a substantially consistent shape and size; and (d) arranging the plurality of folded articles of clothing into an organized arrangement.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view of one embodiment of the clothing folding guide of the present invention.
FIG. 2 is a side perspective view of one embodiment of the clothing folding guide of the present invention, partially folded in.
FIG. 3 is a further side perspective view of one embodiment of the clothing folding guide of the present invention, showing the first panel folded into the second middle panel and the third panel also folded into the second middle panel.
FIG. 4 is partial perspective view illustrating a bendable portion of the clothing folding guide.
FIG. 5 is a top plan view of the clothing folding guide of the present invention.
FIG. 6 is an exploded view of the clothing folding guide of the present invention, in one particular embodiment thereof.
FIGS. 7 a through to 7 g illustrate the clothing folding method of the present invention, using the clothing folding apparatus of the present invention.
FIG. 8 is a perspective view illustrating an article of clothing folded with the folding guide.
FIGS. 9 a and 9 b illustrate particular embodiments of the present invention, showing the definition of the intermediate area or web on a single piece of material that forms the folding guide, indentation and scoring respectively.
FIG. 10 illustrates the vertical placement of articles of clothing including the folding guides, placed in a standard drawer.
FIG. 11 illustrates the vertical placement of articles of clothing including the folding guides, placed in a suitcase.
FIGS. 12 a and 12 b illustrate the way in which the present invention enables better utilization of existing storage space, and provides better visibility of stored items using the present invention.
In the drawings, embodiments of the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for the purpose of illustration and as an aid to understanding, and are not intended as a definition of the limits of the invention.
DETAILED DESCRIPTION
The present invention provides a clothing folding and storage system for improved storage of items of clothing. The clothing folding system includes a folding guide apparatus ( 10 ) or folding guide, and a series of steps for using the folding guide ( 10 ) to fold at least one clothing item, providing the folding method of the present invention. In one aspect of the invention, the item of clothing is folded around the folding guide ( 10 ), in accordance with the folding method of the present invention (explained below). Accordingly, with the present invention the item of clothing is stored with the folding guide apparatus folded within the item of clothing. This enables the item of clothing to maintain its folded position, and also that the material of the clothing continue to envelop the folding guide such that the clothing is maintained relatively wrinkle free in part because the material of most clothing tends to form around the sections or panels of the folding guide, as explained below, and by folding in accordance with the method of the invention maintain its position relative to the folding guide because of friction between the fabric of the clothing and the surfaces of the sections or panels. The present invention contemplates the use of materials or surface features that provide friction that is operable to provide this feature, which may depend on the nature of the fabric in part to avoid damage. This aspect assists in maintaining the ready to wear condition of clothing stored using the folding system.
The folding system, as explained below, may also include bags, boxes, hanging organizers, or other containers sized to receive one or more items folded using the folding guides.
FIG. 1 shows a perspective view of the folding guide ( 10 ), in one embodiment thereof. The folding guide ( 10 ) includes at least two sections or panels ( 12 ). In the embodiment of the folding guide ( 10 ) shown in FIG. 1 , three sections ( 12 ) are shown. Each section ( 12 ) is provided such that it is rigid or semi-rigid so as to be operable to maintain the fabric that is disposed adjacent to the surface of the section ( 12 ) in a flat position to prevent or reduce wrinkling, once the item of clothing is folded using the folding guide ( 10 ). Each section ( 12 ) defines a surface. The surface preferably includes or consists of a material that is effective to create friction between the section ( 12 ) in the mentioned fabric. This friction helps maintain the fabric in place relative to the surface, once the clothing item has been folded around the folding guide ( 10 ), in accordance with the method of the present invention.
In accordance with the folding method, in one aspect thereof, depending on the item of clothing or the fabric, the fabric may be folded over the folding guide ( 10 ) such that the fabric is formed around the folding guide so as to smooth the fabric and then maintain it in such smoothed position based on friction between the fabric and the material of the folding guide. It should be understood that certain fabric can be damaged when stretched, and so use of the folding guide ( 10 ) should avoid such damage by avoiding unnecessary or damaging stretching. Furthermore the friction referred to above is selected so as not to damage even relatively fragile fabric.
Disposed between any two adjacent sections ( 12 ) is a intermediate area or flexible area ( 14 ) or web that connects the adjacent sections ( 12 ). The web ( 14 ) is disposed so as to be relatively easy to bend so as to enable the use of the folding guide ( 10 ) in accordance with the method of the present invention, as shown in FIG. 2 and FIG. 3 for example. FIG. 4 is partial view that shows the features of the web.
FIG. 5 is a top plan view of the clothing folding guide of the present invention.
FIG. 6 is an exploded view of a particular embodiment of the folding guide ( 10 ), showing a possible internal structure of the folding guide ( 10 ) for providing the rigid sections ( 12 ) and the flexible webs ( 14 ). As shown in FIG. 6 , disposed in the interior of the folding guide ( 10 ) is a first rigid or semi-rigid panel and second rigid or semi-rigid panel, each of these corresponding to a section ( 12 ). For the web ( 14 ), a series of strips of rigid or semi-rigid material may be used. These components may then be fixed between two pieces of material sized to conform to the shape of the folding guide ( 10 ). These layers may be affixed to one another by stitching, stapling or other means of affixing, such as using a suitable adhesive, for example, so as to adhere the panels, strips, and two pieces of material, to form the folding guide ( 12 ). Contrast stitching may be used for example for decorative purposes.
It should be understood that other means of providing the sections ( 12 ) and means for bending between the sections ( 12 ), which in this embodiment are provided by means of the webs ( 14 ).
In a particular embodiment of the present invention the panels and strips are formed of cardboard having a suitable thickness. In a particular embodiment of the present invention, the folding guide is approximately 1.5 mms in thickness.
FIGS. 7 a to 7 f illustrate the method of the present invention, in one aspect thereof.
It should be noted that the system of the present invention comprises one or more folding guides of different sizes accommodating different items of clothing or items of clothing of different sizes. FIGS. 7 a to 7 f illustrate the folding of a t-shirt using the folding guide ( 10 ). A folding guide ( 10 ) of the same size can be used to fold dress shirts. Smaller folding guides ( 10 ) can be used for example to fold underwear or children's clothing for example, and larger folding guides ( 10 ) can be used for example for fabric and linens mentioned below, or for ties and scarves.
In one aspect of the invention, the folding guide ( 10 ) and related folding method enable a one or more items of clothing to be folded such that in their folded form they have a consistent shape and size, as shown in FIG. 7 g for example. The present invention, in one aspect thereof, involves arranging the folded items, adjacent to one another, in a general vertical orientation, optionally in a box or container or some other means for maintaining the items in such general vertical orientation. This enables one or more items of clothing folded using the folding guide apparatus to be arranged within a receptacle, such as a bin or other container, drawer, or suitcase, as further illustrated in FIG. 7 g . The receptacle can receive a larger number of items of clothing, folded in accordance with the method of the present invention in a more consistent and neat manner, than would normally be the case. This provides more efficient use of space, and the storage of items of clothing in a compact way that ensures that they remain wrinkle free.
It should be understood that, as shown in FIG. 8 , that the folding guide is designed so that when an article of clothing is folded using the folding guide, the folded article of clothing with the folding guide folded within the article of clothing, tends to be self-supporting. Consequently, clothing folded using the folding guide of the present invention may be organized on shelves in a way that enables the placement of the articles of clothing vertically in an organized and compact way.
FIGS. 9 a and 9 b illustrate particular embodiments of the present invention, showing the definition of the intermediate area or web on a single piece of material that forms the folding guide, indentation and scoring respectively. The treatment of the material in this way enables the formation of the intermediate areas or flexible webs, while conveniently enabling the use of a single piece of material.
The present invention contemplates the use of bags, boxes or other containers, sized to store particular number of items of clothing, folded in accordance with the present invention. An example of a box in accordance with the present invention is illustrated in FIG. 7 g . Such a box can be stored on a shelf for example, or in a drawer. The bag, box or container, sized for use as part of the system of the present invention, in a drawer for example can provide some structure that supports a plurality of folded shirts (for example) using the folding guide of the present invention. Inserts for suitcases are also contemplated, or in fact suitcase can be designed to receive items of clothing folded in accordance of the present invention. The containers or inserts for suitcases can be made of a variety of materials for example a fabric, arranged for the box or container to generally maintain its shape. The present invention also contemplates providing a variety of sizes and shapes of boxes, with a customer being given the option to order from a variety of sizes or boxes, shapes of boxes, colour etc., via a website or otherwise. The boxes can be made with or without a top portion, for example, a lid that can be fastened (for example using a ZIPPER™) to keep dust or odours from entering the box.
The boxes for example that are part of the system of the present invention, may include a pocket or insert for receiving labelling, for example to indicate the contents of the box.
In one particular aspect of the present invention, the system consists of one or more containers, specifically sized to store one or more items of clothing folded using the folding guide, with the folding guide disposed within such items of clothing, the items of clothing fitted within the one or more containers. The containers can be of different sizes, suited to store items of clothing of different sizes when folded, and organized in different arrangements within the containers. The system may include a specific number of folding guides, possibly of different sizes. The system may be accompanied with a guide to suggest the folding method, and also optimal arrangements of folded clothing within the containers, and different uses of the containers and folding guides for folding and storing different types of clothing. The present invention contemplates the creation of one or more guides or FAQs covering the use of the system, and the various aspects of the folding method, which can be distributed in print form, electronically on a storage medium accompanying the containers and folding guides, or which can be made available electronically via an Internet network.
It should be understood that modifications to the present invention are possible without departing from the scope of the invention. For example, instead of using a web, the thickness of the material used in forming the folding guide ( 10 ) can be modified so that it is thinner and easier to bend in the areas disposed between the sections ( 12 ). Different fabrics can be used for the two pieces of materials, for example, design fabric, fabric containing licensed material, etc. The present invention can be used to fold any items of clothing where it would be desirable to fold them uniformly, and consequently enable storage in an efficient and neat manner, and making it easier to see and retrieve items stored in accordance with the present invention. The number of sections can be altered, adding more sections as many times as it is desirable to fold particular items of clothing.
The folding guide can be used, or a modified version that incorporates the elements and functionality described to provide a folding guide that acts as a pant folder, folder for fabrics, linens (whether towels, table linens, bed linens) etc. It should be understood that the web ( 14 ) is generally sized to conform to the thickness of the article made of fabric that is folded using the folding guide. For example, the folding guide ( 10 ) for towels or fabric will generally have a wider web ( 14 ) to accommodate the larger bend or curve of the fabric that will be present after the towel or fabric has been folded.
Folding of items of clothing in accordance with the present invention, and storing of the clothing in an organized and compressed form can result in saving 20-30% of space, in part because of the uniform size. The items of clothing or articles of fabric, organized using the present invention, and placed in a container as described above can be placed on higher shelves or further back on deeper shelves, thereby providing better use of such space while still making it relatively easy to access the stored items without the need to re-organize items when one or more of the items are removed, as explained above.
The present invention presents the opportunity to avoid the cost and time involved in accessing storage space and the back and forth trips between the residence and the storage space. The present invention also enables much more efficient retrieval of items and less need to re-organize remaining items after one or more of them have been retrieved. The folded items, in accordance with the present invention, enable an individual to easily see and feel what the folded items are, making searching for items much easier.
Use of the present invention provides a far more organized visual impression for stored items, resulting in satisfaction from the greater visual order and reduction in frustration that normally results from seeing chaotically stored items or trying to access specific items using prior art technologies.
The present invention contemplates the use of ancillary items such as for example collar pieces to maintain a shirt collar in place. The collar piece may consist of a semi-rigid band that is sized to fit under the collar and which can be attached at its ends to form a loop around the collar.
It is contemplated that instructions may be printed on one or more panels of the folding guide ( 10 ). The folding guide could be scented, and could include an anti-humidity layer.
The present invention, with the items arranged in a container as described above enables the better utilization of storage space (for example higher shelves, or back portions of shelves) while still ensuring that items are relatively easy to access.
It is noted that the system, apparatus, and method of the present invention improves the transportation of clothing and other items made of fabric by enabling these items to be maintained in a neatly folded state. For example, a container in accordance with the present invention, sized to fit within a suitcase or gym bag, receives one or more items folded using the folding guides, can be transported inside the suitcase or gym bag. For business travellers especially, this enables items that would otherwise require pressing or ironing to be kept in a neat state where such ironing or pressing is no longer required.
As a specific feature of the folding guides ( 10 ) of the present invention, the edges may be rounded, as shown in the Figs., in order to help avoid creases.
It should be understood that to organize a defined list of clothing items, it may by useful to use a range of folding guides of different sizes, and particular numbers of folding guides of specific size. The present invention contemplates the use of a calculator that, based on input regarding the clothing items, suggests possible arrangements of the clothing/folding guides for efficient storage configuration of the clothing using particular numbers and sizes of folding guides of the present invention. The calculator may be implemented using a web application component, and may be used to deliver the calculation functionality via operation of an associated website. The web application component may be implemented as part of a web application or computer program, provided in a manner known to those skilled in the art, and loaded onto or provided to a web server. A user may enter the number of clothing items in specific categories; and particular aspects of the storage space available. The calculator is operable to calculate the number of different items of the folding system to organize the specific clothing items, which may be included in an online order.
FIG. 10 illustrates the vertical placement of articles of clothing including the folding guides, placed in a standard drawer. As explained above, the present invention enables the vertical placement of articles of clothing, which provides efficient use of the storage space and access to individual articles of clothing in a way that the remaining articles of clothing remain in place.
FIG. 11 illustrates the vertical placement of articles of clothing including the folding guides, placed in a suitcase. The use of the present invention in suitcases also enables ready access to items of clothing. The items of clothing, placed vertically, can be removed from the suitcase without significant disturbance of the other items, thereby obviating the need to re-organize the other items after removal of one or more items.
FIGS. 12 a and 12 b illustrate the way in which the present invention enables better utilization of existing storage space, and also provide increased visibility of clothing inventory. FIG. 12 b illustrates the prior art approach, and shows that in most drawers for example, based on their dimensions, and the size of clothing such as shirts, these items are folded in two such that the back portion shown in FIG. 12 b remains unused. In contrast, FIG. 12 a shows that the vertical placement of items of clothing, for example in a drawer, enables the arrangement of the items of clothing in a more efficient manner. The drawer used for this comparison is a standard drawer (from one of the most popular Ikea dressers) with the following interior measurements—width: 28″, depth 16¾″, height 6¼″. Using the folding guides of the present invention, 34 tops may be stored in such a standard drawer, as shown in FIG. 12 a . Using the traditional folding and arrangement method shown in FIG. 12 b , only 24 tops can be stored because of the unused space.
It will be appreciated by those skilled in the art that other variations of the embodiments described herein may also be practiced without departing from the scope of the invention. Other modifications are therefore possible.
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A clothing folding system is provided comprising: one or more folding guides comprising: two or more sections of substantially rigid material: and a flexible web disposed between any two of the two or more sections of substantially rigid material, enabling the folding guide to be folded along the length of the flexible web: wherein the one or more folding guides are sized so as to enable each folding guide to be used to place the folding guide in contact with an article of clothing, folding the article of clothing in a folding pattern defined by folding each flexible web of the folding guide, wherein the folding guide remains folded within the article of clothing: and wherein the folding of multiple articles of clothing using the folding guides presents a plurality of articles of clothing that are substantially consistent in shape and size in their folded state, and such folded articles of clothing thereby are suitable to be stored in a sustainable organized arrangement. A specific structure for the folding guide is provided as well as a related folding method for clothing, using the folding guide. A related method is provided for folding articles of clothing. The system may include a computer implemented system to enable a user to provide as input one or more parameters for articles of clothing and available storage spaces: the system generating a recommended set of folding guide requirements to meet the user's input parameters.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to retrieval of downhole in-place or loose apparatus on materials used in the operations of oil and gas wells. More specifically, the invention pertains to an assembly and method which offers the capability for retrieval of fish, such as electric submersible pumps, or the like, for maintenance, rebuilding, and later re-use. Fish is a term commonly used in the oil and gas industry for loose and in-place down-hole items, such as tools, devices or other items which are to be removed from the well.
Though a number of prior art fishing tools can be located, the present invention is designed so as to remove fish from a cased hole where there exists too little clearance between the outer diameter (OD) of the fish and the inner diameter (ID) of the oil well casing. Consequently, there has existed a long-felt unresolved need for a device which will retrieve fish where limited clearance in the oil well casing is a necessary consideration. It is also necessary for the tool to retrieve the fish by an external catch eliminating or minimizing any damage to the fish while still having enough strength and power to pull the fish from the well.
The principal disadvantage of other inventions employed for removing fish from down-hole locations, such as spear-type devices, is that the fish cannot be re-used after removal from the well. In addition, the prior art includes devices which are not capable of functioning where there is limited clearance between the well casing and the fish. Furthermore, some of the devices, including conventional overshots or other external catch retrieval devices, can not lift and remove heavier, difficult to grasp items, such as electric submersible pumps without damage.
2. Related Art
The presently known prior art includes the following: Miller U.S. Pat. No. 1,785,590, McGill U.S. Pat. No. 2,745,693, Crowe U.S. Pat. No. 2,893,491, Lee U.S. Pat. No. 3,108,637, Timmons U.S. Pat. No. 3,380,528, Brown U.S. Pat. No. 3,638,988, Keller U.S. Pat. No. 4,061,389, Taylor U.S. Pat. No. 4,093,294, Taylor U.S. Pat. No. 4,232,894, Taylor U.S. Pat. No. 4,284,137, and Taylor Pat. No. 5,022,473.
OBJECTS OF THE INVENTION
An object of the present invention is to provide an assembly which can be employed for the retrieval of fish which produces minimal or no damage to the fish.
Another object of the invention is to provide an assembly which can be employed for the retrieval of fish which utilizes an expandable sleeved grapple.
Another object of the invention is to provide an assembly which can be employed for the retrieval of fish which have an outside diameter nearly the same dimension as the inside diameter of the well casing.
SUMMARY OF THE INVENTION
The foregoing and other objects and advantages of the invention are provided in an assembly and method for use in a well fishing and retrieval operating string which provides expandable capability for retrieval of fish, including down-hole in-place tools or other items, such as electric submersible pumps. The assembly includes a top sub, a sleeve with integral keys, a grapple element having upper and lower notches or J-latches which are located on opposite ends of connecting slots, and grapple fingers. When the assembly is run down the well, the grapple element is extended and held in the extended position by having the keys positioned in contact with the upper J-latches of the grapple element. The assembly is adapted to allow expansion of the grapple fingers around the fish by the application of weight to the operating string until the fish is fully engaged. When the assembly is to be removed from the well, the keys are released from contact with the upper J-latches by rotating the string 1/8th turn, thereby allowing the keys to slide down the correcting slots and the sleeve to slide down and completely enclose the grapple. While weight is continuously applied to the string, the assembly is rotated 1/8th turn in the opposite direction, engaging the keys with the lower J-latches, and the assembly is prepared for lifting the fish from the well.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an exploded isometric of the well fishing grapple.
FIG. 2 shows a cross-section view of the well fishing grapple.
FIG. 3 shows an elevation view of the grapple as it would appear inside a well casing.
FIG. 4 shows a cross-section view of the grapple after it makes initial contact with the fish.
FIG. 5 shows a cross-section view of the grapple with the fingers fully expanded around the fish.
FIG. 6 shows a cross-section view of the grapple after the fish has been fully engaged by the grapple.
FIG. 7 shows a cross-section view of the grapple with the keys in direct contact with the lower J-latch.
FIG. 8 shows a cross-section view of the grapple being removed from the well with the fish.
FIG. 9 shows a cross-section view of the grapple viewed as indicated through FIG. 4.
FIG. 10 shows a cross-section view of the grapple viewed as indicated through FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an exploded isometric of the preferred embodiment of the well fishing grapple, 10, that consists of four component parts which are a top sub, 11, a sleeve, 12, a grapple element, 13, and a grapple retainer, 14. Top sub, 11, threadedly engages with sleeve, 12, by virtue of internal threads, 11a, on top sub, 11, and external threads, 12a, of sleeve, 12. The grapple retainer, 14, threadedly engages grapple, 13, by virtue of internal threads, 14a, and external threads, 13a.
The grapple element, 13, is shown in an elevation view in FIG. 2. As indicated in FIG. 2, keys, 15, located inside the sleeve, 12, (not shown in FIG. 2) and spaced 120 degrees circumferentially apart, are shown (in phantom lines) in contact, or close proximity, to the corresponding notches or J-latches, 16, located at the upper and lower portion or neck of the grapple element, 13. As shown in FIG. 2, the keys, 15, slide up and down through slots, 18, also indicated in FIG. 2. When the fishing grapple, 10, is lowered into the well casing, the keys, 15, are in direct contact with the upper J-latches, 16. When the fishing grapple, 10, is removed from the well casing, the keys, 15, are in direct contact with the lower J-latches, 17.
The upper J-latches, 16, will ensure the grapple element, 13, will remain extended when the fishing grapple, 10, is lowered into the well casing, 50. The lower J-latches, 17, ensure the grapple element, 13, will remain inside the sleeve, 12, when it is removed from the well casing, 50. The well fishing grapple, 10, is assembled as indicated in FIG. 1; details of assembly will be described hereinafter.
As indicated in FIG. 1, the top sub, 11, has internal threads, 11a, at the lower portion; the sleeve, 12, has outside threads, 12a, at the upper portion; the grapple element, 13, has outside threads, 13a, at the upper portion; and the grapple retainer, 14, has internal threads, 14a, and is open at both ends, 60. Although it is not shown in FIG. 1, the top sub, 11, has internal threads at the upper portion for connection to the fishing string. (See FIG. 4)
Referring again to FIG. 1, the grapple element, 13, has an inwardly projecting grip, 19, which has sloped surfaces at the upper and lower portion of the grip, 19a and b, and a flat surface in the middle portion, 19c; the grip, 19, is located at the lower portion and inside the grapple element, 13. The grapple element, 13, incorporates at the upper end an external threaded service, 13a, as discussed above, which corresponds to internal threaded service, 14a, of the grapple retainer 14. The latch section, 8, incorporates a plurality, in this case 3, of latch slots, 18, which correspond to sleeve keys, 15, not shown. Each slot has an upper J-latch notch, 16, and lower J-latch notch, 17. The lower grapple section, 7, of grapple element, 13, utilizes a plurality of grapple fingers, 21, which are separated by a plurality of longitudinal slits, 21a.
FIG. 3 shows an elevation view of the grapple tool, 10, as it would appear inside a well casing, 50. The grapple tool, 10, is shown approaching the fish, as for example a submersible pump, 20, of the type shown. As indicated in FIG. 3, a cross-section view of the grapple tool, 10, is shown in FIG. 10 as it would appear looking upward from the location of the fish, 20, before the grapple fingers, 21, make contact with the fish, 20.
FIG. 4 shows a cross-section view of the grapple, 10, after it makes initial contact with the fish, 20. Expansion of the lower portion, or fingers, 21, of the grapple element, 13, around the fish, 20, resulting from external application of weight to the well string, 30, is shown in the initial stage of expansion. As indicated in FIG. 4, a cross-section view of the well fishing grapple, 10, is shown in FIG. 9 as it would appear at that point, after the grapple makes contact with the fish, 20.
Weight is continuously applied externally to the well string, transmitted through the top sub, 11, then to the sleeve, 12, on to the keys, 15, in contact with the upper J-latches, 16, then through the grapple element, 13, which forces the fingers, 21, with the grip, 19, to expand around the fish, 20. FIG. 5 shows a cross-section view of the grapple, 10, with the fingers, 21, fully expanded around the fish, 20.
FIG. 6 shows a cross-section view of the grapple, 10, after the fish, 20, has been fully engaged by the grapple, 10, resulting from the continuous application of weight to the well string.
FIG. 7 shows a cross-section view of the grapple, 10, with the keys, 15, in direct contact with the lower J-latches, 17. This configuration is maintained while the grapple, 10, and the fish, 20, are pulled out of the well casing, 50, as shown in FIG. 8.
It is to be understood that the form of the invention herein shown and described is to be taken as a preferred example, and that numerous variations will be obvious to those skilled in the art in the light of the teachings of this specification, without departing from the scope of the hereinafter claimed subject matter.
OPERATION OF THE PREFERRED EMBODIMENT
Assembly of the fishing grapple, 10, as indicated in FIG. 1, is as follows. The grapple element, 13, is stood upright on a flat surface (with the threaded portion up). The sleeve, 12, is slid over the grapple element, 13, such that the sleeve's integral keys, 15, are positioned into the slots on the upper portion of the grapple element, 13, allowing the sleeve, 12, to slide all the way down. The threads on the upper portion of the grapple element, 13, are thereby exposed above the top of the sleeve, 12, permitting the grapple retainer, 14, to be screwed on to the grapple element, 13. The top sub, 11, is placed over the grapple element, 13, and retainer, 14, until it engages the threads on the upper portion of the sleeve, 12; the top sub, 11, is screwed on to the grapple element, 13, until it is hand tight. Further tightening, as required, may be accomplished by placing the assembled fishing grapple, 10, in a vise, clamping on the upper portion or neck of the top sub, 11. For tightening with a wrench, the wrench should be placed on the sleeve, 12, at the point where the material is thickest, on the sleeve, 12, on the section immediately below the thread. Because the sleeve, 12, generally has a thin wall, care must be exercised in tightening such that the sleeve, 12, will not be distorted. After tightening, the fishing grapple, 10, is prepared for use by extending the grapple element, 13, and engaging the keys, 15, into the upper J-latches, 16.
Referring now to FIG. 3, the fishing grapple, 10, is shown as it would appear while descending the well casing, 50. Keys, 15, as shown in FIG. 4, located in the sleeve, 12, are engaged by being in direct contact with the upper J-latches, 16, which are an integral part of the grapple element, 13. A screw-on grapple retainer, 14, is employed as a means for retaining the grapple element, 13, within the sleeve, 12. A top sub, 11, is screwed on to the sleeve, 12. The entire assembly, 10, is screwed on to a fishing string for the trip down the well casing, 50.
When the assembly reaches the fish, 20, weight is applied to the fishing string causing the lower portion, or fingers, 21, of the grapple element, 13, to expand around the fish, 20, as illustrated in the cross-section view of FIG. 5. The weight applied to the fishing string is transmitted through the top sub, 11, screwed-on to the sleeve, 12, forcing the keys, 15, against the upper J-latches, 16, which, being an integral part of the grapple element, 13, causes the fingers, 21, of the grapple element, 13, to come in direct contact with the fish, 20, and thereby begin expanding.
After the grapple, 10, is fully engaged to the fish, 20, as shown in FIG. 6, the fishing string is rotated (counter-clockwise looking down the string) 1/8th turn. This disengages the keys, 15, located in the sleeve, 12, from the upper notches or J-latches, 16. The weight is continuously applied to the fishing string, and the keys, 15, slide down to the bottom of the vertical slot, 18, in the grapple element, 13, at which point the fishing string is rotated in the opposite direction (clockwise) 1/8th turn. This engages the keys, 15, located in the sleeve, 12, to the lower notches or J-latches, 17. At this point the entire assembly, 10, including the fish, 20, is prepared for lifting out of the well casing, 50, as shown in FIGS. 7-8.
During the ascent, a small amount of torque (clockwise) is applied to the fishing string to assure constant contact of the keys, 15, with the lower notches or J-latches, 17.
In the event the fish cannot be retrieved, the assembly can be disengaged by rotating the fishing string (counter-clockwise) 1/8th turn, disengaging the keys, 15, located in the sleeve, 12, from the lower notches or J-latches, 17. The fishing string is lifted, which allows the keys, 15, located in the sleeve, 12, to slide up to the top of the vertical slot, 18, in the grapple element, 13, at which point the fishing string continues being pulled up, allowing the fingers, 21, of the grapple element, 13, to be expanded and pulled free from contact with the fish which cannot be retrieved. The entire assembly, minus the fish which cannot be retrieved, is then removed from the well casing, 50.
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An apparatus and method for removing fish from a well, said apparatus including a top sub with upper and lower ends, the upper end adapted to be connected to a drill string, a grapple sleeve connected to the lower end of the top sub and a grapple, which in the preferred embodiment incorporates grapple fingers so as to externally engage and grasp a fish in a well slidably mounted within the grapple sleeve. The grapple is mounted to the top sub and extends out of and into the grapple sleeve such that once the fish is engaged the grapple may be withdrawn into the grapple sleeve, which in turn allows for the maintaining of a constant force on the grapple and fish engaged therein. The method of the present invention includes running into the well a drill string having a grappling tool attached thereto, locating the fish by making contact with the grappling tool, engaging the fish with the grapple, and removing the fish from the well.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a nonprovisional application which claims priority from prior provisional U.S. patent application Ser. No. 60/329,434 filed on Oct. 15, 2001, and entitled A NEW OPTICAL FIBER FOR USE AT HIGH TEMPERATURE IN AN ENVIRONMENT CONTAINING HYDROGEN GAS.
GOVERNMENT RIGHTS
This invention was made with Government support under Contract DE-AC04-94AL85000 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.
FIELD OF THE INVENTION
The present invention relates generally to temperature sensors, and in particular to a new class of optical fiber distributed temperature sensors suited to use in harsh, hydrogen-containing environments.
BACKGROUND OF THE INVENTION
One of the niche applications for fiber optics is distributed temperature sensing in geothermal wells. A temperature profile obtained shortly after drilling will determine the potential of a well for use in power generation, and provides guidance as to how to best harness heat generated by the well.
Additionally, long-term thermal monitoring of a power-producing geothermal well is needed to operate the well so that production of electric power is optimized. Additional water must periodically be re-injected into the well, resulting in localized cooling. Efficient operation of a geothermal well often requires that the re-injection point be moved to a hotter region of the well. It is well known in the art that a vertical temperature profile of an entire geothermal well can be obtained essentially instantaneously using a single optical fiber. As a result, use of an optical-fiber distributed temperature sensing system as a geothermal well logging tool is held to offer much potential.
The operating principles of a typical optical fiber distributed temperature sensor follow. When light of a frequency (o interacts with a medium in which molecular or lattice vibration is taking place at a frequency ω r said light will be Raman scattered from the medium. The scattered light will include frequencies of ω+ω r as well as the original frequency ω. A portion of this scattered light propagates opposite to the propagation direction of the incident light, or is backscattered.
The intensity of the various frequency components of the backscattered light are found to depend on the temperature of the medium at the point where the backscattered light is generated. Accordingly, proper detection and analysis of the backscattered light in a medium allows one to determine the distribution of temperature in that medium.
In a prior art optical fiber distributed temperature sensor, a light of a known frequency is introduced into an optical fiber whose temperature distribution along its length is to be measured. The backscattered light is collected, and spectral analysis of the backscattered light is carried out using time domain techniques.
The result is a relationship between temperature of the backscattering medium and time. As the backscattering medium is part of the optical fiber, however, the time when the backscattered radiation is collected for analysis is directly related to the distance along the fiber where the backscattering medium is located. Thus, the relation between temperature and time can be easily converted into the desired relation between temperature and position along the fiber.
As mentioned before, use of an optical fiber distributed temperature sensor for monitoring and evaluation of geothermal wells is considered to be an attractive possibility in the art. For such use to be practical, however, requires that the optical fiber to be placed in the geothermal well can survive the harsh downhole environment for a period measured in years.
Field tests of optical fiber distributed temperature sensors in geothermal wells have demonstrated that conventional optical fibers are insufficiently robust for this type of application. In the hotter wells studies, anomalies associated with changes in the optical transmission characteristics of the optical fibers used were seen in as little as 24 hours. The optical fibers were rendered useless for the intended application within time periods far shorter than the required service life.
The transmission anomalies were found to relate to the formation of OH ions in the silicate glass matrix of the optical fibers. These OH ions did not exist in the optical fibers prior to their exposure to the downhole environment. The likely degradation mechanism is that hydrogen in the hot downhole environment diffuses into the fiber, and there reacts with the oxygen of the silicate glass to form OH ions.
The constituents of the glass are found to have a strong influence on the rate at which OH ions are formed in a typical downhole environment. Optical fibers typically have a core glass with a refractive index which is larger than that of a surrounding cladding glass. An optical fiber can have a step-index structure, where there is an essentially abrupt interface between the core and the cladding glasses, or can have a graded-index structure, where the properties of the fiber vary in a graded manner radially in the fiber.
A common usage is to introduce germanium to increase the core refractive index. It has been found, however, that the presence of germanium promotes the formation of OH ions in the downhole environment.
Phosphorous is also commonly added to the glass to improve manufacturing characteristics by reducing the viscosity of the molten glass. Phosphorous is found to promote the formation of OH ions to a greater extent than does germanium. Generally, then, commercially available optical fibers comprise materials which render them susceptible to hydrogen damage through OH ion formation.
The only solution to this problem which seems to have been explored by the geothermal industry is to introduce a hydrogen diffusion barrier at the surface of the optical fiber, to attempt to prevent diffusion of hydrogen into the fiber. Various barrier coatings, such as carbon, silicon oxynitride, and aluminum, have been investigated. Although such barrier coatings are found to be effective at low temperatures, their effectiveness largely disappears at higher temperatures, typically in excess of 250° C. As many geothermal applications involve exposure to environments hotter than this, such barrier coatings do not provide adequate protection for optical fiber distributed temperature sensors in geothermal applications.
Both phosphorous-free and germanium-free fibers have been tested in hot hydrogen-containing environments. However, even a step-index fiber with a pure silica core exhibits unacceptable levels of OH ion formation.
It is commonly held in the geothermal industry that routine usage of optical fiber-based sensors, and in particular distributed temperature sensors, as downhole instrumentation in geothermal wells is highly desirable. Other types of fiber-optic-based downhole sensors, such as interferometric strain and tilt sensors, are also desirable for use in hot, hydrogen-containing environments, but are difficult to implement owing to OH ion formation in the optical fiber.
There therefore exists need for optical fiber-based sensors, and in particular for optical fiber distributed temperature sensors, which comprises an optical fiber sufficiently resistant to OH ion formation within the downhole environment that said fiber, and hence said sensor, has a service life of sufficient duration for the intended applications.
The present invention addresses this need by incorporating in an optical fiber-based sensor system, and in particular in an optical fiber distributed temperature sensor, a type of optical fiber having sufficient resistance to OH ion formation in the downhole environment.
An advantage of using such a hydrogen-resistant optical fiber is that the service life of the resulting distributed temperature sensor is greatly extended relative to that of prior art distributed temperature sensors.
This and other advantages of the process of the present invention will become evident to those skilled in the art.
SUMMARY OF THE INVENTION
A new class of optical fiber distributed temperature sensors has been developed for use in hydrogen-containing environments generally, and in the geothermal well environment specifically. These new sensors use a hydrogen-resistant optical fiber to probe the temperature profile of the downhole environment, and offer improved resistance to degradation of sensor performance due to hydrogen-induced changes in the optical fiber optical transmission characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic illustration of a step-index optical fiber.
FIG. 2 shows a schematic illustration of a graded-index optical fiber.
FIG. 3 shows a schematic illustration of an optical fiber distributed temperature sensor according to the present invention.
DETAILED DESCRIPTION
There are two common forms of optical fibers. FIG. 1 shows a step-index optical fiber, in which fiber 100 comprises a core region 101 which is surrounded by a cladding region 102 . The fiber cross-sectional shape is typically circular, but other shapes are sometimes used for special applications.
The core region 101 has a core refractive index which is larger than is the cladding refractive index of the cladding region 102 . In typical step-index optical fibers the core refractive index is constant throughout the core region 101 , and the cladding refractive index is constant throughout the cladding region 102 . However, light is confined primarily to the core region 101 through the existence of an abrupt change in refractive index at the interface between the core region 101 and the cladding region 102 .
An example of graded-index optical fibers is shown in FIG. 2 . Here graded-index fiber 200 comprises an optical medium 201 distributed about an optical axis 202 . Again, the fiber cross-sectional shape is typically circular.
Optical medium 201 is so fabricated that the refractive index thereof varies radially with distance from optical axis 202 . This variation in refractive index is typically a monotonic decrease in refractive index with radial distance, with the largest refractive index appearing along optical axis 202 . The variation in refractive index with radial distance is often chosen to be substantially parabolic in radial distance. However, all that is necessary for function of a graded-index optical fiber is that the variation in refractive index with radial distance be such that light is trapped within and transmitted along the optical fiber.
All types of optical fiber can in principle be used in an optical fiber distributed temperature sensor. However, step-index optical fibers have a narrow bandwidth relative to a graded-index fiber. As a result, optical pulses lengthen in a step-index fiber to a much greater extent than in a graded-index fiber. This pulse broadening is sufficient in a typical step-index fiber to degrade the spatial resolution of an optical fiber distributed temperature sensor to a level well below that potentially enabled by the temporal resolution of the light source, detectors, and analytical system.
Both types of optical fiber require spatial changes in refractive index. Optical fibers are typically fabricated by pulling a fiber from a preform. A preform for a step-index fiber is typically a cylinder having a central region composed of a core glass composition, and a cladding region composed of a cladding glass composition with a smaller refractive index than does the core glass composition.
In contrast, a preform for a graded-index fiber is typically a glass cylinder in which the concentration of one component of the glass varies radially within the cylinder. Such graded-index preforms are typically made using chemical vapor deposition, where the composition of the material being deposited is changed in a controlled manner as the preform is grown out radially from an initial core material.
The required variations in refractive index are the result of radial variations in the composition of the glass preform. A common avenue is to create a preform with large amounts of germanium near the axis of the preform, but smaller amounts or no germanium near the cylindrical surface of the preform. Such preforms are in common use for production of commercial optical fibers. However, as discussed earlier, the introduction of germanium to the optical fiber results in increased susceptibility to hydrogen-induced degradation.
Research was carried out nearly two decades ago on OH ion formation in optical fibers for undersea communication, where hydrogen degradation of optical transmission is also a factor for long-term application (H. Wehr and F. Weling, “Transmission Loss Behavior of PCVD Fibers in H 2 Atmosphere”, Electronics Letters, Vol. 21, No. 19, Sep. 12, 1985, pgs 852-853, hereby incorporated by reference in its entirety). This research demonstrated that a test fiber containing fluorine showed no OH ion formation in a hydrogen-containing environment at 200° C.
Although the temperatures at which their research was carried out are well below those encountered in geothermal applications, the results of Wehr and Weling encourage, but do not establish or teach, the idea that use of fluorine-containing glasses in optical fibers intended for distributed temperature sensors in the downhole environment might be beneficial. However, despite the fact that optical fiber distributed temperature sensors were also developed in the mid-1980's, with an ongoing interest in their use in the geothermal environment since that time, a connection between this research result and distributed temperature sensors does not seem to have been made previously.
The inventor has tested a step-index fiber with a fused silica core and a cladding material whose refractive index was reduced relative to that of the fused silica core by introduction of fluorine. Although a small amount of transmission degradation by OH ion formation was observed at temperatures typical of the geothermal environment, this fiber outperformed all conventional fibers studied, whether protected by a diffusion barrier or not. This study confirms that such introduction of fluorine serves to greatly reduce OH ion formation in a hydrogen-containing environment at geothermal temperatures.
Introduction of fluorine into a silicate glass is known to reduce the refractive index thereof. As described earlier, the refractive index near the optical axis of an optical fiber must be larger than that of the optical medium near the cylindrical surface of the optical fiber. In addition, as the inventor has demonstrated that introduction of fluorine into the silicate glass is desirable to reduce or prevent OH ion formation in the geothermal environment, it is particularly desirable that fluorine be introduced into the core region of the silicate glass, where the majority of the optical power is concentrated.
Taking the above factors into account, a specific implementation of the present invention appears in FIG. 3 . Distributed temperature sensor 300 comprises a pulsed light source 301 which emits short pulses of light with a narrow bandwidth about a excitation frequency ω. Typically pulsed light source 301 comprises a pulsed laser having a pulse duration on the order of 10 nanoseconds in length, enabling a sensor spatial resolution of about a meter.
The output of pulsed light source 301 is directed into input 302 of hydrogen-resistant optical fiber 303 , which is positioned so as to measure the desired temperature distribution. Backscattered light 304 emerges from input 302 , and is directed by beamsplitter 305 into time domain analyzer 306 .
Time domain analyzer 306 analyzes the spectral components of backscattered light 304 as a function of time elapsed since the pulse of light was emitted by pulsed light source 301 , and uses the time-resolved spectral information to determine the distribution of temperature along the length of hydrogen-resistant optical fiber 303 .
Hydrogen-resistant optical fiber 303 is so fabricated that it contains fluorine throughout the structure of the fiber. As discovered by the inventor, introduction of fluorine dramatically reduces OH ion formation in the geothermal environment.
In a specific set of implementations, fiber 303 is a graded-index fiber with fluorine distributed therein so that a large concentration of fluorine exists near the cylindrical surface, and the concentration of fluorine decreases near the optical axis of the fiber. In a particularly desirable implementation, the concentration of fluorine increases parabolically with radial distance from the optical axis. The glass into which fluorine is introduced to form 303 can be pure silica glass or a silicate glass. Chlorine can be introduced to reduce OH ion formation during manufacture of the fiber.
In an alternate implementation, fiber 303 takes the form of a step-index fiber. Such a step-index fiber can exhibit either single mode or multi-mode transmission, depending on the detailed construction thereof. A single mode optical fiber can enable interferometric applications, such as remote strain and tilt sensors. Here it is particularly beneficial that the core region contain fluorine, as the majority of the optical energy is concentrated in the core region. If a single fluorine-doped glass is used to make the fiber, this requires that the cladding region contains a larger concentration of fluorine than does the core region. If two different glasses are used, however, the cladding region need not contain fluorine.
The specific implementations of the present invention described above are intended only to illustrate various features of the present invention. The scope of the present invention is intended to be set by the claims in view of the specification.
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A new class of optical fiber based thermal sensors has been invented. The new sensors comprise hydrogen-resistant optical fibers which are able to withstand a hot, hydrogen-containing environment as is often found in the downhole well environment.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a nonprovisional and claims the priority benefit of pending U.S. provisional patent application Ser. No. 61/552,032 filed Oct. 27, 2011, entitled METHOD OF TREATMENT ANALYSIS WITH FLOW CYTOMETER by the same named inventors and held by a common assignee. The entire content of that priority application is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to an optical flow imaging and analysis configuration used in particle analysis instrumentation, and more particularly to an optical flow imaging system used to detect the effectiveness of fluid treatment.
[0004] 2. Description of the Prior Art
[0005] The art has seen various optical/flow systems employed for transporting a fluid within an analytical instrument to an imaging and optical analysis area. A liquid sample is typically delivered into the bore of a flow chamber and this sample is interrogated in some way so as to generate analytical information concerning the nature or properties of the sample. For example, a laser beam may excite the sample that is present in the bore of the capillary, with the emitted fluorescence energy representing the signal information.
[0006] From an optical perspective, the objectives and flow chambers have included those of low to medium numerical aperture (NA). A typical flow imaging system includes a cylindrical or rectangular glass rod having a hollow co-axial cylindrical or rectangular bore of smaller diameter, in which the sample to be analyzed is placed. With the sample in place, optical analysis is performed with low to medium numerical aperture (NA) optics (e.g., NA 32 0.6), typically an air objective. Such low to medium NA optics are considered easier to use and more suitable for dealing with the limitation of having the fluid of interest spaced from the optics by the thickness of the rod wall, which are simply too thick to permit use of high NA optics.
[0007] Nevertheless, high NA optics systems have been developed and used to detect the content of fluid samples. One such system that has proven to be effective at organism detection is described in U.S. Pat. No. 7,796,256, issued Sep. 14, 2010. That system includes an oil-immersion arrangement to facilitate the use of high NA optics. The entire content of U.S. Pat. No. 7,796,256 is incorporated herein by reference.
[0008] The flow-based imaging systems in existence to date have been limited in their usage as an aid to determine the quantity and type of organism contained in a fluid sample. That information is of value in understanding what is likely in the fluid from which that sample was acquired. The recipient of that information must then decide what to do, if anything, with that knowledge. Until the present invention, imaging systems were employed only to establish organism type and, as effectively as possible, the number of such organisms per some volumetric value. Beyond that, imaging systems, including flow cytometers, have not been used for the purpose of assessing the effectiveness of any effort carried out to deal with such organisms. Primarily, the organism or organisms for which neutralization or elimination is of interest.
[0009] To date, imaging systems have not been used for the purpose of assessing the effectiveness of efforts to neutralize or eliminate organisms of a fluid. For example, undesirable organisms contained in drinking water and ballast water, but not limited thereto. What is needed is a system and method for determining the effectiveness of fluid treatment efforts.
SUMMARY OF THE INVENTION
[0010] The present invention is a method for using flow-based particle imaging to determine the effectiveness of a fluid treatment effort. The method includes the use of an optical system including a flow chamber, an imaging objective, and an imaging light source, as well as an objective and a condenser. Any form of such a system may be employed, provided it generates sufficient resolution to ensure the detection of organisms in a manner that allows the user to distinguish the difference between live organisms and dead ones. Suitable forms of the system include, without limitation, the FlowCam® imaging system provided by Fluid Imaging Technologies, Inc., of Yarmouth, Me. A flow cytometer may be used.
[0011] The method of the present invention includes as primary steps the steps of acquiring one or more samples from a fluid prior to treatment, passing the sample or samples through the flow-based particle imaging system, gathering data regarding characteristics of particles, such as organisms, in the sample(s) and storing that data. The method further includes the steps of acquiring another one or more samples from the fluid after treatment, passing the sample or samples through the imaging system, gathering data regarding characteristics of the particles in the sample(s) and storing that data. The steps associated with acquiring one or more samples of the fluid after treatment, passing the sample(s) through the imaging system and gathering data of particle characteristics may be repeated one or more times. The characteristics information gathered, including colors of the organisms, before and after treatment of the fluid are then compared to observe any changes in those characteristics that may have occurred as a result of the fluid treatment effort. The inventors of the present invention have determined that organisms presenting a first color when alive present a second, different, color when dead. More specifically, the second color has been determined to be evidence of the death of the organism wherein the remains of the organism become transparent. In experiments conducted, it was observed that some organisms that had died presented a blue color in the imaging analysis as an indication of their transparency. Other organisms present other colors after death, including green and red, for example, and even those that change from opaque to transparent represent organism death.
[0012] The method of the present invention enables the evaluation of the effectiveness of a fluid treatment procedure to eliminate particles, such as organisms, from the fluid. When a fluid, such as the water of a watercraft ballast tank, is treated with a cleaning solution, such as chlorine, there is a desire to determine whether sufficient harmful organisms have been destroyed. The method of the present invention allows for that determination by enabling the examination of those organisms before and after the treatment.
[0013] This and other advantages of the present invention will become more readily apparent upon review of the following detailed description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 schematically illustrates a system for studying particles in a fluid according to one embodiment of the invention.
[0015] FIG. 2 is an enlarged perspective view of the optics and flow chamber of the system of FIG. 1 .
[0016] FIG. 3 is a table of treatment type and results and images obtained in a first experiment involving the method of the present invention.
[0017] FIG. 4 is a graph showing the average measurement of blue particles detected in the first experiment.
[0018] FIG. 5 is a table of treatment type and results and images obtained in a second experiment involving the method of the present invention.
[0019] FIG. 6 is a graph showing the average measurement of blue particles detected in the second experiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] A system 10 suitable for use in carrying out the method of the present invention in high quality imaging that exist in a fluid sample is shown in FIGS. 1 and 2 . The system 10 includes a flow chamber 15 , a light source 30 , optics 35 , an image detection system 40 , a backlighting generator 50 , an image capturing system 60 , a computing device 65 , a high NA objective 75 and a high NA condenser lens 95 . The combination of these components of the system 10 arranged and configured as described herein enable a user to detect particles in the fluid and produce high resolution images of those particles. The system 10 illustrated is a presentation of one form of the FlowCam® flow-based particle imaging system available from Fluid Imaging Technologies, Inc., of Yarmouth, Me. A flow cytometer may be used for that purpose.
[0021] The flow chamber 15 includes an inlet 20 for receiving the particle-containing fluid to be observed, and an outlet 25 through which the fluid passes out of the flow chamber 15 after imaging functions have been performed. The flow chamber 15 may be fabricated of a material that does not readily fluoresce, including, for example, but not limited to, microscope glass or rectangular glass extrusions, or other materials suitable to allow particle detection and imaging. The flow chamber 15 may be circular or rectangular in shape. The flow chamber 15 defines a channel 15 a through which the fluid flows at a predetermined selectable rate. The channel 15 a may be of rectangular configuration. The flow chamber 15 is fabricated with a wall thickness that substantially matches the thickness considered suitable by the manufacturer of the high NA objective 75 described herein. For example, the wall thickness of the flow chamber 15 should substantially match that of a microscope cover slide. The inlet 20 of the flow chamber 15 is connectable to a fluid source and the outlet 25 is connectable to a downstream means for transferring the fluid away from the flow chamber 15 .
[0022] A light source 30 is used to generate excitation light, which is passed through the optics 35 to the flow chamber 15 , resulting in particle light scatter. The light source 30 may be a Light Emitting Diode (LED) or another form of light source. The detection system 40 , which may include a lens, is configured to detect particles existing in the flow chamber 15 when the light source 30 is activated. Output from the detection system 40 is processed by detection electronics 45 . Preferably, the detection electronics 45 includes user-adjusted gain and threshold settings which determine the amount of scatter required for the system 10 to acknowledge a passing particle. The detection electronics 45 may be configured to receive input signals and produce output information compatible with the specific needs of the user of the system 10 . An example of a suitable electronics system capable of performing the signal activation and output information associated with the detection electronics 45 of the system 10 is the detection electronics described in U.S. Pat. No. 6,115,119 issued Sep. 5, 2000, the entire content of which is incorporated herein by reference. Those of ordinary skill in the art will recognize that the specific electronics system described therein may be modified, such as through suitable programming for example, to trigger desired signal activation and/or to manipulate received signals for desired output information.
[0023] If a sufficiently lighted particle passes through the flow chamber 15 , a signal from the detection system 40 is sent to the detection electronics 45 , which then generate one or more trigger signals that are transmitted to the computing device 65 . The computing device 65 is programmed to store the information received from the detection electronics 45 and to make calculations associated with the particles detected. For example, but not limited thereto, the computing device 65 may be programmed to provide specific information regarding the shape of the particles, dimensions of the particles, and specific features of the particles. The computing device 65 may be any sort of computing system suitable for receiving information, running software programs on its one or more processors, and producing output of information, including, but not limited to images and data, that may be observed on a user interface.
[0024] The detection electronics 45 may also be coupled, directly or indirectly through the computing device 65 to the backlighting generator 50 . In particular, the detection electronics 45 and/or the computing device 65 may include an arrangement whereby a user of the system 10 may alternatively select a setting to automatically generate a trigger signal at a selectable time interval. The trigger signal generated produces a signal to activate the operation of the backlighting generator 50 so that a light flash is generated. Specifically, the backlighting generator 50 may be a LED or other suitable light generating means that produces a light of sufficient intensity to backlight the flow chamber 15 and image the passing particles. The very high intensity LED flash may be a “white” LED flash, or a flash of another other suitable wavelength, which is flashed on one side of the flow chamber 15 for 200 μsec (or less). At the same time, the image capturing system 60 positioned on the opposing side of the flow chamber 15 is activated to capture an instantaneous image of the particles in the fluid as “frozen” when the high intensity flash occurs. The image capturing system 60 is arranged to either retain the captured image, transfer it to the computing device 65 , or a combination of the two. The image capturing system 60 includes characteristics of a digital camera or an analog camera with a framegrabber or other means for retaining images. For example, but in no way limiting what this particular component of the system may be, the image capturing system 60 may be, but is not limited to being, a CCD firewire, a CCD USB-based camera, or other suitable device that can be used to capture images and that further preferably includes computing means or that may be coupled to computing means for the purpose of retaining images and to manipulate those images as desired. The computing device 65 may be programmed to measure the size and shape of the particle captured by the image capturing system 60 and/or store the data for later analysis.
[0025] The system 10 also includes the high NA objective 75 and the high NA condenser lens 95 as part of the optics 35 . The high NA condenser lens 95 aids in clear illumination of that section of the fluid in the flow channel 15 a that is to be imaged by focusing the high intensity flash from the backlighting generator 50 to that section. The high NA condenser lens 95 includes characteristics of a numerical aperture of about 1.25 and may be the AA2354932 1.25NA Abbe condenser available from Motic Incorporation Ltd. of Hong Kong. The high NA objective 75 is arranged to focus the illuminated image to the image capturing system 60 . The high NA objective 75 also focuses fluorescence excitation light from the light source 30 onto the flow chamber 15 . Further, the high NA objective 75 focuses the resulting scattered light onto the detection system 40 . The high NA objective 75 is selected to have a range of focus or “working distance” which ensures that focus is substantially maintained through the entirely of the cross section of the flow channel 15 a. Further, the high NA objective 75 includes characteristics of a numerical aperture greater than 0.7 and may be the EF Plan 100X/1.25NA available from Motic Incorporation Ltd. of Hong Kong.
[0026] The method of the present invention embodied in one or more computer programs includes steps associated with storing and analyzing images captured with the system 10 of the present invention. In the first step, the light source 30 and imaging optics 35 generate scatter excitation light, which is directed to the flow chamber 15 within which a fluid to be monitored passes. The detection system 40 including the control electronics 45 is used to detect separately, images associated with the light waveforms scattered from particles in the flow chamber 15 . The detected images are transferred to the computing device 65 for storage and analysis. The images captured are characterized based on particle shape, size and color, in addition to other information that may be of interest. Color features representative of the particles in the fluid are detected and reported in a visual manner. For example, the information may be presented in graphic representations, spreadsheet lists, or combinations thereof. Optionally, the acquired image information may be used to count the number of particles in the fluid sample observed and reported. Captured images are compared to known or similar images of particles of interest and reported.
[0027] The steps identified are carried out in the examination of a fluid source, wherein fluid samples are acquired from the fluid source and transferred to the flow chamber 15 . The fluid samples are acquired before and after treatment of the fluid source. For example, if the fluid source is a ballast tank, one or more first samples are acquired and examined. A treatment procedure is then completed and a second examination is performed by taking one or more new samples from the fluid source that has been treated. The examination steps may be repeated before and after treatment as desired.
[0028] It is to be understood that the computing device 65 used to gather the captured image information and to perform calculations and observe features of the captured image information may be associated with local or remote computing means, such as one or more central computers, in a local area network, a metropolitan area network, a wide area network, or through intranet and internet connections. The computing device 65 may include one or more discrete computer processor devices. The computing device may include computer devices operated by a centralized administrative entity or by a plurality of users located at one or more locations.
[0029] The computing device 65 may be programmed to include one or more of the functions of the system 10 . The computing device 65 may include one or more databases including information related to the use of the system 10 . For example, such a database may include known images of example particles of interest. The database may be populated and updated with information provided by the user and others.
[0030] The steps of the method described herein may be carried out as electronic functions performed through the computing device 65 based on computer programming steps. The functions configured to perform the steps described herein may be implemented in hardware and/or software. For example, particular software, firmware, or microcode functions executing on the computing device 65 can provide the trigger, image capturing and image analysis functions. Alternatively, or in addition, hardware modules, such as programmable arrays, can be used in the devices to provide some or all of those functions, provided they are programmed to perform the steps described.
[0031] The steps of the method of the present invention, individually or in combination, may be implemented as a computer program product tangibly as computer-readable signals on a computer-readable medium, for example, a non-volatile recording medium, an integrated circuit memory element, or a combination thereof. Such computer program product may include computer-readable signals tangibly embodied on the computer-readable medium, where such signals define instructions, for example, as part of one or more programs that, as a result of being executed by a computer, instruct the computer to perform one or more processes or acts described herein, and/or various examples, variations and combinations thereof. Such instructions may be written in any of a plurality of programming languages known to those of skill in the art including, for example, C++, but not limited thereto. The computer-readable medium on which such instructions are stored may reside on one or more of the components of system 10 described above and may be distributed across one or more such components.
[0032] Two experiments were conducted to evaluate the effectiveness of the method of the present invention in providing an assessment of the impact of a fluid treatment procedure. In the first experiment, raw water was drawn from the Portland, Me., area of Casco Bay to serve as a typical ballast water sample. The sample was thoroughly mixed and separated into 1 Liter bottles. Each bottle represented a different ballast water treatment technique: Nitrogen Purge, Chemical Treatment (Chlorine), and UV exposure. The purpose of the first experiment was to determine whether it was possible to differentiate between when the organisms are live (Start of experiment), and when they are dead (Day 4). Specifically, the steps of the method of the present invention were carried out on Day 1 prior to the treatment process. The steps of the method of the present invention were again carried out four days after treatment for the purpose of evaluating the effectiveness of the treatment. The differentiation was made with respect to the amount of blue color measured using the FlowCam® system, including whether the amount of blue color observed increased as the organisms died due to the transparency of the organism's remains. FIGS. 3 and 4 represent the results of the first experiment. As can be seen from FIGS. 3 and 4 , it was determined that it is possible to detect a change in blue color of the organism images captured. In addition, it was also determined that a quantitative distinction could be made among the three methods of treatment employed.
[0033] The second experiment was designed to give an indication of what particle parameters determined by the FlowCam® system can be used to indicate how ‘dead’ a ballast water sample is after undergoing a chemical treatment intended to kill organisms. In the second experiment, 120 ml of a fluid representative of ballast water was set aside in a beaker and then 1 ml of the sample was analyzed with the FlowCam® system in accordance with the steps listed above. Soon after the analysis was completed, approximately 0.25 ml of chlorine bleach was added to the sample resulting in a 0.25% Cl mix (volume/volume). After one hour, the sample was analyzed and the average blue for all the particles was monitored. The analysis was repeated 2 hours, 3 hours, and 6 hours after the treatment was performed. Analysis of the samples for the second experiment was specifically carried out on FlowCam® system serial number 575 with a 10× objective, FC100 flow cell, color camera, and in AutoImage mode. FIG. 5 shows the results and images for samples taken before treatment and one and three hours after treatment. It can be seen that qualitative and quantitative determinations have been made indicating the effectiveness of the treatment with chlorine based on the observed blue color of the organisms detected. FIG. 6 also corresponding information, including that the treatment was substantially completed after about two hours, with little further indication of increasing blue color observed.
[0034] There is a noticeable effect of before-and-after chemical treatment of fluid samples containing organisms as measured by a version of the system 10 using the method of blue color observation of the present invention. It will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the system may be used to detect any particle change indicative of organism death. While the invention has been described with respect to a particle organism that presents blue when dead, other changes are detectable with the system and method of the present invention including, but not limited to, a change to a different color, such as green or red, or a change from opaque to transparent. Accordingly, other embodiments are within the scope of the claims appended hereto.
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A method for determining the effectiveness of the treatment of a fluid for the purpose of reducing or eliminating particles in the fluid. The method includes the steps of obtaining samples of the fluid before and after treatment, delivering the samples to a particle imaging system, obtaining image information of particles in the samples, including particle colors, and comparing the difference in particle color from the first sample to the second sample. A change in particle color detected is indicative of particle death.
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BACKGROUND OF THE INVENTION
This invention relates to an improvement of the components in the headrail of the venetian blind.
Conventionally, a venetian blind is provided in its headrail with a lift lock to set the lifting level of the slats as desired and a tilt device to adjust the tilt angle of the slats. A pair of lift cords are passed through the lift lock and a tilt wand is provided to actuate the worm gear in the tilt device. The lift cords and the tilt wand are suspended in front of the venetian blind for facilitating the operation thereof. In general, the operation will be optionally carried out at the right-hand or left-hand side with respect to the window to which the venetian blind is mounted. With a conventional venetian blind it is impossible to fulfill the requirement of this option, since the positions that the tilt device with the tilt wand and the lift lock with the lift cords are disposed cannot be changed as desired, unless another venetian blind with the tilt device and the lift lock in different positions is employed.
SUMMARY OF THE INVENTION
The object of this invention is to provide an improvement relating to the components in the headrail of the venetian blind in such a manner that the same venetian blind may be used in different situations to meet the requirement of different operational positions simply with minimum displacement of a few parts.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the following particular description of preferred embodiments of the invention as illustrated in the accompanying drawings, in which:
FIG. 1 is a schematic perspective new in general illustrating an embodiment of the improvement according to the present invention, partially broken away;
FIG. 2 is a perspective view of the lift lock component according to the present invention;
FIG. 3 is a lateral side view of FIG. 2, with a fragmentary bottom of the headrail in cross section;
FIG. 4 is a perspective bottom view of FIG. 2, with the limit pins exploded;
FIG. 5 is a perspective view of the tilt device component according to the present invention in exploded state; and
FIG. 6 is a side view of FIG. 5 in combination state, in partial cross section.
DETAILED DESCRIPTION
Now, reference is made to FIG. 1, which illustrates one embodiment of the venetian blind consisting of a headrail 1, a tilt tube 2, a pair of cradles 3, a pair of drums 4 and a plurality of slats 5, as conventional and hence the descriptions of their constructions and functions are omitted herein.
According to the present invention a novel lift lock 6 is fitted into the opening preformed at the bottom of said headrail 1 and a novel tilt device 7 is disposed in the headrail 1 with the hook end 8 protruded out of a preformed aperture at either side of the headrail 1.
As usual, a tilt wand 9 is engaged at the top end with said hook end 8, and a pair of lift cords 10 respectively passing through separate slots 11 in each slat 5 until connected at each one end to the support plate 12 is passed through the lift lock 6. Both tilt wand 9 and lift cords 10 are suspended in front of the venetian blind.
FIG. 4, and also referred to FIG. 2, shows the lift lock 6 consisting of a housing 12 with respective forked flange 13 at its base and a plurality of teeth 14 within the limit of said flange 13 at both ends, e.g. three teeth as shown. So that there are formed inner notches 15 between adjacent teeth 14 to each other as well as outer notches 15' between side teeth 14 and the flange 13. A pin 16 bent in a U-shape is inserted with two leg portions into the outer notches 15' from one end through another end of the housing 12. At the near end of the housing 12, i.e. at the left lower end in FIG. 4, teeth 14 preferably overhang the support 17 to have a short distance just to receive the connecting portion of the U-shaped pin 16. Another pin 18 in the form of a straight bar is selectively inserted into either the inner notch 15 close to one lateral side at a position as shown by the solid line, or the inner notch 15 close to other lateral side of the housing 12 at a position as shown by two dot-and-dash lines. Two stop means 19 are porvided at both sides to have a short distance from said forked flange 13, to such an extent that this distance is just fitted onto the edge of the preformed opening at the bottom 20 of said headrail 1 when the lift lock 6 is mounted therein, as best seen in FIG. 3. At another end of the housing, i.e. right upper end in FIG. 4, a pair of tongues 21 are formed at opposite sides extending towards the base, having a function to retain the housing 12 on the bottom 20 of the headrail 1 at said end.
In the housing guide roll 22 with opposite inner flanges 23 is rotatably secured and a floating roll 24 serving as lock means is freely rotatably contained therein in parallel to said guide roll 22. Said floating roll 24 has a rough surface such as an embossed surface. The function and action of the lift lock 6 are just as in a conventional lift lock and thus omitted in further description.
In application said pin 16 will prevent the lift cords 10 from contact with the lateral side walls of the housing 12 to cause any friction and abrasion. When the venetian blind is to be installed with the lift lock 6 at the right hand side, in other words, the lift cords are operated at the right hand side, as shown in FIG. 1, with respect to the window, not shown, the pin 18 is inserted into the inner notch 15 close to the front side. Then the lift cords 10 are passed through the space defined between the pins 16 and 18, as referred to in FIG. 1. On the contrary, when the venetian blind would be installed with the lift lock 6 and thus the lift cords 10 at the left hand side, one only has to change the pin 18 to another inner notch 15 close the rear side and confine the lift cords into the new space between the pin 16 and pin 18 in the new location, then turn around the venetian blind whole set including the headrail 1 and all slats 5. Now, the lift cords 10 can be operated at the left hand side with respect to the window.
As illustrated in FIGS. 5 and 6, the tilt device 7 according to the present invention is composed of two halves to make a central meeting line 25 and a bottom arch 26. In combination a D-shaped opening 27 and two holes 28 at below said opening 27 in the proximity of said arch 26 are extended axially through the device 7. Two opposite slightly inclined passages 29 are extended radially. The D-shape opening 27 is also passed through the worm gear 30 for the tilt tube 2 passing there-through. The worm 31 with hook end 8 is meshed at its top portion with said worm gear 30 and formed with an annular groove 32 at an intermediate portion. A clip with one straight leg 33 and another curved leg 34 is provided. When the clip is set with its straight leg 33 releaseably inserted into one of the holes 28 passing by the annular groove 32 of the worm 33 and its curved leg 34 clamped on the bottom arch 26, then the worm 31 is retained in the corresponding passage 29 in engagement with the worm gear 30.
When the venetian blind is installed with the tilt device 7 at the left hand side, in other words, the tilt wand 9 is operated at the left hand side, as shown in FIG. 1, with respect to the window, not shown, the worm 31 with hook end 8 is projected out of the preformed aperture at the front side of the headrail 1. On the contrary, when the venetian blind is to be installed with the tilt device 7 and thus the tilt wand 9 at the right hand side, one only has to pull out the clip, take out the worm 31 and re-insert it from the preformed aperture at another side, i.e. the rear side of the headrail 1 into another passage 29, then insert the clip back to retain the worm 31. Now, the venetian blind whole set including the headrail 1 and all slats 5 may be turned around. Thereby, the tilt wand 9 can be operated at the right hand side with respect to the window.
In the embodiment as illustrated the tilt wand 9 and the lift cords 10 are disposed at opposite ends of the venetian blind, but not limited here. For example, both tilt wand 9 and lift cords 10 may be disposed at the same end too.
While the invention has been particularly shown and described above with respect to preferred embodiment, the foregoing and other changes in form and detail may be made therein by one skilled in the art without departing from the spirit and the scope of the invention.
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A lift lock component and a tilt device component for a venetian blind which are fitted into the headrail of the venetian blind. These components and the headrail are constructed and arranged so that the same venetian blind can be used in different situations to meet the requirement of different operational positions simply with a minimum displacement of a few parts of the components.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to handle of wheeled luggage and more particularly to a retractable handle with its tubes having added strength in construction.
[0003] 2. Description of Related Art
[0004] A conventional U-shaped retractable handle 70 mounted on top of a wheeled luggage is shown in FIG. 1 . The handle 70 comprises, at its either side, a support tube 80 and a sliding tube slidably received in the support tube 80 . A stop sleeve 81 is provided on top of the support tube 80 for preventing the sliding tube from disengaging from the support tube 80 while extending the handle 70 .
[0005] Currently, thickness of the handle tube is reduced to a range of 0.4 mm to 0.45 mm for saving the manufacturing cost and decreasing weight of the luggage. However, the handle 70 may vibrate strongly when a piece of luggage fully packed with bulky items is being towed on an uneven surface or towed on a stepped floor up and down operation (see arrow in FIG. 1 ). This may easily deform the handle tubes or cause a separation of the stop sleeve 81 from the support tube 80 . Hence, a need for improvement exists.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a handle system mounted on a wheeled luggage, the handle system including two tube assemblies of rectangular section at both sides and a handle grip interconnected the tube assemblies, either tube assembly comprising a support tube having its bottom end fixedly coupled to a bottom of luggage, the support tube including, at either side wall of an upper portion thereof, a first recess and a plurality of first apertures longitudinally disposed below the first recess; a first stop sleeve including a first flange provided on its top mouth, the first flange being adapted to rest on a top of the support tube, the first stop sleeve further including, at its either side wall, a second recess proximate the first flange and a plurality of first latches disposed below the second recess, the first latches being disposed in the first apertures for securing the first stop sleeve to the support tube; and a sliding tube sub-assembly adapted to insert through the first stop sleeve into the support tube, the sliding tube sub-assembly including, at its either side wall, a recessed portion proximate its bottom mouth, wherein each of the recesses or the recessed portion is formed by punching for adding structural strength to the first stop sleeve, the support tube, or the sliding tube sub-assembly.
[0007] In one aspect of the present invention, the support tube further comprises an internal first locking device, and the sliding tube sub-assembly further comprises an outer sliding tube adapted to insert through the first stop sleeve into the support tube to be coupled to and to be locked by the first locking device, the outer sliding tube including, at its either side wall, a third recess proximate its top mouth, a plurality of second apertures longitudinally disposed below the third recess, a fourth recess proximate its bottom mouth, and an internal second locking device; a second stop sleeve including a second flange provided on its top mouth, the second flange being adapted to rest on a top of the outer sliding tube, the second stop sleeve further including, at its either side wall, a fifth recess proximate the second flange and a plurality of second latches disposed below the fifth recess; and an inner sliding tube adapted to insert through the second stop sleeve into the outer sliding tube to be coupled to and to be locked by the second locking device, the inner sliding tube including, at its either side wall, a sixth recess, wherein each of the recesses is formed by punching for adding structural strength to the second stop sleeve, the inner sliding tube, or the outer sliding tube.
[0008] In another aspect of the present invention, a rectangular third flange is provided on a top mouth of the support tube for permitting the first flange to rest thereon, and a rectangular fourth flange is provided on the top mouth of the outer sliding tube for permitting the second flange to rest thereon.
[0009] The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of a conventional luggage handle;
[0011] FIG. 2 is a perspective view of a first preferred embodiment of luggage handle according to the invention;
[0012] FIG. 3 is an exploded perspective view of components at either side of the handle of FIG. 2 ;
[0013] FIG. 4 is a perspective view of the assembled components of FIG. 3 where two portions are enlarged for depicting their details; and
[0014] FIG. 5 is a perspective view of either side of luggage handle according to a second preferred embodiment of the invention where two portions are enlarged for depicting their details.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Referring to FIGS. 2, 3 , and 4 , there is shown a U-shaped retractable handle constructed in accordance with a first preferred embodiment of the invention. The handle comprises two identical tube assemblies at both sides and an inverted U-shaped handle grip 60 interconnected the tube assemblies. Either tube assembly of rectangular section comprising a lower support tube 10 , an outer sliding tube 30 , an inner sliding tube 50 , and other associated components will be described in detailed below.
[0016] The support tube 10 has its bottom end fixedly coupled to a bottom of luggage. Also, either side wall of an upper portion of the support tube 10 is provided with a transverse first recess 12 proximate the mouth of a longitudinal channel 11 of the support tube 10 and two first apertures 13 longitudinally disposed below the first recess 12 . A first locking device 300 is provided in the support tube 10 . As locking device is a well known component in luggage handle, it will not be described in detail.
[0017] A first stop sleeve 20 is shaped to fit within an upper portion of the support tube 10 and comprises a longitudinal channel 21 and a rectangular first flange 22 provided on the top mouth of the channel 21 , the first flange 22 being adapted to rest on the mouth of the channel 11 so as to position the first stop sleeve 20 in the support tube 10 . Also, either side wall of the first stop sleeve 20 is provided with a longitudinal second recess 23 proximate the first flange 22 and intermediate and lower first latches 24 disposed below the second recess 23 .
[0018] The outer sliding tube 30 is adapted to insert into the channels 21 and 11 to be coupled to and to be locked by the first locking device 300 when the outer sliding tube 30 is retracted or extended to a desired position in the support tube 10 . Also, either side wall of an upper portion of the outer sliding tube 30 is provided with a transverse third recess 32 proximate the mouth of a longitudinal channel 31 of the outer sliding tube 30 , and two second apertures 34 longitudinally disposed below the third recess 32 . Moreover, either side wall of a lower portion of the outer sliding tube 30 is provided with a longitudinal fourth recess 33 . A second locking device 400 is provided in the outer sliding tube 30 . Again, as locking device is a well known component in luggage handle, it will not be described in detail.
[0019] A second stop sleeve 40 is shaped to fit within an upper portion of the outer sliding tube 30 and comprises a longitudinal channel 41 and a rectangular second flange 42 provided on the top mouth of the channel 41 , the second flange 42 being adapted to rest on the mouth of the channel 31 so as to position the second stop sleeve 40 in the outer sliding tube 30 . Also, either side wall of the second stop sleeve 40 is provided with a longitudinal fifth recess 43 proximate the second flange 42 and intermediate and lower second latches 44 disposed below the fifth recess 43 .
[0020] Either side wall of a lower portion of the inner sliding tube 50 is provided with a longitudinal sixth recess 53 . The inner sliding tube 50 is adapted to insert into the channels 41 and 31 to be coupled to and to be locked by the second locking device 400 when the inner sliding tube 50 is retracted or extended to a desired position in the outer sliding tube 30 .
[0021] As shown in FIG. 4 specifically, in an assembled position of either tube assembly of the handle the first latches 24 are disposed in the first apertures 13 and the second latches 44 are disposed in the second apertures 34 respectively. As a result, the first and second stop sleeves 20 and 40 are secured to upper portions of the support tube 10 and the outer sliding tube 30 respectively. Moreover, each recess is formed by punching for adding structural strength to the stop sleeve or the tube having a thin thickness at a range of 0.4 mm to 0.45 mm. As an end, the handle may not vibrate strongly when the luggage fully packed with bulky items is being towed on an uneven surface or the like. That is, the handle does not tend to deform and is thus durable, reliable.
[0022] Referring to FIG. 5 , there is shown a second preferred embodiment of the invention. The second preferred embodiment substantially has same structure as the first preferred embodiment. The differences between the first and the second preferred embodiments, i.e., the characteristics of the second preferred embodiment are detailed below. A rectangular third flange 15 is provided on the top mouth of the support tube 10 . The top mouth (i.e., flange) 22 of the first stop sleeve 20 is adapted to rest on the third flange 15 . Also, a rectangular fourth flange 35 is provided on the top mouth of the outer sliding tube 30 . The top mouth (i.e., flange) 42 of the second stop sleeve 40 is adapted to rest on the fourth flange 35 . This can enhance the securement of the first and second stop sleeves 20 and 40 to the upper portions of the support tube 10 and the outer sliding tube 30 respectively.
[0023] While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.
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Provided is a retractable luggage handle in which either tube assembly thereof comprises one or more stop sleeves each secured to a top of its tube by snapping latches of the stop sleeve into apertures of the tube. A plurality of recesses are formed on either side wall of each tube and each stop sleeve by punching for adding structural strength thereto.
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BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to a state model for a wireless communications device. In particular, the present invention discloses a finite state machine for the wireless device that includes a reset/suspend state.
2. Description of the Prior Art
Technological advances have moved hand in hand with more demanding consumer expectations. Devices that but ten years ago were considered cutting edge are today obsolete. These consumer demands in the marketplace spur companies towards innovation. The resulting technological advances, in turn, raise consumer expectations. Presently, portable wireless devices, such as cellular telephones, personal data assistants (PDAs), notebook computers, etc., are a high-growth market. However, the communications protocols used by these wireless devices are quite old. Consumers are demanding faster wireless access with greater throughput and flexibility. This has placed pressure upon industry to develop increasingly sophisticated communications standards. The 3 rd Generation Partnership Project (3GPP™) is an example of such a new communications protocol.
The 3GPP™ standard utilizes a three-layered approach to communications. Please refer to FIG. 1 . FIG. 1 is a simplified block diagram of the prior art communications model. A prior art wireless system includes a first device 20 and a second device 30 , both of which are in wireless communications with each other. As an example, the first device 20 may be a mobile unit, such as a cellular telephone, and the second device 30 may be a base station. An application 24 on the first device 20 needs to send data 24 d to an application 34 on the second device 30 . The application 24 connects with a layer 3 interface 23 (termed the radio resource control (RRC)), and passes the data 24 d to the layer 3 interface 23 . The layer 3 interface 23 uses the data 24 d to form a layer 3 protocol data unit (PDU) 23 p . The layer 3 PDU 23 p includes a layer 3 header 23 h and data 23 d , which is identical to the data 24 d . The layer 3 header 23 h in the layer 3 PDU 23 p contains information needed by the corresponding layer 3 interface 33 on the second device 30 to effect proper communications. The layer 3 interface 23 then passes the layer 3 PDU 23 p to a layer 2 interface 22 . The layer 2 interface 22 (also termed the radio link control (RLC)) uses the layer 3 PDU 23 p to build one or more layer 2 PDUs 22 p . Generally speaking, each layer 2 PDU 22 p has the same fixed size. Consequently, if the layer 3 PDU 23 p is quite large, the layer 3 PDU 23 p will be broken into chunks by the layer 2 interface 22 to form the layer 2 PDUs 22 p , as is shown in FIG. 1 . Each layer 2 PDU 22 p contains a data region 22 d , and a layer 2 header 22 h . In FIG. 1, the data 23 d has been broken into two layer 2 PDUs 22 p . Also note that the layer 3 header 23 h is placed in the data region 22 d of a layer 2 PDU 22 p . The layer 3 header 23 h holds no significance for the layer 2 interface 22 , and is simply treated as data. The layer 2 interface 22 then passes the layer 2 PDUs 22 p to a layer 1 interface 21 . The layer 1 interface 21 is the physical interface, and does all the actual transmitting and receiving of data. The layer 1 interface 21 accepts the layer 2 PDUs 22 p and uses them to build layer 1 PDUs 21 p . As with the preceding layers, each layer 1 PDU 21 p has a data region 21 d and a layer 1 header 21 h . Note that the layer 3 header 23 h and layer 2 headers 22 h are no more important to the layer 1 interface 21 than the application data 24 d . The layer 1 interface 21 then transmits the layer 1 PDUs 21 p to the second device 30 .
A reverse process occurs on the second device 30 . After receiving layer 1 PDUs 31 p from the first device 20 , a layer 1 interface 31 on the second device 30 removes the layer 1 headers 31 h from each received layer 1 PDU 31 p . This leaves only the layer 1 data regions 31 d , which are, in effect, layer 2 PDUs. These layer 1 data regions 31 d are passed up to a layer 2 interface 32 . The layer 2 interface 32 accepts the layer 2 PDUs 32 p and uses the layer 2 headers 32 h to determine how to assemble the layer 2 PDUs 32 p into appropriate layer 3 PDUs. In the example depicted in FIG. 1, the layer 2 headers 32 h are stripped from the layer 2 PDUs 32 p , leaving only the data regions 32 d . The data regions 32 d are appended to each other in the proper order, and then passed up to the layer 3 interface 33 . The layer 3 interface 33 accepts the layer 3 PDU 33 p from the layer 2 interface 32 , strips the header 33 h from the layer 3 PDU 33 p , and passes the data region 33 d to the application 34 . The application 34 thus has data 34 d that should be identical to the data 24 d sent by the application 24 on the first device 20 .
Please refer to FIG. 2 in conjunction with FIG. 1 . FIG. 2 is simplified block diagram of a layer 2 PDU 40 . The layer 2 PDU 40 has a layer 2 header 41 and a data region 45 . As noted above, the data region 45 is used to carry layer 3 PDUs 23 p received from the layer 3 interface 23 . The layer 2 header 41 includes a data/control indicator bit 42 , a sequence number field 43 , and additional fields 44 . The additional fields 44 are not of direct relevance to the present invention, and so will not be discussed. The data/control bit 42 is used to indicate if the layer 2 PDU 40 is a data PDU or a control PDU. Data PDUs are used to carry layer 3 data. Control PDUs are generated internally by the layer 2 interface 22 , 32 and are used exclusively for signaling between the layer 2 interfaces 22 and 32 , such as the passing of reset and reset acknowledgment signals. Control PDUs are thus never passed up to the layer 3 interface 23 , 33 . The sequence number field 43 contains a 12-bit or 7-bit value that is used to reassemble the layer 2 PDUs 40 into layer 3 PDUs 33 p . Each layer 2 PDU 22 p is transmitted with a successively higher value in the sequence number field 43 , and in this manner the layer 2 interface 32 knows the correct ordering of received layer 2 PDUs 32 p.
Please refer to FIGS. 3 and 4 in conjunction with FIGS. 1 and 2. FIGS. 3 and 4 are state model diagrams of a prior art layer 2 interface. The prior art layer 2 interface 22 , 32 is designed as a finite state machine. FIG. 3 depicts the state model for the layer 2 interface 22 , 32 when a reset command is performed. FIG. 4 depicts the state model when a local suspend command is performed. Transitions between states are noted by arrows in FIGS. 3 and 4. Received signals associated with a state transition are noted above a horizontal line, and signals sent in response to the state transition are noted below the horizontal line. The layer 2 interface 22 , 32 includes a null state 50 , a data transfer ready state 52 , a reset pending state 54 and a local suspend state 56 . To explain these state models, the first device 20 will be used as an example. When the layer 2 interface 22 is in the null state 50 , the layer 2 interface 22 has no established wireless channel 11 with the second device 30 . The layer 2 interface 22 of the first device 20 thus cannot transmit any layer 2 PDUs 22 p to the second device 30 . When the application 24 determines that it wishes to send the data 24 d to the application 34 , the application 24 signals this intent to the layer 3 interface 23 . The layer 3 interface 23 then performs whatever functions are necessary to establish the channel 11 with the second device 30 . In particular, the layer 3 interface 23 sends an establish primitive to the layer 2 interface 22 . On reception of the establish primitive, the layer 2 interface 22 transitions from the null state 50 to the data transfer state 52 . In the process of doing so, the layer 2 interface 22 establishes the wireless channel 11 with the second device 30 . While in the data transfer ready state 52 , the first device 20 can freely transmit layer 2 PDUs 22 p along the channel 11 . At any time when the layer 2 interface 22 is in the data transfer state 52 and receives a release primitive from the layer 3 interface 23 , the layer 2 interface 22 will transition back to the null state 50 . In the process of doing so, the layer 2 interface 22 will close down the channel 11 .
From time to time, the layer 2 interface 22 may determine that communications along the channel 11 are malfunctioning. In this case, the layer 2 interface 22 will desire to reset the communications system. To ensure that the entire system is reset, both the first device 20 and the second device 30 must be reset. To reset the second device 30 , the layer 2 interface 22 generates a reset control PDU, and sends the reset control PDU along the channel 11 to the layer 2 interface 32 on the second device 30 . The layer 2 interface 22 on the first device 20 then transitions from the data transfer state 52 to the reset pending state 54 . While in the reset pending state 54 , the layer 2 interface 22 will transmit no PDUs 22 p to the second device 30 along the channel 11 . This effectively halts communications along the channel 11 . The layer 2 interface 22 remains in the reset pending state 54 until reception of a reset acknowledgment control PDU from the layer 2 interface 32 on the second device 30 . This reset acknowledgment control PDU informs the layer 2 interface 22 that the layer 2 interface 32 received the reset control PDU and internally reset the layer 2 interface 32 . When the layer 2 interface 22 receives the reset acknowledgment control PDU, the layer 2 interface 22 transitions from the reset pending state 54 to the data transfer ready state 52 , and in the process of doing so resets the entire layer 2 state machine 22 , such as flushing transmission and reception buffers, setting control variables to default values, etc. Communications along channel 11 are in this way reset back to default conditions so as to reestablish normal communications between the first device 20 and the second device 30 . If at any time while the layer 2 interface 22 is in the reset pending state 54 and the layer 2 interface 22 receives a release primitive from the layer 3 interface 23 , the layer 2 interface will transition to the null state 50 . In the process of doing so, the layer 2 interface 22 will close down the channel 11 . Also note that the layer 2 interface 22 may receive a reset control PDU from the layer 2 interface 32 of the second station 30 while in the data transfer ready state 52 . Upon reception of such a layer 2 control PDU, the layer 2 interface 22 will internally reset the layer 2 interface state machine 22 for the channel 11 , and then transmit a reset acknowledgment control PDU to the layer 2 interface 32 . The layer 2 interface 22 remains, however, in the data transfer ready state 52 during this exchange.
The local suspend state 56 is used to temporarily halt the transfer of layer 2 PDUs 22 p along the channel 11 , and is initiated by a suspend-request primitive from the layer 3 interface 23 . The primary purpose of the local suspend state 56 is to ensure a proper ciphering configuration change between the first device 20 and the second device 30 along the channel 11 . At any time while in the data transfer ready state 52 , the layer 2 interface 22 may transition to the local suspend state 56 upon reception of the suspend-request primitive from the layer 3 interface 23 . The suspend-request primitive contains a variable N 56 n , which indicates a sequence number value 43 . While in the local suspend state 56 , the layer 2 interface 22 may transmit along channel 11 layer 2 PDUs 22 p with sequence number values 43 that are sequentially before a value indicated by N 56 n . Any layer 2 PDU 22 p having a sequence number value 43 that is sequentially after the value indicated by N 56 n will not be transmitted by the layer 2 interface 22 p along the channel 11 . Upon reception of a resume primitive from the layer 3 interface 23 , the layer 2 interface 22 will transition from the local suspend state 56 back to the data transfer ready state 52 .
The prior art state models of FIGS. 3 and 4 cannot account for transitions between the local suspend state 56 and the reset pending state 54 , although such transitions are assumed possible. For example, it is not difficult to imagine a situation arising in which, while the layer 2 interface 22 is in the local suspend state 56 , the layer 2 interface 22 detects a communications error along the channel 11 and desires to initiate a reset procedure. Sending a reset control PDU to the second device 30 along the channel 11 would force the layer 2 interface 22 to transition into the reset pending state 54 to await the resulting reset acknowledgment control PDU from the layer 2 interface 32 of the second device 30 . According to the state model of FIG. 3, reception of the reset acknowledgment control PDU should cause the layer 2 interface 22 to transition into the data transfer ready state 52 . This would be incorrect in this situation, however, as the layer 2 interface should more properly return back to the local suspend state 56 . To properly implement the prior art state model, the reset pending state 54 and the local suspend state 56 cannot be “memoryless” states, but must remember from which state they transitioned so as to properly return to that state. Generally speaking, a proper state model should have no hysteresis, i.e., the reaction of a state to inputs should not depend upon past reactions but only upon the present inputs, as this leads to a simpler and more consistent implementation. Internal consistency is essential to avoid programming bugs arising from unexpected state interactions within the model.
SUMMARY OF INVENTION
It is therefore a primary objective of this invention to provide a wireless communications device with a state model having a reset/suspend state to provide internal consistency to the state model, and to avoid previous state memory requirements of the state model.
Briefly summarized, the preferred embodiment of the present invention discloses a wireless communications device that transacts muti-layered communications with a second wireless device. The wireless communications device has a processor, and a program in memory that is executed by the processor to effect a multi-layered communications protocol. The multi-layered communications protocol has a layer 3 interface in communications with a layer 2 interface. The layer 2 interface transmits and receives layer 2 communications data. The layer 2 interface utilizes a null state, a data transfer state, a reset pending state, a local suspend state and a reset/suspend state. While in the null state, the layer 2 interface has no established layer 2 wireless connection with the second wireless device. While in the data transfer state, the layer 2 interface is in wireless communications with a layer 2 interface on the second wireless device and transmits the layer 2 communications data to the layer 2 interface on the second wireless device. The processor switches from the null state to the data transfer state according to an establish primitive from the layer 3 interface, and switches from the data transfer state to the null state according to a release primitive from the layer 3 interface. While in the reset pending state, the layer 2 interface is in wireless communications with the layer 2 interface on the second wireless device and the transmission of the layer 2 communications data is halted. The processor switches from the data transfer state to the reset pending state when a protocol error is found by the layer 2 interface, switches from the reset pending state to the data transfer state according to a reset acknowledge signal received from the second wireless device, and switches from the reset pending state to the null state according to the release primitive from the layer 3 interface. While in the local suspend state, the layer 2 interface is in wireless communications with the layer 2 interface on the second wireless device and halts the transmission of the layer 2 communications data after a predetermined event indicated by the layer 3 interface. The processor switches from the data transfer state to the local suspend state according to a suspend primitive from the layer 3 interface, switches from the local suspend state to the data transfer state according to a resume primitive from the layer 3 interface, and switches from the local suspend state to the null state according to the release primitive from the layer 3 interface. Finally, while in the reset/suspend state, the layer 2 interface is in wireless communications with the layer 2 interface on the second wireless device and the transmission of the layer 2 communications data is halted. The processor switches from the reset/suspend state to the reset pending state according to the resume primitive from the layer 3 interface, switches from the reset pending state to the reset/suspend state according to the suspend primitive from the layer 3 interface, switches from the reset/suspend state to the local suspend state according to the reset acknowledge signal received from the second wireless device, switches from the local suspend state to the reset/suspend state when a protocol error is found by the layer 2 interface, and switches from the reset/suspend state to the null state according to the release primitive from the layer 3 interface.
It is an advantage of the present invention that by providing the reset/suspend state, the state machine of the layer 2 interface requires no memory of previous states when transitioning to subsequent states. The state model is thus more internally consistent, and therefore easier to implement and less likely to be error-prone.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a simplified block diagram of a prior art communications model.
FIG. 2 is simplified block diagram of a layer 2 protocol data unit (PDU).
FIG. 3 depicts a state model for a prior art layer 2 interface when a reset command is performed.
FIG. 4 depicts a state model for a prior art layer 2 interface when a local suspend command is performed.
FIG. 5 illustrates a state model according to the present invention.
FIG. 6 presents a simplified block diagram a wireless communications device that implements the state model depicted in FIG. 5 .
DETAILED DESCRIPTION
In the following description, a wireless communications device may be a mobile telephone, a handheld transceiver, a base station, a personal data assistant (PDA), a computer, or any other device that requires a wireless exchange of data. It should be understood that many means may be used for the physical layer 1 to effect wireless transmissions, and that any such means may be used for the system hereinafter disclosed.
Please refer to FIG. 5 . FIG. 5 depicts a state model 60 for a layer 2 interface of wireless communications device according to the present invention. The state model 60 of the present invention provides a unique reset/suspend state 68 that enables the state model 60 to function based solely on inputs. The state model 60 with the reset/suspend state 68 thus does not require a wireless device to recall a previous state from which a transition occurred when transiting to a subsequent state. Internal consistency is thereby obtained in the present invention state model 60 , with a corresponding easing of program implementation and a reduction of potential errors. A further advantage of the state model 60 is that the state model 60 is fully compatible with the prior art state model and corresponding protocols.
The state model 60 includes, in addition to the reset/suspend state 68 , a null state 61 , a data transfer state 62 , a reset pending state 64 and a local suspend state 66 . Please refer to FIG. 6 with reference to FIG. 5 . FIG. 6 is a simplified block diagram of a wireless communications device 70 according to the present invention, which is capable of effecting multi-layered communications along one or more established channels 78 with a suitable second wireless device 200 . The wireless communications device 70 comprises a processor 74 electrically connected to a transceiver 72 and a memory 76 . The transceiver 72 is used to send and receive wireless signals, the operations of which are controlled by the processor 74 . To control the transceiver 72 , the processor 74 executes in the memory 76 a multi-layered protocol program 80 . The multi-layered protocol program 80 is software that is used to effect a three-tiered communications protocol, which includes a layer 3 interface 83 , a layer 2 interface 82 and a layer 1 interface 81 . Although not shown in FIG. 6, in some embodiments, the layer 1 interface 81 , or portions thereof, may be embedded within the transceiver 72 .
Of particular concern to the present invention is the layer 2 interface 82 , the software implementation of which includes a finite state machine 90 that conforms to the state model 60 , and which is used for communications along a particular channel 78 . That is, each channel 78 has a corresponding finite state machine 90 within the layer 2 interface 82 . For purposes of simplicity in the following description, only one communications channel 78 is considered. During operations, the layer 2 interface 82 has layer 2 communications data 82 d . The communications data 82 d may be layer 3 data that is being processed before being passed to the layer 1 interface 81 for transmission, or may be layer 1 data that is being reassembled before being passed up to the layer 3 interface 83 . The communications data 82 d may also be layer 2 signaling data that is to be sent to, or is received from, a layer 2 interface 202 on the second wireless device 200 .
The finite state machine 90 includes a plurality of state variables 92 that are required to properly implement the layer 2 interface 82 for the channel 78 . An example of such a state variable 92 is VT(S) 92 s , which holds the value of the sequence number (item 43 in FIG. 2) of a layer 2 protocol data unit 82 p that is next to be transmitted. The layer 2 interface 82 also includes a reset procedure 100 that sets the state variables 92 to a default condition. For example, when the wireless communications device 70 is first turned on, the reset procedure 100 is executed to place the layer 2 interface 82 into a default condition, which includes placing a zero into VT(S) 92 s , as the first PDU 82 p to be transmitted along a newly created communications channel 78 should normally have a sequence number 43 of zero.
Initially, the finite state machine 90 is in the null state 61 . While in the null state 61 , the communications channel 78 is not established. This is in contrast to all the other states 62 , 64 , 66 and 68 in which the layer 2 interface 82 is in wireless communications with the layer 2 interface 202 of the second wireless device 200 along an established channel 78 . While in the null state 61 , there is thus no exchanging of layer 2 communications data 82 d with the layer 2 interface 202 . As noted previously with regards to the prior art, the layer 3 interface 83 can send commands (termed primitives) to the layer 2 interface 82 . In particular, upon response to an establish primitive from the layer 3 interface 83 , the layer 2 interface 82 transitions from the null state 61 to the data transfer state 62 . That is, the finite state machine 90 goes from the null state 61 to the data transfer state 62 . In the process of doing so, the layer 2 interface 82 works with the layer 1 interface 81 to establish a communications channel 78 with the layer 2 interface 202 on the second wireless device 200 . The reset procedure 100 is also executed so as to place the state variables 92 for the new channel 78 into a default state. If at any time while in the data transfer state 62 the layer 2 interface 82 receives a release primitive from the layer 3 interface 83 for the channel 78 , the finite state machine 90 will transition from the data transfer state 62 back to the null state 61 . In the process of doing so, the finite state machine 90 shuts down the associated communications channel 78 .
During communications with the second wireless device 200 and while the finite state machine 90 is in the data transfer state 62 , the layer 2 interface 82 may determine that communications along the channel 78 are disrupted and that the channel 78 needs to be reset. The layer 2 interface 82 composes a layer 2 reset control PDU 82 r , which is a layer 2 signaling PDU exchanged between the layer 2 interfaces 82 and 202 , to reset the channel 78 . The finite state machine 90 causes the reset control PDU 82 r to be sent to the layer 2 interface 202 , and then the finite state machine 90 transitions to the reset pending state 64 . While the finite state machine 90 is in the reset pending state 64 , the layer 2 interface 82 transmits no layer 2 communications data 82 d along the channel 78 . Other channels may be established with the second wireless device 200 over which layer 2 communications data 82 d may be sent, but no communications data 82 d is sent along the channel 78 whose corresponding finite state machine 90 is in the reset pending state 64 . Upon reception of a reset acknowledge PDU 82 a from the second wireless device 200 , the finite state machine 90 executes the reset procedure 100 , and then transitions from the reset pending state 64 back to the data transfer state 62 . Like the reset control PDU 82 r , the reset acknowledge PDU 82 a is a type of layer 2 signaling PDU. It is also possible for the wireless communications device 70 to receive a reset control PDU 82 r from the second wireless device 200 . If the finite state machine 90 is in the data transfer state 62 , upon reception of the reset control PDU 82 r from the layer 2 interface 202 , the finite state machine 90 sends a reset acknowledge PDU 82 a to the layer 2 interface 202 , and then executes the reset procedure 200 to reset the state variables 92 of the channel 78 . The finite state machine 90 remains, however, in the data transfer state 62 . Similarly, if the finite state machine 90 receives a reset control PDU 82 r from the layer 2 interface 202 while in the reset pending state 64 , the finite state machine 90 will respond by sending a reset acknowledge PDU 82 a to the layer 2 interface 202 . For the sake of consistency, the finite state machine 64 should also probably execute the reset procedure 100 , though this is not totally necessary as this will happen upon the transition back to the data transfer state 62 . In the meantime, the finite state machine remains in the reset pending state 64 . As with the data transfer state 62 , if the finite state machine 90 receives a release primitive from the layer 3 interface 83 while in the reset pending state 64 , the finite state machine 90 will transition to the null state 61 , and in the process of doing so shut down the corresponding communications channel 78 .
It is also possible to temporarily halt layer 2 communications along the channel 78 . This is usually done when changing the ciphering configuration of the channel 78 . Ciphering is performed utilizing the sequence number 43 (of FIG. 2) of each individual layer 2 PDU 82 p . A new ciphering configuration is used for PDUs 82 x that have sequence number values 43 that are sequentially after an activation value 83 a . To ensure proper communications along the channel 78 , it is necessary that both the wireless communications device 70 and the second wireless device 200 agree upon the new ciphering configuration. Communications along the channel 78 are thus suspended for all PDUs 82 x whose sequence number values 43 exceed the activation value 83 a , and remains suspended until the wireless communications device 70 is assured that proper ciphering synchronization exists with the second wireless device 200 . This is the primary purpose of the local suspend state 66 . Ciphering is controlled by the layer 3 interface 83 , and so it is the layer 3 interface 83 that sends a suspend primitive to the finite state machine 90 . The suspend primitive indicates the activation value 83 a to the finite state machine 90 . Upon reception of the suspend primitive, the finite state machine 90 transitions from the data transfer state 62 to the local suspend state 66 , and responds to the suspend primitive by passing a suspend confirmation message to the layer 3 interface 83 . While in the local suspend state 66 , the finite state machine 90 transmits along channel 78 any layer 2 PDUs 82 p that have sequence number values 43 that are sequentially before the activation value 83 a , using the old ciphering configuration. PDUs 82 x having sequence number values 43 that are sequentially after the activation value 83 a are not transmitted. Transmission along the channel 78 is thus suspended after an event indicated by the layer 3 interface 83 , i.e., the activation value 83 a . Upon reception of a resume primitive from the layer 3 interface 83 , the finite state machine 90 transitions back to the data transfer state 62 from the local suspend state 66 . As with both the reset pending state 64 and the data transfer state 62 , upon reception of the release primitive from the layer 3 interface 83 , the finite state machine 90 transitions into the null state 61 from the local suspend state 66 , terminating the associated channel 78 in the process.
The reset/suspend state 68 exists for those rare situations in which the finite state machine 90 is both suspended, as per the local suspend state 66 , and awaiting a reset acknowledge PDU 82 a along the associated channel 78 from the second wireless device 200 . This may occur when the finite state machine 90 determines that the communications channel 78 is to be reset while in the local suspend state 66 , or when the layer 3 interface 83 issues a suspend primitive while the finite state machine 90 is in the reset pending state 64 . The reset/suspend state 68 is similar to the reset pending state 64 in that no layer 2 communications data 82 d is transmitted by the wireless communications device 70 along the channel 78 while the associated finite state machine 90 is in the reset/suspend state 68 . The finite state machine 90 will transition into the reset/suspend state 68 from the reset pending state 64 on reception of a suspend primitive from the layer 3 interface 83 . In this transition, the finite state machine 90 responds to the suspend primitive with a suspend confirmation message to the layer 3 interface 83 , analogous to state transitions between the data transfer state 62 and the local suspend state 66 . Alternatively, the finite state machine 90 will transition into the reset/suspend state 68 from the local suspend state 66 upon determination that the channel 78 needs to be reset because protocol errors are detected by the layer 2 interface 82 on the channel 78 . Under this transition, the finite state machine 90 sends a reset command PDU 82 r to the second wireless device 200 , and then transitions into the reset/suspend state 68 . Transitioning out of the reset/suspend state 68 depends only upon the external inputs into the finite state machine 90 , i.e., primitives received from the layer 3 interface 83 , or layer 2 signaling PDUs from the layer 2 interface 202 of the second wireless device 200 . The finite state machine 90 is not required to recall a previous state in order to transition to a subsequent state. While in the reset/suspend state 68 , the finite state machine 90 will transition to the reset pending state 64 upon receiving a resume primitive from the layer 3 interface 83 . Or, the finite state machine 90 will transition from the reset/suspend state 68 to the local suspend state 66 upon reception of a reset acknowledge PDU 82 a along the associated channel 78 from the second wireless device 200 , and consequently causing the reset procedure 100 to be executed to reset the channel 78 . As with all the other states in which an established channel 78 exists, the finite state machine 90 will transition into the null state 61 from the reset/suspend state 68 upon reception of a release primitive from the layer 3 interface 83 , terminating the associated channel 78 in the process.
In contrast to the prior art, the present invention provides a wireless communications device with a finite state machine that has a unique reset/suspend state. The reset/suspend state is used to explicitly support those conditions in which both a channel reset and a channel suspend operation are being simultaneously performed. The reset/suspend state enables the finite state machine to operate in a “state memoryless” condition, in that the finite state machine is not required to recall a previous state in order to determine transitions to a next state from a current state. The reset/suspend state thus provides a more consistent state machine design, and is consequently less likely to suffer from errors in implementation.
Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
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A wireless communications device has a layer 2 interface that is designed as a finite state machine. The finite state machine includes a null state, a data transfer state, a reset pending state, a local suspend state and a reset/suspend state. In the null state, no communications channel is established. In all the other states, a communications channel is established with another communications device. In the data transfer state the communications channel is active. In the reset pending state communications is halted pending a reset acknowledge signal from the other device. In the local suspend state communications are temporarily suspended for all data after a predetermined event. The reset/suspend state explicitly supports the condition in which both rest pending and local suspend conditions are present, and enables the state machine to transition to a subsequent state without requiring knowledge of a previous state.
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BACKGROUND OF THE INVENTION
In shuttleless looms and more particularly in those looms in which weft yarn is supplied from a stationary source located outside of the lateral limits of the warp yarns, it is customary to insert each pick of weft by means of a reciprocating carrier or carriers which are mounted on inserters. In a common type of shuttleless operation, a supply of weft is located adjacent the right hand side of the loom and each pick is drawn from the source and inserted into the shed formed between the warp yarns. Insertion is initiated by means of an inserter on the right hand side of the loom, this inserting carrier moving the yarn to approximately the midpoint between the two sides of the loom. At the time the end of the weft yarn arrives at the middle of the warp shed, a carrier mounted on an inserter located on the left hand side of the loom grips the end of the yarn and pulls it the remainder of the distance across the loom. This type of insertion is commonly referred to as the Dewas or gripper insertion system since the extending carrier actually grips or clamps the end of the yarn to be drawn through the warp shed.
When utilizing this system of weft yarn insertion, it is obvious that consistent and accurate transfer of the weft must be made between the inserting and extending carriers. In the past, a high degree of reliability has been accomplished by utilizing comparatively large, relatively heavy, cast inserters and while these inserters did perform reliably, they were expensive to manufacture and difficult to replace when replacement became necessary due to accident or wear.
It is a principle object of this invention to provide an improved extending carrier which is both simplier and cheaper to manufacture and which can be replaced expeditiously.
A further object of this invention is to provide an extending carrier which is produced solely from plastically deformed non-cast parts.
An additional object of this invention is to provide an improved extending carrier in which the gripping pressure between gripping elements can be readily adjusted.
Other object and advantages of this invention will be in part obvious and in part explained by reference to the accompanying specification and drawings in which:
FIG. 1 is an exploded perspective view of a carrier constructed in accordance with this invention and attached to the end of an inserter;
FIG. 2 is a top elevation of the inserter shown gripping a weft yarn;
FIG. 3 is a fragmented perspective view of the end of the carrier of this invention and showing a phantom view of the inserting carrier as it presents the yarn to the extending carrier; and
FIG. 4 is a top elevation showing the inserter and extending carrier removed to the left hand side of the loom where release of the end of the weft yarn is effected.
DESCRIPTION OF THE INVENTION
For a better understanding of the invention, reference is made to the drawings and particularly to FIG. 1 wherein an improved extending carrier 10 is shown mounted on or connected to the end of a reciprocating inserter 11. In this case, inserter 11 is shown as a broad, flat, flexible, band-like element which can be wrapped around a tape wheel located on the side of the loom, in a manner which is well known in the industry. Obviously, the type of inserter which is used to move the carrier 10 into and from the warp shed is not important since any type of inserter, either flexible or rigid, that is known in the prior art would be equally effective.
The carrier 10 comprises a main body portion 12 which is made up of a flat horizontal web portion 13 and a vertical web portion 14 which extends upwardly from horizontal web 13. It will be seen that the horizontal web portion 13 has a relatively wider dimension 13a on the end which overlays inserter 11 and a relatively narrower dimension 13b which is located beyond the outer end of inserter 11. Similarly, the vertical web portion 14 which extends upwardly from web portion 13 has a relatively wider portion 14a which is adjacent horizontal web portion 13a and a relatively narrower vertical dimension 14b which is also located beyond the outer end of inserter 11 as is narrower dimension 13b.
Carrier 10 also includes flexible gripper means whereby yarn that has been inserted into the warp shed by the inserting carrier can be engaged and extended to the other side of the loom. This gripper means comprises an elongated flexible element 20 which on its outer or left hand end as viewed in FIG. 1 has means for directing and engaging the yarn. The yarn directing and engaging means includes a downwardly and outwardly yarn engaging surface 21 and an outwardly and rearwardly extending yarn hook 22. The flexible body or gripper means 20 has on its other end a pair of raised ears 23 which are provided with internally threaded holes 24. The flexible gripper 20 is secured to the vertically extending web 14 by means of threaded fasteners 25 and 26 each of which extends through the openings 27 and 28 located in web 14 for threadably engaging threads provided on the interior of holes 24. Each of the threaded fasteners 25 and 26 extends completely through holes 24 to engage the locking nuts 29 and 30 respectively. That is, when fasteners 25 and 26 are threaded through the openings 24, the nuts 29 and 30 will be threadably received on the portion which extends beyond the outer surface of member 20 so that fasteners 25 and 26 cannot loosen during operation. One final element which is provided is the biasing spring 31 that is located between the head of threaded fastener 25 and the outer surface of vertical web 14. The presence of this spring permits through adjustment of fastener 25 and nut 29 a change in the force that is necessary to separate the outer end of vertical web 14 from the outer end of the resilient gripping member 20.
In the vertical elevation shown in FIG. 2, the carrier is shown in its assembled position mounted on inserter 11 and showing a piece of yarn 35 being gripped between the cooperating inner surfaces of vertical web 14 and gripping member 20.
In operation, yarn is withdrawn from a yarn package located outside of the lateral limits of the warp by means of an inserter carrier. In FIG. 3 there is shown in phantom an inserter carrier 36 in which yarn 35 extends from the slot 37 across the width of carrier 36 (indicated by numeral 38) and then out the generally horizontal slot 39 which is located on the back wall of the inserter carrier. When inserter carrier 36 reaches the midpoint of the loom, carrier 10 has moved into carrier 36 as indicated in FIG. 3. It can be seen that the outer end of the extending carrier has moved beyond the horizontal length of yarn located between slots 37 and 39 so that the yarn has come into contact with the yarn engaging surface 21. After the carrier has overlapped to this extent, reverse movement is effected so that the yarn 35 is moved outwardly and downwardly along surface 21 and is directed in toward the contacting surfaces of vertical web 14 and gripper 20 by means of yarn hook 22. Continued movement of gripper 10 toward the left hand edge of the warp continues until, referring to FIG. 4, the head of threaded fastener 25 contacts cam surface 45 of the inserter guide 46. When threaded fastener 25 moves down cam surface 45, it will cause the resilient gripper 20 to be moved away from vertical web portion 14 and thereby release the end of yarn 35.
It will be noted that the extending carrier 10 is constructed entirely of components that have been plastically deformed to achieve the desired configuration. That is, the carrier can be constructed entirely of sheet metal parts that are simply deformed to the desired shapes. This is a significant difference from carriers known in the prior art since previous construction has been effected by casting and then machining to final configuration. This carrier is simple and the gripping pressure can be readily adjusted to accommodate its applicability to use in configuration with a variety of yarns.
Although the present invention has been described in connection with a preferred embodiment, it should be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims.
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An improved weft yarn insertion carrier made entirely of non-cast components which includes an elongated main body made up of horizontal and vertical webs, flexible gripper means attached to the vertical web of the main body and means for adjusting the gripping pressure exerted between the flexible gripper and the main body portion.
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FIELD OF THE INVENTION AND RELATED ART STATEMENT
This invention relates to a fixture for a prestressed concrete, and more particularly to an anchoring device for a tension wire or rod of a prestressed concrete which is improved so as to possess notably enhanced corrosion-proofness and durability.
As widely known, the prestressed concrete is a concrete product which has a compressive load applied in advance thereto.
As a means of applying the compressive load to a concrete, there is prevailing a method which comprises forming through holes in the longitudinal direction in the concrete, inserting wires or bars of steel, for example, through the through holes, imparting tension to the wires, and thereafter fastening the opposite ends of the wires to the opposite ends of the concrete with the aid of fixtures.
The structures or constructions of these fixtures are greatly varied in kind. Since they require high strength, steel is extensively utilized as the material therefor.
The fixtures made of steel retain durability fairly in a normal working environment. In a highly corrosive environment, however, they gather rust and suffer degeneration of their own strength. The rust so produced accelerates deterioration of the portions of concrete directly surrounding the coats of rust growing on the fixtures. (For example, since the fixtures undergo a voluminal expansion during the growth of this rust, the voluminal expansion inevitably causes the concrete to sustain fine cracks.)
When the conventional prestressed concrete is used in marine structures or structures located near seashores, therefore, it is liable to entail the drawback of relatively quickly losing the internal stress.
As one measure for relief from the drawback, adoption of fixtures made of stainless steel has been conceived to materialize notable improvement in durability. These fixtures of improved durability, however, betray their lack of sufficient corrosion-proofness in environments susceptible of the adverse actions of salt sea breeze.
OBJECT AND SUMMARY OF THE INVENTION
An object of this invention is to provide a fixture for prestressed concrete which possesses extremely high strength and excels in corrosion-proofness.
Another object of this invention is to provide a fixture for prestressed concrete which can be stably used for a long time even in a highly corrosive environment.
The fixture of the present invention for prestressed concrete is produced by combining a thermosetting synthetic resin as a binder and glass fibers or carbon fibers as reinforcing fibers and molding the resulting mixture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view illustrating a typical fixture contemplated by the present invention.
FIG. 2 is a cross section taken along the line II--II in FIG. 1.
FIG. 3 is a plan view illustrating another typical fixture according to the present invention.
FIG. 4 is a side view of the fixture of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, the present invention will be described more specifically below.
Desirably the thermosetting synthetic resin usable in the present invention yields sparingly to deformation due to external stress and excels in weatherability and chemical resistance. As concrete examples of the thermosetting synthetic resin answering the description, there can be cited epoxy acrylate resin, phenol resin, amino resin, and polyester resin.
As reinforcing fibers, there are used glass fibers and carbon fibers.
Suitably, the glass fibers have diameters approximately in the range of 10 to 20 μm. In terms of form, they may be a roving or chopped strands.
The carbon fibers suitably have diameters approximately in the range of 5 to 10 μm. In terms of linear dimension, they may be short-staple fibers or long-staple fibers which is selected due to the occasion.
If the glass fibers and the carbon fibers have diameters smaller than the respective ranges mentioned above, they cost much. If they have diameters larger than the ranges, they are deficient in flexibility. If they have lengths greater than the respective ranges mentioned above, it tends to intertwine during the course of production and renders homogeneous distribution in the mixture less easy. If they have lengths smaller than the ranges, they produces an insufficient reinforcing effect.
The ratio of the glass fibers to the carbon fibers is desired to fall approximately in the range of 2:1 to 1:1. The ratio of the total amount of the glass fibers and the carbon fibers to the amount of the aforementioned thermosetting synthetic resin desirably falls approximately in the range of 85:15 to 60:40. When the mixing ratio is selected in this range, the shaped article of resin consequently obtained is allowed to acquire very high strength.
The present invention tolerates the thermosetting synthetic resin incorporating therein pigment and powdered filler to the extent of not impairing strength thereof.
One concrete example of the fixture to which the present invention can be applied is illustrated in FIG. 1 and FIG. 2. In FIG. 1 and FIG. 2, the reference numeral 1 denotes an outer cone possessing a tapered inner hole. The reference numeral 2 denotes an inner cone of the shape of a truncated cone fitting in the inner hole. This inner cone 2 possesses a central hole of a uniform diameter. The inner cone 2 is equally divided into three wedges 2a, 2b, and 2c. A wire 3 is inserted through the central hole of the inner cone 2. Slipping possibility of the wire 3 in the central hole is prevented by the tightening force of the wedges 2a, 2b, and 2c. Thus, the wire is secured in place.
The present invention can also be applied to a fixture of the kind illustrated in FIG. 3 and FIG. 4. FIG. 3 is a plan view illustrating an inner cone of the fixture for allowing seven wires to pass and to be held therein. In this fixture, the inner cone is divided equally into six wedges 4a through 4f. Grooves for passing wires are dug into the adjoining surfaces of these wedges. The wires are passed through these grooves 5 and the central hole of the inner cone and secured in place.
This fixture is fitted in the outer cone 1 as illustrated in FIG. 4.
In addition to the fixtures constructed as illustrated in the diagrams, the present invention can be applied to various fixtures such as those proposed by Hochtief, Bilfinger, Held u. Franke, Moraudi, and Bauwens in the Handbook of Prestress Concrete.
The shaped article of resin contemplated by this invention can be produced by any of the conventional methods. For example, it can be easily produced by the filament winding method. Alternately, it may be obtained by alternately superposing cloths of glass fibers and cloths of carbon fibers, impregnating the resulting pile with the thermosetting synthetic resin, and molding the impregnated pile. When this molding is effected by the compression molding technique, the shaped article consequently obtained is allowed to acquire notably high strength.
Further, when the shaped article is obtained by the lamination technique using cloths of fibers, the surfaces of the fixture for contact with the bracing wires have a pattern of superposed cloths and exhibit a very high coefficient of friction, making the prevention of slip of wires all the more certain.
Now, the fixture of the present invention will be described below with reference to working examples.
The fixture illustrated in FIG. 1 and FIG. 2 was manufactured by the following procedure.
PRODUCTION OF OUTER CONE
With a stirrer, 20 parts of epoxy acrylate resin (produced by Showa Highpolymer Co., Ltd. and marketed under trademark designation of Riboxy), 0.2 part of a curing agent, 1 part of pigment, 1 part of silica (invariably by weight) were stirred. In a filament winding machine, 50 parts of glass fibers and 30 parts of carbon fibers were impregnated with the aforementioned resin mixture and wound in a roll until a fixed thickness. The resultant roll was removed from the winding machine and then left standing in a constant temperature bath at 100° to 110° C. for one hour and in another constant temperature bath at 150° to 160° C. for three hours to be solidified. The hard cylinder consequently obtained roughly measured 40 mm in outside diameter, 60 mm in length, and 16 mm in smallest inner diameter. The inner hole had an inclination of 15°.
PRODUCTION OF INNER CONE
With a stirrer, 20 parts of epoxy acrylate resin (produced by Showa Highpolymer Co., Ltd. and marketed under trademark designation of Riboxy), 0.2 part of a curing agent, 1 part of pigment, 30 parts of calcium carbonate, and 0.5 part of magnesium oxide (invariably by weight) were stirred. A cloth of glass fibers and a cloth of carbon fibers were impregnated with the resin mixture obtained above and left standing in a constant temperature bath at 40° C. for 24 hours to produce prepregs having a fiber content of about 50%. The prepregs were cut in a prescribed size. The cut cloths of glass fibers and those of carbon fibers were alternately superposed. The pile was placed in a mold and pressed therein at 150° to 170° C. for three minutes to be solidified.
The fixture obtained in this case, when wires secured therein were drawn, showed breaking strength exceeding 10 tons.
As is clear from the foregoing description, the fixture of the present invention possesses higher strength and far better durability than the conventional fixture made of steel.
In marine structures and structures installed near seashores which are inevitably exposed to a highly corrosive environment, therefore, the fixture of this invention can be stably used for a very long period.
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An anchoring device for prestressed concrete. The anchor is made of an outer member which has an inner hole with a cone shaped surface and an inner member which is made up of a plurality of wedges having at least one hole for holding a tension member. Both the inner member and the outer member are made by alternately superposing cloths of glass fibers and carbon fibers; impregnating the cloths with a resin and curing the resin.
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BACKGROUND OF THE INVENTION
The present invention is directed to general purpose dollies for use in warehousing, trucking and storage operations wherein large numbers of dollies of similar design can be stacked to facilitate the transportation of unused dollies throughout a warehouse, truck or job site facility and to enable such dollies to be stored efficiently with minimal utilization of available space.
The dollies as disclosed herein can be of a number of different designs so long as the teachings of the present disclosure are utilized to enable the dollies to be placed in stacked engagement with one another.
Typically in warehousing and storage facilities, space is critical with the storage efficiency of the facility being an important factor of profitability. Warehousing and storage facilities can be improved where dollies are stacked efficiently, thus appreciably reducing storage space.
Numerous patents deal with the problem of stacking dollies and carts. For example, see U.S. Pat. Nos. 3,689,098; 3,698,733; 3,523,694; and 2,862,720.
Various designs have been attempted in which portions of each successive dolly mate with the next. For example, in U.S. Pat. No. 5,445,396, the wheels of each dolly fit into indentations in the dolly below, as such dollies are stacked.
Further, U.S. Pat. No. 3,633,774 utilizes holes used with relation to caster sets that serve a mating function.
However, none of the dollies of the prior art references stack with the compactness of the present invention, which is enabled by a rotational placement of the dollies so as to prevent rollers of the dollies from interfering with the stacking.
It is therefore a primary object of the present invention to provide dollies which can be stacked utilizing a minimum of space in such stacking.
It is another object of the present invention to accomplish such stacking while nevertheless ensuring the stability of the stacked dollies.
It is yet another object in ensuring stability to provide a design in which a stacking concept is easily understood and can be implemented quickly by warehouse and trucking employees.
It is a further object of the present invention to allow stacking in such manner that maneuverability of stacks is not interfered with and relatively high stacks can be pushed with relative ease to locations throughout the warehouse, truck, job site or storage facility.
It is but another object to provide dolly design where physical handling of the dolly is facilitated by improved carrying means.
SUMMARY OF THE INVENTION
The present invention enables dollies to be stacked to very high heights as the invention enables the creation of a secure engagement between stacked dollies with perfectly level stacking.
Each dolly is provided with a unique platform from which extends outwardly tab-like legs which typically would number three or four on a conventional dolly. Each of the tab-like legs has a roller or caster member depending downwardly therefrom to enable the dolly to be supported by the rollers or casters which of course need to be strong and balanced adequately so that the dolly will be able to support large loads.
As taught by the subject invention, each dolly will have mating configurations of protrusions and indentations which are designed to engage similar dollies above and below as such dollies are stacked.
In the preferred embodiment, each dolly will have protrusions on the base side of its platform, which protrusions extend downwardly at selected locations. Further, each dolly's top surface will have indentations or holes to receive protrusions which will be depending downward from the dolly above as it is positioned in stacking relationship.
The protrusions may be placed in relative proximity to the tab-like legs sticking outwardly from the platform. With respect to the indentations or holes placed on the top of each platform, such holes are not placed in the same close proximity to the tab-like legs, but rather are positioned at a rotational distance from the legs (and protrusions). For example, the holes may be 30° off-center from an axis drawn from the center of the platform through the center of the nearest tab-like leg. Other acceptable rotational distances may be used also, such as 221/2° or 24°.
As successive dollies are mounted, each protrusion of the next highest dolly will be mated with the hole in the top of the lower platform. To accomplish this, the dolly being placed atop the lower dolly must be rotated so that each of its legs and rollers are positioned off-center from the lower dolly corresponding leg and roller. In this manner each leg of the next highest dolly will be rotationally turned, as for example 30°, in a preferred embodiment. In this manner, the rollers of each dolly (stack) are not directly above the rollers of the next lowest dolly so as to provide clearance with respect to dollies below and above each particular dolly.
Each sequence of positioning will repeat so that the rollers of one dolly will be above rollers of a lower dolly in the stack such that the rollers impact against the top of the legs to provide additional stability and balance in the repeat sequence.
For example, as in the preferred embodiment, if each dolly has four equally spaced legs (and four rollers, one depending from each leg), each dolly will be provided with four protrusions extending downwardly from the platform in the proximity of each leg. Each dolly will also be provided with four indentations or holes, each spaced approximately 30° rotationally off of a line from the center of the dolly bisecting the center of the nearest leg. Placement of one dolly above the lower will be made so that protrusions of the upper engage with holes of the lower, thereby causing the upper dolly legs to be rotated 30° from the nearest lower dolly legs. As the next dolly is placed, the third dolly legs will be 60° from the first dolly. When the next dolly is positioned, its legs will be 90° from the first dolly leg which will bring the leg of the fourth dolly directly over the next succeeding leg of the first dolly, each dolly having four legs equally positioned at 90° one from the next. In this position of a 90° repeat, the dolly rollers will also rest on top of the leg below so that more stability will occur with the stacking.
Thus, dollies can be positioned with platforms closer to one another than would otherwise be possible.
Cut-away portions have been made in each of the dollies to provide convenient off-set handles for carrying the dollies vertically as well as a center handle to provide horizontal balancing as each dolly is stacked.
For a better understanding of the present invention together with objects thereof, reference is made to the following description taken in connection with the accompanied drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a number of dollies in stacked relationship;
FIG. 2 is a perspective view showing four dollies in rotational relationship one to the others with such dollies being positioned so as to be placed in stacking relationship;
FIG. 2A is a front plan view of the stack as shown in FIG. 1;
FIG. 3 is a perspective view of a single dolly as disclosed in an alternative embodiment whereby three legs and rollers are used instead of the four rollers of the preferred embodiment shown in FIGS. 1 and 2.
FIG. 4 shows a perspective view of a protrusion to be used with the embodiment of FIGS. 1-2;
FIG. 5 shows a plan view showing a roller depending from a leg next to which is mounted a protrusion extending downwardly from the platform;
FIG. 6 shows a cut-out pattern of cushioning material to be mounted as shown in FIG. 5;
FIG. 7 shows a bottom view of a leg on which the roller has been mounted such that the cushioning material is tucked and secured on the bottom of said leg;
FIG. 8 shows an elevational view of a dolly being gripped as it is carried; and
FIG. 9 shows the dolly of FIG. 8 being grasped as it is stacked.
DETAILED DESCRIPTION
With reference to FIG. 1, multiple dollies are shown stacked in accordance with the teachings of the subject invention. To assist in understanding the stacking function, attention is directed to FIG. 2 wherein four dollies A-D are shown positioned apart one from another but in stacking alignment. Each dolly 10 is shown to include a platform 12 from which extends four tab-like legs 14. Each tab-like leg 14 is covered with cushioning material 16 which may be carpet or rubber. From each leg 14 a roller assembly 18 depends downwardly.
The platform 12 may have cut-away portions 20 which serve to lighten the weight of the dollies 10 without sacrificing the structural integrity of the dollies 10. The cut-away portions 20 also serve to provide handles which will be explained subsequently in the discussion with respect to FIGS. 8 and 9.
Each platform 12 has four protrusions 22 as best seen from viewing dolly A at the top of the series. As seen conveniently from dolly B, each platform 12 has mating holes 24 which are of a size appropriate to receive at least a portion of protrusions 22 from another dolly which will be positioned immediately above in stacking relationship.
Attention is next directed to dolly D of FIG. 2 which will be the lower-most dolly in a four dolly stack as each of the dollies 10 is lowered onto the one below in FIG. 2.
In observing dolly D it will be appreciated that each protrusion 22 is mounted in close proximity with one of the roller assemblies 18 depending from legs 14. The protrusions 22 may be placed substantially in a line from the center point of the platform through a center line of leg 14. It will be appreciated that the legs 14 are each 90° rotationally distant from the next leg 14.
Holes 24 are positioned rotationally at a distance from the location of the nearest protrusion 22. In the embodiment shown in FIG. 2, this rotational distance is approximately 30°. Thus one can appreciate as dolly C is lowered on dolly D for the protrusions of dolly C to align with the holes of dolly D, the legs 14 of dolly C will be rotationally off-set some 30° from the corresponding legs 14 of dolly D.
As dolly B is then aligned with and lowered to engage with dolly C, the dolly B legs will be 30° rotationally off-set from the dolly C legs and some 60° offset from the dolly D legs 14.
Finally, as dolly A is lowered on dolly B, the dolly A legs 14 will be 30° offset from the dolly B legs 14, some 60° offset from the dolly C legs 14 and 90° offset from the dolly D legs 14, which in turn places the dolly A legs 14 directly over a dolly D legs 14. In the preferred embodiment, rollers 18 of dolly A will rest on the top of dolly D legs 14 to provide stacking stability.
Turning to FIGS. 1 and 2A, the relationship of the stacked dollies can be quickly appreciated as each dolly 10 is engaged with the dolly 10 below as its legs 14 and roller assemblies 18 are rotated some 30° from the dolly legs 14 of the lower dolly 10.
With respect to FIG. 3, an alternative embodiment is shown as each dolly 30 has a platform 32 similar to the embodiment in FIG. 2, however, each dolly 30 will have three legs 34 instead of four, as in the embodiment of FIG. 2.
In the embodiment of FIG. 3, the legs 34 are positioned 120° from one another with each dolly 30 having a roller assembly 36 and protrusion 38 corresponding with each leg 34. Further there is a hole 40 associated with each leg 34 but rotationally off-set approximately 30° as in the embodiment of FIG. 2.
The dollies 30 of FIG. 3 will be stacked in the same manner as those in FIG. 2 with protrusions 38 engaging holes 40 in the dolly below as the dollies are stacked. Thus, as in FIG. 2, each dolly leg 34 (and roller assembly 36) will be rotated approximately 30° from a corresponding dolly leg 34 and roller assembly 36 below.
It will be appreciated that the repeat sequence (legs over other legs) is different between FIG. 2 and FIG. 3 as legs are approximately 30° apart when stacked in each embodiment so that a repeat will occur every 90° in FIG. 2, and every 120° in FIG. 3. Whereas the fourth dolly will be in an overlapping position (legs over legs) in FIG. 2, it will be the fifth dolly in FIG. 3.
With respect to FIG. 4, a protrusion 22 is shown having shoulders 40 which are tapered from a broad portion at the top 42 down to a narrower part at the lower portion 44 of the protrusion. A bore 46 is designed to receive a mounting screw 48 as shown in FIG. 6 by which the protrusion 22 is mounted to the platform.
It will be appreciated that the lower portion 44 of the protrusion 22 will fit in the corresponding hole 24 while the upper portion 42 acts as a buffer area or space between succeeding platforms 12.
The protrusion 22 of FIG. 4 is to be sized properly as it must be recognized there is a relationship between protrusion 22 and the desired space between stacked dollies to enable the properly repeating sequences. For example, in FIG. 3, the repeating sequence is every fifth dolly and accordingly the distance between each dolly need not be as great as the repeat will not occur until five dollies are stacked versus four dollies in FIG. 2. Accordingly, the size of protrusion 38 for the embodiment of FIG. 3, or at least the portion of the upper shoulder 42 which becomes the effective distance from one dolly to the next may be smaller than the corresponding shoulders 42 where the protrusion 22 is to be used with the embodiment of FIG. 1 and FIG. 2.
Turning to FIGS. 5, 6 and 7, details of the mounting of the protrusions 22, 38 and roller assemblies 18, 36 is shown. Thus as seen in FIG. 5, bolt 48 engages the protrusion structure 22, 38 to mount said protrusion 22, 38 downwardly from the bottom of the platform 12, 32. Cushioning material 50 which may be carpet may be used for its friction enhancing abilities as well as its cushioning effect and can be cut out as shown in the pattern of FIG. 6. Slots 52 may be cut into the pattern which will accommodate mounting bolts 54 which are shown to mount roller assembly 18, 36 to the leg 14, 34 as shown in FIG. 7. As can be appreciated from viewing FIGS. 5, 6 and 7, the carpet 50 is folded over the leg 14, 34 and secured on the bottom as roller assembly 18, 36 is mounted. The roller assembly 18, 36 which is a standard off-the-shelf item, comprises a wheel, or caster 58 secured by axle 60 to frame 62. The frame 62 is free to rotate around vertical axle 64 as rotationally secured to base plate 66.
Folds of carpet 50 of FIG. 6 are tucked and positioned under base plate 66 which is mounted by bolts 54 into the bottom of the legs 14, 34, thus securing the carpet 50 under the roller assembly 18, 34. Staples, not shown, may also be used to secure the carpet 50.
As shown in FIG. 8, the dolly 10 may be conveniently carried vertically by using edge 70 of the cut-away portion 20 as an offset handle.
As shown in FIG. 9, the dolly 10 may be balanced horizontally as it is stacked as the holder grips handle 72 that is formed between the two cut-out portions 20.
Utilizing the techniques of the subject invention, dollies 10 have been designed which can be conveniently handled in all aspects of warehousing or trucking operations. When not in use, the dollies may be easily yet securely stacked for storage or movement in a stack within the facility.
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A stacking dolly system where each dolly comprises a central platform with outwardly projecting legs having downwardly depending rollers. Through the use of mating protrusions and indentations, successive dollies are brought to an engagement position with one another. Large numbers of dollies can be stacked to aid in warehousing, trucking and handling functions.
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BACKGROUND OF THE INVENTION
[0001] The invention is directed to a method for estimating hidden channel parameters, specifically the delay, the amplitude and the phase of a GNSS navigation signal received in a dynamic multipath environment, using a sequential estimation by means of a recursive Bayesian filtering which starts from the likelihood value of the measured channel output signal and updates the value using a state transition model.
DESCRIPTION OF RELATED ART
[0002] For a continuous estimation of the propagation time and the phase of an incoming signal, which are both variable in time due to the movement of a satellite and a receiver, a navigation receiver usually uses a combination of two control loops supporting each other. The so-called phase-lock-loop (PLL) for the control of the carrier phase is used to guarantee coherence with the received signal and to allow for a representation in the baseband.
[0003] The so-called delay-lock-loop (DLL) synchronizes the received baseband signal with a locally simulated reference signal by maximizing their cross-correlation. A constant tracking of the maximum for the maintenance of the synchronization is achieved by corresponding shiftings of the reference signal from which the propagation time of the signal from the satellite to the receiver can be determined. The receiver will then calculate its own position from the propagation times of the signals from at least four satellites.
[0004] In practice, this combination of DLL and PLL proves to be a robust realization of an almost optimal propagation time estimation device when there is no multipath propagation of the signals. If, however, the received signal is formed by a superposition of individual paths, which mainly occurs due to the transmitted signal being reflected or diffracted from objects in the vicinity of the receiver, the DLL will provide an erroneous estimation, which has an immediate effect on the precision of the position result. Multipath propagations, i.e. the reception of additional signal replicas due to reflections, which introduce a deviation into the estimated value of the delay-lock-loop (DLL) of a conventional navigation receiver, thus represent a significant source of errors within GNSS systems.
[0005] Of the known signal processing methods for reducing the multipath error, most are based on more or less immediate modifications of the conventional DLL, aiming at reducing the influence of the additional paths as much as possible, i.e. to suppress this influence, as it were.
[0006] Besides the presumably most simple variant, the so-called “narrow correlator” [A. van Dierendonck, P. Fenton, T. Ford: “Theory and Performance of Narrow Correlator Spacing in a GPS Receiver” in Proceedings of the ION National Technical Meeting 1992, San Diego, Calif., USA, 1992], wide-spread use is also made, for example, of the, so-called “strobe correlator” [L. Garin, F. van Diggelen, J. Rousseau: “Strobe and Edge Correlator Multipath Mitigation for Code” in Proceedings of the ION GPS 1996, Kansas City, Mo., USA, 1996], the so-called “gated correlator” [G. MacGraw, M. Brasch: “GNSS Multipath Mitigation using Gated and High Resolution Correlator Concepts” in Proceedings of the ION National Technical Meeting 1999, San Diego, Calif., USA, 1999] and the so-called “pulse-aperture correlator” [J. Jones, P. Fenton, B. Smith: “Theory and Performance of the Pulse Aperture Correlator” in NovAtel Technical Report, NovAtel Inc., Calgary, Alberta, Canada, 2004]. When receiving new forms of signals, these known methods require a particular “tuning” to reduce the impact of multipath errors as much as possible.
[0007] Another approach to the reduction of multipath errors is to include the additional paths in the formulation of the estimation problem and to solve the same by optimum methods of simplifications of such methods. Techniques for the estimation of multipath errors treat multipath errors, especially propagation time delays, amplitudes and phases of the paths, as something to be estimated from channel observations, so that their effects can be removed trivially at a later processing stage.
[0008] The estimation techniques may be differentiated into static and dynamic solutions, depending on the underlying assumption regarding the channel dynamics. Exemplary for a static multipath estimation are such estimations that belong to the family of maximum likelihood (ML) estimators which often use various effective maximization strategies through the likelihood function. Examples thereof are known from:
[0009] D. van Nee, J. Siereveld, P. Fenton, and B. Townsend: “The Multipath Estimating Delay Lock Loop: Approaching Theoretical Accuracy Limits” in Proceedings of the IEEE Position, Location and Navigation Symposium 1994, Las Vegas, Nev., USA, 1994;
[0010] L. Weill: “Achieving Theoretical Accuracy Limits for Pseudo-ranging in the Presence of Multipath” in Proceedings of the ION GPS 1995, Palm Springs, Calif., USA, 1995;
[0011] J. Selva Vera: “Complexity Reduction in the Parametric Estmation of Superimposed Signal Replicas” in Signal Processing, Elsevier Science, Vol. 84, Nr. 12, Seiten 2325-2343, 2004; and
[0012] P. Fenton, J. Jones: “The Theory and Performance of Novatel Inc's Vision Correlator” in Proceedings of the ION GNSS 2005, Long Beach, Calif., USA, September 2005.
[0013] The drawback of ML estimator techniques is that the parameters are presumed to be constant during the observation period. Independent estimated values are obtained for successive observation intervals whose duration has to be adapted to the dynamics of the channels. For static channels, for which no previous information is available, the ML solution is an optimum approach and works significantly better than other techniques, especially for echoes with short propagation times.
[0014] An estimator for multipath situations that is based on sequential importance sampling (SIS) methods (particle filtering) and is considered in an article by P. Closas, C. Fernandez-Prades, J. Fernandez-Rubio, A. Ramirez-Gonzalez: “Multipath Mitigation using Particle Filtering” in Proceedings of the ION GNSS 2006, Fort Worth, Tex., USA, September 2006, is advantageous in that it allows the additional use of a-priori knowledge about the channel properties. Further, the instantaneous solution and its covariance matrix are used to estimate the subsequent point in time, whereby the time-related correlation of the estimation parameters is taken into account.
[0015] While all these known estimation methods are based on the same concept, they differ in the details of the manner in which they strive to realize the solution as effectively as possible. In effect, an immediate implementation will fail due to the unrealistically high complexity. With static channels, the ML estimator is optimal and obtains clearly better results than other methods, especially when the additional paths only show slight relative delays.
[0016] One possible way to combine the knowledge about the temporal correlation of the estimation parameters with the methods for an efficient implementation of an ML estimator, proposed in the above mentioned article by J. Selva Vera, is presented in an article by B. Krach, M. Lentmaier: “Efficient Soft-Output GNSS Signal Parameter Estimation using Signal Compression Techniques” in Proceedings of the 3rd ESA Workshop on Satellite Navigation User Equipment Technologies, Navitec 2006, Noordwijk, The Netherlands, December 2006.
[0017] The knowledge about the parameter development may be provided, for example, by the DLL/PLL loop of a conventional receiver. The method allows to calculate the a-posteriori distribution of the estimation parameters whose maximum can be determined, for example, with the methods stated in the above mentioned article by J. Selva Vera.
[0018] All presently existing methods are suboptimal and/or not adapted to the dynamic properties of the channels. In environments that are critical with respect to multipath propagation, such as in urban canyons in cities, the navigation receivers currently known do not work reliably.
[0019] When implementing a maximum likelihood (ML) estimation method, the number of paths is presumed to be known. In practice, this number has to be estimated or assumed, however, whereby the performance of these methods can be much impaired by erroneous assumptions or erroneous estimations of this parameter.
SUMMARY OF THE INVENTION
[0020] It is an object of the present invention to provide an advantageous solution with reduced complexity, with which multipath errors can be eliminated in an optimal manner in GNSS navigation receivers not only in static channel situations, but also in dynamic channel situations, whereby the reliability of such receivers is significantly increased and, above all, the determination of geographic positions is effected much more precisely.
[0021] According to the invention, which refers to a method of the type mentioned initially, this object is solved by using previous knowledge about the statistical dependencies between two successive sets of the time-varying channel parameters, introducing therein a movement model approximated to the actual channel environment, which model corresponds to a Markov process and forms the state transition model, wherein the knowledge that reflection signals typically have a life cycle starting from their first appearance and then experience a gradual change in their delay, amplitude and phase over time until they disappear, is used for an a-posteriori prediction, and, on the basis of this movement model, by sequentially estimating the channel parameters using the recursive Bayesian filtering, wherein the number of paths is implicitly estimated as well, the result of this estimation not only being a fixed estimated value, but a-posteriori probability density functions of the estimated channel parameters.
[0022] A description as a sequential Bayesian estimation problem allows to formulate an optimum solution approach for dynamic multipath channels. For the important practical case of dynamic channel situations, the present invention provides a solution to the problem of how to improve the estimation of propagation time when information about the development of the channel parameters over time is available. The solution proposed by the invention is based on Bayesian filtering, the optimum and well known framework for mastering such problems of dynamic state estimation.
[0023] Sequential Monte Carlo (SMC) methods are used appropriately in the practical implementation for calculating the a-posteriori probability density functions (PDFS) of the signal parameters.
[0024] An efficient and advantageous implementation of the sequential Monte Carlo method for calculating the a-posteriori probability density functions is possible with the use of “sequential importance sampling” (SIS) methods (“particle filter”), especially with the use of “sampling importance resampling particle filtering” SIR-PF.
[0025] Possible applications for the method operating according to the present invention, primarily exist in modern satellite navigation receivers, especially such receivers that are to allow navigation in difficult environments with strong, time-varying multipath propagation.
[0026] Furthermore, providing reliability information in the form of a-posteriori probabilities is of interest in certain so-called safety of life (SOL) applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The following is a detailed description of the invention with reference to the accompanying drawings. In the Figures:
[0028] FIG. 1 is a block diagram of the hidden Markov estimation process for three times, the channel measurements being represented by the sequence z i , i=1, . . . , k, and the channel parameters are x i , i=1, . . . ,k,
[0029] FIG. 2 is another block diagram of the recursive Bayesian estimation filter,
[0030] FIG. 3 an illustration of the Markov process selected in the following description for modelling a channel with N m paths, the dotted arrows illustrated only in a small partial set of the transitions indicating the secondary condition Δτ i,k ≧0,
[0031] FIG. 4 is a block diagram of an embodiment of an integration of the method of the invention into a conventional GNSS navigation receiver,
[0032] FIG. 5 is a diagram illustrating the simulation result for a multipath situation considered, the pseudo ranges (=propagation time multiplied by speed of light) [m] being represented as a function of time [s] in the direct path (line of sight) as a continuous line and temporarily existing echoes (multipaths) being shown as short lines, and
[0033] FIG. 6 illustrates, in a diagram of the distance measurement error [m] as a function of time [s] obtained by simulation, the performance of the sequential estimation process with particle filtering (lower line) according to the present invention compared with the result of a estimation using a conventional DLL with a “narrow correlator” (upper line).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0034] First, the underlying signal model will be explained.
[0035] Let it be assumed that the complex-valued, baseband-equivalent received signal equals
[0000]
z
(
t
)
=
∑
i
=
1
N
m
e
i
(
t
)
·
a
i
(
t
)
·
c
(
t
)
*
g
(
t
-
τ
i
(
t
)
+
n
(
t
)
)
(
1
)
[0036] where c(t) is a delta-train code sequence modulated to a pulse g(t). N m is the total number of paths allowed that reach the receiver (so as to restrict the modeling complexity), e i (t) is a binary function controlling the activity of the i-th path and a i (t) as well as τ i (t) are their individual complex amplitudes or time delays, respectively. Additional white Gaussian noise n(t) interferes with the signal.
[0037] If blocks of L samplings at the times (m+kL) T s , m=0, . . . ,L−1 are grouped as vectors z k , k=0, . . . , wherein the parameter functions e i (t), a i (t) and τ i (t) are assumed to be constant within the corresponding period and equal to e i,k (t), a i,k (t) and τ i,k (t), this can be rewritten as
[0000]
z
k
=
CG
(
τ
k
)
E
k
a
k
s
k
+
n
k
.
(
2
)
[0038] In the compact form of the right side of equation (2), the samplings of the delayed pulses g(τ i,k ) are stacked as columns of the matrix G(τ k )=[g (τ i,k ), . . . ,g(τ Nn,k )], where C is a matrix representing the convolution with the code and the propagation times and amplitudes are comprised in the vectors τ k =[τ 1,k , . . . , τ N m ,k ] and a k =[a 1,k , . . . ,a N m ,k ]. Moreover, E k =diag[e k ] is used in short notation, where the elements of the vector e k =e k =[e 1,k , . . . ,e N m ,k ] T ,e i,k ε0,1 determine whether the i-th path is active or not, by either e i,k =1, corresponding to an active path, or e i,k =0, corresponding to a path not active at the moment. The term s k refers to the signal hypothesis and is entirely determined by the channel parameters τ k , a k and e k . Using equation (2), the associated likelihood function can be written as:
[0000]
p
(
z
k
s
k
)
=
1
(
2
π
)
L
σ
2
L
·
exp
[
-
1
2
σ
2
(
z
k
-
s
k
)
H
(
z
k
-
s
k
)
]
.
(
3
)
[0039] The likelihood function is of central importance for the algorithms discussed herein; its purpose is the quantification of the conditional probability of the received signal determined by the unknown signal, specifically the channel parameters.
[0040] A reduction of the complexity can be obtained by data compression, interpolation and elimination of amplitudes.
[0041] In the PH.D. dissertation “Efficient Multipath Mitigation in Navigation Systems” y J. Selva Vera, Universidad Politécnica de Catalunya, February 2004, a general concept for an efficient representation of the likelihood of equation (3) was presented that is applicable to may existing ML multipath error reduction methods. The basic idea of this concept is to formulate the equation (3) by a vector z c,k that results from an orthogonal projection of the observed signal z k to a smaller vector space, so that z c,k is a sufficient statistic value according to the Neymann-Fisher factorization and is thus suitable for estimating s k .
[0042] In other words: the reduced signal includes the same information as the original signal itself. In practice, this concept becomes relevant, since the projection can be achieved by processing the received signal of equation (2) by means of a correlator bank and a subsequent decorrelation of the correlator output signals. A variant of this very general concept has also been referred to as a signal compression theorem for a set of special projections, which, due to the structure of the correlators used, do not require the decorrelation step.
[0043] Different from the correlation technique used in the above mentioned article by D. van Nee, J. Siereveld, P. Fenton, B. Townsend, the technique proposed in the article by P. Fenton, J. Jones, also mentioned before, for example already projects to an orthogonal and thus uncorrelated sub-space, similar to the code-adjusted correlator technique proposed in the above mentioned dissertation document. For reasons of complexity, all practically relevant embodiments of ML estimators operate in a projected space, namely after correlation. The corresponding mathematical background will be discussed farther below, including the interpolation of the likelihood and the elimination of complex amplitudes as further methods for a reduction of complexity.
[0044] First, data compression for the reduction of complexity will be discussed. As explained above, the large vector, which includes the samplings z k of the received signal, is linearly transformed to a vector z c,k of much smaller size. Following this solution, the likelihood of equation (2) may be written in another form as
[0000]
p
(
z
k
s
k
)
=
1
(
2
π
)
L
σ
2
L
exp
[
-
z
k
H
z
k
2
σ
2
]
·
exp
[
{
z
k
H
Q
c
Q
c
H
s
k
}
σ
2
-
s
k
H
Q
c
Q
c
H
s
k
2
σ
2
]
=
1
(
2
π
)
L
σ
2
L
exp
[
-
z
k
H
z
k
2
σ
2
]
·
exp
[
{
z
c
,
k
H
s
c
,
k
}
σ
2
-
s
c
,
k
H
s
c
,
k
2
σ
2
]
(
4
)
[0045] with the compressed reception vector z c,k and the compressed signal hypothesis s c,k :
[0000] z c,k =Q c M z k , s c,k =Q c H s k (5)
[0046] and the orthonormal compression matrix Q c that has to fulfill
[0000] Q c Q c H ≈I, Q c H Q c ≈I (6)
[0047] in order to minimize the compression loss. According to the above mentioned dissertation document, the compression may be double, so that
[0000] Q c =Q cc Q pc (7)
[0048] can be factorized to a canonic component decomposition Q cc and a principal component decomposition Q pc . In the above mentioned dissertation document, two possible choices are proposed for Q cc , namely
[0000]
Q
cc
=
{
CG
(
τ
b
)
R
cc
-
1
signal
-
adjusted
C
(
τ
b
)
R
cc
-
1
code
-
adjusted
(
8
)
[0049] where the elements of the vector τ b define the positions of the individual correlations. For a decorrelation of the correlator output signals, as mentioned above, the whitening matrix R cc may be obtained from a QR decomposition of CG (τ b ) or C(τ b ). Apart from operational conditions, both correlation methods indicated by equation (8) are equivalent from a conceptual point of view. As far as details regarding the compression by Q pc , reference is made to the above mentioned dissertation document.
[0050] Hereinafter, the interpolation performed in connection with the reduction of the complexity will be discussed. In order to calculate equation (4) irrespective of the sampling grid, interpolation methods may be employed to an advantage. When using the discrete Fourier transformation (DFT), where Ψ is the DFT matrix and Ψ −1 is its inverted counterpart (IDFT),
[0000]
s
c
,
k
=
Q
c
H
C
Ψ
-
1
diag
[
Ψ
g
(
0
)
]
M
s
c
=
const
.
Ω
(
τ
k
)
E
k
a
k
(
9
)
[0051] will be obtained, where Ω(τ k ) being a matrix of stacked vectors of a Vandermonde structure.
[0052] Finally, in the context of the reduction of complexity, amplitude elimination shall also be discussed herein. In a further step, the number of parameters is reduced by optimizing the equation (4) for a given set of τ k and e k with respect to the complex amplitudes a k , which may be achieved through a solution of a closed form. By using
[0000] S c,k =M S c Ω(τ k ) E k (10)
[0053] and obtaining S c,k + removing the zero columns from S c,k , the corresponding amplitude values of the active paths are obtained:
[0000] â k + =( S c,k +H S c,k + ) −1 S c,k +H z c,k . (11)
[0054] Since a potential source of loss in performance has been introduced by the elimination of the amplitudes and their correlation in time is thus practically not considered, it is proposed to optimize equation (4) by using
[0000]
z
_
c
,
k
=
1
Q
·
∑
l
=
0
Q
-
1
z
c
,
k
-
1
(
12
)
[0055] with the adjustable observation coefficient Q. When equation (4) is evaluated,
[0000] s c,k =S c,k â k (13)
[0056] is used, where the elements of the vector â k that indicate an active path (a k,i : i→e k,i =1) are set to the corresponding elements of â k + . All other elements (a k,i : i→e k,i =0) may be set optionally, since their influence is masked by the zero elements of e k .
[0057] The maximum likelihood (ML) concept will be discussed hereinafter in the context of the underlying signal model.
[0058] The concept of ML multipath estimation has given rise to substantial research interest ever since the first solution has been proposed in the above mentioned article by D. van Nee, J. Siereveld, P. Fenton, B. Townsend. Despite different approaches in different publications, the goal is the same for all ML solutions, namely to find the signal parameters that maximize equation (3) for a given observation z k :
[0000]
s
^
k
=
arg
max
s
k
{
p
(
z
k
s
k
)
}
.
(
14
)
[0059] Therefore, the signal parameters are assumed to be constant over the observation period k. There are different maximizing strategies that characterize the different solutions principally. Although substantial advantages in the theoretical analysis are offered, the practical advantage of the actual ML concept is doubtable due to a number of serious drawbacks:
The ML estimator requires the channel to be static for the observation period, and it is not capable of making use of its correlation in time over the sequence k=1, . . . . Measured channel situations have shown a significant correlation in time. Although of great interest in practice, the estimation of the number of reception channels often is not addressed. The decisive problem in this respect is to estimate the current number of paths correctly, so as to avoid a redundant determination, since a redundantly determined estimator tends to use the additional degrees of freedom for an adjustment of noise by introducing wrong paths. Various complex heuristics based on a selection of models are used to estimate the number of paths, by they suffer from the problem that the decision thresholds have to be adjusted dynamically. Typically, only a single hypothesis is followed which, in practice, causes the propagation of an error event. The ML estimator only provides the most probable set of parameters for the given observation. No reliability information about the estimated values is included. As a consequence, ambiguities and multimodes of the likelihood are not preserved by the estimator.
[0063] In practice, the following has to be taken into account during an ML execution. ML estimators require the parameters estimated to remain constant during the observation period. Due to data modulation and phase changes, this period, often referred to as the coherent integration time, is limited in practice to a span 1 ms to 20 ms.
[0064] In order to obtain a sufficient noise performance with an ML estimator, it is necessary to expand its observation interval to about the equivalent adjustment time of a conventional tracing loop that usually is on the order of several hundred coherent integration periods. To eliminate these problems, the observations must become quasi coherent by supporting the ML estimator with a phase lock loop (PLL) and a data removal mechanism.
[0065] The following is an explanation of the sequential estimation used in the method of the present invention.
[0066] First, the optimum solution will be discussed.
[0067] In the preceding part of the description, the signal models of the underlying time-varying processes have been established. The problem of multipath error reduction now becomes a problem of a sequential estimation of a hidden Markov process: The unknown channel parameters are to be estimated on the basis of a building sequence of received noisy channel output signals z k .
[0068] The channel process for each coverage range of a satellite navigation system may be modeled as a Markov process of the first order, if future channel parameters—with the present state of the channel being known—only depend on the present state of the channel (and not on any past states). It is further assumed that the noise influencing the sequential channel output signals is independent of the past noise values. Thus, each channel observation only depends on the present channel state. As is known, Markov processes of higher order can be transformed into such processes of the first order.
[0069] By intuition, not only the channel observation is used, to estimate the hidden channel parameters (through the likelihood function), but previous knowledge about the statistical dependencies between subsequent sets of channel parameters are used as well. It is known from channel measurements that channel parameters are time-varying, but not independently from one point in time to the next; usually an echo signal has a “life cycle” from its first appearance, followed by a more or less gradual change in its delay and phase over time, until it disappears.
[0070] After the principal assumptions have been made, the concept of the sequential Bayesian estimation may now be applied. The entire history of observations (through the time index k) may be written as
[0000] z k {circumflex over (=)}{z i , i=1, . . . , k}. (15)
[0071] Similarly, the sequence of parameters of the hidden Markov process is described by:
[0000] x k {circumflex over (=)}{x i , i=1, . . . , k}. (16)
[0072] Thus, x i represents the characterization of the hidden channel state including the parameters that specify the signal hypothesis s i given in equation (2). It is the objective to determine the posterior probability density function (PDF) of every possible channel characterization, wherein all channel observations are given: p(x k |Z k ) (see FIG. 1 ).
[0073] Once the posterior probability density function (PDF) is evaluated, one may either determine the channel configuration that maximizes the function—the so-called maximum a-posteriori (MAP) estimated value—or one may choose an expectation—equivalent to the estimated value of the minimum mean square error (MMSE). In addition, the posterior distribution itself includes the entire incertitude about the current range and is thus the optimum measure to perform a sensor data fusion in an entire position detection system.
[0074] It can be shown that the sequential estimation algorithm is recursive, since it uses the posterior probability density function (PDF) calculated for the time k-1 for the calculation of the posterior probability density function (PDF) for the time k (see FIG. 2 ). For a given posterior probability density function (PDF) p(x k−1 |Z k−1 ) at the time k−1, the prior probability density function p(x k |Z k− 1) is calculated in the so-called prediction step by applying the Chapman-Komogorov equation:
[0000] p ( x k |Z k−1 )=∫ p ( x k |x k−1 ) p ( x k−1 |Z k−1 ) d x k−1 (17)
[0075] where p(x k |x k− 1) is the state transition probability density function (PDF) of the Markov process. In the update step, the new posterior probability density function (PDF) for the step k is obtained by application of the Bayesian theorem on p(x|z k ,Z k−1 ), the normalized product being obtained from the likelihood p(x k |z k ) and the prior probability density function (PDF):
[0000]
p
(
x
k
Z
k
)
=
p
(
x
k
z
k
,
Z
k
-
1
)
=
p
(
z
k
x
k
,
Z
k
-
1
)
p
(
x
k
Z
k
-
1
)
p
(
z
k
Z
k
-
1
)
=
p
(
z
k
x
k
)
p
(
x
k
Z
k
-
1
)
p
(
z
k
Z
k
-
1
)
(
18
)
[0076] The expression p(z k |x k )=p(z k |s c,k ) follows from equation (4) and represents the probability of the measured channel output signal (often referred to as the likelihood value), determined by a certain configuration of channel parameters at the same time-interval k. The denominator of equation (18) does not depend on x k and can thus be calculated by integrating the denominator of equation (18) over the entire range of x k (normalization).
[0077] Summarized this far, the entire prediction and update process may be performed recursively in order to sequentially calculate the posterior probability density function (PDF) of equation (18) on the basis of an initial value of p(x 0 |z 0 )=p(x 0 ).
[0078] The evaluation of the likelihood function p(z k |x k ) is the essential part of the update step. Likewise, maximizing this likelihood function (i.e. ML estimation) is equivalent to a maximization of p(x k |Z k ) only in the event that the prior probability density function p(x k |Z k−1 ) does not depend on Z k−1 and if all values of x k a-priori have the same probability. Since these conditions are not met, the evaluation of p(x k |Z k ) entails all the previous steps.
[0079] The following will discuss the sequential estimation with the use of particle filters.
[0080] The optimum estimation algorithms are based on the evaluation of the integral of equation (17), which usually is a very difficult task, if not certain additional limitations are provided that are imposed upon the model and the noise process. Therefore, very often, a sub-optimum realization of a Bayesian estimator has to be selected for implementation.
[0081] According to the invention, the filter of choice is a sequential Monte Carlo (SMC) filter, especially a sampling importance resampling particle filter (SIR-PF) which may be considered a special case of a sequential importance sampling particle filter (SIS-PF). In this algorithm, the posterior density t the step k is represented as a sum and is specified by a set of N p particles:
[0000]
p
(
x
k
Z
k
)
≈
∑
j
=
1
N
p
w
k
j
·
δ
(
x
k
-
x
k
j
)
,
(
19
)
[0082] where each particle with the index j has a state x k j and a weight W k j . The sum over all particle weights is one. With SIR-PF, the weights are calculated according to the principle of importance sampling, the so-called proposal density being chosen such that it is p(x k |x k-1 =x k-1 j ), and with a resampling at each time interval. For N p →∞ the posterior approximation comes close to the true possibility density (PDF). Variants of the SIR-PF perform resampling only when necessary.
[0083] Hereunder, a selection of a suitable channel process made according to the present invention will be discussed.
[0084] In order to make use of the advantages of a sequential estimation to benefit the present problem of multipath error reduction/estimation, one has to be able to describe the actual channel characteristics (channel parameters) as precisely as possible, so that the same are covered by p(x k |x k-1 ). In other words: the movement model generated has to be a Markov model and all transition probabilities must be known. With the solution proposed by the present invention, the channel may be advantageously be approximated, for example, as follows:
The channel is completely characterized by a direct path (index i=1) and up to N n −1 echo signal paths. At the time k, each path described by the index i has a complex amplitude a i,k and a relative delay Δτ i,k =τ i,k −τ i,k−1 , where the relative delays of the echo signals can only assume positive values. The various path delays follow the stochastic process:
[0000] τ 1,k =τ 1,k−1 +α 1,k−1 ·Δt+n τ , (20)
[0000] Δτ i,k =Δτ i,k−1 +α i,k−1 ·Δt+n τ , i> 1. (21) The parameters α i,k describe the speed at which the path delays change and follow their own process:
[0000]
α
i
,
k
=
(
1
-
1
K
)
α
i
,
k
-
1
+
n
α
.
(
22
)
The value and the phase of the individual paths, described by the complex amplitudes a i,k , are eliminated by maximizing the likelihood function for given values Δτ i,k =τ i,k −τ i,k−1 with respect to a i,k . This serves to reduce the parameter space, aiming at a reduction of the complexity.
Every path may either be “on” or “off”, specified by the parameter
[0000] e i,k ε{0≡“aus”,1≡“ein”}. The values e i,k follow a simple Markov process with two states and asymmetric transition probabilities:
[0000] p ( e i,k =0 |e i,k−1 =1)= p onoff , (23)
[0000] p ( e i,k =1 |e i,k−1 =0)= p offon , (24)
[0092] The stochastic movement model includes two Gaussian noise sources n τ and n α as well as the noise process for controlling the state transitions for the values e i,k . These sources provide for the stochasticity of the movement model. The parameter k determines how quickly the values Δτ i,k can change. Δt refers to the time span between the times k−1 and k.
[0093] It is presumed that all model parameters, i.e. K, Δt, noise variances and the “on/off” Markov model are independent of k (see FIG. 3 ). It is noted that the movement model directly represents the number of paths as a time-varying parameter equal to Σ i=1 N m e i,k . The hidden channel state parameter x k may thus be represented as:
[0000] └τ 1,k , Δτ 2,k , . . . , Δτ N m ,k , α 1,k , . . . , α N m ,k , . . . , e N m ,k ┘ T (25)
[0094] When applied to the particle filter algorithm, obtaining the proposal density is simple. Each particle stores the above channel parameters of the movement model and the new state will be found randomly from p(x k |x k−1 j ), which corresponds both to obtaining of values for n α and n τ and to the concurrence of the “on”/“off” Markov model and the subsequent updating of the channel parameters for the time k according to the equations (20) to (24).
[0095] Thus, the method of the present invention is characterized by an implementation of the estimator for multipath suppression as a recursive Bayesian filter. Even the method known from the above mentioned article by P. Closas, C. Fernandez-Prades, J. Fernandez-Rubio, A. Ramirez-Gonzalez: “Multipath Mitigation using Particle Filtering” in Proceedings of the ION GNSS 2006, Fort Worth, Tex., USA, September 2006, does not follow the principle illustrated in FIG. 4 . The reinitialization of the particles and the transfer of covariance matrices used there, differ from the methods provided in this application. Thus, no optimum sequential estimation is proposed, as detailed above.
[0096] The selection of the movement model—proposed by the present invention—with the speeds of change and the variable life cycle of the paths is a particular feature of the method of the present invention.
[0097] The number of paths is implicitly co-estimated in the method proposed by the present invention. At the time k, it results from the sum of the values e i,k .
[0098] As a result, the method of the present invention yields a-posteriori probability density functions (PDF) of the estimated parameters, i.e. not only a fixed estimated value. Ambiguities are also included in the solution. This may be advantageous in the further processing within other modules of the receiver, e.g. for soft location.
[0099] As far as the adjustment of the movement model is concerned, it is important to point out that a sequential estimator only works as well as its state transition model adapts to the real ambient situation. The state model has to store all relevant hidden states in a memory and also has to model their dependencies, where the condition of the Markov process is maintained. Moreover, any storing of measurement noise that influences the likelihood function p(z k |x k ) must explicitly be included as an additional state of the model x so that the measurement noise is i. i. d. (independent and identically distributed).
[0100] The channel state model is due to channel modelling work for multipath-prone environments, such as an urban satellite navigation channel, for example. In effect, the process of setting up a channel model in order to characterize the channel for signal level simulations and reception evaluations is close to establishing a Markov process of the first order for sequential estimation. For particle filtering, the model has to meet the condition that states can be determined with relatively low computational complexity.
[0101] Adapting the model structure and the model parameters to the real channel environment is a task for current and future undertakings. It may even be possible to consider hierarchical models, in which the selection of the current model itself follows a process. In this case, a sequential estimator will automatically select the correct weighting of these models according to their ability to fit the received signal in.
[0102] The embodiment outlined in FIG. 4 as a block diagram illustrates an example of how the sequential estimator could be integrated into a conventional navigation receiver. This capitalizes on the architecture described in the above mentioned article by B. Krach, M. Lentmaier: “Efficient Soft-Output GNSS Signal Parameter Estimation using Signal Compression Techniques” in Proceedings of the 3rd ESA Workshop on Satellite Navigation User Equipment Technologies, Navitec 2006, Noordwijk, The Netherlands, December 2006, wherein a conventional DLL/PLL loop supports a bank of correlators whose output signals are filtered in an appropriate manner.
[0103] These filtered output signals then serve as measured values from which the likelihood values are calculated in a recursive Bayesian filter. For an efficient calculation, the known proposed methods may be used. The optional prefiltering allows to increase the time interval Δt and to thus reduce the complexity of the Bayesian filter.
[0104] Principally, it is to be noted that the computational complexity of the Bayesian filter algorithm is critical for the integration of the inventive method into a receiver. From a theoretical point of view, it is desirable to operate the sequential Bayesian filter such that it is timed according to the coherent integration period of the receiver, and to work with a large number of particles.
[0105] From a practical point of view, however, it is desirable to reduce the sequential filter rate to the navigation rate and to minimize the number of particles. Existing ML solutions may be helpful in reaching a flexible trade-off between complexity and performance, since one may directly use strategies already developed for the expansion of the observation periods of ML estimators to reduce the rate of the algorithm for a sequential Bayesian filtering.
[0106] FIG. 5 is a diagram illustrating a simulation result for a multipath situation observed. The simulations were performed both for BPSK-modulated signals and for BOC(1,1)-modulated signals. The pseudo ranges [m], i.e. the propagation time x the speed of light, as a function of time [s] in the direct path (line of sight) are indicated by the continuous line, whereas temporary echoes (multipaths) are indicated by short lines.
[0107] The multipath channel situation with up to N m =3 paths used in all simulations and illustrated in FIG. 5 , has been generated according to the movement model of the present invention, the parameters K=25000, σ n a =10 −10 , σ n r =10 −8 and p onoff =p offon =0.0001 being selected such that they are similar to a typical urban satellite navigation channel environment. The relative amplitudes of the echo signals were chosen to be constant and equal to 0.5, whereas the relative phases change according to Δφ i,k =2πΔ i,k f c , where f c =1575.42 MHz is the frequency of the L 1 carrier.
[0108] FIG. 6 shows results of computer simulations by means of which the performance of the SIS-based sequential estimator is compared with that of a conventional DLL with a “narrow correlator” for a BPSK modulation. Specifically, in the diagram of FIG. 6 , the performance of the sequential estimation method (lower line) with particle filtering, operating according to the invention, is shown by the distance measurement error [m] as a function of time [s] compared with the result for a conventional DLL with a “narrow correlator” (upper line”. The comparison of the residual error in FIG. 6 shows that the method proposed by the invention allows for clear improvements. In the simulation, a reduction of the mean square error from 3.77 m to 0.7819 m was achieved for BPSK modulation.
[0109] Although the invention has been described and illustrated with reference to specific embodiments thereof, it is not intended that the invention be limited to those illustrative embodiments. Those skilled in that art will recognize that variations and modifications can be made without departing from the true scope of the invention as defined by the claims that follow. It is therefore intended to include within the invention all such variations and modifications as fall within the scope of the appended claims and equivalents thereof.
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For the reduction of the multipath error of received GNSS navigation signals, a sequential Bayesian estimation is used, with a movement model underlying this estimation, which model is particularly designed for dynamic channel situations. Sequential Monte Carlo methods are used to calculate the posterior probability density functions of the signal parameters. To facilitate an efficient integration in received signal tracking loops, the invention builds on complexity reduction concepts that have previously been used in maximum likelihood (ML) estimators.
Applicable with GNSS satellite navigation receivers, e.g. GPS and Galileo.
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FIELD OF THE INVENTION
[0001] The present invention relates to a medical instrument, in general, and to a hemostasis apparatus for preventing profuse bleeding, particularly during a surgical procedure.
BACKGROUND OF THE INVENTION
[0002] In performing many medical procedures, it is necessary to make incisions. It is just as necessary to properly close the incision. Physicians would have experienced profuse bleeding while performing cutaneous or subcutaneous surgery on a patient. The profuse bleeding will cause numerous complications that will raise the risk of the surgery.
[0003] In prior instances, a physician would utilize a tourniquet, hemostatic cotton or a hemostat to prevent profuse bleeding of a patient during a surgical procedure. But the efficiency of the hemostasis is not quite satisfying, owing to the physical restraints of the above-mentioned devices. For instance, the tourniquet is not suited for a surgery on a human chest. Therefore, a new hemostasis apparatus could serve to rectify this problem.
SUMMARY OF THE INVENTION
[0004] An object of the present invention is to provide a hemostasis apparatus for preventing bleeding during cutaneous or subcutaneous surgeries.
[0005] Another object of the present invention is to provide a hemostasis apparatus for helping surgeries go more smoothly and safely.
[0006] A further object of the present invention is to save time and effort during surgeries.
[0007] Yet another object of the invention is to provide an economical and practical means to more easily facilitate surgery.
[0008] Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, four embodiments of the present invention are disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.
[0010] FIG. 1 a is a plan view of an embodiment of the present invention;
[0011] FIG. 1 b is a plan view of another embodiment of the present invention;
[0012] FIG. 2 a is a plan view of another embodiment of the present invention;
[0013] FIG. 2 b is a plan view of another embodiment of the present invention;
[0014] FIG. 2 c is a schematic diagram illustrating how the embodiment described in FIG. 2 b is applied on an arm of a patient;
[0015] FIG. 2 d is a schematic diagram illustrating how another embodiment of the present invention is applied on an arm of a patient;
[0016] FIG. 3 a is a plan view of another embodiment of the present invention;
[0017] FIG. 3 b is a plan view of another embodiment of the present invention;
[0018] FIG. 4 a is a plan view of another embodiment of the present invention;
[0019] FIG. 4 b is a plan view of another embodiment of the present invention;
[0020] FIG. 4 c is a schematic diagram illustrating how the embodiment described in FIG. 4 b is applied on an arm of a patient;
[0021] FIG. 4 d is a schematic diagram illustrating how another embodiment of the present invention is applied on an arm of a patient; and
[0022] FIG. 5 is a schematic diagram illustrating how the embodiment described in FIG. 1 b is applied on a breast of a patient.
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIG. 1 a is a plan view of an embodiment of the present invention. Referring now to FIG. 1 a , the hemostasis apparatus 100 is used to control bleeding while performing a surgery on a surgical area of a patient. The hemostasis apparatus 100 includes a first portion 101 having a closed structure, a second portion 103 and 105 , and an adjusting device 107 . In this embodiment, the first portion 101 is embodied as a ring 101 , the second portion 103 and 105 are embodied as two arcs 103 and 105 , respectively, and the adjusting device 107 is embodied as four screws 107 . The hemostasis apparatus 100 of this embodiment is preferably applied to a round surgical area of a patient, for instance, a breast. Before performing a surgical operation (either cutaneous or subcutaneous) on a breast of a patient, first the physician disposes the ring 101 on the patient to surround the breast and then affixes the ring 101 to the patient in order to maintain the relative position between the ring 101 and the patient. Second, the physician adjusts the adjusting device (or the four screws) 107 to an appropriate position to make the two arcs 103 and 105 support and stress the breast to control bleeding during the surgery. The foregoing appropriate position is determined according to different surgeries and necessities of bleeding control.
[0024] Referring to FIG. 1 b , in this embodiment, the frame shape of the first portion 101 is not circular. For precisely fitting, different patients' body shapes, the shape of the first portion 101 could be customized. Referring to FIG. 5 , the hemostasis apparatus 100 is applied on a breast of a patient. The shape of the first portion 101 is designed according to the patient's breast and her body shape. Therefore, the hemostasis apparatus 100 can be perfectly disposed on the surgical area of the breast and provide trustable stability between the patient and the hemostasis apparatus itself during operation. By similar way, at the outset the physician disposes the first portion 101 on the patient to surround the breast, and then affixes the first portion 101 to the patient in order to maintain the relative position between the first portion 101 and the patient. Then the physician adjusts the adjusting device (or the four screws) 107 to a appropriate position to make the second portions 103 and 105 support and stress the breast to control bleeding from a cut 53 made during the surgery.
[0025] Referring now to FIG. 2 a , the hemostasis apparatus 200 is used to control bleeding while performing a surgery on a surgical area of a patient. The hemostasis apparatus 200 includes a first portion 201 having a closed structure, a second portion 203 and 205 , and an adjusting device 207 . In this embodiment, the first portion 201 is embodied as a rectangular frame 201 , the second portion 203 and 205 are embodied as two support devices 203 and 205 , respectively, and the adjusting device 207 is embodied as four screws 207 . The hemostasis apparatus 200 of this embodiment is preferably applied to a rectangular surgical area of a patient, for instance, an arm or a leg. Before performing a surgical operation (either cutaneous or subcutaneous) on an arm (or a leg) of a patient, the physician first disposes the rectangular frame 201 on the patient to surround the arm (or the leg), and then affixes the rectangular frame 201 to the patient in order to maintain the relative position between the rectangular frame 201 and the patient. Second, the physician adjusts the adjusting device (or the four screws) 207 to an appropriate position to make the two support devices 203 and 205 support and stress the arm (or the leg) to control bleeding during the surgery. The foregoing appropriate position is determined according to different surgeries and necessities of bleeding control.
[0026] Referring to FIG. 2 b , in this embodiment, the frame shape of the first portion 201 is hexagonal rather than rectangular. For precisely fitting different patients' body shapes (or limb shapes), the shape of the first portion 201 could be customized. Referring to FIG. 2 c , the hemostasis apparatus 200 is applied on an arm of a patient. The shape of the first portion 201 is designed according to the patient's arm shape. Therefore, the hemostasis apparatus 200 can be perfectly disposed on the surgical area of the arm and can provide trustable stability between the patient and the hemostasis apparatus itself during operation. By a similar method, at the outset, the physician disposes the first portion 201 on the patient to surround the surgical area of the arm, and then affixes the first portion 201 to the patient in order to maintain the relative position between the first portion 201 and the patient. It should be noticed that, the first portion 201 includes a frame-adjusting device 209 , which adjusts the frame shape of the first portion 201 to help build a stable connection relationship between the first portion 201 and the arm. After the first portion 201 is arranged properly, the physician then adjusts the adjusting device (or the four screws) 207 to a appropriate position to make the second portion 203 and 205 support and stress the arm to control bleeding from a cut 211 during the surgery.
[0027] FIG. 2 d shows another embodiment of the hemostasis apparatus of the present invention. The first portion 201 is a three-dimensional structure that allows an arm of a patient to pass through the first portion 201 . The frame-adjusting device 209 here can also help the hemostasis apparatus 200 fit precisely on the arm of the patient. Therefore, the hemostasis apparatus 200 can be perfectly disposed on the surgical area of the arm and provide trustable stability between the patient and the hemostasis apparatus itself during operation. By a similar method, at the outset, the physician disposes the first portion 201 on the patient to surround the surgical area of the arm, and then affixes the first portion 201 to the patient in order to maintain the relative position between the first portion 201 and the patient. After the first portion 201 is arranged properly, the physician then adjusts the adjusting device (or the four screws) 207 to a appropriate position to make the second portion 203 and 205 support and stress the arm to control bleeding from a cut 211 during the surgery.
[0028] Referring now to FIG. 3 a , the hemostasis apparatus 300 is used to control bleeding while performing a surgery on a surgical area of a patient. The hemostasis apparatus 300 includes a first portion 101 having a closed structure, a second portion 103 and 105 , an adjusting device 107 and a resilient component 301 . The resilient components 301 are connected with the adjusting device 107 to facilitate the second portion 103 and 105 to stress the patient. In this embodiment, the first portion 101 is embodied as a ring 101 , the second portion 103 and 105 are embodied as two arcs 103 and 105 , respectively, the adjusting device 107 is embodied as four screws 107 and the resilient component 301 is embodied as a spring 301 . The hemostasis apparatus 300 of this embodiment is preferably applied to a round surgical area of a patient, for instance, a breast. Before performing a surgical operation (either cutaneous or subcutaneous) on a breast of a patient, the physician first disposes the ring 101 on the patient to surround the breast, and then affixes the ring 101 to the patient in order to maintain the relative position between the ring 101 and the patient. Second, the Physician adjusts the adjusting device (or the four screws) 107 to a appropriate position to make the two arcs 103 and 105 support and stress the breast to control bleeding during the surgery. The foregoing appropriate position is determined according to different surgeries and necessities of bleeding control. The spring 301 (or the resilient component 301 ) provides a force to facilitate the two arcs 103 and 105 to control bleeding during the surgery. After the surgery, the spring 301 can also provide a recovery force to facilitate the two arcs 103 and 105 reverting back to their original positions.
[0029] Referring now to FIG. 3 b , the hemostasis apparatus 300 is used to control bleeding while performing a surgery on a surgical area of a patient. The hemostasis apparatus 300 includes a first portion 101 having a closed structure, a second portion 103 and 105 , an adjusting device 107 and a resilient component 301 . The resilient components 301 are connected with the adjusting device 107 to facilitate the second portion 103 and 105 to stress the patient. In this embodiment, the first portion 101 is embodied as a ring 101 , the second portion 103 and 105 are embodied as two arcs 103 and 105 , respectively, the adjusting device 107 is embodied as four screws 107 and the resilient component 301 is embodied as a spring 301 . The hemostasis apparatus 300 of this embodiment is preferably applied to a round surgical area of a patient, for instance, a breast. Before performing a surgical operation (either cutaneous or subcutaneous) on a breast of a patient, the physician first disposes the ring 101 on the patient to surround the breast, and then affixes the ring 101 to the patient in order to maintain the relative position between the ring 101 and the patient. Second, the Physician adjusts the adjusting device (or the four screws) 107 to a appropriate position to make the two arcs 103 and 105 support and stress the breast to control bleeding during the surgery. The foregoing appropriate position is determined according to different surgeries and necessities of bleeding control. The spring 301 (or the resilient component 301 ) provides a force to facilitate the two arcs 103 and 105 to control bleeding during the surgery. After the surgery, the spring 301 can also provide a recovery force to facilitate the two arcs 103 and 105 reverting back to their original positions.
