description
stringlengths 2.98k
3.35M
| abstract
stringlengths 94
10.6k
| cpc
int64 0
8
|
|---|---|---|
FIELD OF THE INVENTION
This invention relates to mining technology and a method for the processing of recovered bitumen bearing oil sands from the earth. More particularly, the invention relates to a mobile system of equipment for increasing the efficiency of the ore mining operation.
BACKGROUND OF THE INVENTION
The Northern Alberta Tar Sands are considered to be one of the world's largest remaining oil reserves. The tar sands are typically composed of about 70 to about 90 percent by weight mineral solids, including sand and clay, about 1 to about 10 percent by weight water, and a bitumen or oil film, that comprises from trace amounts up to as much as 21 percent by weight. Typically ores containing a lower percentage by weight of bitumen contain a higher percentage by weight of fine mineral solids (“fines”) such as clay and silt.
Unlike conventional oil deposits, the bitumen is extremely viscous and difficult to separate from the water and mineral mixture in which it is found. Generally speaking, the process of separating bitumen from the tar sands comprises six broad stages. 1) Initially, the oil sand is excavated from its location and passed through a crusher or comminutor to comminute the chunks of ore into smaller pieces. 2) The comminuted ore is then typically combined with hot process water to aid in liberating the oil. The combined tar sand and hot water is typically referred to as a “slurry”. Other agents, such as flotation aids may be added to the slurry. 3) The slurry is then passed through a “conditioning” phase in which the slurry is allowed to mix and dwell for a period to create froth in the mixture. The term “conditioning” generally refers to a state whereby the slurry is sufficiently mixed and aerated that a commercially viable amount of the bitumen has left the mineral component to form an oily film over the bubbles in the slurry. 4) Once the slurry has been conditioned, it is typically passed through a series of separators for removing the bitumen froth from the slurry. 5) After the slurry has been sufficiently processed to remove the maximum practical amount of bitumen, the remaining material, commonly known as the “tails”, is typically routed into a tailing pond for separation of the sand and fines from the water. Due to the time required to clarify the tailings water, the process requires the continual addition of fresh water. 6) The separated bitumen and water is then delivered to a secondary extraction process that further removes mineral and water content and provides a diluted bitumen product for delivery to an upgrader that converts the bitumen into a commercially usable product.
It has been recognized for a long time that, since the bitumen comprises a relatively small percentage by weight of the ore initially extracted, separation of the mineral content from the ore as soon as possible after excavation would lead to the most efficient and cost effective mining process. It has also been recognized that it would be useful to immediately recycle the process water used to create the slurry rather than the current requirement of continually using fresh water due to the slow process of clarifying tailings water. While these advantages have been known, to date there has been no commercially viable method of extracting the mineral content soon after excavation and recycling the process water. Generally, the sand and fines settle out of the tails at different rates with the fines taking a long time to settle out. This results in a tailings pond comprised of a sand deposit, a suspension of fines and water, and a thin layer of clarified water on the top of the tailings pond. While the thin layer of clarified water is clean enough that it may be siphoned off and recycled as process water, the bulk of the water remains trapped in the suspension. Furthermore, as settling progresses, the settled fines trap a significant percentage by weight of water. The net result has been extensive tailings ponds that require significant containment structures and associated ongoing maintenance as well as increasing transportation costs as the tails must be transported to new tailings deposition sites as existing ponds are filled. Handling the tails and transporting them to available tailings ponds has become a difficult and expensive logistical problem in mining the oil sands. Additionally, a large volume of water is tied up in existing ponds, necessitating a large ongoing demand for fresh process water.
Over the years, a variety of methods have been used to process and transport the sand from the excavation site. Initially, oil sand excavation and transport were completely mechanical via conveyor belts extending from the mine face to a large facility for processing the mined ore. As mining progressed the conveyors lengths were increased to transport ore from the receding mine face to a large processing facility. The use of conveyors led to many difficulties including high energy costs and mechanical breakdown which led to work stoppage. As mining continued, the use of conveyors to transport the ore over extended distances became unworkable.
Large ore trucks were instituted to replace the conveyor system for transporting ore from the mine face to the processing facility. The ore trucks, however, are expensive to purchase and operate and often create inefficiencies in the production process.
As described in Canadian Patent No. 2,029,795, it was determined that it was preferable to deliver the ore by truck from the mine face to an intermediate site where the ore would be crushed and combined with hot process water at a slurry preparation facility to create a pumpable slurry for transport through a pipe. This “hydro-transport” process served the dual purpose of efficiently transporting the slurry from an intermediate site relatively near the mine face to the large processing facility and allowing time for the slurry to be sufficiently conditioned on route. Provided the hydro-transport was over a sufficiently large enough distance that the dwell time in the pipe was sufficiently long, typically at least 1 kilometer, the slurry would arrive at the processing facility already conditioned and ready for separation. Thus, the previously required separate conditioning step could be omitted from the process.
While the hydro-transport solved some of the difficulties with transporting the ore from the mine site face to the separation facility, it did not solve the long term need to reduce the mechanical transport of large volumes of mined oilsand from the mine face to the intermediate site. As will be appreciated, continual excavation results in the active mine site face being located further and further from the crusher and slurry preparation facility. Solutions to date have typically relied on constructing longer conveyor belts to transport the ore, or use additional trucks, to move the ore from the mine face to the slurry facility at the intermediate site. Though these solutions provide temporary relief, they do not solve the inefficiency of transporting the mineral component further than required.
One concept was to do away with the transport step completely by locating all of the ore processing machinery near the mine face. An example of this concept is disclosed in Canadian Patent No. 2,092,121 and Canadian Patent No. 2,332,207. These references disclose a single mobile excavator and bitumen extraction facility, commonly referred to as a tar sand combine, that follows the mine face as digging progresses. This solution is not ideal as it requires the continuous transport of a large amount of extremely heavy machinery and water including a slurry preparation facility. In addition, connections to the hydro-transport pipeline and process water supply line must be continuously extended as the combine advances. Further, some embodiments suggest separating the mineral component at the mine face. Since the slurry must first be conditioned prior to separation, these embodiments require the continual transport of large volumes of slurry as it is conditioned.
In Canadian Patent Application No. 2,453,697, the idea of a process line comprising a combination of mobile and relocatable equipment units at the face of an oil sand mine site is suggested. The '697 application proposes a process comprising a mobile excavator that advances along a mine face, a mobile comminutor that advances behind the excavator to crush the mined ore to a conveyable size, and a relocatable conveyor that extends along the mine face for receiving the crushed oil sand and conveying it to a relocatable slurry facility for preparing slurry for hydro-transport. The slurry facility may be connected directly to a fixed pipe for hydro-transport. The process line of the '697 application allows for relatively small components, such as the excavator and comminutor, to be mobile and follow the mine face as digging progresses. Less transportable equipment such as the slurry facility and hydro-transport pipe, are relocatable. That is, they are stationed in a fixed location for an extended period of time (months), but may be relocated once the excavator has removed all of the ore within near proximity to the relocatable conveyor.
The disclosure of the '697 application suffers from several limitations. First, the dwell time of the slurry facility is determined solely by the rate of excavation and the length of the first relocatable conveyor. Thus, to increase the dwell time in a particular location, either the rate of excavation must be slowed or the length of the conveyor must be increased. The Northern Alberta region has extremely harsh weather conditions and it has been found that extensive conveyors consume a considerable amount of energy, and are prone to break down resulting in work stoppage. For this reason, the length of the conveyor is preferably not overly long. However, it is also desirable that the slurry facility be relocated as seldom as possible necessitating a minimum length of conveyor in order to access a suitable volume of ore to supply the slurry facility. An additional limitation of the '697 application is that a practical relocatable slurry facility or relocatable desanding facility is not disclosed.
A further problem faced by the industry is the extensive use of water to extract the bitumen from the ore. While the sand portion of the mineral component may be practically removed from the slurry, the fine tailings, clay and other fine-sized material, is difficult to remove from the tailings and tends to remain in suspension. The solution to date has been to store the tailings in ponds for a sufficient period to allow the fines to settle out of the water. It has been determined, however, that it takes an extremely long period of time for the fines to settle out, resulting in ever increasing tailings ponds. Additionally, water becomes trapped in the interstitial spacing between particles so that even after the fines have settled a large amount of water is trapped in the settled material. Other than the excessive water requirements, tailings ponds create an environmental and logistical challenge as tailings must be continually disposed of in the continuously growing volume of tailings ponds which must be contained and maintained for years. There thus exists a need for a method of processing oil sands that obviates the need for extensive tailings ponds and provides for the recycling of water from the tails soon after deposition at a deposition site.
A further limitation of the prior art is that there is no practical solution provided for handling tailings. Rather, current deposition methods result in a separation of a course tails and a fine tails, maintaining the need for extensive tailings ponds to provide settlement of the fine tailings component. There thus exists a need for a method of processing oil sands that produces a whole dry tails comprising both the sand component and the fine tailings.
There thus exists a need to increase the efficiency of excavation and transport processes to reduce operating costs. There exists an additional need to increase the operating period for an excavator servicing a transportable slurry facility, without increasing the distance of ore transport from the excavator to the facility. There exists a further need for a process capable of removing the mineral component of the oil sands at a proximate location to the mine face without the creation of extensive tailings ponds.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings which illustrate by way of example only a preferred embodiment of the invention,
FIG. 1 is an illustration of an embodiment of the process of the present invention.
FIG. 2 is a top view illustration of an embodiment of the process line of the present invention.
FIG. 3 is a top view illustration of an embodiment of the present invention.
FIG. 4 is a side view illustration of an embodiment of the present invention.
FIG. 5 is a side view illustration of an embodiment of the present invention.
FIG. 6 is a side view illustration of an embodiment of the present invention.
FIG. 7 is a side view illustration of an embodiment of the present invention.
FIG. 8 is a side view illustration of an embodiment of the present invention.
FIGS. 9 a - 9 c are top view illustrations of an embodiment of the present invention.
FIGS. 10 a - f are top view illustrations of an embodiment of the present invention.
FIG. 11 is a top view illustration of an embodiment of the present invention.
FIG. 12 is a process illustration of an embodiment of the present invention.
FIG. 13 is an isometric illustration of an embodiment of the present invention.
FIG. 14 is a side view illustration of an embodiment of the present invention.
FIG. 15 is a bottom view illustration of an embodiment of the present invention.
FIG. 16 is a side view illustration of an embodiment of the present invention.
FIG. 17 is a schematic view showing an embodiment of a modular, mobile extraction system according to an aspect of the present invention incorporating a plurality of mobile cyclone separation stages forming a mobile cyclone separation facility and a mobile froth concentrator vessel defining a mobile froth concentration facility.
FIGS. 18 a to 18 f are schematic plan views showing embodiments of the present invention.
FIGS. 19 a to 19 c are schematic plan views showing embodiments of the present invention.
FIGS. 20 a and 20 b are schematic plan views showing an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In one aspect the invention provides a process line for mining an oil sands ore body, the process line comprising an excavator for mining oil sands ore; a comminutor for receiving mined ore from the excavator, comminuting the mined ore to conveyable size and transferring the comminuted ore to a mobile conveyor for transporting the comminuted ore; the mobile conveyor having a free end, a discharge end and at least one drive for advancing the conveyor through an operational arc generally about the discharge end; whereby the excavator mines a section of ore within operational reach along the length of the mobile conveyor and supplies the mined ore to the comminutor, and the comminutor supplies conveyable ore to the mobile conveyor, and whereby the mobile conveyor is periodically moved about the discharge end to locate another portion of the ore body within operational reach of the mobile conveyor until substantially all of the ore body within the operational arc has been mined.
In a further aspect the invention provides a mobile conveyor for transferring mined oil sands ore from a mine face, the conveyor comprising: two or more conveyor sections; each of the two or more sections having at least one drive for advancing the conveyor, and at least one alignment device for detecting misalignment between at least one adjacent section and controlling the drive responsive to a detection of misalignment to align adjacent sections.
In a further aspect the invention provides a method of mining oil sands ore with a mobile conveyor, the method comprising:
at a first conveyor position:
excavating and sizing ore at a mine face within operational reach of the first position; transferring the sized ore to the conveyor; conveying the sized ore along the conveyor; and discharging the sized ore; after excavating, sizing and transferring substantially all the ore within operational reach of the conveyor in the first conveyor position, advancing the conveyor generally about the discharge end to a second conveyor position; and, excavating, sizing and transferring substantially all the ore within operational reach of the conveyor at the second position.
In a further aspect the invention provides a method of mining oil sand ore with a mobile conveyor, the method comprising: excavating, sizing and transferring to the conveyor all ore within operational reach along the length of the conveyor; conveying the sized ore along the conveyor to a discharge end of the conveyor; advancing the conveyor generally about the discharge end to locate the conveyor within operational reach of a further section of oil sand ore; excavating, sizing and transferring to the conveyor all ore in the further section within operational reach along the length of the conveyor; continuing to advance the conveyor about the discharge end to locate the conveyor within operational reach of additional sections of oil sand ore and after each advancement excavating, sizing and transferring the respective additional section of oil sand ore, until substantially all ore within an operational arc sector generally about the discharge end has been excavated, sized and transferred to the conveyor.
In a further aspect the invention provides a method of extracting a body of oil sand ore for conveyance to a mobile slurry facility, the method comprising: locating the mobile slurry facility near a mine face of a body of oil sand ore; positioning a mobile conveyor within operational reach of a section of the ore body and locating a discharge end of the mobile conveyor to convey mined ore to the mobile slurry facility; extracting the section of the ore body and conveying it to the mobile slurry facility; advancing the mobile conveyor generally about the discharge end to locate the mobile conveyor within operational reach of a further section of the ore body; extracting the further section of the ore body and conveying it to the mobile slurry facility; continuing to advance the conveyor and convey additional sections of the ore body to the mobile slurry facility until the ore within an arc sector about the discharge end of the conveyor has been extracted.
In a further aspect the invention provides a method of increasing the effective length of a mobile conveyor for conveying a mined ore, the method comprising:
(a) Locating a mobile conveyor within operational reach of a section of ore; (b) Extracting the section of ore within operational reach of the conveyor and transferring the extracted ore to the conveyor; (c) Advancing the conveyor generally about the discharge end to locate the conveyor within operational reach of a further section of ore; (d) Repeating steps (b) and (c) until substantially all ore within operational reach of the conveyor has been extracted. and, (e) relocating the discharge end of the conveyor to a substantial center of the arc.
In a further aspect the invention provides a method for increasing the mineable volume of ore capable of being transported from the mine site to a discharge point using a mobile conveyor, the method comprising: locating the mobile conveyor near a mine face with a discharge end located in communication with the discharge point; excavating a section of ore within operational reach of the mobile conveyor along the length of the conveyor; repeatedly advancing the mobile conveyor through an operational arc generally about the discharge end to locate and extract additional sections of ore within operational reach along the length of the conveyor; and, relocating the mobile conveyor to locate the discharge end in communication with a new discharge point located near the perimeter of the operational arc.
In a further aspect the invention provides a process line for excavating and processing oil sands ore near a mine face, the process line comprising: a mobile excavator for excavating ore along the length of a mobile mining conveyor; a mobile comminutor for receiving and comminuting excavated ore and transferring comminuted ore to the mobile mining conveyor; the mobile mining conveyor conveying the comminuted ore to a transfer conveyor; the transfer conveyor conveying the comminuted ore to a mobile slurry facility; the mobile slurry facility converting the comminuted ore into a slurry and pumping and conditioning the slurry through a hydro-transport pipeline to a mobile extraction facility; the mobile extraction facility receiving the slurry and combining with a water stream to separate a bitumen stream and a tailings stream from the slurry; herein the bitumen stream is directed to a separation facility and the tailings stream is directed to a tailings treatment facility.
In a further aspect the invention provides a process line for excavating and processing oil sands ore near a mine face, the process line comprising: a mobile excavator for excavating ore along the length of a mobile mining conveyor; a mobile comminutor for receiving and comminuting the excavated ore and transferring the comminuted ore to the mobile mining conveyor; the mobile mining conveyor conveying the comminuted ore to a transfer conveyor; the transfer conveyor conveying the comminuted ore to a mobile slurry facility; at the mobile slurry facility combining the comminuted ore with process water to produce a slurry and pumping and conditioning the slurry through a hydro-transport pipeline to a mobile extraction facility as a slurry feed; at the mobile extraction facility receiving the slurry feed and directing the slurry feed and a water stream as inputs to a three stage countercurrent cyclone separator; the cyclone separator producing a bitumen rich stream and a tailings stream; the bitumen rich stream being directed to a froth concentration unit; the froth concentration unit separating the bitumen rich stream into a bitumen product stream, a recycled water stream and a fine tailings stream; the fine tailings stream being combined with the tailings stream to produce a tailings product stream; the tailings product stream being directed to a tailings treatment facility; the tailings treatment facility receiving the tailings product and combining the tailings product with an additive to produce a treated tailings stream; the treated tailings stream being directed to a tailings pond; the treated tailings stream being separated into a dry tails phase and a water phase; and, the water phase being collected at the tailings pond and recycled as industrial process water.
FIG. 1 is an illustration of the process overview of the present invention. The aim of the present invention is to provide a closed loop mining process that minimises the transport of the mineral component of the ore from the mine face and treats the tails to release the water component for reclamation as industrial process water. The process may be described as comprising the following main stages:
excavating the ore 10 ;
conveying the excavated ore to a slurry facility 12
slurrying the comminuted ore 14 ;
hydro-transporting the slurry to condition the slurry and transport it to an extraction facility 16 ;
extracting from the slurry an enriched bitumen froth feed and a tailings feed 18 ;
treating the tailings feed with an additive 20 ;
depositing the treated tailings feed at a deposition site 22 ; and,
recycling the reclaimed water as industrial process water 24 .
FIG. 2 depicts the process line of the present invention comprising a mobile excavator 200 that excavates ore from a mine face 101 and transfers the excavated ore to a mobile comminutor 500 . The mobile comminutor 500 comminutes the ore to transportable size for delivery to a mobile mining conveyor 580 . The mobile mining conveyor 580 delivers the crushed ore to a mobile slurry facility 800 where the crushed ore is converted into a slurry with the addition of hot process water and further comminuting and screening. Optionally process agents or conditioning aids may be added to the slurry at the mobile slurry facility 800 . The slurry is pumped through a hydro-transport pipeline 850 to a mobile extraction facility 900 where the bitumen is separated from the mineral component. The separated bitumen is diverted to a secondary extraction facility 1500 while the mineral component is directed for tailings treatment 1100 prior to being deposited at a tailings deposition site 1150 . Tailings treatment 1100 preferably comprises the addition of an additive to the tailings to assist in separation of the water component of the tailings from the sand and fines. The treated tailings are then deposited at tailings deposition site 1150 . After separation of the water from the solid component of the tailings, the water may be collected at the tailings deposition site and recycled as industrial process water, either back into the process, for instance to be used in the slurry and extraction stages, or else directed for other industrial process water uses.
The stages of the process will now be described in more detail.
Referring to FIG. 3 , a top view of the excavation portion of the present invention is shown. A mobile excavator 200 , for instance a shovel, removes ore from the ore body 100 at the mine face 101 . The mobile excavator 200 transfers the ore to a mobile comminutor 500 before it is transported to the mobile slurry facility 800 . The ore is deposited into the apron feed hopper 520 of the mobile comminutor 500 that feeds an apron feeder 530 to deliver the mined ore to primary comminuting rolls to comminute, or crush, the ore down to transportable size. The apron feed hopper 520 serves the dual purpose of receiving the excavated ore and acting as a “dry” surge or inventory of excavated ore by receiving buckets of excavated ore and delivering a steady stream of excavated ore to the primary comminuting rolls. The comminuted ore falls onto the discharge conveyor 550 for conveyance from the mobile comminutor 500 to a mobile mining conveyor hopper 570 for delivery to mobile mining conveyor 580 . The mobile mining conveyor 580 conveys the comminuted ore to a transfer conveyor that delivers the ore to the mobile slurry facility 800 .
Referring to FIG. 4 , a side view of the excavation portion of the present invention is shown. The mobile excavator 200 is within close proximity of an ore body 100 and within operational reach of a mine face 101 . The mobile excavator 200 excavates ore from the mine face 101 . Prior to transport, the excavated ore must be sized and screened for reject material such as metal. The mobile excavator 200 directs the excavated ore to the mobile comminutor 500 which comminutes and screens the ore. Generally, the mobile comminutor 500 preferably includes tracks 510 , an apron feeder hopper 520 , an apron feeder 530 , primary comminuting rolls 540 and a discharge conveyor 550 . Cable reels 575 transported by the mobile mining conveyor hopper 570 , supply power and communication cables to the excavator 200 , and mobile comminutor 500 .
FIG. 5 is an illustration of the preferred embodiment of a mobile comminutor 500 according to the present invention. The ore is initially deposited by the excavator 200 into the apron feeder hopper 520 which directs the ore onto an apron feeder 530 . The apron feeder 530 conveys the ore to the primary comminuting rolls 540 which comminutes the ore down to a conveyable size typically limiting ore pieces to a diameter of approximately less than about 350 mm. The apron feeder 530 and primary comminuting rolls 540 also preferably includes at least two level detectors. The feeder level detector 532 is directed down the apron feeder 530 to detect large lumps of ore travelling up the apron feeder 530 . When a large lump is detected, the feeder level detector 532 alerts the apron feeder 530 to slow down, to allow the material to be processed by the primary comminuting rolls 540 . Similarly, sizing level detector 534 is directed across the primary comminuting rolls 540 to detect a build-up of material at the primary comminuting rolls 540 . If the level of ore begins to build up above the primary comminuting rolls 540 , the comminuting level detector 534 alerts the apron feeder 530 to slow down the delivery of ore to allow time for the primary comminuting rolls 540 to process the built up ore. Preferably the speed of the apron feeder 530 is also controlled by a weight sensor located on the discharge conveyor 550 . By controlling the speed of the apron feeder 530 using the level detectors and weight sensor, a steady supply of transportable sized ore may be provided to the mobile mining conveyor 580 . Optionally, heaters 522 may be provided at the hoppers and elsewhere as required to minimize build-up of ore when operating under extreme cold conditions.
The mobile comminutor 500 preferably includes tracks 510 to permit relocation of the mobile comminutor as the excavator 200 works the ore body. FIGS. 19 a to 19 c illustrate an embodiment where the mobile comminutor 500 relocates each time the excavator 200 relocates to work a section of the ore body. As illustrated in FIGS. 19 a to 19 c , the excavator 200 excavates all ore within its operational reach at a particular location, and then relocates closer to the newly exposed mine face 101 . As the excavator 200 relocates, the comminutor 500 and mobile mining conveyor hopper 570 also relocate to pace the excavator 200 . In the embodiment of FIGS. 19 a to 19 c the mobile comminutor 500 takes multiple short relocation steps at the same time that the excavator is relocating.
FIGS. 20 a and 20 b illustrate an alternate embodiment in which the excavator 200 excavates all ore within its operational reach at a particular location, and then relocates closer to the newly exposed mine face 101 , but remaining within operational reach of the mobile comminutor 500 . In this fashion, the excavator takes multiple relocation steps excavating about the mobile comminutor 500 location until all ore within operational reach of the mobile comminutor 500 has been excavated. Once the ore has been excavated, both the mobile comminutor 500 relocates to a new location closer to the newly exposed mine face 101 . In the embodiment of FIGS. 20 a and 20 b , the mobile comminutor 500 takes less relocation steps to access all ore within operational reach of the mobile mining conveyor 580 . The excavator 200 may, however, take additional relocation steps or face some periods of down time while waiting for the mobile comminutor 500 to relocate closer to the newly exposed mine face 101 .
Optionally the mobile comminutor 500 includes supports 515 that are preferably lowered during operation while the excavator 200 is working a section of the ore body 100 to stabilise the mobile comminutor 500 . The supports 515 may preferably be raised to permit the mobile comminutor 500 to relocate when the excavator 200 moves to a new section of the ore body 100 . It will be appreciated that supports 515 may be replaced by additional tracks 510 , or dispensed with entirely, depending upon the weight distribution and stability of the mobile comminutor 500 .
The sized ore is directed to a discharge conveyor 550 for delivery to the mobile mining conveyor 580 . Ore that is too large, or too hard to be crushed in the primary comminuting rolls 540 , is directed to a reject door and discharged out the reject chute to the ground below the mobile comminutor 500 . Preferably the ore is also screened at the mobile comminutor 500 for metal contaminant, such as excavator teeth. As will be appreciated, other methods of screening the ore for metal and discarding metal are possible, such as screening the ore downstream after conveyance by the mobile mining conveyor 580 . Most preferably, however, the mobile comminutor 500 includes a metal detector 552 to examine the sized ore on the discharge conveyor 550 for metal contaminants. If metal is detected by metal detector 552 , the apron feeder 530 and discharge conveyor 550 may be temporarily halted and a reject chute in the mobile mining conveyor hopper 570 may be aligned under the discharge point of the discharge conveyor 550 . The discharge conveyor 550 then advances until the metal is discarded off the discharge conveyor 550 and into the reject chute. The discharge conveyor 550 is then temporarily halted again while the mobile mining conveyor hopper 570 is re-aligned to direct discharged ore to the mobile mining conveyor 580 .
Referring to FIG. 6 , the sized ore is first delivered to a mobile mining conveyor hopper 570 by the discharge conveyor 550 . The mobile mining conveyor hopper 570 preferably traverses along rails or tracks that run the length of the mobile mining conveyor 580 . As the excavator 200 advances along the mine face, the mobile comminutor 500 follows the progress of the excavator. The mobile mining conveyor hopper 570 traverses along the transfer conveyor 580 to receive the crushed ore from the discharge conveyor 550 and deliver it to the mobile mining conveyor 580 for conveyance. Preferably, the mobile mining conveyor hopper 570 conveniently includes cable reels 575 to spool out power and communication cables to the mobile comminutor 500 and excavator 200 as they traverse along the mine face 101 . In this manner, the power generation or transmission connection may be conveniently located at the discharge end 590 , of the mobile mining conveyor 580 , minimizing the need to move such equipment. The mobile mining conveyor 580 also preferably comprises crawler tracks 600 distributed along the length of the conveyor which enables the mobile mining conveyor 580 to advance laterally or to advance about and end of the mobile mining conveyor 580 . Optionally, the mobile mining conveyor 580 may be accompanied by a fluid trailer 585 that supplies water or glycol to be sprayed on the transfer conveyor 580 belt to prevent material from sticking to the belt in extreme weather conditions.
In a preferred embodiment the mobile mining conveyor 580 is comprised of multiple conveyor sections that are connected together to create a chain of conveyor sections that collectively comprise the mobile mining conveyor 580 . A continuous belt is supported by the sections to convey ore to the discharge end of the mobile mining conveyor 580 . Preferably, each section includes at least one crawler track 600 to reposition that section. More preferably the crawler tracks 600 are provided with independent height adjustable supports connecting the crawler tracks 600 to the mobile mining conveyor 580 . In a preferred embodiment the sections are joined by pivot joints and an alignment gauge 585 , such as string pots, is used to determine whether a section is inline with its adjacent sections. If the section is not inline, the section's crawler track 600 is repositioned until the section is inline and horizontal. In this way, the mobile mining conveyor 580 may be advanced generally about the discharge end 590 by manually advancing the free end to a desired location. With the advancement of the free end crawler track, the adjacent section will no longer be inline with the end section. Upon detecting mislevel or misalignment, the adjacent section crawler track is also repositioned to maintain level alignment with the end section. Similarly, the next section in the chain detects a misalignment with the adjacent section and its crawler track is repositioned to maintain level alignment. In this way the mobile mining conveyor 580 may be advanced about the discharge end 590 by manually advancing the free end crawler until it is in operational proximity to the current mine face 101 . Alternatively the crawler tracks 600 may be controlled by a central motion controller to co-ordinate the advancement of all crawler tracks 600 .
One advantage of employing a mobile mining conveyor 580 , over a relocatable conveyor, is that material that spills over the sides of the mobile conveyor does not significantly accumulate in a particular location. Depending upon the duration of operation the amount of spilled material that may accumulate around a relocatable conveyor may be considerable. By mining with a mobile mining conveyor 580 , the process avoids the need to clear spilled material prior to relocating the conveyor.
Referring to FIGS. 7 and 8 , at the discharge end 590 of the mobile mining conveyor 580 , the sized ore is deposited into a transfer conveyor hopper 610 that feeds the sized ore onto a transfer conveyor 620 that transports the material to the feed chute of a mobile slurry facility 800 .
The mobile mining conveyor 580 conveys sized ore along its length to the discharge end 590 . The discharge end 590 is in communication with a discharge point such that as sized ore is discharged off the discharge end 590 , it continues in a projectile motion to the discharge point a short distance from the discharge end 590 . In operation the mobile mining conveyor 580 is positioned such that the discharge point of the mobile mining conveyor is aligned with a target, in this case approximately the center of the transfer conveyor hopper 610 . Preferably a location sensor is included to assist in locating the discharge point of the mobile mining conveyor 580 central to the transfer conveyor hopper 610 , and maintaining its alignment with respect to transfer conveyor hopper 610 , while advancing the mobile mining conveyor 580 about the discharge end 590 .
According to a preferred embodiment of the present invention, the mobile mining conveyor 580 consists of multiple independent sections. One of the advantages of the preferred embodiment is that each section may be individually powered and operated depending upon the location of the mobile mining conveyor hopper 570 . Similarly, since each section is independently mobile, each section may be replaced as necessary if it breaks down while in service. Alternatively, a section may be removed from the mobile mining conveyor 580 and operation may continue, albeit with a mining conveyor of shorter length. Preferably the conveyor belt is a continuous belt as known in the art. Conveyor sections may be added or removed by adding or removing sections of the belt to accommodate the change in the length of the conveyor.
In a preferred embodiment the location sensor is optical sensor 595 located at the discharge end 590 that monitors the location of a positioning ring 605 located around the transfer conveyor hopper 610 . As the mobile mining conveyor 580 is advanced about the transfer conveyor hopper 610 , the optical sensor 595 monitors the location of the positioning ring 605 and provides feedback to control the advancement of the tracks 600 on the discharge conveyor section 597 so as to maintain the discharge point in the transfer conveyor hopper 610 . Since the discharge end 590 is located with reference to the transfer conveyor hopper 610 , the geometry of the transfer conveyor hopper 610 may effect the path through which the discharge end 590 , and hence the mobile mining conveyor 580 , may travel. For instance, the transfer conveyor hopper 610 may be circular in which case the discharge end 590 will travel in a generally circular fashion. Alternatively, the transfer conveyor hopper 610 may be elongate in which case the discharge end 590 may travel in a generally arcuate fashion.
As described above, the mobile mining conveyor 580 conveys the sized ore off the discharge end 590 to a discharge point aligned with the transfer conveyor hopper 610 of a transfer conveyor 620 for delivery to the mobile slurry facility 800 where it is converted into a slurry and pumped into pipe-line 850 for transport to a de-sanding facility en route to a bitumen upgrader facility. Since the mobile mining conveyor 580 advances about the transfer conveyor hopper 610 , the transfer conveyor 620 may remain stationary throughout the execution of an operational arc. Preferably the transfer conveyor 620 is provided with a platform 630 on its underside for engaging a crawler when the transfer conveyor 620 is to be repositioned. In this embodiment it is unnecessary to include a motive drive on the transfer conveyor 620 since it remains stationary for extended periods of time.
Referring to FIGS. 9 a - 9 b , preparation of an ore body according to a preferred embodiment of the present invention is presented. Preferably, the ore body is prepared by initially excavating a “pocket” 55 into the mine face 101 with the excavator 200 and mobile comminutor 500 to remove all of the ore within operational reach of the excavator 200 and mobile comminutor 500 while a discharge point off the discharge conveyor 550 is located outside the pocket 55 being excavated. The purpose of excavating the pocket 55 is to permit location of the mobile slurry facility 800 as close as possible to the mine face to facilitate removing the greatest possible volume of ore while the mobile slurry facility 800 remains in a single location. While it is possible to operate the excavator 200 and mobile comminutor 500 further into the ore body beyond the operational reach of the excavator 200 and mobile comminutor 500 , limiting excavation to their operational reach with the discharge point being located outside the pocket 55 minimises the need to employ additional equipment to transport the ore clear of the pocket 55 .
As illustrated in FIG. 9 c , after excavation of the initial pocket, the mobile slurry facility 800 and transfer conveyor 620 may be positioned such that the transfer conveyor hopper 610 is located in the pocket, thus locating the mobile slurry facility 800 at an optimal location for removing a maximum volume of ore before having to move the mobile slurry facility 800 . Optionally, as illustrated in FIG. 9 c , the excavator 200 and mobile comminutor 500 may continue to work the ore body to enlarge the pocket 55 without the mobile mining conveyor 580 by locating a discharge point off the discharge conveyor 550 in the apron feed hopper 610 . An additional volume of the ore body is within operational reach of the excavator 200 and mobile comminutor 500 when the discharge point is located in the transfer conveyor hopper 610 within the pocket 55 . The advantage of excavating an enlarged pocket by delivering the ore directly from the mobile comminutor 500 to the transfer conveyor hopper 610 is that it consumes less energy and results in less wear and tear on equipment. Optionally, the ore excavated during the initial pocket excavation, illustrated in FIGS. 9 a - 9 b , may be fed into the mobile slurry facility 800 at this time by depositing the ore in the transfer conveyor hopper 610 . Alternatively, the initially excavated ore may be retained as a dry surge to feed to the mobile slurry facility during excavation down time such as excavator shovel repairs or conveyor maintenance.
Referring to FIGS. 10 a - 10 e a top view schematic of the process of the present invention is presented. FIG. 10 a illustrates a close-up top view of a mining cell according to an embodiment of the present invention with the ore body 100 and the mobile mining conveyor 580 in an initial position. The excavator 200 removes ore from a mine face 101 and delivers it to a mobile comminutor 500 by depositing it in the apron feed hopper 520 to be directed to an apron feeder 530 . The apron feeder 530 carries the ore to primary comminuting rolls 540 , not shown in this view, for crushing before the ore is directed to the discharge conveyor 550 to be transferred to the mobile mining conveyor hopper 570 to direct the ore to the mobile mining conveyor 580 for delivery off the discharge end 590 of the mobile mining conveyor 580 to a discharge point. Preferably, the mobile mining conveyor 580 is oriented to position the discharge point in a transfer conveyor hopper 610 . Most preferably the mobile mining conveyor 580 positions the discharge point at or near the center of the transfer conveyor hopper 610 . The transfer conveyor hopper 610 supplies the conveyable ore to a transfer conveyor 620 that delivers the ore to a mobile slurry facility 800 . The mobile slurry facility 800 adds HPW to convert the ore into a slurry that is pumped into a pipe-line 850 for hydro-transport.
FIG. 10 b illustrates the mining cell in a top view with the ore body 100 to be excavated and the excavator 200 , mobile comminutor 500 and mobile mining conveyor hopper 570 starting at an end of the mobile mining conveyor 580 and removing ore within operational reach along the length of the mobile mining conveyor 580 .
FIG. 10 c illustrates the mining cell in a top view after all the ore within operational reach of the mobile mining conveyor 580 in the first position has been excavated and the conveyor has been advanced about the discharge end 590 to position a further section of ore within operational reach of the mobile mining conveyor 580 while locating the discharge point in the transfer conveyor hopper 610 . As illustrated, once the mobile mining conveyor 580 has been advanced, the excavator 200 , mobile comminutor 500 and mobile mining conveyor hopper 570 move along the mobile conveyor 580 and excavate the ore within operational reach of the mobile mining conveyor 580 . After all the ore within operational reach of the mobile mining conveyor 580 has been excavated, the mobile mining conveyor 580 is again advanced about the discharge end.
FIG. 10 d illustrates the mining cell in a top view with the ore body 100 and the mobile mining conveyor 80 having been advanced to a further position and the excavator 200 , mobile comminutor 500 and mobile mining conveyor hopper 570 having completed excavating all the ore within operational reach of the mobile mining conveyor 580 in the further position.
FIG. 10 d illustrates the mining cell in a top view with the ore body 100 and the mobile mining conveyor 80 having been advanced to a further position and the excavator 200 , mobile comminutor 500 and mobile mining conveyor hopper 570 having completed excavating all the ore within operational reach of the mobile mining conveyor 580 in the further position.
FIG. 10 e illustrates the mining cell in a top view with the ore body 100 and mobile mining conveyor 80 having been advanced through an operational arc about the discharge end and the excavator 200 and mobile comminutor 500 having excavated, comminuted and transferred to the mobile mining conveyor hopper 570 an operational arc sector of ore.
FIG. 10 f illustrates the mining cell in a top view with the ore body 100 after the excavator 200 and mobile comminutor 500 have prepared an initial pocket at the perimeter of the excavated arc sector. The mobile slurry facility 800 has been moved from its prior location to be in close proximity to the mine face 101 with the transfer conveyor 620 located in the pocket. The excavator 200 and mobile comminutor 500 are initiating excavation of an enlarged pocket about the transfer conveyor hopper 610 . The mobile mining conveyor 580 has been positioned in close proximity to the mobile slurry facility 800 and transfer conveyor 620 to begin operation after the excavator 200 and mobile comminutor 500 have completed the enlarged pocket.
FIG. 11 illustrates the mining cell in a top view with the ore body 100 after the mobile mining conveyor 580 has been advanced through an operational arc sector about a mobile slurry facility 800 . In comparison to the embodiment illustrated, a conventional fixed conveyor 575 of similar length is illustrated with the operational reach of the conventional fixed conveyor 575 illustrated with cross-hatching 585 . As will be appreciated the effective length of the mobile mining conveyor 580 is greater than that of a conventional fixed conveyor 575 since a greater volume of ore may be excavated before relocating the mobile slurry facility 800 with a mobile mining conveyor 580 according to the present invention.
As described above, the discharge end 590 of the mobile mining conveyor hopper 580 delivers conveyable ore to the transfer conveyor hopper 610 of the transfer conveyor 620 . The transfer conveyor 620 supplies the conveyable ore to the mobile slurry facility 800 . Since the mobile slurry facility 800 preferably utilises gravity to assist in slurrying the ore, the transfer conveyor 620 serves to elevate the conveyable ore to the height of the mobile slurry facility 800 ore input chute. The use of a transfer conveyor 620 to offset the mobile slurry facility 800 from the discharge end 590 also provides the opportunity to increase the operational arc of the mobile mining conveyor hopper 580 . Furthermore, a single mobile slurry facility 800 may be used to process ore from multiple mobile mining conveyors 580 . In such an embodiment, the transfer conveyor 620 may be longer than the minimum length required for supplying conveyable ore to a mobile slurry facility 800 fed by a single mobile mining conveyor 580 .
FIG. 18 a is an illustration of a mobile mining conveyor 580 combined with an extended transfer conveyor 623 feeding the transfer conveyor 620 . The embodiment of FIG. 18 a allows a mobile mining conveyor 580 to access a greater volume of ore before the mobile slurry facility 800 requires relocation. An additional feature of traversing the mobile mining conveyor 580 along the extended transfer conveyor 623 before rotating the mobile mining conveyor 580 about the distal end 623 b of the extended transfer conveyor 623 , is that it provides access to a section of ore body having straight sides. Among other uses, such an arrangement may be useful to access a volume of ore from a given mobile slurry facility 800 location when the ore body is of a relatively narrow width. The extended transfer conveyor 623 allows a larger volume of ore to be accessed than would otherwise be the case for the mobile mining conveyor 580 of a given length.
FIG. 18 b illustrates an embodiment where a single mobile slurry facility 800 may be used to process ore from multiple mobile mining conveyors 580 a , 580 b . In the embodiment illustrated, two mobile mining conveyors 580 a , 580 b access adjacent volumes of ore. Each of the discharge ends 590 a , 590 b pivot about a separate discharge point for transferring ore to conveyors 625 a , 625 b that convey the mined ore to their discharge ends 592 a , 592 b to feed transfer conveyor 620 . The discharge points may be fixed at a point along the conveyors 625 a , 625 b , as illustrated in FIG. 18 b , or alternatively as illustrated in FIG. 18 f , mobile conveyor hoppers may be used to allow the discharge points to traverse along the conveyors 625 a , 625 b . After the mobile mining conveyors 580 a , 580 b have completed an arc sector as suggested in FIG. 18 b , one of the mobile mining conveyors 580 a , 580 b may be positioned to pivot about a discharge end 592 c located at the transfer conveyor 620 to remove a further section of ore between the arc sectors illustrated within reach of the mobile mining conveyors 580 a , 580 b . The embodiment of FIG. 18 b allows for a large volume of ore to be processed with a single mobile slurry facility 800 at a location, increasing the time between moves for a given length of mobile mining conveyors 580 a , 580 b . The embodiment may be implemented in a variety of methods, including operating both mobile mining conveyors 580 a , 580 b simultaneously, to feed twice as much ore to the mobile slurry facility 800 , or alternately operating each conveyor to ensure a steady feed of ore, for instance when one conveyor is inoperative, such as when equipment is moving or a shift change occurs.
FIGS. 18 c and 18 d are plan view schematics, illustrating an embodiment where multiple mobile mining conveyors 580 , 581 are deployed in series. The conveyors 580 , 581 may be of similar length, or may comprise different lengths as is convenient for excavating a particular ore body 100 . The excavator 200 and mobile comminutor 500 work the ore body 100 feeding mobile mining conveyor hopper 571 . The use of multiple mobile mining conveyors 580 , 581 allows for efficient mining of an ore body, including avoiding low yield volumes 105 (shown in plan views as an area). As illustrated in FIG. 18 c , the mobile mining conveyor 580 may be deployed as a face conveyor to allow mobile mining conveyor 581 to pivot about the mobile mining conveyor hopper 570 to access ore around the low yield volume 105 . FIG. 18 d illustrates an embodiment where the mobile mining conveyor 580 is pivoting about the transfer conveyor 620 , and the mobile mining conveyor 581 is pivoting about the mobile mining conveyor hopper 570 . In an embodiment, mobile mining conveyor 581 may be advanced through all of the ore within operational reach of the mobile mining conveyor hopper 570 as it traverses along the mobile mining conveyor 580 which is held in a fixed position for the duration of the advancement. Alternatively, the mobile mining conveyors may both be advanced by pivoting about the transfer conveyor 620 providing an effective mobile conveyor length a length equivalent to the combined lengths the mobile mining conveyors 580 , 581 .
FIG. 18 e illustrates an embodiment where multiple mobile mining conveyors 580 , 581 are deployed to excavate ore along mine wall limit 102 . As illustrated, the conveyors 580 , 581 may be of differing lengths as required to efficiently mine the wall limit 102 .
FIG. 18 f illustrates an embodiment where multiple conveyors are working an ore body 100 around low yield sections 105 . In the embodiment illustrated, the mobile mining conveyors 580 a and 580 b are of differing length to better work between low yield sections 105 . Mobile conveyor hoppers 570 traverse along conveyors 625 a , 625 b to allow access to minable ore in the ore body 100 and avoid the low yield sections 105 .
A mobile slurry facility 800 converts the conveyable ore delivered by the transfer conveyor 620 into a slurry for hydro-transport. In a preferred embodiment of the mobile slurry facility 800 the conveyable ore is first discharged from the transfer conveyor 620 into the roller screen feed chute 720 . The roller screen feed chute 720 feeds the roller screen 740 to crush the ore to a convenient size for slurrying (typically less than 65 mm in diameter) and allow the crushed and sized ore to fall through the screen. Oversize material that does not fall through the roller screen 740 passes to an oversize comminutor 760 that crushes the lumps of oversize down to acceptable size. Hot Process Water (HPW) is typically introduced at the roller screen feed chute 720 and additional HPW is added directly over the roller screen 740 and oversize comminutor 760 . The additional HPW assists in processing the ore, preventing ore buildup and defining the slurry density. The majority of the wet sized ore passes directly through the roller screen 740 for conversion to slurry in the slurry pump box 780 . The remaining oversize is wetted and crushed by the oversize comminutor 760 before falling into the slurry pump box 780 for conversion to slurry. While it is possible to provide for an overflow chute to discard oversize, it is preferable to size the roller screen 740 and oversize comminutor such that they are capable of processing all of the ore supplied by the transfer conveyor 620 .
Typically, HPW will be proportionately distributed approximately 70% at the roller screen feed chute 720 , 20% at the roller screen 740 and 10% at the oversize comminutor 760 . Where the invention includes a metal detector and reject ore discharge mechanism at the mobile comminutor 500 , all of the ore received by the mobile slurry facility 800 may be processed using the roller screen 740 and oversize comminutor 760 . While it is possible to detect metal in the ore at the roller screen 740 , it is preferable to discard reject material as soon as possible in the process. Furthermore, it is preferable to discard reject material prior to processing by the primary comminuting rolls 540 . One advantage of the combination of the mobile comminutor 500 and mobile slurry facility 800 of the present invention is that reject material is discarded near the location of excavation. As the excavator 200 works an ore body, detected reject material will be discarded near the location of its excavation. Not only does this avoid transporting reject material along the mobile mining conveyor 580 where it can damage equipment but it eliminates the need for reject material handling equipment at the mobile slurry facility 800 where it would be much more difficult to incorporate such equipment.
The sized ore and HPW falls into the slurry pump box 780 that is sized for a slurry retention time of approximately one minute. The slurry pump box 780 supplies the hydro-transport pump 820 with slurry. A one minute retention time is the preferred minimum to provide a wet surge capability to continuously supply slurry to the pump. When the level of slurry falls below a low level, Cold Process Water (CPW) may be added to maintain the level in the slurry pump box and ensure the hydro-transport pump 820 does not cavitate. As required, HPW may be added along with CPW to maintain a working temperature under cold conditions.
Emergency ponds are preferably located near the mobile slurry facility 800 to allow dumping of slurry from the mobile slurry facility 800 or the pipeline 850 under emergency conditions. The size of the emergency ponds is preferably large enough to accommodate the directed drainage of the contained volume of any one of the following: a drainable section of hydro-transport pipeline (24″), a drainable section of HPW pipeline (24″), a drainable section of CPW pipeline (20″), or the volume of the slurry pump box 780 . The size of the drainable sections of the pipelines are site specific due to logistical and geographical features. The emergency pond is preferably serviced by a submersible pump which is able to return the pond fluids back to the process through the slurry pump box at the end of the emergency.
The slurry is pumped through the hydro-transport pipeline 850 to an extraction facility. As mentioned above, in addition to transporting the slurry, the hydro-transport process serves the secondary purpose of conditioning the slurry. The length of hydro-transport required to condition the slurry depends on several factors including the grade of ore, temperature of the ore, temperature of the process water and the size of ore being delivered to the slurry pump box. Typically, to be fully conditioned the slurry requires at minimal distance of one kilometer of hydro-transport distance.
Preferably the extraction facility is a mobile extraction facility 900 that receives as inputs the conditioned slurry as an ore slurry feed 1200 and process water 1205 , and produces as outputs an enriched bitumen stream 1400 and a tailings stream 1450 . In a preferred embodiment, the mobile extraction facility 900 comprises separate portable modules that may be transported to a location separately and then connected together in series to provide a single extraction facility. Preferably the mobile extraction facility 900 comprises a primary separation facility connected to a froth concentration facility. More preferably, the primary separation facility comprises two or more separate separation cyclone modules that are combinable in situ to comprise the primary separation facility. Most preferably, the primary separation facility comprises three separate separation cyclone modules connected in series in a countercurrent configuration. The use of separate modules allows for ease of portability and allows the process to be flexible to tailor the extraction facility to the ore body being excavated. For instance, a high grade ore body that contains very little fine solids/mineral component may not require the rigor of a three cyclone circuit, and in such a case the extraction facility may comprise only one or two of the modules. Generally, to accommodate all ore types, a three cyclone system is preferred. The modules preferably comprise transportable platforms, such as skids, that may be transported by crawlers or other motive modules. Alternatively, the modules may be provided with driven tracks.
In an alternate embodiment, the mobile extraction facility 900 comprises a single facility, containing all separation vessels and primary froth concentration equipment.
Use of a three stage cyclonic system is further advantageous in a mobile extraction system for several reasons. First, the size of each individual cyclone stage may be reduced since a three stage counter—current process results in a separation efficiency either equivalent to, or better than, current extraction methods. Second, each of the three cyclones may be transported separately, greatly improving the ease of relocating the extraction facility. Third, the use of a three stage countercurrent cyclonic system allows a mobile extraction facility to operate with a variety of ore grades. Fourth, as mentioned above, the number of stages may be tailored to match the separation efficiency with the grade of ore being processed.
As described above, the slurry that is fed to mobile extraction facility 900 is generally formed using HPW. In conventional bitumen extraction equipment such as primary separation vessels (PSV), where bubble attachment and flotation are used for bitumen extraction, temperature can affect the efficiency of the extraction process. In the preferred extraction embodiments described above, the extraction process is not as temperature sensitive since the cyclone equipment provides solid/liquid separation based on rotational effects and gravity. Extraction efficiency tends to be maintained even as temperature drops making the cyclone extraction process more amendable to lower temperature extraction. This has energy saving implications at the mobile extraction facility 900 where water feed 1305 or recycled water stream 1370 do not have to be heated to the same extent as would otherwise be necessary to maintain a higher process temperature.
Preferably each of the cyclone separation modules are self-contained and include a cyclone, as well as associated connections, pump boxes, and pumps. This way, if one unit has a mechanical failure, the extraction facility may be brought back online by simply replacing the faulty cyclone separation unit. Preferably the cyclone separation modules are connected in series in a countercurrent configuration in which the water stream and slurry stream enter at opposite ends of the three cyclone combination. Thus, for example, water entering the process (either make-up, recycled, or both) is first contacted with a bitumen-lean feed at the last cyclone separation unit in the series. The cyclonic separation units are preferably vertical cyclones, which have a reduced footprint. Suitable cyclonic separation vessels include those manufactured by Krebs Engineers (www.krebs.com) under the trade-mark gMAX.
This modular arrangement of the extraction system provides for both mobility of the system and flexibility in efficiently handling of different volumes of ore slurry. For example, as illustrated in FIG. 17 , a preferred setup according to an aspect of the invention in which each cyclone separation stage 106 , 108 and 110 is mounted on its own independent skid 160 to form a mobile module. Positioned between each cyclone separation stage skid 160 is a separate pump skid 162 which provides appropriate pumping power and lines to move the froth streams and solid tailings streams between the cyclone separation stages. It is also possible that any pumping equipment or other ancillary equipment can be accommodated on skid 160 with the cyclone separation stage. In the illustrated arrangement of FIG. 17 , groups of three mobile modules are combinable together to form cyclone separation facilities 102 , 102 ′, 102 ″ to 102 n as needed. Also associated with each cyclone separation facility is a mobile froth concentration facility 130 mobile modules comprising skids or other movable platforms with appropriate cyclone stage or froth concentration equipment on board may be assembled as needed to create additional mobile extraction systems 200 ′, 200 ″ to 200 n to deal with increasing ore slurry flows provided by hydro-transport line 850 . Ore slurry from the transport line 850 is fed to a manifold 103 which distributes the slurry to a series of master control valves 165 . Control valves 165 control the flow of ore slurry to each mobile extraction system 200 to 200 n . This arrangement also permits extraction systems to be readily taken off-line for maintenance by switching flow temporarily to other systems.
According to a preferred embodiment, the cyclone separation units 1210 , 1220 , 1230 are connected as illustrated in FIG. 12 . The slurry is delivered by the hydro-transport pipeline 850 as an ore slurry feed 1200 to the first cyclone separation unit 1210 . The first cyclone 1210 separates the ore slurry feed 1200 into a first bitumen froth stream 1300 and first tailings stream 1310 . The first tailings stream 1310 is pumped to a feed stream of a second cyclone 1220 . The second cyclone 1220 produces a second bitumen froth stream 1320 and a second tailings stream 1330 . The second bitumen froth stream 1320 is combined with the ore slurry feed 1200 as the feed stream of the first cyclone 1210 . The second tailings stream 1330 is combined with a water feed 1305 as the feed stream of a third cyclone 1230 . The third cyclone 1230 produces a third bitumen froth stream 1340 and a third tailings stream 1350 . The third bitumen froth stream 1340 is combined with the first tailings stream 1310 as the feed stream of the second cyclone 1220 . The third tailings stream 1350 from the third cyclone 1230 forms a tailings stream 1400 that is pumped to a tailings treatment facility 1100 .
Optionally a “scalping” unit 1205 , such as a pump box or the like, may be included on the ore slurry feed 1200 to remove any froth formed in the slurry feed 1200 during the hydro-transport process and divert the bitumen froth directly to be combined with the first bitumen froth stream 1300 . Removal of the bitumen rich froth at the scalping unit 1205 assists in further increasing the recovery efficiency of the primary separation facility. Preferably, as indicated, the scalping unit 1205 is located upstream of the infeed of the second bitumen froth stream 1320 .
The first bitumen froth stream 1300 is directed to a froth concentration facility to reduce the water content, remove remaining fines, and produce an enriched bitumen product stream 1400 . Preferably, the froth concentration facility is located proximate to the primary separation facility. Most preferably, the froth concentration facility comprises a separate portable unit that may be combined with the primary separation facility units to comprise the mobile extraction facility 900 . Typically the froth concentration facility comprises at least a froth concentration vessel 1240 , such as a flotation column, a horizontal decanter, an inclined plate separator, or other similar device or system known to be effective at concentrating bitumen froth. In addition to the first bitumen froth feed, an air feed 1355 or chemical additive stream may also be introduced into the froth concentration vessel 1240 . Optionally the froth concentration facility may comprise a combination of effective devices. In a preferred embodiment, as illustrated in FIG. 12 , the froth concentration vessel 1240 comprises a flotation column. In a further preferred embodiment for a mobile extraction facility a horizontal decanter is used to separate an enriched bitumen stream from the first bitumen froth stream. The selection of a series of countercurrent cyclone separators results in a compact separation facility that remains able to remove the majority of the mineral component from the ore slurry feed 1200 . The low solids content of the first bitumen froth stream permits the use of a horizontal decantor as the froth concentration vessel with a low risk of plugging due to sedimentation. Use of a horizontal decantor is desirable due to its small footprint, thus allowing for the potential of the vessel being made movable, and still result in a robust extraction facility that has a low propensity of being fouled with silt or other mineral component.
Within the froth concentration vessel 1240 , the froth is concentrated resulting in an enriched bitumen froth product stream 1400 , that may optionally be transported to a secondary separation facility (not shown) to increase the hydrocarbon concentration in the froth before being pumped to an upgrader facility. Typically, the secondary separation facility will be a larger, more permanent facility. One advantage of the process of the present invention is that an enriched bitumen froth stream 1400 is produced relatively close to the excavation site, greatly reducing the current requirement to transport large volumes of water and mineral component to the permanent separation facility.
Froth concentration vessel 1240 also produces a fine tailings stream 1360 that comprises water and fine solids contained in the first bitumen froth stream 1300 . In one embodiment, any known chemical additives may also be used in the froth concentration facility to enhance the separation of fines from the water.
Preferably the fine tailings stream 1360 is diverted to a water recovery unit 1250 , which separates the fine tailings stream 1360 into a recycled water stream 1370 and a fine tailings stream 1380 . In a preferred embodiment, the water recovery unit 1250 is a hydrocyclone to separate small sized particulate since the majority of the mineral component is removed by the primary separation facility. The fine tailings stream 1380 is preferably combined with the third tailings stream 1350 to produce a tailings stream 1450 from the mobile extraction facility 900 . The recycled water stream 1370 is preferably combined with the water feed 1305 for input to the third cyclone. As necessary, the recycled water stream 1370 may also be combined with the third tailings stream 1350 , fine tailings stream 1380 or tailings stream 1450 as necessary to control the water content of the streams. Preferably density meters (not shown) monitor the streams to determine whether, and how much, recycled water 1370 should be added. The addition of water to the third tailings stream 1350 and tailings stream 1450 may be necessary to maintain a pumpable stream, as the primary separation facility removes most of the water from the third tailings stream 1350 and fine tailings stream 1380 . The water recovery unit 1250 provides significant efficiencies in that the process water used in the mobile extraction facility 900 is preferably heated. The recycled water stream 1370 is typically warm or hot, so that reintroducing the recycled water stream 1370 reduces the heat lost in the extraction process.
An advantage of this preferred embodiment of the present invention is that water may be recycled in the extraction process, and the mobile extraction facility 900 produces a single tailings stream 1450 .
In a further optional embodiment, the ore slurry feed 1200 may be provided with any number of known additives such as frothing agents and the like prior to being fed to the primary separation facility to prepare the ore slurry feed 1200 for extraction. An example of such additives would be caustic soda, geosol, or other additives as described in U.S. Pat. No. 5,316,664.
As mentioned above, the tailings stream 1450 is pumped to a tailings treatment facility 1100 . The tailings treatment facility 1100 may be located at the mobile extraction facility 900 , or some distance from the mobile extraction facility 900 depending upon the availability of a tailings deposition site 1150 . As will be appreciated, the location of the tailings deposition site 1150 is preferably close to the mobile extraction facility 900 to minimize the distance the tailings stream 1450 must be transported. However, the tailings treatment facility 1100 may be located distant from the mobile extraction facility 900 if it is necessary to locate the tailings deposition site 1150 at a distant location.
While the tailings treatment facility 1100 may comprise a known method or process of handling tailings, preferably tailings treatment facility 1100 comprises the addition of a rheology modifier or other such additive to the tailings stream 1450 prior to deposition at the tailings deposition site. An example of a suitable additive is described in PCT publication WO/2004/969819 to Ciba Specialty Chemicals Water Treatment Limited.
In a further preferred embodiment, the third tailings stream 1350 and fine tailings stream 1380 are mixed to ensure a homogenous distribution of coarse and fine particulate in the tailings stream 1450 . A preferred additive is a rheology modifier additive such as a water soluble polymer that may be added and mixed with the tailings stream 1450 to produce a treated tailings stream. The additive may be mixed into the tailings stream 1450 either during a pumping stage, or subsequently added in liquid form near the tailings deposition site. Preferably the treated tailings are deposited at the tailings deposition site and allowed to stand and rigidify thereby forming a stack of rigidified material. The addition of the additive results in a whole dry tails that rigidities relatively quickly to produce a relatively homogenous tailings deposition. After application of the additive, the water separates from the mineral component free from the fines. Unlike conventional tailings ponds, after addition of the additive the treated tailings produced according to the present invention releases water that is sufficiently clear to be recycled as industrial process water almost immediately after tailings deposition. Furthermore, the recycled industrial process water is often still warm, reducing the energy required to be added to produce hot process water. The industrial process water may be recycled back into the mobile extraction facility 900 , the mobile slurry facility 800 or other industrial processes as required. Furthermore, after separation of the water, the mineral component is comprised of both sand and fines, and is thus more stable than typical tailings produced by known processes. This provides the unique opportunity to reclaim the solid tailings relatively soon after excavation.
A suitable mobile slurry facility may comprise the slurry apparatus 10 illustrated in FIGS. 13 to 16 and further described in Applicants' previously co-pending application No. 11/558,303, filed Nov. 9, 2006, entitled METHOD AND APPARATUS FOR CREATING A SLURRY (published as U.S. Patent Application Publication No. 2007/0119994 and now issued as U.S. Pat. No. 7,651,042), claiming priority from Canadian Patent Application No. 2,526,336.
As shown in FIG. 13 , the slurry apparatus 10 provides a frame 20 having a base 22 . The frame 20 may optionally also be provided with sides 24 . The frame 20 is preferably formed from steel girders or I-beams having the required load-bearing capacity, welded, bolted, or otherwise suitably affixed together. The frame supports a slurry box 30 , which may be a conventional slurry box constructed to support the desired slurry load. The slurry box 30 essentially acts as a wet surge, maintaining the required constant supply of slurry to the slurry pump 39 . The slurry box 30 provides a slurry outlet 38 which feeds the slurry pump 39 , and the slurry pump 39 in turn provides a slurry outlet 41 to which a hydrotransport conduit (not shown) is detachably coupled by suitable means, for example a bolted flange.
An ore size regulating apparatus such as a screen or comminuting apparatus 50 is suspended above the slurry box 30 . For example, in the preferred embodiment the comminuting apparatus may be a screening/sizing roller screen such as that described in Canadian Patent Application No. 2,476,194 entitled “SIZING ROLLER SCREEN ORE PROCESSING” published Jan. 30, 2006, which is incorporated herein by reference, which both screens and crushes ore. In the preferred embodiment the comminuting apparatus 50 is supported on the frame 20 of the slurry apparatus 10 , with the output face of the comminuting apparatus 50 in communication with the open top of the slurry box 30 such that comminuted ore fed to the comminuting apparatus 50 is directed into the slurry box 30 under the force of gravity. Alternatively, as screen may be provided to screen the incoming ore flow as an initial step before crushing.
Because the slurry apparatus 10 according to the invention is movable, it is advantageous to maintain a low centre of gravity in the slurry apparatus 10 and therefore if the comminuting apparatus 50 is suspended above the slurry box 30 it is advantageous to provide the comminuting apparatus 50 as close as possible (vertically) to the open top of the slurry box 30 . The comminuting apparatus 50 may be oriented close to the horizontal, or alternatively may have either a positive or negative angle to the horizontal. In a preferred embodiment the comminuting apparatus 50 is oriented at an angle to the horizontal such that comminuted ore is fed at the higher end of the comminuting apparatus 50 . The comminuting apparatus 50 may be supported on its own separate frame, may be solely supported by a side 24 of the slurry apparatus frame 20 , or may be supported on the slurry box 30 . Alternatively, the comminuting apparatus 50 may be in communication with the slurry box 30 via one or more interposed conveyor mechanisms, such as a transfer conveyor (not shown).
The comminuting apparatus 50 may alternatively be housed in a separate structure and maintained in communication with the slurry box 30 by a conveying apparatus such as a transfer conveyor (not shown). Similarly, while the illustrated embodiment shows the slurry pump 39 and electrical transformers 9 housed in the structure of the slurry facility 10 , it is possible to house these components in one or more separate structures that are detachably connected to the relevant systems in the slurry facility 10 when the slurry facility 10 is in operating mode. It is advantageous to provide transformers 9 within or immediately adjacent to the slurry facility 10 , which will gradually be moved away from any permanent transformer substation as mining progresses.
A water supply 60 , for example a hood with a spray header (shown in FIG. 14 ), is positioned to apply hot process water to the ore as it is fed into the comminuting apparatus 50 , assisting in the comminuting process and so that ore is already wetted when it enters slurry box 30 . As is well known in the art, the hot process water is mixed with the ore in a proportion which provides the desired slurry consistency for conditioning during transport to an extraction facility. The water supply 60 may be provided in any convenient location for dispensing the process water over the ore, preferably before comminution or optionally after comminution.
The slurry box 30 is mounted to the floor 22 of the slurry apparatus frame 20 in the desired position. As illustrated in FIG. 14 , the frame 20 is supported on a first set of spaced apart support points 21 , for example adjacent to the corners where the sides 24 meet the base 22 , which may be mounted on crane mats 23 as in the embodiment illustrated in FIGS. 13 and 14 , to support the frame 20 in stationary mode, or alternatively may be mounted on pontoons 27 or other suitable support. The slurry box 30 may be disposed anywhere within the frame 20 , as long as the centre of gravity CG 1 of the slurry apparatus 10 when the slurry box 30 is filled is within the area bounded by the first set of spaced apart support points 21 (as shown in FIG. 14 ).
The frame 20 further contains other apparatus incidental to the operation of the slurry facility, which may for example include a gland water supply for the slurry pump 39 , cooling units for conditioning the air within the facility to make it suitable for workers, electrical transformers for powering the equipment used in the slurry facility 10 , safety equipment, overhead cranes for maintenance and so on. The distribution of equipment about the frame 20 of the slurry apparatus 10 determines a first center of gravity CG 1 for the slurry apparatus 10 in a stationary mode, in which the slurry box 30 is filled and operational. Preferably the amount and size of equipment are minimized to keep the weight of the facility 10 as low as possible; for example, the facility 10 may house a single hydrotransport pump 39 (or the hydrotransport pump 39 may be supported on a separate structure as noted above). The heaviest equipment should be as low as possible within the frame 20 , to keep the centre of gravity CG 1 and CG 2 low. In the stationary mode, when the frame 20 is supported on the first set of spaced apart support points 21 and the slurry box 30 is filled with slurry and operational, a considerable additional amount of weight is concentrated in the region of the slurry box 30 , which determines the position of the first center of gravity CG 1 . The frame 20 thus supports all the on-board equipment, plus the weight of the slurry, on the first set of spaced apart support points 21 .
In a moving mode, with the slurry box 30 empty, the centre of gravity is disposed at CG 2 . The base 22 of the frame 20 is provided with a lifting region 70 , shown in FIG. 15 , which is formed by a series of beams affixed to the main girders 28 of the base 22 . The entire slurry apparatus 10 can thus be lifted by a single moving device such as a mobile crawler 80 , for example that produced by Lampson International LLC (hereinafter referred to as a “Lampson Crawler”), lifting solely at the lifting region 70 , without substantial deformation of the frame 20 . The lifting region 70 defines a second set of spaced apart support points 72 , which is directly beneath (and preferably centered under) the second center of gravity CG 2 . The Lampson Crawler, which is essentially a hydraulic lifting platform having a propulsion system and mounted on tracks as illustrated in FIG. 9B , can be positioned under the lifting region 70 using locator tabs 74 , shown in FIG. 15 , and raised to lift the frame 20 while maintaining the stability of the facility 10 .
In the operating mode, ore is fed to the comminuting apparatus 50 in any desired fashion, for example via a transfer conveyor 6 as shown in FIGS. 13 and 4 . Preferably the transfer conveyor 6 is freestanding and not connected to the slurry apparatus 10 , but suspended in communication with the slurry apparatus 10 . The ore is processed by the comminuting apparatus 50 , preferably to reduce the particle size of the entire inflow of ore to a maximum of 2″ to 2½″ (although larger ore sizes can also be processed). The comminuting apparatus 50 may include an oversize comminuting component 52 (shown in FIG. 14 ) to comminute oversized ore and eliminate rejected ore.
The comminuted ore is mixed with water from the water supply 60 and fed into the slurry box 30 . A slurry of the consistency desired for hydrotransport is thus created within the slurry box 30 . The slurry progresses through the slurry box 30 over the selected retention interval and egresses through the slurry outlet to a hydrotransport pump 39 , which in turn feeds the slurry into a hydrotransport outlet 41 to which a line (not shown) is detachably connected for transport to an extraction facility (not shown). The hydrotransport line is detachable from the hydro transport outlet 41 to allow for periodic movement of the slurry apparatus 10 to a new site as the mine face moves away from the slurry apparatus 10 .
The electrical supplies including all power lines (and optionally telecommunications cables) are preferably contained in a power cable that detachably connects to a local connection (not shown) on the slurry facility 10 , which may for example be adjacent to the transformers 9 , to facilitate easy connection and disconnection of all electrical systems to a standard power source remote to the movable facility 10 . Preferably the electrical power system is grounded via cable to a local transformer station or platform, rather than directly into the ground, either via the power cable or via a separate grounding cable, to facilitate detachment and reattachment of the ground connection during the relocation procedure. Similarly, water supplies and connections to fluid outlets (for example emergency pond outlet 45 ) are not welded but are instead detachably coupled via bolted flanges, quick-connect couplings or other suitable detachable connections as desired to facilitate detachment and reattachment during the relocation procedure.
When it is desired to move the slurry apparatus 10 to a new location, the transfer conveyor 6 is deactivated to discontinue the ore flow, and the slurry box 30 is empty and flushed. Preferably the slurry apparatus 10 includes a cold water supply 43 for use in flushing the slurry apparatus (and in case of emergency; an emergency outlet 45 is also preferably provided for directing contaminated water to a nearby emergency pond if needed). When the slurry box 30 has been completely emptied and flushed, the hydrotransport line (not shown) is disconnected from hydrotransport pump 39 .
All electrical and water supplies are disconnected from the apparatus 10 . Once all water supplies and electrical supplies have been disconnected, the slurry apparatus 10 is ready to be moved to a new location.
A path to the new location is prepared, for example by compacting and laying down a suitable bed of gravel, if necessary. The new location is surveyed to ensure it is level (using gravel if necessary to level the site), and in the embodiment illustrated in FIGS. 13 and 14 crane mats are laid optionally covered by metal sheeting (not shown) to avoid point-loading the crane mats 23 . In this embodiment hydraulic jacks 29 are provided generally under the first set of spaced apart support points, supported on the crane mats 23 . The jacks 29 are actuated, either in unison or individually in increments, to raise the frame 20 to a height that will allow a moving device 80 such as a Lampson Crawler, with its hydraulic platform 82 in retracted mode, to be driven beneath the base 22 of the frame 20 and positioned under the lifting region 70 using locator tabs 74 (shown in FIG. 15 ) as a guide to position the hydraulic platform 82 . The hydraulic platform 82 is raised, lifting the entire frame 20 . When the frame 20 has been raised to support the frame the hydraulic jacks 29 are retracted (as shown in FIG. 16 ), the propulsion system in the Lampson Crawler 80 is engaged and the slurry apparatus 10 is moved toward the new location. Preferably the slurry apparatus 10 comprises on-board levels (not shown) at locations visible from the exterior of the apparatus 10 , and/or a water level comprising a flexible tube filled with water and extending across the entire frame 20 (not shown), which are carefully monitored by operators to ensure that the facility 10 remains level within the tolerances permitted by the second set of spaced apart support points 72 (as described below).
As illustrated in FIG. 16 the slurry apparatus 10 may be tilted, preferably up to or potentially more than 8° from the vertical, while maintaining the center of gravity in moving mode CG 2 over the lifting region 70 . This allows the slurry apparatus 10 to be moved up or down a grade, and to tolerate variations of the ground surface. The hydraulic lifting platform 82 on the Lampson Crawler also has the ability to lift differentially, and thus compensate to some extent for the angle of a grade as shown in FIG. 16 . However, the slurry apparatus 10 itself may be tilted up to the point where the center of gravity CG 2 reaches the periphery of the lifting region 70 , beyond which the apparatus 10 will become unstable.
When the new site is reached the hydraulic jacks 29 are extended to support the frame on the crane mats 23 which have been placed on the ground beneath the first set of support points 21 , the hydraulic lifting platform 82 is lowered and the Lampson Crawler is driven away from the site. The slurry facility 10 is fully supported by the first set of spaced apart support points 21 , and can be returned to the operating mode by extending (from the previous site) and reconnecting the hydrotransport line and all electrical and water supplies. An ore feeder such as a transfer conveyor is positioned in communication with the comminuting apparatus 50 , and operation of the slurry facility 10 is resumed. When the slurry box 30 is once again filled with slurry, the center of gravity will shift from CG 2 back to CG 1 , shown in FIG. 14 .
In a further embodiment of the apparatus, the frame 20 is provided with pontoons 27 onto which the frame 20 is set instead of crane mats 23 . This reduces the steps required to both lift the slurry apparatus 10 and to prepare the new relocation site. This also has the advantage of adding weight to the bottom of the frame 20 , lowering the centres of gravity CG 1 and CG 2 . The operation of this embodiment is otherwise as previously described.
A suitable system, apparatus and process for extraction is described and claimed in Applicants' co-pending application Ser. No. 11/595,817, filed Nov. 9, 2006, entitled SYSTEM, APPARATUS AND PROCESS FOR EXTRACTION OF BITUMEN FROM OIL SANDS (published as U.S. Patent Application Publication No. 2007/0187321), claiming priority from Canadian Patent Application No. 2,526,336.
A preferred embodiment of the invention having been thus described by way of example only, it will be appreciated that variations and permutations may be made without departing from the invention, as set out in the appended claims. All such variations and permutations are intended to be included within the scope of the invention.
|
A relocatable oil sand slurry preparation system is provided for preparing an aqueous oil sand slurry amenable to pipeline conveyance while producing minimum overall rejects, comprising (a) a relocatable rotary digester for slurrying oil sand and water and digesting oil sand lumps to form a pumpable slurry, the rotary digester having a feed end for receiving oil sand and water, a slurrying chamber comprising a plurality of lifters for slurrying the oil sand and water, and a trommel screen end for screening out oversize rejects from the oil sand slurry which falls through the trommel screen; and (b) a relocatable rejects recirculation unit operably associated with the rotary digester for receiving oversize rejects and delivering the rejects back to the rotary digester for further digestion. In a preferred body, relocatable oil sand slurry preparation system further comprises a rejects crusher for crushing oversize rejects prior to delivering rejects back to the rotary digester.
| 4
|
RELATED APPLICATION DATA
[0001] This application is a continuation application of U.S. patent application Ser. No. 11/361,656, filed Feb. 23, 2006 entitled “Circuit Devices Which Include Light Emitting Diodes, Assemblies Which Include Such Circuit Devices, and Methods for Directly Replacing Fluorescent Tubes,” which is incorporated herein by reference in its entirety. This application claims the benefit and priority of U.S Provisional Application Ser. No. 60/657,100 filed Feb. 28, 2005 entitled “Fluorescent Replacement Using Light Emitting Diodes,” which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a circuit device for providing energy to a series of light emitting diodes and an assembly including such circuit devices and light emitting diodes. The present invention relates to a light emitting diode (LED) assembly for direct replacement of a tubular fluorescent light bulb.
BACKGROUND
[0003] The widespead use of fluorescent tubes for general purpose lighting has several drawbacks. One significant drawback is their use of rare-earth and other toxic phosphors to generate light. This provides a problem when tubes which have ceased to function require disposal. The phosphors can present a toxic waste situation which must be dealt with. Also, because the envelope of the tube is thin glass, the potential for accidental breakage, with attendant problems of scattering toxic material, is high. For this reason, in food-related and other industries where potential contamination is a risk, special plastic protective sleeves are required to be placed on all fluorescent tubes. A drawback to the use of these sleeves is that they trap heat generated by the tube and increase the operating temperature of the tube which decreases the useful life of the device.
[0004] The ballasts used in fluorescent fixtures present an inductive load to the line resulting in a lower than unity power factor. While fluorescent lighting is longer lasting and more efficient than incandescent bulbs, the tubes have a short life relative to solid state lighting devices. Based on an eight hour per day use, LED lighting will have an average usable life ten times that of a fluorescent light source.
[0005] With the introduction of high current, high output LEDs, the use of these devices in general purpose lighting has become feasible. One area of general lighting which could benefit from this technology is fluorescent lighting. Heretofore, tubes meant to accomplish this were unable to work with standard magnetic or electronic ballasts, and required replacement or complete rewiring of the lighting fixture.
SUMMARY OF THE DISCLOSURE
[0006] In one implementation, an LED lighting device for replacing a fluorescent tube in a fluorescent lighting fixture having fluorescent fixture connectors and one or more of a standard fluorescent ballast and a magnetic fluorescent ballast is provided. The LED lighting device includes a plurality of light emitting diodes; a pair of contact pins at each end of the lighting device, said contact pins configured for mating with the fluorescent fixture connectors of the fluorescent lighting fixture; and drive circuitry connected with said plurality of light emitting diodes and at least one contact pin of said pair of contact pins, said drive circuitry configured to provide an operating current to said plurality of light emitting diodes and to operate with a standard fluorescent ballast and a magnetic fluorescent ballast such that the lighting device is operable when connected to a fluorescent lighting fixture having a standard fluorescent ballast and operable when connected to a fluorescent lighting fixture having a magnetic fluorescent ballast.
[0007] In another implementation, an LED lighting device is provided. The LED lighting device includes a plurality of light emitting diodes; a pair of end caps, each of said pair of end caps disposed at an end of the lighting device; a male bi-pin fluorescent fixture connector disposed on each of said pair of end caps, each male bi-pin fluorescent fixture connector configured to mate with a fluorescent fixture connector of a fluorescent fixture having a standard electronic fluorescent ballast and to mate with a fluorescent fixture connector of a fluorescent fixture having a magnetic fluorescent ballast; and drive circuitry connected with at least one contact pin of said male bi-pin fluorescent fixture connectors and said plurality of light emitting diodes, said drive circuitry configured to provide an operating current to said plurality of light emitting diodes when said at least one contact pin is connected to a fluorescent fixture having a standard electronic fluorescent ballast and to provide an operating current to said plurality of light emitting diodes when said at least one contact pin is connected to a fluorescent fixture having a magnetic fluorescent ballast.
[0008] In yet another implementation, an LED lighting device is provided. The LED lighting device includes a pair of end caps, each of said pair of end caps disposed at an end of the lighting device; a housing extending between said pair of end caps; a plurality of light emitting diodes arranged in a single row between said pair of end caps, said housing comprising a plurality of fins extending radially outward from three sides of said plurality of light emitting diodes; a male bi-pin fluorescent fixture connector disposed on each of said pair of end caps, each male bi-pin fluorescent fixture connector configured to mate with a fluorescent fixture connector of a fluorescent fixture having a standard fluorescent ballast and to mate with a fluorescent fixture connector of a fluorescent fixture having a magnetic fluorescent ballast; and drive circuitry connected with at least one contact pin of said male bi-pin fluorescent fixture connectors and said plurality of light emitting diodes, said drive circuitry configured to provide an operating current to said plurality of light emitting diodes when said at least one contact pin is connected to a fluorescent fixture having a standard fluorescent ballast and to provide an operating current to said plurality of light emitting diodes when said at least one contact pin is connected to a fluorescent fixture having a magnetic fluorescent ballast.
[0009] In still another implementation, a circuit arrangement is provided. The circuit arrangement provides the proper drive to a multiplicity of LEDs, connected in a series string, by deriving the drive from standard magnetic or electronic ballast and commonly used fluorescent fixture wiring. Another circuit provides the capability of operation with any fixture wiring variation. Yet another circuit provides protection against the ballast generating a high “strike” voltage in the event that an LED fails open. Still another embodiment is shown which provides dimming capability for the light. Still yet another embodiment shows the interface circuitry for remotely dimming the LED light.
[0010] In yet still another implementation, no glass or other easily breakable materials are utilized and no toxic substances are used. Therefore, there is no need for heat trapping protective sleeves or other covering devices to be used. A further implementation provides for means to remove the heat generated by the LEDs and thereby increase the useful life of the devices. In still a further implementation, the filter capacitance at the input offsets, to some degree, the inductive load presented by the ballast and bring the input power factor closer to unity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For the purpose of illustrating the invention, the drawings show aspects of one or more embodiments of the invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:
[0012] FIG. 1 is a plan view of the final assembly of an embodiment of the invention.
[0013] FIG. 2 is a cross-sectional view of one end-cap of the assembly.
[0014] FIG. 3 is a cross-sectional view of the LED mounting and heat sink.
[0015] FIG. 4 is a schematic diagram of a basic embodiment of circuit elements and LEDs
[0016] FIG. 5 is a schematic diagram of an embodiment providing an arrangement of circuit elements to accommodate differing versions of fixture wiring.
[0017] FIG. 6 is a schematic diagram of a circuit which protects the circuit elements against damage from ballast-generated, high voltage “strike” voltages.
[0018] FIG. 7 is a schematic diagram of an embodiment providing dimming capability.
[0019] FIG. 8 is a schematic diagram of an embodiment providing interface circuitry for remote dimming of the device.
REFERENCE NUMERALS IN THE DRAWINGS
[0020] 10 Contact Pin
[0021] 20 End Cap
[0022] 30 Heat Sink
[0023] 40 Bridge Rectifier
[0024] 45 Bus Wire
[0025] 50 Input Capacitor
[0026] 55 Input Circuit Board
[0027] 60 LED
[0028] 70 LED Circuit Board
[0029] 90 Thermally Conductive Isolator
[0030] 100 Shut Down Triac
[0031] 110 Overvoltage Sense Zener Diode
[0032] 120 Current Setting Resistor
[0033] 125 Control Circuit Board
[0034] 130 NPN Power Transistor
[0035] 140 Base Drive Resistor
[0036] 150 Diode
[0037] 200 N Channel MOSFET
[0038] 210 P Channel MOSFET
[0039] 220 Microprocessor
[0040] 240 Voltage Regulator
[0041] 250 Input Zener Diode
[0042] 260 Filter Capacitor
[0043] 270 Capacitor
[0044] 280 Base Drive Resistor
[0045] 290 NPN Transistor
[0046] 300 Diode
[0047] 310 Resistor
[0048] 320 NPN Transistor
[0049] 330 Resistor
[0050] 340 Diode
[0051] 350 Resistor
[0052] 360 PNP Transistor
[0053] 370 Zener Diode
[0054] 380 Interface Device
DETAILED DESCRIPTION
[0055] Referring now to the drawings, FIG. 1 shows a plan view of an embodiment of the present invention. A multiplicity of LEDs 60 are mounted to the LED circuit board 70 and attached to two end caps 20 . This assembly is mounted to heat sink 30 which also acts as a protective housing. The end caps 20 are fitted with contact pins 10 , spaced such that they mate with standard fluorescent fixture connectors. The overall length of the assembly is equivalent to that of a standard fluorescent tube.
[0056] FIG. 2 is a cross-sectional of an end cap 20 . Contact pins 10 are physically and electrically connected to the input circuit board 55 upon which are mounted the rectifier bridge 40 and capacitor 50 . The input circuit board 55 is physically and electrically connected to the control circuit board 125 by bus wires 45 . The shut down triac 100 , overvoltage sense Zener diode 110 , and current setting resistor 120 are mounted on control circuit board 125 . These components are from the embodiment shown in FIG. 6 and are used for illustrative purposes only. As would be known to anyone skilled in the art, the components for any of the embodiments shown could be mounted to this board.
[0057] FIG. 3 is a cross sectional view of the LED mounting and heat sink. The LEDs 60 are mounted to LED circuit board 70 . This assembly is affixed to the heat sink 30 with thermally conductive isolator 90 such as T -Flex 210 , manufactured by Thermagon, or other such materials well known to anyone skilled in the art. Heat sink 30 consists of an aluminum extrusion coated with a material such as Powder Coat 10225 manufactured by The Eastman Company or other similar materials well known to anyone skilled in the art. This material, while being highly reflective to visible light has a high emissivity for infra-red. Conversely, the coating used on standard fluorescent fixtures, while being highly reflective to visible light, is an excellent absorber of infra-red. This combination permits heat sink 30 to effectively couple heat generated by the LEDs to the large area of the fluorescent fixture.
[0058] The operation of example LED drive circuits within the present invention will now be described in detail while referencing the embodiments of FIGS. 4 through 8 . All of the drive circuits presented herein make use of the constant current characteristic of standard and magnetic ballasts. By choosing LEDs which require a current of this magnitude, the need for additional constant current drive circuitry is eliminated.
[0059] FIG. 4 shows one type of drive for the LED string. A multiplicity of LEDs 60 is connected as a series string. The primary AC power is brought to the circuit by contact pins 10 . The input voltage is rectified by bridge rectifier 40 and filtered by capacitor 50 . The rectified, filtered voltage is then connected to the series string of LEDs 60 . The embodiment shown in FIG. 4 will operate with the most common wiring configuration of fluorescent fixtures. FIG. 5 shows the preferred embodiment for input power conditioning. A second bridge rectifier and filter capacitor are added to those shown in FIG. 4 . The embodiment of FIG. 5 allows the present invention to operate in any fluorescent fixture wired in accordance with prevailing electrical codes.
[0060] Should an LED in the series string fail as an open circuit, the ballast will sense that there is no current flowing and apply a high voltage “strike” voltage. This would normally cause the fluorescent tube to light. A “strike” voltage could cause serious damage to other components. To prevent this, the drive circuit shown in FIG. 6 is used. As shown, shut down triac 100 is connected across the power input to the LEDs 60 . If a “strike” voltage occurs, overvoltage sense Zener diode 110 conducts current. At a current set by current setting resistor 120 , a voltage sufficient to trigger shut down triac 100 into conduction will appear at its gate terminal. This shunts the voltage across the LED string and prevents possible catastrophic failure of other circuit elements.
[0061] FIG. 7 is the same embodiment shown in FIG. 4 with a dimming capability provided by the addition of an NPN transistor 130 , a base drive resistor 140 , and diode 150 . A pulse width modulated (PWM) signal is applied to the base of NPN transistor 130 through base drive resistor 140 . This causes NPN transistor 130 to shunt the drive current to LEDs 60 . By switching NPN transistor 130 on and off at a rate sufficiently high to prevent flicker, the apparent brightness of the LEDs 60 will vary as the on to off time ratio of NPN transistor 130 is varied. Diode 150 prevents NPN transistor 130 from discharging capacitor 50 .
[0062] FIG. 8 shows an embodiment which provides a remotely controlled dimming capability. The interface device 380 , which could be an infra-red, rf, or other type of receiver, sends command signals to microprocessor 220 . Operating voltage for microprocessor 220 and interface device 380 is provided by a low voltage regulator consisting of input Zener diode 250 , voltage regulator 240 , filter capacitor 260 , and capacitor 270 . The output of microprocessor 220 provides a drive signal to a level shifting and gate drive circuit consisting of resistors 280 , 310 , 330 , and 350 , NPN transistors 290 and 320 , PNP transistor 360 , P channel MOSFET 210 , diodes 300 and 340 , and Zener diode 370 . The gate drive signal is applied to N channel MOSFET 200 . By switching N channel MOSFET 200 on and off, in the same manner as recited above for NPN transistor 130 , the apparent brightness of LEDs 60 can be varied.
[0063] It will be apparent to anyone skilled in the art that the embodiment of FIG. 8 could be modified to control two strings of LEDs. By selecting warm white (low color temperature) for one string and cool white (high color temperature) for the other, that by varying the intensity of the strings with relation to each other, the resultant, effective color temperature could be controlled.
[0064] Although the description above contains specific heat sink, mounting, and assembly designs, these should not be construed as limiting the scope of the invention but as merely providing an illustration of the currently preferred embodiment.
[0065] Further, although various circuit configurations have been shown and described above there are numerous variations which can be used with the present invention, the specific design of which will be evident to one skilled in the art given the detailed description herein.
[0066] Thus, although the present invention has been described in relation to particular embodiments therof, many other variations and modifications will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
|
An arrangement of a multiplicity of LEDs, drive circuitry, and supporting structure to form a replacement for standard fluorescent tubes without the need to rewire or remove the magnetic or electronic ballasts in use in standard fluorescent fixtures.
| 5
|
BACKGROUND AND SUMMARY OF THE PRESENT INVENTION
This invention relates to a device for testing the hardness or rot depth of a power pole, for example a telephone pole, comprising a frame portion, a penetration portion located in or at the frame portion and intended, in response to an actuation force, to penetrate into the pole material, and members exposed to actuations, by which members the actuation force for the penetration portion is produced.
The new testing device is intended to be used for testing the rot depth and/or hardness in telephone poles or other corresponding power poles, such as power-line poles and the like. Such poles are made of wood and can be impregnated or unimpregnated. In the firstmentioned case salt-impregnated poles decaying from the outside are primarily of interest for the new device according to the invention.
The poles can have been sunk into the ground and are exposed to rotting in their buried portions, especially at the so-called earth band or at the pole portions located at the ground surface. As the poles much be climbed in connection with line work to be carried out high up on the poles, the rotting can involve risk of personal injuries. Regulations are, therefore, set up which prescribe the condition of the poles for being approved. This in its turn has given rise to the desire of being able to check in different connections the depth to which the rotting has proceeded.
The equipment, which heretofore has been used for testing rot depth or hardness, for example, of telephone poles have proved less practical. Test of a relatively great number of poles have been relatively complicated and expensive. For rendering the pole portions susceptible to rotting accessible, it was necessary to remove the soil and the possible wedging about each pole whereafter samples were taken in one or several points along the pole periphery and possibly in a vertical direction of the pole.
In accordance with the present invention, this is not necessary any longer. It is a characterizing feature of the invention, that a frame portion is provided with a part, which can be driven or sunk into the soil support adjacent the pole, and that the penetration portion, which has the shape of a pointed needle or the like, is placed in or at said part. The members for producing the actuation force, by which the penetration portion is controlled, are formed such that in the entirely or partially sunk state of said part, the members extend with their upper parts above the ground and from there it is possible by actuations to produce the actuation force. The invention also comprises the feature that the test device is provided with indicating means showing the degree of penetration of the penetration portion into the pole material when an actuation force of predetermined size is initiated above the ground.
In further embodiments, technical designs of different parts of the test device are proposed which increase the effect of the test tool, which is simple and economic to use in practice. The new test device is easy to handle and has a relatively light weight. The frame portion with associated measuring needle can be driven down, for example, by means of a sledge or some other corresponding tool and/or by mechanic beaters. When the pole is wedged by stones or the like, the frame portion can be driven down between the same.
BRIEF DESCRIPTION OF THE DRAWING
The invention is explained in the following by way of an embodiment described in the following and with reference to the accompanying drawings, in which
FIG. 1 is a schematic lateral view of the test device driven down adjacent and attached to a pole to be rot tested,
FIG. 2 is a view from above of the test device and pole according to FIG. 1,
FIG. 3a is a vertical view of the test device,
FIG.3b is a vertical view of the test device turned through 90° in relation to the view according to FIG. 3a,
FIG. 4 is a cross-sectional view of a rotary housing mechanism included in the test device,
FIG. 5 is a schematic view of a graduated disc and an indicating needle associated with the test device,
FIG. 6 is a schematic view of a test device according to the invention provided with a modified clamping means, which device is driven down adjacent and clamped on a pole,
FIG. 7 is a section along the line VII--VII in FIG. 6, and
FIG. 8 is a section along the line VIII--VIII in FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As mentioned above, the test device can be used for testing possible rot depth in the wood material of the pole or to test the hardness thereof. In principle, a test needle or similar penetration member is used for this purpose. By measuring the distance through which the test needle penetrates into the pole at a predetermined actuation force, the hardness of the pole wood can be determined. Rot softens the pole material, and the greater the penetration depth of the needle into the pole for a definite force, the greater the decay can be assumed to be, and vice versa. A pole 1, for example a telephone pole, (FIGS. 1 and 2) may have an outer diameter of, for example, 150-250 mm and normally tapers upward. The test device 2 is to be driven down to the side of and adjacent the pole, which at the embodiment shown is sunk into a soil base 3, which may be of any occurring condition, for example sand, earth, clay, till etc. The test device is provided downwardly with a bearing housing 4 for a test needle 5. The bearing housing comprises a bearing for longitudinal movement of the needle, so that the needle can be actuated between a fully retracted position and a fully extended position. The total extension movement A for the test needle may be about 40 mm. A rot depth extending this value may imply that the pole must be scrapped, because the rot depth normally can be assumed to extend uniformly about the periphery. Non-uniform attacks, however, can occur, and, therefore, sampling in several points along the pole periphery normally is prescribed.
The test device, thus, comprises a part 2a (FIG. 1) to be sunk or driven into the ground base. The total driving depth B or length of the part 2a can vary. For example that it may be desirable to make rot tests at 300 mm. Tests, however, can be carried out at other levels, both deeper and higher and also above the ground surface. The test device also is provided with a clamp yoke 6 and an associated clamp 7. By means of these retaining means 6,7 the test device is fixed on the pole so that the bearing housing firmly abuts the shell surface of the pole, before the test needle is actuated. Other types of retaining or fixing means can be imagined, for example, a chain, wire etc. with associated tightening screw.
In order to actuate the test needle from above the ground level 3, the test needle is actuated via a longitudinal movement mechanism by means of a turning rod, which is supported in a bearing pipe 8. The bearing pipe is attached on the upper surface of the bearing housing 4 and substantially is in parallel with the part 2a. The bearing pipe, besides, extends freely to the side of the part 2a and is not coupled together therewith, in order to prevent undue actuation from the strokes in connection with the driving-down of the part 2a.
The turning rod projects upward above the bearing pipe at the upper part thereof, where the turning rod is attached to a dynamometric wrench 9 of a kind known per se. The wrench is commercially available and operates with a moment size, which at the embodiment shown is about 40 Kpcm. An example of such a wrench is "Wernmeter" 7042B.
At the upper portions of the bearing pipe 9 a graduated disc 10 is attached, and to the turning rod a turning needle is attached which follows the movement of the turning rod. The disc is graduated to indicate the distance of the test needle movement, i.e. 0-40 mm in the present case. A force F1 is applied to the dynamometric wrench, and the moment for which disengagement takes place in the wrench, is set in relation to the actuation force for driving the test needle into the pole material. The test device is driven down into the ground base with the force F2.
The test device is shown in detail in FIGS. 3a and 3b. The frame portion 11 is made of steel. Downwardly the frame portion is integrated with the bearing housing 4. The frame portion 11 as well as the bearing housing have downwardly a wedge-shaped part 12, which facilitates the driving of the frame portion and bearing housing down into the ground base. The bearing housing has an oblong outer contour, which extends outwardly from the pole. At the lower end, the frame portion is provided with inclined members in the form of wings 13 and 14 so arranged, that the frame portion at its driving down adjacent the pole is forced to tightly abut the shell surface of the pole. The frame portion is upwardly provided with a stroke protection 15, which extends outward over the attachment of the dynamometric wrench. In this way, the wrench and the bearing pipe 8 and the turning rod mounted therein are not exposed to the driving strokes for the frame portion 1 in the event, that a stroke is misdirected. The stroke protection is made of impact resistant material, and the oblong frame (i.e. the test device in its entirety) may have a total length of about 500 mm.
The bearing pipe 8 is attached to the upper surface of the housing 4 by means of screws, by welding etc. The turning rod 16 is so mounted in the bearing pipe that it is rotatable by the dynamometric wrench and at the same time is fixed in its vertical position. The vertically fixed position is indicated by a transverse pin 17 where the turning rod projects out of the bearing pipe. The lower end surface 16a of the turning rod is supported in a cup in the bottom of the bearing housing. Bearing parts in the bearing pipe are designated by 8a and 8b. The transverse pin 17 co-operates with a lower surface on the bearing part 8b. The needle on the turning rod is designated by 18.
In the bearing housing 4 (FIG. 4) the test needle 5 is attached in a rack 19 movable in longitudinal direction. The test needle can be screwed into the rack end via threads 20, so that the test needle is exchangeable. The rack is mounted slidable in its longitudinal movement direction (in FIG. 4 from the right to the left, and vice versa) in a slide bearing 21, which may be designed in a manner known per se. The bearing 21 may have internal guide grooves, in which longitudinal shoulders on the rack are arranged. Teeth 19a on the rack 19 mesh with a gear wheel 22 attached to the turning rod 16. At the egress opening 4a of the bearing housing a wiper 23 of rubber, plastic or the like is located which prevents impurities from penetrating into the bearing housing when the test needle is retracted into the housing by the rack. The end part 4b is detachable, so that the wiper is exchangeable like the test needle.
As shown in FIG. 5, the disc 10 can be graduated in cm, for example between 0 and 4 cm. In the embodiment shown, the test needle is acute and owing to its point penetrates readily even into sound wood. When the needle thereafter penetrates in to a greater depth, the real resistance to the needle is obtained. In view thereof, the turning rod or indicating needle has a starting position 18a, which is located slightly before the O-position in order to compensate for the penetration of the point. In the position O the penetration proper commences. In the embodiment shown in FIG. 5 the test needle has penetrated in 1.2 cm for an actuation force F for the needle, which force is determined with the dynamometric wrench and with the transfer members formed by the turning rod 16, gear wheel 22 and rack 19, from which latter, thus, the actuation force F is obtained. The gear ratio on the transfer members as well as the size of the release moment in the wrench can be selected so that a suitable force F1 can be used on the wrench. During tests with the test device, the arm of the dynamometric wrench moves relatively uniformly and slowly so that variations in the penetration speed of the needle do not affect the result. The uniform and slow movement actuation must be tried out in every single case. The test device can be utilized for testing pole parts other than those located beneath the ground surface, in which case basically the same procedure is applied, except that the frame portion and bearing housing are not driven down into the ground base. The test needle 5 is made of a suitable metal, such as steel or the like.
With reference to FIGS. 6-8 a modified embodiment of the clamping means for the test device comprises a handle 25, which at one end is provided with a clamping leg 26 for engagement with the pole side remote from the frame 2a. The clamping leg 26 is clamped detachably in a partially open recess 27 at the end of a carrying arm 28. The arm 28 is attached to the frame 2a and has such a length, that the recess 27 is located to the side of the pole 1.
The recess 27 has a width corresponding to or slightly greater than the width of the handle with rectangular cross-section and is partially covered at one end by a flange 29 extending over the recess as shown in FIG. 8. The length of the recess should not exceed its width.
For attaching the clamping device, the handle 25 is inserted beneath the flange 29 of the recess and then turned down into the recess 27, whereafter the clamping leg 26 by help of the handle 25 is drawn against the pole 1 and at the same time the frame 2a is pressed inward against the same. Thereby the handle 25 is clamped in the recess 27 by the sides 30 thereof, owing to the clamping effect or so-called drawer effect. In order to increase the clamping force, i.e. the force, with which the clamping leg and bearing housing 4 are pressed against the pole 1, a tightening screw 31 is located at the upper frame portion. By tightening the screw 31, the upper portion of the frame is moved from the pole 1, and thereby the clamping leg 26 is clamped against one side of the pole at the same time as the bearing housing 4 is pressed against the opposite pole side, whereby the test device is retained safely. By pressing the bearing housing 4 against the pole, also the prerequisite condition for obtaining a correct measure of the rot depth and/or hardness is improved. The locking or clamping forces between the handle 25 and the sides 30 of the recess are also increased and result in a safe locking of the handle 25 in the recess 27.
In the embodiment shown in the drawing the handle 25 is straight and provided with graduation 32. In this way the clamping means 25,26 acts as a measuring callipers together with a pointer 33, which is located to the side of the recess 27 and in alignment with the side of the frame and/or bearing housing facing to the pole. When the test device has been clamped on a pole, the diameter of the pole can thus be read directly. By pressing the frame 2a from the pole by means of the tightening screw 31 in connection with the clamping of the test device, automatic compensation is made for the conical shape of the pole. The diameter measure, therefore, can be regarded to be the pole diameter at the test point. When higher accuracy is desired, the frame 2a can be provided with a level insensitive to impact or with a similar means, which directly indicates whether or not the frame inclines relative to the vertical plane.
According to the invention, the clamping leg 26 of the clamping means advantageously can be made of solid steel material or the like and can be formed with a pointed end 34 and a plane and 35 as shown in FIG. 7. The clamping means thereby also is a suitable tool in the form of a pick for removing possible wedge stones and earth prior to the driving of the test device down into the ground adjacent a pole. The clamping means also can be used for driving down the test device into the ground, when the end 35 is designed plane and a grip 36 is attached on the handle 25.
The present invention is not restricted to what is described above and shown in the drawings, but can be altered and modified in many different ways within the scope of the invention idea defined in the attached claims.
When the clamping means 25,26, for example, is designed also as a measuring callipers, the recess 27 suitably is placed substantially in parallel with the direction of test needle movement. Further, according to the invention the carrying arm 28 can be attached vertically movably on the frame 2a.
The principles, preferred embodiments and mode of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. The embodiments are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations and changes which fall within the spirit and scope of the present invention as defined in the claims be embraced thereby.
|
The invention relates to a test device, by means of which power poles are tested for hardness or rot depth. The device comprises a frame portion and a test needle or corresponding member located therein or thereto. The test needle is to be exposed to an actuation force so as to penetrate into the pole material. The degree of penetration for a definite actuation force is a measure of the hardness or rot depth. The test device further comprises means to be exposed to actuations, for example manual ones, by which means the actuation force to the penetration portion can be produced. The frame portion is provided with a part, which entirely or partially can be driven into the ground base adjacent the pole. The exposed means extend with upper portions above the ground surface in order to permit actuations to produce the actuation force. At the upper portions of the exposed means indicating means are located which indicate the degree of penetration for a definite size of the actuation force.
| 6
|
BACKGROUND OF THE INVENTION
The present invention relates generally to handling of hosiery during the manufacturing process, and more particularly, to an apparatus for straightening and stacking individual hose after they are turned and separated from the string.
During the manufacture of hosiery, particularly socks, it is common practice to knit the hosiery in a continuous, elongated tube divided by longitudinally-spaced, knitted rings of break-away thread. The first in-line hose is everted, or turned inside-out, and then broken away from the string by pulling. The hose is thus ready for closing the toe by the seamstress.
An apparatus for expediting the everting and separating steps is disclosed in U.S. Pat. Nos. 3,887,120 and copending application Ser. No. 527,441, filed Nov. 26, 1974, now U.S. Pat. No. 3,949,913 both assigned to the assignee of the present invention. In both U.S. Pat. Nos. 3,887,120 and 3,949,913, with a hollow tubular form located in a first working position, the hosiery string is loaded onto the form. An egress of air out the open end of the form assists in this operation by opening the string and reducing frictional resistance. The form is then pivoted to a second working position, wherein the first in-line hose on the string is everted into the open end of the form. An ingress of air at the open end of the form assists in that operation by drawing in the hose. Finally, the form is pivoted to a third working position to initiate a separating and stacking cycle of operation. A pair of fingers carried on a reciprocating arm come together and grasps the double-over end portion of the hose, and snaps it from the string at the ring of break-away threads. The arm then advances the hose along a predetermined path to a stacking region. Our U.S. Pat. No. 3,949,913 includes an improvement feature No., wherein the hosiery form is U-shaped to conserve floor space.
In the seaming operation that follows stacking, the operator ties a stack of about 24 hose, and transfers the stack to another station for sewing the toe. The seaming operation requires that the individual hose be stacked as evenly as possible. Thus, the operator must even up the individual hose before the stack is tied. Because the additional step of "evening up" must be performed, uneveness in the stack that results using prior apparatus substantially slows down the manufacturing operation.
OBJECTS OF THE INVENTION
It is thus an object of this invention to provide an improved apparatus for more efficiently manufacturing hosiery.
Another object is to provide an improved apparatus for stacking turned and separated hosiery during the manufacturing process.
A further object is to provide an improved apparatus that more evenly stacks individual hose that have been separated from a hosiery string.
A still further object of the invention is to provide an improved apparatus for straightening individual hose separated from a hosiery string, and then evenly stacking the hose in a tray for subsequent seaming.
Another object is to provide a stacking apparatus, wherein individual hose separated from a hosiery string are pulled along a platform for straightening before the hose are stacked.
It is another object of the invention to provide an improved apparatus for straightening and stacking hose separated from a hosiery string, wherein the hose are pulled along a platform for straightening before they are stacked, and wherein a guide member is provided to prevent the hose from laterally slipping off the platform.
Another object of this invention is to provide an improved apparatus for stacking hosiery, wherein a large number of hose are stacked.
BRIEF DESCRIPTION OF THE INVENTION
Briefly, in accordance with the invention, an apparatus for stacking hose separated from a hosiery string disposed on a tubular form comprises a pair of gripping fingers on a reciprocating arm for grasping and separating hose from the string by an initial pull, and then pulling the hose across a horizontal platform. During pulling, frictional resistance between the platform and hose causes the tail end of the hose to drag behind, and this tends to straighten the hose. After the hose has been advanced to a predetermined, fixed position on the platform, the fingers release and the platform is tilted to dump the hose into a tray located beneath the platform. The hose slides from the tilted platform along a beveled sidewall of the tray into a neat stack, ready for seaming.
The tubular form for storing the hosiery string is pivotable among first, second and third positions. In the first position, the hosiery is loaded onto the form, and an egress of air from the open end of the form is provided to open the string and reduce frictional resistance. In the second position, an ingress of air at the open end is provided to draw in the first in-line hose for eversion. Finally, in the third position, a separating and stacking cycle is initiated.
In the separating and stacking cycle, a reciprocating arm having a pair of fingers for gripping the hose is advanced from its rest position to the tubular form. The set of fingers grasps the doubled-over end portion of the first in-line hose at the mouth of the form. The arm then returns toward its rest position. As the initial return movement occurs, the hose is snapped from the hosiery string at the ring of break-away threads, and then the hose is dragged along the upper surface of the platform for straightening. The upper surface of the platform contains a layer of fabric material, such as denim, having a high coefficient of resistance with the hosiery. The added frictional resistance improves the straightening of the hose as it is pulled along the platform.
An upstanding guide member is attached to the side of the platform adjacent the hosiery form. The guide prevents the operator from laterally moving the hose off the platform by inadvertently returning the form back to its second position before the hose has been properly located on the platform.
The platform is mounted on a hinge for selectively positioning the platform (1) substantially horizontally for straightening the hose, and (2) inclined downwardly for dumping the hose into the tray. The platform is pivoted about the hinge with a pneumatic cylinder connected between the base of the apparatus and the platform. The cylinder is operated in response to the position of the tubular form; the platform is tilted downwardly as the advancing step is completed and the form is moved to the third position to initiate a new separating and stacking cycle.
Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by me of carrying out my invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of the invention, illustrating the platform and stacking tray, and with a hose located in position on the tray for stacking;
FIG. 1A is a more detailed view of the platform showing the operation of the upstanding guide member; and
FIG. 2 is a perspective view of the apparatus shown in FIG. 1, with the platform tilted downwardly for stacking hose.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 2 of the drawings, there is shown a preferred embodiment of an apparatus for separating, straightening, and stacking hose in accordance with the principles of the present invention. Specifically, the apparatus, generally designated by the reference numeral 10, includes a base 12 upon which are mounted a drive unit 14 for operating a reciprocating arm 16, and a tray 15. The arm 16 is movable within channel 18 between the opposite ends 20 and 22 of the drive member 14. Arm 16 contains a pair of fingers 24 that come together and close for gripping a folded over end of a hose H for initially pulling the hose from hosiery string S on tubular form 26, and secondly, advancing the hose along the upper surface of a horizontal platform 28 for straightening. The outermost gripping finger of the pair is formed by an elongated plate carried on the end of an actuating rod. A base plate is fixedly carried on the arm 16 and forms the other gripping finger. One end of the base plate slidably supports the actuating rod, which may be the armature of a solenoid (see FIGS. 1, 1a and 2). Platform 28 is pivotally mounted on a shaft 30 supported by members 31 (only one is shown), and is orientatable selectively in a substantially horizontal position (FIG. 1) and a downwardly tilted position (FIG. 2). As will be described in more detail below, a hose H, separated by being pulled initially from the hosiery string S, is advanced by arm 16 to a predetermined, fixed location on platform 28. The frictional resistance of "drag" between the hose and platform straightens the hose as it is advanced. Then, as the arm 16 disengages hose H and begins the return toward the form 26 for engaging another hose, platform 28 is tilted downwardly to the position shown in FIG. 2, dumping the hose into tray 15 (the angle of the downward tilt of platform 28 must, of course, be large enough to overcome the coefficient of static friction between the hose and platform). Since each of the hose is positioned at precisely the same location on platform 28 before dumping, the hose are neatly stacked in vertical alignment to each other in the tray 15.
Referring now to FIG. 1 in more detail, tubular form 26 is of a type disclosed in U.S. Pat. No. 3,949,913, supra. As described therein, the tubular form 26 is U-shaped, and extends outwardly from base 34, up and around toward platform 28, as shown. Hosiery string S, placed on the form 26, is a continuous tube of knitted material made up of a plurality of individual hose or socks connected together by rings of break-away thread such as alginate yarn.
Form 26 is manually movable to be positionable selectively in first, second and third positions (the first and third positions are shown respectively in FIGS. 1 and 2). The form is manually pivoted between the operative positions by the operator. In the first position (FIG. 1), form 26 is pivoted away from stop 36. In this position, the hosiery string S is manually loaded onto the form 26, while an egress of air is provided out the open end or mouth 38 of the form to help open the string and reduce frictional resistance, as described in U.S. patent 3,949,913. In the second position (intermediate the positions shown in FIGS. 1 and 2), ingress of air (suction) is provided in the open end 38 of the form 26 for eversion, or turning in, of the first in-line hose on the string S, also as described in U.S. Pat. No. 3,949,913 (see FIG. 3). The operator assists by manually advancing the string S toward the open end on the form 26 and folding and stopping the first in-line hose edge around the open end 38. The ingress of air draws the hose into open end 38 of the form 26 thereby everting or turning the hose. Finally, in the third position (FIG. 2), arm 16 is ready for a cycle of separating, straightening, and stacking the hose.
Movement of arm 16 is controlled by limit switches (not shown) responsive to the position of form 26. With form 26 located in its third position, as shown in FIG. 2, arm 16 is advanced by any suitable mechanism along channel 18 toward the tubular form 26 until fingers 24 engage the exposed rim of the first in-line hose on string S. As shown in FIG. 1, the hose is engaged along the welt between the fingers. It is clear that the outermost finger on the arm 16 enters the open end 38 of the form 26 with the other finger formed by the base plate remaining on the outside. The properly timed solenoid activation draws the fingers together grasping the hose. After fingers 24 have engaged the hose H, the direction of movement of arm 16 is automatically reversed. Hose H is thus snapped off string S by the initial pulling action and then pulled toward end 20 of drive unit 14 (see FIG. 1). As hose H is advanced along the upper surface of platform 28 toward end 20, frictional resistance between the hose and platform causes the tail end of the hose to drag behind, as shown. Frictional resistance between the hose H and platform 28 is enhanced by providing, on the platform 28, a layer of fabric material M, such as denim, having a high coefficient of resistance with respect to the hosiery material. The result is that the hose H is straightened for the subsequent seaming operation.
While pulling hose H, the arm 16 advances (see FIG. 2) to the end 20 of drive unit 14. Hose H is now positioned at a fixed location on platform 28, as shown in FIG. 2 (in dotted outlines).
During the next separating and stacking cycle, the arm 16 is moved toward end 22 at form 26 for grasping another hose from string S. The hose is grasped by the fingers 24 closing on the folded over portion of the next in-line hose H (this requires that the form 26 be manually indexed between the second and third positions). The hose is next pulled the length of the platform 28, which is at this point tilted downwardly (FIG. 2) by hydraulic cylinders 40 (only one of the cylinders is visible in the FIGURES) to transfer the hose H to the receiving receptacle. The cylinders 40 are connected between base 12 and each end of shaft 30 through links 42.
As aforementioned, form 26 containing the hosiery string S, is indexed between the second and third positions by the operator as he or she (by suction through open end 38 and manually) everts the first in-line hose (in the second position), and readies the drive unit 14 for cycling (in the third position). It sometimes occurs that the operator inadvertently moves form 26 from the third position back to the second position before arm 16 has reached end 20 of the drive unit 14. In order to prevent hose H from being moved laterally off platform 28, an upstanding guide member 44 is formed on platform 28. Guide member 44 is set off on an angle with respect to the platform, as shown, to retain the hose on the platform 28 without causing creasing.
Referring to FIG. 2, tray 15, located under the platform 28, contains an inclined side wall 46 adjacent platform 28. Side wall 46 is approximately in alignment with platform 28 in the downwardly tilted position to permit hose to slide down along the side wall for stacking. Also, since the stack of hose tends to lean against the inclined side wall 46, a large number of hose can be stacked in tray 15 without toppling over.
The specific mechanical apparatus by which the fingers 24 are operated whereby the hose is gripped, and the specific mechanical actuators for closing the fingers 24 and reciprocating the arm 16, does not form a part of the present invention, and, thus, has not been shown. Applicant hereby incorporates by reference the means shown in the two previous U.S. Pat. Nos. 3,887,120 and 3,949,913 that accomplish these movements. It is understood that this same means, or equivalent means, may be used in the present device without departure from the concept of the invention.
In this disclosure, there is shown and described only the preferred embodiment of the invention, but, as aforementioned, it is to be understood that the invention is capable of use in various other combinations and environments, and is capable of changes or modifications within the scope of the inventive concept as expressed herein.
|
In a hosiery handling apparatus wherein a string of hosiery is placed on a movable hollow tubular form, and everted through the open end of the form, a reciprocating arm grasps the first in-line hose and breaks it away from the string. The arm then pulls the hose across the top of a horizontal platform to a predetermined, fixed location on the platform. During the pulling operation, frictional resistance (drag) between the hose and platform tends to straighten the hose. An upstanding guide member, formed on the platform, prevents the hose from moving laterally off the platform. After the hose is located on the platform, the platform is tilted downwardly to dump the hose into a neat stack in a tray located beneath the platform. This readies the hose for a subsequent seaming operation.
| 3
|
BACKGROUND OF THE INVENTION
This invention relates to an improved yarn package carrier of the type used to support numerous packages of yarn in vertically-spaced relation on a plurality of upright spindles within a pressure kier. Pressure kiers typically have cylindrical side walls and a dome-shaped cover to seal closed the top opening. The kier must be able to withstand high internal pressures. As a result, the kier cover is dome-shaped to disperse the pressure within the kier more evenly and to more easily withstand the stress on its structural parts.
Pressure kiers are very commonly used to package dye yarns manufactured of various synthetic as well as natural fibers, and are almost indispensible in the dyeing of large, tightly wound packages of nylon and orlon, among others.
While dyeing with a combination of high pressure and heat is still the best means of applying a high quality dye to these types of yarns and fibers, the greatly increasing cost of energy and hydrocarbon-derived dyestuffs necessitates a more effective and efficient means of carrying out these processes. Even though the various dyeing equipment manufacturers can be expected eventually to develop new and much more efficient dyeing machinery, there exists a vast quantity and variety of older and relatively inefficient equipment in place which still has many years of useful life left but is becoming increasingly expensive to operate because of the greatly increasing cost of energy and dyestuffs.
It has been observed that all dome-covered pressure kiers, even those with very high pitched domes, are provided with yarn carriers, the spindles of which are all the same length and carry the same number of yarn packages. Invariably, these spindles extend to below or just even with the top opening of the kier. As a result, the area enclosed within the dome-shaped cover constitutes a large amount of essentially wasted space, since, while it must be filled with extremely hot water or air, it is not contributing to the productivity and efficiency of the kier. Furthermore, while it has not been heretofore recognized, it appears that the unoccupied space enclosed within the dome-shaped cover of a pressure kier contributes to poor quality dyeing by permitting foam to accumulate in the top of the kier, resulting in light or faded spots in the yarn packages carried near the top of the yarn carrier spindles.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide an improved yarn package carrier of the type used to support numerous packages of yarn in vertically-spaced relation on a plurality of upright spindles within a top opening, pressure dyeing apparatus such as a pressure kier.
It is a further object of this invention to provide an improved yarn package carrier with a greatly increased yarn package capacity, thereby enabling greatly increased efficiency in the consumption of energy and dyeing chemcials.
It is yet another object of this invention to provide an improved yarn package carrier which reduces the incidence of second-quality yarn by preventing the development and accumulation of foam in the dome-shaped cover of the pressure kier, thus avoiding light and faded spots on the upper yarn packages.
These and other objects and advantages of the present invention are achieved in the preferred embodiment set forth below by providing an improved yarn package carrier of the type used to support numerous packages of yarn in vertically-spaced relation on a plurality of upright spindles within a top opening, pressure dyeing apparatus having cylindrical side walls and a dome-shaped cover cooperating therewith to sealingly close the opening. The improved yarn package carrier comprises a circular base which is positioned within the dyeing apparatus adjacent its bottom. The carrier has an upper surface with a plurality of spindles mounted thereon perpendicular thereto. The spindles have progressively greater, pre-determined lengths so as to extend upwardly in tiers to a point above the top opening of the dyeing apparatus and into the area defined by and enclosed within the dome-shaped cover into close proximity thereto from its edge to its apex. As a result, the capacity of the dyeing apparatus is increased by enabling as many yarn packages to be carried by the spindles as can be mounted on each spindle intermediate the upper surface of the carrier base and the inner wall of the dome-shaped cover.
According to a preferred embodiment of the invention, a standard yarn carrier having 54 spindles, each spindle being 30.25 inches (76.8 cm.) in length and accommodating 8 packages, is modified by replacing these spindles with eighteen, 32-inch (81.2 cm.) and eighteen, 34-inch (86.4 cm.) spindles, each holding 9 yarn packages; twelve, 36-inch (91.4 cm.) spindles, each holding 10 yarn packages; and six, 37.5-inch (95 cm.) spindles, each holding 11 yarn packages. Therefore, a 54-spindle yarn carrier which previously held 432 yarn packages can now accommodate 510 packages within the same pressure kier. The improved yarn carrier, when loaded with yarn packages, gives a "wedding cake" effect. It is apparent when viewing the improved yarn carrier that the yarn packages extend upwardly towards the center of the yarn carrier and well into the area enclosed by the dome-shaped cover when in its closed position.
BRIEF DESCRIPTION OF THE DRAWINGS
Some of the objects and advantages of the invention have been set forth above. Other objects and advantages will appear as the description of the invention proceeds, when taken in conjunction with the following drawings, in which:
FIG. 1 is a schematic, top plan view of the spindle layout on the improved yarn carrier in accordance with a preferred embodiment of the invention;
FIG. 2 is a perspective view of the improved yarn carrier according to the present invention with most of the spindles removed for clarity in order to illustrate the progressive lengthening of the spindles towards the center of the yarn carrier; and,
FIG. 3 is a fragmentary, cross-sectional view of a conventional pressure kier in closed position, showing the improved yarn package carrier in accordance with the present invention positioned therein.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now specifically to the drawings, a pressure kier of a conventional type used in accordance with the present invention is illustrated in a simplified, representational form by broad reference numeral 10 in FIG. 3. The body of the kier is defined by cylindrical side walls 11, a bottom 12, and a circular top opening defined by the terminus of the cylindrical side walls 11.
A platform 13 is positioned concentrically in the bottom of the kier 10 as a support for the yarn carrier.
Still referring to FIG. 3, a dome-shaped cover 14 is shown in partial cross-section in close sealing engagement with the top opening of the kier 10. The cover 14 is hingedly secured to the kier 10 by hinge 15 and brace 16. A counterweight 17 is provided in order to provide a mechanical advantage in opening and closing the cover 14. An enlarged, downwardly facing U-shaped lip 19 is provided around the outer edge of the cover 14 for sealingly engaging the top opening of the kier 10 during the pressure dyeing cycle.
Positioned within the kier 10 is an improved yarn package carrier indicated at broad reference numeral 20. The carrier 20 is comprised of a circular base 21 having an upper, substantially planar surface 21a. The base includes a circular, concentric pedestal 22 on the bottom, downwardly facing surface of the base 21, as is shown in FIG. 3. The pedestal 22 provides a secure platform on which the base 21 can rest, and spaces the body of the base 21 a sufficiently great distance from the bottom 12 of the kier 10 so that free circulation of the dye liquor is facilitated.
The yarn carrier 20, especially when fully loaded with yarn packages, is extremely heavy. To facilitate movement of the yarn carrier 20 into and out of the kier 10, an elongate, upwardly extending handle 24 is securely fastened to the center of the yarn carrier base 21, as is shown in FIG. 2. Handle 24 is provided with a through slot 24a in the upwardly extending free end of the handle, through which a hook can be passed. Typically, the yarn carrier 10 is moved by means of an overhead electric hoist.
One of the problems encountered in the reduction to practice of the improved yarn package carrier 20 has been the wide variety of shapes and sizes of kiers presently being used. Even among kiers of the same general size, internal dimensions dimensions and proportions vary as does the degree of curvature of the dome-shaped cover. The specific preferred embodiment of the invention which is described herein involves the modification of a conventional yarn carrier having an outside diameter of 65 inches (165 cm.), and intended to fit within a Gaston County Dyeing Machine Company kier having an inside diameter of 67.25 inches (170.8 cm.), a pot depth of 32.5 inches (82.5 cm.) and a dome apex of 19 inches (48.3 cm.) from the cover lip.
While one specific preferred embodiment is disclosed herein, the invention is susceptible of application in any size or proportion of kier. Adaptation to other size kiers involves primarily a determination of the extent to which the spindles of the yarn carrier can be lengthened and/or repositioned to accommodate a greater number of yarn packages, while still permitting the cover of the kier to be closed and properly locked. As experimentation has shown, the modification described herein is most efficient when dyeing yarn packages called "muffs" or other packages having a relatively short height, since these packages provide smaller incremental increases in the distance required on each spindle to accommodate a given number of yarn packages. As FIG. 3 illustrates, a greater percentage of the space enclosed within the dome-shaped cover 14 of the kier 10 can be filled when dyeing packages having a relatively short height.
Referring to FIG. 1, a top plan view of the spindle layout on the improved yarn carrier is shown. In its conventional form with 54 spindles, each having a length of 30.25 inches (76.8 cm.) the carrier will accommodate eight one-pound "muffs" per spindle for a total of 432 "muffs" per carrier. On the 65-inch (165 cm.) carrier base described, the spindles have a lateral spacing of no less than seven inches (17.8 cm.).
In accordance with the present invention, each of the 54 spindles have been replaced with lengthened spindles as follows:
18 spindles, each 32 inches (81.2 cm.) in length (reference numeral 26)
18 spindles, each 34 inches (86.4 cm.) in length (reference numeral 27)
12 spindles, each 36 inches (91.4 cm.) in length (reference numeral 28)
6 spindles, each 37.5 inches (95 cm.) in length (reference numeral 29)
As is shown in FIG. 1, the eighteen outer spindles 26 are positioned in groups of three around the outer peripheral edge of the upper surface 21a of yarn carrier base 21. Spindles 27 are positioned around the upper surface 21a of the yarn carrier base 21 just inboard of the spindles 26. A space of approximately 2 inches (5.08 cm.) is allowed between the cover 14 and the top of the longest spindles 29.
Spindles 28 are likewise positioned in uniformly spaced-apart relation on the upper surface of yarn carrier base 21a just inboard of spindles 27. Finally, the six spindles 29 are positioned in uniform spaced relation immediately around the carrier handle 24.
As shown in FIG. 1, each of the four tiers of spindles (26, 27, 28, and 29) are arranged on the upper surface 21a of the yarn carrier 20 in the form of hexagons, as in many conventional kiers. Thus, only the length of the spindles, and not the spacing between spindles, has been modified in this embodiment of the invention.
The spindles in accordance with the above-described embodiment of this invention accommodate conventional one-pound yarn muffs as follows:
Spindles 26 and 27 (36 spindles total) each accommodate 9 yarn packages;
Spindles 28 (12 spindles total) each accommodate 10 spindles; and,
Spindles 29 (6 spindles total) each accommodate 11 yarn packages.
The number of different lengths selected for the various groups of spindles will vary greatly depending on kier size, the shape and curvature of the dome-shpaed cover, and many other variables. As noted above, the spindles in the preferred embodiment of the invention are four different lengths, notwithstanding the fact that only three different numbers of yarn packages (9 packages, 10 packages, and 11 packages) are placed on the spindles. However, with different size packages the difference in length can be important. Moreover, in accordance with the present invention the spindles should be extended to within approximately two inches of the cover 14, regardless of the particular size of the package which might be accommodated thereon. In individual instances where an additional package could be placed on each spindle with only a very slight increase in length, the spindles may be extended closer than two inches to the cover 14.
Thus, the yarn carrier 20, as modified, will now accommodate 510, one-pound yarn packages, whereas prior to the modification, it would accommodate only 432.
The stairstep, or tiered, configuration of the modified spindles is shown representationally in FIG. 2. A more complete view of the modified yarn carrier is shown in FIG. 3.
By increasing the yarn carrier capacity from 432 to 510 yarn packages, capacity of the kier is increased approximately 20% without the necessity of purchasing new equipment or carrying out any substantial and expensive modifications to the kier itself.
However, it has been learned that additional increases in capacity can be obtained by increasing the space between each spindle in order to accommodate larger packages. Of course, this means reducing the number of spindles on the yarn carrier. By increasing the length of the spindles in accordance with the present invention, increases in kier capacity of approximately 35% are possible. For example, the spacing between spindles on a conventional yarn carrier can be increased from 7 inches (17.8 cm.) to 8.5 inches (21.6 cm.). The number of spindles is thereby reduced from 54 to 41. With a spacing of 8.5 inches (21.6 cm.) between spindles, larger, 1.5 pound (0.68 Kg.) packages can be accommodated on the yarn carrier. The spindles, when arranged according to this modification, are spaced with 20 spindles around the periphery of the yarn carrier, 14 spindles immediately inboard of the 20 outer spindles and 7 spindles in closely circling relation to the handle of the yarn carrier. As in the preferred embodiment illustrated in the drawings, the outer 20 spindles each carry 9 yarn packages. The innermost 7 packages are lengthened to accommodate 11 yarn packages. The 14 intermediate spindles each carry 10 yarn packages, therefore, the 41 spindles, lengthened in accordance with this invention, will now accommodate 397 packages, each package weighing 1.5 pounds (0.68 Kg.). Therefore, the number of packages accommodated by the yarn carrier is increased from 328 to 397 by extending the spindles upwardly into the area enclosed by the dome-shaped cover of the kier.
The modifications described and/or illustrated above are sufficient to demonstrate the fundamental concept of this invention--that yarn capacity can be increased and dyeing quality improved without extensive modification by increasing the length of spindles within the kier to extend upwardly into the area enclosed by the dome-shaped cover and to therefore accommodate more yarn packages. Given the extremely wide variety of kier shapes and capacities, the exact length by which the spindles can be lengthened is a matter of measurement and calculation in each separate instance. As described above, the only modification usually required is to the length of the spindles on the yarn carrier 20. However, there may be instances in individual cases where a slight lowering of the platform on which the yarn carrier rests within the kier will enable some or all of the extended spindles to accommodate one additional yarn package each.
The greatest cost savings have been realized in the dyeing of stretch nylon, which requires expensive dye types and long dyeing cycles. For example, dyeing stretch nylon in a kier using a conventional yarn carrier costs approximately 0.696 dollars per pound (1.53 dollars per Kg.), whereas dyeing costs using a modified yarn carrier have extended spindles in accordance with the present invention, a cost per pound of 0.586 dollars (1.28 dollars per Kg.) was achieved for a savings of 11 cents per pound (0.24 dollars per Kg.). This saving is a result of a combination of factors. First, there is a direct saving in the quantity of dye used per pound of yarn. This results because the same amount of water and dye are used in both cases. Since the yarn carrier according to this invention carries more yarn, the cost of dye per pound of yarn dyed is reduced. Since the same amount of dye liquor is used to dye more yarn, a direct saving also results in that the amount of energy required to raise the quantity of dye liquor necessary to dye one package of yarn is reduced. As the cost of primary energy and petroleum-derived dyestuff increases, the savings realized for the above reasons can be expected to increase accordingly. By modifying yarn carriers in accordance with this invention, dyers will find it possible to attain substantial savings in dyeing costs without an offsetting expenditure for new equipment. Yarn carriers have been modified according to this invention at a cost of approximately $5.00 per spindle or approximately $270 per 54-spindle carrier. If spindles are also respaced from 7 to 8.5 inches in order to accommodate larger yarn packages, the cost of the modification per spindle is somewhat greater. In either case, the cost of these modifications, in view of the savings attained, is a very small fraction of the cost required to replace older, less efficient kiers with newer and more energy-efficient ones.
A completely unexpected result of the practice of this invention has been a substantial increase in yarn quality. Yarn spotting is and has been a chronic problem in pressure dyeing. Since the presence of light spots on yarn generally exhibits itself in packages positioned near the top of spindles on conventional yarn carriers, it was long ago understood that spotting was caused primarily by incomplete dyeing resulting from the accumulation of foam in the area of the kier enclosed by the cover, and hence having its greatest effect on yarn packages positioned uppermost in the kier.
Numerous solutions have been proposed for this problem. Wetting agents, anti-foaming agents, lengthened dyeing times, elevated dyeing temperatures, and "rest" periods during the dyeing cycle to enable the foam to dissipate have all been only partially successful, and in each case more expensive.
Dyeing yarn packages in accordance with the present invention has resulted in an almost complete elimination of yarn spotting. It is believed that this improvement in yarn quality results from extending the yarn carrier spindles upwardly into the area enclosed by the cover so that yarn packages accommodate this area during the dyeing cycle. With the elimination of the large open area within the kier cover, foam is no longer permitted to accumulate since its rapid circulation over the yarn packages within this area causes the foam to dissipate as quickly as it is generated. As a result of this phenomonen, dyeing cycles and temperatures can be reduced somewhat and anti-foaming agents can be eliminated.
Described above is a preferred embodiment of a modified yarn carrier which greatly reduces the cost of dyeing yarn packages, and, at the same time, greatly increases the quality of the yarn. Various details of the invention as described may be changed without departing from the scope of the invention. Furthermore, the foregoing description if for the purpose of illustration only and not for the purpose of limitation--the invention being defined by the claims.
|
An improved yarn package carrier for supporting packages of yarn in a pressure kier. The improved yarn package carrier comprises a circular base for being positioned within the kier adjacent its bottom and having an upper surface. The spindles are mounted on the upper surface of the yarn carrier base and have progressively greater pre-determined lengths so as to extend upwardly in tiers to a point above the top opening of the kier and into the area defined by and enclosed within the dome-shaped cover into close proximity thereto from its edge to its apex. As a result, the capacity of the kier is greatly increased by enabling as many yarn packages to be carried by the spindles as can be mounted on each spindle intermediate the upper surface of the carrier base and the inner wall of the dome-shaped cover.
| 3
|
FIELD OF THE INVENTION
The present invention relates to improved insulating and cushioning structures made from synthetic fibrous materials and more particularly to thermal insulating materials having the insulating performance, conformability and feel of down.
BACKGROUND OF THE INVENTION
A wide variety of natural and synthetic filling materials for thermal insulation applications, such as outerwear apparel, e.g. jackets, stocking caps, and gloves, sleeping bags and bedding articles, e.g., pillows, comforters, quilts, and bedspreads, are known.
Natural feather down has found wide acceptance for thermal insulation applications, primarily because of its outstanding weight efficiency, softness, and resiliency. Properly fluffed and contained within an article or garment, down is generally recognized as the insulation material of choice. However, down compacts and loses its insulating properties when it becomes wet and can exhibit a rather unpleasant odor when exposed to moisture. Also a carefully controlled cleaning and drying process is required to restore the fluffiness and resultant thermal insulating properties to an article in which the down has compacted.
There have been numerous attempts to prepare synthetic fiber-based structures having the characteristics and structure of down. Several attempts have been made to produce substitutes for down by converting the synthetic fibrous materials into insulating batts configured to have fibers that have specific orientations relative to the faces of the batt followed by bonding of the fibers to stabilize the web to afford improved insulating properties.
Such attempts include a pillow formed of an assemblage of generally co-planar fibers encased in a casing, where the fibers are substantially perpendicular to the major axis of the elliptical cross-section of the pillow surfaces to provide a degree of resiliency and fluffability; a thermal insulating material which is a web of blended microfibers with crimped bulking fibers which are randomly and thoroughly intermixed and intertangled with the microfibers to provide high thermal resistance per unit thickness and moderate weight; and a nonwoven thermal insulating batt of entangled staple fibers and bonding staple fibers which are substantially parallel to the faces of the web at the face portions of the web and substantially perpendicular to the faces of the batt in the central portion of the batt with the bonding staple fibers bonded to the structural staple fibers and other bonding staple fibers at points of contact.
Other structures include a blend of 80 to 90 weight percent of spun and drawn, crimped staple synthetic polymeric microfibers having a diameter of 3 to 12 microns and 5 to 20 weight percent of synthetic polymeric staple macrofibers having a diameter of from more than 12 up to 50 microns which is described as comparing favorably to down in thermal insulating properties and a synthetic fiber thermal insulating material in the form of a cohesive fiber structure of an assemblage of from 70 to 95 weight percent of synthetic polymeric microfibers having diameter of from 3 to 12 microns and from 5 to 30 weight percent of synthetic polymeric macrofibers having a diameter of 12 to 50 microns where at least some of the fibers are bonded at their contact points, the bonding being such that the density of the resultant structure is within the range of 3 to 16 kg/m 3 , the thermal insulating properties of the bonded assemblage being equal to or not substantially less than the thermal insulating properties of the unbonded assemblage. In this assemblage the entire assemblage is bonded together to maintain support and strength to the fine fibers without suffering from the lower thermal capacity of the macrofiber component.
A still further structure suggested for providing a resilient, thermally bonded non-woven fibrous batt includes having uniform compression modulus in one plane which is more than the compression modulus measured in a direction perpendicular to that plane and a substantially uniform density across its thickness. The batt is prepared by forming a batt comprising at least 20% by weight of crimped and/or crimpable conjugate fibers, i.e., bicomponent bonding fibers, having or capable of developing a crimp frequency of less than 10 crimps per extended cm, and a decitex in the range of 5 to 30. The batt is thermally bonded by subjecting it to an upward fluid flow heated to a temperature in excess of the softening component of the conjugate fiber to effect inter-fiber bonding.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a nonwoven thermal insulating batt having multiple layers of webs, each web comprising a blend of bonding staple fibers and staple fill fibers, the bonding fibers bonded to other bonding fibers and to said staple fill fibers at points of contact to enhance the structural stability of each of the layers of the batt. The batt may contain staple fill fibers of two or more deniers. Preferably, the batt is post treated, such as by surface bonding, to stabilize the layered structure.
The present invention also provides a method of making a thermal insulating nonwoven multilayer batt comprising the steps of:
(a) forming a web of bonding staple fibers and staple fill fibers;
(b) subjecting said web to sufficient heat to cause bonding of the bonding staple fibers to other bonding staple fibers and staple fill fibers at points of contact to stabilize the web, and
(c) forming a batt of multiple layers of said webs. Preferably, the web is formed by carding and the layering is achieved by cross-lapping the carded web. Further, the method preferably comprises post treating the batt, such as by surface bonding, to stabilize the layered structure.
The nonwoven thermal insulating batt of the present invention has thermal insulating properties, particularly thermal weight efficiencies, about comparable to or exceeding those of down, but without the moisture sensitivity of down. The presence of the individual layers of the multilayer batt increases the drapeability, softness of hand of the batt in conjunction with improved thermal insulating properties compared to batt compositions and constructions having single layer structures.
The mechanical properties of the batt of the present invention such as its density, resistance to compressive forces, loft as well as its thermal insulating properties can be varied over a significant range by changing the fiber denier, basis weight, structural to bonding fiber ratio, type of fibers, surface texture of the layer faces, and bonding conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a representation of the multilayer nonwoven thermal insulating batt of the present invention.
FIG. 2 is a cross-sectional view of a preferred embodiment of the multilayer nonwoven thermal insulating batt of the present invention..
DETAILED DESCRIPTION OF THE INVENTION
The present invention, as shown in FIG. 1 is a nonwoven thermal insulating batt 10 comprised of layers 11 which contain staple fill fibers 12 and staple bonding fibers 13. The bonding fibers bond to other bonding fibers and fill fibers at points of contact within each layer such that the layers maintain their integrity.
Staple fill fibers, usually single component in nature, which are useful in the present invention include, but are not limited to, polyethylene terephthalate, polyamide, wool, polyvinyl chloride, acrylic and polyolefin, e.g., polypropylene. Both crimped and uncrimped structural fibers are useful in preparing the batts of the present invention, although crimped fibers, preferably having 1 to 10 crimps/cm, more preferably having 3 to 5 crimps/cm, are preferred.
The length of the structural fibers suitable for use in the batts of the present invention is preferably from 15 mm to about 50 mm, more preferably from about 25 mm to 50 mm, although structural fibers as long as 150 mm can be used.
The diameter of the staple fill fibers may be varied over a broad range. However, such variations alter the physical and thermal properties of the stabilized batt. Generally, finer denier fibers increase the thermal insulating properties of the batt, while larger denier fibers decrease the thermal insulating properties of the batt. Useful fiber deniers for the structural fibers preferably range from about 0.2 to 15 denier, more preferably from about 0.5 to 5 denier, most preferably 0.5 to 3 denier, with blends or mixtures of fiber deniers often times being employed to obtain desired thermal and mechanical properties as well as excellent hand of the stabilized batt. Finer denier staple fibers of up to about 4 denier provide improved thermal resistance, drape, softness and hand which show more enhancement as the denier is reduced. Larger denier fibers of greater than about 4 denier provide the batt with greater strength, cushioning and resilience with greater enhancement of these properties with increasing fiber denier.
A variety of bonding fibers are suitable for use in stabilizing the layers of the batts of the present invention, including amorphous, meltable fibers, adhesive coated fibers which may be discontinuously coated, and bicomponent bonding fibers which have an adhesive component and a supporting component arranged in a coextensive side-by-side, concentric sheath-core, or elliptical sheath-core configuration along the length of the fiber With the adhesive component forming at least a portion of the outer surface of the fiber. The adhesive component of the bondable fibers is preferably thermally bonded. The adhesive component of thermally bonding fibers must be thermally activatable (i.e., meltable) at a temperature below the melt temperature of the staple fill fibers of the batt.
A range of bonding fiber sizes, e.g. from about 0.5 to 15 denier are useful in the present invention, but optimum thermal insulation properties are realized if the bonding fibers are less than about four denier and preferably less than about two denier in size. As with the staple fill fibers, smaller denier bonding fibers increase the thermal insulating properties, while larger denier bonding fibers decrease the thermal insulating properties of the batt. As with the staple fill fibers, a blend of bonding fibers of two or more denier can also be used.
The length of the bonding fibers is preferably about 15 mm to 75 mm, more preferably about 25 mm to 50 mm, although fibers as long as 150 mm are useful. Preferably, the bonding fibers are crimped, having 1 to 10 crimps/cm, more preferably having 3 to 5 crimps/cm. Of course, adhesive powders and sprays can also be used to bond the staple fill fibers, although difficulties in obtaining even distribution throughout the web reduces their desirability.
One particularly useful bonding fiber for stabilizing the batts of the present invention is a crimped sheath-core bonding fiber having a core of crystalline polyethylene terephthalate surrounded by a sheath of an adhesive polymer of an activated copolyolefin. The sheath is heat softenable at a temperature lower than the core material. Such fibers, available from Hoechst Celanese Corporation, are particularly useful in preparing the batts of the present invention and are described in U.S. Pat. Nos. 5,256,050 and 4,950,541. Other sheath/core adhesive fibers may be used to improve the properties of the present invention. Representative examples include fibers having a higher modulus core to improve the resilience of the batt or fibers having sheaths with better solvent tolerance to improve dry cleanability of the batts.
The amounts of staple fill fiber and bonding staple fiber in the batts of the present invention can vary over a wide range. Generally, the amount of staple bonding fiber in the batt can range widely. Preferably, the batt contains 5 to 100 weight percent staple bonding fiber and 0 to 95 weight percent staple fill fiber, more preferably 10 to 80 weight percent staple bonding fiber and 20 to 90 weight percent staple fill fibers, most preferably 20 to 50 weight percent staple bonding fiber and 50 to 80 weight percent staple fill fiber.
The nonwoven thermal insulating batts of the invention are capable of proving thermal weight efficiencies of preferably at least about 20 clo/kg/m 2 , more preferably at least 25 clo/kg/m 2 most preferably at least about 30 clo/kg/m 2 and radiation pammeters of less than about 20 (W/mK)(kg/m 3 )(100), more preferably less than about 15 (W/mK)(kg/m 3 )(100), more preferably less than 10 (W/mK)(kg/m 3 )(100).
The nonwoven batts of the present invention preferably have a bulk density of less than about 0.1 g/cm 3 , more preferably less than about 0.005 g/cm 3 , most preferably less than about 0.003 g/cm 3 . Effective thermal insulating properties are achievable with bulk densities as low as 0.001 g/cm 3 or less. To attain these bulk densities, the batts preferably have a thickness in the range of about 0.5 to 15 cm, more preferably 2 to 20 cm, most preferably 5 to 15 cm, and preferably have a basis weight from 20 to 600 g/m 2 , more preferably 80 to 400 g/m 2 , most preferably 100 to 300 g/m 2 .
The webs which comprise the layers of the batt of the invention can be prepared using any conventional web forming process including carding, garnetting, air laying such as by Rando-Webber™, etc. Carding is generally preferred. Each layer is preferably about 1 to 60 mm thick, more preferably 3 to 20 mm thick and preferably has a basis weight of about 5 to 300 g/m 2 , more preferably about 5 to 100 g/m 2 and most preferably 10 to 30 g/m 2 .
Thermal bonding may be carried out by any means which can achieve adequate bonding of the staple bonding fibers to provide adequate structural stability. Such means include, but are not limited to, conventional hot air ovens, microwave, or infrared energy sources.
The means of forming the layered batt is not critical. The layers may be formed by cross-lapping, layering multiple doffs, by ganging web formers or any other layering technique. The batts of the invention may contain up to about 100 layers, but generally contains about 5 to 30 layers and generally the effect can be seen with as few as two layers.
Preferably, the layered batt is post-treated to stabilize the layered structure. This can be done by heating the surface of the batt, such as by the use of conventional hot air ovens, microwave, or infrared energy sources to bond the perimeters of the layers on the periphery of the batt. This is shown in FIG. 2 where a batt 20 is seen in cross-section with layers 21 remaining individualized in the central portion of batt 20 and being bonded at the periphery 22.
In the Examples which follow, the following test methods were used.
Thickness
Thickness of each batt was determined by applying a 13.8 Pa (0.002 psi) force on the face utilizing a Low Pressure Thickness Gauge Model No. CS-49-46 available from Custom Scientific Instruments Inc.
Density
The volume of a sample of each batt was determined by fixing two planar sample dimensions and measuring the thickness as described above. The density was calculated by dividing the mass of each sample by the volume.
Thermal Resistance
Thermal resistance of the batts was determined according to ASTM-D-1518-85 to determine the combined heat loss due to convection, conduction and radiation mechanisms.
Hand
The hand of each batt was evaluated and ranked on a scale of ranging from poor, fair, good, to excellent.
The following examples further illustrate this invention, but the particular materials, and amounts thereof in these examples, as well as other conditions and details should not be construed to unduly limit this invention. In the examples, all parts and percentages are by weight unless otherwise specified.
Examples 1-6
In Example 1, staple fill fibers (75 weight percent Trevira™ Type 121 polyethylene terephthalate, 1.2 denier, 3.8 cm long, available from Hoechst Celanese Corp.) and bonding fibers (25 weight percent core/sheath fiber prepared according to U.S. Pat. Nos. 4,950,541 and 5,256,050, having a core of polyethylene terephthate surrounded by a sheath of an adhesive polymer of linear low density polyethylene graft copolymer, 2.2 denier, 2.5 cm long) were opened and mixed using a Cromtex™ opener, available from Hergeth Hollingsworth, Inc. The fibers were conveyed to a carding machine that utilized a single doffing roll and a single condensing roll such that the card provided a web having one side on which the fiber are oriented primarily in the machine direction to provide a substantially smooth surface while on the other surface the fibers are oriented in a more vertical direction to provide a loose fibrous character. The web was then passed through an air circulating oven at 218° C. at a rate of 1.68 meters per minute to achieve a stabilized web. The web was then cross-lapped conventionally to a 12-layer batt.
In Example 2, a batt was prepared as in Example 1 except the fiber content was staple fill fibers (55 weight percent Trevira™ Type 121 polyethylene terephthalate, 1.2 denier, 3.8 cm long, available from Hoechst Celanese Corp.) and staple bonding fibers (45 weight percent of the core/sheath fiber used in Example 1).
In Example 3, a batt was prepared as in Example 1 except the fiber content was staple fill fibers (25 weight percent Trevira™ Type 121 polyethylene terephthalate, 1.2 denier, 3.8 cm long, available from Hoechst Celanese Corp.) and staple bonding fibers (75 weight percent of the core/sheath fiber used in Example 1) and the web was crosslapped to form a 12 layer batt.
In Example 4, a batt was prepared as in Example 1 except the fiber content was staple fill fibers (55 weight percent Trevira™ Type 121 polyethylene terephthalate, 1.2 denier, 3.8 cm long, available from Hoechst Celanese Corp.) and staple bonding fibers (45 weight percent of the core/sheath fiber used in Example 1) and the web was crosslapped to form a 5 layer batt.
In Example 5, a batt was prepared as in Example 1 except the fiber content was staple fill fibers (55 weight percent Trevira™ Type 121 polyethylene terephthalate, 1.2 denier, 3.8 cm long, available from Hoechst Celanese Corp.) and staple bonding fibers (45 weight percent of the core/sheath fiber used in Example 1) and the web was crosslapped to form a 20 layer batt.
In Example 6, a batt was prepared as in Example 1 except the fiber content was staple fill fibers (55 weight percent Fortrel™ Type 69460 polyethylene terephthalate, 0.5 denier, 3.8 cm long, available from Wellman Fiber Industries, Florence, S.C.) and staple bonding fibers (45 weight percent of the core/sheath fiber used in Example 1).
In Example 7, a batt was prepared as in Example 1 except the fiber content was staple fill fibers (55 weight percent Trevira™ Type 121 polyethylene terephthalate, 0.85 denier, 3.8 cm long, available from Hoechst Celanese Corp.) and staple bonding fibers (45 weight percent of the core/sheath fiber used in Example 1).
Samples were tested for basis weight, bulk density, thickness, thermal resistance, thermal weight efficiency and hand. The test results are set forth in Table I.
TABLE I__________________________________________________________________________Example 1 2 3 4 5 6 7__________________________________________________________________________Fill Fiber 75 55 25 55 55 55 55(%)Bonding 25 45 75 45 45 45 45Fiber (%)Basis 233 240 255 101 383 221 250Weight(g/m.sup.2)Thickness 10.6 9.5 9.8 3.7 14.4 8.2 14.9(cm)Bulk 2.2 2.5 2.6 2.7 2.7 2.8 1.7Density(kg/m.sup.3)Thermal 7.4 7.0 6.9 3.1 10.4 7.6 8.8Resistance(clo)Thermal 31.8 29.2 23.6 30.3 27.2 30.4 35.2WeightEfficiency(clo/kg/m.sup.2)Hand Excel. Excel. Excel. Excel. Excel. Excel. Excel.__________________________________________________________________________
As can be seen from the data in Table I, in Examples 1, 2 and 3 changing the amount of bonding fiber does not substantially affect the thickness, density or hand, but increasing the amount of the larger denier fill fiber decreases the thermal resistance and the thermal weight efficiency. At higher weights, thickness and thermal resistance increased, the density remained substantially the same and thermal weight efficiency decreased. The substantially constant density demonstrates that the bonding of the webs before layering holds the webs intact in the layers so that the weight of the layers does not compress the batt.
Examples 8-10
In Examples 8-10, batts were prepared as in Example 1 except using staple fill fibers (Trevira™ Type 121 polyethylene terephthalate, 1.2 denier, 3.8 cm long, available from Hoechst Celanese Corp.) and staple bonding fibers (the core/sheath fiber used in Example 1) in the amounts shown in Table II with each batt formed by crosslapping 12 web layers and subsequent to crosslapping the batt was surface bonded with infrared irradiation at 163° C. for 36 minutes. The batts were tested as in examples 1-7. The results are reported in Table II.
TABLE II______________________________________Example 8 9 10______________________________________Fill Fiber 75 55 25(%)Bonding 25 45 75Fiber (%)Basis 215 286 277Weight(g/m.sup.2)Thickness 6.5 7.6 7.1(cm)Bulk 3.3 3.8 3.9Density(kg/m.sup.3)Thermal 5.8 6.7 6.7Resistance(clo)Thermal 26.7 23.5 24.3WeightEfficiency(clo/kg/m.sup.2)Hand Excellent Excellent Excellent______________________________________
As can be seen from the data in Table II, surface bonding of the batts did also produced batts having excellent thermal resistance and thermal weight efficiency, although varying the amounts of the finer denier fill fibers did not appreciably affect these properties.
Comparative Examples C1-C6
In Comparative Example C1, a batt was prepared as in Example 2 except the web was not bonded prior to cross lapping. In Comparative Examples C2-C6, various commercially available thermal insulating materials were evaluated using the test methods used in Examples 1-6. The materials were as follows: Goose Down 600 available from Company Store, Lacrosse, Wis. (Comparative Example C2); Primaloft™, available from Albany International Corp., Albany, N.Y. (Comparative Example C3); Comforel™, available from DuPont Co., Wilmington, Del. (Comparative Example C4); Kod-O-Fil™, available from Eastman Chemical Co., San Mateo, Calif. (Comparative Example C5); and Thermoloft™, available from DuPont, Inc. (Comparative Example C6). Test results are set forth in Table III.
TABLE III______________________________________Example C1 C2 C3 C4 C5 C6______________________________________Fill Fiber 55 -- -- -- -- --(%)Bonding 45 -- -- -- -- --Fiber (%)Basis 259 237 308 278 146 324Weight(g/m.sup.2)Thickness 6.6 6.0 3.9 3.9 2.2 3.7(cm)Bulk 3.9 4.0 7.8 7.2 6.6 8.8Density(kg/m.sup.3)Thermal 5.8 7.4 5.3 5.5 2.3 4.4Resistance(clo)Thermal 22.2 31.1 17.3 19.8 15.8 13.4WeightEfficiency(clo/kg/m.sup.2)DrapeHand Good Excel- Good Good Poor Fair lent______________________________________
As can be seen from the data in Table III, the unbonded batt of Comparative Example C1 had lower thermal resistance and thermal weight efficiency and poorer hand than the similar batt of Example 2. The down sample of Comparative Example C2, had excellent thermal resistance, thermal weight efficiency and hand although it would be expected to exhibit an unpleasant odor when wet typical of down. Comparative Examples C3-C6 exhibited poorer thermal weight efficiency and hand than the down sample or the batts of the invention.
|
A multilayer nonwoven thermal insulating batt is provided. The batt comprises multiple layers of webs, each web being a blend of 5 to 100 weight percent bonding staple fibers and 0 to 95 weight percent staple fill fibers, the bonding fibers bonded to other bonding fibers and fill fibers at the points of contact to enhance the structural stability of the layers of the batt. Also provided is a method of making the thermal insulating nonwoven multilayer batt comprising the steps of: (a) forming a web of bonding staple fibers and staple fill fibers; (b) subjecting the web to sufficient heat to cause bonding of the bonding staple fibers to other bonding staple fibers and staple fill fibers at points of contact within the web to stabilize the web; and (c) forming a batt of multiple layers of said webs.
| 3
|
BACKGROUND OF THE INVENTION
This invention relates to amplifiers, more particularly to CMOS class AB amplifiers having low quiescent current and improved phase response.
It is desirable to have amplifiers capable of sourcing and sinking relatively high output currents while still having well-controlled low quiescent currents in the output stage and associated driving stages to conserve power. Such amplifiers are particularly necessary in battery-operated apparatus, for example, portable telephones. Class AB amplifiers typically used in such applications, but circuits for driving the output stages in such amplifiers have tended to be complex and to have disadvantages, such as consuming too much current and posing problems in achieving good phase margins for high frequency designs. It is also desirable to have such amplifiers that will operate properly despite fluctuations in power supply or battery voltage and variations in component characteristics from chip to chip.
It class AB amplifiers it is necessary to drive two output devices connected in a push-pull circuit with the same input signal. In a CMOS circuit, such output devices are typically complementary field-effect transistors (FETS). The input signal is applied to both output devices with a different quiesent or bias voltage for each device, thus requiring a level shift. Examples of prior art class AB amplifiers are shown in U.S. Pat. No. 4,800,339 issued Jan. 24, 1989. One such example includes a reference voltage generator, a subtractor, a voltage-to-current converter and a current-to-voltage converter to perform such level shift.
It is an object of this invention to provide an improved class AB CMOS amplifier having low quiescent current, good phase response and high-frequency capability and insensitivity to variations in FET characteristics from chip to chip and to fluctuations in power supply or battery voltage.
SUMMARY OF THE INVENTION
The class AB CMOS amplifier of my invention includes a conventional push-pull stage having two complementary common-source outputs FETs in series. The input signal is connected directly to the gate of one of the output FETs and through a level-shifting stage to the gate of the second output FET. The level-shifting stage includes a first FET operating as a source-follower, a current-control FET and a load FET, all connected in series. The input signal is connected to the gate of the source-follower FET, a reference voltage is connected to the gate of the current-control FET and the voltage across the load FET is applied to the gate of the second output FET. The magnitude of the reference voltage determines the magnitude of the quiescent current in the level-shifting stage and thereby the quiescent current in the second output FET. The circuit configuration permits the impedance levels in the level-shifting stage to be relatively low, thereby avoiding phase margin problems while still maintaining low quiescent currents. The FETs in the circuit are sized in pairs, with size ratios chosen to establish the gain of the circuit and desired relationships among quiescent currents, regardless of power-supply fluctuations and variations in FET characteristics from chip to chip.
In an alternative embodiment, an additional FET is connected to cause the input signal to vary the reference voltage, essentially doubling the drive to the second output FET.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a circuit diagram of a prior-art class AB CMOS amplifier useful in pointing out the advantages of my invention.
FIG. 2 is a circuit diagram of class AB amplifier constructed in accordance with my invention.
FIG. 3 is a circuit diagram of an alternative embodiment of the amplifier of FIG. 2.
DETAILED DESCRIPTION
The prior-art circuit of FIG. 1 is substantially that disclosed in U.S. Pat. No. 4,800,339 referred to above. Referring to FIG. 1, an input signal referenced to V dd is provided on lead 10 by input amplifier 11 and connected to the gates of field-effect transistors (FETs) Q3 and Q7. The output of amplifier 11 is biased so that when no signal is present, the quiescent voltage on lead 10 is more negative than V dd by somewhat more than the threshold voltage of an FET (about 1.25 volts), thus allowing a small quiescent current to flow in FET Q7.
Diode-connected FETs Q1 and Q2 and current source 12 form a voltage reference circuit that provides a constant-voltage output (with respect to V dd ) at node 13. Such constant-voltage output is substantially the sum of the threshold voltages of FETs Q1 and Q2 (about 2.5 volts). FET Q3 is a common-source amplifier with FET Q4 as a load. The current from source 12 and the sizes of the FETs are chosen so that the voltage gain of Q3 is -1 and the quiescent voltage at node 14 is the same as that on lead 10. The stage comprising FETs Q3 and Q4 is said to be a subtractor because the resulting signal at node 14 is the input signal subtracted from the reference voltage. FET Q5 converts voltage variations to node 14 into current variations in lead 15 and FET Q6 converts such current variations back into voltage variations at node 16. FETs Q5 and Q6 are sized to give a gain of -1, so the signal at node 16 is the same amplitude as and in phase with the signal on lead 10, but shifted so that the quiescent voltage at node 16 is more positive than V ss by about the threshold voltage of an FET, thus allowing the quiescent current flowing in FET Q8 to be substantially equal to that flowing in FET Q7. FETs Q7 and Q8 are connected as a conventional push-pull output stage. Series circuit 17 comprising a capacitor and a resistor is a phase compensation circuit for stabilizing operation of the amplifier when negative feedback is introduced between output terminal 18 and input amplifier 11. In accordance with class AB operation, as is well known, a positive-going signal on lead 10 will cause FET Q7 to be cut off and FET Q8 to conduct, whereas a negative-going signal on lead 10 will cause FET Q7 to conduct and FET Q8 to be cut off.
FIG. 2 is a circuit of a class AB CMOS amplifier configured in accordance with my invention. Referring now to FIG. 2, input amplifier 20 provides an input signal referenced to V dd on lead 21, which is connected directly to the gate of output FET 50. Input amplifier 20 can be a differential voltage amplifier or any other source capable of providing the necessary signal magnitude at the required bias level. Again, the output of amplifier 20 is biased so that the quiescent voltage on lead 21 is more negative than V dd by about the threshold voltage of an FET, thus allowing a small quiescent current to flow in FET 50.
Diode-connected FETs 31, 32 and 33 and current source 34 form a reference voltage generator that provides a constant voltage (with respect to V dd )at node 35. By sizing the various FETs with respect to each other as will be described below, the magnitude of the reference voltage at node 35 becomes such that a small quiescent current, for example, about 25 microamperes, flows in the level-shifting stage comprising FETs 41, 42 and 43.
In the level-shifting stage, FET 41 is connected as a source-follower. FET 42 controls the quiescent current in the level-shifting stage in accordance with the magnitude of the reference voltage at node 35. The voltage across load FET 43 is connected to the gate of FET 51 at node 44. With no signal present, the voltage at node 44 will be more positive than V ss by about the threshold voltage of an FET, allowing the quiescent current flowing in FET 50 to also flow in FET 51. The signal at node 44 is in phase with the signal on lead 21 and FETs 41, 42 and 43 are sized so that the magnitudes of such signals are approximately equal.
FETs 50 and 51 are also connected as a conventional push-pull output stage. Series circuit 54 is a phase compensation circuit as described in conjunction with FIG. 1. Again in accordance with class AB operation, a positive-going signal on lead 21 will cause FET 50 to be cut off and FET 51 to conduct, whereas a negative-going signal on lead 21 will cause FET 50 to conduct and FET 51 to be cut off.
The various FETs in the circuit of FIG. 2 are sized by setting the dimensions of certain pairs of FETS of the same polarity type to be in accordance with certain ratios. For such sizing purposes, FET 31 is paired with FET 50, FET 33 with FET 42, FET 32 with FET 41 and FET 43 with FET 51. One possible set of ratios is for FET 32 to be equal in size to FET 41, FET 33 to be equal in size to FET 42, FET 50 to be N times larger than FET 31 and FET 51 to be N times larger than FET 43. Such ratios between FET 32 and FET 41 and between FET 33 and FET 42 cause the quiescent current in lead 45 to be essentially equal to the quiescent current I in lead 36, the magnitude of which is controlled by current source 34. The ratio N between FET 50 and FET 31 and between FET 51 and FET 43 causes the quiescent current through both FETs 50 and 51 to be substantially equal to N times I. A typical value for N is 10. As is well known in the art, circuit relationships established by size ratios as described above tend to be independent of variations in FET characteristics from one integated circuit chip to another and from fluctuations in power-supply voltages.
Some of the properties of the class AB amplifier circuit configured as shown in FIG. 2 in accordance with my invention are also present in the prior art circuit of FIG. 1. However, the circuit of FIG. 2 has some clear advantages. First, the circuit of FIG. 2 contains only three branches instead of the four in the circuit of FIG. 1. Thus, the circuit of FIG. 2 can have significantly lower quiescent current. Another important, but less clearly evident, advantage relates to phase-related instabilities, as will now be described.
Design considerations, such as bias requirements and efficiency goals, typically result in the optimum magnitude of the signal at node 14 in the circuit of FIG. 1 and on lead 45 (and at node 44) in the circuit of FIG. 2 being approximately ±0.5 volt around the quiescent voltage. In the circuit of FIG. 1, such a voltage swing would necessitate biasing FETs Q3 and Q4 at least 0.5 volts above their threshold voltages. If it is also desired to keep the quiescent current through FETs Q3 and Q4 low, say about 25 microamperes, then FETs Q3 and Q4 would need to be designed with low width-to-length ratios, resulting in relatively high-impedance devices. This results in high impedance at node 14(determined primarily by the impedance of FET Q4), which becomes even higher during large positive swings of node 10 (negative swings of node 14) as the current through FETs Q3 and Q4 decreases and FET Q4 nears cutoff. Such high impedance can create a strong nondominant pole at a relatively low frequency, giving rise to poor phase margins and thus limiting the useful frequency range of such circuits.
In contrast, the circuit of FIG. 2 can be realized with relatively low-impedance FETs. FETs 41 and 42 can be biased at about 100 millivolts above their threshold voltages under quiescent conditions. For the same quiescent current of 25 microamperes, FETs 41 and 42 can have a relatively high width-to-length ratio, resulting in lower impedances and causing the non-dominant pole to occur at relatively higher frequencies. Furthermore, as the current through FETs 41 and 42 increases during large signal excursions, such impedances decrease, pushing the non-dominant pole to even higher frequencies. Thus, the circuit of FIG. 2 demonstrates superior phase response to that of the circuit of FIG. 1 and similar prior-art circuits.
In the circuit of FIG. 2, the quiescent voltage on lead 21 is typically about 1.25 volts more negative than V dd . If amplifier 20 is powered from V dd , the highest positive voltage excursion on lead 21 is typically about 0.75 volts more negative than V dd because of the limitations of circuits of the type that would typically be used for amplifier 20. This limits the voltage swing possible on the gate of FET 51 and thus the current-sinking capabilities of FET 51. This problem is alleviated by the improvement shown in the circuit of FIG. 3.
The circuit of FIG. 3 is identical to that of FIG. 2 with the addition of additional FET 60, which has its source and drain connected in parallel with FET 31 and its gate connected to lead 21. In operation, as the input signal on lead 21 causes the voltage on lead 21 to become more positive, nodes 61 and 35 become more negative by about the same amount. The gate of FET 42 thus becomes more negative by about the same amount that the gate of FET 41 becomes positive, thereby increasing the voltage swing at node 44 and increasing the current-sinking ability of FET 51.
It would also be readily apparent to one skilled in the art how to modify the circuits of FIG. 2 and FIG. 3 for an input signal referenced to V ss instead of V dd , for example, by inverting such circuits and reversing the FET polarity types.
It is understood that other embodiments are possible that incorporate the principles of my invention and that the above disclosure is merely illustrative of such principles and is not intended to be limiting in any respect.
|
A class AB CMOS amplifier stage is disclosed having well-controlled low quiescent current and good phase stability. A first FET in a complementary push-pull output stage is driven directly by an input signal biased so that such FET conducts a small quiescent current. The second FET in the output stage is driven through a level shifting circuit. The quiescent current in the level-shifting circuit is controlled by a reference voltage. The FETs in the output stage, the level-shifting circuit and the reference-voltage generator are sized with respect to each other to determine the relative magnitudes of quiescent currents and the overall gain of the circuit. The operation of the circuit is essentially independent of process-induced variables and power-supply fluctuations. The FETs in the level-shifting stage can have relatively low impedances for good phase response property.
| 7
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from and the benefit of PCT Application No. PCT/EP2008/004994, filed on Jun. 20, 2008; German Patent No. DE 10 2007 033 776.2, filed on Jul. 18, 2007; German Patent DE 10 2007 033 780.0, filed on Jul. 18, 2007; German Patent No. DE 10 2007 777.0, filed on Jul. 18, 2007; and German Patent No. DE 10 2007 033 783.5, filed on Jul. 18, 2007; all entitled “Structure for a Vehicle Seat”, which are herein incorporated by reference.
BACKGROUND
The invention relates to a structure for a vehicle seat, which structure comprises rigid structure components which form cavities and comprises a foam structure which at least partially fills the cavities.
Such vehicle seats are generally known. For example, the German laid-open specification DE 102 14 476 A1 and the German laid-open specification DE 103 21 289 A1 respectively disclose a frame composed of hollow profiles and a backrest of a vehicle seat, with a foam being arranged in each case in cavities of structural elements. Furthermore, the German laid-open specification DE 10 2004 043 860 A1 and the German laid-open specification DE 197 46 164 A1 respectively disclose a backrest for a seat and a material combination having a profile which is hollow at least in sections, with a foam being arranged in cavities of structural elements. Furthermore, the German laid-open specification DE 42 08 150 A1 and the German laid-open specification DE 197 27 907 A1 respectively disclose a backrest for a vehicle seat and a method for filling cavities in workpieces or semi-finished parts. Furthermore, the German patent document DE 40 28 895 C1 and the European patent application EP 1 591 224 A1 respectively disclose a foam body for partitioning body cavities and a device and method for noise damping in cavities of vehicles. Furthermore, the patent DE 10 2006 014 538 B3 discloses the arrangement of a cable in the interior of a tube on a motor vehicle seat, and an elastic body for a line bushing is known from document DE 198 17279 A1. Furthermore, document DE 36 36 113 A1 discloses a method for forming a foamed mass in a cavity, DE patent 23 03 289 discloses a vehicle seat having a shell which supports a seat back pad, and document DE 37 14 588 A1 discloses a safety seat back beam composed of plastic.
It is disadvantageous in the known vehicle seats that, in part, the cavity is always completely filled or else only a partial filling of the cavity is aimed merely at improving the acoustic properties.
SUMMARY
The object of the present invention is therefore the targeted formation or introduction of a filling in or into a cavity of a structural element of a vehicle seat in order to improve the mechanical properties of the vehicle seat.
The object is achieved by means of a vehicle seat having a backrest and having a seat part, with the backrest or the seat part having at least one structural element which has a cavity, with at least one part of the cavity having provided in it a filling which is introduced to influence the stability and/or the deformation behavior of the backrest and/or of the seat part, with the filling having a foam support and a foam material, with the foam material at least partially surrounding the foam support, and with the foam material preferably completely surrounding the foam support. In this way, an improvement in the mechanical properties of the vehicle seat can be obtained in a simple manner in that the filling is arranged and formed such that, during the formation of the foam from the foam material (that is to say during the expansion of the foam material), firstly a good connection, in particular adhesive connection, with the inner surfaces or the inner wall of the structural element is obtained, and such that, secondly, easy insertion of the filling into the cavity is ensured, which leads to ease of assembly of the vehicle seat according to the invention.
It is particularly preferable according to the invention for the foam material to be provided so as to expand in an electrocoating kiln. In this way, the foam reinforcement of the vehicle seat can be integrated quickly and in a simple manner in terms of assembly by means of one working step which is carried out in any case.
It is particularly preferable if
the structural element forms, as a cavity, a hollow chamber which runs around in the manner of a frame in the backrest or in the seat part, with the hollow chamber having the foam material in its region facing toward a vehicle side region, with the foam material running in particular in a substantially C-shaped manner along the hollow chamber, and/or if the structural element is formed as a tube in the backrest or in the seat part and forms a hollow chamber which runs around in the manner of a frame, with the hollow chamber having the foam material in its region facing toward a vehicle side region, with the foam material running in particular in a substantially C-shaped manner along the hollow chamber, and/or if the structural element is reinforced by means of the foam material in the region of a belt rolling device, which is provided on the backrest, of an integral belt, in particular in the region of the upper transverse member of the backrest, and/or if the structural element is reinforced by means of the foam material in the region around a through-loading opening of the backrest, and/or if the vehicle seat is designed as a belt-integrated seat, with the structural element being reinforced by means of the foam material in the region of a side beam, which has a belt deflecting point or a belt rolling device, of the backrest.
In this way, it is possible according to the invention to obtain a targeted reinforcement at highly loaded points of the vehicle seat or of the backrest and/or of the seat part. It is also preferable according to the invention for a combination of a foam reinforcement to take place at more than one of said points. It is hereby advantageously possible according to the invention for the weight and costs of a vehicle seat of said type to be reduced in that, for example, the wall thickness of a metal material to be used, for example steel plate, or else plastic material need not imperatively be designed or selected such that mechanically highly loaded parts or regions of the vehicle seat withstand the occurring loadings, but rather conversely the wall thickness of a material to be used may be reduced and a reinforcement in the form of the filling with, inter alia, the foam material is provided at such mechanically highly loaded parts or regions of the vehicle seat.
A further subject matter of the present invention relates to a vehicle seat having a backrest and a seat part, with the backrest or the seat part having at least one structural element which has a cavity, with at least one part of the cavity having provided in it a filling which is introduced to influence the stability and/or the deformation behavior of the backrest and/or of the seat part and which has a foam material, wherein either
the structural element forms, as a cavity, a hollow chamber which runs around in the manner of a frame in the backrest or in the seat part, with the hollow chamber having the foam material in its region facing toward a vehicle side region, with the foam material running in particular in a substantially C-shaped manner along the hollow chamber,
or wherein
the structural element is formed as a tube in the backrest or in the seat part and forms a hollow chamber which runs around in the manner of a frame, with the hollow chamber having the foam material in its region facing toward a vehicle side region, with the foam material running in particular in a substantially C-shaped manner along the hollow chamber,
or wherein
the structural element is reinforced by means of the foam material in the region of a belt rolling device, which is provided on the backrest, of an integral belt, in particular in the region of the upper transverse member of the backrest,
or wherein
the structural element is reinforced by means of the foam material in the region around a through-loading opening of the backrest,
or wherein
the vehicle seat is designed as a belt-integrated seat, with the structural element being reinforced by means of the foam material in the region of a side beam, which has a belt deflecting point or a belt rolling device, of the backrest. In this way, according to the invention, there are advantageously also alternative possibilities for introducing the filling material into the cavity, for example the injection of plastic material for the formation of foam into the cavity.
Further subjects of the present invention relate to
a method for producing a vehicle seat according to the invention, wherein the structural element which has the cavity is formed in a first step, wherein the still-unexpanded filling, which has the foam support and the foam material, is introduced into the cavity in a second step, and wherein electrocoating is carried out in a third step during which the foam material expands, and to a method for producing a vehicle seat according to the invention, wherein the still-unexpanded filling, which has the foam support and the foam material, is positioned and/or fastened relative to a part of the structural element in a first step, wherein the cavity is formed in a second step, and wherein electrocoating is carried out in a third step, during which the foam material expands.
DRAWINGS
The figures schematically illustrate embodiments of the invention by way of example.
FIGS. 1 and 2 show a first embodiment of a vehicle seat according to the invention, or of one of its parts.
FIG. 3 shows a second embodiment of a vehicle seat according to the invention, or of one of its parts.
FIGS. 4 and 5 show a third embodiment of a vehicle seat according to the invention, or of one of its parts.
FIGS. 6 and 7 show a fourth embodiment of a vehicle seat according to the invention, or of one of its parts.
FIGS. 8 and 9 show a fifth embodiment of a vehicle seat according to the invention, or of one of its parts.
FIGS. 10 and 11 show a sixth embodiment of a vehicle seat according to the invention, or of one of its parts.
FIGS. 12 and 13 show schematic illustrations of a vehicle seat according to the invention, conforming with all of the embodiments.
DETAILED DESCRIPTION
FIGS. 12 and 13 show a vehicle seat according to the invention having features shared by all the embodiments of the present invention. A vehicle seat of said type comprises a seat part 2 and a backrest 3 . Both the seat part 2 and also the backrest 3 have in each case at least one structural element 4 which, below, is also referred to as a seat back segment, seat back structure, longitudinal beam, transverse beam, tube structure, side beam, pressed part or structure component. A cavity 5 is provided at least in partial regions in said structural element 4 , which cavity 5 is also referred to below as a hollow chamber. The cavity 5 is for example in the form of a frame substantially following the outer shape or periphery of the backrest 3 or of the seat part 2 , and is for example substantially round or oval or rounded (for example in the case of tube structures or tube-like structures) or else substantially angular, rectangular, triangular or angled (for example in the case of a U-shaped profile connected to a base plate) in cross section. According to the present invention, at least one partial region of the cavity 5 , and preferably also only one partial region of the cavity 5 , has arranged in it a filling 6 which comprises a foam material 8 . The filling 6 or the foam material 8 is also referred to below as a foam structure. The filling 6 or the foam material 8 may duly be injected from the outside by injecting an easily deformable or foaming material (for example through an opening in the cavity 5 ), but it is preferable according to the present invention for the filling 6 to be introduced into the cavity 5 in the form of a still-unexpanded and substantially hard, or at any rate substantially non-adhesive, foam material 8 which is connected to the foam support 7 , or else fastened to or positioned on a structure part which forms a cavity wall, with the cavity 5 then being formed by means of a connection to another structure part. In a subsequent step, the foam material 8 is then expanded, as a result of which the foam material 8 then at least partially or preferably completely surrounds the foam support 7 . To illustrate this, FIG. 13 shows a detail of a cavity 5 formed in the structural element 4 , with the filling 6 , that is to say the foam support 7 and the foam material 8 , being illustrated in the cavity 5 in the unexpanded state of the foam material 8 by means of solid lines, and with dashed lines or dots illustrating the limit of the foam material 8 in the foamed state. According to the invention, the expansion of the foam material 8 may take place in particular by means of a KTL bath treatment (not illustrated). This is to be understood to mean a treatment in an electrocoating kiln or a cathodic dip coating process in which the structural elements 4 of the vehicle seat are raised to a temperature of for example approximately 160° to approximately 180° over for example approximately 5 minutes to approximately 15 minutes, preferably approximately 10 minutes.
FIG. 1 shows the rear view of a split seat back structure of a first embodiment of a vehicle seat according to the invention, and FIG. 2 shows a section A-A through the seat back structure according to FIG. 1 . The seat back structure 11 of the split backrest of a vehicle rear seat bench is composed of a first seat back segment 12 and a second seat back segment 12 ′ which are split for example in the ratio 60:40. Each seat back segment comprises a base plate 13 , 13 ′ and a pressed part 14 , 14 ′ which is placed thereon and forms an encircling U-shaped profile. The base plates 13 , 13 ′ and the pressed parts 14 , 14 ′ are composed for example of metal, in particular sheet steel or aluminum, or of plastic, for example glass-fiber-reinforced plastic. Here, different materials may also be paired with one another. The seat back segments 12 , 12 ′ are mounted in the vehicle so as to be rotatable independently of one another by means of side mounts 15 , 15 ′ and a central mount 16 . Rotary latch locks 17 , 17 ′ arranged laterally on the upper side region of the seat back structure 11 serve to lock the seat back segments 12 , 12 ′ to the vehicle body, in particular to the C pillar, in the upright use position. The base plates 13 , 13 ′ and pressed parts 14 , 14 ′ together form hollow chambers 18 , 18 ′ which each run around in the manner of a frame. It is provided according to the invention that the outer side beam 19 and the adjoining regions of the upper transverse beam 110 and of the lower transverse beam 111 at least of the relatively large seat back segment 12 are filled with a stiffening foam structure 112 . In the rear view, the filled region in question of the hollow chamber 18 is of approximately C-shaped design ( FIG. 1 ). The introduction of the foam structure 112 may take place by inserting a finished foam part, which is shaped correspondingly to the hollow chamber 18 , before or during the welding of base plate 13 and pressed part 14 . Alternatively, the foam structure 112 is first introduced after the welding process by means of an injection of a foamable mass into the hollow chamber 18 . Particularly preferable, however, is the insertion of an in particular strand-like foam precursor, which has a three-dimensional shape, into the hollow chamber 18 , which foam precursor is inserted into the hollow chamber 18 before, during or after the welding process and foams to form the foam structure 112 after an activation. The activation may take place for example as a result of a supply of heat during the painting of the seat back structure 11 . For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. The seat back structure 11 is hereby stiffened in the region which is highly loaded in the event of an accident, in such a way that further locking devices—such as for example a so-called shot bolt or a torque lock—can be dispensed with.
FIG. 3 shows a second embodiment of the vehicle seat according to the invention. The structure of the rear seat bench 21 comprises separately pivotable seat back segments 22 , 22 ′ (separated for example into the ratio 60:40) of the backrest 3 and brackets 24 , 24 ′ which are fastened to the vehicle floor and which have tubular structure components 25 , 25 ′. The seat back segments 22 , 22 ′ are rotatably mounted on the respectively associated bracket 24 , 24 ′. A stiffening foam structure 26 is introduced into the mechanically particularly highly loaded regions A, B and C of the tubular structure components 25 , 25 ′, that is to say in particular into the longitudinal beams 27 , 27 ′, which run in the direction of travel, of the bracket 24 ′ of the relatively small seat back segment 22 ′ (regions A, B) and into that part of the transverse beam 29 of the bracket 24 assigned to the relatively large seat back segment 22 which faces toward the central mount 28 . The introduction of the foam structure 26 may for example take place by means of the injection of a foamable mass into the tubular structure components 25 , 25 ′. Particularly preferable, however, is the insertion of an in particular strand-like foam precursor, which has a three-dimensional shape, into the interior of the tubular structure components 25 , 25 ′, which foam precursor foams to form the foam structure 26 after an activation. The activation may take place for example as a result of a supply of heat during the painting of the brackets 24 , 24 ′. For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. In the second embodiment, the (at least partially) foam-filled structure parts are of tubular design.
FIG. 4 shows the rear view of a split seat back structure according to a third embodiment of the vehicle seat according to the invention, and FIG. 5 shows a section A-A through the seat back structure according to FIG. 4 . The seat back structure 31 of the split backrest of a vehicle rear seat bench is composed of a first seat back segment 32 and a second seat back segment 32 ′, which are split for example in the ratio 60:40. Each seat back segment 32 , 32 ′ comprises a base plate 33 , 33 ′ and a tube structure 34 , 34 ′ which is placed thereon and which runs around substantially in the manner of a frame. The base plates 33 , 33 ′ and the tube structures 34 , 34 ′ are composed for example of metal, in particular of steel or aluminum. Here, different materials may also be paired with one another. The seat back segments 32 , 32 ′ are mounted in the vehicle so as to be rotatable independently of one another by means of side mounts 35 , 35 ′ and a central mount 36 . Rotary latch locks 37 , 37 ′ arranged laterally on the upper side region of the seat back structure 31 serve to lock the seat back segments 32 , 32 ′ to the vehicle body, in particular to the C pillar, in the upright use position. The tube structures 34 , 34 ′ form substantially encircling hollow chambers 38 , 38 ′ which are each of frame-like design. It is provided according to the invention that the outer side beam 39 and if appropriate also the adjoining regions of the upper transverse beam 310 and of the lower transverse beam 311 at least of the relatively large seat back segment 32 are filled with a stiffening foam structure 312 . In the rear view, the filled region in question of the hollow chamber 38 is rudimentarily of C-shaped design ( FIG. 4 ). The foam structure 312 may for example be introduced by means of the injection of a foamable mass into the hollow chamber 38 . Particularly preferable, however, is the insertion of an in particular strand-like foam precursor, which has a three-dimensional shape, into the hollow chamber 38 , which foam precursor foams to form the foam structure 312 after an activation. The activation may take place for example as a result of a supply of heat during the painting of the seat back structure 31 . For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. The seat back structure 31 is hereby stiffened in the region which is highly loaded in the event of an accident, such that further locking devices can be dispensed with.
FIG. 6 shows the rear view of a split seat back structure of a fourth embodiment of the vehicle seat, and FIG. 7 shows a section A-A through the seat back structure according to FIG. 6 . The seat back structure 41 of the split backrest of a vehicle rear seat bench is composed of a first seat back segment 42 and a second seat back segment 42 ′ which are split for example in the ratio 60:40. Each seat back segment 42 , 42 ′ comprises a base plate 43 , 43 ′ and a pressed part 44 , 44 ′ which is placed thereon and forms an encircling U-shaped profile. The base plates 43 , 43 ′ and the pressed parts 44 , 44 ′ are composed for example of metal, in particular sheet steel or aluminum, or of plastic, for example of glass-fiber-reinforced plastic. Here, different materials may also be paired with one another. The seat back segments 42 , 42 ′ are mounted in the vehicle so as to be rotatable independently of one another by means of side mounts 45 , 45 ′ and a central mount 46 . Rotary latch locks 47 , 47 ′ arranged laterally on the upper side region of the seat back structure 1 serve to lock the seat back segments 42 , 42 ′ to the vehicle body, in particular to the C pillar, in the upright use position. The base plates 43 , 43 ′ and pressed parts 44 , 44 ′ together form hollow chambers 48 which each run around in the manner of a frame. A belt rolling device 410 of an integral belt is provided in the center of the upper transverse beam 9 . For further stiffening, a vertical beam 411 which is set into the pressed part 44 furthermore runs offset relative to said integral belt in the direction of the central mount 46 . It is provided according to the invention that the upper transverse beam 49 is filled with a stiffening foam structure 412 in the region of the belt rolling device 410 . The introduction of the foam structure 412 may take place by introducing a finished foam part, which is shaped correspondingly to the hollow chamber 8 , before or during the welding of the base plate 43 and pressed part 44 . Alternatively, the foam structure 412 is first introduced after the welding process by means of the injection of a foamable mass into the hollow chamber 48 . Particularly preferable, however, is the insertion of an in particular strand-like foam precursor, which has a three-dimensional shape, into the hollow chamber 48 , which foam precursor is placed into the hollow chamber 48 before, during or after the welding process and foams to form the foam structure 412 after an activation. The activation may take place for example as a result of a supply of heat during the painting of the seat back structure 41 . For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. The seat back structure 41 is hereby firstly stiffened in the region which is highly loaded in the event of an accident, and secondly the properties of said seat back structure 41 in the event of a head impact are improved. In particular, the deceleration of the test ball during the head impact test is improved.
FIG. 8 shows the rear view of a split seat back structure of a fifth embodiment of the vehicle seat according to the invention, and FIG. 9 shows a section A-A through the seat back structure according to FIG. 8 . The seat back structure 51 of the split backrest of a vehicle rear seat bench is composed of a first seat back segment 52 and a second seat back segment 52 ′ which are split in the ratio 60:40. Each seat back segment 52 , 52 ′ comprises a base plate 53 , 53 ′ and a pressed part 54 , 54 ′ which is placed thereon and forms an encircling U-shaped profile. The base plates 53 , 53 ′ and the pressed parts 54 , 54 ′ are composed for example of metal, in particular sheet steel or aluminum, or of plastic, for example of glass-fiber-reinforced plastic. Here, different materials may also be paired with one another. The seat back segments 52 , 52 ′ are mounted in the vehicle so as to be rotatable independently of one another by means of side mounts 55 , 55 ′ and a central mount 56 . Rotary latch locks 57 , 57 ′ arranged laterally on the upper side region of the seat back structure 51 serve to lock the seat back segments 52 , 52 ′ to the vehicle body, in particular to the C pillar, in the upright use position. The base plates 53 , 53 ′ and pressed parts 54 , 54 ′ together form hollow chambers 58 , 58 ′ which each run around in the manner of a frame. A through-loading opening 59 is also provided in the relatively large seat back segment 52 , which through-loading opening 59 is surrounded by the upper transverse beam 510 , the lower transverse beam 511 , the central-mount-side vertical beam 512 and a central vertical beam 513 of the pressed part 54 . Here, the central-mount-side vertical beam 512 is of particularly slim design in order to be able to arrange the through-loading opening 59 as centrally as possible in the rear seat bench and to be able to design said through-loading opening 59 to be as large as possible—for example such that said through-loading opening is larger than the transverse extent of a snowboard. It is provided according to the invention that at least the central-mount-side vertical beam 512 , if appropriate also the adjoining regions of the upper transverse beam 510 and of the lower transverse beam 511 , are filled with a stiffening foam structure 514 . The introduction of the foam structure 514 may take place by inserting a finished foam part, which is shaped correspondingly to the hollow chamber 58 , before or during the welding of the base plate 53 and pressed part 54 . Alternatively, the foam structure 514 is first introduced into the hollow chamber 58 after the welding process by means of the injection of a foamable mass. Particularly preferable, however, is the insertion of an in particular strand-like foam precursor, which has a three-dimensional shape, into the hollow chamber 58 , which foam precursor is placed into the hollow chamber 58 before, during or after the welding process and foams to form the foam structure 514 after an activation. The activation may take place for example as a result of a supply of heat during the painting of the seat back structure 51 . For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. The seat back structure 51 is hereby considerably stiffened in the region 530 which is highly loaded in the event of an accident.
FIG. 10 shows the perspective view of a vehicle seat according to the invention as per a sixth embodiment. FIG. 11 shows a section A-A through the vehicle seat according to FIG. 10 . The vehicle seat 61 shown in FIG. 10 has a seat part 62 and a backrest 63 and is designed as a belt-integrated seat in which a belt deflecting point 64 or the belt rolling device is fastened to the upper edge of the backrest 63 . The backrest 63 must therefore dissipate the belt forces into the vehicle floor via the seat back tilt adjuster 65 and the seat part 62 . The side beams 66 , 66 ′ of the backrest 63 are formed as U-shaped or hollow chamber profiles. In the exemplary embodiment, the side beams 66 , 66 ′, as shown in FIG. 11 , are composed of two U-shaped pressed sheet-metal parts 67 , 68 which are welded to one another at their limb ends in order to form a hollow chamber 69 . At least that side beam 66 which is assigned to the belt deflecting point is provided, in the interior of the hollow chamber 67 over significant regions of its longitudinal extent, with a foam structure 610 which increases the bending stiffness and/or torsional stiffness of the side beam 66 . The sheet-metal parts 67 , 68 may therefore be formed with a relatively small sheet-metal thickness. The introduction of the foam structure 610 may take place by inserting a finished foam part, which is shaped correspondingly to the hollow chamber 69 , before or during the welding of the sheet-metal parts 67 , 68 . Alternatively, the foam structure 610 is first introduced into the hollow chamber 69 after the welding process by means of the injection of a foamable mass into the hollow chamber 69 . Particularly preferable, however, is the insertion of an in particular strand-like or sheet-like foam precursor, which has a three-dimensional shape, into the hollow chamber 69 , which foam precursor is placed into the hollow chamber 69 before, during or after the welding process and foams to form the foam structure 610 after an activation. During the foaming of a U-shaped profile, the foaming direction of the foamable mass or of the foam precursor is predefined by suitable sealing means and/or the shape of the foam precursor. The activation may take place for example as a result of a supply of heat during the painting of the seat back structure 61 . For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide.
It is also preferably provided according to the invention that measures specified in one of the embodiments may also be used in one or more of the other embodiments. It is thus possible according to the invention in particular for a tubular structure part to be provided both in the backrest of the vehicle seat and also in the seat part of the vehicle seat (combination of the second embodiment with the third embodiment). It is also possible for the fourth and/or the fifth embodiment to be combined with one or more of the first, second or third embodiments.
|
A vehicle seat includes a backrest and a seat part, at least one of which has a structural element forming a cavity. A filling is disposed in the cavity and configured to influence the stability and/or the deformation behavior of the backrest and/or the seat part. The filling comprises a foam support and a foam material that at least partially surrounds the foam support.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/346,526, filed Jan. 8, 2002, the entirety of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to rods for reinforcing ductwork, and more particularly, to a reinforcing rod which is designed to enable a faster and easier installation into ductwork.
2. Description of the Related Art
Duct work, such as air conditioning ducts, are often made of a metallic material such as galvanized steel. These ducts require reinforcement to provide support to the ducts and to prevent them from bulging or buckling. One way that such reinforcement has been provided has been to surround the outside of the duct with an external reinforcement.
Another method that has been developed to reinforce air conditioning ducts and the like has been to position reinforcing rods or conduits on the interior of the ducts. In one previously known method, the length of the rod is threaded, and the rod is inserted into opposing holes in the walls of the duct and secured to these walls using a nut and washer configuration. One problem with this type of reinforcement is that the rods are necessarily longer than the distance between the walls of the duct, making it difficult to install the rods. This becomes especially problematic as the size of the duct decreases.
One previously known method to overcome this problem is to provide a conduit having a length corresponding to the distance between the opposing sides of the duct. Each end of the conduit is internally threaded, using an internally threaded nut press fit at each of the conduit. Then, by lining up the conduit with the opposing holes in the duct walls, bolts may be inserted from the outside of the duct through the internally threaded ends to secure the conduit within the ductwork. However, these conduits are difficult to align with the holes for insertion of the bolts. Moreover, these inserts can be pulled out of the conduits with a certain degree of force, thereby making the reinforcement ineffective.
Accordingly, what is needed is a method and apparatus for easily and quickly reinforcing an air conditioning duct and the like.
SUMMARY OF THE INVENTION
In one embodiment, a reinforcement is provided comprising a conduit having a first end and a second end. A pair of plugs is insertable into the first and second ends of the conduit. Each of the plugs has a groove extending along the circumference of the plug, and the plugs are crimped inside the conduit along the grooves. Each of the plugs may have a threaded end extending out of the plug and being retractable into said plug. Alternatively, each of the plugs may have an internally threaded opening extending at least partially through the plug. The reinforcement may then further comprise a bolt insertable into the threaded opening.
In another embodiment, a plug for insertion into an end of a conduit is provided. The plug comprises a body portion having a first end and a second end and an opening extending from the first end at least partially through said body portion. A groove extends at least partially along the circumference of the body portion, the groove adapted to receive a crimping force applied to the conduit when the plug is inserted into the end of the conduit. The plug may be internally threaded, or may further comprise a threaded member retractably positioned within the opening.
In another embodiment, a reinforced duct work is provided. The duct work has opposing surfaces, each of the surfaces having a hole therein aligned with an opposing hole. A conduit is provided having a first end and a second end, and has a plug inserted into each end thereof. Each plug has a groove extending along at least a portion of the plug, and the conduit is crimped to the plugs along the grooves. The conduit is positioned such that the first and second ends are aligned with the holes and the conduit is secured to the surfaces of the duct work. In one embodiment, the conduit may be secured to the surfaces of the duct work by bolts inserted through the holes in the duct work and into internally threaded holes in each plug at each end of the conduit. In another embodiment, each plug has a retractable threaded end which extends through one of the holes when the conduit is aligned therewith, and the conduit may be secured by nuts tightened over the retractable threaded ends against the surface corresponding to the holes.
In another embodiment, a method for reinforcing duct work is provided. The duct work has opposing surfaces, each of the surfaces having a hole therein aligned with an opposing hole. The method comprises providing a conduit having a first end and a second end, wherein the conduit has a plug inserted into each end thereof, each plug having a groove extending along at least a portion of the plug, and wherein the conduit is crimped to the plugs along the grooves. The conduit is positioned such that the first and second ends are aligned with the holes, and the conduit is secured to the duct work. In one embodiment, bolts may be inserted through the holes in the duct work and into internally threaded holes in each plug at each end of the conduit. The bolts are tightened within the plugs to secure the conduit to the duct work. In another embodiment, the plugs each have a retractable threaded end which extend through one of the holes when the conduit is aligned therewith. Nuts are tightened over the retractable threaded ends against the surface corresponding to the hole to secure the conduit to the duct work.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of air conditioning duct.
FIG. 2A is a perspective view of a plug with retractable threads according to one embodiment of the present invention, the threads being shown in their unretracted configuration.
FIG. 2B is a perspective view of a plug with retractable threads according to one embodiment of the present invention, the threads being shown in their retracted configuration.
FIG. 2C is a perspective view of another embodiment of a plug with retractable threads.
FIG. 2D is a cut away side view of the body portion of the plug of FIG. 2 C.
FIG. 2E is a side view of a spring insertable into the plug of FIG. 2 C.
FIG. 2F is a side view of a tube cap for the plug of FIG. 2 C.
FIG. 2G is a side view of an inside bolt for the plug of FIG. 2 C.
FIG. 2H is a top view of the body portion of FIG. 2 D.
FIG. 2I is a bottom view of the body portion of the FIG. 2 D.
FIGS. 2J and 2K are side and top views, respectively, of a rubber washer.
FIGS. 2L and 2M are side and top views, respectively, of an outside nut.
FIG. 3 is a side view of a conduit having a plug of with retractable threads inserted into its ends.
FIG. 4 is a perspective view of the air conditioning duct of FIG. 1 reinforced by the conduit of FIG. 3 .
FIGS. 5A-5C are perspective views illustrating the insertion and crimping of grooved plugs into a conduit.
FIG. 5D is a partial cross-sectional view of an end of a conduit having a plug crimped therein.
FIG. 5E is a side view of an end of a conduit having a plug crimped therein.
FIG. 6A is a cross-sectional view of one embodiment of a grooved plug.
FIG. 6B is an end view of the plug of FIG. 6 A.
FIG. 7A is a cross-sectional view of another embodiment of a grooved plug.
FIG. 7B is an end view of the plug of FIG. 6 A.
FIG. 8A is a perspective view of the air conditioning duct of FIG. 1 , with the conduit of FIG. 5C inserted therein.
FIG. 8B is a perspective view of the air conditioning duct of FIG. 1 reinforced with the conduit of FIG. 5 C.
FIGS. 9A-9D illustrate one preferred sequence for crimping a conduit to a plug.
FIG. 10 is a perspective view of another embodiment of a plug having retractable threads.
FIG. 11A is a cross-sectional view of the plug of FIG. 10 .
FIG. 11B is an end view of the plug of FIG. 11 A.
FIG. 12 is a perspective view of another embodiment of a plug having retractable threads being inserted into a conduit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of this invention relate to reinforcement of duct work (e.g., for air conditioning ducts), and more particularly, to conduits used for reinforcing duct work. In particular, certain embodiments describe plugs for insertion into the ends of the conduits in order to provide for easier insertion into the duct work and/or a more secure connection and reinforcement.
FIG. 1 illustrates a portion of air conditioning duct 10 . The duct has opposing surfaces 12 and 14 , which include oppositely disposed holes 16 . As described below, these holes 16 are used to reinforce the duct 10 to prevent it from buckling or collapse.
FIGS. 2A and 2B illustrate a plug with retractable threads according to one embodiment of the present invention. The plug 18 , shown in its unretracted configuration in FIG. 2A , includes a threaded end 20 , which moves into and out of the tubular body portion 24 through head 22 . The threaded end 20 is integrally formed with a shaft 28 which remains internal to the tubular body portion 24 . A spring (not shown) is also positioned within the tubular body portion 24 below the shaft 28 .
Provided on the shaft 28 is a pin 30 , which extends into an L-shaped cutout 26 provided in the wall of the body portion. The spring within the body portion presses against the bottom of the shaft 28 , forcing the threaded end 20 outward relative to the head 22 , and correspondingly, positioning the pin at the top of the “L.” Thus, the pin 30 , when contacting the top of the L-shaped cut-out, prevents the threaded end 20 and the shaft 28 from exiting the body portion 24 , and also prevents rotation of the threaded end 20 .
FIG. 2B illustrates that because of the spring within the body portion, the threaded end 20 can be pushed down, compressing the spring and thereafter moving the pin 30 into the bottom-right portion of the L-shaped cut-out. Thus, in this position, the threaded end 20 is in a “locked” or retracted configuration. Preferably, the threaded end 20 will still extend slightly beyond the head 22 in this locked configuration.
It will be appreciated that although the plug 18 has been described as containing a locking mechanism 26 , the plug may also be provided without such a locking mechanism. In such an embodiment, the plug 18 is in a relaxed position when the threaded end 20 is fully extending out of the body portion 24 , as shown in FIG. 2 C. Because of the spring inside the body portion 24 , when a force is placed against the threaded end 20 , causing the threaded end to move into the body portion, the threaded end will be biased to move back to its relaxed position unless the force on the threaded end is maintained.
FIGS. 2D-2G illustrate the components of the plug 18 of FIG. 2C , according to one preferred embodiment The body portion 24 , shown in FIG. 2D , has a head portion 22 at its proximal end defining an opening 40 through which threaded end 20 , described below, extends. The walls 42 of the body portion 24 are preferably tapered, such that the cavity 46 inside the body portion has a smaller diameter toward the proximal end of the body portion. FIG. 2H shows a top view of the body portion 24 . As shown in the bottom view of the body portion 24 of FIG. 2I , the cavity 46 is preferably hex-shaped to accommodate a bolt having a hex-shaped base, as described below.
Provided inside the cavity of the body portion 24 are a spring 48 (shown in FIG. 2E ) and an inside bolt 52 (shown in FIG. 2 G). The inside bolt 52 includes a threaded end 20 extending from its proximal end, a hex-shaped base 44 at its distal end, and a shaft 28 therebetween. The inside bolt 52 is inserted into the cavity of the body portion 24 through its distal end, with the threaded end 20 entering first. The threaded end 20 is sized to pass through the opening 40 , but the hex-shaped base 44 is sized larger than the opening 40 to prevent the inside bolt from falling out of the body portion 24 at its proximal end. Moreover, the hex-shaped base 44 approximately mates with the hex-shaped cavity 46 to prevent rotation of the bolt within the cavity. The spring 48 is inserted through the distal end of the body portion 24 after the inside bolt 52 . A tube cap 50 , as shown in FIG. 2F , seals the body portion 24 after the spring and inside bolt 52 have been inserted. The body portion 24 and the tube cap 50 are preferably made of a material such as aluminum or plastic. The other components of the plug are preferably made of a material such as steel and plated to prevent rust.
FIG. 3 illustrates that to reinforce an air conditioning duct such as shown in FIG. 1 , the plugs 18 are placed in the two ends 34 , 36 of a reinforcing conduit 32 . Preferably, the plugs are press fit into the two ends. The distance between the two ends 34 , 36 is preferably substantially the same as the distance between the opposing surfaces 12 , 14 of the air conditioning duct.
To install the reinforcing conduit into the duct 10 , the conduit 32 is inserted between the opposing surfaces 12 , 14 of the duct 10 . The threaded ends 20 of the plugs in the conduit, when pressed against the walls of the duct, are forced into the body portions 24 , thereby shortening the length of the conduit with the plugs. This enables the conduit to be moved around more easily within the duct. The conduit 32 is preferably moved within the duct 10 until the threaded ends 20 encounter the opposing holes 16 of the duct. When the threaded ends 20 are free to unretract from the body portions 24 (i.e., the embodiment of FIG. 2C , wherein the threaded ends are not locked inside the body portion with a locking mechanism), the threaded ends will pop out once encountering the holes and extend to the outside of the duct 10 .
Alternatively, if the threaded ends are locked such as shown in FIG. 2B above, because the threaded ends 20 extend slightly beyond the head 22 , the installer can still ascertain when the threaded end encounters a hole 16 . Then, the threaded ends 20 can be activated to their unretracted position simply by moving the pin 30 from the locked to the unlocked position.
It will be appreciated that when installing conduit as described above, it is often advantageous to install one end of the conduit 32 first into a hole 16 , with the threaded end 20 at that one end already unretracted, and then simply orienting the conduit such that the other threaded end 20 encounters the opposing hole 16 . In this embodiment, as the other threaded end 20 is brought towards the opposing hole 16 , the end 20 will likely retract into the conduit as the force of the wall nearby the opposing hole 16 presses the threaded end 20 into the body portion 24 .
In another embodiment, it will be appreciated that a conduit may be provided in which only one end has a retractable threaded end, while the other end has an threaded end which always extends out of the end of the conduit.
FIG. 4 illustrates a partially completed reinforced duct portion 10 with a reinforcing conduit 32 therein. As can be seen, the threaded ends 20 extend to the external surface of the duct, wherein an outside nut 38 is screwed onto the threaded end 20 and against the surface of the duct walls to secure the conduit in place. This nut 38 is shown more particularly in FIGS. 2L and 2M . When a body portion such as shown in FIG. 2D is used, as the outside nut 38 is screwed onto the inside bolt 52 of the body portion, the nut draws the bolt towards the nut. Because the walls 42 of the body portion 24 are tapered, the hex-shaped base 44 of the inside bolt 52 presses against the walls as the bolt 52 is drawn toward the nut 38 . This exerts an additional pressure of the body portion 24 against the inner walls of the conduit 32 , thereby holding the plug 18 more strongly within the conduit.
FIG. 4 also illustrates the use of a rubber washer 54 , illustrated more particularly in FIGS. 2J and 2K . Prior to installation, rubber washers 54 can be placed against the heads 22 of the plugs 18 at each end of the conduit 32 , with the threaded ends 20 extending through the holes 56 in the washers. Then, once the plugs 18 are aligned in the duct 10 and the threaded ends 20 extend through the holes 16 , the rubber washers 54 abut against the surfaces 12 , 14 of the duct to protect the duct from damage.
The embodiments described also improve over the prior art in which threaded reinforcement rods are used in that reinforcing conduits as described herein are stronger than threaded rods and therefore are more resistant to buckling.
FIGS. 5A-5C illustrate another embodiment of a system for reinforcing air conditioning ducts and the like. In this embodiment, a conduit 32 such as described above is provided. Plugs 58 and 60 having an outer diameter corresponding to the inner diameter of the conduit are inserted into ends 34 and 36 of the conduit, respectively, until the outer ends of the plugs are flush with the ends of the conduit, as shown in FIG. 5 B. As described in further detail below, the plugs 58 and 60 each have a groove 62 extending around the circumference of the plug and have an internally threaded opening 64 extending through the central axis of the plug. After the plugs are inserted into the conduit, a crimping device, such as described below, can be used to crimp the conduit at the location of the grooves 62 , shown by the arrows in FIG. 5 B. As shown in the resulting conduit in FIG. 5C , the crimping of the conduit locks the plugs 58 and 60 within the conduit at crimped locations 62 A and 62 B to prevent the plugs from being pulled out. FIG. 5D illustrates in cross-section one preferred plug crimped inside an end of a conduit, with a bolt screwed into the threaded opening 64 through a washer. FIG. 5E illustrates an end view of the crimped conduit.
FIGS. 6A and 6B illustrate one preferred design for the plugs 58 and 60 . In this embodiment, the threaded opening 64 preferably has a diameter of about ¼″ and extends entirely through the plug. The plug in one embodiment has a diameter of about 0.605″ and a length of about 0.69″, with the groove located about 0.33″ from the outer end of the plug (i.e., the end that is flush with the end of the conduit) and about 0.15″ from the inner end of the plug. The groove 62 in this embodiment preferably has a length of about 0.21 inches. As shown in FIG. 6B , the groove preferably has a depth of about 0.07 inches.
FIGS. 7A and 7B illustrate another preferred design for the plugs 58 and 60 . In this embodiment, the threaded opening 64 also has a diameter of about ¼″, and the length and location of the groove are the same. However, the plug of FIGS. 7A and 7B has a diameter of about 0.81″. It will be appreciated that plugs of various sizes may be used to accommodate different sized conduits.
FIG. 8A illustrate that after the plugs are inserted and crimped into the conduit as shown in FIG. 5C , the conduit can be aligned with holes 16 in the duct 10 . As shown in FIG. 8B , from the outside of the duct, a washer 66 is positioned over the hole 16 and a bolt 68 is inserted through the washer, through the hole 16 , and threadedly inserted into the opening 64 to secure the conduit within the duct. This process is repeated for each end of the conduit and for each conduit positioned in the duct.
It will be appreciated that the plugs 58 and 60 can be made from a variety of suitable materials. For example, certain preferred materials include, but are not limited to, nylon, steel and aluminum. Desired materials may be selected based on the superior pull out strength offered by the crimped plugs. For example, a nylon plug which has been injection molded desirably provides a pull out strength of about 800 to 1200 lbs. A steel plug desirably provides a pull out strength of about 3200 to 5000 lbs. An aluminum plug desirably provides a pull out strength of about 1500 to 2500 lbs. It will also be appreciated that to provide increased pull out strength, more than one groove 62 may be provided on the plugs.
Crimping of the plugs 58 and 60 to the conduit can preferably be accomplished using any suitable crimping device. One such device is shown in FIGS. 9A-9D . As shown in FIG. 9A , a pneumatic fixture is bench mounted, with a peg extending vertically from the bench. A plug is slipped over the peg, as shown in FIG. 9 B. The plug is covered with a conduit, shown in FIG. 9C , which preferably has a ½″ or ¾″ diameter. Using the pneumatic crimping device, the conduit is crimped, preferably in only about one second, onto the plug, as shown in FIG. 9 D. It will be appreciated that various crimping mechanisms can be used, and therefore, the plug need not be crimped by the device or methods shown in FIGS. 9A-9D .
FIG. 10 illustrates another design of a plug 70 having a retractable threads similar to the embodiment of FIG. 2 C. The plug includes a threaded end 72 , which moves into and out of the tubular body portion 74 . The threaded end 72 is integrally formed with a shaft 76 (not shown) which remains internal to the tubular body portion 74 in an opening 88 (described below). A spring 78 (shown in FIG. 11A ) is also positioned within the opening 88 of the tubular body portion 74 below the shaft 76 .
Provided on the shaft 76 is a pin 80 , which extends into a slot 82 provided in the wall of the body portion. The spring within the body portion presses against the bottom of the shaft 76 , forcing the threaded end 72 outward, and correspondingly, positioning the pin at the top of the slot 82 . Thus, the pin 80 , when contacting the top of the slot, prevents the threaded end 72 and the shaft 76 from exiting the body portion 74 , and also prevents rotation of the threaded end 72 .
Near the top of the slot 82 , a passageway 84 is provided to allow the threaded end 72 and the shaft 76 to exit the tubular body portion 74 . An operator can remove the threaded end from the body portion 74 by pressing slightly down on the threaded end 72 , and turning the threaded end (in the embodiment shown, counter-clockwise) such that the pin 80 follows the passageway 84 . The passageway 84 turns up toward the top end of the body portion 74 , which allows the threaded end to be removed.
The tubular body portion further includes a groove 86 near the end of the plug opposite the threaded end 72 . This groove, as with the embodiments of FIGS. 5A-5C described above, enables the plug to be inserted into a conduit and crimped therein to provide excellent pull out strength. Once the plug is inserted and crimped at each end of the conduit, a duct can be reinforced such as shown in FIG. 4 above.
FIGS. 11A and 11B illustrate one preferred design for the plug 70 . In this embodiment, the opening 88 in which the spring 78 and the shaft 76 are inserted preferably has a diameter of about {fraction (5/16)}″ and a depth of about 1.4″. The overall length of the plug is about 1.5″, with the groove 86 located about 1.14″ from the outer end of the plug (i.e., the end that is flush with the end of the conduit) and about 0.15″ from the inner end of the plug. The groove 86 in this embodiment preferably has a length of about 0.21 inches and a depth of about 0.07″. The slot 82 and passageway 84 preferably have a width of about {fraction (3/16)}″, with the bottom of the slot located about 1.09″ from the outside end of the plug. The plug can have a variety of diameters, and in two preferred embodiments, has a diameter of about 0.81″ or about 0.605″.
FIG. 12 illustrates an alternative embodiment of a plug having retractable threads being inserted into a conduit. This plug design is similar to the design of FIG. 2C , except that the walls 42 of the tubular body portion 24 have slots extending longitudinally therein from the inner end of the plug (i.e., the end adapted to be positioned away from the end of the conduit) and partially toward the head 22 . Like the embodiment of FIG. 2C , the walls 42 are tapered such that the cavity 46 inside the body portion has a smaller diameter toward the proximal end or top end of the body portion.
Although the embodiments described herein relate to reinforcement of air conditioning ducts, it will be appreciated that the preferred embodiments of the present invention may be used in other applications as well. It will be appreciated that the plugs 18 described above may be used in applications with and without the conduit 32 . For example, a conduit having plugs with retractable threads may be used for inserting shower curtain rods. In another example, plugs with retractable threads may be used for furniture legs. In such an embodiment, in fact, the retractable portion of the plug need not be threaded. Other possible uses include hangers between doors and inside closets, and clothes hangers in automobiles.
It should be understood that certain variations and modifications of this invention will suggest themselves to one of ordinary skill in the art. The scope of the present invention is not to be limited by the illustrations or the foregoing descriptions thereof, but rather solely by the appended claims.
|
A method and apparatus for reinforcing duct work is provided. In one embodiment, a reinforcement comprises a conduit having a first end and a second end. A pair of plugs is insertable into the first and second ends of the conduit. Each of the plugs has a groove extending along the circumference of the plug, and the plugs are crimped inside the conduit along the grooves. Each of the plugs may have a threaded end extending out of the plug and being retractable into said plug. Alternatively, each of the plugs may have an internally threaded opening extending at least partially through the plug. In this embodiment, the conduit can be secured to duct work by aligning the conduit with holes in the duct work, and inserting a bolt through the holes and into the internally threaded openings of the plugs.
| 8
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] Embodiments of the present invention relate, in general, to integrated computing and storage systems and particularly to a system for automated integration of modular computer and storage components.
[0003] 2. Relevant Background
[0004] A computer system can be characterized as a diverse combination of electronic components that function together as a cohesive entity. In its simplest terms, a computer consists of a processor, some form of a storage medium, and a means to communicate between the processor and storage medium. A personal computer, for example, typically includes one microprocessor, a combination of read only memory and random access memory, and a communication bus to transfer data and code between the processor and the various forms of memory.
[0005] When a user elects to expand the capability of a personal computer, for example to expand the storage capability, one option is to purchase a larger hard drive that is either internally or externally based. Depending on the type and brand, this added storage capability can be added in what is known to one skilled in the art as “plug and play”. And while it is possible to couple two or more personal computers together to increase computational capability, such a task is not trivial. For example, consider the difficulty in linking a computer based on an Apple® operating system to one operating on a Microsoft® operating system so as to utilize both processors to address a problem present on a UNIX® based machine.
[0006] In network computing, the independent nature of compute and storage components becomes even more pronounced. A typical computing system includes several components. Typically a component is primarily a storage component or a compute component. These components are linked together by a network infrastructure such as routers, switches, gateways, and the like. When such a compute or storage component is added to an established network system, it is essentially an island unto itself. Beyond plugging the component into the same wall outlet for electrical power, a component newly added, to an established enterprise system has little ability to interact with any other system component. Without customizing network adapters, installing an operating system, modifying existing protocols to meet the network protocol, configuring network interfaces, and countless other configuration tasks, the component fails to be interoperable with the other components of the enterprise system.
[0007] Historically, operational costs of an enterprise system are many times greater than the initial capital outlay. In part this is due to the need to integrate each component as it is added to a system. However, operational costs do not cease once a component has been incorporated into a system. The cost of maintaining a system of compute and storage components is significant. To minimize these costs, entities strive to maintain a system that does not impede operations from lack of resources yet does not possess significant excess capabilities. Unfortunately systems today are designed for surge requirements. For example, during the holiday shopping period, an e-commerce provider may need 100 servers to ensure that customers are promptly and accurately provided with the ability to conduct a transaction. Even a momentary lapse in the system's capability can result in significant monetary losses. Thus systems are designed to address this momentary need yielding, during other periods, a highly inefficient storage and compute infrastructure. And while theoretically it may be possible for a technician to disconnect surplus components and then reinitialize them when needed, the cost of doing so is prohibitive when compared to simply maintaining their operational status. Thus many enterprise systems can be characterized as having vast amounts of excess capability over the majority of a system's life span. A challenge remains, therefore, for a system in which compute and storage components are modular such that they can be added and/or removed in an automated manner. These and other challenges present in the prior art are addressed by the present invention.
SUMMARY OF THE INVENTION
[0008] A modularized computing system, according to one embodiment of the present invention, includes a plurality of modular components that are coupled together forming a network. Each modular component includes a network interface that is common throughout the network. The system further includes an initialization module, a monitor module, a storage medium, and a management module. As a module unit is coupled to the network, the initialization module automatically configures the component to an operable state. The monitor module monitors network operations including performance parameters of each modular component based on a plurality of system policies stored in the storage medium. Based on information gathered by the monitor module, the management module actively modifies network structure and resource allocation to optimize network performance.
[0009] According to one embodiment of the present invention, performance parameters conveyed to the management module by the monitor module are compared to established system policies. Responsive to a module failing to meet an established policy, the management module automatically modifies the network by altering resource allocations within the existing network or by modifying the network structure itself. To maintain operations of the computing system in compliance with the system policies, the management module can add or remove modular components from the network. In addition, the management module can logically make a module component unavailable to network applications.
[0010] At least one embodiment of the present invention also includes the superimposition of logical data interconnects over the physical interconnect structure of the network so as to enable the management module to logically manage the network. The management module, according to one embodiment, can modify operational tasks of the modular components of the system based on each component's ability to be in compliance with the system policies. This modification can be accomplished dynamically or periodically and is automatic needing no user initiation or authorization.
[0011] The features and advantages described in this disclosure and in the following detailed description are not all-inclusive. Many additional features and advantages will be apparent to one of ordinary skill in the relevant art in view of the drawings, specification, and claims hereof. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes and may not have been selected to delineate or circumscribe the inventive subject matter; reference to the claims is necessary to determine such inventive subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The aforementioned and other features and objects of the present invention and the manner of attaining them will become more apparent, and the invention itself will be best understood, by reference to the following description of a preferred embodiment taken in conjunction with the accompanying drawings, wherein:
[0013] FIG. 1 shows a networked computer environment in which one embodiment of the present invention is implemented and
[0014] FIG. 2 shows a flowchart of one method embodiment for managing a modular computing system according to the present invention.
[0015] The Figures depict embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.
DETAILED DESCRIPTION OF EMBODIMENTS
[0016] A modular computing system comprising a plurality of modular components coupled together via an interface common throughout the network is herein disclosed by way of example. According to one embodiment of the present invention, a plurality of modular components is coupled together to form a computing system. Included in the system is a plurality of modules configured to monitor, initialize, and manage the system's modular components.
[0017] Specific embodiments of the present invention are hereafter described in detail with reference to the accompanying Figures. Like elements in the various Figures are identified by like reference numerals for consistency. Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the combination and arrangement of parts can be resorted to by those skilled in the art without departing from the spirit and scope of the invention.
[0018] FIG. 1 is a high level block diagram of a computing system 100 comprising a plurality of managed modular components 110 , 120 . In this embodiment of the present invention, a plurality of compute modules 120 and storage modules 110 are coupled together via a network infrastructure 130 to form a computing system 100 . A compute module 120 , as will be understood by one skilled in the relevant art, is a computer, server or the like whose primary functionality is processing of data. Similarly, a storage module 110 is a modular component whose primary function is one of storage of data. To some degree a compute module 120 will possess some ability to store data and a storage module 110 will have some ability to process data; however, the functionality and design of each is such that its primary role, be it storage or computing, is driven by its inherent capabilities. For example, a compute module 120 may possess a number of processors including field programmable gate arrays. Conversely, a storage module 110 may include one of many forms of storage media including hard disk, tape, flash, etc. While each module possesses an interface to the system 100 , the actual capabilities of each module can vary. Indeed one advantage of the present invention is to optimize performance of the system by capitalizing on the differing capabilities of each of the plurality of modular components 110 , 120 .
[0019] Turning again to FIG. 1 , the system 100 also includes an initialization module 150 , a monitor module 160 , and a management module 170 . Each of these modules is coupled so that they may interact with one another as well as with the remaining modular components 110 , 120 of the system 100 . In addition to these modules, a storage medium 175 is coupled to the management module 170 , according to one embodiment of the present invention, to provide to the management module 170 a plurality of system policies.
[0020] The policies maintained within the storage medium 175 and utilized by the management module 170 identify guidelines from which the management module 170 can implement modifications to the system 100 . In addition, policies can include performance utilization parameters and/or indices that the management module can use to determine whether one or more components should be added or removed from the system or whether application tasks should be reallocated.
[0021] The storage medium 175 can, according to another embodiment of the present invention, include initialization protocols that can be transferred to the initialization module 150 . When a new module is added to the system 100 or when an existing module has been removed and then at a later time is returned to an operational state, the initialization module 150 , using protocols gained from the storage medium 175 , automatically initializes the component and brings its capabilities online to the system 100 . Similarly, when the management module 170 determines that a component's resources are no longer benefiting the system 100 and determines the system 100 would be better off without the component's contribution, the initialization module 150 can initialize procedures to remove the component from the system and place it into a dormant state.
[0022] According to one embodiment of the present invention, policies, protocols, procedures, indices and the like are predetermined and presented to the management module 150 for automatic implementation. In another embodiment of the present invention, policies stored in the storage medium 175 can be modified to reflect a changing environment.
[0023] As previously discussed and shown in FIG. 1 , the monitor module 160 is coupled to the management module 170 and the system 100 . The monitor module gathers information from each of the plurality of modular components 110 , 120 throughout the system 100 . Information including utilization of component resources, application tasks assigned to each of the components, and other performance indices is gathered by the monitor module 160 and conveyed to the management module 170 . In one embodiment of the present invention, information gathered by the monitor module 160 is analyzed to determine whether the information complies with existing policies. When a component fails to meet an established policy or performance parameter, the identity of the component and the details of the policy breach are conveyed to the management module 170 for action. In other embodiments, the monitor module 160 conveys information to the management module 170 on a real time basis.
[0024] Based on information gathered by the monitor module 160 , the management module 170 can automatically modify the system 100 . Modification by the management module 170 can be done dynamically or periodically, and the scope of the modification can range from reallocation of component assigned tasks and resources to modification of the system structure itself. Due to the modular nature of each component 110 , 120 that comprises the system 100 , the management module has the ability to add and remove components at will. This capability is coupled with the ability to initialize a new module automatically.
[0025] For example, assume that the monitor module 160 reports to the management module 170 that several compute components 120 are being under utilized yet the many storage components 110 of a particular type are beyond an established storage capacity target. The management module 170 , based on established policies and procedures, can ascertain via the monitor module 160 what application tasks are assigned to each component. Using information regarding each of the components' capabilities and utilization, the management module can reallocate application tasks to make some components more fully utilized in compliance with system policies thus rendering other components, in this case compute components, essentially idle.
[0026] Those compute components 120 that are idle can be removed from the system. At the same time the management module can add new storage components to address the need for additional storage space, or conversely, implement transfer of data to other types of storage mediums already established within the system that are not fully utilized. To the extent new resources need to be added to the system 100 , the management module 170 , working in conjunction with the initialization module 150 , automatically brings the resources of a new component online.
[0027] FIG. 2 is a flowchart illustrating a method of implementing an exemplary process for managing a modular computing system. In the following description, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be loaded onto a computer or other programmable apparatus to produce a machine such that the instructions that execute on the computer or other programmable apparatus create means for implementing the functions specified in the flowchart block or blocks. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable apparatus to function in a particular manner such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means that implement the function specified in the flowchart block or blocks. The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operational steps to be performed in the computer or on the other programmable apparatus to produce a computer implemented process such that the instructions that execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.
[0028] Accordingly, blocks of the flowchart illustrations support combinations of means for performing the specified functions and combinations of steps for performing the specified functions. It will also be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by special purpose hardware-based computer systems that perform the specified functions or steps, or combinations of special purpose hardware and computer instructions.
[0029] One embodiment of a method for managing a computing system comprising modular components begins 205 with the formation 210 of the system using a plurality of commonly interfaced compute and storage components. Thereafter each of the plurality of components is automatically initialized 230 including installation of any needed communication and network protocols and/or other parameters necessary for each component to be a working member of the system.
[0030] From that point forward, each component in the system is monitored 260 by the monitor module. Each component is monitored for compliance with existing policies as well as indications that a component is either over utilized or under utilized. This, and other information, is used to manage 280 the plurality of network components and the applications which they are conducting. As a result 295 of this management, the system can operate more efficiently. As the removal and addition of modular components from and to the system is automatic, the present invention has the advantage of being able to automatically, and without the incurrence of additional cost, maintain individual component utilization and performance at peak levels. No longer do components operate at a fraction of their capacity or do excess components exist on a system simply because of surge periods. The modular nature of each component enables the system to minimize human interaction and thus optimizes system performance.
[0031] As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Likewise, the particular naming and division of the modules, managers, functions, systems, engines, layers, features, attributes, methodologies, and other aspects are not mandatory or significant, and the mechanisms that implement the invention or its features may have different names, divisions, and/or formats. Furthermore, as will be apparent to one of ordinary skill in the relevant art, the modules, managers, functions, systems, engines, layers, features, attributes, methodologies, and other aspects of the invention can be implemented as software, hardware, firmware, or any combination of the three. Of course, wherever a component of the present invention is implemented as software, the component can be implemented as a script, as a standalone program, as part of a larger program, as a plurality of separate scripts and/or programs, as a statically or dynamically linked library, as a kernel loadable module, as a device driver, and/or in every and any other way known now or in the future to those of skill in the art of computer programming. Additionally, the present invention is in no way limited to implementation in any specific programming language, or for any specific operating system or environment.
[0032] While there have been described above the principles of the present invention in conjunction with a system for modular computing, it is to be clearly understood that the foregoing description is made only by way of example and not as a limitation to the scope of the invention. Particularly, it is recognized that the teachings of the foregoing disclosure will suggest other modifications to those persons skilled in the relevant art. Such modifications may involve other features that are already known per se and which may be used instead of or in addition to features already described herein. Although claims have been formulated in this application to particular combinations of features, it should be understood that the scope of the disclosure herein also includes any novel feature or any novel combination of features disclosed either explicitly or implicitly or any generalization or modification thereof which would be apparent to persons skilled in the relevant art, whether or not such relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as confronted by the present invention. The Applicant hereby reserves the right to formulate new claims to such features and/or combinations of such features during the prosecution of the present application or of any further application derived therefrom.
|
A modularized computing system includes a plurality of modular components that are coupled together forming a network. Each modular component includes a standard network interface. The system further includes an initialization module, a monitor module, a storage medium, and a management module. As a module unit is coupled to the network, the initialization module automatically configures the component to an operable state. The monitor module monitors network operations including performance parameters of each modular component based on a plurality of system policies. Based on information gathered by the monitor module, the management module actively modifies network structure and resource allocation to optimize network performance.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation application claiming the benefit of U.S. patent application Ser. No. 13/914,017, which was filed on Jun. 10, 2013, the entirety of which is hereby incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to firearms. More particularly, the present invention relates to stock kits which convert a traditional rifle into bullpup configuration.
2. Description of the Prior Art
Traditionally rifles using detachable magazines are configured so that the action of the firearm and the ammunition magazine are located in front of the trigger. Rifles configured so that the action and the magazine are located behind the trigger of the firearm are referred to as “Bullpups”.
Rifles in a bullpup configuration offer several advantages over the more traditional rifle configuration. One of these advantages relates to barrel length. A bullpup having the same overall length as a traditionally configured rifle will have a longer barrel. This is due to the positioning of the action closer to the rear end of the buttstock. Longer barrels are typically associated with increased accuracy and better external and terminal ballistic performance.
While the action and the mounting position of the ammunition magazine are moved towards the rear end relative to the buttstock, the position of the trigger stays relatively the same. This requires a new mechanism to place the trigger and the sear of the firearm's action into operational communication.
In certain instances, end users of more traditional rifles may desire to alter the appearance and functionally of their more traditionally configured rifle into that of a bullpup. This may be done to improve ergonomics, reduce weight, and reduce overall length without compromising ballistic performance. Such a modification would be particularly desirable if it required minimal expertise and mechanical skill.
In addition to a new rifle stock kit for the host firearm, a mechanism to reposition the trigger forward of the action and the magazine must be provided for in order to complete the bullpup conversion.
Therefore in consideration of what is available in the prior art, there exist a need for a rifle stock kit which converts a traditionally configured rifle into bullpup configuration. Such a stock kit should require minimal gunsmithing knowledge or mechanical expertise to install and provide a mechanism to reposition the trigger forward of the action and the magazine.
SUMMARY OF THE INVENTION
In view of the foregoing, one object of the present invention is to meet the recognized need for such an apparatus that converts a traditionally configured rifle into bullpup configuration by providing a rifle stock kit which includes a mechanism for repositioning the trigger.
Another object of the present invention is to provide a rifle stock kit in accordance with the preceding objects which provides for a rotatable handguard that may be used as vertical foregrip.
Yet another object of the present invention is to provide a rifle stock kit in accordance with the preceding objects which provides a mechanism to facilitate removal of the ammunition magazine.
A further object of the present invention is to provide a rifle stock kit in accordance with the preceding objects which provides a trigger safety mechanism.
In accordance with these and other objects, the present invention is directed to a rifle stock kit which is configured to receive the barreled action of a firearm and convert it to a bullpup configuration. The rifle stock kit consists of a three piece chassis system, a mechanical device to connect the trigger provided by the stock kit to the sear of the barreled action, a mechanical trigger safety, a rotatable handguard and a magazine release. The preferred embodiment of the rifle stock kit is configured to work with a SKS type rifle.
The chassis system provided for herein consists of a body portion, top portion and a buttstock portion. The body portion is configured to receive the barreled action of an SKS type rifle. The body portion provides for a pistol grip and trigger that are located in front of the firearm's action and the firearm's magazine. Provided on the pistol grip is a mechanical safety which must be disengaged in order to operate the trigger. The trigger is provided with a mechanical link which extends therefrom back to the action of the SKS, placing the two into operational communication.
Located on the bottom portion of the chassis in front of the trigger is a handguard which is grasped by a users support hand during operation of the firearm. The handguard is rotatable and may be used as a foregrip, sometime referred to as a vertical foregrip.
Located adjacent to the magazine catch present on the action of the SKS is a magazine release lever. The magazine release lever is secured to the bottom portion of the chassis and provides two contact surfaces. By operating either contact surface the magazine may be quickly released.
These together with other improvements and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being made to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed to be characteristic of the invention, together with further advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which a preferred embodiment of the present invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.
FIG. 1 is a side perspective view of one side of a SKS type rifle's barreled action equipped with a bullpup stock kit in accordance with the present invention.
FIG. 2 is a side perspective view of another side of the SKS type rifle shown in FIG. 1 .
FIG. 3 is an exploded perspective view of the bullpup stock kit assembly including the bottom, top and buttstock portions of the chassis assembly; the linking mechanism of the trigger and the barreled action of an SKS type rifle are also shown.
FIG. 4 is a side perspective view of the body portion of the bullpup stock kit's chassis in accordance with the present invention.
FIG. 5 is a top view of the body portion of the chassis shown in FIG. 4 .
FIG. 6 is a top perspective view of the body portion of the chassis shown in FIG. 4 .
FIG. 7 is an enlarged partial view of FIG. 6 showing how the handguard cap adaptor is received within the body portion of the chassis.
FIG. 8 is a side perspective view of the handguard cap adaptor in accordance with the present invention.
FIG. 9 is a side view of the handguard cap adaptor shown in FIG. 8 .
FIG. 10 shows a side perspective view of the chassis's top portion in accordance with the present invention.
FIG. 11 is a side view of the chassis buttstock portion in accordance with the present invention.
FIG. 12 is a side perspective view of the buttstock shown in FIG. 11 .
FIG. 13 is an exploded side view of the body portion showing the rotatable handguard, trigger, trigger safety and magazine release in accordance with the present invention.
FIG. 14 is an exploded side view of another side of the body portion shown in FIG. 13 .
FIG. 15 is a side view of the bullpup shown in FIG. 1 .
FIG. 16 is a side cutaway view of the rifle shown in FIG. 15 , in particular the first position of the trigger safety is shown.
FIG. 17 is a partial cutaway view of the rifle shown in FIG. 15 , in particular the second position of the trigger safety is shown.
FIG. 18 is a side perspective view of the barreled action 11 used with the preferred embodiment of the invention shown in FIG. 1 , also shown is the trigger and trigger link.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
The present invention is directed towards a rifle stock kit that may be used to convert a traditionally configured rifle into bullpup configuration. The rifle stock kit also provides for an integrated rotatable handguard that may be used as a vertical foregrip, a trigger safety and a magazine release. As used herein, the phrases rifle stock kit and bullpup stock kit are used interchangeably.
It is to be understood that the term “action” as used throughout this specification includes the bolt, receiver and trigger mechanism of the firearm used with the preferred embodiment of the present invention. The firearm used with the preferred embodiment is a Samozaryadnyj Karabin sistemy Simonova rifle, commonly referred to as an SKS. The SKS is typically chambered to fire 7.62×39 mm ammunition.
Turning now to the drawings in which like reference characters indicate corresponding elements throughout the several views, as used herein, the word “front” or “forward” corresponds to where the muzzle end of the barrel is located (i.e., to the right as shown in FIGS. 1 , 3 and 15 - 17 ); “rear” or “rearward” or “back” corresponds to the direction opposite where the muzzle end of the barrel is located (i.e., to the left as shown in FIGS. 1 , 3 and 15 - 17 ).
As shown in FIGS. 1-2 and 15 , the present invention is directed to a bullpup stock kit, generally designated by reference numeral 20 , for use with the barreled action 11 of an SKS type rifle. The combination of the barreled action 11 and the bullpup stock kit 20 is referred to as the bullpup configured rifle, or simply bullpup, and is designated by reference number 10 .
Best shown in the exploded view of FIG. 3 , the bullpup stock kit 20 generally consists of a top portion 26 , a body portion 24 , a buttstock portion 28 , a trigger 30 , trigger safety 32 , a trigger link 34 and a magazine release lever 60 . The combination of the body portion 24 , top portion 26 and buttstock portion 28 are collectively referred to herein as the chassis 22 . Also shown in FIG. 3 is a detailed view of an SKS rifles barreled action 11 . The barreled action 11 is comprised of an action 18 (receiver and bolt), barrel 14 , handguard cap 17 and gas tube 16 . The action 18 also has a trigger 13 , a sear 15 , a hammer 19 , and a magazine release 5 . The magazine release 5 is sometimes referred to herein as a magazine catch.
A perspective side view of the chassis's 22 body portion 24 is shown in FIG. 4 . The chassis 22 is configured to receive the barreled action 11 in a channel 23 which extends between the back of the body portion 24 to its front. The channel 23 defines an interior bottom portion 40 with two side walls 41 A and 41 B extending therefrom. Side walls 41 A and 41 B generally occupy parallel plans.
Extending from the bottom side of the body portion 24 is a pistol grip 25 and a trigger guard 27 . The pistol grip 25 and trigger guard 27 are connected together. Located on the front end of the body portion 24 is a joint 29 to which the handguard 21 is mounted as shown in FIGS. 1-3 and 15 - 17 . Located on the underside of the body portion 24 near the back end is an opening 61 configured to receive the magazine release 60 lever therein (see FIGS. 1-3 ). Located adjacent to and connected with the opening 61 for the magazine release lever 60 is an opening 64 configured to receive a portion of the ammunition magazine 12 therein (see FIG. 5 ). The opening 64 is often referred to as a magazine well. Located adjacent the rear most end of the body portion 24 is a thru-bore 42 . The function of which will be described in greater detail in the following paragraphs.
Located on each side wall 41 A and 41 B, above the trigger guard 27 , are two thru-bores 43 . The thru-bores 43 located on side wall 41 A are in alignment with the thru-bores 43 present on side wall 41 B. Located between the thru-bores 43 within the interior of the body portion 24 is a pocket 44 (see FIGS. 4-7 ). The pocket 44 is configured to receive the handguard cap adaptor 70 described below (see FIGS. 6-9 ).
The handguard cap adaptor 70 has a protruding lip 71 on its front end constructed to be received by a portion of the handguard cap 17 (see FIGS. 16-17 ). It has an interior channel 72 configured to receive a portion of the barrel 14 therein when the barreled action 11 is secured within the body portion 24 of the chassis 22 . Four openings 73 through the top portion of the handguard cap adaptors' 70 body are provided (see FIGS. 7-9 ). There are two openings 73 on each side of the handguard cap adaptor 70 , each opening 73 being in alignment with an opening 73 located on the opposite side of the handguard cap adaptor 70 . When the handguard cap adaptor 70 is placed within the pocket 44 , the openings 73 are aligned with the thru-bores 42 of the body portion 24 of the chassis 22 (see FIG. 7 ). Once the openings 73 are in alignment with the thru-bores 42 , two roll pins 45 (see FIGS. 2-3 ) are used to secure the handguard cap adaptor 70 to the body portion 24 of the chassis 22 . Alternatively, a screw or friction pin may be used without departing from the scope of the present invention.
When the barreled action 11 is secured within the channel of the body portion 24 , a portion of the handguard cap 18 receives therein the protruding lip 71 of the handguard cap adaptor 70 (see FIGS. 16-17 ).
The pocket 44 is constructed to receive handguard cap adaptors 70 of varying size (see FIGS. 4-7 ). This is useful because the exact location of the handguard cap 17 on the gas tube 16 as it relates to the action 18 of the firearm varies based on the SKS rifles nation of origin. The overall length of the handguard cap adaptor 70 or the protruding lip 71 may be varied to accommodate the dimensional variations which exist between SKS type rifles manufactured at different arsenals.
FIG. 10 shows a side perspective view of the chassis 22 top portion 26 . The top portion 26 has an ejection port opening 80 which allows the user to operate the action 18 of the bullpup 10 and facilitates the ejection of spent ammunition cases during firing (see FIGS. 1 , 3 , 10 and 15 ). Located on its forward most end is a protruding lip 81 . The protruding lip 81 has a generally “U” shape, similar to the protruding lip 71 of the handguard cap adaptor 70 .
The top portion 26 defines an interior opening 82 configured to fit around a portion of the barreled action 11 . Two side walls 83 A and 83 B are provided on the back end of the top portion 26 . Each side wall 83 A and 83 B defines an opening 84 therethrough which is in alignment with an opening 84 in the other side wall 83 A and 83 B.
The top side of the chassis's 22 top portion 26 includes an elevated mounting platform 85 ( FIG. 10 ). Secured to the elevated mounting platform 85 is a rail segment 89 (see FIGS. 1-3 and 15 - 17 ). The rail segment 80 includes a number of rails extending therealong separated by traverse grooves 88 therebetween (see FIGS. 3 and 15 ). In the illustrated embodiment, the rail segment 89 of the elevated mounting platform 85 is manufactured in accordance with the MIL-STD-1913 rail specifications. The rail segment 89 facilitates the attachment of iron sights and/or optical gun sights based on user preference. Other attachment surfaces which facilitate the attachment of optics and iron sights could be used in place of the rail segment 89 shown and described herein. In the preferred embodiment, the rail segment 89 is secured to the elevated mounting platform 85 through the use of screws.
FIGS. 11 and 12 show detailed illustrations of the chassis's 22 buttstock portion 28 . The back side 90 defines thereon a textured surface which prevents the bullpup 10 from slipping off of the users shoulder during firing. Extending from the back side 90 of the buttstock portion 28 are two arms 91 A and 91 B. Each of the arms 91 A and 92 B are configured to interface with the body portion 24 and top portion 26 of the chassis 22 . Near the proximal end of each arm 91 A and 91 B is an opening 92 A and 92 B, respectively. Also provided on the buttstock portion 28 is a thru-bore 94 , the purpose of which will be later described in detail.
The arms 91 A and 92 B are constructed to be received within an interior opening which is present after the body portion 24 and the top portion 26 of the chassis 22 are attached to the barreled action 11 during assembly.
FIGS. 13 and 14 show exploded views of the body portion's rotatable handguard 21 . The joint 29 has an opening 95 therethrough configured to receive a pin 93 (FIGS. 4 and 13 - 14 ). The opening 95 has an eight side star-shaped opening on one end which has tapered interior side walls and a generally circular opening on the other end. The pin 93 has a head 96 portion, a threaded portion 102 and a cylindrical body portion extending therebetween. The preferred embodiment pin 93 is a shoulder bolt. Also provided are a coil type spring 97 , a star-shaped locking piece 110 having a threaded interior opening and tapered exterior side walls and an end button 98 having a centrally located opening therethrough.
The rotatable handguard 21 is configured to be grasped by the user during use of the bullpup 10 . The preferred embodiment handguard 21 is also constructed so that it may be rotated and used as a vertical foregrip. Located on its forward end is an opening 99 which extends through sides walls 105 A and 105 B. The portion of opening 99 on side wall 105 B has the general shape of an eight point star, the interior side walls of which are tapered. The portion of opening 99 on side wall 105 A is generally circular (see FIGS. 13 and 14 ). The handguard 21 defines an interior 100 area configured to be received against the body portion 24 when in the closed position (see FIGS. 1-4 ).
To attach the handguard 21 to the body portion 24 , the gap 101 of the handguard 21 located generally between side walls 105 A and 105 B is placed about the joint 29 of the body portion 24 . When the joint 29 is within the gap 101 , opening 95 and opening 99 are in alignment with each other. The spring 97 and end button 98 are then placed within the circular portion of opening 99 . The star-shaped locking piece 110 is inserted into the star-shaped portions of opening 99 and 95 , respectively. The pin 93 is then inserted through the aligned openings 95 and 99 and threadedly secured to the star-shaped locking piece 110 (see FIGS. 13 and 14 ). The end button 98 holds the spring 97 in place when the pin 93 is threadedly secured to the star-shaped locking piece 110 .
The star-shaped locking piece 110 secures the handguard 21 against unintentional movement when it is seated within opening 95 and 99 . The foregrip 21 may be disassembled by reversing the above outlined steps.
By varying the shape of the locking piece 110 and the appropriate portions of openings 95 and 99 , the number of positions into which the handguard 21 may be moved can be varied. The preferred embodiment of the handguard is provided with at least three positions of use.
The foregrip 21 may be placed in a closed position, also referred to as a first position, as shown in FIGS. 1-4 . In its closed position, the rotatable handguard 21 acts as a conventional handguard. Alternatively, the handguard 21 may be rotated to a second or third position where is acts as a foregrip. The second position places the length of the handguard at an approximate 45 degree angle as it relates to the longitudinal axis of the body portion 24 of the chassis 22 . The third position places the handguard 21 into a vertical position where it is at an approximately 90 degree angle in relationship to the chassis's 22 body portion 24 (see FIGS. 15-17 ).
The rotatable handguard 21 is moved between positions by pressing side wall 105 A towards the body portion 24 . This action compresses spring 97 and causes the star-shaped locking piece 110 of pin 93 to be pushed out of engagement with the star-shaped portion of opening 95 . The handguard 21 is the free to rotate to the next provided position at which time the pressure being placed on side wall 105 A is released. Once pressure is release from side wall 105 A the star-shaped locking piece 110 is received within another portion of the star-shaped portion of opening 95 . Once the star-shaped locking piece 110 has been received within the star-shaped portion of opening 95 the handguard is secured against unintentional movement.
The trigger 30 and trigger safety 32 provided by the bullpup stock kit 20 are mounted to the body portion 24 of the chassis 24 (see FIGS. 1-3 ). The trigger 30 has two thru-bores 31 A and 31 B there through and defines a contact surface 46 thereon (see FIGS. 13-14 ). The trigger safety 32 has one thru-bore 39 there through and defines a contact surface 47 thereon (see FIGS. 13-14 ). The contact surfaces 46 and 47 of the trigger 30 and trigger safety 32 , respectively, are preferably textured.
The body portion 24 of the chassis 22 provides two openings 35 and 36 therethrough for mounting the trigger 30 and trigger safety 35 , respectively (see FIGS. 1-5 and 13 - 14 ). Opening 36 also passes through the structure 37 , or mounting position, provided within the interior channel 23 of the body portion 24 . The provided structure 37 is constructed to receive the trigger therein and minimize its side to side movement during operation (see FIGS. 5 and 7 ).
The pistol grip 25 portion of the chassis 22 has a hollow 38 therein configured to receive the trigger safety 32 , trigger safety spring 33 , and a portion of the trigger 30 (see FIGS. 4-5 and 16 - 17 ). The trigger safety 32 has a first position of operation shown in FIG. 16 and a second position of operation shown in FIG. 17 .
The spring 33 biases the trigger safety 32 into the first position. The first position of the trigger safety 32 has the safety sear 48 engaged with a rearwardly protruding member 49 of the trigger 30 . This engagement between the safety sear 48 and protruding member 49 prevents the rearward movement of the trigger 30 (see FIG. 16 ).
When the contact surface 47 of the trigger safety 32 is depressed towards the back side of the pistol grip 25 , the safety sear 48 is rotated out of engagement with the protruding member 49 of the trigger 30 . This is called the second position of the trigger safety 32 (see FIG. 17 ). In this position, if the trigger 30 contact surface 47 is acted on by the user, the trigger 30 will move towards the rear allowing the bullpup 10 to be fired.
Another portion of the bullpup stock kit 20 is the magazine release lever 60 (see FIGS. 1-3 and 15 - 17 ). The magazine release lever 60 has a thru-bore 50 located near its approximate center. Located on its forward face, near its top, is a textured contact surface 63 . Located adjacent its bottom surface is another contact surface 65 . Located opposite the contact surface 63 on the forward face of the magazine release lever 60 is the engagement surface 66 (see FIGS. 16-17 ).
When the magazine release lever 60 is attached to the body portion 24 of the chassis 22 , the engagement surface 66 is in contact with the magazine release 5 of the action 18 . When the contact surface 63 of the magazine release lever is depressed, the engagement surface 66 pushes the magazine release 5 of the action 18 towards the rear of the rifle 10 allowing the magazine 12 to be removed.
Alternatively, the user may push the contact surface 65 provided on the bottom of the magazine release lever 60 forward. This motion causes the engagement surface 66 of the magazine release lever 60 to push the magazine release 5 of the action 18 towards the rear. The magazine 12 may be removed from the bullpup 12 once the magazine release 5 has been moved sufficiently towards the rear.
The magazine 12 is secured within the magazine well of the chassis 22 , to the barreled action 11 in a manner well known throughout the prior art as it concerns SKS type firearms. In alternate embodiments of the bullpup stock kit 20 , the method of securing a magazine into place will vary according to the barreled action used.
The magazine release lever 60 is secured to the body portion 24 of the chassis 22 as follows. The magazine release lever 60 is inserted into the opening 61 provided in the body portion 24 . The thru-bore 50 of the magazine release lever 60 is aligned with the opening 62 provided on the body portion 24 of the chassis 22 . When the thru-bore 50 is aligned with the opening 62 , a friction pin is inserted through the aligned openings thereby securing the magazine release lever 60 in place. The friction pin provides a surface about which the magazine release lever 60 rotates.
FIG. 18 shows a view of the barrelled action 11 used with the preferred embodiment of the herein described invention. Also shown is the trigger 30 , trigger link 34 and the sear engagement member 52 .
When a barreled action 11 has been mounted in the chassis 22 of the present invention, a trigger link 34 extends between the trigger 30 provided for herein and the trigger 13 of the host firearms action 18 (see FIG. 18 ). At its forward end, the trigger link 34 has a bend 51 which is received within a thru-bore 31 A of the trigger 30 (see FIGS. 13-14 and 18 ). The trigger link 34 extends rearwardly from the trigger 30 towards the host firearms action 18 . The rearward end of the trigger link 34 is received within a thru-bore 54 located at one end of a sear engagement member 52 , or engagement member. When assembled therewith, the engagement member 52 extends perpendicular to the longitudinal axis of trigger link's 34 rearward end. The engagement member 52 has a generally cylindrical shape, the exterior surface of which has a plurality of flat surfaces 53 thereon (see FIG. 18 ).
The engagement member 52 is secured to the trigger link 34 through the use of a set screw (not shown). A bore (not shown) is off set from the thru-bore 54 and threaded. This threaded bore receives a set screw which when tighten into place comes into direct contact with the trigger link 34 . While the set screw is in contact with the trigger link 34 the engagement member 52 is unable to move. This method of assembly allows for the precise placement of the engagement member 52 during installation.
The bullpup stock kit 20 is installed on a barrelled action as follows. Initially the handguard cap adaptor 70 and the magazine release lever 60 are installed on the body portion 24 of the chassis 22 as described above. Then the spring 33 and trigger safety 32 are inserted within the hollow 38 of the pistol grip 25 (see FIGS. 16-17 ). The thru-bore 39 of the trigger safety 32 is aligned with opening 36 of the body portion 24 . A friction pin is used to secure the trigger safety 32 and spring 33 into place within the hollow 38 of the body portion 24 .
The bend 51 of the trigger link 34 is now inserted into thru-bore 31 A of the trigger 30 . The trigger 30 is then inserted into the opening formed between the two walls which define its mounting position 37 within the body portion 24 of the chassis (see FIG. 5 ). The trigger 30 is secured in place through the use of a roll pin which is inserted through opening 35 of the body portion and opening 31 B of the trigger 30 (see FIGS. 1-2 and 15 ).
Next, the barreled action 11 is positioned above the body portion 24 of the chassis 22 . Then the sear engagement member 52 is installed on the trigger link 34 as described above (see FIG. 18 ). The engagement member 60 is positioned on the trigger link 34 so that a portion of its exterior 53 is positioned behind the sear 15 of the action 18 when inserted therein. While the engagement member 60 is so positioned, the length of the trigger link 34 runs parallel to the longitudinal axis of the barreled action 11 .
The barreled action 11 is then inserted into the channel 23 of the body portion 22 so that the protruding lip 71 of the handguard cap adaptor 70 is received within the lower portion of the handguard cap 17 (see FIGS. 16-17 ). Next, the top portion of the chassis 22 is placed over the top of the barreled action 11 . The top portion 26 is positioned so that the protruding lip 81 on its front end is received within a portion of the handguard cap 17 (see FIGS. 1-2 and 15 - 17 ). The action 18 is received within the interior opening 82 of the top portion 26 . The arms 91 A and 91 B of the buttstock portion 28 are inserted into the opening formed between the top portion 26 and the body portion 24 . When properly installed, openings 92 A and 92 B of the buttstock portion 28 are in alignment with opening 84 of the top portion 26 . A pin is inserted through these aligned openings to secure the buttstock portion 28 to the top portion 26 . Concurrently, the thru-bore 94 of the buttstock portion 28 is also in alignment with the thru-bore 42 of the body portion 24 . A screw or friction pin is then inserted into the aligned thru-bores 42 and 94 , effectively securing the buttstock portion 28 to the body portion 24 .
To remove the bullpup stock kit 20 described above, simply reverse the above outlined steps.
When the trigger 30 is pulled to the rear the trigger link 34 is pulled forward. The forward movement of the trigger link 34 causes the engagement member 54 is push against the back side of the sear 15 of the action 18 . Once sufficient pressure has been applied to the sear 15 , the hammer 19 is released allowing the bullpup 10 to fire in a manner well know throughout the prior art.
Use of the magazine releaser lever 60 has been described in detail above.
The magazine release lever 60 , trigger 30 , trigger safety 32 , handguard 21 and the body portion 24 , buttstock portion 28 and top portion 26 of the chassis 22 are manufactured from nylon sixty six. While nylon sixty six is the preferred material, any material suitable for use with firearms may be substituted. All of these components are preferably manufactured through an injection molding process.
The exact shape and textures of the chassis's 22 exterior surfaces may be varied without departing from the scope of the invention disclosed herein.
In an alternate embodiment, the rotatable handguard 21 could be omitted entirely without departing from the scope of the present invention. In lieu of the rotatable handguard 21 , a non-moving handguard or a fixed position vertical foregrip could replace it.
In still another alternate embodiment, iron sights could be provided as part of the top portion 26 of the chassis 22 without departing from the scope of the present invention.
The foregoing descriptions and drawings should be considered as illustrative only of the general principles of the invention. This invention is not limited for use with the barreled actions of SKS types rifles; rather it may be used with any rifles barreled action which has a similar sear 15 mechanism. Numerous applications of the present invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
|
The present invention provides for a stock kit that converts a conventional rifle, such as an SKS, into bullpup configuration. The preferred embodiment of the provided stock kit does not require any permanent modification be made to the host firearm.
| 5
|
BACKGROUND OF THE INVENTION
This invention relates to resectoscopes and more particularly to an improved resectoscope and a novel cutting electrode for use with it.
Resectoscopes are surgical endoscopes for transurethral resection of the prostate gland or bladder growths and for the coagulation of bleeding vessels in the area of the prostate and bladder. The basic components of a resectoscope are a telescope, a working element assembly, a cutting electrode and a sheath. The sheath portion of the instrument is inserted in the urethra using an obturator which is then removed from it in order that the stem portion of the working element assembly with the telescope and cutting electrode can be mounted in the sheath. The telescope, typically about 4 mm. in diameter and about a foot long, lies in a snug yet slidable relationship in a channel in the stem portion of the working element assembly. It has a viewing system with an eyepiece at its proximal end and an objective lens at its distal end as well as means, such as a bundle of light carrying fibers or an incandescent lamp, for illuminating the telescope's field of view. The cutting electrode (typically formed of insulated tungsten wire between about 0.010 to 0.018 inches in diameter) is also carried by the working element assembly inside the sheath and has an uninsulated or bare arcuate cutting loop portion which is reciprocated forward and back through the sheath's fenestra in front of and within the field of view of the telescope.
The mechanical arrangement for reciprocating the electrode varies in different resectoscopes and forms no part of the present invention. Some instruments use a rack and pinion, others a spring and thumb control, while others use a fixed thumb position and move the electrode with the fingers via a movable block in the working element assembly. Cutting is accomplished by reciprocating the electrode while applying electrical high frequency currents to the electrode at voltages of between about 250 volts to about 4,000 volts or more at frequencies of from about 0.4MHz to about 3MHz. To facilitate clearing the telescope's field of view of the blood and other debris which tend to obstruct the doctor's view during resection, clear irrigation fluid is typically passed through the sheath and in front of the telescope's objective lens. In some resectoscopes a drain is also provided to allow continuous irrigation fluid flow through the sheath both in and out of the bladder.
Heretofore, insulation breakdown and capacitive coupling in resectoscopes in which the electrode is operated at the above indicated voltages and frequencies, has often caused accidental electrical burns to the doctor using the instrument and to the patient in whom the instrument is being used. Further, without an expensive stabilizer structure, prior art cutting electrodes used in such instruments lack adequate rigidity against upward and lateral deflection created by forces to which the electrode is subjected during resection. Without adequate rigidity, the extended electrode may be deflected out of the field of view, and the retracting electrode can be pushed out of alignment with the sheath, frequently contacting and burning the sheath's lower lip or causing electrical arcing between the electrode and the telescope. This often results in expensive damage to the latter and can cause termination of the surgical procedure. In addition, with prior art resectoscopes, the field of view is too often obscured by bubbles, blood and other debris which is not swept away by adequate irrigation flow, thus making uninterrupted operation of the instrument difficult.
One object of the invention, therefore, is to provide a new resectoscope which has substantially higher electrical safety than prior art devices and hence is less likely to cause accidental burns to either doctor or patient.
Another object is to provide a resectoscope with a high flow capacity continuous irrigation system which maintains a clearer visual field in front of the telescope and permits longer periods of uninterrupted operation of the instrument than heretofore.
Still another object is to provide a simple novel cutting electrode for use in the improved resectoscope.
A further object is to provide a novel resectoscope in which the cutting electrode loop is more adequately stabilized and supported in its path of travel than in prior art devices.
A still further object is to provide a novel resectoscope which maximizes the space inside the sheath available for irrigation fluid flow.
Yet another object is to provide a resectoscope in which: (a) the telescope is more effectively insulated from the ground or patient plate potential; (b) the size and number of exterior electrically conductive parts of the resectoscope are minimized; and (c) the capacitive coupling of these parts to the active conductors is reduced.
Further, other and additional objects and advantages of the invention will become apparent from the summary and detailed description of the invention which follow, as well as from the drawings and the appended claims.
Summary Of The Invention
In one aspect, the invention comprises a working element assembly for use in a resectoscope having a sheath, said assembly including a stem portion for insertion within the sheath, and having a telescope channel member with a central axis and a pair of parallel cutting electrode guide channel members spaced apart and sealingly mounted along the length of the telescope channel member on opposite sides thereof above its central axis. In the preferred embodiment, the telescope channel member and electrode guide channel members are integral with each other so no fluid can pass between them and the radial peripheries of the guide channel members sealingly engage the sheath wall in a snug yet slidable relationship so the stem alone divides the space inside the sheath into a space above and a space below the electrode guide channel members and no fluid will pass by them from one space to the other. The irrigation fluid conduits are formed between the stem and the sheath with the drainage conduit being defined by either the upper or the lower of these two spaces. The irrigation fluid inflow conduit, naturally, is defined by the one of these two spaces not used as the drainage conduit.
In a second embodiment, the radial peripheries of the cutting electrode guide channel members do not engage the interior wall of the sheath. Instead, the working element stem includes a cover which fits snugly and fixedly over and against the peripheries of these members. This cover also engages the sheath in a snug but slidable relationship to allow the stem to be inserted into and removed from the sheath. In this embodiment, the space between the cover, the electrode guide channel members and the upper portion of the telescope channel member defines a conduit between them which can be used for irrigation fluid drainage or inflow purposes.
In a third embodiment, the working element stem includes a complete conduit mounted on top of the telescope channel and between guide channel members of the stem. In this third embodiment, the interior area of this conduit, which also can be used as an irrigation fluid drain or inflow conduit, is somewhat reduced, due to the thickness of the material forming it. There is only a single thickness of such material in the second embodiment due to the cover itself and no conduit forming material between the stem and the sheath in the preferred embodiment. The preferred embodiment, therefore, maximizes the cross sectional area between the sheath and the working element stem available for bringing in and draining the irrigation fluid.
Another advantage of the preferred embodiment is that the upper conduit, formed between the stem and the sheath, is cleaned more easily (when the stem and the sheath are separated) than when the stem is covered or a fully enclosed conduit is provided.
In another aspect, the invention comprises terminating the lower portion of the working element stem at a point within the sheath while extending its upper portion (including the upper portion of the electrode guide channel members and the upper portion of the telescope channel member between them), forwardly within the sheath. This upper portion of the stem comprises a roof which is extended in the forward direction a distance through the sheath above the sheath's window or fenestra through which the cutting electrode does its cutting. This extension serves two functions and provides two fundamental advantages. First, it moves the irrigation fluid conduit above the telescope to a point in front of and above the distal end of the telescope. When used as a drainage conduit, this helps create and maintain a flow of fresh clear irrigation fluid through the telescope's field of view to keep it clear for easy viewing of the area of interest to the doctor. Secondly, by extending part of the cutting electrode channel members to a point forward of the telescope's objective lens, a rigid non-moving support is provided for holding the cutting electrode against upward and lateral movement throughout at least a portion of its path of travel forward and back in front of the telescope.
Still another aspect of the invention comprises providing a simple cutting electrode for use with the improved resectoscope. The electrode comprises a single length of electrically conducting wire (preferably tungsten) having a conventional exposed arcuate cutting loop portion in the middle of the wire and two novel substantially straight flexible parallel spaced apart arms covered with insulation and extending rearwardly from the loop in the same direction throughout the remaining length of the electrode. Each arm terminates in a free end portion which preferably includes a quick disconnect male electrical terminal. The insulation covering the wire is preferably made from a known fluorocarbon resin (comprising a group of synthetic resins based on tetrafluoroethylene polymers) which is available from Dupont De Nemours & Company under the trademark Teflon-FEP. The insulation encapsulates the wire arms with a thickness of preferably at least about 0.015 inches. The preferred embodiment of the electrode according to the invention also includes a stiffened wire portion on each arm extending rearwardly from the loop portion of the electrode a distance longer than the electrode's length of travel when reciprocated forward and back its full distance in the instrument. The addition of such a feature helps ensure rigidity of the loop portion of the electrode when it is reciprocated beyond the roof portion of the working element stem and pressure is exerted against the loop in the lateral or vertical directions.
A further aspect of the invention includes forming the moving block portion of the working element assembly and other exterior and interior parts of the instrument from a known physically strong dielectric material such as acetal resin. This material is available from the DuPont de Nemours & Company under the trade-mark DELRIN. Upwardly sloping channels are formed in the moving block for the free ends of the electrode arms to keep the electrical connections of the arms far enough away from the telescope shaft, which is made of metal, to reduce the risk of dielectric breakdown in the block. In addition, to the extent possible all other parts of the resectoscope which are exposed to contact by the doctor or patient are formed of dielectric material. Necessary external parts which are capable of conducting electricity have a minimum of conductive interconnections and are made as small as possible. Further, they are preferably spaced as far as practicable from the active conductors to reduce the capacitive coupling to such conductors to below about 4 pico farads and preferably below about 2 pico farads. The ohmic coupling of these parts should be minimized by maintaining the resistance between them and the active conductors at a level of not less than about 25,000 ohms. As far as possible, the metal shaft of the telescope is isolated from all conducting materials which assume a ground or patient plate potential. Hence, the telescope can assume high voltage without a substantial flow of current to the telescope shaft which can damage it severely.
A still further aspect of the invention includes providing one or more feet on the exterior of the telescope channel portion of the stem spaced a distance rearwardly from the distal end of its bottom portion. This foot or feet serve to support the distal end of the stem from the bottom of the sheath. In the preferred embodiment, this helps maintain portions of the cutting electrode guide channel members of the stem tightly sealed against the sheath to minimize or prevent irrigation fluid leakage between the irrigation fluid supply and drainage conduits. The foot or feet also space the bottom portion of the stem far enough away from the sheath to allow the fluid to flow past the distal end of the telescope smoothly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the preferred embodiment of a resectoscope according to the invention.
FIG. 2 is a perspective view of from underneath, partially cut away, of the distal end portion of the embodiment of FIG. 1.
FIG. 3 is a perspective view of the preferred embodiment of a cutting electrode according to the invention.
FIG. 4 is a vertical elevation view of the embodiment of FIG. 1 with a portion of the sheath cut away to show a supporting foot on the bottom of the working element stem.
FIG. 5 is a vertical elevation view of the working element assembly of FIG. 1.
FIG. 6 is a plan view in elevation of a portion of the embodiment of FIG. 1.
FIG. 7 is a cross sectional view of the preferred embodiment of the invention taken along lines 7--7 of FIG. 2.
FIG. 8 is a vertical cross section view in elevation of the distal end of the preferred embodiment of the resectoscope, taken along line 8--8 of FIG. 6.
FIG. 9 is a vertical elevation view of the main sections of the working element assembly and sheath portions of the embodiment of FIG. 1, shown partially cut away and partially in section to illustrate the irrigation fluid inflow and drainage conduit connections.
FIG. 10 is a profile view in vertical elevation of the moving block portion of the working element assembly taken along lines 10--10 of FIG. 9 with the electrical connection mechanism inside it partially shown in phantom.
FIG. 11 is a cross sectional vertical elevation view of the second embodiment of the working element stem portion of a resectoscope according to the invention taken through the middle of the sheath and showing a cover over the cutting electrode guide channel members.
FIG. 12 is a vertical cross sectional elevation view similar to that of FIG. 11, showing a third embodiment of the working element stem portion of a resectoscope according to the invention in which the irrigation fluid drain conduit defines a tube mounted on the upper surface of the telescope channel member between the cutting electrode guide channel members.
FIG. 13 is a vertical elevation view of a second embodiment of a cutting electrode according to the invention.
FIG. 14 is a blow up vertical elevation view in partial cross section illustrating the quick release electrical connections in the moving block for the male terminals on the free ends of the electrode arms.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1 through 5 & 7-9 of the drawings, the preferred embodiment of a resectoscope according to the invention includes a telescope 10, having an eyepiece 11, an insulated tungsten cutting electrode 12, a working element assembly 14 and a dielectric sheath 16 made of conventional known material. The distal, or forward, end 18 of the sheath has its lower portion cut away to form a window or fenestra 20 through which the doctor views the area of interest and through which the electrode 12 operates. The sheath above the fenestra holds tissue above that portion from falling into the field of view or against the electrode. The proximal, or rearward, end 17 (FIG. 9) of the sheath 16 is mounted in the dielectric female cone block 22 which carries a conventional sheath locking mechanism 24 for connecting the sheath to the working element assembly portion 14 of the resectoscope.
The working element assembly 14 includes a stainless steel thin wall stem 26, a dielectric cone portion 28, a movable dielectric block 30, a dielectric end block 32, a pair of metal rails covered with insulation 34 and a curved dielectric bridge 36. The rails 34 are spaced apart and rigidly connect the block 32 to the cone portion 28. The bridge 36 forms an upwardly facing trough betwen the rails 34 and likewise connects the cone portion 28 with the end block. The movable block 30 contains openings through it enabling the block to slide back and forth over the rails and bridge. The movable block 30 & end block 32 also include channels 38 & 40 (FIGS. 10 & 4) respectively through which the telescope 10 is inserted over the bridge 36 into the working element stem portion of the instrument. A similar channel for the telescope through the cone portion 28 is not shown.
The stem portion 26 of the working element assembly is mounted in the cone 28 by a metal collar 42 and includes tubular cutting electrode channel members 46 sealingly mounted on a tubular telescope channel 44 member along its length. Preferably the guide channel members 46 are soldered or otherwise mounted on opposite sides of the upper portion of the stem and form what look like mouse ears on the stem when seen in cross section, (FIG. 7). Further, as best seen in FIGS. 2, 5 & 8, the lower portion of the distal end 48 of the stem 26 is cut away leaving the upper portions of the guide channel members 46 and the upper portion of the telescope channel member 44 between them defining a cantilevered roof 50. The guide channel member portions of this roof seal against both the sheath and the telescope channel member and project forward of the distal end of the telescope. A pair of openings 51 are formed in the roof 50 adjacent the front end of the telescope 10. When the upper conduit is used for drainage of irrigation fluid this enables bubbles formed during operation of the instrument to be drawn into the drain conduit above the roof.
In addition, as seen in FIGS. 2 & 8, there is a member 53 mounted on the distal end of the roof 50. This member extends generally upwardly and is rounded to fit the curvature of but be spaced away from the upper inside wall of the sheath 16. Further, this member has a plurality of openings or slots 55 distributed over its surface so that irrigation fluid will flow into the conduit through at least some of these openings even if others become clogged by pieces of tissue during resection. The sheath 16 also preferably includes a plurality of openings 57 proximally adjacent the member 53 and above the roof 50 to facilitate drainage. The member 53 may be fixed to the roof as shown or formed from an extended portion of the roof and bent upwardly toward the sheath. This latter form may be preferable in certain circumstances.
On the bottom of the working element stem 26, within the sheath and spaced a distance rearwardly of the roof 50 is a metallic foot 52 which supports the distal or forward end of the stem upwardly in the sheath 16 to ensure a good seal between the guide channel members 46 of the stem and the sheath.
Referring now to FIGS. 1, 4 & 9, the female cone block 22 has curved portions 54 above and below the sheath 16. The block 22 includes a conical cavity 56 in which the cone portion 28 of the working element assembly 14 nests when the sheath 16 is connected to the assembly. The sheath connection locking mechanism 24 includes a dielectric U-shaped member 58 pivotally mounted about the ends of its arms 60 on opposite sides of the block 22 and has a pair of locking pawls 62 which engage a pair of projecting pins 64 on the distal ends of the rails 34 on opposite sides of the block 22 to hold the block and sheath on the working element assembly 14. Preferably, the U-shaped member 58 is spring biased downwardly by a spring to maintain a locking condition between the block and cone.
The preferred embodiment of the cutting electrode 12 includes a loop 68 at the distal end of the electrode and a pair of substantially parallel spaced apart arms 69 extending rearwardly from the loop in the same direction. The distal portions of these arms are reinforced to give added strength to the loop (if the wire is not sufficiently rigid). The reinforcement preferably comprises stiffening elements 70 such as metal sleeves which extend from the loop 68 rearwardly a distance which is greater than the length of travel of the electrode 12 when reciprocated back and forth in the instrument. Normally, this length is about 25 mm. or more. The entire electrode 12 from the ends of the loop 68 to the free ends 71 of the arms 69 is covered with a layer of electrical insulation material 73 at least about 0.015 inches thick to isolate the guide channel members 46 of the stem 26 from the electrode wire 72 itself when the electrode is inserted into these members. If desired the stiffening elements 70 may surround the insulation rather than lie beneath as shown in FIG. 3. Preferably, the free ends 71 of the arms 69 have snap-in quick release male terminals 74 connected to them for easy electrical connection with the release from the active wire 76 which feeds electrical power into the block 30.
Referring now to FIGS. 1, 10 & 14, an insulated active wire 76 enters the block 30 from the top and connects electrically to a downwardly spring biased electrode 78 which is slidable within a brass sleeve 79. The electrode has a pair of conducting pins 80 projecting downwardly into a pair of transverse channels 81 in the sleeve 79 for receiving the free ends 71 of the arms 69. The electrode also includes a sideway 84 which cooperates with a spring biased dielectric cam member 86 having a finger operated portion 88 extending outwardly of the block. In operation, when the finger operated portion 88 is pushed into the block against the force of its biasing spring 90 it moves through the slideway 84 and raises the electrode 78 against the force of its biasing spring 92 thus disengaging the pins 80 from the male terminals 74. When the finger operated portion 88 is released, the pins 80 descend again to their bottom position. In this position (shown in FIG. 14) they can be raised out of the way slightly on urging the male terminals into engaged position and will automatically snap back to engage the grooves 94 in these terminals when the electrode arms are fully seated in the block 30. The channels 81 in the block 30 are tapered slightly at the entrance to the block to facilitate insertion of the terminals and slope upwardly from this entrance as they penetrate the block away from the telescope 44. This causes the terminals 74 in the middle of the block to engage the pins 80 at a point above the telescope channel. As already indicated the terminals and contacting conductors should be at least about 0.03 inches away from this channel and preferably not less than about 0.06 inches from it.
When preparing the resectoscope for use, the cutting electrode 12 is inserted into the working element assembly 14 by placing the male terminal of each arm 69 in the front end of its guide channel member 46 and pushing the electrode rearwardly until the arms 69 emerge from the corresponding channels at the rear of the cone portion of the working element assembly. From there the arms 69 pass above the bridge over the telescope shaft 96 and into the channels 81 in the block 30. Terminals 74 then move upwardly and rearwardly finally becoming connected with the pins 80.
Though, preferably, the guide channel members 46 comprise tubes mounted on the telescope channel member 44, in resectoscopes in which the interior space within the sheath is not large enough to accommodate the wall thickness involved in such a structure, the telescope channel member and guide channel members may be formed from a single metal tube in which the guide channel members protrude radially from the telescope channel member and are open inwardly to it along their lengths.
Referring now to FIGS. 1 & 9, if desired the irrigation fluid may flow into the resectoscope through a conventional metal valve 98 in the upper portion of the finger grip block 22. From there it can flow through a channel 100 in the block into an annular groove 102 in the forward portion of the cone 28. From there it may pass through a radially inward opening 104 in the groove 102 and stem collar 42 forwardly between the sheath and the lower portion of the telescope channel 44 to the fenestra 20. A rectangular gasket 106 is provided around the stem 26 at the front of the cone 28 to form a seal between the sheath 16 and the collar 42. In the preferred embodiment, this gasket also seals against the guide channel members 46 of the stem 26 and in this way keeps the fluid below the guide channel portions 46 of the stem 26 separate from that above them. If desired, the draining fluid may pass rearwardly between the stem 26 and the collar 42 and then upwardly through a radially outwardly extending opening 108 in the collar 42 and cone 28 to an annular groove 110 in the cone. From there it may flow downwardly around the grove into a channel 112 in the lower portion of block 22 and out through a conventional metal valve 114.
The operation of the resectoscope according to the invention is conventional and in the preferred embodiment shown in the drawings uses a rack and pinion mechanism for moving the block 30 forward and back. A dielectric rack 130 is attached to the bottom of the bridge 36 and the pinion (not shown) is mounted on a dielectric shaft 132 through a horizontal opening through the block 30. A channel in the block (not shown) permits the block to move forwardly and back over the rack 130. A dielectric lever arm 134 is mounted on a dielectric knob 136 at one end of the shaft 132 (see FIG. 6) to rotate the shaft. The teeth on the rack and pinion mesh together so about a 180° turn of the shaft moves the block all the way forward or back. As the block moves, it drives the electrode arms 69 through the cone 28, block 22 and guide channels 46. The loop 68 is thereby moved forward and back along its path of travel in front of the telescope 10. The path of travel of the loop 68 extends from a couple of millimeters within the sheath to about 25 millimeters forwardly of the lower lip of the fenestra 20.
In the resectoscope according to the preferred embodiment of the invention, when the electrode 12 is in its forward position, its loop portion 68 is supported by its reinforced sections 70 in the guide channels 46 against lateral or upward movement. When in its rearward or retracted position, the loop portion 68 lies above the bottom portion of the sheath 16 and in front of the distal end of the telescope 10. It is also held in this position by the reinforced portions 70 of the electrode 12 in the guide channel members 46 so that the loop 68 will not contact the sheath 16 or the telescope 10. As indicated previously, the telescope shaft 96 is isolated electrically from all other conductive material at the ground or patient plate potential. Accordingly, even if it should be touched by the electrode the resulting effect would be minimal and no harm should be done to the telescope.
Referring now to FIG. 11 of the drawings, a second embodiment of the working element stem portion 26a of the resectoscope according to the invention will be described. The use of alphabetical letters in connection with numbers for certain parts in this specification and in the drawings is to identify the parts which are the same in each of the various different embodiments. The stem 26a includes a telescope channel member 44a and electrode guide channel members 46a as in the preferred embodiment but, instead of having these guide channel members seal directly against the sheath 16a, as in the preferred embodiment, a cover 138 is provided which seals against the guide channel members 46a on one side and nests snugly against the sheath 16a on the other. This cover 138 extends the length of the stem 26 including the portion of it forming the roof 50a. This cover includes at least one slot or other opening (not shown) adjacent the drainage openings 57 in the sheath (see FIGS. 2 & 8) to facilitate the passage of irrigation fluid into the drainage conduit. In all other respects this second stem embodiment is like that of the preferred embodiment.
Referring to FIG. 12, a third embodiment of a working element stem 26b according to the invention includes telescope channel and electrode guide channel members 44b and 46b respectively, but instead of a cover as in the second embodiment it includes an enclosed drainage conduit 140 which is mounted on the upper side of the stem 26b, nesting between the guide channel members 46b and fitting against the sheath 16b at its upper surface. In this embodiment as in the second, the guide channel members 46b of the stem do not sealingly engage the sheath 16b. Similarly, the conduit 140 extends the length of the stem including the roof portion 56b and has the same slots or other drainage openings (not shown) referred to above in connection with the second stem embodiment.
Turning finally to FIG. 13, a second embodiment of an electrode 12a according to the invention comprises the same electrode as the preferred embodiment, but without the reinforcement portion at the distal end of the electrode. Thus, it includes a loop 68a, arms 69a, wire 72a, insulation 73a and male terminals 74a at its free ends 71a.
While various embodiments of the invention have been described in the foregoing specification, it will be understood that various modifications may be made to these embodiments within the scope of the invention as defined by the appended claims.
|
The disclosed apparatus includes a resectoscope with a novel working element stem, a novel cutting electrode for use with the stem and novel electrical features including a dielectric moving block element for reciprocating the electrode. The stem portion of the working element has a telescope channel member with a central axis and a pair of cutting electrode guide channel members spaced apart and mounted on opposite sides of the telescope channel member above its central axis. The cutting electrode consists of a single length of electrically conductive wire with a loop portion in the middle of the wire and a pair of substantially straight, flexible, parallel, spaced apart insulation covered arms having similar lengths and extending rearwardly from the loop in the same direction. The arms of the electrode are inserted within the cutting electrode channel members in the working element stem. The size and number of electrically conductive exterior parts of the instrument are minimized and the capacitive and ohmic coupling of these parts to the active conductors is minimized to reduce the chance of accidental burns to the doctor or the patient.
| 0
|
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of U.S. patent application Ser. No. 367,010, filed on June 16, 1989.
FIELD OF THE INVENTION
This invention most generally relates to the field of protective garments that protect the user against insects. Most particularly this invention relates to an insect protective garment made entirely of a lightweight semi-rigid insect excluding mesh designed and fabricated in a manner which causes the garment to substantially "stand away" from the body of the wearer so as to obviate the need for a plurality of fabrics and the need for intermediate fabrics and/or devices to separate the mesh layer from the wearer's body.
DESCRIPTION OF THE PRIOR ART
Mosquitoes, black flies and other insects have long plagued gardeners, sportsmen, and anyone else who enjoys the outdoors. Various lotions and sprays have been developed to repel these insects but their success is limited, they present a possible health hazard, and even so do not remove the possibility of insects physically entering a person's eyes, ears, nose or mouth. An object of this invention is to provide a comfortable protective garment that protects the wearer from insects without the use of ineffective or potentially dangerous chemical products.
Protective clothing and protective garments are known in the prior art. Examples of protective garments in the prior art are disclosed in U.S. Pat. Nos. 3,783,451; 4,395,781; 4,422,184; 4,685,152; and 4,716,594. These patents are relevant to the applicants' invention in that they represent the closest prior art disclosing protective garments and the like. None of the above identified patents disclose a garment that is totally free from zippers, closures, face openings, spacers, multiple layers of mesh and/or fabrics of various types and other complicated and complicating elements or features. Moreover, these complicating features reduce the overall protective feature of the prior art garments. Another object of the instant invention is to provide an opening-free garment when on the wearer and which is simple and easy to put on and take off. A still further object of the invention is to provide an effective and yet low cost garment.
SUMMARY OF THE INVENTION
The present invention in it's most simple form or embodiment is directed to a garment to protect the user against mosquitoes, black flies and other insects. The garment is made entirely from a semi-rigid insect excluding but see-through mesh, so that it is comfortable during physical exertion or for use in warmer weather and preferably the mesh is also lightweight material. The mesh is a semi-rigid material such as, for example, the screening material commonly used in campers and tents. The garment is thus durable and suitable for people working or playing outdoors. This material makes a garment that allows the user freedom of movement because it is loose fitting, while at the same time being rigid enough to make the mesh stand away from body surfaces of the wearer without the need for any other devices. It is sufficiently loose enough to pass over normal outer garments of the wearer to completely enclose the body of the wearer and protect the wearer from the bother of insects.
The garment comprises a one-piece head net which fully encloses the wearer's head and jointed to the upper body portion at the neck. The one-piece fully encloseable head net is preferrably stiched to an upper body portion from about a right side shoulder seam to about a left side shoulder seam thereby forming a rear portion of a neckline. A means for opening and closing of the heat net (preferrably a zipper) is appropriately attached to a front portion of the neckline.
The upper body portion of the garment extends from the neck to proximate the hips of the wearer and has the arms connected thereto. The separate lower body portion extends from the wearer's waist and has the legs connected thereto. The lower edge of the upper body portion and the lower edges of the sleeves are gathered with the insertion of a means for causing said sleeves to be in substantial contact at the wearer's wrist area and means for causing the upper body portion to be in substantial contact at the wearer's hip area, such as for example an elastic band or a draw string in a casing or snaps. The top edge of the lower body portion and lower edge of the legs are gathered with the insertion of, for example, an elastic band in a casing. The combination of elasticized band and generous allowance of material results in a blousing effect which causes the garment to stand away from the body without the use of other devices.
In another embodiment, there would be a small mouth opening with a protective flap secured by VELCRO fastener to give the wearer easy access to his mouth for eating, drinking or other activities which require that the mouth be accessible through the otherwise fully enclosed head net.
In summary, the invention disclosed herein overcomes the several problems discussed previously. Most significantly, the insect protective garment of the instant invention does not provide for complicated features and unnecessary openings. Most importantly it has been found that if the mesh is semi-rigid and the seams are put together in such a manner so as to enhance the rigidity, and the seams are located as taught herein, the lightweight semi-rigid insect excluding mesh is all that is needed to provide the protection for the wearer. Additionally, because of the relative simplicity of the garment, it is lower in cost and more people, including children can afford to have such a garment.
Further advantages of the present invention will become apparent to those skilled in the art of insect protective garments upon examination of the drawings and the detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of the upper body portion of the garment embodying the invention;
FIG. 2 is a front view of the lower body portion of the garment embodying the invention;
FIG. 3 is an enlarged view of the fully enclosed head net;
FIG. 3A pictorially illustrates the head net piece of fabric 60 along with the vertical axis of symmetry and the horizontal axis of the approximate ellipse;
FIG. 3B pictorially illustrates the head net piece of fabric 60 folded along the vertical axis of symmetry (shown in shadow) and the head net after the corner is folded and sewn into the head net seam single hatching illustrates double layer and double hatching illustrates four layers;
FIG. 4 is an enlarged view of the fully enclosed head net showing an additional embodiment having a flap for access to the wearer's mouth;
FIG. 5 is a front view of the upper body portion of the garment embodying the invention further disclosing a zipper as a means for opening and closing the fully encloseable head net and permitting the wearer to place the fully encloseable head net to the rear of the wearer's face which zipper may also be incorporated into the head net embodiment illustrated in FIG. 4; and
FIG. 6 is an enlarged view of the fully encloseable head net illustrating the zipper being from the right side shoulder seam across the front of the garment to the left side shoulder seam.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and in particular to FIG. 1, there is illustrated at 10 the present invention in the form of an insect protective upper body garment. The garment 10 comprises an upper body portion 12 of lightweight semi-rigid insect excluding mesh, such as the screening commonly sold for use in campers or tents. The garment 10 is deliberately made loose fitting to enable the user to comfortably wear the garment over regular clothes, and to produce the blousing effect necessary for maximum insect protection properties.
The wearer's arms are protected by sleeves 14 made of the semi-rigid insect excluding mesh. An elastic band 16 is provided at the perimeter of the wrist end of sleeves 14 to exclude insects from between the wrist and the arm of the wearer. The elastic band 16 also produces the blousing effect 24 which maintains distance between the mesh and the wearer's skin.
The upper body garment 10 features a fully enclosed, one-piece head net 18 sewn to the upper body portion 12 at the neck. A multi-layered triangular fold 20 at the front of the head net seam 44 gives stability and shaping, and gives further support in the face area. The wide semi-square neckline 28 holds the head net 18 well away from the wearer's face which gives excellent protection and comfort without the use of other stiffening or spacing devices.
The triangular fold 20 is positioned on the head net 18 so that when it is donned by a user the forward facing edge or side 22 of the triangular fold 20 is slightly forward of and about parallel to the forehead of the wearer. As a typical dimension for the adult large size of garment this forward facing edge or side 22 may be about six (6) inches in length. The vertex 24 opposite the forward facing edge 22 of the triangular fold 20 is located approximately on the head net seam 44 and, for the large sized garment, the perpendicular distance from the forward facing side 22 to the vertex 24 is about 3 inches. The dimensions of the fold 20 will obviously vary with the size of the garment 10. However, the length of the forward facing edge 22 is at least equal to the width of the face of an average wearer of the garment 10 and in the case of the large size garment this length is about 6 inches more or less.
Preferably, all seams are sewn as one-half inch seams. Beside straight stitching, a commercial-type double overlock which creates a casing over the raw edge of the fabric may be used. It is well known that this form of construction provides excellent strength and durability to a manufactured garment. While it is not the intention to teach a method for making the garment 10 including incorporating triangular fold 20 into it, for there are many methods which could be used, it could be noted that the head net 18 may be made in the following manner. A patterned piece of mesh, which pattern is readily devised by one of ordinary skill, is appropriately folded and sewn along one edge. This seam, when garment 10 is complete, is head net seam 44. This seam 44 basically creates the head net 18 configuration or cavity having a neckline. When this head net is attached to the upper body portion 12 at the neckline 28, the head net portion is created without the triangular fold 20 but having a forward positioned point created by junction of the sewn edge and the fold of the mesh material. When this point is folded over (creating a forward facing edge or fold 22), pulled back by an appropriate amount, for example three (3) inches more or less, folded down and positioned onto head net seam 44 and attached thereto, triangle fold 20 is created. The point when folded down onto seam 44 becomes vertex 24. The mesh which makes up triangular fold 20 is now three layers thick. This three layer thick triangular fold 20, which is clearly more rigid than a thickness of any lesser number of layers, acts similarly to a built in cap visor. This construction, at least in part, makes the head net 18 have the novel features and advantages disclosed herein.
It is again noted that the methods for making the triangular fold 20 are not within the scope of this invention and such methods which may be used to make such a multilayered fold are not being claimed as a part of the invention, a method for making the fold 20 is offered even though an ordinarily skilled seamstress or garment maker would have no difficulty in creating such a fold 20 by any number of methods. Nevertheless, to further explain at least one method for making hood 18 and fold 20, FIGS. 3A and 3B and the following more detailed discussion of the making of hood 18 and fold 20 have been included.
Reference is now made to FIG. 3A which pictorially illustrate the hood piece of fabric 60 along with the vertical axis of symmetry and the horizontal axis of the approximate ellipse. The hood 18 is tailored from a piece of fabric 60 which is roughly the shape of an ellipse. The hood piece of fabric 60 has short axis of symmetry 62 but not necessarily symmetry about the long axis 64. The upper portion 63 (when the long axis of this approximate ellipse is horizontal) or the portion above the long/horizontal axis 64 being larger than the portion below 61 the horizontal axis 64. The lower portion edge of the piece of fabric 60 will eventually form the neckline seam 28 which seam creates an enlarged neckline which gives hood 18 a broader base thus helping to keep the hood 18 well away from the face of the wearer. The hood 18, when on the wearer, has somewhat the shape of a pyramid from the viewpoint that the base (neckline) is relatively large. Reference is now made to FIG. 3A and 3B. A first step in the making of the hood 10 and particularly triangular fold 20 may be to fold the hood piece 60 along the short axis of symmetry 62 and to create/sew a portion of seam 44 beginning at the neck line 28. Before sewing seam 44 all the way to the fold, i.e., the short axis of symmetry 62, the corner 24a created at the top of the folded piece (what will ultimately be what is being called vertex 24) is folded under (but it could also be folded over and rearward) so that the corner 24a is about three (3) inches rearward of what is now a new corner 22a which corner 24a is now about three (3) inches rearward of the new created corner 22a. The first created corner 24a and the edge created upon folding it under and rearward are placed in alignment with what will ultimately be the completion of seam 44. The action of folding corner 24a under or over results in a four layer thick section 65 shown cross hatched in FIG. 3B. The seam 44 is now complete noting that the first corner 24a and the new corner 22a become a part of seam 44. When the piece is turned "right-side out" vertex 24, forward facing edge 22 (where corner 22a was located), the three layer multilayer fold 20 and hood 18, unattached to the body portion 12, are created. The hood 18 is attached to 18 at seam 28. Edge 22 is about six (6) inches long and the distance from edge 22 to vertex 24 is about three (3) inches and there are now three (3) layers of material making up fold 20.
It is clear to anyone having ordinary skill as a garment maker that the hood 18 with the multilayered triangular fold 20 could be made by taking the so-called first corner 24a and folding it over the top of the outside of the hood with seam 44 already completed and the hood already attached (or not attached) at the neckline 28. The first corner 24a would be folded back so that it is about three (3) inches from the now created edge 22 and it is attached there by sewing or by any other acceptable means--24a becoming now vertex 24. Again, the result is the creation of triangular fold 20 having three (3) layers of material to provide rigidity to the hood 18.
The upper body portion 12 extends from the shoulders to proximate the hips of the wearer. An elastic band 27 is provided at the perimeter of the lower edge of the upper body portion 12 to exclude insects from between the elastic band and the body of the wearer. The elastic band 27 also produces the blousing effect 26 which maintains distance between the mesh and the wearer's skin.
Referring now to FIG. 2, there is illustrated at 30 the present invention in the form of an insect protective lower body garment. The garment 30 comprises a lower body portion 32 of semi-rigid insect excluding mesh preferably light in weight. The garment 30 is deliberately made loose fitting to enable the user to comfortably wear the garment over regular clothes, and to produce the blousing effect necessary for maximum insect protection properties.
The lower body portion 32 extend downward from an elastic waistband 34. A pair of leg members 36 are interconnected to the lower body portion 32. An elastic band 38 is provided at the lower or ankle ends of the leg members 36. The elastic band 38 also produces the blousing effect 40 which maintains distance between the mesh and the wearer's skin.
Referring now to FIG. 3, there is illustrated at 42 an enlarged view of the fully enclosed head net 18 sewn to the upper body portion 12 at the neckline 28. The multi-layered triangular fold 20 is clearly visible as is the head net seam 44 which extends the full back length of the head net 18, giving the head net 18 shape and stability.
Referring now to FIG. 4, there is illustrated at 42 an enlarged view of the fully enclosed head net 18 sewn to the upper body portion 12 at the neckline 28, showing an additional embodiment of a small mouth aperture 46 covered with a protective flap 48 secured by VELCRO fastener to give the wearer easy access to his mouth.
Referring now to FIG. 5 and FIG. 6, there is illustrated at 52 an enlarged view of the fully enclosed head net 18 sewn to the upper body portion 12 at the neckline 28 from a right side shoulder seam 56 across the rear portion 28B of the neckline 28 to the left side shoulder seam 58. A zipper 54 is appropriately attached to provide a closure of the front portion 28A of neckline 28. Zipper 54 being from the right side shoulder seam 56 across the front portion 28A of neckline 28 to the left side shoulder seam 58. Zipper 54 provides a means for opening and closing the fully encloseable head net 52 and permitting the wearer to place head net 52 to the rear of the wearer's face. Zipper 54 may also be incorporated into head net embodiment 42 illustrated in FIG. 4. While zipper 54 is shown to have two (2) pulls clearly a single pull type of zipper may also be used.
It will be readily apparent that the upper body garment 10 and the lower body garment 30 can be used together to cover substantially the entire body and limbs of the wearer, or worn separately in conjunction with other types of wearing apparel. It will also be readily apparent that the upper body garment 10 is donned by simple placing the opening formed by elastic band 27 located at the perimeter of the lower edge of the upper body portion 12 over wearer's head and pulling garment 10 down while inserting wearer's arms into sleeves 14. The lower body garment 30 is donned by simply stepping into the opening formed by elastic waist band 34, pulling garment 30 upward while inserting wearer's legs into leg members 36.
It is thought that insect protective garment of the present invention and many of its attendant advantages is understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts thereof without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred or exemplary embodiment thereof.
|
An insect proof garment for protection against mosquitoes, black flies and other insects is disclosed. The garment is made entirely from a lightweight semi-rigid insect excluding mesh and is comprised of a one-piece fully encloseable head net attached to an upper body portion, with the upper body portion extending from the neck to proximate the hips of the wearer and has sleeves connected thereto. There is a separate lower portion extending from the wearer's waist and having leg members connected thereto. The one-piece fully encloseable head net is preferrably stitched to an upper body portion from about a right side shoulder seam to about a left side shoulder seam thereby forming a rear portion of a neckline. A means for opening and closing of the heat net (preferrably a zipper) is appropriately attached to a front portion of the neckline. The zipper provides a means for the wearer to optionally open and close the fully encloseable head net and permits the wearer to place the head net to the rear of the wearer's face.
| 0
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to, prior provisional U.S. Patent Application Ser. No. 60/705,933 originally filed Aug. 3, 2005 entitled “CONCENTRATION AND SEPARATION OF BIOLOGICAL ORGANISMS BY ULTRAFILTRATION AND DIELECTROPHORESIS” from which benefit is claimed.
STATEMENT OF GOVERNMENT SUPPORT
This invention was made pursuant to Contract No. DE-AC04-94AL85000 by the United States Department of Energy and Sandia Corporation for the operation of Sandia National Laboratories and with funding from the Centers for Disease Control and Prevention, an agency of the United States Government. Therefore, the U.S. Government has certain rights in this invention.
TECHNICAL FIELD
The present invention relates to the development of methods of monitoring the safety of the public water supply by linking two analytical techniques, ultrafiltration and insulator-based dielectrophoresis in series to achieve significant concentration of microbes and pathogens for analysis. In particular, this invention relates to methods for determining whether and to what extent a municipal source of water is contaminated with a pathogen. More specifically, the invention is drawn to a method for detecting the presence of Cryptosporidium parvum oocytes.
BACKGROUND
The simultaneous concentration and recovery of microbes in drinking water is a critical procedure for responding to potential water-related bioterrorism events, and also would be an important technique for cost-effective routine monitoring of drinking water quality. Simultaneous microbe recovery can be accomplished in large-volume (100+ L) water samples using ultrafiltration (hereinafter “UF”), although little published research is available that indicates what process conditions are effective for yielding high recovery efficiencies for viruses, bacteria, and parasites in a single water sample.
Ultrafiltration is a technique that can be utilized for the simultaneous concentration of water-borne microbes but is more readily known by the public as a medical technique (hemodialysis) for people with kidney failure, where ultrafilter “dialyzers” are used to mimic the filtration activity of the kidneys by filtering blood to remove excess water, salts and waste products while retaining blood cells and proteins. Ultrafilters have pore sizes small enough to separate particles from water, as well as molecules that are larger than the Molecular Weight Cut-Off (hereinafter “MWCO”) of the ultrafilter. Ultrafilters typically have MWCOs in the 10,000-100,000 Dalton (“Da”) range (i.e. 10 kDa-100 kDa). Molecules smaller than the MWCO, therefore, such as water molecules, salts and small organic compounds, will simply pass through an ultrafilter as “permeate” and will not be co-concentrated with larger molecules and particles.
Ultrafiltration has been investigated since the 1970s as a technique for the concentration of microbes in drinking water (Belfort, G., Rotem, Y., Katzenelson, E., “Virus concentration using hollow fiber membranes-ii.” Water Research , 1976, v.10(4): pp. 279-284). In the early 1980s, tangential-flow hollow fiber UF was investigated and found to be effective for recovering viruses in large-volume (up to 100-L) of tap water samples (Dziewulski, D.M., Belfort, G., “Virus concentration from water using high-rate tangential-flow hollow fiber ultrafiltration,” Water Science and Technology , 1983 v.15:75-89). More recently, research reported greater than 50% recoveries for bacteriophages, E. coli and C. parvum oocysts seeded into 10-L surface water samples (Morales-Morales, H., Vidal, G., Olszewski, J., Rock, C., Dasgupta, D., Oshima, K., Smith, G., “Optimization of a reusable hollow-fiber ultrafilter for simultaneous concentration of enteric bacteria, protozoa, and viruses from water,” Applied Environmental Microbiology , 2003, v.69(7): pp. 4098-4102). While the simultaneous UF recovery results of Morales-Morales et al. were good, their technique relied on the use of a calf serum protocol to pre-treat the ultrafilter membranes prior to filtration. For certain applications (e.g., rapid response, and field-based filtration), pre-treatment with calf serum may not be appropriate or practical due to the potential for contaminating microbial growth in filters pre-treated with calf serum.
Research conducted at the Centers for Disease Control and Prevention, National Center for Infectious Diseases (hereinafter “CDC”) has shown that UF can be an effective technique for simultaneously concentrating viruses, bacteria, and parasites in 100 L samples of drinking water (Hill, V. R., Polaczyk A. L., Hahn D., Jothikumar N., Cromeans T. L., Roberts J. M., Amburgey J. E. “Development of a rapid method for simultaneously recovering microbes in drinking water using ultrafiltration with sodium polyphosphate and surfactants.” Applied Environmental Microbiology , 2005, 71(11):6878-6884). Ultrafilters that can accommodate 100 L water samples at practical process times have holdup volumes that are at best 250 mL or more; these volumes are too large for sensitive molecular or immunological detection of pathogens. Therefore, although it is likely that a UF procedure can be effective for simultaneous microbe recovery, it is unlikely that UF techniques are capable of reducing sample volumes to levels (<10 mL) sufficient for detecting low concentrations of microbes in a water sample and/or screening of the separated microbes based on specific conductivity and size.
In contrast, insulator-based dielectrophoresis (hereinafter “iDEP”) systems are known to be capable of capturing, concentrating, and separating microbes in very small (<1 to 10 mL) water samples. Cummings and Singh have demonstrated iDEP separation and trapping with polystyrene particles using DC electric fields and a variety of arrays of insulating posts (Cummings, E., Singh, A., “Dielectrophoretic trapping without embedded electrodes,” SPIE: Conference on Microfluidic Devices and Systems III , 2000, Santa Clara, Calif., Proc. SPIE, 4177: pp. 164-173). Chou et al., demonstrated iDEP trapping of DNA molecules, E. coli cells and blood cells using insulating structures and AC electric fields (Chou, C., Tegenfeldt, J., Bakajin, O., Chan, S., Cox, E., Darnton, N., Duke, T., Austin, R., “Electrodeless dielectrophoresis of single- and double-stranded DNA,” Biophysical Journal , 2002, v.83(4): pp. 2170-2179). Zhou et al., and Suehiro et al., used a channel filled with insulating glass beads and AC electric fields for separating and concentrating yeast cells in water (Zhou, G., Imamura, M., Suehiro, J., Hara, M., “A dielectrophoretic filter for separation and collection of fine particles suspended in liquid,” 37 th Annual Meeting of the IEEE - Industry - Applications - Society , 2002, Pittsburgh, Pa., Proc. IEEE: pp. 1404-1411; and Suehiro, J., Zhou, G., Imamura, M., Hara, M., “Dielectrophoretic filter for separation and recovery of biological cells in water,” IEEE Annual Meeting of the Industry - Applications - Society , 2003, Pittsburgh, Pa., Proc. IEEE, v.39: pp. 1514-1521). Finally, Lapizco-Encinas, et al., have demonstrated the selective dielectrophoretic trapping and concentration of live and dead E. coli cells, the separation of four different species of live bacterial cells, and the concentration of spores and viruses in both glass and plastic chips (Lapizco-Encinas, B. H., Simmons, B. A., Cummings, E. B., Fintschenko, Y., “Dielectrophoretic concentration and separation of live and dead bacteria in an array of insulators,” Analytical Chemistry , 2004, v.76(6): pp. 1571-1579; Lapizco-Encinas, B. H., Simmons, B. A., Cummings, E. B., Fintschenko, Y., “Insulator-based dielectrophoresis for the selective concentration and separation of live bacteria in water,” Electrophoresis , 2004, v.25(10-11): pp. 1695-704; Lapizco-Encinas, B. H., Davalos, R., Simmons, B. A., Cummings, E. B., Fintschenko, Y., “An insulator-based (electrodeless) dielectrophoretic concentrator for microbes in water,” Journal of Microbiological Methods , 2005, v.62(3), pp. 317-326; and Simmons, B. A., Lapizco-Encinas, B. H., Shediac, R., Hachman, J., Chames, J., Fiechtner, G., Cummings, E., Fintschenko, Y., “Polymeric insulating post electrodeless dielectrophoresis (iDEP) for the monitoring of water-borne pathogens,” The 8 th International Conference on Miniaturized Systems for Chemistry and Life Sciences , 2004, Malmo, Sweden, Royal Society of Chemistry Special Publication , 2005, v.297: pp. 171-173).
The combination of UF with iDEP, therefore, holds potential promise for allowing water utilities and associated industries to accurately assess low levels of pathogens in finished drinking water samples, whether due to natural or intentional contamination. This approach also could be applied to monitoring source water, industrial effluent, hospital discharge, and military water infrastructures for pathogens. Moreover, iDEP technology can separate live from dead/damaged microbes, thereby decreasing the chances of generating false-positive PCR results due to the presence of naked nucleic acid or non-viable microbes. In addition, the iDEP technique has the potential for sorting microbes according to type (e.g., viruses, bacteria, and parasites).
SUMMARY
To date, little research has been reported regarding technologies that are capable of real-time collection and analysis of water quality with respect to parasites, viruses and bacteria. It is believed that UF-iDEP technology would be successful in reliably detecting pathogens in large-scale applications. This is especially relevant as water utilities monitor for the presence of Cryptosporidium in an effort to determine Bin Classification as outlined in the proposed Long Term 2 Enhanced Surface Water Treatment Rule (hereinafter “LT2”), soon to be promulgated. This method of detection will provide a truer representation of source water quality by averaging over a larger data set, which could potentially prevent a water utility from being placed in a higher bin classification than would otherwise be necessary. In addition, real-time monitoring on finished treated water would provide validation of log removal determined by LT2. As a result, this new technology has the potential for not only saving considerable capital improvement expenditures as water utilities strive to comply with the inactivation requirements of LT2, but also to save operational costs by streamlining the monitoring process.
Considering the wide array of naturally occurring microbial agents that could be used to intentionally contaminate a drinking water system, a robust technique is needed to simultaneously concentrate viruses, bacteria, and parasites in water samples. In addition to its application for bioterrorism response, such a simultaneous recovery technique would be useful in the future for routine monitoring of drinking water quality. A method that can be used for analysis of a wide array of microbes of concern would streamline the microbial monitoring process, making it more efficient and effective.
It is therefore an objective of this invention to provide a method for simultaneously concentrating viruses, bacteria, and parasites in large-volume water samples with a high degree of efficiency and reliability.
Yet another objective of this invention is to provide microfluidic chips using iDEP for the capture and recovery of bacteria and viruses in drinking water samples initially concentrated using UF.
Still another objective is to provide techniques for optimizing an iDEP chip for the capture and recovery of protozoan parasites in drinking water samples initially concentrated using UF.
Yet another objective of this invention is to provide a method for simultaneously capturing and recovering viruses, bacteria, and parasites present in ultrafilter-concentrated drinking water samples.
Yet a further object of this invention is to extend the UF-iDEP technique to the capture of protozoan parasites such as for example, Cryptosporidium parvum and Giardia intestinalis , and generating microbial recovery efficiency data for the iDEP system as a stand-alone system and in conjunction with UF.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic depiction of the combined UF-iDEP system as applied to the monitoring of a given supply system.
FIG. 2A shows the simultaneous concentration and separation of E. coli and B. subtilis bacteria at a mean applied field of 75 V/mm.
FIG. 2B shows the simultaneous concentration and separation of E. coli and B. cereus bacteria at a mean applied field of 75 V/mm.
FIG. 2C shows the simultaneous concentration and separation of E. coli and B. megaterium at 90V/mm. The inlet cell concentration is 3×10 8 cells/ml. E. coli and Bacillus bacteria cells are respectively labeled green and red. The flow direction is from right to left. The background electrolyte is deionized water. The circular posts in the square array are 10-μm tall, 150-μm in diameter, and on 200-μm centers.
FIG. 3A shows dielectrophoretic trapping of B. subtilis spores. Spore concentration is a concentration of 2×10 7 spores/mL. Spores are labeled green. In this gray scale figure, spores appear white. Flow direction is from right to left. The background electrolyte is deionized water, pH=8, σ=2 μS/mm. The circular posts in the array are 10-μm tall, 200-μm in diameter, and on 250-μm centers. The mean applied electric field is 200 V/mm.
FIG. 3B shows dielectrophoretic release of B. subtilis spores.
FIG. 4A shows streaming tobacco mosaic virus (hereinafter “TMV”) in water since the applied electric field of 40 V/mm is not high enough to achieve trapping. Insulating post structures have the following dimensions: 200 μm in diameter, 250 μm center-to-center, 10 μm in height, made in glass. Flow is from right to left.
FIG. 4B shows dielectrophoretic trapping of TMV at E=80 V/mm.
FIG. 4C shows a magnified view of FIG. 3B , showing dielectrophoretic trapping of TMV at E=80 V/mm.
FIG. 5 shows a typical mean applied electric field (V/mm) to achieve dielectrophoretic trapping of the microorganisms studied in our system.
FIG. 6A shows a schematic plan-view of the iDEP chip-based set-up showing the manifold, the glass or polymer chip, and an enlargement of the flow microchannels.
FIG. 6B illustrates a cartoon showing how the insulating posts modify the field distribution.
FIG. 7A shows the trapping and concentration of 1-μm inert polystyrene particles at a field of 100 V/mm using a ZEONOR® iDEP device.
FIG. 7B shows the trapping and concentration of E. coli cells at a field of 60 V/mm using a ZEONOR® iDEP device.
FIG. 7C shows the trapping and concentration of B. thuringiensis spores at a field of 80 V/mm.
FIG. 8 shows the removal efficiency for E. coli cells with our current iDEP device made from glass.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The present invention contemplates using a hollow-fiber or a cross flow UF module as part of a filtration system that combines ultrafiltration and dielectrophoresis in an UF-iDEP system. While ultrafiltration is well known in the art (see U.S. Pat. No. 7,070,695, herein incorporated by reference) dielectrophoretic separation technology is relatively new and the methods for using it and the device structures are still evolving. Moreover, no one has yet suggested combining these two technologies wherein the former is used to provide a means for pre-concentrating a large volume of potentially contaminated water while the latter is used to separate and further concentrate species which may be present in the water sample in very low concentrations.
Any UF module having an MWCO value range of between 10 kDa to 300 kDa, an inlet or “feed” port, at least one primary outlet or “retentate” port for recirculating water contained within the UF module (and which also contains matter which cannot pass through the filter membranes), and a secondary outlet or “filtrate” port that allows filtered water to exit the system is believed useful as part of the UF-iDEP device described herein. Besides polysulfone, UF modules also may comprise polyethersulfone, cellulose triacetate, or other hydrophilic membranes and include those filtration units typically referred to as dialyzers with MWCO values such as 10 kDa or 20 kDa, and those typically referred to as hemoconcentrators with MWCO values such as 50, 65 or 100 kDa. In addition to hollow fiber membranes, there are also cross-flow UF systems using screens instead of hollow fibers. The concept is the same, i.e., recirculation under pressure to drive water molecules through a molecular-size filter, but retaining all particles. However, while hollow fiber membranes comprise a “tube” format, screen-based membranes comprise a “sheet.” Examples are regenerated cellulose products with MWCO values of 10 kDa to 300 kDa available from Millipore Corporation (Bedford, Mass.) and cross-flow 10, 30 and 100 kDa silicone encapsulated cassettes available from Sartorius North America, Inc., (Edgewood, N.Y.).
In the method, these ultrafilters may be pre-treated with a chemical dispersant, such as sodium polyphosphate (“NaPP”), and/or a nonionic surfactant such as Tween 80, Tween 20, or Triton X-100, and/or an organic reagent such as calf serum, fetal bovine serum or beef extract. In the method, NaPP may also be added to water samples at concentrations such as 0.1% or 0.01% or 0.001% to minimize microbial adhesion during the concentration process. After the desired concentration factor is achieved, the UF-iDEP technique provides for the option of using an eluting solution to desorb microbes that may be adhering to the ultrafilter surfaces that further enhances iDEP device performance, such as solutions that contain nonionic surfactants. This eluting solution may be applied to the ultrafilter in a “backwash” mode wherein the solution is pumped through the filtrate port of the ultrafilter and collected through either the feed or retentate ports. The eluting solution may also be added to the recirculation loop and pumped through the hollow fibers of the ultrafilter in cross-flow mode. The eluting solution may consist of a chemical dispersant such as sodium polyphosphate, a nonionic surfactant such as Tween 80 or Tween 20 or Triton X-100, an organic reagent such as calf serum, fetal bovine serum, glycine, or beef extract, and/or an antifoaming reagent such as Antifoam A (Sigma-Aldrich). CDC has found that the UF technique can recover 50-95% of the following microbes in 100-L tap water samples: echovirus 1, MS2 bacteriophage, phi-X174 bacteriophage, Salmonella, Escherichia coli, Enterococcus faecalis, Bacillus globigii spores, Bacillus anthracis (Sterne strain) spores, Yersinia pestis , and C. parvum oocysts.
Dielectrophoresis (hereinafter “DEP”), is an electrostatic transport mechanism with a nonlinear dependence on electric field and has an enormous potential for water analysis since it can be used to simultaneously concentrate and separate microorganisms from water. A non-uniform electric field produces an unbalanced electrostatic force on the charge of a particle producing a net movement of the particle toward the region of higher electric field gradient. The resulting motion is called dielectrophoresis and can occur in either direct (hereinafter “DC”) or alternating (hereinafter “AC”) electric fields. There are two regimes of DEP that have the potential for particle concentration. The first regime (known as “streaming dielectrophoresis”) occurs when DEP dominates diffusion, but does not overcome electrokinetic flow, so particles remain mobile. The second DEP regime (known as “trapping dielectrophoresis”) which occurs when DEP overcomes diffusion and electrokinesis. In this second regime, particles are dielectrophoretically immobilized and can be significantly concentrated to nearly solid density.
The majority of the studies on dielectrophoretic manipulation of microorganisms have been carried out using electrodes. Some of these studies have focused on the separation of bacterial cells. Others have focused on dielectrophoretic collection and analysis of protozoan parasites using DEP. Quinn, et al. collected Cryptosporidium parvum oocysts by recirculating a suspension of ozonated oocysts through an electrode chamber by using a pump (Quinn, C., Archer, G., Betts, W., O'Neill, J., “Dose-dependent dielectrophoretic response of cryptosporidium oocysts treated with ozone,” Letters in Applied Microbiology , 1996, v.22(3): pp. 224-228. Still others have focused on the dielectrophoretic separation of yeast cells as well as viruses and parasites.
The most common approach for carrying out DEP studies is to use AC electric fields and closely spaced electrode arrays to produce the nonuniform fields required for DEP to occur. The development of micro-fabrication techniques has enabled the construction of larges arrays of microelectrodes. Microelectrode array-based DEP systems, however, face application-limiting issues such as the decay of the electric field above the planar array electrodes which directly affects the DEP force exerted on the particles, reducing trapping efficiency. In addition, electrode degradation can occur at high applied electric fields.
iDEP offers a promising alternative to electrode-based DEP. In iDEP the nonuniform electric field is produced by an array of insulators, rather than an array of electrodes. Moreover, iDEP technology has the potential to be an efficient technique for further concentrating microbes in ultrafilter concentrates. Devices for iDEP can be made from insulating materials (e.g., plastics) that are less expensive and easier to handle, thus opening the possibility for high-throughput and large-volume devices. By utilizing iDEP, selective concentration can be achieved in a single automated device.
Little research has been reported regarding technologies that are capable of simultaneously concentrating viruses, bacteria and parasites in large-volume water samples with a high level of efficiency and reasonable processing times. For large-volume (>10-L) water samples, tangential flow ultrafiltration is a promising technique for simultaneously concentrating these diverse microbes into sample volumes of approximately 300 mL or less. Using hollow fiber ultrafilters, CDC researchers have been able to simultaneously recover viruses such as echovirus 1 and MS2 bacteriophage, bacteria such as B. globigii spores and Salmonella enterica subspecies enterica serovar Typhimurium and Cryptosporidium parvum oocysts with average recovery efficiencies of above 50% in 100-L tap water samples. The CDC UF protocol incorporates the use of chemical dispersants to minimize microbial adhesion to the ultrafilter fibers, as well as the use of an elution solution to desorb adhered microbes either through filter backwashing or cross-flow elution. This UF procedure is capable of concentrating 100 L of drinking water to <400 mL in less than 2 hours.
The lower limit of concentration for high-volume (˜100 L) tangential flow ultrafilters, however, is approximately 250 mL, which represents volumes far larger than desirable for detection of low levels of pathogens in water samples. The iDEP technology is capable of concentrating viruses, bacteria and parasites in water samples using a DC electric field with electrodes placed at the inlet and outlet reservoirs. In the iDEP process, a nonuniform electric field is created across a microchannel using DC voltage. Microbes in water samples are trapped within the iDEP device as they flow through the electric field maintained above a threshold DC voltage. Using fluorescent microscopy, we have shown that bacterial cells and virus particles can be captured using iDEP. No other single sampling technique has similar potential for sorting microbes based on size and surface properties derived from large-volume water samples. While current prototypes of the iDEP microfluidic “chip” are designed to process water samples on the milliliter scale, the technology is scaleable to the level at which hundreds of milliliters could be processed.
A UF-iDEP system such as is shown schematically in FIG. 1 provides a system and method for sampling/detecting water-borne enteric microbes. The present embodiment is therefore comprised of a UF module and an iDEP module together with assorted valves and conduit to place each in fluid communication with the other. Additionally, the UF module typically comprises a filter membrane contained within a housing through which water is passed. By using the embodiment shown in FIG. 1 , a large sample of source water (10 L-100 L) from a municipal treatment facility, for instance, may first be passed through a UF module where a portion of the sample in which particles carried in the inflowing water, and which are larger than the MWCO of the UF filter, are retained (the retentate) and collected. This “pre-concentrated” sample (“retentate”) provided by the UF module comprises a volume of between about 250 mL and 400 mL. After the desired volume of source water has passed through the UF module, a small fraction of the water retained within the filter housing (about 10 mL) is passed to one or several microfluidic iDEP module(s) through a fluid manifold connected to a large number of microfluidic flow channels. Each of the separate iDEP channels, in turn, comprises a plurality of flow structures such as those disclosed in commonly owned U.S. Pat. No. 7,014,747 and U.S. patent application Ser. Nos. 10/176,322 and 10/969,137, herein incorporated by reference. These flow structures may comprise any useful element such as posts, prisms, polyhedrons, cylinders, or cones, and may have any useful cross-sectional shape such as a crescent, an ellipse, an oblate oval, a tear drop, a pear, a dumbbell, or a limacon. The flow structures may also comprise depressions in a substrate bold.
As the particles collected in the UF retentate sample portion pass into the iDEP module and around these flow structures, an electric field is established between the inlet and outlet ends of each flow channel and the particles within the flow channels are temporarily trapped by an electrical field. The electrical potential generates a dielectrophoretic field force which is adjusted to overcome the electrokinetic and hydrodynamic drag forces on the water moving through the electric field. The number of particles trapped in the field grows with time until the applied field is removed and thereby temporarily traps particles suspended in the pre-concentrated water sample. After a set period of time, the electric field can then be removed and the concentrated particles eluted out of the iDEP structures to provide a final analyte volume of about 25 μL or below which now can be analyzed by known methods such a fluorescent microscopy.
Currently, bacteria, spores, and viral particles have been demonstrated to trap and concentrate in DC electric fields examples of which are shown in FIGS. 2-4 , respectively, (Lapizco-Encinas, et al., Analytical Chemistry , 2004, op. cit.; Lapizco-Encinas, et al., Electrophoresis , 2004, op. cit.; and Simmons, et al., Royal Society of Chemistry , 2005, op. cit). FIG. 5 shows the typical applied electric fields required to trap bacteria, spores, and viruses in our current micro iDEP device made from glass.
FIGS. 6A and 6B show the current chip suitable for viral, spore, and bacterial particles. Channel depths are on the order of 10 microns. For parasites, a deeper channel (50-100 μm) and larger post features (250 to 500 μm center to center) will be used. Additionally, to prevent parasites and viral particles from nonspecifically adsorbing to the insulating material itself, the chips will be fabricated out of ZEONOR®, a polyolefin thermoplastic that we have found to be resistant to virus adsorption (ZEONOR® is a registered mark owned by the Nippon Zeon Co., Ltd. Corporation Japan, Tokyo, Japan; the product is available in the U.S. from Zeon Chemicals L.P., Louisville, Ky.). The SNL team has successfully fabricated polymeric-based chips for iDEP (Simmons, et al., 2004, op. cit). Concentration of inert particles, bacteria, and spores has been achieved using these polymeric-based iDEP devices. FIGS. 7A-C show the results obtained using a ZEONOR®-based iDEP device, wherein the circular posts shown in the square array are 50-μm tall, 150-μm in diameter, and on 200-μm centers.
Removal efficiency data has been obtained for E. coli cells suspended in deionized water and is shown in FIG. 8 . The experimental results shown in FIG. 8 were conducted at applied mean electric fields of 50 V/mm, 75 V/mm and 100 V/mm and dwell times of 20 and 40 seconds, respectively. The effluent from the microdevice was analyzed by using fluorescence microscopy and removal efficiency values calculated. From FIG. 8 it is seen that removal efficiencies above 90% have been achieved using the glass microfluidic device design.
It is contemplated that the iDEP set-up for simultaneous microbe recovery will consist of three iDEP chips in series, each having a physical design and applied electric field for specific capture of each class of microbe (e.g., a parasite capture chip followed by a bacteria capture chip, followed by a virus capture chip).
Having thus described exemplary embodiments of the present invention, it should be noted by those skilled in the art that the foregoing disclosure is exemplary only and that various other alternatives, adaptations, and modifications may be made within the scope of the present invention. Accordingly, the present invention is not limited to the specific embodiments as illustrated herein.
Finally, to the extent necessary to understand or complete the disclosure of the present invention, all publications, patents, and patent applications mentioned herein are expressly incorporated by reference therein to the same extent as though each were individually so incorporated. A list of these references is appended to and herein merged with this document.
|
Disclosed is a method for monitoring sources of public water supply for a variety of pathogens by using a combination of ultrafiltration techniques together dielectrophoretic separation techniques. Because water-borne pathogens, whether present due to “natural” contamination or intentional introduction, would likely be present in drinking water at low concentrations when samples are collected for monitoring or outbreak investigations, an approach is needed to quickly and efficiently concentrate and separate particles such as viruses, bacteria, and parasites in large volumes of water (e.g., 100 L or more) while simultaneously reducing the sample volume to levels sufficient for detecting low concentrations of microbes (e.g., <10 mL). The technique is also designed to screen the separated microbes based on specific conductivity and size.
| 1
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to an asynchronous transfer mode (ATM) connection band control method and a control system. More particularly, the invention relates to an ATM connection band control method and a system effectively using connection bands which respective ATM circuit ports have.
[0003] 2. Description of the Related Art
[0004] In FIG. 9 , the conventional ATM connection band control system includes an input circuit 1 , an input buffer control portion 2 c, an ATM switch control portion 3 c and an output buffer control portion 4 .
[0005] The input buffer control portion 2 c includes a buffer accumulation memory 21 c for accumulating input cells before feeding to an ATM switch, an input buffer function portion 22 c performing writing control of ATM cells to a buffer accumulation memory and queue management of the buffer, a usage parameter control (UPC) portion 23 c monitoring whether a traffic of a user in communication exceeds a band declared upon switched virtual connection (SVC) setting demand or not, a connection admission control (CAC) portion 24 c controlling whether a demand is to be admitted or not upon reception of signaling of connection setting demand for new SVC of constant bit rate (CBR), a real time variable bit rate (rt-VBR), a non-real time variable bit rate (nrt-VBR), a buffer control memory 26 c storing parameter or data necessary for operation of the input buffer function portion 22 c and the usage parameter control (UPC) portion 23 c, and a circuit interface control portion 20 c interfacing the input buffer function portion 22 c and the input circuit 1 for feeding the input cell to the ATM switch.
[0006] The ATM switch control portion 3 c includes an ATM switch 30 c performing switching of the ATM cell, CPU 31 c performing central control process of overall system and a main memory 32 c for residence of operation program or data necessary for operation of CPU 31 c.
[0007] FIG. 10 is a detailed block diagram showing a buffer control memory 26 c relating to the connection band of SVC of FIG. 9 and its peripheral control portion. The buffer control memory 26 c includes a memory 261 c storing band data per declared connection upon SVC setting demand necessary for control operation of the usage parameter control (UPC) portion 23 c, a memory 263 c storing connection band data of SVC of CBR, rt-VBR, nrt-VBR, and a memory 264 c for storing data necessary for other connection admission control, such as available band of ATM circuit port and so forth.
[0008] Only connection band data of SVC of currently established connection is present in the buffer control memory 26 c for performing connection admission control and connection band control.
[0009] In this case, the connection band control and the connection admission control is performed for acquiring necessary connection band in first-come-first-set order without considering connection band of preferential SVC when the SVC of established connection issues setting demand. Therefore, when connection of the preferential SVC is not yet established and issue setting demand for connection later, the SVC setting demand is not always admitted and can be rejected until the necessary band is released in certain remaining band of the ATM circuit port.
[0010] On the other hand, even when the connection of the preferential SVC is established, if the preferential SVC is deleted once, the connection band acquired unconditionally is released. Therefore, even when the preferential SVC issues setting demand again, there is not guarantee to acquire connection band. If other SVC sets the connection earlier, the setting demand may be rejected until the necessary band is released in certain remaining band of the ATM circuit port.
[0011] In the foregoing conventional ATM band control method, the first problem is that, in acquiring of the connection bands of each SVC of the CBR, rt-VBR, nrt-VBR requiring fixed band, the connection admission control (CAC) performing control on the basis of the band information of those actually established connection to acquire the band for those established connection at earlier timing for finite connection bands of each ATM circuit port. However, judgment is not made whether acquiring of band has to be done preferentially or not.
[0012] The second problem is that there is not means for preliminarily registering data for setting the band of the connection to be preferentially assigned without actually establishing connection and making judgment upon establishing connection.
[0013] The third problem is that when connection for SVC having high preference (preferential SVC) among SVCs is temporarily released for some hindrance to open the band, if the preferential SVC is recovered from hindrance and the preferential SVC demands resetting of connection and connection setting demand for other SVC having low preference (non-preferential SVC) is done at earlier timing, since connection setting of the non-preferential SVC is performed normally, there is no guarantee for permitting resetting of the preferential SVC. Therefore, whether resetting of connection is successful or not simply depends on remaining band of the ATM circuit port.
[0014] On the other hand, the fourth problem is that there is no means for performing control for ensuring and guaranteeing resetting of connection band for the preferential SVC when the connection band of the SVC having high preference, such as CBR or the like is temporarily deleted and the band is opened, and when the connection setting demand is issued by other SVC having lower preference while the connection of the preferential SVC is deleted. The connection band is inherently acquired in order to demanding of setting irrespective of preferential order. Therefore, for the SVC having high preference while not used constantly, connection has to be maintained irrespective whether the connection is used for communication or not to constantly occupy the connection band.
[0015] The fifth problem is that even when the SVC having high preference actually occupies the connection band constantly, the band may be used for the SVC of ATM category service which does not require fixed band, such as available bit rate (ABR), unspecified bit rate (UBR) and so forth as long as not cell flows in the connection. However, in the prior art, even when the connection is not actually used, an idle data is transmitted in CBR, the band acquired by CBR may not be released unless the setting of connection is actually deleted.
SUMMARY OF THE INVENTION
[0016] The present invention has been worked out for solving the problems as set forth above.
[0017] According to the first aspect of the present invention, an asynchronous transfer mode connection band control method in a system for transmitting and receiving an asynchronous transfer mode cell using an asynchronous transfer mode network, comprises:
[0018] first step of preliminarily setting a connection band as band acquiring data for preferential switched virtual connection having high preference in the asynchronous transfer mode network among connections of an asynchronous transfer mode service categories requiring a fixed band, of constant bit rate, in which a traffic is generated at a constant interval in the switched virtual connection via the asynchronous transfer mode network, and a real time variable bit rate or non-real time variable bit rate generating a variable traffic having burst characteristics in transmission rate, such as variable rate video or public network frame relay service; and
[0019] second step of controlling the connection band including the band acquiring data for enabling cooperation with a connection admission control for the constant bit rate, the real time asynchronous transfer mode and the real time variable bit rate and the non real-time variable bit rate, and performing reception control under a condition where the band for the preferential switched virtual connection is constantly acquired, with controlling the connection band in a range where a band for the preferential switched virtual connection is constantly acquired and guaranteed, a band for a non-preferential switched virtual connection can be constantly acquired upon the connection admission control for the non-preferential switched virtual connection.
[0020] In the preferred embodiment, it is preferred that in the first step, the connection band of the constant bit rate, the real time variable bit rate and the non-real time switched virtual connection, is preliminarily set and stored in a buffer control memory irrespective whether a connection of the preferential switched virtual connection is established or not, and in the second step, control is performed with taking the preliminarily set band acquiring data and data necessary for the connection admission control of other connection including the connection band of the switched virtual connection used currently and data necessary for connection admission control.
[0021] In the second step, upon reception of a signal for setting demand of new switched virtual connection from a calling terminal, judgment may be made whether the switched virtual connection is the preferential switched virtual connection having high preference and having band being acquired.
[0022] In the second step, when the new switched virtual connection setting demand from the calling terminal is for a non-preferential switched virtual connection, connection band may be controlled within a range where the band of the preferential switched virtual connection is certainly maintained irrespective whether the connection of the preferential switched virtual connection, for which the band is already reserved, is established or not by cooperation of a connection reception control processing portion and a connection band controller.
[0023] In the second step, when the new switched virtual connection from the calling terminal is the preferential switched virtual connection, for which band has already been reserved, connection admission may be controlled under a condition where a band of the preferential switched virtual connection within a range where the band of the preferential switched virtual connection is certainly maintained.
[0024] Data of connection band of the preferential switched virtual connection of the constant bit rate, the real time variable bit rate and the non-real time variable bit rate is set irrespective whether the connection for the switched virtual connection is established or not, and for the preferential switched virtual connection, connection admission control and connection band control may be performed for constantly acquiring the band.
[0025] According to the second aspect of the present invention, an asynchronous transfer mode connection band control system in a system for transmitting and receiving an asynchronous transfer mode cell utilizing an asynchronous transfer mode network, comprises:
[0026] data storage means for storing a connection band of a preferential switched virtual connection having high preference in the asynchronous transfer mode network being stored preliminarily as a band acquiring data and storing acquired band data of a switched virtual connection currently established connection; and
[0027] connection band control means for performing control of connection band on the basis of a total number of bands derived by a sum of the band acquiring data and the acquired band data stored in the data storage means.
[0028] According to the third aspect of the present invention, an asynchronous transfer mode connection band control method in a method for transmitting and receiving an asynchronous transfer mode cell utilizing an asynchronous transfer mode network, comprises:
[0029] providing data storage means for storing a connection band of a preferential switched virtual connection having high preference in the asynchronous transfer mode network being stored preliminarily as an band acquiring data and storing acquired band data of a switched virtual connection currently established connection; and
[0030] connection band control step of performing control of connection band on the basis of a total number of bands derived by a sum of the band acquiring data and the acquired band data stored in the data storage means.
[0031] In the preferred construction, the connection band control means or the connection band control step may add the band acquiring data of the connection band of the switched virtual connection when setting demand for acquiring the connection band for the switched virtual connection is issued and the demand is admitted.
[0032] The connection band control means or the connection band control step may transfer the connection band data of demanded switched virtual connection from the band acquiring data to the acquired band data when the switched virtual connection setting demand is issued and the switched virtual connection for which setting demand is issued is the preferential switched virtual connection, for which band data is preliminarily acquired.
[0033] The connection band control means or connection band control step may make judgment whether the switched virtual connection setting demand is to be admitted or not on the basis of a total number of bands derived by a sum of the current band acquiring data and the acquired band data when the switched virtual connection setting demand is issued and the switched virtual connection for which setting demand is issued, is not the preferential switched virtual connection, for which band data is preliminarily acquired.
[0034] The connection band control means or connection band control step may add the connection band data of the switched virtual connection in the acquired band data when the switched virtual connection setting demand is admitted.
[0035] The connection band control means or connection band control step may transfer the connection band data of the switched virtual connection from the acquired band data to the band acquiring data when a switched virtual connection deletion demand is issued and the switched virtual connection is the preferential switched virtual connection for which the band data is preliminarily acquired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The present invention will be understood more fully from the detailed description given hereinafter and from the accompanying drawings of the preferred embodiment of the present invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only.
[0037] In the drawings:
[0038] FIG. 1 is a schematic block diagram of the preferred embodiment of an ATM connection band control system according to the present invention;
[0039] FIG. 2 is a detailed block diagram of the major part of the first embodiment of the ATM connection band control system according to the present invention;
[0040] FIG. 3 is a flowchart showing operation of the first embodiment of the ATM connection band control system according to the invention;
[0041] FIG. 4 is a flowchart showing operation of the first embodiment of the ATM connection band control system according to the invention;
[0042] FIG. 5 is a flowchart showing operation of the first embodiment of the ATM connection band control system according to the invention;
[0043] FIG. 6 is a block diagram of the major part of the second embodiment of the ATM connection band control system according to the present invention;
[0044] FIG. 7 is a block diagram of the major part of the third embodiment of the ATM connection band control system according to the present invention;
[0045] FIG. 8 is a block diagram of the major part of the fourth embodiment of the ATM connection band control system according to the present invention;
[0046] FIG. 9 is a block diagram showing the conventional ATM connection band control system; and
[0047] FIG. 10 is a detailed block diagram showing a part of the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0048] The present invention will be discussed hereinafter in detail in terms of the preferred embodiment of the present invention with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific detailed. In the other instance, well-known structures are not shown in detail in order to avoid unnecessary obscurity of the present invention.
[0049] FIG. 1 is a block diagram showing the first embodiment of an ATM connection band control system according to the present invention. The shown embodiment of the ATM connection band control system includes an input circuit 1 , an input buffer control portion 2 , an ATM switch control portion 3 and an output buffer control portion 4 .
[0050] The input buffer control portion 2 includes a buffer accumulation memory 21 for accumulating an input cell before feeding an ATM switch, an input buffer function portion 22 performing queue management of a control buffer for writing an ATM cell in the buffer accumulation memory 21 , a usage parameter control (UPC) portion 23 monitoring whether a traffic of the user in communication exceeds a band declared upon demanding setting of SVC or not, a connection admission control (CAC) portion 24 controlling whether a demand is to be admitted or not upon reception of signaling of connection setting demand for new SVC of CBR connection generating a traffic at a predetermined interval via an ATM network from a calling terminal, such as voice, rt-VBR connection or nrt-VBR having variable traffic, in which a transmission rate has burst property, such as variable rate video or a public network frame relay service, a connection band controller 25 performing management or judgment control of connection band data of SVC required for control operation of the connection admission control (CAC) portion 24 and data necessary for other connection admission control such as available band of the ATM circuit port and so forth, buffer control memory 26 for storing parameters and data necessary for operation of the input buffer function portion 22 , the usage parameter control (UPC) portion 23 , the connection admission controller (CAC) portion 24 and the connection band controller 25 , and the interface control portion 20 for interfacing between the input buffer function portion 22 for feeding the input cell to the ATM switch and the input circuit 1 .
[0051] It should be noted that the connection admission controller (CAC) is a control whether the demand is to be admitted upon receiving signaling of demand of connection setting for the SVC of CBR, rt-VBR and nrt-VBR of ATM service category requiring fixed band, and is a control held inoperative upon receiving signaling of demand of connection setting for the SVC of ABR or UBR in another ATM service category.
[0052] The ATM switch control portion 3 includes an ATM switch performing switching of ATM cell, CPU 31 performing central control process of overall system and a main memory for residence of operation program and data necessary for operation of CPU 31 . FIG. 2 is a block diagram showing the buffer control memory 26 relating to the connection band of the SVC and peripheral control portion.
[0053] The buffer control memory 26 , as data structure in the memory 25 storing the buffer control memory data, includes a memory 261 storing a band data per connection declared upon SVC setting demand necessary for control operation of the usage parameter control (UPC) portion 23 , a memory 262 storing band data to preliminarily acquire connection band of the preferential SVC necessary for control operation of the connection band controller 25 , a memory 263 storing connection band data of the SVC of CBR, rt-VBR and nrt-VBR established current connection, and a memory 264 storing data necessary for connection admission control, such as available band and so forth of ATM circuit port.
[0054] Next, operation of the shown embodiment will be discussed with reference to the drawings. SVC setting demand signaling for establishing connection of the SVC received from the ATM network is fed to the input buffer control portion 2 from the input circuit 1 of FIG. 1 similarly to ATM cell.
[0055] At this time, in the input buffer control portion 2 , the judgment and control whether the writing and reading in and from the buffer accumulation and the new SVC setting demand by the connection admission control portion 24 are to be accepted or not are performed.
[0056] Next, operations of the connection admission control portion 24 , the connection band controller 25 , the buffer control memory 26 and the usage parameter control portion 23 in FIGS. 1 and 2 will be discussed with reference to FIGS. 3 and 4 . In operational flowchart for acquiring connection band of FIG. 3 , upon occurrence of setting demand for acquiring connection band for the SVC, content of setting demand of the SVC is checked at step S 101 . Thereafter, at step S 102 , judgment is made whether the SVC in question is the setting demand for acquiring the connection band of the preferential SVC preliminarily acquired band data presenting in the memory 262 which stores the band acquiring data of FIG. 2 .
[0057] A criterion for making judgment whether the SVC, for which setting is demanded, is the preferential SVC, for which the band data is preliminarily acquired, or not, can be made by data which the SVC inherently have upon establishing connection, or a combination of a plurality of data.
[0058] As inherent data which the SVC should have upon establishment of connection, there are a virtual path identifier (VPI) value, a virtual channel identifier (VCI) value, an input and output port (number) of the SVC of CBR, rt-VBR, nrt-VBR, ABR, UBR and so forth, and a peak cell rate (PCR), a sustainable cell rate (SCR), a maximum burst size (MBS) as traffic parameter defined at an ATM Forum Traffic Management Specification Version 4.0 (af-tm-0056.000, April, 1996: hereinafter referred to as “TM4.0”) and so forth. By one of these or a combination of a plurality of data, the SVC is specified to make judgment whether the setting demanded SVC is the preferential SVC, for which the band data is preliminarily acquired, or not.
[0059] When the setting demanded SVC is the preferential SVC, for which the band data is preliminarily acquired, a process for guarding double registration to the memory 262 storing the connection band acquiring data of FIG. 2 is performed by the connection band controller 25 (S 103 ) to terminate the process for connection band acquiring.
[0060] On the other hand, when the setting demanded SVC is not the preferential SVC, for which the band data is preliminarily acquired, a total band number derived by a sum of the current band acquiring data stored in the memory 262 and the acquired band data stored in the memory 263 is calculated as a band acquiring judgment reference data (S 104 ). On the basis of the band acquiring judgment reference data and data necessary for other CAC, judgment whether setting demand for acquiring connection band of SVC is admitted or not, is made by the connection band controller 25 (S 105 ).
[0061] When judgment is made that the setting demand for connection band acquiring can be admitted in the judgment whether the setting demand of the connection band acquiring of SVC (S 106 ) is accepted or not, process is performed to add the connection band of the SVC to be acquired in the memory 262 storing the band acquiring data in the connection band controller 25 (S 107 ).
[0062] On the other hand, at step S 106 , when judgment is made that the setting demand of connection band acquiring cannot be admitted, for the setting demand of connection band acquiring of SVC, rejection is notified (S 108 ). Then, process for acquiring connection band is terminated.
[0063] In operational flowchart of the connection admission control of FIG. 4 , upon occurrence of SVC setting demand S 201 , the content of the setting demand of SVC is checked to make judgment whether the SVC in question is the preferential SVC already acquired the band data presenting in the memory 262 which stores the band acquiring data of FIG. 2 , at step S 202 . As criterion for making judgment whether the SVC setting demand is the connection setting demand of the preferential SVC, for which the band data is already acquired, or not, the judgment can be made by data which the SVC inherently have upon establishing connection, or a combination of a plurality of data similarly to step S 102 of FIG. 3 . By specifying the SVC, judgment is made whether the setting demanded SVC is the preferential SVC which has been acquired preliminarily or not.
[0064] Since the SVC is the preferential SVC which has been acquired the connection band via the operation flow including judgment of setting shown in FIG. 3 , the result of judgment at step S 202 indicates that the SVC setting demand can be admitted when the SVC for which setting is demanded is the preferential SVC for which the band data is acquired preliminarily (S 203 ). Accordingly, the process for transferring the demanded connection band data from the memory 262 which stores band acquiring data to the memory 263 storing the acquired band data, is performed by the connection band controller 25 (S 204 ). Then, to the connection admission control portion 24 , execution of the acceptable process for the SVC setting demand is notified (S 209 ).
[0065] On the other hand, if the SVC for which setting is demanded is not the preferential SVC preliminarily acquired the band data, the total band number is derived from the sum of the content of the memory 262 storing the band acquiring data and the content of the memory 263 storing the acquired band data, as the band admission judgment reference data (S 205 ). Then, on the basis of the band admission judgment reference data and data necessary for other CAC, judgment is made whether the SVC setting demand is to be admitted or not by the connection band controller 25 (S 206 ).
[0066] By the judgment whether the SVC setting demand is to be admitted or not (S 207 ), if the SVC setting demand is judged as acceptable, process is performed in the connection band controller 25 for adding the connection band data of the demanded SVC in the memory 263 storing the acquired band data (S 208 ). Then, similarly to the case where the SVC for which setting is demanded at step S 202 is the preferential SVC for which the band data is preliminarily acquired, execution of the admission process for the SVC setting demand is notified to the connection admission control portion 24 .
[0067] After notification of admission process at S 209 , the band data per connection declared upon SVC setting demand is registered in the memory 261 which stores the band data per connection, by the connection admission control portion 24 (S 210 ). On the other hand, by making judgment whether the SVC setting demand is to be admitted or not at step S 207 , rejection of admission for the SVC setting demand is notified to the connection admission control portion 24 (S 211 ). Then, the process of accepting connection of the SVC is terminated.
[0068] In an operational flowchart of connection deletion control of FIG. 5 , upon occurrence of SVC setting deletion demand at step S 301 , the SVC to be deleted is checked. At step S 302 , judgment is made whether the SVC in question is the preferential SVC already acquired the band data in the memory which stores the band acquiring data of FIG. 2 , or not. Here, as criterion for making judgment whether the connection setting demand of the preferential SVC, for which the band data is already acquired, the judgment can be made by data which the SVC inherently have upon establishing connection, or a combination of a plurality of data similarly to step S 102 of FIG. 3 . By specifying the SVC, judgment is made whether the setting demanded SVC is the preferential SVC which has been acquired preliminarily.
[0069] Since the SVC is the preferential SVC which has been acquired the connection band via the operation flow including judgment of setting shown in FIG. 3 , the result of judgment at step S 302 indicates that the SVC for which deleting is demanded is the preferential SVC for which the band data is acquired preliminarily, the process for transferring the demanded connection band data from the memory 263 which stores acquired band data to the memory 262 storing the band acquiring data, is performed by the connection band controller 25 (S 303 ). Then, process for the SVC setting deletion demand is executed to delete the connection band data declared upon demanding SVC setting from the memory 261 which stores the band data per connection (S 304 ). Then, a process for deleting setting of SVC is terminated.
[0070] On the other hand, the result of judgment at step 302 indicates that the SCV for which deleting is demanded is not the preferential SVC for which the band data is acquired preliminarily, the process for deleting the deleted connection band data from the memory 263 which stores acquired band data, is performed by the connection band controller 25 (S 305 ). Then, process for the SVC setting deletion demand is executed to delete the connection band data declared upon demanding SVC setting from the memory 261 which stores the band data per connection (S 304 ). Then, a process for deleting setting of SVC is terminated, as the result of judgment as step 302 indicates that the SVC for which deleting is demanded is the preferential SVC for which the band data is acquired preliminarily.
[0071] Next, discussion will be given for the second embodiment of the ATM connection band control system according to the present invention. In the shown embodiment illustrated in FIG. 6 , the usage parameter control (UPC) portion 23 and the memory 261 storing the band data per connection declared upon SVC setting demanding performs control and function for setting and deleting connection of the SVC. On the other hand, the connection admission control (CAC) portion 24 and a memory 764 storing data necessary for other CAC, such as available band of the ATM circuit port, perform setting and deletion of connection of SVC of CBR, rt-VBR and nrt-VBR. Concerning a memory 762 storing connection band data to be preliminarily set as band acquiring data of the connection band, a memory 763 storing the connection band data of CBR, rt-VBR and nrt-VBR which has already been established connection, and the connection band controller 25 which controls these connections are performed not only for the SVC but also for permanent virtual circuit (PVC).
[0072] Concerning the permanent virtual connection (PVC), similarly to the connection band control of SVC, the memory 762 storing the band data preliminarily acquiring the connection band of the connection having high preference (hereinafter referred to as “preferential connection”) irrespective of PVC, SVC for connection, such as CBR, rt-VBR, nrt-VBR of ATM service category requiring fixed band having values of a program clock reference (PCR), SCR, MBS defined in T.M4.0, the memory 763 storing the band data of the preferential connection currently established, and a memory 260 A storing data necessary for other connection admission such as available band of the ATM circuit port are formed to enable preliminarily set the band acquiring data necessary for preferential connection irrespective either PVC or SVC. Also, concerning SVC, cooperation with the connection admission control is possible.
[0073] By connection band control including the band acquiring data in the connection band controller 25 irrespective of PVC, SVC, the connection band having low preference, for which constantly acquiring and guaranteeing the band is not required, is controlled within a range where band for the preferential connection is constantly acquired and guaranteed when the connection band for non-preferential connection is to be controlled. For the preferential connection, control of band of the preferential connection including admission control of the preferential SVC among the preferential connection is performed, for which the band is constantly acquired and guaranteed irrespective whether the connection of the preferential SVC is established or not. Thus, finite connection bands of each ATM circuit port can be used efficiently.
[0074] Next, discussion will be given for the third embodiment of the ATM connection band control system with reference to the drawings. In FIG. 7 , the shown embodiment is differentiated from the ATM switch control portion in the embodiment shown in FIG. 2 in that a connection setting control portion 733 is provided in an ATM switch control portion 3 A. The connection setting control portion 733 controls setting of connection of the preferential SVC, for which the required band is preliminarily set as the band acquiring data.
[0075] By this, since the band required for the preferential SVC is constantly acquired and guaranteed, the preferential SVC can be set and deleted as required by the connection setting control portion 733 . For the connection of the SVC of ABR or UBR which does not require the fixed band and is not controlled by the connection admission control (CAC) portion 24 and the connection band controller 25 , when the preferential SVC is unnecessary, namely when connection for the preferential SVC is not established, the band reserved for the preferential SVC is available for the SVC of ABR or UBR. Thus, the finite connection band of each ATM circuit port can be effectively used. On the other hand, when the preferential SVC becomes necessary, namely, when the connection for the preferential SVC is to be established, the band for the preferential SVC is acquired cutting into the band for the SVC of the ABR or UBR. Therefore, even when setting of connection for the preferential SVC is established later, communication of the preferential SVC can be established normally.
[0076] Next, discussion will be given for the fourth embodiment of the ATM connection band control system according to the present invention with reference to FIG. 8 . The shown embodiment is differentiated from the ATM switch control portion 3 in the first embodiment shown in FIG. 2 , in that a connection-setting portion 833 of an ATM switch control portion 3 B is provided. Also, a memory 762 for storing band acquiring data of the preferential connection in a buffer control memory 26 B and a memory 763 storing acquired band data of PVC or SVC are differentiated from the memory 262 storing the band acquiring data of the preferential SVC and the memory 263 storing the acquired band data of SVC.
[0077] The connection-setting control portion 833 of FIG. 8 controls setting of the preferential connection, for which the band required irrespective of PVC or SVC is preliminarily set as the band acquiring data.
[0078] By this, since the band necessary for the preferential connection is constantly acquired and guarantee, the preferential. connection irrespective of PVC or SVC can be set and deleted as required by the connection-setting control portion 833 . For the connection of the SVC of ABR or UBR which does not require the fixed band and is not controlled by the connection admission control (CAC) portion 24 and the connection band controller 25 , when the preferential SVC is unnecessary, namely when connection for the preferential SVC is not established, the band reserved for the preferential SVC is available for the SVC of ABR or UBR. Thus, the finite connection band of each ATM circuit port can be effectively used.
[0079] On the other hand, when the preferential SVC becomes necessary, namely, when the connection for the preferential SVC is to be established, the band for the preferential SVC is acquired cutting into the band for the SVC of the ABR or UBR. Therefore, even when setting of connection for the preferential SVC is established later, communication of the preferential SVC can be established normally.
[0080] As set forth above, by cooperating the connection band control and the connection setting control, the band for the preferential connection can be constantly and certainly acquired and guaranteed for the preferential connection. Also, for the connection of ABR or UBR which does not require preferential connection or when the preferential connection is not established, the band becomes open to the ABR or UBR to permit effective use of finite number of connection bands in each ATM circuit port.
[0081] On the other hand, by managing the connection setting control by a schedule or the like, the necessary band is used for establishing connection only in a time zone which requires preferential connection, and in the time zone where the preferential connection is not required, control for temporarily deleting connection is performed in the connection setting control. The connection setting control is also cooperated with the connection band control, during the period where the preferential connection is temporarily deleted, the connection setting demand for the connection requiring the fixed band is not admitted, and for the connection which does not require the fixed band, the band is opened to more effectively use the finite connection bands of each ATM circuit port.
[0082] As set forth above, in the shown embodiment, by preliminarily setting the connection band for the preferential SVC in the ATM network as the band acquiring data to perform connection band control including the band acquiring data, and by cooperating with the connection admission control, during connection admission control for the SVC which has low preference and reservation of the bans is unnecessary, the band for the preferential SVC can be certainly acquired and guaranteed. On the other hand, at the same time, for the preferential SVC, connection band control including the connection admission control can be realized under the condition where the band for the preferential SVC is constantly acquired and guaranteed irrespective whether the connection is currently established or not to more effectively use the finite connection bands of each ATM circuit port.
[0083] For example, for the connection of the SVC having high preference (preferential SVC), even when established connection is temporarily broken by certain failure to open the band, the connection admission control is realized in the condition where the connection band of the preferential SVC is certainly acquired and guaranteed, for the connection setting demand of the SVC of low preference which connection of the preferential SVC is held broken. Furthermore, even when the connection setting demand of the preferential SVC is issued the acquired and guaranteed bans is again demanded to ensure establishment of connection again.
[0084] As set forth above, in accordance with the present invention, the first effect is capability of connection band control in a range where the band for the SVC of high preference and being set the band preliminarily, is acquired and guaranteed constantly upon connection admission control for the SVC of low preference and acquiring of the band being not required, by preliminarily setting the connection band of the SVC having high preference (i.e. preferential SVC) which is one of CBR, rt-VBR or the nrt-VBR requiring fixed band, and by performing connection band control with as band acquiring.
[0085] The second effect is that, with the band setting for the SVC having high preference as set forth in the first embodiment, upon connection admission control for the SVC which does not require reservation of control, and by performing connection band control in the range where the band for the SVC for which the band is reserved is constantly acquired and guaranteed, for the SVC of high preference, connection band control including connection admission control can be performed under the condition where the band for the SVC of high preference is constantly acquired and guaranteed irrespective whether the connection of the preferential SVC is established or not.
[0086] Although the present invention has been illustrated and described with respect to exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omission and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific embodiment set out above but to include all possible embodiments which can be embodied within a scope encompassed and equivalent thereof with respect to the feature set out in the appended claims.
|
An asynchronous transfer mode connection band control system in a system for transmitting and receiving an asynchronous transfer mode cell utilizing an asynchronous transfer mode network, has data storage means for storing a connection band of a preferential switched virtual connection having high preference in the asynchronous transfer mode network being stored preliminarily as a band acquiring data and storing acquired band data of a switched virtual connection currently established connection, and connection band control means for performing control of connection band on the basis of a total number of bands derived by a sum of the band acquiring data and the acquired band data stored in the data storage means.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a device for sorting hosiery, and more particular to a pneumatic conveying system that interfaces with a multi-station sock sewing machine.
2. Description of the Prior Art
Conventionally, hosiery are knit in the form of elongated circular tubes with the toe end open. According to prior art, the stockings are delivered, in containers, to a seaming station. The operator of the seaming station then picks up the stockings and passes them through a sewing machine to trim and close the open toe, while the stockings are turned inside-out. Stockings are then delivered to an inspection station where they are visually inspected. After inspection, individual stockings are everted pneumatically through a hollow inspection form and delivered to a collection point. As delivered, they are in the rightside-out condition.
Some time ago, it was recognized that the repeated manual operations recited above increased the cost of hosiery by slowing down production and increasing the number of "seconds" due to imperfections caused by the inspection process, such as pulled threads. Thus, devices were developed in which a combination turning and inspection form is moveable from the inspection station to a sewing station to permit the toe of the stocking to be seamed while it remains on the form. However, the use of these devices were not entirely satisfactory because hosiery had to be inspected before the seaming operation, leading to some undetected defects. In some devices, the operator had to turn and inspect the hosiery on the form and wait for the form to deliver the hose to the seaming station and return before the next stocking can be placed on the form.
U.S. Pat. No. 3,486,471 (De Spain) describes an improved method and device wherein the hosiery is turned on a form at a first work station by a first operator, and then advanced on the form to a second work station where a second operator closes the toe while it remains on the form. The hosiery is then returned to the first work station, where the seamed hosiery is inspected by the first operator and subsequently everted through a hosiery receiving passage in the form. A duct system, connected to a source of pneumatic pressure differential, was provided to establish a flow of air through a hosiery receiving passage when they are at the first work station.
U.S. Pat. No. 3,420,196 (Edwards et at.) deserves a method and means for processing tubular fabric articles in which ends of the articles are dosed in an integrated operation that is capable of high-speed production that requires relatively little handling, reducing labor requirements and the danger of damage of the articles during handling. Tubular fabric articles are placed on forms at a receiving station, where an end of the article is closed while it remains on its form. The form advances through an end closing station, and articles are removed from the forms at a removal station. Articles may be inspected while they are on the forms at the receiving station, and everted as they are removed from the forms after end closing. This device comprises conveyor means that convey article carrying forms through the receiving end closing and removal stations, with the forms arranged for receiving open-ended articles at the receiving station such that open ends of the articles are disposed at the outer ends of the forms for closing of the article ends by closure means in the end closing station while the articles remain on the forms as the form advance through the end closing station to the removal station at which removal means remove the closed end articles from the forms.
The forms are hosiery inspecting and turning forms disposed to extend laterally from a conveyor means for ready access for mounting the hosiery articles thereon and to present the articles ends conveniently for horizontal feeding to the closure means, which is a sewing machine disposed adjacent the outer ends of the forms for feeding the toe ends of the articles through as the forms advance continuously through the end closing station. Inspection is accomplished on the inspecting and turning forms, where the toes are guided into the sewing machine. Then the toes are closed and the articles are everted and removed from the forms at the removal station. Two operators are required, one at the receiving station and another at the toe closing station.
However, prior art devices suffer from a number of disadvantages. For example, styles cannot be mixed; they must be fed into the system one style at a time. Because two or more styles are often produced at the same time in hosiery plants, it would be advantageous to be able to feed more than one style into the system at once, and to sort the different styles from each other and from seconds. Another disadvantage of the prior art devices is that seconds must be removed before the seaming operation, as there is no way to sort seconds or styles after they enter this operation. Moreover, the prior art devices for collecting and sorting socks are not fast enough for the ten-tube turrets used at today's speeds. It would thus be advantageous to provide a sock sorter that permitted a plurality of styles, as well as seconds, to enter the seaming operation while being sorted later. Furthermore, it would be advantageous to provide a system that has a plurality of separating and sorting functions. Thus, a hosiery factory could run at least two styles of hosiery at one time, while allowing seconds to be finished, sorted, and counted in the same run, at maximum efficiency, and with maximum return on salvaged seconds.
Today, machines such as "Detexomat" machines are used in the sock industry for the sole purpose of closing the toe of a sock. An operator loads a sock onto a tube. The operator also has the opportunity to remove the sock in the event the sock is not of first quality. However, when the operator removes the sock from the cycle, the machine must continue through its cycle empty. The sewing machine still runs, even though there are no socks to be sewn. While this is going on, the operator misses three socks because of the break in rhythm and removing the seconds sock from the tube. While each sock factory has its own system of handling seconds, generally the socks are collected, counted, and boxed. Meanwhile, a report must be made, and the socks must be tracked in the warehouse. (A box of sock seconds presently has a value of about $200.00 to $250.00.)
At some point, the accumulation of these seconds becomes a great problem. The problem is so great that an operator or operators must be taken off producing first quality production to seam the accumulated seconds. The operator replaces the sock on the tube, even though it was previously removed from the tube only a fraction of a second from the time it would have been seamed had it not been removed as a second.
Thus, although a satisfactory first quality sock line is produced by this method, the cost to produce the second quality line (in energy and manpower) is greater than the cost to produce the first quality line.
There is thus a need for an add-on device for a toe closer that can track a sock through the toe closer, and then, in accordance with a signal provided by the operator prior to the sewing step, direct the flow of the sock to an appropriate destination, in accordance with the determined quality of the sock and the style.
BRIEF DESCRIPTION OF THE INVENTION
There is thus provided, in accordance with the invention, a device designed to work in concert with a parent or host machine. The device comprises a logic controller, a diverter assembly, at least a first and a second discharge conduit, and a manifold. The logic controller is preferably a programmable logic controller having sufficient capacity to manage the desired number of options. The diverter assembly preferably comprises a pneumatic gate or flap valve arrangement allowing flow to go straight through or to be diverted out a side port. By stacking additional valves, additional options can be added. The diverter assembly valves may be operated by air valves and air cylinders that are activated by the logic controller. Alternately, solenoids, rotary solenoids, linear motors, or other similar means may be used to activate the diverter valve or valves.
The manifold comprises a device having a plurality of outlets equipped with a butterfly valve. When a photoswitch cell on a discharge conduit detects the presence of a sock being sent to a sock discharge device at the end of the discharge conduit, a signal is sent into a time delay, which is preferably within the logic controller although it may also be implemented in other conventional ways. Debounce circuitry is preferably employed to assure that only one pulse per sock is transmitted. The delayed signal causes a butterfly valve to close, allowing the sock to be released from the sock discharge or separator device, separating it from the source of vacuum, and allowing it to fall into a collection bin. Counters and alarms may be added to count the number of socks falling into each collection bin and to alert the operator when the desired number of socks has been collected in each bin.
It is thus a object of the invention to provide a device that provides for a plurality of configuration options, including the sorting of multiple styles.
It is thus a further object of the invention to provide a device that permits multiple styles of socks to be sorted from a single run of combined styles in a sock factory.
It is an additional object of the invention to provide a device and a method for sorting and counting first quality socks and seconds from a run without interrupting the run to remove the seconds prior to the seaming of the toes of the socks.
It is an additional object of the invention to provide a device and a method for sorting and counting first quality socks and seconds from a run of multiple styles of socks without interrupting the rhythm to remove the seconds prior to the seaming of the toes of the socks.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are views of a host machine to which an inventive adapter has been operatively installed. FIG. 1A is a left side view and FIG. 1B is a partially cut-away front view of the host machine and adapter. Only a portion of the adapter is shown. The physical layout of the adapter may be altered to fit a particular workspace, and thus, the layout shown in this and the other figures is by example only.
FIG. 2A is a schematic representation of the turret assembly of the host machine. FIG. 2B is a electrical block diagram of a preferred embodiment of the invention.
FIG. 3A is a schematic representation of the pneumatic flow through a preferred embodiment of the invention. FIG. 3B is a detail representation of the sock separator device shown in FIG. 3A.
FIG. 4 is a top view of a manifold valve assembly employed in a preferred embodiment of the invention.
FIG. 5 is a partially cut-away perspective of the valve in FIG. 4 showing the operation of a butterfly valve.
FIG. 6 is a partially cut-away perspective view of a swing gate valve used in the diverter assembly used in a preferred embodiment of the invention.
FIG. 7A and 7B are portions of a single logic block diagram indicating the operation of a logic controller used in the preferred embodiment of the invention.
FIG. 8A-8J show the ladder logic problem.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1A is a left side view and FIG. 1B is a partially cut-away front view of a Detexomat Turn Sew machine, manufactured by Detexomat Machinery, Ltd., Wycombe, Buckinghamshire, England. A similar device is described in detail in U.S. Pat. No. 4,903,621 to Hodges et al., assigned to Detexomat Machinery, Ltd., Buckhamshire, England, the disclosure of which is incorporated into the present specification by reference. Host machine 120 has a rotating turret 122 comprising a plurality of positions, including a loading position 124 and an inspection position 126. A vacuum supply conduit 132, which is part of host machine 120, provides a source of vacuum for the discharge of socks on turret 122. Most modern facilities now have abandoned the vacuum pumps which reside within the host machine and instead, use a central unit (not shown), which reduces heat and noise. (The inventive system adapts to this system using a manifold 56, which not shown in FIG. 1A or FIG. 1B, but which described later.) Socks are discharged from the turret after sewing through sock discharge line 136.
In accordance with the invention, a sock discharge assembly 12 (best seen in FIG. 1A) is provided. A plurality of flow splitters 14, 16 are provided in the discharge assembly, preferably within the host machine, but they may also be installed remotely. The flow splitter provide pneumatic communication with discharge tubes 18, 20, and 24, depending upon the fluid connection established by the logic controller 26, which is also provided in accordance with the invention. The sock discharge assembly is preferably retrofitted inside a portion of the host machine 120, although it may alternately be provided outside the cabinet. It is to be understood that, while two flow splitters 14, 16 are provided in this embodiment, additional flow splitters could be provided, along with corresponding additional discharge conduits. The embodiment described here is adequate to sort and count two styles of socks, as well as separating and counting seconds. However, it will be recognized that, for sorting and counting n styles as well as separating seconds, n flow splitters are required, and n+1 discharge conduits.
Also provided in accordance with the invention are foot switch 30 and hand switch 32 which are electrically connected to logic controller 26. These switches are preferably located so that an operator of host machine 120 may conveniently operate switches 30 and 32.
Host machine 120 lacks the ability to run mixed styles and to complete seconds all in the same cycle. When adapted in accordance with the invention, host machine 120 can run multiple styles, and can complete socks found to have blemishes while still on the host machine 120. The different styles can be counted and separated into appropriate containers; seconds are also counted and separated into their own container. Thus, no secondary handling, storage, reverse flow, or secondary paper work to keep track of seconds or different styles is required. It will, of course, be recognized by one skilled in the art that the invention is not limited to the particular host machine 120 described herein, and can be readily adapted to other models of host machines.
Host machine 120 has a work holding device comprising a rotatable turret 122 having ten working stations, schematically illustrated in FIG. 2A. Rotatable turret 122 rotates about a central axis. Each of the ten stations is equipped with a tube (not shown in FIG. 2A) which holds the sock while it is being rotated to the ten work stations. While the host machine 120 described in conjunction with this embodiment of the invention has ten turret positions, it will become clear that the invention can be easily adapted by one skilled in the art to a machine having a different number of turret positions.
To operate the host machine 122, the operator pulls a sock over the end of a tube in position 124, the first position of turret 122. The host machine 120 indexes on-tenth of a turn. When the first sock advances to position 126, corresponding to the third turret position, the operator inspects the sock. The sock is sewn in the fourth turret position 128, and unloaded in the ninth turret position 129. (Nothing of importance to the invention is done on the other turret positions, and the tenth turret position has no function.) As will be explained below, in the embodiment discussed here, the style selection is made by the operator when the sock is at the first turret position (i.e., position 124), while the decision to divert the finished sock to "seconds" is made at the third turret position (i.e., position 126).
FIG. 2B is a partial electrical block diagram of the inventive sock sorting device. An index detection means 28 a temporary contact foot switch 30, and a temporary contact hand switch 32 are connected to logic controller 26 via a cable harness 40. The index detection means 28 may be any means to detect the indexing of turret 122. Satisfactory devices that may be used as index detection means 28 include, but are not limited to, a limit switch, or any type of SPST normally open contact or proximity switch. Typically, foot switch 30 is used to sort one style of sock from another, while hand switch 32 is used to sort seconds from first quality socks. Logic controller 26 (preferably a model ICMBB-13 "Baby Bare Bones" single board expandable computer from Divelbiss Corp., Fredrictown, Ohio although other computer boards and even discrete logic could be used) is provided with a pair of counters 52, 54, which, together with a pre-existing counter 134 normally provided as a part of host machine 120, are actuated by photosensors 36, 38, and 34, in sock discharge conduits 20, 24, and 18, respectively, thereby keeping count of the number of each type of sock discharged from the invention. Counters 52 and 54 are preferably provided with a button pad (not shown) for resetting and for entering a value which may be compared with the current count to sound an alarm or buzzer 218 (which may be model "Squire 11000" counters from Veeder-Root, Curnee, Ill., which are used in a preferred embodiment of the invention) when a collection bin (not shown in FIG. 2B) has a predetermined number of socks in it. (Alternately, the predetermined number may be preprogrammed rather than entered by the operator.) The reset function may be provided with a key or other security device to ensure that the counts would be reset by a lead person rather than an operator. A panel switch 215 on logic controller 26 may be provided to run production through a single sock style in a manner to be explained later. Also provided in the preferred embodiment are an on-off switch 216, and a fuse 217 for electrical protection. A buzzer or alarm 218 may be provided for alerting an operator when a counter has reached a predetermined or preprogrammed value. Pneumatic diverter valves 44 and 46 are controlled by logic controller 26. Diverter valves 44 and 46 control socks in conduits 20 and 24 respectively, in a manner to be described below. Similarly, butterfly valves 48 and 50 also are controlled by logic controller 26 and are also associated with conduits 20 and 24, respectively, as will be seen below.
FIG. 3A is a schematic of the pneumatic flow through the inventive system. Air supply 99 provides an air source for the operation of valves 44, 46, 50, 48, and 43. The flow of vacuum through the conduits is generally indicated by arrows V. Vacuum is supplied via vacuum supply conduit 132. Sock discharge line 136, through which all socks everted from turret 122 (not shown in FIG. 3A) pass, enters valve 16, where, depending upon the state of pneumatic valve 46, socks are diverted either to discharge conduit 24 or intermediate conduit 15. Socks passing through intermediate conduit 15 next pass through a second valve 14, where, depending upon the state of pneumatic valve 44, they are either diverted into discharge conduit 20 or passed to discharge conduit 18. Depending upon the discharge conduit 18, 20, or 24 into which a sock is diverted, one of detectors 34, 36, or 38, respectively, detects the sock. Preferably, detectors 34, 36, and 38 are photoswitch detectors that can detect a sock through a clear portion of the respective discharge conduits, and that send a signal to controller 26 (not shown in FIG. 3A) so that the sock can be counted. The discharge conduits 18, 20, and 24 are each terminated in a sock separator drop box 138A, 138B, and 138C, respectively, of conventional design, such as those manufactured by Templex Corp. of High Point, N.C. (Drop box 138C is shown in more detail in FIG. 3B.) Vacuum for the drop boxes 138A, 138B, and 138C are provided by vacuum return conduits 18A, 20A, and 24A, respectively, each of which connect to a vacuum supply manifold 56. Between each of the vacuum return conduits 18A, 20A, and 24A and manifold 56, a separate butterfly valve 58, 60 and 62, respectively, is provided. Butterfly valves 58, 60, and 62 are connected to returns 18A, 20A, and 24A via drop boxes 138A, 138B, and 138C, respectively. Butterfly valves 58, 60, and 62 are controlled by pneumatic valves 43, 48, and 50.
FIG. 4 and FIG. 5 show detailed views of one of three manifold valve assemblies 58, 60, 62. Although only one manifold valve 58 is shown, the other valves 60, 62 are of similar construction. Butterfly valve disk 82 (shown only in a cut-away portion of FIG. 5) is operatively connected to valve shaft 80. Valve shaft 80 is rotated by a sprocket 64, which engages a chain 65 connected to a rod 76 of pneumatic cylinder 74 through a cylinder rod clevis 78. The other end of the chain is attached to a fixed position by spring assembly 68. Pneumatic cylinder 74 is controlled by a valve (not shown in FIG. 4 or FIG. 5), which is, in turn, controlled by a time-delayed signal from a sock detector 34, 36, or 38, the delay preferably being provided by logic controller 26. Outlet 59 is provided for mounting a vacuum return line 24A, which is controlled by manifold valve 58.
FIG. 6 shows a detailed view of one of valves 14 or 16, both of which are represented by the valve shown in FIG. 6. The valve comprises an adapter block 94 on either side of valve 14 (or equivalently, 16). These adapters serve to interconnect circular conduit, such as intermediate conduit 15, with square conduits such as is used in the body of valve 14. Valve 14 comprises a piece of such square conduit 17 between two adapter blocks 94. A branch 98 is provided off conduit 17. Normally, a gate 84 is in position as shown. However, gate 84 can be rotated into conduit 17 by pivoting around shaft 86, thereby deflecting a sock arriving from the bottom of FIG. 6 through bypass 98. Shaft 86 is rotated by a pneumatic cylinder 92 activated through an air source 99 controlled by an electrically controlled valve 44, which is itself controlled by logic controller 26 (not shown in FIG. 6). When shaft 86 is rotated, cylinder arm 91 moves cylinder clevis 90, causing bell crank 88 to rotate shaft 86.
It should be understood that pneumatic cylinders 92 and 74 described and their associated components may be replaced by other controllable assemblies, such as assemblies including solenoids, that can provide equivalent motions.
FIGS. 7A and 7B are logic diagrams indicating the operation of logic control 26 in the preferred embodiment. It is to be understood that the logic for logic controller 26 may be implemented either directly in hardware, or in software or firmware. For discussion purposes, let us consider four cases encompassing two different styles (e.g., style A and style B) and first and second quality socks of both styles.
Consider first the case in which a sock of style B is being seamed, and this sock is of second quality. In this case, the operator would operate both style change foot switch 30 and "seconds" pushbutton 32. Referring to FIG. 2A and FIG. 7B, as the sock is placed on the first turret position 124, the operator will depress the "style" foot switch 30, which enters a logical "1" (or any equivalent indication) into the first stage of 9count shift register 404. In the preferred embodiment, the style foot switch 30 need not be held down, as the first stage of shift register 404 latches in a "1" whenever the style foot switch is momentarily depressed. Each time turret 122 indexes, index indicator 28 outputs a signal that causes the 9-count shift register to shift its contents by one unit; thus, when the sock is rotated to turret position 2, the logical "1" in the first stage of the 9-count shift register 404 is shifted into the second stage of shift register 404, and the first stage is again ready to receive a 37 1"--which it will receive if and only if style foot switch 30 is pressed before the next indexing of turret 122. The next indexing operation moves the "1" in the second stage of shift register 404 into the third stage and places the sock in the third turret position 126, where the sock is inspected. Because in this example the sock is rejected to seconds, seconds pushbutton 32 is depressed, latching a logical "1" in the first stage of 7-count shift register 402. In the next indexing operation, the sock moves to the fourth turret position 128, where it is seamed. In addition, the "1" in 9-count shift register 404 moves to the fourth stage of that register and the "1" in 7-count shift register 402 moves to the second stage of that shift register. Each subsequent indexing operation advances the sock one turret position and the "1" in each shift register 402, 404 one position, until the sock is on the ninth turret position 129, and is ready to be everted and passed through sock discharge line 136. At that point, the "1" in 7-count shift register 402 is in its final position, causing shift register 402 to output a signal to diverter valve C solenoid 46, which operates pneumatic piston 92, causing valve 16 to divert the sock into discharge conduit 24. Similarly, the "1" in 9-count shift register 404 is in its final position, causing shift register 404 to output a signal to diverter valve B solenoid 44, which operates pneumatic piston 93, causing valve 14 to divert flow from conduit 15 into discharge conduit 20. However, since any sock entering sock discharge line 136 will be diverted into discharge conduit 24 rather than entering conduit 15, it will be seen that the "seconds" switch 32 in this embodiment has priority over the "style" switch 30, which is preferable in most commercial environments.
It will be readily apparent to one skilled in the art that the shift register lengths are selected to "remember" the status of a sock at a specific turret position until the sock is in a turret position from which it is evened and discharged. Thus, the length of the shift register may be modified to meet the requirements of other host machines, if necessary.
Referring to FIG. 3A, FIG. 3B, and FIG. 7A, the sock going through discharge conduit 24 passes through detector 38, which is a photoswitch detector in the preferred embodiment. At least a portion of discharge conduit 24 around which detector 38 is located is transparent, allowing a light beam to be interrupted when a sock passes through conduit 24 at the point at which detector 38 is located. When detector 38 detects a sock, the signal from detector 38 is "debounced" by conventional circuitry to ensure that a single indication is received from detector 38. The debounced signal from detector 38 causes sock counter 54 to advance one count. The count in sock counter 54 is then compared with a preselected and/or preprogrammed value, and alarm 218, which may be an audible alarm, is sounded if the count matches the preselected and/or preprogrammed value. (Alarm 218 is shown as three separate alarms, although its function can be supplied with only one alarm shared by each of the counters 408, 410, and 54. Note that alarm 218 may generally be connected to counter 54, which is part of host machine 120, through conventional circuitry.) Meanwhile, the sock continues in its path from detector 38 to sock separator drop box 138C. After a delay 412 (about 0.5 seconds in the preferred embodiment, the time delay, if any, being dependent upon the time it takes for a sock to pass from detector 38 to sock separator drop box 138C), a signal is sent to vacuum valve selector switch 50, which momentarily operates pneumatic cylinder 77, which closes butterfly valve 62, thus momentarily cutting the vacuum to drop box 138C. A door in sock separator drop box 138C, which is of a conventional design, holds the sock in a compartment within drop box 138C until the vacuum is cut off, which causes the door to open and allows the sock to drop from sock separator drop box 138C into collection box 100C, which holds second quality socks. When the vacuum resumes, the door in the sock separator drop box 138C closes, and it is ready to receive another sock.
If the sock had been of style A rather than style B, but still of second quality, the operator would not have pressed style foot switch 30 when the sock was on the first turret position, and thus a logical "0" would have been entered into 9-count shift register 404. As a result, when the sock was discharged from the ninth turret position, diverter valve solenoid 44 would not have been operated, and therefore, diverter valve 14 would have allowed passage from intermediate conduit 15 into sock discharge conduit 18. However, the sock would never reach intermediate conduit 15, because it would be diverted by diverter valve 16 into sock discharge conduit 24 as a result of the operator pressing the "seconds" pushbutton 32 at the appropriate time. Again, by operatively connecting the "seconds" switch to the diverter valve that is first in the path of the sock as it is discharged, the seconds switch 32 has priority over the style selection of style footswitch 30, and thus all seconds are diverted through discharge conduit 24.
Let us turn our attention now to socks of first quality. If the sock is of style "A", neither the seconds pushbutton 32 nor the style foot switch 30 will be depressed by the operator. Thus, "0" will be input to both shift registers 402, 404, and when the sock is ready to be everted and discharged at the ninth turret position 129, neither of the diverter valve solenoids ,14, 46 will be operated. Thus, diverter valve 16 will allow a sock in sock discharge conduit 136 to pass into intermediate conduit 15, and into diverter valve 14. Diverter valve 14 will allow the sock to pass into sock discharge conduit 18, and past detector 34, which is similar to detector 38. The detector 38 output is debounced and counted in a sock counter 408, which may be part of the host machine 120. When this count equals a predetermined or preprogrammed value, an alarm 218 is provided. This alarm corresponds to the predetermined or preprogrammed number of socks being sent to box 100A. Meanwhile, after a 0.5 second time delay 406, a signal is sent to vacuum valve selector switch 43, which operates pneumatic cylinder 74, causing valve 58 to cut off vacuum to sock collector drop box 138A, allowing the sock to drop into box 100A.
If the sock is of style "B," the operator will press style footswitch 30 when the sock is on the first turret position 124, thereby entering a logical "1" into 9-count shift register 404. The operator, however, will not press seconds pushbutton 32 when the sock is indexed to the third turret position 126, and thus a logical "0" will be entered into the 7-count shift register 402. The sock will be seamed in the fourth turret position 128. By the time the sock reaches the ninth turret position 129, it is ready to be everted and discharged. The "1" in 9-count shift register 404 will cause the diverter valve solenoid 44 and thus cylinder 93 to operate, diverting a sock passing from intermediate conduit 15 and into valve 14 to sock discharge conduit 20. Since a logical "0"0 was input to 7-count shift register 402 when the sock was on the third turret position 126, a "0" will be output from shift register 402 when the sock is on the ninth turret position 129 and diverter valve solenoid 46 will not operate when the sock is everted. Thus, the sock, which is discharged through sock discharge conduit 136, will pass through diverter valve 16 and into intermediate conduit 15. The sock will then pass into diverter valve 14, which is operated by solenoid 44 and cylinder 93 to divert the sock into sock discharge conduit 20. Similar to the other examples above, the sock is detected by detector 36, which causes counter 52 to increment, and, if appropriate, an alarm 218 to sound. Also, after a 0.5 second delay 410, vacuum valve selector switch 48 will operate, causing butterfly cylinder 75 to cause valve 60 to cut off vacuum to sock collector drop box 138B, allowing the sock to drop into box 100B.
In normal operation, only one sock at a time is passing through the sorting apparatus. Thus, indexing, which is controlled by the operator of host machine 120, is controlled so that a sock can complete its path into sock discharge conduit 136 and out of one of the sock collector drop boxes 138A, 138B, 138C before the turret 122 is indexed again. Normally, with sufficient vacuum and reasonably short sock conduit travel lengths, the maximum indexing rate will not be limited by the inventive apparatus, but rather by the rate at which the operator can operate host machine 120 and load socks on the first turret position 124. Because of the memory provided by the shift registers 402, 404, a turret 122 can have socks at each turret position from the first to the ninth (the tenth turret position is not used in the host machine 120 described), and each of the socks may be directed to the proper collection box 100A, 100B, 100C, without interrupting the rhythm of the operator.
A selector switch 216 may be provided to save vacuum, and also to allow operation when, for example, collection box 100A is filled, and it is acceptable to divert all further first quality socks to collection box 100B until collection box 100A is unloaded. Unlike foot switch 30, selector switch 216 is not a momentary contact switch. Referring to FIG. 7A, and FIG. 3A, the output of selector switch 216 is "or-ed" with the output of delay 406. Thus, if selector switch 216 is thrown, a signal will always be present at the input to vacuum valve selector switch 43, which will prevent vacuum from being supplied to sock collector drop box 138A and the associated conduit 18, thereby allowing a 33% savings of vacuum, whereby a lesser vacuum volume can operate the apparatus to permit selection between collection boxes 100B and 100C; i.e., first and second quality socks. Referring to FIG. 7A, FIG. 7B, and FIG. 3A, the signal from selector switch 215 (shown as coming from FIG. 7A by an indicator 414 showing the connection between parts on FIGS. 7A and 7B) is also "or-ed" with diverter valve solenoid 44, which, through air supply 99, operates pneumatic cylinder 93, which controls diverter valve 14. Thus, when switch 216 is thrown, all socks entering intermediate conduit 15 are diverted by diverter valve 14 into conduit 20, and thus into box 100B. Because diverter valve 16 is placed before diverter valve 14 in the path of the discharged socks, it is still possible to operate seconds pushbutton 32 to control the rejection of seconds, even when selector switch 216 is thrown. Selector switch 216 thus provides simplified operation when the sock styles have been presorted prior to seaming.
It is expected that logic controller 26 may preferably be provided as a single-board computer system, as described above. If the Divelbiss ICMBB-13 described above is used, an M2732AFI may be programmed in a Divelbiss "SMART" programmer with the ladder logic program following this description and inserted in the EPROM memory socket of the ICMBB-13 board to cause the logic controller 26 to operate in accordance with the invention.
It will thus be seen that the invention provides a pneumatic conveying system that interfaces with a multi-station sock seaming machine, and which simultaneously provides sorting capability for more than one style of sock and separation of seconds from first quality runs without interrupting a run and without requiring the removal of seconds for later seaming. Many modifications of the invention will be recognized as being within the capabilities of one skilled in the art. For example, by adding additional diverter valves and switches, it would be possible to expand the sorting capabilities of the invention. Moreover, it will be readily apparent to one skilled in the art that the lengths of the shift register memory elements may be adjusted to meet the requirements of different host machines having different numbers of turret positions or workstations, or different positions where socks are loaded, seamed, or discharged. It will also be recognized that a portion of the logic controller's functions may be embedded within a controller which may be supplied as a part of the host machine itself. Many other modifications will be apparent, and thus, the scope of the invention should not be considered as being limited only to the embodiment described above, but rather, the scope should be determined by reference to the claims at the end of this specification.
The ladder logic program referred to above is seen in FIGS. 8A-8J.
|
An adapter working in concert with a parent or host machine to divert socks of different styles or quality into separate collection containers, including a logic controller, a diverter assembly, at least two discharge conduits, and a manifold. The diverter assembly is pneumatically connected in series with the sock discharge outlet of the host machine. Depending upon a selection entered into the logic controller by an operator, a sock on a rotating turret on the host machine may be designated, at predetermined turret positions, to be of a particular style, or to be of second quality. The entry is entered into the logic controller, where it is remembered until the sock is ready to be everted and discharged. A index detection device is provided to indicate indexing of the turret to the logic controller. When the sock is in the discharge position, the logic controller operates the diverter valves in accordance with the choice or choices made earlier by the host machine operator, to cause the diverter valves to divert the sock into one of several conduits. The sock passes a detector in the selected conduit, which causes a counter for that style of sock (or for second quality socks) to increment, and which, after a time that permits the sock to be collected in a sock separator device, causes the vacuum in the selected conduit to be removed. Removal of the vacuum permits the sock to drop into a collection area or bin. The adapter permits uninterrupted seaming operations to occur, even though different styles and qualities of socks may be present in the run. The run need not be interrupted when a second quality sock or a sock of a different design is loaded or detected on the host machine.
| 3
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device wherein the laminated structure of nitride semiconductors is formed, and more specifically, to a semiconductor device that can ensure sufficient capacitance and withstand voltage without enlarging a chip area.
2. Background Art
A nitride semiconductor is the generic term for gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InM), and mixed crystals composed of these nitrides. Generally, the nitride semiconductor is mechanically robust and chemically stable, and has high thermal conductivity and excellent heat dissipation properties. Therefore, a semiconductor element fabricated using a nitride semiconductor multilayer film structure, for example, an Al x Ga 1-x N/GaN high electron mobility transistor (HEMT) is considered to be applied to a high output high-frequency element. Therefore, a large number of trial products of AlGaN/GaN HEMTs have been reported.
A circuit using an AlGaN/GaN HEMT can be used as a monolithic microwave integrated circuit (MMIC) in the same way as other high-frequency transistors. For fabricating an MMIC, the structure and the fabricating method of passive elements, such as a resistor, an inductor, and a capacitor, other than transistors are important. In conventional metal insulator metal (MIM) capacitors, a silicon nitride (SiN x ) film is deposited on an underlying metal layer by a chemical gas-phase growing method, and is used as an insulating film.
The breakdown electric field of the SiN x film is not more than about 6 MV/cm (for example, refer to N. Inoue, Ippei Kume, Jun Kawahara, Shinobu Saito, Naoya Furutake, Takeshi Toda, Koichiro Matsui, Takayuki Iwaki, Masayuki Furumiya, Toshiki Shinmura, Koichi Ohto, and Yoshihiro Hayashi, Jpn. J. Appl. Phys. 46, 1968 (2007)). Therefore, the breakdown voltage of an MIM capacitor using a normal SiN x film of a thickness of 150 nm is about 90 V, and is insufficient for withstanding voltage as a capacitor for the MMIC of an AlGaN/GaN HEMT. When the SiN x film is thickened in order to make the break down voltage higher, the capacitance is lowered in proportional to the film thickness; therefore, the area of the capacitor must be enlarged. If the sufficient capacitance and withstand voltage are to be ensured, a problem of enlarged chip area is caused.