[0030] Referring now to FIG. 4 a , the hemostasis apparatus 400 is used to control bleeding while performing a surgery on a surgical area of a patient. The hemostasis apparatus 400 includes a first portion 201 having a closed structure, a second portion 203 and 205 , an adjusting device 207 , and a resilient component 401 . In this embodiment, the first portion 201 is embodied as a rectangular frame 201 , the second portion 203 and 205 are embodied as two support devices 203 and 205 , respectively, the adjusting device 207 is embodied as four screws 207 , and the resilient component 401 is embodied as a spring 401 . The hemostasis apparatus 400 of this embodiment is preferably applied to a rectangular surgical area of a patient, for instance, an arm or a leg. Before performing a surgical operation (either cutaneous or subcutaneous) on an arm (or a leg) of a patient, the physician first disposes the rectangular frame 201 on the patient to surround the arm (or the leg), and then affixes the rectangular frame 201 to the patient in order to maintain the relative position between the rectangular frame 201 and the patient. Second, the physician adjusts the adjusting device (or the four screws) 207 to a appropriate position to make the two support devices 203 and 205 support and stress the arm (or the leg) to control bleeding during the surgery. The foregoing appropriate position is determined according to different surgeries and necessities of bleeding control. The spring 401 (or the resilient component 401 ) provides a force to facilitate the two arcs 203 and 205 to control bleeding during the surgery. After the surgery, the spring 401 can also provide a recovery force to facilitate the support device 203 and 205 reverting back to their original positions.
[0031] FIG. 4 b illustrates another embodiment of the present invention. Comparing to the embodiment described in FIG. 2 b , the hemostasis apparatus 400 further includes several resilient components 401 to facilitate the second portions 203 and 205 to stress the patient to control bleeding during operation.
[0032] FIG. 4 c illustrates another embodiment of the present invention. Comparing to the embodiment described in FIG. 2 c , the hemostasis apparatus 400 further includes several resilient components 401 to facilitate the second portions 203 and 205 to stress the patient to control bleeding during operation.
[0033] FIG. 4 d illustrates another embodiment of the present invention. Comparing to the embodiment described in FIG. 2 d , the hemostasis apparatus 400 further includes several resilient components 401 to facilitate the second portions 203 and 205 to stress the patient to control bleeding during operation.
[0034] In other embodiments, the shape or structures of the first portion 101 (or 201 ) and the second portion 103 and 105 (or, 203 and 205 ) are variable, depending on the human body part that they are applied to. The first portion 101 (or 201 ) and the second portion 103 and 105 (or, 203 and 205 ) are made from materials compatible with human bodies, for example, stainless steel or rubber.
[0035] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the discovered embodiments. The invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
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A hemostasis device for controlling bleeding during a surgery is provided. The hemostasis device includes a first portion, which has a close structure, an adjusting device connected with the first portion, and a second portion connected with the adjusting device. The first portion is affixed to the patient to surround the surgical area, and a user adjusts the adjusting device to move the second portion to stress the patient to control bleeding during the surgery.
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BACKGROUND OF THE INVENTION
This invention relates to a fiber processing machine having rotary components, particularly a flats card or a roller card and further having a shroud which covers the rotary components at least on the top and on the side, including the bearings of the rotary components. The machine further has a suction device including at least one suction head for removing waste, such as dust and fiber fragments or other impurities by an air flow.
In fiber processing machines such as roller cards, it is conventional to surround the rotary components with a shroud from which the dusty air is removed by suction. The air quantities necessary for equalization enter the shroud, for example, from the spinning chamber. Such an arrangement however, lacks controlled flow conditions and further, the aerodynamic conditions underneath the shroud are not constant.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved fiber processing machine of the above-outlined type from which the above-discussed disadvantages are eliminated and which in particular, ensures an aerodynamic equilibrium underneath the shroud.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, between the shroud and the rotary components there is provided at least one blower head which introduces pressurized air into the space surrounded by the shroud.
The fiber processing machine according to the invention is fully covered by the shroud. Thus, the shroud extends also over the carding elements which, for example, in case of a flats card, may be the traveling flats and/or the fixed flats and which, in case of a roller card, may be the worker or the turner. Between the shroud and the rotary components there is provided at least one, but preferably a plurality of blower heads. Further, underneath the shroud there is situated at least one, but preferably a plurality of suction heads, so that a vacuum is generated which prevents dust from entering the spinning chamber. The outlet of the blower head is oriented in the direction of the suction head. In this manner there is provided an aerodynamic connection between the blower heads and the suction heads, that is, it is ensured that a tangential (Coanda effect) and diffused air flow passes through the inner space of the shroud in all zones. The air quantities introduced and induced by the blower heads correspond to the air quantities removed by means of the suction heads so that an aerodynamic equilibrium is maintained. Thus, as a result, there will be a well-determined inflow of pressurized air into the shroud. The quantity (flow rate) of the pressurized air is equal to or less than the quantity (flow rate) of the suction air. In the latter case, fresh air is drawn additionally from the spinning chamber into the blower chamber. In no event does, however, dust-laden air flow from the inner space of the shroud into the spinning chamber.
The fiber fragments, dust and microdust which are released during the carding of the fiber material are very effectively removed by suction. Thus, dust and waste are removed by suction from all areas of occurence such as tuft feed shaft, flats inlet, flat strips, corner zones between the carding cylinder and the doffer, web zone and waste accumulating chamber underneath the card. Such a suction arrangement satisfies the increasing requirements for a dust-free condition of the carding chamber, based on environmental considerations. The suction arrangement also reduces the generation of dust in machines arranged downstream of the card. Above all, the running conditions of the card and the downstream-arranged machines and thus their degree of efficiency and economic operation as well as the quality of the yarn are improved. This beneficial effect can be particularly felt in rotary spinning.
The invention may find application also in arrangements where the blower heads, although located in the lower carding chamber, cause their pressurized air current to be effective at least in part in the upper carding chamber. The upper carding chamber extends above the approximate horizontal center line of the feed roll, the lickerin, the carding cylinder, the doffer, the stripping roll, the squeezing rolls, the trumpet and the calender rolls, while the lower carding chamber extends underneath the approximate center line of these elements. It is further feasible to utilize, as pressurized air, the exhaust air from the air outlet openings of the tuft feed shaft arranged upstream of the card, by directing such pressurized air towards the card.
Preferably, in the upper carding chamber adjacent the shroud there is arranged at least one blower head. Expediently, the blower head extends over the entire width of the shroud so that over the entire shroud width uniform air flow, particularly pressurized air flow may be effected. This arrangement also ensures that a significant air quantity is introduced.
According to a further advantageous feature of the invention, the blower head is arranged at the lower edge of the shroud. If, in a preferred manner, a blower head is located at the rear and frontal lower edge of the shroud, the pressurized air currents may be received by means of a suction head situated between the two blower heads.
According to a further advantageous feature of the invention, the blower head is situated in the zone of the upstream material inlet, that is, above the feeding roll or the lickerin. It may be further of advantage to arrange the blower head in the zone above the flats (traveling flats and/or stationary flats). It is also advantageous to arrange the blower head in the zone above the fiber discharge zone, that is, above the doffer, the stripper roll, the squeezing rolls and the calender assembly. In case the dust-laden air is taken from the suction head of a filter arrangement and is, from the filter arrangement directed at least in part to the blower head, a partial or total circulating air system may be obtained.
According to a particularly advantageous feature of the invention, the blower head is designed as an injector nozzle which draws air from the zone externally of the shroud and blows the air into the space surrounded by the shroud.
Expediently, the outlet of the blower head is oriented towards one of the suction heads; in this manner directed and uniform air streams may be realized.
According to a further advantageous feature of the invention, at least one blower head is arranged inside the traveling flat bars; the air outlet openings of the blower head are oriented in the direction of the end rollers of the flats. Expediently, the blower head is arranged approximately in the middle between the end rollers of the flats and thus has an effect on end rollers at both ends of the flats. Preferably, the shroud is sealed from the lower carding chamber. In this manner there is effected a separation between the upper and the lower carding chambers as well as the drive chamber.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1 through 4 are schematic side elevational views of a fiber processing machine incorporating four preferred embodiments of the invention.
FIG. 5 is a schematic side elevational view of a component of a preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to FIG. 1, there is shown a carding machine which has a transfer table 1, a cover 2 arranged thereabove, a feed roll 3, a lickerin 4, a carding cylinder 5, a doffer 6, a web take-off roller 7, squeezing rolls 8 and 9, calender rolls 10 and 11 as well as a silver trumpet 12. Above the cylinder 5 there are arranged traveling flats 13 supported by an upstream end roller 13a and a downstream end roller 13b. Upstream of the carding machine there is arranged a tuft feeding assembly 14 including a feeding shaft 15 which has air outlet openings 16 and 17. A shroud 18 is arranged over the card and encloses the rotary components 3 through 11 from the top and laterally, including their bearings. Underneath the shroud 18 there are arranged suction devices constituted by suction heads 19a (above the corner zone between the doffer 6 and the web take-off roller 7), 19b (above the corner zone between the carding cylinder 5 and the doffer 6), 19c (underneath the end roller 13b), 19d (underneath the end roller 13a) and 19e (above the traveling flats 13). An apertured air guide baffle 20 is associated with the suction head 19e. Between the shroud 18 and the rotary components 3 through 11 there are arranged two blower heads 21a and 21b along the entire width of the shroud 18. The blower head 21a is situated approximately at the upstream lower edge of the shroud 18 in the zone of the fiber tuft inlet of the carding machine above the feed roll 3 and the lickerin 4, whereas the blower head 21b is situated approximately at the lower downstream edge of the shroud 18 in the zone of the fiber material outlet above the squeezing rolls 8 and 9, the sliver trumpet 12 and the calender rolls 10 and 11. The outlet of the blower heads 21a and 21b is oriented in the direction of the respective suction heads 19a through 19e. The dust-laden air from the suction heads 19a through 19e is admitted to a filter assembly comprising two filter boxes 22a, 22b and a filter 24. The blower heads are coupled to a pressurized air generator, such as a blower (not shown).
Inside the traveling flat bars (not shown) of the traveling flats 13 there is situated an additional blower head 23 which is formed, for example, of a perforated or slotted pipe and which extends over the width of the traveling flats 13. The lateral pressurized air outlets of the blower head 23 are oriented towards the end rollers 13a and 13b supporting the flats 13. The blower head 23 is situated approximately in the middle between the two end rollers of the flats.
The dust-laden air flows, for example, from the suction head 19e through the pipe 33 into the filter box 22; then flows through the filter 24 into the box 25 and is removed therefrom by the suction effect of a blower 26. The blower 26 drives one part of the air into a conduit 27 while another part of the air is admitted through the conduit 28, for example, into the blower head 21b. Thus, pressurized air exits from the blower head 21b; the air flows in the direction of the suction head 19e. As the air flows out of the blower head 21b, it entrains fresh air into the shroud 18 from the spinning chamber.
From the air outlet openings 16, 17 of the feed shaft 15 the used air flows through the space between the transfer table 1 and the cover 2 in the direction of the zone above the feed roll 3 and the lickerin 4 and is then removed by suction.
Turning now to FIG. 2, the embodiment shown therein comprises two blower heads 19f and 19g above the traveling flats 13. The outlets of the respective blower heads 19f and 19g are oriented towards two respective suction heads 21c and 21d. The suction heads 21c and 21d are situated above the intake zone and the discharge zone of the carding machine.
Turning now to the embodiment illustrated in FIG. 3, there is shown a blower head 19h situated at the lower downstream edge zone of the shroud 18. The outlet of the blower head 19h is oriented towards a suction head 21e which, in turn, is situated at the lower upstream edge zone of shroud 18.
In the embodiment according to FIG. 4, there are provided four blower heads 19i, 19k, 19l and 19m as well as three suction heads 21f, 21g and 21h.
Turning now to FIG. 5, there is illustrated a blower head 21 which is structured as an injector nozzle. The air is supplied from the zone externally of the shroud 18, that is, from the spinning chamber, and is delivered into the space underneath the shroud 18. The blower head 21 has a supply air inlet 30 from which the air is admitted through an obliquely oriented nipple 31 into a tube portion 32 having an inlet 32a and an outlet 32b. The air entering into the tube portion 32 from the nipple 31 entrains air through the inlet 32a. Both air streams leave the tubular portion 32 through the outlet 32b and travel towards one of the suction heads situated in the space surrounded by the shroud 18, as described above.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A fiber processing machine has rotary components, a shroud surrounding the components at least laterally and from above, a suction apparatus including at least one suction head situated in the space surrounded by the shroud for drawing away, by means of an air stream, fiber waste released during operation of the machine. There is provided at least one blower head which is located between the rotary components and the shroud for introducing pressurized air into the space surrounded by the shroud.
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BACKGROUND OF THE INVENTION
The invention relates to ice removal and, more particularly, to an ice chipping and removal system including a pair of vertical, rotatable drums.
In the petroleum exploration and production industry it is often necessary to move men and equipment through relatively hostile environmental regions. In recent years the emphasis on oil production from the far north has necessitated development of new techniques for moving materials through the Arctic regions.
In the Arctic, large regions are often covered by thick layers of ice and snow. As these layers move about, their edges override one another and form pressure ridges and hummocks in the ice. Hummocks are ice regions which are harder than the surrounding ice, have a very smooth outer surface and are formed when a pressure ridge heals itself through years of weathering. The arctic terrain is also shrouded by snow drifts which collect against the pressure ridges. In order to conduct petroleum production activities in the Arctic it is desirable to level off the pressure ridges and other protuberances which contribute to an extremely rough ice surface, for example, a smooth road surface must be formed through the rough ice in order to move vehicles and equipment across it.
One prior art system which has been used to smooth a path through the rough ice includes a large, toothed drum rotatable about a horizontal axis. The drum is supported on skids pushed by a large tractor and is rotated independantly from the bottom upwardly to undercut the ice. The major problem with such horizontal drum cutters is that when snow is encountered it is difficult to know what is beneath the snow, such as where the top surface of the ice is located. Since a rotating horizontal drum cuts ice equally well in both the vertical and horizontal directions, if the skids fall into a snow filled hole before the rotation of the drum can be stopped it may cut all the way down through the ice and take the tractor and operator with it through the hole into the underlying water. Needless to say, such systems have proven dangerous to both men and equipment.
Prior art snow removal systems, such as that disclosed in U.S. Pat. No. 1,615,461 to E. H. Lichtenberg, have sought to provide a pair of vertical rotating cutters for flaking the snow and moving it toward the intake of a blower which throws the snow away from the roadbed being cleared. While the Lichtenberg machine includes vertical rotating cutters, it would not be adaptable for cutting ice because of the lack of cutting teeth and augers for removing the ice chips. Further, the Lichtenberg cutters rotate toward one another to move snow into the blower while the present drums include overlapping teeth and rotate in the opposite direction, away from one another, to produce a forwardly directed force tending to move the machine through the ice.
Similarly, ice cutting equipment such as that shown in FIG. 1 of U.S. Pat. No. 3,696,624, entitled Bucket Wheel Ice Cutter, to John D. Bennett, the present inventor, employs counter-rotating bucket wheels mounted on the front of a ship. Such marine systems are designed primarily to cut through the entire thickness of a floating ice sheet and the cutting wheels do not include such features of the present drum cutters such as augers to remove ice chips from the path and a bottom drum surface which prevents cutting in the vertical direction except when desired. Further, in the prior art cutter the paths of the counter-rotating bucket wheels do not overlap in the region between the wheels to produce a forwardly directed force as in the system of the present invention.
It is therefore an object of the present invention to provide an improved system for cutting and removing ice and, more particularly, for forming an elongate, relatively smooth path through a rough snow and ice covered terrain. The system of the present invention provides a more efficient and relatively safe means for clearing a road through ice and snow.
SUMMARY OF THE INVENTION
The invention relates to a system for chipping ice and forming a path therethrough including a pair of vertically oriented drums each having teeth and an outwardly rounded bottom surface. Rotation of the drums while applying a forward force thereto chips the ice, augers the chips out of the path and produce a forwardly directed force tending to pull the drums through the ice.
In another aspect, the present invention includes a system for chipping and forming a pathway through ice which includes a pair of cylindrical drums mounted for rotation about parallel axes. A plurality of spikes protrude outwardly from each of the drums and the spikes on different drums intermesh with one another in the region between the drums when they are rotated. The drums are rotated in opposite directions away from one another at the front to chip ice and tend to pull the drums forwardly through the ice.
In still another more particular aspect the invention comprises a system for chipping and moving ice to form a pathway through rough icy terrain including a tractor for applying a forward force. An angular frame having a top and a back member is attached to the front of the tractor. A pair of cylindrical drums having smooth downwardly rounded bottom surfaces are mounted beneath the top member for rotation about parallel, generally vertical axes lying in front of the back member. An auger, including a plurality of flights, is spiraled about the outside periphery of each of the drums in opposite directions. A plurality of spikes protruded outwardly from each auger flight on each drum. Each spike on each flight lies in the same horizontal plane as another spike on a different flight of the same drum. All spikes on one drum lie in different horizontal planes from all spikes on the other drum to permit intermeshing of the spikes without interference. The drums are rotated in opposite directions, toward one another at the rear, to chip ice, auger the chips up and away from the system and tend to pull the drums forwardly through the ice to form a pathway.
BRIEF DESCRIPTION OF THE DRAWING
For a more complete understanding of the present invention and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a perspective view of the ice cutting system of the present invention mounted on the front of a tractor;
FIG. 2 is a side elevational view of the ice cutting system of the present invention;
FIG. 3 is a top plan view of the ice cutting system of the present invention;
FIG. 4 is a schematic side view of the ice cutting system of the present invention forming a roadway through rough ice;
FIG. 5 is a schematic top view of the ice cutting system of the present invention forming a roadway through rough ice; and
FIG. 6 is a cross-section view of one of the drums, having the auger flights removed, and taken about lines 6--6 of FIG. 3.
DETAILED DESCRIPTION
Referring to FIG. 1, there is shown a tractor 10 having the ice chipping and moving system of the present invention 11 mounted on the front. The tractor 10 may be of a conventional type having endless tracks 12, an enclosed Cab 12 for operation in arctic regions and a rear platform 14 which mounts an auxiliary motor driving a pair of hydraulic pumps 15, the function of which will be further explained below.
The ice chipper 11 includes a hollow angular frame 16 having a generally vertical back member 17 and a generally horizontal top member 18. The tractor 10 includes as pair of generally horizontal tooth bars 19 which are attached to lower portions of the back member 17 by means of pivotal connections 21. Top portions of the back member 17 are also attached to the tool bars 19 at pivotal connections 22 and 23 through tilting hydraulic cylinders 24. The tool bars 19 are attached to the front of the tractor 10 by lifting hydraulic cylinders 25. Operation of the hydraulic cylinders 24 tilts the frame 16 backward and forward about the connections 21 while operation of the hydraulic cylinders 25 raises and lowers the entire frame 16. The cylinders 24 and 25 are actuated through conventional control means on the tractor 10.
One of the motor driven hydraulic pumps 15 is connected to the ice chipper 11 by means of a first pair of lines 26 and 27 while the other pump is connected via a second pair of lines 28 and 29.
The ice chipper 11 includes a pair of cylindrical drums 30 and 31 mounted for rotation about parallel, generally vertical axes. Each of the drums 30 and 31 comprises an auger having a plurality of flights, 32 a-c and 33 a-c, respectively, spiraled about the outside surface. The auger on one of the drums has a right-hand thread while the auger on the other drum has a left-hand thread so that both will lift ice chips and snow when the drums are rotated in opposite directions toward one another. Each one of the auger flights 32 a-c and 33 a-c includes a plurality of downwardly extending spikes 34 located at the lower end thereof and a plurality of outwardly extending spikes 35 spaced along the length of the flights. On each one of the drums, the spikes 35 on each auger flight track one another, i.e., each spike on each flight is located in the same horizontal plane as another spike on each of the other two flights. The spikes 35 on different drums are located on different horizontal planes so that the spikes will intermesh one another without interference when the two drums are rotated. Each of the spikes 34 and 35 comprise a tooth holder and an elongate, pointed cutting tooth which can be replaced if damaged. As best shown in FIG. 2, the drums 30 and 31 each include a smooth, outwardly rounded lower end surface 36 for supporting the weight of the drums and for sliding smoothly across the surface of snow and ice during operation. The spikes 34 located at the lower ends of each of the auger flights 32 and 33 extend downwardly into the same plane as the lowest portion of the rounded end surfaces 36.
Referring next to FIG. 6, there is shown a partial cross-section and partial cut-away view of one of the drums 30. The top member 18, of the angular frame 16 (FIG. 1), is preferably hollow to reduce the weight of the structural assembly and to provide an internal void 40 for storing a reserve supply of hydraulic fluid. A circular opening 41 is formed in the top member 18 to receive a hydraulic motor 42 which rotates the cylinder 30. The motor 42 may be of a type similar to the Model B400S hydraulic motor manufactured by the Staffa Motor Company of Great Britain. The hydraulic motor 42 is coupled to one of the hydraulic pumps 15 by means of the hydraulic fluid lines 26 and 27 which extend through openings in a bolt-on snow cover 43.
The drum assembly shown in FIG. 6 comprises the cylindrical drum 30 which is fitted up into an overlapping annular ring member 44 and closed at the bottom by the rounded end surface 36. Located near the bottom of the drum 30 is a central hub 45 having an axial opening therethrough and which is attached at the top to a circular reinforcing plate 46 and at the bottom to the rounded end surface 36. A support frame 47 includes a central tube 48 and a plurality of vertically and outwardly extending support webs 49. An annular recess 51 in the upper, inner portion of the tube 48 receives a top bearing assembly 52 while another annular recess 53 in the lower, inner portion of the tube 48 receives a bottom bearing assembly 54. The bottom bearing assembly 54 is held in place within the annular recess 53 by a bolt-on retaining member 55. A driving pin 56 includes a flared head 57 at one end and, at the other end, an internally splined socket 58 and outer threads 59.
The support frame 48 is bolted to the undersurface of the top member 18 and the bottom bearing assembly is placed within the annular recess 53 and secured by the retaining member 55. The driving pin 56 is inserted up through the central hub 45, a lower sleeve member 61, the bottom bearing assembly 54, a central sleeve member 62, the top bearing assembly 52 and a pair of retaining nuts 63 and 64. When the retaining nuts 63 and 64 are tightened on the external threads of the driving pin 56, all of the parts surrounding the pin 56 are pulled into a rigid mechanism which will rotate as a single assembly on the bearings 52 and 54 and turn the drum 30.
After the drum is assembled the hydraulic motor 42, which includes a splined drive shaft 65, is placed down into the opening 41 so that the drive shaft 65 is received into the splined socket 58 to rotate the driving pin 56. The motor 42 is then bolted into position, the snow-cover 43 added and the two hydraulic fluid hoses 26 and 27 are connected to the external couplings of the motor 42 to complete the assembly.
Referring now to FIG. 3, there is shown a top view of the ice removal system 11 of the present invention. The drums 30 and 31 are positioned relative to one another so that the outermost paths of the auger flights 32 a-c and 33 a-c are preferably separated from one another by a distance slightly greater than the length of one of the spikes 35. The outermost circumferential paths of the tips of the spikes 35 overlap and intermesh one another by a maximum distance which is preferably about equal to the length of one spike 35. As set forth above spikes 35 are positioned on the augers 32 and 33 so that no two spikes 35 on different drums are located at the same height and, hence, there is no possibility of interference between spikes 35 on different drums if one of the drums is stopped while the other is still rotating. As can be seen from FIG. 3, the outermost circumferential paths of the tips of the spikes 35 on each drum 30 and 31 overlap one another in the region between the drums.
The engagement of the teeth 35 with ice in the regions extending from the front center of each drum around the outer periphery to a point located on a common diameter line of the two drums produces a force which tends to pull the drums in a forward direction through the ice. This forward force acts over a linear distance represented by the arrows 71. The engagement of the teeth 35 with ice in the regions extending from the front center of each drum around the inner periphery to the point of intersection of the outermost circumferential paths of the tips of the teeth, produces a force which tends to push the drums in a rearward direction. This rearward force acts over a linear distance represented by the arrow 72. Since the teeth act through a greater distance tending to pull the drums forward than the distance tending to push the drums rearward, there is produced a net forward thrust whereby the drums tend to pull themselves forward through the ice and reduce the pushing force required by the tractor 10.
The system of the present invention is designed to cut through ice primarily in the horizontal direction along a generally level grade line. As can be seen from FIG. 2, the spikes 34 located at the lower end of each auger flight extend down to approximately the same horizontal plane as the bottom of the rounded end surface 36. Accordingly, if the drums 30 and 31 are held with their axes of rotation vertical, they will cut in the horizontal direction on a level grade. If the drums 30 and 31 are tilted forwardly, they will cut horizontally on a gradually downwardly inclined grade. If the drums 30 and 31 are tilted rearwardly, they will cut horizontally on a gradually upwardly inclined grade. The drums may be readily tilted forwardly or rearwardly using the hydraulic cylinders 24. In no case however, will the drums cut ice in the vertical direction without motion in the horizontal direction and thus eliminate the possibility of accidentally losing control over the rotating drums and cutting through the ice to underlying water.
In actual operation, as illustrated in FIGS. 4 and 5, the auxiliary engine and hydraulic pumps 15 are actuated to provide hydraulic fluid flow and rotate both the drums 30 and 31 at a chosen rate e.g., 100 RPM. As the drums are rotating, the tractor 10 is operated to apply a forward force and the drum spikes 34 and 35 chip the ice into particles. As the ice is chipped into particles it is carried upwardly by the auger flights and dumped to the outside along with any snow which may be in the path. As can be seen from FIG. 4, the system of the invention forms a path through rough ice the width of the drums and on a relatively level grade. In the event it is desirable to cut vertically deeper or shallower into the ice, the drums are simply tilted forwardly or rearwardly to vary the slope of the grade.
Having discussed the invention in connection with certain specific embodiments thereof, it is to be understood that further modifications may now suggest themselves to those skilled in the art and it is intended to cover such modifications as fall within the scope of the appended claims.
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An ice chipper comprising a pair of cylindrical drums each mounted for counter-rotation about parallel, generally vertical axes. Each drum includes an outwardly rounded, disk shaped bottom surface and an auger flight spiraled helically about the outer cylindrical surface thereof. The auger flights each include a plurality of spaced, outwardly extending teeth to chip the ice abutting the front of the system. The chipper is mounted to the front of a tractor and each drum includes a hydraulic motor which is operated by a hydraulic pump also carried by the tractor. Rotation of the drums causes the auger teeth to chip the ice and tends to pull the drums forwardly while the auger flights carry the ice particles up and out away from the cleared area. Tilting the system forwardly and rearwardly upon the rounded drum bottom surfaces varies the depth of cutting in the vertical direction.
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BACKGROUND OF THE INVENTION
The present invention relates to ascertaining the miss distance of firing upon stationary or moving training targets, under utilization of the compression or shock waves of passing projectiles, whereby particularly the method as well as equipment for carrying out the method is the subject matter of the invention.
It is known generally to measure acoustically the distance by which a projectile aimed at a target either a resting i.e. a stationary target or a moving training target, has missed it. The target may have moved with subsonic speed. Projectile aimed at a target usually moves with supersonic speed and produces a conically spreading shockwave. This shockwave and its passage is detected at measuring points under utilization of microphones. The pressure and shock wave production point as far as the projectile path is concerned as well as the amplitude and/or the duration of the shockwave is used for measuring the miss distance. This method of measuring the distance is however not very reliable for moving targets particularly on account of the vector relation between the projectile speed, the target speed and the shockwave as it propagates. In fact, a correct result will be ascertained only in cases of peculiar coincidences among these vectors.
German printed patent application 31 22 644 discloses a method and equipment for acoustically measuring the miss distance as between a projectile and a flying target, and attempts have been made as per this reference to avoid the errors outlined above. Specifically, the method as disclosed there attempts to measure the strength of the shockwave pressure produced by the passing projectile which measurement is carried out by the target itself and the measuring result is transmitted to equipment on ground.
Based on predetermined parameters the distance between projectile path and target is ascertained at the instant of passage which in effect is the shortest distance between target and projectile. This obtains by ascertaining the period of duration of the pressure wave as it affects the target, and the angle between target trajectory and projectile trajectory. These values are then used to calculate the true distance between target and trajectory under utilization of a correcting factor. The accuracy of the measurement is dependent on the accuracy of predetermined parameters. Since a pressure wave is measured by means of microphone the so called "bang" effect influences the measurement and it is well known that problems arise when pressure by means of microphones.
European patent 0003095 suggests an expansion of the method mentioned above but now under utilization of five microphones whereby 4 microphones are arranged in the corners of a polyhydron or "tetra" This arrangement permits not only the quantitative measurement of space and distance information between projectile path and target but the directional information is also available in this way. However, this method is subject to the following problems.
The configuration of the pressure or compresssion shock wave produced by the passing projectile is dependent on numerous operating parameters such as the type and configuration of the projectile, its distance, target speed and angle of directing the projectile so that any kind of combination requires separate calibration; numerous parameters enter into the picture and the situation is quite difficult. The same is true with regard to the correction needed for and in the evaluation by means of processing equipment during real time operation. On the other hand it has to be considered that changes in the configuration of the pressure wave as it spreads is very difficult to ascertain by way of calculation so that an evaluation requires numerous very extensive and expensive calibrating procedures, for obtaining particular wave contours as reference under various different conditions of operation; also, there is a need for cyclically repeated calibration.
The ascertaining of the pressure wave configuration by means of a microphone is interfered with through a large number of interfering sources such as noise, temperature variations and particularly the case of relatively high target speeds, these factors become increasingly noticeable. Also, the conversion of information under consideration of the Doppler effect and certain properties of the microphone are difficult.
DESCRIPTION OF THE INVENTION
It is an object of the present invention to provide a new and improved method by means of which the miss distance as between a projectile and a training target can be ascertained with great accuracy whereby particularly the utilization of microphones is avoided so that as far as the pressure and shockwave is concerned, only the info on the passage of the pressure wave front is to be used.
In accordance with the preferred embodiment of the present invention, it is suggested to provide a plurality of transducers and arranging them at least approximately, on a straight line. This group of sensors will cut through the pressure wave emanating from the passing projectile in that the temporally variable pressure acts as trigger pulses for triggering transducers as the shockwave passes. This way an intersecting hyperbola of the Mach cone of the passing projectile, is ascertained. One needs at least three points. This, however is just a theoretical minimum requirement concerning the acquisition of data defining hyperbola. In reality and for reasons of accuracy one should use many more.
Therefore the present invention suggests a completely new approach of acquiring data on a passing projectile. One uses basically very simple pressure sensors which are arranged in a line arrangement i.e. they are strung along a linear carrier and form a straight line. This linear arrangement of a sensor group or transducer array just responds to the passage of a wavefront in that each sensor or transducer just produces an onset-of-pressure change pulse namely when being triggered by the passing shockwave front. Therefore, one obtains a plurality of basically independently produced and temporally differing pulses. The geometry involves consideration that this measurement is equivalent to the "cutting" through the Mach cone i.e. one does in effect ascertain a cone section which of course has different configurations depending on the plane of cutting and intersection. Usually that cone section will be a hyperbola.
Therefore the configuration of the shockwaves itself as it is produced by supersonic projectiles is no longer the subject to measurement. In other words, it is avoided to extract distance information from absorption patterns. This would require microphones as is known for ascertaining the configuration of the shockwave, particularly as produced by the front and rear edges of the projectile. As far as the invention is concerned all these known or supposedly known complex relations between shockwaves configuration and its modification such as reduction of amplitude with increasing distance, difference in that reduction as between the different kinds of shockwaves produced by head and tail of the projectile, all contain changes with increasing propagation time and distance from the point of origin; but they are all factors which are no longer of importance since one intentionally is not interested any longer in obtaining directly the distance, that is a desired distance value between some kind of sound sensor (microphone) and the closest point of projectile's trajectory on the basis of shockwave configurations. The approach taken by the invention involves multiple measurement of pressure onset by means of simple sensors and transducers is basically different, as the goal no longer the configuration of a shockwave in any particular point, the goal is to ascertain a cone section from which to reconstruct the Mach cone as it passes with the passing projectile.
The pressure sensors and transducers that can be used here for practicing the best mode of the invention can be extremely simple and are quite economical without requiring any particular thrills and exotic properties. All that is required is that they provide some form of recognizable signal when a pressure compression shock wave passes which is sufficiently discernible and separable from ambient noise. These signals, particularly a leading edge, is used as a trigger whereby of course the timing of triggering by the different transducers is the composite set of factors that relate to the geometry of the hyperbola.
One can use very simple piezomembranes as pressure sensors and transducers. Owing to the intentional economy involved in the choice of the individual pressure transducers and sensors one can and should use many of them. Ultimately the cost factor may be the same. In other words there is a tradeoff of using many cheap transducers rather than a few expensive microphones, but ultimately practicing the invention is more economical and more accurate and more reliable because the sensor assembly can be placed much closer to the target position without incurring losses.
Considering some aspects in greater details, as stated the line of sensors or transducers cuts through the Mach cone of a projectile resulting in a particular conic section. In the present case specifically the cut and intersection occurs in the direction of the cone that is in the direction of the axis of the cone, so that as a consequence and based on elementary geometry the cone section is a hyperbola indeed. In the special case of a full hit of a stationary target, the hyperbola degenerates into a pair of straight lines. In the case of a movable target and of a full hit there is an imaginary image. This image results also in all cases where the cutting angle is not equal to 90 degrees.
If a straight line of pressure transducers is intersected by a Mach cone of the projectile the individual transducers will be triggered one at the time by the shockwave front of the Mach cone, as that cone becomes wider and wider, and this sequential intersection is of course reflected in temporal staggering of trigger pulse production. The delay in triggering between the adjacent transducers, under consideration of the known distance between them, the configuration of the cone section can in fact be ascertained. They are in all cases hyperbolas or affine transformations thereof.
A hyperbola is characterized by a mathematically defined configuration which means that three points are sufficient to determine the coefficience of such a hyperbola. Of course, as stated above one should have many more simply to eliminate tolerances and inaccuracies in the measurement. Once the hyperbola is known the disposition of the Mach cone and the distance of the cone axis from the line of transducers can easily be calculated. However, there is an inherent ambiguity on account of the symmetry involved; the projectile may have passed to one side or the other side of the transducer line. By using another pressure transducer, off the line of transducers one can indeed resolve that ambiguity and determine the disposition of the projectile's path.
In case the training target is a moving one, and of the intersection angle between the line of transducer and the trajectory is unequal to 90 degrees, one needs a mathematical transformation of the affine transformation of the original hyperbola back to the original hyperbola, under consideration of scale and under further consideration of the speed of the training target. The relative speeds of target projection can be ascertained through triangulation of Mach numbers.
The inventive method has the following advantages over the known procedures. First of all one does use nor even expensive microphones so that all problems inherent in the use of such microphones are avoided. Rather one uses simple pressure transducers which are considerably less expensive and can be used therefore in large numbers, even in those areas which in those cases whereupon a hit then will be lost. Rather than ascertaining the configuration of a pressure wave produced by the passing projectile one determines in a much more accurate fashion the cone section of the Mach cone that propagates from the projectile. The cone section results from the fact that the line of sensors cuts through the Mach cone and one simply needs the initial rise in pressure as determined by the individual transducers as the instant of passage of the line through the cone. There is no special requirement concerning the transmission of the measuring signal from the transducers to the evaluating unit. Certain calibrations e.g. cyclic calibration and predetermination of certain parameters is not necessary.
DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the objects and features of the invention and further objects, features and advantages thereof will be better understood from the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a somewhat schematic view of a line of sensors or transducers in accordance with the preferred embodiment of the present invention for practicing the best mode thereof in determining a cone section of a Mach cone;
FIG. 2 is a transducer response vs time diagram for reconstructing the hyperbola that results for a cone section wherein the transducer line shown in FIG. 1 cuts through the Mach cone of a passing projectile.
FIGS. 3a and 3b are signal and pulse vs time diagrams concerning the production of an output of individual one of these sensors and transducers.
Proceeding now to the detailed description of the drawings, FIG. 1 illustrates a line of sensors, the sensors being individual pressure transducers 2. These passes transducers are strung on a carrier cable or the like that is suspended from a training target or the like such as moving aircraft AC. This line 1 of transducers 2 is passed by a projectile 6, which of course moves at supersonic speed, issuing and from the passage shockwave emanates to a Shockwaves issue from the projectiles so that a Mach cone 7 emanates therefrom. The line 8 in FIG. 1 is hyperbola which is the intersection of the cone 7 with the sensor line 1.
The cone 7 has a center axis 11. If we assume that the line 1 of transducers 2 is actually situated in the plane of the drawing then the cone, i.e. the cone's axis is off that plane and the line 8 is in effect the cone section produced by the MACH cone 7 as it intersects the plane of the drawing.
FIG. 2 illustrates how the hyperbola 8 is reconstructed from the instant of triggering of the individual sensors 2 and transducers of the line 1. The line of triggering is the result of comparing the times of triggering of various transducers 2 with each one. The transducers 2 each provide a pulse when passed through by the Mach cone, and this occurs, as per FIG. 3c by determining that a particular pressure threshold value 12 being e.g. 68 dB is exceeded. That level must be located sufficiently above the noise level which is normally provided. FIG. 3b shows the transducer output on account of a sensor signal 13 exceeding the threshold 12.
There is a trade-off between the lowest reasonably ascertainable Mach cone shockwave, and the highest noise level resulting from the fact that the target AC is in the vicinity of the transducers. (Noise of the aircraft engines etc.) The threshold 12 therefore must be selected to be above the normal noise level 13 and well below a typical projectile noise level such as the peak 14.
The pulse issued by a transducer together with some form of identification of the transducer i.e. its relative position in line 1 of transducers is transmitted to evaluating units e.g. on board of the aircraft or on ground. The timing of all pulses is then used in a computer to reconstruct the section hyperbola in accordance with FIG. 2. Owing to a large number of transducers used in the line 1 the hyperbola or its affine image 8 is well known. The branches approach asymptotic lines so that the relative position of the Mach cone 7 at the time of passage, including particularly the axis 10 of the hyperbola in relation to the axis 11 of the cone can be calculated. The desired distance value is now the distance between these two axes from each other.
Having done these calculations one can easily determine the angle between the line of transducers and the path of the projectile. In FIG. 1 it is moreover arbitrarily assumed that the transducer 5 within the line 1 of transducers 2 establishes the center of the target so that in addition to the distance between the two axes 10 and 11 from each other, the distance of the axis 10 from this transducer 5 is a factor for determining the projectile path distance from the center of the target as thus defined. In addition of course the geometry to be considered requires the consideration of the relative speed of the line 1 in relation to the mach cone and its axis 11. The motion of the target is of course colinear with the line 1 but as a specific point of reference one can consider the motion of the target to be the motion of the transducer 5. In the case of moving targets therefore before and behind and behind as taken in relation to the movement of the target 5 is to be considered to the left and right consideration as far as the axis 11 is concerned.
In addition a supplementary transducer 4 is provided outside of the horizontal and of the vertical plane in which line 1 lies to determine the disposition of the cone above or below the line of sensors and transducers, as well as to the left and to the right. Several out-of-line transducers can be used, particularly to increase certainty through redundancy.
The moving of a training target as per in FIG. 1 and as illustrated here, is established by a towing cable C extending from aircraft AC from which the line of sensors 1 is thus suspended. The towing action involves specifically moving the particular transducer 5 which is so to speak the target proper and the transducers 2 in front and behind are then the instruments by means of which the cone section of the miss is ascertained. In this case the intersection hyperbola 8 is an affine image or transformation of an original hyperbola. This affine image requires a retransformation into the original hyperbola, and only then is it possible to determine the miss distance. The determination of target speed and of projectile speed as function of the Mach number is the result of forming a so called Mach number triangle.
Another transducer 3 in front of the line is not a pressure transducer but is representative of measurement of supplemental parameters in the region through which the line of transducers passes. Transducer 3 measures the temperature. This is an important feature since the speed of sound varies with temperature and one can now provide an adequate correction in the speed determination and in the meaning of the Mach cone in terms of absolute speeds of each and both projectile and target. Another parameter of course is the elevation of the target above ground which is so to speak the vertical distance from the gun firing the projectile.
Moving training targets are usually dragged or drawn devices which are pulled by means of a drag cable C under utilization of the aircraft AC as illustrated. The line of sensors and transducers forms one long line as it traverses the plane across the training ground and will of course project at least from one end or one point of the transducer (5) defining the target proper.
The line of sensors is preferably integrated into the drag cable. Strictly speaking in the example shown in FIG. 1 the target is the point, namely the location of the transducer 5 and that is also a representation of the center of a target. In addition of course several transducers are situated in front and others are behind that transducer 5 and they too can be associated physically with the length of the target and are identified therewith. This is in addition to the function of the line of transducer as "hyperbola cutters".
If one wants to have a still more realistic 3D approach to target simulation several of these lines of transducers can be used and they together define a 3D configuration. They may be running parallel or through appropriate spacers could be arranged at an angle to each other. In lieu of such a multiple line arrangement one should consider a drag body like a sac or the like which carries two or more lines of sensors. If two or more lines of sensors are used then the supplemental transducer 4 is no longer necessary.
For mathematical reasons the term "line of transducers" requires at least three pressure transducers arranged on a line. This is the minimum for ascertaining a cone section. Of course the accuracy with three transducers will not be very high but in simple cases it is conceivable that the accuracy from using just three transducers may suffice. The number of transducers used in this cone cutting line and the spacing between them are not the only parameter that determine the accuracy from the passing projectile. Obviously, the more transducers are available on one hand, and the closer they are spaced on the other hand the more accurate will be the result. The transmission of the pulses monitored by each transducer is relatively simple. In the kind of example shown in the drawing there are simply wires that are integrated in the towing cable C and then the usual on-board facilities on the craft AC take over. The processing of the signals may be carried out immediately by an on-board computer equipment or there is a transmission to ground. There is the choice of transmitting processed or unprocessed data to ground or one may not even need transmission to ground but evaluate whatever result obtains by an onboard processor for use in subsequent study sessions.
It is advantageous to provide immediately on board analog-to-digital conversion of the transducer signals in order to obtain digital signals right in the beginning which of course includes also the ascertaining of times of relative trigger times of the various transducers. As stated, the processing facility may either on board or on ground or both and may include display indications as it may be desirable to have immediately the measuring result visually available; how far did they miss the target, conceivable the trajectory may be displayed in a 3D fashion including target positions and identifications in various forms. All this may ultimately result in statistical evaluations of the process, particularly if one projectile after another is fired at the target.
The invention is not limited to the embodiments described above but all changes and modifications thereof, not constituting departures from the spirit and scope of the invention, are intended to be included.
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The miss distance of a projectile aimed towards a target is determined by a line of pressure transducers other than microphones which through response to a sudden pressure change together establish a cone section through a passing Mach cone; and the time space analogies of that cone permits reconstruction of the projectile path being in effect the axis of that cone.
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RELATED APPLICATION
[0001] This application is a continuation under 37 C.F.R. 1.53(b) of U.S. application Ser. No. 09/450,648 filed Nov. 23, 1999, which application is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention deals broadly with the field of windows, and more particularly with those windows, such as double-hung windows, wherein a sash slides within a frame. The invention specifically relates to mechanisms for retaining a window sash within a frame at an intended location along an axis perpendicular to a plane defined by the window frame within which the sash slides, and more particularly to an actuator for such a sash retention mechanism.
BACKGROUND
[0003] The prior art includes many types of windows which are employed to bring light into a building. One popular type of window known in the prior art is a double-hung window, and the background of the present invention will be described in that context (although it should be noted that the present invention can certainly be used with any tiltably removable sliding sash window and is not limited to double-hung windows).
[0004] A double-hung window typically employs two movable sash assemblies, each carrying its own pane of glass, which are typically movable vertically within the frame. For most double-hung windows it is highly desirable that the sashes be inwardly tiltable and/or removable, so that the glass portions of the sash assemblies can be easily cleaned. Various types of sash retention mechanisms have been utilized to effect maintenance of a sash in the desired position yet allow it to be tilted inwardly or removed for cleaning. The present invention is directed to a sash retention mechanism actuator, so the remainder to this background discussion will focus on such mechanisms.
[0005] One type of sash retention mechanism utilizes a pair of independently-operable latch elements carried by the sash. The latch elements extend laterally out of the sash and into a groove or track formed by the frame. One latch element extends laterally from one side of the sash, and a second latch element extends laterally from the other side of the sash. When it is desired to remove a sash, the person removing the sash releases (i.e., retracts the latch element back into the sash) one latch with one hand and releases the other latch with the other hand. The sash is then tilted or slid out of its normal position and removed from the frame for cleaning. Such an “independent-latch” sash retention mechanism has a number of drawbacks, not the least of which is that the person removing the window sash needs full availability of both hands to effect release cf the latches.
[0006] To address problems associated with “independent-latch” sash retention mechanisms, attempts have been made to design a mechanism for concurrently releasing both latches (that is, for simultaneously effecting retraction of the latches). One such “concurrent-latch” sash retention mechanism is disclosed in commonly-assigned U.S. patent application Ser. No. 09/328,085. Latch elements (i.e., the elements that extend into the groove or track in the window frame) for “concurrent-latch” mechanisms can move in and cut relative to the sash along a straight line or they can pivot in some fashion (as disclosed in the aforementioned commonly-assigned patent application), but regardless of the specific type of latch element being used, an actuator of some sort is necessary to draw the latch element out of the corresponding groove or track in the window frame so that the sash can be removed or tilted as necessary. The present invention relates in particular to an improved actuator for a “concurrent-latch” sash retention mechanism.
[0007] While “concurrent-latch” sash retention mechanisms are theoretically superior to “independent-latch” mechanisms due to the one-hand versus two-hand operation advantage discussed above, the actuators in prior art “concurrent-latch” mechanisms have been problematical. For example, one design, shown somewhat pictorially in FIGS. 1 - 4 hereof, uses a plastic strap captured by a winder to actuate a pair of linear latch elements (not shown).
[0008] In the “plastic-strap/linear-latch” design discussed immediately above and partially shown pictorially in FIGS. 1 - 4 hereof, the tilt actuator includes a tilt lever (not shown) mounted at the top of the sash (assuming for the purposes of this discussion that the double-hung window is in its typical, vertical orientation with the sashes sliding up and down rather than side to side). The tilt lever is connected to the upper end of a cylindrical winder which rotates about a vertical axis. The lower end of the winder fits into a round aperture formed by a housing contained within the sash frame.
[0009] In addition to the winder aperture, the housing also forms a pair of laterally extending channels that extend from the winder aperture to the outer lateral edges of the housing. The lower end of the winder, the end that rotates within the winder aperture, is slotted in a manner that would appear to be a screwdriver slot as viewed from the bottom. This slot is a simple, vertical-walled slot extending diametrally through the lower end of the cylindrical winder.
[0010] A plastic strap, of the type used to bind or bundle various materials, having a generally rectangular cross section, is received within the “screwdriver slot” in the lower end of the winder. Note that FIGS. 2 - 4 show only the edge of the strap, not its width. When the tilt lever is in its un-activated position the winder slot is aligned with the channels in the housing, as shown in FIG. 2. As the tilt lever is rotated, as shown in FIG. 3, the winder is supposed to evenly and equally act on the strap to simultaneously draw the linear latch elements inwardly and out of their corresponding grooves or tracks in the window frame, to permit tilting/removal of the sash.
[0011] While the strap-type actuator mechanism shown in FIGS. 1 - 4 is an advance over typical “independent-latch” mechanisms that require two-hand operation, it has certain limitations. One of its limitations is that it employs a housing, and another has to do with its use of a strap.
[0012] As noted above, one shortcoming of prior art strap-type sash retention mechanism actuators is that they include a “housing,” defined herein as a component that receives the lower end of a winder and forms channels for laterally guiding the strap. An actuator housing such as that employed by prior art strap-type actuators is an unnecessary part (as compared to preferred embodiments of the present invention) that adds cost in and of itself, increases the assembly time and cost, and introduces an additional source of friction and binding for the strap, thus potentially making it more difficult to actuate the tilt mechanism.
[0013] While the housing of the prior art strap-type actuator design may cause certain problems, FIG. 4 shows what would happen if the housing in this particular design were omitted. Initially, when the tilt lever is in its normal, unactivated position, the slot in the lower end of the winder is aligned with the linear latch elements. See FIG. 2. If the housing were absent, movement of the tilt lever would cause the linear latches to move inwardly only minimally for a given incremental rotation of the winder. Most of this initial movement would be taken up with simply changing the orientation of the strap from straight (FIG. 2) to angled or tangential (FIG. 4). That is, initial movement of the tilt lever would tend to cause the strap to “take a tangential shortcut” and not result in linear movement of the strap in the sense of X degrees of rotation of the winder consistently resulting in Y inches of movement of the strap. Rather, the translation of winder rotation to latch movement would be quite non-linear, and this could be misleading or feel strange to the operator, who might only operate the tilt latch on rare occasion. The rationale for the housing, given the initial, unactivated orientation of the strap slot, can now be understood.
[0014] Another shortcoming of this type of actuator mechanism is that the housing can introduce additional friction on the strap, and this can result in binding of the mechanism and possibly strap breakage, over time.
[0015] Still another shortcoming of the strap type of “concurrent-latch” actuator discussed above is the strap itself, given that it can become twisted and bind at various locations within the sash, irrespective of whether a “housing” is employed.
[0016] It is to these dictates and shortcomings of the prior art that the present invention is directed. It is an actuator for a “concurrent-latch” sash retention mechanism which addresses these dictates and problems and provides solutions which make the invention a significant advance over prior art sash retention mechanism actuators of the “concurrent-latch” variety.
SUMMARY
[0017] The present invention is an actuator device for unlatching a sash tilt latch which is intended to maintain a window sash, such as in a double-hung window, in an intended path of reciprocation during opening and closing of the window. At the same time, however, the latch can be retracted to release the sash from its position in the defined path and allow it to be tilted for cleaning or removal. In a preferred embodiment, a pair of latches which extend oppositely in lateral directions are actuated by the structure. The actuator includes a housing which is mounted to the sash. A winder is rotatably connected to the housing and extends into an interior cavity within the sash. The winder has a longitudinal axis and forms a diametral slot. A flexible cord having a substantially round cross-section is slidably received within the winder slot. Ends of the cord are connected to the latches. As the winder is rotated in a particular direction, the cord coils around the winder to draw the latches inwardly. The sash is, thereby, released from the frame.
[0018] In a preferred embodiment of the invention, the winder includes a slit at its lower end, the slit extending through an imaginary vertical axis about which the winder rotates.
[0019] The flexible cord is received within the slit, and, in a preferred embodiment, the cord has a larger diameter than does at least a portion of the slit. A bulge in the slit above its narrowest portion does, however, have a diameter greater than that of the cord. Consequently, prongs defined on opposite sides of the slit can be urged apart to admit the cord into the bulge. With the cord received in the bulge, because of the bulge's greater diameter than that of the cord, the cord will be free to move through the bulge portion of the slit and will effectively equalize pressure applied to the oppositely facing tilt latches.
[0020] The present invention is thus improved apparatus to be employed in mounting and maintaining a sash within a window frame. More specific features and advantages obtained in view of those features will become apparent with reference to the accompanying drawing figures, the DETAILED DESCRIPTION OF THE INVENTION, and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a perspective pictorial view of a strap-type prior art sash retention mechanism actuator;
[0022] [0022]FIG. 2 is a bottom plan pictorial view of the prior art strap-type actuator of FIG. 1, with the winder in its unactivated position;
[0023] [0023]FIG. 3 is a bottom plan pictorial view of the prior art strap-type actuator of FIG. 1, with the winder in its activated position;
[0024] [0024]FIG. 4 is a bottom plan pictorial view of the prior art strap-type actuator of FIG. 1, with the housing removed and the winder in its activated position;
[0025] [0025]FIG. 5 is a perspective, exploded view of one type of latch assembly suitable for use with an actuator according to the present invention, including a pivoting “blade” and its supporting and related apparatus and structure, with the window sashes and actuator cord being shown in phantom, and some portions of the structure being broken away;
[0026] [0026]FIG. 6 is a front elevational view of the latch assembly of FIG. 5, as mounted within a window sash, showing the latch element in various positions;
[0027] [0027]FIG. 7 is an exploded perspective view of a combined window-lock/tilt-latch actuator assembly according to the present invention;
[0028] [0028]FIG. 8 is a top plan view of the combined windowlock/tilt-latch assembly of FIG. 7, with the sweep and tilt latch lever in their locked positions;
[0029] [0029]FIG. 9 is a top plan view of the combined windowlock/tilt-latch assembly of FIG. 7, with the tilt latch handle in its unlocked/activated position, and the sweep in its unlocked/activated position in phantom line;
[0030] [0030]FIG. 10 is a front elevational view of the assembly of FIG. 7, with the sweep and tilt latch handle in their locked/unactivated positions;
[0031] [0031]FIG. 11 is a bottom plan view of the assembly of FIG. 7;
[0032] [0032]FIG. 12 is an enlarged side elevational view of the cord-retaining end of a second embodiment of a winder according to the present invention, with the winder in its activated/unlocked position and the cord (in phantom) wrapped around the winder;
[0033] [0033]FIG. 13 is an enlarged view of the lower end of the winder of FIG. 12, again showing the cord in phantom but with the winder in its unactivated/locked position and with the cord not wrapped around the winder; and
[0034] [0034]FIG. 14 is a front elevational pictorial view of the actuator of the present invention in conjunction with a pair of latch assemblies mounted in a double-hung window.
DETAILED DESCRIPTION
[0035] The present invention, as discussed above, is directed to a “concurrent-latch” actuator for a sash retention mechanism.
[0036] Referring now to the drawings, wherein like reference numerals denote like elements throughout the several views, FIG. 5 is an exploded view illustrating dual sashes 20 , 22 of a double hung window and a pivoting blade 24 , which is intended to be recessed within a cavity 26 in the inner sash 20 . The cavity 26 in the sash 20 is overlain, on a side of the sash, by a face plate 28 mounted generally flush with the outwardly facing side surface 30 of the sash 20 . The face plate 28 is part of an end plate assembly 32 .
[0037] The figures illustrate a blade member 24 which is pivotally mounted for rotation about an axis generally transverse to a plane defined by the window sash 20 . It should be noted, however, that the actuator of the present invention, discussed below, could be used with other types of latch elements, including without limitation linearly acting latch elements as opposed to pivoting blade(s) 24 .
[0038] [0038]FIG. 5 illustrates a coil spring 38 which is shown as being connectable, at one end thereof, to a hook member 40 of the blade 24 . The other end of the coil spring 38 is connectable to the base 36 of the end plate assembly 32 . The coil spring 38 , thereby, biases the blade 24 for rotation, in a direction as seen in FIG. 5, in a clockwise direction.
[0039] A yoke member 42 is attached to the blade 24 to effect selective overcoming of the bias of the coil spring 38 in order to retract the blade 24 for a purpose discussed hereinafter. The yoke member 42 is illustrated as being constructed of a wire stock formed into a bail, opposite ends of which are passed through an aperture 44 provided in the blade 24 . The bail 42 thereby has an end, proximate the blade 24 , which serves to apply force to the blade 24 in a direction, as viewed in FIG. 5, counter clockwise so as to overcome the bias of the coil spring 38 . The wire from which the bail 42 is formed is provided with a narrow neck 46 at an end remote from blade 24 . The neck 46 defines a channel 48 which extends away from the blade 24 , when the bail 42 is connected to the blade 24 , to facilitate connection of an actuator mechanism. A remote end of the actuator is illustrated in FIG. 5. A segment of flexible filament or cord 50 is shown as extending through the narrowed channel 48 formed in the neck 46 , an end of the filament 50 having a sleeve 52 crimped onto the filament 50 . Typically, the sleeve 52 would have a diameter smaller than an expanded channel 54 formed within the bail 42 so that the filament 50 end, with the sleeve 52 crimped thereon, could be slid through the expanded channel 54 and then withdrawn into the narrowed channel 48 which would have a width smaller than the diameter of the sleeve 52 . The remainder of the actuator structure (i.e., the parts in addition to the filament or cord 50 ) is discussed in detail below.
[0040] [0040]FIG. 5 also illustrates a portion of a balance tube 56 which defines an elongated trough or track 58 into which blade 24 extends when in its non-fully-retracted position(s).
[0041] [0041]FIG. 5 illustrates a slot 64 formed in the balance tube 56 at the bottom of the trough 58 . This slot 64 is formed at a location such that, when the window sash mechanisms are in their closed positions, a corresponding slot 66 in the end plate assembly face plate 28 , through which the blade member 24 can extend, is registered with the slot 64 formed in the balance tube trough 58 .
[0042] [0042]FIG. 6 illustrates the blade 24 mounted to end plate assembly 32 . That figure shows a second position of the blade 24 in solid line and first and third positions of the blade 24 in phantom line.
[0043] The first position of the blade 24 is such that the blade 24 is fully retracted within sash cavity 26 . The third position of the blade 24 is one wherein the blade 24 not only extends into the trough 58 engaging the bottom thereof, as it does in its second position, but wherein the blade 24 extends fully to the bottom of the trough 58 and into and through the slot 64 formed in the bottom of the trough 58 .
[0044] When the blade member 24 is in its second position, it will ride in the trough 58 and facilitate raising and lowering of the window sash 20 . It serves as a track rider which rides on the track defined by trough 58 , and the thickness of the blade member 24 can be made so that there is a minimum, if any, wobble of the sash 20 relative to the window frame 62 of which balance tube 56 is a part. Because of the biasing of the blade 24 to the second position by the coil spring 38 , the blade 24 will tend to remain received within the trough 58 as long as action is not taken to operate the actuator in order to overcome the bias of the spring 38 and cause rotation of the blade 24 to its first position.
[0045] The bias of the spring 38 is sufficiently strong such that, when the sash 20 is moved to its closed position with the slots in the face plate 66 and bottom of the trough 64 registered, the blade 24 will extend into the slot in the trough 64 . This will effect an even more positive preclusion of movement of the sash 20 in a direction perpendicular to a plane defined by the window frame 62 . The sash 20 will, thereby, be even more securely disposed to deter unwanted removal.
[0046] As will be able to be seen then, unless some positive action is taken to move the blade 24 in a rotational manner to its first position, the blade 24 will be maintained in either its second or third positions. When it is desired, however, to remove or tilt the sash 20 , operation of the actuator means (described in detail below) can be initiated to overcome the bias of the coil spring 38 and rotate the blade 24 to its first position. With the blade 24 in this position, there will be no obstruction to rotation of the sash 20 out of its location between the frame 62 or, if desired, removal of the sash 20 .
[0047] An exemplary latch mechanism having been described, attention can now turn to the actuator structure that effects retraction of the latches. With reference to the exemplary latch elements disclosed above, the actuator structure permits volitional rotation of the blade 24 in the counter clockwise direction, as viewed in FIG. 5; and the other blade 24 (shown on the right side of FIG. 14) in the clockwise direction. The actuator structure includes means for inwardly drawing both ends of the filament 50 which in turn inwardly draw the yokes 42 to effect counter clockwise rotation of the left blade 24 and clockwise rotation of the right blade 24 . Of course, other types of latch elements (e.g., linear latch elements) could be used. The details of a preferred actuator are set forth below.
[0048] With reference to FIGS. 7 - 11 , a preferred embodiment of the tilt latch actuator of the present invention can now be described. As shown, the preferred actuator is actually employed in combination with an integrated lock/tilt latch assembly 70 for a double-hung window. And it will be assumed for the purpose of describing the preferred embodiment that the window is oriented in the typical fashion such that the sashes move up and down rather than side to side. But those skilled in the art will recognize that the present invention is not limited to double-hung windows or for that matter double-hung windows that are oriented in the typical up-and-down fashion.
[0049] Integrated lock/tilt latch assembly 70 includes, starting at the top of FIG. 7, a traditional rotatable sweep 72 (carried by the lower sash 20 ) that works in conjunction with a keeper (not shown) attached to the upper sash 22 to lock the lower sash 20 to the upper sash 22 when the sashes are in their fully closed positions and the sweep 72 is in its locked position, as shown in solid line in FIG. 9. Sweep 72 is rotatably supported by a housing 74 in conventional fashion, housing 74 having a generally smooth top surface for supporting the underside of the sweep 72 , and a variety of bosses, studs, etc. extending downwardly from its underside for accepting and supporting the various components of the integrated lock/tilt latch 70 .
[0050] Further with reference to FIG. 7, housing 74 provides a round aperture in its upper surface for receiving the sweep 72 . This aperture is located in the middle of the housing, side-to-side, and toward the front of the housing front-to-rear, with the front of the housing normally being mounted adjacent the inside of the room. Depending from the lower surface of the sweep 72 is a generally cylindrical stud 76 that is round at its upper end; has a pair of opposed flats 78 in its middle section; and a reduced diameter round tip 80 at its lower end. After the stud 76 is inserted into the sweep aperture in the housing, a washer-like retainer 82 is fixed to the lower tip 80 of the stud 76 , the retainer 82 serving to hold the sweep 72 against the housing 74 .
[0051] A leaf spring 84 is mounted within the housing 74 in such a way as to resiliently act on the flats 78 in the middle section of the sweep stud 76 , so as to tend to maintain the sweep 72 in either its fully unlocked or open position (as shown in phantom line in FIG. 9) or its fully locked or closed position (as shown in solid line in FIG. 9). That is, leaf spring 84 acts against one flat 78 or the other, depending on whether the sweep 72 is fully closed or fully open, to tend to keep the sweep 72 in that position. If the user wishes to rotate the sweep 72 from one position to the other, he or she must overcome the relatively small spring force created by the spring 84 .
[0052] Still referring to FIG. 7, the underside of the housing 74 also supports a tilt lever 66 . The top surface of the tilt lever 86 can carry a short upwardly extending stud (not shown) that can fit within a boss 88 depending from the housing 74 . Tilt lever 86 can rotate relative to housing 74 , and in fact includes a handle portion 90 that is accessible through a cutout 92 in the rear edge of the housing. Handle portion 90 can include a raised lip 94 on its upper surface, so that the operator can easily get a finger or tool into the cutout 92 and push against the raised lip 94 to initiate the rotation of the tilt lever 86 . Once handle portion 90 has “escaped” cutout 92 , the operator can gain additional purchase by grasping progressively longer portions of handle 90 . As shown in FIG. 9, tilt handle 90 is rotated counter clockwise to actuate the tilt latches 24 .
[0053] Extending downwardly from the tilt lever is a thin rectangular element 96 that resembles the operating tip of a standard slotted screwdriver.
[0054] Tilt lever 86 and the other components mounted to the underside of housing 74 are vertically held in place by a base plate 98 that is fastened to the housing 74 in conventional fashion (e.g., threaded fasteners, staking, rivets). Base plate 98 , in plan view, has the same overall shape as housing 74 , except that base plate 98 does not have a cutout similar to cutout 92 for access to the handle portion 90 of the tilt lever 86 . Base plate 98 is smooth and flat on its bottom surface, to accommodate mounting to sash 20 .
[0055] Extending downwardly from the baseplate 98 , and mounted for rotation relative thereto, is a cylindrical tube-like winder 100 . That is, winder 100 is supported at its upper end by baseplate 98 , and there is no “housing” at the lower end of the winder 100 as in the case of certain prior art actuator mechanisms. Reference is again made to FIG. 1, which shows a prior art winder mechanism having a housing at the lower end of the mechanism to support the winder cylinder. The longitudinal axis of winder 100 about which it rotates, is oriented vertically when the assembly 70 is mounted in typical fashion.
[0056] At the lower end of winder 100 is a slit 102 extending through an imaginary vertical axis about which winder 100 rotates. (Slit 102 is typically “vertical” in this description only because it is assumed for the sake of convenience that the double-hung window is oriented in a conventional, vertical manner, with the sashes moving up and down.)
[0057] Slit 102 is preferably widest at its very lowest point (i.e., at the lower tip of the winder), and narrows or converges as it extends upwardly, until it reaches a point up the winder where it generally attains a constant width, with one exception. At a small distance above the top of the triangular converging portion of the slit there can be a rounded “bulge” 104 in the slit, for purposes to be described below. And the slit 102 continues above the “bulge” for another small distance. This additional slit, or slit extension, above the bulge 104 , can give the structure some degree of springiness, so as to assist in accepting and retaining the cord or filament 50 , as further described below. Slit 102 splits the lower end of winder 100 into two “tines” that are resiliently biased toward one another by virtue of the natural resilience of the material fabricated into the two-tine geometry shown and described herein.
[0058] Importantly, slit 102 is oriented such that it is generally perpendicular to the panes of glass in the sashes 20 , 22 when the tilt handle 86 is in its unactivated position, e.g., as shown in FIG. 10. Tilt handle 86 is in an activated position in FIG. 9, i.e., when it is extending away from the rearward edge of the housing 74 and the handle portion 90 is no longer confined within the cutout 92 such as when it is in its unactivated state or position.
[0059] With reference to FIG. 12, the top of the winder 100 ′ also forms a slit 106 for accepting the rectangular element 96 extending downwardly from the tilt lever 86 . When element 96 is engaged with slit 106 , rotation of tilt lever 86 causes winder 100 to rotate about its longitudinal (in this case vertical) axis. It should be noted that the winder 100 ′ shown in FIGS. 12 and 13 is slightly different from the winder 100 shown in FIGS. 7 - 11 , and hence is labeled 100 ′ for the sake of clarity. The main difference between winder 100 and 100 ′ is the cord slit 102 and 102 ′, respectively, as further discussed below.
[0060] The cord or filament 50 can be received within slit 102 , 102 ′, depending upon the particular embodiment involved. In either case, however, the slit 102 , 102 ′ will have a portion, through which the cord 50 must be passed, to be received within the bulge 104 , 104 ′. With the cord 50 received within the bulge 104 , 104 ′, the cord will freely pass back and forth through the bulge 104 , 104 ′ of the winder 100 . As the winder 100 is rotated, the cord 50 will be coiled about the winder 100 . Because of the relative dimensions of the cord 50 and the bulge 104 , 104 ′, pressure brought to bear upon each tilt latch assembly 70 will be equalized.
[0061] The “bulge” 104 in the winder slit 102 is located roughly at the midpoint between the lower tip of the winder 100 and the upper extent of the slit. Slit 102 is preferably less wide than the distance of the cord 50 , while the bulge 104 is preferably wider than the diameter of cord 50 . That is, the dimensions of slit 102 are slightly smaller than the diameter of cord 50 except at the bulge 104 . These relative dimensions are selected to retain cord 50 in a particular, preferred way: cord 50 has to be pushed up into the lower portion of the slit 102 , causing the “tines” of the winder 100 to separate slightly to permit the cord to be pushed up into and received within the bulge 104 . Once so located, cord 50 , since slightly smaller in diameter than the generally round bulge 104 , can slide freely therein in a lateral direction (in a lateral direction, i.e., back and forth in a direction perpendicular to the longitudinal axis of the winder). This permits the actuator to be self-balancing, so that if there is a temporary imbalance as between the force on one end of the cord 50 as compared to the other end, then the cord 50 will slide within the bulge 104 at the start of the winding process so as to balance out the difference in force on the ends of the cord 50 .
[0062] This sliding of the cord 50 in the bulge 104 is very useful in terms of permitting a single actuator to actuate dual blades 24 . Such a configuration is shown in FIG. 14.
[0063] It should again be emphasized that virtually any type of latch element could be used with the actuators of the present invention. The present invention is not limited to pivoting blades such as described herein.
[0064] Also, the actuator of the present invention could be in the form of a separate device, and needn't be integrated into the window lock as in the preferred embodiment described herein.
[0065] [0065]FIG. 13 shows an alternative type of slit 102 ′ in the winder 100 ′ This slit 102 ′ has the “bulge” 104 ′ located at the very apex of the slit 102 ′, in contrast to slit 102 shown in FIGS. 7 - 11 , wherein the bulge 104 is located approximately midway between the bottom and the top of the slit 102 . Also, slit 102 ′ is tapered all the way from its lower end to its upper end. The bulge 104 ′ is again slightly larger than the cord 50 , so that the cord can freely slide in the bulge 104 ′ to self balance the ends of the cord 50 .
[0066] [0066]FIGS. 12 and 13 also illustrate small relieved areas or “scallops” 110 on the slits adjacent the bulge 104 ′, which relieve bending stress on the cord 50 , to reduce the likelihood that the cord 50 will prematurely break. The scallops 110 also help the cord to freely slide within the bulge 104 ′ during the self balancing process discussed above. It should be noted that scallops 110 could be used with winder 100 as well. The winder 100 ′ shown in FIGS. 12 and 13 is a solid circular rod as opposed to the tubular winder 100 of FIGS. 7 - 11 .
[0067] [0067]FIG. 14 shows how the self balancing process works. If the cord becomes prematurely taut on the right end because there is slack on the left end, this will cause the cord to slide within the bulge 104 to balance out the actuator system. This prevents one latch 24 from completely retracting into the sash 20 , while the other latch 24 remains only partially retracted.
[0068] It will be understood that this disclosure, in many respects, is only illustrative. Changes may be made in details, particularly in matters of shape, size, material, and arrangement of parts without exceeding the scope of the invention. Accordingly, the scope of the invention is as defined in the language of the appended claims.
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An actuator structure for concurrently unlatching a pair of sash tilt latches. The actuator structure includes a housing mounted to a sash which slides within a window frame, a winder rotatably connected to the housing and extending into an interior of the sash, the winder having a diametral slot therein. The actuator structure further includes a filament slidingly received within the slot with ends of the filament connected to the latches. As the winder is rotated in a first direction, the filament coils around the winder to draw the latches inwardly, thereby releasing the sash from the frame.
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TECHNICAL FIELD OF THE INVENTION
The present invention relates to a guide device comprising a rail and a slide which are mounted such that they can move relative to one another and to a turbojet engine nacelle equipped with such a system.
BRIEF DISCUSSION OF RELATED ART
An airplane is propelled by one or more propulsion units comprising a turbojet engine housed in a tubular nacelle. Each propulsion unit is attached to the airplane by a strut generally situated under a wing or at the fuselage.
A nacelle generally has a structure comprising an air inlet upstream of the engine, a central section intended to surround a fan of the turbojet engine, and a downstream section intended to surround the combustion chamber of the turbojet engine and housing thrust reversal means.
The air inlet comprises, on the one hand, an inlet lip designed to allow optimum funneling toward the turbojet engine of the air needed to be fed to the fan and to the internal compressors of the turbojet engine and, on the other hand, a downstream structure to which the lip is attached and which is intended to channel the air suitably toward the fan blades, said downstream structure comprising an external shell ring and an internal acoustic panel. The assembly is attached upstream to a fan casing that forms part of the central section of the nacelle.
The central structure surrounds the fan and is generally broken down into an internal wall that forms said fan casing and an external wall in the form of removable cowls pivotably mounted about a longitudinal axis that forms a hinge at the upper part (in the 12-o'clock position) of the nacelle so as to allow access to the inside of the nacelle.
The way in which these various elements (moving cowls, casing, air inlet lip, external shell ring, acoustic panel) are joined together gives rise to numerous breaks in aerodynamic continuity owing to the presence of offsets and gaps between these elements which are inherent to the fact that they are joined together. What is more, the moving cowls are mounted on hinges, which also give rise to aerodynamic disturbances.
A solution for improving the aerodynamic continuity of the external surface of a nacelle is covered in the as-yet unpublished French patent applications No. 06/08599 and No. 07/01256.
This solution consists in incorporating the air inlet lip into the external shell ring, including therein all or part of the cowl that surrounds the fan casing, so as to form a one-piece structure.
Advantageously, this structure is fitted with translational guidance means of the rail/slide type allowing said cowl easily to be opened and providing access to the inside of the nacelle.
Advantageously too, these guide means may be dismantled so as to allow said structure to be removed and possibly replaced.
It will therefore be appreciated that the rail/guide systems need to be fitted with end-of-translation retaining means (end-of-travel end stops) which nonetheless allow a disengaged position that will allow the rail/slide system to be dismantled.
These end-of-travel end stops for the end of travel of the moving external cowl need to be able to be retracted so that the moving external structure can be replaced, while at the same time returning to an operational state without fail when an external cowl is refitted.
Known ways of achieving this include various end-of-travel spoiler systems for a rail with rolling runners that entail maneuvering the cowl in a special way in order to allow it to be disengaged, or alternatively end stop means.
Nonetheless, these systems do not generally meet the need for ease of access and ease of maneuvering of the end stop means and there is a need for an improved locking system.
BRIEF SUMMARY OF THE INVENTION
The invention alleviates the abovementioned disadvantages and proposes an improved retaining system and for that reason the present invention comprises a guide device for a translationally moving part of a turbojet engine nacelle and comprising, on the one hand, a rail mounted fixedly on a part of the nacelle and, on the other hand, and a slide attached to the moving part and able to slide along the rail, where said guide device is equipped with an in-built retractable system for stopping the translational movement of the slide, and comprising, in order to do this, on the one hand at least one immobilizing means mounted such that it can move on the rail and able to move alternately from an engaged position in which it constitutes a translational end stop for the slide and a disengaged position in which it is away from the slide and allows a relative translational movement of the latter beyond said locking system and, on the other hand, at least one control means for controlling the immobilizing means.
In general, a rail means the male part of the rail/slide system and the term slide denotes the female part.
Thus, by equipping the rail with retractable end stops there is obtained a locking system that is simple to activate, that meets the demanded safety requirements while at the same time allowing the rail and the slide to be dismantled from one another when necessary in order to remove moving parts.
It will also be noted that, in the application in question, it is advantageous to keep the rail fixed, which allows better guidance and better fixing. Further, the fact that the rail is fixed means that the locking and control means can be arranged in a special way.
Advantageously, the immobilizing means is fixed at a first end of the rail. Thus, the immobilizing means is able to form an end-of-travel end stop giving the slide the greatest possible margin for maneuver.
Advantageously too, the control means is mounted at a second end of the rail.
As a preference, the control means is able to be returned from an unlocked position to a locked position during the return of the slide, thereby causing the immobilizing means to return to its engaged position. In this way, reengaging the slide with the rail when the removed panel is returned to its position causes the immobilizing means to be returned automatically to their engaged position. This results in a significant additional safety feature by making it possible to prevent any omission to reactivate the locking system on the part of the operator.
Advantageously, the control means has two stable positions and is mounted against the action of an elastic return means which, when the control means is between two stable positions, tends to return it toward one or other of the positions.
According to a preferred embodiment of the invention, the immobilizing means is in the form of a heel piece mounted such that it can pivot on the rail.
In addition, the guide device comprises a connecting means connecting the control means to the immobilizing means.
As a preference, the rail is hollow and houses all or part of the connecting means.
Advantageously, the immobilizing means is mounted against the action of at least one elastic return means that tends to return it toward its engaged or disengaged position.
Advantageously too, the connecting means is a rod mounted with the capacity for translational movement and able to be moved, under the effect of the control means, alternately between a first position in which it keeps the immobilizing means in its position in which the elastic return means is stressed, and a second position in which the elastic return means is at rest.
The present invention also relates to a nacelle for a turbojet engine comprising an air inlet structure able to channel an air flow toward a fan of the turbojet engine and a central structure intended to surround said fan and to which the air inlet structure is attached, the air inlet structure and possibly the central structure having at least one external panel comprising a one-piece wall, characterized in that the external panel is mounted with the capacity for translational movement with the aid of a guide system according to the invention.
Advantageously, the rail of the guide device is secured to a fixed part of the nacelle while the slide is connected to the moving external panel.
BRIEF DESCRIPTION OF THE DRAWINGS
The way in which the invention is implemented will be better understood from the detailed description which is set out hereinbelow with reference to the attached drawing, in which:
FIGS. 1 and 2 are sectioned partial schematic depictions of an air inlet structure of a turbojet engine nacelle equipped with a guide system according to the invention.
FIG. 3 is a schematic depiction of the guide system according to the invention, in the position in which the external cowl is locked and closed.
FIG. 4 is a schematic depiction of the guide system according to the invention, in the position in which the external cowl is locked and open.
FIG. 5 is a schematic depiction of the guide system according to the invention, in the position in which the external cowl is unlocked and open.
FIG. 6 is a schematic depiction of the guide system according to FIG. 5 and in which the external cowl is in the process of being removed.
FIG. 7 is a schematic depiction of the guide system according to FIG. 5 and in which the external cowl is in the process of being refitted, and
FIG. 8 is a schematic depiction of the guide system at the end of the refitting of the external cowl with the locking means returned to the engaged position.
DETAILED DESCRIPTION OF THE INVENTION
A nacelle (not depicted) constitutes a tubular housing for a turbojet engine and channels the air flows that it generates defining the internal and external aerodynamic lines necessary to obtain optimal performance. It also houses various components necessary for the operation of the turbojet engine, together with ancillary systems such as a thrust reverser.
The nacelle is intended to be attached to a fixed structure of an airplane, such as a wing, via a pylon.
More specifically, a nacelle has a structure comprising a front section that forms an air inlet 4 , a central section 5 intended to surround a fan of the turbojet engine, and a rear section (not visible) surrounding the engine of the turbojet engine and generally housing a thrust reversal system.
The air inlet 4 splits into two zones, namely, on the one hand, an inlet lip 4 a designed optimally to funnel toward the turbojet engine the air needed to be fed to the fan and to the internal compressors of the turbojet engine and, on the other hand, a downstream structure 4 b comprising an external panel 40 and an internal panel 41 and to which the lip 4 a is attached and which is intended to channel the air suitably toward the fan blades.
The central section also breaks down into an external wall and an internal wall comprising a casing of the fan.
A nacelle that has an air inlet structure as depicted in FIGS. 1 and 2 has a lip 4 a incorporated into the external panel 40 , it being possible for said external panel also to incorporate, at least in part, the external wall of the central structure 5 . The external wall 40 and the air inlet lip 4 a therefore form a single dismantlable component extending over the entire upstream part of the nacelle. The internal panel 41 for its part is attached upstream of the fan casing via fixing flanges.
The external panel 40 may be modular and comprise a plurality of longitudinal external panels each defining a portion of the external wall of the nacelle. In such a case, the external structure of the nacelle will have meeting lines running longitudinally with respect to the nacelle, and these will have only a negligible impact on the aerodynamic continuity of the air inlet structure 4 , unlike a nacelle according to the prior art that has a peripheral meeting line where the external panel 40 meets the lip 4 a and where the external panel 40 meets the external panel of the central section 5 , said meeting line running transversely with respect to the direction of the air flow.
As shown in FIGS. 1 and 2 , the external panel is mounted with the capacity for translational movement along a substantially longitudinal axis of the nacelle to make it easier to remove and/or to replace.
This translational movement is performed by virtue of the installation of guide means 100 according to the invention, comprising a rail 101 collaborating with a slide 102 .
The present invention will be illustrated by a guide system 100 comprising a rail 101 fixedly mounted on the internal wall 41 and a slide 102 fixedly connected to the external panel 40 . Quite clearly, the present application is not restricted to such a configuration and it is entirely possible for the invention to be extended to cover a rail fixed to the moving external panel and collaborating with a fixed slide of the nacelle; or alternatively to use a rail with rollers, for example.
As explained, a nacelle as described hereinabove allows simple opening of the entire upstream section of the nacelle but also at the same time allows said external panel 40 to be removed.
As a result, the guide system 100 needs to allow the slide to be halted at the end of its travel when the external panel 40 is simply being opened, but needs also to be able to allow an over-travel of the slide 102 so that it can be disengaged from the rail 101 and the external panel can be removed.
The present invention aims to provide such a guide system 100 which is depicted during the course of various steps in FIGS. 3 to 8 .
As previously stipulated, a guide system 100 comprises a rail 101 on which there is mounted a slide 102 capable of translational movement along said rail 101 .
The rail 101 is hollow and incorporates a retractable translational immobilization system.
For this, the rail 101 has a first end 103 in which two heel pieces 104 are mounted facing one another.
Each heel piece 104 has a first end 104 a forming a pivot and via which it is mounted on an axis of rotation against the wall of the rail 101 and a second end 104 b that projects from the first end 103 of the rail 101 forming a return 105 able to project laterally from the rail 101 when the heel piece 104 is pressed against the wall of the rail 101 (engaged position) but not protruding laterally beyond the rail 101 when the heel pieces are sufficiently far away from the wall of the rail 101 (disengaged position).
The heel pieces 104 are connected to one another by a spring 106 that constitutes an elastic return means that tends to return them to their disengaged position. Alternatively, it is equally possible to imagine equipping each heel piece 104 with a spring mounted against the wall of the rail 101 and tending to push them away from said wall.
Each heel piece 104 has, at its end 104 b , a beveled face 107 intended to collaborate with a corresponding frustoconical end 121 of a connecting rod 120 mounted with the capacity for translational movement inside the rail 101 and able to move alternately from a first position in which the frustoconical end acts as an end stop for the heel pieces 104 and keeps them in their engaged position against the action of the spring 106 , to a second position in which the frustoconical end 121 is away from the heel pieces 104 and allows them, under the effect of the spring 106 , to return toward their disengaged position.
The rod 120 is made to move between its two positions by means of a trigger 130 positioned at a second end 108 of the rail 101 .
The trigger 130 is mounted such that it can rotate between two stable positions and is connected to the rod 120 by a link 131 .
The trigger 130 is also connected to an elastic return means 132 allowing it to be kept in each of the two stable positions and to be returned to one of its two positions when it is in an unstable intermediate position.
The two stable positions of the trigger 130 are determined in such a way that, on the one hand, when actuated into its first stable position, the trigger 130 , via the link 132 , drives the rod 120 into its position of separation from the heel pieces 104 which then move into the disengaged position and, on the other hand, when actuated into its second stable position, the trigger 130 via the link 132 returns the rod 120 to its position of engagement with the heel pieces 104 which, as explained hereinabove, are then kept in their engaged position.
It will also be noted that the trigger is equipped with an extension 133 arranged in such a way that it projects laterally from the rail 101 when the heel pieces 104 are in the disengaged position.
The various steps in implementing the guide system 100 and its in-built locking system will now be explained with the aid of FIGS. 3 to 8 .
FIG. 3 illustrates the guide system 100 in its initial position when the external panel 40 is closed and the heel pieces 104 are in their engaged position.
In this position, the slide 102 is retreated toward the second end 108 of the rail 101 . As for the in-built immobilizing system, the heel pieces 104 are kept in the engaged position, that is to say in the position in which they project laterally from the rail 101 , by the end 121 of the rod 120 . The trigger 130 is in the corresponding stable position.
FIG. 4 illustrates the guide system 101 in the case of simple opening of the external panel 40 without its removal. In this configuration, the heel pieces 104 are still in the engaged position and the slide 102 has slid toward the first end 103 of the rail 101 until possibly it has come into abutment against the return 105 of the heel pieces 104 .
FIGS. 5 to 8 illustrate the steps involved in completely removing and possibly replacing the external panel 40 .
To do this, the trigger 130 is pivoted by hand or through an electric control into its second stable position.
It will be noted that the locking means are located at one end of the rail while the control means are located at the second end. This is because such positioning is advantageous because it allows ease of access to the control means, the moving cowl 40 beginning to open from the side at which the control means are located.
As this happens, the link 132 transmits this movement to the rod 120 which undergoes a slight translational movement until the frustoconical end 121 has moved away from the heel pieces 104 to allow them, under the effect of the spring 106 , to return to their disengaged position.
Thus, the returns 105 of the heel pieces 104 no longer project laterally from the rail 101 and the slide 102 is free to continue its travel as illustrated in FIG. 6 so that the rail 101 and the slide 102 can be disengaged, allowing the external panel 40 to be removed.
As illustrated in FIG. 7 , the external panel 40 or a new panel is refitted by performing the procedure in reverse.
However, as is depicted in FIG. 8 , the locking system is able automatically to return to the engaged position once the external panel 40 has been refitted.
What happens is that when the external panel 40 is returned to the closed position, the slide 102 undergoes a translational movement along the rail 101 toward its second end 108 where the extension 133 of the trigger projects laterally from the wall of the rail 101 .
As the external panel 40 is returned to the closed position, the slide butts against said extension 133 of the trigger and pushes it back, thus causing the trigger 130 to return to its first stable position and, as a result, causing the heel pieces 104 to reengage.
The external panel 40 is manipulated in the conventional way using suitable tooling mounted on lifting points, advantageously situated near the center of gravity of the wall. Hence it is easy to perform a pivoting by hand in order to fit and remove said one-piece wall. Optionally, the lifting point may be situated inside a casing of a latch.
Although the invention has been described in conjunction with specific exemplary embodiments, it is quite obvious that it is not in any way restricted thereto and that it comprises all technical equivalents of the means described and combinations thereof where these fall within the scope of the invention.
In particular, it would be possible to provide retractable end stops of different shapes. It will also be noted that the present guide system is not limited to an air inlet external panel but could also be applied to the guidance of any moving part of a nacelle.
It will finally be noted that the locking system according to the invention may be combined with an electric drive and control system, possibly associated with a sensor to detect that the external panel has been re-closed.
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The invention relates to a guiding device ( 100 ) for part of a jet engine nacelle that can move in translation, comprising: (i) a rail ( 101 ) fixedly mounted on part of the nacelle, and (ii) a slide ( 102 ) which is connected to the mobile part and which can slide along the rail. The invention is characterized in that the guiding device is provided with a built-in retractable system for preventing the translational movement of the slide, for which purpose the device includes: (i) at least one blocking means ( 104 ) mounted such that it can move on the rail and occupy alternatively an engaged position in which it forms a translational abutment for the slide and a released position in which it is moved away from the slide and enables the relative translational movement of the slide beyond the locking system, and (ii) at least one means ( 130 ) for controlling the blocking means.
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RELATED APPLICATIONS
[0001] This application is a 371 application of PCT/JP2009/000494 having an international filing date of Feb. 9, 2009, which claims priority to JP2008-030255 filed on Feb. 12, 2008 and JP2008-030256 filed on Feb. 12, 2008, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a battery housing tray capable of safely housing a plurality of batteries in which, even if faults such as heat generation occur in a battery due to trouble in manufacturing facilities and the like during a manufacturing process of batteries, the faults do not affect other batteries, and to an assembled battery housing tray using the battery housing tray.
BACKGROUND ART
[0003] Recently, from the viewpoint of resource savings and energy savings, demands for secondary batteries employing nickel hydrogen, nickel cadmium or lithium ions, which can be used repeatedly, are increased. Among them, the lithium ion secondary battery has a high electromotive force and a large energy density although it has light weight. Therefore, the demand for the lithium ion secondary battery is expanded as a driving power source for various types of portable electronic apparatuses and mobile telecommunication apparatuses, for example, portable telephones, digital cameras, video cameras, and notebook-sized personal computers, and the like.
[0004] Generally, in a manufacturing process of secondary batteries, after batteries are assembled in the form of a battery itself, various treatment processes to obtain battery property are carried out, and then the batteries are commercialized. At that time, the treatment processes such as an initial charging and discharging process, an aging process, and a pre-shipment charging and discharging process are carried out. Thus, the presence or absence of a minor internal short circuit in a battery or functions of components constituting a battery are inspected, and a secondary battery having high performance and high reliability is provided. Such treatment processes are carried out in a state in which a plurality of batteries are housed in a tray in consideration of productivity.
[0005] However, in the above-mentioned treatment processes, an internal short circuit may occur in a battery, or an abnormal voltage may be applied to a battery because of a fault in a charging and discharging tester, and the like. In this case, in such batteries, abnormal heat generation or gas release due to rapid increase in the internal pressure of the battery can occur. At such a time, a safety mechanism provided in the battery cannot sufficiently work, and explosion or ignition may occur on rare occasion.
[0006] An example is disclosed in which batteries housed in a tray are monitored by an infrared ray monitor, a battery with abnormal heat generation is discriminated and eliminated in a charging and discharging process (see, for example, Patent Document 1).
[0007] Furthermore, an example is disclosed in which abnormality is detected by an odor sensor, a temperature sensor, and the like, and an inert gas or a fire-extinguishing agent is ejected to a whole device including a tray, thus preventing ignition or explosion of a battery from spreading, when a fault occurs in a battery housed in the tray in a charging and discharging process or an aging process (see, for example, Patent Documents 2 and 3).
[0008] In a temperature measurement device described in Patent Document 1, when heat generation occurs in a secondary battery housed in a tray, a battery with heat generation can be eliminated so as to prevent the influence on other batteries. However, Patent Document 1 does not describe a mechanism for preventing the influence on other batteries when a battery is abnormally heated and ignition or explosion occurs.
[0009] Furthermore, in Patent Documents 2 and 3, when a battery with a fault causes ignition or explosion in a battery depository or chamber space for carrying out a charging and discharging test, a fire-extinguishing agent is filled in the battery depository or the chamber space so as to extinguish the fire. Therefore, normal batteries existing in the battery depository or the chamber space are required to be disposed of or subjected to regenerating process when they are not disposed of. Furthermore, there is a problem that all charging and discharging devices in the battery depository or the chamber space become unusable. Furthermore, since the fire may be beyond the extinguishing ability of the facilities when the fire spreads, it is necessary to extinguish the fire while the fire is small.
Patent Document 1: Japanese Patent Unexamined Publication No. H10-281881 Patent Document 2: Japanese Patent Unexamined Publication No. H11-169475 Patent Document 3: Japanese Patent Unexamined Publication No. 2003-190312
SUMMARY OF THE INVENTION
[0013] A battery housing tray of the present invention houses a plurality of batteries each having a vent mechanism. The battery housing tray includes a housing member having an outer peripheral frame with a height exceeding a height of each of a plurality of batteries, and a bottom part; a barrier rib member configured to individually house the batteries in the housing member; and an opening opposite the bottom part. In the configuration, a height of the barrier rib member is more than 50% of the height of each of the batteries and less than the height of the outer peripheral frame of the housing member, and the batteries are housed in a manner that a vent mechanism side of each of the batteries faces the opening.
[0014] With such a configuration, it is possible to achieve a battery housing tray that is excellent in safety in which a flame produced by ignition of gas ejected from a vent hole of one of the batteries with a fault is dispersed in space above the barrier rib member, thus preventing the flame from spreading to the surrounding batteries or abnormally overheating in advance.
[0015] Furthermore, an assembled battery housing tray of the present invention has a configuration in which the above-mentioned battery housing trays are stacked. Thus, it is possible to achieve an assembled battery housing tray with safety and high reliability in which even when a plurality of battery housing trays are stacked in multiple stages, fire is less likely to spread.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a cross-sectional view of a battery housed in a battery housing tray in accordance with a first exemplary embodiment of the present invention.
[0017] FIG. 2A is a perspective view of the battery housing tray in accordance with the first exemplary embodiment of the present invention.
[0018] FIG. 2B is a sectional view taken along line 2 B- 2 B of FIG. 2A .
[0019] FIG. 3A is a perspective view of another example of a battery housing tray in accordance with the first exemplary embodiment of the present invention.
[0020] FIG. 3B is a sectional view taken along line 3 B- 3 B of FIG. 3A .
[0021] FIG. 4A is a perspective view of a battery housing tray in accordance with a second exemplary embodiment of the present invention.
[0022] FIG. 4B is a sectional view taken along line 4 B- 4 B of FIG. 4A .
[0023] FIG. 5A is a plan view of a battery housing tray seen from the upper part in accordance with a third exemplary embodiment of the present invention.
[0024] FIG. 5B is a sectional view taken along line 5 B- 5 B of FIG. 5A .
[0025] FIG. 6 is a sectional view to illustrate an assembled battery housing tray in accordance with a fourth exemplary embodiment of the present invention.
[0026] FIG. 7A is a sectional view showing another example of an assembled battery housing tray before battery housing trays are stacked in accordance with the fourth exemplary embodiment of the present invention.
[0027] FIG. 7B is a sectional view showing another example of an assembled battery housing tray after battery housing trays are stacked in accordance with the fourth exemplary embodiment of the present invention.
[0028] FIG. 8A is a transparent plan view of an assembled battery housing tray seen from the upper part in accordance with a fifth exemplary embodiment of the present invention.
[0029] FIG. 8B is a sectional view taken along line 8 B- 8 B of FIG. 8A .
[0030] FIG. 9A is a perspective view of a battery housing tray in accordance with a sixth exemplary embodiment of the present invention.
[0031] FIG. 9B is a sectional view taken along line 9 B- 9 B of FIG. 9A .
[0032] FIG. 10A is a perspective view of another example of a battery housing tray in accordance with the sixth exemplary embodiment of the present invention.
[0033] FIG. 10B is a sectional view taken along line 10 B- 10 B of FIG. 10A .
[0034] FIG. 11A is a perspective view of a battery housing tray in accordance with a seventh exemplary embodiment of the present invention.
[0035] FIG. 11B is a sectional view taken along line 11 B- 11 B of FIG. 11A .
[0036] FIG. 12A is a plan view of a battery housing tray seen from the upper part in accordance with an eighth exemplary embodiment of the present invention.
[0037] FIG. 12B is a sectional view taken along line 12 B- 12 B of FIG. 12A .
[0038] FIG. 13A is a sectional view showing an assembled battery housing tray before battery housing trays are stacked in accordance with a ninth exemplary embodiment of the present invention.
[0039] FIG. 13B is a sectional view showing an assembled battery housing tray after battery housing trays are stacked in accordance with the ninth exemplary embodiment of the present invention.
[0040] FIG. 14A is a sectional view showing another example 1 of an assembled battery housing tray before battery housing trays are stacked in accordance with the ninth exemplary embodiment of the present invention.
[0041] FIG. 14B is a sectional view showing another example 1 of an assembled battery housing tray after battery housing trays are stacked in accordance with the ninth exemplary embodiment of the present invention.
[0042] FIG. 15 is a sectional view showing another example 2 of an assembled battery housing tray in accordance with the ninth exemplary embodiment of the present invention.
[0043] FIG. 16A is a sectional view showing another example 1 of a first barrier rib member and a second barrier rib member of the battery housing tray in accordance with the ninth exemplary embodiment of the present invention.
[0044] FIG. 16B is a sectional view showing another example 2 of a first barrier rib member and a second barrier rib member of the battery housing tray in accordance with the ninth exemplary embodiment of the present invention.
[0045] FIG. 17A is a transparent plan view of an assembled battery housing tray seen from the upper part in accordance with a tenth exemplary embodiment of the present invention.
[0046] FIG. 17B is a sectional view taken along line 17 B- 17 B of FIG. 17A .
[0047] FIG. 18A is a sectional view to illustrate a form of air holes applied in the exemplary embodiments of the present invention.
[0048] FIG. 18B is a sectional view to illustrate a form of air holes applied in the exemplary embodiments of the present invention.
[0049] FIG. 18C is a sectional view to illustrate a form of air holes applied in the exemplary embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0050] Hereinafter, exemplary embodiments of the present invention are described with reference to drawings in which the same reference numerals are given to the same components. Note here that the present invention is not limited to the embodiments mentioned below as long as it is based on the basic features described in the description. Furthermore, in the below description, a non-aqueous electrolyte secondary battery (hereinafter, referred to as a “battery”) such as a lithium ion battery is described as an example of a battery. Needless to say, however, the battery is not necessarily limited to this example.
First Exemplary Embodiment
[0051] FIG. 1 is a cross-sectional view showing a battery housed in a battery housing tray in accordance with a first exemplary embodiment of the present invention.
[0052] As shown in FIG. 1 , a cylindrical battery has electrode group 4 in which positive electrode 1 provided with positive electrode lead 8 made of, for example, aluminum, and negative electrode 2 facing positive electrode 1 and provided with negative electrode lead 9 made of, for example, copper at one end are wound together with separator 3 interposed between positive electrode 1 and negative electrode 2 . Then, insulating plates 10 a and 10 b are mounted on the upper and lower parts of electrode group 4 , which are inserted into battery case 5 . The other end of positive electrode lead 8 is welded to sealing plate 6 and the other end of negative electrode lead 9 is welded on the bottom part of battery case 5 . Furthermore, a non-aqueous electrolyte (not shown) conducting lithium ion is injected into battery case 5 . Then, an open end of battery case 5 is caulked with respect to positive electrode cap 16 , current blocking member 18 such as a PTC element, and sealing plate 6 via gasket 7 . Furthermore, positive electrode cap 16 is provided with vent hole 17 for extracting a gas generated when vent mechanism 19 is opened due to a fault in electrode group 4 . Positive electrode 1 includes positive current collector 1 a and positive electrode layer 1 b containing a positive electrode active material.
[0053] Herein, positive electrode layer 1 b includes a lithium-containing composite oxide such as LiCoO 2 , LiNiO 2 , and Li 2 MnO 4 or a mixture thereof or a composite compound thereof, as a positive electrode active material. Positive electrode layer 1 b further includes a conductive agent and a binder. An example of the conductive agent may include graphites such as natural graphites and artificial graphites; and carbon blacks such as acetylene black, Ketjen black, channel black, furnace black, lampblack, thermal black, and the like. Furthermore, an example of the binder includes PVDF, polytetrafluoroethylene, polyethylene, polypropylene, aramid resin, polyamide, polyimide, and the like.
[0054] As positive current collector 1 a used in positive electrode 1 , aluminum (Al), carbon, conductive resin, and the like, can be used.
[0055] As the non-aqueous electrolyte, an electrolyte solution obtained by dissolving a solute in an organic solvent, or a so-called a polymer electrolyte layer including the electrolyte solution and immobilized by a polymer can be used. The solute of the nonaqueous electrolyte includes LiPF 6 , LiBF 4 , LiClO 4 , LiAlCl 4 , LiSbF 6 , LiSCN, LiCF 3 SO 3 , LiN(CF 3 CO 2 ), LiN(CF 3 SO 2 ) 2 , and the like. Furthermore, an example of the organic solvent may include ethylene carbonate (EC), propylene carbonate, butylene carbonate, vinylene carbonate, dimethyl carbonate (DMC), diethyl carbonate, ethyl methyl carbonate (EMC), and the like.
[0056] Furthermore, as negative current collector 11 for negative electrode 2 , a metal foil of, for example, stainless steel, nickel, copper, and titanium, and a thin film of carbon and conductive resin are used.
[0057] Furthermore, for negative electrode layer 15 of negative electrode 2 , carbon materials such as graphite, silicon (Si), tin (Sn), or the like, can be used as a negative electrode active material capable of reversibly absorbing and releasing lithium ions. Si, Sn, or the like has a theoretical capacity density of more than 833 mAh/cm 3 .
[0058] Hereinafter, a battery housing tray in accordance with the first exemplary embodiment of the present invention is described in detail with reference to FIGS. 2A and 2B .
[0059] FIG. 2A is a perspective view of a battery housing tray in accordance with the first exemplary embodiment of the present invention. FIG. 2B is a sectional view taken along line 2 B- 2 B of FIG. 2A . For easy understanding, FIG. 2B shows a state in which cylindrical batteries shown in a perspective view are housed.
[0060] As shown in FIG. 2A , battery housing tray 100 includes housing member 110 having bottom part 112 made of an insulating resin material such as polypropylene resin, and barrier rib member 120 made of an insulating resin material such as polypropylene resin and incorporated in the inner peripheral side of housing member 110 . In this case, housing member 110 and barrier rib member 120 are formed individually and separably from each other. An opening is provided opposite bottom part 112 .
[0061] As shown in FIG. 2B , housing member 110 has outer peripheral frame 115 having height T exceeding height D (a length between a positive electrode cap and a bottom surface of a battery case) of battery 130 when predetermined battery 130 is housed. Furthermore, barrier rib member 120 individually houses a plurality of predetermined batteries 130 and has height K that is at least more than 50% of the height of battery 130 . For example, when the height of a battery is 65 mm, the height of barrier rib member 120 is more than 32.5 mm.
[0062] That is to say, as shown in FIG. 2B , a plurality of batteries 130 are housed in battery housing tray 100 including barrier rib member 120 whose height exceeds 50% of the height of battery 130 and outer peripheral frame 115 whose height exceeds the height of battery 130 .
[0063] Note here that the present invention is based on the findings that when the height of barrier rib member 120 is not more than 50% of the height of battery 130 , ignition or explosion of a faulty battery may cause spread of fire to batteries in the surroundings. Furthermore, when a plurality of battery housing trays are used in a stacked state, ignition or energy of explosion of the battery is released into space formed by a barrier rib member and an outer peripheral frame thanks to the height of outer peripheral frame 115 of housing member 110 being made to be a height exceeding the height of battery. Thereby, accumulated heat is released, so that ignition or smoking in the surrounding batteries can be prevented.
[0064] At this time, it is preferable that the height of barrier rib member 120 is not less than 80% of the height of battery 130 . This is preferable because a heat insulation effect by the barrier rib member can be enhanced.
[0065] Herein, the above-mentioned exemplary embodiment describes an example in which the materials of the housing member and the barrier rib member are polypropylene resin, but the material is not necessarily limited to this example. For example, phenol resin, UNILATE, glass epoxy resin, ceramic, and foaming resin may be used. At this time, it is preferable that the above-mentioned resin contains filler such as carbon fiber and glass fiber. The filler to be contained can prevent the strength of the housing member and the barrier rib member from deteriorating and can maintain the shapes thereof under high temperatures generated at the time of heat generation or ignition of a faulty battery. That is to say, when the shapes cannot be maintained, the faulty battery tends to fall toward the surrounding batteries. Thus, it is possible to reduce the influence of ignition or heat generation on the surrounding batteries and reduce the possibility of spread of fire. Furthermore, heat absorbing agent such as magnesium hydroxide (Mg(OH) 2 ) may be added in the above-mentioned resin. Thus, by transferring heat to the battier rib member in the surroundings, it is possible to suppress temperature rise in the battier rib member around a faulty battery. Furthermore, by suppressing the temperature rise, it is possible to enhance the effect of preventing the strength from deteriorating and maintaining the shape in the barrier rib member and the like.
[0066] Alternatively, the housing member and the barrier rib member may have a configuration in which metal materials such as copper (Cu), aluminum (Al) and iron (Fe) are coated with the above-mentioned insulating resin. Thus, high heat transfer property can be achieved and the mechanical strength can be enhanced. When a short circuit due to contact with battery does not occur, the housing member and the barrier rib member may be formed of only metal materials. Furthermore, the metal material may have a mesh structure or a structure having a plurality of through holes. Thus, while the heat transfer property or mechanical strength can be maintained, the weight of the housing member and the barrier rib member can be reduced.
[0067] According to this exemplary embodiment, a flame occurring at the time of ignition or explosion of gas ejected from a vent hole of a faulty battery can be dispersed into space above the barrier rib member, thus preventing spread of fire to the surrounding batteries or abnormal overheating. Furthermore, by setting the height of the barrier rib member to a predetermined height, heating of an electrode group inside a battery case of the battery can be considerably suppressed, spread of fire, and the like, can be prevented.
[0068] Furthermore, with a structure in which the housing member and the barrier rib member are formed individually and separably from each other, only by preparing a barrier rib member corresponding to the shape of a battery, various types of batteries can be housed in the same housing member. As a result, it is possible to achieve a battery housing tray with high versatility capable of stacking batteries having different shapes in multiple stages.
[0069] The above-mentioned exemplary embodiment describes an example in which the housing member and the barrier rib member are formed individually and separably from each other, but a structure is not necessarily limited to this. For example, as shown in FIG. 3A that is a perspective view of another example of a battery housing tray in accordance with the first exemplary embodiment of the present invention and FIG. 3B that is a sectional view taken along line 3 B- 3 B of FIG. 3A , battery housing tray 150 in which housing member 160 and barrier rib member 170 are integrated with each other may be employed. Thus, the deterioration of the mechanical strength of a barrier rib member can be suppressed, and heat transfer efficiency can be enhanced by the increases in the heat releasing area. Thus, a battery housing tray with higher safety can be achieved.
Second Exemplary Embodiment
[0070] FIG. 4A is a perspective view of a battery housing tray in accordance with a second exemplary embodiment of the present invention. FIG. 4B is a sectional view taken along line 4 B- 4 B of FIG. 4A . This exemplary embodiment also describes an example in which cylindrical batteries similar to those in FIG. 1 are housed.
[0071] This exemplary embodiment has the same configuration as that in the first exemplary embodiment except that through holes are provided in a bottom part of a housing member.
[0072] Similar to the first exemplary embodiment, as shown in FIG. 4A , battery housing tray 200 includes housing member 210 having a bottom part and being made of an insulating resin material such as polypropylene resin, and barrier rib member 220 made of an insulating resin material such as polypropylene resin and incorporated in the inner peripheral side of housing member 210 . In this case, housing member 210 and barrier rib member 220 are formed individually and separably from each other.
[0073] As shown in FIG. 4B , through holes 215 smaller than the outer diameter of battery 230 are provided in bottom part 212 of housing member 210 , in a region surrounded by barrier rib member 220 .
[0074] According to this exemplary embodiment, battery housing tray 200 that houses batteries 230 is disposed in a charging and discharging tester. Thereby, the plus of a positive electrode cap of the battery and the minus on the bottom part of the battery case are connected to the tester via through hole 215 in housing member 210 so as to evaluate the battery. Thus, during a charging and discharging test, even if ignition or explosion of a faulty battery, and furthermore, explosion or ignition caused by an abnormal voltage or electric current due to a fault of the tester occur, it is possible to prevent fire from spreading to the surrounding batteries.
[0075] At this time, it is more preferable that through hole 215 is smaller than the diameter of the top portion of the positive electrode cap of battery 230 . This structure can prevent a flame and the like from directly parching a battery disposed immediately above, when a flame occurs at the time of structuring an assembled battery housing tray in which battery housing trays are stacked, and the flame is ejected in the oblique direction from the vent hole provided on the side surface of the positive electrode cap of the battery, which is described in detail in the following exemplary embodiment.
Third Exemplary Embodiment
[0076] FIG. 5A is a plan view of a battery housing tray seen from the upper part in accordance with a third exemplary embodiment of the present invention. FIG. 5B is a sectional view taken along line 5 B- 5 B of FIG. 5A . This exemplary embodiment also describes an example in which cylindrical batteries similar to those in FIG. 1 are housed.
[0077] As shown in FIG. 5A , battery housing tray 300 includes housing member 310 having a bottom part made of an insulating resin material such as polypropylene resin, and barrier rib member 320 made of an insulating resin material such as polypropylene resin, which are integrated with each other. Furthermore, rib portions 311 are formed at the inner side of housing member 310 and the inner side of barrier rib member 320 . In addition, on bottom part 312 of housing member 310 in a region surrounded by barrier rib member 320 , through holes 340 smaller than an outer diameter of battery 330 and rib portions 350 partially holding the bottom part of battery 330 are provided.
[0078] As shown in FIG. 5B , housing member 310 has outer peripheral frame 315 having height T exceeding height D (a length between a positive electrode cap and a bottom surface of a battery case) of predetermined battery 330 when battery 330 is housed. Furthermore, barrier rib member 320 individually houses a plurality of predetermined batteries 330 and has a height that is more than 50% of the height of battery 330 from a contact surface between rib portion 350 on bottom part 312 of housing member 310 and battery 330 . For example, when the height of the rib portion is 1 mm and the height of the battery is 65 mm, the height of barrier rib member 320 is more than 33.5 mm.
[0079] The configurations and materials of the above-mentioned housing member, the barrier rib member, the rib portion, and the like, are the same as those in the first exemplary embodiment and the description therefor is omitted herein.
[0080] According to this exemplary embodiment, similar to the first exemplary embodiment, a flame occurring at the time of ignition or explosion of gas ejected from a vent hole of a faulty battery can be dispersed into space above the barrier rib member, thus preventing spread of fire to the surrounding batteries and preventing abnormal overheating.
[0081] Furthermore, according to this exemplary embodiment, with the rib portions provided on the housing member and the barrier rib member, positioning of batteries to be housed can be carried out easily. Thus, the distance between the neighboring batteries can be kept uniform. Thus, the influence of heat generation or ignition of a faulty battery on the neighboring batteries can be made to be uniform. Therefore, the influence of heat generation and the like can be further suppressed as compared with the case in which rib portions are not provided.
[0082] Furthermore, according to the exemplary embodiment of the present invention, with the rib portions provided on the housing member and the barrier rib member, a circulation passage of air and the like is formed, so that a temperature around the batteries can be made to be uniform during, for example, an aging process.
[0083] The above-mentioned exemplary embodiment describes an example in which through holes are provided in the bottom part of the housing member, but through holes may not be provided when a charging and discharging test is not carried out. Furthermore, the exemplary embodiment describes an example in which rib portions are provided on the bottom part of the housing member, but these are not particularly necessary when only positioning of the battery is intended.
Fourth Exemplary Embodiment
[0084] FIG. 6 is a sectional view to illustrate an assembled battery housing tray in accordance with a fourth exemplary embodiment of the present invention. This exemplary embodiment also describes an example in which cylindrical batteries similar to those in FIG. 1 are housed.
[0085] As shown in FIG. 6 , assembled battery housing tray 400 in accordance with the fourth exemplary embodiment of the present invention has a configuration in which battery housing trays 100 A, 100 B, and 100 C described in the first exemplary embodiment are stacked in, for example, three stages. Since the configurations of battery housing trays 100 A, 100 B, and 100 C are the same as the configuration of the battery housing tray in the first exemplary embodiment, the description thereof is omitted.
[0086] That is to say, as shown in FIG. 6 , a plurality of battery housing trays 100 A, 100 B, and 100 C are stacked via outer peripheral frames 115 A, 115 B, and 115 C of each battery housing tray.
[0087] Thus, space 402 is formed between, for example, bottom part 112 B of battery housing tray 100 B and outer peripheral frame 115 C of battery housing tray 100 C. As a result, energy generated when ignition or explosion of a faulty battery occurs can be dispersed to space 402 . Thus, abnormal overheating or concentration of a flame on the surrounding batteries can be reduced, and an induced explosion or spread of fire can be prevented. The same is true to the relation between battery housing tray 100 B and battery housing tray 100 A. In addition, in battery housing tray 100 A, since the upper part of battery 130 is opened, the influence on the surrounding batteries can be further reduced.
[0088] According to this exemplary embodiment, it is possible to achieve an assembled battery housing tray with high safety and high reliability in which the influence of heat generation or ignition of a faulty battery can be prevented even when a plurality of battery housing trays are stacked.
[0089] In the above mention, an example in which the battery housing trays of the first exemplary embodiment are stacked is described. However, the configuration is not necessarily limited to this example, and the battery housing trays of the second or third exemplary embodiment may be stacked. In this case, the same effect can be also obtained.
[0090] Hereinafter, another example of an assembled battery housing tray in accordance with the fourth exemplary embodiment is described with reference to FIGS. 7A and 7B .
[0091] FIGS. 7A and 7B are sectional views to illustrate another example of an assembled battery housing tray in accordance with the fourth exemplary embodiment of the present invention. FIG. 7A is a sectional view showing a state before battery housing trays are stacked, and FIG. 7B is a sectional view showing a state after battery housing trays are stacked.
[0092] That is to say, as shown in FIG. 7A , battery housing tray 500 includes first concave portion 517 at the end surface of outer peripheral frame 515 of housing member 510 , and second convex portion 516 to be fitted with first concave portion 517 is provided on the outer surface of bottom part 512 . Then, for example, by allowing first concave portion 517 of battery housing tray 500 on the lower stage to be fitted with second convex portion 516 of battery housing tray 500 on the upper stage, assembled battery housing tray 600 is formed.
[0093] Thus, it is possible to achieve an assembled battery housing tray that prevents displacement in the battery housing trays to be stacked and improves stability at the time of stacking.
[0094] In the above mention, an example in which a first concave portion is provided on the outer peripheral frame and a second convex portion is provided on the bottom part in the housing member is described. However, the configuration is not necessarily limited to this example. For example, a configuration in which a first convex portion is provided on the outer peripheral frame and a second concave portion is provided on the bottom part in the housing member may be employed. In this case, the same effect can be obtained.
[0095] In the above mention, an example in which a second convex portion is provided on the battery housing tray on the bottom stage is described, but it may not be particularly provided.
[0096] Furthermore, the above-mentioned exemplary embodiment describes a configuration in which an upper part of the battery housing tray on the top stage is opened, but the configuration is not necessarily limited to this example. For example, a lid is formed from the housing member from which the outer peripheral frame is removed and which includes bottom part and a second convex portion, and the battery housing tray on the top stage is lidded by the above-mentioned lid. Such a configuration may be acceptable. Thus, even if ignition or explosion occurs in a faulty battery on the battery housing tray on the top stage, scattering thereof can be securely prevented by the lid.
Fifth Exemplary Embodiment
[0097] FIG. 8A is a transparent plan view of an assembled battery housing tray seen from the upper part in accordance with a fifth exemplary embodiment of the present invention. FIG. 8B is a sectional view taken along line 8 B- 8 B of FIG. 8A . For easy understanding, FIG. 8B shows a state in which cylindrical batteries shown in a perspective view are housed.
[0098] As shown in FIG. 8B , this exemplary embodiment is different from the fourth exemplary embodiment in that batteries in a battery housing tray of the lower stage and batteries in a battery housing tray of the upper stage are shifted from each other in the stacked direction so that they are not immediately (directly) overlapped to each other. Hereinafter, an example in which the battery housing trays are stacked in two stages is described, but the configuration is not necessarily limited to this example.
[0099] That is to say, as shown in FIG. 8B , on the upper part of first battery housing tray 700 provided with barrier rib member 720 , second battery housing tray 800 provided with barrier rib member 820 is stacked, thus forming assembled battery housing tray 900 . At this time, as shown in FIG. 8A , battery housing region 722 surrounded by barrier rib member 720 (broken line in the drawing) and battery housing region 822 surrounded by barrier rib member 820 are disposed such that they are shifted from each other.
[0100] According to this exemplary embodiment, at the time of stacking, a battery to be stacked is not disposed immediately above another battery. Therefore, the length between the stacked batteries can be increased, and the influence of ignition or explosion caused by a gas ejected from a faulty battery can be further reduced.
[0101] Note here that, as shown in FIG. 8A , this exemplary embodiment describes an example in which battery housing region 822 defined by barrier rib member 820 of second battery housing tray 800 is disposed so as to span four battery housing regions 722 defined by barrier rib member 720 of first battery housing tray 700 . However, the configuration is not necessarily limited to this example. For example, battery housing region 822 defined by barrier rib member 820 of second battery housing tray 800 may be disposed so as to span two battery housing regions 722 defined by barrier rib member 720 of first battery housing tray 700 . Any disposition is possible as long as one battery housing region 722 of barrier rib member 720 of first battery housing tray 700 is not overlapped to one battery housing region 822 of barrier rib member 820 of second battery housing tray 800 on one-to-one.
[0102] Hereinafter, the first to fifth exemplary embodiments of the present invention are specifically described with reference to examples. Note here that the present invention is not necessarily limited to the following the examples, and modifications can be made by changing materials to be used and the like within the scopes of the summary of the present invention.
Example 1
[0103] Firstly, cylindrical batteries each having a height of 65 mm, an outer diameter of 18 mm, and a battery capacity of 2600 mAh are used. A three-row and three-column battery housing tray including a barrier rib member with a height of 32.6 mm (a height of more than 50% of the height of the battery) and an outer peripheral frame with a height of 67 mm is prepared. Nine batteries described above are housed in the battery housing tray. This is designated as sample 1.
Example 2
[0104] Example 2 is carried out the same as Example 1 except that the height of the barrier rib member is 39 mm (a height of 60% of the height of the battery). This is designated as sample 2.
Example 3
[0105] Example 3 is carried out the same as Example 1 except that the height of the barrier rib member is 52 mm (a height of 80% of the height of the battery). This is designated as sample 3.
Example 4
[0106] Example 4 is carried out the same as Example 1 except that the height of the barrier rib member is 65 mm (a height of 100% of the height of the battery). This is designated as sample 4.
Comparative Example 1
[0107] Comparative Example 1 is carried out the same as Example 1 except that the height of the barrier rib member is 26 mm (a height of 40% of the height of the battery). This is designated as sample C1.
[0108] The battery housing trays produced as mentioned above are evaluated as follows while housing a plurality of batteries.
[0109] Firstly, a battery from which safety mechanisms other than a vent mechanism are removed is produced. Nine of such batteries are housed and disposed in a three-row and three-column battery housing tray. Next, assuming that trouble in charging equipment occurs in only a battery in the center part, charging is carried out until the voltage of the battery in the center part becomes 5V to make it to eject gas. The gas is ignited to produce a flame.
[0110] At this time, thermocouples are respectively attached to the surrounding batteries at the opposite side of the surface facing the battery in the center part, and the increased temperature is measured. Furthermore, after the test is finished, each battery is decomposed, and a short-circuit state in an electrode group is observed. Furthermore, an opening state of the vent mechanism provided in each battery is observed.
[0111] Then, the influence of ignition of the battery in the center part on the surrounding batteries is evaluated with respect to the maximum increased temperature, the number of short-circuited batteries, the number of batteries whose vent mechanism is opened, and presence or absence of ignition or explosion.
[0112] Hereinafter, parameters and evaluation results of samples 1 to 4 and sample C1 are shown in Table 1.
[0000]
TABLE 1
Parameters
Evaluation results
Height of
Maximum increased
Number of short-
outer
Height of
Ratio of barrier
temperature of
circuited
Number of batteries
Ignition/explosion
peripheral
barrier
rib height to
surrounding
batteries
whose vent mechanism
of surrounding
frame (mm)
rib (mm)
battery height (%)
batteries (° C.)
(battery)
is opened (battery)
batteries
Sample 1
67
32.6
>50
130
2
0
N
Sample 2
67
39
60
110
1
0
N
Sample 3
67
52
80
90
0
0
N
Sample 4
67
65
100
80
0
0
N
Sample C1
67
26
40
360
8
5
P
N: not present, P: present
[0113] As shown in Table 1, comparison among samples 1 to 4 and sample C1 is carried out. In battery housing trays partitioned by barrier rib member whose height is more than 50% of the height of the battery, opening of a vent mechanism, which may cause ignition or explosion in the surrounding batteries, is not observed. However, as sample C1, in a battery housing tray having a barrier rib member whose height is about 40% of the height of the battery, opening of a vent mechanism, which may cause an induced explosion or ignition in the surrounding batteries by ignition or explosion of the battery in the center part, is observed in five batteries out of eight batteries. In some batteries, ignition or explosion occurs. This is thought to be because by providing a barrier rib member having a predetermined height, opening of a vent mechanism, which may cause an induced explosion or ignition in the surrounding batteries, does not occur, and therefore ejection of an electrolytic solution can be efficiently prevented.
[0114] Furthermore, as shown in Table 1, comparison among sample 1, sample 2 and sample C1 is carried out. In the surrounding batteries, a battery with a short circuit is observed because a separator contracts due to temperature rise in an electrode group in the battery. In particular, in sample C1, all of the surrounding batteries are short-circuited. On the other hand, in the batteries of samples 1 and 2, a short circuit in an electrode group occurs in a part of the surrounding batteries. This is thought to be because opening of the vent mechanism does not occur but a heat insulation effect of suppressing heat of ignited battery is not sufficient in a barrier rib member having a height of about 60% of the battery height.
[0115] Furthermore, as shown in Table 1, in samples 3 and 4, even if ignition or explosion occurs in a battery in the center part, temperature rise is small and a short circuit in an electrode group or opening of a vent mechanism is not observed. That is to say, it is shown that when the height of the barrier rib member is made to be 80% or more of the battery height, even a fault occurs in some batteries, the influence of the fault on the surrounding batteries can be considerably suppressed.
Sixth Exemplary Embodiment
[0116] Hereinafter, a battery housing tray in accordance with a sixth exemplary embodiment of the present invention is described with reference to FIGS. 9A and 9B . This exemplary embodiment also describes an example in which cylindrical batteries that are the same as in FIG. 1 are housed.
[0117] FIG. 9A is a perspective view of a battery housing tray in accordance with a sixth exemplary embodiment of the present invention. FIG. 9B is a sectional view taken along line 9 B- 9 B of FIG. 9A . For easy understanding, FIG. 9B shows a state in which cylindrical batteries shown in a perspective view are housed.
[0118] This exemplary embodiment is different from the first exemplary embodiment in the following points. A housing member includes a barrier rib member on an inner surface of a bottom part of the housing member, which is defined as a first barrier rib member, and further includes a second barrier rib member on an outer surface of the bottom part of the housing member in a position corresponding to the first barrier rib member. An air hole is provided in the second barrier rib member in a direction along the outer surface of the housing member. The sum of the height of the first barrier rib member and the height of the second barrier rib member is not less than the height of the battery. Other configurations are the same as those in the first exemplary embodiment.
[0119] As shown in FIG. 9A , battery housing tray 1000 has a configuration in which first barrier rib member 1120 and second barrier rib member 1122 are integrated with housing member 1110 . First barrier rib member 1120 is made of an insulating resin material such as polypropylene resin and is provided on inner surface 1114 of the bottom part of housing member 1110 ; and second barrier rib member 1122 is made of an insulating resin material such as polypropylene resin and is provided on outer surface 1116 of the bottom part of housing member 1110 .
[0120] Furthermore, as shown in FIG. 9B , second barrier rib member 1122 has air hole 1125 in a direction along outer surface 1116 of housing member 1110 . Air hole 1125 has a function of exhausting a flame produced by ignition of gas accompanying ejected gas or explosion by an opening of a vent mechanism of a faulty battery when a plurality of battery housing trays are stacked, which is described in detail in the below-mentioned exemplary embodiment. First barrier rib member 1120 and second barrier rib member 1122 are provided facing each other with housing member 1110 sandwiched therebetween. Furthermore, a sum of height K 1 of first barrier rib member 1120 and height K 2 of second barrier rib member 1122 is not less than height D (a length between a positive electrode cap and a bottom surface of a battery case) of battery 1130 to be housed. At this time, when battery housing tray 1000 is used singly, it is preferable that height K 1 of first barrier rib member 1120 is more than 50% of the height of battery 1130 . For example, when the height of battery 1130 is 65 mm, the height of first barrier rib member 1120 is more than 32.5 mm.
[0121] As shown in FIG. 9B , this exemplary embodiment describes an example in which outer peripheral frame 1115 whose height is higher than height K 1 of first barrier rib member 1120 is provided on the outer periphery of inner surface 1114 of the bottom part of housing member 1110 . However, the configuration is not necessarily limited to this example. For example, height T of outer peripheral frame 1115 may be the same as height K of first barrier rib member 1120 . In this case, it is preferable that an outer peripheral frame (not shown) whose height is the same as height K 2 of second barrier rib member 1122 is provided on the outer periphery of outer surface 1116 of the bottom part of housing member 1110 .
[0122] With the above-mentioned configuration, as shown in FIG. 9B , when a battery housing tray is used singly, a plurality of batteries 1130 are housed in battery housing tray 1000 formed of first barrier rib member 1120 whose height is more than 50% of the height of each battery 1130 and outer peripheral frame 1115 whose height exceeds the height of each battery 1130 .
[0123] Note here that the present invention is based on the findings that when the height of first barrier rib member 1120 is not more than 50% of the height of battery 1130 , due to ignition or explosion of a faulty battery, fire spreads to the batteries in the surroundings. Furthermore, with a configuration in which the height of outer peripheral frame 1115 of housing member 1110 is made to exceed the height of the battery, when a plurality of battery housing trays are stacked, energy of ignition or explosion of the battery is released to space formed by bringing first barrier rib member 1120 into contact with second barrier rib member 1122 , it is possible to disperse the accumulated heat via air hole 1125 and to prevent the ignition or smoking of the surrounding batteries.
[0124] Furthermore, when a battery housing tray is used singly, in particular, it is preferable that height K 1 of first barrier rib member 1120 is not less than 80% of height D of battery 1130 . This is preferable because that a heat insulation effect by the barrier rib member can be increased.
[0125] Herein, the above-mentioned exemplary embodiment describes an example in which the materials of the housing member, the first barrier rib member and the second barrier rib member are polypropylene resin, but the material is not necessarily limited to this example. For example, phenol resin, UNILATE, glass epoxy resin, ceramic, and foaming resin may be used. At this time, it is preferable that the above-mentioned resin contains filler such as carbon fiber and glass fiber. The filler to be contained can prevent the strength of the housing member and the first and second barrier rib members from deteriorating and can maintain the shapes thereof at high temperatures at the time of heat generation or ignition of a faulty battery. Otherwise, when the shapes cannot be maintained, the faulty battery tends to fall toward the surrounding batteries. Thus, it is possible to reduce the influence of ignition and heat generation on the surrounding batteries and reduce the possibility of spread of fire. Furthermore, heat absorbing agent such as magnesium hydroxide (Mg(OH) 2 ) may be added in the above-mentioned resin. Thus, by transferring heat to the first and second barrier rib members in the surroundings, it is possible to suppress temperature rise in the battier rib member(s) around a faulty battery. Furthermore, by suppressing the temperature rise, it is possible to enhance the effect of preventing the strength of the first and second barrier rib members and the like from deteriorating and maintaining the shape.
[0126] Furthermore, the housing member and the first and second barrier rib members may have a configuration in which metal materials such as copper (Cu), aluminum (Al) and iron (Fe) are coated with the above-mentioned insulating resin. Thus, high heat transfer property can be achieved and the mechanical strength can be enhanced. When a short circuit due to contact with battery does not occur, the housing member and the barrier rib members may be formed of only metal materials. Furthermore, the metal material may have a mesh structure or a structure having a plurality of through holes. Thus, while the heat transfer property or mechanical strength can be maintained, the weight of the housing member and the first and second barrier rib members can be reduced.
[0127] According to this exemplary embodiment, a flame occurring at the time of ignition or explosion of gas ejected from a vent hole of a faulty battery can be dispersed into space above the first barrier rib member, thus preventing spread of fire to the surrounding batteries or abnormal overheating. Furthermore, by setting the height of the first barrier rib member to a predetermined height, heating of an electrode group inside a battery case of the battery can be considerably suppressed, spread of fire, and the like, can be prevented.
[0128] Note here that the above-mentioned exemplary embodiment describes an example of a structure in which the housing member, and the first and second barrier rib members are integrated with each other, but the structure is not particularly limited to this example. For example, as shown in FIG. 10A that is a perspective view showing another example of a battery housing tray in accordance with the sixth exemplary embodiment of the present invention and FIG. 10B that is a sectional view taken along line 10 B- 10 B of FIG. 10A , battery housing tray 1150 may have a configuration in which housing member 1160 and at least first barrier rib member 1170 and second barrier rib member 1172 can be separated from each other. Thus, by only preparing the first barrier rib member and the second barrier rib member corresponding to the shapes of batteries, various types of batteries can be housed in the same housing member. As a result, it is possible to achieve a battery housing tray with high versatility, which is capable of stacking batteries having different shapes in multiple stages.
Seventh Exemplary Embodiment
[0129] FIG. 11A is a perspective view showing a battery housing tray in accordance with a seventh exemplary embodiment of the present invention. FIG. 11B is a sectional view taken along line 11 B- 11 B of FIG. 11A . This exemplary embodiment also describes an example in which cylindrical batteries that are the same as those in FIG. 1 are housed.
[0130] This exemplary embodiment is different from the sixth exemplary embodiment in that a through hole penetrating from an inner surface to an outer surface of a bottom part of a housing member is provided. Note here that other configurations are the same as those in the sixth exemplary embodiment.
[0131] As shown in FIG. 11A , similar to the sixth exemplary embodiment, battery housing tray 1200 includes first barrier rib member 1220 provided on inner surface 1214 of the bottom part of housing member 1210 and made of an insulating resin material such as polypropylene resin, and second barrier rib member 1222 made of an insulating resin material such as polypropylene resin and provided on outer surface 1216 of the bottom part of housing member 1210 , which are integrated into housing member 1210 .
[0132] Furthermore, as shown in FIG. 11B , second barrier rib member 1222 includes air holes 1225 in a direction along outer surface 1216 of the bottom part of housing member 1210 . First barrier rib member 1220 and second barrier rib member 1222 are provided facing each other on the same position with the bottom part of housing member 1210 sandwiched therebetween. Furthermore, a sum of height K 1 of first barrier rib member 1220 and K 2 of second barrier rib member 1222 is not less than height D (a length between a positive electrode cap and a bottom surface of a battery case) of batteries 1230 to be housed.
[0133] As shown in FIG. 11B , in housing member 1210 , in a battery housing region surrounded by first barrier rib member 1220 and second barrier rib member 1222 , through hole 1215 which is smaller than the outer diameter of battery 1230 and which penetrates from inner surface 1214 to outer surface 1216 of the bottom part of housing member 1210 are provided.
[0134] According to this exemplary embodiment, battery housing tray 1200 in a state of housing batteries 1230 is disposed on a charging and discharging tester, in which the plus of a positive electrode cap of the battery and the minus on the bottom part of the battery case are connected to the tester via through hole 1215 in housing member 1210 . Thus, the battery can be evaluated. During a charging and discharging test, even if ignition or explosion of a faulty battery, furthermore, explosion or ignition caused by an abnormal voltage or an electric current due to a fault of the tester may occur, it is possible to prevent the fire from spreading to the surrounding batteries by first barrier rib member 1220 similar to the sixth exemplary embodiment.
[0135] At this time, it is further preferable that through hole 1215 is smaller than the diameter of the top portion of the positive electrode cap of battery 1230 . This is preferable because a flame and the like can be prevented from directly parching a battery disposed immediately (directly) above when a flame occurs at the time of structuring an assembled battery housing tray in which battery housing trays are stacked, and the flame is ejected in the oblique direction from the vent hole provided on the side surface of the positive electrode cap of the battery, which is described in detail in the following exemplary embodiment.
Eighth Exemplary Embodiment
[0136] FIG. 12A is a plan view of a battery housing tray seen from the upper part in accordance with an eighth exemplary embodiment of the present invention. FIG. 12B is a sectional view taken along line 12 B- 12 B of FIG. 12A . This exemplary embodiment also describes an example in which cylindrical batteries that are the same as those in FIG. 1 are housed.
[0137] As shown in FIG. 12A , battery housing tray 1300 includes first barrier rib member 1320 provided on inner surface 1314 of the bottom part of housing member 1310 and made of an insulating resin material such as polypropylene resin, and second barrier rib member 1322 made of an insulating resin material such as polypropylene resin and provided on outer surface 1316 of the bottom part of housing member 1310 , which are integrated with housing member 1310 . Furthermore, rib portions 1311 are provided in the inner side of housing member 1310 and the inner side of at least first barrier rib member 1320 . Furthermore, in housing member 1310 , in a region surrounded by first barrier rib member 1320 and second barrier rib member 1322 , through hole 1340 smaller than the outer diameter of battery 1330 and rib portion 1350 partially holding the bottom part of battery 1330 is provided on the inner surface 1314 of a bottom part of housing member 1310 .
[0138] As shown in FIG. 12B , when predetermined battery 1330 is housed, housing member 1310 has outer peripheral frame 1315 having height T exceeding height D (a length between a positive electrode cap and a bottom surface of a battery case) of the battery. Furthermore, first barrier rib member 1320 individually houses a plurality of predetermined batteries 1330 and has a height that is more than 50% of the height of battery 1330 from a contact surface between rib portion 1350 on inner surface 1314 of the bottom part of housing member 1310 and battery 1330 . For example, when the height of a rib portion is 1 mm and the height of a battery is 65 mm, the height of first barrier rib member 1320 is more than 33.5 mm.
[0139] The configurations and materials of the above-mentioned housing members, the first and second barrier rib members, the rib portions, and the like, are the same as those in the sixth exemplary embodiment, and the description therefor is omitted herein.
[0140] According to this exemplary embodiment, similar to the sixth exemplary embodiment, a flame occurring at the time of ignition or explosion of gas ejected from a vent hole of a faulty battery can be dispersed into space above the first barrier rib member, thus preventing spread of fire to the surrounding batteries or preventing abnormal overheating.
[0141] Furthermore, according to this exemplary embodiment, with the rib portions provided on the housing member and the first barrier rib member, positioning of batteries to be housed can be carried out easily. Furthermore, the distance between the neighboring batteries can be kept uniform. Thus, the influence of heat generation or ignition of a faulty battery on the neighboring batteries can be made to be uniform. Therefore, the influence of heat generation and the like can be further suppressed as compared with the case in which rib portions are not provided.
[0142] Furthermore, according to the exemplary embodiment of the present invention, with the rib portions provided on the housing member and the first barrier rib member, a circulation passage of air and the like is formed, so that a temperature around the batteries can be made to be uniform during, for example, an aging process.
[0143] The above-mentioned exemplary embodiment describes an example in which through holes are provided in the bottom part of the housing member, but through holes may not be provided when a charging and discharging test is not carried out. Furthermore, the exemplary embodiment describes an example in which rib portions are provided on the inner surface of the bottom part of the housing member, but they are not particularly necessary when only positioning of the battery is intended.
Ninth Exemplary Embodiment
[0144] FIGS. 13A and 13B are sectional views to illustrate an assembled battery housing tray in accordance with a ninth exemplary embodiment of the present invention. FIG. 13A shows a state before battery housing trays are stacked, and FIG. 13B shows a state after battery housing trays are stacked. This exemplary embodiment also describes an example in which cylindrical batteries that are the same as those in FIG. 1 are housed.
[0145] As shown in FIGS. 13A and 13B , assembled battery housing tray 1400 in accordance with the ninth exemplary embodiment of the present invention has a configuration in which battery housing trays 1000 A and 1000 B described in the sixth exemplary embodiment are stacked in, for example, two stages. Since the configurations of battery housing trays 1000 A and 1000 B are the same as those of the battery housing tray in the sixth exemplary embodiment, the description therefor is omitted.
[0146] That is to say, as shown in FIG. 13B , first barrier rib member 1120 A of battery housing tray 1000 A and second barrier rib member 1122 B of battery housing tray 1000 B are brought into contact with each other and stacked. At this time, for example, first barrier rib member 1120 A of battery housing tray 1000 A and second barrier rib member 1122 B of battery housing tray 1000 B are brought into contact with each other, so that space 1402 is formed. Then, space 1402 is shared by the entire assembled battery housing tray via air hole 1125 B of second barrier rib member 1122 B. This is because a sum of the height of first barrier rib member 1120 A and the height second barrier rib member 1122 B is higher than the height of battery 1130 to be housed.
[0147] Note here that FIG. 13B shows that outer peripheral frame 1115 A of battery housing tray 1000 A and outer surface 1116 B of the bottom part of housing member 1110 B of battery housing tray 1000 B are similarly brought into contact with each other, but they are not necessarily brought into contact with each other and a gap may be formed therebetween.
[0148] Consequently, by dispersing energy generated by ignition or explosion of a faulty battery to space 1402 shared via air hole 1125 B, abnormal overheating or concentration of a flame on the surrounding batteries can be reduced and thus an induced explosion or spread of fire can be prevented. In battery housing tray 1000 B, an influence on the surrounding battery can be reduced because an upper part of battery 1130 is opened.
[0149] According to this exemplary embodiment, it is possible to achieve an assembled battery housing tray with safety and high reliability in which the influence of heat generation or ignition of a faulty battery can be prevented even when a plurality of battery housing trays are stacked.
[0150] In the above mention, a configuration in which the battery housing trays of the sixth exemplary embodiment are stacked is described, but the configuration is not necessarily limited to this example. The battery housing trays of the seventh or eighth exemplary embodiment may be stacked. In such cases, the same effect can be obtained.
[0151] Hereinafter, another example 1 of the assembled battery housing tray in accordance with the ninth exemplary embodiment of the present invention is described with reference to FIGS. 14A and 14B .
[0152] FIGS. 14A and 14B are sectional views to illustrate another example 1 of an assembled battery housing tray in accordance with the ninth exemplary embodiment of the present invention. FIG. 14A is a sectional view showing a state before battery housing trays are stacked, and FIG. 14B is a sectional view showing a state after battery housing trays are stacked.
[0153] That is to say, as shown in FIG. 14A , battery housing tray 1500 includes first concave portion 1517 at the end surface of outer peripheral frame 1515 of housing member 1510 , and second convex portion 1518 to be fitted with first concave portion 1517 is provided on outer surface 1516 of the bottom part of barrier rib member 1510 . Then, for example, first concave portion 1517 of battery housing tray 1500 on the lower stage is allowed to be fitted with second convex portion 1518 of battery housing tray 1500 on the upper stage, and first barrier rib member 1120 on the lower stage and second barrier rib member 1122 on the upper stage are brought into contact with each other. Thus, assembled battery housing tray 1600 is formed.
[0154] Thus, it is possible to achieve an assembled battery housing tray capable of preventing battery housing trays to be stacked from being displaced and of improving stability at the time of stacking.
[0155] In the above mention, an example in which a first concave portion is provided on an outer peripheral frame of a housing member and a second convex portion is provided on the bottom part side. However, the configuration is not necessarily limited to this example. For example, a configuration in which the first convex portion is provided on the outer peripheral frame of the housing member and the second concave portion is provided on the bottom part may be employed. With such a configuration, the same effect can be obtained.
[0156] The above-mentioned exemplary embodiment describes an example in which a second convex portion and a second barrier rib member are provided on battery housing tray on the bottom stage. However, as shown in another example 2 of the assembled battery housing tray in FIG. 15 , as battery housing tray 1625 , the second convex portion and a second barrier rib member on the bottom stage may be removed. Furthermore, the above-mentioned exemplary embodiment describes a state in which an upper part of the battery housing tray on the top stage is opened, but the configuration is not necessarily limited to this example. For example, as shown in FIG. 15 , a configuration in which lid 1650 is formed of the housing member from which an outer peripheral frame and a first barrier rib member are removed and which includes a second barrier rib member, and the battery housing tray on the top stage is be lidded by lid 1650 may be employed. Thus, even if ignition or explosion occurs in a faulty battery in the battery housing tray on the top stage, scattering thereof can be securely prevented by lid 1650 .
[0157] Furthermore, the above-mentioned exemplary embodiment describes an example in which a first concave portion is provided on the outer peripheral frame of the housing member is provided, and a second convex portion is provided on the outer surface of the bottom part of the housing member. However, the configuration is not necessarily limited to this example. For example, as shown in another example 1 of FIG. 16A , first concave portion 1721 is provided on first barrier rib member 1720 and second convex portion 1723 is provided on second barrier rib member 1722 , and they may be fitted with each other to be stacked. Furthermore, as shown in another example 2 of FIG. 16B , for example, conical or pyramid-shaped first convex portion 1724 is provided on an end portion of first barrier rib member 1720 , and conical or pyramid-shaped second concave portion 1725 to be fitted with first convex portion 1724 is provided on the end portion of second barrier rib member 1722 , and they may be fitted with each other to be stacked.
[0158] Similar to the above, these configurations make it easy to stack battery housing trays and to securely prevent side slip and the like. Furthermore, it is possible to improve the airtightness of space formed by the first barrier rib member and the second barrier rib member, and to effectively prevent a flame from diffusing between the contact surfaces of the first barrier rib member and the second barrier rib member.
Tenth Exemplary Embodiment
[0159] FIG. 17A is a transparent plan view of an assembled battery housing tray seen from the upper part in accordance with a tenth exemplary embodiment of the present invention. FIG. 17B is a sectional view taken along line 17 B- 17 B of FIG. 17A . For easy understanding, FIG. 17B shows a state in which cylindrical batteries shown in a perspective view are housed.
[0160] As shown in FIG. 17B , this exemplary embodiment is different from the ninth exemplary embodiment in that batteries in a battery housing tray on the lower stage and batteries in a battery housing tray on the upper stage are shifted from each other in the stacked direction so that they are not immediately (directly) overlapped to each other. Hereinafter, an example in which the battery housing trays stacked in two stages is described, but the configuration is not necessarily limited to this example.
[0161] That is to say, as shown in FIG. 17B , on first battery housing tray 1800 provided with at least first barrier rib member 1820 , second battery housing tray 1900 provided with first barrier rib member 1920 and second barrier rib member 1922 is stacked, thus forming assembled battery housing tray 2000 . At this time, as shown in FIG. 17A , battery housing region 2002 surrounded by first barrier rib member 1820 of first battery housing tray 1800 and second barrier rib member 1922 of second battery housing tray 1900 (broken line in the drawing) and battery housing region 2004 surrounded by barrier rib member 1920 of first battery housing tray 1800 are disposed such that they are shifted from each other.
[0162] According to this exemplary embodiment, at the time of stacking one battery to be stacked is not disposed immediately above another battery. Therefore, the distance between the stacked batteries is increased, and the influence of ignition or explosion caused by a faulty battery can be further reduced.
[0163] In this exemplary embodiment, battery housing region 2004 surrounded by first barrier rib member 1920 of second battery housing tray 1900 is disposed so as to span four battery housing regions 2002 of first barrier rib member 1820 of first housing tray 1800 . However, the configuration is not necessarily limited to this example. For example, battery housing region 2004 of first barrier rib member 1920 of second battery housing tray 1900 may be disposed so as to span two battery housing regions 2002 of first barrier rib member 1820 of first battery housing tray 1800 . Any disposition is possible as long as battery housing region 2002 of first battery housing tray 1800 and battery housing region 2004 of second battery housing tray 1900 are not overlapped to each other (do not coincide with each other).
[0164] Note here that the shapes of the air hole of the second barrier rib member described in the assembled battery housing tray in the above-mentioned eighth or ninth exemplary embodiment include any shapes such as circular-shaped air hole 2010 or rectangular-shaped air hole 2020 as shown in FIGS. 18A and 18B . At this time, it is preferable that the air hole is disposed in the vicinity of a vent hole of the housed battery.
[0165] Furthermore, when the height of first barrier rib member 2120 of battery housing tray 2100 on the lower stage of the assembled battery housing tray is not less than 80% of the height of the battery, as shown in FIG. 18C , for example, a semicircular air hole may be formed on end portion of the contact surface 2250 side between barrier rib member 2120 of battery housing tray 2100 and second barrier rib member 2222 of battery housing tray 2200 .
[0166] Hereinafter, the sixth to tenth exemplary embodiments of the present invention are specifically described with reference to examples. Note here that the present invention is not necessarily limited to the following examples, and modifications can be made by changing materials to be used and the like within the scopes of the present invention.
Example 5
[0167] Firstly, cylindrical batteries each having a height of 65 mm, an outer diameter of 18 mm, and a battery capacity of 2600 mAh are used. A three-row and three-column battery housing tray including a first barrier rib member having a height of 32.6 mm (a height exceeding 50% of a height of the battery) and a second barrier rib member provided with an air hole and having a height of 34.4 mm is produced. The thus obtained battery housing trays are stacked to form an assembled battery housing tray, and nine batteries described above are housed in a three-row and three-column battery housing tray on at least the lower stage. This is designated as sample 5.
Example 6
[0168] Example 6 is carried out the same as Example 5 except that the height of the first barrier rib member is 39 mm (a height of 60% of the height of the battery) and the height of the second barrier rib member is 28 mm. This is designated as sample 6.
Example 7
[0169] Example 7 is carried out the same as Example 5 except that the height of the first barrier rib member is 52 mm (a height of 80% of the height of the battery) and the second barrier rib member is 15 mm. This is designated as sample 7.
Example 8
[0170] Example 8 is carried out the same as Example 5 except that the height of the barrier rib member is 65 mm (a height of 100% of the height of the battery), the height of the second barrier rib member is 2 mm, and air holes are provided in the vicinity of shorter side of the first barrier rib (at height of 55 mm). This is designated as sample 8.
Example 9
[0171] Example 9 is carried out the same as Example 5 except that the height of the first barrier rib member is 26 mm (a height of 40% of the height of the battery), the height of the second barrier rib member is 36 mm, and the battery housing trays are stacked via the outer peripheral frame with a height of 67 mm, and a gap (5 mm) is provided between the first barrier rib member and the second barrier rib member. This is designated as sample 9.
Example 10
[0172] Example 10 is carried out the same as Example 5 except that the height of the barrier rib member is 32.6 mm (a height of more than 50% of the height of the battery) and the height of the second barrier rib member is 0 mm. This is designated as sample 10.
Example 11
[0173] Example 11 is carried out the same as Example 5 except that the height of the barrier rib member is 52 mm (a height of 80% of the height of the battery) and the height of the second barrier rib member is 0 mm. This is designated as sample 11.
Comparative Example 2
[0174] Comparative Example 2 is carried out the same as Example 5 except that the height of the first barrier rib member is 26 mm (a height of 40% of the height of the battery), the height of the second barrier rib member is 0 mm, and the battery housing trays are stacked via the outer peripheral frame with a height of 67 mm, and a gap (41 mm) is provided between the first barrier rib member and the second barrier rib member. This is designated as sample C2.
[0175] The battery housing trays produced as mentioned above while housing a plurality of batteries are evaluated as follows.
[0176] Firstly, a battery from which safety mechanisms other than a vent mechanism are removed is produced. Nine of such batteries are housed and disposed in a three-row and three-column battery housing tray. Next, assuming that trouble in charging equipment occurs in only a battery in the center part, the battery in the center part is charged until the battery voltage becomes 5V to eject gas. The gas is ignited to produce a flame.
[0177] At this time, thermocouples are respectively attached to the surrounding batteries at the opposite side of the surface facing the battery in the center part, and the increased temperature is measured. Furthermore, after the test is finished, each battery is decomposed, and a short-circuit state of an electrode group is observed. Furthermore, an opening state of the vent mechanism provided in each battery is observed.
[0178] Then, the influence of ignition of the battery in the center part on the surrounding batteries is evaluated with respect to the maximum increased temperature, the number of short-circuited batteries, the number of batteries whose vent mechanism is opened, and presence or absence of ignition or explosion.
[0179] Hereinafter, parameters and evaluation results of samples 5 to 11 and sample C2 are shown in Table 2.
[0000]
TABLE 2
Parameters
Evaluation results
Height of
Height of
Ratio of first
Maximum increased
Number of short-
first
second
barrier rib
temperature of
circuited
Number of batteries
Ignition/explosion
barrier
barrier
height to battery
surrounding
batteries
whose vent mechanism
of surrounding
rib (mm)
rib (mm)
height (%)
batteries (° C.)
(battery)
is opened (battery)
batteries
Sample 5
32.6
33.4
>50
70
0
0
N
Sample 6
39
28
60
70
0
0
N
Sample 7
52
15
80
70
0
0
N
Sample 8
65
2
100
70
0
0
N
Sample 9
26
36
40
80
0
0
N
Sample 10
32.6
0
>50
130
2
0
N
Sample 11
52
0
80
90
0
0
N
Sample C2
26
0
40
360
8
5
P
N: not present, P: present
[0180] As shown in Table 2, in samples 5 to 9, temperature rise, a short circuit in an electrode group, and opening of a vent mechanism do not occur in the surrounding batteries. This is thought to be because battery housing trays are stacked and batteries are housed in space surrounded by the first barrier rib member and the second barrier rib member, so that the influence of a fault can be considerably suppressed in each barrier rib member even if a fault occurs in a part of batteries.
[0181] Furthermore, as shown in Table 2, when comparison among sample 10, sample 11 and sample C2 is carried out, in the battery housing tray partitioned by the first barrier rib member whose height is more than 50% of the height of the battery, even in a case where a battery housing tray is used singly or used in a top stage, opening of a vent mechanism, which may cause ignition or explosion in the surrounding batteries, is not observed. In particular, as sample 7, it is shown that by setting the height of the first barrier rib member to be not less than 80% of the height of the battery, a short circuit in the electrode group in the surrounding batteries can be suppressed sufficiently.
[0182] However, as sample C2, in a battery housing tray having a first barrier rib member whose height is about 40% of the height of the battery, opening of a vent mechanism, which may cause an induced explosion or ignition in the surrounding batteries by ignition or explosion of the battery in the center part, is observed in five batteries out of eight batteries. In some batteries, ignition or explosion occurs. This is thought to be because by providing a first barrier rib member having a predetermined height, opening of a vent mechanism, which may cause an induced explosion or ignition in the surrounding batteries, does not occur, and therefore ejection of an electrolytic solution can be efficiently prevented.
[0183] From the above mention, it is shown that when batteries are housed in the battery housing trays that are stacked, an assembled battery housing tray capable of securing sufficient safety can be obtained when the height of the first barrier rib member in the battery housing tray in at least the top stage of the stacked trays is made to be the height exceeding 50% of the height of the battery. In the battery housing trays other than that in the top stage, batteries can be housed inside of the first barrier rib member and the second barrier rib member. Therefore, it is shown that when an air hole is provided or formed, the ratio of the height of each barrier rib member to the height of the battery is not particularly considered.
[0184] Furthermore, as shown in Table 2, when comparison between samples 5 to 8 and sample 9 is carried out, the temperature rise in the surrounding batteries is slightly larger in sample 9. This is thought to be because a gap portion, which is formed between the first barrier rib member with a height is about 40% of the height of the battery and the second barrier rib member, is used as an air hole, so that more heat is applied to the vicinity of the electrode group in the battery as compared with a battery housing tray having an air hole in the vicinity of an exhaust air valve of the battery. However, when the gap portion is about 5 mm, it is thought that safety is secured.
INDUSTRIAL APPLICABILITY
[0185] The present invention is useful as a battery housing tray for housing a battery and the like, which requires high reliability and safety.
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A PTC resistor according to the present invention comprises at least one PTC composition which comprises at least one resin and at least two conductive materials. The at least two conductive materials comprises at least two conductive materials different from each other. The at least one PTC composition may comprise a first PTC composition which comprises a first resin and at least one first conductive material and a second PTC composition which is compounded with the first PTC composition and comprises a second resin and at least one second conductive material. The at least one first conductive material is at least partially different from the at least one second conductive material. One of the first resin and the second resin may comprise a reactant resin and a reactive resin which is cross-linked with the reactant resin. The PTC resistor may comprise a flame retardant agent. The PTC resistor may comprise a liquid-resistant resin.
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TECHNICAL FIELD
The invention relates generally to apparatus and method for ultra-high resolution sampling of rapidly changing waveforms of output signals generated by a signal source. In particular, the inventino relates to a time domain reflectometer system which utilizes Josephson junction technology.
BACKGROUND OF THE INVENTION
The use of superconducting devices, and particularly Josephson tunnelling devices, in sampling or A/D circuits is already known in the art. Use of a Josephson device provide a very sensitive detector offering the possibility of very fast sampling speeds because such a device is capable of extremely fast switching speed between two stable states and because the device responds to extremely small magnetic fields. U.S. Pat. No. 4,401,900 shows a Josephson sampling technique with a time resolution of 5 picoseconds and a sensitivity of 10 microvolts. The time resolution of the described sampling system is extendable to the sub-picosecond domain, limited ultimately by the intrinsic switching speed of the Josephson device used as the sampling gate. In principle, the switching speed can be as fast as 0.09 picoseconds. Josephson sampling techniques are not restricted to only those waveforms produced in a cryogenic environment. Rather, they can be used to measure waveforms from various sources, such as x-rays, optical photons or electrical waveforms produced by room-temperature sources, if a suitable interface is available. Examples of such interfaces are described in the co-pending patent applications Ser. No. 796,841, entitled "Room Temperature to Cryogenic Electrical Interface" filed on Nov. 12, 1985 and Ser. No. 796,842, entitled "Open Cycle Cooling of Electrical Circuits" filed on Nov. 12, 1985.
The Josephson sampling system described in U.S. Pat. No. 4,401,900 comprises a superconductive monitor gate, such as a single Josephson device, which has at least two states distinguishable from one another and which is sensitive to the unknown waveform or signal to be sampled. Switching means, which includes the source of the unknown signal, a source of timing pulses, and a source of a bias signal, changes the state of the monitor gate by a proper combination of the above signals. A timing means is provided to establish both a timing reference and an accurate sampling delay time. The timing means includes a pulse generator for providing very short sampling pulses, delay lines, and a source of trigger pulses. The sampling system also has noise elimination means to ensure the accuracy of the sample at any given instant of time and a display to indicate the unknown waveform.
Sampling systems, however, are inadequate to accurately measure discontinuities of network connections and to determine parameters of certain networks and devices. In such applications, time domain reflectometers, which comprise sampling circuitry with a step or pulse source, are needed. Such a device usually supplies a pulse of a very short duration or a step with a very short rise time. The shorter the rise time, the higher the time accuracy and the finer the details which can be measured by the sampling circuitry. The only time domain reflectometer system (TDR system) that is known to the applicants as being available commercially is manufactured by Tektronix, Inc. of Beaverton, Oreg. as a plug-in module to its 7000 series oscilloscope. The TDR system consists of the sampling system plus a separate pulse generator and has a system rise time of more than 40 picoseconds.
One problem of existing TDR systems, such as the one described above, is the relatively long system rise time which is inadequate for displaying rapidly changing waveforms. A second problem is that existing TDR systems have the sampling circuitry separate from the pulse generator. Thus, if an existing superconducting sampling system is utilized to overcome the rise time problem, the pulse generator of the TDR system would be separate from, and only bonded to, the integrated circuit chip upon which the sampling circuitry is formed. Such a bond, however, has been shown to have a reliability risk, as well as performance limitations. Further, it has been shown by the aforementioned co-pending applications that the thermal, mechanical and electrical constraints that must be satisfied in order to perform superconducting sampling of room-temperature devices can be obviated by a monolithic chip having all the particular circuitry and high performance transmission lines formed theron.
SUMMARY OF THE INVENTION
The foregoing problems are obviated by the invention, comprising:
(a) means for generating and transmitting a trigger signal to the signal source to initiate a transmission of the output signal to the sampling system;
(b) means for generating and introducing sampling pulses with the transmission of the output signal to the sampling system;
(c) means for sampling the output signal comprising an adjustable bias signal source and a superconducting sampling gate having at least two distinguishable states to which the output signal, said sampling pulses and a bias signal provided by said adjustable bias signal source is applied for switching the state of said gate in sampling the output signal; and
(d) means for providing an adjustable time delay in the application of said sampling pulses with respect to the application of said trigger signal.
Advantageously, the use of superconducting sampling, employing, in particular, Josephson junction technology, in a TDR system increases the switching speed of such a system and obtains a system rise time of less than 10 picoseconds. In addition, the invention integrates on a single integrated circuit chip, a step generator, sampling circuitry, filter elements and ultrahigh performance transmission lines. Such a chip is optimized with respect to satisfying electrical, thermal and mechanical constraints imposed by the extremely low operating temperatures at which Josephson junction circuitry must function. Such a chip also achieves minimum jitter during the operation of the TDR system since all the circuitry formed thereon, which already has reduced jitter as a result of utilizing Josephson junction technology, is subject to the same random disturbances which may occur. Further, the invention provides for a novel step generator and novel delay mechanism which take advantage of Josephson junction technology.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, reference is made to the following description of an exemplary embodiment thereof, and to the accompanying drawings, wherein:
FIG. 1 is a schematic representation of the layout/architecture of an integrated circuit chip having formed thereon a TDR system of the present invention;
FIG. 2 is an electrical schematic diagram of a TDR system of the present invention;
FIG. 2a is a graphical representation of the sampling operation of a sampling gate of the TDR system of FIG. 2;
FIGS. 3a-3e are electrical schematic diagrams of several embodiments of a step generator of the TDR system of FIG. 2;
FIG. 4a is an electrical schematic diagram of a buffer gate and a pulse generator gate of the TDR system of FIG. 2;
FIG. 4b is an electrical schematic diagram of a sampling gate and a delay gate of the TDR system of FIG. 2;
FIG. 4c is an electrical schematic diagram of an alternative embodiment of a delay generator of the TDR system of FIG. 2;
FIG. 5a is a schematic representation of the vertical profile of the structure of the step generator of FIGS. 3a-3e;
FIG. 5b is a schematic representation of the vertical profile of the structure of the pulse generator gate and the buffer gate of FIG. 4a; and
FIGS. 6a-6c are electrical schematic diagrams of several embodiments of a TDR system of the present invention utilizing direct coupling.
DETAILED DESCRIPTION
FIG. 1 shows the layout/architecture of an integrated circuit chip 10 that has formed thereon a TDR system of the present invention. The chip 10 comprises an elongated substrate 11 whose material and physical dimensions are dependent upon the particular application. Fabricated at one corner of the substrate 11 by a known method is a time domain reflectometer system (TDR system) 12 which utilizes Josephson junction circuitry. The area of the substrate 11 on which the TDR system 12 lies, as indicated by the dashed line in FIG. 1, is cooled to cryogenic temperatures, for example, according to the apparatus and method of the co-pending application Ser. Nos. 796,841 or 796,842; the remaining substrate 11 area is at room temperature. A number of non-critical biasing and monitoring lines 13, which may be of niobium or gold, connect to the TDR system 12 and extend most of the length of the substrate 11 to a group of connection or bonding pads 14 which act as the low frequency interface for bonding to room temperature circuitry off the chip 10. High performance transmission lines 15, 16, which also may be of niobium or gold, extend from the TDR system 12 to a high frequency interface 17 at the other end of the substrate 11 which connects to a device under test (DUT) whose waveforms are to be sampled and measured. The physical constraints that the high performance transmission lines 15, 16 must satisfy in order to maintain the necessary performance for sampling and measuring are described in the co-pending application Ser. No. 796,841.
FIG. 2 is an electrical schematic diagram of a TDR system 20 of the present invention connected to a device under test (DUT) whose output signal waveform, I x (t) is to be sampled and measured. The TDR system 20 comprises a sampling gate 21 which has connected thereto a noise filter circuit 21a and magnetically-coupled thereto an adjustable bias current circuit 21b, a portion of which may be off the chip 10. The sampling gate 21 utilizes superconducting devices, such as a Josephson tunnelling device, to perform sampling of waveforms. Such superconducting sampling gates are well known in the art, for example, as described in U.S. Pat. No. 4,401,900. A particular configuration of the sampling gate 21 is described in detail with respect to FIG. 4b. Note that the sampling gate 21 may also be connnected to other room temperature electronics including a display unit to view the DUT waveform as well as other signal processing circuitry.
The TDR system 20 also comprises a pulse generator gate 22 which is magnetically-coupled to the sampling gate 21 via a resistor 22a-Josephson junction device J1 series and provides a samplng pulse, I p to the sampling gate 21 via said coupling. The pulse generator gate 22 is also tied to a noise filter circuit 22b and a first delay circuit interface 24. A pulse generator gate which uses superconducting circuitry is also well known in the art, for example, as described in U.S. Pat. No. 4,401,900. The first delay circuit interface 24 comprises an inductor 24a which ties the pulse generator gate 22 to the remainder of the interface 24. The inductor 24a is connected to an external delay circuit, Q pc off the chip 10 via a low-pass resistor 24b-capacitor 24c circuit. The inductor 24a is also connected, via a resistor 24d, to a Josephson junction device J2 which triggers the pulse generator gate 22. The Josephson junction device J2 is tied to an external DC current source I pp off the chip 10 via a low-pass resistor 24e-capacitor 24f circuit in series with a noise filter 24g. The Josephson junction device J2 is also tied directly to a delay generator 29 to be described later.
The TDR system 20 further comprises a step generator 25 which is connected to a noise filter circuit 25a and, via a chip transmission line 25b having a resistive termination 25c and the high performance transmission lines 15, 16, is connected to the device under test (DUT). The chip transmission line 25b is magnetically-coupled to the sampling gate 21 and the pulse generator gate 22. The step generator 25 outputs a voltage step signal, I s on the chip transmission line 25b with a fast rise time, e.g., less than 10 picoseconds, which is necessary in a high performance electrical system such as a time domain reflectometer. Similar systems include logic circuit drivers and differentiating pulse generators. Several configurations for the step generator 25 utilizing Josephson junction technology are described with respect to FIGS. 3a-3e.
The step generator 25 is also magnetically-coupled to a step driver gate or buffer gate 26, via a resistor 26a-Josephson junction device J3 series. The buffer gate 26 utilizes Josephson junction technology to supply a trigger signal, I d to the step generator 25 via said magnetic coupling. The buffer gate 26 is also connected to a noise filter circuit 26b and a second delay circuit interface 28 which has the same circuit configuration as the first delay circuit interface 24. An inductor 28a ties the buffer gate 26 to the remainder of the interface 28. The inductor 28a is connected, via a low-pass resistor 28b-capacitor 28c circuit, to an external delay circuit, Q dc off the chip 10. Note that the connection to the external delay circuit Q dc is preceded by a magnetic-coupling to the delay gate of delay generator 29. The inductor 28a is also connected, via a resistor 28d, to a Josephson junction device J4 which triggers the buffer gate 26. The Josephson junction device J4 is tied to an external DC current source I dd off the chip 10 via a low-pass resistor 28e-capacitor 28f circuit in series with a noise filter 28g. The Josephson junction device J4 is also directly tied to the delay generator 29.
Both interfaces 24, 28 are tied to the delay generator 29 via respective input resistors 29a, 29b. The input resistors 29a, 29b are tied to a capacitor bank comprising a shunt resistor 29c-capacitor 29d series, a first low-pass resistor 29e-capacitor 29f circuit and a second low-pass resistor 29g-capacitor 29h circuit. The second low-pass circuit, in turn, is tied to a delay gate 29i. The delay gate 29i, which uses superconducting circuitry, is magnetically-coupled to an external trigger source TRIG off the chip 10, via a noise filter 29k, and is connected to the second delay circuit interface 28 as mentioned previously. The delay generator 29 is also connected to two noise filters 29m, 29n. Note that all the noise filters of the TDR system 20, as well as the other described connections to external electronics, are connected to electronics off the chip 10 via the biasing lines 13 shown in FIG. 1.
In operation, the buffer gate 26 and the associated Josephson junction device J3 produce a pulse signal, I D which triggers the step generator 25 to output a step signal, I s to the device under test (DUT). In response, the DUT then operates an output signal waveform, I x (t) which is transmitted back along the chip transmission line 25b. The pulse generator gate 22 and the associated Josephson junction device J1 produce a sampling pulse, I p which is applied to the sampling gate 21 via the magnetic-couple therebetween. The sampling gate 21 is a threshhold device which will change its state when the summation of the inputs thereto exceeds a threshold value. As graphically illustrated by FIG. 2a, the sampling gate 21 thus uses the samplng pulse, I p from the pulse generator gate 23, the output signal waveform, I x (t) and a bias current signal, I B from the bias current circuit 21b in order to change its voltage state. Since the threshold value is at a constant amplitude, the value of the bias current signal, I B will track the amplitude of the output signal waveform, I x (t) if the amplitude of the sampling pulse, I p is held constant. In this manner, the output signal waveform, I x (t) can be reconstructed by the sampling gate 21 in both amplitude and shape to provide an accurate reconstruction including both rise time and fall time increments of that signal.
The generation of the step signal, I s and the introduction of the sampling pulse, I p , which sweeps across the step signal and the resulting output signal, I x (t), and the timing or delay therebetween can be implemented and adjusted in one of three ways by the TDR system 20. An external delay can be produced by the trigger signal, delayed with respect to one another, delivered from circuitry off the chip 10, i.e., the external delay circuits Q pc , Q dc , via the first and second delay circuit interfaces 24, 28. As can be seen from FIG. 2, the external delay circuits Q pc , Q dc trigger the respective Josephson junction devices, J2, J4 which in turn trigger the respective gates 22, 26. Such circuitry can change the power bias that affects the triggering of the pulse generator gate 22 and the buffer gate 26, and thus, in turn, also the step generator 25. Note that the trigger signals are ultimately derived from the TDR system 20 clock off the chip 10. On-chip delay is provided by the switching of the delay gate 29i which causes charging of the capacitor bank of the delay generator 29. The resistor-coupled capacitors are used to reduce internal resonances which could affect sweep linearity. As the capacitors charge, the currents of the trigger signals delivered from the external delay circuits Q pc , Q dc and feeding to the Josephson junction devices J2, J4 of the interfaces 24, 28 change. The switching of those devices are then determined by externally supplied currents from the external DC current sources I pp , I dd via the interfaces 24, 28 which compensate for the change in current and thus control the triggering of the pulse generator gate 22 and the buffer gate 26. Note that initiation of a timing cycle, i.e., the switching of the delay gate 29i, is triggered by the external trigger source TRIG whose signal is derived from the TDR system 20 clock off the chip 10. Another on-chip delay mechanism is to externally supply the same trigger signal to the pulse generator gate 22 and the buffer gate 26 but to produce the delay therebetween by adjusting the external DC current sources I pp , I dd and, thus, the currents received by the first and second interfaces 24, 28. This changes the switching points of the associated Josephson junction devices J2, J4 and, thus, controls the triggering of the sampling pulse I p and the step signal, I s .
Note that the use of Josephson junction devices by the TDR system 20 provides the system with an inherent ability to reduce jitter during waveform sampling because a Josephson junction device's switching threshhold value is unambiguous. Furthermore, the present invention improves on existing systems by integrating the sampling gate 21, the pulse generator 22 and the step generator 25 on a single chip and, thus, minimizes the randomness of noise between the various inputs needed for sampling. The use of external delay circuits Q lpc , Q dc achieves sufficiently low jitter to provide a TDR system 20 resolution of below 15 picoseconds; however,the described on-chip delay mechanism achieve even lower jitter and provide better resolution if necessary. Such superconducting delay mechanisms of the present invention thus provide minimum jitter without being cumbersome like mechanical delay lines or limited to slowly changing waveforms like room temperature delay circuitry.
FIGS. 3a through 3e show electrical schematic diagrams of several embodiments of the step generator. FIG. 3a shows the basic configuration of a step generator 30 which comprises a configuration of triggerable devices 31 which magnetically-couple to the buffer gate 26, such as interferometers, and a network 33 which may be either purely resistive or a connected series of Josephson junction devices. A resistor 34-inductor 35 series connects the triggerable devices 31 to the network 33. The network 33 is also directly connected to the chip transmission line 36 having a resistive termination 37. FIG. 3b shows a simple implementation where the configuration of triggerable devices 31 comprises one symmetric two-Josephson junction, magnetically-coupled interferometer and the network 33 comprises a single Josephson junction device.
FIG. 3c shows the configuration of triggerable devices 31 comprising four tightly coupled interferometers of FIG. 3b and the network 33 comprising four Josephson junction devices connected in series. Such an implementation provides a step signal, I s with greater voltage amplitude and provides better stability than a configuration having a smaller number of triggerable devices. This is accomplished because the two stage balanced pseudo-interferometer structures shown in FIG. 3c tend to lock the switching points of the four Josephson junction devices and the fast rise time of the trigger pulse, I D from the buffer gate 26 ensures that the two balanced structures switch with very close time proximity. The switching of the balanced structures causes the four series-connected junctions to switch simultaneously and rapidly, via the action of the inductor 35, to produce the step signal, I s . Note that with the appropriate choice of component values, the step signal, I s can have considerably lower rise time than that produced by the balanced structures only. Rise times of the step signals achieved in the manner described are in the 6 picosecond range. FIG. 3d shows the configuration of triggerable devices 31 comprising a superconducting quantum interference device (SQUID). FIG. 3e shows the configuration of triggerable devices 31 comprising two tightly coupled interferometers of FIG. 3b. Note that the number of triggerable devices in the configuration 31 does not need to be equal to the number of single Josephson junction devices in the network 33.
In order to ensure that the triggerable devices 31 of the step generator 30 switch simultaneously and in a very rapid time, e.g., shorter than 5 picoseconds, the buffer gate 26 must supply enough current to switch the devices 31 comfortably. FIG. 4a shows an electrical schematic diagram of a buffer gate 40 which can provide such a fast control. The buffer gate 40 comprises a symmetric two-Josephson junction, magnetically-coupled interferometer as previously described with respect to FIG. 3b. The pulse generator gate of the TDR system can utilize the same device and configuration since the circuit connections of both gates are similar. FIG. 4b shows the electrical schematic diagram of the sampling gate 45 and the delay gate which can utilize the same circuity. Both gates comprise s symmetric two-Josephson junction, magnetically-coupled interferometer as described with respect to FIG. 3b but whose orientation is reversed.
FIG. 4c shows a delay generator of the TDR system 20 which utilizes multi-stage inductive coupling rather than capacitor charging to produce a timing delay for the introduction of the sampling pulse, I p by the pulse generator gate. The delay generator 47 comprises a plurality of symmetric two-Josephson junction, magnetically-coupled interferometers 47a, as described with respect to FIG. 3b, which are magnetically coupled to one another in a series. Each interferometer 47a has an associated shunt resistor 47c inductor 47d series. The interferometers 47a are also tied to a current source, which may be off the chip 10, via noise filters (not shown). A delay control line 48a, shown running adjacent to the interferometers, is connected to, for example, a sawtooth generator off the chip 10. The trigger of the delay generator 47 can be an inductively-coupled trigger or, as shown, can be the external delay circuit, Q pc which is directly connected via a low-pass resistor 48b-capacitor 48c circuit. The output of the delay generator 47 can also be transmitted via magnetic-coupling, but, as shown, the output is directly tied to an inductor 48d which, in turn, is tied to a pulse generator gate 49. With respect to FIG. 2, the delay generator 47 of FIG. 4c would be placed between the low-pass resistor 24b-capacitor 24c circuit and the inductor 24a of the first delay circuit interface 24. The remainder of the interface 24 would be eliminated as would the shown delay generator 29 and the second delay circuit interface 28. In the case of the latter, the buffer gate 26 would be tied to the external pulsed DC durrent source, I dd via the inductor 28a. Thus, the delay generator 47 of FIG. 4c acts to only provide a delay to the sampling pulse, I p and not to the step signal, I s . In operation, the delay generator 47 provides a delay when the delay control line 48a signals the interferometers 47a to change their respective switching points to thus control the triggering of the pulse generator gate 49. The total delay achieved is equal to the product of the number of interferometer stages and the delay of each stage. Note that the interferometer stages may instead by directly connected to achieve the same operation.
FIG. 5a shows a schematic representation of a top view and two vertical profiles of a step generator of the present invention as fabricated on the substrate 11 of a chip 10. The top view of the step generator shows four Josephson junction devices of the step generator formed on the substrate 11. A first vertical profile A shows the cross-section of the Josephson junction devices along line A--A. The profile A comprises a three layer base M1 having a thin layer of aluminum oxide (Al 2 O 3 ) sandwiched between two layers of niobium (Nb). The base M1 is patterned and anodized using niobium oxide (Nb 2 O 5 ) so as to leave exposed the areas upon which the Josephson junction devices are formed. A first interconnection lever M2 comprises niobium (Nb) is the next layer, such that the M1-M2 interfaces have the Josephson junction devices therebetween. On the first interconnection level M2 is a resistor layer (not shown) and an insulating layer of silicon dioxide (SiO 2 ). A second interconnection level M3 is also comprised a niobium (Nb) which has a gold (Au) contact layer formed thereon as shown. A second vertical profile B shows the cross-section of the step generator along line B--B. FIG. 5b shows a schematic representation of a top view and a vertical profile of a pulse generator gate and a buffer gate of the present invention which are both fabricated on the substrate 112 of a chip 10 in the same manner. The top view of the gate shows two Josephson junction devices of the gate formed on the substrate 11. A vertical profile C shows the cross-section of the Josephson junction devices along line C--C and, although of a different configuration, is the same layered structure as described above for the step generator.
FIG. 6a shows an electrical schematic diagram of a TDR system 60 of the present invention which utilizes direct coupling between a sampling gate 61 and the various input signal sources. The sampling gate 61 has a circuit configuration as shown in FIG. 4a and is tied to the device under test (DUT) via a first chip transmission line 62 which has a resistive termination 63 therebetween. The sampling gate 61 is also connected directly to an associated noise filter circuit 61b and a bias current circuit 61c. A pulse generator 64 is connected directly to the sampling gate 61 via a resistor 64a-Josephson junction device J1 series. A step generator 65 is connected directly to the DUT via a second chip transmission line 66 having a resistive termination 67. The two chip transmission lines 62, 66 are tied together to form one path to the DUT. Unlike the TDR system 20 of FIG. 2, the TDR system 60 of FIG. 6a splits the current of the step signal, I s sent out by step generator 65 as well as the current of the output signal, I.sub. x (t) of the DUT in order to measure and sample the output signal waveform. A disadvantage of the "direct-coupled" TDR system of FIG. 6a is the super-imposing effect on the transmission lines caused by the current splitting of the step and output signals. However, the operation of the TDR system 60 remains the same as previously described and sampling of an extremely fast waveform is still possible. FIGS. 6b and 6c show other configurations of direct-coupled TDR systems where the step generator 65 is tied to the sampling gate 61 in different but operable manners. In these configurations, the step generator 65 comprises a configuration of triggerable devices 65a with a network 65b shunted across. However, unlike the embodiments shown in FIGS. 3a-3c, there is no need for resistor and inductor components on the interconnection line therebetween or on the chip transmission line. Further, the network 65b is optional. If used, the network 65b may be, for example, a resistive network for matching the dynamics of the configuration of triggerable devices 65a. The same limitations of FIG. 6a regarding performance also hold true.
It is to be understood that the embodiments described herein are merely illustrative of the principles of the invention. Various modifications may be made thereto by persons skilled in the art without departing from the scope or spirit of the invention.