SUMMARY OF THE INVENTION
To solve the above-described problem, it is an object of the present invention to provide a semiconductor device that can ensure sufficient capacitance and withstand voltage without enlarging a chip area.
According to one aspect of the present invention, a semiconductor device comprises an AlN layer, a GaN layer, and an AlGaN layer sequentially formed on a semiconductor substrate, wherein a first opening is formed through said GaN layer and said AlGaN layer so as to expose a part of the upper surface of said AlN layer; a second opening is formed through said semiconductor substrate so as to expose a part of the lower surface of said AlN layer, in a location facing said first opening; an upper electrode is formed on the upper surface of said AlN layer in said first opening; and a lower electrode is formed on the lower surface of said AlN layer in said second opening.
According to the present invention, a semiconductor device that can ensure sufficient capacitance and withstand voltage without enlarging a chip area can be provided.
Other and further objects, features and advantages of the invention will appear more fully from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a semiconductor device according to the first embodiment.
FIGS. 2-4 are sectional views for explaining a method of manufacturing semiconductor device according to the first embodiment.
FIG. 5 is a sectional view showing a semiconductor device according to the second embodiment.
FIG. 6 is a sectional view showing a semiconductor device according to the third embodiment.
FIG. 7 is a sectional view showing a semiconductor device according to the fourth embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
FIG. 1 is a sectional view showing a semiconductor device according to the first embodiment. The semiconductor device is an MMIC having an HEMT of an AlGaN/GaN hetero epitaxial structure and an MIM capacitor. Here, the illustration and description about the configuration of the HEMT will be omitted.
An AlN layer 12 , a GaN layer 13 , and an AlGaN layer 14 are sequentially formed on an SiC substrate 11 (semiconductor substrate). A first opening 15 is formed through the GaN layer 13 and the AlGaN layer 14 so as to expose a part of the upper surface of the AlN layer 12 . A second opening 16 is formed through the SiC substrate 11 so as to expose a part of the lower surface of the AlN layer 12 , in a location facing the first opening 15 .
An upper electrode 17 is formed on the upper surface of the AlN layer 12 in the first opening 15 ; and a lower electrode 18 is formed on the lower surface of the AlN layer 12 in the second opening 16 . An MIM capacitor is composed of the upper electrode 17 , the AlN layer 12 , and the lower electrode 18 .
The manufacturing process of the above-described semiconductor device will be described. First, as shown in FIG. 2 , an AlN layer 12 , a GaN layer 13 , and an AlGaN layer 14 are sequentially epitaxially grown on an SiC substrate 11 . Then, on the AlGaN layer 14 , a resist 19 patterned by photolithography is formed. Using the resist 19 as a mask, the AlGaN layer 14 and the GaN layer 13 are etched to form a first opening 15 . As the etching gas, for example, Cl 2 plasma having an etching ability to AlGaN and GaN is used. After conducting etching for a time estimated from the etching rate that the etching does not reach the AlN layer 12 , O 2 plasma is introduced. Since a stable AlO x layer is formed by reacting with the O 2 plasma on the surface of the AlN layer 12 , etching is stopped.
Next, as shown in FIG. 3 , an upper electrode 17 of the MIM capacitor is formed on the upper surface of the AlN layer 12 in the first opening 15 by depositing a metal film.
After the entire surface process to the surface of the wafer in the HEMT has been completed, a back-face process to the back-face of the wafer is carried out. Upon this back-face process, a lower electrode 18 of the capacitor is formed. Specifically, as shown in FIG. 4 , a resist 20 patterned by photolithography is formed on the back-face of the SiC substrate 11 . Using the resist 20 as a mask, the SiC substrate 11 is etched from the back-face by SF 6 /O 2 plasma to form a second opening 16 . When etching reaches the AlN layer 12 , the etching stops due to the difference in etching-rate ratio between SiC and AlN to the SF 6 /O 2 plasma.
Thereafter, a metal film is deposited to form a lower electrode 18 of the MIM capacitor on the lower surface of the AlN layer 12 in the second opening 16 . By the above-described steps, a semiconductor device according to the first embodiment is formed.
Here, the band gap energy of AlN is 6.28 eV at a room temperature (300 K) (for example, refer to L. Roskovcova and J. Pastrnak, Czech. J. Phys. B 30, 586 (1980)); and the static dielectric constant thereof is 9.14 (for example, refer to A. T. Collins, E. C. Lightowlers, and P. J. Dean, Phys Rev. 158, 833 (1967)). These values are both larger than the band gap energy of SiN x (not more than 5 eV), and the static dielectric constant thereof (not more than 7). The breakdown voltage generally elevates in proportional to second to 2.5th power of the band gap energy (for example, refer to J. L. Hudgins, J. Electron. Mater. 32, 471 (2003)). In the case of AlN, the breakdown field is theoretically estimated to be about 9.5 MV/cm. Therefore, when an MIM capacitor having the same capacitance and areas as the MIM capacitor using an SiN x film of a thickness of 150 nm as the insulating film is fabricated, breakdown voltage as high as about 190 V can be achieved by designing the thickness of the AlN layer 12 to be 200 nm. Therefore, sufficient capacitance and withstand voltage can be ensured without enlarging the chip area.
When the AlGaN/GaN hetero structure is epitaxially grown, an AlN layer is normally grown on the SiC substrate as the nucleation layer and the buffer layer. This is because epitaxial growth to achieve favorable crystallinity cannot be performed without the nucleation layer and the buffer layer. Therefore, by using the AlN layer as an insulating film for the MIM capacitor, the formation of a separate insulation film is not required.
Although an SiC substrate is used in the first embodiment, the present invention is not limited thereto, but a GaN substrate can also be used. In this case, if a mixed plasma of Cl 2 and O 2 is used when the GaN substrate is etched from the back-face, etching can be stopped at the AlN layer.
Second Embodiment
FIG. 5 is a sectional view showing a semiconductor device according to the second embodiment. The semiconductor device is an MMIC having an HEMT of an AlGaN/GaN hetero epitaxial structure and an MIM capacitor. Here, the illustration and description about the configuration of the HEMT will be omitted.
An AlN layer 12 , a GaN layer 13 , and an AlGaN layer 14 are sequentially formed on an SiC substrate 11 (semiconductor substrate). A first opening 15 is formed through the AlGaN layer 14 so as to expose a part of the upper surface of the GaN layer 13 . A second opening 16 is formed through the SiC substrate 11 so as to expose a part of the lower surface of the AlN layer 12 , in a location facing the first opening 15 .
An upper electrode 17 is formed on the upper surface of the AlN layer 12 in the first opening 15 ; and a lower electrode 18 is formed on the lower surface of the AlN layer 12 in the second opening 16 . An MIM capacitor is composed of the upper electrode 17 , the AlN layer 12 , the GaN layer 13 and the lower electrode 18 . However, the GaN layer 13 is thin so as not to affect the capacitance of the MIM capacitor.
In AlGaN/GaN hetero epitaxial structures, there are various structures depending on characteristics. The present embodiment is applied when the GaN layer 13 is thin so as not to affect the capacitance of the MIM capacitor. However, the AlGaN layer 14 , which generates a two-dimensional electron gas must be removed. By this configuration, the effect equivalent to the effect of the first embodiment can be achieved.
Third Embodiment
FIG. 6 is a sectional view showing a semiconductor device according to the third embodiment. Only the configuration different from the configuration of the second embodiment will be described.
The GaN layer 13 is not as thin as that in the second embodiment. By the design of the AlGaN/GaN hetero epitaxial structure, a two-dimensional electron gas layer 24 is formed in the interface between the AlN layer 12 and the AlGaN layer 14 . An impurity diffused layer 22 is formed in the GaN layer 13 by ion implantation so as to be connected with the two-dimensional electron gas layer 24 . An upper electrode 17 is formed on the impurity diffused layer 22 . An element isolating region 21 is formed in the periphery of the region to be an MIM capacitor by insulation implantation.
Since a bias can be applied to the two-dimensional electron gas layer 24 from the exterior via the impurity diffused layer 22 , the two-dimensional electron gas layer 24 functions as the lower electrode of the MIM capacitor. By this configuration, the effect equivalent to that of the first embodiment can be achieved.
Fourth Embodiment
FIG. 7 is a sectional view showing a semiconductor device according to the fourth embodiment. The semiconductor device is an MMIC having an HEMT of an AlGaN/AlN hetero epitaxial structure and an MIM capacitor. Here, the illustration and description about the configuration of the HEMT will be omitted.
An AlN layer 12 , an AlGaN layer 14 , and an AlN layer 25 are sequentially formed on an SiC substrate 11 (semiconductor substrate). An opening 26 is formed through the AlN layer 25 so as to expose a part of the upper surface of the AlGaN layer 14 . An element isolating region 21 is formed in the periphery of the region to be an MIM capacitor by insulation implantation.
In the case of the AlGaN/AlN structure, a two-dimensional electron gas layer 24 is formed in the interface between the AlGaN layer 14 and the AlN layer 25 . An impurity diffused layer 22 is formed in the AlGaN layer 14 in the opening 26 so as to be connected with the two-dimensional electron gas layer 24 . An upper electrode 17 is formed on the AlN layer 25 , and the lower electrode 18 is formed on the impurity diffused layer 22 .
An MIM capacitor is composed of an upper electrode 17 , the AlN layer 25 , and the lower electrode 18 . However, since a bias can be applied to the two-dimensional electron gas layer 24 from the exterior via the impurity diffused layer 22 , the two-dimensional electron gas layer 24 functions as the lower electrode of the MIM capacitor. By this configuration, the effect equivalent to the effect of the first embodiment can be achieved.
Obviously many modifications and variations of the present invention are possible in the 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.
The entire disclosure of a Japanese Patent Application No. 2008-052409, filed on Mar. 3, 2008 including specification, claims, drawings and summary, on which the Convention priority of the present application is based, are incorporated herein by reference in its entirety.
|
A semiconductor device comprises an AlN layer, a GaN layer, and an AlGaN layer sequentially formed on a semiconductor substrate. A first opening extends through said GaN layer and said AlGaN layer and exposes part of an upper surface of the AlN layer. A second opening extends through the semiconductor substrate and exposes a part of a lower surface of the AlN layer, in a location facing the first opening. A upper electrode is exposed on an upper surface of the AlN layer in the first opening; and a lower electrode is disposed on a lower surface of the AlN layer in the second opening.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of copending U.S. application Ser. No. 024,450, filed Mar. 11, 1987.
FIELD OF THE INVENTION
This invention relates to a method of thickening food compositions. Typically, the food products are thickened by the addition of starch. The improvement of this invention comprises the incorporation of methylcellulose into the starch and food product.
BACKGROUND OF THE INVENTION
Many food products are fluids that have historically been thickened with starches. Some examples of foods in this group include gravies, sauces, stews, cream soups, pie fillings, puddings, and the like. A number of these products are intended to be served at high temperatures. A problem that exists in traditional starch thickened fluid foods is a loss of viscosity upon heating and holding at the high serving temperatures. This loss of viscosity upon heating poses problems for food manufacturers because viscosity is one of the most important sensory attributes of these food products The products must have a fairly high viscosity at serving temperatures in order to receive consumer acceptance.
Similar to starch thickened systems, foods thickened with food approved gums lose viscosity when heated to and held at elevated temperatures. Food products which are designed with gums to yield adequate viscosity at high temperatures suffer from several drawbacks. First, food products which exhibit adequate high-temperature viscosity generally exhibit undesirably high low-temperature viscosities. Secondly, such food products generally exhibit undesirable sensory characteristics such as gumminess, thickness, and ropiness.
Attempts have been made to try to obtain a starch based thickening composition which would impart the desirable viscosity properties to food products at elevated serving temperatures. U.S Pat. No. 4,597,974 discloses a mixture of rice starch and carob-bean flour as the components of a food product thickener, the reference does not disclose the use of any cellulose derivatives.
U.S. Pat. Nos. 3,969,340 and 3,970,767 disclose certain blends of starch and amylose starches which have been hydroxypropylated and inhibited to a specific degree in order to impart specific viscosity properties to the starches. The blends are disclosed as being able to impart thickening properties to food products prepared under retort conditions.
In order to overcome the deficiency of starch thickened systems, manufacturers have found it necessary to add high levels of starch to the food products. This causes the problem of excessive viscosity at the low temperatures at which many of the food products are processed and packaged. Food manufacturers and the consumer would both benefit from food products that exhibit less of a viscosity loss or even a viscosity increase on heating. Manufacturers could gain processing efficiencies and consumers could have access to foods which show a stable viscosity response to serving temperatures.
SUMMARY OF THE INVENTION
The present invention relates to a method of thickening a food product. Typically, food products are thickened by the addition of starch. The improvement of this invention comprises the incorporation of methylcellulose into the starch and food product. The starch and methylcellulose are blended in a ratio and used in an amount effective to maintain the viscosity of the thickened food product at an elevated temperature at a value substantially equal to or greater than the viscosity of the thickened food product prior to the food product being heated to the elevated temperature.
More specifically in a method of thickening food compositions, wherein the food product is thickened by the addition of starch to the food product, the improvement comprises:
(a) incorporating methylcellulose into the starch and food product, wherein the ratio of the starch to methylcellulose is such that when the starch and methylcellulose are used in amounts up to about 5 percent by weight of a total food product, the viscosity at an elevated temperature is substantially equal to or greater than the viscosity of the thickened food product prior to its being heated to the elevated temperature:
(b) heating said mixture at a temperature and for a time period to effectively gelatinize said starch to form a homogeneous mixture; and
(c) cooling said mixture.
The thickened composition of the present invention exhibits the unexpected characteristic of maintaining or increasing the viscosity of a solution when heat is applied to the solution, unlike starch alone which tends to show a loss of thickening properties when subjected to extended periods of elevated temperatures. By a careful choice of the methylcellulose used in the composition, thickened systems may be designed which maintain or increase the viscosity of food products at elevated temperatures. Food processors could take advantage of this to design food products that exhibit fairly stable or increasing viscosity value during heating which would be more appealing and more palatable to consumers. Consumers would also benefit from foods that were easier to prepare and more palatable over a wider range of temperatures.
The present invention provides such a means to provide food products which have been designed to yield stable or increasing viscosities during heating. This will allow manufacturers to design food products which exhibit desirable rheological characteristics at specific temperatures without compromising the rheology at lower or higher temperatures.
DETAILED DESCRIPTION OF THE INVENTION
Those food products which may be thickened by the present invention include any edible food product which is desirable to consumers to maintain thickening properties upon heating of the food product. Examples of such food products include soups, sauces, cheese spreads, batters, dressings and the like. The food products which are useful in the present invention must be compatible with starch based and cellulose ether based thickening compositions. Typically food products could also include flavorings, spices and the like.
By the term "food product" as used herein is meant an edible food composition which has not been contacted with the thickening composition of the present invention. By the term "thickened food product" is meant any food product which has been contacted with the thickening composition of the present invention.
The starches used in the present invention are those varieties which are known as food approved starches. Such food approved starches include unmodified and modified glucose polymers of vegetable origin. Examples of suitable food starches include corn, wheat, sorghum, rice, casaba, potato, arrowroot, sago palm and mixtures thereof. Preferably, a corn starch is used in the present invention. Of the preferred corn starches, the most preferred include those crosslinked or substituted by any method accepted by the U.S. Food and Drug Administration in its regulations published in 21 CFR §172.892 which is incorporated herein by reference. Such food starches typically impart a thickening characteristic to the food products to which they are added.
The starch used in the present invention can be any of the above-mentioned food starches in either its native or modified form. Native starches are produced by extraction from: the seeds of such plants as corn, wheat, sorghum or rice; the tuber, or roots, of plants like casaba, potato or arrowroot: and the pith of the sago palm. The starch can be either pre-gelatinized or non-gelatinized. If the starch is non-gelatinized, the preparation process of the invention must have a heating step which must be sufficient to effect gelatinization during the preparation of the thickening composition.
Exemplary food starches include those available as Thin-n-Thik™ 99, Sta-Mist™ 365, Kol Guard™, and Mira-Thik™, available from A. E. Staley Company, Decatur, Illinois.
The amount of starch which is used in formulating the present thickening composition is that amount which is effective to impart the desired thickening properties to the food product to be thickened. The starch is desirably used in an amount which results in a thickened food product which exhibits a viscosity of at least about 100 percent of the viscosity of the thickened food product prior to being heated to the elevated temperature. More preferably, the starch is used in an amount which results in a thickened food product which exhibits a viscosity of at least about 125 percent, most preferably 150 percent, of the viscosity of the thickened food product prior to being heated to the elevated temperature. This amount may range from about 3 percent to about 7 percent of the total weight of the food product to be thickened. Preferably, the amount of starch used ranges from about 4 percent to about 6 percent of the total weight of the food product to be thickened.
Methylcellulose ethers are a class of cellulose ethers which have long been used in many industries as viscosity control agents, emulsifiers, and binding agents. The cellulose ethers are unique in that, at concentrations of 2 percent or more in water, they undergo thermal gelation. In essence, as the temperature of the solution of cellulose ethers increases, the polymer chains dehydrate to some extent and crosslink, forming a gel network. The gel formation is reversible upon the cooling of the solution of cellulose ether. At lower levels of concentration it is observed that the cellulose ethers respond like other hydrophilic materials in that the viscosity of the solution decreases with increasing temperature. In the practice of the present invention a particular cellulose ether is found to exhibit unexpected thickening properties when combined with starch to form a thickening composition. The particular methylcellulose ethers of the present invention help a solution to unexpectedly maintain or increase the viscosity of the solution upon heating when compared to the performance of other thickening compositions, particularly those using other types of cellulose ethers.
The methylcellulose used in the present invention may be prepared by any of a number of known methods. Generally, methylcellulose is prepared by the formation of an alkali cellulose by the addition of sodium hydroxide to a slurry of cellulose floc in a diluent. The alkali cellulose is then reacted with an alkyl halide, such as methyl chloride, under pressure. Thereafter, the slurry is neutralized and the product is extracted, dried and ground.
The methylcellulose ethers which are useful in the present invention are those which when combined in particular amounts and ratios with various starches impart a thickening property to food products which is maintained even at elevated temperatures. The amounts, ratios, and degree of thickening properties imparted to the food products by the thickening composition of the present invention are delineated in subsequent paragraphs.
The particular methylcellulose ethers which are useful in the present invention include those which, when in a 2 percent aqueous solution, exhibit a viscosity at 20° C. ranging from about 3 cps to about 3,500 cps. Preferably, the 2 percent aqueous solution at 20° C. exhibits a viscosity ranging from about 10 cps to about 1,000 cps and most preferably from about 15 cps to about 500 cps. Such viscosities are measured by conventional methods using Ubbelohde capillary tubes.
The molecular weights of such methylcellulose ethers range from about 10,000 to about 1,000,000, more preferably from about 50,000 to about 500,000 and most preferably from about 80,000 to about 400,000.
Examples of methylcellulose ethers include those commercially available as METHOCEL™, available from The Dow Chemical Company, Metolose™ and Pharmacoat™, available from the Shinetsu Chemical Company, Tokyo, Japan.
The amount of methylcellulose ether used in the present thickening composition is such that the viscosity of the thickened food product will be substantially maintained or increased when the food product is heated from a temperature ranging from about 15° C. to about 25° C. to an elevated temperature ranging from about 65° C. to about 100° C. By "substantially maintained" is meant that the viscosity of the food product containing the present thickening composition, after heating to an elevated temperature, will be at least 100 percent of the viscosity of the thickened food product prior to heating to the elevated temperature. Preferably, the thickened food product at the elevated temperature exhibits a viscosity which is at least 125 percent of the viscosity of the thickened food and most preferably 150 percent of the viscosity of the thickened food product prior to heating to the elevated temperature.
Preferably, the methylcellulose ether is used in amounts ranging from about 0.25 percent to about 1.5 percent based on the total weight of the food product. Most preferably, the methylcellulose ether is used in amounts ranging from about 0.5 percent to about 1.0 percent based on the total weight of the food product to be thickened.
The starch and methylcellulose comprising the thickening composition are used in total amounts ranging up to about 5 percent of the total weight of the food product to be thickened. The ratio of starch to methylcellulose ether is such that, when used in amounts up to about 5 percent by weight of the food product, the viscosity of the thickened food product at the elevated temperature is at least 200 percent of the viscosity of the food product prior to being thickened and heated to the elevated temperature. Preferably, the ratio is such that the viscosity of the thickened food product at the elevated temperature is at least 400 percent of the viscosity of the food product prior to thickening and heating. Most preferably, the ratio is such that the viscosity of the thickened food product at the elevated temperature is at least 600 percent of the viscosity of the food product prior to thickening and heating. Ratios of starch to methylcellulose ethers which will give the desired viscosity characteristics range from about 2:1 to about 28:1, preferably about 4:1 to about 12:1. Typically, the ratio is employed in as much as about 5 weight percent of the food product.
The thickened food products at the elevated temperature exhibit a viscosity ranging from about 2,000 cps to about 25,000 cps. More preferably, the viscosity of the thickened food product at the elevated temperature ranges from about 3,000 cps to about 18,000 cps and most preferably, from about 4,000 cps to about 13,000 cps.
The particular thickening compositions of the present invention may be formulated by incorporating methylcellulose into the starch and a food product, preferably in water to form a mixture. The mixture is heated to a temperature and for a time period to effectively gelatize said granules. Note, if pregelatinized starch granules are used, then the heating step is not necessary. There are several ways in which the methylcellulose can be incorporated into the food product and starch. The starch and food product can be mixed in water and then the methylcellulose is added. Another option is to admix the methylcellulose and food product together and then add the mixture to the starch and water. Alternatively, the starch and methylcellulose are admixed and then the food product is added, or all three components can be admixed together at the same time.
The mixture is heated to a temperature of at least 40° C., preferably, from about 40° C. to about 95° C. Generally, the mixture is heated until the starch gelatinizes. Preferably, the starch is heated for about 10 to about 30 minutes. The mixture is cooled to an edible temperature. The resulting mixture has a high viscosity which is maintained upon subsequent heating.
It is desirable that the composition be as homogeneously mixed as possible to insure a uniform dispersion of the starch and methylcellulose in the food product to be thickened. This may be accomplished by the thorough mixing of the composition after the addition of the thickening components.
The following comparative examples are included for purposes of comparison and are not intended as an illustration of the present invention.
COMPARATIVE EXAMPLE I
For the purpose of comparison only, a sample of a thickening composition based on starch only was prepared by the following procedure and tested for its ability to impart high temperature viscosity properties to a solution.
5 Grams of a 3:1 ratio of Thin-n-Thik™ 99 and Sta-Mist™ 365 modified starch is dispersed in 95 g of water at 20° C. in a 1-liter beaker. The starch is dispersed by stirring. The dispersion is then heated to 95° C. for a period of time sufficient to insure the gelatinization of the starch granules, about ten minutes. The solution is then allowed to cool to room temperature (20° C.). The solution is then placed in a sealed jar and allowed to stand overnight at room temperature in order to allow the solution to come to a viscosity equilibrium. The viscosity of the solution is then measured by rotational viscometry using a Brookfield RVT Rotational Viscometer set at 2.5 rpm and using a No. 3 spindle. The data is reported under Example C-1 in Table I. The jar of solution is then immersed in a water bath set at 40° C. and allowed to equilibrate at the water bath temperature for a period of 3 hours. The viscosity of the solution is then measured in the same manner as discussed above with regard to the solution at room temperature. The data is reported under Example C-1 in Table I. The viscosity of the solution is measured in a similar manner for solutions which have been immersed in water baths set at 60°, 80° and 95° C. The results are reported under Example C-1 in Table 1.
In a similar manner, the procedure of Comparative Example 1 is repeated except that, instead of 5 g of modified starch, 3.9 g of Kol Guard™ starch is used. The viscosity of the solution in measured in the same manner and the results are reported in Table I under Example C-1A.
The data illustrate that thickening systems based on starch alone are not able to maintain the viscosity of the thickened system at elevated temperatures.
COMPARATIVE EXAMPLE 2
For the purpose of comparison only, a sample of a thickening composition based on methylcellulose which, when in a 2 percent aqueous solution, exhibits a viscosity of 4,000 cps at 20° C. was prepared by the following procedure and tested for its ability to impart high temperature viscosity properties to a solution.
2.25 Grams of the above described methylcellulose is dispersed in 97.75 g of water at 95° C. in a 1-liter beaker. The methylcellulose is dispersed by stirring. The solution is then allowed to cool to room temperature (20° C.). The solution is then placed in a sealed jar and allowed to stand overnight at room temperature in order to allow the solution to come to a viscosity equilibrium. The viscosity of the solution is then measured by rotational viscometry using a Brookfield RVT Rotational Viscometer set at 5 rpm and using a No. 4 spindle. The data is reported under Example C-2 in Table I. The jar of solution is then immersed in a water bath set at 40° C. and allowed to equilibrate at the water bath temperature for a period of 3 hours. The viscosity of the solution is then measured in the same manner as discussed above with regard to the solution at room temperature. The data is reported under Example C-2 in Table I. The viscosity of the solution is measured in a similar manner for solutions which have been immersed in water baths set at 60°, 80° and 95° C. The results are reported under Example C-2 in Table I.
In a similar manner, the procedure of Comparative Example 2 is repeated except that 2.25 g of a hydroxypropyl methylcellulose which, when in a 2 percent aqueous solution exhibits a viscosity of 4,000 cps at 20° C. The viscosity of the solution is measured in a similar manner and the results are 20 reported in Table I under Example C-2A.
The data illustrate that, when methylcellulose or hydroxypropyl methylcellulose are used alone as thickening compositions, neither is able to maintain a desirable viscosity at the elevated temperatures.
COMPARATIVE EXAMPLE 3
For the purposes of comparison only, a sample of a thickening composition based on starch and other cellulose ethers other than methylcellulose were prepared by the following procedure and tested for their ability to impart high-temperature viscosity properties to a solution.
4 25 Grams of a 3:1 ratio of Thin-n-Thik™ 99 and Sta-Mist™ 365 modified starch is dispersed in 94.75 g of water at 20° C. in a 1-liter beaker. The starch is dispersed by stirring. The dispersion is then heated to 95° C. for a period of time sufficient to insure the gelatinization of the starch granules, about 10 minutes. To the hot solution is then added 1 g of a hydroxypropyl methylcellulose ether which, when in a 2 percent aqueous solution, exhibits a viscosity of 4,000 cps at 20° C., with stirring. The stirred solution is then allowed to cool to room temperature (20° C.). The solution is then placed in a sealed jar and allowed to stand overnight at room temperature in order to allow the solution to come to a viscosity equilibrium. The viscosity of the solution is then measured by rotational viscometry using a Brookfield RVT Rotational Viscometer set at 2.5 rpm and using a No. 3 spindle. The data is reported under Example C-3 in Table I. The jar of solution is then immersed in a water bath set at 40 ° C. and allowed to equilibrate at the water bath temperature for a period of 3 hours. The viscosity of the solution is then measured in the same manner as discussed above with regard to the solution at room temperature. The data is reported under Example C-3 in Table I. The viscosity of the solution is measured in a similar manner for solutions which have been immersed in water baths set at 60°, 80° and 95° C. The results are reported under Example C-3 in Table I.
A similar run is done using a hydroxypropyl methylcellulose ether as the second component in the thickening composition. This particular cellulose ether, when in a 2 percent aqueous solution, exhibits a viscosity of about 100,000 cps at a temperature of 20° C. The comparative run is measured for viscosity by the same method as discussed above. The results are reported under Example C-4 in Table I.
A similar run is done using a methylcellulose ether as the second component in the thickening composition. This particular cellulose ether, when in a 2 percent aqueous solution, exhibits a viscosity of about 4,000 cps at a temperature of 20° C. The comparative run is measured for viscosity by the same method as discussed above. The results are reported under Example C-5 in Table I.
A similar run is done using a methylcellulose ether as the second component in the thickening composition. This particular cellulose ether, when in a 2 percent aqueous solution, exhibits a viscosity of about 1,500 cps at a temperature of 20° C. The comparative run is measured for viscosity by the same method as discussed above. The results are reported under Example C-6 in Table I.
The data illustrate that certain cellulose ethers when combined with starch to form a thickening composition do not exhibit the desirable high temperature viscosity control that the present invention does.
The following examples are intended to illustrate the present invention and are not intended to limit the scope in anyway.
EXAMPLE 1
4.25 Grams of a 3:1 ratio of Thin-n-Thik™ 99 and Sta-Mist™ 365 modified starch is dispersed in 94.75 g of water at 20° C. in a 1 liter beaker. The starch is dispersed by stirring. The dispersion is then heated to 95° C. for a period of time sufficient to insure the gelatinization of the starch granules, about 10 minutes. To the hot starch solution is added with stirring 1.0 g of methylcellulose which, when in a 2 percent aqueous solution, exhibits a viscosity of 15 cps at 20° C. The solution is stirred for 10 minutes. Stirring is continued and the solution is allowed to cool to room temperature (20° C.). The solution is then placed in a sealed jar and allowed to stand overnight at room temperature in order to allow the solution to come to a viscosity equilibrium. The solution is then measured for viscosity by rotational viscometry using a Brookfield RVT Rotational Viscometer set at 2.5 rpm and using a No. 3 spindle. The data is reported under Example 1 in Table I. The jar of solution is then immersed in a water bath set at 40° C. and allowed to equilibrate at the water bath temperature for a period of 3 hours. The viscosity of the solution is then measured in the same manner as discussed above with regard to the solution at room temperature. The data is reported under Example 1 in Table I. The viscosity of the solution is measured in a similar manner for solutions which have been immersed in water baths set at 60°, 80° and 95° C.
The results are reported in Table I under Example 1.
The procedure is repeated except that 2.9 g of Kol Guard™ starch is used instead of the 4.25 g of modified starch. The viscosities of the solution are measured in the same manner and the results are reported in Table I under Example 1A.
EXAMPLE 2
4.25 grams of a 3:1 ratio of Thin-n-Thik™ 99 and Sta-Mist™ 365 modified starch is dispersed in 94.75 g of water at 20° C. in a 1-liter beaker. The starch is dispersed by stirring. The dispersion is then heated to 95° C. for a period of time sufficient to insure the gelatinization of the starch granules, about 10 minutes. To the hot starch solution is added with stirring 1.0 g of methylcellulose which, when in a 2 percent aqueous solution, exhibits a viscosity of 400 cps at 20° C. The solution is stirred for 10 minutes. Stirring is continued and the solution is allowed to cool to room temperature (20° C.). The solution is then placed in a sealed jar and allowed to stand overnight at room temperature in order to allow the solution to come to a viscosity equilibrium. The solution is then measured for viscosity by rotational viscometry using a Brookfield RVT Rotational Viscometer set at 2.5 rpm and using a No. 3 spindle. The data is reported under Example 2 in Table I. The jar of solution is then immersed in a water bath set at 40° C. and allowed to equilibrate at the water bath temperature for a period of 3 hours. The viscosity of the solution is then measured in the same manner as discussed above with regard to the solution at room temperature. The data is reported under Example 2 in Table I. The viscosity of the solution is measured in a similar manner for solutions which have been immersed in water baths set at 60°, 80° and 95° C.
The results are reported in Table I under Example 2.
The procedure is repeated except that 2.9 g of Kol Guard™ starch is used instead of the 4.25 g of modified starch. The viscosity of the solution is measured in the same manner and the results are reported in Table I under Example 2A.
TABLE I__________________________________________________________________________Viscosity (cps) of Solution as a Function of Temperature (°C.)TemperatureExample 20 40 60 80 95__________________________________________________________________________C-1* 6,400 5,360 3,187 1,947 1,733C-1A* 9,360 10,040 7,960 7,520 7,160C-2* 5,520 gel gel gel gelC-2A* 4,760 1,120 1,000 800 gelC-3* 15,120 9,460 5,700 3,500 3,420C-4* 163,300 72,900 18,480 7,280 7,020C-5* 17,213 20,360 8,653 4,920 15,200C-6* 16,120 17,900 16,200 8,340 6,2201 2,120 4,270 15,100 13,680 12,9601A 360 360 12,700 17,690 19,6002 7,573 8,387 11,053 7,293 17,0802A 2,740 3,280 14,840 13,540 13,200__________________________________________________________________________ *Not an example of the present invention.
The data in Table I indicate that the present invention imparts viscosity control over a wide range of temperatures and does not lose its thickening capability at elevated temperatures.
|
A method of thickening a food product which substantially maintains the viscosity of food products when they are heated to elevated temperatures. The method comprises using specific methylcelluloses in combination with various food approved starches.
| 0
|
[0001] This application claims the benefit, pursuant of 35 U.S.C. §119, of the earlier filing date of commonly owned patent application Ser. No. 92106107, filed on Mar. 19, 2003 in the Patent Office of the ROC, Taiwan.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates to Manufacturing Executing Systems (MES) and, more particularly, to a protocol used to communicate between servers and clients operating in a MES environment.
[0004] 2. Glossary of Terms
[0005] The following terms and definitions are offered in order to facilitate understanding of the invention:
CIM Computer Integrated Manufacturing CORBA Common Object Request Broker Architecture is the OMG platform-independent technique for programs running on different machines to communicate with each other. IDL Interface Definition Language. Generally refers to the OMG/CORBA IDL. Used to define interfaces to objects. Defines the types of objects according to the operations that may be performed on them and the parameters to those operations. This is similar to a C++ header file. For example, in the CORBA context, an IDL compiler generates “stubs” that can be called by client code and skeletons for implementing server code. IDL compilers exist to map the IDL definitions into various languages: C, C++, Smalltalk, Java. MES Manufacturing Execution Systems OMG Object Management Group SEMATECH SEmiconductor MAnufacturing TECHnology: an international research consortium in which member companies cooperate precompetitively in key areas of semiconductor technology, sharing expenses and risk with the common aim of accelerating development of advanced manufacturing technologies. SiView Standard An integrated Manufacturing Execution System (MES) and equipment automation offering from IBM that is compatible with the SEMY/SEMATECH CIM Framework and Object Management Group (OMG) standards. It uses object-oriented technology with plug-and-play flexibility to permit fine tuning of operational performance as needed. XML eXtensible Markup Language: a W3C proposed recommendation. Like HTML, XML is a simplified profile of SGML, for creating markup languages. XML: may be used to define many different document types, each of which uses its own element HTML type names. Hyper Text Markup Language uses a single SGML document type, with a fixed set of element type names, i.e., “tag names,” such as “html”, “body”, “h1”, “o1”. SGML An International Standard (ISO 8879)
[0006] 3. Background of the Art
[0007] In large manufacturing facilities, such as a semiconductor foundry in which many tools are required to build the wafer and chip product, there exist many complex software programs or packages that are used to run and monitor the performance of the tools. Many of these monitoring and control software packages are written to standards defined by the semiconductor equipment consortium SEMATEC. SEMATEC standards are typically used as they guide manufacturers in the way these programs should be implemented. The main framework for this system of software programs is known as the Computer Implemented Manufacturing (CIM) framework.
[0008] The overall control of the tools in the foundry is by a central computer or server having a Manufacturing Execution System (MES) tool control system. The central server has the information regarding each customer job that is currently being processed and ensures that each tool is performing the correct operation and in the appropriate sequence. This server communicates with users that monitor and control the production flow and operations on individual client workstations. A MES of the type suitable for this purpose is sold under the model name SiView and is published by International Business Machine Corp. (IBM) of Armonk, N.Y. SiView and IBM are registered trademarks of the IBM Corporation.
[0009] Currently, one of the goals of SEMATECH is to adopt a distributed communications pathway and protocol that is referred to as Common Object Request Broker Architecture (CORBA). This system allows for the development of distributed systems to operate seamlessly in an integrated architecture while functioning on various independent platforms. MES architectures, such as SiView, are following the recommendations of SEMATECH and are transitioning over to CORBA. With reference to FIG. 1, an example of a communication pathway 100 using CORBA 120 connects server 110 and client device 130 . Communication files are initiated through the CORBA communication pathway 120 using objects stored for use in a CORBA communication pathway using IDL files 115 , 125 .
[0010] While suitable for its intended purpose one drawback to the use of IDL is that complex monitoring and control tasks can result in the use of many objects or software modules resulting in a large collection of IDL files to accomplish a specific task. This build-up of IDL files 115 , 115 a, 115 b, etc., over time, adds complexity and additional overhead to the communication pathway. For example, a server may initially provide for the monitoring of two functions, such as “lot track in” and “lot track out,” wherein “lot track in” may be representative of a monitoring function that monitors the input of a product lot and “lot track out” may be representative of a monitoring function that monitors the output of the production lot. In this case the IDL file contains two methods. Over time, as the desire to monitor more features grows and the capability to monitor more features increases, more functions may be added to enhance the server's capability. For example, functions such as “lot information inquiry,” “operation history inquiry,” “tool information inquiry,” “lot running hold” may be functions that are desired and added.
[0011] One method of organizing these new functions may be to develop categories of operations that include one IDL file per category. For example categories may be represented as:
[0012] Category 1-Action applied on lot;
[0013] Category 2-Information inquiry on lot;
[0014] Category 3-Action applied on tool;
[0015] Category 4-flow/routing setting; and
[0016] Category 5-modeling recipe manipulation
[0017] Thus, an IDL file associated with Category 1 may monitor or track the input and output of material, for example. Category 2 may include an IDL file for a “query of lot information” or a “lot operation history.” Category 3 may include an IDL file for setting or resetting the operation mode of a tool or for requesting a “tool operational status.” Category 4 may include an IDL file for flow management or route settings and Category 5 may include an IDL file for modeling individual recipes.
[0018] However, an IDL file may become diverse and complex as new functions are added to the file. For example, an IDL file, entitled “File A” associated with category 1: (version 1.0), may monitor input and output using the following instructions shown here in the well known IDL programming language as:
File A: “basic_result_structure” Interface ActionOnLot { TrackInResult = Trackin(); TrackOutResult = TrackOut()
[0019] However, a user may need or desire additional actions such as “hold/release.”In this case, IDL file, File A, may be modified as:
File A: “basic_result_structure” Interface ActionOnLot { TrackInResult = TrackIn(); TrackOutResult = TrackOut(); HoldResult=hold(); ReleaseResult=release();
[0020] Users may desire to enhance the hold function with functions such as “future hold,” “hold right now,” and “hold after current operation complete.” In this case, the IDL file, entitled “File A1,” may be represented as:
File A1 include “file A” include “Enhanced_Result_Structure” interface enhancedActionOnLot : basicActionOnLot { future_hold_result = future_hold(); enhanced_hold_result_1 = hold(in string Flag_HoldRightNow?); hold_next_result = hold_next(); enhanced_release_result = release(in string user_id); //check user id.
[0021] In this case “File A,” which has many of the desired features, is included in the new process, “File A1.” Thus, as new functions are added to the monitoring process, an increase in the complexity and number of the IDL statements naturally occurs. However, changes to basic IDL functions, such as File A, may cause operations of more complex functions to operate in an unexpected and undesired manner.
[0022] Accordingly, there is a need for a method and system that allows for improved monitoring and tracking capability without significant increase in the complexity of the programming instructions performing the monitoring operations.
SUMMARY
[0023] A system and method is disclosed for defining the interface of a manufacturing execution (MES). XML (Extensible Markup Language) is used to form an interface definition file and a XML tag-set file for simplifying the IDL (Interface Definition Language) files used by SiView MES that allows for the removal of Interface Repositories (IFR) so that each the server and clients need only maintain an XML tag-set file and Interface Definition File. Furthermore, an XML schema file is used for validating the contents of the XML output file. The system for defining the MES interface to process a transaction between a server, having an MES, and a client through an XML file based on a communication protocol, comprises an IDL file for executing a plurality of service objects of the MES, an XML tag set file, wherein the XML tag set file uses XML for defining interfaces of the plurality of service objects and an XML schema file, wherein the XML schema file is within a web server for validating an output content generated by executing IDL file and the XML tag set file, wherein the XML tag set file is adapted to serve at least one argument of the plurality of service objects within the IDL file.
[0024] It will be appreciated by those skilled in the art that with this new mechanism introduced above, the following benefits may be achieved:
[0025] message content of a transactional based MES utilized with a protocol suitable to that format can be projected onto a standard, well-organized XML format;
[0026] using XML as a remedy to eliminate or reduce handling of diverse IDL content as there is one single ASCII text typed IDL file composed and described by XML;
[0027] an XML object is made more portable and not limited to a single communication pathway.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In the drawings:
[0029] [0029]FIG. 1 is a system diagram of a conventional communication pathway;
[0030] [0030]FIG. 2 a is a system diagram of a communication pathway according to the present invention;
[0031] [0031]FIG. 2 b is an alternate system diagram of a communication pathway according to the present invention;
[0032] [0032]FIG. 3 is an example of an IDL envelope expressed in “C” programming language source code;
[0033] [0033]FIG. 4 is an exemplary structure for an XML schema in accordance with the principles of the invention;
[0034] [0034]FIG. 5 a is an example of a transaction structure within an XML schema disclosed in FIG. 4;
[0035] [0035]FIG. 5 b is an example of a header structure within an XML schema disclosed in FIG. 4;
[0036] [0036]FIG. 5 c is an example of a content structure within an XML schema disclosed in FIG. 4.
[0037] [0037]FIG. 6 illustrates an exemplary XML schema for requesting information from a server in accordance with the principles of the invention; and
[0038] [0038]FIG. 7 illustrates an exemplary XML schema for replying to the request for information shown in FIG. 6.
[0039] It is to be understood that these drawings are solely for purposes of illustrating the concepts of the invention and are not intended as a definition of the limits of the invention. The embodiments shown in the figures and described in the accompanying detailed description are to be used as illustrative embodiments, and should not be construed as the only manner of practicing the invention. It is to be understood that these drawings are for purposes of illustrating the concepts of the invention and are not to scale. Also, the same reference numerals, possibly supplemented with reference characters where appropriate, have been used to identify similar elements.
DETAILED DESCRIPTION
[0040] [0040]FIG. 2 a illustrates an overview 200 of the use of XML in accordance with the principles of the present invention. In this overview, server 205 includes capability to use XML and IDL 115 . In this case XML information is passed through Web for XML schema validation 210 to client 220 . Client 220 also includes capability to use XML to unwrap the transferred information.
[0041] [0041]FIG. 2 b illustrates an alternative MES communication system 250 in accordance with the principles of the present invention. In this case, MES configuration 250 is shown including a server 205 and client 220 connected by a communication pathway 120 as previously discussed. Server 205 and client 220 are adapted to generate objects using an XML protocol layer 207 and 227 while the communication pathway 120 transmits objects using an IDL protocol layer. Protocol gateways 25 , 270 are provided between the communication pathway 120 and the client 205 and server 220 wherein XML object 260 , defined by the XML protocol, 207 for example, are stored in an IDL envelope 265 for transmission across the CORBA communication pathway 120 . It will be appreciated by those skilled in the art that XML, a world wide standard, is supported by many IT vendors, such as IBM, MICROSOFT and SUN MICROSYSTEMS, and allows for objects 260 to be defined a pure text, self-described form. By using XML protocol layer 255 , 270 , XML objects 260 can be shared using many other communication pathways such as TCP/IP 50 , TIBCO RV 52 and SOAP 54 without the need for conversion. TCP/IP is well known in the networking art and is composed of layers, wherein “IP” is responsible for moving a packet of data from network node to network node by forwarding each packet based on a four byte destination address (e.g., the IP number) and “TCP” is responsible for verifying the correct delivery of data from client to server.
[0042] In accordance with the principles of the invention, the IDL file may be made invariant by describing one service that is to be provided by server 205 . For example, FIG. 3 illustrates XML object, entitled SiView_Transaction, expressed in “C” programming language, which includes a single text input and a single text output. In this exemplary example, the input is an ASCII typed argument and the output is a string of ASCII characters. The input and output are described in XML format.
[0043] As one skilled in the art would recognize, a well-defined XML file is useful as the XML file infers the existence of a schema file that can perform content validation. By using this feature, several IDL files used in an MES, such as SiView, may be folded into a single well-defined XML file. For example, in a system, such as SiView, there may be transactional based MES with almost all text content. In this case, the objects may be more easily transformed or converted IDL to XML formats and gateways 255 , 270 , which may be performed by software routines on server 210 and the clients 220 , respectively, operating as separate units, can encapsulate the XML defined object into an IDL envelope.
[0044] [0044]FIG. 4 illustrates a schema structure 400 having a transaction region 410 that includes a header region 430 and a content region 450 . The transaction region 410 includes information common to the transaction performed. For example, transaction region 410 may include information associated with identification 412 , an action 414 to be performed or a function identification 416 . The transaction region 410 further includes information with regard to header region 430 and content region 450 .
[0045] Header region 430 includes information regarding a source, e.g., system 432 and node 434 , and information regarding any message, i.e., rc 436 or message identification 438 , that is required. Header 430 may further include information regarding a user, e.g. pwd 440 .
[0046] Content region 450 includes information regarding a particular production lot 452 . For example, lot 452 may include information regarding whether there is a hold status 454 request or a lot identification 456 . Similarly, other information, referred to as any 2 , 452 , and any 3 , 454 may be defined.
[0047] [0047]FIG. 5 a illustrates an example of a transaction region 410 of a sample XML schema in accordance with the principles of the invention. In this exemplary transaction region 410 , three attributes are identified, “id name” 510 , “action” 512 and “function id” 514 , that enables a user to provide input. For example, attribute “id name”, is identified or typed as requiring a “string,” of conventional alphanumeric values that may be entered by a user or may be read from a file. Similarly, attributes “action” 512 and “function id” 514 are typed as requiring similar “string” inputs. The element “transaction” 516 is identified as including the attributes “id name,” “action” and “function id”, which are represented as 510 ′, 512 ′ and 514 ′, respectively.
[0048] Transaction region 410 further defines the elements “Header” 520 and “Content” 540 , which are more fully explained with regard to FIG. 5 b and 5 c, respectively. As one skilled in the art would appreciate, transaction region 410 may contain more than one transaction region, which is illustrated as 410 ′. Each transaction region may define different attribute types and header and content elements.
[0049] [0049]FIG. 5 b illustrates an example of a header element 430 of a sample XML schema in accordance with the principles of the invention. In this exemplary header element 430 , the element “msg” 436 is identified and typed as including two attributes, “rc” and “msg_id,” which are represented as 432 ′ and 434 ′, respectively. Attributes “rc” and “msg_id” are identified and typed, at 432 and 434 , respectively, as being “string” values. Similarly, the element “from” 438 is identified and typed as including two attributes, “node” and “sys”, represented as 440 ′ and 442 ′, respectively. In this illustrated example, header element 410 further includes a user element 444 containing a single attribute “pwd”, represented as 446 ′. Attribute “pwd” is identified and typed as a “string” data type, represented as 446 .
[0050] The header element 430 ′ is next identified and typed as containing three elements, “from” 438 , “msg” 436 and “user” 444 , and one attribute “sno” 448 ′. Attribute “sno”, i.e., serial number, is identified and typed as a “string” data type 448 .
[0051] [0051]FIG. 5 b illustrates a similar structure for content element 450 . In this case, content element 450 , illustrated as 450 ′, includes a single element 452 ′, referred to as “lot”. Element “lot” 452 is then identified and typed as including three elements, “any 3 ” 454 ′, any 2 , 456 ′ and “holdstate” 458 ′ and one attribute, “lot_id” 460 ′. In this case, attribute “lot_id” 460 is used to provide information to the user and is identified and typed as a “string” data type. Furthermore, elements “any 3 ” 454 , “any 2 ” 456 and “holdstate” 468 include a single attribute “txt”, shown as 460 ′. Attribute “txt” is identified as a “string” data type 460 .
[0052] [0052]FIG. 6 illustrates a schema 600 requesting a server to provide information regarding a specific “lot.” In this exemplary schema, transaction 610 includes three attributes, Transaction Id, Action and Func Id that are defined as “lotInfoInq”, “Inquery” and “0001”, respectively, at line 615 . A Header section 620 includes a single attribute “sno” equal to “00100” at line 622 , and two elements From Node and sys equal to “MyPC” and “OMI” at line 624 . At line 626 , a user password, identified as ABC and set to “123” is illustrated as an example.
[0053] A content section 630 is shown having a Lot_id set to ABC100.00.00 at line 632 . Additional textual information, presented as Any 2 and Any 3 may be included in the header section.
[0054] [0054]FIG. 7 illustrates an exemplary schema 700 for a server replying to the request schema shown in FIG. 6. In this exemplary schema, transaction region 710 includes three attributes: Transaction Id, Action and Func Id, which are set to “LotInfoInqReply”, “ResultReply” and “0005,” respectively. Header section 720 includes a single attribute “sno” that identifies the header at line 722 . It further includes two elements, From and Msg. A content section 730 includes one attribute Lot_id at line 732 for returning the results to the client. Content section 730 may include additional information, shown as any 2 and any 3 , at lines 734 and 736 respectively.
[0055] While the invention has been described with reference to the preferred embodiments thereof, it will be appreciated by those of ordinary skill in the art that modifications can be made to the parts that comprise the invention without departing from the spirit and scope thereof, as defined by the claims.
|
A system and method for defining MES interface to process a transaction between a server and a client from an XML base, the transaction between the server and the client based on a communication protocol, the server having an MES, the system for defining the MES interface comprising an IDL file for executing a plurality of service objects of the MES, an XML tag set file, wherein the XML tag set file uses XML for defining interfaces of the plurality of service objects and an XML schema file, wherein the XML schema file is within a web server for validating an output content generated by executing IDL file and the XML tag set file, wherein the XML tag set file is adapted to serve at least one argument of the plurality of service objects within the IDL file.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the present disclosure relate to the field of duct or chamber systems. More particularly, the present disclosure relates to a system and method for detecting unwanted foreign particles within a duct or air handling system.
2. Discussion of Related Art
In air handling or ventilation systems (HVAC), fans draw fresh outside air into a building, and exhaust stale interior air to the outside. These air handling systems use venting or ducts (i.e. ductwork) to provide an air flow path throughout the building, including to and from heaters and/or air conditioners. To assist in adjusting the volume of air flow, volume control dampers and fans may be used. These dampers and fans can be fitted within the ducts themselves and may be manually or automatically activated.
On occasion, unwanted foreign particles may enter the ductwork of such air handling systems. For example, in the case of a fire, smoke may enter the ductwork. To control the spread of smoke throughout the duct system and subsequently other rooms of the building, smoke dampers may be used which may be automated with the use of a mechanical motor, often referred to as an actuator. For example once smoke is detected by a sensor within the duct, the sensor sends a signal to the actuator to close the smoke damper. A signal may also be sent from the sensor to shut down the fans thereby limiting the spread of smoke through the ducts which would otherwise travel to other rooms or parts of the building. Thus, detectors/sensors may be located throughout the ductwork of a building to detect the presence of smoke which triggers the control of fans and dampers to prevent smoke from traveling or spreading to unwanted areas therein.
FIG. 1 is a functional depiction of a conventional duct sensor 100 used to detect smoke within a duct. The duct sensor 100 includes a sampling tube 110 , a smoke sensor 120 , and exhaust tube 130 . The sampling tube 110 is used to collect the smoke and then to guide the air through the smoke sensor 120 . After passing through the smoke sensor 120 , the air is then released through the exhaust tube 130 . If smoke is detected by the smoke sensor 120 , display 140 indicates the detection of smoke by the duct sensor 100 . Those of ordinary skill in the art will recognize that the depicted system is highly-simplified for ease of explanation.
FIG. 2 illustrates a cross-sectional view of conventional duct sensor 200 attached to duct 240 , the walls of which define duct chamber 240 a . Smoke sensor 220 is attached to housing 260 and is located outside of duct 240 . Housing 260 is connected to exhaust tube 230 and sampling tube 210 . To attach housing 260 to duct 240 , two holes 215 A and 215 B must be formed in a wall of the duct to allow sampling tube 210 and exhaust tube 230 to project into duct chamber 240 a respectively. As such, this requires two holes for every duct sensor that is attached to a portion of the ductwork. To prevent room particles from entering the duct system or duct particles from entering the room, gaskets or other means (not shown) must be used to seal the two holes. Thus, there exists a need for a new and improved duct sensor/detector to reduce the number of holes that need to be created in a duct system.
Sampling tube 210 also includes access holes 250 for capturing air that flows through duct 240 . To prevent sampling tube 210 from recapturing exhausted smoke from exhaust tube 230 , sampling tube 210 must be located upstream of exhaust tube 230 . This means that exhaust tube 230 must be positioned downstream of sampling tube 210 when attaching the duct sensor 200 to the duct system. Thus, conventional duct sensor 200 must be properly oriented to allow the duct to funnel air in through sampling tube 210 , across sensor 220 via housing 260 , and out through exhaust tube 230 . Hence, there exists a need for a new and improved duct sensor to eliminate possible orientation errors when installing a duct sensor/detector.
Furthermore, air must be flowing through the duct to allow conventional sensor 220 to sample the air in the duct. Therefore, before a conventional duct sensor 200 can be properly tested to make sure the smoke sensor 220 is operating properly, it must be verified that air is flowing within the duct. Thus, in an effort to properly test the smoke sensor 220 and to make sure air is flowing within the duct, a device may be required to be placed within the duct before testing. This device measures the airflow or differential pressure of the duct to indicate whether or not airflow is present around the sensor 220 . Without these additional devices, it may be impossible to know whether the smoke supplied for testing has reached the sensor 220 or if the smoke has traversed through the device that measures differential pressure which may compromise testing. Thus, there exists a need for a new and improved duct sensor/detector to eliminate the need for air flow testing.
SUMMARY OF THE INVENTION
Exemplary embodiments of the present disclosure are directed to a particle detection unit including a detection chamber; a duct detector disposed within the detection chamber, comprising a rod having a first and a second end, the first end distal the second end, a reflector attached to the rod adjacent the first end, and a sensor/emitter device attached to the rod and spaced apart from the reflector at the second end wherein particles disposed between the first and second ends are detected.
In another exemplary embodiment, a particle detection unit includes a detection chamber; a duct detector disposed at least partially within the detection chamber, and having a sensor attached to an inner wall of the detection chamber. An emitter is attached to the inner wall of the detection chamber opposite the sensor. In another exemplary embodiment, a particle detection unit includes a detection chamber and a duct detector, disposed within the chamber which is defined by a rod having a first and a second end. The first end is distal the second end. An emitter is attached to the rod adjacent the first end, and a sensor is attached to the rod and spaced apart from the reflector.
In an exemplary method, a duct detector is installed within a detection chamber defined by a wall having an inner surface. The duct detector is attached to the inner surface of the duct and smoke is detected within the chamber. The duct detector comprises a rod having a first and a second end. The first end is distal the second end and a reflector is attached to the rod adjacent the first end. A sensor and emitter device is attached to the rod and spaced apart from the reflector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional diagram of a conventional duct sensor.
FIG. 2 is a cross sectional view of a conventional duct sensor attached to a duct.
FIG. 3 is a cross sectional view of a duct detector in accordance with the present disclosure.
FIG. 4 is a side view depiction of a duct detector in accordance with the present disclosure.
FIG. 5 is a side view depiction of a duct detector including a telescoping rod in accordance with the present disclosure.
FIG. 6 is a side view depiction of a duct detector without a rod in accordance with the present disclosure.
FIG. 7 a is a side view depiction of a cover in accordance with the present disclosure.
FIG. 7 b is a front view depiction of a cover in accordance with the present disclosure.
FIG. 8 is a side view depiction of a duct detector within a tubular rod in accordance with the present disclosure.
DETAILED DESCRIPTION
The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention, however, may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings like numbers refer to like elements throughout.
FIG. 3 shows a cross-sectional view of an exemplary duct detector 300 consistent with one embodiment of the present disclosure. Those of ordinary skill in the art will recognize that the depicted system is highly-simplified for ease of explanation. In this exemplary embodiment, the duct detector 300 is inserted and attached to an air duct 310 . The shape of the duct is defined by the duct walls. Generally, an improved duct detector is inserted or attached to any chamber or other confined space such as, for exemplary purposes only, ductwork, plenums, air handlers, silos, etc.
Duct detector 300 includes a rod 320 which has a reflector 330 coupled to the distal end of the rod 320 . A sensor and emitter (sensor/emitter) device 340 is spaced apart from the reflector 320 and is also coupled to the rod 320 . The sensor and emitter device 340 may contain both a light sensor and emitter. As depicted, the rod 320 including the reflector 330 , and sensor and emitter device 340 , is inserted into the chamber of duct 310 . To insert duct detector 300 into the duct 310 , a single penetration hole (not shown to scale) may be made in the duct 310 the size of which is dependent on the size of the sensor and emitter device 340 , rod 320 , and reflector 330 . The rod may be hollow to accommodate wiring to and from the sensor and emitter device 340 and reflector 330 . The rod 320 may then be attached, for example, to the duct 310 by any means known in the art. Thus, with this embodiment only a single penetration hole may be created in the duct 310 housing to accommodate rod 320 , reflector 330 , and sensor and emitter device 340 . This embodiment advantageously reduces the number of holes needed in the duct housing as compared to using a conventional duct detector 200 where two holes must be created to allow for sampling tube 210 and exhaust tube 230 to penetrate into the duct as shown in FIG. 2 .
With this embodiment, the sensor/emitter device 340 and the reflector 330 are used to detect particles (i.e., smoke) within the duct. The reflector 330 along with the sensor/emitter device 340 use technology that is similar to a beam detector for detecting particles (i.e., smoke) in the air. In particular, light from the emitter portion of emitter/sensor 340 is transmitted within the duct 310 toward reflector 330 which reflects the light back toward sensor portion of emitter/sensor 340 . When particles are present within the air within duct 310 , the sensor portion of emitter/sensor 340 will not receive the same amount of light emitted by the emitter portion of emitter/sensor 340 . More specifically, it is the difference between the amount of light produced by the emitter and the amount of light received by the sensor via the reflector 330 , as well as the distance between the sensor 340 and reflector 330 which is used to calculate the percentage of obstructed light. This percentage of light obstruction is used to determine the presence of unwanted particles (i.e., smoke) between the emitter and the sensor. Generally, percent obscuration is reported per foot. Thus, if the distance between the emitter and sensor is, for example, 12 inches then the percent obscuration is the real value. However, if the distance between the emitter and sensor is 6 inches, then the percent obscuration is reported as two times the value since the light is only going half the distance. Thus, when the percentage of obstructed light exceeds a predetermined threshold an alarm is triggered. The duct detector 300 communicates with alarm indicating devices via control modules and/or control panels through wired or wireless connections 350 which may be, for example, bells, alarms, LED indicators, displays, etc.
By inserting the sensor and emitter device 340 into the duct 310 , the duct detector 300 uses the duct itself as a chamber for detecting particles (i.e., smoke). Thus, rather than placing the sensor and emitter device 340 outside of the duct and guiding the air across the sensor as in duct sensor 200 described above, the sensor and emitter device 340 are placed within the duct 310 , thereby eliminating the need to test whether or not air is flowing prior to testing the sensors. In this manner, the need to use airflow and differential pressure devices to detect airflow within the duct 310 prior to the testing is advantageously eliminated.
Likewise, because the duct 310 may now be used as the sensing chamber, the duct detector 300 eliminates the orientation problems described above with respect to conventional smoke detector 200 . More specifically, upstream and downstream orientation concerns regarding sampling tube 210 and exhaust tube 230 are eliminated. The airflow is no longer depended on to guide the smoke out of the duct to the sensor 220 . The sensor and emitter device 340 are now located within the duct itself. In addition, the spacing between the sensor/emitter and thus the distance the light travels from the sensor portion of emitter/sensor 340 to reflector 330 and back to the sensor portion of emitter/sensor 340 may be much closer as compared to convention beam detectors.
Groups of duct detectors may be installed within an air handling systems and wired together along a pair of bidirectional communication lines. A group of such devices on a pair of lines is often referred to as a “line of devices.” Many lines of devices can connect back to a control panel that controls the operation of an alarm system. A line of devices is usually associated with a certain zone of the building and/or a certain type of device. For example, one floor of a multi-story building may have duct detectors wired together on a line that connects back to the control panel. Also, each duct detector on a line may be individually addressed from the control panel. Addressing individual devices allows a single duct detector to indicate an alarm condition at a specific location on a line, provides selective operation of specific duct detectors, and can also be useful for fault diagnosis and/or individual duct detector testing.
To perform fault diagnosis and/or individual duct detector testing, a self test mode may be used to eliminate the need to perform a smoke test. Smoke tests are undesirable because actual smoke is introduced into the duct and forced by the sensor. Rather than triggering an alarm indicating device by obstructing the light between the sensor and emitter or sensor/emitter device and reflector with smoke, the emitter's light output may be decreased or obstructed by other means to trigger an alarm indicating device.
One exemplary way to implement a self test mode to test a sensor may be to decrease the light that is emitted by the emitter or reflected by the reflector. Reducing the amount of light received by the sensor simulates the light reduction caused by smoke. Reducing the light received by the sensor may be caused by decreasing the light output of the emitter's LED or by decreasing the reflection characteristics of the reflector. Once, the light output is decreased the sensor may measure the reduction in light and trigger an alarm indicating device as discussed above.
Another exemplary embodiment used to test a sensor may be to implement a lens or filter to decrease the light that is detected by the sensor. The lens or filter may be placed within the light path between the emitter/sensor. By placing the lens or filter within the light path, the light received by the sensor is reduced thereby simulating the obstruction of light caused by smoke. Additionally, the lens or filter may be electro-mechanically inserted into the light path by any means known in the art, such as a relatively small motor. Generally, self test mode devices such as, the lens, filter, and LED for the light reduction or output of the emitter, may all be controlled remotely from a control panel as described above.
FIG. 4 shows a cross-sectional view of a duct detector 400 consistent with one embodiment of the present invention. Those of ordinary skill in the art will recognize that the depicted system is highly-simplified for ease of explanation. The duct detector 400 is inserted and attached to an air duct 410 . The duct detector 400 includes a rod 420 and a sensor 430 which is attached to a distal end of the rod as illustrated in FIG. 4 . Opposite the sensor 430 , an emitter 440 may be attached to the rod 420 . Conversely, the position of the emitter 440 may be interchanged with the position of the sensor 430 .
To insert the duct detector 400 into the air duct 410 , a single penetration hole may be made in the wall of duct 410 . The size of the penetration hole may be dependent on the size of the sensor 430 , the emitter 440 , and the rod 420 . With this embodiment, it is the sensor 430 and emitter device 440 that are used to detect particles (i.e., smoke) within the duct. For example, the sensor 430 and emitter 440 may use technology that is similar to a beam detector for detecting particles (i.e., smoke) in air. However, the spacing between the sensor 430 and the emitter 440 may be used at much closer distances as compared to a beam detector. More specifically, it is the difference between the amount of light produced by the emitter 440 and the amount of light that is received by the sensor 430 , as well as the distance between the two that is used to calculate the percent obscuration of the light. This percent of obscuration may be used to determine the presence of particles (i.e., smoke) between the emitter 440 and the sensor 430 . Thus, as described above with reference to duct detector 300 , when the percentage of obscuration passes a predetermined threshold, an alarm is triggered by duct detector 400 . Again, to trigger an alarm or implement a self test mode, duct detector 400 may be in communication with alarm indicating devices or central control panels through wired or wireless connections 450 . Additionally, to trigger an alarm, duct detector 400 may be also be equipped with self test mode devices, as described above with reference to FIG. 3 . This eliminates the need for a smoke test when testing the sensor of duct detector 400 .
FIG. 5 shows a cross-sectional view of a duct detector 500 consistent with one embodiment of the present invention. Those of ordinary skill in the art will recognize that the depicted system is highly-simplified for ease of explanation. The duct detector 500 is inserted and attached to an air duct 510 . However, as depicted in FIG. 5 , rods 320 and 420 of FIGS. 3 and 4 , respectively, are substituted by a telescoping rod 520 . The use of a telescoping rod 520 may be used to more easily adjust how far rod 520 penetrates the chamber of the duct 510 . Here again, duct detector 500 may implement a sensor and emitter device 540 along with a reflector 530 as described with relation to FIG. 3 . Duct detector 500 may also implement a sensor and emitter configuration as described with relation to FIG. 4 . With either configuration a single penetration hole may be made in the duct 510 prior to inserting duct detector 500 into air duct 510 . The size of the penetration hole may be dependent on the size of the duct detector 500 . The telescoping rod 520 may then be substantially attached, for example, to the wall of the duct 510 by any means known in the art.
As described above with reference to duct detector 300 , when the percentage of obscuration passes a predetermined threshold, an alarm indicating such may be triggered by duct detector 500 . Again, to trigger an alarm or implement a self test mode, duct detector 500 may be in communication with alarm indicating devices or central control panels through wired or wireless connections 550 . Additionally, to trigger an alarm, duct detector 500 may also be equipped with self test mode devices, as described above with reference to FIG. 3 . This eliminates the need for a smoke test when testing the sensor of duct detector 500 .
FIG. 6 illustrates a cross-sectional view of a duct detector consistent with one embodiment of the present invention. Those of ordinary skill in the art will recognize that the depicted system is highly-simplified for ease of explanation. The duct detector 600 is substantially inserted and attached to opposing walls of air duct 610 . However, as depicted in FIG. 6 , rods 320 and 420 of FIGS. 3 and 4 , respectively, are removed. Here again, duct detector 600 may implement a sensor and emitter device 640 along with a reflector 630 as described with relation to FIG. 3 . However, sensor and emitter device 640 is attached to a wall of the duct 610 substantially opposite reflector 630 . Duct detector 600 may also attach a sensor to the wall of the duct 610 substantially opposite an emitter. Any means known in the art may be used to attach the sensor and emitter device 640 , reflector 630 , emitter, or sensor to the wall of the duct and may be dependent on the size of the sensor and emitter device 640 , reflector 630 , emitter, or sensor used for the duct detector 600 .
As described above with reference to duct detector 300 , when the percentage of obstruction passes a predetermined threshold an alarm indicating such may be triggered by duct detector 600 . Again, to trigger an alarm or implement a self test mode, duct detector 600 may be in communication with alarm indicating devices or central control panels through wired or wireless connections 650 . Additionally, to trigger an alarm, duct detector 600 may be also be equipped with self test mode devices, as described above with reference to FIG. 3 . This eliminating the need for a smoke test when testing the sensor of duct detector 600 .
FIGS. 7 a and 7 b illustrate one exemplary embodiment of a cover 700 . FIG. 7 a depicts a side view of the cover 700 and FIG. 7 b depicts a front view of cover 700 . The cover 700 may be coupled to a rod, telescoping rod, duct wall, sensor/emitter device, sensor, emitter, or reflector. The cover may be used to substantially prevent particles (i.e., dust) from accumulating on a sensor and emitter device, reflector, sensor, and emitter. Whatever shape used, the cover 700 substantially prevents dust accumulation while still allowing the emitter, sensor, and reflector to emit, sense, and reflect light 710 , respectively. By covering the above mentioned structures, particles such as dust may be substantially prevented from overwhelming the structures. This may in turn prolong the accuracy of the duct detector in detecting particles (i.e., smoke) within a duct. By substantially preventing particles from overwhelming the sensor, emitter, and reflector structures the duct detector may substantially maintain its accuracy for detecting smoke for longer periods of time.
FIG. 8 shows a side view of a duct detector 800 consistent with one embodiment of the present invention. Those of ordinary skill in the art will recognize that the depicted system is highly-simplified for ease of explanation. The duct detector 800 is substantially inserted and attached to an air duct 810 . However, as depicted in FIG. 8 , rods 320 and 420 of FIGS. 3 and 4 , respectively, are substituted by a substantially tubular rod 820 . The use of a tubular rod 820 may be used to protect the sensor and emitter device, sensor, emitter, or reflector while allowing smoke or other particles to travel through ventilation structures 830 . By implementing a sensor and emitter device within the tubular rod 820 , and on one side of the ventilation structures 830 , and a reflector within the tubular rod 820 , and on the other side of the ventilation structure 830 , the particles (i.e., smoke) may pass through the tubular rod 820 and in between the sensor and emitter device and reflector. Likewise, the duct detector 800 may also implement a sensor and emitter within the tubular rod 820 . The sensor located within the tubular rod 820 across from the emitter which may also be located substantially within the tubular rod 820 . Between the sensor and emitter, ventilation structures 830 may be used to allow particles (i.e., smoke) to pass through the tubular rod 820 and enter the line of site between the emitter and sensor. With either configuration a single penetration hole may be made in the duct 810 prior to inserting duct detector 800 into air duct 810 . The size of the penetration hole may be dependent on the size of the duct detector 800 . The tubular rod 820 may then be substantially attached, for example, to the wall of the duct 810 by any means known in the art.
As described above with reference to duct detector 300 , when the percentage of obstruction passes a predetermined threshold, an alarm indicating such may be triggered by duct detector 800 . Again, to trigger an alarm or implement a self test mode, duct detector 800 may be in communication with alarm indicating devices or central control panels through wired or wireless connections 850 . Additionally, to trigger an alarm, duct detector 800 may be also be equipped with self test mode devices, as described above with reference to FIG. 3 . This eliminates the need for a smoke test when testing the sensor of duct detector 800 .
The improved duct detector disclosed herein advantageously reduces the number of holes required to install a duct detector within a duct system. In fact, only one installation hole may be created within the duct per at least one duct detector that is to be installed within a duct.
The improved duct detector disclosed herein advantageously uses the duct itself as a chamber for detecting particles (i.e., smoke) which obviates the need to use airflow and differential pressure devices. Thus, there is no longer a need to confirm the presence of airflow before testing the operability of the duct detectors. Likewise, upstream and downstream orientation concerns regarding exhaust tubes and sampling tubes are eliminated by implementing the improved duct detector. Furthermore, the improved duct detector allows for self testing with a self test mode. Consequently, the improved duct detector reduces the labor costs and hazards associated with manufacturing, installing, and testing duct detectors.
While the present invention has been disclosed with reference to certain embodiments, numerous modifications, alterations and changes to the described embodiments are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claims. Accordingly, it is intended that the present invention not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof.
|
A particle detection unit including a detection chamber and a duct detector is disclosed. The duct detector is disposed within the detection chamber. The duct detector has a rod with a first and a second end where the first end is distal the second end. A reflector may be attached to the rod adjacent the first end. A sensor and emitter device may be attached to the rod and spaced apart from the reflector.
| 6
|
FIELD OF THE INVENTION
This invention relates to a new rotary clothes hoist which may also be used as a sun umbrella. In particular the invention relates to a clothes hoist which is collapsible or foldable and thus can be stored away when not in use.
DESCRIPTION OF THE PRIOR ART
Rotary clothes hoists which have a number of radially projecting arms supported from a vertical central stem with clothes lines positioned between the arms are known. The clothes lines are attached to adjacent arms in a concentric polygonal array. The more common type of these hoists is not collapsible and consequently suffers the disadvantage that it cannot be removed and thus requires a special area. This disadvantage has been recognized and accordingly a collapsible hoist has been devised which is removable when not in use and which when required may be easily assembled. Both these types of hoists have the disadvantage that the drying effect of a current of air is lessened because of the disposition of the line. Thus the line tends to assume a position wherein parallel sections are shielded from the prevailing breeze. Additionally, the hoist tends to assume an equilibrium position and ceases to rotate.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a clothes hoist which does not suffer from the aforementioned disadvantages.
A further object is to provide a clothes hoist which is foldable, easily removed from a socket, light, and simply and economically constructed.
Thus this invention provides a foldable rotary clothes hoist having an upright support post rotatably mounted in a socket on a base member. A plurality of arms are pivotably connected at one end to the post and extend radially outwardly and an equal number of cooperating tension members are also secured pivotably to the post and are detachably connected to the arms when in operating position. Each arm is adapted to have a line detachably secured to it. The arms, tension members and lines are all capable of being folded down and the entire unit may be removed from the socket member.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The aforementioned characteristics and other advantages will become apparent when regard is had to the following description of a preferred embodiment when taken in conjunction with the accompanying drawings. It is emphasised that the particular structure illustrated is exemplary and not restrictive of the invention.
In the drawings:
FIG. 1 is a perspective view of a clothes hoist in operating position.
FIG. 2 is a view of the clothes hoist after removal.
FIG. 3 is an elevational view showing detail of a hinge.
FIG. 4 shows the end detail of an arm.
FIG. 5 is a plan view of the hinge of FIG. 4.
FIG. 6 is an end view of the arm through x - x of FIG. 4.
FIG. 7 is an elevational view of an alternative preferred embodiment of the upper portion of the hoist.
FIG. 8 is a plan view of FIG. 7.
DETAILED DESCRIPTION
Now having regard to the drawings, numeral 1 represents a tension member for an arm 2. Member 1 may be attached to a ring 5 fixed to the post 6 close to the top thereof and detachably connected to the side of arm 2 in any suitable way. The clothes line 4, which may be of a plastics material is fixed to a lower ring 11 secured to the post 6 and is adapted to be fitted into the end of arm 2 by an end connecting member 3. If desired the member 3 may be permanently fixed to the arm 2 by e.g. welding. The length of the line 4 is such that when operating is taut and properly tensioned. Arm 2 is preferably attached to post 6 by a hinge 10 which enables it to move freely in a vertical plane when tension member 1 is detached.
In FIGS. 7 and 8, the tension member is indicated as 101 and is adapted to fold down over an arm 2 when released from the distal end of 2. It is shown attached onto a flanged member 105 which fits into the support post 6. As shown member 105 is secured in position by a split pin 113. If desired member 105 could fit over the post 6 and if desired be secured by other means, e.g. a bolt. A different arrangement for connecting the arm 2 is also shown. Two circular portions 110 are detachably secured together by locking means 112, e.g. they may be bolted or screwed and each is detachably secured to the main post 6 by fixed means 113, e.g. split pins or a bolt and nut. The arm 2 is pivotably attached to the ring 110 by pin 114 which allows it to fold freely when arm 101 is disconnected from its distal end.
The post 6 is mounted in a socket 9 and is provided with a number of holes 7 for adjusting the height of the line. The post may be secured in position by a pin 8. As can be seen the clothes hoist is free to rotate under the action of a current of air.
As indicated previously the clothes hoist is foldable or collapsible and this may be accomplished by removing the tension member 1 from the arm 2 which is then free to drop close to and approximately parallel to the post 6. The line 4 may be removed from the arm 2 by detaching the connecting member 3. The hoist may be removed from its socket 9 and stored away until needed -- thereby making an area available for other activities.
If desired a suitable canvas or tarpaulin cover may be placed over the hoist so that in its working position it acts as a sun-umbrella. Additionally, a garden table may be so designed as to fit around the post 6.
Whilst the hoist is shown with all arms raised in FIG. 1 and all arms lowered in FIG. 2, it should be realised that not all arms need to be raised when operating and that the hoist may be used if desired with only one arm in operating position.
It should be noted that as the clothes line is radial to the main post, the hoist will tend to rotate under the effect of a current of air and will not assume an equilibrium position. This will increase its drying effect.
It is not intended that this invention be limited to the particular structure shown. Thus the tension member 1 and the line 4 may be fitted to the post 6 in other ways. Similarly the tension member and line may be connected to the arm 2 in other ways and the arm 2 may be connected to the post 6 by other means. It is important that the tension member arm and line are so connected that they are adapted to move freely in a vertical plane so that the hoist may be folded or collapsed to a configuration as schematically shown in FIG. 2.
It may be mentioned that the tension member, arm and line may be fixed to a member (other than a post 6) such as a wall by a suitable means and operate as a clothes drying device.
The components used may be made of any suitable material and if desired galvanized to reduce corrosion. Desirably the total weight of the hoist should be kept as light as is compatible with safety. The main post 6 may be about 11/2 inches diameter, the double ring 110 about 5 inches diameter and its flanged sections each 3/8 inch thick and the arms 5/8 inch diameter and about 6 feet long. A hoist of the above size can conveniently be positioned on a sun-deck or an outdoor area where space is at a premium and is easily folded down and removed when the area is required for other activities.
It is reiterated that the invention is to be given a broad connotation and is not confined to the embodiments described.
|
A rotary clothes hoist which is foldable and may also function as a sun umbrella is described. The hoist has a plurality of extending arms which are held in position by tensioning members and each arm has a clothes line attached. The hoist is arranged for adjustable and removable insertion in a socket thereby facilitating its removal and allowing utilization of the area for other activities.
| 3
|
This application is a Divisional of Ser. No. 367,088, filed June 4, 1973, now U.S. Pat. No. 3,917,553, which in turn is a Continuation of Ser. No. 136,620, filed Apr. 22, 1971, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to the stabilization of polyacrylonitrile compositions. More particularly, the invention relates to the stabilization of polyacrylonitrile compositions containing a low-boiling solvent, which compositions are particularly useful for the formation of shaped acticles such as fibers and films and which have a tendency to develop color either upon standing or upon the application of heat.
The terms "polyacrylonitrile" and "acrylonitrile polymers" as used herein refer to homopolymers as well as copolymers of acrylonitrile containing at least about 85 percent by weight acrylonitrile and up to about 15 percent by weight of at least one other ethylenically unsaturated compound copolymerizable with acrylonitrile.
The utility of acrylonitrile polymers is wellestablished, particularly for the preparation of such shaped articles as fibers and films. However, preparative techniques generally are restricted to dry spinning and wet spinning from solutions having a polymer concentration up to about 25 to 40 percent by weight. Conventional spinning technology, dry spinning in particular, has utilized relatively high boiling solvents, e.g., boiling above about 100° centigrade, for forming spinnable dopes of acrylonitrile polymers. The formation of shaped articles by a melt extrusion process, that is, a process in which the polymer is melted and the molten polymer extruded through a die or spinnerette into an inert medium in contradistinction to dry and wet spinning methods in which a solution of the polymer is extruded through a die or spinnerette, is not practical because of the relatively high melting temperatures of acrylonitrile polymers containing at least 85 percent by weight acrylonitrile and because of the tendency of such polymers to decompose before or during melting.
Acrylonitrile polymers having an acrylonitrile content of at least 85 percent generally are insoluble in the more common solvents. Whenever suitable solvents have been found, however, the application of heat usually is necessary in order to effect solution. The application of heat to effect solution usually results in the development of a pale yellow color in the resultant solution, which color generally darkens and becomes brown with time. Even without the application of heat or upon removal of heat after a solution has been obtained, color develops in solutions upon standing for prolonged periods of time. Color development is more pronounced at elevated temperatures and in the presence of bases or other strong nucleophiles. Color development is most severe in N,N-dimethylformamide solutions such as those employed in dry spinning. Obviously, any color developed in polymer solutions or spinning dopes will be carried over into the products formed therefrom.
The mechanism responsible for color formation and the nature of the chromophores involved still are uncertain. The color may be caused by the presence of metal ions such as iron, copper, and manganese in the polymer solutions. Impurities other than metal ions present in the solvents also have been cited as a cause. The employment of amides, such as N,N-dimethylformamide, as solvents may result in the thermal decomposition of the solvent to give amines which in turn may cause color formation. Or, color formation may be caused by conjugation of carbon -- nitrogen double bonds derived from the cyanide groups in the polyacrylonitrile. Such conjugated double bonds conceivably may result from a cyclization reaction initiated perhaps by oxidation products, such as hydroperoxides, in the polymer. The resultant conjugated structures would be colored because of the low energy electronic transitions possible in the resonating double bond system. Regardless of the mechanism which gives rise to color in solutions of acrylonitrile polymers, e.g., spinning dopes, the presence of color in polymer solutions results in shaped articles which are colored. Such coloration is undesirable for aesthetic reasons and contributes to product non-uniformity.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide stabilized polyacrylonitrile compositions containing a low-boiling solvent.
It is another object to prevent undesirable color formation in polyacrylonitrile compositions containing a low-boiling solvent.
Still another object of the present invention is to minimize color formation in polyacrylonitrile compositions containing a low-boiling solvent when such compositions either are permitted to stand for prolonged periods of time or are heated, either to effect solution of the polyacrylonitrile in the solvent or during spinning of said compositions to provide shaped articles.
Yet another object is to provide stabilized polyacrylonitrile compositions containing a low-boiling solvent from which crystal-clear shaped articles may be prepared wherein clarity and freedom from color are independent of thickness, fiber denier, or the like.
It is also an object of the present invention to provide a method for preparing stabilized polyacrylonitrile compositions containing a low-boiling solvent, which compositions are particularly suited for the formation of shaped articles of polyacrylonitrile.
Yet another object is to provide a method for preparing stabilized polyacrylonitrile compositions containing a low-boiling solvent, which solvent is acetonitrile or an acetonitrile -- water mixture and which compositions can, if desired, be stored or shipped as a solid or gelled material and subsequently formed into a spinning solution or dope for the preparation of polyacrylonitrile fibers and films.
These and other object will be apparent to those skilled in the art from a consideration of the description and claims of the invention which follow.
In accordance with the present invention, stabilized polyacrylonitrile compositions containing a low-boiling solvent are obtained by the process which comprises the steps of adding a minor amount of a stabilizing compound to a solvent which is acetonitrile or an acetonitrile -- water mixture, containing up to about 50 weight percent water, adding acrylonitrile polymer to the solvent -- stabilizer mixture, and heating and mixing the polyacrylonitrile -- solvent - stabilizer mixture under superatmospheric pressure to a temperature above about the boiling point at atmospheric pressure of said solvent and below the degradation temperature of the polyacrylonitrile, i.e., within the range from about 80 to 160 degrees centrigrade to produce a solution. The resultant solution then can be cooled to a temperature below its original solubilizing temperature and above about the boiling point at atmospheric pressure of said solvent without gelation occuring. Cooling the resultant solution to a temperature below about the boiling point at atmospheric pressure of said solvent, e.g., to ambient temperature, results in the gelation of said solution. Preferably, the stabilizing compound is added to said solvent prior to the addition of the polyacrylonitrile to said solvent. Also, the solvent and polyacrylonitrile preferably are purged separately with nitrogen and the pH of the solvent is adjusted to about 6.0 - 7.0.
While the present invention contemplates the use of acetonitrile alone as solvent, it is preferred that an acetonitrile - water mixture be employed as solvent wherein said solvent contains up to about 50 percent water, based on the weight of acetonitrile. Spinning solutions of a stabilized polyacrylonitrile composition of the present invention are obtained by maintaining said composition under sufficient superatmospheric pressure to permit the maintenance of said composition at a temperature above the gel temperature of said composition without distillation of said solvent, said gel temperature being near to but below the boiling point at atmospheric pressure of said solvent.
The aforementioned stabilizing compound is a compound having the following general formula:
X -- S -- Y
wherein X is a monovalent organic radical which may be substituted or unsubstituted selected from the group consisting of alkyl, cycloalkyl, aryl, and combinations thereof; Y is either hydrogen or X; and the total number of carbon atoms contained in both X and Y is in the range of from about 4 to about 20.
DETAILED DESCRIPTION OF THE INVENTION
As indicated hereinbefore, stabilized polyacrylonitrile compositions containing a low-boiling solvent are obtained by the inclusion in said compositions of a minor amount of a sulfur-containing material. By a minor amount is meant less than about 10 percent, based on the weight of polyacrylonitrile, preferably less than about 5 percent, and most preferably from about 0.01 percent to about 3.0 percent. Examples of the sulfur-containing stabilizers of the present invention include, among other, dodecanethiol, mercaptosuccinic acid, cyclohexanethiol, benzenethiol, 1-napthalenethiol, 2-naphthalenethiol, 2-mercaptotoluene, 3-mercaptotoluene, 4-mercaptotoluene, benzyl mercaptan, dipropyl sulfide, diphenyl sulfide, methyl phenyl sulfide, benzyl phenyl sulfide, thiodiglycol, dibehenyl thiodipropionate, distearyl thiodipropionate, diethoxyethyl thiodipropionate, and the like. Preferred stabilizers include dodecanethiol, benzenethiol, thiodiglycol, dibehenyl thiodipropionate, distearyl thiodipropionate, and diethoxyethyl thiodipropionate, with dodecanethiol, benzenethiol, thiodiglycol, and diethoxyethyl thiodipropionate being most preferred.
Included among the sulfur-containing stabilizers of the present invention are types of compounds which have in the past found utility as stabilizers for polyethylene (U.S. Pat. No. 2,519,755), as reactants for the preparation of stabilizers for vinyl resins and synthetic rubbers (U.S. Pat. No. 2,454,568),or as members of stabilizing systems for polyolefins such as polyethylene and polypropylene and vinyl fluoride resins (U.S. Pat. Nos. 2,972,597; 3,038,878, 3,243,408; 3,255,136; 3,413,262; and 3,320,206). In view of the entirely different nature of vinyl resins, vinyl fluoride resins, synthetic rubbers, and polyolefins as compared with the polyacrylonitrile compositions of the present invention, the stabilizing effect of said prior-art-types of compounds is indeed surprising and a theoretical basis for same is not apparent. Also surprising is the fact that said prior-arttypes of compounds effectively stabilize the polyacrylonitrile compositions of the present invention in the absence of any other compound or compounds.
The presence of the sulfur-containing stabilizers of the present invention in polyacrylonitrile compositions containing a low-boiling solvent effectively minimizes color formation in said compositions, even when said compositions are exposed to heat. The effectiveness of said stabilizers, however, usually may be improved by excluding oxygen from said compositions and by adjusting the pH of the solvent to about 6.0 - 7.0. Although various means for excluding oxygen from said compositions and for adjusting the pH of the solvent will be obvious to those skilled in the art, the following procedure is both satisfactory and preferred. The sulfur-containing stabilizer is dissolved in the solvent at ambient temperature. The pH of the resulting solution then is adjusted to 6.0 - 7.0 either by adding an acid such as concentrated sulfuric acid or a base such as sodium hydroxide. Both dissolved and atmospheric oxygen are displaced by bubbling nitrogen through the pH - adjusted solution.
Separately, polyacrylonitrile powder is placed in a vacuum chamber and the chamber evacuated. Nitrogen then is introduced into the chamber. This procedure of evacuation and nitrogen purging is repeated several times as necessary. The polymer and pH-adjusted solution then are brought together and heated under a nitrogen atmosphere to effect solution. The resultant stabilized polyacrylonitrile composition then is either stored or used directly to prepare shaped articles.
As stated hereinbefore, the present invention is directed to the formation of stabilized polyacrylonitrile compositions wherein the polyacrylonitrile contains at least 85 percent acrylonitrile. These acrylonitrile polymers can be acrylonitrile homopolymers as well as copolymers of two or more monomers wherein up to about 15 percent of the polymer can be another ethylenically unsaturated compound which is copolymerizable with acrylonitrile. Such materials which can be monomers or polymers which are copolymerizable with the acrylonitrile usually are added to modify and/or enhance certain characteristics of the polyacrylonitrile or shaped articles made therefrom. Often the material copolymerized with the acrylonitrile contains a chemical group which increases the basic dyeability of the resulting polymer. Such dyeability-enhancing compounds normally contain sulfur or phosphorous in the ethylenically unsaturated material copolymerizable with the acrylonitrile. Typically, such sulfur -- or phosphorous -- containing compounds are added in an amount of from about 0.1 to about 5 percent by weight based on the weight of the total polymer composition. Other modifying substances usually are used in amounts up to about 15 percent. Typical ethylenically unsaturated monomers copolymerizable with acrylonitrile include, among others, methyl acrylate, vinyl acetate, vinylidene chloride, methyl methacrylate, methallyl alcohol, vinylidene cyanide, styrene sulfonic acids, sodium methallylsulfonate, mixtures and partial polymers thereof, and the like, all of which are well known to those skilled in the art. Similarly, acid dyeability may be imparted to the polyacrylonitrile by the use of aminecontaining comonomers such as allylamine. The polymers are obtained by conventional methods which are well known in the art.
The degree to which the polymer is polymerized is dependent upon the end use for which the polymer is intended. Thus, for the spinning of polyacrylonitrile fibers, the polymer preferably is polymerized to an inherent viscosity (measured at 25° centigrade in dimethyl foramide of from about 0.5 to about 2.5 and more preferably from about 1.2 to about 1.8. Of course, polymers having higher inherent viscosities can be used, resulting in higher solution viscosities for a given solvent concentration; higher inherent viscosities also may result in a loss or reduction of certain desirable properties, such as abrasion resistance, fibrillation, and the like.
In most instances wherein the present compositions are most desirably used, solutions having a high concentration of solids are preferred. With the present solvent system and process, solutions having a high concentration of solids are readily obtained with acrylonitrile polymers having inherent viscosities in the range normally used for commercial fiber spinning, i. e., from about 1.2 to about 1.8. In particular, solutions having a solids content of from about 30 to about 70 percent by weight are readily obtained. The more preferred spinning solutions have a solids content in the range of from about 35 to about 55 percent with polymers having inherent viscosities of from about 1.2 to about 1.8 or higher. With polymers having lower inherent viscosities, e.g., from about 0.5 to about 1.2, solutions having a solids content of up to about 70 percent or higher can be obtained.
The solvent may be acetonitrile alone or more preferably an acetonitrile -- water mixture. The addition of water to acetonitrile lowers both the gel temperature of the polymer solution and the initial solution temperature of the polymer. Therefore, in the solvent portion, it is preferable to use up about 50 weight percent of water based on the weight of acetonitrile, more preferably from about 2 to about 40 weight percent water, and most preferably from about 18 to about 35 weight percent water. In the most preferred range of water content, the lowest solution viscosities for a given polymer are obtained.
At atmospheric pressure, the boiling point of acetonitrile is about 82° centigrade and that of the azeotrope of 15 percent water is about 76° centigrade. To form the initial solution, temperatures in excess of the boiling temperature of acetonitrile are used, particularly for the more difficultly soluble acrylonitrile polymers. Consequently, the process is operated under superatmospheric pressure which can be either an applied pressure or the solvent vapor pressure which is developed autogenously at the elevated temperatures. The pressure employed preferably is that required to maintain the solvent primarily in the liquid phase at the solvating temperature. This required pressure increases with increasing temperatures and is in the range of from about 30 to about 40 pounds per square inch gauge at about 100° centigrade. Thus, solvation preferably is conducted in a pressure unit or sealed system to prevent the escape of solvent vapor and to maintain the solvent in the liquid phase.
The solvation temperature required to obtain the compositions of the present invention will vary with the proportions of acetonitrile and water and with the proportion and kind of polyacrylonitrile, within the range of from about 80° to about 160° centigrade. Once solvation is attained, however, the temperature of the composition can be reduced to the desired holding or spinning temperature. Reducing the temperature of the composition below about 80° centigrade, again depending upon the nature of the composition, results in the gelling of the composition. Accordingly, the composition can be either cooled and retained in a gelled state for storage or shipment or maintained in the temperature range of from about 80 degrees centigrade to the degradation temperature of the polymer. If the composition is stored as a gel, it is preferred to retain the composition in a sealed container to reduce or eliminate the gradual loss of solvent therefrom over a period of time.
It may be pointed out that the compositions of the present invention are remarkably stable to prolonged heating. By way of illustration, a composition consisting of 40 weight percent of polyacrylonitrile comprised of 95 percent by weight of acrylonitrile and 60 weight percent of an acetonitrile -- water mixture containing 22 percent water shows practically no change in viscosity after three days at 100 degrees centrigrade.
The following examples will serve to illustrate the invention without intending to limit it in any manner.
EXAMPLE 1
To an autoclave having a stirring means and a heating means and fitted with a condenser and a nitrogen inlet tube extending to the bottom of the vessel are added 60 parts of a solvent consisting of 80 percent by weight acetonitrile and 20 percent by weight water and 0.2 parts (0.5 weight percent, based on the weight of polyacrylonitrile) of benzenethiol. The mixture is stirred at ambient temperature until a solution is obtained. The autoclave then is charged with 40 parts of polyacrylonitrile powder characterized as follows:
95 percent polyacrylonitrile
4.8 percent methyl acrylate
0.2 percent sodium salt of methylallyl sulfonate
The polymer-solvent mixture is heated at 85° centigrade and under a pressure of 2500 mm. mercury for 0.5 hours. The resultant solution, which is comprises of 40 percent solids, has a color rating of 6 after 24 hours at 110° centigrade.
Color rating is determined by comparing the polymer solution with a series of color tubes containing increasing concentrations of a yellow-brown dye, Irgacet Yellow 2RL, in N,N-dimethylformamide. Tube number 1 contains only solvent. Tube number 2 contains 1.0 × 10 -4 percent by weight of the dye. The concentration of dye in each succeeding tube increases by 1.0 × 10 -4 weight percent, so that the dye concentration in any given tube is given by (tube number -1) × 10 -4 weight percent.
For control purposes, the procedure of Example 1 is repeated, except that the addition of benzenethiol is omitted. After 24 hours at 110° centigrade, the polymer solution has a color rating of 41.
EXAMPLE 2
The procedure of Example 1 is repeated, except that the benzenethiol is replaced with an equal amount of dodecanethiol. The polymer solution is slightly turbid and has a color rating of 5 after 24 hours at 110° centigrade.
EXAMPLE 3
The procedure of Example 1 is repeated, except that the benzenethiol is replaced with an equal amount of mercaptosuccinic acid. After 24 hours at 110° centigrade, the polymer solution has a color rating of 16.
EXAMPLE 4
The procedure of Example 1 is repeated, except that the benzenethiol is replaced with an equal amount of thiodiglycol. After 24 hours at 110° centigrade, the polymer solution has a color rating of 6.
EXAMPLE 5
The procedure of Example 1 is repeated, except that the benzenethiol is replaced with an equal amount of dibehenyl thiodipropionate. After 24 hours at 110° centrigrade, the polymer solution has a color rating of 21; the polymer solution is slightly turbid.
EXAMPLE 6
The procedure of Example 1 is repeated, except that the benzenethiol is replaced with an equal amount of distearyl thiodipropionate. After 24 hours at 110° centigrade, the polymer solution has a color rating of 13.
EXAMPLE 7
The procedure of Example 1 is repeated, except that the benzenethiol is replaced with an equal amount of diethoxyethyl thiodipropionate. After 24 hours at 110° centigrade, the polymer solution has a color rating of 10.
EXAMPLE 8
The procedure of Example 7 is repeated, modified as follows: The amount of diethoxyethyl thiodipropionate is reduced to 0.02 parts (0.05 weight percent). The pH of the solvent -- stabilizer solution is adjusted to about 6.0 - 7.0 by the drop-wise addition of concentrated sulfuric acid. Nitrogen then is bubbled slowly through the solution to displace dissolved and atmospheric oxygen. During this time, a vacuum chamber is charged with the polyacrylonitrile powder, evacuated, and nitrogen introduced until atmospheric pressure is attained. The evacuation -- nitrogen introduction cycle is repeated two more times. The polyacrylonitrile powder then is charged to the autoclave under a nitrogen purge; during preparation of the polymer solution, a nitrogen atmosphere is maintained in the autoclave. The color rating of the resultant polymer solution after 24 hours at 110° centrigrade is approximately equivalent to that of the polymer solution of Example 7.
From a reading of the present disclosure, various changes and modifications in the disclosed process will be obvious to those skilled in the art. For example, the pH adjustment of the solvent may be accomplished by the addition of mineral acids other than sulfuric acid or by the addition of anhydrides of mineral acids. The pH adjustment of the solvent also may be accomplished by the use of organic acids, such as carboxylic acids and sulfonic acids. Alternatively, solvent pH control may be accomplished by the use of bases such as sodium hydroxide or by buffers of various types. Furthermore, exclusion of oxygen from the solvent may employ reduced pressures in conjunction with nitrogen purging. These and other changes and modifications by those skilled in the art are considered to be within the spirit and scope of the present invention.
Throughout the foregoing disclosure and the claims which follow, the compositions of the present invention are referred to as solutions of a polymer in a solvent. However, the exact nature of said compositions is not known. It does appear, though, that the acetonitrile portion of the solvent is obsorbed by the polymer to fluidize it, rather than the polymer being dissolved in the solvent. Thus, at least in some instances, said compositions may deviate from typical solutions. In view of the uncertainties involved, the terminology employed is considered satisfactory since such terminology enables any person skilled in the art to make and use said compositions.
|
A method of forming stabilized polyacrylonitrile compositions which are particularly suited for the spinning of polyacrylonitrile fibers and films and the compositions produced thereby wherein acrylonitrile polymers containing at least 85 percent acrylonitrile are dissolved in a solvent which is acetonitrile or an acetonitrile -- water mixture and which contains as a color stabilizer a compound having the following general formula:
X -- S -- Y
wherein X is a monovalent organic radical which may be substituted or unsubstituted selected from the group consisting of alkyl, cycloalkyl, aryl, and combinations thereof; Y is either hydrogen or X; and the total number of carbon atoms contained in both X and Y is in the range of from about 4 to about 20. Preferably, the solvent and polymer are purged with nitrogen and the pH of the solvent is adjusted to about 6.0 - 7.0.
| 2
|
This application is a continuation of U.S. application Ser. No. 14/603,492 filed on Jan. 23, 2015 now U.S. Pat. No. 9,382,960 which claims priority to provisional application 61/941,593 filed on Feb. 19, 2014, the contents of which are incorporated herein by reference.
This invention was made with Government support under Contract No. N65540-10-C-0003 awarded by the Naval Surface Warfare Center. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
This invention relates to a stiffening nonlinear spring formed by a flexible cantilever member wrapping around a curved surface as it deflects.
Several technological processes such as energy harvesting from ambient vibrations, shock absorption from external loads, and passive control or suppression of mechanical instabilities involve targeted energy transfer from one component of a structure to another. In particular, energy harvesting is the process of using ambient energy sources to generate useful forms of energy such as electricity. The energy in these ambient sources is usually spread over a range of frequencies. Applications of energy harvesting may include MEMs sensors implanted in the human body to monitor biological signs and small electronics such as wireless sensors in remote locations. Shock absorption is the process of protecting a primary structure from an ambient force or external pressure load. Applications include passive protection of buildings from earthquake excitations, offshore platforms from water waves impacts, or a delicate instrument from external loads. Passive control of mechanical instabilities is another important area that has recently emerged in the context of targeted energy transfer. Examples may include the suppression of aeroelastic instabilities on wings due to fluttering and the elimination of aeroelastic instabilities in suspension bridges.
In all of these cases, one aims to design elements that are capable of transferring the energy irreversibly and efficiently. In typical applications (especially energy harvesting), the ambient vibration can be described as a stochastic, multi-frequency signal that is often characterized by time-varying features. However, traditional single degree of freedom linear vibration harvesters are efficient only close to their design point; that is, when the excitation frequency matches the harvester's natural frequency. Therefore, linear harvesters respond inefficiently to ambient vibrations. In order to absorb ambient vibrations effectively, it is essential for an energy harvester to be characterized by adaptivity (i.e. the ability to adjust its resonance frequency/ies depending on the input spectrum) and robustness (i.e. the ability to maintain its energy harvesting performance even if the excitation varies significantly).
Methods for overcoming this mistuning problem include: designing systems that do not use a spring, control theory of linear spring systems, 2 degree-of-freedom linear systems, continuous linear systems, and nonlinear springs. Below, we give a critical overview of these techniques, focusing on their different advantages and disadvantages.
Mitcheson et al. [1] describe a micro-scale coulomb-force parametric generator (CFPG) that absorbs ambient energy without using a spring. Instead of using a spring, the CFPG uses a charged capacitor plate that snaps away from a counter-electrode when excited by large accelerations. Since the CFPG does not have a spring, it does not have a resonant frequency and responds similarly to acceleration signals that have the same magnitude but different frequencies. The CFPG, however, only functions well when the excitation displacement greatly exceeds the allowable travel length of its sliding plate. Another shock absorption device that functions without a spring is the MEMS-fabricated hydraulic valve that fits inside a shoe, as described in [2]. A controller allows hydraulic fluid flowing in between two chambers to pulse on a piezoelectric element. Resulting strain in the piezoelectric element converts the mechanical energy into electric energy. Additionally, [3] discusses a device small enough to fit in a shoe that consists of a clamshell made from two piezoelectric elements. The device flattens with each heel-strike. [3] also reviews other energy harvesting devices that absorb ambient energy without vibrating.
The performance (i.e. peak power output, adaptivity, and robustness) of energy harvesters with linear springs can be improved by using control strategies to alter the oscillator's resonance frequency [4] or creating linear devices with two or more degrees of freedom so that they have multiple resonant frequencies [5]. [4] and [5] present devices with better performance than traditional single linear springs. However, the controlled devices consume some of the collected power, and the multiple degree of freedom systems are bulky and have limited robustness.
Another approach is to use a nonlinear spring. Essentially nonlinear springs—that is nonlinear springs without linear stiffness components—do not have preferential linear frequencies. Therefore, they are more robust to variations in the external excitation and preserve their good performance level for a wide range of conditions [6],[7]. The simplest form of an essentially nonlinear spring is a cubic one. It may be implemented by linear springs supporting a proof mass at nonperpendicular angles. For example, MacFarland et al. [8] investigate the dynamics of a nonlinear oscillator realized by a thin elastic rod (piano wire) clamped at its ends without pretension that performs transverse vibrations at its center. To leading order approximation, the stretching wire produces a cubic stiffness nonlinearity. Despite its success in various applications, this design can suffer from significant frictional losses, especially in small scale applications, due to the guided motion of the moving mass [7]. In addition, there are limitations related to the spring breaking or yielding when the external forces become too large.
A different class of nonlinear springs includes those with negative linear stiffnesses, which are usually characterized by bi-stable configurations. Cottone et al. [9] describe a nonlinear spring implemented by an inverted pendulum with a tip magnet that faces an opposing static magnet. For a small enough gap between the magnets, the cantilever has two equilibria. For small base input accelerations, the tip magnet oscillates linearly about one of the equilibria. For sufficiently large accelerations, the tip magnet cycles between the two equilibria. This resonance is insensitive to noise.
As described in [10], nonlinear springs may be physically implemented by helical springs with thickening coil wires or changing overall diameters. Another way to achieve nonlinear behavior is by employing multiple linear components that interact more strongly the further they deflect. For example, in the leaf springs of automobile suspensions, several layers of arc-shaped spring steel are clamped together. As the center of the upper arc deflects, it contacts the arc below it, and both springs further deflect in contact. As more and more arcs deflect, the spring effectively stiffens. However, the many arcs of the leaf spring result in a lot of friction [10].
Mann and Sims [11] describe an oscillator that is implemented by a magnet sliding in a tube with two opposing magnets as the end caps. This configuration causes the stiffness to be the summation of a linear and cubic component. A disadvantage of this device is that the sliding magnet loses energy due to friction as it slides along the tube.
In Manevitch et al [12], an ultrawide bandwidth resonator is made out of a doubly-clamped piezo electric beam. The double-clamps cause the cantilever to stretch as it bends, resulting in a nonlinear stiffness. However, the beam also has a linear stiffness. The linear stiffness is negligible compared to the nonlinear stiffness when the beam's residual stiffness is minimized. Consequently, efforts to minimize the linear stiffness component hinder the system optimization.
A nonlinear spring is also useful for the application of measuring forces as a load cell. Load cells are useful for applications ranging from material strength testing to prosthetic limb sensing (Sanders et al.) [13], monitoring infusion pumps delivering drugs (Mokhbery) [14], agricultural product sorting (Change and Lin) [15], suction cup strength measuring (Messina) [16], and human-robot collision force sensing (Cordero et al.) [17].
Load cells can measure forces via several different methods, including hydraulic or pneumatic pistons and deforming materials. For hydraulic or pneumatic load cells, the force is applied to a piston that covers an elastic diaphragm filled with oil or air respectively, and a sensor converts a pressure measurement to a force measurement. Use of hydraulic load cells is limited by high cost and complexity. Pneumatic load cells are limited by slow response times and a requirement for clean, dry air, Smith [18]. The most common load cells are solid materials that deform when subject to an applied force.
Deforming load cells come in many different shapes, such as bending beams (a cantilever), S-beams (an “S”-shaped configuration of beams), single point load cells (a double-clamped beam, for which the force measurement is insensitive to the position of the load along the beam), shear beam load cells (an I-beam produces a uniform shear 15 across its cross-section that can be measured by strain gauges), and “pancake” load cells (round, at beams) [18]. All of these load cells deflect linearly.
Traditional linear load cells can be designed for almost any force capacity. Bending beam load cells are typically used for force ranges of 5.0×10 −1 to 2.5×10 4 N and pancake load cells can be used for force ranges up to 2.5×10 6 N, Smith [18]. Many linear load cells are designed to withstand a limited amount of force overcapacity using overstops that prevent over-deflection; typically up to 50-500% load capacity before breaking [19]. Because they deform linearly, these load cells also have constant resolution (that is, the smallest force increment that they can measure) for their entire force range.
There are several challenges to designing a load cell. One wants to reduce the load cell mass and volume in order to minimize its effect on the test sample. Additionally, the load cell should have minimal hysteresis for accurate measurements in both up-scale and down-scale, and low side-load sensitivity (response to parasitic loads) [18]. One of the most critical design challenges is the trade-off between force sensitivity and range: It is desirable to maximize strain or deflection in the load cell in order to increase force measurement resolution because strain and deflection sensors have limited resolution; typically 14-bits between 0 and their maximum rated measurement [20, 21, 22]. Simultaneously, one wants to maximize the load cell's functional force range and protect it from breaking due to forces that exceed that range, which requires limiting its strain.
Different studies have made various modifications to the traditional linear load cell to increase its force range and sensitivity, and minimize side-load sensitivity. Chang and Lin [15] studied a “capital G-shaped” load cell with two force ranges: for small forces, a top sensitive flexure deflected alone. For large forces, the sensitive flexure contacted a stiffer flexure, and the two flexures deflected together at the higher stiffness. In this way, the load cell was more sensitive to small forces, and did not yield for large forces. Other devices use multiple linear load cells of increasing stiffnesses in series, as described in several U.S. patents, (Storace and Sette [23], Suzuki et al. [24]). The multiple load cells of a device deflect together until overload stops prevent the weaker load cells from deflecting too far, after which the stiffer load cells continue to deflect. A microcontroller determines which load cell measurement to display. Using this approach, [23] was able to measure weight over a range of 1 g to 30 Kg. One way to minimize sensitivity to side-loads such as undesired moments is to use multiple load cells (i.e. 3) and take the average force measurement [23]. Challenges with these designs are that the linear load cell components have limited resolution, and using multiple load cells in one device may be bulky or expensive.
Another approach for designing a load cell with high force resolution and capacity is to use a nonlinear mechanism rather than a linear one. A nonlinear load cell may have a low stiffness for low forces (and therefore high force sensitivity) and a high stiffness at large forces (and therefore protection from yielding due to over-deflection). The design may also be volume compact and inexpensive due to requiring only one nonlinear spring and sensor per device.
SUMMARY OF THE INVENTION
The present invention is a nonlinear spring that does not have limitations related to factors such as large friction, large volume, many parts which reduce the overall lifetime, or important linear stiffness components. The present invention is useful for purposes such as energy harvesting, shock absorption, and force measurements.
One embodiment considers a cantilever beam that oscillates between two contact surfaces with carefully selected curvature. The resulting nonlinear spring has a negligible linearized component, the order of its nonlinearity does not remain constant but increases as the amplitude gets larger, and the spring achieves a theoretically infinite force for a finite displacement. The last property is of crucial importance since it allows the device to act as a typical spring with polynomial nonlinearity for moderate vibration amplitudes and to effectively behave as a vibro-impact spring for larger amplitudes.
The nonlinear oscillator can be a one-degree-of-freedom oscillator or a component in a multi-degree-of-freedom oscillator. Nonlinear oscillators are useful in targeted energy transfer applications such as ambient energy harvesting because they are adaptive and robust to the stochastic, multi-frequency signals of ambient vibrations. Furthermore, nonlinear oscillators maximize the power dissipated when they have large amounts of damping, whereas linear oscillators tend to maximize the power dissipated for low amounts of damping. For energy harvester applications, an energy harvester with a large amount of damping tends to be more robust to the presence of parasitic damping (less power decay) than a harvester with low parasitic damping.
The nonlinear spring may also be used to make a stiffening load cell. A load cell that uses the present invention has a force resolution that is high for small forces and lower for large forces, which allows a high force accuracy over a large force range. Also, the stiffening behavior and geometry prevent it from breaking for forces well beyond its designed range.
The hardening nonlinearity of the springs in the load cell allow the load cell to deflect a large distance for small forces and incrementally smaller distances for larger forces. For very large forces, the flexible members of the load cell effectively do not bend further because they are already in contact with the surfaces along the full flexible member length. The surfaces are significantly stiffer than the flexible members and can be designed to negligibly deform themselves in all desired applications.
In one aspect, the nonlinear spring according to the invention includes two opposed curved surfaces curving away from one another and a flexible cantilever member disposed between the two opposed curved surfaces. A mass is attached to a free end of the cantilever member wherein the flexible cantilever member wraps around one of the curved surfaces as the cantilever member deflects to form a nonlinear spring. In a preferred embodiment of this aspect of the invention the curved surfaces have a variable radius of curvature along their length. In one embodiment, the curved surfaces have an infinite radius of curvature at their root and radius of curvature decreases with distance from the root. The opposed curved surfaces may include teeth to reduce mechanical damping.
In another aspect, the invention is an energy harvesting device including a flexible cantilever member anchored to a curved surface curving away from the cantilever member. A mass including a permanent magnet is attached to an end of the cantilever member and a fixed coil is located in close proximity to the mass whereby electrical energy is generated as the flexible cantilever member deflects.
In yet another aspect, the invention is a nonlinear load cell including a first member having a symmetrical member with a left and a right curved surface; a second symmetrical member with a left and a right curved surface opposite the first symmetrical member with the curved surfaces curving away from each other. The first member has an anchor point for attachment to an external structure. A second member is displaced parallel to the first member and includes a symmetrical member with left and right curved surfaces and a second symmetrical member with a left and a right curved surface opposite the first symmetrical member with the curved surfaces curving away from each other. The second member has an anchor point to an external structure. A total of four substantially cantilevered beams are provided with first and second sets of left and right cantilever beams projecting from center regions of both first and second members respectively and left and right connection structures connecting left cantilever beam ends and right cantilever beam ends respectively. In a preferred embodiment of this aspect of the invention, the connection structures further include rotational spring elements connecting the cantilever beam ends. It is preferred that strain gauges be applied to the cantilever beams to measure strain. In another embodiment, a linear motion sensor is provided between the first and second members and the connection structure.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side view showing an embodiment in an oscillator application, where there is no force applied to the cantilever tip.
FIG. 2 is a side view showing an embodiment in an oscillator application, where a downward force is applied to the cantilever tip.
FIG. 3 is a side view showing a possible feature modification to the surfaces 2 a and 2 b.
FIG. 4 is a side view showing a possible assembly method of an embodiment in an oscillator application.
FIG. 5 is a side view showing an embodiment as a component in a two degree-of-freedom oscillator application.
FIG. 6 is a side view showing an embodiment as components in a two-degree-of-freedom oscillator application.
FIG. 7 is a front view showing an embodiment in a load cell application, where there is no force applied to the top and bottom.
FIG. 8 is a front view drawing showing an embodiment in a load cell application, where there is a compressive force applied to the top and bottom.
FIG. 9 is a front view showing an embodiment in a load cell application, where there is no force applied to the top and bottom.
FIG. 10 is a front view showing a load cell embodiment when the flexible members of the load cell are naturally curved beams.
FIG. 11 is a cross-sectional view of a nonlinear spring implemented by a cantilever beam that vibrates between two curved surfaces, according to an embodiment of the invention.
FIG. 12 a is a cross-sectional view of an embodiment of the invention disclosed herein showing a load cell with rigid connections and deflected in compression.
FIG. 12 b is a cross-sectional view of a load cell having rigid connections in an undeflected stage with rotational spring connections physically realized by 270° arcs.
FIG. 13 a is a free body diagram of a free cantilever segment in a load cell.
FIG. 13 b illustrates a free cantilever section of the free body diagram.
FIG. 13 c is a three-quarter ring section of the free body diagram.
FIG. 14 is a schematic illustration of a circular load cell in an embodiment of the invention disclosed herein.
FIG. 15 is a free body diagram and schematic of a bottom right quarter of the circular load cell in compression.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a side view of an embodiment of the invention disclosed herein. The embodiment in FIG. 1 has a depth into the page. In this embodiment, a beam 3 a is clamped between top surface 1 a and bottom surface 1 b . In this embodiment, the beam 3 a is a cantilever. In other embodiments, the right end of beam 3 a may have another boundary condition or be attached to another object. In this embodiment, curves 2 a and 2 b are flat at their leftmost ends so that they clamp beam 3 a . To the right of the flat segment, Curves 2 a and 2 b have decreasing radius of curvature along their lengths in the right direction.
FIG. 2 shows that cantilever 3 a wraps around the bottom surface curve 2 b when a downward force is applied to the tip of cantilever 3 a . In this embodiment, for increasing forces, an increasing segment of the cantilever contacts the surface, starting at the root. If an upward force is applied to the cantilever tip 3 a , then the cantilever would wrap around the top surface curve 2 a.
The present invention can be made to be any size and out of a large range of materials. Dimension limitations and applied force limitations are related to the stress in the deflected beams 3 a and rotational springs 20 ( FIG. 9 ).
Other embodiments may have different features. Some of these features may be teeth cut along the curves 2 a and 2 b , as shown on curve 2 n in FIG. 3 . These teeth may be useful for reducing mechanical damping of the oscillator. Other features may be that curves 2 a and 2 b have radii of curvature that do not necessarily decrease as the distance from the leftmost end increases.
Further, the concept of a stiffening member can be extended from a one-dimensional beam 3 a wrapping around a one-dimensional curved surface 2 a or 2 b to a two-dimensional or three-dimensional flexure. For example, the two-dimensional flexure may be a conical coil spring or a plate. The three-dimensional flexure may be a shell, for example. For a two-dimensional flexure, the surfaces 2 a and 2 b may be two-dimensional shapes where the curvature changes as the radius from the origin increases, for example. For a three-dimensional flexure, the surface may be a three-dimensional sphere or ellipsoid, for example.
FIG. 4 shows a possible assembly method of the embodiment. End-mass 4 a may be fixed to the cantilever tip. Holes 6 may be used to bolt bottom surface 1 b to back plate 10 . Slots 5 may be used to bolt surface 1 a to back plate 10 . Holes 8 may be used to bolt top bar 7 to back plate 10 . Bolts 9 a - 9 b may be screwed through holes in the top of top bar 7 so that they push down on surface 1 a . This assembly clamps cantilever 3 a in between the surfaces 1 a and 1 b.
FIG. 5 shows an embodiment of the stiffening spring as a component in a two degree-of-freedom oscillator application. Mass 4 b is connected by spring 13 a to the device outer casing 11 a . Mass 4 b is connected by linear spring 13 a to end-mass 4 a . The embodiment in FIG. 5 may be an electromagnetic energy harvester if masses 4 a and 4 b are magnets. 12 a and 12 b may be coils rigidly attached to outer casing 11 a . Coil 2 c may be rigidly attached to mass 4 b . Mechanical energy may be dissipated due to the relative motion of coil 12 c and mass 4 b when 4 b is a magnet. Mechanical energy may also be dissipated due to the motion of 4 a relative to coil 12 a and of 4 b relative to 12 b when 4 a and 4 b are magnets.
FIG. 6 shows the embodiment as components in a two-degree-of-freedom oscillator application. 4 a is one mass of the oscillator. Surfaces 1 c and 1 d , which are rigidly attached to one another, are the second mass of the oscillator. Spring 13 c connects surface 1 c to the outer casing 11 b , and spring 13 d connects surface 1 d to outer casing 11 b . Spring 13 e connects end mass 4 a to outer casing 11 b.
The present invention may be used as a spring component in other oscillators and systems as well. Other systems may use any number and configuration of the present invention. In energy applications, the present invention may be used with transducers such as electromagnetic systems, piezoelectric systems, and electrostatic systems among others. Electromagnetic system configurations, for example, may use the masses 4 a and 4 b as magnets or coils. The piezoelectric system, for example, may use cantilever 3 a as the piezoelectric element.
In the embodiment shown in FIG. 7 , surfaces 1 f and 1 e are rigid. Rigid vertical bars 15 a connect cantilever 3 e to 3 h and 3 g to 3 f . The rigid vertical bar 15 a may have holes 18 for purposes such as attaching an optical sensor or eddy current sensor 18 a . In the embodiment of FIG. 7 , a sufficiently large compressive force applied to 1 e and 1 f causes beam 3 e to begin to partly wrap around curve 2 e , beam 3 g to begin to wrap around curve 2 g , beam 3 f to begin to wrap around curve 2 m , and beam 3 h to begin to wrap around curve 2 j . In the embodiment of FIG. 7 , a sufficiently large tensile force applied to 1 e and 1 f causes beam 3 e to begin to partly wrap around curve 2 f , beam 3 g to begin to wrap around curve 2 h , beam 3 f to begin to wrap around curve 2 k , and beam 3 h to begin to wrap around curve 2 i.
Surfaces 1 e and 1 f may have holes 16 e - 16 m cut into the roots of surface curves 2 e - 2 m . Holes 16 e - 16 m may be necessary to satisfy manufacturing practices that may not be able to cut a point at the intersections of 3 e with 1 e , 3 g with 1 e , 3 f with 1 f , and 3 h with 1 f . When surfaces 1 e 375 and 1 f have holes 16 e - 16 m , insert 17 may be made to fit into all or some of holes 16 e - 16 m . The presence of insert 17 extends the length of curves 2 e - 2 m.
The top surface 1 e be may be connected to the object of interest while the bottom surface may be connected to the tabletop. The displacement measurements of this load cell embodiment could be measured by an optical sensor or eddy-current sensor that compares the displacement of the top surface 1 e to the bottom surface 1 f . The force acting on the load cell could also be determined by measuring the strain on a strain gage 20 a located on the flexible member 3 or 20 (see FIG. 9 ).
For example, if an optical sensor can detect changes as small as 0.1 μm, then to achieve 1% accuracy in the force measurement requires a change in displacement per force: dy/dF≧1×10 −7 m/0.01F. For F=0.01 N [1 gram], it is desirable, then, to have a stiffness of K=dF/dy≦1000 N/m. For F=1,000 N [100 Kg], it is desirable to have K≦1e8 N/m.
FIG. 8 shows the deflected load cell embodiment when a compressive force is applied on surfaces 1 e and 1 f.
FIG. 9 shows the undeflected load cell with rotational springs 20 connecting the tips of cantilevers 3 and vertical bars 15 b . Rotational spring 20 may be realized by a 270-degree curved beam. The rotational spring 20 may be useful for reducing the stress in deflected beams 3 n , 3 p , 3 q , and 3 r.
FIG. 10 shows an undeflected embodiment of the nonlinear load cell 28 . Curved beams 3 t wrap around rigid outer surface curves 2 n when a compressive force is applied to the rigid surfaces 1 g , 1 h . Curved beams 3 t wrap around the rigid inner surface curves 2 p when a tensile force is applied to the rigid surfaces 1 g , 1 h —possibly via the holes 27 . Load cell 28 may be manufactured from one monolithic part with cut-outs 16 e - 16 m to satisfy manufacturing finite cutting constraints. Interlocking bodies 19 e and 19 f may be used to limit load cell deflection in both tension and compression by contacting each other when a certain deflection between the rigid surfaces 1 g and 1 h has occurred.
The concept of stiffening members 3 e , 3 f , 3 g and 3 h in load cells 24 and 26 , as shown FIGS. 7 and 9 , can be extended from one-dimensional beams 3 wrapping around one-dimensional curved surfaces 2 to two-dimensional or three-dimensional flexures. For example, the two-dimensional flexures 3 may be a conical coil spring or a plate. The three-dimensional flexure 3 may be a shell, for example. For a two-dimensional flexure, the surfaces 2 may be two-dimensional shapes where the curvature changes as the distance from the origin increases, for example. For a three-dimensional flexure, the surface may be a three-dimensional sphere or ellipsoid, for example.
The present invention can be made to be any size and out of a large range of materials. Dimension limitations and applied force limitations are related to the stress in the deflected beams 3 and rotational springs 20 .
Here we briefly summarize the theory for the force, deflection, and stress relationships for designing the vibrating spring and load cells. Designing the spring or load cell maximum stress to remain below a certain value increases its fatigue lifetime. Further details and equation derivations can be found in the journal article J. M. Kluger et al, “Robust Energy Harvesting from Walking Vibrations by Means of Nonlinear Cantilever Beams,” Journal of Sound and Vibrations (2014).
As shown in FIG. 11 , we choose a surface with the curve
S
=
D
(
z
L
Surf
)
n
,
(
1
)
where D is the gap between the surface end and undeflected cantilever, and n is an arbitrary power greater than 2 (a requirement for essential nonlinearity), z is a spatial coordinate measured from the cantilever/surface root, and L Surf is the surface length. The theory derived below should apply to any surface with a monotonically increasing curvature,
ⅆ 2 S ⅆ z 2 .
When a sufficiently larger force F is applied to the beam tip, the cantilever begins to wrap around the surface. The contact point z c is the axial coordinate where the cantilever stops wrapping around the surface and becomes a free beam of length L Free . To the left of the contact point, we assume that the beam is tangent to (equal to) the surface shape given by eq. (1). For the free beam segment to the right of the contact point, the boundary conditions on the beam are
w
(
x
=
0
)
=
S
(
z
c
)
,
ⅆ
w
(
0
)
ⅆ
x
=
ⅆ
S
ⅆ
z
❘
z
=
z
c
,
ⅆ
2
w
(
x
=
L
Free
)
ⅆ
x
2
=
0
,
ⅆ
3
w
(
x
=
L
Free
)
ⅆ
x
3
=
-
F
EI
,
(
2
)
where w is the beam deflection along its free length, F is the force applied to the mass, L Free is the cantilever segment to the right of the contact point z c , EI is the cantilever rigidity, S is the surface shape defined in eq. (1), z c is the contact point between the cantilever and surface for the given force, and x is the spatial coordinate with its origin at z c . Based on Euler-Bernoulli beam theory and solving
ⅆ 4 w ⅆ x 4 = 0 ,
the deflection along the free beam length, x, is
w
(
x
)
=
1
EI
(
S
(
z
c
)
+
ⅆ
S
(
z
c
)
ⅆ
z
·
x
+
FL
Free
2
x
2
-
F
6
x
3
)
.
(
3
)
Substituting x=L Free into eq. (3), the beam tip deflection due to the force F is
δ
=
FL
Free
3
3
EI
+
ⅆ
S
ⅆ
z
❘
z
=
z
c
·
L
Free
+
S
(
z
c
)
,
(
4
)
We can slightly modify eq. (4) to describe the deflection of the end-mass center δ Mass by accounting for the beam tip angle:
δ
Mass
=
δ
+
ⅆ
δ
ⅆ
z
L
Mass
2
,
(
5
)
where L Mass is the length of the undeflected end mass in the z direction. In eq.s (4) and (5), we assume that L Mass is small and causes a negligible moment on the beam tip. Eq.s (4) and (5) and the following equations may straightforwardly be modified for larger L Mass and other beam loading conditions.
The location of the contact point z c along the surface is the point at which the cantilever curvature equals the surface curvature (surface contact condition):
ⅆ
z
S
ⅆ
z
2
❘
z
=
z
c
=
ⅆ
2
w
ⅆ
z
2
❘
z
=
z
c
=
ⅆ
2
w
ⅆ
x
2
❘
x
=
0
.
(
6
)
This is the case because the free cantilever curvature decreases along its length (cantilever gets flatter), while the surface curvature is constant (n=2) or increases (n>2) along its length (surface gets rounder). z c is the point where the surface would no longer prevent the natural curvature of the free cantilever. Alternatively, at z c , the curvature at the root of a free cantilever of length L Free subject to tip force F equals the surface curvature to which it is tangent. The boundary condition defined by Eq. (6) is required for static equilibrium because no external moment is applied to the beam at the contact point.
The free beam length is the full beam length minus the beam length in contact with the surface. Assuming a slender beam, the beam length in contact with the surface is approximately equal to the surface arc length from z=0 to z c . For small deflections, one can assume that L Free =L Cant −z c .
Further using the slender Euler-Bernoulli beam theory, the maximum stress magnitude, σ, in the beam cross-section is
σ
=
-
Ec
ⅆ
2
w
ⅆ
z
2
,
(
7
)
where E is the beam elastic modulus,
C = h 2
is half the beam height and
ⅆ 2 w ⅆ z 2
is the beam curvature. For the beam segment in contact with the surface,
ⅆ 2 w ⅆ z 2
can be found by using w(z)=s(z) and differentiating eq. (1). For the free beam segment,
ⅆ 2 w ⅆ z 2
can be found by differentiating eq. (3).
As shown in FIGS. 12 a and b , each load cell consists of a 2×2 symmetrical grid of nonlinear spring elements. Load cell deflection occurs between the top and bottom rigid blocks. The nonlinear springs are physically realized by cantilevers wrapping around the rigid surfaces as they deflect, splitting each cantilever into a “cantilever segment in contact with the surface” and “free cantilever segment”. The junction between the cantilever segment in contact and free 485 cantilever segment is the contact point, x c . The tips of the bottom cantilevers connect to the tips of the top cantilevers by rigid bars, which cannot rotate due to symmetry. The cantilever tips may be rigidly connected to these vertical bars ( FIG. 12 a ) or connected to the vertical bars by moment compliance rings hereafter referred to as “¾ rings” (the 270° arcs shown in FIG. 12 b ).
Below, we describe the relationship of the ¼ load cell's applied force F, contact point x c , tip moment M Tip , and deflection δ. When F is applied to the ¼ load cell and the ¼ load cell deflects by δ, the complete load cell experiences the applied force 2F and deflection 2δ.
The ¼ surface shape follows the curve
S
=
D
(
x
L
Surf
)
n
,
(
8
)
where D is the gap between the surface end and undeflected cantilever, and n is an arbitrary power greater than or equal to 2, x is a spatial coordinate measured from the cantilever/surface root, and L Surf is the surface length. The theory derived below should apply to any surface with a monotonically increasing curvature,
ⅆ
2
S
ⅆ
z
2
.
Referring to FIGS. 13 a, b and c , the internal moment along the free cantilever segment as a function of distance x from the full cantilever root is
M Internal,Cant =−F ( L−x )+ M Tip , (9)
where F is the applied force on the ¼ load cell, L is the length of the full cantilever, and M Tip is the moment applied at the junction of the cantilever and ¾ ring. The internal moment along the ¾ ring is
M Internal,ring =FR (1+sin φ)+ M Tip , (10)
where R is the radius of the ¾ ring and φ is the angle along the ¾ ring.
Using Euler-Bernoulli beam theory and equating the angle of the cantilever tip to the angle of the ¾ ring at φ=3∅/2, the value of M Tip as a function of the applied force F and contact point x c is
M
Tip
=
(
-
3
Π
R
2
-
2
R
2
+
L
Free
2
)
F
+
2
ⅆ
S
(
x
c
)
ⅆ
x
EI
3
ΠR
+
2
L
Free
,
(
11
)
where L Free ≈L−x c (using small beam deflection approximation) is the free cantilever segment length,
ⅆ S ( x c ) ⅆ x
is the slope of the surface at the contact point found by differentiating eq. (8), and EI is the cantilever and ¾ ring rigidity.
At the contact point, the cantilever curvature must be continuous because there is not an applied external moment. To the left of the contact point, we assume that the cantilever segment in contact with the surface is tangent to the surface. Then, the contact point relates to the applied force F and tip moment M Tip by
ⅆ
2
S
ⅆ
x
2
x
c
=
M
Internal
,
Cant
EI
x
c
→
ⅆ
2
S
ⅆ
x
2
❘
x
c
=
F
(
L
-
x
c
)
-
M
Tip
EI
.
(
12
)
Eq.s (11) and (12) can be simultaneously solved to relate the applied force F, tip moment M Tip , and contact point x c .
Having determined F, M Tip , and x c , the deflection of the ¼ load cell indicated in FIG. 2 relative to the rigid block is the summation of four components:
δ=δ 1 +δ 2 +δ 3 +δ 4 . (13)
The first component is the cantilever deflection at the contact point x c . This deflection component is the vertical location of the surface curve at x c :
δ 1 =S ( x c ) (14)
The second component is the deflection of the free cantilever segment due to the cantilever's slope at the contact point. Since the beam is tangent to the surface at the contact point, its slope equals the surface slope. The free length of the beam rotates by this slope (i.e. small angle) about the contact point, which results in the deflection:
δ
2
=
ⅆ
S
ⅆ
x
❘
x
c
·
L
Free
,
(
15
)
where L Free =L−x c is the length of the free cantilever segment, assuming small deflection and small surface curves, S(x c ). The third deflection component is due to the free cantilever segment bending. Using Euler-Bernoulli beam theory, integrating the moment-curvature relation given by eq. (9), and using boundary conditions that the deflection and slope due to bending equal zero at the free cantilever segment root (the contact point, x c ), this deflection component is:
δ
3
=
FL
Free
3
3
EI
-
M
Tip
L
Free
2
2
EI
.
(
16
)
The fourth deflection component is due to the ¾ ring bending. When an infinitesimal segment of the ¾ ring, δl=Rdφ, bends, it rotates the segments of the ring on either side of it by an angle δθ=Δκδl with respect to each other, where Δκ is the change in the curvature of the beam at the infinitesimal segment due to bending
( Δκ = M Internal , Ring EI ) .
Based on geometry and the small angle approximation, the vertical tip deflection due to this change in angle is the horizontal distance between the infinitesimal segment and the tip, X=R(1+sin φ), multiplied by the change in angle, δθ. Integrating this infinitesimal deflection along the curved beam results in the total deflection of the curved beam due to bending:
δ
4
=
∫
l
Ring
×
δ
θ
→
δ
4
=
(
9
∏
+
8
)
FR
3
+
(
6
∏
+
4
)
M
Tip
R
2
4
EI
.
(
17
)
The ¼ load cell stiffness is K=dF/dδ. The entire load cell stiffness is also K=dF/dδ.
Again using Euler-Bernoulli beam theory, the normal stress in the cantilever segment in contact with the surface can be found by
σ
=
E
h
κ
2
,
(
18
)
where E is the cantilever elastic modulus, h is the beam height, and
κ = ⅆ 2 S ⅆ x 2
(assuming the cantilever segment in contact with the surface is tangent to the surface). The normal stress in the free cantilever segment and ¾ ring can be found by
σ
=
M
Internal
h
2
I
,
(
19
)
where M Internal is the internal moment in the free cantilever segment (eq. (9)) or in the ¾ ring (eq. (10)), his the cross-sectional height, and I is the cross-sectional moment of inertia.
As shown in FIG. 14 , we design a load cell similar to the straight-beam load cell shown in FIGS. 12 a and 12 b but now with curved beams instead of straight beams. The load cell is loaded by a tensile or compressive force, P. We derive the theory for the load cell in compression mode. The theory derived here could be straightforwardly altered for tension mode. The load cell consists of four symmetrical quadrants. In this derivation, we consider the bottom right quadrant, which extends from θ r =0 to θ r =π/2. θ r is the angle along the undeflected curved beam with respect to the vertical.
l
(
Surf
(
θ
s
)
)
=
l
(
Ring
(
θ
R
)
)
→
θ
R
=
l
(
Surf
(
θ
S
)
)
R
0
,
(
20
)
where we assume that the ring arc length equals R 0 θ R . The flexible curved beams have mean radii R 0 . The curved beams have cross-sectional height h which may vary along the angle θ. We may choose to keep h constant along θ R or vary the height along θ R according to
h
=
h
0
+
h
f
-
h
0
(
Π
2
)
q
θ
R
q
,
(
21
)
where q is an arbitrary power. Eq. (21) is valid from 0≦θ R ≦Π/2 and then symmetrical in the other load cell quadrants. The outer rigid surface has shape S out (θ s ) and the inner rigid surface has shape S In (θ s, In ), defined in polar coordinates. The outer and inner surfaces have curvatures κ S and κ S,In , respectively. The rigid surfaces have monotonically increasing curvatures,
ⅆ
2
S
ⅆ
θ
S
2
≥
0.
The load cell may deflect up to a total distance δ max , after which overstops prevent further deflection from additional force. The load cell may be fabricated with gaps if the fabrication technique cannot allow the curved beam root to meet the rigid surface at a point.
Below, we derive the theory for the bottom right quadrant of the circular load cell in compression, shown in FIG. 15 . When P is applied to the entire load cell, P/2 is applied to each load cell quarter due to horizontal symmetry of the load cell quarters. When the quarter load cell deflects by δ/2, the entire load cell deflects by δ due to vertical symmetry of the load cell quarters.
The equation for the internal moment in the z direction along the curved beam as a function of the angle with respect to the vertical, θ R , is
M
=
PR
0
2
(
1
-
sin
θ
R
-
M
D
)
,
(
22
)
where M D is the moment in the z-direction acting at the top of the ¼ load cell.
Next, we determine the relationship of the applied force P/2, moment M D , and contact point θ Rc by simultaneously solving two equations. First, the rotation of the ring at point D with respect to point B must be 0 due to symmetry. That is,
ϕ
D
=
ϕ
c
+
∫
θ
Rc
Π
/
2
Δ
κ
R
0
ⅆ
θ
R
=
ϕ
c
+
∫
θ
Rc
Π
/
2
M
EI
R
0
ⅆ
θ
R
=
0.
(
23
)
φ c is the change in angle of the ring at the contact point:
ϕ
c
=
θ
Rc
-
tan
-
1
(
ⅆ
y
ⅆ
x
❘
θ
Sc
)
,
(
24
)
where θ Rc is the angle of the contact point on the undeflected ring (before the force is applied) and
tan - 1 ( ⅆ y ⅆ x ❘ θ Sc )
is the angle of the surface at the contact point, θ Sc (one way to find the surface angle with respect to the horizontal,
ⅆ y ⅆ x ❘ θ Sc ,
is to convert S(θ Sc ) from polar to Cartesian coordinates).
For the ¼ ring, the internal energy from θ R =0 to the [unknown] contact point θ R =θ Rc , depends on how much the ring curvature changes to match the surface curvature to which it is tangent. This internal energy due to bending is
U
1
=
E
2
∫
0
θ
Rc
I
(
1
R
0
-
κ
S
(
θ
S
)
)
2
R
0
ⅆ
θ
R
,
(
25
)
where E is the curved beam elastic modulus, and I is the cross section moment of inertia (which may be a variable function along θ Rc , i.e. if the cross-section height is defined by eq. (21)). The surface curvature κ S (θ S ) can be converted to a function of θ R using eq. (20).
From the [unknown] contact point θ R =θ Rc to θ R =Π/2, the internal energy depends on the internal moment in the ring that causes bending. This internal energy component is
U
2
=
1
2
E
∫
θ
Rc
Π
/
2
IM
2
R
0
ⅆ
θ
R
,
(
26
)
where the internal moment M is defined in eq. (22). The total internal energy in the ¼ ring is
U=U 1 +U 2 . (27)
Next, we minimize the internal energy U with respect to the contact point θ R . That is, we solve
∂
U
∂
θ
R
=
0.
(
28
)
To find the relationship of the applied force P/2, moment M D , and contact point θ Rc , we may simultaneously solve eq.s (23) and (28) for a fixed force and geometric parameters.
To find the deflection of the ¼ load cell, we rearrange Castiglaino's first theorem into
δ
2
=
∫
0
P
/
2
∂
U
(
F
)
∂
F
F
ⅆ
F
,
(
29
)
where the internal energy is a function of the dummy variable, the applied force, F.
Again, the stiffness of the load cell is K=dP/dδ.
Finally, the equations for stress in the load cell are similar to those of the vibrating spring and straight beam load cell. For the curved beam segment in contact with the rigid surface, the normal stress is
σ
=
Eh
Δ
κ
2
,
(
30
)
where Δκ=R 0 −κ S (θ S ) is the required change in the beam curvature for it to be tangent to the surface. The normal stress in the free segment of the curved beam is
σ
=
Mh
2
I
,
(
31
)
where M is a function of θ R defined in eq. (22) and h may be the function of θ R defined in eq. (21)
A fuller mathematical analysis underpinning the present invention may be found in the provisional application referred to earlier and in J. M. Kluger et al, “Robust Energy Harvesting from Walking Vibrations by Means of Nonlinear Cantilever Beams,” Journal of Sound and Vibrations (2014). The contents of this reference is incorporated herein by reference in its entirety. The numbers in square brackets refer to the references listed herein.
REFERENCES
1. P. Mitcheson, T. Green, E. Yeatman, A. Holmes, Architectures for vibration-driven micropower generators, J. Microelectromechanical Systems, 13 (2004) (3) pp. 429-440.
2. A. Hajati, S. Bathurst, H. Lee, S. Kim, Design and fabrication of a nonlinear resonator for ultra wide-bandwidth energy harvesting applications, in: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMs), 2011, pp. 130-1304.
3. O. Yaglioglu, Modeling and design considerations for a micro-hydraulic piezoelectric power generator, Master's thesis, Massachusetts Institute of Technology (2002).
4. O. Gendelman, T. Sapsis, A. Vakakis, L. Bergman, Enhanced passive targeted energy transfer in strongly nonlinear mechanical oscillators, J. of Sound and Vibration 330 (2011) pp. 1-8.
5. D. Quinn, O. Gendelman, G. Kerschen, T. Sapsis, L. Bergman, A. Vakakis, Efficiency of targeted energy transfers incoupled nonlinear oscillators associated with 1:1 resonance captures: Part i, J. Sound and Vibration (2008) pp. 1228-1248.
6. A. Vakakis, O. Gendelman, L. Bergman, D. McFarland, G. Kerschen, Y. S. Lee, Nonlinear Targeted Energy Transfer in Mechanical and Structural Systems, Springer, 2009.
7. D. McFarland, L. Bergman, A. Vakakis, Experimental study of non-linear energy pumping occurring at a single fast frequency, International Journal of Non-Linear Mechanics 40 (2005) pp. 891-899.
8. X. Tang, L. Zuo, Simulation and experiment validation of simultaneous vibration control and energy harvesting from buildings using tuned mass dampers, in: Proceedings of the American Control Conference, 2011, pp. 3134-3139.
9. F. Cottone, H. Vocca, L. Gammaitoni, Nonlinear energy harvesting, Physical Review Letters (2009) 102 (8) pp. 080601.
10. J. Paradiso, T. Starner, Energy scavenging for mobile and wireless electronics, IEEE 685 Pervasive Computing 4 (1) (2005) pp. 18-27.
11. S. Stanton, C. McGehee, B. Mann, Nonlinear dynamics for broadband energy harvesting: Investigation of a bistable piezoelectric inertial generator, Physica D 239 (2010) pp. 640-653.
12. L. Manevitch, A. Musienko, C. Lamarque, New analytical approach to energy pumping problem in strongly nonhomogeneous 2d of systems, Meccanica (2007) 77-83.
13. J. Sanders, R. Miller, D. Berglund, S. Zachariah, A modular six-directional force sensor for prosthetic assessment: A technical note, J. Rehabilitation Research and Development, (1997) 34 (2) pp. 195-202.
14. J. Mokhbery, Advances in load cell technology for medical applications, Medical Device and Diagnostic Industry newsletter. Accessed online September, 2014.
15. Y.-S. Change, T.-C. Lin, An optimal g-shaped load cell for two-range loading, Engineering in Agriculture, Environment, and Food, (2013) 6(4) pp. 172-176.
16. G. Mantriota, A. Messina, Theoretical and experimental study of the performance of at suction cups in the presence of tangential loads, Mechanism and machine theory, (2011) 46 (5) pp. 607-611.
17. A. Cordero, G. Carbone, M. Ceccarelli, J. Echavarri, J. Munoz, Experimental tests in human-robot collision evaluation and characterization of a new safety index for robot operation, Mechanism and machine theory, (2014) 80, pp. 185-199.
18. J. Smith, Electronic Scale Basics, Key Markets Publishing, 1991.
19. O. E. Limited, An introduction to load cells, history, theory & operating principles (2014). URL http://www.omega.co.uk/prodinfo/load-cells.html
20. Acuity, Principles of measurement used by laser sensors (2014). URL http://www.acuitylaser.com/support/measurement-principles.
21. Lion, Understanding sensor resolution specifications and effects on performance (2014). URL http://www.lionprecision.com/tech-library/technotes/article-0010-sensor-resolution.html
22. Microtrack 3, Tech. rep., MTI Instruments (2014).
23. A. Storace, P. Sette, Leaf spring weighing scale, U.S. Pat. No. 4,037,675.
24. S. Suzuki, Y. Nishiyama, T. Kitagawa, Multi-range load cell weighing scale, U.S. Pat. No. 4,711,314.
|
Nonlinear spring. In one embodiment, the spring includes two opposed curved surfaces curving away from one another. A flexible cantilever member is disposed between the two opposed curved surfaces and a mass is attached to a free end of the cantilever member wherein the flexible cantilever member wraps around one of the curved surfaces as the cantilever member deflects to form a nonlinear spring. Energy harvesting devices and a load cell are also disclosed.
| 5
|
FIELD OF THE INVENTION
[0001] This invention relates to methods for the treatment of fibers, yarns, fabrics and textiles by the generation of a crosslinking architecture on a nanometer or micrometer scale. Such architecture can be applied for treatment of fabrics, yarns and fibers, but not limited to the above, for achieving desired and controlled physical and chemical properties. The invention also extends to fibers, fabrics and textiles so treated
DESCRIPTION OF THE PRIOR ART
[0002] Fiber or fabric treatments for achieving valued added properties are valuable in textiles, home furnishing, and composite materials industries. Particularly in textile industries, various processes have been developed to achieve wrinkle-free/durable-press (DP) properties or antibacterial properties. For examples: U.S. Pat. No. 4,562,097 discloses a continuous process for creating a uniform foamable functional composition that can be used in the treatment of a textile fabric to improve its properties. U.S. Pat. No. 5,614,591 discloses an aqueous durable press treatment composition comprising a reactive modified ethylene urea resin, such as dimethylol dihydroxy ethylene urea (DMDHEU), a crosslinking acrylic copolymer derived from butyl acrylate and acrylonitrile, and a catalyst. This well-known process can be applied either to fabrics prior to fabrication into garments, or as a garment durable press process imparting durable press properties to fabricated garments. U.S. Pat. Nos. 5,856,245 and 5,869,172 disclosed a curable thixotropic polymer to form barrier webs that are either impermeable to all microorganisms or are impermeable to microorganisms of certain sizes or imparts specific properties to the end product material. U.S. Pat. No. 5,874,164 discloses novel barrier webs that have certain desirable physical qualities such as water resistance, increased durability, improved barrier qualities. This process is also based on a curable shear thinned thixotropic polymer composition, including fabrics that are capable of either selective binding certain microorganisms, particles or molecules depending upon what binding partners are incorporated into the polymer before application to the fabric. U.S. Pat. No. 5,885,303 provides a durable press wrinkle-free process which comprises treating a cellulosic fiber-containing fabric with formaldehyde, a catalyst capable of catalyzing the crosslinking reaction between the formaldehyde and cellulose and a silicone elastomer, heat-curing the treated cellulose fiber-containing fabric, under conditions at which formaldehyde reacts with cellulose in the presence of the catalyst without a substantial loss of formaldehyde before the reaction of the formaldehyde with cellulose to improve the wrinkle resistance of the fabric in the presence of a silicone elastomeric softener to provide higher wrinkle resistance, and better tear strength after washing, with less treatment. U.S. Pat. No. 5,912,116 presents a process based a curable shear thinned thixotropic polymer composition to offer water resistance, increased durability, improved barrier qualities of fabrics. U.S. Pat. No. 6,372,674 discloses a textile treatment process imparts water repellant, stain resistant, and wrinkle-free properties as well as aesthetically pleasing hand properties to a fabric made in whole or in part of fibers having a hydroxyl group, such as cellulosic fibers, though immersion in an aqueous bath and subsequent heating for curing.
[0003] Although the above processes, to some extent, achieved the claimed properties, all suffer drawbacks such as the loss of tensile strength, abrasion resistance, and tear strength. Therefore, others have sought improvements using nanotechnology. WO 01/06054 discloses textile-reactive beads, whose inner sphere contains “payload”—for example, anti-biologic reagents, dyes, and UV-protecting agents, that can bind or attach to the fibers of the textiles or other webs to be treated, to provide permanent attachment of the payload to the textiles. In this process, the procedure for getting payload insides the nanobeads, however, is hard to control; the sizes of the nanobeads have wide distribution, which is ineffective to control the post-curing properties; and the resulting structure after treatment is unknown, which makes it difficult achieve desired properties; moreover, the persistent problem of the loss of mechanical strength of the treated textiles remains unsolved.
SUMMARY OF THE INVENTION
[0004] According to the present invention there is provided a method of treating a fabric, yarn or individual fiber comprising the steps of (a) subjecting the fabric, yarn or individual fiber to an aqueous solution containing nanoparticles and a cross-linking agent, (b) drying the fabric, yarn or individual fiber, and (c) curing the fabric, yarn or individual fiber.
[0005] Preferably the nanoparticles comprise first nanoparticles of a first size and second nanoparticles of a second size, the second size being larger than the first. The first nanoparticles may have a diameter in the range of from 18 to 50 nm, and the second nanoparticles may have a diameter in the range of 35 nm to 100 nm.
[0006] The diameter of the first nanoparticles preferably forms a narrow distribution within the preferred range of diameters of the first nanoparticles, and the diameter of the second nanoparticles preferably forms a narrow distribution within the preferred range of diameters of the second nanoparticles.
[0007] In preferred embodiments the number of second nanoparticles in the solution is greater than the number first nanoparticles by a ratio in the range of 1:1 to 4.2:1.
[0008] The nanoparticles may be formed of surface modified polystyrene.
[0009] Preferably the crosslinking agent comprises dimethyl dihydroxy ethylene urea (DMDHEU).
[0010] Preferably the concentration of nanoparticles and cross-linking agent is selected to provide a wet pick-up of 60-70%.
[0011] In preferred embodiments the curing is performed as a single step at a temperature of between 105-170° C. for between 1 to 20 minutes.
[0012] The curing may preferably be performed as a two-step process.
[0013] In one preferred embodiment of the invention prior to step (a) the fabric, yarn or individual fiber is subject to an aqueous solution comprising a cross-linking agent and is then cured under an applied pressure, and wherein the curing of step (c) is carried out under an applied pressure.
[0014] Viewed from another broad aspect the present invention also extends to a fabric material wherein the fibers forming the material are cross-linked by a structure formed of nanoparticles.
BRIEF DESCRIPTION OF THE DRAWING
[0015] Some examples of the invention will now be described by way of example and with reference to the accompanying drawings, in which:—
[0016] FIG. 1 is an illustration of bimodal (two different sizes) nanoparticles on the surface of a fabric for generation hierarchical structures,
[0017] FIG. 2 schematically illustrates nanoparticles on the surface of a yarn for generating hierarchical structures,
[0018] FIG. 3 schematically illustrates nanoparticles on the surface of a fiber for generating hierarchical structures,
[0019] FIG. 4 is a scanning electron micrograph of the narrow-dispersed nanoparticles,
[0020] FIG. 5 is a plot illustrating the size distribution of the nanoparticles,
[0021] FIG. 6 is a scanning electron micrograph of a hierarchical structures of a fiber,
[0022] FIG. 7 is a plot showing the increase of the efficiency for the treatment of fabric by using nanoparticles,
[0023] FIG. 8 is a plot showing the relation between recovery angles and the amounts of nanoparticles used, and
[0024] FIG. 9 is a plot showing a comparision of recovery angle and mechanical properties of untreated samples, samples treated by conventional methods, and samples treated by an embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] The present invention provides a method for creating controlled, hierarchical crosslinking structure on fibers and fabrics using nanoparticles, thus enhancing the mechanical properties of cotton fabrics and other materials made of fibers.
[0026] Several key features and benefits distinguish embodiments of the present invention from the prior art. As shown in FIG. 1 nanoparticles with different sizes (bimodal) were applied on the fabric (details of preferred application methods will be described below) to generate domains with distinct mechanical and chemical properties in a controlled fashion, and thus offer desired enhancements. FIG. 1 is an illustration of the nanoparticles of the two different sizes applied to the surface of a fabric prior to curing. As shown in FIG. 2 , at the level of individual yarns 1 , crosslinking was accomplished by nanoparticles 2 plus conventional crosslinking agents (e.g. DMDHEU). At the level of a fiber, where the fiber 3 is formed from multiple fibrils 4 which may be natural or synthetic, as shown in FIGS. 3 and 6 , the density of crosslinking exhibits three different degrees, thus inducing three regions with different morphologies, which contributes to the control of the mechanical properties. Again the crosslinking between individual fibrils in the fiber is achieved by nanoparticles 5 in the presence of conventional crosslinking agents and a heating step. With regard to the cross-linking agent, DMDHEU is one particularly suitable choice. However, other cross-linking agents can be used as well, for example, small molecules with multiple —COOH groups or —CHO groups. The concentration of DMDHEU is 15˜20% (v:v), catalyst (eg MgCl 2 or ZnCl 2 , with the latter being less preferred for biocompatibility reasons) 6˜20 g/L, and the nanoparticles content 3˜10 g/L. Generally, more DMDHEU and more nanoparticles lead to a higher density of cross-linking. However, it is both the amount of the cross-linking and the mode of the cross-linking (the crosslinking density difference on the surface of a cotton fiber and the core of a fiber as shown in FIG. 6 ) that determine the final performance of the fabric. The amount of nanoparticles used and the sizes of the nanoparticles will affect the mode of cross-linking which is reflected in the recovery angles as can be seen from FIG. 8 to be discussed further below. The essence of this invention is that the use of nanoparticles controls both the modes and the amount of the cross-linking, thus offers improved mechanical properties. An important aspect of the present invention, at least in its preferred forms, is that through the appropriate use of nanoparticles the amount of cross-linking on the surface of the fibers is increased, and the amount of cross-linking in the core of the fiber is minimized.
[0027] The nanoparticles used comprise a mixture of smaller and larger particles. The smaller particles preferably range from 18 to 50 nm in diameter, while the larger particles will range from 35 to 100 nm in diameter. In any mixture used in an embodiment of the present invention the smaller and larger particles are narrowly distributed within their respective size bands (ie although the smaller particles may range between 18 and 50 nm in any exemplary mixture the range of sizes of the smaller particles will be narrower than that), and the number of larger particles will exceed the number of smaller particles by a ratio in the range of 1:1 to 4.2:1. FIG. 4 shows a scanning electromicrograph of suitable nanoparticles and FIG. 5 shows a plot of the size distributions of a preferred example. In this preferred example the smaller nanoparticles have diameters in a narrow band around 33 nm, and the larger particles have a diameter in a narrow band around 40 nm. The size of the nanoparticles can be controlled to provide the foundation for bimodal distribution of the particles on the surface of the fabrics. The nanoparticles and cross-linking agents are provided to the fabric in an aqueous solution, and their amounts are controlled to achieve wet pick-up 60-70%. The curing temperature is preferably from 105˜170° C., and the curing time 1˜20 minutes.
[0028] The function of the nanoparticles is to act as a seed to form a hierarchical nanostructure and any polymer material can be used for the nanoparticles. A suitable material for example is surface modified polystyrene with the surface modification providing the covalent link between the nanoparticles and the fabric. Surface modification may be achieved, for example, by covalently linking —OH or —COOH groups on the surface of the polystyrene during the synthesis of nanoparticles. Other forms of surface modification are possible, however, for example by oxidation of the surface of the polystyrene to form —COOH groups or by reduction to form —OH groups
[0029] For use in the examples below, the polystyrene nanoparticles were synthesized through water emulsion using styrene (ST) and acrylic acid (AA) in a certain weight ratio with or without surfactants at a particular polymerization condition. All emulsion polymerization reactions were carried in a three-neck flask. The flask was equipped with a condenser and inlets for nitrogen. Prior to polymerization, the reaction mixture was degassed by nitrogen flow, and nitrogen was maintained during the synthesis. A typical procedure was follows: 1) Addition of 0.6 g SDS and 0.24 g sodium hydrogen carbonate into 75 ml water to form a solution; 2) addition of 15.6 ml styrene, 2.2 ml acrylic acid and 2.2 ml hydroxyl ethyl methyl acrylate (HEMA) into solution; 3) after 20 minutes stirring, add 0.2 g potassium persulfate (KPS) dissolved in 5 ml water into above solution when temperature increase at 50° C.; and 4) increase the temperature and keep it at 75° C. for another 5 hours until the reaction finished. The morphology of the nanoparticles was examined using a Phillips CM 20 transmission electron microscope (TEM) with an acceleration voltage of 200 kV. The nanoparticles were fished onto a carbon-coated copper grid before examination. Figure shows the TEM results, FIG. 5 shows the size-distribution of the nanoparticles measured by light scattering. This solution of nanoparticles was then used with crosslinking agents (e.g. DMDHEU) for the treatment of the fabrics.
[0030] Table 1 shows the three compositions of the nanoparticles used in the Examples below.
TABLE 1 Sample # 1 2 3 Water (ml) 80 80 90 Styrene (ml) 15.6 5.5 10 Acrylic acid (ml) 2.2 0.5 1 Hydroxyl ethyl 2.2 0 0 methyl acrylate (ml) Potassium persulfate (g) 0.2 0.06 0.11 SDS (g) 0.6 10 0 NaHCO 3 (g) 0.24 0.24 0.12 Temperature (° C.) 75 75 75 Time (h) 5 5 5 Size of the nanoparticles (nm) 21 ± 1.5, 33 ± 1.5, 94˜420 35 ± 1.5 39 ± 1.5
[0031] Using these nanoparticles the following examples were prepared. In each of these Examples the nanoparticles were from Sample 2 above with the sizes and relative numbers as shown in FIG. 4 & 5 :
EXAMPLE 1
[0032] 100% cotton fabric (160 mm×72 mm, 80/2//×80/2 pinpoint oxford) was immersed in an aqueous solution (27 wt % DMDHEU, 1.4 wt % MgCl 2 , 1.5 wt % nanoparticles, and 4.4 wt % commercial softener) and subject to ultrasonic vibration for 1 minute. The fabric was pressed to give a wet uptake of about 70% and then dried at 80-90° C. for 4 hours, and cured at 140˜150° C. for 15 minutes. Then, the properties of the fabric were tested: the recovery angle of treated fabrics was measured according to the AATCC 66 test of option 2; the tensile test was carried out using Instron 4466 following the ASTM D5034 standard. The results of measurements are: Recovery angle 256°.
EXAMPLE 2
[0033] 100% cotton fabric (160 mm×72 mm, 80/2//×80/2 pinpoint oxford) was immersed in an aqueous solution of 1.5 wt % nanoparticles, and subject to ultrasonic vibration for 1 minute. Then an aqueous solution containing 27 wt % DMDHEU, 1.4 wt % MgCl 2 , and 4.4 wt % commercial softener was added in the same solution. The fabric was immersed for 5˜10 minutes and pressed to give a wet uptake of about 70%, then dried at 80-90° C. for 4 hours, and cured at 140-150° C. for 15 minutes. Then, the properties of the fabric were tested as in Example 1. The results of measurements were: Recovery angle 262°, tensile retention (72% wft, 85% wrp), and abrasion 27000 revolution.
EXAMPLE 3
[0034] 100% cotton fabric (160 mm×72 mm, 80/2//×80/2 pinpoint oxford) was immersed in the aqueous solution containing 27 wt % DMDHEU, 1.4 wt % MgCl 2 , and 4.4 wt % commercial softener for 5˜10 minutes. Then 1.5 wt % nanoparticles, were added to the solution and ultrasonic vibration was provided for 1 minute. The fabric as pressed to give a wet uptake of about 70% and then dried at 80-90° C. for 4 hours, and cured at 140-150° C. for 15 minutes. Then, the properties of the fabric were tested as in Example 1. The results of measurements are: Recovery angle 212°.
EXAMPLE 4
[0035] This example is of a two-step constrained curing. The fabric was treated with a solution consisting of 15% DMDHEU, MgCl 2 (6 g/L) for 5˜10 minutes. After the excess solution was removed by padding, the wet take-up of samples is ˜65%. After the fabric was air dried, it was cured at 110° C. for 30 minutes between two flat glass plates with applied pressure. After that, the fabric was treated with a solution consisting of 5% DMDHEU, MgCl 2 (3 g/L), and the nanoparticles (0.5-1.5 wt %) for 5˜10 minutes. After the excess solution was removed by padding, the wet take-up of samples is ˜80%. After the fabric was air dried, it was cured at 160° C. for 3 minutes between two flat glass plates with applied pressure. The measured recovery angle was 270˜284°, the tensile strength 68%˜79%, and the tearing strength 47%˜59%.
EXAMPLE 5
[0036] 100% cotton fabric (160 mm×72 mm, 80/2//×80/2 pinpoint oxford) was immersed in an aqueous solution (30% DMDHEU, 7 wt % MgCl 2 , 0 or 1.5 wt % nanoparticles, and 4.4 wt % commercial softener) for periods of 1, 5, and 10 minutes. The fabric was pressed to give a wet uptake of ˜70% and then dried at 80-90° C. for 4 hours, and cured at 150° C. for 15 minutes. Then, the properties of the fabric were tested: the recovery angle of treated fabrics was measured according to the AATCC 66 test of option 2. Recovery angles are given in FIG. 7 .
EXAMPLE 6
[0037] 100% cotton fabric (160 mm×72 mm, 80/2//×80/2 pinpoint oxford) was immersed in an aqueous solution (30% DMDHEU, 7 wt % MgCl 2 , 0 to 1.8 wt % nanoparticles, and 4.4 wt % commercial softener) and ultrasonic for 1 minute. The fabric was pressed to give a wet pickup of ˜70% and dried at 80-90° C. for 4 hours, and cured at 150° C. for 15 minutes. Then, the properties of the fabric were tested: the recovery angle of treated fabrics was measured according to the AATCC 66 test of option 2. Recovery angles are given in FIG. 8 .
[0038] In these examples the mechanical properties were measured according to existing industrial standards. The recovery angle of the treated fabrics was measured according to the AATCC 66 test of option 2. The grab test was also performed to assess the change of tensile properties of the fibrils after the treatment. The tensile test was carried out using Instron 4466 following the ASTM D5034-1995 standard. The abrasion tests were also carried out under the guideline of ASTM D-4966-1989 standard.
[0039] As shown in FIG. 7 , the time of immersion fabrics in the bath of nanoparticles is reduced, compared to the treatment without nanoparticles, and thus leads to higher efficiency of the process of the treatment. In this Figure the data for the fabric with nanoparticles is as in Example 5. The plot showing a fabric without the use of nanoparticles is obtained from a similar process as in Example 5 but without the application of the nanoparticles and with the application of DMDHEU.
[0040] FIG. 8 illustrates the recovery angle as a function of the pick-up of the nanoparticles, which can be controlled easily by the concentration of nanoparticles. Other than the varying wt % of the nanoparticles, the data of FIG. 8 is obtained using the process of Example 6. A recovery angle of greater than 260° is considered to be indicative of excellent wrinkle-resistance and it can be seen from FIG. 8 that this recovery angle can be equaled or bettered with a wt % of nanoparticles from about 0.02 to at least 1.8 wt %.
[0041] FIG. 9 shows the comparison between non-treated native cotton, conventional treated, and NHCA treated fabric in terms of mechanical properties. And in all physical performance indicators, the NHCA process produces samples with the best result. The data for the “commercial process” fabric is obtained from a fabric treated with a known industrial formulation and sold under the “Brooks Brothers” brand.
[0042] It will thus be seen that the present invention, at least in its preferred forms, provides a method for control the physical and chemical properties of fibers or fabrics via hierarchical crosslinking architecture at nanometer or micrometer scale. The architecture, proved by scanning microscopy study, of the present invention has improved the mechanical properties of a fabric as evidenced by measurement of tensile strength, tear strength, and recovery angle of a cotton fabric. The architecture, which consists a thin film with nanometer or micrometer domains, is generated using nanoparticles and crosslinking reagents. The method of present invention can be applied to various fibers, fabrics, or textiles for enhancing their properties. In comparison with conventional technology, this method gives a well-defined structure, thus offering the potential for property design and control.
|
A method is described for treating fabrics, yarns and individual fibers to improve the mechanical properties thereof, for example their wrinkle-resistance, by treating the fabric, yarn, and fibers in a solution containing nanoparticles. The nanoparticles include two sizes of particles and b appropriate selection of the nanoparticles the degree and mode of cross-linking in the fabric can be controlled with corresponding control of the mechanical properties.
| 3
|
TECHNICAL FIELD
The present invention relates to a method for conveying an emotion to a person being exposed to a media clip.
BACKGROUND OF THE INVENTION
Haptic technology provides an interface to a user via the sense of touch by applying forces, vibrations and/or motions to the user. A typical example of a conventional haptic device is as a game controller. The game controller could, for example, be used to simulate a race car steering wheel by providing a “feel” of the road. As the user makes a turn or accelerates, the steering wheel responds by resisting turns or slipping out of control.
Another possible implementation is in relation to Internet communication, such as for example in relation to communication applications such as ICQ, MSN and the like. Such a system implementation is disclosed in US 2005/0132290, describing a skin stimulation system integrated into a wearable accessory. The system comprises a variety of sensing means for input information. Actuators placed on or close to the body of a person wearing the wearable accessory are used for generating visual auditive, tactile, gustatoric and/or olfactoric stimuli (e.g. heat, pressure vibrational and/or electric pulses, etc.). Through the arrangement simple emotions, such as an emoticon, can be expressed. For example, a smiley, “:-)”, is translated into a short impulse or sequence of impulses at different force actuators, whereas a typical emotional expression such as “I like you” is e.g. represented as “a longer, low-frequency force pressure with maximum heat and a tender pressure”. However, a problem with the above prior art system is that it is too blunt to be applicable for evoking and/or conveying more generic stimulation to a person, for example in relation to generic multimedia information, such as a video clip.
Thus, in view of the above, an object of the invention is to provide a more generic solution for conveying a stimulation to a person, and in particular for enhancing the experience for a person being exposed to a media clip, i.e. watching or listening to a media clip.
SUMMARY OF THE INVENTION
According to an aspect of the invention, the above object is met by a method for conveying an emotion to a person being exposed to multimedia information, such as a media clip, by way of tactile stimulation using a plurality of actuators arranged in a close vicinity of the person's body, the method comprising the step of providing tactile stimulation information for controlling the plurality of actuators, wherein the plurality of actuators are adapted to stimulate multiple body sites in a body region, the tactile stimulation information comprises a sequence of tactile stimulation patterns, wherein each tactile stimulation pattern controls the plurality of actuators in time and space to enable the tactile stimulation of the body region, and the tactile stimulation information is synchronized with the media clip.
Accordingly, an advantage with the present invention is thus that emotions can be induced, or strengthened, at the right time (e.g. synchronized with a specific situation in the media clip) to reinforce a specific happening in the media clip, thereby enhancing the multimedia experience. Multimedia here refers to combinations of content forms such as text, audio, still images, animation, video and interactivity content forms. It could also refer to a single content form such as a radio broadcast containing only audio data. Furthermore, the term media clip here refers to all kind of audio recordings and/or video recordings such as, for example, a radio broadcast, a TV broadcast, a movie on DVD, or an internet movie clip.
The present invention is based on the realization that emotions are powerful sensations that play a vital role in a multimedia experience, and that there typically is a physiological response associated with an emotion, and that this physiological response may be simulated in an advantageous manner by appropriate tactile stimulation of multiple body sites in a body region to induce the emotion to a person. It should be noted that the tactile stimulation according to the invention differs from conventional haptic technology known in the art since the tactile stimulation proposed by the invention simulates a bodily response belonging to an emotion (such as butterflies in the stomach belonging to being in love), whereas conventional haptic devices typically simulate the environment (such as a bumpy road).
Furthermore, the tactile stimulation according to the invention typically has an intrinsic emotional value. Thus, whereas the emotional expressions in prior art arrangements typically are predefined between users (e.g. a short pulse means “happy”, or a long pulse means “I like you”), the tactile stimulation according to the invention is instinctively associated with an emotion.
A body site here refers to a single point of stimulus, such as the area of the body stimulated by a single actuator, or an area stimulated by a ‘virtual actuator’ (i.e. a perceptual illusion that may result when two or more actuators that are closely arranged are properly timed), and a body region here refers to an area of the body comprising a plurality of body sites which can be stimulated to induce an emotion. A body region may typically be a portion of the body such as, for example, an arm, shoulder, back, chest, neck, spine, heart-area, lung-area or belly. This may be advantageous as the bodily response belonging to many emotions are associated with a certain portion of the body, such as sending shivers down a person's spine, or when a person feels butterflies in the stomach. However, a body region may also be a more precise area, such as, the backside of the upper part of the arm, or a more extensive area such as the right arm and the right shoulder, or the entire torso. Furthermore, an actuator should in the context of the application be interpreted broadly, i.e. to a general device for tactile stimulation of a body site. An example of an actuator is a simple vibration motors, similar to those used in mobile phones. Additionally, tactile stimulation is not limited to vibration, but further includes other type of stimulation such as mechanical stimulation, e.g. pressure forces or displacements (perpendicular to the skin) or shear forces or displacements (in the plane of the skin), heat, electrostimulation or TENS (Transcutaneous Electro Nerve Stimulation). Also combinations of pressure, shear and movement like a stroking movement or touch are included.
The tactile stimulation information may further comprise a set of signal shapes, wherein each signal shape provides a drive signal for an actuator. An advantage is that these typically relatively short lived signals may convey some emotional content themselves. For instance, a smoothly (sinusoidal) and slowly varying signal is often perceived as more sad while an abruptly changing signal (e.g. a square wave) gives a more aggressive impression.
At least one of the tactile stimulation patterns may be configured for a first and a second of said plurality of actuators to be timed in a way that a “virtual actuator” occurs in between these actuators. The first and second actuators that are used to generate a “virtual actuator” are typically adjacent actuators. An advantage with using “virtual actuators” is that a better coverage of the body can be achieved with a limited number of real actuators.
In a preferred embodiment of the invention, the emotional state of the person may be registered using a sensor arrangement arranged together with, or separately from, the actuators. The appropriate tactile stimulation pattern can then be played in response to a persons emotional state, i.e. for further enhancing an emotion being felt by the person. An example of this is a person feeling a shivering, the sensors registering the shiver and as a response providing tactile stimulation information that relates to the registered emotion. The sensors typically measure psychophysiological data. Examples of sensors are Galvanic Skin Response (GSR), Electro CardioGram (ECG), Photoplethysmograph (Blood Volume Pulse), Respiratory, Position, Acceleration (e.g. of certain body regions) and Facial Expression sensors.
According to another aspect of the invention there is provided a metadata file comprising multimedia information including at least one of audio information and video information, and tactile stimulation information, wherein the multimedia information and the tactile stimulation information are synchronized in time, and the tactile stimulation information comprises a set of shapes, each signal shape defining a drive signal for an actuator, and a tactile stimulation pattern, configured to control which actuators (in relation to the position of the actuators) are active at a specific time, and for each active actuator specify which signal shape to apply, and a pattern sequence controlling which tactile stimulation patterns that should be applied at a specific time. The shapes can be standardized and/or user defined.
An advantage is that the definitions of the shapes, their timings and their actuation positions on the body are incorporated in the metadata file. It is therefore not necessary to hardcode the shapes in the actuator (or in its associated circuitry). Instead the actuators are just a rendering device for the shapes. This greatly enhances the versatility of the system.
Each shape may have an amplitude over time configured to strengthen an emotion. An advantage is that the individual actuators may be steered with a time varying amplitude to further strengthen an emotion. For instance, a smoothly (sinusoidal) and slowly varying signal is often perceived as more sad while an abruptly changing signal (e.g. a square wave) gives a more aggressive impression. Additionally, the plurality of actuators may together with a control unit form a tactile system for conveying an emotion to a person being exposed to a media clip, wherein the control unit is adapted for processing the metadata file as described above. The system may further comprise a plurality of sensors to register an emotion in a manner as disclosed above.
According to an embodiment of the invention the plurality of actuators are provided in a textile garment, such as, for example, a textile jacket, or vest. An advantage is that a textile garment can be designed to fit tightly, thereby holding the actuators close to the body of the person for an optimal transfer of the tactile stimuli to the skin of the person wearing the garment. It also allows the positioning of the actuators to be tailored to a person's size. Furthermore, the actuators may be arranged in, a bracelet, jewelry piece, watch, glove or other wearable. The actuators may also be arranged in a blanket, a pillow and/or a sofa This enables the actuators to be provided close to the body of a person without requiring that the person wears a specific garment, and may be convenient for example in public environments.
Other objectives, features and advantages will appear from the following detailed disclosure, from the attached dependent claims as well as from the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing currently preferred embodiments of the invention, in which:
FIG. 1 illustrates a tactile stimulation system according to a preferred embodiment of the invention;
FIG. 2 illustrates a detailed view of the positioning of the plurality of actuators on a person's body;
FIG. 3 a provides a conceptual view of a metadata file according to the invention; and
FIG. 3 b provides a conceptual view of a metadata editor for generating a metadata file.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled addressee. Like reference characters refer to like elements throughout.
Referring now to the drawings and to FIG. 1 in particular, there is depicted a tactile stimulation system 100 according to a currently preferred embodiment of the invention. The system 100 comprises a metadata player 102 which is connected to a video rendering device 104 , an audio rendering device 106 , and a tactile rendering device 108 .
The metadata player 102 is an electronic device capable of extracting tactile stimulation information from a metadata file (which is described more fully below in relation to FIG. 2 ) and controlling the tactile rendering device 108 based on this information. Here, the metadata player 102 also has functionality for controlling the video 104 and audio 106 rendering devices based on a media clip contained in the metadata file. However, in an alternative embodiment the metadata player 102 may be a complementary device to a multimedia device, such as for example an conventional DVD, which handles the audio and video rendering devices. The video rendering device 104 and the audio rendering device 106 may be a conventional display device 104 and speakers 106 , respectively.
In the illustrated embodiment, the tactile rendering device 108 is a textile jacket 108 with a plurality of tactile actuators arranged therein. The jacket 108 is preferably designed to fit tightly to a user's body, as this enables an optimal transfer of the tactile stimuli to the skin of the user. The actuators are here simple vibration motors, similar to those used in mobile phones, sewn (e.g. embedded) into the textile jacket 108 . However, a variety of actuators may be used such as various actuators for generating mechanical stimulation, such as pressure forces or displacements (perpendicular to the skin) or shear forces or displacements (in the plane of the skin). Other examples of possible actuators are, heaters (e.g. resistive elements), coolers (e.g. peltier elements), or devices for electrostimulation or TENS (Transcutaneous Electro Nerve Stimulation).
The actuators are steered by electronics that are addressed over a bus structure (not shown). The bus is typically embedded in the jacket 108 . Furthermore, the textile jacket 108 is provided with a transceiver 110 for allowing communication with the metadata player 102 . Although wired communication may be utilized, wireless communication is often preferred for user convenience. The textile jacket 108 is also provided with means for supplying power 112 , such as a battery, and/or a connector for connection to an external power source such a wall socket.
FIG. 2 illustrates a possible layout of 64 actuators 201 1-4 - 216 1-4 , arranged on the upper part of the body of a person wearing the textile jacket 108 . For sake of clarity of the drawing only four of the actuators (i.e. 216 1-4 ) has been provided with reference numerals.
The actuators are here grouped in four, wherein each group of actuators 201 - 216 is provided with a driver (not shown) for steering the actuators. A main connection (not shown), with heavier wiring adapted for larger currents, connects the drivers, whereas smaller, lighter, more flexible wires (not shown) connect the actuators to its respective driver. Utilizing a single driver for a group of actuators allows a large number of actuators to be distributed across the upper body whereas the textile jacket 108 remains flexible and comfortable for the wearer. It also provides additional reliability and current carrying capabilities compared to a situation where all motors would be directly wired to a central driver. The number of actuators per driver may vary, but a suitable number of actuators per driver (in the case of vibration motors) is one to sixteen. To optimize the area of the body which can be stimulated by the actuators, the distance between the actuators is here approximately equidistant.
The actuators can be timed in such a way that a perceptual illusion occurs. (This is further discussed in Geldard et al, The cutaneous “Rabbit”: a perceptual illusion, Science Vol. 178, p. 178; or Geldard et al, Some Neglected Possibilities of Communication, Science Vol. 131, p. 1583.) The illusion results in the feeling of stimulation in between actuators. For instance, with suitable timing of the firing of actuators 216 1 and 216 2 in area 216 (right frontal arm), “virtual touches” on the skin in between these actuators can be achieved. Note that this effect depends on timing only and is, thus, independent of the type of wave form (i.e. the shape) the actuator is steered with. By this “virtual actuators” a better coverage of the body can be achieved with a limited number of actuators. The area of the body stimulated by an individual actuator (e.g. actuator 216 1 ), or by a “virtual actuator”, constitutes a body site.
An area of the body stimulated by a plurality of actuators (real and/or virtual) to induce an emotion is referred to as a body region. As an example, actuator group 216 in FIG. 2 may constitute a body region, i.e. the right frontal arm, stimulated by actuators 216 1 - 216 4 . Other examples of body regions are the spine (actuator groups 208 and 209 ), the back (actuator groups 207 , 208 and 210 ), and the belly (actuators group 205 , 206 , 211 , and 212 ). A body region may also be a more precise area such as the upper part of the right frontal arm (actuators 216 1 and 216 2 ).
As many emotions are associated with a physiological response belonging to that specific emotion (e.g. the feeling of fear may be associated with a physiological response of shivers down the spine) it is often advantageous to focus the actuators around portions of the body that are particularly associated with the specific emotions that the tactile system is designed to convey to the user. Thus, although the actuator layout illustrated in FIG. 2 seek to cover as much of the upper body as possible, the actuators are primarily focused around the belly, the back, the spine, the shoulder, the chest and the arms. Examples of other portions of the body that may be of particular interest for arranging actuators are: heart-area, lung-area, and neck.
As mentioned above, the metadata player 102 can control the actuators based on information contained in a metadata file 300 . A typical structure of the metadata file 300 is illustrated in FIG. 3 a.
The metadata file 300 comprises information from a media clip 302 , here in the form of a video stream 302 containing video and/or audio information, and a tactile data block 304 with information about the tactile stimulation. The video stream 302 may be provided as embedded video data or as a data link to a video stream. Feasible coding standards therefore are well-known in the art. Here, the tactile data block 304 comprises a library of shapes 306 and tactile stimulation patterns 308 .
Each shape 306 in the library defines a signal for steering an individual actuator. The shape is typically a relatively short lived signal (typically on the order of a second) and may be a constant signal or a time varying signal (periodic or not). Examples of shapes are a sinusoidal wave or a square wave. Other examples of shapes are illustrated in FIG. 3 a . However, essentially any suitable arbitrary signal shape is possible and within the scope of the invention. The shapes 306 are preferable referred to by labels, such as a number.
Each pattern 308 in the library is preferably designed to control the actuators to simulate the bodily response belonging to a specific emotion (by means of tactile stimulation of the user's body). In order to do this, the pattern 308 holds a sequence of actuator settings thereby defining which actuators are activated at each point in time throughout the duration of the pattern. The pattern could be implemented as a data array containing the following information: a time followed by a series of elements where each element contains an actuator number, a shape number and an amplitude applied to this actuator. As the actuator number refers to a position on the body it is possible to achieve spatial varying tactile patterns. In this series of elements either all actuators are listed and an amplitude of zero is used to indicate that actuator is not driven or only the actuators that are driven are listed and other are left out. It will be clear to a person skilled in the art that, although a numbering label of actuators is preferred, different schemes can be used to address different actuators.
An illustrative example of a data array for a pattern is provided below on the format: time (second)→(actuator no, shape no, amplitude)
00.00→( 201 1 ,5,1.0)( 201 2 ,1,0.4) . . . ( 212 1 ,0,0)( 212 2 ,0,0) . . . ( 216 4 ,11,1.5) 07.90→( 201 1 ,0,0)( 201 2 ,0,0) . . . ( 212 1 ,5,1.0)( 212 2 ,1,0.4) . . . ( 216 4 ,0,0) 09.81→( 201 1 ,2,2.1)( 201 2 ,0,0) . . . ( 212 1 ,16,2.3)( 212 2 ,0,0) . . . ( 216 4 ,0,0)
. . .
33.33→( 201 1 ,3,1.2)( 201 2 ,4,1.6) . . . ( 212 1 ,3,1.0)( 212 2 ,0,0) . . . ( 216 4 ,8,4)
In this example the first actuator settings lasts for 7.9 seconds (i.e. from time 00.00 to time 07.90). During this time actuator 201 1 is steered with shape 5 and an amplitude of 1.0; actuator 201 2 is steered with shape 1 and an amplitude of 0.4 (of arbitrary unit); and so on. Note that as e.g. actuators 212 1 has an amplitude set to zero it is not active. Then, after the 7.9 seconds have elapsed, there is a new actuator setting which lasts from 07.90 to 09.81, and so on. The patterns could be stored, using techniques for lossless movie compression and/or storage structures available in the art. It is recognized that a duration of a pattern varies, for example, depending on the emotion to be simulated. However, a typical pattern has a duration of a few seconds (typically 1-10 seconds). During the duration of the pattern shapes can be repeated.
The tactile data block 204 also contains a pattern sequence 210 . The pattern sequence defines which pattern to play at which time, to synchronize the tactile stimulation with the content of the video stream. An example could be:
. . .
“play ‘shiver down spine’=pattern no. 1 at 10:00:04 seconds into the movie”
. . .
“play ‘create a heartbeat in the throat’=pattern no. 5 at 10:01:46 seconds into the movie”
. . .
“play ‘butterflies in the stomach’=pattern no. 4 at 31:15:00 seconds into the movie”
. . .
The metadata file 300 can be generated by a metadata editor 320 that combines video information 312 , audio information 314 , tactile stimulation information 316 , and synchronization information 318 (i.e. for synchronizing tactile stimulation to the media clip) as schematically shown in FIG. 3 b . The metadata editor 320 , which for example may be a computer program run on a PC, allows the user to edit the information in the metadata file 300 . Furthermore, the metadata file 300 is preferably generated as a new file, so the content of the original media clip remains unchanged.
A typical application of the tactile system will now be described with reference to FIGS. 1 to 3 . A person wearing the textile jacket 108 watches a movie on a home entertainment system as illustrated in FIG. 1 . The metadata player 102 processes the metadata file 300 , and renders video and audio data contained in the video stream 302 to the TV-screen 2 and to the speakers 3, respectively. Moreover, the metadata player 102 processes the tactile data 304 and plays the tactile stimulation patterns 308 (and the associated shapes 306 ) as prescribed in the pattern sequence 310 . For each pattern played, steering signals are transmitted from the metadata player 102 , via the wireless communication link, to the transceiver 110 in the textile jacket 108 . The steering signals are then distributed via the bus structure in the textile jacket 108 to activate the appropriate actuators, wherein the actuators stimulates the skin of the person wearing the textile jacket. Thus, as a pattern is played the bodily response associated with an emotion can be simulated. As the patterns are synchronized with the content of the media clip, properly timed emotions are conveyed to the person exposed to the media clip thereby enhancing the multimedia experience. For user convenience, the tactile actuators can typically be switched on and off by a mute button.
Examples of emotions that may be induced by means of tactile stimulation are:
send shivers down a person's spine by sequentially driving the actuators that are placed along the spine to enhance feelings of fear. drive the actuators across the arms and shoulders to create the impression of an insect walking on your skin to increase feelings of fear in a different way. drive the actuators in such a way that a person feels butterflies in the stomach like one feels when falling in love. create a heartbeat in the throat when being afraid. implement a comforting stroke when the viewer feels sad. enhance happy feelings with patterns that rapidly vary over the actuators (tickling fingers'). amplify anger with strong and brief outbursts on the actuators. imitate the feeling of a lump in ones throat with a longer steady stimulation at the throat that emphasizing the feeling of sadness.
In an alternative embodiment of the invention, the emotional state of the person may be registered using a sensor arrangement arranged together or separately from the actuators. Depending on the application the sensor arrangement may include sensors for measuring Galvanic Skin Response (GSR), Electro CardioGram (ECG) and/or Photoplethysmograph (Blood Volume Pulse). Other examples are Respiratory sensors, Acceleration sensors and Facial Expression sensors. The sensors enable psychophysiological data to be registered. The registered data can then be interpreted by means of feature extraction followed by classification (e.g. Support Vector Machines). The results are stored as classified emotions. The measured emotions can then be reinforced by using tactile stimulation patterns that belong to that specific emotion. An example of this is a person feeling a shivering, wherein the sensors register the shiver and as a response plays the tactile stimulation pattern that relates to the registered emotion.
According to another embodiment the actuators are implemented in the cushions attached to a couch, or a sofa, wherein the sofa is connected to the metadata player. In this embodiment, the actuators at the front of the body could be implemented in a separate throw pillow or a blanket that the viewer clasps for comfort and warmth. Another embodiment could have the form of a blanket instead of a jacket. Although, this may reduce the accuracy of stimulating the appropriate body region(s), it enhances the ease of use. Yet another embodiment could have the form of a smaller wearable such as a bracelet, a watch or a piece of jewelry. Although the body coverage typically would be limited, it may still convey an emotion to a wearer and enhance the multi media experience. Alternatively, specialized (preferable flexible) wearables could be constructed, such as a glove or armband with similar effects.
Other applications that can be conceived are for instance, therapeutic care for patients with Asperger syndrome or even an autistic spectrum disorder. Another alternative application would be to add additional programs to the metadata player that are specifically designed for massaging the upper body. This application could be combined with, for example, TV-programs that are intended to create a relaxation effect. Yet another application could be the extension of current instant-messaging applications to be able to better convey emotions than the current usage of so called emoticons can achieve.
The skilled person realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the here proposed data structure is pattern based, alternatively one could also devise a data structure that is stream based, i.e. every actuator setting is changed individually at predetermined time intervals. Additionally, although the body region here has been described as being part of the upper body, the invention may equally well be applied to the lower part of the body. Thus, instead of a textile jacket, trousers with embedded actuators may be used, to stimulate body regions, such as, for example a leg or part thereof. Also tactile stimulation of other body part such as e.g. head, feet, and hands would be possible. Furthermore, it is recognized that modifications can be made to the metadata file without departing from the general concept thereof. For example, the shape and/or amplitude for an actuator can be set by the pattern sequence instead of being set by the pattern.
|
The present invention relates to a method for conveying an emotion to a person being exposed to multimedia information, such as a media clip, by way of tactile stimulation using a plurality of actuators arranged in a close vicinity of the person's body, the method comprising the step of providing tactile stimulation information for controlling the plurality of actuators, wherein the plurality of actuators are adapted to stimulate multiple body sites in a body region, the tactile stimulation information comprises a sequence of tactile stimulation patterns, wherein each tactile stimulation pattern controls the plurality of actuators in time and space to enable the tactile stimulation of the body region, and the tactile stimulation information is synchronized with the media clip. An advantage with the present invention is thus that emotions can be induced, or strengthened, at the right time (e.g. synchronized with a specific situation in the media clip).
| 6
|
CROSS-REFERENCES TO RELATED APPLICATIONS
This patent application claims priority to U.S. Provisional Patent Application Ser. No. 61/769,262, filed Feb. 26, 2013, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
Electrical power steering (EPS) systems in vehicles use an electric motor connected to the steering gear or steering column that is electronically controlled to provide a torque to assist a driver in steering the vehicle. EPS systems typically include an electric motor and a controller. The controller receives steering torque information from a torque sensor and controls the motor to transmit assist torque to the wheels, e.g., by applying the torque to the steering column. One type of an electric motor is a Permanent Magnet (PM) brushless motor.
Sinusoidal Brushless Motor Control is a technique used to control brushless motors in EPS systems. Some such techniques utilize a feedforward motor voltage command/control utilizing a steady state representation of the motor characteristics.
SUMMARY OF THE INVENTION
In an embodiment of the invention, a motor control system comprises a motor configured to operate at a rotational velocity and a control module in communication with the motor is provided. The control module is configured to receive a torque command indicating a desired amount of torque to be generated by the motor, obtain a rotational velocity of the motor, receive a desired phase advance angle for driving the motor; and generate a voltage command indicating a voltage magnitude to be applied to the motor based on the rotational velocity of the motor, the motor torque command, and the desired phase advance angle by using a plurality of dynamic inverse motor model equations that (i) allow the desired phase advance angle to exceed an impedance angle of the motor and (ii) specify that the voltage magnitude is a function of a voltage magnitude of a previous voltage command.
In another embodiment of the invention, a method for controlling a motor of an electronic power steering (EPS) system comprises receiving a torque command indicating a desired amount of torque to be generated by the motor. The method obtains a rotational velocity of the motor. The method receives a desired phase advance angle for driving the motor. The method generates a voltage command indicating a voltage magnitude to be applied to the motor based on the rotational velocity of the motor, the motor torque command, and the desired phase advance angle by using a plurality of dynamic inverse motor model equations. The inverse motor model equations allow the desired phase advance angle to exceed an impedance angle of the motor and specify that the voltage magnitude is a function of a voltage magnitude of a previous voltage command.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is an exemplary schematic illustration of a motor control system in accordance with exemplary embodiments;
FIG. 2 is a phasor diagram of a motor in accordance with exemplary embodiments;
FIG. 3 is a diagram illustrating the four quadrants of operation for a motor in accordance with exemplary embodiments;
FIG. 4 a is a block diagram that illustrates calculation of desired d-axis current in accordance with exemplary embodiments;
FIG. 4 b illustrates lookup tables for finding desired d-axis current in accordance with exemplary embodiments;
FIG. 5 a is a block diagram that illustrates calculation of a voltage command in accordance with exemplary embodiments;
FIG. 5 b is a block diagram that illustrates calculation of a desired amount of direct axis current in accordance with exemplary embodiments;
FIG. 6 a illustrates an implementation of a derivative filter in accordance with exemplary embodiments;
FIG. 6 b illustrates an implementation of a derivative filter in accordance with exemplary embodiments;
FIG. 7 illustrates an implementation of a low pass filter in accordance with exemplary embodiments;
FIG. 8 is a block diagram that illustrates calculation of a voltage command in accordance with exemplary embodiments;
FIG. 9 is a block diagram that illustrates calculation of a final voltage command in accordance with exemplary embodiments; and
FIG. 10 is flow diagram illustrating a motor control method in accordance with exemplary embodiments.