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A circuit is provided for sampling and accurately reproducing unknown signals, which could be electrical, optical, X-ray, gamma ray or particle signals, with picosecond resolution. The circuit comprises a superconductive sampling gate having at least two states which are distinguishable from one another and switching circuitry to switch the state of the sampling gate. The switching circuitry includes a sampling pulse source and a bias current source which are combined with the unknown signal to change the state of the monitor gate. A step generator utilizing Josephson junction technology is connected to the source of the unknown signal and sends a signal to the source of the unknown signal in order to initiate the outputting of the unknown signal and thus the sampling. Timing circuitry, also utilizing Josephson junction technology, provides an adjustable delay between the step signal generation and the sampling pulse generation.
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FIELD
[0001] The present embodiments relate to a method of creating an aged, collectable ethanol-containing beverage.
BACKGROUND
[0002] A need exists for an ethanol-containing beverage that possesses improved flavor.
[0003] A need exists for a method of creating ethanol-containing beverages with a wide variety of flavors.
[0004] A further need exists for an ethanol-containing beverage that continues to age while on a sale shelf or in a consumer's possession, enabling the ethanol-containing beverage to be sold and used as a marketing tool that increases in value as time passes.
[0005] A need also exists for an ethanol-containing beverage that is collectable, both due to its value as its age increases, and due to the numerous collectable varieties and flavors that can be created.
[0006] The present embodiments meet these needs.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0007] Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular embodiments and that they can be practiced or carried out in various ways.
[0008] The present embodiments relate to a method of creating an aged, collectable ethanol-containing beverage.
[0009] The present process can create a large variety of ethanol-containing beverages with numerous possible flavors by combining one or more ethanol-containing beverages with one or more varieties of wood, then permitting the ethanol-containing beverage to age with the wood. The wood-containing beverages will continue to age, even on a sale shelf or in a consumer's possession, enabling the ethanol-containing beverages to be used as collectable marketing tools that increase in value as time passes.
[0010] The embodied ethanol-containing beverages possess improved flavor, and the large variety of possible combinations of ethanol-containing beverages, wood types, wood preparation methods, and other flavor components such as herbs, flowers, fruits, and vegetables creates a collectable series of beverages, all of which continuously age due to the presence of wood in the container.
[0011] The embodied process can also include additional marketable, collectable features such as unique containers or distinctly shaped wood pieces that can be removed through an opening in the container.
[0012] The process begins by selecting one or more wood pieces useful in imparting one or more flavor components to an ethanol-containing beverage.
[0013] The selected one or more wood pieces are inserted into a container holding an ethanol-containing beverage.
[0014] The ethanol-containing beverage is then permitted to age in the container with the one or more wood pieces.
[0015] The one or more wood pieces are then retained in the container with the ethanol-containing beverage, forming a continuously aging, collectable ethanol-containing beverage with improved flavor.
[0016] The characteristics of the continuously aging, collectable ethanol-containing beverage with improved flavor can be selectively manipulated through changing the temperature, pressure, and length of time for which the ethanol-containing beverage is permitted to age. The speed of the aging process can also be increased through selectively manipulating the temperature and pressure at which the ethanol-containing beverage and the one or more wood pieces are permitted to age.
[0017] The characteristics of the continuously aging, collectable ethanol-containing beverage with improved flavor can also be manipulated through the type of wood selected, the type of ethanol-containing beverage selected, the preparation and form of the wood, and the use of additional flavorings.
[0018] The wood pieces can be any type of wood, including but not limited to oak, maple, hickory, mesquite, cherry, apple, pecan, alder, guava, almond, peach, apricot, acacia, ash, birch, cottonwood, lemon, lilac, mulberry, nectarine, orange, pear, plum, walnut, cedar, pine, grapefruit, lime, chestnut, sycamore, and combinations thereof.
[0019] The wood pieces can also be one or more pieces of bark, one or more whole nut shells, one or more pieces of nut shell, one or more pieces of coconut shell, one or more nuts, and combinations thereof. Nuts or nut shells could include peanuts, pecans, walnuts, chestnuts, cocoa nuts, other nuts, and combinations thereof.
[0020] The one or more selected wood pieces can have any form, including powder, sticks, chunks, chips, or combinations thereof. It is also contemplated that the wood pieces could be provided with a distinct shape, such as fish, stars, one or more individuals' names, a worm shape, a geometrical shape, and other shapes. The one or more wood pieces can be sized such that they are able to fit through an opening in the container.
[0021] In an embodiment, the wood pieces can also be from a used cask for holding wine or ethanol-containing beverages.
[0022] It is also contemplated that the ethanol-containing beverage can be provided in a container for consumer sales, such as a glass or a polymer container. The glass or polymer container can be a container with a volume of 250 ml, 375 ml, 750 ml, 1 liter, 1.75 liter, or other volumes. The container can be transparent to allow the wood contained within the continuously-aging, collectable ethanol-containing beverage to be visible to a consumer. The container could also be uniquely molded or shaped.
[0023] In an embodiment, the container can further comprise a breathable cork stopper or other breathable sealer to allow some oxygen into the container to enhance the continuous aging of collectable ethanol-containing beverage.
[0024] The ethanol-containing beverage can be any ethanol-containing beverage including but not limited to a whiskey, a bourbon, a rum, a brandy, an Armagnac, a cognac, a vodka, a tequila, and an eau de vie.
[0025] In an embodiment the one or more selected wood pieces can be roasted prior to associating the wood pieces with the ethanol-containing beverage. This can be beneficial due to the fact that the aging process is slower when raw wood is used.
[0026] It is also contemplated that the one or more wood pieces can be roasted wood, charred wood, dehydrated wood, dried wood, raw wood, or combinations thereof.
[0027] The roasting of the selected one or more wood pieces can be performed by flash roasting. The flash roasting can have a flame temperature in excess of 2000 degrees Fahrenheit.
[0028] The roasting can also be performed for up to eight hours at a temperature ranging from about 180 degrees Fahrenheit to about 220 degrees Fahrenheit. In other embodiments, the roasting can be performed at 380 degrees Fahrenheit for a time period ranging from two hours to four hours, or at a temperature of 460 degrees Fahrenheit for a time period ranging from one half hour to one hour.
[0029] The one or more selected wood pieces can also comprise additional flavoring, such as vegetable oils, nut oils, fruit extracts, vegetable extracts, spices, or other flavorings disposed therein.
[0030] In an embodiment, the method can further comprise the addition of a small amount of a fruit, a vegetable, a flower, a herb, a spice, or combinations thereof. The fruit, the vegetable, the flower, the herb, the spice, or any combination thereof can be roasted, dehydrated, fresh, dried, or combinations thereof.
[0031] The present embodiments also relate to a beverage produced using the embodied method.
[0032] The beverage comprises an ethanol-containing beverage, such as a whiskey, a bourbon, a rum, a brandy, an Armagnac, a cognac, a vodka, a tequila, or an eau de vie, that has been permitted to age in the container, with one or more selected wood pieces.
[0033] The present embodiments also relate to a marketing tool comprising a continually aging beverage prepared using the embodied method. The ethanol-containing beverage containing one or more selected wood pieces can be used as a marketing tool because the ethanol-containing beverage continues to mature in a container, whether on a sale shelf, or in a consumer's possession, creating a product that increases in value as time passes.
[0034] Due to the wide variety of ethanol-containing beverages, types of wood, wood preparation methods, and additional flavorings that can be used, an entire series of collectable, continuously-aging marketing tools that increase in value as time passes can be created and collected.
[0035] Select containers for consumer sale can be used, such as containers with unique sizes, shapes, or materials. Select wood pieces can also be used, such as uniquely shaped wood pieces, or uniquely sized wood pieces able to fit through an opening in the container. Select corks, stoppers, labels, and other items can be used to further enhance the appearance and commercial appeal of the continuously-aging, collectable ethanol-containing beverage with improved flavor.
[0036] While these embodiments have been described with emphasis on the embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as specifically described herein.
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A method of creating an aged, collectable ethanol-containing beverage comprising the steps of: selecting at least one wood piece useful in imparting at least one flavor component to an ethanol-containing beverage; inserting the at least one wood piece in a container holding the ethanol-containing beverage; permitting the ethanol-containing beverage to age in the container with the at least one wood piece; and retaining the at least one wood piece in the container with the ethanol-containing beverage, forming a continuously aging, collectable ethanol-containing beverage with improved flavor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to luminescent sheets used as advertising media, decorative media, or security sheets, which are applied to windows of commercial buildings, vehicles, and the like, and also relates to a method of producing the same.
2. Background Art
In order to produce a special-purpose decorative material (sheet) having see-through property, on both sides of which different images are separately formed, the following methods and the like have been suggested and practically used: a method of obtaining a special-purpose decorative material, wherein sheets, upon each of which an image consisting of different pixels is drawn in dots, are laminated to each other in an accurate manner and then one of the sheets is removed such that pixels of the removed sheet are transferred onto pixels of the other sheet (JP Patent Publication (Kokai) No. 5-92694 A (1993)); and a method wherein inks having different adhesion properties are used for image drawing and then unnecessary ink portions are selectively removed using an adhesive sheet (JP Patent Publication (Kokai) No. 5-92695 A (1993)). At present, in view of design properties, special-purpose decorative materials have been widely used in stores and on commercial vehicles for both commercial and private uses.
However, special-purpose decorative materials produced by the above methods have the drawback of being only visible in the daytime or under lighting, but being invisible at night.
SUMMARY OF THE INVENTION
It is an objective of the present invention to provide a luminescent decorative material, which is visible even in no-light environments at night, of which different decorative properties are visible in the daytime or under lighting due to the presence or absence of luminescence caused by intentional switching of a power source between on-off modes.
The present invention is summarized as follows.
(1) A luminescent sheet, which is a plane sheet, having see-through property and comprising a transparent part, through which it is possible to see the area behind the plane sheet, and a luminescent part.
(2) The luminescent sheet according to item (1), wherein the luminescent part comprises a 1 st transparent electrode layer, a luminescent layer, and a 2 nd transparent electrode layer.
(3) The luminescent sheet according to item (2), wherein either one of or both the 1 st transparent electrode layer and the 2 nd transparent electrode layer is/are formed in stripe pattern.
(4) The luminescent sheet according to any one of items (1) to (3), partially containing a see-through control part comprising a see-through control layer.
(5) The luminescent sheet according to item (4), wherein the see-through control layer is prepared with a colored conductive material or coloring ink.
(6) The luminescent sheet according to any one of items (1) to (5), having a dielectric layer.
(7) The luminescent sheet according to item (6), wherein at least the luminescent layer, the see-through control layer, and the dielectric layer are formed in a matrix pattern.
(8) The luminescent sheet according to any one of items (2) to (7), wherein the 1 st transparent electrode layer and the 2 nd transparent electrode layer are both formed in stripe pattern and the stripe pattern are not parallel to each other.
(9) The luminescent sheet according to any one of items (1) to (8), which is produced by patterning.
(10) The luminescent sheet according to item (9), wherein the patterning is carried out using masking tape or by screen printing, inkjet printing, or gravure printing.
(11) A luminescent decorative material, which is obtained by printing on the luminescent sheet according to any one of items (1) to (10) in a manner such that the transparent part, through which it is possible to see the area behind the plane sheet, is remaining.
(12) A method of producing the luminescent sheet having see-through property according to item (2), comprising the steps of:
forming at least a 1 st transparent electrode layer and a luminescent layer on a 1 st transparent substrate so as to prepare a 1 st laminate;
forming at least a 2 nd transparent electrode layer on a 2 nd transparent substrate so as to prepare a 2 nd laminate; and
allowing the 1 st laminate and the 2 nd laminate together.
(13) The method according to item (12), wherein the dielectric layer is formed on the luminescent layer of the 1 st laminate and then the 1 st laminate is joined the 2 nd laminate.
(14) The method according to item (13), wherein patterning is carried out in a manner such that at least the luminescent layer and the dielectric layer are formed in a matrix pattern.
(15) The method according to item (14), wherein patterning is carried out using masking tape or by screen printing, inkjet printing, or gravure printing.
Effects of the Invention
According to the present invention, it is possible to provide a luminescent decorative material, of which a wide variety of decorative properties are visible under various lighting environments such as day and night environments and well-lit and dark rooms.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plane view of a luminescent sheet for explanation of the present invention.
FIG. 2 illustrates a state in which masking tape has been applied to a 1 st transparent substrate (polyethylene terephthalate sheet).
FIG. 3 illustrates a state in which a transparent conductive membrane has been formed.
FIG. 4 illustrates a state in which masking tape has been applied in perpendicular direction against the transparent conductive membrane of FIG. 3 .
FIG. 5 illustrates a state in which a luminescent layer has been coated.
FIG. 6 illustrates a state in which masking tape has been removed from the state shown in FIG. 5 .
FIG. 7 illustrates a state in which a transparent conductive membrane has been formed on a 2 nd transparent substrate (polyethylene terephthalate sheet).
FIG. 8 illustrates a state in which the ITO face shown in FIG. 7 has been laminated to a luminescent layer shown in FIG. 6 so that they are bonded together.
FIG. 9 is a cross-sectional view for explanation of a preferred embodiment of the present invention.
FIG. 10 is a cross-sectional view for explanation of a preferred embodiment of the present invention.
FIG. 11 illustrates connection status upon voltage application.
FIG. 12 illustrates a state in which a dielectric layer has been laminated to the luminescent layer shown in FIG. 5 .
FIG. 13 illustrates a state in which a see-through control layer is laminated to the dielectric layer shown in FIG. 12 .
FIG. 14 illustrates a state in which masking tape has been removed from the state shown in FIG. 13 .
FIG. 15 illustrates a state in which the ITO face shown in FIG. 7 has been laminated to a see-through control layer shown in FIG. 14 so that they are bonded together.
FIG. 16 is a plane view of the luminescent decorative material of the present invention.
Each numeral and character in the figures means the following.
a - - - transparent part b - - - luminescent part 1 - - - 1 st transparent substrate (polyethylene terephthalate sheet) 2 - - - masking tape 2 ′ - - - masking tape 3 - - - 1 st transparent electrode layer (transparent conductive membrane) 4 - - - luminescent layer 5 - - - dielectric layer 6 - - - see-through control layer 7 - - - 2 nd transparent substrate (polyethylene terephthalate sheet) 8 - - - 2 nd transparent electrode layer (transparent conductive membrane)
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The luminescent sheet (plane sheet) of the present invention comprises a transparent part (a), through which it is possible to see the area behind the plane sheet, and a luminescent part (b) as shown in FIG. 1 . Herein, the term “transparent part (a)” indicates a transparent part through which it is possible to see the area behind the plane sheet. The term “luminescent part (b)” indicates a luminescent part comprising a luminescent layer 4 described below. Further, it is preferable that the luminescent sheet of the present invention have an image printed thereon in a manner such that a see-through transparent part thereof is remaining.
With the above configuration, when the area behind a plane sheet is brighter than the area in front thereof, an observer in front thereof can see the area behind the plane sheet. In such case, even when the surface of a plane sheet has an image printed thereon, such image is only visible with difficulty (but depending on brightness) and thus the area behind the plane sheet is visible. Meanwhile, when the area behind a plane sheet is darker than the area in front thereof, the area behind the plane sheet is only visible with difficulty. In such case, if the surface of a plane sheet has a text or image printed thereon, such printed text or image is clearly visible.
In addition, when the luminescent part is allowed to emit light, it becomes difficult to see through the plane sheet even in a case in which the area behind the plane sheet is bright. As a result, the plane sheet itself is bright. Further, if the surface of the plane sheet has a text or image printed thereon, effects can be obtained whereby such printed text or image looks shiny due to backlight.
In a preferred embodiment of the luminescent sheet of the present invention, at least a 1 st transparent electrode layer 3 , a luminescent layer 4 , and a 2 nd transparent electrode layer 8 are provided on a 1 st transparent substrate 1 as shown in FIG. 9 . In the above preferred embodiment, either one of or both the 1 st transparent electrode layer 3 and the 2 nd transparent electrode layer 8 is/are formed in stripe pattern. Preferably, both layers are formed in stripe pattern.
A preferred embodiment of the present invention contains a dielectric layer 5 and/or partially contains a see-through control layer 6 as shown in FIG. 10 .
In FIG. 10 , a dielectric layer 5 is provided between a luminescent layer 4 and a see-through control layer 6 , but its location is not limited thereto. Thus, the dielectric layer 5 may be provided between a 1 st transparent electrode layer 3 and a luminescent layer 4 or between a see-through control layer 6 and a 2 nd transparent electrode layer 8 .
Further, in FIG. 10 , the see-through control layer 6 is provided between the dielectric layer 5 and the 2 nd transparent electrode layer 8 , but its location is not limited thereto. It may be provided between the luminescent layer 4 and the dielectric layer 5 , between the 2 nd transparent electrode layer 8 and a 2 nd transparent substrate 7 , or on the surface of the 2 nd transparent substrate 7 that is opposite the surface on which the 2 nd transparent electrode layer 8 has been provided. In a plane view, it is preferable that a see-through control part comprising the see-through control layer 6 be partially provided. Preferably, such see-through control part is provided at a location at which it overlaps a luminescent part. Preferably, the size of a see-through control part is as large as or larger than that of the corresponding luminescent part in a manner such that the luminescent part is entirely covered by the see-through control part. With such configuration, when an illuminated face (which is on the opposite side of the luminescent layer against the face on which the see-through control layer exists) is emitting, it is possible to prevent light leaking to the face opposite the illuminated face. The see-through control layer must be provided on the opposite side of the luminescent layer against the side on which desired luminescence is caused.
In a preferred embodiment of the present invention, the above see-through control layer 6 is prepared with a colored conductive material or coloring ink. In a preferred embodiment of the present invention, stripe pattern of the 1 st transparent electrode layer 3 and those of the 2 nd transparent electrode layer 8 are not parallel to each other. More preferably, they are orthogonal to each other.
A transparent substrate used for the luminescent sheet of the present invention is not particularly limited as long as it is transparent. However, it is preferable that such transparent substrate be flexible. Examples of material used for such transparent substrate include: polyester such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate; polycarbonate; polyamide such as wholly aromatic polyamide, nylon 6, nylon 66, or nylon copolymer; polyacrylate such as polymethyl methacrylate; and glass. Such transparent substrate is used in a sheet form having a thickness of approximately 10 to 150 μm.
Examples of material used for a 1 st transparent electrode layer and a 2 nd transparent electrode layer include, but are not particularly limited to: a thin film made of metallic oxide such as indium tin oxide (ITO), indium zinc oxide, indium oxide, or tin oxide; and a ultra-thin film made of a noble metal. When a thin film made of metallic oxide is used as a 1 st transparent electrode layer and a 2 nd transparent electrode layer, the thickness thereof is generally 50 to 50000 nm. A 1 st transparent electrode layer and a 2 nd transparent electrode layer can be formed by physical deposition methods such as a vacuum deposition method, an ion plating method, and a sputtering method, by chemical vapor deposition methods such as a thermal CVD (chemical vapor deposition) method, a plasma CVD method, and a photo-CVD method, or by printing or coating with the use of a conductive paste dispersed in a binder or the like.
According to the present invention, a luminescent layer is provided between a 1 st transparent electrode layer and a 2 nd transparent electrode layer. When a luminescent layer is transparent, it may be formed in all of a planar layer in a manner such that it covers one surface of each transparent electrode layer. When a luminescent layer is opaque, it must be partially provided in a manner such that a transparent part (of a luminescent sheet) is remaining. Further, a luminescent layer is preferably formed in a matrix pattern. Furthermore, a luminescent layer is preferably provided at a location at which it is sandwiched between a 1 st transparent electrode layer and a 2 nd transparent electrode layer.
Material used for a luminescent layer is not particularly limited as long as material such as EL (electroluminescence) material that can emit light is used. Examples of such material that may be used include: inorganic EL material such as ZnS:Cu or ZnS:Mn; low-molecular-weight organic EL material such as an aluminum-quinolinol complex or an aromatic diamine derivative (e.g., a triphenyldiamine derivative); and high-molecular-weight organic EL material such as polyphenylene vinylene. In general, a luminescent layer has a thickness of 0.1 to 50 μm. For instance, when inorganic EL material is used, a luminescent layer can be formed by sputtering or coating with the use of a solution containing luminescent material, followed by drying. When organic EL material is used, a vacuum deposition method, an inkjet method, or the like can be used.
According to the present invention, it is preferable to provide a dielectric layer for the improvement of luminescence efficiency. A dielectric layer is provided between a 1 st transparent electrode layer and a 2 nd transparent electrode layer and preferably between a luminescent layer and a 2 nd transparent electrode layer. In addition, a dielectric layer is preferably formed in a matrix pattern. Further, a dielectric layer is preferably provided at a location at which it is sandwiched between a luminescent layer and a 2 nd transparent electrode layer. Preferred examples of material used for a dielectric layer include high-dielectric constant materials such as barium titanate, silicon oxide, silicon nitride, antimony-doped tin oxide, and yttrium oxide. The thickness of a dielectric layer is generally 0.1 to 50 μm. A dielectric layer can be formed by, for example, sputtering or by coating with the use of a solution containing the above material, followed by drying.
Further, according to the present invention, it is preferable to partially provide a see-through control layer having a black or brown color that causes relatively little reflection or scattering of exterior light. When such see-through control layer is provided, specific effects can be obtained whereby it is difficult to see the area behind a luminescent sheet through an illuminated face thereof while it is relatively easy to see the area in front of the luminescent face from the opposite side.
A see-through control layer is provided (directly or via a dielectric layer) between a luminescent layer and a 1 st transparent electrode layer or a 2 nd transparent electrode layer by a method involving, for example, inkjet printing, screen printing, or gravure printing with the use of a colored conductive paste. When a colored conductive paste is used, a see-through control layer is preferably formed in a matrix pattern. Further, a see-through control layer is preferably provided at a location at which it is sandwiched between a 1 st transparent electrode layer and a 2 nd transparent electrode layer. Such colored conductive paste is not particularly limited as long as it has a color that does not cause light reflection or scattering. Examples of a conductive paste that can be used include polymer resin in which silver filler or carbon black has been dispersed and a conductive polymer obtained by doping polymer material such as polyacetylene with halogen material.
In addition, when such colored conductive paste is not used, printing is carried out on the surface of either a 1 st transparent substrate or a 2 nd transparent substrate by inkjet printing, screen printing, gravure printing, or the like with the use of a conventional ink that has a color that does not cause light reflection or scattering. Thus, effects similar to those obtained with the use of a colored conductive paste can be obtained.
The luminescent sheet of the present invention can be produced in the following manner: at least a 1 st transparent electrode layer and a luminescent layer that is pixelated are formed on the above transparent substrate (1 st transparent substrate) that is located in side of an illuminated face such that a 1 st laminate is prepared; at least a 2 nd transparent electrode layer is formed on a 2 nd transparent substrate such that a 2 nd laminate is individually prepared; and the 1 st laminate and the 2 nd laminate are bonded together. When a dielectric layer is provided, it is formed on the luminescent layer of the 1 st laminate, and then the 1 st laminate is joined the 2 nd laminate.
When another see-through control layer is provided, it can be provided by applying a colored conductive paste on the dielectric layer of the 1 st laminate or by carrying out printing on either the 1 st transparent substrate or the 2 nd transparent substrate with an ink having a color that does not cause light reflection or scattering.
In the case of a luminescent sheet produced by patterning method with the use of masking tape or by patterning methods involving screen printing, inkjet printing, gravure printing, or the like, a luminescent layer emits light when a voltage is applied between a 1 st transparent electrode layer and a 2 nd transparent electrode layer. Accordingly, it becomes possible to visually recognize decorative properties that differ from those obtained without luminescence. Further, such decorative properties can be well seen even at night. The above patterning methods may be used in combinations of two or more.
When the aforementioned luminescent layer, the dielectric layer, and the like are formed in a matrix pattern by patterning, light can be emitted from selected pixels of the matrix pattern. In such case, a still image can be displayed while giving an impression similar to that obtained from an animation.
For instance, an example of a method of patterning with the use of masking tape is a method comprising the steps of: forming masking layers between the 1 st transparent substrate and the 1 st transparent electrode layer and between the 1 st transparent electrode layer and the luminescent layer so as to allow at least the luminescent layer and the dielectric layer to be formed in a matrix pattern upon production of the 1 st laminate; and removing the masking layers before allowing the 1 st laminate and the 2 nd laminate together.
Further, printing can be carried out on the luminescent sheet of the present invention in a manner such that decorative effects can be obtained, provided that a transparent part of the luminescent sheet, through which it is possible to see, is remaining. Printing may be carried out either on the illuminated face or on the opposite face of the luminescent sheet, or on both faces. For instance, as shown FIG. 16 , printing can be carried out on both sides of a 1 st transparent substrate 1 and of a 2 nd transparent substrate 7 shown in FIG. 10 . When printing is carried out on the 1 st transparent electrode layer 3 side of a 1 st transparent substrate 1 , printing is carried out before a 1 st transparent electrode layer 3 is provided. In addition, when printing is carried out on the 2 nd transparent electrode layer 8 side of a 2 nd transparent substrate 7 , printing is carried out before a 2 nd transparent electrode layer 8 is provided. Examples of inks that can be used for printing include, but are not particularly limited to, a wide variety of conventional inks. Also, examples of printing methods that can be used include, but are not particularly limited to, conventional printing methods involving screen printing, gravure printing, flexographic printing, inkjet printing, and the like.
In cases in which the luminescent sheet of the present invention that serves as a luminescent decorative material is used as an advertising medium, a decorative medium, or a security sheet that is applied to advertising displays or windows of commercial buildings, vehicles, and the like, such luminescent decorative material can be protected by applying an adhesive sheet (protective adhesive sheet) to both sides thereof. Such protective adhesive sheet to be used is not particularly limited as long as it is transparent. Particularly preferably, an anti-scratch (hard-coating) treatment is carried out on the opposite side of such adhesive sheet against face on which an adhesive is applied. In addition, when such luminescent decorative material is attached to a wall or a window glass, an adhesive is coated to one side of the luminescent decorative material such that the material can be attached to a wall or a window glass.
EXAMPLES
The present invention is hereafter described in greater detail with reference to the following examples, although the technical scope of the present invention is not limited thereto.
Example 1
As shown in FIG. 2 , masking tape 2 (1 cm in width and 20 μm in thickness, Adwill C-902, Lintec Corporation) was applied at 1-cm intervals in a length direction to a polyethylene terephthalate sheet 100 μm in thickness (DIAFOIL T-100, Mitsubishi Polyester Film Corporation) ( FIG. 2 ) serving as a 1 st transparent substrate 1 . Then, a 1 st transparent electrode layer 3 of 100 nm in thickness was formed in stripe pattern by sputtering with ITO ( FIG. 3 ).
Further, masking tape 2 ′ (1 cm in width and 20 μm in thickness) similar to the above masking tape was applied thereto at 1-cm intervals in perpendicular direction ( FIG. 4 ).
Subsequently, a ZnS:Cu solution (FEL-190, Fujikura Kasei Co., Ltd.) was coated thereto using a Mayer bar such that a luminescent layer 4 was formed to have a dried thickness of 40 μm ( FIG. 5 ). Then, masking tape 2 and masking tape 2 ′ were removed therefrom ( FIG. 6 ).
Masking tape 2 (1 cm in width and 20 μm in thickness, Adwill C-902, Lintec Corporation) was applied at 1-cm intervals in perpendicular direction to another polyethylene terephthalate sheet 100 μm in thickness (DIAFOIL T-100, Mitsubishi Polyester Film Corporation) serving as a 2 nd transparent substrate 7 . Then, a 2 nd transparent electrode layer 8 of 100 nm in thickness was formed in stripe pattern by sputtering with ITO. Masking tape 2 was removed therefrom ( FIG. 7 ).
Subsequently, the 2 nd transparent electrode layer 8 was laminated to the luminescent layer 4 ( FIG. 6 ) in a manner such that the stripe pattern of the transparent electrode layers 3 and 8 were orthogonally bonded together ( FIG. 8 ). Drying was carried out using a dryer at 100° C. for 30 minutes. Accordingly, a luminescent sheet was obtained ( FIG. 9 ).
As shown in FIG. 11 , an AC voltage of 100 V with a frequency of 1000 Hz was applied to the thus obtained luminescent sheet in the direction of the sheet's thickness via voltage connection. As a result, the luminescent sheet was confirmed to be excellent in visibility even at night, and furthermore, to have see-through.
Example 2
As shown in FIG. 2 , masking tape 2 (1 cm in width and 20 μm in thickness, Adwill C-902, Lintec Corporation) was applied at 1-cm intervals in a length direction to a polyethylene terephthalate sheet 100 μm in thickness (DIAFOIL T-100, Mitsubishi Polyester Film Corporation) ( FIG. 2 ) serving as a 1 st transparent substrate 1 . Then, a 1 st transparent electrode layer 3 of 100 nm in thickness was formed in stripe pattern by sputtering with ITO ( FIG. 3 ).
Further, masking tape 2 ′ (1 cm in width and 20 μm in thickness) similar to the above masking tape was applied thereto at 1-cm intervals in perpendicular direction ( FIG. 4 ).
Subsequently, a ZnS:Cu solution (FEL-190, Fujikura Kasei Co., Ltd.) was coated thereto using a Mayer bar such that a luminescent layer 4 ( FIG. 5 ) was formed to have a dried thickness of 40 μm. After drying using a dryer at 100° C. for 30 minutes, a barium titanate solution (FEL-615, Fujikura Kasei Co., Ltd.) was further coated thereto such that a dielectric layer 5 ( FIG. 12 ) was formed to have a dried thickness of 30 μm. Drying was carried out using a dryer at 100° C. for 30 minutes as described above.
Thereafter, a conductive paste (FEA-685, Fujikura Kasei Co., Ltd.) was coated to the above dielectric layer 5 such that a see-through control layer 6 was formed to have a thickness of 30 μm ( FIG. 13 ). Then, masking tape 2 and masking tape 2 ′ were removed therefrom ( FIG. 14 ).
Masking tape 2 (1 cm in width and 20 μm in thickness, Adwill C-902, Lintec Corporation) was applied at 1-cm intervals in perpendicular direction to another polyethylene terephthalate sheet 100 μm in thickness (DIAFOIL T-100, Mitsubishi Polyester Film Corporation) serving as a 2 nd transparent substrate 7 . Then, a 2 nd transparent electrode layer 8 of 100 nm in thickness was formed in stripe pattern 100 nm in thickness by sputtering with ITO ( FIG. 7 ). Masking tape 2 was removed therefrom ( FIG. 7 ).
Subsequently, the 2 nd transparent electrode layer 8 was laminated to a see-through control layer 6 ( FIG. 14 ) in a manner such that the stripe pattern of the transparent electrode layers 3 and 8 were orthogonally bonded together ( FIG. 15 ). Thereafter, drying was carried out using a dryer at 100° C. for 30 minutes.
As shown in FIG. 11 , an AC voltage of 100 V with a frequency of 1000 Hz was applied to the thus obtained luminescent sheet in the direction of the sheet's thickness via voltage connection. As a result, the luminescent sheet was confirmed to be excellent in visibility even at night and further to have effects whereby it was possible to see therethrough from one side thereof while it was difficult to see therethrough from the other side thereof.
Example 3
A luminescent sheet was obtained in a manner similar to that used in Example 2, except that printing was carried out on a luminescent layer (ZnS:Cu), a dielectric layer (barium titanate solution), and a see-through control layer (conductive paste) using a screen printing method instead of masking tape.
As shown in FIG. 11 , an AC voltage of 100 V with a frequency of 1000 Hz was applied to the thus obtained luminescent sheet in the direction of the sheet's thickness via voltage connection. As a result, the luminescent sheet was confirmed to be excellent in visibility even at night and further to have effects whereby it was possible to see therethrough from one side thereof while it was difficult to see therethrough from the other side thereof.
Example 4
A luminescent sheet was obtained in a manner similar to that used in Example 2, except that printing was carried out on a luminescent layer (ZnS:Cu), a dielectric layer (barium titanate solution), and a see-through control layer (conductive paste) using an inkjet printing method instead of masking tape.
As shown in FIG. 11 , an AC voltage of 100 V with a frequency of 1000 Hz was applied to the thus obtained luminescent sheet in the direction of the sheet's thickness via voltage connection. As a result, the luminescent sheet was confirmed to be excellent in visibility even at night and further to have effects whereby it was possible to see therethrough from one side thereof while it was difficult to see therethrough from the other side thereof.
Example 5
A luminescent sheet was obtained in a manner similar to that used in Example 2, except that printing was carried out on a luminescent layer (ZnS:Cu), a dielectric layer (barium titanate solution), and a see-through control layer (conductive paste) using a gravure printing method instead of masking tape.
As shown in FIG. 11 , an AC voltage of 100 V with a frequency of 1000 Hz was applied to the thus obtained luminescent sheet in the direction of the sheet's thickness via voltage connection. As a result, the luminescent sheet was confirmed to be excellent in visibility even at night and further to have effects whereby it was possible to see therethrough from one side thereof while it was difficult to see therethrough from the other side thereof.
Example 6
As shown in FIG. 16 , a text was printed on both sides of the luminescent sheet prepared in Example 2 by an inkjet printing method such that a luminescent decorative material was prepared.
As shown in FIG. 11 , an AC voltage of 100 V with a frequency of 1000 Hz was applied to the thus obtained luminescent decorative material in the direction of the sheet's thickness via voltage connection. As a result, the luminescent decorative material was confirmed to have decorative properties, to be excellent in visibility even at night, and further to have effects whereby it was possible to see therethrough from one side thereof while it was difficult to see therethrough from the other side thereof.
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The claimed invention relates to a luminescent decorative material, which is visible even at night, of which different decorative properties are obtained in the daytime or under lighting due to the presence or absence of luminescence. The claimed invention provide a luminescent sheet (plane sheet) having see-through property and containing a transparent part, through which it is possible to see the area behind the plane sheet, and a luminescent part.
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RELATIONSHIP TO OTHER APPLICATIONS
This application is a divisional application of U.S. application Ser. No. 13/438,575, filed Apr. 3, 2012, which application is incorporated by reference for all purposes and from which priority is claimed.
BACKGROUND
Residential wooden stairs are usually purchased as a prefabricated unit with the risers (vertical elements) and the treads (horizontal elements) fastened to stringers in their final form. In the prior art, these prefabricated staircases are installed in, for example a home construction, and construction on a home continues with workmen walking up and down the staircase to perform their construction tasks. Even if the treads (the horizontal surfaces) are covered with a protective material, they can suffer damage during the construction process.
After all major construction in the home is completed, workmen must come in and finish the staircase by sanding the treads and risers and applying appropriate finish coatings to them. If the risers and treads are damaged in any way because of months of foot traffic, the refinishing process takes longer and is more expensive.
BRIEF SUMMARY
Embodiments of the invention to be searched avoid the problem by installing a prefabricated staircase where the risers and treads are not the final materials to be used. Rather the tread is a “sub-tread” and the riser is a “sub-riser” meaning that another surface will be applied on top of the sub-tread and sub-riser in order to finish the staircase.
The present invention solves prior art problems by creating a prefabricated staircase that is “double routed” to allow an initial set of sub-treads and sub-risers to be installed. The purpose of the double routing is to provide additional space for a final capping tread and riser to be installed by inserting the capping riser or tread in the routed space. This provides for a simpler installation process where little to no cutting and or fitting of the final treads and risers (referred to herein as “capping treads” and “capping risers”) is required.
The double routing is made to a depth that permits a capping tread or riser to be inserted into the routed space and shifted to the right or left in a small amount so that the tread remains in the routed space on either side of the staircase. This allows for a finished look without having to butt the final tread and riser up against the side of the stringer that is secured to the sub-risers and sub-treads. Once the capping riser and/or capping tread is in place, it is secured to the sub-riser or sub-tread (as appropriate) via adhesive or mechanical means (or both) known in the art.
This has several advantages. First, a fully functional staircase is installed so that workmen can proceed with finishing the home or structure without having to worry about whether the finished treads or finished risers are being damaged
Second the owner can decide what finish and material to apply to the final tread or riser that is applied over the sub-tread or sub-riser and those capping risers and treads can simply be installed over the sub-tread and sub-riser after all major construction is completed thereby avoid any potential for damage to the capping risers and treads while keeping the stair compliant with appropriate building codes. Other advantages of the various embodiments disclosed herein will be apparent to those of ordinary skill in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a Closed stringer routing used on Boxed and Single Open staircase designs of an embodiment;
FIG. 2 illustrates a finished installation of treads and risers into a double routed stringer;
FIG. 3 illustrates a view of an embodiment having a sub-tread installed in stringers;
FIG. 4 illustrates a view of an embodiment having sub-tread and capping tread installed in stringers;
FIG. 5 illustrates an enlarged view of the finished installation of sub-tread and sub-riser;
FIG. 6 illustrates the final installation of a sub-riser and the capping riser;
FIG. 7 illustrates a side view of an embodiment of an assembled staircase;
FIG. 8 illustrates an embodiment of the routing for sub-risers and sub-treads;
FIG. 9 illustrates an embodiment of the open riser and tread layout; and,
FIG. 10 illustrates an embodiment of a staircase having the double routed channels of differing depths.
DETAILED DESCRIPTION
Referring now to FIG. 1 a closed stringer routing embodiment is illustrated. The stringer 102 forms the main support for a set of stairs. A stringer is the long piece that the stair treads and risers attach to on either side, and which goes diagonally up the wall. In an embodiment, stringer 102 comprises a double-routed channel shown generally as 104 . The double routed space comprises a routed channel wide enough to support a tread and sub-tread (in the horizontal orientation), and a riser and sub-riser (in the vertical orientation) and as further illustrated in FIG. 2 below). The double-routed channel 104 comprises a sub-tread 106 and sub-riser 108 routing areas. Note in this FIG. 1 the illustration is to the routed area. In addition, the double-routed channel 104 further comprises a routing space for a capping tread 110 and a routed space for a capping riser 112 . Additionally, the double-routed channel 104 also comprises sufficient room for the insertion of wedge blocks that, in an embodiment, support the sub-tread and sub-riser. These wedge blocks will be discussed below. The double routed spaces are located on the stringer at varying and in some cases uneven locations that eventually provides for the capping treads and risers to be positioned in the staircase such that applicable building codes are met. Double routing as illustrated herein is accomplished using a model CSR-750CNC Stair Router available from US Concepts although this is not meant as a limitation. Other CNC routers may also be appropriate for the double routing illustrated herein.
FIG. 2 illustrates a finished installation of treads and risers into a double routed stringer. The double-routed channel ( FIG. 1 , 104 ) is illustrated together with a sub-riser 202 , a sub-tread 204 , a capping riser 206 , a capping tread 208 , sub-tread wedge blocking 210 and a sub-riser wedge blocking 212 .
In normal practice of an embodiment, a staircase is constructed using 2 stringers, each of which has double routed channel ( FIG. 1 , 104 ) for risers, sub-risers, treads and sub-treads. However, the staircase is initially constructed as a prefabricated staircase or as a staircase kit which can be field assembled into a unit comprising double routed channels and sub-treads and sub-risers. The application of capping treads and risers occurs later as discussed below.
FIG. 3 illustrates the installation of a sub-tread 302 in stringers 102 A and 102 B. Double-routed channel 104 allows sub-tread 302 to be recessed and secured into each stringer, 102 A and 102 B. Because the double-routed channel 104 is double routed, there is sufficient room left for the placement of a capping tread. Channel spaces for capping treads are illustrated as 304 and 306 . During construction of the staircase, multiple sub-treads are secured into the stringers 102 A, and 102 B in as many steps as necessary to span a particular vertical distance. For purposes of this Figure, a single sub-tread is illustrated.
FIG. 4 illustrates the installation of the capping tread. Once the sub-treads 302 and stringers 102 A and 102 B are assembled, the installation of a capping tread can occur. The capping tread 402 is cut to a length that is less than the full length of sub-tread 302 . This allows the capping tread 402 to be inserted into the remaining open section of the double-routed channel 304 . Because the capping tread is shorter than the full length of sub-tread 302 it can be inserted fully into the double-routed channel for capping-tread 304 to house the capping tread lowered into place and then shifted laterally so that the capping tread is surrounded by and contained in the double routed capping tread channel yet still is embedded in stringers 102 A and 102 B. The capping tread 402 can then be secured to sub-tread 302 with adhesives or fasteners known in the art.
FIG. 5 illustrates an enlarged detail of the final installation of the capping tread 402 and sub-tread 302 . In this illustration stringer 102 A is shown with the double-routed channel 304 (illustrated in phantom) with sub-tread 302 installed into stringer 102 A. Capping tread 402 is shown in its final position where it has been initially inserted into double-routed channel 304 and moved laterally to fit partially into double-routed channel 304 of stringer 102 A and double-routed channel 306 of stringer 102 B (not shown). While this leaves a slight unfilled portion 406 of double routed channel 304 , the capping tread 402 is still completely embedded in and surrounded by stringer 102 A and similarly in stringer 102 B.
FIG. 6 illustrates the final installation of a sub-riser and the capping riser. In this Figure, sub-riser 602 is installed in stringer 102 A in the same manner described above with respect to the sub-treads. Once the staircase is fully fabricated with sub-risers and sub-treads, capping risers and capping treads can be installed. As illustrated in FIG. 6 sub-riser 602 is installed in double routed riser channel 604 . Sub riser 602 is illustrated in horizontal hatching. Capping riser 603 can then be inserted into double routed riser channel 604 and then moved laterally to engage a similar channel in stringer 102 A. Thus, while capping riser 603 does not fully occupy double-routed riser channel 604 it is still surrounded by stringer 102 A and similarly on the opposite side is surrounded by stringer 102 B (not shown).
FIG. 7 illustrates a side view of the assembled staircase of an embodiment. In this embodiment, sub-tread 702 is in place in the double routed tread channel. A capping tread 704 is installed in the double routed tread channel over the top of sub-tread 702 and the combination of sub-tread 702 and capping tread 704 is held in place by tread wedge blocking 712 . Similarly, sub-riser 706 is in place in the double routed channel with capping risers 708 installed on top of sub-riser 706 . The combination of sub-riser 706 and capping riser 708 are held in place by sub-riser wedge block 710 .
FIG. 8 illustrates the routing for sub-risers and sub-treads. Routing channel for sub-riser 806 is illustrated together with the routing channel for capping riser routing channel 802 . Similarly the sub-tread routing 808 is illustrated together with the capping tread routing channel 804 . It should be noted that while capping tread routing channel 804 is shown with a “bullnose” design, this is merely a design choice. The capping tread routing channel 804 may have other edge designs that equally fall within the scope of the various embodiments illustrated herein.
In an embodiment, the first riser of a staircase of the various embodiments illustrated herein will be shorter than other risers in the staircase by an amount equal to the thickness of the first capping tread. That thickness of the capping tread will add to the height of the first step. In order to have all steps of a similar height, it is therefore necessary to have the first riser of the staircase be shorter by the same amount as the thickness of the first capping tread. Thereafter, all riser heights will be the same for subsequent steps in the staircase.
It should be noted that multiple configurations of staircases falling within the various embodiments illustrated herein are possible. For example, and referring to FIG. 9 an open riser and tread layout is illustrated. In this case the floor level stair stringer is set on floor level 906 . However the first sub-riser height 902 will be will be shorter by the same amount as the thickness of the capping tread. Thus for example, and without limitation, in a sample staircase the first riser height would be 7⅜ inches. All successive sub-riser heights 904 will be 8 inches in height. When the first riser 902 has a ⅝ inch thick oak tread installed at the top of the riser, this will make that riser height 8 inches. Thus each step will have the same height. In this fashion the “first staircase step” height will be the combination of the first riser height plus the thickness of the first sub-tread, plus the thickness of the first capping tread.
Referring now to FIG. 10 , a staircase is illustrated having the double routing channels of differing depths. In this embodiment, stringer 1002 comprises double routed channels for sub-treads, sub-risers capping treads and capping risers. It should be noted that it is not a requirement that the depth of the routed channels be the same. For example sub-riser channel 1008 may, in an embodiment, be ½ inch deep. Similarly the sub-tread channel 1010 may also be ½ inch deep. However in this embodiment, the capping riser channel 1006 may only be ¼ inch deep. Similarly the capping tread channel 1004 may also be only ¼ inch deep. Other combinations of channel depths are also considered to be within the scope of the various embodiments disclosed herein.
A method for creating and building a staircase has been described. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the scope of the invention disclosed and that the examples and embodiments described herein are in all respects illustrative and not restrictive. Those skilled in the art of the embodiments illustrated herein will recognize that other embodiments using the concepts described herein are also possible. Further, any reference to claim elements in the singular, for example, using the articles “a,” “an,” or “the” is not to be construed as limiting the element to the singular.
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A staircase and method for producing the same. The staircase is produced by double routing channels for sub-treads and sub-risers and capping risers and capping treads. These sub-treads and sub-risers are assembled into staircase stringers that have pre-routed channels that are sufficient to install sub-treads and sub-risers having a particular thickness and having room for subsequent placement or installation of capping treads and risers by sliding them laterally into the channels created by the double routing of the stringers. This creates a more finished look to be (the) staircase while avoiding damages to the capping treads and risers that might occur during building construction.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/030,111, filed on Feb. 20, 2008, which is hereby incorporated in its entirety herein by reference.
FIELD
[0002] The invention relates generally to a multiple speed transmission having a plurality of planetary gear sets and a plurality of torque transmitting devices and more particularly to a transmission configured for a front wheel drive vehicle having eight or more speeds, four planetary gear sets and a plurality of torque transmitting devices.
BACKGROUND
[0003] The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
[0004] A typical multiple speed transmission uses a combination of a plurality of torque transmitting mechanisms, planetary gear arrangements and fixed interconnections to achieve a plurality of gear ratios. The number and physical arrangement of the planetary gear sets, generally, are dictated by packaging, cost and desired speed ratios.
[0005] While current transmissions achieve their intended purpose, the need for new and improved transmission configurations which exhibit improved performance, especially from the standpoints of efficiency, responsiveness and smoothness and improved packaging, primarily reduced size and weight, is essentially constant. Accordingly, there is a need for an improved, cost-effective, compact multiple speed transmission.
SUMMARY
[0006] In one aspect of the present invention, a transaxle is provided having a transmission input member, a transmission output member, a plurality of planetary gear sets, and a plurality of torque-transmitting mechanisms.
[0007] In another aspect of the present invention, a housing having a first wall, a second wall and a third wall extending between the first and second walls is provided. The first, second, third and fourth planetary gear sets are disposed within the housing. The second planetary gear set is adjacent the first wall, the third planetary gear set is adjacent second wall, the first planetary gear set is adjacent the second planetary gear set and the fourth planetary gear set is between the first and third planetary gear sets.
[0008] In yet another aspect of the present invention, each planetary gear set has a sun gear member, a ring gear member, and a planet carrier member supporting a plurality of planet gears each configured to intermesh with both the sun gear member and the ring gear member. The ring gear member of the first planetary gear set is permanently coupled to the sun gear member of the second planetary gear set, the sun gear member of the first planetary gear set is permanently coupled to the sun gear member of the fourth planetary gear set, the ring gear member of the third planetary gear set is permanently coupled to the planet carrier member of the fourth planetary gear set.
[0009] In yet another aspect of the present invention, the output member is permanently coupled with the carrier members of the second and third planetary gear sets. The input member is permanently coupled with the carrier member of the first planetary gear set.
[0010] In yet another aspect of the present invention, the housing has a first area defined radially inward from an outer periphery of the planetary gear sets and axially bounded by the first wall and the second planetary gear set. A second area is defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the first and second planetary gear sets. A third area is defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the first and fourth planetary gear sets. A fourth area is defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the third and fourth planetary gear set. A fifth area is defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the third planetary gear set and the second wall. A sixth area is defined radially inward from the third wall and radially outward from the outer periphery of the planetary gear sets and axially bounded by the first wall and the second wall.
[0011] In yet another aspect of the present invention, the first clutch is disposed in at least one of the first, second and sixth areas and is selectively engageable to interconnect the ring gear member of the first planetary gear set with the sun gear member of the third planetary gear set.
[0012] In yet another aspect of the present invention, a second clutch is disposed in at least one of the first, second and sixth areas and is selectively engageable to interconnect the planet carrier member of the first planetary gear set with the sun gear member of the third planetary gear set.
[0013] In yet another aspect of the present invention, a third clutch is disposed in at least one of the first, second and sixth areas and is selectively engageable to interconnect the ring gear member of the second planetary gear set with the sun gear member of the third planetary gear set.
[0014] In yet another aspect of the present invention, a first brake is disposed in at least one of the first, third, fifth and sixth areas and is selectively engageable to interconnect the sun gear member of the first planetary gear set and the sun gear member of the fourth planetary gear set to the housing.
[0015] In yet another aspect of the present invention, a second brake is disposed in at least one of the first, fifth and sixth areas and is selectively engageable to interconnect the ring gear member of the fourth planetary gear set to the housing.
[0016] In still another aspect of the present invention, the clutches and the brakes are selectively engageable to establish at least eight forward speed ratios and at least one reverse speed ratio between the transmission input member and the transmission output member.
[0017] In still another aspect of the present invention, a power transfer assembly has a first and a second transfer gear and a power transfer member. The first transfer gear is rotatably fixed to the engine output member and the second transfer gear is rotatably fixed to the transmission input member. The power transfer member is rotatably coupled to the first and second transfer gears for transferring rotational energy from the first transfer gear to the second transfer gear.
[0018] In still another aspect of the present invention, a final drive planetary gear set has a final drive sun gear coupled to the transmission output member, a final drive ring gear coupled to the transmission housing and a final drive carrier member rotatably supporting a final drive plurality of pinion gears intermeshed with both the final drive sun gear and the final drive ring gear.
[0019] In still another aspect of the present invention, a differential gear set having a differential housing coupled to the final drive carrier member and has a pair of gears rotatably supported in the differential housing. One of the pair of the gears is rotatably fixed to one of a pair of road wheels and the other of the pair of the gears is rotatably fixed to the other one of the pair of road wheels.
[0020] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0021] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
[0022] FIG. 1A is a schematic diagram of a gear arrangement for a front wheel drive transmission, according to the principles of the present invention;
[0023] FIG. 1B is a chart showing the locations of the torque transmitting devices for the arrangement of planetary gear sets of the transmission shown in FIG. 1A , in accordance with the embodiments of the present invention; and
[0024] FIG. 2 is a schematic diagram of a front wheel drive transaxle arrangement incorporating the gear arrangement of the transmission of FIG. 1A and FIG. 1B , according to the principles of the present invention.
DETAILED DESCRIPTION
[0025] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.
[0026] Referring now to FIG. 1A , an embodiment of a front wheel drive multi-speed or eight speed transmission is generally indicated by reference number 10 . The transmission 10 is illustrated as a front wheel drive or transverse transmission, though various other types of transmission configurations may be employed. The transmission 10 includes a transmission housing 12 , an input shaft or member 14 , an output shaft or member 16 and a gear arrangement 18 . The input member 14 is continuously connected to an engine (shown in FIG. 2 ) or to a turbine of a torque converter (not shown). The output member 16 is continuously connected with a final drive unit (not shown) or transfer case (shown in FIG. 2 ).
[0027] The gear arrangement 18 of transmission 10 includes a first planetary gear set 20 , a second planetary gear set 22 , a third planetary gear set 24 , and a fourth planetary gear set 26 . The planetary gear sets 20 , 22 , 24 and 26 are connected between the input member 14 and the output member 16 .
[0028] In a preferred embodiment of the present invention, the planetary gear set 20 includes a ring gear member 20 A, a planet carrier member 20 B that rotatably supports a set of planet or pinion gears 20 D (only one of which is shown) and a sun gear member 20 C. The ring gear member 20 A is connected for common rotation with a first shaft or intermediate member 42 . The planet carrier member 20 B is connected for common rotation with input shaft or member 14 . The sun gear member 20 C is connected for common rotation with a second shaft or intermediate member 44 . The pinion gears 20 D are each configured to intermesh with both the sun gear member 20 C and the ring gear member 20 A.
[0029] The planetary gear set 22 includes a ring gear member 22 A, a planet carrier member 22 B that rotatably supports a set of planet or pinion gears 22 D and a sun gear member 22 C. The ring gear member 22 A is connected for common rotation with a third shaft or intermediate member 46 . The planet carrier member 22 B is connected for common rotation with a fourth shaft or intermediate member 48 . The sun gear member 22 C is connected for common rotation with the first shaft or intermediate member 42 . The pinion gears 22 D are each configured to intermesh with both the sun gear member 22 C and the ring gear member 22 A.
[0030] The planetary gear set 24 includes a ring gear member 24 A, a planet carrier member 24 B that rotatably supports a set of planet or pinion gears 24 D and a sun gear member 24 C. The ring gear member 24 A is connected for common rotation with a fifth shaft or intermediate member 50 . The planet carrier member 24 B is connected for common rotation with the output shaft or member 16 and with fourth shaft or intermediate member 48 . The sun gear member 24 C is connected for common rotation with the sixth shaft or intermediate member 52 . The pinion gears 24 D are each configured to intermesh with both the sun gear member 24 C and the ring gear member 24 A.
[0031] The planetary gear set 26 includes a ring gear member 26 A, a carrier member 26 B that rotatably supports a set of planet or pinion gears 26 D and a sun gear member 26 C. The ring gear member 26 A is connected for common rotation with a seventh shaft or intermediate member 54 . The planet carrier member 26 B is connected for common rotation with the fifth shaft or intermediate member 50 . The sun gear member 26 C is connected for common rotation with the second shaft or intermediate member 44 . The pinion gears 26 D are each configured to intermesh with both the sun gear member 26 C and the ring gear member 26 A.
[0032] The transmission 10 also includes a plurality of torque-transmitting mechanisms or devices including a first clutch 66 , a second clutch 68 , a third clutch 70 , a first brake 72 and a second brake 74 . The first clutch 66 is selectively engagable to connect the first shaft or intermediate member 42 to the sixth shaft or intermediate member 52 . The second clutch 68 is selectively engagable to connect the input shaft or member 14 to the sixth shaft or intermediate member 52 . The third clutch 70 is selectively engagable to connect the third member or intermediate member 46 to the sixth shaft or intermediate member 52 . The first brake 72 is selectively engagable to connect the second shaft or intermediate member 44 to the transmission housing 12 to restrict rotation of the member 44 relative to the transmission housing 12 . Finally, the second brake 74 is selectively engagable to connect the seventh shaft or intermediate member 54 to the transmission housing 12 to restrict rotation of the member 54 relative to the transmission housing 12 .
[0033] The transmission 10 is capable of transmitting torque from the input shaft or member 14 to the output shaft or member 16 in at least eight forward torque ratios and one reverse torque ratio. Each of the forward torque ratios and the reverse torque ratio are attained by engagement of one or more of the torque-transmitting mechanisms (i.e. first clutch 66 , second clutch 68 , third clutch 70 , first brake 72 and second brake 74 ). Those skilled in the art will readily understand that a different speed ratio is associated with each torque ratio. Thus, eight forward speed ratios may be attained by the transmission 10 .
[0034] The transmission housing 12 includes a first wall or structural member 102 , a second wall or structural member 104 and a third wall or structural member 106 . The third wall 106 interconnects the first and second walls 102 and 104 to define a space or cavity 110 . Input shaft or member 14 is supported by the first wall 102 by bearings 112 . Output shaft or member 16 is supported by the second wall 104 by bearings 114 . The planetary gear sets 20 , 22 , 24 and 26 and the torque-transmitting mechanisms 66 , 68 , 70 , 72 and 74 are disposed within cavity 110 . Further, cavity 110 has a plurality of areas or zones A, B, C, D, E, and F in which the plurality of torque transmitting mechanisms 66 , 68 , 70 , 72 and 74 will be specifically positioned or mounted, in accordance with the preferred embodiments of the present invention.
[0035] As shown in FIG. 1A , zone A is defined by the area or space bounded by: the first wall 102 , planetary gear set 22 , radially inward by a reference line “L” which is a longitudinal line that is axially aligned with the input shaft 14 , and radially outward by a reference line “M” which is a longitudinal line that extends adjacent an outer diameter or outer periphery of the planetary gear sets 20 , 22 , 24 and 26 . While reference line “M” is illustrated as a straight line throughout the several views, it should be appreciated that reference line “M” follows the outer periphery of the planetary gear sets 20 , 22 , 24 and 26 , and accordingly may be stepped or non-linear depending on the location of the outer periphery of each of the planetary gear sets 20 , 22 , 24 and 26 . Zone B is defined by the area bounded by: planetary gear set 22 , the planetary gear set 20 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone C is defined by the area bounded by: the planetary gear set 20 , the planetary gear set 26 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone D is defined by the area bounded by: the planetary gear set 24 , the planetary gear set 26 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone E is defined by the area bounded by: the planetary gear set 24 , the second end wall 104 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone F is defined by the area bounded by: the first wall 102 , the second wall 104 , radially inward by reference line “M” and radially outward by the third wall 106 .
[0036] In the gear arrangement 18 of transmission 10 shown in FIG. 1A , the planetary gear set 22 is disposed closest to the first wall 102 , the planetary gear set 24 is disposed closest to the second wall 104 , the planetary gear set 20 is disposed adjacent the planetary gear set 22 , and the planetary gear set 26 is disposed between the planetary gear sets 20 and 24 . The torque-transmitting mechanisms are intentionally located within specific Zones in order to provide advantages in overall transmission size, packaging efficiency, and reduced manufacturing complexity. In the particular example shown in FIG. 1A , the first and second clutches 66 and 68 and the first and second brakes 72 and 74 are disposed within Zone F and the third clutch 70 is disposed within Zone A.
[0037] However, the present invention contemplates other embodiments where the torque-transmitting mechanisms 66 , 68 , 70 , 72 and 74 are disposed in the other Zones. The feasible locations of the torque-transmitting mechanisms 66 , 68 , 70 , 72 and 74 within the Zones are shown in the chart of FIG. 1B . The chart of FIG. 1B lists clutches and brakes in the left most column and the available zones to locate the clutch/brake in the top row. An “X” in the chart indicates that the present invention contemplates locating the clutch or brake in the zone listed in the top row. For example, first brake 72 may be located in zones A, C, E or F, second brake 74 may be located in zones A, E or F, first clutch 66 may be located in zones A, B or F, second clutch 68 may be located in zones A, B or F and third clutch 70 may be located in zones A, B or F.
[0038] Referring now to FIG. 2 , a front wheel drive powertrain 150 incorporating a transaxle 154 is illustrated, in accordance with the embodiments of the present invention. Transaxle 154 includes the transmission 10 having the gear arrangement 18 of FIGS. 1A and 1B . Transaxle 154 is mounted to an engine 156 . Engine 156 produces a driving torque in an engine output shaft 157 that drives the input shaft 14 of transmission 10 , as described below. Engine 156 is generally an internal combustion engine, however, the present invention contemplates other types of engines such as electric and hybrid engines. Further, transaxle 154 includes a transfer chain or belt 158 , a drive sprocket or gear 160 , a driven sprocket or gear 162 , a differential 164 , a final drive planetary gear set 166 and a pair of drive axles 168 and 170 that drive a pair of road wheels 172 and 174 , respectively.
[0039] Transfer chain or belt 158 engages, at a first end 180 , drive sprocket or gear 160 and at a second end 182 the driven sprocket or gear 162 . The drive sprocket or gear 160 is coupled to engine output shaft or member 157 . Driven sprocket 162 is rotatably fixed to a drive shaft or rotatable member 159 . Drive shaft or rotatable member 159 is coupled to the input shaft 14 of transmission 10 . The output shaft 16 of transmission 10 is connected to an output sleeve shaft 163 . Output sleeve shaft 163 is coupled to a sun gear of a final drive planetary gear set 166 to achieve the desired gear ratio. A carrier member of final drive planetary gear set 166 supports a plurality of pinion gears which mesh with both the sun gear and a ring gear of final drive planetary gear set 166 . The carrier member of final drive planetary gear set 166 is rotatably coupled to and transfers driving torque to a housing of the differential 164 . Differential 164 transfers the driving torque generated by engine 156 to the two drive axles 168 and 170 through two sets of bevel gears rotationally supported in the differential housing. Drive axles 168 and 170 are rotatably fixed to and independently driven by the bevel gears of the differential 164 to supply the driving torque to the vehicle road wheels 172 and 174 .
[0040] The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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A front wheel drive transmission is provided having an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes a sun gear member, a planet carrier member, and a ring gear member. The torque transmitting devices include clutches and brakes arranged within a transmission housing.
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RELATED APPLICATIONS
[0001] This application, pursuant to 37 C.F.R. 1.78(c), claims priority based on U.S. provisional application Ser. No. 60/452,700 filed on Mar. 6, 2003.
CONTRACTUAL ORIGIN OF THE INVENTION
[[0002]] The United States Government has rights in this invention pursuant to Contract No. W-31-109-ENG-38 between the U.S. Department of Energy (DOE) and The University of Chicago representing Argonne National Laboratory.
BACKGROUND OF THE INVENTION
[0003] Electrodeionization (EDI) is best known as a desalting process for dilute aqueous streams. Its commercial application has been limited to the production of ultra-pure water mainly for semiconductor and pharmaceutical industries. EDI technology based on a fixed resin-wafer has been disclosed in U.S. Pat. No. 6,495,014, the entire disclosure of which is incorporated by reference. Further disclosures of related EDI technology are in U.S. patent application Ser. No. 10/213,721 filed Aug. 6, 2002 entitled “ELECTRODEIONIZATION METHOD” and U.S. patent application Ser. No. 10/702,798 filed Nov. 5, 2003 entitled “IMMOBILIZED BIOCATALYTIC ENZYMES IN ELECTRODEIONIZATION (EDI)”, the entire disclosures of which are incorporated by reference. This technology was originally developed for desalting industrial dextrose streams but its use can be extended to the application of EDI in the fields of chemical production, separation, and purification.
[0004] Organic esters, such as ethyl lactate, are attractive substitutes for many traditional solvents that are generally considered to be toxic. For this description, ethyl lactate is used as an example of a class of organic acid esters that are derived from the reaction of small alcohols such as methyl, ethyl, propyl, butyl, etc. with organic acids such as acetic, lactic, propionic, 3-hydroxy-propionic, butyric, etc. Ethyl lactate is a biodegradable chemical that has equivalent or superior solvent properties compared to many petroleum-based solvents. It is manufactured by esterification, i.e., reaction of ethanol and lactic acid. Although lactic acid is produced by fermentation, the acid is neutralized to the lactate salt to prevent media acidification and inhibition of biocatalytic activity. Therefore, the lactate salt must be converted back to lactic acid and the acid must be recovered and purified before esterification. The salt conversion and subsequent acid recovery can be the highest cost in the entire ester process, and is the greatest economic barrier to increased ethyl lactate production and utilization.
[0005] Various methods have been implemented or proposed to convert the salt to lactic acid. The utility of these methods can be affected by the type of base that is used to neutralize the lactic acid. The conventional approach uses hydrated lime for neutralization to form calcium lactate salt. Following fermentation the broth is acidified with sulfuric acid, which produces calcium sulfate and lactic acid. Calcium sulfate, which is only slightly soluble, precipitates during the acidification step and is removed from the broth by filtration. Although simple, this approach requires the addition of acid and produces nearly one pound of waste calcium sulfate for every pound of lactic acid that is produced.
[0006] Another approach uses sodium hydroxide or bicarbonate as the base for neutralization and a double electrodialysis process to concentrate the sodium lactate salt by desalting electrodialysis (DSED) and to split the salt into sodium hydroxide and lactic acid by water-splitting electrodialysis (WSED); the sodium hydroxide can then be recycled back to the fermentor. This approach is somewhat more economical than the conventional process because the DSED and WSED processes purify the lactate, as well as convert and separate it from the broth, and produce much less chemical waste. The DSED and WSED systems and membranes, however, represent significant capital and operating costs.
[0007] Yet another approach, referred to as direct esterification, uses ammonium hydroxide to neutralize the acid in the fermentor, DSED to concentrate and purify the ammonium lactate salt, and a pervaporation-assisted reactor to “thermally crack” ammonia gas from the ammonium lactate and remove it from the broth and to simultaneously carry out the esterification reaction. The primary difficulty with this approach is that ammonia and ethyl lactate can react irreversibly to produce lactamide that has no significant value and substantially reduces the ethyl lactate yield.
SUMMARY OF THE INVENTION
[0008] Based on the EDI concept and its capability of in-situ acidification, a new process has been discovered that converts the EDI system into a solid-phase acid/base catalytic reactor for chemicals produced from acid/base catalytic reactions. The ion-exchange resin beads in the EDI act as solid-phase acid/base catalysts and the ionic reactants and/or products are separated, in-situ, from each other by the applied electric field. This invention, in part relates to using the catalytic EDI separative reactor (CEDISR) to produce an organic ester. The invention combines, in one particular aspect, the separation of charged cation salt carboxylate substrates with an acid/base catalyzed alcohol esterification reaction. The reactor utilizes a fixed resin-wafer and electrodeionization (EDI) technology to form a separative reactor that carries out the separation and reaction in a single stage process.
[0009] It is an important object of the present invention to provide a method and apparatus for a single step esterification in an EDI stack.
[0010] Another object of the present invention to provide a method of continuously making an organic ester from a lower alcohol and an organic acid, comprising, introducing an organic acid or an organic salt into and/or producing an organic acid or an organic salt in an electrodeionization (EDI) stack having an anode and a cathode and a plurality of reaction chambers each formed from a porous solid ion exchange resin wafer interleaved between anion exchange membranes or an anion exchange membrane and a cation exchange membrane or an anion exchange membrane and a bipolar exchange membrane, providing mechanism for establishing an electric potential between the EDI anode and cathode, wherein at least one reaction chamber are esterification chambers and/or bioreactor chambers and/or chambers containing an organic acid or salt, whereby an organic acid or organic salt present in the EDI stack disassociates into a cation and an anion with the anion migrating into an associated esterification chamber through an anion exchange membrane if required and reacting with a lower alcohol in the esterification chamber to form an organic ester and water with at least some of the water splitting into a portion and a hydroxyl anion with at least some of the hydroxyl anion migrating to an adjacent chamber, said migration of ions being facilitated by establishing an electric potential across the EDI anode and cathode.
[0011] A still further object of the present invention is to provide an apparatus for manufacturing an organic ester, comprising an electrodeionization (EDI) stack having an anode and a cathode and a plurality of reaction chambers each formed from a porous solid ion exchange resin wafer interleaved between anion exchange membranes or an anion exchange membrane and either a cation exchange membrane or a bipolar membrane, mechanism for establishing an electrical potential between said EDI anode and said cathode, at least some of said reaction chambers being esterification chambers or esterification chambers separated from an adjacent bioreactor chamber by an anion exchange membrane and/or an acid/base capture chamber, said bioreactor chambers each containing an ion exchange resin wafer capable of forming an organic acid or salt from an ionizable fluid flowing therein, said esterification chambers each containing an ion exchange resin capable of forming an organic ester and wafer from a lower alcohol and an anion of the organic acid or salt, a source of anions supplied directly to said esterification chambers or supplied from adjacent chambers, and a supply of lower alcohol to said esterification chambers, whereby when a potential is established across said EDI anode and cathode at least some hydroxyl anions in said esterification chambers from water splitting migrate across anion exchange membranes to adjacent chambers to drive the reaction to continuously produce an organic ester.
[0012] The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic illustration of an acid/base catalytic esterification in reactor using an EDI stack;
[0014] FIG. 2 is a schematic illustration of a two stage esterification process in an EDI stack;
[0015] FIG. 3 is a schematic illustration of the combined separative bioreactor/catalytic reactor using three compartment EDI stack;
[0016] FIG. 4 is a schematic illustration of the combined separative bioreactor/catalytic reactor using two compartment EDI with a bipolar membrane;
[0017] FIG. 5 is a graphical representation of the relationship between esterification and time for various conditions;
[0018] FIG. 6 is a graphical representation of the relationship between the concentration of ethyl lactate in the product as a function of time using a apparatus of the present invention;
[0019] FIG. 7 is a graphical representation of the relationship between the water content in the product and the ester concentration in the product s a function of time for a two-chamber EDI set-up; and
[0020] FIG. 8 is a graphical representation of the relationship between the water content in the product and the ester concentration in the product as a function of time for a three-chamber set-up.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] A “single-stage esterification” that reacts the ethanol with the lactate salt to form ethyl lactate, therefore, provides both economic and process advantages. We used the CEDISR design to perform a single-stage esterification for organic ester production. The use of ion exchange resins to catalyze esterification has been reported in the literature, Walkup, Paul C. et. al., “ Production of Esters of Lactic Acid, Esters of Acrylic Acid, Lactic Acid and Acrylic Acid ”, PCT/US91/00403, 1991. However, this invention is the first use of ion-exchange resin in an EDI configuration for simultaneous catalysis, from acid to ester form, and subsequent separation.
[0022] A “three-compartment” or three-chamber EDI configuration (see FIG. 2 ) is utilized to carry out the two-stage esterification. In the three-compartment EDI configuration, the fermentation broth, for example only containing lactate salt (e.g., sodium or ammonia lactate) or lactic acid and pure ethanol for example only are fed to the feed compartment and product compartment respectively. The counter cations (e.g., Na + or NH 4 + ) are transported from the feed compartment to the base compartment or chamber. The lactate ions are transported to the product compartment or chamber that contains the cation and anion mixing resin wafer. These lactate ions react with ethanol to form ethyl lactate. Hereafter, chamber and compartment are used interchangeably and specific examples used are for purposes of illustration only and do not limit the invention.
[0023] The lactate ions are transported under the applied electric field from the feed chamber via the ion-exchange membrane to the reaction chamber and adsorb in the ion exchange resin. The ion exchange resin matrix provides the necessary conductive media for the lactate to move in the reaction chamber for esterification. Furthermore, esterification at the resin/liquid interface is enhanced by localized water splitting reaction of the ion exchange resins. The water in the reaction chamber is produced by the esterification reaction as well as leakage from experimental equipment. Water splitting (WS) is a well-known phenomenon in the EDI process that produces protons and hydroxyl ions moved due to the applied electric field. The hydroxyl ion from water splitting exchanges with the lactate ion adsorbed in the anion resin. Thus, the released lactate ion forms lactic acid with the proton from water splitting in the solution adjacent to the resin beads. The water splitting occurring either on the resin beads or on the surface of suitable ion-exchange membranes, such as a bipolar membrane, also provides excess protons to catalyze the esterification reaction. This electrical acidification is a major advantage and novel discovery in this process. The water produced from the esterification provides the water source for the water splitting reaction that produces an excess of protons (hydrogen ions) in the esterification chamber for catalyzing the further esterification as well as regenerating the cation resin. Consequently, increasing the water splitting rate by adjusting the applied current also accelerates the rate of ester production in the bulk fluid. (see FIG. 2 ) The excess hydroxyl ions produced by the water splitting are transported, via the anion resin, to the base compartment also known as an acid/base capture chamber, see FIG. 3 . Therefore, in theory, no water accumulates in the product compartment and, thus, the hydrolysis of organic ester back to the starting, acid and alcohol is minimized or eliminated. This results in a high conversion yield of organic acid to organic ester.
[0024] The three-compartment EDI process eliminates the needed for purification and concentration of the lactic salt from the fermentation broth in conventional processes, which are energy intensive and significantly impact the overall cost of producing the product. With simple pre-filtration of the suspensions in the feed solution that is well known in the art, the fermentation broth can be directly fed into the three-compartment EDI for single-stage separation and esterification to produce organic ester, see FIG. 1 . This invention reduces several processing steps from the traditional ester production scheme.
[0025] Another embodiment of the invention that further simplifies the process steps in producing the organic ester is to combine a EDI separative bioreactor (EDISB) with the CEDISR. In this process, either “three-compartment” or “two-compartment” EDI configurations are useful. FIG. 3 shows the configuration of the three-compartments EDI. As seen from the flow chart in FIG. 3 , the esterification chamber is sandwiched by a substrate (bioreactor) chamber and an acid/base capture chamber. Both the substrate and esterification chambers have resin wafers therein, as described in the patent and patent applications referenced above and incorporated therein. The substrate compartment (bioreactor) is used to perform the biological reaction to produce the organic acid. The ionic organic salt is immediately transported as it is produced into the esterification compartment where pure ethanol is fed. At the same time, the proton in the bioreactor migrates or is will transported through a cation membrane into the acid/base capture compartment. Thus, the immediate removal of the produced organic acid benefits the biological reaction by avoiding the product inhibition as well as maintaining the optimal pH condition without buffers. The captured pure ionic organic in the esterification compartment performs esterification catalyzed by the cation resin. The water produced from the esterification is consumed to regenerate the ion exchange resin via the WS reaction. The hydroxyl ions generated from water splitting is transported through the anion-exchange membrane into the acid/base capture compartment and reacts with protons (i.e., traveling from the bioreactor compartment) to form water.
[0026] The three-compartments combined separative biological/catalytic reactor (CSBCR) EDI can be converted into two-compartments EDI if it is needed. Using the esterification as the example, the acid/base capture compartment can be replaced by a bipolar ion-exchange membrane as shown in FIG. 4 . Again, both two compartments have ion exchange resins therein. In this cell arrangement, the only ionic species forced to cross the ion-exchange membrane is the ionic organic salt generated in the substrate compartment (i.e., bioreactor). The proton in the substrate compartment is neutralized by the hydroxide ion generated on anion side of the bipolar membrane. The cation catalyst in the esterification compartment is regenerated by the proton produced by the cation side of bipolar membrane (i.e., via water splitting in the bipolar membrane). While both embodiments can be used as CSBCR, because of the hydrophilic property of bipolar membranes, the two-compartment EDI may cause more water to be transported into the catalytic rector compartment compared to the three-compartment design.
EXAMPLE 1
[0027] Three experiments are carried out to demonstrate the single-stage catalytic reactor of the esterification process, see FIG. 1 . In the first two experiments, 1.35 mole percent of lactic acid or 0.83 mole percent of sodium lactate in ethanol with 2.5 g of cation-exchange resin ®DOWEX DR2030 (from Dow Chemical Inc.) are placed into two reactors respectively. The third experiment uses a reactor containing 1.35 mole percent of lactic acid in ethanol without the presence of a cation-exchange resin. The initial water content in the reactors is in the range of 3.5-3.6 mole percent. All the reactors are operated at 50° C. FIG. 5 shows the conversion of lactate to ester. Sodium lactate has a greater rate of conversion to the ester as compared with lactic acid in alcohol during the same period of operation. Sodium lactate which is more easily ionized to lactate ion shows more favorable esterification. The more limited amount of ionic lactate with the lactic acid solution appears to limit the esterification reaction. Without the addition of cation-exchange resins, the esterification reaction is two-orders of magnitude lower.
[0028] The results demonstrate that ionization of organic anion plays an important role in esterification. It also suggests that the use of EDI to extract the ionized organic anion and simultaneously perform esterification is a kinetically favorable process.
EXAMPLE 2
[0029] Similar to the configuration showed in FIG. 2 , a “three-compartment” EDI stack used to produce the ethyl lactate. An ED stack (Tokuyama Inc., model TS-2) filled with an immobilized resin wafer containing ®C100E (cation resin bead) and ®A444 (anion resin bead) ion-exchange resins (from Purolite Company) was used as the EDI device. ®AMH (anion permeable) and ®C6610F (cation permeable) ion exchange membranes (from Tokuyama Inc.) were used in the stack. The membrane surface area was 195 cm 2 . A feed of 10% sodium lactate was re-circulated in the feed compartment (i.e., compartment 1 in FIG. 2 ). Pure ethanol was fed into the product compartment (compartment 2 ). Sodium hydroxide was recovered from the base compartment (compartment 3 ). The operating temperature was maintained around 35° C. FIG. 6 shows the production of ester obtained in the production compartment using this EDI stack. 4-6 wt. % of water was found in the product compartment which we attributed to diffusion through the membrane from the feed into the product compartment. The power consumption was around 0.1-0.2 kWh/lb of ethyl lactate produced. The power consumption for the single-stage EDI process is much lower than the estimated 1.1 kWh/lb and 0.9 kWh/lb of ethyl lactate produced, observed for production of ester using the double ED process and direct esterification process, respectively.
EXAMPLE 3
[0030] The same EDI stack as described in Example 2 was used, see FIG. 4 . The ion-exchange membranes used in the stack were a bipolar membrane (®BP-1) and anion-exchange membrane (AMH) purchased from Tokuyama Inc. 1% sodium lactate was used to simulate the organic acid production in the substrate compartment. Pure ethanol was used in the esterification compartment. The operation temperature was maintained at 30° C. FIG. 7 shows the ester production and water content in the product. The high water content diffused from the substrate compartment eventually re-hydrated the ester after 1400 minutes operation.
EXAMPLE 4
[0031] In this Experiment, ®Amberlite 15 (from Rohm & Haas Inc.) cation exchange resin wafer was used in the esterification compartment. ®AMH (anion permeable) and ®C6610F (cation permeable) ion-exchange membranes were used in the EDI stack, as seen in FIG. 3 . A mini-stack of electrodialysis (from ElectroCell AB Inc.) with 10 cm 2 membrane area was used. 1% sodium lactate was used to simulate the organic acid salt in the substrate compartment. The stack was operated about 25° C. FIG. 8 shows the water content and ester production. Table 1 lists the results of water, ethanol, lactate and ester in the esterification compartment. No re-hydration of ester was observed. The water in the product did not retard the esterification as was indicated by steadily increasing ester productivity and esterification conversion.
TABLE 1 Time Product Product Product Product Esterification Concentration Productivity Water Water Water Elapse Current Ester Water Lactate Ethanol conversion equilibrium Ester Content Transport rate Splitting (minute) (A) (mg/L) (g/L) (mg/L) (g/L) (%) constant (mg/L/hour) (wt. %) (g/L/hour) (%) 0.00 0.0 29.8 16.2 780 0 3.68% 1.965 90.0 0.014 16.2 31.6 121.6 779 10 0.01 10.8 3.90% 1.868 47.6 250.0 0.014 89.3 36.4 211.1 775 25 0.04 21.4 4.48% 1.852 59.2 340.0 0.014 146.2 39.0 276.2 773 30 0.05 25.8 4.80% 1.842 58.7 435.0 0.014 292.5 39.5 357.5 772 40 0.08 40.4 4.86% 1.703 52.1
[0032] Diffusion of water through the ion-exchange membranes may limit the extent of the esterification reaction due to subsequent hydrolysis of the ester. An additional pervaporation operation of the product stream from the single-stage EDI device to extract the diffusion water in the product stream (i.e., the ethanol and ester) can be utilized to reduce the accumulation of water. Another embodiment is to use hydrophobic membranes to limit the amount of water that is transported across the membrane by diffusion. These commercially-available membranes also allow the system to operate at higher temperatures, which increase the rates of ion transport and esterification reaction and increase the solution conductivity, all of which are beneficial.
[0033] Water produced as a product of the esterification reaction can be removed by adjusting the stack current so as to maximize the removal of water from the esterification chamber by water splitting. Toward this, increasing resin wafer thickness improves distribution of water splitting along the length of the resin wafer. Good water splitting distribution is also important to continually regenerate the full length of the resin wafer.
[0034] The ratio of anion to cation exchange capacity in the wafer may also have a strong influence on the efficiency of the process. For example, wafers with a high cation to anion contact protons that have been adsorbed at a cation exchange site. Conversely, the reaction rate may be enhanced when protons in solution contact lactate anions that have been adsorbed on an anion exchange site.
[0035] Conductivity in the esterification plays important role in the inventive process. Pure alcohol has very low conductivity causing inefficient organic acid transport from the bioreactor compartment. A good supporting electrolyte, such as ionic liquids as reported by J. D. Holbrey, K. R. Seddon, “Ionic Liquids—review”, Clean Product and Process, 1, 223-236, 1999; “Ionic Liquid as Green Solvent: Progess and Prospects”, 24 th American Chemical Society National Meeting, Boston, Mass., 2002; Walkup, Paul C. and et. al., “Production of Esters of Lactic Acid, Esters of Acrylic Acid, Masafumi Yoshio, Tomohiro Mukai, Hiroyuki Ohno, and Takashi Kato, “One-Dimensional Ion Transport in Self-Organized Columnar Ionic Liquids”, J. AM. CHEM. SOC. 9 VOL.126, No. 4, 994-995,2004, used as co-solvents in the esterification compartment improves efficiency. Preferred electrolytes are one or more of 1-Hexyl-3-methyl-3H-imidazolium+tetrafluoro borate], [3-Methyl-1-octyl-3H-imidazolium+tetrafluoro borate], [Trihexyl-tetradecyl-phosphonium+tetrafluoro borate], [1-hexyl-2,3-dimethyl-3H-imidazolium+Trifluoro-methanesulfonate], but these are representative only.
[0036] The present invention has been described with respect to the production of ethyl lactate; however, the invention is not so limited. The invention pertains to the production of a wide variety of esters from lower alcohols and from organic acids. More particularly, the alcohols which may be used in the present invention include but are not limited to methyl, ethyl, propyl or butyl alcohol and may have alcohols up to 6 carbons in the alkyl chain. ethyl, propyl or butyl alcohol and may have alcohols up to 6 carbons in the alkyl chain. Although lactic acid has been used in the specific examples of the present invention, a wide variety of organic acids are applicable, most particularly carbocyclic acids. One or more of a mono, di, tri-carboxyclic acid group may be used and more specifically, acetic acid, lactic acid, propionic acid, 3-hydroxy-propionic acid, butyric acid or succinic acid may all be used in the present invention. Preferably, the reaction chamber containing the organic acid or salt in maintained at a pH in the range of from about 2 to about 7 and the pH in the esterification chamber is preferably maintained in the range of from about 2 to about 7. As previously described in the incorporated patent and patent applications identified above, the ion exchange resins are in the form of a flexible porous ion exchange material containing one or more of anion exchange entities or cation exchange entities or mixtures thereof immobilized with respect to each other with a binder comprising about 25% to about 45% by weight of ion exchange material without substantially coating the entities. In general, the porous ion exchange material contains a porosity somewhere in the range of from about 15% to about 60% and the binder is present preferably in an amount not greater than 80% of the entities. As before mentioned, the esterification chamber may be defined, as previously shown, by two anion exchange membranes or defined by an anion exchange membrane and a bipolar membrane or defined by an anion exchange membrane and a cation exchange membrane. In a combined separative bioreactor/catalytic reactor, each esterification chamber is adjacent a bioreactor chamber or a chamber containing either an organic acid or salt, with the esterification chambers bounded by an anion exchange membrane on one side and either an anion exchange membrane or a bipolar membrane on the other side. In the three chamber configuration, each esterification chamber is adjacent to one bioreactor chamber and an acid/base capture chamber.
[0037] While particular embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications and improvements may be made, for example in the processing of the materials or in the electrode and/or cell design without departing from the true spirit and scope of the invention.
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A method of and apparatus for continuously making an organic ester from a lower alcohol and an organic acid is disclosed. An organic acid or salt is introduced or produced in an electrode ionization (EDI) stack with a plurality of reaction chambers each formed from a porous solid ion exchange resin wafer interleaved between anion exchange membranes or an anion exchange membrane and a cation exchange membrane or an anion exchange membrane and a bipolar exchange membranes. At least some reaction chambers are esterification chambers and/or bioreactor chambers and/or chambers containing an organic acid or salt. A lower alcohol in the esterification chamber reacts with an anion to form an organic ester and water with at least some of the water splitting with the ions leaving the chamber to drive the reaction.
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BACKGROUND OF THE INVENTION
The invention relates to an arrangement for applying a fluid, pasty or gel-like product onto the skin, having a reservoir for the product, and having an application element which is connected to the reservoir via a feed channel.
Arrangements of the type mentioned in the introduction are known. In the case of known application arrangements, the product is usually fed in portions from the reservoir, by way of the feed channel to the application element, where it is then used up by application. Once such a portion of the product has been used up, then it is necessary to actuate a delivery device which, in the case of the known application arrangements, delivers a further portion of the product to the application element. Such a delivery device may be realized, for example, in that the reservoir has a flexible outer wall which can be compressed (tube), as a result of which the product is delivered out of the reservoir. In the case of other application arrangements, the delivery device is realized in the form of a plunger which is guided with sliding action in the reservoir.
From time to time it is undesirable for the delivery device to be actuated during application because this requires manipulations which disrupt the application operation.
An object of the invention is thus to specify an arrangement of the type given in the introduction in the case of which the product can be fed to the application element without there being any need to actuate a delivery device connected to the reservoir.
SUMMARY OF THE INVENTION
The foregoing object is achieved according to the present invention by a device for reversibly decreasing the volume of the feed channel between the reservoir and the application element.
If the volume of the feed channel is reduced, then the pressure in the feed channel increases, as a result of which product located in the feed channel is fed to the application element. The application element is thus supplied with additional product, although there is no actuation of a delivery device, interacting with the reservoir, for the product. This is because the product which is fed to the application element in such a case comes form the feed channel rather than from the reservoir.
A particularly preferred embodiment of the invention provides for the device for reversibly decreasing the volume of the feed channel to be a device for reversibly reducing the length of the feed channel. In the case of this configuration, handling is simplified to a considerable extent because a reduction in length of the feed channel can be achieved by the application element being pressed against the skin, to be precise by the application arrangement being gripped by way of the reservoir. In such a case, the pressure against the skin will result in the feed channel being shortened and thus in the pressure in the feed channel increasing, and this leads to a corresponding quantity of the product passing out of the feed channel to the application element.
In this case, it is particularly preferred according to the invention for the device for reversibly decreasing the volume of the feed channel to be formed by a folding bellows or a diaphragm. This is because such a folding bellows or such a diaphragm is particularly easy to produce and closes off the feed channel in a sealed manner.
According to the invention, the application element may have a covering which has through-passages for the product and covers an opening of the feed channel in the application element. This means that the product is distributed uniformly over the application device, in accordance with the distribution of the through-passages, as a result of which correspondingly uniform application of the product onto the skin is possible.
In addition, or as an alternative, to the above described features according to the invention, the arrangement according to the invention may also provide for the application element to have a covering which has through-passages for the product and, together with a wall encircling the opening of the feed channel, bounds a space for receiving a predetermined quantity of the product, and the wall encircling the opening of the feed channel is flexible at least in certain areas.
It is also the case with this solution that the volume of the space bounded by the covering and the wall encircling the opening of the feed channel is reduced when the application element is pressed against the skin. This results, in turn, in a corresponding quantity of the product being delivered to the covering and/or through the covering.
The wall encircling the opening of the feed channel is preferably formed by a diaphragm.
A further-preferred embodiment of the invention provides for the covering to be retained in a compliant and/or movable manner such that it can assume at least one operating position in which, together with an annular surface which encloses the opening of the feed channel and is directed toward the covering, it bounds a space for receiving a predetermined quantity of the product, and in which the space decreases upon deformation of the covering and/or movement of the covering.
If, in the case of this configuration, the product is delivered by way of the feed channel, then, rather than passing directly, through the covering, onto the outside of the covering (application surface), it is first of all distributed in the space bounded by the covering and the annular surface. This space thus constitutes an intermediate reservoir. The (uniform) distribution of the product into the intermediate reservoir means that, when delivered further, the product emerges uniformly through the through-passages, irrespective of whether the through-passages are in the vicinity of a feed-channel opening or not.
According to the invention, the covering is preferably made of plastic, metal and/or a ceramic material. It is not least on account of their smooth application surface that these materials have proven successful for cosmetics, also in terms of cleanliness and hygiene.
The covering also preferably has a metal mesh.
According to the invention, the covering may have an eroded, pitted and/or corrugated outer surface. The correspondingly concave structures serve as a further intermediate reservoir.
The covering preferably overlaps an outer border of the application element. This achieves the situation where the application surface is free of disruptive fastening elements, for example a fastening frame. It is thus smooth and free of edges.
According to the invention, the covering is elastic. This means that it always resumes its rest position after use.
The invention particularly preferably provides for the through-passages to be closed in the rest state and to open when the product rests against the same under pressure.
In other words, the through-passages act as a “Bunsen valve”. They only open when the product is delivered onto the application surface from the feed channel, but they are otherwise closed, with the result that there is no risk of drying out even when, after use, there is still some product left in the feed channel and/or in the product-receiving space serving as intermediate reservoir. No air passes into the intermediate reservoir through the through-passages either.
The invention may provide for the application surface of the application element to be positioned obliquely in relation to a main axis of the arrangement. Such a configuration is advantageous in terms of handling.
According to the invention, the delivery device provided may be a plunger which seals the reservoir on the side directed away from the application element and is guided with sliding action in the reservoir. In such a case, the delivery of the product from the reservoir to the application element takes place by displacement of the plunger.
In this context, the invention may provide an actuating device for displacing the plunger. An example of such a device is a spindle drive.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail hereinbelow with further details with reference to the attached drawing, in which:
FIG. 1 shows an axial longitudinal section through a first exemplary embodiment of the application arrangement according to the invention, and
FIG. 2 shows an axial longitudinal section through a second exemplary embodiment of the invention.
DETAILED DESCRIPTION
The exemplary embodiment illustrated in FIG. 1 has a reservoir 10 for a cosmetic product 12 . The product may be fluid, pasty or gel-like, a specific example being lipstick.
The reservoir 10 includes a primary reservior 11 which is connected to an application element 16 (having an intermediate or secondary reservior 22 ) via a feed channel 14 comprising a flexible conduit having a flexible wall. The application element 16 has a convering 18 which together define the secondary reservior 22 . The covering 18 is a flexible metal mesh, i.e. a thin metal foil with through-passages. However, the covering 18 may also be made of different materials, for example plastic. In particular in such a case, the through-passages may taper conically to the application surface, with the result that they close of their own accord in a manner of a “Bunsen valve” as long as no pressure is applied from the reservoir. Such configurations are also conceivable in the case of metal coverings.
Together with an annular surface 20 encircling the opening of the feed channel, the covering 18 forms a space 22 which may serve as an intermediate reservoir for the product 12 .
The application element 16 , which has the feed channel 14 passing through it, has a folding bellows 24 which encircles the feed channel 14 in the form of a ring. This makes it possible for the feed channel to be changed in length and thus in volume.
On the side opposite the application element 16 , the reservoir 10 is sealed by a plunger 26 which is guided with sliding action in the reservoir. On that side of the plunger 26 which is directed away from the reservoir 10 , the plunger 26 is coupled to a rotary spindle 28 which, on its outside, bears an externally threaded element 32 which meshes with an internally threaded element 30 . The coupling is such that play S remains.
In order to protect the folding bellows, a protective sleeve 34 is provided, and a protective cover 36 is also provided. The spindle 28 is coupled for rotation to an actuating sleeve 38 , but is retained in an axially displaceable manner in relation to the actuating sleeve 38 . A main axis of the application arrangement is designated by the designation 40 .
The above described application arrangement functions as follows:
By virtue of rotation on the actuating sleeve 38 , the plunger 26 is pushed upward in FIG. 1, as a result of which a corresponding quantity of the product 12 is delivered, by way of the feed channel 14 , into the space 22 and thus to the covering provided with the through-passages. In this state, the product 12 can be applied by the covering 18 being brought into contact with the skin. If, in the process, the covering 18 is curved inward by the action of pressure, then (further) product emerges through the through-passages onto the outside of the covering 18 . If, however, the space 22 no longer contains any product, then application of (more pronounced) pressure, on account of the folding bellows 24 moving from a rest position to a pressure position, shortens the feed channel 14 and thus reduces the volume of the same, as a result of which the pressure in the feed channel 14 increases and further product 12 is fed to the intermediate reservoir 22 and/or to the covering 18 in an unrestricted manner, where it is available for further application.
That exemplary embodiment of the invention which is illustrated in FIG. 1 has the advantage, in particular, that, when a first quantity of the product 12 has been used up by application, all that is required is for pressure, compressing the folding bellows 24 , to be applied to the application element in order for the resulting shortening of the delivery channel 14 to result in further product being delivered into intermediate reservoir 22 and/or to the covering 18 . This pressure on the folding bellows 24 can be applied during application. A possibly laborious operation of actuating the actuating sleeve 38 is not necessary.
The folding bellows 24 is indeed compliant, but not elastic. Nevertheless, it is not possible to rule out this situation where the folding bellows 24 , once compressed, springs back a little, which could result, in some circumstances, in product 12 which has already been delivered into the intermediate reservoir 22 being sucked out again.
The play S which has already been mentioned is provided as a countermeasure for this. Following actuation of the actuating sleeve for delivering the product 12 in the direction of the application element 16 , the actuating spindle 28 butts against the plunger 26 . If the folding bellows 24 then springs back a little following the compression, then it is possible to equalize the resulting negative pressure by corresponding movement of the plunger 26 by the amount of play S, as a result of which the product 12 which has already been delivered into the intermediate reservoir 22 is prevented from being sucked out again. The play S can be set in accordance with the elasticity of the folding bellows 24 . Furthermore, the use of “Bunsen valves” as through-passages in the covering 18 prevent the product 12 from being sucked out of the intermediate reservoir 22 .
In FIG. 2, those components which have also already been illustrated in FIG. 1 are provided with the same designation.
The exemplary embodiment illustrated in FIG. 2 differs from that according to FIG. 1, in particular, in that the folding bellows 24 according to FIG. 1 is replaced by a diaphragm 42 , which forms the wall 42 , located opposite the covering 18 , of the space 22 formed in the application element 16 .
If pressure is applied to the application element 16 , for example in the axial direction, then the diaphragm 42 yields, as a result of which the volume of the space 22 is decreased. A reduction in volume goes hand-in-hand with an increase in pressure, which has the effect of causing (further) product 12 to be delivered to the covering 18 and/or through the covering 18 .
Although not illustrated in FIG. 2, it is also possible, in the case of the exemplary embodiment according to FIG. 2, to provide a device for adjusting the plunger 26 .
The features of the invention which have been disclosed in the above description, the claims and the drawing may be essential both individually and in any desired combinations for the purpose of realizing the various embodiments of the invention.
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A cosmetic applicator for applying a cosmetic product to the skin has a primary reservoir and a secondary reservoir with a conduit interconnecting the primary reservoir with the secondary reservoir. A flexible member is provided for compressing the cosmetic product for feeding same to an application element.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to and claims priority to two co-pending provisional applications, Application Ser. No. 61/853,836 entitled An Iron Sight for a Firearm Having an Aperture-Type Front Sight, and Method of Use, filed Apr. 12, 2013, inventors Dwight Williams and Ken Lloyd and provisional Application Ser. No. 61/854,899 filed May 3, 2013 entitled An Iron Sight for a Firearm Having an Aperture Type Front Sight, and Method of Use with inventors Dwight Williams and Ken Lloyd. The content of both provisional patent applications is herein and hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention relates to iron sights for firearms, and more particularly to front iron sights.
BACKGROUND OF THE INVENTION
Terminology
“Front sight” refers to the sight nearest the muzzle end of the firearm. “Rear sight” refers to the sight nearest the shooter or butt of the firearm. Generally with the instant inventive front sight, the rear sight is anticipated to comprise a standard notch sight or a standard peep sight. “Leading” is used herein to refer to the portion of the sight nearest the shooter, as installed on the firearm in operation, and “trailing” is used to refer to the portion of the sight opposite the leading portion, or furthest from the shooter in operation.
“Sight picture” is used to refer to a view resulting from a selective alignment of a front sight with a rear sight, down a sightline. A traditional sight picture comprises the top of a traditional bar or post front sight aligned with the top of the sides of a rear notch sight, or aligned with the center of a rear peep sight. The instant invention preferably offers four sight pictures, to be selected depending upon shooter preferences, distance away from target and characteristics of the firearm and/or bullet. “Hold” is used to refer to where, with respect to a front sight, a selected target point (or point on a target) is aligned. For instance the top of the bar or post is typically “held” on the point on a target selected with conventional front sights. The center, bottom, top of aperture or top of housing may be “held” on the point on the target selected with the instant front iron sight. “Placement” is used to refer to the selection of the target point itself on the target for aiming purposes. Factors such as distance away and characteristics of the firearm and bullet may affect “placement.” For example, in regard to “placement” with respect to a human silhouette, if the hit should be at the chest, “placement” might be at the head or at the belt buckle, to compensate for an anticipated fall or rise of the trajectory, respectively, given the distance away and the firearm. As discussed above, the conventional bar or post front sight typically provides only one sight picture and one hold position. As a result, when a placement of the target point on the target is high on the target, the bar or post obscures the view of most of the target along the sightline.
“Top flat” refers to a flat top of a leading end of a housing of a front sight. With traditional “factory” post or bar front iron sights, the top flat is aligned with the top of the sides of a notch iron sight and a selected target point is held on the center of the top flat. This is discussed above.
Note: practically speaking with firearms, including pistols and rifles, a front sight will be approximately 18 to 36 inches away from a shooter's eye. That variation in distance has not shown itself to be a critical factor in regard to the structure of the front iron sight of the instant invention.
The instant invention comprises a novel front iron sight for a firearm and its method of use. The novel iron sight can be utilized with traditional rear sights. For example, the rear sight might comprise a standard notch iron sight or standard peep iron sight, as is known in the art. The novel front iron sight comprises a housing defining a cylindrical or tubular (of some shape) aperture. Preferably, the front iron sight will comprise an aperture of a length at least three times its diameter, between a leading end and a trailing end of the aperture. Preferably, the front iron sight is formed from a block of hard durable material, such as metal or certain plastics or the like. Preferably, the block has an aperture formed therethrough as by milling or casting or molding or laser cutting or the like. The aperture generally runs from a leading end of the housing to a trailing end of the housing. Preferably the trailing end of the aperture is somewhat larger in diameter than the leading end of the aperture. Preferably, the housing walls defining the aperture expand radially outward slightly, from leading end of aperture to trailing end of aperture, creating a slight “cone” effect.
Preferably, at least 15% of the body of the housing containing the aperture and defining the leading and trailing ends of the aperture is also milled out or otherwise “opened” on the top, or on the top and side portions, into one or more openings, between the leading and trailing ends of the aperture, to admit light. Translucent or transparent material could be added to some or all of the open space admitting light, it should be understood.
The novel front iron sight can be viewed as preferably a partial hybrid of a squared post or bar front sight and open tube front sight. (Tubular front sights are disclosed by Parker and Peddie, discussed below.) The instant invention, however, provides the novelty of a partially open (with or without transparent or translucent material, hereinafter referred to as “open”) top portion(s) of the housing defining the aperture. The opening preferably serves to illuminate the leading end of the aperture from behind, as well as preferably the housing leading end top flat and housing leading end exterior side edges. The top opening together with the opening of the leading end of the aperture enhance illumination of the housing top flat, both from behind and from within.
Preferred straight exterior side wall portions of a leading end of the housing, as provided with the above described back and interior illumination, facilitates aligning the leading end of the housing of the instant front iron sight within a rear sight straight sided notch, or within a rear sight round peephole, quickly and accurately, both vertically and horizontally. This has been confirmed by testing.
Advantages
The instant front iron sight, having both an open aperture and open housing top portions:
(1) helps illuminate and define the aperture and the leading end exterior edges of the housing, including a leading top flat over the aperture and housing leading end exterior side wall edges; (2) obscures less of a target during sighting and shooting than a solid bar or post; (3) provides various “sight picture” options, and (4) provides alternate “hold” positions for a selected target point with respect to the front iron sight, including on the top of a flat as well as various positions in the center of the aperture, the former being especially useful for quick shots at a short distance and the latter being especially useful for long distances. Importantly, none of these alternate “hold” positions significantly obscures the target, even when “placement” of the aim point on the target is high on the target.
Further, the leading end of the aperture helps gauge the distance away of a target by noting how fully a target of a known size fills the aperture. The leading end of the aperture thus serves as a distance finder.
Surprising results in speed and accuracy at a variety of distances have been proven by repeated testing by experts and by novices of the instant invention. Much of the lengthy and varied testing process is recorded on the applicant's website. The various embodiments had to be developed and proven through testing.
The instant invention is particularly useful for rapid target acquisitions, more peripheral vision, target clarity, assistance in range finding and accuracy. All of the above is accomplished without batteries or making handgun adjustments. The instant invention gives the handgun user almost carbine accuracy. Law enforcement officers, highway patrol, border patrol, city police, military, special ops, pilots, truck drivers, sport shooters, ranchers and home protection would all benefit from the above advantages for a side arm pistol.
The instant front iron sight can be made to accommodate different velocities for a 9 mm—45 ACP or other handgun, as well. The thickness of material between flat top and upper part of orifice would be one consideration. Another consideration would be the view area of the orifice at optimum range or maximum ranges. Note that 150 yards with the pistol sight is the size of normal man size target. So if a man appears smaller vis-à-vis the aperture, he is likely farther away. If a face fits in the orifice he is likely closer than 30 yards. The smaller the target appears, the further away it will be and so forth.
As an example re distance finder: 14 inches fits just inside a preferred embodiment of the aperture at 100 yards; 16 inches fills the aperture at 100 yards; 20 inches fills the aperture at 125 yards and 23 inches fills the aperture at 175 yards. At around 200 yards, 32 inches fits inside the aperture. The rear peep and instant front sight allows the shooter to see more of the target with a crisp view of the aperture.
Given a peep rear sight, an advantage of the instant invention is that the eye can quickly center the aperture of the instant front iron sight with the aperture of the rear sight. This also allows for quick range finding. On a rifle the rear sight will likely be a peep sight. Note: the human face is approximately 6″ across. This knowledge can allow the instant front iron sight to function as a target distance indicator. Note also: the crispness or clarity of the flat top of the instant front iron sight is a result of the light both above and below the flat top or of the front sight. Clarity and brightness is one advantage of a scope on a rifle. The light above and below with the instant front iron sight gives an approach to such clarity.
Discussion of Prior Art
One limitation of a typical “factory” front iron sight comprising a post or a bar, for coordination with a notch or a peep rear iron sight, is that the combination frequently provides only one hold” position of the front sight with regard to a target point. This “hold” position typically consists of aligning the top of the flat of the post with the target point. A second limitation is that the post or bar obscures vision of portions of the target below that “hold” position. Thus, when the “hold” position, to compensate for the distance away, must be placed at the top of a target silhouette, most or all of the target is obscured by the front sight post.
Parker (U.S. Pat. No. 5,327,654) and Peddie (U.S. Pat. No. 1,012,427) disclose front iron sight structures comprising an “aperture,” a housing defining a front iron sight cylinder or tube. One distinction of the instant invention from the Parker front iron sight, however, is that the Parker aperture appears too large, its diameter appearing to be twice the height of the notch. Parker's housing also lacks a top flat. Because of the absence of a flat top portion and straight side wall portions on the leading end of the housing, a shooter would have difficulty aligning the Parker rounded housing walls within a squared notch straight walls and difficulty “holding” or aligning a target point on the top of the Parker circular front housing wall. Maintaining the horizontal position of a tubular front sight with rounded end housing walls within a notch defined by straight walls is difficult. And importantly, Parker provides no opening(s) in top portions of his housing to communicate in ambient light.
Peddie, to note a basic difference in design, does not utilize a rear sight at all or disclose forming any sight picture alignment between a rear sight and a front sight. Peddie does not disclose any opening in the top of the housing of his cylinder or tube front sight for providing illumination, within the cylinder or tube, of the aperture. Like Parker, Peddie's housing does not provide a flat top portion or straight exterior side portions for hold and alignment purposes with a rear sight.
In regard to other prior art that teaches hooded crosshairs or hooded beads on a post as a front ironsight, the instant aperture is sufficiently small that crosshairs or beads on a post in the sightline within the aperture would significantly obscure any target at significant distances. The instant invention calls for an open, unobstructed aperture.
SUMMARY OF THE INVENTION
The invention includes a front firearm iron sight including a housing defining a front iron sight with an aperture through the housing. Preferably the aperture is at least 0.20 inches between a leading end of an aperture and a trailing end of the aperture. Preferably the aperture provides an open unobstructed sightline therethrough, with a leading end of the aperture having a diameter of approximately 0.10 inch +/−0.05 inches. Preferably the leading end of the housing presents, along a sightline, approximately straight exterior sidewall portions and approximately straight top flat portion.
Preferably at least 15% of the top portion of the housing between the leading end and the trailing end of the aperture is open to provide passage of ambient light to a backside of the leading end of the aperture.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention can be obtained when the following detailed description of the preferred embodiments are considered in conjunction with the following drawings, in which:
FIGS. 1-5 provide an embodiment of the instant front iron sight as installed on a pistol. FIG. 1 shows a view from the shooter's eye, referred to as the rear of the pistol. FIG. 2 illustrates a perspective of the sight from the rear and slightly to the left. FIG. 3 illustrates a side view of the front sight on the pistol. FIG. 4 illustrates a front view or a view down the muzzle of the front sight. FIG. 5 illustrates at top view of the sight.
FIGS. 6 and 7 offer simplified drawings of a leading end of the front iron sight and a top view of the same embodiment.
FIGS. 8A-8C illustrate an embodiment of the instant front sight viewed through a notch rear sight and indicates that the shape of the aperture, although commonly a circle, could be oval or diamond or rectangular or any other useful shape.
FIGS. 9A-9B illustrate a front sight from the side and from the top to illustrate that the openings in the top and/or possibly in the top of the sides of the front iron sight could be of different sizes and positions.
FIGS. 10A-10C illustrate different openings that can be used in the top of a front sight to communicate light to the aperture.
FIGS. 11A-11D are perspectives of a front sight for rifles with a dovetail and for a Glock. FIGS. 12A-12E illustrate engineering drawings for a prototype of the instant front iron sight.
FIG. 13 illustrates a plurality of sight pictures, or alignments of the front sight with a rear sight, that are possible with an embodiment of the instant inventive front iron sight.
FIGS. 14A-14B illustrate a variety of sight pictures available for an embodiment of the instant front iron sight coordinated with a rear peep sight.
FIGS. 15A-15C illustrate various sight pictures possible with the inventive front sight and a rear peep sight.
FIG. 16 illustrates four key “holds” available with an embodiment of the instant invention, holding target X on the front sight.
FIG. 17 illustrates three key placements of a target X on a silhouette, as is known in the art.
FIGS. 18A-18B illustrate a variation in how a target fills an aperture of the front sight as a function of distance away.
The drawings are primarily illustrative. It would be understood that structure may have been simplified and details omitted in order to convey certain aspects of the invention. Scale may be sacrificed to clarity.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The drawings illustrate the structure of preferred embodiments of the instant front iron sight FS, together with a sight system enabled thereby. FIGS. 1-5 are drawn from pictures of an embodiment of the instant invention installed on a pistol FA.
FIG. 1 captures the relative size and proportion of an exemplary embodiment of the instant front iron sight FS, the figure depicting a view taken down a sightline of a pistol FA from the shooter's perspective. FIGS. 2-5 offer views of the same front iron sight and pistol taken from the left rear, from the side, from the front and from above the gun. FIG. 2 offers a perspective of the instant front iron sight taken from the rear and slightly to the left. FIG. 3 offers a side view of the front iron sight. FIG. 4 offers a perspective taken from the front or muzzle end of the iron sight, showing some of the “opening” HO in the top of the front sight housing, the opening providing illumination to the aperture AP. FIG. 5 depicts a top view of the embodiment, showing an open top aperture.
The inventive front iron sight can be machined or milled out or cast from a metal or synthetic material such as space age plastic that has the qualities of brass, steel or aluminum. The entire sight could be manufactured with any of such material options. A block of clear or magnified material might be put in the middle area to further enhance visibility and strengthen milled walls.
FIGS. 6-7 illustrate the scale of a preferred embodiment of the front iron sight FS. In a preferred embodiment the width of the leading end of the housing LEH of the front sight is approximately 0.130 inches or a 130 thousandths of an inch. The width of the leading edge of the aperture LEA in the leading end of the housing LEH is approximately 82 thousandths of an inch or 0.082 inches. The space between the top of the leading end of the aperture and the flat top TF and side portions SW of the leading end of the housing LEH is approximately 20 thousandths of an inch or 0.020 inches. FIG. 7 illustrates structuring of a milled out (or the like created) area HO of top portions of the housing H of the front iron sight, for admitting light. Although not illustrated in the above drawings, the trailing end of the aperture TEA is preferably slightly larger in size than the leading end of the aperture, by about 10 percent, in order to not obstruct view through the leading end of the aperture. See FIGS. 12 A-E. Technically, a trailing end of the aperture is not necessary, but it provides structural integrity, important to an iron sight.
FIGS. 8A-8C illustrate that the aperture AP of the instant front iron sight need not be circular. A circular aperture is easier to mill out. The aperture, however, could be oval, FIG. 8C , or rectangular, FIG. 8B , or diamond shaped, FIG. 8A , or otherwise. FIGS. 8A-8C illustrate such different sized apertures in a front sight as aligned within a rear notch sight NRS.
FIGS. 9A , B and 10 A, B, C illustrate a side view and a top view of an embodiment of the instant front iron sight, in particular to illustrate the possible placement of openings or holes HO for admitting light into the aperture AP of the sight. FIG. 9A illustrates that side holes may be added for additional light. FIG. 9B illustrates the use of a large front and large rear hole, possibly with smaller holes in the side to include greater light.
The applicant performed testing in order to determine the least amount of light required to see well in order to engage targets at ranges within a firearm's capability. It is preferred that the instant front iron sights are useful in rugged environments. While more light is preferable, the front sight must also be of sufficiently rugged construction as to not be deformed. It was determined that holes for light in the top sides of the sights add more light but were generally not needed under normal shooting conditions. Of course, the holes formed in the sight do not have to be round.
FIGS. 10A and 10B illustrate further holes HO in the top of a front iron sight. The instant inventor experimented with holes varying in size from 0.625 through 0.930. It is believed that a series of holes is stronger than one long milling cut. A larger hole was determined to be preferred near the leading end of the aperture LEA of the sight. Again, FIG. 10B illustrates that greater distance between the holes allows for less light but makes for a more rugged sight. Again, a larger hole close to the leading end of the aperture is important. The second most important hole appears to be a hole near the trailing end of the aperture.
FIG. 10C illustrates a milled out hole in the top of the sight with an added bridge BR for strength.
FIGS. 11A-11D illustrate various commercial embodiments of the instant invention. FIG. 11A is a front sight for a 1911 rifle with a dovetail for installation. FIG. 11B and 11C illustrate additional front sights for rifles with dovetails. FIG. 11D illustrates a front sight for a Glock.
FIGS. 12A-12E represent engineering drawings for a front sight prototype.
FIG. 13 presents a simple illustration of a variety of four sight pictures offered by the instant invention as combined with a rear notch sight NRS. Position A which could be used for 0 to 25 yards away aligns the top of the housing H of the inventive front iron sight with the top sides of the rear notch sight NTW. Position B, possibly for use at 100 yards, aligns the top of the aperture with the top of the notch sides. Position C which could be used for 150 yards aligns the center of the aperture with the top of the notch sides. Position D which could be used for distance of 200 yards aligns the bottom of the aperture with the top of the notch of the rear sight.
FIGS. 14A and 14B illustrate two different sight pictures using the inventive front iron sight and a rear peep sight PRS. FIG. 14A illustrates aligning the top of the housing of the front of the inventive front iron sight with the center of the peep. FIG. 14B illustrates aligning the center of the aperture of the inventive front iron sight with the center of the peep. The position of FIG. 14A might be used for short to medium range shots, depending on velocity and ballistic characteristics of the bullets. It might be used for shots of to 300 yards. The position for FIG. 14B might be used for extended or long range shots, shots of 300 or greater yards, again depending on the velocity and ballistic co-efficient. For even longer range the bottom of the aperture might be centered in the peep.
FIGS. 15A-15C illustrate again sight pictures, where X is the hold point, coordinating the instant inventive front iron sight with a peep sight PRS as typically found in a rifle. FIG. 15A aligns the bottom of the aperture with the center of the peep. FIG. 15B aligns the center of the aperture with the center of the peep and FIG. 15C aligns the top of the aperture with the center of the peep. Notice that the aperture in these embodiments is square or rectangular.
FIG. 16 again illustrates 4 key holds of a target X on a front sight. FIG. 17 illustrates three key placements of a target X on a silhouette, chin CH, heart HT and belt buckle BB.
FIGS. 18A and 18B illustrate how a target T fills an aperture AP differently depending upon the distance away of the target. In FIG. 18A only a portion of the target is visible through the aperture. In FIG. 18B almost all of the target is visible through the aperture. FIG. 18B might be what one sees of a human silhouette at 100 yards. FIG. 18A might be what one sees of a human silhouette at 25 yards. It can be seen, thus, that instant front iron sights functions incidentally as a distance finder, since the relative size of a target in regard to the front sight leading aperture can be understood as an indicator of the distance away of the target.
Testing
Extensive testing has been carried out with the instant invention, informing its final structure and substantiating its superiority to the available prior art. Results of the testing can be found at the Battle Sight website, including comparative testing results between the Battle Sight system and other sight systems. The shooting results also indicate different shooters.
The foregoing description of preferred embodiments of the invention is presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the invention to the precise form or embodiment disclosed. The description was selected to best explain the principles of the invention and their practical application to enable others skilled in the art to best utilize the invention in various embodiments. Various modifications as are best suited to the particular use are contemplated. It is intended that the scope of the invention is not to be limited by the specification, but to be defined by the claims set forth below. Since the foregoing disclosure and description of the invention are illustrative and explanatory thereof, various changes in the size, shape, and materials, as well as in the details of the illustrated device may be made without departing from the spirit of the invention. The invention is claimed using terminology that depends upon a historic presumption that recitation of a single element covers one or more, and recitation of two elements covers two or more, and the like. Also, the drawings and illustration herein have not necessarily been produced to scale.
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A front iron sight for a firearm including a housing defining an open unobstructed tubular aperture for a sightline therethrough and a partially open top portion, and preferably with a leading end of the front iron sight housing including a straight flat top portion and straight exterior side wall portions.
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BACKGROUND OF THE INVENTION
This invention relates to an air fuel injection system and more particularly to an improved silencing and cooling arrangement for an air fuel injector unit.
The advantages of providing an air and fuel injector for internal combustion engines, particularly those operating on the two cycle crankcase compression principle, are well known. In accordance with such injectors, the injection unit normally includes a housing having a nozzle port and an injection valve which opens and closes the nozzle port and controls the ignition of both fuel and air under pressure to the combustion chamber of the engine. The injection valve may be operated in one of a wide variety of manners and frequently an electrical solenoid is employed for opening and closing the injection valve. Of course, the use of such valve actuators and the opening and closing of the valve can generate noise which may be objectionable.
It is, therefore, a principal object of this invention to provide an improved air fuel injector unit having a silencing arrangement.
It is further object of this invention to provide an arrangement for silencing the valve actuator of a fuel air injector unit.
In addition to the noise problem, the use of an electrical solenoid for operating the injection valve can give rise to other objectionable characteristics. That is, the electrical actuator will generate some heat and this heat can be passed on to both the fuel and air injector and can decrease the efficiency of the engine.
It is, therefore, a still further object of this invention to provide an improved fuel air injector and an arrangement for cooling it.
It is a further object of this invention to provide a cooling arrangement for a fuel air injector wherein the compressed air supplied to the injector is also used as an arrangement for cooling the injector.
SUMMARY OF THE INVENTION
A first feature of this invention is adapted to be embodied in a fuel air injection unit for injecting fuel and air to an internal combustion engine and comprises a housing assembly having an injector port and an injection valve supported for movement between an open position and a closed position for controlling the flow through the injector port. An actuator is provided for the injection valve for operating the injection valve between its positions. A fuel injector is mounted in the housing assembly for injecting fuel thereto for discharge when the injection valve is in its opened position. An air inlet port is also provided in the housing assembly for receiving compressed air for discharge from the injection port when the injection valve is opened. In accordance with a first feature of the invention, a sound insulating housing at least in part encloses the housing assembly.
In accordance with another feature of the invention, cooling air is circulated through the housing assembly for cooling the enclosed portion of the injector unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view taken through one cylinder of a multiple cylinder, two cycle, crankcase compression engine constructed in accordance with an embodiment of the invention with another embodiment shown in phantom lines.
FIG. 2 is a side elevational view, with portions broken away, of the engine and looking generally in the direction of the arrow 2 in FIG. 1.
FIG. 3 is a cross sectional view taken through one of the injectors on the same plane as FIG. 1 but looking in the opposite direction.
FIG. 4 is a top plan view of the fuel injector assemblies with a portion broken away.
FIG. 5 is a side elevational view of the fuel injection assemblies looking from the side to which the air manifold is affixed with a portion broken away.
FIG. 6 is a schematic view showing the fuel air injection system and the controls therefor.
FIG. 7 is a partial cross-sectional view, in part similar to FIG. 1, and shows another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawings and initially primarily to FIGS. 1 and 2, a three cylinder, in line, two cycle, crankcase compression, internal combustion engine constructed in accordance with an embodiment of the invention is identified generally by the reference numeral 11. The engine 11 is, as noted, illustrated to be a three cylinder, in line type engine. It is to be understood, however, that the invention may be also employed in conjunction with engines having other numbers of cylinders and other cylinder orientations. In fact, certain features of the invention can be utilized in conjunction with rotary rather than reciprocating type engines and, in addition, some features of the invention may also be employed in engines operating on the four stroke rather than two stroke principle. The invention, however, has particular utility in conjunction with two stroke engines.
The engine 11 is comprised of a cylinder block assembly, indicated generally by the reference numeral -2, in which three aligned cylinder bores 13 are formed by cylinder liner 14 that are received within the cylinder block 12 in a known manner. Pistons 15 are supported for reciprocation within each of the cylinder bores 14 and are connected by means of respective connecting rods 16 to a crankshaft 17 that is journaled for rotation within a crankcase chamber 18 formed by the cylinder block 12 and a crankcase 19 in a known manner.
A cylinder head assembly 21 is affixed to the cylinder block 12 and has individual recesses 22 which cooperate with the piston 15 and cylinder bore 13 to form combustion chambers 23. The heads of the pistons 15 are provided with bowls 24 so as to further form these combustion chambers 23.
An air charge is delivered to the crankcase chambers 18 associated with each of the cylinder bores 13 by an induction system that includes a throttle body, indicated generally by the reference numeral 25, that receives air from an air cleaner (not shown). This throttle body 25 includes a throttle valve (not shown) which is manually operated and the position of which is sensed by a potentiometer 26 to provide a throttle valve position signal for controlling the fuel injection system to be described. In addition, a sub injector 27 may be provided in the throttle body 25 so as to inject additional fuel under certain running conditions.
The throttle body 25 delivers the air to an induction system, indicated generally by the reference numeral 28, and which includes a plenum chamber 29. The plenum chamber supplies air through manifolds 31 to inlet ports 32 associated with each crankcase chamber 18. These crankcase chambers 18 are sealed from each other, as is typical with two cycle engine practice. A reed type check valve 33 is positioned in each inlet port 32 so as to prevent reverse flow when the charge is being compressed in the crankcase chambers 18 by downward movement of the pistons 15.
The compressed charge is transferred to the combustion chambers 23 through suitable scavenge passages (not shown). This charge is then further compressed in the combustion chambers 23 by the upward movement of the pistons 15 and is fired by a spark plug 34 mounted in the cylinder head 21 with its gap 35 extending into the combustion chamber 23.
The burnt charge is then discharged from the combustion chambers 23 through exhaust ports 36 in which exhaust control valves 37 are provided. The exhaust control valves 37 are operated so as to provide a reduced compression ratio under high speed, high load operating conditions in a suitable manner. The exhaust gases are then discharged to the atmosphere through an exhaust system which includes an exhaust manifold 38.
The fuel charge for the combustion and an additional air charge is supplied by injector units 39 which are shown in most detail in the remaining figures and will now be described by reference additional to these remaining figures.
The injectors 39 include a housing assembly (FIG. 3), indicated generally by the reference numeral 41, which is comprised of a lower housing piece 42 and an upper housing piece 43. The lower housing piece 42 has a cylindrical portion 44 that is received within a suitable bore formed in the cylinder head and terminates at a nozzle portion 45. The nozzle portion 45 is formed by an insert, indicated generally by the reference numeral 46, which has a cylindrical portion 47 that is disposed radially inwardly of a bore 48 formed in the cylindrical portion 44 of the lower housing portion piece 42. This forms a chamber 49 to which fuel is delivered, in a manner to be described. The nozzle opening 45 is formed by an enlarged diameter portion of the insert 46.
An injection valve, indicated generally by the reference numeral 51, has a head portion 52 that cooperates with the nozzle seat 45 so as to open and close it. The injection valve 51 has a reduced diameter portion 53 that extends through a bore in the insert piece 46 and which is connected at its upper end to an armature plate 54 of a solenoid assembly, indicated generally by the reference numeral 55. The upper end of the valve stem 53 is threaded as at 56 so as to receive a nut 57 to provide an adjustable connection to the armature plate 54.
A coil compression spring 58 acts against the armature plate 54 and urges the injection valve 51 to its normal closed position as shown in the figures of the drawings. A solenoid winding 59 encircles the upper end of the valve stem 53 and when energized will attract the armature plate 54 downwardly to compress the spring 58 and open the injection valve 51.
The valve stem 51 is provided with upper and lower extension lugs 61 and 62 that slidably engage the bore in the insert piece 46 so as to support the valve 51 for its reciprocal movement without interfering with the air flow therepast.
The cylindrical portion 44 of the housing piece 42 is formed with one or more annular grooves in which an O ring seal 63 is provided for sealing with the cylinder head. In a like manner, its internal surface is formed with an annular groove so as to receive an O ring seal 64 which seals with the enlarged end of the insert 46.
The housing piece 42 has an enlarged flange 65 formed at its upper end which is received within a counterbore formed in the lower, face of the housing piece 43. Socket headed screws 66 affixed the housing pieces 42 and 43 to each other and an O ring seal 67 provides a seal between these pieces. The insert piece 46 has an enlarged headed portion 68 that is received within a bore formed in the housing piece 43 at the base of the counterbore which receives the flange 65 of the housing piece 42. Above this bore, the housing piece 43 is provided with a further bore that receives a sleeve 69 that is threaded to the core of the solenoid winding 59 and against which the coil compression spring 58 bears. This sleeve 69 provides a combined mounting function for the winding 59 and preload adjustment for the spring 58. The sleeve 69 is held in position by means of a lock screw 71 which is threaded through the housing piece 43 and which is accessible through an opening 72 formed in the side thereof. The opening 72 also admits air, in a manner to be described, which can flow through a slotted opening 73 in the sleeve 69 so as to be received in a gap 74 formed around the valve stem 53 and the interior of the insert piece 46.
The air is delivered to the opening 72 from an air manifold, indicated generally by the reference numeral 80, and which is affixed to the injector bodies in a manner to be described. The air manifold 80 has a transversely extending passage 75, one end of which is connected to a regulated source of air pressure (to be described). The bore 75 is intersected by crossbores 76, the outer ends of which are closed by plugs 77. The manifold 80 is further provided with intersecting passages 78 which communicate with the openings 72 in the housing piece 43 so as to permit air under pressure to enter the aforenoted chamber 74.
Air leakage from around the solenoid 55 is precluded by means of a cap 81 that is affixed to the upper end of the housing piece 43 and which engages an 0 ring seal 82.
A fuel injector 83 is provided for each of the injectors 39. The fuel injectors 83 may be of any known type. Fuel is delivered to all of the fuel injectors 83 by a fuel manifold 84 that is affixed to the tips 85 of the fuel injectors 83 and which are sealed thereto by 0 ring seals 86. A manifold line 87 which communicates with a regulated pressure fuel source (to be described) delivers the fuel to the fuel injectors 83. The fuel manifold 84 is mounted on a mounting bracket that is shown in phantom in FIG. 3 and which is identified by the reference numeral 88.
For ease of location, the housing piece 43 is formed with a bore 89 that is disposed at approximately a 45 degree angle to the axis of the injector valve 51. These bores 89 receive the nozzle portions of the injectors 83. O ring seals 91 and 92 provide a sealing function around these nozzle portions so that the fuel which issues from the injectors 83 will be directed toward a passage 93 bored into the housing piece 43. These passages extend from the bores 89 and specifically from shoulders 94 formed at the base of these bores 89. The fuel injector nozzle end portions 95 are spaced slightly from the end walls 94 so as to provide a chamber through which the fuel will be injected. By using this close spacing, no significant dead space exits between the injector nozzle and the passage 93. Dead space will be eliminated and better fuel injection control can be obtained.
The housing piece passage 93 is intersected by corresponding passage 96 formed in the housing piece 42. These passages terminate in an annular recess 97 formed in the periphery of the insert 46 so as to communicate the fuel with the chamber 49. At the lower end of the chamber 49, there is provide another annular relief 98 that is intersected by a plurality of ports 99 that extend through the lower end of the enlargement of the insert piece 46 at the valve seat 45. Hence, when the valve head 52 moves to its open position, both fuel and air will be valved into the combustion chambers 23.
It has been previously noted that the air manifold 80 has been affixed to each of the injectors 39. As may be best seen in FIG. 5, this is achieved by a plurality of socket headed screws 101. By forming the air manifold from a relative rigid material such as aluminum extrusion, an aluminum die casting or rigid plastic, enough rigidity can be added to the system so that all of the injectors 39 and air manifold 80 can be removed from the engine as a unit.
The assembly is mounted to the engine by means of mounting lugs 102 formed on the injector housing portions 43 through which threaded fasteners 103 extend. Hence, the unitary assembly consisting of the individual injector nozzles 39 and air manifold 80 can be removed from the engine easily by removing the socket headed screws 83 and the entire assembly. This obviously facilitates servicing.
It should be readily apparent that the opening and closing of the injector valves 51 by actuation of the solenoid 55 and movement of the armature plate 54 will generate some noise. In addition, the alternate energization of the solenoid windings 59 will also cause certain heat to be generated. In order to dampen this noise and to cool the injectors 39, there is provided a sound insulating cover assembly, indicated generally by the reference numeral 104 which is a generally dome shaped member and which may be formed from sheet metal or the like.
The member 104 has side walls 105 that extend downwardly toward the cylinder head 21 and which terminate in edges 106 that receive a sealing gasket 107 that is compressably engaged with the cylinder head 21 for sealing purposes. The insulating cover 104 is held in place by threaded fasteners 108 which pass through openings in the side wall 105 and which are surrounded by elastomeric grommets 109 for sealing purposes. These fasteners 108 are secured in a side wall 111 of the manifold 80. In addition, further fasteners 112 are surrounded by elastomeric grommets 113 and engage the housing piece 43 of the injector housing assembly 41. As a result, there will be good sound insulation. One of the side walls 105 of the insulating housing 104 is formed with a plurality of aligned apertures 113 through which the fuel injectors 83 extend. Alternatively, the housing assembly 104 may be extended as shown at 121 in FIG. 7 so as to completely enclose the fuel injectors 83 and also the spark plugs 34.
In addition to providing sound insulation, air is passed through the interior of the insulating housing 104 in a manner to be described so as to provide cooling for the injectors 39 and specifically the solenoids 55 thereof. This air flow will insure against overheating of the air and fuel injected by the injectors 39.
Referring now to FIG. 6, a schematic of the system is illustrated which will indicate how the air and fuel are supplied to the injectors 39 and also one embodiment of how the air flow path may be accomplished through the insulating housing 104.
The fuel system includes a fuel tank 125 from which fuel is drawn by a high pressure fuel pump 126 and which is delivered through a conduit 127 to the fuel manifold 84 and specifically the passage 87 thereof. At the other end of the fuel manifold 84, a line extends to a pressure regulating valve 128 that serves to regulate both fuel pressure and air pressure so as to provide a predetermined pressure differential therebetween. The fuel pressure is regulated by bypassing fuel to a further line 129 that supplies the subinjectors 27. A secondary pressure regulator 131 regulates the pressure of fuel delivered to the sub injectors 27 by bypassing excess fuel flow back to the tank 125 through a return line 132.
The air pressure system includes an air pressure compressor 133 that is driven from the engine 11 in a suitable manner and which outputs pressure to a line 134. The line 134 is connected to the air manifold 84 at one end of the passage 75. The opposite end of the passage communicates through a conduit with the regulator 128 so as to regulate the air pressure in relation to fuel pressure, as aforenoted. A pressure differential sensor 135 outputs a signal f to a control unit 136 which controls the air fuel injectors 39 and the sub injectors 27 in a manner to be described. The air pressure relieved by the valve 128 is passed back through a conduit 137 to a fitting 138 (FIGS. 4 and 5) formed at one end of the housing 104. An outlet fitting 139 at the opposite end of the insulating housing 104 is connected to a conduit 141 which, in turn, delivers the air to the exhaust system for the engine, preferably upstream of its catalytic converter (if one is employed).
Returning again to FIG. 6, the control unit 136 receives an input signal J determinative of the engine running conditions and output signals c to the fuel injectors 83 to actuate them, a signal d to the solenoid 55 for actuating the injector valve 51 and a signal e to the sub injectors 27 for actuating them. Any suitable control strategy may be employed, as is known in this art.
It should be readily apparent from the foregoing description that the described construction permits a very effective fuel air injection system, one which not only provides noise insulation, but also heat insulation. The air cooling is achieved by circulating the air from the air compressor through the insulating housing 84. One specific flow path has been illustrated, but it should be readily apparent to those skilled in the art that other flow paths may be employed. A wide variety of other changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.
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An air fuel injector system for a two cycle crankcase compression internal combustion engine, including an insulating housing encircling and enclosing at least a portion of the air fuel injectors for sound deadening. In addition, air is circulated through this housing to cool the injectors. The circulated air is air that is bypassed from an air compressor to maintain regulated pressure for the air fuel injectors.
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BACKGROUND
This disclosure relates generally to applying a coating and, more particularly, to applying a coating to a perforated surface.
As known, gas turbine engines, and other turbomachines, include multiple sections, such as a fan section, a compressor section, a combustor section, a turbine section, and an exhaust section. Air moves into the engine through the fan section. Airfoil arrays in the compressor section rotate to compress the air, which is then mixed with fuel and combusted in the combustor section. The products of combustion are expanded to rotatably drive airfoil arrays in the turbine section. Rotating the airfoil arrays in the turbine section drives rotation of the fan and compressor sections. The hot gas is then exhausted through the exhaust section.
Some turbomachines include perforated, cylindrical liners. An augmentor liner within the exhaust section is one type of perforated, cylindrical liner. The augmentor liner establishes a passage between an inner cylinder and an outer cylinder. Cooling air, obtained from the compressor or fan, flows through the passage and through perforations within the inner cylinder. The air moving through the passage and through the cylinders facilitates removing thermal energy from this area of the gas turbine engine.
During assembly of the augmentor liner, the surfaces of the inner cylinder that will be exposed to the hot air are typically coated with a thermal barrier coating. The inner cylinder is then laser drilled to create perforations. If the thermal barrier coating extends into the perforations, the thermal barrier coating can block air movement through the perforations.
SUMMARY
An example method of coating a surface includes rotating a sprayer about an axis and directing spray away from the axis using the sprayer. The method coats a surface with the spray. The method moves a fluid through apertures established in the surface to limit movement of spray into apertures. The apertures are configured to direct the fluid toward the axis.
Another example method of coating an inner surface of an annular component includes inserting a sprayer within a bore established by an annular component and coating an inwardly directed surface of the annular component using a spray from the sprayer. The method moves a fluid through perforations established in the inwardly directed surface during the spraying.
An example component having a thermal barrier coating includes an annular component including an inwardly facing surface establishes perforations. A coating is secured to at least a portion of the inwardly facing surface. The inwardly facing surface is configured to direct a fluid through perforations to limit movement of the coating into perforations when spraying the coating against the inwardly facing surface.
These and other features of the disclosed examples can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows an example gas turbine engine.
FIG. 2 shows a perspective view of a radially inner cylinder of an augmentor liner in the FIG. 1 engine.
FIG. 3 shows a schematic end view of the augmentor liner of the FIG. 1 engine.
FIG. 4 shows a close-up view of a portion of the FIG. 3 augmentor liner.
FIG. 5 shows a top view of another example perforation that can be established within the FIG. 3 augmentor liner.
FIG. 6 shows a top view of yet another example perforation that can be established within the FIG. 3 augmentor liner.
FIG. 7 shows a section view at line 7 - 7 in FIG. 6 .
FIG. 8 shows an example of negative flow through perforations in the FIG. 3 augmentor liner.
FIG. 9 shows a close-up view of a portion of the FIG. 3 augmentor liner receiving an angled nozzle.
FIG. 10 shows a top view of an example perforation surrounded by a coating applied with the FIG. 9 nozzle.
DETAILED DESCRIPTION
Referring to FIG. 1 , an example gas turbine engine 10 includes (in serial flow communication) a fan section 12 , a compressor section 14 , a combustor section 16 , a turbine section 18 , and an exhaust section 20 . The gas turbine engine 10 is circumferentially disposed about an engine axis X. The gas turbine engine 10 is an example type of turbomachine.
During operation, air is pulled into the gas turbine engine 10 by the fan section 12 . Some of the air is pressurized by the compressor section 14 , mixed with fuel, and burned in the combustor section 16 . The turbine section 18 extracts energy from the hot combustion gases flowing from the combustor section 16 .
Some of the air pulled into the gas turbine engine 10 by the fan travels along a bypass path 22 rather than entering the compressor section 14 . Air flowing along the bypass path 22 follows a path generally parallel to the axis X of the gas turbine engine 10 .
In the two-spool engine design shown, a portion of the turbine section 18 utilizes the extracted energy from the hot combustion gases to power a portion of the compressor section 14 through a high speed shaft. Another portion of the turbine section 18 utilizes the extracted energy from the hot combustion gases to power another portion of the compressor section 14 and the fan section 12 through a low speed shaft. The examples described in this disclosure are not limited to the two spool architecture described, however, and may be used in other architectures, such as the single spool axial design, a three spool axial design, and still other architectures. That is, there are various types of gas turbine engines, and other turbomachines, that can benefit from the examples disclosed herein.
Referring now to FIGS. 2-4 with continued reference to FIG. 1 , the example exhaust section 20 includes an augmentor liner 23 having a radially inner cylinder 24 and a radially outer cylinder 26 . The radially inner cylinder 24 and the radially outer cylinder 26 are made of an austenitic nickel-chromium-based superalloys or Inconel™ in this example.
A passage 28 is established between the radially inner cylinder 24 and the radially outer cylinder 26 . At least some of the air flowing through the bypass path 22 flows through the passage 28 .
The inner cylinder 24 establishes a plurality of perforations 30 or apertures. The example perforations 30 are laser drilled. In another example, the perforations 30 are formed with rotating drill bits. Only a few perforations 30 are shown for clarity. The inner cylinder 24 typically includes an order of magnitude of 100,000 individual perforations 30 .
Air moving through the passage 28 flows through the perforations 30 toward the axis X of the engine. The air facilitates removing thermal energy from this area of the augmentor liner 23 when the augmentor liner 23 is installed within the engine 10 .
The inner cylinder 24 and the outer cylinder 26 are annular or ring shaped. The passage 28 established between the inner cylinder 24 and the outer cylinder 26 is also annular. The perforations 30 may be formed prior to, or after, shaping the inner cylinder 24 into a cylinder.
The inner cylinder 24 establishes a bore 38 and includes a surface 32 . The surface 32 is concave and faces inwardly toward an axis X 1 . Notably, the axis X 1 of the augmentor liner 23 is coaxial with the axis X of the engine 10 when the augmentor liner 23 is installed within the engine 10 .
As can be appreciated, the surface 32 is exposed to more thermal energy than other areas of the augmentor liner 23 . The surface 32 is coated with a thermal barrier coating 34 to protect the surface 32 , and other portions of the augmentor liner 23 , from thermal energy.
In this example, a sprayer 36 is used to apply the thermal barrier coating 34 to the surface 32 . The coating 34 is a ceramic based coating that is plasma sprayed against the surface 32 . The coating 34 is about 0.005 inches (0.127 millimeters) after curing, for example. Other examples include much thicker coatings.
The sprayer 36 is inserted within the bore 38 when spraying the coating 34 . The sprayer 36 is rotated about the axis X 1 while spraying the thermal barrier coating from a nozzle 44 . The spray from the sprayer 36 is directed away from the axis X 1 toward the surface 32 . The spray includes the coating 34 , which adheres to the surface 32 to coat the surface 32 .
As the sprayer 36 applies the thermal barrier coating, a flow of air 40 (or another type of fluid) is directed through the perforations 30 established in the inner cylinder 24 . The perforations 30 are shaped to promote directed flow coating buildup in one example. For example, a perforation 30 a ( FIG. 5 ) has an hour-glass shape. Another perforation 30 b ( FIGS. 6-7 ) is a heart shaped. Interaction between the thermal barrier coating 34 and the perforation 30 a and 30 b as the thermal barrier coating 34 is applied cause the contours of the thermal barrier coating 34 around perforations 30 a and 30 b to vary. A person having skill in this art and the benefit of this disclosure would be able to vary the shape of the perforations 30 a and 30 b to achieve the desired contours.
The flow of air 40 blocks the thermal barrier coating 34 from entering the perforations 30 as the coating 34 is sprayed and cured. The air 40 is pressurized to 12 psi (0.827 bar) for example. The air 40 is directed through the perforations 30 after applying the thermal barrier coating 34 and before the thermal barrier coating 34 has cured.
In some examples, the air 40 is heated to help prevent adherence. The air 40 could also be cooled. The air 40 also may be cycled with positive and negative flow to create optimal shape of the coating surrounding the perforations 30 . An example of negative flow is shown by the flow of air 40 a ( FIG. 8 ). The negative flow of air 40 a may be utilized to form the thermal barrier coating 34 around the aperture 30 into a desired shape.
In some examples, air is directed radially outboard, rather than radially inboard, through the perforations 30 . The negative flow of air 40 a is one example of radially outboard directed air. In some of these examples, the air 40 a is pressurized on the nozzle side of the inner cylinder 24 to pull and form the thermal barrier coating 34 around the perforations 30 . In such examples, the air 40 may result from a periodic controlled internal explosions, such as a shock pulses, that clear the thermal barrier coating 34 from the perforations 30 .
In some examples, the thermal barrier coating 34 may have partially cured and covered the perforation 30 , and the shock pulse breaks apart the portion covering the perforation 30 . The air 40 or 40 a is pulsed in some examples to fracture thin coating buildup over perforations 30 .
The air 40 may include elements that chemically combine locally with the thermal barrier coating 34 . The chemical combination helps prevent the thermal barrier coating 34 from adhering near the perforations 40 .
Referring again to FIGS. 2-3 , in this example, the perforations 30 are radially aligned such that the perforations 30 direct the air radially toward the engine axis X. Other examples may utilize perforations configured to direct the air in other directions relative to the axis X.
In this example, the sprayer 36 applies the spray to the inner surface 32 prior to installing the augmentor liner 23 within the engine 10 . Accordingly, an air supply 42 is used to supply air that is moved through the passage 28 during the spraying. The air supply 42 communicates air through the passage 28 , which is the same path that air will travel from the bypass path 22 through the perforations 30 when the augmentor liner 23 is installed within the engine 10 .
An example method of thermally protecting the augmentor liner 23 includes spraying the coating 34 against the surface 32 while rotating the sprayer about the axis X and while communicating the flow of air 40 through the perforations 30 .
In one example, the augmentor liner 23 has been used within the engine 10 and already includes a used coating (not shown). In such an example, the used coating may be removed, by a chemical process for example, prior to applying the coating 34 . The example method thus facilitates recoating used augmentor liners and other components.
Although described as coating the augmentor liner 23 , the method could be applied to many other components, such as turbine blades, burner cans, and exhaust cases, for example.
Referring to FIGS. 9 and 10 , in some examples, the nozzle 44 is angled axially during the spraying, which results in shaped application of coating around perforations 30 (teardrops or chevrons as shown in FIG. 10 , etc.) Further, in some examples, the nozzle 44 is angled off-centerline during the spraying, resulting in the profile or the coating having a circumferential feature, which creates a swirl or opposes a swirl in the engine 10 .
Features of the disclosed examples include applying a sprayed coating to a component by rotating a sprayer relative to the concave surface while moving air through perforations in the concave surface to prevent the spray from blocking the perforations. Another feature of the disclosed example is providing the ability to recoat a used component with a thermal barrier coating.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. Thus, the scope of legal protection given to this disclosure can only be determined by studying the following claims.
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An example method of coating a surface includes rotating a sprayer about an axis and directing spray away from the axis using the sprayer. The method coats a surface with the spray. The method moves a fluid through apertures established in the surface to limit movement of spray into apertures. The apertures are configured to direct the fluid toward the axis.
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BACKGROUND
The present techniques relate generally to holographic data storage techniques. More specifically, the techniques relate to methods and systems for dual-beam recording and reading on holographic data storage media or discs.
As computing power has advanced, computing technology has entered new application areas, such as consumer video, data archiving, document storage, imaging, and movie production, among others. These applications have provided a continuing push to develop data storage techniques that have increased storage capacity. Further, increases in storage capacity have both enabled and promoted the development of technologies that have gone far beyond the initial expectations of the developers, such as gaming, among others.
The progressively higher storage capacities for optical storage systems provide a good example of the developments in data storage technologies. The compact disk, or CD, format, developed in the early 1980s, has a capacity of around 650-700 MB of data, or around 74-80 min. of a two channel audio program. In comparison, the digital versatile disc (DVD) format, developed in the early 1990s, has a capacity of around 4.7 GB (single layer) or 8.5 GB (dual layer). The higher storage capacity of the DVD is sufficient to store full-length feature films at older video resolutions (for example, PAL at about 720 (h)×576 (v) pixels, or NTSC at about 720 (h)×480 (v) pixels).
However, as higher resolution video formats, such as high-definition television (HDTV) (at about 1920 (h)×1080 (v) pixels for 1080 p), have become popular, storage formats capable of holding full-length feature films recorded at these resolutions have become desirable. This has prompted the development of high-capacity recording formats, such as the Blu-ray Disc™ format, which is capable of holding about 25 GB in a single-layer disk, or 50 GB in a dual-layer disk. As resolution of video displays, and other technologies, continue to develop, storage media with ever-higher capacities will become more important. One developing storage technology that may better achieve future capacity requirements in the storage industry is based on holographic storage.
Holographic storage is the storage of data in the form of holograms, which are images of three dimensional interference patterns created by the intersection of two beams of light in a photosensitive storage medium. Both page-based holographic techniques and bit-wise holographic techniques have been pursued. In page-based holographic data storage, a signal beam which contains digitally encoded data is superposed on a reference beam within the volume of the storage medium resulting in a chemical reaction which, for example, changes or modulates the refractive index of the medium within the volume. This modulation serves to record both the intensity and phase information from the signal. Each bit is therefore generally stored as a part of the interference pattern. The hologram can later be retrieved by exposing the storage medium to the reference beam alone, which interacts with the stored holographic data to generate a reconstructed signal beam proportional to the initial signal beam used to store the holographic image.
In bit-wise holography or micro-holographic data storage, every bit is written as a micro-hologram, or Bragg reflection grating, typically generated by two counter-propagating focused recording beams. The data is then retrieved by using a read beam to reflect off the micro-hologram to reconstruct the recording beam. Accordingly, micro-holographic data storage is more similar to current technologies than page-wise holographic storage. However, in contrast to the two layers of data storage that may be used in DVD and Blu-ray Disk™ formats, holographic disks may have 50 or 100 layers of data storage, providing data storage capacities that may be measured in terabytes (TB). Further, as for page-based holographic data storage, each micro-hologram contains phase information from the signal.
Although holographic storage systems may provide much higher storage capacities than prior optical systems, they may be vulnerable to poor tracking control due to the presence of multiple layers of data. Accordingly, techniques that improve tracking control of the disc may be advantageous.
BRIEF DESCRIPTION
An aspect of the invention relates to a method of operating a dual-beam detection system for a holographic data storage disc, including: passing a data beam through a first set of optics to a data layer of the holographic data storage disc; passing a tracking beam through a second set of optics to the holographic data storage disc; detecting a reflection of the tracking beam; and synchronizing positioning of the first set of optics with the second set of optics.
An aspect of the invention relates to a a method of operating a dual-beam detection system of a holographic data storage disc, including: impinging a data beam on a data layer of the holographic data storage disc; impinging a tracking beam on a tracking element of the holographic data storage disc; detecting a reflection of the tracking beam from the tracking element; and coordinating position of the data beam relative to the tracking beam.
An aspect of the invention includes a dual-beam detection system of a holographic data storage disc. The system includes a first optical excitation device configured to provide a data beam at a first wavelength to impinge on data layers of the holographic data storage disc; a second optical excitation device configured to provide a tracking beam at a second wavelength to impinge on a servo plane of the holographic data storage disc; and an optical assembly configured to coordinate a position of the data beam with respect to the tracking beam.
DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
FIG. 1 is a schematic diagram of an optical disc reader in accordance with embodiments of the present technique;
FIG. 2 is a top view of an optical disc in accordance with embodiments of the present technique;
FIGS. 3 and 3A are a schematic diagram of a detection head for multilayered optical data storage media;
FIG. 4 is a schematic diagram of a detection head for multilayered optical data storage media in accordance with an embodiment of the present techniques;
FIG. 5 is a schematic diagram of a detection head for multilayered optical data storage media in accordance with an embodiment of the present techniques;
FIG. 6 is a simplified schematic of a detection head for multilayered optical data storage media in accordance with an embodiment of the present techniques; and
FIGS. 7 and 7A are a schematic diagram of the detection head of FIGS. 3 and 3A employing synchronized actuators as discussed with respect to FIG. 4 in accordance with an embodiment of the present techniques.
DETAILED DESCRIPTION
The present techniques are directed to coinciding data layers and a tracking layer in holographic data storage systems. Single-bit holographic data storage records data in a plurality of virtual data layers. Initial recording of these virtual layers of micro-gratings benefits from the recording beams to be precisely positioned with respect to a reference point in the medium and to be generally independent of the possible variations due to disk wobble, vibrations, etc. An approach to link the position of the writing and reading beam to the same volume in the bulk is to use surface relief features, such as grooves similar to those in CD-R and DVD disks. A tracking beam (usually of a different wavelength than the data beam) focused on the grooved layer can generate focusing and tracking error signals employable to lock the position of the objective and the beam on the disk via a feedback servo loop. For a discussion of various aspects of holographic data storage, see U.S. Pat. No. 7,388,695, incorporated herein by reference in its entirety.
Turning now to the drawings, FIG. 1 is an optical reader system 10 that may be used to read data from optical storage discs 12 . The data stored on the optical data disc 12 is read by a series of optical elements 14 , which project a read beam 16 onto the optical data disc 12 . A reflected beam 18 is picked up from the optical data disc 12 by the optical elements 14 . The optical elements 14 may comprise any number of different elements designed to generate excitation beams, focus those beams on the optical data disc 12 , and detect the reflection 18 coming back from the optical data disc 12 . The optical elements 14 are controlled through a coupling 20 to an optical drive electronics package 22 . The optical drive electronics package 22 may include such units as power supplies for one or more laser systems, detection electronics to detect an electronic signal from the detector, analog-to-digital converters to convert the detected signal into a digital signal, and other units such as a bit predictor to predict when the detector signal is actually registering a bit value stored on the optical data disc 12 .
The location of the optical elements 14 over the optical data disc 12 is controlled by a tracking servo 24 which has a mechanical actuator 26 configured to move the optical elements back and forth over the surface of the optical data disc 12 . The optical drive electronics 22 and the tracking servo 24 are controlled by a processor 28 . In some embodiments in accordance with the present techniques, the processor 28 may be capable of determining the position of the optical elements 14 , based on sampling information which may be received by the optical elements 14 and fed back to the processor 28 . The position of the optical elements 14 may be determined to enhance and/or amplify the reflection 18 or to reduce interferences of the reflection 18 . In some embodiments, the tracking servo 24 or the optical drive electronics 22 may be capable of determining the position of the optical elements 14 based on sampling information received by the optical elements 14 .
The processor 28 also controls a motor controller 30 which provides the power 32 to a spindle motor 34 . The spindle motor 34 is coupled to a spindle 36 that controls the rotational speed of the optical data disc 12 . As the optical elements 14 are moved from the outside edge of the optical data disc 12 closer to the spindle 36 , the rotational speed of the optical data disc may be increased by the processor 28 . This may be performed to keep the data rate of the data from the optical data disc 12 essentially the same when the optical elements 14 are at the outer edge as when the optical elements are at the inner edge. The maximum rotational speed of the disc may be about 500 revolutions per minute (rpm), 1000 rpm, 1500 rpm, 3000 rpm, 5000 rpm, 10,000 rpm, or higher.
The processor 28 is connected to random access memory or RAM 38 and read only memory or ROM 40 . The ROM 40 contains the programs that allow the processor 28 to control the tracking servo 24 , optical drive electronics 22 , and motor controller 30 . Further, the ROM 40 also contains programs that allow the processor 28 to analyze data from the optical drive electronics 22 , which has been stored in the RAM 38 , among others. As discussed in further detail herein, such analysis of the data stored in the RAM 38 may include, for example, demodulation, decoding or other functions necessary to convert the information from the optical data disc 12 into a data stream that may be used by other units.
If the optical reader system 10 is a commercial unit, such as a consumer electronic device, it may have controls to allow the processor 28 to be accessed and controlled by a user. Such controls may take the form of panel controls 42 , such as keyboards, program selection switches and the like. Further, control of the processor 28 may be performed by a remote receiver 44 . The remote receiver 44 may be configured to receive a control signal 46 from a remote control 48 . The control signal 46 may take the form of an infrared beam, an acoustic signal, or a radio signal, among others.
After the processor 28 has analyzed the data stored in the RAM 38 to generate a data stream, the data stream may be provided by the processor 28 to other units. For example, the data may be provided as a digital data stream through a network interface 50 to external digital units, such as computers or other devices located on an external network. Alternatively, the processor 28 may provide the digital data stream to a consumer electronics digital interface 52 , such as a high-definition multi-media interface (HDMI), or other high-speed interfaces, such as a USB port, among others. The processor 28 may also have other connected interface units such as a digital-to-analog signal processor 54 . The digital-to-analog signal processor 54 may allow the processor 28 to provide an analog signal for output to other types of devices, such as to an analog input signal on a television or to an audio signal input to an amplification system.
The reader 10 may be used to read an optical data disc 12 containing data as shown in FIG. 2 . Generally, the optical data disc 12 is a flat, round disc with one or more data storage layers embedded in a transparent protective coating. The protective coating may be a transparent plastic, such as polycarbonate, polyacrylate, and the like. In the case of a holographic medium, the material of the disk may be functional that actively changes in response to recording light to produce a data mark hologram. The data layers may include any number of surfaces that may reflect light, such as the micro-holograms used for bit-wise holographic data storage or a reflective surface with pits and lands. The optical disk 12 is mounted on the spindle 36 (see FIG. 1 ) with spindle hole 56 so that the disk may be rotated around its axis. On each layer, the data may be generally written in a sequential spiraling track 58 from the outer edge of the disc 12 to an inner limit, although circular tracks, or other configurations, may be used.
FIGS. 3 and 3A depict an exemplary dual-beam detection head system 60 . A light source 62 emits a read beam 64 at a first wavelength which passes through a polarizing beam splitter 66 and depth selecting optics 68 . The read beam 64 is reflected off a dichroic mirror 70 and directed through the quarter wave plate 72 and the lens 74 to a micro-hologram 76 in the disc 12 . The reflected data beam 78 from the micro-hologram 76 is passed back through the lens 78 , quarter wave plate 72 , dichroic mirror 70 , and depth selecting optics 68 . The reflected beam 78 is then passed through the polarizing beam splitter 66 , collecting optics 80 and detector 82 where the data of the micro-hologram 76 is read.
Further, a light source 84 emits a tracking beam 86 at a second wavelength which passes through a beam splitter 88 and depth selecting optics 90 . The tracking beam 86 passes through the dichroic mirror 70 , quarter wave plate 72 , and the lens 74 to the disc 12 . In the illustrated embodiment, the tracking beam 86 reflects off the disc 12 (e.g., near or at the bottom the disc), which may have a reflective layer, tracks, grooves, and the like. The reflected tracking beam 92 passes through the lens 74 , quarter wave plate 72 , dichroic mirror 70 , collecting optics 90 , beam splitter 88 , and collecting optics 94 to a detector 96 .
In volumetric storage media with a grooved reference plane used for tracking beam positions, one grooved tracking layer is generally sufficient to ensure the positioning of the beam in the medium volume. However, to be able to record multiple layers, the recording and tracking beam focal spots should be separated from each other in depth. When focused on the grooved layer, the tracking beam produces tracking and focusing error signals that facilitate maintaining a repeatable position of the beam with respect to the disk and surface and the track that is being read, generally unaffected by the disk runout. The recording/readout beam should be focused on the virtual data layer in the bulk of the recording medium. To reduce deviations of the reading/writing beam from the track, a favorable scheme would utilize the same objective lens for both tracking and recording/readout beams. This would, in turn, have at least one of the beams to be uncollimated.
However, unfortunately, the relative position of the two focal spots may change when the medium (disc) wobbles around its original position if the objective lens is the only moving element. In other words, the working distance between the lens and medium for a beam focused at a certain depth (layer) is generally independent of the disc position only for a collimated beam. In summary, a focusing servo with a single lens used with a collimated and an uncollimated beam may not ensure that the relative focal spot positions are fixed with respect to each other when a random (unrepeatable) axial runout and/or tilt are present. Different approaches to separating the beam spots in depth may be beneficial.
Using grooved-patterned surface to control focusing and tracking of the objective lens (axial and radial actuator movement), a beneficial design accomodates the objective lens that would separate positions of the focal spots in depth to focus the tracking beam (e.g. red) on the grooved surface, and the recording/readout beam (e.g. green/blue) in the bulk of the medium (disc) on a virtual data layer. With a single-element objective lens, only one collimated beam can typically be used while the other one should be divergent/convergent to focus at a different depth, unless this element is highly dispersive due to the material property or by design. In a more general case, both tracking and data beams may be either convergent or divergent with different divergence cone angles.
Positioning of the read/write beam on a desired data layer and track can be achieved by locking the tracking beam on the groove at the surface (or a special servo-plane) of the disk, while the position of the read/write beam is fixed relative to the tracking beam, and thus to the disk. In order to deterministically write and read data in the volume of the medium when the disk is rotating and wobble and runout occur, the servo system should keep the tracking beam focal spot on the track of the grooved layer, and read/write beams fixed with respect to the tracking beam. This involves axial and radial movements of the optical pickup element (lenses) to follow stochastic changes of the disk position. For a collimated beam, this implies that the distance between the pickup lens and the disk is constant, i.e. the pickup lens will follow the disk movement. When a divergent or convergent beam is focused with the same objective lens, the distance between the focused spot and the lens varies as the lens is moved around to follow the disk wobble.
In one implementation, if the data beam is collimated and the uncollimated beam is used for focusing, the servo loop will keep the focused spot of the tracking beam on the grooved tracking layer of the medium by moving the lens to null the focus error signal (FES). However the distance between the disk and the lens will also change because the conjugate plane of the objective lens is at the finite distance from the lens. This may result in the spot from the collimated data beam to shift with respect to the material of the disk. In another implementation, the tracking beam is collimated so that the servo loop will keep the tracking beam spot on the tracking layer and the distance between the lens and the disk fixed. At the same time, the depth of the data beam spot will vary as the distance between the objective lens and the rest of stationary optics changes.
The present techniques utilize a scheme that may facilitate positioning of the recording beam in the bulk medium at a fixed depth with reduced axial runout. As discussed below, one embodiment utilizes two synchronized actuators to carry two optics elements. Another embodiment employs two different lenses for the tracking and data beams mounted on the same actuator driven by tracking/focusing error signals. Yet another embodiment uses segmented optics and Fresnel-type optics to introduce dispersion into the system and produce different effective focal length of the objective at wavelengths of data and tracking beams. The elements described in the realization may also carry a function of aberration correction for both beams, which could be static or adaptive. Preliminary optical systems modeling shows it is relatively easily realizable for two wavelength system (e.g., 532 nm data and 670 nm tracking beams), i.e., two-color master-slave tracking in single-bit holographic/3D media.
FIG. 4 depicts a dual-beam detection system 110 having synchronized actuators 112 and 114 for a first lens 116 and a second lens 118 . A data beam 120 passes through the second lens 118 , a dichroic beam splitter 122 , and the first lens 116 to a data layer ( 126 ) in the disc 12 . A tracking beam 124 passes through the beam splitter 122 and first lens 116 to a tracking grooved layer in the disc 12 . Of course, additional optics may be included in the system 110 . The data beam 120 and tracking beam 124 are typically of different wavelengths. In the illustrated embodiment, the pair of lenss 116 and 118 may be synchronized in motion with the disc 12 . In this example, both beams 120 and 124 can be used originally collimated. The first lens 116 is the objective lens shared by the beams 120 and 124 .
The tracking beam 120 is focused on and reflected off the tracking grooved layer of the disk. Focusing and tracking error signals may be generated using reflected tracking beam from the grooved surface and fed into the servo that adjusts the position of the first lens 116 to compensate the wobble of the disk 12 . The data beam 124 , in order to be collected at a different depth in the disk 12 (closer to the lens 116 in this example) passes through a second lens 118 , the dichroic beam splitter 122 , and enters the first lens 116 with convergent rays. One of the beams (in this example, the data beam 124 ) enters through both lenses 116 and 118 , while the other beam (e.g., the tracking beam 120 ) enters the system between the two lenses 116 and 118 (via a dichroic beam splitter 122 , etc.) and typically only passes through the objective lens 116 . Thus, advantageously, the focal spots of the two beams 120 and 124 lie at different depths. However, as the disk 12 rotates and wobbles, the depths of the data beam focus spot may wary with respect to that of the reference beam. This will result in a deviation (in depth or laterally) of the focused data beam 124 from the micro-hologram 76 in a data layer 126 that is being read. This deviation can be compensated by a movement of the second lens 118 to follow (with a proper scaling) the movement of the first lens 116 .
In view of the foregoing, the synchronized movement of optics containing uncollimated beams “decouples” the motion of the disc. Both the first and the second lenses 116 and 118 may function as aberration compensating optics for the tracking beam 120 and data beam 124 . The second lens 118 as well as possible additional adaptive optics elements may function also as a working depths selector to address different data layers 126 in the disk 12 . Although only the beam depth compensation was used here as an example, a similar runout compensation in the radial and/or tangential directions may be implemented to compensate the corresponding deviations between the data beam and the tracking beam focus positions.
In another embodiment, FIG. 5 depicts a dual-beam detection system 140 having two lenses 142 and 144 integrated into a single actuator 146 . The system 140 facilitates collimated operation for both the tracking beam 148 and the data beam 150 . In this instance, the pair of discrete lenses or lens assemblies 142 and 144 may be designed respectively for wavelengths/depths of the tracking beam 148 and data (read/write) beam 150 , and which, again, the lenses 142 and 144 are mounted on a common actuator 146 . In the illustrated embodiment, the tracking beam 148 passes through lens 142 to a guide groove on the disc 12 . The data beam 150 passes through the lens assembly 144 to a data layer 126 in the disc 12 . The lens assembly 144 used to focus the data beam 150 may be designed to have an adjustable focus length, as indicated by reference numeral 152 , so that different data layers 126 can be accessed. Of course, additional optics may generally be included that, for example, statically or dynamically compensate aberrations. As the disk 12 rotates and undesirably wobbles, the actuator 146 adjusts the position of both tracking and data optics ( 142 and 144 ) in the same way to accurately follow the reference grooves that facilitates that the data layers and bits are correctly accessed with the data beam 150 . Additional disk tilt detection and feedback can be applied to the moving part of the actuator.
In yet another embodiment, FIG. 6 depicts a dual-beam detection system 160 having a dispersive element 162 . In this example, the dispersive element 162 (e.g., a dye-doped plate with dye distribution profile) is configured to change the focal length of a beam at one wavelength without significantly affecting another beam at a different wavelength. The single-element 162 may exhibit significant dispersion either due to structural design such as Fresnel phase plate, or a dispersive element such as non-uniformly distributed dye or liquid crystal transparent to one of the beams 164 or 166 , but resonantly interacting with the other. In the illustrated embodiment, the tracking beam 164 passes through the dispersive element 162 and lens 168 to a tracking or guide element on the disc 12 . The data beam 166 reflects from a beam splitter 170 , passes through the dispersive element 162 , and lens 168 to data layers 126 on the disc 12 . An actuator 172 facilitates positioning of the system 160 .
In sum, the dispersive element 162 may provide for a highly different refractive index for the tracking beam 164 (e.g., red wavelength) versus the data beam 166 (e.g., green or blue wavelength). Indeed, the element 162 may provide for high chromatic separation. The described dispersive property may be incorporated into the lens 168 . Moreover, the dispersive properties of the dispersive element may be tunable, such as via an electro-chromic effect. Lastly, this example of FIG. 6 may also include additional optics and actuators similar to those, for example, mentioned with respect to FIG. 4 . Such additional optics may facilitate the selecting of different data layers and compensating for the residual runout difference between the data beam and the tracking beam, for example.
FIGS. 7 and 7A depicts the detection head of FIGS. 3 and 3A employing synchronized actuators as discussed with respect to FIG. 4 . A dual-beam detection system 180 having synchronized actuators 182 and 184 is illustrated. A block diagram of a control scheme is also depicted. In this example, the detector 96 that reads the reflected tracking beam 92 feeds a signal to a controller 186 for tracking error, focusing error, and tilt error. The controller 186 provides a control signal an objective actuator driver 188 and also to a depth and tilt correction signal generator 190 . The objective actuator driver 188 controls the actuator 182 , and the depth and tilt correction signal generator 190 controls the actuator 184 . The shared objective lens 74 may incorporate dispersive beam separation as described with respect to FIG. 6 .
While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
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A system and method of operating a dual-beam detection system of a holographic data storage disc, including: impinging a data beam on a data layer of the holographic data storage disc; impinging a tracking beam on a tracking element of the holographic data storage disc; detecting a reflection of the tracking beam from the tracking element; and coordinating position of the data beam relative to the tracking beam.
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BACKGROUND
1. Field of Invention
The present invention relates to power converters, and more particularly, to time-based synchronous rectification in a power converter.
2. Description of Related Art
Power converters are essential for many modern electronic devices. Among other capabilities, power converters can adjust voltage level downward (buck converter) or adjust voltage level upward (boost converter). Power converters may also convert from alternating current (AC) power to direct current (DC) power, or vice versa. Power converters are typically implemented using one or more switching devices, such as transistors, which are turned on and off to deliver power to the output of the converter. Control circuitry is provided to regulate the turning on and off of the switching devices, and thus, these converters are known as “switching voltage regulators” or “switching voltage converters.” The power converters may also include one or more capacitors or inductors for alternately storing and outputting energy.
Switching voltage converters can be used in low power applications such as portable electronic devices (e.g., laptop computers, cell phones, etc.), for example, to convert a voltage at a higher level (e.g., 5V) to a voltage at a lower level (e.g., 1V). To maximize efficiency in switching voltage converters, it is desirable to prevent current from reversing in the output inductor. Reverse current flow at light load degrades efficiency by increasing the RMS current that flows through switching elements and the output inductor. This RMS current causes unnecessary losses.
SUMMARY
According to an embodiment of the present invention, in a power converter system having first and second switches connected in a half-bridge arrangement at a common node from which current flows through an inductor to a regulated output terminal, wherein the regulated output terminal is connectable to a load, wherein the first and second switches are turned on and off in cycles, a method is provided for synchronous rectification. The method includes: initiating a cycle in which the first switch is turned on; developing a timer based on the on-time of the first switch during the cycle; turning off the first switch and turning on the second switch during the cycle; and outputting a control signal to turn off the second switch when either the timer expires or a new cycle is initiated to turn on the first switch, thereby providing synchronous rectification in the power converter system.
According to another embodiment of the present invention, in a DC-to-DC power converter system having first and second switches connected in a half-bridge arrangement at a common node from which current flows through an inductor to a regulated output terminal, wherein the regulated output terminal is connectable to an output capacitor and a load, a method is provided for synchronous rectification. The method includes providing a timing clock signal; starting the timing clock signal when the first switch is turned off; and outputting a control signal to turn off the second switch when either the PWM modulator begins a new cycle to turn on the first switch or when the timing clock signal times out.
According to another embodiment of the present invention, a power converter system includes first and second switches connected in a half-bridge arrangement at a common node. The first and second switches are turned on and off in cycles. An inductor is connected between the common node and a regulated output terminal, which is connectable to a load. A predictive timing circuit is operable to start a timing clock signal when the first switch is turned off after one cycle. The predictive timing circuit is operable to output a control signal to turn off the second switch when either another cycle begins or when the timing clock signal times out.
Important technical advantages of the present invention are readily apparent to one skilled in the art from the following figures, descriptions, and claims.
BRIEF DESCRIPTION OF DRAWINGS
For a more complete understanding of the present invention and for further features and advantages, reference is now made to the following description taken in conjunction with the accompanying drawings.
FIG. 1 is a schematic diagram of a power converter system with time-based synchronous rectification, according to an embodiment of the invention.
FIG. 2A is a schematic diagram of an exemplary implementation of a timer block, according to an embodiment of the invention.
FIG. 2B is a schematic diagram of another exemplary implementation of a timer block, according to an embodiment of the invention.
FIG. 3 is an exemplary state diagram for time-based synchronous rectification, according to an embodiment of the invention.
FIGS. 4A and 4B are exemplary waveform diagrams for time-based synchronous rectification, according to an embodiment of the invention.
DETAILED DESCRIPTION
Embodiments of the present invention and their advantages are best understood by referring to FIGS. 1 through 4B of the drawings. Like numerals are used for like and corresponding parts of the various drawings.
FIG. 1 is a schematic diagram of an implementation of a power converter system 10 with time-based synchronous rectification, according to an embodiment of the invention. Power converter system 10 is a switching regulator and can provide a direct current (DC) power. Power converter 10 can be incorporated in or used with any electronic device in which a DC-to-DC converter as described herein is needed. Power converter system 10 receives an input voltage VIN and provides the DC power to a load at an output terminal VOUT. In one embodiment, power converter system 10 can be a synchronous buck converter which convert a voltage at a higher level (e.g., 5V) to a voltage at a lower level (e.g., 1V). As shown, power converter system 10 includes a power output circuit 12 , a logic and control circuit 14 , an input capacitor 16 , an inductor 18 , and an output capacitor 20 .
The inductor 18 is coupled to the output capacitor 20 at the output terminal of the power converter system 10 . As used herein, the terms “coupled” or “connected,” or any variant thereof, covers any coupling or connection, either direct or indirect, between two or more elements. The power output circuit 12 is coupled to the inductor 18 . Power output circuit 12 may comprise one or more switches 32 which are turned on when the PWM signal of logic circuit 14 is high and turned off when the PWM signal is low to ramp up and down the current of inductor 18 , thereby providing current to the load connected to VOUT and to charge and discharge output capacitor 20 .
In one implementation, as depicted, power output circuit 12 comprises switches 32 , 34 (also referred to as Q 1 , Q 2 ). Switches 32 and 34 are connected at a switching node (SW) in a half-bridge arrangement, with Q 1 switch 32 being the “high-side” switch and Q 2 switch 34 being the “low-side” switch. As the high-side switch, switch 32 may be connected between the input voltage VIN and node SW. As the low-side switch, switch 34 may be connected between the node SW and ground (GND). Each of switches 32 and 34 can be implemented with any suitable device, such as, for example, a metal-oxide-semiconductor field effect transistor (MOSFET), an IGBT, a MOS-gated thyristor, or other suitable power device. Each switch 32 , 34 has a gate to which driving voltage may be applied to turn the switch on or off.
Logic and control circuit 14 is connected to the gates of switches 32 and 34 , and outputs control signals for turning on and off the switches 32 and 34 . When logic and control circuit 14 turns on high-side switch 32 , the power converter system 10 ramps up the inductor current of inductor 18 and charges up output capacitor 20 . When logic and control circuit 14 turns on low-side switch 34 , the power converter system 10 ramps down the current of inductor 18 and discharges output capacitor 20 . The switches 32 and 34 are alternately driven. That is, the high-side switch 32 is not turned on simultaneously with the low-side switch 34 . Low-side switch 34 provides synchronous rectification for power converter system 10 . For synchronous rectification, switch 34 is turned off during the charge cycle for inductor 18 , and turned on during the discharge cycle of inductor 18 .
According to previously developed techniques, the synchronous rectifier in a switching voltage converter is controlled by detecting the inductor current and turning off the synchronous rectifier when the inductor current reaches zero. Detecting the inductor current is typically done by sensing the voltage at the SW node when switch Q 2 is on. This requires a high-speed, very low offset comparator. The demands on the design of that comparator go up as switching frequency increases, and as the RDS(ON) of switch Q 2 is small. In particular, because clock rates have now moved above 10 MHz, the propagation delay of that comparator can create a significant error, reducing efficiency by turning off the synchronous rectifier late.
In various embodiments, the present invention provides a different way to control the synchronous rectifier in a switching regulator. In some embodiments, the invention predicts when the synchronous rectifier (switch 34 ) should be turned off based on the input voltage VIN, the output voltage VOUT, and the on-time of the high-side switch 32 .
Referring again to FIG. 1 , logic and control circuit 14 may include a modulator block 22 , a timer block 24 , a driver block 26 , and a AND gate 28 . Modulator block 22 receives VOUT as a feedback signal. Modulator block 22 outputs a pulse width modulation (PWM) signal, which is provided to driver block 26 . Driver block 26 drives the gate of the high-side switch 32 to turn it on when the PWM signal is high, and off when the PWM signal is low. Implementations for modulator block 22 and driver block 26 are understood to one of ordinary skill in the art. The output signal from driver block 26 is also provided to one input of AND gate 28 . The other input of AND gate 28 is coupled to receive an output signal from timer block 24 . AND gate 28 provides an output signal for driving the gate of low-side switch 34 .
Timer block 24 receives the PWM signal from modulator block 22 . Timer block 24 generally functions to provide or support a timer by which synchronous rectification is controlled, at least in part. In particular, with timer block 24 , logic and control circuit 14 implements a time-based technique for turning off the synchronous rectifier (low-side switch 34 ). In its simplest form, a timer is started when the high-side switch 32 turns off (e.g., the PWM signal goes low). Timer block 24 outputs a signal (Q 2 OFF) which turns off the synchronous rectifier (low-side switch 34 ) when the first of the following two events occurs: (1) a new PWM cycle is begun (e.g., the PWM signal goes high), causing high-side switch 32 to turn on; (2) the timer block 24 expires or times out. The power converter system 10 operates in a single mode at all times, with synchronous rectification based on predictive timing, and does not require sensing the current in the inductor 18 or the voltage on the SW node.
In some embodiments, the timer implemented by timer block 24 may be fixed—i.e., it times out after a predetermined period of time.
In other embodiments, the timer can vary, for example, as a function of the time that the high-side switch 32 is turned on during the relevant cycle. Such embodiments take advantage of the fact that the slope of the current through the inductor 18 is a function of VIN and VOUT. The modulator block 22 determines or derives the on time (T ON ) for the high-side switch 32 . The low-side switch 34 (i.e., the synchronous rectifier) turns on when the high side switch 32 turns off, and turns off either when PWM signal goes high or when timer block 24 times out. The time that timer block 24 expires can be set to correspond to the time that it takes to discharge the current that was built up when the high-side switch 32 was on.
In particular, for the latter embodiments, to develop the timing signal, the following relationships are observed.
The duty cycle (D) of a buck converter is based on the ratio of VIN and VOUT:
D ≅ V OUT V IN ( 1 ) T O N = D · T S W = D F S W ( 2 ) T O F F = ( 1 - D ) · T S W ( 3 )
where F SW is the switching frequency and T SW is the switching period. The change inductor current (ΔI) during the T ON is:
Δl
=
V
L
(
O
N
)
T
O
N
≅
V
IN
-
V
OUT
T
ON
(
4
)
The inductor current change (ΔI) during the T OFF is:
Δl
=
V
L
(
OFF
)
T
OFF
≅
V
OUT
T
OFF
(
5
)
Thus, in some embodiments, the timer of timer block 24 times out or ends when the volt-seconds of T OFF equals the volt-seconds of the preceding T ON . As such, embodiments of the invention may implement a technique to turn off the synchronous rectifier (low-side switch 34 ) based on a volt-second balance (time) for synchronous buck converters. This may have the effect of causing almost no extra dead-time during steady-state and only small increases in dead-time during transients.
Embodiments of the invention can provide for low-power operation. The embodiments may also make facilitate or allow low power operation of a power converter or regulator at high frequencies.
In various embodiments, all or a portion of power converter system 10 can be implemented on a single or multiple semiconductor dies (commonly referred to as a “chip”) or discrete components. Each die is a monolithic structure formed from, for example, silicon or other suitable material. For implementations using multiple dies or components, the dies and components can be assembled on a printed circuit board (PCB) having various traces for conveying signals there between. In one embodiment, power output circuit 12 is implemented on one die, logic and control circuit 14 is implemented on another die, and the input capacitor 16 , inductor 18 , and output capacitor 20 are discrete components.
FIG. 2A is a schematic diagram of an exemplary implementation of a timer block 24 , according to an embodiment of the invention. As shown, timer block 24 includes a one shot circuit 40 , a capacitor 42 , switches 44 , 45 , current sources 46 , 48 , and a comparator 50 .
As shown, in one implementation, the timing function for turning off the synchronous rectifier (i.e., low-side switch 34 ) can be accomplished by charging and discharging capacitor 42 , which functions as a timing capacitor for timer block 24 . When the PWM signal is high, switch 44 is closed, and capacitor 42 is charged with a current proportional to VIN−VOUT. When the PWM signal is low, switch 44 is open, and capacitor 42 discharges with a current proportional to VOUT. Capacitor 42 may be connected at a ramp node to the current sources 46 , 48 . In this implementation, current source 46 provides a switched charging current (with a magnitude of K*VIN), and current source 48 provides a constant discharging current (with a magnitude of K*VOUT) for discharging capacitor 42 . Thus, when switch 44 is closed, capacitor 42 is charged with the difference in current between the two current sources 46 and 48 (or K*VIN−K*VOUT or K*(VIN−VOUT)); and when switch 44 is open, capacitor 42 discharges with current source 48 only (or K*VOUT). Switch 44 is controlled by the modulator block 22 , and is closed when PWM signal is high, which produces a waveform on capacitor 42 that has the same timing and magnitude as the inductor current.
For consistent timing, cycle to cycle, of the waveform of capacitor 42 , switch 45 resets the voltage on capacitor 42 to VREF at the start of each PWM period. The reset timing for switch 45 is determined by one shot circuit 40 , which produces a short duration switch control signal (RST) which momentarily closes switch 45 . In addition to resetting the capacitor 42 , the width and duration of the RST signal can affect the timing of the turnoff of the synchronous rectifier (low-side switch 34 ), ensuring, for example that switch 34 will turn off slightly before the inductor current returns to the current that was flowing before switch 34 turned on. This will affect the dead-time of power converter system 10 when the current through inductor 18 is positive at the end of the PWM cycle. For example, in one embodiment, a long duration for the RST signal will result in an increase in the dead-time. A short duration for the RST signal will result in an decrease in the dead-time. Eliminating or reducing the deadtime can be accomplished in a variety of ways, including adding hysteresis to comparator 50 , adding an offsetting one-shot pulse after comparator 50 goes high to increase its time by a similar amount of time as the RST pulse, or increasing the “K” multiplier of current source 46 with respect to the “K” multiplier of current source 48 .
Comparator 50 compares the voltage at the ramp node (which is the voltage on the capacitor 42 ) against a reference voltage (VREF). When the voltage at the ramp node is below VREF, the comparator 50 outputs a signal to turn off the synchronous rectifier (low-side switch 34 ).
FIG. 2B is a schematic diagram of another exemplary implementation of a timer block 24 , according to an embodiment of the invention. As shown, timer block 24 includes a one shot circuit 40 , a capacitor 42 , a resistor 54 , and a comparator 52 . In this embodiment, the timing capacitor 42 of the timer block 24 is charged from the SW node through resistor 54 , instead of by reference voltage VREF. The timing capacitor 42 is set to VOUT during reset.
FIG. 3 is an exemplary state diagram 60 for time-based synchronous rectification, according to an embodiment of the invention. In one embodiment, the state diagram 60 can be implemented in power converter system 10 . As shown, the state diagram 60 has three states: first state 62 , second state 64 , and third state 66 .
In the first state 62 , high-side switch 32 (Q 1 ) is turned on, the current in inductor 18 is increasing, and low-side switch 34 (the synchronous rectifier or Q 2 ) is turned off. In this state, capacitor 42 (connected at the ramp node in timer block 24 ) is charging up. This can be accomplished with current source 46 . Capacitor 42 charges up while the PWM signal is high, which turns on the high-side switch 32 . From the first state 62 , power converter system 10 can move to second state 64 . This occurs when the PWM signal goes low, thus turning off the high-side switch 32 and turning on the low-side switch 34 .
In the second state 64 , high-side switch 32 (Q 1 ) is turned off, and low-side switch 34 (the synchronous rectifier or Q 2 ) is turned on. In this state, capacitor 42 (connected at the ramp node in timer block 24 ) is discharging. This can be accomplished with current source 48 . From the second state 64 , can move either to the first state (when the PWM signal goes high) or to the third state 66 (when the voltage at the ramp node equals the reference voltage (VREF). In other words, power converter system 10 remains in the second state 64 until either the high-side switch 32 is turned on or the timer of timer block 24 expires or times out. Since the capacitor 42 was charged with a slope proportional to the upslope of the inductor current during the first state 62 , and discharged with a slope proportional to the downslope of the inductor current during the second state 64 , then if the transition out of the second state 64 occurs due to the timer expiring, the current through inductor 18 of power converter system 10 will have returned to its starting value—i.e., the current should have a magnitude approximately equal to what it was at the time that power converter system 10 entered the first state 62 .
In the third state 66 , both the low-side switch 34 (the synchronous rectifier or Q 2 ) and the high-side switch 32 (Q 1 ) are turned off. From the third state 66 , power converter system 10 can move to the first state 62 when the PWM signal goes high, thus turning on the high-side switch 32 .
The operation of power converter system 10 with time-based synchronous rectification can be further understood with reference to FIGS. 4A and 4B , which are exemplary waveform diagrams 100 and 200 for the system 10 , according to an embodiment of the invention.
Referring to FIG. 4A , waveform diagram 100 has waveforms 102 , 104 , 106 , 108 , 110 , 112 , and 114 which generally represent, respectively, the current flowing in inductor 18 , the voltage of capacitor 42 at the RAMP node (compared against reference voltage (VREF)), the RST signal (from one shot circuit 40 ), the PWM signal output from modulator block 22 , the turn-off of the low-side switch 34 (synchronous rectifier Q 2 ), the turn-on of the high-side switch 32 (Q 1 ), and the turn-on of the low-side switch (Q 2 ).
FIG. 4A illustrates the case in which the synchronous rectifier (low-side switch 34 or Q 2 ) is turned off (waveform 110 ) due to the timer of timer block 24 expiring. Here, the RAMP time-out (which occurs when the voltage of the capacitor has discharged to the magnitude of VREF) causes the synchronous rectifier to turn off and also causes the RST signal to go high, which holds the RAMP voltage at VREF by closing switch 45 . The PWM pulse (waveform 108 ) output from modulator block 22 goes high some time after the RAMP signal returns to VREF (waveform 104 ). This would be the case when the power converter system 10 is lightly loaded, and the modulator block 22 is required to provide a lower duty cycle (shorter ON times for high-side switch 32 ).
Referring to FIG. 4B , waveform diagram 200 has waveforms 202 , 204 , 206 , 208 , 210 , 212 , and 214 which generally represent, respectively, the current flowing through inductor 18 , the voltage of capacitor 42 at the RAMP node (compared against the reference voltage (VREF)), the PWM signal output from modulator block 22 , the RST signal (from one shot circuit 40 ), the turn-off of the low-side switch 34 (synchronous rectifier or Q 2 ), the turn-on of the high-side switch 32 (Q 1 ), and the turn-on of the low-side switch (Q 2 ).
FIG. 4B illustrates the case in which the synchronous rectifier (low-side switch 34 ) is turned off (waveform 210 ) due to the turn on of the high-side switch 32 (waveform 212 ) and before the expiration of the timer of timer block 24 . Here, the PWM pulse (waveform 206 ) output from modulator block 22 arrives before the RAMP signal returns to VREF (waveform 204 ). This causes the high-side switch 32 (Q 1 ) to turn on (waveform 212 ), and the low-side switch 34 (Q 2 ) to turn off (waveforms 210 and 214 ).
Thus, predictive timing for the control of the synchronous rectifier may allow for almost no extra dead-time during steady-state operation of power converter system 10 and only small increases in dead-time during transients.
As discussed herein, in one embodiment, the present invention turns off the low-side switch or synchronous rectifier in switching voltage converter based on a predictive timing circuit. The timing circuit eliminates the need to sense the inductor current, or the voltage across the low-side switch to determine when to turn off the synchronous rectifier.
In one implementation, this is accomplished by charging a capacitor with a current proportional to the input voltage minus the output voltage (VIN−VOUT) and discharging the same capacitor with a current proportional to VOUT. The low-side switch is turned off when the capacitor voltage during discharge crosses the voltage reference at which that the capacitor started during charge. A short reset (RST) pulse ensures both that the ramp will not start charging for a fixed period of time, and that the capacitor's starting voltage will be a known DC voltage reference (VREF). The RST pulse has the effect of producing a pre-bias which ensures that the synchronous rectifier will turn off during the cycle while a small positive current is flowing in the inductor. Increasing the width of RST pulse can result in a corresponding increase in the amount of current conducted by the body diode when the inductor current is positive at the end of the PWM cycle. The inaccuracy of the turn-off point due to the dead-time can be eliminated by various techniques including changing the relative strength of the charge and discharge currents, or adding positive offset to VREF during the time when the synchronous rectifier is on.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims. That is, the discussion included in this application is intended to serve as a basic description. It should be understood that the specific discussion may not explicitly describe all embodiments possible; many alternatives are implicit. It also may not fully explain the generic nature of the invention and may not explicitly show how each feature or element can actually be representative of a broader function or of a great variety of alternative or equivalent elements. Again, these are implicitly included in this disclosure. Where the invention is described in device-oriented terminology, each element of the device implicitly performs a function. Neither the description nor the terminology is intended to limit the scope of the claims.
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In one embodiment, in a power converter system having first and second switches connected in a half-bridge arrangement at a common node from which current flows through an inductor to a regulated output terminal, wherein the regulated output terminal is connectable to a load, wherein the first and second switches are turned on and off in cycles, a method is provided for synchronous rectification. The method includes: initiating a cycle in which the first switch is turned on; developing a timer based on the on-time of the first switch during the cycle; turning off the first switch and turning on the second switch during the cycle; and outputting a control signal to turn off the second switch when either the timer expires or a new cycle is initiated to turn on the first switch, thereby providing synchronous rectification in the power converter system.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of application Ser. No. 11/951,617, filed Dec. 6, 2007, which is a continuation-in-part of application Ser. No. 11/769,879 filed Jun. 28, 2007, which is a continuation-in-part of application Ser. No. 11/476,474, filed Jun. 28, 2006.
BACKGROUND OF THE INVENTION
[0002] The present invention pertains light weight open core materials having a honeycomb-like structure useful in a number of applications where light weight core elements are desirable or necessary.
[0003] It has long been known to utilize honeycomb core materials in the manufacture of structural members such as doors, wall panels and floor panels. The honeycomb core material may be made from paper, metal or even plastic web material. Conventional honeycomb construction may utilize paper strips laid together in a stack and connected to one another with intermittent lengths of adhesive, and then expanded or opened to form a hexagonal honeycomb core element. It is also known to use corrugated paper or metal webs either with or without smooth facing webs which are stacked and glued together, again resulting in an open core structure.
[0004] Although honeycomb-type core elements have long been proposed for use in structural panels, one reason for the lack of significant development of this use is the absence of a high speed process for making and assembling multi-layer honeycomb core elements. Also, when open core elements are made with conventional corrugated paper webs, conventional corrugating techniques and machinery are typically limited to flute sizes that are unnecessarily small for making open core elements for use in structural members. The inability to control thickness as well as the width of the expanded core material has been a problem.
SUMMARY OF THE INVENTION
[0005] The present invention comprises a fully automated and highly productive method and apparatus for the continuous manufacture of open core elements using fluted web material of various kinds and with or without intermediate smooth web materials.
[0006] In accordance with one embodiment of the present invention, an apparatus for forming large pitch fluted web uses a rigid fluted rotary roll that has flute teeth defined by adjacent tips and gullets and spaced circumferentially at the desired flute pitch. A counterroll uses parallel fluting bars that are circumferentially spaced at the flute pitch and have fluting tips that extend into the gullets of the fluting roll teeth for fluting engagement with the fluting roll. The counterroll has a rigid cylindrical core and an outer elastomer sleeve in which the fluting bars are embedded and held to permit individual fluting tips to move in response to cyclically varying force as a result of fluting tip contact with the teeth of the fluting roll. The fluting roll teeth are generally V-shaped in cross section and the tooth gullets and tips have a circular cross section and are interconnected by flat tooth flanks. The fluting tips of the counterroll fluting bars have a radius slightly less than the radius of fluting roll tooth gullets and, preferably, the radius of the fluting tips is less than the radius of the tooth gullets by an amount approximately equal to the thickness of the web being processed.
[0007] With the narrow construction of the fluting bars, contact with the fully formed web flutes occurs only in the flute gullets of the fluting roll. Correspondingly, there is no contact between the fluting roll flute tips and the flute flanks of the counterroll teeth.
[0008] The fluting roll, which is typically larger in diameter than the counterroll, has a cylindrical tubular body in which is formed a series of circumferentially spaced axial bores which may be used to supply vacuum and/or heat to the roll. The vacuum system helps bring the fluted web into full contact with the fluting roll tooth gullets and hold the fluted web in contact with the corrugating roll for continued processing. The heat which is preferably derived from steam assists in web conditioning, flute formation and setting and drying of the adhesive.
[0009] In a preferred embodiment of the present invention, the method and apparatus for forming a large pitch fluted web, as described herein, is applied to the formation of a composite double medium, single liner fluted web using two pairs of a fluting roll and counterroll operated in tandem and with the fluted rolls in register. In accordance with the method of this embodiment, formation of the composite web includes the steps of (1) positioning a pair of fluted rolls, each of which has axially extending teeth that are defined by adjacent tips and gullets spaced circumferentially at a given pitch, with the rolls in counter-rotating closely spaced relation and the teeth in register to form a nip between the fluted rolls, (2) for each fluted roll, positioning a counterroll that has axially extending fluting bars spaced at the flute pitch, the bars having tips that extend into counter-rotating engagement with the gullets of the fluted roll to form a fluting nip, (3) directing a web into each fluting nip to form a fluted medium web, (4) retaining the fluted mediums on their respective fluted rolls, (5) applying an adhesive to the tips of each fluted medium web while the web is retained on the fluted rolls, (6) bringing a liner web into contact with one of the fluted medium webs on its fluted roll, and (7) bringing the liner web into contact with the other fluted medium web in the nip formed by the fluted rolls to form the composite double medium, single liner fluted web.
[0010] The foregoing method may be advantageously applied to form small light weight packing elements by performing the additional steps of (1) using paper for the webs, (2) slitting the composite paper web in the direction of web travel into narrow parallel strips, and (3) cutting the strips into short length pieces on lateral cut lines in the gullets of the medium webs. Preferably, the cutting step comprises die cutting.
[0011] The method of forming a composite double medium, single liner fluted web, described above, may also include the steps of (1) heating the fluted rolls, and (2) applying a vacuum to the gullets of the fluted rolls along circumferential portions of said rolls on which the fluted medium webs are carried. The method may also include the step of embedding the ends of the fluting bars opposite the tips in an elastomer layer that is formed on the outer surface of the counterroll. The method may further include the step of retaining the composite web on one of the fluted rolls downstream of the nip.
[0012] Another embodiment of the present invention comprises an alternate method for the manufacture of open core elements. The method comprises the steps of (1) forming two composite web halves, each comprising a smooth web and a fluted web, (2) orienting the composite web halves with the exposed fluted web flutes facing up, (3) applying an adhesive to the exposed flute tips of one web half, (4) adhering the other web half by its smooth web to the glued flute tips of said one web half to form an open face double wall web, (5) slitting the open face double wall web longitudinally to form a plurality of adjacent equal width open face double wall strips, (6) applying an adhesive to the exposed flute tips of said open face double wall strips, (7) cutting the strips transversely to a common selected length, (8) separating the strips in a lateral direction, (9) conveying each strip in the lateral direction individually and serially into a vertical stacker, (10) dropping each strip vertically in the stacker such that each strip, after the lead strip, is deposited on the glued flute tips of the preceding strip to form an intermediate open core block of strips, (11) upending the intermediate block onto a lateral block edge to orient the exposed glued flute tips of the last deposited strip to face in the lateral downstream direction, and (12) conveying the intermediate block in the lateral downstream direction to bring the exposed glued flute tips into bonding contact with the exposed smooth web face of a preceding intermediate block to form the open core element.
[0013] The foregoing method preferably includes, prior to the step of adhering one web half to the other web half, the step of aligning the flute tips of the web halves tip-to-tip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of a system for the continuous manufacture of open core elements utilizing one embodiment of the method of the present invention.
[0015] FIG. 2 is a top plan view of the system shown in FIG. 1 .
[0016] FIG. 3 is a perspective view of an upstream portion of the FIG. 1 system showing one embodiment of an apparatus for forming the composite web.
[0017] FIG. 4 is a perspective view of an intermediate downstream portion of the system showing the incremental formation of core elements.
[0018] FIG. 5 is a perspective view of the downstream portion of the system shown in FIG. 1 .
[0019] FIG. 6 is a perspective view of an apparatus for forming an all-fluted composite web.
[0020] FIG. 7 is a side elevation detail of an alternate flute forming apparatus of a presently preferred construction.
[0021] FIG. 8 is a perspective view of an alternate system for the manufacture of open core elements.
[0022] FIG. 9 is a perspective detail of a portion of the system shown in FIG. 8 .
[0023] FIG. 10 is a further perspective detail of the system shown in FIG. 8 .
[0024] FIG. 11 is a side elevation detail of a preferred embodiment of an upender used in the method of the present invention.
[0025] FIGS. 12-14 are cross sectional details of the progressive formation of an open core element from its component webs.
[0026] FIG. 15 is an end view of the web fluting apparatus of a presently preferred embodiment.
[0027] FIG. 16 is an enlarged view of a portion of FIG. 15 .
[0028] FIG. 17 is a view similar to FIG. 16 showing the fluting progression of the interacting fluting rolls.
[0029] FIG. 18 is a perspective view of a glue machine for applying a liquid adhesive to a fluted web.
[0030] FIG. 19 is a schematic top plan view of the glue machine of FIG. 18 .
[0031] FIG. 20 is an end view of the web fluting apparatus shown in FIG. 15 used to form a single face fluted web.
[0032] FIG. 21 is an end view of an apparatus using two pairs of the web fluting apparatus of FIG. 20 to form a composite double medium, single liner fluted web.
[0033] FIG. 22 is a perspective view of a small packing piece cut from the composite double medium, single liner fluted web shown in FIG. 21 .
[0034] FIG. 23 is a perspective view of a modified apparatus for making open core elements.
[0035] FIG. 24 is a plan view showing the application of the core elements made in the FIG. 23 apparatus to make an open core panel.
[0036] FIG. 25 is a top plan view of the downstream portion of a modified system for making open core elements.
[0037] FIGS. 26 and 27 show operation of the FIG. 25 system in the respective formation and transfer modes for intermediate open core elements.
[0038] FIG. 28 is a generally schematic top plan view of the entire system for FIGS. 25-27 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Referring initially to FIGS. 1 and 3 , a core element lay up system 10 utilizes core element components made from a composite web 11 which is converted to form strip like elements ( 28 ) which are, in turn, joined to form a core element 13 . In the embodiment of the invention shown, a double width composite web 11 is formed by joining a smooth web 14 and a fluted web 15 utilizing any of a number of prior art techniques. For example, the webs 14 and 15 could be formed and glued together in a single facer 16 in a manner well known in the corrugating industry. A smooth web from a supply roll 17 is fluted under heat and pressure in the single facer 16 , glue is applied to the flute tips on one side of the fluted web 15 , and the fluted web is then joined to the smooth web 14 from the supply roll 18 .
[0040] The composite web 11 is formed (or reoriented after forming) with the fluted web component 15 facing upwardly. As the composite web 11 exits the single facer 16 , it is slit longitudinally on its centerline by a slitting blade 20 to form two web halves 21 and 22 . A suitable glue or adhesive is applied to the flute tips of the lower web half 21 by a glue roll 23 . The other web half 21 is directed onto an angled turning bar 24 around which it is wrapped and displaced laterally to bring it into contact with the glued web half 21 where the smooth web face of the web half 22 is laid onto the glued flute tips of the other web half 21 to form an open face double wall web 25 . The double wall web 25 is directed over a heating plate 26 or other heating device to cure the adhesive and permanently join the two web halves 21 and 22 . As will be described in greater detail below with respect to the presently preferred embodiment, the flutes of the two component webs forming the open face double wall web 25 are brought together and joined so that the flutes of the two component webs are in flute tip-to-flue tip alignment.
[0041] The open face double wall web 25 is then slit longitudinally with a multi-blade slitter 27 to form a plurality of equal width open face double wall strips 28 . The open face double wall web 25 has an upper exposed fluted face and, therefore, the strips 28 also have laterally extending flutes. The strips then pass beneath a second glue roll 30 which applies a suitable adhesive to the exposed flute tips. When the plurality of strips 28 reaches a selected length in the machine direction, a cut-off knife 31 downstream of the glue roll cuts the strips 28 to a common length. The strips are preferably cut at the bottom of the next flute which will provide a core element just slightly larger than the desired length. The plurality of glued and cut strips 32 is accelerated on a transport conveyor 33 to form a gap between the strips and the next-following uncut strips.
[0042] The plurality of glued and cut strips 32 is then cross-transferred out of the machine direction path of the next following plurality of strips and onto a lateral feed conveyor 34 to a strip upender 35 . As is best seen in FIG. 4 , an upender roll 36 has a series of circumferentially spaced vacuum headers 37 that serially capture each glued and cut strip to reorient the strip from a horizontal to a vertical position such that succeeding strips are deposited on common lateral strip edges and in face to face relation with each strip that precedes it. In this orientation, the glued flutes of each strip face the smooth web face of the preceding strip and, when deposited on the element forming conveyor 38 , are brought into adhesive contact. As can be seen in FIG. 4 , the flutes on the strips extend vertically and together comprise a core element 13 . To facilitate removal of each strip 28 from the vacuum header 37 on the upender roll 36 , each vacuum header includes a series of laterally spaced vacuum ports between which the tines of a discharge fork 40 extend. The fork is operable to engage the unglued smooth face of each strip and push it into contact with the preceding strip on the element forming conveyor as the vacuum is released. The discharge fork is then returned to its discharge position for the next following strip.
[0043] In this embodiment, as the core element 13 is being formed, a set of conveyor belts 41 , positioned over the top of the core element, applies a normal force to assist in compacting the core element and press the glued flute tips of each strip to the smooth face of the preceding strip by running slightly faster than the advancing core block which is held back by downstream holding rolls.
[0044] When a core element 13 comprising a desired number of strips has been formed, the core element 13 is accelerated into a trim and cut station where it can be cut into any number of smaller core elements. In the example shown in FIG. 5 , the large formed core element 13 is trimmed longitudinally (in the longitudinal direction of the strips 28 ) with a trim blade 42 to a selected edge dimension. The trimmed element 13 is then moved to a cutting position where a series of cutting blades 43 , including an edge trim blade, cuts the long core element into final element sizes. For example, if the final core elements are to be used in the manufacture of hollow-core doors, the strips 28 could be cut to lengths of 240″, upended and stacked to a core width of 30″ and finally trimmed and cut to provide three door pieces each 80″×30″.
[0045] The height or thickness of the core element 13 depends on the width to which the strips 28 are slit. The length of the core element 13 can be varied as desired. Thus, the system has the capability of continuously and rapidly forming core elements of widely varying dimensions.
[0046] Composite fluted webs, useful in forming core elements, can be made in a number of different ways, can utilize different kinds of web materials, and the fluted web can be formed in various ways. As indicated above, it is preferable to utilize a flute size for the fluted web that is larger than flutes commonly made on a typical single facer. A larger flute size will provide adequate strength for the core element, but utilize significantly less paper or other web material in the formation of the fluted web.
[0047] Referring to FIG. 6 , an alternate apparatus utilizing an alternate flute forming method is shown. In the embodiment shown, a composite web is made by simultaneously fluting two incoming webs which may be made of the same or different materials. If, for example, two paper webs are utilized, an upper web 44 has a layer of glue, such as a starch adhesive, applied to its lower face upstream of a fluting nip 45 . A lower web 46 is also fed with the glued upper web 44 into the nip 45 formed at the upper and lower tail sprockets 47 and 48 carrying a pair of intermeshing fluting conveyors 50 and 51 . Each of the fluting conveyors 50 or 51 includes a continuous series of fluting bars 52 made, for example, from aluminum extrusions and extending the full width of the incoming webs 44 and 46 (e.g. 96″ or about 2440 mm). The fluting bars may be carried on a series of laterally spaced ¾″ pitch roller chains with the fluting bars 52 attached thereto with conventional K- 1 attachments. The roller chains may, for example, be laterally spaced 16″ or about 406 mm apart. Each fluting bar has an exposed flute forming tip 53 that is shaped to form a flute one 12″ (about 13 mm) deep and with a pitch of ¾″ (about 19 mm) corresponding to the pitch of the carrying roller chains.
[0048] As the webs 44 and 46 come into the fluting nip 45 , they are simultaneously fluted, one flute at a time, and joined by the adhesive previously applied to the contacting face of one of the webs. The joined webs are held together in a straight fluting run 54 of the fluting conveyors 50 and 51 to which heat is applied by upper and lower heating elements 50 and 51 to bond and cure the adhesive. Each of the fluting conveyors 50 and 51 may include flute pre-heaters 57 to help maintain the temperature of the fluting bars 52 . A composite fluted web 58 exits the fluting conveyors 50 and 51 at their head ends where, preferably, the conveyor flights are separated gradually on a much larger radius arc than that of the tail sprockets 47 and 48 . The resulting composite fluted web 58 is substantially cured and rigid enough for further processing with or without the addition of a smooth facing web.
[0049] A composite fluted web 58 of the foregoing type could, for example, be glued to a smooth web and the web processed to form core elements in the manner previously described. However, the composite fluted web 58 also has utility for other applications, such as a substitute for the ubiquitous styrofoam peanuts used as packaging filler and cushioning material.
[0050] An alternate apparatus for forming a fluted web is shown schematically in FIG. 7 . In this embodiment, a lower fluting conveyor 75 is similar to the fluting conveyor 51 of the FIG. 6 embodiment. The flute bars 76 are heated and, in addition, are provided with a vacuum system enabling the formed flutes to be drawn into the valleys between the flute bars. In lieu of an upper fluting conveyor, a spoked fluting roll 77 is used. The fluting roll is provided with a plurality of circumferentially spaced spokes 78 which press the incoming web one flute at a time into the fluting conveyor 75 where the applied vacuum holds the web in position. If two webs of paper or other materials are joined as described with respect to the FIG. 6 embodiment, the vacuum and heat applied to the web downstream of the fluting roll 77 will cure the composite web resulting in a composite fluted web cured and rigid enough for further processing the exposed flutes of the upper web may have an adhesive applied by a downstream glue roll 80 for the addition of a smooth facing web.
[0051] Although a single wall composite web, having one fluted web and one smooth web, can be utilized in the overall process of the present invention, it is preferable to use an open face double wall web such as web 25 used in the process described with respect to FIGS. 1-5 . In that process, a full width single face web is slit on its center line and one of the slit halves is turned and moved laterally on a turning bar to be joined with the other web half. However, an open face double wall web may also be formed by joining two full width single face webs each formed on a separate single facer, as will be described in the following preferred embodiment. Regardless of how an open face double wall web is formed, it is important in order to maximize the strength of the core elements to be formed to align the flutes in the joined single face webs so that they are in alignment flute tip-to-flute tip in the double wall web. On the other hand, if a more springy cushioning effect is desired in a core element, the flutes in the two component single face webs may be aligned one half pitch from flute-to-flute alignment or such that the flutes of one composite single face web align with the valleys of the other composite single face web.
[0052] Another embodiment of a system for carrying out the process for the continuous manufacture of open core elements is shown in FIGS. 8-11 . The incoming web 60 from the upstream single facer or single facers 59 and 61 may be open face single wall or open face double wall, the later being either full width or half width. Preferably, however, for the reasons stated above, the incoming web 60 is an open face double wall web. A pair of single facers 59 and 61 (or fluted web forming apparatus of FIGS. 6 or 7 ) provide an upper fluted single face web 81 (see the FIG. 12 detail) with its smooth web on the bottom and is joined to a lower fluted single face web 82 ( FIG. 12 detail) to the exposed flute tips of which an adhesive has been applied with a glue roll 83 . The resulting composite open face double wall web 60 (see the FIG. 13 detail) is heated and cured and brought into the lay-up portion of the system for further processing.
[0053] The web 60 is slit in a multi-blade slitting knife 62 into open face double wall strips 63 with the flutes oriented upwardly. As with the previously described process and methods, the width of the strips 63 determines the height or thickness of the finished open core elements. The strips 63 move from the slitting knife under a glue roll 64 where glue is applied to the exposed flute tips. However, in this embodiment one strip is left unglued. The unglued strip 65 may be provided in a number of ways, such as using a laterally movable scraper blade operatively engaging the glue roll to prevent glue from being applied to the unglued strip 65 . Successive unglued strips 65 are placed among the strips exiting the glue roll to space between them a selected number of glued strips 63 desired in the finally formed core element. Thus, the unglued strips 65 may not always be in the same lateral position on the strips exiting the glue roll 64 because the desired core element may utilize more or less than the total number strips 63 slit from the incoming web 60 .
[0054] Each group of strips 63 exiting the glue roll is accelerated on a speed-up conveyor 66 to separate the strips from the next incoming group of strips. The strip group 68 is then cross-transferred onto a lateral feed conveyor 67 where each of the strips now extends laterally across the feed conveyor 67 . At the downstream end of the lateral feed conveyor 67 , a strip upender 35 identical to the one described with respect to the preceding embodiment, operates to sequentially reorient each strip 63 from a horizontal to a vertical position. Each reoriented strip is positioned with its glued flute tips extending vertically and facing in the downstream direction and is brought into contact with the smooth web on the back of the preceding strip 63 .
[0055] Referring to FIGS. 8-11 , each unglued strip 65 forms the lead strip of a hollow core element 70 (see the FIG. 14 detail) of a desired size. The unglued lead strip 65 , after it is upended, is brought into contact with a toothed gate 71 operating between the strip upender 35 and the upstream end of an element forming conveyor 72 . When a hollow core element 70 is formed, the toothed gate 71 is retracted and the element 72 moves into contact with a downstream compactor plate 73 on the element forming conveyor 72 . As the elements 72 move downstream, an upstream compactor plate 74 moves into contact with the smooth web face of the upstream most stream 63 in the formed element 70 . Because the downstream compactor plate 73 engages an unglued strip 65 and the upstream compactor plate 74 engages the smooth web face of the last strip which carries no glue, the problem of a strip adhering to the toothed gate 71 or one of the compactor plates 73 or 74 is minimized.
[0056] Instead of utilizing an unglued strip 65 , it is also possible to insert an unglued sheet of paper 84 which adheres to the glued flute tips of the facing strip and becomes part of the core element 70 . Alternately, the face of the downstream compactor plate 73 , in the previously described embodiment, may be coated with a non-stick material.
[0057] In an alternate method for compacting the formed core elements 70 , the element forming conveyor 72 may be angled downwardly to utilize the force of gravity to help press the strips 63 together. In addition, a weighted plate may be inserted against the smooth web face of the rearmost strip of the core element 70 .
[0058] In a presently preferred apparatus for forming flutes in a continuous web, reference is made to FIGS. 15-17 . The apparatus includes an upper rotary fluting roll 85 made of a rigid tubular cylindrical shell 86 . The fluted outer surface is defined by circumferentially spaced flute teeth 87 having adjacent tips 88 and gullets 90 . The teeth 87 are spaced at a common flute pitch which, for example, for a large fluting apparatus, may be ¾″ (about 19 mm). The flute tooth depth vertically from tip 88 to gullet 90 may be ½″ (about 13 mm). As indicated previously, the flutes are substantially larger than typically formed in the corrugating industry for the manufacture of corrugated paperboard and the like. The fluting roll 85 may have a nominal diameter of 16″ (about 406 mm).
[0059] A lower rotary counterroll 91 is mounted and positioned for counterrotational engagement with the fluting roll 85 . Typically, the upper fluting roll 85 is the driving roll and the counterroll 91 is the driven roll. The nominal diameter of the counterroll 91 may be 8″ (about 203 mm). The counterroll 91 also has a rigid cylindrical interior shell 92 , but it is covered on its exterior with an elastomer sleeve 93 , preferably made of a relatively hard rubber, such as conventional die rubber. Imbedded in the elastomer sleeve 93 are a plurality of circumferentially spaced fluting bars 94 having round outer tips 95 circumferentially spaced at the pitch of the fluting roll 85 . As may be seen in the drawings, the fluting bars 94 have a sort of tear drop cross sectional shape and are preferably made from hollow aluminum extrusions. The fluting bars 94 and the flute teeth 87 of the fluting roll 85 extend axially together and parallel to one another the full width of the rolls 85 and 91 , which conveniently may be 96″ (about 245 cm). However, axial roll length is not critical and the rolls may be made with any length suited to the web material on which they operate.
[0060] The flute teeth 87 of the fluting roll 85 are generally V-shaped in cross section with the gullets 90 having a circular cross section. The tips 88 also have a circular cross section. The flute teeth 87 have flat flanks 96 between the tips and gullets. It is significant in the formation of large pitch flutes in a web 97 , as shown in FIGS. 16 and 17 , that the fluting bars make contact with the formed web flutes 98 only in the gullets 90 of the fluting roll 85 . In addition, there is no contact between the fluting roll flute tips 88 and the flanks 100 of the counterroll fluting bars 94 . Thus, as may best be seen in FIG. 17 , the tips 95 of the fluting bars 94 progressively engage and push the web material 97 into the gullets 90 of the fluting roll 85 with operative contact between the fluting bar tips 95 and the teeth 87 of the fluting roll only at the points of full web flute formation.
[0061] Preferably, the tips 95 of the fluting bars 94 have a radius slightly less than the radius of the flute teeth gullets 90 of the fluting roll 85 . Typically, for a web 97 of a given thickness, radius of the fluting tips 95 is less than the radius of the flute teeth gullets 90 by an amount approximately equal to the web thickness, e.g. 0.009″ (0.23 mm). Instead of circular cross section tips 88 and 95 on the fluting roll teeth 85 and fluting bars 94 , respectively, a compound radius may be used.
[0062] The rubber sleeve 93 in which the fluting bars 94 are embedded serves two important functions, in addition to providing firm support for the bars. First, if the lower counterroll 91 were made with the fluting bars 94 rigidly attached to the steel shell 92 , the vertical radial distance between the two roll centers, as the paper web 97 passes through the fluting nip, is forced to change. Without the cushioning effect provided by the rubber sleeve 93 , the rigid steel rolls would be forced to deflect, resulting in high vibration and noise and, quite possibly, damage to the web. For example, using a 16− diameter fluting roll 85 and an 8″ diameter counterroll 91 , referring to FIGS. 16 and 17 , as the fluting bar 101 that is just upstream from the top dead center position of the rolls and has the web fully engaged with the gullet 90 , moves to the top dead center position (from FIG. 16 to FIG. 17 ), the gullet 90 and the bar tip 95 move relatively more closely together by 0.027″ (0.7 mm). However, the deflection that would otherwise have to be taken up by rigid steel rolls is absorbed by the rubber sleeve 93 , thereby minimizing vibration and noise, as well as possible damage to the web 97 .
[0063] In addition, after the fluting bar 94 passes the top dead center position (moving from FIG. 17 to FIG. 16 ), the resilience of the rubber sleeve 93 pushes the tip 95 of the fluting bar radially outwardly so that it maintains contact with the fluted web in the gullet 90 until the following fluting bar makes full contact in the tooth gullet 90 with which it is associated. This provides a smooth transition from flute bar to flute bar without loss of intimate fluting contact between the fluting bar tips 95 and the fluting roll gullets 90 .
[0064] To assist in formation of the flutes 98 , it is desirable to provide vacuum to the gullets 90 of the upper roll flute teeth 87 . Vacuum is supplied through a series of circumferentially spaced, axially extending vacuum bores 102 in the fluting roll shell 86 . With appropriate internal valving, the vacuum is preferably applied at the point of flute formation and to help retain the formed web in contact with the roll, as shown in FIGS. 16 and 17 . After the fluted web 103 moves out of the fluting nip between the rolls 85 and 91 , a glue roll 109 may be used to apply an adhesive to the web which is subsequently joined downstream to a liner web, as shown in FIGS. 20 and 21 .
[0065] It may also be desirable to heat the fluting roll 85 by supplying steam to a circumferentially spaced, axially extending series of steam bores 104 formed in the fluting roll shell 86 . As shown, the steam bores 104 alternate circumferentially with the vacuum bores 102 . However, any convenient arrangement may be used. The heat applied to the roll 85 and the web 97 helps precondition the fluted web for downstream application of an adhesive, such as a starch-based glue, to the flute tips of the fluted web 103 , as will be described in more detail below. The heat also enhances the progress of the starch-based glue into the green bond stage, as is known in the art.
[0066] Because in some applications it may be desirable to waterproof a paper web 97 , the heated fluting roll 85 may assist in drying a liquid adhesive applied to the web 97 before fluting. For example, if an A-phase phenolic resin is applied to the paper web, it is dried to a B-phase before fluting.
[0067] In accordance with the overall system of the present invention for producing open core elements, fluted webs are joined with an adhesive to plain unfluted webs in various steps of the operation to progressively form the open core elements as shown schematically in FIGS. 12-14 . In the system previously described, for example, glue rolls 23 ( FIG. 1 ), 80 ( FIG. 7 ), 30 ( FIG. 3 ), 64 ( FIG. 8) and 109 ( FIGS. 15 and 20 ) are used to apply a liquid adhesive to the flute tips of a fluted web. FIGS. 18 and 19 show a glue machine which may include any of the glue rolls just identified.
[0068] In FIG. 18 , a glue machine 105 includes a pump 106 for supplying a liquid adhesive, such as an aqueous starch-based adhesive, and a glue roll assembly 107 for applying the adhesive to the flute tips of an incoming web 108 .
[0069] A presently preferred pump 106 comprises a ganged array of positive displacement pumps commonly driven to provide laterally spaced beads of adhesive to the glue roll 110 of the glue roll assembly 107 . Preferably, the pump 106 comprises a ganged peristaltic pump which receives a supply of a liquid adhesive to the inlet ends 111 of laterally spaced flexible tubes 112 made of a suitable synthetic rubber, such as neoprene. The tubes extend through the pump 106 and terminate in outlet ends 113 evenly spaced laterally across the surface of the glue roll 110 . The pump 106 may, for example, have 24 supply tubes 112 and, if the adhesive is being applied to a 48″ web, the tubes 112 would be spaced at about 2″ intervals.
[0070] The pump 106 includes a supporting frame 114 that has a semicylindrical backing surface 15 and a driven rotating roller assembly 116 that has an axis of rotation coincident with the axis of the backing surface 115 . In the embodiment shown, there are four laterally spaced roller assemblies, each of which carries three orbitally mounted rollers 117 . The adhesive supply tubes 112 extend from an upstream tube harness 118 downwardly between the backing surface 15 and the roller assembly 116 to the outlet ends 113 of the tubes adjacent the surface of the glue roll 110 . Rotation of the orbital rollers 117 brings individual rollers sequentially into contact with the tubes 112 , squeezing them against the backing surface 115 and pushing accurately metered amounts of liquid adhesive through the tubes to the outlet ends 113 . By carefully controlling the supply of liquid adhesive to the inlet ends 111 of the tubes 112 , the pre-calculated exact volume of adhesive desired to be applied to the web is delivered by the pump to the glue roll. In this manner, the pump supplies only the volume of adhesive needed and there is no need to recirculate unused adhesive which could be contaminated or otherwise unsatisfactory for reuse. Once the starch formula has been used to calculate the mix of starch and water (with other well known additives), the volume to be supplied to the pump and the transferred to the glue roll is calculated based on pump rotational speed, web speed and web width. One important benefit of utilizing a peristaltic pump apparatus is that none of the pump mechanism, except the tubes 112 , is contacted by the adhesive. This minimizes adhesive build up on internal parts and facilitates considerably the cleaning of the glue machine, as will be described.
[0071] The outlet ends 113 of the adhesive supply tubes 112 are attached to a tube outlet support assembly 120 extending across the width of the glue machine 105 above the glue roll 110 . The glue roll assembly 107 includes a flexible adhesive spreading tongue 121 that has its upper edge attached to a tongue support 122 and a free downstream end 123 that is shaped to lie against and conform to the cylindrical surface of the glue applicator roll 110 . The beads of liquid adhesive supplied to the glue roll surface upstream of the shaped end 123 of the spreading tongue 121 are smoothed into a uniform layer on an engraved surface on the glue roll 110 from which it is applied to the flute tips of the incoming web 108 that makes tangent contact with the glue roll 110 .
[0072] The outlet ends 113 of the adhesive supply tubes 112 are mounted on the support assembly 120 such that their positions can be selectively adjusted to a desired spacing in order to accommodate different width webs 108 . In the embodiment shown in FIG. 19 , each tube end 113 is carried on a separate tube holder 124 and all of the tube holder are mounted on an elastic band 125 that is partially stretched to provide an initial closely spaced array. By stretching the band equally and in opposite directions, as with a lead screw arrangement 126 , the tube holders 124 and attached tube ends 113 may be moved to an increased spacing.
[0073] The glue machine 105 also includes a laterally adjustable adhesive width control assembly 127 that includes a pair of laterally adjustable doctor blades 128 which may be moved into contact with the glue roll surface to remove unneeded adhesive and to define the width of the glue layer to be applied to the incoming web 108 . The doctor blades 128 are slidably mounted on a lateral support member 130 and each doctor blade assembly includes a vacuum connection 131 to carry unused glue away. When the glue supply from the pump 106 is terminated, the inlet ends 111 of the glue supply tubes 112 are supplied with a cleaning fluid that travels through the tubes, onto the glue roll and mating face of the spreading tongue 121 and over the cleaning doctor blade 133 .
[0074] It is also preferable to mount the adhesive supply tubes 112 so they can be adjusted axially in the tube harness to change their positions to present different areas to contact by the pump rollers 117 . In this manner, the points at which constant intermittent squeezing of the tubes occurs can be changed to present fresh unstressed tube portions to the rollers.
[0075] In FIG. 20 , there is shown the use of the large flute forming apparatus of FIG. 15 to make a single face fluted web 134 . The fluted web 103 is retained on the fluting roll 85 where a liquid adhesive is applied by a glue roll 109 to the flute tips of the web 103 . Further downstream, a web delivery or generator roll 135 brings a liner web 136 into contact with the glued flute tips of the fluted web 103 .
[0076] In FIG. 21 , there is shown an adaptation of the large flute forming apparatus of FIG. 15 for forming a composite double medium, single liner fluted web 140 . The apparatus includes a pair of fluted rolls 85 and 85 ′ that are mounted for counter rotation in closely spaced relation and with their teeth in register to form a nip 137 . A counterroll 91 , 91 ′ is positioned diametrically opposite the nip 137 and in counter rotating engagement with the respective fluted roll 85 , 85 ′.
[0077] Each of the incoming medium webs 97 and 97 ′ is provided with the large flutes, as previously described, and exits the fluting nip in contact with the fluted roll 85 and 85 ′. An adhesive is applied to the flute tips of the respective fluted webs 103 and 103 ′ by glue rolls 109 and 109 ′, respectively. A web delivery roll 135 brings a liner web 136 into intimate contact with the glued flute tips of lower fluted web 103 . The resulting single face web 138 enters the nip 137 where it is joined with the glued flute tips of fluted web 103 ′ to form the composite double medium, single liner fluted web 140 . It may be advantageous to retain the composite web 140 on one or the other of the fluted rolls 85 and 85 ′ to take advantage of the heat to enhance the attainment of green bond strength for further processing.
[0078] Downstream of the nip 137 , the web 140 may be slit longitudinally on slit lines 141 (see FIG. 22 ) into a plurality of narrow strips 142 which may be, for example, ⅜″ wide. The large flutes themselves, as previously described, may have a flute pitch of ¾″ and a flute depth of ½″. The narrow strips 142 are then die cut in the lateral or cross machine direction at the base of the gullet 143 . The lateral die cuts 149 are made along the center of the glue line 144 so that the resulting small pieces 146 remain glued. In other words, where the gullets of the fluted webs 103 are joined to opposite sides of the liner web 136 , each adjacent laterally cut web piece will share one-half of the glue line 144 . If the lateral die cut slits 145 are made every other pitch length, as shown in FIG. 22 , the resultant small web pieces 146 will have a sort of FIG. 8 shape which shape is stabilized and fairly rigid by the intermediate glued liner web 136 .
[0079] The small web pieces 146 may be used as a substitute for the ubiquitous styrofoam packaging and filter “peanuts” that are fraught with environmental and disposal problems. Small web pieces 146 have a very low material weight-to-volume ratio, possess the necessary rigidity, and are recyclable or at least biodegradable. Furthermore, the process and apparatus of the present invention can use medium web stock 108 and liner web stock 136 that, in the corrugating industry, are referred to as “trim rolls”. These are rolls of edge trim paper resulting from trimming a standard width (e.g. 96″) roll of paper. Trim rolls of about 1 foot in axial length or less are typically discarded or repulped. Even trim rolls as long as 4 feet are difficult to dispose of. However, trim rolls of this range in axial lengths are well suited for the process of the present invention.
[0080] In FIG. 23 there is shown a modified apparatus for making open core elements in accordance with the present invention. A single face web 147 is formed in a single facer 148 by joining a liner web 150 from roll 151 to a corrugated medium web 152 from a roll 153 in a known manner. The single face web 147 exiting the single facer may be heated to enhance curing by moving over a heating plate 154 after which the web is slit longitudinally in a slitting knife 155 into a plurality of adjacent single face web strips 156 . A glue roll 157 applies a suitable adhesive (e.g. starch) to the exposed flute tips of the medium web 152 . The glued strips 156 are then separated and wound with the liner web 150 on the outside to form circular spiral open core elements 158 . The elements may be wound to any desired diameter with the strips 156 cut in a cutoff knife 160 to establish the desired diameters. Other control of the slitting knife 155 and cutoff knife 160 may be employed to provide core elements 158 of different thicknesses and/or diameters.
[0081] Whereas the open core elements 13 and 70 of the previously described embodiments are rectangular in shape and typically enclosed on both faces with rectangular skin sheets, circular core members 158 made in accordance with the FIG. 23 embodiment may also be used to form rectangular panels utilizing rectangular skin sheets. As shown, for example, in FIG. 24 , a rectangular panel having opposite skin sheets 161 of say 12′×24′ can utilize large 12′ diameter core elements 162 with the peripheral spaces filled by say 2′-3′ diameter small core elements 163 . It is believed that spirally formed core elements 158 possess better strength in certain applications. Also, the simplified process and apparatus of FIG. 23 provides material handling advantages over the rectilinear processes of the previously described embodiments. A further and most important advantage in the manufacture of spirally wound circular open core elements is that very narrow strips 156 , as thin as, for example, ½″ may be processed. An attempt to handle such thin strips using the cross-transfer mechanism and methods of the previously described embodiments would likely not be successful.
[0082] Referring now to FIG. 25 , there is shown an improved apparatus for the lay-up of hollow core elements, particularly suitable for the manufacture of hollow core elements having a depth or thickness suitable for the manufacture of floor and roof panels for building construction. As shown in my co-pending patent application Ser. No. 11/485,823, a 16 in. panel thickness for roof construction is typically suitable.
[0083] In the system of FIGS. 25-27 , a composite double wall open face web 25 is formed to a width of 48 in., as described above with respect to the FIG. 1 system. The web 25 is then slit longitudinally in a slitter 164 to form three 16 in. wide open face double wall strips 165 . In a manner similar to that previously described, the strips 165 are oriented with the flutes on top and extending laterally. The strips are directed beneath a second glue roll 30 which applies a suitable adhesive to the exposed flute tips of the strips 165 . When the group of three strips 165 reaches a selected length in the machine direction (e.g. 50 ft. for a roof panel), a cutoff knife cuts the strips to length. The three glued and cut strips 165 are accelerated on a transport conveyor 166 to form a gap between the strips and the next-following uncut strips. The strips are then transferred laterally on a cross transfer conveyor 170 onto an accumulation conveyor 167 using a cross transfer pusher 168 . From the accumulation conveyor, a speed-up conveyor 169 accelerates the lead strip 165 and creates a gap between it and the next adjacent strip. The speed-up conveyor 169 delivers the strips individually onto a higher speed stacker infeed conveyor 178 that engages the upstream (rear) edge of the strip and launches the strip into the bay of a downstacker 171 . The transfer of individual strips 165 into the downstacker 171 may be conveniently effected by engaging the upstream edge of the strip on the stacker infeed conveyor 178 with positive engagement dogs, or the like, using a servo drive for rapid acceleration.
[0084] In the stacker 171 , the strips 165 are initially supported along both long edges with, for example, rotatable fingers positioned in spaced orientation along the strip edges. Both edges are released simultaneously and the strip drops vertically onto a supporting pan 179 out of the path of the next incoming strip. The strips 165 are preferably guided in their vertical descent on the pan 179 by engaging opposite narrow edges to assure that the strips are accurately aligned with one another in the stacker. Vertically moving arrays of guide belts 172 spaced along the strip edges are a presently preferred arrangement. The belts 172 are adjustable to vary the space between them for handling different width strips.
[0085] Because the strips 165 have fresh adhesive glue on the flute tips, the second incoming strip 165 will drop onto the first strip in the stacker where the smooth web underside of the second strip will engage and adhere to the glued flute tips of the first strip. The third strip will follow in the same manner and the result will be the formation in the stacker of a three-ply stack of open face double wall strips comprising an intermediate open core block 173 .
[0086] Each three-ply intermediate open core block 173 is removed from the stacker 171 by lifting the pan 179 to the top of the stacker bay, and rotating the stacker 171 90° in the counterclockwise direction to upend the open core block 173 (from the FIG. 26 to the FIG. 27 position). Thereafter, it is moved horizontally into face-to-face relation with the block that precedes it. Glued flutes of each block, facing in the downstream direction, contact the smooth web face of the preceding block and, when deposited on an element forming conveyor 176 , the blocks 173 are brought into adhesive contact. It may be desirable to apply vacuum to the block supporting pan 179 in the vertical upended position to hold the block until it is brought into contact with the preceding block.
[0087] The large building stack 174 moves against a stacking pan 175 on a core panel building conveyor 176 . Because the lead face of the first block 173 has fresh adhesive applied upstream to the exposed flute tips, a face sheet must be inserted against the glued flute tips somewhere upstream of the FIG. 25 system. This avoids contact between the glued flute tips and the stacking pan 175 . As shown in FIG. 14 , each intermediate open core block 173 will thus comprise a three-ply stack of open face double wall strips 60 (including an end element facing sheet 84 ).
[0088] If a large open core panel is formed, such as might be used as a building floor or roof panel, each intermediate open core block 173 may have a thickness of 3 in., a width in vertical direction of 16 in. and a length, in the cross machine direction, of 50 ft. To form an open core roof or floor element having a width of 10 ft., 40 intermediate blocks 173 would be assembled on the core panel building conveyor 176 . For this large an open core panel, strips 165 having a length of 50 ft. would be produced. However, the inherent stiffness of a three-ply double wall intermediate open core block 173 makes these intermediate blocks much easier to handle. After the formation of a large 50 ft.×10 ft.×16 in. deep roof or floor panel, the panel is moved out of the apparatus on a suitable panel discharge conveyor. Subsequently, a floor or roof panel is completed by affixing upper and lower skin sheets to the open core panel 174 in accordance with the teachings in my co-pending application Ser. No. 11/485,823, filed Jul. 13, 2006, and Ser. No. 11/777,002, filed Jul. 12, 2007.
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A continuous, fully automated and highly productive system for the production of open core elements utilizes a fluting method and related apparatus effective for providing large pitch flutes for the input webs used in forming the core elements. A wide variety of core elements can be produced for uses ranging from large light weight building panels to small light weight packing elements.
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BACKGROUND OF THE INVENTION
[0001] The invention relates generally to an electrohydraulic clutch and more specifically to an electrohydraulic clutch having an electric motor, a hydraulic fluid circuit and a multiple plate friction clutch pack.
[0002] Clutches which are activated or energized by electromagnetic coils are extraordinarily common components in rotary power transmission systems, both in stationary applications and in motor vehicles. Such electromagnetic clutches may be broadly characterized by whether they provide on-off energy transfer or modulating energy transfer. In the case of the former, dog clutches which may include auxiliary synchronizing devices are utilized whereas in the latter, friction clutch packs having a plurality of interleaved friction plates or discs are utilized. In either case, an electromagnetic operator which translates or compresses components of the clutch upon energization activates the clutch and upon deenergization deactivates or relaxes the clutch.
[0003] One of the design and operational characteristics of electromagnetic clutches which receives significant engineering attention is power consumption. It is desirable, especially in motor vehicles, to design and utilize a clutch having low power consumption. Low power consumption is desirable in and of itself but it also reduces the heat generated by the coil and thus lower power consumption can reduce the need for cooling the coil, can improve the service life of the coil and is therefore overall a desirable design goal.
[0004] Another design consideration may be broadly characterized as control. It is desirable for motor vehicle drive line clutches to both engage smoothly and preferably imperceptibly and also modulate accurately in proportion to the control signal, that is, exhibit close correspondence between the magnitude of the electrical drive signal (representing the desired proportion of clutch engagement) and the actual clutch engagement.
[0005] The present invention is directed to these design goals.
SUMMARY OF THE INVENTION
[0006] An electrohydraulic clutch includes a bi-directionally rotatable electric motor, a hydraulic circuit and a multiple plate friction clutch pack. The electric motor drives a ball screw through a multiple gear speed reduction assembly. The ball screw output translates a master piston of the hydraulic circuit which in turn advances and retracts an annular slave piston disposed adjacent the friction clutch pack. Hence, actuation of the electric motor displaces hydraulic fluid and compresses or relaxes the friction clutch pack. An anti-back drive assembly disposed between the motor and gear reduction assembly includes a wrap spring disposed between two hubs and contained within a cylindrical aperture or housing.
[0007] It is thus an object of the present invention to provide an electrohydraulically actuated friction clutch.
[0008] It is a further object of the present invention to provide an electrohydraulic clutch including a multiple plate friction clutch assembly.
[0009] It is a still further object of the present invention to provide an electrohydraulic clutch having an electric motor and anti-back drive assembly.
[0010] It is a still further object of the present invention to provide an electrohydraulic clutch for use in transfer cases, rear axles and other motor vehicle drive line components.
[0011] Further objects and advantages of the present invention will become apparent by reference to the following description of the preferred embodiment and appended drawings wherein like reference numbers refer to the same component, element or feature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a diagrammatic view of a four-wheel drive motor vehicle power train having an electrohydraulic clutch assembly according to the present invention utilized in conjunction with a rear differential;
[0013] FIG. 2 is a full, sectional view of an electrohydraulic clutch assembly according to the present invention taken along line 2 - 2 of FIG. 1 ; and
[0014] FIG. 3 is a full, sectional view of an electrohydraulic clutch assembly according to the present invention taken along line 3 - 3 of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Referring now to FIG. 1 , a four-wheel vehicle drive train incorporating the present invention is diagrammatically illustrated and designated by the reference number 10 . The four-wheel vehicle drive train 10 includes a prime mover 12 such as an internal combustion gas or Diesel engine or hybrid power plant which is coupled to and directly drives a transaxle 14 . The output of the transaxle 14 drives a bevel or spiral bevel gear set 16 which provides motive power to a primary or front drive line 20 comprising a front or primary propshaft 22 , a front or primary differential assembly 24 , a pair of live front axles 26 and a respective pair of front or primary tire and wheel assemblies 28 . It should be appreciated that the front or primary differential 24 is conventional.
[0016] The bevel or spiral bevel gear set 16 also provides motive power to a secondary or rear drive line 30 comprising a secondary propshaft 32 having appropriate universal joints 34 , a rear or secondary differential assembly 36 , a pair of live secondary or rear axles 38 and a respective pair of secondary or rear tire and wheel assemblies 40 .
[0017] The foregoing description relates to a vehicle wherein the primary drive line 20 is disposed at the front of the vehicle and, correspondingly, the secondary drive line 30 is disposed at the rear of the vehicle, such a vehicle commonly being referred to as a front wheel drive vehicle or adaptive front wheel drive vehicle. The designations “primary” and “secondary” utilized herein refer to drive lines providing drive torque at all times and drive lines providing supplemental or intermittent torque, respectively. These designations (primary and secondary) are utilized herein rather than front and rear inasmuch as the invention herein disclosed and claimed may be readily utilized with vehicles wherein the primary drive line 20 is disposed at the rear of the vehicle and the secondary drive line 30 and components within the secondary differential assembly 36 are disposed at the front of the vehicle.
[0018] Thus, the illustration of FIG. 1 , wherein the primary drive line 20 is disposed at the front of the vehicle should be understood to be illustrative rather than limiting and that the components and the general arrangement of components illustrated is equally suitable and usable with a primary rear wheel drive vehicle.
[0019] Associated with the vehicle drive train 10 is a controller or microprocessor 50 which receives signals from a plurality of sensors and provides a control, i.e., actuation, signal to an electrohydraulic clutch assembly 70 operably disposed before the secondary differential assembly 36 . Specifically, a first sensor such as a Hall effect or variable reluctance sensor 52 senses the rotational speed of the left primary (front) tire and wheel assembly 28 and provides an appropriate signal to the microprocessor 50 . Similarly, a second variable Hall effect or variable sensor 54 senses the rotational speed of the right primary (front) tire and wheel assembly 28 and provides a signal to the microprocessor 50 . A third Hall effect or variable reluctance sensor 56 senses the rotational speed of the left secondary (rear) tire and wheel assembly 40 and provides a signal to the microprocessor 50 . Finally, a fourth Hall effect or variable reluctance sensor 58 associated with the right secondary (rear) tire and wheel assembly 40 senses its speed and provides a signal to the microprocessor 50 . It should be understood that the speed sensors 52 , 54 , 56 and 58 may be independent, i.e., dedicated, sensors or may be those sensors mounted in the vehicle for anti-lock brake systems (ABS) or other traction control or stability systems. It should also be understood that an appropriate and conventional counting or tone wheel is associated with each of the speed sensors 52 , 54 , 56 and 58 although they are not illustrated in FIG. 1 .
[0020] The controller or microprocessor 50 may also receive information from other sensors regarding vehicle operating variables and conditions. For example, an engine speed sensor 62 may be utilized to provide a real time signal to the microprocessor 50 regarding the speed of the engine 12 . Additionally, a throttle position sensor 64 may be included to provide a real time signal to the microprocessor 50 regarding the degree or extent of activation of the accelerator pedal. Furthermore, a steering angle sensor 66 may be utilized to provide real time data to the microprocessor 50 regarding the angular position of the steering column, the lateral position of the steering rack or the angular position of the front tire and wheel assemblies 28 . The controller or microprocessor 50 includes software which receives and conditions the signals from the sensors 52 , 54 , 56 and 58 as well as the optional sensors 62 , 64 and 66 , determines corrective action to improve the stability of the vehicle, maintain control of the vehicle and/or correct or compensate for a skid or other anomalous operating condition and provides an output signal to the electrohydraulic clutch assembly 70 .
[0021] Referring now to FIG. 2 , the electrohydraulic clutch assembly 70 includes a preferably metal housing 72 having various bores, ports, slots, faces, passageways and the like which receive the various components thereof. A first end plate 74 is especially formed to receive various shafts, fits tightly on one end face of the housing 72 and is secured thereby a plurality of fasteners (not illustrated). A second end plate 76 is secured to the other end face of the housing 72 by a plurality of fasteners 78 . Disposed within a suitably sized region of the housing 72 is a bi-directional, fractional horsepower electric motor 80 . The electric motor 80 includes an output shaft 82 which is supported upon suitable bearings 84 and includes a drive hub 86 having a diametric vane. A driven pinion gear 88 which is freely rotatably disposed on the output shaft 82 includes two-axially extending lugs 90 . The lugs 90 engage opposite sides or faces of the vaned drive hub 86 thus allowing limited (approximately 1500 to 1600) angular relative rotation between the vaned drive hub 86 and the pinion gear 88 . A wrap spring 92 is wrapped about and extends between the vaned drive hub 86 and the lugs 90 and the pinion gear 88 .
[0022] The wrap spring 92 is received within a relatively closely fitting cylindrical aperture or passageway 94 which may be formed in the housing 72 or may be a bore or passageway in a stationary collar or similar component. The wrap spring 92 , the associated drive hub 86 and the pinion gear 88 cooperate to accommodate bi-directional drive of the pinion gear 88 by the motor 80 as the lugs 90 engage and thus achieve direct drive of the pinion gear 88 by the vaned drive hub 86 . However, when electrical power to the electric motor 80 is terminated, and forces attempt to back drive the electric motor 80 , the wrap spring 92 is unwound by rotation of the pinion gear 88 . As the wrap spring 92 is unwound and expands, it engages the surface or wall of the aperture or passageway 94 thus inhibiting further reverse rotation of the pinion gear 88 .
[0023] The pinion gear 88 is in constant mesh with a first spur gear 96 . The first spur gear 96 is supported upon a first shaft 98 and is coupled to or integrally formed with a smaller diameter second pinion gear 100 which is in constant mesh with a second spur gear 102 . The second spur gear 102 is likewise rotatably supported upon a second stub shaft 104 . The second spur gear 102 is coupled to or preferably integrally formed with a third pinion gear 106 . The third pinion gear 106 is in constant mesh with and drives a third spur gear 108 which is secured to a drive shaft 110 .
[0024] The drive shaft 110 is preferably supported by a pair of anti-friction bearings such as roller bearing assemblies 112 . The drive shaft 110 includes a ball screw portion 114 . Between the drive shaft 110 and the ball screw portion 114 are mounted a plurality of Belleville springs or washers 116 that function as a resilient stop. Disposed about the ball screw portion 114 is a recirculating ball nut 122 . The recirculating ball nut 122 includes a plurality of balls or roller bearings 124 which recirculate about the complementarily configured grooves in the ball screw 114 and thus provide a low friction interconnection between the ball screw 114 and the nut 122 . As the shaft 110 bi-directionally rotates in response to bi-directional rotation of the output shaft 84 of the electric motor 80 , the recirculating ball nut 122 translates to the left and right. The ball screw 114 and the recirculating ball nut 122 thus function as a rotary to linear motion transducer.
[0025] The recirculating ball nut 122 is coupled to a master piston 130 which translates axially within an elongate cylinder 132 which also contains the lead screw portion 114 . The master piston 130 includes a pair of O-ring seals 134 which are received within suitably configured circumferential grooves 136 near each end of the piston 130 . The master piston 130 is shown in FIG. 2 in its fully advanced or extended position. As the master piston 130 is retracted by rotation of the ball screw 114 , it passes a port 138 which communicates with a fluid reservoir 140 . The fluid reservoir 140 is preferably maintained substantially full of a hydraulic fluid 142 such that the cylinder 132 may be fully filled with hydraulic fluid when the piston 130 is retracted. A flexible seal 144 accommodates changes in volume of the hydraulic fluid 142 and a metal plate or cap 146 secures the flexible seal 144 and maintains a fluid tight seal thereabout. The cylinder 130 narrows to a first fluid passageway 150 which provides for communication and flow of the hydraulic fluid 142 to the driven components of the electrohydraulic clutch assembly 70 .
[0026] Turning now to FIG. 3 , the electrohydraulic clutch assembly 70 includes an input shaft 170 preferably including a set of external or male splines or gear teeth 172 and a smaller diameter threaded region 174 . The male or external splines or gear teeth 172 are engaged by complementarily configured female splines or gear teeth 176 formed on the interior of a cylindrical region 178 of a flange 180 . The flange 180 preferably includes a plurality of through apertures 182 which may receive threaded fasteners or other components (not illustrated) associated with a drive component to the electrohydraulic clutch assembly 70 such as a universal joint 34 , illustrated in FIG. 1 . A retaining nut 184 as well as one or more flat washers 186 may be utilized to positively retain the flange 180 upon the input shaft 170 . A tapered roller bearing assembly 188 rotatably supports the input shaft 170 within the housing 72 of the electrohydraulic clutch assembly 70 .
[0027] The electrohydraulic clutch assembly 70 also includes a multiple plate friction clutch pack assembly 190 . Driving the friction clutch pack assembly 190 are a plurality of male or external splines or teeth 192 disposed on the input shaft 170 which engage complementarily configured female spines 194 on a first plurality of smaller diameter friction clutch plates or discs 196 . The first plurality of friction clutch plates or discs 196 are interleaved with a second plurality of larger diameter friction clutch plates or discs 198 . The friction clutch plates or discs 196 and 198 include suitable clutch paper or friction material in accordance with conventional practice. Each of the second plurality of larger diameter friction clutch plates or discs 198 includes male or external splines 202 which engage and drive complementarily configured female or internal splines 204 formed on the interior of a cylindrical portion 206 of an output shaft 210 . The output shaft 210 is rotationally isolated from and stabilized within a portion of the input shaft 170 by a roller bearing assembly 212 . A thrust bearing assembly 214 is also disposed between the input shaft 170 and the output shaft 210 which is further supported by a tapered roller bearing assembly 216 . Suitable oil seals 218 prevent the ingress of foreign matter and maintain a fluid tight seal between the housing 72 , the input shaft 170 and the output shaft 210 .
[0028] The output shaft 210 preferably includes internal or female splines or gear teeth 222 which are complementary to and engage suitably configured male splines or gear teeth (not illustrated) disposed within the rear differential assembly 36 which receive torque from the electrohydraulic clutch assembly 70 .
[0029] The first fluid passageway 150 illustrated in FIG. 2 communicates with a cylinder 228 which receives an annular slave piston 230 . A first outer O-ring 232 and a second inner O-ring 234 disposed within suitable circular grooves provide a fluid tight seal against the side walls of the annular slave piston 230 . A register pin 238 seats within a complementarily configured blind aperture 242 in the annular slave piston 230 and inhibits rotation of the annular piston 230 within the cylinder 228 . The annular piston 230 engages a thrust bearing 244 which permits relative rotation between the annular piston 230 and a circular apply plate 246 . The circular apply plate 246 transfers axial motion and force generated by the piston 230 to the friction clutch pack assembly 190 . The apply plate 246 includes female or internal splines 248 which are complementary to and engage the male splines 192 on the input shaft 170 . Thus, the apply plate 246 rotates with the input shaft 170 .
[0030] A second fluid passageway 252 provides communication between the cylinder 228 and a fluid pressure sensor or transducer 254 . The pressure fluid sensor or transducer 254 is preferably a piezoelectric device which provides a signal in a single or multiple conductor cable 256 to the microprocessor 50 regarding the real time hydraulic fluid pressure within the cylinder 228 . Electrical energy is provided to the electric motor 80 through a single or multiple conductor cable 258 illustrated in FIGS. 1 and 2 .
[0031] The operation of the electrohydraulic clutch assembly 70 will now be described with reference to all the drawing figures. As noted, signals are preferably provided by the wheel speed sensors, 52 , 54 , 56 and 58 and the other sensors 62 , 64 and 66 to the microprocessor 50 . The microprocessor 50 provides a signal in the cable 258 to the electric motor 80 commanding it to rotate in one of two directions to increase or decrease the pressure of the hydraulic fluid 142 and thus the torque transferred through the friction clutch pack assembly 190 . If the command from the microprocessor 50 is to increase torque throughput, the electric motor 80 rotates in a direction to advance the recirculating ball nut 122 and advance the master piston 130 within the elongate cylinder 132 . As the master piston 130 translates, hydraulic fluid 142 is transferred, its pressure increases and the annular slave piston 230 translates, compressing the friction clutch pack assembly 190 . A command from the microprocessor 50 to reduce torque transferred through the friction clutch pack assembly 190 results in the opposite action.
[0032] As noted above, the wrap spring 92 inhibits back driving of the electric motor 80 by the hydraulic pressure exerted on the piston 130 and the lead screw portion 114 . This is achieved, as also noted above, by the expansion of the wrap spring 92 and grounding or contact with the surface of the cylindrical aperture or passageway 94 as it is driven in a direction which both unwinds it and corresponds to retraction of the piston 130 . The prevention of back driving and thus the maintenance of a given pressure of the hydraulic fluid 142 and corresponding torque delivery through the friction clutch pack assembly 190 allows the electric motor 80 to be de-energized after it has achieved a desired position and fluid pressure thereby conserving electrical power. In this regard, it should also be noted that the pressure transducer 254 provides information to the microprocessor 50 regarding the current, actual pressure of the hydraulic fluid 142 which corresponds to a level of torque throughput. Such information may be utilized by the microprocessor 50 to adjust, in real time, the electrical energy delivered to the electric motor 80 to achieve a desired torque throughput.
[0033] Finally, it should be noted that the design of the housing 72 as well as the arrangement of components provides a passive oiling or lubrication system to the various components within the electrohydraulic clutch assembly 70 . Thus, not only is the need for specific lubricating means such as a pump avoided but the assembly exhibits improved durability and service life.
[0034] The foregoing disclosure is the best mode devised by the inventors for practicing this invention. It is apparent however, that devices incorporating modifications and variations will be obvious to one skilled in the art of electrohydraulic clutch assemblies. Inasmuch as the foregoing disclosure presents the best mode contemplated by the inventors for carrying out the invention and is intended to enable any person skilled in the pertinent art to practice this invention, it should not be construed to be limited thereby but should be construed to include such aforementioned obvious variations and be limited only by the spirit and scope of the following claims.
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An electrohydraulic clutch includes a bi-directional electric motor, a hydraulic circuit and a multiple plate friction clutch pack. The bi-directional electric motor drives a ball screw through a gear reduction assembly. The ball screw output translates a master piston of the hydraulic circuit which in turn advances and retracts an annular sleeve piston disposed adjacent the friction clutch pack. Hence, actuation of the electric motor displaces hydraulic fluid and compresses or relaxes the friction clutch pack, thereby transferring or inhibiting torque.
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[0001] This application claims priority to German Patent Application No. 10 2006 018 124.7 filed Apr. 19, 2006, which is incorporated in its entirety herein by reference. This application is a continuation of U.S. application Ser. No. 11/737,397 filed Apr. 19, 2007, which is incorporated in its entirety herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The invention relates to a rotary pump having an adjustable, preferably variable, delivery volume, and a method for manufacturing it. The rotary pump can in particular be used as a lube oil pump for supplying lube oil to an internal combustion engine, in particular an internal combustion engine of a motor vehicle engine.
[0004] 2. Description of the Related Art
[0005] Lube oil pumps in motor vehicles are driven in accordance with the rotational speed of the engine which is to be supplied with the lube oil, usually directly or via a mechanical gearing of the engine. The rotational speed of the pump correspondingly increases with the rotational speed of the engine. Since rotary pumps have a constant specific delivery volume, i.e. they deliver substantially the same amount of fluid per revolution at any rotational speed, the delivery volume increases in proportion to the rotational speed of the pump. The engine's requirement also increases roughly in proportion to the rotational speed of the engine, up to a certain limiting rotational speed, beyond which however it deviates or at least levels out, such that when the limiting rotational speed is exceeded, the rotary pump delivers beyond the requirement. Adjustable rotary pumps have been developed in order to not have to direct the excess delivered amount into a reservoir, which incurs losses. Examples of adjustable rotary pumps include the internal-axle and external-axle toothed wheel pumps known from DE 102 22 131 B4. Adjustable vane pumps are also known. These pumps each comprise an actuating member which can be moved back and forth. In the examples cited, the delivery rotor is either a toothed wheel or a vane. In the known internal-axle toothed wheel pumps and vane pumps, the movement of the adjusting member adjusts the eccentricity between two mutually mating toothed wheels or the eccentricity between the vane and the actuating member in accordance with the requirement of the consumer. In external-axle toothed wheel pumps, the axial engagement length of two toothed wheels is adjusted. For adjusting, the respective actuating member is charged with an actuating force, for example charged directly with the high-pressure fluid.
[0006] The actuating force is counteracted by a spring member. In pumps of the type cited, which are increasingly manufactured from light metal alloys, in particular aluminum alloys, the surfaces of the pump casing and of the actuating member which are in frictional contact are surprisingly subject to particular wear and determine the service life of the pump.
SUMMARY OF THE INVENTION
[0007] An exemplary embodiment of the invention is based on a displacement-type rotary pump which comprises a casing including a delivery chamber, a delivery rotor which can be rotated in the delivery chamber about a rotational axis, and at least one actuating member which can be moved back and forth in the casing. The actuating member can surround the delivery rotor or preferably can be arranged on, i.e. facing, a front face of the delivery rotor. An actuating member which surrounds the delivery rotor can in particular be provided in internal-axle pumps, for example toothed ring pumps and vane pumps, and can be formed as a rotationally mounted eccentric ring such as is known from DE 102 22 131 B4 or EP 0 846 861 B1, or as a lifting ring. Preferably, however, an actuating member such as is known from external toothed wheel pumps, for example from DE 102 22 131 B4, is arranged on or facing a front face of the delivery rotor and axially seals the delivery chamber on the relevant front face. Such an actuating member forms an actuating piston which can be axially moved back and forth along the rotational axis of the feed wheel. An actuating member which surrounds the delivery rotor is rotationally or pivotably mounted, or alternatively can also be mounted such that it can be moved linearly. The delivery chamber comprises a low-pressure side and a high-pressure side. At least one inlet is arranged on the low-pressure side, and at least one outlet for a fluid to be delivered is arranged on the high-pressure side. The low-pressure side of the delivery chamber and the entire upstream portion of the system in which the pump is installed form the low-pressure side of the pump. The high-pressure side of the delivery chamber and the entire subsequent downstream portion of the system form the high-pressure side of the pump. The low-pressure side extends as far as a reservoir for the fluid, and the high-pressure side extends at least as far as the most downstream point of consumption requiring a high fluid pressure.
[0008] The actuating member can be charged with an actuating force in the direction of its mobility, said force being dependent on the pressure of the fluid on the high-pressure side of the pump or on another variable of the system which is decisive for the requirement. The pressure can be taken directly at the outlet of the delivery chamber or at a downstream pump outlet or can be taken from a point further downstream in the system, for example from the final point of consumption. Instead of or in addition to the pressure, the temperature of the fluid or of a component in the system in which the pump is installed, for example a temperature of the engine, can for example feature in forming the actuating force. Other physical variables for determining the actuating force are adduced as applicable. The actuating force can be generated by means of an additional actuating member, for example an electric motor. More preferably, however, the actuating member can be directly charged with the pressure of the fluid, i.e. during operation of the pump, it is charged with the pressurized fluid. In preferred embodiments, in particular in embodiments in which it is charged with the pressurized fluid, the actuating member is charged with an elasticity force which counteracts the actuating force. The elasticity force is generated by an elasticity member, preferably a mechanical spring.
[0009] The actuating member is in sliding contact with the casing, since the casing forms a track and the actuating member forms an actuating member sliding surface, and the actuating member is guided in the sliding contact by the track by means of its sliding surface. The actuating member can also additionally be guided in other ways, for example in a pivoting joint, however it is more preferably guided by the track only.
[0010] In accordance with the exemplary embodiment of the invention, the actuating member sliding surface and/or the track is/are formed from a sliding material. The sliding material can in particular be a plastic, a ceramic material, a nitride, a nickel-phosphorus compound, a sliding varnish, namely a lubricating varnish or solid film lubricant, a DLC coating, a Ferroprint coating or a nano-coating. The sliding material can form a surface coating. If the sliding material is a plastic, the relevant component—i.e. a casing portion forming the track, or the actuating member—can consist exclusively or at least substantially of the sliding material. In preferred embodiments, both the actuating member sliding surface and the track consist of a sliding material, either each of the same sliding material or each of a different sliding material. However, wear is also reduced even if only the actuating member sliding surface or only the track consists of the sliding material, wherein using the sliding material for the actuating member sliding surface is preferred.
[0011] The invention is based on the insight that furrowing, or conversely also adhesion, can be decisive for wear. Adhesion can in particular be the frictional mechanism which determines wear when the friction partners which are in sliding contact are so smooth that the frictional mechanism takes a back seat to furrowing or abrasion. It has for instance been established for adjustable external toothed wheel pumps that the actuating members arranged facing the front faces of the delivery rotor which can be axially moved, i.e. the two actuating pistons, are subject to considerable oscillating frictional wear. The adjusting movements required for setting the delivery volume are too slow to be causing the oscillating frictional wear. However, the adjusting movements are superimposed with oscillations having short strokes as compared to the varying movements and a substantially higher frequency. This therefore causes adhesion between the sliding surfaces of the actuating members and the track of the pump casing, resulting locally in material welding, which breaks away due to the adjusting movements. In accordance with the invention, the sliding partners—i.e. the sliding surface of the one or more actuating members and the one or more tracks of the casing—are configured such that the adhesion tendency in the friction system is significantly reduced as compared to the surfaces made of aluminum alloys which are usual for the sliding partners. The sliding material is advantageously chosen to exhibit an adhesion energy or free surface energy which is at most half the adhesion energy of pure aluminum. This condition is fulfilled in particular by plastic materials and ceramic materials, preferably metal oxide ceramics, but also by the other sliding materials cited above. The adhesion energy or free binding energy increases with the density of free electrons. Accordingly, the requirement for a low adhesion energy is fulfilled by materials having a low density of free electrons.
[0012] Heat-resistant thermoplasts are one group of materials which are particularly suitable as the sliding material. The one or—as applicable—more polymers of the plastic sliding material are advantageously modified to lubrication, i.e. the plastic contains a sliding additive which improves its sliding properties. Such a sliding material is also highly suitable in cases in which only one of the sliding partners of the friction system consists of a sliding material. A preferred sliding additive is graphite. Alternatively, a polymer from the group of fluoropolymers may above all be considered as a sliding additive. A preferred example from this group is polytetrafluoroethylene (PTFE). Particularly preferably, both graphite and at least one fluoropolymer, preferably PTFE, are added to the polymer, copolymer, polymer mixture or polymer blend, as sliding additives. The proportion of the sliding additive should be at least 10% by weight in total; preferably, the proportion of the sliding additive is 20±5% by weight in total. If different materials form the sliding additive, the individual proportions should be at least substantially the same. Plastic sliding materials containing 10±2% by weight of graphite and 10±2% by weight of fluoropolymer are for instance preferred. Adding fibrous material is also regarded as being advantageous, wherein carbon fibers are preferred as the fibrous material. Glass fibers should not be added, since they can form fine needle points on the surface of the sliding layer formed from the sliding material and therefore impair its sliding properties. The plastic sliding material preferably contains 10±5% by weight, more preferably 10±3% by weight of fibrous material.
[0013] Plastics which are preferred as the sliding material contain 70±10% by weight of polymer material. Although polymer mixtures or polymer blends may in principle be considered as the base material, the plastic sliding material preferably contains only one type of polymer. Polymers, with their long hydrocarbon chains, have a very low density of free electrons and also correspondingly few free spaces for free electrons of the sliding partner. Amorphous polymers, with their convoluted chains of molecules, are particularly advantageous in this regard. The degree of crystallinity of the polymer material should be as low as possible. Conversely, the polymer material should not have any practically significant entropy elasticity. The minimum working temperature should be around −40° C., preferably below this. The permanent working temperature should be at least +150° C. Within this range of working temperatures, a low creeping tendency, sufficient mechanical stability and dimensional stability are required. For its use in vehicle manufacturing, the plastic sliding material should also be resistant to fuel. Resistance to the fluid delivered should be a general requirement. It is also advantageous if the sliding material also has the ability to embed or absorb hard particles which can be created by furrowing, i.e. attrition. Preferred polymer materials are:
polysulphone (PSU) or in particular polyether sulphone (PES), and copolymerides of PES and polysulphone (PSU); polyphenylene sulfide (PPS); polyether ketones, namely PAEK, PEK or in particular PEEK; polyphthalamide (PPA); and polyamide (PA).
[0019] In preferred first embodiments, the actuating member is formed from the plastic sliding material, preferably by injection molding. In such embodiments, it preferably consists of the plastic. In principle, however, inserts can be embedded in the plastic; in this sense, the actuating member at least substantially consists of the plastic sliding material. Instead of the actuating member, a casing portion which forms the track can also formed from the plastic sliding material, preferably by injection molding and from the plastic alone or at least substantially from the plastic, in the above sense. In a comparatively preferred variant, the casing is formed from a metal, preferably light metal, and the track is formed by an insert, preferably a bushing, consisting of the plastic sliding material. In principle, the actuating member and a casing portion which forms the track, in particular an insert, can also each be formed from the plastic sliding material. Within the context of the first embodiments, it is particularly preferred if only the actuating member consists at least substantially of the plastic sliding material, while the track is formed only as a surface coating by a plastic sliding material or, as applicable, another sliding material, or is formed as a non-coated metal surface.
[0020] In preferred second embodiments, at least one of the sliding surfaces which are in sliding contact is formed by a thin sliding layer. The actuating member and/or the casing portion forming the track consists or consists of another material below the superficial sliding layer, i.e. a substrate material. The substrate material can in particular be a metal, preferably a light metal. Prospective light metals are above all aluminum, aluminum alloys and magnesium alloys. In the second embodiments, both sliding surfaces are preferably formed as superficial sliding layers, each from a sliding material which has a significantly lower adhesion energy than aluminum or magnesium. If only one of the sliding surfaces of the two sliding partners consists of the sliding material, it is preferably the sliding surface of the actuating member. A combination of a first and second embodiment is also advantageous, wherein the actuating member or the casing portion forming the track, preferably an insert, at least substantially consists of plastic and the other part comprises a surface layer made of the sliding material, for example also made of plastic or made of a ceramic material.
[0021] The superficial sliding layer can be formed by applying the sliding material or by modifying the substrate material. Plastic sliding material is applied; preferably, the plastic is injection-molded around the blank formed from the substrate material. The plastic sliding material should exhibit a longitudinal thermal expansion which comes as close as possible to the longitudinal expansion of the substrate material. Modifying light-metal substrate materials, by contrast, creates a metal-oxide ceramic sliding layer or a nitride layer. If the substrate material is aluminum or an aluminum alloy, the sliding layer is preferably obtained by anodisation. Anodisation can in particular form a so-called Hardcoat® sliding layer or more preferably a so-called Hardcoat® smooth sliding layer. Hardcoat® smooth electrolytes consist of a mixture of oxalic acid and additives. Sulfuric acid (H 2 SO 4 ) is generally used to manufacture Hardcoat® layers. Anodic oxidation methods for forming a metal-ceramic sliding layer comparable to Al 2 O 3 sliding layers are also known for magnesium and magnesium alloys as the substrate material, for example the so-called DOW method. PTFE is preferably dispersed in the ceramic sliding layer; the ceramic is impregnated with PTFE, so to speak.
[0022] As already mentioned, the casing or also only a casing portion forming the track can in particular be formed from aluminum or an aluminum alloy. The casing or the relevant casing portion is preferably cast. The aluminum alloy is therefore preferably a cast aluminum alloy. If the actuating member does not at least substantially consist of plastic sliding material, it is preferably formed from aluminum or an aluminum alloy, preferably a cast alloy, preferably by casting and then extruding or by sintering and calibrating. It holds for both the casing portion and the actuating member that the respective aluminum alloy preferably contains 10±2% by weight of silicon. The respective alloy also preferably contains copper, though at a proportion of at most 4% by weight, preferably at most 3% by weight. It can furthermore contain a smaller proportion of iron. The casing portion, and preferably other portions of the casing, is or are preferably formed by sand casting or die casting, wherein die casting is primarily appropriate for larger-volume runs and sand casting is primarily appropriate for smaller-volume runs. Chill casting can also be used instead of sand casting. A particularly preferred alloy for the casing portion and also for the casing as a whole is AlSi8Cu3 if it is formed by sand casting or chill casting, and AlSi9Cu3 plus a small proportion of iron if it is formed by die casting.
[0023] Nitrides which are preferred as the sliding material are titanium carbon nitride (TiCN) and in particular nitrided steel. Steels having a high chromium content, preferably with a proportion of molybdenum and also preferably with a proportion of vanadium, for example 30CrMoV9, are in particular used as nitrided steels. TiCN is used as a surface coating on a light-metal substrate material. If nitrided steel forms the sliding material, the corresponding steel is preferably the substrate material. For instance, the actuating member can in particular be formed from the steel and the actuating member sliding surface can consist of the nitrided steel. A particularly preferred tribological pairing is Hardcoat® ceramic or Hardcoat® smooth ceramic for one sliding partner and nitrided steel for the other sliding partner. The ceramic sliding material of this pairing can contain PTFE, however low wear is also achieved when using the ceramic only. A tribological pairing of Hardcoat® ceramic or Hardcoat® smooth ceramic with sintered tin bronze is also an alternative, although only a conditionally preferred alternative with regard to its thermal expansion.
[0024] A DLC (diamond-like carbon) coating, and then in particular a tungsten carbide coating, also has a wear-reducing effect. A DLC sliding coating can in particular be produced by plasma-coating.
[0025] Sliding varnishes are also suitable sliding materials, wherein it also holds for sliding varnishes that, while wear is reduced even if only one of the sliding partners is coated, a sliding varnish coating on both sliding partners of the friction system is however preferred. A combination of a sliding varnish for one sliding partner and a plastic material for the other sliding partner is also an advantageous solution. The sliding varnish consists of an organic or inorganic binder, one or more solid lubricants and additives. MoS 2 , graphite or PTFE, individually or in combination, may in particular be considered as the solid lubricant. Before being coated with the sliding varnish, the surface to be coated is pre-treated, expediently by forming a phosphate layer on the surface to be coated. One particular sliding varnish is Ferroprint, which contains fine steel tips as the solid lubricant.
[0026] If a nano-coating forms the sliding material, nano-phosphorus compounds can in particular form the sliding layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Example embodiments of the invention are explained below on the basis of figures. Features disclosed by the example embodiments, each individually and in any combination of features which are not mutually exclusive, advantageously develop the subjects of the embodiments described above. There is shown:
[0028] FIG. 1 is a cross-sectional view of a delivery chamber of an external toothed wheel pump comprising two delivery rotors in toothed engagement; and
[0029] FIG. 2 is a longitudinal cross-sectional view of the external toothed wheel pump.
DETAILED DESCRIPTION
[0030] FIG. 1 shows a cross-section of an external toothed wheel pump. In a pump casing comprising a casing portion 3 and a cover 6 ( FIG. 2 ), a delivery chamber is formed in which two externally toothed delivery rotors 1 and 2 in the form of externally toothed wheels are mounted such that they can rotate about parallel rotational axes R 1 and R 2 . The delivery rotor 1 is rotary driven, for example by the crankshaft of an internal combustion engine of a motor vehicle. The delivery rotors 1 and 2 are in toothed engagement with each other, such that when the delivery rotor 1 is rotary driven, the delivery rotor 2 mating with it is also rotationally driven. An inlet 4 feeds into the delivery chamber on a low-pressure side, and an outlet 5 on a high-pressure side, for a fluid to be delivered, preferably lube oil for an internal combustion engine. The casing portion 3 forms a radial sealing surface 9 which faces each of the delivery rotors 1 and 2 in the radial direction and encloses the respective delivery rotor 1 or 2 circumferentially, forming a narrow radial sealing gap. For the delivery rotor 1 , the casing 3 , 6 also forms an axial sealing surface on each front face of the delivery rotor 1 , axially facing it, of which the sealing surface 7 can be seen in FIG. 1 . Another axial sealing surface is formed axially facing each of the two front faces of the delivery rotor 2 , of which the sealing surface 17 can be seen in the cross-section in FIG. 1 .
[0031] By rotary driving the delivery rotors 1 and 2 , fluid is suctioned into the delivery chamber through the inlet 4 and, in the tooth gaps of the delivery rotors 1 and 2 , delivered through the respective enclosure to the high-pressure side of the delivery chamber, where it is delivered through the outlet 5 to the consumer—in the assumed example, the internal combustion engine. During the delivery action, the high-pressure side is separated from the low-pressure side by the sealing gaps formed between the delivery rotors 1 and 2 and the sealing surfaces cited, and by the toothed engagement of the delivery rotors 1 and 2 . The delivery rate of the pump increases in proportion to the rotational speed of the delivery rotors 1 and 2 . Since, above a certain limiting rotational speed, the internal combustion engine—assumed as the consumer by way of example—absorbs less lube oil than the pump would deliver in accordance with its characteristic curve which increases in proportion to the rotational speed, the delivery rate of the pump is regulated above the limiting rotational speed. For regulation, the delivery rotor 2 can be moved axially, i.e. along its rotational axis R 2 , back and forth relative to the delivery rotor 1 , such that the engagement length of the delivery rotors 1 and 2 , and correspondingly the delivery rate, can be changed.
[0032] In FIG. 2 , the delivery rotor 2 assumes an axial position exhibiting an axial overlap, i.e. an engagement length, which has already been reduced as compared to the maximum engagement length. The delivery rotor 2 is part of an adjusting unit consisting of a bearing journal 14 , an actuating member 15 , an actuating member 16 and the delivery rotor 2 which is mounted on the bearing journal 14 between the actuating members 15 and 16 such that it can rotate. The bearing journal 14 connects the actuating members 15 and 16 to each other, secure against rotation. The actuating member 16 forms the axial sealing surface 17 facing the delivery rotor 2 . The actuating member 15 forms the other axial sealing surface 18 . The entire adjusting unit is mounted, secured against rotation, in a shifting space of the pump casing 3 , 6 , such that it can shift axially back and forth.
[0033] The casing is formed by the casing portion 3 and the casing cover 6 which is fixedly connected to it. The casing cover 6 is formed with a base, the front face of which facing the delivery rotor 1 forms the sealing surface 7 . On the opposite front face, the casing portion 3 forms the fourth axial sealing surface 8 which axially faces the delivery rotor 1 . The side of the sealing surface 8 facing the adjusting unit is provided with a circular segment-shaped cutaway for the actuating member 15 . The side of the actuating member 16 facing the delivery rotor 1 is provided with a circular segment-shaped cutaway for the base 6 forming the sealing surface 7 . Apart from the respective cutaway, the sealing surface 7 corresponds to the sealing surface 8 , and the sealing surface 17 corresponds to the sealing surface 18 .
[0034] The adjusting members 15 and 16 of the example embodiment are adjusting pistons. The shifting space in which the adjusting unit can be moved axially back and forth comprises a partial space 10 which is limited by the rear side of the actuating member 15 and a partial space 11 which is limited by the rear side of the actuating member 16 . The partial space 11 is connected to the high-pressure side of the pump and is constantly charged with pressurized fluid diverted there, thus acting on the rear side of the actuating member 16 . A mechanical pressure spring is arranged in the space 10 as an elasticity member 12 , the elasticity force of which acts on the rear side of the actuating member 15 . The elasticity member 12 counteracts the pressure force acting on the actuating member 16 in the partial space 11 . The regulation of such external toothed wheel pumps is known and does not therefore need to be explained. The regulation can in particular be configured in accordance with DE 102 22 131 B4.
[0035] If the axial sealing surfaces 7 , 8 and 17 , 18 were circumferentially smooth and the axial sealing gaps correspondingly circumferentially narrow, fluid on the high-pressure side in the engagement region of the delivery rotors 1 and 2 would be squeezed, i.e. compressed even beyond the pressure of the high-pressure side, and delivered to the low-pressure side. A drive output is consumed for squeezing the fluid, and a delivery flow pulsation is also associated with the particular compression of the fluid and its transport through the toothed engagement.
[0036] In order to eliminate the disadvantages cited, the sealing surfaces 7 , 8 , 17 and 18 are each provided with a relieving pocket on the high-pressure side. Of the four pockets, the pockets 7 a and 17 a can be seen in FIG. 1 . Relieving pockets are only formed on the high-pressure side. The casing portion 3 guides the actuating members 15 and 16 in a sliding contact. For the sliding contact, the casing portion 3 forms a track 3 a and the casing portion 3 together with the cover 6 forms a track 3 b , 6 b . The actuating members 15 and 16 each form an actuating member sliding surface 15 a and 16 a at their outer circumferential surface. More specifically, the track 3 a and the actuating member sliding surface 15 a on the one hand, and the track 3 b , 6 b and the actuating member sliding surface 16 a on the other hand, are in sliding contact. In the prior art, it is usual to produce the casing 3 , 6 and the actuating members 15 and 16 from light metal alloys. In the friction systems formed from the tracks 3 a and 3 b , 6 b on the one hand and the actuating member sliding surfaces 15 a and 16 b on the other hand, a particular sliding material forms at least one of each of the sliding partners of the relevant friction system, wherein in the friction system 3 a / 15 a , either the track 3 a or the actuating member sliding surface 15 a can be formed by the sliding material. The same sliding material can also form both the track 3 a and the actuating member sliding surface 15 a . Lastly, the two sliding surfaces 3 a and 15 a can each be formed by a different sliding material. The same applies in relation to the other friction system 3 b , 6 b / 16 a . If only one of the sliding partners of the respective friction system consists of the sliding material, the same sliding material is expediently used in each case. If both friction partners consist of a sliding material, the actuating member sliding surfaces 15 a and 16 b are each formed by the same sliding material or the tracks 3 a , 3 b and 6 b are each formed by the same sliding material.
[0037] Although in principle one of the sliding partners in the respective friction system can consist of a metal alloy, preferably a light metal alloy, it is in accordance with preferred example embodiments if each of the sliding partners is formed by a particular sliding material having a low adhesion energy. The sliding material of the sliding partners of the respective friction system can be the same or can be different. The actuating members 15 and 16 can be formed entirely from the sliding material, or can be formed from a substrate material, preferably a light metal alloy, and each superficially comprise a sliding layer made of the sliding material. The casing—in the example embodiment, the casing portion 3 and the cover 6 —can also be formed from plastic, however in preferred example embodiments, at least the casing portion 3 and preferably the cover 6 are cast from a metal alloy, preferably a light metal alloy. Aluminum alloys may in particular be considered as the light metal. Preferred examples are given below:
Example 1
[0000]
casing portion 3 and cover 6 : each made of an AlSi9Cu3(Fe) die cast
actuating members 15 and 16 : PES compound: 10% by weight of carbon fibers, 10% by weight of graphite, 10% by weight of PTFE, remainder PES (e.g. ULTRASON®)
[0040] In Example 1, the casing portion 3 and the cover 6 are each formed from the same aluminum alloy, namely AlSi9Cu3, by die casting. The alloy can contain a small proportion of iron. The tracks 3 a , 3 b and 6 b are obtained in an exact fit by being mechanically machined. The actuating members 15 and 16 are each formed entirely from the specified plastic sliding material. The sliding surfaces 15 a and 16 a are produced in an exact fit by being mechanically machined.
Example 2
[0000]
casing portion 3 and cover 6 : each made of an AlSi9Cu3(Fe) die cast
actuating members 15 and 16 : PES compound: 10% by weight of carbon fibers, 10% by weight of graphite, 10% by weight of PTFE, remainder PES (e.g. ULTRASON®)
tracks 3 a , 3 b and 6 b : coated with plastic or sliding varnish modified to lubrication
[0044] Except for the tracks 3 a , 3 b and 6 b , Example 2 corresponds to Example 1. Unlike Example 1, however, each of the tracks 3 a , 3 b and 6 b is formed by a sliding layer of plastic sliding material or sliding varnish. The plastic sliding material can in particular be the material of the actuating members 15 and 16 .
Example 3
[0000]
casing portion 3 and cover 6 : each made of an AlSi9Cu3(Fe) die cast
actuating members 15 and 16 : extruded parts made of a cast aluminum semi-finished product as the substrate material, for example AlSi8Cu3
sliding surfaces 15 a and 16 a : PES compound: 10% by weight of carbon fibers, 10% by weight of graphite, 10% by weight of PTFE, remainder PES (e.g. ULTRASON®)
[0048] The casing portion 3 and the cover 6 correspond to Example 1. The actuating members 15 and 16 each consist of the same aluminum alloy, preferably AlSi8Cu3. They are formed from a cast semi-finished product of the aluminum alloy, by extrusion. At least the circumferential surfaces are then each provided with a sliding layer of the plastic sliding material. Instead of forming the blanks of the actuating members 15 and 16 by extrusion, the blanks can be formed by sintering and calibrating. The extruded or calibrated blanks are heated and the plastic sliding material is injection-molded around them in a die, preferably completely enclosing them.
Example 4
[0049] casing portion 3 and cover 6 : each made of an AlSi9Cu3(Fe) die cast
tracks 3 a , 3 b and 6 b : Hardcoat® smooth (Hardcoat® smooth sliding layer, preferably impregnated with PTFE)
actuating members 15 and 16 : extruded parts made of a cast aluminum semi-finished product as the substrate material, for example AlSi8Cu3
sliding surfaces 15 a and 16 a : Hardcoat® smooth (Hardcoat® smooth sliding layer, preferably impregnated with PTFE)
[0050] The casing portion 3 and the cover 6 correspond to Example 1. The actuating members 15 and 16 each consist of the same aluminum alloy, preferably AlSi8Cu3. They are either formed from a cast semi-finished product by extrusion or alternatively by sintering and calibrating. The actuating member blanks are then anodized at least on their circumferential surface forming the respective sliding surface 15 a and 16 a . A mixture of oxalic acid and additives is used as the electrolyte, such that a sliding layer of Al 2 O 3 Hardcoat® smooth is formed on each of the outer circumferential surfaces. The sliding layer is preferably impregnated with PTFE. The tracks 3 a , 3 b and 6 b are formed in the same way, also each as a Hardcoat® smooth sliding layer, preferably as a PTFE-impregnated sliding layer.
[0051] In a modification, one of the two sliding partners or also both sliding partners can each be formed as a Hardcoat® sliding layer, also preferably as a PTFE-impregnated sliding layer.
Example 5
[0052] casing portion 3 and cover 6 : each made of an AlSi9Cu3(Fe) die cast
tracks 3 a , 3 b and 6 b : Hardcoat® sliding layer
actuating members 15 and 16 : steel, for example 30CrMoV9, as the substrate material
sliding surfaces 15 a and 16 a : nitrided steel
[0053] The casing portion 3 and the cover 6 correspond to Example 1 and, once formed, are anodized such that the tracks 3 a , 3 b and 6 b are obtained as an Al 2 O 3 Hardcoat® (Hardcoat® sliding layer). The Hardcoat® sliding layer can be impregnated with PTFE. The actuating members 15 and 16 are formed from steel and nitrided on their surface, at least on their outer circumferential surfaces.
Example 6
[0000]
casing portion 3 and cover 6 : AlSi8Cu3 sand cast or chill cast
actuating members 15 and 16 : extruded parts made of a cast aluminum semi-finished product as the substrate material, for example AlSi8Cu3
sliding surfaces 15 a and 16 a : Hardcoat® smooth (Hardcoat® smooth sliding layer)
[0055] The casing portion 3 and the cover 6 are each formed from AlSi8Cu3 by sand casting or chill casting. The tracks 3 a , 3 b and 6 b are produced in an exact fit by being mechanically machined. The actuating members 15 and 16 are each formed from a cast aluminum semi-finished product by extrusion, and anodized. A mixture of oxalic acid and additives is used as the electrolyte, such that a sliding layer of Al 2 O 3 Hardcoat® smooth (Hardcoat® smooth sliding layer) is formed on each of the outer circumferential surfaces. The Hardcoat® smooth sliding layer preferably contains PTFE.
[0056] In a modification, a Hardcoat® ceramic or Hardcoat® smooth ceramic also forms the tracks 3 a , 3 b and 6 b , wherein here, too, the ceramic can advantageously be impregnated with PTFE.
[0057] The method of manufacture and choice of materials in the last example embodiment is particularly suitable for smaller-volume runs, while forming the casing portions 3 and 6 by die casting is the better choice for large-volume runs. Metal-ceramic sliding layers are particularly suitable for use in friction systems comprising a light-metal sand cast structure or chill cast structure or light-metal cast alloys in general which are solidified at or near thermodynamic equilibrium. In conjunction with die cast parts as sliding partners, the α-mixed crystals—for example AlSi—of the die cast structure, which are smaller due to the shorter cooling time, cause problems which for metal-oxide ceramic sliding layers act as fine abrasive grains. If one of the sliding partners comprises a die cast structure or a metastable phase in general on its sliding surface, then heat-resistant thermoplasts modified to lubrication are the better choice, or each of the two sliding partners should comprise a Hardcoat® sliding layer or Hardcoat® smooth sliding layer. Even for sand cast structures or chill cast structures, however, both sliding partners preferably consist of a sliding material having a low adhesion energy.
[0058] In the foregoing description, preferred embodiments of the invention have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principals of the invention and its practical application, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly, legally, and equitably entitled to.
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A rotary pump having a variable delivery volume, comprising: a casing; a delivery chamber formed in the casing; at least one delivery rotor which is rotatable in the delivery chamber; an actuating member which is arranged facing a front face of the delivery rotor or surrounds the delivery rotor, and is moveable in the casing for adjusting the delivery volume; the actuating member chargeable with an actuating force which is dependent on a fluid requirement; a track which is formed in the casing and guides the actuating member on an actuating member sliding surface in a sliding contact; and a sliding material which forms at least one of the track and the actuating member sliding surface.
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This application is a continuation-in-part of U.S. patent application Ser. No. 07/781,162filed Jan. 7, 1992, which claims the priority of International Application No. PCT/EP91/00,403, filed Mar. 4, 1991, and which claims the priority of Belgian Application No. 9,000,251, filed Mar. 7, 1990.
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates in general to a tightly sealable fold collar or bellows enabling a quick assembly for protecting thereby universal joints, steering and guiding axle couplings, which bellows possesses a longitudinal sealing closure and is particularly suitable for protecting swing axle rotating joints (cardan joints) of motor vehicles.
More in particular the present invention concerns a protective bellows adapted to be quickly installed on a homokinetic "CARDAN" type universal joint of motor vehicles, said bellows comprising two bodies in the form of shell halves which are assembled together by means of a fitting system with simultaneous gluing.
On motor vehicles the bellows covering the cardan joint is of hermetically closed design for grease- and oil tightness such that the joint is protected against damage and corrosion. The conventional CARDAN bellows being constructed as a one-part body necessitates its installing to be carried out simultaneously with the assembly of the universal joint and hence its replacement in case of a defect, for instance a cut or a tear or a porosity leak, compels the operator to entirely take off the cardan joint, which gives rise to a considerable loss of time.
In order to overcome this drawback it has been recommended to manufacture a protective bellows having a sealable closure of the kind with snap-locked jointing edges. Such a bellows allowing rapid installment is known for instance from U.S. Pat. No. 4,558,869.
These models as a whole comprise a lateral opening extending in the longitudinal direction for allowing the entry of the coupling axle without need of disconnecting the cardan joint. They are assembled together by an interlocking system with "U"-shaped edge and matching lip, the hole being sealed by wedding or gluing. The joint of conventional design with "U"-shaped edge and inserted lip has the disadvantage of causing a local overthickness and a sudden change in the rigidity of the bellows body. These jointing closures necessarily have a lower flexibility than that of the bellows shell and as a consequence the latter no longer provides in every direction the same flexibility or fitness to dissipate the alternating compressive and tensile bending stresses when in use.
Moreover temperature variations, particularly in winter when ambient temperatures may be as low as minus 20° C. or even lower, give rise to stiffening of the plastic or elastomeric material of the tubular body, which shows a greatly pronounced increase and variation of ridigity in the region of the closing joint.
In addition to this problem the known bellows generally display an interlocking closure of rather poor design which is not adapted to ensure a sufficiently long service life of the welded or glued joint, and this in the light of the geometry of the interconnected edges and the tenacity of the finished closure. Thus it has been established that known protective bellows are not satisfactory from the viewpoint of durability and watertightness. In normal use conditions the jointing closure itself tends to loosen prematurely. In extreme conditions (low temperatures) the bellows looses at the place of the interlocking closure its elasticity needed withstand high loads occurring when applying full lock upon turning the vehicle, which may make appear fissures through which grease will escape such that the cardan joint is bound to degrade in the long run.
On the other hand the U-shaped interlocking closure extending longitudinally from one bellows end to the opposite end, as shown opened for closing the bellows after the latter has been positioned, must sustain in rainy weather the direct hit of water projected in continuous jets which are augmented by the speed of rotation and hence increase the penetration force of the water. Moreover, the glue used in the gluing step after the interlocking operation exerts a dissolving action upon the interlocked tongue and a welding effect by solvent aided fusion of the material. A drawback thereof consists in the fact that, when the operator doesn't watch carefully the overflowing of the solution, the latter may cause dissolution of the bellows material on places when it's not desirable. As a result perforations may develop at solvent deposit spots, so that the bellows is no longer watertight.
In addition it has to be understood that for adapting the so-called standard system in order to be realizable on all types of European motor vehicles, it's necessary to have different opening diameters available for the bellows, namely one opening end for the wheel side the diameter of which may vary from 66 mm to 91 mm, and likewise for the axle or tube side with a diameter varying from 20 to 40 mm. A disadvantage of existing rapid-assembling protective bellows consists in the absence of opening diameters which are adaptable for vehicles having a diameter which is larger than 81 mm on the wheel side.
OBJECTS AND SUMMARY OF THE INVENTION
The present invention has for its object to overcome these drawbacks and to provide a novel and particularly efficient design of a rapid-assembly bellows that is adaptable to any type of universal cardan type joints of motor vehicles.
Another object of the invention is to solve all the above mentioned problems, including the selection of the raw material where the bellows is composed of and the glue application.
The invention further provides a method of assembling or installing a bellows according to the invention upon a cardan type joint.
The present invention having as its main object to overcome the disadvantages due to the closure systems and forms of known bellows, thus also proposes a solution to the problems linked with the materials constituting the jointing closure of the bellows.
Still another object of the invention consists in providing a rapid-assembly bellows of a geometry which is easily adaptable to the coupling axle diameters around which the bellows is installed. In addition, the bellows of the invention aims to remedy the problem of water projections in continuous jets, e.g., in rainy weather, which are enhanced by the revolving speed and which tend to deteriorate the side edges of the interlocking closure, thereby finally weakening and breaking the watertight sealing closure protecting the cardan joint. In order to overcome the above cited problems, the invention proposes a protective bellows for universal joints which is essentially characterized by the combination of technical features as follows: Rapid-assembly sealing bellows for protecting jointed couplings such as transmissions, guiding and steering joints, in particular so-called cardan or universal joints of motor vehicles, the bellows being essentially a corrugated tubular body (with entry and exit sleeves) from a material of adequate flexibility, comprising at least one jointing closure formed by lateral interlocking of the near divided edges running in the longitudinal direction from entry to exit of the tubular body, each of the edges forming respectively a U-shaped interlock housing and an interlocking tongue for being received into the housing, characterized in that the open end of the interlock housing comprises an upper covering leg which is inclined in the upward direction and a supporting sole forming a lower covering surface which greatly extends beyond the upper surface and which is inclined in the downward direction, and in that the interlocking tongue, which is closely received into the U-shaped housing by the matching interior surfaces thereof and presents the same surface inclinations as the housing but in opposite sense, comprises depth abutments which lean respectively against the open end face of the upper leg and against the end face of the lower supporting sole, and in that the opposite outer faces of the interlock housing and the entering tongue, when assembled, are inclined in the opposite direction so as to form facing breaker surfaces which act as jet breakers of projected rain water in both rotational directions.
Preferred embodiments of the present invention are defined as set forth in detail below.
The bellows according to the invention may be formed of suitable material possessing the flexibility and tenacity required for the envisaged application and having in addition a sufficient general corrosive resistance and also withstanding attack by hydrocarbons, in particular motor oils, brake circuit oils, motor fuel, etc . . . .
Although a bellows may also be manufactured from a corrosion resistant metallic material, it's recommended to utilize plastic or synthetic materials, such as for example polyethylenes, polypropylenes and preferably thermoplastic elastomeric material, and most preferably thermoplastic polyurethanes.
A particularly preferred material is PEBAX 4033, which is a member of the thermoplastic elastomers family of the type polyether-block-amide. The bellows of this invention may be shaped by any suitable process of making, such as for instance by cast/molding, by blowing or by injection molding. A preferred bellows material like PEBAX 4033 is advantageously shaped by injection molding.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics and advantages of the invention will be better understood from the following description and the exemplified embodiments. The invention will be described into more detail with the help of a preferred embodiment illustrated in the annexed drawings, without limiting the invention thereto, in which:
FIGS. 1a and 1b are axial cross-sectional views of the two shell bodies forming together a bellows according to the invention.
FIGS. 2a-2f show transverse cross-sectional views of an interlocking joint or closure of a bellows according to the invention.
FIG. 3 shows different technical details of an interlocking closure of this invention.
FIGS. 3a-3c illustrate portions of FIG. 3 on an enlarged scale.
FIG. 4 is a longitudinal cross-sectional view of a bellows shell half, showing in more detail the finishing shape of the opposite closed and faces.
FIGS. 4a and 4b illustrate portions of FIG. 4 on an enlarged scale.
FIGS. 5a-5b illustrate a sealing joint ring useful for adapting the bellows entries to given diameters of wheel and/or coupling axles to be protected.
FIGS. 6a-6b show additional improvement aspects to the interlocking jointing closure.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 there is shown a bellows exemplifying a preferred embodiment of the invention. The bellows is composed of two shell body halves (1) and (2) having a convenient corrugated or wave form. After assembling the two shells by interlocking their corresponding respective longitudinal side edges (3,4') and (4,3'), the so installed and sealed shells form a resilient and oiltight bellows around a cardan shaft coupling.
The two opposite ends (5,6) of the installed bellows form tubular attachment sleeves for receiving and enclosing the two connected sides (e.g., wheel, shaft) of the protected cardan coupling joint.
The inside diameters (9, 10) of the coupling sleeves are adapted and/or are subsequently adaptable to the diameters of the cardan coupling components. The peculiar concept of the actual longitudinal jointing closure of the bellows or its two opposite closures in the case of the preferred embodiment of the invention composed of two hemispherical shell halves, offers novel technical elements of an unexpected effectiveness which form the basis of the present invention. These elements are shown into more detail in FIGS. 2 and 3.
Unlike conventional closures where the two longitudinal side edges to be connected consist of a simple U-shaped channel and a lip that are mutually interlocked, the jointing closure according to the invention is characterized by a particular construction of the two edges forming the interlocking sealing closure. The FIGS. 2a to 2d, illustrating different transverse cross-sectional views of a longitudinal jointing bellows closure according to the invention, show the technical details by which the drawbacks are solved occurring with a common interlocking closure of adjacent fitting edges. The sealing connection between the semi-tubular parts of the two end sleeves (5,6) disposed at each end opening of the corrugated body may also be accomplished by a usual U-shaped interlocking closure.
It should be noted that the terms upper/lower and radially outward/radially inward are used for convenience and clarity when viewing the drawing figures in connection with the written description. As will be readily apparent from looking at the figures, given the overall configuration of the bellows according to the invention, a section of the interlocking closure which extends radially outwardly at one point on the outer surface of the bellows may be extending radially inwardly in a succeeding section.
The longitudinal interlocking structure is formed of an interlock base or housing (11) and of an interlocking tongue element (12). The interlock base (11) which is open ended towards the tongue (12) comprises an upper as viewed in FIGS. 2a-2f (i.e., radially outer) covering leg (19) and a lower (i.e., radially inner) supporting sole (21) having a covering surface (21') extending beyond (i.e., circumferentially past) that of the upper leg surface (19') by an overshoot part (20) of a length (20') being equal to at least a quarter of covering depth (19'). The interlocking tongue (12) which forms the male part of the joint structure, comprises an upper part (22) and a lower part (23) (i.e., radially outward and inward, respectively) which exactly match the internal surfaces (19,21) of the interlock housing. For achieving this, upper part (22), respectively lower part (23) of the tongue are each provided with an edge portion (17, 18) that acts as a depth controlling abutment. Another particularity of the interlocking system concerns the different and opposed inclination (13,14) of the internal covering surfaces (19,21) of the housing (11), and likewise that of the corresponding contact surfaces of upper (22) and lower part (23) of the interlocking tongue (12). The covering surface (19) is inclined at an angle (13) of about 5 to 20 degrees, preferably about 10 degrees, to make the entry of tongue (12) easier. Angle (13) is measured relative to a tangent plane T 1 which extends tangential to the interlocking closure. The supporting sole (21) is sloped at an opposed angle (14) of about 1 to 6 degrees, preferably about 3 degrees of opening, relative to a tangent plane T 2 substantially parallel to tangent plane T 1 , to facilitate the insertion of interlocking tongue (12), see FIG. 2c.
Another advantageous measure for improving the assembled jointing closure according to the invention is the provision of a hit attack angle (24,26), including at about 30 to 50 degrees, preferably about 45 degrees, relative to a tangent plane T 3 on the opposed outer ends (outer closed side of interlock base, resp. interior side of tongue) of the interlock joint. Said inclined surfaces, sloped in opposed directions, have the effect of forming jet breakers, i.e. to counteract in rainy time the water protecting impact that might attack and impair the finished sealing closure. The jet break (24) is operative from the moment on that the rotation is effected in the sense (28). The same effect is obtained for jet breaker (26) inclined relative to a tangent plane T 4 at essentially the same angle as (24) but in the opposite sense, when the rotation is started in the direction (27). The constructional and geometric features by the longitudinally interlocked nesting of the mating side edges of the bellows according to this invention, as described and explained above, result in the formation of a strong and accurate jointing closure, easy to assemble and resistant to projected water.
In addition the geometric shape of the assembled interlocking joint avoids a local overthickness being excessive and too abrupt. In this way the bellows according to the invention has a better flexibility and an improved resistance to alternating flexing loads as compared to bellows of the prior art.
An additional important object of the novel interlocking joint system is to overcome the problems related to welding and/or gluing the constituent near elements of the jointing closure, with the aim of achieving a strong, watertight and durable adhesive connection. For this purpose there is first provided, see FIG. 3, an interlock fitting that is accurate in its depth thanks to abutments (17,18), which enables to achieve a uniform thickness of the adhesive layer joining the glued upper (19,22) and lower (21,23) constituent parts which perfectly fit together in the assembled interlocking structure. In addition the adhesive joint between the covering surfaces possesses at least one security seam in the length direction of the joint assembly. It can be seen that the angle (15) at the entering end face of the tongue (12) has been omitted with the aim of creating an empty space, for example of about 0.1 mm, which will be automatically filled by the applied glue thereby forming a secure joining seam. The angle (16) facing the abutment (17) has the same function as element (15). Although said two seams are largely sufficient, it is still possible to provide a similar seam at the other entering end angle of the tongue and at the lower part of the interlocking tongue facing the abutment (18).
FIG. 4 illustrates a further special feature of the bellows according to the invention. At the two opposite sides of the corrugated bellows body there is the provision of terminal closure walls (31) and (32) which are each disposed at the opposing end faces of the interlocking base (11). These closure walls enable to guide the interlocking tongue (12) during assembly of the shell halves (1) and (2) in such a manner that a shift in the longitudinal direction is avoided, by which snap-locking of the interlocking tongue is obtained without positioning error. The present invention is also aimed at solving the drawbacks related to the difficulty of so-called standard adaptation of the bellows, to allow its installment on all the motor vehicles of type VL and on industrial vehicles. Indeed, the conventionally used bellows have the disadvantage that they are not available in the range of end opening diameters exceeding 81 mm at the wheel entry side.
The present invention overcomes this difficulty by providing a number of base models (for instance four) of rapid-assembly bellows having the following end opening diameters at the wheel side and the shaft entry side.
Model I
Once the two shell halves (1) and (2) are assembled together, the inner diameter of the bellows is 75 mm at the wheel side (10) and 32 mm at the shaft side (9).
Model II
Once the two shell halves (1) and (2) are assembled together, the inner bellows diameter is 78 mm at the wheel side (10) and 45 mm at the shaft side (9).
Model III
Once the two shell halves (1) and (2) are assembled together, the inner bellows diameter is 88 mm at the wheel side and 44 mm at the shaft side.
Model IV
Once the two shell halves (1) and (2) are assembled together, the inner diameter of the bellows is 94 mm at the wheel side and 43 mm at the shaft side.
For these base models of a rapid-assembly bellows there is additionally the provision of joint adapter rings (40), see FIG. 5. The purpose of said adapter rings is on one hand to achieve hermetically closed bellows connections simultaneously at the wheel and the shaft side, and on the other hand to decrease the diameter of the two end openings of the bellows, such that the bellows is capable of a larger range of adaptations or applications.
Hence a wide series of adapter rings of different thicknesses is made available to adapt a bellows model according to demand.
As represented in FIGS. 5a and 5b, the joint ring (40) is of a spherical shape, with a split cut in the axial direction (42,29) for facilitating its installment. It is provided with a circular shoulder element (43,63) which has the function of an exterior abutment. The axial length or width (46,66) is equal to the standard depth of the bellows entry openings (47) and (48). The exterior diameter (45) of the adapter joint is equal to either the inner bellows diameter (10) for the series wheel side joint, or to diameter (9) for the series shaft side joint. Only the inner diameter (44) or the thickness (49) will vary in order to realize the required adaptation.
FIGS. 6a-6b illustrate a few additional improvements to the interlocked jointing structure. As shown in FIG. 6a the upper abutment 17 has a double function of depth control and snap-locking of the inserted tongue 12 which is now retained by a corresponding recess 17' provided in upper leg 19. In this way the assembling operation is rendered still easier and more accurate. More importantly, the applied adhesive will now uniformly harden and form a strong joint in geometrically and mechanically stable conditions.
A further improvement may consist in providing the inclined tongue with a lip shaped small extension, the upper surface of which is nearly parallel to the lower (sole) surface.
FIG. 6b shows a longitudinal cross-section of a bellows shell half provided with the snap-locking add on explained in FIG. 6a. As can be seen the snap-locking measure is provided on the rectilinear parts between the wave crests and roots of the corrugated body. In this way of molding of a more complex body shape is rendered more efficient without losing the technical effectiveness of the additional feature with respect to the interlocking/assembling operation, achievable joint strength and related quality/reliability of the formed sealing connections.
A specific base example of a rapid-assembly bellows according to the invention consists of two hemispherical shell halves of corrugated shape. Their corresponding near edges extending in the longitudinal direction to form the open-ended interlock base and the entering tongue which will be assembled so as to obtain two diametrically opposed longitudinal jointing closures having advantageously the following dimensions:
The interlocking base (11) comprises a covering surface (19) of 3 mm depth at its upper side and a supporting sole of 5 mm length at the lower side. The upper surface (19) is inclined with an opening angle of 10 degrees. The inclination of the sole (21) corresponds to an opening angle of 3 degrees. The upper face (22), resp. lower surface (23) of the interlocking tongue (12) which fit the inner surfaces of the interlock housing (11) feature essentially the same opening angles as indicated above. The attack angle (24,26) has a slope of 45 degrees. The edge angle (15) at the end face of the entering tongue, and also angle (16) located on the end side of the interlock base facing the abutment (17), have been omitted to form an empty space equal to 0.1 mm for the purpose of constituting two adhesive security seams. The outer part (50,50') of abutment (17) may be finished so as to cover the end face of the upper leg of the interlock base (11) over its entire height, thereby forming a smooth and properly closed transition between interlock base and interlocking tongue (see FIGS. 2e and 2f).
Furthermore, the invention concerns the use of a method of installing a rapid-assembly bellows as described hereinabove. The description hereinbelow explains in detail the installment of a bellows according to this invention upon a cardan type universal joint in real practice conditions.
The first operation consists in disassembling the defective bellows from the cardan joint, and in completely cleaning the cardan coupling and recovering it with specific grease.
After this step, the two shell halves (1) and (2) corresponding to the cardan diameters are disposed around the cardan joint.
Then glue is applied into the groove channel (3') of interlock housing (11) of shell half (1). The same operation is carried out on the exit and entry sleeves.
Once this first connection is completed, the bellows presents a longitudinal opening along (3,4') which allows the passage of the coupling shaft. Afterwards the side edges (3) and (4') are assembled together in the same way as (3') and (4). The thus assembled bellows looks then like a conventional watertight cardan bellows.
Then one proceeds with the installment of the sealing joint at the wheel side. The split opening (42) allows its mounting.
The annular joint is encased in opening (10) after application of glue onto parts (63) and (66) and to the two lips of cut opening (42).
The shoulder (63) is disposed onto the outer flange of opening (10). The depth (66) of the sealing ring is inserted so that it is pressed against inner circular ridge (8).
The watertight fit at the shaft side is achieved in the same manner with a sealing ring of a diameter corresponding to that of the shaft. After glue application onto parts (63) and (66) and to the two lips at opening (42) the shoulder (63) is positioned to rest against the exterior flange opening (9). The depth (66) of the sealing ring is fitted so that it's clamped against circular inner ridge (7).
The last operation consists in placing the bellows into its final position for protecting the cardan joint. The two end sleeves of the bellows are secured by means of a tension collar (7,8) of stainless steel.
At the wheel side the collar is retained in a groove (6) and is tensioned for its final tightening. At the shaft side the collar rests in grove (5) and is likewise finally tightened. It will be obvious that the invention is not limited to the exemplifying embodiments described above and illustrated in the drawings, for which invention one could provide several modifications without departing from the scope of the invention as defined in the appending claims.
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Rapid-assembly sealing bellows for protecting jointed couplings such as transmissions, guiding and steering joints, in particular so-called cardan or universal joints of motor vehicles, said bellows being essentially a corrugated tubular body (with entry and exit sleeves) from a material of adequate flexibility, comprising at least one jointing closure formed by lateral interlocking of the near divided edges running in the longitudinal direction from entry to exit of said tubular body, each of said edges forming respectively a U-shaped interlock housing and an interlocking tongue for being received in the housing, characterized in that the open end of the interlock housing comprises an upper covering leg which is inclined in the upward direction and a supporting sole forming a lower covering surface which greatly extends beyond the upper surface and which is inclined in the downward direction, and in that the interlocking tongue, which is closely received into the U-shaped housing by the matching interior surfaces thereof and presents the same surface inclinations as the housing but in opposite sense, comprises depth abutments which lean respectively against the open end face of the upper leg and against the end face of the lower supporting sole, and in that the opposite outer faces of the interlock housing and the entering tongue, when assembled, are inclined in the opposite direction so as to form facing breaker surfaces which act as jet breakers of projected rain water in both rotational directions.
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RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/691,137, titled “METHOD AND APPARATUS FOR APPLYING A RECTILINEAR BIPHASIC POWER WAVEFORM TO A LOAD,” filed on Aug. 20, 2012, which is hereby incorporated herein by reference in its entirety.
BACKGROUND
1. Field
Aspects of embodiments relate generally to methods and apparatus for applying a selected energy impulse to a load without exceeding a safe power level. More particularly, aspects of embodiments relate to applying electrical energy impulses to a patient for therapeutic medical purposes. Even more particularly, aspects of embodiments relate to such methods and apparatus as used in heart defibrillators and/or pacing devices.
2. Discussion of Related Art
Current defibrillator technology stores electrical energy on a capacitor, a passive energy storage element, preparatory to applying a timed, e.g., 10 msec, rectilinear, biphasic energy impulse of a desired magnitude to a patient. In a known defibrillator, energy is applied as a current from the capacitor through the patient in a first phase, i.e., a first direction, for the first 6 msec of the energy impulse, and then as a current also from the capacitor, but through the patient in an opposite phase to the first phase, i.e., in a second direction opposite to the first direction, for the remaining 4 msec of the energy impulse. In order to accommodate a wide range of patients and operating conditions, especially the voltage droop that occurs as energy is transferred out of the capacitor, the capacitor is charged to a higher level of energy than required to produce the desired energy delivery. The above-described, known defibrillator incorporates a resistor network into which excess energy is dissipated by diverting a portion of the current from being delivered to the patient when sensors detect that power levels may be dissipated in the patient that exceed safe power levels.
SUMMARY
According to aspects of an embodiment, a method of applying a rectilinear biphasic electric power waveform to deliver a therapeutic quantity of energy to treat a patient presenting an electrical load is provided. The method comprises storing a quantity of energy substantially equal to and without substantially exceeding the therapeutic quantity of energy on a capacitor, and releasing the stored energy during a first interval in a first direction through the load presented by the patient, in a controlled manner using a boost converter. The method may further comprise releasing the stored energy during a second interval in a second direction through the load presented by the patient. The method may yet further comprise substantially exhausting the stored energy over the first interval and the second interval combined without exceeding a predetermined maximum safe power level when the load presented by the patient is between approximately 25Ω and 200Ω. The method may even yet further comprise releasing a portion of the stored energy from the capacitor into an inductor; releasing the portion of the stored energy from the inductor into the load; and controlling the releasing of the portion of energy into the inductor and into the load in an alternating sequence so as to produce a substantially even flow of energy into the load. According to other aspects of the embodiment, the therapeutic quantity of energy and the first interval are selected to pace a patient whose heart requires pacing impulses. According to yet other aspects of the embodiment, the therapeutic quantity of energy and the first interval are selected to defibrillate a patient whose heart is in fibrillation.
According to aspects of another embodiment, a system for applying a rectilinear biphasic electric power waveform to deliver a therapeutic quantity of energy to treat a patient presenting an electrical load is provided. The system comprises a capacitor having a rated energy storage capacity substantially equal to the therapeutic quantity of energy, a boost converter constructed and arranged to meter energy out of the capacitor as a substantially constant current while a voltage across the capacitor droops due to decreasing energy stored on the capacitor, and an H-bridge circuit constructed and arranged to apply the current to the patient in the rectilinear biphasic electric power waveform. The system may further comprise a controller that controls for a 10 msec combined first and second interval, and a 6 msec first interval.
According to aspects of an embodiment, a system to deliver a therapeutic quantity of energy to a patient load is provided. The system comprises capacitor having a rated energy storage capacity substantially equal to the therapeutic quantity of energy, a boost converter coupled with the capacitor and constructed to release energy from the capacitor at a substantially constant current for a time interval, and an H-bridge circuit coupled with the boost converter and constructed to apply the substantially constant current in a biphasic voltage waveform to the patient load.
According to an embodiment, the boost converter comprises an inductor coupled with the capacitor, a current sensing network, and a solid-state switch coupled between the inductor and the current sensing network. The boost converter may further comprise a controller circuit coupled with the solid state switch and the current sensing network and constructed to cycle the solid state switch. According to other aspects of the embodiment, the current sensing network is constructed to receive a current profile and compare the current profile with a received current from the solid state switch.
According to an embodiment, the H-bridge circuit comprises a plurality of switches, each of the plurality of switches including a circuit constructed to control the switch and to receive a phase profile having a first phase and a second phase. According to other aspects of the embodiment, the H-bridge circuit may further comprise an inverter coupled with at least two of the plurality of switches to invert the phase profile. At least two switches of the plurality of switches may be configured to be in an open state during the first phase and in a closed state during the second phase.
According to an embodiment, the boost converter circuit is further constructed to compensate for voltage droop on the capacitor and variation in the patient load over the time interval. According to an embodiment, the therapeutic quantity of energy and the time interval are selected to defibrillate a patient whose heart is in fibrillation. According to an embodiment, the therapeutic quantity of energy and the time interval are selected to pace a patient whose heart requires pacing impulses.
According to aspects of an embodiment, a method of delivering a therapeutic quantity of energy to a patient load is provided. The method comprises storing a quantity of energy substantially equal to the therapeutic quantity of energy in a capacitor, releasing the quantity of energy at a relatively constant current during a time interval using a boost converter coupled with the capacitor, and delivering a first portion of the quantity energy in a first direction to the patient load using an H-bridge circuit coupled with the boost converter. According to an embodiment, the method further comprises delivering a second portion of the quantity of energy in a second direction to the patient load using the H-bridge circuit.
According to an embodiment, releasing the quantity of the stored energy includes transferring energy to an inductor coupled with the capacitor, and sensing the amount of current through a solid state switch coupled between the inductor and a current sensing network. According to an embodiment, releasing the quantity of energy includes cycling the solid state switch using a controller circuit coupled with the solid state switch and the current sensing network. According to an embodiment, releasing the quantity of energy further includes receiving a current profile and comparing the current profile with the amount of current through the solid state switch using the current sensing network.
According to an embodiment, the H-bridge circuit comprises a plurality of switches and wherein delivering a first portion of the quantity energy in a first direction and a second portion of the quantity of energy in a second direction includes controlling the plurality of switches. According to an embodiment, controlling the plurality of switches includes receiving a phase profile having a first phase and a second phase. According to other aspects of an embodiment, controlling the plurality of switches further includes changing a state of at least 4 switches of the plurality of switches in response to receiving a change in the phase profile from the first phase to the second phase.
According to an embodiment, releasing the quantity of energy includes compensating for voltage droop on the capacitor and variation in patient load impedance over the time interval. According to an embodiment, the method further comprises determining the therapeutic quantity of energy and the time interval to defibrillate a patient whose heart is in fibrillation. According to an embodiment, the method further comprises determining the therapeutic quantity of energy and the time interval to pace a patient whose heart requires pacing impulses.
According to aspects of yet another embodiment, a method of maintaining a target power flow from a charge storage device to a patient load while voltage on the charge storage device droops, comprises inserting a boost converter between the charge storage device and the patient load to maintain power flow. The method may further comprise controlling a current delivered by the boost converter so as to compensate for voltage droop on the charge storage device and so as to compensate for variation in patient load impedance over time.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:
FIG. 1 is a schematic drawing of a circuit for delivering a rectilinear biphasic electric power waveform to deliver a therapeutic quantity of energy to treat a patient presenting an electrical load;
FIG. 2 is a graph of electrical waveforms produced by the circuit of FIG. 1 over a period of time with a patient load of 25Ω;
FIG. 3 is a graph of electrical waveforms produced by the circuit of FIG. 1 over a period of time with a patient load of 50Ω;
FIG. 4 is a graph of electrical waveforms produced by the circuit of FIG. 1 over a period of time with a patient load of 100Ω;
FIG. 5 is a graph of electrical waveforms produced by the circuit of FIG. 1 over a period of time with a patient load of 150Ω;
FIG. 6 is a graph of electrical waveforms produced by the circuit of FIG. 1 over a period of time with a patient load of 200Ω;
FIGS. 7A-F illustrate various current profiles and phase profiles that may be used with the circuit of FIG. 1 to deliver a variety of different defibrillating waveforms to the body of a patient;
FIG. 8 is a schematic drawing of a drive circuit for switches used in an H-bridge sub-circuit of the circuit of FIG. 1 ;
FIG. 9 is a graph of electrical waveforms produced by the circuit of FIG. 1 with a patient load of 25Ω, when programmed for pacer mode; and
FIG. 10 is a graph of electrical waveforms produced by the circuit of FIG. 1 with a patient load of 300Ω, when programmed for pacer mode.
DETAILED DESCRIPTION
This invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
As noted in the BACKGROUND section, defibrillators are devices that deliver a desired quantity of energy to a patient without exceeding a safe power level. Energy is simply power delivered to a load over a period of time:
Pt = E ; or P = E t ;
where P represents power in Watts, E represents energy in Joules, and t represents the period of time in seconds over which the energy is delivered. When electrical energy is dissipated in a simple resistive load, that is, one which resists a flow of electrical current when a voltage is applied, power may be expressed in terms of the voltage applied to the load, voltage being a measure of electrical pressure across the load, and current through the load, current being a measure of movement of charge through the load. Electrical power is:
P = VI ; or P = I 2 R ; or P = V 2 R ;
where V represents voltage in Volts, I represents current in Amperes, and R represents the resistance of the load in Ohms.
Defibrillators store the desired quantity of electrical energy on a capacitor, as a charge. Storing a charge on a capacitor causes a voltage to appear across the terminals of the capacitor. When a user of a defibrillator applies a therapeutic shock to a patient, the electrical energy stored on the capacitor is released through the patient, whose body provides substantially a simple resistive load in which the energy is dissipated. As the capacitor supplies energy to the load, the charge on the capacitor decreases, and so the voltage appearing across the capacitor also decreases. As voltage decreases, or sags, the current driven through the load also decreases. Applying any of the definitions of electrical power given above, it is observed that the power, P 0 , delivered by the capacitor at the beginning of a therapeutic shock of a defined magnitude, E 0 , is greater than the power, P N , delivered by the capacitor at the end of the therapeutic shock because the voltage on the capacitor sags as the charge on the capacitor is depleted by supplying current to the patient.
Conventionally, in order to accommodate the voltage sag, while delivering a constant, desired maximum power level until the desired energy impulse has been delivered, the size of the capacitor is selected to provide the desired energy impulse to a worst-case load at the end of the energy impulse. For these purposes, a worst-case load may be considered to be one at a lower end of an expected resistance range, since such a load will require a larger current to maintain a constant power level during the energy impulse. Such a design requires a capacitor that, when charged to a level that yields the desired energy impulse, dissipates in the patient a power level in excess of that desired during the initial portion of the energy impulse. As previously explained, during times of excess power delivery, the excess energy is simply dissipated into resistors so as to reduce to desired maximum levels the power delivered to the load, i.e., the patient, which both wastes power and necessitates the use of a capacitor whose rated energy storage capacity is greater than the maximum energy delivery requirement, since energy is dumped into the dissipation resistors and not recovered or otherwise put to therapeutic use.
Using a capacitor whose rated energy storage capacity is greater than the maximum energy delivery requirement is disadvantageous from several perspectives. For a given capacitor technology, greater storage capacity requires greater size and/or weight. A physically larger capacitor is undesirable, particularly for use in portable equipment, because equipment must be built larger and is more difficult to transport. Size and weight factors can prove prohibitive for equipment meant to be worn by, transported with, or carried by, a patient who themselves may not be fully ambulatory. Moreover, energy that is wasted, yet must be stored on the capacitor as described above, adds to the charging time and the performance characteristics required of the charging circuit which places the energy on the capacitor.
For example, in the conventional defibrillator described in the BACKGROUND section in which excess energy is dissipated into dissipation resistors, a capacitor having a minimum required energy rating of approximately 381 Joules is used. Under favorable conditions for maximum energy shock (i.e., a 200 Joule setting into a patient presenting an impedance of 161Ω), approximately 69% of the capacitor's minimum required energy rating is delivered to the patient. For higher impedance patients, energy utilization drops off slightly to 67% for a patient presenting an impedance of 175Ω, and to 63% for a patient presenting an impedance of 200Ω. The drop off in energy utilization is more severe for lower impedance patients (e.g., 37% for a patient presenting a 25Ω impedance, and 21% for a patient presenting a 15Ω impedance), primarily due to energy dissipated in the dissipation resistors. One of the physically smallest capacitors validated for use in such a conventional defibrillator weighs approximately 10 oz (283.5 grams) and has a volume of approximately 20 in 3 (327.7 cm 3 ).
According to aspects of embodiments, a boost converter is employed to control and regulate the delivery of a constant current, resulting in a constant power dissipation level during the delivery of a desired energy impulse. In brief summary, a boost converter transfers energy in very short bursts compared to the time for delivering the total desired energy impulse, first from the capacitor to an inductor, which stores the energy as a substantially constant current, and then from the inductor to the patient. Because the current delivered to the patient by the inductor is substantially constant due to the intrinsic electrical characteristics of inductors which tend to resist a change to current through them, a constant, maximum desired power level is dissipated in the patient, in accordance with the definitions of electrical power given above. A boost converter circuit of a defibrillator incorporating aspects of embodiments is now described in greater detail.
First, the basic boost converter circuit is described in connection with FIG. 1 . The boost converter circuit, 100 , provides a substantially constant current at its output node, 101 , when that node is connected to a load, 102 . The circuit, 100 , includes a storage capacitor, 103 , in which the energy for the desired impulse is held until a discharge into the patient load is triggered; an inductor, 104 , connected to receive a current from the storage capacitor, 103 , when the discharge is triggered; a diode, 105 , to protect against a reversal of the current discharge; and, optionally a smoothing capacitor, 106 ; as well as control elements enumerated below. A charge circuit, such as a battery or other DC power source (not shown) is coupled to the storage capacitor 103 , for example via relays, to provide energy to the storage capacitor 103 . A terminal of the storage capacitor 103 is electrically coupled to a first terminal of the inductor 104 , which in FIG. 1 is modeled as an inductor 1041 coupled in series with a resistor 104 r . The second terminal of the inductor 104 is electrically coupled to the anode of the diode 105 , with the cathode of the diode 105 being electrically coupled to a first terminal of the optional smoothing capacitor 106 and to the output node 101 .
According to the capacitor energy equation, E=½CV 2 , an exemplary capacitor, 103 , of 270 μF, as shown in FIG. 1 , charged to about 1218 V would store 200 Joules for the exemplary therapeutic shock. To deliver 200 Joules over a 10 msec impulse requires delivering a substantially constant, instantaneous power of 20 kW to the load, 102 . If the load, 102 , is 25Ω, then the power equation, P=I 2 R, calls for a current of 28 A, while a load, 102 , of 200Ω calls for a current of 10 A. Inductor, 104 , is of a size to prevent substantial current droop while delivering a desired power level to the patient load, 102 . A 1 mH inductor, 104 , as shown in FIG. 1 , produces the desired result, as illustrated below in FIGS. 2-6 . In accordance with one embodiment, the inductor 104 may be an unsaturable 1 mH Litz wire air-core coil dimensioned to optimize self inductance.
While 100% utilization of the capacitor energy storage capability is the theoretical goal, practical circuit elements, which have real losses associated with them, achieve somewhat lower utilization rates, per the Table I, below. The simulations presented in FIGS. 2-6 , and discussed below, assume capacitor, 103 , has a capacitance of 270 μF, and an initial stored energy of 305 Joules.
TABLE I
Patient
Therapeutic Shock
10 msec Continuous
Initial Energy
Impedance
Energy
Power
Usage
25 Ω
249 Joules
24.9 kW
81%
50 Ω
255 Joules
25.5 kW
83%
100 Ω
236 Joules
23.6 kW
77%
150 Ω
221 Joules
22.1 kW
72%
200 Ω
210 Joules
21.0 kW
69%
By comparison to a conventional defibrillator using a storage capacitor having a minimum energy rating of 381 Joules, embodiments of the present invention permit the use of a storage capacitor having an approximately 20% lower minimum energy rating (e.g., 305 Joules) while providing a similar amount of energy to the patient. As a result, the size and weight of the storage capacitor 103 used with embodiments of the present invention may be reduced by approximately 20% relative to storage capacitors used in a conventional defibrillator. Further efficiencies of size and cost are provided by eliminating the need for dissipation resistors and their associated shunting devices used in conventional defibrillators, as well as any of the thermal management features needed to dissipate the heat generated therefrom.
A specialized controller circuit, 107 , modeled for convenience as a UC3842 current mode PWM controller, has a control output connected to a control input of a high-voltage and high-current, solid-state switch, 108 that is coupled between the second terminal of the inductor 104 and a current sensing network 109 . The solid state switch 108 may be an IGBT as shown in FIG. 1 , or another type of a high-voltage and high current solid state switch, such as a thyristor. It should be appreciated that embodiments of the present invention are not limited to the use of a particular type of PWM controller or to a particular type of high-current solid state switch, as other types of controller circuits, and other types of high-current switches may alternatively be used. Current drawn through the switch 108 is measured by the current sensing network, 109 ; compared to a desired current profile, 110 ; and, the result is provided as an input to the controller circuit, 107 . Since, as explained above, current is directly related by a square law to instantaneous power, controlling for a desired current also controls for the desired instantaneous power level.
The load presented by the patient, 102 , is connected to the output node, 101 , through an H-bridge structure which causes current to flow through the patient in a desired direction at a desired time. The H-bridge includes four H-bridge switches 111 , with each H-bridge switch 111 a , 111 b , 111 c , 111 d including a respective switching transistor 116 a , 116 b , 116 c , 116 d and a respective control circuit 117 a , 117 b , 117 c , 117 d associated with each. The switching transistors can be insulated-gate bipolar transistors (IGBTs), metal-oxide semiconductor field-effect transistors (MOSFETs), silicon-controlled rectifiers (SCRs) or such other high-current switching devices as may be available. In the exemplary, illustrative embodiment, for modeling purposes only, an oscilloscope, 112 , having a channel A input, 112 A, and a channel B input, 112 B, has been included. Channel A, 112 A, monitors the current impulses passed through the switch, 108 , and channel B, 112 B, monitors the voltage across the patient load, 102 . The traces produced by channels A and B, 112 A and 112 B, are shown in FIG. 2 , which is next referred to in an explanation of the operation of the circuit of FIG. 1 .
The circuit of FIG. 1 operates as follows to provide a 200-Joule defibrillation shock to a patient load, 102 , of 25Ω, as illustrated in FIG. 2 . The storage capacitor, 103 , is first charged up with about 200 Joules of electrical energy, by a charging circuit (not shown). There are small, parasitic losses due to parasitic resistances throughout the circuits which deliver the charge to the patient, including parasitic resistances in the inductor, 104 r , and elsewhere. If the parasitic resistances are negligible, then no more than about 200 Joules need be stored on the capacitor; however, if the parasitic resistances are non-negligible, then the storage capacitor, 103 , should hold a small excess above the desired 200 Joules of electrical energy, the excess being sufficient to just account for the energy dissipated in the parasitic resistances under worst-case conditions. It should be appreciated that other shock energies (i.e., other than 200 Joules) may be provided, as known to those skilled in the art.
According to one embodiment, operation begins with the solid-state switch, 108 , open, and each of the H-bridge switches, 111 a - d , open. When a therapeutic shock is triggered, a pair of the H-bridge switches, e.g., 111 a and 111 c , is closed, initiating current through the patient load 102 . Current then builds up in the inductor, 104 . As shown in FIG. 2 , indicated by line, 200 , current through switch, 108 , is zero during this initial period, 201 . Next, during period, 202 , the controller circuit, 107 , begins cycling switch, 108 , on and off, thereby allowing current through switch, 108 . When the switch, 108 , is closed and the controller circuit, 107 , detects that the desired current or higher is flowing through the switch, 108 , it provides a control signal to the solid-state switch, 108 , to again open the switch, 108 , allowing current through the inductor, 104 , to the patient load, 102 . At regular intervals, the controller, 107 , closes the switch, 108 , and checks for the current to build up to the desired level, at which point the control signal again opens the switch, 108 .
During each cycle, during period, 202 , when the controller circuit, 107 , determines from the output of the current sensing network, 109 , that the correct current level has been reached or exceeded, a control signal is applied to the solid-state switch, 108 , to open the switch, allowing current through the inductor, 104 , and the patient load, 102 , from the energy stored on storage capacitor, 103 . As current is initiated through the patient, a voltage, indicated in FIG. 2 by line 210 , appears across the patient that causes the current in the inductor, 104 , to begin to decay, and so the controller circuit, 107 , again closes solid-state switch, 108 , to begin the cycle again by building up the current stored in the inductor. By repeating the forgoing cycle many times during the therapeutic shock, energy stored on the storage capacitor, 103 , is metered out to the patient without ever exceeding the maximum allowable power dissipation level in the patient. According to some embodiments, it has been found that the desired waveform to be applied to the patient reverses polarity after an interval. Accordingly, the H-bridge switches are controlled by a desired phase profile, 120 , to open the closed pair of switches, 111 a and 111 c , and close the open pair of switches, 111 b and 111 d , at about 6 msec into the therapeutic shock cycle, reversing the polarity of the applied shock, 211 . It should be noted that switches 111 a and 111 c are opened prior to closing switches 111 b and 111 d to avoid short-circuiting the H-bridge structure. The magnitude of the current applied to the patient load, 102 , (and the resulting voltage across the patient load, 102 ) does not substantially change during the polarity reversal, 211 and 213 .
As shown in FIGS. 3 , 4 , 5 , and 6 , the operation is similar for patients presenting resistance values of 50Ω, 100Ω, 150Ω, and 200Ω. The variation in the load, 102 , results in different damping characteristics for the therapeutic shock waveforms, i.e., the overall shape of the waveform, and also results in different patient voltages, such that the 200 Joule impulse is applied as desired. In each of FIGS. 3 , 4 , 5 , and 6 , reference numerals indicating corresponding elements to elements of FIG. 2 correspond, except for the hundreds place, which corresponds to the FIG. number. For example, FIG. 2 , line 200 , corresponds to FIG. 3 , line 300 , but for a different patient load, 102 .
As shown in FIG. 2 , for a patient load, 102 , of 25Ω, the absolute value of patient voltage 210 varies between a peak of about 1.5 kV and 500 V. For a patient load, 102 , of 50Ω, the absolute value of patient voltage 310 has a much flatter shape, as shown in FIG. 3 . It hits a peak of about 2 kV but remains for most of the impulse at about 1.2 kV, finally tapering down to just under 1.0 kV. As shown in FIG. 4 , for a patient load, 102 , of 100Ω, the absolute value of patient voltage 410 has an even flatter shape. It also hits a peak of about 2 kV but remains for most of the impulse at about 1.5 kV, finally tapering down to about 1.2 kV. For a patient load, 102 , of 150Ω, the absolute value of patient voltage 510 has a quite flat shape, as shown in FIG. 5 . It hits a peak of about 2 kV but remains for nearly the entire impulse at about 1.8 kV. For a patient load, 102 , of 200Ω, the absolute value of patient voltage 610 has a quite flat shape. It hits a peak of about 2 kV but remains for nearly the entire impulse at about 1.8 kV, as shown in FIG. 6 .
In practical systems, the preference is to deliver substantially constant energy to the patient during a period of time. Thus, if a 200 Joule therapeutic shock is desired to be delivered in a 10 msec period, the controller circuit, 107 , is designed or programmed to obtain a current level in the inductor, 104 , that delivers 20 J/msec. The controller circuit, 107 , in connection with the current sensing network, 109 , the desired current profile, 110 , and the solid state switch, 108 , forms a feedback loop that controls and maintains the 20 J/msec level, or such other level or waveform as desired. Except for parasitic losses, explained below, the storage capacitor, 103 , need only have a rated energy storage capacity of 200 Joules, since no excess energy is dumped and it is desired to leave no residual energy in the storage capacitor, 103 , after the therapeutic shock has completed.
FIGS. 7A-F illustrate the manner in which the boost converter circuit 100 of FIG. 1 may be used to control the shape and/or phase of the defibrillating waveform applied to the patient. As described previously with respect to FIG. 1 , current drawn through the switch 108 is measured by the current sensing network 109 , compared to a desired current profile 110 , and provided as an input to the controller circuit 107 . In the circuit illustrated in FIG. 1 , this comparison is performed by an operational amplifier 118 configured as a comparator. By controlling the shape and amplitude of the desired current profile 110 , a waveform of a desired amplitude and desired shape may be delivered to the patient load 102 .
For example, as shown in FIG. 7A , a current profile 110 having a step impulse that corresponds to a current level of approximately 22 A and that gradually increases to a level corresponding to approximately 40 A may be used to provide the current and voltage waveforms depicted in FIGS. 3-6 . The current profile 110 is approximately 10 msec in duration and includes an initial period or region 110 a where the current is zero (corresponding to periods 301 , 401 , 501 , and 601 in FIGS. 3-6 ), followed by a step impulse (region 110 b ) corresponding to approximately 22 A. At approximately 1 msec, the current profile 110 linearly increases (region 110 c ) to a value corresponding to approximately 24 A. The current profile 110 remains at a level corresponding to about 24 A for about 2 msec (region 110 d ), where it then linearly increases (region 110 e ) to a level corresponding to approximately 40 A, after which the current profile returns to a zero current level (region 110 f ) at approximately 10 msec. The overall shape of the current profile 110 used to generate the current and voltage waveforms depicted in FIGS. 3-6 is shown in each respective figure by the respective envelope or profile 303 , 403 , 503 , and 603 of the current through the switch 108 . Differences in the voltage waveforms 310 , 410 , 510 , and 610 applied to the patient in FIGS. 3-6 are primarily due to differences in the patient load 102 . The overall shape of the current profile 110 used to generate the current and voltage waveforms depicted in FIG. 2 is shown in FIG. 2 by the envelope 203 of the current 200 through the switch 108 .
The phase of the defibrillating waveform that is applied to the patient may be controlled by the desired phase profile 120 provided to each of the H-bridge switches 111 . For example, FIG. 7B illustrates a desired phase profile 120 that may be used to control the phase of the waveforms depicted in FIGS. 2-6 . As shown, the phase profile 120 initially assumes a high state at time zero (or before) followed by a change to a low state at 6 msec. In the circuit depicted in FIG. 1 , each of H-bridge switches 111 a and 111 c receives the phase profile 120 , while each of H-bridge switches 111 b and 111 d receives an inverted version of the phase profile 120 . The high state of the phase profile 120 operates to fully close each of H-bridge switches 111 a and 111 c during the initial 6 msec, and to maintain each of switches 111 b and 111 d in a fully open position. At approximately 6 msec, the level of the phase profile 120 changes, thereby fully opening H-bridge switches 111 a and 111 c , and fully closing switches 111 b and 111 d , thereby reversing the polarity of the delivered voltage waveform as shown in each of FIGS. 2-6 . The presence of the inverter 115 serves to not only invert the phase profile 120 , but to delay the signal provided to each of H-bridge switches 111 b and 111 d to help ensure that these switches are not closed until after switches 111 a and 111 c have opened. If necessary, additional delays could be provided. Where the switching transistors 116 a , 116 b , 116 c , and 116 d used in each of the H-bridge switches 111 a , 111 b , 111 c , 111 d are capable of operating in a linear mode, the high state and the low state of the phase profile 120 should be such that the switching transistors are either fully conducting (on) or fully non-conducting (off) to avoid thermal destruction.
FIG. 7C illustrates an alternative desired current profile 110 that may be used with the boost converter circuit 100 of FIG. 1 to generate a biphasic voltage waveform that increases asymptotically from a zero value to a desired voltage level (e.g., to approximately 2 kV in amplitude for a 200Ω patient) over the initial portion of each phase. When combined with a phase profile 110 similar to that illustrated in FIG. 7B , the boost converter circuit 100 may provide a defibrillating voltage 710 to the body of the patient similar to that shown in FIG. 7D . As shown in FIG. 7D , the biphasic voltage waveform 710 is approximately 10 msec in duration and switches phase at approximately 6 msec. During the first few milliseconds of each phase, the voltage 710 applied to the body of the patient rises asymptotically to an amplitude of about 2000 V (for a 200Ω patient). To achieve the shape of the voltage waveform 710 shown in FIG. 7D , the smoothing capacitor 106 ( FIG. 1 ) may be omitted or set to a value of zero. Such a ramped asymptotic voltage waveform as shown in FIG. 7D may reduce the amount of trauma to the patient's heart during defibrillation, by avoiding the step impulse in voltage shown in each of FIG. 2-6 .
FIGS. 7E and 7F illustrate alternative phase profiles that may be used with the current profile 110 discussed above with respect to FIG. 7A . For example, FIG. 7E illustrates a desired phase profile 120 having two opposing phases over a 10 msec duration, in which the opposing phases are substantially similar in duration (i.e., about 5 msec each). Such a phase profile may be used to balance the amount of charge delivered to the patient's heart in each direction and thereby potentially reduce the trauma to the patient's heart. FIG. 7F illustrates yet an alternative phase profile that may be used to provide a monophasic defibrillating shock to the body of the patient.
It should be appreciated that a variety of different current profiles 110 and phase profiles 120 may be used with the boost converter circuit 100 of FIG. 1 to generate a corresponding variety of different defibrillating waveforms, each having a different shape and/or amplitude and/or phase. For example, the current profile 110 could include a simple exponential waveform or a damped sine wave, and the phase profile 120 could be monophasic, biphasic, triphasic, or otherwise. Accordingly, where it is determined that a particular shape, amplitude, phase, sequence of phases, or all of the above is particularly effective, reference waveforms may be generated and used as desired current profile 110 and desired phase profile 120 to achieve the desired resultant defibrillating waveform. Although not depicted in FIG. 1 , each of the desired current profile 110 and the desired phase profile 120 may be stored in a memory, and provided, for example, by a processor of the defibrillator to comparator 118 and each of H-bridge switches 111 to vary the shape, amplitude, or phase of the defibrillating waveform applied to the patient as desired.
Referring back to FIG. 1 , again, within each H-bridge switch, 111 a - d , is a driver circuit (i.e., 117 a , 117 b , 117 c , and 117 d ). These circuits are feedback systems illustrated in greater detail in FIG. 8 . Each driver circuit is configured to control a switching transistor (i.e., 116 a , 116 b , 116 c , and 116 d , respectively) to pass a current up to a controlled maximum level above which the current is clipped.
In each driver circuit is an operational amplifier, 802 , connected to receive a control signal, DRIVE, that is based upon the desired phase profile 120 and produce an output, GATE, which turns a switching transistor ( FIG. 1 , 116 a , 116 b , 116 c , and 116 d ) on and off as required. A second operational amplifier, 804 , is connected to sense current through each switching transistor ( FIG. 1 , 116 a , 116 b , 116 c , and 116 d ), and control an input to operational amplifier, 802 , so a voltage at output, GATE, turns the switching transistor on up to a desired maximum current through the switching transistor. In the embodiment depicted in FIG. 1 , each of the switching transistors 116 a , 116 b , 116 c , and 116 d is an IGBT that may be operated in a non-linear mode as a two state (i.e., on or off) switch, or in a linear mode as a voltage controlled current source. Where the circuit 100 is used to provide therapeutically effective amounts of energy sufficient for defibrillation, the switching transistors 116 a , 116 b , 116 c , and 116 d would typically be operated in the non-linear mode (e.g., as a two state switch) to avoid thermal destruction. However, by adjusting the timing defined by controller circuit, 107 , the desired current profile, 110 , and the desired phase profile, 120 , the circuit of FIG. 1 can be programmed to perform pacing, as well as defibrillation. For example, by appropriately controlling the timing defined by the controller circuit 107 and the desired current profile 110 , and at energies typically used for pacing, the smoothing capacitor 106 can substantially correspond to a DC power supply of a desired voltage. By then providing a suitable phase profile to pairs of H-bridge switches (i.e., 111 a and 111 c , 111 b and 111 d ), the switching transistors of a respective pair of H-bridge switches may be operated in their linear mode to provide a desired pacing waveform.
FIGS. 9 and 10 illustrate a phase profile 120 that may be provided to pairs of H-bridge switches, 111 a and 111 c or 111 b and 111 d , to deliver suitable pacing waveforms 902 , 1002 , to a patient load 102 , when the timing defined by the controller circuit 107 and the current profile 110 have been appropriately programmed In each of FIGS. 9 and 10 , the timing of the controller circuit 107 and the current profile 110 have been programmed so that smoothing capacitor 106 effectively operates as a 50 V D.C. voltage source. As illustrated in FIG. 9 , a voltage level of approximately 27 mV provided to the DRIVE input of driver circuits 117 A and 117 C is sufficient to deliver an 8 mA, 200 mV pacing pulse into a patient 102 presenting a 25Ω load. As illustrated in FIG. 10 , a voltage level of approximately 465 mV is sufficient to deliver an 140 mA, 42 V pacing pulse into a patient 102 presenting a 300Ω load. By appropriately controlling the phase profile 120 , pacing pulses ranging from a few milliamps to two hundred milliamps or more may be provided to a patient, using the same circuit topology as that used to deliver a defibrillating shock.
It should be appreciated that although embodiments of the present invention have been primarily described with respect to defibrillation and pacing, they may also be used to deliver other types of therapeutic waveforms to the body of a patient in which the energy delivered is between the ranges of energy typically used for pacing or defibrillation. For example, pacing pulses typically range from a few mA to approximately 200 mA, and defibrillation pulses typically range from about 1 A to about 35-40 A. Between these ranges of current exists a wide spectrum of energies that may be applied to the body of a patient for a variety of therapeutic purposes, for example, to perform charge bumping of a patient's heart, etc. Accordingly, by varying the timing of the controller circuit, the current profile 110 , and the phase profile 120 , embodiments of the present invention may be used to tailor one or more of the shape, the voltage, and the current of a therapeutic waveform to be applied to the body of a patient.
Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.
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A system and method to deliver a therapeutic quantity of energy to a patient. The system includes a capacitor having a rated energy storage capacity substantially equal to the therapeutic quantity of energy, a boost converter coupled with the capacitor and constructed to release energy from the capacitor at a substantially constant current for a time interval, and an H-bridge circuit coupled with the boost converter and constructed to apply the substantially constant current in a biphasic voltage waveform to the patient. The method includes storing a quantity of energy substantially equal to the therapeutic quantity of energy in a capacitor, releasing the quantity of energy at a relatively constant current during a time interval using a boost converter coupled with the capacitor, and delivering a portion of the quantity energy in a direction to the patient using an H-bridge circuit coupled with the boost converter.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to methods and apparatus of sewing and stitching. More specifically, this invention relates to a lock stitch, wherein a novel “hook and loop” style lower thread is interlocked with a conventional upper thread.
2. Description of the Prior Art
Until now, the two-thread lock stitch has been among the most widely used methods of joining fabric. Conventionally, and as shown in FIGS. 1 and 2, a two-thread lock stitch 32 P includes two threads: a needle or upper thread 24 , and a bobbin or lower thread 50 P. The upper thread is typically wound on a spool system (not shown) to provide a continuous feed of thread. In contrast, the lower thread 50 P is typically wound on a bobbin 54 P to provide a predetermined feed of thread. The two-thread lock stitch 32 P is considered an efficient stitch that does not unravel easily and has a “both-sides equal” aesthetic appearance. In order to maintain the aesthetic appearance, the upper and lower threads 24 and 50 P must typically be composed of nearly identical size and strength material to enable stitch conformance.
Stitch conformance relates to the relative position of the upper and lower threads 24 and 50 P in the stitch as shown in FIGS. 1 and 2. Conventional lock stitch practice requires a balance of stitching force on either side of a workpiece 10 P being sewn, so that the lower thread 50 P is not completely pulled up through the workpiece 10 P. FIGS. 1 and 2 illustrate how the upper thread 24 and lower thread 50 P must properly entwine at a midpoint 16 P of the workpiece 10 P.
Referring to FIG. 1, in operation, a needle 20 penetrates the workpiece 10 P from a front side 12 P thereof, carrying with it the upper thread 24 that is fed through an eyelet 22 of the needle 20 . The needle 20 reaches the bottom of its stroke on a back side 14 P of the workpiece 10 P and starts to retract, thus forming a loop 26 from the slack upper thread 24 . Referring now to FIGS. 1 and 2, and as is well known in the art, the bobbin 54 P and the entire supply of lower thread 50 P is encircled by the loop 26 in order to interlock the upper and lower threads 24 and 50 P, thus forming the locking portion of the lock stitch 32 P. The size of the bobbin 54 P and quantity of lower thread 50 P is necessarily relatively small to enable them to be encircled by the loop 26 . Therefore, the bobbin 54 P is exhausted of its lower thread 50 P at extremely frequent intervals, resulting in downtime of the sewing operation, and, often, stopping and restarting of the sewing operation in the middle of the workpiece 10 P.
Several alternative methods and associated devices of the prior art have been directed at mitigating the problem of the limited supply of lower thread. For example, U.S. Pat. No. 4,117,789 to Rovin et al. teaches a method of automatically loading a bobbin in situ. Rovin et al. disclose a highly complex apparatus that is capable of reloading an empty bobbin in between workpiece cycles and as an operator positions a new workpiece to the sewing machine. The apparatus refills the empty bobbin, in situ, with a precisely measured length of thread.
U.S. Pat. No. 4,140,069 to Laursen teaches a sewing method and associated apparatus for forming a double backstitch seam. The double backstitch seam is formed similarly to previous versions of two-thread lock stitches with one exception. The upper thread is fed through the workpiece and a loop thereof is formed as usual. The lower thread, however, is processed much differently than those of the prior art. The supply of lower thread is not passed entirely through the loop as usual, but instead is passed through the loop in individual thread sections equal in length to several stitches. The lower thread is fed from a relatively large continuous spool, similar to the upper thread. As the loop is formed, a free end of the lower thread is fed and sucked through the loop by a suction nozzle. As the loop is tightened by the needle retracting back through the workpiece, a looper simultaneously grabs the lower thread section near its middle and a free end of a previous lower thread section. The looper then pulls back and tightens the lower thread sections against the loop, thus completing a lock stitch.
Finally, U.S. Pat. No. 4,366,765 to Hoekstra teaches use of a combination single thread chain and lock stitch. Hoekstra discloses a stitch formation having a first loop passing through the workpiece thus forming the first half of a chain stitch. A second loop passes through the workpiece and, with the first loop, forms the second half of the chain stitch. A locking thread passes through the closed end of the second loop to form a lock stitch. The chain and lock stitches thus formed are continuously alternated for the entire length of the stitch.
In addition to the problem of a limited supply of lower thread, thread breakage is a frequent problem when generating the conventional lock stitch. If either the upper or lower thread breaks during a stitch cycle, the entire process must be stopped and the sewing machine re-threaded. Additionally, the article being sewn must be scrapped, or the stitch removed and restarted, since the stitch cannot be stopped and restarted in mid-stitch.
Therefore, what is needed is a lock stitch, method, and related apparatus that is inexpensive, efficient, does not require a bobbin having a limited supply of lower thread, that uses a method and apparatus that are relatively simple compared to the prior art, and that is not so susceptible or sensitive to thread breakage.
SUMMARY OF THE INVENTION
According to the present invention there is provided a novel lock stitch that does not require use of a bobbin nor other complex thread feeding mechanisms, thereby avoiding the shortcomings of the prior art—particularly that of thread breakage and a limited supply of lower thread.
In one form of the invention, an article is provided in the form of a workpiece having a novel lock stitch. Preferably, the stitched article includes the workpiece having upper and lower layers or plies, and a series of needle-made stitch holes extending from a front side through to a back side thereof. A stitch is provided through each stitch hole, and includes an upper thread and a lower thread. The upper thread extends down through each stitch hole, forms a loop underneath the workpiece, and extends back up through each stitch hole. The lower thread is composed of discrete cut-off segments of a hook material, having hooks therein, wherein the lower thread interlocks with the upper thread, and extends transversely through the loop and is entrapped between the loop and the back side surface of the workpiece.
Alternatively, the lower thread can take the form of a hook material composed of discrete cut-off segments that are each aligned with a respective stitch hole. The upper thread extends down through the workpiece and the hook material. The upper thread forms a loop underneath the workpiece and the loop is interlocked with the hooks. Optionally, the workpiece can include the back side surface that is composed of a loop material having loops therein for interlocking with the hooks of the lower thread. Further still, the stitched article can also include an underlining applied to the back side of the workpiece and over the lower thread. The underlining can be composed of a loop material having loops therein interlocking with the hooks of the hook material of the lower thread to retain the underlining to the workpiece.
An apparatus is provided for producing the lock stitch of the present invention wherein the apparatus includes a needle, with an eyelet therethrough, for penetrating the workpiece to a back side thereof. A loop spreader mechanism is provided on the back side of the workpiece for spreading a loop of the upper thread, as is well known in the art. A feeder mechanism and conduit is provided for feeding a portion of the lower thread through the loop of the upper thread, wherein a portion of the lower thread is entrapped between the loop and the back side of the workpiece to complete the lock stitch.
An assembly method is provided for using the apparatus of the present invention to make the stitched article of the present invention. The method includes penetrating a workpiece with a needle that carries an upper thread therethrough, wherein a loop of the upper thread is formed on a back side of the workpiece. Next, the loop of the upper thread is enlarged by a loop spreader and a portion of a lower thread is fed through the loop of the upper thread. The lower thread is fed in a direction transverse to the travel of the upper thread, and the lower thread is composed of a hook material having hooks therein. Finally, the needle is retracted back through the workpiece and thus the upper thread is pulled back through the workpiece, the loop is pulled tightly against the lower thread and the lower thread is in turn pulled against a back side surface of the workpiece. During the retracting step, the upper thread interlocks with the hooks of the lower thread to securely lock the stitch in place.
Accordingly, it is an object of the present invention to reduce overall process time by eliminating the need to use a bobbin of limited lower thread supply. The present invention provides an unlimited length of lower thread such that interrupting the sewing cycle to resupply the bobbin is unnecessary. Stitch cycle time is also reduced, since the upper thread need not make the long travel around the bobbin.
It is another object to provide improved locking action between an upper and lower thread of a lock stitch via interlocking action between hook and loop material used for the lower thread and back side of the workpiece.
It is yet another object to provide a simplified machine and method for producing a lock stitch.
It is a further object of the present invention to reduce or eliminate the instances of thread breakage, as is prevalent in the prior art.
These objects and other features, aspects, and advantages of this invention will be more apparent after a reading of the following detailed description, taken in conjunction with the appended claims and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a seam being sewn according to a two-thread lock stitch of the prior art, wherein a lower thread wound on a bobbin is being passed through a loop in an upper thread to produce the lock stitch;
FIG. 2 is a perspective view of the seam of FIG. 1, wherein the upper thread is being pulled upwards to tighten against the lower thread to complete the lock stitch;
FIG. 3 is a partially cutaway perspective view of a seam being sewn into a workpiece according to one embodiment of the present invention;
FIG. 3A is a perspective view of three examples of a lower thread composed of hook material;
FIG. 3B is the workpiece of FIG. 3, further illustrating an underlining being applied underneath;
FIG. 4 is a partially cutaway perspective view of the stitching apparatus used for carrying out the method of the present invention;
FIG. 5 is a partially cutaway perspective view of the stitching apparatus of FIG. 4 illustrating a loop spreading step;
FIG. 6 is a partially cutaway perspective view of the stitching apparatus of FIG. 5, wherein a lower thread in the form of a strip is being fed through a loop in an upper thread;
FIG. 7 is a partially cutaway perspective view of the stitching apparatus of FIG. 6, wherein the loop of the upper thread is being pulled against the lower thread to complete the lock stitch;
FIG. 8A is a partial bottom perspective view of a seam being sewn according to another embodiment of the present invention;
FIG. 8B is a partial sectional view of an alternative workpiece and hook material of FIG. 8A;
FIG. 8C is a partial sectional view of another alternative workpiece and hook material of FIG. 8A;
FIG. 8D is a partial sectional view of yet another alternative workpiece and hook material of FIG. 8A;
FIG. 9 is a partially cutaway perspective view of the seam of FIG. 8A, wherein a loop of an upper thread is being flattened against a bottom thread hook material;
FIG. 10 is a perspective view of an alternative lower thread conduit and loop spreader device initially engaging the upper thread;
FIG. 11 is a top view of the device of FIG. 10 illustrating a quill fully inserted into the loop of the upper thread;
FIG. 12 is an end view of the device of FIG. 10 showing the loop of the upper thread initially engaged; and
FIG. 13 is an end view of the device of FIG. 11 showing the loop of the upper thread fully enlarged.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 3 through 7 illustrate partially cutaway sectional views in order to more clearly show the stitching operation. Additionally, the term back side may mean, in general, the area underneath the workpiece as the workpiece is being sewn. Back side may also refer specifically to the actual surface on the back side of the workpiece. This characterization applies analogously to the term front side.
Referring now in detail to the Figures and specifically to FIG. 3, there is shown an article or workpiece 10 undergoing a process of stitching according to an embodiment of the present invention. The workpiece 10 is shown as a combination of upper and lower plies 18 U and 18 L of material that are penetrable by a needle 20 from a top or front side 12 of the workpiece 10 . On a bottom or back side 14 of the workpiece 10 , a loop sheet 19 is preferably included in the form of an additional layer, but may instead take the form of individual patches or strips. As such, the loop sheet 19 establishes a back side surface 14 S of the workpiece 10 . The loop sheet 19 is consistent with hook and loop fastener material otherwise known under the trademark of VELCRO®. Thus, the loop sheet 19 includes a pattern of loops 19 L therein. Alternatively, the loop sheet 19 may be formed of loop material composed of DACRON® polyester scrim or mesh, or have an integral loop laminate. For example, automobile interior material, such as simulated leather, typically includes a woven backing layer that could be replaced by a woven or non-woven material having loop characteristics.
An upper thread 24 is shown along a seam 30 having four lock stitches 32 completed within four stitch holes 34 in the workpiece 10 . The upper thread 24 is preferably composed of any standard strand-like thread, but may also be composed of any other material including, for example, a monofilament line for limited applications, or a loosely stranded wire. The upper thread 24 includes a loop 26 that is formed underneath the workpiece 10 after the needle 20 penetrates the upper and lower plies 18 U and 18 L, and the loop sheet 19 . A lower thread 50 is caused to move inside the loop 26 such that when the needle 20 is withdrawn from the workpiece 10 the lower thread 50 resides between the loop 26 of the upper thread 24 and the back side 14 of the workpiece 10 , as the upper thread 24 is pulled upwards to tighten the loop 26 , thus establishing the lock stitch 32 . The lower thread 50 is preferably composed of material consistent with hook and loop fastener material, and, thus, includes a pattern of hooks 52 therein.
Moreover, upon retraction of the needle 20 from the workpiece 10 , the loop 26 of the upper thread 24 does not only encircle the lower thread 50 , but forces engagement of the hooks 52 to the loops 19 L on the loop sheet 19 to further secure the lock stitch. The hooks 52 of the lower thread 50 interlock with the loops of the loop sheet 19 underneath the workpiece 10 to secure the lock stitch. Those skilled in the art will recognize that the lower thread 50 preferably includes a cross-sectional area greater than the cross-sectional area of the stitch hole 34 , thereby preventing the lower thread 50 from being pulled through the stitch hole 34 by the upper thread 24 . The lower thread 50 is preferably formed as shown in FIG. 3 of discrete cut-off segments, cut from a continuous strip fed along the back side 14 of the workpiece 10 . As shown in FIG. 3A, the lower thread 50 preferably takes the form of a cylindrical shape 50 C. Alternatively, a laminate 50 A, or a folded laminate 50 B, could be used.
FIG. 3B illustrates an alternative application of the present invention with an underlining 70 . The underlining 70 is shown as being secured to a side of the lower thread 50 that is opposite the side that interlocks with the loop sheet 19 . The underlining 70 is also composed of a loop type material having loops 72 therein for interlocking with the hooks 52 of the lower thread 50 . Such an underlining 70 is preferably an individual sheet or patch of material, but may also take the form of a component attached to a larger assembly such as a seat (not shown). Accordingly, the hooks 52 of the lower thread 50 of the workpiece 10 can be quickly and easily interlocked to corresponding VELCRO® loops of a seat, a headliner, a dashboard, etc.
FIG. 4 illustrates the portion of a sewing apparatus 80 that is preferably used to produce the stitched article of FIG. 3 . Note that the direction of travel of the workpiece 10 in FIGS. 4 through 7 is exactly opposite that of FIG. 3, in order to more clearly show the loop 26 and lower thread 50 interaction. Located preferably underneath the workpiece 10 , is a base 82 that supports an upright loop spreader 84 and conduit 86 . The loop spreader 84 is moveably mounted with respect to the base 82 and includes a finger 88 as is consistent with such prior art devices. The conduit 86 is preferably fixed to the base 82 , or alternatively can be moveable with respect to the base 82 . A loop guard 90 extends parallel to but offset from the needle 20 and a blade 92 extends in the same direction as the needle 20 and abuts an exit end 86 E of the conduit 86 .
In operation, the needle 20 reciprocates down and up and carries in its eyelet 22 the upper thread 24 into and out of the workpiece 10 along the seam. As shown in FIG. 4, the needle 20 is carrying the upper thread 24 to the back side 14 of the workpiece 10 and has reached the bottom of its stroke. As the needle 20 begins its return, or upward stroke, the upper thread 24 becomes slack, thereby widening the loop 26 , as is well known in the art. The loop guard 90 is aligned closely to one side of the needle 20 in order to push the slack in the upper thread 24 to the opposite side of the needle 20 for enlarging the loop 26 , as is consistent with the prior art. Simultaneously, the loop spreader 84 begins to move toward the needle 20 as shown by arrow 84 A from its home position as shown in FIG. 4 .
The lower thread 50 is continuously fed through the conduit 86 in a direction transverse—preferably normal—to the direction of travel of the upper thread 24 . The lower thread 50 can be fed in any convenient method, but is preferably fed in a similar manner to that which is well known in the prior art and best exemplified by U.S. Pat. No. 4,920,904 to Frye, which is incorporated by reference herein. The blade 92 , in its up position as shown, temporarily blocks the lower thread 50 from advancing toward the loop 26 .
As shown in FIG. 5, the loop spreader 84 advances toward the needle 20 to its fully advanced position so that the finger 88 enters the loop 26 . The blade 92 remains in its up position and the loop spreader 84 begins to move sideways as shown by arrow 84 B. As shown in FIG. 6, the loop spreader 84 sweeps sideways to its fully open position away from the needle 20 in order to further enlarge the loop 26 . Simultaneously, the blade 92 drops away from the conduit 86 as shown by arrow 92 A to permit the lower thread 50 to feed forward through the enlarged loop 26 and stop against the loop spreader 84 . Accordingly, a portion of the lower thread 50 is fed through the loop 26 . As shown in FIG. 7, the blade 92 returns upward to its home position as shown by arrow 92 B to sever the lower thread 50 into a discrete segment 50 S of predetermined length. The needle 20 proceeds upward as shown by arrow 20 A, thereby pulling and entrapping the discrete segment 50 S of lower thread 50 in the loop 26 and forcing it against the back side 14 of the workpiece 10 . Alternatively, and not shown, the conduit 86 advances through the loop 26 with the lower thread 50 housed therein to an advanced position. The conduit 86 would then retract back out of the loop 26 while the lower thread 50 maintains the advanced position within the loop 26 . In this way, the conduit 86 would further ensure a proper feed of the lower thread 50 through the loop 26 .