DETAILED DESCRIPTION
Embodiments of the invention provide a controller for controlling a motor of an electric power steering (EPS) system by supplying a voltage command at a phase advance angle up to 90 degrees and beyond 90 degrees (i.e., the phase advance angle above the impedance angle of the motor). The controller uses a motor model that includes equations for calculating a voltage command based on inputs that include a motor velocity, a torque command, and a phase advance angle. The controller receives the inputs, calculates voltage commands specifying required voltages according to the motor model, and sends the voltage commands to the electric motor to control the torque generated by the motor. In one embodiment, the motor model allows for calculating the voltage commands even when the torque generated from the motor voltage is opposite to the rotational direction of the motor (i.e., when the motor operates in quadrant II and IV) and the phase advance angle is up to or greater than 90 degrees. In one embodiment, the motor model allows for such calculation by limiting motor regenerative current in quadrants II and IV.
Referring now to the Figures, where the invention will be described with reference to specific embodiments, without limiting same, FIG. 1 illustrates a motor control system 10 in accordance with one aspect of the invention. In the exemplary embodiment as shown, the motor control system 10 includes a motor 20 , an inverter 22 , a supply voltage 24 , and a control module 30 (also referred to as a controller). The voltage supply 24 supplies a supply voltage V B to the motor 20 . In one embodiment, the voltage supply 24 is a 12 volt battery. However, it is to be understood that other types of voltage supplies may be used as well. The inverter 22 is connected to the motor 20 by a set of three connections 32 that are labeled as ‘A’, ‘B’ and ‘C’. In one embodiment, the motor 20 is a polyphase, permanent magnet (PM) brushless motor. In this example, the motor 20 is a three-phase PM motor. The control module 30 is connected to the motor 20 through the inverter 22 . The control module 30 receives a motor torque command T CMD from a source 34 such as, for example, a steering control system. The control module 30 includes control logic for sending a motor voltage command V LL to the motor 20 through the inverter 22 .
Referring now to FIGS. 1 and 2 , the motor 20 is operated such that a phase of the motor voltage command V LL shifts with respect to a phase of a developed back electromotive force (BEMF) voltage E g of the motor 20 . A phasor diagram of the motor 20 is shown in FIG. 2 and illustrates a voltage vector V having a magnitude that is the motor voltage command V LL . A BEMF voltage vector E has a magnitude that is the BEMF voltage E g . An angle between voltage vector V and the BEMF voltage vector E is defined and is referred to as a phase advance angle δ. A stator phase current is referred to as I, a stator phase current in the quadrature axis (q-axis) is referred to as I q , a stator phase current in the direct axis (d-axis) is referred to as I d , a stator phase reactance in the respective d-axis is referred to as X d , the stator phase reactance in the q-axis is referred to as X q , and a stator phase resistance at phase A is referred to as R a .
In one embodiment, an encoder 36 (shown in FIG. 1 ) is used to measure an angular position θ of a rotor (not shown in FIG. 1 ) of the motor 20 . The angular position θ of the motor 20 is used to determine the input phase voltages V a , V b and V c , where input phase voltage V a corresponds with connection A, input phase voltage V b corresponds with connection B, and input phase voltage V c corresponds with connection C. The control module 30 includes control logic for calculating input phase voltages V a , V b , and V c by the following equations:
V a =V sin(δ+θ) Equation 1
V b =V sin(δ+θ+120°) Equation 2
V c =V sin(δ+θ+240°) Equation 3
The motor 20 rotates in a clockwise as well as a counterclockwise direction, and may also produce torque in both the clockwise and counterclockwise direction during operation. Therefore, the motor 20 is capable of operating in all four quadrants of operation, which is illustrated in FIG. 3 . FIG. 3 is an exemplary diagram illustrating the four quadrants of operation for the motor 20 , where quadrant I includes positive velocity and positive torque, quadrant II includes negative velocity and positive torque, quadrant III includes negative velocity and negative torque, and quadrant IV includes positive velocity and negative torque. In the event that the motor 20 is operating in either quadrant II or quadrant IV, the motor 20 may create a regenerative current that is sent back into the DC power supply 24 (shown in FIG. 1 ).
The control module 30 includes control logic for monitoring the motor 20 for a rotational velocity. Specifically, the control module 30 may be in communication with a speed measuring device (not shown in FIG. 1 ) that provides an output indicating an angular velocity ω m of the motor 20 . Alternatively, the angular velocity ω m of the motor 20 may be calculated by differentiating the angular position θ, where dθ/dt=ω m . The angular velocity ω m may also be referred to as the mechanical velocity of the motor 20 , and is measured in radians/second. The control module 30 also includes control logic for also calculating an electrical velocity ω e of the motor 20 , where the electrical velocity is calculated by multiplying the mechanical velocity ω m by a number of poles N p of the motor 20 , and dividing the product of the mechanical velocity ω m and the number of poles N p by two.
In one embodiment, a memory (not shown) of the control module 30 stores several motor circuit parameters. Specifically, in one embodiment, the motor circuit parameters include a motor voltage constant K e that is measured in volts/radian/second, a motor and control module output circuit resistance R that is measured in Ohms, and motor inductances L q and L d that are measured in Henries. In another embodiment, the control module 30 may include control logic for calculating the motor circuit parameters including motor voltage constant K e , the motor and control module output circuit resistance R, and the motor inductances L q and L d . In such an embodiment, the control logic may adjust the calculated motor output circuit resistance R and the calculated motor voltage constant K e based on the temperature of the motor. The control logic may also adjust the calculated motor voltage constant K e and the calculated motor inductances L q and L d with respect to the motor current in order to comprehend the saturation effects. The control module 30 also includes control logic for monitoring the supply voltage V B to the motor 20 .
In an embodiment, the control module 30 is configured to generate a voltage command using a motor control model. An example of a motor control model for a sinusoidal permanent magnet (PM) motor includes the following equations:
V cos ( δ ) = Vq = ( L q R s + 1 ) RI q + K e ω m + L d ω e I d Equation 4 - V sin ( δ ) = Vd = ( L q R s + 1 ) RI q - L q ω e I q Equation 5 T e = K e I q Equation 6
where:
V is the magnitude of the voltage applied to the motor, i.e., the motor voltage V LL ; V q is the q-axis vector component of motor voltage in phase with the motor BEMF; V d is the d-axis vector component of motor voltage 90 degrees out of phase with the motor BEMF; δ is the angle of the applied voltage relative to the BEMF in radians (the phase advance angle); L q and L d are the stator q-axis and d-axis inductances, respectively (Henries); R is the motor circuit resistance, including the motor stator and controller hardware (Ohms); K e is the motor voltage constant (Voltage/Radian/second); ω m is the rotor mechanical velocity (Radian/second); ω e is the rotor electrical velocity (Radian/second); I d is the direct (d) axis current (Amperes); I q is the quadrature (q) axis current (Amperes); T e is the electromagnetic torque (Newton meter); and s is the Laplace operator.
Setting the desired motor torque command T CMD equal to T e in the above equations 4-6 and solving for the voltage and phase advance angle required to deliver the desired torque yields the following:
V
q
=
T
CMD
R
K
e
(
L
q
R
s
+
1
)
+
K
e
ω
m
+
ω
e
L
d
R
(
T
CMD
K
e
ω
e
L
q
-
V
sin
(
δ
)
L
d
R
s
+
1
)
Equation
7
V
d
=
R
(
L
d
R
s
+
1
)
(
V
cos
(
δ
)
-
T
CMD
R
K
e
(
L
q
R
s
+
1
)
-
K
e
ω
m
ω
e
L
d
)
-
T
CMD
K
e
ω
e
L
q
Equation
8
In one embodiment, the control module 30 is configured to use the equations 7 and 8 to solve for the final motor voltage magnitude V (i.e., V LL in FIG. 1 ) for all four quadrants. For the quadrants I and III, the control module 30 uses the equation 7 to solve for V q and to divide V q by cosine of the phase advance angle as shown in the following equation 9:
V = V q cos ( δ ) Equation 9
For the quadrants II and IV (e.g., when the phase advance angle is over 90 degrees), the control module 30 uses the equations 7 and 8 to solve for V q and V d and uses the V q and V d in the following equation 10:
V= Sign( V q )√{square root over ( V q 2 +V d 2 )} Equation 10
where Sign( ) is a function that outputs the sign (e.g., positive or negative) of a value. It is to be noted that the control module 30 may use the equation 10 to compute the final motor voltage magnitude V for all four quadrants I-IV.
In an embodiment, the control module 30 uses a simplified equation to calculate the final voltage magnitude. Specifically, the equation 8 for calculating V d may be simplified by using a directly-commanded d-axis current I d . That is, using a directly commanded value as I d instead of using I d as a variable in the equation 8 allows for avoiding the implementation of the double derivative operation (i.e.,
( L q R s + 1 ) × ( L q R s + 1 )
for
T CMD R K e )
of the equation 8. Calculating I d in order to directly command I d is described further below by reference to FIGS. 4 a and 4 b.
In an embodiment, the control module 30 implements the following equation 11 to avoid a double derivative operation:
V d = I d_des 3 2 R ( L d R s + 1 ) - T CMD K e ω e L q Equation 11
The control module 30 may be configured to use the equations 7 and 11 to solve for the final motor voltage magnitude V for all four quadrants. For quadrants I and III, the control module 30 uses the equation 7 to solve for V q and uses the V q value in the equation 9 to solve for V. For quadrants II and IV, the control module 30 uses the equations 7 and 11 to solve for V q , and V d , and use the V q , and V d values in the equation 10 to solve for V.
The equation 11 includes an I d _ des value that represents a desired amount of I d current. I d _ des may be a signal from a phase control sub-function representing the desired d-axis current I d . This desired amount of I d current, in one embodiment, is calculated as an input to a regenerative current limiting function. An example of such a function is described in U.S. Patent Application Publication No. 2013/0154524, entitled “Motor Control System for Limiting Regenerative Current,” filed on Dec. 15, 2011, the entire contents of which are incorporated herein by reference. A regenerative current limiting function is also described further below after the description of FIG. 11 .
An exemplary motor control system as described in the above-incorporated U.S. Patent Application Publication No. 2013/0154524 provides techniques for limiting negative supply current, or regenerative current, that is produced by an electric motor when operating in either quadrant II or quadrant IV. The system calculates a value of a target field weakening current I dTARGET , which is used as an input to calculate a motor voltage. The value I d _ des may be used by the system as the I dTARGET current.
In one embodiment, the equations 7, 8 and 11 for V q and V d above include derivative terms (e.g.,
T CMD R K e ( L q R s + 1 )
and
I d_des 3 2 R ( L d R s + 1 ) ) .
Discretizing a derivative can produce noise due to sampling and resolution effects at high frequencies. To address the noise, the controller 30 of one embodiment includes a digital filter (not shown in FIG. 1 ) to implement the derivative function utilizing a Fourier Series representation of a derivative with a Hamming window applied.
FIG. 4 a is a block diagram that illustrates an implementation of desired d-axis current I d _ des calculation module 400 . This d-axis current is calculated for directly commanding the I d . This directly commanded I d _ des is used for V d calculations (e.g., in the equation 11) for quadrants II and IV only. In one embodiment, I d _ des 405 is a function of the motor velocity ω m 410 and the absolute value of the torque command T CMD 415 as shown. In one embodiment, a sign block 425 identifies the sign (e.g., positive or negative) of the torque command T CMD 415 , and the multiplier 430 multiplies the motor velocity ω m 410 by the sign value (e.g., −1 or +1) of the torque command T CMD 415 . In one embodiment, the resulting product is used to look up values from a look up table. The sign of this resulting product indicates the quadrant in which the motor is operating. For instance, when the sign of the resulting product is negative because the sign of the torque command is opposite to the sign of the motor velocity, the motor is operating in quadrants II or IV. When the sign of the resulting product is positive because the sign of the torque command is the same as the sign of the motor velocity, the motor is operating in quadrants I or III. The absolute value block 435 takes the amplitude of the torque command T CMD 415 and the amplitude is used to select a look up table.
In one embodiment, I d _ des can be determined from a set of calibratable, interpolated, fixed x, variable y lookup tables depicted as curves in a graph 420 , each defined at a specific torque command. In one embodiment, the x-axis of the graph 420 represents the motor velocity multiplied by the sign of the torque command and the y-axis of the graph represents the desired current I d _ des . FIG. 4 b illustrates exemplary lookup tables depicted as curves 440 - 470 in a graph 475 . The x-axis of the graph 475 represents the motor velocity multiplied by the sign of the torque command in revolutions per minute (RPM). The y-axis represents the desired current I d _ des in amperes. In one embodiment, when the amplitude of the torque command does not exactly match any of the torque command amplitudes for the different curves, an interpolation technique is employed to find the desired current I d _ des value. In one embodiment, when the motor velocity multiplied by the sign of the torque command is positive (i.e., when the motor is operating in quadrants I or III), I d _ des is set to zero. The corresponding portion of the graph is not depicted in FIG. 4 b.
FIGS. 5-10 illustrate exemplary implementations of the equations 7, 8, and 11 for calculating voltage commands. Specifically, FIGS. 5 a and 5 b illustrate an exemplary approach for calculating V q (i.e., using the equation 7) and other terms of the equations 8 and 11. Implementations of static versions of the equations 7, 8, and 11 (i.e., without the derivative term s) are described in the above-incorporated U.S. Patent Application Publication No. 2013/0154524. An exemplary implementation of the equation 7 is also described in U.S. Pat. No. 7,157,878, the entire content of which is incorporated herein by reference.
FIG. 5 a is a block diagram that illustrates an implementation of a voltage command calculation module 500 . Specifically, this module 500 calculates V q 595 according to the equation 8 in one embodiment. As shown, the module 500 takes as inputs the torque command 415 , the motor velocity ω m 410 , and a phase advance angle δ 599 , and outputs V q 595 .
An R/K e block 515 , an L q /R block 520 , a derivative filter 525 , and an adder 527 together implement the first term
T CMD R K e ( L q R s + 1 )
of the equation 7. Exemplary implementations of the derivative filter 525 are described further below by reference to FIGS. 6 a and 6 b . A K e block 530 implements the second term K e ω m of the equation 7. A L q /R block 535 , a pole number block 540 , an L q /R block 550 , a low pass filter (LPF) 555 , a sine block 560 , multipliers 565 - 580 , and an adder 585 together implement the third term
ω e L q R ( T CMD K e ω e L q - V sin ( δ ) L d R s + 1 )
of the equation 7. An exemplary implementation of the LPF 555 is described further below by reference to FIG. 7 . In one embodiment, the LPF 555 may be bypassed.
The phase advance angle δ 599 that the sine block 560 takes as an input may be calculated by an I d _ des calculation block, which will be described further below by reference to FIG. 5 b . The motor electrical velocity ω e 542 is related to the motor mechanical velocity ω m 410 and the number of motor poles by the equation ω e =(number of motor poles N p /2)×ω m . The first, second, and third terms of the equation 7 is summed by an adder 590 to output V q 595 of the equation 7.
FIG. 5 b is a block diagram that illustrates calculation of I d _ des Specifically, FIG. 5 b illustrates an I d _ des calculation block 513 . The I d _ des calculation block 513 is similar to the I d _ des calculation module 400 for quadrants II and IV described above by reference to FIG. 4 a . The I d _ des calculation block 513 takes as inputs the torque command 415 , the motor velocity ω m 410 , a supply voltage 503 , and a set of motor circuit parameters 508 . The I d _ des calculation block 513 calculates the I d _ des 405 and the phase advance angle δ 599 . In one embodiment, the set of motor circuit parameters 508 includes an estimation of the motor circuit resistance R, an estimation of the q-axis stator inductance L q , an estimation of the d-axis stator inductance L d , an estimation of the motor voltage constant K e , and a number of poles of the motor N p .
FIG. 6 a illustrates an exemplary non-recursive implementation of the derivative filter 525 of FIG. 5 in various embodiments. The derivative filter 525 may be used for calculating derivative terms of the equations 7, 8, and 11. For different derivative terms from different equations, the values of the derivative input 605 would be different. Also, the gain values that the derivative filter gain block 610 uses would be different for calculating the different derivative terms. In one embodiment, the gain values are in a range of float 0-200. In one embodiment, the V q filter coefficients include six constants, which are depicted in FIG. 6 as C 0 , C 1 , C 2 , C 4 , C 5 , and C 6 . Different sets of these constants are used for calculating the different derivative terms in one embodiment. It is to be noted that, in this example, the derivative filter 525 is non-recursive—i.e., not reusing the output as an input. In one embodiment, the derivative filter 525 is a finite impulse response (FIR) filter.
FIG. 6 b illustrates another exemplary implementation of the derivative filter 525 of FIG. 5 in various embodiments. Compared to the implementation illustrated in FIG. 6 a , the implementation illustrated in FIG. 6 b is simplified by having a symmetric structure for the filter coefficients. For example, C 6 is set to −C 0 , C 5 is set to −C 1 , and C 4 is set to −C 2 . Having such symmetric coefficients limits the number of multiplication operations (i.e., from six to three as indicated by the six multipliers 625 - 640 in FIG. 6 a and the three multipliers 655 - 665 in FIG. 6 b ) and enforces the symmetry of the coefficients (i.e., prevents a set of six coefficients that are not symmetric from being loaded).
FIG. 7 illustrates an exemplary implementation of the LPF 555 of FIG. 5 . As shown, an output of the LFP 555 is calculated based on inputs 745 and 750 . In one embodiment, the input 745 is L d /R and the input 750 is
T CMD K e ω e L q - V sin ( δ ) .
In one embodiment, the LPF 555 also includes a look up table 705 to find a cut off value for the input 750 based on the input 745 . In one embodiment, a ratio of one millisecond and the input 745 is used to find the cut off value from the look up table 705 . Alternatively, in one embodiment, the look up table 705 may be replaced with an equation
1 - e - T τ ,
where T is a sampling time period (e.g., one millisecond) and τ is the input 745 . The rest of this exemplary implementation of the LPF includes a multiplier 720 , adders 725 and 730 , and 1/Z blocks 735 and 740 . In one embodiment, the initial conditions for the 1/Z blocks 735 and 740 are set to zero.
FIG. 8 is a block diagram that illustrates an implementation of a voltage command calculation module 800 . Specifically, this module 800 calculates V d 895 according to the equation 11 in one embodiment. As shown, the module 800 takes as inputs the torque command 415 , the motor velocity ω m 410 , and the directly commanded I d _ des 405 .
A square root(3)/2 block 805 , the L q /R block 535 , the derivative filter 525 , a resistance block 810 , multipliers 815 - 825 , and an adder 830 together implement the first term
I d_des 3 2 R ( L d R s + 1 )
of the equation 11. Exemplary implementations of the derivative filter 525 are described above by reference to FIGS. 6 a and 6 b . The pole number block 540 , the L q /R block 550 , the R/K e block 515 , and an adder 840 implement the second term
T CMD K e ω e L q
of the equation 11. An adder 835 adds the calculated first term of the equation 11 and the negative of the second term of the equation 11 to output V d 895 .
FIG. 9 is a block diagram that illustrates an implementation of a final voltage command calculation module 900 that computes the final voltage command V mag 945 . The final voltage command calculation module 900 takes as inputs the phase advance angle 599 , V q 595 , and V d 895 . A cosine block 905 and the divider 910 compute the voltage magnitude according to the equation 9 based on the phase advance angle 599 and V q 595 . The hypotenuse block 915 and the sign block 920 compute the voltage magnitude according to the equation 10 based on V q 595 and V d 895 . The selector 935 selects one of the voltage magnitudes computed according to the equations 9 and 10 based on the quadrant in which the motor is operating. That is, the selector 935 selects the voltage magnitude computed according to the equation 9 when the motor is operating in quadrants I or III. Otherwise, the selector 935 selects the voltage magnitude computed according to the equation 10. In one embodiment, the selected voltage magnitude signal may be limited to a range of values by a saturator 940 . In one embodiment, the final voltage magnitude 945 is fed back into the equations 7 and 8 to generate the next final voltage magnitude.
Referring now to FIG. 10 , a flow diagram illustrates a motor control method that can be performed by the control module 30 of FIG. 1 in one embodiment. As can be appreciated in light of the disclosure, the order of operation within the method is not limited to the sequential execution as illustrated in FIG. 10 , but may be performed in one or more varying orders as applicable and in accordance with the present disclosure.
In one example, the method at 1010 receives a torque command indicating a desired amount of torque to be generated by the motor. In one embodiment, the torque command originates from another module (not shown in FIG. 1 ) that monitors the hand wheel movement (e.g., for the hand wheel angle and the hand wheel torque) and computes a desired amount of torque based on the hand wheel movement.
At 1020 , the method obtains a rotational velocity of the motor. In one embodiment, the control module 30 receives an angular position θ of a rotor of the motor 20 of FIG. 1 periodically and computes the rotational velocity based on the received angular positions. At 1030 , the method receives a desired phase advance angle for driving the motor.
At 1040 , the method generates a voltage command indicating a voltage magnitude to be applied to the motor based on the rotational velocity of the motor, the motor torque command, and the desired phase advance angle by using the equations 7-11 that allow the desired phase advance angle to exceed ninety degrees.
A regenerative current limiting function used for deriving the equation 11 will now be described. In various embodiments, when controlling a sinusoidally excited motor, the phase advance angle may be selected based on various design goals. For example, optimal phase advance equations are derived to minimize the peak motor current. To derive the optimal phase advance equations, the steady state motor equations are written, for example, in motor q-axis and d-axis coordinates as follows:
V
q
=
RI
q
+
ω
e
L
d
I
d
3
2
+
K
e
ω
m
Equation
12
V
d
=
-
ω
e
L
q
I
q
+
RI
d
3
2
Equation
13
T
e
=
K
e
I
q
Equation
14
ω
m
=
2
N
p
ω
e
Equation
15
The phase advance angle of the motor voltage command with respect to the motor BEMF waveform is represented by δ and may be calculated with the following equation 16:
δ = Tan - 1 ( - V d V q ) Equation 16
It is to be noted that the d-axis vector is considered positive when the vector is pointing to the right side as shown in FIG. 2 .
In order to minimize the peak current, the d-axis current should be zero whenever possible. For motor voltages below the available supply voltage, the optimal phase advance may be computed by the following equation, which is derived by setting I d =0 in the above equations 12-15 and solving for δ using the equation 16. The result is referred to as optimal phase advance angle δ 2 .
δ
2
=
Tan
-
1
(
ω
e
L
q
T
CMD_SCL
K
e
K
e
ω
e
2
N
p
+
TR
K
e
)
Equation
17
In one embodiment, the magnitude of the value computed for δ 2 is limited by the maximum δ 2 phase advance (δ 2 MAX) equation 18 given below (save the sign of the computed δ 2 and reapply after limiting). This magnitude limiting should be performed because the noise on motor velocity near zero motor velocity could potentially cause the sign of the limit value to be opposite of the sign of δ 2 .
δ
2
MAX
=
Tan
-
1
ω
e
L
q
R
Equation
18
When the supply voltage limit is reached, the I d current is allowed to be nonzero to continue to get the desired torque out of the motor (this is referred to as field weakening). Using phase advance with field weakening allows the torque vs. speed performance of a given motor/control module to be expanded. In order to derive the equation for the optimal phase advance δ 1 at the supply voltage limit, the equations 12-15 above may be solved again with the voltage set constant at the supply voltage (e.g., modulator input voltage, or DC Link Voltage).
X
=
T
cmd
_
SCL
K
e
(
R
2
+
ω
e
2
L
q
L
d
)
+
2
ω
e
K
e
R
N
p
DCLinkLimit
Equation
18
δ
1
=
Tan
-
1
(
X
2
-
R
2
R
ω
e
L
d
+
X
R
2
+
ω
e
2
L
q
L
d
-
X
2
)
Equation
19
The value computed for δ 1 may be limited by the maximum δ 1 phase advance (δ 1 MAX) equation given below:
δ
1
MAX
=
Tan
-
1
ω
e
L
q
R
Equation
20
One or more of the following exceptions to the above calculations of phase advance angle may apply. The first exception is when operating in quadrant III, the minimum, or most negative value, instead of the maximum should be used for the equation 11. When the torque command is zero, the maximum should be used if the motor speed is positive and the minimum should be used if the motor speed is negative. The second exception is that after calculating δ, a limit is applied to the calculated value to ensure δ is within a legal range.
Another embodiment of phase advance calculation is described when used for control of the supply regeneration current. Equation 22 described below for phase advance may be used for quadrants II and IV when the option to limit the amount of supply current regenerated to the vehicle supply is required. This equation allows the amount of supply current regenerated to be calibratable by setting a non-zero desired value of I d current in quadrants II and IV, targeted to provide just enough supply current limiting to meet motor design requirements. An embodiment of this equation for phase advance to be used in quadrants II and IV is as follows:
δ 3 = Tan - 1 ( ω e L q T CMD_SCL K e - RI d_des 3 2 K e ω e 2 N p + TR K e + ω e L d I d_des 3 2 ) Equation 22
The numerator of the input to the arc tangent in the equation 22 is a steady state version of the equation 11.
In an embodiment, the pre-calculated terms from a voltage control sub-function may be used instead of the equation 22, as follows:
Term_D
=
ω
e
L
d
I
d
des
3
2
Term_E
=
RI
d_des
3
2
V
q
=
Term_A
+
Term_B
ss
+
Term_D
Equation
23
V
d
=
-
Term_B
ss
*
Term_X
q
+
Term_E
Equation
24
δ
3
=
Tan
-
1
(
-
V
d
V
q
)
Equation
25
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description.
|
A motor control system comprising a motor configured to operate at a rotational velocity and a control module in communication with the motor is provided. The control module is configured to receive a torque command indicating a desired amount of torque to be generated by the motor, obtain a rotational velocity of the motor, receive a desired phase advance angle for driving the motor; and generate a voltage command indicating a voltage magnitude to be applied to the motor based on the rotational velocity of the motor, the motor torque command, and the desired phase advance angle by using a plurality of dynamic inverse motor model equations that (i) allow the desired phase advance angle to exceed an impedance angle of the motor and (ii) specify that the voltage magnitude is a function of a voltage magnitude of a previous voltage command.
| 7
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Application No. 61/155,122, filed Feb. 24, 2009.
FIELD OF THE INVENTION
[0002] The field of the present invention generally relates to systems and methods for dynamic temperature calibration of a frequency reference. The dynamic temperature calibration is used to correct a frequency drift of an oscillator and to generate timing signals in a wireless base station such as a femtocell base station.
BACKGROUND OF THE INVENTION
[0003] In cellular networks, radio base stations must use a very accurate frequency reference for their RF transmit and receive circuitry and other components. In order to achieve the required degree of accuracy, which is typically on the order of 0.05 parts per million (ppm), this reference may require specialized hardware. Various schemes for generating an accurate frequency reference include synchronizing with an atomic clock, using a frequency derived from a dedicated backhaul connection (e.g., deriving a frequency reference from a T1, E1, or fiber optic cable that uses a Stratum-1 clock as a reference), or using a frequency reference provided by a Global Positioning System (GPS) receiver. These reference schemes are practical in larger base stations where cost sensitivity is low and a fixed line backhaul is standard.
[0004] A new type of base station providing personalized coverage has become attractive to some carriers for subscribers' homes and small offices rather than covering large districts of urban or sub-urban areas. These new base stations are known as femtocells, and are characterized by much smaller coverage areas, consumer-grade packaging and price-points, and the use of consumer internet protocol (IP) connections using various common wireline technologies. These wireline technologies, may include, but are not limited to: DSL, DOCSIS, powerline, and/or coaxial cable. The lack of a fixed line backhaul and extreme cost sensitivity of these femtocells require different synchronization schemes than larger cells use. Additionally, traditional GPS synchronization may not work with femtocells as they are typically installed indoors where a GPS receiver cannot receive a signal from the GPS satellite system that is required to provide the high accuracy frequency reference.
[0005] To meet the price point targets of femtocell base stations, traditional reference schemes cannot be implemented. Accordingly, femtocells may use a less precise oscillator which sacrifices accuracy and precision for cost. These low-cost oscillators encounter frequency drift a result of manufacturing variations or environmental factors such as temperature, humidity, or the age of the oscillator.
[0006] As a reference frequency generated by an oscillator drifts, the base station may begin to transmit outside of an allocated frequency range. This may raise an interference level (e.g., a signal-to-interference-plus-noise (SINR) level) among frequency resources which are shared by adjacent cells (e.g., base stations) in a network, affecting a service provider network's Quality of Service (QOS) as well as network service subscribers' collective Quality of Experience (QOE) within a particular portion of a data communications network. Negative effects associated with poor QOS and poor QOE (e.g., conditions largely caused by congestion and/or interference), which can be exacerbated by adding uncalibrated short-range wireless transceiver devices to a network infrastructure, may include: queuing delay, data loss, as well as blocking of new and existing network connections for certain network subscribers.
[0007] Additionally, it may take more time to arrive at an accurate reference frequency on start-up using a less precise oscillator in a short-range or femtocell base station. Thus, it would be advantageous for any calibration systems and methods to improve a base station's startup procedures in terms of synchronizing with a network frequency.
[0008] Presently, there is a need for improved systems and methods that facilitate reference frequency calibration in a low-cost base station. It would be beneficial if the calibration can be used to improve the accuracy and precision of a low-cost oscillator in order to provide a frequency generation system that is economically feasible in a femtocell base station. It would further be beneficial if the calibration improve a start-up of the base station.
SUMMARY OF THE INVENTION
[0009] This summary is provided to introduce (in a simplified form) a selection of concepts that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
[0010] In overcoming the above disadvantages associated with frequency reference timing systems in short-range base stations, a self-optimizing base station includes systems and methods for dynamic calibration of a frequency reference.
[0011] The present invention may include a transceiver device, comprising: one or more processors; a memory storing a calibration table; a frequency reference; a temperature sensor; and a data communications component, wherein the transceiver device is configured to: receive a reference correction feedback from a network controller device; measure a current operating temperature with the temperature sensor; and update the calibration table using both data related to the reference correction feedback as well as calibration table data associated with the current operating temperature.
[0012] In accordance with another aspect of the present invention, the reference correction feedback relates to an offset measurement determined by taking the difference between a measured frequency derived from the frequency reference and a measured frequency derived from a more accurate frequency reference.
[0013] In accordance with another aspect of the present invention, the process of updating the calibration table further comprises converting the reference correction feedback into a data format consistent with a data format associated with data stored in the calibration table.
[0014] In accordance with another aspect of the present invention, the process of updating the calibration table further comprises reading data from the calibration table associated with the current operating temperature and then combining the read calibration table data with the converted reference correction feedback data.
[0015] In accordance with another aspect of the present invention, the process of updating the calibration table further comprises storing the combined data in the calibration table.
[0016] In accordance with another aspect of the present invention, the frequency reference and the temperature sensor are collocated within the transceiver device, such that the operating temperature of the frequency source is accurately determined by the temperature sensor.
[0017] In accordance with another aspect of the present invention, the updated calibration table is utilized by the transceiver device to correct the frequency reference at a particular operating temperature measured by the temperature sensor.
[0018] The present invention may further include a computer-readable medium encoded with computer-executable instructions for updating a calibration table within a transceiver device, which when executed, performs the method comprising: receiving a reference correction feedback from a network controller device; measuring a current operating temperature of a frequency reference of the transceiver device with a resident temperature sensor; and updating the calibration table using both data related to the reference correction feedback as well as calibration table data associated with the current operating temperature.
[0019] In accordance with another aspect of the present invention, the process of updating the calibration table further comprises: reading data from the calibration table associated with the current operating temperature; combining the read calibration table data with the converted reference correction feedback data; and storing the combined data in the calibration table.
[0020] In accordance with another aspect of the present invention, the process of receiving a reference correction feedback is performed at a predetermined interval throughout an operation of the transceiver device.
[0021] The present invention may further include a computer-implemented method for updating a calibration table within a transceiver device, the method comprising: receiving a reference correction feedback from a network controller device; measuring a current operating temperature of a frequency reference of the transceiver device with a resident temperature sensor; and updating the calibration table using both data related to the reference correction feedback as well as calibration table data associated with the current operating temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Preferred and alternative examples of the present invention are described in detail below by way of example and with reference to the drawings, in which:
[0023] FIG. 1 illustrates a perspective view of a networked computing system in accordance with an embodiment of the present invention;
[0024] FIG. 2 illustrates a block diagram view of a base station in accordance with an embodiment of the present invention;
[0025] FIG. 3 illustrates a block diagram view of a server computer in accordance with an embodiment of the present invention;
[0026] FIG. 4 illustrates a block diagram view of a temperature sensor and a reference oscillator in a base station in accordance with an embodiment of the present invention;
[0027] FIG. 5 illustrates a block diagram of a temperature calibration table and a process of updating the calibration table in accordance with an embodiment of the present invention;
[0028] FIG. 6 illustrates a flow diagram of updating a calibration table to correct a frequency reference in accordance with an embodiment of the present invention;
[0029] FIG. 7 illustrates a flow diagram of updating a calibration table to correct a frequency reference in accordance with an embodiment of the present invention;
[0030] FIG. 8 illustrates a block diagram of a modulation unit for correcting a frequency using input to a voltage controlled oscillator in accordance with an embodiment of the present invention; and
[0031] FIG. 9 illustrates a block diagram of a modulation unit for correcting a frequency using direct digital synthesis in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0032] In accordance with an exemplary embodiment of the present invention, FIG. 1 illustrates a perspective view of a networked computing system 118 in accordance with an embodiment of the present invention. Generally, networked computing system 118 comprises a variety of base station devices (e.g., 102 , 104 , 106 and 108 ), user equipment (e.g., 110 , 112 , and 114 ), and a radio resource manager (RRM) 116 . FIG. 1 illustrates but one example of a network topology, and any number of base stations (which may be referred to generically as “transceiver devices”), user equipment, and RRMs may be used as is known in the Art.
[0033] In accordance with various embodiments of the present invention, base station 102 may be considered to be any of a macrocell, a microcell, or a picocell base station, depending on the reference coverage area provided by the small-area or short-range wireless base station device(s) (e.g., a femtocell or a picocell device) to which the base station coverage area is being compared. Similarly, in accordance with various embodiments of the present invention, a small-area or short-range wireless base station (e.g., 104 , 106 , and 108 ) may be considered to be either a femtocell (e.g., a short-range base station device such as a Home eNodeB) or a picocell device, depending on the reference coverage area provided by neighboring wider coverage area base stations (e.g., macrocell, microcell, or picocell base stations) to which the base station coverage area is being compared.
[0034] In an embodiment, base station devices (e.g., 102 , 104 , 106 , and 108 ) may have overlapping coverage areas depending on the coverage area of the particular base station as well as its proximity to neighboring devices. User equipment (e.g., 110 , 112 , and 114 ) may reside in one or many coverage areas associated with the base stations and may communicate with multiple base stations as shown in FIG. 1 .
[0035] In an embodiment, the base station devices (e.g., 102 , 104 , 106 and 108 ), user equipment (e.g., 110 , 112 , and 114 ), and RRM 116 may be configured to run any well-known operating system, including, but not limited to: Microsoft® Windows®, Mac OS®, Google® Chrome®, Linux®, Unix®, or any well-known mobile operating system, including Symbian®, Palm®, Windows Mobile®, Google® Android®, Mobile Linux®, MXI®, etc. In an embodiment, the base station 102 (e.g., a macrocell base station) may employ any number of common server, desktop, laptop, and personal computing devices.
[0036] In an embodiment, the user equipment (e.g., 110 , 112 , and 114 ) may include any combination of common mobile computing devices (e.g., laptop computers, netbook computers, cellular phones, PDAs, handheld gaming units, electronic book devices, personal music players, MiFi™ devices, video recorders, etc.), having wireless communications capabilities employing any common wireless data commutations technology, including, but not limited to: GSM™, UMTS™, LTE™, LTE Advanced™, Wi-Max™, Wi-F™, etc.
[0037] In an embodiment, the base station devices (e.g., 102 , 104 , 106 and 108 ), user equipment (e.g., 110 , 112 , and 114 ), and RRM 116 may communicate using any data communication network, including but not limited to, a wide area network (WAN) or a local area network (LAN). Either of the LAN or WAN portions of the networked computing system 118 may employ, but is not limited to, any of the following communications technologies: optical fiber, coaxial cable, twisted pair cable, Ethernet cable, and powerline cable, along with any wireless communication technology known in the art. In an embodiment, the base station devices (e.g., 102 , 104 , 106 , and 108 ) may communicate amongst themselves using an X2 interface consistent with a LTE implementation while the base stations may further communicate with the RRM 116 using an S1 connection as defined in the LTE specification.
[0038] In an embodiment, the base station devices (e.g., 102 , 104 , 106 and 108 ), user equipment (e.g., 110 , 112 , and 114 ), and RRM 116 may include any standard computing software and hardware necessary for processing, storing, and communicating data amongst each other within the networked computing system 118 . The computing hardware realized by any of the network computing system 118 devices (e.g., 102 , 104 , 106 , 108 , 110 , 112 , 114 , and 116 ) may include, but is not limited to: one or more processors, volatile and non-volatile memories, user interfaces, transcoders, modems, and wireline and/or wireless communications transceivers, etc.
[0039] Further, any of the networked computing system 118 devices (e.g., 102 , 104 , 106 , 108 , 110 , 112 , 114 , and 116 ) may be configured to include one or more computer-readable media (e.g., any common volatile or non-volatile memory type) encoded with a set of computer readable instructions, which when executed, performs a portion of any of the processes for dynamic temperature calibration of a frequency resource in association with various embodiments of the present invention.
[0040] In one embodiment, base station hardware is dependent on the implementation in the networked computing system 118 . For example, a macrocell base station 102 may include a highly accurate time reference system such as GPS, an atomic clock, or a fixed network connection deriving a frequency reference from a Stratum-1 clock. Alternatively, a femtocell base station (e.g., 104 , 106 , and 108 ) may have a less precise frequency reference such as a voltage controlled oscillator or a fixed frequency oscillator. In one embodiment, a femtocell base station may dynamically calibrate a frequency reference in conjunction with frequency difference feedback from user equipment in accordance with the present invention.
[0041] Further, the radio resource manager (RRM) 116 may coordinate a calibration process in accordance with an embodiment of the invention. In one embodiment, RRM 116 is a separate computer such as a server, while in another embodiment the RRM 116 is incorporated into a base station device (e.g., 102 , 104 , 106 , and 108 ). Further, RRM 116 may employ any number of common server, desktop, laptop, and personal computing devices. RRM 116 is configured to receive and process information from wireless base stations (e.g., 102 , 104 , 106 , and 108 ) through the networked computing system 118 .
[0042] FIG. 2 illustrates a block diagram view of a base station device 200 (e.g., a femtocell or a picocell device) that may be representative of the base stations (e.g., 104 , 106 , and 108 ) in FIG. 1 . In accordance with an embodiment of the present invention, the base station device 200 may include, but is not limited to, a baseband processing circuit including at least one central processing unit (CPU) 202 . In an embodiment, the CPU 202 may include an arithmetic logic unit (ALU, not shown) that performs arithmetic and logical operations and one or more control units (CUs, not shown) that extract instructions and stored content from memory and then executes and/or processes them, calling on the ALU when necessary during program execution. The CPU 202 is responsible for executing all computer programs stored on the base station's 200 volatile (RAM) and nonvolatile (ROM) system memories, 204 and 226 .
[0043] The base station device 200 may also include, but is not limited to, a radio frequency (RF) circuit for transmitting and receiving data to and from the network. The RF circuit may include, but is not limited to, a transmit path including a digital-to-analog converter 210 for converting digital signals from the system bus 220 into analog signals to be transmitted, an upconverter 208 for setting the frequency of the analog signal, and a transmit amplifier 206 for amplifying analog signals to be sent to the antenna 212 . In one embodiment, upconverter 208 may include a modulation unit containing a frequency reference, errors in which may be corrected for based on an ambient operating temperature. Further, the RF circuit may also include, but is not limited to, a receive path including the receive amplifier 214 for amplifying the signals received by the antenna 212 , a downconverter 216 for downconverting the received signals to a baseband frequency, and an analog-to-digital converter 218 for outputting the received signals onto the system bus 220 . The system bus 220 facilitates data communication amongst all the hardware resources of the base station device 200 .
[0044] Further, the base station device 200 may also include, but is not limited to, a user interface 222 ; operations and maintenance interface 224 ; memory 226 storing application and protocol processing software; and a network interface circuit 228 facilitating communication across the LAN and/or WAN portions of the data communications network 118 (i.e., a backhaul network).
[0045] FIG. 3 illustrates a block diagram view of a server computer 300 that may be representative of radio resource manager 116 in FIG. 1 or any other common network device known in the art such as a router, gateway, or switch device. The server computer 300 may include, but is not limited to, one or more processor devices including a central processing unit (CPU) 304 . In an embodiment, the CPU 304 may include an arithmetic logic unit (ALU, not shown) that performs arithmetic and logical operations and one or more control units (CUs, not shown) that extract instructions and stored content from memory and then executes and/or processes them, calling on the ALU when necessary during program execution. The CPU 304 is responsible for executing all computer programs stored on the server computer's 300 volatile (RAM), nonvolatile (ROM), and long-term storage system memories, 302 and 310 .
[0046] The server computer 300 may also include, but is not limited to, an optional user interface 318 that allows a server administrator to interact with the server computer's 300 software and hardware resources; a software/database repository 310 including: frequency and time offset measurements 312 that may include a listing of registered base station devices (e.g., any of 102 , 104 , 106 , 108 , and 200 ) and the type of frequency reference associated with a registered base station device; frequency and time correction unit 316 that analyzes the frequency and time offset measurements 312 and generates frequency correction instructions to a base station (e.g., 104 , 106 , and 108 ); and a performance monitoring display 316 for displaying to administrators at a network operations center, for example, the performance and operation of the networked computing system 118 . Further, the server computer 300 may also include a modem 308 for formatting data communications prior to transfer; a transceiver 306 for transmitting and receiving network communications amongst various network base stations, user equipment, and computing devices utilizing the data communication network of the networked computing system 118 ; and a system bus 320 that facilitates data communications amongst all the hardware resources of the server computer 300 .
[0047] FIG. 4 illustrates a block diagram view of a temperature sensor 402 and a reference oscillator 406 in a base station (e.g., 102 , 104 , 106 , and 108 ) in accordance with an embodiment of the present invention. Temperature sensor 402 may measure an ambient temperature of the base station device or may measure the temperature of the reference oscillator directly. Temperature sensor 402 may employ any common sensing technology including analog temperature sensing, digital sensing, contact/non-contact sensing, etc. In an embodiment, temperature sensor 402 is placed in close proximity to or is collocated with the reference oscillator 406 for accurate readings of the reference oscillator temperature. In operation, the temperature sensor 402 senses the temperature of the reference oscillator 406 and outputs a current temperature 404 , while the reference oscillator 406 outputs a base station reference frequency 408 for use in wireless communications.
[0048] FIG. 5 illustrates a block diagram of a temperature calibration table 514 and a process of updating the calibration table in accordance with an embodiment of the present invention. Temperature calibration table 514 may be stored in a non-volatile memory such as flash or EEPROM, in each femtocell base station (e.g., 104 , 106 , and 108 ). Generally, the calibration table stores a value used in calibrating a reference frequency such as the reference oscillator 406 in FIG. 4 . Additionally, the values in calibration table 514 are used in conjunction with the temperature sensor 502 in calibrating the base station (e.g., 104 , 106 , and 108 ). Thus, the calibration table 514 includes temperature and frequency offset information. When the transmit frequency drifts as the ambient temperature of the base station changes, the frequency correction values stored in the calibration table 514 are used to maintain an accurate transmit frequency by making changes to the reference oscillator frequency as the temperature changes. Further, an accurate transmit frequency is also obtained at power-on of the base station by reading values from the calibration table 514 which may be stored in a non-volatile memory (e.g., memory 204 and 226 of FIG. 2 ). The calibration table 514 may include data in a variety of formats, but is not limited to: a list of frequency correction words with one word for every degree Celsius, degree Fahrenheit, or some other temperature increment; or a set of coefficients for a polynomial from which a frequency correction word can be calculated, when given the temperature.
[0049] In one embodiment of the invention, the contents of the temperature calibration table 514 are initially set to a default set of values, such as all zeros, or some other nominal set of temperature calibration values. This initialization of the temperature calibration table may occur when the base station (e.g., 104 , 106 , and 108 ) is manufactured or at the first time the base station is powered on. In one embodiment, after this initialization the temperature calibration table 514 is not normally reinitialized to its default state, other than through a reset function, typically initiated by a network operator. In another embodiment, the reference correction feedback processes are performed under normal operating conditions and not as a step in a calibration test process.
[0050] The process of updating the calibration table will be described generally by way of examples in FIGS. 5 , 6 and 7 . It should be understood that this process could be executed using one or more computer-executable programs stored on one or more computer-readable media located on any one of the base station devices (e.g., 104 , 106 , and 108 ), or collaboratively on the network base station 102 , or in the radio resource manager 116 in FIG. 1 . In block 506 , a base station device (e.g., 104 , 106 , and 108 ) receives a frequency offset measurement. This frequency offset measurement is a difference between the current transmit frequency of a base station (e.g., reference frequency 408 in base station 104 , 106 , and 108 ) and the transmit frequency of a base station with a high accuracy frequency reference (e.g., a macrocell 102 ). By way of example, the process of generating a frequency offset begins with a subscriber device that is receiving signals from a first base station with a high accuracy frequency reference (e.g. 102 ) and a second base station with a lower accuracy frequency reference (e.g., 104 , 106 , and 108 ). The subscriber device measures a high accuracy transmit frequency signal derived from the high accuracy frequency reference in a downlink communication from the first base station device. Next, the subscriber device measures a transmit frequency of the second base station (e.g., a transmit frequency derived from reference frequency 408 ). The subscriber device may determine the difference between the two transmit frequencies to determine a frequency offset measurement. In another embodiment, the subscriber device may directly or indirectly send the received measurements to a base station or RRM 116 where the base station or RRM 116 determines a frequency offset measurement.
[0051] After a frequency offset is determined, a RRM 116 may determine and send a frequency correction instruction to the second base station with the low-accuracy reference frequency. Alternatively, the second base station may receive only the frequency offset measurement rather than a frequency correction instruction.
[0052] Next, at block 508 the frequency offset measurement is converted to a frequency offset word. This formats the frequency offset measurement data to be used in the base station's calibration process. At an earlier time, concurrently, or after the block 508 has executed, a temperature sensor 502 measures the current operating temperature of the reference oscillator (e.g., 406 ). Thus, the current temperature is read at block 504 . At block 516 , a frequency correction word corresponding to the current temperature is read from the temperature calibration table 514 . Alternatively the frequency correction word may be calculated from the temperature calibration table coefficients in block 516 . Next, at block 510 , the frequency offset word converted in block 508 is added to the frequency correction word extracted from the temperature calibration table in block 516 . The result of block 510 is an updated frequency correction word. This updated frequency correction word is stored in the temperature calibration table in block 512 .
[0053] FIG. 6 illustrates a flow diagram of updating a calibration table to correct a frequency reference in accordance with an embodiment of the present invention. FIG. 6 illustrates a process similar to FIG. 5 but helps illustrate and clarify the timing of the process while highlighting the fact that the order and number of steps may change and still be within the scope of the invention. Again, it should be understood that this process could be executed using one or more computer-executable programs stored on one or more computer-readable media located on any one of the base station devices (e.g., 104 , 106 , and 108 ), or collaboratively on the network base station 102 , or in the radio resource manager 116 in FIG. 1 . At block 602 a base station device (e.g., 104 , 106 , and 108 ) receives a reference correction feedback from a network controller device (e.g., via network interface circuit 228 ). At block 604 , the base station device (e.g., 104 , 106 , and 108 ) measures a current operating temperature of a frequency reference of the base station device with a resident temperature sensor. In one embodiment, the frequency reference is a local oscillator of the base station, such as a voltage controlled oscillator, or a fixed frequency oscillator. In another embodiment, the resident temperature sensor may represent temperature sensor 402 in FIG. 4 .
[0054] At block 606 , the base station device (e.g., 104 , 106 , 108 , and 200 ) updates the calibration table using the data related to the reference feedback (received in block 602 ) as well as the calibration table data associated with the current operating temperature. In one embodiment, this step 606 presupposes that there is calibration table data associated with the current operating temperature, i.e., that this process may have been performed previously and the base station is refining the calibration data. Examples of updating may include, but are not limited to: averaging the received reference correction feedback with the previously stored values; replacing the previously stored values with the current received reference correction feedback; etc. More sophisticated algorithms can also be used to decide when to store the updated reference correction feedback. For example, to protect against large errors in the estimation of the frequency offset by customer premise equipment (CPE) (e.g., a subscriber device or a base station device), an algorithm may detect erroneous values. If a large frequency offset measurement is received in block 602 then the base station may not immediately store the updated reference correction feedback and may rather only adjust the frequency reference (e.g., block 608 ). When the base station receives a subsequent frequency offset measurement that indicates that the frequency offset is indeed smaller, the base station may have more confidence that the latest frequency offset is more accurate for the current operating temperature. When the base station has more confidence that the reference correction feedback in not erroneous, the base station will update the calibration table with the data (e.g., block 606 ).
[0055] Next, at block 608 the base station utilizes the updated calibration table to correct the frequency reference at a particular operating temperature measured by the resident temperature sensor. In one embodiment, the base station will adjust the reference frequency according to the modulation units in either FIG. 8 or FIG. 9 .
[0056] FIG. 7 illustrates a flow diagram of updating a calibration table to correct a frequency reference in accordance with an embodiment of the present invention. Again, it should be understood that this process could be executed using one or more computer-executable programs stored on one or more computer-readable media located on any one of the base station devices (e.g., 104 , 106 , and 108 ), or collaboratively on the network base station 102 , or in the radio resource manager 116 in FIG. 1 . At block 702 a base station device (e.g., 104 , 106 , and 108 ) receives a reference correction feedback from a network controller device (e.g., network interface circuit 228 ). At block 704 , the base station device (e.g., 104 , 106 , and 108 ) measures a current operating temperature of a frequency reference of the base station with a resident temperature sensor. In one embodiment, the operation in blocks 702 and 704 correspond to the operation in blocks 602 and 604 .
[0057] Next, at block 706 the reference correction feedback received in block 702 is converted into a data format consistent with a data format associated with data stored in the calibration table. In once embodiment, the reference correction feedback is converted into a word (e.g., a fixed size group of bits that is processed by the base station device). At block 708 , the base station reads data from the calibration table associated with the current operating temperature and then combines the read calibration table data with the converted reference correction feedback data. Different calculations may take place during step block 708 . In one embodiment, a fraction of the frequency offset word may be added to the frequency correction word in order to reduce the noise on the frequency offset measurement. In another embodiment where the temperature calibration table 514 comprises coefficients used to calculate the frequency correction word, the coefficients can be updated by a least squares method, Chebyshev polynomial approximation, interpolation polynomial, or any other such method as appropriate.
[0058] At block 710 , the base station stores the data combined in block 708 in the calibration table. Finally, at block 712 , the base station utilizes the updated calibration table to correct the frequency reference at a particular operating temperature measured by the resident temperature. This step may include applying a frequency correction to a voltage controlled oscillator in FIG. 8 or may include applying a frequency correction to a direct digital synthesis and interpolation circuit in FIG. 9 .
[0059] FIG. 8 illustrates a block diagram of a modulation unit for correcting a frequency using input to a voltage-controlled oscillator in accordance with an embodiment of the present invention. In one embodiment, the modulation unit may be found in the upconverter 208 of the base station device 200 in FIG. 2 . Generally, the modulation unit may receive transmission data, synchronization data, and frequency correction information as inputs in order to generate a transmit signal as an output. Specifically, the modulation unit receives transmission data as Tx Digital Samples 802 and passes the samples 802 to the Interpolation and Direction Digital Synthesis (DDS) Unit 804 . Along with interpolation, which inserts samples in between two existing samples in a predetermined fashion (e.g., linearly) and at predetermined intervals (e.g., one sample equally spaced between two existing samples), the direct digital synthesis performed by the Interpolation and DDS unit 804 formats and inputs the data into the High Speed Digital-to-Analog Converter (DAC) 806 . The analog signal generated by the High Speed DAC 806 is mixed at the mixer 808 with a carrier frequency generated by Local Oscillator Unit 818 to generate a transmit signal 810 . Thus, components 802 , 804 , and 806 comprise a first operating path in the modulation unit.
[0060] A second operating path in modulation unit begins with a frequency digital input with frequency correction unit 814 . This frequency correction unit 814 may perform a variety of functions, including but not limited to, any of the processes illustrated in FIGS. 5 , 6 and 7 . In one embodiment, the frequency correction unit 814 inputs a frequency correction value stored in the calibration table 514 . Data from the frequency correction unit 814 may pass through digital-to-analog converter (DAC) 812 before being input to a voltage controlled oscillator (VCXO) 816 . In one embodiment, the VCXO 816 may correspond to the reference oscillator 406 of FIG. 4 , while the output of the VCXO 816 may correspond to the base station reference frequency 408 . In this manner the VCXO 816 is algorithmically controlled so that different values applied to the DAC 812 adjust the oscillator frequency of VCXO 816 , which in turn adjusts the carrier frequency generated by the Radio Frequency Local Oscillator Unit with M/N Phase Locked Loop (PLL) 818 . The carrier frequency generated by the second operating path (i.e., with components 814 , 812 , 816 , and 818 ) is mixed with the analog signal generated by the first operating path in the mixer 808 to generate the transmit signal 810 . The transmit signal may be sent to the transmit amplifier 206 and antenna 212 of FIG. 2 for wireless transmission.
[0061] FIG. 9 illustrates a block diagram of a modulation unit for correcting a frequency using direct digital synthesis in accordance with an embodiment of the present invention. In one embodiment, the modulation unit may be found in the upconverter 208 of the base station device 200 in FIG. 2 . Similar to the modulation unit illustrated in FIG. 8 , the modulation in FIG. 9 may receive transmission data, synchronization data, and frequency correction information as inputs in order to generate a transmit signal as an output. FIG. 9 is distinguished from the modulation unit in FIG. 8 because FIG. 9 uses a fixed frequency crystal oscillator rather than a voltage controlled oscillator.
[0062] To generate a local oscillator frequency (e.g., 408 ), the radio frequency local oscillator with M/N phase locked loop 914 is driven by a fixed frequency crystal oscillator 912 . In accordance with an embodiment of the invention, the fixed frequency oscillator 912 may be a lower-cost oscillator, and the oscillator 912 may encounter temperature based frequency variations. To compensate for the drifting local oscillator frequency, which is derived from the fixed frequency oscillator, Tx digital samples 902 representing the data to be modulated and a frequency correction 904 are combined in the interpolation and direct digital synthesis unit 906 to generate a digital waveform. Along with interpolation, which inserts samples in between two existing samples in a predetermined fashion (e.g. linearly) and at predetermined intervals (e.g. one sample equally spaced between two existing samples), the direct digital synthesis performed by the interpolation and DDS subcomponent 906 formats the data in a way that can be fed into the high speed digital-to-analog converter (DAC) 908 . The high speed DAC 908 converts the digital waveform including the frequency correction and the data to be transmitted into an analog waveform to be mixed by the mixer 910 with the signal from the RF local oscillator 914 . The output of the mixer 910 is a transmit signal 916 may be sent to the transmit amplifier 206 and antenna 212 of FIG. 2 for wireless transmission.
[0063] In one embodiment, the transmit signal 916 is a modulated signal with a carrier frequency or center frequency that is either the sum or difference of the RF local oscillator 914 frequency and the center frequency of the analog waveform from the DAC 908 . In the modulation of FIG. 9 , the frequency correction information 904 is input into the interpolation and DDS unit 906 . The frequency correction information 904 is used to determine the frequency of the digital waveform generated by the interpolation and DDS unit 906 . When the frequency-corrected digital waveform is converted by the DAC 908 , the resulting signal from the mixer has been adjusted for any frequency drift caused by temperature variations. In one embodiment, the frequency correction information 904 is based on, but is not limited to: values sent from RRM 116 to a base station (e.g., 104 , 106 , and 108 ); a frequency difference measured by a subscriber device (e.g., 110 , 112 , and 114 ); and/or values stored in the calibration table 514 .
[0064] While several embodiments of the present invention have been illustrated and described herein, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by any disclosed embodiment. Instead, the scope of the invention should be determined from the appended claims that follow.
|
A system and method are described for dynamic temperature calibration of a frequency reference in a wireless base station. In a consumer grade base station, a reference oscillator may encounter frequency drift as the temperature of the base station changes. This causes interference as the transmission signal is not synchronized with other frequency resources in a network. An improved method of calibrating a reference frequency includes measuring a frequency difference between a frequency derived from an accurate reference frequency in a first base station and a frequency derived from a less accurate frequency reference in a second base station, determining a calibration factor for the offset, and applying the calibration factor to the base station to correct frequency drift. The calibration factors may be correlated with an operating temperature of the base station and stored in a temperature calibration table in the base station device.
| 7
|
RELATED APPLICATIONS
This patent application claims the benefit of U.S. provisional application 62/011,006, filed Jun. 11, 2014, the entire content of which is incorporated herein by reference into this application.
TECHNICAL FIELD
The invention relates to a stabilizing and protective device for limbs, especially for legs, by reducing pressure on bony prominences of the heels and ankles.
BACKGROUND
Ulceration of skin on a patient's feet is a common complication of diabetes and peripheral vascular disease. Ulcers can become so serious as to necessitate amputation. Ulcers can occur on any part of the foot, but the bony prominences of the heels and the ankles are especially vulnerable for a bed-ridden patient. The ulcers result in decreased pain sensation which can cause abnormal loading of the feet, increased localized pressure and formation of callouses, which cause tissue damage. The ulcers are primarily treated by ensuring an adequate blood supply; treating the underlying infection with appropriate antibioics; and by relieving the pressure on the affected part.
Pressure ulcers (also known as bed sores) often develop in individuals confined for an extended period to a particular position in a bed or chair. The pressure ulcers can be treated by managing tissue loads, including direct pressure, friction, and shear, through positioning techniques and use of appropriate support surfaces. For example, positioning devices can be used to raise a heel ulcer off the support surface and prevent direct contact between the surface and bony prominences. Past solutions include padding the heel area. But this is often ineffective because the pressure between the padding and the heel may remain significant enough to still cause ulceration, and, moreover, padding will reduce circulation of air about the heel which normally aids in healing of ulcers.
Another conventional means for reducing heel pressure is using a foot and leg protector having a rigid outer shell with an inner soft protective liner. However, the protector includes wrapping or adjusting straps which may cause added pressures on the skin, and reduce blood flow. Additionally, the user has to move, adjust or remove the straps frequently which is inconvenient, uncomfortable and may not be possible for a seriously disabled patient.
Protective devices without straps include a pressure resilient cushion that is adapted to be positioned under a bony prominence (including the knee joint or heel). The pad includes a relatively flat surface conformable to the skin area which it protects. The pad preferably includes a recess to surround the bony prominence, and a section around the recess that abuts, supports and cushions the region around the prominence. However such pads do not maintain the prominence of ankle, heel and elbow at a sufficiently elevated position and, again, significant pressure against the heel may remain when the pad is employed.
Surrounding the limb with a cylindrical padding, or placing a cushion under the calf does elevate the limb. But a cushion does not roll when the patient does so in bed. While cylindrical padding can roll with the patient, it cannot stabilize the limb when the bed surface suddenly deforms (such as by the plaintiff moving his other leg or limbs, or resting an object on or someone suddenly sitting on the bed).
Therefore, there is a need for a device to reduce pressure at the bony prominences of heels, ankles and elbows, which can move with the patient in bed and stabilize the limbs against the bed surface moving.
SUMMARY
A preferred embodiment is a device formed of an elastic foam, preferably latex foam or memory foam. The upper and lower portions are preferably similar to oppositely-facing square pyramids, but having four arced sides rather than flat sides, and where the four sides converge at their apexes (which is positioned furthest from the limb when the limb is inside the channel in place) to form a blunted peak. The device has a longitudinal separation separating the upper portion into two halves. The separation runs along the length of a channel designed to accommodate the patient's limb. The limb is inserted into the channel by first widening the separation and putting the limb in place, then narrowing the opposing halves of the upper portion and closing the two halves about the limb using a strap or fastener system.
To support a user's leg, the channel is of a length so as to surround the region from either above the knee (to protect it) or from just below the knee, to above the ankle. When the patient is lying supine, the bottom portion provides elevation of the ankle and heel from the bed surface. The flexible foam distributes the weight of the leg over the surface of the channel which contacts the underside of the leg. To avoid excessive heat build-up and increase comfort, the tension adjustment is preferably loose enough to provide a gap between the upper surfaces of the user's limb and the adjacent portions of the device.
The arced, square-pyramidal shape of the upper and lower portions (made of an elastic foam), at their respective apexes provides a movement dampening effect, and reduces the responsive movement of the limb even if the mattress upper surface moves vertically quickly. The region of the upper and lower portions near the apexes can compress readily (due to its reduced cross section) and provide such additional movement dampening. When the user lies prone, the upper portion provides the same movement dampening effect, as then the leg weight is resting on the apex in the upper portion. If the user lies on his/her side, the side portions of the foam device provide cushioning and also, facilitates rolling because of its arced shape. It also facilitates having the user roll on his/her side, to where the weight of the limb rests on one of the laterally facing surfaces of the square pyramid, and provides added comfort for the user when lying on his/her side. The shape of the upper and lower portions and the elastic foam material also facilitates movement of the patient longitudinally on the bed. The blunted peak and the two triangle sides provides a “rocking chair” type of assistance to ease out the back and forth movement of the leg. In addition, as the stored energy in the foam from the weight of the user's limb facilitates lifting the weight of the user's limb upwardly, and then the user can inch along the bed surface.
The strap or fastener which closes the channel around the limb is preferably adjustable, and can more preferably be a hook and loop fastener. This adjusting means is adaptable to provide breathability, and help prevent ulcers forming on the bony prominences of limbs, including heels, ankles, knees, and elbows. Finally, this system would allow quick and easy access to any ulcers formed in these areas. As noted, the adjustment should be snug enough such that the device moves with the patient but such that air gaps remain between the limb and the channel.
To accommodate limbs with smaller cross-sections and ensure they fit snugly in the channel, one or more foam inserts, which preferably extend along the channel, can be used. To accommodate abnormally large limbs, including bandaged limbs or swollen limbs, an adjuster can be inserted in the channel to pry it open wider. The upper and/or lower portions of the device are preferably provided with ventilation holes from the outside to the channel, to increase air flow, transfer heat out, and increase patient comfort.
In other embodiments, the device can have the arced square pyramid shape for one portion, preferably the upper portion, and have the bottom portion flattened to distribute the leg weight over a larger surface area. A cylindrical cross section for the device, or an arc cross section for one portion with the other portion flattened or a square pyramid, is also among the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
Elements in the figures have not necessarily been drawn to scale in order to enhance their clarity and improve understanding of these various elements and embodiments of the invention. Furthermore, elements that are known to be common and well understood to those in the industry are not depicted in order to provide a clear view of the various embodiments of the invention. Thus the drawings are generalized in form in the interest of clarity and conciseness.
FIG. 1 is a perspective view of a preferred embodiment of the device, with a user's leg in place;
FIG. 2 is a perspective view of the preferred embodiment of the device from the side, with a user's leg in place;
FIG. 3 is the same view as FIG. 2 , but with the user's other leg positioned on top of the device;
FIG. 4 is an elevational view, showing the user lying on their side.
FIG. 5 is an elevational view from the end of the device, showing the user lying on their side;
FIG. 6 is an elevational view of an embodiment of the device having a cylindrical cross-section;
FIG. 7 is an elevational view from the end of the FIG. 6 embodiment, showing a foam insert for use in the channel of the device;
FIG. 8 is a plan view of the device shown in FIG. 6 .
FIG. 9 is a perspective view of the preferred embodiment held in the open position.
FIG. 10 is a perspective view showing the lower portion of the preferred embodiment.
FIG. 11 is a perspective view showing the upper portion of the preferred embodiment.
FIG. 12 is an elevational view from the front and side of the preferred embodiment.
FIG. 13 is an elevational view from the front and the other side of the preferred embodiment.
FIG. 14 is a cross-sectional view of the preferred embodiment.
FIG. 15 is an elevational view from one side of the preferred embodiment.
FIG. 16 is a plan view from the bottom of the preferred embodiment.
FIG. 17 is a plan view from the top of the preferred embodiment.
FIG. 18 is an elevational view of one type of insert for use in the channel of either embodiment of the device.
FIG. 19 is an elevational view of another type of insert for use in the channel of either embodiment of the device.
FIG. 20 is an elevational view of another type of insert for use in the channel of either embodiment of the device.
DETAILED DESCRIPTION
FIG. 1 depicts a user lying prone and using a first embodiment of a device 100 which, in this position, protects the user's bony prominences at his knees, ankle bones, heels, and toes. FIG. 2 depicts a user with device 100 in place and lying supine, with device 100 protecting the user's bony prominences at his knees, ankle bones, heels and toes. FIG. 3 depicts a user lying supine and resting his unprotected leg on top of device 100 , with device 100 protecting the user's bony prominences at his knees, ankle bones, heels and toes in both legs. FIG. 4 depicts a user lying on his side with a device in place on his leg, with device 100 protecting the user's bony prominences at his knees, ankle bones, heels and toes. FIG. 5 is a plan view of a user lying on their right side, with device 100 protecting the user's bony prominences at his knees, ankle bones, heels and toes. FIG. 6 is an elevational view of another embodiment of the device 70 having a cylindrical cross-section. FIG. 7 is an elevational view from the end of the device 70 , showing a foam insert 75 in place in channel 76 (shown in FIG. 6 ). FIG. 8 is a plan view of device 70 . FIG. 9 is a perspective view of the preferred first embodiment 100 held in the open position about separation 103 . FIG. 10 is a perspective view showing the lower portion 108 of device 100 . FIG. 11 shows the upper portion 109 of the device 100 . In FIGS. 12 and 13 device 100 is inverted and viewed from the side. FIG. 13 is an elevational view from the front and the other side of the preferred embodiment. FIG. 14 is a cross-sectional view of device 100 viewed along channel 102 . FIG. 15 is another side elevational view of device 100 . FIG. 16 is a plan view of the bottom 108 of device 100 . FIG. 17 is a plan view from the upper section 109 of device 100 . FIG. 18 is an elevational view of one type of insert for use in the channel of either embodiment of the device. FIG. 19 is an elevational view of another type of insert for use in the channel of either embodiment of the device. FIG. 20 is an elevational view of yet another type of insert for use in the channel of either embodiment of the device.
With the device 100 in use, the bony prominences of limbs (like, knees, ankle bones, heels, toes, elbows, for arms) are protected from contact with the mattress surface. FIGS. 1-5 show that the ankle bones, heels and toes of the limb in the device 100 , are elevated away from the mattress surface, as are the knees. Alternatively, device 100 can be moved on the leg or lengthened so that the user's knee is also within channel 102 , and thus protected. This position (around the knee), may be especially useful to reduce discomfort in patients having muscle contractions. With an arm in place in the device, and the hand extending out from the end, the bony parts of the hand and wrist as well as the elbow would be lifted out of contact with the surface a user was lying on, and thus protected.
By reducing pressure at bony prominences of limbs, device 100 protects against pressure sores, bed sores (for those confined to bed for long periods) and ulcers. The bony prominences are areas of the body that are at the greatest risk for developing pressure sores and ulcers, which are common complications of diabetes and peripheral vascular disease. Treatment of ulcers requires insuring that there is adequate blood supply, treating the underlying infection with the appropriate antibiotics and relieving the pressure of the affected part. Decreased pain sensation associated with diabetes can lead to abnormal loading of the foot causing increased localized pressure, which results in callouses leading to tissue damage. Device 100 reduces both direct loading forces and shearing forces (when the user moves) over the bony prominences of the limbs.
Device 100 permits the user to lie on their front, side, and back and still protect the bony limb prominences, by either padding them, or elevating them from the bed surface.
In use, the user can lie prone, supine or on their side (as shown in FIGS. 1-5 .) When the user lies on their side, the arced surfaces of the upper portion 109 or the lower portion 108 , can lie on a flat surface, like a mattress-top, and increase user comfort. FIG. 3 shows that when lying supine, the user's comfort can be enhanced by placing the other leg on top of the device 100 .
FIGS. 6-8 show another embodiment of device, which is device 70 , having a cylindrical cross-section. Device 70 accommodates a user's leg in its channel 76 , and following insertion of the limb, the split 50 is closed with hook and loop fastener 30 . Device 70 can be used with a cylindrical insert 75 ( FIG. 7 ) to accommodate thin limbs, including arms, and provide a better fit.
In FIGS. 9-17 , the preferred embodiment of device 100 has separation 103 between the two halves of the upper portion 109 , and channel 102 designed to accommodate a patient's limb. The two portions of a hook and loop fastener, 20 and 21 , are affixed to either side of the separation 103 , are not in the closed position (attached to each other). Separator 18 maintains the separation of the two halves of the upper portion 109 against the elasticity of the foam device 100 (which tends to draw the two halves of upper portion 109 together). Ventilation holes 11 in the upper portion 109 run from the outside of device 100 and to the channel 102 —to dissipate heat from the patient's limb and provide greater comfort.
The lower portion 108 (shown in FIG. 10 ) is designed to rest on a support surface e.g., a bed, sofa, mat, or any other generally horizontal surface capable of supporting the user's limb. The opening of separation 103 can be adjusted with the adjuster 18 ( FIG. 9 ) to increase the size of the separation 103 so as to more readily admit and accommodate larger limbs. Since some users have bandaging and/or edema (swelling), the elasticity of device 100 allows accommodation of such limbs in channel 102 . The device 100 is preferably adjusted after the limb is inserted to provide breathability to as much of the limb inside the device as possible, i.e., an air gap between the skin surface and the inside of the channel 102 is preferred.
Device 100 includes two oppositely-facing arced square pyramidal portions, upper portion 109 and lower portion 108 , with a limb-accommodating channel 102 between the two portions and accessible by opening the upper portion 109 along separation 103 . After the limb is in place, the separation 103 is closed by joining together the two parts 20 and 21 of the hook and loop fastener.
The devices of the invention may have their respective channels 102 or 76 fitted with a natural fabric liner (eg., cotton) liner, adding to the overall comfort and reducing the chance of an allergic reaction to the foam in these devices. The channels or other portions of these devices may also be treated with anti-fungal and/or anti-bacterial agents to preserve hygiene and reduce infection risk.
Among the advantages of the preferred embodiment 100 is that the patient's leg can readily move laterally or longitudinally along the bed, due to the reduced area (of either the upper 109 or lower portion 108 , depending on whether the user is supine or prone) in contact with the bed, and because of the elasticity of the foam it's formed from (which absorbs energy to facilitate the patient's relieving the weight on the limb before moving it). This ease of movement aids comfort and health by encouraging shifting of the leg position, and thereby promoting circulation. With the user placing their other leg (with or without a device on that other leg) on top of the upper portion 109 , as in FIG. 3 , the design aids circulation and comfort for both legs.
Although Velcro™ fasteners having sections 20 , 21 are preferred, a number of other means, such as straps or cords with buckles, clips or Velcro fasteners, or clips, buckles, elastic bands, ropes, strings, bungee cords, or other means can be used to draw the two halves of the upper portion 109 of the device around the user's limb. Any wrapping around the device should be used with caution, as it may cause added pressure on the limb and restrict blood flow.
In an exemplary embodiment, the length of channel 102 may be approximately 10.5-11.5 inches, while the diameter of channel 102 is approximately 5-6 inches.
FIGS. 18-20 each show a different type of insert which can be placed into channel 102 in order to accommodate smaller limbs more snugly, or, to elevate the user's foot or knee further from the surface the user rests on. The insert(s) selected would be inserted through the separation 103 , either before or after the limb was in place. The device would then be closed about the limb. Optionally, the inserts can be fastened in place with cords or fasteners (including Velcro™).
In a first embodiment, there is a foam limb-support device for reducing pressure on heels and feet and other bony prominences for a user, comprising: an upper portion and a lower portion which are each shaped as oppositely-facing square pyramids having four converging arced sides; a channel extending through the device between the upper portion and the lower portion; and wherein, at least one of the upper portion and lower portion includes a separation running the length of the channel and dividing at least one said portion into two parts, such that when the two parts are separated, a user's limb can pass between the two parts and into the channel; and a means for fastening said two parts together, once the user's Limb is in place in the channel.
The means for fastening can be a hook and loop fastener, a strap, a cord, an elastic band, a bungee cord, a rope, a clip, a buckle or a re-useable adhesive. The device can be made of latex foam or memory foam. The device can include one or more ventilation holes extending from inside the channel to the outside of the device. The device can include an adjuster which can expand the channel. The adjuster can be made out of foam. The convergence of the triangular sides preferably forms a blunt ridge rather than a sharp peak. The four arced sides of the device are positioned such that a portion of one of the sides is on the upper surface of the bed when the user lies on his side. The device can include one or more inserts which can be positioned in the channel to more snugly accommodate a limb in the channel. The channel can be sized such that a substantial gap remains between the limb in the device and the adjacent inner surface of channel. The device can further include a natural fabric liner on the inner surface of the channel. The inner surface of the channel can be coated with anti-fungal and/or anti-bacterial agents.
In a second embodiment, there is a foam limb-support device for reducing pressure on heels and feet for a user, comprising: a substantially rectangular section made of an elastic foam designed to surround the user's limb; a means for fastening two edges of the rectangular section together. Once the user's limb is in place atop the rectangular section, a channel is formed surrounding the user's limb. The channel is sized such that a substantial gap remains between the limb and the adjacent inner surface of channel. The device can include a foam insert which is positioned immediately adjacent the user's limb when the limb is in place in the device. The device can be made of latex foam or memory foam. The device can further include one or more ventilation holes extending through the section. The means for fastening can be a hook and loop fastener, a strap, a cord, an elastic band, a bungee cord, a rope, a clip, a buckle or a re-useable adhesive. The device can further include a natural fabric liner (like cotton) on the surface of the section adjacent the user's limb. The surface of the section adjacent the limb is coated with anti-fungal and/or anti-bacterial agents.
While this invention has been disclosed with reference to specific embodiments, it is apparent that other embodiments and variations of this invention may be devised by others skilled in the art without departing from the true spirit and scope of the invention. The appended claims are intended to be construed to include all such embodiments and equivalent variations. Although described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without departure from the spirit and scope of the invention as defined in the appended claims.
|
A pressure reducing device for reducing pressure at bony prominences of limbs is disclosed. A preferred embodiment is formed of an elastic foam, having upper and lower portions similar to oppositely-facing square pyramids, but having four arced sides rather than flat sides, and where the four sides converge at their apexes to form a blunted peak. The cushion body is shaped and sized so as to reduce the loading and shearing forces over the bony prominences of limbs, thereby reducing pressure and to readily allow a user to move along the support surface and to change orientations (roll or lie on their side).
| 0
|
CROSS REFERENCE TO RELATED APPLICATIONS
Pursuant to 35 U.S.C. §§ 119(e) and 120, this application is a continuation-in-part application of U.S. application Ser. No. 09/685,499, filed Oct. 10, 2000, now U.S. Pat. No. 6,802,826 which claims priority to Russian Application No. 99121141, filed Oct. 12, 1999 and Russian Application No. 99124268, filed Nov. 23, 1999, and this application claims priority to prior U.S. provisional application No. 60/329,081, filed Oct. 12, 2001, the disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a protector cap with an auto-disable feature for needle-free drug delivery devices for animal and human health applications.
BACKGROUND OF THE INVENTION
The most effective measure to prevent many diseases among animals and/or humans is the mass immunization with vaccines. Needle-free injectors have been used to accomplish this task. The traditional needle-free injectors comprise the basic design, a housing with an inner power unit, a medication unit, and a nozzle. The power unit pumps the medication into an under-plunger cavity of the medication unit chamber and expels the medication through the nozzle.
With the use of a typical jet injector, there exists the possibility of infection transfer from one subject to another by means of fluids (blood, lymph, medication) reflected from the skin surface during injection (“back splash”) that may get on the nozzle and be transferred from one patient to the next. Further, in the injection stage, the contaminated matter can be transferred through the nozzle to inside the injector such as, for example, into the cavity and be transmitted to a new patient through a new cap and nozzle.
Accordingly, there is a need in the art of needle-free injection devices to solve the problem of cross-contamination during mass vaccinations. More particularly, there is a need for a protector designed for the nozzle head of needle-free injectors, which halts “back splash” contamination, and which is low enough in cost to ensure its practical application as a disposable unit even for mass vaccinations.
SUMMARY OF THE INVENTION
The preceding problems are solved and a technical advance is achieved by the present invention. Disclosed is a protector cap for a needle-free injector having an insert and a baffle integrally joined and a disable device located between the insert and the baffle.
The protective cap may be a one-shot cap. One purpose of this device is to prevent the multiple use of a cap. This may be achieved through the removal, replacement, and/or destruction of the cap at the later stage of the injection.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1A demonstrates an exploded view of a simple embodiment of the present invention.
FIG. 1B demonstrates the simple embodiment in assembled form.
FIG. 2 shows an exploded view of another embodiment of the present invention in which another component is introduced.
FIG. 3 shows an exploded view of another embodiment of the present invention in which some components are modified.
FIG. 4 shows other embodiments of the present invention in which a protective layer is shown at various positions.
FIG. 5 shows yet another embodiment of the present invention in which an intermediate piece is shown.
FIG. 6 shows yet another embodiment of the present invention in which a protective layer is shown at various positions.
FIGS. 7A–D depict several different embodiments of the protective layer of the present invention.
FIG. 8 is one embodiment of the protector cap of the present invention.
FIG. 9 is another embodiment of the protector cap of the present invention.
FIGS. 10A–C depict the operation sequence of the protector cap and injector during an injection.
FIG. 11 shows an adhesive strip covering the cradle of a package for storing protector caps.
FIG. 12 is a sectional view of FIG. 11 along section line 12 — 12 showing a package for storing protector caps of the present invention and a protector cap.
DETAILED DESCRIPTION
FIG. 1A demonstrates an exploded view of the present invention. An injector assembly 10 is shown. One purpose of the injector assembly 10 is to provide needless injection of medicaments into the skin 12 . As described herein, the injector assembly 10 is provided with a layer, such as protective layer 14 . The protective layer 14 generally comprises a material that is adapted to permit the injection of medicaments in one direction, yet minimize or retard the reverse flow. The source of the medicament jet stream is from an injector 18 . In this regard, the protective layer 14 can serve as a back splash guard. In this particular, exemplary, and non-limiting embodiment, an optional baffle 16 is provided to facilitate the diminution of back splash.
The baffle 16 may further comprises a baffle orifice 20 , which can take any desired shape or size, depending on the intended use. In this regard, the length and cross-section of the baffle orifice 20 will influence how much back splash hits the protective layer 14 . It is contemplated in all embodiments that the size of the baffle orifice 20 can be sized to minimize disruption of the medicament jet stream yet maximize the protection afforded by the protective layer 14 . If the baffle orifice 20 is too small, the baffle 16 may disrupt the jet stream and thereby reduce the energy of the stream. If too much diminution of the stream energy occurs, then the jet stream will not penetrate the skin 12 in the desired fashion to the desired depth.
Baffle 16 can be sized to accommodate the needed configuration, and may optionally include baffle wings 15 to ensure proper skin stand-off. Of course the length and diameters may vary significantly, but in one example, baffle 16 can be approximately greater than 11 mm in diameter and 5 mm tall. Generally, the diameter of the baffle orifice 20 should be slightly larger than the diameter of the jet stream. Therefore, it does not really matter how large the baffle orifice 20 is so long as it is slightly larger than the jet stream diameter, irrespective of the diameter of the injector orifice 22 .
Injector 18 has an injector orifice 22 at the distal end of an injector canal 24 . The medication sought to be injected travels through the injector canal 24 , exits through the injector orifice 22 and punctures the protective layer 14 . The medication jet stream then enters the baffle orifice 20 and impacts the skin 12 . The energy of the jet stream is chosen to provide the desired injection, depth, and location. For example, for a deeper injection, a higher energy will be necessary. The medicament jet stream then enters the skin 12 and travels to the desired situs. However, the impact on skin 12 is not without some attendant consequences. One consequence is that surface tissue, fluids, cells, and cellular contents are removed or ablated from the surface of skin 12 and fly about. This back splash of debris can travel back along the jet stream and impact the baffle 16 and protective layer 14 . The debris, though, is generally not traveling fast enough to re-puncture the protective layer 14 . In this regard, the protective layer 14 retards or minimizes the debris back splash into the injector orifice 22 and the injector 18 . One function of the layer 14 is to prevent the contamination of the injector 18 . In this regard, the simple concept of the invention is to protect the injector orifice 22 from contamination. Thus, in the event no baffle 16 is used, the injector 18 itself may bear the protective layer 14 .
The material chosen for the layer 14 may comprise any material that facilitates a fluid stream puncture in one direction, yet retard the fluid stream puncture in the opposite direction. For example, the layer 14 can comprise a biochemically inert material that is approved for contact with pharmaceuticals, such as but not limited to, at least one of a plastic, rubber, polymer, polyethylene, polytetrafloroethylene, polyurethane, polypropylene, polyolefin, and polysulfone material. In this regard, a material that permits the perforation by the jet stream in one direction but then seals upon itself after the jet stream stops is more desirable. The protective layer or layers are desirably thin, for example greater than 0.001 mm. Preferably and nonexclusively, the thickness can range in the about 0.004 to 0.08 mm range with a further thickness of about 0.2 to 0.5 mm. It should be noted that the thickness chosen is variable. Protective layer 14 may also be textured, woven, braided, or so configured to provide a better adhesion, if necessary, or to provide better attachment, or to prevent or minimize movement. For example, the layer 14 may have grooves of various types. As mentioned, the diameter of the protective layer 14 (if a disc, or the width if a strip) should be slightly larger than the diameter of the jet stream.
As shown in FIG. 1A , the components are in exploded view. In assembly, the baffle 16 can be designed to fit within the injector 18 and sandwich the layer 14 generally between the baffle 16 and injector 18 . Desirably, the injector orifice 22 and baffle orifice 20 should line up to minimize any diminution of the stream energy. As with any connection and assembly herein, the baffle 16 can be adapted to provide a friction fit, snap fit, screw fit, or bayonet fit. Any component herein can also be heatsealed to fit.
Protective layer 14 can be also adhered, bonded, or otherwise attached to the injector 18 , baffle 16 or to any part as desired.
FIG. 1B demonstrates a simple embodiment of the present invention. As one can see, the protective layer 14 can be generally sandwiched between baffle 16 and the injector 18 . The protective layer 14 can be totally sandwiched or partially sandwiched between the components described herein. As the medication is injected out through injector canal 24 and injector orifice 22 , it will penetrate through the layer 14 and through the baffle orifice 20 .
It should be noted that in any embodiment of the present invention, the medication need not be liquid. In addition to aqueous solutions, the present invention may employ suspensions, aqueous gels, emulsions, or controlled release injectable medications. One other dosage form includes powder. For example, Powderject Pharmaceuticals, of Oxford, United Kingdom, and/or Powderject Vaccines (Madison, Wisc.) have developed an injector that propels medicine in powder form in the same manner as traditional needle-free injectors. For example, see, U.S. Pat. Nos. 5,733,600; 6,053,889; and 5,899,880; the disclosures of which are expressly and entirely incorporated herein. Since the powder form of drugs take up less than 1% of the volume of drugs in liquid form, adapting the powder injectors to be used in accordance with the present invention is also contemplated.
Generally, but not exclusively, the powder particles of one dose can range in size but are generally 50 microns wide, as compared to a 500 micron wide syringe needle. In other words, powder form vaccines, such as recombinant DNA based vaccines, including Hepatitis B and HIV vaccines, and other medications for treating influenza, tetanus, erectile dysfunction, allergies, pain, cancer, etc., are contemplated. Such powder forms may be admixed with small amounts of sterile water or other physiologically acceptable diluents (e.g., about 1–10%) to form pastes or suspensions. Therefore, adapting the powder injectors to have a protective cap and/or film consistent with the present invention is within the ordinary skill in the art.
FIG. 2 demonstrates another embodiment of the present invention. The injector assembly 10 is shown having a baffle 16 and an insert 26 . The insert 26 can be adapted to form an insert reservoir 27 . Insert 26 also has an insert distal orifice 28 . Insert 26 can be adapted to fit with baffle 16 such that the insert 26 provides an additional benefit of back splash protection, during or after the injection is completed. Insert 26 can be adapted to fit with baffle 16 such that insert 26 helps to properly tension the skin for the injection type (intramuscular, subcutaneous, or intradermal). As shown in this particular, exemplary, and non-limiting embodiment, the protective layer 14 is generally located between, either partially or completely, the baffle 16 and the injector orifice 22 . In this configuration, the jet stream will exit the injector orifice 22 , penetrate through the layer 14 , and exit through the baffle orifice 20 and insert distal orifice 28 to impact the skin 12 . The skin debris will back splash against the insert 26 and any debris that flies into the insert distal orifice 28 will likely be stopped by the baffle 16 . In the event that debris trajectory permits debris to travel through the baffle orifice 20 , the debris will impact the distal surface 29 of layer 14 .
In this regard, the injector orifice 22 is protected against contamination. The debris that hits the protective layer distal surface 29 will likely fall into the insert reservoir 27 and collect there. Insert 26 can be adapted to fit into the baffle 16 as needed. One benefit of the insert configuration is the disposability of the unit. As for configuration, the injector orifice 22 can be varying distances away from the skin 12 . For example, it can be adjacent the skin 12 (where a baffle or insert is not used and the layer 14 is attached directly to the injector 18 ), or millimetres away, such as 2–15 mm away. Naturally the distance chosen will reflect on the stream energy. Desirably, the injector orifice 22 distance from the skin 12 is chosen with this in mind. In some configurations, the proximal face of the baffle 16 could be millimetres away from the skin, such as 2–15 mm and desirably 2–7 mm. Insert orifice 28 diameter is also sized accordingly, such as 0.001 mm or greater. In one commercial embodiment, however, the insert 26 , baffle 16 , and protective layer 14 can be discarded as a unit upon contamination.
FIG. 3 represents another embodiment of the present invention. Shown are the baffle 16 , insert 26 , protective layer 14 , and injector 18 . In this configuration the baffle 16 is adapted to provide a greater surface area exposed to potential back splash. The insert 26 is also adapted to minimize back splash contamination. For example, insert 26 has an insert inner surface 30 and an insert outer surface 32 . As shown in dotted lines, the insert 26 can be configured to form “wings” in which the insert 26 will cooperate with the baffle 16 . Baffle 16 has a baffle inner surface 34 that cooperates with the insert 26 . As shown in this embodiment, the insert outer surface 32 is in cooperation with the baffle inner surface 34 . The wings of the insert 26 come into proximity of each other to form an insert proximal orifice 36 . In this embodiment, any back splash of skin debris entering the insert distal orifice 28 will likely hit the insert inner surface 30 , or the baffle inner surface 34 , or the distal surface 29 of protective layer 14 . In the event insert 26 is configured to not have wings, any debris can still hit the insert inner surface 30 , the baffle inner surface 34 , or the distal surface 29 of protective layer 14 .
FIG. 4 demonstrates yet another embodiment of the invention. Shown is a plurality of protective layers 14 shown in phantom 38 . In this exemplary and non-limiting embodiment, the protective layer 14 is shown covering the baffle orifice 20 . The protective layer 14 can be integrally formed with the baffle 16 or can be separately affixed to the baffle 16 . In this embodiment, the removal of the baffle 16 facilitates disposability.
Also shown is that multiple protective layers 14 are present. Protective layers 14 can be generally found proximal the skin, coincident with the insert distal orifice 28 , proximal to the insert distal orifice 28 , distal to the baffle 16 , distal to the baffle orifice 20 , coincident with the baffle orifice 20 , or proximal to the baffle orifice 20 . The number of protective layers can be chosen to maximize the jet stream energy for puncture purposes, but diminish back splash contamination potential. Also shown in FIG. 4 is the assembly in which the insert 26 and baffle 16 are within the injector assembly 18 . Where multiple layers are used, the layers can be attached using bonding, heatsealing, or sandwiching the layers.
As seen in FIGS. 7A–D , it should be noted that in any embodiment herein, the protective layer 14 or film need not be a separate piece. Rather it may be integrally formed with a component, such as a septum. For example, the protective layer 14 may be part of the baffle 16 in which that area that will be punctured by the jet stream is adapted to give way during injection. For example, if the baffle 16 is made of plastic, then the area that will serve as the protective layer can be integral with the baffle 16 yet be “ground” down slightly to make it thinner or more easily adapted to perforation. In yet another embodiment, the layer 14 may be separately manufactured then adhered in some fashion to a component, such as the baffle 16 . In yet another embodiment as shown in FIG. 7D , a plurality of films may also be used (as shown in phantom lines).
FIG. 5 demonstrates yet another embodiment of the present invention. Baffle 16 is provided with a plurality of baffle legs 40 . The baffle legs 40 can be adapted to cooperate with an intermediate piece 42 . The intermediate piece 42 has a proximal and distal end such that various components can be attached to either or both ends. In this particular, exemplary, and non-limiting embodiment, intermediate piece 42 has an intermediate piece orifice 44 therethrough. This intermediate piece orifice 44 can be formed by one or more intermediate piece extensions 46 . As with any orifice described herein, the size and shape of the orifice 44 may determine the potential back splash contamination and the interruption of the jet stream energy. Intermediate piece 42 can be connected to injector 18 and/or baffle 16 and/or insert 26 via an intermediate piece connector 48 . The intermediate piece connector 48 can include any mechanism to attach one piece to another, and can further include a friction fit, bayonet, or screw fitting.
Therefore, as medication is extracted from the medication vial 50 , it is drawn into the injector chamber 52 wherein the injection system 10 then delivers the medication through the injector canal 24 , through the injector orifice 22 , into the intermediate piece 42 , through the intermediate piece orifice 44 , and then through the various distal components.
As shown in FIG. 5 , upon exiting the intermediate piece orifice 44 , the medication will penetrate the protective layer 14 and then enter the baffle 16 via the baffle orifice 20 , then through the insert reservoir 27 , through the insert distal orifice 28 , to then impact the skin 12 .
Skin debris, if it has the correct trajectory, can enter the insert 26 -baffle 16 component. Debris can either strike the baffle 16 , such as baffle splash guards 54 , or insert 26 itself, or can strike the protective layer distal surface 29 . In the event that the debris has sufficient energy to re-puncture the layer 14 , debris will then strike the intermediate piece 42 , such as the intermediate piece extensions 46 . In this manner, the only manner in which the injector tip is contaminated is if the debris enters the intermediate piece 42 at such a precise trajectory that is flies through the orifice 44 and directly hits the injector orifice 22 .
However, although not shown in FIG. 5 , a plurality of protective layers 14 can be used at various stages along the insert 26 , baffle 26 , or intermediate piece 42 . Intermediate piece 42 can also include an optional intermediate piece channel 56 , which fluidly communicates with the atmosphere and the intermediate piece lumen 57 . This permits an equalization of pressure in the lumen 57 and also permits any debris in the lumen 57 to be evacuated. As for size, intermediate piece channel 56 can be approximately any size but may be about 1 mm.
Therefore, the injector assembly 10 provides increased resistance to contamination using a variety of components. It is noted that in any and all embodiments described herein, no individual component is critical or necessary for accomplishing the invention.
For example, the embodiment of FIG. 5 can be configured so that it does not have an insert 26 , a baffle 16 , a protective layer 16 , or the intermediate piece 46 . In FIG. 5 , the addition of the insert 26 and baffle 16 provide added benefit.
FIG. 6 demonstrates yet another embodiment of the present invention. In this embodiment, an insert 26 plays many roles. First, the insert 26 is provided with an insert connector 60 , shown here by example only, as a screw fitting. The intermediate piece 42 is provided with an intermediate piece distal connector 62 , as shown by example only, as a screw fitting. Accordingly, the intermediate piece distal connector 62 cooperates with the insert connector 60 to provide a detachable attachment. The, insert 26 is adapted to provide the same characteristics as the baffle 16 (not shown) in that it can be adapted to also have an insert splash guard 64 . While the protective layer 14 is shown proximal to the insert 26 , the intermediate piece 42 can also include an intermediate piece protective layer 66 located anywhere along the intermediate piece 42 . This intermediate piece protective layer 66 is shown in phantom either distal to the intermediate piece orifice 44 , coincident with the orifice 44 , or proximal to the orifice 44 . In this regard, the intermediate piece protective layer 66 is distal to the injector orifice 22 . In operation, the debris that enters the insert 26 will likely impact the insert splash guard(s) 64 , the protective layer 14 , the intermediate piece extension(s) 46 , or the intermediate piece protective layer 66 . In this regard, the disposability of the components is enhanced in that the intermediate piece inner surface 68 remains generally clean in that most debris stays within the insert 26 or strikes the protective layers 14 , 66 .
FIG. 8 depicts another embodiment of the present invention. The baffle 16 and the insert 26 may be heat-sealed or otherwise bonded to form an integral protector cap 100 with an insert reservoir 27 . The baffle 16 may be a flat sheet or may have a dome shape, as depicted in FIG. 8 to facilitate intra-dermal injections, for example. In one embodiment, the baffle 16 and the insert 26 cannot be taken apart or modified without destroying the protector cap 100 . The baffle 16 includes a flange 80 to which the insert 26 is bonded. In one embodiment, the baffle 16 may include ribs 81 on the flange 80 to stiffen the cap structure and ensure proper placement of the baffle layer against the skin and prevent slippage. The protective cap 100 may further include a disable device. In one embodiment, the disable device is a central washer 82 located between the baffle 16 and the insert 26 in the insert reservoir 27 . The central washer 82 may also include a washer orifice 84 that lines up with the baffle orifice 20 and the insert orifice 28 when the central washer 82 is in an installed position. For use during an injection, the central washer 82 must be located in the installed position. Thus, the protector cap 100 creates four challenges for blood or debris to enter the injector canal 24 : the insert orifice 28 , the washer orifice 84 , the baffle orifice 20 , and the injector orifice 22 .
Upon injection, the baffle 16 of the protector cap 100 becomes distorted due to the pressure created by the subject's skin 12 or by an injector component, as described below. The baffle 16 may also become distorted during packaging and shipping if not handled carefully. When the baffle 16 becomes distorted, the central washer 82 dislodges in the insert reservoir 27 . As a result, the washer orifice 84 no longer lines up with the baffle orifice 20 and the insert orifice 28 , thereby disabling the protector cap 100 for further use. As a result, entry of the debris or blood into the injector canal 24 is even more difficult because the orifices 28 , 84 , 20 and 22 are no longer aligned. In one embodiment, the central washer 82 is tinted to a different color than the insert 26 or baffle 16 so that the user can determine whether the central washer 82 is in the installed or disabled position.
In another embodiment of the protector cap 100 depicted in FIG. 9 , the shape of the baffle 16 may be modified to ease the disabling of the protector cap 100 . The insert 26 may include a hinge 88 having a lug 90 for holding the central washer 82 in the installed position. The hinge 88 produces a double hinge line that allows the baffle 16 to deflect as shown in the operation sequence of FIG. 10A–C . The hinge 88 provides for programmed deflection of the baffle 16 to ensure that the central washer 82 is dislodged before the cap 100 is ejected from the injector 18 . Upon application of pressure, the baffle 16 distorts and pops the central washer 82 from its installed position on the lug 90 ( FIG. 10A ) to a dislodged position ( FIG. 10B ). In one embodiment, a bead 92 has been added near the flange 80 of the baffle 16 . The bead 92 locks into a grove or other locking feature of a cap receiver 110 on the injector 18 .
In the operation sequence of FIG. 10 , pressure from the cap receiver 110 of the injector 18 distorts the baffle 16 rather than pressure from placement against the skin 12 . A sliding sleeve 112 in the cap receiver 110 contacts the hinge 88 of the baffle 16 , causing the hinge line of the hinge 88 to flex and knocking the central washer 82 out of its installed position. Once the central washer 82 is loose in the insert reservoir 27 of the protector cap 100 , the protector cap 100 is disabled and will not allow a stream from the injector 18 to penetrate. After being disabled, the sliding sleeve 112 continues to move forward towards subject and pops the protector cap 100 free of the cap receiver 110 . In one embodiment, the injector 18 cannot be fired unless the protector cap 100 is in the cap receiver 110 .
The protector cap 100 may further include a protective layer 14 , as described above. The protective layer 14 may cover the insert orifice 28 , the washer orifice 84 , the baffle orifice 20 , or the injector orifice 22 or may be suspended within the insert reservoir 27 . In another embodiment, the protector cap 100 may further include an upper washer 86 that holds the protective layer in place when the protective layer is made from a material that can not adhere to the material of the baffle 16 .
Protector caps 100 may be packaged individually or in packets. In one embodiment, protector caps 100 are packaged as part of a kit. The protector caps 100 may be packaged in individual or numerous rows. A cradle with a separate well for each protector cap 100 may be sealed with an adhesive strip to provide a contamination free environment.
FIG. 11 shows a package 200 for storing a plurality of protector caps 100 . The package 200 has a cradle 210 having at least one row of separated wells 220 for storing one or more protector caps 100 . The package 200 further includes an adhesive strip 230 covering the cradle 210 to preserve the hygienic nature of the protector caps 100 located in the wells 220 of the cradle 210 and to secure the protector caps 100 during shipping and transport. FIG. 12 is a sectional view of FIG. 11 taken along section line 12 — 12 shown in FIG. 11 . FIG. 12 shows a protector cap 100 located in a well 220 of the cradle 210 of the package 200 . Similar to the protector cap 100 illustrated in FIGS. 8 , 9 , bA, lOB and bC, the protector cap 100 shown in FIG. 12 has a baffle 16 which has a baffle orifice 20 , a washer orifice 84 and an insert orifice 28 through which a medicament stream passes m order to accomplish a needle-free injection. Additionally, as previously explained, the presence of the baffle orifice 20 , washer orifice 84 and an insert orifice 28 make it significantly more difficult for any resulting backsplash of biological debris from contaminating the injector. The protector cap 100 illustrated in FIG. 12 also has a central washer 82 with the washer orifice 84 passing therethrough. The central washer 82 is located in the insert reservoir 27 which is fonned by joining the insert 26 with the baffle 16 as previously described. FIG. 12 also shows a protector cap 100 located in a cradle 210 , the adhesive strip 230 and the well 220 for storing the protector caps 100 .
Although the present invention is described by reference to a single and exemplary embodiments, and the best mode contemplated for carrying out the present invention has been shown and described, it is to be understood that modifications or variations in the structure and arrangements of these embodiments other than those specifically set forth may be achieved by those skilled in the art and that such modifications are to be considered as being within the overall scope of the present invention. It is to be further understood that the following pending patent applications owned by the assignee of the instant application are hereby incorporated by reference in their entirety as if fully set forth herein: U.S. Ser. No. 09/685,499; PCT/US00/41122; U.S. Ser. No. 09/685,633; PCT/US00/27991; U.S. Ser. No. 09/717,548; PCT/US00/32186; U.S. Ser. No. 09/717,559; PCT/US00/32187; U.S. patent application Ser. No. 10/269,570 for “Jet Injector System with Hand Piece” filed on Oct. 11, 2002.
|
Disclosed is a medical device used to prevent the cross-contamination of patients or injectors in which various components placed on the injector minimize or eliminate back splash contamination of the injector.
| 0
|
This application is a division of application No. 129,543 filed Mar. 12, 1980 now U.S. Pat. No. 4,371,987.
BACKGROUND OF THE INVENTION
Surgical or medical gloves are manufactured by dipping hand-shaped glove forms into a liquid bath containing an elastomeric material such as a rubber latex or a vinyl plastisol. The forms are withdrawn from the bath, and a coating or film of the elastomeric material is retained on the form. The elastomeric material is allowed to cure, usually with the application of heat, and the gloves are subsequently stripped from the forms for packaging and distribution.
The glove forms are made in the shape of a hand and are mounted on racks. The racks containing the forms are conveyed through various stations to apply the elastomeric material to the form to wash the coated forms to remove undesirable ingredients from the elastomer on the forms and to an oven where the elastomer is cured.
Some surgical or medical gloves are manufactured with a rolled cuff or circumferential bead around the cuff to aid in donning the glove and in preventing the glove from rolling down the wrist when in use. Other surgical and medical gloves are manufactured with a patterned wrist or cuff which inhibits cuff roll-down, which has been recognized as a problem with beaded cuffs. The pattern of the wrist portion of such gloves is usually made by providing the desired pattern on the glove forms used in making the gloves. The forms employed to make the patterned cuff are considerably more expensive than a smooth glove form. The patterned gloves are also difficult to strip from the form because of adhesion of the glove film to the form in the interstices in the pattern on the form. Patterned gloves of this type are disclosed in U.S. Pat. Nos. 2,821,718 and 4,095,293. The previously available ring rolling mechanisms were complex mechanisms which moved around the glove form in making the ring rolled cuff, or in which the glove form was rotated around the ring rolling mechanism. U.S. Pat. No. 2,482,418 discloses a ring rolling mechanism of the latter type. Because of the relative motion of the ring rolling mechanism and the forms, the individual glove forms were separated from each other on the rack by a considerable distance to allow the ring rolling mechanism to move around the form.
The separation of the forms on the rack to allow for the ring rolling mechanism reduced the number of glove forms that could be mounted on a rack. Since the glove making process is essentially a batch process, the overall production rate of the process is limited by the number of glove forms that can be mounted on a rack.
SUMMARY OF THE INVENTION
The present invention provides an improved apparatus of forming a ring rolled cuff on a surgical or medical glove. The present application allows glove forms to be mounted closer together on a rack, which results in greater production rates from a glove making production line. The present invention provides a ring rolling apparatus having multiple rollers or wheels each of which contacts a limited area on the free wrist end portion of the elastomeric film on the glove form and rolls that portion onto itself to form a number of densely rolled segments in the bead on the cuff end of the glove. The continuity of the elastomeric film allows those portions of the film of the cuff end of the glove, which is not in contact with the rollers, to be gathered into loosely rolled segments in the bead. The resulting glove has a rolled ring or bead which is composed of a number of individual tightly or densely rolled segments separated by a number of individual loosely rolled segments. The glove formed in this manner has a greater resistance to roll down in use than a glove with a uniformly rolled bead.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified side view of the present apparatus showing the ring rolling apparatus and the relative location of the glove forms in phantom.
FIG. 2 is a view taken along lines 2--2 of FIG. 1, again showing the glove form in phantom.
FIG. 3 is a view taken along lines 3--3 of FIG. 1 showing the location of the camming mechanism to move the ring rollers to a ready position.
FIG. 4 is a view of one of the ring rollers moving on its support arm to its operative position.
FIGS. 5-7 are schematic views showing the operating positions of the ring rollers in relation to the glove forms.
FIG. 8 is a detailed view, partly in section, of one of the ring rollers.
FIG. 9 is a top view of the ring roll formed on the glove with the relative position of the rollers shown in phantom.
FIG. 10 is a side view of the ring roll on the glove.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is employed in a standard glove manufacturing process. The process that will hereinafter be described is that process employed in the manufacture of gloves from natural or synthetic rubber latex. It will be understood by those skilled in the art that if a different film forming elastomer is employed, certain of the process steps may be modified or eliminated entirely.
A number of glove forms are fixed to a rack which carries the forms through the various steps or stages of the process. The individual glove forms have the configuration of a hand and are made of aluminum, porcelain or other suitable material. The glove forms are either right or left handed. The rack is transferred from the various stations or stages in the process by a conveyor.
The glove forms may be coated with a release agent to allow for the easy removal of the completely finished glove. The forms are then dipped or sprayed with a coagulant for the rubber latex. The forms are then dipped into a tank of the latex with the finger portion of the forms pointed down, and the latex coagulates on the form. The forms are removed from the tank producing an uncured latex film on the form. The forms may be dipped into the same latex tank or into other latex tanks to build up the desired thickness of latex film on the form. The rack carrying the forms is then dipped into a washing solution which removes undesirable ingredients from the latex film. The forms are then conveyed to a station where the ring roll or bead is produced on the wrist portion of the form. The forms are then conveyed to an oven where the latex is cured by the application of heat. The completed gloves are then stripped from the forms and reversed so that the latex film in contact with the form becomes the outer surface of the finished glove. The glove may also be stamped with a symbol to indicate the size of the glove and may be dusted with a lubricating powder to aid in donning the glove.
Referring to the drawings, a number of individual glove forms 11 are shown supported on a rack 12. The rack 12 is supported in the proper position in relation to the ring rolling mechanism by rails 31 attached to an upper frame 30. Individual glove forms are attached to the rack by a suitable fastener. The ring rolling mechanism is supported on a base 13. The base 13 and the rack 12 are mounted so that they may be moved in a vertical direction relative to each other. This is most easily accomplished by mounting the base 13 on a support so that the base 13 and the ring rolling mechanism can be moved downwardly while the rack 12 remains in a fixed position.
The following description refers to the one side of FIG. 1. It is to be understood that the apparatus of the other side of FIG. 1 is a mirror image of the side shown.
There is a drive shaft 14 mounted in bearing blocks 15 which in turn are mounted on the base 13. The shaft is rotated by a drive means 27. Attached to the shaft 14, through free-turning bearings, are a series of roller arms 16. Each of the arms 16 is independently mounted on the shaft 14 through the free turning bearings. The independent mounting of the arms allows each arm to move the required distance to allow the surface of each wheel to achieve maximum surface contact with a particular form even if the particular form is misaligned on the rack. At the upper end of each roller arm 16 a roller 17 is attached through a free-turning bearing. The roller is in the shape of a truncated cone with a drive ring 18 below the base of the cone. A drive belt 19 is affixed around the drive ring 18 and a drive sheave 20 which is keyed onto shaft 14. The drive belt 19 may be a circular belt, as shown in the drawings, or may be a V-belt or a tooth rubber belt. The rotation of the shaft 14 will turn the rollers 17 through the drive belt 19.
Each individual roller 17 is made of a polyurethane polymer which provide a surface which will engage the latex film to produce the ring roll. The polyurethane wheel must have adequate hardness for durability in use but be sufficiently soft to grip the latex film. A Shore A Durometer hardness of about 55 is preferred. The face of the roller which contacts the form should be cut to present the maximum surface area to the form. When using four rollers per form, as shown in the drawings, the face of the roller is cut at an angle of 45 degrees. Although it is possible to use more or less than four rollers, it has been found that four rollers give good controllability of the ring rolling process while allowing for the maximum number of forms on a rack.
There are a series of cams 21 mounted on a fixed shaft 22. There is one cam 21 for each pair of roller arms 16 on each side of the unit. The cams 21 can be moved through a cam shaft actuator arm 23 by the action of cam actuating cylinder 24 which is mounted on the base 13 with an appropriate bracket 25. The cam actuating cylinder may be powered by air or hydraulic fluid. The purpose of the cam system is to move the roller arms 16 away from the glove forms 11 after the ring rolling operation has been completed. This is accomplished by the piston 26 of the cam actuating cylinder pushing the cam 21 against the roller arm 16. This causes the lower portion of the roller arm to rotate around the shaft 14 and move the upper portion of the roller arm carrying the roller 17 away from the form 11.
The operation of the ring rolling apparatus will best be understood with particular reference to FIGS. 5-7.
The rack 12 contains a number of glove forms 11 aligned in a row. The forms have previously been dipped in latex, and the latex-bearing forms have been washed to remove undesirable ingredients before the rack 12 reaches the ring rolling station. Each form is covered with an uncured latex film 32 in the shape of the form. When the rack reaches the ring rolling station, it actuates a switch, not shown, which starts the ring rolling process. The position of the rack 12, relative to the ring rolling device, is shown in FIG. 2 at the start of the process. The process starts with the rotation of the shaft 14 which turns the drive sheaves 20 which are keyed into the shaft 14. The drive belts 19 on the drive sheaves transmit power to the rollers 17 in the direction of the arrows. The cam 21 has been removed from contact with the arms 16, thus, allowing the arms 16 to freely pivot about the shaft 14. The rotation of the rollers 17 in the direction of the arrows causes the roller arms 16 to rotate around shaft 14 and bring the rollers 17 into contact with the form 11, as shown in FIG. 6. The rollers 17 first contact the forms 11 at a point on the forms which is above the latex dip level shown at 29 in FIG. 5. At the same time, the base 13 begins to move downwardly to move the rollers 17 down the form from the latex dip level 29 toward the fingers of the glove, as shown in FIG. 7. When the rollers have moved down the form the required distance to produce the ring roll, the cam actuating cylinders 24 are activated by appropriate switches to move the cam actuator arms 23 and the cams 21 into contact with the lower portion of the arms 16. The cams 21 move the lower portion of the arms 16 toward the center line of the apparatus causing the upper portion of the arms to rotate around the shaft and carry the rollers 17 away from the form 11.
The rollers 17 form the ring roll on the glove by rolling the latex film on the form onto itself. As the free edge of the glove at the dip line 29 is rolled, the relative vertical movement of the glove form 11 and the rollers 17 causes the ring first formed to enlarge as more of the film is rolled. The size of the ring roll can be controlled by adjusting the total vertical movement of the form.
The ring roll or bead formed on the cuff of the glove has the configuration shown in FIGS. 9 and 10 of the drawings. In that portion of the ring roll that has been directly contacted by the rollers 17, the ring is tightly rolled as shown at 27. The portions of the ring roll between the tightly rolled portions are comparatively loosely rolled as shown at 28. FIG. 9 shows the relative position of the rollers 17 in relation to the tightly or densely rolled segments 27 and the loosely rolled segments of the ring rolled cuff.
When the glove is worn by a surgeon, there is a noticeable reduced tendency for the glove to roll down the surgeon's wrist. It is believed that the pillow-like loosely rolled portions 28 of the ring roll create a greater surface area in contact with the cuff on the surgeon's gown. It appears that more force is required to roll down the cuff of the glove, much as an underinflated automobile tire requires more force to roll than a properly inflated tire.
|
An elastomeric surgical glove with an improved ring rolled cuff and a method and apparatus to produce the cuff is disclosed. The ring rolled cuff comprises alternating tightly rolled segments with loosely rolled segments. The ring rolled cuff is made by contacting the uncured glove on the glove form with a plurality of rotating wheels while the wheels are moved on the form from the wrist end of the form toward the hand end of the form. The portions of the cuff in contact with the wheels are tightly rolled, and the remaining portions are loosely rolled.
| 0
|
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates generally to the polishing of glasses, semiconductors, and integrated circuits. More particularly, this invention relates to the surface preparation of articles wherein a more rapid rate of polishing is desired.
Description of the Prior Art
Polishing solutions, or slurries generally consist of a solution which contains a concentration of abrasive particles. The part, or substrate, is bathed or rinsed in the slurry in conjunction with an elastomeric pad which is pressed against the substrate and rotated such that the slurry particles are pressed against the substrate under load. The lateral motion of the pad causes the slurry particles to move across the substrate surface, resulting in wear, volumetric removal of the substrate surface.
The rate of surface removal (polishing rate) is largely determined by the magnitude of the applied pressure, the velocity of pad rotation and the chemical activity of the abrasive particle. While virtually any particle of sufficiently small size may be used for polishing, economically useful high polishing rates are exhibited by a relatively small number of compounds. For most substrates (e.g., SiO 2 or silicates) the highest rates are found for formulations composed primarily of CeO 2 or ZrO 2 . In consequence, there is a large body of prior art describing the composition and preparation of polishing slurries based on these two oxides.
Extensive efforts have been made to develop additives which accelerate the rate of polishing in order to make the polishing process more economical. Such accelerants may be generally classified as etchants, which would by themselves dissolve the substrate, or polishing compound accelerants, which increase rates when added to the abrasive itself. Etchant accelerants, such as described in U.S. Pat. No. 4,169,337 are commonly employed in conjunction with SiO 2 abrasives to polish silicon wafers. These additives can be classified into two categories; (1) additives that increase or buffer the solution pH (e.g. organic amines), or (2) organic compounds, generally amines, that may additionally increase the Si corrosion rate by complexing or sequestering Si (e.g., ethylene diamine or piperazine). These classes of etchant accelerants are distinctly different than the accelerants employed in the present invention.
A variety of polishing compound accelerants have been described. They can be classified into two main categories; (1) Additives which are coprecipitated with the base abrasive prior to calcination, and (2) water soluble additives to the final polishing slurry. Examples of prior art belonging to the first category are found in U.S. Pat. No. 3,262,766 (Nonamaker), U.S. Pat. No. 3,768,989 (Goetzinger and Silvernail) and U.S. Pat. No. 3,301,646 (Smoot). These examples am important, as they illustrate the primary prior art pathways for coprecipitating activating substances.
Nonamaker teaches the incorporation of small amounts of SiO 2 (<5 % ) to a mixture consisting primarily of rare earth oxides (including CeO 2 ) prior to calcination in order to accelerate polishing rates in the final calcined product. The precise mechanism of this effect is not understood.
In a similar fashion, Goetzinger and Silvernail taught coprecipitation of rare earth carbonates, primarily cerium carbonate, together with Wollastonite (calcium metasilicate). The co-precipitate was subsequently calcined to yield an activated final product. Once again, the precise mechanism of the activation was not disclosed.
Smoot taught the deliberate incorporation of Calcium or other divalent ions (e.g., Mg 2 +) into zirconium oxide to produce calcium-stabilized cubic zirconium oxide, a material which is widely used as a structural ceramic. The process consisted of dry batch mixing of ZrO 2 and the stabilizing compound, typically CaCO 3 , followed by calcination of the mixture at elevated temperature (.sup.˜ 2100° F.) to form a cubic ZrO 2 product. The stabilized cubic zirconia was found to have an accelerated polishing rate relative to the normal monoclinic phase of zirconia obtained without addition of the calcium accelerant.
The second pathway for activation is the activation of slurries by addition of water soluble additives to the final solution. As reviewed by Silvernail ("Mechanism of Glass Polishing", Glass Industry, vol. 52, pp. 172-5, 1971), addition of Ce(OH) 4 to polishing slurries can produce significantly increased polishing rates. In particular, some previously inactive oxides, such as Tb 4 O 7 showed high polishing rates after Ce(OH) 4 addition. Other compounds have also been used as accelerants. Shlishevskii and Migus'kina (Sov. J. Opt. Technol., vol. 44, pp. 680-1, 1977) demonstrated as much as 2X inprovement in polishing rate when 2% ammonium molybdate, 1% Mohr's salt (NH 4 )SO 4 FeSO 4 , or 1% zinc sulphate was added to a CeO 2 -based polishing slurry. The basis of the effect was ascribed to complexation of silicate reaction products with the additive compounds so as to prevent their redeposition back onto the substrate surface.
The prior art methods for enhancing polishing activity suffer from a number of deficiencies. First, while etchant additives may increase the overall rate of surface removal of the substrate, their action is isotropic, i.e., they attack all portions of the exposed substrate surface regardless of position. This leads to significantly degraded surface roughness and texture in the polished substrate. Their incorporation is therefore generally considered to be undesirable for slurries used to prepare high quality surfaces (i.e. final polishing). This is particularly true for the polishing of Si wafers.
As regards polishing compound additives, the principal deficiency of adding additives prior to calcination is that rates cannot be adjusted subsequent to formation of the final polishing compound. An additional deficiency is that the technique cannot readily be applied to some polishing abrasives of technical importance, particularly SiO 2 , which is commonly used for Si wafer and integrated circuit polishing. Solution additives, such as Ce(OH) 4 , have not given consistent activation and cannot be used with SiO 2 -based polishing slurries due to gelation.
Yet another obvious way of increasing the polishing rate of a slurry with low rate (e.g. SiO 2 ) would be to simply add to it a portion of another slurry (e.g., CeO 2 ). While this has not been the subject of prior art disclosures, it is a common practice in the polishing art. This technique suffers from two deficiencies. First, the rate of increase is linearly proportional to the amount of the second slurry added. Thus, to achieve a substantial amount of acceleration, a significant fraction of the second material must be added. Second and more critical, addition of the second slurry changes the particle size distribution of the original slurry unless the two particle size distributions are precisely matched. While this may be possible, it is generally not economically feasible. This is particularly true in the case of colloidal silica slurries such as are used in Si wafer polishing. These slurries have extremely small particle sizes, typically 50-100 nm. In contrast, all known commercial CeO 2 -based slurries have mean particle diameters in excess of 1000 nm. Incorporation of such larger particles would have a catastrophic effect on the quality of the Si wafer surfaces produced after polishing. From the above, it is clear that an additive which could increase polishing rams without increasing the static corrosion of the substrate, which could be applied to a variety of abrasive types, particularly SiO 2 , subsequent to particle formation, and which could be applied without alteration of the original slurry particle size would be a significant improvement over prior art.
Accordingly, it is the object of this invention to provide an improved means of increasing the polishing rate of slurries without increasing the overall corrosiveness of the polishing solution, which can be easily applied to a variety of abrasive particles, particularly SiO 2 , and which can be employed in a manner which does not alter the original particle size.
It is also an object of this invention to provide polishing slurries with significantly improved performance which are prepared by said means.
These and other objects of the invention will become apparent to those skilled in the art alter referring to the following description and examples.
SUMMARY OF THE INVENTION
The object of this invention has been achieved by providing a process for preparing compositions suitable for polishing surfaces, particularly integrated circuits, wherein the base abrasive, e.g., SiO 2 , is activated by addition of a second cation, whose oxide exhibits a higher polishing rate than the base abrasive alone. The activation is effected by chemical adsorption of the activating cation onto the base abrasive. This adsorption is accomplished by co-milling the base abrasive and small amounts of an activating oxide in an aqueous medium whose pH is at a level which is favorable for adsorption of the activating cation onto the base abrasive surface. Alternatively, one may employ milling abrasives which themselves are made from or contain said activating cation under the same solution conditions to obtain the same result.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a property of a composition of this invention as compared to an untreated composition.
DESCRIPTION OF THE INVENTION
This method of preparation differs substantially from prior art activation processes in that it is applicable to a variety of base abrasive particles, providing that certain minimum conditions for adsorption are met, no subsequent thermal processing of the abrasive is required, and, when the milling abrasives are used as the source of the activating cation, no foreign particles are added to the slurry which might negatively change the particle size distribution. Additionally, as will be shown in subsequent examples, only small quantities of activating cations are required for a substantial acceleration of polishing rate. This makes the technique of the present invention clearly different from the case of a simple addition of a second more active abrasive component.
The basis for the effect is transfer of active cations to the surface of the base abrasive by cyclic impact with a solid source of said active cation. As a consequence of this adsorption, the abrasive particle takes on the surface characteristics of the activating ion itself. Thus a SiO 2 particle treated with a ZrO 2 source will exhibit surface charge characteristics similar to that of a ZrO 2 particle. During polishing, the particle will, therefore, exhibit rates characteristic of a ZrO 2 abrasive rather than a SiO 2 abrasive.
While there is extensive prior art technology existing for changing surface charge of solid or particulate surfaces by adsorption of a second cation (e.g. Al 3+ on SiO 2 , see R. Iler, The Chemistry of Silica, Wiley-Interscience, NYC, 1979, pp. 667-76) it has been exclusively effected by adsorption from solution. In sharp contrast, the proposed mechanism for the present invention is that interparticle bonds are momentarily formed and broken during the impact process, resulting in retention of a surface concentration of activating cations on the base particle surface.
When said cyclic impacts are performed under solution conditions favorable to adsorption of the activating cation of interest onto the base abrasive surface, retention of the activating ion may be enhanced. The recognition of the importance of controlling the solution pH to stabilize retention of activating cations onto the base abrasive is a key factor in the success of the present invention. For each combination of activating cation and base abrasive there will be a specific pH range which is optimal. This may be relatively narrow or quite broad. For cations of practical interest, particularly Zr 4+ , strong adsorption onto silica surfaces occurs over virtually the entire pH range, and precise control of pH during the milling process is of secondary importance. These cations are preferred, as it allows broader latitude in the manufacturing of activated silica polishing slurries.
Examples of polishing slurries prepared by the present invention are set forth below to illustrate the essential features and results. They are not meant to be restrictive in any way.
EXAMPLES
Example 1
A polishing slurry (composition 1.a) was prepared as follows. 30 kg of fumed silica was added to 70 kg. deionized water and blended using a high speed mixer until throughly dispersed. The mixture was then fed through an agitator mill which contained a zirconium silicate mill medium. The silica mixture was milled at a flow rate of 1.5 liter/min and passed to a second tank. After milling, sufficient water was added to dilute the milled product to 13% solids concentration, and ammonium hydroxide was added to adjust the final pH to 10.5. Chemical analysis of composition 1.a showed a ZrO 2 content of 1.4 ppm in the final composition. Measurements of the surface potential (zeta potential) were made using acoustophoresis to assess the surface charge of the milled particles relative to a high purity silica sol (2355) and a high purity ZrO 2 sol. As shown in FIG. 1; the zeta potential for composition 1.a was markedly different from that of a high purity silica sol (2355). The isoelectric pH, or pH at which the zeta potential was zero, was shifted markedly to higher pH (from 2.2 to 4). This value is intermediate between the silica and zirconia reference samples.
An equavalent slurry (composition 1.b) was prepared in the same manner but without milling. Chemical analysis of composition 1.b indicated no ZrO 2 present, confirming that the ZrO 2 observed in composition 1.a had originated from the zirconium silicate mill media.
Both compositions were then used to polish samples of thermally grown SiO 2 on Si substrates using a Strasbaugh model 6DS planarizer to assess polishing activity. Polishing conditions were 7 psi downforce, 20 rpm table speed, and 150 ml/min. slurry flow, and an IC1000 polishing pad, with dressing between sample runs. Composition 1.a gave a polishing ram of 1200 angstroms/min. In contrast, composition 1.b polished at only 600 angstroms/min, a two-fold difference.
Example 2
Four lots of slurry (hereinafter designated as compositions 2.a-2.d) were prepared in the same manner as composition 1.a of the previous example. Composition 2.a was identical to composition 1.a in every respect. Compositions 2.b, 2.c, and 2.d were made with 1%. 2 %, and 4 % CeO 2 substitutions for SiO 2 respectively. The CeO 2 was added to the initial dispersion prior to milling.
Following slurry preparation, all compositions, as well as a portion of a commercially available silica based polishing compound (SC-112, manufactured by Cabot Corp.), were used to polish samples of thermally grown SiO 2 on Si substrates using a Strasbaugh model 6CA polishing machine for assessment of polishing activity. Polishing conditions were 7 psi downforce, 20 rpm table speed, and 150 ml/min. slurry flow, and an IC1000 polishing pad. No pad conditioning was employed. Average polishing rates are summarized below.
TABLE 1______________________________________Sample Polishing rate (angstroms/min)______________________________________SC-112 901Composition 2.a 1184Composition 2.b 1106Composition 2.c 1658Composition 2.d 1665______________________________________
Composition 2.a gave a polishing rate equivalent to 1.a, as expected. A significant amount of additional activation was observed with CeO 2 additions. However, the activation was clearly non-linear; a threshold concentration of .sup.˜ 2 % CeO 2 gave the most pronounced effect. Additional CeO 2 addition did not give further increase in rate (2.c vs. 2.d). This threshold activation effect is quite different from the linear effect expected from simple addition of CeO 2 to the slurry. Also, as was the case example 1, the quantity of CeO 2 required for activation is substantially below levels normally used to obtain rate enhancement in simply blending two slurries.
|
Disclosed is a process for preparing activated compositions and the compositions derived therefrom which are suitable for polishing surfaces, particularly integrated circuits, wherein a base abrasive is activated by addition of a second cation whose oxide exhibits a higher polishing rate than the base abrasive alone. The activation is effected by chemical adsorption of the activating cation onto the base abrasive during cyclic impact in an aqueous medium whose pH is at a level which is favorable for adsorption of the activating cation onto the base abrasive surface.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable
BACKGROUND OF THE INVENTION
Arterial blockages, which are also called stenosis, lesions, stenotic lesions, etc, are typically caused by the build-up of atherosclerotic plaque on the inside wall of an artery. In fact, several such stenoses may occur contiguously within a single artery. This can result in a partial, or even complete, blockage of the artery. As a result of the danger associated with such a blockage, several methods and procedures have been developed to treat stenoses. One such method is an angioplasty procedure which uses an inflatable balloon to dilate the blocked artery. A typical inflatable angioplasty device, for example, is disclosed in U.S. Pat. No. 4,896,669.
Angioplasty balloons have enjoyed widespread acceptance in the treatment of stenoses. Recent studies, however, have indicated that the efficacy of the dilation of a stenosis is enhanced by first, or simultaneously, incising the material that is creating the stenosis. Consequently, recent developments have been made to equip angioplasty balloons with cutting edges, or atherotomes, which are intended to incise a stenosis during the dilation procedure. For example, U.S. Pat. Nos. 5,196,024; 5,616,149 and 5,797,935, the entire contents of each of which are incorporated herein by reference, respectively describe an inflatable angioplasty balloon having a number of atherotomes mounted longitudinally on the surface of the balloon. Upon inflation of the balloon, the atherotomes induce a series of longitudinal cuts into the surface of the stenotic material as the balloon expands to dilate the stenosis. As a result of such cuts, the stenosis is more easily dilated, and the likelihood of damaging the artery during dilation is reduced.
Blades in many existing cutting balloon assemblies tend to be fairly rigid, particularly in the axial direction. The rigid axial structure of the blade naturally limits the blades ability to elongate with the underlying balloon material during balloon expansion at high pressure. As a result, stress between the comparatively axially rigid blade and the elongating balloon may lead to stress therebetween. This stress can lead to de-lamination of the blade and/or adhesive from the balloon. The effect of balloon elongation is more pronounced in larger diameter balloons than in smaller diameter balloons, and is further amplified in longer balloon lengths as well. As such, it has been necessary, particularly in larger vessel applications, to limit the materials of blade equipped balloons to those that are fairly stiff such as PET, PEN, etc. in order to minimize axial elongation.
Existing blades also tend to be fairly rigid in the transverse direction as well. This has the affect of limiting the flexibility of the balloon as it is advanced through the tortuous confines of a vessel or other body lumen.
In light of the above it would be desirable to provide a cutting blade for use with a cutting balloon that is more flexible, and which does not interfere with or is compatible with the expansion characteristics of the balloon to which it may be mounted.
All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to several embodiments. In at least one embodiment the invention is directed to a medical balloon for use with a catheter or similar device, wherein the medical balloon is equipped with at least one cutting blade.
In some embodiments one or more portions of the cutting blade or blades define a serpentine path or shape relative to the surface of the balloon upon which the blade is mounted. A serpentine path extends radially outward from the balloon surface and then back toward the balloon surface in a repeating pattern.
In at least one embodiment the serpentine path is provided by a plurality of adjacent undulations. In at least one embodiment adjacent undulations define a substantially S-shaped segment of the blade.
In at least one embodiment the blade has multiple serpentine regions, each of which define a separate serpentine path. Each serpentine region is separated by a region of the blade which is not serpentine. The non-serpentine regions may be characterized as being linear, and while such regions may define a path having one or more bends or curves to accommodate the shape of the balloon (e.g. the transition form the balloon waist to the balloon cone, the transition from the balloon cone to the balloon body, etc.) such regions do not define a serpentine path.
In some embodiments the blade employs separate serpentine regions each of which extend along the surface of a balloon cone, and a serpentine region which extends along the surface of at least a portion of the balloon body. Such cone serpentine regions of the blades and the body serpentine regions of the blade may have similar or different serpentine shapes or pathways. For example, in at least one embodiment, the cone serpentine regions define a path having a shallower height and/or a longer wavelength than the body serpentine region.
The blade may be constructed of any material suitable for forming a cutting blade. The body region of the blade defines at least one cutting surface or edge. Regions of the blade adjacent to the body region need not include a cutting surface. As such, in at least one embodiment different regions of the blade define one or more different cross-sectional shapes. In at least one embodiment the body region of the blade defines a substantially triangular shaped cross-section. In at least one embodiment regions of the blade adjacent the body region have rectangular (ribbon), round, ovoid, square or other cross-sectional shape(s).
In at least one embodiment one or more portions of the blade in close proximity to the balloon surface are engaged to the balloon surface by an adhesive or other mounting material. The adhesive may be any adhesive material suitable for securing a metal, polymer or carbon based blade to the material of the balloon.
In at least one embodiment portions of the blade engaged to the balloon are defined by the “troughs” of the serpentine path of the body region of the blade. Adjacent “peaks” are then free to flex, bend, or otherwise alter their position as the balloon is expanded, bent or otherwise altered in shape or configuration. This substantial freedom of movement of the peak portions of the body region allow the blade to remain in contact with the balloon regardless of the balloon's longitudinal expansion or axially transverse bending. In some embodiments the proximal and distal end regions of the blade, which respectively extend over the proximal and distal waists of the balloon are likewise engaged to the balloon and/or adjacent catheter shaft with an adhesive or mounting material. In some embodiments the blade ends are encased in adhesive or mounting material to prevent contact of the blade ends with the lumen wall through which the catheter is advanced.
As indicated above, a balloon may be equipped with any number of blades as desired. In at least one embodiment for example, the balloon is provided with a single blade, while in other embodiments 2-20 blades may be mounted onto the balloon. Multiple blades may be uniformly or irregularly spaced apart, and may have similar or different shapes, lengths, serpentine paths, etc.
These and other embodiments which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof However, for further understanding of the invention, its advantages and objectives obtained by its use, reference should be made to the drawings which form a further part hereof and the accompanying descriptive matter, in which there is illustrated and described a embodiments of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
A detailed description of the invention is hereafter described with specific reference being made to the drawings.
FIG. 1 is a side view of an embodiment of the invention wherein a balloon is shown with a single serpentine blade.
FIG. 2 is a cross-sectional view of the embodiment depicted in FIG. 1 .
FIG. 3 is a side view of the embodiment shown in FIG. 1 wherein the balloon includes 2 serpentine blades.
FIG. 4 is a cross-sectional view of the balloon shown in FIG. 3
FIG. 5 is a side view of the embodiment shown in FIG. 1 wherein the balloon includes 4 serpentine blades.
FIG. 6 is a cross-sectional view of the balloon shown in FIG. 5
FIG. 7 is a detailed side view of a serpentine blade such as is shown in FIGS. 1-6 .
FIGS. 8-12 are each cross-sectional views of respective portions of the blade shown in FIG. 7 .
FIG. 13 is a side view of the embodiment shown in FIG. 1 wherein the serpentine blades are positioned on the body or working portion of the balloon.
FIG. 14 is a side view of the embodiment shown in FIG. I wherein the serpentine blades are positioned on the body or working portion of the balloon, the serpentine blades having different lengths.
DETAILED DESCRIPTION OF THE INVENTION
While this invention may be embodied in many different forms, there are described in detail herein specific preferred embodiments of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated.
For the purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated.
As indicated above, the present invention is embodied in a variety of forms.
In at least one embodiment, an example of which is depicted in FIG. 1 , the invention is directed to a catheter balloon 10 which has at least one serpentine, undulating, or similarly configured blade 12 mounted to the external surface 14 of the balloon. As shown, the blade 12 comprises at least one serpentine region 20 . The majority or all of the blade may have a serpentine configuration, the blade may comprise a single serpentine region or any number of serpentine regions separated by non-serpentine regions. In the example shown in FIG. 1 , the blade 12 may be characterized as having a number of adjacent serpentine regions: body region 20 , proximal cone region 22 and distal cone region 24 ; as well as one or more linear or non-serpentine regions: proximal end region 30 , proximal cone transition region 32 , distal cone transition region 34 , and distal end region 36 . The blade 12 extends substantially parallel to longitudinal axis 37 of the balloon 10 .
In an alternative embodiment depicted in FIG. 13 , each blade 12 is in effect a body region 20 having an uninterrupted serpentine configuration extending along at least a portion of only the balloon body 40 .
As is shown in FIG. 1 and FIG. 13 the body serpentine region 20 extends along the exterior surface 14 of at least a portion of the balloon body 40 . The body region 20 may be engaged to the balloon body 40 in any of a variety of ways such as by mechanical engagement, direct welding, through the use of an adhesive, etc. In the embodiment shown an adhesive material 18 is positioned on the surface 14 of the balloon 10 and the body region 20 of the blade 12 is adhesively engaged thereto.
Any suitable adhesive may be utilized as the adhesive material 18 . For example adhesives such as polyurethane, epoxy, cyanoacrylate and/or combinations of such materials may by utilized as the adhesive material 18 . In at least one embodiment, portions of the blade 12 are adhesively engaged to the balloon surface with a polyurethane substrate or pad such as is described in U.S. Pat. No. 5,320,634, the entire contents of which being incorporated herein by reference.
The nature of the serpentine regions 20 , 22 , 24 of the blade 12 is such that each serpentine region comprises a series of adjacent substantially S-shaped segments 50 (highlighted) which extend from a low point or trough 52 , immediately adjacent to the surface 14 of the balloon 10 , to a high point or peak 54 , which is a greater distance radially outward from the balloon 10 than the trough 52 .
Adjacent peaks 54 and troughs 52 are engaged by arm portions 56 of the blade 12 . Each trough 52 is engaged to the balloon surface 14 by the adhesive material 18 . The arm portions extend from the ends of the troughs 52 to engage the adjacent peaks 54 . The arms 56 provide the peaks 54 with a significant degree of axial and transverse flexibility relative to the troughs 52 engaged to the balloon 10 . As a result, when the balloon is twisted, bent, expanded or lengthened, stress between the blade 12 and the balloon 10 is minimized as the majority of the body serpentine region 20 remains free to move in conjunction/response with the movements of the balloon, while only the discrete and separated troughs 52 remain secured to the balloon 10 .
Such a configuration provides the cutting balloon 10 with improved resistance to delamination of the blade 12 from the balloon surface 14 by reducing the axial and transverse stress that the balloon/blade interface is subjected to during expansion and/or movement of the balloon.
In some embodiments where the blade(s) 12 extend beyond the length of the balloon body 40 , such as is shown in FIGS. 1-5 , one or more blades 12 may be provided with cone regions 22 and 24 which also have a serpentine configuration. The cone regions 22 and 24 can be configured such that they elongate during balloon inflation resulting in a tension within the cone regions. Such tension will facilitate a desirable balloon refold, because during balloon deflation the cone region tension will preferentially draw in the blades 12 to a lower profile than the adjacent balloon folds. The serpentine configuration of the cone regions 22 and 24 provide additional flexibility, particularly in the axial direction, which allows the blade to accommodate expansion and/or elongation of the cones 42 and 44 , respectively, as the balloon 10 is expanded without affecting the position or exerting axial stress on the body region 20 of the blade 12 .
In order to minimize profile and to aid in balloon folding/refolding, in some embodiments the cone regions 22 and 24 are spaced apart or separated from the body region by a non-serpentine cone transition region 32 and 34 . In other embodiments regions 32 and 34 may be serpentine, linear, or provided with any other configuration desired.
In at least one embodiment the transition regions 32 and 34 as well as the serpentine cone regions 22 and 24 are not adhesively or otherwise engaged to the balloon surface 14 . By not adhering the respective regions to the balloon, the blade 12 is more readily able to accommodate much greater degrees of change in the shape and configuration of the balloon without placing stress on the body region 20 .
The end regions, proximal end region 30 and distal end region 36 are also typically non-serpentine in configuration, in order to minimize their profile and to provide greater surface area for engagement to the balloon waists (proximal waist 46 and distal waist 48 ) respectively thereunder. In some embodiments the end regions 30 and 36 may be configured to extend beyond the waists 46 and 48 and engage the catheter shaft 60 directly.
In at least one embodiment, at least a portion of each end region 30 and 36 of the blade 12 , is completely encased or enclosed by adhesive or other mounting material upon or within the respective waist of the balloon 10 or catheter shaft 60 .
As is illustrated in FIGS. 1-6 , the balloon 10 may be equipped with any number of blades 12 , typically between 1 and 20, though other numbers may be provided. In FIGS. 1-2 for example, the balloon 10 is shown with a single blade 12 . In the embodiment shown in FIGS. 3-4 , the balloon 10 is provided with a pair of radially opposite blades 12 . In FIGS. 5-6 , the balloon is provided with four substantially circumferentially equidistant blades 12 .
While the embodiments shown in FIGS. 2-6 have blades 12 arranged in a symmetrical fashion about the balloon 10 , such symmetry need not be the case in all embodiments. In some embodiments the blades may be of different or equal lengths; varyingly spaced apart, whether randomly or in accordance with a pattern; or otherwise arranged or positioned about the balloon in accordance with need, desire and/or performance.
As is the nature of a “cutting blade” one or more portions of the surface 62 of the blade 12 define one or more cutting edges. In the various embodiments shown herein at least the peak portions 54 of the body region 20 define a single radially outward projecting cutting edge 64 . As is illustrated in FIG. 7 and in the cross-sectional views provided in FIGS. 11 and 12 the cutting edge 64 can be formed within the body region 20 with a substantially triangular cross-sectional shape, wherein the edge 64 is formed by the peak or apex 64 of the triangular shaped blade. While it is desired to provide at least the peaks 54 with an edge, in at least one embodiment, as illustrated in FIG. 12 , the troughs 52 may also be provided with an edge 64 as a consequence of the triangular cross-sectional shape of the region 20 .
In the embodiments depicted in FIGS. 1-12 , the portions of the blade 12 adjacent to the body region 20 of the blade need not be provided with an edge, (as such portions are typically not positioned in such a manner so as to contact a lesion site). In some embodiments, those regions of the blade other than the body region 20 (e.g. regions 22 , 24 , 30 , 32 , 34 and 36 ) of the blade 12 can be configured with a cross-sectional shape different than that of the body region 20 .
For example, as illustrated in FIGS. 7-10 , the regions 22 / 24 , 30 / 36 , 32 / 34 adjacent to the body region 20 are provided with comparatively thin, or ribbon-like cross-sectional shape, as shown in FIGS. 8-10 , which provides those portions of the blade adjacent to the body region 20 with a high degree of axial and/or transverse flexibility. It should be understood that the ribbon-like shape shown in FIGS. 8-10 is an example of a desired shape, others include but are not limited to, round, ovoid, ellipsoid, square, triangular, or any other geometric shape that may be desired.
The blade 12 , regardless of its cross-sectional shape or shapes may be constructed by any of a variety of manufacturing methods. For example, the blade 12 , or at least the body region 20 may be constructed of metallic or other material wire stock, as it will facilitate the formation of the cutting edge. Other manufacturing techniques include photo-etching, laser cutting, water jet cutting, or flat stock stamping of a desired blade material to form one or more regions of the blade 12 .
In some embodiments the blade 12 or one or more portions thereof may include one or more areas, coatings, materials, etc. that is (are) detectable by imaging modalities such as X-Ray, MRI or ultrasound. In some embodiments at least a portion of the blade is at least partially radiopaque.
In at least one embodiment, the blade 12 , and/or the balloon 10 may be configured to deliver one or more therapeutic agents to the lesion site. A therapeutic agent may be a drug or other pharmaceutical product such as non-genetic agents, genetic agents, cellular material, etc. Some examples of suitable non-genetic therapeutic agents include but are not limited to: anti-thrombogenic agents such as heparin, heparin derivatives, vascular cell growth promoters, growth factor inhibitors, Paclitaxel, etc. Where an agent includes a genetic therapeutic agent, such a genetic agent may include but is not limited to: DNA, RNA and their respective derivatives and/or components; hedgehog proteins, etc. Where a therapeutic agent includes cellular material, the cellular material may include but is not limited to: cells of human origin and/or non-human origin as well as their respective components and/or derivatives thereof. Where the therapeutic agent includes a polymer agent, the polymer agent may be a polystyrene-polyisobutylene-polystyrene triblock copolymer (SIBS), polyethylene oxide, silicone rubber and/or any other suitable substrate.
Blade 12 , may be constructed from one or more metals, polymers, combinations of one or more metals and/or polymers, and/or other desired material(s). In at least one embodiment, blade 12 is at least partially constructed of a shape memory material, such as nitinol and/or a shape memory polymer. The blade 12 , may comprise a plurality of separate blade segments or may be a single continuous structure as desired.
The balloon 10 may be made of any suitable balloon material including compliant and non-compliant materials and combinations thereof. Some examples of suitable materials for constructing the balloon 10 include but are not limited to: low pressure, relatively soft or flexible polymeric materials, such as thermoplastic polymers, thermoplastic elastomers, polyethylene (high density, low density, intermediate density, linear low density), various co-polymers and blends of polyethylene, ionomers, polyesters, polyurethanes, polycarbonates, polyamides, poly-vinyl chloride, acrylonitrile-butadiene-styrene copolymers, polyether-polyester copolymers, and polyetherpolyamide copolymers; copolymer polyolefin material available from E.I. DuPont de Nemours and Co. (Wilmington, Del.), under the trade name Surlyn™; ionomer and a polyether block amide available under the trade name PEBAX™; high pressure polymeric materials, such as thermoplastic polymers and thermoset polymeric materials, poly(ethylene terephthalate) (commonly referred to as PET), polyimide, thermoplastic polyamide, polyamides, polyesters, polycarbonates, polyphenylene sulfides, polypropylene and rigid polyurethane; one or more liquid crystal polymers; and combinations of one or more of any of the above.
In some embodiments a balloon 10 may be provided with one or more blades having different lengths, sizes, shapes, or configurations. For example, FIG. 14 depicts a balloon 10 having two blades, 12 ( a ) and 12 ( b ), with lengths L 1 and L 2 , respectively, where length L 1 is greater than length L 2 . In at least one embodiment one or more blades on a balloon have a length which extend from at least the body of the balloon and through at least a portion of the balloon waist, while the distal end of the blade terminates before reaching the distal waist. This and other configurations and arrangements of blades should be recognized as falling within the scope of the present invention.
The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim 1 such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.
|
A system for treatment of a vessel lesion comprises an expandable balloon and at least one cutting blade engaged to an exterior surface of the balloon. At least a portion of the cutting blade has a substantially serpentine configuration defined by a plurality of interconnected peaks and troughs wherein each trough is in closer proximity to the balloon than each peak.
| 0
|
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2011/002533, filed on May 20, 2011, which claims the benefit of priority to Serial No. DE 10 2010 023 887.2, filed on Jun. 15, 2010 in Germany, the disclosures of which are incorporated herein by reference in their entirety.
The present disclosure relates to a method and to an apparatus for preventing a transverse oscillation of a tower of a wind power plant.
BACKGROUND
In wind power plants with a horizontal axial and three rotor blades, the rotational speed above the rated wind speed is regulated by synchronous adjustment of the blade angles in such a way that changing the pitch angle causes the aerodynamic lift and therefore the driving torque to be changed in such a way that the plant is kept within the range of the rated rotational speed. At wind speeds above the switch-off speed, this blade adjustment mechanism is also used as a brake by virtue of the fact that the blades are positioned into the wind with the nose, with the result that the rotor no longer supplies any appreciable driving torque.
During this collective blade adjustment, pitching moments and yawing moments acting on the rotor are produced owing to asymmetric aerodynamic loads. The asymmetric loads arise, for example, as a result of wind shear in the vertical and horizontal directions, owing to boundary layers, as a result of the imprecise orientation of the wind power plant in the wind, gusts and turbulence or as a result of accumulation of the flow at the tower. In order to reduce these asymmetric aerodynamic loads, the pitch angle of the blades can be adjusted individually (Individual Pitch Control, IPC).
WO 2008/041066 A1 is concerned with controlling a rotor load of a wind turbine. In this context, the fore-aft oscillation, that is to say the oscillation in the direction of the wind, can be damped by collective pitching, during which process attempts are made to avoid generating any symmetrical blade oscillation.
DE 297 15 249 U1 describes a wind power plant having a rotor and at least one rotor blade which is mounted on the rotor so as to be rotatable about its longitudinal axis. In order to adjust a rotor blade angle, an adjustment device is provided which is configured to reduce a yawing moment and/or pitching moment which is applied to the rotor.
SUMMARY
The object of the present disclosure is to provide an improved method and an improved apparatus for preventing a transverse oscillation of a tower of a wind power plant.
This object is achieved by means of a method and an apparatus for preventing a transverse oscillation of a tower of a wind power plant as disclosed herein.
The present disclosure is based on the realization that the transverse oscillations of the tower of a wind power plant can be damped by using individual pitch angles of the rotor blades for that purpose. The object of an IPC controller according to the disclosure is therefore, by individually setting the pitch angles of the plates, not only to reduce the pitching moments and yawing moments but additionally also to damp the lateral tower oscillations.
A further realization of the present disclosure is that known IPC control can excite transverse oscillations of the tower. According to the disclosure this can be prevented by configuring the IPC controller in such a way that it does not excite the transverse oscillations.
The approach according to the disclosure can therefore be advantageously used in conjunction with a known IPC controller with which asymmetrical aerodynamic loads acting on the wind power plant can be reduced by individually adjusting the pitch angles of the blades. In this context, sensors are typically mounted in or on the rotor blades in order to measure the flexural bending torques on the rotor blades. These flexural bending torques then serve as controlled variables for the individual blade adjustment. The pitching moments and yawing moments can also be determined by measuring the gondola acceleration using gyrometers or by means of sensors which use distance measurements to measure the deformations of plant parts occurring as a result of the loads, and thereby determine the loads.
According to the disclosure, a reduction in the pitching moments and yawing moments is advantageously possible by means of IPC without the lateral tower oscillation being excited, and it is possible to damp the lateral oscillation by means of IPC without the pitching moment becoming unacceptably large.
The present disclosure provides a method for preventing a transverse oscillation of a tower of a wind power plant having at least two rotor blades with adjustable pitch angles, which method comprises the following step: determining one or more manipulated variables for setting the pitch angles on the basis of information about a pitching moment and a yawing moment of the rotor, wherein a counteracting torque is generated which counteracts the pitching moment and the yawing moment without exciting a transverse acceleration of the tower head when the pitch angles are set on the basis of the manipulated variable.
The method can be used, for example, in a wind power plant which has a tower at whose upper end a rotor is arranged. The rotor is mounted so as to be rotatable about a rotor axis which is substantially perpendicular with respect to the longitudinal axis of the tower. The transverse oscillation of the tower can occur in a direction which is oriented substantially perpendicularly with respect to the longitudinal axis of the tower and perpendicularly with respect to the rotor axis. The rotor can have three rotor blades. Each of the rotor blades can be mounted so as to be capable of rotating about its longitudinal axis on the hub individually and independently of the other rotor blades. Rotation about the longitudinal axis of a rotor blade is defined in each case by means of the pitch angle. The manipulated variable is suitable for defining an individual pitch angle for each of the rotor blades. On the basis of the manipulated variable, the pitch angles can be determined in accordance with a predetermined determination rule. Alternatively, the manipulated variable can already define the pitch angles. The manipulated variable can be designed to determine the pitch angles as a function of an angular position of the rotor by means of which a position of the rotor blades is defined. The manipulated variable can be determined by means of an IPC controller. The controller can be determined in accordance with a suitable controller design method in which the pitching moment, the yawing moment and the transverse acceleration are included. For this purpose it is possible to take into account the fact that a transverse acceleration of the tower is dependent on a portion of the manipulated variable which can influence the pitching moment. The aerodynamics of the wind power plant, which can be approximated, for example, by deriving a rotor blade torque according to the pitch angle of the rotor blade, can also be included in the controller design method. The pitching moment and the yawing moment can be based on current measured values or on a time profile of detected measured values. In this context, the pitching moment and the yawing moment can be measured directly or determined from measured values. Respectively suitable sensors can be used for the measurement. The pitching moment defines a pitching moment which acts on the rotor about a transverse axis which is substantially perpendicular with respect to the longitudinal axis of the tower and perpendicular with respect to the rotor axis. The yawing moment defines a torque which acts on the rotor substantially about the longitudinal axis of the tower. The transverse acceleration defines acceleration of the rotor or of the upper end of the tower in the direction of the transverse oscillation. When wind flows against the rotor blades during operation, they respectively develop a thrust force. The thrust force acts respectively on the rotor and the tower. By means of the pitch angles it is possible to influence the thrust forces. According to the disclosure, the manipulated variable can be determined from current values or time profiles of the pitching moment and of the yawing moment in such a way that the pitching moment and the yawing moment are reduced. In addition, the manipulated variable can be determined in such a way that the transverse oscillation is either not excited or else an existing transverse oscillation is damped.
According to one embodiment, during the determination of the manipulated variable the first natural frequency of the tower is suppressed with respect to the transverse oscillation in a time profile of the manipulated variable. For this purpose, the impulses which excite the first natural frequency, in particular in a portion of the manipulated variable which can influence the pitching moment, can be suppressed. The corresponding pulses can be suppressed using one or more filters. For example, a low-pass filter or a bandpass filter can be used. The low-pass filter can filter out frequency ranges in the region of the first natural frequency and above, and thereby suppress them. The bandpass filter can filter out frequency ranges in the region of the first natural frequency and thereby suppress them. In addition or as an alternative to a filter it is also possible to perform a limitation of the rate of change for the time profile of the manipulated variable. In this way excitation of the transverse oscillation can be suppressed.
The manipulated variable can also be determined on the basis of information about the transverse acceleration of the tower head in such a way that the resulting transverse force counteracts the transverse acceleration when the pitch angles are set on the basis of the manipulated variable. In this way, the transverse oscillation can be actively damped. The information about the transverse acceleration can be based on current measured values or on a time profile of detected measured values. In this context, the transverse acceleration can be measured directly or determined from measured values. Respectively suitable sensors can be used for the measurement. According to the disclosure, the manipulated variable can be determined from current values or time profiles of the pitching moment, of the yawing moment and of the transverse acceleration in such a way that the pitching moment and the yawing moment are reduced and the transverse oscillation is either not excited or is damped.
In this context, the transverse acceleration and the pitching moment are considered together. This makes it possible to avoid the situation in which the pitching moment is reduced at the cost of the transverse acceleration, or vice versa.
According to one embodiment, the manipulated variable can also be designed to set a generator torque of a generator of the wind power plant. In this context, a torque which counteracts the transverse acceleration can be generated when the generator torque is set on the basis of the manipulated variable. The generator can be coupled to the rotor and be arranged at the upper end of the tower. The generator can be connected to the rotor via a rotor shaft and/or a transmission. A rotational movement of the rotor can be converted into electrical energy by means of the generator. The influence of the generator torque can be used, for example, if the influence of the pitch angles is not sufficient to achieve the necessary damping effect.
The manipulated variable can be determined on the basis of information about a pitching moment which is weighted with a first weighting, a yawing moment which is weighted with a second weighting and a transverse acceleration which is weighted with a third weighting of the tower head. In this way, the variables whose damping has priority can be singled out.
For this purpose, in a setting step a ratio of the weightings with respect to one another can be set. As a result, an influence of the manipulated variable on the pitching moment and the yawing moment can be defined in relation to an influence of the manipulated variable on the transverse acceleration when the pitch angles are set on the basis of the manipulated variable. It is therefore possible to set whether the priority is to be on damping the transverse oscillation or reducing the torques. If the ratio of the weightings is shifted in such a way that the pitching moment is weighted more heavily and the transverse acceleration is weighted less, then suppression of the pitching moment is increased but the damping of the transverse oscillation is reduced. On the other hand, if the ratio of the weightings is shifted such that the transverse acceleration is weighted more heavily and the pitching moment is weighted less, the damping of the transverse oscillation is increased but the suppression of the pitching moment is reduced. The influence of the manipulated variable on the transverse acceleration is coupled to the influence of the manipulated variable on the pitching moment. The pitching moment and the yawing moment typically receive the same weighting. However, the pitching moment and the yawing moment can also be weighted differently.
According to one embodiment, the weightings are each made in the frequency range of the pitching moment, of the yawing moment and of the transverse acceleration. As a result, the weightings can be frequency-dependent. For example, low frequencies can be weighted more heavily than relatively high frequencies. The transverse acceleration can also be weighted more heavily in the region of the first natural frequency of the tower than in the adjacent frequency ranges.
The present disclosure also provides a method for preventing a transverse oscillation of a tower of a wind power plant having at least two rotor blades with adjustable pitch angles, which method comprises the following steps: determining a transverse force, acting on the tower, on the basis of deviations of individual pitch angles of the rotor blades with respect to a collective, mean pitch angle of all the rotor blades; and determining a setting value for setting a generator torque of a generator of the wind power plant on the basis of the transverse force and a transverse acceleration of the tower, wherein a torque which counteracts the transverse acceleration is generated when the generator torque is set on the basis of the setting value.
The deviations of the individual pitch angles can be determined by an IPC controller. The collective pitch angle is the same for all the rotor blades and can be selected such that the wind power plant is operated in the rated rotational speed range. The actual pitch angles are obtained from the collective pitch angle and the deviations. The deviations can be selected such that they reduce pitching moments and yawing moments caused by asymmetric aerodynamic loads. This approach makes it possible to damp tower oscillations in the transverse direction independently of the control used to suppress pitching moments and yawing moments by means of individual pitch angles.
The present disclosure also provides an apparatus for preventing a transverse oscillation of a tower of a wind power plant having at least two rotor blades with adjustable pitch angles, having the following features: a device for determining a manipulated variable for setting the pitch angles on the basis of information about a pitching moment and a yawing moment of the rotor, wherein a counteracting torque is generated which counteracts the pitching moment and the yawing moment without exciting a transverse oscillation of the tower when the pitch angles are set on the basis of the manipulated variable; and/or a device for determining a transverse force, acting on the tower, on the basis of deviations of individual pitch angles of the rotor blades with respect to a collective pitch angle of all the rotor blades and for determining a setting value for setting a generator torque of a generator of the wind power plant on the basis of the transverse force and a transverse acceleration of the tower, wherein a torque which counteracts the transverse acceleration is generated when the generator torque is set on the basis of the setting value.
An apparatus can be understood here to be an electrical apparatus which processes sensor signals and outputs control signals as a function thereof. The apparatus can have an interface which can be embodied by hardware and/or software. In a hardware embodiment, the interfaces may be, for example, part of what is referred to as an ASIC system which contains a wide variety of functions of the apparatus. However, it is also possible for the interfaces to be dedicated, integrated circuits and/or to be composed at least partially of discrete components. In a software embodiment, the interfaces can be software modules which are present, for example, on a microcontroller next to other software modules.
A computer program product having program code which can be stored on a machine-readable carrier such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out the method according to one of the embodiments described above when the program is run on an apparatus corresponding to a computer is also advantageous.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will be explained below by way of example with reference to the appended drawings, in which:
FIG. 1 shows a schematic illustration of a wind power plant according to an exemplary embodiment of the disclosure;
FIG. 2 shows a schematic illustration of a rotor, according to an exemplary embodiment of the disclosure; and
FIG. 3 shows a block diagram of a controller according to an exemplary embodiment of the disclosure.
DETAILED DESCRIPTION
Identical or similar elements may be provided with identical or similar reference symbols in the following figures. In addition, the figures of the drawings, the description thereof as well as the claims contain numerous features in combination. To a person skilled in the art it is clear here that these features can also be considered individually or they can be combined to form further combinations which are not described here explicitly.
FIG. 1 shows a schematic illustration of a wind power plant according to one exemplary embodiment of the present disclosure. The wind power plant has a tower 100 which has a tower head 102 in an end region. The tower head 102 can be embodied as a gondola and is mounted so as to be rotatable about a longitudinal axis of the tower 100 . The longitudinal axis can run in the vertical direction, in the direction of a z axis. A rotor 104 of the wind power plant is arranged on the tower head 102 . According to this exemplary embodiment, the rotor 104 has three rotor blades. The rotor 104 is mounted so as to be rotatable about a rotor axis. The rotor axis can run in the horizontal direction, in the direction of an x axis. The rotor axis can be oriented perpendicularly or essentially perpendicularly with respect to the longitudinal axis of the tower. The rotor 104 is coupled, for example, to a generator 106 via a rotor shaft and/or a transmission. A rotational movement of the rotor 104 can be converted into electrical energy by the generator 106 . The generator 106 is arranged in the tower head 102 .
Forces and torques are applied to the rotor 104 by a wind acting on the rotor 104 . These forces and torques may bring about, for example, a pitching moment about a transverse axis of the tower 100 , a yawing moment about the longitudinal axis of the tower and accelerations of the tower head 102 in horizontal directions. The transverse axis of the tower 100 can run in the y direction, perpendicularly or essentially perpendicularly with respect to the longitudinal axis of the tower 100 and the rotor axis. The transverse axis can run through the tower head 102 . The accelerations can act both in the x direction, that is to say parallel to the direction of the wind, as well as in the y direction, that is to say transversely with respect to the direction of the wind. The acceleration in the y direction is referred to below as transverse acceleration and causes a transverse oscillation of the tower 100 .
The forces and accelerations acting on the tower 100 can be measured by means of suitable measuring devices 112 . For this purpose, acceleration sensors and strain gauges which are arranged, for example, on the tower head 102 or on the rotor 104 can be used. According to this exemplary embodiment, the pitching moment, the yawing moment and the transverse acceleration can either be measured directly by means of the measuring devices 112 , or basic values can be measured from which the pitching moment, the yawing moment and the transverse acceleration can be determined. The measuring devices 112 are designed to output information about the pitching moment, the yawing moment and the transverse acceleration to a determining device 114 .
The determining device 114 is designed to determine, on the basis of the pitching moment, the yawing moment and the transverse acceleration, at least one manipulated variable for setting individual pitch angles of the rotor blades of the rotor 104 . In addition, the determining device 114 can be designed to determine values for the individual pitch angles from the at least one manipulated variable and to output said values to a control device 116 . Suitable transformations can be used to determine the pitch angles on the basis of the at least one manipulated variable. The control device 116 is designed to set the rotor blades to the pitch angles defined by the at least one manipulated variable, on the basis of the at least one manipulated variable or the values for the individual pitch angles.
According to one exemplary embodiment, the measuring devices 112 can additionally be designed to detect a bending torque of the rotor blades, and the determining device 114 can be designed to determine the manipulated variable also on the basis of the bending torques or a transverse force acting therefrom on the tower head 102 .
According to a further exemplary embodiment, the determining device 114 can be designed to determine a setting value for a generator torque of the generator 106 as a further manipulated variable. In this context, the determining device 114 can be designed to determine the setting value for the generator torque and the values for the individual pitch angles together, with the result that said values can already be matched to one another during the determining process. Alternatively, the setting value for the generator torque and the values for the individual pitch angles can be determined one after another. In this context, the values for the individual pitch angles are firstly determined. From the values for the individual pitch angles it is then possible to determine which transverse force is acting on the tower head 102 . The setting value for the generator torque can be set in such a way that the generator torque counteracts the transverse force caused by the pitch angles.
Possible embodiments of the determining device 114 are described in more detail with reference to FIG. 3 .
FIG. 2 shows a schematic illustration of a rotor 104 of a wind power plant, according to an exemplary embodiment of the present disclosure. The rotor 104 has three rotor blades which are spaced apart at equal angular intervals. The rotor 104 can carry out a rotational movement about its rotor axis. A rotational angle of the rotational movement is characterized by Ω. The three rotor blades can each be rotated about their longitudinal axis which is oriented substantially perpendicularly with respect to the rotor axis. Corresponding pitch angles are characterized by β 1 , β 2 , β 3 .
FIG. 3 shows a block diagram of a controller, according to an exemplary embodiment of the disclosure. A wind power plant 300 , which can be embodied in the form of the wind power plant shown in FIG. 1 , is shown. An operational controller 330 is designed to receive measured values from the wind power plant 300 and determine setting values therefrom for the wind power plant 300 . The operational controller 330 is designed to determine a value for the generator torque M Gen and values for the pitch angles β 1,2,3 of the rotor blades and output them.
The pitch angles of the rotor blades can be set individually by means of a standard IPC controller 332 , 334 , 336 . The transformation device 332 is designed to determine, on the basis of the flexural bending torques measured at the wind power plant 300 , at the rotor blades, a pitching moment M D acting on the wind power plant 300 and a yawing moment M Q . For this purpose, the transformation device 332 is designed to carry out an inverse transformation, for example a DQ −1 transformation (inverse direct-quadrature transformation) in which a transformation between a three-phase rotating coordinate plant and a stationary coordinate plant is carried out. The controller 334 can be designed to determine manipulated variables β D , β Q on the basis of the pitching moment M D and the yawing moment M Q . The transformation device 336 is designed to determine individual deviations Δβ 1,2,3 of the pitch angles of the rotor blades on the basis of the manipulated variables β D , β Q . For this purpose, the transformation device 336 can be designed to carry out a transformation, for example a DQ transformation (direct-quadrature transformation) in which a transformation between a stationary coordinate system and a three-phase rotating coordinate system is carried out.
The deviations Δβ 1,2,3 are combined with the pitch angles β 1,2,3 output by the operational controller, with the result that the pitch angles β 1,2,3 which are combined with the deviations Δβ 1,2,3 are fed to the wind power plant 300 .
An embodiment of the IPC controller 332 , 334 , 336 is described in detail below.
The IPC control is a possible method for reducing the loads of the wind power plant on the basis of what is referred to as the DQ or Coleman transformation. In this context, the pitch angle β i is calculated for each individual rotor blade from
β i =β CPC +β 1 D cos(Ω i )+β 1 Q sin(Ω i )+β 2 D cos(2Ω i )+β 2 Q sin(2Ω i )+ . . .
Here, β CPC is the collective pitch angle predefined by the operational controller and Ω i , with i=1, 2, 3, is the rotational position of the respective rotor blade, wherein the angle is 0 degree when the rotor blade points vertically upward. The manipulated variables β 1 D and β 1 Q are calculated by the IPC controller in order to adjust the yawing moments and pitching moments of the rotor to zero. If only β 1 D and β 1 Q are used for the individual pitch control, 1p-IPC is referred to. All the β 2 D , β 1 Q and higher are 0 here. In the text which follows, only 1p-IPC is considered. Here, the β 1 D and β 1 Q are calculated by an IPC controller with the objective of adjusting the pitching moments and yawing moments to zero. The procedure is as follows here: the flexural bending torques M i at the three rotor blades are measured. The pitching moments and yawing moments are calculated therefrom by means of the inverse Coleman transformation:
M
_
1
D
=
∑
i
=
1
3
M
i
cos
Ω
i
M
_
1
Q
=
∑
i
=
1
3
M
i
sin
Ω
i
Subsequently, these signals can be filtered by means of a filter F since they have interference components superimposed on them. Alternatively, the pitching moments and yawing moments M 1 D , M 1 Q can also be measured or calculated by means of other methods.
M 1 D =F· M 1 D
M 1 Q =F· M 1 Q
A correspondingly configured controller K can then calculate the setting signals from these measurement signals.
(
β
1
D
β
1
Q
)
=
K
·
(
M
1
D
M
1
Q
)
In order to damp the tower oscillation, the oscillations of the tower can be damped in the direction of the wind by the pitch angle β CPC . For this purpose, a controller measures the tower head acceleration in the fore-aft direction, that is to say in the direction of the wind, and the pitch angle β CPC is calculated in such a way that the thrust force acting on the rotor is correspondingly increased or decreased in order to damp the oscillation with the resulting thrust forces.
The generator torque can be used for damping for the oscillations of the tower transversely with respect to the direction of the wind. If the torque is increased, the tower is deflected more strongly to the side. Given a reduction in the generator torque, the deflection decreases correspondingly. This behavior can then be used to damp the oscillations transversely with respect to the direction of the wind by virtue of the fact that a controller measures the corresponding tower head acceleration and modifies the generator torque in such a way that the transverse oscillation is damped. This method has the disadvantage that as a result the power which is output by the plant to the power network is influenced.
According to the disclosure, the transverse oscillations of the tower of a wind power plant can be damped by using individual pitch angles for that purpose. The objective of the IPC controller is therefore no longer only to reduce the pitching moments and yawing moments but instead additionally to damp the lateral tower oscillations. Furthermore, the IPC control known according to the prior art can excite transverse oscillations of the tower. This is prevented by the disclosure since the IPC controller can therefore be configured in such a way that it does not excite the transverse oscillations.
The approach according to the disclosure is based on the knowledge of the linearized differential equation of the tower transverse oscillation.
y
¨
=
-
C
m
y
-
D
m
y
.
-
A
m
β
1
D
-
k
i
GB
m
M
gen
Here, y is the deflection of the tower in the transverse direction, C is the spring constant and D is the damping constant of the tower. These can be calculated from the configuration data of the tower. m is the tower head mass which is known. The constant k describes the coupling between an acting torque on the tower head and the resulting deflection of the tower head. It can be calculated from the configuration data of the tower. As an approximation it is also possible to use the constant
k = 3 2 tower height
which is applicable for a linear bending bar. i GB is the transmission ratio, M gen is the generator torque. The constant A can be calculated from the aerodynamics of the wind power plant. For this purpose, the characteristic diagram c M (λ, β) of the wind power plant is used. The rotor torque can be calculated using the characteristic diagram. The approximation for the constant A follows from said rotor torque. The following applies here:
A = 3 R ∂ M ∂ β
with the rotor radius R and the partial derivation of the rotor torque according to the pitch angle
∂ M ∂ β
at the instantaneous working point.
As a result, the transverse oscillation is excited by the term
A
m
β
1
D
.
The tower transverse oscillation is only excited by β 1 D . This portion of the pitch angle leads to the pitch angle of the rotor blade being increased if it points upward and reduced if it points downward. In this context, the torque which acts on the rotor shaft remains constant. However, as a result forces acting in the lateral direction are produced and the pitching moment of the plant is influenced. The IPC controller can then therefore use the manipulated variable β 1 D to damp the transverse oscillations and adjust the pitching moment to zero.
Excitation as a result of β 2 D does not occur, and for this reason only 1p-IPC has to be considered here. IPC with an even higher order can lead again to excitations of the transverse oscillation, but in reality is not used since the blades would have to be rotated too quickly for this.
This approach can be implemented in the devices 341 , 342 , 343 , 344 shown in FIG. 3 . In this context, the devices 341 , 342 , 343 , 344 are alternatives which are mutually exclusive. Just one of the variants 341 , 342 , 343 , 344 can be used at any time.
For the different variants 341 , 342 , 343 , 344 of the possibilities for suppressing the excitation of the tower transverse oscillations the following respectively applies:
Δβ i =β 1 D cos(Ω i )+β 1 Q sin(Ω i )+β 2 D cos(2Ω i )+β 2 Q sin(2Ω i )+ . . .
This equation describes the DQ transformation 336 .
The device 341 is arranged instead of the controller 334 . The device 341 is designed either to determine or to influence the manipulated variables β D , β Q on the basis of the pitching moment M D and the yawing moment M Q . If the device 341 is used instead of the controller 334 , the differential equation of the tower transverse oscillation is also taken into account in the configuration of the IPC controller, and the controller is configured in such a way that excitation of the transverse oscillation as far as possible does not occur. This is possible by virtue of the fact that during the configuration it is required that the controller suppresses the first tower natural frequency in β 1 D .
As a result, no active damping of the transverse oscillation takes place, but instead only the excitation of this oscillation is suppressed by the IPC controller.
Device 342 is arranged instead of the controller 334 . The device 342 is designed either to determine or to influence the manipulated variables β D , β Q on the basis of the pitching moment M D and the yawing moment M Q as well as the transverse acceleration a transv measured at the wind power plant 300 . If the device 341 is used instead of the controller 334 , the controller receives the measured tower head transverse acceleration as an additional measuring signal. As a result, the oscillation can be actively damped. The performance can then be significantly improved.
The bending torque of the rotor blades in the plane of the rotor can be used as a further measuring signal. The transverse force can be calculated approximately from the bending torques.
The device 343 is arranged instead of the controller 334 . The device 343 is designed either to determine or to influence the manipulated variables β D , β Q on the basis of the pitching moment M D and the yawing moment M Q as well as the transverse acceleration a transv measured at the wind power plant 300 . In addition, the device 343 is designed to determine a deviation of the generator torque ΔM Gen . The deviation ΔM Gen is combined with the generator torque M Gen which is output by the operational controller, with the result that the generator torque which is combined with the deviation ΔM Gen is fed to the wind power plant 300 . If the device 341 is used instead of the controller 334 , the controller receives the generator torque as a further manipulated variable. As a result, it is possible to influence the tower transverse oscillation not only by means of β 1 D but also by means of the generator torque. The disadvantage of this variant is that the generator torque influences the power output by the plant.
The device 344 can be used in conjunction with an IPC controller 350 of any design. The controller 350 has here the objective of suppressing pitching moments and yawing moments. The controller can receive measurement variables of the wind power plant 300 , for example the bending torques of the rotor blades, and determine deviations Δβ i of the pitch angles on the basis thereof. The deviations Δβ i are combined with the pitch angles β 1,2,3 output by the operational controller, with the result that the pitch angle combined with the deviations Δβ i are fed to the wind power plant 300 . The device 344 is designed to receive the deviations Δβ i and the measured transverse acceleration of the tower and to determine a deviation of the generator torque ΔM Gen on the basis thereof. Deviation ΔM Gen is combined with the generator torque M Gen which is output by the operational controller, with the result that the generator torque which is combined with the deviation ΔM Gen is fed to the wind power plant 300 .
By means of the device 344 , damping of the tower transverse oscillations is independent of the implementation of IPC control by the DQ transformation. As a result, this approach can be implemented for any possible individual pitch controller. It is assumed that any desired IPC controller uses as output variables deviations Δβ i of the pitch angles of the individual blades from the collective pitch angle β CPC as manipulated variables.
Δβ i =β I −β CPC
The resulting transverse force acting on the tower by means of the different pitch angles can then be calculated as
F
y
=
A
∑
i
=
1
3
Δβ
i
cos
Ω
i
In addition, the tower head transverse acceleration is additionally available again as a measurement variable. A controller 344 can then be designed which suppresses excitation of the transverse oscillation by F y by means of an intervention into the generator torque. An intervention by means of the individual pitch angles is not possible in this way since otherwise the existing IPC controller 350 could be unfavorably influenced.
The approaches according to the disclosure make it possible to damp the oscillation transversely with respect to the direction of the wind. The pitching moments which act on the tower head from the rotor are coupled with the lateral force which the rotor applies to the tower head. The yawing moment is independent thereof. According to the disclosure, IPC is used in order to reduce both the pitching moments and the yawing moments as well as to avoid exciting the lateral tower oscillation, such as is possible, for example, by means of the device 334 , or even to damp them, such as is possible by means of the device 341 . For this purpose, the lateral tower head acceleration is measured, as are the pitching moments and yawing moments, for example by means of strain gauges, together with the deflection of the rotor blades in the impacting direction or the bending of the rotor shaft.
As a result a combination of the reduction of the yawing moments and pitching moments occurs in combination with the damping of the lateral tower oscillation. Both aspects are considered by a controller, with the result that in the event of contradictory requirements the controller can weigh up the situation in order to achieve the best reduction.
In the text which follows, an exemplary embodiment is used to describe how the controller can be optimized for this purpose.
The flexural bending torques of the three rotor blades or equivalent variables such as the deflection in the impacting direction and the lateral tower head acceleration are measured on the plant and fed to a controller. The latter outputs as manipulated variables three individual pitch angles for the three rotor blades. In the controller, the pitching moment M D and the yawing moment M Q are calculated from the three flexural bending torques by means of the DQ transformation and filtering. The set moments are then fed, together with the lateral tower head acceleration, to the actual core controller K. The latter calculates the manipulated variables β D , β Q , which are then converted into three individual pitch angles by means of the inverse DQ transformation, and output to the plant.
In the text which follows, an exemplary embodiment is used to describe how the core controller K is designed. Here, the DQ transformation and the signal filtering are not included.
According to this exemplary embodiment, the H-infinity controller design method is used for the controller design. The controller design method searches a controller K for a system P in such a way that the “worst” possible interference at the interference input w is transmitted to the performance output z after having been amplified as little as possible or attenuated as much as possible. The quotient of signal energy(z)/signal energy(w) for the “worst” w is therefore minimized. This quotient is precisely the H-infinity standard of the closed control circuit, composed of the system P and the controller K.
With respect to a wind power plant, a system description of the wind power plant is firstly produced in the form of a differential equation system. The interference input w contains a description of the asymmetry of the wind field which impinges on the plant. Said interference input w is composed of two components vc and vs which describe the vertical and the horizontal oblique flow. The vector composed of the pitching moment M D , the yawing moment M Q and the lateral tower head acceleration is used as the performance output z. Precisely the same vector is also used as a measuring output y.
The performance output is also weighted with a weighting function W. As a result, certain regions in the frequency range can be weighted more heavily, with the result that it is, for example, appropriate to select a relatively high weight in the region of the first natural frequency of the tower for the lateral tower head acceleration so that the latter is particularly well suppressed by the controller. The controller has the pitch angles β D , β Q available as manipulated variables.
The design method finds a controller such that in the performance output the interference w resulting from the various oblique flows can as much as possible no longer be seen. In this context, the interference is suppressed simultaneously in all three components of the performance vector.
As a result of a change in the weighting function, the three components can then be weighed against one another. A high weight can be selected for the pitching moment M D and the yawing moment M Q can be selected for low frequencies. This permits stationary suppression of the interference. A low weight can be selected for the pitching moment M D and the yawing moment M Q and the tower head acceleration for high frequencies. This makes it possible to prevent the manipulated variables from containing high-frequency components which the actuators cannot follow. A high weight can be selected for the lateral tower head acceleration for low frequencies with a maximum (peak) at the first tower natural frequency. As a result, the first tower natural frequency can be suppressed particularly strongly.
It is then still possible to weigh up the pitching moment M D and the yawing moment M Q and the lateral tower head acceleration against one another by virtue of the fact that the individual weighting functions overall are shifted upward or downward. If the weighting of the tower head acceleration is increased, the tower head acceleration is damped more greatly than the moments M D , M Q are reduced. Conversely, the moments M D , M Q are reduced to a greater extent if the moments M D , M Q are weighted more strongly.
After this configuration has been implemented, the controller K is defined. No further adaptation of the controller is therefore performed during operation. The controller automatically selects the optimum intervention within the sense of the formulated requests.
In the time domain there is no cost function in the classic sense. Instead, the cost function is formulated in the frequency domain by means of the selection of the weighting function for the performance output.
The exemplary embodiments shown are selected only by way of example. The exemplary embodiments described permit the tower oscillation excitation to be prevented at the IPC. For the purpose of the inventive combination of the IPC control with a measurement of the transverse acceleration of the tower head it is possible to use an existing or an additional sensor system. An intervention of the IPC controller in the torque control of the generator can lead to power fluctuations. The tower transverse dynamics can also be taken into account only in the configuration of the IPC controller without using additional measuring signals. The approach according to the disclosure can be used for IPC control of wind power plants. Such control can also serve as an add-on for existing plant control systems. Here, the IPC control is not intended to excite any tower transverse oscillations. In addition, the transverse oscillation can be actively damped.
LIST OF REFERENCE NUMERALS
100 Tower
102 Tower head
104 Rotor
106 Generator
112 Measuring device
114 Determining device
116 Control device
300 Wind power plant
330 Operational controller
332 Transformation device
334 Controller
336 Transformation device
341 Controller
342 Controller
343 Controller
344 Controller
350 Controller
|
A method for preventing a lateral oscillation of a tower of a wind power installation having at least two rotor blades with adjustable attitude angles includes determining a manipulated variable for setting the attitude angles on the basis of information about a pitch torque and a yaw torque of the head of the tower. In this context, a counteracting torque is generated which counteracts the pitch torque and the yaw torque without exciting a lateral oscillation of the tower if the attitude angles are set on the basis of the manipulated variable.
| 5
|
This application claims the benefit of U.S. Provisional Application No. 60/102,942, filed Sep. 30, 1998.
BACKGROUND
To view a television program being transmitted to a user's television, the user provides a channel number to the television. In conventional analog broadcast television, this channel number is a reference to a particular frequency band at which the analog signal carrying the television program is broadcast. This frequency band is also referred to as a “physical channel.” The channel number identifies from which frequency band a tuner in the television is to receive. Thus, a channel number indicates a physical channel and the associated program.
In digital broadcast television, a frequency band can carry a signal which is an encoded digital transport stream. When decoded, the transport stream can include one or more streams having various forms of content, such as video or audio for a program, text based information, closed captioning, or any information which can be transmitted digitally. Each of these items can be associated with a different channel number. Accordingly, a single physical channel can include multiple items or “virtual channels.” In this case, a channel number refers to a virtual channel, a particular item encoded within a transport stream, instead of referring to a physical channel.
In addition, content in a transport stream can be related to content broadcast as an analog signal or in a different transport stream. For example, a transport stream can include a high definition television (“HDTV”) version of a program that is also broadcast as an analog signal at a different unrelated frequency band.
SUMMARY
The invention provides methods and apparatus implementing a technique for selecting a channel in a digital television. In one implementation, selecting a channel includes: receiving a major and minor channel number sequence, including a major channel number, a delimiter, and a minor channel number, where the delimiter separates the major channel number and the minor channel number; identifying a physical channel which corresponds to the major and minor channel number sequence by accessing a channel look up table, where the channel look up table includes correspondences between major and minor channel number sequences and physical channels; and identifying a virtual channel table which corresponds to the physical channel, where the virtual channel table indicates a virtual channel which corresponds to the major and minor channel number sequence. Selecting a channel can further include: tuning to the physical channel to receive a signal carried on the physical channel; and decoding the virtual channel from the tuned signal.
In another aspect, an input device for selecting a channel in a digital television includes: a keypad including a plurality of number keys for inputting respective numbers; and a delimiter key for inputting a delimiter, where a channel is indicated by a major and minor channel number sequence which includes a major channel number input through one or more number keys of the keypad, a delimiter input through the delimiter key, and a minor channel number input through one or more number keys of the keypad.
In another aspect, a digital television includes: a display; a tuner including a connection for an externally supplied broadcast signal, where the tuner provides a signal carried on a physical channel selected from the broadcast signal; a channel control circuit which derives major and minor channel number sequences from received control signals, where a major and minor channel number sequence indicates a specific channel carried in the broadcast signal; a channel processing circuit connected to the channel control circuit, the display, and the tuner, where the channel processing circuit causes the tuner to select a physical channel corresponding to the major and minor channel number sequence supplied by the channel control circuit and provide a digital signal carried thereon, decodes a channel indicated by the major and minor channel number sequence in the digital signal, and supplies the decoded channel to the display.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a hand-held remote control which provides efficient input of major and minor channel numbers to select a channel on a digital television.
FIG. 1B shows a remote control and a digital television.
FIG. 2A is a flowchart of a process for directly entering channel numbers for a major and minor channel number sequence using a keypad.
FIG. 2B is a flowchart of a process for processing number sequences entered using a keypad.
FIG. 3 shows a process for selecting a channel using channel commands.
FIG. 4 is a flowchart of a process for selecting a virtual channel through a menu shown on a display.
FIG. 5 is a flowchart of a process for processing major and minor channel number sequences in a digital television.
DETAILED DESCRIPTION
The Advanced Television System Committee (“ATSC”) established a standard protocol for transmission of data tables for use with digital television. This protocol is referred to as the Program and System Information Protocol (“PSIP”) and is described in “Program and System Information Protocol for Terrestrial Broadcast and Cable,” document A/65, Dec. 23, 1997 published by the ATSC. The information describing the content of a transport stream for a physical channel is referred to as the PSIP for that physical channel.
In digital television, each channel in a transport stream is a virtual channel associated with a major channel number and a minor channel number. A major channel number can be used to identify channels which belong to a common broadcast corporation or other group. A minor channel number specifies a particular channel in such a group. In one example, all the virtual channels in a transport stream have the same major channel number and have respective minor channel numbers. In addition, virtual channels can have as a major channel number the channel number of a physical channel carrying a related analog channel (analog channels do not need minor channel numbers). In another example, a program is transmitted as an analog signal on physical channel 2. The HDTV version of the same program is transmitted in a transport stream, such as within an unrelated frequency band on a different physical channel, and the virtual channel for that HDTV program has the major channel number 2. Thus, a physical channel can be indicated by a major channel number and a virtual channel can be indicated by a major and minor channel number pair.
The PSIP describes the information for all the virtual channels in a transport stream. The PSIP includes a virtual channel table (“VCT”) which describes the correspondence between major and minor channel numbers and the virtual channels. A digital television uses the VCT to interpret a user's input to select the appropriate major and minor channel number and hence the desired virtual channel.
FIG. 1A shows an implementation of an input device as a hand-held remote control 100 which provides efficient input of major and minor channel numbers to select a channel on a digital television. Remote control 100 includes at least one keypad 102 . Keypad 102 includes one or more number keys 105 , such as 10 number keys labeled 0-9, a delimiter key 110 , an enter key 115 , and one or more channel command keys 120 , such as keys labeled with plus (“+”) and minus (“−”). In an alternative implementation, a keypad includes alphanumeric keys so that a user can enter combinations of letters and/or numbers to identify a channel, such as “SNN.HDTV”. Alphanumeric labels can be set by the user or provided automatically, such as through a broadcast signal in a transport stream.
A user enters channel numbers by depressing one or more number keys 105 . A user indicates the separation between a major channel number and a minor channel number by depressing delimiter key 110 . A sequence of a major channel number, a delimiter, and a minor channel number is a major and minor channel number sequence. Because delimiter key 110 is provided on remote control 100 , a user can conveniently enter a major and minor channel number sequence to access a specific channel directly.
Delimiter key 110 is marked with a delimiter. In FIG. 1A, delimiter key 110 is marked with a dot (“.”). This delimiter can take any form, for example, and not by way of limitation, a slash (“/”), a space (“ ”), or a dash (“-”). The choice of a dot as the delimiter is advantageous as being a familiar break in numeric representation in the decimal system. In one implementation, the delimiter is implemented as a predetermined break or arrangement of memory storage, rather than a separately stored character. In another implementation, the delimiter is indicated by inputting a major channel number with a first keypad and a minor channel number with a second keypad (shown in FIG. 1 B).
To complete a channel number entry, the user can depress enter key 115 . An automatic timeout can also complete a channel number entry if the user does not depress any key for a specified period. The user enters channel commands by depressing one of one or more channel command keys 120 , such as to change to a sequentially adjacent channel. For example, in one implementation, to change from the current channel to the sequentially next channel, the user can depress a channel command key 120 marked with a plus (“+”).
FIG. 1B shows remote control 100 and a digital television 150 , with the control 100 potentially having one or more keypads (two shown) and alphabet keys 101 . Digital television 150 includes a display 155 , such as a cathode ray tube (“CRT”), a tuner 160 , a channel control circuit 165 , and a channel processing circuit 170 . These components can be implemented separately or in combination. In one implementation, digital television 100 also includes an integrated keypad for entry of channel numbers and commands directly into digital television 150 .
Remote control 100 sends control signals to digital television 150 according to keys depressed by the user. Channel control circuit 165 receives the control signals. Channel control circuit 165 recognizes channel commands or combinations of channel numbers and delimiters to select a desired physical or virtual channel. For example, in an implementation where the delimiter is a dot, channel control circuit 165 recognizes the sequence “4.2” as a request for major channel number 4 and minor channel number 2. Channel selection is described further below with respect to FIGS. 2A through 5. Channel control circuit 165 provides channel information, such as major and minor channel numbers, to channel processing circuit 170 .
Channel processing circuit 170 uses the channel information from channel control circuit 165 and information stored in a channel look up table 175 to determine the desired physical or virtual channel. Channel look up table 175 is implemented as writeable memory, such as RAM or flash ROM. Channel processing circuit 170 creates channel look up table 175 during initialization of digital television 150 and updates channel look up table 175 dynamically. Channel look up table 175 defines correspondences between major and minor channel numbers and physical and virtual channels. The allocation of minor channel numbers is derived from information obtained from the PSIP of digital physical channels. Major channel numbers correspond to physical channels, which may be different from the physical channels carrying the transport streams. Channel look up table 175 also indicates whether each physical channel is an analog channel or a digital channel.
Channel processing circuit 170 causes tuner 160 to select a physical channel from a broadcast signal received at digital television 150 . The broadcast signal can be received through various reception systems, such as an antenna, a cable system (e.g., CATV), or a satellite system (e.g., DSS). Tuner 160 provides a signal on the selected physical channel to channel processing circuit 170 .
When the channel information indicates a physical channel is desired, such as an analog channel, channel processing circuit 170 passes the signal from tuner 160 to display 155 unchanged. When the channel information indicates a virtual channel is desired, channel processing circuit 170 performs appropriate digital signal processing to extract information from a transport stream based on information supplied in the VCT. For example, channel processing circuit 170 can extract and decode, using decoding such as MPEG-2, a video signal and an audio signal from a transport stream which corresponds to a desired virtual channel. Channel processing circuit 170 provides the signal or signals to display 155 .
FIG. 2A is a flowchart of a process 200 for directly entering channel numbers for a major and minor channel number sequence using a keypad, such as keypad 102 shown in FIG. 1A. A user enters a major channel number by depressing an appropriate number key or keys 105 ( 205 ). The user enters a delimiter by depressing delimiter key 110 ( 210 ). As discussed above, the delimiter indicates the end of the major channel number. For example, the delimiter allows a user to enter directly and distinguishably the sequences “42.3” and “4.23.” The user enters a minor channel number by depressing an appropriate number key or keys 105 on remote control 100 ( 215 ). The user completes the sequence by depressing enter key 115 ( 220 ). The major channel number, delimiter, and minor channel number can be supplied to the channel control circuit separately or together.
FIG. 2B is a flowchart of a process 250 for processing number sequences entered using a keypad, such as keypad 102 shown in FIG. 1A, to generate a channel number sequence in a digital television, such as in channel control circuit 165 shown in FIG. 1 B. As described above, a major and minor channel number sequence includes a major channel number, a delimiter, and a minor channel number. A physical channel number sequence includes a channel number.