As shown in FIGS. 8A and 9, an alternative article and method of sewing is presented. In FIG. 8A, a workpiece 110 includes upper and lower plies 118 U and 118 L, and a lower thread or hook material 150 establishing a back side surface 114 thereof. The hook material 150 preferably takes the form of a strip as shown, but can also take the form of patches or an entire sheet layer. The hook material 150 is preferably loosely applied to the back side of the workpiece 110 , but may be permanently attached thereto. As shown in FIG. 8A, the needle 20 carries the upper thread 24 down and up through the workpiece 110 . As discussed above, the loop 26 is formed along the back side surface 114 of the workpiece 110 , as is well known in the art.
In contrast with the previous embodiment, however, only a hook portion 152 of the lower thread 150 is fed into engagement or interlocks with the loop 26 . Here, the loop 26 is flattened against a portion of the hooks 152 of the hook material such that the loop 26 is spread out along the back side surface 114 amongst the hooks 152 for interlocking the upper thread 24 to the hooks 152 of the back side surface 114 of the workpiece 110 . Accordingly, the loop 26 of the upper thread 24 is maintained and secured by the hooks 152 along the back side surface 114 of the workpiece 110 and will not pull through the stitch hole (not shown).
FIGS. 8B and 8C respectively show standard hooks 152 B for use with a stranded upper thread 24 , and shanked cones 152 C for use with a monofilament thread (not shown). FIG. 8D illustrates a dual locking combination of standard hooks 152 B and shanked cones 152 C that are particularly suited for use with stranded types of thread. With this dual locking arrangement, the shanked cones 152 C provide a positive transverse lock and maintain position of the upper thread 24 until the loop 26 is forced into engagement with the hooks 152 B along the back side surface 114 of the workpiece 110 . Additionally, the stranded upper thread 24 may be slightly unraveled so as to be more receptive to being interlocked with the standard hooks 152 B and shanked cones 152 C of the lower thread. Accordingly, the standard hooks 152 B and shanked cones 152 C are sufficiently rigid and sharp in order to interlock with strands of the stranded upper thread 24 .
FIG. 9 illustrates one approach for flattening the standard loop 26 of the workpiece 110 of FIGS. 8A through 8C. FIG. 9 illustrates the workpiece 110 as a partial cutaway to better show the loop 26 . A hammer tool 95 is advanced upward into engagement with the loop 26 and perpendicular to the back side surface 114 of the workpiece 110 , so that the loop 26 flattens against the back side surface 114 of the workpiece 110 . The loop 26 thus engages the hooks (not shown) of the back side surface 114 to retain the loop 26 from pulling back through the workpiece 110 . A back side surface 114 combination of hooks 152 B and shanked cones 152 C, as shown in FIG. 8D, effects a situation where the upper thread (not shown) cleats around the shanked cones 152 C thereby being securely positioned and then locked in that position by the hooks 152 B. The hammer tool 95 is preferably advanced by a pneumatic cylinder located below the loop guard 90 and loop spreader apparatus (shown in FIG. 4 ). The hammer tool 95 also preferably includes a head 95 H composed of a resilient and conformable material such as rubber. Additionally, the head 95 H may have a predetermined surface configuration, such as one with projections, in order to more effectively force the loop 26 into interlocking engagement with the hooks.
FIGS. 10 through 13 illustrate a portion of the preferred embodiment of the apparatus of the present invention. As shown in FIG. 10, a quill 184 replaces the stationary conduit 86 of FIGS. 4 through 7. The quill 184 includes a hollow housing 186 and a hollow spreader 188 that is slidingly disposed within the hollow housing 186 . A spear portion 188 S pointedly terminates a hollow body portion 188 B of the spreader 188 .
As shown in FIGS. 10 and 12, the spreader 188 and lower thread 50 advance from a home position within the housing 186 toward the needle 20 . In this way, the spear portion 188 S begins to run through the loop 26 of the upper thread 24 in an initial engagement position as shown. Beyond this initial engagement position, the spreader 188 and lower thread 50 continue to advance through the loop 26 until they reach an advanced position.
The advanced position is set by a stopper 189 , that locates on the end of the lower thread 50 to prevent it from advancing any further, as shown in FIG. 11 . As best shown in FIGS. 11 and 13, as the spreader has advanced transversely through the loop 26 , the loop 26 has gradually enlarged as it transitions from, or ramps over, the spear portion 188 S to the body portion 188 B of the spreader 188 . Accordingly, the loop 26 directly circumscribes the body portion 188 B that, in turn, circumscribes the lower thread 50 . As a result, the lower thread 50 is now circumscribed by the loop 26 in the advanced position.
From this advanced position, the spreader 188 fully retracts back into the housing 186 to the home position, while the lower thread 50 remains in the advanced position circumscribed by the loop 26 . Finally, at or near the same time the needle 20 and upper thread 24 are retracted back upward, the blade 92 advances upward to sever the lower thread 50 and complete the stitch cycle.
From the above, it can be appreciated that a significant advantage of the present invention is that the sewing process need not be interrupted to supply more lower thread to a bobbin, either due to thread breakage or limited thread supply. In fact, the present invention provides for continuity of lower thread supply, where the sewing cycle need not be interrupted to add additional lower thread.
An additional advantage is that the thread locking action is improved because the pull-up force of the upper thread causes the hooks of the lower thread to penetrate, entwine, encircle, interlock, and otherwise mesh with the upper thread strands and the back side loop material. Accordingly, the stitched seam will have a higher than traditional shear strength and will be more resistant to being ripped apart.
Another advantage is that the size of the upper thread can be varied without affecting the conformance of the stitch. Stitch conformance is therefore guaranteed since regardless of the upper thread pull-up force, the lower thread cannot be pulled up through the workpiece. Therefore, any tension adjustment of the upper thread is much less sensitive and easier to control than with current lock stitches.
Yet another advantage is that thread damage will not migrate beyond the stitch that is damaged. Each discrete segment of lower thread locked with the upper thread against the hooks on the back side surface ensures that damage to the continuous upper thread will not migrate beyond the adjacent damaged stitch. This is because of the inherently high shear and locking strength associated with hook and loop joining. Similarly, threading can be terminated without the need for multiple end stitches to prevent unraveling of the seam.
Still another advantage is that the stitches will be more moisture resistant since each discrete segment of lower thread effectively blocks off the stitch hole on one side. Hooks on the lower thread interlocking with loops on the back side surface of the workpiece even further ensure moisture resistance.
A further advantage is that the hooks of the lower thread provide an attachment base for any underlining material having loops therein, such that the workpiece has inherent fastening capability. Accordingly the workpiece can be removably secured to another object having such an underlining material. Alternatively, an independent underlining material can be removably secured to the lower threads of the workpiece until it can be permanently secured thereto, similar to a basting thread attachment.
Still a further advantage is that the stitch of the present invention is not as susceptible to thread wear as stitches of the prior art. Interlocked stranded threads of the prior art tend to failure prematurely due to rubbing action between relatively small surface areas on the threads. This is particularly true for stitches in seat cushions that typically bear heavy dynamic loads. With the present invention, the surface area between the threads is much larger since the lower thread is much larger than lower thread of the prior art. Accordingly, the stitch is more capable of distributing load per unit area between the threads, and therefore more robust against failure due to thread wear.
Yet a further advantage is that the length of the lower thread segments can be varied in order to increase strength and rigidity of the workpiece.
While the present invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. For example the location of the hooks and loops could be reversed, such that the lower thread has loops and the back side of the workpiece has hooks. Accordingly, the scope of the present invention is to be limited only by the following claims.
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An article, method, and related apparatus for a novel hook and loop lock stitch. The lock stitch is embodied in a stitched article that includes a workpiece including a series of stitch holes, or a seam, therethrough and further including a back side surface composed of a hook material including hooks therein. The lock stitch is provided through each stitch hole, and includes an upper thread extending down through each stitch hole, forming a loop underneath the workpiece, and extending back up through each stitch hole. A lower thread, or strip, is composed of a hook material including hooks therein. The loop is spread out amongst the hooks of the lower thread and interlocks therewith. The lower thread is thus entrapped between and within the loop and the back side surface of the workpiece. The workpiece can include the back side surface being composed of a loop material including loops therein for interlocking with the hooks of the lower thread. The stitched article can also include an underlining applied to the back side of the workpiece and over the lower thread. The underlining can be composed of a loop material including loops therein interlocking with the hooks of the hook material of the lower thread to retain the underlining to the workpiece.
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CROSS-REFERENCE TO RELATED APPLICATION
More than one reissue application has been filed for the reissue of U.S. Pat. No. 6,199,914. The reissue applications are Reissue application Ser. No. 10/325,047 filed on Dec. 20, 2002 (the present application) and Reissue application Ser. No. 11/581,229, filed on Oct. 12, 2006 which is a Divisional of Reissue application Ser. No. 10/325,047.
This application claims priority and is based on Provisional Application 60/088,586 filed on Jun. 9, 1998.
BACKGROUND OF THE INVENTION
This invention relates to quick connect assemblies including quick connector fittings which quickly and releasably connect to a well casing for providing an interface for attaching well related equipment such as blowout preventors to the casing.
Fittings, such as drilling flanges, are currently used to provide an interface to well casings for mounting various equipment such as blowout preventors. A conventional fitting, such as a drilling flange, is threaded onto the casing until a shoulder within the drilling flange makes contact with the casing mouth. An elastomeric O-ring seals the drilling flange/casing interface. Once such a drilling flange is mounted on a casing, it is difficult to remove. Consequently, in many instances, the drilling flange remains permanently on the casing. As a result, on the field where multiple drilling operations may be going on at once, a separate drilling flange is required for each casing. This can be expensive.
Another problem with these flanges is that their orientation with respect to the casing cannot be accurately predetermined. The orientation depends on how tight the flange is threaded on the casing. This shortcoming poses a problem in situations where the equipment to be attached requires a specific orientation relative to the casing.
As such, a quick connect assembly is needed which provides for the easy installation and removal of a quick connector fitting so as to allow the fitting to be used on multiple casings in the field and which allows the fitting to be oriented to any desired position relative to the casing.
SUMMARY OF THE INVENTION
The present invention is directed to quick connect assemblies allowing for the quick and releasable connection of a quick connector fitting to a well casing for providing an interface for the attachment of well related drilling equipment such as blowout preventors. In a first embodiment, a male receiver is coupled to the casing. The receiver has an annular lip formed on its outer surface near its upper open end or mouth. The annular lip has a lower surface which slopes upward in a radially outward direction. A quick connector fitting has a first cylindrical section which tapers to a smaller second cylindrical section. A flange extends radially from an upper end of the smaller cylindrical section. The flange provides the interface for attaching well related equipment. The larger cylindrical section of the fitting is slid over the mouth of the male receivers. Threaded openings are formed radially through the larger section of the fitting and are arranged circumferentially around the fitting. Lock screws are threaded through the openings to engage the lower sloping surface of the annular lip male receiver. As the lock screws are tightened, the lip sloping surface guides them downward thereby causing the fitting to seat and lock on the male receiver mouth. To remove the fitting, the lock screws are loosened.
In another embodiment, a quick connector fitting is used having an annular lip formed on its inner surface. A flange extends from an upper end of the fitting to provide the interface for attachment of the various well related equipment. The fitting lower end is slid over the casing head such that a lower surface of the annular lip is seated on the mouth of the casing. An annular groove is formed circumferentially around the outer surface of the fitting near the fitting lower end. The annular groove has a lower surface that slopes downward in a radially outward direction. A retainer slip, preferably a four piece retainer slip, having an upper and a lower annular lip is used to secure the fitting to the casing. The upper lip engages the groove, while the lower lip engages the outer surface of the casing. Teeth are formed on the face of the lower retainer slip lip that engages the casing. A clamp surrounds the retainer slip. As the clamp is tightened, it provides radial forces on the retainer slip causing the teeth formed on the lower lip to engage the casing outer surface and thus fix the position of the retainer slip relative to the casing. As the clamp is further tightened, the retainer slip upper lip engages the lower sloping surface of the groove formed on the outer surface of the fitting and causes the fitting to move downward against the casing. As a result, the annular lip formed on the inner surface of the fitting sits tightly against the casing mouth.
In yet a further embodiment, an annular bushing is threaded on the outer threads formed on the casing. Preferably the bushing is threaded downward about ¼ inch±⅛ inch from the casing mouth. An annular groove is formed on the outer surface of the bushing. The groove has an upper surface which slopes upward in a radially outward direction. A fitting is then fitted over the casing and the bushing. The fitting has an inner shoulder which sits on the mouth of the casing. On its opposite end, the fitting forms a flange for providing an interface for the well related equipment. Fasteners are threaded radially through the fitting to engage the upper surface annular groove. The sloping upper surface guides the fasteners downward thereby causing the fitting to tightly seat on the mouth of the casing and to lock on the bushing and thereby on the casing. Lock nuts may be threaded on the fasteners from the ends opposite the ends engaging the groove on the bushing. These lock nuts are threaded until they engage the outer surface of the fitting providing a radially outward force on the fasteners preventing them from loosening from the fitting.
In another embodiment an annular casing head is coupled to the casing. The casing head can be threaded directly to the casing or may be coupled to the casing using a coupling. An annular groove is formed on the outer surface of the casing head. The annular groove has an annular upper surface and an annular base.
A quick connector fitting is mated to the casing head. The quick connector fitting has a flange that extends from an upper end of the fitting for providing an interface for connecting well related equipment.
An annular drilling flange nut is threaded on the lower outer surface of the quick connector fitting. Load key bolts are fitted through radial openings formed on the flange nut. A retainer is used to retain each bolt on the flange nut. A preferable arc-shaped load key located inside the flange nut is threadedly engaged by each load key bolt. As a load key bolt is turned it causes its corresponding load key to translate radially and into the groove formed on the outer surface of the casing head. The flange nut is then further torqued causing the load keys to contact and apply a force against the upper surface of the annular groove on the casing head. As result, a downward force is applied by the flange nut on the quick connector fitting causing the quick connector to further sit on the mouth of the casing head forming a tight connection.
With any of the above described embodiments, a wear bushing ray be fitted such that it provides a protecting lining to the inner surface of the casing head and a portion of the quick connector inner surface extending above the casing head. Moreover, with all of these embodiments, the quick connector fittings are preferably fastened to a groove. As a result, the fittings can be oriented to any position over the casing mouth prior to being quickly and releasably connected to the casing.
DESCRIPTION OF THE DRAWINGS
FIG. 1A is an exploded cross-sectional view of a quick connector assembly including a male receiver coupled to a well casing and a quick connector fitting.
FIG. 1B is a cross-sectional view of the assembled quick connector assembly shown in FIG. 1A .
FIG. 2A is a partial cross-sectional view of an alternate embodiment quick connector.
FIG. 2B is a partial cross-sectional view of the quick connector shown in FIG. 2A prior to the tightening of a slip retainer clamp.
FIG. 2C is a partial cross-sectional view of the quick connector shown in FIG. 2A with the quick connector body welded to the casing.
FIG. 3 is a cross-sectional view of an alternate embodiment quick connector assembly incorporating a bushing.
FIG. 4A is an exploded cross-sectional view of an alternate embodiment quick connector assembly prior to the mounting of the quick connector fitting on to the casing head.
FIG. 4B is an enlarged cross-sectional view of the coupling member of the assembly shown in FIG. 4A coupling the casing head to the casing.
FIG. 4C is an enlarged cross-sectional view of the drilling flange nut of the assembly shown in FIG. 4A .
FIG. 4D is another cross-sectional view of the drilling flange nut shown in FIG. 4C .
FIG. 4E is a cross-sectional view of the assembled quick connector assembly shown in FIG. 4A .
FIG. 4F is an enlarged cross-sectional view of the drilling flange nut of the assembly shown in FIG. 4E .
FIG. 5A is an exploded cross-sectional view of another embodiment quick connector assembly.
FIG. 5B is a partial enlarged cross-sectional view of the casing head of the assembly shown in FIG. 5A threaded to a casing.
FIG. 5C is a cross-sectional view of another embodiment quick connector fitting assembly.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to quick connect assemblies which include a quick connector fitting (also referred to herein as a “quick connector”) that can be mounted quickly on a well casing providing an interface for the mounting of well related equipment such as blow out preventors (“BOP”). The quick connector fittings may be used and re-used on many different casings.
In a first embodiment, the quick connect assembly comprises a quick connector fitting 10 and a male receiver 12 . The quick connector fitting 10 releasably connects to the male receiver 12 which is coupled to a well casing 14 ( FIGS. 1A and 1B ). The casings typically have a diameter of 13-⅜ inches. The male receiver is typically connected to the casing using a coupling 16 . The coupling is an internally threaded cylindrical member. One end of the coupling is threaded to the external casing threads. The male receiver is then torqued to inner threads on the coupling other end.
The male receiver is typically a tubular member. The male receiver as a first end or mouth 18 for connecting with the quick connector fitting and a second end 20 for threading on the coupling. Two parallel annular lip protrusions are formed on the outer surface of the male receiver near it first end ( FIGS. 1A and 1B ). The first or upper lip 22 is formed around the mouth of the male receiver. The upper lip has an upper surface 19 that slopes downward in a radially outward direction. The upper lip also has a lower surface 23 that slopes upward in a radially outward direction. The second or lower lip 24 is formed below and spaced apart from the upper lip. An annular groove 26 is formed between the two lips.
The coupling 16 is threaded to the casing 14 . The male receiver is then torqued to the coupling. The male receiver may be torqued to the coupling using conventional tools such as tongs (not shown). Once the male receiver is torqued in place, the quick connector is fitted over the male receiver. The quick connector has a first larger cylindrical section 50 which tapers via a tapered section 52 to a second smaller cylindrical section 54 ( FIG. 1A ). A flange 56 is formed around the mouth of the second section to allow for the connection of a BOP or other well related equipment. The BOP or other well related equipment may be connected to the flange prior to installation of the quick connector to the male receiver.
The larger cylindrical section of the quick connector is placed over the male receiver such that its tapered section contacts and mates with the sloping upper surface 19 of the upper lip 22 at the mouth of the male receiver. At least two internally threaded holes 58 are formed circumferentially on the larger cylindrical section of the quick connector. When in position over the male receiver, the holes 58 are aligned with an upper portion of the groove 26 formed between the lips on the male receiver ( FIG. 1B ). Lock down screws 60 are then threaded through the holes and engage the lower sloping surface 23 of the upper lip. As the lock down screws are threaded farther, they ride on the sloping lower surface of the upper lip pulling the quick connector tighter against the mouth of the male receiver.
Preferably, two annular grooves 28 are formed on the inner surface of the first cylindrical section above the threaded holes 58 . A pressure or mechanically energized seal 30 is fitted in each groove. A single groove fitted with a single seal may suffice. When the quick connector is mounted an the male receiver, the seals 30 also contact the outer surface of the upper lip of the male receiver. As such, the seals form a seal against the upper lip as well as against the inner surface of the first cylindrical section of the quick connector fitting. Alternatively, the grooves 28 may be formed on the outer surface of the upper lip of the male receiver instead of the quick connector first section inner surface. The seals 30 are then seated on the grooves such that when the fitting is positioned over the male receiver, the seals will again seal against the inner surface of the first section of the quick connector and against the upper lip of the male receiver. Alternatively, the groove(s) and seal(s) may be positioned so that the seal(s) seal against the male receiver lower lip and the inner surface of the first cylindrical section of the quick connector. In a further embodiment, a seal or multiple seals may be used to form a seal against the inner surface of the quick connector and the male receiver upper lip while a second seal or second set of seals may be used to form a seal between the quick connector and the male receiver lower lip.
In an alternate embodiment, a quick connector fitting 62 is used that fits directly over the outer casing 14 ( FIG. 2A ). This quick connector consists of a cylindrical body 64 . An inner annular lip 66 is formed on the inner surface of the cylindrical body. An outer annular flange 68 is formed on the upper end of the cylindrical body. The upper flange serves as the connection interface with the BOP or other well related equipment. An annular groove 72 is formed on the outer surface of the cylindrical body near the body lower end ( FIG. 2B ). In cross-section, the groove has an upper surface 74 , a base 76 parallel to the longitudinal axis of the body and a lower surface 78 that slopes downward in a radially outward direction.
One, but preferably two, spaced apart annular grooves 80 are formed on the inner surface of the body below the inner annular lip ( FIG. 2A ). These grooves are designed to accommodate pressure or mechanically energized seals (not shown). In an alternate embodiment, an injection fitting 82 and a pressure relief fitting 84 are fitted in the wall of the body such that they extend from the outer surface of the body to an inner groove. The injection fitting and the pressure relief fitting should be spaced preferably 180° apart. An injection and a pressure relief fitting may be incorporated for each of the inner grooves.
The quick connector is slid over the outer surface of the casing 14 until the lower face 70 of the inner lip 66 rests against the mouth 86 of the casing. In the embodiment where the inner annular grooves 80 are fitted with seals, the seals must be fitted in the grooves prior to the installation of the quick connector over the casing.
A retainer slip 88 is fitted over the quick connect. The retainer slip is preferably in four pieces, each forming a 90 degree arc. However, a two or more piece retainer slip may also be used. The retainer slip consists of a lower annular lip 90 extending radially inward. Teeth 92 are formed on the inner surface of the lower annular lip. The retainer slip also has an upper inwardly extending annular lip 94 that has a shape complementary to the shape of the groove 72 formed on the outer surface of the quick connector body. As such, the lower surface 96 of the retainer slip upper lip slopes downwardly in a radially outward direction such that it is complementary to the bottom sloped surface 78 of the annular external groove formed on the quick connector body.
A slip retainer clamp 98 is clamped around the retainer slip so as to hold all the retainer slip pieces in place. As is apparent to one skilled in the art, it may be preferable to place the retainer slip and clamp over the casing prior to the placement of the quick connector body over the casing. In this regard, when the body is fitted over the casing, the slip may be easily moved over the quick connector body and clamped into place.
Initially, the clamp is tightened just enough to hold the retainer slip pieces in place as shown in FIG. 2B . When this occurs the tip portion 100 of the retainer slip upper lip is in contact with the lower sloped surface 78 of the groove formed on the body outer surface. As the clamp is further tightened, the teeth 92 formed on the inner surface of the lower lip of the retainer slip bite onto the outer surface of the casing 14 fixing the relative position between the casing and the retainer slip. As the clamp is further tightened, it causes the lower sloped surface 96 of the upper lip of the slip to attempt to travel up the lower sloped surface 78 of the external groove. As a result, the retainer slip, which is now fixed relative to the casing, causes the quick connector body to move downward and therefore the body inner lip lower surface 70 to tightly engage the mouth 86 of the casing.
If the body has injection and pressure relief fittings, a sealing material 81 may be injected into the annular grooves through the injection fittings 82 until it is relieved through the pressure relief fittings 84 to form a seal between the casing and the connector.
A production or inner casing 102 is always fitted within the casing 14 (i.e., the outer casing) forming an annulus 104 therebetween ( FIG. 2C ). In many situations, after drilling is completed, a predetermined amount of cement is pumped down the production casing until it exits the lower end production casing and comes around filling and sealing the annulus.
For proper sealing, the Department of Oil and Gas (“DOG”) requires that the annulus is completely filled with cement. As such, enough cement must be pumped to fill the annulus. If more cement than required to fill the annulus is pumped, the cement will stay within the bottom of the production casing creating a blockage. As such, operators are inclined to be conservative in the amount of cement pumped into the production casing. As a result, sometimes the amount of cement pumped may be insufficient and does not fill the annulus completely. In these situations, the DOG permits the use of an automatic casing hanger 106 —or with a pack-off hanger (not shown) or with a mandrel casing hanger (not shown)—fitted within the quick connector as a supplement for sealing the annulus. Automatic casing hangers, pack-off hangers and mandrel casing hangers are well known in the art. When a hanger is used for sealing, the quick connector becomes a permanent fixture of the casing and thus, cannot be used with another casing. For economic purposes, however, it is recommended that the retainer clamp 98 and retainer slip 88 are removed so that they can be re-used. In their stead, the lower edge 108 of the quick connector body is welded to the outer casing.
In a further embodiment, an annular bushing 110 is threaded hand tight on the outer threads 111 formed on the outer surface of the casing head 112 ( FIG. 3 ). The casing head is coupled to the open end of a casing (not shown), preferably by threading. The outer bushing is preferably threaded down a distance 116 of about ¼ inch±⅛ inch from the casing head mouth 120 . A circumferential groove 129 is formed on the outer surface of the bushing. The groove has an upper surface 146 that slopes upward in a radially outward direction. A quick connect fitting 124 is fitted over the bushing and the casing head.
The quick connector fitting has an upper and a lower section. The lower section defined by an annular lip wall 128 which defines a first opening with a diameter slightly larger than the hushing outer surface diameter. At least two internally threaded holes 126 are defined circumferential through the wall 128 . A second opening 132 is defined in the upper section of the fitting. The second opening concentric to and in communication with the first opening and has a diameter preferably equal to the inner diameter of the mouth of the casing head. A flange 134 is formed at the mouth 136 of the upper section for mating with a BOP or other well related equipment. An internal annular shoulder 138 is formed at the interface between the upper and lower sections of the flange member. An annular groove 140 is formed on the shoulder to accommodate a pressure or mechanically energized seal 141 .
The fitting is fitted over the bushing and rotated to a desired position. When the flange is fitted over the casing head, the seal sits on the mouth 127 of the casing head. When the fitting is seated on the casing head mouth, the threaded hole 126 centers will be located at a level aligned with an upper portion of the bushing circumferential groove. Lock down screws 142 having a threaded head 145 are then threaded through the threaded holes. The lock down screw heads have a tip portion 144 that is frusto-conical in shape having a frusto-conical surface 143 . As the lock down screws are threaded into the holes their tip portions first engage the sloping upper surface 146 of the bushing groove. As they are further threaded on the fitting they ride against the groove upper sloping surface pulling the quick connector fitting further downward and creating a tight seal between the fitting shoulder, the seal, and the mouth of the casing head. Consequently, the fitting is locked on the bushing and thereby on the casing head. Because the fitting locks against a groove (i.e., the bushing groove 146 ), the fitting can be rotated and locked at any desired position.
In a further embodiment, the lock down screws 142 have a section 150 of their shaft threaded. This threaded shaft section is spaced apart from the threaded head section of the screws which engage the threaded holes 126 . A lock nut 152 is threaded on the threaded section 150 formed on the shaft of each screw after the screws have locked the fitting on the bushing. The lock nut 152 has a central threaded bore section 154 which extends into a non-threaded bore section 156 . The non-threaded bore section has a diameter larger than the threaded bore section. As the nut is screwed on the threaded shaft, its unthreaded bore section contacts the fitting annular wall 128 outer surface. As it is further screwed, it exerts a radial outward force on the screw which is threaded on the fitting wall, thereby locking the screw in place. A retainer ring 158 may then be fitted on the screw behind the nut to prevent the nut from getting lost if it were to loosen. The screw with lock nut can be preassembled with the retainer ring in place.
In another embodiment an annular casing head 212 is coupled to the casing 214 using an annular coupling member 216 ( FIG. 4A ). Typically the casing head has a first annular portion 218 which tapers into a second annular portion 220 via a truncated cone shaped annular third portion 222 . The first portion has an inner diameter greater than the inner diameter of the second portion. The second portion has threads 224 formed on its outer surface at its and furthest from the first portion. The inner surface of the third portion defines a shoulder 226 that slopes upward in a radially outward direction.
The coupling member 216 is a cylindrical member having inner threads. Preferably two sets of threads are formed beginning on the inner surface of the coupling member, one set at either end. The first set of threads 228 are matched to the outer threads 224 formed on the second portion of the casing head ( FIG. 4B ). The second set of threads 230 are matched to the outer threads 232 on the casing. The coupling through its second set of threads is threaded on the outer threads of the casing. The casing head is then threaded onto the first set of the coupling threads.
An annular groove 234 is formed on the outer surface of the first portion of the casing head near the intersection of the first portion with the truncated cone shaped portion. The annular groove has an annular upper surface 236 and an annular base 238 .
A quick connector fitting 240 is then mated to the casing head. The quick connector fitting has a first section 242 which extends into a second section 244 forming an inner annular shoulder 246 at interface between the first and second section inner surfaces. In other words, the fitting first section has an inner diameter is larger than the inner diameter of the second section. The length of the first section as measured from the annular shoulder should be slightly less then the length 250 measured from the mouth of the casing head to the upper surface of the annular groove. A flange extends from the end of the second section opposite the first section providing an interface for connecting well related equipment.
Preferably two annular grooves 254 are formed on the inner surface of the first section, preferably on the upper thicker wall portion of the section. A flange seal 256 , which is typically an O-ring seal, is fitted into each groove. An annular wall 252 defines the fitting first section. The annular wall 252 is thinner at the open or lower end of the first section. However, the inner diameter of the first section in constant throughout the length of the section. Threads 260 are formed on the outer surface of the lower thinner portion 258 of the fitting first section.
An annular drilling flange nut 262 has an annular upper section 264 , an annular intermediate section 266 and an annular lower section 268 ( FIGS. 4A and 4C ). The inner surface diameter of the upper section is smaller than the inner surface diameter of the intermediate section and greater than the inner surface diameter of the lower section. The inner surface diameter of the lower section should preferably be at least slightly larger than the outer surface diameter of the casing head first section 218 . The three sections form an annular channel 272 . Threads 270 are formed on inner surface of the upper annular section matched to the threads 260 on the outer surface of the lower portion 258 of the fitting first section.
The outer surface of the drilling flange nut 242 preferably has an octagonal shape providing grip 274 areas for torquing on to the fitting using a wrench or a hammer ( FIG. 4D ). Radial openings 276 are formed equidistantly through the nut outer surface penetrating the nut intermediate section and exiting on the annular channel 272 formed on the inner surface of the flange nut. The openings are formed to accommodate load key bolts 278 . Each load key bolt is rotatably connected to a retainer 280 . The retainer is perpendicular to the load key bolt. Each load key bolt can rotate relative to, but cannot longitudinal translate through, its corresponding retainer. The load key bolts are fitted through the radial opening 276 on the flange nut and the retainer 280 is bolted on the outer surface of the flange nut using retainer bolts 282 .
A tip portion 286 of each load key bolt shaft extending radially beyond its corresponding radial opening 276 is threaded. Each load key bolt is able to freely rotate relative to its corresponding opening 276 formed on the flange nut. An arc shaped load key 288 is threaded to each threaded shaft portion 286 . In a preferred embodiment, eight load keys are used, one for each load key bolt. Each load key is an eighth of a ring section. The load key bolt is threaded to a threaded opening 290 formed on the center section of the load key causing the load keys to translate radially outward and rest against the annular channel 272 formed on the flange nut.
The inner surface diameter of the quick connector first section 242 is slightly greater than the outer surface diameter of the casing head first portion 218 . The quick connector is slid over the casing head until the annular shoulder 246 sits on the mouth 292 of the casing head ( FIG. 4E ). When at this position, the lowest end 243 of the fitting first section 242 extends almost to the upper surface 236 of the annular groove formed on the outer surface of the casing head. The fitting is rotated in relation to the casing head to a desired orientation.
The flange nut is then threaded to the outer threads 260 formed on the first section of the fitting. The flange nut may also be pre-threaded on the first section of the fitting prior to mounting the fitting over the casing head. When the flange nut is threaded on the fitting, the load keys are sandwiched between the lower portion 288 of the flange nut 262 and the lower end 243 of the fitting first section.
The flange nut is threaded sufficiently for aligning the load keys with the groove 234 formed on the outer surface of the casing head. Each load key bolt is then rotated causing its respective load key to unthread from the load key bolt and travel radially inward into the groove 234 formed on the casing head ( FIG. 4D ). The load keys bolts are rotated until the load keys stop against the base 238 of the casing head groove without exerting a force on the groove. When in that position, preferably, all the load keys abut each other forming a continuous ring.
The flange nut is then further torqued on the lower portion of the fitting first section causing the load keys to contact and apply a force against the upper surface 236 of the annular groove 234 on the casing head ( FIG. 4F ). As result, a downward force is applied by the flange nut on the quick connector first section causing the quick connector to further sit on the mouth 292 of the casing head forming a tight connection.
In an alternate embodiment, a casing head 312 is directly threaded on to the casing 314 ( FIGS. 5A and 5C ). With this embodiment, the casing head has a first portion 318 . A second portion 320 extends below from the first portion. Threads 394 are formed in the lower inner surface of the second portion. These threads are matched to threads 328 formed on the outer surface of the casing head allowing for the torquing of the casing head to the casing ( FIG. 5B ). An annular lip 396 is formed on the inner surface of the second portion. The annular lip formes an upper shoulder 395 that slopes upward in a radially outward portion direction. In addition, the annular lip forms a lower annular shoulder 326 . The quick connector fitting 340 mates with the casing head as described above in relation to the previous embodiment. The quick connector fitting also has a first section 342 which extends into a second section 344 forming an inner annular shoulder 346 at the interface between the first and second section inner surfaces.
With any of the above described embodiments, a wear bushing 400 ( FIGS. 4E and 5C ) may be fitted such that it lines the inner surface of the casing head first portion 218 , 318 and a portion of the quick connector inner surface extending above the casing head first portion. When in position, typically, the bottom edge 401 of the wear bushing which is sloped mates with and rests against the sloping shoulder 226 , 326 formed on inner surface of the casing head. Preferably, a threaded hole 298 , 398 is formed radially through the second section 244 , 324 of the quick connector fitting near the fitting inner shoulder 246 , 346 . When the wear bushing is properly seated, the threaded hole provides access to an outer surface of the bushing. A lock screw 299 , 399 is threaded through the threaded hole for engaging and locking the wear bushing in place.
With any of the aforementioned embodiments, the BOP 8 ( FIGS. 4A , 4 E, 5 A, 5 C) or other well related equipment is connected, typically by fasteners, to the fitting. In this regard, the BOP or other well related equipment can be easily connected to or disconnected from the well casing.
Although the present invention has been described and illustrated to respect to multiple embodiments thereof, it is to be understood that it is not to be so limited, since changes and modifications may be made therein which are within the full intended scope of this invention as hereinafter claimed.
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A quick connector fitting assembly is provided which includes a fitting which releasably connects to a well casing for providing an interface for the attachment of various types of well related equipment. The quick connector fitting connects using fasteners to a lip or groove formed on the casing. The fasteners can easily connect or disconnect from the groove or lip facilitating the quick connection and disconnection of the fitting from the casing.
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[0001] The present application is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/267,457 filed Nov. 7, 2008, currently pending, which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 10/461,451 filed Jun. 16, 2003, now U.S. Pat. No. 7,533,548 B2, which claims priority to Korean Patent Application No. 85521/2002, filed Dec. 27, 2002, the entire contents of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a drum type washing machine, and more particularly, to a drum type washing machine which can maximize a capacity of a drum without changing an entire size of a washing machine.
[0004] 2. Description of the Related Art
[0005] FIG. 1 is a side sectional view showing a drum type washing machine in accordance with the conventional art, FIG. 2 is a front sectional view showing the drum type washing machine in accordance with the conventional art.
[0006] The conventional drum type washing machine comprises: a cabinet 102 for forming an appearance; a tub 104 arranged in the cabinet 102 for storing washing water; a drum 106 rotatably arranged in the tub 104 for washing and dehydrating laundry; and a driving motor 110 positioned at a rear side of the tub 104 and connected to the drum 106 by a driving shaft 108 thus for rotating the drum 106 .
[0007] An inlet 112 for inputting or outputting the laundry is formed at the front side of the cabinet 102 , and a door for opening and closing the inlet is formed at the front side of the inlet 112 .
[0008] The tub 104 of a cylindrical shape is provided with an opening 116 at the front side thereof thus to be connected to the inlet 112 of the cabinet 102 , and a balance weight 118 for maintaining a balance of the tub 104 and reducing vibration are respectively formed at both sides of the tub 104 .
[0009] Herein, a diameter of the tub 104 is installed to be less than a width of the cabinet 102 by approximately 30-40 mm with consideration of a maximum vibration amount thereof so as to prevent from being contacted to the cabinet 102 at the time of the dehydration.
[0010] The drum 106 is a cylindrical shape of which one side is opened so that the laundry can be inputted, and has a diameter installed to be less than that of the tub 104 by approximately 15-20 mm in order to prevent interference with the tub 104 since the drum is rotated in the tub 104 .
[0011] A plurality of supporting springs 120 are installed between the upper portion of the tub 104 and the upper inner wall of the cabinet 102 , and a plurality of dampers 122 are installed between the lower portion of the tub 104 and the lower inner wall of the cabinet 102 , thereby supporting the tub 104 with buffering.
[0012] A gasket 124 is formed between the inlet 112 of the cabinet 102 and the opening 116 of the tub 104 so as to prevent washing water stored in the tub 104 from being leaked to a space between the tub 104 and the cabinet 102 . Also, a supporting plate 126 for mounting the driving motor 110 is installed at the rear side of the tub 104 .
[0013] The driving motor 110 is fixed to a rear surface of the supporting plate 126 , and the driving shaft 108 of the driving motor 110 is fixed to a lower surface of the drum 106 , thereby generating a driving force by which the drum 106 is rotated.
[0014] In the conventional drum type washing machine, the diameter of the tub 104 is installed to be less than the width of the cabinet 102 with consideration of the maximum vibration amount so as to prevent from being contacted to the cabinet 102 , and the diameter of drum 106 is also installed to be less than that of the tub 104 in order to prevent interference with the tub 104 since the drum is rotated in the tub 104 . According to this, so as to increase the diameter of the drum 106 which determines a washing capacity, a size of the cabinet 102 has to be increased.
[0015] Also, since the gasket 124 for preventing washing water from being leaked is installed between the inlet 112 of the cabinet 102 and the opening 116 of the tub 104 , a length of the drum 106 is decreased as the installed length of the gasket 124 . According to this, it was difficult to increase the capacity of the drum 106 .
SUMMARY OF THE INVENTION
[0016] Therefore, an object of the present invention is to provide a drum type washing machine which can increase a washing capacity without changing an entire size thereof, in which a cabinet and a tub is formed integrally and thus a diameter of a drum can be increased without increasing a size of the cabinet.
[0017] Another object of the present invention is to provide a drum type washing machine which can increase a washing capacity by increasing a length of a drum without increasing a length of a cabinet, in which the cabinet and a tub are formed integrally and thus a location of a gasket is changed.
[0018] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a drum type washing machine comprising: a cabinet for forming an appearance; a tub fixed to an inner side of the cabinet and for storing washing water; a drum rotatably arranged in the tub for washing and dehydrating laundry; and a driving motor positioned at the rear side of the drum for generating a driving force by which the drum is rotated.
[0019] The tub is a cylindrical shape, and a front surface thereof is fixed to a front inner wall of the cabinet.
[0020] Both sides of the tub are fixed to both sides inner wall of the cabinet.
[0021] A supporting plate for mounting the driving motor is located at the rear side of the tub, and a gasket hermetically connects the supporting plate and the rear side of the tub, in which the gasket is formed as a bellows and has one side fixed to the rear side of the tub and another side fixed to an outer circumference surface of the supporting plate.
[0022] A supporting unit for supporting an assembly composed of the drum, the driving motor, and the supporting plate with buffering is installed between the supporting plate and the cabinet.
[0023] The supporting unit comprises: a plurality of upper supporting rods connected to an upper side of the supporting plate towards an orthogonal direction and having a predetermined length; buffering springs connected between the upper supporting rods and an upper inner wall of the cabinet for buffering; a plurality of lower supporting rods connected to a lower side of the supporting plate towards an orthogonal direction and having a predetermined length; and dampers connected between the lower supporting rods and a lower inner wall of the cabinet for absorbing vibration.
[0024] The drum is provided with a liquid balancer at a circumference of an inlet thereof for maintaining a balance when the drum is rotated.
[0025] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
[0027] In the drawings:
[0028] FIG. 1 is a side sectional view showing a drum type washing machine in accordance with the conventional art;
[0029] FIG. 2 is a front sectional view showing the drum type washing machine in accordance with the conventional art;
[0030] FIG. 3 is a side sectional view showing a drum type washing machine according to one embodiment of the present invention;
[0031] FIG. 4 is a front sectional view showing the drum type washing machine according to one embodiment of the present invention;
[0032] FIG. 5 is a lateral view showing a state that a casing of the drum type washing machine according to one embodiment of the present invention is cut;
[0033] FIG. 6 is a front sectional view of a drum type washing machine according to a second embodiment of the present invention;
[0034] FIG. 7 is a front sectional view showing a drum type washing machine according to a third embodiment of the present invention;
[0035] FIG. 8 is a longitudinal sectional view of the drum type washing machine according to the third embodiment of the present invention; and
[0036] FIG. 9 is a rear sectional view showing the drum type washing machine according to the third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0038] FIG. 3 is a side sectional view showing a drum type washing machine according to one embodiment of the present invention, and FIG. 4 is a front sectional view showing the drum type washing machine according to one embodiment of the present invention.
[0039] The drum type washing machine according to one embodiment of the present invention comprises: a cabinet 2 for forming an appearance of a washing machine; a tub 4 formed integrally with the cabinet 2 and for storing washing water; a drum 6 rotatably arranged in the tub 4 for washing and dehydrating laundry; and a driving motor 8 positioned at the rear side of the drum 6 for generating a driving force by which the drum 6 is rotated.
[0040] The cabinet 2 is rectangular parallelepiped, and an inlet 20 for inputting and outputting laundry is formed at the front side of the cabinet 2 and a door for opening and closing the inlet is formed at the inlet 20 .
[0041] The tub 4 is formed as a cylinder shape having a predetermined diameter in the cabinet 2 , and the front side of the tub 4 is fixed to the front inner wall of the cabinet 2 or integrally formed at the front inner wall of the cabinet 2 . Both sides of the tub 4 are contacted to both sides inner wall of the cabinet 2 or integrally formed with both sides inner wall of the cabinet 2 thus to be prolonged.
[0042] Herein, since both sides of the tub 4 are contacted to both sides inner wall of the cabinet 2 , a diameter of the tub 4 can be increased.
[0043] Also, the supporting plate 12 is positioned at the rear side of the tub 4 and the gasket 14 is installed between the supporting plate 12 and the rear side of the tub 4 , thereby preventing washing water filled in the tub 4 from being leaked.
[0044] The gasket 14 is formed as a bellows of a cylinder shape and has one side fixed to the rear side of the tub 4 and another side fixed to an outer circumference surface of the supporting plate 12 .
[0045] The supporting plate 12 is formed as a disc shape, the driving motor 8 is fixed to the rear surface thereof, and a rotation shaft 16 for transmitting a rotation force of the driving motor 8 to the drum 6 is rotatably supported by the supporting plate 12 . Also, a supporting unit for supporting the drum 6 with buffering is installed between the supporting plate 12 and the inner wall of the cabinet 2 .
[0046] The supporting unit comprises: a plurality of upper supporting rods 22 connected to an upper side of the supporting plate 12 and having a predetermined length; buffering springs 24 connected between the upper supporting rods 22 and an upper inner wall of the cabinet 2 for buffering; a plurality of lower supporting rods 26 connected to a lower side of the supporting plate 12 and having a predetermined length; and dampers 28 connected between the lower supporting rods 26 and a lower inner wall of the cabinet 2 for absorbing vibration.
[0047] Herein, the buffering springs 24 and the dampers 28 are installed at a center of gravity of an assembly composed of the drum 6 , the supporting plate 12 , and the driving motor 8 . That is, the upper and lower supporting rods 22 and 26 are prolonged from the supporting plate 12 to the center of gravity of the assembly, the buffering springs 24 are connected between an end portion of the upper supporting rod 22 and the upper inner wall of the cabinet 2 , and the dampers 28 are connected between an end portion of the lower supporting rod 26 and the lower inner wall of the cabinet 2 , thereby supporting the drum 6 at the center of gravity.
[0048] A diameter of the drum 6 is installed in a range that the drum 6 is not contacted to the tub 4 even when the drum 6 generates maximum vibration in order to prevent interference with the tub 4 at the time of being rotated in the tub 4 .
[0049] Operations of the drum type washing machine according to the present invention are as follows.
[0050] If the laundry is inputted into the drum 6 and a power switch is turned on, washing water is introduced into the tub 6 . At this time, the front side of the tub 6 is fixed to the cabinet 2 and the gasket 14 is connected between the rear side of the tub 6 and the supporting plate 12 , thereby preventing the washing water introduced into the tub 6 from being leaked outwardly.
[0051] If the introduction of the washing water is completed, the driving motor 8 mounted at the rear side of the supporting plate 12 is driven, and the drum 6 connected with the driving motor 8 by the rotation shaft 16 is rotated, thereby performing washing and dehydration operations. At this time, the assembly composed of the drum 6 , the driving motor, and the supporting plate 12 is supported by the buffering springs 24 and the dampers 28 mounted between the supporting plate 12 and the inner wall of the cabinet 20 .
[0052] FIG. 6 is a front sectional view of a drum type washing machine according to a second embodiment of the present invention.
[0053] The drum type washing machine according to the second embodiment of the present invention has the same construction and operation as that of the first to embodiment except a shape of the tub.
[0054] That is, the tub 40 according to the second embodiment has a straight line portion 42 with a predetermined length at both sides thereof. The straight line portion 42 is fixed to the inner wall of both sides of the cabinet 2 , or integrally formed at the wall surface of both sides of the cabinet 2 .
[0055] Like this, since the tub 40 according to the second embodiment has both sides fixed to the cabinet 2 as a straight line form, the diameter of the tub 40 can be increased. Accordingly, the diameter of the drum 6 arranged in the tub 40 can be more increased.
[0056] FIG. 7 is a front sectional view showing a drum type washing machine according to a third embodiment of the present invention, FIG. 8 is a longitudinal sectional view of the drum type washing machine according to the third embodiment of the present invention, and FIG. 9 is a rear sectional view showing the drum type washing machine according to the third embodiment of the present invention.
[0057] The drum type washing machine according to the third embodiment of the present invention comprises: a cabinet 2 for forming an appearance of a washing machine; a tub 50 formed integrally with the cabinet 2 and for storing washing water; a drum 6 rotatably arranged in the tub 50 for washing and dehydrating laundry; and a supporting unit positioned at the rear side of the tub 50 and arranged between the supporting plate 12 to which the driving motor 8 is fixed and the cabinet 2 for supporting the drum 6 with buffering.
[0058] The tub 50 is composed of a first partition wall 52 fixed to the upper front inner wall and both sides inner wall of the cabinet 2 ; and a second partition wall 54 integrally fixed to the lower front inner wall and both sides inner wall of the cabinet 2 .
[0059] The first partition wall 52 of a flat plate shape is formed at the upper side of the cabinet 2 in a state that the front side and both sides are integrally formed at the inner wall of the cabinet 2 or fixed thereto. Also, the second partition wall 54 of a semi-circle shape is formed at the lower side of the cabinet 2 in a state that the front side and both sides are integrally formed at the inner wall of the cabinet 2 or fixed thereto.
[0060] The supporting unit comprises: a plurality of upper supporting rods 56 connected to the upper side of the supporting plate 12 and having a predetermined length; buffering springs 58 connected between the upper supporting rods 56 and the upper inner wall of the cabinet 2 for buffering; a plurality of lower supporting rods 60 connected to the lower side of the supporting plate 12 and having a predetermined length; and dampers 62 connected between the lower supporting rods 60 and the lower inner wall of the cabinet 2 for absorbing vibration.
[0061] Herein, the upper supporting rods 56 are bent to be connected to the upper side of the supporting plate 12 and positioned at the upper side of the first partition wall 52 , and the buffering springs 58 are connected to the end portion of the upper supporting rods 56 . Also, the lower supporting rods 60 are bent to be connected to the lower side of the supporting plate 12 and positioned at the lower side of the second partition wall 54 , and the dampers 62 are connected to the end portion of the lower supporting rods 56 .
[0062] In the drum type washing machine according to the present invention, a size of the drum can be maximized by fixing the tub in the cabinet, thereby increasing washing capacity of the drum without increasing a size of the cabinet.
[0063] Also, since the front surface of the tub is integrally formed at the inner wall of the cabinet and the gasket is installed between the rear surface of the tub and the supporting plate, a length of the drum can be increased and thus the washing capacity of the drum can be increased.
[0064] As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.
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A drum type washing machine is provided. The drum type washing machine includes a cabinet for forming an appearance; a tub fixed to an inner side of the cabinet and for storing washing water, a drum rotatably arranged in the tub for washing and dehydrating laundry, and a driving motor positioned at a rear side of the drum for generating a driving force by which the drum is rotated. The washing machine can increase washing capacity with maintaining an entire size thereof by increasing a diameter of the drum without increasing a size of the cabinet. The to washing machine may include a supporting plate to rotatably support the rotational shaft, and a supporting unit to support the supporting plate, the supporting unit comprising a plurality of supporters connected between the supporting plate and the cabinet.
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BACKGROUND OF THE INVENTION
This invention relates to improved roofing structures and methods. Various types of molded roofing tiles or shingles have been proposed in the past, formed of numerous different materials intended to attain improved structural characteristics in a roof. For example, U.S. Pat. No. 848,537 issued Mar. 26, 1907 to C. C. Davis on "Reinforced Tile Or Slab" shows a roofing tile formed of concrete containing corrugated expanded metal mesh embedded within the concrete and reinforcing it. The tiles of this patent are secured in place by lugs projecting downwardly from the tiles and adapted to be secured by bolts to angle irons attached to the rocf support structure. U.S. Pat. No. 2,142,305 issued Jan. 3, 1939 to C. F. Davis on "Building Unit And Construction" shows a number of different types of building slabs or units molded of cementitious material and having metal edge members and/or internal reinforcing sheets. Others types of shingles or tiles are shown in U.S. Pat. Nos. 912,057, 2,644,410, 881,522, 1,093,761, 4,262,466 and 1,150,425.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved molded roofing tile which can be formed of a relatively light material but is reinforced in a manner preventing breakage in use and assuring long life characteristics to a roof formed of such tiles. The tiles are desirably fire resistant and also resistant to deterioration by moisture, infestation, or other adverse conditions normally encountered by roofs continually exposed to the elements.
Certain particular features of the invention relate to unique structural arrangements designed to facilitate positioning and attachment of a series of the tiles in a proper pattern on a roof support structure, in a manner reducing the amount of time required for roofing a building, and also preventing any possibility of leakage between adjacent tiles in the completed roof.
Proper attachment of the tiles to a roof in leak preventing relation is attained by providing in conjunction with the tiles a number of mounting and protective elements which are adapted to extend between adjacent side edges of two adjacent tiles at a location to catch or intercept rain water which may fall between those edges, and direct that water downwardly at an inclination to lower ends of the tiles in a manner preventing leakage of any of that water through these protective elements and to the underlying rafters and other roof support structure. Each of these elements may take the form of a channel shaped part formed of sheet metal or the like and having a bottom wall extending between adjacent edges of two of the tiles and projecting beneath at least one of the tiles and carrying a flange projecting upwardly into a groove formed in the underside of that tile in a relation forming a guide trough within which moisture is trapped and by which it is directed downwardly to the appropriate discharge location at lower ends of the tiles. In one form of the invention, each of these protective elements has two flanges extending along opposite edges thereof and projecting upwardly into grooves formed in two adjacent tiles in water confining relation. In another form of the invention, each protective element is permanently attached to and has portions embedded within one of the adjacent tiles, and then projects from that tile beneath a next successive tile to carry a flange projecting upwardly into a groove therein.
In order to enable a tile embodying the invention to be secured to a roof support structure by a simple nailing operation without danger of splitting the tile or damaging a protective glaze or other coating applied to its upper surface, a feature of the invention relates to the provision of short nail receiving tubes embedded within the molded material of the tile body and extending downwardly therein, to provide a preformed passage within each of these tubes through which a nail can be driven downwardly into a rafter or other support structure without damage to the material of the molded body. These tubes are preferably held in place during molding and curing of the concrete or other material of which the tile body is formed, and during use of the tile, by preattaching the tubes to reinforcing material which is also to be contained within the molded substance. Desirably the reinforcing material takes the form of a sheet of expanded metal to which the tubes may be welded. In addition to the principal sheet of reinforcing material, there may also be provided two channels of such reinforcing material welded or otherwise secured to the underside of the sheet and having flanges extending downwardly, preferably at opposite sides of the previously mentioned grooves, to effectively strenghten the tile body at the critical groove locations.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiments illustrated in the accompanying drawings, in which:
FIG. 1 is a fragmentary top elevational view of a roof formed in accordance with the invention, with this view being taken on line 1--1 of FIG. 2;
FIG. 2 is a fragmentary vertical section taken on line 2--2 of FIG. 1;
FIG. 3 is an enlarged section taken on line 3--3 of FIG. 1;
FIG. 4 is an enlarged vertical section taken on line 4--4 of FIG. 1, showing the protective channel prior to attachment of any of the tiles thereto;
FIG. 5 is a section through one of the tiles which may be considered as taken on line 5--5 of FIG. 1, and which shows in full lines the internal metal reinforcing parts and nail receiving tubes as welded together prior to molding of the concrete tile body thereabout, with the concrete body of the tile represented in broken lines; and
FIG. 6 is a section taken in a plane similar to that of FIG. 5, and showing a variational form of the tile embodying the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The building roof structure 10 illustrated in FIGS. 1 through 5 includes a number of identical roofing tiles 11 assembled in a series of overlapping rows R1, R2, R3, etc. and interfitting with and located by a number of water directing protective channels 12. The tiles and channels are illustrated in FIGS. 1 and 2 as attached to a conventional roof support structure 13, including the usual parallel inclined rafters 14 and a series of spaced parallel furring boards 15 nailed to the upper inclined surfaces 16 of the rafters. The inclination of rafter surfaces 16 and the parallel upper surfaces 17 of boards 15 with respect to a horizontal line represented at 18 in FIG. 2 is such as to give the overall roof structure a desired pitch angle a.
Each of the tiles 11 is desirably of rectangular configuration as viewed in FIG. 1. With reference to the central one of the tiles illustrated in that figure, each tile has parallel top and bottom end edge surfaces 19 and 20, and has two opposite side edge surfaces 21 and 22 which are parallel to one another and perpendicular to surfaces 19 and 20. Each of these edge surfaces 19, 20, 21 and 22 is desirably perpendicular to an essentially planar upper surface 23 of the tile and an essentially planar undersurface 24 of the tile parallel to surface 23. The thickness dimension t of the tile is of course relatively small as compared with the width w and length l as seen in FIG. 1.
The main body 25 of each tile is desirably molded to the discussed rectangular shape from a light weight, fire resistant, structurally very strong concrete composition. Preferably, this concrete is of essentially the composition disclosed and claimed in my copending U.S. patent application Ser. No. 6/727,794 filed Apr. 26, 1985 on "Building Material And Manufacture Thereof". To the ingredients specified in that prior application, I preferably add a quantity of small wood particles impregnated with a substance selected from the group consisting of sodium pentachlorophenol and carbon tetrachloride, to improve the heat and sound insulative characteristics of the ultimate tiles while assuring against inflammability. The details of the process disclosed in my prior application are incorporated herein by reference. With the addition of the impregnated wood particles, the preferred composition for forming the concrete tiles includes the following ingredients in about the proportions set forth below, by weight, intermixed with water in an amount rendering the composition moldable:
______________________________________Portland Cement 70 to 94 partsGypsum 10 to 30 partsSodium Hydroxide 1 to 3 partsSodium Silicate 150 to 275 partsSolution (saturated)Particles of a metal or 1/4 to 11/2 partsmetals selected from thegroup consisting ofaluminum and zincAn Acidic Ingredient 2 to 5 parts(preferably SodiumThiosulfate)Wood particles impreg- up to about 50% of thenated with a substance total composition by weightselected from the group (preferably between aboutconsisting of sodium 25% and 50%)pentachlorophenol andcarbon tetrachloride______________________________________
These ingredients are all intermixed intimately together to form the moldable composition, and are then placed in an appropriate mold of the proper rectangular configuration (with reinforcing elements and other parts to be discussed later), and allowed to dry, preferably for a period of several days (say four days) to a hardened porous condition. The wood particles are preferably not over about 1/4 of an inch in maximum dimension, for best results between about 1/16 and 1/8 of an inch, and may be formed of virtually any available hard or soft wood, desirably the latter, such as Pines, Spruce, Hemlock, Cedar or Fir. These particles should be impregnated under a pressure sufficient to substantially fill their pores with the impregnating substance. As an example the particles may be immersed in pentachlorophenol or carbon tetrachloride at a temperature of about 70° F. and pressure of about 15 p.s.i. for a period of 1 hour.
The concrete material of the body of each tile is strenghtened by a sheet 26 of reinforcing material, which may be midway between and essentially parallel to the upper and lower surfaces 23 and 24 of the tile body 25. This reinforcing sheet 26 may have the same rectangular outline configuration as body 25, to extend continuously between opposite side edges 21 and 22 and between top and bottom edges 19 and 20. Sheet 26 desirably contains a large number of apertures distributed across the entire area of the sheet, to allow the cement composition of body 25 to enter these apertures and form an effective mechanical bond with the reinforcing sheet. In the preferred arrangement, sheet 26 is formed of expanded metal, desirably expanded steel. In addition to the sheet 26, the body 25 of each tile is also strenghtened and reinforced by two identical inverted channel elements 27 and 28 extending within the tile body near and essentially parallel to its opposite side edges 21 and 22. These channel elements, like sheet 26, preferably contain a large number of apertures distributed over their entire area, and optimally are formed of the same type of expanded sheet steel utilized in forming sheet 26. As seen in FIGS. 3 and 5, each of the channel elements 27 and 28 has a top wall 28' which is parallel to and is rigidly secured to the underside of reinforcing sheet 26, desirably by tack welding the parts together as represented at 29. Projecting downwardly from opposite side edges of the top wall 28' of each channel element, that element includes two flanges 30 and 31 which are parallel to one another and parallel to the planes of opposite side edge surfaces 21 and 22 of the tile body. Top wall 28' of each channel element and its flanges 30 and 31 extend continuously along the entire length of the tile from its upper edge surface 19 to its lower edge surface 20, with the element 27 having the cross-section illustrated in FIG. 3 along that entire length between surfaces 19 and 20.
Near the two opposite side edges 21 and 22 of each tile 11, the otherwise essentially planar undersurface 24 of that tile contains two similar grooves 32 and 33. These grooves are of uniform cross-section along the entire length of the tile body between end surfaces 19 and 20, with that cross-section being as illustrated in FIG. 3. With reference to that figure, groove 32 has a top wall 34 extending parallel to top and bottom surfaces 23 and 24 of the tile body, and has two side walls 35 and 36 extending parallel to one another and parallel to side edge surfaces 21 and 22 and perpendicular to top wall 34 of the groove. Similarly, groove 33 of each tile has a top wall 34' and opposite side walls 35' and 36' corresponding to walls 34, 35 and 36 of groove 32. Each of these grooves is preferably located within and extends longitudinally of one of the channel shaped reinforcing elements 27 or 28, with the flanges 31 of that channel being received at opposite sides of the corresponding groove.
Each of the channel elements 12 is received beneath side edge portions of two adjacent tiles, at their meeting or proximate parallel side edges 21 and 22, to assist in locating the tiles during assembly of the roof, and to subsequently function for directing moisture downwardly from the top ends 19 of two of the tiles to their lower ends 20. Elements 12 may be stamped of imperforate sheet metal, preferably galvanized sheet steel of an appropriate gauge, say 26 gauge. As viewed in FIG. 1, each channel 12 is of an elongated rectangular outline shape, having a rectangular bottom wall 37 which is planar for engaging the planar undersurfaces 24 of the tiles. Extending along opposite edges of this bottom wall, each element 12 has two flanges 38 projecting upwardly perpendicular to bottom wall 37 and extending parallel to one another and parallel to edge surfaces 21 and 22 of the tiles in the assembled condition of the parts. Element 12 has a length corresponding to the length dimension l of each of the tiles, to present a first end edge 39 lying in the plane of the upper end edges 19 of the corresponding tiles, and a second edge 40 of element 12 lying in the same plane as the bottom end edges 20 of the corresponding tiles. The channel shaped cross-section of element 12 is uniform and as illustrated in FIG. 3 through the entire length of element 12 between its end edges 39 and 40. Flanges 38 are located for reception within grooves 32 and 33 of two adjacent tiles in the FIG. 3 assembled condition of the parts, and have a vertical dimension b which is slightly less than the vertical dimension of the grooves to allow the undersurfaces of the tiles to engage the bottom walls 37 of elements 12 at 41. Bottom walls 37 are thin enough to allow nails to be easily driven downwardly through those bottom walls near top edges 39 and into boards 15 as represented at 42 in FIG. 4, to thus attach each of the channels 12 to the roof support structure 14-15 prior to placement of the corresponding tiles on the channel.
The tiles are secured in place on the supporting structure and channels 12 by nails 43 (FIG. 3) driven downwardly through the tile bodies and into boards 15 of the roof support structure. In order to prevent splitting of the tiles by these nails, and to prevent damage to a paint or baked glaze surface coating 44 which is desirably applied to the upper surface 23 of each tile, there are pre-embedded within the body of each tile a number of short desirably metal tubes 45 and 46 which extend dowardly from the upper surface 23 of the tile and have their axes perpendicular to that surface and to undersurface 24, and each of which is dimensioned to receive one of the nails 43 driven through the tube and tile perpendicular to surfaces 23 and 24. These tubes preferably have an internal diameter between about 1/8 and 3/16 of an inch. In the arrangement illustrated in FIG. 1, each of the tiles has two of the tubes 45, with these tubes being located directly above the two grooves 32 or 33 respectively near the top and edge 19 of the tile. Tubes 45 are preferably tack welded at 47 to reinforcing sheet 26, and desirably terminate downwardly at that sheet to leave a thin wall 48 of the concrete material beneath sheet 26 through which a nail must be driven in order to extend downwardly from tube 45 into and through the corresponding groove 32 or 33. In addition to the two short tubes 45, each of the tiles is illustrated as having two longer tubes 46, which are also tack welded to sheet 26 at 49, and which extend through openings in that sheet and through the entire vertical thickness of the tile between its upper and lower surfaces 23 and 24. These tubes 46 may be of the same diameter as tubes 45, and are located laterally inwardly of the expanded metal reinforcing channel 47.
In manufacturing each of the tiles 11, the expanded metal reinforcing sheet 26, expanded metal channel elements 27 and 28, and tubes 45 and 46 are first welded together as a preassembly as illustrated in FIG. 5, to hold these parts in their deisred relative orientation, and to hold the tubes 45 and 46 in a proper vertically extending position as illustrated. This welded sub-assembly is then positioned within a mold, and the concrete composition is poured into the mold about the various metal elements as illustrated by the broken lines 50 of FIG. 5. The composition is allowed to dry and cured to a hardened condition about the metal elements to thus complete the tiles. The grooves 32 and 33 may be either molded into the underside of the tile, or cut into that undersurface by a routing procedure after the tile has been completed.
In assembling the tiles and protective channels 12 on a roof, these parts are of course applied in successive rows as in conventional roofing procedures, with the row R1 of FIG. 1 being applied first, then the row R2, then the row R3, etc. In attaching the initial row R1, a workman first attaches a series of the channel elements 12 to the roof support structure in properly spaced relation, by driving nails downwardly through the upper end portions of those elements 12 as illustrated in FIG. 4. The tiles 11 are then placed on these channels 12, with the opposite side edge portions of each of the tiles being supported on two of the channels 12 as illustrated, and with the flanges 38 of the channel elements projecting upwardly into grooves 32 and 33 of the tiles. The interfitting relationship of the flanges and grooves acts to locate the tiles generally in proper positions with respect to channel elements 12, while at the same time allowing substantial lateral adjustment of the tiles relative to the flanges to permit the side edges 21 and 22 of two adjacent tiles to be brought into close proximity and preferably continuous engagement with one another. To permit this lateral shifting movement of the tiles, the horizontal width of each of the grooves is substantially greater than the thickness of the corresponding flange, preferably several times the thickness of that flange. After a particular tile has been properly positioned with respect to the supporting channel elements 12 and the engaging adjacent prepositioned tile, nails are driven downwardly through tubes 45 and 46 and into boards 15 and/or rafters 14 to positively secure the tiles in place. The nails driven through tubes 45 above grooves 32 and 33 are forced through the short wall 48 of concrete and then downwardly through the corresponding grooves and through bottom wall 37 of each of the channel elements. The tile and channels are preferably so located relative to one another as to assure such extension of the nails 43 downwardly into bottom walls 37 of the channel elements and at the inner sides of flanges 38, as illustrated in FIG. 3. The nails which are driven downwardly through the longer tubes 46 do not pass through channel elements 12. It is also noted that after one of the nails has been driven into one of the tubes, the tile is then free to pivot slightly about that nail to any desired position in adjusting the tile to a proper orientation.
After the first row R1 of tiles and channel elements 12 has been attached to the roof support structure, the second row R2 can be applied in a similar manner. As seen in FIG. 1, this second row should be so positioned that the lower end portions of the tiles of row R2 and the lower end portions of the channel elements 12 of row R2 overlap or overlie the upper end portions of the tiles and channels of row R1, and in particular overlie the nails 42 and 43 which secure the tiles and channels of row R1 in place. The next successive row R3 is similarly attached to the roof support structure in overlapping relationship with respect to row R2, and subsequent rows are in similarly overlapping relation until the entire roof has been completed. Ridge and valley tiles similar to those illustrated but specially shaped can be provided at the ridges and valleys of the roof.
After the roof has been completed, the channels 12 positively prevent any leakage through the roof at the locations between successive tiles. Any rain water which falls donwardly between the engaging edges 21 and 22 of two adjacent tiles will strike the bottom wall 37 of the underlying channel element 12, and will flow downwardly along that bottom wall for discharge onto the upper surface of a tile of the next lower row. During its travel downwardly along the inclined bottom wall 37 of the channel element, the water is confined effectively between the two side flanges 38 of that element 12, to prevent any lateral escape of the water. In this way, all water is directed downwardly from the topmost portion of the roof to its bottom edge without danger of leakage through the roof.
FIG. 6 illustrates a variational arrangement in which each of the tiles 11a may be identical with the tiles 11 of FIGS. 1 through 5 except for the manner in which a channel element 12a serving the function of the channel 12 of the first form of the invention is formed and mounted. Channel 12a of FIG. 6 has a planar bottom wall 37a corresponding to bottom wall 37 of the first form of the invention, and has two upwardly projecting flanges 38a and 38aa for engaging two successive tiles. In FIG. 6, element 12a is not handled separately from the two tiles, but rather is permanently attached to one of the tiles, specifically the righthand tile as seen in FIG. 6. Bottom wall 12a of the channel may be prewelded at 51 to nail receiving tubes 45a and 46a corresponding to tubes 45 and 46 of the first form of the invention, and flange 38aa may project upwardly into the molded cement body 25a of the attached tile. Bottom wall 37a extends along the undersurface of that molded body of the tile by which it is carried, and projects laterally beyond side edge surface 21a to locate the second flange 38a for reception within groove 33a of the next successive tile. The expanded metal reinforcing sheet 26a and expanded metal reinforcing channels 27a may be identical in FIG. 6 with the corresponding elements of the first form of the invention. In forming the tile of FIG. 6, all of the metal parts are prewelded together in a manner similar to that illustrated in FIG. 5, and with the addition of the preassembled metal channel 12a, after which the cement material is molded in place about the metal parts and to the desired configuration.
The tiles of FIG. 6 are attached to the supporting boards 15 by driving nails downwardly through tubes 45a and 46a as in the first form of the invention. Also, the tiles of each row are positioned to overlap the upper edge portions and attaching nails of the preceding row, as in FIG. 1. The channels 12a of the second form of the invention function to catch any water which flows downwardly between the adjacent edges 21a and 22a of successive tiles, with that water being confined between the flanges 38a and 38aa at the sides of element 12a, to thus be directed downwardly at an inclination within the channel element and to its lower end as in FIGS. 1 to 5 to prevent leakage of water through the roof assembly.
While certain specific embodiments of the present invention have been disclosed as typical, the invention is of course not limited to these particular forms, but rather is applicable broadly to all such variations as fall within the scope of the appended claims.
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A roofing structure including tiles preferably molded of a lightweight fire resistant cement product and having grooves at their underside adapted to receive upwardly projecting flanges of coacting elements attached to a roof support structure, to locate the tiles, and with those elements desirably being shaped to extend between two adjacent tiles at a location to intercept rain falling between the tiles and direct that rain downwardly toward lower ends of the tiles. The molded bodies of the tiles contain short tubes embedded in those bodies and defining passages within the tube through which nails can be driven to secure the tiles in place. The tubes are preferably located during production of the tiles by welding the tubes to reinforcing material contained within the tile bodies, with that reinforcing material desirably including a sheet of expanded metal mesh and two channel shaped elements of expanded metal secured to the main sheet of such material and extending about the previously mentioned locating grooves at the underside of the tiles.
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BACKGROUND OF THE INVENTION 1. Field of the Invention
This invention relates to doors for bathing fixtures such as showers and bathtubs. More particularly it provides a door of adjustable size that requires no overhead support. 2. Description of the Prior Art
In the design of doors for showers and bathtubs, it is desirable to provide as wide open access as possible and still keep the cost of fabrication as low as possible. Such access facilitates cleaning of the bathing area, and makes rooms containing such areas appear more spacious.
In U.S. Pat. No. 4,878,530, there is disclosed in one embodiment a wall mounted bathroom panel assembly where a slidable panel operates in conjunction with a pivotal panel. This assembly provides the desired open access. However, the sliding action between the pivotal and sliding panel is effected by sliding blocks having cylindrical parts which are fixed or arranged to slide in circular recesses of the panels. This sliding arrangement poses problems in that friction develops between the sliding surfaces of the blocks and the recesses and close tolerances must be adhered to for efficient operation. This arrangement also makes the adjustment of the doors relative to one another difficult. Further, a complex frame structure is required with specially designed connection pieces to support the sliding arrangement.
Moreover, U.S. Pat. No. 4,878,530 does not provide an easy means of cleaning under the panels near the pivot area, nor teaches ways in which two of such assemblies can be used together to form a four panel structure. Thus, a need exists for an improved bathing door unit.
SUMMARY OF THE INVENTION
In one form, the invention provides a pivotal and extendable bathing door unit wherein a first panel is adapted to be pivotally connected to a supporting wall with the first panel having a roller track at the upper end thereof. A second panel is adapted to be extendably connected to the first panel and also has a roller track at the upper end thereof. There is a first roller connected to the first panel that is constructed and arranged to ride in the roller track of the second panel. A guide is connected to the second panel which is constructed and arrangable to ride in the roller track of the first panel.
In a preferred form, the guide connected to the second panel is a roller and both panels also have rollers and roller tracks at their lower ends with the lower roller of the first panel being suitable to ride in the lower track of the second panel and the lower roller of the second panel being suitable to ride in the lower track of the first panel.
In another embodiment, there are camming means operatively associated with a lower end of a lateral support for pivotal connection of the first panel to provide a lifting action to the first panel upon rotation thereof.
In yet another embodiment, there are magnetic means operatively connected to a lateral edge of the second panel opposite the first for magnetic attraction to a vertically extending magnetic strip.
In still another embodiment, a three sided, discontinuous frame structure is provided for the panel members of the panels.
In yet another embodiment one of rollers is linked to an adjustment means for vertically positioning the rollers relative to the tracks.
It is, therefore, a principal object of the invention to provide a pivotal and an extendable bathing door unit of the above type which can provide a low friction operation without requiring close tolerances.
It is yet another object of the invention to provide a bathing door unit of the foregoing type which can be produced at low cost.
It is still another object of the invention to provide an extendable bathing door unit of the foregoing type wherein the roller means for providing the extendibility of the panels can be easily adjusted.
It is another object of the invention to provide an extendable bathing door unit of the foregoing type which is adaptable to various sizes of bathing facilities.
It is still a further object of the invention to provide an extendable bathing door of the foregoing type which affords a lifting thereof to facilitate cleaning purposes, and provides a stable open and closed door position.
It is yet a further object of the invention to provide an extendable bathing door of the foregoing type which can be employed as single or multiple units.
The foregoing and other objects and advantages of the invention will appear in the following detailed description. In the description, reference is made to the accompanying drawings which show, by way of illustration and not limitation, preferred embodiments of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 a top perspective view showing two of the bathing door units of this invention in conjunction with a bathing facility;
FIG. 2 is an exploded perspective view of one of the bathing door units shown in FIG. 1;
FIG. 3 is a top plan view illustrating the two folding bathing door units positioned as to fully extend the doors to a "closed" position;
FIG. 4 is an enlarged view in horizontal section illustrating a magnetic lock of the bathing door units in the closed position;
FIG. 5 is an enlarged detail view illustrating the joint between panels;
FIG. 6 is sectional view taken along line 6--6 of FIG. 5;
FIG. 7 is a sectional view taken along line 7--7 of FIG. 5; is
FIG. 8 an enlarged view, in partial horizontal section illustrating rating a bistable positionary mechanism for doors;
FIG. 9 a view in vertical section illustrating the mechanism of FIG. 8 in a first position;
FIG. 10 is a view similar to FIG. 9 illustrating the mechanism in second position;
FIG. 11 is an enlarged detail view showing an adjustment feature for the rollers at the bottom of the door; and
FIG. 12 is a sectional view taken along line 12--12 of FIG. 11.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 3, the bathing door units of this invention are shown generally at 10 and 10A in conjunction with the bathing facility 12 having a tub 13 and a shower head 14. Each of the units 10 and 10A have the same components with those of unit 10A designed by the same reference numeral followed by the letter "A". The difference is in the orientation of the panels generally 17, 19 and 17A and 19A. This is seen in conjunction with FIG. 3 where the bathing units 10 and 10a are shown in an extended or closed position with respect to the bathing facility 12.
Referring specifically to FIG. 2, it is seen that each of the bathing door units as represented by unit generally 10, is composed of two panel members 16 and 18 with panel member 16 being a slidable panel and 18 being a pivotable panel member such as will be better understood as the description proceeds. Panel generally 17 includes panel member 18 as well as a top frame 20 and a bottom frame 21. In a similar manner, panel generally 19 also has similar top and bottom frames 23 and 24 secured to the top and bottom of panel member 16. All of the frames 20, 21, 23 and 24 have roller tracks such as 28.
Positioned along the side of panel member 18 is a pivot column 26 which has a pivot bushing 31 connected thereto at its upper end by the screw 34. Pivot bushing 31 is adapted to be engaged by the projection 36 of the pivot block 33 which is attached to the expander jam 29 also by the screws 34. It should be further noted that attached to the bottom of the expander jam 29 is a pivot block 38 for engagement with pivot bushing 35 which is secured to the bottom of the column 26. This will be more fully explained later in conjunction with FIGS. 8-10. A felt seal 27 is attached to the expander jam 29 for sealing against pivot column 26. Expander jam 29 is in turn attached to a wall jam 30 by the screws 34 and, the adjustment clamps 32. Wall jam 30 is secured to the wall such as 15 (see FIGS. 1 and 3).
As seen in FIG. 2, there are roller brackets 43 and 44 attached to the ends of top and bottom frames 20 and 21, respectively; of panel 17 by means of the screws 45. Rollers 46 are rotatably mounted on the brackets 43 and 44 by means of the arms such as 70 shown in FIG. 5 and ride in tracks 28 of panel 19. In a similar manner, roller brackets 51 and 52 are attached to the ends of top and bottom frames 23 and 24, respectively, of panel 19 by means of screws 45 and ride in tracks of panel 17 as will be seen later in conjunction with the FIG. 5-7 and FIGS. 11 and 12 descriptions. Suitable end caps 48 and 54 are also provided for the respective roller brackets 43, 44, 51 and 52. Attached to the undersides of frames 21 and 24 are seals 57. Secured to one end of the panel member 18, such as by the groove 41 by a friction fit, is a seal member 39 having a side portion 40 for sealably and slidably engaging the adjacent surface of panel member 18 when panel member 16 slides thereover. Secured to the other end of panel member 16 is a handle 59 enclosed at opposite ends by end caps 61 and 62.
Referring specifically to FIG. 4, the handles 59 and 59A are secured to the ends of panel members 16 and 16A by means of the compartments 65 and 65A and an adhesive. Magnets 64 and 64A are interconnected to the handles 59 and 59A such as by the flexible sections 67 and 67A extending from the connecting portions 68 and 68A secured in slots 69 and 69A. This construction affords a releasable but retentive closure of the bathing door units 10 and 10A as also seen in FIG. 3.
FIGS. 5-7 illustrate the positioning of the rollers 46 in the tracks of the panels 17 and 19. Each of the bracket members 43 and 51 have elongated arms 70 to which are attached the rollers 46 by means of the shafts of screws 47 (See FIG. 2) which are held in a nonrotatable manner by lock nuts 72. These elongated arms 70 are interconnected to the bracket members 43 and 51 through a vertical leg portion such as shown at 71 in FIG. 6. The bracket members 43 and 51 are attached to the ends of the respective top frames 20 and 23 by the screws such as 45 passing through the slots 78 and into grooves 79. All of the frame extrusions have slots such as shown at 81 in FIGS. 6 and 7 for receiving the panel members such as 16 and 18. The panel members have been secured therein by a suitable adhesive such as Speed Bonder 324 structural adhesive and solventless activator FMD 387 both available from the Loctite Corporation in Newington, Conn.
Referring specifically to FIG. 5, there is illustrated the positioning of the arms 70 and the rollers 46 from their respective brackets 43 and 51. Bracket 51 positions a roller 46 in the roller track 28 of top frame 20 and bracket 43 positions a roller 46 in the roller track 28 of the top frame 23. These oppositely positioned roller brackets 43 and 51 also serve the purpose of providing a stop for the panel 19 as it is slid away from the panel 17. This can also be seen in conjunction with FIG. 3. Suitable resilient bumper members 49 and 50 are connected to brackets 51 and 43 for shock absorbing purposes. It will be appreciated that the same reciprocal positioning of the rollers 46 from the brackets 44 and 52 will prevail at the bottom ends of the panel members 18 and 16 for positioning the rollers in the roller tracks 28 of respective frames 24 and 21, as seen in FIGS. 2, 11 and 12. It should be noted in this regard that the lower brackets 44 and 52 have a reverse arm configuration such as 71 with respect to the top brackets 43 and 51. It extends upwardly as seen in FIG. 12 and the connecting portion 53 is reversed.
Referring to FIGS. 8, 9 and 10, these show the lifting mechanism for the panel member 18 and accordingly panel member 16. A pivot bushing 35 is attached to the pivot column 26 by the screw 91 fastened through the hole 84 and into groove 79. There are opposing holes 81 and 83 in the bushing 35 which accommodate cam pin 82. Cam pin 82 rides over the hill type cam surfaces 87 and 89 of cam member 85 and rides upwardly thereon until the cam pin rests in the opposing groves 89 and 90. When the cam pin 82 rests in the lowest portion of the cam surfaces 87 and 88, the panel members 18 and 16, will be in a lowered position as indicated in FIG. 9. When panel member 18 is pivoted, this will cause the cam pin 82 to ride up the cam surfaces 87 and 88 to ultimately rest in the opposing groves 89 and 90 to effect a raising of the panel member 18 such as indicated in FIG. 10. This raising motion affords a distance between the panel members 18 and 16 and. the upper edge of a bathing facility such as tub 13 to afford easy cleaning. As seen in FIG. 8, there is a slot 93 provided in the pivot block 38 to accommodate a lower portion of a leg of the expander jam 29 and wall jam 30. This affords a stable construction.
FIGS. 11 and 12 illustrate the adjustment feature of lower bracket member 52 and roller 46. This is afforded by an adjustment slot 96 extending through block portion 92 of the bracket 52 with slot 96 accommodating screw 45, which is fastened into frame 24. Adjustment of the height of roller 46 against track 28 in frame 21 is effected by loosening screw 45 and turning adjustment screw 95 in threaded passage 96. When the desired adjustment is made, screw 45 is retightened. As best seen in FIG. 12, a bottom seal 57 is provided having an enlarged head 74 for fitting into undercut 75 of frame member 21 as well as frame member 24.
An important feature in the fabrication of the bathing door unit 10 is the fact that there is no continuous frame structure surrounding the panel members 16 and 18. This affords ease and economy in fabrication. It should be noted that the panel members 16 and 18 are surrounded on three of their sides with frame structures such as top frame 20 and bottom frame 21 and pivot column 26 with respect to panel 18 and top and bottom frames 23 and 24 and handle 59 with respect to frame 16. They are all secured to the respective panels merely by slots in the extrusions such as 25 in pivot column 26 and 94 and 95 in frames 20 and 23 as well as the use of adhesive. Yet with only this somewhat limited structure, a rigid and very efficient sliding system is afforded by means of the brackets such as 43, 44, 51 and 55 attached to the frame members for suitable and slidable support of the rollers.
Yet another important feature is the fact that the upper frames 20 and 23 as well as lower frames 21 and 24 can be interchanged to provide left or right hand panel assemblies 10 and 10A. Upper brackets 43 and 51 can be interchanged as can lower brackets 44 and 52. This results in lower cost.
While preferred embodiments have been described above, it should be readily apparent to those skilled in the art from this disclosure that a number of modifications and changes may be made without departing from the spirit and scope of the invention. For example, in the previous description there was shown a single roller member 46 supported by the bracket arms 70. It can be appreciated that a multiplicity of roller members could be secured thereto. This would provide even a more easily slidable bath door unit. However, it would be more costly. Further, while a magnetic attraction system is shown in FIG. 4 for closing the opposing panels 19 and 19A of units 10 and 10A, the magnetic system could be employed in conjunction with one panel 19 of unit 10 and a magnetic strip such as fastened to a wall. Alternatively, these could be eliminated and still have the advantages of the simplified frame structure and roller system. The same is true with respect to the raising and lowering apparatus shown in FIGS. 8, 9 and 10.
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A pivotal and extendable bathing door unit is disclosed wherein a first panel is pivotally connected to a supporting wall, and a second panel is extendably connected to the first panel, so that the door can operate to enclose without an overhead track. There are roller tracks and rollers cross-linked to each other while permitting lateral relative movement therebetween. In one form, cam members are associated with the pivotal connection of the first panel to provide a lifting action between bistable positions, and a magnetic member is connected to a handle on the second panel for attraction to a similar second panel of a second similar door unit.
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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] The invention was made with Government support under Contract DE-AC05-76RL01830, awarded by the U.S. Department of Energy. The Government has certain rights in the invention.
TECHNICAL FIELD
[0002] This invention relates to materials for extraction and separation applications. More specifically this invention relates to a porous multi-component material comprised of a nanostructured material and a porous polymeric binder, wherein the composite material provides improved capacity, selectively, stability and kinetics for extraction, separation and other chemical applications.
BACKGROUND OF THE INVENTION
[0003] Nanomaterials provide many unique properties for chemical processes. High surface area nanostructured materials provide high sorption capacities with adjustable surface chemistries that can provide controlled selectivity and chemical reactivity. The highly selective nanoengineered sorbents have shown excellent capability in capturing variety of analytes of interest. These include the following: heavy metals and precious metals from aqueous phase; gasses such as carbon-dioxide (CO 2 ); and volatiles and semivolatiles such as explosives molecules from the vapor phase. For many chemical applications the small/fine powder form of most nanostructured materials make them impractical for utilization, particularly in the field involving catalytic separation processes and/or analytical devices that need mass flow to and from the active material. Fine powders, the form of most nanostructured materials after synthesis, are not a useful form factor for most applications. As used herein, the term form factor refers to the configuration (e.g., design and geometry) of an item or object. Further, the chemical and thermal conditions required to modify and adhere the nanomaterials to supports are often destructive to the support structures, surface chemistry, and nanomaterials. The fine structure and high surface area of the nanomaterials make them physically fragile and likely to breakdown or flake off the support during use. Chemical modification of the surface of nanomaterials (i.e. salinization, solution or evaporative deposition) requires immersion in solvents and chemicals which can harm devices. As used herein, the term device encompasses a manufactured article such as, but not limited to, a sensor device (e.g., biosensor) and a semiconductor device (e.g., integrated circuit). Integrating specific nanomaterials with specific surface chemistries is very useful for sensing, separation and other chemical applications but there are clearly significant challenges to the creation of a useful device.
[0004] For chemical collection and processing, currently used pure polymer based sorbent materials often lack capacity, surface area, as well as analyte selectivity. Polymers allow for chemical and form factor modification but lack high surface areas and high densities of chemically active sites—either would result in breakdown of the polymer materials.
[0005] Additionally, a need exists for the enhancement of thin film membranes for a range of separation applications. Incorporation of nanostructured materials into polymers offers improved performance of the thin films. The combination of these materials have resulted in enhanced properties, such as increased surface area, selectivity, permeability, hydrophobicity, hydrophilicity, thermal stability, mechanical strength, and anti-biofouling. The means to effectively incorporate the nanomaterials into the thin film membrane structures enables better membrane performance. The usage of the incorporated nanostructured materials into polymers for separation and chemical reaction applications ranges from desalination, water treatment, and catalytic reactions, to gas separation. Increasing the performance of such membranes would improve process efficacy and facilitate reduced energy consumption and physical size for major chemical processing facilities.
[0006] For analytical collections, membrane separations, catalysis and other chemical processes, what is needed is a porous composite material and method that immobilizes high surface area nanomaterials, enables access of the surface area to chemical species of interest, and methods that allow the material to be manufactured in useful forms such as thin film coupled to a substrate.
SUMMARY OF THE INVENTION
[0007] In one embodiment of the present invention, a composite material for capture and separation of a species of interest is disclosed. The species of interest may be an analyte or a material. The composite material comprises a substrate and a composite thin film. The composite thin film is formed by integration of a nanostructured material into a porous polymer. The composite thin film is coupled—or bonded, coated, or painted—to the substrate via dip coating, spin coating, drop coating, molding, casting or spray-on.
[0008] The nanostructured material may first be functionalized to be selective for the species of interest.
[0009] In some embodiments, the weight percentage of the porous polymer in the composite thin film is in a range from about 1% wt. to about 99% wt. In other embodiments, the weight percentage of the porous polymer in the composite thin film is in a range from about 5% wt. to about 40% wt. In one embodiment, the thickness of the thin film is in a range of about 0.1 μm to about 100 μm.
[0010] In one embodiment, the substrate is coated by the thin film. The substrate is, but not limited to, one of the following: a fiber, a metal wire, a bead, a planar support, flexible silica coated wire, a cloth material, or a tubular structure. The planar support can be made from glass, plastic, metals such as stainless steel, leather, rubber, wood, or combinations thereof.
[0011] In one embodiment, the surface chemistry is installed on the nanostructured material prior to inclusion of the nanostructured material into the polymer. As used herein the term installed or installation may be used interchangeably with binding or grafting, depending on the application.
[0012] The surface chemistry can form a chemically reactive layer. The chemically reactive layer is, but not limited to, at least one of the following: a sorbent or sorbent layer, a silane, a phosphoric acid, a physisorbed low vapor pressure organic, or a covalently bound surface chemistry.
[0013] The sorbent or sorbent layer may comprise of a multifunctional chemistry. The multifunctional chemistry is, but not limited to, at least one of the following: organics, organometallics, metals, nanoparticles, complex molecules, or combinations thereof. The appropriate surface chemistry is selected to enhance capture, aid in dispersion into the composite thin film and support wettability.
[0014] The species of interest is in a gas-phase or a liquid-phase. The gas or liquid-phase species is, but not limited to, at least one of the following: an explosive, an explosive variant, a chemical weapons agent, a pesticide, a drug, a volatile organic compound (VOC), a semi volatile compound, a precious metal, a toxic metal, a rare earth element, or a radio nuclide.
[0015] In one embodiment, the thin film bound to the substrate is integrated into commercially available equipment that directly interfaces with analytical testing equipment. The analytical testing equipment is, but not limited to, at least one of the following: a gas chromatographer (GC), gas chromatography mass spectrometer (GC-MS), an ion mobility spectrometer (IMS), or a head space analyzer.
[0016] The nanostructured material is, but not limited to, at least one of the following: nanoporous silica, nanofiber silica, nanoparticle metal oxide, mesoporous silica, and composites of mesoporous silica, carbon nanotube, metal-organic framework (MOF), graphene, high surface area polymer, a ceramic, mesoporous carbon, activated carbon, or a metal particle.
[0017] The porous polymer is, but not limited to, one of the following: polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), hydroxypropyl cellulose (HPC), sulfonated tetrafluoroethylene, or polyamide. The porous polymer can be used as a monomeric solution that undergoes a condensation reaction, a suspended polymer, and a fiber form.
[0018] The thin film may be deposited onto the support via dip coating, spin coating, drop coating, molding, casting, or spray-on.
[0019] In another embodiment of the present invention, a method of making a composite material for capture and separation of a species of interest is disclosed. The method includes providing a substrate. The substrate may be modified physically (i.e. roughing or etching) or chemically etched to enhance adhesion of the thin film. The method also includes coating the substrate with a composite thin film formed by combining a porous polymer with a nanostructured material. The method further includes adding functionalized chemistry on a surface of a nanostructured material.
[0020] In another embodiment of the present invention, a composite material for capture and separation of a material is disclosed. The composite material includes a substrate and a composite thin film. The composite thin film is formed by combining a porous polymer with a nanostructured material having surface chemistry for capture of the species. The composite thin film is coupled to the substrate. The weight percentage of the porous polymer in the thin film is in a range of about 5% wt. to about 40% wt. The thickness of the thin film is in a range of about 0.1 μm to about 100 μm.
[0021] In another embodiment of the present invention, a method of making a composite material for capture and separation of the species of interest is disclosed. The method comprises providing a substrate. The method also comprises coating the substrate with a composite thin film formed by combining a porous polymer with a nanostructured material. The method further comprises including functionalized chemistry on the surface of the nanostructured material. The surface chemistry may be installed on the nanomaterial prior to inclusion in the polymer.
[0022] In another embodiment of the present invention, a composite material for capture and separation of a species of interest is disclosed. The composite material comprises a composite thin film formed by combining a porous polymer with a nanostructured material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 illustrates a conceptual image of a composite material in a thin film coated on a support structure, in accordance with one embodiment of the present invention.
[0024] FIG. 2A shows an SEM image of a metal wire support coated with a composite thin film formed by combining a polymer with a nanoporous silica material.
[0025] FIG. 2B shows an SEM image of a planar support coated with a composite thin film that was formed by combining a polymer with a nanoporous silica material.
[0026] FIG. 2C shows a top view of a substrate coated with a composite thin film formed by combining a polymer with a nanoporous silica material.
[0027] FIG. 3 shows a comparison of various surface chemistries of composite thin film coated metal wires compared to a commercial polymer in the collection of vapor phase analytes in a Solid Phase Micro Extraction (SPME) configuration.
[0028] FIG. 4 shows a comparison of the effect of a porous polymer concentration on composite material surface area.
[0029] FIG. 5 shows a comparison of the effect of a porous polymer concentration on the composite thin film performance.
[0030] FIG. 6 shows a comparison of functionalized and un-functionalized composite thin films of equivalent thickness (˜10 micron thick) and thin film mass by percent removal of metals (mercury in this case) from the river water.
[0031] FIG. 7 shows a comparison of the percent uptake by the heavy metal mercury from river water versus composite thin film thickness.
[0032] FIG. 8 shows a comparison of the uptake capacity of composite thin films as function of matrix volume.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] The present invention is directed to materials and methods that provide improved capacity, selectivity, stability and kinetics for, among other things, analytical, extraction and separation applications. The materials can be applied to catalysis and other chemical reaction applications. In one embodiment, the material is comprised of nanostructured materials combined with a porous polymeric binder for adhesion and stability.
[0034] The nanostructured materials have high surface area and specific surface chemistries that provide a large a concentration of sites for analyte or material capture and/or chemical processing. The porous polymer, typically 10-30% wt., provides a binder for the nanomaterials. Using a porous polymer binder, the thin film composite overcomes one of the primary challenges to using nanomaterials—integration and stabilization into useful devices/form factors without blocking the chemically reactive sites. While the material can be formed into almost any shape, several applications discussed herein focus upon thin films. Thin films provide rapid kinetics of capture of the species of interest and can be placed upon any macrostructure desired. These thin films provide increased surface area, permeability, capacity, chemical activity, selectivity, thermal stability, mechanical strength, and anti-biofouling properties for certain separations of mixed solutions or volumes of gas.
[0035] Examples of valuable applications of the present invention include the following. The composite thin film can function as an analyte capture and concentration material for trace level detection in air or aqueous environments. Applications also include collectors for analytical systems and sensor enhancement coatings. The material can also be used for enhanced membrane separations of gasses and liquids. The composite thin films with membrane surfaces increase efficiency of separations. Further, the composite material can be utilized in a range of industrial separation applications and have been shown to provide recovery of precious metals such as Ag and rare earth metals.
[0036] In one embodiment, the surface chemistry, nanostructured material, polymer and support structure of the present invention can be synthesized or assembled separately. The resulting slurry of nanostructured materials and polymers can be deposited as desired upon a structure of interest. In this embodiment, the isolated preparation of the separate components followed by simple sequential assembly and integration is very advantageous. The ease and flexibility of deposition upon the device is very advantageous. In some cases the polymer may provide synergistic properties beyond adhesion such as increased chemical affinity or hydrophobicity/hydrophilicity of the material to enhance performance.
[0037] The present invention includes thin film compositions to be utilized as an extraction or sampling device for either gas or liquid phase materials. The device form factors that utilize the thin films can be specifically designed to work with existing sampler equipment currently in the field or in a laboratory environment.
[0038] Sampling devices constructed with thin films of the present invention have high affinity and selective capture properties to targeted species that include explosives, explosive variants or precursors, chemical weapon agents, pesticides, and other volatile organic compounds (VOCs), semi-volatile organic compounds, metals and radionuclides.
[0039] Alternatively, the composite thin films can be utilized in separation applications for target chemicals or chemical compounds in both liquid and gas environments. For example, the composite thin film devices can be used in separation applications such as carbon monoxide (CO) separation from carbon dioxide (CO 2 ) or ethanol from water.
[0040] Film support materials utilized include, but are not limited to, metal wires, flexible silica coated wires, plate structures, silica coated plate structures, cloth materials, fibers, or the inside of various tubular structures. These support materials can be coated with various layers of the thin film to provide desired characteristics of the sampling device.
[0041] Compositions of the thin film coating the support may comprise several materials. Materials used in the thin film coatings include a pure or unmodified mesoporous silica support, nanofiber silica, ceramic composite, high surface area polymer, or other nanostructured materials such as carbon nanotubes, metal organic frameworks (MOFs), nanoparticles, graphene, mesoporous carbon, or activated carbon. The ceramic composite sorbent material may consist entirely of ceramic or of a hybrid ceramic polymer/organic composite.
[0042] The thin film coatings can be applied in multiple layers to increase thickness or surface area as well as for adhesion enhancement. Further, multiple layers can provide increased mechanical properties such as stiffness while also controlling the thermal properties of heating and cooling. The thin film material can be applied in any standard way and deposited onto the support by dip coating, spin coating, drop coating, molding, spray-on, casting, and other techniques. Additionally, the material can be packed into a sorbent column for performing extraction by way of a packed sorbent.
[0043] The use of a nanostructured material, which can be a nanostructured ceramic, and a porous polymer in a thin film composition improves stability and adhesion and promotes mass flow for better sampling. The process does not require a high temperature sintering process to effectively bind the sorbent material to the sorbent structure. The ability to pre-functionalize sorbent materials prior to installation on sampling devices allows for maximum functionality and ease of uniform manufacture.
[0044] A variety of surface functionalizations can be installed through silane chemistry methods on the sorbent materials. The sorbent surface chemistries selected can have attributes of selectivity, thermal stability and high affinity to various species of interest depending on the application. This method results in a more uniform thin film. The use of ceramic and polymer can stabilize normally unstable materials that are desired to be used for their high capacity properties.
[0045] In one embodiment, beneficial performance and practical application can be achieved through the optimization of the composition of silica or other porous support and polymer without the destruction of sorbent functions. A silica and polymer slurry may be coated on stainless steel wires, planar or other supports, to overcome the disadvantage of fragile substrates found commercially. Composites of the present invention provide a desired surface chemistry, retention of nanostructure, and chemical activity while resolving issues with adhesion to the surface and degradation during use.
[0046] Chemically modifying the surface of the nanostructured material to increase affinity toward the material of interest may be conducted by pre-installation of the sorbent on the nanostructured material. Pre-functionalization allows for an increase in the varieties of functional groups utilized as well as simplifies the functionalization of the materials.
[0047] The nanostructured material can be made as a thin film coating on most support structures or as three-dimensional shapes (e.g., particles and monoliths). Some specific applications for the nanostructured material includes the following: Solid Phase Microextraction (SPME) or large volume solid phase extraction and trace sampling; explosive detection; chemical weapons and toxic industrial chemical capture; radionuclide separation and detection; vapor or liquid phase sampling; chemical separation, including rare earth separation, uranium separation, and recovery of precious metals; organic detection; sensor enhancement; low temperature catalyst process; membrane separation applications; and chemical processing.
[0048] The present invention includes materials for improved capacity, selectivity, stability, and extraction efficiency for chemical separation and collection applications. The materials can be applied to catalysis, battery and other chemical reaction applications. The invention described herein details multiple configurations. While the material can be formed in most any shape, most applications discussed herein focus upon thin films. Thin films provide rapid kinetics and can be placed upon any macrostructure desired. The composite material, in one embodiment, is comprised of nanostructured materials combined with a porous polymeric binder for enhanced adhesion and stability. The nanostructured materials have high surface area and can have specific surface chemistries that provide numerous (sometimes more than 5 ligands/nm 2 ) reaction sites for analyte or material capture and/or chemical processing. The polymer, typically, but not limited to, 1%-99% wt. or 5%-40% wt. and porous, provides a binder for the nanostructured materials. Using a porous polymer binder in the material overcomes one the primary challenges to using nanostructured materials for practical chemical applications—integration and stabilization into useful devices and form factors without blocking the chemically reactive sites.
[0049] A graphical example of a composite material in a thin film coated on a support structure, in accordance with one embodiment of the present invention, is shown in FIG. 1 . In FIG. 1 , the strands show the binding polymer materials. The flexible ropes represent porous polymeric material binding the chemically active nanostructured material in place. In this image the nanostructured material is shown as porous spheres. The porosity provides high surface area which provides high chemical reactivity. The arrow indicates a blow up of one of the pores showing the surface chemically modified to enhanced chemical activity. The graphic illustrates and suggests a high density self-assembled monolayer on the nanomaterial surface. Other materials, structures and surface chemistries can be used and have been reduced to practice. Thin films are a desirable form factor since they provide rapid kinetics and can be installed upon many microstructures.
[0050] In addition to the composite thin film functioning as a species capture mechanism for trace level detection in both air and aqueous environments, the composite thin film can be utilized in separation applications. These thin films provide increased surface area, permeability, capacity, chemical activity, selectivity, thermal stability, and mechanical strength for certain separations of mixed solutions or volumes of gas. Altering film composition layers can control the physical, kinetic and chemical separation properties of certain devices. Example applications include membrane separations of gasses and liquids. The composite thin films could modify both the internal and external membrane surfaces increasing efficiency of separations. For example, usage of the composite thin film technology could improve flux and performance for desalination membranes, membranes for gas (i.e. CO from CO 2 ) or liquid separation (ethanol from water), catalytic reactions, or improve recovery of precious metals such as gold (Au), silver (Ag), platinum (Pt), and rare earth metals.
[0051] The nanostructured materials can be assembled using techniques such as surfactant templated sol-gel or self-terminating nanoparticle synthesis. The support structure (wires, sensor surfaces, meshes, etc.) can be manufactured using established techniques. The polymers are commercially available as liquid or solid precursors. The desired surface chemistry can then be installed on the nanostructured material using known methods such as silanization, evaporative deposition and acid-base reactions. The (possibly surface modified) nanostructured material can be dispersed into the polymer with solvent as needed. Further, dispersion of material and homogeneous slurry can be enhanced by using stirring, shaking, and/or sonication techniques. The resulting slurry of nanostructured material(s) and polymers can be sprayed, spin coated, dropped, dipped, painted, or otherwise deposited as desired upon the structure of interest. In some cases, the polymer may provide synergistic properties beyond adhesions such as increased chemical affinity or hydrophobicity/hydrophilicity of the material.
[0052] Nanostructured ceramics such as alumina, titania and silica materials possess large surface areas and retain chemical, thermal and mechanical stability. For example nanoporous (i.e. MCM-41), nanofiber (i.e. cabosil) and amorphous silica have been successfully utilized. Further, a wide range of surface chemistries can be installed on the silica (and other materials) with established chemical process methods, including silanization, to increase affinity and selectivity toward various chemicals of interest. Other high surface area nanostructured materials, such as carbon nanotubes, MOFs, metal oxide materials, graphene, mesoporous carbon, or activated carbon, can also be utilized in the composite thin films. Each of these high surface area structures provide unique advantages when properly combined with a selected polymer to create a specific polymer-nanomaterial composite for enhanced chemical processing/sampling. For smooth thin films particle sizes of less than 0.5 microns were preferred. Larger particle sizes (>0.5 micron) maintaining both nanoporosity and significant surface area resulted in textured and uneven surface properties—which might be desirable if turbulent flow over the surface or surface texture is desired.
[0053] The composite thin films of the present invention have the added benefit of high overall surface area, due to the high surface area nanomaterial and the structural and adhesive support of a polymer network. This translates into a device that has flexible and selectable surface chemistry and is more stable than current devices. Further enhancement of the material may be achieved by optimizing the composition of nanostructured material to polymer ratio to maintain high surface area and sufficient stability/adhesion. The nanocomposite film coatings of the present invention have shown success in the extraction of vapor phase analytes in a SPME configuration as well as other embodiments such as thin films applied to surfaces for collection from aqueous environments for heavy metals, precious metals, radionuclides and semipolar organics. These materials have been tested for the sampling and detection of radionuclide particles.
[0054] The composite material can be coated on a range of surfaces. Selected examples are shown in FIGS. 2A , 2 B, and 2 C. This approach combines the high surface area and controllable surface chemistry of nanostructured materials, such as porous silica, with the flexibility and durability of a polymer coating. The porous thin film coatings provide extremely rapid kinetics and enable a range of analytical applications that benefit from thin films. These include X-ray fluorescence (XRF), alpha particle spectroscopy, and infrared (IR) spectroscopy.
[0055] SEM images of nanomaterial silica and polymer coatings on metal and planar supports are shown in FIGS. 2A and 2B , respectively, and FIG. 2C shows a top view of a substrate coated with a composite thin film formed by combining a polymer with a nanoporous silica material.
[0056] Referring to FIG. 2A , which shows a SEM image of a metal wire support coated with a composite thin film formed by combining a polymer with a nanoporous silica material, the sorbent materials bound by the polymer material are clearly visible. The composite thin film has surface area of 642 m 2 /g. It was composed of 90% wt. MCM-41(was milled to less than 0.5 micron particle size) with 10% wt. Nafion®. Nafion® is a commercially available porous polymer that has a hydrophobic/hydrophilic structure. It has been widely used in various fields in different conditions due to its highly stable characteristics in a variety of chemicals (solvents, salt, acid, and alkaline solutions), high operating temperature, good performance under humidified condition, and antibiofouling properties. Nafion® is easily fabricated in various forms and on various substrates depending on specific properties applications. The film shows the addition of various layers, like tree rings, added to increase capacity of the sorbing thin film. In this case additional layers were added, to increase film thickness and capacity, by dip coating in polymer-particle slurry.
[0057] Referring to FIG. 2B , which shows an SEM image of a planar support coated with a composite thin film that was formed by combining a polymer (10% wt. Nafion®) with a nanoporous silica material (90% wt. of 0.5 micron MCM-41), the composite thin film has surface area of 642 m 2 /g. In this case the film was applied by drop coating deposition. In this case a drop of MCM-41/polymer slurry on the top of cover, spread the slurry, remove the excess of slurry from the edge of cover, then dry the coatings at room temperature and 50° C. for overnight. Screening printing, doctor blading, spin coating and other techniques are also effective deposition methods, particularly with thinner films are desired. Additional layers could be added, to increase film thickness and capacity.
[0058] Referring to FIG. 2C , this particular composite thin film has surface area of 642 m 2 /g. It was composed of 90% wt. MCM-41 (was milled to less than 0.5 micron particle size) with 10% wt. Nafion®. The surface can be seen to be reasonably uniform. The larger microstructured holes, typically formed during curing of the film, provide opens to enhanced mass transport into the film. Film composition and process conditions can be controlled to enable the desired porosity and surface smoothness.
[0059] In the SPME application metal wires and traditional silica fibers have been explored, as shown in FIGS. 2A-2C and FIG. 3 . The nanocomposite thin film has been incorporated into a SPME device that has shown many advantages over the commercial device currently being used. The nanocomposite increases surface area/sorbent capacity by up to 30,000 times (thickness and formulation dependent) over unmodified surfaces. The nanocomposite film can exceed the best polymer film performance with an example shown in FIG. 3 and later in table 1. Surface chemistry modification is non-trivial but the full range of silane chemistries can be installed on the nanomaterial, typically silica to date, for targeting various species of interest. Silica and other nanostructured ceramics are also chemically and thermally stable. Using a nanocomposite coating addresses many of the stability issues existing with commercial devices. The nanocomposite film coatings have shown success in the collection of vapor phase analytes in, for example, a solid phase micro extraction SPME configuration of FIG. 3 .
[0060] For the example of FIG. 3 , the composite thin films were composed of 90% wt. nanostructured materials and 10% wt. Nafion®, with equivalent thickness. The collected analyte—2,4-Dinitrotoluene, DNT, in this case—was thermally desorbed and analyzed by gas chromatography after exposed to the analyte vapors in sealed chamber for 20 hours. The performance of the composite thin film was reported in terms of “response normalized volume” which is defined as the obtained response per thin film volume of nanocomposite thin film normalized to response per thin film volume of the commercial polymer polydimethylsiloxane (PDMS). The composite thin films, even with raw nanostructured silica, do better than simple polymer films presently produced as commercial products. The addition of surface chemistry to the nanostructured material in the film increases the sorbent material affinity for collection of analytes or materials. In this case phenyl showed high affinity for collecting DNT in vapor phase. Performance of the composite thin film can be further improved by adjusting surface chemistries to provide more affinity capacity or selectivity. For example, phenyl functionalized silica/Nafion® composite signal was more than 2 times the commercial (PDMS) SPME signal. Functionalization using an organometallic complex is expected to further increase relative performance
[0061] Clearly, as shown in Table 1, the improvement of surface chemistries can enhance chemical affinity and selectivity of the composite material. It summarizes the performance of various nanostructured materials, different surface chemistries, and traditional materials incorporated into a polymer for vapor collection from an air sampling, 2,4-Dinitrotoluene (DNT) vapors in this case. The performances of composite thin film are reported in the term of “relative mass capture” which is calculated from the mass of the captured analyte per mass of the composite thin film normalized to the mass of the captured analyte per mass of the pure polymer. These nanostructured material composite coating/films provide significantly improved collection capacity, greater capability than a pure polymer, Nafion® in this case. Chemically modified nanostructured materials (phenyl, organometallic complex, and thiophene in this case) provide further improvements in terms of mass and volume of thin films. Thiophene on mesoporous carbon demonstrates the highest performance per unit mass of all composite thin films. Meanwhile, the europium organometallic complex europium-thenoyl trifluoro acetone (Eu-TTA) on mesoporous silica shows the best performance per unit volume of composite thin film. The different sorption abilities of each respective nanostructured material, obtained are impacted by many factors including the surface chemistries, chemical selectivity of the vapor, the formation/bonding between material and polymer, and porosity of the composite thin films. The composite thin films coating glass discs (25 mm diameter) were composed of 60% wt. nanostructured material and 40% wt. Nafion®.
[0000]
TABLE 1
DNT vapor collection with composite materials comprising different
nanostructured materials and chemistries integrated with a polymer
Thin Film Composition (with 40% Nafion
Relative
wt./wt.)
mass capture
Pure polymer
1
Iron Oxide Nanoparticles integrated polymer
9
Nanofiber Silica
17
Metal Oxide Framework (Basolite ® C 300)
23
Mesoporous Carbon
85
Nanoporous Silica
100
Phenyl Modified Nanoporous Silica
107
Eu modified Mesoporous Silica
114
Thiophene modified mesoporous carbon
121
[0062] The data for Table 1 was obtained by allowing fibers to contact and saturate with DNT vapors or until phase equilibrium was reached. A liquid extraction technique was employed to quantitatively remove the captured DNT from the composite thin film. A solvent—acetone in this case—was placed on the exposed sample in a vial, then sealed with screw cap, and sonicated for 30 minutes. The supernatant was separated and subsequently analyzed with a GC-MS.
[0063] The research and development process of the composite thin film materials experimented with various nanostructured materials and polymers incorporated in various combinations and concentrations for optimum performance. For example, two primary film qualities were notable in the SPME configuration where a composite thin film was applied to a rigid support wire. A high surface area sorbent material such as nanoporous silica provided the necessary species capture sites to improve overall performance of the new SPME device. A number of polymers such as PDMS, HPC, and Nafion® were tested.
[0064] Film stability and surface area was achieved by using only 10% polymer in the film as a binder for the nanomaterials. This polymer concentration provides a well adhered film to the wire support and provided excellent analytical repeatability. The structure of composite thin films and performances are primarily dependent on the material loading and polymer composition. Both components play important roles in the availability of binding sites, sensitivity, permeability, adhesion, and the stability of the thin film coating. As seen in FIGS. 4 and 5 , when too much polymer concentration was used in the composite composition a decrease in surface area and performance was observed. However, when the polymer concentration is too low the result is a thin film with poor adhesion, cracking of the thin film, and loss of the nanomaterial due to insufficient amounts of the polymer to act as a binder. Similar trends were observed with other polymers and nanomaterials. The best performance with practical application can be achieved through optimization of the nanomaterial loading and polymer composition. Sensitivity of nanoporous silica/polymer coating on stainless steel wire depends in part on the large surface area of nanoporous silica. As a consequence of increasing polymer concentration, the overall surface area of the composite material decreases. Optimization of the composite ratios provides high surface area chemical collection or reaction, reproducible results, good film structures, and surface adhesion/stability. Optimization of the thin film composition is needed for each application depending on environmental use (e.g., phase of analytes, mechanical strength, flexibility, abrasion, durability, and other forces).
[0065] FIG. 4 shows a graphical representation of the effect of a porous polymer (Nafion® in this example) concentration on composite material surface area. As the capture of species is expected to mostly occur onto the surfaces of nanostructured sorbents, the large surface area and volume of thin film are key aspects for achieving the high adsorption capacity of analytes. Therefore, the optimization of composite film is important for stability of the composite film and for the high surface area of nanoporous silica to interact with analytes. In this case the nanostructured material used was nanoporous silica (MCM-41) milled to less than 0.5 micron particle size). Clearly as polymer percentage increases the available surface area for chemical processes decreases—or reduce chemical activity of film on a per volume basis. However, as the polymer percentage increases the stability of the film increases resulting in an optimal range (percent weight of polymer and nanostructured material) which is material and application specific. Other polymers and nanomaterials show similar trends.
[0066] FIG. 5 shows the effect of porous polymer concentration on the composite thin film performance. In this example nanoporous silica (MCM-41 milled to less than 0.5 micron particle size) was used and formed with a polymer (Nafion®) on metal wires. The collected species of interest—DNT in this case—was thermally desorbed and analyzed by gas chromatography after exposed to the species vapors in a sealed chamber for 20 hours. Polymer concentration directly affects the capability and stability of thin film for applications. The capture ability of composite thin film is decreased when increasing the polymer composition. The capture ability of the composite thin film strongly depends on the amount of nanostructured material contained in the film.
[0067] DNT was chosen as a representative explosive for evaluation of the performance of polymer-nanoporous silica composite thin films due to its semi-volatile pressure, and the sampling of DNT vapor at room temperature has been routinely demonstrated. It demonstrates analogous to other materials of interest in the gas/vapor phase. The performance of composite thin films are reported in the term of “response normalized volume” which were calculated from the obtained response per thin film volume of nanocomposite thin film normalized to the commercial polymer PDMS. The polymer PDMS is a standard widely utilized collection media. In this case the polymer was Nafion® and nanomaterial was mesoporous silica—with particle size milled to less than 0.5 microns.
[0068] The capture ability of the composite thin film is decreased when increasing the polymer composition, as a consequence of decreasing surface area of the composite thin film (see FIG. 4 ). Additionally, gas permeability of the thin film decreased when the loading of nanoporous silica was decreased. The capture ability of the composite thin film strongly depends on the amount of nanostructured material contained in the film as DNT capturing mainly occurs on the nanoporous silica surface. However, less polymer results in the instability of thin film. Therefore, enhanced performance with practical film stability can be achieved through optimization of the nanomaterial loading and polymer composition for each application. Other materials show similar trends.
[0069] Another example is increased vapor collection from an air sampling device with a functionalized composite thin film coating. The data in Table 2 shows the enhanced capture for DNT vapors with the various modifications of the materials. As shown in Table 2 the addition of a typical polymer coating, PDMS in this case, is helpful for collection. The addition of a nanostructured material composite coating/film provides significantly improved collection capacity. Using chemical modified nanostructured materials—phenyl silanes installed on nanoporous silica in this case—provides further improvements. As shown in Table 2, improvements of over 5000 times are possible. The chemical selectivity of the vapor and capacity of the device will be affected by the choice of polymer and surface chemistry of nanomaterial utilized. Other gasses and surface chemistries can be utilized.
[0000]
TABLE 2
Effect of composite thin film coating on metal fibers.
Vapor capture
Vapor Capture
Collection Material*
(μg DNT/cm 3 )
Enhancement
Mesh Fibers
0.054
1
Metal fibers with PDMS coating
32
~600
Nanoporous silica/PDMS
253
~4700
composite coating on metal
fibers
Phenyl modified Nanoporous
294
~5400
silica/PDMS composite coating
on metal fibers
*The data for Table 2 was obtained by allowing fibers to contact and saturate with DNT vapors or until phase equilibrium was reached (48 hours in this case). A liquid extraction technique was employed to quantitatively remove the captured DNT from the composite thin film. A solvent - acetone in this example - was placed on the exposed sample in a vial, then sealed with screw cap, and sonicated for 30 minutes. The supernatant was separated and subsequently analyzed with a GC-MS. The thin films were composed of 10% wt. of polymer - PDMS in this example - and 90% wt. of a nanostructured material (all material milled to less than 0.5 microns particles size). The metal fiber weight gains ≦1% after coating with a composite thin film.
[0070] As one specific example for making a cylindrical SPME vapor collector device with phenyl nanoporous SiO2/PDMS composite coating (last sample in Table 2), the coating was composed of 16.7% wt.of PDMS and 83.3% wt.of phenyl modified MCM-41 silica. The composite coating slurry was prepared by mixing ball milled Phenyl modified nanoporous silica (MCM-41)/isopropanol slurry with fresh made PDMS. The slurry contains 2 wt % Phenyl modified MCM-41, 0.4 wt % PDMS, 41 wt % water and 56.6 wt % of isopropanol. The slurry was dip coated on metal fibers. Multiple layers of coating were applied on the metal fiber to achieve 15-30 mm coating thickness.
[0071] As one specific example for making a planar collector device for the capture of metals in liquids, SH-silica was made with known silane methods (i.e. refluxing in reactants in toululene). Thiol propyl silane was reacted with a high surface area nanofiberous cabosil to form high surface area SH functionalized silica, which has a high affinity and capacity for softer metals such as Hg, Ag, and Pb. The SH-Cabosil composite thin films were made of 55 to 70% wt silica sorbent material and 30-45% wt Nafion®. The particles of SH-Cabosil silica were dispersed in the polymer solution (used as received) by sonication for 15-30 minutes prior to coating on planar substrate discs. The thin film used was allowed to air dry overnight. Thicker films can be made with multiple coatings. Oxide materials, including manganese oxides, iron oxide, and their composites, which have high affinity toward various metals—especially toxic and precious metals—can be simply mixed into the polymer solution and deposited as previously described. The manganese oxide composite thin films have showed a high capacity for adsorption of trace metals from natural waters.
[0072] Embodiments of the present invention include thin films applied to planar surfaces such as glass, stainless steel, metal or plastics. These planar supports have shown to be effective for separation and chemical sampling in aqueous environments. In one application, the functionalized nanostructure sorbent materials have been combined with the polymer Nafion®, and the composite material was applied as a thin film to the planar support (see FIGS. 2A and 2B ). The planar disks—as glass, stainless steel or polymer—were exposed to river water spiked with a certain amount of mercury (Hg). Functionalized and un-functionalized composite thin films of equivalent thickness and thin film mass are compared by percent removal of Hg from river water as data shown in FIG. 6 , FIG. 7 , and FIG. 8 . With the appropriate composition, the composite thin films clearly provide an excellent platform for removal of other metals from aqueous environments. Further, these composite thin film materials have been tested in the application of sampling and detection of radionuclide particles. Planar films are of particular interest to many analytical applications requiring thin film for assay such as XRF and alpha spectroscopy. The same coatings on filters and fibers are of interest to resource recovery, remediation and industrial process applications.
[0073] FIG. 6 shows a graphical representation of a composite thin film used for Hg removal in river water. The composited thin films were coated on glass discs of 25 mm diameter. They were composed of 70% wt. nanostructured materials and 30% wt. Nafion®. The coated and uncoated discs were contacted with 50 mL river water containing ˜100 ppb Hg at neutral pH and shaken continuously at 120 rotations per minute (rpm) over 24 hours. Liquid per solid ratio in this case was 50 L/g sorbent according to the nanostructured material contained in the composite thin film. After the phase equilibrium was reached, the solution before and after contact with the composite thin film was analyzed for detecting Hg by ICP-MS. The thin film clearly helps with capture/removal of Hg from river water. The thiol (SH—) modified nanoporous silica of 5 μm particle size clearly provided better performance than the unmodified silica nanomaterial of 5 μm MCM-41 in this case. The capacity of SH-nanoporous silica is not significantly reduced even though the material is bound to the support with a polymer, compared to the SH-nanoporous silica at the same liquid per solid ratio. The surface chemistries of the composite thin films can be simply installed, adjusted and optimized for specific metals (other toxic metals, basic metals, precious metals, and radionuclides) and environmental application (salt waters, acid waters, etc.).
[0074] It can be observed that the composite thin film material, particularly with appropriate surface chemistry (thiol for mercury in this particular case) enables effective collection from aquatic environments. It is clear from FIG. 6 that the increased uptake of soft metal ions by the composite thin film—achieved from the capability of functionalized sorbent as a percent uptake of Hg—was increased almost 3 times when compared to the thin film of Nafion®-nanoporous silica. Similar trends can be seen in Table 3 and exact performance enhancements are dependent upon materials, configuration and solution conditions. Nafion® has selectivity for cations through its hydrophilic negatively charged sulphonate group, however it appears to have only minor impact for the uptake of these metals when compared to the highly selective binding of thiol and large surface of nanoporous silica. The result indicates that Nafion® acted as a hydrophilic porous binder allowing metal ions to diffuse through the composite and is not acting as the principle adsorbent. The affinity and ability in binding of the materials were not significantly reduced in the format of a thin film. This suggests that, beside the very high functional density, the material does not lose the active binding sites when used with Nafion®.
[0075] Table 3 shows performance of composite thin film, functionalized nanostructured material, and traditional sorbents for recovery of precious and toxic metals from river water. The sorption affinity of the sorbents was calculated and presented in the term of distribution coefficient (K d , mL/g), as well as the percent captured from solution. The K d is simply a mass-weighted partition coefficient between solid phase and liquid supernatant phase. The composite thin film of this invention clearly has higher capture efficiencies than traditional sorbents, as shown in Table 3. The performance of the composite thin film has comparable performance with a pure functionalized nanostructured material, but it is in a form factor that enables specific applications (like analysis or low back pressure separations). The composite thin films show better capacity than commercial materials typically used for heavy metal collection from liquid phases (i.e. waste, water treatment natural waters). The thin film format may readily be used in low backpressure and membrane extraction systems. Similar performance can be expected from other applications not involving heavy metals. The data was obtained and compared at similar conditions of sorption contact; neutral pH solutions, liquid per solid ratio of 50,000 g/mL (except, Ag uptake by composite thin film was perform at liquid per solid ratio of 25,000), equilibrium phase data. The composite thin film for Ag and Hg uptake were made from 55% wt. and 70% wt. of SH-nanostructured silica, respectively. Thin films were coated on stainless steel discs of 22 mm diameter and glass disc of 25 mm diameter for Ag and Hg uptake, respectively. The thin film contained ˜1 mg functionalized nanostructure silica. The thickness of the thin film was ˜10-15 μm. For Ag uptake, the experiment was performed in 25 mL of river water; initial concentration of Ag ˜60 ppb, pH of solution throughout the experiment was ˜5-6.5 during 24 hours of contact time. For Hg uptake, the experiment was performed in 100 mL of river water; initial concentration of Hg ˜100 ppb, pH of the solution throughout the experiment was ˜7.0-7.6. The comparison experiments with commercial sorbents and SH-nanostructured silica were performed at initial concentration of Ag and Hg ˜30 ppb at pH ˜6.0 (except, SCX, pH at equilibrium was 7.2), batch sorption contact were continued over 2 hours.
[0000]
TABLE 3
Collection of Ag and Hg with thin film and resins from river water
Ag
Hg
K d
Capture
K d
Capture
Sorbent materials
(mL/g)
(%)
(mL/g)
(%)
Thin Films
SH-Cabosil Composite Thin
750000*
97*
3000000
98
film
SH-Nanoporous Silica
650000
93
960000
95
Composite Thin Film
Component Materials
SH-Cabosil Silica
5300000
99
4500000
99
SH-Nanoporous Silica
4500000
99
3600000
99
Bare Cabosil
4000
8
0
0
Bare Nanoproous Silica
200
4
0
0
Commercial Materials
Activated Carbon
4700
9
150000
75
(Darco KB-B)
Strong Anion Exchange Resin
5400
10
39000
0
(SAX)
Strong Cation Exchange Resin
450000
89
160000
76
(SCX)
Chelex 100
6000
11
69000
58
*data was obtained from liquid per solid ratio of 25,000 mL/g sorbent.
Distribution coefficient (K d ) is simply a mass-weighted partition coefficient between solid phase and liquid supernatant phase. K d is a solid phase partition coefficient similar to the more commonly used solution phase equilibrium constant and represents an empirically measure of chemical affinity (for the specific conditions).
[0076] FIG. 7 shows a specific example for the capture of heavy metals—Hg in this case—from water, for sensing or remediation applications, as a function of film thickness. Film thickness is a significant parameter for thin film applications targeting analyte collection from either air or liquid environments. Thicker films offer increased capacity by bolstering film volume and available binding sites needed for species capture. However, thicker coatings suffer from reduced mass transfer as access to the binding/chemical reaction sites deeper in the film becomes harder. As shown in FIG. 7 , performance of the film does not increase after a certain thickness (depending upon time, mass flow to surface, film composition, film chemistry, and whether the functional media is gas or liquid). Therefore, an optimized thin film thickness is applied for each application depending on use. The thin film in this experiment was made from 70% wt. SH-nanoporous silica and 30% wt. Nafion® by coating the composite solution on glass discs of 25 mm diameter. The effect of film thickness in adsorption of soft metals from liquid phase was evaluated with two matrix volumes of 50 mL and 400 mL at a neutral pH containing ˜100 ppb of Hg ions. The percent uptakes of Hg from river water versus film thickness are shown in FIG. 7 . Similar uptake trends can be seen from both matrix volumes; the maximum Hg uptakes occur at a film thickness of approximately 20-40 μm and remained constant. This indicates that the Hg ions were only able to penetrate through the thin film and bind with available SH-sites at maximum thickness of 40 μm. A constant percentage uptake of Hg was seen as film thickness increased indicating that no mass transfer occurred beyond ˜40 μm. It is clear that mass transfer in the film has a significant negative effect in adsorption of Hg ion from liquid phase past a certain thickness.
[0077] The lower percent uptake of Hg from the larger water volume (400 mL vs. 50 mL) percent uptake in FIG. 7 can be clearly seen. However, in terms of mass uptake, the total Hg uptake was up to 21 μg by 40 μm thick composite film from a water volume of 400 mL. On the other hand, only ˜5 μg of Hg was obtained from 50 mL by a thin film with equivalent thickness. The lower percent uptake of the 400 mL volumes when compared to the 50 mL volume is a function of chemical equilibrium and the saturation of the thin film sorbent. This is further shown in FIG. 8 .
[0078] FIG. 8 shows the uptake capacity of the composite thin films of the invention as a function of volume of river water. The capacity of the selected thin film disks were tested using composite thin film with 15 μm thickness (and equivalent mass). The thin film coated glass disc of 25 mm diameter contained 2 mg of SH-nanoporous silica (70% wt. sorbent, 30% wt. Nafion®). The thin films were exposed to river water (pH ˜7 containing Hg ˜100 ppb) of different volumes from 50 mL to 500 mL for 48 hours. Increasing mass uptake of Hg was achieved as the matrix volume increased. This is because the larger water volume contains a higher number of Hg ions, and the SH-nanoporous silica composite thin film possesses a high density of available binding sites, resulting in higher uptake of the metal ions (this is regulated by SH-modified sorbent affinity and the ratio of sorbent volume to solution volume). The near linear trend of Hg uptake suggests that the thin film was not saturated, and was able to adsorb more Hg until the film was saturated. This result demonstrates that the SH-nanoporous silica composite thin film is able to adsorb the Hg at performance levels above 12 mg/g of SH sorbent. The composite thin film shows higher adsorption of Hg ions in river water than that of various commercial sorbents as compared at the same liquid per solid ratio. Commercial sorbents (such as activated carbon, Chelex® 100, MnO 2 sorbents, phosphonic resins, anion and cation exchange resins) were able to uptake Hg ions less than 1 mg/g sorbents at liquid per solid ratio of 50000 mL/g sorbent, while the SH-nanoporous silica incorporated thin film was able to uptake Hg ion up to 5 mg/g sorbent.
[0079] The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of the principles of construction and operation of the invention. As such, references herein to specific embodiments and details thereof are not intended to limit the scope of the claims appended hereto. It will be apparent to those skilled in the art that modifications can be made in the embodiments chosen for illustration without departing from the spirit and scope of the invention.
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A method and porous multi-component material for the capture, separation or chemical reaction of a species of interest is disclosed. The porous multi-component material includes a substrate and a composite thin film. The composite thin film is formed by combining a porous polymer with a nanostructured material. The nanostructured material may include a surface chemistry for the capture of chemicals or particles. The composite thin film is coupled to the support or device surface. The method and material provides a simple, fast, and chemically and physically benign way to integrate nanostructured materials into devices while preserving their chemical activity.
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FIELD OF THE INVENTION
This invention relates to an accessory part of an engine for vehicles such as passenger cars, lorries, etc., and more particularly it relates to an oil extractor which can be screwed into the drain port of the oil pan in the engine.
BACKGROUND OF THE INVENTION
Generally, for keeping proper function of an engine for vehicles, there is a need to change the lubricating oil periodically or non-periodically. For this purpose, usually a drain port is provided in the oil pan of the engine and such drain port is closed by a plug. However, according to such type of drain plug, if the plug is inadvertently removed when changing the lubricating oil, the lubricating oil in the oil pan may spill or scatter away to soil the worker's clothes or the floor of the workshop. Also, repeated use (fitting and removal) of such drain plug may result in a loose fit, and careless fixing of such plug may cause imperfect sealing to give rise to dangerous leaking of the lubricating oil.
For overcoming such problem, it has been attempted to adapt a shut-off valve at the drain port, but such attempt has practically ended in failure because mere incorporation of such a shut-off valve could not eliminate the risk of a chance opening of the valve by vibration of the vehicle.
Therefore, a change of the lubricating oil is usually practiced by inserting into the oil pan an end of an oil hose connected to a manually operatable oil pump. It is however difficult for the ordinary household to be equipped with such an oil pump, so that the oil change is usually practiced as a commercial deal at a filling station or a repair shop. This, however, involves some serious problems such as fairly high cost of oil change at such places and impracticality for a resident at a backcountry to go all the way to a repair shop for the only purpose of an oil change.
SUMMARY OF THE INVENTION
The primary object of this invention is to provide an oil extractor of a shut-off valve type that can be screwed into the drain port of the oil pan.
Another object of this invention is to provide an oil extractor of such a type which can be securely locked in the closed position so that it cannot be inadvertently opened by mechanical vibration of the vehicle and which, when so desired for an oil change or for other purposes, can be opened manually with no need to use any specific tool therefore.
Still another object of this invention is to provide an oil extractor of the described type which can be supplied at a cost almost equal to or even lower than the charge for labor (for oil change) at the repair shop or such.
According to the present invention, these objects can be accomplished by an oil extractor for vehicle engines or the like comprising a base block whose inlet portion can be screwed into the oil pan of the vehicle engine and which is formed with an L-shaped opening in the peripheral surface of the bushing portion, a spindle rotatably positioned in said bushing portion with an end of the spindle being engaged with the valve body housed in the base block, a compression spring disposed in the bushing portion, and a manually operated handle having its inner end portion slidably engaged with the square stem portion of the spindle and placed under the action of the compression spring and also having its outer end portion passing through the opening to extend outside of the bushing portion, wherein the manually operated handle is usually locked in the inoperative position formed at a part of the opening by the compression spring. According to such an oil extractor, it is possible to extract the used lubricating oil and replace it with fresh oil by merely setting the manual handle to the open position. This allows even the ordinary vehicle operator to perform an oil change alone with ease.
Also, according to the oil extractor of this invention, since the valve body is usually locked in the closed position, there is no likelihood of inadvertent opening of the extractor due to vibration of the vehicle or impact applied to the vehicle body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of an oil extractor for vehicle engines or the like according to the present invention, the extractor being here shown in its open position;
FIG. 2 is a similar view of the oil extractor as it is shown in its closed position; and
FIG. 3 is an exploded perspective view of the same oil extractor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, there is shown in section a preferred embodiment of an oil extractor for vehicle engines according to the present invention. This oil extractor comprises a base block 3 formed with an inlet port 1 and an outlet port 2. The base block 3 is cast from a metal such as brass, and its plug portion has an external thread 4 for threaded engagement with the oil pan P of a vehicle engine. Formed in the base block 3 is a cylindrical valve chamber 5 in which is positioned a valve body 6, embodied herein as a spherical valve, which is secured liquid-tightly by an annular seal 8 positioned on the seat surface 7 of the base block 3 and another a annular seal 10 supported by a retainer 9 as further described later. The valve body 6, formed with a passage 11 connected to the inlet port 1 and outlet port 2 is, inserted into the base block 3 from the outlet port 2 of a large diameter and is secured in position by the thick circular retainer 9. The retainer 9 has formed centrally therein a hole 12 that can be communicated with the passage 11, and the space between the peripheral surface of the retainer and the outlet port 2 is sealed by an O-ring 14 fitted in an annular groove 13. The retainer 9 is also withheld against removal from the base block 3 by a C-shaped stopper ring 16 which can be elastically fitted in an annular groove 15 formed in the inner peripheral surface of the base block 3.
Said base block 3 has at its upper part a cylindrical bushing portion 17 which has formed therein a circular-sectioned stepped shaft hole 18 in communication with the valve chamber 5 and a spring housing 19. Positioned in the shaft hole 18 is a columnar spindle 20 which has at its lower end a protuberance 21 engaged in a slot 22 formed in the upper surface of the valve body 6. Thus, when the spindle 20 and the valve body 6 are assembled in position, the valve body 6 can be rotated integrally with the spindle 20.
The space formed between the shaft hole 18 and the peripheral surface of the spindle 20 is sealed by a seal ring 23 positioned in an annular groove provided in the peripheral surface of the spindle 20. The spindle 20 has a square stem portion 24 which extends into spring housing 19, and as best shown in FIG. 3, an L-shaped opening 25 is formed in that part of the peripheral surface of the bushing 17 which corresponds adjacent to the square stem portion 24. The opening 25 composes a guide portion 25a having the circular measure of approximately 120° and a locking portion 25b formed at an end of the guide portion 25a extending downwardly axially relative to the portion 25a. Passing through the opening 25 is a neck portion 26a of a manually operated handle 26 which has its proximal end portion axially slidably engaged with the square stem portion 24. The manual handle 26 includes a disc-shaped proximal end portion 26b having a square hole 27 centrally formed therein with a configuration corresponding to the sectional shape of the square stem portion 24, a substantially flat neck portion 26a positioned in the opening 25, and a grip portion 26c extending outside of the bushing portion 17 and inclined relative to disc end portion 26b.
Positioned in the spring housing 19 is a compression spring 28 having one end pressed against the surface of the proximal end portion 26b of the manual handle 26. Also positioned in the space encompassed by the compression spring 28 is a columnar insert 29 adapted to prevent removal of the spindle 20 and the manual handle 26 and spaced to constantly maintain the projection 21 in engagement in the slot 22 of the valve body 6. The insert 29 is prevented against removal from the bushing portion 17 by a disc 30 adapted to receive the other end of the compression spring 28. The disc 30 is secured to the bushing portion 17 by a C-shaped stop ring 32 elastically engaged in an annular groove 31 on the inner peripheral surface of the bushing portion 17.
The oil extractor for vehicle engines according to the present invention has the above-described structural setup, so that assembling of this oil extractor can be accomplished in the following way. First, the O-ring 14 is set in the annular groove 13 in the base block 3, then the valve body 6 and retainer 9 are slided down into the base block 3 from the outlet port 2, and then the stopper ring 16 is fitted in the annular groove 15. Thereafter, by adjusting the protuberance 21 with the slot 22 in the valve body 6, the spindle 20 is positioned in the shaft hole 18 from the spring housing 19 while the proximal end portion 26a of the manual handle 16 is positioned in the bushing portion 17 by passing it through the opening 25 in the base block 3, with the square stem portion 24 of said spindle 20 being fitted in the corresponding square hole 27. Then, the compression spring 28 and insert 29 are positioned in the spring housing 19 in the bushing portion 17, and after pressingly engaging the outer ends of the compression spring 28 and insert 29 against the disc 30, the stop ring 32 is secured in the annular groove 31, this completing the assembling of an oil extractor of this invention.
In the oil extractor of this invention, the manual handle 26 is pushed in a given downward direction by the compression spring 28, so that the disc end portion 26b is pressed downwardly stabilizing against widened annular shoulder 17a in the shaft bore 18 and the neck portion 26a of the handle 26 is normally positioned in the locking portion 25b of the opening 25. Therefore, even if mechanical vibration or impact is applied to the oil extractor, the valve body 6 maintains its closed position shown in FIG. 2, so that there is no possibility that the oil extractor be opened by chance to cause a leak of the lubricating oil in the oil pan. When performing an oil change, the manual handle 26 is slightly raised up against the force of the compression spring 28 to move the handle 26 out of the locking portion 25b of the opening 25 and then the handle is turned about 90° along the guide portion 25a of the opening 25 to keep the valve body 6 at its open position as shown in FIG. 1.
As apparent from the foregoing description, according to the present invention, it is possible for anyone to perform oil change by merely operating the manual handle. Also, the oil extractor of this invention, when not used, can not be opened inadvertently, and further, it can be manufactured at low cost.
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This invention relates to a shut-off valve type oil extractor that can be screwed into an oil pan in a vehicle engine or the like, and more particularly it relates to an oil extractor of the said type which is characterized particularly in that it is locked in a shut-off state so that it won't be inadvertently opened by mechanical vibration caused during running of the vehicle.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The application is a divisional application related to non-provisional patent application Ser. No. 10/383,037 filed on Mar. 6, 2003 now U.S. Pat. No. 6,765,140, that in turn claims priority of provisional patent application Ser. No. 60/372,494 that was filed on Apr. 12, 2002.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for carrying percussion musical instruments, particularly drums of various kinds, and more particularly, to an a carrier hardware providing an attachment structure for the tension members of percussion instruments and to a vibration isolation system for supporting the carrier on a person while standing, walking, or marching.
The prior art discloses many examples of apparatus for supporting percussion instruments such as drums, but none providing the combination of features disclosed and claimed herein. Structures for carrying percussion musical instruments must provide a balance between the comfort of the person walking, standing, or marching while wearing the instruments, and the mounting of the instruments in a desired playing position. Where the instruments are rigidly maintained at a particular playing position, the straps or structure associated with the carrier can cause painful discomfort to the marcher. Thus it is important to provide an instrument carrier with an apparatus which maintains the playing instruments in a given playing position while at the same time providing an increased measure of player comfort. Additionally, the manner in which the instruments are mounted to the carrier is of great importance. The mounting should not affect the musical characteristics of the instruments nor position them in such a manner that the person carrying them cannot properly play the instruments. In the past, marching tom drums, for example, generally were mounted to support structures by drilling openings in the drum shell and making the interconnection to the support through the shell. I believe the breech of shell integrity may affect the sound characteristics of the drum. Even if that is not the case, however, attachments through the shell make it difficult to mount and/or remove the drum from the support structure.
U.S. Pat. No. 3,106,123 to Johannsen discloses a holder for a single marching drum which clasps adjacent vertical drum rod members and is attached to the drum through those members. The holder is further secured to a pair of shoulder straps and a bracing strap configured to rest on the chest or stomach of a person wearing the holder.
U.S. Pat. No. 4,256,007 to Streit discloses a percussion instrument carrier for securing a single percussion instrument in a playing position while being carried by a person standing, walking, or marching. The single percussion instrument is secured in place to a structure worn on the person by a flexible tie-down cord and a number of L-clamps affixed at opposite corners of the instrument.
U.S. Pat. No. 6,329,583 to May discloses a carrier for percussion instruments comprising a supporting vest of composite material, rigid removable shoulder straps of light metal, and a back bar of light metal such as aluminum or magnesium. The percussion instruments are supported on a pair of J-bars mounted on the carrier in an adjustable manner. The shoulder straps specifically are intended for removal for the substitution of straps of different sizes. The straps are secured with adjustable connections permitting removal, replacement, longitudinal, and angular adjustment for comfort.
Accordingly, there is a need for a wearable carrier for percussion musical instruments which provides an adjustable attachment structure for detachably positioning a number of musical instruments in proper playing locations, and for providing a vibration attenuating supporting structure.
BRIEF SUMMARY OF THE INVENTION
Briefly stated, the percussion musical instrument carrier and vibration isolation support assembly of the present invention provides a person with an apparatus by which a plurality of percussion musical instruments such as marching tom drums may be supported on the person while standing, walking, or marching. Each of the percussion musical instruments is detachably secured between upper and lower plates of an instrument support utilizing the casings of one or more tension elements located about the circumference of each instrument. The support frame, in turn, is secured to a supporting vest having vibration isolated shoulder straps adapted to be worn by the person.
The foregoing and other objects, features, and advantages of the invention as well as presently preferred embodiments thereof will become more apparent from the reading of the following description in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In the accompanying drawings which form part of the specification:
FIG. 1 is a front perspective view of the drum carrier and vibration isolation support system of the present invention;
FIG. 2 is a front view of the drum carrier and vibration isolation support system of the present invention;
FIG. 3 is a side perspective view of the drum carrier and vibration isolation support system of the present invention;
FIG. 4 is a rear view of the drum carrier of the present invention supporting a plurality of drums;
FIG. 5 is a top view of the drum carrier of the present invention shown in FIG. 4 ;
FIG. 6 is a enlarged perspective view of the vibration isolation components of the present invention;
FIG. 7 is a side view of a percussion musical instrument showing the installation the tension lug bushing; and
FIG. 8 is a perspective view of the bushing.
Corresponding reference numerals indicate corresponding parts throughout the several figures of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following detailed description illustrates the invention by way of example and not by way of limitation. The description clearly enables one skilled in the art to make and use the invention, describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.
Referring to FIGS. 1 and 2 , a shoulder supported percussion musical instrument carrier and vibration isolation support system of the present invention is shown generally at 10 . The carrier comprises a belly-plate or vest portion 12 adapted to fit the torso of a wearer, a pair of shoulder straps 14 , each secured to the vest portion 12 at a first end, and a back bar 16 linking the opposite ends of the shoulder straps 14 together. A pair of support rod receptacles 18 are secured to the front surface of the vest portion 12 by bolts or rivets 19 . Support rods 20 , preferably J-rods, are supported in the receptacles 18 and secured in position by set screws 21 . Each J-rod 20 may be adjusted vertically and rotationally within the support rod receptacle 18 , providing vertical movement for height adjustment, and rotational movement in a horizontal plane for altering the spacing between the opposite ends of the J-rods 20 . A percussion instrument support frame 22 is secured to the J-rods 20 , opposite the front surface of the vest portion 12 .
Each of the shoulder straps 14 is secured to the vest portion 12 with a vibration attenuating element 24 to provide vibration isolation between the vest portion 12 upon which the percussion instruments are carried, and the shoulder straps 14 . The vibration attenuating element 24 , shown in FIG. 6 , is preferably composed of a rubber or similar material having vibration isolating or attenuating properties interposed between the vest portion 12 and each shoulder strap 14 . A bolt or rivet 25 integral with, or passing through, the vibration attenuating element 24 secures the respective shoulder strap 14 to the vest portion 12 . Those of ordinary skill in the art will recognize that a wide variety of materials having vibration isolating properties may be utilized as the vibration attenuating elements 24 . Correspondingly, the bolt or rivet 25 may be replaced by other conventional connectors to secure each shoulder strap 14 to the vest portion 12 .
The percussion instrument support frame 22 comprises an upper instrument support plate 30 and a lower instrument support plate 32 , secured in a predetermined spaced relationship by a pair of C-brackets 34 . In the embodiment shown in FIGS. 1 and 2 , the upper instrument support plate 30 is secured to the upper extensions of each of the C-brackets 34 by bolts or rivets 35 . Correspondingly, the lower instrument support plate 32 is secured to the lower extensions of each of the C-brackets 34 by bolts or rivets 36 . One or more support rods 38 are secured between the upper instrument support plate 30 and the lower instrument support plate 32 , to increase the stability thereof, and to facilitating maintaining the spaced relationship.
To secure the percussion instrument support frame 22 to the J-rods 20 , each of the C-brackets 34 includes a rod receiver 40 . Each C-bracket 34 is a mirror image of the other, and accordingly, the following description will describe only one C-bracket 34 . Corresponding reference numerals in the figures identify corresponding components on each C-bracket.
The rod receiver 40 comprises a section of tube 42 having an inner diameter sized to receive an end of the J-rod 20 in a friction fit. The tube 42 is secured to the C-bracket 34 by an adjustable bolt 44 passing diametrically through the tube 42 adjacent an upper end 43 . The orientation of the longitudinal axis of tube 42 may be adjusted parallel to the face of the C-bracket 34 by pivoting the tube 42 about the adjustable bolt 44 , thereby permitting the percussion instrument support frame 22 to be orientated at an angle relative to either the ground or the J-rod 20 . A stop 46 is secured to the C-bracket to provide for perpendicular alignment between the planes defined by the upper and lower instrument support plates 30 , 32 and the longitudinal axis of tube 42 .
During use, the upturned end of each J-rod 20 is seated within a corresponding rod receiver 40 from the lower end of each tube 42 . The percussion instrument support frame 22 is oriented at a desired angle relative to the J-rods 20 , by pivoting each tube 42 about the adjustable bolts 44 . Once the desired angle is achieved, the adjustable bolts 44 are tightened to secure each tube 42 in a fixed relationship to the C-bracket 34 on which it is mounted.
Turning to FIG. 3 through FIG. 5 , there is shown one or more percussion musical instruments 100 secured to the percussion instrument support frame 22 . Each percussion musical instrument 100 includes a cylindrical body or shell 102 and a drum head 104 stretched over the upper end of the shell 102 . The drum head 104 is secured to the shell 102 by a rim 106 which bears on the upper edge of the shell 102 . A plurality of equidistantly spaced tension lugs 108 extend through the rim 106 and are threaded into casings 110 fastened to the side of the shell 102 . Each casing 110 has a predetermined length L, and an axially disposed threaded bore 112 , open at each end, into which a tension lug 108 is threaded.
Referring to FIG. 1 , it is shown that the upper and lower instrument support plates 30 , 32 each include, along corresponding peripheral edges 114 , a plurality of vertically aligned curved recesses 116 . Each curved recess 116 has a radius and a radial dimension. The radial dimension corresponding to an outer radial dimension of a percussion musical instrument 100 intended for attachment at that location. Further shown in FIG. 1 are a plurality of vertically aligned instrument attachment points 120 , preferably bolt receiving bores, adjacent each curved recess 116 , and spaced about each curved recess 116 in positions corresponding to the placement of casings 110 about the shell 102 of a percussion musical instrument 100 intended for attachment at that location.
The predetermined spaced relationship between the upper and lower instrument support plates 30 , 32 , as defined by the dimension of the C-brackets 34 , is greater than the predetermined length L of the casings 110 on the percussion musical instruments 100 intended for attachment to the percussion instrument support frame 22 . To secure a percussion musical instrument 100 to the support frame 22 , one or more of the tension lugs 108 are removed from the rim 106 and casings 110 . The percussion musical instrument 100 is then positioned within a curved recess 116 in the upper and lower instrument support plates 30 , 32 , such that the peripheral edges 114 of the support plates 30 , 32 abut the shell 102 . Next, the percussion musical instrument 100 is rotated to bring the threaded bore 112 of at least one casing 110 from which the tension lug 108 has been removed into alignment between the upper and lower support plates 30 , 32 with a vertically aligned pair of bolt receiving bores 120 . The tension lug 108 is then replaced through the rim 106 , passing through a bolt receiving bore 120 in the upper support plate 30 , and threaded into the threaded bore 112 of the casing 110 .
During installation of the tension lug 108 , one vibration isolation washer 123 is installed above the casing 110 and one vibration isolation washer 123 is installed below the casing 110 . While the two vibration isolation washers may be made from any resilient material, it is preferred that the vibration isolation washers 123 be made from neoprene material. A bushing 124 ( FIGS. 7 and 8 ) are placed into the opening within the rims 106 prior to installation of the tension lugs 108 . The bushing 124 reduces the friction between the tension lugs 108 and the rim 106 to provide a finer ability to adjust the tension in the tension lug 108 . Additionally, the bushings 124 act to keep the vertical axial tension loads perpendicular to the upper surface of the rim 106 , thereby greatly reducing the tendency to create a bending moment in the tension lug 108 as the tension lug is tightened. While the bushing 124 made be made of any material which reduces the friction coefficient between the metal of the rim 106 and the tension rod 108 , it is preferred that the bushing be made from a brass material. It will also be appreciated that while the bushing 124 is part of the drum carrier 10 , the bushing may also be used on any drum percussion instrument having a rim 106 used for tightening a drum head 104 onto a drum shell 102 .
A retaining bolt 122 is correspondingly passed upward through a bolt receiving bore 120 in the lower support plate 32 and threaded into the threaded bore 112 of the casing 110 , opposite the tension lug 108 . Preferably, at least two casings are secured between the upper and lower support plates 30 , 32 in this manner for each percussion musical instrument 100 .
In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results are obtained. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
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A shoulder supported percussion musical instrument carrier and vibration isolation support assembly providing support for a plurality of percussion musical instruments on a person while standing, walking, or marching. Each of the percussion musical instruments is detachably secured between upper and lower plates of an instrument support frame utilizing one or more tension element casings located about the circumference of each instrument. The instrument support frame, in turn, is secured to a supporting vest including vibration isolated shoulder straps. A special bushing is used in conjunction with the tension lugs of the percussion instrument to reduce friction coefficient and to maintain the alignment of the tension lugs.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of co-pending U.S. patent application Ser. No. 15/152,611, filed 12 May 2016, which is a continuation of abandoned U.S. patent application Ser. No. 14/099,941, filed on 7 Dec. 2013, which is a continuation of expired patent application PCT/EP2012/060739, filed on 6 Jun. 2012, which claims priority to European Patent Application No. 11450072.1, filed on 8 Jun. 2011, the disclosures of these related applications are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to methods and devices including cable holding elements, and particularly to cable holding elements used in kiosk-style machines.
BACKGROUND OF THE INVENTION
[0003] Cable guides for gaming machines are known in the current state of technology, whereby cable strands are held together with cable ties or cable spirals. The cable strands are connected to the housing of the device by retaining plates or clips.
[0004] A disadvantage of known cable guides is that disconnecting and re-connecting cable strands within gaming machine housings is difficult because manipulating cable ties and spirals often requires more space than is available in such housings.
[0005] What is desired is a cable holding element in which the cable strands can be readily installed, connected, and removed again.
[0006] Security is another disadvantage of the current state of technology. In gaming machines, generic fixed cable harness arrangements inside the housing of a device do fix individual cables in predictable positions. With knowledge of the position of the cable, unauthorized manipulation from outside the case is possible. A hacker can drill into the case at a suitable position to access particular cables. If a person manipulating the device knows the respective position where a cable or cable strand runs, there is a danger of this person manipulating a plurality of other devices this way.
[0007] A further goal of the invention is improved device security.
SUMMARY OF THE INVENTION
[0008] The present invention provides for a cable holding device (element) adapted for use within a casino-style gaming machine, for the accommodation of one or more cables. The cable holding device includes a base body as well as a number of latching projections projecting from the base body. The latching projections extend in rows that oppose each other, whereby the latching projections and base body cooperate to define a channel area for guiding the cables. The base body is L-shaped, W-shaped, or has another shape effective at defining at least one channel area.
[0009] The latching projections are configured to have ends that interlock without contact, such as in a comb-like manner. The ends of a first row of latching projections oppose and extend between the ends of a second row of latching projections to define the channel area. The latching projections are flexible to enable insertion and removal of a cable into, and out from, the channel area.
[0010] The latching projections are flexible to a quick change of cable from the cable holding device with relatively little effort. Further individual cable strands may be exchanged.
[0011] Thus quickly or with relatively little effort a configuration or modification of the cable route of one or several cables can be achieved, whereby the cable strands are removed from the cable holding elements inside the housing of the device and are laid in other cable holding elements in the same case. Thus it is possible to remedy manipulation very easily because the cable holding elements allow a plurality of possible configurations and thereby cable strands can be laid in a more or less random position in a device. Hereby a targeted manipulation of the device is made difficult.
[0012] In addition, the invention offers the advantage that an easy and flexible installation of multiple cables and cable strands in a device housing of the same electronic device is possible. A particular advantage is given by exchanging cables, such as while exchanging wired components of the device, whereby individual cables can be very easily removed from the cable holding elements through the latching projections.
[0013] The cable holding element or the cable channel does not require any separate closing or locking elements, such as closing clips, through which a simple operation is allowed and the installation time is reduced.
[0014] A particular aspect of the invention foresees that the latching projections confining the channel area are L-shaped, which latching projections are at a distance opposite each other, so that the channel area features a closed and/or U-shaped channel cross-section. This advantageous embodiment of the latching projections or of the channel cross-section allows the simple laying or removal of the cable strand, or the cables, into the channel area or out of the channel area.
[0015] Furthermore, it can be provided that in the longitudinal direction of the channel area the latching projections are arranged in such a manner, so that these, preferably without contact, interlock in a comb-like manner, so that the end of at least one latching projection is arranged and/or protrudes between two respectively opposite latching projections. Thereby the unintentional falling out of the cables or cable strands, caused for example by shaking, from the cable channel is prevented.
[0016] It can be further provided that the latching projections are constructed to be elastically bendable respectively to be resilient, so that these can be swinging against the base body of the cable holding element and after the swinging return to their initial position. Hereby the laying of cables into the cable channel is facilitated, whereby a cable can be pressed through the intermediate area between two latching projections.
[0017] A particularly advantageous embodiment of the latching projections, which prevent shifting or sliding of the cable strands from the cable channel, foresees that the latching projections are developed in a curved shape, in particular in an angled-hook shape, and feature two latching projection sections, whereby the first latching projection section projects in an angle of 70°-90°, preferably 85°-90°, in particular, exactly vertically and/or normally, from the respective area and whereby the second latching projection section continues at the distant end of the respective area of the first latching projection section and projects in an angle, in particular with an angle between 70° to 110°, preferably 90°, to the first latching projection section in direction towards the latching projections, which project from the respective areas opposite each other.
[0018] A constructively particular simple embodiment of the latching projections foresees that the two latching projection sections are developed integrally, in particular developed from a flat body and/or a profile rod, that features an arc between the first and the second latching projection section.
[0019] So as to facilitate the penetration of the cable strands into the cable channel of the cable holding element it can be foreseen that the two latching projection sections enclose an angle of less than or equal to 90°.
[0020] So as to enable a particular simple cable conduit and enable a development of longer cable holding elements with a longer extension in cable direction it can be foreseen that the two areas of which the latching projections project run parallel to another and/or lie at one level.
[0021] So as to achieve a balanced pressure of the base body of the cable channel when inserting the cables or cable strands or the removal of the cables or cable strands and to achieve a simple constructive embodiment of the cable channel it can be foreseen that the respective number of latching projections, which project from both areas, deviate by no more than one from another.
[0022] So as to facilitate the positioning of the cable strands into the cable channel or the cable holding element it can be foreseen that the ends of the latching projections or the ends of the second latching projection sections are inclined towards the base body.
[0023] So as to prevent an unintentional shifting or sliding of the cable strands or cables, in particular by vibrations, it can be foreseen that for each latching projection, of which the end is arranged between two latching projections projecting from the respective area opposite each other, another projecting latching projection from the opposite area is foreseen, of which the end is approximated to the end of the respective latching projection and is opposite, whereby, in particular, the front sides of the ends of the other latching projection and the latching projection are opposite each other.
[0024] So as to achieve a constructively simple embodiment of such a cable channel it can be foreseen that the other latching projections have each a first latching projection section, that projects from the base body in an angle, in particular an angle of 70° to 110°, preferably 90°, and feature a second latching projection section that continues the first latching projection section and projects from the first latching projection section.
[0025] A simplification of the constructive development foresees that the form and/or the alignment of the first and/or second latching projection section of the other latching projections corresponds to the form and alignment of the first and/or second latching projection sections of the latching projections.
[0026] A further added or alternative simplification of the construction foresees that the length of the first latching projection section of the other latching projections corresponds to the length of the first latching projection section of the latching projections.
[0027] A further simplification of the structure of the cable holding element according to the invention foresees that the latching projections projecting from the first area and/or the second area are developed and/or arranged equally, and/or that all latching projections are designed equally.
[0028] For the same purpose it can be additionally or alternatively foreseen that the other latching projections projecting from the first area and/or from the second area are constructed and/or aligned equally, and that all other latching projections are developed equally.
[0029] For the development of longer cable holding elements, which have a longer longitudinal extension in direction of the cable it can be foreseen that latching projections project from two areas, whereby a number of first latching projections project from the first of the two areas and a number of the second latching projections project from the second of the two areas.
[0030] For the prevention of shifting and sliding of cables or cable strands from the cable channel it can be foreseen that the first latching projections project from subareas of the first area, which lie on a first straight line and/or that the second latching projections project from subareas of the second area, which lie on a second straight line, whereby the first straight line and the second straight line are preferably arranged in a parallel manner to each other.
[0031] Additionally or alternatively, for the same purpose it can be foreseen that a number of the other latching projections and/or from subareas of the second area project, which lie on the first straight line, and the remaining of the other latching projections project from subareas of the second area, which lie on the second straight line.
[0032] So as to obtain a space-saving construction, which prevents a twisting or jamming of cables, which are placed outside the cable holding element, it can be foreseen that between each two latching projections a respective further latching projection is arranged.
[0033] Thereby it can be particularly foreseen that the second latching projection section of the latching projections, if applicable, also the second latching projection sections of the other latching projections, lie at the same level.
[0034] For the reduction of material requirements of the base body it can be foreseen that the base body has at least one recess in the areas opposite the latching projections.
[0035] For the stabilisation of the latching projections as well as the prevention of a breaking-off of the latching projection when inserting and extracting cable strands or cables, it can be foreseen that the base body features at least one, in particular two, in particular vertically and/or normally, projecting projections from it, of which the individual latching projections and, if applicable, the other latching projections project.
[0036] For a simplified guiding of the cables it can be foreseen that the channel cross-section of the channel area narrows and/or extends at least in a subarea along the longitudinal extension of the channel area.
[0037] So as to achieve a simple insertion and extraction of the cables into the cable holding element or out of the cable holding element it can be foreseen that the latching projections are developed to be elastically bendable and/or to be resilient.
[0038] So as to prevent a breaking-off of the latching projection when inserting or extracting the cable strands or cables it can be foreseen that the relation of the width in longitudinal direction of the cable holding element to the thickness of the latching projections is between 4:1 to 4:1.5, in particular 4:1.3.
[0039] So as to guarantee a sufficient elastic bendability it can be in particular foreseen that the latching projections, if applicable the other latching projections and/or the entire cable holding element, are made from synthetic materials, in particular polyethylene PE and/or polypropylene PP.
[0040] Furthermore the invention relates to a cable holding arrangement comprehending a number of cable holding elements in accordance with the invention.
[0041] So as to achieve a cabling non-identifiable or non-predictable for externals it can be foreseen that the individual cable holding elements are arranged equally aligned on a common base body.
[0042] So as to achieve an easy or simple fastening of the cable holding element to a device it can be foreseen that the base body features fastening devices, in particular releasable without tools, for the fastening of the cable holding to a device, in particular with a frame of device.
[0043] In order to reduce the bill of materials cost it can be foreseen that the common base body has at least one recess in the areas opposite the latching projections.
[0044] For the fastening of a cable holding element in corner areas of a device it can be foreseen that the common base body forms a W-shaped angle profile and, in addition, latching projections of each of the cable holding elements project from the central bow edge of the W-shaped angle profile.
[0045] Hereby a particular large cable cross-section can be achieved, if projections project from the bow edge and/or the trailing edge of which the latching projections project.
[0046] A particularly advantageous adjustment in the corner areas of a right-angled device is achieved if the W-shaped angle profile in the area of the central bow edge, preferably also in both trailing edges, features a right angle.
[0047] For the fastening of a cable holding to evenly developed surfaces of the device it can be foreseen that the common base body is developed in a flat manner and/or even manner and the individual latching projections project from the same side of the base body.
[0048] In order to achieve a plurality of different cabling possibilities and thereby counteract an intentional manipulation by third parties it can be foreseen that the individual cable holding elements are arranged equally and, if applicable, are arranged side by side and/or consecutively.
[0049] For the same purpose it can be additionally or alternatively foreseen that the first and the second straight line are arranged in a parallel manner to each other.
[0050] Finally the invention refers to an electronic device, in particular a betting and gaming machine or a betting and gaming device that at least comprehends a cable holding according to invention or at least a plurality of cable holding elements according to invention. Such an electronic device has a plurality of cabling possibilities, which allow the manufacturer of the device to equip his devices with different cable positions so as to prevent a manipulation occurring always in the same manner of his betting and gaming devices.
[0051] In the following four embodiments of the invention are described in greater detail with the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] FIG. 1 shows a cable holding with a W-shaped cross-section in an angled view.
[0053] FIG. 2 shows the cable holding shown in FIG. 1 from a different perspective in an angled view.
[0054] FIG. 3 shows the cable holding shown in FIG. 1 in a lateral view.
[0055] FIG. 4 shows the cable holding shown in FIG. 1 in a lateral view from the other side.
[0056] FIG. 5 shows the cable holding shown in FIG. 1 from an above view.
[0057] FIG. 6 shows the cable holding shown in FIG. 1 from a below view.
[0058] FIG. 7 shows the cable holding shown in FIG. 1 with a view of the channel area.
[0059] FIG. 8 shows the interior of an electronic device, in the corner area of which a cable holding element, as shown in FIG. 1 , is installed.
[0060] FIG. 9 shows a second embodiment of the invention in an angled view.
[0061] FIG. 10 shows the embodiment of the invention shown in FIG. 9 from a different perspective in an angled view.
[0062] FIG. 11 shows the embodiment of the invention shown in FIG. 9 from the side.
[0063] FIG. 12 shows the embodiment of the invention shown in FIG. 9 from the opposite side.
[0064] FIG. 13 shows the embodiment of the invention shown in FIG. 9 with a view of the channel area.
[0065] FIG. 14 shows the embodiment of the invention shown in FIG. 9 from above.
[0066] FIG. 15 shows the embodiment of the invention shown in FIG. 9 from below.
[0067] FIG. 16 shows the interior of a device with a number of cable holdings installed therein, as shown in FIG. 9 .
[0068] FIG. 17 shows a third embodiment of the invention from an angled view.
[0069] FIG. 18 shows a fourth embodiment of the invention from an angled view.
DETAILED DESCRIPTION
[0070] In FIG. 1 a first embodiment according to invention of a cable holding 50 with two cable holding elements 1 and 1 ′ is shown. The cable holding elements 1 and 1 ′ feature a common base body 100 , whereby two channel areas 13 and 13 ′ divided from each other are developed. The base body 100 features a W-shaped angle profile 101 , which features a central bow edge 102 as well as two trailing edges 103 . The central bow edge 102 lies parallel to the trailing edges 103 and lies with these at the same level.
[0071] Both channel areas 13 and 13 ′ are each confined by one half of the W-shaped profile 101 as well as the projections 17 and 18 . The projections 17 and 18 project from the bow edge 102 and the trailing edges 103 . In one embodiment, the projections 17 and 18 project from the central bow edge 102 . In another embodiment, the lateral projections 17 and 18 project from one of the two respective trailing edges 103 .
[0072] These projections 17 and 18 in the present embodiment are developed normally in an upright manner to the level determined by the central bow edge 102 as well as both trailing edges 103 and are attached to the central bow edge 102 or to the trailing edges 103 to extend the edges 102 and 103 , respectively. The projections 17 and 18 extend in a profile longitudinal direction of the W-shaped profile 101 across the entire length of the profile and stand normally at the level determined by the central bow edge 102 and the trailing edge 103 .
[0073] At the respective distant end of the bow edge 102 or the respective trailing edge 103 of the respective projection 17 and 18 a surface with an area 111 and 121 is developed, from which individual projections 11 and 12 project.
[0074] The first cable holding element 1 confines the first channel area 13 . The first channel area 13 is on the distant end of the trailing edge 103 of the projection 17 and 18 . The areas on the central projections 17 and 18 are referred to as areas opposite to each other 111 and 121 . Similarly, in relation to the second cable holding element 1 ′ that confines the second channel area 13 ′, the area on the distant end of the trailing edge 103 of the projection 17 and 18 and the area on the central projection 17 and 18 are referred to as areas opposite to each other 111 and 121 .
[0075] FIG. 7 shows the latching projections 11 and 12 . The latching projections 11 and 12 each include a respective first latching projection section 113 and 123 , as well as a respective second latching projection section 114 and 123 . The latching projections 11 and 12 are developed in an L-shape or in an angled-hook shape and feature each two respective latching projection sections 113 , 114 , 123 , and 124 . Each latching projection 11 and 12 , respectively features a first latching projection section 113 and 123 and a second latching projection section 114 and 124 .
[0076] The first latching projection sections 113 and 123 stand vertically and/or normally to the areas 111 and 121 from which they project. The second latching projection sections 114 and 124 continue the first latching projections 113 and 123 at its respective distant end.
[0077] The latching projection sections 113 , 114 , 123 , 124 are developed integrally and are developed from a flat body. In the present case curved profile rods are used as latching projections 11 and 12 . These profile rods or flat bodies feature between the first and the second latching projection sections 113 , 114 , 123 , and 124 each have an arc 115 and 125 . The arcs 115 and 125 are developed in such a manner that the two latching projection sections 113 , 114 , 123 , and 124 enclose an angle of no less than 90°. Preferably, the angle is approximately 75°.
[0078] The second latching projection sections 114 and 124 project from the end of the first latching projection section in direction of the respective opposite area 111 and 121 . The individual latching projections 11 and 12 are arranged in a comb-like manner, that is they are arranged at a distance from each other and are aligned equally, whereby all latching projections 11 and 12 projecting from the same area 111 and 121 of the first cable holding element 1 and 1 ′ have the same distance to the respectively adjacently arranged latching projections 11 and 12 .
[0079] The latching projections 11 and 12 project from points and/or subareas on the areas 111 and 121 , which are each arranged on a common straight line 116 and 117 . The latching projections 11 and 12 opposite each other interlock without contact, whereby the ends 110 and 120 of the latching projections 11 and 12 or the ends 110 and 120 FIG. 2 . are approximated to the second latching projections 114 and 124 without contact.
[0080] Each end 110 and 120 of the respective latching projections 11 and 12 is arranged between two latching projections 11 and 12 of the respective opposite area 111 and 121 or protrudes into the intermediate area between two projecting latching projections 11 and 12 of the opposite area 11 and 12 . The individual ends 110 and 120 of the latching projections 11 and 12 or the second latching projection sections 114 and 124 are arranged so that these do not contact the projecting latching projections 11 and 12 of the opposite areas 111 and 121 . In the present embodiment all latching projections 11 and 12 are equally developed and aligned and do not contact each other.
[0081] On the projections 17 and 18 , which project from the central bow edge 102 , are latching elements 11 and 12 . These latching elements 11 and 12 define the first channel area 13 and the other channel area 13 ′. The side facing away from the central bow edge 102 of the central projections 17 and 18 develops thereby an area 111 and 121 from which latching projections 11 and 12 project to define of the first channel area 13 as well as for the defining of the second channel area 13 ′.
[0082] The arrangement of the latching projections 11 and 12 occurs in such a manner that the channel areas 13 and 13 ′ features a close and/or U-shaped channel cross-section.
[0083] In one embodiment of the invention, both of the two cable holding elements 1 and 1 ′ of the cable holding 50 include each four first latching projections 11 and four second latching projections 12 . The ends of the second latching projection sections 123 and 124 are inclined towards the common base body 100 or to the level determined by the trailing edges 103 as well as the central bow edge 102 .
[0084] Four fastening elements 107 are arranged in the area of the W-shaped profile 101 . The W-shaped profile facilitates a tool-free and releasable fastening of the cable holder 50 with a device 60 or with its frame 61 . This achieves the goal of simple assembly.
[0085] A preferred arrangement of the cable holder 50 shown in FIGS. 1 to 7 is shown in FIG. 8 . The device in this case includes a frame 61 and multiple wall elements, which form a device housing and encloses a device interior.
[0086] The individual edges of the W-shaped profile 101 of the cable holder 50 are aligned at a right angle to each other.
[0087] FIG. 8 . shows the cable holder 50 mounted on an angled corner profile of the frame 61 of a device 60 , whereby the individual fastening means 107 engage into the recesses on the corner profile of the frame 61 and thus allow a releasable fastening of the cable holder 50 on the frame 61 . In addition, FIG. 8 shows a cable 2 that is guided into one of the two channel areas 13 of the cable holder 50 .
[0088] The base body 10 and 100 of the cable holder 50 features a recess at the areas opposite the latching projections 11 and 12 . Furthermore, additional recesses are foreseen in which the fastening means 107 for the fastening at the frame 61 of the device 60 are located. The channel cross-section of both channel areas 13 and 13 ′ of the embodiment of the invention shown in FIGS. 1 to 7 remains the consistent across the entire longitudinal direction of the respective channel areas 13 and 13 ′.
[0089] The latching projections 11 and 12 in the present embodiment of the invention are developed to be elastically bendable and to be resilient and consist of synthetic materials such as polyethylene. The latching projections 11 and 12 have a spring effect so that the latching projections 11 and 12 may flex and return to their initial position after their deflection and swivelling in the course of the insertion of the cables 2 into the channel areas 13 and 13 ′. The consistency of the polyethylene is thereby selected in such a manner so that the latching elements have a bending stiffness and elasticity that allow a swivelling of the individual latching elements 11 and 12 so that a cable can be inserted through pressure onto the latching elements 11 and 12 in the channel areas 13 and 13 ′.
[0090] Alternatively the cable holding element 1 can also be made from polypropylene or other elastically bendable and resilient synthetic materials. In the present case not only the latching projections 11 and 12 but also the entire cable holder 50 may be developed from synthetic materials.
[0091] In FIGS. 9 to 16 a second embodiment according to invention of a cable holding 50 is shown. The second embodiment of the invention corresponds with the first embodiment of the invention with the exception of the deviations outlined below.
[0092] The common base body 100 of this cable holding 50 is developed in a flat and even manner The individual latching projections 11 and 12 are also arranged on areas 111 and 121 on projections 17 and 18 , which run in a parallel manner to the level determined by the base body 100 .
[0093] The common base body 100 features a number of fastening means 107 with which the cable holding 50 can be arranged at the frame 61 of a device 60 releasable without tools. The cable holding 50 defines two channel areas 13 and 13 ′, which are arranged in a parallel manner, and which are divided from each other by centrally arranged projections 17 and 18 . The three projections 17 and 18 of the base body 100 project from it and carry at the distant end to the base body 100 the individual latching projections. The form, shape and alignment of the individual latching projections 11 and 12 are otherwise identical to the first embodiment.
[0094] The essential difference between the first and the second embodiment of the invention is that the base body 100 of the second embodiment features a flat and even shape. The projections are directly attached to the level of the base body 100 . Due to the form of the base body 100 the cable holding 50 as shown in the second embodiment of the invention, can be preferably used for assembly at even supports.
[0095] In FIG. 16 an interior cabling of a device 60 is represented in more detail, whereby a plurality of cable holdings, as shown in the second embodiment of the invention in FIGS. 9 to 15 , is used. In contrast to the embodiments of cable holdings 50 shown in FIGS. 9 to 15 , the embodiment of FIG. 16 has cable holdings 50 having four channel areas divided from each other, and which are arranged on a common base body 10 .
[0096] The cable holdings 50 are bolted via the fastening means 107 of the base plate 10 to or with housing parts of the device 60 . Alternatively, a tool-free fastening can be foreseen, for example, the fastening means 107 may be formed by a bore, into which flexible segment sections are arranged so that a rod-shaped body inserted into the bore is fixed through the segment section in a barbed-hook manner The flexible segment section can be developed from the same material as the base plate 10 .
[0097] As is apparent from the area bearing the mark A in FIG. 16 the guiding of cables 2 , 2 ′, 2 ″, and 2 ″′ or cable harnesses in device 60 can occur in different ways. The cable holding 50 features four different channel areas 13 , whereby all of the cables 2 , 2 ′, 2 ″, and 2 ″′ only run through two of the four channel areas 13 , while the remaining channel areas 13 of the cable holding 50 are free of cables 2 . A targeted manipulation of a device 60 would however only be possible, if a person performing a manipulation knows the exact position of the individual cables 2 , 2 ′, 2 ″, and 2 ″′ and can conduct an effective interruption from outside. But if the cables 2 , 2 ′, 2 ″, and 2 ″′ are during the production always guided in a different way, then an effective manipulation is made considerably difficult. Through the simple disconnecting and relaying of cables 2 , 2 ′, 2 ″,and 2 ″′ into or out of the channel area 13 a simple new cabling is possible and a manipulation from outside of the individual cables 2 , 2 ′, 2 ″, and 2 ″′ is made more difficult.
[0098] The first as well as the second embodiment are developed symmetrically around a level which runs through the central projections 17 and 18 and stands normally at the level determined by the trailing edges.
[0099] A third embodiment of the invention of a cable holding 50 is shown in FIG. 17 and features an even and flat common base body 100 , which has four fastening means 107 for the fastening of the common base body 100 or the cable holding 50 to the frame 61 of a device 60 . On the common base body 10 there are four cable holding elements 1 , which are aligned equidistant and parallel with each other.
[0100] Each of the cable holding elements 1 features two projections 17 and 18 which project from the common base body 100 almost vertically or normally. At the end of the projections 17 and 18 distant from the base body 100 latching projections 11 and 12 as well as other latching projections 15 and 16 project. As shown in the previous embodiments the latching projections 11 and 12 comprehend each a first latching projection section 113 and 114 that essentially runs normally with an angle of 70-90°, in particular 85-90°, to the base body 10 . Arcs 115 and 125 represent the curvature of the latching projections 11 and 12 and the second latching projection sections 114 and 124 run almost parallel to the base body 10 .
[0101] The latching projection 11 and 12 project in a comb-like manner from the respective projections 17 and 18 , whereby the ends 110 and 120 of the respective latching projections 11 and 12 protrude or are aligned each between two opposite areas 111 and 121 or from the projection 17 and 18 opposite each other.
[0102] Those areas 111 and 121 of the cable holding 50 at the end of the projections 17 and 18 distant to the base body 10 run in a parallel manner and lie at the same level. As in the two previous examples the number of latching projections 11 and 12 , which project from the areas 111 and 121 , are equal.
[0103] Alternatively, it can naturally be foreseen for all embodiments of the invention that a deviation between the number of latching projection 11 , which project from the first area 111 , from the number of latching projections 12 , which project from the second area 121 , is different. It is particularly advantageous if the respective number of latching projections 11 and 12 projecting from both areas 111 and 121 preferably differ by 1. In particular, in any case a deviation no greater than 1 is possible without detriment to the functionality of the cable holding 50 .
[0104] FIG. 17 shows an embodiment of the invention where all second latching projection sections 114 and 124 lie at the same level, whereby this level runs parallel to the level of the base body 10 .
[0105] For each latching projections 11 and 12 , of which the end is arranged between two latching projections 11 and 12 of the respective opposite areas 111 and 121 , other projecting latching projections 15 and 16 are foreseen, upon which, the ends 151 and 161 are approximated to the end of the respective latching projections 11 and 12 and lies opposite. In the present embodiment also the other latching projections 15 , 16 lie at the same level, which runs parallel to the base body 10 , in which also the second latching projections 123 and 124 lie. The front sides of the ends 110 , 120 151 , and 161 of the latching projections 11 and 12 and the other latching projections 15 and 16 lie opposite each other.
[0106] The other latching projections 15 and 16 feature a first latching projection section 151 and 161 that projects from the base body 10 or the projection 17 and 18 of the base body 10 essentially normally at an angle of 70°-90°, in particular 85°-90°. The second latching projections 152 and 162 , of the other latching projections 15 and 16 , extends the first latching projection section 151 and 161 at its end distant to the base body 10 . The other latching projections 15 and 16 feature an arc 153 and 163 , that connects the respective first and second latching projection sections 151 , 152 , 161 , and 162 , whereby the first and the second latching projection sections 151 , 152 , 161 , and 162 are in an almost right angle to each other. The form and alignment of the first and/or second latching projection sections 151 , 152 , 161 , and 162 of the other latching projections 15 and 16 corresponds to the form and alignment of the first and second latching projection sections 113 , 114 , 123 , and 124 of the latching projections 11 and 12 .
[0107] The length of the first latching projection sections 151 and 161 of the other latching projections 15 and 16 thereby corresponds to the length of the first latching projection sections 113 and 123 of the latching projections 11 and 12 . The form and alignment of the first and second latching projection sections 151 , 152 , 161 , 162 of the other latching projections 15 and 16 correspond to the form and alignment of the first and/or second latching projection sections 113 , 114 , 123 , 124 of the latching projections 11 and 12 . The other latching projections 15 and 16 and the latching projections 11 and 12 are constructed equally and aligned equally.
[0108] As with both previous embodiments, each cable holding element 1 features areas 111 and 121 on the projections 17 and 18 , respectively. The latching projections 11 and 12 extend and project from the areas 111 and 121 . Those parts of the areas 111 and 121 from which the latching projections project lie each on a straight line 116 , 117 . Each cable holding element 1 of the cable holding 50 shown in FIG. 17 features two projections 17 and 18 .
[0109] On the first of the two projections 17 a first area 111 is foreseen on which a number of first latching projections 11 project in direction of the second opposite projection 18 . Similarly, on the second projection 18 a second area 121 is foreseen from which a number of the second latching projections 12 project in direction of the first projection 17 . All first latching projections 11 project from subareas of the first area 111 , which lie on the first straight line 116 . All of the second latching projection 12 project from subareas of the second area 121 of the second projection 18 , which lie on the second straight line 126 .
[0110] All first straight lines 116 and second straight lines 126 of the cable holding elements 1 of the cable holding 50 in FIG. 17 lie in a parallel manner to each other.
[0111] Also the other latching projections 15 , 16 project each from subareas of the first and second area 111 and 121 , which lie on the respective first of second straight line 116 and 126 . A number of the other latching projections 15 and 16 , hereinafter called the first other latching projections 15 , project from subareas of the first area 111 , which lie on the first straight line 116 . The remaining other latching projections, hereinafter called the second other latching projections 16 , project from subareas of the second area 121 , which lie on the second straight line 126 . Between two latching projections 11 and 12 , which lie adjacently on one area 111 and 121 a respective other latching projection 15 , 16 is arranged. The second latching projection sections 114 and 124 of the latching projections 11 and 12 and the second latching projection sections 152 and 162 of the other latching projections 15 and 16 lie at the same level.
[0112] The individual latching projection sections 113 , 114 , 123 , and 124 are developed integrally from a flat body or a profile rod, which has between the first and the second latching projection section 113 , 114 , 123 , and 124 an arc 115 , 125 . The latching projections 11 and 12 are developed to be elastically bendable and to be resilient, whereby the relation of the width in longitudinal direction of the channel or the cable holding element 1 to the thickness of the latching projections 11 and 12 is between 4:1 to 4:1.5, in the present embodiment the preferable value is 4:1.3.
[0113] The entire cable holding 50 consists in the present embodiment of polyethylene. The consistency of the polyethylene is thereby selected in such a manner so that the latching elements have a bending stiffness and elasticity that allow a swivelling of the individual latching elements 11 and 12 , so that a cable can be inserted through pressure onto the latching elements 11 and 12 in the channel area 13 and 13 ′. In addition, in this particular embodiment of the invention the entire cable holding 50 is developed integrally.
[0114] Alternatively, the cable holding 50 shown in FIG. 17 can also be made from polypropylene or other synthetic materials that have a similar consistency or material property, in particular elasticity and bending stiffness.
[0115] Another fourth embodiment of the invention shown in FIG. 18 refers to a single cable holding element 1 with a base body 10 . The cable holding element 1 and 1 ′ develops a divided channel area 13 . The base body 10 is developed in a plate-shaped manner with a base plate where at the trailing edges 103 , the projections 17 , 18 project.
[0116] These projections 17 and 18 are in the present embodiment developed normally in an upright manner to the level determined by the base plate and are attached to the central bow edge 102 or to the trailing edges 103 and continue these. The projections 17 and 18 extend in profile longitudinal direction across the entire length of the cable holding element 1 and stand normally at the level determined by the trailing edges 103 .
[0117] At the respective end, distant to the respective trailing edge 103 , of the respective projection 17 and 18 a surface with an area 111 and 121 is developed, from which individual latching projections 11 and 12 project.
[0118] In relation to the first cable holding element 1 , which confines the first channel area 13 , the areas 111 and 121 on the distant end of the trailing edge 103 of the projection 17 and 18 and the area on the central projection 17 and 18 are referred to as areas opposite to each other 111 and 121 .
[0119] In the present embodiment the latching projections 11 and 12 —as well as with the remaining embodiments—comprehend each a first latching projection section 113 and 123 as well as a second latching projection section 114 and 124 . The latching projections 11 and 12 are developed in an L-shaped or in an angled-hook shape manner and feature each two respective latching projection sections 113 , 114 , 123 , and 124 . Each latching projection 11 and 12 features a first latching projection section 113 and 123 and a second latching projection section 114 and 124 . The first latching projection sections 113 and 123 stand vertically i.e. normally to the areas 111 and 121 from which they project. The second latching projection section 114 and 124 continues the first latching projection 113 and 123 at its distant end of its respective area 111 and 121 .
[0120] The latching projection sections 113 , 114 , 123 , and 124 are developed integrally and are developed from a flat body. In the present case curved profile rods are used as latching projections 11 and 12 . These profile rods or flat bodies feature between the first and the second latching projection section 113 , 114 , 123 and 124 each an angle section or an arc 115 , 125 . This arc 115 , 125 can be developed in such a manner that the two latching projection sections 113 , 114 , 123 and 124 enclose an angle of no less than 90°, in the present case approximately 75°.
[0121] The second latching projection sections 123 and 124 project from the end of the first latching projection section in direction of the respective opposite area 111 and 121 . The individual latching projections 11 and 12 are arranged in a comb-like manner, that is they are arranged at a distance from each other and are aligned equally, whereby latching projections 11 and 12 projecting all from the same area 111 and 121 of the first cable holding element 1 and 1 ′ have each the same distance to the respectively adjacently arranged latching projections 11 and 12 .
[0122] The latching projections 11 and 12 project from point on the areas 111 and 121 , which each latching projection 11 and 12 are arranged on a common straight line 116 and 117 , respectively. The latching projections 11 and 12 opposite each other interlock without contact, whereby the ends 110 , 120 of the latching projections 11 and 122 or the ends 110 and 120 of the second latching projection section 114 and 124 are approximated to each other without contact.
[0123] Each end 110 and 120 of the respective latching projection 11 and 12 is arranged between two latching projections 11 and 12 of the respective opposite area 111 and 121 or protrudes into the intermediate area between two projecting latching projections 11 and 12 of the opposite area 11 and 12 . The individual ends 110 and 120 of the latching projections 11 and 12 or the second latching projection sections 114 and 124 are arranged so that these do not contact the projecting latching projections 11 and 12 of the opposite area 111 and 121 . In the present embodiment all latching projections 11 and 12 are equally developed and aligned and do not contact each other.
[0124] The alignment of the latching projections 11 and 12 occurs in such a manner that the channel area 13 features a closed cross-section, or a U-shaped channel cross-section.
[0125] In the present embodiment the cable holding element 1 comprehends in each case four first latching projections 11 and four second latching projections 12 . The ends of the second latching projection sections 123 and 124 are inclined towards the common base body 100 or to the level determined by the trailing edges 103 .
[0126] For simple assembly two fastening elements 107 are arranged in the area of the base plate, and which facilitate the tool-free and releasable fastening of the cable holding 50 to a and/or with device 60 and/or with its frame 61 .
[0127] The latching projections 11 and 12 in the present embodiment of the invention are developed to be elastically bendable and to be resilient and consist of synthetic materials, namely polyethylene. The consistency of the polyethylene is thereby selected in such a manner so that the latching elements feature a bending stiffness and elasticity that allow a swivelling of the individual latching elements 11 and 12 , so that a cable 2 can be inserted through pressure onto the latching elements 11 and 12 in the channel area 13 . After the bending the latching elements 11 and 12 return to their initial position. Alternatively, the cable holding element 1 can also be made from polyethylene or other elastically bendable and resilient synthetic materials.
[0128] When inserting a cable 2 the latching projections 11 and 12 are bent by the pressure of the cable 2 in direction of the base body 10 or the common base body 11 and let the cable 2 enter the channel cross-section. If the cable is in the channel cross-section the latching elements 11 return to their initial position due to their elasticity. The latching projections 11 and 12 can thus be resiliently or elastically swivelled at one level normal to the longitudinal direction of the cable holding element 1 .
[0129] The shown flat-formed latching projections 11 and 12 project from the areas 111 and 121 and confine the channel area 13 . The latching projections 11 and 12 are developed in a bent manner as profile parts and feature in their longitudinal direction a flat profile with a constant cross-section. The proceed direction of the latching projection 11 and 12 proceeds at one level normal to the longitudinal direction of the cable holding element 1 . The flat profile has in longitudinal direction of the cable holding element 1 an essentially greater extension than in a direction normal to the longitudinal direction of the cable holding element 1 . As already mentioned, a relation of 4:1 to 4:1.5, in particular 4:1.3, between the extension of the maximum dimension of the flat profile of the latching projection 11 and 12 in longitudinal direction of the cable holding element 1 and the dimension of the profile of latching projection 11 and 12 in a direction normal thereto is preferable.
[0130] An advantageous embodiment is given in the form of a cable holding element 1 for the accommodation of one or multiple cables 2 comprehending a base body 10 as well as a number of latching projections 11 and 12 projecting from the base body 10 , that project from areas 111 and 121 opposite each other of the base body 10 , whereby the latching projections 11 and 12 and, if applicable, the base body 10 define a channel area 13 for the guiding of cables 2 , characterised in that the latching projections 11 and 12 preferably interlock without contact i.e. in a comb-like manner, so that the end 110 , 120 of at least one of the latching projections 11 and 12 , which project from one area 111 and 121 , is arranged and/or protrudes between two latching projections 11 and 12 projecting from the respective opposite area 111 and 121 .
[0131] A particularly advantageous embodiment is further given in the form of a cable holding element as aforesaid, characterised in that the latching projections 11 and 12 confining the channel area 13 are formed in an L-shape, which are at a distance opposite each other, so that the channel area 13 features a closed cross-section, or a U-shaped channel cross-section. In longitudinal direction of the channel area 13 the latching projections 11 and 12 are arranged in such a manner that these interlock, preferably without contact, in a comb-like manner, so that the end 110 , 120 of at least one of the latching projections 11 and 12 is arranged/protrudes between two latching projections opposite each other 11 and 12 . The latching projections 11 and 12 are configured to be elastically bendable and to be resilient, so that these can be swivelled against the base body 10 of the cable holding element 1 and after the swivelling return to their initial position.
[0132] A particularly advantageous embodiment is further given in the form of a cable holding element 1 as aforesaid, characterised in that the latching projections 11 and 12 are developed in a curved shape, in particular in an angled-hook shape, and feature two latching projection sections 113 , 114 , 123 , 124 , whereby the first latching projection section 113 , 123 projects in an angle of 70°-90°, preferably 85°-90°, in particular exactly vertically and/or normally, from the respective area 111 and 121 and whereby the second latching projection section 114 , 124 continues at the distant end of the respective area of the first latching projection section 113 , 123 and projects in an angle, in particular in an angle between 70° to 110°, preferably 90°, to the first latching projection section 113 , 123 in direction of the latching projections 11 and 12 , which project from the respective areas 111 and 121 opposite each other, and/or that the two latching projection sections 113 , 114 , 123 , 124 are developed integrally, in particular from a flat body and/or a profile rod, which feature between the first and the second latching projection section 113 , 114 , 123 , 124 an arc 115 , 125 .
[0133] A particularly advantageous embodiment is further given in the form of a cable holding element 1 as aforesaid, characterised in that the two latching projection sections 113 , 114 , 123 , 124 enclose an angle of no less than or equal to 90°, and/or that the two areas 111 and 121 from which the latching projections 11 and 12 project run parallel to another and/or lie at one level, and/or that the respective number of latching projections 11 and 12 , which project from the two areas 111 and 121 , deviate by no more than one, and/or that the ends of the latching projections 11 and 12 or the ends of the second latching projection sections 123 , 124 are inclined towards the base body 10 .
[0134] A particularly advantageous embodiment is further given in the form of a cable holding element 1 as aforesaid, characterised in that for each latching projection 11 and 12 , of which the end is arranged between two projecting latching projections 11 and 12 of the respective opposite area 111 and 121 , another projecting latching projection 15 , 16 from the opposite area 111 and 121 is foreseen, of which the end 150 , 160 is approximated to the end of the respective latching projection 11 and 12 and lies opposite, whereby in particular the front sides of the ends 110 , 120 150 , 160 of the other latching projections 15 , 16 and the latching projection 11 and 12 lie opposite each other.
[0135] A particularly advantageous embodiment is further given in the form of a cable holding element 1 as aforesaid, characterised in that the other latching projections 15 , 16 each feature a first latching projection section 151 , 161 , that projects from the base body 10 in an angle, in particular in an angle of 70°-90°, preferably 90°, and features a second latching projection section 152 , 162 , that continues the first latching projection section 151 , 152 and projects from the first latching projection section 151 , 152 , that in particular the form and/or alignment of the first and/or second latching projection section 151 , 152 , 161 , 162 of the other latching projections 15 , 16 corresponds to the form and alignment of the first and/or second latching projection sections 113 , 114 , 123 , 124 of the latching projections 11 and 12 , and that in particular the length of the first latching projection section 151 , 161 of the other latching projections 15 , 16 corresponds to the length of the first latching projection section 113 , 123 of the latching projections 11 and 12 .
[0136] A particularly advantageous embodiment is further given in the form of a cable holding element 1 as aforesaid, characterised in that the latching projections 11 and 12 projecting from the first area 111 and/or from the second area 121 are developed and/or aligned equally, and/or that all other latching projections 11 and 12 are developed equally, and/or that the other latching projections 15 , 16 projecting from the first area 111 and/or from the second area 121 are developed and/or aligned equally, and/or that all other latching projections 15 , 16 are developed equally.
[0137] A particularly advantageous embodiment is further given in the form of a cable holding element 1 as aforesaid, characterised in that the latching projections 11 and 12 project from two areas 111 and 121 , whereby a number of first latching projections 11 project from the first of both areas 111 and a number of second latching projections 12 project from the second of the two areas 121 , and/or that the first latching projections 11 project from subareas of the first area 111 , which lie on a first straight line 116 and/or that the second latching projections 12 project from subareas of the second area 121 , which lie on a second straight line 126 , whereby the first straight line 116 and the second straight line 126 are preferably aligned in a parallel manner to each other, and/or that a number of the other latching projections 15 , 16 and/or form subareas of the second area 121 project, which lie on the first straight line 116 , and the remaining of the other latching projections 16 project from subareas of the second area 121 , which lie on the second straight line 126 , and/or that between each of the two latching projections 11 and 12 a respective other latching projection 15 , 16 is arranged, and/or that the second latching projection sections 114 , 124 of the latching projections 11 and 12 , if applicable, also the second latching projection sections 152 , 162 of the other latching projections 15 , 16 lie at the same level, and/or that the base body 10 features in the areas opposite the latching projections 11 and 12 at least one recess 105 .
[0138] A particularly advantageous embodiment is further given in the form of a cable holding element 1 as aforesaid, characterised in that the base body 10 features at least one, in particular two, in particular vertically and/or normally, projecting projections 17 , 18 from it, of which the individual latching projections 11 and 12 and, if applicable, the other latching projections project 15 / 16 , and/or that the channel cross-section of the channel area 13 narrows and/or extends at least in a subarea along the longitudinal extension of the channel area 13 , and/or that the latching projections 11 and 12 are developed to be elastically bendable and/or to be resilient, and/or that the relation of the width in longitudinal direction of the cable holding element 1 to the thickness of the latching projections 11 and 12 is between 4:1 to 4:1.5, in particular 4:1.3.
[0139] A particularly advantageous embodiment is further given in the form of a cable holding element 1 as aforesaid, characterised in that the latching projections 11 and 12 , if applicable, the other latching projections 15 , 16 and/or the entire cable holding element 1 , are made from synthetic materials, in particular polyethylene PE and/or polypropylene PP.
[0140] A particularly advantageous embodiment is further given in the form of a cable holding 50 comprehending a number of cable holding elements 1 as aforesaid, characterised in that the individual cable holding elements 1 are arranged equally aligned on a common base body 100 , whereby preferably the base body 100 features fastening means 107 for, in particular releasable without tools, fastening of cable holdings 50 to a device, in particular with a frame 61 of a device 60 , and/or that the common base body 100 in the areas opposite of the latching projections 11 and 12 features at least one recess 105 .
[0141] A particularly advantageous embodiment is further given in the form of a cable holding 50 as aforesaid, comprehending in particular two cable holding elements 1 , characterised in that the common base body 100 develops a W-shaped angle profile 101 , whereby the latching projections 11 and 12 of the two cable holding elements 1 project from the central bow edge 102 of the W-shaped angle profile 101 and, in addition, latching projections 11 and 12 of each of the cable holding elements 1 project from the trailing edges 103 of the W-shaped angle profile, and whereby, if applicable, projections project from the bow edge 102 and/or the trailing edge 103 , of which the latching projections project 11 and 12 , and/or whereby, if applicable, the W-shaped angle profile 101 features in the area of the central bow edge 102 , preferably also in both trailing edges 103 , 104 , a right angle.
[0142] A particularly advantageous embodiment is further given in the form of a cable holding 50 as aforesaid, characterised in that the common base body 100 is developed in a flat and/or even manner and the individual latching projections 11 and 12 project towards the same side from the base body 100 , and/or that the individual cable holding elements 1 on the base body 100 are arranged equally and, if applicable, are arranged side by side and/or consecutively, and/or that the first and second straight line 116 , 117 are arranged in a parallel manner to each other.
[0143] A particularly advantageous embodiment is further given in the form of an electronic device, in particular betting and/or gaming device, with a cable holding 50 as aforesaid or with a plurality of cable holding elements 1 as aforesaid.
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A cable holding element configured for attachment to either an angled frame having internal corners, or external corners or both. The cable holding element includes a base body and rows of latching projections that project from the base body to define at least one channel area for holding cable. The latching projections each have a first section and a second section. The first section and the second section form an acute angle towards the base body. A first row of latching projections opposes a second row of latching projections. The opposing latching projections cooperate to interlock without contact, in a comb-like manner to hold cable within the cable holding element and to form guiding structure that guides cable into and out from the channel area. In an alternate embodiment, the cable holding element has a flat base body capable of attachment to a planar surface.
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FIELD OF INVENTION
This invention concerns blends of poly(ethylene terephthalate) [PET], poly(ethylene naphthalate) [PEN] and a compatibilizing amount of a copolyester. Clear containers containing less than 10% haze produced from such blends are useful for a variety of packaging applications, particularly hot-fill food and beverage containers where good barrier and clarity are needed.
BACKGROUND OF THE INVENTION
Biaxially oriented containers constructed of PET by either injection stretch blow molding (single stage) or reheat stretch blow molding (two stage) processes have about 80° C. glass transition (Tg) temperature, about 5 cc-mil/100 in 2 -24 hr-atm oxygen permeability coefficient at 30° C. and 68% RH, and have found wide use in food and beverage applications that do not require hot filling. The upper use temperature of these containers can be increased by heat setting techniques to provide some hot-fill capabilities, but even when heat-set, these PET containers may have limited upper temperature uses. Thus PET has enjoyed popularity in a large number of packaging applications, but does not meet the requirements of some specific food and beverage packaging applications.
PEN has been found useful for producing monolayer biaxially oriented containers having about 1.5 cc-mil/100 in 2 -24 hr-atm oxygen permeability coefficient at 30° C. and 68% RH with Tg of about 125° C. by either single stage or two stage processes, and these containers will be useful for a variety of food and beverage applications requiring both good barrier to oxygen (and other gases) and hot-fill capabilities.
As the markets for polyester packaging materials have developed, the needs for materials having improved performance over that offered by PET has been recognized. While it is also recognized that these needs could be filled by a material such as PEN, there are areas where some improvement over PET is desired, but the performance (and expense) of PEN is not needed or desired. These market segments could be filled by packages produced from blends of PET/PEN which would have performance levels between the two pure components. However, to be useful for most applications a packaging material would normally be clear (for some uses good clarity is a requirement), and blends of PET/PEN are generally incompatible and produce opaque parts.
Some prior information on PET/PEN blends may be found in U.S. Pat. No. 3,546,320 (1970) assigned to Sun Oil Co., U.S. Pat. No. 3,937,754 (1976) assigned to Teijin, Ltd., Japanese Patents 72/24177 (1972), 81/49014 (1981), 74/22957 (1974), and 75/74652 (1975) all assigned to Teijin, Ltd. Further information may also be found in Research Disclosures 28340 (1987) and 29410 (1988).
It has now been found that clear compatible blends containing less than 10% haze of PET/PEN can be made through the use of a compatibilizing amount of a copolyester as hereinafter disclosed, thereby avoiding a significant amount of processing and the costs associated therewith.
SUMMARY OF THE INVENTION
This invention relates to tricomponent polymer blends containing PET, PEN and a compatibilizing copolyester. The blends of this invention are suitable for producing clear, biaxially oriented containers that are useful for food and beverage applications requiring good barrier and hot-fill capabilities. More specifically, the present invention is directed to a clear polymer blend containing less than 10% haze comprising
(A) about 15 to about 80 weight % of poly(ethylene terephthalate),
(B) about 80 to about 5 weight % of poly(ethylene naphthalenedicarboxylate), and
(C) about 5 to about 15 weight % of a copolyester which comprises
(1) an acid component comprising repeating units of from about 10 to about 20 mole % terephthalic acid and about 80 to about 90 mole % naphthalenedicarboxylic acid, and
(2) a glycol component comprising repeating units of ethylene glycol,
wherein the total mole % of acid component and glycol component in the copolyester are each 100 mole %.
DETAILED DESCRIPTION OF THE INVENTION
In the blends of the invention it is preferred that component (A) is present in an amount of about 35 to about 60 weight %, component (B) is present in an amount of about 30 to about 60 weight %, and that component (C) is present in an amount of about 5 to about 10 weight %.
The clear polymer blends of the present invention have less than 10% haze, preferably less than 5% haze. The haze value can be determined according to ASTM Procedure D1003-61.
Articles, e.g., containers such as 2-liter bottles, prepared from blends of polymers made in accordance with the invention have oxygen permeability values ranging from about 3.5 to less than about 1.75 cc-mil/100 in 2 -24 hr-atm depending upon the amount of PEN in the blend. A 2-liter PET container has an oxygen transmission rate of about 100 ul/day. Thus, 2-liter containers prepared from the blends of the invention have an oxygen transmission rate of about 35 to about 96 ul/day at 68% relative humidity (RH) and at about 30° C. Furthermore, articles such as containers and film made from the blends of the present invention typically have a glass transition temperature (Tg) as measured by differential scanning calorimetry (DSC) of about 85° to about 111° C.
The PEN and PET polymers, as well as the copolyester of component (C), which are useful in the blends of this invention can be readily prepared using typical polyester polycondensation reaction conditions known in the art. They may be made by either batch or continuous processes to the final I.V. value desired. Examples of methods which may be employed to prepare PET, PEN, and compatibilizing copolyester useful in the present invention can be found in U.S. Pat. No. 4,617,373.
Either or both of the PET and PEN polymers may optionally be modified with up to 15 mol %, preferably up to 10 mol %, of one or more different dicarboxylic acids (i.e., different than a naphthalenedicarboxylic acid isomer(s) in the case of PEN and terephthalic acid in the case of PET) containing 4 to 36 carbon atoms, preferably 8 to 20 carbon atoms; and/or one or more different glycols (i.e., different than ethylene glycol) containing 3 to 20 carbon atoms, preferably 3 to 12 carbon atoms.
Typical modifying dicarboxylic acids for PEN include terephthalic, isophthalic, adipic, glutaric, cyclohexanedicarboxylic, azelaic, sebacic, fumaric, biphenyldicarboxylic, stilbenedicarboxylic, and the like. Typical examples of modifying glycols for PEN include 1,4-butanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, and the like. The PEN polymers are preferably derived from 2,6-naphthalenedicarboxylic acid and also contain, optionally, up to about 25 mol % (preferably up to 15 mol %, most preferably up to 10 mol %) of one or more residues of different naphthalenedicarboxylic acid isomers such as the 1,2-, 1,3-, 1,4-, 1,5-, 1,6-, 1,7-, 1,8-, 2,3-, 2,4-, 2,5-, 2,7- or 2,8-isomers. PEN polymers based primarily on 1,4-, 1,5-, or 2,7naphthalenedicarboxylic acid are also useful.
Typical modifying dicarboxylic acids for PET include isophthalic acid, adipic acid, glutaric acid, azelaic acid, sebacic acid, fumaric acid, stilbenedicarboxylic acid, cyclohexanedicarboxylic acid, biphenyldicarboxylic acid, any of the isomers of naphthalenedicarboxylic acid, and the like. Typical modifying glycols for PET include 1,4.butanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, and the like.
In similar fashion, the acid component and glycol component of the compatibilizing copolyester (i.e., component (C)) can each be modified with up to about 20 mole %, preferably up to 10 mole %, of one or more different dicarboxylic acids or glycols. The same modifying glycols and acids disclosed above for use with PET and/or PEN can be used to modify the compatibilizing copolyester.
The compositions of the present invention are suited for hot-fill food and beverage packaging applications. The particular overall blend composition desired can be determined by the barrier and thermal properties needed for end use requirements.
The blends of this invention can be prepared by standard blending techniques known in the polyester art.
The inherent viscosities (I.V.'s) of the polymers of the blends typically range from about 0.5 to about 1.0, preferably about 0.65 to about 0.75. I.V. can be determined in a 60/40 phenol/tetrachloroethane solution at 25° C. at a concentration of 0.5 g/100 ml.
The following examples are to illustrate the invention but should not be interpreted as a limitation thereon.
EXAMPLE 1
Two hundred eighty-five grams of powdered PET (I.V. - 0.72) were blended with 15 grams of powdered poly(ethylene 2,6-naphthalenedicarboxylate) [PEN], dried under a vacuum overnight and subsequently extruded into a 2 to 3 mil thick film on a small Brabender® extruder equipped with a six-inch wide film die. The film had a haze value of >10% as measured according to ASTM D1003-61 and was determined to have an oxygen permeability coefficient of 11.1 cc-mil/100 in 2 -24 hr-atm, a carbon dioxide permeability coefficient of 60.2 and a water vapor transmission rate of 3.7 g-mil/100 in 2 -24 hr. The blend's thermal properties were measured on a Differential Scanning Calorimeter (DSC) and determined to have a glass transition temperature (Tg) on the second heating cycle of about 79° C. which is slightly higher than the Tg of the neat PET (75° C.) but lower than the Tg of the neat PEN (124° C.).
EXAMPLE 2
Two hundred seventy grams of powdered PET (I.V.-0.72) were blended with 30 grams of powdered PEN (I.V.-0.72) and treated in the same way as described in Example 1. Again the film had a haze value >10% but had one Tg (second heating cycle) at 81° C. which is between the Tg's of PET (75° C.) and PEN (124° C.). Then sample, as measured with MOCON's OXTRAN 100, PERMATRAN C and PERMATRAN W®, permeability and water vapor transmission instruments, was found to have an oxygen permeability coefficient of around 10.6 cc-mil/100 in 2 -24 hr-atm, a carbon dioxide coefficient of 47.5 cc-mil/100 in 2 -24 hr.-atm and a water vapor transmission rate of 2.8 g-mil/100 in 2 -24 hr.
EXAMPLE 3
Two hundred seventeen and eight tenths grams of PET powder were dry blended with eighty-two and two tenths grams of powdered PEN and processed in the same manner as described in Example 1. The 2 to 3 mil film produced had a haze value of >10% and a second heating cycle Tg of around 85° C. The oxygen permeability coefficient was determined to be about 7.9 cc-mil/100 in 2 -24 hr-atm, the carbon dioxide permeability coefficient was measured to be 45.2 cc-mil/100 in 2 -24 hr-atm and the water vapor transmission rate was measured at 2.9 g-mil/100 in 2 -24 hr.
EXAMPLE 4
Pellet/pellet blends of PEN/PET (100/0, 75/25, 50/50, 25/75, and 0/100) were prepared and dried at 175° C. in a dehumidifier dryer (Conair®, for example) for about 16 hours. These blends were then injection molded into 57 gram parisons with a Cincinnati Milacron® 150-6 single cavity injection molding machine using a barrel temperature of about 315° C., injection pressure of about 1500 psi, back pressure of about 200 psi, screw speed of about 130 rpm, and cycle times of about 12 seconds. With these conditions the total shot size (parison and runner) was 75 grams with a residence time of 2 minutes, 45 seconds. The pure components gave clear parisons, but under these conditions the blends produced opaque parisons. The parisons were heated to between 120° to 150° C. parison outside surface temperature and 2-liter oriented bottles produced with a laboratory reheat stretch blow (RHB) unit. RHB bottles produced from these blends generally had good material sidewall distribution. The opaque bottles (produced with the PEN/PET, 74/25, 50/50, and 25/75 blends) had oxygen permeabilities that were median between pure PEN and PET bottles, with the bottles that were rich in PEN having the lower permeability coefficients.
EXAMPLE 5
Pellet/pellet blends of PEN/PET again were produced as described in Example 4, but this time pellets (10 weight % of the total blend weight) of a poly(ethylene naphthalate-terephthalate) copolymer containing about 15 mole % of the poly(ethylene terephthalate) moiety were added to the blend. After drying, these blends were injection molded into parisons as described in Example 4, and clear parisons containing <5% haze were obtained. This result indicates that having 10 weight % copolymer present in the blend will help compatibilize the mixture enough to produce clear injection molded parts. Oriented 2-liter bottles were produced from these parisons as described in Example 6 with similar oxygen permeability results. However, these RHB bottles had very poor sidewall material distribution as would be expected from stretching copolymers that have limited strain hardening characteristics.
EXAMPLE 6
A pellet/pellet PEN/PET (25/75) blend containing 10 weight % of poly(ethylene naphthalate-terephthalate) copolymer was processed with a Nissei® 250 (single stage) stretch blow molding machine and clear 32 ounce wide mouth (83 mm finish) containers containing <5% haze were produced. These clear containers had excellent sidewall material distribution and oxygen transmission rate of 23 ul/day at 23° C. with 100% RH on the inside of the container and 50% on the outside (a PET container would have about 30 ul/day and a PEN container would have about 6 ul/day oxygen transmission rates under these conditions).
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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This invention concerns blends of poly(ethylene terephthalate), poly(ethylene naphthalate) and a compatibilizing amount of a copolyester which comprises (1) an acid component comprising repeating units of from about 10 to about 20 mole % terephthalic acid and about 80 to about 90 mole % naphthalenedicarboxylic acid, and (2) a glycol component comprising repeating units of ethylene glycol. Clear containers containing less than 10% haze produced from such blends are useful for a variety of packaging applications, particularly hot-fill food and beverage containers where good barrier and clarity are needed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 09/914,046, filed Oct. 1, 2001. application Ser. No. 09/914,046 is a National Phase Filing under 35 U.S.C. § 371 of International Application No. PCT/US00/04392, filed Feb. 22, 2000, which published in the English language as WO 00/50008, on Aug. 31, 2000, and which claims the benefit of U.S. Application No. 60/121,133, filed Feb. 22, 1999. The disclosures of each of these applications are hereby incorporated by reference herein in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention provides methods for the preparation of antibody fragment-targeted liposomes (“immunoliposomes”), including lipid-tagged antibody fragment-targeted liposomes, methods for in vitro transfection using the immunoliposomes, and methods for systemic gene delivery in vivo. The liposomes of the present invention are useful for carrying out targeted gene delivery and efficient gene expression after systemic administration. The specificity of the delivery system is derived from the targeting antibody fragments.
[0004] 2. Background Art
[0005] An ideal therapeutic for cancer would be one that selectively targets a cellular pathway responsible for the tumor phenotype and which is nontoxic to normal cells. While cancer treatments involving gene therapy have substantial promise, there are many issues that need to be addressed before this promise can be realized. Perhaps foremost among the issues associated with macromolecular treatments is the efficient delivery of the therapeutic molecules to the site(s) in the body where they are needed. A variety of delivery systems (a.k.a. “vectors”) have been tried including viruses and liposomes. The ideal delivery vehicle would be one that could be systemically (as opposed to locally) administered and which would thereafter selectively target tumor cells wherever they occur in the body.
[0006] The infectivity that makes viruses attractive as delivery vectors also poses their greatest drawback. Consequently, a significant amount of attention has been directed towards non-viral vectors for the delivery of molecular therapeutics. The liposome approach offers a number of advantages over viral methodologies for gene delivery. Most significantly, since liposomes are not infectious agents capable of self-replication, they pose no risk of transmission to other individuals. Targeting cancer cells via liposomes can be achieved by modifying the liposomes so that they selectively deliver their contents to tumor cells. There now exists a significant knowledge base regarding specific molecules that reside on the exterior surfaces of certain cancer cells. Such cell surface molecules can be used to target liposomes to tumor cells, because the molecules that reside upon the exterior of tumor cells differ from those on normal cells.
[0007] The publications and other materials used herein to illuminate the background of the invention or provide additional details respecting the practice, are incorporated by reference.
[0008] Current somatic gene therapy approaches employ either viral or non-viral vector systems. Many viral vectors allow high gene transfer efficiency but are deficient in certain areas (Ledley F D, et al. Hum. Gene Ther . (1995) 6:1129-1144). Non-viral gene transfer vectors circumvent some of the problems associated with using viral vectors. Progress has been made toward developing non-viral, pharmaceutical formulations of genes for in vivo human therapy, particularly cationic liposome-mediated gene transfer systems (Massing U, et al., Int. J. Clin. Pharmacol. Ther . (1997) 35:87-90). Features of cationic liposomes that make them versatile and attractive for DNA delivery include: simplicity of preparation; the ability to complex large amounts of DNA; versatility in use with any type and size of DNA or RNA; the ability to transfect many different types of cells, including non-dividing cells; and lack of immunogenicity or biohazardous activity (Felgner P L, et al., Ann. NY Acad. Sci . (1995) 772:126-139; Lewis J G, et al., Proc. Natl. Acad. Sci. USA (1996) 93:3176-3181). More importantly from the perspective of human cancer therapy, cationic liposomes have been proven to be safe and efficient for in vivo gene delivery (Aoki K et al., Cancer Res . (1997) 55:3810-3816; Thierry A R, Proc. Natl. Acad. Sci. USA (1997) 92:9742-9746). More than thirty clinical trials are now underway using cationic liposomes for gene therapy (Zhang W et al., Adv. Pharmacology (1997) 32:289-333; RAC Committee Report: Human Gene Therapy Protocols-December 1998), and liposomes for delivery of small molecule therapeutics (e.g., antifungal and conventional chemotherapeutic agents) are already on the market (Allen T M, et al., Drugs (1997) 54 Suppl 4:8-14).
[0009] The transfection efficiency of cationic liposomes can be dramatically increased when they bear a ligand recognized by a cell surface receptor. Receptor-mediated endocytosis represents a highly efficient internalization pathway present in eukaryotic surface (Cristiano R J, et al., Cancer Gene Ther . (1996) 3:49-57, Cheng P W, Hum. Gene Ther . (1996) 7:275-282). The presence of a ligand on a liposome facilitates the entry of DNA into cells through initial binding of ligand by its receptor on the cell surface followed by internalization of the bound complex. A variety of ligands have been examined for their liposome-targeting ability, including transferrin and folate (Lee R J, et al., J. Biol. Chem . (1996) 271:8481-8487). Transferrin receptors (TfR) levels are elevated in various types of cancer cells including prostate cancers, even those prostate cell lines derived from human lymph node and bone metastases (Keer H N et al., J. Urol . (1990) 143:381-385); Chackal-Roy M et al., J. Clin. Invest . (1989) 84:43-50; Rossi M C, et al., Proc. Natl. Acad. Sci. USA (1992) 89:6197-6201; Grayhack J T, et al., J. Urol . (1979) 121:295-299). Elevated TfR levels also correlate with the aggressive or proliferative ability of tumor cells (Elliot R L, et al., Ann. NY Acad. Sci . (1993) 698:159-166). Therefore, TfR levels are considered to be useful as a prognostic tumor marker, and TfR is a potential target for drug delivery in the therapy of malignant cells (Miyamoto T, et al., Int. J. Oral Maxillofac. Surg . (1994) 23:430-433: Thorstensen K, et al., Scand. J. Clin. Lab. Invest. Suppl . (1993) 215:113-120). In our laboratory, we have prepared transferrin-complexed cationic liposomes with tumor cell transfection efficiencies in SCCHN of 60%-70%, as compared to only 5-20% by cationic liposomes without ligand (Xu L, et al., Hum. Gene Ther . (1997) 8:467-475).
[0010] In addition to the use of ligands that are recognized by receptors on tumor cells, specific antibodies can also be attached to the liposome surface (Allen T M et al., (1995) Stealth Liposomes , pp. 233-244) enabling them to be directed to specific tumor surface antigens (including but not limited to receptors) (Allen T M, Biochim. Biophys. Acta (1995) 1237:99-108). These “immunoliposomes,” especially the sterically stabilized immunoliposomes, can deliver therapeutic drugs to a specific target cell population (Allen T M, et al., (1995) Stealth Liposomes , pp. 233-244). Park, et al. (Park J W, et al., Proc. Natl. Acad. Sci. USA (1995) 92:1327-1331) found that anti-HER-2 monoclonal antibody (Mab) Fab fragments conjugated to liposomes could bind specifically to HER-2 overexpressing breast cancer cell line SK-BR-3. The immunoliposomes were found to be internalized efficiently by receptor-mediated endocytosis via the coated pit pathway and also possibly by membrane fusion. Moreover, the anchoring of anti-HER-2 Fab fragments enhanced their inhibitory effects. Doxorubicin-loaded anti-HER-2 immunoliposomes also showed significant and specific cytotoxicity against target cells in vitro and in vivo (Park J W, et al., Proc. Natl. Acad. Sci. USA (1995) 92:1327-1331). In addition, Suzuki et al., (Suzuki S, et al., Br. J. Cancer (1997) 76:83-89) used an anti-transferrin receptor monoclonal antibody conjugated immunoliposome to deliver doxorubicin more effectively in human leukemia cells in vitro. Huwyler et al. (Huwyler J, et al., Proc. Natl. Acad. Sci. USA (1996) 93:14164-14169) used anti-TfR monoclonal antibody immunoliposome to deliver daunomycin to rat glioma (RT2) cells in vivo. This PEGylated immunoliposome resulted in a lower concentration of the drug in normal tissues and organs. These studies demonstrated the utility of immunoliposomes for tumor-targeting drug delivery. It should be noted that the immunoliposome complexes used by Suzuki et al. and Huwyler et al. differ from those of the invention described herein in that they are anionic liposomes and that the methods used by Suzuki et al. and Huwyler et al. are not capable of delivering nucleic acids.
Single-Chain Antibody Fragments
[0011] Progress in biotechnology has allowed the derivation of specific recognition domains from Mab (Poon R Y, (1997) Biotechnology International: International Developments in the Biotechnology Industry , pp. 113-128). The recombination of the variable regions of heavy and light chains and their integration into a single polypeptide provides the possibility of employing single-chain antibody derivatives (designated scFv) for targeting purposes. Retroviral vectors engineered to display scFv directed against carcinoembryonic antigen, HER-2, CD34, melanoma associated antigen and transferrin receptor have been developed (Jiang A, et al., J. Virol . (1998) 72:10148-10156, Konishi H, et al., Hum. Gene Ther . (1994) 9:235-248: Martin F, et al., Hum. Gene Ther . (1998) 9:737-746). These scFv directed viruses have been shown to target, bind to and infect specifically the cell types expressing the particular antigen. Moreover, at least in the case of the carcinoembryonic antigen, scFv was shown to have the same cellular specificity as the parental antibody (Nicholson I C, Mol. Immunol . (1997) 34:1157-1165).
[0012] The combination of cationic liposome-gene transfer and immunoliposome techniques appears to be a promising system for targeted gene delivery.
BRIEF SUMMARY OF THE INVENTION
[0013] We constructed a variety of immunoliposomes that are capable of tumor-targeted, systemic delivery of nucleic acids for use in human gene therapy. Based upon the data given in the Examples below these immunoliposome-DNA complexes incorporating the TfRscFv are capable of producing a much higher level of transfection efficiency than the same liposome-DNA complex bearing the complete Tf molecule. Therefore, in one aspect of the invention the immunoliposomes of the invention can be used to produce a kit for high efficiency transfection of various mammalian cell types that express the transferrin receptor. In one aspect of the invention, we constructed an scFv protein with a lipid tag such that the lipid is added naturally by the bacterial cell to allow easy incorporation of the scFv into liposomes while also avoiding chemical reactions which can inactivate the scFv.
[0014] The lipid-tagged scFv-immunoliposomes are prepared basically by two methods: a lipid-film solubilization method and a direct anchoring method. The lipid-film solubilization method is modified from the detergent dialysis method, which was described by Laukkanen M L, et al., (Laukkanen M L, et al., Biochemistry (1994) 33:11664-11670) and de Kruif et al., (de Kruif et al., FEBS Lett . (1996) 399:232-236) for neutral or anionic liposomes, with the methods of both hereby incorporated by reference. This method is suitable for attaching lipid-tagged scFv to cationic liposomes as well. In the lipid-film solubilization method, the lipids in chloroform are evaporated under reduced pressure to obtain a dry lipid film in a glass round-bottom flask. The lipid film is then solubilized with 0.5-4%, preferably 1%, n-octyl β-D-glucoside (OG) containing the lipid-modified scFv and vortexed. After dilution with sterile water, the solution is briefly sonicated to clarity.
[0015] The second method for attaching lipid-tagged antibodies or antibody fragments is the direct anchoring method that is specifically useful for attaching the E. coli lipoprotein N-terminal 9 amino acids to an scFv (lpp-scFv) or other lipid-modified antibody or fragments and attaching these to preformed liposomes. For attaching the scFv to preformed liposomes, the lipid-modified scFv in 1% OG is added to preformed liposomes while vortexing, at volume ratios from 1:3 to 1:10. The mixture is vortexed for approximately a further 5-10 minutes to obtain a clear solution of scFv-immunoliposomes. The remaining OG and the uncomplexed scFv can be eliminated by chromatography, although they will not interfere very much with the subsequent usage. Separation experiments, i.e., ultrafiltration with Centricon-100 (Amicon), Ficoll-400 floatation (Shen D F, et al., Biochim. Biophys. Acta (1982) 689: 31-37), or Sepharose CL-4B (Pharmacia) chromatography, demonstrated that virtually all the lipid-tagged scFv molecules added have been attached or anchored to the cationic liposomes. This is an improvement over the much lower attachment rate of lpp-scFv to neutral or anionic liposomes. Therefore, this improvement makes it unnecessary to include a further purification step to remove the unattached scFv.
[0016] Any antibodies, antibody fragments, or other peptide/protein ligands that can be modified to have one or more lipid-tags on the surface are useful in the present invention. Other lipid-modification methods include directly conjugating a lipid chain to an antibody or fragment, as described in Liposome Technology, 2nd Ed., Gregoriadis, G., Ed., CRC Press, Boca Raton, Fla., 1992.
[0017] In another aspect of the invention a cysteine was added at the C-terminus of the scFv sequence and the protein was expressed in the inclusion bodies of E. coli , then refolded to produce active scFv. The C-terminal cysteine provided a free sulfhydryl group to facilitate the conjugation of the scFv to liposomes. There are two strategies which can be used in the conjugation process. 1) Pre-linking method: The first step is to conjugate the scFv-SH with the cationic liposome which contains a maleimidyl group or other sulfhydryl-reacting group, to make the scFv-liposome. The nucleic acids are then added to the scFv-liposome to form the scFv-liposome-DNA complex. The pre-linking is designated since scFv is linked before DNA complexing. 2) Post-linking method: This strategy is to complex the cationic liposome with nucleic acids first to form a condensed structure. The scFv-SH is then linked onto the surface of DNA-liposome complex to produce scFv-liposome-DNA. The post-linking is designated since scFv is linked after DNA complexing. The post-linking strategy ensures that 100% of scFv linked are on the surface of the complex, accessible to receptor binding. Therefore, this method can make a better use of the targeting ligand scFv and a better controlled inside structure of the complex.
[0018] The nucleic acid-immunoliposome complexes, regardless of whether the antibody or antibody fragment is lipid tagged or conjugated to the liposome, can be used therapeutically. Preferably the complexes are targeted to a site of interest, preferably to a cell which is a cancer cell, more preferably to a cell expressing a transferrin receptor. The targeting agent is the antibody or antibody fragment which preferably binds to a transferrin receptor. The nucleic acid is the therapeutic agent and is preferably a DNA molecule and more preferably encodes a wild type p53 molecule. The nucleic acid-immunoliposome complexes, preferably in a therapeutic composition, can be administered systemically, preferably intravenously.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
[0019] FIG. 1 show scFv TfR lipid-tag construction.
[0020] FIG. 2 shows a Western blot analysis of scFv-liposome-targeted p53 expression in vivo in tumor xenografts with systemic administration.
[0021] FIG. 3 shows pCMVp53 and pCMVpRO constructs.
[0022] FIG. 4 shows p53-3′Ad construction.
[0023] FIG. 5 shows construction of scFvTfR-cysteine with a His tag.
[0024] FIG. 6 shows construction of scFvTfR-cysteine without a His tag.
[0025] FIG. 7 shows construction of scFvTfR-cysteine with a cellulose binding domain (CBD) tag and with an S-tag.
[0026] FIG. 8 shows a Coomassie Blue stained SDS-polyacrylamide gel of purified TfRscFv protein produced by the conjugation method.
[0027] FIG. 9 shows a Western blot analysis of conjugation method produced TfRscFv-liposome-targeted p53 expression in vivo in tumor xenografts with systemic administration.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The invention is directed to immunoliposomes and methods of making and using these immunoliposomes. A variety of embodiments are disclosed including immunoliposomes with different tags and various methods with which to attach the scFv to the liposomes. The immunoliposomes may include lipid tags or be linked through a reducing group, which in a preferred embodiment is a free sulfhydryl.
[0029] Mutant forms of the tumor suppressor gene p53 have been associated with more than 50% of human cancers, including 15-50% of breast and 25-70% of metastatic prostate cancers. Abnormalities in p53 also correlate with poor prognosis in various types of malignancies. Therefore, the capability to systemically deliver and target gene therapy specifically to tumors to efficiently restore wtp53 function will be an important therapeutic modality in cancer treatment. Thus the immunoliposomes produced by the method of this invention will be useful as an effective new cancer therapeutic modality not just for restoration of wtp53 function but also as a tumor targeted systemic delivery vehicle for other therapeutic genes.
[0030] The invention is illustrated by the following Examples.
Example 1
Construction and Expression of Biosynthetically Lipid-Tagged scFv
1. Construction of the Expression Vector for TfRscFv
[0031] To construct the expression vector, we used the vector pLP1 which contains an amino acid linker sequence between the E. coli lipoprotein signal peptide (ssLPP) and the scFv cloning site (de Kruif et al., FEBS Lett . (1996) 399:232-236). This vector contains both c-myc and His 6 tag sequences that can be used for purification and detection of the expressed scFv ( FIG. 1 ).
[0032] We obtained a plasmid expression vector, pDFH2T-vecOK, which contains the single chain fragment for the 5E9 (Haynes et al., J. Immunol . (1981) 127:347-351) antibody linked to a DNA binding protein, which recognizes the human transferrin receptor (TfR). This vector also contains the sequence for a DNA binding protein, and there are no unique restriction enzyme sites flanking the scFv sequence in pDFH2T-vecOK. Therefore, we cloned the VH-linker-Vκ scFv by PCR amplification of the desired fragment using a 5′ primer (5′ GGCCCATGGAGGTGCAGCTGGTGG 3′ (SEQ ID NO:1)) (RB551) containing an NcoI site and a 3′ primer (RB552) (5′ CCGGAATTCGCGGCCGCTTTTATCTCCAGCTTGGTC 3′ (SEQ ID NO:2) containing a NotI site. The PCR amplification using primers RB551 and RB552 amplified the scFv for TfR from pDFH2T-vecOK from the Met at base 81 to Lys at base 821. The pLP1 vector also contains sequences for the E. coli lipoprotein signal peptide (ssLPP) and the E. coli lipoprotein N-terminal 9 amino acids (LPP), as described by Laukkanen M L, et al., (Laukkanen M L, et al., Biochemistry (1994) 33:11664-11670) and de Kruif et al (de Kruif et al., FEBS Lett . (1996) 399:232-236). The insertion of these sequences will lead to fatty acid acylation of the expressed signal in the E. coli host and its insertion into the bacterial membrane. The vector also has a non-critical 10 amino acid linker sequence to increase the space between the lipid-tag site and the scFv. Purification of the lipid modified scFv sequence from the bacterial membrane results in an active molecule that can be attached or inserted into liposomes.
2. Expression and Purification of the TfRscFv
[0033] We transformed E. coli expression host SF110 F′ with the expression vector constructed above. While the host cell is not critical it is preferred that it contain expressed lac repressor. A number of clones were selected and the one that produces the best yield of scFv was chosen. The lipid-modified scFv (lpp-scFv) was isolated from the bacterial membrane using Triton X-100 as described by de Kruif et al., (de Kruif et al., FEBS Lett . (1996) 399:232-236). For purification a single colony was resuspended in 200 μl LB containing 5% glucose and the appropriate antibiotics. The mixture was plated onto two 90 mm LB agar plates containing 5% glucose and the appropriate antibiotics and grown overnight. The next day, the cells were washed from the plates and used to inoculate a total of 5 liters of LB containing 0.1% glucose and the appropriate antibiotics. The cultures were grown at 25EC, at 200 rpm for 6 hours until the OD 600 reached 0.5 to 0.7. IPTG was added to a final concentration of 1 mM and the cultures were further incubated overnight. The next day, the bacterial cultures were collected by centrifugation and lysed in 200 ml lysis buffer at room temperature for 30 minutes. The sample was sonicated at 28 watts for 5 minutes with cooling on ice. The lysis buffer contains 20 mM HEPES pH 7.4 to 7.9, 0.5 M NaCl, 10% glycerol, and 0.1 mM PMSF. The only deviations from the cited protocol include washing and elution of metal affinity columns in buffer containing 20 mM HEPES pH 7.4 to 7.9, 0.5 M NaCl, 10% glycerol, 0.1 mM PMSF, 1% n-octyl β-D-glucoside (OG), and 10% glycerol containing 20 and 200 mM imidazole, respectively. The eluted samples of lpp-scFv were analyzed by SDS-PAGE and Western Blot using anti-c-myc antibody 9E 10 which confirmed that the purified scFv showed a band of the size of about 30 kDa.
Example 2
Preparation of Lipid-Tagged ScFv-Immunoliposomes by a Lipid-Film Solubilization Method
[0034] This example discloses a detailed procedure of lipid-film solubilization method to prepare lipid-tagged scFv-immunoliposomes. 5 μmol lipids (DOTAP/DOPE, 1:1 molar ratio) in chloroform are evaporated under reduced pressure to obtain a dry lipid film in a glass round-bottom flask. To the lipid film is added 0.5 ml 1% OG, 20 mM HEPES, 150 mM NaCl, pH 7.4, containing the lipid-modified scFv. This is incubated 10-20 minutes at room temperature and then vortexed to solubilize the lipid membrane. 2 ml sterile water is then added to dilute the scFv-lipid mixture. The solution is briefly sonicated to clarity in a bath-type sonicator at 20° C. The scFv-liposome is a clear solution with a limited amount of detergent OG left. The OG and the uncomplexed scFv can be eliminated by chromatography with Sepharose CL-4B or Sephacryl S500, even though they do not interfere a lot with the subsequent use.
Example 3
Preparation of Lipid-Tagged ScFv-Immunoliposomes by a Direct Anchoring Method
[0035] This example provides a direct anchoring method to prepare lipid-tagged scFv-immunoliposomes. 20 μmol lipids (LipA-H, see below for compositions and ratios) prepared as dry lipid film in a glass round-bottom flask is added to 10 ml pure water and sonicated in a bath-type sonicator for 10-30 min at room temperature (LipA, B, C) or at 65° C. (LipD, E, G, H, or any composition with Cholesterol (Chol)). The cationic liposomes prepared are clear solutions, their compositions and ratios are as follows:
[0000]
LipA
DOTAP/DOPE
1:1 molar ratio
LipB
DDAB/DOPE
1:1 molar ratio
LipC
DDAB/DOPE
1:2 molar ratio
LipD
DOTAP/Chol
1:1 molar ratio
LipE
DDAB/Chol
1:1 molar ratio
LipG
DOTAP/DOPE/Chol
2:1:1 molar ratio
LipH
DDAB/DOPE/Chol
2:1:1 molar ratio
[0036] For attaching the scFv to preformed liposomes, the lipid-modified scFv (Ipp-scFv) in 20 mM HEPES, 150 mM NaCl, pH 7.4, containing 1% OG is added to preformed liposomes while vortexing, at volume ratios from 1:3 to 1:10. The mixture is vortexed for a further 1 to 5 min to get a clear solution of scFv-immunoliposomes. The remaining OG and the uncomplexed scFv can be eliminated by chromatography, although they do not interfere very much with the subsequent usage. Separation experiments, i.e., ultrafiltration with Centricon-100 (Amicon), Ficoll-400 floatation (Shen D F, et al., Biochim Biophys Acta (1982) 689:31-37), or Sepharose CL-4B (Pharmacia) chromatography, demonstrated that virtually all the lipid-tagged scFv added have been attached or anchored to the cationic liposomes. This is in contrast to the much lower attachment rate of Ipp-scFv to neutral or anionic liposomes. Therefore, it is unnecessary to have a further purification step to get rid of the unattached scFv.
Example 4
Immunoreactivity of Lipid-tagged scFv-immunoliposomes Revealed by ELISA, FACS and Immunofluorescence
[0037] This example provides the characterization of the anti-TfR scFv-immunoliposomes with respect to their ability of binding to the TfR(+) cells. The human prostate cancer cell line DU145 and the human squamous cell carcinoma of head and neck cell line JSQ-3 served as the TfR+ target cells for these studies.
[0038] Indirect cellular enzyme-linked immunosorbent assay (ELISA) was employed to determine the immunoreactivity of the Ipp-scFv before and after attachment to liposomes. Confluent JSQ-3 cells in 96-well plates were fixed with 0.5% glutaraldehyde in PBS for 10 min at room temperature. The plate was blocked with 5% fetal bovine serum (FBS) in PBS at 30° C. for 30 min. The Ipp-scFv, scFv-immunoliposomes and liposomes were added to wells in duplicate and incubated at 4° C. overnight. After three PBS-washes, an anti-c-myc monoclonal antibody was added to each well in 3% FBS in PBS and incubated at 37° C. for 60 min. After three PBS-washes, HRP-labeled goat-anti-mouse IgG (Sigma) diluted in 3% FBS was added to each well and incubated for 30 min at 37° C. The plate was washed three times with PBS and 100 μl substrate 0.4 mg/ml OPD in citrate phosphate buffer (Sigma) was added to each well. The color-development was stopped by adding 100 μl 2 M sulfuric acid to each well. The plate was read by an ELISA plate reader (Molecular Devices Corp.) at 490 nm. Indirect cellular ELISA demonstrated that the anti-TfR scFv retained its immunoreactivity after incorporation into the liposome complex (Table 1).
[0000]
TABLE 1
Binding of anti-TfR scFv-liposomes to JSQ-3 cells*
Lip(A) only
0.142 ± 0.036
scFv-LipA1
1.134 ± 0.038
scFv-LipA2
1.386 ± 0.004
lpp-scFv
0.766 ± 0.009
*ELISA, OD 490 , Mean ± SD
scFv-LipA1: by lipid-film solubilization method.
scFv-LipA2: by direct anchoring method.
[0039] For FACS analysis, anti-TfR scFv-Lip(A), was incubated at 4° C. with JSQ-3 and DU145 cells, then with FITC-labeled sheep anti-mouse IgG, also at 4° C. Incubation of JSQ-3 cells with the scFv-Lip(A) resulted in a fluorescence shift identical to that observed with the unattached free anti-TfR lpp-scFv antibody, demonstrating a significant amount of binding to the target cells. In contrast, the untargeted liposome demonstrated very low binding to the cells. Similar results were observed with prostate tumor cell line DU145. Here also, the scFv-Lip(A) complex demonstrated clear, substantial binding to the tumor cells, as compared to the untargeted Lip(A). The FACS data is summarized in Table 2, where the fluorescence shift is indicated as the percent of the cells displaying fluorescence above the threshold level (percent of positive cells). In these studies also, the level of binding to the cells, represented by the percent of positive cells, was similar to that of the unattached free scFv further indicating that incorporation into the liposome complex did not inactivate the immunological activity of the anti-TfR lpp-scFv. It should be noted that the liposome preparation used for these initial experiments with DU145 was that optimized for JSQ-3 cells. Therefore, the binding of the scFv-targeted liposome complex to the prostate tumor cells can be further enhanced by the use of the liposome complex optimized for this cell type.
[0000]
TABLE 2
FACS Analysis of TfRscFv-liposome
Binding to JSQ-3 and DU145
JSQ-3
DU145
Transfected by
% Positive
Mean a
% Positive
Mean a
Untransfected
3.46
4.07
2.22
3.40
Lip(A)
9.69
6.26
4.51
4.07
scFv-LipA1
86.38
19.8
50.19
12.40
scFv-LipA2
89.58
21.30
39.52
11.1
Free lpp-scFv
85.09
21.30
78.09
18.40
HB21 b
99.44
69.80
98.70
64.90
a Mean of the relative fluorescence
b Parental monoclonal antibody of the anti-TfR scFv
[0040] Indirect immunofluorescence staining with scFv-liposome (where Lip(A) had been labeled with rhodamine-DOPE) and FITC-labeled anti-mouse IgG following anti-c-myc antibody, confirmed the binding of the scFv-targeted liposome complex to the JSQ-3 cells. The concurrence of the red and green fluorescence in the transfected cells demonstrates that the anti-TfR scFv (indicated by the FITC-labeled anti-c-myc antibody as green fluorescence) does indeed direct the rhodamine-labeled Lip(A) to the cells. Moreover, the high level of cellular binding of the scFv-Lip(A) system is demonstrated by the large percentage of red/green double-positive fluorescent cells.
Example 5
Optimization of scFv-immunoliposome Mediated Gene Transfection of Target Cells In Vitro
[0041] We determined the in vitro transfection efficiency of the anti-TfR scFv-Lip(A) complex in JSQ-3 cells using β-galactosidase as the reporter gene. In these studies the reporter construct used contained the β-galactosidase gene under the control of the CMV promoter (pCMVb), the same promoter used in pCMVp53 ( FIG. 3 ). The level of β-Gal expression in the transfected cells (correlating with the transfection efficiency) was assessed by β-Gal enzymatic assay (Xu L, et al., Hum. Gene Ther . (1997) 8:467-475). As shown in Table 3, the attachment of the anti-TfR scFv to the Lip(A) resulted in a doubling of the enzyme activity in the scFv-Lip(A)-pCMVb transfected cells, as compared to the untargeted liposome complex. This level of expression was also found to be virtually identical to that observed when transferrin itself was used as the targeting ligand (Tf-Lip(A)-pCMVb). Moreover, this increase in gene expression was shown to be reporter gene DNA dose dependent. Table 4 shows the optimization of scFv-liposome mediated transfection of JSQ-3 cells.
[0000]
TABLE 3
Transfection of JSQ-3 Cells by Anti-TfR scFv-liposomes*
DNA (μg/well)
Lip(A) only
Tf-Lip(A)
scFV-LipA1
scFv-LipA2
1.0
475
1031
997
1221
0.5
601
981
811
854
0.25
266
503
578
471
0.125
130
262
215
236
*milliunits/mg protein, β-galactosidase equivalent, β-Gal enzymatic assay
scFv-LipA1: by lipid-film solubilization method
scFv-LipA2: by direct anchoring method
[0000]
TABLE 4
Optimization of scFv-liposome transfection to JSQ-3*
DNA/Lip
Lip(A)
scFv-
scFv-
scFv-
scFv-
scFv-
(μg/nmol)
only
LipA1
LipA2
LipB
LipD
LipG
1/8
1.559
2.793
2.642
1.827
0.874
0.648
1/10
1.776
2.846
2.83
2.268
1.606
1.283
1/12
1.868
2.772
2.815
2.175
1.257
1.416
1/14
1.451
3.031
2.797
2.31
1.78
1.656
*β-Gal enzymatic assay, OD 405
scFv-LipA1: by lipid-film solubilization method
scFv-LipA2: by direct anchoring method
Example 6
scFv-immunoliposome Mediated p53 Gene Transfection Target to Tumor Cells Causing Sensitization to Chemotherapeutic Agents
[0042] 1. Anti-TfR scFv Facilitated Liposome-Mediated wtp53 Gene Transfection In Vitro
[0043] The expression of exogenous wtp53 in JSQ-3 tumor cells transfected with the anti-TfR scFv-targeted Lip(A)-p53-3′Ad was assessed by co-transfection of an expression plasmid (pBP100) which contains the luciferase reporter gene under the control of a p53 responsive promoter (Chen L, et al., Proc. Natl. Acad. Sci. USA (1998) 95:195-200). Consequently, the higher the level of exogenous wt p53 expression (representing the scFv-Lip(A)-p53-3′Ad transfection efficiency), the higher the level of luciferase activity. This luciferase enzyme activity is expressed as relative light units (RLU). As was demonstrated above with the β-gal reporter gene, the addition of the anti-TfR scFv as the targeting agent to the Lip(A)-p53-3′Ad complex resulted in a significant increase in transfection efficiency and wtp53 protein expression (as expressed by RLU of Luciferase activity) over the untargeted Lip(A)-p53-3′Ad complex (Table 5). Once again, the level of p53 expression in the scFv-Lip(A)-p53-3′Ad transfected cells was similar to that observed when transferrin itself was used as the targeting ligand (LipT(A)-p53-3′Ad). Therefore, these findings indicate that the anti-TfR single-chain antibody strategy is a useful method of targeting the cationic liposome complex, and delivering a biologically active wtp53 gene, to tumor cells.
[0000] TABLE 5 In Vitro p53 Expression Mediated by Different Liposomes in JSQ-3 cells Transfected by RLU* Medium + p53-3′Ad + pBP100 158 Lip(A) + p53-3′Ad + pBP100 4073 LipT(A) + p53-3′Ad + pBP100 7566 scFv-Lip(A1) + p53-3′Ad + pBP100 6441 *Relative light units per well
2. Anti-TfR scFv-Immunoliposome Mediated p53 Gene Restoration Sensitized the Tumor Cells to the Cytotoxicity of Cisplatin (CDDP).
[0044] For the p53-induced apoptosis study, mouse melanoma cell line B16 was transfected with anti-TfR scFv-immunoliposome complexed with p53-3′Ad ( FIG. 4 ) or pCMVpRo plasmid ( FIG. 3 ) DNA (scFv-Lip(A)-p53 and scFv-Lip(A)-pRo, respectively) at a dose of 5 μg DNA/2×10 5 cells in 2 sets of 6-well plates. For comparison, transferrin-liposome-DNA (LipT-p53 or LipT-pRo) were also transfected at a dose of 5 μg DNA/2×10 5 cells. 24 hours later, CDDP was added to one set of plates to 10 μM final concentration. 24 and 48 hours after the drug was added, both the attached and floating cells were collected for apoptosis staining. The cells were stained with an Annexin V-FITC Kit (Trevigen, Inc., Gaithersburg, Md.) according to manufacturer's protocol. Annexin V is a lipocortin, a naturally occurring blood protein and anti-coagulant. The stained cells were analyzed on a FACStar cytometer (Becton and Dickinson). Table 6 summarizes the results of the apoptosis analysis.
[0000]
TABLE 6
Apoptosis of B16 Cells Induced by Liposomal
p53-gene Restoration and CDDP*
24 hours
48 hours
Transfected by
−CDDP
+CDDP
−CDDP
+CDDP
Untransfected
0.22
4.4
6.33
20.11
LipA-p53
15.9
26.7
15.02
26.52
scFv-LipA-p53
13.9
38.4
34.94
43.7
scFv-LipA-pRo
8.1
19.9
24.14
37.59
Tf-LipA-p53
22.4
29.5
34.47
31.7
Tf-LipA-pRo
14.1
12.6
14.00
25.34
*% of apoptotic cells (Annexin V-FITC positive)
[0045] Without CDDP there was no increase in the percent of apoptotic cells induced at 24 hours by the addition of the scFv ligand as compared to the amount induced by the liposome complex alone. However, by 48 hours, there is a greater than 2-fold increase in the percent of apoptotic cells by the addition of the targeting scFv to the lipoplex. With CDDP there is a significant increase in apoptotic cells (approximately 1.5-fold) even at 24 hours as compared to the untargeted liposome complex. More significantly, this increase in apoptotic cells in combination with CDDP is more pronounced using the scFv to the Tf receptor as the targeting ligand than using the Tf molecule itself. This increase correlates with transfection efficiency.
Example 7
scFv-immunoliposome-targeted wtp53 Gene Delivery and Expression In Vivo with Systemic Administration
[0046] To examine the ability of the anti-TfR scFv containing liposomes to deliver wtp53 specifically to tumor tissue in vivo, scFv-Lip(A)-p53-3′Ad ( FIG. 4 ) or the untargeted Lip(A)-p53-3′Ad ( FIG. 4 ) was injected intravenously into nude mice bearing JSQ-3 subcutaneous xenograft tumors. Two days after injection, the tumors were excised and protein isolated from liver and skin, as well as the tumor, for Western blot analysis (Xu L, et al., Hum. Gene Ther . (1997) 8:467-475). Equal amounts of protein (100 μg, as determined by concentration) were loaded in each lane. As shown in FIG. 2 , the tumor from the mouse systemically treated with the scFv-Lip(A)-p53-3′Ad complex, labeled scFv-Lip(A)-p53 in FIG. 2 , displayed a very intense p53 signal as well as the additional lower band indicative of a high level of expression of the exogenous wtp53, while only the lower expression of the endogenous mouse p53 is evident in both the skin and the liver. In contrast, as would be expected based upon our earlier results, a significantly lower level of exogenous p53 expression is evident in the tumor isolated from the untargeted Lip(A)-p53-3′Ad injected mouse, labeled Lip(A)-p53 in FIG. 2 . Therefore, the liposome complex targeted by our new and unique anti-TfR lpp-scFv ligand can clearly deliver exogenous genes selectively to the tumor in vivo. These results demonstrate the potential of this new way of efficiently targeting systemically delivered, cationic liposome complexes specifically to tumors in vivo.
Example 8
Construction and Purification of TfRscFv with a 3′Cysteine for Use in the Conjugation Method
[0047] In the absence of a lipid tag, another method was devised to attach the purified TfRscFv protein to the lipoplex. This approach entails the conjugation of the single chain protein to cationic liposomes via a reducible group such as a sulfhydryl group. In the preferred embodiment a cysteine residue is added at the 3′ end of the TfRscFv protein. Reduction of this cysteine results in a free sulfhydryl group which is capable of being conjugated to cationic liposomes, thus targeting the lipoplex to cells expressing the transferrin receptor. While the following examples use cysteine as the reducible group it is obvious that other similar reducing groups would also work with this method.
1. Construction
[0048] A. Construction of an Expression Vector Containing a 3′Cysteine with a Histidine Tag for Use in the Conjugation Method of Producing TfRscFv Immunoliposomes
[0049] As in Example 1, the VH-linker-Vκ scFv for the TfR was obtained from plasmid expression vector, pDFH2T-vecOK (described in Example 1). Using a 5′ primer (5′ GGCCCATGGAGGTGC AGCTGGTGG 3′ (SEQ ID NO:3)) for PCR amplification, an NcoI site was introduced into pDFH2T-vecOK. The nucleotide sequence for the cysteine residue as well as a NotI restriction site was introduced using a 3′ primer (5′ GGCGCGGCCGCGCATTTTATCTCCAGCTTG 3′ (SEQ ID NO:4)). The PCR product was cloned into NcoI and NotI sites of the commercial vector pET26b(+) (Novagen). This vector also contains, 5′ of the NcoI site, the pelB leader signal sequence. The presence of this sequence in the expression vector allows transport of the protein to the periplasmic space. To aid in purification of the protein, the pET26b(+) vector also contains a Histidine tag sequence 3′ of the NotI site ( FIG. 5 ).
[0050] B. Construction of an Expression Vector Containing a 3′ Cysteine without a Histidine Tag for Use in the Conjugation Method of Producing TfRscFv Immunoliposomes
[0051] For human use as a therapeutic delivery vehicle, it is preferable that the TfRscFv be produced without the Histidine tag. Therefore, the construct described in Example 8, section 1. A, was modified to eliminate this tag in the final protein product. To accomplish this, the same 5′ primer as described above (in Example 8, section 1. A) was used. However, a different 3′ primer was used. In addition to the nucleotide sequence for the cysteine residue and the NotI restriction site, this primer (5=GGCGCGGCCGCTCAGCATTTTATCTCCAGCTTG 3=(SEQ ID NO:5)), introduced a DNA stop codon adjacent to the cysteine sequence and before the NotI site ( FIG. 6 ). Thus, the protein product of this construct will not contain the His-tag.
[0052] C. Construction of an Expression Vector Containing a 3′Cysteine with a 5′CBD™Tag for Use in the Conjugation Method of Producing TfRscFv Immunoliposomes
[0053] A third alternative construct containing a cysteine residue for linkage to the cationic lipoplex using the conjugation method was also made. For this construct ( FIG. 7 ), the same two primers described above in Example 8, section 1. B, were used. Thus no His-tag would be present in the protein product. However, the PCR product of these reactions was cloned into a different vector, pET37b(+) (Novagen). This vector contains a cellulose binding domain tag (CBDθ-tag) and an S-tag, both 5′ of the NcoI site in the vector. The CBD-tag sequence encodes a cellulose binding domain derived from a microbial cellulase. Thus, the presence of this tag enables the use of cellulose-based supports for highly specific, low cost affinity purification of the protein product. The presence of the S-tag present in this construct allows for easy detection of the protein product on Western blots and for easy enzymatic quantitation of protein amounts.
[0000] 2. Purification of the TfRscFv containing the Cysteine Residue
[0054] The commercially available E. coli expression host BL21 (DE3), which contains the expressed lac repressor, was transformed with an expression vector (all three were used individually) described above in Example 8, section 1. A number of clones were selected and the ones that produced the best yield of TfRscFv were chosen. Purification of the protein from the construct described above in Example 8, section 1. A, with the histidine tag is given in detail as an example, although the same method is used for purification of the cysteine containing TfRscFv protein from all three constructs described in Example 8, section 1. The majority of the TfRscFv protein (approximately 90%) was found not to be soluble but to be contained within the inclusion bodies. Therefore, the TfRscFv containing the cysteine-linker was purified from the inclusion bodies as follows. A single clone was inoculated into 5-10 ml LB containing 50 μg/ml Kanamycin, and grown at 37° C., and 250 rpm to an OD 600 of 0.5B0.7 (4-5 hrs). 30 ml of the mini culture was pelleted, suspended in LB broth, added to 1 L LB containing 50 μg/ml Kanamycin and incubated at 37° C. and 250 rpm, to an OD 600 of 0.5B0.7 (4-5 hrs). To induce expression of the TfRscFv protein, IPTG at a final concentration of 1 mM was added to the culture at this time and incubation continued for an additional 4 hrs. This time was determined to yield the maximum level of protein expression. The bacterial cultures were then collected by centrifugation and lysed in 100 ml of cold 20 mM Tris-HCl, pH 7.5, containing 100 μg/ml lysozyme, at 30° C. for 15 minutes. The sample was sonicated at 10 watts for 5 minutes (in 30 second bursts) with cooling on ice. The inclusion bodies were isolated by centrifugation at 13,000 g for 15 minutes. The resulting pellet was washed three times in cold 20 mM Tris-HCl buffer, pH 7.5. The purity and quantity of the inclusion bodies were determined by SDS-polyacrylamide gel electrophoresis before solubilization.
[0055] The isolated inclusion bodies were dissolved in 100 mM Tris-HCl, pH 8.0 containing 6 M guanidine-HCl and 200 mM NaCl (6 M GuHCl buffer) and centrifuged at 12,300 g for 15 minutes to remove insoluble debris. 2-mercaptoethanol was added to the supernatant to a final concentration equal to approximately 50 molar fold of the protein concentration and the mixture incubated with rotation for 1 hour at room temperature. The presence of such a high concentration of guanidine-HCl and the reducing agent results in a totally unfolded protein. Refolding of the TfRscFv protein was accomplished by dialysis at 4° C. against decreasing concentrations of guanidine-HCl in the absence of 2-mercaptoethanol. Dialysis was performed for 24 hours each against the following concentrations of guanidine-HCl in 100 mM Tris-HCl, pH 8.0 and 200 mM NaCl: 6 M, 3 M, 2 M, 1 M and 0.5 M. The last dialysis was against three changes of just 100 mM Tris-HCl, pH 8.0 and 200 mM NaCl. The fourth dialysis solution (of 1 M guanidine-HCl) also contained 2 mM glutathione (oxidized form) and 500 mM L-arginine. These reagents allow the partially refolded protein to form the proper disulfide bonds to produce the correct protein conformation. The solution was clarified by centrifugation at 13000 g to remove aggregates. The sample was concentrated approximately 1.5 fold using the Centrplus centrifugal filter (Amicon) at 3000 g for 90 min. SDS-PAGE showed a single band of the solubilized cysteine containing TfRscFv with a molecular weight of approximately 28-30 kDa containing only minor contaminants ( FIG. 8 ).
Example 9
Preparation of scFv-Liposomes by the Conjugation Method
[0056] 1. Reduction of scFv
[0057] The purified TfRscFv was reduced by DTT to obtain monomer scFv-SH as follows: To scFv in HBS (10 mM HEPES, 150 mM NaCl, pH 7.4) was added 1 M DTT to a final concentration of 1-50 mM. After rotation at room temperature for 5-10 min, the protein was desalted on a 10-DG column (Bio-Rad). The free —SH group was measured by 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB, Ellman's reagent) (G. L. Ellman (1959) Arch. Biochem. Biophys. 82:70-77. P. W. Riddles, R. L. Blakeley, B. Zeruer (1993) Methods Enzymol. 91:49-60) and calculated as —SH/protein molar ratio, or number of free —SH per scFv molecule (Table 7). The results indicate that 1-10 mM DTT is appropriate for the scFv reduction.
[0000]
TABLE 7
Reduction of TfRscFv
DTT Concentration
(mM)
—SH/scFv molar ratio
0
0.15
1
0.45
10
1.94
20
2.26
50
3.03
2. Liposome Preparation
[0058] 4-(p-maleimidophenyl)butyrate-DOPE (MPB-DOPE) (Avanti Polar Lipids) is included in the seven liposome formulations described in Example 3, to a 5-8% molar of total lipids. The MPB-liposomes were prepared the same way as described in Example 3. Other liposome preparation methods can also be used to prepare the cationic liposomes. For example, the ethanol injection method modified from that described by Campbell M J ( Biotechniques 1995 June; 18(6):1027-32) was used successfully in the present invention. In brief, all lipids were solubilized in ethanol and mixed, injected into vortexing pure water of 50-60° C. with a Hamilton syringe. The solution was vortexed for a further 10-15 min. The final concentration was 1-2 mM total lipids. The ethanol injection method is faster, easier and more robust. 1 M HEPES, pH 7.5 (pH 7.0-8.0) was added to a final concentration of 10-20 mM. Since we have found that the maleimide group is not stable in aqueous solution with pH>7, the liposomes should be prepared in water (pH 5-6.5). The pH can be adjusted to 7.0-8.0 before linking to scFv-SH with 1 M HEPES buffer, pH 7.0-8.0, to facilitate the post-coating reaction.
[0000] 3. Preparation of scFv-Liposome-DNA Complexes
[0059] A. Pre-Linking Method
[0060] scFv-SH was added to MPB-liposome at a protein/lipid (w/w) ratio of 1/5-1/40, preferably 1/10-1/20. The solution was mixed by gentle rotation for 30 min at room temperature to yield scFv-Lip. The scFv-Lip was used without purification although it can be purified by Sepharose CL-4B column chromatography. Plasmid DNA was diluted in water and added to the scFv-Lip at a DNA/lipid (μg/nmol) ratio of 1/6-1/20, preferably 1/10-1/14. The solution was mixed well for 5-15 min by inversion several times to produce scFv-Lip-DNA complex. scFv-Lip-DNA was used without purification although it can be purified by Sepharose CL-4B column chromatography. 80-100% of the scFv was found to be conjugated to the liposome.
[0061] B. Post-Linking Method
[0062] Plasmid DNA was diluted in water and was added to the MPB-liposome at a DNA/lipid (μg/nmol) ratio of 1/6-1/20, preferably 1/10-1/14. The solution was mixed well for 5-15 min by inversion several times to produce an MPB-Lip-DNA complex. scFv-SH was then added to the complex at a protein/lipid (w/w) ratio of 1/5-1/40, preferably 1/10-1/20. The solution was mixed by gentle rotation for 30 min at room temperature, to produce the final scFv-Lip-DNA complex. The scFv-Lip-DNA was used without purification although it can be purified by Sepharose CL-4B column chromatography. 80-100% of the scFv was found to be conjugated to the liposome.
[0063] 4. For intravenous injection, a 50% dextrose solution was added to the scFv-Lip-DNA to a final concentration of 5%.
Example 10
Immunoreactivity of Cysteine Containing TfRscFv-Immunoliposomes by the ELISA Assay
[0064] This example provides the characterization of the anti-TfRscFv-immunoliposomes produced by the conjugation method of this invention with respect to their ability to bind to TfR(+) cells in vitro. Human squamous cell carcinoma of head and neck cell line JSQ-3 served as the TfR(+) target cells for these studies.
[0065] As previously described in Example 4, indirect cellular enzyme-linked immunosorbent assay (ELISA) was employed to determine the immunoreactivity of the TfRscFv before and after conjugation to liposomes. Confluent JSQ-3 cells in 96-well plates were fixed with 0.5% glutaraldehyde in PBS for 10 min at room temperature. The plate was blocked with 5% fetal bovine serum (FBS) in PBS at 30° C. for 30 min. The cysteine containing TfRscFv alone, this TfRscFv conjugated to cationic liposomes (TfRscFv-immunoliposomes) and untargeted liposomes were added to wells in triplicate. An anti-transferrin receptor monoclonal antibody (Hb21, obtained from David Fitzgerald, NIH) was used in one series of wells as a positive control. The plate was incubated at 4° C. overnight. The wells were washed three times with PBS, and an anti-His monoclonal antibody (Qiagen) was added to each well (except for those receiving the antibody positive control) in 3% FBS in PBS and incubated at 37° C. for 60 min. After three PBS washes, HRP-labeled goat-anti-mouse IgG (Sigma) diluted in 3% FBS was added to each well and incubated for 30 min at 37° C. The plate was washed three times with PBS and 100 μl substrate 0.4 mg/ml OPD in citrate phosphate buffer (Sigma) was added to each well. The color-development was stopped by adding 100 μl 2 M sulfuric acid to each well. The plate was read on an ELISA plate reader (Molecular Devices Corp.) at 490 nm.
[0066] Indirect cellular ELISA clearly demonstrated that the anti-TfR scFv containing a C-terminal cysteine maintained its immunoreactivity. The OD 490 values increased with increasing amounts of TfRscFv protein, rising from 0.060±0.0035 with 0.6 μg of protein, to 0.100±0.0038 at 1.5 μg and 0.132±0.0031 with 3 μg of TfRscFv. Moreover, this TfRscFv protein appears to have even greater binding activity than the parental Hb21 anti-transferrin receptor antibody used as a positive control. The OD 490 for the highest concentration of the Hb21 (100 μl) was approximately 2-4 fold less (0.033±0.0086).
[0067] The indirect cellular ELISA assay was also performed after the same TfRscFv protein was incorporated via the conjugation method of the invention (Example 9) into two different liposome complexes (Lip(A) and Lip(B)) to demonstrate the universality of this method with cationic liposomes. Both the pre- and post-linking conjugation methods of liposome preparation detailed in Example 9 were used. As shown in Table 8, the immunoreactivity of the TfRscFv prepared by the conjugation method is not lost through complexing to either of the two liposome compositions. This was true for both pre- and post-linking methods used to produce the immunoliposome complex. The TfRscFv-targeted lipoplexes also demonstrated binding to the cells. This binding was significantly higher than that of the liposome without the TfRscFv, suggesting that this binding is in fact mediated through the attachment of the TfRscFv to the transferrin receptor on the cells.
[0000]
TABLE 8
Binding of TfRscFv-immunoliposomes Prepared by
theConjugation Method to JSQ-3 Cells In Vitro*
DNA:Lipid
Ratio
OD 490
Lip(B)-DNA
1:10
0.088
TfRscFv-Lip(A)-DNA by Pre-
1:10
0.152 ± 0.016
TfRscFv-Lip(A)-DNA by Pre-
1:12
0.166 ± 0.009
TfRscFv-Lip(A)-DNA by Post-
1:12
0.168 ± 0.006
TfRscFv-Lip(B)-DNA by Pre-
1:12
0.139 ± 0.012
TfRscFv only
—
0.235
*ELISA, OD 490 , Mean ± SD (triplicate readings except for Lip(B)-DNA)
Pre- = Pre-linking Conjugation Method
Post- = Post-linking Conjugation Method
Example 11
Conjugated TfRscFv-immunoliposome Mediated Gene Transfection of Target Cells In Vitro
[0068] We determined the in vitro transfection efficiency of the TfRscFv-liposome complex, prepared by the conjugation method, in cells using the plasmid pLuc, which contains the firefly luciferase gene under control of the CMV promoter as the reporter gene. To demonstrate the universality of the TfRscFv as a targeting ligand, here also, as in Example 10, two separate liposome compositions (Lip(A) and Lip(B)) were conjugated to the TfRscFv protein. Human breast cancer cell line MDA-MB-435 and human squamous cell carcinoma of the head and neck cell line JSQ-3 were used in these studies. The in vitro transfection was performed in 24-well plates (Xu L, et al., Hum. Gene Ther . (1999) 10:2941-2952). The transfection solutions were added to the cells in the presence of 10% serum. 24 hr later the cells were washed and lysed to measure the luciferase activity and protein concentration. The results are expressed as 10 3 relative light units (RLU) per μg protein in the lysate, as shown in Tables 9A and 9B.
[0000]
TABLE 9A
Conjugated TfRscFv-immunoliposome Mediated
Transfection In Vitro #
Luciferase Activity
(×10 3 RLU/μg protein)
MDA-MB-435
JSQ-3
LipA
106
377
Tf-LipA
284
640
scFv-LipA*
560
1160
scFv-LipA**
660
1210
scFv-LipA (1/10) @
—
1315
scFv-LipA (1/20) @
—
751
# Mean of duplicates
*Containing 5% MPB-DOPE
**Containing 7% MPB-DOPE
@ Ratio of scFv/lipids (w/w)
[0000]
TABLE 9B
In Vitro Transfection Activity of Conjugated
TfRscFv-Immunoliposome-DNA Complexes Prepared
for Systemic Administration
Luciferase Activity
(×10 3 RLU/μg protein)
MDA-MB-435
JSQ-3
scFv-LipA-pLuc (pre-linking)*
58.4
675
scFv-LipA-pLuc (pre-linking)**
45.6
513
scFv-LipB-pLuc (pre-linking)*
51.4
415
scFv-LipA-pLuc (post-linking)*
58.1
856
scFv-LipA-pLuc (post-linking)**
45.3
343
scFv-LipB-pLuc (post-linking)*
47.2
237
*Containing 5% MPB-DOPE
**Containing 7% MPB-DOPE
[0069] The results show that the cysteine containing TfRscFv-immunoliposomes prepared by the conjugation method have very high transfection activity in vitro, 3-6 fold higher than the untargeted liposomes and 2-3 fold higher than the transferrin-targeted liposomes. This was true for both liposome compositions and both human tumor cell lines. Thus, they still retain their immunoreactivity and can bind to their target receptor. Based upon Table 9A, the scFv-liposomes can also be used as efficient gene transfection reagents in vitro, and are much more efficient than commercially available cationic liposomes (DOTAP/DOPE and DDAB/DOPE) and transferrin-liposomes. The TfRscFv-immunoliposomes disclosed in the present invention can be used for an efficient in vitro gene transfection kit useful for the transfection of mammalian cells with transferrin receptors.
[0070] The TfRscFv is a smaller molecule than transferrin itself. Thus, the resulting complex is more compact and more easily taken up by the cells giving a higher transfection efficiency.
[0071] These results are also advantageous for the use of the TfRscFv immunoliposome for systemic delivery for human use. The smaller size allows increased access to the tumor cells through the small capillaries. Most significantly, the TfRscFv is not a human blood product as is the Tf molecule. Therefore, the concerns and technical problems associated with the use of transferrin itself for human therapy are avoided.
Example 12
Conjugated TfRscFv-Immunoliposome Mediated Expression of Wild-type p53 in a Nude Mouse Xenograft Model Following Systemic Delivery
[0072] In this example the ability of the TfRscFv, produced by the conjugation method of this invention, to direct a lipoplex carrying the wild-type p53 (wtp53) gene preferentially to tumor cells in vivo after systemic delivery is demonstrated. To demonstrate the universality of the TfRscFv as a targeting ligand, here also, as in Example 10, two separate liposome compositions (Lip(A) and Lip(B)) were complexed to the cysteine-containing TfRscFv protein by the conjugation method. Only the pre-linking method of conjugation as detailed in Example 9 was used in this study. 2.5×10 6 MDA-MB-435 human breast cancer cells were subcutaneously injected into 4-6 wk old female athymic nude mice. 1.1×10 7 DU145 human prostate cancer cells suspended in Matrigel® collagen basement membrane (Collaborative Biomedical Products) were also subcutaneously injected into 4-6 week old female athymic nude mice and tumors were allowed to develop. Animals bearing tumors of between 50-200 mm 3 were used in the study (1 animal/sample tested). Conjugated TfRscFv immunoliposomes carrying the wtp53 gene, as well as untargeted Lip(B)-p53 and wtp53 naked DNA were intravenously injected into the tail vein of the animals. As an additional control, conjugated TfRscFv-Lip(A) carrying the empty vector in place of the p53 containing vector was also injected into a mouse. As described in Example 7, approximately 60 hours post-injection, the animals were sacrificed and the tumors, as well as the liver, were excised. Protein was isolated from the tissues and 100 μg of each sample (as determined by protein concentration assay) was run on a 10% polyacrylamide gel for Western blot analysis using an anti-p53 monoclonal antibody. In both of these tumor types the endogenous mouse and the exogenous human p53 migrate at the same position. The results here mirror those described in Example 7. As shown in FIG. 9 , both the DU145 and MDA-MB-435 tumors from the animals intravenously injected with the TfRscFv-Lip(A)-pCMVp53 lipoplex or the TfRscFv-Lip(B)-pCMVp53 lipoplex prepared by the conjugation method displayed a high level of expression of exogenous wtp53, as indicated by the intense p53 signal and an additional lower band, with the best expression in the DU145 tumors. While it appears that in both tumor types the Lip(A) composition was somewhat better than the Lip(B), both liposome compositions worked demonstrating the universality of this method. Only the endogenous mouse p53 protein was evident in the liver of these animals. In contrast, only the endogenous mouse p53 protein was evident in the tumors excised from the mice injected with the conjugated TfRscFv-Lip(B) carrying the empty vector or the naked wtp53 DNA. A small increase in p53 expression also was observed in the DU145 tumor with the untargeted Lip(B)-p53. Thus, the conjugated TfRscFv-immunoliposomes delivered the wtp53 gene preferentially to the tumors, as desired. It is also significant that this tumor targeting was evident in two different tumor types, indicating the general usefulness of the method of this invention. Therefore, the methods of this invention described in the preceding Examples generate a TfRscFv protein that not only retains its ability to bind to cationic liposomes but is still immunologically active preserving its ability to bind to the transferrin receptor in vitro and in vivo, thus fulfilling our objective of producing a tumor-specific, targeted immunoliposome for gene therapy.
[0073] While the invention has been disclosed in this patent application by reference to the details of preferred embodiments of the invention, it is to be understood that the disclosure is intended in an illustrative rather than in a limiting sense, as it is contemplated that modifications will readily occur to those skilled in the art, within the spirit of the invention and the scope of the appended claims.
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Nucleic acid-immunoliposome compositions useful as therapeutic agents are disclosed. These compositions preferably comprise (i) cationic liposomes, (ii) a single chain antibody fragment which binds to a transferrin receptor, and (iii) a nucleic acid encoding a wild type p53. These compositions target cells which express transferrin receptors, e.g., cancer cells. These compositions can be used therapeutically to treat persons or animals who have cancer, e.g., head and neck cancer, breast cancer or prostate cancer.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for the monitoring of the motion of a drive-operable, one or multiple part door body, particularly an overhead door, along the movement path between the open and closed position and for the interruption of this motion, particularly by switching off and over the drive in the event of an obstacle in the path of movement which the door body runs against with the following steps:
an actual course which really occurs and dependence on the movement path or the time of a physical operating value of the movement of the door body is recorded, and
an interruption signal for the interruption of the motion of the door body being monitored is generated if the currently recorded value of the actual course differs by a previously determined amount from the corresponding value of a nominal course with the nominal course on the basis of a physical operating value being recorded and stored at least once before the putting into operation of the door for an obstacle-free normal operation along the movement path or the time, and to a means to perform the method in accordance with a door drive, a measuring element to measure the movement path, a measuring element to measure a physical operating value of the door motion, a memory to store the nominal course and/or actual course determined by the measuring elements in dependence on the movement path or the time and a control unit to evaluate the nominal course and the actual course and to generate an interruption signal.
Such a method and such a means are known from EP-B1-0 083 947. The monitoring unit disclosed therein is based on the basic idea that the actual course of the required force to drive the door body over the movement path is compared continuously with the nominal course. If the difference between actual course and nominal course exceeds a previously fixed amount, an interruption signal is generated which switches off the door body drive or reverses its direction of movement. The nominal course is here recorded and stored at least once prior to the putting into operation of the door for an obstacle-free normal operation along the movement path.
Such a monitoring system possesses an improved hazard protection over other known monitoring systems such as electrical contacts positioned underneath yielding bulges. Nevertheless cases can still occur with such a monitoring means where the criterion to generate the interruption signal is not sufficiently sensitive. If the door body edge contacts soft obstacles, for example, the motion force for the movement of the door body increases more slowly than against a hard obstacle so that a longer period passes before the interruption signal is triggered. If, therefore, the edge of the door body laterally contacts, for example, the groin of person accidentally crossing the motion path during the movement of the door body, then is it possible that the interruption signal of the monitoring device will not be triggered early enough.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to monitor as sensitively as possible the motion of movement between the open position and the closed position of doors of the type in question for any deviation from normal operation.
Based on a method of the generic type this object is solved in accordance with the present invention by the steps of an actually occurring actual change of course dependent on the movement path or the time is determined by forming the derivation according to the movement path or the time for every recorded value of the actual course, and
an interruption signal for the interruption of the motion of the monitored door body is generated if the currently determined value of the actual change of course differs to a previously determined extent from the corresponding value of a nominal change of course with the nominal change of course being determined and stored at least once before the putting into operation of the door based on the nominal course. The solution in accordance with the invention consists of the fact that in addition to the known methods a derivation of the actual course of a physical operating value of the door movement is formed at each scanned point in accordance with the movement path and that an interruption signal is generated even if a criterion is not met in accordance with the derivation determined. The nominal course of the corresponding physical operating value is here recorded and stored at least once before the putting into operation of the door for an obstacle-free normal operation along the movement path.
The advantages achieved with the present invention comprise particularly the monitoring unit reacting equally sensitively when the door contracts hard objects and/or soft objects. This improvement can be achieved here with relatively low effort over a monitoring unit of the generic type.
Preferably, for the formation of the actual change of course and/or the nominal change of course the first derivation is formed according to the movement path or the time; however, higher derivations can also be used.
The difference value to be given, by which the actual change of course has to differ from the nominal change of course in order to signal the event of an obstacle, is, on the one hand, dependent on external influences such as wind influences, slight icing and similar and, on the other hand, it takes slight changes in the run resistance into account. In accordance with a preferred embodiment a fixed difference value is fixed beforehand over the total motion run, but in principle the difference value can, however, also be measured differently over the movement path, particularly to compensate for the different wind impairment depending on the motion path already laid back.
In principle, the nominal course and the actual course can be derived from different physical operating values of the forward movement, but preferably the same physical starting values will be evaluated for both values.
In accordance with a preferred embodiment the nominal course is only recorded and stored after the installation of the door on site and then the nominal change of course should be determined and also stored. In this way, the actually occurring operating relationships can be taken into account under normal conditions in a realistic manner with the actually prevailing environmental influences. As the operating relationships can change over time due to wear or similar, the nominal course can be recorded and stored again after certain operating intervals of the door and a new nominal change of course determined from this. It is naturally, however, also possible to give and store the nominal course at the time of manufacture depending on the type of door. The nominal change of course can also be determined and stored once, but it is also possible to have the nominal change of course determined again during operation for every movement of the door body on the basis of the nominal course.
The determination in dependence on the path of a physical operating value of the door body motion can be done in various ways. Preferably, the driving force of the door body is used as the basis with this being able to be determined in turn by a direct measurement of force or also by a measurement of torque. A preferred method of measuring the torque consists of determining the torsion angle between two coupling elements connected elastically to one another and positioned behind one another as part of the path of the driving force. However, it is also possible to monitor in a known fashion the performance of an electrical drive motor or the current supplied with a constantly applied voltage.
If the above measuring values of a physical operating value of the motion of a door body are recorded in dependence on the movement path, then it is necessary for this purpose that the movement path itself also be determined by a suitable measuring device. For this purpose, preferably a pulse generator is used which is also driven by the driving motor. In connection with two switch elements which detect the opening position and the closing position of the door body, the current position on the movement path can be determined with the pulse generator within the resolution precision of the pulses emitted.
In accordance with another preferred embodiment it is provided that the rate of motion of the door body is taken as a measure of a physical operating value of the motion. Here, the rate of motion is no longer recorded in dependence on the movement path but in dependence on the time. A course of speed for normal operation without any obstacles also recorded in dependence on the time serves as the nominal course. To measure the rate of motion a tachometer generator or also a pulse generator can be used which can be driven by the door drive. While the pulses emitted by the pulse generator have still to be derived into a frequency proportional to the speed, the tachometer generator already supplies a voltage proportional to the rate of motion of the door.
Another solution of the above task in accordance with the invention consists of a device to perform the method in accordance with the invention with the control unit possessing a derivative element which generates a nominal change of course from the nominal course and/or an actual change of course from the nominal course each in dependence on the movement path or the time, the nominal change of course and/or the actual change of course can be stored in the memory and the nominal change of course and the actual change of course can be evaluated by the control unit.
In accordance with its basic design, the device comprises a door drive, a measuring element to measure the movement path, a measuring element to measure a physical operating value of the door movement, a control unit with memories for the measuring values and a derivative element.
In accordance with a preferred embodiment the control unit comprises a microcontroller in which corresponding memories and A/D converters have already been integrated. Preferably, the derivative element is also implemented on the microcontroller in the form of a software logic. However, it is also feasible that the derivative element comprises an analog derivator whose signal is also supplied to an A/D converter. In any case, the derivative element must be designed in such a way that the current derivation of the input signal in question is determined reliably independent of momentary noise interference.
In accordance with another preferred embodiment the door drive comprises an electrical motor. The power of the electrical motor supplied can here be taken directly as the measure for a physical operating value of the door motion. With a constantly supplied voltage, the current supplied to the electrical motor can also serve as the basis for a physical operating value with the current being measured then approaching a measure for the moment given by the electrical motor.
In accordance with another preferred embodiment it is provided that the interruption signal generated by the control unit results in a switching off of the electrical motor. However, it is also possible that the direction of drive of the door drive will reverse as a result of the interruption signal which can be done with a suitable electrical motor by reversing the polarity of the supply voltage or also by a suitable gear.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details and advantages of the invention are described in more detail by means of an embodiment shown in the drawing where:
FIG. 1 is a schematic representation of a garage door movable overhead with a block diagram of the monitoring system in accordance with the invention, and
FIG. 2a is a front view of a schematic representation of a pulse generator on an elastic coupling.
FIG. 2b is a side view of the schematic representation of a pulse generator on an elastic coupling.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The garage door from FIG. 1 possesses two vertical braces 1 to whose top end two rails 2 connect in which the door body 3 is guided. The door body 3 is further hinged to the braces 1 with a connecting rod not shown so that the door body can be opened and closed with an overhead movement. In addition, equalizing springs are provided which largely compensate the door body's own weight during the movement and which hold the door body in its defined end positions. The drive system designated with number 4 consists in total of a drag-chain drive with a drag chain 5, to which the door body 3 is hinged and which is guided over the turn pulley 6 and over a drive pulley (not shown). The drive pulley is located in the drive unit 7 and is driven by the electrical motor 9 via a gear. Also driven by the electrical motor 9 is an impulse generator 8 which is mounted on an elastic coupling and which emits a pulse after every certain angle of rotation.
The whole system is controlled by the control unit 10 which consists of a microcontroller with an integrated memory and A/D converters. The output signal of the control unit 10 is supplied to an amplifier 11 which supplies the required power to the electrical motor 9 via a current measuring element 12. The input values of the control unit include the measuring values 8a and 12a, the switch signals 13a and 14a and input signals 15 (not specified in any detail) which can include signals of an operating unit or also a voltage supply.
The signal 8a of the pulse generator is evaluated by the control unit in connection with signals from switch elements 13 and 14. Here the switch elements are actuated by the door body 3 in its end positions, that is in the vertical and in the horizontal position in each case. Signals 13a and 14a therefore each serve as start/stop signals in order to ensure a reliable upward integration of the signal 8a.
FIGS. 2a and 2b show a possible embodiment of the pulse generator 8. In an axial cross-section and in a radial section a coupling is shown which is provided between the driving wheel of the drag chain 5 and the outlet of the drive motor 9. The driven coupling half 20 is designed as a rotating, elastic coupling element with a radial intermediate layer between teeth and hub, for example in the form of a rubber ring 21. The output coupling half 22 possesses on its radial circumference teeth 23 which are sensed by the inductive generator 24. When the coupling turns, the inductive generator 24 then emits corresponding pulses due to the periodic change in the inductance.
With such an elastic coupling it is also possible to determine the torque given by the electrical motor 9 by measuring the angle of torsion between the driven coupling half 20 and the output coupling half 22. In the present embodiment this is, however, done by the current measuring element 12 which measures the current supplied to the electrical motor. The evaluation of the measuring signals 8a and 12a is described here in the following:
Before the door drive is put into operation the nominal course of the motor current for obstacle-free normal operation is recorded in dependence on the movement path. For this purpose, the signals 8a and 12a are read into the microcontroller via A/D converters at identical scan times and stored in such a way that an allocation of values of identical times is possible. Together with the control program of the drive control the nominal course thus recorded is stored in the EPROM so that the values can be reloaded into the RAM at every reset of the microcontroller.
During an opening or closing movement of the door body an actual course of the motor current according to the nominal course is recorded in dependence on the movement path. For each actual value recorded a calculation process is performed before the recording of the next actual value, that is within one scan period, which calculation process checks whether any unpermitted differences from the nominal course exist and whether accordingly an interruption signal has to be generated.
For this purpose, first each actual value recorded is compared to the corresponding nominal value for identical values of the movement path. If the actual value differs from the nominal value by a previously determined amount, then an interruption signal is generated by the microcontroller which signal results in a reversal of the drive direction of the door body.
If, in contrast, the actual course is within a permitted range, then in a next step for the currently recorded actual value the derivation is formed in dependence on the movement path. For this purpose, different methods are feasible, the simplest consists of the forming of a difference between the currently recorded actual value and the previously recorded actual value. If the actual values are particularly loaded with noise, then a smoothing of the previous values may be necessary prior to forming the difference. To do this, a certain number of previously recorded actual values are interpolated with a given function before the derivation is then formed from this interpolated function. The currently determined derivation is included in an actual change of course which is compared with a nominal change of course. This nominal change of course was also determined and stored in accordance with the method just described prior to the putting into operation based on the already recorded nominal course. If the actual change value differs from the nominal change value by a previously determined amount, then an interruption signal is generated which in the results in a reversal of the drive direction of the door body.
In accordance with the method described above, the already known criterion between nominal course and actual course is therefore supplemented by an additional criterion between nominal change of course and actual change of course which allows a more exact evaluation for the generation of an interruption signal. Of course, in addition to the derivation criterion other further criteria are feasible, in particular the nominal course can be compared more and more exactly with the actual course by forming further derivations. The limit here is formed by the already mentioned noise behavior of the two signals with a minimum tolerance width being required between the actual course and the nominal course so that the interruption signal is not triggered when not desired.
In addition to the method described for the recording of the nominal and actual courses in dependence on the movement path, it is besides also possible to record the actual and nominal courses in dependence on the time. The requirement for this is that the course of movement of the door body does not change over time. For this purpose it must be ensured that friction influences and any other interference influences can be neglected. This can be taken into account in a limited fashion by the nominal course being recorded again after regular maintenance intervals. If the interference influences can accordingly be neglected, then it is also possible to dispense with the current sensor 12 by having the rate of speed of the door body being determined over time from the signal of the pulse generator 8.
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A method for monitoring motion of a drive-operable door body between open d closed positions. To monitor movement as sensitively as possible, an actually occurring course of movement is compared with a previously fixed nominal course. A signal for interrupting movement is generated when the nominal course and the actual course, and/or one of the derivations of these, differ from one another by a previously fixed amount.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to and incorporates herein by reference U.S. Provisional Patent Application Ser. No. 61/491,190 filed on May 28, 2011.
BACKGROUND OF INVENTION
[0002] The present invention relates to a pressure relief system for footwear that relieves plantar pressures via an anatomical sock liner which is engineered with a shape designed to achieve a high amount of deflection when compressed without becoming stiff.
[0003] Many footwear brands market shoes as “comfortable,” and there are many footwear products in the marketplace which claim to deliver on comfort. However, there is a misconception in the footwear industry as to what the definition of comfort actually is. Indeed, there is no universal standard for “comfort.” Consumers have a hard time understanding precisely what comfort means, and how it is designed into the footwear they are buying.
[0004] Most articles of footwear are designed for the masses to wear. However, the resulting fit and comfort experience will be different for everyone wearing a single shoe design, and satisfying such a broad range in population is very difficult.
[0005] Most non-athletic shoes today contain hard materials, flatter interior foot contact surfaces and/or are made with low density foams that easily bottom out (i.e., which fully compress too quickly, and therefore fail to provide sufficient cushioning). These constructions lead to higher than desired interior pressures created against the plantar surface of the foot, which eventually lead to discomfort. Essentially, most non-athletic shoes are build to be too hard and stiff.
[0006] Athletic shoes, on the other hand, are generally made with softer cushioning materials designed to provide shock absorption during high impact activities. However, these designs are not as comfortable when used for everyday wear, because the cushioning materials are tuned for the high-impact performance conditions, rather than the lower impact casual situations.
[0007] In order to correct for these design deficiencies in athletic and non-athletic shoes, many consumers buy after-market insoles in an attempt to compensate for a shoe's short comings. However, many of today's after-market insoles marketed for improving comfort or relieving foot problems cause fit and comfort compromises because these insoles were not designed holistically together with the shoes they are to be put inside. The comfort potential of these insoles is often offset by the functional deficits of the footwear into which they are installed (hard, stiff, inflexible, heavy, etc.).
[0008] Numerous combinations of after-market insoles and shoe constructions have been used in shoes in attempts to provide comfort. In most cases, layers of foam or other similar materials are added to the sole construction to create the initial perception of comfort, but such constructions typically lose their effect after a short time. Many actually end up creating discomfort. Beneath the soft foams are often hard, stiff structural components. Insoles, sock liners and bottom shapes generally don't match the plantar surface of a person's foot. When the shapes of the insole and/or the sock liner don't match the plantar surface of a wearer's foot, such shoe interiors have minimal/low arch and heel contact with the foot. When combined with increased pressures encountered when toeing off, inflexible soles create pressures on the plantar area of the foot up to four times higher as compared to standing still.
[0009] This invention improves upon the comfort benefits delivered in footwear by focusing on a specific comfort dimension: plantar pressure relief.
[0010] Specific advantages and features of the present invention will be apparent from the attached drawings and the description of an illustrative embodiment of the present invention.
SUMMARY OF INVENTION
[0011] A shoe is designed utilizing a last having a shape and volume that reflect the thickness of an internal sock liner, and a shoe interior made specifically for inclusion of this sock liner. The sock liner itself contains an anatomically shaped foot bed surface with a cupped heel, contoured arch, radiused forepart and beveled toe area. The sock liner material specifications and thicknesses are engineered or “tuned” to have a high amount of deflection when compressed without getting “stiff.”
[0012] The sock liner of the present invention includes a raised area in the midfoot region and a recessed area located in the hind foot or heel region. The raised area is positioned to underlie the medial arch of the wearer's foot and the recessed area is positioned to underlie the heel of the wearer's foot. The recessed area is defined by the peripheral edges formed around the hind foot region from the medial side to the lateral side of the heel. The peripheral edge in the hind foot region forms a raised portion where it wraps around the heel of the wearer's foot. The anatomically shaped and formed sock liner reflects the natural shapes of the human foot. The shaped plantar surface topography maximizes surface contact with the wearer's foot and increases comfort.
[0013] In order to “tune” the sock liner material dimensions, design and specifications are engineered through an analysis of: 1) the desired deflection ranges, which are generally between 40-70% of the overall thickness of the sock liner; 2) the target loading ranges being designed for active wearing occasions, which are generally between 30-70 pounds, depending on gender and/or foot size; 3) the physical properties of the materials to be used (as specified below); 4) the desired pressure range targets for various plantar areas of the foot, which are generally below 40 pounds per square inch; and 5) anatomical shapes that create additional surface contact with the foot. The deflection of the sock liner is preferably approximately 25% while standing and approximately 50% while running or walking.
[0014] Unlike most shoes designed for “extra comfort,” the exterior of the shoe can be designed for any wearing occasion and/or end use. The shoe may be designed with less midsole thickness than conventional shoes, in order to compensate for added thickness of the sock liner. In this way, the system can be applied to any type of footwear category or end use as long as there is adequate sockliner thickness available. Athletic shoes (running, training, walking), sandals, work shoes (duty/service industries), and casual shoes may all incorporate such sock liners. Consideration is given for the exterior shoe sole design to complement the functionality designed for this system, such as: anatomically correct flex location; and material thicknesses and specifications that do not contribute to inflexibility, thus increasing pressure against the foot's plantar surface by the poor shoe design/materials.
[0015] Preferably, materials may include polyurethane, SEBS foam, EVA, rubber sponge, latex, and/or co-polymer blended foams. The materials preferably have a hardness of between 10 C and 70 C on the Asker C scale, with a material density of between 0.05 g/cc and 0.60 g/cc. The thickness of the sock liner (measured at the center of the heel and center of the forefoot—not wall heights) varies by shoe design. However, the thickness generally ranges from 5 mm to 50 mm at the heel center, and from 3 mm to 35 mm in the forefoot center.
[0016] The overall design of a sock liner according to the present invention should increase contact between the foot and sock liner surface—especially during weight bearing—preferably at or above 75% rate of surface contact between the foot and sock liner. The sock liner also improves pressure re-distribution from peak pressure areas, and spreads the pressure across the entire plantar surface area such that preferably no single location experiences a pressure above 40 psi. In so doing, cushioning and shock absorption protection should prevent stresses above 10 Gs.
[0017] In order to reduce such pressures exerted by the shoe against the plantar surface of the foot, the sock liner surface yields and deflects under the foot without a significant increase of hardness and stiffness of the sock liner, which could create discomfort. Such deflection can also increase foot stimulation through more utilization of bones, tendons, muscles during foot-strike. The deflection can also promote a wearer's natural gait/foot-strike during walking, by straightening the wearer's center of force trajectory during foot-strike. Further, a flexibility improvement may be realized where less foot force is required to bend a shoe across the foot's flex area. Preferably below about 5 pounds of force is required to bend flex the shoe at such flex areas.
[0018] The sock liners may be removable, and as noted above, either polyurethane or EVA materials may be utilized (both as 100% standalone sock liners, i.e., not combined). Alternatively, non-removable sock liner foot beds may be utilized in an open sandal or other type of shoe. Alternative embodiments may utilize: “gel” as either a shock absorber or comfort element on the sock liner; the addition of flex grooves on the bottom of the sock liner; a visible sock liner, either through a window of the upper or midsole; multiple foam types in one sock liner unit; a sockliner made via injection molding, compression molding, open-pouring or die-cut/cementing; a closed shoe with a non-removable sock liner; additives to provide anti-microbial, anti-hydrolysis, and/or anti-UV enhancements and/or to strengthen the cell structure; a sock liner which can be combined with an insole layer (above or below) to reduce thickness/weight and/or can be designed as a “midsole” unit that is dropped into a unit sole or laminated with an outsole layer in a stitch-out construction.
[0019] These and other objects and advantages of the present invention will become more apparent to those skilled in the art after considering the following detailed specification taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1 is a three dimensional perspective view of a last, the sock liner of the present invention, and an outsole designed with a recess to receive the sock liner's added thickness.
[0021] FIG. 2 is a typical material “Force/Compression” chart which illustrates a typical relationship between force (in pounds) and percent deflection of the material.
[0022] FIGS. 3A and 3B are a bottom plan view and side elevational view, respectively, of an exemplary sock liner.
[0023] FIGS. 4A , 4 B and 4 C are schematics of a right elevational view, a top plan view and a left elevational view, respectively, of a sock liner according to the present invention.
[0024] FIGS. 5A , 5 B and 5 B are cross sectional schematic views, taken along the horizontal lines of FIGS. 4A-4C at the ball, arch and heel of the sock liner, respectively.
[0025] FIG. 6A is an exemplary pressure test-image of a sock liner according to the present invention.
[0026] FIG. 6B is an exemplary pressure test image of a prior art sock liner.
[0027] It should be understood that the present drawings are not necessarily to scale and that the present embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted. It should also be understood that the present invention is not necessarily limited to the particular embodiments illustrated herein. Like numbers utilized throughout the various Figures designate like or similar parts or structure.
DETAILED DESCRIPTION
[0028] In the present invention, a sock liner is provided which improves comfort and can be built into any type of shoe. As shown in FIG. 1 , a shoe will include an upper or last 5 , the sock liner 10 and the midsole/outsole 20 (“outsole”). Outsole 20 is positioned on the underside of the shoe for engagement with a walking surface such as the ground, sidewalk, floor or other supporting surface. Preferably, the top surface of the outsole is shaped to conform to the bottom surface of the sock liner 10 . The thickness of outsole 20 may be less than conventional shoes in order to compensate for the added thickness of the sock liner 10 . The outsole 20 may be constructed of any suitable material for example, leather, elastomer, polymer, a composite thereof or the like depending upon the type of shoe desired. The sock liner 10 and outsole 20 may be secured to one another using any suitable attachment means including cement, adhesives, glue, welt and direct attachment constructions
[0029] For ease of reference herein, the foot of a human may be considered to have three regions: the forefoot region (area adjacent the toes), the midfoot region (area adjacent the arch), and the hind foot region (area adjacent the heel). As shown in FIGS. 3A , 3 B, 4 A- 4 C and 5 A- 5 C, the sock liner 10 similarly includes three regions substantially underlying the above-referenced corresponding three regions of the wearer's foot: the forefoot region 16 of the sock liner 10 , the midfoot region 14 of the sock liner 10 , and the hind foot region 12 of the sock liner 10 . It should be understood, however, that the boundaries between the forefoot, midfoot and hind foot areas are not precise and that these terms should be interpreted loosely and with a great deal of flexibility. The ball of the foot is generally the area of the foot at the juncture between the metatarsal bones and the phalange bones.
[0030] The midfoot region 14 of sock liner 10 is raised to underlie the medial arch of the wearer's foot, while the hind foot region 12 is cupped to underlie the heel of the wearer's foot. The hind foot region 12 is defined by the peripheral edges 13 formed around the hind foot region 12 from the medial side to the lateral side of the heel. The peripheral edge 13 in the hind foot region 12 forms a raised portion where it wraps around the heel of the wearer's foot. The forefoot region 16 includes a radiused forepart and a beveled toe area. The anatomically shaped and formed sock liner is thereby designed to reflect the natural shapes of the human foot. The shaped plantar surface topography maximizes surface contact with the wearer's foot and increases comfort.
[0031] The sock liner material specifications and thicknesses are engineered or “tuned” to have a high amount of deflection when compressed without getting “stiff.” In order to “tune” the sock liner 10 material dimensions, design and specifications are engineered through an analysis of: a) the desired deflection ranges, which are generally between 40-70% of the overall thickness of the sock liner and preferably about 25% while standing and about 50% while running or walking; b) the target loading ranges being designed for active wearing occasions, which are generally between 30-70 pounds, depending on gender and/or foot size; c) the physical properties of the materials to be used (as specified below); d) the desired pressure range targets for various plantar areas of the foot, which are generally below 40 pounds per square inch; and e) anatomical shapes that create additional surface contact with the foot.
[0032] An exemplary chart of the relationship between pressures exerted on the sock liner 10 as compared to the deflection of the sock liner 10 is shown in FIG. 2 . As can be seen, as the force (in pounds per square inch) increases, so too does the deflection of the sock liner 10 . At about 70 psi, which as noted above is at the high end of the target loading range for an active wearing occasion (e.g., running), the deflection is shown to be approximately 55%—close to the desired 50% deflection discussed above. Further, at about 25 psi, which is below the low end target loading range for an active wearing occasion (e.g., walking or standing), the deflection is close to 25%—approximately the desired deflection discussed above. Thus, the exemplary specimen tested in FIG. 2 is appropriately “tuned” to provide optimal pressure relief according to the present invention. It is noted that FIG. 2 illustrates the measured characteristics of an exemplary material of an exemplary thickness. Other materials would need to be “tuned” to determine the proper thicknesses for achieving improved pressure relief.
[0033] Preferably, materials for the sock liner 10 may include polyurethane, SEBS foam, EVA, rubber sponge, latex, and/or co-polymer blended foams. The materials preferably have a hardness of between 10 C and 70 C on the Asker C scale, with a material density of between 0.05 g/cc and 0.60 g/cc. The thickness of the sock liner 10 (measured at the center of the heel 12 and center of the forefoot 16 —not wall heights) varies by shoe design. However, the thickness generally ranges from 5 mm to 50 mm at the heel center 12 , and from 3 mm to 35 mm in the forefoot center 16 .
[0034] The overall design of a sock liner 10 according to the present invention should increase contact between the foot and sock liner 10 —especially during weight bearing—preferably at or above 75% rate of surface contact between the foot and sock liner 10 . The sock liner 10 also improves pressure re-distribution from peak pressure areas, and spreads the pressure across the entire plantar surface area such that preferably no single location experiences a pressure above 40 psi. In so doing, cushioning and shock absorption protection should prevent stresses above 10 Gs. This can be seen in FIG. 6A as compared to 6 B. FIG. 6A illustrates an exemplary foot pressure diagram of a foot utilizing the sock liner 10 of the present invention, in which the hind foot portion 12 and forefoot portion 16 of the foot experience a pressure level below the target threshold of 40 psi (shown by the blue image color). In FIG. 6B , which illustrates a prior art foot pressure diagram without an improved sock liner 10 , the forefoot region 16 , and the hind foot region 12 experience a pressure level well above (2-3 times) the target threshold of 40 psi (shown by the red image color). Thus, by tuning the thickness and shape of the material used in the sock liner 10 construction, the deflection has been tuned such that the forces experienced by the foot have been greatly reduced to below 40 psi from over 100 psi.
[0035] The sock liners 10 may be removable, and as noted above, or they may be formed from polyurethane or EVA materials (both as 100% standalone sock liners, i.e., not combined). Alternatively, non-removable sock liner 10 foot beds may be utilized in an open sandal or other type of shoe. Alternative embodiments may utilize: “gel” as either a shock absorber or comfort element on the sock liner 10 ; the addition of flex grooves on the bottom of the sock liner 10 ; a visible sock liner 10 , either through a window of the upper or outsole 20 ; multiple foam types in one sock liner unit 10 ; a sock liner 10 made via injection molding, compression molding, open-pouring or die-cut/cementing; a closed shoe with a non-removable sock liner 10 ; additives to provide anti-microbial, anti-hydrolysis, and/or anti-UV enhancements and/or to strengthen the cell structure; or a sock liner 10 which can be combined with an insole layer (above or below) to reduce thickness/weight and/or can be designed as a “midsole” unit that is dropped into a unit sole or laminated with an outsole layer in a stitch-out construction.
[0036] Further, the overall dimensions of the present sockliner 10 and outsole 20 as well as the specific shape and configuration of the various sections thereof are also subject to wide variations and may be sized and shaped into a wide variety of different sizes and configurations so as to be compatible with the size and shape of the particular footwear onto which the present structures may be mounted, or to conform with any space limitations associated therewith out impairing the teachings and practice of the present invention.
[0037] It is also understood that various modifications may be made to all of the various embodiments without departing from the spirit and scope of the present invention.
[0038] Thus, there has been shown and described several embodiments of an anatomical sock liner system. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present invention will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.
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A shoe having a last which includes a shape and volume that reflects the thickness of an internal sock liner, and a shoe interior made specifically for inclusion of the sock liner. The sock liner itself includes an anatomically shaped foot bed surface with a cupped heel, contoured arch, radiused forepart and beveled toe area. The sock liner material specifications and thicknesses are engineered or tuned to have a high amount of deflection when compressed without getting stiff.
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BACKGROUND OF THE INVENTION
This invention relates generally to controls for hydraulic power systems and more specifically to directional control valves that selectively effect automatic leveling of a bucket on the front end of a loader or similar device during movement of the boom arm to which the bucket is attached.
It is conventional practice to provide a hydraulic cylinder and separate control valve for manipulating the bucket of a front end loader and a second cylinder and companion valve for aiding in raising and lowering the boom of a loader. In the absence of any self-leveling function, it is necessary for the operator of the loader to operate both valves, one with each hand, to maintain the bucket level while raising the boom. This operation is not only difficult but also requires the strict attention of the operator. The advantages of a self-leveling system are obvious and there have been numerous types of systems on the market for many years.
One of the more common methods, such as shown in U.S. Pat. No. 3,987,920 to Parquet, is a mechanical linkage tied to the frame of the loader which tilts the bucket, maintaining it level as the boom is raised or lowered.
Another common method, which is strictly hydraulic, is illustrated in U.S. Pat. No. 3,251,277 to Stacey. In this patent the fluid displaced from the boom cylinder is directed to the bucket cylinder by actuation of the boom spool alone. This type of system requires a matching of volumes so that the volume displacement from the boom cylinder will extend the bucket cylinder the precise distance to hold the bucket level as the boom is raised. This type of system is more expensive and bulky since it requires an unduly large bucket cylinder.
Another method is illustrated in U.S. Pat. No. 3,811,587 to Seaberg which utilizes a pair of hydraulic motors mechanically tied together with the larger motor located in the boom cylinder circuit while the smaller motor is located in the bucket circuit. As flow passes through the boom circuit, a proportionally smaller flow is forced through the bucket circuit.
Another self-leveling system is shown in U.S. Pat. No. 3,563,137 to Graber wherein the flow exiting the boom cylinder passes through a flow divider, dumping a portion to drain while directing the remaining portion to the bucket cylinder to maintain a level condition while raising the boom.
In the last mentioned patent, the excess oil is removed from the self-leveling circuit by a proportional flow divider dumping to drain, however, such a system can only be used in a conventional parallel circuit as distinguished from a series circuit. A parallel circuit, as illustrated in the last mentioned patent, provides a source of pump pressure to each valve spool in a parallel path. A series system such as U.S. Pat. No. 3,251,277 to Stacey provides a pump power passage in series through the particular valve in the system. In a series type valve, if an upstream valve is moved to an operative position, there is no pump pressure to the remaining downstream valves since the power passages are in series.
Series type valves are normally not adaptable to a self-leveling function with the exception of the last mentioned patent to Stacey wherein the boom cylinder is located downstream from the bucket cylinder.
SUMMARY OF THE INVENTION
In the present invention which is a series circuit, a flow divider is utilized in the boom discharge flow path with a portion going to the bucket cylinder while the remaining flow passes back to the valve to the boom return motor port. This last mentioned flow through the boom return port provides downstream oil for the bucket cylinder if the operator attempts to override the self-leveling function while the boom cylinder is moving. The present invention gives a downstream valve in a series circuit the added capacity of functioning during the movement of the blocking upstream valve.
It is therefore the principal object of the present invention to provide a series type self-leveling system that directs only the necessary portion of the boom-displaced fluid to actuate the bucket cylinder and maintain a level condition while still allowing the bucket cylinder to override the self-leveling function if desired.
Another object of the present invention is to provide a series type control valve assembly including separate valves for controlling boom and bucket cylinders and a flow divider for directing a portion of fluid returning from the boom cylinder into the bucket cylinder so as to provide an automatic self-leveling function.
Another object of the present invention is to provide a self-leveling system which is simple in design and less expensive than parallel systems.
Another object of the present invention is to provide an inexpensive flow divider valve which can be plumbed into a conventional non-self-leveling system so as to achieve automatic self-leveling.
A further object of the present invention is to provide a self-leveling system which utilizes the same directional control valve as non-self-leveling systems.
Other object and advantages of the present invention are described in or will become apparent from the following detailed description and accompanying drawings of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a partially schematic representation of the hydraulic controls for a front end loader including longitudinal sectional views of the control valves with the boom and bucket valves in neutral position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawing, the overall self-leveling system is generally referred to by reference numeral 10. The system includes boom and bucket cylinders 12 and 14, respectively, which are controlled by boom and bucket directional control valves 11 and 13. Boom 15, which can be of many types, is pivotally mounted to the base frame member 17 of the loader while bucket 16 is attached to the end of boom 15 and bucket cylinder 14. Positioned between the control valves 11 and 13 and the boom and bucket cylinders 12 and 14, respectively, is a flow divider valve 20, as seen in the drawing. Boom and bucket valves 11 and 13 are located in a common valve body 18 in a series type flow path.
Control valves 11 and 13 are supplied pump pressure from pump 22 through inlet cavity 24. Connected with pump inlet cavity 24 is a conventional system relief valve 26 which when the system pressure is exceeded in cavity 24, relief valve 26 opens dumping pressure into reservoir cavity 30.
Boom valve spool 28 is positioned in a bore 29 which passes through valve body 18. From left to right, bore 29 first intersects reservoir cavity 30, return cavity 32, motor port cavity 34, power passage 36, pump inlet cavity 24, open center passage 38, power passage 40, motor port cavity 42, return cavity 32 and reservoir cavity 30. Power passages 36 and 40 are always open to pump inlet cavity 24 via passages 98 (symbolically shown). Attached to the right end of spool 28 is a conventional centering spring mechanism 44 which returns the valve spool to its neutral position as indicated in the drawing. Bucket valve spool 46 is positioned in a bore 47 which also passes through valve body 18. Bucket spool bore 47, from left to right, first intersects reservoir cavity 30, motor port cavity 48, power passage 50, open center cavity 54, downstream open center cavity 56, power passage 58, motor port cavity 60 and reservoir cavity 30. Power passages 50 and 58 are always open to open-center cavity 54 via passages 99 (symbolically shown). U-shaped reservoir cavity 30 drains to reservoir 62 at all times regardless of the positions of valve spools 28 and 46. Attached to the right end of valve spool 46 is a common centering spring 64 covered by a conventional vented cap 66.
Boom valve spool 28 includes, from left to right, valve spool lands 68, 70, 72 and 74, while bucket valve spool 46 includes valve spool lands 76, 78, 80 and 82, respectively.
Flow divider valve 20 includes an inlet cavity 84 which supplies a shuttle spool 85 through a pair of lateral openings 86 in the center of the spool. Located in the left and right ends, respectively, of spool 85 are fixed orifices 87 and 88 which are sized to create whatever flow proportion is desired. Shuttle spool 85 is slidably positioned in a bore which intersects boom motor port cavity 89 on its left end and bucket motor port cavity 90 on its right end. In a static condition, spring 94 urges spool 85 against a stop 83, threaded into the body of valve 20. The tapered ends of shuttle spool 85 function as variable orifices governed by the pressure drop across fixed orifices 87 and 88, respectively. A detailed description of the function of shuttle spool 85 is given in U.S. Pat. No. 3,563,137, mentioned above.
The divided flow from flow divider valve 20 is split into two flow paths, with the first exiting boom motor port cavity 89 to boom motor port 42, and the second flow path exiting cavity 90 across check valve 91 to bucket motor port 60.
Also located in flow divider valve 20 is an unloading valve spool 92 which in the absence of pressure in cavity 90 is held in a closed position by spring 93, as shown in the drawing.
The self-leveling system 10 of the present invention would typically be used on a front end loader with a series type hydraulic system, as distinguished from the more complex load-responsive or other type variable flow systems.
The boom and bucket control valves 11 and 13, are conventional valves normally used in a more basic system which does not self-level. In such a system, the boom and bucket valves 11 and 13 would be connected only to their respective cylinders 12 and 14.
OPERATION
With boom and bucket spools 28 and 46 in their neutral positions as indicated in the drawing, there is no pressure build-up in inlet cavity 24 since the pump flow freely passes through open center passages 38, 54 and 56 back to reservoir 62. If it is the intent of the operator to raise the boom 15 while maintaining the bucket 16 in a level position; boom valve spool 28 is moved to the right to the raised position, as indicated at the left end of the spool 28. In the raise position, spool land 70 blocks flow through open center passage 38 causing pressure to build in inlet cavity 24 while the left edge of land 70 opens power passage 36 to motor port 34 (via passage 98) allowing pump pressure to enter the cap end of boom cylinder 12. As the boom begins to raise, the discharge flow from the rod end of cylinder 12 enters inlet cavity 84 of the flow divider valve 20. From cavity 84, fluid enters the center of shuttle spool 85 through lateral openings 86 and exits in a split path through the two fixed orifices 87 and 88 at the opposite ends of the spool 85. Since the shuttle spool 85 is initially located in its most rightwardly position against stop 83, due to the force of spring 94, the initial flow will all be across orifice 87. However, as soon as flow begins across orifice 87, the spool will shift leftwardly due to the imbalance of forces acting on the opposite ends of the spool caused by a pressure drop across orifice 87, and allow flow to begin across orifice 88, into cavity 90. Regardless of the amount of flow into the divider valve or the pressure levels it reaches, the shuttle spool 85 will proportionally divide or split the flows into cavities 89 and 90, respectively, with the proportion being preset by the comparative orifice sizes of orifices 87 and 88. In other words, if it is desirous to obtain one-third of the flow to bucket cylinder 14, and two-thirds of the flow to boom motor port 42, the orifices 87 and 88 will be accordingly sized.
As the boom 15 continues to rise, the flow is split at flow divider valve 20, with a portion of the flow passing to the cap end of bucket cylinder 14 via cavity 90, across check valve 91. The other split flow in cavity 89 flows back through boom motor port 42. The left edge of land 74 on the boom spool opens port 42 to return cavity 32, which in turn is open to reservoir 62 as long as bucket spool 46 has its open center cavities 54 and 56 open.
The flow exhausting from the rod end of bucket cylinder 14 enters flow divider valve 20 through cavity 97 and passes to reservoir 62 across unloading valve spool 92 as long as there is pressure in cavity 90. If bucket cylinder 14 attempts to overspeed and cavitate due to the weight in the bucket, the pressure in the cap end of cylinder 14 drops to zero which is felt in cavity 90, allowing unloading spool 92 to shift to the right due to spring 93 and block the flow from the rod end of bucket cylinder 14 to drain, thereby stopping movement of the cylinder until pressure again builds in the cap end.
If during the raising of the boom 15, the operator decides to override the self-leveling function, and say dump the bucket as the boom is rising; the operator would move the bucket spool to the left from its neutral position, as shown in the drawing. Land 80 on the bucket spool would block the open center flow through cavities 54 and 56, thereby building pressure in cavity 54 upstream of the bucket spool 46 since there is return flow entering motor port 42 from the flow divider valve 20. This split flow from cavity 89 which normally is passed to drain across the open center cavity 54 of the bucket is now blocked at the open center cavity 54 and is being forced into power passage 58 (air passage 99). With spool 46 shifted to the left, the right hand edge of valve spool land 80 opens power passage 58 to motor port 60, which in turn connects with the cap end of bucket cylinder 14. The rod end of bucket cylinder 14 is open to drain either through unloading valve 92 or across a parallel line 96 which connects with motor port 48 which also is open to drain due to the position of spool land 76. Since the split flow from flow divider 20 is supplied to the return side (part 42) of the boom cylinder, there is fluid pressure available upstream of bucket spool 13 (via the edge of land 74, passage 32 and passage 38) to effect an overriding function when the boom cylinder is in a raise position. In a conventional series type circuit, this would not be possible since the actuation of any upstream valve would block the downstream valve from any positive pressure so long as the upstream valve was in an operative position. While the present invention shows the split return flow to enter a motor port 42 of the boom valve, it could also enter a separate port which connected with either a return cavity 32 or open center cavity 38.
Flow divider valve 20 has a different function when the flow direction through the valve is reversed, such as when boom spool 28 is moved to the left to its lower position. Open center flow is blocked building pressure in cavity 24 while the right edge of land 72 opens power passage 40 to motor port 42 causing pressure to flow in a reverse direction into the left end of shuttle spool 85. Pressure in cavity 89 forces shuttle spool 85 to its far right position blocking any flow to cavity 90 with all of the flow passing through cavity 84 to the rod end of boom cylinder 12. Flow divider valve 20 has now become a shut-off valve to any flow in cavity 90 that might flow to the bucket cylinder 14. While there is one flow path from the opposite ends of bucket cylinder 14 through the flow divider 20 (via passage 90, cap end of cylinder 14, rod end of cylinder 14, passage 97 and drain 62), there is also a parallel flow path to both ends of the cylinder through lines 95 and 96 which allow bucket spool 46 to independently control the bucket cylinder.
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A self-leveling series type hydraulic system including boom and bucket valves which separately control boom and bucket cylinders and a flow divider valve positioned in the exhaust flow path from the rod end of the boom cylinder. The flow divider valve splits the flow sending a portion of it to the cap end of the bucket cylinder so as to maintain the bucket in a level condition during raising of the boom with the remaining flow connected to one of the boom valve motor ports whereby the bucket valve can be separately actuated concurrent with the boom valve and supplied with oil so as to override the self-leveling function if desired.
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FIELD OF APPLICATION
[0001] The present invention relates to a detecting device of unbalance conditions particularly for washing machines and similar rotary-drum household appliances activated by a synchronous electric motor.
[0002] In particular, this invention relates to a device being capable of continuously detecting the load unbalance in washing machines, washers and similar household appliances, wherein the drum is rotation-operated by a permanent-magnet synchronous electric motor.
PRIOR ART
[0003] As it is well known to the skilled in the art, washing machines for domestic use are equipped with a rotary drum, inserted in a tank and connected thereto by means of springs and shock absorbers, rotation-operated by an electric motor.
[0004] An electronic control board electrically connected to a washing machine main board allows the electric motor operation to be regulated both in the start-up step and during all the different operating steps: washing, rinsing, spin-drying, etc.
[0005] In the case of the present invention, the electric motor is of the permanent-magnet synchronous type comprising an internal stator having stator windings fixedly mounted on a central axis and an external cup-like rotor surrounding the stator. The washing machine rotary drum is kinematically connected to the synchronous motor rotor by means of suitable pulleys and a driving belt and it comprises a variable load both for the mass and for the space arrangement inside the drum.
[0006] Obviously, the variation or better the resultant of the load unbalance during some operating steps of the washing machine, particularly during the rinsing and high-motor-rotation spin-drying step, lets the tank undergo inertial acceleration forces.
[0007] These inertial forces are obviously transferred to the washing machine structure and, if uncontrolled, they can cause undesired vibrations as well as improper and bothersome displacements of the machine itself.
[0008] In general, in a washing machine, the electric motor, the corresponding electronic control board and the device for determining possible load unbalances are arranged in positions being spaced from each other.
[0009] In practise, the electric motor is positioned in a washing machine lower portion, the electronic board is arranged in a separated area near the main board and it is connected to the electric motor by means of specific wire assemblies, while a device for determining the load unbalance resultant is positioned near the rotary drum and it is connected in turn to the electronic control board by means of suitable wire assemblies.
[0010] The separation between the electronic board and the motor is mainly due to the internal-rotor motor configuration wherein the statoric part serves as a connection to the washing machine tank structure and thus it does not allow a supporting function also for the motor control electronics to be performed.
[0011] However, this separation requires a complex and expensive wire assembly to connect both the electronic board with the corresponding electric motor and the device for determining the load unbalance resultant with the electronic board controlling it.
[0012] The high wire assembly being required obviously involves higher electric motor maintenance costs in case of failure.
[0013] Some solutions are already known to determine possible unbalances of the load in the rotary drum, such as for example the teachings comprised in the U.S. Pat. No. 5,677,606, concerning a method for determining the unbalance of a load according to the current absorbed by the motor, or from the method described in the US patent application no. US2002/0035757. Nevertheless, these methods refer to universal motors and not specifically to synchronous electric motors and the indicated methods are particularly complex and not easily determinable. Further known solutions provide the positioning of an accelerometer on the tank. As it is known, the accelerometer is an analogue sensor providing an output voltage being proportional to an inertial force generally exerted on a small mass hanging from a flexible support integral with the sensor envelope.
[0014] However, these known solutions have some drawbacks, in fact they require the use of detecting devices positioned near the rotary drum and they require amplifiers and suitable circuits to process the output voltage as well as suitable wire assemblies to connect these devices to the electronic control board.
[0015] A further disadvantage of known devices is due to the fact that the measure is sometimes not completely reliable and the results being provided are not very precise also due to the noises induced on the connecting wire assembly between the accelerometer and the electronic control board.
[0016] A further disadvantage is represented by the cost of the connecting wire assemblies and of the labour required for the correct assembly thereof.
[0017] Known solutions are thus not completely satisfactory in terms of costs and/or provided performances.
[0018] According to one aspect to the present invention is therefore to provide a detecting device of unbalance conditions particularly for washing machines and similar household appliances activated by a synchronous electric motor, having such a structure and functionality as to allow the washing machine acceleration to be continuously detected with sufficient accuracy in order to prevent possible oscillations, noise and shakes of the whole washing machine structure as well as possible operation irregularities. The device should also allow an important reduction of the connecting wire assemblies to the control board, and of the same to the motor, a considerable cost saving, both of the materials and of the labour providing an extremely compact device.
SUMMARY OF THE INVENTION
[0019] An embodiment to the present invention provides an electronic control board, connected to the synchronous electric motor stator and supported thereby, incorporating an accelerometer to constantly detect the washing machine tank acceleration.
[0020] One aspect to the device according to the present invention allows the motor speed to be controlled in order to drastically reduce the vibrations and oscillations, of the drum and of the household appliance itself, due to an unbalance of the load in the drum, as well as the undesired effects of these vibrations such as: noise, shakes and operation irregularities.
[0021] Advantageously according to another aspect to the invention a piezoelectric-film accelerometer is used.
[0022] Further features and advantages of the device according to the invention will be apparent from the following description of an embodiment with reference to the attached drawings given by way of indicative and non limiting example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In the drawings
[0024] FIG. 1 schematically shows a washing machine incorporating a synchronous electric motor;
[0025] FIG. 2 is a three-quarter view of a synchronous electric motor comprising a device according to the present invention;
[0026] FIG. 3 shows a detail of the device of FIG. 2 ;
[0027] FIG. 4 is a section of the electric motor of FIG. 2 ;
DETAILED DESCRIPTION
[0028] With reference to FIG. 1 , a washing machine with a rotary drum 2 a , supported by means of springs and shock absorbers by a tank 2 is schematically represented with 1 , for which a permanent-magnet synchronous electric motor 3 is used, equipped with a device 50 , according to an embodiment of the present invention.
[0029] The electric motor is of the so-called internal-stator and external-rotor type, i.e. of the type wherein the rotor 4 is mounted outside the corresponding stator 5 .
[0030] In the case of the solution being shown, the synchronous electric motor 3 is kinematically connected in a traditional way to the rotary drum 2 a of the washing machine 1 by means of a belt pulley connection 7 which can be seen in FIG. 1 .
[0031] Moreover, the synchronous electric motor 3 is supported by the tank 2 by means of suitable locking means 70 such as for example one or more brackets. In a fully traditional way, the tank 2 is thus connected to the external structure of the washing machine 1 .
[0032] On the whole, the internal stator 5 of the synchronous electric motor 3 has a substantially cylindrical configuration and it comprises a plurality of known pole pieces 6 each of them being defined by a corresponding plurality of equal plates, packed the one onto the other, in mutual contact, as emphasised in FIG. 4 .
[0033] The stator 5 traditionally has an axial passage 15 , which is also substantially cylindrical, with a predetermined diameter, or prismatic, and intended to be engaged by an axis 10 .
[0034] The synchronous electric motor 3 comprises the device 50 electrically connected to the motor itself, which is, in the present embodiment, made integral with an heat sink element 20 associated with the device 50 which has a blade-like configuration with a wide thermal exchange surface.
[0035] Advantageously, according to the present invention, the device 50 comprises an electronic control board 18 for the synchronous motor 3 suitably supported by the stator 5 by means of an axial extension thereof. According to the embodiment shown in FIGS. 2 and 4 , the electronic board 18 is housed in a recess 21 obtained on the heat sink element 20 side turned towards the stator 5 .
[0036] Moreover, in a preferred embodiment, in order to obtain the electric connection between the electronic board 18 and the stator 5 , the synchronous electric motor 3 comprises first connecting elements 22 of the board 18 projecting towards the stator 5 and second connecting elements 24 of the stator 5 projecting towards the board 18 .
[0037] In the case of the solution being shown, the first and second connectors 22 and 24 respectively are connectors of the male/female fast-clutch type, such as for example fastom connectors.
[0038] Advantageously, the electronic board 18 of the device 50 , as highlighted in FIG. 2 , incorporates at least one accelerometer 51 connected to the tank 2 by means of a fast connector connection and intended to constantly monitor the acceleration or better the inertial acceleration forces of the tank 2 generated by a resultant of the load unbalance forces in the rotary drum 2 a . In an indirect way, this measure allows a load unbalance in the rotary drum 2 a to be determined.
[0039] The accelerometer 51 in the electronic board 18 , associated with the stator 5 , also allows the unbalance of the electronic board 18 as well as of the whole washing machine 1 to be indirectly determined, the synchronous electric motor 3 and thus the stator 5 being substantially integral with the tank 2 thanks to the locking means 70 and the tank 2 with the structure of the washing machine 1 by means of the usual connections.
[0040] In greater detail, the heat sink 20 is directly fixed on the frame 8 of the stator 5 by means of clamping screws 30 . Preferably the clamping screws 30 can be screwed from outside the electric motor 3 , in suitable internally-hollow bushes 37 , so as to favour fixing operations.
[0041] Obviously, other and different solutions can be realised to associate the electronic board 18 with the stator 5 and with the heat sink 20 .
[0042] Advantageously, in the shown embodiment, the accelerometer 51 in the electronic board 18 is of the piezoelectric-film type with detections on three axes. More particularly, as highlighted in FIG. 3 , the three-axis accelerometer 51 has three arms 53 , 54 and 55 oriented according to three space directions X, Y and Z, each arm being composed of an uniaxial accelerometer of the piezoelectric-film type.
[0043] The three arms 53 , 54 and 55 are associated with a central body 52 .
[0044] The central body 52 internally comprises at least one integrated circuit allowing the signals coming from each of the three arms 53 , 54 and 55 to be processed in order to generate an output signal being proportional to the force exerted in correspondence with the ends of the three arms.
[0045] The corresponding acceleration is mathematically obtained according to the well known laws of physics.
[0046] Preferably, the central body 52 is integrally and electrically connected to the electronic board 18 and it has the arm 53 extended according to the direction X arranged perpendicularly to the electric board 18 itself.
[0047] Obviously the accelerometer 51 can be also of the bidirectional or monodirectional type comprising two or only one piezoelectric-film accelerometer respectively, or it can be of the piezoresistive type or even of the capacitive-variation type, also called tunnel effect. The accelerometer 51 , according to the patterns being used, provides one or more output signals which, applied and suitably processed by the electronic board 18 , allow the operation of the synchronous electric motor 3 to be suitably modified, thus controlling the inertial forces of the tank 2 . For example, following the output signal, a correction signal of the speed of the synchronous electric motor 3 or an alarm or stop signal can be generated according to the requirements and functionality of the washing machine 1 itself.
[0048] The continuous monitoring of the accelerometer 51 on the tank 2 and a continuous control on the output signal of the accelerometer 51 itself allow vibrations, noise as well as the improper and bothersome displacements of the washing machine 1 to be avoided in the bud.
[0049] Obviously different solutions of the present invention can be provided, for example by using two accelerometers 51 positioned on the electronic board 18 , one for detecting the acceleration forces of the tank 2 and one for accelerating the electronic board 18 and thus the structure of the washing machine 1 .
[0050] The main advantage of the detecting device of unbalance conditions according to the invention is that it allows the inertial acceleration forces of the washing machine tank ( 2 ) to be constantly and continuously monitored directly by an accelerometer positioned on the electronic board associated with the stator of a synchronous electric motor. A further advantage is due to the reduced wire assemblies that the solution being shown involves both for the easy connection of the electronic control board to the stator and for the accelerometer being directly on the electronic board and this involves a limited-cost realisation as well as a reduced and an improved signal detection.
[0051] Moreover, due to the fact that the accelerometer allows the displacements of the electronic board to be detected and being the latter tightly integral with the stator and with the tank due to the locking means 70 , it allows the washing machine displacements to be detected providing an electric signal which can be effectively used to avoid vibrations and noise in the bud.
[0052] A further advantage is due to the fact that by using an accelerator being directly arranged on the electronic board and the latter being associated with the synchronous motor stator an extremely compact, functional device is realised at extremely reduced costs.
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A detecting device of unbalance conditions, particularly for washing machines ( 1 ) and similar household appliances comprising a rotary drum ( 2 a ) supported by a tank ( 2 ) and activated by a synchronous electric motor ( 3 ) with an internal stator ( 5 ) having corresponding windings fixedly mounted on a central axis ( 10 ). The detecting device comprises an electronic control board ( 18 ) for the synchronous motor ( 3 ) associated with the stator ( 5 ) and incorporating at least one accelerometer ( 51 ) to constantly monitor the acceleration of said tank ( 2 ) and indirectly the unbalance of said washing machine ( 1 ) and the unbalance of a load comprised in the rotary drum ( 2 a ).
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is the U.S. national stage of application No. PCT/JP2015/078889, filed on Oct. 13, 2015. Priority under 35 U.S.C. §119(a) and 35 U.S.C. §365(b) is claimed from Japanese Application No. 2014-212134, filed on Oct. 16, 2014, and Japanese Application No. 2015-106873, filed on May 26, 2015, the disclosures of which are also incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a work vehicle.
BACKGROUND ART
[0003] Conventionally known work vehicles include a tractor for farm work and a wheel loader for construction work. Some of such work vehicles use a working machine attached thereto, corresponding to the work to be performed. Some working machines can be interlocked with the work vehicles. For example, the tractor can be interlocked with a loader, a sprayer, a broadcaster, and the like (refer to Patent Literature 1).
[0004] Generally, a working machine is provided with an interlock switch with which interlocking with the tractor is turned ON and OFF, and a display lamp indicating the interlocking with the tractor. Thus, the interlocking state with respect to the tractor is operated and displayed.
CITATION LIST
Patent Literature
[0005] PTL 1: Japanese Unexamined Patent Application Publication No. 2004-329067
SUMMARY OF INVENTION
Technical Problem
[0006] The tractor has no unit for operating and displaying the interlocking state with respect to the working machine. Thus, the operator on the tractor needs to get off the tractor and move to the working machine to check and operate the interlocking state. In particular, when working machines, such as a loader and a broadcaster, are attached to front and rear sides of the working machine at the same time, the operator needs to go through a cumbersome procedure of moving to and checking both working machines.
[0007] An object of the present invention is to provide a work vehicle that enables an operator to check a currently interlocked working machine and set a working machine to be interlocked on the work vehicle side.
Solution to Problem
[0008] The present invention provides a work vehicle to which a working machine is attachable, the work vehicle including: a display unit configured to display, in a selectable manner, a working machine that is attached and is able to be interlocked, and to display, in an identifiable manner, a currently interlocked working machine; an operation unit with which an operation of selecting and determining a working machine displayed, on the display unit, is performed; and a control unit configured to perform control, when an operation of determining a desired working machine is performed with the operation unit, interlocking of the currently interlocked working machine is released and the desired working machine determined by the operation is interlocked.
[0009] In the above-described work vehicle, the display unit may be configured to display a working machine that is not attached and is able to be interlocked, in an identifiable and non-selectable manner.
[0010] In the above-described work vehicle, the control unit may be configured to perform control in such a manner that the working machine that is attached and is able to be interlocked is detected at a predetermined interval.
[0011] In the above-described work vehicle, the operation unit may include a plurality of buttons and an encoder dial integrally provided to the display unit.
[0012] The above-described work vehicle may further include a transmission lever connected to the control unit; and a switch provided to the transmission lever. When a sprayer is interlocked as the working machine, the switch may be assigned with any one of a spraying start/end function for the sprayer, a spraying amount adjustment function for the sprayer, an extending/contracting adjustment function for a boom of the sprayer, an inclination adjustment function for the boom, an opening/closing adjustment function for the boom, and a lifting/lowering adjustment function for the boom.
[0013] The above-described work vehicle may further include a transmission lever connected to the control unit; and a switch provided to the transmission lever. When a broadcaster is interlocked as the working machine, the switch may be assigned with a spraying start/end function for the broadcaster or a spraying amount adjustment function for the broadcaster.
Advantageous Effects of Invention
[0014] With the work vehicle according to the present invention, a unit for operating and displaying an interlocking state with the working machine is provided on a work vehicle side. Thus, the operator can set and check the interlocking state of the working machine on the side of the work vehicle. Thus, the operator on the work vehicle can check the currently interlocked working machine and set the working machine to be interlocked, while being on the work vehicle, that is, without getting off the work vehicle and moving to the working machine, and thus can enjoy a higher work efficiency.
[0015] A unit for operating and displaying the interlocking state with respect to the work vehicle can be omitted from the working machine, and thus a cost reduction can be achieved. When the unit for operating and displaying the interlocking state with respect to the work vehicle is provided to the working machine, the operator can set and check the interlocking state on the work vehicle and on the working machine and thus can enjoy a higher operability.
[0016] With the work vehicle according to the present invention, a working machine that can be interlocked but is not attached may be displayed in the identifiable manner. Thus, the operator can enjoy higher convenience with the working machine that can be interlocked but is not attached being immediately identifiable. The working machine that can be interlocked but is not attached cannot be selected, and thus is prevented from being accidentally selected by the operator.
[0017] With the work vehicle according to the present invention, the working machine that is attached and can be interlocked is detected at a predetermined interval. Thus, a latest state indicating a working machine that can be interlocked can be displayed.
[0018] With the work vehicle according to the present invention, the plurality of buttons and the encoder dial integrally formed with the display unit may be used as the operation unit. Thus, an operation can be intuitively and quickly performed.
[0019] With the work vehicle according to the present invention, the switch provided to the transmission lever may be assigned with the desired function for operating the interlocked working machine. Thus, the operator can easily operate the assigned functions at hand without releasing his or her hand from the transmission lever and thus can enjoy a less cumbersome operation. All things considered, higher operability and work efficiency can be achieved, and a load on the operator can be reduced.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1 is an external perspective view of a tractor.
[0021] FIG. 2 is a diagram viewed in the direction of an arrow X in FIG. 1 .
[0022] FIG. 3 is a diagram viewed in the direction of an arrow Y in FIG. 1 .
[0023] FIG. 4 is a diagram viewed in the direction of an arrow Z in FIG. 1 .
[0024] FIG. 5 is a diagram illustrating a power transmission system of the tractor.
[0025] FIG. 6 is a diagram illustrating a link mechanism of the tractor.
[0026] FIG. 7 is a diagram illustrating an operator's seat of the tractor and its periphery.
[0027] FIG. 8 is a diagram illustrating a field of view of an operator.
[0028] FIG. 9 is a diagram illustrating an information network of the tractor.
[0029] FIG. 10 is a diagram illustrating a display.
[0030] FIG. 11 is a diagram illustrating a portion of a control system of the tractor related to the display.
[0031] FIG. 12 is a diagram illustrating a screen displayed on the display.
[0032] FIG. 13 is a diagram illustrating a screen displayed on the display.
[0033] FIG. 14 is a diagram illustrating a screen displayed on the display.
[0034] FIG. 15 is a diagram illustrating a screen displayed on the display.
[0035] FIG. 16 is a diagram illustrating a screen displayed on the display.
[0036] FIG. 17 is a diagram illustrating an operation control tool provided to an armrest.
[0037] FIG. 18 is a diagram illustrating an example of a CAN.
[0038] FIG. 19 is a diagram schematically illustrating the CAN connection between the tractor and a working machine.
[0039] FIG. 20 is a block diagram illustrating a configuration of the CAN in the tractor.
[0040] FIG. 21 is a diagram illustrating a screen displayed on the display.
[0041] FIG. 22 is a diagram illustrating an instrument panel.
[0042] FIG. 23 is a diagram illustrating a screen displayed on the display.
[0043] FIGS. 24A and 24B are schematic views illustrating control in a case where a spraying amount of a sprayer is increased, and includes 24 A illustrating constant vehicle speed control, and 24 B illustrating constant spraying pressure control.
[0044] FIG. 25 is a diagram illustrating a screen displayed on the display.
[0045] FIG. 26 is a diagram illustrating a screen displayed on the display.
DESCRIPTION OF EMBODIMENTS
[0046] The technical concept of the present invention is applicable to any work vehicle. The following gives a description using a tractor, which is a typical work vehicle, as an example.
[0047] First, a tractor 1 is briefly described.
[0048] FIG. 1 illustrates the tractor 1 . FIG. 2 is a diagram viewed in the direction of an arrow X in FIG. 1 , FIG. 3 is a diagram viewed in the direction of an arrow Y in FIG. 1 , and FIG. 4 is a diagram viewed in the direction of an arrow Z in FIG. 1 . In these figures, the front and rear direction, the right and left direction, and the upper and lower direction of the tractor 1 are illustrated.
[0049] The tractor 1 mainly includes a frame 11 , an engine 12 , a transmission 13 , a front axle 14 , and a rear axle 15 . The tractor 1 further includes a cabin 16 . The cabin 16 has an inner side serving as an operation control room in which an operator's seat 161 , an accelerator pedal 162 , a shift lever 163 , and the like are arranged (see FIG. 7 ).
[0050] The frame 11 serves as a front frame of the tractor 1 . The frame 11 , the transmission 13 , and the rear axle 15 form a chassis of the tractor 1 . The frame 11 is provided with a pair of working machine supporters 32 that supports a working machine (for example, a loader) attached to a front portion of the tractor 1 .
[0051] The working machine supporters 32 are formed of plate shaped members protruding outward and extending upward from left and right side surfaces of the frame 11 . The working machine supporters 32 have upper portions provided with a hole and a notch with which the working machine is attached.
[0052] The engine 12 is supported by the frame 11 . The engine 12 burns fuel, and converts thermal energy thus obtained into kinetic energy. Thus, the engine 12 burns fuel to generate rotary driving force. An engine controller (not illustrated) is connected to the engine 12 . When an operator operates the accelerator pedal 162 (see FIG. 7 ), the engine controller changes an operational state of the engine 12 in accordance with the operation. The engine 12 is provided with an exhaust gas purifier 12 E. The exhaust gas purifier 12 E oxidizes fine particles, carbon monoxide, hydrocarbon, and the like in exhaust gas.
[0053] The transmission 13 transmits the rotary driving force from the engine 12 to the front axle 14 and the rear axle 15 . The transmission 13 receives the rotary driving force from the engine 12 via a connection mechanism. The transmission 13 is provided with a continuously variable transmission (I-HMT) 131 (see FIG. 5 ). When the operator operates the shift lever 163 (see FIG. 7 ), the continuously variable transmission 131 changes an operating state of the transmission 13 in accordance with the operation.
[0054] The front axle 14 transmits the rotary driving force from the engine 12 to front wheels 141 . The front axle 14 receives the rotary driving force from the engine 12 via the transmission 13 . A steering device (not illustrated) is arranged adjacent to the front axle 14 . When the operator operates a steering wheel 164 (see FIG. 7 ), the steering device changes a steering angle of the front wheels 141 in accordance with the operation.
[0055] The front axle 14 is provided with a hydraulic pump 142 (see FIG. 5 ). When the operator operates a joystick 176 (see FIG. 7 ), the hydraulic pump 142 transmits hydraulic pressure to the working machine attached to the front portion of the tractor 1 in accordance with the operation.
[0056] The rear axle 15 transmits the rotary driving force from the engine 12 to rear wheels 151 . The rear axle 15 receives the rotary driving force from the engine 12 via the transmission 13 . The rear axle 15 is provided with a PTO output device 152 (see FIG. 5 ). When the operator operates a PTO switch 165 (see FIG. 7 ), the PTO output device 152 transmits the rotary driving force to a working machine being pulled, in accordance with the operation. The rear axle 15 is also provided with a link mechanism 35 (see FIG. 6 ).
[0057] Next, a power transmission system of the tractor 1 is described.
[0058] FIG. 5 illustrates the power transmission system of the tractor 1 . It is to be noted that each figure simply illustrates only portions required for the description of the present invention.
[0059] As described above, the transmission 13 transmits rotary driving force from the engine 12 to the front axle 14 and the rear axle 15 . Thus, the transmission 13 has a mechanism for transmitting the rotary driving force to the front axle 14 and a mechanism for transmitting the rotary driving force to the rear axle 15 . In this description, the mechanism for transmitting the rotary driving force to the front axle 14 is referred to as a front drive mechanism 33 .
[0060] The front drive mechanism 33 includes a drive shaft 331 , a constant-speed drive gear 332 , and an acceleration drive gear 333 . The front drive mechanism 33 further includes a constant speed clutch 334 , a constant speed driven gear 335 , an acceleration clutch 336 , and an acceleration driven gear 337 . The front drive mechanism 33 further includes an output shaft 338 .
[0061] The drive shaft 331 is rotatably supported via a bearing. The constant-speed drive gear 332 is attached to the drive shaft 331 . The acceleration drive gear 333 is also attached to the drive shaft 331 . Thus, the constant-speed drive gear 332 and the acceleration drive gear 333 rotate while being integrated with the drive shaft 331 .
[0062] The constant speed clutch 334 is rotatably supported via a bearing. The constant speed driven gear 335 is attached to an inner hub of the constant speed clutch 334 while meshing with the constant-speed drive gear 332 . Thus, the constant speed driven gear 335 rotates while being integrated with the inner hub of the constant speed clutch 334 . The acceleration clutch 336 is also rotatably supported via a bearing. The acceleration driven gear 337 is attached to an inner hub of the acceleration clutch 336 while meshing with the acceleration drive gear 333 . Thus, the acceleration driven gear 337 rotates while being integrated with the inner hub of the acceleration clutch 336 .
[0063] The output shaft 338 is rotatably supported via a bearing. The constant speed clutch 334 has an outer cylinder attached to the output shaft 338 . Thus, the outer cylinder of the constant speed clutch 334 rotates while being integrated with the output shaft 338 . The acceleration clutch 336 also has an outer cylinder attached to the output shaft 338 . Thus, the outer cylinder of the acceleration clutch 336 rotates while being integrated with the output shaft 338 .
[0064] With this structure, when the inner hub of the constant speed clutch 334 is coupled to the outer cylinder (when the constant speed clutch 334 operates), the rotation of the drive shaft 331 is transmitted to the output shaft 338 . Then, a propeller shaft 43 rotates, and thus the front wheels 141 rotate via a differential mechanism 34 . When the four-wheel drive is achieved with the constant speed clutch 334 operated, the rear wheels 151 and the front wheels 141 rotate at the same circumferential speed (referred to as constant speed four-wheel drive).
[0065] Similarly, also when the inner hub of the acceleration clutch 336 is coupled to the outer cylinder (when the acceleration clutch 336 operates), the rotation of the drive shaft 331 is transmitted to the output shaft 338 . Then, the propeller shaft 43 rotates, and thus the front wheels 141 rotate via the differential mechanism 34 . When the four-wheel drive is achieved with the acceleration clutch 336 operated, the front wheels 141 rotate with a higher circumferential speed than that of the rear wheels 151 (referred to as acceleration four-wheel drive).
[0066] Next, the link mechanism 35 of the tractor 1 is described.
[0067] FIG. 6 illustrates the link mechanism 35 of the tractor 1 . The link mechanism 35 includes: a top bracket 351 attached to a rear portion of the rear axle 15 ; and a top link 352 attached to a hinge portion of the top bracket 351 . The link mechanism 35 further includes: a lower bracket 353 attached to a lower portion of the rear axle 15 ; and a lower link 354 attached to a hinge portion of the lower bracket 353 .
[0068] The link mechanism 35 further includes: lift arms 355 attached to side portions of the rear axle 15 ; a lifting and lowering actuator 356 attached to a center portion of the lift arm 355 ; a lift link 357 attached to the left lift arm 355 and the lower link 354 ; and an inclination actuator 358 attached to the right lift arm 355 and the lower link 354 .
[0069] With the link mechanism 35 having this configuration, the working machine attached to the tractor 1 can be lifted, lowered, and inclined with three links including the top link 352 and the two lower links 354 .
[0070] Next, the operation control room of the tractor 1 is described.
[0071] FIG. 7 illustrates the operator's seat 161 and its periphery. FIG. 8 illustrates a field of view of the operator. FIG. 17 illustrates an operation control tool provided to an armrest 161 r.
[0072] As described above, the cabin 16 has the inner side serving as the operation control room in which the operator's seat 161 , the accelerator pedal 162 , the shift lever 163 , and the like are arranged. A brake pedal 166 , a clutch pedal 167 , a reverser lever 168 , a speed dial 169 , an instrument panel 170 , a control panel 171 , a transmission lever 172 , a working machine lifting/lowering switch 173 , working machine lifting/lowering fine-control switches 174 , and the like are arranged in the periphery of the operator's seat 161 . The operator can operate the accelerator pedal 162 , the shift lever 163 , and the like while being seated on the operator's seat 161 to operate the tractor 1 .
[0073] The control panel 171 is disposed in the armrest 161 r that can be opened and closed, and is connected to the control device 3 . The control panel 171 is an operation tool for performing various settings related to the working machine. The operator can perform various settings suitable for the connected working machine, by operating the control panel 171 .
[0074] The transmission lever 172 is disposed on an upper surface of the front portion of the armrest 161 r , and is connected to the control device 3 . When the operator inclines the transmission lever 172 having a pivotable structure as appropriate, a shifting operation is performed. Thus, the operator can freely adjust the traveling speed.
[0075] The working machine lifting/lowering switch 173 is provided on the front surface of the transmission lever 172 (see FIG. 17 ). The working machine lifting/lowering switch 173 is a slidable switch for lifting and lowering the working machine attached to the rear portion of the tractor 1 . The working machine lifting/lowering switch 173 is connected to the control device 3 . When the working machine lifting/lowering switch 173 is slid upward, the working machine is lifted. When the working machine lifting/lowering switch 173 is slid downward, the working machine is lowered. Thus, the operator can freely lift and lower the working machine attached to the rear portion of the tractor 1 .
[0076] A pair of upper and lower working machine lifting/lowering fine-control switches 174 are provided on a left surface of the transmission lever 172 (see FIG. 17 ). The working machine lifting/lowering switches 174 are push switches for lifting and lowering the working machine attached to a rear portion of the tractor 1 , within a small range. The working machine lifting/lowering fine-control switches 174 are connected to the control device 3 . The working machine is lifted within a small range when the upper switch is pressed, and is lowered in a small range when the lower switch is pressed. Thus, the operator can freely lift and lower the working machine attached to the rear portion of the tractor 1 . Thus, the operator can roughly adjust the height of the working machine with the working machine lifting/lowering switch 173 and then finely adjust the height with the working machine lifting/lowering fine-control switches 174 .
[0077] The joystick 176 is disposed on the right side of the operator's seat 161 (see FIG. 7 ). The operator can operate the working machine (for example, a loader) attached to the front portion of the tractor 1 , by operating the joystick 176 while being seated on the operator's seat 161 .
[0078] The tractor 1 includes a display 2 disposed close to the operator's seat 161 . The display 2 is disposed on a front right side of the operator's seat 161 so as to be operable with the right hand of the operator. An information network of the tractor 1 is briefly described below. Furthermore, the display 2 and a control system including the display 2 are described in detail below.
[0079] FIG. 9 illustrates the information network of the tractor 1 . FIG. 10 illustrates the display 2 . FIG. 11 illustrates a portion of the control system of the tractor 1 related to the display 2 . The control device 3 includes a storage unit 31 , and can store information required for the control. The storage unit 31 may be provided outside the control device 3 .
[0080] The tractor 1 has the information network installed over various locations to achieve the maximum performance. Specifically, the transmission 13 , the instrument panel 170 , the control panel 171 , and the display 2 form a controller area network (CAN) together with the engine 12 so that the components can share information with each other.
[0081] As illustrated in FIG. 18 , the CAN may include the working machine. Examples of information communicated between the tractor 1 and working machines A to C include: rotation speed and water temperature of the engine 12 ; vehicle speed; a transmission stage; a state of the transmission 13 ; and a state of the link mechanism 35 (depth, inclination, or the like). The engine 12 , the transmission 13 , and the link mechanism 35 are collectively controlled by the control device 3 , and information on these and warning are displayed on the instrument panel 170 or the display 2 . Sophisticated control can be achieved with these various pieces of information transmitted between the tractor 1 and the working machines A to C. Thus, higher operability and work efficiency can be achieved, and a load on the operator can be reduced.
[0082] FIG. 19 is a diagram schematically illustrating the CAN connection between the tractor 1 and the working machine. As illustrated in FIG. 19 , the control device 3 serving as the tractor side controller is provided to the tractor 1 , and a working machine side controller 5 for controlling the working machine is provided to the working machine. The tractor side controller and the working machine side controller 5 are connected to each other via a connector 6 . The connector 6 may be a connector of the AG-PORT standard or the ISOBUS standard. Thus, bidirectional communications may be performed between the tractor side controller and the working machine side controller 5 . Thus, for example, the lever and the like on the side of the tractor 1 can be assigned the operation of the working machine, and thus more consistent operability can be achieved. Furthermore, the cabin 16 can incorporate less wiring.
[0083] FIG. 20 is a block diagram illustrating a configuration of the CAN in the tractor 1 . An example where a loader, a sprayer, and a broadcaster serving as working machines can be connected to the CAN of the tractor 1 is described with reference to FIG. 20 . The display 2 , the connector 6 , the engine 12 , the transmission 13 , the instrument panel 170 , the control panel 171 , the transmission lever 172 , the working machine lifting/lowering switch 173 , the working machine lifting/lowering fine-control switches 174 , a loader operation panel 175 , a CAN interface 177 , and a broadcaster controller 181 are connected to the control device 3 serving as the tractor side controller via the CAN. The joystick 176 is connected to the loader operation panel 175 . A sprayer operation panel 178 , a spraying controller 179 , and a boom operation controller 180 are connected to the CAN interface 177 .
[0084] The loader operation panel 175 is a dedicated operation tool for setting up the loader. The operator can perform various setting related to the loader by operating the loader operation panel 175 . Thus, the control device 3 can acquire the information related to the content set with the loader operation panel 175 . The operator can operate the loader in accordance with various settings, by operating the joystick 176 .
[0085] The CAN interface 177 is an interface for connecting the sprayer operation panel 178 , the spraying controller 179 , and the boom operation controller 180 to the control device 3 via the CAN.
[0086] The sprayer operation panel 178 is a dedicated operation tool for setting up the sprayer. The operator can perform various settings (such as a setting on the amount of pesticide sprayed per unit area) related to the sprayer by operating the sprayer operation panel 178 . Thus, the control device 3 can acquire information related to the content set with the sprayer operation panel 178 .
[0087] The spraying controller 179 is used for performing opening/closing operation for spray valves through which pesticides are supplied to spray nozzles. The control device 3 acquires the information related to the state of the spray valves set with the spraying controller 179 , and controls the spray valves. Thus, the operator can adjust the spraying start/end timing and the spraying amount of the pesticides by operating the spraying controller 179 .
[0088] The boom operation controller 180 is operated for adjusting the extending/contracting, inclination, opening/closing, and lifting/lowering of a boom. The control device 3 acquires information on the state of the boom set with the boom operation controller 180 , and controls the boom. Thus, the operator can adjust the extending/contracting, inclination, opening/closing, and lifting/lowering of the boom by operating the boom operation controller 180 .
[0089] The broadcaster controller 181 is operated for adjusting the spraying start/end timing and the spraying amount of the broadcaster. The control device 3 acquires information related to the state of the broadcaster set by the broadcaster controller 181 , and controls the broadcaster. Thus, the operator can adjust the spraying start/end timing and the spraying amount of the broadcaster by operating the broadcaster controller 181 .
[0090] In the tractor 1 , the display 2 is disposed on a side console (see FIGS. 7 and 8 ). The display 2 includes a liquid crystal panel (display unit) 21 , an encoder dial (operation unit) 22 , an enter button (operation unit) 23 , and five command buttons (operation unit) 24 to 28 integrally provided (see FIG. 10 ).
[0091] The liquid crystal panel 21 is provided at the center of the front surface of the display 2 . The liquid crystal panel 21 can display a predetermined screen based on an instruction from the control device (control unit) 3 . For example, the liquid crystal panel 21 can display an opening screen S 1 (see FIG. 12 ) based on an instruction from the control device 3 . The liquid crystal panel 21 can display other screens (see FIG. 13 to FIG. 16 ) based on instructions from the control device 3 . The display unit is not limited to the liquid crystal panel 21 , and may be a thin display panel such as an electroluminescence (EL) panel using organic EL or inorganic EL.
[0092] The encoder dial 22 is provided on an upper right side of the display 2 . The encoder dial 22 incorporates a rotary encoder, and can transmit an intension of the operator (selection operation), to scroll a tab or shift a highlighted display, to the control device 3 for selecting an element (item) displayed on the liquid crystal panel 21 . For example, the encoder dial 22 can transmit an intension of the operator for scrolling a tab for selecting among displayed numbers and alphabets, to the control device 3 (see FIG. 13 ). The encoder dial 22 can transmit an intension of the operator to shift a highlighted display, for selecting a displayed icon, to the control device 3 (see FIG. 14 to FIG. 16 ).
[0093] The enter button 23 is integrally formed with the encoder dial 22 . The enter button 23 is an operation button corresponding to the upper and lower movement of the encoder dial 22 , and is operated by pressing the upper surface of the encoder dial 22 . The enter button 23 may be a push button provided on an upper end surface of the encoder dial 22 .
[0094] The enter button 23 can transmit an intension of the operator (determination operation) to determine one of the elements (items) displayed on the liquid crystal panel 21 to the control device 3 . For example, the enter button 23 can transmit an intension of the operator to determine one of the displayed numbers or alphabets, to the control device 3 (see FIG. 13 ). The enter button 23 can transmit an intension of the operator to determine one of the displayed icons, to the control device 3 (see FIG. 14 to FIG. 16 ).
[0095] The five command buttons 24 to 28 are operation buttons for performing an operation for determining an icon displayed in the upper end of the screen. The command buttons 24 to 28 are arranged side by side in the upper portion of the front surface of the display 2 . The command buttons 24 to 28 each correspond to an icon immediately therebelow on the liquid crystal panel 21 . The command buttons 24 to 28 can each transmit an intension of the operator to determine a corresponding one of the icons to the control device 3 . When any one of the command buttons 24 to 28 is pressed, the control device 3 executes a command related to the corresponding icon. The icon and command assigned to each of the command buttons 24 to 28 differ among the screens. Thus, required icons and commands are assigned to each screen.
[0096] The commands include: a command (corresponding icon is “HOME”) for instructing switching to a first home screen S 3 , a command (corresponding icon is “free 1” or “free 2”) for instructing switching to a shortcut screen (a screen freely set by the operator), a command (corresponding icon is “determine”), with a similar function as the enter button 23 , for instructing determination of an element, a command (corresponding icon is “return”) for instructing switching to a previous screen, and a command (corresponding icon is an arrow indicating a certain direction) for instructing a direction in which a tab is scrolled and a direction in which the highlighted display is shifted.
[0097] The liquid crystal panel 21 may be provided with a touch panel as the operation unit. In this configuration, the encoder dial 22 , the enter button 23 , and the command buttons 24 to 28 can be omitted as appropriate.
[0098] Some working machines can be interlocked with the tractor 1 . When the working machine that can be interlocked is attached to the tractor 1 , the tractor 1 and the working machine can operate in an interlocking manner. The interlocking manner means that the tractor 1 operates in an optimum manner in accordance with an operation of the working machine. The interlocking manner may also mean that the working machine operates in an optimum manner in accordance with an operation of the tractor 1 . The working machine that can be interlocked with the tractor 1 includes a loader attached to the front portion, as well as a sprayer and a broadcaster attached to the rear potion, and the like.
[0099] For example, when the loader is attached to the tractor 1 in the interlocking manner, the tractor 1 is automatically controlled under a setting optimum for the loader. As a specific example, control may be performed in such a manner that the acceleration four-wheel drive is automatically switched to the constant speed four-wheel drive for safety purposes. In a case where the loader is expected to be lifted, such as a case where the loader has been detected to be knocked down, control is performed in such a manner that the engine rotation speed increases, whereby the loader can be lifted at a higher speed.
[0100] In this context, the storage unit 31 stores a list of working machines that can be interlocked. The control device 3 reads the list of working machines that can be interlocked from the storage unit 31 , generates an interlocking working machine screen S 5 (see FIG. 16 ), and performs control in such a manner that the liquid crystal panel 21 displays the screen. Specifically, the interlocking working machine is added as one menu to the screen (see, for example, a second home screen S 4 ), on which a plurality of menus are displayed in a selectable manner. When an operation of selecting and determining the interlocking working machine is performed, the interlocking working machine screen S 5 can be displayed. The interlocking working machine screen S 5 displays the attached interlocking working machines in a selectable manner, and the interlocking working machines in an identifiable manner.
[0101] The selectable manner means that the display can be in any format as long as the operator can select the desired working machine. For example, the desired working machine may be selectable through shifting the highlighted display by operating the operation unit (encoder dial 22 , enter button 23 , command buttons 24 to 28 ). The identifiable manner means that the display can be in any format as long as the operator can identify the currently interlocked working machine. For example, the identifiable manner can be achieved with a mark (such as ON display), indicating that the machine is currently interlocked, displayed on the icon of the working machine that is currently interlocked in an overlapping manner, and with a mark (such as OFF display), indicating that the machine is not currently interlocked, displayed on the icon of the working machine that is currently not interlocked in an overlapping manner.
[0102] The working machine that can be interlocked but is not attached is displayed in an identifiable and non-selectable manner. For example, the icon may be grayed out so as to be identifiable as a working machine that is not attached, and controlled in such a manner as not to be selectable by operating the operation unit. Thus, the operator can enjoy higher convenience with the working machine that can be interlocked but is not attached being immediately identifiable. The working machine that is not attached cannot be selected, and thus is prevented from being accidentally selected by the operator.
[0103] The control device 3 receives selection using the operation unit (encoder dial 22 , enter button 23 , command buttons 24 to 28 ) and the determination operation on the interlocking working machine screen S 5 , and performs control such that the working machine determined through the operation is stored in the storage unit 31 .