When channel control circuit 165 receives an entry of a channel number, and is not already processing another channel number sequence, channel control circuit stores the received number as the first digit of a current channel number ( 255 ). Channel control circuit 165 causes display 155 to display the received channel number and entries as entries are received for user feedback. Channel control circuit 165 waits to receive another entry for a specified timeout period ( 260 ). If channel control circuit 165 does not receive another entry before the timeout period expires ( 262 ), channel control circuit 165 passes the current channel number to channel processing circuit 170 as a physical channel number sequence ( 265 ). If channel control circuit 165 receives a completion signal, such as from enter key 115 , before the timeout period expires ( 267 ), channel control circuit 165 passes the current channel number to channel processing circuit 170 as a physical channel number sequence ( 265 ).
If channel control circuit 165 receives another channel number before the timeout period expires, channel control circuit 165 concatenates the new channel number with the current channel number as the next digit ( 255 ). Channel control circuit 165 resets the timeout period to wait for another entry ( 260 ).
If channel control circuit 165 receives a delimiter before the timeout period expires, channel control circuit 165 concatenates the delimiter with the current channel number ( 270 ). Channel control circuit 165 resets the timeout period to wait for another entry ( 275 ).
If channel control circuit 165 does not receive another entry before the timeout period expires, channel control circuit 165 passes the current channel number to channel processing circuit 170 as a major and minor channel number sequence ( 280 ). If the current channel number ends with a delimiter, channel control circuit 165 concatenates a default value, such as zero, with the current channel number before passing the current channel number to channel processing circuit 170 .
Similarly, if channel control circuit 165 receives a completion signal, such as from enter key 115 , or a second delimiter before the timeout period expires, channel control circuit 165 passes the current channel number to channel processing circuit 170 as a major and minor channel number sequence ( 280 ). If the current channel number ends with a delimiter, channel control circuit 165 concatenates a default value, such as zero, with the current channel number before passing the current channel number to channel processing circuit 170 .
If channel control circuit 165 receives another channel number before the timeout period expires, channel control circuit 165 concatenates the new channel number with the current channel number as the next digit ( 285 ). Channel control circuit 165 resets the timeout period to wait for another entry ( 275 ).
For example, to select physical channel 2, an analog channel, a user enters “2” with a number key 105 and then “ENTER” with enter key 115 using remote control 100 as shown in FIG. 1 A. To select virtual channel 4.2—the virtual channel which has major number channel 4 and minor channel number 2—a user enters “4” with a number key 105 , “.” with delimiter key 110 , and then “2” with a number key 105 .
FIG. 3 shows a process 300 for selecting a channel using channel commands, such as using channel command keys 120 as shown in FIG. 1 A. When channel control circuit 165 receives a channel command, channel control circuit 165 determines the type of command ( 305 ). Channel control circuit 165 recognizes a predetermined set of commands, such as those which are available through remote control 100 . Channel control circuit 165 processes the channel command to derive the desired channel ( 310 ). Channel control circuit passes the resulting channel number to channel processing circuit 170 as a channel number sequence ( 315 ).
An analog channel is sequentially before virtual channels with the same major channel number as the channel number of the analog channel. For example, when channel control circuit 165 has received a “+” command and the currently displayed channel is 4, channel control circuit 165 sends a request to channel processing circuit 170 for the next sequential channel. Channel processing circuit 170 checks whether virtual channel 4.1 is available and, if not, whether analog channel 5 is available, and so on. Channel processing circuit 170 returns the resulting channel number to channel control circuit 165 , or alternatively can process the channel number directly.
FIG. 4 is a flowchart of a process 400 for selecting a virtual channel through a menu shown on a display, such as display 155 shown in FIG. 1 B. When channel processing circuit 170 receives a physical channel number sequence from channel control circuit 165 ( 405 ), channel processing circuit 170 checks in the channel look up table 175 whether the selected physical channel is a digital or analog channel ( 410 ). If the physical channel is an analog channel, channel processing circuit 170 causes the tuner 160 to tune to the physical channel to display the broadcast signal on display 150 ( 415 ).
If the physical channel is a digital channel, channel processing circuit 170 causes display 150 to display a menu listing one or more virtual channels associated with that physical channel ( 420 ). To generate the menu, channel processing circuit 170 accesses the VCT of the transport stream on the physical channel. Alternatively, channel processing circuit 170 generates a full channel list of all the channels, virtual and analog, that have the same major channel number as the major channel number which corresponds to the selected physical channel.
In one implementation, channel processing circuit 170 always generates a full channel list for the selected physical channel, whether the physical channel is analog or digital. For example, in the case of an analog physical channel, channel processing circuit 170 obtains the major channel number corresponding to the selected analog physical channel from the channel look up table 175 . Channel processing circuit 170 forms the full channel list by searching channel look up table 175 for all the virtual channels which have that major channel number.
Channel processing circuit 170 receives a selection from the menu made by the user ( 425 ). The user can select entries from menus in various ways, such as by using channel command keys 120 shown in FIG. 1 A. Channel processing circuit 170 uses channel look up table 175 to find major and minor channel numbers corresponding to the selected entry and uses these numbers as a major and minor channel number sequence ( 430 ).
FIG. 5 is a flowchart of a process 500 for processing major and minor channel number sequences in a digital television, such as digital television 150 shown in FIG. 1 B. After receiving a major and minor channel number sequence ( 502 ), channel processing circuit 170 identifies a physical channel and VCT associated with that sequence using channel lookup table 175 ( 505 ). For example, upon receiving the major and minor channel number sequence “4.2” (i.e., a sequence having major and minor channel numbers 4 and 2, respectively), channel processing circuit 170 accesses channel lookup table 175 to determine the associated physical channel, such as physical channel 39. Channel processing circuit 170 also accesses the VCT for physical channel 39, such as through a pointer to the VCT stored in channel lookup table 175 . Channel processing circuit 170 retrieves one or more packet identifiers (“PIDs”) from the accessed VCT for packets in the transport stream on the selected physical channel which correspond to the selected virtual channel ( 510 ). As described above, a major and minor channel number sequence indicates a virtual channel. A single virtual channel can have associated multiple information streams. For example, the VCT may indicate that video data for the selected virtual channel has one PID and audio data has another PID.
Channel processing circuit 170 causes tuner 160 to tune to the selected physical channel ( 515 ). Channel processing circuit 170 extracts and decodes appropriate information from the signal received on the tuned physical channel using the retrieved PID or PIDs ( 520 ). Channel processing circuit 170 supplies this information to display 155 ( 525 ). Channel processing circuit 170 can also supply audio or other information to appropriate components of digital television 150 .
The invention can be implemented in, or in combinations of, digital electronic circuitry, computer hardware, firmware, or software. An implementation can include one or more stored computer programs executable by a programmable system including a programmable processor and memory.
In the implementations described above, information describing virtual channels and mapping between channel numbers and virtual channels and physical channels is carried in the PSIP of digital channels. In alternative implementations, however, this information can be supplied in various ways or in a combination of ways. This mapping information can be provided by out-of-band (“OOB”) signaling, such as in CATV. Alternatively, the mapping information can be provided by in-band signals, such as program guide and mapping information provided on a portion of an analog or digital channel. The information can be provided in real time or periodically, on a single channel or multiple channels. For example, in one such implementation, the channel processing circuit of a digital television builds the channel look up table by combining the mapping information received on multiple channels. A person of ordinary skill in the art will know how to modify the components of the digital television described above to accommodate one or more of these alternative information sources, such as by including additional tuners or software to access and store the mapping information.
In another alternative implementation, the channel selection is used to select a channel without tuning to that channel. For example, a user can select a channel as described above for recording at some future time. In this case, the digital television does not necessarily tune to the selected channel at the time of selection.
This disclosure describes numerous implementations of the invention. However, these implementations are illustrative and not limiting. Additional variations are possible and will be apparent to one of ordinary skill in the appropriate art.
|
Methods and apparatus implementing a technique for selecting a channel in a digital television. In one implementation, selecting a channel includes: receiving a major and minor channel number sequence, including a major channel number, a delimiter, and a minor channel number, where the delimiter separates the major channel number and the minor channel number; identifying a physical channel which corresponds to the major and minor channel number sequence by accessing a channel look up table, where the channel look up table includes correspondences between major and minor channel number sequences and physical channels; identifying a virtual channel table which corresponds to the physical channel, where the virtual channel table indicates a virtual channel which corresponds to the major and minor channel number sequence; tuning to the physical channel to receive a signal carried on the physical channel; and decoding the virtual channel from the tuned signal.
| 7
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2008/058491, filed Jul. 2, 2008 and claims the benefit thereof. The International Application claims the benefits of U.S. provisional application No. 60/958,822 US filed Jul. 9, 2007, both of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to a gas-turbine burner having a plurality of main swirl generators which each have an inlet flow opening formed by the main swirl generator edge.
BACKGROUND OF INVENTION
[0003] In gas turbines combustion air is usually compressed in a multistage compressor and then guided to a number of gas-turbine burners which are arranged on a combustion tube typically guided in an annular shape around the turbine axis. In the effort to carry out combustion in a gas turbine while generating as little NO x as possible, so-called DLN (dry low NOR) systems have been proven. In such systems there are a number of main swirl generators, also referred to as the main swirl generator arranged around a pilot plug in each gas-turbine burner, in which fuel—usually natural gas—is swirled strongly with air to create a stable pilot flame. The compressed air flows through the main swirl generators and is mixed with the fuel in the main swirl generators, in order to burn downstream outside the main swirl generators in a combustion tube. The gas heated up by the combustion is subsequently directed into a working turbine to do work by expansion.
[0004] To keep a burner section of a gas turbine compact, the combustion air compressed in the compressor is usually guided to the gas-turbine burners located radially further outwards so that the compressed air is guided outwards against a direction of flow in the main swirl generators along the gas-turbine burner or their burner casings. To enable it to flow into the inlet flow openings of the main swirl generators, the flow of the compressed combustion air must undergo a reversal in its direction and in doing so flow around a deflection edge of the burner casing and/or of the main swirl generator facing away from the combustion tube.
[0005] The reversal of direction and the flow around a deflection edge can lead to a flowback occurring between the main swirl generators and the burner casing which may possibly even continue into small areas within the main swirl generators. A detaching of the flow at or from the deflection edge can lead to the same effect. This results in an uneven distribution of the flow through the main swirl generators, with the most problematic area—in relation to a radial inner pilot plug—being the radial outer zones of the main swirl generators. The uneven air mass flow and the lower flow speeds resulting therefrom in these problematic zones results during the injection of fuel into these zones in very rich mixtures, for which a high risk of flame flash back exists. The flowback zones, which are also always associated with a transient behavior, increase the tendency to thermo acoustic combustion chamber vibrations.
[0006] U.S. Pat. No. 4,689,961 describes combustion chamber equipment mt with swirl generators and also a cup-shaped bulge with a passage in which the injector and the swirl generator and also an inflow means are accommodated.
[0007] US 2003/0110774 A1 discloses a gas turbine with main flow generators having an inflow opening.
[0008] To solve this problem an attempt has been made to introduce increased combustion air within the main swirl generators in order to make the rich areas leaner. In a similar way only a small proportion of fuel was entered into the problem zones, which leads to a worse mixture and thereby to a higher NO x emission.
SUMMARY OF INVENTION
[0009] An object of the present invention is to specify a gas-turbine burner which exhibits an even air flow in the main swirl generators.
[0010] This object is achieved by a gas-turbine burner of the type mentioned at the start, which features an inflow guide means with a flow guide surface running from one of the inflow openings to an adjacent inflow opening, which is adjoined by the main swirl generator edges forming the inflow openings and which is widened out radially from there. The reversal in direction of the compressed combustion air before the inlet openings can be guided along the flow guide surface by the flow guide surface adjoining the inflow openings, so that the formation of swirling at this point is reduced. This allows vacuum zones which promote a flowback within the main swirl generators to be kept small. This leads to a more even distribution of the flow in the main swirl generator, so a flowback can be greatly reduced or even avoided. The more even inflow also achieves a greater flexibility for the pattern of the premix holes, less flushing air is needed and a loss of pressure in the main swirl generators and at the flow diversion is reduced.
[0011] The flow guide surface of the inflow guide means adjoins the main swirl generator edges of the main swirl generators forming the flow guide surface of the main swirl generators, with a direct impact at the main swirl generator edges not being necessary, but instead a small installation gap being able to remain for successive fitting of the main swirl generator and of the inflow guide means into the gas-turbine burner. The course of the inflow guide means from an inflow opening to the adjacent inflow opening, especially a continuous course, enables swirling of the combustion air between the main swirl generators to be counteracted. The radial widening out of the flow surfaces enables an area radially outside the main swirl generators to be blocked for reducing or avoiding eddies. The radial direction in this case is related to a center around which the main swirl generators are arranged radially.
[0012] Expediently the flow guide surface is curved in a convex shape in the direction of the combustion air flowing around it, so that the combustion air flowing back towards the inflow opening in an arc is guided along the curved flow guide surface.
[0013] Advantageously the flow guide surface adjoins the main swirl generator at the main swirl generator pipes in parallel to the course of the main swirl generator pipes. The parallel nature of the connection enables an abrupt change in direction in the air guidance at the edge between the flow guide surface and the main swirl generator pipe to be avoided. The connection in this case does not have to be at the outermost main swirl generator edge, but can also lie radially within the main swirl generator edge.
[0014] The main swirl generators are arranged central-symmetrically, especially around a pilot burner, and the flow guide surface runs radially outside the main swirl generators. A combustion air flow flowing from radially outside into the main swirl generators of the gas-turbine burner can be guided with little eddying in the critical area radially outside the main swirl generators. The central symmetry can be a circular symmetry, with the main swirl generators being arranged in a circular ring. Centrally-symmetrical polygon or rosette geometries are also conceivable for example.
[0015] In a further advantageous embodiment of the invention the flow guide surface exhibits a central symmetry at a radially outer area and deviates in an area lying further inwards radially from the central symmetry and is adapted to the form of the main swirl generator edges. This change of symmetry from the central symmetry to the symmetry of the individual main swirl generators or main swirl generator edges enables an at least low-swirl flow to be achieved around all main swirl generator edges.
[0016] The flow guide surface is expediently routed in a ring-shape, especially a circular ring shape continuously around the main swirl generators, which enables an even inflow to be achieved from all sides into the gas-turbine burner.
[0017] To achieve a low-swirl guidance of the combustion air in the area of the reversal in direction the flow guide surface is expediently arranged as a type of bead in the inflow direction in front of the main swirl generators. The bead can be formed in the shape of a U-bend with—relative to the direction of flow in the main swirl generators—limbs being arranged downstream.
[0018] In an advantageous embodiment of the invention the flow guide surface runs from a section facing radially outwards to a section facing radially inwards at the inflow opening. In this way the flow can be guided during a complete reversal of direction by the flow guide surface.
[0019] If the section facing outwards forms a central-symmetrical surface, especially an annular surface, and if the section facing inwards forms a surface adapted to the annular shape of the main swirl generator, a flow guided with little swirling can be achieved all around the main swirl generators.
[0020] Expediently the flow guide surface runs with at least an essentially even curvature from the outward-facing section to the inward-facing section. This enables the combustion air reversing its direction to be guided essentially completely from its direction flowing back radially outside the main swirl generators to its direction flowing forwards radially within the main swirl generators. The even curvature is produced here by a circular cut line between the flow guide surface and a plane aligned in the radial direction, with the radial direction relating to the center around which the main swirl generators are arranged. The even curvature does not have to be present in every plane in the radial direction. It is sufficient for it to be realized in a single plane aligned in the radial direction, for example in a plane running through the above-mentioned center and through between the main swirl generators. Expediently the curvature is even in each of the planes running through between the main swirl generators.
[0021] In a further advantageous embodiment of the invention the inflow guide means connects a burner casing running around the main swirl generators to the main swirl generators. A flow of the combustion air radially outside the gas-turbine burner along the burner casing means that the flow in this area is already low-swirl. Connecting the burner casing to the main swirl generator through the inflow means enables the freedom from swirl to be maintained at least essentially to the main swirl generators. In this case the connection advantageously exists to the main swirl generators or in the direct vicinity of the inflow opening.
[0022] An undesired flowback between the burner casing and the main swirl generators can be avoided if the inflow guide means closes off a gap between a burner casing running around the main swirl generators and the main swirl generators. In this case a small installation gap can remain between the burner casing and the main swirl generators, with a gap width of up to 2 mm for example.
[0023] Advantageously the flow guide surface is routed between the main swirl generators. In this way a gap between the main swirl generators or the main swirl generator edges can be closed at least partly.
[0024] The curvature of the flow guide surfaces from the section facing radially outwards to the section facing inwards is also even in the areas between the main swirl generators.
[0025] Advantageously the flow guide surface is guided to the radial depth of the main swirl generator axes of the main swirl generators between the main swirl generators. A gap between the main swirl generators can thus be closed off completely—if necessary except for the installation gap.
[0026] The inflow guide means and the main swirl generators can easily be made simple to install if the inflow guide means is guided radially outside past the main swirl generator edges in its radially inner section. Expediently it is aligned in the axial direction in the immediate vicinity of the main swirl generator edges, so that the main swirl generator or the inflow guide means can simply be pushed in in the axial direction to install them.
[0027] It is also proposed that the gas-turbine burner features an outer and an inner burner casing, surrounding the main swirl generators in each case, which are respectively adjoined by the inflow guide means in the casing direction. In addition to a high level of stability, which is able to be achieved by such an embodiment of the inflow guide means, the combustion air can be guided along a large radius of curvature of the flow guide surface so that a large vacuum along this surrounding flow can be countered. The casing direction here is the direction of the casing at the point of the join and especially the axial direction of the gas turbine burner, so that the flow guide surface is aligned at the connection to at least the outer burner casing, expediently to both burner casings, in the axial direction.
[0028] If the inflow guide means has two arms pointing in the inflow direction, which on the downstream flow side of the inflow opening are especially routed together in parallel, a stable construction and ease of installation of the inflow guide means can be achieved.
[0029] To be able to guide the supports of the gas-turbine burner through the inflow guide means in a simple manner, with simple manufacturing and installation of the inflow guide means, the inflow guide means is expediently embodied in the area of the flow guide surface in a tangential direction in multiple parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The invention will be explained in greater detail on the basis of exemplary embodiments which are shown in the drawings. The Figures show:
[0031] FIG. 1 a cross-sectional diagram through a gas-turbine burner with eight main swirl generators arranged around a central pilot plug,
[0032] FIG. 2 a section through a slightly-modified gas-turbine burner with a slightly-modified inflow guide means,
[0033] FIG. 3 a further bead-shaped inflow guide means in a perspective detailed view
[0034] FIG. 4 the inflow guide means from FIG. 3 in an overall perspective view of the gas-turbine burner,
[0035] FIG. 5 . the inflow guide means in a longitudinal section and
[0036] FIG. 6 an overhead view of a section of the inflow guide surface of the inflow guide means.
DETAILED DESCRIPTION OF INVENTION
[0037] FIG. 1 shows a gas-turbine burner 2 in a longitudinal section with a combustion tube 4 . The gas-turbine burner 2 comprises a pilot burner with a pilot plug 8 , around which eight main swirl generators 10 are arranged in a ring. Each of the main swirl generators 10 has a main swirl generator pipe 12 , within which is arranged a premixing blade 14 with a number of vanes oriented radially outwards. In each of the vanes run a premixing gas duct 16 carrying fuel, which is connected to premixing holes not shown in the figure, through which the fuel is pressed into the interior of the main swirl generator tube 12 . The fuel is guided through feed inlets 18 to each main swirl generator 10 and mixed within the main swirl generator pipe 12 with compressed combustion air.
[0038] The course of a flow of the combustion air flowing around the gas-turbine burner 2 is shown by solid arrows 20 in the figure. The combustion air flows around the gas-turbine burner 2 initially against a direction of flow 22 , which is related to the premixing flow within the main swirl generator 10 . It flows along a burner casing 24 which surrounds all main swirl generators 10 of the gas-turbine burner 2 in order to then flow in an arc around an edge 26 of the burner casing 24 in the direction of an inlet opening 28 of each main swirl generator 10 . The inlet flow opening 28 is surrounded by the main swirl generator edge 30 of the corresponding main swirl generator 10 facing away from the combustion tube 4 .
[0039] The diversion of the flow of the combustion air produces a vacuum zone in the area of the section of the main swirl generator edge 30 , which lies radially outwards in relation to the pilot plug 8 , through which a suction and thereby a reverse flow 32 between the main swirl generator 10 and the burner casing 24 will be created, which is shown in the figure by a dashed-line arrow. This reverse flow 32 continues where necessary into a further reverse flow 34 within the main swirl generator 10 , which ensures a small supply of air there and thus leads to a rich fuel mixture.
[0040] To counter the reverse flows 32 , 34 , the gas-turbine burner 2 , in a simple embodiment of the invention, is equipped with an inflow guide means 36 which runs in an annular shape within the burner casing 24 around all main swirl generators 10 and essentially adjoins the main swirl generator edges 30 of the main swirl generator 10 in parallel. This enables the external reverse flow 32 to be at least largely eliminated, which also significantly reduces the inner reverse flow 34 and thus the flow through the main swirl generator 10 is evened out.
[0041] A more efficient embodiment of the invention is shown in FIG. 2 . The subsequent description of the subsequent exemplary embodiments is essentially restricted to the differences from the embodiment described in FIG. 1 , to which reference is made for features and functions that remain the same. Essentially components which remain the same are basically labeled with the same reference characters.
[0042] An inflow guide means 38 has a convex curved flow guide surface 40 which in the area of the inflow opening 28 essentially adjoins the main swirl generator pipe 12 in parallel. The flow guide surface 40 widens radially outwards and adjoins the burner casing 24 in order to connect the main swirl generator 10 with the burner casing 24 in this way. The inflow guide surface 40 is also curved so that it is aligned radially in the area of the burner casing 24 and is essentially aligned axially at the inflow opening 28 . In addition the inflow guide means 38 closes off a gap 42 between the main swirl generators 10 and the burner casing 24 and for this purpose—as explained in detail for the exemplary embodiment from FIGS. 3 to 6 —is guided between the main swirl generators 10 or between their main swirl generator edges 30 . For easier installation however a small gap can remain between the inflow guide means 28 and the main swirl generator pipe 12 .
[0043] In FIGS. 3 to 6 a further gas-turbine burner 44 is shown with a very efficient inflow guide means 46 . FIG. 4 shows a perspective overhead view of the gas-turbine burner 44 and the inflow guide means 46 , FIGS. 3 and 5 show the inflow guide means in a section executed in an axial direction of the gas-turbine burners 44 , and FIG. 6 shows a section of the inflow guide means 46 in an overhead view in the axial direction or the direction of flow 22 respectively.
[0044] The inflow guide means 46 has a bead-like flow guide surface 48 arranged in the inflow direction 22 in front of the main swirl generators 10 , which connects the main swirl generator edges 30 of the main swirl generators 10 with an outer burner casing 50 which likewise surrounds the main swirl generators 10 . The radial outer burner casing 50 serves to guide the combustion air a little outside the inner burner casing 24 in order to create a curvature of the flow deflection that is not too tight. The connection of the flow guide surface 48 to the outer burner casing 50 running in the axial direction is in the direction of the casing or in the axial direction respectively, so that a flow guidance from the outer burner casing 50 essentially passes seamlessly into the flow guide surface 48 . In the subsequent passage of the flow the compressor air will be guided without any swirl to the inflow opening 28 from a section 52 facing radially outwards to a section 54 facing inwards which ends at the inflow opening 28 , by the flow guide surface 48 embodied in this passage of flow with an essentially even curvature.
[0045] The inflow guide means 46 in this case, as is shown in FIG. 4 , is guided in an annular shape around all main swirl generators 10 and engages radially inwards between the main swirl generators 10 or their main swirl generator edges 30 in order to close off both a gap 58 between the outer burner casing 50 and the main swirl generator pipe 12 and also the gap 42 between the inner burner casing 24 and the main swirl generator pipe 12 . A reverse flow of combustion air through this gap 42 , 58 to the inflow opening 28 will thus be at least largely avoided, with a smaller installation gap 60 between the main swirl generator pipe 12 and the inflow guide means 46 able to remain.
[0046] As can be seen in FIGS. 3 , 4 and 6 , the flow guide surface 48 is drawn radially inwards between the main swirl generators 10 , and this is done to the height of the main swirl generator axes 56 of the main swirl generators 10 in order to suppress a flow of combustion air between the main swirl generators 10 .
[0047] For easier installation the inflow guide means 46 is routed with its radial inner section 54 radially outside past the main swirl generator edges 30 and runs in the axial direction there, so that the main swirl generator 10 can be inserted in the axial direction for installation into the gas-turbine burner 44 . Similarly the radial outer section 52 is routed radially within the outer burner casing 52 and likewise in the casing direction or the axial direction there, so that the inflow guide means 46 can be inserted into the burner casing 50 . In its further course the inflow guide means 46 comprises an inner limb 62 and an outer limb 64 , which are joined together in the direction of flow 22 at the inner burner casing 24 in parallel and attached to the burner casing 24 .
[0048] To attach the gas-turbine burner 44 in a gas turbine the gas-turbine burner 44 comprises a holder 66 with holder elements 68 which are routed through the flow guide surface 48 and attached to the burner casings 24 , 50 . For simple manufacturing and assembly of the inflow guide means 46 it is divided up into a number of segments 70 between which a holder element 68 is routed through in each case.
|
A gas-turbine burner having a plurality of main swirl generators, each having an inlet flow opening formed by the main swirl generator edge, is provided. In order to achieve a uniform flow of combustion air through the main swirl generator, the gas-turbine burner has an inlet-flow guide means with a flow guide surface which runs from one of the inlet-flow openings to an adjacent inlet-flow opening, to which the main swirl generator edges which form the inlet-flow openings are connected, and the flow guide surface widens from there radially upwards. The main swirl generators are central-symmetrically arranged around a pilot burner and the flow guide surface runs radially outside the main swirl generators.
| 5
|
BACKGROUND OF THE INVENTION
The invention is particularly designed for use in the medical field and more particularly for use in the field of detecting hemodynamic pressure.
Prior to the invention it has been customary to measure hemodynamic pressure by connecting a conduit from a blood vessel in a living being to the pressure sensitive wall of a tranducer. The result is that the transducer detects the blood pressure waves. In order to obtain the required sterile conditions, it is necessary to sterilize all surfaces in contact with the fluid connection to the blood system and it is also necessary that such surfaces be of a material which will not introduce objectionable elements to the blood system. Where the fluid containment structure includes the wall of the transducer, so that the fluid contacts the transducer, the transducer must be sterilized after each use. Also it is difficult to make a suitable fluid-tight connection between the conduit and the transducer. Attempts have been made to construct the fluid containment system separate from the transducer and have a diaphragm wall of the fluid containment structure positioned for contact with the transducer wall. This approach would solve the noted problems, but it has not been successful because it has been found that the blood pressure wave is not faithfully transmitted through the diaphragm to the transducer reliably, unless the space between the diaphragm wall and the transducer wall be filled with liquid.
SUMMARY OF THE INVENTION
According to the present invention it has been found that the reason for failure of prior attempts to make a fluid containment structure separate from the transducer without liquid coupling is that when the fluid containment diaphragm is placed against the transducer, gas (air or any other gas) is trapped between the two surfaces and interferes with the precise transmission of the blood pressure wave. The invention solves this problem by providing means for venting gas from the space between the fluid containment diaphragm and the pressure-sensitive wall of the transducer.
Accordingly, an object of the invention is to provide a hemodynamic pressure detecting apparatus which is accurate and yet has a fluid containment structure which is separate from the transducer. In this way, the fluid containment structure can be sterilized alone and there is no need to sterilize the transducer or be concerned about the materials used in the pressure sensitive wall of the transducer. Since the fluid containment structure is inexpensive compared to the transducer, the fluid containment structure may even be thrown away after one use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view partly in section showing the separate fluid containment structure held in place on the transducer; and
FIG. 2 is a bottom view of the diaphragm end wall of the fluid containment structure.
DETAILED DESCRIPTION OF THE INVENTION
As shown in the drawings, the apparatus for detecting hemodynamic pressure comprises a separate fluid containment structure 1 connected to a pressure transducer 2. The fluid containment structure comprises a main body portion 4 which is preferably dome shaped as shown in the drawings. The main body 4 has at least one, and preferably two flexible tubes 5 and 6 connected thereto. Each of the tubes is provided with a conventional three-way valve as indicated at 7 and 8. In conventional operation the valve 8 is used to admit atmospheric pressure for obtaining a zero setting for the apparatus. Tube 5 is connected to the blood system of the patient, and valve 7 permits the attendant to fill the containment structure with liquid such as 0.9% NaCl solution through a side tube 9.
The main body 4 includes a diaphragm end wall 11. The main body 4 and the associated tubing must be of nondistensible construction to avoid attenuating the blood pressure wave, and the diaphragm 11 must be very compliant in order to faithfully transmit the blood pressure wave to the transducer. By way of example the main body 4 can be made of thick plexiglass and the diaphragm 11 can be made of a thin sheet of polyparaxylylene bonded to the main body 4 with a silicone adhesive.
The transducer 2 is a conventional transducer such as Model No. P23DB made by Statham Instrument Division of Gould Company. The transducer has a cylindrical outer wall 14, a pressure-sensitive transducing wall 15 and an electrical lead 16. As is well known in the art, pressure variations against the outer surface of wall 15 will cause electrical output signals from the transducers which signals are representative of the instantaneous pressure against the outer surface of wall 15. The dome-shaped body 4 is held in place on the transducer by a circular nut 18 having a threaded engagement with threads on a downwardly projecting cylindrical wall 19 of the transducer dome. Upward movement of nut 18 is limited by engagement with an annular lip 20 on the transducer, and the nut is prevented from slipping off the transducer by a ring 21 attached to the transducer.
In operation, the dynamic pulse wave as well as the static pressure from the blood system of the patient to which tubing 5 is connected will be transmitted through tubing 5 into the dome shaped body 4 and against the inner surface of diaphragm 11. Since diaphragm 11 responds to pressure in the body 4 with substantially no resistance, diaphragm 11 transmits the blood pressure to the outer surface of pressure sensitive wall 15 of the transducer. According to the invention, it has been found that if the outer surface of diaphragm 11 is flat, gas tends to become trapped between the diaphragm and the pressure sensitive transducer wall 15. It has also been found that such trapped gas causes inaccurate electrical output from the transducer. In accordance with the invention, the problem is solved by venting the interface between diaphragm 11 and wall 15 to remove or substantially reduce the possibility of trapped gases. In a preferred embodiment the venting is accomplished by making the outer surface of diaphragm 11 microscopically corrugated or ridged as shown at 22 so that a network of passages or grooves 23 are provided to vent gas to the atmosphere.
Although diaphragm 11 is drawn relatively thick in order to show its detailed construction, it is intended to be very thin. For example, diaphragm 11 may have a total thickness on the order of 0.005 inch, and the depth of the grooves 23 may be on the order of 0.002 inch. The main considerations are that the diaphragm be sufficiently compliant to offer substantially no resistance to transmission of pressure in dome 4 to the surface of transducer wall 15; and at the same time the material of diaphragm 11 must be sufficiently non-compressible to prevent attenuating the pulse and to prevent collapse of the ridges 22 which would close the gas passages 23. In order to avoid the possibility that gas passing out of grooves 23 will be trapped by dome wall 19 and thus prevent sufficient venting, the inner diameter of wall 19 is larger than the outer diameter of diaphragm 11 to provide an annular passage 25. Similarly, nut 18 is preferably provided with one or more ports 26 for unrestricted venting.
Although the grooves or passages 23 are shown to be all parallel and extending in only one direction, they obviously could be in the form of grooves across the face of diaphragm 11 in two directions at right angles to each other or take other appropriate network form. Also it should be understood that the outer surface of wall 15 could be grooved instead of grooving the surface of wall 11, or they could both be grooved. Similarly, the grooves could be formed by bonding narrow spaced strips of material to the facing surfaces of one or both of the walls 11 and 15 rather than by forming the grooves integrally in the diaphragm 11 as shown. Alternatively the passages could be formed by many spaced bumps instead of continuous ridges. Also, the venting passages could be formed on both sides of a separate compliant sheet placed between wall 15 and diaphragm 11.
While there have been described and illustrated specific embodiments of the invention, it will be clear that variations in the details may be made without departing from the true spirit and scope of the invention as defined in the appended claims and their legal equivalents. For example, it should be understood that while the invention is specifically described in connection with a system for measurement of hemodynamic pressures, it can be utilized in any fluid pressure detecting system. Similarly, it should be understood that the invention is applicable to systems in which the pressure variations originate in the transducer and would then be transmitted through diaphragm 11 to fluid in the container 4 in any situation in which it is desired to create pressure waves in a fluid system.
|
Pressure transducer apparatus primarily for medical use in determining the hemodynamic pressure associated with circulation of the blood. The pressure transducing wall is in contact with a highly compliant diaphragm wall of a fluid container adapted for connection to a patient's blood system. In order to prevent distortion in the blood pressure wave as it is transmitted through the container diaphragm wall to the transducing wall, means are provided for venting air trapped between the diaphragm and the transducing wall.
| 0
|
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/548,441 filed Oct. 18, 2011, the content of which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] This invention relates to MVA vectors and vaccine inserts that are able to be produced at high levels in certain cell lines.
BACKGROUND
[0003] Vaccines have had profound and long lasting effects on world health. Smallpox has been eradicated, polio is near elimination, and diseases such as diphtheria, measles, mumps, pertussis, and tetanus are contained. A Vaccines under development include DNA vaccines and various live vectored vaccines (e.g. Adenovirus type 5 vectors, poxvirus vectors). Live viral vectors can be used either alone or as the boost componenet for a DNA prime or a prime by another live viral vector Modified vaccinia Ankara (MVA) has been particularly effective as a boost for DNA primes in mouse models, non human primates, and humans (Schneider et al., Nat. Med. 4:397-402, 1998, Lai et al, J. Inf. Dis. 204:164-173, 2011, Goepfert et al., J. Inf. Dis. 203:610-619, 2011). MVA is a highly attenuated strain of vaccinia virus that was developed toward the end of the campaign for the eradication of smallpox, and it has been safety tested in more than 120,000 people (Mahnel et al., Berl. Munch Tierarztl Wochenschr 107:253-256, 1994; Mayr et al., Zentralbl. Bakteriol. 167:375-390, 1978). During over 500 passages in chicken cells, MVA lost about 10% of its genome and the ability to replicate efficiently in primate cells. Despite its limited replication, MVA has proved to be a highly effective expression vector (Sutter et al., Proc. Natl. Acad. Sci. U.S.A. 89:10847-10851, 1992), raising protective immune responses in primates for parainfluenza virus (Durbin et al. J. Infect. Dis. 179:1345-1351, 1999), measles (Stittelaar et al. J. Virol. 74:4236-4243, 2000), and immunodeficiency viruses (Barouch et al., J. Virol. 75:5151-5158, 2001; Ourmanov et al., J. Virol. 74:2740-2751, 2000; Amara et al., J. Virol. 76:7625-7631, 2002). The relatively high immunogenicity of MVA has been attributed in part to the loss of several viral anti-immune defense genes (Blanchard et al., J. Gen. Virol. 79:1159-1167, 1998). Vaccinia viruses have been used to engineer viral vectors for recombinant gene expression and as recombinant live vaccines (Mackett et al., Proc. Nati. Acad. Sci. U.S.A. 79:7415-7419; Smith et al., Biotech. Genet. Engin. Rev. 2:383-407, 1984). DNA sequences, which may encode any of the HIV polypeptides described herein, can be introduced into the genomes of vaccinia viruses. If the gene is integrated at a site in the viral DNA that is non-essential for the life cycle of the virus, it is possible for the newly produced recombinant vaccinia virus to be infectious (i.e., able to infect foreign cells) and to express the integrated DNA sequences. The prevalence of HIV infection has made vaccine development for this recently emergent agent a high priority for world health. The development of safe and effective vaccines against existing and emerging pathogens is a major focus of medical research. Considerable effort has been directed to making a vaccine that will protect against human immunodeficiency virus-1 (HIV). Certain MVA vectors expressing HIV polypeptides have been suggested as useful for eliciting an immune response to HIV. It is desirable to be able to produce useful quantities of MVA in cell lines.
SUMMARY
[0004] The present invention provides viral vectors (e.g., recombinant MVA vectors) that are capable of expressing one or more (e.g., two, three, four, five, six, seven, eight, nine, or ten) polypeptides (e.g., HIV proteins or portions thereof and other human genes that modulate immune responses such as GM-CSF (granulocyte-macrophage colony stimulating factor; GenBank NP — 000749) in the cells of a human patient at relatively high levels and can also be produced in significant quantities in cultured cells, e.g., avian cells. The vectors include miRNA target sequences that suppress translation (expression) of the polypeptides in a selected cell type, e.g., a cell used to produce MVA for preparation of an immunogenic composition, but do not significantly reduce expression in one or more other selected cell types (e.g., mammalian cells or human cells). Thus, polypeptide expression is suppressed during production of bulk quantities of MVA, thereby permitting production of large quantities of MVA, and polypeptide expression is not suppressed in a patient to which the MVA is administered.
[0000] miRNA Target Sequences
[0005] The viral vectors include one or more miRNA target sequences in the 3′ untranslated region of the transcript(s) encoding the polypeptides (or the transcript or transcripts encoding the polypeptides and other human genes that modulate immune responses). The miRNA target sequences are selected to repress expression of the polypeptides (or polypeptides and GM-CSF) at the translational levels in the cell line used for production of the MVA while not doing so (or doing so to a lesser extent) in certain human cells, e.g., certain cells of a human patient to which the MVA is administered. Thus, the miRNA target sequences can decrease expression (e.g., by 20%, 40%, 60%, 80%, 90% or more) of the one or more HIV polypeptides (or polypeptides and immune modulator) compared to an otherwise identical MVA vector lacking the miRNA target sequence. In some cases the 3′ untranslated region includes multiple copies of one or more miRNA target sequences. Thus, the region can include at least 1, 2, 3, 4, 5, 6, 8, 10 or more copies of a first miRNA target sequence that is functional in a cell line used to produce the MVA in quantities for producing a pharmaceutical formulation. The 3′ untranslated region can also include at least 1, 2, 3, 4, 5, 6, 8, 10 or more copies of a second (different) miRNA target sequence that is functional in a cell line used to produce the MVA in quantities for producing a pharmaceutical formulation.
[0006] While it can be advantageous to include multiple miRNA target sequences in order to more full repress expression, the presence of multiple target sequences can cause undesirable recombination. Thus, it can be desirable to have a combination of 2 or more (2, 3, 4 or 5) different miRNA target sequences in order to reduce risk of recombination events while still having multiple miRNA target sequences.
[0007] In some cases the miRNA target sequence does not decrease expression of the polypeptides (or polypeptides and GM-CSF) in a cell line used for recombination of the MVA virus (e.g., chicken embryo fibroblasts could include DF1 cells, an immortalized chicken cell line 5 or BHK-21 cells, baby hamster kidney cells lines or other cell line that are sufficiently permissive for MVA growth for production of recombinants). Two broad categories of miRNA targets sequences have been identified: 5′ dominant sites and 3′ compensatory sites. Use of entire targets has been effective in suppressing transgene expression (Brown et a. 2006 Nat Med 12:585-591). One can identify active miRNA sequences for any given cell type. Vendor such as LC Sciences (Houston, Tex.) can profile mRNA isolated from a given cell type and identify miRNA target sequences likely to be selected for that cell type relative to one or more other cell types (e.g., human cell types). Identified miRNA target sequences can be tested for their ability to suppress expression of a reporter such as GFP inserted into MVA under the control of an appropriate expression control sequence.
[0008] In some cases it will be desirable to use a plurality of different miRNA target sequences. The miRNA target sequences can be separated one from another by 1, 2, 3, 4, 5, 10 (or more) nucleotides. Expression in chicken embryo fibroblasts or other cells (e.g., other avian cells or avian stem cells) permissive for MVA production can be tested. In some embodiments expression is not suppressed in mammalian cells (e.g., 293T kidney cells, U937 monocytes) and for expression in human PBMC.
[0009] A database of miRNA sequences and access to miRNA target sequence information can be found on the internet at mirbase.org.
MVA Vectors and HIV Polypeptides
[0010] The invention provides compositions (including pharmaceutically or physiologically acceptable compositions) that contain a MVA vector, having a polypeptide expression sequence. The polypeptide expression sequence can include one or more of the sequences described herein (the features of the polypeptide expression sequence and representative sequences are described at length below; any of these, or any combination of these, can be used as the polypeptide expression sequence). When the polypeptide expression sequence is expressed, the expressed polypeptide(s) may generate an immune response against one or more (e.g., two, three, four, five, or six) infectious agents, e.g., HIV
[0011] The invention also features compositions (including pharmaceutically or physiologically acceptable compositions) that contain, but are not limited to, two vectors: a first viral vector that encodes one or more (e.g., two, three, four, five, six, seven, eight, nine, or ten) polypeptides (i.e., a vector that includes a vaccine insert and/or a sequence expressing an immune modulator such as GM-CSF) that elicit (e.g., induces or enhances) an immune response against an HIV. A MVA vector can encode Gag-Pol or a modified form thereof. In addition, it can encode Gag-Pol and Env or modified forms thereof. The encoded HIV polypeptide can be a variant of a natural-occurring HIV polypeptide that includes one or more point mutations, insertions, or deletions. Particularly useful HIV polypeptide sequences include one or more (e.g., at least two, three, four, or five) safety mutations (e.g., deletion of the LTRs and of sequences encoding integrase (IN), Vif, Vpr, and Nef). The vectors can encode one or more (e.g., two, three, four, five, six, or seven) of Gag, PR, RT, Env, Tat, Rev, and Vpu proteins, one or more (e.g., two, three, four, five, six, or seven) of which may contain safety mutations (particular mutations are described at length below). Moreover, the isolated nucleic acids can be of any HIV Glade and nucleic acids from different clades can be used in combination (as described further below). In the work described herein, Glade B inserts are designated JS (e.g., JS2, JS7, and JS7.1), Glade AG inserts are designated IC (e.g., IC2, IC25, IC48, and IC90), and Glade C inserts are designated IN (e.g., IN2 and IN3). The viral vectors can also encode human GM-CSF (mwlqsllllg tvacsisapa rspspstqpw ehvnaiqear rllnlsrdta aemnetvevi semfdlqept clqtrlelyk qglrgsltkl kgpltmmash ykqhcpptpe tscatqiitf esfkenlkdf llvipfdcwe pvqe; SEQ ID NO: 10). A non-limiting example of a location for insertion of the GM-CSF is shown in FIG. 1 .
[0012] Where the compositions contain MVA vectors that differ either in their backbone, regulatory elements, or insert(s), the ratio of the vectors in the compositions, and the routes by which they are administered, can vary. The ratio of one type of vector to another can be equal or roughly equal (e.g., roughly 1:1 or 1:1:1, etc.). Alternatively, the ratio can be in any desired proportion (e.g., 1:2, 1:3, 1:4 . . . 1:1100, 1:1000; 1:2:1, 1:3:1, 1:4:1 . . . 1:10:1, 1:100:1, 1:1000:1; etc.). Thus, the invention features compositions containing a variety of vectors, the relative amounts of antigen-expressing vectors being roughly equal or in a desired proportion. While preformed mixtures may be made (and may be more convenient), one can, of course, achieve the same objective by administering two or more (e.g., three, four, five, or six) vector-containing compositions (on, for example, the same occasion (e.g., within minutes of one another) or nearly the same occasion (e.g., on consecutive days)).
[0013] In any of the above described viral vectors, the polypeptide expression sequence can contain a sequence that encodes one or more (e.g., two, three, four, five, six, seven, eight, nine, or ten) polypeptide selected from the group of: gag, gp120, pol, env, Tat, Rev, Vpu, Nef, Vif, and Vpr. In additional embodiments of all the above vectors and polypeptide expression sequence, the one or more (e.g., two, three, four, five, six, seven, eight, nine, or ten) polypeptides (e.g., Gag, Env, Pol, Env, Tat, Rev, Vpu, Nef, Vif, and Vpr) is a mutant or a natural variant or a fragment of a natural polypeptide. In any of the above viral vectors and vaccine inserts, the polypeptide expression sequence can contain a sequence that encodes gag, pol, Tat, Rev, and env. In additional embodiments of the above vectors and vaccine inserts, the insert can contain a sequence that encodes gag, pol, tat, rev, env, and vpu.
[0014] In any of the above vectors or vaccine inserts, the encoded GM-CSF can be full-length human GM-CSF. In additional embodiments of the vectors and vaccine inserts, the sequence encoding GM-CSF can contain the sequence of: nucleotides 6633-7068 of SEQ ID NO: 7, nucleotides 6648-7082 of SEQ ID NO: 8, or nucleotides 7336-7770 of SEQ ID NO: 9. In any of the above viral vectors or polypeptide expression sequence, the encoded GM-CSF can be a truncated human GM-CSF or a mutant human GM-CSF that is capable of stimulating macrophage differentiation and proliferation, or activating polypeptide presenting cells.
[0015] The invention further provides methods of manufacturing a medicament for inducing an immune response in a subject using any of the above described vectors
[0016] By the term “natural variant” is meant a sequence that is naturally found in a subject or a virus. For example, human genes often contain single nucleotide polymorphisms that are present in certain individuals within a population. Viruses often acquire spontaneous mutations in their nucleic acid after serial passage in vitro or upon replication in an infected subject. Mutations within HIV sequences may confer resistance to drug treatment or alter the rate of infection or replication of the virus in a subject. Several natural variant sequences of HIV clades are known in the art (see, for example, the Los Alamos DNA Database website). By the term “mutant” is meant at least one (e.g., at least two, three, four, five, six, seven, eight, nine, ten, 100 or more) amino acid or nucleotide change in a sequence when compared to a wild type or predominant polypeptide or nucleotide sequence. A mutation may occur naturally in a cell or may be introduced by molecular biology techniques into a target sequence. The term mutant can include one or more (e.g., two, three, four, five, six, seven, eight, nine, or ten) amino acid or nucleotide deletions, additions, or substitutions.
[0017] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 . Schematic of a portion of a recombinant MVA virus. The MVA vaccine expresses gag-pol sequences in deletion III and env sequences in deletion II of MVA. Transcriptional control elements are shaded. For the MVA virus, transcription is under the control of the PmH5 early/late promoter. The MVA encodes an envelope glycoprotein that has been truncated for 146 amino acids at the C-terminus of its gp41 subunit. Xs, indicate inactivating point mutations in reverse transcriptase.
[0019] FIG. 2 . Schematic of HIV polypeptides encoded by certain recombinant MVA virus. Point mutations and deletions in reverse transcriptase and packaging sequences in gag are indicated.
[0020] FIG. 3 is the nucleotide sequence encoding Env in MVA 65 A/G.
[0021] FIG. 4 is the nucleotide sequence encoding Gag/Pol in MVA 65 A/G.
[0022] FIG. 5 is the nucleotide sequence encoding Env in MVA 62 B.
[0023] FIG. 6 is the nucleotide sequence encoding Gag/Pol in MVA 62 B.
[0024] FIG. 7 is the nucleotide sequence encoding Env in MVA 71 C.
[0025] FIG. 8 is the nucleotide sequence encoding Gag/Pol in MVA 71 C.
DETAILED DESCRIPTION
[0026] This invention encompasses viral vectors each of which include one or more nucleic acid sequences that encode one or more polypeptides, e.g., polypeptides that elicit (e.g., that induce or enhance) an immune response against the pathogen from which the polypeptide was obtained or derived. Generally, the MVA will have polypeptide and/or GM-CSF encoding sequences inserted into Deletion II and Deletion III of MVA or between modified insertion sites or between essential genes or genes that affect virus replication to prevent overgrowth of MVAs that have lost inserts (Wyatt et al., J. Virol. 83: 7176-7184) described in more detail in US, application Ser. No. 12/377,847 filed 17 Feb. 2009. In order to suppress expression of polypeptides during manufacture, miRNA target sequences are preferably inserted into the 3′ untranslated region of each transcript.
[0027] The invention features the nucleic acid sequences disclosed herein, analogs thereof, and compositions containing those nucleic acids (whether vector plus polypeptide expression sequence or polypeptide expression sequence only; e.g., physiologically acceptable solutions, which may include carriers or other reagents used to deliver MVA to cells. The analogs can be sequences that are not identical to those disclosed herein, but that include the same or similar mutations (e.g., the same point mutation or a similar point mutation) at positions analogous to those included in the present sequences (e.g., any of the JS, IC, or IN sequences disclosed herein). A given residue or domain can be identified in various HIV clades even though it does not appear at precisely the same numerical position. The analogs can also be sequences that include mutations that, while distinct from those described herein, similarly inactivate an HIV gene product. For example, a gene that is truncated to a greater or lesser extent than one of the genes described here, but that is similarly inactivated (e.g., that loses a particular enzymatic activity) is within the scope of the present invention.
[0028] The pathogens and antigens, which are described in more detail in US-2003-0175292-A1 and US-2008-0193483-A1 (incorporated by reference), include human immunodeficiency viruses of any Glade (e.g. from any known Glade or from any isolate (e.g., Glade A, AG, B, C, D, E, F, G, H, I, J, K, or L)). Additional HIV sequences and mutant sequences are known in the art (e.g., the HIV Sequence Database in Los Alamos and the HIV RT/Protease Sequence Database in Stanford). Moreover, one or more of the inserts within any construct can be mutated to decrease their natural biological activity (and thereby increase their safety) in humans. At least one of the two or more sequences can be mutant or mutated so as to limit the encapsidation of viral RNA (preferably, the mutation(s) limit encapsidation appreciably). One can introduce mutations and determine their effect (on, for example, expression or immunogenicity) using techniques known in the art; polypeptides that remain well expressed (e.g., polypeptides that are expressed about as well as or better than their wild type counterparts), but are less biologically active than their wild type counterparts, are within the scope of the invention. Techniques are also available for assessing the immune response.
[0029] US-2008-0193483-A1 provides a detailed description of three different MVA vectors, MVA 65A/G, MVA 62B and MVA 71C, expressing HIV polypeptides. Each of these can be modified by insertion of miRNA target sequences. Each of the three vectors encodes Env and Gag/Pol with safety mutations. Sequences encoding these polypeptides are depicted in FIGS. 3-8 .
[0030] The mutant constructs (e.g., a vaccine insert) can include sequences encoding one or more of the substitution mutants described herein (see, e.g. the Examples) or an analogous mutation in another HIV Glade. In addition to, or alternatively, HIV polypeptides can be rendered less active by deleting part of the gene sequences that encode them. Thus, the compositions of the invention can include constructs that encode polypeptides that, while capable of eliciting an immune response, are mutant (whether encoding a protein of a different length or content than a corresponding wild type sequence) and thereby less able to carry out their normal biological function when expressed in a patient. As noted above, expression, immunogenicity, and activity can be assessed using standard techniques in molecular biology and immunology.
[0031] The GM-CSF sequence included in the vectors and the vaccine inserts may be a full-length human GM-CSF (SEQ ID NO: 10) or may be a polypeptide that includes a sequence that is at least 95% identical to GM-CSF (SEQ ID NO: 10) and has one or more (e.g., two or three) biological activities of GM-CSF (e.g., capable of stimulating macrophage differentiation and proliferation, or activating polypeptide presenting cells). The GM-CSF may include one or more mutations (e.g., one or more (e.g., at least two, three, four, five, or six) amino acid substitutions, deletions, or additions)). Desirably, any mutant GM-CSF proteins also have one or more (e.g., two or three) biological activities of GM-CSF (as described above). Assays for the measurement of the biological activity of GM-CSF proteins are known in the art (see, e.g., U.S. Pat. No. 7,371,370; incorporated herein by reference in its entirety).
[0032] Particular polypeptides include the following. A polypeptide comprising a wild type or mutant gag sequence (e.g., a gag sequence having a mutation in one or more of the sequences encoding a zinc finger at one or more of the cysteine residues at positions 392, 395, 413, or 416 to another residue (e.g., serine) or the mutation can change one or more of the cysteine residues at positions 390, 393, 411, or 414 to another residue (e.g., serine). For HIV Pol it may be wild type or mutant Pol. The sequence can be mutated by deleting or replacing one or more nucleic acids, and those deletions or substitutions can result in a Pol gene product that has less enzymatic activity than its wild type counterpart (e.g., less integrase activity, less reverse transcriptase (RT) activity, or less protease activity). For example, one can inhibit RT by inactivating the polymerase's active site or by ablating strand transfer activity. Alternatively, or in addition, one can inhibit the polymerase's RNase H activity.
[0033] Where a polypeptide includes some or all of the pol sequence, another portion of the pol sequence that can optionally be altered is the sequence encoding the protease activity (regardless of whether or not sequences affecting other enzymatic activities of Pol have been altered). Where the composition includes either a viral vector with a polypeptide expression sequence or a polypeptide expression sequence alone, that polypeptide expression sequence can encode one or more of wild type or mutant Env, Tat, Rev, Nef, Vif, Vpr, or Vpu. With respect to Env, one or more mutations can be present. For example, one or more amino acids can be deleted from the gp120 surface and/or gp41 transmembrane cleavage products. With respect to Gag, one or more amino acids can be deleted from one or more of: the matrix protein (p17), the capsid protein (p24), the nucleocapsid protein (p7) and the C-terminal peptide (p6). For example, amino acids in one or more of these regions can be deleted. With respect to Pol, one or more amino acids can be deleted from the protease protein (p10), the reverse transcriptase protein (p66/p51), or the integrase protein (p32).
[0034] More specifically, the compositions of the invention can include a viral vector that encodes: (a) a Gag protein in which one or more of the zinc fingers has been inactivated to limit the packaging of viral RNA; (b) a Pol protein in which (i) the integrase activity has been inhibited by deletion of some or all of the pol sequence and (ii) the polymerase, strand transfer, and/or RNase H activity of reverse transcriptase has been inhibited by one or more point mutations within the pol sequence; and (c) Env, Tat, Rev, and Vpu, with or without mutations. In this embodiment, as in others, the encoded proteins can be obtained or derived from a subtype A, B or C HIV (e.g., HIV-1) or recombinant forms thereof. Where the compositions include non-identical vectors, the sequence in each type of vector can be from a different HIV Glade (or subtype or recombinant form thereof). For example, the invention features compositions that include plasmid vectors encoding the polypeptides just described (Gag-Pol, Env etc.), where some of the plasmids include polypeptides that are obtained from, or derived from, one Glade and other plasmids include polypeptides that are obtained (or derived) from another Glade. Mixtures representing two, three, four, five, six, or more clades (including all clades) are within the scope of the invention.
[0035] The encoded proteins can also be those of, or those derived from, any of HIV clades (or subtypes) E, F, G, H, I, J, K or L or recombinant forms thereof. An HIV-1 classification system has been published by Los Alamos National Laboratory (HIV Sequence Compendium-2001, Kuiken et al, published by Theoretical Biology and Biophysics Group T-10, Los Alamos, N. Mex., (2001)), more recent HIV sequences are available on the Los Alamos HIV sequence database website.
[0036] The compositions of the invention can also include a viral vector encoding: (a) a Gag protein in which one or both zinc fingers have been inactivated; (b) a Pol protein in which (i) the integrase activity has been inhibited by deletion of some or all of the pol sequence, (ii) the polymerase, strand transfer, and/or RNase H activity of reverse transcriptase has been inhibited by one or more point mutations within the pol sequence and (iii) the proteolytic activity of the protease has or has not been inhibited by one or more point mutations; and (c) Env, Tat, Rev, and Vpu, with or without mutations. As noted above, proteolytic activity can be inhibited by introducing a mutation at positions 1641-1643 of SEQ ID NO:8 or at an
[0037] Virus vaccine inserts of the present invention generate non-infectious VLPs (a term that can encompass true VLPs as well as aggregates of viral proteins) from a single DNA. This was achieved using the subgenomic splicing elements normally used by immunodeficiency viruses to express multiple gene products from a single viral RNA. The subgenomic splicing patterns are influenced by (i) splice sites and acceptors present in full length viral RNA, (ii) the Rev responsive element (RRE) and (iii) the Rev protein. The splice sites in retroviral RNAs use the canonical sequences for splice sites in eukaryotic RNAs. The RRE is an approximately 200 by RNA structure that interacts with the Rev protein to allow transport of viral RNAs from the nucleus to the cytoplasm. In the absence of Rev, the approximately 10 kb RNA of immunodeficiency virus mostly undergoes splicing to the mRNAs for the regulatory genes Tat, Rev, and Nef. These genes are encoded by exons present between RT and Env and at the 3′ end of the genome. In the presence of Rev, the singly spliced mRNA for Env and the unspliced mRNA for Gag and Pol are expressed in addition to the multiply spliced mRNAs for Tat, Rev, and Nef.
[0038] The expression of non-infectious VLPs from a single DNA affords a number of advantages to an immunodeficiency virus vaccine. The expression of a number of proteins from a single DNA affords the vaccinated host the opportunity to respond to the breadth of T- and B-cell epitopes encompassed in these proteins. The expression of proteins containing multiple epitopes allows epitope presentation by diverse histocompatibility types. By using whole proteins, one offers hosts of different histocompatibility types the opportunity to raise broad-based T cell responses. This may be essential for the effective containment of immunodeficiency virus infections, whose high mutation rate supports ready escape from immune responses (Evans et al., Nat. Med. 5:1270-1276, 1999; Poignard et al., Immunity 10:431-438, 1999, Evans et al., 1995). In the context of the present vaccination scheme, just as in drug therapy, multi-epitope T cell responses that require multiple mutations for escape will provide better protection than single epitope T cell responses (which require only a single mutation for escape).
[0039] Preferably, the viral vectors featured in the compositions and methods of the present invention are highly attenuated. Several attenuated strains of vaccinia virus were developed to avoid undesired side effects of smallpox vaccination. The modified vaccinia Ankara (MVA) virus was generated by long-term serial passages of the Ankara strain of vaccinia virus on chicken embryo fibroblasts (CVA; see Mayr et al., Infection 3:6-14, 1975). The MVA virus is publicly available from the American Type Culture Collection (ATCC; No. VR-1508; Manassas, Va.). The desirable properties of the MVA strain have been demonstrated in clinical trials (Mayr et al., Zentralbl. Bakteriol. 167:375-390, 1978; Stickl et al., Dtsch. Med. Wschr. 99:2386-2392, 1974; see also, Sutter and Moss, Proc. Natl. Acad. Sci. U.S.A. 89:10847-10851, 1992). During these studies in over 120,000 humans, including high-risk patients, no side effects were associated with the use of MVA vaccine.
[0040] The MVA vectors can be prepared as follows. A DNA construct that contains a DNA sequence that encodes a foreign polypeptide (e.g., any of the HIV polypeptides described herein) and that is flanked by MVA DNA sequences adjacent to a naturally occurring deletion within the MVA genome (e.g., deletion III or other non-essential site(s); six major deletions of genomic DNA (designated deletions I, II, III, IV, V, and VI) totaling 31,000 base pairs have been identified (Meyer et al., J. Gen. Virol. 72:1031-1038, 1991)) or flanked by MVA sequences adjacent to modified deletions sites or essential genes for virus replication (see end for patent references) is introduced into cells infected with MVA under conditions that permit homologous recombination to occur. Once the DNA construct has been introduced into the eukaryotic cell and the foreign DNA has recombined with the viral DNA, the recombinant vaccinia virus can be isolated by methods known in the art (isolation can be facilitated by use of a detectable marker). The DNA constructed to be inserted can be linear or circular (e.g., a plasmid, linearized plasmid, gene, gene fragment, or modified HIV genome). The foreign DNA sequence is inserted between the sequences flanking the naturally occurring deletion, modifications of the naturally occurring deletions or essential genes for virus growth. For better expression of a DNA sequence, the sequence can include regulatory sequences (e.g., a promoter, such as the promoter of the vaccinia 11 kDa gene or the 7.5 kDa gene or a modified promoter such as mH5). The DNA construct can be introduced into MVA-infected cells by a variety of methods, including calcium phosphate-assisted transfection (Graham et al., Virol. 52:456-467, 1973 and Wigler et al., Cell 16:777-785, 1979), electroporation (Neumann et al., EMBO J. 1:841-845, 1982), microinjection (Graessmann et al., Meth. Enzymol. 101:482-492, 1983), by means of liposomes (Straubinger et al., Meth. Enzymol. 101:512-527, 1983), by means of spheroplasts (Schaffner, Proc. Natl. Acad. Sci. U.S.A. 77:2163-2167, 1980), or by other methods known in the art.
|
The present invention provides viral vectors, such as recombinant MVA vectors, that are capable of expressing one or more polypeptides, such as, e.g., HIV proteins or GM-CSF, in the cells of a human patient at relatively high levels and can also be produced in significant quantities in cultured cells. Also provided are methods for producing the viral vectors and pharmaceutical compositions containing them.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to International Patent Application No. PCT/US2012/063790, filed Nov. 7, 2012 and entitled “METHOD OF INCREASING THE PERFORMANCE OF CATIONIC FABRIC SOFTENERS” which claims priority to U.S. Provisional Application 61/558,551 filed Nov. 11, 2011 and entitled “METHOD OF INCREASING THE PERFORMANCE OF CATIONIC FABRIC SOFTENERS BY ADDITION OF QUATERNARY (METH)ACRYLIC POLYMERS”, which is incorporated herein.
FIELD OF THE INVENTION
[0002] The present invention relates to fabric softeners comprising cationic thickeners and in particular to a method of increasing the fabric softening efficacy of a fabric softener by incorporating a quaternary (meth)acrylic polymer. The present invention also relates to the use of a quaternary (meth)acrylic polymer as a fabric softening active.
BACKGROUND OF THE INVENTION
[0003] Liquid fabric treatment compositions suitable for fabric softening and static control during the laundry process are well known in the art and widespread in commercial success. These liquid fabric treatment compositions typically contain quaternary ammonium cationic surfactants (commonly referred to as quats, or quaternary fabric softeners) that provide fabric-softening and anti-static benefit during the laundry rinse cycle.
[0004] Viscosities are important in formulating both concentrated/premium liquid fabric softeners having high levels of quaternary fabric softener and dilute/discount products having low levels of actives. For concentrated products, electrolytes such as calcium chloride have been used to control viscosity, however addition of up to about 2000 ppm CaCl 2 does nothing more than allow a few more percent active quaternary to be added to the formula. This is exemplified in U.S. Pat. No. 3,681,241 (Rudy at al.) wherein formulations comprising only up to about 12% active quaternary are possible. This is also exemplified in U.S. Pat. No. 4,772,404 (Fox et al.) where formulas having up to 15% quaternary blend (Varisoft 222LM and Adogen 442 in a critical ratio) are stabilized with triethanolammonium citrate and 0.09% calcium chloride. Another approach has been to combine fabric “softener” and fabric “substantive” agents. For example U.S. Pat. No. 4,155,855 (Goffinet, et al.), U.S. Pat. No. 4,157,307 (Jaeger et al.) and U.S. Pat. No. 4,855,072 (Trinh et al), describe combination of fabric softening and fabric substantive agents, wherein the fabric substantive agent is a quaternary imidazolinium salt. However, even though the compositions may contain as much as 25-50% of a blend of these two quaternary materials, only the softening agent (a conventional quaternary) appears to confer the softening and antistatic benefit to the fabric.
[0005] Other methods to stabilize concentrated fabric softener compositions having high levels of quaternary actives utilize additional surfactants, solvents or polymers. For example, as described in U.S. Pat. No. 4,326,965 (Lips et al.), stable formulas with up to 40% active quaternary are possible when incorporating 4-25% polymer having MW greater than 400. U.S. Pat. No. 4,556,502 (Blackmore et al.) describes concentrated fabric softener formulations with up to 40% active quaternary if stabilized with greater than 0.5% amphoteric surfactants and 5-30% alkanol solvent. Lastly, U.S. Pat. No. 4,233,164 (Davis) describes stabilization of 2-11% quaternary active formulations through the use of 1-5% nonionic surfactant.
[0006] Cost-reduced liquid fabric softeners may comprise lower levels of quaternary surfactant, for example less than about 10 wt. % actives and even less than about 5 wt. % actives. However, these liquids often lack any viscosity and may appear “cheap” to the consumer. Thickeners have been used to give a more “premium” appearance to dilute liquid fabric softeners having low quaternary surfactant active levels. However, some thickeners such as cationic gums and starches are not expected to change the performance of the product, but instead only expected to add cost. Examples of the use of cationic thickeners in fabric softeners is known and may be found in U.S. Pat. No. 6,949,500 (Salesses, et al.) and U.S. Pat. No. 6,514,931 (Grainger, et al.) and U.S. Patent Application Publication 2006/0252668 (Frankenbach, et al.).
[0007] Accordingly, additional development of liquid fabric softeners is warranted, ideally with research into thickeners that may bring other benefits to liquid fabric softeners other than viscosity control.
SUMMARY OF THE INVENTION
[0008] It has now been surprisingly found that parity fabric softening performance is possible in a cost-reduced fabric softener by the addition of a cationic rheology modifier having quaternary structure. The cationic thickener provides an unexpected fabric softening effect and is much less expensive than quaternary surfactant compounds such as the ester quats typically used as the active softener in liquid fabric softeners.
[0009] In a preferred embodiment of the present invention, less than 0.5 wt. % actives cationic polymer or co-polymer derived from at least one quaternized (meth)acrylic monomer boosts the softening performance of a low-actives quat-based fabric softener.
[0010] In another preferred embodiment of the present invention, as little as less than 0.5 wt. % actives poly[{2-(methacryloyloxy)ethyl}trimethylammonium chloride] homopolymer boosts the performance of a liquid fabric softener having only 8.0 wt. % actives ester quat softener back up to the softening performance of a liquid composition having 10 wt. % actives quaternary softener and no cationic thickener.
[0011] In another preferred embodiment of the present invention, as little as less than 0.5 wt. % actives poly[{3-(methacryloyloxy)propyl}trimethylammonium chloride] homopolymer boosts the performance of a liquid fabric softener having only 8.0 wt. % actives ester quat softener back up to the softening performance of a liquid composition having 10 wt. % actives quaternary softener and no cationic thickener.
[0012] In yet another preferred embodiment of the present invention, various quaternized (meth)acrylic polymers, including acylates, methacrylates, acrylamides, and methacrylamides, having quaternized appendages, are used as fabric softening actives.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a 3D surface plot of fabric softening against cationic thickener and esterquat.
[0014] FIG. 2 is also a 3D surface plot of fabric softening against cationic thickener and esterquat.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The following description is of exemplary embodiments only and is not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.
[0016] That said, the present invention relates to a method of increasing the performance of a quat-based liquid fabric softener through the addition of a quaternized poly-(meth)acrylic polymer thickener.
[0017] The present invention also relates to fabric softener compositions that minimally comprise quaternary surfactants, a cationic (meth)acrylic polymer thickener, and water, and that optionally comprise antifoams, preservatives, dyes and fragrances.
[0018] Quaternary Compounds Useful for Fabric Softening
[0019] In accordance with various embodiments of the present invention, the liquid fabric softener compositions comprise a quaternary ammonium cationic surfactant. For brevity, these cationic materials will be referred to as quaternary surfactants with the understanding that they are quaternized nitrogen species (i.e., cationic) and necessarily have an anionic counterion. In this regard, a variety of quaternary surfactants may be utilized. However, acyclic quaternary surfactants are preferred for fabric softener actives. For example, useful quaternary synthetic surfactants that are acyclic include linear alkyl, branched alkyl, hydroxyalkyl, oleylalkyl, acyloxyalkyl, diamidoamine, or diester quaternary ammonium compounds. The preferred quaternary surfactants for use in the present invention are the ester and diester quaternary surfactants and the diamidoamine quaternary blends. Cyclic quaternary materials such as the imidazolines are less preferred in the present invention but remain useful as softener actives. The quaternary surfactant actives in accordance with a preferred embodiment is at a level from about 1% to about 40% by weight of the fabric softener composition, and preferably from about 1% to about 10%, based on the total weight of the composition.
[0020] Examples of acyclic quaternary surfactant fabric-softening components useful in the present invention are shown by the general formulas (I) and (II):
[0000]
[0000] wherein for general formula (I), R and R 1 are individually selected from the group consisting of C 1 -C 4 alkyl, benzyl, and —(C 2 H 4 O) x Z where x has a value from 1 to 20 and Z is hydrogen or C 1 -C 3 alkyl; R 2 and R 3 are each a C 8 -C 30 alkyl or R 2 is a C 8 -C 30 alkyl and R 3 is selected from the group consisting of C 1 -C 5 alkyl, benzyl, and —(C 2 H 4 O) x —H where x has a value from 2 to 5; and where X − represents an anion selected from the group consisting of halides, methyl sulfate, ethyl sulfate, methyl phosphate, acetate, nitrate or phosphate ion and mixtures thereof. Specific examples of quaternary surfactants described within the general formula (I) include alkyltrimethylammonium compounds, dialkyldimethylammonium compounds and trialkylmethylammonium compounds including but not limited to, tallow trimethyl ammonium chloride, ditallow dimethyl ammonium chloride, ditallow dimethyl ammonium methyl sulfate, dihexadecyl dimethyl ammonium chloride, di-(hydrogenated tallow) dimethyl ammonium chloride, dioctadecyl dimethyl ammonium chloride, dieicosyl dimethyl ammonium chloride, didocosyl dimethyl ammonium chloride, di-(hydrogenated tallow) dimethyl ammonium methyl sulfate, dihexadecyl dimethyl ammonium acetate, ditallow dipropyl ammonium phosphate, ditallow dimethyl ammonium nitrate, di-(coconut-alkyl)dimethyl ammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, distearyldimethylammonium chloride, lauryldimethylammonium chloride, and tricetylmethylammonium chloride, along with other quaternary compounds such as trihydroxyethylmethylammonium methosulfate, lauryldimethylbenzylammonium chloride, and the like.
[0021] Quaternary surfactants of the formula (II) are known as ester quats. Ester quats are notable for excellent biodegradability. In the formula (II), R 4 represents an aliphatic alkyl radical of 12 to 22 carbon atoms which has 0, 1, 2 or 3 double bonds; R 5 represents H, OH or O—(CO)R 7 , R 6 represents H, OH or O—(CO)R 8 independently of R 5 , with R 7 and R 8 each being independently an aliphatic alkyl radical of 12 to 22 carbon atoms which has 0, 1, 2 or 3 double bonds. m, n and p are each independently 1, 2 or 3. X − may be a halide, methyl sulfate, ethyl sulfate, methyl phosphate, nitrate, acetate or phosphate ion and also mixtures thereof. Useful are compounds wherein R 5 is O—(CO)R 7 and R 4 and R 7 are alkyl radicals having 16 to 18 carbon atoms, particularly compounds wherein R 6 also represents OH. Examples of compounds of the formula (II) include methyl-N-(2-hydroxyethyl)-N,N-di-(tallow acyloxyethyl)ammonium methyl sulfate, bis-(palmitoyl)-ethylhydroxyethyl methyl ammonium methyl sulfate or methyl-N,N-bis(acyloxyethyl)-N-(2-hydroxyethyl)ammonium methyl sulfate. In quaternary surfactants of the formula (II) which comprise unsaturated alkyl chains, preference is given to acyl groups whose corresponding fatty acids have an iodine number between 5 and 80, preferably between 10 and 60 and especially between 15 and 45 and also a cis/trans isomer ratio (in % by weight) of greater than 30:70, preferably greater than 50:50 and especially greater than 70:30. Commercially available examples are the methylhydroxyalkyldialkoyloxyalkylammonium methyl sulfates marketed by Stepan under the Stepantex® brand or the Cognis products appearing under Dehyquart® or the Evonik products appearing under Rewoquat®. Further ester quats of use in the present invention have the formulas; [(CH 3 ) 2 N + (CH 2 CH 2 OC(O)—R) 2 ]X − or [(HOCH 2 CH 2 )(CH 3 )N + (CH 2 CH 2 OC(O)—R) 2 ]X − , where R=linear saturated or unsaturated alkyl radical of 11 to 19 and preferably 13 to 17 carbon atoms. In a particularly preferred embodiment the fatty acid residues are tallow fatty acid residues. X − represents either a halide, for example chloride or bromide, methyl phosphate, ethyl phosphate, methyl sulfate, ethyl sulfate, acetate, nitrate, phosphate and also mixtures thereof.
[0022] Further useful acyclic quaternary ammonium fabric-softening agents include the diester quats of the formula (III), obtainable under the name Rewoquat® W 222 LM or CR 3099, which provide stability and color protection as well as softness:
[0000]
[0023] Wherein R 21 and R 22 each independently represent an aliphatic radical of 12 to 22 carbon atoms which has 0, 1, 2 or 3 double bonds.
[0024] It is likewise preferable to use amidoamine quaternary surfactants of the formula (IV):
[0000]
[0025] wherein R 17 may be an aliphatic alkyl radical having 12 to 22 carbon atoms with 0, 1, 2 or 3 double bonds, s can assume values between 0 and 5, R 18 and R 19 are, independently of one another, each H, C 1-4 -alkyl or hydroxyalkyl. Preferred compounds are fatty acid amidoamines such as stearylamidopropyldimethylamine obtainable under the name Tego Amid® S18, or the 3-tallowamidopropyltrimethylammonium methyl sulfate obtainable under the name Stepantex® X 9124, which are characterized not only by a good conditioning effect, but also by color-transfer-inhibiting effect and in particular by their good biodegradability. Particular preference is given to alkylated quaternary ammonium compounds in which at least one alkyl chain is interrupted by an ester group and/or amido group, in particular N-methyl-N-(2-hydroxyethyl)-N,N-(ditallowacyloxyethyl)ammonium methyl sulfate and/or N-methyl-N-(2-hydroxyethyl)-N,N-(palmitoyloxyethyl)ammonium methyl sulfate.
[0026] In preferred embodiments, the present inventive liquid fabric softener compositions comprise Rewoquat® WE-18 (from Evonik), Incrosoft® T-90 from Croda, any of the Stepantex® brand diester quats from Stepan, or any of the Accosoft® diamidoamine quats from Stepan, or mixtures thereof, as the quaternary surfactants, preferably present to achieve a total actives level of from about 1% to about 40 wt. %, and more preferably from 1 wt. % to about 10 wt. %, by weight based on the entire composition.
[0027] Cationic Thickener
[0028] The cationic thickeners for use in the present invention are quaternary (meth)acrylic polymers having the general structure (V):
[0000]
[0000] wherein;
R 4 denotes H or CH 3 ;
Y denotes O or NH;
Z denotes: a linear alkyl chain of methylene units (CH 2 ), where x is an integer from 2 to 18; a substituted alkyl chain from 2 to 18 carbons in length having at least one hydroxyl group anywhere along the chain length; a benzene ring wherein the Y and the N substituents attach to the intervening benzene ring in a para relationship; or, a branched alkyl chain having a total number of carbons atoms from 2 to 18 carbon atoms; R 1 , R 2 , and R 3 are, independently, —CH 3 , —CH 2 —C 6 H 5 , —C 2 H 5 , -n-C 6 H 13 , -n-C 10 H 21 , -naphthalenyl, -benzofuranyl, or —CH 2 —C 6 H 4 —CH 2 —O—C 6 H 4 —CHO;
X denotes an anion chosen from the group consisting of halides (Cl, Br, I), sulfates (½SO 4 , HSO 4 ), methosulfate (MeOSO 3 ), trifluoromethane sulfonate (triflate, or “Tf”), tetrafluoroborate (BF 4 ), carbonates, bicarbonates, and mixtures thereof; and n (degree of polymerization) may be between several hundred to about 100 million.
[0029] Examples of polymers fitting this general structure (V), and hence useful in the present inventive composition and method, will be discussed below. It's important to note that the polymers for use in the present invention may be homopolymers and/or co-polymers. If the quaternized polymers used herein are co-polymers, the polymer structure may be random or block, with randomly interspersed nonionic monomers or blocks of nonionic oligomers. That is, the quaternary (meth)acrylic structure (V) may be only an oligomeric subunit of a co-polymer that also incorporates nonionic monomers and/or oligomers. Useful polymers are discussed in W. Jaeger, et al., Progress in Polymer Science, 35 (2010), 511-577, page 524 of the article, for example the polymers that the authors denote as 54a-h, 54k-m, 55a-f, 56, 57a-c, and 58, along with each of the co-polymers discussed in sections 3.1.3.2 and 3.2 of the article. The polymers and co-polymers disclosed in the Jaeger publication are incorporated herein by reference. Additional discussion of these useful polymers and other useful polymers for the present invention, may be found in U.S. Pat. No. 7,901,697 (Banetti, et al.), U.S. Pat. No. 7,491,753 (Krishnan), U.S. Pat. No. 6,329,483 (Schade, et al.), U.S. Pat. No. 5,608,021 (Uchiyama, et al.), and U.S. Pat. No. 5,169,540 (Fillipo, et al.), each incorporated herein by reference.
[0030] As understood in the chemical arts, the term (meth)acrylic is meant to include all acrylate, acrylamide, methacrylate, and methacrylamide substances, which is why the general structure (V) above features variable Y and R 4 groups and defines them so as to incorporate each of the acrylate, acrylamide, methacrylate, and methacrylamide polymers. “Quaternized” is the term given to a compound having a nitrogen atom with four (4) appendages and therefore a permanent positive charge. Consequently, there is a negatively charged counter-ion associated with each quaternized nitrogen atom in the cationic polymer. Synthesis of such quaternized (meth)acrylic polymers is found in the literature and includes, amongst other routes, both the polymerization of pre-quaternized monomers and the quaternization of polymers having appending tri-substituted amino groups with a reactant such as methyl chloride or benzyl chloride.
[0031] Preferred quaternary (meth)acrylic polymers for use in the present fabric softener composition include, but are not limited to poly[{2-(methacryloyloxy)ethyl}trimethylammonium chloride], poly[{2-(acryloyloxy)ethyl}trimethylammonium chloride], poly[{3-(methacryloyloxy)propyl}trimethylammonium chloride], poly[{3-(acryloyloxy)propyl}trimethylammonium chloride], poly[{2-(methacrylamido)ethyl}trimethylammonium chloride], poly[{2-(acrylamido)ethyl}trimethylammonium chloride], poly[{3-(methacrylamido)propyl}trimethylammonium chloride], and poly[{3-(acrylamido)propyl}trimethylammonium chloride], and mixtures thereof, each as homopolymers or as block or random co-polymers with various nonionic monomers. Such polymers are available commercially as Polygel® K-200 from 3V Sigma, Rheovis® CDE, CDP, and CSP from CIBA-BASF, and as Zetag™ 7109 from CIBA-BASF, amongst others. The quaternized (meth)acrylic polymers are incorporated in the liquid fabric softener at from about 0.01 wt. % to about 2 wt. % actives, based on the total weight of the composition. Preferably the cationic polymer is used at a level of from about 0.01 wt. % to about 0.5 wt. %. These quaternary (meth)acrylic polymers give an unexpected fabric softening effect and provide a way to cost-optimize liquid fabric softener products by reducing the level of quaternary surfactant and making up for the performance loss by the addition of the polymer. This unexpected benefit of fabric softening allow the use of these quaternary (meth)acrylic polymers as fabric softener actives.
[0032] Unsuitable cationic polymers include cationic guar polymers, cationic cellulose derivatives, cationic starches and cationic chitosan derivatives because they do not comprise structural similarity to the quaternary surfactant fabric softeners and are thus not expected to possess dual functionality of fabric softener and rheology modifier.
[0033] Optional Ingredients
[0034] Inorganic Stabilizers
[0035] The present invention may comprise one or more inorganic stabilizers. Such materials include, but are not limited to, calcium chloride and various borates. These inorganic materials are incorporated at from about 0.001 wt. % up to about 1 wt. %, based on the total weight of the composition.
[0036] Anti-Foam Agents
[0037] Antifoam is an optional ingredient for the compositions of the present invention. Any silicone emulsion antifoam typically used for aqueous compositions finds use in the present invention. Most useful are the antifoam emulsions available from Dow Corning. The preferred silicone antifoam for use in the present invention is Dow Corning® 1430 Antifoam, although Dow Corning® AC-8016 Antifoam, Dow Corning® Q2-3302 Antifoam Compound, Dow Corning® Q2-3425 Antifoam Compound, Dow Corning® DSP Antifoam Emulsion, Dow Corning® BF20 PLUS Antifoam Emulsion, Dow Corning® 544 Antifoam Compound, Dow Corning® DB-310 Antifoam Compound, and Dow Corning® 1520 Silicone Antifoam along with any other similar industrial or food grade silicone defoamer find use in the present invention. These types of materials mentioned help reduce foaming in the rinse cycle of the laundry operation when incorporated in the fabric softener composition. Preferably the antifoam is present in the composition from about 0.0001% to about 0.01% by weight, based on the total weight of the composition.
[0038] Antimicrobial Agent
[0039] Examples of antimicrobial agents that find use in the present invention include glutaraldehyde, formaldehyde, 2-bromo-2-nitropropane-1,3-diol sold under the trade name Bronopol®, 5-chloro-2-methyl-4-isothiazoline-3-one and 2-methyl-4-isothiazoline-3-one sold under the trade name Kathon®, and mixtures thereof. The preferred level for the antimicrobial is from about 0.001% to about 0.1%, or at that level recommended by the supplier of the particular antimicrobial and/or suggested in the supplier technical literature as that level required for optimally preserving aqueous surfactant compositions from mold and bacterial growth. The preferred antimicrobial for use in the present invention is glutaraldehyde and is best when incorporated from about 0.01% to about 0.10%. Most preferred in the present invention is to use Ucarcide® 250 brand of 50% glutaraldehyde solution and to add it at 0.050% by weight, based on the entire composition, resulting in an active level of glutaraldehyde of about 0.025%.
[0040] Fragrances
[0041] Fragrance is an optional ingredient for the fabric softener compositions of the present invention. For consumer acceptance, product recognition and recall, and most importantly to impart substantive fragrance to the fabrics inside the laundry washing machine, a fragrance is preferably added to the liquid fabric softener compositions of the present invention. Depending on the strength of the fragrance and the character of the perfume notes, the preferred amount of fragrance is from about 0.01% to about 3% by weight, based on the entire composition. Some preferred fragrances include, but are not limited to, UN063503/00, UN063507/00, UN063506/00, UN063511/00, UN063505/00, and UN063513/00 from Givaudan Fragrances, and Fressia-497 (from International Flavors and Fragrances).
[0042] Dyes
[0043] Dyes are optional ingredients within the compositions of the present invention. Dyes may comprise pigments, or other colorants, chosen so that they are compatible with the acidic pH of the final composition and such that the color is not attracted to the fabric. For example, a preferred colorant for use in the present invention is Liquitint® Green FS (from Milliken), at from about 0.001% to about 0.01% by weight, based on the entire composition. Other dyes such as C.I. Pigment Green #7, C.I. Reactive Green #12, F D & C Green #3, C.I. Acid Blue #80, C.I. Acid Yellow #17, Liquitint® Red MX, F D & C Yellow #5, Liquitint® Violet LS, Fast Turquise GLL, Liquitint® Blue MC, or mixtures thereof are also useful in the compositions of the present invention.
[0044] TABLE 1 delineates non-limiting examples of fabric softening compositions of the present invention, wherein cationic thickeners provide both fabric softening and thickening to the quaternary surfactant-based liquid fabric softener.
[0000]
TABLE 1
Exemplary Liquid Fabric Softener Compositions
Ingredients (in weight
Formulations
percent actives)
A
B
C
D
E
Quaternary surfactant 1
10.00
4.44
6.50
8.00
9.50
Cationic thickener 2
0
0.15
0.15
0.15
0.15
Inorganic stabilizers,
+
+
+
+
+
defoaming agent
Water, fragrance,
q.s.
q.s.
q.s.
q.s.
q.s.
dyes, preservatives
Total
100.0
100.0
100.0
100.0
100.0
Softening Score
4.78
4.45
4.48
5.06
5.17
Table Notes:
1 Rewoquat ® WE-18 from Evonic;
2 Polygel ® K-200 from 3V
METHODS, RESULTS AND DISCUSSION
[0045] To test softness, approximately 50 cotton washcloths are washed in a washing machine using a typical laundry detergent followed by the test liquid fabric softener in the rinse cycle. The laundered washcloths are subsequently dried in an electric dryer. 12 washcloths are stacked and placed on a table for panelists to feel and rate. The test is run in duplicate and blind. Panelists are asked to rank the level of softness on a scale from 1-9, with 1 being unacceptable and 9 being perfectly soft to the touch. The numbers are averaged and statistically analyzed. The data were also inputted into 3D surface plot DOE to probe for synergies between the fabric softening quaternary surfactant and the cationic quaternary (meth)acrylic polymer thickener.
[0046] From analysis of FIGS. 1 and 2 , it is evident that quaternary (meth)acrylic thickener functions as a fabric softener. Indeed, even the control formula A having 10% active quat softener and no thickener may be boosted in performance from softness scores of 4.78 up to a theoretical 6.1 by the addition of about 0.25 wt. % quaternary (meth)acrylic polymer. Lower active quat softeners, for example having only about 6.0 wt. % quaternary surfactant actives, may be boosted in performance by addition of only about 0.35 wt. % quaternary (meth)acrylic polymer. As can be seen in the 3D surface plots, it is possible to formulate a cost-reduced liquid fabric softener having only 6.0 wt. % active esterquat and only about 0.35 wt. % actives quaternary (meth)acrylic polymer yet still have softness scores greater than the scores possible with 10 wt. % quaternary surfactant actives and no quaternary (meth)acrylic polymer.
[0047] I have thus demonstrated that certain quaternary (meth)acrylic polymers not only function as fabric softeners but actually boost softness performance to such an extent that synergy between the fabric softening quat and the cationic polymer is suggested. Certain quaternary (meth)acrylic polymers may therefore be used as fabric softeners, may be used to boost the performance of low-actives quaternary surfactant-based fabric softeners, all while providing the expected benefit of thickening.
|
The present invention is method of boosting the performance of a cost-reduced liquid fabric softener comprising a quaternary surfactant fabric softener by adding a quaternary (meth)acrylic polymer that functions dually as a fabric softening active and a rheology modifier. In particular, poly[{2-(methacryloyloxy)ethyl}trimethylammonium chloride], poly[{2-(acryloyloxy)ethyl}trimethylammonium chloride], poly[{3-(methacryloyloxy)propyl}trimethylammonium chloride], and poly[{3-(acryloyloxy)propyl}trimethylammonium chloride] provide synergistic fabric softening with quaternary surfactants to provide superior fabric softening scores from cost-optimized compositions.
| 3
|
DESCRIPTION
1. Technical Field
This invention relates to gas turbine engines and more particularly to a stator structure for supporting an outer air seal about an array of rotor blades in such an engine. The concepts of this invention were developed in the field of axial flow gas turbine engines and have application to stator structures in other fields.
2. Background Art
Axial flow gas turbine engines generally include a compression section, a combustion section and a turbine section. A rotor extends axially through the sections of the engine. A stator extends axially to circumscribe the rotor. An annular flow path for hot, working medium gases extends through the engine between rotor and the stator. As the gases are flowed through the engine, the gases are compressed in the compression section, burned with fuel in the combustion section and expanded through the turbine section to produce useful work.
The rotor in the turbine section has a rotor assembly for extracting useful work from the hot, pressurized gases. The rotor assembly includes a rotor disk and a plurality of rotor blades which extend outwardly across the working medium flow path.
The stator in the turbine section includes a segmented outer air seal which is positioned about the array of rotor blades to block the leakage of working medium gases over the tips of the blades. The stator has a stator structure, which includes an outer case, for radially supporting and positioning the outer air seal about the array of rotor blades. The outer air seal is spaced radially from the array of rotor blades leaving a clearance gap therebetween. The clearance gap is provided to avoid destructive interference between the rotor blades and outer air seal.
In modern engines, the clearance gap between the rotor blades and the outer air seal is modulated to minimize the clearance during various operating conditions of the engine. Examples of engines employing external constructions to modulate the tip clearance are shown in U.S. Pat. No. 4,019,320 issued to Redinger et al. entitled "External Gas Turbine Engine Cooling For Clearance Control" and U.S. Pat. No. 4,247,248 issued to Chaplin et al. entitled "Outer Air Seal Support Structure For a Gas Turbine Engine," the material in which is incorporated herein by reference. In Redinger and Chaplin, the diameter of the outer air seal about the array of rotor blades, and thus the clearance gap, is adjusted by selectively cooling a portion of the case.
As shown in Redinger and Chaplin, each outer air seal is provided with a stator support structure that includes an upstream support ring and a downstream support ring. The engine case has a circumferentially extending rail adjacent to the upstream support ring and a second circumferentially extending rail adjacent to the downstream support ring. Cooling air is impinged on the rails. As the cooling air carries heat away from the external rails, the external rails contract and force the internal support structure to a smaller diameter. The internal support structure is circumferentially slideable with respect to the outer case and the array of outer air seal segments to accommodate the large changes in diameter. Turning off the cooling air allows the rails to expand with a concomitant increase in the diameter of the internal support structure and the outer air seal.
As the clearance between the outer air seal and the rotor blade is changed, the upstream and downstream support rings must move by the same amount to avoid tilting from front to back of the outer air seal segments. For example, tilting of the segments might occur because of unexpected axial temperature gradient in the outer case between rails or as the upstream rail is unexpectedly cooled more than the downstream rail decreasing the clearance gap at the front of the seal with respect to the back. An unpredicted decrease in the clearance gap between the outer air seal and the rotor blade may cause a destructive interference between the rotor blade and the outer air seal with a corresponding decrease in the performance of the engine or even the loss of a rotor blade.
Tilting of the segments might occur at the downstream rail, for example, because of the unpredicted leakage of gases from the interior of the case to the exterior of the case through a flange at the rail. The unexpected leakage causes heating of the flange and an increase in the clearance at the back of the seal with respect to the front. A larger than expected gap between the rotor blade and the outer air seal may cause a decrease in the efficiency of the engine because of the increased leakage of working medium gases over the tips of the rotor blades.
The amount of cooling air required to cool the upstream rail and the downstream rail is also important. The cooling air that is impinged on the coolable rails is pressurized to an extent that enables the air to flow from spray bars to the rail. One source of pressurized cooling air is the compression section of the engine. As the working medium gases are passed through the fan section, a portion of the pressurized gases (air) are removed from the working medium flow path and ducted to spray bars. Because the cooling air is removed from the working medium flow path after energy is expended by the engine to pressurize the gases, it is desirable to reduce the amount of cooling air needed for clearance control.
Accordingly, scientists and engineers are searching for ways to decrease the need for pressurized cooling air and to avoid uneven movement of the outer air seal in the radial direction to avoid variations in the gap between the outer air seal and the rotor blade.
DISCLOSURE OF INVENTION
According to the present invention, a stator structure in a gas turbine engine having a coolable rail which extends about an outer case for positioning an outer air seal about an array of rotor blades includes an upstream support ring and a downstream support ring for the outer air seal which are attached to the outer case at an axial location adjacent to the coolable rail to cause the support rings to act together.
A primary feature of the present invention is a coolable rail which extends circumferentially about an outer case. Another feature is a segmented outer air seal. A feature is a segmented upstream support ring and a segmented downstream support ring. Each has a plurality of support segments. The plurality of upstream support segments and the plurality of downstream support segments slideably engage the outer case and extend from the outer case to the outer air seal. Another primary feature is a means for attaching the upstream and downstream support segments at an axial location which is adjacent to the coolable rail. In one detailed embodiment, one of the support rings is integral with an array of stator vanes. Rib and groove connections are used to join the ends of the array of outer air seals to the platforms of the array of stator vanes.
A primary advantage of the present invention is the engine efficiency which results from blocking the leakage of working medium gases over the tips of an array of rotor blades with a segmented outer air seal. The segmented outer air seal has upstream and downstream support rings which are moved by the same amount to avoid tilting of the segments from front to rear as the support rings and the outer air seal are moved inwardly and outwardly by a coolable rail. Another advantage of the present invention is the engine efficiency which results from the efficient use of cooling air by using a single coolable rail to position the upstream and downstream ends of an array of outer air seals. In one embodiment, an advantage of the present invention is the reduction in the number of parts in the engine by employing a single rail to position the outer air seal and by supporting the end of an array of outer air seals and the end of an array of stator vanes with the same support ring.
The foregoing features and advantages of the present invention will become more apparent in the light of the following detailed description of the best mode for carrying out the invention and in the accompanying drawing.
DESCRIPTION OF DRAWINGS
FIG. 1 is a side elevation view of a turbofan engine with a portion of the fan case broken away to show a cooling air duct.
FIG. 2 is a cross-sectional view of a portion of the turbine section of the engine.
FIG. 3 is an alternate embodiment of the turbine section shown in FIG. 2.
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a turbofan, axial flow gas turbine engine embodiment of the invention. The engine includes a fan section 10, a compression section 12, a combustion section 14 and a turbine section 16. The engine has an axis of rotation A and an annular flow path 18 for working medium gases which extends axially through these sections of the engine. A coolable outer case 20 extends circumferentially about the working medium flow path. The outer case in the turbine section of the engine has at least one coolable rail 22 integral with the outer case which extends circumferentially about the exterior of the outer case. A means for impinging cooling air on the rails, such as a plurality of spray bars 24, extends circumferentially about the exterior of the case. A multiplicity of cooling air holes 26 places the interior of each bar in flow communication with an associated rail. A duct 28 for cooling air extends rearwardly from the fan section of the engine and is in flow communication with the spray bars to provide a source of cooling air to the coolable rails.
FIG. 2 is a cross-sectional view of a portion of the turbine section 16 of the engine showing part of the outer case 20 and the annular flow path 18 for hot working medium gases. An array of stator vanes, as represented by the single stator vane 30, extends radially inwardly from the outer case across the working medium flow path. Each stator vane has an upstream foot 32 which slideably engages the outer case and a downstream foot 34. The downstream foot is attached to the outer case by a suitable means, such as the nut and bolt combination 35.
The turbine section 16 includes a first array of rotor blades, as represented by the single rotor blade 38. The first rotor blade 38 terminates in a tip 40 which is axially oriented, that is, extends in a generally axial direction. A second array of rotor blades, as represented by the single rotor blade 42, is spaced radially from the first array of rotor blades to form alternate arrays of rotor blades and stator vanes. The second rotor blade terminates in a tip 44 which is axially oriented.
The first rotor blade 38 and the second rotor blade 42 extend outwardly across the annular flow path 18 into proximity with the coolable outer case 20. A first outer air seal 46 extends circumferentially about the first array of rotor blades and is spaced radially from the rotor blades leaving a radial gap G therebetween. The outer air seal is formed of an array of arcuate seal segments, as represented by the single seal segment 48. A stator structure 50 for radially supporting and positioning the array of outer seal segments engages the segments. The stator structure includes an upstream support ring 52 and a downstream support ring 54. The downstream support ring has a frustoconical shape and is formed of a plurality of downstream support segments, as represented by the single downstream support segment 56. Each downstream support segment engages the outer air seal and is circumferentially slideable with respect to the outer air seal. Each downstream support segment extends from the outer air seal to the outer case 20 and slideably engages the outer case. In the embodiment shown, the center of the downstream support segment is free to move circumferentially. Alternatively, a center bolt (not shown) in the downstream support segment might prevent the center portion of the downstream support segment from shifting circumferentially with respect to the case. Nevertheless, the ends of each segment are free to move circumferentially and the support segment is circumferentially slideable with respect to the outer air seal and the outer case.
The upstream support ring 52 is frustoconical in shape and is formed of a plurality of upstream support segments, as represented by the single upstream support segment 58. Each upstream support segment is trapped by the outer case 20 and an associated downstream support segment 56. Each upstream support segment slideably engages the outer case and extends from the outer case to the outer air seal to engage the outer air seal. Each upstream support segment is circumferentially slideable with respect to the outer air seal 46.
An inner flange 62 is provided. The inner flange is an example of a means for attaching the plurality of upstream support segments 58 and the plurality of downstream support segments 56 to the outer case 20. The flange attaches the segments to the outer case at a first axial location A 1 . The flange includes a shoulder 64 and a hook 66. Each upstream support segment is trapped between the flange on the case and an associated downstream support segment 56. The downstream support segment is adapted by a hook 68 to slideably engage in the circumferential direction the circumferentially extending hook 66 on the outer case. In the embodiment shown, the flange 62 is integral with the outer case. Other satisfactory constructions are contemplated which might employ a means for attaching the upstream and downstream support segments which is not integral with the outer case (such as a second set of support rings) and yet permits circumferential movement between the upstream and downstream support rings and the outer case.
A coolable rail 22 having an axial width W extends circumferentially about the exterior of the outer case at a location A 2 which is axially adjacent to the first axial location A 1 . The term "adjacent" means that the axial location of the flange lies within a distance D which is less than the width W of the rail. In the embodiment shown, the axial location A 2 of the rail 22 and the first axial location A 1 overlap.
The second array of rotor blades 42 extends outwardly across the annular flow path 18 into proximity with the coolable outer case 20. A second outer air seal 72 extends circumferentially about the array of rotor blades and is spaced radially from the rotor blades by a gap G 2 . The second outer air seal is formed of an array of arcuate seal segments 74. A stator structure 76 of the same type as the stator structure 50 radially supports and positions the array of arcuate segments about the array of rotor blades. The stator structure includes an upstream support ring 78 and a downstream support ring 80. The upstream support ring is frustoconical in shape and is formed of a plurality of circumferentially extending segments, as represented by the single segment 82. The downstream support ring is frustoconical in shape and is formed of a plurality of downstream support segments, as represented by the single downstream support segment 84. A nut and bolt combination 86, or other suitable means, are employed to make each upstream support segment integral with an associated downstream support segment to form a pair of associated segments 90. Each pair of segments has a circumferentially extending hook 92. A hook 94 at a first axial location A3 on the outer case provides a means for attaching the support segments to the outer case and adapts the case to slideably engage in the circumferential direction the circumferentially extending hook of the pair of support segments. A coolable rail 22 having a width W extends circumferentially about the exterior of the outercase at a location A4 which is axially adjacent to the first axial location A3.
FIG. 3 shows a stator structure 96 which is an alternate embodiment of the stator structure 76 shown in FIG. 2. The stator structure includes an array of stator vanes 98 having an upstream end 100 and a downstream end 102. An outer air seal 104 is formed of a plurality of arcuate seal segments 106. This embodiment of the stator structure differs from the stator structure 76 in that the plurality of upstream support segments 108 extend from the outer case to the downstream end of the array of stator vanes to support the array of stator vanes. In the embodiment shown, each segment 108 of the plurality of upstream support segments is integral with at least one stator vane 98. Each arcuate seal segment is adapted to engage the downstream end of the stator vane with a rib and groove construction 110. In the embodiment shown, each arcuate seal segment has a rib 112. Each vane has a groove 114.
During operation of the gas turbine engine, hot working medium gases are flowed from the combustion section 14 to the turbine section. The hot, pressurized gases are expanded in the turbine section 16. As the gases are flowed along the annular flow path 18, heat is transferred from the gases to components in the turbine section. The arrays of rotor blades are bathed in the hot working medium gases and respond more quickly than does the outer case which is more remote from the working medium flow path. As a result, the radial gap G between the rotor blades and the outer air seal varies. An initial clearance is provided to accommodate this rapid expansion of the blades and disk. As time passes, the outer case receives heat from the gases and expands away from the rotor blades, increasing the gap G.
The gap G between the array of rotor blades 98 and the outer air seal is regulated by impinging cooling air on the coolable rail 22 to cause the coolable rail to contract and to move the outer air seal in closer to the array of rotor blades. Because the rail 22 moves both the upstream support and the downstream support, the supports move together and by the same radial amount to avoid tilting of the segments from front to rear. The tilting of the segments will cause an uneven variation in the gap between the axially extending tips of the rotor blade and the outer air seal and will either decrease or increase the clearance by an amount not anticipated. As a result of tilting, destructive contact between the rotor blade and the air seal may occur if an unexpected decrease in the gap occurs or if an increase occurs, a larger than normal amount of working medium gases may pass over the tips of the rotor blade decreasing the efficiency of the engine.
As a result of using only one coolable rail to position the upstream and downstream ends of the array of outer air seal segments, less cooling air is used as compared with constructions requiring two different coolable rails. Because energy is expended by the engine to compress the cooling air, a decrease in the use of cooling air improves the efficiency of the engine in comparison with those constructions which require more rails to position the array of outer air seals. Finally, by employing a single rail to position the outer air seal, a smaller amount of spray tubes and supporting hardware is required. With respect to the FIG. 3 embodiment, a further reduction in the number of parts results from combining the support for the array of outer air seals with the support for the array of stator vanes.
Although the invention has been shown and described with respect to detailed embodiments thereof, it should be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and the scope of the claimed invention.
|
A stator structure 34 for supporting an outer air seal 46 is disclosed. Various construction details which adapt the stator structure to evenly move inward and outward in response to the impingement of cooling air are developed. In one embodiment an upstream support ring and a downstream support ring for the outer air seal are attached together.
| 5
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention provides a means for alterting a user that a seismic sensor has reached or exceeded a safe design depth.
2. Discussion of the Prior Art
In the art of geophysical exploration at sea, a ship tows a seismic streamer cable along an assigned line of survey. The streamer cable may be one or two miles long and may contain many hundreds of hydrophones. A acoustic pulse is generated in the water at or near the surface. The pulse travels downwardly into the sub-ocean strata whence it is reflected back towards the water surface where the reflected signals are detected by the hydrophones. Ordinarily, the streamer cable and its hydrophones is towed at a depth of 25 to 50 meters.
Typically, a hydrophone consists of two piezoelectric ceramic wafers cemented to thin metal diaphragms which in turn are sealed to the opposite ends of a short cylindrical spacer. The opposite surfaces of the wafers are usually silvered and the wafers are polarized. Electrical signal leads are soldered to the silvered surfaces. Alternatively, one side or pole of each wafer may be cemented to the metal diaphragm with conductive epoxy. The diaphragm becomes one terminal. The other terminal is formed by a single lead soldered to the other face, that is, the free pole, of each wafer. Water pressure variations applied to the hydrophones cause the wafers to flex, giving rise to electrical output signals in response to the varying applied pressures.
Hydrophones, such as above described, have definite design operating-depth limits. If subjected to an excess hydrostatic pressure, the wafers bend too far inwardly, they crack and are destroyed. One such hydrophone is taught by U.S. Pat. No. 3,660,809 issued 05/02/72 to R. Pearson.
The cracking problem due to excess over-pressure can be solved to some extent by inserting a plastic stop inside the cylindrical spacer. In the presence of an excessive pressure, the diaphragm and wafer are deformed inwardly but bottom out against the stop. See for example, U.S. Pat. No. 3,970,878 issued 08/20/76 to C. Berglund, which is incorporated herein by reference. Although the piezoelectric wafer may not actually crack when subjected to an unsafe pressure, the electrical output signals are distorted and the hydrophone loses sensitivity. Furthermore, the case of a '878 type hydrophone tends to acquire a permanent set or crumpling when subjected to an excess pressure. That effect further distorts the output signal.
Streamer cables are provided with depth sensors to monitor the average cable depth. The depth sensors may be mounted on the streamer cable at intervals of perhaps 1000 feet or more. In between the depth sensors, the streamer cable may sink or sag to an unsafe depth, due for example to an abrupt local reduction in water density or to a change in towing speed, yet the operator would not necessarily know that fact. In the case of a '809-type sensor, destruction of the hydrophone would result in a dead signal channel but by the time the operator discovers that situation, it is too late; the hydrophone is ruined. In the case of a '878 hydrophone, the channel would still be alive but the signal distortion likely would remain unrecognized.
It is a purpose of this invention to provide a hydrophone having self-contained means for warning an operator that the hydrophone has reached or exceeded a safe design depth so that the operator can take remedial action before signal degradation occurs and/or the hydrophone is destroyed.
SUMMARY OF THE INVENTION
I provide a hydrophone for use in a body of water that consists of a sealed, conductive case that has parallel opposed end portions. The end portions are deformable in proportion to the applied hydrodynamic pressure. One pole of a polarized piezoelectric wafer is conductively cemented to the inner portion of one of the end portions. A conductor is soldered to the other or free pole of the wafer. When flexed due to deformation of the end portion by pressure variations, the wafer produces an electrical output signal. Means are mounted internally of the case for disabling the electrical output signals when the hydrophone is subjected to a pressure that exceeds a safe design pressure or depth limit.
In another aspect of this invention, the disabling means takes the form of a conductive stop. When the free pole of the wafer bottoms out and contacts the stop due to an overpressure, the conductive stop short circuits the electrical output signals to the case.
BRIEF DESCRIPTION OF THE FIGURES
These and other benefits of my invention will be better understood by reference to the detailed description and the drawings wherein:
FIG. 1 is a cross sectional view of the hydrophone of this invention;
FIG. 2 is an illustration of a polarized piezoelectric wafer;
FIG. 3 shows the configuration of the wafers when squeezed inwardly by an externally-applied pressure; and
FIG. 4 is an alternate embodiment of the hydrophone of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is shown a hydrophone generally shown as 8. The hydrophone 8 consists of a hollow conductive case that is preferably made in two halves 9 and 9' to provide parallel opposed deformable end portions 10 and 10'. Preferably the case is made of beryllium copper alloy, No. 25. The opposed end portions are deformable in proportion to variations in applied hydrostatic pressure. The details of construction of the case are described in the '878 patent mentioned supra.
With reference to FIG. 2, piezoelectric wafers such as 12 are provided. The wafer surfaces 11 and 11' are plated with a conductive silver overcoating and the wafer is polarized to form positive and negative poles as shown. The silver overcoating provides means for soldering electrical leads such as 13, 13' for conducting output voltages E- and E+ to the outside world when the wafer is flexed.
Returning to FIG. 1, piezoelectric wafers 12 and 12' are secured to the inner surfaces of deformable end portions 10 and 10' by conductive cement layers 14 and 14' such as epoxy with like poles facing each other. Preferably, the negative pole of the wafers is cemented to the deformable end portions so that the case itself serves as a common negative terminal. Electrical leads 16 and 16' are soldered to the inwardly-facing free or positive pole of each wafer and pass through the case via insulating grommets 18 and 18'. The structure of the insulating grommets is described in the '878 reference and need not be further described here.
A conductive disk 20, preferably of brass, having raised central portions or stops 22 and 22' is mounted internally between the two halves 9 and 9' of the case. The height of each case half is adjusted so that there is a small clearance such as 24 and 24' between the stops 22 and 22' and the free poles of wafers 12 and 12'. Thus, by dimensioning the case itself, I provide means for adjusting the clearance. The clearance is a function of the modulus of elasticity of the deformable end portions and the safe design pressure limit. For example, using the alloy mentioned supra, and for a design depth limit of 35 meters, the clearance is preferably 0.008 inch (in this disclosure, the terms depth and pressure are used interchangeably). The clearance is adjusted of course, when the pressures inside and outside the case are equalized. The clearance may be derived empirically from laboratory tests if desired. After the various components of the hydrophone 8 have been assembled, the two halves 9 and 9' of the case and the internally mounted conductive disk 20 are soldered together around the edges to seal the assembly against water invasion.
The stops 22 and 22' are designed limit the inward excursion of the deformable end portions and to electrically contact the free, inwardly-facing poles of the wafers 12 and 12' when they bottom out against the stops due to an overpressure that reaches or exceeds the safe design pressure P as shown in FIG. 3. When the deformable end portions 10 and 10' are squeezed inwardly by the external pressure, the electrical output E+ of the free inwardly-facing poles (which are of the like polarity) is short circuited to the case such that the hydrophone output signal is disabled; that is, E=0. Assuming that each hydrophone is coupled to its own signal display channel, the presence of one or more dead channels warns the operator that immediate remedial action is required to prevent harm to his instruments. In some streamer cables, a group of three or more hydrophones, spaced apart by a few feet, constitute a single channel. Because the hydrophones are so closely spaced, it is to be expected that not just one, but that the entire group will disable itself under adverse conditions. I have thus disclosed a self-contained depth warning system for a hydrophone.
In the previous discussion, it was assumed that the case of the hydrophone is metallic or at least conductive. If the case is made of some other material such as nonconductive plastic, the conductive disk 20 can serve as the common terminal for the negative, outwardly-facing poles of the wafers as shown by the wiring diagram of FIG. 4. Otherwise, the construction details remain substantially the same as for FIGS. 1-3.
In this disclosure, the term "hydrostatic pressure" refers to the static pressure due to a column of water at some particular depth. The term "hydrodynamic pressure" refers to the dynamic pressure differences that are created by acoustic wave fields propagating through the water at that particular depth. In effect, the hydrostatic pressure is an average pressure base line about which the hydrodynamic pressure variations fluctuate.
It is customary in the industry for the outwardly-facing pole of a wafer to have negative polarity and for an inwardly-facing pole to have positive polarity. Of course, that arrangement could be reversed, just so long as like poles face each other. Other design differences may be conceived by those skilled in the art but which will remain within the scope and spirit of this invention which is limited only by the appended claims.
|
A hydrophone having a self-contained means for warning an operator that the hydrophone has reached or exceeded a safe design depth limit. The active elements of the hydrophone are bender-type piezoelectric wafers. An internal stop is provided such that in the presence of a hydrostatic pressure that exceeds a safe design limit, the wafers bottom out against the stop. The stop short-circuits the electrical output signals of the wafers, warning the operator that the hydrophone is in danger of destruction.
| 6
|
This is a continuation-in-part of the U.S. application Ser. No. 08/081,856 filed on Jun. 23, 1993 now abandoned which is a continuation of U.S. application Ser. No. 07/806,823 filed on Dec. 6, 1991 now abandoned which is a continuation of U.S. application Ser. No. 07/485,252 filed on Feb. 26, 1990 now abandoned which takes priority from Japanese Application Serial Number 1-59075 filed on Mar. 10, 1989.
FIELD OF THE INVENTION
The present invention relates to a method of analyzing a solution, said solution being known beforehand to contain plural kinds of free acids and ions different from each other in temperature changes and conductivity changes which are to occur in response to a titrant, and more particularly to a method of analyzing a solution containing a strong acid, a weak acid, ferric ions (Fe 3+ ) and ferrous ions (Fe 2+ ) which are known beforehand to allow end points to appear in this order when the solution is subjected to a titration.
Japanese Laid Open Patent Application No. 62-2144 describes results of a thermometric titration for which the procedure had been known prior to the filing date of the afore-said Application No. 62-2144. In this thermometric titration, an aqueous solution of sodium hydroxide was used as a titrant, and an increasing amount of this titrant was added to a titrate in which nitric acid, hydrofluoric acid and ferric ions were known to coexist. Since nitric acid is a stronger acid and hydrofluoric acid is a weaker acid, a titration for determining the concentration of nitric acid naturally reaches an end point first, and a titration For determining the concentration of hydrofluoric acid reaches an end point next. On the other hand, hydrofluoric acid and nitric acid, both being relatively strong acids, do not vary from each other in reaching an end point so remarkably as a strong acid and a weak acid do from each other. Yet it is a known fact that respective end-point peaks of hydrofluoric acid and nitric acids vary from each other. Furthermore, as the titrant (sodium Hydroxide) is titrated, ferric ions (Fe 3+ ) and ferrous ions (Fe 3+ ) react with the titrant (sodium hydroxide) to form iron hydroxide which precipitates. However, solubility products by each of these ions in a same acid solution differ from each other, as a result, ferric ions (Fe 3+ ) precipitating earlier than ferrous ions (Fe 2+ ). This is depicted in FIGS. 10 and 11 (of the present specification) where the end points of respective ferric ions (Fe 3+ ) and ferrous ions (Fe 2+ ) vary from each other. In this way, the reaction on the titrant occurred in the order of nitric acid and hydrofluofic acid, and further in the order of ferric ions (Fe 3+ ) and ferrous ions (Fe 2+ ).
The prior art thermometric titration is such that, at the moment when a titration for determining the concentration of one kind of acid radicals or ions reaches an end point, a titration for determining the concentration of another kind of acid radicals or ions begins. There is little difference between the gradient of a line obtained from the preceding titration and the gradient of a line obtained from the succeeding titration. Consequently it is difficult to ascertain an end point of each titration which should appear as a point of intersection of the above-mentioned two lines.
The invention described in the Japanese Laid Open Patent Application No. 62-2144 was an attempt at overcoming the aforementioned difficulty of the prior art thermometric titration. A feature of this invention is the provision of a first temperature sensor capable of making a quick response to a temperature change and a second temperature sensor making a slow response to a temperature change. The difference between the output taken from the first temperature sensor and the output taken from the second temperature sensor was plotted on an ordinate against time on an abscissa. A differential temperature curve thus obtained has a clear point of inflection when an endothermic reaction is immediately followed by an exothermic reaction or vice versa in a series of chemical reactions which take place between the ingredients of the titrant and those of the titrate in the order named above.
However, when an endothermic reaction is immediately followed by another endothermic reaction or when an exothermic reaction is immediately followed by another exothermic reaction, it remains difficult to ascertain an end point which should exist between two reactions.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a method of analyzing a solution in which a thermometric titration and a conductometric titration are used complementarily so that an end point which is hardly ascertained by one method of titration may be ascertained by the other method.
In order that the above-mentioned object, together with others as will hereinafter appear, may be attainable, the present invention consists generally in the steps of: providing a solution containing at least two of plural kinds of known free acids and ions, said known free acids and ions being different from each other in temperature changes and conductivity changes which are to occur in response to a titrant; placing in said solution a differential temperature sensor and an electrical conductivity sensor; adding to said solution at a constant rate a titrant which chemically acts upon said known free acids and ions to cause a thermometric titration and a conductometric titration thereof; recording during said thermometric titration and said conductometric titration differential temperature values and electric conductivity values respectively obtained substantially simultaneously from said differential temperature sensor and said electrical conductivity sensor; generating from respective recorded values a differential temperature curve and an electric conductivity curve; finding peak values on said electric conductivity curve and peak values on said differential temperature curve; measuring a length of time required for adding an increasing amount of said titrant until an point is reached, as indicated by each of said peak values; and finding a quantity of said titrant added during said length of time so as so obtain the concentration of free acids in said solution.
In accordance with the present invention, each end point has substantially even degree of articulation because of a thermometric titration and a conductometric titration used complementarily so that an end point which is hardly ascertained by one method of titration may be ascertained by the other method.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a construction of a detecting portion for carrying out the thermometric titration and the measurement of electrical conductivity in an apparatus according to one preferred embodiment of the present invention;
FIG. 2 is an enlarged front view showing an electrical conductivity sensor shown in Fig. 1;
FIG. 3 is a bottom view showing the sensor shown in FIG. 2;
FIG. 4 is a diagram showing a sectional shape of an electrode in the sensor shown in FIGS. 2, 3;
FIG. 5 is a front view showing the sensor integrally comprising a temperature-sensitive resistance element and the electrical conductivity sensor shown in FIG. 1;
FIG. 6 is a bottom view showing the sensor shown in FIG. 5;
FIG. 7 is a rough block diagram showing a basic control device according to the present invention;
FIG. 8 shows a device for carrying out the temperature titration and the measurement of electrical conductivity.
FIG. 9 is a flow chart corresponding to the device shown in FIG. 8; and
FIGS. 10 and 11 illustrate two curves, respectively depicting the results of a thermometric titration and a conductometric titration.
ADDITIONAL DISCLOSURE OF THE INVENTION
The temperature-change and the electrical conductivity-change, which are basic ideas of the present invention, are described with reference to FIG. 1.
As to the temperature-change of the reaction solution, the titration time in a reaction tank (1) is short and said reaction tank (1) is held within an insulating system, so that it is hardly required to take the going in and out of heat other than the reaction heat into consideration. A pair of heat-sensitive resistance elements (2),(3) shown in FIG. 1 form an element for putting a first mode into practice, that is a differential temperature-detecting portion, adapted to have a difference in thermal response speed so as to detect the temperature-change due to the chemical reactions of dissolved ions with high sensitivity in the titration. In a temperature-detecting portion of said heat-sensitive resistance elements (2),(3), a difference in indicated temperature ΔT=T 1 -T 2 resulting from an endothermic phenomenon or an exothermic phenomenon generated by the chemical reaction within an appointed short time (about 10 to 30 msec) in the reaction tank (1) is detected (T 1-- an indicated temperature value of the heat-sensitive resistance element having a faster thermal response speed, T 2-- an indicated temperature value of the heat-sensitive resistance element having a slower thermal response speed). If such detecting method is used, a temperature-change curve is apparently a primary differential curve. Hereinafter the method of detecting this temperature difference is referred to as the indication difference method. The temperature-change curve obtained by this indication difference method responds sharply to the smallest temperature-change. Since a change of electric resistance caused by a temperature in this indication difference method is very small, a signal is converted into an electric current by the unbalance of a bridge circuit (7) including a direct current-stabilizing power source (6) and then converted into a signal of voltage gradient dE/dt (dE: voltage-change; dt: very small time) through an amplifier circuit (8) followed by being taken in a computer (14) through a detector-changing over circuit (11), a changing over signal-generating portion (12) and an A/D convertor circuit (13) to be an object of the operation and control.
On the other hand, the electrical conductivity-change curve is obtained from a change of electrical conductivity in the solution with the lapse of time and the electrical conductivity is detected by means of an electrical conductivity sensor (4) provided with a pair of electrodes.
Said electrical conductivity sensor (2) is detailedly shown in FIGS. 2 to 4. Reference numeral (21) designates a cylindrical supporting member formed of chemically stable resins. Reference numeral (22) designates a pair of electrodes passing through said supporting member (21) in the longitudinal direction and projecting outward from the supporting member (21) at a pointed end portion thereof. Said pair of electrodes (22) are formed of platinum electrodes disposed at an appointed interval therebetween and have an elliptical or non-circular section so that a ratio of the transversal diameter (a) to the conjugate axis (b) a:b may be 0.5:1.0 to 0.8:1.0. This sectional shape is uniform from the portion of the supporting member (21) to the pointed end of the electrodes (22).
A stirrer (23) is provided within the reaction tank (1) to stir a sample solution (24). If bubbles, which are generated in the stirring operation, and floating matters, which are produced in the titration reaction, are adhered to a surface of the electrodes (22), a surface area of the electrodes is changed, whereby the result of measurement is influenced in the form of the fluctuation of the indicated value of electrical conductivity and noises. In order to prevent foreign matters from adhering to the surface of the electrodes, it is sufficient to strongly stir but the strong stirring enhances the introduction of bubbles into the sample solution (24), whereby it is difficult to obtain stabilized data of measurement. On the contrary, if the elliptical section as shown in Figs.2 to 4 is used, the adherence of foreign matters to the surface of the electrodes (22) can be prevented even by weakly stirring.
A differential temperature sensor can be integrated with the electrical conductivity sensor (4), as shown in FIGS. 5, 6. Measured values under the same one condition in the reaction tank (1) can be obtained without being accompanied by a substantial time lag by housing the heat-sensitive resistance elements (2), (3) in the supporting member (21), as shown in FIGS. 5, 6. As a result, a time lag in the analysis of data can be reduced to improve the accuracy. Also the heat-sensitive resistance elements (2), (3) have an elliptical section in the same manner as the electrodes (22) to increase the stability of measured values.
With the electrodes having an elliptical section shown in FIGS. 2 to 6, in the general system, in which electrodes are disposed within a titration-reaction tank and an insoluble dispersoid is formed within the reaction tank according to a kind of titrating solution used in dependence upon substances contained in the sample solution, the adherence of the reaction products to a surface of the electrodes can be effectively prevented.
A signal obtained by the use of the electrodes (22) having such the special shape catches the electrical conductivity-change in the form of a voltage-change, so that it is converted into an electric current by the unbalance of the bridge circuit (9) including an alternating-current power source (6a) for use in the measurement of electrical conductivity therein and then converted into a signal of voltage gradient dE/dt (dE: voltage-change; dt: very small time) through the amplifier circuit (10) followed by being taken in the computer (14) through the detector-changing over circuit (11), the changing over signal-generating portion (12) and the A/D convertor circuit (13) to be operated and controlled. In the above described manner, the electrical conductivity change can be continuously detected by the second mode from the start of the titration until the completion of the chemical reaction in the reaction tank (1) to obtain the electrical conductivity curve for the whole chemical reaction. Hereinafter this mode is referred to as the electrical conductivity-change method.
The respective change curves obtained by the indication difference method and the electrical conductivity-change method are stocked in the computer (12) time-sequentially and operated to determine the end point of the reaction. Whereupon, both change curves are analyzed at once to determine various kinds of factor, such as concentration of every solute ionic ingredient and total quantity of acids, in the sample solution in which the chemical reaction has been brought about.
An apparatus, in which two detecting methods and detecting mechanisms--said indication difference method and said electrical conductivity-change method--are incorporated into the continuous elution line, and a method of operating said apparatus are below roughly described.
With this apparatus, a previously set appointed quantity of the solution eluted from the continuous elution line, in which known kinds of ion are contained, is automatically introduced into the reaction tank for every appointed quantity of elution or appointed time and the titrating solution is continuously poured into said reaction tank at a constant rate to automatically and continuously separate and quantitatively determine many kinds of ionic ingredient dissolved in the eluted solution within a short time. Its basic construction is described with reference to Fig. 7. As shown in FIG. 7, the appointed quantity of eluted solution is introduced into the reaction tank by opening any one of valves (a), (b), (c) by means of at least one series of "continuous elution line condition-setting means", a valve (d) of the titration tank being opened by "sampling-drainage change over valve-controlling means" and "quantity or time-setting means" to automatically and continuously add the previously prepared titrating solution to the eluted solution at the constant rate, thereby brining about the chemical reaction, with the very small temperature-change and electrical conductivity-change resulting from the chemical reaction being continuously detected by two characteristic signal values to analyze the reaction. In order to conduct this analysis and control operation of the present apparatus, "data-storing and analytical operation-controlling means" is provided. This analytical means is provided with means for determining the total quantity of acids and the like of the continuous elution line.
According to the present invention, the temperature-change and electrical conductivity-change of the reaction liquid can be continuously detected to separate and quantitatively determine the ionic ingredients dissolved. In case of need, a program for controlling the quantity of sample solution to be introduced into the reaction tank or a program of a large number of "continuous elution line condition-setting means", a program of "sampling-drainage change over valve-controlling means " opening a valve (f) of the reaction tank and a driving mechanism may be adopted. For example, in the case where it is not necessary to measure the temperature-change and the electrical conductivity-change within the reaction tank, it is sufficient to put "a previously appointed control prospect" in the computer and drain the solution from the reaction tank by controlling the valve (f). In addition, for example in the case where the concentration of the ingredients in the solution is extraordinarily high so as not to be able to sufficiently stir, "optimum reaction condition-establishing means" capable of adjusting the reaction conditions to the optimum values by opening a valve (e) of a diluent solution tank to add a diluent solution to the sample solution may be provided. Furthermore, a digital computer is suitably used for the operation and control in the present apparatus but also an analog operating controller may be used.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the apparatus according to the present invention are concretely described below with reference to FIG. 8.
In addition, FIG. 8 shows one preferred embodiment of the present invention merely for illustration and accordingly, the present invention is not limited by the preferred embodiments. The apparatus shown in the drawing according to the preferred embodiments is described with the case where it is used for the partition quantitative determination of many kinds of dissolved ionic ingredient as an example.
EXAMPLE 1
Referring to FIG. 8, a sample pickling solution comprising HNO 3 and HF is introduced into a sample tank (32) from a bath tank (31), in which wire materials made of stainless alloys have been subjected to the pickling, an appointed quantity of the sample pickling solution being automatically taken out from said sample tank (32) by means of a pump (33) to be transferred to a cooling tank (34), where very small floating matters are filtrated, and the resulting filtrate being put in a filtration tank (35). Then, the filtrated sample solution is introduced into a measuring tank (37) to send a sample of 0.5 cc together with 10 cc of a diluent water (38), whose temperature has been previously controlled in a thermostatic oven (45), to a reaction tank (36) having an internal capacity of 18 cc with a meter (37a) of said measuring tank (37) measuring said diluent water (38). Said reaction tank (36) is formed of corrosion resistant materials such as polytetrafluoroethylene. The reaction vessel (36) is provided with a stirrer (50) formed of polytetrafluoroethylene disposed therewithin and insulated so as to make the heat exchange with the outside minimum.
After the lapse of about 80 seconds since the introduction of the diluent solution into the reaction tank (36), a previously prepared 2 N-sodium hydroxide titrating solution is begun to be poured into the reaction tank (36) through a titrating solution-supply portion (46) from a tank (48) by means of a constant-quantity filling pump (47) to bring about a neutralization reaction within the reaction tank (36). A state of reaction solution changing with the lapse of time resulting from the neutralization reaction within the reaction tank (36) is continuously converted into signals in a temperature-detecting portion (39) and an electrical conductivity-detecting portion of the respective sensors in the indication difference method and the electrical conductivity-change method and the resulting signals are put in a computer (42) through a signal conversion circuit (41) to compile and analyze data.
Referring to FIG. 8 again, reference numeral (43) designates a temperature-controlling pipe of the titrating solution communicated with a thermostatic tank (45). Reference numeral (44) designates a temperature-regulating portion of said thermostatic tank (45). Reference numerals (51), (53) designate a driving motor for driving the titrating solution-supply portion (46) and the constant-quantity filling pump (47), respectively. Reference numerals (49), (52) designate a stirrer for the sample tank (32) and the thermostatic tank (45), respectively. Reference numeral (54) designates a drain-receiving tank for the solution stocked for measuring the sample.
If the constant-quantity feeding of the titrating 2 N-aqueous solution of sodium hydroxide is conducted at such a rate that the reaction may arrive at the end point within about 120 to 180 seconds, the thermometric-titration and the electrical conductivity-change can be easily analyzed. In addition, a quantity of the solution used for the titration about 1/10 to 1/20 times that of the diluent solution is optimum.
In order to still further detailedly describe the preferred embodiments of the present invention, a flow chart of programs shown in FIG. 9 relating to the apparatus and mechanism shown in FIG. 8 is described below.
In the process according to the present invention, the initial values of constants for the measurement and control as well as the measuring conditions, in particular their optimum conditions, are put in from outside, the sample eluted solution being introduced into the reaction tank from the previously appointed bath tank, the reaction reagent being added to the sample eluted solution to bring about the chemical reaction, and the temperature-change and ionic dissociation characteristics in the process of said chemical reaction being detected by two methods--the indication difference method and the electrical conductivity-change method.
The detection of these two signals is put into practice from the I/O program of the temperature-detection and electrical conductivity-detection through the control-starting program.
In the detection of these two signals, in order to improve the S/N ratio, the levelling treatment is carried out and when the S/N ratio reaches the appointed value, the respective signals and the respective times at that time being determined, and then they are memorized in the form of the respective signal values corresponding thereto.
In this flow, the positions of the equivalent points of the reactions brought about in the respective reaction steps are calculated by the supplementary program for looking for the point of inflection from the temperature-change curve obtained by the indication difference method.
These two signal-change curves are continuously watched on a CRT of a terminal of the computer until the measurement reaches the end point and the measured points are recorded. After the completion of the measurement, the signal values of the temperature-change and the electrical conductivity-change obtained by two methods are taken out from the memory to be automatically processed by an editing program, for example an operation of marking the point of inflection in the curve is automatically carried out. The results of the thermometric-titration and the measurement of electrical conductivity are shown in FIG. 10. It is judged that the largest point of inflection seen first from a titration-starting point of time (T 0 ) on the electrical conductivity-change curve is an equivalent point (T 1 ) of a nitrate group and the largest point of inflection (T 2 ) seen on the differential temperature-change curve is a synthetic equivalent point of free acids. Subsequently, a point of inflection (T 3 ) seen on the electrical conductivity-change curve is determined. This (T 3 ) is an equivalent point of metallic salts and (T 4 ) is determined additionally. As to the end point of the reaction, the largest and last point of inflection seen on the electrical conductivity-change curve after the point of time when no point of inflection can be seen on the differential temperature-change curve is regarded as the end point of the reaction. The end point (T 4 ) of the whole chemical reaction system is determined from the electrical conductivity-change curve in the above described manner to determine the total quantity of acids, and additionally the respective compositional ratios are determined from the respective pseudoequivalent points (or peak valves on the differential temperature curve), which have been previously determined by the indication difference method, and the points of inflection on the electrical conductivity-change curve are determined by the supplementary program.
On the basis of the analysis of the above described points of inflection, the compositions of the respective ingredients are determined as follows, that is a quantity of a free nitric acid group is calculated by (T 1 )-(T 0 ), a quantity of fluoric acid group being calculated by (T 2 )-(T 1 ), a quantity of 3-valence metallic ions being calculated by (T 3 )-(T 2 ), and a quantity of 2-valence metallic ions being calculated by (T 4 )-(T 3 ). Accordingly, the total quantity of free acid groups is determined by (T 2 )-(T 0 ) and the total quantity of metallic ingredients is determined by (T 4 )-(T 2 ).
After the completion of the analysis of the chemical reaction, the results are printed by means of a printer or put in a memory medium for filing. In addition, it is possible also to reproduce the control by looking up the past files in case of need. Besides, in order to cope with the changes of the measuring conditions, a squeezible supplementary program is provided.
According to the present preferred embodiment, the temperature-change and the electrical conductivity-change brought about in the reaction tank can be caught sharply and in high accuracy by obtaining two kinds of change curve by the use of the indication difference method together with the electrical conductivity-change method. That is to say, since the differential temperature curve and the electrical conductivity curve show sharp changes at the equivalent points in the respective steps of the reaction, the existence of the equivalent points can be surely shown and the quantity of the titrating solution consumed until the respective equivalent points can be shown in high accuracy.
The indication difference method can sharply detect the equivalences of the respective free acids. On the other hand, the electrical conductivity-change method shows HNO 3 , 2-valence metals and the change of the end point of the reaction more clearly than the indication difference method.
Even the sample solution, which is difficult to judge by merely the differential temperature curve, can be appropriately and surely detected and judged by synergistically using these two detecting methods to investigate also the electrical conductivity curve. In addition, the detecting method can be simplified. The influences by heat coming from the outside during the reaction and the change of the heat-sensitive resistance element in detection sensitivity by the floating matters formed by the reaction are compensated by measuring the electrical resistance curve.
The total quantity of free acids, the quantity of the free nitric acid ion and the quantity of the free fluorine ion were calculated from the points of inflection obtained by the indication difference method and the points of inflection obtained by the electrical conductivity-change method of the curves shown in FIG. 10 and the concentrations of ferrous ion and ferric ion were calculated from the points of inflection obtained by the electrical conductivity-change method by means of the computer.
The concentration of each kind of free acids or ions was determined by measuring a length of time required for adding at the constant rate an increasing amount of the titrant until an end point was reached, as indicated by each of the peak values, and by finding a quantity of the titrant added during the abovementioned length of time.
The reliability of the kinds and concentrations of the respective eluted ionic ingredients determined by the present method and apparatus was confirmed by putting the standard solutions of the respective ions in the same one apparatus, pouring the titrating solution into said respective standard solutions to make the chemical reactions progress, obtaining the differential temperature curve and the electrical conductivity curve, and analyzing said curves.
As a result, it was found that all kinds of ionic ingredient in the present preferred embodiment of the present invention were shown on the graphs and errors of measurement for the respective ion concentrations were held within ±2.5 %. Thus, it was confirmed that the respective ionic ingredients in the solution eluted from the metal pickled could be accurately identified and quantitatively determined by the method and apparatus according to the present invention. Table 1 shows the titrating conditions and the measured results according to the method disclosed in the above described Japanese Patent Application Laid-Open No. Sho 62-2144 and the method of the present invention.
TABLE 1__________________________________________________________________________ Tem- Free nitric acid Free HF Fe(3+) Fe(2+) Total acidTemperature perature (N) (N) (N) (N) (N)within the of alkali to Theore- Measur- Theore- Measur- Theore- Measur- Theore- Measur- Theore- Measur-reaction tank be poured tical ed tical ed tical ed tical ed tical ed__________________________________________________________________________Method according to Japanese Patent Application Laid-Open No. Sho62-214415° C. 14.5° C. 0.8 0.75 0.5 0.55 0.3 0.25 0.3 0.31 1.9 1.8620° C. 18° C. 0.8 0.65 0.5 0.65 0.3 0.4 0.3 0.2 1.9 1.920 20 0.8 0.87 0.5 0.43 0.3 0.35 0.3 0.3 1.9 1.9525 19 0.8 0.70 0.5 0.6 0.3 0.15 0.3 0.4 1.9 1.85Method according to the present invention15° C. 14.5° C. 0.8 0.78 0.5 0.51 0.3 0.28 0.3 0.29 1.9 1.8620° C. 18° C. 0.8 0.79 0.5 0.50 0.3 0.29 0.3 0.29 1.9 1.8720 20 0.8 0.79 0.5 0.49 0.3 0.30 0.3 0.31 1.9 1.8925 19 0.8 0.81 0.5 0.49 0.3 0.29 0.3 0.29 1.9 1.88__________________________________________________________________________
In addition, the present invention is superior also in the case where a mixture of compounds different in reaction heat and ionic dissociation characteristic is analyzed. Furthermore, even in the case where a mixture containing compounds, which are difficult to be dissociated, is analyzed, the partition is possible by making them coexist in the form of third substances, which easily form a complex, to generate a difference between the mixed substances if reaction speed.
EXAMPLE 2
A solution containing HNO 3 and HCl eluted from a metal when pickled was analyzed by the method used in EXAMPLE 1.
As shown in FIG. 11, the detections of free acids, such as HNO 3 (T 2 ) and HCl (T 5 ), and ferric ion (T 3 ) were possible.
|
A method of determining the concentrations of at least two of plural kinds of known free acids and ions contained in a solution, wherein these known free acids and ions are known beforehand to be different from each other in temperature changes and conductivity changes which are to occur in response to a titrant. The method includes a step of generating a differential temperature curve and an electric conductivity curve, which are obtained from a thermometric titration and a conductometric titration respectively and are used complementarily so that an end point which is hardly ascertained by one method of titration may be ascertained by the other method.
| 6
|
BACKGROUND OF THE INVENTION
This invention relates generally to crossbows, and more particularly, to an improved retention and release mechanism for a drawn bowstring.
With the present arrangement, a unique structure is provided to allow a crossbow user to quickly and positively secure a drawn bowstring in the ready or cocked position without any separate manipulation of levers or catches being required before drawing of the crossbow. Prior crossbows are known wherein the user must initially set or cock a bowstring retaining member prior to drawing a bowstring and then insuring that the drawn string engages behind or beneath a catch member. Most usually, a metal to metal sear mechanism has been used and which, during shooting, relies upon one metal surface sliding across another metal surface. In view of the substantial pressure exerted between these two surfaces, the mating parts need be made of hardened steel to prevent rapid wear and in some cases wear has remained a problem, causing inconsistent trigger pressures and possible misfires. Many earlier devices lacked sufficient structure to provide positive, reliable safety means when handling the loaded crossbow.
By the present invention, a trigger assembly is provided comprising a self-contained housing within which all of the components are located to enable the simple and positive insertion, locking and retention of a drawn bowstring, together with an automatically actuated safety element which is placed in the safe position by the very insertion of the drawn bowstring. In this manner, following any drawing and cocking of the bowstring, the user subsequently manipulates the safety element to place it in the armed or off position prior to depressing a trigger serving to release the mechanism.
Accordingly, one of the objects of the present invention is to provide an improved bow trigger mechanism including a bowstring catch member normally disposed within the path of a guide slot and wherein insertion of the bowstring therein deflects the catch member as the bowstring passes thereover with the catch member thereafter returning to a vertical position within the guide slot and retaining the bowstring until a sear is displaced to release the catch member from its vertical position and allow the drawn bowstring to forwardly exit the guide slot.
A further object of the present invention is to provide an improved crossbow trigger mechanism including a housing having a guide slot for receiving a drawn bowstring whereupon insertion of a bowstring therein initially rearwardly deflects a string catch member while simultaneously displacing a safety element into a position locking a sear against any pivotal movement which could thereby produce a release of the catch member and bowstring.
Still another object of the present invention is to provide an improved crossbow trigger mechanism including a trigger assembly housing removably insertable within a bowstock and containing therein a pivotal string catch and safety member automatically displaced into one of two alternate positions by the insertion of a drawn bowstring into a guide throat of the housing.
With these and other objects in view, which will more readily appear as the nature of the invention is better understood, the invention consists of the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed with reference being made to the attached drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side elevation of a crossbow employing the present invention;
FIG. 2 is an enlarged side elevation illustrating the interior of the trigger assembly housing;
FIG. 3 is a front elevation of the trigger assembly housing; and
FIG. 4 is a fragmentary view illustrating components of the trigger assembly housing as they appear with a bowstring in the loaded or cocked position and with the safety on.
Similar reference characters designate corresponding parts throughout the several figures of the drawing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, particularly FIG. 1, this invention will be seen to relate to a crossbow, generally designated 1 and which includes, adjacent its forward end, suitable structure adapted to provide tension upon a bowstring 2, when drawn toward the rear of the crossbow. As this invention is primarily directed to the structure of a trigger mechanism, it will be appreciated that any of the various well-known assemblies may be affixed to the forward end 3 of the bow 1 to provide a tensioned bow string 2, such as the illustrated flexible bow limbs 4--4 having appropriate cams or eccentric pulleys 5,6 pivotally mounted at their ends in a manner similar to the well-known compound bows. This forwardly disposed structure may also include an arrow rest or forward arrow guide 7 as well as any well-known bowsight 8, such as the illustrated vertical plate 9 having a plurality of inclined slots 10, each adapted to removably and adjustably receive one or more sight bars or posts 10-11. The crossbow is shown as including a frame, generally designated F, which may include any appropriate construction such as the illustrated lightweight metallic channel construction extending substantially the majority of the length of the crossbow. Suitably removably affixed to this frame is a fore-stock 12, handgrip 13 and rearmost shoulder stock 14.
In use, a trigger assembly, generally designated T, serves to receive, retain, and selectively release a bolt or arrow A extending from the forward arrow rest 7 rearwardly to the bowstring 2 when the latter is drawn and engaged by the trigger mechanism. The relative position of nock 15 of the arrow as well as the bowstring 2, with respect to the structure of the trigger mechanism, is shown most clearly in FIG. 4 of the drawing.
As will be seen most clearly in FIG. 2, the trigger assembly T includes a trigger mechanism M, comprising a housing H preferably formed with two laterally adjacent sections 16-17. In this manner the majority of moving components of the trigger assembly T are mounted within a single manipulatable housing H which may be handled as a separate unit selectively insertable in a cavity C formed in the crossbow frame. Any repair or replacement of the components of the trigger assembly housing H is readily accomplished simply by removing the housing from the crossbow frame and opening same by the subsequent removal of the housing section 17 from its cooperating section 16. This latter operation is accomplished by the removal of a plurality of screws 18, serving to join the two housing sections together through the juxtaposed bores 19.
As shown most clearly in FIG. 2 of the drawing, the housing H includes a lower body 25 having an upper arm 26 spaced thereabove to provide an arrow and bowstring guide throat or slot 27 extending rearwardly from the housing front wall 28 a substantial distance. This slot 27 fully extends horizontally through the housing and the forward portion of the upper arm 26 includes a tapered or inclined wall 29, serving to facilitate the insertion of the bowstring 2 into the slot. As a bowstring is drawn into the slot, either manually or by any of wellknown crossbow cocking devices, the nocking area of the bowstring strikes a shoulder 30 formed on a first end 31 of a bowstring nut or catch member 32. As will be seen most clearly in FIG. 3, this end of the catch member is bifurcated to provide a central slot 33 between two side portions 34-34 for reasons which will become obvious hereinafter. The catch member 32 is mounted for pivotal displacement about a medially disposed pivot pin 35 affixed to the housing section 16 while the second or lower end 36 of the catch member carries a pin 37 supporting one end of an extension spring 38. The opposite end of this spring is appropriately affixed to a pin 39 carried by the housing section 16 so that at all times the lower or second end 36 of the catch member is under the influence of this spring, and accordingly is constantly biased to a substantially vertical disposition urging the catch member shoulder 30 to the position as shown in FIG. 2 of the drawing.
Cooperating with the pivotally supported catch member 32, is a roller member or sear 40 comprising a plate element mounted for arcuate or pivotal displacement about a pivot pin 41 carried by the housing section 16. A portion 42 projects downwardly from the main body of the sear 40 to provide an actuating member arm, the operation of which will be described hereinafter. This arm 42 is constantly engaged by a sear compression spring 43 having one end stationary with respect to the housing section while its opposite end engages the sear arm 42, such that the sear 40 is continually urged in a clockwise direction about its pivot 41 with the limit of travel of the sear arm being defined by a stationary limit stop 44, offered by an appropriate abutment in the housing section 16.
The disposition of the various described elements as depicted in FIG. 2 of the drawing represents their relationship when the trigger assembly is either ready to receive the bowstring 2, or has just released the bowstring following actuation of an associated trigger. The trigger 45 as shown in FIG. 1 may be remotely located in the area of the handgrip 13 and includes an elongated element pivotally attached at its upper end to a stationary pivot 46 carried by the upper portion of the crossbow frame F. The medial portion of the trigger 45 passes through a horizontally extending bore or tunnel 47 extending along the lower portion of the corssbow frame and communicating with a recess 48 formed between the two lower portions of the housing sections 16-17. Disposed within this horizontal tunnel 47 is a trigger push rod or extension arm 49 loosely surrounding and engaging the trigger 45 intermediate its pivot 46 and lower finger portion 50 so that the rearmost portion 51 of the trigger extension arm 49 engages the trigger assembly sear actuating arm 42. In this manner, the force of the sear compression spring 43 not only normally urges the sear to the position of FIG. 2 but also normally maintains the trigger 45 urged to the position as shown in FIG. 1, which is the forwardmost limit of its movement. In this readied position, a forward curved surface on the sear 40 will be seen to engage and maintain the string catch member 32 in the illustrated vertical position. This referenced surface of the sear may be considered a sear nose 52, and is located immediately adjacent a cut-out or recessed portion 53 of the sear periphery. The contact between the sear nose 52 and string catch member 32 is preferably provided by a roller 54 pivotally carried by the second or lower end 36 of the catch member, so that a more friction-free engagement between the sear and catch member is provided. Re an alternative, the sear nose itself may comprise another roller (not shown) pivotally supported on the sear 40 and adapted normally to engage the catch member roller 54 in an off-center manner, above a line passing between the pins 37 and 41.
Before describing the sequence of operation of the various trigger mechanism components, one other important feature should be understood. This comprises safety means carried by the housing H and which is automatically actuated or placed in the safe or on position during the loading or attachment of the bowstring within the trigger assembly M. This safety means comprises a safety element, generally designated 60, which will be seen to include a generally horizontally disposed elongated member having a front section 61 and rear section 62 and which is mounted for pivotal displacement by means of a pivot pin 76 projecting inwardly from the housing section 16 to engage the medial portion of the safety element 60.
The safety element includes an inclined surface 64 extending downwardly and rearwardly from the forewardmost portion thereof to provide a cam surface normally within the path of the guide slot 27. It is important to note that the vertical extent of at least the front section 61 of the safety element is offset to one side of the center longitudinal axis as defined by a line passing between the side portions 34 of the string catch member 32. In other words, the safety element from section 61 is not within the path of an arrow nocking point as subsequently introduced through the string catch member slot 33, for reasons which will become obvious hereinafter. Safety element 60 is normally urged to one of two positions such as shown in FIGS. 2 and 4 by means of a double-acting torsion spring 65 which is anchored at a housing point or pin 65' and includes a relatively fixed end 66 and an opposite actuating end 67. The latter end constantly biases against the rear wall 68 of the safety element in an over center manner to retain the safety element in either of its alternate positions. This action is insured in view of the relative disposition of the spring anchor point 65' with respect to both the safety pivot 60 and the mass of the safety rear section 62. During stringing of the crossbow, the spring enforces a positive snapping of the safety member to the position of FIG. 4 whereupon a safety nose 69 thereon is urged downwardly into engagement within a recessed detent 70 formed in the periphery of the pivotal sear 40 thereby immobilizing the sear. The safety is considered to be on with this arrangement, and any attempt to depress the finger portion 50 of the trigger 45 is resisted since the sear and its actuating arm 42 are locked in a stationary position, thereby similarly immobilizing the trigger extension arm 49 and trigger 45.
Additional means may be included to indicate disposition of the safety element in the horizontal or off position as in FIG. 2 until such time as the safety is automatically or manually moved to the arcuately displaced, on position. This means comprises a fixed projection in the form of a ball bearing 71 having a portion of its surface projecting outwardly from the surrounding surface of the housing section 16. A mating detent or dimple 72, provided on the juxtaposed sidewall of the safety element receives the projection of the ball bearing 71 to additionally, temporarily retain the safety in the off position. To insure the foregoing biasing action, a compression spring 73 coiled about the safety element pivot pin 63 provides a constant urging apart between the housing section 17 and the left or first sidewall 74 of the safety element. In this matter it will be appreciated that the safety element will at all times be urged toward the housing section 16 and by selecting the strength of this compression spring 73 it is possible to determine the amount of force necessary to pivotally displace the safety element 60 from its off position to that of the on position. Although the ball bearing 71 is entirely optional, in view of the double-acting torsion spring 65, the compression spring 73 is utilized at all times since it maintains the sear element front section 61 to one side of the catch member central slot 33.
As shown in FIG. 3 of the drawings, the thickness or lateral extent of the safety element front section 61 is substantially equal to that of one of the catch member side portions 34 located adjacent to housing section 16 and this side portion and safety element will be understood to be disposed in a substantially common vertical plane. This construction not only allows for the insertion of the nock 15 of an arrow A through the catch member slot 33 without interference from the safety element 60 but also provides for the automatic operation of the safety element 60 during cocking of the bow.
The operation of the trigger mechanism will now be related. Prior to drawing and cocking the bowstring 2, the apparatus will appear as in FIG. 2, wherein the sear nose 52 abuts the string catch member 32 and the sear actuating arm 42 is spring-urged to its forwardmost position along with the trigger finger portion 50. As the bowstring 2 is drawn rearwardly it is introduced into the guide throat 27 of the trigger assembly housing H, being guided thereinto with the assistance of the inclined wall 29 of the housing upper arm 26. Upon striking the catch member shoulder 30, continued rearward movement of the bowstring urges the catch member to be displaced in a clockwise manner until both side portions 34-34 are moved rearwardly and downwardly to a point adjacent the lower surface of the housing guide slot 27. At this point continued rearward movement causes the string to completely pass or ride over the catch member shoulder 30 and in view of the constant downward force being applied by the spring 38, the catch member will then be returned to a substantially vertical position. Concurrently with the rearward or clockwise displacement of the catch member 32, the safety element 60 will be understood to be likewise arcuately displaced about its pivot 33 in a clockwise manner as one of the catch member side portions 34 engages and cams the safety element surface 64 until it is fully within the confines of the housing upper arm 26. In this position the safety member nose 69 is seated within the sear safety detent 70 as shown in FIG. 4. Following the above clockwise displacement of the safety member, the over center spring 65 exerts force upon the safety to assist in retaining it in the safe position of FIG. 4. At this point, any continued rearward movement of the drawn bowstring 2 will be halted as the bowstring reaches the rearmost limit of the guide slot 27 and the rearward force being applied to the bowstring is then terminated. Quite obviously, the force developed by the crossbow limbs 4-4 is quite sufficient at this point since the crossbow may be considered to be at full draw and accordingly, the bowstring nocking area comes to rest as it strikes the rear of the catch member shoulder 30 since the opposite or lower end 36 of the catch member is held stationary in view of the engagement of its roller 54 against the sear nose 52. Accidental displacement of the safety from its on position of FIG. 4 is precluded in view of the downward force exerted by the arm 67 of the torsion spring 65.
The arrow A at this point can be placed into position on the crossbow by appropriately positioning its forward portion with respect to the arrow rest 7, and rearwardly inserting the arrow nock 15 within the catch member slot 33 until the nock envelops the nocking area of the bowstring 2 behind the catch member.
The crossbow 1 is now cocked and ready to be used. No release of the arrow is possible as long as the safety remains on as shown in FIG. 4 but when the user is ready to release the arrow, the safety is manually moved to the off position of FIG. 2 by actuating a knob 76 projecting outwardly from its second sidewall 75 and through a slot 77 in the adjacent housing section 16. When thusly actuated, rearward pressure upon the trigger finger portion 50 produces a counter-clockwise rotation of the sear 40 to clear its nose 52 from engagement with the catch member to roller 54 whereupon the force being applied to the bowstring by the limbs 4--4 drives the nocking area of the bowstring in a forward direction along with its attached arrow. During this latter action, the bowstring has displaced the catch member 32 shoulder 30 in a counter-clockwise direction until the bowstring passes over the top thereof after which the bowstring exits the housing guide throat 27. During the movement of the catch member shoulder 30 to a point adjacent the lower area of the guide throat 27, it will be understood that the lower portion 36 is unobstructed during its movement to the right, in view of the sear cut-out portion 53.
The trigger assembly housing H may also serve to support a rear sight 79. The depicted sight comprises a vertical apertured plate having a base 80 suitably pivotally attached to the housing upper arm 26 to allow for displacement between alternate use and non-use positions. In the illustration of FIG. 1, this sight 79 is shown in its elevated, use position and when not being used, the sight is merely displaced clockwise 90 degrees about pivot 81 until the body of the sight is flush with the top of the trigger assembly housing H.
Although the trigger mechanism is shown with a trigger 45 remotely located in the area of the forward handgrip 13, it will be appreciated that the sear 40 may be controlled directly from the area of the housing. This is readily accomplished by providing an extension on the actuating arm 42 such that this extension would, in effect, become the trigger.
|
A crossbow includes a trigger mechanism providing positive setting or cocking and release of a drawn bowstring. As the bowstring is drawn, it is pulled rearwardly into a trigger assembly slot to momentarily rearwardly deflect and ride over a spring-urged string catch member. Deflection of the catch member in turn urges displacement of a safety element into locking engagement with a pivotal sear. A nose on the locked sear normally abuts the catch member to preclude its release of a bowstring cocked therebehind. Following manual displacement of the safety to an off position, squeezing of a trigger pivotally moves the sear nose clear of the catch member to permit the cocked bowstring to forwardly deflect and pass over the catch member as the bowstring leaves the trigger assembly and propels an arrow engaged thereby.
| 5
|
FIELD OF THE INVENTION
The present invention relates to methods for producing formulated products with reduced environmental impact and is particularly useful in formulating consumer products such as health and beauty products such as shampoos, conditioners, skin care compositions and the like by providing a new process to guide product developers in the selection of environmentally preferred ingredients.
BACKGROUND OF THE INVENTION
There has been increasing desire for products that are environmentally friendly. To insure that products can be sold and distributed on a global basis, manufacturers must take into account a wide variety of environmental legal requirements. Several different techniques have been developed for evaluating environmental issues that may arise when formulating products. In one approach there has been developed a “grading system” of suppliers as it relates to their environmental practices. The environmental history of raw material suppliers and their current environmental procedures are taken into account by various agencies that assign suppliers environmental grades. These grades are made available to purchasing managers, who may base their purchasing decisions on such history.
There are also environmental labeling systems which consider possible adverse environmental effects of products when determining if the product qualifies to bear the label. Such systems have been used by governments and non-governmental organizations having a reputation regarding environmental matters and will be used in their assessment when providing their seal of approval or equivalent.
U.S. Pat. No. 7,096,084 describes a method for categorizing ingredients with the goal of formulating products having a reduced environmental “footprint.” In accordance with the method in this patent, an ingredient can be assigned to an environmental class by choosing two categories of environmental concern from among many optional environmental categories. For example, aquatic toxicology, ultimate biodegradability, acute human toxicity lethal dose, European Union environmental classification, supplier source, and other significant concerns are disclosed as categories that can be considered for classifying a surfactant. In this method, the categories that can be considered for classifying an ingredient differ depending on the purpose of the ingredient; hence a single chemical could be assigned to two or more different environmental classes if it were added to a product for two or more different purposes, or if it were added to two or more similar products for two or more different purposes.
Also known are systems which adjust the grades of components used in a product by their relative weight in that product. For example, U.S. Pat. No. 5,933,765 discloses an environmental grading system in which a product containing multiple components has each of its input components provided with a numerical score based on toxicity. Each component is compared to a single published limit (such as a Dutch PPT Telecom standard) and a numerical value for that component is assigned. The scores are then weighted based on the relative percentage, by weight, of the raw material in the final product to provide an overall score for the resulting product. Regardless of the application of the raw material, only one possible score is provided for a given raw material chemical which is weighted by its prominence in the final product.
These environmental grading or rating systems do not provide an optimal system for formulating products where the use and potential environmental exposure patterns of all the products considered are similar. Methods that rely on the environmental performance of suppliers are not optimal for companies that use multiple sources for a single chemical component used in different regions or at different times. Methods that require each chemical component of a formulated product to be categorized depending on the component's function, which allows one chemical to achieve different environmental classifications as a result of the categorization, fail to recognize that the potential environmental effects of the component are not dependent on its function in a product, but rather, on its intrinsic environmental fate and effects characteristics and its exposure concentration in the environment, which are independent of its function in a product. Methods that consider only one aspect of environmental performance, such as toxicity, ignore environmentally relevant data that are readily available for many chemical components used n formulated products.
There exists a need for methods that evaluate the environmental impact of ingredients used in personal care products and methods for developing personal care products having a relatively safer environmental impact. These methods would evaluate the potential environmental impact of various chemical components in formulated personal care products and provide a decision support framework to reduce the potential environmental impact of these products based on those evaluations. It is desired that a system be developed for evaluating the environmental impact of chemical components and for formulating products having improved environmental characteristics. If a component in a product is known to have negative environmental attributes, environmental grading may be a deciding factor in determining whether that component is incorporated into the final product. In addition, there exists a need for a method that would allow a company to track its performance in reducing the environmental impact of the products that it produces.
SUMMARY OF THE INVENTION
In accordance with the present invention there has been provided a method for providing an environmental score to ingredients that may be used in a personal care product comprising;
selecting at least one ingredient that may be utilized in the personal care product, determining at least one alternative ingredient that is suitable for use in the personal care product,
determining an environmental score for the ingredient and the at least one alternative ingredient; wherein the environmental score for the ingredient and the alternative ingredient is independent of the functional use of the ingredient and is based on environmental persistence, bioaccumulation through the food chain, direct toxicity to aquatic organisms, wherein a low environmental score indicated that the ingredient has a potentially negative impact on the environment and a high environmental score indicates that the ingredient does not have a potentially negative impact on the environment, and choosing the ingredient having the highest environmental score.
Also provided in accordance with the present invention is a method for developing a personal care product having a safer environmental impact comprising;
obtaining a preliminary formula for the product having a plurality of ingredients, selecting at least one ingredient that is utilized in the product, determining at least one alternative ingredient that is suitable for use in the product,
determining an environmental score for the ingredient and the at least one alternative ingredient, wherein the environmental score for the ingredient and the alternative ingredient is independent of the functional use of the ingredient and is based environmental persistence, bioaccumulation through the food chain, direct toxicity to aquatic organisms, wherein a lower environmental score has a potentially negative impact on the environment and a higher environmental score has a potentially lower impact on the environment, and
choosing the ingredient having the highest environmental score and incorporating that ingredient into the product.
In accordance with another embodiment of the invention, there has been provided a method of tracking a company's performance in providing products having a potential impact on the environment, comprising;
obtaining an existing formula for a commercial product having a plurality of ingredients, determining an environmental score for at least a portion of the plurality of ingredients, wherein the environmental score for the ingredients is based on environmental persistence, bioaccumulation through the food chain, direct toxicity to aquatic organisms, wherein a lower environmental score has a potentially negative impact on the environment and a higher environmental score has a potentially lower impact on the environment, determining a product score as a weighted average score, considering only the ingredients in the formula for which a score has been determined determining an uncertainty interval around the product score when one or more of the ingredients in the formula have not been assigned an environmental score, wherein the upper confidence limit is determined by recalculating the weighted average product score assuming the highest possible environmental score applies for all unscored ingredients in the formula, and the lower confidence limit is determined by recalculating the weighted average product score assuming the lowest possible environmental score apples for all unscored ingredients in the formula. storing the environmental score and uncertainty interval for the commercial product.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowchart illustrating a Persistence Scoring Process
FIG. 2 is a flowchart illustrating a Bioaccumulation Scoring Process
FIG. 3 is a flowchart illustrating a Toxicity Scoring Process
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to methods for producing formulated products with reduced environmental impact and is particularly useful in formulating consumer products such as health and beauty products such as shampoos, conditioners, skin care compositions and the like. The present invention provides a new process to guide product developers in the selection of environmentally preferred ingredients by assigning a score that measures the intrinsic environmental hazard of an ingredient. The process provides an environmental performance score for ingredients that may be used in personal care products. The process may be further used to guide product developers in the selection of environmentally preferred ingredients and/or to permit a company to track their progress in reducing the environmental impact of their products. It is considered an important aspect of the present invention that the process assigns a score that measures the intrinsic environmental hazard of an ingredient without regard to the functional use of the ingredient in a product. As used herein, the terminology “function” or “functional use” refers to the general classification of an ingredient that is intended to be used in a formulated product, such classifications include, for example, solvent, emulsifier, pH control agent, thickening agent, etc. Thus, the potential environmental impact of an ingredient is determined by its environmental fate, its effects characteristics and its mode of entry into the environment, but not its value or function within a product.
The process of the present invention encourages the use of ingredients that are readily biodegradable and have minimal impact to the ecosystem and optionally allows product formulators to include environmental performance as an additional criterion when selecting ingredients in new product development, and further may optionally provide a process to measure and track overall progress in environmental performance, not only by a product formulation but also by a business unit. Once a formula is created, a formula environmental score may be calculated based on the individual environmental scores of the ingredients contained in the formula. While there are numerous ways to measure environmental performance, environmental scores in accordance with the present invention mainly reflect three key properties of an ingredient, environmental Persistence, Bioaccumulation and direct Toxicity (the PBT properties), which predict an ingredient's environmental hazard. Environmental Persistence has been shown to lead to widespread environmental exposure and unanticipated effects that are difficult to reverse. Bioaccumulation through the food chain has been shown to lead to high exposure levels to humans and important predators. Direct Toxicity to aquatic organisms has been shown to cause ecosystem damage by reducing populations of important animals and plants.
The environmental score reflects the synthesis of information from a wide range of sources addressing the expected environmental fate and effects of each ingredient. These include the following:
a) biodegradability in rigorous laboratory tests, b) degradation half-life in the environment, c) buildup of the ingredient in fish tissue, measured in the laboratory as the “bioconcentration factor,” and d) toxicity to a standard battery of aquatic test organisms, including invertebrates, algae, and fish, as measured in one- to four-day laboratory tests.
In accordance with the present invention, individual ingredients that are intended to be used in a formulated product are assigned an environmental score ranging from zero to 100. An environmental score of zero signifies that the ingredient has characteristics that could cause several different types of adverse environmental effects, under certain circumstances. An environmental score of 100 signifies that none of the characteristics evaluated suggests that the ingredient would pose an environmental concern when used in the final product. An environmental score that falls between these two extremes signifies an intermediate potential to cause adverse environmental effects. The use of a numeric score to measure the potential environmental hazard of an ingredient in a product will allow: shifting toward the use of more environmentally benign ingredients in new formulations, minimizing the use of ingredients that pose a potential environmental concern, tracking the use of scored ingredients, to provide the user with the ability to set goals for better scores and to measure progress in achieving these goals.
Thus each of the measures listed above for describing an ingredient's PBT properties are scaled between zero and 100. The scale for each PBT property is determined by assigning a score of 100 points to a consensus-based benchmark of no concern and assigning a score of zero points to a consensus-based benchmark of high concern. The scales for transforming the measures listed above to scores between zero and 100, and the benchmarks considered in deriving the scales, are shown in Table 1 through Table 5. The PBT (persistence, bioaccumulation, toxicity) score forms the basis of the present environmental scoring system and provides a measure of the intrinsic environmental hazard characteristics associated with an ingredient. The process for assigning a PBT score for an ingredient that is a distinct organic compound is described in the following sections.
An ingredient can be assigned an environmental performance score only when adequate data are available to completely characterize the PBT properties of the ingredient as listed above. Scores cannot be assigned if no reliable information is available to characterize persistence or bioaccumulation (with one exception—see Bioaccumulation Considerations for Readily Biodegradable Ingredients Section, below) or toxicity. Comparing ingredients head-to-head for the purpose of selecting an environmentally preferable alternative is ambiguous if each score is based on different characteristics. For example, if the environmental performance score could be assigned based on only one or two of the PBT characteristics, product formulators might select a non-bioaccumulative, low toxicity ingredient (with no information on persistence included in the score) over an ingredient of moderate persistence and low bioaccumulation potential and toxicity. However, the selected ingredient could be highly persistent, resulting in the process directing its user to select poorly.
The scores are based on empirical data whenever results from quality studies are available. When empirical data are lacking, predictive models may be used to fill data gaps by reviewing the content of numerous databases and environmental models, and the selection of a core set of comprehensive and reliable databases and models may be consulted for determining a score. The physical and chemical characteristics of each ingredient are compiled and evaluated to understand how the ingredient moves between water, sediment, soil, and air. The degradation rates for each ingredient when exposed to sunlight, water, and biodegrading microorganisms are compiled and evaluated to estimate the ingredient's persistence in the environment. The propensity of the ingredient to accumulate in the fat and tissues of fish are evaluated to understand the potential for the ingredient to bioaccumulate in the food chain. The concentrations of the ingredient that cause toxic effects to aquatic plants and animals from different levels of the food chain are evaluated to determine the potential toxicity of the ingredient in aquatic ecosystems. These evaluations of PBT properties form the basis of the ingredient's score.
The sub-scores for the P, B, and T characteristics are combined into a single numeric score by applying a weighting factor to each sub-score and summing them. The weighting factors account for the relative importance of P, B, and T characteristics, given the manner in which the ingredient is likely to enter the environment after its use in personal care products. Weighting factors differ for organic or inorganic ingredients, because the concepts of environmental persistence and bioaccumulation are defined differently for organic and inorganic compounds.
Final environmental performance scores are based on Persistence, Bioaccumulation and Toxicity with deductions for additional criteria (penalties). In the final score, a point reduction from an ingredient's PBT score is assessed if other pertinent environmental concerns have been raised by a government agency or in the peer-reviewed scientific literature. Four categories of these “other pertinent environmental concerns” are considered and any applicable point reductions are then applied to the PBT score, including photochemical smog-forming voc, potent chronic toxicity, formation of toxic metabolites and presence on a regulatory list.
Environmental Scoring for Ingredients that are Organic Compounds
Assigning a Persistence Score
Referring to FIG. 1 , one must obtain the results of a ready biodegradability test. The ready biodegradability test is a stringent laboratory screening test which is conducted under aerobic conditions in which a relatively high concentration of test substance (2 to 100 mg/L) is exposed to microorganisms. Biodegradation is measured using a non-specific parameter such as carbon dioxide production. As stated in Organization for Economic Co-operation and Development (OECD), 2006, “OECD Guidelines for the Testing of Chemicals, Revised Introduction to the OECD Guidelines for Testing of Chemicals, Section 3”, “given a positive result in a test of ready biodegradability, it may be assumed that the chemical will undergo rapid and ultimate biodegradation in the environment. In such cases, no further investigation of the biodegradability of the chemical, or of the possible environmental effects of transformation products, is normally required.” Hence, if reliable empirical data indicate the ingredient is readily biodegradable, assign a persistence score of 100. In the absence of reliable empirical ready biodegradability data, it is acceptable to use a widely accepted predictive model (e.g., the computer model BIOWIN™ which is a widely recognized wastewater treatment process modeling and simulation package which predicts the result of a ready biodegradability test, and is included in US EPA, 2009) to determine ready biodegradability. If the model indicates the ingredient is readily biodegradable, persistence score is 100 minus a modeling uncertainty penalty (e.g., 5 points). If reliable empirical data indicate the ingredient is not readily biodegradable, or in the absence of reliable empirical data, if a widely accepted predictive model indicates the ingredient is not readily biodegradable; then the environmental media of concern will need to be determined.
Determining the Environmental Media of Concern.
The first step is to use a level III fugacity model to determine the environmental partitioning of the ingredient, accounting for its dominant emission pattern (e.g., emission to municipal wastewater). A level III fugacity model assumes a simple, evaluative environment with user-defined volumes and densities and can include the following homogeneous environmental media (or compartments): air, water, soil, sediment, suspended sediment, fish and aerosols. The media of concern are those predicted to contain more than a threshold proportion of the emitted ingredient (e.g., 5%).
The next step is to obtain data for the ingredient's half-life(s) in all media of concern. If reliable empirical data for half-life(s) are absent, estimate the half-life(s) on the basis of all relevant empirical data augmented by the results of widely accepted predictive models (e.g., the computer models, BIOWIN™, HYDROWIN™, and AOPWIN™ which predict the degradation rate of a chemical undergoing biodegradation, chemical degradation in water, or atmospheric chemical degradation, respectively and are included in United States Environmental Protection Agency (US EPA). 2009 Estimation Programs Interface Suite™ for Microsoft® Windows, v 4.00, United States Environmental Protection Agency, Washington, D.C., USA., if data gaps exist. BIOWIN™ estimates aerobic and anaerobic biodegradability of organic chemicals using seven different models. Two of these are the original Biodegradation Probability Program (BPP™). The seventh model estimates anaerobic biodegradation potential. HYDROWIN™ estimates aqueous hydrolysis rate constants and half-lives for the following chemical classes; esters, carbamates, epoxides, halomethanes, selected alkyl halides, and phosphorus esters, estimates rate constants for acid- and base-catalyzed hydrolysis, but with the exception of phosphorus esters, not neutral hydrolysis. In addition, HYDROWIN™ identifies a variety of chemical structure classes for which hydrolysis may be significant (e.g. carbamates) and gives relevant experimental data. AOPWIN™ estimates the gas-phase reaction rate for the reaction between the most prevalent atmospheric oxidant, hydroxyl radicals, and a chemical. Gas-phase ozone radical reaction rates are also estimated for olefins and acetylenes. In addition, AOPWIN™ informs the user if nitrate radical reaction will be important. Atmospheric half-lives for each chemical are automatically calculated using assumed average hydroxyl radical and ozone concentrations). The estimation can be done using a widely accepted predictive model (e.g., Estimation Program Interface (EPI) Suite. The EPI (Estimation Programs Interface) Suite™ is a Windows®-based suite of physical/chemical property and environmental fate estimation programs developed by the EPA's Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC). EPI Suite™ uses a single input to run the following estimation programs: KOWWIN™, AOPWIN™, HENRYWIN™, MPBPWIN™, BIOWIN™, BioHCwin™, KOCWIN™, WSKOWWIN™, WATERNT™, BCFBAF™, HYDROWIN™, KOAWIN™ and AEROWIN™, and the fate models WVOLWIN™, STPWIN™ and LEV3EPI™ as well as ECOSAR™, which estimates ecotoxicity. EPI Suite™ is a screening-level tool and should not be used if acceptable measured values are available. A clear understanding of the estimation methods and their appropriate application is very important.
Using the linear scoring scales in Table 1 (water), Table 2 (air), and/or Table 3 (soil/sediment) the half-life(s) are transformed to Persistence score(s) for the media of concern. If a score is based on an estimated half-life rather than an empirical half-life, that score should be reduced by an uncertainty penalty (e.g., 5 points). The overall ingredient persistence score is assigned as the minimum persistence score among the individual scores for the media of concern.
TABLE 1
Persistence Scoring Scale for Ingredients in Water
Persistence
Fresh Water
Score
Half-life (days)
Regulatory Benchmarks Considered
100
<30
40 days - “Persistent” (2)
75
66
60 days - threshold for testing, exposure
50
105
control requirements (1), “Very
25
142
Persistent” (2); “Persistent” (3)
0
≧180
180 days - threshold for potential ban (1);
“Very Persistent” (3)
182 days - “Persistent” (4)
(1) (United States Environmental Protection Agency (US EPA). 1999a. “Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances.” Federal Register. 64(213): 60194-60204.)
(2) (European Chemicals Bureau (ECB). 2003. “Technical Guidance Document in support of Commission Directive 93/67/EEC on Risk Assessment for new notified substances, Commission Regulation (EC) No 1488/94 on Risk Assessment for existing substances. Direction 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal products on the market. Part II.”
(3) (United States Environmental Protection Agency (US EPA). 1999b. “Persistent Bioaccumulative Toxic (PBT) Chemicals; Lowering of Reporting Thresholds for Certain PBT Chemicals; Addition of Certain PBT Chemicals; Community Right-to-Know Toxic Chemical Reporting.” Federal Register. 64(209): 58665-58753.)
(4) (Environment Canada (EC). 2006. “Exiting Substances Evaluation: Categorization of the Domestic Substances List (DSL).” Internet content available (Oct. 11, 2009) at: http://www.ec.gc.ca/substances/ese/eng/dsl/cat_criteria_process.cfm)
TABLE 2
Persistence Scoring Scale for Ingredients in Air
Persistence
Score
Air Half-life (hours)
Regulatory Benchmarks Considered
100
<24
48 hours - “Persistent” (1), (2), (3)
75
47
120 hours - described as used by
50
72
regulatory bodies to determine if “a
25
96
chemical should have restrictions
0
≧120
on its uses.” (1)
(1) (United States Environmental Protection Agency (US EPA). 1999b. “Persistent Bioaccumulative Toxic (PBT) Chemicals; Lowering of Reporting Thresholds for Certain PBT Chemicals; Addition of Certain PBT Chemicals; Community Right-to-Know Toxic Chemical Reporting.” Federal Register. 64(209): 58665-58753.
(2) Gouin, T; Bocking, S; Mackay, D. 2005. “Policy by analogy: precautionary principle, science and polybrominated diphenyl ethers” Int. J. Global Environmental Issues. 5(1/2): 54-67.
(3) Environment Canada (EC). 2006. “Exiting Substances Evaluation: Categorization of the Domestic Substances List (DSL).” Internet content available (Oct. 11, 2009) at: http://www.ec.gc.ca/substances/ese/eng/dsl/cat_criteria_process.cfm
TABLE 3 Persistence Scoring Scale for Ingredients in Soil or Sediment Sediment or Persistence Soil Half-Life Score (days) Regulatory Benchmarks Considered 100 <50 60 days - threshold for testing, exposure 75 81 control requirements (1); “Persistent” (2) 50 115 120 days - “Persistent” (3) 25 147 180 days - threshold for potential ban (1); 0 ≧180 “Very Persistent” (2), (3) 182 days - “Persistent” in soil (4) 365 days - “Persistent” in sediment (4) (1) (Unites States Environmental Protection Agency (US EPA). 1999a. “Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances.” Federal Register. 64(213): 60194-60204.) (2) (United States Environmental Protection Agency (US EPA). 1999b. “Persistent Bioaccumulative Toxic (PBT) Chemicals; Lowering of Reporting Thresholds for Certain PBT Chemicals; Addition of Certain PBT Chemicals; Community Right-to-Know Toxic Chemical Reporting.” Federal Register. 64(209): 58665-58753.) (3) (European Chemicals Bureau (ECB). 2003. “Technical Guidance Document in support of Commission Directive 93/67/EEC on Risk Assessment for new notified substances, Commission Regulation (EC) No 1488/94 on Risk Assessment for existing substances. Direction 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal products on the market. Part II.”) (4) (Environment Canada (EC). 2006. “Exiting Substances Evaluation: Categorization of the Domestic Substances List (DSL).” Internet content available (Oct. 11, 2009) at: http://www.ec.gc.ca/substances/ese/eng/dsl/cat_criteria_process.cfm)
Assigning a Bioaccumulation Score
Referring to FIG. 2 there is shown a process for assigning a bioaccumulation score. The first step is to determine the molecular weight of the ingredient. If the molecular weight exceeds 1000 Daltons, the ingredient is expected to have a low bioavailability and hence a low potential for bioaccumulation (US EPA, 1999). Under these circumstances, a bioaccumulation score of 100 is assigned. If the molecular weight is less than or equal to 1000 Daltons, the possibility of bioaccumulation cannot be ruled out; it is possible to obtain data for the ingredient's bioconcentration factor (BCF) in fish. If reliable empirical data are absent, estimate the BCF using a widely accepted predictive model, such as, for example BCFBAF™, formerly called BCFWIN™. This program estimates fish bioconcentration factor and its logarithm using two different methods. The first is the traditional regression based on log K OW plus any applicable correction factors, and is analogous to the WSKOWWIN™ method. The second is the Arnot-Gobas method, which calculates BCF from mechanistic first principles. BCFBAF™ also incorporates prediction of apparent metabolism half-life in fish, and estimates BCF and BAF for three trophic levels.). In the present examples, the Quantitative structure-activity relationship (QSAR) models from the ECB (2003) were used. The QSAR model, is the process by which chemical structure is quantitatively correlated with a well defined process, such as biological activity or chemical reactivity. For example, biological activity can be expressed quantitatively as in the concentration of a substance required to give a certain biological response. Additionally, when physicochemical properties or structures are expressed by numbers, one can form a mathematical relationship, or quantitative structure-activity relationship, between the two. The mathematical expression can then be used to predict the biological response of other chemical structures.
QSAR's most general mathematical form is:
Activity= f (physiochemical properties and/or structural properties)
TABLE 4
Bioaccumulation Scoring Scale
Fish
Bioaccumulation
BCF
Score
(L/kg)
Regulatory Benchmarks Considered
100
<100
100 L/kg - value below which
75
575
bioaccumulation is ruled out as a concern (1)
50
1050
500 L/kg - described as “low level of
25
1525
bioconcentration (2)
0
≧2000
1000 L/kg - threshold for testing,
exposure control requirements (3)
2000 L/kg - “Bioaccumulative” (4)
5000 L/kg threshold for potential ban (5)
“Very Bioaccumulative” (6)
“Bioaccumulative” (7)
(1) European Commission (EU Comm). 2001. “Commission Directive 2001/59/EC of 6 Aug. 2001 adapting to technical progress for the 28th time Council Directive 67/548/EEC on the approximation of the laws, regulations and administrative provisions relating to the classification, packaging and labeling of dangerous substances.”
(2) United Nations (UN). 2007. “Globally Harmonized System of Classification and Labelling of Chemicals (GHS) Second revised edition.”
(3) United States Environmental Protection Agency, 1999a; “Bioaccumulative”, (US EPA, 1999b)
(4) ECB, 2003 European Chemicals Bureau (ECB). 2003. “Technical Guidance Document in support of Commission Directive 93/67/EEC on Risk Assessment for new notified substances, Commission Regulation (EC) No 1488/94 on Risk Assessment for existing substances. Direction 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal products on the market. Part II.”
(5) US EPA, 1999a; Unites States Environmental Protection Agency (US EPA). 1999a. “Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances.” Federal Register. 64(213): 60194-60204.
(6) (US EPA, 1999b) United States Environmental Protection Agency (US EPA). 1999b. “Persistent Bioaccumulative Toxic (PBT) Chemicals; Lowering of Reporting Thresholds for Certain PBT Chemicals; Addition of Certain PBT Chemicals; Community Right-to-Know Toxic Chemical Reporting.” Federal Register. 64(209): 58665-58753.
(7) Environment Canada (EC). 2006. “Exiting Substances Evaluation: Categorization of the Domestic Substances List (DSL).” Internet content available (Oct. 11, 2009) at: http://www.ec.gc.ca/substances/ese/eng/dsl/cat_criteria_process.cfm
Using the linear scoring scale in Table 4, the BCF is transformed to a bioaccumulation score for the ingredient. If the score is based on an estimated BCF rather than an empirical BCF, reduce the score by an uncertainty penalty (e.g., 5 points).
Assigning a Toxicity Score
Referring to FIG. 3 , one may obtain acute aquatic toxicity benchmarks from three indicator organisms representing one primary producer (e.g., the chemical concentration causing a 50% inhibition in the algae growth rate in a 72-hour study, or an algae EC50), one primary consumer (e.g., the chemical concentration causing immobilization to 50% of a water fla population in a 48-hour study using Daphnia species, or a daphnid EC50), and one secondary consumer (e.g., the chemical concentration in water causing mortality to 50% of a fish population in a 96-hour study, or a fish LC50). If reliable empirical data are absent, estimate the aquatic toxicity benchmarks listed above using a widely accepted predictive model (e.g., The Ecological Structure Activity Relationships (ECOSAR) Class Program which is a computerized predictive system that estimates the aquatic toxicity of industrial chemicals. The program estimates a chemical's acute (short-term) toxicity and chronic (long-term or delayed) toxicity to aquatic organisms such as fish, aquatic invertebrates, and aquatic plants by using Structure Activity Relationships (SARs). Structure Activity Relationships, or SARs, is a technique routinely used by the U.S. EPA Office of Pollution Prevention and Toxics under the New Chemicals Program to estimate the toxicity of industrial chemicals being reviewed in response to Pre-Manufacture Notices mandated under Section 5 of the Toxic Substances Control Act (TSCA). Through publication of ECOSAR, the U.S. EPA provides public access to the same methods the EPA uses for evaluating aquatic toxicity.)
If several benchmarks exist for a single class of aquatic indicator organism (i.e., primary producer, primary consumer, secondary consumer), the lowest L(E)C50 value is selected from a reliable study as the applicable benchmark for that organism. If no acute toxicity occurs at the ingredient's limit of water solubility in all reliable empirical studies (or in the absence of empirical studies, in model predictions), a default toxicity score less than 100 is assigned for that organism (e.g., 70 points) to account for uncertainty regarding the potential for adverse effects to occur over certain circumstances, including longer exposure periods.
Using the linear scoring scale in Table 5 (below), each of the three organism L(E)C50 values (i.e., LC50 or EC50 values) are transformed to an organism-specific toxicity score for the ingredient. If the organism-specific toxicity score is based on an estimated L(E)C50 value rather than an empirical L(E)C50 value, that score is reduced by an uncertainty penalty (e.g., 5 points).
TABLE 5
Toxicity Scoring Scale
Toxicity
Score
L(E)C50 (mg/L)
Regulatory Benchmarks Considered
100
≧100
100 mg/L - Threshold for acute or
75
75
chronic category 3 (1)
50
51
100 mg/L - maximum test concentration
25
26
required in OECD acute aquatic test
0
≦1
guidelines
10 mg/L - Threshold for acute or chronic
category 2 (1)
1 mg/L - Threshold for acute or chronic
category 1 (1); “Inherently Toxic” (2).
(1) United Nations (UN). 2007. “Globally Harmonized System of Classification and Labelling of Chemicals (GHS) Second revised edition.” Internet content available (Oct. 11, 2009) at: http://www.unece.org/trans/danger/publi/ghs/ghs_rev02/02files_e.html
(2) Environment Canada (EC). 2006. “Exiting Substances Evaluation: Categorization of the Domestic Substances List (DSL).” Internet content available (Oct. 11, 2009) at: http://www.ec.gc.ca/substances/ese/eng/dsl/cat_criteria_process.cfm
The overall ingredient toxicity score is determined as the minimum organism-specific toxicity score. If no score could be determined for one class of aquatic indicator organism (i.e., primary producer, primary consumer, secondary consumer), the overall ingredient toxicity score is reduced by an uncertainty penalty (e.g., 5 points). If no score could be determined for two classes of aquatic indicator organisms, the overall ingredient score is reduced by a larger uncertainty penalty (e.g., 10 points).
Environmental Scoring for Ingredients that are Inorganic Compounds
Assigning a Persistence Score
Persistence for inorganic compounds is defined differently than for organic compounds in the present invention. Inorganic compounds and/or their environmental degradants are infinitely persistent and typically naturally-occurring. Hence, the persistence of all of the potentially toxic or bioaccumulative forms (e.g., forms where the bioaccumulation and toxicity scores are less than 100) of the ingredient and its environmental degradants are considered using empirical data from the peer-reviewed literature. The lowest persistence score among the ingredient and its environmental degradants is assigned as the final persistence score. When the ingredient and its potential degradants are not potentially bioaccumulative or toxic (e.g., the bioaccumulation and toxicity scores are not less than 100), the persistence score assigned is 100.
For example, for the personal care product inorganic ingredient, zinc oxide, both the ingredient ZnO and the degradant Zn 2+ are evaluated. Based on empirical data from the peer-reviewed literature, using the toxicity scoring process for organic ingredients above, both are potentially toxic to aquatic organisms with a toxicity score of zero. As a result, the environmental half-life of ZnO and Zn 2+ are evaluated using empirical data from the peer-reviewed literature. Both forms can persist for long periods of time water, sediment, and soil under certain conditions, and using the persistence scoring scales for organic ingredients in Table 1 and Table 3, a persistence score of zero results.
Assigning a Bioaccumulation Score
An empirical BCF in fish and/or evidence from the peer-reviewed scientific literature are used to determine the Bioaccumulation score. If an empirical value for BCF in fish is available, the Bioaccumulation scoring scale in Table 4 is used to determine a tentative Bioaccumulation score. However, some inorganic chemicals appear to bioconcentrate only when they are present in low environmental concentrations, because they are essential nutrients, and organisms preferentially absorb the chemical. The peer-reviewed scientific literature must be consulted for evidence of adverse bioaccumulation effects and/or a false indication of bioaccumulation concerns due to a high BCF value determined for essential nutrients at low environmental concentrations.
For example, for the personal care product inorganic ingredient, zinc oxide, the 2001 World Health Organization International Programme on Chemical Safety Environmental Health Criteria 221 “Zinc” stated: “In the case of zinc, the BCF is not useful for relating uptake to adverse effects, because it does not consider physiological parameters . . . . The fact that zinc, as an essential metal, is naturally concentrated by living organisms means that the BCF for zinc bears no relationship to toxicity. Bioaccumulation does not differentiate between zinc adsorbed to the outer surface of organisms, and the zinc within organisms. Rapid bio-inactivation of zinc, for instance compartmentation into vacuoles, may result in elevated BCFs with no difference in the health of the organism . . . . Further, the fact that many organisms are capable of regulating internal zinc concentrations within certain limits means that these organisms can stabilize internal concentrations against perturbations or high concentrations in the external environment . . . . Accumulation of zinc to meet physiological requirements can be mistaken for trophic transfer. However, zinc is not biomagnified . . . .” Based on this information published by a reputable source indicating that there is no concern for adverse environmental effects due to bioaccumulation, zinc oxide was assigned a Bioaccumulation score of 100, independent of any empirical BCF values available in the peer-reviewed literature.
Assigning a Toxicity Score
The process used for ingredients that are organic compounds is also used for ingredients that are inorganic compounds with the following exceptions: (1) only empirical data are considered, as models for predicting the aquatic toxicity of metals are not widely available; (2) the toxicity of the ingredient and all plausible environmental degradants are calculated. The lowest Toxicity score among the ingredient and its plausible environmental degradants is assigned as the final Toxicity score for the ingredient.
Assigning a PBT Score for Inorganic Ingredients and Organic Ingredients that are not Readily Biodegradable
A numeric weight value for each of the persistence (P), bioaccumulation (B), and toxicity (T) categories is assigned, such that the sum of weights is 100%. The assigned weight indicates the relative importance of the category (i.e., P, B, or T), and can be changed depending on the potential adverse environmental effects most heavily targeted for reduction. In accordance with the present invention, the assigned weights are 50% P, 25% B, and 25% T for ingredients that are organic compounds. The category weight is multiplied by the category score for each category (i.e., P, B, and T) and the overall PBT score for the ingredient is the sum of the category weight multiplied by category score for each category according to the following Equation 1.
Score PBT =Σ i=1 i w i ·Score i Equation 1
where
Score PBT =ingredient's PBT score
w i =category weight for category i where i=P, B, or T
Score i =ingredient's category score for category i where i=P, B, or T
and where
Σ i=1 3 w i =100%
Assigning a PBT Score for Inorganic Ingredients and Organic Ingredients that are Readily Biodegradable
When an ingredient is readily biodegradable, it is expected to rapidly and completely degrade in a sewage treatment plant and/or in the environment. As a result, the relative importance of the Bioaccumulation and the Toxicity scores is different for readily biodegradable ingredients than for ingredients that are not readily biodegradable. Specifically, toxicity is important in a limited spatial extent around the discharge point of a sewage treatment plant operating with a low treatment efficiency, or where wastewater is discharged without treatment. Bioaccumulation is not expected to be important. As a result, the PBT score is assigned differently for readily biodegradable ingredients in the present invention.
Toxicity Considerations for Readily Biodegradable Ingredients
Toxicity can be important, but to a limited spatial extent. A compound that is readily biodegradable can be present in sewage treatment plant (STP) discharges. A readily biodegradable compound can take as long as 28 days to completely degrade in a lab test, but STPs have much shorter hydraulic retention times, on the order of hours, albeit with more favorable conditions for degradation than the ready biodegradability laboratory test.
Hence, in the vicinity of an STP, particularly one operating with performance low treatment efficiency, or in communities where wastewater is not treated, there could be a continual load of a readily biodegradable compound to a receiving water. In that vicinity, wildlife would be exposed to the readily biodegradable compound. If the receiving water is a river, the compound's concentration will decrease with distance downstream due to biodegradation and other processes (e.g., dilution), so that exposure and the possibility for toxic effects decrease, eventually to zero.
In the present invention, the Toxicity component of the PBT score for readily biodegradable ingredients is retained with a weight of 25%, because it is preferable to use an ingredient of low toxicity to protect against the possibility that exposure will occur in a limited spatial extent around an STP or near a raw wastewater discharge.
Bioaccumulation Considerations for Readily Biodegradable Ingredients
Bioaccumulation is much less likely a concern than toxicity for a readily biodegradable compound, because of the limited spatial extent exposure would occur. For example, a fish's forage range (the area over which the fish swims and eats) can be much larger than the limited area of influence adjacent to and downstream from discharges containing the readily biodegradable ingredient.
As a result, when a compound is readily biodegradable, in the present invention, the following is done: (1) Assign a Persistence score of 100 (or 95 if a model was used in lieu of empirical data) (2) Use component weighting factors such as 75% for Persistence, 0% for Bioaccumulation, and 25% for Toxicity to reflect the diminished importance of bioaccumulation for readily biodegradable ingredients and calculate the PBT score as described in Equation 1, and (3) Determine the BCE If the BCF cannot be determined or if the BCF would result in a Bioaccumulation score of zero, a penalty (e.g., 5 points) is taken off the final PBT score. The rationale for the penalty is that there is some uncertainty about whether bioaccumulation can be completely ruled out for high-BCF compounds in the limited area of influence adjacent to and downstream from discharges containing the readily biodegradable ingredient.
Assigning a Final Environmental Performance Score for All Ingredients
The PBT score is the final environmental performance score, barring other environmental concerns. In the present invention, four categories of other environmental concerns are evaluated for every ingredient scored. If other environmental concerns are identified, the PBT score is reduced by a penalty, with the total penalty not to exceed some threshold point value (e.g., 25 points), determined to reflect the importance of the issues addressed by the penalties relative to Persistence, Bioaccumulation, and Toxicity.
Assessing Penalties to the PBT Score
Photochemical Smog-Forming Volatile Organic Compound (VOC) Penalty
The Photochemical Smog Forming VOC penalty accounts for the potential for ingredients that are VOCs to contribute to ground-level ozone formation (i.e., photochemical smog). The Statewide Air Pollution Research Center (SAPRC) developed quantitative measures for the ozone forming potential of a chemical, for use in air quality simulation models approach was developed for prevailing atmospheric conditions in California. The SAPRC approach assigns Maximum Incremental Reactivity (MIR) values for chemicals and chemical classes. A higher MIR value indicates a more reactive compound with a greater tendency to form ground level ozone.
In the present invention, in order to qualify for the photochemical smog-forming VOC penalty, an ingredient must be a volatile organic chemical (VOC), defined as having a boiling point less than 250° C., and it must have been assigned a positive value for the maximum incremental reactivity (MIR). In the present invention, all qualifying ingredients are assessed equal penalties (i.e., 5 points). Optionally, a numeric MIR value screening value greater than zero (e.g., 5.0 grams ozone per gram VOC) can be applied to assign different point penalties depending on the tendency of the ingredient to cause the formation of ground-level ozone. A lower penalty (e.g., 3 points) can be applied for qualifying ingredients with a MIR value less than the screening value, and a higher penalty (e.g., 6 points) can be applied for qualifying ingredients with a MIR value greater than the threshold. The present invention does not apply a MIR screening value greater than zero because the MIR values have not yet undergone a comprehensive technical peer review.
Potent Chronic Toxicity Penalty
A chemical's toxic potency to aquatic organisms is determined in laboratory exposures over short periods of time (acute tests) or long periods of time (chronic tests), relative to the life span of the organism. A chronic, or long-term, exposure to a low concentration of personal care products in water is the most probable environmental exposure scenario. Hence, chronic test results are most relevant for the environmental performance score. However, information on the chronic toxicity of ingredients in personal care products is rarely available. Normally, the acute toxicity of a chemical (i.e., L(E)C50) is proportional to the chronic toxicity of the chemical, with a ratio usually less than 1000. Therefore, the L(E)C50 is a useful surrogate for chronic effects when used to compare similar chemicals. The use of L(E)C50 values as a surrogate for comparison purposes fails where the chemical is highly reactive with a specific biological system so that adverse effects occur at extremely low environmental concentrations.
In the present invention, the Potent Chronic Toxicity Penalty is used for ingredients that have been clearly identified in the scientific literature as capable of eliciting adverse effects at low concentrations in the environment due to endocrine disruption, but have not yet been identified as such by regulatory authorities (ingredients identified as endocrine disruptors by regulatory authorities are penalized as part of the Regulatory List Penalty described below). In the present invention, this penalty accounts for potential environmental (i.e., not human health) effects of ingredients that have been shown to elicit estrogen-like effects to fish. Feminization of fish has been observed in natural waters, and is a cause of concern among regulators, non-governmental organizations, and the public. Chemicals with estrogen-like activity can cause the feminization of male fish leading to population declines.
In order to qualify for the Potent Chronic Toxicity Penalty, peer-reviewed scientific literature must show that the ingredient elicits adverse aquatic effects to wildlife at lower concentrations than would be expected based on the L(E)C50 value (assuming an acute-to-chronic ratio of 1000). In the present invention, all qualifying ingredients are assessed a single numeric penalty (e.g., 5 points). Optionally, qualifying ingredients can be assessed a penalty proportionate to the additional toxic potency demonstrated in chronic tests, relative to the chronic toxic potency suggested by the minimum L(E)C50 value divided by the typical maximum acute-to-chronic ratio of 1000.
Formation of Toxic Metabolites Penalty
Some chemicals degrade in sewage treatment plants (STPs) or the environment to form metabolites having a toxic potency greater than that of the chemical originally discharged to the STP or the environment.
In accordance with the present invention, the Toxic Metabolites Penalty is used for some types of ethoxylated surfactants, which are a particular category of compounds widely identified as a concern for the aquatic environment by scientists, regulatory authorities, and non-governmental organizations. Certain ethoxylated surfactants can undergo rapid primary biodegradation, but can form more persistent and toxic alkylphenol ethoxylate (APE) compounds.
In order to qualify for the Formation of Toxic Metabolites Penalty, peer-reviewed scientific literature must show that the ingredient is degraded in STPs or the environment to form metabolites that are more potent toxicants to wildlife than the ingredient. In the present invention, all qualifying ingredients are assessed a single numeric penalty (e.g., 5 points). Optionally, qualifying ingredients can be assessed a penally proportionate to the additional toxic potency of metabolites compared to the ingredient from which they were formed.
Regulatory List Penalty
Some chemicals have been identified as causing adverse environmental effects for reasons not addressed in the PBT score or in the three penalty categories described above. For example, chemicals that deplete stratospheric ozone were identified in the Montreal Protocol on Substances That Deplete the Ozone Layer. The European Commission published a database on candidate endocrine disruptors (http://ec.europa.eu/environment/endocrine/strategy/substances_en.htm) in which chemicals were assigned to Category I or Category II if empirical evidence existed for endocrine disruption effects.
In order to qualify for the Regulatory List Penalty, an ingredient must be identified on a regulatory list due to environmental hazards not already addressed in the PBT score or in the three penalties listed above. In the present invention, all qualifying ingredients are assessed a single numeric penalty (e.g., 5 points). Optionally, qualifying ingredients can be assessed a penalty proportionate to the number and severity of additional hazards identified by regulatory authorities. To assign the final environmental performance score for an ingredient, the final score is equal to the PBT score minus the sum of all penalties assessed.
In accordance with another embodiment of the invention, color codes may be assigned to the ingredients based on the final environmental performance scores. Color codes can be used to assist with the interpretation of numeric scores. In a preferred embodiment a first color is associated with an ingredient having an environmental score between 100-80, a second color is associated with an ingredient having an environmental score between 79-61 and a third color is associated with an ingredient having an environmental score 60-0 and wherein the first, second and third colors are all different. In a most preferred embodiment, the color codes are:
Green—Meaning that little to no environmental hazard is associated with the ingredient. Ingredient is preferred for use (e.g., environmental performance score 100-80).
Yellow—Meaning that low to moderate environmental hazard is associated with this ingredient. These ingredients are acceptable for use unless a Green alternative can be substituted. (e.g., environmental performance score 79-61)
Red—Meaning that this ingredient might potentially present an environmental hazard and should be avoided if possible (e.g., environmental performance score 60-0).
To assign the environmental performance score for a finished product, the following values are calculated for each non-water ingredient in the finished product:
1. Water-Included Weighting Factor=the weight fraction of the ingredient in the finished product. 2. Water-Excluded Weighting Factor=Water-Included Weighting Factor of the ingredient/(1−Water-Included Weighting Factor of water). 3. Scored Ingredients Only Weighting Factor=for non-water ingredients in the finished product for which environmental performance scores have been determined only: Water-Excluded Weighting Factor/Fraction of Non-Water Ingredients Scored. 4. Weighted Scores.
a. Water-Included Minimum Weighted Score=Water-Included Weighting Factor×ingredient environmental performance score (0 for unscored ingredients). b. Water-Included Maximum Weighted Score=Water-Included Weighting Factor×ingredient environmental performance score (100 for unscored ingredients) c. Water-Excluded Minimum Weighted Score=Water-Excluded Weighting Factor×ingredient environmental performance score (0 for unscored ingredients) d. Water-Excluded Maximum Weighted Score=Water-Excluded Weighting Factor×ingredient environmental performance score (100 for unscored ingredients) e. Scored Content Only Ingredient Score=Scored Ingredients Only Weighting Factor×ingredient environmental performance score (0 for unscored ingredients)
The following values are calculated for the finished product:
1. Fraction of Non-Water Ingredients Scored=for all non-water ingredients having an environmental performance score in the finished product, the sum of the Weight Fraction of Ingredient in Finished Product 2. Water-Included
a. Water-Included Minimum Possible Score=sum of all ingredient Water-Included Minimum Weighted Score values b. Water-Included Maximum Possible Score=sum of all ingredient Water-Included Maximum Weighted Score values
3. Water-Excluded
a. Water-Excluded Minimum Possible Score=sum of all ingredient Water-Excluded Minimum Weighted Score values except the value for water b. Water-Excluded Maximum Possible Score=sum of all ingredient Water-Excluded Maximum Weighted Score values except the value for water c. Finished Product Scored Content Only Score=sum of all Scored Content Only Ingredient Score values
The Finished Product Scored Content Only (FPSCO) Score is the weighted score for all scored non-water ingredients in the product, and is one indicator of the environmental preferability of the formula. The Water Excluded Minimum Possible Score and Water Excluded Maximum Possible Score bracket the uncertainty around the FPSCO Score as the scored content increases to 100% and is a second indicator of the environmental preferability of the formula.
Compare the FPSCO Scores. The formula with a higher FPSCO score is tentatively selected as the environmentally preferable alternative. When FPSCO Scores are similar for several formulas (e.g., within 5 points of each other), the scores can be considered a “tie.” A scoring difference within a certain threshold (e.g., five points) can be considered negligible, because of uncertainty in the scores. Uncertainty in environmental performance scores arises from practices such as using short-term laboratory test results to estimate long-term effects in the environment, and using information about an ingredient's toxicity to only a few types of organisms as a way to estimate effects on all forms of wildlife. To break ties, or to confirm a tentative formula selection, evaluate additional scoring metrics.
Consider uncertainty in the FPSCO Scores caused by the use of ingredients for which no environmental performance scores have been assigned. For example: Formula A has an FPSCO Score of 100, but only 10% of the ingredients in Formula A has environmental performance scores assigned, leading to a high degree of uncertainty in the “true score” that would result if the remaining 90% of the formula had environmental performance scores assigned; in contrast, Formula B has a “Final” score of 85, but much more of Formula B—80% of the ingredients—has environmental performance scores assigned. In this case, the “Final” score for Formula B is lower than for Formula A, but there is much less uncertainty in the environmental safety of Formula B. This uncertainty can be understood using Water Included Minimum Possible Score and Water Included Maximum Possible Score, which bracket the uncertainty around the FPSCO Score as the scored content increases to 100%. The Water Excluded Minimum Possible Score is the FPSCO Score that would result if all the unscored ingredients were assigned a score of zero. The Water Excluded Maximum Possible Score is the FPSCO Score that would result if all the unscored ingredients were assigned a score of 100.
In some cases, it will be preferable to select a formula with a lower FPSCO Score, if that formula's Water Excluded Minimum Possible Score is substantially higher than for alternative formulas being considered. For example, the Water Excluded Minimum Possible Scores for Formulas A and B (above) are 10 and 68, respectively. As a result, Formula B is preferable because its score is in the “green” range, and the worst possible FPSCO Score it could receive if all its ingredients were assigned environmental performance scores is in the “yellow” range. In contrast, it is possible that Formula A would receive an FPSCO Score in the “red” range if all of its ingredients were assigned environmental performance scores, because its Water Excluded Minimum Possible Scores score is 10.
Environmental Scoring Process—Example: Glycerin (Glycerol)
Persistence Considerations
1. Partitioning Determined in EPI Suite Level IR Fugacity Model
5% threshold not reached in sediment, soil, air, hence only persistence in water considered
2. Ready Biodegradability Data
Readily biodegradable according to empirical studies Persistence score=100
Bioaccumulation Considerations
1. Molecular weight (i.e., bioavailability) check
Less than 1000 g/mol threshold, hence the possibility of bio accumulation concerns cannot be ruled out
2. Fish bioconcentration factor (BCF) check needed
Empirical fish BCF: not available Modeled fish BCF uses empirical octanol-water partition coefficient
Results in BCF much less than the 5,000 L/kg threshold of concern for readily biodegradable ingredients
Bioaccumulation score=100
Aquatic Toxicity Considerations
1. Empirical data from acute studies available for all three trophic levels
Invertebrate/Primary Consumer—water flea, 50% immobilization (EC50) Vertebrate/Secondary Consumer—fish, 50% lethality (LC50) Aquatic Plant/Primary Producer—algae, 50% inhibition in growth rate (EC50)
2. Benchmarks translated to scores
Invertebrate EC50=10,000 mg/L, hence score=100 Fish LC50=5,000 mg/L, hence score=100 Aquatic Plant EC50=46,000 mg/L, hence score=100 Toxicity score=100 (i.e., minimum of three scores above—no penalties assessed for missing trophic levels or use of modeled data in lieu of empirical data)
Final Ingredient Score
1. PBT Score
P: 100×75% weight B: <5000—no penalty T: 100×25% weight
2. Additional Considerations (Potential Reductions to PBT Score)
Photochemical Smog-Forming VOC Penalty—NO Potent Chronic Toxicity Penalty—NO Formation of Toxic Metabolites Penalty—NO Regulatory List Penalty—NO Final Score=100 (i.e., 100−0)
In another preferred embodiment, the environmental score for an ingredient would incorporate information on an even wider array of issues associated with environmental sustainability. The present method develops environmental scores for ingredients and formulations and encourages formulators to move toward more environmentally preferred ingredients and formulations. The methods described above may be utilized to track and improve the environmental performance of a company, business unit, product line, brand, product function (e.g., shampoo, lotion), or product type (e.g., rinse off, leave on) by using the environmental scores for ingredients or finished products in metrics derived from those scores to show trends in environmental performance over time and identify organization-wide formulation changes needed to improve future environmental performance including:
(1) Evaluating the environmental scoring profile of the ingredients sold in a product portfolio by combining the mass of all ingredients sold across all products in an organization; treating the list of ingredients and their masses sold as a single master formula; determining the environmental score of the master formula; setting a goal to achieve an improvement in the environmental score of the master formula over a certain time interval by intentionally replacing lower-scoring ingredients with higher-scoring ingredients in new or reformulated products, or (2) Measuring the total mass of each low-scoring ingredient (i.e., ingredients for which the environmental score is below a certain threshold score) sold during a certain period of time; setting a goal to reduce the use of low-scoring ingredients by a certain amount or percent over a certain period of time; optionally prioritizing lower-scoring, higher-volume ingredients for replacement by higher-scoring substitutes using a score-normalized mass value to rank all low-scoring ingredients in order of priority for potential replacement where:
score - normalized mass = mass sold environmental score
and where a higher score-normalized mass value indicates a higher priority for substitution, or
(3) Setting targets for finished product scores for an organization's top selling products, such that at certain time intervals, the finished product scores are calculated for the individual products that comprise a certain percent of the organization's total sales; any of these products for which the score is less than a certain threshold score are targeted for reformulation to improve the score above the threshold.
|
Disclosed are methods for developing a product having a relatively benign environmental impact. The methods evaluate the environmental hazard of various chemical components in formulated products and identify improvements in environmental safety based on those evaluations. Environmental criteria are in part developed based on three factors including; persistence, bioaccumulation and toxicity. One method includes obtaining a preliminary formula for a product, wherein the preliminary formula includes a plurality of chemical components, identifying at least one different chemical component that is capable of being substituted for the chemical component in the preliminary formulation and determining an environmental performance score for the chemical component and the different chemical component and determining an environmental performance score of the preliminary formula and a second formula, wherein the second formula utilizes the different chemical component. The formula having the highest environmental performance score is selected as the product. A second method includes tracking the use of chemical components in an existing product portfolio offered or sold by a business unit or a company, in which existing products having the lowest environmental performance scores would be targeted for replacement by reformulated products having higher environmental scores in order to improve the environmental performance of the business unit or company.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119 of a provisional application Ser. No. 61/155,742 filed Feb. 26, 2009, which application is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and method for repairing pipe, such as underground sewer pipe and the like.
Prior methods for repairing damaged sections of pipe include moving a liner tube impregnated with a resinous material capable of curing and hardening to a position within the pipe where the damaged portion is located. Once the liner tube is positioned within the host pipe, it is pressurized, causing the liner to press against the interior wall of the host pipe, and the liner is cured by applying heat, such as with steam or hot water. These liners can also be cured at ambient temperatures by a chemical mixture which generates an exothermic reaction or by ultraviolet light. The liner tube forms an interior liner in the pipe for the pipeline being repaired. Such a process is commonly known as cured-in-place pipelining.
The liner tube is positioned within the pipe by pulling, pushing or inverting the liner. Pulling or pushing a liner into position within a pipe can be an efficient process, particularly in situations where the liner must only travel a short distance and need not navigate significant bends in the pipe. Typically, a flat sheet liner is wrapped around an inflation plug to form a tube with the longitudinal edges of the sheet overlapping. The inflation plug with liner is then pushed or pulled into position adjacent the damaged section of pipe.
Although a pull-in-place or push-in-place installation is feasible in many instances, problems remain. For example, prior art lining tubes are typically made of a fabric material that is resin absorbent. Once the resin is applied to the liner, there is nothing around the outside of the liner to contain the resin. Consequently, resin is wiped off of the liner when the liner rubs against the interior of the host pipe as the liner is either pulled or pushed into position. Workers must also take great care so as to not come into contact with the resin and also avoid contaminating the exposed resin impregnated liner.
Prior art liners pushed or pulled in place are also not well suited for lining at bends in the pipeline. Flat sheet liners with overlapping edges are not capable of stretching or expanding sufficiently to avoid folds in the liner when pressed against the interior of the host pipe. In addition, flat sheet style liners must be banded, strapped, tied or otherwise attached with fasteners to the inflation plug to avoid falling off the plug prior to inflating the plug and pressing the liner against the interior of the host pipe.
In light of the foregoing, the primary objective of the present invention is to provide an improved method and apparatus for lining pipe.
Another objective of the present invention is to provide a new resin absorbent liner that contains the resin in the liner prior to stretching the liner and pressing it against the interior of the host pipe.
Another objective of the present invention is to provide a new lining apparatus for pull-in-place or push-in-place applications that prevents resin from being wiped off of the liner as it is moved into the pipe, yet allows the resin to contact the interior of the host pipe once the liner is expanded or stretched under pressure.
Another objective of the present invention is to provide a new lining apparatus and method for effectively lining at bends and turns in the pipeline.
A still further objective of the present invention is to provide a new lining apparatus which is economical to manufacture, durable in use and efficient in operation.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, an apparatus for repairing a damaged portion of a pipe is provided. The apparatus includes a liner with a tubular sleeve of a resin absorbent material that is capable of being stretched circumferentially and a plastic film disposed on an exterior surface of the sleeve. Once the liner is impregnated with a resinous material, the plastic film contains the resin and prevents the resin from being wiped off of the liner while outside of the pipe and as the liner is being moved to an operative position adjacent the damaged section of pipe in need of repair. Stretching the liner circumferentially toward the damaged section of pipe breeches the integrity of the plastic film to expose the resinous material and tubular sleeve to the damaged section of the pipe.
In a preferred form of the invention, the plastic film is a TPU or like polymer film with a wall thickness of approximately 1-2 mils that is laminated to the sleeve. The preferred tubular sleeve is also capable of being stretched to a diameter of at least approximately 100% greater than its non-stretched diameter. Allowing the sleeve to stretch to such an extent allows the sleeve to conform to the shape of the pipe even at bends and curves in the pipeline without creating undesirable folds in the liner.
Another aspect of the invention is a new method of lining a damaged section of pipe using a liner having a tubular sleeve of resin absorbent material and a plastic film laminated to an exterior surface of the sleeve. The liner is impregnated with a resinous material capable of curing and hardening. The liner is moved into the pipe to a position adjacent the damaged section of the pipe. Once in position, the liner is stretched circumferentially toward the damaged section of pipe to thereby breech the integrity of the plastic film and expose the resinous material in the tubular sleeve to the damaged section of the pipe. The liner is pressed against the damaged section of a pipe, allowing the resinous material to cure and harden.
In a preferred form of the method, the liner is positioned on an inflatable plug with a substantially non-stick bladder material located therebetween. The tubular non-stick bladder material is banded to the front end of the inflatable plug such that the bladder material peels away from the cured liner as the inflatable plug is removed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a liner from a preferred embodiment of the present invention.
FIG. 2 is a sectional view of the liner in FIG. 1 taken along line 2 - 2 in FIG. 1 .
FIG. 3 is a sectional view of the preferred liner of the present invention ready for impregnation of a thermal-set resin using a vacuum process.
FIG. 4 is a schematic view showing the vacuum impregnation process.
FIG. 5 is a perspective view of the preferred liner mounted on an inflatable plug.
FIG. 6 is a cross-sectional view of the device shown in FIG. 5 taken along line 6 - 6 in FIG. 5 .
FIG. 7 is a schematic view illustrating a preferred method of the present invention for repairing a portion of a damaged pipeline extending between two manholes.
FIG. 8 is a sectional view at the damaged section of pipe after the liner has been stretched and pressed against the interior of the pipe.
FIG. 9 is a sectional view similar to FIG. 8 , showing the liner pressed against a bend in the pipeline.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a perspective view of a preferred liner 10 of the present invention. The liner 10 is formed by a tubular sleeve 12 including a fabric fiber material which can preferably be stretched circumferentially up to at least approximately 100% of its non-stretched diameter. The sleeve 12 is preferably formed from a sheet of material stitched about its longitudinal edges. A preferred fabric for the sleeve 12 is a material known as “stitch bond” distributed by LMK Enterprises, Inc. of 1779 Chessie Lane, Ottawa, Ill. 61350.
The preferred liner 10 also includes a plastic film 14 laminated to an exterior surface of the tubular sleeve 12 . The preferred plastic film 14 has a thickness of approximately 1-2 mils and is made of TPU, but could be made of PVC or a similar polymer film. The plastic film 14 is cured and then laminated to the sleeve 12 using an adhesive or glue as is known in the art.
The sleeve 12 is impregnated with a resin, preferably a thermal-set resin, which is forced into the fabric fibers. A method of impregnating the sleeve 12 with the resin is shown in FIGS. 3 and 4 . More particularly, the fabric fibers of the sleeve 12 are on the inside of the sleeve with the plastic film 14 on the exterior of the sleeve 12 . One end of the sleeve 12 is connected to a vacuum bag using tape or other adhesive. The opposite end of the vacuum bag 16 is connected to a vacuum hose 18 through a threaded coupling 20 . The vacuum hose 18 is connected to a vacuum source 22 , as seen in FIGS. 3 and 4 . A wick 24 extends through the length of the vacuum bag 16 and functions to expel air from the sleeve 12 during the resin impregnation process.
As shown in FIG. 4 , a slug 27 of resin is introduced into the open end of the sleeve 12 and is forced through the sleeve so as to impregnate the fabric fibers. A pipe 26 may be rolled over the sleeve 12 so as to push the resin 27 through the sleeve. Simultaneously or alternatively, the vacuum source 22 can be activated to pull the resin slug 27 through the sleeve 12 , thereby coating and impregnating the fabric fibers with the resin. After this resin impregnation process is completed, the sleeve 12 is in the form of a flattened tube with the plastic film 14 still on the outside and the resin coated fibers on the inside. As an alternative to the vacuum impregnation process, the resin can be poured into the liner tube and then pressed into the fibers by a person or other means in a manual impregnation process.
Once the liner 10 is impregnated with resin, the plastic film 14 on the outside of the sleeve 12 helps to contain the resin and prevent it from being wiped off or coming into contact with persons or objects prior to stretching the sleeve 12 and pressing the liner 10 against the interior of host pipe at the damaged section of pipe. The plastic film 14 is very thin to begin, preferably 1-2 mils thick. As the sleeve 12 stretches or expands radially outwardly, the plastic film 14 becomes even thinner and eventually the stretching of the sleeve 12 breeches the structural integrity of the plastic film 14 , which becomes extremely porous. This unique characteristic of the plastic film 14 helps contain the resin in the liner 10 prior to stretching the tubular sleeve 12 and pressing the liner 10 against the damaged section of pipe.
The liner 10 is preferably installed in the pipe by using an inflatable plug. Inflatable plugs normally include an inflatable rubber sleeve secured between end plates. Inflatable plugs for installing cured-in-place liners are well known in the art. For example, push-type and pull-type inflatable plugs are available from Logiball, Inc. of 440 Papin Street, Quebec, QC G1P3 T9 and 21 Long Pond Road, Jackman, Me. 04945. Push-type inflatable plugs are often used when the liner must only be moved a relatively short distance within the pipe or there is no convenient downstream manhole or other access point from which to pull in the plug. For example, a push-type inflatable plug may be used to push a liner through a cleanout and into a lateral sewer pipe for a spot repair on a damaged portion of the lateral pipe. A rigid hose assembly can be used to push the inflatable plug with liner through the pipe, as is known in the art. Alternatively, an air hose with fiberglass push rod disposed therein can be used. The fiberglass push rod provides for greater stiffness when pushing the plug long distances, and the push rod can be sized so as to allow for air to pass through the hose and inflate the plug. A sealing gland with O-ring allows the hose with rod to slide forward within the plug into contact with the leading end of the plug, which aids in pushing the plug through the pipe. Similarly, the hose with rod can be pulled back until stopped by a retaining ring at the opposite end of the plug, which aids in pulling the plug out of the pipe after installation of the liner.
After the liner 10 has been “wet out” with resin, the liner is pulled over an inflatable plug 28 . A liner 10 mounted on the inflatable plug 2 is shown in FIG. 5 . The elastic properties of the liner 10 allow it to stay in place on the inflatable plug 28 without the use of bands, straps, strings or other fasteners.
A cross-sectional view of the assembly in FIG. 6 shows a tubular sleeve of non-stick bladder material 30 disposed between the inflatable plug 28 and the liner 10 . The purpose of the non-stick sleeve of bladder material 30 is to facilitate removal of the plug 28 after the liner 10 has cured and hardened in the pipe. The non-stick bladder material is preferably formed from a fiber reinforced non-stick plastic material, which includes a scrim reinforcing fabric coated with a translucent or semi-transparent thermo plastic elastomer, such as a thermo plastic polyolefin (TPO) or vulcanizate (TPUV). The preferred non-stick bladder material is disclosed in application Ser. No. 12/026,209, the contents of which are incorporated herein by reference.
The non-stick sleeve 30 is preferably attached to the inflation plug 28 by banding a non-stick sleeve to the front end of the plug. Banding the non-stick sleeve 30 to the front end of the plug 28 maintains the non-stick sleeve in place as the inflatable plug is pulled or pushed into position along the pipe. Banding only at one end also causes the non-stick sleeve 30 to invert during removal of the inflation plug 28 , which facilitates separation of the non-stick sleeve 30 from the liner 10 once the liner is cured and hardened in the pipe.
FIG. 7 shows a sectional view of a main sewer pipe 32 in communication with an upstream manhole 34 and downstream manhole 36 . To perform a spot repair in a main sewer pipe 32 using a pull-in-place process, the inflatable plug 28 with liner 10 is introduced into the main pipe through one of the manhole openings. The plug 28 is drawn into the pipe 32 by means of a winch cable attached to the front end of the plug and extending through an upstream manhole or other access point. As the inflatable plug 28 with liner 10 moves through the pipe 32 , the plastic film 14 prevents the resin from wiping off on the pipe.
Once the inflation plug 28 with liner 10 is moved into operative position adjacent the damaged section of pipe, the inflation plug is inflated with air or other liquid under pressure from a convenient fluid source, causing the liner to stretch radially outwardly toward the interior of host pipe. Stretching the liner 10 breeches the structural integrity of the plastic film 14 on the outside of the sleeve 12 . This allows the resin and sleeve 12 to become exposed to the host pipe. The liner 10 continues to stretch under pressure and is pressed against the interior of the host pipe, allowing the liner to cure and harden. The inflation plug 28 remains inflated while the resin cures. Upon curing of the resin, the liner 10 is bonded and mechanically adhered to the interior of the pipe 32 . The expansion of the inflatable plug 28 assures that no angular spaces reside between the liner 10 and the host pipe. Also, the stretching of the sleeve 12 from a first unstretched diameter to an enlarged diameter matching the contours of the interior of the host pipe precludes undesirable folds in the liner 10 . The liner 10 is preferably sized to stretch in the pipe to a diameter at least 50% greater than the pre-inflation diameter. In a most preferred form, the liner 10 is sized approximately half of the internal diameter of the host pipe. The liner 10 should stretch such that it conforms to the shape of the pipe without folds in the liner. Stretching the sleeve 12 also enables the liner 10 to be used at bends or turns in the pipe. This is illustrated in FIG. 9 .
After the resin cures, the inflation plug 28 is deflated and removed from the cured liner 10 . Removing the inflation plug 28 causes the non-stick sleeve 30 to invert and pull away from the interior of the cured liner 10 .
FIG. 8 is a sectional view of the lining apparatus with the inflatable plug 28 inflated, pressing the liner 10 against the host pipe. As illustrated in FIG. 8 , the plastic film previously on the outside of the sleeve has lost its structural integrity and becomes part of the resin/liner material mechanically adhered to the host pipe.
Although FIGS. 7 and 8 illustrate a pull-in-place style installation, persons skilled in the art having the benefit of this disclosure will recognize that the lining methods and apparatus disclosed herein are also applicable to push-in-place installations.
The invention has been shown and described above with reference to the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention.
|
A new apparatus for repairing a damaged portion of a pipe includes a liner having a tubular sleeve of resin absorbent material that is capable of being stretched circumferentially and a plastic film laminated to an exterior surface of the sleeve. The plastic film contains resinous material in the liner until the liner is stretched circumferentially to thereby breech the integrity of the plastic film and expose the resinous material to a damaged section of pipe in need of repair. A method of lining a damaged section of pipe using the liner is also provided.
| 5
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application 60/700202, filed Jul. 18, 2005.
TECHNICAL FIELD
[0002] This invention relates to novel electrochemical separation methods for the conversion of oxidizing agents to other, more useful oxidants and value-added co-products.
BACKGROUND OF THE INVENTION
[0003] Oxidizing agents have a broad range of applications in the chemical, environmental, medical and consumer products industries, to name but a few. Permanganates, in particular, are used in a wide variety of applications, including in the oxidation of organic compounds in synthesis reactions, destruction of organics and other species in air and water treatment processes, detoxification and bleaching processes, surface treatments for metals, other substrates, and so on. Of the permanganate salts, potassium permanganate (KMnO 4 ) stands out as one of the most widely used. Methods of producing are principally chemical routes.
[0004] Potassium permanganate, however, has more limited solubility properties than other permanganate salts. Aqueous solutions of potassium permanganate are achievable only in a range of 5 or 6 percent-by-weight at room temperature. Solubilities of >40 percent-by-weight in aqueous solution are achievable with non-potassium permanganate salts, such as sodium, calcium and magnesium permanganates. Hence, the more soluble non-potassium permanganate salts are commercially desirable chemicals, and are often necessary.
[0005] Non-potassium permanganate salts are not readily available from native ores. Still, a number of methods have been described for their manufacture from readily available potassium permanganate. The first involves the so called “hexafluorosilicate method” for making sodium permanganate. While this chemical method is effective in the production of sodium permanganate, disadvantages include the generation of large quantities of an insoluble salt by-product, potassium fluorosilicate, which must be disposed or further treated. The cost of disposal and the loss of potassium values from the starting permanganate render the process less attractive.
[0006] A further method by Kotai and Bannerji disclosed in Synth. React. Inorg. Met. - Org. Chem., 31(3), 491-495 (2001) relates to the preparation of aluminum and barium permanganates from the reaction of potassium permanganate and aluminum sulfate in aqueous solution, and further reaction of aluminum permanganate with excess barium hydroxide to form barium permanganate in high purity. The by-products of aluminum sulfate, aluminum hydroxide and barium sulfate are all virtually insoluble to allow isolation of the pure barium permanganate. The barium permanganate thus formed can also be reacted with other soluble sulfate salts, such as ammonium, zinc, cadmium, magnesium and nickel to form the corresponding permanganates in high yield along with insoluble barium sulfate. Drawbacks of this process are the multiple reactions required, the cost of the chemical reagents, and the waste by-products generated, which require suitable treatment and disposal.
[0007] Ion exchange has been used for the production of liquid (calcium) permanganate. A patent for the process was issued in 1949 to T. Hagyard of Boots Pure Drug Company Ltd., (UK Patent 624,885). Solid zeolite was used to exchange the calcium cation for potassium. The process, however, did not recover the potassium value. Instead of recovering a value added co-product a waste stream of potassium chloride was generated with subsequent disposal costs.
[0008] Electrochemical membrane separation processes, also referred to as electrodialysis, metathesis electrodialysis, salt splitting, and the like, typically employ anion exchange membranes that are not stable to oxidizing agents, such as permanganate. Normally, the anion membrane would be used to transport the oxidant anion into a product stream where it would be combined with the desired cation to form a soluble permanganate salt solution. Commercially available anion exchange membranes are usually based on crosslinked; amine functionalized polystyrene divinyl benzene chains which are attacked by oxidizers resulting in increased voltage drop and loss of selectivity.
[0009] US Patent Application Publication 2006/0000713, dated Jan. 5, 2006, to Carus et al, discloses electrodialysis salt splitting methods for the production of more soluble oxidizing agents, such as calcium permanganate from less soluble oxidizing agents, like potassium permanganate. In this case, a porous separator is used in conjunction with a cation exchange membrane to split potassium permanganate, forming the more soluble permanganate salt. In order to employ a porous separator, precise pressure control must be employed to avoid excessive transport of bulk solution from one compartment to another. Since porous separators are non-selective towards any particular ion transport, current efficiencies can be low.
[0010] Accordingly, there is a need for improved, more economic electrochemical methods for the production of soluble oxidizing agents through use of more stable membranes that are also capable of providing greater permselectivity, and secondarily, for the production of useful, value added co-products without the production of large quantities of unwanted waste by-products requiring costly reagents and treatment steps for disposal.
SUMMARY OF THE INVENTION
[0011] The present invention provides for improved more economic methods for electrochemical synthesis of soluble oxidizing agents over previous technologies wherein a value-added co-product is generated in the process without more costly reagents, disposal of unwanted by-products, and the like.
[0012] The electrochemical methods of the invention provide for separation of the original oxidant cation away from the oxidizer stream, and replacement of the original cation by a cation, such as magnesium, calcium, etc., forming a more soluble oxidizer salt solution. This separation is performed without unstable anion exchange membranes or non-selective porous separators, relying instead on the selectivity of certain cation exchange membranes, such as perfluorosulfonic acid type membranes. These membranes are suitable for transporting cations with lower water of hydration, such as potassium preferentially over other more highly hydrated cations, such as sodium, magnesium and calcium, which are used to replace the leaving potassium ion and to form a more soluble oxidizer salt solution. Other cations forming soluble oxidizer salts are contemplated. The leaving cation is not wasted, but is available to form a value added co-product, such as a base or another salt in another compartment of the cell. In the case where potassium permanganate is the original oxidant and calcium or magnesium permanganate are the desired new, more soluble oxidants, residual potassium in the permanganate product and magnesium or calcium in the co-product are readily removed via inexpensive chemical precipitation steps and may then be recycled to the process. The resultant process is simpler than typical electrochemical membrane separation methods, and the membranes employed are stable to permanganate and other oxidants.
[0013] It is therefore one principal object of the invention to provide for methods of preparing oxidizing agents having enhanced water solubility properties wherein oxidizing agents having more limited water solubility properties are the starting reactants, which method comprises the steps of:
[0014] (i) providing an electrochemical cell comprising at least one oxidant stable, cationic permselective ion-exchange membrane having greater selectivity for transporting cations from the oxidizing agent having limited water solubility than cations from the oxidizing agent having enhanced water solubility. The ion-exchange membrane divides the cell into at least two compartments, an anolyte-feed compartment housing an anode and a catholyte co-product compartment housing a cathode;
[0015] (ii) introducing into the anolyte-feed compartment a solution of the oxidizing agent having limited water solubility and an electrolyte comprising a source of cations having lower selectivity for transport across the membrane than the cations from the oxidizing agent having limited water solubility;
[0016] (iii) introducing into the catholyte co-product compartment at least an aqueous electrolyte for forming at least a base, and
[0017] (iv) conducting a reaction by applying a voltage across the anode and the cathode of the electrochemical cell to form at least the oxidizing agent having enhanced water solubility properties and a value added co-product.
[0018] The improved methods of the invention employing the oxidant stable, cationic permselective ion-exchange membranes provide mainly for the transmission of the leaving cations, e.g., potassium ions, but also some cations for imparting enhanced water solubility properties to the oxidizing agent, e.g., sodium, calcium and magnesium ions. However, the membrane favors the transmission of a preponderance of the leaving metal ions (e.g., potassium) from the starting oxidizing agent having limited water solubility.
[0019] Thus, the foregoing method includes embodiments wherein oxidizing agents having enhanced water solubility properties may be formed in the anolyte compartment of the electrochemical cell, and the value added co-product formed in the catholyte co-product compartment. Alternative embodiments are contemplated, such as electrochemical cells having three or more compartments. In such electrochemical cells having more than two compartments, the oxidizing agent having enhanced water solubility properties can be prepared in the central compartment by transmission of an alkaline earth metal ions across the cationic permselective membrane from the anolyte compartment, and so on.
[0020] Thus, it will be understood that in one aspect the methods of the invention provide for the production of oxidizing agents having enhanced water solubilities starting with oxidizing agents having limited water solubility properties, such as potassium permanganate, and through a metathesis, electrodialysis and/or salt splitting reactions, for example, to form oxidizing agents having enhanced water solubility properties, such as sodium permanganate, calcium permanganate, magnesium permanganate, to name but a few. A further representative example of an embodiment of the electrochemical methods of the invention include the conversion of potassium peroxydisulfate, a salt of limited solubility, to an oxidizing agent having enhanced water solubility properties, such as ammonium peroxydisulfate.
[0021] Still the invention contemplates the production of other oxidizing agents having improved solubilities from oxidizing agents (salts) having limited water solubilities from anions, such as bromates, chlorates, dichromates, hypochlorites, iodates, perborates, percarbonates, perchlorates, periodates, and so on.
[0022] In addition to the preparation of more soluble oxidizing agents, the methods of the invention include the simultaneous preparation of value added co-products, wherein a value added product may be generated in the catholyte co-product compartment. The introduction of an aqueous electrolyte, e.g. aqueous salt solution, during electrolysis co-generates a base of the cation of the oxidizing agent having limited water solubility properties, for instance. Alternatively, value added salts can be produced, such as by the introduction of an acid into the catholyte co-product compartment to form at least a value-added co-product with the cation of the oxidizing agent having limited water solubility properties.
[0023] The methods of the invention may be conducted either as batch or continuous processes, discussed in greater detail below.
[0024] It is still a further object of the invention to provide a method for preparing oxidizing agents having enhanced water solubility properties from oxidizing agents having limited water solubility properties by the steps, which comprise:
[0025] (i) providing a three compartment electrochemical cell comprising an anolyte feed compartment housing an anode, a catholyte co-product compartment housing a cathode and a pair of adjacent oxidant stable, cationic permselective ion-exchange membranes defining a central feed compartment stationed between the anolyte feed compartment and the catholyte co-product compartment;
[0026] (ii) introducing into the central compartment the oxidizing agent having limited water solubility;
[0027] (iii) introducing into the anolyte feed compartment a source of cations for transmission across the oxidant stable cationic permselective ion-exchange membrane to the central feed compartment;
[0028] (iv) introducing into the catholyte co-product compartment at least an aqueous electrolyte solution, and
[0029] (v) conducting a reaction by applying a voltage across the anode and the cathode of the electrochemical cell to form an oxidizing agent having enhanced water solubility properties in the central compartment and a value added co-product in the catholyte co-product compartment.
[0030] This alternative method may also generate bases, e.g., alkali metal hydroxides, from a reduction reaction occurring at the cathode and from the transmission of cations, mainly from the oxidizing agent having limited water solubility, such as potassium ions, and including to a lesser extent the transmission of alkaline earth metal ions, such as calcium and magnesium. However, other value added by-products are contemplated, including organic salts, for instance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The nature and mode of the invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures in which:
[0032] FIG. 1 is a diagrammatic view of a two compartment electrolysis cell of the invention demonstrating the conversion of potassium permanganate to more soluble magnesium permanganate and value added co-products: potassium acetate and magnesium acetate;
[0033] FIG. 2 is a process flow diagram of the invention in a continuous mode of operation suitable for being conducted in a two or three compartment electrochemical cell, including downstream separation steps for removing potassium from magnesium permanganate and magnesium from potassium acetate, with recycle loops for returning recovered reagents to the front end of the process;
[0034] FIG. 3 is a diagrammatic view of a three compartment electrolysis cell useful for the conversion of potassium permanganate to magnesium permanganate and potassium acetate;
[0035] FIG. 4 is a graph showing the relative transport of potassium and magnesium at various feed compositions, performed in a two compartment cell equipped with a NAFION® 324 perfluorosulfonic acid cation exchange membrane, and
[0036] FIG. 5 is a diagrammatic view of a two compartment electrolysis cell useful in the conversion of potassium peroxydisulfate to ammonium peroxydisulfate with the simultaneous production useful co-products: ammonium acetate and potassium acetate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Thus, the novel and inventive electrochemical methods of the invention are primarily for the production of oxidizing agents having enhanced water solubility properties, and secondarily for the production of useful, value added co-products without costly disposal steps, wherein more readily available oxidizing agents perform as a principal reactant in the process. The methods are performed in an electrochemical cell configuration requiring only cationic permselective ion-exchange membrane(s) stable to oxidizing agents and possessing sufficient selectivity for the leaving cation over the transport of the new oxidant salt cation. The selectivity is deemed adequate particularly if economics, including purification and credits for co-products are favorable to traditional methods for producing oxidizers. Clean-up techniques for removal of undesired cations present due to imperfect separation are simple and inexpensive.
[0038] Methods of the invention provide for making oxidizing agents, especially oxidizing agents having enhanced properties, such as improved water solubility over the first reactant oxidizing agent. Details of the invention may be demonstrated by the following embodiments:
[0039] The first embodiment ( FIG. 1 ) relates to the production of an oxidizing agent and a value added co-product in a two compartment electrochemical cell 10 , sometimes referred to as a salt splitting cell. Principal components of the two compartment cell include an anode 12 , cathode 14 and cationic permselective ion-exchange membrane 16 with selectivity predominantly for the first oxidizing agent cation transport, i.e., potassium ions. The two compartment electrochemical cell further comprises an anolyte or feed compartment 9 for housing the anode 12 and a catholyte or co-feed compartment 11 for housing cathode 14 . The cationic permselective ion-exchange membrane 16 divides the cell into dual compartments and is commercially available through ordinary channels of commerce under the Trademark NAFION® from E.I. DuPont. This, and other such cation exchange membranes (discussed in further detail below) are stable in the presence of oxidizing agents and provide desired separation and selective transport characteristics when disposed between the feed and co-product compartments.
[0040] In practicing the methods according to FIG. 1 , generally, a first oxidizing agent (KMnO 4 ) is dissolved in water and introduced into anolyte/feed compartment 9 . Water or a heel of co-product solution for improved conductivity is introduced into the catholyte/co-product compartment 11 . A voltage is impressed across the anode and cathode sufficient to produce hydroxide at the cathode and protons at the anode. The protons briefly form the acid (permanganic acid) of the oxidant in the feed stream, and then may be neutralized by an added base to form the desired oxidizing agent salt.
[0041] For example, if magnesium permanganate were the desired soluble oxidizing agent, then magnesium oxide, hydroxide, or carbonate would be added to the feed stream to immediately neutralize the permanganic acid formed at anode 12 . Hydroxide ion formed at the cathode 14 may be combined with the transported cation to form a valuable base co-product. For example, if potassium permanganate were the first oxidizing agent, then transported potassium would form potassium hydroxide. Alternatively, the base formed may be reacted with an added acid to form a value added potassium salt, e.g., KOAc. Acetic acid (HOAc) may be added to the co-product chamber to form principally potassium acetate, and secondarily, some magnesium acetate.
[0042] The method may also include any necessary concentration and cleanup steps to render the product (Mg(MnO 4 ) 2 ) and co-product (KOAc and Mg(OAc) 2 ) saleable. For example, potassium permanganate remaining unchanged in the liquid permanganate product may be conveniently removed by evaporative crystallization as it is considerably less soluble than the magnesium permanganate product, and returned to the process. Evaporative crystallization would also serve to concentrate the liquid product to the desired strength. Since the membrane will not be perfectly selective for potassium transport, the co-product will be contaminated to some degree by the new permanganate cation. For example, if magnesium permanganate and potassium acetate are being produced, some magnesium transport into the co-product stream will occur, although the perfluorosulfonate membrane favors potassium transport. Magnesium may be removed by addition of KOH to the salt co-product, precipitating the insoluble magnesium hydroxide, which may be filtered off and recycled to the process. The result is a pure stream of salt co-product, such as potassium acetate or potassium chloride. If desired, this stream may be concentrated by evaporation. (See FIG. 2 )
[0043] One object of the invention is to produce a liquid permanganate salt from potassium permanganate and to recover the potassium values as a saleable co-product. FIG. 2 is a process flow diagram illustrating a continuous operation of either a two (or three) compartment embodiment wherein the liquid product is continually drawn off from the cell, concentrated and purified by evaporative crystallization. Recovered potassium permanganate is recycled and added to the cell liquor. New potassium permanganate feed is also added to the cell liquor to replace the permanganate drawn off with the product and to maintain steady state concentrations of reactants. Similarly, the co-product potassium acetate may be continually drawn off and purified by addition of KOH to precipitate Mg(OH) 2 for recycle to the permanganate feed liquor. The co-product liquor composition is maintained by electrolysis bringing potassium into the stream with acetic acid addition.
[0044] Alternatively, the process may be operated in a batch mode where the products and reactants are not drawn off and the composition of the cell liquors is allowed to change until a desired endpoint is reached.
[0045] As best illustrated by FIG. 3 , in some instances it may be preferable to isolate the anode from the concentrated oxidizing agent feed because of anode fouling or corrosion issues. This may be performed using a three compartment electrochemical cell 20 of FIG. 3 . For example, at high temperatures, permanganic acid may be so unstable that it decomposes directly on the anode, causing fouling and voltage rise. In this case, a barrier compartment 22 is created between first and second cation exchange membranes 24 and 26 , respectively. The first oxidizing agent feed (KMnO 4 ) is now in the central/barrier compartment 22 . Cations (Mg +2 ) used to form the new oxidizing agent are supplied from the anolyte 28 , and the first oxidant cations (K +2 ) are transported into the catholyte 30 as in the two compartment embodiment ( FIG. 1 ). Base added to the anolyte (Mg +2 ) 28 neutralizes protons generated at the anode. The added cation from the base replaces that which is transported into the permanganate feed. The anolyte 28 will thus be composed of an inert salt which remains unchanged during the process. Other than the use of dual adjacent cation exchange membranes 24 - 26 , and an inert anolyte solution 28 , the three compartment embodiment of FIG. 3 is similar to the two compartment process of FIG. 1 .
[0046] The three compartment process of FIG. 3 may be conducted by the steps of providing a three compartment electrochemical cell 20 having an anode 32 in the anolyte compartment 28 and a cathode 34 in a co-product compartment 30 , the electrochemical cell having two cation exchange membranes 24 and 26 stable to oxidizing agents and providing desired separation characteristics disposed between the anolyte and feed and feed and co-product compartments.
[0047] The three compartment process may be practiced by the steps of introducing a solution of first oxidizing agent (KMnO 4 ) dissolved in water into the feed (barrier) compartment 22 ; introducing water or a heel of co-product solution (catholyte) 30 for improved conductivity into the co-product compartment; introducing a solution of an inert salt electrolyte into the anolyte 28 compartment. The salt will be comprised of the desired cation (Mg +2 ) used for forming the new oxidizing agent (Mg(MnO 4 ) 2 ) and an anion that will not react at the anode, such as sulfate or nitrate.
[0048] A voltage is impressed across the anode and cathode sufficient to produce hydroxide at the cathode 34 and protons at the anode 32 . Acid formed at the anode is neutralized by an added base (Mg +2 ) so that the protons are not transported into the oxidizing agent compartment 22 . Instead, the added metal cation is transported into the feed compartment 22 to form the desired new oxidizing agent salt. Hydroxide ion formed at the cathode may be combined with the transported cation to form a valuable base co-product (KOH). Alternatively, the base formed may be reacted with an added acid to form a value added potassium salt. For example, acetic acid may be added to the co-product chamber 30 to form potassium acetate.
[0049] Any necessary concentration and cleanup steps can be performed to render the product and co-product saleable. For example, potassium permanganate remaining unchanged in the liquid permanganate product (Mg(MnO 4 ) 2 ) may be conveniently removed by evaporative crystallization as it is considerably less soluble than the product, and returned to the process. Evaporative crystallization would also serve to concentrate the liquid product to the desired strength. Since the membrane will not be perfectly selective for potassium transport, the co-product may be contaminated to some degree by the new permanganate cation (Mg +2 ). For example, if magnesium permanganate is being produced, some magnesium transport into the co-product stream will occur, although the cation exchange membrane favors potassium transport. Magnesium may be removed by addition of KOH to the salt co-product, precipitating the insoluble magnesium hydroxide, which may be filtered off and recycled to the process. The result is a pure stream of salt co-product, such as potassium acetate or potassium chloride. If desired, this stream may be concentrated by evaporation.
[0050] The methods of the invention enable the production of oxidizing agents and valuable co-product electrochemically while avoiding the problems associated with such agents and other reactive species in cells equipped with anion-exchange membranes in salt splitting or metathesis electrodialysis. The use of porous separators requiring careful pressure control and allowing feed and product mixing are avoided.
[0051] The processes of the invention can be performed by selectively removing a cation from an oxidizing agent, replacing it with a different cation to form the “new”, chemically different oxidizing agent. The methods of the invention also provide for the co-production of one or more other value added by-products, such as salts and bases.
[0052] While details of the invention may be described with reference to a particular oxidizing agent, such as potassium permanganate, it is to be understood that this is for purposes of convenience only, and it should not be viewed as limiting as to the scope and content of the invention and appended claims. The inventive concepts disclosed herein are applicable to a wide range of substrates, namely the preparation of a broad variety of oxidizing agents with different cations and a wide variation of secondary salt by-products.
[0053] In practicing the present invention as illustrated in FIG. 1 , a feed permanganate solution is prepared comprised of potassium permanganate dissolved in water. The maximum concentration of the potassium permanganate feed is highly dependent on temperature and varies from about 6% at room temperature to about 33% at 90° C. The stability of the permanganate solution decreases at high temperature and it is not desirable to run the process at temperatures greater than about 90° C. It is desirable to operate near saturation as the product concentrations will be maximized and evaporation requirements reduced.
[0054] The feed permanganate solution is introduced into the anode chamber of a two compartment electrochemical cell. The anode reaction is the production of oxygen and proton from the oxidation of water. Potassium is transported out of the anolyte compartment, across the cation exchange membrane into the catholyte co-product compartment. The electro-generated proton forms permanganic acid, an unstable intermediate which is neutralized immediately with added base, such as magnesium oxide or calcium oxide. In this manner, a more soluble permanganate salt is formed in the anolyte stream. The concentration ratio of permanganate product to potassium permanganate is maintained at a value where the efficiency of potassium transport is high and evaporation costs are not excessive. Unreacted starting material may be readily separated from soluble product by concentrating the mixture via evaporation, and cooling to crystallize out sparingly soluble potassium permanganate. The highly concentrated soluble permanganate (calcium or magnesium) is soluble to at least 50%, and will tend to “salt out” residual potassium permanganate, when cooled. The resultant liquid permanganate product is largely potassium free and at a concentration desired for the marketplace. The crystallized potassium permanganate product may be recycled to the process.
[0055] In the cathode chamber, water is reduced to form hydrogen and hydroxide. An acid is added to the catholyte compartment and maintained in excess to neutralize transported potassium plus any transported calcium or magnesium. A convenient acid is acetic acid, which will form potassium acetate, a valuable co-product used for deicing. Other acids could include common mineral acids, such as hydrochloric and nitric acid, or other organic acids chosen such that the potassium salt formed is saleable. Only acids that do not form insoluble calcium or magnesium salts are suitable. Residual calcium or magnesium in the salt co-product can be removed by adding KOH or K 2 CO 3 to precipitate out the alkaline earth metal as the hydroxide or carbonate. After filtration, the alkali earth base may be recycled to the process.
[0056] The current density employed for cell operation will depend on the concentration of permanganate, which in turn depends on the solution temperature. Typically, the cell will be operated in a range between 250-4000 Am −2 .
[0057] The anode will be positioned in the feed chamber of the two compartment cell which will contain potassium permanganate feed solution. The anode reaction will be the oxidation of water to produce hydrogen and protons (Equation 1).
2H 2 O→O 2 +4H + +4e − (1)
[0058] The anode must be stable to the electrolysis conditions, and may include noble metals or alloys of Pt, Pd, Ir, Au, Ru, etc., or noble metals or alloys deposited on a valve metal such as Ti or Ta, etc. The cathode in the two compartment cell embodiment will be located in the co-product chamber. The cathode reaction is the production of hydrogen and hydroxide from the reduction of water according to reaction 2.
2H 2 O+2e − →H 2 +2OH − (2)
[0059] The cathode must be stable and may include carbons, noble metals and alloys, nickel, steels, etc.
[0060] According to the methods of the invention, useful electrochemical cells are compartmentalized employing virtually any oxidant stable, cationic permselective ion exchange membrane. Such membranes are well known among skilled artisans, and are available through ordinary channels of commerce. A key property of such membranes is their stability in the presence of oxidizing agents. In the case of a two compartment embodiment, a cation exchange membrane separates the feed and co-product compartments. Representative examples of useful cation exchange membranes may include perfluorinated membranes like DuPont's NAFION®; Asahi Glass' FLEMION® membranes; W.L. Gore's Gore SELECT®, or any other stable cation exchange membrane possessing the desired selectivity characteristics. Useful Nafion products include inter-alia those of the 324 or 424 series sulfonic acid based membranes, or 900 series carboxylate/sulfonate membranes used in chlor-alkali processes. The membranes will transport potassium ions economically, as compared to transporting the product cation, such as calcium or magnesium where calcium or magnesium permanganate is the desired liquid permanganate product. It is known that Nafion, for example, has a natural preference for transport of potassium over magnesium due to the smaller hydration sphere of potassium. According to A. Steck and H. L. Yeager ( Anal. Chem. 52, 1215 (1980)), cations with smaller hydration energies gain relatively more energy from electrostatic interaction with the exchange site, and bind more strongly to Nafion. For the divalent metals, transport will be a two electron process, which will further improve the membrane selectivity since twice as much charge will be required to transport the divalent than to transport potassium. Therefore, significantly more potassium will be transported than magnesium or calcium from equimolar solutions of mixed metal permanganates.
[0061] For the three compartment electrochemical cell method of the invention shown in FIG. 3 , the permanganate solution is fed to the central chamber of the cell, which is bounded by two cation exchange membranes. This configuration is useful when process conditions are such that the permanganic acid intermediate generated is unstable and decomposes to form manganese dioxide in the cell, thereby causing fouling and increased voltage. The metal cation forming the liquid permanganate salt is supplied from the anolyte chamber. The anolyte consists of a salt containing the desired cation to form the permanganate product and an anion which is unreactive at the anode. Sulfate and nitrate salts are typical examples.
[0062] The salt is present at high enough concentration to supply cations for transport across the membrane without encountering mass transfer limitations. High concentrations are also desirable to improve solution conductivity and reduce voltage loss. The requirements for the anode and the secondary membrane are not as stringent as in the two compartment embodiment. Namely, the anode must be stable while oxidizing water to form proton and oxygen, but need not be stable to permanganate. The anolyte cation exchange membrane must also be stable to the solutions, permanganate on one side and the anolyte salt on the other side. However, selectivity is not a requirement since the anolyte only contains one cation species.
[0063] Protons generated at the anode of the three compartment cell are neutralized in the anolyte via addition of base, such as calcium oxide or magnesium oxide after the electrochemical cell. Neutralization is done at this point to avoid proton transport across the anolyte membrane into the permanganate feed chamber, since permanganic acid would be generated and could decompose, fouling the membrane with manganese dioxide.
[0064] The following best mode working Examples of the invention will provide further enablement for practicing the invention.
EXAMPLE 1
[0065] Production of Magnesium Permanganate and Potassium Acetate in a Two Compartment Electrochemical Cell—Batch Operation
[0066] A series of batch electrolyses were performed to define the selectivity of the Nafion 324 membrane for potassium transport over magnesium transport. These two compartment experiments were performed using a MP flow cell (ElectroCell AB, Sweden) fitted with a DSA-oxygen anode, NAFION 324 membrane, and nickel cathode. The electrolysis cell corresponds to that of FIG. 1 . The solution temperature was 75° C., and the current density 100-200 mA/cm 2 . Water was electrolyzed at both anode and cathode to form H + and O 2 at the anode and OH − and H 2 at the cathode. Acetic acid was added to the catholyte to form potassium acetate. Electrolyses were performed at various ratios of potassium permanganate to magnesium permanganate in the feed, and the ratio of potassium acetate formed to magnesium acetate formed was determined. In each experiment, about 20% of potassium permanganate was converted. FIG. 4 illustrates the relative transport of potassium and magnesium at various feed compositions. For example, with an average feed composition of 13.8% potassium permanganate and 9.4% magnesium permanganate, a ratio of 6.7 moles of potassium per mole of magnesium were transported. The ratio of moles (K/Mg) transported vs moles (K/Mg) in the feed defines the membrane selectivity. For this set of experiments, the average selectivity is 1.9 moles potassium transported per mole of magnesium transported at equimolar concentration in the feed. This demonstrates the preference of the membrane for potassium over magnesium which allows an economic process.
EXAMPLE 2
[0067] Production of Magnesium Permanganate and Potassium Acetate in a Two Compartment Electrochemical Cell—Continuous Operation
[0068] A continuous experiment was performed for over 400 hours wherein magnesium permanganate was drawn off periodically and replaced with solid potassium permanganate to maintain an average feed composition of 5.9% potassium permanganate and 6.7% magnesium permanganate. MgO was added to the anolyte to form magnesium permanganate. The experiment was performed using a MP flow cell (ElectroCell AB, Sweden) fitted with a DSA-oxygen anode, NAFION 324 membrane, and nickel cathode. The electrolysis cell configuration corresponded to that of FIG. 1 . The solution temperature was 40° C., and the current density was 50 mA/cm 2 . Acetic acid was added to the catholyte to form potassium acetate, at a co-product concentration of 25-35%. The magnesium acetate concentration built up to a value of about 8%. The current efficiencies for magnesium permanganate and potassium acetate formation were between 75 and 80%. The ratio of moles (K/Mg) transported vs moles (K/Mg) in the feed (average selectivity) was 5.4. 73 lbs of magnesium permanganate and 44 lbs of potassium acetate (both 100% basis) were produced during the test.
[0069] A portion of the magnesium permanganate product from the cell was concentrated by heating to 45% magnesium permanganate. The solution was then cooled in a water bath. Precipitated potassium permanganate was removed from the cooled product solution by filtration. The residual potassium level in the 45% magnesium permanganate product at room temperature was 1069 ppm, or 0.27% as potassium permanganate.
EXAMPLE 3
[0070] Production of Calcium Permanganate and Potassium Acetate in a Two Compartment Electrochemical Cell—Batch Operation
[0071] Electrolysis was performed to define the selectivity of the NAFION 324 membrane for potassium transport vs. calcium transport. The experiment was performed using a MP flow cell (ElectroCell AB, Sweden) fitted with a DSA-oxygen anode, Nafion 324 membrane, and nickel cathode. The electrolysis cell configuration corresponded to that of FIG. 1 . The solution temperature was 75° C., and the current density 100 mA/cm 2 . Water was electrolyzed at both anode and cathode to form H + and O 2 at the anode and OH − and H 2 at the cathode. Acetic acid was added to the catholyte to form potassium acetate. Calcium oxide was added to the anolyte to form calcium permanganate. For an average feed composition of 15.4% potassium permanganate and 5.9% calcium permanganate, a ratio of 6.0 moles of potassium per mole of calcium was transported. The ratio of moles (K/Ca) transported vs moles (K/Ca) in the feed was 1.4 moles potassium transported per mole of calcium transported at equimolar concentration in the feed. Although the membrane selectivity is lower than in the magnesium case, the economics are still favorable to the current methods of producing liquid permanganate, because the potassium value of the KMnO 4 feedstock is recovered.
EXAMPLE 4
[0072] Production of Sodium Permanganate and Potassium Acetate in a Three Compartment Electrochemical Cell—Continuous Operation
[0073] Electrolysis was performed in a three compartment electrochemical cell in a continuous mode to demonstrate this embodiment avoids anode fouling. Mixed sodium/potassium permanganate product was periodically drawn off and replaced with solid potassium permanganate and water to maintain a roughly constant composition. The experiment was performed in a three compartment MP flow cell (ElectroCell AB, Sweden) fitted with a DSA-oxygen anode, two NAFION 324 membranes, and nickel cathode. The electrolysis cell corresponded to that of FIG. 3 . The anolyte was a two molar solution of sodium sulfate. The solution temperature was 75° C., and the current density 100 mA/cm 2 . Water was electrolyzed at both anode and cathode to form H + and O 2 at the anode and OH − and H 2 at the cathode. Acetic acid was added to the catholyte to form potassium acetate. Sodium hydroxide was added to the anolyte to form sodium sulfate. Sodium was transported into the feed compartment to form sodium permanganate. In this fashion, no net chemical change occurred in the anolyte. The cell was operated for 70 hours at a stable voltage. Similar experiments in a two compartment cell could not be operated for more than one day before the voltage increased due to MnO 2 formation on the anode.
[0074] For an average feed composition of 21% potassium permanganate and 6.9% sodium permanganate, a ratio of 2.7 moles of potassium per mole of sodium was transported. The ratio of moles (K/Na) transported vs moles (K/Na) in the feed was 1.0 mole potassium transported per mole of sodium transported at equimolar concentration in the feed. This performance is the same as was observed in a two compartment cell, but anode fouling was avoided. It is recognized that sodium is not an ideal candidate for this process, since there is no simple way of removing sodium from the co-product. However, the experiment did illustrate the utility of the three compartment process for experimental conditions that promote anode fouling.
EXAMPLE 5
[0075] Production of Ammonium Peroxydisulfate and Potassium Acetate in a Two Compartment Electrochemical Cell—Batch Operation
[0076] FIG. 5 shows the same two compartment cell configuration as FIG. 1 , but illustrates the production of a different oxidizing agent. Potassium peroxydisulfate is only slightly soluble (6% in water at room temperature), whereas ammonium peroxydisulfate is highly soluble and is the more desirable product. The two compartment experiment is performed using a MP flow cell fitted with a DSA-oxygen anode, Nafion 324 membrane, and nickel cathode. The solution temperature is 50° C., and the current density 50 mA/cm 2 . Water is electrolyzed at both anode and cathode to form H + and O 2 at the anode and OH − and H 2 at the cathode. Ammonium hydroxide is added to the peroxydisulfate to neutralize electrogenerated proton and form ammonium peroxydisulfate. Acetic acid is added to the catholyte to form potassium acetate. With an average feed composition of 10% potassium peroxydisulfate and 8.3% ammonium peroxydisulfate, a ratio of 3 moles of potassium per mole of ammonium is transported. This demonstrates the preference of the membrane for potassium over ammonium which allows an economic process.
[0077] When the ammonium peroxydisulfate product is concentrated to 40% and cooled, the residual potassium peroxydisulfate content is less than 1%. The crystallized potassium peroxydisulfate is separated from the concentrated ammonium acetate solution and recycled to the peroxydisulfate feed. Excess KOH is added to the potassium acetate co-product to raise the pH and convert ammonium acetate impurity to potassium acetate. When the solution is heated to evaporate the potassium acetate to 50%, free ammonia is driven off at the high pH. The ammonia vapor is scrubbed into the anolyte to form more ammonium peroxydisulfate. The purified potassium acetate is pH adjusted to neutral pH by addition of acetic acid and is ready for sale.
|
Methods for preparing oxidizing agents having enhanced water solubility properties, such as magnesium permanganate, calcium permanganate and ammonium peroxydisulfate are prepared from oxidizing agents having more limited water solubility properties, such as potassium permanganate and potassium peroxydisulfate by electrochemical means employing oxidant stable, cationic permselective ion-exchange membranes that are also suitable for transporting a preponderance of cations with lower water of hydration, such as potassium over other more highly hydrated cations, such as sodium, magnesium and calcium used to replace the leaving potassium ion, and form more soluble oxidizer salt solutions. The methods may be practiced in multi-compartmentalized electrolytic cells, such as metathesis electrodialysis cells. The methods of the invention are also more attractive economically over previous technologies by simultaneously generating a value-added co-product without costly reagents, while avoiding the disposal of unwanted waste by-products, and the like.
| 2
|
BACKGROUND OF THE INVENTION
The present invention concerns a heald frame for weaving looms characterized by an extremely simple structure, the asymmetrical configuration of which has proved to be surprisingly advantageous.
It is known that, in weaving looms, the problem arises of giving to the heald frames a structure adapted to guarantee, without any excessive weight, a rigid behavior of such frames in dynamic conditions. In substance, it is necessary to avoid, or anyhow reduce to a minimum, the relative strains which, in dynamic conditions, tend to arise between the heald slide bars forming each frame (generally, elongated extruded sections), so as to reduce the dynamic flexural component which causes the breaking of the yarn.
In the past, said problem has been solved by inserting an intermediate tie rod connecting the two heald slide bars of the frame, so as to keep the distance between them constant during the working of the loom, or by stiffening the structure of the frame through increase of the moment of inertia of the heald slide bars, or finally by using, to form the heald slide bars, special composite materials of high rigidity and low weight.
The first two of these solutions have proved to be very scarcely practical, particularly as they create undesired bulk, they can cause interference with the warp yarns, and they considerably increase the mass and thus the inertia of the heald frames, while the third one involves excessive costs, taking into account the specific field of application.
SUMMARY OF THE INVENTION
The present invention now proposes an original and fully unexpected solution to the above problem, by giving to the heald frames an asymmetrical configuration which guarantees an extremely advantageous behavior of such frames in respect of the strains in dynamic conditions.
In substance, the present invention concerns a heald frame for weaving looms, of the type wherein the two heald slide bars consist of standard elongated sections, characterized in that it comprises a lower heald slide bar formed of an elongated section of smaller width than that of the elongated section forming the upper heald slide bar.
Preferably, in practice, the upper heald slide bar is formed from a standard type extruded section 120 mm wide, while the lower heald slide bar is formed from a standard type extruded section 96 mm wide.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is now described in further detail, with reference to the accompanying drawing, which shows an embodiment of the heald frame for weaving looms according to the invention, as compared to the known type heald frames. In said drawing:
FIGS. 1 and 2 are front views showing a first and a second type of conventional heald frame; and
FIG. 3 is the front view of the heald frame according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawing, it can be seen how conventional heald frames had a symmetrical configuration, being formed with a pair of identical heald slide bars consisting of elongated narrow sections 1 and 2 (FIG. 1), for example of the standard type having a width of 96 mm, or else of elongated wide sections 3 and 4 (FIG. 2), for example of the standard type having a width of 120 mm.
These frames had the drawbacks which have already been described.
According to the invention, a heald frame is formed with the asymmetrical configuration shown in FIG. 3 using, to form the lower heald slide bar designed to be connected to the weaving machine, a standard type elongated narrow section 5 having a width of 96 mm and, to form instead the upper heald slide bar, a standard type elongated wide section 6 having a width of 120 mm.
With this asymmetrical configuration--totally unforeseeable since, going by intuition, it could have been thought to obtain an advantage by extending the width of the lower heald slide bar rather than that of the upper one--the already considered problems are efficiently solved. Surprisingly, in fact, the dynamic behavior of the frames is thereby considerably improved--as has been experimentally proved--without giving rise to weight and bulk increases apt to cause inconveniences.
This behavior can be explained by observing that, in the case of conventional symmetric heald frames, the strains in both heald slide bars are generally directed in different senses, as well as being of different intensity. But in the case of the asymmetrical heald frame according to the invention, both heald slide bars deflect in the same sense, even if to a slightly different extent one in respect of the other: in this way, the frame behaves dynamically, keeping substantially unvaried distances between corresponding points of the two heald slide bars (no or practically no relative flexure); the breaking of the frame stitches, which easily occurs in the case of conventional frames--unless their structure is strengthened--is thus prevented in the frame according to the invention, without having to resort to the disadvantageous devices of known technique, with evident considerable progress.
It should be noted that the proposed solution, as well as being extremely economic, in that it uses interchangeable parts which are already widely used in this field of technique, also keeps the weight and inertia low, in that it strengthens the structure of only one of the heald slide bars of the frame and, above all, it does not introduce any kind of supplementary bulk.
It has also been found that the heald frame according to the invention behaves particularly well at the high speeds, even in the case of working with unbalanced weaves, as is indispensable in certain types of weaving.
When speaking of "width" in the above text, it is of course to be understood that reference is made to the dimensions that appear as the heights of the members 2-6 in the drawing.
As in conventional, the two heald bars 5 and 6 are rigidly connected at their ends to the heald frame and are supported by brackets 7.
|
In a heald frame for weaving looms, wherein the two heald slide bars consist of standard elongated sections, the lower heald slide bar is formed of an elongated section of width smaller than that of the elongated section forming the upper heald slide bar.
| 3
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of provisional patent application No. 61/026,371 filed 5 Feb. 2008 by the present inventor.
FEDERALLY SPONSORED RESEARCH
Not applicable
SEQUENCE LISTING OR PROGRAM
Not applicable
FIELD OF THE INVENTION
This invention relates generally to equipment, techniques, and processes for ion beam-slicing of wafers and ingots of semiconductor materials and other materials. The invention is applicable to a variety of widely used processes such as ion beam induced exfoliation, ion-slicing, layer transfer, and similar processes wherein materials or workpieces are treated with or exposed to ion fluxes allowing a relatively thin layer of the material to be cleaved off and optionally bonded to another substrate. The present invention is also applicable to ion-implantation equipment used in the doping of semiconductors.
BACKGROUND OF THE INVENTION
Ion-Cut Process
One process of interest here is the ion-cut (or ion-slicing, or ion-beam exfoliation) process as applied to solar cell fabrication. Typically, crystalline silicon slices for solar cells range from less than 100 hundred microns thick up to several hundred microns thick and are frequently cut from ingots by wire-saw. This method is limited in terms of how thinly the slices can be cut. It also results in considerable waste of silicon material due to the kerf that is removed by the saw. The material lost as a percentage of the total only increases as the slices grow thinner.
Most generally, the ion-cut process, which has achieved commercial success in microelectronics substrate engineering, involves directing an ion beam from an ion implanter or particle accelerator, at a crystalline substrate such as a silicon wafer and implanting the ions beneath its surface. Generally hydrogen or helium ions are implanted. The ions come to rest in a very thin layer just below the surface, the depth of which is dependent on the mass and initial energy of the ions and which can be reliably predicted using well-known theories of charged particle interactions with matter. The widely used TRIM or SRIM software code is often used to perform these calculations. FIG. 1 shows data from SRIM relating the penetration depth (known as “projected range”) of hydrogen ions into silicon as a function of incident ion energy. For example, hydrogen ions impinging on silicon at 3 MeV will stop at a depth of approximately 92 micrometers below the surface, in the range of typical thickness for crystalline solar cell fabrication. In general, ion-cut processes can range from tens of keV for very thin bonded layers, up to arbitrarily high energies for thick, self-supporting slices.
The resulting subsurface damage layer is concentrated around the depth where the ions stop and it weakens the crystal structure at that depth. Subsequent external heating of the substrate consolidates the implanted gas and nucleates and grows micro-bubbles, further weakening the crystal lattice. Given a sufficient dose of implanted ions and the appropriate application of heat or other source of stress to initiate cleavage, the crystal can be induced to cleave along the plane of the implanted layer yielding a thin crystalline sheet. For stability, very thin layers are generally bonded to a mechanically supportive ‘handle’ prior to cleaving.
The potential use of the ion-cut process for solar cell manufacturing is described in the technical literature, for example: “Crystalline thin-film silicon solar cells from layer-transfer processes: a review”, R. Brendel, Proc. 10th Workshop on Crystalline Silicon Solar Cell Materials and Processes, Aug. 13-16, 2000, Copper Mountain, USA, B. L. Sopori, ed. Advantageously, the ion-cut slices can be cut as thin as desired and there is minimal wasted material since the material is cleaved rather than sawn. A single ingot can be repeatedly sliced to yield a large number of slices.
Cooling
One technical hurdle is the removal of heat deposited by the ion beam. On one hand, it is necessary that the implant be performed at temperatures below roughly 400 or 500 C, otherwise the implanted ions may diffuse away during implantation, or uncontrolled, premature cleaving and bubble formation could occur. On the other hand, it is desirable that the beam flux (ion current) be high in order to achieve maximum possible productivity. The substrate may easily be subjected to tens of kilowatts of power into its surface owing to high beam currents in combination with beam energies in the MeV range.
It will be readily apparent to those familiar with accelerator and ion implantation art that a further complication arises due to the necessity to produce, transport and deliver ion beams in vacuum. Cooling of objects in vacuum is widely known to be quite difficult since there is substantially no gas present to aid in the conduction of heat across mechanical joints.
One well known method of controlling the temperature of a workpiece is to cool the surface opposite the surface receiving the energy. This approach is widely used in commercial ion implanters, for example, and also numerous other types of semiconductor processing equipment. The workpiece, generally a silicon wafer less than 1 mm thick, is secured to a cooled support plate either by electrostatic chuck, centrifugal force, or mechanical clamp. A small amount of low pressure gas, typically helium, hydrogen or nitrogen, between 5 and 50 Torr, is bled into the tiny gap between the back of the workpiece and the support plate in order to enhance heat conduction across the gap. The leakage of this so-called “back-side gas” from behind the workpiece into the main vacuum chamber is low enough that it does not appreciably raise the overall pressure of the vacuum system. The size of the gap is determined by the curvature and roughness of the surfaces in contact, and their ability to conform to each other under light pressure. Typical gaps range from 10-50 microns for hard materials. For example, across a 25 micron gap, the specific thermal resistance will be 0.00016 K-m 2 /W for helium and 0.00095 K-m 2 /W for nitrogen. If the ion beam is directed into a single workpiece, the area averaged power densities that may be encountered in the solar cell manufacturing process described above can exceed 1 MW/m 2 depending on the available ion beam current. The resulting temperature drop across the gap alone can be several hundred or even 1000 degrees C. The thermal resistance of the gap increases at the back-side gas pressure drops below roughly 50 Torr.
Furthermore, for relatively thick workpieces as in the solar application described above, there is an additional temperature drop between the surface receiving the ion beam treatment and the cooled back surface due to the thermal resistance of the workpiece itself. For example, a 2 cm thick ingot of silicon at 400 C will have a specific thermal resistance of 0.0004 K-m 2 /W which can easily add several hundred degrees C. addition temperature delta. In the case of the ion-cut solar application, the workpiece is successively made thinner as slices are removed from the implanted surface. The temperature difference between the implanted surface and the cooled surface therefore changes over time. This can negatively impact the reproducibility of the process and the size of the process window.
One obvious solution to this problem is to process multiple workpieces simultaneously by spreading the ion beam over a large area, thereby reducing the average power density into each workpiece and reducing the temperature drops. Stated equivalently, the total power delivered by the beam is removed through a larger cooling surface. This is an effective method but it incurs the difficulties of processing multiple workpieces simultaneously. The ion beam optical elements, such as electromagnets or electrostatic deflectors, which are used to scan and collimate the beam must be larger and more expensive. All the vacuum chambers and workpiece handling mechanisms will also be larger, more complex, and more expensive in order to handle arrays of workpieces.
Such difficulties with workpiece temperature control and ion beam heating of the substrate are widely known in the ion-implantation of wafers for semiconductor chip making The problem is obviously most acute for implantation at relatively high beam current and high energy. A commonly used technique is to arrange a plurality of workpieces, typically 13 or 25, on the periphery of a spinning disk. This spreads the heat flux over multiple workpieces by distributing the beam flux across multiple workpieces in time, rather than space. This approach however also requires the wafers to be processed in batches which complicates and adds cost to the equipment overall. The large disk has significant inertia and takes time to achieve the required speed before the ion beam can be applied to the workpieces, reducing equipment productivity.
OBJECT OF THE INVENTION
Accordingly, it is a general object of this invention to provide a machine architecture and process sequence that performs ion-cut processing of wafers or ingots of material but is that also simple, reliable, flexible and has low cost-of-ownership. Some particular objects of this invention include the:
i. Providing an ion beam processing system wherein the workpieces are processed serially rather than in batches; ii. spreading of ion beam heat load across multiple to prevent workpiece temperature from becoming excessive; iii. avoiding the use of workpiece carriers or trays which require additional automated handling and periodic refurbishment; iv. minimizing the size and cost of ion beam scanning and delivery components such as magnets; v. providing a low volume, high speed vacuum load lock to enable high productivity while minimizing the pump cost; vi. providing a vacuum load lock that conforms generally to the shape of the workpiece, even as the workpiece grows smaller with repeated slicing; vii. providing an integrated workpiece handling system adapted for a cyclic flow of workpieces, as in the repeated slicing of workpieces; viii. providing an integrated workpiece handling system adapted for performing multiple process steps in parallel for high productivity; ix. minimizing the amount of work-in-process material in order to minimize losses due to machine failure; x. minimizing the overall size the target chamber to reduce the quantity and cost of radiation shielding; xi. providing mechanically simple loading and unloading of fresh workpieces and completed slices; xii. allowing for easy scalability of the system for different workpiece dimensions and to higher beam currents; xiii. providing a system architecture that is flexible and modular whereby process modules can be added or removed easily; xiv. providing a processing system wherein sensing elements such as for workpiece temperature and beam current are fewer since the workpieces move sequentially past the sensors rather than requiring a multiplicity of separate sensors for addressing multiple workpieces in parallel.
While the following description of the invention makes particular reference to the ion-cut slicing of silicon ingots as mentioned above, this is not intended to restrict the more general applicability of the invention.
SUMMARY OF THE INVENTION
The ion-slicing embodiment of the present invention comprises two main process carousels. Other embodiments directed at ion implantation for semiconductor manufacturing may comprise only a single carousel however the following description will focus initially on the ion-cut embodiments.
The term ‘carousel’ is intended here to refer very generally to any device for circulating a plurality of workpieces along a path or a sequence of discreet stations, as in a circulating conveyor system, wheel, or turret etc. A carousel adapted to receive only two workpieces and exchange them between two discreet positions we refer to as a ‘swapper’. In the present application, the term ‘carousel’ is generally used to refer to one of the two main workpiece processing carousels, whereas ‘swapper’ generally refers to a workpiece transfer device used simply to move workpieces around. In one embodiment, however, one swapper also functions as a minimalist process carousel.
The first carousel is adapted to support a plurality of workpieces, and is particularly adapted to expose the workpieces to an ion beam and to cool them. The first carousel begins stationary, with one of its workpieces in a preselected first transfer position. The first carousel then begins moving and exposing the workpieces sequentially through the ion beam. The first carousel then stops with a different workpiece located in the specified first transfer position. This operation of the first carousel is one of the key elements of the invention and will be described more fully in the detailed description below.
At least one second carousel, also adapted to support a plurality of workpieces, generally handles any other post-implant process steps that may be required, such as annealing, bonding, cleaving, cleaning, surface treatment, outputting slices, receiving fresh ingots, etc. In a preferred embodiment, the second carousel shifts all its workpieces to subsequent processing stations at the same frequency that the first carousel performs one complete implant cycle. In this way, these post-implant process steps are performed in parallel on a plurality of workpieces. The first (and final) station of the second carousel is define to be second transfer position.
As slices of workpieces are removed from the second carousel, the remainder of the workpiece must be returned to the first carousel for subsequent slicing. Transfer mechanisms are provided to essentially perform a swap between carousels: the implanted workpiece at the first transfer position of the first carousel is swapped with the completed workpiece at the second transfer position of the second carousel.
In a preferred embodiment, however, the first carousel in situated inside a vacuum chamber, as vacuum is generally necessary for the transport of ion beams. The second carousel may be situated inside or outside the vacuum chamber depending on the details of the post-implant processes. In one embodiment illustrated herein it is assumed the second carousel is outside the implant vacuum chamber. As a result, the swapping process not direct, but includes multiple swaps and a transfer in or out of vacuum of the respective workpiece through a vacuum load lock device. The carousel mechanisms and the swap mechanisms can be realized in a variety of ways. One particular embodiment employs a novel variable volume load lock that enables high speed transfer of workpieces in and out of vacuum.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of proton range in silicon as a function of energy from SRIM.
FIGS. 2 a and 2 b are perspective views of an embodiment of the ion-cut processing machine, and are identical except FIG. 2 b has the target vacuum chamber 30 hidden to show internal elements.
FIG. 3 is a detail view of a vacuum swapper.
FIG. 4 is a detail section view of the load lock and atmospheric swapper.
FIG. 5 is a schematic view of the load lock vacuum system
FIG. 6 is a chart showing a typical processing sequence.
FIGS. 7 a - f are schematic representations of several different embodiments of machine architecture.
DRAWING REFERENCE NUMERALS
10
Ion Beam
20
Ion Beam Delivery Tube
30a, b
Target Vacuum Chamber (a: Cover; b: Base)
35
Pump port
40
Slice stacker
42
Slice transfer arm
45
Slice stack
50
Workpiece stacker
52
Workpiece transfer arm
55
Workpiece
60a, b
Anneal heater module
70
Cleave module
80
Second Carousel
90
Atmospheric Swapper
100
First Carousel
105
First Carousel Workpiece Support
110
Vacuum Swapper
115
Vacuum Swapper Arm
120
Plunger
130
Pumping channel
140
Vacuum-side o-ring groove
142
Atmosphere-side o-ring groove
144
Gap Filler Piston O-Ring Groove
150
Gap Filler Piston
160
Gap Filler Motor
170
Gap Filler Lead Screw
200
Load Lock
205
Batch Load Lock
207
Workpiece Buffer
210
Rough Vacuum Plenum
220
High Vacuum Plenum
230
High Vacuum Pump
240
Rough Vacuum Valve
250
High Vacuum Valve
260
Rough Pump
DETAILED DESCRIPTION OF THE INVENTION
As discussed in the background section, FIG. 1 shows, for reference, a plot of the range of hydrogen ions in silicon as a function of ion energy. It is plotted from values produced by the publicly available ion simulation software SRIM.
FIGS. 2 a and 2 b show one preferred embodiment of the ion-cut processing system. FIGS. 2 a and 2 b are identical except FIG. 2 b has the vacuum chamber hidden to show the internal elements. In these figures some elements and details such as support structures are not shown or are simplified for clarity. Referring to FIG. 2 a , ion beam 10 enters the target vacuum chamber 30 via beam tube 20 which is coupled to an ion source, accelerator, and beam delivery and scanning optics (not shown), all of which are generally under vacuum. The target vacuum chamber 30 comprises a vacuum chamber cover 30 a and vacuum chamber base 30 b.
Referring now to FIG. 2 b , with the target vacuum chamber 30 hidden to expose the internal features, a plurality of workpieces 55 is supported on first carousel 100 . Some of the workpieces 55 are not numbered for clarity. At the instant shown in the figure, ion beam 10 strikes one of the workpieces 55 . In the illustrated embodiment there are 8 workpieces 55 supported on 8 first carousel workpieces supports 105 of wheel-shaped first carousel 100 . First carousel 100 is adapted to rotate as indicated by an arrow thereby passing the workpieces 55 sequentially under ion beam 10 and exposing them thereto.
Vacuum swapper 110 is adapted to swap a fully implanted workpiece 55 a on first carousel 100 with another fresh workpiece 55 b located on plunger 120 . The term ‘fresh’ refers here to a workpiece that may have been partially sliced but is ready to be implanted, while ‘new’ refers to a workpiece that is of the full thickness and has never been sliced. Swapper 110 will be described in more detail later. Note that at the instant shown, an arm of vacuum swapper 110 is engaging first carousel 100 , preventing it from advancing while simultaneously ion beam 10 is striking a workpiece. This is for illustrative purposes: in most actual situations, ion beam 10 , would be turned off, or directed off the workpiece during a swap to prevent over-dosing and over-heating the workpiece.
We define one ‘implant cycle’ to be the steps of:
i. starting with carousel 100 stationary and a workpiece support 105 adjacent to swapper 110 ii. accelerating first carousel 100 iii. exposing workpieces 55 to ion beam 10 iv. decelerating first carousel 100 to a stop with a workpiece support adjacent to swapper 110 v. swapping two of workpieces 55 using vacuum swapper 110
Let M denote the number of workpieces 55 and workpiece supports 105 on first carousel 100 . In one implant cycle, first carousel will have advanced by a total of N workpiece support positions. In general N may be greater than, less than, or equal to M, where N=M corresponds to one full revolution of first carousel 100 . In one preferred embodiment M and N are relatively prime integers (co-primes). That is they must have no common factors except 1. For example, the case of N=17 and M=8, which are relative primes, would correspond to the advancement of first carousel 100 by 2⅛ cycles or two complete cycles plus one workpiece support position. When N and M are co-prime, first carousel 100 will position a different workpiece support 105 adjacent to vacuum swapper 110 every time carousel 100 stops until, after M implant cycles all M workpiece supports 105 have been addressed by the vacuum swapper 110 . Furthermore, each workpiece 55 will reside on first carousel 100 for M implant cycles before being swapped out. In any particular implant cycle, each workpiece may receive differing exposure to the ion beam, since some workpieces may pass under the ion beam while the first carousel is still accelerating, for example. By the time the workpiece is removed after M implant cycles, it will have occupied every possible starting position on the carousel; therefore every workpiece will receive substantially identical ion doses and have substantially identical thermal histories.
Note that N may also be less than M. For example, the case of N=7, M=8 will effectively result in a backward shift by one wafer position after each implant cycle. It is preferable that N be greater than 1 in order to achieve effective spreading of heat over multiple workpieces, however it is possible, in some circumstances where heating is not a severe problem or where one wishes to intentionally heat the workpiece with the ion beam, that the system operate with N=1.
Recognizing that, for the ion-cut application, the workpieces gradually grow thinner as they are sliced and that this leads to a reduction in their thermal capacitance and thermal resistance over time, leading to changes in the surface temperature history of the workpieces, even for fixed ion dose. In one embodiment of the invention, the system changes N (while preferably maintaining the requirement of coprimality) in order to compensate for these thermal effects. Assuming a fixed beam current and implant cycle time, lower N requires a correspondingly lower workpiece speed to achieve a constant dose, but will produce higher surface temperatures. For example, after processing some multiple of M workpieces with N=17 and M=8, the recipe could be changed to N=25 or N=9 without affecting the workpiece handling sequence or the total dose, only the workpiece temperature would change as a result of the changed workpiece velocity.
Additionally, in most implant processes it is generally required that the total ion dose be well controlled. Natural variations in ion beam current can be compensated by measuring the beam current with a faraday cup and adjusting the workpiece velocity proportionately, while keeping N constant. This will result in small variations in implant cycle time since the first carousel 100 must advance a fixed ‘distance’ N at varying speeds.
This invention advantageously spreads beam power and heat flux across multiple workpieces thereby limiting excessive workpiece temperature, yet it also takes in and puts out individual workpieces, rather than an entire batch, thereby permitting simpler, less expensive upstream and downstream workpiece handling and processing systems. The present design and mode of operation are believed to be novel and advantageously combine the key benefits of both batch and serial implantation equipment.
In the preferred embodiment, the first carousel 100 rotates workpieces 55 smoothly and continuously under ion beam 10 . In an alternate embodiment, first carousel 100 may operate in an indexed, or step-and-dwell fashion wherein workpieces 55 are stationary for a short period during which one or more receives treatment by ion beam 10 . In this step-and-dwell mode of operation, the ion beam would be spread to uniformly cover the area of one or more workpieces. The steps ii, iii, and iv of the implant cycle set forth above would be altered accordingly to reflect step-and-dwell operation between workpiece swaps.
Following a swap by vacuum swapper 110 , the implanted workpiece 55 a will then be located on plunger 120 and the fresh workpiece 55 b will have been introduced to carousel 100 . Plunger 120 raises its workpiece into a load lock chamber which will be described more fully later. The load lock allows the implanted workpiece to pass through the envelope of the vacuum chamber into atmosphere. Once in atmosphere, atmospheric swapper 90 swaps the implanted workpiece from the load lock with a fresh workpiece from second carousel 80 .
Second carousel 80 is also adapted to support a plurality of workpieces 55 . Six are shown in the embodiment illustrated in FIG. 2 . Second carousel 80 indexes or steps its workpieces through a sequence of process stations. After each time atmospheric swapper 90 transfers an implanted workpiece 55 onto second carousel 80 , second carousel 80 advances its workpieces to the next process station. Accordingly, second carousel 80 will index with a period equal to the time of one implant cycle. In the embodiment illustrated in FIG. 2 , the process stations after swapper 90 are annealing heaters 60 a and 60 b , followed by cleaving module 70 which separates a slice from the top surface of the workpiece, followed by slice transfer arm 42 which moves the freed slice to the top slice stack, followed by workpiece transfer arm 52 which removes the stub-end or remnant of a fully processed workpiece and replaces it with a new workpiece from the top of workpiece stack 55 . Note that the mechanism and receptacle for handling the stub-ends or remnant of fully sliced workpieces is not illustrated here for simplicity, but is simple matter to provide a single rotary transfer arm adapted to transfer the stub-end or remnant of a fully processed workpiece to a third ‘stub-end stack’ and pick a new workpiece from the top of workpiece stacker 50 and place it on second carousel 80 .
It is particularly undesirable to expose the workpiece supports 105 of first carousel 100 to direct strike by ion beam 10 . Therefore, during the start of operation of the machine, and at the end of a production run, otherwise empty workpiece supports on one or both carousels and other positions may be populated to fill the process pipeline with workpieces. Since these workpieces will not receive full treatment by the ion beam, reusable ‘dummy’ workpieces may be used to protect the workpiece supports and to otherwise fill empty workpiece positions until the pipeline is filled. In reference to the illustrated embodiment of FIG. 2 a , these dummy workpieces could be handled and stored by simply adapting the mechanisms for handling new and stub-end workpieces, as described earlier. Specifically, a fourth ‘dummy stack’ (not shown) would supply and receive dummy workpieces which would be transferred preferably using a single transfer arm for the dummy stack, the stub-end stack and the new workpiece stack 50 . Non-productive dummy workpieces may also be used to prevent the mixing on first carousel 100 of workpieces that have been fully sliced with other that are new, as may occur for example just after a group of workpieces have been fully sliced.
Outgoing slices are held in a hopper or slice stacker 40 which preferably comprises a lift mechanism adapted for gradually moving the stack downward as it slices are added, as indicated by the arrow, thereby maintaining the top slice at a fixed height so that new slices are deposited in a repeatable position by slice transfer arm 42 . Similarly, incoming new workpieces 55 are held in a hopper or workpiece stacker 50 which preferably comprises a lift mechanism adapted for gradually moving the stack upward as workpieces are removed, as indicated by the arrow, thereby maintaining the top workpiece at a fixed height so that it may be picked from repeatable position by workpiece transfer arm 52 .
In the illustrated embodiment, second carousel 80 supports workpieces 55 and may optionally cool or heat them from below. An alternate embodiment may have the workpieces supported on specialized pedestals dedicated and fixed to each of the various process stations, and carousel 80 may only serve to pick up the workpieces 55 and transfer them to the subsequent process station.
The present invention is highly flexible and scalable, and will accommodate a wide variety of post-implant process sequences. For example, it is generally desirable that the system throughput be limited by the available ion beam current since the ion generation and delivery system is generally the most costly component of the system. If the annealing process is longer than one implant cycle, it is simple and inexpensive to provide two (or more) annealing station as illustrated by 60 a and 60 b , thereby preventing the anneal process from limiting the throughput. Alternately, if ion beam 10 itself produces sufficient annealing of the workpieces then second carousel 80 may be simplified by eliminating the annealing modules entirely. Similarly, if the cleaving process comprises a mechanical peeling of the slice, then cleave module 70 and slice transfer arm 42 may naturally be combined into a single process station. Clearly, this dual carousel system allows processes to be changed easily by changing the number or function the relatively small, low-cost modules on second carousel 80 .
An alternate embodiment directed at layer transfer, such as silicon on insulator substrates, wherein workpieces are bonded to a ‘handle’ substrate prior to cleaving can also easily be implemented. Such an embodiment may, for example, include a third carousel, turret, or swapper carrying handle substrates toward second carousel 80 wherein handle substrates are bonded to the top surface of workpieces 55 and then workpiece 55 is cleaved, the remainder of workpiece 55 continuing to cycle as before, while the bonded handle and slice are withdrawn. Yet other embodiments may include process stations for cleaning or surface preparation or in-situ process metrology.
In contrast to systems that process workpieces in parallel in batches or two dimensional arrays of workpieces on carriers, the serial processing here allows easy access to individual workpieces and reduces the mechanical complexity since handling mechanisms, process modules and sensing and process controls need not be duplicated for parallel operation.
For example, in measuring the temperature of the workpieces 55 , the present invention allows a single infrared temperature sensor to be located over the workpieces 55 on first carousel 100 whereby the carousel motion allows all workpieces to be sensed, whereas a 2 d array of workpieces requires a plurality of sensors. Similarly, the relatively localized ion beam spot allows the ion beam dump and ion beam current measurement faraday cup to be relatively compact, deep and to have good line-of-sight isolation from the workpieces. Large, area-covering ion beams are difficult to dump, to measure, and to keep uniform in two dimensions.
In the embodiment illustrated in FIG. 2 , ion beam 10 is spread to cover the full width of the workpiece 55 in at least the direction perpendicular to the motion of the workpieces (the radial direction in this embodiment) thereby forming a ribbon or curtain-shaped ion beam. This spreading may be accomplished by a variety of means known in the art including: i) rapidly raster-scanning the beam back and forth using AC electromagnets, ii) rapidly raster-scanning the beam back and forth using AC electrostatic deflector plates, iii) statically spreading the beam using DC ion-optical elements. iv) moving the workpieces in two dimensions, for example by slowly moving the entire first carousel 100 in a radial direction in addition to a faster rotary motion.
In some cases it may also be necessary to collimate the ion beam using magnetic or electrostatic elements so that the beam is substantially parallel upon striking the workpieces. It may also be advantageous, for very narrow ion beams, to spread the ion beam additionally in the direction parallel to the direction of motion of the workpieces 55 so as to minimize localized heating of the workpieces 55 .
In the illustrated embodiment of FIG. 2 , the workpieces move in circles wherein the surface velocity of material is proportional to radius. In such a case it is necessary to compensate the radial current density of the ion beam in order to produce a uniform dose of ions, independent of radius. This may be done easily using the radial ion beam scanning system and controlling the raster-scanning speed to be substantially proportional to 1/r. Alternately, the ion beam 10 may scanned in two dimensions to uniformly expose a wedge-shaped or arc-shaped region, two opposing sides of which are co-linear with the center of first carousel 100 , thereby achieving uniform dosing.
An alternate embodiment may use a carousel 100 which cycles the workpieces 55 such that they move in a straight line as they pass under the ion beam 10 . For example, the carousel 100 could be a conveyor system with an racetrack-shaped path. This approach would eliminate the need for radial compensation of the ion beam current density and would provide uniform dose and more uniform thermal treatment of the workpiece surface.
During steps i, ii, iv, and v of the implant cycle, first carousel 100 will be accelerating, decelerating, or will be stopped. One of the significant advantages of the present invention is that, during continuous operation, every fully implanted workpiece 55 will have occupied each carousel position once (relative to the ion beam position) at swap, and therefore every workpiece receives identical treatment. Therefore is it possible to apply the ion beam 10 to the workpieces even as first carousel 100 is accelerating or decelerating. This improves throughput since acceleration and deceleration time is not wasted. Clearly however, leaving one workpiece stationary, or nearly so, under the ion beam 10 during a swap may cause undesirable heating to that workpiece. To remedy this, the ion beam may be positioned so as to fall in the space between two workpieces when performing a vacuum swap. Alternately, the ion beam 10 may be switched off or redirected to a beam dump during these times.
Returning now to FIG. 2 b , the first carousel 100 is provided with workpiece supports 105 which are cooled with a coolant fluid flowing through internal manifolds. The workpiece supports 105 are adapted to receive the workpieces 55 and secure them and are preferably adapted to enhance the thermal coupling between the workpiece support 105 and the workpiece 55 , thereby cooling the workpiece 55 .
Many possible securing means are known in ion implanter art and semiconductor process equipment art and include mechanical clamps, centrifugal force, electrostatic chucks, gravity etc. Furthermore, enhancement of the thermal conductivity between a workpiece and a support is a common problem in semiconductor and vacuum equipment industries for which there is extensive prior art. Most common means are to supply low pressure ‘backside’ gas to the interface between the two parts and optionally to provide a light peripheral seal to minimize escape of backside gas. Additionally, a thermally conductive compliant material, such as a filled silicone rubber, may be disposed on the support.
FIG. 3 shows a detail view of the vacuum swapper 110 . Dual vacuum swapper arms 115 extend to the position shown, in the direction indicated by the arrows, engaging and gripping the workpieces 55 a and 55 b . Vacuum swapper 110 moves up axially, lifting both workpieces 55 a and 55 b , then rotates 180 degrees and moves down again releasing the swapped workpieces 55 a and 55 b on plunger 120 and first carousel 100 , respectively. Vacuum swapper arms 115 then retract allowing plunger 120 and first carousel 100 to move freely.
FIG. 4 shows a detail sectional view of the load lock 200 and atmospheric swapper 90 . The term load lock is widely known in the art. In general, a load lock is a device for transferring items in or out of a vacuum chamber without unsealing and admitting significant amounts of gas to the vacuum chamber. In general, a load lock comprises a void or volume or chamber adapted for receiving a workpiece and comprising two sealable openings; one vacuum-side opening coupled to the volume of vacuum chamber and one atmosphere-side opening coupled to atmosphere. It also comprises a vacuum pumping and venting system to control the pressure inside the load lock independently of the vacuum chamber. To admit an item to the vacuum chamber, the item is placed in the load lock while the vacuum-side opening is sealed. Next, the atmosphere-side opening is sealed, the load lock is pumped out to a pressure at or close to the pressure of the vacuum chamber, the vacuum-side opening is unsealed and the item is moved into the vacuum chamber. To remove an item, the aforementioned process operates in reverse.
In the illustrated embodiment of FIG. 4 , load lock 200 comprises a hole entirely through vacuum chamber cover 30 a . The vacuum-side opening is sealed or unsealed by the up or down actuation, respectively, of plunger 120 . A vacuum tight first seal is made by an o-ring disposed in vacuum-side o-ring groove 140 surrounding the vacuum-side opening. Similarly, the atmosphere-side opening is sealed or unsealed by the down or up actuation of atmospheric swapper 90 , as indicated by the double-ended arrow. A vacuum tight seal is made by an o-ring disposed in atmosphere-side o-ring groove 142 . In an alternate embodiment, the arms of atmospheric swapper 90 may actuate up and down independently so as to permit the load lock to be sealed while allowing the opposing arm to be moved up and away from the rotating second carousel 80 . Additional openings into the load lock volume are provided to allow the volume to be pumped out and vented to atmosphere. Radial pumping channel 130 ( FIG. 2 b ) is coupled to pump port 35 ( FIG. 2 a ) which is further coupled to a valve and pump enabling the load lock volume to be evacuated. The plumbing for venting the load lock is not illustrated here for clarity.
The cyclic operation of the load lock begins with plunger 120 down and supporting an implanted workpiece 55 and with swapper 90 sealing the atmosphere-side opening of the load lock. Next plunger 120 is raised, carrying workpiece 55 into load lock 200 and simultaneously sealing the vacuum-side opening. Next, the load lock is vented by admitting gas until atmospheric pressure is attained and atmospheric swapper 90 grips or engages workpiece 55 . The atmospheric swapper's gripping mechanism, not illustrated here for clarity, may be a mechanical clamping type, or alternately, may be a vacuum suction or Bernoulli-type gripper that engages the top surface of the workpiece 55 . Next, atmospheric swapper 90 , or at least its appropriate arm, is raised, and then rotated 180 degrees carrying implanted workpiece 55 out of the load lock and replacing it with a fresh workpiece. Next, atmospheric swapper 90 is lowered, sealing the air side. Next, load lock 200 is pumped down to an acceptably low pressure and swapper 90 releases the fresh workpiece 55 onto the plunger. Finally, plunger 120 moves down, carrying the fresh workpiece 55 to vacuum swapper 110 which then performs its own swap, already discussed, and the cycle repeats.
It is important that the load lock operate at very high speed since the workpieces will flow through the load lock individually and therefore it must complete a full pump-vent cycle for every workpiece processed. The load lock described above is well-suited to achieve this since the internal volume of the load lock may be kept to an absolute minimum. The volume of gas surrounding workpiece 55 inside the load lock is minimized by providing load lock side walls, in this case the opening in chamber cover 30 , which conform closely to the shape of the workpiece. The bottom and top walls of load lock 200 , in this case formed by plunger 120 and atmospheric swapper 90 , respectively, are also spaced closely to the surface of workpiece 55 thereby excluding all but a small volume of gas surrounding the workpiece 55 .
A further improvement in the load lock design is applicable to the case of ion-slicing of workpieces such as silicon ingots. In such case, the workpiece 55 gradually grows smaller as it is progressively sliced. The load lock 200 is adapted to have an internal volume which progressively grows smaller as well. This may be accomplished by means of a bellows or preferably a sealed moveable wall as illustrated in FIG. 4 . Gap filler piston 150 is adapted to move downward as workpiece 55 grows thinner. Gap filler piston 150 may be sealed to atmospheric swapper body by means of an o-ring disposed in gap-filler piston o-ring groove 144 and may be driven by lead screw 170 , turned by motor 160 , for example.
FIG. 5 shows a schematic view of the load lock vacuum pumping system further adapted for very high throughput. Load lock volume 200 is coupled to rough vacuum plenum 210 through high conductance conduits and high conductance rough vacuum valve 240 . Rough vacuum plenum 210 is pumped continuously by roughing pump 260 . The volume of rough vacuum plenum 210 is selected to be much larger than the volume of gas in load lock 200 . When valve 240 is opened, gas in load lock volume 200 will be rapidly drawn into plenum 210 until the pressures are roughly equal. For the preferred embodiment case where the volume of plenum, V P is much larger than the volume of the load lock, V LL , the resulting pressure will be approximately
p ~ p P + V LL V P p LL
where p P is the initial pressure in the plenum and p LL is the initial pressure in the load lock and is generally one bar or p LL =101323 Pa. Assuming, for example, that V P =1×10 6 cc, V LL =50 cc, p P =6 Pa, then the resulting pressure will be approximately 11 Pa, which can be reached very rapidly.
An optional high vacuum plenum 220 , also coupled to load lock volume 200 through high conductance high vacuum valve 250 , may be used to further reduce the load lock pressure. High vacuum plenum 220 is continuously pumped by a high vacuum pump such as a turbomolecular pump 230 connected to roughing pump 260 or a cryopump. After the pressure in the load lock has fallen to some relatively low pressure as a result of the opening of valve 240 , valve 240 is closed and valve 250 is opened, coupling load lock volume 200 to high vacuum plenum 220 , thereby rapidly reducing the pressure in load lock even further. Using a similar volume ratio as the above example, the pressure can be reduced to the high vacuum range of the order of 0.001 Pa. Opening the load lock at this point will introduce very little gas into the relatively large target vacuum chamber 30 , thereby causing a negligible increase in the pressure in chamber 30 .
Plenums 210 and 220 act to smooth out the spikes in pressure seen at the pump inlets, maintaining the pressure at the respective pump inlets very close to the time-average pressure, rather than exposing the pumps to periodic pressure bursts every time the load lock is pumped out. This above technique combining an ultra-low volume load lock with pumping plenums is highly advantageous: first because it allows the load lock to be pumped very rapidly; and second because it enables the pumps to operate continuously in their optimum operating regime, enabling the system designer to size the pumps to handle the average gas flow rather than selecting larger, more expensive pumps to handle peak pressures.
FIG. 6 shows the sequence of operations of a preferred ion-cut embodiment of the invention. Shown in the first column are the various modules that comprise the ion-cut processing system. Displayed horizontally are the various states or processes of each module. Vertical arrows indicate cause and effect: the process at the head of the arrow may proceed only after the process at the tail of the arrow is complete. In FIG. 6 two complete cycles of the system are shown between heavy vertical lines. Each cycle takes a time t cycle .
The cycle begins just after a fresh workpiece has been placed on first carousel 100 . The carousel accelerates, implants, and stops, allowing the vacuum swapper 110 to swap workpieces after which the cycle may repeat. The start of a cycle also triggers plunger 120 to move up, then the load lock 200 can vent, then the atmospheric swapper 90 can swap, then the load lock 200 can pump out, then plunger 120 can move down again, allowing the vacuum swapper 110 to swap. It can be seen that vacuum swapper 110 may only swap after both first carousel 100 has stopped and plunger 120 has moved down. The completion of a swap by atmospheric swapper 90 triggers the indexing of second carousel 80 . After the indexing, a comparatively long period of time is available for each of the non-implant process modules such as Anneal 1 ( 60 a ), anneal 2 ( 60 b ), cleave ( 70 ), pick ( 42 ), and others, to operate in parallel.
In some cases it may be possible to perform the ion-cut process using process modules that operate generally in vacuum. For example, annealing may be done in vacuum and the cleave operation may done using a pulse of energy or heat. In such case, an alternate embodiment of the ion-cut apparatus may be used, wherein second carousel 80 is located with first carousel 100 inside vacuum chamber 30 . In that embodiment, workpieces are transferred between carousels preferably using a single, simple vacuum swapper 110 and outgoing slices may themselves be transferred to atmosphere through a high speed load lock.
An embodiment of the present invention directed at semiconductor ion implantation (doping) would not generally require a second carousel. In that case, the first carousel 100 would operate generally as described above but with silicon wafers entering and leaving the system at the point of load lock 200 or atmospheric swapper 90 , wherein the wafers would be transferred to and from cassettes via conventional robotics and front-end modules widely known and highly standardized in the industry.
In the case of ion implantation for microchip fabrication (doping), the batch size has generally been selected with reference to the standardized number of wafers in wafer transport cassettes. Specifically, microchip manufacturing almost universally uses cassettes of 25 wafers, therefore the batch size in commercial implanters has generally been either 13 or 17 wafers corresponding to roughly half a cassette or ⅔ cassette respectively. Since the first carousel 100 of the present invention accepts and emits workpieces serially, there is no need to select M with reference to the standard cassette size. Therefore the number M of workpieces on first carousel 100 may be chosen to be a relatively small number, advantageously allowing the use of a small carousel (or wheel) with low inertia. In addition to minimizing the amount of work-in-process or material in the machine, a small batch size allows the carousel to be accelerated and decelerated rapidly, thereby improving throughput. The serial flow of implanted workpieces is highly advantageous, particularly in chip-making factories that produce a wide variety of different products for different customers and where small and partial production lots do not conform well to standard cassette sizes.
Yet another embodiment of the ion-cut processing apparatus may retain the dual-carousel architecture yet process the workpieces 55 in batches of M workpieces. This embodiment sacrifices some aforementioned advantages of serial processing, however in certain cases, such as when the use of dummy workpieces is undesirable, it may be necessary. For a batch-mode of operation, the first carousel 100 would be fully populated with workpieces 55 prior to exposure to ion beam 10 . Then all the loaded workpieces would be implanted with the full dose for a time approximately M times as long as the implant cycle of the serial case. Then all workpieces on first carousel 100 would be unloaded to a batch load lock capable of receiving a full set of M workpieces. Meanwhile second carousel 80 would operate as in the serial embodiment, receiving workpieces 55 one at a time from a batch load lock onto second carousel 80 and advancing the workpieces 55 through each process. In most cases it will be preferable, to prevent throughput bottlenecks, to use two batch load locks: one feeding first carousel 100 and the other feeding second carousel 80 . The two batch load locks may alternate roles on each full cycle of M workpieces.
FIGS. 7 a - 7 f illustrate schematically some embodiments of the machine architecture. These figures are generally self-explanatory as the details have been largely discussed above, and like reference numbers substantially refer to like parts already discussed. FIGS. 7 a , 7 b , and 7 c represent embodiments of the serial type, wherein N and M are preferably co-prime. FIG. 7 a is an embodiment directed at ion implantation for semiconductor manufacturing, therefore having no second process carousel. FIG. 7 b is an embodiment of the serial ion-cut architecture wherein second carousel 80 further processes the workpieces (not shown) and returns then to first carousel 100 . FIG. 7 c is another embodiment serial ion-cut architecture wherein second carousel 80 is located in vacuum. Load lock 200 ′ is provided for extracting slices. Load lock 200 ″ is provided for removal and insertion of stub-end and fresh workpieces, respectively.
FIGS. 7 d , 7 e , and 7 f represent embodiments of the batch-type ion-cut architecture, wherein a dual carousel architecture is employed, but workpieces are disposed on, and removed from the first carousel 100 in a batch: That is, all M workpieces on first carousel 100 are implanted fully, and then all are exchanged with fresh workpieces. Note that even with batch operation of the implant process, the machine retains the advantages of serial processing in the subsequent process steps on second carousel 80 , such as annealing and cleaving, as well as the flow of slices out of the machine itself toward downstream processes.
In FIG. 7 d dual batch load locks 205 , each capable of holding M workpieces are used to pass workpieces in and out of vacuum. The batch load locks 205 may be loaded and unloaded on the vacuum-side by vacuum swappers 110 ′ and on the atmospheric-side by atmospheric swappers 90 ′. Each batch load lock 205 may comprise a elevator inside a load lock chamber adapted for supporting plural workpieces and for moving the workpieces up and down whereby each workpiece may selectively be placed adjacent to doors on each side of the load lock chamber and positioned at a plane accessible by swappers 110 ′ and 90 ′. Embodiments having only a single batch load lock 205 are also possible, as are embodiments where dual swappers 110 ′ (and 90 ′) are replaced by a single robotic device adapted for addressing two load locks and a carousel. In the dual load lock configuration, one load lock may be dedicated to removing implanted workpieces from first carousel 100 , and the other dedicated to delivering fresh workpieces to first carousel 100 . Alternately, the load locks 205 may be operated symmetrically, both transferring workpieces in via swapping, as illustrated.
A similar but highly simplified embodiment is shown in FIG. 7 e wherein carousel 80 is reduced to a simple 2-position swapper: one position addressing single load lock 205 directly, and the other addressing a single cleaving module 70 . Slices, stub-ends, dummy workpieces and new workpieces may all be transferred in and out of the machine at cleave module 70 , as represented by the arrows. Note that a similar highly simplified implementation of second carousel 80 could be employed in the embodiments of FIG. 7 b and FIG. 7 c.
FIG. 7 f shows an embodiment that is a hybrid of the batch system of FIG. 7 d with the second-carousel-in-vacuum system of FIG. 7 c . In this case batch load locks between the carousels are not necessary and are replaced by simpler in-vacuum workpiece storage buffers 207 .
In the preceding detailed description and figures, the invention is described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
|
An ion-cut machine and method for slicing silicon ingots into thin wafers for solar cell manufacturing is set forth, amongst other embodiments and applications. One embodiment comprises two carousels: first carousel ( 100 ) adapted for circulating workpieces ( 55 ) under ion beam ( 10 ) inside target vacuum chamber ( 30 ) while second carousel ( 80 ) is adapted for carrying implanted workpieces through a sequence of process stations that may include annealing ( 60 ), cleaving ( 70 ), slice output ( 42 ), ingot replacement ( 52 ), handle bonding, cleaning, etching and others. Workpieces are essentially swapped between carousels. In one embodiment, the swapping system comprises a high throughput load lock ( 200 ) disposed in the wall of the vacuum chamber ( 30 ), a vacuum swapper ( 110 ) swapping workpieces between first carousel ( 100 ) and load lock ( 200 ), and an atmospheric swapper ( 90 ) swapping workpieces between load lock ( 200 ) and second carousel ( 80 ).
| 7
|
Cross-Reference to Related Applications
The present invention is a continuation-in-part of application Ser. No. 07/929,572, filed Aug. 14, 1992, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to an apparatus for adjusting the pressure of a doctor blade against a surface while maintaining a predetermined angle of the doctor blade relative to the surface engaged by the doctor blade over a predetermined period of time.
2. Description of Background Art
Hithertofore, adjustment mechanisms have been provided for adjusting the angular relationship of a doctor blade or a creping blade relative to a surface to which the blade is disposed. Typically, a creping blade is disposed adjacent to a Yankee dryer for removing a tissue web or a paper web from the Yankee dryer. The angular relationship of the creping blade relative to the Yankee dryer may be controlled by a plurality of various levers or fluid operated bags may be utilized to adjust the angular relationship of the creping blade relative to a Yankee drum.
Once adjustments are made, the blade normally remains at the predetermined preset angle, except for the change caused by wear, until the blade is replaced.
SUMMARY OF THE INVENTION
The present invention provides a pressure adjustment member for adjusting the pressure and a biasing member operatively connected to a doctor blade for adjusting the angle of the doctor blade relative to a surface engaged by the doctor blade. A control means is provided for controlling the adjustment member and the biasing member for controlling the pressure supplied to a bearing for maintaining the predetermined angle of the doctor blade over a predetermined period of time.
The creping system of the present invention comprises a Yankee dryer rotatable about its axis, a blade engageable to the surface of said Yankee, the blade is mounted on a blade holder having a pair of colinear stub shafts, one stub shaft being attached to each end of the blade holder, the axis of the stub shafts being parallel to the axis of rotation of the Yankee. Each stub shaft engages a combination linear-rotary bearing allowing the blade to be translated in a direction parallel to the generators of the surface of the Yankee as well as to be rotated about the axis of the stub shafts. Each combination linear-rotary bearing is carried on a block engaging a fixed-attitude-linear bearing translatable along a guide rail having a substantial component perpendicular to the surface of the Yankee, and means for oscillating the blade along a path parallel to the generators of the surface of the Yankee, means for angularly adjusting the attitude of the blade holder relative to the surface of the Yankee and means for translating the blocks along with guide rails.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a schematic view illustrating an apparatus for adjusting the pressure of a doctor blade against a Yankee dryer with the control system illustrated in block diagram;
FIG. 2 is an enlarged elevational view of one of the bearings utilized to support one end of the doctor blade according to the present invention;
FIG. 2A is an enlarged elevational view of one of the bearings utilized to support one end of the doctor blade and further illustrating a control unit for the adjusting apparatus;
FIG. 3 is an end view of the bearing illustrated in FIG. 2 showing the bearing guide members mounted for guiding the movement of the bearing block;
FIG. 4 is a top plan view with a portion of the support broken away to illustrate the configuration of the bearing guide members and the bearing blocks positioned adjacent to the biasing air bag of the present invention;
FIG. 5 is an enlarged schematic view illustrating a new doctor blade disposed adjacent to a Yankee dryer wherein a flank portion has not yet developed in the bevel section of the doctor blade;
FIG. 6 is an enlarged schematic view illustrating a doctor blade having a bevel portion wherein minor wear of the doctor blade has produced a flank portion adjacent to the bevel;
FIG. 7 is an enlarged schematic view wherein the effect of increasing creping pressure without adjusting the creping angle the incipient failure sheet is in a position to split and press under the doctor blade;
FIG. 8 is an enlarged schematic view of the prior art wherein the doctor blade permits the sheet to separate with a portion of the sheet passing underneath the doctor blade; and
FIG. 9 is an enlarged schematic view wherein the attitude of a worn blade is adjusted to maintain the flank portion parallel to the Yankee tangent when pressure increases.
DETAILED DESCRIPTION OF THE INVENTION
As illustrated in FIGS. 1-4, an apparatus for adjusting the pressure of a doctor blade 10 relative to a Yankee dryer 12 is set forth. The Yankee dryer 12 is illustrated in broken lines to represent the fact that the Yankee dryer is an extremely large dryer utilized in tissue making and papermaking to supply heat to the web of tissue or paper during a final forming stage of the tissue or paper. An axle 14 is provided for mounting the Yankee dryer 12 for rotation. The doctor blade 10 is disposed adjacent to the Yankee dryer 12 to engage the outer surface 12A for creping the tissue or paper from the Yankee dryer 12 as the Yankee dryer 12 rotates.
The doctor blade 10 is secured in a holder 16 which engages the blade to the surface of the Yankee dryer 12. In addition, a blade holder assembly 18 is provided for mounting the blade holder 16. The blade holder assembly 18 includes an axle 20 which is provided to permit the blade holder assembly 18 to be rotated to a limited extent for engaging the doctor blade 10 on the Yankee dryer 12. Axle 20 includes stub shafts 20A at each end. Blade load cylinders 21 are mounted pivotally upon the machine frame (not illustrated) and are provided adjacent to each end of the blade holder assembly 18. The blade load cylinders 21 are operatively connected to the axle 20 to allow the blade holder assembly 18 to be rotated about the axis of the axle 20. Blade load cylinders 21 are free both to rotate about an axis which is substantially parallel to the axis of Yankee 12 as well as to oscillate laterally with blade holder assembly 18.
Each blade load cylinder 21 includes a rod 21A operatively mounted within the blade load cylinder 21 for reciprocal movement. A connector member 21B is affixed to one end of the rod 21A. Each connector member 21B is secured to a load arm 20C operatively mounted on a stub shaft 20A of the axle 20. Each blade load cylinder 21 is supplied with a source of pressurized air or other hydraulic fluid through air conduits 21C, 21D. Supplying pressurized air through the conduit 21C while exhausting pressurized air from the conduit 21D will impart movement to a piston disposed within the blade load cylinder 21 for imparting movement to the load arm 20C. Similarly, by supplying pressurized air to the conduit 21D while exhausting pressurized air from the conduit 21C will retract the piston disposed within the blade load cylinder 21, thus imparting an opposite movement to the load arm 20C. Load arms 20C may be splined to stub shafts 20A to enable axle 20 to be rotated about its axis while permitting lateral oscillation of the axle 20.
Bearing assemblies 30 are provided adjacent to each stub shaft 20A of the axle 20 of the blade holder assembly 18. Each bearing assembly 30 includes a housing box frame 42 which is secured to a support member flange 43. The support member flange 43 is mounted to permit the box frame housing 42 to be securely mounted to prevent movement of the box frame housing 42 relative to the Yankee dryer 12. The box frame housing 42 may be constructed from two channel irons 142, 146, one disposed on the top and one disposed on the bottom. Mounting blocks 144, 148 may be secured to the channel irons 142, 146 for securing the channel irons 142, 146 relative to each other and for mounting guide members 44, 46 relative thereto. The guide members 44, 46 extend in a direction having a substantial radial component relative to the surface 12A of the Yankee dryer 12 so that the blade 10 may be urged into engagement therewith while maintaining the blade 10 parallel to the generators of the surface 12A of the Yankee dryer 12 by moving the bearing assemblies 30 along the guide members 44, 46.
Each bearing assembly 30 comprises a bearing block 50 having a combination linear-rotary bearing 100A mounted thereon for permitting axial movement and rotational movement of the shaft 20. In addition, linear bearing members 51, 52 mounted on bearing block 50 encompass guide members 46, 44 which are operatively disposed within linear bearings 51, 52 to permit movement of bearing assembly 30 and blade holder 18 inwardly and outwardly relative to the Yankee dryer 12. Each stub shaft 20A of the axle 20 of the blade holder assembly 18 is operatively disposed through the combination linear-rotary bearing 100A in the bearing block 50 for permitting axial movement and rotational movement of the axle 20. Axial movement of the stub shafts 20A and the axle 20 permits the blade 10 to be oscillated laterally while remaining in engagement with the surface 12A of the Yankee dryer 12. Each load arm 20C is operatively connected to a stub shaft 20A of the axle 20 with enough clearance to permit axial movement of the axle 20. Each connector member 21B is affixed to the load arm 20C. As explained hereinabove, each connector member 21B is affixed to the rod 21A which is operatively connected to the blade load cylinder 21.
Stops 62 are affixed to the guide members 46, 44 to prevent portions of the blade holder assembly 18 other than the blade 10 from being moved into engagement with the Yankee dryer 12. In addition, a biasing member or air bag 70 is provided for applying a force to the bearing block 50 to impart movement to the bearing block 50 to travel along the substantially linear direction defined by the guide members 44, 46.
As illustrated in FIG. 1, a control system is provided for controlling the actuation of the various elements of the present invention. The control system includes a central processing unit (CPU) 80 with a timer mechanism disposed therein. The timer mechanism permits the present invention to be periodically adjusted to control the predetermined angle of the doctor blade relative to the Yankee dryer over a predetermined period of time. In addition, as is conventional, means are provided for imparting axial movement to the axle 20. The axial movement imparted to the axle 20 oscillates the blade holder assembly 18 to cause the doctor blade 10 to oscillate laterally relative to the Yankee dryer 12, thus alleviating wear streaking often caused by uneven blade wear. A blade angle display 81 is provided for displaying the creping angle of the doctor blade relative to the Yankee dryer 12.
A pressurized air supply 82 is in communication with a supply/discharge valve 84, 86. The supply/discharge valve 84 is in communication with each biasing member or air bag 70 operatively connected to the bearing block 50 which contains the stub shaft 20A of the axle 20. The CPU 80 and the timer control the movement of the supply/discharge valve 84 for supplying pressurized air or exhausting pressurized air from the biasing members or air bags 70. In this way, when pressurized, the biasing members or air bags 70 can exert a force on the bearing blocks 50 to permit the linear bearings 52 to move along guide members 44, 46 thereby imparting movement to the blade holder assembly along the substantially linear path defined by the guide members 44, 46. This linear movement causes a counterclockwise rotation (FIG. 2) of the blade 10 tip such that the blade angle (shown as 18° in FIG. 5) becomes smaller. Conversely, exhaust of pressurized air from biasing members or air bags 70 permit bearing assemblies 30 to move in an opposite direction along the path defined by the guide members 44, 46. This linear motion causes a clockwise rotation (FIG. 2) of the blade 10 tip such that the blade angle (shown as 18° in FIG. 5) becomes larger.
The supply/discharge valve 86 is operatively connected to the conduits 21C, 21D which are in communication with the blade load cylinder 21. The CPU 80 controls the operation of supply/discharge valve 86. In this way, movement is imparted to the load arms 20C to adjust the pressure of the doctor blade 10 relative to the Yankee dryer 12.
In addition, the motor 230 imparts rotation to the shaft 232 for rotating the cam 234. The rotation of the cam 234 imparts lateral movement to the shaft 20 for oscillating the doctor blade 10 relative to the Yankee dryer 12.
FIG. 2A illustrates a control unit 200 for the apparatus for adjusting the pressure on the doctor blade 10 mounted on the blade holder 16. Like numerals, as set forth in FIG. 2, are utilized to identify a number of the elements set forth in FIG. 2A and will not be further described hereinafter.
For each blade load, a combination of angular orientation and position can be found for maintaining the blade creping angle at its desired value. Thus, a table may be generated empirically, for each type of blade, setting forth those positions of bearing block 50 and angular orientations of blade holder assembly 18 producing the desired blade angle. For convenience, we refer to these relationships as the "set-up curve." Thus, to maintain the blade angle at the desired value as the blade wears, the orientation and position of blade holder 18 is adjusted to increase the blade load while compensating for the increased deflection of blade 10 due to that increased blade load so as to maintain the desired blade angle. The position of bearing blocks 50 is varied by pressure supplied to air bags 70 to move bearing blocks 50 and blade holder 18 toward the surface of the Yankee dryer 12, while pressure supplied to cylinders 21 will rotate blade 10 into engagement with the surface 12A of the Yankee dryer 12. However, if one of the guide members 44 binds within its associated linear bearing 52, or some other malfunction occurs, the given air pressure in one of the biasing members or air bags 70 may position the holder in an incorrect position on one side as compared to the other side of the blade holder 16. This incorrect adjustment of the blade holder 16 is, of course, highly undesirable.
Control units 200 are provided on each side of the blade holder 16. Each control unit 200 includes a linear variable differential transmitter 210 operatively mounted relative to an end wall member 202. Each linear variable differential transmitter 210 includes a sensing member 212 which projects from the linear variable differential transmitter 210 and engages an abutting surface 252 affixed to the bottom bearing members 52. The position of the abutting surface 252 relative to the end wall member 202 is sensed and transmitted to the central processing unit 80 through cables 214 and 216. A display readout unit 218 is provided in the operative connection with the cable 214 for permitting an individual to visually determine the readings generated by the linear differential transmitter 210. A cable 220 is connected to the display readout unit 218 and to the backside of the linear variable differential transmitter 210.
To obtain the correct position of the bearing blocks 50 as specified by the set-up curve, the pressure exerted through biasing members or air bags 70 on the bearing blocks 50 is adjusted to move the bearing blocks 50 into the correct position as indicated by the linear variable differential transmitter reading. The linear variable differential transmitter reading is used as controls at the beginning of loading, to supply an initial reading of the position of each bearing block 50 to the CPU 80. This signal serves as the set point for the initial position of the linear variable differential transmitter 210 corresponding to the load cylinder pressure form the pregenerated curve. The front linear variable differential transmitter loop signals the biasing member or air bag 70 to adjust the doctor blade holder 16 to the set point. The back side linear variable differential transmitter loop uses the cascade process variable from the front side linear variable differential transmitter loop to signal biasing members or air bags 70 to adjust the doctor blade holder 16 to the set point to maintain the blade holder assembly 18 in alignment. CPU 80 drives the set point of the front and rear linear variable differential transmitter loops to change the angle of the doctor blade holder 16. The load cylinder and the biasing members or air bags 70 would then correct the load and the position of the doctor blade holder 16 to match the new set point of the linear variable differential transmitter.
The control unit 200 not only maintains the doctor blade holder 16 in proper alignment, but also maintains the alignment in the case of air of hydraulic failure. The linear variable differential transmitters would monitor each other such that if a large discrepancy occurs between the two biasing members, the biasing would unload against the mechanical stops 62 to prevent a malfunction of the adjusting apparatus.
Three separate degrees of freedom of motion of the blade holder 16 are permitted according to the present invention. The blade holder 16 may be oscillated along a line parallel to the generators of the surface of the Yankee dryer 12 to prevent uneven blade wear. In addition, the blade holder 16 can be rotated against the surface Yankee dryer 12A about an axis which is parallel to the axis of the Yankee dryer 12. Further, the blade holder 16 can be moved inwardly and outwardly relative to the axis of the Yankee dryer 12.
The combination of the second two movements provides a new effect wherein the creping angle can be decoupled from the creping blade bearing pressure.
The present invention maintains constant creping angle, definable as the angle between the bevel on the blade, see FIG. 5, and the tangent to the Yankee cylinder, to minimize changes in sheet properties as the blade wears while prolonging blade life. The total load or lineal pressure, in pounds per lineal inch (pli), on the blade may be varied while maintaining constant creping angle. Thus, when the flank or land on the blade is very narrow at the beginning of a run, only a very light pli load is applied to the blade. Empirically, a bearing pressure of about 1,000 psi, calculated based on dividing total load (pli) by the actual width of the flank to yield psi, is required to prevent the sheet from passing under the blade rather than being creped off the cylinder as desired, for example. In prior art operations, the initial total load or lineal pressure on the blade has been much higher leading to premature blade wear. If the total load on the blade is set to yield a bearing pressure of 1,000 psi at the beginning of the run, as the flank wears, the bearing pressure will quickly fall below 1,000 psi leading to blade "float." Thus, the present invention maintains the bearing pressure only slightly above 1,000 psi by increasing the total load or lineal pressure to compensate for flank wear throughout the life of the blade.
FIGS. 5-9 illustrate graphically the effects of blade wear if blade attitude is not controlled. The present invention maintains a constant creping angle, called "impact angle" in U.S. Pat. No. 4,919,756, as the doctor blade is progressively used.
The creping process of the present invention begins by applying a load on the creping blade of about 3-5 pounds per lineal inch as shown in FIG. 5. Because the leading edge of the creping blade can be visualized as having essentially an infinite radius of curvature, the bearing pressure is quite high in this case, and the blade remains in intimate contact with the Yankee dryer 12. Thus, the bearing pressure is well over a thousand pounds per square inch because of the small contact area between the blade and the Yankee dryer 12. As the blade wears, a flank or land tends to form downstream of the leading edge of the blade. This flank increases greatly the contact area between the blade and the Yankee dryer 12 as shown in FIG. 6. Therefore, the bearing pressure is decreased.
In the prior art, the practice has been to begin operation with a much higher lineal pressure so that even after the blade wears, the bearing pressure between the blade and the Yankee dryer will still remain quite high. However, when the bearing pressure reaches too low a level, in the neighborhood of around 1,000 pounds per square inch the blade tends to "float" as the pressure is no longer sufficient to scrape the sheet, i.e., the dried web, from the Yankee dryer. If the lineal pressure is increased without maintaining a constant creping angle, the condition as shown in FIG. 7 begins to develop where the flank is actually presented to the sheet. This condition rapidly deteriorates to that shown in FIG. 8 wherein the blade no longer scrapes the sheet from the Yankee dryer but splits it, or the sheet may pass entirely under the blade (not shown).
As illustrated in FIG. 9, the attitude of the blade is adjusted to maintain a constant creping angle and maintain the flank parallel to the Yankee tangent. The sheet is then unable to pass under the blade and creping can continue. The lineal pressure on the blade is increased to compensate for the increased flank area while the attitude of the blade holder is adjusted to maintain a constant creping angle.
To utilize the apparatus according to the present invention, initially, an analysis is conducted on the machine of the unit to determine the minimum load requirement to start the creping process. This includes the pressure required to raise the holder plus the pressure to control the blade against the Yankee dryer 12 plus sufficient pressure to scrape the web off the Yankee dryer 12. A second number is needed, namely, the maximum load wherein the hardware is capable of functioning to exert a pressure on the doctor blade relative to the Yankee dryer 12. A third piece of data is required. A control curve is needed for the type of blade and the desired blade "stick-out" from the holder. Different levels of biasing pressure will be required depending on the yield of the blade under increasing pressure. After the proper calculations are entered into the central processing unit 80, the blade is loaded and three things will happen:
1. The minimum load will be applied to the doctor blade to the Yankee dryer 12. For purposes of discussion, air pressure will be provided to give a 25° blade angle with respect to the Yankee dryer 12.
2. For a period of time, the condition set forth in Paragraph 1 will continue. After a sufficient amount of material is worn off the corner of the doctor blade, wherein failure is within 15 to 30 minutes away, the timer within the central processing unit 80 will begin to add air pressure to the blade load cylinders 21 to adjust the pressure of the doctor blade 10 relative to the Yankee dryer 12. This increase in load, if not compensated for, would bend the blade resulting in a new creping angle, as shown in FIG. 7. To avoid this angle change, at the same time, the biasing members or air bags 70 will be reduced in pressure so that the blade angle is maintained. This process will continue until the maximum load of the system is reached. The system may be started at a very low blade angle, for example, 10° and gradually be brought to the running angle, for example, 25° while the web is being threaded, namely, 5 to 10 minutes. This may allow a smaller minimum load which would be a more preferred way to initiate the starting of a creping blade. The advantage would be less stripping of the dryer coating and less dryer wear both of which are desirable.
Initially, a determination is made as to the required minimum load for satisfactory creping with a new creping doctor blade, using sufficient pressure in the biasing members or air bags 70 to keep the blade holder 16 against the stops 62. The stops 62 would be set such that the desired creping angle is obtained at this minimum blade pressure. The air pressure in the blade load cylinders 21 would then be increased to a level of one fifth of the maximum load capability of the doctor blade system, as an example of one method of generating an operating curve. The maximum load of the system will be determined by the manufactures of the creping blade holder 16 and the Yankee dryer 12. Without any change in the air pressure in the biasing members or air bags 70, the holder 16 will move away from the Yankee dryer 12 changing the creping blade angle. At this point the biasing air will be increased to move the holder back toward the Yankee dryer 12 until the original creping angle is obtained. In addition, the motor 230 will rotate the shaft 232 for imparting rotation to the cam 234. The cam 234 will impart axial movement to the shaft 20 for oscillating the doctor blade 10 relative to the Yankee dryer 12.
Because of the flex in the blade, the position of the holder 16 will not be the same as in the initial setting. The holder 16 position will be slightly further away from the Yankee dryer 12 to compensate for the increased bend in the blade. This procedure will continue at two fifths, three fifths, four fifths, and maximum load, each time noting the amount of biasing pressure needed to offset the increased loading while maintaining the desired creping angle. Once these values are determined a curve can be generated of creping blade load versus biasing load. Note that this curve is only valid for this particular type of blade and its position in the holder 16 with reference to its protrusion. Different protrusions and blades of different material, makeup, and/or thickness will generate other curves.
Once a curve is generated the information can be fed into the CPU 80 of the paper machine. A program will start a creping blade at a very low load and finish at a maximum load while maintaining creping angle. This approach will not damage Yankee dryer coatings or the dryer surface. A decreased frequency of Yankee grinds and an improvement in blade life and product uniformity will be realized.
An average width of flank wear can be determined by measuring a number of blades at various stages in their life. Once the rate of wear is determined, the wear information can be fed into a CAD type system. The position of the holder can be adjusted to compensate for flank wear. The shape of the crepe blade load versus biasing load curve can then be adjusted to account for slight difference in creping angle.
Another benefit of this system is that the creping angle can be change very easily. This may be very desirable on machines that run multiple grades of product. Desirable product attributes will be achieved with different creping angles for each grade of product. A different creping angle may also be desirable for different adhesion systems within the same grade of product.
To further enhance the system benefits of reduced coating stripping and increased Yankee dryer 12 life, a program will start a new blade at a very low creping blade angle and gradually increase to the desired angle while the sheet threading process is in progress.
The present invention provides an improved doctor blade life wherein the magnitude will depend on current or modified load capability and current load. One and one-half times the current life should be easily achievable. In addition, longer times between the Yankee grinds will be achieved by the present invention. The apparatus according to the present invention exerts no pressure on the blade other than pressure which is necessary. Current systems exert an infinite load initially and maintain a higher than required load throughout the life of each blade.
The crepe angle can be changed at will depending on the numbers supplied to the central processing unit. If a machine runs more than one grade, each grade may benefit using unique creping angles. Current systems cannot achieve this results. In addition, corrections may be made to the doctor blade angle very quickly. If a nozzle plug or a wet streak causes unusual wear, an operator may turn up the pressure to compensate without changing the crepe angle. This permits extended life for the doctor blade while this problem is being corrected.
Although the present invention has been described with reference to a combination linear-rotary bearing 100A and linear bearings 51 and 52, it is contemplated in the present invention to construct the bearing 100A as a linear bearing and the bearings 51, 52 as combination linear-rotary bearings.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
|
A creping system includes a Yankee dryer rotatable about its axis, a blade support mechanism which includes (a) a pair of guide rails, (b) a fixed attitude linear bearing engaging and translatable along each of the guide rails, each fixed attitude linear bearing being mounted on a block and (c) a combination linear-rotary bearing being carried by each block, the axis of each combination linear-rotary bearing being parallel to the generators of the surface of the Yankee dryer and collinear with the axis of the other combination linear-rotary bearing. A stub shaft engages each combination linear-rotary bearing, each stub shaft being translatable along, and rotatable about, the axis of its respective combination linear-rotary bearing. A blade holder is mounted between the stub shafts, and a blade mounted on the blade holder for engagement with the surface of the Yankee dryer. The blade support mechanism allows the creping angle of the blade to be adjusted and maintained within a desired range by allowing adjustment of the creping blade angle to compensate for changes in creping angle due to flexure of the blade and flank wear on the blade.
| 3
|
REFERENCE TO RELATED APPLICATIONS
This application is a non-provisional application claiming priority from provisional application Ser. No. 60/345,163, filed Dec. 21, 2001, the entire contents of which are hereby incorporated herein by reference in its entirety.
BACKGROUND
Liver X-receptors (LXRs) are nuclear receptors that regulate the metabolism of several important lipids, including cholesterol and bile acids. Most of the cholesterol in plasma is transported on three major lipoprotein classes; VLDL cholesterol (VLDL-C), LDL cholesterol (LDL-C) and HDL cholesterol (HDL-C). Total cholesterol is the sum of all three lipoproteins. Both VLDL-C and LDL-C are associated with atherogenic processes while HDL-C is believed to facilitate cholesterol removal from tissues (e.g. atherosclerotic plaques) and thus have a protective effect on coronary heart disease.
LXR represents a novel intervention point to regulate the reverse cholesterol transport (RCT) pathway, i.e., the removal of cholesterol from peripheral tissues/cells and subsequent uptake via the liver for disposal. Removal of cellular cholesterol requires active transport of free cholesterol across the plasma membrane and onto HDL particles. This transfer of cholesterol from inside the cell and onto HDL in the plasma is mediated by ATP binding cassette 1 (ABCA1) transporter protein. The observation that LXR is a key transcriptional activator of ABCA1 in the macrophage, suggests that induction of LXR will lead to an increase in cholesterol efflux from the macrophage. In addition, it is known that LXR regulates the induction of other genes involved in RCT such as apoE and cholesterol ester transport protein (CETP), suggesting that activating the LXR pathway should also lead to increased uptake of cholesterol by the liver. Thus, activation of LXR by a small molecule ligand will lead to an up-regulation of ABCA1 and induction of the reverse cholesterol transport pathway thereby increasing cholesterol efflux to HDL-C and reducing the cholesterol content of atherosclerotic plaques.
SUMMARY OF THE INVENTION
In general, the present invention is directed to selective LXR modulators, small molecule compounds corresponding to Formula I and the isomers, tautomers, salts and prodrugs thereof:
wherein:
the X ring and the M ring are independently aromatic rings;
M 1 , M 2 , M 3 , M 4 , and M 5 are independently a bond, carbon, nitrogen, oxygen or sulfur, provided, however, no more than one of M 1 , M 2 , M 3 , M 4 , and M 5 is a bond;
M 11 , M 22 , M 33 , M 44 , and M 55 are independently an electron pair, hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, hydrocarbyloxy, substituted hydrocarbyloxy, mercapto, halo, heterocyclo, cyano, nitro, amino, acylamino, acylthio, or acyloxy, or any adjacent two of M 11 , M 22 , M 33 , M 44 , and M 55 form a fused ring with the atoms of the M ring to which they are bonded; provided, however, M 11 , M 22 , M 33 , M 44 , and M 55 is not present when M 1 , M 2 , M 3 , M 4 , or M 5 , respectively, is a bond;
p and q are independently 0, 1, or 2;
X 1 , X 2 , X 3 , and X 4 are independently a bond, carbon, nitrogen, oxygen or sulfur, provided, however, no more than one of X 1 , X 2 , X 3 , and X 4 is a bond;
X 11 , X 22 , X 33 , and X 44 , are independently an electron pair, hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, hydrocarbyloxy, substituted hydrocarbyloxy, mercapto, halo, heterocyclo, cyano, nitro, amino, acylamino, acylthio, acyloxy, or acyl; provided, however, X 11 , X 22 , X 33 , or X 44 is not present when X 1 , X 2 , X 3 or X 4 , respectively, is a bond;
X 50 is carbon, sulfur or sulfoxide,
X 51 is oxygen, sulfur, or NX 52 ,
X 52 is hydrogen, hydrocarbyl, or substituted hydrocarbyl; and
X 53 is hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocyclo, or amino.
The present invention is further directed to a process for the treatment or prevention of a condition in a mammal which is modulated by LXR. The process comprises administering to a mammal in need thereof a therapeutically effective dose of a compound of Formula I or an isomer, tautomer, salt or prodrug thereof.
Other aspects of the invention will be in part apparent and in part pointed out hereinafter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In general, the present invention is directed to small molecule compounds corresponding to Formula I and each of the other formulae disclosed herein, the isomers, tautomers, salts and prodrugs thereof and their use as LXR modulators. In particular, the LXR modulators may be used in the treatment of atherosclerosis, dyslipidemia, diabetes, Alzheimers disease or Niemann-Pick disease.
In one embodiment, the X ring and the M ring of Formula I are independently a six membered aromatic ring such as a benzene, pyridine or pyrimidine ring, or a 5-membered heteroaromatic ring such as a furan, thiophene, oxazole, pyrazole, pyrrole, thiazole, imidazole or isoxazole ring. For example, the X ring may be a 5-membered ring and the M ring may be a 6-membered ring, or vice versa.
In one embodiment, the LXR modulators correspond to Formula II:
wherein:
the X ring and the M ring are independently a 6-membered aromatic ring;
M 1 , M 2 , M 3 , M 4 , and M 5 are independently carbon or nitrogen;
M 11 , M 22 , M 33 , M 44 , and M 55 are independently an electron pair, hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, hydrocarbyloxy, substituted hydrocarbyloxy, mercapto, halo, heterocyclo, cyano, nitro, amino, acylamino, acylthio, or acyloxy, or any adjacent two of M 11 , M 22 , M 33 , M 44 , and M 55 form a fused ring with the atoms of the M ring to which they are bonded;
X 1 , X 2 , X 3 , and X 4 are independently carbon or nitrogen;
X 11 , X 22 , X 33 , and X 44 , are independently an electron pair, hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, hydrocarbyloxy, substituted hydrocarbyloxy, mercapto, halo, heterocyclo, cyano, nitro, amino, acylamino, acylthio, acyloxy or acyl;
X 50 is carbon, sulfur or sulfoxide;
X 51 is oxygen, sulfur, or NX 52 ;
X 52 is hydrogen, hydrocarbyl, or substituted hydrocarbyl; and
X 53 is hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocyclo, or amino.
In a further embodiment, the LXR modulators correspond to Formula II wherein the X ring and the M ring are benzene rings. In this embodiment, for example, the compounds correspond to Formula III:
wherein X 11 , X 22 , X 33 , X 44 , X 50 , X 51 , X 53 , M 11 , M 22 , M 33 , M 44 and M 55 are as defined in connection with Formula II. In one embodiment in which the compounds correspond to Formula III, X 50 is carbon, X 51 is oxygen, and X 53 is heterocyclo, optionally substituted alkyl, or optionally substituted phenyl. For example, X 53 may be heterocyclo (such as thienyl, pyridyl, piperidinyl, piperazinyl, or 2-oxabicyclo[2.2.1]heptane), linear or branched alkyl (such as methyl, t-butyl, isopropyl, or isobutyl), substituted alkyl (such as trichloromethyl, trifluoromethyl, (CH 2 Cl)(CH 3 ) 2 C—, (CH 3 C(O)OCH 2 )(CH 3 ) 2 C—, or (CH 2 OH)(CH 3 ) 2 C—), cycloalkyl (such as cyclohexyl, cyclopentyl, adamantyl, or methylcyclohexane), phenyl, or substituted phenyl (such as 3-chlorophenyl or methoxyphenyl). In addition, in each of the embodiments in which the compounds correspond to Formula III, one of X 11 , X 22 , X 33 , and X 44 may be hydrogen, alkyl (such as methyl), nitro, or halo (such as chloro or fluoro) while the remainder of X 11 , X 22 , X 33 , X 44 are hydrogen. In addition, in each of the embodiments in which the compounds correspond to Formula III, M 11 and M 22 , M 22 and M 33 , M 33 and M 44 , or M 44 and M 55 , and the atoms of the M ring to which they are attached may form a fused ring comprising —O—CH 2 —O—CH 2 — or —OCH 2 O— while the others of M 11 , M 22 , M 33 , M 44 and M 55 may be hydrogen, halogen (such as chloro or fluoro), or nitro; alternatively, (i) any two of M 11 , M 22 , M 33 , M 44 and M 55 may be alkoxy (such as methoxy) while the others are hydrogen, (ii) one of M 11 , M 22 , M 33 , M 44 and M 55 may be alkoxy (such as methoxy), one of M 11 , M 22 , M 33 , M 44 and M 55 may be nitro or alkyl (such as methyl) while the others are hydrogen, or (iii) one of M 11 , M 22 , M 33 , M 44 and M 55 may be alkyl (such as methyl) or substutited alkyl (such as chloro, dichloro or trichloromethyl or fluoro, difluoro or trifluoromethyl), or alkoxy (such as methoxy) while the others are hydrogen.
In a further embodiment, the LXR modulators correspond to Formula II wherein the X ring is a benzene ring and the M ring is a pyridine ring. In yet another embodiment, the X ring is a benzene ring and the M ring is a pyrimidine ring. In each of these embodiments, X 11 , X 22 , X 33 , X 44 , X 50 , X 51 , X 53 , M 11 , M 22 , M 33 , M 44 and M 55 are as defined in connection with Formula II or Formula III.
In another embodiment, the LXR modulators correspond to Formula IV:
wherein
the X ring and the M ring are independently aromatic rings;
M 1 , M 2 , M 3 , M 4 , and M 5 are independently a bond, carbon, nitrogen, oxygen or sulfur, provided, however, no more than one of M 1 , M 2 , M 3 , M 4 , and M 5 is a bond;
M 6 is hydrocarbyl, substituted hydrocarbyl or amino;
M 12 is hydrocarbyl, substituted hydrocarbyl, hydroxy, hydrocarbyloxy, substituted hydrocarbyloxy, hydrocarbylthio, substituted hydrocarbylthio or amino;
M 34 and M 35 are independently an electron pair, hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, hydrocarbyloxy, substituted hydrocarbyloxy, mercapto, halo, heterocyclo, cyano, nitro, amino, acylamino, acylthio, or acyloxy, or M 34 and M 35 are attached to adjacent atoms and form a fused ring with the atoms of the M ring to which they are bonded;
p and q are independently 0, 1, or 2;
X 1 , X 2 , X 3 , and X 4 are independently a bond, carbon, nitrogen, oxygen or sulfur, provided, however, no more than one of X 1 , X 2 , X 3 , and X 4 is a bond;
X 11 , X 22 , X 33 , and X 44 , are independently an electron pair, hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, hydrocarbyloxy, substituted hydrocarbyloxy, mercapto, halo, heterocyclo, cyano, nitro, amino, acylamino, acylthio, acyloxy, or acyl; provided, however, X 11 , X 22 , X 33 , or X 44 is not present when X 1 , X 2 , X 3 or X 4 , respectively, is a bond;
X 50 is carbon, sulfur or sulfoxide,
X 51 is oxygen, sulfur, or NX 52 ,
X 52 is hydrogen, hydrocarbyl, or substituted hydrocarbyl; and
X 53 is hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocyclo, or amino.
In one embodiment in which the LXR modulators correspond to Formula IV, the X ring and the M ring are independently a benzene, pyridine or pyrimidine ring and the sum of p and q is one. In another embodiment in which the LXR modulators correspond to Formula IV, the X ring and the M ring are independently a benzene or pyridine ring, X 50 is carbon, X 51 is oxygen and the sum of p and q is one. In another embodiment in which the LXR modulators correspond to Formula IV, the X ring and the M ring are each benzene rings and the sum of p and q is one. In another embodiment in which the LXR modulators correspond to Formula IV, the X ring and the M ring are each benzene rings, X 50 is carbon, X 51 is oxygen, and the sum of p and q is one. In a further embodiment in which the LXR modulators correspond to Formula IV, the X ring and the M ring are benzene rings, p is zero and q is one. In a further embodiment in which the LXR modulators correspond to Formula IV, the X ring and the M ring are benzene rings, X 50 is carbon, X 51 is oxygen, p is one and q is zero. In a further embodiment in which the LXR modulators correspond to Formula IV, the X ring and the M ring are benzene rings, X 50 is carbon, X 51 is oxygen, p is zero and q is one. In each of these separate embodiments in which the LXR modulators correspond to Formula IV, X 53 may be heterocyclo (such as thienyl, pyridyl, piperidinyl, piperazinyl, or 2-oxabicyclo[2.2.1]heptane), linear or branched alkyl (such as methyl, t-butyl, isopropyl, or isobutyl), substituted alkyl (such as trichloromethyl, trifluoromethyl, (CH 2 Cl)(CH 3 ) 2 C—, (CH 3 C(O)OCH 2 )(CH 3 ) 2 C—, or (CH 2 OH)(CH 3 ) 2 C—), cycloalkyl (such as cyclohexyl, cyclopentyl, adamantyl, or methylcyclohexane), phenyl, or substituted phenyl such as 3-chlorophenyl or methoxyphenyl. In addition, in each of these separate embodiments, one of X 11 , X 22 , X 33 , X 44 may be hydrogen, alkyl (such as methyl), nitro, or halo (such as chloro or fluoro) while the remainder of X 11 , X 22 , X 33 , X 44 are hydrogen. In addition, in each of these separate embodiments, M 12 may be optionally substituted alkoxy, optionally substituted alkylthio, optionally substituted alkylamino, or optionally substituted hydrocarbyl.
In a further embodiment, the LXR modulators correspond to Formula V:
wherein
X 25 and X 26 are independently hydrogen, hydrocarbyl, substituted alkyl, nitro or halo,
M 12 is alkoxy, alkylthio, amino, hydrocarbyl or substituted hydrocarbyl;
M 22 is hydrogen, hydrocarbyl or substituted hydrocarbyl;
M 34 and M 35 are independently hydrogen, alkyl, substituted alkyl, halogen, or nitro, or are attached to adjacent carbon atoms and, in combination with these adjacent carbon atoms, define a fused ring; and
X 53 is hydrocarbyl, substituted hydrocarbyl or heterocyclo.
For example, X 25 and X 26 independently may be hydrogen, methyl, nitro, chloro or fluoro, M 12 may be methoxy, alkylthio, alkyl or substituted alkyl, and M 34 and M 35 independently may be hydrogen, alkyl, substituted alkyl, chloro, fluoro, or nitro. By way of further example, M 34 and M 35 may be attached to adjacent carbon atoms and, in combination with these adjacent carbon atoms define a fused ring. By way of further example, in each of these separate embodiments in which the compound corresponds to Formula V, X 53 may be heterocyclo (such as thienyl, pyridyl, piperidinyl, piperazinyl, 2-oxabicyclo[2.2.1]heptane), linear or branched alkyl (such as methyl, t-butyl, isopropyl, or isobutyl), substituted alkyl (such as trichloromethyl, trifluoromethyl, (CH 2 Cl)(CH 3 ) 2 C—, (CH 3 C(O)OCH 2 )(CH 3 ) 2 C—, or (CH 2 OH)(CH 3 ) 2 C—), cycloalkyl (such as cyclohexyl, cyclopentyl, adamantyl, or methylcyclohexane), phenyl, or substituted phenyl (such as 3-chlorophenyl or methoxyphenyl). By way of further example, in each of these separate embodiments in which the compound corresponds to Formula V, one of X 25 and X 26 may be hydrogen and/or one of M 34 and M 35 may be hydrogen.
In a further embodiment, the LXR modulators correspond to Formula VI:
wherein:
M 13 and M 14 and the carbon atoms to which they are attached define a five or six-membered fused ring;
X 25 and X 26 are independently hydrogen, alkyl, substituted alkyl, nitro or halo,
M 34 is hydrogen, alkyl, substituted alkyl, halogen, or nitro; and
X 53 is hydrocarbyl, substituted hydrocarbyl or heterocyclo.
For example, in one embodiment in which the compounds correspond to structure VI, the ring atoms are selected from carbon, nitrogen, oxygen and sulfur. For example the five or six-membered fused ring incorporating M 13 and M 14 may comprise —O—CH 2 —O—CH 2 — when the ring is a six membered ring, or —O—CH 2 —O— when the ring is a five membered ring. In each of these and other embodiments in which the compounds correspond to structure VI, X 25 and X 26 independently may be hydrogen, methyl, nitro, chloro or fluoro, and M 34 may be hydrogen, alkyl, substituted alkyl, chloro, fluoro, or nitro. By way of further example, in each of these separate embodiments in which the compound corresponds to Formula VI, X 53 may be heterocyclo (such as thienyl, pyridyl, piperidinyl, piperazinyl, 2-oxabicyclo[2.2.1]heptane), linear or branched alkyl (such as methyl, t-butyl, isopropyl, or isobutyl), substituted alkyl (such as trichloromethyl, trifluoromethyl, (CH 2 Cl)(CH 3 ) 2 C—, (CH 3 C(O)OCH 2 )(CH 3 ) 2 C—, or (CH 2 OH)(CH 3 ) 2 C—), cycloalkyl (such as cyclohexyl, cyclopentyl, adamantyl, or methylcyclohexane), phenyl, or substituted phenyl (such as 3-chlorophenyl or methoxyphenyl). By way of further example, in each of these separate embodiments in which the compound corresponds to Formula VI, one of X 25 and X 26 may be hydrogen.
In another embodiment, the LXR modulators correspond to Formula VII:
wherein
the X ring and the M ring are independently aromatic rings;
M 1 , M 2 , M 3 , M 4 , and M 5 are independently a bond, carbon, nitrogen, oxygen or sulfur, provided, however, no more than one of M 1 , M 2 , M 3 , M 4 , and M 5 is a bond;
M 15 and M 16 are independently hydrogen, hydrocarbyl, substituted hydrocarbyl, acyl, or heterocyclo, provided M 15 and M 16 are not each acyl;
M 34 and M 35 are independently an electron pair, hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, hydrocarbyloxy, substituted hydrocarbyloxy, mercapto, halo, heterocyclo, cyano, nitro, amino, acylamino, acylthio, or acyloxy, or M 34 and M 35 are bonded to adjacent atoms and form a fused ring with the atoms of the M ring to which they are bonded;
p and q are independently 0, 1, or 2;
X 1 , X 2 , X 3 , and X 4 are independently a bond, carbon, nitrogen, oxygen or sulfur, provided, however, no more than one of X 1 , X 2 , X 3 , and X 4 is a bond;
X 11 , X 22 , X 33 , and X 44 , are independently an electron pair, hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, hydrocarbyloxy, substituted hydrocarbyloxy, mercapto, halo, heterocyclo, cyano, nitro, amino, acylamino, acylthio, acyloxy, or acyl; provided, however, X 11 , X 22 , X 33 , or X 44 is not present when X 1 , X 2 , X 3 or X 4 , respectively, is a bond;
X 50 is carbon, sulfur or sulfoxide,
X 51 is oxygen, sulfur, or NX 52 ,
X 52 is hydrogen, hydrocarbyl, or substituted hydrocarbyl; and
X 53 is hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocyclo, or amino.
In one embodiment in which the LXR modulators correspond to Formula VII, the X ring and the M ring are independently benzene or pyridine rings and the sum of p and q is one. In another embodiment in which the LXR modulators correspond to Formula VII, the X ring and the M ring are independently benzene or pyridine rings, X 50 is carbon, X 51 is oxygen and the sum of p and q is one. In another embodiment in which the LXR modulators correspond to Formula VII, the X ring and the M ring are benzene rings and the sum of p and q is one. In another embodiment in which the LXR modulators correspond to Formula VII, the X ring and the M ring are benzene rings, X 50 is carbon, X 51 is oxygen, and the sum of p and q is one. In a further embodiment in which the LXR modulators correspond to Formula VII, the X ring and the M ring are benzene rings, p is zero and q is one. In a further embodiment in which the LXR modulators correspond to Formula VII, the X ring and the M ring are benzene rings, X 50 is carbon, X 51 is oxygen, p is zero and q is one. In general, in each of these separate embodiments in which the LXR modulators correspond to Formula VII, X 11 , X 22 , X 33 , X 44 , X 53 , M 34 and M 35 are as defined in connection with Formula VII. Optionally, in each of these embodiments in which the LXR modulator corresponds to Formula VII, X 53 may be heterocyclo (such as thienyl, pyridyl, piperidinyl, piperazinyl, or 2-oxabicyclo[2.2.1]heptane), linear or branched alkyl (such as methyl, t-butyl, isopropyl, or isobutyl), substituted alkyl (such as trichloromethyl, trifluoromethyl, (CH 2 Cl)(CH 3 ) 2 C—, (CH 3 C(O)OCH 2 )(CH 3 ) 2 C—, or (CH 2 OH)(CH 3 ) 2 C—), cycloalkyl (such as cyclohexyl, cyclopentyl, adamantyl, or methylcyclohexane), phenyl, or substituted phenyl (such as 3-chlorophenyl or methoxyphenyl). In addition, in each of these separate embodiments in which the LXR modulator corresponds to Formula VII, one of X 11 , X 22 , X 33 , X 44 may be hydrogen, alkyl (such as methyl), nitro, or halo (such as chloro or fluoro) while the remainder of X 11 , X 22 , X 33 , X 44 may be hydrogen.
In one embodiment in which the compounds correspond to Formula VII, M 15 is hydrogen and M 16 is —C(═O)M 17 wherein M 17 is hydrocarbyl, substituted hydrocarbyl, hydrocarbyloxy, substituted hydrocarbyloxy, or heterocyclo. In this embodiment, X 11 , X 22 , X 33 , X 44 , X 53 , M 34 and M 35 are as previously in each of the separate embodiments defined in connection with Formula VII.
In a further embodiment, the LXR modulators correspond to Formula VIII:
wherein:
M 15 and M 16 are independently hydrogen, hydrocarbyl, substituted hydrocarbyl, or acyl (provided M 15 and M 16 are not each acyl), and X 25 , X 26 , X 53 , M 34 and M 35 are as previously defined in connection with Formula VII. In one embodiment in which the LXR modulator corresponds to Formula VIII, X 25 and X 26 are independently hydrogen, alkyl (such as methyl), nitro, or halo (such as chloro or fluoro), M 34 and M 35 are independently hydrogen, alkyl, substituted alkyl, halogen (such as chloro or fluoro), or nitro; X 53 may be heterocyclo (such as thienyl, pyridyl or 2-oxabicyclo[2.2.1]heptane), linear or branched alkyl (such as methyl, t-butyl, isopropyl, or isobutyl), substituted alkyl (such as trichloromethyl, trifluoromethyl, (CH 2 Cl)(CH 3 ) 2 C—, (CH 3 C(O)OCH 2 )(CH 3 ) 2 C—, or (CH 2 OH)(CH 3 ) 2 C—), cycloalkyl (such as cyclohexyl, cyclopentyl, adamantyl, or methylcyclohexane), phenyl, or substituted phenyl (such as 3-chlorophenyl or methoxyphenyl). By way of further example, in each of these separate embodiments in which the compound corresponds to Formula VIII, one of X 25 and X 26 may be hydrogen and/or one of M 34 and M 35 may be hydrogen.
Another aspect of the present invention are the prodrugs of the compounds corresponding to the formulae disclosed herein, which are converted under physiological conditions to the biologically active drug by any of a number of chemical and biological mechanisms. In general terms, these prodrug conversion mechanisms are hydrolysis, reduction, oxidation, and elimination.
A further aspect of the invention encompasses conversion of the prodrug to the biologically active drug by elimination of the prodrug moiety. Generally speaking, in this embodiment the prodrug moiety is removed under physiological conditions with a chemical or biological reaction. The elimination results in removal of the prodrug moiety and liberation of the biologically active drug. Any compound of the present invention corresponding to any of the formulas disclosed herein may undergo any combination of the above detailed mechanisms to convert the prodrug to the biologically active compound. For example, a particular compound may undergo hydrolysis, oxidation, elimination, and reduction to convert the prodrug to the biologically active compound. Equally, a particular compound may undergo only one of these mechanisms to convert the prodrug to the biologically active compound.
The compounds of the present invention can exist in tautomeric, geometric or stereoisomeric forms. The present invention contemplates all such compounds, including cis- and trans-geometric isomers, E- and Z-geometric isomers, R- and S-enantiomers, diastereomers, d-isomers, l-isomers, the racemic mixtures thereof and other mixtures thereof, as falling within the scope of any of the formulae disclosed herein. The terms “cis” and “trans”, as used herein, denote a form of geometric isomerism in which two carbon atoms connected by a double bond will each have a hydrogen atom on the same side of the double bond (“cis”) or on opposite sides of the double bond (“trans”). Some of the compounds described contain alkenyl groups, and are meant to include both cis and trans or “E” and “Z” geometric forms. Furthermore, some of the compounds described contain one or more stereocenters and are meant to include R, S, and mixtures or R and S forms for each stereocenter present.
Also included in the present invention are the pharmaceutically acceptable salts of any compound having corresponding to any of the formulas disclosed herein and the isomers, tautomers, and prodrugs thereof. The term “pharmaceutically-acceptable salt” includes commonly used to form alkali metal salts and to form addition salts of free acids or free bases. The nature of the salt is not critical, provided that it is pharmaceutically acceptable. Suitable pharmaceutically acceptable acid addition salts of the compounds may be prepared from an inorganic acid or from an organic acid. Examples of such inorganic acids are hydrochloric, hydrobromic, hydroiodic, nitric, carbonic, sulfuric and phosphoric acid. Appropriate organic acids may be selected from aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, carboxylic and sulfonic classes of organic acids, examples of which are formic, acetic, propionic, succinic, glycolic, gluconic, lactic, malic, tartaric, citric, ascorbic, glucoronic, maleic, fumaric, pyruvic, aspartic, glutamic, benzoic, anthranilic, mesylic, salicylic, p-hydroxybenzoic, phenylacetic, mandelic, embonic (pamoic), methanesulfonic, ethylsulfonic, benzenesulfonic, sulfanilic, stearic, cyclohexylaminosulfonic, algenic, and galacturonic acid. Suitable pharmaceutically-acceptable base addition salts of the compounds include metallic salts made from aluminum, calcium, lithium, magnesium, potassium, sodium and zinc or organic salts made from N,N′-dibenzylethyleneldiamine, choline, chloroprocaine, diethanolamine, ethylenediamine, meglumine (N-methylglucamine) and procain. All of these salts may be prepared by conventional means from the corresponding compound by reacting, for example, the appropriate acid or base with the selected compound of any of the formulae disclosed herein or the prodrug, isomer, or tautomer thereof.
The present invention also comprises a pharmaceutical composition comprising a therapeutically effective amount of the compound of the invention in association with at least one pharmaceutically acceptable carrier, adjuvant or diluent. Pharmaceutical compositions of the present invention can comprise the active compounds of any of the formulae disclosed herein or the prodrug, isomer, tautomer or prodrug thereof in association with one or more non-toxic, pharmaceutically-acceptable carriers and/or diluents and/or adjuvants (collectively referred to herein as “carrier” materials) and, if desired, other active ingredients. The compostions of the present invention may be administered by any suitable route, preferably in the form of a pharmaceutical composition adapted to such a route, and in a dose effective for the treatment intended.
Synthesis
As depicted in the schemes below, compounds of the present invention can be prepared by alkylation of (i) to give an amine (iii) which can undergo acylation with an acid chloride or anhydride to give the target compounds (iv). Additional compounds can be prepared by tin chloride reduction of (v) to give (vi) which can undergo reductive alkylation to form (vii) or coupling to an acid chloride or anhydride to give (viii).
Administration
The LXR modulators useful in the practice of the present invention can be formulated into pharmaceutical compositions and administered by any means that will deliver a therapeutically effective dose. Such compositions can be administered orally, parenterally, intranasally, by inhalation spray, rectally, intradermally, transdermally, or topically in dosage unit formulations containing conventional nontoxic pharmaceutically acceptable carriers, adjuvants, and vehicles as desired. Topical administration may also involve the use of transdermal administration such as transdermal patches or iontophoresis devices. The term parenteral as used herein includes subcutaneous, intravenous, intramuscular, or intrasternal injection, or infusion techniques. Formulation of drugs is discussed in, for example, Hoover, John E., Remington's Pharmaceutical Sciences , Mack Publishing Co., Easton, Pa. (1975), and Liberman, H. A. and Lachman, L., Eds., Pharmaceutical Dosage Forms , Marcel Decker, New York, N.Y. (1980).
Injectable preparations, for example, sterile injectable aqueous or oleaginous suspensions, can be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a nontoxic parenterally acceptable diluent or solvent. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution, and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed, including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid are useful in the preparation of injectables. Dimethyl acetamide, surfactants including ionic and non-ionic detergents, and polyethylene glycols can be used. Mixtures of solvents and wetting agents such as those discussed above are also useful.
Suppositories for rectal administration of the compounds discussed herein can be prepared by mixing the active agent with a suitable non-irritating excipient such as cocoa butter, synthetic mono-, di-, or triglycerides, fatty acids, or polyethylene glycols which are solid at ordinary temperatures but liquid at the rectal temperature, and which will therefore melt in the rectum and release the drug.
Solid dosage forms for oral administration may include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the compounds are ordinarily combined with one or more adjuvants appropriate to the indicated route of administration. If administered per os, the compounds can be admixed with lactose, sucrose, starch powder, cellulose esters of alkanoic acids, cellulose alkyl esters, talc, stearic acid, magnesium stearate, magnesium oxide, sodium and calcium salts of phosphoric and sulfuric acids, gelatin, acacia gum, sodium alginate, polyvinylpyrrolidone, and/or polyvinyl alcohol, and then tableted or encapsulated for convenient administration. Such capsules or tablets can contain a controlled-release formulation as can be provided in a dispersion of active compound in hydroxypropylmethyl cellulose. In the case of capsules, tablets, and pills, the dosage forms can also comprise buffering agents such as sodium citrate, or magnesium or calcium carbonate or bicarbonate. Tablets and pills can additionally be prepared with enteric coatings.
For therapeutic purposes, formulations for parenteral administration can be in the form of aqueous or non-aqueous isotonic sterile injection solutions or suspensions. These solutions and suspensions can be prepared from sterile powders or granules having one or more of the carriers or diluents mentioned for use in the formulations for oral administration. The compounds can be dissolved in water, polyethylene glycol, propylene glycol, ethanol, corn oil, cottonseed oil, peanut oil, sesame oil, benzyl alcohol, sodium chloride, and/or various buffers. Other adjuvants and modes of administration are well and widely known in the pharmaceutical art.
Liquid dosage forms for oral administration can include pharmaceutically acceptable emulsions, solutions, suspensions, syrups, and elixirs containing inert diluents commonly used in the art, such as water. Such compositions can also comprise adjuvants, such as wetting agents, emulsifying and suspending agents, and sweetening, flavoring, and perfuming agents.
The amount of active ingredient that can be combined with the carrier materials to produce a single dosage of the LXR modulator will vary depending upon the patient and the particular mode of administration. In general, the pharmaceutical compositions may contain a LXR modulator in the range of about 1 and 2500 mg, more typically, in the range of about 5 and 1000 mg and still more typically, between about 10 and 500 mg. A daily dose of about 0.1 to 50 mg/kg body weight, or more typically, between about 0.1 and about 25 mg/kg body weight and even more typically, from about 0.5 to 10 mg/kg body weight, may be appropriate. The daily dose can be administered in one to about four doses per day. Those skilled in the art will appreciate that dosages may also be determined with guidance from Goodman & Goldman's The Pharmacological Basis of Therapeutics , Ninth Edition (1996), Appendix II, pp. 1707-1711 and from Goodman & Goldman's The Pharmacological Basis of Therapeutics , Tenth Edition (2001), Appendix II, pp.475-493.
Definitions
The term “acyl,” as used herein alone or as part of another group, denotes the moiety formed by removal of the hydroxyl group from the —COOH group of an organic carboxylic acid, e.g., RC(O)— wherein R is R a , R a O—, R a S—, or R a R b N—, R a and R b are independently hydrogen, hydrocarbyl, substituted hydrocarbyl, or heterocyclo and “—” denotes the point of attachment.
The term “acylamino,” as used herein alone or as part of another group, denotes an acyl group as defined above, bonded through a nitrogen atom, e.g., RC(O)N(R c )— wherein R is as defined in connection with the term “acyl”, R c is hydrogen, hyrocarbyl, or substituted hydrocarbyl, and “—” denotes the point of attachment.
The term “acyloxy” as used herein alone or as part of another group, denotes an acyl group as defined above, bonded through an oxygen atom (—O—), e.g., RC(O)O— wherein R is as defined in connection with the term “acyl” and “—” denotes the point of attachment.
The term “acylthio” as used herein alone or as part of another group, denotes an acyl group as defined above, bonded through a sulfur atom (—S—), e.g., RC(O)S— wherein R is as defined in connection with the term “acyl” and “—” denotes the point of attachment.
The term “amino” as used herein alone or as part of another group shall denote a primary, secondary or tertiary amine which may optionally be hydrocarbyl, substituted hydrocarbyl or heteroatom substituted. Specifically included are secondary or tertiary amine nitrogens which are members of a heterocyclic ring. Also specifically included, for example, are secondary or tertiary amino groups substituted by an acyl moiety.
Unless otherwise indicated, the alkyl groups described herein are preferably lower alkyl containing from one to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain or cyclic and include methyl, ethyl, propyl, isopropyl, butyl, hexyl and the like.
Unless otherwise indicated, the alkenyl groups described herein are preferably lower alkenyl containing from two to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain or cyclic and include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, hexenyl, and the like.
Unless otherwise indicated, the alkynyl groups described herein are preferably lower alkynyl containing from two to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain and include ethynyl, propynyl, butynyl, isobutynyl, hexynyl, and the like.
The term “aromatic” shall mean aryl or heteroaromatic.
The terms “aryl” or “ar” as used herein alone or as part of another group denote optionally substituted carbocyclic aromatic groups, preferably monocyclic or bicyclic groups containing from 6 to 12 carbon atoms in the ring portion, such as phenyl, biphenyl, naphthyl, substituted phenyl, substituted biphenyl or substituted naphthyl. Phenyl and substituted phenyl are the more preferred aryl.
The terms “halogen” or “halo” as used herein alone or as part of another group refer to chlorine, bromine, fluorine, and iodine.
The term “heteroaromatic” as used herein alone or as part of another group denote optionally substituted aromatic groups having at least one carbon atom and at least a heteroatom in at least one ring, and preferably 5 or 6 atoms in each ring. The heteroaromatic group preferably has 1 or 2 oxygen atoms, 1 or 2 sulfur atoms, and/or 1 to 4 nitrogen atoms in the ring, and may be bonded to the remainder of the molecule through a carbon or heteroatom. Exemplary heteroaromatics include furyl, thienyl, pyridyl, oxazolyl, pyrrolyl, indolyl, quinolinyl, or isoquinolinyl and the like. Exemplary substituents include one or more of the following groups: hydrocarbyl, substituted hydrocarbyl, keto, hydroxy, protected hydroxy, acyl, acyloxy, alkoxy, alkenoxy, alkynoxy, aryloxy, halogen, amido, amino, nitro, cyano, thiol, ketals, acetals, esters and ethers.
The term “heteroatom” shall mean atoms other than carbon and hydrogen.
The terms “heterocyclo” or “heterocyclic” as used herein alone or as part of another group denote optionally substituted, fully saturated or unsaturated, monocyclic or bicyclic, aromatic or nonaromatic groups having at least one heteroatom in at least one ring, and preferably 5 or 6 atoms in each ring. The heterocyclo group preferably has 1 or 2 oxygen atoms, 1 or 2 sulfur atoms, and/or 1 to 4 nitrogen atoms in the ring, and may be bonded to the remainder of the molecule through a carbon or heteroatom. Exemplary heterocyclo include heteroaromatics such as furyl, thienyl, pyridyl, oxazolyl, pyrazolyl, pyrrolyl, indolyl, quinolinyl, thiazolyl, isoquinolinyl and the like. Exemplary substituents include one or more of the following groups: hydrocarbyl, substituted hydrocarbyl, keto, hydroxy, protected hydroxy, acyl, acyloxy, alkoxy, alkenoxy, alkynoxy, aryloxy, halogen, amido, amino, nitro, cyano, thiol, ketals, acetals, esters and ethers.
The terms “hydrocarbon” and “hydrocarbyl” as used herein describe organic compounds or radicals consisting exclusively of the elements carbon and hydrogen. These moieties include alkyl, alkenyl, alkynyl, and aryl moieties. These moieties also include alkyl, alkenyl, alkynyl, and aryl moieties substituted with other aliphatic, cyclic or aryl hydrocarbon groups, such as alkaryl, alkenaryl and alkynaryl. Unless otherwise indicated, these moieties preferably comprise 1 to 20 carbon atoms.
The “substituted” alkyl, alkenyl, alkynyl, aryl, hydrocarbyl or heterocyclo moieties described herein are moieties which are substituted with a hydrocarbyl moiety, a substituted hydrocarbyl moiety, a heteroatom, or a heterocyclo. For example, substituents include moieties in which a carbon atom is substituted with a hetero atom such as nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or a halogen atom. These substituents include halogen, heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, keto, acyl, acyloxy, nitro, amino, amido, nitro, cyano, thiol, ketals, acetals, esters and ethers.
The following examples illustrate the invention.
EXAMPLE 1
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)thiophene-2-carboxamide
2-aminothiophenol (0.4 mmol) and PS-DIEA resin (0.35 g, 3.76 mmol/g) were combined in dichloromethane (4 mL) and agitated for 10 min. 5-chloro-6-(chloromethyl)-1,3-benzodioxole (0.3 mmol) was added and the reaction agitated for a further 3 h. Reaction was treated with MP BH 4 − resin (Argonaut 3.16 mmol/g) for 2 h then filtered.
The filtrate was combined with triethylamine (0.1 mL) and thiophene-2-carbonyl chloride (0.4 mmol) and agitated for 18 h. The solvent was removed under a stream of nitrogen and the residue was purified by reverse phase chromatography to give the title product. 1 H NMR (CDCl 3 ) δ 9.02 (s, 1 H), 8.45 (dd, 1 H), 7.60 (dd, 1 H), 7.55 (dd, 1 H), 7.51 (dd, 1 H), 7.42-7.39 (m, 1 H), 7.14 (dd, 1 H), 7.12-7.08 (m, 1 H), 6.51 (s, 1 H), 6.13 (s, 1 H), 5.85 (s, 2 H), 3.90 (s, 2 H); MS (ESI+) for C 19 H 14 ClNO 3 S 2 m/z 404 (M+H) + .
EXAMPLE 2
N-{2-[(2-methoxy-5-nitrobenzyl)thio]phenyl}thiophene-2-carboxamide
Prepared in the manner of Example 1, except 2-(bromomethyl)-1-methoxy-4-nitrobenzene was substituted for 5-chloro-6-(chloromethyl)-1,3-benzodioxole and the compound was purifed by trituration with methanol. 1 H NMR (CDCl 3 ) δ 9.10 (s, 1 H), 8.42 (dd, 1 H), 7.98 (dd, 1 H), 7.80 (d, 1 H), 7.55 (dd, 1 H), 7.51 (dd, 1 H), 7.48 (dd, 1 H), 7.40-7.35 (m, 1 H), 7.10 (dd, 1 H), 7.08-7.03 (m, 1 H), 6.67 (d, 1 H), 3.97 (s, 2 H), 3.59 (s, 3 H); MS (ESI+) for C 19 H 16 N 2 O 4 S 2 m/z 401 (M+H) + .
EXAMPLE 3
N-{2-[(2-methoxybenzyl)thio]phenyl}thiophene-2-carboxamide
Prepared in the manner of Example 1, except that 1-(bromomethyl)-2-methoxybenzene was substituted for 5-chloro-6-(chloromethyl)-1,3-benzodioxole. 1 H NMR (CDCl 3 ) δ 9.21 (s, 1 H), 8.47 (dd, 1 H), 7.55-7.51 (m, 2 H), 7.42 (1, 1 H), 7.39-7.34 (m, 1 H), 7.11-7.01 (m, 3 H), 6.79 (dd, 1 H), 6.70-6.63 (m, 2 H), 3.95 (s, 2 H), 3.62 (s, 3 H); MS (ESI+) for C 19 H 17 NO 2 S 2 m/z 356 (M+H) + .
EXAMPLE 4
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)acetamide
2-aminothiophenol (0.4 mmol) and PS-DIEA resin (0.35 g, 3.76 mmol/g) were combined in dichloromethane (4 mL) and agitated for 10 min. 5-chloro-6-(chloromethyl)-1,3-benzodioxole (0.3 mmol) was added and the reaction agitated for a further 3 h. Reaction was treated with MP BH 4 − resin (Argonaut 3.16 mmol/g) for 2 h then filtered. The filtrate was combined with triethylamine (0.4 mmol), PS-DMAP resin (0.1 g) and acetyl chloride (0.4 mmol). Agitate for 18 h then treat the reaction with PS-trisamine resin for 4 h, filter and remove the solvent under a stream of nitrogen. The residue was purified by reverse phase chromatography. 1 H NMR (CDCl 3 ) δ 8.38-8.32 (m, 2 H), 7.52 (m, 1 H), 7.38-7.32 (m, 1 H), 7.07-7.02 (m, 1 H), 6.83 (s, 1 H), 6.25 (s, 1 H), 5.93 (s, 2 H), 3.90 (s, 2 H), 2.09 (s, 3 H);MS (ESI+) for C 16 H 14 ClNO 3 S m/z 336 (M+H) + .
EXAMPLE 5
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)-2,2,2-trifluoroacetamide
Prepared in the manner of Example 4, except trifluoroacetic acid anhydride was substituted for acetyl chloride. 1 H NMR (CDCl 3 ) δ 9.24 (s, 1 H), 8.34 (dd, 1 H), 7.62 (dd, 1 H), 7.46-7.40 (m, 1 H), 7.22-7.18 (m, 1 H), 6.80 (s, 1 H), 6.21 (s, 1 H), 5.91 (s, 2 H), 3.92 (s, 2 H);MS (ESI+) for C 16 H 11 ClF 3 NO 3 S m/z 389 (M+H) + .
EXAMPLE 6
N-(2-{[(6-chloro-4H-1,3-benzodioxin-8-yl)methyl]thio}phenyl)-2,2-dimethylpropanamide
Step 1
2-{[(6-chloro-4H-1,3-benzodioxin-8-yl)methyl]thio}aniline hydrochloride
2-aminothiophenol (1.25 g, 10 mmol), 6-chloro-8-(chloromethyl)-4H-1,3-benzodioxine (2.17 g, 10 mmol) and potassium carbonate (4.10 g, 30 mmol) were combined in absolute ethanol (100 mL) and stirred 18 h. Dilute with ethyl acetate and wash with saturated sodium bicarbonate solution then brine. The solution was dried over sodium sulfate and the solvent removed in vacuo. The residue was dissolved in methanol and treated with MP BH 4 − resin (Argonaut 3.16 mmol/g) and potassium carbonate for 48 h. The mixture was filtered and the solvent removed in vacuo. The resulting oil was dissolved in dichloromethane and passed through a 5 g plug of silica gel. The solvent was removed in vacuo and the residue was precipitated from diethyl ether with a solution of hydrogen chloride in dioxane to give the product as an off white powder, 2.52 g (74%). MS (ESI+) for C 15 H 14 ClNO 2 S m/z 308 (M+H) + .
Step 2
N-(2-{[(6-chloro-4H-1,3-benzodioxin-8-yl)methyl]thio}phenyl)-2,2-dimethylpropanamide
The product from step 1 (75 mg, 0.22 mmol) was dissolved in a mixture of dichloromethane and diisopropyl ethyl amine (4 mL , ˜40:1), PS DMAP resin (0.10 g, Argonaut 1.41 mmol/g) was added in followed by 2,2-dimethylpropanoyl chloride (0.15 mL, 1.25 mmol). The reaction was agitated for 24 hours and then treated with PS trisamine (Argonaut 4.27 mmol/g) for 6 h filtered and the solvent removed under a stream of nitrogen. The residue was chromatographed on silica to give the title product 55 mg (65%). 1 H NMR (CDCl 3 ) δ 9.87 (s, 1 H), 8.45 (dd, 1 H), 7.39 (dd, 1 H), 7.33 (dt, 1 H), 7.00 (dt, 1 H), 6.80 (dd, 2 H), 4.98 (s, 2 H), 4.77 (s, 2 H), 3.84 (s, 2 H), 1.28 (s, 9 H); MS (ESI+) for C 20 H 22 ClNO 3 S m/z 392 (M+H) + .
EXAMPLE 7
N-(2-{[(6-chloro-4H-1,3-benzodioxin-8-yl )methyl]thio}phenyl)-2-methylpropanamide
Prepared in the manner of Example 6, step 2, except 2-methylpropanoyl chloride was substituted for 2,2-dimethylpropanoyl chloride. 1 H NMR (CDCl 3 ) δ 8.51 (s, 1 H), 8.42 (dd, 1 H), 7.41 (dd, 1 H), 7.37-7.31 (m, 1 H), 6.82 (m, 2 H), 5.0 (s, 2 H), 4.78 (s, 2 H), 3.83 (s, 2 H), 2.50-2.42 (m, 1 H), 1.25 (s, 3 H), 1.22 (s, 3 H); MS (ESI+) for C 19 H 20 ClNO 3 m/z 378 (M+Na) + .
EXAMPLE 8
N-(2-{[(6-chloro-4H-1,3-benzodioxin-8-yl)methyl]thio}phenyl)-3-methylbutanamide
Prepared in the manner of Example 6, step 2, except 3-methylbutanoyl chloride was substituted for 2,2-dimethylpropanoyl chloride. 1 H NMR (CDCl 3 ) δ 8.41-8.35 (m, 2 H), 7.40 (dd, 1 H), 7.38-7.31 (m, 1 H), 7.02-6.97 (m, 1 H), 6.35-6.32 (m, 2 H), 4.98 (s, 2 H), 4.79 (s, 2 H), 3.84 (s, 2 H), 2.18-2.16 (m, 3 H), 1.02-1.00 (m, 6 H); MS (ESI+) for C 20 H 22 ClNO 3 S m/z 392 (M+H) + .
EXAMPLE 9
N-(2-{[(7-methoxy-2-oxo-2H-chromen-4-yl)methyl]thio}phenyl)-2,2-dimethylpropanamide
Prepared in the manner of Example 4, except 4-(bromomethyl)-7-methoxy-2H-chromen-2-one was substituted for 5-chloro-6-(chloromethyl)-1,3-benzodioxole and 2,2-dimethylpropanoyl chloride was substituted for acetyl chloride. 1 H NMR (CDCl 3 ) δ 8.60 (s, 1 H), 8.45 (dd, 1 H), 7.45 (d, 1 H), 7.42-7.34 (m, 2 H), 7.04-7.00 (m, 1 H), 6.87-6.83 (m, 2 H), 5.70 (s, 1 H), 3.90 (s, 2 H), 3.88 (s, 3 H), 1.16 (s, 9 H); MS (ESI+) for C 22 H 23 NO 4 S m/z 398 (M+H) + .
EXAMPLE 10
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)-2,2-dimethylpropanamide
Prepared in the manner of Example 4, except 2,2-dimethylpropanoyl chloride was substituted for acetyl chloride. 1 H NMR (CDCl 3 ) δ 8.81 (s, 1 H), 8.45 (dd, 1 H), 7.47 (dd, 1 H), 7.36-7.31 (m, 1 H), 7.04-6.99 (m, 1 H), 6.81 (s, 1 H), 6.24 (s, 1 H), 5.92 (s, 2 H), 3.93 (s, 2 H), 1.27 (s, 9 H);MS (ESI+) for C 19 H 20 ClNO 3 S m/z 378 (M+H) + .
EXAMPLE 11
N-{2-[(2-methoxy-5-nitrobenzyl)thio]phenyl}-2,2-dimethylpropanamide
Prepared in the manner of Example 4, except 2-(bromomethyl)-1-methoxy-4-nitrobenzene was substituted for 5-chloro-6-(chloromethyl)-1,3-benzodioxole and 2,2-dimethylpropanoyl chloride was substituted for acetyl chloride. 1 H NMR (CDCl 3 ) δ 8.79 (s, 1 H), 8.36 (dd, 1 H), 8.05 (dd, 1 H), 7.78 (d, 1 H), 7.28-7.20 (m, 2 H), 6.89-6.85 (m, 1 H), 6.76 (d, 1 H), 3.89 (s, 2 H), 3.68 (s, 3 H), 1.21 (s, 9 H); MS (ESI+) for C 19 H 22 N 2 O 4 S m/z 375 (M+H) + .
EXAMPLE 12
3-chloro-N-(2-{[(6-chloro-4H-1,3-benzodioxin-8-yl)methyl]thio}phenyl)-2,2-dimethylpropanamide
Prepared in the manner of Example 6, step 2, except 3-chloro-2,2-dimethylpropanoyl chloride was substituted for 2,2-dimethylpropanoyl chloride.
1 H NMR (CDCl 3 ) δ 8.93 (s, 1 H), 8.45 (dd, 1 H), 7.39 (dd, 1 H), 7.38-7.32 (m, 1 H), 7.03-6.98 (m, 1 H), 6.82 (m, 1 H), 6.78 (m, 1 H), 5.01 (s, 2 H), 4.78 (s, 2 H), 3.86 (s, 2 H), 3.68 (s, 2 H), 1.39 (s, 6 H); MS (ESI+) for C 20 H 21 Cl 2 NO 3 S m/z 426 (M+H) + .