[0104] When a desired working machine is determined through an operation on the interlocking working machine screen S 5 , the control device 3 performs control in such a manner that the working machine determined by the operation is interlocked with the interlocking of the interlocked working machine released. Thus, even when the working machines are attached to the front and rear of the tractor 1 , only one working machine is interlocked at a time, whereby the control on the tractor 1 is prevented from being hindered.
[0105] The control device 3 performs control in such a manner that the working machine that is attached and can be interlocked is detected at a predetermined interval (for example, once in every 10 minutes, or when the operation of determining the interlocking working machine is performed on the second home screen S 4 ). Whether a working machine can be interlocked can be determined in accordance with communications with the working machine. Thus, the interlocking working machine screen S 5 can always display the latest state.
[0106] With the display 2 on which the interlocking state of the working machine with respect to the working machine is operated and displayed thus provided to the tractor 1 , the operator can set and check the interlocking state of the working machine on the side of the tractor 1 . Thus, the operator on the tractor 1 can check the currently interlocked working machine and set the working machine to be interlocked, while being on the tractor 1 , that is, without getting off the tractor 1 and moving to the working machine, and thus can enjoy a higher work efficiency.
[0107] Furthermore, the unit for operating and displaying the interlocking state with respect to the tractor 1 can be omitted from the working machine, and thus a cost reduction can be achieved. When the unit for operating and displaying the interlocking state with respect to the tractor 1 is provided to the working machine, the operator can set and check the interlocking state on the tractor 1 and on the working machine and thus can enjoy a higher operability.
[0108] A screen displayed on the display 2 , related to the interlocking between the tractor 1 and the working machine, and how the display 2 is operated are described below.
[0109] FIG. 12 to FIG. 16 illustrate a screen displayed on the display 2 . It is to be noted that each figure simply illustrates only portions required for the description of the present embodiment.
[0110] First of all, an opening screen S 1 is displayed on the display 2 (see FIG. 12 ). In the opening screen S 1 , a symbol mark Sm is displayed at a portion around the center. The symbol mark Sm is a design representing a supplier/manufacturer. The symbol mark Sm appears on a black background image, and gives a strong impression to the operator.
[0111] Next, the display 2 displays an unlock screen S 2 (see FIG. 13 ). The unlock screen S 2 display four scroll boxes Sb 1 to Sb 4 for inputting a single row of PIN code. A selected one of the scroll boxes Sb 1 to Sb 4 is displayed in a highlighted manner (see a section H in the figure). In the scroll boxes Sb 1 to Sb 4 , any one of the numbers 0 to 9 and alphabets A to F can be selected through vertical scrolling.
[0112] The unlock screen S 2 displays icons 251 , 261 , 271 , 281 corresponding to the command buttons 25 to 28 at the upper end. The unlock screen S 2 displays a dialog box Db 1 in which an operator name is displayed, and a dialog box Db 2 in which a working machine name is displayed. The operator can check whether the operator name and the working machine name are correctly set with these dialog boxes Db 1 and Db 2 .
[0113] The operator can select a number or an alphabet by rotating the encoder dial 22 through scrolling, and determine the number or the alphabet by pressing the enter button 23 . In the unlock screen S 2 , the command button 25 or 26 can be pressed to select between the numbers or alphabets through scrolling, and determine the number or alphabet by pressing the command button 27 . The determination may be cancelled by pressing the command button 28 . When an incorrect PIN code is input, a message indicating that the number is incorrect is displayed.
[0114] Next, the display 2 displays the first home screen S 3 (see FIG. 14 ). The first home screen S 3 displays icons Ia 1 to Ia 10 for selecting a menu or a page. Selected one of the icons Ia 1 to Ia 10 is displayed in a highlighted manner (see a section H in the figure). The highlighted display is shifted by rotation of the encoder dial 22 . Icons that cannot be selected are grayed out (see a section G in the figure). The first home screen S 3 displays icons 242 , 252 , 262 , 272 , and 282 , corresponding to the command buttons 24 to 28 , at the upper end.
[0115] How the icon 242 corresponding to “free 1” and the icon 252 corresponding to “free 2” are registered is briefly described with registration for “free 1” as an example. First of all, the command button 24 associated with the icon 242 corresponding to “free 1” is long pressed (for example, for 3 minutes) to cause transition to the registration screen (not illustrated). Then, the encoder dial 22 is operated with the registered screen displayed, to select a desired icon (for example, the icon “OFF”) and the enter button 23 is pressed. Thus, this icon is registered to the icon 242 corresponding to “free 1”, and the icon is displayed instead of “free 1”.
[0116] While the first home screen S 3 is displayed, the operator can select the desired one of icons Ta 1 to Ia 10 by rotating the encoder dial 22 , and can determine the icon by pressing the enter button 23 or the command button 27 . Here, the icon Ia 10 with a description “next page” is selected and determined.
[0117] Next, the display 2 displays the second home screen S 4 (see FIG. 15 ). The second home screen S 4 displays icons Ib 1 to Ib 10 . The selected one of the icons Ib 1 to Ib 10 is displayed in a highlighted manner (see the section H illustrated in the figure). The highlighted display is shifted by rotation of the encoder dial 22 . The second home screen S 4 displays icons 243 , 253 , 263 , 273 , and 283 , corresponding to the command buttons 24 to 28 , at the upper end.
[0118] In the second home screen S 4 , the operator can select the desired one of the icons Ib 1 to Ib 10 by rotating the encoder dial 22 , and determine the icon by pressing the enter button 23 or the command button 27 . Here, the icon Ib 2 , with a description “interlocking working machine”, is selected and determined.
[0119] Next, the interlocking working machine screen S 5 is displayed on the display 2 (see FIG. 16 ). The interlocking working machine screen S 5 displays three icons Ic 1 to Ic 3 with the working machine name and ON or OFF. The interlocking working machine screen S 5 displays icons 244 , 254 , 264 , 274 , and 284 , corresponding to the command buttons 24 to 28 , at the upper end.
[0120] The icons Ic 1 to Ic 3 are a list of working machines that can be interlocked. The icons Ic 1 and Ic 3 indicate the working machines that can be interlocked and are attached, and are displayed in a selectable manner. The icon Ic 2 indicates a working machine that can be interlocked but is not attached, and is displayed in a non-selectable manner. The icon Ic 2 is grayed out meaning that the icon cannot be selected. The icon Ic 2 is not selected through the rotation of the encoder dial 22 .
[0121] Thus, while the interlocking working machine screen S 5 is displayed, the operator selects the desired icon Ic 1 or Ic 3 by rotating the encoder dial 22 , and can switch between ON and OFF by pressing the enter button 23 . ON indicates that the machine is interlocked and OFF indicates that the machine is not interlocked.
[0122] FIG. 16 illustrates a state where the icon Ic 2 cannot be selected, and the determination operation can be performed for the icon Ic 1 or Ic 3 . Specifically, when one of the icons Ic 1 and Ic 3 , corresponding to the interlocked working machines, is switched from ON to OFF, the working machine is no longer interlocked. On the other hand, the working machine corresponding to the other one of the icons Ic 1 and Ic 3 determined by the operation, switched from OFF to ON, is interlocked. Thus, only one working machine is interlocked at a time.
[0123] FIG. 21 illustrates another example of the interlocking working machine screen. The icons Id 1 to Id 3 are a list of working machines that can be interlocked. This interlocking working machine screen S 51 uses a highlighted display (icon Id 1 ) for displaying the working machine that can be interlocked and is attached in a selectable manner. In the interlocking working machine screen S 51 , a green point image Id 4 is overlapped on the icon corresponding to the currently interlocked working machine, so that the currently interlocked working machine can be identified. On the interlocking working machine screen S 51 , the working machine that can be interlocked but is not attached has a corresponding icon (icon Id 2 ) with a gray background indicating that the working machine cannot be selected in an identifiable manner.
[0124] The instrument panel 170 may be provided with an interlocking lamp 170 a indicating the interlocked state, as illustrated in FIG. 22 . The interlocking lamp 170 a is turned ON when the tractor 1 and the working machine are interlocked, and is turned OFF when they are not interlocked. Thus, the operator can easily recognize whether the working machine is interlocked, simply by looking at the instrument panel 170 .
[0125] Next, another featured configuration related to the interlocking between the tractor 1 and the working machine is described. In the description below, a case where the interlocked working machine is a sprayer and a case where the interlocked working machine is a broadcaster are separately described.
[0126] When the interlocked working machine is a sprayer, the working machine lifting/lowering switch 173 and the working machine lifting/lowering fine-control switches 174 can each be assigned with any one of a sprayer spraying start/stop function, a sprayer spraying amount adjustment function, a sprayer boom extending/contracting function, a boom inclination adjustment function, a boom opening/closing adjustment function, and a boom lifting/lowering adjustment function. The assignment is invalid when the working machine is not interlocked.
[0127] A function assigned to each switch can be set by the operator in advance by using the display 2 , for example. When the tractor setting (icon Ia 3 ) is selected and determined on the first home screen S 3 , various tractor setting items are displayed, and sprayer switch assignment setting is called therefrom. Thus, a switch assignment screen S 6 as illustrated in FIG. 23 is displayed.
[0128] On the switch assignment screen S 6 , two icons Ie 1 and Ie 2 on which names of switches that can be assigned are displayed, and icons Ie 3 and Ie 4 displayed on the right of the icons Ie 1 and Ie 2 and on which functions assigned to the switches Ie 1 and Ie 2 are described are displayed. The icons Ie 3 and Ie 4 are selectively displayed. The switch assignment screen S 6 displays the icons 244 , 254 , 264 , 274 , and 284 , corresponding to the command buttons 24 to 28 , at the upper end.
[0129] While the switch assignment screen S 6 is displayed, the operator selects the desired icon Ie 3 or Ie 4 by operating the encoder dial 22 , and presses the enter button 23 . Thus, the display content of the selected icon can be scrolled with the encoder dial 22 . Then, the operator selects a desired function by operating the encoder dial 22 , and presses the enter button 23 . Then, the selected function is assigned to the switch described on the icon displayed on the left side.
[0130] As an example, in FIG. 23 , the sprayer spraying start/stop is assigned to the working machine lifting/lowering switch 173 . More specifically, the spraying starts when the working machine lifting/lowering switch 173 is slid upward, and stops when the switch is slid downward. The boom lifting/lowering adjustment is assigned to the working machine lifting/lowering fine-control switches 174 . More specifically, the boom is lifted when the upper one of the working machine lifting/lowering fine-control switches 174 is pressed, and is lowered when the lower one of the switches is pressed.
[0131] As described above, the desired functions for operating the currently interlocked working machine are assigned to the switches (the working machine lifting/lowering switch 173 and the working machine lifting/lowering fine-control switches 174 ) provided to the transmission lever 172 . Thus, the operator can easily operate the assigned functions at hand without releasing his or her hand from the transmission lever 172 for operating the spraying controller 179 or the boom operation controller 180 , and thus can enjoy a less cumbersome operation.
[0132] When the interlocked working machine is a sprayer, two types of control, including constant vehicle speed control and constant spraying pressure control, can be performed. In the constant vehicle speed control, the vehicle speed is kept constant with the spraying pressure adjusted, when the spraying amount is changed. In the constant spraying pressure control, the spraying is performed with a constant spraying pressure with the vehicle speed adjusted, when the spraying pressure is changed.
[0133] FIGS. 24A and 24B area schematic view illustrating both types of control in a case where the spraying amount is increased, and includes 24 A illustrating the constant vehicle speed control, and 24 B illustrating the constant spraying pressure control. As illustrated in FIG. 24A , in the constant vehicle speed control, the vehicle speed is automatically maintained to be constant and the spraying pressure automatically rises, when the spraying amount per target acreage is increased. As illustrated in FIG. 24B , in the constant spraying pressure control, the vehicle speed automatically drops and the spraying pressure is automatically maintained to be constant, when the spraying amount per target acreage is increased. The constant spraying pressure control involves no change in the particle size and no change in the spraying state even when the spraying amount is changed, and thus can achieve more accurate work.
[0134] Which one of the two types of control is performed can be set by the operator in advance. The control modes can be set by using the display 2 , for example. When the tractor setting (icon Ia 3 ) is selected and determined with the first home screen S 3 , various setting items for the tractor 1 are displayed. The setting on the sprayer control mode is called therefrom. Thus, a control mode selection screen S 7 as illustrated in FIG. 25 is displayed.
[0135] The control mode selection screen S 7 displays two icons If 1 and If 2 on which the selectable control modes are described, and a green point image If 3 is displayed on the icon of the set control mode in an overlapping manner, so that the set control mode can be identified. The control mode selection screen S 7 displays the icons 244 , 254 , 264 , 274 , and 284 , corresponding to the command buttons 24 to 28 , at the upper end.
[0136] On the control mode selection screen S 7 , the operator selects the desired icon If 1 or If 2 by operating the encoder dial 22 , and presses the enter button 23 . Thus, the green point image If 3 is displayed on the right side of the selected icon, and thus the control mode described on the icon is set. FIG. 25 illustrates a state where the constant vehicle speed control mode is set.
[0137] While the tractor 1 before starting the work is stopped, the operator can set the spraying amount, appropriate vehicle speed, and appropriate spraying pressure. The position of the transmission lever 172 (the traveling vehicle speed information) can be checked on the sprayer operation panel 178 while the tractor 1 is stopped, and thus the traveling can be started after the position of the transmission lever 172 is simply adjusted.
[0138] When a broadcaster is the currently interlocked working machine, the broadcaster spraying start/stop function or the broadcaster spraying amount adjustment function can be assigned to the working machine lifting/lowering switch 173 and the working machine lifting/lowering fine-control switches 174 . The assignment is invalid when the working machine is not interlocked.
[0139] A function assigned to each switch can be set by the operator in advance by using the display 2 , for example. When the tractor setting (icon Ia 3 ) is selected and determined on the first home screen S 3 , various tractor setting items are displayed, and broadcaster switch assignment setting is called therefrom. Thus, a switch assignment screen S 8 as illustrated in FIG. 26 is displayed.
[0140] On the switch assignment screen S 8 , two icons Ig 1 and Ig 2 on which names of switches that can be assigned are displayed, and icons Ig 3 and Ig 4 displayed on the right of the icons Ig 1 and Ig 2 and on which functions assigned to the switches Ig 1 and Ig 2 are described are displayed. The icons Ig 3 and Ig 4 are selectively displayed. The switch assignment screen S 8 displays the icons 244 , 254 , 264 , 274 , and 284 , corresponding to the command buttons 24 to 28 , at the upper end.
[0141] While the switch assignment screen S 8 is displayed, the operator selects the desired icon Ig 3 or Ig 4 by operating the encoder dial 22 , and presses the enter button 23 . Thus, the display content of the selected icon can be scrolled with the encoder dial 22 . Then, the operator selects a desired function by operating the encoder dial 22 , and presses the enter button 23 . Then, the selected function is assigned to the switch described on the icon displayed on the left side.
[0142] As an example, in FIG. 26 , the broadcaster spraying start/stop is assigned to the working machine lifting/lowering switch 173 . More specifically, the spraying starts when the working machine lifting/lowering switch 173 is slid upward, and stops when the switch is slid downward. The spraying amount adjustment is assigned to the working machine lifting/lowering fine-control switches 174 . More specifically, the spraying amount is increased when the upper one of the working machine lifting/lowering fine-control switches 174 is pressed, and is decreased when the lower one of the switches is pressed.
[0143] As described above, the desired functions for operating the currently interlocked working machine are assigned to the switches (the working machine lifting/lowering switch 173 and the working machine lifting/lowering fine-control switches 174 ) provided to the transmission lever 172 . Thus, the operator can easily operate the assigned functions at hand without releasing his or her hand from the transmission lever 172 for operating the broadcaster controller, and thus can enjoy a less cumbersome operation.
INDUSTRIAL APPLICABILITY
[0144] The present invention can be used for work vehicles such as a tractor for farm work and a wheel loader for construction work.
REFERENCE SIGNS LIST
[0000]
1 tractor (work vehicle)
3 control device (control unit)
21 liquid crystal panel (display unit)
22 encoder dial (operation unit)
23 enter button (operation unit)
24 command button (operation unit)
25 command button (operation unit)
26 command button (operation unit)
27 command button (operation unit)
28 command button (operation unit)
172 transmission lever
173 working machine lifting/lowering switch (switch)
174 working machine lifting/lowering fine-control switch (switch)
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The objective of the present invention is to provide a work vehicle where an operator can, on the work vehicle side, confirm which working machine is engaged and set which working machine to engage. A tractor, to which a working machine can be mounted, is provided with: a liquid crystal panel selectably displaying an engageable working machine mounted and displaying the currently engaged working machine so as to be identifiable; an operation unit (encoder dial, enter button, and command buttons) for carrying out selection and determination operations for the working machine displayed on the liquid crystal panel; and a control device that, when a determination operation is carried out by the operation unit for a desired working machine, disengages the currently engaged working machine, and configures the working machine for which the determination operation has been carried out to be engaged.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of application Ser. No. 10/129,374 filed May 6, 2002 now U.S. Pat. No. 7,806,999 by the inventor herein and entitled Metal and Metal Oxide Granules and Forming Process which is a 35 U.S.C. §371 of PCT IB01/01921 filed Oct. 15, 2001 and claims the benefit of a foreign priority date of Oct. 26, 2000 based on South African Provisional Patent Application No. 2,000/6014.
BACKGROUND OF THE INVENTION
THIS invention relates to a process for producing granules containing a homogenous mixture of metal flakes and/or metal powder and metal oxide powder, and to granules containing a homogenous mixture of metal flakes and/or powder and metal oxide powder.
Metal and metal oxide flakes and powders and mixtures of metal powders such as those described in South African patent no. 96/3387 are used as sensitisers and energisers in explosives compositions. A problem with this type of metal powder is that when it is transported, the powder is compacted in the bottom of the container in which it is carried, making it difficult to unload the powder from the container.
This is particularly troublesome when metal powders are mixed via an auger into an explosives composition from a feedbin, in situ, from a mixing truck. Compacted powder in the bottom of the feedbin causes caking and hanging up, the metal oxides separate and an incorrect amount of powder, or composition of metal powder, is added to the composition. This leads to an inconsistent mixture throughout the volume of the explosives composition, which means that the explosives composition is less effective.
U.S. Pat. No. 4,256,521 discloses a method of forming granules from aluminium powder having a high proportion of fines of a size less than 80 microns, using a synthetic resin as a binder. However, this patent does not disclose a method of forming a metal and metal oxide composition into a granule.
It is an object of this invention to provide a granule made from a metal and metal oxide composition, that is useful (in particular) as a sensitiser and/or energiser in explosives compositions.
SUMMARY OF THE INVENTION
A first aspect of the invention relates to granules comprising a homogenous mixture of metal flakes and/or powder metal and metal oxide powder, and a binder.
The metal flakes are typically less than 0.35 mm, usually from 0.05 to 0.35 mm, in size and the metal and metal oxide powder consists of particles that are less than 10 microns in size.
Typically, the granules include more than 10%, by weight, metal oxide.
The granules may include up to 90%, by weight, metal oxide.
The metal flakes and/or metal powder and metal oxide powder may comprise Al or Al alloy such as Al/Mg, and Al 2 O 3 and other metal oxides such as Fe 2 O 3 , MnO 3 or MgO 2 , preferably Fe 2 O 3 .
Advantageously, the Fe 2 O 3 and Al are present in a ratio of at most 3:1, by mass.
The metal flakes and/or metal powder and metal oxide powder are preferably obtained from waste, typically aluminium dross and iron oxide fines.
Advantageously, the granules are in the form of porous prills.
Porous prills for use in explosives compositions typically have a free flowing apparent density of from 0.40 to 1.8 gm/cm 3 , preferably about 1.0 to 1.5 gm/cm 3 , most preferably about 0.9 gm/cm 3 and advantageously have a porosity of from 40% to 60%. The granules may vary in size from 300 to 6000 microns, typically from 30 to 900 microns.
The binder may be selected from polymers, polyalkylene carbonates, resins etc. A typically binder is a starch-based aqueous binder composition. Usually, the binder will not exceed 10%, by weight, of the composition. Another preferred binder is sodium silicate.
The granules may also include fluxing compositions such as metal salts, resins such as guar gum, Shellac or ladotol and other stearins to render the granule water resistant and resistant to decay, and sensitisers such as expanded polystyrene, micro-balloons, and glass to modify the density of the granules.
According to the second aspect of the invention there is provided an explosives composition comprising from 2% to 50%, by weight, of the metal and metal oxide porous prills described above, from 2% to 7% by weight of a fuel, typically an organic fuel, and from 50% to 95%, by weight, ammonium nitrate.
In the case of a dry ANFO explosive, the explosive composition typically includes 50% to 94% by weight of the composition ammonium nitrate porous prills, 5% to 6% by weight of the composition fuel oil and 5% to 30% by weight of the composition metal and metal oxide porous prills described above.
In the case of heavy ANFO blends and doped emulsion blends, the composition typically comprises 30% to 90% emulsified ammonium nitrate, 20% to 50% ammonium nitrate prills and 3% to 13% metal and metal oxide porous prills as described above.
A third aspect of the invention relates to a process for producing granules containing a homogenous mixture of metal flakes and/or metal powder and metal oxide powder, the process including the steps of:
1 forming a homogenous blend of finely ground metal flakes and/or metal powder and metal oxide powder in a blender; 2. adding the blend, together with a binder, a granulator to form granules containing a homogenous blend of finely ground metal flakes and/or metal powder and metal oxide powder; and 3. drying the granules.
Advantageously, an adherent, typically an organic fuel such as diesel or oleic acid, is added to the homogenous blend, to form an adhered homogenous blend which is added to the granulator.
The metal flakes, metal powder and metal oxide powders may include Al and Al 2 O 3 and other metal oxides such as Fe 2 O 3 , MnO 3 or MgO 2 , preferably Fe 2 O 3 .
The metal flakes, metal powder and metal oxide powder are preferably obtained from waste, typically aluminium dross and iron oxide fines.
The aluminium dross is processed to form aluminium flakes and powder and metal oxide powder. The aluminium content of the mixture is determined and sufficient iron oxide is added to the mixture to form a ratio of Fe 2 O 3 to Al of at most 3:1.
Admixtures such as micro-balloons, coal dust and magnesium may be added to the mixture in step 1 to modify the sensitivity, reactivity and ignition temperature of an explosive composition into which the granules are added.
Advantageously, the dried granules are separated and classified according to size after step 3.
The dried granules may be coated with a water-resistant compound.
BRIEF DESCRIPTION OF THE DRAWING
The invention will now be described in more detail, by way of example only, with reference to the accompanying drawing which shows a schematic diagram of a process according to the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Metal and metal oxide powders and flakes to be processed in accordance with the invention include metal flakes and metal powders for use in the explosives industry, and also for use in pyrometallurgy (hot-topping and de-oxidants), pyrotechnics, solid fuels, and in the manufacture of metal salts.
The granules of the invention are made from a homogenous mixture of metal flakes and/or metal powder and metal oxide powder. The granules include a binder which holds the powder and flakes together, with the powder in close proximity to the flakes. The granules may also include other constituents such as sensitizers, and may be coated with water resistant compounds.
The metal flakes and/or metal powder comprise finely ground aluminium or an alloy of aluminium such as Al/Mg. The metal oxide is selected from Al 2 O 3 , Fe 2 O 3 , MnO 3 or MgO 2 , or a mixture thereof. Typical mixtures of metal and metal oxide powders and/or flakes are described in South African patent no. 96/3387, the disclosure of which is incorporated herein by reference.
It is of the utmost importance that the metal flakes are in a homogenous mixture with the metal and metal oxide powder. The homogenous mixture ensures intimate contact between the metal and the metal oxide, which acts as fuel when the granules are used, for example as a sensitiser in explosives compositions. If there were no homogenous mixture, the metal oxide would form unreactive pockets within the granule, which negatively affects the combustion of the granule.
The Al flakes and Al 2 O 3 powder is obtained from residues in the form of dross, skimmings, shavings and grindings from aluminium and aluminium production from primary and secondary operations which are often destined for landfill. The Fe 2 O 3 powder is obtained from iron oxide fines obtained, for example, from processes carried out on the tailings from the mining of ore bodies or other production processes. The other metal oxides (MnO 3 and MgO 2 ) may also be obtained from waste.
Referring to the drawing, in accordance with the invention, aluminium dross 10 is milled in an air swept ball mill 12 to produce Al flakes having a maximum width of 0.05 mm to 0.35 mm and a fine powder with particles of the size of 10 microns and less. The powder is made up from Al, Al 2 O 3 and small amounts of inert compounds such as silica and metal salts. Air extraction in the air swept ball mill removes some of the very finely ground Al 2 O 3 powder and the inert compounds. The amount of Al and Al 2 O 3 in the powder and flakes so-formed varies from one source of aluminium dross to another. A mixture of powder and flakes so-formed may comprise as little as 10% by weight Al and up to 98% by weight Al, the rest being made up mainly by Al 2 O 3 . Where the mixture of powder and flakes so-formed has a very low Al content, for example less than 25% by weight thereof, it is necessary to increase the Al content by adding higher grade Al flakes thereto. The higher grade Al flakes may be obtained from shavings, or grindings from aluminium production. The metal and metal oxide powder and flakes so-formed having an Al content of greater than 25%, by weight, and may be used as is, or mixed with another metal oxide powder 14, typically Fe 2 O 3 powder obtained from iron oxide fines, to provide a composition of metal and metal oxide powder and flakes which may be used in explosives compositions. Ideally, Fe 2 O 3 is added to ensure a stoichiometric ratio of Fe 2 O 3 to Al of 3:1. A lower ratio of Fe 2 O 3 to Al may be suitable in applications where additional gas energy is required in an explosives composition.
Table 1 below shows the amount of Al and Al 2 O 3 in milled Al obtained from Al dross, and Table 2 below shows compositions of metal flakes and metal oxide powder which are to be formed into the granules of the invention. Composition 1 comprises Al and Al 2 O 3 . Compositions 2 to 5 comprise Al, Al 2 O 3 and Fe 2 O 3 .
TABLE 1
Milled Dross
1
2
3
4
5
% Al in milled Al by weight
80
50
75
50
30
% Al 2 O 3 in milled Al by weight
15
40
20
40
65
% Inerts by weight
5
10
5
10
5
TABLE 2
Composition
1
2
3
4
% milled Al by weight
100
40
65
40
% Fe 2 O 3 powder by weight (97% purity)
0
60
35
60
% Al 2 O 3 in composition by weight
15
16
13
26
% Al metal in composition by weight
80
20
49
12
% metal oxide in composition by weight
15
76
48
86
% inert compounds by weight
5
4
3
2
The metal and metal oxide powder and flakes composition will generally be made up by 10% to 90%, by weight, Al and 10% to 90%, by weight, metal oxide.
The abovementioned compositions of metal flakes and powder and metal oxide powder are prepared in bulk quantities (i.e. 1 to 10 tons at a time). To produce compositions 2 to 5 (ie the compositions that contain Al, Al 2 O 3 and another metal oxide (Fe 2 O 3 )), bulk quantities of the milled Al and Al 2 O 3 flakes and powder are mixed with bulk quantities of the Fe 2 O 3 powder. In these circumstances, the amount of Al in the milled Al and Al 2 O 3 flakes and powder derived from aluminium dross is measured and the amount of Fe 2 O 3 powder added is altered according to the percent Al in the milled Al and Al 2 O 3 flakes and powder. Table 3 below shows the percentage of milled Al and Al 2 O 3 powder and flakes added to the total tonnage of the final composition of milled Al and Al 2 O 3 and Fe 2 O 3 , depending on the percentage Al therein.
TABLE 3
1
2
3
4
5
% Al purity in milled Al and
60
50
40
30
25
Al 2 O 3 flakes and powder
% Al and Al 2 O 3 flakes and
36
40
45
52
57
powder in Al and Al 2 O 3 and
Fe 2 O 3 composition
% Al in Al and Al 2 O 3 and
21
20
18
15
14
Fe 2 O 3 composition
The abovementioned compositions are then formed into granules, typically porous prills, in a granulator using a suitable binder. It is most important that the granules contain a homogenous mixture of flakes and powder, so that the metal is in intimate contact with the powder to ensure that the metal reacts with the metal oxide, in use. If there is no homogeneity, clusters of powder would result, and this negatively effects the reaction of the metal with the metal oxide.
Before granulation, the composition of metal flakes and powder and metal oxide powder are then blended in a blender 16 (for example a ribbon blender or paddle mixer typically running at 30-100 rpm), to form a homogenous mixture of metal flakes and powder and metal oxide powder. An adherent 18 (typically an organic fuel such as diesel or oleic acid), is added to the blender to adhere the metal flakes and powder and metal oxide powder together in an homogeneously blended mixture. Fluxing agents such as metal salts may be added to the blend for pyrometallurgical applications. Other sensitisers such as expanded polystyrene, micro-balloons, glass etc. may be added to the blend to increase the sensitivity of an explosives composition in which the granules are used, and also to alter the density of the granules.
From the blender 16 , the homogenous blend is sent to a granulator 20 . The granulator 20 includes a stainless steel drum which is liquid cooled, to ensure that the composition remains cool during the granulation process (heat caused by friction in the granulator could result in an exothermic reaction). Housed in the drum is a series of mixer blades located on a central driven shaft. The mixer blade design and angle, and the linear speed of the blades are selected to determine the size and porosity of the granules (which are porous prills).
An operator begins the granulating process by continuously feeding the adhered blended mixture into the granulator 20 , while spraying a binder 22 into the granulator 20 at the same time. The operator will control the size of the granules and porosity thereof by adjusting the rate at which the homogenous blend and binder is fed into the granulator, and the speed of the blades. For small granules of a high porosity, the granulator is run at a high speed of 800-1000 rpm. The operator monitors the build-up of granules in the granulator and the pneumatic valve on the side of the granulator is opened periodically to discharge green granules from the granulator.
The design of the granulator 20 also permits the inclusion in the production process of admixtures such as density modifiers once the binders have been introduced into the compositions being prilled.
Many binders may be used. Binder properties which are essential in production are as follows:
1. The binder must mix uniformly with the composition. 2. Provide sufficient green strength to allow for further processing. 3. The binder must not decompose during the processing of the green body. 4. The binder in most application must burn out completely (in all atmospheres preferably leaving minimal ash residue).
Binders such as Dextrin, starch, polyalkylene carbonates, resins and many others, can be used in the agglomeration and production of porous prilled granules. The choice of binder used is determined by the end use of the prill. Aqueous dextrin has been found to be useful in the production of prills according to the invention for use in explosives compositions, where very finely divided metals and metal/metal oxide powders are prilled.
Sodium silicate may be used as a binder in explosives and pyrometallurgical applications and high alumina cements in order to maintain prill integrity in rough handling conditions and amongst other characteristics, slow down or accelerate the ignition of the compositions being introduced. Certain binders have the chemical attributes required to modify reaction/ignition temperature without admixtures such as many metal salts. They are also water and solvent resistant and do not require that the prilled products need to be additionally coated following production.
Following the granulating/prilling process in the granulator 18 , the green granules are conveyed to a vibrating screen 24 (if desired), which assists in breaking any agglomerated green product, then to a rotary drier 26 , and lastly to a final infra-red drying stage 28 .
The granules may be produced with, or coated with, water-resistant agents such as resins for example Shellac or ladotol to render the granule water-resistant for particular applications. However, in some applications, for example for use in emulsion explosives, the granules are not made water resistant, so that the granules break down when added to the emulsion mixture.
Granules so produced may vary in size from 30 microns to 30 mm in diameter.
Preferred granules of the invention are porous prills.
The size of granules for explosives compositions could be from 300 microns to 6 mm, with a free flowing apparent density (ASTMSTD) of from 0.4 to 3.0 gm/cm 3 . The usual density for a bulk explosives mix is about 0.92 gm/cm 3 and the porosity of the granules may be from 40% to 60%.
In a preferred embodiment, the metal and metal oxide granules are used as a sensitizer or energiser in dry ANFO mixes and heavy ANFO mixes, doped emulsion blends and packaged explosives preparations. Typically, the granules are added in an amount of from 2% to 30% by weight (usually not more than 10% by weight) of the explosives composition which further comprises from 2% to 5% by weight of fuel, typically an organic fuel such as diesel, and from 30% to 90% by weight of the composition ammonium nitrate. Explosive compositions normally contain about 85% to 96% ammonium nitrate and the presence of the granules of the invention can allow for a reduction of ammonium nitrate of up to 50%, of the composition.
Table 4 below provides examples of typical dry ANFO mixes and Table 5 below provides examples of typical heavy ANFO blends utilising the homogenous granules of metal flakes and powder and metal of the invention.
TABLE 4
1
2
3
4
5
6
Ammonium Nitrate (porous prills)
65
70
75
80
85
90
% by mass of the composition
Fuel Oil
5.5
5.5
5.5
5
5
3
% by mass of the composition
Metal Powder Granules
29.5
24.5
19.5
15
9.5
7
% by mass of the composition
Al Metal
20
20
20
20
20
20
% by mass of the metal powder granule
Al 2 O 3
16
16
16
16
16
16
% by mass of the metal powder granule
Fe 2 O 3
60
60
60
60
60
60
% by mass of the metal powder granule
Free Flowing Apparent Density of Metal
1.4
1.4
1.4
1.4
1.4
1.4
Powder Granules gm/cm 3
Size of granule microns
300-890
300-890
300-890
300-890
300-890
300-890
TABLE 5
1
2
3
4
5
6
7
8
Emulsified Ammonium Nitrate
55
60
60
60
60
65
65
65
% by mass of the composition
Ammonium Nitrate Porous Prill
40
34
33
32
31
25
24
24
% by mass of the composition
Metal Powder Granules
5
6
7
8
9
10
11
10
% by mass of the composition
Al Metal
20
20
20
20
20
20
20
80
% by mass of the metal powder granule
Al2O3
16
16
16
16
16
16
16
20
% by mass of the metal powder granule
Fe2O3
60
60
60
60
60
60
60
0
% by mass of the metal powder granule
Free Flowing Apparent Density of Metal
1.4
1.4
1.4
1.4
1.4
1.4
1.4
1.2
Granules gm/cm3
Size of granule microns
300-890
300-890
300-890
300-890
300-890
300-890
300-890
1000-2000
The granulated metal powder granules made according to the invention have many advantages including:
1. The flow-handling of the granules is far better than that of powder and stops caking and hanging up of the product in feed bins and improves calibration and delivery of the product, with less wear on pumps and augers; 2. As the metal powder is bound in granules, there is much less dust; 3. There is no segregation of the aluminium, aluminium oxide and iron oxide in the granule, ie. the granule contains the metal components in the powder homogeneously; 4. The compressive strength of the granules can be varied (by varying the amount and type of binder), according to need; 5. The granules can be classified into particular sizes for particular applications; 6. It is convenient to add desired compounds or compositions to the powder, prior to granulation to alter the characteristics of the granules. Furthermore, certain admixtures can be added prior to granulation to modify the oxygen balance which affects the energy yield of the granule. 7. When used in an explosives composition, the granules reduce the density of the composition and there is better distribution of the sensitizer/energiser within the explosives composition. Also, the density of the granules can be adjusted to adjust the density of the explosives composition. Such compositions are also more stable and safer to store, handle and transport. 8. A starch-based aqueous binder composition is relatively inexpensive and the starch combusts and thus plays an active role in an explosives reaction when the granules are used in explosives compositions. 9. The granules can be coated to make them resistant to water when water dissolvable binding systems are used in explosive compositions. 10. If there are any free heavy metals in the powdered composition which may affect the base product stability, for example, PH once prilled, the binder composition, which is stable and additional coating thereafter will prevent any potential emulsion breakdown, in the case of explosives compositions.
Example 1
Aluminium dross was obtained from the production of aluminium alloys from secondary and primary metal. The aluminium dross was milled in an air swept ball mill to produce aluminium flakes having a maximum width of 0.05 mm to 0.1 mm and a fine powder which included Al, Al 2 O 3 and small amounts of inert compounds such as silica. Air extraction in the air swept ball mill removed some of the very finely ground Al 2 O 3 powder and inert compounds. The flakes and powder so-produced were tested and found to contain 50% Al, the rest being made up mainly by Al 2 O 3 . 400 kg of this Al and Al 2 O 3 powder and flakes was then mixed with 600 kg of Fe 2 O 3 powder obtained from iron oxide fines to provide a composition of metal and metal oxide powder containing 20%, by mass, Al, 20%, by mass, Al 2 O 3 , and 60%, by mass, Fe 2 O 3 .
The metal powder composition was sent to a ribbon blender which was running at a speed of 30 rpm, to form it into a homogenous mixture of metal flakes and powder and metal oxide powder. 3 kg of diesel was added to the blender to adhere the composition together, in a homogenous blend.
Example 2
The adhered homogenous composition described in Example 1 was then mixed with a starch-based aqueous binder to provide metal powder granules according to the invention.
The starch-based aqueous binder composition was formed from 40 parts by weight of a starch, namely dextrin yellow, 60 parts by weight water, 9 parts by weight of a thickener such as borax and 1 part by weight sodium hydroxide which is also a thickener. 0.4 kg of dextrin yellow, 0.09 kg of borax and 0.01 liter of sodium hydroxide solution was added to the solution to form the starch-based aqueous binding composition.
1000 kg of adhered homogenous composition described in Example 1 was fed into a high-speed granulator. The blade design of the mixer was designed to provide a maximum shearing effect in order to produce small diameter granules. The mixer was operated at a speed of 920 rpm (the high speed ensured a high porosity of the granules) and 100 kg of the starch-based binder composition described above was added to the granulation mixer from a sprayer, at 30 ml/m. Granules were formed in 5 minutes.
From the granulator, the granules were fed into a tumbling mill which reduced agglomerates and then into a rotary dryer which was operated at a temperature of 250° C. From the rotary dryer, the dried granules were fed into a multi-deck vibrating screen which classified the granules into different sizes.
From the vibrating screen, the classified granules were introduced into a flow mixer which coated the granules with a water resistant agent (oleic acid).
The granules so produced had a free flowing apparant density of 1.4, a porosity of 45%, and a diameter of from 30 to 6000 microns.
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This invention relates to granules comprising a homogenous mixture of metal flakes and/or metal powder and metal oxide powder, and a binder. The invention also relates to a process for producing such granules. The process includes the step of forming a mixture of metal flakes and/or metal powder and metal oxide powder, forming the mixture into a homogenous blend, adding the blend, together with a binder, to a granulator to form granules, and drying the granules. Granules so formed containing aluminum, aluminum oxide and iron oxide find particular use as sensitizers and energizers in explosives compositions.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to stacking towers and more particularly to a pollution control system for use with a stacking tower.
2. Prior Art
Many large coal users store their coal in large stockpiles in an open area to achieve maximum accessibility for management of the coal. This storage may be accomplished with the aid of a steel or concrete cylindrical stacking tower having a series of vertically spaced pairs of openings. Each of the openings in a pair are located in opposed sections of the tower wall and the pairs are usually spaced five to six feet vertically. The height of the stacking tower depends on the size of the stockpile desired, with most towers measuring about one hundred feet.
The stacking tower is the most economical system for large tonnage coal storage and therefore most consultants and engineers recommend its use. Unfortunately, the stacking tower is not environmentally clean and some environmental agencies have taken a firm stand against the open stockpiling of coal because of the large volume of fugitive dust generated by the stockpiling operation.
The stacking operation involves the conveyance of the coal to the top of the tower where it drops through the tower to grade level to start the stockpile. The coal flows diametrically through the openings in the tower and is evenly distributed to the pile. This process generates large volumes of dust which emanate through openings in the tower. Additionally, ground winds blow through the openings in the tower and compound the problem.
Some of the fugitive dust will settle out within a few hundred feet of the stacking tower, however, large quantities of airborne particulates will remain suspended. The airborne particulates are the primary pollution factor which is most highly objectional for reasons of health and safety. As a result, standards have been established at various levels of the government designed to control this pollution source and inflict heavy financial penalties for violations.
Present solutions to fugitive dust control for coal stockpiling operations are very limited. The dust control options which are available and recognized by some pollution control agencies are very costly in terms of initial investment and operational expense. Foam injected dust suppressants are but one example. Another positive approach to this problem is to contain the stockpiling operation in an enclosed silo. In both cases the cost is prohibitive.
The present energy crisis has created a renewed interest in and a greater demand for coal. The instant invention will allow the modification of existing stacking towers so that environmental regulations may be followed and the cost of coal storage kept at a reasonable level.
It is therefore an object of this invention to provide a stockpiling tower compatible with pollution laws and regulations that is cost effective.
It is another object of the invention to provide a versatile system which can control the problem of fugitive dust under a variety of ambient conditions during various stages of the stacking operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a stacking tower incorporating the features of this invention;
FIG. 2 is an exploded view of a gravity door assembly used in the present invention;
FIG. 3 is a schematic cut-away illustration of the tower and pollution control assembly under maximum air infiltration conditions; and
FIG. 4 is a schematic cut-away illustration of the tower and pollution control assembly under minimum air infiltration conditions.
SUMMARY OF THE INVENTION
The invention is directed to an improvement for stacking towers which receive and deposit solid material into a stockpile at the base of the tower. More particularly, the invention provides a pollution control system which collects and filters dust laden air generated during the normal operation of such a stacking tower. The tower itself is defined by an upper loading zone and lower discharge zone. The solid material is delivered into the loading zone and is funneled through a venturi chute for deposit within the discharge zone of the tower. A series of vertically spaced pairs of openings in opposed sections of the walls of the tower are provided for the passage of the solid material from the tower to the stockpile. These openings have closing means consisting of a gravity door and wind deflecting means in the form of a shield.
The pollution control system which is in communication with both zones of the stacking tower includes two baghouses and two exhaust fans. Depending on several different factors, such as ambient wind speed and the level of the stockpile, either one or both of the baghouse and fan subsystems may be used. The pollution control system generates and maintains a negative pressure condition within the tower and an air flow into the baghouses. The volume of air passing through the tower can be controlled by a modulating damper at the upper portion of the discharge zone. The tremendous level of dust generated within the tower during the loading process is captured by this negative pressure air flow and drawn out of the tower into the baghouse. The air laden dust is filtered and discharged while the dust is transported to a dust conditioner for agglomeration and recovery.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, a stacking tower for recovery and depositing solid material in a stockpile and the pollution control system of the instant invention are generally indicated by the numeral 1. The vertical stacking tower 2 comprises an upper loading zone 3 and a lower discharge zone 4. Included in the discharge zone 4 are a series of vertically spaced pairs of openings 5a thru 5j, each pair being located in opposed sections of the wall of the tower 2. The openings are completely enclosed by a gravity door assembly which will be explained hereinafter. The pollution control system of the instant invention is situated on a platform atop the tower 2 and is generally indicated by the numeral 6. It is preferably comprised of two baghouse dust collection systems 7 and 7' which are in communication with the tower 2 through ductwork 7" therebetween. Two exhaust fans 8 (located behind the baghouses) are used to create a negative pressure within the tower, so that dust liberated in the loading and stacking operations of the tower are drawn from the tower and collected in the baghouses 7 and 7'. While it may be possible to accomplish similar results with a single bag system, the value of a two baghouse system will become obvious in the discussion of FIGS. 3 and 4. In order to maintain a constant volume of air flow through the tower and into the pollution control system, a modulating air damper 9 is located near the top of the discharge zone 4 of the tower 2. The hatched line 10 extending diagonally from the upper section of tower 2 to the grade 11 illustrates the shape and size of a stockpile which can be formed by a stacking tower.
The gravity door assembly illustrated in FIG. 2 consists of a frame 12 with a door 13 attached by a hinge 14 or the like at its top horizontal edge for pivotal movement out away from the frame sill 15. The door assembly also includes a wind deflector mounting plate 16 situated between the wall of the tower 2 and the door frame 12 and a wind deflector hood or shield 17 which may partially surround and extend beyond frame 12. The mounting plate 16 is affixed to tower 2 about an opening 5 and provides means for supporting the frame 12 and shield 17. The wind deflector shield 17 has a rectangular base member 18 which extends from the sill 15 and vertical members 19 and 19' which extend from the forward edge of each side of base member 18 to the top of the mounting plate 12. The side members are preferably shaped in the form of a right angle triangle as shown.
A door assembly is superimposed over each opening in the discharge zone of the tower 2 and in its rest condition closes an opening to maintain the negative pressure of the pollution control system within the tower. The wind deflector shield 17 prevents ambient air currents, in the open atmosphere in which the stacking is done, from lifting the door out of its rest condition. The door 13 is free to swing out away from the opening 5 whenever a force f is applied to the rearwardly facing surface of the door. The force f is generated by the weight of material within the tower 2 during the coal discharge operation.
Turning now to FIG. 3, the operation of the pollution control system 6 at the start of a stockpile is illustrated. The vertical stacking tower 2 is divided into an upper loading zone 3 and a lower discharge zone 4 by a venturi chute 20. The upper loading zone 3 includes a charging means such as a conveyor 21 by which solid material such as coal 22 is delivered into the head chute cavity 23. The coal 22 funnels down through the venturi chute 20 into the lower discharge zone 4 which has a series of vertically spaced pairs of openings, openings 5a thru 5d being illustrated. As the discharge zone 4 begins to fill with coal 22, the doors 13 will be forced open and the coal will pour through a pair of openings 5a and start a coal stockpile 24 about the bottom of the tower on grade 11. The size of the stockpile is controlled by the height of the tower and the volume of the coal conveyed thereto. The stockpile will eventually increase in height until the coal 22 can no longer flow through the openings 5a, only one of which is illustrated. At this point, the coal 22 will continue to build up the stockpile 24 until it is level with openings 5b, at which time the entire process is repeated. This cycle will continue until the loading is terminated or the coal stockpile reaches the uppermost openings 5d of the tower.
The use of four pairs of doors is not to suggest the pollution control system is designed for use with only such a configuration or that a greater or lesser number of openings could not be utilized with the invention.
The discharge zone 4 is provided with means to permit the flow of makeup air into the tower as necessary. This means consists of an air damper 9 which can be modulated to adjust the volume of air flowing therethrough. Additionally, the openings 5 in the discharge zone are equipped with the wind deflector hood 17 and door 13 which repel high velocity ground winds and eliminate blow through across the tower.
Two operating modes will be described. FIG. 3 illustrates the pollution control system at the beginning of the stacking process when maximum air infiltration is encountered and FIG. 4 illustrates the pollution control system near the termination of stacking operation when minimum air infiltration is encountered with coal in both occurrences fed to the tower at a rate of 1450 tons per hour. The pollution control system, generally indicated by the numeral 6, is a dual system as was previously indicated, however for the sake of clarity only one of the two identical subsystems is illustrated and described.
The pollution control system 6 includes a baghouse 7 in communication with a collecting outlet in the upper region of the loading zone 3 by means of duct 25 and with a collecting outlet in the upper region of the discharge zone 4 by means of duct 26. An exhaust fan 8 is in communication with the baghouse through duct 27. The system 6 also includes a dust conditioner 28 and dust discharge 29.
A variety of components make up the air flow into the tower and include air infiltration through the two open doors through which the coal is being discharged, air infiltration around the closed doors, air entrained by the conveyor, air (950 CFM) being displaced as the volume of coal (1450 tons/hour) within the tower increases, ground winds in the vicinity of the stacking tower, and make up or bleed air for maintaining constant air volume flow through the dust collection system as provided by the damper.
FIG. 3 illustrates a condition of maximum air infiltration at the beginning of the stacking process when both subsystems of the pollution control system are on the line. It is estimated that with a wind velocity W of about 25 MPH near grade level, there would be 10,500 CFM of air infiltration through the open coal doors 5a as shown by the arrow marked A. There would be an additional air infiltration of 2,000 CFM through the remaining doors of the tower as shown by arrow C and 9,100 CFM of air would be entrained through the conveyor 21 at D. Two exhaust fans 8 will be drawing 25,000 CFM of air through the two baghouses 7 and discharging the air at E. The makeup air (2450 CFM) required to balance the system is provided through the modulating damper 9 at F. As the coal 22 is conveyed into the tower, the pollution control system 6 will be generating a negative pressure inside the tower 2 so that air flows from the tower into the baghouses 7. As the coal drops through the venturi chute 20, the air will counterflow upwardly into the pickup areas 30 and 31. Most of the potential airborne dust will be captured in the air flow and drawn out of the tower through ducts 25 and 26 into the baghouses 7. The dust will be filtered from the air and removed to a common dust conditioner 28 which is provided with injecting means 28' by which a liquid suppressant mixes with and agglomerates the dust for disposal. The conditioner may also be provided with means for jettisoning 29' the agglomerated dust modules into the stockpile 24 through discharge 29. As the coal flows diametrically through the open coal doors 13, the wind deflectors 17 over the gravity coal doors break the initial thrust of the wind and act as a hood for dust collection. As a result of this system most of the coal dust will be captured within the tower, thereby minimizing fugitive dust loss.
In FIG. 4, the stockpile of coal is nearly completed with the coal now being discharged through openings 5d. For illustrative purposes, the wind velocity W is now at 2 MPH. The volume of air G being entrained into the loading zone 3 by the conveyor is now at 7,100 CFM and since all but the uppermost pair of doors 5d are sealed by the stockpile, the air infiltration flow H is reduced to about 4,450 CFM. Under such minimum air infiltration conditions, only one fan and baghouse of the dust control system are on the line. The exhaust I from the single fan is about 12,500 CFM so no makeup air is required and the damper 9 is closed. It should also be noted that as the level of the stockpile rises, more air is displaced from the tower by the coal therein. The dust laden air withdrawn from the tower is filtered by a single baghouse and removed to the common conditioner 28 for processing.
During the stockpiling of coal by a stacking tower, a tremendous level of fugitive dust is lost into the atmosphere. The pollution control system herein described draws the potential airborne dust particulate from the tower for processing and disposal in a safe and efficient manner.
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An improved stacking tower is equipped with a dust pollution control system which maintains a negative pressure within the tower and comprises an exhaust means, dust collection and removal means and movable closure means for closing the discharge openings of the tower. A modulating air damper is also provided to adjust the volume of air passing through the tower.
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This application is a Continuation-In-Part of application Ser. No. 10/653,361 filed Aug. 28, 2003, now U.S. Pat. No. 7,014,875, which is in in turn a Continuation-In-Part of application Ser. No. 10/231,291 filed Aug. 30, 2002, issued as U.S. Pat. No. 6,638,554. The entire contents of each of the above-identified applications are hereby incorporated by reference.
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to a method of low-temperature and neutral-pH precooking for the production of corn flour and, more particularly, to one that achieves continuous partial hydrolysis of the insoluble heteroxylans, starchy and proteinaceus bran cell-walls while avoiding excessive pregelatinization with a xylanase, endoamylase and endoprotease blend as a processing aid during the manufacture of an instant corn flour for the elaboration of snack and tortilla foods.
2. Description of Related Art
The production of high-quality masa flour can be produced by conventional techniques only if the food-grade dent corn has the following characteristics: uniformity in kernel size and hardness, low number of stress-cracks and kernel damage and ease of pericarp removal during the lime-water cooking process. The mature kernel has four separable components, on a dry weight basis: tip cap (0.8-1.1%), pericarp or bran (5.1-5.7%), endosperm (81.1-83.5%), and germ (10.2-11.9%). In dry or wet-milling processes the bran includes the pericarp, tip cap, aleurone layer (isolated with bran) and adhering pieces of aleurone/starchy endosperm as well. A native corn bran contained starch (4-22%) and protein (5-8%) arising from the endosperm tissue and glycoprotein pericarp as well (Saulnier et al. 1995 and Hromadkova et al. 1995). Nixtamalized corn flour (NCF) is produced by the steps of alkaline cooking of corn, washing, milling the nixtamal and drying to give corn masa flour. This flour is sieved and blended for different product applications and it is usually supplemented with additives before packaging for commercial table or packaged-tortilla and snack production. Although the pericarp or bran is partially removed during the alkaline-cooking and washing process stages, there is still fiber left from the corn kernel (Montemayor and Rubio, 1983, U.S. Pat. No. 4,513,018). Whole Nixtamalized corn flour or masa flour can contain from 7-9% of total dietary fiber or bran with 6-8% mainly consisting of insoluble fiber on a dry basis (Sustain, 1997, U.S. Pat. No. 6,764,699).
The cell walls or non-starch polysaccharides (NSP) are the major corn dietary fiber components and are composed of hemicellulose (heteroxylan or pentosan and β-glucan: 4.4-6.2%), cellulose (2.5-3.3%) and some lignin (0.2%). According to Watson (1987: Tables Iv and VII), the corn pericarp/tip cap makes up about 5-6% and aleurone-endosperm has about 2% of the kernel dry weight. This pericarp also contains 90% insoluble fiber (67% hemicellulose and 23% cellulose) and only 0.6% soluble-fiber (soluble-arabinoxylan and β-glucan). It is estimated that dietary fiber in both pericarp or bran (4.9%) and endosperm (2.6%) make up 80% of the total dietary fiber. The corn insoluble fiber is mainly found in the pericarp and endosperm (aleurone and starchy) which make up 68% of the total dietary fiber (9.5% in a dry-weight basis). The corn bran layers comprise the outer (beeswing or hull), inner (cross and tube cells), nucellar layer and endosperm (aleurone and starchy) cell-walls. The innermost tube-cell layer is a row of longitudinal tubes pressed tightly against the aleurone layer. Next there is a very loose and open area called the cross-cell layer, which has a great deal of intercellular space. These areas provide capillary interconnections between all cells, which facilitate water absorption. The pericarp extends to the base of the kernel, uniting with the tip cap. Inside the tip cap there are spongy-branched cells openly connected with the cross-cells.
Unlike corn endosperm, in which soluble fiber amounts to 12% of the total fiber (4.1%), in whole wheat, soluble fiber represents 22% of total fiber (about 20% of the flour water-uptake is bound to the soluble pentosan fraction). Arabinoxylan is a complex polymer (20,000-170,000 Daltons) with a linear backbone of (1,4)-β-xylopiranosyl units to which substituents are attached through O2 and O3 atoms of the xylosil residues (mainly, α-L-arabinofuranosyl). This polymer is apparently linked to the cellulose skeleton in the corn cell wall by ester linkage cross-bonding through ferulic and diferulic acid (Watson, 1987). However, heteroxylan insolubility in corn bran might be due to protein-polysaccharide linkages (pericarp glycoproytein or extensin) and a highly branched structure (23% of the xylan backbone does not bear side-chains) as opposed to wheat bran (Saulnier et al., 1995).
During alkali-cooking and/or steeping, there are chemical and physical changes such as nutrient losses along with partial pericarp or bran removal, degradation of the endosperm periphery with starch gelatinization/swelling and protein denaturation in the precooked corn kernel. The most important nutritional modifications are: an increase in the calcium level with improvement in the Ca to P ratio, a decrease in insoluble dietary fiber and zein-protein, a reduction in thiamin and riboflavin, an improvement of the leucine to isoleucine ratio reducing the requirement for niacin, and leaching the aflatoxins into the wastewater (Sustain, 1997).
The known cooking methods (batch or continuous) have been proposed as the critical variables (Sahai et al., 2001) which determine soluble-solid loss (1% to 1.6% COD) in limewater residue for anaerobic biodegradation (Alvarez and Ramirez, 1995). Dry solid matter (1.5%-2.5%) includes an average of 50-60% dietary fiber, 15-20% ash, 15% starch, 5-10% protein and 5% fat. Bryant et al., (1997) showed an optimum change in starch behavior at a lime level similar to the corn masa industry where starch gelatinization indicators (enzyme digestion, water retention capacity, starch solubility and DSC-peak temperature=69° to 75° C.) are increased with lime addition of 0% to 0.4%, peaking at 0.2%. They also found a peak-viscosity temperature reduction upon the addition of lime up to 0.5%, indicating faster granule swelling that requires less thermal energy. Corn pericarp nixtamalization (Martinez et al., 2001) has a first-order stage associated with a fast dissolution of hot-water soluble fractions as starch and pectin, and alkali-soluble fat. A second stage is due to a slow alkaline-hydrolysis of the hemicellulose-cellulose-lignin structure with a higher hemicellulose loss proportional to alkaline-pH concentrations.
Arabinoxylan degrading enzymes include xylanases (1,4-β-D-xylan xylanohydrolase, EC 3.2.1.8) and β-xylosidases (1,4-β-D-xylan xylohydrolase, EC 3.2.1.37). The former endoenzyme randomly hydrolyze the insoluble and soluble xylan backbone (EC 3.2.1.8) whereas the latter exoenzyme hydrolyze xylose from the non-reducing end of the xylose-polymer (EC 3.2.1.37). Xylose is not usually the major product and it is typically produced after xylobiose and xylotriose (smallest oligomer). Virtually all xylanases are endo-acting as determined by chromatography or their kinetic properties (substrate and product formation), molecular weight and pH (basic or acidic) or its DNA sequence (crystal structure). They can be structurally classified into two major families or isoenzymes (F or 10 and G or 11) of glycosyl hydrolases (Jeffries, 1996). F10 xylanases are larger, with some cellulase activity and produce low DP oligosaccharides (less specific); F11 are more specific for xylan and with lower molecular weight (i.e., B. Circulans and T. harzianum ).
In addition, the Enzyme Technical Association (ETA, 1999; FDA, 1998) classified as carbohydrases the following hemicellulases (trivial name): a) endoenzymes (EC 3.2.1.32=1,3-β-xylanohydrolase, 78=mannanohydrolase and 99=arabinohydrolase) and b) exoenzymes only attack branches on the xylose-polymer (pentosan), producing xylo-oligomers (EC 3.2.1.55=a-L-arabinofuranosidase) or producing acids (glucuronic-acid glycosilase and ferulic-acid esterase). Currently recognized endoenzymes (xylanases) and exoenzymes produced from A. niger (EC 3.2.1.8 and 37,55), A. oryzae (EC 3.2.1.8 or 32), B. subtilis (EC 3.2.1.99), and Trichoderma longibrachiatum (formerly reseei: EC 3.2.1.8) are Generally Recognized As Safe (GRAS; 21 CFR 182, 184 and 186) and require no further approval from the U.S. Food and Drug Administration or Recognized As Safe (RAS in Europe: Mathewson, 1998). However, direct and indirect food additives (i.e., packaging materials) are regulated in 21 CFR 172 and 174-178 as well. Secondary direct additives, a sub-class of direct additives, are primarily Processing Aids which are used to accomplish a technical effect during food processing but are not intended to serve a technical or as a functional additive in the finished food. They are also regulated in 21 CFR 173 (Partial List of Enzyme Preparations that are used in foods). Finally, all GRAS Substances produced through recombinant-DNA which were widely consumed prior to 1958, and which have been modified and commercially introduced after 1958 must comply with regulatory requirements proposed in 21 CFR 170.3 (GRAS Notice).
The benefits of using a commercial xylanase (endoenzyme) in cereal flours instead of a non-specific hemicellulase (exo- and endoenzyme) preparation are a reduction in side activities (cellulase, beta-glucanase, protease and amylase) and a reduction of dough-stickininess. Arabinoxylan degrading enzymes with well defined endo-acting and exo-acting activities have become commercially available, for food and feed, from the following companies: Amano, Danisco-Cultor, EDC/EB, Genencor, Gist-Brocades-DSM, logen, Novozymes, Primalco, Quest, Rhodia and Rohm. Suggested applications for commercial xylanases (endopentosanases) and hemicellulases (pentosanases) mentioned in the literature include: 1) improving the watering of spent grains and energy reduction during grain drying; 2) facilitation of dough formulation with less water, reduction of stickiness in noodle and pasta production; 3) reduction in the water content when formulating grains for flaking, puffing or extrusion; 4) retarding staling or hardening in bread; 5) relaxing dough for cookie and cracker production and use of sticky cereal flours in new product formulations; 6) increase in bran removal when added to tempering water; and 7) reducing both steeping time and starchy fiber in corn wet milling.
A complex set of conditions determines bakery product shelf life, so the food formulator has three basic approaches to crumb softness: prevent moisture transfer; prevent starch recrystallization; and hydrolyze starch. Crumb staling is marked by many physicochemical changes which occur in the following order: hardening and toughening of the crumb (starch retrogradation); appearance of crumbliness; and moisture loss by evaporation. Commercial amylases act as anti-staling agents by breaking down gelatinized starch during baking. Some commercial microbial amylases (ETA, 1999;FDA, 1998) are listed by name and source are: a) endo-amylase ( A. oryzae/niger , and R. oryzae/niveus : EC 3.2.1.1); b) exo-glucoamylase/exo-amyloglucosidase ( R. oryzaelniveus and Aspergillus oryzae/niger : EC 3.2.1.3); and c) endo-pullulanase and endo-amylase ( B. subtilis, B. megaterium, B. stearothermophilus and Bacillus spp.: EC 3.2.1.33,41/60 and EC 3.2.1,133). Genetic engineering technology has been used to develop amylases with endo or exo-acting (maltogenic) activity with intermediate thermostability (<65° C.) and B. stearothermophilus falls into this category. These novel amylases are fully inactivated during baking while yielding a soft crumb without gumminess even at higher dosages. Lopez-Mungia et al. (MX Patent 952,200) described an enzymatic process (with endoamylases) to obtain corn tortillas (from nixtamal or nixtamalized corn flour), which delays staling during frozen storage. Furthermore, the commercial enzyme products normally contain one or more enzymatic activities such as: carbohydrase (amylase, xylanase), protease and esterase. These hydrolases are enzymes catalyzing the hydrolysis of various bonds: EC 3.2 Glycosylase is a carbohydrase acting on O-glycosyl bonds (EC 3.2.1) and EC 3.4 Peptidase is a protease acting on peptide bonds. The proteases are further divided into “exopeptidases” acting only near a terminus of a polypeptide chain (aminoacid polymer/protein) and “endopeptidases” acting internally in polypeptide chains. The usage of “peptidase” is synonymous with “protease” as it was originally used. Two sets of sub-classes are recognized, those of the endoproteases (EC 3.4.21-24/99) and those of the exoproteases (EC 3.4.11-19). The endoproteases are mainly divided on the basis of catalytic mechanism and specificity: Serine proteases (EC 3.4.21 acting at alkaline-pH), Cysteine/Metallo proteases (EC 3.4.22/24 acting at neutral-pH) and Aspartic proteases (EC 3.4.23 acting at acid-pH). Microbial proteases fall into three broad groups: a) acid proteases with maximal activity between pH 2 and 4, b) neutral proteases at pH 7-8, inhibited by metal-chelating agents and c) alkaline proteases at pH 9-11, cleaving a wide range of peptide and ester bonds as well. Bacillus endoproteases can be divided in two types: A-group ( B. subtilis, B. licheniformis/B. pumilus: < 50° C.) does not produce neutral protease or amylase, and B-group ( B. subtilis NRRLB3411, B. amyloliquefaciens and B. subtilis var. amylosacchariticus ) produces a neutral ( B. megaterium/stearothermophilus: ˜ 70° C.) and endo/exoamylase as well (Keay et al., 1970a,b).
A moderate hemicellulase addition decreases water uptake in wheat dough, whereas using a xylanase increases water binding and soluble-xylans as well for a high-moisture bread product. On the contrary, if starch gelatinization is to be minimized, a higher endoenzyme or xylanase addition is desirable and hydrolysis of the soluble fraction releases water for low-moisture cookie or cracker products (EPA Patent 0/338787). Therefore, a suitable level of xylanase results in desirable dough softening without causing stickiness, thereby improving machinability during forming and baking operations. Haarasilta et al. (U.S. Pat. No. 4,990,343) and Tanaka et al. (U.S. Pat. No. 5,698,245) have proposed that a preparation of hemicellulase or pentosanase with a cellulase (Cultor/Amano) causes decomposition of wheat insoluble fiber for bread volume increase. Rubio et al. (U.S. Pat. No. 6,764,699) have improved the flexibility and elasticity of packaged corn tortillas after 7 days of ambient storage by adding a fungal mix of xylanase and cellulase (>100 ppm) to a whole nixtamalized corn flour.
Antrim et al. (CA Patent 2,015,149) disclosed a process of preparing a shredded, farinaceous product by cooking whole grain (wheat), treating it with a microbial isoamylase, tempering (i.e., holding) and forming in order to bake or toast the shredded wheat product. Tobey et al. (U.S. Pat. No. 5,662,901) have used an enzyme formula (>200 ppm) and conditioned the wet or soaked grain (sorghum) for at least 30 minutes. The microbial enzymes comprised a hemicellulase, an amylase, a pectinase, a cellulase and a protease to increase both animal weight gain and feed use efficiency. Van Der Wouw et al. (U.S. Pat. No. 6,066,356) also reported the use of a recombinant-DNA endo-arabinoxylanase (Gist Brocades) breaks down the water-insoluble-solids (˜1.5%) from degermed maize and increases their in-vitro digestion (13%-19%) for animal feed or in wheat flour for improving its bread volume (˜9%).
A pilot process (WO Patent 00/45647) for the preparation of a modified masa foodstuff used a reducing agent (metabisulfite) or an enzyme as a processing aid (disulfide isomerase or thiol-protease/Danisco) with masa or corn prior to nixtamalization such that the native protein is modified. Jackson et al. (U.S. Pat. No. 6,428,828) disclosed a similar process where whole-kernel corn was steeped and digested with a food-grade commercial alkaline-protease (<1000 ppm: 50° C.-60° C.; pH>9) which altered zein structure similarly to alkali-cooking with a partial gelatinization (˜20%-40%).
A novel transgenic thermostable-reductase enzyme was cloned in corn (high-protein) mainly to enhance extractability and recovery of starch and protein important in flaking grit production and in masa production. Reduction of protein disulphide bonds alters the nature of corn flour (as a wheat substitute from high-protein corn) when steeping the corn grain between 45° C. and 95° C. instead of using sulfite salts. The critical steeping is required to soften the kernel and then to loosen starch granules from the complicated matrix of proteins and cell wall material that makes up the corn endosperm (WO. Patent 01/98509).
Tortilla is the main edible corn product in North and Central America. It is a flat, round, unleavened and baked thin pancake (flat-cornbread) made from fresh masa (ground nixtamal) or corn dough prepared from nixtamalized corn flour (masa flour). It might be mentioned that tortilla, when manually or mechanically elaborated and without additives of any kind, has a maximum shelf life of 12 to 15 hours at room temperature. Afterwards they are fermented or spoiled by microorganisms and becoming hard/stale (starch-protein aggregation) due to a physicochemical change in the starch constituent of either stored or reheated tortilla. It is known that tortillas when kept under conditions in which no moisture is lost (plastic package), nevertheless become inflexible with time and break or crumble easily when bent. In northern South America, particularly in Colombia and Venezuela, hard endosperm corn is processed with dry milling technology without wastewater and it is further converted into a precooked, degermed and debranned flour for traditional foods. Its consumption is mainly in the form of “arepa”, which is a flat or ovoid-shaped, unleavened, and baked thick-pancake made from instant flour. In other South American countries, corn meal (polenta) and corn flour as well are used for empanada, pancake and snack food (FAO, 1993).
Food fermentation processes are reliant on both endogenous and microbial enzymatic activities for the degradation of fibers, starches, proteins, anti-nutritional and toxic factors. In some cases, microbial processes are associated with indigenous fermentation processes, which exhibit unique properties. Microorganisms are currently the primary source of industrial enzymes: 50% are derived from fungi and yeast; 35% from bacteria, while the remaining 15% are either of plant or animal origin. Microbial enzymes are commercially produced either through submerged fermentation or solid-substrate fermentation technologies. The use of biocatalysts or enzymes has the potential to increase productivity,-efficiency and quality output in agro-industrial processing operations in many emerging countries. These biochemical processes generally have requirements for a simple manufacturing base, low capital investment and lower energy consumption than other food processing unit operations. Alkaline and neutral-pH fermentations of various beans (soy and locust), seeds, and leaves provide protein/lipid rich, flavorsome, low-cost food condiments to millions of people mainly in Africa and Asia (Nigerian dawadawa/ogiri, Sierra Leone ogiri-saro, Japanese natto, Indian kenima, Indonesian cabuk/semayi). Based upon the use of Bacillus spp. ( B. subtilis B. licheniformis, B. pumilus ), the fermentations are primarily proteolytic, yielding amino acid/peptide-rich mixtures without microbial amylase and lipase activities mainly in seeds (Steinkraus, 1996). Pozol is a fermented corn doughball (from nixtamal or lime-treated maize) produced and consumed, as a beverage/porridge, by the indigenous and mestizo population in S.E. Mexico. It is a probiotic fermentation involving at least five interacting groups which include the natural flora from a freshly prepared dough or nixtamalized corn flour (heat-resistant Bacillus spp. and Actinomycetes spp.). Agrobacterium azotophilum (reclassified as Bacillus subtilis : NRRL B21974) and K pneumonia ( E. aerogenes ), both of which grow in nitrogen-free media and increase the aminoacid nitrogen and likely the total-nitrogen during this solid-substrate fermentation. The other groups include a lactic-acid bacterium (amylolytic Lactobacillus sp.), which increases its flavor (0.7% lactic-acid) while lowering the alkaline pH (from 8 to ˜5 at 24-48 hours); C. tropicalis which contributes to an alcoholic/fruity aroma, and G. candidum which produces aroma and spongy texture (Ramirez and Steinkraus, 1986; Steinkraus, 2004). On the other hand, a corn wet-milling process for starch production involves an acid (pH<5) fermentation during steeping or soaking whole corn kernels counter-currently (24-48 hours at 45-50° C.). The purpose is to soften the endosperm and to break the disulfide-bonds holding the protein matrix together. Steeping is a diffusion limited unit operation where two steep-water chemical and biochemical aids are required (with ˜0.10-0.25% sulfur dioxide and ˜0.5-2.0% lactic-acid usually produced by Lactobacillus spp.). They can diffuse into the corn kernel through the base end of the tip cap, move through the cross and tube cells of the pericarp to the kernel crown and into the endosperm (Watson, 1987). The main result of a lactic fermentation is a dispersion of endosperm protein/zein and an enhancement of starch release during subsequent milling for acid-fermented corn gruels/porridges such as: Ghanian kenkey, Nigerian ogi (industrial), Kenyan uji and South African mahewu (Steinkraus, 1996 and 2004).
Properly processed industrial corn or masa flour simplifies the production of tortilla and snack products, because the customer eliminates management techniques required for wastewater treatment, securing, handling and processing corn into fresh masa for tortillas and snacks. However, an instant corn flour might have the following quality and cost disadvantages: high cost, lack of flavor and poor texture in masa and third-generation (3G) corn foods. These may include extrusion cooking, followed by cooling, holding (aging) and drying to make “snack pellets” which are expanded by frying to make the final snack product. Another example is breakfast cereals made by cooking whole grain (wheat, rice, or corn), followed by cooling, tempering (conditioning), shredding, forming into “biscuits” and baking.
Corn processors can generate added value from their industrial operations in one of three approaches: developing new products from new hybrids, increasing the yield of traditional products from corn, and improving process efficiency at a lower unit cost. In the past, this has been done by methods and using an apparatus in which the grain is cooked and/or steeped in a lime-water solution such as those disclosed in U.S. Pat. Nos. 2,584,893, 2,704,257, 3,194,664, and 4,513,018. These prior art methods for the industrial production of corn dough or masa flour involve accelerated cooking and steeping times with large amounts of solids losses (˜1.5-2.5%) in the liquid waste. In addition, essential nutrients such as vitamins and some amino acids are lost, depending on the severity of the cooking, washing and drying operations.
Many and varied methods for the production of instant corn flour for food products involving reduced amounts of water with low-temperature cooking and short-time processing for a high yield of the end product have been developed, as reflected by the following U.S. Pat. Nos. 4,594,260, 5,176,931, 5,532,013, and 6,387,437. In this connection, reference is made to the following U.S. Pat. Nos. 4,594,260, 5,176,931, 5,532,013, and 6,265,013 also requiring a low-temperature drying. On the contrary, U.S. Pat. Nos. 4,513,018, 5,447,742 5,558,898, 6,068,873, 6,322,836, 6,344,228 and 6,516,710 used a high-temperature dehydration or cooking in place of a low-temperature cooking.
Having in mind the disadvantages of the prior art methods, several studies not only have used a low-temperature precooking with minimum wastewater, but also separate corn fractions as reflected by the following U.S. Pat. Nos. 4,594,260, 5,532,013, 6,025,011, 6,068,873, 6,265,013, 6,326,045 and 6,516,710.
A few applications for enzymatic steeping were also tested to convert a traditional masa processing with reduced wastewater into a novel biochemical process (WO Patent 00/45647 and U.S. Pat. No. 6,428,828). Although the above described prior art methods are capable of either an acid or an alkaline-enzymatic precooking or steeping of the whole corn for either modified masa or masa flour processing, a continuous industrial application using instead a blend of xylanase, an endoamylase and an endoprotease as a processing aid, at a neutral-pH, was still unavailable in the market at the time of the invention.
SUMMARY AND OBJECTS OF THE INVENTION
Accordingly, it is an object of this invention to provide a complete departure from the prior art accelerated precooking methods of thermal, mechanical, chemical and enzymatic or bioprocessing of whole corn in order to control not only a starchy endosperm gelatinization but also protein denaturation without using chemicals during production of an instant corn flour for snack and tortilla foods.
It is another object of this invention to use low-temperature cooking with a microbial xylanase, endoamylase and endoprotease solution for a partial hydrolysis of bran heteroxylans, starchy and proteinaceous cell-walls during the continuous production of precooked corn flour. A combined use of a commercial xylanase, endoamylase and endoprotease is preferred.
Another object is to use an industrial method and apparatus involving a low-temperature, neutral-pH precooking which not only solubilize corn cell-walls along with a slower water diffusion effecting a controlled starch granule swelling, but also results in a reduced corn solid loss.
The above and other objects and advantages of the invention are achieved by a new continuous process applied to the production of precooked corn flour or instant corn flour for snack and tortilla, embodiments of which include a short-time corn precooking followed by a low-temperature and neutral-pH precooking with a xylanase, endoamylase and endoprotease as a processing aid so as to effect a partial hydrolysis of insoluble bran layers with decreased gelatinization and denaturation, reduced washing and corn solid loss of precooked kernel, stabilization of the moisture content to a desired optimum level for milling and drying the preconditioned kernel to produce a uniform partial gelatinization, cooling and drying the dry-ground particle, separating and recovering the fine grind so produced from the coarser grind while the latter is further aspirated to remove a partially hydrolysed bran fraction for integral flour or animal feed diet, remilling the isolated coarser grind and further sieving it to obtain an instant corn flour for snack, and admixing only a fine flour with lime to produce masa flour for tortilla and derivatives thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood from the description, which follows, and from the appended drawing in which the sole drawing FIGURE depicts an embodiment of this invention in a block-type flowchart illustrating the continuous and industrial bioprocess using a low-temperature and neutral-pH precooking with a xylanase, endoamylase and endoprotease solution as a processing aid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1 , there is depicted, in flowchart form, an embodiment of the present invention. It includes a pre-cooker 1 ; a washer 2 ; a preconditioner 3 with a feeder; a primary mill 4 ; a furnace 5 ; a dryer 6 with a fan; a first cyclone separator 7 ; a cooler 8 with an associated fan; a second cyclone separator 9 ; a sifter 10 ; an aspirator system 11 ; and a secondary mill 12 .
The pre-cooker 1 , whose design is known per se, is fed with cleaned corn and a steam-heated steepwater (70° C. to 85° C.) recycled from the washer 2 to form an aqueous suspension (corn to water ratio of about 1:1 to 1:2.0). The corn kernel is parboiled in order to loosen their bran cell walls and partially hydrated from a range of 9%-12% to a range of about 24%-32% for a period of about 20 to about 40 minutes. Next, a microbial xylanase, endoamylase and endoprotease solution is continuously added as a food processing aid into the pre-cooker at a low-temperature range of about 50° C. to 70° C. for another period of 10 to 75 minutes. This allows the enzymatically precooked kernel to be produced at moisture contents of between 32% and 37%, while the pH is maintained at a neutral-pH of about 6.0 to about 8.0 with the addition of a 10% solution of xylanase, endoamylase and endoprotease. The solution is provided in an amount representing 0.025% to 0.25% of the corn kernel (by weight). Preferably, the solution is provided in an amount representing 0.025% to 0.180% of the corn kernel (by weight). By controlling the steam heating along with the kernel residence time, it is possible to partially precook the corn at a temperature of about 50° C. to 85° C. for a total period of 30 to about 115 minutes in order to soften their bran layers. The neutral-pH precooking may be performed so that it is only the mixture of corn kernel, the steepwater, and the microbial solution that are subjected to precooking. It is possible that the microbial solution may include only a carrier and one or more of xylanase, endoamylase and endoprotease.
Wastewater loss in the precooker is replaced with recycled steam-heated steepwater from the washer 2 , which is regulated to maintain the solid content of the solution from about 1.0% to about 1.5%. The industrial pre-cooker performs a partial hydrolysis of corn bran and starchy/proteinaceous cell-walls that promotes a fast water diffusion through the pericarp and tip cap layers, and later on a slow penetration via the endosperm and germ cell-walls increasing starch granule swelling. This low-temperature precooking (<70° C.) further controls both insoluble fiber and starch/protein solubilization as well (from about 0.5% to about 1.5% water-extractable solids, based on corn kernel), thus permitting at least a 35% reduction in soluble solids concentration as compared to the traditional batch and continuous alkali cooking (1.5-3.0%: U.S. Pat. Nos. 6,516,710 and 4,513,018). The partially precooked corn suspension is then passed to a washer 2 where it is sprayed with hot water at a temperature of about 75° to 90° C. during 30 to 60 seconds, which also serves to increase water absorption and wash off corn solids with denatured endoenzymes as wastewater.
The washed corn is thereafter passed to a preconditioner 3 , where the neutral precooked kernel is equilibrated at 55° C. to about 75° C. to obtain a residual moisture content of about 34% to about 39% for about 15 to about 60 minutes.
Thereafter, the preconditioned corn is fed through a feeder, whose design is known per se, to a primary mill 4 such that the premilled corn and hot air coming from a furnace 5 , is mixed and partially cooked by an industrial dryer 6 whose design is known per se. The premilled kernel is thereby flash dried at a high-temperature from 190° C. to about 230° C. for a short time of 5 sec to about 30 sec. Its starchy endosperm is partially gelatinized or precooked to yield a moisture content of 16% to about 20% at 60° C. to 75° C. depending on the granulation being produced.
Moisture laden-hot air (110° C. to 120° C., and 11% to 13% moisture) is extracted with a first cyclone separator 7 so that further moisture extraction may take place by impelling the drier material through a cooler 8 with an associated fan, thus further decreasing the moisture content from 16-20% to about 9-12% (similar to incoming corn).
After further extraction of moisture laden-warm air (95° C. to 100° C.) with a second cyclone separator 9 , the precooked dry particle is directed to a sifter 10 where the fine fraction is separated (under 20 to 100 mesh) as instant corn flour and the coarser fraction is further separated.
The latter coarse fraction is further separated in the aspirator system 11 wherein two fractions are obtained, a light-bran fraction which is isolated as feed or for integral flour with a moisture content between 9% to 12% (representing from about 3% to about 6% of the total weight of incoming cleaned corn), and a heavy coarser fraction that is remilled in a secondary mill 12 . The milled product from secondary mill 12 is recycled to the sifter 10 for further sieving and producing a homogeneous corn flour for snack. If desired, the instant corn flour can be admixed with lime (from 0.05% to about 0.25% based on precooked flour) to produce a masa flour for making tortilla or corn-based foods.
For use in snack manufacture, the instant corn flour is preferably rehydrated by mixing with warm water from a 1:0.8 to about 1:1.0 weight ratio to form a corn dough (45% to 50% final moisture) for snack elaboration (from about 15% to about 30% total oil).
For use in tortilla manufacture, the masa flour made from the present method can be rehydrated with water from a 1:1.1 to about 1:1.3 weight ratio for a masa dough (50% to 60% final moisture) used in tortilla and corn-based foods (from 45% to 50% moisture).
In this method, the novel neutral enzymatic precooking results in a 35% to 40% reduction in wastewater corn solids, with correspondingly lower sewage and energy costs, as compared to the industrial methods (1.5%-3.0%). Furthermore, the enzymatic precooking of the invention allows a 50% reduction in lime use if an instant masa flour were produced to improve new flavors in corn-based foods as third-generation snacks. The low-temperature precooking (50° C.-70° C.) at neutral-pH (6-8) using a xylanase, endoamylase and endoprotease solution (0.025%-0.25%) not only aids in depolymerization of the insoluble cell-wall biopolymers but also improves its bran removal and recovering its aleurone layer as flour. The endoenzymes partially hydrolyse the pericarp, aleurone and starchy cell-walls effecting a simultaneous water diffusion with a reduced gelatinization and denaturation without using a low-lime (U.S. Pat. Nos. 6,516,710, 6,428,828, 6,387,437 and 6,344,228) or a low-sulfite addition (U.S. Pat. No. 6,322,836).
There is furthermore a potential in corn flour yield from 94% to 97% of the total weight of enzymatically pre-cooked corn as compared to the commercial alkali-cooking process, which yields 88%. Whereas the instant corn flour produced by the novel method may thus comprise a higher than 95% average yield of flour per kilogram of corn, the debranned and degermed flour produced by a typical arepa process obtains only a 65% to 70% yield, or a 80% to 85% yield for an integral arepa flour (U.S. Pat. No. 6,326,045).
Still further, the low-temperature and enzymatically precooked corn flour produced by the present method has a higher nutritional value as compared to the conventional methods, with more dietary fiber and fat contents than the commercial corn flours (INCAP, 1961, Cuevas et al., 1985 and FAO, 1993). Epidemiological studies have shown that regular consumption of fruits, vegetables and whole grains is associated with reduced risk of chronic diseases such as cancer, coronary heart disease and diabetes. Obesity leads to heart disease and cancer. Approximately 35% of deaths due to cancer in the United States are related to diet. The USDA has recommended eating 3-5 servings/day (>5.1 g-fiber) of whole grains (wheat, rice and corn) which comprise the base of the food guide pyramid. An AACC— food health claim is based on a 51% whole grain by weight of a finished product (as integral flour or a nixtamalized corn flour with 7-9% total fiber: U.S. Pat. No. 6,764,699).
From the foregoing, it will be apparent that it is possible to manufacture a precooked and partially-debranned corn flour for snack and masa flour with a novel enzymatic process which is efficient because of partial hydrolysis of cell-walls or solubilization of the endosperm periphery with starch pregelatinization and protein denaturation in the precooked corn kernel, wherein some of the nutrient losses that would have been present but for the features of this invention is prevented.
It is to be understood that the embodiments of this invention herein illustrated and described in detail, are by way of illustration and not of limitation. Other changes and modifications are possible and will present themselves to those skilled in the prior art and by the spirit of the appended claims.
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Precooked and partially-debranned corn flour is continuously produced by an enzymatic precooking using a commercial blend of xylanase, endoamylase and endoprotease as a processing aid. The low-temperature and neutral-pH precooking with an endoenzyme solution effected a partial bran hydrolysis while avoiding excessive pregelatinization, reduced washing and corn solid loss in wastewater. Moisture content is then stabilized, followed by milling and drying at a high-temperature and short-time to produce a controlled gelatinization and denaturation in the ground kernel, cooling and further drying the dried-ground particle. A fine particle size or flour is separated and recovered from the coarser particle which is also segregated to isolate a partially hydrolysed bran fraction for integral flour or animal feed diet, remilling and sieving the coarser particle to produce an instant corn flour for snack, and admixing the fine particle with lime to obtain a masa flour for tortilla and other corn foods.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to image processing technology to be employed with so-called 3D game devices and action puzzle games, and particularly relates to the improvement in image processing devices for displaying realistic scenes of structures such as buildings being destroyed.
2. Description of the Related Art
A typical 3D game device is capable of displaying numerous objects (an aggregate of bitmaps displayed on the screen; hereinafter referred to as “object”) arranged in a three-dimensional virtual apace. Buildings and game characters (hereinafter referred to as “character”), for example, are displayed as objects, and by changing the display position of these objects in vertical synchronization units, a moving image simulating battle scenes in the city can be displayed.
Conventionally, as a building object had the likes of a simple cube shape, texture mapping was performed by applying a single polygon to each of the walls of such building. When the building object and another object (bullet, character, etc.) collide, images suggestive of an explosion such as a flash, flame, and smoke are displayed at the collision point. With respect to the display of the building object after the collision, the same image prior to the collision without making any changes to the building itself is displayed, or a previously prepared image of the building object after the collapse is displayed.
Moreover, restrictions were sometimes added to the range is which the “character”) is able to move. This was in order to prevent the display of arena is which buildings were not established when a character approaches an area where the building object was established. For example, by displaying walls of buildings or rivers, or by making the operation impossible, characters could not proceed any further.
One purpose of a game, however, is to have the player experience an invigorating feeling, and it is important to realistically express pictures of the collapse or explosion of objects. In a game share a monster is rampaging in a city, for example, an important factor in determining the value of a game is how the monster destroys the buildings. In other words, it is preferable that the buildings is destroyed realistically as though watching a scene from a monster movie. If no change is made to the building or the destroyed condition of such building is suddenly displayed as in conventional game devices, the resulting image becomes dull and unattractive.
In this type of game, there are also demands of producing a gruesome feeling in which a monster destroys buildings one after another. The distinctive feature is that the monster wrecks any and all buildings in its path. Therefore, the amusement is diminished when adding restrictions to the operation for the range in which the character, i.e., the monster may move as in conventional game devices.
Further, when this type of monster object is attacked, it is preferable to reflect the degree of damage to the monster's posture and to display an image as though a living creature is actually injured.
In view of the foregoing problems, the inventors of the present invention have arrived at this invention with as object of displaying images, as though a monster movie, in a realistic manner.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide image processing technology capable of destroying objects such as buildings in a realistic manner.
Another object of the present invention is to provide image processing technology capable of naturally restricting the range in which the character may move.
Still another object of the present invention is to provide image processing technology capable of expressing the degree of damage to the character in a realistic manner.
The present invention is an image processing device for displaying a moving image of an object collapsing, wherein the image processing device sets in advance each of the display blocks to be scattered after the collapse as collective movable display elements, structures an object with the display elements, and displays such object. Here, “object” shall include displayed images such as models, characters and segments, still life such as buildings and landforms, and living/nonliving objects with motion such as fighter planes, monsters, people, robots and cars. “Collapse” shall mean the transition of a single object into a plurality of parts or a smaller shape, and includes situations of simulating physical phenomenon such as collisions in the virtual space as well as changing the form by oneself with settings ouch as earthquakes and suicidal explosions. “Scattering” shall include situations of each of the display elements being separated from each other, as well as situations where a plurality of display elements move without separating, and detach from other display elements. A group of display elements that separate collectively can be further collapsed. The display elements, for example, are set to shapes simulating block clods created upon an actual collapse of a building.
When each of the display elements approaches a specific object within a predetermined distance, such display element may be erased. “(Approach) within a predetermined distance” is a concept including contact. When a certain display element is erased, an image of a display element positioned directly thereabove falling at a prescribed speed may be displayed. Here, “directly thereabove” and “falling” are definitions of directions along the virtual gravitational direction set forth in the virtual space for reasons of convenience.
When a certain display element is erased, an image of a display element adjacent thereto moving at a speed in accordance with the intensity of the impact inflicted upon the object may be displayed. Here, “impact” shall mean the virtual external force inflicted upon the object or display element for reasons of convenience, and is specified by defining the strength and direction of the external force.
When a certain display element is erased, an image of a display element adjacent thereto moving in a direction in accordance with the direction of the impact inflicted upon the object may be displayed. Here, “adjacent” shall include cases where a display element is in contact with a side of one part of a display element as well as being within a prescribed distance from the side or center of gravity of a display element.
When a certain display element is erased, an image of a display element adjacent thereto rotating at a rotation speed in accordance with the size of the display element may be displayed. Here, “rotation” shall mean rotating around the rotation axis defined within the virtual space appropriately set forth in the display element.
When the intensity of the impact inflicted upon the object exceeds a prescribed value, the display position of the image of the display element adjacent to the erased display element map be changed. In addition, whey a certain display element is erased and therefore the remaining display elements are arranged in a horizontal row and supporting the object in a virtual space, and when the number of supporting display elements are less than a prescribed number, an image of these display elements and/or the display elements supported thereby falling at a prescribed speed may be displayed. Here, display elements “supporting the object” shall mean those display elements structuring the neck portion of a constriction part of a display element, which has changed in comparison to the original shape, upon a part of the object collapsing.
When another impact is to be inflicted upon a part of the object remaining without being erased during or after the fall, a display element structuring a part of the object may be farther erased, moved, or rotated. In other words, additional second and third attacks may be made to the blocks that have collapsed after the first attack. When the display element structuring the object is separated with the whole or part thereof remaining upon the infliction of an impact, these display elements are erased. That is, the display elements are erased after being determined that the display elements have separated.
The present invention is an image processing device capable of displaying a movable character within a virtual space, wherein when the character goes out of the area set in the virtual apace, the image processing device displays a uniformly changing image of the degree of brightness and/or color of the picture element displaying the character. Here, it is preferable that the degree of brightness and/or color of the picture element be changed in accordance with the distance between the character and the boundary of the area. It is further preferable that it is structured to be capable of performing completion processing when the time in which the character is out of the area reaches a prescribed time.
The present invention is an image processing device capable of displaying a movable character in a virtual space, wherein when it is determined that a character collided with another object, the image processing device displays an image of a change in the character's posture until a prescribed condition is fulfilled. Hare, it is preferable that the character's posture be a posture protecting the point of collision. Here, a prescribed condition is the character making a predetermined motion, and a prescribed condition is the lapse of the predetermined time.
The present invention is an image processing method for displaying a moving image of an object collapsing, wherein the image processing method sets in advance each of the display blocks to be scattered after the collapse as collective movable display elements, structures an object with the display elements, and displays such object.
The present invention is an image processing method capable of displaying a movable character within a virtual space comprising the steps of determining whether or not the character has gone out of the area set in the virtual space, cad displaying as image of the degree of brightness and/or color of the picture element displaying the character being changed uniformly when the character goes out of the area set in the virtual space.
The present invention is an image processing method capable of displaying a movable character within a virtual space comprising the steps of determining whether or not the character collided with another object, determining whether or not a prescribed condition has been fulfilled when it is determined that the character has collided with another object, and displaying an image of a change in the character's posture when the condition is not fulfilled.
The present invention is a machine-readable recording medium storing a program for making a computer execute the aforementioned image processing method. Here, “recording medium” shall mean any physical means storing information (mainly digital data, programs) and capable of making processing devices such as computers and dedicated processors perform prescribed functions. In other words, any means capable of downloading a program to the computer and making it perform prescribed functions will suffice. Examples of such medium include flexible disc, secured disc, magnetic tape, optical magnetic disc, CD, CD-ROM, CD-R, DVD-RAM, DVD-ROM, DVD-R, PD, MD, DCC, ROM cartridge, RAM memory cartridge with battery backup, flash memory cartridge, non-volatile RAM cartridge, and so on. This includes asses when receiving data transmission from a host computer via a wire- or wireless-communication circuit (public circuits, data dedicated lines, satellite circuits, etc.). The so-called Internet is also included in the recording medium mentioned above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a conceptual diagram of the connection of the game device in the present embodiment;
FIG. 2 is a block diagram of the game device in the present embodiment:
FIG. 3 is a flowchart explaining the method of displaying buildings in the present embodiment;
FIG. 4 is a flowchart explaining the area-out processing in the present embodiments;
FIG. 5 is a flowchart explaining the damage processing in the present embodiment;
FIG. 6 is a conceptual diagram of the display of the building object in the present embodiment;
FIG. 7 is a conceptual diagram of the display upon the collision of a building object:
FIG. 8 is a first conceptual diagram of the display upon the collapse of the building object;
FIG. 9 is a second conceptual diagram of the display upon the collapse of the building object;
FIG. 10 is a third conceptual diagram of the display upon the collapse of the building object;
FIG. 11 in a conceptual diagram of the display upon completion of the collapse (first collapse) of the building object;
FIG. 12 is a conceptual diagram of the display upon a second attack on the building abject;
FIG. 13 is a conceptual diagram of the display during the collapse after the second attack on the building object;
FIG. 14 is a conceptual diagram of the display upon completion of the second attack on the building object;
FIG. 15 is a first example of the actual display of an image in the present embodiment;
FIG. 16 is a second example of the actual display of an image in the present embodiment;
FIG. 17 is a diagram of the position relationship explaining the area-out processing of a character;
FIG. 18 is a conceptual diagram of the display of the area-out processing;
FIG. 19 is a conceptual diagram of the display of the character at the moment it is damaged;
FIG. 20 is a conceptual diagram of the display of the character while it is sustaining damage; and
FIG. 21 is a display example of the evaluation image in the present embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention is hereinafter described with reference to the relevant drawings.
(Structure)
FIG. 1 is a conceptual diagram of the connection of a game device employing the image processing device in the present embodiment. This game device is structured by mutually connecting a game device body 1 and a controller 2 .
The game device body 1 is the main controlling device for managing the game progress. The game device body 1 is capable of connecting a plurality of controllers 2 , and thereby comprises a plurality of connectors 141 and a modular jack 131 for a communication circuit. The game device body 1 further comprises a CD-ROM holder 105 and is capable of freely installing/removing a recording medium such as a CD-ROM. The controller 2 is structured as an operation portion for each of the players to operate, and comprises an operation button group 22 , a cross-shaped key 23 , and a connector for connection with the game device body 1 . The controller 2 further comprises a slot for freely installing/removing a sub-unit 21 . The sub-unit 21 is for displaying a sub-image display and for a player to play a sub-game, and comprises a sub-monitor 211 , an operation button group 212 , end a connector for connection to the slot of the controller 2 . A connection cable 150 comprises connectors 151 and 152 , and in capable of mutually connecting the game device main body 1 and the controller 2 . The video signal output and audio signal output of the game device bode are, for example, output to a TV device.
FIG. 2 shows a block diagram of the present game device. The game device body 1 , as shown in FIG. 2, comprises a CPU block 10 , a video black 11 , a sound block 12 and so on.
The CPU block 10 comprises a bus arbiter 100 , CPU 101 , main memory 102 , ROM 103 and CD-ROM drive 104 . The bus arbiter 100 is capable of controlling data transmission/reception by assigning a bus-occupancy time to the mutually connected devices via a bus. The CPU 101 is capable of accessing the main memory 102 , ROM 103 , CD-ROM drive 104 , video block 11 , sound block 12 and, via the controller 2 , sub-unit 21 . The CPU 201 implements the initial program stored in the ROM 103 upon the power source being turned on and performs initialization of the entire device, When the CPU 101 detects that a CD-ROM has been installed into the CD-ROM drive 104 , it transfers the program data for the operating system stored in the CD-ROM to the main memory 102 . Thereafter, the CPU 101 operates is accordance with the operating system and continues transferring the program of the image processing method of the present invention stored in the CD-ROM to the main memory 102 and implements such program. In addition, the CPU 101 transfers the image data for image processing of the, present invention to a graphics memory 121 , and is capable of transferring audio data to the sound memory 121 . The program processing implemented by the CPU 101 are, for example, input of operation signals from the controller 2 or communication data from a communication device, command output to the sub-unit 21 based on such signals and data, control of the image output to be performed by the video block ii and control of audio output to be performed by the sound block 12 .
The main memory 102 mainly stores program data and programs for the aforementioned operating system and is also capable of providing a work area for storing the likes of static variables and dynamic variables. The ROM 103 is a storage region for an initial program loader. The CD-ROM drive 104 is structured such that a CD-ROM is freely installable/removable, outputs data to the CPU 141 notifying the installation of a CD-ROM, and is capable of data transfer by the control of the CPU 101 . The CD-ROM stores a program for making the game device implement the image processing method of the present invention, image data for displaying images, dad audio data for audio output. The recording medium in not limited to a CD-ROM, and may be other various recording mediums structured to be readable. The data group stored in the CD-ROM may be transferred to each memory via the communication device 130 . By this, data transfer from a secure disc of a distant server is possible.
The video block 11 comprises a VDP (Video Display Processor) 110 , graphic memory 111 , and video encoder 112 . The graphics memory 111 comprises a storage region of image data read from the CD-ROM and a frame memory region. In the image data storage region, stored collectively in object units is polygon data for prescribing each of the vertex coordinates of polygons for displaying an object in a virtual space. The present invention is characterized in the special setting to the polygon data for displaying buildings as objects, which will be explained in detail later. The VDP 110 refers to a portion of the image data stored in the graphite memory 111 based on the control of the CPU 101 , generates bitmap data, and stores this in the frame memory region. As information necessary for displaying images supplied from the CPU 101 , there is command data, viewpoint position data, light source position data, polygon designation data, object designation data, polygon position data, polygon method data, texture designation data, texture density data, visual field conversion matrix data, and so on. Based on this information, the VDP 110 is capable of implementing coordinate conversion (geometry operation) to polygons, texture mapping processing, display priority processing, shooting processing, and the like. The video encoder 112 converts the image data generated by the VDP 110 to a prescribed video signal such as an NTSC format, and outputs this to the main monitor 113 of the TV device connected externally.
The sound block 12 comprises a sound processor 120 , sound memory 121 , and D/A converter 122 . Stored in the sound memory 121 is audio data read from a CD-ROM as mentioned above. The sound processor 120 , based on command data supplied from the CPU 101 , reads audio data such as waveform data stored in the sound memory 121 sad performs various effects processing pursuant to the DSP (Digital Signal Processor) function and digital/analog conversion processing. The D/A converter 122 converts the audio data generated by the sound processor 120 into analog signals and outputs these to the speakers 123 of the TV device connected externally.
The communication device 130 is, for example, a modem or a terminal adapter, and functions as an adapter that connects the game device body 1 and external circuits. The communication device 130 receives data transmitted from a game-supplying server connected to a public circuit network, and supplies this to the bus of the CPU block 10 . The public circuit network includes, but is not limited to, a subscriber circuit and dedicated line, regardless of it being a wire system or a wireless system.
The controller 2 periodically converts the operation situation of the operation button group 22 and cross-shaped key 23 into codes and transmits these codes to the game device body 1 . The operation signals from each of these controllers 2 are used to move the respective characters displayed in the game. The sub-unit 21 is structured as a computer device comprising an independent CPU and memory so as to be able to operate as independent game, end stores setting data including settings each as the game progress, game scores and operation methods arising during a game. Setting data transmitted from the game device body specifying the game processing situation may be stores in the sub-unit 21 . This setting data is transferred to the game device body as backup data for restarting the game from the condition prior to shutting down the power source when the power source is to be shut down. By exchanging the sub-unit, such exchanged sub-unit becomes the data reflecting the operation situation of another game device in the game devise concerned.
(Operation)
Next, the operation of the game device is explained. In this game, a moving monster is displayed as a character. When the monster's body collides with a building, which is a structural object, a part or whole of the building collapses. The player operates the movement of the monster and destroys the buildings one after another by making the monster's tail, head or body hit the building and by firing laser beams at the building. The game device evaluates the game by giving scores for the method of destruction.
Collapse Processing
The constitution of the structural object is the present embodiment is foremost explained with reference to FIG. 6 . FIG. 6 ( c ) is a plane view showing the relation of the object and viewpoint arranged in the virtual space. The object OBJ is formed in a shape simulating a building and comprises four walls A, B, C and D. View point VP is a viewpoint of a three-dimensional image for viewing this abject OBJ. FIG. 6 ( a ) is an example of the object OBJ actually being displayed on the monitor 11 . The walls A and B facing the viewpoint side have texture data mapped thereon to give a realistic image of a building. FIG. 6 ( b ) shows is dashed lines the display elements structuring this object OBJ. Wall A is structured of display elements 1 ˜ 13 and wall B is structured of display elements 20 ˜ 29 . Walls C and D, not displayed, are also respectively structured of an aggregate of display elements ( 30 ˜ 39 for Wall C and 40 ˜ 49 for Wall D). In the present embodiment, display elements are treated synonymously as a polygon, which is the minimum display wait. Display elements, however, may also be sat as a group of polygon data structured to be simultaneously movable by a plurality of polygons. In any case, unlike the ordinary simple triangular or quadrilateral polygons, a plurality of vertexes are establishes in order to realize a complex outline. The shape of the display elements is set to be as though a rugged broken surface to simulate block clods created upon the actual collapse of a building. A display of a collapsed building is obtained by merely separating the display elements. These display elements may also be divided into blocks per group of a plurality of adjacent display elements. The display elements divided into blocks are capable of moving without being separated per block The coordinate direction seen from the viewpoint, as coordinate axis X, Y and Z shown in FIG. 6, is set forth below.
The CPU block 10 transfers to the video block 11 object designation data for designating the object OBJ, polygon designation data for designating polygons to be displayed, polygon position data for designating the position of sack polygon in a world-coordinate system, polygon direction data for designating the normal line direction of each polygon, and texture designation data for designating the viewpoint position data of the viewpoint VP and texture data to be mapped onto each polygon. The video block 11 specifies the polygon data group of the object OBJ to be displayed by the polygon designation data, and extracts polygon data to be displayed by the polygon designation data. And pursuant to the viewpoint position data and polygon. Position data, the video block 11 performs perspective conversion on the vertex coordinates of each polygon and performs mapping of texture data onto each polygon. By this as image of an object OBJ is displayed as though viewing an actual building from a specific viewpoint.
When erasing a specific display element upon collapsing a building, the CPU block prohibits the transfer of polygon designation data for specifying the display element to be erased. When dropping a specific display element, the CPU block calculates the direction and rotation speed of the drop based on the intensity and direction of impact inflicted upon such display element. And by changing the polygon position data and polygon direction data of the display element per frame displaying period, the CPU block displays a display element as though it is falling while rotating.
Next, the collapse processing method of the object is explained in detail with reference to the flowchart shown is FIG. 3 . This flowchart is the processing for a single display element or a block including such display element. The same display processing is performed with respect to the other display elements and blocks.
The renewal of frame image data is conducted per frame displaying period. The CPU block 10 awaits this renewal timing (S 101 , NO), and performs collision judgment (S 102 ) when it is the timing of generating a new image (S 101 , YES). Known art is used for this collision judgment. In other words, a collision circle with a prescribed radius is established on each of the display elements of the structural object OBJ and/or the monster. And when the distance between the center of both collision circles come within the sum of the radius of both collision circles, judgment of collision is made. When a collision is confirmed as a result of the collision judgment (S 102 , YES), the CPU block performs erase processing to the display elements that have collided (S 103 ). Erase processing is completed when the CPU block prohibits the transfer of polygon designation data for designating the display elements. Situations of the display elements being erased are, for example, when the monster contacts the display element and when the falling display element lands on the ground. If colliding into a monster (S 104 , Monster), the CPU block generates the collision vector I for deciding the intensity of impact and direction thereof (S 103 ). The collision vector may be set optionally. For example, when the monster's tail or laser beam bits an object, the collision vector may be set in correspondence with the direction of incidence and the moving speed. A single collision vector common with such of the display elements structuring the object is set. In order to realize an atmosphere of an internal explosion of a building, a collision vector directed outward may be set to each of the walls A˜D of the object OBJ irrelevant to the collision of the monster. A separate collision vector may be set to each of the display elements.
If the subject of collision is the ground (S 104 , Ground), it is necessary to suspend the movement of display elements that fell together with the erased display elements but are still displayed since they have not directly landed on the ground. Thus, the CPU block resets data of the falling speed and rotation speed set to the group of display elements in the midst of the tell (S 106 ). When landing on the ground, it is possible to set is advance the number of displayable display elements and, when a number of display elements exceeding such number lands on the ground, erase the display elements at random.
Contrarily, if the display element did net collide with either the monster or the ground (S 102 , NO), the CPU block judges whether the moving speed and rotation speed have bees set (S 107 ). if some type of speed has been set (S 107 , YES), it means that the display element is falling and therefore the falling processing is performed (S 108 ). Details of the falling processing are explained at S 112 .
If no speed has been set to the display element (S 107 , NO), this display element is considered to not have directly contacted the monster and therefore does not fall. In the present embodiment, however, to realize a realistic picture, when a certain display element is erased, a picture of the display element adjacent thereto scattering in accordance with the intensity of impact is displayed. Therefore, when a judgment is made of the display element to be erased (S 110 , YES), the CPU block refers to the size of the impact vector set at step S 105 and judges whether the intensity of impact is larger than the minimum value Pmin (S 111 ). If larger (S 111 , YES), the CPU black calculates the movement speed, movement direction, rotation direction, rotation speed, and so forth of the parameter for displaying an image of this display element falling while rotating (S 112 ).
When a center portion of as object is destroyed, displayed is a large clod of the upper part being supported by a part of the display element. In the present embodiment, in order to reproduce a some of a building naturally collapsing upon becoming unbearable to the weight is such a case, the entire building collapses or remains in accordance with the number of display elements supporting the building. Thereby, eves if the intensity of impact of the monster is smaller than the minimum value Pmin (S 111 , NO), the aforementioned parameter calculation (S 112 ) is performed when the number of display elements supporting the object becomes less than a prescribed value min (S 113 , YES) with respect to the display elements on the same XY plane. This parameter is calculated respectively for the supporting display elements and the overall block of the remaining display elements collectively displayed thereabove. By this, it in possible to display an image of a building collapsing naturally in which only a small section of the blocks are remaining.
The parameter group calculated at atop S 112 is used for the actual coordinate position calculation of the display elements at step S 108 . That is, the CPU block calculates a new falling position and rotation angle per image renewal period. The CPU block completes the bitmap data by mapping texture data with respect to the display elements decided by the vertex coordinates (S 114 ).
FIG. 6 ( d ) shows an explanatory diagram of these parameters set for a single display element. For each display element, a normal line vector N is set. The movement direction of this display element is initially the direction of the collision vector X set for the display element, and speeds Vx, Vy and Vz corresponding to the respective coordinate components are set. A gravity speed component Vg is added to the Z axis component in order to reproduce a picture of the gravity working. By this setting, it is possible to display an image of a block falling is accordance with gravity. The speed setting, however, is optional. Even if setting the movement position in accordance with the acceleration speed, the collision vector may be irrelevantly set. If a block is structured from a plurality of display elements and the display elements within the block are intact, a single movement speed may be calculated for such block and the block may be dropped as one body.
The rotation is set in accordance with the relation between the collision vector I and normal line vector N. Larger the angle θ of the normal line vector N and collision vector I, the faster the rotation speed set by the CPU block. If the blocks rotating are set to simultaneously move without separating, the rotation speed may be set in accordance with the number of display elements constituting the block. For example, by setting such that larger the block slower the rotation and smaller the block, faster the rotation, it is possible to express a realistic collapse conforming to physical laws. The rotation direction may be set to either positive or negative in the plane including the normal line vector N and collision vector I. It is also possible to set the rotation direction in owe direction irrelevant to the vector. It is further possible to set the rotation direction in accordance with the position relation of the display element and collision point. For example, the rotation direction of the display element on the collision point may be set opposite to the rotation direction of the display element thereunder.
FIGS. 7 through 14 show display examples of the collapse of the structural object pursuant to the aforementioned processing. FIG. 7 in an image display example immediately after it has been judged at step S 102 that the tail T of the monster has collided with the structural object OBJ shown in FIG. 6 . An object E showing a flash and objects S 1 and S 2 showing powder smoke at the moment of collision are displayed.
FIG. 8 is an image display example where directly colliding display elements at step S 103 are erased and the display elements adjacent thereto are starting to fall. Display elements 10 , 11 and 27 are being erased upon directly colliding with the monster. As the size of the collision vector is larger than the minimum value Pmin (S 110 , YES, S 111 , YES) regarding display elements 9 , 12 , 26 , 28 and 40 adjacent to the erased display elements upon collision, they are starting to move and rotate (S 108 ) as the display position is changed based on the calculated parameter. It is also possible to set the connection relationship of the display elements to move without separating as in display elements 9 and 12 and display elements 26 and 28 .
FIG. 9 is an image display example of the display elements directly above and adjacent to the erased display elements collapsing. Display elements 1 , 12 , 26 , 28 and 40 which have fallen are erased at step S 103 since they have hit the ground. Display elements 7 , 8 , 24 and 25 are newly starting to fall based on the calculated parameter at step S 112 . Display elements which are no longer supported as the display elements directly therebelow have been erased may be set to fall irrelevant to the parameter calculation (S 112 ).
FIG. 10 is an image display example where the entire structural object is starting to fall since the supporting display elements are few. In this object OBJ, the upper object is only supported by two display elements 30 and 41 , and it is judged at step S 113 that it will not hold and begins rotating and falling based on the parameter calculated at S 112 . With respect to display elements 30 and 41 , they are independently falling based on a separately calculated parameter since a display element group is not formed. A single parameter is calculated with the whole thereof considered as a single object regarding the display element group that was on these display elements and start falling pursuant thereto. Display elements 7 , 8 , 24 and 25 which fell first have been erased at step S 103 since they hit the ground.
FIG. 11 is a final image display element of the upper object which collectively collapsed and landed on the ground. Display elements 30 and 41 which were supporting the upper object have hit the ground and disappeared. The upper objects which collectively collapsed have landed on the ground as well, but only display elements 21 , 23 and 25 that are in direct contact with the ground are erased at step S 103 . Although not erased, as the movement parameter has been reset at step S 106 with respect to the remaining display elements, a part of the collapsed object is still, and is displayed as the remains of the building which hit the ground. The first collapse is thus completed.
FIG. 12 is an image display example when a second attack is made to a part of the collapsed object. In the present embodiment, an object is continuously displayed unless such object directly hits the ground or becomes a minimum unit, in other words an individual display element, which is completely separated and cannot be separated any further. Therefore, it is possible to attack or carry and throw a part of the object that fell and is on the ground due to the first attack. The laser beam L fired by the monster C is hitting a part of the collapsed object. In other words, the object expressing the laser beam L is colliding with the collapsed structural object. The image displaying device displays an object flash E at the collision point and erases the display element judged as colliding with the direct laser beam L.
FIG. 13 is an image display element of a display element, which is adjacent to the display element erased due to the impact upon laser beam irradiation, being scattered. As the size of the collision vector set at step S 105 is larger than the minimum value Pmin (S 111 , YES), parameters for movement and rotation have been set at step S 112 . Here, display elements 7 , 8 , and 32 and display elements 3 and 6 are moving as a single clod of a display element group without being mutually separated. The block consisting of display elements 7 , 8 and 32 is colliding with display elements 29 and 42 which structure the basic portion of the building remaining without collapsing. Cases like this, where the display elements collide with each other and disappear, may also occur.
FIG. 14 is an image display example of the completion of the second attack. Display elements 3 , 6 , 7 , 8 , 20 , 22 and 24 that have scattered and separated due to the impact of the laser beam fired from the monster are erased by hitting the ground or being separated into minimum units. Display elements 7 , 8 and 32 scattered as blocks are similarly erased by directly colliding with the basic portion of the building or being separated. The remaining display elements 39 , 42 structuring the basic portion of the building are also erased by the block directly colliding thereto. Like this, each of the display elements is erased under the condition of directly colliding with a character or ground or being separated. In comparison to crushing and erasing an object with only the first attack, it is possible to express a more realistic form of destruction. By employing this method, there is also an advantage that the burden on the CPU within a short period is decreased.
FIG. 15 is a display example a structural object and monster character in which texture mapping has been performed. By the character C contacting the structural object OBJ 1 , a flash E occurs, and the structural object is broken down into a plurality of blocks and is starting to collapse. The elapsed time from the start of the game is displayed on the upper right-hand corner of the screen, and the ratio of the object destroyed in comparison to the overall object is displayed on the lower right-hand corner of the screen.
FIG. 16 shows a display example of other structural objects and monster characters. The object OBJ 2 is being destroyed by the laser beam L fired from the character C. Objects OBJ 3 and OBJ 4 are intact.
Area-Out Processing
Next, the area-out processing in the present embodiment is explained. The present game device performs area-out processing when a monster exceeds a prescribed movable range. This is because if the monster may freely move without any restrictions, a prescribed number of objects will deviate from the set range.
FIG. 17 shows a plane conceptual view in the virtual space for explaining this area-out processing. An area A with a radius r is set in the center position O of the game. The monster C 0 is within this area. Monsters C 1 and C 2 are out of this area. The viewpoint position within the virtual space capable of capturing the monster is set in a position relationship relative to the monster. The viewpoint is set in accordance with the position of the monster in the world-coordinate system. When the monster goes out of this area A, the viewpoint is set to a position to capture the monster from behind. This is in order to give an impression that the monster is receding from view. In such case, fog processing is performed in the present embodiment based on the flowchart of FIG. 4 . While the monster is receding from view, an impression of it disappearing into the fog is given. This is in order to hide the scenery outside the area because, if no objects are set and displayed as is, such scenery will be bleak and unnatural.
First, the renewal timing is awaited (S 200 , NO), and when it is the renewal timing (S 200 , YES), judgment is made as to whether the character is inside or outside the area by referring to the center coordinates of the character. If the character is within the area (S 201 , NO) transition is made to another processing (S 208 ). A picture of a standard monster C 0 is displayed on the screen in such a case as shown in FIG. 18 ( a ). Contrarily, if the character is outside the area (S 202 , NO), transition is made to the area-out processing.
If the time is not yet running (S 202 , NO), the CPU block turns on the internal timer (S 203 ). This timer is used for the countdown of the area-out. If the timer is running (S 202 , YES), judgment is made as to whether it is time out. If not time out (S 204 , NO), the distance between the boundary of area A and the character is calculated (S 206 ). Then, the degree of brightness and color to be added to the character's bitmap data in correspondence with the calculated distance is set, and addition of bitmap data is performed (S 207 ). It is preferable to also set and add the degree of brightness and color in correspondence with the distance from the area boundary with respect to objects other than characters outside the area. According to this processing, if the distance from the area A in FIG. 17 is d 1 , the image including the character C 1 is shown as in FIG. 18 ( b ). In comparison to FIG. 18 ( a ), the degree of brightness and color has been changed, and the character becomes dim and fades into the fog. The farther the distance between the area A and the character, the stronger the displayed dimness. Window W 1 on the screen displays the remaining time in correspondence with the timer value. Characters for notifying the area-out is displayed on window W 2 . When time out (S 204 , YES), game over processing is performed (S 205 ). For example, the picture when it becomes time over at the position of the character C 2 in FIG. 17 will be displayed as in FIG. 18 ( c ). The outline of the character is further dimmed. The remaining time displayed in window W 1 becomes zero, and a character display of time over is displayed on window W 2 . The processing for placing fog on the character may be set by, in addition to controlling the software, setting the overall degree of brightness and color to automatically increase in a density corresponding to the parameter provided by the hardware. Especially, if structured such that the synthesis of the bitmap is performed in accordance with the distance between the character and the viewpoint, a display wherein a distant character is completely hidden in the fog and a near character is dimmed in accordance with its distance is possible.
Damage Processing
Next, damage processing of the present embodiment is explained. In conventional games when the character was attacked, a picture of either the character suddenly collapsing or no change at all was displayed. When the character is a large monster as in the present embodiment, however, it is unnatural if such monster were to be easily defeated. The character being absolutely invulnerable will also lower the amusement of the game. The present game device therefore performs damage processing when the character is attacked and displays the injured character. A flowchart for explaining this damage processing is shown in FIG. 5 .
The renewal timing of the image is foremost awaited (S 300 , NO), and when it is the renewal timing (S 300 , YES), judgment is made as to whether the character is damaged or not (S 301 ). Whether the character is damaged or not may be judged by the collision judgment between, for example, a bullet object and character. The damage flag is turned on (S 302 ) only when the character sustains a new damage (S 301 , YES). A message indicating the damage, and position data showing the damaged portion or polygon specifying data are stored in the damage flag. A damage flag is generated for each new damage. When a cannonball hits the abdominal region 201 of the character 200 , for example, a flash E is displayed as shown in FIG. 19 .
The CPU block then sets the character's posture in accordance with the existence of the damage flag. If the damage flag is no on (S 303 , NO), set is the posture which is ordinarily set (S 304 ). Contrarily, if the damage flag is on (S 303 , YES), the CPU block displays the character's posture according to the damaged portion (S 305 ). As shown in FIG. 20, for example, displayed in an object 202 with blood dripping from the abdominal region 201 . The position of each of the polygons structuring the character 200 is adjusted such that the character is in a posture of protecting such abdominal region.
The CPU block further judges whether a recovery condition has been fulfilled (S 306 ). Recovery conditions are optionally set conditions. Specifically, when a character conducts a prescribed act, the act of “regaining energy by eating” for example, the recovery condition is fulfilled. A recovery condition may also be fulfilled upon a prescribed period of time elapsing from the time of sustaining damage. In other words, an image of a creature recovering from the damage is displayed. If the recovery condition is not fulfilled (S 306 , NO), transition is made to another processing (S 308 ) and an image of the posture of the damaged character is continued to be displayed. On the other hand, if the recovery condition is fulfilled (S 306 , YES), the CPU block resets the damage flag (S 307 ). The character is then displayed in the standard posture from the next image renewal period. If sustaining a plurality of damages, however, and a damage flag is remaining, an image of the posture of the damaged character is maintained.
Evaluation Processing
When it is game over, the CPU block displays a screen as shown in FIG. 21 and evaluates the game content. In window W 3 , a plurality of indicators IND for evaluating the player's operation technique are displayed classified by categories. Window W 4 is a column for displaying characters representing the character's title given as the overall evaluation.
With respect to the evaluation per category in Window W 3 , the “DESTROY” column displays the percentage with index M of the number of polygons destroyed in consideration of the destructible number of polygons of the object set at 100. The “SPEED” column displays the percentage in index M of the ratio of the time required to clear the game in consideration of the time limit in the game (5 minutes for example) set at 100. The “SHOOT” column displays the percentage in index M of the number of enemies destroyed upon clearing the game in consideration of the number of enemies appearing during the game (fighter planes for example) set at 100. The “POWER” column displays the percentage in index M of the power value upon clearing the game in consideration of the maximum power of the monster character set at 100. The “COMBO” column evaluates the consecutive attacks made by the player. That is, the display elements constituting the structural object are divided into a certain number of blocks. When an attack is made to the object, these blocks are erased and dropped in block units. When a block starts falling due to the first attack, it is possible to conduct a second attack to such block. The “COMBO” column displays the percentage in index M of the number of blocks destroyed by consecutive attacks in consideration of the number of overall blocks set at 100. The “BALANCE” column evaluates the maneuver balance of the character. That is, upon attacking the blocks constituting the structural object, the CPU block records the “maneuver” required for the destruction thereof. Examples of “maneuvers” include tail attack, hand attack, laser beams, etc. With a premise that it is preferable to destroy the object with well-balanced “maneuvers,” the CPU block records the destruction number of the block per maneuver. The “BALANCE” column displays the percentage in index M of the balance evaluation upon clearing the game by comparing the difference in the destruction ratio of the blocks destroyed pursuant to each of the maneuvers and the standard value.
The title in window W 4 is determined pursuant to the overall ratio of the evaluation of the six categories upon respectively evaluating and obtaining the results of the aforementioned six categories. Several titles are predetermined corresponding thereto in the order from a high evaluation to a low evaluation. The CPU block obtains the overall percentage based on these six categories, reads a title corresponding thereto, and displays the same on window W 4 .
(Advantages)
There are the following advantages according to the present embodiment as mentioned above:
1) According to the present embodiment, as the structural object is constituted of block-shaped display elements after a collapse, a display of a realistic collapse of a building is possible by merely separating the object per display element.
2) According to the present embodiment, as the outline of each display element is set to simulate a block clod created upon an actual collapse of a building, a display of a realistic collapse of a building is possible.
3) According to the present embodiment, as a display element is erased upon colliding with a character or the ground, it is possible to display a realistic scene of a part of the building being destroyed or the crushed block disappearing.
4) According to the present embodiment, as a display element directly above the erased display element is dropped, it is possible to display a realistic collapse of a building with a time lag as when a building is destroyed in a monster movie.
5) According to the present embodiment, when a display element is erased, a display element adjacent thereto is moved at a speed according to the intensity of impact and a display of an image where a display element is scattered far in accordance with the intensity of impact is possible.
6) According to the present embodiment, when a display element is erased, a display element adjacent thereto is moved toward a direction according to the direction of impact and a display of an image where a display element is scattered in a direction in accordance with the direction of impact is possible.
7) According to the present embodiment, when a display element is erased, a display element adjacent thereto is rotated at a rotation speed according to the size of the display element and a display simulating a rotation of the block conforming to the laws of nature is possible.
8) According to the present embodiment, when the intensity of impact exceeding a prescribed value is inflicted upon an object, the display position of an adjacent display element is changed. Thus, it is possible to realistically display a building immediately before collapsing wherein such building is barely supported by a partial pillar.
9) According to the present embodiment, when a display element is erased and the remaining display elements are barely being supported, the blocks on top of the supporting display elements are collectively dropped when the number of such supporting display elements is less than a prescribed number. It is therefore possible to display a realistic picture of the building collapsing.
10) According to the present embodiment, as the remaining object after the collapse is also structured to be destructible as another separate object, a further realistic image is provided. For example, it is possible to provide a realistic image where a monster further tramples over a part of a collapsed building just like in a monster movie. Another advantage is that less burden is placed on processing in comparison to a building being crushed with only the first collapse.
11) According to the present embodiment, the blocks after a collapse may be erased naturally as the display elements separated in minimum units are erased. In other words, the blocks erased from the screen are inconspicuous if they are in minimum units, and an unnaturalness of an object suddenly disappearing will not be conveyed to the player. A character may also use a part of the object not separated into minimum units after a collapse as a weapon (stone-throwing for example). A part of the object which became this weapon will collide with other characters, be separated into minimum units, and disappear. A new game processing method is provided wherein a character may be supplied with a weapon without unnecessarily increasing the number of usable weapons in the game.
12) According to the present embodiment, when a character goes out of the area, an image of a fog is displayed, and an unnecessary display outside the area may be naturally avoided. By gradually displaying the character such that it recedes from view, it is possible to naturally inform the player of the movable range of the character.
13) According to the present embodiment, as the density of the fog is changed in accordance with the distance between the character and the area boundary, it is possible to display a natural image of the fog becoming denser while the character is receding from view.
14) According to the present embodiment, as time out processing is performed while the character is outside the area, it is possible to end the game naturally in the fog.
15) According to the present embodiment, when it is judged that a character collided with another object, the character's posture is changed until the recovery condition is fulfilled, and it is therefore possible to naturally display an image of a character as though it has sustained damage.
16) According to the present embodiment, as the posture is set such that the character protects the place of collision, it is possible to display a creature's instinctive actions.
17) According to the present embodiment, as a character is made to recover by conducting predetermined movements, it is possible to display a creature's instinctive actions such as recovering by supplementing energy.
18) According to the present embodiment, as a character is made to recover by a predetermined period of time elapsing, it is possible to display a creature's instinctive actions such as recovering with the lapse in time.
19) According to the present embodiment, as consecutive attacks are evaluated in COMBO, it is possible to provide a worthy game to advanced players who are capable of conducting consecutive attacks.
20) According to the present embodiment, as maneuver balance is evaluated in BALANCE, it is possible to provide a worthy game to advanced players who are capable of combining several maneuvers.
21) According to the present embodiment, as a title is given as the overall evaluation, it is possible to provide a continuously appealing game by showing a target evaluation (title) to the player.
(Other Examples)
The present invention is not limited to the embodiment above but may also be employed upon being changed within the scope of the purport of the present invention. Display elements of the present invention, for example, may also be employed to objects other than structural objects. For example, display elements may also be employed to objects representing characters or natural objects such as mountains.
The method of erasing and dropping the display elements is not limited to the above, and is employable upon various changes in planning. The combination of blocks as display element groups can also be set optionally.
According to the present invention, it is possible to realistically collapse a building by structuring objects such as buildings with blocks to be collapsed.
According to the present invention, it is possible to naturally restrict the movable range of the character by displaying a picture where the character is covered with fog in accordance with the moving position.
According to the present invention, it is possible to realistically represent the degree of damage to the character by structuring the posture of the damaged character to be changeable.
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A realistic image of buildings collapsing, as in a monster movie, is displayed. Each of the display blocks to be scattered after the collapse is previously set as collective movable display elements ( 1˜29 ), and objects (OBJ) simulating buildings and the like composed of display elements are structured and displayed. By separating the display elements, it is possible to create an image similar to concrete blocks after as actual collapse. Further realism is provided by changing the way the blocks fall upon a collapse of a building.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part application of application Ser. No. 09/672,197, filed Sep. 28, 2000, which is a continuation of Ser. No. 09/019,352, filed on Feb. 2, 1998, now U.S. Pat. No. 6,155,958, which is a continuation of Ser. No. 08/736,976, filed on Oct. 25, 1996, now U.S. Pat. No. 5,722,916, which is a continuation of application Ser. No. 08/391,438, filed on Feb. 21, 1995, now abandoned, which is a continuation of Ser. No. 07/969,765, filed on Oct. 30, 1992, now U.S. Pat. No. 5,423,728.
BACKGROUND
Having a stationary exercise bicycle capable of simulating outdoor bike riding is valuable.
This invention relates to a stationary exercise bicycle which is sturdy and comfortable for use during extended periods of pedaling while standing or sitting or a combination thereof and thus capable of meeting the needs of the more demanding rider.
In recent years, the popularity of the stationary exercise bicycle has increased dramatically together with the fitness craze. Stationary exercise bicycles are conventionally made with straight, brazed round tubing. A problem associated with using the round tubing in these bicycles is their propensity for fragility. They easily snap under increased stress, for example, during periods when the rider is pedaling in a standing position or in an alternating standing and sitting pedaling position. Also, the bicycle structure does not provide for the best flexibility according to the preferences of the rider.
There is a need to provide a stationary exercise bicycle which is more durable and overcomes the problems of the prior art.
SUMMARY
The invented stationary exercise bicycle seeks to avoid the disadvantages associated with conventional stationary exercise bicycles.
According to the invention, the stationary exercise bicycle comprises a stable frame. Additionally, the frame comprises a front socket and a rear socket, and front and rear ground support elements. Also provided is a pedal mechanism on said frame.
Also, the bicycle comprises a detachable seat socket. A seat is mounted on a seat socket at a level above the pedal mechanism. The seat is mounted for movement fore and aft relative to the seat socket and upwardly and downwardly relative to the pedal mechanism.
Additionally, the stationary exercise bicycle comprises a handlebar mounted in the front socket. The handlebar includes at least two different handle means. One handle means includes spaced apart and outwardly directed elements. The second handle means includes an element inwardly located relative to the first handle means. The handlebar is adjustable in the front socket.
Further, in one preferred form, the frame comprises at least multiple upstanding posts. The posts are inter-engaging to form at least one triangulated or V-shaped structure between the ground support elements and one of the sockets.
Additionally, at least part of the front socket, rear socket, or seat socket are formed with a hollow member having a cross-section which is non-cylindrical.
The pedal mechanism may include a cog operative with an endless chain having slots for engagement with the cog. A ring guard is provided and protective of at least the interaction of the teeth of the cog with the endless chain. The ring guard is located internally of the perimeter defined by the endless chain.
The invented stationary exercise bicycle is strong and comfortable for the rider. The adjustability of the bicycle facilitates comfortable riding of the bicycle in multiple positions, for example, sitting, standing and different gripping positions. Moreover, it is stress-resistant so that it can be used by the rider in a standing position or in an alternating standing and sitting pedaling position for extended periods. Riders of this bicycle can simulate the aerobic effect of mountain bike racing.
According to another aspect of the invention, a method of exercising on the stationary exercise bicycle comprises adjusting the height and the fore and aft position of the seat and optionally also adjusting the height of the handlebars to facilitate riding the stationary exercise bicycle in multiple positions and then riding the bicycle in multiple positions to simulate different bicycle riding conditions.
Additionally, the invented stationary exercise bicycle is mobile and the parts, easily replaceable. Unlike conventional stationary exercise bicycles, the present invention utilizes regular bicycle components. The user can replace certain parts from conventional bicycle shops and thus service the present invention with conventional bicycle componentry. Further, unlike prior art stationary exercise bicycles, the present invention has four basic parts which are detachable and can be placed in a portable transport carrier for mobility.
According to a further aspect of the invention, the novel stationary exercise bicycle may comprise a deflector mounted underneath the front socket and a portion of a down tube coupling the front socket to the rear socket. The deflector advantageously prevents sweat, accumulating on a rider, from entering into the flywheel mechanism. In this manner, increased corrosive resistance is effected. In a similar manner, the novel bicycle may comprise a chain guard 56 that entirely encapsulates the chain, hub, and other working components so as to enhance corrosion resistance even further.
The down tube of the novel bicycle is preferably rectangular in shape and generally large in cross section. Such a structural difference advantageously permits better rigidity, lower cost, and by eliminating welds, an increased resistance to corrosion. Welds are eliminated by advantageously eliminating an arm or cross-element, further increasing rigidity and support. Moreover, this feature allows for a larger seat post member to be matingly engaged in the rear socket to advantageously accommodate taller riders.
The invention is now further described with reference to the accompanying drawings.
DRAWINGS
FIG. 1 is an isometric view of a frame for a stationary exercise bicycle;
FIG. 2 is an isometric view of the pedal mechanism and a flywheel, both shown in phantom, including the ring guard, cog, and endless chain;
FIG. 3 is a detailed view of the ring guard in relation to the cog and frame;
FIG. 4 is an isometric view of the front fork triangle and an upstanding post;
FIG. 5 is an isometric view of the seat socket and the connective member;
FIGS. 6A, 6 B, and 6 C are isometric, front and side views, respectively, of the adjustable and detachable handlebar including the forwardly extending prongs, the lateral bar, and the element inwardly located relative to the forwardly extending prongs;
FIG. 7 is an isometric view of the triangulated structure portion of the frame;
FIG. 8 is an isometric view of an alternative frame; and
FIG. 9 is a perspective view of another preferred embodiment directed to a novel stationary bicycle.
DESCRIPTION
A stationary exercise bicycle comprises a frame 1 (FIG. 1) or 24 (FIG. 8 ). The frame has a central ground support element 31 , front 2 and rear 3 ground support elements, a down tube 52 , multiple upstanding posts 13 , a front socket 4 and a rear socket 5 and a pedal mechanism 6 . As discussed below and as shown in FIG. 2, pedal mechanism 6 generally includes a crankarm and crankset. The rear socket 5 is capable of receiving a seat socket 12 . Further, a seat 20 may be mounted on the seat socket 12 at a level above the pedal mechanism 6 . The seat 20 is mounted for movement fore and aft relative to the seat socket 12 and upwardly and downwardly relative to the pedal mechanism 6 .
This stationary exercise bicycle further comprises a handlebar 8 mounted in the front socket 4 . The handlebar 8 includes at least two different handle means 9 and 10 . One handle means includes spaced apart and outwardly directed elements 9 . The second handle means includes an element inwardly located 10 relative to the first handle means.
The outwardly directed handle means 9 have forwardly extending prongs 9 A and 9 B (FIG. 6A) which are directed axially away from the seat socket 12 . The axially directed prongs 9 A and 9 B are connected with a lateral bar 11 of the handlebar 8 at one end and are free at an opposite end.
The inner handle means 10 is at least part of a closed ring. The ring is located between the outer handle prongs. Further, the ring is connected to a lateral bar 11 of the handlebar 8 .
The closed ring may be a semi-circle. The axis for the semi-circle is located substantially about midway through the lateral bar 11 of the handlebar 8 .
The handlebars have been designed with the user's handlebar position needs in mind. Because of the need for the different hand positions during the ride, the ring allows for different hand positions, movements, quick transition from sitting to standing, and standing back to sitting. It also allows, without the use of an attached arm pad, the ability to lie the forearm on the ring portion of the handlebar and simulate a real training cycling position.
The handlebar 8 may be connected to the frame 1 or 24 by the front socket 4 . A handlebar pop pin 22 permits adjustment of the handlebar 8 according to the requirements of the rider. FIGS. 6A and 6B show the holes which permit the connecting member to be arrestable by a pop pin for adjustment.
Applicant contemplates that alternative handlebars may be connected to the frame 1 or 24 in accordance with the rider's needs.
The frame 1 (FIG. 1) or 24 (FIG. 8) further comprises at least multiple upstanding posts 13 . In a preferred form, the posts inter-engage to form at least one triangulated structure 14 between the ground support elements 2 or 3 and one of the sockets.
The frame 1 includes at least two triangulated structures 7 and 14 between the sockets 4 , 5 , and 12 . The two triangulated structures 7 and 14 have at least one common upstanding post 13 forming at least one wall of the triangulated structures 7 and 14 . One of the triangulated structures 7 and 14 includes an arm or cross-element 6 A intended to mount the pedal mechanism 6 .
The upstanding posts 13 form part of the triangulated structure 7 and 14 . Moreover, the upstanding posts 13 are all located at a non-horizontal, non-vertical axis.
The triangulated structures 7 and 14 include the rear triangle 14 A which includes an inverted V-shaped section and which functions to stabilize the frame 1 ; the bottom bracket triangle 14 B which includes an upstanding V-shaped section and which functions to stabilize the frame 1 so a rider can pedal standing; the front triangle-like structure 7 which functions to permit total range of motion; and a front fork triangle 18 .
The rear triangle 14 A is important as a stabilizing block. Unlike conventional stationary exercise bicycles, the small base of this triangle gives the bike its total rigidity in the rear.
The bottom bracket triangle 14 B gives the central part of the stationary exercise bicycle its rigidity and form for standing. Further, arm or cross-element 6 A allows for conventional pedal mechanisms (i.e., crankarm and crankset) to be used with a conventional clipless pedal or a regular bicycle pedal and toe clip.
The front triangle-like structure 7 is wide enough to house a flywheel (FIG. 2 ). The front triangle-like structure 7 gives the stationary exercise bicycle its total range of motion moving the flywheel in and out and giving the stationary exercise bicycle its base length or reel length from foot position to foot position.
The flywheel is connected to the frame 1 or 24 by the front forks 13 and the front fork triangle 18 .
Further, at least part of the front socket 4 , rear socket 5 , or seat socket 12 are formed with a hollow member having a cross section being non-cylindrical. The sockets described herein permit a matingly shaped connecting member (such as the handlebar 8 , the adjustable and detachable seat 20 ), the connecting member being arrestable by a pop pin 19 , 21 , or 22 .
The hollow member may have a polygonal cross section (preferably quadratic). For example, in the illustrated example, the polygonal cross section is substantially square.
The seat is adjustable for height and connected to the seat socket 12 . The seat post pop pin 19 permits height adjustment of the seat. The fore and aft saddle pop pin 21 permits adjustment of the seat 20 by sliding fore and aft in the seat socket 12 .
Because of the adjustability of the seat and the handlebar, a rider theoretically may be as tall as 15 feet and weigh up to 900 pounds. The handlebar and seat adjustability provides for a versatile bicycle which can be used by persons of many different physiques, from small, light and short to large, tall and heavy.
Referring now to FIG. 3, the pedal mechanism 6 includes a cog 15 operative with an endless chain 16 having slots for engagement with the cog 15 . Additionally, the pedal mechanism 6 includes a ring guard 17 protective of at least the interaction of the teeth of the cog 15 with the endless chain 16 . The ring guard 17 is located internally of the perimeter defined by the endless chain 16 .
It would be desirable to provide attachments to the present invention. For example, a water bottle may be attached directly to the present invention or indirectly by means of a Velcro™ device or any carrier means for attaching the water bottle to the stationary exercise bicycle.
Additionally, an ergometer may be attached to the present invention. Also, a computer controlled energy measuring and indicating device may be attached to the present invention.
The stationary exercise bicycle may comprise a dual chain tension device which is adjustable while the rider is in motion. Moreover, the stationary exercise bicycle may comprise a cable resistance braking system which permits the rider to adjust the resistance of the flywheel. A resistance plate 23 may support a cable to the flywheel.
The length and width of the stationary exercise bicycle is appropriate for standing and sitting while pedaling. Additionally, the width is appropriate for pedaling while sitting and for stabilization when the rider pedals while standing and rocking the body from side to side.
In a preferred form, the triangulated structures 14 A, 14 B, 7 stabilize the stationary exercise bicycle. These triangulated structures form the “integrity” structure of the stationary exercise bicycle.
The symmetry of this machine is very basic. The genius in the present invention is in its simplicity. The present invention simulates road conditions exactly as if the rider is pedaling a conventional, non-stationary bicycle.
Applicant contemplates many other examples of the present invention each differing by detail only. For example, there are many variations of the sockets described herein. The sockets described herein may not only permit a matingly shaped connecting member to fit inside (such as the handlebar 8 , the adjustable and detachable seat 20 ), the connecting member being arrestable by a pop pin 19 , 21 , or 22 . In fact, the matingly shaped connecting member may be a hollow into which the socket fits, e.g., the rear, front, or seat socket.
Additionally, the handlebar 8 may include at least two different handle means. One handle means includes spaced apart and outwardly directed elements 9 . The second handle means may include an element (e.g., a closed ring) outwardly located relative to the first handle means.
Further, in one form, the frame may have a plurality of segments. Instead of a single unit, the frame may collapse into several units which permits even greater mobility of the stationary exercise bicycle for transport. Each unit of the frame may be re-assembled using bolts or any other type of well known connecting means.
FIG. 9 illustrates an example of the present invention that is substantially similar to the preferred embodiments shown in FIGS. 1-8. The structural differences of this embodiment, with their corresponding functional advantages, are set forth below.
Turning to FIG. 9, a deflector 50 can be seen mounted underneath the front fork triangle 18 extending toward a down tube 52 . A fastening member 54 , such as a screw, bolt, or the like, couples the deflector 50 to the front socket 4 . The deflector 50 is preferably a one-piece unit made from a flexible polymeric material, allowing for this plastic piece to be economically manufactured via injection molding or similar process.
The deflector 50 advantageously prevents sweat, accumulating on a rider, from entering into the flywheel mechanism. In this manner, increased corrosive resistance is effected.
As shown in FIG. 9, the down tube 52 couples the front socket 4 to the rear socket 5 . The down tube 52 may be rectangular in shape and generally large in cross section. Such a structural difference advantageously permits better rigidity and lower cost, and by eliminating welds, an increased resistance to corrosion. Welds may be eliminated by directly mounting the down tube 52 to the rear socket 5 and by directly mounting pedal mechanism 6 to the down tube 52 that may advantageously eliminate the arm or cross-element 6 A as shown in FIG. 1 and FIG. 8 . Such direct coupling further increases rigidity and support. Moreover, this feature allows for a larger seat post member to be matingly engaged in the rear socket 5 to advantageously accommodate taller riders.
FIG. 9 also illustrates a unique chain guard casing or encapsulation 56 disposed proximate the down tube 52 . The chain guard casing 56 entirely encapsulates the chain, hub, and other working components (shown, for example, as chain 16 in FIG. 2) so as to further enhance corrosion resistance.
FIG. 9 also illustrates a cover or encapsulation 57 that may be attached to frame 1 at down tube 52 and rear socket 5 . As shown, cover 52 may protect down tube 52 and rear socket 5 , and the weld therebetween, from the sweat that may fall down from a rider. This is advantageous because without cover 57 , sweat might accumulate at the weld between down tube 52 and rear socket 5 .
The handlebar 8 of this embodiment preferably has rounded ends, as shown in FIG. 9, to enhance safety and provide an ergonomic benefit to the rider. The handlebar 8 is also preferably made from stainless steel to increase this part's resistance to corrosion.
As seen in FIG. 9, the posts or forks 13 are closer together compared to those shown in the prior drawing figures. This arrangement allows for better rigidity and increased corrosion resistance due to a tighter fit between the components.
Wheels 58 coupled to the frame 1 advantageously allow for easy portability of the novel stationary bicycle.
Leveling pads 60 add stability and allow the user to compensate for non-level surfaces.
Thus, while embodiments and applications of the novel and improved stationary exercise bicycle have been shown and described, it would be apparent to one skilled in the art that other modifications are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the claims that follow.
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A novel stationary exercise bicycle and method for exercising on that bicycle is disclosed. The novel bicycle, comprising a frame having front and rear sockets, a seat mounted into the rear socket, and a handlebar mounted in the front socket, can advantageously be adjusted so that a rider can adopt different riding positions to simulate outdoor bicycle riding conditions.
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This is a division of application Ser. No. 08/116,863, filed Sep. 3, 1993 now U.S. Pat. No. 5,385,646
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is generally related to industrial chemical production plants and waste water treatment, and is more specifically directed to a novel apparatus configuration and method for using the same to recover raw materials, by-products and product from the dilute process condensate streams of chemical production plants. The recovered materials are recycled for use in the production facilities in such a manner as to avoid any significant energy or other efficiency penalties which could negatively impact the plant's operation and overall effectiveness.
2. Description of the Related Art
Large quantities of industrial waste water are daily produced by chemical production and processing plants within the United States and throughout the world. Often times, this waste water is process condensate consisting of dilute streams of raw materials, byproducts and product remaining unrecovered from processing water and/or steam used in various phases of production. For example, in the production of ammonia, steam exiting the plant after use in stripping operations carries trace amounts of methanol, ammonia, carbon dioxide, alkylamines and the like. Although the materials within these streams could be utilized to form product, due to the dilute nature of the condensate, it is generally more cost efficient to simply consider the water as waste water and dispose of the same as needed.
At one time, the bulk of process condensate and industrial waste water was simply discharged into live streams or municipal sewer systems without treatment. However, in view of the potential environmental damage that could result from the release of chemicals into the water systems, as well as the need to conserve the amount of water used daily in operations, methods have been developed for treating the water to remove any contaminants therefrom and recycle the water back to phases of the plant for reuse.
In the field of ammonia production, for example, it is known to use a relatively low pressure steam stripping apparatus such as a conventional stripping tower to treat the process condensate, wherein steam is utilized to strip the contaminates from the condensate. The contaminated overhead is then vented to the atmosphere while the stripped condensate is reused in the plant as cooling tower water make-up, boiler feed water make-up and the like. Alternatively, the contaminated overhead may be destroyed or decomposed such as by burning. Although these conventional low pressure strippers are useful for this purpose, the amount of contaminants and/or noxious vapors vented to the atmosphere is undesirable. In fact, the type and amount of such emissions is the subject of increasingly stringent regulation by the Environmental Protection Agency (EPA), as well as other state and local officials. It is anticipated that the level of emissions now permitted will be substantially reduced in the future, particularly as to potentially harmful compounds such as ammonia and methanol, and will perhaps eventually be prohibited altogether.
In order to overcome these emission problems, a more recently developed method of treating ammonia plant process condensate utilizes relatively high pressure condensate stripping towers, generally operating at 500 pounds pressure (psi) or more to strip contaminants from the condensate. In this method, the high pressure process steam carries the contaminated stripper overhead back to the plant for use in the primary reformer stage of production. Although return of the contaminates to the ammonia plant avoids undesirable venting of contaminants into the atmosphere, injection of the relatively high pressure stream of overhead into the plant requires that it be flow controlled and be considered along with the normal steam flow to the primary reformer in setting the steam-to-gas ratio. This has the effect of lowering the front-end pressure of the system, lowering ammonia plant capacity and efficiency as well as complicating process control overall. In addition, the high pressure strippers are relatively very expensive and their use requires the complete replacement of the more conventional low pressure strippers that are presently used in many plants throughout the world.
Therefore, it is a primary object of the present invention to provide an apparatus and method of treating chemical plant process condensate, wherein the raw materials, product and byproducts (hereinafter referred to collectively as "contaminants") in the condensate are recovered from the water for reuse in the plant.
It is another object of the present invention to provide an apparatus and method of treating process condensate, wherein contaminants in the condensate can be recovered and returned to the plant without accruing significant efficiency penalties to the plant or requiring plant modification.
It is another object of the present invention to provide an apparatus and method of treating process condensate, wherein a conventional low pressure steam stripping tower may be utilized.
Another object of the present invention is to provide an apparatus and method of treating process condensate, wherein a plant using a conventional low pressure steam stripping tower for condensate treatment can be retro-fitted to enable the concentrating and recycling of recovered contaminants back to the plant.
It is another object of the present invention to provide an apparatus and method of treating process condensate that is relatively efficient and cost effective.
A further object of the present invention is to provide an apparatus and method of treating process condensate wherein contaminant air emissions are effectively eliminated.
Yet another object is to provide an apparatus and method of treating process condensate, wherein a substantial amount of the water in the condensate can be recovered having a reduced contaminant content so as to be suitable for reuse in the plant as boiler feedwater make-up which requires high quality, low conductivity water.
Yet a further object of the present invention is to provide an apparatus and method of treating ammonia and/or methanol plant process condensate meeting the objectives heretofore described.
SUMMARY OF THE INVENTION
These and other objects are achieved by a novel apparatus configuration and method of using the same to recover product, by-products and raw materials from the process condensate of a chemical production plant. The method comprises stripping the contaminants from the condensate in a relatively low pressure stripping section of an upright tower to obtain a contaminant-rich overhead vapor and an aqueous bottom stream of reduced contaminant content, followed by rectification in a rectification section of the tower to obtain a concentrated overhead stream. The tower overhead is then totally condensed with a portion of the condensed overhead stream being returned to the top of the rectification section of the tower as reflux, and the balance is withdrawn as a concentrated stream for re-use in the plant.
Due to the low volume nature of the concentrated overhead stream withdrawn, the contaminants can be efficiently injected back into the plant at the appropriate stage for decomposition, recycling and/or reuse within the plant without significant thermal, pressure or energy impact on the plant and its operation, thus requiring no plant modification or accrueing significant efficiency penalties. As with other stripping operations, the stripped condensate is removed from the tower as bottoms liquid which may also be recycled such as for use as boiler feed water and/or cooling tower water make-up and the like.
In an alternative embodiment, separate stripping and rectification columns operating in series are provided, whereby the overhead vapor of the stripping column is delivered to the base of the rectification column. The rectification bottoms are returned to the top of the stripping tower for further stripping action. The concentrated overhead from the rectification column is then totally condensed with a portion returned to the top of the rectification column as reflux and the remainder being withdrawn as a concentrated stream for recycling to the chemical production plant.
The method and apparatus configuration of this invention can be utilized in conjunction with conventional low pressure steam strippers, such as those previously used for treating ammonia plant process condensate, by retrofitting the existing stripping tower to include a rectification section at its top or by adding a separate rectification column in series. Not only does the retrofitted system eliminate the environmental concerns associated with the prior technique of venting contaminates, it enables substantially the whole of the process condensate contaminates generated by the plant to be converted into feed stock which can be recycled to the production facility for use.
This apparatus and method achieve a marked improvement in the overall economics and operation of the chemical production plant complex, making it possible to obtain the advantages now associated with relatively high pressure strippers while avoiding the enormous costs associated with such systems, and the energy and pressure penalties which necessarily accrue to the production plant via their use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of an apparatus configuration having a common tower for stripping and rectification in accordance with the present invention;
FIG. 2 is a schematic representation of an apparatus configuration having separate stripping and rectification
columns in accordance with the present invention; and
FIG. 3 is a schematic representation of a preferred embodiment of the invention of FIG. 1, wherein the apparatus is provided for the treatment of ammonia plant process condensate.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a novel method and unique apparatus configuration for treating chemical production plant process condensate. The process condensate treated may generally include any effluent generated by chemical production and processing operations, and will normally comprise a dilute aqueous stream of the raw materials utilized in processing, as well as product and by-products formed in various stages of production. For purposes of this application the product, by-product and raw materials contained in the condensate shall be referred to collectively as "contaminants". Depending upon the nature of the processing steps from which the condensate is generated, this effluent may be presented for treatment in the form of a gaseous or liquid stream. The condensate may be used at its recovery temperature without preliminary treatment and will preferably have a temperature ranging near its bubble point for the stripping operation pressure as hereafter described.
Referring now to the embodiment shown in FIG. 1, a process condensate stream from a chemical production plant is fed via line 2 to an entry port 4 in the midsection of an upright cylindrical tower 6 having a closed top and bottom. Tower 6 comprises a lower stripping section 8 and an upper rectification section 10. The tower is of conventional construction, preferably a countercurrent tower of the bubble-plate or packed type operable at relatively low pressures ranging generally from 0 psia to 300 psig and most preferably ranging from about 25 psig to 100 psig. The packed sections may utilize packing materials supported by perforated grid or trays.
Although any low pressure relatively inert stripping fluid is considered suitable for purposes of this invention, it is suggested to use upwardly flowing steam as the stripping gas. Steam may be supplied under low pressure through a line 12 to the tube side of a reboiler 14 generating steam that is delivered to the base of the tower via line 16. Alternately, the steam may be directly injected into the base of tower 6 (not shown).
Upon entering port 4, the process condensate flows downwardly through stripping section 8 and at least a portion of the contaminants are stripped from the condensate by steam vapor rising countercurrently through this section. The stripped condensate collected at the closed bottom of tower 6 flows to the shell side of reboiler 14 by means of line 18 and is vaporized generating steam flow to the tower via line 16. The portion of the bottoms liquid not vaporized is withdrawn from the reboiler by means of a bottoms pump 20 and is discharged along line 22 for use in various stages of chemical production. For example, the bottoms liquid of reduced Contaminant content may be used as boiler feed water make-up. Alternatively, the stripped condensate can be used for cooling tower water make-up or may be directly discharged under permit into the municipal sewer system or local waterways with little or no further treatment.
The stripped contaminates in vapor pass upwardly within the tower 6 through rectification section 10. Some of the vapor is recondensed during rectification and flows downwardly within the tower to the stripping section 8 below. The remaining vapor is withdrawn from the top of tower 6 as a concentrated overhead stream. The overhead is delivered along line 24 to condenser 26 whereby the overhead is totally condensed and subcooled. Suitable condensers include, but not by way of limitation, heat exchangers, water coolers and/or air fin coolers for purposes of this invention.
The condensate is then transferred along line 28 to overhead receiver 30 which is preferably a pressure vessel receiver such as that kind conforming with ASME standards. Traces of non-condensables such as dissolved hydrogen gases, for example, may be vented from receiver 30 to the atmosphere along line 32. During start-up of the treatment process, the condensed overhead stream is withdrawn from receiver 30 along line 34 via reflux pump 36 whereby all of the condensed overhead is returned along line 38 as reflux to the top of tower 6. Although any conventional pump may be used for this purposes, an ANSI standard end suction vertical centerline discharge pump such as that available from Goulds Pumps, Inc. out of Seneca Falls, N.Y. or that offered under the tradename Durco™ from The Duriron Company Inc. out of Dayton, Ohio is considered particularly suited to this invention.
Once the contaminates reach concentrated levels within the condensed stream, preferably comparable to about a 30 to 200 fold increase in concentration over that amount in the process condensate fed to the tower along line 2, the condensed overhead stream is split such that a portion of the stream is withdrawn along line 40 at a controlled rate to provide a withdrawn stream of much greater contaminant concentration than the condensate feed. Note that this level of concentration in the withdrawn stream is about 5 to 15 times greater than it is in the overhead vapor from a process condensate stripper with no rectification. To meet this objective, the split stream is generally withdrawn at a controlled rate ranging from 3 and up to about 50% by volume of the total condensed stream. Preferably, the condensate will be withdrawn along line 40 at a rate of about 5 to 20% and most preferably about 10 to 15% by volume of the total stream so as to correspond to a reflux ratio ranging anywhere from 6:1 to 10:1 reflux to withdrawn condensate.
In this manner, the concentration level of the contaminants in the withdrawn stream is so high (having a reduced overall liquid volume) such that the thermal load transferred to the plant upon injection of the withdrawn steam back into the production plant is relatively minor in comparison to what it would be if the stripping tower overhead were totally condensed and injected directly into the plant without concentration (i.e. rectification). The withdrawn concentrated overhead is then recycled back into the plant along line 40 via injection pump 42 at the appropriate stage of the plant's operation so that the contaminants may be decomposed, reused and/or recycled for the production of chemical product.
In an alternative embodiment as shown in FIG. 2, the stripping and rectification steps of the present invention are conducted in two separate columns presented in series. In this embodiment, the process condensate is first introduced along entry port 4 to the top of stripping column 108 and later rectified in separate rectification column 110. Each column 108 & 110 is made of conventional construction as heretofore described preferably being of the cylindrical countercurrent bubble-plate or packed type and operable at relatively low pressure. This embodiment is particularly well adapted for use in retrofitting existing low pressure steam stripping operations wherein the stripping tower is relatively small such that a rectification section cannot be fitted within the existing tower.
As in the first embodiment, steam may be supplied under low pressure to the stripping column 108 through a line 12 to the tube side of a reboiler 14 vaporizing water generating steam that flows to the base of the column via line 16. Alternately, the steam may be directly injected into the base of tower 6 (not shown). Upon entering port 4, the process condensate flows downwardly through stripping column 108 and at least a portion of the contaminants are stripped from the condensate by the steam vapor rising countercurrently through the column. The stripped condensate collected at the closed bottom of tower 6 flows to the shell side of reboiler 14 by means of line 18 where it is vaporized to steam that flows to the tower via line 16. The portion of the bottoms liquid not vaporized is withdrawn from the reboiler by means of a bottoms pump 20 which and is discharged along line 22 for use in various stages of the production facilities.
The contaminant-rich vapor overhead from stripping column 108 is then supplied via line 109 to the base portion of rectification column 110. Some of the vapor is condensed during rectification and, along with reflux, subsequently flows downwardly through the column 110 to provide a bottoms liquid. The bottoms liquid is withdrawn through a line 112 via pump 114 for delivery to the top of stripping column 108 for additional stripping action. The remaining vapor is withdrawn along line 24 as a concentrated stream for subsequent condensation and use as more fully described above in conjunction with the first embodiment.
Another embodiment of the invention is specifically directed to use of the present apparatus and method of using the same for treating ammonia plant process condensate. In this embodiment, the process condensate generally comprises condensate from the reforming stages of ammonia production, water formed in CO shift converters, and secondary condensate recovered from carbon dioxide stripping operations within the plant such as from a Benfield hot potassium carbonate CO 2 removal system. The process condensate will include ammonia in an amount ranging anywhere from 500 to 2,000 parts per million (ppm) by weight of the condensate, methanol in amounts ranging from about 100 to 800 ppm by weight of the condensate, as well as trace amounts of other by-products, raw materials and impurities such as alkylamines and dissolved nitrogen and hydrogen gas. The process condensate may be utilized for purposes of this invention at its recovery temperature (recovery from the plant) which generally ranges from 150° to 250° F. and is most preferably at a temperature near the bubble point of the condensate for the tower operation pressure.
Looking to FIG. 3, the ammonia plant process condensate is fed via line 2 to an entry port 4 in the midsection of an upright cylindrical tower 6 comprising a lower stripping section 8 and an upper rectification section 10. The tower is of conventional construction as heretofore described in the first embodiment operable at relatively low pressures ranging generally from 0 psia to 300 psig and most preferably ranging from about 10 to 100 psig. Steam is supplied under low pressure through a line 12 to the tube side of a reboiler 14 with flow to the reboiler being controlled by flow control valve 115 generating steam in the reboiler which is delivered to the base of the tower via line 16.
Upon entering port 4, the process condensate flows downwardly through stripping section 8 and the contaminants are stripped from the condensate by steam vapor rising countercurrently through this section. The stripped condensate collected at the closed bottom of tower 6 flows to the shell side of reboiler 14 by means of line 18 and is vaporized generating steam to the tower via line 16. A portion of the bottoms liquid is withdrawn from the reboiler controlled by a level control valve 118 by means of a bottoms pump 20 which and is discharged along line 22 for use as boiler feed water make-up or cooling tower water make-up in the ammonia plant.
The stripped contaminate-rich vapor passes upwardly within the tower through rectification section 10. Some of the vapor is recondensed during rectification and flows downwardly within the tower to the stripping section 8 below. The remaining vapor is withdrawn from the top of tower 6 as a concentrated overhead stream. During initial start-up of the system, the overhead from tower 6 is diverted along line 120 and vented to the atmosphere until the pressure and composition of the overhead stream approach design conditions within the rectification section 10 of tower 6. This pressure is controlled by pressure controller 122 which is connected to valves 124 and valves 126 such that until equilibrium is reached, the overhead will flow along line 120 with flow via line 24 to the condenser blocked by valve 128. Once equilibrium is reached, line 120 is closed and line 24 opened.
The overhead is then delivered along line 24 to first condenser 26a whereby the overhead stream is totally condensed. First condenser 26a is in the form of a heat exchanger, wherein the preferred coolant is a dilute solution of ammonium nitrate which upon heating will then be delivered to a concentrator (not shown) in the ammonia plant. A complete description of such a concentrator system appears in Holiday, System Curbs Nitrogen in Plant-Effluent Streams, CHEMICAL ENGINEERING (Aug. 14, 1978) incorporated herein by reference. In this embodiment, the waste water stream from the concentrator is thus used for heat exchange with the tower overhead stream and the heated cooling water is then recycled along line 130 back to the concentrator for reuse. Although direct heat exchange is contemplated for use in this embodiment, indirect heat exchange is deemed suitable for these purposes and may be advisable in certain circumstance to eliminate the risk of leakage of the waste water stream into the overhead stream. An indirect heat transfer system would of course require additional equipment such as an additional holding tank, fluid pump and heat exchanger.
It should be understood that the cooling fluid stream of the heat exchanger could have its source in any number of plant operations, whereby the heated stream may be returned for recycled use in the plant. Alternately, cooling tower water can be used in the heat exchangers to condense the overhead. In another alternate condensing mode, an air fin condenser could be used.
After condensing, the condensate is directed along line 132 and is further subcooled to reduce the vapor pressure in trim cooler 26b preferably to a temperature ranging from 100° to 150° F. with a vapor pressure ranging from 2 to 8 psia. The subcooled condensate is then directed along line 28 to receiver 30 wherein normally closed valve 134 may be opened to allow traces of non-condensables in the condensed overhead to be vented to the atmosphere. This valve may be operated manually or by monitoring the pressure within the receiver. The condensate is withdrawn from the receiver 30 in conjunction with level control valve 136 at a rate corresponding with the level of fluid collected within the receiver.
In the embodiment shown in FIG. 3, a meter 138 is provided along line 34 to monitor the content of the condensed overhead stream as it exits the overhead receiver 30 to assure that the condensed stream is free of any unwanted contaminates. For example, ammonium nitrate contained in the heat exchanger loop described above could potentially leak into the stream during heat exchange. The presence of such ammonium nitrate could be detrimental to the operation of the ammonia plant if recycled to the plant as is contemplated by this invention. Thus a meter of any type deemed suitable for purposes of recognizing unwanted contaminates is connected to diversion valve 140 which is normally closed. Should any unwanted contaminates be present in the condensed stream, the stream will automatically stop feeding line 40 and instead be diverted along line 142 to a sump or other waste containment region. In this manner, the integrity of the ammonia plant process is not in any way jeopardized by the injection of the condensed stream into the ammonia plant. In a preferred embodiment, when the heat exchanger coolant above is provided from the ammonia plant concentrator, meter 138 is an ion specific electrode for nitrate.
Initially, all of the condensed overhead withdrawn from receiver 30 is returned to the top of tower 6 as reflux until the contaminates reach concentrated levels within the condensed stream, preferably comparable to about a five to fifteen fold increase in concentration over that amount of contaminants that would be in a conventional stripper overhead steam vent. This concentration is about 40 to 120 times greater than in the process condensate feed to the tower. The condensed overhead stream is then split such that a portion of the stream is withdrawn along line 40 preferably at a rate of about 5 to 20% and most preferably about 10 to 15% by volume of the total stream so as to correspond to a reflux ratio ranging anywhere from 6:1 to 10:1 reflux to withdrawn condensate. As is shown in Table I below, in a most preferred embodiment of the invention, the condensed stream is withdrawn at a reflux rate of about 8:1 reflux to withdrawn condensate.
The withdrawn concentrated overhead is then recycled back into the ammonia plant along line 40 via injection pump 42 at different stages of the ammonia production operation. Although it should be understood that the concentrated overhead stream may be utilized in any manner deemed suitable, in one embodiment of the invention the concentrated stream is fed along line 40 and injected to the gas and steam mixed feed coil of the primary reformer or to the air preheat coil of the secondary reformer of the plant. In any event, in order to eliminate any pressure penalties on the ammonia plant, the concentrated stream should be injected back into the plant under pressures on the order of 500 to 600 psi, or to any other pressure equivalent to the pressure of the stream in which it is placed.
For these purposes, injection pump 42 is preferably a high differential pressure positive displacement reciprocating pump having a variable frequency motor such those manufactured by Union Pump Company out of Michigan, Wilson Snyder Pumps out of Texas or Milton Roy Co. out of Pennsylvania. These pumps are preferred to assure that the condensed overhead is efficiently withdrawn at a relatively low rate in accordance with the present invention, and delivered to the ammonia feed coil at relatively high pressures. Of course a high speed centrifugal pump could also be used for purposes of this invention, but may be less efficient in view of the low rate of withdrawal required.
It should be understood that during the practice of this invention, various systems and apparatus can be employed to monitor and control the rate of flow of the processed streams and the temperature and vapor pressure of these streams. Such control systems may be based upon a valve operations as shown in FIG. 3 hereof, by computer calculations and/or manual adjustments.
The apparatus used for purposes of the invention may generally be comprised of any relatively chemically inert, durable materials such as carbon steel, stainless steel, certain polymers and metal alloys known in the art. It should be understood that the apparatus including the towers, pumps, condensers, valves, receivers, and boilers are conventional and may be generally dimensioned to meet that task at hand taking into consideration the volume of vapor and liquid flow being processed and size of the ammonia processing plant.
TABLE I__________________________________________________________________________EXAMPLE MATERIAL BALANCE OF AN OPERATING CONDITIONUSING THE APPARATUS CONFIGURATION OF FIG. 3 A B C D E F__________________________________________________________________________Water, Lbs/Hr 149,740 32,700 24,676.29 21,934.48 2,741.81 146,998.19Ammonia, Lbs/Hr 225 2,023.65 1,798.80 224.85 0.15Methanol, Lbs/Hr 35 300.06 266.72 33.34 1.66Total, Lbs/Hr 150,000 32,700 27,000 24,000 3,000 147,000Pressure, PSIG 28 50 29 60 650 30Temp, °F. 238 297 234 120 120 274__________________________________________________________________________
TABLE II______________________________________PERFORMANCE FOR VARIED OVERHEADWITHDRAWAL RATES CALCULATED FORAPPARATUS CONFIGURATION OF FIG. 3______________________________________Overhead Withdrawal Rate #/Hr.sup.1 3000 917Reflux Ratio 8.0 27.5NH.sub.3 in Withdrawn Overhead 7.5 24.5MeOH in Withdrawn Overhead 1.1 3.6NH.sub.3 in Bottoms, ppm.sup.2 1.0 1.75MeOH in Bottom, ppm.sup.2 11.3 14.1% of Flood 80 80Theoretical Stages 12 12______________________________________ .sup.1 Pumped to ammonia plant (stream E in FIG. 3) .sup.2 Concentrations in stripped condensate (stream F in FIG. 3)
The invention is further illustrated by the following example which is illustrative of certain embodiments designed to teach those of ordinary skill in the art how to practice the invention, and to represent the best mode contemplated for carrying out this invention.
EXAMPLE 1
RETROFITTING EXISTING LOW PRESSURE STRIPPING OPERATION
A conventional low pressure stripping system for treating process condensate from an ammonia plant was retrofitted in accordance with the present invention. The existing system comprised a stripping tower of a carbon steel column design by Chemical Construction Company, having an internal design pressure of 155 psig at 450° and being 5' 6"in diameter by 54'by 10"tangent to tangent for condensate stripping. The tower was packed with two sections of one inch Flexirings™ packing, a product of Koch Engineering Company out of Wichita, Kansas, wherein the bottom packed section of the tower had 20'depth and the top packed section was 18'2"in depth. Other tower internals including packing bed supports, liquid distributors, packing hold downs and demisters. A used kettle type reboiler was placed into service to indirectly provide stripping steam. The column boil up rate was controlled by steam to the reboiler on flow control. Column pressure control was by a pressure control valve on the overhead vapor. The overhead vapor containing steam, ammonia, methanol, and traces of alkylamines was vented to the atmosphere.
The stripping tower was revamped in accordance with the process calculations for the hydraulic loads appearing in Tables I and II above indicating that twelve theoretical stages were required to accomplish the flow sheet separation with the reflux ratio desired. Approximately two stages were needed in the enriching rectification section and ten were deemed required in the stripping section. The height equivalent to a theoretical stage or plate, HETP, was calculated to be about 2.5 to 3.0 feet based on actual column process performance data with one inch Flexirings™ in a stripping configuration. This resulted in a retro-fit process design of 30' of one inch Flexirings™ in the stripping section and 6' 3" of one inch Flexirings™ in the rectification section. A redistributor was located midway in the depth of the stripping section.
The tower was modified for process condensate feed at the top of the stripping section (column midsection) and reflux to the top of the rectifying section. One inch Flexirings™ were used for tower packing and the internals of the columns were provided by Koch Engineering. These internals include packing supports, liquid feed distributors, hold downs, redistributors, and demister. Equivalent packing is also available such as ballast rings by Glitch or High-Pack™ Packing by Norton.
The reboiler and steam control method remained unchanged when revamping from stripping only to combination rectification-stripping. Steam rate to the reboiler and the revamped stripper rectifier configuration remains essentially the same as it was in a stripping only configuration.
From the foregoing it should be understood that this invention is one well adapted to attain all ends and objects herebefore set forth together with the other advantages which are obvious and which are inherent to the structures and apparatus.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other feature and subcombinations. This is contemplated by and is within the scope of the amended claims.
Since many possible embodiments may be made of the invention without departing from he scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawing is to be interpreted as illustrative and no in a limiting sense.
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An apparatus and method for treating chemical production plant process condensate such that a contaminant-rich stream and a relatively pure aqueous stream is separately recoverable from the condensate, wherein the contaminants are substantially removed from the condensate by steam stripping and subsequent rectification in a relatively low pressure stripping/rectification tower. The tower overhead is then condensed with a portion of the condensed overhead being returned to the top of the rectification section of the tower as reflux and the balance being withdrawn as a concentrated stream for reuse in the plant. In a second embodiment, separate stripping and rectification towers operate in series whereby the overhead of the stripping tower is delivered to the lower section of the rectification tower and the rectification bottoms are returned to the top of the stripping tower. The overhead from the rectification tower is then condensed with a portion returned at its top for reflux and the remainder being withdrawn as a highly concentrated stream for recycling to the ammonia plant. The mass flow to the ammonia plant is low enough because of high concentration that ammonia plant modifications are not needed nor is there significant thermal impact. The apparatus may be used in conjunction with existing low pressure equipment, avoiding costly major modifications.
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BACKGROUND
1. Technical Field
The present disclosure relates to air conditioning systems, and particularly to an air conditioning system used in a vehicle.
2. Description of Related Art
Air conditioning systems (A/C systems) are well known in the art, operating on the principle of evaporation and condensation to provide cooled air in indoor areas, including vehicle interiors.
Often, vehicle A/C systems can be manually switched between a ventilation mode, in which an inside air inlet is closed and an outside air inlet opened, drawing fresh air into the interior of the vehicle, and recirculation mode, in which the inside air inlet is opened and the outside inlet closed, recirculating air within the interior of the vehicle.
However, in city driving, exterior air quality is often poor, especially in conditions of heavy traffic. If ventilation mode is utilized, air introduced to the vehicle interior can easily contain numerous contaminants such as vehicle exhaust emissions. While the emissions can be routed through a filtering system, net effect is often less than ideal, resulting in an unpleasant environment being created inside the vehicle.
Thus, an air conditioning system providing reliable exclusion of exhaust emission from other vehicles or the user's vehicle, a method of operating the system, and a vehicle using the air conditioning system, are desired.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of two vehicles with air conditioning systems in accordance with an exemplary embodiment.
FIG. 2 is a block diagram of the two vehicles with air conditioning systems of FIG. 1 .
FIG. 3 is a detailed block diagram of the air conditioning system of FIG. 1 in accordance with a first embodiment.
FIG. 4 is a detailed block diagram of the air conditioning system of FIG. 1 in accordance with a second embodiment.
FIG. 5 is a flowchart of a method implemented by the air conditioning system for preventing intake of emissions in accordance with a first embodiment.
FIG. 6 is a flowchart illustrating a method implemented by the air conditioning system for preventing intake of emissions in accordance with a second embodiment.
DETAILED DESCRIPTION
Referring to FIG. 1 and FIG. 2 , a first vehicle 20 and a second vehicle 30 are illustrated. The first vehicle 20 includes a detection device 22 and an air conditioning system 24 . The detection device 22 is located in a front end of the first vehicle 20 , and determines whether another vehicle, such as the second vehicle 30 , is within a predetermined distance of the first vehicle 20 . The detection device 22 may be an ultrasonic transducer or a video camera. The predetermined distance is preset to, for example, two or three meters (m), and is fully adjustable according to preference. When the second vehicle 30 is determined to be within the predetermined distance, the detection device 22 alerts the air conditioning system 24 by transmission of a signal thereto.
The air conditioning system 24 is installed in the first vehicle 20 , electrically coupled to the detection device 22 . The air conditioning system 24 operates between ventilation and recirculation modes. In ventilation mode, an inside air inlet is closed and an outside air inlet is opened, drawing fresh air into the interior of the vehicle 20 , and in recirculation mode, the inside air inlet is opened and the outside inlet closed, to recirculate air inside the interior of the first vehicle 20 .
The air conditioning system 24 switches to recirculation mode in response to the signal received from the detection device 22 . When no signal has been received from the detection device 22 , the air conditioning system 24 switches/remains in the ventilation mode.
FIG. 3 is a detailed block diagram of the air conditioning system 24 . The air conditioning system 24 includes a control module 242 , a selection module 244 , and an air adjusting module 246 . The control module 242 directs the selection module 244 to select an operating mode for the air adjusting module 246 . When the signal is received from the detection device 22 , the control module 242 directs the selection module 244 to select the recirculation mode from the air adjusting module 246 . When no signal is received from the detection device 22 , the control module 242 directs the selection module 244 to select the ventilation mode for the air adjusting module 246 .
Referring to FIG. 4 , in a second embodiment, the air conditioning system 24 can further include a timing module 248 . The timing module 248 , which may be a timer, triggers the control module 242 to determine if the signal is incoming from the detection device 22 in a predetermined time interval, such as two minutes or three minutes. If, after the predetermined time interval, no signal is incoming from the detection device 22 , the control module 242 directs the selection module 244 to select the ventilation mode for the air adjusting module 246 .
As described, the first vehicle 20 automatically switches to the recirculation mode when the second vehicle 30 is detected within a predetermined distance. Thus, emissions discharged from the second vehicle 30 are prevented from being drawn into the inside of the first vehicle 20 .
Referring to FIG. 5 , a method 400 of operating an air conditioning system according to a first embodiment is illustrated. The method 400 includes the following steps.
In step S 402 , the detection device 22 determines whether a second vehicle 30 is within a predetermined distance of the first vehicle 20 . If so, step S 404 is implemented. If not, the first step S 402 is repeated.
In step S 404 , the detection device 22 sends a signal to the air conditioning system 24 indicating the second vehicle 30 is within the predetermined distance.
In step S 406 , the air conditioning system 24 switches to the recirculation mode.
Referring to FIG. 6 , a method 500 of operating an air conditioning system according to a second embodiment is shown. The method 500 includes the following steps.
In step S 502 , the detection device 22 determines whether a second vehicle 30 is within a predetermined distance of the first vehicle 20 . If so, step S 504 is implemented. If not, step S 512 is repeated.
In step S 504 , the detection device 22 sends a signal to the air conditioning system 24 indicating that the vehicle 30 is within the predetermined distance.
In step S 506 , the first vehicle 20 determines whether the air conditioning system 24 is currently in the recirculation mode. If so, step S 510 is implemented. If not, step S 508 is implemented.
In step S 508 , the air conditioning system 24 switches to the recirculation mode.
In step S 510 , the air conditioning system 24 determines whether a signal is incoming from the detection device 22 after a predetermined time interval. If so, the procedure finishes. If not, step S 512 is implemented.
In step S 512 , the air conditioning system 24 switches to the ventilation mode.
According to the methods disclosed, the air conditioning system 24 of the vehicle 20 switches to the recirculation mode when the vehicle 30 is determined to be within the predetermined distance. Thus, the emissions discharged from the vehicle 30 are prevented from being drawn into the interior of the vehicle 20 .
It is believed that the embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
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An air conditioning system providing cooled air to a vehicle includes a detection device, a control module, and an air adjusting module. The detection device determines whether another vehicle is in front of the vehicle within a predetermined distance, and sends a signal when the other vehicle is detected. The control module is coupled to the detection device and controls the air adjusting module to operate in a recirculation mode upon receiving the signal.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a driving apparatus for a recording medium by which the moving speed of a recording medium relative to a pickup is kept constant. More particularly, this invention relates to a driving apparatus for a recording medium which is suitable for use with, for example, an optical compact disc player.
2. Description of the Prior Art
In the optical compact disc, by way of example, a signal is generally recorded on the disc as a spiral track from the inner periphery of the disc to its outer periphery at the constant linear velocity. Therefore, when such optical compact disc is reproduced, a servo has to be applied for the disc rotation so that the disc is rotated at the same constant linear velocity as that upon recording.