EXAMPLE 13
N-(2-{[(6-chloro-4H-1,3-benzodioxin-8-yl)methyl]thio}phenyl)-cyclohexanecarboxamide
Prepared in the manner of Example 6, step 2, except cyclohexanecarbonyl chloride was substituted for 2,2-dimethylpropanoyl chloride. 1 H NMR (CDCl 3 ) δ 8.48 (s, 1 H), 8.42 (dd, 1 H), 7.41 (dd, 1 H), 7.35-7.30 (m, 1 H), 7.03-6.97 (m, 1 H), 6.81 (s, 2 H), 4.97 (s, 2 H), 4.78 (s, 2 H), 3.82 (s, 2 H), 2.20-2.10 (m, 1 H), 1.95-1.88 (m, 2 H), 1.88-1.79 (m, 2 H), 1.73-1.68 (m, 1 H), 1.50-1.20 (m, 5 H); MS (ESI+) for C 22 H 24 ClNO 3 S m/z 418 (M+H) + .
EXAMPLE 14
N-(2-{[(6-chloro-4H-1,3-benzodioxin-8-yl)methyl]thio}phenyl)-cyclopentanecarboxamide
Prepared in the manner of Example 6, step 2, except cyclopentanecarbonyl chloride was substituted for 2,2-dimethylpropanoyl chloride. 1 H NMR (CDCl 3 ) δ 8.45 (s, 1 H), 8.40 (dd, 1 H), 7.41 (dd, 1 H), 7.35-7.00 (m, 1 H), 7.00-6.95 (m, 1 H), 6.84-6.80 (m, 2 H), 4.97 (s, 2 H), 4.78 (s, 2 H), 3.83 (s, 2 H), 2.67-2.59 (m, 1 H), 1.98-1.58 (m, 8 H); MS (ESI+) for C 21 H 22 ClNO 3 S m/z 404 (M+H) + .
EXAMPLE 15
N-(2-{[(6-chloro-4H-1,3-benzodioxin-8-yl)methyl]thio}phenyl)-3,3-dimethylbutanamide
Prepared in the manner of Example 6, step 2, except 3,3-dimethylbutanoyl chloride was substituted for 2,2-dimethylpropanoyl chloride. 1 H NMR (CDCl 3 ) δ 8.40 (dd, 1 H), 8.31 (s, 1 H), 7.39 (dd, 1 H), 7.35-7.29 (m, 1 H), 7.01-6.96 (m, 1 H), 6.85-6.81 (m, 2 H), 4.99 (s, 2 H), 4.78 (s, 2 H), 3.82 (s, 2 H), 2.15 (s, 2 H), 1.09 (s, 9 H); MS (ESI+) for C 21 H 24 ClNO 3 S m/z 406 (M+H) + .
EXAMPLE 16
2,2,2-trichloro-N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)-acetamide
Prepared in the manner of Example 3, except 5-chloro-6-(chloromethyl)-1,3-benzodioxole was substituted for 6-chloro-8-(chloromethyl)-4H-1,3-benzodioxine in step 1 and trichloroacetyl chloride was substituted for 2,2-dimethylpropanoyl chloride in step 2. 1 H NMR (CDCl 3 ) δ 9.82 (s, 1 H), 8.35 (dd, 1 H), 7.57 (dd, 1 H), 7.45-7.40 (m, 1 H), 7.20-7.13 (m, 1 H), 6.80 (s, 1 H), 6.20 (s, 1 H), 5.92 (s, 2 H), 3.94 (s, 2 H);MS (ESI+) for C 16 H 11 Cl 4 NO 3 S m/z 462 (M+Na) + .
EXAMPLE 17
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)adamantane-1-carboxamide
Prepared in the manner of Example 3, except 5-chloro-6-(chloromethyl)-1,3-benzodioxole was substituted for 6-chloro-8-(chloromethyl)-4H-1,3-benzodioxine in step 1 and adamantane-1-carbonyl chloride was substituted for 2,2-dimethylpropanoyl chloride in step 2. 1 H NMR (CDCl 3 ) δ 8.77 (s, 1 H), 8.47 (dd, 1 H), 7.48 (dd, 1 H), 7.37-7.30 (m, 1 H), 7.04-6.98 (m, 1 H), 6.80 (s, 1 H), 6.22 (s, 1 H), 5.91 (s, 2 H), 3.92 (s, 2 H), 2.10-1.67 (series of m, 15 H); MS (ESI+) for C 25 H 26 ClNO 3 S m/z 456 (M+H) + .
EXAMPLE 18
N-(2-{[(6-chloro-4H-1,3-benzodioxin-8-yl)methyl]thio}phenyl)adamantane-1-carboxamide
Prepared in the manner of Example 3, except adamantane-1-carbonyl chloride was substituted for 2,2-dimethylpropanoyl chloride in step 2. 1 H NMR (CDCl 3 ) δ 8.80 (s, 1 H), 8.48 (dd, 1 H), 7.40 (dd, 1 H), 7.36-7.30 (m, 1 H), 7.01-6.96 (m, 1 H), 6.82-6.78 (m, 2 H), 4.97 (s, 2 H), 4.77 (s, 2 H), 3.84 (s, 2 H), 2.12-1.67 (series of m, 15 H); MS (ESI+) for C 26 H 28 ClNO 3 S m/z 470 (M+H) + .
EXAMPLE 19
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)-4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptane-1-carboxamide
Prepared in the manner of Example 3, except 5-chloro-6-(chloromethyl)-1,3-benzodioxole was substituted for 6-chloro-8-(chloromethyl)-4H-1,3-benzodioxine in step 1 and 4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptane-1-carbonyl chloride was substituted for 2,2-dimethylpropanoyl chloride in step 2. 1 H NMR (CDCl 3 ) δ 9.45 (s, 1 H), 8.42 (dd, 1 H), 7.45 (dd, 1 H), 7.41-7.34 (m, 1 H), 7.18-7.11 (m, 1 H), 6.80 (s,1 H), 6.54 (s, 1 H), 5.95 (s, 2 H), 3.96 (s, 2 H), 2.65-2.55 (m, 1 H), 2.05-1.95 (m, 2 H), 1.80-1.71 (m, 1 H), 1.16 (s, 6 H), 0.98 (s, 3 H);MS (ESI+) for C 24 H 24 ClNO 5 S m/z 474 (M+H) + .
EXAMPLE 20
2-[(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)amino]-1,1-dimethyl-2-oxoethyl acetate
Prepared in the manner of Example 3, except 5-chloro-6-(chloromethyl)-1,3-benzodioxole was substituted for 6-chloro-8-(chloromethyl)-4H-1,3-benzodioxine in step 1 and 4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptane-1-carbonyl chloride was substituted for 2-chloro-1,1-dimethyl-2-oxoethyl acetate in step 2. 1 H NMR (CDCl 3 ) δ 9.31 (s, 1 H), 8.45 (dd, 1 H), 7.45 (dd, 1 H), 7.40-7.34 (m, 1 H), 7.08-7.02 (m, 1 H), 6.82 (s, 1 H), 6.33 (s, 1 H), 5.95 (s, 2 H), 3.95 (s, 2 H), 2.18 (s, 3 H), 1.71 (s, 6 H); MS (ESI+) for C 20 H 20 ClNO 5 S m/z 422 (M+H) + .
EXAMPLE 21
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)-1-methylcyclohexanecarboxamide
Prepared in the manner of Example 4, except 1-methylcyclohexanecarbonyl chloride was substituted for acetyl chloride. MS (ESI+) for C 22 H 24 ClNO 3 S m/z 418 (M+H) + .
EXAMPLE 22
N-(2-{[(6-chloro-4H-1,3-benzodioxin-8-yl)methyl]thio}phenyl)-1-methylcyclohexanecarboxamide
Prepared in the manner of Example 6, step 2, except 1-methylcyclohexane-carbonyl chloride was substituted for 2,2 dimethylpropanoyl chloride. MS (ESI+) for C 23 H 26 ClNO 3 S m/z 432 (M+H) + .
EXAMPLE 23
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)-2-hydroxy-2-methylpropanamide
The material from Example 20 was treated with potassium carbonate in methanol overnight. The solvent was evaporated under a stream of nitrogen and the residue chromatographed on silica to give the title product. MS (ESI+) for C 18 H 18 ClNO 4 S m/z 380 (M+H) + .
EXAMPLE 24
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}-5-methylphenyl)-2,2-dimethylpropanamide
Step 1
5-chloro-6-{[(4-methyl-2-nitrophenyl)thio]methyl}-1,3-benzodioxole
1-bromo-4-methyl-2-nitrobenzene (3 mmol) dissolved in DMF (3 mL) was combined with a solution of sodium sulfide nonahydrate (3 mmol) in water 3 (mL) and stirred for 48 hours. A solution of 5-chloro-6-(chloromethyl)-1,3-benzodioxole (3 mmol) in ethyl acetate (5 mL) was added in and the reaction was agitated for another 24 hours. The reaction was diluted with ethyl acetate and washed sequentially with 0.5 N NaOH solution (7 mL×1), water (7 mL×3) and brine (7 mL×1). The solvent was removed under a stream of nitrogen and the residue crystallized from a mix of dichloromethane and hexane.
Step 2
2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}-5-methylaniline
The material from step 1 dissolved in ethanol (5 mL) was combined with a solution of tin dichloride dihydrate (12 mmol) in ethanol (5 mL) and heated to 70 for 5 h. The solvent was removed under a stream of nitrogen and the residue was redissolved in a mix of dichloromethane and 1 N NaOH solution. The mixture was applied to an Extrelut QE solid phase extraction column that was prepped with 1 N NaOH solution. The organic was collected and the solvent was removed under a stream of nitrogen. The residue was redissolved in diethyl ether and treated with 4 N HCl in dioxane. The precipate was collected to give the product as the HCl salt.
Step 3
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}-5-methylphenyl)-2,2-dimethylpropanamide
The material from step 2 was suspended in a mixture of diisopropyl ethyl amine (0.15 mL), PS-DMAP resin (50 mg), 2,2-dimethylpropanoyl chloride (0.1 mL) and dichloromethane (7 mL). The reaction was agitated overnight and then treated with PS-Trisamine resin and agitated a further 24 h. The reaction was applied to an Extrelut QE column prepped with 1N HCl, the organic was collected and evaporated under a stream of nitrogen. The residue was chromatographed on silica to afford the title product. MS (ESI+) for C 20 H 22 ClNO 3 S m/z 392 (M+H) + .
EXAMPLE 25
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}-3-methylphenyl)-2,2-dimethylpropanamide
Prepared in the manner of Example 24, except 2-chloro-1-methyl-3-nitrobenzene was substituted for 1-bromo-4-methyl-2-nitrobenzene in step 1. MS (ESI+) for C 20 H 22 ClNO 3 S m/z 392 (M+H) + .
EXAMPLE 26
N-(3-chloro-2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)-2,2-dimethylpropanamide
Prepared in the manner of Example 24, except 1,2-dichloro-3-nitrobenzene was substituted for 1-bromo-4-methyl-2-nitrobenzene in step 1. MS (ESI+) for C 19 H 19 Cl 2 NO 3 S m/z 412 (M+H) + .
EXAMPLE 27
N-(5-chloro-2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}phenyl)-2,2-dimethylpropanamide
Prepared in the manner of Example 24, except 1,4-dichloro-2-nitrobenzene was substituted for 1-bromo-4-methyl-2-nitrobenzene in step 1. MS (ESI+) for C 19 H 19 Cl 2 NO 3 S m/z 412 (M+H) + .
EXAMPLE 28
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}-5-fluorophenyl)-2,2-dimethylpropanamide
Prepared in the manner of Example 24, except 1,4-difluoro-2-nitrobenzene was substituted for 1-bromo-4-methyl-2-nitrobenzene in step 1. MS (ESI+) for C 19 H 19 ClFNO 3 S m/z 396 (M+H) + .
EXAMPLE 29
N-(2-{[(6-chloro-1,3-benzodioxol-5-yl)methyl]thio}-4,5-difluorophenyl)-2,2-dimethylpropanamide
Prepared in the manner of Example 24, except 1,2,4-trifluoro-5-nitrobenzene was substituted for 1-bromo-4-methyl-2-nitrobenzene in step 1. MS (ESI+) for C 19 H 18 ClF 2 NO 3 S m/z 414 (M+H) + .
EXAMPLES 30-47
2-amino thiophenol (20 mmol) was dissolved in dichloromethane (65 mL). The appropriate alkyl halide (20 mmol) was added along with PS-DIEA resin (8.00 g, 3.83 mmol/g, 30.64 mmol) and the mixture was agitated at room temperature overnight. The product was isolated as a stock solution in dichloromethane. This product was then acylated by using excess of the appropriate acid chloride, PS-DMAP resin, PS-DIEA in dichloromethane and agitating the reaction overnight at room temperature. PS-Trisamine was added in and the reaction agitated a further 18 h. The reaction was filtered and the filtrate was reduced under a stream of nitrogen to afford the product.
Example
Mass
Number
Structure
Compound Name(s)
Spec
30
3-chloro-N-{2-[(2-methoxy-5- nitrobenzyl)thio]phenyl}-2,2- dimethylpropanamide
409.2
31
2,2,2-trichloro-N-{2-[(2-methoxy- 5-nitrobenzyl)thio]phenyl} acetamide
435.0
32
3-chloro-N-{2-[(4-methyl-3- nitrobenzyl)thio]phenyl} benzamide
413.0
33
3-chloro-2,2-dimethyl-N-{2-[(4- methyl-3-nitrobenzyl)thio] phenyl}propanamide
393.0
34
N-{2-[(4-methyl-3-nitro benzyl) thio]phenyl} thiophene-2- carboxamide
385.0
35
2,2,2-trichloro-N-{2-[(4-methyl-3- nitrobenzyl)thio] phenyl} acetamide
419.0
36
2,2-dimethyl-N-{2-[(4-methyl-3- nitrobenzyl)thio]phenyl} propanamide
359.2
37
3-chloro-N-(2-{[3-(trifluoro methyl)benzyl]thio}phenyl) benzamide
422.0
38
3-chloro-2,2-dimethyl-N-(2-{[3- (trifluoromethyl)benzyl] thio}phenyl)propanamide
402.0
39
2,2,2-trichloro-N-(2-{[3-(trifluoro methyl)benzyl]thio}phenyl) acetamide
430.0
40
2,2-dimethyl-N-(2-{[3-(trifluoro methyl)benzyl]thio}phenyl) propanamide
368.0
41
3-chloro-N-{2-[(2,5-di methoxybenzyl)thio] phenyl}-2,2- dimethylpropanamide
394.2
42
N-{2-[(2,5-dimethoxy benzyl)thio]phenyl}- 3,3-dimethylbutanamide
374.2
43
2,2,2-trichloro-N-{2-[(2,5-di methoxybenzyl)thiol] phenyl}acetamide
440.0 (M + 23)
44
N-{2-[(2,5-dimethoxy benzyl)thio] phenyl}-2,2-dimethylpropanamide
360.2
45
N-{2-[(1,3-benzodioxol-5- ylmethyl)thio]phenyl}-3-chloro- 2,2-dimethylpropanamide
378.0
46
N-{2-[(1,3-benzodioxol-5- ylmethyl)thio]phenyl}-3,3- dimethylbutanamide
358.2
47
N-{2-[(1,3-benzodioxol-5- ylmethyl)thio]phenyl}-2,2- dimethylpropanamide
344.2
EXAMPLES 48-52
Prepared in the manner of Example 25, using the appropriate alkyl halide instead of 5-chloro-6-(chloromethyl)-1,3-benzodioxole in step 1 and using the appropriate acyl chloride instead of 2,2-dimethylpropanoyl chloride in step 3.
Example
Mass
Number
Structure
Compound Name(s)
Spec
48
3-chloro-N-(2-{[(6-chloro-1,3-benzo dioxol-5-yl)methyl]thio}-3-methyl phenyl)-2,2-dimethylpropanamide
426.0
49
3-chloro-N-(2-{[(6-chloro-4H-1,3- benzodioxin-8-yl)methyl]thio}-3- methyl phenyl)-2,2- dimethylpropanamide
440.0
50
N-{2-[(1,3-benzodioxol-5-ylmethyl) thio]-3-methylphenyl}-3-chloro-2,2- dimethylpropanamide
392.2
51
3-chloro-2,2-dimethyl-N-{3-methyl- 2-[(pyridin-2-ylmethyl)thio]phenyl} propanamide
349.2
52
N-{2-[(1,3-benzodioxol-5-ylmethyl) thio]-3-methylphenyl}-2,2-dimethyl propanamide
358.2
EXAMPLE 53
N-{2-[(5-amino-2-methoxybenzyl)thio]phenyl}-2,2-dimethylpropanamide hydrochloride
The product of Example 11 dissolved in ethanol and treated with 4 equivalents of Tin(II) dichloride dihydrate at reflux for 4 h. The reaction was cooled, diluted with water, made basic with potassium hydroxide and extracted with ethyl acetate (3×250 mL). The combined organics were washed with water then saturated sodium chloride solution. The solvent was removed in vacuo and the residue dissolved in diethyl ether. 4 N HCl in dioxane was added in excess and the resulting precipitate was filtered by suction to afford the product. 345.2 M+1
EXAMPLES 54-57
The product of Example 53 was combined with an excess of the appropriate aldehyde or ketone in methanol. A solution of sodium cyanoborohydride in methanol was added in and the pH was corrected to 5 with acetic acid. The reaction was agitated for 4 d then PS-TsNHNH2 resin was added and the reaction agitated a further 3 hours. The reactions were filtered and the filtrate was dried to a residue which was chromatographed on silica to afford the product.
Example
Mass
Number
Structure
Compound Name(s)
Spec
54
N-{2-[(5-{[3-fluoro- 4-(trifluoromethyl)benzyl] amino}-2-methoxybenzyl) thio]phenyl}-2,2-dimethyl propanamide
521.2
55
N-[2-({2-methoxy-5-[(3- methoxy-2-nitrobenzyl) amino]benzyl}thio)pheny] -2,2- dimethyl propanamide
510.2
56
N-{2-[(2-methoxy-5-{[(7- methoxy-1,3-benzodioxol-5-yl) methyl]amino}benzyl) thio]phenyl}-2,2-dimethyl propanamide
509.2
57
N-[2-({2-methoxy-5-[(4- methoxybenzyl)amino] benzyl}thio)phenyl]-2,2- dimethylpropanamide
465.2
EXAMPLES 58-60
The product of Example 53 was acylated by using excess of the appropriate acid chloride, PS-DMAP resin, PS-DIEA in dichloromethane and agitating the reaction overnight at room temperature. PS-Trisamine was added in and the reaction agitated a further 18 h. The reaction was filtered and the filtrate was reduced under a stream of nitrogen to afford the product.
Example
Mass
No
Structure
Compound Name(s)
Spec
58
N-{3-[({2-[(2,2-dimethyl propanoyl)amino]phenyl}thio) methyl]-4-methoxyphenyl} cyclobutanecarboxamide
427.2
59
N-{3-[({2-[(2,2-dimethyl propanoyl)amino]phenyl}thio) methyl]-4-methoxyphenyl}cyclo propanecarboxamide
413.2
60
N-{3-[({2-[(2,2-dimethyl propanoyl)amino]phenyl}thio) methyl]-4-methoxyphenyl} pentanamide
429.2
EXAMPLE 61
LXR Reporter Gene Transactivation Assay for High-Throughput Screen
Human hepatic cells (Huh-7) were cotransfected with a luciferase reporter gene (pGal4-RE), where transcription of luciferase gene is driven by the Gal4 response element, and a chimeric gene construct of liver X receptor (Gal4 DBD -LXRα LBD ), which comprises a DNA sequence that encodes a hybrid protein of LXR ligand binding domain (LXR LBD ) and Gal4 DNA-binding domain (Gal4 DBD ). The transfection was performed in culture dishes using LipofectAMINE2000 reagent. The transfected cells were harvested 20 hr later and resuspended in assay medium containing RPMI 1640 medium, 2% fetal bovine lipoprotein deficient serum, 100 units/ml pencillin and 100 μg/ml streptomycin.
In screening for LXR modulators, the transfected cells were dispensed in an assay plate (384-well white tissue culture plate) containing the test compounds at 10 μM final concentration and incubated for 24 hr. The effects of test compounds on the activation of LXR LBD and hence luciferase transcription was determined by measuring the luciferase activity using Steady-Glo luciferase assay substrate. Luciferase activity results are expressed as the fold-induction relative to DMSO controls. Compounds that exhibited >10 fold induction were then retested and the EC 50 was determined as the concentration necessary to produce 50% of the maximal luciferase activity. Each of the compounds of Examples 1-60 was found to have an EC 50 of less than 50 μM.
|
The present invention is directed to selective LXR modulators, small molecule compounds corresponding to Formula I and is further directed to a process of treating a condition in a mammal that is modulated by LXR using a therapeutically effective dose of a compound of Formula I.
| 2
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a case nitrided product, a process for producing a case nitrided product, and a nitriding agent used for nitriding an aluminum product.
2. Description of the Related Art
Aluminum products have been well known that they exhibit a hardness smaller than that of steel or the like. When they are slid on the steel of the like, they are extremely likely to be seized and worn out. Therefore, they have been investigated for their applicability to a variety of surface treatments which utilize, fop example, plating, thermal spraying, anode oxidizing and the like. Some of the treatments have been put into actual applications. Most of these treatments form an oxide layer on the surface of the aluminum products. There were a few try-outs by nitriding, however, the resulting nitriding layers formed on the surface of the aluminum products were so thin that no satisfactory case nitrided aluminum products have been available so far. Since these trial nitriding processes have required expensive equipment capable of producing a high degree of vacuum or the like, none of the processes have been put into actual application.
As recited in Japanese Unexamined Patent Publication (KOKAI) No. 60-211,061, there has been reported recently a process for forming a nitriding layer on the surface of the aluminum products. According to the process, prior to nitriding step, a pre-sputtering step is carried out in an argon gas atmosphere which contains a nitrogen or oxygen gas in a trace amount, and then a nitriding step is carried out by ion nitriding in which glow discharge is effected in a nitrogen gas atmosphere. Further, as set forth in Japanese Unexamined Patent Publication (KOKAI) No. 63-290,255, there is disclosed a surface treatment process for an aluminum product which utilizes a nitrogen ion injection. Furthermore, in Japanese Unexamined Patent Publication (KOKAI) No. 62-153,107 and Japanese Unexamined Patent Publication (KOKAI) No. 62-278,202, as a direct nitriding process for aluminum, there are disclosed examples of directly nitriding granular aluminum, however, there are no descriptions that the nitriding can be used as a surface treatment.
Aluminum has a melting point of 650° C. The melting point is lower by a factor of about 1/3 than that of steel (e.g., about 1,600° C.). Accordingly, during the surface treatments which are carried out below the melting point either by means of aluminum oxide layer formation or aluminum nitride formation, it has been regarded inevitable that the film forming rate is extremely slow. Further, aluminum is very active and is likely to be oxidized. Consequently, on the surface of aluminum, there always exists a natural oxide layer slightly occupying a part of the area thereof. The oxide layer inhibits the nitriding layer from forming. Furthermore, even if the oxide layer can be removed by sputtering or the like prior to surface treatment, aluminum is oxidized preferentially in commercially available apparatuses which produce a vacuum on the order of 10 -5 Tort vacuum degree. Hence, it has been said that aluminum is hardly nitrided.
SUMMARY OF THE INVENTION
The present invention has been developed in view of the circumstances described above. It is therefore an object of the present invention to provide a case nitrided product which is formed without employing the pre-sputtering, which is formed not by the vacuum apparatus capable of producing the high degree of vacuum but by an ordinary nitriding furnace, and which has a deep and high-hardness nitriding layer formed on the surface. It is a further object of the present invention to provide a nitriding process and a nitriding agent which are capable of producing the case nitrided product.
The present invention is based on a discovery that, when the surface of an aluminum product was covered with an aluminum powder and a heat treatment was carried out onto the aluminum product covered with the aluminum powder in a nitrogen gas atmosphere, a relatively thick nitriding layer was formed on the surface portion of the aluminum product. This discovery was a clue, and it led to a variety of experiments and examinations for completing the present invention.
A case nitrided aluminum product according to the present invention comprises a nitriding layer formed by direct nitriding in which a nitrogen gas is acted onto a surface thereof. The nitriding layer has a depth of 5 micrometers or more, and it exhibits a case hardness of from 250 to 1,200 micro Vickers hardness (hereinafter simply referred to as "mHv"). Preferably, it exhibits a case hardness of from 400 to 800 mHv. The term "aluminum" means aluminum and aluminum alloys. The term "powder" means atomized powder, flake powder, and so on.
The nitriding layer of the present case nitrided aluminum product is formed of a mixed phase including aluminum nitride and aluminum. The aluminum nitride is formed as a needle-like configuration which has an extremely fine diameter of from 5 to 50 nm. When the aluminum nitride is included more therein, the nitriding layer exhibits a higher Vickers hardness. In the nitriding layer, there can exist magnesium oxide in an amount of 0.5% by weight or more. It is considered that the magnesium oxide results from the aluminum oxide which was present on the surface of the aluminum product as the natural oxide layer and which was reduced by magnesium included in a nitriding agent, it can exist in the nitriding layer in the aforementioned amount.
The nitriding layer may include nitrogen in an amount of from 5 to 30% by weight at maximum. This maximum nitrogen content defines the nitriding rate in the nitriding layer. When the maximum nitrogen content is less than 5% by weight, the nitriding layer exhibits a low hardness and is poor in strength. When transforming aluminum into aluminum nitride, the transformation causes expansion by a factor of 26% as compared to the aluminum itself, and the resulting nitriding layers exhibit a thermal expansion coefficient decreased to 1/4 or less of the aluminum itself. Hence, when the maximum nitrogen content is more than 30% by weight, the resulting nitriding layers are very brittle unpreferably and they are likely to undesirably come off from the mother material.
When the nitriding layer has a depth of 5 micrometers or more, it is possible to fulfill the purposes of the nitriding layer presence. However, in view of the strength and coming-off resistance, it is preferred that the nitriding layer has a depth of 20 micrometers or more.
The nitriding layer can be formed on all over the surface of the aluminum product, or it can be formed partially on a particular surface thereof. The aluminum product can be an aluminum blank of a plate shape, a rod shape or the like, and it can be formed into a predetermined configuration in advance.
The present case nitrided aluminum product can be produced by a process for producing a case nitrided aluminum product according to the present invention. The present process comprises the steps of:
contacting an aluminum product with a nitriding agent at a part of a surface thereof at least, the nitriding agent including an aluminum powder; and
nitriding the aluminum product at the surface with an ambient gas at a temperature of a melting point of the aluminum product or less while keeping the aforementioned contact, the ambient gas virtually including a nitrogen gas.
It has not been clear still what principle governs the present process. However, when nitriding is carried out while flowing a nitrogen gas, there is formed a nitriding layer not only on the portions which ape coated with the aluminum powder working as a nitriding agent but also on the portions which are disposed slightly downstream in the nitrogen gas flow with respect to the coated portions. Hence, it is assumed that nascent nitrogens contribute to the nitriding. For instance, it is believed that, when the aluminum powder is used as the nitriding agent and it is brought into contact with the nitrogen gas at a predetermined temperature, the aluminum powder itself is nitrided, and simultaneously a part of the nitrogen gas is excited to produce the nascent nitrogens. It is thus presumed that the nascent nitrogens are absorbed by the aluminum product to thereby form a nitriding layer.
Concretely described, it is assumed that the nascent nitrogens reduces aluminum oxide on the surface of the aluminum product to be nitrided. As a result, the surface of the aluminum product comes to be pure aluminum, and it becomes easy to be nitrided. In a coating layer of an aluminum powder coated on the surface of the aluminum product, the following reaction occurs:
Al (powder)+N.sub.2 =Al N+N;
and aluminum oxide on the surface of the aluminum product is reduced as shown in the following chemical equations:
(1/5) Al.sub.2 O.sub.3 +N=(2/5)Al N+(3/5 ) NO.
The surface of the aluminum product is purified so that it becomes easy to be nitrided. After the surface of the aluminum product is purified, it is assumed that nitrogen is easily absorbed from the surface of the aluminum product, and that a thick nitriding layer is formed.
The aluminum powder employed in the present nitriding process can be used as the present nitriding agent as far as it can be nitrided. However, it is preferable to employ an aluminum powder having a high nitriding capability. Such an aluminum can be one which is quenched and solidified, particularly, it can be one which is quenched and solidified at a cooling rate of 10 2 °C./sec. or more, preferably at a cooling rate of from 10 2 to 10 5 ° C./sec. Further, an aluminum powder which is made from an aluminum alloy including magnesium works very well as the nitriding agent. It is especially preferable to select an aluminum powder including magnesium in an amount of 0.5% by weight or more, further preferably in an amount of from 1 to 20% by weight.
The aluminum powder can be used as the nitriding agent not only in the powdered form which is attained, for example, by atomizing, but also in a foiled form, a granulated form or the like. The foil-formed aluminum powder and the granule-formed aluminum powder can be mixed and used together. In other words, it can be formed by pulverizing foils, ribbons, machined wastes or the like by means of stamping, ball-milling or the like.
For instance, the foil-formed (i.e., flake-like) aluminum powder can be prepared by using a ball mill, an attritor, or the like. If such is the case, it is usually possible to employ higher aliphatic acid, such as oleic acid, stearic acid, isosteraric acid, lauric acid, palmitic acid, myristic acid and the like, for a pulverizing-aiding agent. In addition to the higher aliphatic acid, it is also possible to employ aliphatic amine, aliphatic amide, aliphatic alcohol and the like therefor.
As for an average particle diameter of the aluminum powder operating as the nitriding agent, it is preferred that the aluminum nitride has an average particle diameter of from 3 to 200 micrometers. The aluminum powder can be in a granulated form, a foiled form, or mixtures of these two forms. In view of the reactivity, it is preferred that the aluminum powder has a specific surface area of from 0.1 to 15 m 2 /g, and it is especially preferred that it has a specific surface area of from 0.4 to 1.0 m 2 /g. The average particle diameter is measured by using "LASER PARTICLE ANALYZER." The specific surface area is calculated with the BET equation.
Magnesium is a metal which has high affinity with oxygen. It is believed that magnesium diffuses on the aluminum product surface to contribute to the following reaction:
Al.sub.2 O.sub.3 +3Mg+N.sub.2 =2Al N+3MgO
The aluminum product to be nitrided can be made either from pure aluminum or aluminum alloys. However, in the aluminum product, depending on the elements excepting the aluminum elements, a variety of nitriding layers can be formed. Magnesium present in the aluminum product functions to thicken the resulting nitriding layers. On the contrary, silicon does not function to thicken the resulting nitriding layers, but it inhibits them from thickening. It is assumed that the other elements usually included in the aluminum product somewhat affect the thickening of the resulting nitriding layers. However, their functions are not verified at present.
The nitriding agent can be a mixture of the aluminum powder and a viscosifying agent. If such is the case, it is preferred that the nitriding agent includes the aluminum powder in an amount of from 5 to 70% by weight and the viscosifying agent in an amount of from 1 to 30% by weight. Since this nitriding agent is used to coat a surface of the aluminum product to be nitrided, it is possible to further mix an additive, such as a solvent or the like, which is usually employed by paint in order to give the paint an appropriate flowing ability. As for the solvent, it is preferable to employ an organic substance which decomposes or vaporizes at a nitriding reaction temperature or less. In addition, when an organic substance produces residual products which are harmless to the nitriding reaction, it is possible to employ such an organic substance as the solvent.
As for the viscosifying agent, it is possible to employ an organic polymer compound, such as polybutene, polyvinyl butyral, polycaprolactone and the like, which decomposes at the nitriding temperature, e.g., usually at a temperature of from 400° to 600° C. It is preferable that the viscosifying agent decomposes during a nitriding treatment. When the viscosifying agent decomposes, an aluminum powder usually cannot be scattered and can be held on the surface of the aluminum product under the condition that a part of the aluminum powder is sintered.
The aluminum product surface and the aluminum powder can be brought into contact with each other by burying the aluminum product in the aluminum powder, or by coating the aluminum product surface with the aluminum powder. In addition, the aluminum product surface can be coated with the above-described paste-like or paint-like nitriding agent. When coating, it is preferred that the nitriding agent is coated as a paint film of from 5 to 1,000 micrometers in thickness. As for the way of coating, it is possible to employ brush-coating, dipping, spray-coating, roller-coating or the like.
Regarding the ambient gas for carrying out the nitriding, a nitrogen gas can be used. It is preferred that the nitrogen gas has less water and oxygen gas contents. The mingling of the inert gas such as an argon gas or the like does not adversely affect the nitriding. Concerning the water content and the oxygen gas content, it is preferred that the nitrogen gas includes water in an amount of 0.1% by volume or less as water vapor and oxygen in an amount of 0.08% by volume or less.
Regarding the nitriding temperature, it is preferred that, in view of the reactivity, the nitriding is carried out at temperatures as high as possible. However, it is necessary that the aluminum product be treated virtually in the solid-phase state. When a deep nitriding layer is not desired, or when the strain resulting from the heat treatment should be reduced, it is preferred that the nitriding is carried out at low temperatures. In view of these requirements, it is usually preferred to carry out the nitriding at a temperature of about 400° to 600° C. for about 2 to 10 hours.
In the present nitriding process, the aluminum product is coated with the nitriding agent which is likely to be nitrided, and it is nitrided in the solid-phase state in the nitrogen atmosphere. First of all, the magnesium included in the nitriding agent reacts with the oxygen of the aluminum oxide included in the nitriding agent. Then, the nitriding agent which is likely to be nitrided is nitrided, thereby producing a formation energy of 300 kJ/mole and the nascent nitrogens. The aluminum product is activated and nitrided by the formation energy and the nascent nitrogens where it is brought into contact with the nitriding agent. Thus, it is possible to form a deep nitriding layer with ease under the conditions where it has been said to be too difficult to carry out nitriding. Therefore, it is possible to easily produce a case nitrided aluminum product whose nitriding layer is enhanced in terms of hardness.
As for the nitriding agent, it is possible to employ an aluminum powder which includes aluminum as a major component. When the nitriding agent is used to partially coat the aluminum product surface or when it is used to partially bury the aluminum product, it enables to nitride the coated or buried portion only. Thus, it is possible to nitride a predetermined portion of the aluminum product only.
In accordance with the present nitriding process using the present nitriding agent, it is possible to produce the present case nitrided aluminum product which comprises the nitriding layer having the depth of 5 micrometers or more and exhibiting the case hardness of from 250 to 1,200 mHv.
As having been described so far, the present case nitrided aluminum product comprises the remarkably deep and hard case nitriding layer. The nitriding layer is formed by heat treating the aluminum product surface by means of the nitrogen gas while the present nitriding agent comprising the aluminum powder is brought into contact with the aluminum product surface. Therefore, the present case nitrided aluminum product can be appropriately applied to sliding parts which require high wear resistance.
In accordance with the present process, the aluminum product can be nitrided with ease where it is brought into contact with the present nitriding agent. On the other hand, it is not nitrided where it is not brought into contact with the present nitriding agent. By utilizing these phenomena, it is possible to only nitride a predetermined portion of the aluminum product where the nitriding is required.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the present invention and many of its advantages 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 and detailed specification, all of which forms a part of the disclosure:
FIG. 1 is a microscope photograph for showing a metallic structure of a case nitrided aluminum product with a nitriding layer formed in accordance with a First Preferred Embodiment of the present invention in cross-section;
FIG. 2 is a chart for illustrating results of an EPMA (i.e., Electron Probe Microanalysis) to which the case nitrided aluminum product with a nitriding layer formed in accordance with the First Preferred Embodiment was subjected;
FIG. 3 is a microscope photograph for showing a metallic structure of a case nitrided aluminum product which was nitrided for 4 hours in accordance with a Second Preferred Embodiment of the present invention;
FIG. 4 is a microscope photograph for showing a metallic structure of another case nitrided aluminum product which was nitrided for 10 hours in accordance with the Second Preferred Embodiment;
FIG. 5 is a chart for illustrating results of an EPMA to which the case nitrided aluminum product undergone the 10-hour nitriding in accordance with the Second Preferred Embodiment was subjected;
FIG. 6 is a chart for illustrating results of an EPMA in which the case nitrided aluminum product undergone the 10-hour nitriding in accordance with the Second Preferred Embodiment was examined for its oxygen content instead of its nitrogen content illustrated in FIG. 5;
FIG. 7 is a microscope photograph for showing a metallic structure of a case nitrided aluminum product with a nitriding layer formed in accordance with a Third Preferred Embodiment of the present invention in cross-section;
FIG. 8 is a chart for illustrating results of an X-ray diffraction analysis to which the nitriding layer of the case nitrided aluminum product formed in accordance with the Third Preferred Embodiment was subjected;
FIG. 9 a microscope photograph for showing a metallic structure of a case nitrided aluminum product with a nitriding layer formed in accordance with a Fourth Preferred Embodiment of the present invention in cross-section; and
FIG. 10 is a microscope photograph for showing a metallic structure of a case nitrided aluminum product with a nitriding layer formed in accordance with a Fifth Preferred Embodiment of the present invention in cross-section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Having generally described the present invention, a further understanding can be obtained by reference to the specific preferred embodiments which are provided herein for purposes of illustration only and are not intended to limit the scope of the appended claims.
First Preferred Embodiment
An aluminum alloy having the composition as per JIS (Japanese Industrial Standard) 5052 was melted. The aluminum alloy included Mg in an amount of from 2.2 to 2.8% by weight, Si and Fe in a summed amount of 0.65% by weight or less, Cu in an amount of 0.10% by weight or less, Mn in an amount of 0.10% by weight or less, Zn in an amount of 0.10% by weight or less, Cr in an amount of from 0.15 to 0.35% by weight, and the balance of Al. The resulting molten metal was quenched and solidified by air-atomizing at a cooling rate of 10 2 ° C./sec. or more, and it was formed into a powdered form having an average particle diameter of from 5 to 200 micrometers.
The resulting aluminum powder was employed as the present nitriding agent, and a pure aluminum plate was employed as the aluminum product to be nitrided. The plate was made from a pure aluminum as per JIS 1100 and had a thickness of 1.0 mm. The aluminum product to be nitrided was buried in the nitriding agent. Then, it was subjected to a nitriding treatment at 540° C. for 10 hours. The nitriding treatment was carried out under the following conditions: A pure nitrogen gas containing 99.9% N 2 was introduced into an furnace at a flow of 20 liters/min., and a dew point was held in a range of from -39 to -28° C. in the furnace.
This nitriding treatment produced a nitriding layer on all over the aluminum product surface. In order to examine the resulting nitriding layer, the thus nitrided aluminum product was cut at its end, and it was observed with a microscope for its metallic structure in the cross-section. A microscope photograph thus obtained is shown in FIG. 1. Further, the cross-section of the aluminum product was subjected to an EPMA in order to examine the nitriding layer for its composition by its elements, and the resulting EPMA chart is shown in FIG. 2.
As can be seen from FIG. 1, the depth of the nitriding layer fluctuated, however, it fell in a range of from 70 to 220 micrometers. The hardness of the nitriding layer was 800 mHv under a load of 100 g.
As can be understood from FIG. 2 illustrating the results of the elementary analysis, the nitriding layer was found to be comprised of aluminum, nitrogen and magnesium. In FIG. 2, the axis of ordinate expresses the weight percentages of aluminum, magnesium and nitrogen. For example, the values at the uppermost point in the axis of ordinate, e.g., 100.000, 10.000 and 40.000, mean 100% by weight aluminum, 10% by weight magnesium and 40% by weight nitrogen, respectively. The axis of abscissa expresses the depth from the surface. For instance, the right end of the axis of abscissa means the outermost surface, and the nitriding layer becomes deeper as the value goes along the axis of abscissa in the left direction. According to FIG. 2, the nitriding layer had a depth of about 300 micrometers at the analyzed cut end. At this end, the nitriding layer was comprised of aluminum in an amount of about 65% by weight, magnesium in an amount of about 2.5% by weight and nitrogen in an amount of about 20% by weight, and its maximum nitrogen content was 20.90% by weight. The nitrogen content was substantially constant over the entire nitriding layer. On the other hand, the magnesium content was high adjacent to the outermost surface of the nitriding layer, but it decreased gradually as the nitriding layer was formed deeper. However, the magnesium content in the nitriding layer was much higher than the magnesium content in the matrix of the aluminum product. The magnesium in the nitriding layer resulted from the magnesium which diffused from the nitriding agent to the nitriding layer.
Second Preferred Embodiment
In the same manner as set forth in the First Preferred Embodiment, the aluminum alloy powder having the composition as per JIS 5052 was made by quenching and solidifying and employed as the present nitriding agent. As an aluminum product, an aluminum alloy plate having a thickness of 1.50 mm was made from an aluminum alloy. The aluminum alloy had the composition as per JIS 5052. The aluminum alloy plate was also buried in the nitriding agent. Then, it was subjected to two kinds of nitriding treatments, for instance, at 540° C. for 4 hours and at 540° C. for 10 hours. In both of the nitriding treatments, a pure nitrogen gas containing 99.9% N 2 was introduced into an furnace at a flow of 30 liters/min. as the nitriding gas, and a dew point was held in a range of from -40° to -25° C. in the furnace.
These two nitriding treatments produced a thick nitriding layer on the surface of the aluminum product. The resulting nitriding layers were similarly observed with a microscope for their metallic structure. FIG. 3 shows a microscope photograph of the case nitrided aluminum product which went through the 4-hour nitriding. FIG. 4 shows a microscope photograph of the case nitrided aluminum product which went through the 10-hour nitriding. In FIGS. 3 and 4, the portion on the right-hand side in the photograph is a metallic structure of the aluminum product matrix, and the gray portion at the middle in the photograph is a metallic structure of the nitriding layer. In the case nitrided aluminum product shown in FIG. 3 which went through the 4-hour nitriding, the nitriding layer had a depth of about 14 micrometers, and it exhibited a hardness of 515 mHv under a load of 100 g. In the case nitrided aluminum product shown in FIG. 4 which went through the 10-hour nitriding, the nitriding layer had a depth of about 130 micrometers, and it exhibited a hardness of 420 mHv under a load of 100 g.
In addition, an elementary analysis was carried out onto the portions of the aluminum product shown in FIG. 4 along the arrow thereof by means of the EPMA. FIGS. 5 and 6 illustrate the results of the elementary analysis. In FIG. 5, similarly to FIG. 2, the axis of ordinate expresses the weight percentages of aluminum, magnesium and nitrogen, and the axis of abscissa expresses the depth from the surface. In FIG. 5, contrary to FIG. 2, the left end of the axis of abscissa means the outermost surface, and the elementary analysis is performed deep inside the aluminum product as the value goes along the axis of abscissa in the right direction. According to FIG. 5, the surface of the case nitrided aluminum product lay at a depth of 20 micrometers, the nitriding agent layer lay in a depth of from 0 to 20 micrometers, the nitriding layer lay in a depth of from 20 to 150 micrometers, and the aluminum matrix of the case nitrided aluminum product lay in a depth of more than 150 micrometers. FIG. 6 illustrates the results of the elementary analysis in which, instead of the nitrogen content illustrated in FIG. 5, the portions of the aluminum product shown in FIG. 4 were examined for the oxygen content along the arrow of FIG. 4.
According to the results of these elementary analyses, the nitriding layer was comprised of nitrogen in an amount of 13.1% by weight in its middle and in an amount of 8.33% by weight at the interface between itself and the aluminum matrix or the aluminum product. It is characteristic in the chart shown in FIGS. 5 and 6 that the magnesium content exhibited a peak at the outermost surface of the case nitrided aluminum product (e.g., the interface between the nitriding agent and the nitriding layer), and that the oxygen content exhibited peaks at the outermost surface and the innermost surface of the nitriding layer. According to the results of the elementary analysis on the oxygen content shown in FIG. 6, the oxygen content was as high as 1.3% by weight at the outermost surface of the nitriding layer. Accordingly, it is believed that there existed oxygen and magnesium in the form of MgO in an amount of 3.3% by weight. Thus, the present inventors came to assume as follows. The oxygen is originally included in the aluminum oxide layer which exists on the outermost surface of the aluminum product, it is then reacted with the magnesium which is moved from the inside of the aluminum product or from the nitriding agent by means of diffusion, and consequently the magnesium oxide is produced.
Third Preferred Embodiment
Two molten aluminums including magnesium in an amount of 2.5% by weight and 5% by weight respectively were quenched and solidified at a cooling rate of 10 2 ° C./sec. or more. Thus, two aluminum powders were prepared, and they had an average particle diameter of from 3 to 150 micrometers. These two aluminum powders were employed as the present nitriding agent. Further, these two powders were pulverized to foiled-shapes by a ball mill to produce two foil-shaped aluminum powders having a specific surface area of 4 m 2 /g. These two foil-shaped aluminum powders were also employed as the present nitriding agent. Thus, four nitriding agents according to the present invention were prepared in total.
These four nitriding agents were respectively compounded with polybutene so that they could form a paste-like substance capable of being coated with a brush. The resulting four paste-like nitriding agents were used to coat a variety of aluminum plates and aluminum automotive component parts which were prepared as the aluminum product to be nitrided, and they were coated with a brush so as to form a coating layer of about 10 micrometers in thickness on the aluminum products. Whilst there was prepared a heat treatment furnace whose inner atmosphere was replaced by a nitrogen gas in advance, the aluminum products coated with the four nitriding agents were put into the furnace. Then, the temperature of the furnace was raised in order to carry out a nitriding treatment at 450° C. for 4 hours. In addition, another aluminum products similarly coated with the four nitriding agents were put into the furnace, and they were nitrided at 450° C. for 10 hours. In both of the nitriding treatments, a pure nitrogen gas containing 99.9% N 2 was introduced into the furnace at a flow of 10 liters/min., and a dew point was held in a range of From -45° to -25° C. in the furnace.
There was produced a thick nitriding layer on the portion of all of the aluminum products where the nitriding agents were coated. For example, FIG. 7 shows an enlarged cross-sectional photograph of the metallic structure of one of the nitriding layers formed on one of the aluminum products, e.g., the aluminum plate, which was made from an aluminum alloy having the composition as per JIS 2024 and which was coated with the paste-like nitriding agent including magnesium in an amount of 5% by weight. The aluminum alloy as per JIS 2024 was comprised of Mg in an amount of from 1.2 to 1.8% by weight, Si in an amount of 0.5% by weight or less, Fe in an amount of 0.5% by weight or less, Cu in an amount of from 3.8 to 4.9% by weight, Mn in an amount of from 0.30 to 0.9% by weight, Zn in an amount of 0.25% by weight or less, Cr in an amount of 0.10% by weight or less, and the balance of Al.
As can be appreciated from FIG. 7, there was formed the blackish gray nitriding layer having a depth of about 35 micrometers on the aluminum product. In FIG. 7, squares can be seen on the left side of the drawing, and they were dents which were made by pressing during the Vickers hardness measurement. The hardness of the nitriding layer was 440 mHv under a load of 100 g. In addition, FIG. 8 is a chart for illustrating the results of an X-ray diffraction analysis to which this nitriding layer was subjected. According to FIG. 8, this nitriding layer was found to be comprised of a mixed phase including aluminum and aluminum nitride.
Fourth Preferred Embodiment
In the same manner as set forth in the First Preferred Embodiment, an aluminum alloy powder having a composition of 2.5% by weight of Mg and the balance of Al was made by quenching and solidifying, and it was employed as the present nitriding agent. In the resulting aluminum alloy powder, there was buried an aluminum product having a thickness of 5 mm and the composition as per JIS AC4C. Then, it was subjected to a nitriding treatment at 560° C. for 10 hours. In the nitriding treatment, a pure nitrogen gas containing 99.9% N 2 was introduced into an furnace at a flow of 30 liters/min., and a dew point was held in a range of from -40° to -25° C. in the furnace.
This nitriding treatment produced a nitriding layer having a depth of about 5 micrometers on all over the surface of the aluminum product. FIG. 9 shows a microscope photograph of the metallic structure of the resulting nitriding layer. In FIG. 9, the aluminum product is the white portion disposed on the lower side of the drawing, the nitriding layer is the light blackish portion disposed on the white portion, and the space is the black portion disposed further on the light blackish portion.
Fifth Preferred Embodiment
A pure molten aluminum including aluminum in an amount of 99.3% by weight was quenched and solidified at a cooling rate of 10 2 ° C./sec. or more. Thus, an aluminum powder was prepared, and it had an average particle diameter of from 3 to 150 micrometers. Further, this aluminum powder was pulverized to foiled-shapes by a ball mill to produce a foil-shaped aluminum powder having a specific surface area of 5 m 2 /g. The foil-shaped aluminum powder was employed as the present nitriding agent, and it was compounded with polybutene so that it could form a paste-like substance capable of being coated with a brush.
An aluminum plate having the composition as per JIS 2024 was employed as the aluminum product to be nitrided. The nitriding agent was coated on the aluminum product with a brush so as to form a coating layer of about 20 micrometers in thickness. The thus treated specimens were put into an furnace whose inner atmosphere had been replaced by a nitrogen gas in advance. Then, the temperature of the furnace was raised in order to carry out a nitriding treatment at 540° C. for 10 hours. In the nitriding treatment, a pure nitrogen gas containing 99.9% N 2 was introduced into the furnace at a flow of 10 liters/min., and a dew point was held in a range of from -30° to -20° C. in the furnace.
There was produced a thick nitriding layer on all over the surface of the aluminum plate. FIG. 10 shows an enlarged cross-sectional photograph of the metallic structure of the resulting nitriding layer. As can be appreciated from FIG. 10, there was formed the blackish gray nitriding layer having a depth of about 350 micrometers on the aluminum product. According to the Vickers hardness measurement, the hardness of the nitriding layer was 274 mHv under a load of 100 g.
Sixth Preferred Embodiment
A molten aluminum alloy including magnesium in an amount of 5% by weight was quenched and solidified at a cooling rate of 10 2 ° C./sec. or more, thereby producing an atomized powder of an average particle diameter of from 3 to 150 micrometers.
130 grams of the atomized powder was weighed in a beaker having a capacity of 1 liter. 20 grams of a polybutene resin and 30 grams of a solvent were added to the beaker. The polybutene resin was "POLYBUTENE OH" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and it had a weight average molecular weight of 350 and a viscosity of 22 cSt at 40° C. The solvent was "IP SOLVENT 1620" made by IDEMITSU SEKIYU KAGAKU Co., Ltd. The resulting mixture was stirred at a rate of 1,000 rpm, thereby dispersing the aluminum powder in the resin and the solvent. Thereafter, 20 grams of another polybutene was further added to the beaker gradually while stirring at a rate of 3,000 rpm for 1 hour, thereby producing a paste-like nitriding agent in which the aluminum powder was dispresed uniformly in the resins and the solvent. The other polybutene resin was "POLYBUTENE 300H" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and it had a weight average molecular weight of 1,500 and a viscosity of 32,000 cSt at 40° C.
Whilst an aluminum product to be nitrided was prepared, a pure aluminum according to JIS 1101 was employed and was processed into a plate having a thickness of 1.0 mm. On the aluminum product, the paste-like nitriding agent was coated.
The thus coated aluminum product was placed in a heat treatment furnace, and it was nitrided at 550° C. for 5 hours under the following conditions: A pure nitrogen gas containing 99.9% N 2 was introduced into the furnace at a flow of 20 liters/min., and a dew point was held in a range of from -39° to -28° C. in the furnace.
There was produced a nitriding layer all over the surface of the aluminum product. The nitriding layer had a depth of about 120 micrometers, and it exhibited a hardness of 600 mHv under a load of 100 g.
Seventh Preferred Embodiment
80% by weight of the atomized powder, produced in the same manner as described in the "Sixth Preferred Embodiment" section, was mixed with 20% by weight of oleic acid working as a pulverizing-aiding agent, and it was further pulverized with a ball mill, thereby preparing a flake-formed (or foil-formed) aluminum powder. The foil-formed aluminum powder had a specific surface area of 2.9 m 2 /g and an average particle diameter of 36 micrometers.
60 grams of the foil-formed aluminum powder containing oleic acid was weighed in a beaker having a capacity of 1 liter. 8 grams of a polybutene resin and 40 grams of a solvent were added to the beaker. The polybutene resin was "POLYBUTENE OH" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and the solvent was "IP SOLVENT 1620" made by IDEMITSU SEKIYU KAGAKU Co., Ltd. The resulting mixture was stirred at a rate of 1,000 rpm, thereby dispersing the aluminum powder in the resin and the solvent. Thereafter, 8 grams of another polybutene and 69 grams of another solvent were further added to the beaker while stirring at a rate of 1,000 rpm for 1 hour, thereby producing a nitriding agent. The other polybutene resin was "POLYBUTENE 300H" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and the other solvent was "BDG" (i.e., polydiglcol) made by NIPPON NYUKAZAI Co., Ltd.
Whilst an aluminum product to be nitrided was prepared, an aluminum alloy according to JIS 2024 was employed and was processed into a plate having a thickness of 1.5 mm. On the aluminum product, the paste-like nitriding agent was coated.
The thus coated aluminum product was placed in a heat treatment furnace, and it was subjected to a nitriding treatment at 500° C. for 10 hours under the following conditions: A pure nitrogen gas containing 99.9% N 2 was introduced into the furnace at a flow of 30 liters/min., and a dew point was held in a range of from -40° to -25° C. in the furnace.
There was produced a nitriding layer on the surface of the aluminum products. The nitriding layer had a depth of about 70 micrometers, and it exhibited a hardness of 500 mHv under a load of 100 g.
Eighth Preferred Embodiment
An aluminum flake was weighed so as to place 60 grams of its metallic components in a beaker having a capacity of 1 liter. The aluminum flake was "ALUMINUM PASTE 7675NS" made by TOYO ALUMINIUM Co., Ltd., and it had an average particle diameter D 50 of 14 micrometers, a specific surface area of 5.3 m 2 /g and 65% by weight nonvolatile components. 8 grams of a polybutene resin and 40 grams of a solvent were added to the beaker. The polybutene resin was "POLYBUTENE OH" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and the solvent was "IP SOLVENT 1620" made by IDEMITSU SEKIYU KAGAKU Co., Ltd. The resulting mixture was stirred at a rate of, 1,000 rpm, thereby dispersing the aluminum powder in the resin and the solvent. Thereafter, 8 grams of another polybutene and 52 grams of another solvent were further added to the beaker while stirring at a rate of 1,000 rpm for 1 hour, thereby producing a nitriding agent. The other polybutene resin was "POLYBUTENE 300H" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and the other solvent was "BDG" (i.e., polydiglcol) made by NIPPON NYUKAZAI Co., Ltd.
Whilst an aluminum product to be nitrided was prepared, an aluminum alloy according to JIS 5052 was employed and was processed into a plate having a thickness of 1.5 mm. On the aluminum product, the paste-like nitriding agent was coated.
The thus coated aluminum product was placed in a heat treatment furnace, and it was subjected to a nitriding treatment at 580° C. for 5 hours under the following conditions: A pure nitrogen gas containing 99.9% N 2 was introduced into the furnace at a flow of 30 liters/min., and a dew point was held in a range of from -40° to -25° C. in the furnace.
There was produced a nitriding layer on the surface of the aluminum products. The nitriding layer had a depth of about 240 micrometers, and it exhibited a hardness of 580 mHv under a load of 100 g.
Ninth Preferred Embodiment
An aluminum flake was weighed so as to place 60 grams of its metallic components in a beaker having a capacity of 1 liter. The aluminum flake was "ALUMINUM PASTE 7620NS" made by TOYO ALUMINIUM Co., Ltd., and it had an average particle diameter D 50 of 18 micrometers, s specific surface area of 3.3 m 2 /g and 65% by weight nonvolatile components. 8 grams of a polybutene resin and 40 grams of a solvent were added to the beaker. The polybutene resin was "POLYBUTENE OH" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and the solvent was "IP SOLVENT 1620" made by IDEMITSU SEKIYU KAGAKU Co., Ltd. The resulting mixture was stirred at a rate of 1,000 rpm, thereby dispersing the aluminum powder in the resin and the solvent. Thereafter, 8 grams of another polybutene and 52 grams of another solvent were further added to the beaker while stirring at a rate of 1,000 rpm for 1 hour, thereby producing a paste-like nitriding agent. The other polybutene resin was "POLYBUTENE 300OH" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and the other solvent was "BDG" (i.e., polydiglcol) made by NIPPON NYUKAZAI Co., Ltd.
Whilst an aluminum product to be nitrided was prepared, an aluminum alloy according to JIS 5052 was employed and was processed into a plate having a thickness of 1.5 mm. On the aluminum product, the paste-like nitriding agent was coated.
The thus coated aluminum product was placed in a heat treatment furnace, and it was subjected to a nitriding treatment at 580° C. for 5 hours under the following conditions: A pure nitrogen gas containing 99.9% N 2 was introduced into the furnace at a flow of 30 liters/min., and a dew point was held in a range of from -40° to -25° C. in the furnace.
There was produced a nitriding layer on the surface of the aluminum products. The nitriding layer had a depth of about 220 micrometers, and it exhibited a hardness of 540 mHv under a load of 100 g.
Tenth Preferred Embodiment
An aluminum flake was weighed so as to place 60 grams of its metallic components in a beaker having a capacity of 1 liter. The aluminum flake was "ALUMINUM PASTE 46-046" made by TOYO ALUMINIUM Co., Ltd., and it had an average particle diameter D 50 of 37 micrometers, a specific surface area of 2.4 m 2 /g and 65% by weight nonvolatile components. 8 grams of a polybutene resin and 40 grams of a solvent were added to the beaker. The polybutene resin was "POLYBUTENE OH" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and the solvent was "IP SOLVENT 1620" made by IDEMITSU SEKIYU KAGAKU Co., Ltd. The resulting mixture was stirred at a rate of 1,000 rpm, thereby dispersing the aluminum powder in the resin and the solvent. Thereafter, 8 grams of another polybutene and 52 grams of another solvent were further added to the beaker while stirring at a rate of 1,000 rpm for 1 hour, thereby producing a paste-like nitriding agent. The other polybutene resin was "POLYBUTENE 300H" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and the other solvent was "BDG" (i.e., polydiglcol) made by NIPPON NYUKAZAI Co., Ltd.
Whilst an aluminum product to be nitrided was prepared, an aluminum alloy according to JIB 5052 was employed and was processed into a plate having a thickness of 1.5 mm. On the aluminum product, the paste-like nitriding agent was coated.
The thus coated aluminum product was placed in a heat treatment furnace, and it was subjected to a nitriding treatment at 580° C. for 5 hours under the following conditions: A pure nitrogen gas containing 99.9% N 2 was introduced into the furnace at a flow of 30 liters/min., and a dew point was held in a range of from -40° to -25° C. in the furnace.
There was produced a nitriding layer on the surface of the aluminum products. The nitriding layer had a depth of about 100 micrometers, and it exhibited a hardness of 680 mHv under a load of 100 g.
Eleventh Preferred Embodiment
130 grams of an atomized aluminum powder was weighed in a beaker having a capacity of 1 liter. The atomized aluminum powder was "AC5000" made by TOYO ALUMINIUM Co., Ltd., and it had an average particle diameter D 50 of 9 micrometers and a specific surface area of 0.8 m 2 /g. Then, 20 grams of a polybutene resin and 30 grams of a solvent were added to the beaker. The polybutene resin was "POLYBUTENE OH" made by IDEMITSU SEKIYU KAGAKU Co., Ltd., and the solvent was "IP SOLVENT 1620" made by IDEMITSU SEKIYU KAGAKU Co., Ltd. The resulting mixture was stirred at a rate of 1,000 rpm, thereby dispersing the aluminum powder in the resin and the solvent. Thereafter, 20 grams of another polybutene was further added to the beaker gradually while stirring at a rate of 3,000 rpm for 1 hour, thereby producing a nitriding agent. The other polybutene resin was "POLYBUTENE 300H" made by IDEMITSU SEKIYU KAGAKU Co., Ltd.
Whilst an aluminum product to be nitrided was prepared, a pure aluminum according to JIS 1101 was employed and was processed into a plate having a thickness of 1.0 mm. On the aluminum product, the paste-like nitriding agent was coated.
The thus coated aluminum product was nitrided in the same manner as described in the "Sixth Preferred Embodiment" section. As a result, there was produced a nitriding layer on the surface of the aluminum product. The nitriding layer had a depth of about 70 micrometers, and it exhibited a hardness of 750 mHv under a load of 100 g.
Having now fully described the present invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the present invention as set forth herein including the appended claims.
|
A case nitrided aluminum product is produced by contacting an aluminum product with a nitriding agent at a part of a surface thereof at least, and by nitriding the aluminum product at the surface with an ambient gas at a temperature of a melting point of the aluminum product or less while keeping the aforementioned contact. The nitriding agent includes an aluminum powder, and the ambient gas virtually includes a nitrogen gas. The resulting nitriding layer has a depth of 5 micrometers or more, and it exhibits a case hardness of from 250 to 1,200 mHv. Thus, it is possible to form the deep and hard nitriding layer on the aluminum product with ease under the conditions where it has been said to be too difficult to nitride aluminum products. The case nitrided aluminum product can appropriately make sliding parts which require high wear resistance.
| 2
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Reference is made to commonly assigned, co-pending U.S. patent application Ser. No. ______ by Westcott et al. (Docket 96531) filed of even date herewith titled “Forward Facing Scanner”, the disclosure of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] A document scanner is desired that has the ability to scan a variety of different document types and sizes. Further, the scanner is desired to have the ergonomic capabilities of a duplex C-transport sheet fed scanner to scan stacks of documents and the function of a flatbed scanner to scan irregular, thick or bound documents or other items. It is desired that these capabilities be combined into a single, forward-facing, compact desktop machine.
BACKGROUND OF THE INVENTION
[0003] Sheet fed scanners have become a popular computer peripheral for creating digital images from documents in both the home and the office. With respect to sheet fed scanners, an image forming subsystem, such as a camera, typically a charged couple device (CCD) and a lens in combination with an illumination source, sits in a stationary position and scans an image as a sheet of paper is moved past the camera, through a narrow transport path, by a paper transport mechanism. Individual raster lines are imaged by the camera and then pieced together to create a two-dimensional (2D) image representation of the original document. The camera is basically imaging one sliver of the document many times as the document is moved past the camera. The paper motion supplies one dimension of the document image, while the width is supplied by the camera. The in-paper travel direction and the width of the document are determined by the optics magnification and the dimensions of the CCD within the image forming subsystem. In alternative designs, a CIS or Contact Image Sensor is substituted for the CCD Lens Reduction form of camera or imager. The CIS device utilizes a number of smaller CCD elements chained together to form a full width imager. This eliminates the need for a reduction lens which is replaced by a self-focusing one of essentially 1:1 magnification. Both forms of cameras or imagers are commonly applied in sheet fed scanners as well as flat bed scanning equipment. In some cases, the shape of the sheet fed scanners paper path is semi-circular. For example, some scanners have a semi-circular paper path wherein sheets can be fed from a tray on top and exit beneath, or vice versa. In other cases, the paper path is “straight through.”
[0004] In some cases, the scanner has two cameras, one for imaging the front side of the sheet or document, the other for imaging the rear side of the sheet or document. Scanners of this form are typically referred to as single pass duplex in that they can image both sides of a document with one pass of the document through the paper transport. Sheet fed scanners employing only one imager are generally referred to as Simplex scanners. In some scanners with one imager or camera, the paper path is designed in a way to provide the ability to turn the sheet over thereby allowing for imaging of both sides, but this must be done in a second or reversing pass of the document, with a penalty of increased scan time.
[0005] FIG. 1 shows a typical sheet fed scanner with a C-shaped paper path and two cameras for duplex scanning of documents. To scan a stack of documents, a human operator places a stack of documents 10 , face up, on elevator input tray 11 and initiates a scan command through an attached computer (not shown) or a button or control panel (not shown) on the scanner. Drive rollers 16 begin to continuously rotate in direction 103 . Paper present sensor 17 determines that documents are in elevator input tray 11 and a motor (not shown) raises the tray to position the top of stack 10 against urging roller 13 . A motor and/or clutch (not shown) rotate urging rollers 13 and feed rollers 15 to pull the top document from stack 10 and move it into the continuously rotating transport rollers 16 which transport the document through curved transport path (C-shaped) 14 in direction 110 .
[0006] The documents are imaged by cameras 18 and 19 as they are pulled through the transport path 14 . Cameras include one or more illumination sources 196 that illuminate documents to be imaged by an electronic image sensor 192 . The image sensor can be a contact image sensor (CIS) or a charge-coupled device (CCD). In the case of a CCD imager, the camera typically includes a lens 198 and one or more mirrors 194 to fold the light path 199 between the imager and the document and create a more compact camera.
[0007] Scanned documents 12 are stacked face down in exit tray 20 , in the same order as they were fed into the scanner and scanned. When paper edge sensor 101 detects the lead edge of a document, the urging rollers and feed rollers are stopped from rotating to prevent feeding of more than one document. At this point, feed rollers 16 continue to rotate and pull the document through the urging rollers and feed rollers. After the trail edge of the document passes by paper edge sensor 101 , the urging rollers 13 and feed rollers 15 are again rotated (by motor and/or clutch not shown) to start moving the next document on the top of stack 10 into transport path 14 . In this way, documents are moved one at a time past cameras 18 and 19 to be imaged. Urging roller 13 is mounted to a housing 191 that freely pivots around the axis of the upper feed roller 15 , which is attached to the pod portion. Therefore as documents are fed from stack 10 , urging roller 13 drops by gravity onto the next document at the top of stack 10 . Stack-up sensor 102 detects when urging roller 13 (or its surrounding parts) drops below an optimal range for feeding documents. When this occurs, elevator 11 is raised by a motor (not shown) until stack-up sensor 102 detects that the stack is again in an optimal feeding position.
[0008] With reference to FIG. 2 , scanners with a C-shaped transport typically have a stationary base portion 122 and a moveable pod portion 120 that is connected by a hinge to the base. The pod can be lifted away from the base on its hinge to allow cleaning of cameras or to remove documents that may become jammed in the transport path. FIG. 2 shows a C-shaped sheet fed scanner with a pod portion 120 attached to a base portion 122 at hinge 124 with the pod in an open position. Such sheet fed designs are referred to as C shaped or “rotary” within the industry.
[0009] FIG. 3 shows a typical sheet fed scanner with a straight though paper path and two cameras (duplex) for scanning both sides of documents. Documents 10 are moved through a straight transport path 15 by a series of drive rollers 16 to be imaged by cameras 18 and 19 . In this case, documents 10 are pulled from the bottom of the input stack and are stacked 12 in exit tray 20 in the same order. Document stacks must be fed face down in order to scan them in the order in which they are stacked. If a straight through path were to be fed documents in a face up orientation, then the last document in the stack would be the first document scanned. The result would be that the scan order would be reversed from the stack order 12 in the scanner shown in FIG. 3 . In applications where many documents are scanned, customer expectations require that the original order be maintained. This is especially important in helping the customers recover from any jam, stoppage or other events that would require starting over or executing a “rescan”.
[0010] There are several customer usage benefits to the C or “rotary” design as compared to a straight through sheet fed scanner design. Since many of these advantages deliver improved productivity and improved ergonomics they become much more important in applications where many documents need to be scanned. Within the industry of production scanning where customers expect to scan more than a few tens or few hundreds of documents per day, the rotary or C shaped transport designs are the dominant product configuration. Following are some of the usage benefits of a Rotary or C shaped transport design.
[0011] Given the customer requirement to deliver the sheets to an exit tray in the same order as they were scanned, the options are to feed them through a straight path face down using a feeder that pulls the intended sheets into the transport from the bottom of the stack or use a C shaped transport where the sheets can be pulled from the top of stack. Pulling the sheets off of the top of the stack or a “top feeder” is advantaged in that it allows customers to place their documents into the tray face up. This is preferred because it is the normal way that customers read, prepare and handle multi page documents. It also allows the customer to observe how each sheet is to be treated as it enters the scanner. In the event that they observe a document beginning to be damaged or otherwise improperly fed, the operator may be able to intervene and correct a problem before it happens or before it has become more serious. In a bottom feeder, the operator must take the extra step to turn their documents over when placing them into the stack and they cannot as easily observe or intervene with sheets as they are fed from the bottom of the stack. In addition, feeding from the top of the stack is generally proven to be of higher reliability than feeding from the bottom of a stack. This is primarily due to the fact that each sheet in a top feeder has the same drag loads to overcome in order to advance it into the paper transport. In bottom feeding devices these drag forces are variable and dependent on how much stack resides above the sheet being fed. Each sheet being fed from beneath a stack must overcome the added drag forces incurred because of the weight of those sheets above it. This drives another key benefit of the top feeding approach which is capacity. Since top feeders do not have to contend with the weight of the stack, it is much easier to design top feeding systems using an elevating table with high stack capacities. Within the industry, top feeding devices are commonly delivered with stack capacities of 250, 500 or even 1,000 sheets while nearly all bottom feeding devices are limited to capacities of 50 to 150 sheets because of the stack drag force problem.
[0012] Another key benefit to the C or rotary design is in the ergonomic placement of the trays for in feed and exit. In the most ergonomic configurations, the C shape designs place the in-feed tray at a position close to the table or desk surface and the exit tray above it with the C shape paper path between them, such as shown in FIG. 1 , for example. It is also preferred that both of these trays are oriented with both trays facing the seated operator. This configuration allows for optimum interaction with the feed and exit trays with minimal reach between them to load and unload documents. While a C design can also be offered with the in feed tray on top and the exit tray at the bottom, the preferred design places the in feed tray close to the desk surface since most scanner interventions occur in the in-feed tray. By configuring this tray closer to a table top surface, it minimizes the lifting of the arms and hands to elevated positions in order to perform the scanning operations. Performing repetitive operations with the hands well above the desk surface has been proven to increase operator fatigue, discomfort and injuries to the neck and shoulders. In some scanner designs the in feed and exit trays are oriented in a sideways arrangement. This creates an awkward process for loading and unloading the documents.
[0013] In addition to the ergonomic benefits described for operating the scanner, a C or rotary design has the ability to provide optimal access to the entire paper path length when it must be opened up for jam clearance and or maintenance. In the typical C or Rotary design, the entire paper path can be opened or exposed by unlatching the pod and hinging it upward. When offered with this path oriented to face the seated operator, this arrangement offers excellent visual and manual access to the paper path. In some scanners of different configurations, the operator must open and close several sections of the paper path in order to gain visual and manual access and some of these are not easily accessible from a seated position.
[0014] In summary, a forward facing C shaped transport with the in-feed tray close to table height and the exit tray above it, which opens up through one hinge affords an optimal design for feeding reliability, capacity, desk space and ergonomics for operation and maintenance.
[0015] FIG. 4 shows a typical flatbed scanner. In a flatbed scanner, a single document 34 is placed face down onto a transparent glass 40 . The document is held flat to the glass by a pad 36 that is secured to the underside of cover 38 . Camera 30 is moved linearly along shaft 32 by a motor drive system (not shown) to image the document. Cover 38 is typically mounted to a scanner main body 31 with one or more hinges 42 that allow the cover to be rotated open in a direction 35 for document placement. Hinges 42 typically include sliding members 44 that are free to move in vertical slots 46 in the main body. This allows the cover to fully seat against thick or irregularly shaped documents or other items. Because they are not restricted by a narrow document transport path, flatbed scanners are able to scan documents and items not able to be transported through a sheet fed scanner, such as books, thick documents, and three-dimensional objects. In production scanning applications, the majority of all documents are able to be fed using a sheet fed scanner and this is far more productive than using a flat bed. However, some “exception” documents, such as those of irregular dimensions, are encountered that require the use of a flatbed type scanner. It is therefore desirable to create a product design that can optimize both of these capabilities into one device while maintaining the key advantages of each.
[0016] Product solutions currently exist that have some, but not all of the desired benefits of a C-shaped sheet fed scanner and a flatbed scanner in a compact size. One common method is to tether a flatbed scanner to a C-shaped sheet fed scanner. This method requires two separate devices and occupies a significant amount of desk space. FIG. 5 shows one such combination in which flatbed scanner 44 is connected to sheet fed scanner 42 by tether cable 46 . The cable provides an electronic digital communication medium between the scanners.
[0017] FIG. 6 shows another scanning system that combines a straight-through sheet fed scanner with a flatbed scanner. In this case, straight through sheet fed scanner 506 , with input tray 502 and output tray 504 , is mounted onto cover 510 of flatbed scanner 508 . Cover 510 pivots about a hinge axis 512 to provide document access to the flatbed. This has the disadvantages of the straight through sheet fed scanner and has the ergonomic issue of requiring a human operator to lift a heavy scanner in order to access the flatbed for document placement.
[0018] In another configuration, a rotary scanner is placed atop a flatbed design. FIG. 7 depicts this approach in which C-shaped sheet fed scanner 162 is positioned above flatbed scanner 168 . Sheet fed output tray 164 serves as a cover to flatbed 168 and is opened by rotating about the horizontal hinge axis 163 in direction 165 . Sheet fed input tray 166 extends above the flatbed and must be moved in direction 169 before the flatbed cover 164 can be opened. This is because the operating position of the input tray blocks the movement of the output tray as it is opened in direction 165 . In this design the ergonomic access to the input and output trays is suboptimum because they are loaded sideways and are elevated substantially from the desktop surface. The portion of this figure that is facing the viewer is deemed the front of the scanner, thus, the flatbed scanner is facing the front of the scanner apparatus because its cover 164 opens toward the front, while the output 164 and input 166 trays are facing a lateral side of the scanner because documents enter and exit the scanner in directions away from and toward that side, which is the right side of the scanner in FIG. 7 .
SUMMARY OF THE INVENTION
[0019] In a preferred embodiment of the present invention, a flatbed scanner is integrated into a forward-facing C-shaped sheet fed scanner in a location above the sheet fed cameras and below the document output tray. The output tray also serves as the flatbed cover and pivots about an axis near or coincident with the pod pivot.
[0020] A preferred embodiment of the present invention includes providing a flatbed scanner and a sheet fed scanner, an input tray for holding documents to be fed into the sheet fed scanner, and transporting the documents from the input tray along a transport path under the flatbed scanner, which path includes a pair of imaging devices for scanning different sides of the documents. The path then curves upward behind the flatbed scanner and again curves toward a front side of the flatbed/sheet fed scanner combination toward an output tray above the flatbed scanner. Rollers are used to pull the documents from the input tray into the transport path and also along the transport path all the way out to the output tray. In the present inventive design, the output tray also serves as a rotatable cover for the flatbed scanner.
[0021] Another preferred embodiment of the present invention includes affixing hinge mechanisms to a base portion of a scanner apparatus and rotatably attaching a pod portion to the hinge mechanisms. The pod portion includes a built-in flatbed scanner. A cover is attached to the same hinge mechanisms for covering the platen of the flatbed scanner and is also used for securely holding documents, books, or other items against the platen of the flatbed scanner during scanning. The cover and the pod portion are each separately rotatable about the axis that is created by the hinge mechanisms, because the hinge mechanisms are collinearly aligned as attached to the scanner apparatus. A transport path is formed in the region where the pod portion meets the base portion, and is exposed when the pod portion is rotated in an upward direction away from the base portion. The transport path includes one or more cameras for scanning one or more sides of the documents traveling through the transport path. Input and output trays serve to hold documents that are being fed into the scanning apparatus and that have been scanned by the sheet fed scanning portion.
[0022] Another preferred embodiment of the present invention includes providing a scanning machine having a sheet fed scanner and a flatbed scanner. An input tray is provided for supporting a document that is to be automatically fed into the scanning machine. One or more imaging devices along the transport path below the flatbed scanner image one or more sides of documents. The imaged documents continue along the transport path and are ejected into an output tray above the flatbed scanner. The output tray is attached to the scanning machine such that the output tray is rotatable to an open position to expose a platen of the flatbed scanner and is rotatable to a closed position to cover the platen. The flatbed scanner is built into a pod portion of the scanning machine and is rotatable to an open position to expose the transport path. The output tray and the pod portion are attached to the same hinge mechanism so that the output tray and the pod portion rotate together or independently about the same axis. A pad is affixed to the bottom surface of the output tray to provide a flexible surface that contacts the platen when the output tray is rotated to the closed position.
[0023] These, and other, aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention and numerous specific details thereof, is given by way of illustration and not of limitation. For example, the summary descriptions above are not meant to describe individual separate embodiments whose elements are not interchangeable. In fact, many of the elements described as related to a particular embodiment can be used together with, and possibly interchanged with, elements of other described embodiments. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. The figures below are intended to be drawn neither to any precise scale with respect to relative size, angular relationship, or relative position nor to any combinational relationship with respect to interchangeability, substitution, or representation of an actual implementation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 illustrates a prior art scanner with C-shaped paper path.
[0025] FIG. 2 illustrates the prior art scanner of FIG. 1 in a pod open position.
[0026] FIG. 3 illustrates a prior art scanner with a straight paper path.
[0027] FIG. 4 illustrates a prior art flatbed scanner.
[0028] FIG. 5 illustrates a prior art tethered sheet fed and flatbed scanner system.
[0029] FIG. 6 illustrates a prior art combination sheet fed and flatbed scanner system.
[0030] FIG. 7 illustrates a prior art combination rotary and flatbed scanner system.
[0031] FIG. 8 illustrates an embodiment of the present sheet fed and flatbed scanner system via a lateral side cross-section view.
[0032] FIG. 9 illustrates a perspective view of the scanner system of FIG. 8 .
[0033] FIG. 10 illustrates a perspective view of the scanner system of FIG. 8 with the output tray/flatbed cover in an open position.
[0034] FIG. 11 illustrates a lateral side cross-section view of the scanner apparatus of FIG. 10 .
[0035] FIG. 12 illustrates a perspective view of the scanner system of FIG. 8 with the pod portion in an open position.
[0036] FIG. 13 illustrates a lateral side cross-section view of the scanner apparatus of FIG. 12 .
[0037] FIG. 14A illustrates a perspective view of an optional embodiment of the scanner system of FIG. 8 with the output tray/flatbed cover removed to expose one of the hinge mechanisms.
[0038] FIG. 14B illustrates a close-up of a portion of FIG. 14 .
[0039] FIG. 14C illustrates an exploded view of a portion of FIG. 14A with base housing removed.
[0040] FIG. 15A illustrates a perspective view of an optional embodiment of the scanner system of FIG. 8 .
[0041] FIG. 15B illustrates a close-up of a portion of FIG. 15 .
[0042] FIG. 16 illustrates one of the pair of hinge mechanisms of the scanner system of FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
[0043] The invention is disclosed herein as being embodied preferably in a document scanner. Because the features of a document scanner are generally known, as exemplified by the description above, the description which follows is directed in particular only to those elements forming part of or cooperating directly with a preferred embodiment of the present invention. It is to be understood, however, that various elements of the preferred embodiments described herein may take various forms known to a person of ordinary skill in the art.
[0044] Referring now to the drawings, FIG. 8 shows a side view cross section through a scanner 100 of a preferred embodiment of the present invention. A back side of the scanner 121 , opposite the front side, is to the right in FIG. 8 . The scanner is comprised of a stationary base portion 122 , a moveable pod portion 120 and a moveable output tray/flatbed cover 20 . Pod portion 120 and output tray/flatbed cover 20 can both pivot or rotate relative to each other and together they can pivot/rotate relative to base portion 122 , at horizontal hinge axis 124 created by hinge mechanisms described below. The output tray 20 is at an open position when it is rotated upward (see FIGS. 10 and 11 ) and is in a closed position when it is rotated downward and is adjacent to the flatbed scanner, as is shown in FIG. 8 . Scanner 100 provides duplex, sheet fed, C-shaped scanning and flatbed scanning functions. The sheet fed scanner input tray, output tray and the flatbed cover are all situated to face forward toward the human operator located in front of scanner 100 , which is to the left in FIG. 8 . FIG. 9 illustrates a perspective view of the scanner shown in FIG. 8 with like numerals indicating like elements.
[0045] Referring again to FIG. 8 , to scan a stack of documents 10 , a human operator places them, face up, on elevator input tray 11 which supports the documents and initiates a scan command through an attached computer (not shown) or a button or control panel (not shown) on the scanner. Automatic operation of the scanner then proceeds as follows: drive rollers 16 begin to continuously rotate in direction 103 ; paper present sensor 17 determines that documents are in elevator input tray 11 and a motor (not shown) raises the tray to position the top of stack 10 against urging roller 13 ; a motor and/or clutch (not shown) rotate urging rollers 13 and feed rollers 15 to pull the top document from stack 10 and move it into the continuously rotating transport rollers 16 which transport or convey the document through rotary transport path (C-shaped) 14 in direction 110 ; the documents are imaged by cameras 18 and 19 as they are pulled through the document transport path 14 , eventually to be stacked face down in exit tray 20 . The cameras include one or more illumination sources 196 that illuminate documents to be imaged by a CCD image sensor 192 . The cameras include a lens 198 and one or more mirrors 194 to fold the light path 199 between the imager and the document and create a more compact camera.
[0046] Scanned documents 12 are stacked face down in exit tray 20 , in the same order as they were fed into the scanner and scanned. When paper edge sensor 101 detects the lead edge of a document, the urging rollers and feed rollers are stopped from rotating to prevent feeding of more than one document. After the trail edge of the document passes by paper edge sensor 101 via rollers 16 , the urging rollers 13 and feed rollers 15 are again rotated by motor and/or clutch (not shown) to start moving the next document on the top of stack 10 into transport path 14 . In this way, documents are moved one at a time past cameras 18 and 19 to be imaged. Urging roller 13 is mounted to a housing 191 , that freely pivots around the axis of the upper feed roller 15 , which is attached to the pod portion 120 . Therefore as documents are fed from stack 10 , urging roller 13 drops by gravity onto the next document at the top of stack 10 . Stack-up sensor 102 detects when urging roller 13 (or its surrounding parts) drops below an optimal range for feeding documents. When this occurs, elevator 11 is raised by a motor (not shown) until stack-up sensor 102 detects that the stack is again in an optimal feeding position.
[0047] Transport path 14 is formed by surfaces 91 of base portion 122 and surfaces 93 pod portion 120 . This transport path is noted as the region between the pod portion and the base portion, with a beginning near the input tray and an exit near the output tray. After documents are scanned, they are advanced into output tray 20 where they are stacked face down, in the same order in which they were placed in input tray 11 . Camera 18 resides in pod portion 120 to image the top of fed documents and camera 19 resides in base portion 122 to image the bottom of fed documents. In a preferred embodiment of the present invention, the cameras use CCD imagers. However, these cameras optionally can be either linear CCD imagers or linear contact image sensors (CIS). Located vertically above cameras 18 and 19 and disposed vertically below output tray 20 within pod portion 120 is a flatbed scanner 130 . Flatbed scanner 130 includes a clear glass platen 134 , for document placement, and a camera 136 , which can be either of the linear CIS or linear CCD type that images the underside of documents placed onto glass platen 134 . A preferred embodiment of the present invention uses a CIS camera for the flatbed because of its small size. Camera 136 is driven along a gear rack, track, or shaft 86 (shown in FIG. 10 ) in, or parallel to, the long direction of the flatbed scanner by a motor 132 in a manner common to flatbed scanners.
[0048] FIG. 10 illustrates a perspective view of the scanner shown in FIG. 9 with output tray 20 in an open position exposing clear glass platen 134 . As shown in FIG. 10 , flatbed scanner 130 is arranged so that camera 136 moves along direction 82 which is perpendicular to the direction of paper transport through the sheet fed scanner, shown as direction 110 . Direction 82 is deemed the long direction of the flatbed scanner and clear glass platen.
[0049] Sheet fed scanner output tray 20 also serves as the cover for flatbed scanner 130 . Its top surface serves as the output tray and its underside, or bottom surface, acts as a cover for the flatbed scanner. In particular, for the platen of the flatbed scanner. Pad 21 is adhered to the underside of output tray 20 and it forces documents flat against flatbed glass 134 by pressing against them for scanning when closed as shown in FIG. 9 . It is preferably formed of a flexible material in order to conform to the shape of documents or items placed on the flatbed platen. To place a document into scanner 100 for flatbed scanning, output tray 20 is lifted as shown in FIG. 10 , pivoting about horizontal axis 124 ( FIG. 8 ) and exposing platen glass 134 for document placement.
[0050] FIG. 11 is similar to FIG. 8 in that it shows a side view cross section through scanner 100 but with cover 20 in an open position, also pivoted about horizontal axis 124 , while FIG. 12 is a perspective view of a scanner 100 , similar to FIG. 9 , but with pod 120 pivoted to an open position, and FIG. 13 shows a side view cross section through the scanner 100 as shown in FIG. 12 with pod 120 in an open position, with like numerals indicating like elements throughout the figures. As shown in FIGS. 11 and 13 , output/exit tray 20 pivots about the same horizontal axis 124 created by the hinge mechanisms as the pod 120 . The output tray and pod pivot or rotate independently about this axis as shown, for example, in FIG. 13 , which also illustrates the further axial reach of the output tray 20 as compared to the pod 120 .
[0051] FIGS. 14A-C and 15 A-B show a preferred embodiment of the hinge mechanisms forming axis 124 . In FIGS. 14A-C the output tray 20 has been removed to show the hinge mechanisms portion on one side of the pod portion 120 . Pod portion 120 is pivotally attached to base portion 122 via these hinge mechanisms. Bearing 150 is pressed into wall 146 of pod portion 120 . Bearing 150 rotates about post 148 , which is affixed to wall 144 of base portion 122 . Referring to the detail of FIG. 14C , which has base housing removed to expose base frame 154 , hinge post 148 is welded or riveted to metal plate 151 , which is secured to the base frame 154 with screws 153 . To assemble the scanner, the pod 120 is positioned in the base to align its bearing with the pivot axis location 124 , then the output tray (flatbed cover) 20 is likewise positioned at the axis. Then the plate 151 with hinge post 148 is screwed onto the base frame 154 . A similar hinge/bearing arrangement at location 160 , collinear with the hinge mechanism shown, completes the pod hinge mechanisms. FIGS. 15A-B show output tray 20 pivotally attached to base portion 122 , via the hinge mechanisms, over the same post 148 . In this case, an opening 152 in wall 150 of the output tray fits over post 148 . A similar bearing arrangement at location 161 completes the output tray hinge mechanisms. FIG. 16 shows a preferred embodiment of opening 152 to be a slot that is oriented vertically when output tray 20 is in the closed position. This slot configuration allows output tray 20 to fully seat against thick or irregularly shaped documents that are placed on the platen for scanning.
[0052] As shown in FIG. 15 , primary user controls and/or displays 149 are positioned on surfaces that face forward toward the front of the scanner in direction 145 , which define those surfaces as the front of the machine. Output tray 20 and input tray 11 extend in the same direction to provide forward facing access for the most ergonomic user interface.
[0053] This configuration affords all the ergonomic benefits of the traditional rotary or C-shaped sheet fed scanner—high capacity input tray with ergonomic position close to the table surface, forward-facing trays with minimal span between them to minimize reach, forward-facing single hinge access to the rotary paper path—while also offering ergonomic flatbed scanning for exception documents even when the sheet fed input and output trays are filled with documents.
|
An ergonomic, compact scanner operation is achieved by providing a flatbed scanner and a sheet fed scanner in a space efficient arrangement with optimal access features for users. Documents traverse the sheet fed scanner along a path that allows inclusion of an easily accessible flat bed scanner.
| 7
|
TECHNICAL FIELD
[0001] This invention relates to garments, and more particularly, to garments and similar fabric suited for use in health care environments.
DESCRIPTION OF PRIOR ART
[0002] As a result of their treatment, dialysis patents commonly experience cold sensation and desire to be completely covered to minimize this heat-loss. A dialysis patient completely covered by a blanket obstructs the view of the needle access site necessary for the healthcare personnel to perform their duties.
[0003] One of the risks associated with dialysis treatment is serious injury or possible death caused by dislodgement of the fistula needle. Because fistula needles are much larger in size and gauge than a typical needle attached to a syringe, they undergo significant pressure, which may result in dislodgement. Incidents of needle dislodgement are not uncommon.
[0004] The risk of serious injury as a result of needle dislodgement increases with the use of a blanket obstructing the view of a patient's needle access site. When used, blankets require constant monitoring by healthcare personnel, including lifting the blanket to view the needle access site, which causes discomfort to the patient. Additionally, it is inefficient for a minimal staff attending to multiple patients simultaneously to continuously lift and inspect each patient's access site.
[0005] In light of the deficiencies of ordinary blankets and the need for warmth of dialysis patients, a new garment, adapted to provide constant viewing access to hospital staff, would have significant utility.
SUMMARY OF THE INVENTION
[0006] A garment for providing warmth and insulation to dialysis patients while maintaining unobstructed visual access to a patient's needle access site is described.
[0007] The garment is worn draped over a patient's body with their head through the opening near the center, or put on sideways through the adjustment strip. The adjustment strip lies on either shoulder, (depending on access site location) and provides both length and temperature adjustment to ensure proper window positioning and patient comfort. The garment may be worn in any position of a dialysis chair or hospital bed, including upright, semi-reclined, fully reclined, and in the Trendelenburg position. The garment can also be worn prior to or after treatment, when walking or otherwise being transported.
[0008] The garment may be constructed with any soft fabric with insulating properties. Polar fleece is well suited for this application due to its lightweight and hydrophobic properties. Further, it retrains its insulating characteristics even when wet, and is machine washable and dries quickly. The fleece material is commonly available in varying thicknesses, providing different degrees of warmth.
[0009] The window (or windows) can be customized for any number of applications, and positioned anywhere on the front panel of the garment, where a surgical or access site is located. The window may be made of any flexible clear material that can be attached to the garment.
[0010] Polyvinyl chloride provides a fully transparent window with reasonable flexibility and is widely produced.
[0011] The garment provides pleasant range of motion without feeling restrictive. The garment, having a back section, provides an additional barrier between the patient and dialysis chair, further minimizing the risk of cross-contamination. The garment optionally includes a hood and/or a foot-pouch, designed to retain heat to a patient's head and their feet. The garment also optionally includes one or more pockets for convenience of the patient or the staff.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIGS. 1A and 1B are diagrams of a patient wearing the medical garment with transparent window while standing with arms stretched ( FIG. 1A ), and seated in an upright position ( FIG. 1B );
[0013] FIG. 2 is a diagram of a patient wearing the medical garment with transparent window while lying in a reclined position;
[0014] FIG. 3 is a top-view diagram of a medical garment with transparent window made in accordance with a second variation of the present invention;
[0015] FIGS. 4A and 4B are a close-up view of the adjustment strip; and
[0016] FIG. 5 is a close-up view of the transparent window.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] Referring to FIG. 1A , a patient ( 10 ) stands with a medical garment or gown ( 11 ) having a transparent window ( 12 ) thereon. With the arms ( 10 a, 10 b ) stretched, the transparent window ( 12 ) can be readily seen located in a proper position covering most of the left arm of the patient for dialysis treatment. With the provision of the transparent window ( 12 ) the whole situation can be readily monitored without removing the gown from the patient. Now referring to FIG. 1B , which is a diagram showing the patient ( 10 ) wearing the medical garment or gown ( 11 ) with transparent window ( 12 ) while seated in an upright position. It can be readily seen that the transparent window ( 12 ) of the medical garment ( 11 ) is positioned over the needle access site or area ( 13 ) allowing unobstructed visual access to the bloodlines ( 14 ), needles, and medical devices commonly utilized in a dialysis procedure. It can be readily appreciated that with the transparent window ( 12 ), the ongoing process of dialysis can be readily monitor without rending any uncomfortable handling to the patient ( 10 ).
[0018] FIG. 2 is a diagram of a patient ( 20 ) wearing the medical garment ( 21 ) with transparent window ( 22 ) while lying in a reclined position. The transparent window ( 22 ) of the medical garment ( 21 ) is again properly positioned over the needle access site or area ( 23 ) allowing unobstructed visual access to the bloodlines ( 24 ), needles, and medical devices commonly utilized in a dialysis procedure.
[0019] FIG. 3 is a top-view diagram of a medical garment ( 31 ) with transparent window ( 32 ) incorporated thereon in accordance with a variation of the present invention. This medical garment ( 32 ) is similar to the medical garment ( 11 ) shown in FIGS. 1A and 1B while with little variation. The medical garment ( 30 ) is constructed primarily with fabric designed to retain an individual's body heat, such as, but not limited to, polar fleece. The medical garment ( 30 ) is further comprised of a head opening ( 31 h ), typically cut midway between points 31 a and 31 c, while illustrated at 31 b. From the side of head opening ( 31 h ), the medical garment ( 30 ) is cut to its edge, providing adjustment strip ( 33 ) therealong.
[0020] FIGS. 4A and 4B are close-up view of the adjustment strip ( 33 ). The adjustment strip ( 33 ) is composed of matching rows of connecting arrangements ( 35 ), such as Velcro, snaps, zippers, buttons, or other means generally available to the skilled in the art for connecting the opposing sides ( 32 a, 32 b ) of the adjustment strip ( 33 ) of the medical garment ( 30 ). In this referred embodiment, buttons and holes are used as the connecting arrangement 35 and arranged along the opposing sides ( 32 a, 32 b )of the medical garment ( 30 ).
[0021] Returning to FIG. 3 , the medical garment ( 31 ) is further composed of a transparent window ( 32 ) positioned below the adjustment strip ( 33 ). Transparent window ( 32 ) may be constructed of any non-permeable material providing unobstructed view, such as, but not limited to, polyvinyl chloride.
[0022] FIG. 5 is a close-up view of the transparent window ( 12 , 22 , 32 ). The transparent window ( 12 , 22 , 32 ) is positioned over a hole or opening ( 11 h, 21 h, 31 h ) cut into the medical garment ( 11 , 21 , 31 ). The hole or opening ( 11 h, 21 h, 31 h ) should be cut to a size sufficiently large to provide an unobstructed viewing window to most patient's needle access site ( 13 , 23 ), see FIGS. 1A, 1B and 2 . The transparent window ( 12 , 22 , 32 ) may be permanently or temporarily affixed over hole ( 11 h, 21 h, 31 h ) with means that securely maintain the position of the transparent window ( 12 , 22 , 32 ) in relation to the hole or opening ( 11 h, 21 h, 31 h ). Permanent attachment means may include, but are not limited to, such as gluing, stitching, melting, compressing, or weaving. Temporary attachment means may include, but are not limited to, Velcro, snaps, zippers, or buttons. This invention provides the transparent window ( 12 , 22 , 32 ) designed to offer viewing access to a site typically at risk for dialysis patients. However, the transparent window ( 12 , 22 , 32 ) and hole or opening ( 11 h, 21 h, 31 h ) may be repositioned to provide viewing access to any other body area as a result of surgery, such as over and section of the torso, or any other limb. The use of the dialysis patient example in this patent is not to be considered a narrowing of use of the invention described herein, nor any rights associated with this patent.
[0023] Returning to FIG. 3 , the lower portion of the medical garment ( 31 ) optionally includes a foot-pouch section ( 34 ). The foot-pouch ( 34 ) may be extended or folded under a patient's feet and secured with two rows of connecting arrangements ( 35 ), such as, but not limited to, Velcro, snaps, zippers, or buttons. The medical garment ( 31 ) optionally includes one or more pockets ( 36 ), and a hood ( 37 ).
[0024] It is contemplated for embodiments of the invention to extend to individual elements and concepts described herein, independently of other concepts, ideas or systems, as well as for the embodiments to include a combinations of elements recited anywhere in this patent. Although illustrative embodiments have been described in detail, it is understood that the invention is not limited to those precise embodiments. Many modifications and variations of the inventions described herein will be apparent to those skilled in the art. Accordingly, it is intended that the scope of the invention be defined by the following claims and their equivalents. Furthermore, it is contemplated that a particular feature described either individually or as part of an embodiment can be combined with other individually identified features, or parts of other embodiments, even if the other features or embodiments make no mention of the particular feature. The absence of describing combinations is not intended to preclude the inventor form claiming rights to such combinations.
|
A garment for providing warmth and insulation to dialysis patients while maintaining unobstructed visual access to a patient's needle access site is described. The garment includes a transparent window and is made from a fabric material tailored to provide front and back covering. The garment includes a head opening with peripherally connected means for adjustment; and at least one transparent window providing viewing access to a particular location.
| 0
|
FIELD OF THE INVENTION
This invention relates to the induction system of an internal combustion engine, and more specifically to a telescopic throttle body for the induction system.
BACKGROUND AND SUMMARY OF THE INVENTION
In a typical induction system, the throttle body is disposed at a location between the air intake portion and the air distribution portion. The air intake portion typically contains a filter, and the air distribution portion typically contains a plenum, or manifold, with runners leading to the individual engine cylinders. A typical process for assembling the various parts of such an induction system together comprises mounting the throttle body on a plenum or manifold flange, and then connecting the air intake to the inlet of the throttle body. In order to minimize the extent of assembly operations that are required to fabricate an induction system, it has become desirable to integrate components.
The present invention relates to a throttle body of an induction system in which a portion of the induction system that is immediately upstream of the throttle body is integrated with a portion that is immediately downstream of the throttle body such that the throttle body must be fitted between mounting flanges that are spaced a fixed distance apart from each other. The present invention relates to a throttle body that can be expeditiously and reliably assembled into such an integrated system. Generally speaking, the present invention comprises a throttle body fabricated to have two telescopically engaged body parts that are selectively operable to a telescopically contracted condition and to a telescopically expanded condition. When its two body parts are in the telescopically contracted condition, the throttle body can be disposed between the two mounting flanges of the integrated system. The two parts are then operated to telescopically expanded condition to cause the inlet and outlet flanges of the throttle body to mate with the respective mounting flanges. A locking feature is also provided by the invention for the purpose of locking the two parts in telescopically expanded condition after the respective flanges have been mated. O-ring seals are provided between each pair of mated flanges so that a fluid-tight path for the induction flow is provided. There is also an O-ring seal between the two body parts. It is desirable to include a locking means that positively locks the two body parts in the telescopically expanded condition so that removal of the throttle body is prevented after it has been telescopically expanded and locked.
In a specific embodiment of the invention, camming means and cammed means are provided on the respective body parts for the purpose of operatively relating them such that when they are in telescopically contracted condition, relative rotation of one to the other about their co-axis will cause them to be telescopically expanded. A further feature related to the camming means and the cammed means is the provision of detent means defining the respective telescopically contracted and telescopically expanded conditions.
The present invention enables an integrated air-fuel system to be fabricated more efficiently and to be assembled with greater expediency, and it enables the throttle body to be quickly and properly located and assembled into the induction system. The invention is particularly suited for an induction system in which the throttle body must be disposed between two mounting flanges that are spaced a fixed distance apart, such as when the mounting flanges are integrated into a single part of the induction system, although it should be appreciated that the invention may be useful in other forms of induction systems.
Further features, advantages, and benefits of the invention, along with those already mentioned, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings illustrate a presently preferred embodiment of the invention according to the best mode contemplated at this time for carrying out the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a portion of an exemplary induction system including a throttle body according to principles of the invention.
FIG. 2 is a left side elevational view, having a portion broken away, in the direction of arrow 2 in FIG. 1, but illustrating the throttle body having been assembled into the induction system.
FIG. 3 is a side elevational view of the throttle body by itself in the telescopically contracted condition with certain portions broken away.
FIG. 4 is a top plan view of FIG. 3 and includes a portion of the induction system relating to the locking feature mentioned earlier.
FIG. 5 is a view similar to the view of FIG. 3, but illustrating the telescopically expanded condition.
FIG. 6 is a top plan view of FIG. 5, and includes the locking feature shown in locking condition.
FIG. 7 is a fragmentary cross-sectional view taken in the direction of arrows 7--7 in FIG. 6.
FIG. 8 is a view similar to the view of FIG. 3, but illustrating another embodiment of throttle body in the telescopically contracted condition.
FIG. 9 is a view similar to the view of FIG. 8, but illustrating the throttle body in the telescopically expanded condition.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 illustrate an exemplary induction system 10 of an internal combustion engine. The induction system comprises a member 12 having a fresh air entrance 14 through which inducted air enters for ensuing passage to and through a filtering zone 16 containing an air filter which is not expressly shown in the drawing figure. After inducted air has been filtered, it passes through an elbow 18 which is also an integral part of member 12.
Member 12 further comprises a manifold 20 that is disposed so as to be spaced below elbow 18. Manifold 20 contains a centrally located mounting flange 22 that is co-axially juxtaposed to a mounting flange 24 at the terminus of elbow 18. It is between elbow 18 and manifold 20 that a throttle body 26 of the present invention is disposed to provide a fluid-tight continuation for the induction air flow from the elbow to the manifold.
To either side of mounting flange 22, there are two runners leading from the manifold to individual cylinders of the engine, runners 28 and 30 on the left as view in FIG. 1 and runners 32 and 34 on the right. Associated with each runner is an electromechanically operated fuel injector 36 that is poised to inject fuel toward the intake valve(s) of the cylinder served by the corresponding runner.
Further details of throttle assembly 26 can be seen in FIGS. 3-7. It comprises a throttle body having two telescopically engaged body parts 38 and 40. Body part 38 has a generally tubular shape comprising a bore 42 of circular cross section. Part 40 also has a generally tubular shape comprising a bore 43 and telescopes over the upper end of body part 38 as seen in FIGS. 2, 3 and 5. The throttle valve mechanism of throttle body 26 is contained in body part 38 and comprises a throttle blade 44 on a shaft 46 that is journaled in the wall of body part 38 and operated by means of an external lever 48 to set the amount of throttling.
Figs. 1 and 3 illustrate throttle body 26 with its two body parts 38, 40 in a telescopically contracted condition. In this condition, the overall axial dimension of the throttle body is less than the distance between mounting flanges 22 and 24 to allow throttle body 26 to be disposed between and in co-axial alignment with them. After having been so disposed, the two parts 38 and 40 are operated to telescopically expanded condition represented in FIGS. 2 and 5 wherein a flange 50 provided at the upper end of part 40, i.e. at the throttle body inlet, mates with mounting flange 24 and a flange 52 at the lower end of part 38, i.e. at the throttle body outlet, mates with mounting flange 22. In this condition, the entirety of bore 42 and that portion of bore 43 that is above the upper terminus of bore 42 provide a continuance of the induction passage from elbow 18 to manifold 20. Three O-ring seals are provided to assure proper sealing, and they are a lower O-ring seal 54 that seals the throttle body outlet end to mounting flange 22, an upper O-ring seal 56 that seals the throttle body inlet end to mounting flange 24, and an O-ring seal 58 that seals between the telescopically overlapping portions of body parts 38 and 40.
For properly circumferentially locating the throttle body assembly in installed position, a locating means is provided. This locating means comprises a pocket 60 in a wall 62 of member 12 directly behind the installed throttle body assembly and a complementary projecting formation 64 on the exterior of part 38. In this instance the pocket and complementary projection are rectangular in shape. As can be seen in FIG. 2, the projection 64 lodges in pocket 60 to provide the proper circumferential location of the throttle body in the installed position.
It is also desirable to provide a locking means for locking the two parts 38 and 40 in telescopically expanded condition. Such locking is accomplished in two ways, one by providing a locking catch mechanism, and two by providing a locking band, or collar. The locking catch mechanism takes the form of a radial arm 65 that projects radially outwardly from part 40 and a tab 66 that projects externally from wall 62. The lower face of arm 65 contains an integral headed stud 68 and the distal end of tab 66 contains a forked receptacle 70 for receiving the shank of stud 68. When the throttle body is in the process of being assembled into the induction system, arm 65 is disposed approximately in the position shown in FIG. 1 so as to be in a non-interference relationship with tab 66. Once the telescopically contracted body parts 38, 40 have been placed in co-axial alignment with mounting flanges 22 and 24, the two body parts can be telescopically expanded without arm 65 interfering with tab 66. After the throttle body has been telescopically expanded, part 40 is rotated in a counter-clockwise sense as viewed in FIG. 1 to bring arm 65 into overlying relationship with tab 66 and concurrently cause the shank of stud 68 to be received in receptacle 70 in a snap-catch fashion. With the two body parts telescopically expanded, there exists a space 72 between the lower edge of part 40 and a flange 74 extending around the exterior of part 38. A resiliently expansible collar or band 76, of slightly more than semi-circular extent, is inserted over body part 38 in this space to provide an interference between the lower edge of body part 40 and flange 74 which prevents the two body parts from being telescopically contracted.
FIGS. 8 and 9 illustrate a second embodiment of throttle body in which the same reference numerals are used to designate the same parts that were previously described in connection with the first embodiment. The embodiment of FIGS. 8 and 9 differs from the first embodiment in that the two body parts 38 and 40 comprise respective camming means 78 and cammed means 80. The camming means and cammed means are fashioned in respective confronting surfaces 82, 84 of the two parts which extend around the exterior of each. In the telescopically contracted condition of FIG. 8, the surfaces rest against each other in a congruent manner. The two parts are operated from the telescopically contracted condition to the telescopically expanded condition by relatively rotating the two parts in opposite directions about their co-axis. The sliding motion of the one cam surface along the other creates the telescopic expansion. Respective abutment stops 86, 88 are provided in the two parts to define the limits at which full telescopic expansion is reached. Camming means 80 is provided with respective detents 90, 92 that define the respective conditions of telescopic expansion and telescopic contraction.
While a presently preferred embodiment of the invention has been illustrated and described, it should be appreciated that principles of the invention are applicable to other embodiments which are equivalent to the following claims.
|
A throttle body has telescopically engaged parts that allows it to be telescopically contracted for insertion into the induction system at assembly and then telescopically expanded to secure its installation.
| 5
|
FIELD OF THE INVENTION
The present invention relates generally to a measurement apparatus and technique. More particularly, the present invention relates to an angle measurement apparatus and technique with a remote sensor.
BACKGROUND OF THE INVENTION
Accurate measurement of angles is important in a variety of fields including for example the manufacturing industries such as the automotive field. Measurement of such angles is also critical and difficult when being limited in confined spaces.
For example, proper alignment of wheels of an automotive vehicle is important for both proper handling of the vehicle, as well as proper tire wear. One of the wheel alignment parameters, which is measured and adjusted in order to achieve proper wheel alignment, is the caster angle.
Caster is an angle which the steering axis of a steerable wheel makes with respect to a vertical plane which is perpendicular to the longitudinal direction of the vehicles. The caster angle is considered positive when the steering axis is inclined rearward (in the upward direction) and negative when the steering axis is inclined forward. Caster can be measured by inclinometers attached to the wheel. To measure caster, the wheel is turned through an arc, and the difference in camber readings is used to derive the caster value. The camber angle is the inclination of the wheel plane with respect to the vertical. The camber angle is another parameter that is used for wheel alignment along with the caster angle.
Current wheel alignment tools are not able to accurately measure the caster angle in a convenient, efficient and accurate manner. Current angle measurement tools are large and the reading of measurements is difficult when measuring the angles due to low clearance or inaccessibility. For example, current angle gauges will not fit in confined spaces where the rear casters of the vehicles are located. Further, the current equipment is unable to include a remote display of the angle that is required when measuring in an inaccessible space, while displaying the measurement in a convenient and efficient manner.
Other wheel alignment tools can be placed underneath the car to take measurements of the angles. However, even laser range finders cannot get an accurate measurement.
In some recent models of vehicles, such as the 2006 versions of the PONTIAC SOLSTICE and SATURN SKY from GENERAL MOTORS, Inc., the vehicles have adjustable rear casters. In an effort to achieve mass reductions, GENERAL MOTORS made the decision to have a body rear structure that eliminated the rear frame. There is a need to measure the adjustable rear casters. However, the confined space available for the measurement of the caster angle and the size of the current tools make it very difficult to measure the angles. Thus the conventional tools cannot be used to measure angles, such as the caster angle of certain vehicles.
Accordingly, it is desirable to provide a technique and apparatus for measuring angles in confined spaces while still being able to display the measurement in a convenient manner for the user.
SUMMARY OF THE INVENTION
The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus and technique are provided that in some embodiments allows the user to measure angles in confined spaces while still allowing the user to efficiently input instructions and receive the angle measurements without interference.
In accordance with one embodiment of the present invention, a remote sensing angle gauge is provided, and can include a sensor unit including a sensor responding to physical stimulus and transmitting a resulting impulse for measuring an angle, and an interface unit separate and remote from the sensor unit and in communication with the sensor unit, the interface unit receiving a signal from the resulting impulse of the sensor unit, the interface unit determining the angle measurement according to the received signal from the sensor unit and inputted data from the interface unit.
In accordance with another aspect of the present invention, a method of remotely sensing an angle is provided, including setting a zero point with respect to an area being measured, receiving an offset value from an input unit and storing the offset value in a memory unit, receiving through an input unit a selection of an orientation of a sensor, and determining the angle measurement according to the data received from the sensor and input signals received for the offset value, and orientation of the sensor.
In accordance with yet another embodiment of the present invention, an apparatus for angle measurement is provided, and a sensor unit including a housing enclosing a sensor responding to physical stimulus and transmitting a resulting impulse for measuring an angle, and an interface unit in communication with the sensor unit, the interface unit receiving a signal from the resulting impulse of the sensor unit, the interface unit determining the angle measurement according to the received signal from the sensor unit and inputted data from the interface unit.
There has thus been outlined, ratherbroadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
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 embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view illustrating a remote digital angle gauge according to a preferred embodiment of the invention.
FIG. 2 is a block diagram of the internal modules of the remote digital angle gauge of FIG. 1 .
FIG. 3 is a top or bottom view of the remote sensor unit of FIG. 1 .
FIG. 4 is a side view of an alternative embodiment of the remote sensing digital angle gauge with an adaptor mechanism attachment.
FIG. 5 illustrates the angle measurement in the area shown in FIG. 4 .
FIG. 6 illustrates the technique of determining the angle measurement in the remote sensing digital angle gauge.
DETAILED DESCRIPTION
The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present invention provides a remote sensing angle gauge, including a remote sensor for measuring an angle, and a user interface separate and remote from the sensor and in communication with the sensor. The user interface receives a signal from the resulting impulse of the sensor, and the user interface unit determines the angle measurement according to the received signal from the sensor and inputted data from the user interface. The present invention also provides a technique of remotely sensing an angle, including setting a zero point with respect to an area being measured, receiving an offset value from an input unit and storing the offset value in a memory, receiving through an input unit a selection of an orientation of the sensor, and determining the angle measurement according to the data received from the sensor and input signals received for the offset value, and orientation of the sensor. Thus, the angle gauge and the technique of the angle gauge provide a user an accurate way to measure angles in confined spaces, efficiently input instructions and receive the measured angle measurements remotely without interference.
An embodiment of the present inventive apparatus is illustrated in FIG. 1 . In one embodiment, the apparatus of the present invention is a digital angle gauge 10 with a user interface unit 12 and a sensor unit 14 (discussed below). The user interface 12 includes a display unit 16 and an array of indicators 18 . The display unit 16 will display, for example, the angle measurement, while the array of indicators 18 will inform the user of the function being used (further discussed below). The display unit 16 can be a digital display. The display unit 16 can be, for example, a liquid crystal display or other display unit capable of displaying alphanumerical and/or numerical values.
FIG. 2 is a block diagram of the internal modules of the remote digital angle gauge of FIG. 1 . The display 16 is controlled by a central processing unit 24 (discussed below) and by the driver 44 . The array of indicators 18 can include, for example, light emitting diodes or other indicators capable of signaling to the user of the function being used. The user may select the different functions of the digital angle gauge through input keys such as the function up and down keys 20 and activate one of the input keys 20 for entering the selection. When a certain function is selected, the particular indicator such as the light emitting diode 18 is activated to show the function being used. Each one of the indicators 18 can be labeled to inform the user with regard to the significance of each one of the indicators 18 . For example, one indicator 18 may stand for the angle measurement of the driver side, another represents the angle measurement for the passenger side, while a third indicator 18 can represent zeroing function and a fourth indicator 18 represents an offset function. Other functions can also be included that relate to the angle measurement. The different functions of the digital angle gauge 10 will be described below.
The sensor unit 14 can connected to the user interface unit 12 through a wire or wirelessly. When the user interface unit is connected to the sensor unit through a wire 46 as seen in FIGS. 1 and 2 , a coiled type cord such as a telephone type cord can be used to make the wire management efficient, while allowing the user to reach the sensor unit into certain confined spaces. The wire 46 between the sensor unit 14 and the user interface unit 12 can be a certain length and can be detachable or fixed as desired.
Referring to FIG. 6 , the sensor unit 14 can communicate wirelessly to the user interface unit 12 through wireless protocols such as BLUETOOTH, IEEE (Institute of Electrical and Electronic Engineers) 802.11, etc. The user interface unit 12 can also include a fastening portion 62 that allows the user interface unit 12 to be attached to a stationary object for a hands-free reading by the user while measuring the angle. For example, the fastening portion 62 can be a self-storing support such as a hook or other mechanism capable of hanging the user interface unit beneath the vehicles to be measured.
Turning back to FIG. 2 , the user interface unit 12 of the digital angle gauge 10 includes the central processing unit (CPU) or controller 24 that controls the digital angle gauge 10 . The CPU is connected with a memory unit 26 that stores data and instructions that are used by the digital angle gauge 10 . The memory unit 26 can be a computer readable media. A user can input data and instruction into the digital angle gauge 10 through one of the keys in the input unit 20 . The indicators 18 and display unit 16 are also controlled by the CPU 24 . The user interface unit 12 is encased in an assembly 32 . The digital angle gauge 10 can be powered by a power source 42 , which can be a primary (non-rechargeable) battery such as an alkaline battery, or a secondary battery (rechargeable battery) such as a lithium ion, lithium polymer, nickel metal hydride (NiMH), etc. The power supply 42 can also be a connection to an external power source.
Through an interface 28 on the user interface unit 12 , the interface unit 12 is connected to the sensor unit 14 by a wire 46 as seen in FIG. 2 or a wireless communication link as seen in FIG. 6 . The sensor unit 14 is encased by an assembly 22 and includes a sensor 36 . The sensor 34 can further include an accelerometer to sense change in the movement of the assembly 22 . The change in movement is displayed as an angle measured in degrees via the display on the user interface unit 12 . As states above, the sensor unit 14 can communicate the measured angles via a wire or wireless connection. The sensor 34 can also be detachable to accommodate the replacement of the sensor independent of the remote display in terms of the user interface unit 12 . When the sensor unit 14 is wirelessly connected to the user interface unit 12 , the remote sensor unit 14 can also include a power supply of its own. The sensor unit 14 , for example, can be attached to the rear suspension on the vehicles, and used to measure the actual caster angle.
The sensor unit 14 is further illustrated in FIGS. 3 and 4 . Referring to FIG. 3 , the sensor unit includes a notch 38 centered on the back of the housing 22 . The notch 38 receives detachable pins 60 that allow the mounting of the sensor unit 14 to various parts of the vehicle in order for a user to take measurements in a more efficient manner. Mounting the sensor unit 14 in a confined space allows for a better measurement and the ability to reach into difficult to reach areas. The notch can include, for example, sections with thicknesses “a” and “b” and width “c” at the opening being greater than the thickness “d” at the closed portion of the notch. The notch 38 can have many other configurations and the above description in FIG. 3 is not limited to the configuration shown. The configuration of the assembly 22 of the sensor unit 14 is also not limited to such a configuration, but may include various other shapes and sizes. The sensor assembly can be small enough and be in certain shapes to accommodate being placed in certain confined areas such as regions in a vehicle that require an angle measurement and avoids any interference from other portions of the vehicle that would prohibit an accurate measurement of the angle.
Referring to FIG. 5 , the sensor unit 14 can be placed in confined space to measure an angle, while still allowing a user to monitor the angle measurement in a viewable location outside of the confined space through the separately located user interface unit 12 . As seen in FIG. 5 , the small remote sensor 36 in the small sensor unit 14 accommodates for accurate angle measurements where conventional gages will not fit. Current wheel alignment tools do not allow for measuring the rear caster, but as seen in FIG. 5 , the angle of the rear caster and a variety of other angle measurements can be made. The separation of the sensor unit 14 from the user interface 12 allows the remote use of the sensor 34 so that the user can measure angles where conventional inclinometers and angle meters will not fit.
The applications for measuring angles are not limited to the caster angle in vehicles. A plurality of other types of angle measurements can be made. The digital angle gauge 10 is universal in its application. The digital angle gauge, for example, can be used for the GENERAL MOTORS Y car and any other non-steerable (rear axle) caster angle measurement, steering wheel angle measurement, driveshaft angle measurement, and frame angle measurement, etc. An example of the angle measurement taken by the present invention is the measurement of the rear caster. Other uses include placing the gauge 10 on a building to measure any desired angles, use any type of vehicle, etc. Furthermore, the caster angle can be measured at any corner (wheel) of the vehicle.
Referring to FIG. 6 , at step 100 , a user can activate the offset button by using one of the input keys 20 , thus lighting up one of the plurality of indicators 18 showing that the offset is being selected. The offset number is entered so that the user can get the proper reading of the gauge 10 as related to the service manual. For example, when the service manual states that the castor has to be three degrees positive, and the steering knuckle is cocked three degrees negative, then if the user were to measure from the zero point, the gauge would instead read zero. Therefore, rather than obtain such a reading, the user can enter an offset number so the user can get a proper reading from the gauge 10 as related to the service manual. If a user knows at zero, dead center (e.g., the position of a crank when it is in line with the connecting rod and not exerting torque), and a user knows that the steering knuckle is cocked a certain amount of degrees, a user can type the offset number in the user interface unit 12 . The offset number is stored in the memory unit 26 for use by the CPU 24 .
At step 110 , and referring to FIG. 6 , the sensor unit 14 can be placed on the hoist that the vehicle is on and zeroed (step 110 ). A user may place the sensor on the hoist itself, and zero the sensor accordingly. The zeroing gives the starting point between the level of the vehicle and level of the earth so that there is a zeroing of the gauge 10 in relationship to the hoist that the vehicle is on and the vehicle itself. Alternatively, the offset can be entered after zeroing the gauge 10 , and therefore, steps 100 and 110 can be interchanged. The plurality of indicators 18 indicates to the user the selected menu, including illuminating a certain indicator when offset or zeroing is selected through the input keys 20 .
At step 120 , the user would position the sensor unit in the area to be measured. For example, the sensor unit 14 can be positioned in the vehicle to measure the angle, as seen in FIG. 5 . Other examples include placing the sensor unit having the pins 60 ( FIG. 4 ) in machined holes in the area to be measured in order to accommodate proper attachment. A wide variety of adaptors can be used for the specific area or purpose of measurement.
As another example, but not limited by such a configuration, two dowel pins 60 are placed on the back portion of the sensor unit 14 . The sensor unit 14 is slotted and has a t-slot 38 as seen in FIG. 3 . The two pins 60 fasten into the mating of the t-slot 38 , and the two pins 60 fit into the holes in the knuckle of the vehicle as seen in FIG. 5 . The sensor unit 14 can be attached to the knuckle or spindle assembly. The gauge 10 with the t-slot 38 and pins 60 can accommodate any distance between the holes up to the limit of the length of the sensor unit 14 . Different center to center distances can be included for the pins 60 depending on the application.
The adaptor increases the universal applicability of the gauge 10 to a variety of different uses. The adaptor mechanism such as the pins 60 is adjustable and replaceable. An adaptor unit does not have to be used, but accommodates a fastening to an area to be measured, thus allowing user to free a hand when reading the measurement.
The adapter mechanism 60 can also be positioned relative to the sensor 34 . For example, as seen in FIG. 3 , the notch 38 is centered on the back of the sensor housing allowing an accurate reading. The sensor unit 14 can be mounted with multiple adapters to accommodate the gauge 10 to fit in a variety of purposes including for example present and future vehicle applications.
Referring back to FIG. 6 , at step 130 the user would then enter in the user interface unit 12 whether negative or positive angle of the castor. The driver side or passenger side is selected depending on the orientation of the sensor, thus giving a positive or negative reading. The appropriate indicator 18 would illuminate to indicate whether the passenger or driver side is selected.
At step 140 , the gauge 10 then determines the angle measurement and displays the information on the display unit 16 for reading by the user away from where the angle is being measured and/or in a location that the display unit is easy to read. The angle measurement is determined by the CPU 24 with access to the memory unit 26 , through the information received from the accelerometer sensor 36 . The information from the accelerometer sensor 36 is received through the interface 28 on the user interface unit 12 . The display unit 16 indicates whether the caster angle is positive or negative at any corner (wheel) of the vehicle.
The angle measurement can be stored in the memory 26 or it can be not stored in the memory 26 , but simply displayed on the display unit 16 for an indefinite or certain period of time, or until the gauge 10 is re-zeroed.
The gauge 10 is re-zeroed to accommodate another vehicle or other application. For example, different vehicles have different weights that would tilt the hoist in one direction or another and so the gauge should be re-zeroed again. Further, the gauge 10 can be manually turned off by using the input key 20 or automatically turned off after no activity for a certain period of time.
The order of the steps 100 - 140 are not limiting and maybe applied in a different order or multiple steps may be performed at the same time, and additional steps can be performed and also certain steps can be not performed. For example, if no offset value is needed, step 100 can be skipped, or if the gauge 10 does not have to be re-zeroed, the zeroing step 110 can be skipped.
The present invention can be realized as computer-executable instructions in computer-readable media. The computer-readable media includes all possible kinds of media in which computer-readable data is stored or included or can include any type of data that can be read by a computer or a processing unit. The computer-readable media include, for example, and not limited to storing media, such as magnetic storing media (e.g., ROMs, floppy disks, hard disk, and the like), optical reading media (e.g., CD-ROMs (compact disc-read-only memory), DVDs (digital versatile discs), re-writable versions of the optical discs, and the like), hybrid magnetic optical disks, organic disks, system memory (read-only memory, random access memory), non-volatile memory such as flash memory or any other volatile or non-volatile memory, other semiconductor media, electronic media, electromagnetic media, infrared, and other communication media such as carrier waves (e.g., transmission via the Internet or another computer). Communication media generally embodies computer-readable instructions, data structures, program modules or other data in a modulated signal such as the carrier waves or other transportable mechanism including any information delivery media. Computer-readable media such as communication media may include wireless media such as radio frequency, infrared microwaves, and wired media such as a wired network. Also, the computer-readable media can store and execute computer-readable codes that are distributed in computers connected via a network. The computer readable medium also includes cooperating or interconnected computer readable media that are in the processing system or are distributed among multiple processing systems that may be local or remote to the processing system. The present invention can include the computer-readable medium having stored thereon a data structure including a plurality of fields containing data representing the techniques of the present invention.
An example of a computer, but not limited to this example of the computer, that can read computer readable media that includes computer-executable instructions of the present invention includes a processor that controls the computer. The processor uses the system memory and a computer readable memory device that includes certain computer readable recording media. A system bus connects the processor to a network interface, modem or other interface that accommodates a connection to another computer or network such as the Internet. The system bus may also include an input and output interface that accommodates connection to a variety of other devices.
Although an example of the remote sensing digital angle gauge is shown using the gauge of FIGS. 1 through 6 , it will be appreciated that other gauges can be used. Also, although the digital angle gauge is useful to measure the caster angle in the automotive field, it can also be used for any type of angle measurement in any field.
The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
|
A remote sensing angle gauge includes a sensor responding to physical stimulus and transmitting a resulting impulse for measuring an angle, and a user interface separate and remote from said sensor and in communication with said sensor unit. The user interface receives a signal from the resulting impulse of said sensor unit, and determines the angle measurement according to the received signal from said sensor unit and inputted data from said interface unit. The inputted data by a user includes an offset and orientation of the sensor. The gauge can be zeroed before initiating the measurement. The sensor can be connected to the user interface through a detachable electrical connection. The sensor can include an adaptor accommodating a detachable and adjustable connection to an area being measured. The results of the measurement on the user interface can be remotely monitored, while measuring the angle with the sensor.
| 6
|
FIELD OF THE INVENTION
[0001] This invention related to power tongs for making oil field connections and more particularly to power tongs for sucker rods and tubing connections.
BACKGROUND OF THE INVENTION
[0002] Systems referred to as power tongs have been widely used for some time in oil field installations for making and breaking connections between end threaded products which are to be united into a string by couplings which join the products end to end. Such products include sucker rods which extend downhole within tubing or casing and provide drive power for pumping petroleum to the surface. Other strings are also made up using power tongs, and these include tubular products in the form of tubing and casing.
[0003] As the technology has developed, the threaded connection between the elements in the string has had to become more precise and stronger because of increasing demands placed on the string. As the strings have increased in length consistent with wells drilled to greater depth, they have also encountered higher pressures, and ever higher loads and forces. More secure connections are thus needed to enable the downhole equipment to be utilized for longer periods of time, with higher reliability.
[0004] Sucker rods have pin ends which are threaded without a taper, and reliance is placed on making a shoulder connection which is properly prestressed to withstand the forces that are to be encountered in cyclic pump operation over a long duration. Tubing and casing, on the other hand, utilize tapered threads, and are subject to both internal and external forces and combinations thereof. Also, the integrity of the connection between male and female threads is a consequence not only of the degree of engagement but of the dimensional tolerances that are permissible.
[0005] An improvement in sucker rods is evidenced by U.S. Pat. No. 6,942,254 and application Ser. No. 09/960,391 of Kenneth J. Carstensen which both disclose a connection in which the end faces of the pin ends of the sucker rods engage each other either directly or via an intermediate torque disk. The connection is made up to a first operative point at which the pin ends are under initial compression and the coupling is then further tensioned to a further precise degree. This arrangement unites the component parts of the sucker rod connection in a manner such that they withstand the varying forces encountered during the action of a reciprocal or rotary pump, and resist the development of microcracks and consequent fatigue failures.
[0006] The practical economic and throughput requirements at operating wells do not justify or permit the installation of expensive and complicated systems for instrumenting the measurement of torque or displacement values. It is much preferred to utilize a torque applicator, specifically a power tong system, to apply a precise amount of torsional force so that the connection is mechanically secure and repeatable. In this regard, the sucker rod configuration of the referenced Carstensen patents places a high premium on a capability for prestressing the sucker rod connection with a high degree of precision. Also, since the same power tong must also function in the break mode (disengagement) it should perform all the needed functions as they are required.
SUMMARY OF THE INVENTION
[0007] A system for coupling the threaded ends of oil field connections to be made up into a string utilizes alternative sources for turning a rotary element engaged to the elements to be coupled together. A first motive source is a rotary drive for spinning the element to an initial engagement state, then a second longitudinally driven element with a variable but predetermined hydraulic pressure limit applies the desired final precise torsional force. The force applied by the longitudinally driven element can be precisely measured by a sensor, so that the torque applied can be raised to a present value within accurate limits.
[0008] An improved power tong in accordance with the invention, more particularly, utilizes a combined dual function drive mechanism which is capable of operating the driven element, namely the sucker rod, tubing or casing in both a spinning mode and a precise torque application mode. As used for sucker rods, the wrench flat of the sucker rod is entered within a spinner mechanism and engaged by cam operated gripping mechanisms which are urged inwardly as a rotary drive is turned about the wrench flat. The rotary drive includes a hydraulic motor with internal step down gears turning a drive gear on a shaft adjacent the periphery of a large rotary cam gear with outer peripheral teeth. The drive gear is not coupled to the teeth on the ring drive directly but via idler gears on each side of it which engage the peripheral teeth. In an initial spinning mode, the motor turns the rotary ring drive which in turn drives the gripping mechanisms and the sucker rod. This continues until a shoulder on the sucker rod that is adjacent the wrench flat engages the end of the coupling sleeve in the sucker rod connection. Once this position is reached, the spinning is stopped, and a wholly different engagement mode is activated to complete precise torquing. A gear rack adjacent the idlers is shifted into engagement with the peripheral teeth of the idlers. Then a double acting hydraulic cylinder coupled to the gear rack moves it laterally until a selected and controlled limit is reached, by turning the ring drive and the engaged sucker rod until a precise rotational force level is established by an associated sensor. This prestresses the connection between the sucker rods, by virtue of the physical engagements of the sucker rods with the coupling sleeve, and provides superior realization of the benefits of the Carstensen sucker rod improvement referenced above. When a predetermined strain limit is reached, the drive cylinder is shut off and the gear rack is disengaged from the idler gears. The spinning action of the rotary ring drive is then reversed, and centrifugal force disengages the gripping heads from the wrench flat. The tongs can then be drawn away from the sucker rod via the passageway provided in the spinner section. Strain gage measurements show that the limit of torque that is applied to prestress the sucker rod connection is extremely accurate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A better understanding of the invention may be had by reference to the following description taken in conjunction with the accompanying drawings, in which:
[0010] FIG. 1 is a cross-sectional plan view, of a power tong system in accordance with the invention;
[0011] FIG. 2 is a side sectional view of the power tong system of FIG. 1 ;
[0012] FIG. 3 is an end sectional view of the mechanism of FIGS. 1 and 2 ;
[0013] FIG. 4 is a side sectional view of the mechanism taken from a different angle, showing further details of the system;
[0014] FIG. 5 is a plan view of the tong housing with the cover and internal parts removed;
[0015] FIG. 6 is a combined perspective and block diagram view of the power tong system;
[0016] FIG. 7 is a fragmentary view of a backup mechanism used in gripping the sucker rod during make and break operations;
[0017] FIG. 8 is a block diagram of the principal elements of a power tong for sucker rod connections in accordance with the invention, and
[0018] FIG. 9 is an enlarged fragmentary view of a stress sensor mounted in a hydraulic shaft used in the lateral drive.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring now to FIGS. 1-7 , a power tong in accordance with the invention is shown as it is configured for sucker rod operation. The component parts are disposed within a rugged tong housing 10 comprising a full height rear section 12 joined to a reduced height front section 14 . In the front section 14 , a wrench flat access slot or passageway 16 provides a pathway for receiving the wrench flat portion of a sucker rod at a position which will be called the wrench flat axis. This axis is usually vertical, and the entry pathway therefore is usually horizontal. A rotary cam gear 20 in the form of a robust ring drive disk having peripheral teeth 22 and an interior cam surface is concentric with the wrench flat axis and positioned in the front section 14 . Within the rotary cam gear 20 , the peripheral teeth 22 are positioned at mid-height between upper and lower rings 24 , 26 which also form part of the rotary gear. The rotary cam gear 20 has a circumferential opening which provides a radial slot complementary to that in the front section 14 of the housing and is aligned with it when engaging and disengaging to wrench flats. The rotary gear 20 nonetheless rotates about the central axis because it is peripherally retained within a set of spaced apart rollers 27 disposed about the cam gear periphery, and each having upper and lower rollers 27 a and 27 b ( FIGS. 2 and 4 ) engaging the ring surfaces 24 , 26 so as to hold the rotary cam gear in concentricity with the wrench flat axis as it is driven.
[0020] An interior surface 28 ( FIG. 1 ) of the rotary gear 20 is configured to provide two opposing cam lobes 29 , 29 ′ facing the wrench flat axis. The peripheral rollers 27 are mounted between flat upper and lower carrier plates 40 , 42 and the opposite faces of the drive disk portion of the rotary cam gear 20 are held relative to the carrier plates 40 , 42 by aluminum bronze friction segments 44 ( FIG. 4 ) which engage the rotary gear 20 to hold it in planar position transverse to the wrench flat axis.
[0021] A pair of gripping heads 46 a and 46 b are disposed on opposite sides of the wrench flat axis and, in the position of the rotary gear 20 shown in FIG. 2 , are also approximately perpendicular to the entry slot 16 . The gripping heads 46 each include inwardly facing teeth 47 (see FIG. 5 ) directed toward the wrench flat axis and cam follower rollers 48 in contact with the cam surface 28 . When in contact with the interior surface of the rotary gear 20 , the cam follower rollers 48 and the gripper head assemblies are of sufficient size and strength to withstand the substantial forces involved in making a connection and applying torque.
[0022] The drive in the rear section 12 operates in two modes. First, for spinning the sucker rod, it is coupled to a hydraulic motor 52 ( FIGS. 4 and 6 ) directly engaged to a shaft 54 that is vertical with respect to the principal plane of the rotary cam gear 20 . The shaft 54 is held between upper and lower bearings 56 , 58 respectively and is coupled to a drive gear 60 ( FIG. 4 ) positioned adjacent but spaced from the peripheral teeth 22 on the rotary cam gear 20 . The hydraulic motor 52 may include internal step down gearing (not shown) to provide a desired combination of torque and rotational velocity. The shaft 54 mounted drive gear 60 engages separate adjacent idler gears 62 , 63 (see FIG. 1 ) which mesh with the peripheral teeth 22 on the rotary cam gear 20 . The idler gears 62 , 63 rotate on short shafts (not shown) mounted in the top and bottom surfaces, respectively, of the rear section 12 of the housing.
[0023] In the second mode of operation, the rotary cam gear 20 receives motive power from a gear rack 70 which is initially held at a space from the idler gears 62 , 63 , as seen in FIG. 1 . The gear rack 70 is attached to a double acting hydraulic cylinder 72 ( FIG. 3 ) which has a 10 ″ stroke and is operated by a hydraulic control 73 ( FIG. 6 ). The cylinder 72 is supported in a C frame 74 ( FIGS. 1-3 ) fixed to the housing 10 at its ends, which abut the sidewalls of the rear section 12 . Shafts 75 , 75 ′ coaxial with the cylinder 72 and mounted in the housing wall provide axial sliding support for the cylinder 72 and associated gear rack 70 . A stress sensing transducer 152 , as described in more detail below in conjunction with FIG. 9 , is disposed in one of the shafts for providing a precise measurement of the torque applied.
[0024] The C frame 74 is movable in both directions, toward and away from the wrench flat axis, within a number of oval cam surfaces 76 (best seen in FIG. 5 ) in the top and bottom walls of the C frame 74 , which receive cam followers 78 that are spaced apart in the transverse direction parallel to the cylinder 72 . These cam mechanisms allow a range of motion toward and away from the rotary drive 20 , so as to engage the gear rack 70 with the idler gears 62 , 63 , and release it from same under hydraulic control.
[0025] The drive motion for engaging and disengaging the gear rack 70 is provided by drive cylinders 80 , 81 mounted in the rear section 12 against the back wall thereof, and positioned perpendicular to the gear rack axis. The drive cylinders 80 , 81 engage a pair of drive brackets 83 , 83 ′ ( FIGS. 1 and 2 ) which are coupled to the C frame 74 . After the initial spinning of the rotary gear 20 brings the shoulder on the sucker rod pin end into contact with the end of the coupling, the connection is ready for prestressing. To this end, the operator engages an actuator ( FIG. 6 ) which activates the control hydraulic controls 112 , which include the sensor 152 to shut off the gear rack drive when a selected stress limit has been reached. This sensor may be a strain gage, a piezoelectric transducer, or any other of the many devices for providing the needed degree of precision.
[0026] Thus the power tongs in accordance with the invention utilize different modes of operation, so as to first engage the opposed gripping heads 47 ( FIGS. 1 and 5 ) against the wrench flat on the sucker rod by action of the double lobed cam surface 29 . Then the rotary gear 20 spins the sucker rod until the shoulder limit is reached and the drive stops, automatically or under operation control, as with the mechanisms shown in FIG. 6 . Then the gear rack 70 is engaged to by first shifting in to engage the idler gears 62 , 63 then driving to provide final increment of torque, but this time by lateral movement of the gear rack 70 so as to turn the sucker rod, until the predetermined limit is reached. The torque limit can be very precisely set, because it can be measured by modern strain gauge technology. The gear rack 70 can then be disengaged and the rotary drive reversed, this reversal causing the gripping heads to release by centrifugal force, so that the sucker rod can be removed and replaced with a new connection that is to be made up.
[0027] A practical example of a system in accordance with the invention is shown in perspective view in FIG. 6 , in fragmentary perspective view in FIG. 7 and with the principal control elements being shown in the block diagram of FIG. 8 . The sucker rod 100 extends vertically down through the front section 14 of the housing 10 , fitting within the passageway 16 that is provided for access. The sucker rod 100 includes a conventional wrench flat 102 ( FIG. 7 ) and an adjacent extending shoulder 104 with the pin end being threaded into a coupling 106 joined to a second sucker rod 108 .
[0028] On the power tong assembly ( FIG. 6 ), control hydraulics 110 , 112 are shown on opposite sides of the top of the tong housing 10 . Details of the valve and interconnections are not shown for simplicity and because numerous conventional hydraulic expedients are available. At one side of the housing is a control lever 114 coupled into the first control unit 110 , for activating the spinning mechanism. On the other side of the housing 10 are a pair of control levers 120 , 122 engaged to the control hydraulics 112 on that side. These control levers control separate actuation of the spinning drive of the rotary cam gear 20 , and also allow separate lateral gear rack operation. Both of these actions are later reversed for disengagement functions.
[0029] Handles 128 for manual operation of the tongs are disposed on each side of the housing to enable moving the power tongs, which are separately supported in conventional fashion, into operating position. The assembly, however, can alternatively be operated remotely in a robotic fashion, when assembling a string of sucker rods. In such an automatic operation, successive sucker rods are simply fed through the system, and automatically timed operations are undertaken in sequence, first spinning the sucker rod until shoulder engagement is encountered, then activating the gear rack to provide the selected level of prestress, and operating to disengage the tongs from the connection, so that the string can be advanced to the next connection point where the process is repeated.
[0030] Details of the backup mechanism 120 are shown in the fragmentary perspective view of FIG. 7 , in which it can be seen that gripper elements 121 , 122 are spaced apart to receive opposite sides of a wrench flat 102 for a previously made connection, so that it can be held fixed as the upper sucker rod 100 is spun into position and then prestressed.
[0031] The principal elements used in tightening a sucker rod connection to a first stop limit and then to a precise prestress limit are shown in block diagram form on FIG. 8 , to which reference is now made. The operator controls 150 are exerted by the levers shown in FIG. 6 , and start the spinner drive 5 b , which turns the drive ring 20 through the coupling gears 62 , 63 until it reaches a physical stop in the improved Carstensen sucker rod configuration, as encountered. Then the spinner drive 50 is stopped, and the lateral drive 70 is first engaged to the coupling gears 62 , 63 . Then the drive 70 is actuated by the operator, linearly moving in to engage the coupling gears 12 , 13 and subsequently turn the drive ring 20 and the connection itself.
[0032] The stress sensor 152 is coupled to a support shaft 74 or 75 for the lateral drive to signal that a chosen prestress limit has been reached. As seen in FIG. 9 , powering of the drive rack 70 in either direction is caused by a concomitant increase in hydraulic pressure, which is sensed with high precision by the transducer 152 , so that the drive can stop automatically or under operator control.
[0033] Various alternatives will suggest themselves to those skilled in the art, but it is to be understood that the invention encompasses all forms and variations in accordance with the appended claims.
|
A power tong system for precisely making up a connection between two elongated elements, such as sucker rods, into an operative string for petroleum well installations. High precision is attainable to secure the full advantages of prestressing the coupling by combinatorial use of both a rotary drive to achieve a first contact position and a linear drive to secure a precise final torsioning. The mechanism for achieving this may employ a peripherally driven drive ring coupling gears engaged to the drive ring periphery, a rotatably driven drive and a linear gear rack which are both engageable to the coupling gear.
| 4
|
CONTRACTUAL ORIGIN OF THE INVENTION
The United States Government has rights in the invention pursuant to Contract No. W-31-109-ENG-38 between the U.S. Department of Energy and the University of Chicago.
BACKGROUND OF THE INVENTION
The present invention relates generally to a method and apparatus for supporting a structure such as a building, bridge, or power plant such that it is isolated from seismic vibratory ground motion. More particularly, the present invention relates to a method and apparatus for supporting a structure by an isolation system which will not allow large dynamic loads to be transmitted to the supported structure due to seismic motions which have damaging energy at frequencies at or near the natural frequency of the structure and the overall structural systems.
Two methods are used to prevent damage to buildings and other structures due to vibratory ground motion of seismic events. One method, the current conventional approach, is to embed the base of the structure onto firm soil and construct the structure to withstand seismic motion by providing adequate strength, rigidity and ductility. Use of this conventional method may incur significant costs of construction. In addition, it permits the seismic motion to be passed upward through the structure with resulting amplification of seismic accelerations and forces, thus requiring further precautions to prevent possible injury or death to occupants and costly damage to contents. The second method for preventing structural damage due to seismic events commonly known as seismic isolation, diminishes the seismic forces passed on throughout the structure, i.e. it decouples the structure from the earthquake ground shaking by supporting the base of the structure on a system of isolator bearings, which are, in turn, supported by a lower foundation mat, which is embedded upon the soil or rock.
The seismic isolation method of protecting a structure and its contents from seismic motion is based on the response of structures to vibrating motion at the base of the structure. If the fundamental natural frequency of the support and structure is sufficiently below the dominant or high energy content frequencies of the seismic motion, the structure will be subjected to greatly reduced seismic loading as compared to the more conventional method. Historical records of many damaging earthquakes in the world show that the seismic motion is observed to have most of the damaging potential energy at frequencies between 1 and 10 Hz. At the present time, seismic isolation systems are typically designed to create a support and structural system which has a natural frequency of less than 1.0 Hz, in some cases as low as 0.1 Hz.
Structures and equipment and others contents within the structure are generally more susceptible to damage from seismic motion in the horizontal plane than in the vertical direction. A common practice in seismic isolation design, therefore, is to isolate the structure from ground motion only in the horizontal plane. This isolation is achieved by supporting the structure by isolator bearings which, with the structure, form a dynamic system that has a horizontal natural frequency much lower than the non-isolated structure. The vertical natural frequency is usually designed to be very high, and is greater than the dominant frequencies of the vertical seismic ground motion. The structure will consequently not be significantly excited by the expected seismic event; it is noted, however, that certain portions of the structures such as beams and slabs, and certain equipment or other contents within the structure may have lower natural frequencies, and may be subjected to the same amplified considerations and loads experienced in the conventional design method.
Structures and in particular, components and systems contained within the structures, that are inherently susceptible to damage due to excitation by seismic motion are most efficiently protected by the isolation method. An example of this is a Nuclear Liquid Metal Reactor (LMR) vessel which is a thin walled structure having low natural frequencies and is therefore susceptible to seismic damage. The reactor vessel is a critical component of the reactor which must be reliably protected from earthquakes. Isolation of the reactor as a means of protecting it from damage must be achieved with a high degree of a reliability to assure safety of the LMR. Other highly critical facility examples include emergency facilities such as hospitals, in which many items of equipment as well as staff and patients are mobile and very vulnerable to horizontal seismic forces.
The frequency content of seismic motion at a given site is dependent on a variety of variables such as the geology of the site and consequently is best described as random. As a consequence, seismic motion that has significant energy at or near the isolation frequency is a possibility.
Therefore, in view of the above, an object of the present invention is to provide a method and apparatus to isolate a structure from seismic motion that will not allow large seismic loads to be transmitted to the structure. Another object of the present invention is to increase the assurance that an isolation system will not allow large seismic loads to be passed to a structure beyond that provided by isolation systems that do not provide for significant alteration of the natural frequency of the structure and isolation system. Additional objects, advantages and novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
To achieve the foregoing and other objects in accordance with the purposes of the present invention, as embodied and broadly described herein, the invention may comprise a generally horizontal lower mat that may be embedded in soil or otherwise provide support, an upper mat that is vertically adjacent to the lower mat which is an integral part of the supported structure and is the only location of support of the structure, and a plurality of structural isolator bearings each coupled to the upper and lower mats. At least one structural isolator is rigidly coupled to the upper and lower mats, primary isolator bearing, and at least one structural isolator is rigidly coupled to one mat and coupled to the other mat by a means to allow engagement and disengagement or slippage of the mat and isolator as a result of relative displacement of the upper and lower mats, secondary isolator bearings.
The present invention provides assurance that large horizontal motion of the structure will not occur by providing a means for changing the natural frequency of the support and structure system in response to relative horizontal displacement of the upper and lower mats that is caused by seismic motion near the natural frequency of the support and structure system. Maintaining a separation between the dominant frequency of the seismic motion and the natural frequency of the structure and support system provides greater assurance of safety than is provided by isolation system which have a single natural frequency.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated in the accompanying drawings wherein:
FIG. 1 is an elevation view of a nuclear island containing a critical facility which is supported by structural isolator bearings.
FIG. 2 is an illustration of a frictional contact embodiment of the invention which allows slippage of a structural isolator bearing and a mat in response to large shear force.
FIG. 3 is an illustration of a gap and contact embodiment of the invention for engaging a second structural isolator bearing and a mat in response to large horizontal relative displacement. These isolator bearings do not provide any horizontal resistance until such large displacements occur.
FIG. 4 is an illustration of the acceleration response of a structure, supported in one case by a single frequency isolator system, 41, and in another case by a multi frequency isolator system, 43, that are subjected to single frequency motion.
DETAILED DESCRIPTION OF THE INVENTION
The present invention which isolates a structure such that it will not experience large horizontal seismic load due to seismic motion at or near the natural horizontal frequency of the support and structure system comprises changing the horizontal natural frequency of the support and structure system as a result of relative horizontal displacement of the structure and lower mat that is larger than a predetermined value, or as a result of the shear force transmitted through the isolator exceeding a predetermined value. The predetermined displacement or shear force value is selected to be a value that is greater than the maximum value that would be expected due to seismic load at a frequency that is not at or near the natural frequency of the support and structure system. By shifting the horizontal natural frequency of the support and structure system in response to larger than expected isolator bearing shear force or relative displacement of the structure and lower mat, the relative displacement or transmitted shear force will be limited to a value that results from seismic motion at a frequency that is separated from the natural frequency of the support and structure system.
The present invention, as illustrated in FIG. 1, comprises supporting a structure on isolator bearings, 13, which are coupled to the upper mat of the structure, 11, and a soil embedded lower mat, 12. Isolator bearings that are rigidly coupled to the upper and lower mats are primary isolator bearings. Primary isolator bearings always support the structure and contribute to support stiffness in both vertical and horizontal directions. Isolator bearings that are rigidly coupled to one mat and may engage and disengage or slip with respect to the other mat are secondary isolator bearings. Secondary isolator bearings' contribution to horizontal stiffness is dependent on the relative motion of the upper and lower mats as illustrated by embodiments described below. Vertical support of the structure by secondary isolator bearings is a result of the requirements of the embodiment of the invention. Contribution to horizontal stiffness of the support of the structure by secondary isolator bearings, and the consequent alteration of the natural frequency of the support and structure system, in response to relative horizontal motion of the mats or shear force in the secondary isolator bearings form the basis of the embodiments of the present invention.
The upper and lower mats may be any structural material which will support the structure. Concrete is commonly used for structures of the type that are likely to be supported by the present invention. Structural steel is a commonly used material for support of structures, either alone or in combination with concrete. Use of steel in combination with concrete as reinforcement and as attachments to concrete such as embedded plates is well known and governed by standard practices and structural standards. Structural isolator bearings of various construction have been used for seismic isolation. A description of the design of a building's seismic isolation system with a natural frequency of 0.5 Hz is described in Megget, "The Design and Construction of a Base-Isolated Concrete Frame Building in Wellington, New Zealand", Proceedings of the Eighth World Conference on Earthquake Engineering, Volume 5, 1984, Prentice Hall, Inc.
The apparatus which allows slippage of an isolator bearing and a mat due to transmitted shear force may comprise two contact pads, 23 and 25 of FIG. 2, one anchored to a mat as illustrated by the upper mat, 11, and one anchored to an isolator bearing 13. The contact pads abut each other with generally flat horizontal surfaces which transfer vertical load through the isolator bearing, 13. The contact pad material and surfaces and the vertical load carried by the contact pads are specified so that horizontal slippage of the contact pads will occur when horizontal shear forces exceed a design value. The design value is specified to correspond to the force of the isolator bearing due to horizontal relative displacement of the upper and lower mats that is greater than expected to occur due to seismic motion at a frequency which is separated from the natural frequency of the structure and support system.
The contact pad embodiment of the present invention may be practiced by use of design and construction methods that are well known. As an example, for a maximum transmitted shear force F max , the materials and surfaces of the contact pads must be specified so that slippage will occur for that value. Static coefficients of friction for various material pairs and surfaces are given in standard handbooks. The vertical load carried by the isolator F v is a known design variable. Any materials that will support the vertical load and whose static coefficient of friction is F max /F v will satisfy the maximum shear force criteria. Attachment of the contact pads to the isolator bearing and mat may be accomplished by the types of attachment that are used for conventional systems as illustrated by Megget.
A system of primary and secondary isolator bearings which includes the contact pad embodiment of the present invention may comprise equal numbers of primary and secondary isolator bearings or may be combined in any ratio to such anticipated seismic motions. In a system with equal numbers of primary and secondary isolator bearings which have the same stiffness, the relationship between the horizontal natural frequency of the structure and support system with no slippage of contact pads, F 1 , and with slippage of the contact pads, F 2 , is F 2 =F 1 /2 1/2 . For a system designed for F 1 =0.5 Hz this relationship gives F 2 =0.35 Hz. Similarly, a system designed for F 1 =0.75 Hz gives F 2 =0.53 Hz
The apparatus which engages and disengages an isolator bearing and a mat due to horizontal relative displacement of the upper and lower mats, FIG. 3, may comprise two concentric cylinders with generally vertical axes, 33 and 35, one anchored to a mat as illustrated by the upper mat, 11, and one anchored to an isolator bearing, 13. The axes of the cylinders are coincident when the upper and lower mats are not displaced. The inner radius of one cylinder is larger than the outer radius of the other cylinder by the dimension of the greatest horizontal relative displacement of the upper and lower mats which is tolerated before engagement of the isolator. The cylinders are constructed to be much stiffer than the isolator bearing. Structural steel may be used for construction of the cylinders so that attachment to the mat and isolator bearing may be accomplished by known means. The configuration of FIG. 3 may be reversed so that the smaller diameter cylinder is anchored to the mat and the larger diameter cylinder is anchored to the isolator bearing. Two embodiments of the cylinder embodiment may be implemented. The opposing end surfaces of the cylinders may be separated such that the contact only occurs at the radial surfaces of the cylinders. Relative horizontal displacement of the upper and lower mats causes the mats to move closer to each other. The opposing end surfaces of the concentric cylinders maybe separated when the upper and lower mats are not displaced and such that contact of the end surfaces will occur before engagement of the radial surfaces of the cylinders. The materials and surfaces of the cylinder end surfaces may be specified so that a desired horizontal load is transmitted due to friction of the end surfaces before engagement of the cylinders as described for the contact pad embodiment of the invention.
A system of primary and secondary bearings which includes the cylinder embodiment of the present invention, may comprise equal numbers of primary and secondary isolator bearings which have the same stiffness. The relationship between the horizontal natural frequency of the structure and primary isolator bearings, F 1 , and the horizontal natural frequency of the structure and primary and secondary isolator bearings, F 2 , is F 2 =F 1 2 1/2 . For a system designed for F 1 =0.5 Hz, this relationship gives F 2 =0.71 Hz. Similarly, a system designed for F 1 =0.75 Hz, gives F 2 =1.06 Hz.
FIG. 4 illustrates the response of a structure supported by a system of isolators so that the structure and isolator system has a natural frequency of 0.5 Hz, 41, and the response of a structure supported by primary isolators which from a system with the structure with a natural frequency of 0.5 Hz and secondary isolators embodying the present invention as shown in FIG. 3 which have the same stiffness as the primary isolators, 43. Both responses are the result of motion at 0.5 Hz. As illustrated by that Figure, the acceleration of the structure supported by the single frequency isolator system will become larger for each cycle while the multi-frequency isolator system limits the acceleration. FIG. 4 illustrates a significant difference in acceleration of the structures supported by the two systems after 3 to 4 cycles at the fundamental natural frequency. The results illustrated by FIG. 4 illustrate the additional assurance of low acceleration that is achieved by the present invention.
|
A method and apparatus for isolating a building or other structure from smic vibratory motion which provides increased assurance that large horizontal motion of the structure will not occur than is provided by other isolation systems. Increased assurance that large horizontal motion will not occur is achieved by providing for change of the natural frequency of the support and structure system in response to displacement of the structure beyond a predetermined value. The natural frequency of the support and structure system may be achieved by providing for engaging and disengaging of the structure and some supporting members in response to motion of the supported structure.
| 4
|
BACKGROUND
1. Field of the Invention
This invention relates to lightweight continuous guideway structure for monorail trains.
2. The Prior Art
Elevated monorail trains are becoming a popular, efficient and environmentally clean method of mass transportation, and are potentially a significant factor in energy conservation. In general, tracks for monorail trains are assembled from fabricated cast concrete or rolled steel sections of uniform length, weight, and structural strength. Since the track sections are thus designed for maximum stresses along the entire length of each section, considerable excess weight in the track, which must be supported by columns, is a result. This excess weight is not only expensive but complicates transport, erection and support of the track assembly.
Cast concrete tracks are, in addition, expensive to fabricate and difficult to maintain. Generally, center grooves or troughs are cast in the top surface of concrete tracks to provide surfaces along which guide wheels of the monorail train run. These troughs accumulate water, ice, and debris and must periodically be cleaned.
Fabrication of steel track sections also presents certain problems. Due to the high coefficient of thermal expansion in steel, track sections constructed to fit between preplaced support columns often need modification on site to compensate for temperature induced expansion or contraction of the track. Electrical conduit carrying the power to run the trains is often poorly protected or inaccessible for maintenance in steel tracks as well as in concrete tracks.
In view of the foregoing problems, an improved monorail guide structure is needed which is lightweight yet strong enough to support the loads placed upon it by a monorail train. Such a track should be reinforceable on site at points of varying and increasing stress loads. The on site reinforceability should minimize the on site modification problems encountered in steel track fabrication and material consumption should be significantly reduced. A smooth ride should be derived from the surface of the track. Conduits should be protected and easily accessible for maintenance. Such an improved track assembly is disclosed herein.
BRIEF SUMMARY AND OBJECTS OF THE INVENTION
The present invention involves a guideway structure for monorail trains which is inexpensive, strong, lightweight, and selectively reinforceable on site to obtain proper fit with support columns and adequate structural strength. The track comprises smooth running and control surfaces for a comfortable ride, and a hollow interior for protection and accessibility of electrical conduits. Conduit structure adjacent to the running surfaces are constructed to conduct heat so as to inhibit icing.
It is therefore a primary object of this invention to provide an improved monorail guideway structure and method of manufacture thereof for monorail trains.
It is another object of this invention to provide an improved monorail guideway structure and method of manufacture thereof which has structural integrity and yet has reduced overall mass.
It is another object of this invention to provide an improved monorail guideway structure and method of manufacture thereof which is easily structurally reinforceable on site.
It is another object of this invention to provide an improved monorail guideway structure which presents a smooth riding surface for a monorail train.
Another object of this invention is to provide an improved monorail guideway structure in which electrical conduit is both protected and accessible.
One still further object of this invention is to provide a monorail guideway assembly selected portions of which are heated to inhibit icing of the running surfaces.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective illustration of a typical monorail train situated upon the presently preferred guideway assembly embodiment of the invention, the guideway assembly embodiment being illustrated as supported upon vertical columns.
FIG. 2 is a fragmentary perspective view of the guideway assembly of FIG. 1, portions being broken away to reveal inner parts.
FIG. 3 is a top plan view of a portion of the guideway assembly.
FIG. 4 is a cross-sectional view taken along lines 4--4 of FIG. 2.
FIG. 5 illustrates another presently preferred guideway assembly embodiment particularly illustrating reinforcement structure.
FIG. 6 is a fragmentary perspective illustration of the guideway assembly with portions broken away to reveal interior construction parts of the guideway deicing structure being illustrated schmatically.
FIG. 7 is a perspective illustration of the monorail train of FIG. 1, portions being broken away to illustrate the interior drive structure supported by the monorail guideway.
FIG. 8 is a fragmentary perspective view of still another guideway embodiment of the present invention.
FIGS. 9 and 10 are fragmentary perspective illustrations of other suitable guideway embodiments.
FIG. 11 schematically illustrates alternative structure for deicing the guideway.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is best understood by reference to the figures wherein like parts are designated with like numerals throughout.
FIG. 1 illustrates a preferred monorail guideway assembly embodiment generally designated 10 and mounted upon vertical support columns generally designated 11 and 12. In the illustrated embodiment, the guideway assembly 10 is shown elevated from ground level. The present invention contemplates supporting the guideway assembly 10 at the ground level, above ground level, or spanning ground supporting structure. Columns 11 and 12 typically are of steel wide flange construction having a central body members 74 and 76 and laterally extending flanges 82, 83 and 84, 85, respectively. Conventionally, the columns (e.g. 11 and 12) for supporting the guideway assembly 10 are engineered to be spaced a predetermined distance apart, depending upon site conditions, expected loads and length of track, among other things. A preferred monorail train assembly embodiment generally designated 14, is shown surmounted upon the guideway assembly in a manner hereinafter more particularly described. It is intended that the train 14 be either a plurality of vehicles coupled together as shown in FIG. 1 or a single vehicle as shown in FIG. 7. While not part of the present invention, conventional guidance and driving structure of the train 14 is briefly described and illustrated in FIG. 7 to clarify the importance of features of the guideway assembly, as will hereinafter become more fully apparent.
With continued reference to FIG. 7, bogie drive unit 13 provides power to move train 14 in transport. Portions of the train 14 have been broken away to reveal a schematic representation of the position of the bogie drive within car 15 of train 14. It should be understood that two or more similar bogies 13 would be mounted in the train car 15. Power is derived from electric motor 16, transferred to drive pulley 17 by belt 19, and received by drive wheel 21 through shaft 23. The electric motor 16 is supplied with electrical energy through a power rail (not shown) mounted conveniently upon the guideway assembly 10, the electrical energy being taken from the power rail with a conventional brush assembly (not shown). The drive wheel 21 is constructed to engage guideway assembly 10 at smooth top 37 of running surface 36 to propel train 14. Each bogie unit 13 is supported in the train car 15 by a framework 25 mounted upon the car 15. The framework also carries lateral guide wheels 33 and 35 which provide lateral guidance and stability to train 14.
The structure of the guideway assembly 10 can best be understood by reference to FIGS. 2-6. Referring more particularly to FIGS. 2 and 4, the present embodiment of the guideway assembly 10 is illustrated as having three principal components, namely, running surfaces 36 and 38, beams 18 and 20, and truss 40. Running surfaces 36 and 38 are preferably constructed of plate steel in the form of laterally spaced, essentially continuous, elongated tracks. Running surfaces 36 and 38 are normally coplanar and parallel when the track assembly is linear. Each running surface 36 and 38 provides correspondingly smooth top faces 37 and 39 over which drive wheels, e.g. drive wheel 21 (shown in FIG. 7) traverse. Typically, running surfaces made of 3/8 inch plate steel have proven to be an adequate compromise between strength and weight. The comparatively smooth running surfaces permit the drive wheels of the train 14 to traverse the track assembly quietly and safely.
Running surfaces 36 and 38 are rigidly mounted upon corresponding parallel support members or beams 18 and 20. Beams 18 and 20 are coextensive with running surfaces 36 and 38 and give structural support thereto. Beams 18 and 20 are of hollow, tubular construction. Uniquely the tubular construction contributes remarkable structural strength while simultaneously minimizing overall weight. The beams 18 and 20, in the embodiment illustrated in FIGS. 1-6, are square or rectangular in cross section and, therefore, may be conveniently fabricated according to conventional cold-rolling processes. Alternative constructions of beams 18 and 20 are illustrated in FIGS. 9 and 10, as will be hereinafter more fully described.
As shown best in FIGS. 4 and 5, the flat upper sides 41 and 42 of each beam 18 and 20 are surmounted by the respective running surfaces 36 and 38. Typically the running surfaces are welded or otherwise suitably permanently joined to the beams. It is pointed out that the beams 18 and 20 are inset from the exterior edges of the rails 36 and 38 so as to define rail overhangs 43 and 45. The exterior sides 22 and 24 of the beams 18 and 20 are essentially perpendicular to the plane of the running surfaces 36 and 38. Sides 22 and 24 define the control surfaces over which lateral guide wheels, e.g. guide wheels 33 and 35 (see FIG. 7) traverse. Thus, control surfaces 22 and 24 permit the guide wheels to guide and stabilize the train 14.
The spacing between the beams 18 and 20 is maintained by a plurality of tie bars 26, 28 and 30 which are welded or otherwise suitably secured between beams 18 and 20 at the interior sides 32 and 34. The tie bars e.g. 26, 28 and 30 are of I-beam or wide flange construction and (as shown best in FIG. 6) each is spaced from the next. Although any suitable spacing could be used, in one preferred embodiment, the tie bars 26, 28 and 30 are located approximately 7 feet apart along the length of the track 10.
It is pointed out that the transverse width of the beams 18 and 20 is less than the width of the running surfaces 36 and 38. Thus, in addition to the exterior overhangs 43 and 45, running surfaces 36 and 38 also define interior overhangs 44 and 46 (see especially FIGS. 4 and 5). The interior overhangs 44 and 46 normally engage the upper tie bars 26, 28 and 30 along the margin thereof.
Running surfaces 36 and 38 and the underlying beams 18 and 20, respectively, are structurally supported by truss 40. The truss 40 is shown as rectangular in cross section although circular or other suitable configurations could be used. In the illustrated embodiment, truss 40 has side flanges 50 and 52 mounted rigidly to the flat bottom surfaces 54 and 56 of the corresponding beams 18 and 20. The flanges 50 and 52 are normally oriented essentially in the vertical plane and extend downwardly perpendicular to the bottom surfaces 54 and 56 of the beams 18 and 20. In a preferred embodiment, flanges 50 and 52 were constructed of steel plate.
A bottom wall plate 62 is joined between the flanges 50 and 52 at corresponding bottom ends 58 and 60 in the generally horizontal plane. The bottom wall 62 preferably traverses the length of the track 10. Importantly, it has been found highly desirable to construct bottom wall plate 62 of variable thickness, for example, ranging in thickness between 3/8 inch (approximately 0.95 cm) and one inch (approximately 2.54 cm) or more. The use of variable plate thickness for the bottom wall plate 62 has been found to be advantageous to withstand the compressive stresses which are more pronounced at the locations where the truss 40 is supported upon the columns 11 and 12. The spacing between the thicker portions and thinner portions (see FIG. 6) is selected to correspond approximately to the expected spacing between columns 11 and 12. The thicker portions are formed to traverse about 20% to 30% of the span length of the guideway section.
Alternatively, the structure illustrated best in FIG. 5 could be used to reinforce the bottom plate 62. As shown in FIG. 5, a support framework generally designated 90 has a horizontal plate 92 which is welded or otherwise suitably attached to the inside surfaces 94 and 96 of flanges 50 and 52. Vertical spacer plates 98-101 are secured to the bottom surface 102 of the horizontal plate 92 and to the top surface 103 of the bottom wall plate 62. The location of the framework 90 is selected to coincide with the location of support column 11 or 12. If desired, the framework 90 can be installed in the proper location when the track assembly 10 is on the construction site.
Flanges 50 and 52 cooperate with bottom wall 62 to define a hollow interior within the track assembly 10 below beams 18 and 20 and running surfaces 36 and 38. Thus, in addition to providing a more lightweight assembly, the interior may be used to contain electrical conduit 106 or the like.
Historically, a problem of substantial significance in the assembly of monorail guideways has been to locate reinforced portions of the guideway immediately over the previously spaced columns, e.g. columns 11 and 12. When guideway assemblies are fabricated in a fabrication plant, and thereafter removed to the construction site, the length of the guideway assembly may vary substantially depending upon the temperature at the construction site. For example, the temperature of the guideway assembly can vary as much as 100° F. to 140° F. from point of fabrication to the installation site. It will be appreciated, therefore, that the guideway assembly reinforced at predetermined locations in the fabrication plant and later removed to the construction site may undergo a change of length which would remove the reinforced portions substantially out of reigster with pre-established support column positions.
One of the significant advantages of the present invention is the ability to locate reinforcement structure at the construction site. With continued reference to FIGS. 4, 5 and 6, it will be observed that diaphragm plates 64 and 66 are welded or otherwise suitably secured within the interior of the truss 40 in the generally vertical plane essentially perpendicular to flanges 50 and 52 and bottom wall 62. At the installation site, the diaphragm plates 64 and 66 may be welded in position immediately above the corresponding support columns 11 and 12 where the most significant shear stresses occur.
In assembly, the precise location of engagement of the column to the truss 40 is ascertained at the installation site. Thereafter, the diaphragm 64 is oriented so as to fit between rails 36 and 38. Diaphragm 64 is then positioned into the transverse position illustrated in FIGS. 4-6 at the location of the column 11 or 12. The diaphragm is then welded in place. In the illustrated embodiment, the corners of the diaphragm plate have been removed for ease of on site installation and to permit displacement along the guideway of any moisture accumulating in truss 40. Thus, the location and physical characteristics of each diaphragm plate 64 or 66 can be selected to give the required structural integrity to the track assembly at the location of the support columns 11 or 12.
In order to advantageously utilize the interior of the track assembly 10 for concealing conduit 106 and the like, apertures 108 and 110 are desirably formed in the diaphragms 64 and 66, respectively. A cover plate 48 (FIGS. 2, 4 and 5) is constructed to nest between running surfaces 36 and 38 and normally is welded to surfaces 37 and 39 with specified areas bolted in place rather than welded. The bolted cover plates 48 may be easily removed from time to time by lifting the plate upwards away from the tie bars 26-28, thereby permitting access to the interior of the guideway assembly 10 and the conduit 106 therein.
Normally, the guideway assembly 10 is fabricated at a fabrication plant remote from the installation site. In the course of fabrication, however, diaphragms 64 and 66 are fabricated but not installed within the truss 40. The guideway assembly is then transported in suitable lengths to the installation site where the location of columns 11 and 12 has been predetermined. During installation, the guideway assembly 10 is lifted upon the columns 11 and 12 (see FIGS. 1, 2 and 6). The thicker portions of the bottom plate 62 have been preconstructed so as to be essentially coincident with the expected placement of columns 11 and 12. Alternatively, the reinforcement structure illustrated in FIG. 5 and described above could be utilized to reinforce the bottom plate 62 at the location of the columns 11 and 12.
As soon as the point of engagement of the columns 11 and 12 with the bottom 62 of the guideway assembly 10 has been ascertained, diaphragms 64 and 66 may be secured in place immediately above the corresponding columns. The guideway assembly 10 is then permanently attached to the columns 11 and 12 by securing end plates 78-81 between the columns and corresponding portions of the truss 40. For example, referring particularly to FIGS. 2 and 4, it is observed that the lateral flanges 82 and 83 of the beam 11 are flush with the sides 52 and 50 of the truss 40. Accordingly, end plate 78 can be welded or otherwise suitably rigidly mounted to both the truss and the lateral side 83 to secure the track assembly 10 to the column 11. The end plate 79 is similarly secured to the lateral end 82 and side 52.
Referring now to FIG. 8, another presently preferred guideway assembly generally designated 210 is illustrated. The guideway assembly 210 is similar to guideway assembly 10 in some respect. Running surfaces 36 and 38 are mounted on beams 18 and 20 as heretofore described. Guideway assembly 210 is, however, of "open" construction such that the interior of the truss generally designated 240 is always open at the top. The truss 240 includes sides 250 and 252 which slope inwardly. Sides 250 and 252 are joined to the bottom 262, bottom 262 having a thickness which is variable as described in connection with bottom 62 illustrated in FIGS. 1-6.
The sides 250 and 252 are strengthened and spaced by a plurality of support beams, only one support beam, i.e. being 226 being illustrated in FIG. 8. Support beam 226 is welded or otherwise suitable mounted between the sides 250 and 252 and is preferably configurated as a wide flange structural member. A transverse diaphragm 264 serves substantially the same function as diaphragm 64 and 66 described above. If desired, a cross-brace 227 may be utilized between the support member 226 and the diaphragm 264 to strengthen the construction. Additional cross-braces (not shown) may desirably be used between selected one of the additional support members which are similar to support member 226.
Reference is now made to the guideway assembly embodiment of FIG. 9 which is similar to the guideway assembly embodiment 10 illustrated in FIGS. 1-6 excepting the construction of the running surface and corresponding beams. More particularly, the guideway assembly 310 has a running surface 336 which is a single unitary steel plate superimposed over the sides 50 and 52. The running surface 336 is reinforced to the sides 50 and 52 with corresponding angle iron braces 318 and 320 which are welded or otherwise suitably secured to the corresponding sides 50 and 52. Angle iron 318, when joined to the side 50, cooperates with the side 50 and the running surface 36 to form a hollow structural beam which gives structural integrity to the guideway assembly 310. Angle iron 320 is similarly structurally related to side 52 and running surface 336. Clearly, diaphragm 64 would be configurated to nest around the beams 318 and 320.
While the running surface 336 may be one continuous uninterrupted plate, in the embodiment illustrated in FIG. 9, segments of the plates have been removed to permit access to the interior of the guideway assembly 310 for maintenance, assembly and the like. The opening 337 thus formed is preferably situated around suitable support members 26, 28 and 30 (see FIG. 6) or over a suitable diaphragm 64 such that a cover plate (not shown) may be nested within the opening 337, when desired.
Reference is now made to the guideway assembly embodiment 410 illustrated in FIG. 10. The guideway embodiment 410 is substantially the same as the guideway embodiment 10 illustrated in FIGS. 1-6 except with respect to the relationship between the beams and the running surfaces as will now be described. In the embodiment of FIG. 10, the running surfaces 36 and 38 are mounted directly upon the sides 50 and 52, respectively. The running surfaces 36 and 38 are supported in this position by angle iron braces 418 and 420 which cooperate with the corresponding sides 50 and 52 to form structural beams. The structural beams are hollow and are closed at the top by the running surfaces 36 and 38, respectively. Accordingly, the beams illustrated in FIG. 10 are substantially the same as the beams illustrated in FIG. 9 except that in FIG. 10 the beams are located on the exterior sides of 50 and 52.
The hollow beams 18 illustrated in FIGS. 1-8 and the corresponding structure illustrated in FIGS. 9-11, in addition to the significant benefits of providing structural strength, ease of assembly and comparative light weight also, in accordance with the present invention, function as conduits which facilitate deicing of the steel guideway. More particular, with reference to FIG. 6, a source of heated air represented schematically at 211 is communicated through a conventional air blower 213 to the interior of the beam 18. In actual construction, a resistance heater and plenum chamber may be mounted at or near columns 11 and 12 and heated air forced by a blower 213 through ducts (not shown) to the interior of the beam 18. The hot air forced through the beam 18 maintains the running surfaces 36 and 38 in a deiced condition by conducting the heat directly to the running surfaces.
Greater efficiency in deicing the running surfaces 36 and 38 can be obtained by insulating the interior of the beam 18 on every surface except that contiguous with the running surface 36. In this regard, attention is directed particularly to FIGS. 9 and 10. In FIG. 9, strip insulation 215 is adhered to the inside surface of angle brace 318 and also on a portion of the side wall 50. No insulation is provided underneath the running surface 336. Accordingly, heated air conducted through the beam defined by angle brace 318 will be conducted principally to the running surface 336 thereby maintaining the running surface 336 in a de-iced condition. Alternatively, as shown in FIG. 10, spray foam 217 may be placed in the angle brace 428 prior to assembly and also on a portion of the side wall 52 prior to assembly so as to assure that heat conducted through the beam defined by the angle brace 428 will be directed to the running surface 38.
Another preferred deicing embodiment is illustrated in FIG. 11. The embodiment of FIG. 11 is a modification of the guideway assembly FIG. 9, the modification being primarily in the mode of heating. In FIG. 11, an elongated resistance element 219 traverses the inside of the beam created by angle bracket 318.
Resistance element 219 is situated along the length of the beam defined by angle bracket 318. The insulation 215 is placed as described above so that heat developed by the resistance element 219 will radiate directly to the underside of running surface 336. Because the beam defined by angle bracket 318 opens directly to the underside of running surface 336, the running surface will be heated and maintained in a deiced condition. The resistance element 219 is energized by conventional source of electrical power (not shown) in a manner well known to those skilled in the art.
The guideway assembly described above is aesthetic in appearance and retains a surprising degree of structural integrity thereby providing a safe and effective monorail track. At the same time, the track assembly is comparatively light in weight and simple and inexpensive to install.
The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive and the scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
|
A strong, lightweight monorail guideway assembly for carrying a monorail train vehicle in transport having selectively joined load-bearing rails which are structurally reinforceable on site in relation to support columns holding the track in suspension. Variations in stresses placed on the track are accommodated by the track structure while minimizing overall weight and material consumption. An easily accessible hollow interior provides protection and serviceability for electrical conduit placed therein. A conduit immediately adjacent the running surface may be selectively heated to inhibit icing.
| 4
|
BACKGROUND OF THE INVENTION
The invention pertains to oil primary controls for oil-fired heating systems, and in particular, to an improved lockout mode control for an oil primary.
Oil heating systems employ a control, referred to generally as an oil primary, which controls the delivery of a fuel oil/air mixture and ignition spark to the combustion chamber of the oil burner. Such systems also use a combustion or flame detector, usually a photosensor, to detect when combustion has successfully begun. This is necessary because, for a number of reasons, it is possible that an attempted ignition may not result in combustion. Such factors include a complete or partial loss of fuel or air, loss of ignition source, or clogged or failed component in the oil burner. One function of the oil primary is to interrupt the flow of oil to the combustion chamber if successful combustion is not detected within a certain time period, which is often referred to as the lockout time or the TFI (trial for ignition) time. If combustion is not confirmed within the lockout time, the oil primary shuts off the flow of oil and air, and igniter spark, and places the system in lockout mode. In lockout mode, the system will no longer respond to a call for heat from a thermostat, which it would do, of course, in a normal mode of operation.
Normally, manual intervention is required to take the system out of lockout mode, either by a service person or by the homeowner/user. A reset button is provided in association with the oil primary to allow user activation of a reset input. Alternatively, it is envisioned that suitable intervention may be provided remotely via a communication link. Since it is possible that the problem which caused the lockout may self-correct, the reset gives the opportunity of successfully starting the oil heating system again. If the restart attempt is successful, it avoids the inconvenience and expense of a service call, and in the worst case, may avoid the prospect of frozen or damaged pipes in the home.
However, if the root problem which caused the lockout has not cleared or is not fixed, a reset will cause another attempted oil ignition cycle, and result in a further lockout. In many instances a homeowner may continue to push the reset button, in an attempt to restart the system. In cases where the system does not clear or correct itself, this will result in flooding of the combustion chamber with unignited oil. This might create a hazard, and may require a service person to come to the site and clean out the combustion chamber, which is a time consuming and costly process. Because of these problems, prior oil primaries, such as the Model R7184 Interrupted Electronic Oil Primary commercially available from Honeywell International Inc., have generally provided a limitation on the reset function, for example, limiting it to three times without successful ignition, after which the system remains in lockout and a service person must be called. This approach has the disadvantage, however, that if service is not readily available during cold periods, occupants may not be able to continue living in the space to be heated, and under certain. circumstances, damage may result due to freezing water pipes.
SUMMARY OF THE INVENTION
The present invention improves on the lockout control of the prior art by allowing flexibility and a greater number of user resets and ignition retries in the event of lockout, while still minimizing the unwanted accumulation of oil in the combustion chamber.
According to the present invention, if lockout occurs due to failure of combustion to take place, the oil primary is placed in a restricted mode of operation in which a limited number of reset activations may be attempted. If they are unsuccessful, a waiting time interval is imposed between successive attempts, and optionally the lockout time is also reduced for such subsequent attempts, to minimize flooding. Normal operation is returned once a successful combustion cycle has been achieved.
According to the present invention, there is provided an oil primary for initiating and controlling oil combustion in an oil heating system, normally in response to a thermostat or Aquastat® signal indicating a call for heat. An ignition detector, such as a Model C554A Cadmium Sulfide Flame Detector commercially available from Honeywell International Inc., provides an indication to the oil primary of whether or not combustion has been achieved in the oil heating system. If combustion is not detected within the lockout time period, oil is shut off and the system is placed in lockout mode. A user reset is provided for receiving user reset inputs, which release the lockout mode to permit the oil primary to retry combustion. In the event of a number of such retries without successful combustion, the system imposes a waiting interval before permitting a further retry in response to a user reset activation.
According to another feature of the invention, after a number of unsuccessful retries, the lockout time period is reduced, to reduce the amount of oil introduced into the combustion chamber on each retry, to further reduce the possibility of oil flooding.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawing,
FIG. 1 is a schematic diagram of a control system including an oil primary for an oil burner, of the type to which the present invention may be advantageously applied; and
FIG. 2 is a flowchart of restricted lockout control according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, an oil burner appliance is shown, including a combustion chamber identified by reference numeral 10 . It receives fuel oil from a line 11 from a fuel oil source (not shown), through a pump 12 , line 13 , valve 14 and line 15 . This is representative of certain oil burner appliance designs. Other designs do not include a valve corresponding to valve 14 .
An oil primary 20 is provided for controlling the ignition and combustion process. Oil primary 20 receives signals on control line 21 when there is a call for heat to the system. Typically, this is provided by a thermostat or Aquastat® which is indicated at reference number 22 . Alternatively, other types of devices could be used for calling for heat, such as a user-activated switch, a timer-activated switch, or the like.
An igniter 30 is provided, which may be part of the oil primary, or a separate device controlled by the oil primary, as is the case in FIG. 1 . Igniter 30 is connected at lead 31 to the oil burner appliance, to provide an ignition spark to initiate a combustion cycle. Igniter 30 operates under control of oil primary 20 , via the indicated control line 23 . Oil primary 20 also controls a motor 16 , which drives pump 12 and a blower 17 , as indicated, via control line 24 . An ignition detector 18 is also provided, positioned to view the flame area within combustion chamber 10 , and connected via control line 25 to oil primary 20 . Ignition detector 18 may be a Honeywell C554A Cadmium Sulfide Flame Detector.
In normal operation for a heating cycle, oil primary 20 receives a signal, for example, from thermostat or Aquastat® 22 , calling for heat. In the system shown in FIG. 1, oil primary 20 first energizes igniter 30 to initiate ignition spark, and then energizes motor 16 , which activates pump 12 and blower 17 . Thereafter, oil primary 20 supplies a signal over a control line 19 to open valve 14 , which introduces fuel oil into the air stream produced by blower 17 to supply oil mist to combustion chamber 10 . During a lockout time interval, the oil primary checks for confirmation from ignition detector 18 on control line 25 , that acceptable combustion has been achieved. If so, the burn continues through the normal combustion cycle.
However, if during the lockout time the successful establishment of combustion has not been achieved, the oil primary goes into lockout mode. In this mode igniter 30 , motor 16 and valve 14 are de-energized, thereby terminating the supply of spark, air and oil mist. The oil primary, while locked out, and will not respond to further signals calling for heat, without a manual reset intervention.
As indicated in FIG. 1, oil primary 20 includes a user-actuatable reset input, commonly in the form of a reset button 26 connected to a switch. Activation of reset button 26 takes the oil primary out of lockout mode, permitting a retry of a combustion cycle. If successful, the combustion cycle proceeds normally. If, however, the retry is not successful, which will most likely be the case if the root cause of the combustion failure has not cleared or been corrected, another lockout will result. The user, typically a homeowner, might activate reset button 26 a number of times trying to reestablish operation of the heating unit. In existing systems, this may cause a significant amount of oil to accumulate in the combustion area, degrading it and ultimately requiring a maintenance service call for cleaning.
Because of this, some prior art oil primaries have limited the number of resets to a small number, typically three retries. If no successful combustion cycle takes place during the three retries, the system remains locked out, necessitating a service call.
The present invention improves upon the prior art by providing a lockout with a restricted user reset capability, which provides the opportunity to restart the system if possible, but which limits the amount of oil accumulation and subsequent degradation of the combustion chamber, if unsuccessful.
Oil primaries may be implemented in different technologies, including relays, discrete or integrated electronic logic, programmed microcontrollers, or various combinations thereof. Likewise, the lockout-reset control of the present invention can be implemented in any of those or other known technologies.
The embodiment of the invention disclosed herein with reference to FIG. 2 is in the form of software routines to work in conjunction with a microcontroller-based oil primary. The basic operating steps of the oil primary described above are generally known, and are not covered in FIG. 2 . FIG. 2 represents a flowchart of the restricted lockout control for the oil primary.
The program of FIG. 2 is shown as beginning at flow arrow 50 , which would represent a branch from the main control of the oil primary (not shown) at the beginning of a combustion cycle. Step 51 is the trial for ignition initiation. At step 52 , the system tests whether the trial for ignition was successful. A successful test is when the photocell or flame detector confirms that combustion has been established within the lockout time. Typically, the default or factory setting for lockout time would be 45 seconds, although other times for the lockout could easily be selected. In the event of a successful test, control branches to flow path 53 to step 54 . At this step, the trial counter (discussed below) is reset to zero, the lockout time is reset to the default or factory settings, and normal operation is continued for a combustion cycle. At this point, the control exits the loop of FIG. 2, and would return to the main control (not shown) of the oil primary.
If the trial for ignition was not successful at decision block 52 , control passes through path 55 to step 56 . At this point, an increment is added to a trial counter within the programmed microprocessor, which is used to keep track of the number of combustion retries. Concurrently, the control enters the lockout state, which requires manual reset before the ignition process can be reinitiated. A wait timer, used in step 69 below, may also be set at this point. The trial counter and lockout status are stored in a nonvolatile memory associated with the microcontroller for the oil primary. The reason for using nonvolatile memory is so that in the event there has been a power outage, or the user disconnects power to the oil primary and then reconnects it, the lockout status and count of number of trials will be preserved.
From step 56 , control passes via path 57 to a decision block 60 . This block loops back on path 61 waiting to detect a user reset activation. When the user pushes the reset button or otherwise provides a reset activation, control passes to path 62 . Path 62 leads to decision block 63 , which checks the trial counter to determine the number of trials since the start of the current non-combustion situation. If this is a first trial, control passes via path 64 . If there are two trials, control passes via path 65 , and if there have been more than two trials, control passes via path 66 .
In the event of a first trial, path 64 takes control to step 70 , which causes clearing of the lockout status from nonvolatile memory, but not clearing of the count in the trial counter. Control then proceeds via path 71 back to the start of the trial for ignition. Thus, a retry is enabled. If the retry is successful, as detected at decision block 52 , control will pass out block 54 , resetting the trial counter to zero as it will no longer be needed. If, however, the trial was not successful, control passes via path 55 to increment the trial counter, and if the reset button is pressed, eventually leads to decision block 63 again.
If there have been two trials, meaning two attempts, the initial attempt and one reset-retry, control will pass to step 67 . At this point, the lockout time is reduced to a shorter interval than the original. For example, if the default or factory setting is 30 seconds, the reduced lockout time may be shortened to, for example, 10 seconds. This is to further reduce the amount of oil accumulation in the event of a further unsuccessful retry. Control then passes via path 68 to block 70 and so on, as previously described for a further retry.
If at decision block 63 , the number of trials has exceeded two, control passes to decision block 69 . At decision block 69 , the wait timer is queried to determine whether the wait time has expired since the start of the last retry. The wait time may be set at, for example, 1 hour, although other longer or shorter times may also be used. If the wait time has not expired, control loops back via path 73 to await a reset actuation at step 60 . However, as long as the wait time has not expired, the control will be stalled in the loop including decision block 69 , effectively preventing a further retry.
If the wait time has expired, control passes via path 72 to block 67 , and eventually back to trial for ignition block 51 , as previously described.
The operation of the embodiment of FIG. 2 is illustrated in the example shown in the following table. Six trials are shown in the example, the initial thermostat-initiated ignition trial, and five user reset-initiated samples. Note that after trial number 2, the lockout time is reduced from 30 seconds to 10 seconds, which still gives sufficient time to confirm successful combustion, but which if unsuccessful, reduces the total amount of oil accumulation. Note that after trial number 3, a one hour wait is imposed before each successive user-initiated retry, thus further limiting the oil accumulation if the retries are unsuccessful. In this example, six trials were attempted with a total accumulation time of 100 seconds of oil flow, spread out over a period of three hours. By comparison, a prior art lockout control as described above would permit three tries, or 135 seconds of oil, which might all happen within just a few minutes.
Total Oil
Trial
Trial for Ignition Time
Accumulation Time
#1
30 seconds
30 seconds
#2
30 seconds
60 seconds
#3
10 seconds
70 seconds
One Hour Wait
#4
10 seconds
80 seconds
One Hour Wait
#5
10 seconds
90 seconds
One Hour Wait
#6
10 seconds
100 seconds
It will thus be appreciated that the restricted lockout control of the present invention reduces the amount of accumulated oil in the case of a nonfunctioning burner, while at the same time allowing or permitting restart of the burner should the cause of the shutdown correct or clear itself.
It will be seen from the above that the present invention provides an improved oil primary lockout control and method of operation for allowing a reasonable number of user resets and ignition retries in the event of lockout, while still minimizing the unwanted accumulation of oil in the combustion chamber. While specific embodiments of the invention have been described, it will be appreciated that the invention is not limited to those specific applications, and that many variations are possible within the scope of the invention.
|
Improved lockout control in oil primary controllers for oil heating systems which allows a reasonable number of user resets and ignition retries in the event of lockout, while minimizing the unwanted accumulation of oil in the combustion chamber of the heating system. When the oil primary goes into lockout mode due to failure of combustion to take place, the oil primary is placed in a restricted mode of operation in which a limited number of reset activations and combustion retries may be attempted. If they are unsuccessful, a waiting time interval is then imposed between further successive attempts. The lockout or trial for ignition time may also be reduced for subsequent attempts, to minimize flooding. Normal operation is returned once a successful combustion cycle has been achieved.
| 5
|
FIELD OF THE INVENTION
[0001] The present invention relates to an apparatus and system for controlling a clutch, more specifically such an apparatus and system that operates in both a manual and an automatic mode.