In that case, it has been proposed that a distance between the reproducing position of, for example, a pickup and the center of the disc is detected, the rotation speed of the disc is measured by calculating the detected distance and thereby the servo is applied to the disc rotation on the basis of the measured rotation speed. This previously proposed method, however, urges the calculating circuit and so on to be complicated, and also the servo accuracy is not so high.
By the way, in the recording of the compact disc, the coding according to the so-called run length limited code system is generally employed in which the minimum and maximum numbers of a series of, for example, "0"s are determined, and in which such a pattern in which "0" continues at maximum (for example, 11) exists without failure at every predetermined period as a frame synchronizing signal.
Accordingly, the present inventor has previously proposed the servo circuit as shown in FIG. 1. As shown in FIG. 1, a signal reproduced from a disc (not shown) by a photodetector 1 is suppled to a waveform converting circuit 2 and then to a differentiating circuit 3 from which is reproduced the signal which corresponds to "0" or "1". This reproduced signal is supplied to a first fixed contact A of a selector circuit 4. The signal from the differentiating circuit 3 is also supplied to a synchronizing separating circuit 5. The synchronizing separating circuit 5 includes a PLL (phase locked loop) in which a frame synchronizing signal is separated in synchronism with the clock signal in the reproduced signal, while the lock range of the PLL is made narrow and the indicating signal of "0" is delivered when the PLL is not locked. The frame synchronizing signal thus separated is supplied to a second fixed contact B of the selector circuit 4. Further, there is provided a reference clock generator 6. This reference clock generator 6 generates a reference clock signal with the frequency same as the clock signal (for example, 2.16 MHz) in the reproduced signal when the predetermined servo is made effective. This reference clock signal is supplied to a frequency dividing circuit 7 which produces a signal corresponding to four frame synchronizing signals (four frames). This signal is supplied to a third fixed contact C of the selector circuit 4.
The indicating signal indicative of the locked state of the PLL from the synchronizing separating circuit 5 is supplied to the selector circuit 4 as its control signal so that a movable contact D of the selector circuit 4 is connected to the fixed contact A during the period through which this indicating signal is "0". Usually, the movable contact D of the selector circuit 4 is connected to its fixed contact B. The signal from the selector circuit 4 is supplied to a reset terminal of a counter 8, while the clock signal from the clock generator 6 is supplied to the count terminal of the counter 8.
When the continuous number of "0" in the frame sychronizing signal is for example, 11, the output regarding the count value [8] from the counter 8 is supplied to a NAND circuit 9. Also, the output regarding the count value [2] from the counter 8 is supplied to the NAND circuit 9 through a delay circuit 10. Thus, the NAND circuit 9 normally generates an output "1", and at a time point corresponding to a time point when the counter valve becomes [11] after a predetermined delay time since the count value has become [10], the output of the NAND circuit 9 becomes "0". The output signal from the NAND circuit 9 is supplied to the enable terminal of the counter 8 so that the output of the counter 8 is fixed to the count value [11]. The output from the NAND circuit 9 is also supplied to the selector circuit 4 as its control signal so that in the period during which this signal is " 0" the movable contact D of the selector circuit 4 is connected to the fixed contact C.
Further, the output from the NAND circuit 9 is supplied through an inverter 11, a low-pass filter 12 and a resistor 13 to an inverter 14.
The clock signal from the clock generator 6 is supplied to a frequency dividing circuit 15 which then generates a reference frame synchronizing signal. This reference frame synchronizing signal and the reproduced frame synchronizing signal from the synchronizing separating circuit 5 are fed to a flip-flop circuit 16 which then generates an output corresponding to the phase difference therebetween. This output is supplied through a NAND circuit 17, a low-pass filter 18 and a resistor 19 to the inverter 14.
Thus from the inverter 14 is derived the output corresponding to the period in which the output from the counter 8 is [11] and corresponding to the phase difference between the reference frame synchronizing signal and the reproduced frame synchronizing signal.
The output from the inverter 14 is supplied to a NAND circuit 20 and the lock indicating output from the synchronizing separating circuit 5 is supplied to the NAND circuit 20. The output from the NAND circuit 20 is supplied to the bases of an npn transistor 21 and a pnp transistor 22, while the output from the inverter 14 is supplied to the bases of an npn transistor 23 and an pnp transistor 24. The collectors of the transistors 21 and 23 are connected together to a voltage source terminal V cc , while the collectors of the transistors 22 and 24 are together grounded. Further, the emitters of the transistors 21 and 22 are connected together, while the emitters of the transistors 23 and 24 are connected together. A spindle motor 25 for rotating a disc is connected between the above emitter connection points.
With this circuitry, until the PLL in the synchronizing separating circuit 5 is locked, the signal "0" is supplied to the NAND circuit 20 and hence the output from the NAND circuit 20 is "1" so that the transistor 21 is turned on but the transistor 22 is turned off. At that time, since the movable contact D of the selector circuit 4 is connected to the fixed contact A, the reproduced signal is directly supplied to the counter 8. As a result, when the disc rotation is slow and the signal is dull, the count value of the counter 8 quickly becomes [11] so that the output from the NAND circuit 9 becomes "0". By this output, the counter 8 is stopped and the selector circuit 4 is changed in position or its movable contact D is connected to the fixed contact C so that the counter 8 is stopped for four frame periods. Since the output from the NAND circuit 9 is "0", the output from the inverter 14 becomes "0". Thus, the transistor 23 is turned off and the transistor 24 is turned on to thereby allow a current to flow through the spindle motor 25 in the arrow direction, thus increasing the rotation speed of the spindle motor 25.
In consequence, the rotation speed of the disc is being continuously increased until the maximum interval of the signals becomes approximately 11 clocks.
At that time, the PLL in the synchronizing separating circuit 5 is locked, the selector circuit 4 is changed in position or its movable contact D is connected to the fixed contact B and the signal "1" is supplied to the NAND circuit 20. As a result, the separated frame synchronizing signal is supplied to the counter 8. When the length of the synchronizing signal reaches more than 11 clocks, the output of the NAND circuit 9 becomes "0"during four frame periods, the output from the inverter 14 becomes "0", the output from the NAND circuit 20 becomes "1" so that the transistors 21 and 24 are turned on and the transistors 22 and 23 are turned off to thereby allow the current to flow through the spindle motor 25 in the arrow direction. Therefore, the rotation speed thereof becomes high. On the other hand, when the length of the synchronizing signal becomes less than 11 clocks, the output from the NAND circuit 9 becomes "1", the output from the inverter 14 becomes "1" and the output from the NAND circuit 20 becomes "0" so that the transistors 21 and 24 are turned off and the transistors 22 and 23 are turned on to thereby allow the current to flow through the spindle motor 25 in the direction counter to the arrow direction, thus lowering the rotation speed thereof.
As a result, the rotation speed servo is applied to the disc so as to make the length of the synchronizing signal equal to 11 clocks.
At that time, the flip-flop circuit 16 produces the output signal which becomes "1" during the period from the reproduced synchronizing signal to the reference synchronizing signal and "0" during the period from the reference synchronizing signal to the succeeding reproduced synchronizing signal. For this reason, when the reproduced synchronizing signal gets behind the position at which the phase difference between the reproduced synchronizing signal and the reference synchronizing signal is 180°, the period during which the signal is "0" becomes long, while when the reproduced synchronizing signal goes ahead of that position, the period during which the signal is "1" becomes long. And, when the signal is "0", the output from the NAND circuit 17 becomes "1", the output from the inverter 14 becomes "0" and the output from the NAND circuit 20 becomes "1", thus the rotation speed of the spindle motor 25 is raised. Conversely, when the signal is "1", the rotation speed of the spindle motor 25 is lowered.
As a result, the rotation phase servo is applied to the disc so as to make the synchronizing signal at the predetermined position.
As described above, the rotation speed servo of the constant linear velocity and the rotation phase servo are applied to the disc. In this case, since the pull-in of the rotation speed of the disc at the beginning is carried out also by the use of the counter 8, the pull-in operation of the speed can be made by a simple circuitry.
In the case of such previously proposed servo circuit, however, since the rotation speed servo is performed by detecting the length (11 clocks) of the synchronizing signal with the clock signal, the accuracy of the rotation speed servo becomes as significantly rough as 1/11.
If in the phase servo system, by way of example, the frame synchronizing signal is multiplied and the phase servo is made effective with the frequency (for example, 7.35 kHz) higher than that of the inherent frame synchronizing signal, the accuracy of the speed servo has to be raised. In that case, the above rough servo can not raise the frequency of the phase servo and hence the superior servo can not be carried out.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a driving apparatus for a recording medium which can perform the speed servo with quite high accuracy by simple circuitry.
It is another object of the present invention to provide a driving apparatus for a recording medium which can perform the superior phase servo by simple circuitry.
It is a further object of the present invention to provide a driving apparatus for a recording medium which can prevent the erroneous rotation from being made when a dropout occurs in a reproduced signal.
It is a still further object of the present invention to provide a driving apparatus for a recording medium which is suitable for use with an optical compact disc player.
According to one aspect of the present invention, there is provided a driving apparatus for a recording medium comprising:
a motor for driving a recording medium;
a preset counter for counting a reference synchronizing clock signal and being reset by a synchronizing signal in a reproduced signal; and
a circuit for producing an analog electrical signal corresponding to a time interval from a time when a count value of said preset counter reaches its preset value to a reset time of said preset counter; wherein said motor is controlled by said analog electrical signal such that moving speed of said recording medium relative to a pickup is made constant.
According to another aspect of the present invention, there is provided a driving apparatus for a recording medium comprising:
a motor for driving a recording medium;
a preset counter for counting a signal which is provided by multiplying a reproduced synchronizing signal and being reset by a reference synchronizing signal; and
a circuit for producing an analog electrical signal corresponding to a time interval from a time when a count value of said preset counter reaches its preset value to a reset time of said preset counter; wherein said motor is controlled by said analog electrical signal such that moving speed of said recording medium relative to a pickup is made constant.
The other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings through which the like reference designate the same elements and parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a systematic block diagram showing a conventional driving apparatus for a recording medium with a servo circuit;
FIG. 2 is a systematic block diagram showing an embodiment of the driving apparatus for a recording medium with a servo circuit according to the present invention;
FIGS. 3A to 3I are respectively waveform diagrams useful for the explanation thereof; and
FIG. 4 is a systematic block diagram showing another embodiment of the driving apparatus for a recording medium with a servo circuit according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, the driving apparatus for a recording medium with a servo circuit according to the present invention will hereinafter be described with reference to the attached drawings.
FIG. 2 is a systematic block diagram schematically showing the whole of such driving apparatus for a recording medium.
As shown in FIG. 2, in this embodiment of the invention, the signal from a differentiating circuit 3 is supplied to a retriggerable monostable multivibrator 30 having the inversion period of 11 clocks. The output from this monostable multivibrator 30 is supplied to a retriggerable monostable multivibrator 31 having the inversion period of 4 frames. The lock indicating signal from a synchronizing separating circuit 5 is supplied to the enable terminals of the respective monostable multivibrators 30 and 31.
In this case, until the synchronizing separating circuit 5 is locked, the monostable multivibrators 30 and 31 are being respectively set to the operation state. During this period, when the interval of "1" in the reproduced signal is more than 11 clocks, the multivibrator 30 is inverted and the multivibrator 31 generates the signal which is "1" during four frame periods. When the interval "1" in the reproduced signal becomes more than 11 clocks repeatedly, the output from the monostable multivibrator 31 becomes "1" continuously.
This signal is supplied through a resistor 32 to a comparing circuit 33.
The comparing circuit 33 is supplied with an arbitrary potential from a voltage dividing circuit 34. In this case, when the input signal is "1", the output from the comparing circuit 33 becomes also "1". The compared output therefrom is supplied to a NAND circuit 35 and also supplied through an inverter 36 to a NAND circuit 37. The outputs from the NAND circuits 35 and 37 are respectively supplied to the bases of the transistors 21, 22 and those of transistors 23, 24.
Therefore, during the period until the synchronizing separating circuit 5 is locked, when the other inputs of the NAND circuits 35 and 37 are normally "1" and the output from the monostable multivibrator 31 becomes "1", a current flows through a motor 25 in the arrow direction. Thus, the motor 25 is accelerated to make the disc rotation up to a predetermined speed and a so-called pull-in operation of the rotation speed iS carried out.
The synchronizing signal from the synchronizing separating circuit 5 is supplied through a NAND circuit 38 to the reset terminal of a counter 39. The lock indicating signal from the synchronizing separating circuit 5 is supplied to the NAND circuit 38. Further, the clock signal from the check signal generator 6 is supplied to the count terminal of the clock signal generator 6 through a NAND circuit 40.
When, for example, the clock frequency is 2.16 MHz and the frame frequency is 7.35 kHz, the outputs from the counter 39 regarding the count values [1], [32] and [256] are supplied to a NAND circuit 41. When the count value of the counter 39 becomes [289], the output from the NAND circuit 41 becomes "0". This output from the NAND circuit 41 is supplied to the NAND circuit 40. Thereafter, the supply of the clock signal is stopped and the output from the counter 39 is fixed to the counter value, [289].
Further, the output from the NAND circuit 41 is supplied through an inverter 42, an integrating circuit 43 and an amplifier 44 to a switching element 45. This switching element 45 is turned on by the output from the NAND circuit 38 and the signal through the switching element 45 when it is made on is supplied to a capacitor 46.
With this circuitry, when there exists the frame synchronizing signal as, for example, shown in FIG. 3A, the output from the inverter 42 becomes as shown in FIG. 3B. In this case, since
2.16 (MHz)÷7.35 (kHz)≈294
is established, the period during which the output from the inverter 42 becomes "1" is calculated as
294-289=5
thus being about 5 clock periods. During about 5 clock periods, the output signal "1" from the inverter 42 is supplied to the integrating circuit 43 which then forms a signal shown in FIG. 3C. This signal is sampled by the switching element 45 which is controlled by the output from the NAND circuit 38 and the sampled value is held in the capacitor 46 from which a peak value shown in FIG. 3D is derived. This peak value corresponds to the interval of the reproduced synchronizing signals, namely, the speed of the disc. In other words, when the rotation speed of the motor 25 is higher than a predetermined constant linear velocity, the period during which the output from the inverter 42 is "1" becomes short and hence the peak value from the capacitor 46 becomes low. Conversely, when the rotation speed of the motor 25 is higher than the predetermined constant linear velocity, the period during which the output from the inverter 42 is "1" becomes long with the result that the peak value from the capacitor 46 becomes high. This peak value from the capacitor 46 is supplied to the comparing circuit 33 through a resistor 47.
Moreover, the synchronizing signal from the synchronizing separating circuit 5 is supplied through a differentiating circuit 48 to the reset terminal of a flip-flop circuit 49. The reference synchronizing signal from the frequency dividing circuit 15 is supplied to a NAND circuit 50, which is also supplied with the lock indicating signal from the synchronizing separating circuit 5. The output from the NAND circuit 50 is supplied to the set terminal of the flip-flop circuit 49 through a differentiating circuit 51. And, the output from this flip-flop circuit 49 is supplied to an integrating circuit 52.
With this circuitry, when the reference synchronizing signal is as shown in FIG. 3E, if the synchronizing separating circuit 5 is locked, the flip-flop circuit 49 generates the signal shown in FIG. 3F. This signal is integrated to thereby form a signal 3G corresponding to the phase difference between the reproduced synchronizing signal shown in FIG. 3A and the reference synchronizing signal shown in FIG. 3E.
This integrated signal is supplied to the comparing circuit 33 through a resistor 54.
Thus, to the comparing ciruit 33 is supplied the signal shown in FIG. 3H, which signal results from adding the signal from the capacitor 46 to the signal from the integral circuit 52. This signal is compared with a reference level a (refer to FIG. 3H) determined by the voltage dividing circuit 34 in the comparing circuit 33 so that the comparing circuit 33 generates a signal shown in FIG. 3I which is pulse-width-modulated in correspondence with the rotation speed of the disc and the phase difference between the synchronizing signals.
Accordingly, in the period after the synchronizing separating circuit 5 is locked, when the other inputs to the NAND circuits 35 and 37 are ordinarily "1" and the output from the comparing circuit 33 becomes low potential, the current flows through the motor 25 in the arrow direction, while when the output from the comparing circuit 33 becomes high potential, the current in the direction opposite to the arrow direction flow through the motor 25 thus performing the speed servo and the phase servo for the disc rotation.
Moreover, the lock indicating signal from the synchronizing separating circuit 5 is supplied to the retriggerable monostable multivibrator 55 having the inversion period of, for example, 3 frames and the output therefrom is supplied to a NAND circuit 56. The lock indicating signal is also supplied through an inverter 57 to the NAND circuit 56. The output from this NAND circuit 56 is supplied to the other inputs of the NAND circuits 35 and 37.
With this circuitry, when normally the synchronizing separating circuit 5 is locked, the monostable multivibrator 55 is not inverted and the outputs from the multivibrator 55 and the inverter 57 are both "0"s. Thus, the output from the NAND circuit 56 becomes "1" and then is supplied to the other inputs of the NAND circuits 35 and 37. On the other hand, when a dropout occurs due to scratches and so on on the surface of the disc and the lock indicating signal is not generated from the synchronizing separating circuit 5, the monostable multivibrator 55 is inverted at the trailing edge of the lock indicating signal and the output therefrom becomes "1" and the output from the inverter 57 also becomes "1". Thus, the output from the NAND circuit 56 becomes "0". Thus, the outputs from the NAND circuits 35 and 37 are both fixed to "1"s so that the transistors 21 and 23 are turned on and the transistors 22 and 24 are turned off. Therefore, no current flows to the motor 25, and hence the motor 25 is rotated by only the moment of inertia. When the lock indicating signal is recovered or again generated from the synchronizing separating circuit 5, the output from the inverter 57 becomes "0" and the output from the NAND circuit 56 becomes "1". Further, when the lock indicating signal is continuously "0" over 3 frames at the start time of the motor 25 and due to dropout of long time, the output from the multivibrator 55 is returned to "0" and the output from the NAND circuit 56 becomes "1" so that the pull-in operation of the rotation speed is performed by the monostable multivibrator circuits 30 and 31.
Accordingly, when the normal reproduced signal is not obtained due to dropout and so on, the current flowing to the motor 25 is off and the servo can be prevented from being recklessly carried out by the incorrect signal. Also, when the servo is greatly displaced at the start of the motor and due to dropout of long time, the pull-in operation can be carried out.
As set forth above, the pull-in operation, the speed servo, the phase servo and the dropout treatment are carried out by the present invention. According to the circuitry thus made, the displacement of the servo relative to 289 clocks particularly in the speed servo is detected, the accuracy of the servo becomes quite high. Thus, even if the frequency of the phase servo is made high, no trouble occurs or superior servo can be carried out. The servo system used in the present invention is formed by the combination of the digital system employing the counter with the analog circuit system, so that as compared with the servo system the whole of which is performed by the digital circuit, the servo system according to the present invention can be simplified in circuit construction and manufactured at low cost. Moreover, since the servo circuit used in the present invention is of the digital system, it can hardly be affected by temperature characteristic and so on.
FIG. 4 is a block diagram showing another embodiment of the driving apparatus for a recording medium according to the present invention. In FIG. 4, like parts corresponding to those in FIG. 2 are marked with the same references and their detailed explanation will not be made for simplicity.
As shown in FIG. 4, the reference synchronizing signal from the frequency dividing circuit 15 is supplied through the NAND circuit 38 to the reset terminal of the counter 39, while the reproduced synchronizing signal from the synchronizing separating circuit 5 is supplied to a multiplying circuit 53 to produce a multiplied clock signal which is then supplied to the count terminal of the counter 39 through the NAND circuit 40. The output from the peak hold circuit is inverted in polarity by an operational amplifier 58. The synchronizing signal from the synchronizing separating circuit 5 is also supplied through the differentiating circuit 48 to the set terminal of the flip-flop circuit 49, while the output from the NAND circuit 50 is supplied to the reset terminal of the flip-flop circuit 49 through the differentiating circuit 51. Thus, the signal corresponding to a phase difference therebetween is obtained from the flip-flop circuit 49. This signal is inverted in polarity by the operational amplifier 58. Thus, the similar operation of that of the first embodiment shown in FIG. 2 can be carried out by the second embodiment shown in FIG. 4.
According to the present invention, the speed servo having high accuracy can be effected with a simple circuit construction.
The above description is given on the preferred embodiments of the invention, but it will be apparent that many modifications and variations could be effected by one skilled in the art without departing from the spirits or scope of the novel concepts of the invention, so that the scope of the invention should be determined by the appended claims only.
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A driving apparatus for a recording medium which includes a motor for driving a recording medium, a preset counter for counting either of a reference clock signal and a signal provided by multiplying a reproduced synchronizing signal, the preset counter being reset in response to a synchronizing signal in a reproduced signal when the reference clock signal is counted and being reset in response to a reference synchronizing signal when the signal which is provided by multiplying the reproduced synchronizing signal is counted, and a circuit for producing an analog electrical signal corresponding to a time interval during from a time when a count value of the preset counter reaches its preset value to a reset time of the preset counter, wherein the motor is so controlled by the analog electrical signal that the moving speed of the recording medium relative to a pickup is made constant.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 USC 119 of Swiss Patent Application No. 572/06 filed Apr. 7, 2006, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention is in the field of floor systems, in particular floor systems for conservatories and other extensions of buildings and/or small buildings according to the generic term of the independent patent claim.
BACKGROUND INFORMATION
[0003] In the domain of e.g. conservatories systems are known for which relatively extensive concrete foundations are required. This is correspondingly elaborate and costly. In this regard improved floor systems are now known from CH 695 736, in which only punctual foundations at the corners of the floor are required, such that only small areas need to be excavated. The floor system presented in this document additionally comprises a steel frame and a floor panel which is thermally and statically independent thereof. Thus thermal insulation of the floor is simplified and cracking fissuration due to different expansions is prevented.
[0004] This floor system, however, is disadvantageous in so far that excavations for concrete foundations are still necessary.
SUMMARY OF THE INVENTION
[0005] Starting from the described state of the art the object is to create a floor system, the installation of which involves no or only minor excavations.
[0006] This object is achieved by the invention as defined in the claims.
[0007] The invention is based on the replacement of concrete foundations by ground anchors. The ground anchors comprise anchoring elements by which the anchor is substantially retained in the ground, e.g. soil, essentially by means of positive engagement.
[0008] As the anchors may be driven into the ground, a preceding excavation is completely or at least largely unnecessary.
[0009] A further advantage of the use of ground anchors is that they do without a joining compound, such as e.g. concrete, cement etc.. Joining compounds require a certain time for desiccation or hardening respectively. This time can be saved. Furthermore conventional joining compounds are usually based on water and where necessary other bonding agents which may only be used within a certain temperature range. The working of concrete is e.g. not or only inadequately possible at temperatures below zero degrees Celsius. The floor system according to the invention may, however, due to the use of concrete anchors, be installed in any weather, in particular also under permafrost.
[0010] In a preferred embodiment, which comprises a panelled floor and a frame structure, said frame structure surrounding the panelled floor at least partly, no building materials containing water are used for the complete floor system including the panelled floor, such that the floor may be constructed in any weather, in particular also under permafrost.
[0011] The panelled floor of conventional floors comprises a concrete underlay, which is cast and desiccated before the floor panels are positioned. In a preferred embodiment the panelled floor is replaced by a dry construction system, which advantageously comprises prefabricated individual panels or a multi-layer prefabricated floor panel. Such a panel may e.g. be or comprise a dry concrete slab or a different kind of concrete bonded dry slab.
[0012] The construction of the system floor thus becomes largely independent of the prevailing ambient temperature conditions and in particular of those in the floor itself. In addition, excavation is restricted to a moderate depth for the frame construction and where necessary for the floor panel positioned in it.
[0013] A panelled floor or a floor panel respectively mainly serves statics over the complete floor and insulation and comprises a corresponding insulating layer. A floor panel is advantageously insulated thermally against the frame construction and surrounding soil.
[0014] The frame construction substantially replaces a frost barrier and is statically independent of the rest of the floor construction. Thus a cracking fissuration caused by different expansions in the panelled floor, in particular in a concrete slab can be prevented.
[0015] A frame construction is advantageously designed to be circumferential to a floor panel, whereas the frame construction is fastened to at least one ground anchor and where necessary to a wall. The floor system is particularly suited to building extensions such as e.g. conservatories and winter gardens, but also for individual small buildings such as tool sheds, aviaries etc.
BRIEF DESCRIPTION OF THE DRAWING
[0016] In the following exemplified embodiments are described in more detail by means of a drawing.
[0017] In the Figure an embodiment of the inventive floor system is shown.
DETAILED DESCRIPTION
[0018] In the Figure a section of a floor system with a frame construction 1 and a panelled floor is shown. The frame construction can be a circumferential steel frame. At the corners of the steel frame a ground anchor is fixed to, e.g. bolted or welded. The panel construction, which substantially consists of a multi-layer floor panel, is partially or completely framed by the frame construction 1 . In the present example the floor panel consists of the following layers: a profiled sheeting 3 (trapezoidal corrugations), a flat sheeting 4 , an insulation 5 , a multi-layer dry concrete slab 6 . The multi-layer dry concrete slab is a prefabricated dry concrete slab unit and in this example consists of two conjoined, advantageously bonded or glued together, individual dry concrete slabs. The individual concrete slabs are offset in relation to one another in order to enlarge a bonding surface and to restrict a possible formation of fissures in joining areas to one single layer.
[0019] Individual layers or slabs respectively may be attached to one another, especially by means of bolting or riveting. This is advantageous carried out prior to the fitting or installing of the dry floor system. For this purpose e.g. the profiled sheeting is joined to the flat sheeting. Such a joining of individual slabs as well as the manufacture of slab systems is carried out before construction of the floor system, such that a dry slab system is formed, which, together with the frame construction and the ground anchors, forms a dry construction system. An uppermost (multi-layer) dry concrete slab is advantageously not connected to other elements such as other slabs or the frame, but laid out in a floating manner. This guarantees decoupling between frame and concrete floor.
[0020] The insulation 5 is advantageously a slab of polyurethane foam of several centimeters thickness, advantageously 3-8 cm, e.g. 6 cm. The dry concrete slab 6 is of a preferred thickness in the region of 1.5-5 cm, e.g. 2-4 cm, e.g. 2.5 cm.
[0021] It is also possible to use a sandwich-slab as floor panel as described in CH No. 695 736, where profiled sheeting, insulation, and flat sheeting form the sandwich-slab, i.e. the insulation and the flat sheeting are interchanged in relation to the present construction. It is, however, self-evident that insulating and stabilizing layers and panels may be arranged in different manner and if appropriate supplemented by further layers and/or replaced by other suitable materials.
[0022] Between the steel frame and the floor panel another insulation (not shown in the figure) is advantageously inserted, e.g. an insulating strip of few millimeters to few centimeters thickness, e.g. 1 cm, to impede a thermal bridge. Furthermore a tolerance element 7 is loosely laid out on the steel frame, which tolerance element compensates tolerances e.g. of the floor, of the assemblies built onto the floor, e.g. a conservatory, and/or a building to which a conservatory is annexed. This kind of tolerance element is advantageously made of plastic or wood and additionally impedes a thermal bridge between frame and assembly.
[0023] The ground anchor 2 comprises two opposingly arranged anchoring elements 9 which are shovel-shaped or triangular. They are, with their wider side facing upwards, arranged laterally on a central tubular anchor element. These anchoring elements 9 retain the ground anchor in the soil and anchor the frame construction that is fixed to the ground anchor or to the several ground anchors and thus anchor the floor system. The ground anchor is advantageously made of metal, e.g. of steel and may, if required, also be fixed to a longitudinal side of the steel frame.
[0024] The anchoring elements may be arranged flexibly, such that, when positioning the ground anchor, e.g. by means of driving into the ground, e.g. into soil, they lie closely against the central elements and do not take up their strutted position until they have reached their final anchoring position. In a preferred embodiment of the ground anchor the anchoring elements are connected via a thread mechanism, e.g. a threaded rod, which leads through the central anchoring element, to the opposite ends of the anchor, which protrude out of the soil. A ground anchor is driven into the ground into a final position. Subsequently the anchoring elements are pressed outwards by means of the thread mechanism, so far that the ground anchor is anchored fast in the soil against traction.
[0025] Because an anchor even with its anchoring elements sticking out laterally, but in particular with its anchoring elements in resting position, demands a lot less spatial capacity than a concrete foundation, the excavation for the anchor with subsequent introduction of the anchor and filling up, excavation work is substantially less extensive.
[0026] It is also possible to arrange the anchoring elements in a sticking out position, e.g. in the final lateral position, before introducing the anchor in the ground. A subsequent compression of the ground can additionally contribute to the anchoring elements being surrounded with sufficient soil. It is, however, also possible to introduce a ground anchor further into the ground than the final anchoring position and to then draw the anchor back—possibly under rotation of the anchor—into the final position. The anchoring elements then grip into the soil as with a conventional ship's anchor.
[0027] The anchoring elements can also be distributed at different levels over the perimeter of the anchor, e.g. in a staggered manner. They are however arranged such that, in an installed condition of the anchor, they are completely introduced into the soil. The anchoring elements may be separate elements or in one piece with the anchor.
[0028] Having described exemplary embodiments of the invention with reference to the accompanying drawing, it will be appreciated that the present invention is not limited to those embodiments, and that various changes and modifications can be effected therein by one of ordinary skill in the art without departing from the scope or spirit or the invention as defined by the appended claims.
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A floor system for use in a conservatory or other annexes includes a panelled floor and a frame construction. The frame construction at least partly surrounds the panelled floor. The floor system is anchored in the ground by at least one ground anchor. The use of ground anchors makes a prior excavation substantially completely unnecessary. The floor system is a dry construction system, in which no construction material containing water are used during construction of the floor system.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] “Not applicable”.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] “Not Applicable”.
REFERENCE TO SEQUENCE, ETC.
[0003] “Not Applicable”.
BACKGROUND OF THE INVENTION
[0004] Medicine & Health:
[0005] Transplantable ARtificial Organs—Differs from the prior art in that electromagnetic coils and magnets are used to effect mechanical contraction of the heart.
BRIEF SUMMARY OF THE INVENTION
[0006] Current through solenoids effects attraction and repulsion of magnets on plastic disks on the body of the artificial heart and thereby effects pumping action which emulates that of the natural heart.
[0007] Did not use any other documents or resources other than my own ingenuity and public domain material.
BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWING
[0008] FIG. 1 shows a cross-sectional view of the contemplated embodiment of the invention. The numbers on the drawing refer to the various parts of the elastomeric artificial heart, to wit: 1 , is the plastic tube with integral ball and cage valve (not shown) which, in the case of the left atrium, is surgically attached to the pulmonary vein, number 2 , refers to the Lycra patch which is sutured to the body of the device. Number three is the left atrium, number 4 shows the wall of the heart and a few of the nylon re-inforcing cords that run through it. Number 5 is the left ventricle, 6 is the outlet for the suture to the aorta with another ball and cage valve inside the outlet (not shown), whereas number 7 is the outlet to the pulmonary artery with a similar set-up and another ball and cage valve (also not shown) for the right atrium. Number 8 is the eye hook and spring which controls the action of the flap valve, # 9 , and lastly number 10 is the septum of the heart, which may or may not include a plastic insert for additional strength as the actual working in situ may require.
[0009] FIG. 2 shows a cross-sectional view of a solenoid, # 11 , and a permanent magnet, number 12 , which is anchored to a flat plastic disk, number 13 , which is anchored to the body of the elastomeric artificial heart. There are a number of such units studding the outer surface of the device and it is by means of the reversible current in the solenoids and the attraction and repulsion between the fields of the solenoids and those of the permanent magnets that contraction and expansion of the chambers of the heart is effected, thereby producing a mechanical pumping action that simulates that of the real or natural organ.
DETAILED DESCRIPTION OF THE INVENTION
[0010] Object of the implant is to save the lives of people with cardiac arrest, bullet wounds, or other irreparable damage to the tissues and/or functioning of the heart, and providing a means of saving the lives of those people who currently can not be saved by current surgical techniques.
[0011] The artificial heart is composed of a flexible, elastomeric substance with nylon re-inforcing cords incorporated into the body of the device. If this method proves impractical, then one can use a tightly woven fabric that has been rubberized a la the space suits used by NASA.
[0012] The shape of the artificial heart is exactly similar to that of a real heart, and like the actual human heart, it is composed of four chambers, two atria and two ventricles. The right and left atria have two patches of elastic or Lycra sewn onto the two top entryways into each of these respective two chambers. They are attached to two flexible plastic tubes which are sutured to the vena CAVA and the pulmonary veins. Likewise there is a similar set-up for the aorta and the pulmonary artery for the left and right ventricles, respectively.
[0013] Ball and cage valves are located inside the two plastic tubes oriented so as to permit inflow of blood but block egress of that fluid during the contractile phase of the heart's cycle
[0014] Inside the two atria are nylon screws embedded firmly in the walls of the elastomeric artificial heart. Each nylon screw hooks into a spring which controls a flap valve, which separates the atrium from the ventricle. Upon compression of the atrium, the blood is forced out through the opening between atrium and ventricle as the flap valve opens and the atrium is compressed. The ventricles are filled with blood while the atria empty, upon evacuation, the spring upon the release from its' extension; snaps the flap valve shut, in preparation for the next cycle of filling, compression, expansion, and refilling.
[0015] The two ventricles are similarly equipped with outlets for the aorta and the pulmonary artery; these outlets themselves have ball and cage valves oriented so as to prevent backflow of blood when the ventricles are in their contraction phase.
[0016] The action of the heart is effected in the following manner. The heart is surrounded on all sides by a number of tightly and multiply wound solenoids, which act like magnetic dipoles and are fitted over small magnets attached to plastic disks on the body of the artificial heart. The heart comes with a fine wire and a microelectrode which is surgically implanted in the vagus nerve so that the body's own natural mechanisms are used to initiate the compression cycle of this device. Upon initiation by an impulse from the vagus nerve, a micro-switch or micro-relay is triggered, which then sends current via a microchip controlled fashion to the solenoids surrounding the appropriate area of the artificial heart. This sets up a magnetic field in the solenoids, which either attracts or repells the underlying magnets attahed to the plastic disks studding the body of the heart. By repulsion, compression and contractile force of the elastomeric artificialheart is effected.
[0017] The flexion of the walls of the device drive blood through the body via this electromagnetic-mechanical motion. When the appropriate chamber is drained of blood, a timing circuit in the microchip throws another microswitch, the current is reversed, so that the solenoids now attract the permanent magnets on the Plastic disks and this effects attraction of the said magnets, resulting in an expansion of the walls of the artificial heart, readying it for the next cycle.
[0018] To shield the artificial heart from EMI pulses, there is a wire mexh encasing the device, solenoids, and circuitry. Lastly, the wire mesh is itself along with the whole device, encased in a plastic film which prevents corrosion and leaching of the copper wires into the tissues of the body, thus preventing heavy metal poisoning.
[0019] This completes the description of the artificial heart as I envision it.
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A new type of artificial heart with rechargeable battery to power solenoid means surrounding the body of the device, said solenoids effecting repulsion or attraction of small permanent magnets on plastic disks which stud the body of the elastomeric artificial heart, and via this means effect mechanical compression or expansion of the chambers of the heart.
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This application claims the benefit of U.S. Provisional Patent Application No. 61/383,466 filed Sep. 16, 2010.
FIELD OF THE INVENTION
The present invention relates generally to pathology including cytopathology. Pathology relates to the study and diagnosis of disease generally and cytopathology relates to the study and diagnosis of disease specifically through the identification of cellular features. More particularly, the present invention relates to an automated process for evaluating cellblock preparations through telecytology, which is the use of digital images rather than conventional glass slide microscopy.
BACKGROUND OF THE INVENTION
Pathologists examine specimens—otherwise referred to herein as samples—to determine the type and extent of disease in order to identify the best approach for treatment. With improvements in pathological procedures, cellular features of diseases may be identified in specimens to make diagnoses based on only a few cells.
Typically, specimens are examined using a light microscope in order to diagnose or detect disease. The specimen is retrieved from a patient and processed for microscopic examination. A variety of minimally invasive techniques are available for retrieving cell sample specimens from a patient. For example, specimens may be retrieved by using fine needle aspiration or by brushing body cavity surfaces such as through endoscopic techniques. After the specimens are retrieved, the cells are prepared for evaluation. A number of preparation techniques are known—such as the Cytospin® technique and the ThinPrep® technique—for depositing cellular materials and/or tissue fragments onto a microscope slide. Another technique, commonly referred to as a cellblock preparation, isolates and immobilizes cellular materials and/or small tissue fragments. Cellular materials and/or small tissue fragments may be isolated using centrifugation and/or manually embedded within a solid support structure such as paraffin wax. Thin sections of the cellblock are then cut and placed or secured onto a microscope slide—a thin flat piece of glass—for examination under a microscope. Microscope slides are often used together with a cover slip or cover glass—a thinner flat piece of glass—that is placed over the specimen. Slides may be held in place on the stage of the microscope by slide clips or slide clamps.
Cervical cancer is just one type of disease that is detected or diagnosed through the examination of specimens. Although the invention is discussed herein with respect to cervical cancer, any disease is contemplated. In the 1930s, cervical cancer was the most common cause of cancer deaths in women in the United States. Today, cervical cancer is not even in the top ten. The significant decline in both the incidence and mortality of cervical cancer is attributed to the Papanicolaou test, or Pap test—also called Pap smear, cervical smear, or smear test—, which is a screening test used in gynecology to detect premalignant and malignant cells in the ectocervix and endocervix.
The Pap smear has been proven to be the most useful test for the detection of precancerous and cancerous lesions of the cervix. It is estimated that over 3.5 million women in the United States each year have an abnormal Pap smear. The Bethesda System (“TBS”) is a system for reporting Pap smear results. Abnormal results include Atypical Squamous Cells of Undetermined Significance (“ASC-US”) and Atypical Squamous Cells—Cannot Exclude High Grade Squamous Intraepithelial Lesion (“ASC-H”). Abnormal results further include Low Grade Squamous Intraepithelial Lesion (“LGSIL”), High Grade Squamous Intraepithelial Lesion (“HGSIL”), Squamous cell carcinoma, Atypical Glandular Cells Not Otherwise Specified (“AGC-NOS”), Atypical Glandular Cells, Suspicious for AIS or Cancer (“AGC-neoplastic”), and Adenocarcinoma in situ (“AIS”). LGSIL indicates mild dysplasia (“CIN 1”) including that caused by a Human Papillomavirus (“HPV”) infection. HGSIL indicates moderate dysplasia (“CIN 2”) or severe dysplasia (“CIN 3”) and may include carcinoma in situ as well as features suspicious for invasion, glandular cell including atypical such as endocervical cells, endometrial cells, glandular cells, endocervical cells favor neoplastic, glandular cells favor neoplastic, or adenocarcinoma in situ or adenocarcinoma (Endocervical, Endometrial, Extrauterine, Not otherwise specified).
Current techniques for obtaining Pap test samples include the conventional smear and the more recently preferred liquid-based procedures. The conventional smears are often obtained using a combination of a plastic spatula, brush or a broom-like brush in which the tissue surface is scraped. The cells obtained require immediate coating fixation with ethanol and polyethylene followed by submersion in 95% ethanol to prevent air-drying artifact that may interfere with appropriate evaluation of the samples.
Poor sensitivity of the conventional smears became apparent in the 1990's. Several studies have shown that the mean sensitivity of the conventional smear ranged from 37% at worst to 73% at best. When sources of errors with the conventional smear were analyzed, it was discovered that sampling and/or preparation errors were responsible for about two-thirds of false negative cases. In those situations, cells were either not collected properly or cells that were collected were not properly transferred to slides. Screening and/or interpretive errors were the cause for the remaining one-third of false negative cases. Abnormal cells were either missed by the cytotechnologist/pathologist or were incorrectly classified because of poor preservation. Due to the problems with conventional techniques liquid-based procedures were developed in which body fluids are collected.
The liquid-based procedures mitigated sampling errors and improved cell preservation. Cell preservation was improved through randomized representation and even distribution of cells with minimization of obscuring material such as inflammation, blood, and debris. With respect to Pap smears, liquid-based procedures are significantly more effective in detecting LGSIL and HGSIL and are as effective as conventional smears in detecting endocervical lesions.
Despite its proven value, the Pap test remains less than optimal. Sensitivity of the Pap test continues to be a subject of concern. False negative and false positive results of various values are reported and inter-observer reproducibility remains less than perfect. The greatest disagreement involves the results interpreted as ASCUS.
It has recently been proposed that HPV testing is of potential value in the screening of cervical cancer precursors. Several studies have shown that a combination of HPV testing and repeated cytologic screening provides reasonable sensitive screening for cervical neoplasia while limiting the use of colposcopic services, which are currently burdened. HPV testing appears to provide an objective assessment of neoplasia risk. A major advantage of this test is its potential for “reflex testing” when used in liquid-based cytology. Reflex testing for HPV is currently recommended by many clinicians and is considered routine in many centers all over the world. HPV-negative patients could be triaged to yearly follow-ups, while HPV-positive patients would require further colposcopic evaluation. Current commercially available HPV tests include the DiGene HPV Test with Hybrid Capture II (“HC2”), Cervista HPV, INFORM HPV in situ hybridization test as well as a variety of molecular HPV DNA assays.
Currently there are several automated screening devices that utilize digital images of specimens for evaluation. Digital pathology is rapidly gaining momentum as a proven and essential technology that assists with reducing laboratory expenses, improving operational efficiency, enhancing productivity, and improving treatment decisions and patient care. It is used worldwide in drug development, reference labs, hospitals, and academic medical center settings.
Digital pathology includes the use of automated screening devices that combine robotics, automated microscopes, high-performance cameras for image capturing and sophisticated computer algorithms for high-speed analysis. Automated screening devices have several advantages including easier location of abnormal and rare cytologic findings as well as coupling automated screening with cytotechnologist skills.
Currently there are two systems approved by the FDA in the United States for automated screening of Pap smears—the FocalPoint Slide Profiler and the ThinPrep® Imaging system.
In 1998, the Food and Drug Administration (“FDA”) approved the AutoPap system—the the forerunner of the FocalPoint Slide Profiler—as a system to rank and score Pap smear specimens according to their likelihood of being abnormal. Each specimen is classified into one of two groups: “Review” and “No Further Review”. The “Review” specimens are then ranked into five quintiles based on the severity of the abnormality.
The ThinPrep® Imaging system consists of two elements: an image processor and a review scope. Only specially prepared specimens using a synthetic nuclear dye “ThinPrep® Stain” may be used for analysis with this system. Up to 288 slides may be loaded on the system at a time. The image processor identifies 22 microscopic fields, which are reviewed by a cytotechnologist with an automated review scope. Results are then reported as either “normal” or “abnormal”, with “abnormal” cases undergoing full glass slide screening for diagnosis.
The impact of digital imaging on routine day-to-day cytology remains far from perfect. Problems with digital imaging for routine cytology is due, in part, to inexperience, poor reproducibility, poor image quality, under representation or under-diagnosis of lesions and the length of time required for capturing images (in addition to the realization that fewer than 5% of women in underdeveloped and developing countries have ever had a Pap test).
Therefore, there is a demand for an improved screening and diagnostic tool used in cytopathology, for example alternative methods to routine Pap tests. The improved screening and diagnostic tool of the present invention satisfies this demand by using digital imaging technology to overcome current limitations with cytologic specimens.
SUMMARY OF THE INVENTION
The present invention is a system and methods for digital evaluation of cellblock (“CB”) preparations. Although the present invention is discussed herein with reference to gynecology and specifically cervical cancer, it is contemplated that the present invention is applicable to CB evaluation of any medical specialty such as andrology and any disease such as prostate cancer. More specifically, it is contemplated that the present invention may be applied to CB evaluation of any organ or tissue, for example, urinary tract, breast, thyroid, lymph node, lungs, stomach, bone, skin, kidney, liver, pancreas, eye, and central nervous system, to name a few.
In embodiments discussed with reference to gynecology, digital evaluation of CB preparations of Pap smears is an alternative method to routine and/or liquid based Pap smears. According to the present invention, digitally assisted review of Pap smear CBs is a valid screening/diagnostic tool. More specifically, CB preparations are used from the discarded/residual conventional and liquid-based samples. Digital evaluation of CBs prepared from Pap samples is a feasible method for widespread adoption to achieve high quality specimen preparations providing consistent, reliable and timely diagnosis that may reduce the biopsy load significantly, especially in a resource-poor settings.
In addition to analyzing most cervical cancer precursors, it is contemplated that HPV in situ hybridization (“ISH”) and other immunohistochemical (“IHC”) testing may be performed on CBs, including evaluation and correlation to clinic-pathological data, without the need for additional testing or sampling.
In one embodiment, the present invention produces cellblock preparations from Pap smear specimens. Specifically, cellblock preparations are sliced and digitized such that computer-assisted diagnosis software may be applied in order to obtain a diagnosis. According to the present invention, each cell within the cellblock preparation is located and ranked according to the level of abnormality and level of suspicion. Automated computer vision techniques are able to prescreen digital images to flag suspicious regions and to discard areas of images that contain clearly healthy tissue. Automated prescreening alleviates the fatigue faced by professional pathologists, who must often spend hours peering through microscopes. Visual fatigue is known to reduce diagnosis accuracy.
A digital image—otherwise referred to herein as a “virtual slide”—may be archived such as within a repository or database. Numerous digital images further may be organized, searchable, or retrievable such as by any characteristic associated with a particular digital image. It is also contemplated that the images may be posted for accessibility from anywhere. For example, the images may be posted on a cloud computing network such that the images may be viewed, downloaded, or modified, from anywhere in the world. Digital slide images make it possible to consult with expert pathologists remotely and may be better used in education, either in published material or on-line. In one embodiment, the design and optimization of an on-line integrated, automated Internet-based platform assists in the review and analysis of the virtual slides prepared from Pap smears converted into CBs. It is contemplated that an Internet based diagnostic process allows slides prepared from CBs to be reviewed and digitally analyzed, and further allows access to the CBs digital slides remotely.
According to the invention, the Internet-based platform provides accurate, complete, expedited and integrated cytological consultations. It is contemplated that cytotechnologists, pathologists and cytopathologists are able to remotely review, analyze and report their cytologic diagnosis using their own computer without the aid or the need of a microscope or the requirement to be physically located in the laboratory. It is also contemplated that reports may be electronically sent to medical records, physicians and patients in real time through the Internet. In addition, the wide array of computer-assisted image analysis tools are leveraged for diagnosis and quantification of digitized CB slides along with the ancillary studies including ISH for HPV and the different IHC prognostic markers.
In one embodiment, the platform allows human users to access and analyze the digital images. In another embodiment, while human users may access the images, the platform includes computer-assisted diagnosis software that performs the analyses. In this embodiment, the platform may include the design and optimization of a computer-aided image-based scoring algorithm. The algorithm may be suitable for a remote, Internet-based access and review of Pap smears. Internet-based access may be GPS guided such that access is based upon location of the user. The computer-aided image-based scoring algorithm performs analysis through machine learning techniques, for example, techniques to search for highly discriminative visual features that are maximally predictive of cancer and precancer grading.
The computer-aided image-based scoring algorithm may further allow for the automated detection of different histopathologic features of all kinds of cytologic specimens, automated detection of HPV in the specimens, automated detection and quantitation of different prognostic markers such as p53, Ki-67, p16 and automated reporting.
The computer software may further include hierarchical graphical models. Hierarchical graphical models learn the statistical properties of different classes of images by recursively learning visual features of increasing complexity. Features learned in the first layer include only simple linear qualities of the image. Features within the second layer build off of features from the first layer, allowing deeper layers to capture increasingly complex statistical trends in the images. Hierarchical graphical models are closely related to neural networks of which the layer-by-layer learning techniques makes the automated learning of complex image features feasible to identify textural cues in images that are maximally discriminative towards cancer cells.
An object of the present invention is to achieve accurate diagnosis, provide high quality preparations, consistent results, and timely reports.
Another object of the present invention is to provide a highly automated and optimized system and methods for routine cytology, HPV and other prognostic marker detection such as p16, p53 and Ki-67 at a reduced cost.
Another object of the present invention is to provide a system and methods for widespread adoption to achieve accurate diagnosis.
Another object of the present invention is to allow additional tests, such as HPV testing, to be readily available to pathologists with ease and practicality.
Another object of the present invention is to improve the diagnostic accuracy by incorporating histology, IHC and in situ results.
Another object of the present invention is to improved care to patients with cervical cancer and its precursors. Additionally, the automation in the review of digital slides and in recording patient's demographics is easier and more accurate than the conventional manual method.
Another object of the present invention is to provide an Internet-based system that allows interaction between cytotechnologists, pathologists, cytopathologists, consultants, and clinicians. It is recognized that the Internet-based system may be carried out on computer hardware and/or networks.
Another object of the present invention is to provide an Internet-based system including software to direct the analysis of the present invention and allow the remote accessibility to generate diagnostic reports.
These and other aspects, features, and advantages of the present invention will become more readily apparent from the attached drawings and the detailed description of the preferred embodiments, which follow.
DESCRIPTION OF THE DRAWINGS
The invention can be better understood by reading the following detailed description of certain preferred embodiments, reference being made to the accompanying drawings in which:
FIG. 1 illustrates a flow chart for creating a digital image of a cellblock preparation according to the invention;
FIG. 2 illustrates a flow chart for evaluating the digital image of a cellblock preparation according to the invention;
FIG. 3 illustrates a flow chart for processing the digital image of a cellblock preparation according to the invention;
FIG. 4 illustrates an exemplary computer system that may be used to implement the methods according to the invention; and
FIG. 5 illustrates an exemplary cloud computing system that may be used to implement the methods according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates a flow chart 100 for creating a digital image of a cellblock preparation. At step 102 , a tissue specimen is collected such as a Pap smear sample according to one embodiment of the invention. After collection of the tissue specimen, a cellblock is created at step 104 . According to cellblock preparation, cellular materials and/or small tissue fragments are isolated and immobilized such as by centrifugation. The cellblock is then manipulated at step 106 . Manipulation of the cellblock may include slicing the cellblock preparation, treating the cellblock preparation, or preforming ancillary testing. It is contemplated that the Pap smear sample may be treated such as with Haematoxylin Eosin (“H&E”) staining. Ancillary tests include in situ hybridization (“ISH”), immunohistochemical (“IHC”) and Human Papillomavirus (“HPV”). The ISH ancillary test may be used to study low and high risk HPV subtypes. The IHC ancillary test may be used in order to study p16 and other markers such as Ki-67 (MIB-1 clone) and p53, although any marker is contemplated. At step 108 , the Pap smear specimen is digitally scanned to obtain a digital image for evaluation. By converting a Pap smear into a tissue section, all issues with image quality are eliminated.
FIG. 2 illustrates a flow chart 200 for evaluating the digital image of a cellblock preparation by a computer system, specifically a feature extraction component. The digital image is segmented at step 202 such that each segment may be processed. Since digital images are typically very large, loading the full image into memory of a computer system and processing the image all at once is usually prohibited by the computer system. Therefore, the digital image is segmented such as into square tiles. A single tile typically contains hundreds of cells, although it is contemplated that one or more tiles may contain no cells at all. The square tiles may be bound by pixel size requirements, for example 3000 pixels by 3000 pixels. It is contemplated that each tile may be stored within the computer system as a separate file. Therefore, the files may be analyzed independently of one another, possibly on different computers.
Segmenting the digital image allows segments—or tiles—to be processed simultaneously at step 204 such that all segmented digital images are processed in parallel. Tiles may be processed in parallel using any method as known to those skilled in the art, for example, using multiple cores on the same processor, using multiple processors, or using multiple computers. The tiles overlap by a few hundred pixels to ensure that at least one tile contains a cell in its entirety. The processing step 204 is described in further detail below with respect to FIG. 3 .
After each digital image segment or tile is processed at step 204 , the digital image segments are joined at step 206 by a classification component of the computer system to obtain a final digital image. The final digital image is an integration of all processes performed on each digital image.
Visual features such as properties of the final digital image are collected at step 208 . Visual features include morphological features, textural features, and architectural features described more fully in reference to FIG. 3 . The visual features are then correlated to a diagnosis classification at step 212 . In one embodiment the diagnosis classification is the Bethesda System for reporting Pap smear results, including for example, Low Grade Squamous Intraepithelial Lesion (“LGSIL”) and High Grade Squamous Intraepithelial Lesion (“HGSIL”). The diagnosis classification is communicated at step 212 to a user. The diagnosis may be communicated, for example, through a visual interface such as a display device or auditory interface such as a speaker.
FIG. 3 illustrates a flow chart 300 for processing the digital image of a cellblock preparation according to step 204 of FIG. 2 . Specifically, digital image segments or tiles are processed by first locating a nucleus of each cell at step 302 . More specifically, the exact location and outline of each cell nucleus is identified. The step 302 of locating a nucleus of a cell within each segmented digital image or tile may further comprise the step of applying a quadratic filter to obtain a filtered image. The quadratic filter begins by mapping (3-dimensions) R G B color space into a higher-dimensional (specifically, 10-dimensions) non-linear color space. In one embodiment, the non-linear color space may be described by: 1, R, G, B, R^2, R*G, R*B, G^2, G*B, B^2. A linear discriminant method, such as the Fischer method, may be used to find a linear combination of features which characterize the nucleus and its surrounding features. The linear discriminant method finds a vector within the color space that best discriminates a cell nucleus from non-nucleus pixels. The advantage of using a linear discriminate method is that it allows nuclei to be located very quickly, while maintaining accuracy. The nuclei outlines of each filtered image may be distinguished, even in the event when two nuclei overlap slightly. As mentioned above, it is contemplated that the analysis of each tile is performed simultaneously such that the tiles are processed in parallel.
One or more visual features of the nucleus are quantified by extracting the features at step 304 . The feature extraction component locates each cell in the input image and quantifies roughly a certain number of visual features—such as 100—that describe those cells and their surroundings. Visual features are identified to discriminate healthy from abnormal tissue and to eliminate features that are not effective. The visual features extracted may be grouped into three broad categories: morphological features, textural features, and architectural features. The visual features of the nucleus are ranked at step 306 according to the category into which the feature is grouped. It is also contemplated applying hierarchical graphical models may be applied to learn more complex visual features to discriminate cell types.
Morphological features describe physical properties of cells or the statistics of those properties over groups of cells. These features include the degree of variance of nuclei size and aspects of nuclei shape. Textural features describe low-level visual properties, which, in the case of histologic diagnosis applications, are designed to capture visual qualities including increase in nucleus size and the prominence of nucleoli. These features are measured by the histograms and co-occurrence matrices of pixel colors.
Co-occurrence matrices for quantifying texture properties may be used as known to those skilled in the art. Once the co-occurrence matrix is computed, four types of texture features that are found to be particularly discriminative are computed from the co-occurrence matrix. The texture features include energy, homogeneity, correlation, and contrast. Energy is the sum of the square of elements in the co-occurrence matrix, and describes the total amount of texture variation within the segmented digital image or tile. Homogeneity describes how close the distribution of elements in the co-occurrence matrix is to a diagonal matrix—which may indicate a uniform, textureless pattern in the segmented digital image. Correlation describes how correlated a pixel is to its neighbor over the entire segmented digital image. Contrast is the average intensity contrast between a pixel and its neighbor over the entire segmented digital image.
Textural features capture the first and second order statistics of cellular appearance. Textural properties have an advantage in that they cannot be disturbed by errors that may occur during cell segmentation or other intermediate processing steps. Architectural features describe the spatial arrangement of cells within tissue. For example, if the image is larger than a single tile, then the 20 nearest neighbors of any cell may lie outside the tile boundaries. For this reason, the computation of nearest-neighbor features is performed unless the image is smaller than a single tile.
It is also contemplated that support vector machines (“SVMs”) may be used for diagnosis classification based on the quantified features. Specifically, SVMs may be used to predict or learn the relationship between quantified features of each cell and the diagnosis classification. For example, in one embodiment the quantified features of each cell are mapped to a very high-dimensional space such as an infinite dimensional space such that boundaries may be searched to separate healthy cells from unhealthy ones in a way that maximizes the margin between the two cell types.
According to one embodiment of the invention, images—digital images, segmented digital images, and/or final digital images—may be archived within an on-line integrated, automated Internet-based platform. The images may be archived within a database or repository and further may be organized, searchable, or retrievable by any characteristic associated with the digital image. It is also contemplated that the images may be posted for accessibility from anywhere. For example, the images may be posted on a cloud computing network such as within a repository or database so that the images may be viewed, downloaded, or modified, from anywhere in the world.
In one embodiment, the design and optimization of an on-line integrated, automated Internet-based platform assists in the review and analysis of the virtual slides prepared from Pap smears converted into CBs. It is contemplated that an Internet based diagnostic process allows slides prepared from CBs to be reviewed and digitally analyzed, and further allows access to the CBs digital slides remotely.
In one embodiment, the platform allows human users to access and analyze the digital images. The platform may include computer-assisted diagnosis software that performs analyses on the digital images. For example, the platform may include the design and optimization of a computer-aided image-based scoring algorithm. The algorithm may be suitable for a remote, Internet-based access and review of Pap smears. The computer-aided image-based scoring algorithm performs analysis through machine learning techniques, for example, techniques to search for highly discriminative visual features that are maximally predictive of cancer and pre-cancer grading.
FIG. 4 illustrates an exemplary computer system 400 that may be used to implement the methods according to the invention. One or more computer systems 400 may carry out the methods presented herein.
Computer system 400 includes an input/output display interface 402 connected to communication infrastructure 404 —such as a bus—, which forwards data such as graphics, text, and information, from the communication infrastructure 404 or from a frame buffer (not shown) to other components of the computer system 400 . The input/output display interface 402 may be, for example, a keyboard, touch screen, joystick, trackball, mouse, monitor, speaker, printer, any other computer peripheral device, or any combination thereof, capable of entering and/or viewing data including the diagnosis classification as communicated to a user.
Computer system 400 includes one or more processors—specifically a feature extraction component 406 and a classification component 408 , which may be a special purpose or a general-purpose digital signal processor that processes certain information. Specifically, the feature extraction component 406 receives digital images, segments the digital images, locates a nucleus of a cell within each segmented image, and ranks one or more visual features of the nucleus and the classification component 408 joins all segmented images to obtain a final digital image, collects features of the final digital image, and correlates the features to a diagnosis classification.
Computer system 400 also includes a main memory 410 , for example random access memory (“RAM”), read-only memory (“ROM”), mass storage device, or any combination thereof. Computer system 400 may also include a secondary memory 412 such as a hard disk unit 414 , a removable storage unit 416 , or any combination thereof. Computer system 400 may also include a communication interface 418 , for example, a modem, a network interface (such as an Ethernet card or Ethernet cable), a communication port, a PCMCIA slot and card, wired or wireless systems (such as Wi-Fi, Bluetooth, Infrared), local area networks, wide area networks, intranets, etc.
It is contemplated that the main memory 410 , secondary memory 412 , communication interface 418 , or a combination thereof, function as a computer usable storage medium, otherwise referred to as a computer readable storage medium, to store and/or access computer software including computer instructions. For example, computer programs or other instructions may be loaded into the computer system 400 such as through a removable storage device, for example, a floppy disk, ZIP disks, magnetic tape, portable flash drive, optical disk such as a CD or DVD or Blu-ray, Micro-Electro-Mechanical Systems (“MEMS”), nanotechnological apparatus. Specifically, computer software including computer instructions may be transferred from the removable storage unit 416 or hard disc unit 414 to the secondary memory 412 or through the communication infrastructure 404 to the main memory 410 of the computer system 400 .
Communication interface 418 allows software, instructions and data to be transferred between the computer system 400 and external devices or external networks. Software, instructions, and/or data transferred by the communication interface 418 are typically in the form of signals that may be electronic, electromagnetic, optical or other signals capable of being sent and received by the communication interface 418 . Signals may be sent and received using wire or cable, fiber optics, a phone line, a cellular phone link, a Radio Frequency (“RF”) link, wireless link, or other communication channels.
Computer programs, when executed, enable the computer system 400 , particularly the processors—feature extraction component 406 and classification component 408 —, to implement the methods of the invention according to computer software including instructions.
The computer system 400 described herein may perform any one of, or any combination of, the steps of any of the methods presented herein. It is also contemplated that the methods according to the invention may be performed automatically, or may be invoked by some form of manual intervention.
The computer system 400 of FIG. 4 is provided only for purposes of illustration, such that the invention is not limited to this specific embodiment. It is appreciated that a person skilled in the relevant art knows how to program and implement the invention using any computer system.
The computer system 400 may be a handheld device and include any small-sized computer device including, for example, a personal digital assistant (“PDA”), smart hand-held computing device, cellular telephone, or a laptop or netbook computer, hand held console or MP3 player, tablet, or similar hand held computer device, such as an iPad®, iPad Touch® or Phone®.
FIG. 5 illustrates an exemplary cloud computing system 500 that may be used to implement the methods according to the present invention. The cloud computing system 500 includes a plurality of interconnected computing environments. The cloud computing system 500 utilizes the resources from various networks as a collective virtual computer, where the services and applications may run independently from a particular computer or server configuration making hardware less important.
Specifically, the cloud computing system 500 includes at least one client computer 502 . The client computer 502 may be any device through the use of which a distributed computing environment may be accessed to perform the methods disclosed herein, for example, a traditional computer, portable computer, mobile phone, personal digital assistant, tablet to name a few. The client computer 502 includes memory such as random access memory (“RAM”), read-only memory (“ROM”), mass storage device, or any combination thereof. The memory functions as a computer usable storage medium, otherwise referred to as a computer readable storage medium, to store and/or access computer software and/or instructions.
The client computer 502 also includes a communications interface, for example, a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, wired or wireless systems, etc. The communications interface allows communication through transferred signals between the client computer 502 and external devices including networks such as the Internet 504 and cloud data center 506 . Communication may be implemented using wireless or wired capability such as cable, fiber optics, a phone line, a cellular phone link, radio waves or other communication channels.
The client computer 502 establishes communication with the Internet 504 —specifically to one or more servers—to, in turn, establish communication with one or more cloud data centers 506 . A cloud data center 506 includes one or more networks 510 a , 510 b , 510 c managed through a cloud management system 508 . Each network 510 a , 510 b , 510 c includes resource servers 512 a , 512 b , 512 c , respectively. Servers 512 a , 512 b , 512 c permit access to a collection of computing resources and components that may be invoked to instantiate a virtual machine, process, or other resource for a limited or defined duration. For example, one group of resource servers may host and serve an operating system or components thereof to deliver and instantiate a virtual machine. Another group of resource servers may accept requests to host computing cycles or processor time, to supply a defined level of processing power for a virtual machine. A further group of resource servers may host and serve applications to load on an instantiation of a virtual machine, such as an email client, a browser application, a messaging application, or other applications or software.
The cloud management system 508 may comprise a dedicated or centralized server and/or other software, hardware, and network tools to communicate with one or more networks 510 a , 510 b , 510 c , such as the Internet or other public or private network, with all sets of resource servers 512 a , 512 b , 512 c . The cloud management system 508 may be configured to query and identify the computing resources and components managed by the set of resource servers 512 a , 512 b , 512 c needed and available for use in the cloud data center 506 . Specifically, the cloud management system 508 may be configured to identify the hardware resources and components such as type and amount of processing power, type and amount of memory, type and amount of storage, type and amount of network bandwidth and the like, of the set of resource servers 512 a , 512 b , 512 c needed and available for use in the cloud data center 506 . Likewise, the cloud management system 508 may be configured to identify the software resources and components, such as type of Operating System (“OS”), application programs, and the like, of the set of resource servers 512 a , 512 b , 512 c needed and available for use in the cloud data center 506 .
The present invention is also directed to computer products, otherwise referred to as computer program products, to provide software to the cloud computing system 500 . Computer products store software on any computer useable medium, known now or in the future. Such software, when executed, may implement the methods according to certain embodiments of the invention. Examples of computer useable mediums include, but are not limited to, primary storage devices (e.g., any type of random access memory), secondary storage devices (e.g., hard drives, floppy disks, CD ROMS, ZIP disks, tapes, magnetic storage devices, optical storage devices, Micro-Electro-Mechanical Systems (“MEMS”), nanotechnological storage device, etc.), and communication mediums (e.g., wired and wireless communications networks, local area networks, wide area networks, intranets, etc.). It is to be appreciated that the embodiments described herein may be implemented using software, hardware, firmware, or combinations thereof.
The cloud computing system 500 of FIG. 5 is provided only for purposes of illustration and does not limit the invention to this specific embodiment. It is appreciated that a person skilled in the relevant art knows how to program and implement the invention using any computer system or network architecture.
While this disclosure is susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and have herein been described in detail. It should be understood, however, that there is no intent to limit the disclosure to the particular embodiments disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure as defined by the appended claims.
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Digital evaluation of cellblock preparations to determine the type and extent of disease in order to identify the best approach for treatment without the need for additional testing or sampling.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] A wide variety of products to facilitate the attachment of lightweight items, such as pieces of paper, printed matter, child art projects and the like, to walls and other smooth surfaces are well-known in the art. Exemplary of such products include magnets, magnets having clips attached thereto, suction cups, tape, and other adhesive products. Essentially, such products are operative to form a simple attachment arrangement, whether it be by magnetic attraction, vacuum, or adhesive forces, that are strong enough to support one or more lightweight items. Such items find particularly wide spread use in attaching papers, grocery lists, child artwork, stickers, signs, emblems, labels, and the like to refrigerators, windows, plastic message boards and other smooth surfaces.
[0004] Despite the low cost and wide spread availability of such products, however, each of the aforementioned types of attachment means suffer from distinct drawbacks. With respect to the use of magnets, the same can only be utilized with magnetic receptive surfaces. For example, magnets are ineffective to work on stainless steel, and thus cannot be utilized on appliances and other surfaces that are made from stainless steel. The use of adhesives, such as tape and the like, can produce sticky adhesive residues that become unsightly, are difficult to remove, and, in the case of woodwork, can potentially damage the finish of the woodwork. Other devices, such as suction cups and the like, have limited holding power and to the extent the vacuum seal is broken, such devices are ineffective for their intended purpose.
[0005] Accordingly, there is a substantial need in the art for a simple mechanism, and in particular a method that is operative to secure and hold one or more light weight items, and which can be removed without residue, which is also relatively great enough in thickness, dimension, and density that even a toddler or small child can easily grasp and peel away with their fingers or fingertips, then re-attach and re-use repeatedly. There is additionally a need in the art for such a method that utilizes existing materials that are readily available, low cost, safe and easy to use, non-toxic, and capable of being reused indefinitely. There is still further a need in the art for such a mechanism that can find widespread application in arts and crafts, and in particular for use as toys, frames, teaching aides and a variety of other related uses.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention specifically addresses and alleviates the above-identified deficiencies in the art. In this regard, the present invention is directed towards methods of utilizing an expanded polyvinylchloride (PVC) foam material to attach one or more lightweight items to a non-porous surface, as well as utilize such material to prevent such foam material and/or items secured thereby from slipping, sliding, moving or falling away from a non-porous surface. Such expanded PVC material can operatively be positioned vertically, horizontally, in inclined or declined angles, and even upside down. Among the applications contemplated for use of such PVC foam material include mouse pad fabrication, signs, flexible frames for use in framing artwork, attachment means for securing one or more lightweight items, such as pieces of paper and the like, to non-porous surfaces, as a teaching aid for use in positioning and re-positioning items such as letters, numbers, figurines, and related shapes and sizes. Further, such expanded PVC material can, as is commonly used and found readily available in art and craft industry, where one can then display and affix to a non-porous surface, with the ability to remove, re-affix and reposition effortlessly.
[0007] According to a preferred embodiment, the expanded PVC foam will preferably be formed to have a density ranging between 5-25 pounds per cubic foot. In a most preferred embodiment, the expanded PVC foam will have a density ranging between 8 to 15 pounds per cubic foot, as well as a coefficient of friction of approximately 0.86. The foam will preferably be formed as a cast (i.e., hot molten state) and expanded soft PVC cohesive cellular foam that may be formed upon casting paper, such as silicone or melamine treated paper, well known to those skilled in the art. One commercial product that is particularly well-suited for practice of the present invention is Cling Foam™ produced by Gaska Tape, Inc. of Elkhart, Ill.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These as well as other features of the present invention will become more apparent upon reference to the drawings.
[0009] FIG. 1 is a perspective view of a flexible frame formed form an expanded PVC foam material utilized to hang a piece of paper upon a non-porous surface.
[0010] FIG. 2 is a perspective view of letters formed from the expanded PVC foam material of the present invention shown adhering to a non-porous surface.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The detailed description set forth below is intended as a description of the presently preferred embodiment of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the functions and sequences of steps for constructing and operating the invention. It is to be understood, however, that the same or equivalent functions and sequences may be accomplished by different embodiments and that they are also intended to be encompassed within the scope of the invention.
[0012] The present invention is directed to novel uses of an expanded PVC foam material to adhere to a non-porous surface. In particular, it is contemplated that the expanded PVC foam will be useful as arts and crafts materials that can likewise function as either a teaching aid, toy or as means for hanging or securing objects and decorative items to a non-porous surface, which surface may be glass, metal, plastic and plastic films, including coated glossy papers and laminates, such as dry erase surfaces. It is contemplated that the use of the expanded PVC foam material of the present invention can be utilized to replace conventional refrigerator magnets, tapes, adhesives, suction cups and other like mechanisms known in the art to facilitate the hanging of lightweight objects. It is likewise contemplated that the use of the expanded PVC foam material of the present invention can be utilized in other related applications where it is desired to provide a non-skid placement of a foam material upon a non-porous surface. Further, such expanded PVC foam material can also be utilized in such a fashion as to create a desirable 3D, or three-dimensional visual effects, while hanging and securing objects and other decorative items to a non-porous surface.
[0013] With respect to the expanded PVC foam material, the same may be prepared pursuant to the teachings of U.S. Pat. No. 4,921,739, entitled Self-Adherent Foam Strip, the teachings of which are expressly incorporated herein by reference. Preferably, such expanded PVC foam material will be formed by casting such materials in a hot molten state upon casting paper, such as either silicone or melamine-treated casting paper, that is operative to impart a smooth and shiny surface to the foam material. By virtue of the properties associated with the expanded PVC foam material, the same will possess a high surface tension and a high coefficient of friction, which is most noticeable on that side of the PVC foam formed upon the casting paper. The combination of the high surface tension and high coefficient of friction are operative to impart a cohesive force, as opposed to a cling or electrostatic attraction means.
[0014] In a most highly preferred embodiment, such expanded PVC foam material will be formed to have the following properties as set forth in Table 1.
TABLE 1 Size/Range Parameter Test Method Condition Specification Gauge .015″-.50″ +/−20% Density ASTM D1667 7.0-15.0 (lbs./Cu. Ft.) Tensile ASTM D412 52.9 PSI Strength Elongation % ASTM D412 152% Peel PSTC-1 20 Minute Dwell 0.22 lbs./ (stainless linear in. steel) 1 Hour Dwell 0.23 lbs./ linear in Shear PSTC-7 250 grams/sq. in. 5 Minutes Dynamic Shear 12.2 lbs. Shear Adhesion ASTM D1000 1″ × 1″, 1.0 lbs. 33.2 secs. 2″ × 2″, 3.0 lbs. 173.6 secs. 2″ × 2″, 5.0 lbs. 45.0 secs. Coefficient ASTM D2047 Dry Surface 0.86 of Friction Condition (avg. over 8 cycles)
[0015] Such expanded PVC foam material is commercially available and sold as Cling Foam™ produced by Gaska Tape, Inc. of Elkhart, Ill. It is likewise contemplated that a variety of other commercially-available expanded PVC foam materials may also work for use in the present invention and can be readily fabricated to possess the aforementioned properties utilizing manufacturing techniques that are well-known in the art.
[0016] As discussed above, the cohesive properties possessed by such foam enable the same to be advantageously utilized in a variety of applications, and in particular arts and crafts. Referring now to the Figures, and initially to FIG. 1 , there is shown an example of a first application whereby the expanded PVC foam is formed as a simple flexible rectangular frame 10 that is utilized to secure a document therein, such as a piece of paper or artwork 12 , upon a non-porous surface 14 . As illustrated, the piece of paper need only be generally centered within such frame with the parameter of such frame coming into contact with the non-porous surface. By virtue of the cohesive attraction between the PVC frame and the non-porous surface, such frame is thus caused to be retained and secured into position to thus hold the piece of paper centered therein in place. To the extent it is desired to move such frame, such flexible frame need only be peeled away from the non-porous surface, as indicated by the letter “A”.
[0017] Advantageously, the materials of the present invention can be repeatedly utilized and not loose its effectiveness to adhere to a non-porous surface. As will be appreciated, however, to preserve such ability will generally require that the surfaces of the PVC material and non-porous surface to which the PVC material is engaged be kept clean and smooth.
[0018] In addition, the expanded PVC materials of the present invention need not rely upon a metal or magnetic receptive surface, as do magnets, and likewise do not leave any residue, as can occur with the use of tapes and adhesives. Moreover, once the cohesive forces are established between the PVC material and the non-porous substrate, the material will thus remain in position indefinitely, and the ability by which the expanded PVC foam remains secure will not diminish over time.
[0019] In addition to the foregoing, given the high coefficient of friction possessed by such materials, it is contemplated that the expanded PVC foam materials can be placed in any of a variety of orientations, whether it be on an incline, decline, vertical, or even any upside down orientation. With respect to the latter, it should be understood that due to gravitational restraints, the ability of the expanded PVC foam materials to retain and support an object may be less than if such material were maintained in a vertical or inclined orientation.
[0020] It is also contemplated that such expanded PVC foam materials can be utilized in combination with other such attachment mechanisms, such as magnets, adhesives, and the like to thus provide a more enhanced ability to remain more securely in position. Likewise, it is contemplated that the expanded PVC foam may include clips or hook to facilitate the ability of the foam to attach common lightweight items, such as documents, keys and the like. Moreover, the foam of the present invention can be utilized in non-hanging applications, and may be ideally suited for items such as mouse pads and the like that must necessarily be made of a foam material, but at the same time ideally possess a high enough coefficient of friction to enable such foam material to remain in stationery position.
[0021] Referring now to FIG. 2 , there is shown a second application of the expanded PVC foam methods of the present invention. As illustrated, the expanded PVC foam materials may be formed as letters 20 , 22 , 24 (as shown), numbers, figurines, and other objects for placement upon a non-porous surface 26 . Along these lines, it is contemplated that the methodology of the present invention can be utilized as a teaching aid, and may be particularly well suited for use with dry-erase surfaces that are extensively utilized and well-known in the art. It is likewise contemplated that the expanded PVC foam may be utilized as toys and include decorative designs, as per common felt boards using felt characters and the like, to create play scenes or art projects that can also be configured to be layered or stacked upon itself or one another. It is also contemplated that such expanded PVC foam can be utilized in conjunction with printed or written literary works or books that possess non-porous surfaces, as a teaching aid or game to position and hold in place shapes including animals, letters, numbers, designs, figures, and other decorative items, which can then be removed and repositioned upon various pages or sections of the book or printed or written literary work. Likewise, the expanded PVC foam can also be painted, directly printed upon, and/or over-laminated or decorated with a wide variety and combination of printed graphics, stickers, materials, glues, paint markers, pigments, glitter, and other craft items
[0022] Additional modifications and improvements of the present invention may also be apparent to those of ordinary skill in the art. Thus, the particular combination of parts and steps described and illustrated herein is intended to represent only certain embodiments of the present invention, and is not intended to serve as limitations of alternative devices and methods within the spirit and scope of the invention.
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A method of utilizing an expanded polyvinylchloride (PVC) foam having cohesive and high static-friction properties to attach, hang, display, hold or adhere one or more lightweight objects, decorative items and/or works of art, in a selectively positionable and re-positionable fashion. The methods of the present invention are particularly useful as toys and craft materials, as well as for use in hanging objects, documents, and decorative items as an alternative to the use of magnets, glue, adhesives or other means known in the art.
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BACKGROUND OF THE INVENTION
This invention relates to an improvement in polymeric fatty acid polyamides useful in the flexographic ink industry, to provide products which will comply with environmental protection standards. The improvement lies in the use of acid termination and a sufficient amount of unsaturated monomeric fatty acids to provide a molecular weight product which will permit relatively high solids levels and reduced solvent emission while maintaining good ink varnish properties.
Flexographic inks are solvent based inks applied by rollers or pads to flexible sheets of plastic foil and paper. It is necessary that flexographic ink binders be found which will have certain properties. The practical aspects of the use of these ink resins and the inks derived therefrom require that the polyamide resin be soluble in alcohol solvents, and such solubility must be attained without sacrificing toughness, adhesion and gloss.
U.S. Pat. No. 3,253,940 was one solution to provide greatly improved solubility in alcoholic solvents, particularly ethanol. This was accomplished through the use of relatively short chain or lower aliphatic monobasic acids in the preparation of polymeric fat acids polyamides of diamines such as ethylene diamine. Illustrative of such lower monobasic acids were those having up to 5 carbon atoms such as acetic acid, propionic acid, butyric acid and the like. In U.S. Pat. No. 3,224,893 the hydroxy monocarboxylic acids were employed in such polymeric fat acid polyamides. Varnishes of the polyamides of these patents in alcohol solvents were on the order of 35% by weight non-volatile solids.
The foregoing provided resins which could be employed with the usual alcoholic solvents. However, as environmental solutions were sought, efforts were made to reduce emissions such as those from the volatile alcohol solvents. One means of reducing the emission was to provide water reducible polymeric fat acid polyamides as illustrated in U.S. Pat. No. 3,776,865. As disclosed therein, this was achieved by acid termination of the polymeric fat acid polyamides employing an acid component of the polymeric fat acid and another co-dicarboxylic acid and an amine component comprising isophorone diamine alone or in admixtures with conventional diamines such as the alkylene diamines, i.e. ethylene diamine. Acid termination was achieved by employing about 50-75 amine equivalents per 100 carboxyl equivalents. Varnishes of these resins in an alcohol solvent such as n-propanol on the order of about 40% nonvolatile solids are disclosed.
Another U.S. patent, U.S. Pat. No. Re. 28,533 dealing with polymeric fat acid polyamides employing lower aliphatic monobasic acids, such as acetic and propionic, with certain amine combinations disclosed a few solubilities in ethanol up to 60% percent though many were 50% or below.
As environmental standards have become more and more stringent, efforts have continued to provide resins which comply with such standards. High solids varnishes on the order of 55-60%, and preferably above 60%, which when formulated into pigmented inks will meet such solvent emission standards which are desired in order to reduce solvent emissions. The development of lower molecular weight resins will provide for higher solids varnishes. However, this must be accomplished without significant effect on other properties required for flexographic ink use. Such requirements generally include:
(a) good solubility in ink varnish-high solids p1 (b) very low viscosity at 60% solids
(c) gel resistance
(d) toughness--non-tacky
(e) adhesion
(f) gloss
BRIEF SUMMARY OF THE INVENTION
It has now been discovered that polymeric fat acid polyamides which are suitable for providing high solids varnishes for flexographic inks can be prepared which will comply with current standards of reduced solvent emission, while retaining the properties necessary otherwise for flexographic ink applications. Such polyamides are those prepared from polymeric fat acids and diamines which include in the acid component an unsaturated fatty acid monomer and which employ relative amine and carboxyl amounts so as to provide an acid terminated product having an acid value in the range of 8-20 and preferably in the range of 10-15.
These products can be employed in alcoholic ink varnishes at levels of 60% solids or higher while maintaining good overall ink properties including viscosity, softening point, color and gel resistance.
DETAILED DESCRIPTION
As indicated, the present invention relates to certain acid terminated polymeric fat acid polyamides which are suitable for providing high solids varnishes from which flexographic inks can be prepared which will comply with current standards for reduced solvent emission.
The polyamides of the present invention are prepared by reacting (a) an acid component comprising a polymeric fat acid and a mixture of monocarboxylic acids in which a low aliphatic monobasic acid is employed in admixture with an unsaturated monobasic higher fatty acid with (b) an amine component comprising a mixture of a short chain diamine with a longer chain diamine, and in which the acid component is employed in excess so as to provide an acid terminated product. By acid terminated is meant the resins have a relatively high acid value or number in relation to the amine value. In order to provide the properties of the present invention, the resins should have an acid value in the range of 8-20 and preferably 10-15. The amine value will be about 2, i.e. within the range of about 1.7-2.5. Such values are achieved by employing about 0.92-0.96 amine equivalents per acid equivalent or about 92-96 amine equivalents for 100 acid equivalents or an acid to amine ratio of about 1.04 to 1.09. Preferably about 94 equivalents of amine are employed with 100 acid equivalents for a preferred acid to amine equivalents ratio of about 1.06.
Reaction conditions for the preparation of the polyamide resins may be varied widely. Generally the reaction is carried out at a temperature within the range of about 140°-250° C. Preferably the reaction is carried out at about 200° C. The time of reaction may also be varied widely and will depend somewhat on temperature. Normally a time period of 2 to 8 hours after reaching the selected temperature is required. The preferred time of reaction is about 3 hours. A typical set of reaction conditions is 205° C. for a period of 2-3 hours. Vacuum may be applied if desired to withdraw volatile by-products and to keep the resin mixture from contact with air which may cause darkening. An inert gas may also be employed to avoid contact with air. Typically the reaction mixture will be heated at the lower temperatures initially to avoid any volatilization and loss of the short chain monobasic acid employed, after which the temperature is raised to the higher reaction temperature. Thus, it is common to heat at about 140° C. for about 1 hour followed by raising the temperature to about 205° C. and reacting for about 1.5-3 hours.
The low aliphatic monobasic acids of the present invention are those of the general formula RCOOH, wherein R is hydrogen or an aliphatic radical of from 1 to 4 carbon atoms. Acids contemplated within the scope of this invention are formic acid, acetic acid, propionic acid, butyric acid, and the like. From a standpoint of physical properties, availability, and economics, acetic acid and propionic acid are the preferred acids of the present invention.
The unsaturated higher fatty acids employed in this invention are those having from 12-22 carbon atoms, more desirably those with 16-20 carbon atoms. The 18 carbon atom acids such as oleic, linoleic and linolenic are the preferred acids, including mixtures thereof, such as the mixture of oleic and linoleic found in tall oil fatty acids.
The polymeric fat acids are well known and commercially available products. The polymeric fat acids which may be employed in preparing the polyamides are those resulting from the polymerization of drying or semi-drying oils or the free fat acids or the simple alcohol esters of these fat acids. The term "fat acids" is intended to include saturated, ethylenically unsaturated and acetylenically unsaturated naturally occurring any synthetic monobasic aliphatic acids containing from 8-24 carbon atoms. The term "polymeric fat acid" refers to polymerized fat acids. The term "polymeric fat radical" refers to the hydrocarbon radical of a polymerized fat acid, and is generic to the divalent, trivalent, and other polyvalent hydrocarbon radicals of dimerized fat acids, trimerized fat acids and higher polymers of fat acids. The divalent and trivalent hydrocarbon radicals are referred to herein as "dimeric fat radical" and "trimeric fat radical" respectively.
The saturated, ethylenically unsaturated, and acetylenically unsaturated fat acids are generally polymerized by somewhat different techniques, but because of the functional similarity of the polymerization products, they all are generally referred to as "polymeric fat acids".
The ethylenically and acetylenically unsaturated fat acids which may be polymerized and their method of polymerization are described in the above mentioned U.S. Pat. No. 3,157,681. The saturated fat acids are generally polymerized by somewhat different techniques than those described in U.S. Pat. No. 3,157,681, but because of the functional similarity of the polymerization products, they are considered equivalent to those prepared by the methods described as applicable to the ethylenically and acetylenically unsaturated fat acids.
Reference has been made hereinabove to the monomeric, dimeric and trimeric fat acids present in the polymeric fat acids. The amounts of monomeric fat acids, often referred to as monomer, dimeric fat acids, often referred to as dimer, and trimeric or higher polymeric fat acids, often referred to as trimer, present in polymeric fat acids may be determined analytically by conventional gas-liquid chromatography of the corresponding methyl esters. Another method of determination is a micromolecular distillation analytical method. This method is that of R. F. Paschke et al., J. Am. Oil Chem. Soc., XXXI (No. 1), 5, (1954), wherein the distillation is carried out under high vacuum (below 5 microns) and the monomeric fraction is calculated from the weight of product distilling at 155° C., the dimeric fraction calculated from that distilling between 155° C. and 250° C., and the trimeric (or higher) fraction is calculated based on the residue. Unless otherwise indicated herein, the gas-liquid chromatography (G.L.C.) method was employed in the analysis of the polymeric fat acids employed in this invention. When the gas-liquid chromatography technique is employed, a portion intermediate between monomeric fat acids and dimeric fat acids is seen, and is termed herein merely as "intermediate", since the exact nature thereof is not fully known. For this reason, the dimeric fat acid value determined by this method is slightly lower than the value determined by the micromolecular distillation method. Generally, the monomeric fat acid content determined by the micromolecular distillation method will be somewhat higher than that of the chromatography method. Because of the difference of the two methods, there will be some variation in the values of the contents of various fat acid fractions. Unfortunately, there is no known simple direct mathematical relationship correlating the value of one technique with the other.
Typical compositions of commercially available polymerized fatty acids based on unsaturated C 18 fat acids are:
C 18 monobasic acids 5-15% by weight;
C 36 dibasic acids 60-80% by weight;
C 54 (and higher) tribasic acids 10-35% by weight.
The products employed in this invention are those in which the dimeric fat acid content (C 36 dibasic acid) is between 65-75% with about 70% being preferred. The monomeric fat acid content will be about 8 to 12%, preferably about 10 and the trimeric (and higher) between about 10 to 16, preferably about 12%. Any intermediate as noted above will be below 8% and typically at about 6%.
The acid component of the present invention will accordingly be composed as follows:
______________________________________Acid Component - 100 equivalents Eq. %______________________________________(a) Polymerized fatty acids 45-55(b) Unsaturated fatty acid 15-30(c) Short chain monobasic acid 20-35Carboxyl equivalent percent 100______________________________________
The polymerized fatty acids will include the residual monomeric monobasic acids as noted in the typical composition of commercially available products above. In the course of polymerization the monomeric acid is modified and is commonly referred to as an "isostearic" acid. The unsaturated fatty acid, component (b) above does not include those acids and the equivalents amount indicated is added unsaturated fatty acid.
As noted earlier, the amine component is a mixture of a short chain diamine such as an alkylene diamine having 2-3 carbon atoms, i.e. ethylene diamine with a longer chain diamine such as an alkylene diamine having 6-10 carbon atoms, i.e. hexamethylene diamine with the short chain diamine comprising more than 50% of the amine equivalents in the amine component. The amine component will accordingly be composed as follows:
______________________________________Amine Component - 100 equivalents Eq. %______________________________________(a) Short chain diamine 50-60(b) Long chain diamine 40-50Amine equivalent percent 100______________________________________
In the examples to follow, the viscosity is the melt viscosity in centipoises (p) measured in a Brookfield Thermosel viscosimeter in accordance with the operating procedures therefrom and is measured at 220° C. Softening points (melting point) of the polyamide resin of the invention were measured by conventional "ball and ring" melting point determination, ASTM method E28-58T.
Color was determined by Gardner color of a 40% non-volatiles solution in the solvent designated. By amine value is meant the number of milligrams of KOH equivalent to the free amine groups in one gram of sample. By acid value is meant the number of milligrams of KOH equivalent to the free acid or carboxyl groups in one gram of sample.
The polyamide resins were prepared according to the following typical procedure below.
TYPICAL POLYAMIDE RESIN PREPARATION PROCEDURE
Employing an acid to amine ratio of 100/94 or 1.06, the acid and amine reactants are charged to a reactor along with an anti-foamant (Dow Corning anti-foam agent) and less than 1% of H 3 PO 4 (85% solution) as a catalyst. The reactants are heated to a temperature of 140° C. and held at this temperature for one hour before being raised to a temperature of 205° C. at which it is held for 1.5 hours. Vacuum of about 15 mm. is applied for 0.5 hours at the 205° C. after which the temperature is reduced and butylated hydroxy toluene (BHT) as an antioxidant is added prior to discharge of the polyamide resin product.
In the following examples, which illustrate the invention in detail, all percentages and parts are by weight unless otherwise indicated. The polymerized fatty acid employed was polymerized tall oil fatty acids (VERSADYME 204) having the following analysis:
______________________________________Saponification Value (S.V.) 198.5Acid Value (A.V.) 189.2Thermosel Viscosity (25° C.) 54.5 poisesColor (Gardner - no solvent) 7+Fe 3.7 ppmP 25 ppmS 44 ppmIodine Value 99.9% Monomer (M) 10.9% Intermediate (I) 5.3% Dimer (D) 71.1% Trimer (T) 12.6______________________________________
EXAMPLE 1
A polyamide resin was prepared following the typical procedure set forth earlier above with the following materials:
______________________________________ Weight Equivalent grams % %______________________________________(a) Polymerized tall oil fatty 269.57 53.9 50.2 acids (VERSADYME ® 204)(b) Monomeric unsaturated tall 90.43 18.1 16.8 oil fatty acids (ALIPHAT ® 44A)(c) Propionic acid (PA) 46.54 9.3 33.0(d) Ethylene diamine (EDA) 31.34 6.3 54.1(e) Hexamethylene diamine 62.12 12.4 39.9 (HMDA) 70% aqueous solution)______________________________________
After the cook or reaction schedule at 205° C. was completed, the temperature was reduced, 5 grams of BHT was added and the product discharged.
The product had the following analysis and properties:
______________________________________Acid Value 12.2Amine Value 1.7Softening Point (B & R) 117° C.Viscosity at 160° C. (Thermosel) 0.51 pColor (Gardner) 6______________________________________
EXAMPLE 2
In the same manner as Example 1, a polyamide resin was prepared for the following reactants:
______________________________________ Weight Equivalent grams % %______________________________________VERSADYME ® 204 247.5 49.50 49.4ALIPHAT ® 44A 133.7 26.74 26.6PA 31.6 6.32 24.0EDA 29.2 5.84 54.1HMDA 58.0 11.60 39.9______________________________________
The resulting product has the following analysis and properties:
______________________________________Acid Value 12.1Amine Value 2.2Softening Point (B & R) 105° C.Viscosity at 160° C. (Thermosel) 0.44 pColor 6______________________________________
The resin of Example 1 was dissolved in various solvent mixtures and the Gardner Holdt viscosities observed along with the gel or gellation properties by subjecting varnishes to a conventional freeze/thaw test (4° C./25° C.), measured in minutes. The following examples illustrate the properties in the solvent solutions at high solids levels.
EXAMPLE 3
In this example the solvent system studied was methanol (MTOH), ethanol (ETOH) and hexane (H). The systems, Gardner Holdt viscosity and gel properties are set forth in the following Table I.
TABLE I__________________________________________________________________________Samples and Solvent CompositionSolvents 1 2 3 4 5 6 7 8 9 10__________________________________________________________________________MTOH 50 25 -- 50 25 -- 50 25 -- 100ETOH -- 25 50 25 50 75 50 75 100 --H 50 50 50 25 25 25 -- -- -- --Pounds/gallon (#1 gal) 6.0 6.0. 6.0 6.3 6.3 6.3 6.6 6.6 6.6 6.6Gardner Holdt Viscosity (GHV)60% Solids A2+ A1 -- A1- A1+ A-B A1+ A- A+ A2+55% solids A3-4 A2-3 A2+ A2-3 A2+ A1- A1-2 A1-2 A1 A2-3Gel Test (GT) - minutes60% solids 23/26 >100 R.T.GEL 23/26 >100 >100 >100 >100 >100 38/3955% solids 6/10 24/26 >100 10/14 22/25 >100 35/37 77/78 >100 29/31__________________________________________________________________________
EXAMPLE 4
in the same manner as Example 3 samples were evaluated employing solvent systems of methanol, hexane and n-propanol (NPA). The results are as shown below in Table II.
TABLE II__________________________________________________________________________Samples and Solvent Composition 11 12 13 14 15 16 17 18__________________________________________________________________________MTOH 25 -- 50 25 -- 50 25 --NPA 25 50 25 50 75 50 75 100HEXANES 50 50 25 25 25 -- -- --#1 gal) 6.0 6.0 6.3 6.3 6.4 6.7 6.7 6.7GHV - 60% AL+ -- A1+ A+ -- A D+ --55% A2 -- A2- A1- A- A1- A- B-CGT - 60% >100 R.T.GEL 20/23 >100 R.T.GEL 45/47 >100 R.T.GEL55% 28/31 R.T.GEL 8/12 24/26 >100 25/27 34/35 >100__________________________________________________________________________
EXAMPLE 5
In this example the solvent compositions employed were methanol, ethanol and ethyl acetate (EAC). The results are shown in Table III below.
TABLE III______________________________________Samples and Solvent Composition 19 20 21 22 23 24______________________________________MTOH 50 25 -- 50 25 --ETOH -- 25 50 25 50 75EAC 50 50 50 25 25 25#/gal 7.0 7.0 7.0 6.8 6.8 6.8GHV - 60% A1-2 -- -- A1- A1-A --55% A3+ A2- -- A2-3 A2 A1-2GT - 60% >100 R.T. R.T. >100 >100 R.T. GEL GEL GEL55% >100 >100 R.T. 36/38 >100 >100 GEL______________________________________
EXAMPLE 6
In this example the solvent compositions were methanol, n-propanol and ethyl acetate. The results are shown in Table IV below.
TABLE IV______________________________________Samples and Solvent Composition 25 26 27 28 29______________________________________MTOH 25 -- 50 25 --NPA 25 50 25 50 75EAc 50 50 25 25 25#/gal. 7.0 7.1 6.8 6.9 6.9GHV - 60% -- -- A1+ A --55% A2- -- A2- A1- C-D (THIXO)GEL - 60% R.T. R.T. 57/60 >100 R.T.GEL GEL GEL55% >100 R.T. 23/26 >100 >100 GEL______________________________________
EXAMPLE 7
The resin of Example 2 was formulated into compliant, white flexographic inks as follows:
______________________________________ SampleComponent (#/gal) A B______________________________________Titanium dioxide (34.2) 50.00% 50.00%Resin of Ex. 2 (8.0) 28.10% 29.40%MTOH (6.6) 10.95% 10.3%ETOH (6.6) 10.95% --H (5.5) -- 10.3% 100.00% 100.00%______________________________________
From the foregoing examples, it can be seen that varnishes of the resin can be prepared at high solids levels for flexographic inks. Ethanol is one of the preferred solvents commonly employed with flexographic inks and good results are seen in sample 9 of Table I. The addition of methanol or hexane, particularly with the use of n-propanol (in place of the ethanol) is desirable. The use of methanol along with ethyl acetate also provides desirable results. The preferred solvents are the alcohol solvents such as the lower aliphatic hydrocarbon alcohols, alone or in admixture, i.e. the alkanols containing from 1-5 carbon atoms such as methanol, ethanol and propanol which are the more preferred. The alcohols can be employed admixed with other cosolvents having an evaporation rate substantially the same as the base alcohol solvent employed. Illustrative cosolvents are the alkyl (1-5 carbon) acetates and typical hydrocarbon solvents such as the aliphatic or cyclo aliphatic hydrocarbons having from 6-12 carbon atoms.
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Polymeric fat acid polyamides are disclosed useful in the flexographic ink industry, to provide products which will comply with environmental protection standards. The improvement lies in the use of acid termination with acid values of 8-20 and a sufficient amount of unsaturated monomeric fatty acids to provide a molecular weight product which will permit relatively high solids levels and reduced solvent emission while maintaining good ink varnish properties.
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FIELD OF THE INVENTION
The invention relates to a tensioner, and more particularly, to a tensioner comprising a resilient member within which a base first portion and an arm second portion are cooperatively disposed.
BACKGROUND OF THE INVENTION
In numerous applications where endless power transmission devices are employed it is often desirable or necessary to control the tension in such devices during movement thereof around associated sheaves, pulleys, sprockets or the like, to assure optimum operating efficiency.
Numerous tensioning devices such as belt tensioning devices have been proposed heretofore and most of these devices employ metal spring devices, hydraulic devices, or pneumatic devices to provide the tensioning action whereby such devices are comparatively complicated and expensive and require considerable maintenance. Accordingly, there is a need for a simple and inexpensive tensioning apparatus capable of providing reliable performance over an extended service life.
Representative of the art is U.S. Pat. No. 3,975,965 (1976) which discloses a tensioning apparatus for an endless power transmission device is provided and utilizes the elastic properties of an elastomeric material to provide the tensioning action and such apparatus is supported adjacent the endless power transmission device to be tensioned and has components thereof operatively associated with the elastomeric material and with the device.
What is needed is a tensioner comprising a resilient member within which a base first portion and an arm second portion are cooperatively disposed. The present invention meets this need.
SUMMARY OF THE INVENTION
The primary aspect of the invention is to provide a tensioner comprising a resilient member within which a base first portion and an arm second portion are cooperatively disposed.
Other aspects of the invention will be pointed out or made obvious by the following description of the invention and the accompanying drawings.
The invention comprises a tensioner comprising a base comprising a first portion, an arm comprising a second portion, the arm pivotally connected to the base, a pulley journalled to the arm, a resilient member compressively disposed between the first portion and the second portion, the resilient member comprising a gap within which the first portion and the second portion are disposed, and the resilient member comprising a bore, the bore engaging the arm.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention, and together with a description, serve to explain the principles of the invention.
FIG. 1 is a perspective view of the tensioner.
FIG. 2 a is a perspective view of the base.
FIG. 2 b is a side view of the base.
FIG. 3 is a perspective view of the resilient member.
FIG. 4 a is a perspective view of the arm.
FIG. 4 b is a perspective bottom view of the arm.
FIG. 5 is a perspective view of the sleeve.
FIG. 6 is a perspective view of the retainer.
FIG. 7 is an exploded view.
FIG. 8 is a bottom view of the tensioner arm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a perspective view of the tensioner. Tensioner 100 comprises a base 10 . Arm 20 is pivotally connected to base 10 . Disposed between arm 20 and base 10 is resilient member 30 . Resilient member 30 biases arm 20 against a belt (not shown) in order to apply a force (load) to the belt.
A pulley 40 is journalled to the arm 20 . The belt (not shown) engages a surface 41 of pulley 40 . Pulley 40 rotates about bolt 42 on bearing 43 .
Arm 20 pivots about post 11 . Retainer 50 is used to retain arm 20 in proper operational connection to base 10 and resilient member 30 . A low-friction sleeve 60 is disposed between arm 20 and post 11 .
FIG. 2 a is a perspective view of the base. Base 10 comprises a post 11 which extends therefrom. Portion 12 extends upward from base 10 into recess 13 . Portion 12 is not connected to the length of post 11 so that portion 12 does not interfere with skirt 22 or sleeve 60 .
Tab member 14 projects from base 10 to engage a mounting surface, such as an engine block (not shown). Tab member 14 prevents rotation of base 10 during operation and assures proper orientation during final assembly on a mounting surface.
FIG. 2 b is a side view of the base. Gap 120 is disposed between portion 12 and post 11 to allow clearance for skirt 22 and sleeve 60 .
FIG. 3 is a perspective view of the resilient member. Resilient member 30 substantially describes a “C” shape. As such resilient member 30 comprises a gap 31 which cooperatively engages portion 12 in base 10 and portion 21 . Resilient member further comprises a bore 32 which engages arm skirt 102 . Resilient member 30 also engages base 10 within recess 13 and arm 20 . Resilient member 30 further comprises projections 33 which engage arm 20 and base 10 . Projections 33 are used to bias arm 20 in to the proper operating position, and thereby maintain a proper pulley position with respect to a belt (not shown).
Resilient member 30 comprises any known natural or synthetic rubber material, or suitable combination of the two. The spring rate of resilient member 30 may be selected by changing the thickness, height or durometer of the material.
FIG. 4 a is a perspective view of the arm. Portion 21 extends from arm 20 so as to extend within gap 31 in resilient member 30 . Portion 21 engages resilient member 30 so as to compress resilient member 30 .
FIG. 4 b is a perspective bottom view of the arm. Skirt 22 extends toward base 10 . Bore 32 of resilient member 30 engages skirt 22 . See FIG. 8 .
FIG. 5 is a perspective view of the sleeve. Sleeve 60 is cylindrical in shape. Sleeve 60 extends between arm 20 and post 11 . Sleeve 60 is a low friction material in order to facilitate movement of arm 20 . In an alternate embodiment, sleeve 60 may comprise a predetermined coefficient of friction with the arm 20 whereby a movement of arm 20 is damped, so as to damp arm oscillations.
FIG. 6 is a perspective view of the retainer. Retainer 50 engages post 11 to hold arm 20 and resilient member 30 in proper position in base 10 .
FIG. 7 is an exploded view. In operation, a belt (not shown) is engaged with pulley 40 . As a belt tension changes the arm 20 pivots about base 10 . Since resilient member 30 is captured between portion 12 and portion 21 , any pivotal movement of arm 20 whereby a belt tension (load) is increased is resisted through compression of resilient member 30 . This is because movement of arm 20 causes portion 21 to move toward portion 12 in recess 13 .
In a predetermined operating condition, for example, in an “unloaded” position portion 12 is held in “back to back” contact with portion 21 by resilient member 30 .
Dust covers 44 protect bearing 43 from debris.
FIG. 8 is a bottom view of the tensioner arm. In this view portion 21 is in contact with portion 12 . Bore 32 of resilient member 30 is engaged about skirt 22 . Portion 12 and portion 21 are each disposed in resilient member gap 31 . Sleeve 60 is disposed radially inward of skirt 22 , namely, sleeve 60 is between skirt 22 and post 11 . Skirt 22 and sleeve 60 are disposed within gap 120 in order to pivotally engage post 11 .
Although a form of the invention has been described herein, it will be obvious to those skilled in the art that variations may be made in the construction and relation of parts without departing from the spirit and scope of the invention described herein.
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A tensioner comprising a base comprising a first portion, an arm comprising a second portion, the arm pivotally connected to the base, a pulley journalled to the arm, a resilient member compressively disposed between the first portion and the second portion, the resilient member comprising a gap within which the first portion and the second portion are disposed, and the resilient member comprising a bore, the bore engaging the arm.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No. 13/068,328, filed May 9, 2011, titled Apparatus and Method for Communication Security in a Nationwide Wireless Network. The application Ser. No. 13/068,328 is a continuation of application Ser. No. 11/458,208, filed Jul. 12, 2006, titled “Systems and Methods of Ambiguity Envelope Encryption Scheme and Applications, of Tara Chand Singhal, now issued patent U.S. Pat. No. 7,688,976 and is continuation of application Ser. No. 12/386,197, filed Apr. 15, 2009, which is a divisional of application Ser. No. 11/458,208.
[0002] This application also claims priority on Provisional Application Serial Number U.S. 60/666,941, titled “Method and apparatus for wireless security using Jitter-key based ambiguity envelope and a wireless access point authentication system” filed on Mar. 31, 2005, by Tara Chand Singhal. The contents of the Provisional Application Ser. No. 60/666,941 are incorporated herein by reference.
FIELD OF THE INVENTION
[0003] The present invention is directed to systems and methods for security in a nationwide wireless network with wireless routers, where the wireless routers are equipped with the ability to generate, deliver and use a random seed for communication security.
BACKGROUND
[0004] In prior art encryption schemes a standard well-known encryption algorithm is used. The algorithm may be initialized with a seed value. This algorithm is present at both ends of a transmission path such as a wireless network.
[0005] There is an encryption key, which is randomly generated and is defined by the number of bits such as, 56 bits, 64 bits, 128 bits, 192 bits, 256 bits, 384 bits or 512 bits. The longer the key in bits, more difficult it is to break it by brute force. The key needs to be also present at both ends of the transmission path. Hence once a key is created it is exchanged between both the ends of the transmission path that is used for the wireless transmission.
[0006] At one end of the transmission path, a plain text is entered into the encryption algorithm that uses the encryption key to encrypt the file that is made up of data packets and at the other end the same key is then used to decrypt the message to get back the plain text.
[0007] In this scheme of encryption since the algorithm is standard, great care is exercised in protecting the key, in how the key is stored and safe guarded while in storage, how it is distributed or exchanged, how it is safeguarded during the distribution or exchange process, and how it is changed or re-keyed on a periodic basis such as every month on highly secure systems in military and perhaps once a year in other systems. When a wireless transmission path is used, it is easier for hackers to break the key.
[0008] Hence the security of transmissions depends upon the key and key strength in bits. However, with the increase in computer power and use of wireless as well, it has become easier to break such keys. For a while, 128 bits was considered a strong key. However, it is not now and 256 bit keys have begun to be used.
[0009] Use of wireless technology has grown in many applications. These wireless technologies use digital transmission of data packets. A digital data packet has a header and a data body. The data in the body is encrypted during transmission.
[0010] One of the popular uses of wireless transmission has been and is between a laptop computer and a wireless access point (WAP) or router to a company network or the Internet. Other uses have been between the sales terminal of a business and their central server.
[0011] Such WAPs are commonly used by businesses and in offsite locations such as airports, hotels and coffee shops as well as in homes. These uses typically operate for a few hundred meters, based on the strength of the transmission. To facilitate wide spread use and manufacture of such devices, various industry standards have been developed, such as 802.11b and 802.11g.
[0012] Another use of wireless that is emerging is the use of Bluetooth® (Bluetooth), where cell phones equipped with Bluetooth capability communicate to a wireless earpiece. Still another use is in military application such as in ad hoc mobile wireless networks in a theatre of operation. Cellular phones are another prominent use of wireless networks.
[0013] It has become well known, that others may capture and decipher private wireless transmissions to steal private information. It has become known that in spite of encryption, the hackers have been successful in stealing private transmissions. A standard called wired equivalent privacy (WEP) has been developed for these wireless transmissions. The WEP is designed to deliver the same encryption as available on a wired transmission; hence the name wired equivalent privacy.
[0014] The weaknesses that have been demonstrated are: (i) to be able to capture transmissions from very great distances using special telescopic antennas. For example, in tests conducted, wireless transmissions between laptop and WAPs, that from a user point of view are limited a few hundred feet, can be captured from as far away as 11 miles using a special antenna. Wireless transmissions using Bluetooth that from a user perspective are good for 10 to 20 feet can be captured from as far away as a city block. (ii) One of the ways of stealing private transmission have been via specially equipped roving van, which rove around city blocks to find and capture transmissions. (iii) Defeating the authentication between the user and the wireless access point and setting up rogue wireless access points between the user and the real wireless access points that redirect traffic to a spoofed access point. And (iv) breaking the encryption key, that is used for encryption. Having access to samples of plain text and encrypted text, an encryption key such as a 128-bit key is easily broken. Hence, even though the wireless transmissions are encrypted, they are still compromised by hackers.
[0015] The ease with which the security of wireless transmission has been compromised has been demonstrated both by the information security personnel of banks as well as the special agents of FBI in Information System Security Association local chapter security briefings.
[0016] Hence, it is a primary objective of this invention to have a different form of encryption scheme that does not rely on the security of wireless keys to provide security for wireless transmissions.
[0017] It is also an objective of this invention to have encryption scheme that does not rely on the security of encryption keys for providing networks that use both wireless and wired networks.
SUMMARY
[0018] This invention describes Ambiguity Envelope (AE), a different form of encryption technology specifically developed for security of wireless transmissions but may be used for wired transmission and a combination of wired and wireless networks locally or nationally.
[0019] In AE an ambiguity envelope is created over the transmission path of data packets, so that no specific encryption key, as in prior art, is used. Instead, random-variant-keys are used that are distinct and separate for each packet and may also be distinct and separate for each incoming and outgoing packet.
[0020] AE uses prior art encryption algorithms and prior art encryption keys and provides systems and methods for random-variant-keys that are derived from and used in place of the prior art encryption keys.
[0021] These random-variant-keys have no mathematical relationship to each other or to the prior art encryption keys. The random-variant-keys are not created, stored at either end, or exchanged with each end of transmission. The random-variant-keys are only created at the time of the actual use for encrypting or decrypting a data packet and then discarded after one time use.
[0022] Because the random-variant-keys are neither stored, nor transmitted by any method, there are no keys to create, secure, safeguard, distribute, destroy and recover as in prior art. Because random-variant-keys are indeterminate based on multiple degrees of randomness, as described later, the random-variant-keys cannot be computed. Therefore, random-variant-keys used in transmission cannot be determined. Thus AE provides wireless transmission security that does not have the deficiencies of the prior art as described in the background section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts. The drawings are:
[0024] FIG. 1 is a block diagram that illustrates the encryption scheme of the current invention.
[0025] FIG. 2 is a detailed block diagram that illustrates the encryption scheme of the current invention.
[0026] FIG. 3A-B are block diagrams that illustrate the operation of the encryption scheme of the current invention.
[0027] FIG. 4A is a block diagram that illustrates the application of this encryption scheme in a national wireless network of this invention.
[0028] FIG. 4B is a block diagram that illustrates the operation of the application of this encryption scheme in a national wireless network of this invention.
[0029] FIG. 5 is a block diagram that illustrates the operation of the application of this encryption scheme between wireless devices such as cell phones.
[0030] FIG. 6 is a block diagram that illustrates the operation of the application of this encryption scheme in a mobile ad hoc wireless network.
[0031] FIG. 7 is a block diagram that illustrates the use of optical means to transfer BRNs between devices that use the encryption scheme of this invention.
DESCRIPTION
[0032] With reference to FIG. 1 , this invention has an Ambiguity Envelope (AE) security system 10 , which has a bounded random number generator function 16 , an ambiguity envelope function 12 and a jitter function 14 . The output of the bounded random number generator function 16 is called bounded random numbers or BRNs 17 . BRNs 17 are input to the ambiguity envelope function 12 . The AE function 12 using a shuffling and pairing sub-function 22 , and an envelope creating sub-function 24 creates an ambiguity envelope 13 . An envelope offset sub-function 26 uses envelope 13 and when inputted packet number 22 , outputs an envelope offset 27 , which is input to the jitter function 14 . The jitter function 14 using the input of the ambiguity envelope offset 27 and the prior art key 20 outputs random-variant-keys 18 .
[0033] The AE implementation uses a small memory and processing throughput footprint that rides over the existing prior encryption schemes thus making the AE implementation relatively convenient in prior art encryption devices and prior art devices that embody embedded encryption mechanisms. Integrated circuits, firmware and components that facilitate use of AE may be manufactured and sold to manufacturers of wireless devices such as cell phones, wireless access points, and other devices.
[0034] With respect to upper part 60 of FIG. 2 , the system 10 uses prior art encryption scheme using encryption algorithm 42 , seed value 44 , plain text 46 and encryption key 20 over a prior art wireless network 40 .
[0035] As illustrated in lower part 62 of FIG. 2 , in AE 10 , the prior art encryption key 20 is jittered or randomly modified to create random-variant-keys 18 for each packet #X. The random-variant-key 18 is then what is used for each packet instead of the prior art key 20 . The random-variant-key 18 is like the prior art key 20 in every respect including the key length. The difference between the random-variant-keys 18 and the encryption key 20 is that the random-variant-keys 18 are randomly created variants of the encryption key 20 .
[0036] As shown, the random-variant key 18 is created by a Jitter function 14 to which is input, the prior art encryption key 20 , and the ambiguity envelope offset 27 . The offset 27 is output by the AE function 12 , when the AE function 12 is input the packet sequence #X 21 . The envelope 13 , which is used to compute the offset 27 is based on the BRNs 17 and the AE parameters 48 as described later.
[0037] In the AE function 12 , the packet sequence #X 21 is used to read an offset value 27 from the envelope 13 and is used by the jitter function 14 to create a random-variant-key for that packet number #X 21 .
[0038] The ambiguity envelope 13 has x-axis as packet sequence number and y-axis has as the amplitude or offset of the envelope. This offset value is read from the envelope for a given packet number and is used by the Jitter function 14 to create a random-variant-keys 18 for this packet. Hence, the random-variant-keys are different for every packet and is created at the time of use for one time use in the temporary memory and then discarded.
[0039] A time slice such as one second or some other time, in place of packet number 22 may also be used. The packet number is preferred as it is a recognized unique prior art mechanism to identify the order and sequence of transmission of packets between the two ends of transmission. However a time slice instead of packet may also be used provided the time system clocks at the ends of transmission are synchronized and can be relied upon.
[0040] With reference to FIG. 2 , the AE function 12 and Jitter function 14 are present at both ends of the transmission path. For illustration purposes, the line 40 divides the transmitting end 40 A and the receiving end 40 B.
[0041] The BRNs 17 and the AE parameters 48 enable the random variation of the prior art key 20 resulting in random-variant-keys 18 . The BRNs 17 are created at one end of the transmission path and then transferred to the other end by an out-of-band method depending upon the application as described later with reference to FIGS. 4 , 5 , 6 and 7 .
[0042] With reference to FIGS. 1 and 2 , AE parameters 48 determine how the BRNs 17 are transformed into an ambiguity envelope 13 using shuffling and pairing function 22 and a envelope creation function 24 . The offset function 26 outputs an offset 27 of the envelope 13 when input a packet sequence 21 . These functions 22 , 24 and 26 are described in more detail later and add or provide multiple degrees of random separation from the BRNs to the envelope itself. Thus knowledge of the BRNs 17 themselves does not provide knowledge or computation of the ambiguity envelope 13 . The AE parameters 48 may be unique and different for different classes of wireless devices that use encryption such as Wireless access point's network and cell phones.
[0043] With reference to FIGS. 1 and 2 , in a system of encryption for communication security that uses an encryption algorithm 42 and a pre-placed encryption key 20 , this invention provides a security function 10 that generates a sequence of random-variant-keys 18 one at a time, on a per packet basis in temporary memory of an encryption device from the pre-placed key 20 at the time of encryption and not before and uses these random-variants-keys 18 for encryption instead of the pre-placed key 20 and immediately thereafter discards the random-variant-keys 18 .
Bounded Random Number Generator Function 16
[0044] Prior art random generators of any type may be used to generate a sequence or set of random numbers of specified number of digits. When the random number is limited to a specified number of digits it may be called a bounded random number or a BRN. For example, if an up to 2 digit random number is derived from a larger random number generated from a prior art random number generator function it is a bounded random number.
[0045] The random numbers may be bounded to any number of digits depending upon the application. For some applications they may be single digit bounded and for some other applications they may be bounded to such as 2 or many more digits. Further, a sequence of such bounded random numbers is created. Such a sequence may have a short sequence of 6, or a medium sequence, or a long sequence that have many tens of bounded random numbers. A sequence that is even and of at least six numbers is preferred as is described later. These bounded random numbers are used for creating an indeterminate envelope as described later. The envelope is considered indeterminate having multiple stages or degrees of random separation from the BRNs themselves.
Ambiguity Envelope Function 12
[0046] This function has three sub-functions as described here. The input to the function 12 is the sequence of BRNs from the function 16 and the output is an ambiguity envelope offset 27 , which is input to the jitter function 14 . The three sub-functions are:
Shuffling and Pairing Sub-Function 22
[0047] This sub-function takes the BRNs 17 shuffles them, and then pairs them so that each pair may describe cycle time and amplitude parameters of a wave. As a simplified illustration, if there are six numbers, 12, 45, 56, 23, 67, 98 generated in that order by the BRN function 16 , then the shuffling function shuffles this sequence in one of many shuffles. An AE parameter 48 A may be used to define one of many shuffle approaches. The shuffled BRNs are then paired in three pairs. Another AE parameter 48 B may be used to define the pairing. The pairs then may be further shuffled to define which of the number of a pair represent the cycle time of the wave and which represents the amplitude. The output of this sub-function is a number of pairs. As a simplified illustration, when the BRNs are six in number, output of this function, are three pairs of numbers, where each pair represents the cycle time and amplitude of a wave. The three wave pairs from the six BRNs after the operation of this function may be (56, 98), (45,12), and (23,67) where the first number of the pair is cycle time and the second number is the amplitude.
Envelope Creation Function 24
[0048] In this function, each pair of BRNs is then mapped to a wave type such as a sine wave, or a square wave or a triangle wave. Again an AE parameter 48 C may define which one of many possible approaches to mapping may be used. The wave types are chosen to be a sinusoidal, a triangle and a square wave type. Other wave types may also be used but these wave types are preferred as they are defined by a pair of numbers that map to two of the BRNs and are distinct in their properties of how their amplitude on y-axis varies along the x-axis.
[0049] Once the mapping to the wave types is done, this function then takes the three waves and additively combines them into one envelope. By adding these wave types of different types results is an ambiguity envelope 13 . Optionally a phase value may be assigned to each of the waves before they are additively combined if one of the BRNs may be used to represent a phase value. In addition, a phase may be added to the entire envelope, where such a phase would be different for the sending and receiving ends of the transmission.
[0050] How the BRNs 17 may be converted to an ambiguity envelope 13 has been described. Many approaches in addition to the above may be used and are not ruled out. The shuffling, pairing and then shuffling within the pair that map to one of the wave types provide different types of random approaches to separate the envelope from the BRN itself. Mere knowledge of the BRNs themselves would make impossible the creation of the envelope. Alternatively the BRNs may be straight forward used to create an envelope without the use of shuffling, pairing and shuffling with in pairs as defined by the AE parameters 48 . However, it is believed that these functions add different types of randomness for the creation of the envelope from the BRNs and thus provide additional level or layer of security. Therefore, the compromise of the BRNs does not affect the security as provided by this invention in creating random-variant-keys 18 .
[0051] Furthermore, the ambiguity envelop 13 that results is indeterminate and could not have been duplicated by any means as it is a summation of different wave types, randomly selected, and used randomly assigned parameters from a random set of parameters. The ambiguity envelope does repeat but at a random cycle time. The cycle time of the envelope is based on the factorial of the cycle time of the three waves. For example, if the three cycle times are 56, 45 and 23, then the cycle time of the envelope would be a lowest number that is divisible by 56, 45 and 23. Hence the ambiguity envelope is indeterminate having been derived from the BRNs by a series of operations as described herein. The amplitude of the envelope 13 would randomly vary between the positive and negative values of maximum of sum of individual wave amplitudes. Hence the offset value 27 for a packer sequence number #X 21 may be positive or negative between these maximums or zero.
[0052] Given the same BRNs 17 at the two ends of the transmission and the same AE parameters 48 , the same ambiguity envelope can be created. There may be two envelopes at each end of the transmission, one for generating random-variant-keys for encrypting outgoing packets and one for generating random-variant keys for decrypting the incoming packets. These two different envelopes may use a different set of BRNs or use the same set of BRNs but add a different phase to the envelope, so that a different random-variant-key would result for the incoming packet and the outgoing packet, even if the packet sequence number is the same and even if the packet sequence number is different. In a real transmission the packet sequence numbers may be different as more packets may be transmitted in one direction than in the other direction. For example when the same BRNs are used at the two ends, the phase offset may be zero at one end and another number at the other end. For this offset, some of the numbers from the sequence of the BRNs themselves may be used.
[0053] Envelope Offset Function 26
[0054] This function, when input a value for an x-axis, computes a y-axis value from the ambiguity envelope. The x-axes value is a packet sequence number in a session of communication. The y-axis is an envelope offset which is input to the jitter function 14 . This function is input the packet sequence number at the time of the packet creation and outputs an offset value. The offset value from the envelope for a given packet sequence number maybe an integer, maybe an integer plus a fraction, or maybe positive or negative or zero. This offset may be used in a variety of random ways to provide random-variant-keys 18 as described in the jitter function 14 .
[0055] Jitter Function 14
[0056] The jitter function 14 transforms the y-axis offset of the envelope into a series of numbers and this series of numbers is used to alter the pre-placed key 20 to arrive at a random-variant-key 18 , where each y-axis offset yields a new random-variant-key.
[0057] The jitter function 14 may use one or a combination of techniques of, (i) the pre-placed key is altered by performing an operation such as bit reversal corresponding to the series of numbers, (ii) the pre-placed key is altered by performing an operation such as adding or subtracting the offset from the pre-placed key. Any number of possible approaches from the envelope offset maybe used to create random-variant-keys in addition to the two described above.
[0058] As a simplified illustration, using the first technique, if the offset is 329.7, the series of numbers derived from this offset may be 3, 2, 9, 32, 29, 39, 5, 11, and 14 by a combination of the numbers 3, 2, and 9. These bit numbers in the key may be flipped from a 0 to 1 or a 1 to a 0. As a simplified illustration, using the 2 nd technique, the offset number 329 may be added to the prior art key at the 7 th bit position from one end of the key. Other similar techniques that are derived from the offset value may be used. These techniques are embedded in the jitter function 14 that is present at both ends of the transmission. The technique that is used in a jitter function may be different for different classes of the devices that use the security function 10 . For example one technique may be used in cell phones and another technique may be used in the wireless access points of a network.
[0059] A third technique may also be used for creating random-variant keys 18 . This third technique may create two random-variant-keys for each packet that may be used as layers of keys for double encryption. For example, technique 1 may be used to create a random-variant-key 1 18 and technique 2 may be used to create a random-variant-key 2 18 A as shown in FIGS. 3B-1 and 3 B- 2 . Then key 1 may be used to encrypt a data packet and key 2 may be used to further encrypt the same data packet.
[0060] This technique provides an additional level of randomness in the generation of random-variant-keys and an additional layer of security. For a given packet even if brute force approach were attempted to break the random-variant-key for that packet alone, the plain text of the packet's data contents would not result and would not verify the accuracy of the random-variant-key.
Operational Steps
[0061] FIGS. 3 A and 3 B- 1 & 2 describes the operation of the security function 10 . As shown security function 10 of FIG. 1 , has three steps, 82 , 84 and 86 . Step 82 is a Bounded random Number (BRN) function. The Step 84 is an ambiguity envelope function. Step 86 or 87 , is a Jitter function.
Step 82
[0062] Step 82 , as in FIG. 3A is a bounded random number (BRN) generator function. It is used to create six two-digit numbers. Since, such numbers are commonly used in a lottery, the output of Step 82 , as such, may be named a lottery number. Hence Step 82 generates a lottery number made of six two-digit numbers. Where manual methods maybe used to copy a BRNs from one device to another device, the concept of lottery number makes it easier to humanly read, receive and enter into a device.
[0063] In this description, the terms AE coefficients, lottery number and BRN mean the same thing and may be used interchangeably. These are a set of bounded randomly generated numbers by a random number generator function. When they are limited in size such as one digit, 2 digit, etc, they are referred to as bounded random numbers. When they are bounded to 2 digits and are six in number they are referred to as a lottery ticket, as customarily, a lottery ticket has six two-digit numbers. However, depending upon the application the BRN may be longer numbers and may correspond to more than six numbers.
[0064] Step 82 is performed on one end of the two points of a wireless transmission path. Which end of the transmission link it is performed, how often it is performed or the BRNs are refreshed and how the BRNs are carried or conveyed over to the other end of the transmission path is illustrated later with reference to FIGS. 4 , 5 , 6 and 7 for different applications. Thus having the lottery number, AE coefficients or BRNs at both ends of the transmission now leads us to Step 84 .
Step 84
[0065] As shown in FIG. 3A , Step 84 has four sub-steps 1 to 4 . Optionally an AE flag 33 may be used to turn the features of security function 10 on or off in a given application.
[0066] In sub-step 1 , the AE function 12 takes the lottery number 17 and creates an ambiguity envelope 13 . A simplified representative envelope 13 is shown. The envelope 13 has an x-axis and y-axis. The x-axis is packet sequence number 21 and y-axis is amplitude or offset 27 for the packet sequence number 21 .
[0067] Three different AE parameters 48 may be used to quantify how the BRNs 17 may be transformed into an ambiguity envelope. The AE parameters may be, (i) Wave Pairs (WP), (ii) Wave Order (WO), and (iii) Wave Type (WT).
[0068] As an illustration, if the BRN is a set of six two digit numbers 24, 64, 23, 89, 72 44, then for example, WP may be 1, 6, 2, 4, 3, 5. This means that 1st and 6th number form a pair, 2 nd and 4 th number form a pair and 3 rd and 5 th number form a pair, so that the pairs that define a wave are (24, 44), (64, 89), and (23, 72). The WO defines in each pair, which number is cycle time and which number is amplitude. For example, WO may be, (23 is Cycle time and 44 is Amplitude), (64 is amplitude and 89 is cycle time) and (23 is amplitude and 72 is cycle time). The WT defines the type of each of the waves, such as, first pair represents a Triangle wave, second pair represents a Square wave, and third pair represents a Sine wave or even a Cosine wave.
[0069] These AE parameters take the original six randomly generated numbers and turn them into three waves, each with an amplitude and cycle time. Thus the lottery number yields three waves of different amplitudes, cycle times and different shapes or types based on the lottery number set of six numbers. Then these individual waves are additively combined to yield an ambiguity envelope 13 .
[0070] These steps of starting from the random bounded random numbers 17 and arriving at the ambiguity envelope 13 provide different types of randomness and break the chain of mathematical causation between the BRNs 17 and the ambiguity envelope 13 .
[0071] Having a different set of AE parameters 48 enables AE function 12 to be different from application to application or even among applications by assigning a version number to the AE function.
[0072] The ambiguity envelope would repeat after a number that is equal to factored number of multiplication of three cycle times. For example, if the cycle times of the three waves are 33, 67, 99, and since 99 is divisible by 33, then the envelope would repeat after 99×67 packets or seconds (if time slice is used), because at that interval, a whole number of each of the waves are present.
[0073] The AE function 12 , performs the tasks of, given or initialized with a lottery number, creates the ambiguity envelope as described above, and when is inputted a packet sequence number or time sequence, looks up the corresponding offset for it. The amplitude or offset of the ambiguity envelope may be positive, zero or negative for different packet sequence numbers. It may be a whole number that may be rounded from a fraction or may be fraction.
[0074] At sub-step 2 , the standard 128-bit encryption key and the offset from the ambiguity envelope function 12 is input to the Jitter function 14 . The Jitter function 14 then yields a random-variant-key 18 for a given packet sequence number, as illustrated in Step 86 . At sub-step 3 , a standard encryption function 42 is used with the random-variant-key 18 . At sub-step 4 , a function keeps track of the incoming and outgoing packet sequence numbers by incrementing these two variables. These variables are used in sub-step 1 and sub-step 3 as shown.
[0075] The Step 84 functions of AE function 12 and Jitter function 14 , as outlined above, are duplicated in the software or firmware at both the ends of the wireless transmission. The separate incoming and outgoing packet sequence numbers synchronize the generation and use of the random-variant-keys 18 at both ends of transmission.
[0076] Generally for each transmission/communication, the packet sequence number is initialized. However, there may be reset or synch commands exchanged between the two ends of transmission that would reset or re-synch the packet counters to either zero or another fixed number. Alternatively, instead of packet number a time such as in seconds referenced to the beginning of the session may be used. When time is used the ambiguity envelope on the x-axis will have time in seconds. A particular offset for a given time read on the x-axis may be used until the next time segment.
[0077] Step 86
[0078] The offset 2 is used to jitter or vary the prior art key 20 . For example, if the AE offset is 69, this number may be used arbitrarily so that the random-variant-key for this packet may be where the 6 th , 9 th , 15 th and 69th bit are flipped in the 128 bit encryption key.
[0079] If offset is zero, the packet data may be dummied up. If offset is negative, then a slightly different jitter approach may be used or the negative may be treated as a positive offset. If the offset is a whole number and a fraction such as 79.23, then these numbers may be used to decide which of the bits will be altered or flipped.
[0080] The random-variant-keys, as described above, have no mathematical relationship to the original static key 20 . Thus the jitter function 14 creates a large number of random-variant-keys 18 from one original key 20 that permit a different random-variant-key to be used for each packet as long as the incoming and outgoing packet sequence numbers remain synchronized at the two ends of the wireless transmission path.
[0081] In an alternative scheme different layers of random-variant-keys may be used. For example, what is described above with reference to FIG. 3B-1 may become the first layer of random-variant-keys and what is described in Step 87 , in FIG. 3B-2 may become the second layer of random-variant-key.
[0082] Step 87
[0083] FIG. 3B-2 illustrates that the offset number itself may be used to create another key, where the offset number is placed in some random variable location of the 128 bit key. As an illustration, if the offset is 329.72, the second layer of random variant key may be the number 329 starting in the 72 nd bit location. Similar other schemes may be used based on the offset.
[0084] Now with the help of FIGS. 4 to 7 , different applications where the security function 10 of FIGS. 1 and 2 may be used are described. FIG. 4 describes a wireless network application, FIG. 5 describes a cell phone application, FIG. 6 describes a mobile ad hoc wireless network application, and FIG. 7 describes the use of optical means for distribution of BRNs in some of the applications.
[0085] Wireless Network Application 100
[0086] With reference to FIG. 4A , this invention describes a system of security 100 in a nationwide wireless network that uses the security function 10 of this invention.
[0087] The system 100 may use adapted wireless access points (WAPs) 140 connected to either a local area network, a wide area network of a business or to a global network 112 . The WAPs may be used by wireless devices such as laptops 132 , of users with cell phones 130 . The users may be employees of a business, or at large users who have subscribed to this service as described herein.
[0088] In the system 100 , there is a call screening function 102 that receives cellular calls with caller id and geographic cell data and screens permitted calls based on a pre-stored list of caller id; a call mapping function 104 that maps the call to a WAP in the area identified by the cell; and a call routing function 106 that routes the call to a telephone number assigned to a WAP in the area.
[0089] The service related to functions 102 , 104 , and 106 maybe provided by a service provider or the service maybe provided by a cellular telephone company 120 , which provides the telephone numbers. It is to be noted that the cell network provides a unique caller id mechanism that is tied to the SIM card of the cell phone, along with a cell based geographic location identification of the caller's physical location at the time the call was made.
[0090] Some of these functions, 102 , 104 and 106 may be provided by a cellular company and other functions provided by a service provider. For example, the cellular company may provide caller id and geographic location data for each call and the cellular company 120 may maintain a list of authorized account holder caller ids, who have subscribed to this service and screen calls against this list and forward such screened calls to a service provider. The service provider may a business entity that maintains the servers that facilitate the automatic operation of functions 102 , 104 and 106 .
[0091] The service provider then may map the caller id and location data to a WAP in that geographic area. The mapping may be based on both the geographic area as well as the caller id. This dual mapping would enable identifying and mapping the callers to those WAPs that are available for certain network as those belonging to a national business based on caller id identification. This would enable different WAP and networks to be maintained for different national companies. The service provider then is able to route the calls from cell phones to a specific WAP in the geographic area.
[0092] In this system of security 100 , the prior art WAP 108 is adapted with a telephone interface and a simplified IVR 110 that is able to voice deliver a sequence of numbers resembling a lottery ticket, such as two digit BRNs, to the caller.
[0093] The WAP 108 is further adapted with the functions of security function 10 , as was described earlier with reference to FIG. 1 . These functions are bounded random number generator function 16 , ambiguity envelope function 12 , and jitter function 14 . These functions (i) generate BRNs, (ii) converts the BRNs numbers to an envelope, with x-axis packet and y-axis identifying envelope amplitude as an offset, and (iii) using the offset as a parameter provide random variants of the pre-placed encryption key and using the random-variant-key as the encryption key in place of the pre-placed key for encryption in the WAP.
[0094] The adaptation of WAP 108 also includes a function to receive a call, create a data record anchored by the caller id of the call, and select a port number that may be assigned to this caller, use function 16 to generate BRNs 17 . The adapted WAP 140 maintains data records with the information fields of, time stamp of the call, caller id of the call, port number assigned to this call and the BRNs that were generated for this call. Similar records are maintained for each call that is received by the adapted WAP 140 . The WAP 140 may also have a feature to delete such a record at the end of session or 24 hours which ever occurs first
[0095] The wireless card 134 present in the laptop computer 132 of the user is an adapted wireless network interface card. The wireless interface card 134 adapted with a function to display and be able to input a series of random numbers and a port number of a WAP via a display screen 122 .
[0096] The wireless card is further adapted with some of the function of security function 10 that is the ambiguity envelope function 12 and jitter function 14 . These functions (i) converts the BRNs numbers that are received via screen 122 , to an envelope, with x-ax-packet and y-axis identifying envelope amplitude as an offset, and (ii) a function that using the offset as a parameter provide randomly variants of the pre-placed encryption key and using the random-variant-key in place of the pre-placed key for encryption in the wireless card 134 . The wireless interface card 134 of the computer device 132 is adapted to work with the adapted Wireless access point 140 .
[0097] Hence, the adapted WAP 140 and the adapted wireless card 134 are able to use random-variant-keys for encryption and decryption of the wireless communication between the wireless card 134 and the WAP 140 .
[0098] FIG. 4B illustrates the operation of the nationwide wireless application of this invention.
[0099] At Step 1 , the laptop computer user equipped with an adapted wireless card, using his cell phone, calls a designated telephone number.
[0100] At Step 2 , the cell phone company 120 receives the call.
[0101] At Step 2 A, the service provider performs a Screen Function, which screens the call as one who has subscribed to the service, based on caller id and then routes the call to a Map function.
[0102] At Step 2 B, the Map function maps the call's geographic cell location to available WAPs in that cell location. The mapping in addition to the physically proximity of the WAP to the cell location may also use the caller id for mapping. The caller id mapping may be able to differentiate those WAPs that belong to a private business network belonging to a national business and are allowed to be used by pre-identified callers with pre-registered caller ids with this business.
[0103] If the mapping function is unable to map such a refinement of location, due to multiple WAPs in the same location, the caller may be asked to select from a sorted list of locations in the specific cell by the Map functions.
[0104] At Step 3 , the cellular company uses a Route function, which routes the call via a public telephone network 121 to the specific WAP approved for the caller's use from the collection of WAPs in the database.
[0105] At Step 4 , thus the call, after being routed through the Screen Function, the Map function and the Route Function, is answered by the specific WAP adapted with a telephone modem interface with an IVR. The caller is unaware of these functions and the call is answered by the specific WAP close to the caller's physical location.
[0106] At Step 5 , the adapted WAP 140 answers the call.
[0107] At Step 5 A, the WAP 140 creates a record with the time stamp and caller id, assigns a port number, generates and stores in the record the BRNs, and voice delivers BRNs to the caller along with the port number.
[0108] At Step 5 B, the WAP 140 monitors the sessions and deletes the record, if the wireless communication session is not established within a specified time threshold of the time of delivering the BRNs to the caller and deletes the record at the end of the session or up to a time limit such as 24 hours if the session is continuing. Thus the WAP does not maintain a long list of records anchored by the caller id and the port number and frees up the port for other users.
[0109] At Step 6 A, the caller hears the seven numbers port number and the six BRNs and at step 6 B enters them into the screen 122 that is provided by the adapted wireless card. The caller enters his caller id and clicks OK to complete Step 6 B.
[0110] In this application, the caller id of the phone that is used to call the WAP or some other number that is created by the caller may be used for authentication between the laptop and the wireless access point. If the caller id is used it is automatically recorded from the call by the WAP, and is also entered by the user along with lottery numbers in screen 122 as shown in FIG. 4B . This number may be used in the body of the data packets to authenticate the laptop to the WAP and vice versa.
[0111] At step 7 A, the adapted wireless card stores the BRNs and uses security function 10 to create random-variant-keys that are used in place of the standard key for encryption and decryption of the wireless communication. At Step 7 B, a similar function is performed in the wireless access point 140 .
[0112] At Step 8 , the packets that are exchanged between the laptop and the WAP may provide the port number in the header of the packet in addition to the prior art information such as SSID. This enables the WAP to identify the packets for one of the ports and be able to find the record that has the caller id and the BRNs and know which BRNs to use for this particular laptop transmission for this particular user. This enables the WAP to apply the right envelope and the right random-variant-keys to decrypt the packet and find in the data the caller id, which is used to authenticate the laptop user as the one who made the call and was given this set of BRNs.
[0113] Cell Phone Network Security System Application 200
[0114] Cell phones and similar wireless devices are used by individuals, law enforcement groups, business entities, and other special groups who may wish to add extra security to their conversations and data transmittals than what is provided by the digital phones themselves as part of wireless security by the cellular telephone companies. Such wireless devices are used for both voice and data communication.
[0115] As part of the encryption already provided in digital cell phones, an encryption key that may be part of the SIM of a cell phone encrypts the wireless communication from the cell phone to the cell company network, where the cell company decrypts the communication and may route it on a land line to the network of the recipient cell phone company, where the recipient phone company encrypts it with the encryption key of the recipient phone and routes it wirelessly to the recipient phone. Thus this encryption security as provided by prior art devices protects the wireless part of the communication. Many people are of the opinion that this encryption is not strong and may be broken by determined parties. The security provided by the security function 10 as described earlier with reference to FIG. 1 may additionally be provided to such a wireless or cellular network. The security function 10 may be adapted in the cell phones to work at a layer below the mode of encryption security in prior art cell phones, thus leaving the prior art encryption intact.
[0116] With reference to FIG. 5 , a system of security 200 against eavesdropping between handheld wireless devices such as cell phone communication based on security function 10 is described. The system 200 has prior art cell towers 220 , prior art cell phones 202 , and prior art caller id 204 associated with each phone.
[0117] In system 200 , each cell phone 202 is adapted to provide the security function 10 as has been described earlier with reference to FIG. 1 . In this adaptation, each cell phone is further adapted with an AE cell Phone Function 206 , BRN Function key 208 and AE function key 210 .
[0118] The AE cell phone function 206 provides interfaces to soft key 208 and soft key 210 and maintains a table 212 . The table 212 maintains a list of phones identified by caller id 204 and their corresponding BRNs 17 .
[0119] When the BRN function key 208 is activated, it launches the BRN function 16 of the security function 10 and displays BRNs 17 on the screen of the phone 202 . These BRNs 17 are then manually transferred or copied to other cell phones. The BRNs may also be transferred via an optical interface, if the phones 202 are equipped with such an interface.
[0120] The function 206 maintains a table 212 , which for each caller id 204 maintains the corresponding BRN 17 . Thus function 206 allows each phone to maintain a BRN for itself and each phone it may choose to communicate with the use of security function 10 .
[0121] Soft key 210 enables each phone 202 to choose to activate the security function 10 for all calls or for some calls by turning the soft key on and off. When the soft key 210 is off, the phone works like a prior art phone without using the security function 10 . hence, in this system 200 , each phone may selectively enable and disable the security function 10 for each communication by setting a flag via soft key 210 that is under the control of the user.
[0122] In FIG. 5 , for the purpose of explanation, one of the cell phones 202 is identified as cell phone A 202 A and another is identified as cell phone B 202 B.
[0123] When cell phone A communicates with the cell phone B, and when the soft key 210 is activated in the cell phone A, the cell phone A activates the function 206 . The AE cell phone function 206 searches for the BRNs in the table 212 , that are applicable to the caller id 310 332 4343 of cell phone A (caller phone), as 345679 and searches for the BRNs in the same table 212 , that are applicable to the caller id 626 332 4834 of cell phone B (called phone). The function 206 with the help of function 10 uses these BRNs to generate random-variant-keys and uses random-variant-keys for encrypting outgoing transmission that are from the BRN associated with own caller id and uses the random-variant keys for decryption that are from the BRN that is associated with the caller id of the other phone in the table 212 . A similar operation takes place in the called cell phone B.
[0124] Cell phone A and B each equipped with a security function 10 that generates BRNs for each phone or caller id, converts each BRNs at each end into an ambiguity envelope, with an x-axis and a y-axis and with a jitter function 14 that using the offset from the envelope creates a time and packet dependent sequence of random-variant-keys from the existing key and use such keys for encryption.
[0125] Hence in this application, it is possible, while leaving all the functions of existing cell phone intact, add or overlay AE encryption security between any two or more specific cell phones. Each cell phone pair may have software functions that enable a layer of encryption using AE in addition to what ever is used in prior art. Hence, the AE can be optionally be used between any two phones and not other phones and not all phones and it may be activated or deactivated to be used or not used for each call. When the call is received at a cell phone and if AE is on, then it checks the caller id against the list and if a BRN is found, which will be the same as used by the caller, then AE encryption is used.
[0126] The system of security 200 has an exchange mechanism where the cell phones may use manual, infrared, and radio frequency means of exchanging the BRNs. AE may also be used in many other wireless as well as wired applications that are not described here.
[0127] Mobile Ad Hoc Wireless Networks 400
[0128] Some times ad hoc wireless networks may need to be set up in remote areas and or in a theatre of operation. FIG. 6 shows the mobile ad hoc wireless network application 400 most likely to be used in a theatre of operation. Assuming such an application 400 has a base station 402 and multiple forward base stations such as 404 and 406 , and each base station supports multiple hand held units 406 and 408 .
[0129] These base stations 402 , forward stations 404 and 406 and handhelds 406 and 408 may be equipped with the security function 10 as has been described earlier with reference to FIG. 1 .
[0130] In such an application 400 , BRNs may be generated in the forward base station 404 and either may be manually keyed in each of the hand sets 406 for this forward base station. Alternatively, as shown in FIG. 7 , if the forward base station and the hand held units are equipped with infrared capability, then the BRN may be transferred to all hand units at one time within a few seconds from the forward base station by placing them in close proximity to each other.
[0131] As shown in FIG. 7 , the base station # 2 406 is equipped with an optical transmitting means 410 and each of the handhelds 408 are equipped with an optical receiving means 412 . Multiple handhelds 408 may be placed as a group in the optical transmitting path of optical interface 410 and thus would be able to simultaneously transfer the BRNs to the handhelds 408 . The BRNs may be changed for each mission or whenever desired for security reasons of the environment where the mobile ad hoc wireless network is put in place.
[0132] Hence, optical means such as use of infrared, if the devices are equipped with infrared sensors such as commonly used in televisions and like, may be used to quickly and efficiently transfer the BRNs to the other end of the transmission path.
[0133] Different BRNs may be used for different forward base stations. For example forward base station # 1 404 may use BRN 1 that it generated for its hand held units 406 . Forward base station # 2 406 may use BRN 2 that is generated for its hand units 408 .
[0134] Forward base station # 1 to communicate with forward base station # 2 may generate BRN 3 and that may be manually entered in forward base station # 2 or copied via other means. Each of the forward base stations may use a different BRN such as BRN 4 and BRN 5 when communicating with the base station 402 . These BRNs 4 and 5 may be generated by base station 402 and manually communicated and entered in by the people setting up the base units at the time of set up. This having different BRNs spread out over a theatre of operation of ad hoc mobile network provides additional transmission security.
Other Applications
[0135] There are many other applications where the security function 10 may be used in addition to the three applications of wireless networks, cell phone networks and ad hoc wireless networks as described above.
[0136] In an application, the wireless and wired part of a network may be combined to provide the security function 10 over an entire network from end to end. In this application the user of a laptop may directly contact the host computer and receive BRNs. While the user may still use a wireless network, the security function 10 may provide security over the entire network from the laptop to the host computer including the wireless and the wired part of the network to the host computer.
[0137] The system of security 10 may also be used in the wireless device that may be Bluetooth equipped device, where the communication is between the cell phone and a Bluetooth extension of the device such as an earpiece.
[0138] If the other end of the Bluetooth device is an earpiece, which may use prior art means of switches and display window to manually transfer the BRN. The cell phone owner reads the BRNs on the phone and one by one manually transfers them to the earpiece via the switches and the display. This manual operation is required to be done only once by the user or when ever he/she wants to reset the encryption, every few months or year or so. Alternatively, if the Bluetooth devices are so equipped, the BRNs may be transferred via Bluetooth format or an optical format.
[0139] Another application may be satellite to ground communication, where the BRNs may be long and complex and are installed in the satellite at launch times or they may be updated at other times by other means.
[0140] The security function 10 may be implemented in software, firmware and hardware integrated circuits depending upon the application. If implemented in an integrated circuit chip that embeds the security function 10 then it has, (i) an interface for inputting a series of bounded random numbers, (ii) a logic that converts the numbers to an envelope, with x-axis corresponding to a packet sequence and y-axis corresponding to an envelope amplitude offset for a packet sequence, and (c) a logic that uses the offset for a packet sequence number and a static encryption key as inputs and randomly variates the static encryption key outputting random-variant-keys, thereby enabling the use of the random-variant-keys for encryption and decryption of data packets in place of the static key.
[0141] The use of security function 10 in these and other applications provides for a robust and in-depth transmission security, where the security of the communication is not dependent upon the security of prior art encryption keys and thus reduces the cost and effort of frequently updating the prior art encryption keys and maintaining a key management infrastructure for them.
[0142] While the particular system and method as illustrated herein and disclosed in detail is fully capable of obtaining the objective and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.
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Systems and methods for security in a nationwide wireless network with geographically dispersed wireless routers are described. The wireless routers have an interface function with an ability to receive telephone calls from an authorized caller. The router, in response and on demand generates a set of bounded random numbers (BRN) as a random seed for use in generation of encryption keys for communication security between the router and a portable wireless device of the caller.
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This is a continuation of application Ser. No. 07/314,326, filed 02/22/89, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improved trench formation in semiconductor devices and, more specifically, to minimization of stress on trench wall insulation.
2. Brief Description of the Prior Art
It is well known in the semiconductor art to isolate adjacent active or moat regions from each other by means of a trench. A trench is a groove in a semiconductor substrate which has an insulating sidewall, generally formed from a layer of silicon oxide and a layer of silicon nitride, and is generally refilled with polysilicon up to the level of the substrate surface. Conventional polysilicon refilled trench isolation for bipolar or CMOS circuits has several problems in the areas of defect generation and void formation. Void formation and/or peculiar topography occurs when both the interior and exterior of the trench surfaces are oxidized. Detailed discussions of the problem appear in IEDM '84 conferences which are published at IEDM Technical Digest, pages 586, 1984. Defect generation is particularly noticeable during oxidation of the surface of the device with a polysilicon filled trench wherein both the substrate and the polysilicon form oxides and expand against the, trench wall insulating layer, thereby placing a stress on the insulating side walls of the trench as well as on the junction of the oxides formed in conjuction with the polysilicon and substrate.
A solution to the above noted problem to eliminate the defect generation has been reported wherein oxide/nitride dielectrics are used in the trench before the polysilicon is deposited. The structure is known as Sealed Sidewall Trench (SST) isolation and is disclosed in U.S. Pat. No. 4,631,803. However, SST is complex. Besides, notches or grooves may still exist at the junction between the field oxide which is grown over the polysilicon in the trench and the field oxide which is grown over the single crystal silicon outside the trench.
SUMMARY OF THE INVENTION
In accordance with the present invention, the above noted problems of the prior art are minimized by removing the source of the stress between the polysilicon in the trench and the silicon substrate.
Briefly, in accordance with the present invention, the top portion of the insulator wall of the trench, in the regions where the field oxide would later be formed, as well as a portion of the oxide formed over the substrate, are removed and replaced by polysilicon. This is accomplished by forming layers of silicon oxide, silicon nitride and photoresist, in that order, over the substrate, patterning the photoresist and etching a trench. The walls of the trench are then oxidized and the trench is filled up to the level of the substrate surface with polysilicon, as in the prior art. The oxide is then removed along the sidewalls of the trench for a distance down from the trench top equal or greater than the distance from the top of the trench which will later become field oxide. Also, a portion of the oxide beneath the nitride is removed to essentially provide some undercut of the nitride. The region from which the oxide was removed is now filled with a second deposition of polysilicon with the second layer of polysilicon extending over the trench polysilicon and the nitride. The second polysilicon deposition is then etched back to remove substantially all of the second polysilicon deposition except for the former region of undercut under the nitride layer. The nitride layer is then removed, leaving the polysilicon-filled trench with oxide walls partway thereabout and with polysilicon extending over and above the oxide sidewalls to the level of the substrate surface. Also, the polysilicon in the former region of undercut extends from the trench over the substrate. The end result is that a layer of silicon now extends over the entire trench, its sidewalls and the region over the substrate where field oxide is to be formed. Accordingly, with appropriate masking and field oxide growth, the field oxide is formed over a continuous layer of silicon, thereby minimizing and possibly eliminating the problems inherent in the prior art as above noted.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a through 1g represent various steps in the process of forming a semiconductor device in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the Figures, there is shown in FIG. 1a a substrate 1 of silicon on which a layer of pad oxide 3 of thickness 100 to 500 or more angstroms preferably 350 angstroms is deposited. A layer of silicon nitride 5 of thickness 500 to 3000 angstroms and preferably 2000 angstroms is deposited thereover by low pressure chemical vapor deposition and a layer of photoresist 7 is spun thereover and patterned. Etching then takes place through the patterned photoresist to remove the exposed nitride 5 and oxide 3 as shown in FIG. 1a. Etching of the exposed silicon then takes place to provide a trench 9 in the substrate having a depth of about 4 to 8 and preferably 6 microns. After clean up of the trench walls, an oxide 11 of thickness 1000 to 3000 angstroms and preferably 2000 angstroms is thermally grown on the trench sidewalls to provide the arrangement as shown in FIG. 1b.
The trench 9 is then filled with polysilicon 13 up to the level of the substrate 1 by low pressure chemical vapor deposition by depositing polysilicon in the trench and over the nitride layer 5 with subsequent etch back. The nitride layer acts as an etch stop in the region adjacent the trench. The resulting structure to this point is shown in FIG. 1c.
The structure of FIG. 1c is then wet etched to remove exposed oxide, this etch step removing from about 2000 to about 4000 and preferably 3000 angstroms of the oxide 11 of the walls of the trench down to the level marked 17 in FIG. 1d. The etching depth on the oxide 11 is determined by the depth of the field oxide which will later be formed such that the remaining oxide 11 on the walls of the trench will be below the region of field oxide formation. The oxide etch also removes some of the oxide in the layer 3 beneath the nitride layer 5 to provide some undercut of the nitride layer. Polysilicon 15 is then deposited by low pressure chemical vapor deposition to a height of about one half the thickness of the sidewall 11 or about 500 to about 1500 angstroms and preferably 1000 angstroms, the polysilicon layer 15 filling the region of undercut of the nitride layer as well as the region of the trench side wall from which oxide was removed. The polysilicon layer 15 also covers the polysilicon 13 in the trench 9 and and the nitride layer 5. The resulting structure at this step of the process is shown in FIG. 1d.
The polysilicon is then etched back isotropically until all of the polysilicon has been removed from over the nitride layer 5 which again acts as an etch stop. The nitride layer 5 is then removed. The removal of the remaining oxide layer 3 depends upon subsequent processing steps in the formation of the final semiconductor device. It will here be assumed that the oxide layer 3 is also removed after removal of the nitride layer 5. The resulting structure is shown in FIG. 1e wherein the polysilicon deposited in the former region of undercut of the nitride layer remains and extends over the substrate 1.
The pad oxide 19 of about 100 to 500 and preferably 250 angstroms is then grown on the surface of the subtrate and a mask in the form of a nitride layer 21 of about 1000 to about 2000 and preferably 1500 angstrom is then formed by low pressure chemical vapor deposition and patterned over the oxide layer 19 by etching of the nitride to expose the regions over which the field oxide is to be formed. This arrangement is shown in FIG. 1f.
The surface of the structure of FIG. 1f is then cleaned and a field oxide 23 of about 8000 angstroms is then grown in the regions of exposed pad oxide to provide the structure as shown in FIG. 1g. Standard processing techniques for producing semiconductor devices are now employed to produce the desired circuit, as is well known in the art.
Since the silicon is continuous across the the trench, no stress is included which can generate dislocations. There will be no stress induced defects which usually have been observed in conventional trench isolation technologies as field oxides of greater than about 3000 angstroms thickness were grown. Also, the topography of the device is smooth with no voids or grooves. In addition, the thermal oxide without a nitride layer can be used on the trench walls, contrary to the requirements of the prior art. Sidewall leakage is reduced. As a result, the spacing between moat or active region area and trench edge can be reduced. Furthermore, the processing steps are compatible with CMOS and bipolar processing techniques and permit the use of other local oxidation processes, such as PBL and MF 3 R. The process steps as noted hereinabove are rlatively simple and permit a great deal of process latitude.
Though the invention has been described with respect to a specific preferred embodiment thereof, many variations and modifications will immediately become apparent to those skilled in the art. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.
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The disclosure relates to the article and a method of forming a field oxide which extends over an isolation trench and the adjacent substrate wherein a portion of the trench insulating sidewall at the top region thereof is removed and replaced by polysilicon. The exposed silicon on the substrate and adjacent polysilicon are than oxidized to form the field oxide which is continuous, disposed above and contacts the remaining sidewall insulator in the trench.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a process and an apparatus to form a continuous fin helically around the exterior of a cylindrical tube.
2. Prior Art
The process and the apparatus to manufacture helically wound fin tubing is well known in the art. Examples in the prior art of fin tubing include the patents to A. H. McElroy, U.S. Pat. Nos. 3,388,449; 3,500,903; and 3,613,206. The resulting fin tube is utilized in heat transfer applications where a fluid or gas may be passed within and through the tube. Heat transfer is accomplished by transfer of heat through the fins. Fin tubing finds many applications from air conditioning units to refrigerators to many industrial applications.
It is known that if the fin is helically wound tightly around the tube, it will provide a good heat transfer surface without fastening, bonding or otherwise affixing the fin around the tube. It has been found, however, that in order to properly wind the fin to the tube, the first: few revolutions of the fin must be secure to the tube, otherwise, the remaining length of tubing will not be properly affixed thereto.
Existing solutions to this problem include stapling the first fin or few fins at the initial end of the tube or manually curling these initial fins tighter. Optionally, the last few fins at the end of the tube may also be pulled down or stapled to assure a tight fit.
These procedures require additional time and expense to secure the fin at the end of the tube and require additional human intervention and personnel to secure the first few revolutions of the fin to the tube.
Accordingly, there is a need to secure the initial revolutions of the fin to the tube without manually tightening the fins to the tube.
It has also been found that it is advisable to orient the primary forming roller and the spindle roller such that the tip of the fin is thinned in relation to the base of the fin. This promotes the curling of the fin around the tube during the metal forming process. At the same time, if the fin is curled too tightly, the end of the fin will buckle and wave.
Accordingly, there is a need to prevent buckling and waving of the end of the fin tube by controlling tightness of the fin to the tube.
SUMMARY OF THE INVENTION
The present invention provides a process and an apparatus to form a continuous fin helically around the exterior of a cylindrical tube. The cylindrical tube, of copper or other malleable material, may be unwound from a spool or coil and thereafter straightened and stretched into a cylindrical tube. The tube may be cut to desired lengths and then positioned to begin the finning process. The tube is positioned with its downstream end projecting through a tube guide or bridge adjacent to the metal forming mechanism.
While the bare tube is proceeding through the foregoing procedure or thereafter, flat fin stock is both advanced and formed into an L-shape. The fin stock is advanced by a pair of driving gears, driven by a continuous belt. The continuous belt may be driven by a shaft extending from a pulley which is engaged with a motor shaft of a fin stepper motor by a drive belt. The action of the stepper motor will, thus, advance the fin stock strip up and into a gap or space created between a primary forming roller and a spindle roller. A pair of driving rollers serve to form the fin stock from a flat orientation to a 90° angle having a foot and a vertically extending leg.
The primary forming roller is normally in a default position slightly apart or moved away from the spindle roller to provide a gap therebetween. The primary forming roller, mounted on a frame, is attached to a primary forming roller shaft which is driven by motor "W". The frame is connected to an actuator which is normally in the retracted position. When the actuator extends, the primary forming roller moves and closes the gap between the primary forming roller and the spindle roller. When the fin has been inserted into the gap, the fin will be tightly wedged between the primary; forming roller and the spindle roller.
Each of four motors, "W", "X", "Y" and "Z", is thereafter initiated. The "Y" motor is connected to a conveyor which is, in turn, connected to the cylindrical tube so that movement of the conveyor moves the tube axially. The "X" motor is mounted on the conveyor and is attached to the tube. The "X" motor rotates the tube so that the tube spins about its axis.
The spindle has an extending shaft which extends through a spindle frame. The spindle shaft is rotated by the spindle motor or "Z" motor. Its motion is expressed in a number of revolutions.
Finally, the "W" motor rotates the primary forming roller.
While the "Y" motor axially advances the tubing stock, the "X" motor rotates the tubing stock. Simultaneously, the "W" motor of the primary forming roller and the "Z" motor of the spindle roller advance and form the fin into a curl which moves around the exterior of the tube.
In order to secure the fin to the tube, an initial number of revolutions of the fin will be curled tighter than the balance or majority of the fins on the tube. Thereafter, the fin will be wound at an average tightness around the tube defined as the normal or nominal speed. During the nominal speed, the peripheral speed of the spindle head to the peripheral speed of the primary forming roller is 1.1:1. During the initial finning operation, the peripheral speed of the "Z" axis is 1.2 times the speed of the "W" axis. Moving from the tighter curl to the normal curl, the speed of the "Z" motor may be reduced with respect to the "W" motor. Alternatively, the speed of the "W" motor may be increased with respect to the speed of the "Z" motor.
In the present arrangement, the relative speeds are all calculated and controlled in relation to the "Y" movement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart diagram illustrating the steps of the process to form a continuous fin helically around the exterior of a cylindrical tube;
FIG. 2 is a perspective view of a portion of the process and apparatus to form a continuous fin helically described in FIG. 1;
FIG. 3 is a sectional view taken along section lines 3--3 of FIG. 2;
FIG. 4 is a diagrammatic representation of a portion of the process and apparatus, as shown in FIG. 1;
FIG. 5 is a perspective view of a completed fin tube constructed in accordance with the present invention;
FIG. 6 is an enlarged view of the spindle head and primary forming roller utilized in the process and apparatus as set forth in FIG. 1; and
FIG. 7 is a block diagram illustrating the relationship of the various elements of the automated fin tube process and apparatus as set forth in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, FIG. 1 is a flow chart block diagram illustrating the steps and processes embodied in one particular embodiment of the present invention 10.
The cylindrical tubing used to form the fin tube may be copper or other malleable metal and may initially be wound on a large spool or coil (not shown). As shown at box 12, the tubing may be unwound from the spool or coil and, thereafter, pulled through a straightening roller or series of rollers. The tube is then clamped at each end and stretched to straighten it into a cylinder.
Finally, the tube may be cut to a desired length. In one arrangement, the tube is cut from 90" to 20 foot lengths.
During the next stage, the cylindrical tube is positioned to begin the finning process as illustrated at box 14. The bare tube, which has been cut and straightened, is then dropped or dumped onto a holding rack. A proximity sensor may be located at the base of the rack to sense the presence of a tube.
The bare tube is thereafter moved from the rack and loaded into a barrel by a capstan drive which moves the tube longitudinally. The barrel contains an input barrel rack which holds two tubes, one in the loading position and one in the finning position. The rack holds a tube in the loading position prior to the beginning of the finning operation. Once a tube is inserted, the input barrel is then rotated 180° from the loading position to the finning position.
It will be appreciated that by rotating the barrel, one tube can be loading while the other is in the finning process.
Thereafter, the input barrel moves axially so that the bare tube is positioned with its downstream end projecting through a tube guide or bridge which is adjacent to the metal forming mechanism to be discussed in detail. A collet or other similar device will engage then downstream end of the tube. A "Y" motor (to be discussed in detail herein) will then move the tube axially a short distance. This distance is referred to as the "strip back" which is used for connections, such as solder connections, when the fin tube is finally employed. Typically, the strip back may vary from 1/2 inch to six inches.
While the bare tube is proceeding through the foregoing procedure or thereafter, the fin stock is then both advanced and formed into an L-shape, as shown at box 16. This step is illustrated in FIGS. 2 and 3. The flat metal fin stock 17 may be supplied from a large roll (not shown in FIGS. 2 and 3) and then delivered through a series of free rollers 18 so that the fin stock moves in the direction of the arrows 20.
Thereafter, a pair of gears 21 will advance the fin stock 17. The gears are driven by a continuous belt 26 which rotates the rollers. The continuous belt may be driven by a shaft 27 extending from a pulley 28. The pulley 28 is engaged with a motor shaft 30 of a fin stepper motor 32 by a drive belt 34.
A pneumatic cylinder (not shown) is used to pinch together or separate the gears 21.
The action of the stepper motor 32 will, thus, advance the fin stock strip 17 up to and through a gap or space created between a primary forming roller 36 and a spindle roller 38 (shown by dashed lines in FIG. 2). The sole function of the fin stepper motor is to perform this function.
A bridge or tube guide 40 is adjacent to the spindle roller 38 and the primary forming roller (not shown).
During operation, as will be described herein, the primary forming roller is contiguous with the spindle roller and they work together to form the fin stock to the desired shape and helical configuration. The primary forming roller may be angularly oriented to the spindle roller.
The driving rollers 22 and 24 serve the function of forming rollers. The forming is done in two stages. As the fin stock 17 enters and passes through the first set of rollers 24, the fin stock is formed from and changed from flat stock to an approximately 45° angle.
By movement through and past the second set of rollers 22, the 45° angle is thereafter changed. A 90° angle is placed in the fin stock. Accordingly, the flat fin stock 17 is formed into an L-shaped fin 41 having a short foot and a vertically extending leg. When completed, the short foot will be against the exterior of the tube and the leg will extend vertically therefrom.
It will be appreciated that although the present embodiment utilizes an L-shaped fin, other fin designs may also be employed within the spirit of the invention.
The fin stepper motor 32 through its connection with the pulley 28, will drive the fin stock 17 up to the gap between the primary forming roller and the spindle roller. As will be described herein, the fin strip is pulled and extruded from the forming roller and spindle roller by movement of the rollers. The stock is not driven by the fin stepper motor 32.
Returning to a consideration of FIG. 2, the primary forming roller 36 is normally in a default position slightly apart or moved away from the spindle roller 38 to form a gap therebetween.
FIG. 4 is a simplified representation of the fin forming mechanism. The primary forming roller 36 is mounted on a frame 46. The primary forming roller 36 is attached to a primary forming roller shaft 48 which is driven by a motor 50. The motor will be referred to as the "W" motor to indicate the rotational movement of the primary forming roller 36.
The frame 46 is connected to an actuator 52. The actuator is normally in the retracted position. When the actuator 52 of the primary forming roller frame 46 extends, the primary forming roller 36 moves and closes the gap between the primary forming roller 36 and the spindle roller 38. When the fin 41 has been inserted in the gap between the primary forming roller 36 and the spindle roller 38, the fin will be tightly wedged therebetween. This step is illustrated in FIG. 1 at box 42.
The next step in the process is illustrated at box 44 wherein each of four motors to be described--W, X, Y and Z--is initiated. The four motors are illustrated diagrammatically in FIG. 4. The "Y" motor 54 is connected to a conveyor 56 which is, in turn, connected to the cylindrical tube 57 so that movement of the conveyor 56 moves the tube 57 longitudinally or axially. As will be described in detail herein, the "Y" motor and its movement (sometimes referred to as the "Y" axis) is the master reference or master axis and the other movements to be described herein are determined with reference thereto.
The "X" motor 58 is mounted on the conveyor 56 so that movement of the "Y" motor transports the "X" motor. The "X" motor is attached to the tube 57 and acts as the connection for the "Y" motor. The "X" motor serves to rotate the tube 57 so that the tube spins about its axis. This rotational tube drive will sometimes be referred to herein as the "X" movement or "X" axis. Its motion will be expressed in a number of revolutions.
The spindle 38 has an extending shaft 60 which extends through a spindle frame 62. The spindle shaft 60 is rotated by a spindle motor 64. The movement of the spindle motor 64 is referred to as the "Z" movement or "Z" axis. Its motion is expressed in a number of revolutions.
Finally, the "W" motor 50 rotates the primary forming roller 36. In the present .embodiment, each of these motors is a Servo motor which may be controlled and varied. Other types of motors are, of course, possible within the parameters of the invention.
While the "Y" motor axially advances the tubing stock 57, the "X" motor will rotate the tubing stock. Simultaneously, the "W" motor of the primary forming roller 36 and the "Z" motor of the spindle roller 38 advance and form the fin into a curl which moves around the exterior of the tube. These motions may be summarized as follows:
______________________________________SERVO MOTORS______________________________________Linear Tube Drive (Y-axis) Master Reference Axis - motion expressed in inchesRotational Tube Drive (X-axis) Slave Axis - motion expressed in number of revolutionsSpindle Drive (Z-axis) Slave Axis - motion expressed in member of revolutionsPan Drive (W-axis) Slave Axis - motion expressed in number of revolutions______________________________________
The relationship between the four drive motors and their rotations may be observed. For every inch that "Y" moves, "X" will move a number of revolutions which may be described in terms of fins-per-inch. This is the relationship of "X" to "Y".
There is also a relationship between the rotational tube drive and the primary forming roller drive "W". For every revolution "X" makes, "W" will make a number of revolutions This ratio expresses the relationship between the circumference of the tube and the circumference of the primary forming roll. In one example, for each revolution "X" makes, "W" makes 0.0597 revolutions. Since circumference equals π times the diameter, the ratio expresses the relationship between the diameters of the rotational tube drive "X" and the pan drive "W" as such: ##EQU1##
There is also a relationship between the primary forming roller drive "W" and the spindle drive "Z". For every revolution "W" makes, "Z" will make a number of revolutions. This relationship is called the primary forming roller to spindle ratio.
In one example, for every revolution "W" makes, "Z" will make approximately 17 revolutions during its normal or nominal speed. This relationship also may be defined as the relationship between the diameter of the primary forming roll and the diameter of the spindle roller: ##EQU2##
In order to secure the fin to the tube 57, an initial number of revolutions of the fin will be curled tighter than the balance or majority of the fins on the tube. A completed fin tube is illustrated in FIG. 5. After provision for the strip back, an initial number of fins are wrapped tightly around the tube, as illustrated by the distance shown by arrow 70. Thereafter, the fin will be wound at an average tightness around the tube as shown by the axial distance illustrated by arrow 72. This is the normal or nominal operating condition.
Optionally, the last number of fin revolutions may also be at a tighter than normal rate. This is illustrated by the distance shown in arrow 74. The movement of the motors during the distance 72 is referred to as the normal or nominal speed. The distances 70 and 74 are at a different speed and will wrap the fins tighter around the tube. The strip back on each end of the tube is also illustrated in FIG. 5.
The normal or nominal speed will be described first and may be illustrated by an example. In order to make a fin tube having a length of 100 inches, a one inch strip back at each end, and a pitch or number of fins of 10.5 fins-per-inch, the following will occur. Taking into account the strip backs, the linear tube drive or Y-motor 54 is commanded to move a total of 98 inches axially or lengthwise. The slave axes, X, Z and W, are commanded to follow Y. For each inch that Y moves the tube, X moves the tube 10.5 revolutions, resulting in a pitch of 10.5 fins-per-inch. For every inch Y moves, W will move 10.5 revolutions multiplied by 0.0597. As will be observed, the Y axis is the reference axis or reference speed with the other three movements corresponding to the movements of Y. During this operation, the four motors axially advance and rotate the tubing stock while simultaneously preforming the fin strip into an L-shape and forming and wrapping it tightly around the tubing.
It is known that the relationship between W, the primary forming roller drive, and Z, the spindle drive, plays an important part in the tightness of the curl of the fin. As an example, if the spindle head were operating at the same peripheral speed of the primary forming roller the ratio between them would be 1:1. During the normal finning operation, the ratio of the spindle to the primary forming roller is 1.1:1. This difference in their relative speed is known to encourage and produce curling of the fin as it exits the forming rollers. During the initial and final finning operation (as shown at arrows 70 and 74) the speed of the Z axis is approximately 1.2 times the speed of the W axis. This step in the process is shown at box 80.
After an initial number of fins are applied during the distance shown by arrow 70 in FIG. 5, the speed of the motors will be adjusted to the normal finning operation.
As shown at box 82, the speed of the Z axis will be adjusted to 1.1 times the speed of the W axis. This will result in the normally tight curl of the fin around the tube, which is less tight than the initial curl of the fin around the tube.
Moving from the tighter curl to the normal curl may be accomplished in a number of ways. The speed of the Z motor may be reduced with respect to the W motor. Alternatively, the speed of the W motor may be increased with respect to the speed of the Z motor.
In the present arrangement, the relative speeds are calculated and controlled in relation to Y movement. During the normal or nominal speed, the Y to W ratio is 0.537. In other words, for each inch of Y movement, W moves 0.537 revolutions. During the tighter, initial finning operation, W moves 0.510 revolutions. The W to Z ratio moves from 17 to 19. Finally, the Y to Z ratio moves from 9.129 to 9.67. As follows:
______________________________________Motor Normal Run Tight Run______________________________________Y to W 0.537 0.510W to Z 17 19Y to Z 9.129 9.69______________________________________
From the foregoing, it can be appreciated that a two-phase finning operation is quickly and simply accomplished.
Returning to a consideration of FIGS. 2, 3, and 4, the application of the fin to the tube is performed by the movement of the primary forming roller and the spindle roller. As described, during the metal forming operation, the fin stepper motor 32 is not operational. The movement of the primary forming roller and spindle roller pulls the fin stock 17 up to the forming area and wraps the fin around the tubing.
Returning to a consideration of FIG. 1, near the end of the desired length of tubing (prior to a total "Y" movement of 98 inches during the finning process), all four of the motors will be stopped, as shown at box 84. In other words, all four of the motors will be stopped after the Y motor has moved the tube axially a predetermined length. Thereafter, the fin stock will be sheared, shown at box 86.
Referring back to FIG. 2, a fin shear mechanism includes an extending blade 90, extending from an actuator 88. The fin stock is cut in front of or advance of the spindle roller and contiguous primary forming roller by movement of the actuator 88. Once the fin stock has been sheared, all four of the motors--W, X, Y and Z--are reactivated so that the finning operation continues for the length of the fin between the primary forming roller/spindle roller and the blade 90. This step is indicated at box 92 in FIG. 1. The finning operation will continue until the remainder of the fin is applied to the tube. Optionally, the final finning operation may be performed at the 1.2 to 1 ratio to produce a tighter curl at the end.
In one example, approximately six and one-half rotations of fin will be made around the tube to complete the operation. The primary forming roller and spindle roller will then be stopped just before the end of the fin strip leaves the forming roller/spindle roller.
The next step of the operation is indicated at box 94 wherein the actuator 52 is retracted. The actuator 52 on the primary forming roller or pan is retracted thereby withdrawing the primary forming roller away from the spindle roller and providing the gap therebetween. The actuator 52 retains the primary forming roller 36 away from the spindle in the default position until a new sequence begins.
After the gap is opened, the Y axis and X axis continue for a short period in order to eject the tube.
Finally, a number of additional optional steps may be performed. As shown at box 96, the finished fin tube is ejected. The Y motor 54 moves the finished fin tube axially to a dumping position. The collet, not shown, holds the tube to the X motor, and releases the tube. The tube is then separated from the collet and moved by a conveyor to be swaged as shown at box 97.
Finally, optional procedures may be performed such as a pressure test shown at box 98. Air under pressure is injected into the tube and a sensor is used to detect any leaks in the tube.
An additional feature has been combined with the present invention. It has been observed that at the initial stage and optionally, at the end, where the fin tube is curled tightly to the tube, the ends of the fin tend to wave or buckle. In other words, the tighter the fin is wrapped around the tube, the more waving or buckling of the fin is promoted. This problem is exacerbated because the fin gets thinner at its end than at its base. A solution to this problem has been found by redesigning the standard cylindrical spindle roller.
FIG. 6 is an enlarged view of the spindle head 38 along with a cross-section of the primary forming roller 36. The fin 41 being formed is shown in cross-section therebetween. The fin has an L-shape with a shorter foot at the top and a tapered vertically extending leg 99.
The primary forming roller is angularly oriented to the axis of the spindle roller. The spindle roller has a first upper surface 100 which is substantially cylindrical. The first upper surface may also have a chamfered end 101 closest to the foot.
Adjacent to the upper surface of the spindle roller is a lower surface 102 which is gradually tapered in from the larger diameter to a reduced diameter. The lower surface portion of the spindle roller has a curved convex profile. The combination of the upper surface 100 and the lower surface 101 of the spindle roller acts to form a fin having a lower portion adjacent the foot and adjacent the tube, and an upper portion extending therefrom. Historically, the vertically extending leg of the fin has had essentially a straight taper from base to the tip. It has been found and demonstrated that altering the otherwise cylindrical shape of the spindle roller, forms a fin leg that is thicker at the base but does not overly thin at the end, causing waving or buckling.
In summary, the design of the spindle roller allows the fin to be wrapped at a desired tightness while avoiding waving or buckling at the end of the fin.
FIG. 7 is a block diagram showing the relationship of the motors, the forming rollers and the fin shear. Each element is monitored and controlled by the central processing unit 104. The X, Y, Z and W motors are each connected to the central processing unit. The speed of each motor is monitored and controlled several times per second. As an example, as the Y motor increases in speed, the remaining motor will increase in speed to maintain the proportional relationship.
The foregoing process may thereafter be repeated quickly and efficiently with a minimum of human assistance and intervention.
Whereas, the present invention has been described in relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention.
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A process to form a continuous fin helically around the exterior of a cylindrical tube by rotation of a primary forming roller and rotation of a contiguous spindle roller. The process includes advancing and inserting the fin in a gap between the primary forming roller and the spindle roller. The gap between the primary forming roller and the spindle roller is closed and the fin is tightly gripped therebetween. The tube is axially moved for a first, chosen length, while, at the same time, the tube is rotated at a first speed, the primary forming roller is rotated at a first speed and the spindle roller is rotated at a first speed. Thereafter, the tube is axially moved for a second, chosen length, while, at the same time, the tube is rotated at a second speed, the primary forming roller is rotated at a second speed, and the spindle roller is rotated at a second speed.
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