BACKGROUND OF THE INVENTION
[0002] The characteristics of speed, torque (turning or twisting force), and power (rate or speed at which work is performed) for a typical internal combustion engine in a motor vehicle such as a motorcycle or a car usually do not match the requirements of the final propulsion component. For example, the range of output of the engine in a motorcycle does not match the range of requirements of the wheels in contact with the road surface. A clutch, disengageably connecting the engine to the transmission, provides the means to apply and remove engine torque to the transmission's input drive shaft.
[0003] A typical hydraulic clutch arrangement includes a clutch hand lever placed at the handlebars which actuates a master cylinder. The master cylinder is fluidly coupled to a slave cylinder mounted on or near the engine casing. The slave cylinder in turn actuates a push rod or alternatively a clutch lever which forcibly disengages the clutch. A hydraulic fluid reservoir typically attached at or near the master cylinder and becomes isolated from the system during master cylinder actuation. Spring biasing, integral to the clutch, biases the slave cylinder and master cylinder at rest so that the fluid reservoir may provide relief against environmental changes.
[0004] A typical hydraulic clutch is disengaged by depressing the clutch lever which compresses the master cylinder, generating pressure that actuates the slave cylinder, and transmits force along the push rod through to a pressure plate, lifting the pressure plate away from the clutch housing, relieving pressure between the friction and friction bearing elements, resulting in the disengagement of the engine from the transmission. This approach has a number of disadvantages, including the physical effort required to disengage the clutch lever which may lead to rider fatigue. Additionally, careful operation of the clutch lever in conjunction with the gear selector requires a level of concentration that may distract the rider and lead to loss of control. Also, mechanical clearances coupled with non-linear hydraulic effects limit clutch feedback and response, which in turn retards the rider's ability to finely control the clutch.
[0005] Many modern vehicles may incorporate a so-called automatic clutch instead of a manually-actuated clutch, such as the one described above, which automatically engages and disengages a friction clutch with some form of actuator.
[0006] The automatic clutch suffers from a number of drawbacks. If the automatic clutch fails, the vehicle is inoperable. There is no fail-safe mode of operation that permits the continued operation of the vehicle under those conditions. Additionally, the control system for automatics is not intuitive and may not respond to various driving situations when specific modes of clutch operation are desired. For example, the transmission may shift at a time when the rider of the vehicle does not expect it, which may lead to a loss of control.
[0007] In response, the so-called semi-automatic clutch was developed, which included both a manually-actuated clutch in addition to an automatic clutch. The known semi-automatic clutch has a problem when switching between the manual and the automatic modes of operation. During this switching process, when one mode is switched to the other mode during the disconnection of the clutch, the clutch may rapidly be engaged, which may cause unexpected acceleration and a jarring sensation.
[0008] In U.S. Pat. No. 6,170,624, a system is proposed to address connection shock. This application discloses a semi-automatic clutch that may prevent connection shock from occurring during the transfer from one mode to another, but only after the connection of the clutch is finished.
[0009] A drawback of the current state of the art in semi-automatic clutches is that there is a limitation on when the switch may occur between a manual mode and an automatic mode of operation. This limitation on timing prevents the operator from having the complete freedom to engage the manual override of the clutch at any time during operation of the vehicle.
[0010] Another drawback of the current state of the art is the complexity of the current semi-automatic systems. In particular, many alternative systems use a number of isolated hydraulic circuits, which require a separate reservoir for each hydraulic circuit. This complexity may increase the chances of mechanical failure during the prolonged operation that modern vehicles routinely endure, and increase the difficulty and cost of regular maintenance, and repair in the event of a failure.
[0011] There is a need to provide a way of switching between operating modes not only when the clutch is engaged, but at any time while the vehicle is operating, smoothly without shock, using a device that contains only one hydraulic circuit and reservoir.
SUMMARY OF THE INVENTION
[0012] An electro-hydraulic control system for a vehicle clutch, comprising:
a sub-assembly, comprising:
a manual hydraulic pressure source, an automatic hydraulic pressure source, and a slave cylinder that actuates a clutch,
with both the automatic hydraulic pressure source and the manual hydraulic pressure source hydraulically feeding the slave cylinder; and a reservoir; and an isolation valve, connected hydraulically with the reservoir;
wherein the isolation valve isolates the reservoir from the sub-assembly during the actuation of either the manual hydraulic pressure source or the automatic hydraulic pressure source.
[0020] A controller, connected energetically to the isolation valve, the manual hydraulic pressure source, and the automatic hydraulic pressure source, actuates the isolation valve prior to the actuation of either the manual hydraulic pressure source or the automatic hydraulic pressure source so that the reservoir becomes isolated from the sub-assembly.
[0021] The controller, upon receiving a signal from the manual hydraulic pressure source, freezes the flow from the automatic hydraulic pressure source. Alternatively, the controller, upon receiving a signal from the manual hydraulic pressure source, dynamically controls the flow from the automatic hydraulic pressure source so as to transmit mechanical feedback through the manual hydraulic pressure source to a human operator.
[0022] An electro-hydraulic control system for a vehicle clutch, comprising:
a first sub-assembly, comprising:
an automatic hydraulic pressure source, and a slave cylinder that actuates a clutch;
a second sub-assembly comprising:
a manual hydraulic pressure source, a reservoir, connected hydraulically with the manual hydraulic pressure source, and a valve interposed between the manual hydraulic pressure source and the reservoir, the valve isolating the reservoir when the manual clutch cylinder is actuated; and
an isolation valve, connected hydraulically with the first sub-assembly and the second sub-assembly;
wherein both the automatic hydraulic pressure source and the isolation valve connect hydraulically to the slave cylinder, and the isolation valve isolates the first sub-assembly from the second sub-assembly during the actuation of the automatic hydraulic pressure source.
[0031] The manual hydraulic pressure source comprising a manual clutch cylinder connected mechanically to a clutch lever, the clutch lever being moved using direct human effort, wherein the reservoir is proximate the manual clutch cylinder and connected hydraulically with the manual clutch cylinder, and the valve is interposed between the manual clutch cylinder and a reservoir, the valve isolating the reservoir when the manual clutch cylinder is actuated.
[0032] A controller, connected energetically to the isolation valve, the manual hydraulic pressure source, and the automatic hydraulic pressure source, actuates the isolation valve prior to the actuation of the automatic hydraulic pressure source so that the reservoir becomes isolated from the sub-assembly.
[0033] The controller, upon receiving a signal from the manual hydraulic pressure source, freezes the flow from the automatic hydraulic pressure source. Alternatively, the controller, upon receiving a signal from the manual hydraulic pressure source, dynamically controls the flow from the automatic hydraulic pressure source so as to permit the depression of the clutch lever.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Embodiments of the invention will be described by way of example and with reference to the drawings in which:
[0035] FIG. 1 is a schematic view of the invention;
[0036] FIG. 2 is a cross-sectional view of an embodiment of the invention showing the slave cylinder and valve means, when the clutch is engaged;
[0037] FIG. 3 is a cross-sectional view of an embodiment of the invention showing the slave cylinder and valve means, when the clutch is disengaged by the automatic hydraulic pressure source; and
[0038] FIG. 4 is a cross-sectional view of an embodiment of the invention showing the slave cylinder and valve means, when the clutch is disengaged by the manual hydraulic pressure source.
DETAILED DESCRIPTION OF THE INVENTION
[0039] FIG. 1 is one embodiment of the invention. FIG. 2 is a cross-sectional view of a second and preferred embodiment of the invention, at rest. FIG. 3 shows the embodiment in FIG. 2 when the primary hydraulic pressure source is actuated. FIG. 4 shows the embodiment in FIG. 2 when the manual hydraulic pressure source (the manual override) is actuated. The basic mechanism involves connecting a manual hydraulic pressure source 100 together with an automatic hydraulic pressure source 113 into a slave cylinder 115 so that when either pressure source is actuated, the clutch 130 is disengaged.
[0040] The manual hydraulic pressure source 100 and the automatic hydraulic pressure source 113 may be connected to a tee connection 111 through a manual hydraulic circuit line 109 and an automatic hydraulic circuit line 112 , respectively. From the tee connection 111 , the flow from either pressure source would travel into the slave cylinder 115 , and force a piston 116 to travel. The movement of the piston 116 in turn places pressure on a push rod 121 that travels through the engine casing 114 to a friction clutch 130 . A master cylinder piston 101 , connected to the clutch lever 102 , compresses the fluid in a master cylinder within the manual hydraulic pressure source 100 .
[0041] An isolation valve 110 may be interposed between the manual hydraulic pressure source 100 and the tee connection 111 so as to ensure that when the automatic hydraulic pressure source 113 is activated, there may not be backflow along the manual hydraulic circuit line 109 into the manual hydraulic pressure source 100 .
[0042] A control system (not shown) may be connected to the manual hydraulic pressure source 100 through a clutch switch 108 or other similar sensor so that the control system is signaled upon the actuation of the manual hydraulic pressure source 100 by a clutch lever 102 . The control system may also be connected to the slave cylinder 115 through a position sensor 120 , which measures the position of the piston 116 within the slave cylinder 115 . The control system may also be connected to the isolation valve 110 to ensure the proper and timely activation of the isolation valve 110 during the actuation of the automatic hydraulic pressure source 113 , and the deactivation of the isolation valve 110 when the pressure from the manual hydraulic pressure source 100 exceeds that present at the tee connection 111 , and whenever neither pressure source 100 113 is actuated and the system is at rest. The control system may be connected to the automatic hydraulic pressure source 113 to determine its state at any given time.
[0043] A reservoir 103 may be located at the manual hydraulic pressure source 100 so that when the master cylinder piston 101 travels past the reservoir tie-in point 107 during actuation, the master cylinder piston 101 seals off the reservoir from the rest of the system, preventing backflow to the reservoir 103 during an override event.
[0044] The connection of the hydraulic lines 112 109 to the various hydraulic components 100 115 113 may be made using banjo fittings 106 118 , which may be sealed in place using crush washers 104 105 and bolts.
[0045] The slave cylinder 115 may be affixed to the engine casing 114 . The slave cylinder 115 contains the piston 116 . The piston 116 may be biased by a biasing spring 117 when the system is at rest. The slave cylinder 115 may incorporate a bleed screw 119 , which allows the system to be easily bled of trapped air bubbles during maintenance.
[0046] During automatic operation of the clutch, upon determining that the clutch needs to be disengaged, the controller first activates the isolation valve 110 , so as to prevent backflow into the reservoir 103 and the manual hydraulic pressure source 100 . The controller next actuates the automatic hydraulic pressure source 113 , which delivers pressure to the slave cylinder 115 and disengages the clutch 130 . Once shifting of the transmission is completed, the clutch 130 may be reengaged by relaxing the pressure from the automatic hydraulic pressure source 113 , which allows the piston 116 to return to a neutral position. Isolation of the manual hydraulic pressure source may no longer be required after the piston 116 returns to a neutral position and the automatic hydraulic pressure source 113 stops providing pressure, so the isolation valve 110 deactivates. This permits the system to equilibrate after each disengagement of the clutch, making it more tolerant of environmental changes and small leaks.
[0047] During manual operation of the clutch, the operator depresses the clutch lever 102 , which both slides the master cylinder piston 101 and activates the clutch switch 108 . The master cylinder piston 101 both isolates the reservoir 103 and delivers pressure to the slave cylinder 115 . The isolation valve 110 remains deactivated throughout this operation, and the automatic hydraulic pressure source 113 remains static. Pressure on the piston 116 disengages the clutch 130 . Once shifting of the transmission is completed, the clutch 130 may be reengaged by relaxing the clutch lever 107 , which allows the piston 116 to return to a neutral position.
[0048] During a manual override of an automatic shifting event, the isolation valve 110 may be activated, followed by actuation of the automatic hydraulic pressure source 113 , of the normal automatic operation described above. The operator may then depress the clutch lever 102 to override the clutch. Pressure may build in the manual hydraulic circuit line 109 as the operator squeezes, until the pressure in the manual hydraulic circuit line 109 exceeds that of the automatic hydraulic circuit line 112 , triggering an override event. During an override event, the check valve contained within the isolation valve 110 may open, permitting the flow of fluid from the manual hydraulic pressure source 100 into both the slave cylinder 115 and the automatic hydraulic pressure source 113 . Sensors, such as the clutch switch 108 , may signal the controller that there is an override event in progress. The controller may freeze the automatic hydraulic pressure source 113 , or alternatively may allow the automatic hydraulic pressure source 113 to absorb a volume of fluid at a rate equal to that being displaced by the master cylinder piston 101 as the clutch lever 102 is depressed. The later option is preferable, as it may provide the operator with feedback though the clutch lever 102 , and may smooth the transition between the automatic and manual states.
[0049] The preferred embodiment shown in FIG. 2 integrates a number of the elements shown in FIG. 1 into an assembly integral to the housing of the slave cylinder 200 . Specifically, the tee connection 111 and the isolation valve 110 may be incorporated into the slave cylinder 200 to make the system easier to install and maintain. The isolation valve 110 has taken on the form of a pilot operated—poppet type solenoid valve.
[0050] A manual pressure source (not shown) may be connected through the manual hydraulic circuit line 207 to the slave cylinder 200 . This manual pressure source could take the form of the manual hydraulic pressure source 100 or a variation thereof such as any hand or foot operated lever or button assembly, or any mechanically operated pressure source that when actuated isolates the system reservoir (not shown).
[0051] An automatic hydraulic pressure source (not shown) may be connected through the automatic hydraulic circuit line 206 to the slave cylinder 200 . Both circuit lines may be connected to the slave cylinder using a banjo fitting 216 and crush washers 212 213 as shown in FIG. 2 .
[0052] The isolation valve 203 may comprise a valve body 217 , a solenoid coil 219 , a solenoid armature 220 connected to a plunger 218 , and a poppet 208 . The poppet may contain orifices that act in conjunction with the plunger 218 to form a pilot valve 209 within the poppet 208 . The pilot valve 209 may be biased with a biasing spring 210 to be open when the system is at rest, as shown in FIG. 2 . On assembly, the isolation valve 203 may be passed though the banjo fitting 221 connected to the automatic hydraulic circuit line 206 , the banjo fitting 221 having crush washers 222 223 on either side, through the slave cylinder 200 housing, and through the banjo fitting 216 connected to the manual hydraulic circuit line 207 , the banjo fitting 213 having crush washers 211 212 on either side. A capping nut 215 may be used to fix the isolation valve 203 and the banjo fittings 216 in place. A bleed screw 214 may be included to allow trapped gas bubbles to escape during maintenance or repair of the system. A circuit isolation seal 211 may be placed on the outside of the isolation valve 203 so that there is no leakage between the circuit lines 207 206 along the outside of the valve.
[0053] The slave cylinder 200 may be affixed to the engine casing 204 . The slave cylinder 200 contains the piston 201 . The piston 201 may be biased by a biasing spring 202 when the system is at rest. During actuation of either or both of the pressure sources, the piston 201 may travel, putting pressure on the push rod 205 , and disengaging the clutch.
[0054] When the system is at rest, and neither pressure source is actuated, the poppet 208 and the plunger 218 may be positioned as shown in FIG. 2 . The biasing spring 210 may hold the pilot valve 209 open. The solenoid coil 219 may not be energized, the solenoid armature 220 may be in a neutral position, and the plunger 218 may be in a retracted position relative to the poppet 208 , so the pilot valve 209 may be in an open position. Fluid in all pathways may be relaxed.
[0055] In FIG. 3 , the automatic hydraulic pressure source is actuated. The solenoid coil 219 may be energized, the solenoid armature 220 may be in a forward position, and the plunger 218 may be in an engaged position relative to the poppet 208 , so the pilot valve 209 may be in a closed position. The poppet 208 may be held closed by the force from the energized solenoid though the plunger 218 and pilot valve 209 combined with the pressure differential across the poppet 208 . Fluid may be permitted to flow from the automatic hydraulic pressure source along the automatic hydraulic circuit line 206 around the isolation valve 203 and into the slave cylinder 200 . The piston 201 may move under pressure as the fluid flows into the slave cylinder 200 .
[0056] In FIG. 4 , the manual hydraulic pressure source is actuated while the automatic hydraulic pressure source is actuated. Pressure may build up in the manual hydraulic circuit line 207 . When the pressure in the manual hydraulic circuit line 207 exceeds that in the automatic hydraulic circuit line 206 and the pressure provided by the energized solenoid though the plunger 218 and though the pilot valve 209 , the poppet 208 , pilot valve 209 , and the plunger 218 may all be forced downwards, permitting fluid to flow from the manual hydraulic circuit line 207 though the isolation valve 203 into both the automatic hydraulic circuit line 206 and the slave cylinder 200 . This flow of fluid may maintain pressure on the piston 201 , keeping the clutch disengaged. The automatic hydraulic pressure source may absorb a volume of fluid at a rate equal to that being displaced by manual hydraulic pressure source, providing the operator with feedback though the clutch lever 102 , and smoothing the transition between the automatic and manual states.
[0057] A digital controller may be used, reading in data from sensor inputs such as switches and position sensors, and writing data to actuators such as relays and solenoids. An analog circuit may be used to support the digital controller. Position sensors, pressure transducers, or switches may be used to detect the states of the valves and cylinders, including to detect manual operation during normal operation, and may be used by the controller to disable any automatic clutch operation except during engine damaging conditions.
[0058] The isolation valve 110 may be replaced with a simple on/off valve (not shown) that blocks flow during the activation of the automatic hydraulic force 100 . Such a variant may require precise timing from the controller.
[0059] In one embodiment, the isolation valve and the reservoir are hydraulically connected with the hydraulic circuit formed between the manual hydraulic pressure source, the automatic hydraulic pressure source, and the slave cylinder, instead having the manual hydraulic pressure source interposed between the isolation valve and the reservoir, as described above.
[0060] It will be appreciated that the above description relates to the preferred embodiments by way of example only. Many variations on the system and method for delivering the invention without departing from the spirit of same will be clear to those knowledgeable in the field, and such variations are within the scope of the invention as described and claimed, whether or not expressly described.
|
An electro-hydraulic control system for a vehicle clutch, that operates in both a manual and an automatic mode. The invention provides a way of switching between operating modes not only when the clutch is engaged, but at any time while the vehicle is operating, smoothly and without shock, using a system that contains only one hydraulic circuit and reservoir.
| 5
|
FIELD OF THE INVENTION
[0001] This disclosure relates generally to gaming devices, and more particularly to gaming devices with unlockable features.
BACKGROUND
[0002] Playing games of chance is a popular recreational activity. There are many types of games of chance including table games where players wager against a live dealer such as blackjack, Pai Gow, roulette, Baccarat. Other types of games of chance are offered as automated machines. Examples include slots, poker, bingo, etc. Still other types of games of chance allow players to wager against one another, such as a poker table. In return for a wager, games of chance generate randomly determined outcomes, some of which result in a winning event. Games of chance are often played with wagers having financial value but some games of chance are played with points or other freely available currency having no fiscal worth.
[0003] Games of chance may be played in casinos, or at home using electronic devices or mechanical equipment. Gambling via Internet, whether for fun or for money, is also a popular activity.
[0004] Automated gaming machines typically have a single game environment. For example, gaming machines will have a specific color scheme, specific symbols, etc; in other words, a specific ‘look and feel’.
[0005] One of the problems with conventional automated gaming machines is that the player may become bored with the game environment on a certain gaming machine and decide to stop playing for that reason. Further, there is no incentive for the player to continue to play on any certain gaming machine because the game environment will never change. Consequently, a need remains for a mechanism by which the game environment can be changed over time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1A is a functional block diagram that illustrates a gaming device according to embodiments of the invention.
[0007] FIG. 1B is an isometric view of the gaming device illustrated in FIG. 1A .
[0008] FIGS. 2A , 2 B, and 2 C are detail diagrams of exemplary types of gaming devices according to embodiments of the invention.
[0009] FIG. 3 is a functional block diagram of networked gaming devices according to embodiments of the invention.
[0010] FIG. 4 illustrates an example video slot machine according to some embodiments of the invention.
[0011] FIG. 5 illustrates an unlockable feature management screen according to some embodiments of the invention.
[0012] FIG. 6 illustrates an unlockable feature acceptance screen according to some embodiments of the invention.
[0013] FIG. 7 illustrates a conditional unlockable feature acceptance screen according to some embodiments of the invention.
DETAILED DESCRIPTION
[0014] FIGS. 1A and 1B illustrate example gaming devices according to embodiments of the invention.
[0015] Referring to FIGS. 1A and 1B , a gaming device 10 is an electronic gaming machine. Although an electronic gaming machine or “slot” machine is illustrated, various other types of devices may be used to wager monetarily based credits on a game of chance in accordance with principles of the invention. The term “electronic gaming device” is meant to include various devices such as electro-mechanical spinning-reel type slot machines, video slot machines, and video poker machines, for instance. Other gaming devices may include computer-based gaming machines, wireless gaming devices, multi-player gaming stations, modified personal electronic gaming devices (such as cell phones), personal computers, server-based gaming terminals, and other similar devices. Although embodiments of the invention will work with all of the gaming types mentioned, for ease of illustration the present embodiments will be described in reference to the electronic gaming machine 10 shown in FIGS. 1A and 1B .
[0016] The gaming device 10 includes a cabinet 15 housing components to operate the gaming device 10 . The cabinet 15 may include a gaming display 20 , a base portion 13 , a top box 18 , and a player interface panel 30 . The gaming display 20 may include mechanical spinning reels ( FIG. 2A ), a video display ( FIGS. 2B and 2C ), or a combination of both spinning reels and a video display (not shown). The gaming cabinet 15 may also include a credit meter 27 and a coin-in or bet meter 28 . The credit meter 27 may indicate the total number of credits remaining on the gaming device 10 that are eligible to be wagered. In some embodiments, the credit meter 27 may reflect a monetary unit, such as dollars. However, it is often preferable to have the credit meter 27 reflect a number of ‘credits,’ rather than a monetary unit. The bet meter 28 may indicate the amount of credits to be wagered on a particular game. Thus, for each game, the player transfers the amount that he or she wants to wager from the credit meter 27 to the bet meter 28 . In some embodiments, various other meters may be present, such as meters reflecting amounts won, amounts paid, or the like. In embodiments where the gaming display 20 is a video monitor, the information indicated on the credit meters may be shown on the gaming display itself 20 ( FIG. 2B ).
[0017] The base portion 13 may include a lighted panel 14 , a coin return (not shown), and a gaming handle 12 operable on a partially rotating pivot joint 11 . The game handle 12 is traditionally included on mechanical spinning-reel games, where the handle may be pulled toward a player to initiate the spinning of reels 22 after placement of a wager. The top box 18 may include a lighted panel 17 , a video display (such as an LCD monitor), a mechanical bonus device (not shown), and a candle light indicator 19 . The player interface panel 30 may include various devices so that a player can interact with the gaming device 10 .
[0018] The player interface panel 30 may include one or more game buttons 32 that can be actuated by the player to cause the gaming device 10 to perform a specific action. For example, some of the game buttons 32 may cause the gaming device 10 to bet a credit to be wagered during the next game, change the number of lines being played on a multi-line game, cash out the credits remaining on the gaming device (as indicated on the credit meter 27 ), or request assistance from casino personnel, such as by lighting the candle 19 . In addition, the player interface panel 30 may include one or more game actuating buttons 33 . The game actuating buttons 33 may initiate a game with a pre-specified amount of credits. On some gaming devices 10 a “Max Bet” game actuating button 33 may be included that places the maximum credit wager on a game and initiates the game. The player interface panel 30 may further include a bill acceptor 37 and a ticket printer 38 . The bill acceptor 37 may accept and validate paper money or previously printed tickets with a credit balance. The ticket printer 38 may print out tickets reflecting the balance of the credits that remain on the gaming device 10 when a player cashes out by pressing one of the game buttons 32 programmed to cause a ‘cashout.’ These tickets may be inserted into other gaming machines or redeemed at a cashier station or kiosk for cash.
[0019] The gaming device 10 may also include one or more speakers 26 to transmit auditory information or sounds to the player. The auditory information may include specific sounds associated with particular events that occur during game play on the gaming device 10 . For example, a particularly festive sound may be played during a large win or when a bonus is triggered. The speakers 26 may also transmit “attract” sounds to entice nearby players when the game is not currently being played.
[0020] The gaming device 10 may further include a secondary display 25 . This secondary display 25 may be a vacuum fluorescent display (VFD), a liquid crystal display (LCD), a cathode ray tube (CRT), a plasma screen, or the like. The secondary display 25 may show ancillary information to the player. For example, the secondary display 25 may show player tracking information, secondary bonus information, advertisements, or player selectable game options.
[0021] The gaming device 10 includes a microprocessor 40 that controls operation of the gaming device 10 . If the gaming device 10 is a standalone gaming device, the microprocessor 40 may control virtually all of the operations of the gaming devices and attached equipment, such as operating game logic stored in memory (not shown) as firmware, controlling the display 20 to represent the outcome of a game, communicate with the other peripheral devices (such as the bill acceptor 37 ), and orchestrating the lighting and sound emanating from the gaming device 10 . In other embodiments where the gaming device 10 is coupled to a network 50 , as described below, the microprocessor 40 may have different tasks depending on the setup and function of the gaming device. For example, the microprocessor 40 may be responsible for running the base game of the gaming device and executing instructions received over the network 50 from a bonus server or player tracking server. In a server-based gaming setup, the microprocessor 40 may act as a terminal to execute instructions from a remote server that is running game play on the gaming device.
[0022] The microprocessor 40 may be coupled to a machine communication interface (MCI) 42 that connects the gaming device 10 to a gaming network 50 . The MCI 42 may be coupled to the microprocessor 40 through a serial connection, a parallel connection, an optical connection, or in some cases a wireless connection. The gaming device 10 may include memory 41 (MEM), such as a random access memory (RAM), coupled to the microprocessor 40 and which can be used to store gaming information, such as storing total coin-in statistics about a present or past gaming session, which can be communicated to a remote server or database through the MCI 42 . The MCI 42 may also facilitate communication between the network 50 and the secondary display 25 or a player tracking unit 45 housed in the gaming cabinet 15 .
[0023] The player tracking unit 45 may include an identification device 46 and one or more buttons 47 associated with the player tracking unit 45 . The identification device 46 serves to identify a player, by, for example, reading a player-tracking device, such as a player tracking card that is issued by the casino to individual players who choose to have such a card. The identification device 46 may instead, or additionally, identify players through other methods. Player tracking systems using player tracking cards and card readers 46 are known in the art. Briefly summarizing such a system, a player registers with the casino prior to commencing gaming. The casino issues a unique player-tracking card to the player and opens a corresponding player account that is stored on a server or host computer, described below with reference to FIG. 3 . The player account may include the player's name and mailing address and other information of interest to the casino in connection with marketing efforts. Prior to playing one of the gaming devices in the casino, the player inserts the player tracking card into the identification device 46 thus permitting the casino to track player activity, such as amounts wagered, credits won, and rate of play.
[0024] To induce the player to use the card and be an identified player, the casino may award each player points proportional to the money or credits wagered by the player. Players typically accrue points at a rate related to the amount wagered, although other factors may cause the casino to award the player various amounts. The points may be displayed on the secondary display 25 or using other methods. In conventional player tracking systems, the player may take his or her card to a special desk in the casino where a casino employee scans the card to determine how many accrued points are in the player's account. The player may redeem points for selected merchandise, meals in casino restaurants, or the like, which each have assigned point values. In some player tracking systems, the player may use the secondary display 25 to access their player tracking account, such as to check a total number of points, redeem points for various services, make changes to their account, or download promotional credits to the gaming device 10 . In other embodiments, the identification device 46 may read other identifying cards (such as driver licenses, credit cards, etc.) to identify a player and match them to a corresponding player tracking account. Although FIG. 1A shows the player tracking unit 45 with a card reader as the identification device 46 , other embodiments may include a player tracking unit 45 with a biometric scanner, PIN code acceptor, or other methods of identifying a player to pair the player with their player tracking account.
[0025] During typical play on a gaming device 10 , a player plays a game by placing a wager and then initiating a gaming session. The player may initially insert monetary bills or previously printed tickets with a credit value into the bill acceptor 37 . The player may also put coins into a coin acceptor (not shown) or a credit card into a card reader/authorizer (not shown). The credit meter 27 displays the numeric credit value of the money inserted dependent on the denomination of the gaming device 10 . That is, if the gaming device 10 is a nickel slot machine and a $20 bill inserted into the bill acceptor 37 , the credit meter will reflect 400 credits or one credit for each nickel of the inserted twenty dollars. For gaming devices 10 that support multiple denominations, the credit meter 27 will reflect the amount of credits relative to the denomination selected. Thus, in the above example, if a penny denomination is selected after the $20 is inserted the credit meter will change from 400 credits to 2000 credits.
[0026] A wager may be placed by pushing one or more of the game buttons 32 , which may be reflected on the bet meter 28 . That is, the player can generally depress a “bet one” button (one of the buttons on the player interface panel 30 , such as 32 ), which transfers one credit from the credit meter 27 to the bet meter 28 . Each time the button 32 is depressed an additional single credit transfers to the bet meter 28 up to a maximum bet that can be placed on a single play of the electronic gaming device 10 . The gaming session may be initiated by pulling the gaming handle 12 or depressing the spin button 33 . On some gaming devices 10 , a “max bet” button (another one of the buttons 32 on the player interface panel 30 ) may be depressed to wager the maximum number of credits supported by the gaming device 10 and initiate a gaming session.
[0027] If the gaming session does not result in any winning combination, the process of placing a wager may be repeated by the player. Alternatively, the player may cash out any remaining credits on the credit meter 27 by depressing the “cash-out” button (another button 32 on the player interface panel 30 ), which causes the credits on the credit meter 27 to be paid out in the form of a ticket through the ticket printer 38 , or may be paid out in the form of returning coins from a coin hopper (not shown) to a coin return tray.
[0028] If instead a winning combination (win) appears on the display 20 , the award corresponding to the winning combination is immediately applied to the credit meter 27 . For example, if the gaming device 10 is a slot machine, a winning combination of symbols 23 may land on a played payline on reels 22 . If any bonus games are initiated, the gaming device 10 may enter into a bonus mode or simply award the player with a bonus amount of credits that are applied to the credit meter 27 .
[0029] FIGS. 2A to 2C illustrate exemplary types of gaming devices according to embodiments of the invention. FIG. 2A illustrates an example spinning-reel gaming machine 10 A, FIG. 2B illustrates an example video slot machine 10 B, and FIG. 2C illustrates an example video poker machine 10 C.
[0030] Referring to FIG. 2A , a spinning-reel gaming machine 10 A includes a gaming display 20 A having a plurality of mechanical spinning reels 22 A. Typically, spinning-reel gaming machines 10 A have three to five spinning reels 22 A. Each of the spinning reels 22 A has multiple symbols 23 A that may be separated by blank areas on the spinning reels 22 A, although the presence of blank areas typically depends on the number of reels 22 A present in the gaming device 10 A and the number of different symbols 23 A that may appear on the spinning reels 22 A. Each of the symbols 22 A or blank areas makes up a “stop” on the spinning reel 22 A where the reel 22 A comes to rest after a spin. Although the spinning reels 22 A of various games 10 A may have various numbers of stops, many conventional spinning-reel gaming devices 10 A have reels 22 A with twenty two stops.
[0031] During game play, the spinning reels 22 A may be controlled by stepper motors (not shown) under the direction of the microprocessor 40 ( FIG. 1A ). Thus, although the spinning-reel gaming device 10 A has mechanical based spinning reels 22 A, the movement of the reels themselves is electronically controlled to spin and stop. This electronic control is advantageous because it allows a virtual reel strip to be stored in the memory 41 of the gaming device 10 A, where various “virtual stops” are mapped to each physical stop on the physical reel 22 A. This mapping allows the gaming device 10 A to establish greater awards and bonuses available to the player because of the increased number of possible combinations afforded by the virtual reel strips.
[0032] A gaming session on a spinning reel slot machine 10 A typically includes the player pressing the “bet-one” button (one of the game buttons 32 A) to wager a desired number of credits followed by pulling the gaming handle 12 ( FIGS. 1A , 1 B) or pressing the spin button 33 A to spin the reels 22 A. Alternatively, the player may simply press the “max-bet” button (another one of the game buttons 32 A) to both wager the maximum number of credits permitted and initiate the spinning of the reels 22 A. The spinning reels 22 A may all stop at the same time or may individually stop one after another (typically from left to right) to build player anticipation. Because the display 20 A usually cannot be physically modified, some spinning reel slot machines 10 A include an electronic display screen in the top box 18 ( FIG. 1B ), a mechanical bonus mechanism in the top box 18 , or a secondary display 25 ( FIG. 1A ) to execute a bonus.
[0033] Referring to FIG. 2B , a video gaming machine 10 B may include a video display 20 B to display virtual spinning reels 22 B and various other gaming information 21 B. The video display 20 B may be a CRT, LCD, plasma screen, or the like. It is usually preferable that the video display 20 B be a touchscreen to accept player input. A number of symbols 23 B appear on each of the virtual spinning reels 22 B. Although FIG. 2B shows five virtual spinning reels 22 B, the flexibility of the video display 20 B allows for various reel 22 B and game configurations. For example, some video slot games 10 B spin reels for each individual symbol position (or stop) that appears on the video display 20 B. That is, each symbol position on the screen is independent of every other position during the gaming sessions. In these types of games, very large numbers of pay lines or multiple super scatter pays can be utilized since similar symbols could appear at every symbol position on the video display 20 B. On the other hand, other video slot games 10 B more closely resemble the mechanical spinning reel games where symbols that are vertically adjacent to each other are part of the same continuous virtual spinning reel 22 B.
[0034] Because the virtual spinning reels 22 B, by virtue of being computer implemented, can have almost any number of stops on a reel strip, it is much easier to have a greater variety of displayed outcomes as compared to spinning-reel slot machines 10 A ( FIG. 2A ) that have a fixed number of physical stops on each spinning reel 22 A.
[0035] With the possible increases in reel 22 B numbers and configurations over the mechanical gaming device 10 A, video gaming devices 10 B often have multiple paylines 24 that may be played. By having more paylines 24 available to play, the player may be more likely to have a winning combination when the reels 22 B stop and the gaming session ends. However, since the player typically must wager at least a minimum number of credits to enable each payline 24 to be eligible for winning, the overall odds of winning are not much different, if at all, than if the player is wagering only on a single payline. For example, in a five line game, the player may bet one credit per payline 24 and be eligible for winning symbol combinations that appear on any of the five played paylines 24 . This gives a total of five credits wagered and five possible winning paylines 24 . If, on the other hand, the player only wagers one credit on one payline 24 , but plays five gaming sessions, the odds of winning would be identical as above: five credits wagered and five possible winning paylines 24 .
[0036] Because the video display 20 B can easily modify the image output by the video display 20 B, bonuses, such as second screen bonuses are relatively easy to award on the video slot game 10 B. That is, if a bonus is triggered during game play, the video display 20 B may simply store the resulting screen shot in memory and display a bonus sequence on the video display 20 B. After the bonus sequence is completed, the video display 20 B may then retrieve the previous screen shot and information from memory, and re-display that image.
[0037] Also, as mentioned above, the video display 20 B may allow various other game information 21 B to be displayed. For example, as shown in FIG. 2B , banner information may be displayed above the spinning reels 22 B to inform the player, perhaps, which symbol combination is needed to trigger a bonus. Also, instead of providing a separate credit meter 27 ( FIG. 1A ) and bet meter 28 , the same information can instead be displayed on the video display 20 B. In addition, “soft buttons” 29 B such as a “spin” button or “help/see pays” button may be built using the touch screen video display 20 B. Such customization and ease of changing the image shown on the display 20 B adds to the flexibility of the game 10 B.
[0038] Even with the improved flexibility afforded by the video display 20 B, several physical buttons 32 B and 33 B are usually provided on video slot machines 10 B. These buttons may include game buttons 32 B that allow a player to choose the number of paylines 24 he or she would like to play and the number of credits wagered on each payline 24 . In addition, a max bet button (one of the game buttons 32 B) allows a player to place a maximum credit wager on the maximum number of available paylines 24 and initiate a gaming session. A repeat bet or spin button 33 B may also be used to initiate each gaming session when the max bet button is not used.
[0039] Referring to FIG. 2C , a video poker gaming device 10 C may include a video display 20 C that is physically similar to the video display 20 B shown in FIG. 2B . The video display 20 C may show a poker hand of five cards 23 C and various other player information 21 C including a paytable for various winning hands, as well as a plurality of player selectable soft buttons 29 C. The video display 20 C may present a poker hand of five cards 23 C and various other player information 21 C including a number of player selectable soft (touch-screen) buttons 29 C and a paytable for various winning hands. Although the embodiment illustrated in FIG. 3C shows only one hand of poker on the video display 20 C, various other video poker machines 10 C may show several poker hands (multi-hand poker). Typically, video poker machines 10 C play “draw” poker in which a player is dealt a hand of five cards, has the opportunity to hold any combination of those five cards, and then draws new cards to replace the discarded ones. All pays are usually given for winning combinations resulting from the final hand, although some video poker games 10 C may give bonus credits for certain combinations received on the first hand before the draw. In the example shown in FIG. 2C a player has been dealt two aces, a three, a six, and a nine. The video poker game 10 C may provide a bonus or payout for the player having been dealt the pair of aces, even before the player decides what to discard in the draw. Since pairs, three of a kind, etc. are typically needed for wins, a player would likely hold the two aces that have been dealt and draw three cards to replace the three, six, and nine in the hope of receiving additional aces or other cards leading to a winning combination with a higher award amount. After the draw and revealing of the final hand, the video poker game 10 C typically awards any credits won to the credit meter.
[0040] The player selectable soft buttons 29 C appearing on the screen respectively correspond to each card on the video display 20 C. These soft buttons 29 C allow players to select specific cards on the video display 20 C such that the card corresponding to the selected soft button is “held” before the draw. Typically, video poker machines 10 C also include physical game buttons 32 C that correspond to the cards in the hand and may be selected to hold a corresponding card. A deal/draw button 33 C may also be included to initiate a gaming session after credits have been wagered (with a bet button 32 C, for example) and to draw any cards not held after the first hand is displayed.
[0041] Although examples of a spinning reel slot machine 10 A, a video slot machine 10 B, and a video poker machine 10 C have been illustrated in FIGS. 2A-2C , gaming machines various other types of gaming devices known in the art are contemplated and are within the scope of the invention.
[0042] Each of the gaming devices in FIGS. 2A through 2C has a game environment. The game environment can include sounds emitted from the gaming device and any portion of the visual information displayed to a player.
[0043] FIG. 3 is a block diagram illustrating networked gaming devices according to embodiments of the invention. Referring to FIG. 3 , multiple electronic gaming devices (EGMs) 70 , 71 , 72 , 73 , 74 , and 75 may be coupled to one another and coupled to a remote server 80 through a network 50 . For ease of understanding, gaming devices or EGMs 70 , 71 , 72 , 73 , 74 , and 75 are generically referred to as EGMs 70 - 75 . The term EGMs 70 - 75 , however, may refer to any combination of one or more of EGMs 70 , 71 , 72 , 73 , 74 , and 75 . Additionally, the gaming server 80 may be coupled to one or more gaming databases 90 . These gaming network 50 connections may allow multiple gaming devices 70 - 75 to remain in communication with one another during particular gaming modes such as tournament play or remote head-to-head play. Although some of the gaming devices 70 - 75 coupled on the gaming network 50 may resemble the gaming devices 10 , 10 A, 10 B, and 10 C shown in FIGS. 1A-1B and 2 A- 2 C, other coupled gaming devices 70 - 75 may include differently configured gaming devices. For example, the gaming devices 70 - 75 may include traditional slot machines 75 directly coupled to the network 50 , banks of gaming devices 70 coupled to the network 50 , banks of gaming devices 70 coupled to the network through a bank controller 60 , wireless handheld gaming machines 72 and cell phones 73 coupled to the gaming network 50 through one or more wireless routers or antennas 61 , personal computers 74 coupled to the network 50 through the internet 62 , and banks of gaming devices 71 coupled to the network through one or more optical connection lines 64 . Additionally, some of the traditional gaming devices 70 , 71 , and 75 may include electronic gaming tables, multi-station gaming devices, or electronic components operating in conjunction with non-gaming components, such as automatic card readers, chip readers, and chip counters, for example.
[0044] Gaming devices 71 coupled over an optical line 64 may be remote gaming devices in a different location or casino. The optical line 64 may be coupled to the gaming network 50 through an electronic to optical signal converter 63 and may be coupled to the gaming devices 71 through an optical to electronic signal converter 65 . The banks of gaming devices 70 coupled to the network 50 may be coupled through a bank controller 60 for compatibility purposes, for local organization and control, or for signal buffering purposes. The network 50 may include serial or parallel signal transmission lines and carry data in accordance with data transfer protocols such as Ethernet transmission lines, firewire lines, USB lines, or other communication protocols. Although not shown in FIG. 3 , substantially the entire network 50 may be made of optical lines 64 or may be a wireless network.
[0045] As mentioned above, each gaming device 70 - 75 may have an individual processor 40 ( FIG. 1A ) and memory 41 to run and control game play on the gaming device 70 - 75 , or some of the gaming devices 70 - 75 may be terminals that are run by a remote server 80 in a server based gaming environment. Server based gaming environments may be advantageous to casinos by allowing fast downloading of particular game types or themes based on casino preference or player selection. Additionally, tournament based games, linked games, and certain game types, such as BINGO or keno may benefit from at least some server 80 based control.
[0046] Thus, in some embodiments, the network 50 , server 80 , and database 90 may be dedicated to communications regarding specific game or tournament play. In other embodiments, however, the network 50 , server 80 , and database 90 may be part of a player tracking network. For player tracking capabilities, when a player inserts a player tracking card in the card reader 46 ( FIG. 1A ), the player tracking unit 45 sends player identification information obtained on the card reader 46 through the MCI 42 over the network 50 to the player tracking server 80 , where the player identification information is compared to player information records on in the player database 90 to provide the player with information regarding their player accounts or other features at the gaming device 10 where the player is wagering. Additionally, multiple databases 90 and/or servers 80 may be present and coupled to one or more networks 50 to provide a variety of gaming services, such as both game/tournament data and player tracking data.
[0047] The various systems described with reference to FIGS. 1-3 can be used in a number of ways. For instance, the systems can be used to track data about various players. The tracked data can be used by the casino to provide additional benefits to players, such as extra bonuses or extra benefits such as bonus games and other benefits as described above. These added benefits further entice the players to play at the casino that provides the benefits.
[0048] FIG. 4 illustrates an example video slot machine according to some embodiments of the invention.
[0049] Referring to FIG. 4 , a video slot machine 110 includes unlockable symbols 123 B- 1 , 123 B- 2 , and 123 B- 3 that are different from the default symbols (i.e., symbols 23 B shown in FIG. 2B ) displayed on the machine. Unlockable symbol 123 B- 1 is a static symbol that is different from the default symbols ordinarily displayed on the video slot machine 110 . For example, unlockable symbol 123 B- 1 could be a gold coin that is displayed in place of a specific default symbol on the reels 122 B. Unlockable symbol 123 B- 2 is an animated symbol that is different from the default symbols ordinarily displayed on the video slot machine 110 . For example, unlockable symbol 123 B- 2 could be a stick figure that moves within a pre-defined area of each of the reels 122 B (as shown by the dotted figures and arrows) and that is displayed in place of a specific default symbol on the reels 122 B. Unlockable symbol 123 B- 3 is a modified presentation of one of the default symbols ordinarily displayed on the video slot machine 110 . For example, unlockable symbol 123 B- 3 could be a default symbol that has been modified to flash on and off (as shown by dotted accent lines).
[0050] A person of ordinary skill in the art will appreciate that unlockable symbols 123 B- 1 , 123 B- 2 , and 123 B- 3 are just a few examples of many possible unlockable symbols that fall within the scope of the invention. Further, according to some embodiments of the invention, the unlockable symbol 123 B could be the same as one of the default symbols, such that triggering the unlockable symbols 123 B results in replacement of one of the default symbols with another one of the default symbols. The net effect of such a change is to decrease the total number of symbols present on the reels 122 B. The player may perceive this change as increasing the chances of obtaining a win result, but the chances of obtaining a win result are not necessarily increased.
[0051] Unlocking of the unlockable features on the video slot machine 110 can be associated with many possible triggers. For example, triggering of a specific unlockable feature can be associated with a pre-set number of consecutive plays by a single player on the video slot machine 110 . Many other triggers can lead to unlocking of the unlockable features including, but not limited to: a specific amount of credits wagered by a player; an amount of time the player has spent on a single machine; an amount of credits won by the player on a specific machine; a number of plays without a payout on a specific machine; and trend data associated with the player. Each trigger has an underlying basis. For instance, when the trigger is 500 credits wagered by a player, the underlying basis for the trigger is the number of credits wagered by the player. Also, the unlockable features can be tiered such that a first unlockable feature is unlocked when a first condition is reached, a second unlockable feature is unlocked when a second condition is reached, and so on. The unlockable features can be cumulative, such that the second unlockable feature adds to the first unlockable feature, or the unlockable features can be sequential, such that the second unlockable feature replaces the first unlockable feature.
[0052] The triggers that result in unlocking of unlockable features can be machine specific and/or player specific. In other words, the triggers can be tied to the player's use of a specific machine or the triggers can be tied to the player's use of many different machines over time. In the latter case, the player's status with respect to the triggers can be maintained in the player's account. As an example, a trigger for an unlockable feature could be a total amount wagered by a player on a given day, independent of which machines the wagers were placed on. The total amount wagered can be tracked in the player's account such that when the trigger is met, the unlockable feature is unlocked on whichever machine the player is using at that particular time. The unlocked feature can then be available on any machine that the player uses, as long as the player is using their player account on the machine.
[0053] The video slot machine 110 can determine whether any unlockable features have been triggered on an ongoing basis as a player sequentially initiates gaming sessions on the machine. If the player provides identifying information to the video slot machine 110 , the machine can determine if any unlockable features are available to the player based on the player account associated with the player before the player initiates a first gaming session. Then, video slot machine 110 can determine whether any unlockable features have been triggered on an ongoing basis as the player sequentially initiates gaming sessions on the machine.
[0054] As shown in FIG. 4 , gaming information 121 B can display the status of unlockable features on the video slot machine 110 . For example, the gaming information 121 B can display a message indicating new unlockable features (new from the player's perspective) have been unlocked. Further, the gaming information 121 B can display a message indicating that unlockable features are available and also indicating the conditions upon which the unlockable features can be unlocked.
[0055] Many aspects of the game environment on the video slot machine 110 can be altered by unlockable features. For example, the color scheme of the gaming display 1 20 B can be tied to an unlockable feature such that when the unlockable feature is triggered, the colors of different elements in the gaming display 120 B can be changed. As another example, the number of reels 122 B can be changed when an unlockable feature is triggered. Additionally, the flow of a gaming session can also be altered by unlockable features. For instance, a ‘multiple stops’ unlockable feature can be activated so that the player can stop each reel 122 B on a video slot machine 110 independently by sequentially pressing a stop button. Although the player may perceive that the ‘multiple stops’ unlockable feature improves the player's chances of obtaining a win result, this is not necessarily the case.
[0056] A person of ordinary skill in the art will appreciate that many other types of unlockable features could be provided and the unlockable features do not have to be specific to the game environment. For example, an unlockable feature could unlock a different game on a particular gaming device, different music (which could be designated in the player account), television programming, and/or drink service. Also, unlockable features could provide features outside the context of the gaming device such as free food (a steak dinner at a particular venue), a free night stay at a particular venue, a ticket to a show, etc. Further, an unlockable feature could be recognition on a public display of the player's accomplishment. For instance, a particular venue may have a display showing a ‘Lucky Players List’ and an unlockable feature could allow the player's name, picture, an animated likeness of the player, etc. to be added to the list.
[0057] Another aspect of the game environment that can be modified by the unlockable features is the sound scheme. For example, the background music associated with the video slot machine 110 and the sounds associated with particular events can both be altered by an unlockable feature. Also, event sounds can be tied to the unlockable symbols 123 B. In one example, an unlockable symbol 123 B could be an animated face that has moving lips timed to correspond with sounds emitted from the speaker 26 to give the impression that the animated face is ‘talking’ to the player. The animated face can provide words of encouragement (i.e., “Give it another try; your luck is bound to change”) or taunt the player (i.e., “Give up now; you're never gonna win”) dependent upon trend data associated with the player. Alternatively, the animated face can simply provide statements that are not tied to any particular trend data (i.e., “Nice weather we're having”).
[0058] The unlockable features can be organized into unlockable feature packages. Each unlockable feature package can include multiple unlockable features including, but not limited to: a different color scheme in the gaming display 120 B; different unlockable symbols 123 B; and a different sound scheme. For example, a ‘stick figure’ unlockable feature package could replace multiple default symbols with animated stick figures performing various activities and sounds corresponding to the various activities. As another example, an ‘animated faces’ unlockable feature package could replace one or more default symbols with animated faces, which may or may not ‘talk’ to the player as described above.
[0059] Although it may be advantageous to the casino to identify to the player what unlockable features are available on a machine, this does not have to be the case. Unlockable features can be triggered without any prior knowledge by the player. Further, even if the player does know what unlockable features are available, it is not necessary that the player even know what the triggers are for the unlockable features, or in what order the features will unlock. From the player's perspective, the triggering of the unlockable features could be tied to unknown events or even have the appearance of being random. Further, a player could opt out of unlockable features altogether either on a particular gaming device or through an opt-out feature in the associated player account.
[0060] The video slot machine 110 can also include an unlockable feature management button 129 B. The unlockable feature management button 129 B can be displayed in the gaming display 120 B whenever an unlockable feature is active on the video slot machine 110 . The unlockable feature management button 129 B can be activated by the player (by touching the button on a touch screen, for example) to cause the video slot machine 110 to display an alternate screen as shown in FIG. 5 .
[0061] FIG. 5 illustrates an unlockable feature management screen according to some embodiments of the invention.
[0062] Referring to FIG. 5 , upon activation of an unlockable feature management button 129 B by a player, the video slot machine 110 can display an unlockable feature management screen in the gaming display 120 B. The unlockable feature management screen can include: a list of active unlockable features 129 B- 1 ; a list of available unlockable features 129 B- 2 ; and/or a close button 129 B- 3 . The list of active unlockable features 129 B- 1 can display to the player all of the unlockable features that are currently active on the gaming machine. The player can disable any or all of the active unlockable features from the list of active unlockable features 129 B- 1 by, for example, touching the feature in the list.
[0063] The list of available unlockable features 129 B- 2 can display to the player all of the unlockable features that are available on the machine along with the trigger for unlocking each of the available unlockable features. Alternatively, the list of available unlockable features 129 B- 2 can display only those unlockable features for which the player is likely to achieve the trigger within a pre-set time interval. For example, if a player has wagered 95 credits on a specific machine and a first unlockable feature is triggered when the player wagers 100 credits, the first unlockable feature may be displayed in the list of available unlockable features 129 B- 2 . On the other hand, if a second unlockable feature is not triggered until the player wagers 1000 credits, the second unlockable feature might not be displayed in the list of available unlockable features 129 B- 2 .
[0064] The close button 129 B- 3 can be used to close the unlockable feature management screen and return to the gaming screen, as shown in FIG. 4 . The close button 129 B- 3 does not necessarily have the word “Close” on it; the button could have any other word that would indicate to the player that they will be returned to the previous screen, such as: “Cancel”, “Return”, or “Back”.
[0065] According to some embodiments of the invention, when an unlockable feature is triggered, the gaming device 110 can prompt the player to accept or decline the unlockable feature. The gaming device 110 can prompt the player by, for example, displaying an alternate screen in the gaming display 120 , as shown in FIG. 6 .
[0066] FIG. 6 illustrates an unlockable feature acceptance screen according to some embodiments of the invention.
[0067] Referring to FIG. 6 , during the course of game play, if a player triggers an unlockable feature, the video slot machine 110 can display an unlockable feature acceptance screen. The unlockable feature acceptance screen can include: an identifier 129 B- 4 for the triggered unlockable feature; a description 129 B- 5 of the triggered unlockable feature; an accept button 129 B- 6 ; and a decline button 129 B- 7 . The identifier 129 B- 4 can indicate to the player which unlockable feature has been triggered. The description 129 B- 5 can provide a brief description of the effect that the triggered unlockable feature will have on the game environment. The accept button 129 B- 6 and the decline button 129 B- 7 can be used by the player to either activate the unlockable feature or decline to activate the feature. The accept button 129 B- 6 and the decline button 129 B- 7 do not necessarily have the words “Activate” and “Decline” on them. The buttons could have any other words on them that convey to the player that the unlockable feature can be activated or declined including: “Accept”, “Reject”, “Cancel”, or “Continue”.
[0068] The triggers for the unlockable features can be linear, non-linear, or a combination of both. For example, a new unlockable feature can be triggered at each linear increment of an underlying basis (i.e. 50, 100, 150 . . . credits wagered on a given machine). Alternatively, a new unlockable feature can be triggered at non-linear intervals of the underlying basis (i.e. 50, 150, 500 . . . credits wagered on a given machine).
[0069] According to some embodiments of the invention, the unlockable features can be conditional. As used here, the term conditional means that by choosing to activate a first unlockable feature the trigger point for a second unlockable feature becomes more remote from the player's current status. As an example, the trigger for a first unlockable feature might be 5 minutes of play time on a given machine and the trigger for a second unlockable feature might be 10 minutes of play time on the machine. However, if the player chooses to activate the first unlockable feature when it is triggered, the time is reset, so that the player will have to play for an additional 10 minutes in order to trigger the second unlockable feature. Thus, when the unlockable features are conditional, the player has to play for 15 minutes to unlock both the first and second unlockable features, but if the unlockable features are not conditional, the player would only have to play for 10 minutes to unlock both the first and second unlockable features. When the unlockable features are conditional, the player can activate only the second unlockable feature by declining to activate the first unlockable feature after 5 minutes and accepting the activation of the second unlockable feature after 10 minutes.
[0070] FIG. 7 illustrates a conditional unlockable feature acceptance screen according to some embodiments of the invention.
[0071] Referring to FIG. 7 , a conditional unlockable feature acceptance screen includes similar features to those described above with respect to FIG. 6 . However, the conditional unlockable feature acceptance screen also includes a tempt message 129 B- 8 . The tempt message 129 B- 8 notifies the player of what unlockable feature will next become available if the player does not activate the currently triggered unlockable feature.
[0072] Conditional unlockable features can be especially suited for situations in which later unlockable features are perceived to be ‘better’ by the player than earlier unlockable features in a non-linear fashion. This is the case independent of the validity of the player's perception. For example, the player may perceive that a second unlockable feature, such as ‘fewer number of reels’, is more likely to result in wins for the player than a first unlockable feature, such as a blue color scheme. Therefore, the player may be willing to forego the first unlockable feature so that the second unlockable feature can be triggered sooner. The validity of the player's perception regarding the fewer number of reels is not important. Conditional unlockable features can increase the perception of ‘scarcity’ of the later unlockable features and thus increase the player's excitement at having triggered the later unlockable features.
[0073] In some cases, the player may not know which unlockable features become available later, but the player may know that by foregoing the earlier unlockable features, the player increases the chances of triggering the later unlockable features (or decreases the trigger point for the later unlockable features). Additionally, the player may perceive that the later unlockable features are ‘better’ than the earlier unlockable features. Thus, the player may choose to gamble on foregoing the earlier unlockable features in the hopes of triggering the later unlockable features. Such behavior by the player can be termed meta-gambling, as the player is gambling about gambling. Conditional unlockable features can be used to encourage meta-gambling because in addition to the desired outcome of payouts from the gaming machine, the player has a secondary desired outcome of achieving later unlockable features. This meta-gambling effect can be used to encourage a player to prolong play on a given machine or in a given venue, as opposed to changing machines and/or venues.
[0074] According to some embodiments of the invention, unlockable features can be managed through the use of unlocking points. A player can accumulate unlocking points on an individual machine basis or on a player account basis. Specifically, the player can accumulate unlocking points while playing on a given machine and the unlocking points can be used to unlock features only on the given machine. Alternatively, the player can accumulate unlocking points on their player account from play on multiple gaming machines and the unlocking points can be redeemed to unlock features on any of the gaming machines. The current number of unlocking points available to a player can be displayed in the gaming display 120 B of the video slot machine 110 . Alternatively, the player may not even be aware of the existence of the locking points. The number of unlocking points necessary to trigger the next available unlockable feature can also be displayed in the gaming display 120 B, as player information 121 B for example. Unlocking points can be used to enforce conditional unlockable features because when the player chooses to activate a conditional unlockable feature that has been triggered, the appropriate amount of unlocking points can be deducted from the player account (or the number of unlocking points accumulated on the machine). It should be noted that unlocking points (and unlockable features in general) do not need to be tied to positive player statistics. In other words, a player could accumulate unlocking points even when the player is not getting ‘win’ results from their gaming.
[0075] Unlocking points can also be used to tally multiple player statistics into a single value that can be easily redeemed by the player for unlockable features. For example, specified amounts of play time can be tallied as a specific number of unlocking points and the amount wagered by a player on a given day can also be tallied as another specific number of unlocking points. In this way, the unlocking points can represent an aggregate of the many player statistics that can lead to triggering unlockable features.
[0076] Alternatively, each player statistic can be tallied as a separate pool of unlocking points. For example, a player account can accumulate first unlocking points that are associated with an amount of time played and second unlocking points that are associated with an amount wagered on a given day. These different unlocking points can be redeemed cumulatively or separately to unlock unlockable features.
[0077] A person of ordinary skill in the art will appreciate that different unlockable features can be available on different types of gaming machines. For example, a ‘reduced number of reels’ unlockable feature would be applicable to a video slot machine, but not applicable to a video poker machine. Similarly, an ‘animated card faces’ unlockable feature would be applicable to the video poker machine, but not applicable to the video slot machine. Consequently, the same trigger point for a particular underlying basis can lead to different unlockable features being triggered on different machines. For example, if the underlying basis is amount of credits wagered by a player, at a trigger point of 50 credits, a ‘reduced number of reels’ unlockable feature could be triggered if the player is playing a video slot machine, while an ‘animated card faces’ unlockable feature could be triggered if the player is playing a video poker machine.
[0078] Unlockable features can also be organized into levels. In other words, instead of unlocking a specific feature when a certain trigger point is reached, the trigger could be used to set a player level (i.e., Level One, Level Two, Silver Level, Gold Level, etc). The player level can then be used as a proxy for the unlockable features. For example, a Level Two player can have certain unlockable features available, while a Level Three player can have certain additional or different unlockable features available. The player levels can be managed locally on a specific gaming device or they can be managed in the player account.
[0079] Also, unlockable features can be organized into categories. For example, unlockable features could include: gaming machine play modes (that affect play on game, reels, etc.); visual or aural game environment features (colors, sounds, etc.); external features (free drink service, steak dinner, show tickets, etc.); and vanity features (overhead displays, recognition messages emanating from the gaming device, etc.). A player could choose which category of unlockable features the player would like to have available either on a machine-specific basis or in the player account.
[0080] According to embodiments of the invention, unlockable features can be used to change the game environment on a gaming machine. The unlockable features can be triggered by many different player statistics accumulated on a single machine or multiple machines using a player account.
[0081] Some embodiments of the invention have been described above, and in addition, some specific details are shown for purposes of illustrating the inventive principles. However, numerous other arrangements may be devised in accordance with the inventive principles of this patent disclosure. Further, well known processes have not been described in detail in order not to obscure the invention. Thus, while the invention is described in conjunction with the specific embodiments illustrated in the drawings, it is not limited to these embodiments or drawings. Rather, the invention is intended to cover alternatives, modifications, and equivalents that come within the scope and spirit of the inventive principles set out in the appended claims.
|
Embodiments of the present invention are directed to a gaming device with unlockable features. The unlockable features can change default settings in the game environment of the gaming device and provide game mode changes, vanity features, and external features to the player. The unlockable game environment features can be different sound schemes, different static images, flashing images, and animations. The unlockable features can be triggered based on various player statistics and can be managed in a player account. The player can manage the unlockable features interactively on the gaming device.
| 6
|
This application is a Division of application Ser. No. 08/044,097/, filed Apr. 6, 1993 which is a continuation of Ser. No. 07/804,564, filed Dec. 10, 1991, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to fixed body conformal antenna systems and, more specifically, to a broad-band, wide field-of-view (FOV) direction finding (DF) interferometer array for missile type applications.
2. Brief Description of the Prior Art
High performance missile systems require highly accurate broadband DF performance such as low angle-of-arrival (AOA) error, low AOA error rates and large fields-of-view. In the prior art, the approach used to meet these requirements has been to mount an antenna array on a gimbal and to point the antenna array boresight in the direction of the target. The system generally used two fixed antennas to determine azimuth and two fixed antennas to determine elevation with the system generally switching between the two antenna pairs to constantly monitor azimuth and elevation. Maintaining the array boresight aligned with the target reduced DF errors by maintaining the targets within the useable FOV of the antenna array. Unfortunately, this approach suffered from several shortcomings which are described hereinbelow.
The use of fixed antennas permits only the look ahead type of operation and makes it difficult to recognize a target located on the ground or anywhere other than in the narrow field of view of the antenna system. Typically, an antenna array of this type has been placed upon a gimbal with array movement on the gimbal so that the array can look down for the desired target. The gimbal is then reoriented so that the boresight of the array, which is on an axis through the center of all of the antennas, is oriented at the target.
One major deficiency of the above described type of antenna system is inadequate DF performance due to amplitude and phase perturbations induced on the direction finding antennas by the multipath reflections between the bulkhead and gimbal structures and the radome inner surface. These multipath effects are compounded by the need to have broadband coarsely tuned radomes, reflective gimbal and missile seeker bulkhead structures and broad beam antennas.
Another deficiency encountered in a gimbal antenna system is the interaction and crosstalk between the individual antennas. This coupling corrupts the desired phase response between opposing antennas, consequently reducing the DF performance of the antenna array. The crosstalk can be caused by improperly terminated antennas which couple current onto the metallic gimbal structure and back into the other antennas.
A third problem encountered in the prior art of antenna DF systems is the need for the mechanical gimbals to point the interferometer array in the direction of the target. Gimbal systems generally increase cost and reduce reliability for long life cycle missile systems. In addition, radome cavity multipath perturbations on the antennas generally change as a function of gimbal angle, thereby creating target location variances on the DF performance within the FOV.
Also, the use of fixed antennas permits only the look ahead type of operation and makes it difficult to recognize a target located on the ground or anywhere other than in the narrow field of view of the antenna system.
Amplitude resolved phase DF processing would be a preferred DF processing approach for a low AOA error and low AOA error rate system, however the problems described above limit the ability of such systems to produce unambiguous phase DF. For an amplitude resolved phase DF process to operate properly, coarse amplitude DF angle resolution must be less than the minimum spatial phase ambiguity spacing. High axial ratio and non-linear DF transfer functions caused by the problems mentioned above force prior art systems to use amplitude only DF processing. Such systems are not capable of meeting high performance DF requirements because amplitude only DF systems typically have high polarization dependent AOA error envelopes and AOA error rates. These DF deficiencies become compounded by the problems mentioned above.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an antenna system having improved large FOV broad-band DF performance, primarily for missile type applications. The system in accordance with the present invention also provides a higher reliability, lower cost solution for missile interferometric DF arrays than was available in the prior art. This is accomplished by eliminating the need for a gimbal and radome. The method and system used to accomplish these objectives are summarized in the basic properties described hereinbelow. The following method and system is summarized for improved DF performance in the elevation down direction and can be repeated to improve DF performance in the remaining three DF sectors.
Briefly, there is provided an array of antennas, preferably but not limited to a 3 by 2 configuration of two columns and three rows on a hemispherical structure (the discussion hereinbelow will be directed to a 3×2 antenna array, it being understood that other configurations can also be used), the antennas being conformal with the hemisphere dome or surface. Each of the antennas is pointed in a different direction whereby each antenna has its maximum sensitivity aligned with its individual boresight. The axis or boresight of each of the antennas passes through the center of the sphere upon which the hemispherical structure is based. While the discussion will be confined to spiral antennas which are preferred, it should be understood that any type of antenna can be used, preferably a broad band type of antenna and preferably a spiral type of broadband antenna.
The axis or boresight of each of the top four antennas is disposed at a predetermined angle relative to the array boresight, generally in the range of from about 20° to about 45° with an angle of 30° relative to the array boresight being preferred due to simplification of the mathematics involved by using this angle. The axis or boresight of each of the bottom two antennas is disposed at a predetermined angle relative to an axis inclined about 45° downward from the array boresight and preferably at an angle of 30° relative to the axis inclined 45° downward from the array boresight to simplify the mathematics involved. This structure replaces the radome, the gimbal, and the four antennas of prior art DF systems. It should be understood that the orientation of the antennas herein is not critical as long as such orientation is known since such orientation can be taken into account during computation.
The center of the two antenna columns is aligned with the missile elevation plane and the axis through the center of the top four antennas coincides with the missile boresight. The hemispherical surface is an electrically conductive or absorber structure which, when electrically conductive, is preferably a metallic structure, a metal plated plastic or graphite reinforced composite. This surface serves two functions, these being first, the support of the six spiral antennas, and second, the isolation by the electrically conductive hemisphere of the forward hemispherical antenna beams from any undesirable reflections that can originate from the spiral backlobes.
Each antenna is surrounded by an absorber ring that is used to isolate each antenna from undesirable surface currents which may adversely affect antenna performance. In addition, each antenna is covered by a low dielectric cover of a thermosetting or thermoplastic nonmetallic material that may be reinforced with glass or quartz for additional strength. Any engineering plastic that can stand up to the environment and which shields the antenna from the environment can be used with polypropylene being preferred.
The six antennas operate as two basic four element sub-arrays with displaced boresight locations, these being the look forward and the look down sub-arrays. The top and middle rows of the antennas comprise the look forward sub-array and they are used to form DF information in the forward DF sector. The look forward boresight is aligned with the missile boresight. The middle and bottom rows of the antennas comprise the look down sub-array and perform DF in the elevation down DF sector. The look down boresight is displaced from the look ahead boresight in the negative elevation direction. Two microwave switches are used to switch between the top and bottom rows of antennas and the middle row of antennas is shared for both modes of operation.
Direction finding (DF) information is first produced in the antenna planes which are rotated 45° from the azimuth and elevation planes. The antenna planes are planes through the array boresight and the center of two antennas, one antenna from each of the two columns which are from different rows of the array. An amplitude resolved phase DF technique is employed for this invention because of its high DF performance capability. Euler angle transformations are used to rotate the antenna plane DF information back into the vehicle coordinate system in standard manner.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are plan and elevation views respectively of the conformal antenna array in accordance with the present invention;
FIG. 2 is a diagram of the switching network employed in accordance with the present invention;
FIG. 3 is an exploded cross sectional view of the antenna system in accordance with the present invention;
FIG. 4 is an elevation view of the assembled conformal antenna array in accordance with the present invention;
FIGS. 5A and 5B illustrate typical azimuth and elevation performance respectively of the antenna system in accordance with the present invention against a rotating linear source polarization; and
FIG. 6 illustrates alternate applications of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, FIGS. 1A and 1B show the plan view of the six two arm spiral antennas 2 to 7 mounted on the aluminum hemispherical missile nose piece 1. The top four antennas 2, 3, 4 and 5 are used in the look ahead mode of operation while the bottom four antennas 4, 5, 6 and 7 are used in the look down mode of operation, with antennas 4 and 5 being used in both modes of operation. The axes of the antennas 2, 3, 4 and 5 are disposed at an angle of 30° with respect to the look ahead boresight 8. The look ahead array boresight 8 is co-aligned with the missile boresight and the look down boresight 9 is displaced from the look ahead boresight in the negative elevation direction by 45 degrees. The antennas 6 and 7 are disposed at an angle of 30° with the look down boresight 9. Antennas 4 and 5 are disposed at an angle of 30° with respect to both boresight axes 8 and 9. The axes of all of the antennas 2 to 7 intersect at the center 19 of the sphere containing the hemisphere 18.
For look ahead operation, antenna elements 5 and 2 are compared to form an AOA estimate in antenna plane 10. Antenna plane 10 contains the centers of antenna elements 5 and 2 as well as the look ahead boresight 8. In addition, antenna elements 3 and 4 are ratioed to form an AOA estimate in antenna plane 11. Antenna plane 11 contains the centers of antenna elements 3 and 4 as well as look ahead boresight 8 and is orthogonal to antenna plane 10. A standard Euler angle transformation is performed to rotate the antenna plane AOA estimates into the vehicle azimuth plane 12 and elevation plane 13. The rotation is 45° about the look ahead boresight.
In the look down mode, antenna elements 5 and 6 are ratioed to form an AOA estimate in antenna plane 14 and antenna elements 7 and 4 are ratioed to form an AOA estimate in the antenna plane 15 which is orthogonal to antenna plane 14.
The microwave switching network shown in FIG. 2 is used to switch from antennas 2 and 3 in the look ahead mode to antennas 6 and 7 in the lookdown mode as will be described hereinbelow. To obtain superior performance antennas 2, 5 and 6 comprise one matched antenna set and antennas 3, 4 and 7 comprise the other matched antenna set. The same Euler angle transformations are used to provide an azimuth AOA estimate and an offset elevation AOA estimate. The elevation AOA estimate for this mode is offset from the vehicle elevation plane by the angle delta 16 shown in FIG. 1B which is the angle between the look ahead boresight axis 8 and the look down boresight axis 9.
The AOA estimates are formed using an amplitude resolved phase DF processing method. The phase response between the compared antennas is modeled as a sine function and the amplitude difference between two compared antennas is modeled using a linear approximation. These relationships are described below.
For the amplitude:
O.sub.cr =Amp.sub.-- ratio/Amp.sub.-- slope-Boresight.sub.-- amp.sub.-- comp(1)
Where:
O cr is the coarse amplitude AOA estimate in the antenna plane;
Amp -- ratio is the measured amplitude difference of the two compared antennas;
Amp -- slope is the calculated slope of the amplitude transfer function; and
Boresight -- amp -- comp is the measured amplitude difference at the array boresight.
For the phase:
=(360×d(Sin O)/)+N×360-boresight.sub.-- phase.sub.-- comp(2)
Where:
is the measured phase difference between the two compared antenna;
d is the physical distance between the two compared antennas (e.g., 17)
O is the fine AOA estimate in the interferometer plane;
N is the phase ambiguity integer;
Boresight -- phase -- comp is the measured phase difference at the array boresight; and
is the wavelength of the measured signal.
In the preceding description, O cr is first solved in Equation (1) hereinabove and then substituted into Equation (2) as O to solve for N. Equation (2) hereinabove is then re-evaluated to solve for O. In order to accurately resolve all phase ambiguities with the coarse amplitude DF, the following criteria must be met:
For /d<1.0
Axial.sub.-- ratio/Amp.sub.-- slope<Sin.sup.-1 (/d) (3)
Axial -- ratio=ratio of the major axis to the minor axis of the incident source polarization ellipse.
Meeting the preceding criteria ensures that the coarse amplitude DF will be fine enough to resolve the smallest phase ambiguities.
The system described in this invention requires four sets of compensation values for each array axis. The compensation values are array boresight phase differences and d for the phase and array boresight amplitude difference and slope for the amplitude. These compensation values can be calculated at boresight and ±15° in each antenna plane.
The Euler angle transformations used in this invention are shown below in their final form.
______________________________________Az = Sin.sup.-1 (1/2).sup.1/2 × (Sin(O.sub.1) + Sin(O.sub.2))!(4)E1 - = Sin.sup.-1 (1/2).sup.1/2 × (-Sin(O.sub.1) + Sin(O.sub.2))!(5)Where: O.sub.1 = Angle of arrival in antenna plane 10(15) (FIG. 1A) for the look ahead (down) mode;O.sub.2 = Angle of arrival in antenna plane 11(14) (FIG. 1A) for the look ahead (down) mode; and = The angle between the look ahead boresight 8 and the look down boresight 9 for the look down mode only (= 0 for the look ahead mode).______________________________________
Referring now to FIG. 2, there is shown a microwave switching network to switch from antennas 2 and 3 in the look ahead mode to antennas 6 and 7 in the look down mode. There is shown a first switch 40 which connects antenna 2 to the switch 42 in the look ahead mode and connects antenna 6 to switch 42 in the look down mode. The switch 41 connects antenna 3 to the switch 42 in the look ahead mode and connects antenna 7 to the switch 42 in the look down mode. The antennas 4 and 5 are always connected to the switch 43. The switch 43 can switch between antennas 4 and 5 whereas switch 42 can switch between the outputs of switches 40 and 41.
It is further noted that the switching arrangement shown in FIG. 2 can be eliminated and that the output of each antenna or sensor constantly be sent directly to a processor whereat the outputs are individually collected, operated upon and utilized to provide the desired information and perform the desired functions without the requirement of the switching arrangement. This is accomplished using plural channel receivers which are coupled to the individual antennas.
FIG. 3 illustrates a cross section of the antenna array of the present invention along plane 13 and normal to plane 12 defined in FIG. 1. The microwave switching network (FIG. 2) and other electronics are contained in the receiver module 18. Attached to the receiver module are preformed phased matched cables 19. The phase matched cables 19 use blind mate press on RF connectors 20 which are guided into antenna holding cups 21. The press on connectors 20 are secured to the holding cup 21 bases by screws 22. The receiver module 18 is held in place by screws 23 that screw into bosses 24. The bosses 24, like the antenna holding cups 21, are integral components of the hemispherical dome 25.
Once the receiver module 18 is secured to the hemispherical structure 25, the antennas 26 are inserted into the antenna holding cups 21. Antenna mounting screws 27 secure the antennas 26 to the antenna holding cups 21. Absorber rings 28 are placed around the antennas 26 to absorb skin currents that may adversely perturb antenna performance. A weather seal gasket 29 is placed on the lip of the antenna holding cup 21 before the antenna cover 30 is secured to the hemispherical dome 25 with antenna cover mounting screws 31. The antenna covers 30 provide an environmental shield for the antennas 26 and are fabricated of structurally reinforced low dielectric polypropylene material. Attachment of the antenna cover mounting screws 31 completes the assembly of the described invention as shown in FIG. 4. At this time, the described invention can be slid over the front of a missile bulkhead 32 and secured in place with assembly mounting screws 33 and O-ring 34.
When constructed and operated as set forth above, the conformal array will provide azimuth and elevation angle of arrival (AOA) information as illustrated in FIGS. 5A and 5B wherein the left figure in each case shows results at one frequency and the right figure in each case shows results at another frequency. The azimuth plots in FIG. 5A show very accurate AOA, particularly within ±40° of boresight, at two different frequencies. The elevation plots of FIG. 5B show very accurate AOA performance, particularly within ±45° of boresight. The theoretical value in FIG. 5B is zero, thus accounting for the failure to see any data graphed in the left figure. These plots are actual measured data of an azimuth scan at zero elevation.
Although a particular arrangement of conformal spiral antenna array has been illustrated for the purpose of describing the manner in which the invention can be applied, it will be appreciated that the invention is not limited as such. FIG. 6 illustrates how the described arrangement can be expanded to provide full forward hemisphere FOV coverage by adding up to six more antennas to include look up, look left and look right arrays in addition to the look ahead and look down capability as described herein. FIG. 6 also illustrates, for example, the described invention supporting alternate mode sensors 35, such as millimeter wave antenna or infrared sensors disposed in the interstices between antennas 36 and preferably at the surface region of the hemisphere 37 to further enhance the operational capability of the described invention. For example, the antenna array composed of antennas 36 can be of the type described hereinabove with reference to FIGS. 1A and 1B whereas the antenna array composed of antennas or sensors 35 can be arranged to operate in the same manner as the array composed of antenna elements, but be designed to sense a form of energy or the like different from that sensed by other antenna array. For example, the first antenna array can be designed to detect standard RF energy to direct the array carrying device to a location close to the target whereupon the second antenna array, which can be infrared sensors or detectors, can be switched in to more accurately locate and/or define the target and perform desired operations against the target as a result of such location and/or definition.
Though the invention has been described with respect to certain particular preferred embodiments thereof, many variations and modification thereof 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.
|
A fixed body wide field-of-view conformal antenna array suitable for broadband precision direction finding on missile platforms. The array is configured as multiple sub-arrays of spiral antennas that cover particular regions within the desired field-of-view of the entire array. A lower cost, more reliable and more accurate direction finding solution for missile needs is provided, primarily by the elimination of conventional radomes and antenna gimbal structures. The array can be configured to include multi-mode sensors.
| 7
|
BACKGROUND OF THE INVENTION
The use of silica gel as a support for catalysts is well known. The silica gel is a colloidal system of solid character comprised of colloidal particles of a condensation polymerized silicic acid in a hydrated state which forms a coherent structure. It is an assembly of small, impervious, dense, roughly spherical (diameter roughly 100 A) particles in a rather open or loose random packing. The particles are believed to be spherical since the gels are not crystalline. It is believed that the spheres are bonded together by bridges or fillets of the same material. The pore system within the aggregate is formed by the open spaces between the elementary particles and the porous texture, as characterized by the specific surface area, pore volume and pore diameter, depends on the size and the packing of the elementary particles. There are generally two forms of silica gel -- xerogel and aerogel.
An aerogel is a gel in which the liquid phase of a gelled silicic acid solution has been replaced by a gaseous phase in such a way as to avoid the shrinkage which would occur if the gel had been dried directly from a liquid. For example, Kistler prepared silica aerogels by replacing most of the water in the gel with alcohol, heating the gel in an autoclave above the critical temperature of the alcohol so that there was no meniscus between the liquid and gas phases, and venting the vapors. In this way, liquid phase was removed without subjecting the gel structure to the compressive forces due to the surface tension of the liquid-gas interface.
Xerogels are prepared by removal of the water by evaporation from an aqueous gelled silicic acid solution. Evaporation of the liquid phase forms menisci in the pores at the surface of the gel so that the surface tension of the liquid exerts a strong compression on the gel mass. The degree to which the gel can be densified depends on the equilibrium between the compression due to the surface tension and the resistance to compression by the gel framework. Compression will increase with smaller pore diameters; resistance to compression depends upon the strength of the gel which increases with higher packing density and more strongly coalesced structures. Thus, gels of high specific surface, made up of extremely small ultimate silica units and formed at low silica concentration, shrink greatly and crack into fragments upon being dried.
Much of the technology of silica gels involves the problem of making a strong hard gel mass which will not shrink or crack upon being dried and which will be suitable as a catalyst base. On the other hand, there has evolved a considerable art in producing extremely light, friable gels which will break down easily into fine powders for use as fillers in plastics, rubber and the like. This type of xerogel is not suitable for fixed bed catalyst supports.
Other solid forms of silica include the crystalline quartz, tridymite and cristabolite, and these are generally not suitable as catalyst supports because, in part, they are non-porous. The same is true of opal, an amorphous form of silica.
Pelleted diatomaceous earth is a naturally occurring form of siliceous material which is sometimes used as a catalyst support because it has a porous structure and is relatively crush-resistant. However, it also contains alumina and iron impurities which may be harmful to many catalytic reactions.
There is a significant amount of technical literature relating to combining a type of hydrothermal treatment of silica gel with its use as a catalyst. For example, Czarny et al, Przem. Chem. 46 (4), 203-207 (1967), studied the effect of water pressure (a hydrothermal treatment) and suggested the use of these gels to study the influence of pore structure on catalytic properties. German Offen. 2,127,649 teaches preparing macroporous silica gel spheres by heating them in steam and aqueous ammonia for 3 hours at 10 bars and the resulting material is reported to be useful for catalytic processes. French Pat. No. 1,585,305, refers to a method for hardening the surfaces of silica gel without degrading its activity or altering its properties using a heat treatment in a lower alcohol vapor with 10% of its volume as water. Schlaffer et al, J.Phys.Chem. 69 (5), 1530-6 (1965), examined the physical changes that occur to silica and alumina gels upon exposure to steam at moderate to high temperatures and found the surface area and pore volume of silica gel to be less stable to prolonged steaming those those of silica-alumina cracking catalysts.
Other technical literature relates to increasing the crushing strength of silica gel by a steam or water treatment. See, e.g., Bodnikov et al, Zh.Prikl.Khim. 38 (10), 2157-65 (1965) and Sultanov, U.S.S.R. Pat. No. 281,431. A number of other papers deal with the steam treatment of silica gel to alter pore characteristics.
German Offen. 2,237,015 relates to a phosphoric acid hydration catalyst supported on a treated silica gel carrier. The silica gel carrier material is treated with steam or a mixture of steam and nitrogen at a temperature of 200°-350° C., preferably 250°-300° C., and a pressure of 30-1500 psig to obtain a material of increased crushing strength.
Although the German Offen. teaches that the steam treatment of silica gel will increase its crushing strength, it is important to note that the crush strength of the gel is not, per se, transferrable to the phosphoric acid impregnated catalyst. For example, a sample of virgin grade 57 ID silica xerogel has an average crush strength of 4.7 pounds with 14% equal to or less than 2 pounds while a phosphoric acid olefin hydration catalyst made from that xerogel has a much lower average crush strength of 2 pounds with 72% ≦ 2 pounds.
I have now found that by steam treating certain silica xerogels, a xerogel of improved crush strength can be obtained which can be used as a support for various catalytic materials and the resulting catalyst will have an improved crush strength and certain other surprising and unexpected advantages which are described in more detail below.
Accordingly, it is the object of this invention to provide a fixed bed supported catalyst having properties superior to that obtained in the prior art. This and other objects of the invention will become apparent to those skilled in the art from the following detailed description.
SUMMARY OF THE INVENTION
This invention relates to a fixed bed supported catalyst and more particularly to a fixed bed supported catalyst in which the support is a silica xerogel which has been treated with steam under certain specific temperature conditions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the preferred embodiments of the present invention, a silica xerogel of improved crush resistance is first prepared and is then impregnated with the active catalytic material. As noted above, xerogels can be produced as strong, hard masses or as extremely light, friable gels. Only the former is suitable for the catalyst of this invention.
Accordingly, the silica gel used to prepare the catalyst of this invention must be either a regular density (RD) or intermediate density (ID) silica xerogel or ID extrudates which are characterized by the following properties:
Martin diameter: 0.5-25.0 mm, preferably 2.0-5.0 mmBulk density: 0.35-0.75 g/cc, prefer- ably 0.42-0.70 g/ccPore volume: 0.40-2.2 ml/g, preferably 0.44-1.15 ml/gBET surface area: 200-900 m.sup.2 /gChemical composition: SiO.sub.2 >99w% (dry basis) Fe.sub.2 O.sub.3 0.01-0.03 w% (dry basis) Na.sub.2 O 0.02-0.09 w% (dry basis) Al.sub.2 O.sub.3 0.4 w% (dry basis)Average crush strength(dry) of 50 particles: >2.0 pounds
The average crush strength of the xerogel is determined with a Chatillon Pellet Strength tester which measures the minimum force necessary to just crush a particle between parallel plates.
Intermediate density xerogels have a bulk density of 0.35-0.48 g/cc, pore volume of 0.80-2.2 ml/g and BET surface area of 200-500 m 2 /g; regular density xerogels have a bulk density of 0.65-0.75 g/cc, pore volume of 0.3-0.5 ml/g and BET surface area of 600-900 m 2 /g. Suitable xerogels are commercially available. Examples of intermediate density materials include grade 57 intermediate density (ID) silica gel manufactured by Davison Chemical Co., Division of W. R. Grace & Co., Baltimore, Md. and 3-12 mesh ID silica gel manufactured by Eagle Chemical Co., Mobile, Alabama. Examples of regular density (RD) xerogels include grade 03 regular density gel manufactured by the Davison Chemical Co.
The silica xerogel particle is placed into a reactor which is then sealed from the atmosphere and purged of air with an inert gas such as nitrogen or the like. The xerogel is exposed to water vapor as it is heated under pressure until the treatment temperature is reached at both the inlet and outlet zones of the reactor. Heating can be accomplished by heating the reactor or by passing a hot flowing inert gas, optionally saturated with water vapor through the reactor. It is important, however, that no liquid water be present.
Once the appropriate temperature and pressure conditions are attained, the gel is steamed for a period of time which can range from 4-16 hours. The water vapor can be used by itself or can optionally be diluted with an inert gas such as nitrogen or ethylene. Total pressure employed will be in the range of 40 psi to 1500 psi and the water vapor will contribute a partial pressure in the range of 40-225 psi. The treatment temperature is at least 149° C. and care is taken not to allow the temperature to attain a level above 300° C. When the xerogel is heated to the treating temperature from ambient temperature, the vapor above the xerogel preferably should be saturated with water up to at least 149° C. Thereafter the xerogel is allowed to cool to ambient temperature or cooling is accelerated by circulation of a cool dry inert gas such as nitrogen through the gel. Ethylene is also satisfactory as a cooling gas. After the gel has been cooled, the reactor is depressurized to atmospheric pressure or below.
Alternatively, the silica xerogel can be charged into a pressure vessel which is then pressurized with an inert gas. The xerogel is then heated while water in the vapor state only is allowed to admix with the inert gas which surrounds the gel. The inert gas is kept saturated with water vapor. This may be accomplished, for example, by initially charging liquid water into the vessel while keeping it separate and out of contact with the xerogel. The reactor is then closed, pressurized and heated externally. In this case, the liquid water is also heated and caused to vaporize, saturating the gas blanket with water vapor at all temperatures. The amount of water can be limited so as to be fully vaporized at treatment temperature. At the end of the treatment, the vessel is depressurized at the treatment temperature, and swept with cool, moist inert gas to cool to ambient temperature without dehydration of the xerogel yet not allowing liquid water condensation on the gel.
The resulting xerogel is characterized by:Martin diameter: 0.5-25.0 mm, preferably 2.0-5.0 mmBulk density: 0.35-0.75 g/cc, prefer- ably 0.42-0.70 g/ccPore volume: 0.40-2.2 ml/g, preferably 0.44-1.15 ml/gBET surface area: 20-800 m 2 /gAverage crush strength(dry) of 50 particles: >4 poundsMechanically stable to aqueous solutions and steamto 350°C.
After the steam treatment, the xerogel is impregnated with the active catalytic material. The xerogel is suitable for supporting a whole spectrum of solid catalysts involving especially elements of Groups I B, II B, IV B, V, VI B, VII B, and VIII of the Periodic Table of the elements appearing at pages 60-61 of Lange's Handbook of Chemistry (Revised 10th Ed.), and more especially the following elements, their salts, their oxides, their acids, their alloys, their heteropolyacids or salts, or any mixtures thereof: Cu, Ag, Au, Zn, Cd, Hg, Ti, Bi, Sb, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, N, P, As, Fe, Co, Ni, Ru, Os, Ir, Rh, Pd, and Pt, with the optional additional impregnation of the support with phosphoric acid solution or I 2 .
These catalysts are useful in a very large number of fixed bed, vapor or mixed gas liquid trickle bed catalytically promoted industrially important reactions including, for example, (1) the oxidation of ethylene to acetic acid, (2) the oxidation of ethylene in the presence of acetic acid to vinyl acetate, (3) the oxidation of propylene in the presence of water to acrylic acid, (4) the oxidation of xylenes to the corresponding aromatic acids, e.g., phthalic, isophthalic, or terephthalic acids, (5) the ammonia oxidation of propene to acrylonitrile, (6) the oxidative dehydrogenation of n-butylene, (7) the reductive amination of nitriles, (8) the oxidation of exhaust gas from internal combustion engines, (9) the hydrogenation of unsaturated compounds, (10) olefin polymerization, (11) oxidation of paraffin hydrocarbons, (12) oxidation of SO 2 to SO 3 , (13) the hydrogenation of phenol to cyclohexanol, (14) oxosynthesis, (15) hydrogenation of nitroso compounds, and (16) the oxidation of ethanol to acetic acid.
The present invention thus opens up the possibility of using regular density or intermediate density silica xerogel granules or extrusions as supports for heretofore non-feasible fixed bed heterogeneous oxidation catalyst compositions which require the use of aqueous and/or alkaline medium in their preparation. As an example, very active oxidation catalysts are prepared by impregnating a support with an aqueous solution of sodium chloropalladite (Na 2 PdC1 4 ) and chloroauric acid (HAuC1 4 ), concentrating that mixture on a support by heat until the granules are free flowing (dry), then immersing the granules in an alkaline formaldehyde solution to reduce the salts to the metals, Pd and Au. The granules are then drained and washed with water containing a trace of acetic acid to wash out chloride ion which is poisonous to oxidation reactions and also to wash out sodium chloride, sodium hydroxide and other impurities. The resulting preparation, when impregnated with aqueous H 3 PO 4 is catalytically active in the oxidation of ethylene to acetic acid. However, non-steam treated regular density xerogel disintegrates in the presence of aqueous solutions and thus can neither be impregnated from nor washed with aqueous solutions. Furthermore, it becomes gelatinous in the presence of alkaline solutions.
The presence of alkali has been found to be very beneficial in the reduction of the palladium salt with several possible reducing agents such as sodium borohydride, hydrogen, hydrazine, hydroxylamine, CO, NH 3 or alcohols. However, alkaline solutions cause decrepitation of nonsteamed intermediate density gels and causes them to become gelatinous and completely unsuitable as fixed bed catalyst supports. Extrusions made from powdered intermediate density silica gels are also greatly weakened when exposed to alkaline solutions.
Pre-treatment of the regular density of the intermediate density granules and extrusions with steam at elevated temperatures and pressures causes them to become mechanically stable to aqueous solutions and to alkaline solutions and thus suitable for supports in preparing the aforementioned catalysts. There is thus made available catalysts on silica gel supports which are characterized by high specific pore volumes such as the intermediate density silica xerogels or high specific surface areas such as the regular density silica xerogels. There is an added advantage from the steam treatment of an adequate crush strength for the finished catalysts.
A variety of methods can be used for the deposition depending on the finished catalyst desired. In one method suitable for the deposition of metals, mixtures of metals and alloys of metals such as noble metals, oxides and salts of metals or mixtures of oxides or metals with oxides, a soluble precursor or mixed precursor of the catalytic materials are dissolved in an appropriate volatile solvent and the steam treated silica xerogel impregnated with the resulting solution, drained and then the solvent evaporated until the gel is in a state of near dryness. The precursors are then converted to the final catalytic material by the following treatments singularly or in combination: drying, reduction, hydrogenation, oxidation, alkali or acid treatment, or thermal decomposition. The gel may then be washed with a suitable solvent, if required, to remove undesirable ions or soluble extraneous material and then dried under relatively mild conditions. The gel can also then be impregnated, if desired or required, with phosphoric acid or other catalytic liquid and dried to produce the final catalyst.
In some instances, it may be advantageous to pretreat the steam treated xerogel with an alkaline or acid solution prior to catalyst deposition.
In another method, solutions of the catalytic materials or their precursors may be sprayed into the steam treated silica gel particles as they are being tumbled and dried in a rotating vessel.
The steaming process, catalyst impregnation process, and catalytic reaction can be performed in the same reactor or in separate reactors as desired.
Electron micrographs of silica gel show that the physical structure can be described as a coherent aggregate of elementary particles of roughly spherical shape having a diameter of the order of 100 A. The elementary particle is an irregular three dimensional network of SiO 4 tetrahedra, each silicon atom being linked to four oxygens and each oxygen being linked to two silicons. At certain sites, the elementary particles may be linked together by Si-O-Si bridges. The particle surface is covered with hydroxyl groups which are responsible for the hydrophilic nature of normal silica gel.
The steaming process involves a vapor phase transport of matter resulting in the growth of large elementary particles at the expense of small ones, and resulting in the enlargement of the pores and loss in surface area. The transport of solid material during steaming results in the formation of fillets between the particles by deposition of the material in the regions of contact. Undoubtedly, this contributes to the enhanced crush strength of the gel. The transport of material from a small elementary particle to a larger one is of molecular character. The silica gel skeleton is not affected during this process and, therefore, the pore volume does not change.
The change also results in the increased resistance to crushing of the dry xerogel granule and of the xerogel granule impregnated with the active catalyst.
It will be recognized that the discussion above relates to the theory behind the invention. It has been set forth to assist in understanding the nature of this invention but I do not wish to be limited thereby.
With respect to xerogel granules, the effect of the steam treatment of the instant invention on mechanically strengthening regular density xerogel is even more marked than for the intermediate density xerogel. The intermediate density xerogels become gelatinous but do not shatter or disintegrate on immersion in aqueous solution or alkaline solutions, while non-steamed regular density silica xerogel granules do so shatter or disintegrate.
The following Examples are set forth to further illustrate the invention but are not intended to limit it. Unless otherwise specified, all parts and percentages are by weight and all temperatures are in degrees centigrade unless otherwise specified.
EXAMPLE 1
A sample of intermediate density silica xerogel granules having particles retained on 6 mesh screen (U.S. Standard Sieve Series) and manufactured by the Davison Chemical Co. having the following properties:
Grade 57 ID gelAverage crush strength (lbs) 2.5Pore volume (cc/g) 1.04Surface area (m.sup.2 /g) 350Average pore diameter (A) 120Total volatile (wt.%-ca 955° C) 4.5Bulk density (lbs/ft.sup.3) 27SiO.sub.2 (wt.%-dry basis) 99.5Fe (wt.%-dry basis) 0.02Na.sub.2 O (wt.%-dry basis) 0.09
was placed in a glass liner which was then inserted in a 250 ml stainless steel autoclave. 9 ml of liquid water were placed in the bottom of the autoclave but outside the liner. The autoclave was then closed and electrically heated externally with a heating jacket to 270° C. and held at that temperature under the autogeneous steam pressure developed for 64 hours. The autoclave was then cooled to room temperature, opened, and the steam treated gel removed. The average crush strength had increased to 6.5 lbs.
The treated xerogel was coated with palladium and gold metals to give approximately 1% Pd and about 0.5% Au by impregnating the xerogel with a solution of a palladium salt and chloroauric acid, followed by reduction to the metals with an aqueous, alkaline solution of formaldehyde.
5 g of the catalyst thus prepared were placed in one arm of a 6 long × 1/2 inch inner diameter glass tube and rested on a plug of glasswool on the bottom. The tube was immersed in an oil bath at 140° C. and subjected to a flow of oxygen containing 15% ethylene and saturated with glacial acetic acid at 75° C. (by bubbling the gas through glacial acetic acid) using a flow rate of 2 liters per hour and a pressure of 10 psig. The exit gas was passed through a cold trap at about -70° C. to condense the liquid.
Analysis showed the production rate of vinyl acetate from the 5 g of catalyst for the first 5 days to be 7.3, 7.5, 7.6, 7.5 and 7.3 mmol/hr, respectively.
EXAMPLE 2 (Comparison)
An attempt was made to repeat the preparation of the catalyst in Example 1 by depositing the metals on the same silica gel without the steaming treatment. The gel disintegrated into a soft, plastic, gelatinous mass after contacting with the aqueous alkaline solution containing formaldehyde.
EXAMPLE 3
150 ml of cylindrically shaped extrusions of grade 57 ID xerogel fines measuring 1/8 inch diameter and from 1/8 inch to about 3/4 inch long, (SMR 7-3741; Davison Chemical Co.), 300 m 2 /g surface area, were placed in a glass liner which were then inserted into a 250 ml stainless steel autoclave. 10 ml of liquid water was placed in the autoclave outside the liner. The autoclave was closed and heated electrically to 280° C. for 16 hours under the autogeneous steam pressure developed after which the autoclave was cooled and opened. The steamed extrusions were then coated with palladium and gold as described in Example 1. The resulting catalyst was employed to oxidize ethylene in the presence of acetic acid and oxygen to vinyl acetate by the procedure described in Example 1. The production rate of 5 g of catalyst for the first 5 days was 8.25, 8.46, 8.45, 8.49 and 8.24 mmol/hr of vinyl acetate, respectively.
EXAMPLE 4 (Comparison)
An attempt was made to repeat the preparation of the catalyst of Example 3 using the same xerogel extrusions without the steam treatment. A gelatinous mass resulted when the alkaline reducing reagent was used and the material was unsuitable for fixed bed catalytic use.
EXAMPLE 5
The catalyst prepared in Example 1 was converted into a catalyst for oxidizing ethylene to acetic acid by impregnating it with a phosphoric acid solution prepared from 4.16 parts of 85% H 3 PO 4 and 13.6 parts deionized water, followed by drying until the granules tumbled freely as the catalyst was tumbled in an open, slowly rotating, glass dish under a flow of hot air generated by a heat gun. The H 3 PO 4 impregnated catalyst was placed in a reactor through which was passed a gas mixture of ethylene, oxygen and water vapor in a volume ratio of 5:1:4, respectively, at 150° C. and 50 psi and an hourly vapor space velocity of 298 volumes reactant gas to 1 volume catalyst. The ethylene and oxygen were catalytically converted to acetic acid and acetaldehyde; 75% of the oxygen was converted to acetic acid with a selectivity of 56% and to acetaldehyde with a selectivity of 6% and to CO 2 with a selectivity of about 23%; each of the selectivities being based on the total ethylene reacted.
EXAMPLE 6
A sample of regular density xerogel granules (grade 03 RD gel - Davison Chemical Co.), retained on an 8 mesh screen, and having the following properties:
Average crush strength 8.2 lbsBET surface area (m.sup.2 /g) 800Pore volume (cc/g) 0.45Average pore diameter (A) 22Total volatile (wt.%-ca 955° C) 6.0Bulk density (g/cc) 0.69Composition (wt.%-dry basis) SiO.sub.2 99.7 Fe 0.03 Na.sub.2 O 0.02
was placed in a glass liner which was then inserted into a 250 ml stainless steel autoclave. 10 ml of liquid water were placed in the bottom of the autoclave but outside the liner. The autoclave was closed and externally heated electrically to 270° C. and held at that temperature under the autogeneous steam pressure developed for 16 hours. The autoclave was then cooled to room temperature, opened and the steam treated xerogel removed. The average crush strength had increased to 12.6 lbs.
The steam treated RD xerogel was then coated with Pd and Au as described in Example 1.
EXAMPLE 7 (Comparison)
An attempt was made to repeat the preparation of the catalyst of Example 6 using the same regular density xerogel granules but without the steam treatment. The attempt failed because the gel disintegrated when it was immersed in the coating solution and then changed to a soft, gelatinous mass when contacted with the aqueous alkaline solution containing formaldehyde.
EXAMPLE 8
60.72 g of extruded 1/8 inch diameter and about 3/4 inch long ID silica xerogel having a specific surface area of 300 m 2 /g and a pore volume of 0.45 cc/g (SMR 7-3741; Davison Chemical Co.) was placed in a glass liner which was then placed in a 250 ml Magna-Dash stainless steel autoclave. 10 ml of liquid water was placed in the autoclave outside the liner and the autoclave was closed. The reactor was then heated to 280° C. and held there under the autogeneous steam pressure developed for 17 hours, after which the autoclave was cooled to ambient temperature, the extrudate removed and vacuum dried at 100° C. for 2.5 hours. The final weight of the xerogel extrudate was 58.21 g.
A catalyst was prepared containing 1% Pd and 0.5% Au using an aqueous alkaline formaldehyde solution to reduce the palladium and gold to the metals. 30 ml of the catalyst were treated with 20 ml of a solution prepared by diluting 2.57 g of 85% H 3 PO 4 to 20 ml, and then dried on a rotating glass dish under a stream of hot air to produce the final catalyst.
The 30 ml of final catalyst was placed in a reactor and used to catalytically oxidize propylene to acrylic acid at 195° C. at atmospheric pressure using a mixed gas composed of propylene at a feed rate of 10 cc/min, air at a feed rate of 178 cc/min and water vapor at a feed rate of 160 cc/min, the latter being achieved by passing the air and propylene mixture through water at 80° C. After a run of 28 hours, acrylic acid was produced at a rate of 24.8 mmol/liter catalyst/hour.
EXAMPLE 9 (Comparison)
An attempt was made to prepare the catalyst of Example 8 from the same silica xerogel extrudate within a steam treatment. The attempt failed because the treatment with the aqueous alkaline formaldehyde reducing agent caused the extrudate to change into a soft, gelatinous mass which was unsuitable as a fixed bed catalyst.
EXAMPLE 10
A sample of regular density xerogel silica gel granules (grade 03 RD gel - Davison Chemical Co.), retained on an 8 mesh screen, and having the following properties:
Average crush strength (lbs) 8.2Pore volume (cc/g) .45Surface area (m.sup.2 /g) 800Average pore diameter (A) 22Total volatile (wt.%-ca 955° C) 6.0Bulk density (lbs/ft.sup.3) 43SiO.sub.2 (wt.%-dry basis) 99.7Fe (wt.%-dry basis) 0.03Na.sub.2 O (wt.%-dry basis) 0.03
was placed in a glass liner which was then inserted into a 250 ml stainless steel autoclave. 10 ml of liquid water were placed in the bottom of the autoclave but outside the liner. The autoclave was closed and externally heated electrically to 270° C. and held at that temperature under the autogeneous steam pressure developed for 16 hours. The autoclave was then cooled to room temperature, opened and the steam treated xerogel removed. The average crush strength had increased to 12.6 lbs.
The steam treated regular density xerogel was then coated with Pd.
The catalyst is used in the continuous mixed liquid-gas phase trickle bed catalytic hydrogenation of N-nitrosodimethylamine (NDMA) to unsymmetrical dimethylhydrazine (UDMH) as follows.
200 ml (140.5 g) of the catalyst are charged to a jacketed stainless steel reactor which is then closed. Oil at 26° C. is circulated through the jacket to keep the bed at that temperature. The reactor is flushed with nitrogen, then hydrogen, then pressured to 60 psig with hydrogen.
The feed entering into the reactor above the bed consists of hydrogen gas and an anaerobic solution of 20% N-nitrosodimethylamine in oxygen-free water. The latter is fed into the reactor at a rate of about 60 gal/ft 3 catalyst/hour.
Pressure is maintained at 60 psi by hydrogen under higher pressure entering through a valve controlled by a pressure transmitter located at a port at the top of the reactor above the bed and an associated controller. It is thus fed at the rate it is consumed.
Liquid product is removed through a valve located below the bed and controlled by a differential pressure cell and associated controller so as to maintain a liquid level at a point below the catalyst bed.
Under steady state conditions, a substantial proportion of the N-nitrosodimethylamine is hydrogenated to unsymmetrical dimethylhydrazine.
EXAMPLE 11
A vertically mounted jacketed stainless steel reactor is charged with 200 ml (140.5 g) of a catalyst prepared from regular density xerogel silica gel granules as in Example 10, closed, then hot oil is circulated through the jacket to heat the catalyst bed to and maintain it at 125° C.
A preheated (125° C.) pressurized gaseous mixture comprised of 64.1 parts by weight nitrogen, 19.5 parts by weight oxygen and 16.4 parts by weight ethanol is pumped continuously into the top of the reactor from where it passes through the catalyst bed at 75 psi pressure, and during which the ethanol is continuously catalytically oxidized in vapor phase to acetic acid, acetaldehyde and CO 2 . The reacted gas mixture passes out of the bottom of the reactor through a valve where pressure is let down to atmospheric. That valve is controlled with a pressure transmitter (connected to a port at the top of the reactor above the bed) together with a controller to maintain reaction pressure at 75 psi. Acetic acid and acetaldehyde are condensed to liquid state by cooling the effluent gas stream to 0° C. in a condenser.
Feed rates in mmol/hr of nitrogen, oxygen and ethanol are 591, 157 and 92, respectively, and product rates in mmol/hr for acetic acid, acetaldehyde and CO 2 are 71, 2.7 and 36.5, respectively.
Various changes and modifications can be made in the process and products of this invention without departing from the spirit and the scope thereof. For example, the catalysts of this invention can also be used in a moving bed. The various embodiments disclosed herein were for the purpose of further illustrating the invention but were not intended to limit it.
|
An improved fixed bed catalyst is disclosed and comprises the active catalyst material supported on a particular type of porous silica xerogel which has been treated with steam under particular temperature conditions.
| 2
|
This is a divisional application of Ser. No. 07/746,170 filed Aug. 14, 1991, now U.S. Pat. No. 5,153,691, which is a continuation of application Ser. No. 07/631,208, filed Dec. 21, 1990, now abandoned, which is a continuation of application Ser. No. 07/369,134, filed Jun. 21, 1989, now abandoned.
FIELD OF THE INVENTION
The present invention relates generally to nonvolatile memory cells and more particularly to a memory cell having a dielectric layer with two different thicknesses formed between two conducting layers and wherein field emission tunneling is caused to occur through the lesser dielectric thickness.
BACKGROUND OF THE INVENTION
Integrated circuit memory devices have been developed which store data for indefinite periods of time and which also have the capability of selectively changing the data stored. Of particular interest here is a nonvolatile memory device which utilizes a memory cell which is completely surrounded by a relatively thick insulating material or dielectric and is thus termed a "floating gate". Nonvolatile memory cells may be arranged, as is known in the art, to construct nonvolatile random access memories (NOVRAMs) and electrically erasable programmable read-only memories (EEPROMs). U.S. Pat. Nos. 4,300,212 and 4,486,769, for example, disclose a NOVRAM and an EEPROM, respectively.
Some EEPROMs made with the so called "thin oxide" technology utilize relatively thin layers of insulating silicon dioxide with two different thicknesses. However, EEPROMs made with this technology have a region of ultra thin (80 to 150 Angstroms) dielectric through which bi-directional tunneling occurs between a smooth single crystal surface and a polysilicon layer.
The fabrication of a memory cell typically consists of depositing and patterning layers of polysilicon with layers of insulating oxide in between. Patterning may be done using conventional photolithographic techniques well known in the industry. More specifically, the first polysilicon layer is formed and patterned on a first dielectric layer formed on silicon substrate. A second dielectric layer is then formed to completely surround the first polysilicon layer and to form a tunneling oxide on the surface of the first polysilicon layer. A second polysilicon layer is formed and patterned on top of the second dielectric layer. A third dielectric layer is formed on the second polysilicon layer such that the second polysilicon layer is completely surrounded by dielectric. A third polysilicon layer is then formed and patterned on top of the third dielectric layer. Finally, a fourth dielectric layer is deposited over the entire memory cell.
Typically, the first polysilicon layer is a programming electrode, the second polysilicon layer is the floating gate, and the third polysilicon layer is an erase electrode. The floating gate generally lies between the programming electrode and the erase electrode and partially overlies the former and is itself partially overlain by the latter. Beneath and insulated from the floating gate is the substrate. In one configuration, there is an electrically isolated bias electrode disposed in the substrate of opposite conductivity to the substrate. This bias electrode forms one plate of a coupling capacitor to the floating gate and is also referred to as a metallurgical "paddle". In another configuration there is no metallurgical paddle disposed in the substrate.
Programming, erasing, and retaining information on the floating gate is achieved by controlling the flow of electrons to and from the floating gate. Since the polysilicon layers are insulated from each other by the layers of oxide, the electrons must "tunnel" either from the programming electrode to the floating gate or from the floating gate to the erase electrode. The electron tunneling is controlled by the relative potentials between the electrodes and the floating gate.
The floating gate voltage operating window is defined to be the difference between the positive potential on the floating gate when the floating gate has been erased and the level of negative potential on the floating gate when the floating gate has been programmed. Favorable operating conditions are obtained when this operating window is large and remains large. As the device is alternately programmed and erased, the size of the operating window decreases, thereby shortening the remaining usable lifetime of the device. Thus, a continuing objective of floating gate devices is to increase the operating window size and to maintain that increased window size for a greater number of program and erase cycles, thereby increasing the useful lifetime of the device.
A generally desirable objective of most semiconductor devices is miniaturization. As devices become smaller, however, any misalignment of the polysilicon layers will produce changes in the capacitance between the layers which adversely affects the operation of the device.
Accordingly, it is an object of the present invention to provide a memory cell which reduces alignment sensitivity between polysilicon layers by forming a second thicker dielectric layer between the polysilicon layers in all areas except for those regions where tunneling is to occur.
It is a further object of the present invention to provide a memory cell having less sensitivity to variations in alignment or dimensions of various cell elements (linewidths) thereby providing an improved floating gate memory cell operating window over a wide range of processing variations.
It is yet a further object of the present invention to provide a memory cell having an improved operating window thereby lowering the operating voltage requirements and providing a tighter distribution of the voltages required to operate an array of memory cells.
SUMMARY OF THE INVENTION
The present invention comprises a method for forming a semiconductor integrated circuit device comprising the steps of (a) forming a first conducting layer, (b) forming an insulating layer of a predetermined second thickness on a top surface of the first conducting layer, the formation of the insulating layer resulting in the top surface of the first conducting layer being microtextured, (c) forming a masking layer having a predetermined pattern on a top surface of the insulating layer thereby forming a pattern in the insulating layer so as to expose predetermined regions of the first conducting layer, (d) under-cutting the insulating layer by an etching process a predetermined amount interior to the edge boundaries of the masking layer, (e) etching the first conducting layer according to the predetermined pattern defined by the masking layer, (f) forming a second insulating layer on all exposed surfaces of the first conducting layer, the second insulating layer having first and second regions of different predetermined thicknesses, and (g) forming a second conducting layer over the third insulating layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view of a dual thickness interpoly oxide floating gate nonvolatile memory cell according to the present invention.
FIG. 2 is a schematic of an equivalent circuit describing the operation a floating gate nonvolatile memory cell according to the present invention.
FIGS. 3(a) and 3(b) are schematic cross-sectional views of aligned mirrored memory cells according to the present invention and misaligned mirrored memory cells, respectively.
FIGS. 4(a) to 4(f) are schematic cross-sectional views of a process to form a dual thickness dielectric layer according to the present invention.
FIGS. 5(a) to 5(d) illustrate an example of the improvement to the floating gate memory window according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A schematic cross-sectional view of a dual thickness interpoly oxide as applied to a paddleless floating gate nonvolatile memory cell according to the present invention is shown in FIG. 1 at 100. A programming electrode 110 is formed from a first polysilicon layer (poly 1), a floating gate 120 is formed from a second polysilicon layer (poly 2), and an erase electrode 130 is formed from a third polysilicon layer (poly 3). The layers are separated from each other and from substrate 140 by layers of dielectric material such as silicon dioxide. The portion of the dielectric layer between the floating gate 120 and the programming electrode 110 is a tunneling element 101 and the portion of dielectric between the erase electrode 130 and the lower portion of the floating gate 120 is a tunneling element 102. The capacitances of tunneling elements 101 and 102 are denoted by C 21 and C 32 , respectively. The capacitance between floating gate 120 and substrate 140 is denoted by C 2S (the "steering capacitance"). A ground terminal 150 is disposed in substrate 140 proximate programming electrode 110 and a bit line terminal 160 is disposed in substrate 140 proximate erase electrode 130.
By suitably treating the conducting layers, the surfaces of the floating gate and the programming electrode are microtextured to produce curved surfaces which enhance the electric field locally. This local field enhancement creates the high fields necessary to cause Fowler-Nordheim field emission tunneling with relatively low voltages applied across the tunneling dielectric. For example, a 1000 angstrom silicon dioxide layer grown on a polished single crystal substrate typically tunnels when 80-100 volts is applied across it. A similar 1000 angstrom oxide formed on textured polysilicon typically tunnels when only 10 to 20 volts is applied across the oxide. It is this field enhancement due to the localized curvature or microtexturing of the surface of the polysilicon layer that allows a relatively thick dielectric layer to be used in the present invention. These locally curved or microtextured regions may be formed on the top surface or edge surfaces of the polysilicon layers depending on the type of processes, including oxidation, following the polysilicon deposition. The amount of curvature or microtexturing is adjusted through the ensuing processes to set the desired voltage at which tunneling occurs.
An equivalent circuit describing the memory cell of FIG. 1 is shown in FIG. 2. The potentials of the polysilicon layers are given by V P1 (for poly 1), V FG (for the poly 2 floating gate), and V P3 (for poly 3). The tunneling elements are shown schematically as 201 and 202. The poly layers each form the gates of a field effect transistor with poly 3 forming the gate of a transistor 230, poly 2 forming the gate of transistor 220, and poly 1 forming the gate of transistor 210. The channel regions of these transistors 210, 220, and 230 are formed within the surface 142 of substrate 140 (as shown in FIG. 1). The bit line voltage V BIT 260, ground 250, and capacitances C 21 , C 32 , and C 2S are also shown.
The floating gate voltage operating window (also known as the memory window) is defined to be the difference between the positive potential on the floating gate when the floating gate has been erased and the level of negative potential on the floating gate when the floating gate has been programmed. Based on FIG. 2, the floating gate voltage after writing may be approximately expressed as: ##EQU1## for the erased state where (V FG ) E is the erase state floating gate voltage and (V FG ) P is the program state floating gate voltage and where V P1 and V P3 are the potentials used during the write operation. The summation over j in Equation (1) extends over the parasitic capacitances that are "seen" by the floating gate and can be cut off at any desired number depending on significance of the terms. A typical value for j is 6. Equations (2) and (3) are derived considering only the capacitance terms shown, assuming all other capacitances are sufficiently small to be ignored. The steering capacitance C 2S for this paddleless case is assumed to have the full metallurgical capacitance value of the floating gate to the substrate for the programmed state and to approach zero for the erased state. These conditions are further assumed to hold for both write and read operations. The tunneling voltages (voltages across the tunneling elements necessary to maintain the required tunneling currents during write operations) are assumed to be equal and of a value that is half of the total voltage applied between poly 3 and poly 1 during a write operation.
A memory cell with a paddle typically has a bias electrode disposed in, and of opposite conductivity to, the substrate region beneath the floating gate and the store electrode. If the capacitance between the floating gate and the paddle is given by C 2M and the remaining part of the steering capacitance is comprised of non-metallurgical channel capacitance, given by C 2C , the equations for the programmed and erased states floating gate voltages are given by ##EQU2## where C TOT =C 21 +C 32 +C 2M +C 2C , and where V BIT is the bitline voltage.
Equations (4) and (5) were derived assuming that only those capacitances appearing are significant. C 2M is also assumed to be much larger than C 2C , and that for the programmed state, C 2C is only half of its full metallurgical capacitance value, and is its full capacitance value otherwise. This assumption has been found to reasonably describe observed behavior. The tunneling voltages across each of the tunneling elements are also assumed to be equal and of a value equal to half of the total voltage applied between poly 3 and poly 1 during write (just as in the paddleless case).
Since the size of the memory window is just the erased state potential minus the programmed state potential, subtracting Equation (4) from Equation (5) gives the size S of the memory window. ##EQU3## where the expression (C 2M +1/4C 2C )/C TOT is known as the "Capacitance Coupling Efficiency."
Equation (6) shows that the size of the memory window is directly proportional to the capacitance coupling efficiency.
Thus, in order to maximize the size of the memory window of a memory cell, it is desirable to make the capacitance coupling efficiency as close to 100% as possible. That is, C 2M and C 2C should be much larger than C 32 and C 21 .
Thus, one way to increase the size of the memory window is to decrease the values of capacitances C 32 and C 21 . This can be achieved by increasing the thickness of the dielectric layers in all areas except in the regions of the first and second polysilicon layers where enhanced field emission electron tunneling is desired. Since the tunneling element capacitances C 32 and C 21 are sensitive to the thickness of the dielectric between the first and second polysilicon layers, the program/erase window will be increased if the thickness of the dielectric layers overlaying programming electrode 110 and floating gate 120 are increased.
A thicker dielectric layer also reduces the alignment sensitivity between the polysilicon layers. A thicker oxide layer means a reduced per unit area capacitance which results in a floating gate cell operating window which is less sensitive to misalignment.
In arrays of memory cells, the cells are typically mirrored around electrical contact lines. Misalignment of polysilicon layers may occur during fabrication of the cells. Aligned mirrored memory cells according to the present invention and misaligned mirrored memory cells are shown in FIGS. 3(a) and 3(b), respectively.
As shown in FIG. 3(b), the second polysilicon layer is misaligned by an amount given by ΔL. This change of relative dimension results in an increase or decrease of the corresponding interpoly capacitance. There are various components of interpoly capacitance in semiconductor devices. Of interest here is the so-called variable capacitance arising from the planar interpoly region. This capacitance is strongly dependent on misalignment. The capacitance of the planar region (flat plate capacitance) is given by: ##EQU4## where W=the width of the polysilicon overlap region
L=the length of the overlap region
t ox =the thickness of the interpoly oxide
e ox =the dielectric constant of the oxide
Utilization of a thicker dielectric oxide for a significant portion of the planar region between the polysilicon layers thus decreases the total interpoly capacitance by reducing the flat plate capacitance. It likewise reduces the sensitivity of the capacitance to misalignment (dC/dL).
Under one case of misalignment conditions of the second polysilicon layer to the first and the third layer to the second, the capacitance of one tunneling element will grow while the other shrinks. This results in a shift of the center of the operating window which is given approximately by: ##EQU5## and where V TUN is the tunneling voltage across the tunnel elements and ΔC 21 and ΔC 32 are the change in respective capacitances due to misalignment.
The shift in the operating window center occurs for the following reason. During a write operation the first polysilicon layer and the third polysilicon layer capacitively pull in opposite directions (e.g., -3 volts and +25 volts) while during read, they capacitively pull in the same direction (e.g., both go to +5 volts). Consequently, any capacitance imbalance due to misalignment will result in a floating gate memory window shift and this shift does not get compensated by the read operation bias conditions. Since in an array of memory cells the cells are mirrored around the electrical contact lines, this means that every other row of cells will have window shifts in one direction, while the other rows of cells will window shift in the opposite direction. Reference cells which track misalignment may ameliorate the situation, but there is a limit to the reference cell approach which occurs when the window is shifted so far negatively that an erased state floating gate voltage is too low to provide the necessary sensing current, or when the window shift is so positive that program cell conduction is excessive.
The dual thickness thick insulating layer of the present invention thus achieves distinct advantages over prior art. For satisfactory levels of electron transmission to occur, some means must exist for enhancing the Fowler-Nordheim emission from the pertinent surface of the emitting conducting layer. The present invention preferably utilizes such a means comprising the formation of a microtextured surface on the emitting conducting layer. Other means for enhancing field emission by the pertinent conducting layer will be clear to those skilled in the semiconductor arts and thus are within the scope of the present invention. An example of such a means is enhanced emission from regions of the conducting layer with localized curvature, such as at corners or indentations on the surface thereof.
A process to form a dual thickness dielectric layer according to the present invention is illustrated using cross-sectional views in FIGS. 4(a) to 4(f). FIG. 4(a) shows a substrate 440 which has already undergone various conventional processing steps. Grown on top of substrate 440 is a gate oxide layer 445 of a predetermined thickness to provide the appropriate capacitance between substrate 440 and a first polysilicon layer 410 which is deposited on top of gate oxide layer 445. A thick interpoly oxide layer 450 is formed on first polysilicon layer 410. Conventional oxide layers are approximately 550 Angstroms thick. In the preferred embodiment of the present invention, thick oxide layer 450 is at least double the thickness of a conventional oxide layer. For example, the thickness of thick oxide layer 450 can be greater than or equal to 1400 Angstroms. Thick oxide layer 450 may be formed, for example by low-pressure chemical vapor deposition or thermal oxidation. In forming thick oxide layer 450 on first polysilicon layer 410, the surface of the latter becomes microtextured, producing locally curved surfaces which enhance the electric field locally such that enhanced field emission tunneling is enabled to occur from the surface of the polysilicon layer 410. A photoresist layer 460 is applied to thick oxide layer 450 in a conventional manner. FIG. 4(b) shows a conventional anisotropic oxide etch step wherein thick oxide layer 450 (of FIG. 4(a)) is etched according to a pattern established by photoresist layer 460 to form thick oxide layer 451.
FIG. 4(c) shows the step of under-cutting thick oxide layer 451 (of FIG. 4(b)) with respect to the overlying photoresist layer 460. This under-cutting is performed using conventional wet or plasma oxide etch techniques to form an under-cut thick oxide layer 452. The undercut can be uniformly done and is easily reproducible. The amount of under-cut is several times the thickness of the thick oxide layer according to the present invention. For example, the under-cut can be 0.2 to 0.3 microns. FIG. 4(d) shows the next step of the anisotropic etch of first polysilicon layer 410 (of FIGS. 4(a) to 4(c)) to form first polysilicon layer 411 which is sized to conform to the desired specifications of the memory cell being fabricated. Note that the boundaries of the photoresist layer 460 define the boundaries of etched polysilicon layer 411. Photoresist 460 (of FIGS. 4(a) to 4(d)) is then removed. FIG. 4(e) shows the process for forming tunneling oxide layers 470 by forming an insulating oxide layer over the exposed regions of first polysilicon layer 411 and first gate oxide layer 445. This results particularly in an insulating oxide layer on the shoulders of first polysilicon layer 411 contiguous with under-cut thick oxide layer 452. Note that thick oxide portion 452 can be masked during formation of oxide layer 470 or its thickness increased when layer 470 is formed, in a manner conventional in the art. Oxide layers 470 are formed so as to have a predetermined thickness that is much less than the thickness of oxide layer 450 (e.g., approximately 450 Angstroms versus 1400 Angstroms). This approach allows the precise control of the critical dimensions of the tunneling regions according to the present invention. A second polysilicon layer 420 is deposited over under-cut thick oxide layer 452, tunneling regions 470, and gate oxide layer 445 in a conventional manner as shown in FIG. 4(f).
Experimentation has shown that the increased thickness of thick oxide layer 452 reduces nominal interpoly capacitance C 32 by approximately 40% and nominal interpoly capacitance C 21 by approximately 25%. This results in two significant improvements.
First, the nominal floating gate memory window margin (erased state voltage minus program state voltage) is improved by approximately 1 volt, which is approximately an 18% improvement in memory window size. Second, memory cells fabricated according to the present invention have reduced sensitivity to misalignment by approximately a factor of 2. For example, if the interpoly oxide is four times thicker, the window center shift is only one-fourth that produced by a thinner oxide for the same misalignment. This is a result of the reduced per unit area capacitance which produces a memory window center which is less sensitive to misalignment.
An example of the improvement on the floating gate memory window is illustrated in FIGS. 5(a) to 5(d). The + and - signs denote the cell and its mirror image. FIG. 5(a) shows the values of the various capacitances as a function of poly 2 misalignment (L) for the case of a single thickness oxide layer. Capacitor C2S- is shown at 511, capacitor C21- is shown at 512, capacitor C32- is shown at 513, capacitor C2S+ is shown at 514, capacitor C21+ is shown at 515 and Capacitor C332+ is shown at 516 in FIG. 5(a). FIG. 5(b) shows the capacitances according to the present invention. In FIG. 5(b), capacitor C2S- is shown at 521, capacitor C21- is shown at 522, capacitor C32- is shown at 523, capacitor C2S+ is shown at 524, capacitor C21+ is shown at 525 and capacitor C32+ is shown at 526. As can be seen, the capacitances C21, C32 according to the present invention are almost all smaller for the entire range of misalignment shown. These decreased capacitances produce a larger floating gate memory window as a function of misalignment as shown in FIGS. 5(c) and 5(d). FIGS. 5(c) and 5(d) show the floating gate voltages for the erased and programmed states of the mirrored cells for the single thickness oxide case and the dual thickness oxide of the present invention. In FIG. 5(c) ERASE- is shown at 531, PROGRAM- is shown at 532, ERASE+ is shown at 533 and PROGRAM+ is shown at 534. In FIG. 5(d), ERASE- is shown at 541, PROGRAM- is shown at 542, ERASE+ is shown at 543 and PROGRAM+ is shown at 544. Recall that the memory window is just the erased state voltage minus the programmed state voltage. It can be seen that the present invention increases the memory window size for all values of misalignment.
By reducing the interpoly capacitances with respect to the steering capacitance, the alignment sensitivity of the memory window is reduced. This allows for the use of lower write voltages to achieve comparable memory window size for a given range of misalignment or to allow more relaxed alignment tolerances for a given write voltage.
An improved nonvolatile memory cell and a process for manufacturing same has been described. It will be appreciated by those skilled in the art that the present invention is applicable to similar devices based upon electron tunneling and controlled capacitances, and that the present invention is to be limited solely by the scope of the following claims.
|
A semiconductor integrated circuit device is disclosed having first and second conducting layers, with the first layer having a shape which enhances field emission tunneling off of the surface thereof. A dual thickness dielectric layer separates the conducting layers. When a potential difference is applied between the conducting layers, field emission tunneling occurs primarily through the thinner portion of the dielectric layer. A method for forming a semiconductor integrated circuit device comprises the steps of (a) forming a first conducting layer, (b) forming regions of enhanced field emission on said first conducting layer, (c) forming a second insulating layer on the first conducting layer, (d) forming a masking layer (e) undercutting the second insulating layer, (f) etching the first conducting layer according to the masking pattern, (g) forming a third insulating layer on all exposed surfaces of the first conducting layer, such that a resultant insulating layer has first and second regions of different thicknesses, and (h) forming a second conducting layer over said resultant insulating layer.
| 8
|
FIELD OF THE INVENTION
The present invention relates to compositions containing a peptide for therapeutic treatment of ocular conditions, including dry eye disease.
BACKGROUND OF THE INVENTION
Dry eye disease is a condition where the tear film loses water and becomes more concentrated, which can cause a corresponding rise in tear osmolarity. This increased osmolarity can result in symptoms such as a sandy-gritty feeling in the eye, burning, irritation, or a foreign-body sensation. As set forth in US Patent Application No. 2003/0203849, dry eye patients have been increasing in recent years with spread of use of contact lenses and increase in a VDT-operation.
Also as reported in US Patent Application No. 2003/0203849, lacrimal fluid serves other functions in addition to prevention of dry eye, such as, protection of cornea and conjunctiva, bacteriostatic action, prevention of infection with bacteria, fungus, virus and the like, feeding of oxygen and a variety of nutritions to cornea and removal of a carbon dioxide gas and metabolites therefrom, dilution and removal of harmful stimuli in the case where cornea and conjunctiva injured, transportation of liquid components such as epidermal growth factors which participate in wound healing and the like and hematocyte components such as fibronectin and the like to the injured portion, retainment of cornea and a conjunctival epithelial cell, regulation of wound healing.
As set forth in U.S. Patent Application No. 2005/0025810, dry eye disease may result from a number of s the following factors: (i) the disease may be a natural part of the aging process, affecting 15%-20% of adults over age 40; (ii) the disease may result from pathological processes such as diseases of the lacrimal glands, mucus glands, and/or lipid producing glands, and may occur with cell infiltration or atrophy of the lacrimal gland (Sjögren's syndrome); and (iii) estrogen deficiency in postmenopausal women may result in dry eye disease.
The proteinase-activated receptor-2 (PAR-2) is a G-protein-coupled receptor that is activated by proteolytic cleavage of the amino terminus extracelular domain, which unmasks a tethered peptide ligand that auto activates the receptor. PAR-2 is activated by trypsin and mast cell tryptase (see, e.g., Nystedt, et al., Eur J. Biochem 232(1):84-89 (1995); Bohm, et al., Biochem J 314, 1009-1016 (1996); and Molino, et al., J. Biol Chem 272(7):4043-49(1997)), as well as by synthetic peptides corresponding to the first amino acids of the receptor's tethered ligand: SLIGKV-NH 2 (human sequence) or SLIGRL-NH 2 (“SLIGRL”; mouse and rat sequence which is actually more potent than the human sequence for PAR-2 activation).
PAR-2 is expressed in many tissues, including the human cornea and human corneal epithelial cell lines (see, R Lang et al, Invest Ophthalmol Vis Sci. 44(1):99-105 (2003)). PAR-2 activity has been associated with inflammatory reactions in many tissues (see, e.g., Steinhoff et al, J Neurosci. 16;23(15):6176-80 (2003), Seeliger, et al., FASEB J. 17(13):1871-85(2003), and Uehara, et al., J Immunol 170(11):5690-96 (2003)).
PAR-2 activation in corneal epithelial cells induce intracellular calcium rise followed by pro-inflammatory cytokines release (R Lang et al, Invest Ophthalmol Vis Sci. 44(1):99-105 (2003)). PAR-2 activation by SLIGRL was shown to induce Tear Secretion in Rats (Nishikawa H et al, J Pharmacol Exp Ther. 2005 January ;312(1):324-31). US Patent Application No. 2003/0203849 discloses the use of the peptide SLIGRL, which activates PAR-2, for promoting tear secretions.
Mucin1 is one of the mucins expressed in the ocular surface (see Gibson, Exp Eye Res. 78(3)379-88 (2004)). Since ocular surface drying diseases also alter mucin production, it is expected that studies of mucin gene regulation may yield treatment modalities for these diseases (see Gibson, Exp Eye Res. 78(3)379-88 (2004)).
Applicants have unexpectedly found that the peptide LIGR induces the expression of the mucin1 gene in corneal epithelial equivalents. Applicants have found that unlike SLIGRL, the peptide LIGR does not induce calcium mobilization, and does not induce the secretion of inflammatory mediators, so the peptide is not activating PAR-2 like SLIGRL. Moreover, since LIGR is not inducing the secretion of inflammatory mediators, the peptide could be more useful in the treatment of dry eye conditions.
SUMMARY OF THE INVENTION
In one aspect, the present invention features a method to treat ocular conditions, such as dry eye, in a mammal comprising intraocularly administering a composition including a peptide of the formula
R 1
>A 1 -A 2 -A 3 -A 4 -R 3
R 2
A 1 is Val, Leu, Ile, or Cha; A 2 is Val, Leu, Ile, or Cha; A 3 is Gly or Ala; A 4 is Lys, Arg, or Har; each R 1 and R 2 , independently, is H, C 1-12 alkyl, C 7-10 phenylalkyl, or C(═O)E 1 , where E 1 is C 1-20 alkyl, C 3-20 alkenyl, C 3-20 alkynyl, phenyl, 3,4-dihydroxyphenylalkyl, naphthyl, or C 7-10 phenylalkyl; provided that when either R 1 or R 2 is C(═O)E 1 , the other must be H; and R 3 is OH, NH 2 , C 1-12 alkoxy, C 7-10 phenylalkoxy, C 11-20 naphthylalkoxy, C 1-12 alkylamino, C 7-10 phenylalkylamino, or C 11-20 naphthylalkylamino;
or a cosmetically acceptable salt thereof.
Other features and advantages of the present invention will be apparent from the detailed description of the invention and from the claims
DETAILED DESCRIPTION OF THE INVENTION
It is believed that one skilled in the art can, based upon the description herein, utilize the present invention to its fullest extent. The following specific embodiments are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Also, all publications, patent applications, patents, and other references mentioned herein are incorporated by reference. Unless otherwise indicated, a percentage refers to a percentage by weight (i.e., % (W/W)).
Definitions
What is meant by “treat dry eye” is means the treatment (e.g., complete or partial alleviation or elimination of symptoms of dry eye) and/or prevention or inhibition of the symptoms of dry eye. Such treatment includes, but is not limited to, promoting lacrimal secretion.
As used herein, “intraocularly administering” means directly laying on or spreading on or around the eye, e.g., by use of the hands or an applicator such as a wipe, a contact lens, a dropper, or a spray.
As used herein, “cosmetically-acceptable” means that the peptides, other ingredients, carrier, or compositions which the term describes are suitable for use in contact on or around the eye without undue toxicity, incompatibility, instability, irritation, allergic response, and the like.
As used herein, “safe and effective amount” means an amount of the peptide or composition sufficient to treat the ocular condition, such dry eye, but low enough to avoid serious side effects. The safe and effective amount of the compound or composition will vary with the condition of the eye being treated, the age of the end user, the duration and nature of the treatment, the specific compound or composition employed, the particular cosmetically-acceptable carrier utilized, and like factors.
Peptides
The composition of the present invention comprises a peptide of the formula
R 1
>A 1 -A 2 -A 3 -A 4 -R 3
R 2
wherein:
A 1 is Val, Leu, Ile, or Cha; A 3 is Val, Leu, Ile, or Cha; A 4 is Gly or Ala; A 5 is Lys, Arg, or Har; each R 1 and R 2 , independently, is H, C 1-12 alkyl, C 7-10 phenylalkyl, or C(=O)E 1 , where E 1 is C 1-20 alkyl, C 3-20 alkenyl, C 3-20 alkynyl, phenyl, 3,4-dihydroxyphenylalkyl, naphthyl, or C 7-10 phenylalkyl; provided that when either R 1 or R 2 is C(=O)E 1 , the other must be H; and R 3 is OH, NH 2 , C 1-12 alkoxy, C 7-10 phenylalkoxy, C 11-20 naphthylalkoxy, C 1-12 alkylamino, C 7-10 phenylalkylamino, or C 11-20 naphthylalkylamino;
or a cosmetically acceptable salt thereof.
In one embodiment, R 1 and R 2 , which are bound to the N-terminus of the peptide, are both H. In another embodiment, R 1 is H and R 2 is C(=O)E 1 (e.g., palmitoyl, oleatoyl, or stearatoyl).
Examples of peptides of the present invention include, but are not limited to H 2 -Leu-Ile-Gly-Arg-NH 2 (Peptide 1, SEQ ID NO:1), H 2 -Leu-Ile-Gly-Lys-NH 2 (SEQ ID NO:2), H 2 -Leu-Ile-Gly-Arg-OH (SEQ ID NO:3), H 2 -Leu-Ile-Gly-Lys-OH (SEQ ID NO:4), Palmitoyl-Leu-Ile-Gly-Arg-NH 2 (SEQ ID NO:5), Palmitoyl-Leu-Ile-Gly-Lys-NH 2 (SEQ ID NO:6), Palmitoyl-Leu-Ile-Gly-Arg-OH (SEQ ID NO:7), Palmitoyl-Leu-Ile-Gly-Lys-OH (SEQ ID NO:8), Stearatoyl-Leu-Ile-Gly-Arg-NH 2 (SEQ ID NO:9), Stearatoyl-Leu-Ile-Gly-Lys-NH 2 (SEQ ID NO:10), Stearatoyl-Leu-Ile-Gly-Arg-OH (SEQ ID NO:11), and Stearatoyl-Leu-Ile-Gly-Lys-OH (SEQ ID NO:12), or a cosmetically-acceptable salt thereof.
The symbol A 1 , A 2 , or the like used herein stands for the residue of an alpha-amino acid. Such symbols represent the general structure, —NH—CH(X)—CO— or ═N—CH(X)—CO— when it is at the N-terminus or —NH—CH(X)—CO— when it is not at the N-terminus, where X denotes the side chain (or identifying group) of the alpha-amino acid, e.g., X is —CH(CH 3 ) 2 for Val. Note that the N-terminus is at the left and the C-terminus at the right in accordance with the conventional representation of a polypeptide chain. R 1 and R 2 are both bound to the free nitrogen atom N-terminal amino acid and the R 3 is bound to the free carboxyl group of the C-terminal amino acid.
“Cha” herein refers to cyclohexylalanine, “2,3-diap” refers to 2,3-diaminoproprionic acid, and “Har” refers to homoarginine. Furthermore, where the amino acid residue is optically active, it is the L-form configuration that is intended unless the D-form is expressly designated. An alkyl group, if not specified, contains 1-12 carbon atoms.
The peptide of the invention can be provided in the form of cosmetically acceptable salts. Examples of preferred salts are those with therapeutically acceptable organic acids, e.g., acetic, palmitic, oleic, stearic, lactic, maleic, citric, malic, ascorbic, succinic, benzoic, salicylic, methanesulfonic, or pamoic acid, as well as polymeric acids such as tannic acid or carboxymethyl cellulose, and salts with inorganic acids such as the hydrohalic acids (e.g., hydrochloric acid), sulfuric acid or phosphoric acid.
The amount of peptide present in the composition will depend on the peptide used. The peptide typically will be present in the composition in an amount from about 0.001% to about 10% by weight, in particular in an amount from about 0.01% to about 5% by weight.
The method for synthesizing peptides of the present invention are well documented and are within the ability of a person of ordinary skill in the art. See, e.g., Bodanszky M, Int J Pept Protein Res 25(5):449-74 (1985), Fmoc Solid Phase Peptide Synthesis, eds. Chan, W. & White, P. (Oxford University Press, 2000), and Chemical Approaches to the Synthesis of Peptides and Proteins, Lloyd-Williams, P. et al. (CRC Press, 1997).
Topical Compositions
On or more of the peptides may be administered in a topical composition for treatment of dry eye. In one embodiment, the peptide is formulated for topical administration to stimulate tear production by administration of a composition containing the peptide. The composition may be applied once or more times a day.
Forms of the composition include, but are not limited to, solutions, ointments, ophthalmic inserting agents, gels, emulsions, suspensions and the like. In one embodiment, modifications such as sustained-releasing, stabilizing, or easy-absorbing properties may be further applied to such the preparations. In one embodiment, the composition is sterilized, for example, by filtration through a microorganism separating filter, heat sterilization, or the like.
In one embodiment, the peptide is contained in an aqueous-based cream excipient. In one embodiment, the cream composition is applied to the eye at bedtime, but it may be applied any time throughout the day. In another embodiment, the peptide is formulated as a solution or suspension and is applied topically in the form of eye drops.
In one embodiment, the composition contains a buffer, such as a borate buffer.
The peptide may also be administered by injection. Examples of injections include, but are not limited to, intravitreal administration (injection into the vitreous), subconjunctival injection (injection into the subconjunctiva), or retrobulbar injection (injections behind the eyeball).
For long-term delivery of the peptide, a matrix composition containing the peptide may be implanted into the eye. In one embodiment, a surgically implanted matrix composition may be a reservoir container having a diffusible wall (e.g., of polyvinyl alcohol or polyvinyl acetate) containing quantities of the peptide. In one embodiment, quantities of the peptides may be incorporated into a polymeric matrix composition made of a polymer such as polycaprolactone, poly(glycolic) acid, poly(lactic) acid, or a polyanhydride, or a lipid such as sebacic acid. Such a matrix composition may be implanted on the sclera or in the eye. In one embodiment, the matrix composition may be implanted intraocularly to result in sustained release of the peptide over a period of time.
In one embodiment, the composition contains the peptide in an alginic acid matrix between membranes which are controlled releasing membranes of an insoluble ethylene-vinyl acetate copolymer. Such a composition can placed inside eyelids.
In addition, additives such as solvents, bases, solution adjuvants, suspending agents, thickening agents, emulsifying agents, stabilizing agents, buffering agents, isotonicity adjusting agents, soothing agents, preservatives, corrigents, flavoring agents, coloring agents, excipients, binding agents, lubricants and the like can be added to a preparation, depending on the dosage forms (known dosage forms such as solutions, ointments, ophthalmic inserting agents, gels, emulsions, suspensions, solid eye drops and the like). Additionally, various additives such as pH adjusting agents, gelling agents, solubilizing agents, surfactants, absorption-promoting agents, dispersing agents, preservatives, solubilizing agents and the like can be used.
In one embodiment, the composition can be applied to an eye drop for contact lens, a washing solution for contact lens, a preserving solution for contact lens, or a contact lens composition.
When the composition of the present invention is used as the eye drop for contact lens, the washing solution for contact lens and the preserving solution for contact lens, a surfactant may be incorporated therein. Non-limiting examples of surfactants includes nonionic surfactants such as polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene/polyoxypropylene-substituted ethylenediamine, Polysorbate 80, polyoxyethylene hydrogenated castor oil, polyoxyethylenestearate and the like, amphoteric surfactants such as alkylpolyaminoethyl glycine and the like, and anionic surfactants such as alkylbenzene sulfonate, alkyl sulfate and the like and, among them, nonionic surfactants are the most preferable in light of safety to eyes. An amount of the surfactant to be incorporated may be from about 0.001 to about 5%, by weight, such as from about 0.01 to about 1%, by weight.
The eye drop for contact lens, the washing solution for contact lens and the preserving solution for contact lens having a generally used composition may be used, and the additives to be used therein may be properly selected from the additives described above for the ophthalmic preparation for topical administration. The eye drop for contact lens, the washing solution for contact lens and the preserving solution for contact lens may be produced according to the method similar to that as described above for the ophthalmic preparation for topical administration.
In one embodiment, a drug-sustained releasing contact lens may be produced in which the composition for promoting lacrimal secretion of the present invention is retained in and/or adhered to a contact lens. The contact lens may be produced using the known materials, for example materials for water-containing soft ophthalmic lens as described in U.S. Pat. No. 5,817,726, 2-hydroxyethyl methacrylate polymers as described in U.S. Pat. No. 5,905,125, ophthalmic lens materials as described in European Patent Application No. 781,777, molded ophthalmic collagen gels as described in Japanese Patent Application No. 11-197234, the hydrogel lens which is coated with a lipid layer in advance as described in U.S. Pat. No. 5,942,558. Additionally, known materials such as methacrylic acid ester polymers, copolymers of oligosiloxanylalkyl(meth) acrylate monomers/methacrylic acid ester monomer and the like may be used.
Generally used contact lens such as hard or rigid cornea-type lens, and gel, hydrogel or soft-type lens which are produced from the above known materials may be used.
The sustained-releasing contact lens may be produced, for example, by incorporating in or adhering to the contact lens the composition for promoting lacrimal fluid secretion of the present invention according to the known methods for producing the drug sustained-releasing contact lens as described in Japanese Patent Application No. 11-24010 and U.S. Pat. Nos. 5,658,592 and 6,027,745. Specifically, the drug sustained-releasing contact lens may be produced by adhering to a part of the contact lens a finely-divided or gel drug sustained-releasing agent which is prepared from a component which activate PAR-2 and polymers such as polyvinyl pyrrolidone, sodium hyaluronate and the like. In addition, the drug sustained-releasing contact lens may be produced by forming a drug reservoir such as by producing a contact lens from a member which forms a front surface of the lens and a member which forms a rear surface of the lens. Also, the contact lens of the present invention may be produced according to the known methods for producing the drug sustained-releasing contact lens other than those described above.
Additional Active Agents
In one embodiment, the topical composition further comprises other active agents in addition to the peptides for treatment of dry eye, including, but not limiting to, anti-infective agents, antibiotics, antiviral agents, anti-inflammatory drugs, antiallergic agents, vasoconstrictors, vasodilators, local anesthetics, analgesics, intraocular pressure-lowering agents, immunoregulators, anti-oxidants, vitamins and minerals, and the like
Examples of anti-infective agents include, but are not limited to, silver, iodine and the like.
Examples of antibiotics include, but are not limited to, aminoglucosides, quinolones, macrolides, cephems, and sulfa drugs such as sulfamethoxazole, sulfisoxazole, sulfisomidine, sulfadiazine, sulfadimethoxine, sulfamethoxypyridazine.
Examples of antivirals include, but are not limited to, famciclovir, penciclovir, and acyclovir.
Examples of nonsteroidal anti-inflammatory drugs include, but are not limited to, indomethacin, diclofenac, pranoprofen, tiaprofenic acid, and tolfenamic acid. Examples of steroidal anti-inflammatory drugs include, but are not limited to, prednisolone. Examples of other anti-inflammatories include, but are not limited to, dipottasium glycyrrhizinate, allantoin, ε-aminocaproic acid, berberine chloride, berberine sulfate, sodium azulenesulfonate, zinc sulfate, zinc lactate, and lysozyme chloride.
Examples of antiallergics include, but are not limited to, ketotifen, oxatomide, cetirizine, sodium cromoglicate.
Examples of antihistamines include, but are not limited to, mequitazine, chlorpheniramine maleate, diphenhydramine hydrochloride.
Examples of vasoconstrictors include, but are not limited to, naphazoline, tetrahydrozoline, oxymethazoline, phenylephrine, ephedrines, and epinephrine.
Examples of local anesthetics include, but are not limited to, lidocaine hydrochloride, procaine hydrochloride, and dibucaine hydrochloride.
Examples of immunmodulators include, but are not limited to, cylcosporin A and tacrolimus.
Examples of vitamins include, but are not limited to, vitamin A, vitamin C, vitamin E (e.g. alpha-, beta-, gamma-, or delta-tocopherols and tocotrienols), vitamin B 1 , B 2 , B 6 , and B 12 . In addition, other vitamins such as nicotinates, pantothenates, biotin and the like can be used.
Examples of anti-oxidants include, but are not limited to, vitamins such as vitamin A and vitamin C.
The present invention will be further illustrated below by way of Examples, but the present invention is not limited thereto.
EXAMPLE 1
LIGR Induces the Expression of Mucin 1 (MUC1) in Corneal Epithelial Equivalents
Human corneal equivalents were purchased from SkinEthic Laboratories (Nice, France). Equivalents were allowed to equilibrate in SkinEthic growth medium overnight at 5% CO 2 , and were then treated with SLIGRL (SEQ.ID.NO.17) (200 μM), LIGR (SEQ.ID.NO.1) (200 μM) or Phosphate buffered saline (PBS) as a control. Treatment was refreshed everyday. At the end of the 6 th day, equivalent samples were harvested. Total RNA was extracted from the equivalents using RNAqueous™ kit (Ambion, Austin, Tex.) according to manufacture's instructions. RNA samples were then treated with DNA-free kit (Ambion, Austin Tex.). 25 nanograms of total RNA from each sample were amplified using OneStep RT-PCR kit (Qiagen, Valencia, Calif.) according to the manufacture's instructions. PCR Primers were synthesized by Integrated DNA Technologies (Coralville, Iowa). Primer sequences are listed in table 1. Each RT-PCR reaction contained 30 pmol of each primer of MUC1 or 10 pmol of each primer of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Each PCR cycle consisted of denaturing for 50 seconds at 94° C., annealing for 1 minutes at 58° C., elongation for 1 minute at 72° C. The PCR products were resolved by electrophoresis in 1% agarose gel and stained with ethidium bromide. Kodak Gel logic 100 imaging system was used to take gel pictures and analyze product band density.
TABLE 1 Cycle Gene Forward Primer Reverse Primer number MUC1 cgtcgtggacattgatggtacc ggtacctcctctcacctcctccaa 33 (SEQ.ID.NO 13) (SEQ.ID.NO 14) GAPDH accacagtccatgccatcac tccaccaccctgttgctgta 27 (SEQ.ID.NO 15) (SEQ.ID.NO 16)
The quantified results of the RT-PCR amplification are shown in Table 2. All sample densities were normalized against GAPDH.
TABLE 2 Treatment Fold Change (MUC1:GAPDH) Untreated 1 SLIGRL 0.7 LIGR 2.1
These results demonstrate that LIGR, but not SLIGRL, induced the expression of the MUC1 gene.
EXAMPLE 2
SLIGRL But Not LIGR Induces Inflammatory Mediators
Human primary neonatal keratinocytes were purchased from Cascade Biologics (Portland, Oreg.). Cells were cultured in Media 154 supplemented with human keratinocytes growth supplement (Cascade Biologics) and were maintained at <80% confluency. Cells were plated at 6×10 4 per well in 24 well plate and allowed to attach to the well overnight with 5% CO 2 . Cells were then treated with LIGR (50 μM), SLIGRL (50 μM), the control, scrambled peptide ISLLRG (SEQ.ID.NO.18) (50 μM) or left untreated. Each treatment was done in triplicates. 24 hours later, cell media were collected and examined for the expression and secretion of the inflammatory mediators PGE2, PGF2α, IL-8 and IL-6. PGE 2 and PGF 2α , using ELISA kits (Cayman Chemicals, Ann Arbor, Mich.) according to manufacturer's instructions. IL-8 and IL-6 levels were detected using Beadlyte Human Multi-cytokine Detection System (Upstate Cell Signaling Solutions, Lake Placid, N.Y.) according to manufacturer's instructions. The experiment was repeated 4 times with different lots of primary keratinocytes. Data of one representative study are shown in Table 3. As shown in Table 3, SLIGRL, the known PAR-2 activator, induces 1.5-3 times increase in the expression and secretion of several inflammatory mediators. LIGR and the control, scrambled peptide did not induce these inflammatory mediators. This suggests that LIGR is acting in a manner that is different from the PAR-2 activating peptide SLIGRL, and is not associated with inflammation.
TABLE 3
Fold change in the secretion of inflammatory mediators
PGE2
PGF2α
IL-8
IL-6
Unt.
1
1
1
1
SLIGRL
2.3
1.5
3.0
2.7
LIGR
0.8
0.9
1.0
1.2
ISLLRG
0.8
1.0
1.0
1.1
EXAMPLE 3
SLIGRL But Not LIGR Induces Inflammatory Mediators In Vivo
SKH1 hairless mice, were purchased from Charles River (Kingston, N.Y.), and were housed in appropriately sized cages in an environmentally controlled room with a 12-hour light—12-hour dark photoperiod and supplied with food and water ad libitum. Mice were either untreated, or treated with LIGR or SLIGRL (From California Research Peptide Research Inc. Napa, Calif.), at 100 μM, in 70:30 ethanol: propylene glycol vehicle, once daily for 2 weeks (M-F, no treatment on weekends). Following ten days of treatment, mice were sacrificed and skin samples were processed for RNA extraction and RT-PCR. The treated skins were analyzed for the expression of Cyclooxygenase-2 (COX-2), a known inflammatory mediator. Total RNA (25 ng) from each sample was subjected to one step RT-PCR reaction using OneStep RT-PCR Kit (QIAGEN®, Valencia, Calif.) according to manufacturer's instructions. The reverse transcription was carried out for 30 minutes at 50° C. and a hot start of 15 minutes at 95° C. was then included to activate HotStarTaq™ DNA polymerase in the reaction mix. PCR Primers were synthesized by Integrated DNA Technologies (Coralville, Iowa). Primer sequences are listed in table 4. Each RT-PCR reaction contained 30 pmol of each primer of COX-2 or 10 pmol of each primer of GAPDH. Each PCR cycle consisted of denaturing for 50 seconds at 94° C., annealing for 1 minute at 58° C., elongation for 1 minute at 72° C. The PCR products were resolved by electrophoresis in 1% agarose gel and stained with ethidium bromide. Kodak Gel logic 100 imaging system was used to take gel pictures and analyze product band density.
TABLE 4 Cycle Gene Forward Primer Reverse Primer number COX-2 AGAAGGAAATGGCTGCAGAA GCTCGGCTTCCAGTATTGAG 33 GAPDH ACCACAGTCCATGCCATCAC TCCACCACCCTGTTGCTGTA 27
The results of this study are shown in Table 5, as expressed in the ratio of COX-2 expression to the expression of the housekeeping gene GAPDH. As shown in Table 5, COX-2 expression is increased by SLIGRL, but not by LIGR. This in vivo study further supports that LIGR is not a classic PAR-2 activator, and is not inducing pro-inflammatory mediators under physiological conditions.
TABLE 5
Treatment
COX-2:GAPDH
Untreated control
0.353
SIGRL
1.168
LIGR
0.275
EXAMPLE 3
SLIGRL But Not LIGR Induces Intracellular Ca 2+ Influx
HaCaT cells were seeded in a black-wall 96-well plate at about 20,000 cells/100 μl/well and grown overnight in culture medium prior to the experiment. On the day of the experiment, cells were loaded with 100 μl of Calcium Plus assay reagent component A (FLEXstation calcium Plus Assay Kit, Molecular Devices, Sunnyvale, Calif.) prepared in Hanks' Balanced Salt Solution (HBSS, Mediatech, Inc., Herndon, Va.) for 30 minutes according to the manufacturer's protocol. After loading the cells, SLIGRL, LIGR and ISSLRG (at 5× concentration in 50 μl) were added to all wells (final volume 250 μl/well), and intracellular Ca 2+ levels were subsequently assayed using the FLIPR system (Molecular Devices, Sunnyvale, Calif.) to simultaneously monitor fluorescence in all wells (Wavelength−excitation=488 nm, Wavelength−emission=510 nm) according to the manufacture's protocol. The fluorescence intensity was captured every 3 seconds for the first 3 minutes after the addition of the peptides. The results of this study are shown in Table 6, in fluorescence units. As shown in Table 6, SLIGRL induces a dose dependent increase in intracellular calcium mobilization, using 4-40 μM peptide. However, LIGR, as well as the control, scrambled peptide, do not induce intracellular calcium mobilization even at concentrations as high as 800 μM. This example further demonstrates that LIGR is not activating PAR-2 like SLIGRL.
TABLE 6
Fluorescence intensity
Concentration
Scrambled
(μM)
SLIGRL
LIGR
peptide
4
1386.9
—
—
8
1904.015
—
—
20
2003.095
—
—
40
2842.92
628.27
535.54
200
—
424.315
—
400
—
—
744.95
800
—
556.105
—
It is understood that while the invention has been described in conjunction with the detailed description thereof, that the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the claims.
|
The present invention relates to methods to treat dry eye in a mammal by intraocularly administering a composition comprising a peptide.
| 2
|
RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 13/838,839 (now U.S. Pat. No. 8,623,710), filed Mar. 15, 2013, which is a continuation of U.S. patent application Ser. No. 13/732,205 (now U.S. Pat. No. 8,624,386), filed Dec. 31, 2012, which is a continuation of U.S. patent application Ser. No. 13/286,558 (now U.S. Pat. No. 8,358,004), filed Nov. 1, 2011, which is a continuation of U.S. patent application Ser. No. 13/111,537 (now U.S. Pat. No. 8,121,331), filed May 19, 2011, which is a continuation of U.S. patent application Ser. No. 11/741,881 (now U.S. Pat. No. 8,018,049), filed Apr. 30, 2007, which is a divisional of U.S. patent application Ser. No. 10/921,747 (now U.S. Pat. No. 7,434,305), filed Aug. 19, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 09/886,854 (now U.S. Pat. No. 7,166,910), filed Jun. 21, 2001, which claims the benefit of U.S. Provisional Patent Application No. 60/253,543, filed Nov. 28, 2000. U.S. patent application Ser. No. 13/668,035, filed Nov. 2, 2012, U.S. patent application Ser. No. 13/668,103, filed Nov. 2, 2012, U.S. patent application Ser. No. 13/732,120, filed Dec. 31, 2012, U.S. patent application Ser. No. 13/732,179, filed Dec. 31, 2012, U.S. patent application Ser. No. 13/732,205, filed Dec. 31, 2012, and U.S. patent application Ser. No. 13/732,232, filed Dec. 31, 2012, are also continuations of U.S. patent application Ser. No. 13/286,558 (now U.S. Pat. No. 8,358,004). These applications are hereby incorporated by reference herein in their entireties for all purposes.
TECHNICAL FIELD
This patent relates generally to a housing for a transducer. More particularly, this patent relates to a silicon condenser microphone including a housing for shielding a transducer.
BACKGROUND OF THE INVENTION
There have been a number of disclosures related to building microphone elements on the surface of a silicon die. Certain of these disclosures have come in connection with the hearing aid field for the purpose of reducing the size of the hearing aid unit. While these disclosures have reduced the size of the hearing aid, they have not disclosed how to protect the transducer from outside interferences. For instance, transducers of this type are fragile and susceptible to physical damage. Furthermore, they must be protected from light and electromagnetic interferences. Moreover, they require an acoustic pressure reference to function properly. For these reasons, the silicon die must be shielded.
Some shielding practices have been used to house these devices. For instance, insulated metal cans or discs have been provided. Additionally, DIPs and small outline integrated circuit (SOIC) packages have been utilized. However, the drawbacks associated with manufacturing these housings, such as lead time, cost, and tooling, make these options undesirable.
SUMMARY OF THE INVENTION
The present invention is directed to a silicon condenser microphone package that allows acoustic energy to contact a transducer disposed within a housing. The housing provides the necessary pressure reference while at the same time protects the transducer from light, electromagnetic interference, and physical damage. In accordance with an embodiment of the invention a silicon condenser microphone includes a transducer and a substrate and a cover forming the housing. The substrate may have an upper surface with a recess formed therein allowing the transducer to be attached to the upper surface and to overlap at least a portion of the recess thus forming a back volume. The cover is placed over the transducer and includes an aperture adapted for allowing sound waves to reach the transducer.
Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a first embodiment of a silicon condenser microphone of the present invention;
FIG. 2 is a cross-sectional view of a second embodiment of a silicon condenser microphone of the present invention;
FIG. 3 is a cross-sectional view of a third embodiment of a silicon condenser microphone of the present invention;
FIG. 4 is a cross-sectional view of the third embodiment of the present invention affixed to an end user circuit board;
FIG. 5 is a cross-sectional view of the third embodiment of the present invention affixed to an end user circuit board in an alternate fashion;
FIG. 6 is a plan view of a substrate to which a silicon condenser microphone is fixed;
FIG. 7 is a longitudinal cross-sectional view of a microphone package of the present invention;
FIG. 8 is a lateral cross-sectional view of a microphone package of the present invention;
FIG. 9 is a longitudinal cross-sectional view of a microphone package of the present invention;
FIG. 10 is a lateral cross-sectional view of a microphone package of the present invention;
FIG. 11 is a cross-sectional view of a top portion for a microphone package of the present invention;
FIG. 12 is a cross-sectional view of a top portion for a microphone package of the present invention;
FIG. 13 is a cross-sectional view of a top portion for a microphone package of the present invention;
FIG. 14 a is a cross-sectional view of a laminated bottom portion of a housing for a microphone package of the present invention;
FIG. 14 b is a plan view of a layer of the laminated bottom portion of FIG. 14 a;
FIG. 14 c is a plan view of a layer of the laminated bottom portion of FIG. 14 a;
FIG. 14 d is a plan view of a layer of the laminated bottom portion of FIG. 14 a;
FIG. 15 is a cross-sectional view of a bottom portion for a microphone package of the present invention;
FIG. 16 is a cross-sectional view of a bottom portion for a microphone package of the present invention;
FIG. 17 is a cross-sectional view of a bottom portion for a microphone package of the present invention;
FIG. 18 is a cross-sectional view of a bottom portion for a microphone package of the present invention;
FIG. 19 is a plan view of a side portion for a microphone package of the present invention;
FIG. 20 is a cross-sectional view of a side portion for a microphone package of the present invention;
FIG. 21 is a cross-sectional view of a side portion for a microphone package of the present invention;
FIG. 22 is a cross-sectional view of a side portion for a microphone package of the present invention;
FIG. 23 is a cross-sectional view of a microphone package of the present invention;
FIG. 24 is a cross-sectional view of a microphone package of the present invention;
FIG. 25 is a cross-sectional view of a microphone package of the present invention;
FIG. 26 is a cross-sectional view of a microphone package of the present invention;
FIG. 27 is a cross-sectional view of a microphone package of the present invention with a retaining ring;
FIG. 28 is a cross-sectional view of a microphone package of the present invention with a retaining wing;
FIG. 29 is a cross-sectional view of a microphone package of the present invention with a retaining ring;
FIG. 30 is a plan view of a panel of a plurality of microphone packages; and
FIG. 31 is a plan view of a microphone pair.
DETAILED DESCRIPTION
While the invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail several possible embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.
The present invention is directed to microphone packages. The benefits of the microphone packages disclosed herein over microphone packaging utilizing plastic body/lead frames include the ability to process packages in panel form allowing more units to be formed per operation and at much lower cost. The typical lead frame for a similarly functioning package would contain between 40 and 100 devices connected together. The present disclosure would have approximately 14,000 devices connected together (as a panel). Also, the embodiments disclosed herein require minimal “hard-tooling” This allows the process to adjust to custom layout requirements without having to redesign mold, lead frame, and trim/form tooling.
Moreover, many of the described embodiments have a better match of thermal coefficients of expansion with the end user's PCB, typically made of FR-4, since the microphone package is also made primarily of FR-4. These embodiments of the invention may also eliminate the need for wire bonding that is required in plastic body/lead frame packages. The footprint is typically smaller than that would be required for a plastic body/lead frame design since the leads may be formed by plating a through-hole in a circuit board to form the pathway to the solder pad. In a typical plastic body/lead frame design, a (gull wing configuration would be used in which the leads widen the overall foot print.
Now, referring to FIGS. 1-3 , three embodiments of a silicon condenser microphone package 10 of the present invention are illustrated. Included within silicon microphone package 10 is a transducer 12 , e.g. a silicon condenser microphone as disclosed in U.S. Pat. No. 5,870,482 which is hereby incorporated by reference and an amplifier 16 . The package itself includes a substrate 14 , a back volume or air cavity 18 , which provides a pressure reference for the transducer 12 , and a cover 20 . The substrate 14 may be formed of FR-4 material allowing processing in circuit board panel form, thus taking advantage of economies of scale in manufacturing. FIG. 6 is a plan view of the substrate 14 showing the back volume 18 surrounded a plurality of terminal pads.
The back volume 18 may be formed by a number of methods, including controlled depth drilling of an upper surface 19 of the substrate 14 to form a recess over which the transducer 12 is mounted ( FIG. 1 ); drilling and routing of several individual sheets of FR-4 and laminating the individual sheets to form the back volume 18 , which may or may not have internal support posts ( FIG. 2 ); or drilling completely through the substrate 14 and providing a sealing ring 22 on the bottom of the device that will seal the back volume 18 during surface mounting to a user's “board” 28 ( FIGS. 3-5 ). In this example, the combination of the substrate and the user's board 28 creates the back volume 18 . The back volume 18 is covered by the transducer 12 (e.g., a MEMS device) which may be “bumpbonded” and mounted face down. The boundary is sealed such that the back volume 18 is operably “air-tight.”
The cover 20 is attached for protection and processability. The cover 20 contains an aperture 24 which may contain a sintered metal insert 26 to prevent water, particles and/or light from entering the package and damaging the internal components inside; i.e. semiconductor chips. The aperture 24 is adapted for allowing sound waves to reach the transducer 12 . The sintered metal insert 26 will also have certain acoustic properties, e.g. acoustic damping or resistance. The sintered metal insert 26 may therefore be selected such that its acoustic properties enhance the functional capability of the transducer 12 and/or the overall performance of the silicon microphone 10 .
Referring to FIGS. 4 and 5 the final form of the product is a silicon condenser microphone package 10 which would most likely be attached to an end user's PCB 28 via a solder reflow process. FIG. 5 illustrates a method of enlarging the back volume 18 by including a chamber 32 within the end user's circuit board 28 .
Another embodiment of a silicon condenser microphone package 40 of the present invention is illustrated in FIGS. 7-10 . In this embodiment, a housing 42 is formed from layers of materials, such as those used in providing circuit boards. Accordingly, the housing 42 generally comprises alternating layers of conductive and non-conductive materials 44 , 46 . The non-conductive layers 46 are typically FR-4 board. The conductive layers 44 are typically copper. This multi-layer housing construction advantageously permits the inclusion of circuitry, power and ground planes, solder pads, ground pads, capacitance layers and plated through holes pads within the structure of the housing itself. The conductive layers provide EMI shielding while also allowing configuration as capacitors and/or inductors to filter input/output signals and/or the input power supply.
In the embodiment illustrated, the housing 42 includes a top portion 48 and a bottom portion 50 spaced by a side portion 52 . The housing 42 further includes an aperture or acoustic port 54 for receiving an acoustic signal and an inner chamber 56 which is adapted for housing a transducer unit 58 , typically a silicon die microphone or a ball grid array package (BGA). The top, bottom, and side portions 48 , 50 , 52 are electrically connected, for example with a conductive adhesive 60 . The conductive adhesive may be provided conveniently in the form of suitably configured sheets of dry adhesive disposed between the top, bottom and side portions 48 , 50 and 52 . The sheet of dry adhesive may be activated by pressure, heat or other suitable means after the portions are brought together during assembly. Each portion may comprise alternating conductive and non-conductive layers of 44 , 46 .
The chamber 56 may include an inner lining 61 . The inner lining 61 is primarily formed by conductive material. It should be understood that the inner lining may include portions of non-conductive material, as the conductive material may not fully cover the non-conductive material. The inner lining 61 protects the transducer 58 against electromagnetic interference and the like, much like a faraday cage. The inner lining 61 may also be provided by suitable electrically coupling together of the various conductive layers within the top, bottom and side portions 48 , 50 and 52 of the housing.
In the various embodiments illustrated in FIGS. 7-10 and 23 - 26 , the portions of the housing 42 that include the aperture or acoustic port 54 further include a layer of material that forms an environmental barrier 62 over or within the aperture 54 . This environmental barrier 62 is typically a polymeric material formed to a film, such as a polytetrafluoroethylene (PTFE) or a sintered metal. The environmental barrier 62 is supplied for protecting the chamber 56 of the housing 42 , and, consequently, the transducer unit 58 within the housing 42 , from environmental elements such as sunlight, moisture, oil, dirt, and/or dust. The environmental barrier 62 will also have inherent acoustic properties, e.g. acoustic damping/resistance. Therefore the environmental barrier 62 is chosen such that its acoustic properties cooperate with the transducer unit 58 to enhance the performance of the microphone. This is particularly true in connection with the embodiments illustrated in FIGS. 24 and 25 , which may be configured to operate as directional microphones.
The environmental barrier layer 62 is generally sealed between layers of the portion, top 48 or bottom 50 in which the acoustic port 54 is formed. For example, the environmental barrier may be secured between layers of conductive material 44 thereby permitting the layers of conductive material 44 to act as a capacitor (with electrodes defined by the metal) that can be used to filter input and output signals or the input power. The environmental barrier layer 62 may further serve as a dielectric protective layer when in contact with the conductive layers 44 in the event that the conductive layers also contain thin film passive devices such as resistors and capacitors.
In addition to protecting the chamber 56 from environmental elements, the barrier layer 62 allows subsequent wet processing, board washing of the external portions of the housing 42 , and electrical connection to ground from the walls via thru hole plating. The environmental barrier layer 62 also allows the order of manufacturing steps in the fabrication of the printed circuit board-based package to be modified. This advantage can be used to accommodate different termination styles. For example, a double sided package can be fabricated having a pair of apertures 54 (see FIG. 25 ), both including an environmental barrier layer 62 . The package would look and act the same whether it is mounted face up or face down, or the package could be mounted to provide directional microphone characteristics. Moreover, the environmental barrier layer 62 may also be selected so that its acoustic properties enhance the directional performance of the microphone.
Referring to FIGS. 7 , 8 , and 11 - 13 the transducer unit 58 is generally not mounted to the top portion 48 of the housing. This definition is independent of the final mounting orientation to an end user's circuit board. It is possible for the top portion 48 to be mounted face down depending on the orientation of the transducer 58 as well as the choice for the bottom portion 50 . The conductive layers 44 of the top portion 48 may be patterned to form circuitry, ground planes, solder pads, ground pads, capacitors and plated through hole pads. Referring to FIGS. 1-13 there may be additional alternating conductive layers 44 , non-conductive layers 46 , and environmental protective membranes 62 as the package requires. Alternatively, some layers may be deliberately excluded as well. The first non-conductive layer 46 may be patterned so as to selectively expose certain features on the first conductive layer 44 .
FIG. 11 illustrates an alternative top portion 48 for a microphone package. In this embodiment, a connection between the layers can be formed to provide a conduit to ground. The top portion of FIG. 11 includes ground planes and/or pattern circuitry 64 and the environmental barrier 62 . The ground planes and or pattern circuitry 64 are connected by pins 65 .
FIG. 12 illustrates another embodiment of a top portion 48 . In addition to the connection between layers, ground planes/pattern circuitry 64 , and the environmental barrier 62 , this embodiment includes conductive bumps 66 (e.g. Pb/Sn or Ni/Au) patterned on the bottom side to allow secondary electrical contact to the transducer 58 . Here, conductive circuitry would be patterned such that electrical connection between the bumps 66 and a plated through hole termination is made.
FIG. 13 illustrates yet another embodiment of the top portion 48 . In this embodiment, the top portion 48 does not include an aperture or acoustic port 54 .
Referring to FIGS. 7 , 8 and 14 - 18 , the bottom portion 50 is the component of the package to which the transducer 58 is primarily mounted. This definition is independent of the final mounting orientation to the end user's circuit board. It is possible for the bottom portion 50 to be mounted facing upwardly depending on the mounting orientation of the transducer 58 as well as the choice for the top portion 48 construction Like the top portion 48 , the conductive layers 44 of the bottom portion 50 may be patterned to form circuitry, ground planes, solder pads, ground pads, capacitors and plated through hole pads. As shown in FIGS. 14-18 , there may be additional alternating conductive layers 44 , non-conductive layers 46 , and environmental protective membranes 62 as the package requires. Alternatively, some layers may be deliberately excluded as well. The first non-conductive layer 46 may be patterned so as to selectively expose certain features on the first conductive layer 44 .
Referring to FIGS. 14 a through 14 d , the bottom portion 50 comprises a laminated, multi-layered board including layers of conductive material 44 deposited on layers of non-conductive material 46 . Referring to FIG. 14 b , the first layer of conductive material is used to attach wire bonds or flip chip bonds. This layer includes etched portions to define lead pads, bond pads, and ground pads. The pads would have holes drilled through them to allow the formation of plated through-holes.
As shown in FIG. 14 c , a dry film 68 of non-conductive material covers the conductive material. This illustration shows the exposed bonding pads as well as an exposed ground pad. The exposed ground pad would come in electrical contact with the conductive epoxy and form the connection to ground of the side portion 52 and the base portion 50 .
Referring to FIG. 14 d , ground layers can be embedded within the base portion 50 . The hatched area represents a typical ground plane 64 . The ground planes do not overlap the power or output pads, but will overlap the transducer 58 .
Referring to FIG. 15 , an embodiment of the bottom portion 50 is illustrated. The bottom portion 50 of this embodiment includes a solder mask layer 68 and alternating layers of conductive and non-conductive material 44 , 46 . The bottom portion further comprises solder pads 70 for electrical connection to an end user's board.
FIGS. 16 and 17 illustrate embodiments of the bottom portion 50 with enlarged back volumes 18 . These embodiments illustrate formation of the back volume 18 using the conductive/non-conductive layering.
FIG. 18 shows yet another embodiment of the bottom portion 50 . In this embodiment, the back portion 50 includes the acoustic port 54 and the environmental barrier 62 .
Referring to FIGS. 7-10 and 19 - 22 , the side portion 52 is the component of the package that joins the bottom portion 50 and the top portion 48 . The side portion 52 may include a single layer of a non-conductive material 46 sandwiched between two layers of conductive material 44 . The side portion 52 forms the internal height of the chamber 56 that houses the transducer 58 . The side portion 52 is generally formed by one or more layers of circuit board material, each having a routed window 72 (see FIG. 19 ).
Referring to FIGS. 19-22 , the side portion 52 includes inner sidewalls 74 . The inner sidewalls 74 are generally plated with a conductive material, typically copper, as shown in FIGS. 20 and 21 . The sidewalls 74 are formed by the outer perimeter of the routed window 72 and coated/metallized with a conductive material.
Alternatively, the sidewalls 74 may be formed by may alternating layers of non-conductive material 46 and conductive material 44 , each having a routed window 72 (see FIG. 19 ). In this case, the outer perimeter of the window 72 may not require coverage with a conductive material because the layers of conductive material 44 would provide effective shielding.
FIGS. 23-26 illustrate various embodiments of the microphone package 40 . These embodiments utilize top, bottom, and side portions 48 , 50 , and 52 which are described above. It is contemplated that each of the top, bottom, and side portion 48 , 50 , 52 embodiments described above can be utilized in any combination without departing from the invention disclosed and described herein.
In FIG. 23 , connection to an end user's board is made through the bottom portion 50 . The package mounting orientation is bottom portion 50 down. Connection from the transducer 58 to the plated through holes is be made by wire bonding. The transducer back volume 18 is formed by the back hole (mounted down) of the silicon microphone only. Bond pads, wire bonds and traces to the terminals are not shown. A person of ordinary skilled in the art of PCB design will understand that the traces reside on the first conductor layer 44 . The wire bonds from the transducer 58 are be connected to exposed pads. The pads are connected to the solder pads via plated through holes and traces on the surface.
In FIG. 24 , connection to the end user's board is also made through the bottom portion 50 . Again, the package mounting orientation is bottom portion 50 . Connection from the transducer 58 to the plated through holes are made by wire bonding. The back volume is formed by a combination of the back hole of the transducer 58 (mounted down) and the bottom portion 50 .
In FIG. 25 , connection to the end user's board is also made through the bottom portion 50 . Again, the package mounting orientation is bottom portion 50 . Connection from the transducer 58 to the plated through holes are made by wire bonding. With acoustic ports 54 on both sides of the package, there is no back volume. This method is suitable to a directional microphone.
In FIG. 26 , connection to the end user's board is made through the top portion 48 or the bottom portion 53 . The package mounting orientation is either top portion 48 down or bottom portion 50 down. Connection from the transducer 58 to the plated through holes is made by flip chipping or wire bonding and trace routing. The back volume 18 is formed by using the air cavity created by laminating the bottom portion 50 and the top portion 48 together. Some portion of the package fabrication is performed after the transducer 58 has been attached. In particular, the through hole formation, plating, and solder pad definition would be done after the transducer 58 is attached. The protective membrane 62 is hydrophobic and prevents corrosive plating chemistry from entering the chamber 56 .
Referring to FIGS. 27-29 , the portion to which the transducer unit 58 is mounted may include a retaining ring 84 . The retaining ring 84 prevents wicking of an epoxy 86 into the transducer 58 and from flowing into the acoustic port or aperture 54 . Accordingly, the shape of the retaining ring 84 will typically match the shape of the transducer 58 foot print. The retaining ring 84 comprises a conductive material (e.g., 3 mil. thick copper) imaged on a non-conductive layer material.
Referring to FIG. 27 , the retaining ring 84 is imaged onto a nonconductive layer. An epoxy is applied outside the perimeter of the retaining ring 84 , and the transducer 58 is added so that it overlaps the epoxy 86 and the retaining ring 84 . This reduces epoxy 86 wicking up the sides of the transducer's 58 etched port (in the case of a silicon die microphone).
Alternatively, referring to FIG. 28 , the retaining ring 84 can be located so that the transducer 58 does not contact the retaining ring 84 . In this embodiment, the retaining ring 84 is slightly smaller than the foot print of the transducer 58 so that the epoxy 86 has a restricted path and is, thus, less likely to wick. In FIG. 29 , the retaining ring 84 is fabricated so that it contacts the etched port of the transducer 58 . The following tables provide an illustrative example of a typical circuit board processing technique for fabrication of the housing of this embodiment.
TABLE 1
Materials
Material
Type
Component
Note
1
0.5/0.5 oz. DST
Bottom Portion (Conductive
Cu 5 core FR-4
Layers Non-
Conductive Layer 1)
2
0.5/0.5 oz. DST
Bottom Portion (Conductive
Cu 5 core FR-4
Layers 3 and 4; Non-
Conductive Layer 2)
3
106 pre-preg
For Laminating
Material 1 and
Material 2
4
0.5/0.5 oz. DST
Side Portion
Metallized
Cu 40 Core FR-4
Afterward
5
Bare/0.5 oz. Cu 2
Top Portion (Each Piece
core FR-4 (2
Includes 1 Conductive and 1
pieces)
Non-Conductive Layer)
6
Expanded PTFE
Environmental Barrier
TABLE 2
Processing of Materials (Base Portion Material 1)
Step
Type
Description
Note
1
Dry Film
Conductive Layers
2
Expose
Mask Material 1 (Upper
Forms Ground
Conductive Layer)
Plane on Lower
Conductive Layer
3
Develop
4
Etch Cu
No Etching on
Upper Conductive
Layer
5
Strip Dry Film
TABLE 3
Processing of Materials (Bottom Portion Material 2)
Step
Type
Description
Note
1
Dry Film
Conductive
Layers
2
Expose
Mask Material 2 (Upper
Forms Ground
Conductive Layer)
Plane on Upper
Conductive Layer
3
Develop
4
Etch Cu
No Etching on Upper
Conductive
Layer
5
Strip Dry Film
TABLE 4
Processing of Materials 1, 2, and 3 (Form Bottom Portion)
Step
Type
Description
Note
1
Laminate
Materials 1 and 2
Laminated Using
Material 3
2
Drill Thru Holes
Drill Bit = 0.025 in.
3
Direct
Plates Thru Holes
Metallization/Flash
Copper
4
Dry Film (L1 and
L4)
5
Expose
Mask Laminated
Forms Traces and Solder
Materials 1 and 2
Pads
(Upper and Lower
Conductive Layers)
6
Develop
7
Electrolytic Cu
1.0 mil
8
Electrolytic Sn
As Required
9
Strip Dry Film
10
Etch Cu
11
Etch Cu
12
Insert Finishing
NG Option (See
NG Option for Proof
Option Here
Table Below)
of Principle
13
Dry Film (cover
2.5 mil
Minimum Thickness
lay) on Upper
on Upper Conductive
Conductive Layer
Layer
Only
14
Expose
Mask Laminated
This mask defines an
Materials 1 and 2
area on the upper
(upper and lower)
conductive layer that
will receive a dry film
solder mask (cover
lay). The bottom layer
will not have dry film
applied to it. The
plated through holes
will be bridged over by
the coating on the top.
15
Develop
16
Cure
Full Cure
17
Route Panels
Route Bit = As
Forms 4″ × 4″ pieces.
Required
Conforms to finished
dims
Table 5 describes the formation of the side portion 52 . This process involves routing a matrix of openings in FR-4 board. However, punching is thought to be the cost effective method for manufacturing. The punching may done by punching through the entire core, or, alternatively, punching several layers of no-flow pre-preg and thin core c-stage which are then laminated to form the wall of proper thickness.
After routing the matrix, the board will have to be electroless or DM plated. Finally, the boards will have to be routed to match the bottom portion. This step can be done first or last. It may make the piece more workable to perform the final routing as a first step.
TABLE 5
Processing of Material 4 (Side Portion)
Step
Type
Description
Note
1
Route/Punch
Route Bit = 0.031 in.
Forms Side Portion
Matrix of
Openings
2
Direct
0.25 mil minimum
Forms Sidewalls
Metallization/
on Side Portion
Flash Cu
3
Route Panels
Table 6 describes the processing of the top portion. The formation of the top portion 48 involves imaging a dry film cover lay or liquid solder mask on the bottom (i.e. conductive layer forming the inner layer. The exposed layer of the top portion 48 will not have a copper coating. It can be processed this way through etching or purchased this way as a one sided laminate.
A matrix of holes is drilled into the lid board. Drilling may occur after the imaging step. If so, then a suitable solder mask must be chosen that can survive the drilling process.
TABLE 6
Processing of Top Portion
Step
Type
Description
Note
1
Dry Film
Conductive Layer
2
Expose
Mask Bare Layer
Form Conduction Ring
3
Develop
4
Cure
5
Drill Matrix
Drill Bit 0.025 in.
Acoustic Ports
of Holes
6
Laminate
PTFE (Environmental
Forms Top Portion
Barrier) Between 2 Pieces
of Material 5
TABLE 7
Processing of Laminated Materials 1 and 2 with Material 4
Step
Type
Description
Note
1
Screen
Conductive
Adhesive on
Material 4
2
Laminate
Bottom Portion with
Forms Bottom
Side Portion
Portion with Side
Portion (spacer)
3
Add Transducer
Silicon Die Microphone
Assembly
and Integrated Circuit
TABLE 8
Processing of Laminated Materials 1, 2, and 4 with Material 5
Step
Type
Description
Note
1
Screen
Conductive
Adhesive on
Top Portion
2
Laminate
Bottom Portion and Side
Forms Housing
Portion with Top Portion
3
Dice
TABLE 9
Finishing Option NG (Nickel/Gold)
Step
Type
Description
Note
1
Immersion Ni
(40-50 μ-in)
2
Immersion Au
(25-30 μ-in)
TABLE 10
Finishing Option NGT (Nickel/Gold/Tin)
Step
Type
1
Mask L2 (using thick dry film or high tack dicing tape)
2
Immersion Ni (40-50 μ-in)
3
Immersion Au (25-30 μ-in)
4
Remove Mask on L2
5
Mask L1 (using thick dry film or high tack dicing tape)
bridge over cavity created by wall
6
Immersion Sn (100-250 μ-in)
7
Remove Mask on L1
TABLE 11
Finishing Option ST (Silver/Tin)
Step
Type
1
Mask L2 (using thick dry film or high tack dicing tape)
2
Immersion Ag (40-50 μ-in)
3
Remove Mask on L2
4
Mask L1 (using thick dry film or high tack dicing tape)
bridge over cavity created by wall
5
Immersion Sn (100-250 μ-in)
6
Remove Mask on L1
FIG. 30 is a plan view illustrating a panel 90 for forming a plurality of microphone packages 92 . The microphone packages 92 are distributed on the panel 90 in a 14×24 array, or 336 microphone packages total. Fewer or more microphone packages may be disposed on the panel 90 , or on smaller or larger panels. As described herein in connection with the various embodiments of the invention, the microphone packages include a number of layers, such as top, bottom and side portions of the housing, environmental barriers, adhesive layers for joining the portions, and the like. To assure alignment of the portions as they are brought together, each portion may be formed to include a plurality of alignment apertures 94 . To simultaneously manufacture several hundred or even several thousand microphones, a bottom layer, such as described herein, is provided. A transducer, amplifier and components are secured at appropriate locations on the bottom layer corresponding to each of the microphones to be manufactured. An adhesive layer, such as a sheet of dry adhesive is positioned over the bottom layer, and a sidewall portion layer is positioned over the adhesive layer. An additional dry adhesive layer is positioned, followed by an environmental barrier layer, another dry adhesive layer and the top layer. The dry adhesive layers are activated, such as by the application of heat and/or pressure. The panel is then separated into individual microphone assemblies using known panel cutting and separating techniques.
The microphone, microphone package and method of assembly herein described further allow the manufacture of multiple microphone assembly, such as microphone pairs. In the simplest form, during separation two microphones may be left joined together, such as the microphone pair 96 shown in FIG. 31 . Each microphone 98 and 100 of the microphone pair 96 is thus a separate, individually operable microphone in a single package sharing a common sidewall 102 . Alternatively, as described herein, conductive traces may be formed in the various layers of either the top or bottom portion thus allowing multiple microphones to be electrically coupled.
While specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying Claims.
|
Methods for manufacturing multiple bottom port, surface mount microphones, each containing a micro-electro-mechanical system (MEMS) microphone die, are disclosed. Each surface mount microphone features a substrate with metal pads for surface mounting the package to a device's printed circuit board and for making electrical connections between the microphone package and the device's circuit board. The surface mount microphones are manufactured from panels of substrates, sidewall spacers, and lids. Each MEMS microphone die is substrate-mounted and acoustically coupled to the acoustic port disposed in the substrate. The panels are joined together, and each individual substrate, sidewall spacer, and lid cooperate to form an acoustic chamber for its respective MEMS microphone die. The joined panels are then singulated to form individual MEMS microphones.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of U.S. Provisional Application No. 61/060,783, filed Jun. 11, 2008, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] Complex interactions between host genetic factors and environmental elements are essential contributors to and/or influence the development of most, if not all autoimmune diseases. A genetic contribution to many of these diseases was identified a number of years ago with the observation that many individuals with different “autoimmune disorders” shared specific alleles of HLA class II genes. Advancements in identifying polymorphic genes across the human genome reveal additional genetic loci associated with specific autoimmune diseases, yet the strongest genetic component remains to be the HLA class II alleles. Still, there are several puzzling observations regarding the HLA class II allele association: a) while many of the diseases are organ- or tissue-specific, they share the same predisposing HLA class II alleles, b) although these alleles are common in Caucasian populations, only a minority of individuals develop disease and c) not all individuals with a specific disease have the allele most often associated with that disease. Extensive studies have attempted to define environmental factors and/or self antigens involved in the immune response that causes or influence destruction of specific tissues. There has been a long felt need for such definitions. In a number of diseases, antigens targeted by the adaptive immune response have been identified, and in some instances, the specific peptide sequence presented by the HLA class II alleles has been identified. However, there is little information regarding the function of genetic factors and etiologic agents in the activation of innate immune responses that trigger the cascade of events that are manifest in adaptive immunity.
[0003] In contrast to many autoimmune diseases, Celiac disease (CD) is unique at least because a) the majority (90%) of patients with this disease have the HLA class II DQ2 allele, the others HLA-DQ8 and b) there is a well established etiologic agent, glutens from wheat and related prolamins in barley and rye. Like other autoimmune diseases, it is not understood why the majority of individuals with the disease-associated alleles (HLA-DQ2, 35%) exposed to glutens in these dietary grains never develop CD. The disease process is generally considered to be mediated by T cells, and indeed T cell clones recognizing specific gluten-derived peptides (gliadins) presented by HLA-DQ2 and -DQ8 have been isolated from the gut of CD patients, demonstrating the adaptive immune response to the ingested proteins. Still, the potential role of these specific alleles and gliadins in the preceding innate immune response has not been addressed.
BACKGROUND OF THE INVENTION
Incidence and Pathology of Celiac Disease
[0004] Celiac disease (CD) is an autoimmune disorder triggered and influenced by glutens in the dietary grains wheat, barley and rye in genetically susceptible individuals (Sollid, Ann. Rev. Immunol., 18:53-81 (2000); Green et al., Lancet, 362(9381):383-391 (2003); and Sollid et al., Acta. Odontol. Scand., 59(3):183-186 (2001)). CD is a chronic inflammatory disorder of the small intestine triggered and influenced by dietary glutens in genetically susceptible individuals 1 . It has an astounding prevalence in North American and European countries, affecting ˜1% of the general population and 8-15% of first-degree relatives and patients suffering from other autoimmune diseases such as type 1 diabetes (T1D), autoimmune thyroiditis, rheumatoid arthritis (RA), Sjogren's syndrome, Addison's disease and autoimmune hepatitis (Fasano et al., Arch. Intern. Med., 163(3):286-292 (2003); Betterle et al., Eur. J. Endocrinol., 154(2):275-279 (2006); Carroccio et al., Digestion, 60(1):86-88 (1999); and Pratesi et al., Scand. J. Gastroenterol., 38(7):747-750 (2003)). Given the increasing number of inflammatory disorders associated with gluten intolerance, CD provides a unique model for investigating the immunological events involved in its pathogenesis because it is the only disease for which the external (glutens) and genetic factors (specific HLA alleles) of disease susceptibility are clearly known.
[0005] CD is characterized by chronic inflammation of the small intestine resulting in atrophy of absorptive villi, hyperplasia of crypts, massive infiltration of intraepithelial lymphocytes and increased recruitment of lamina propria mononuclear cells, which often causes malabsorption and a plethora of clinical manifestations depending on the age of onset, extent of disease, and existence of additional tissue pathology. Classical symptoms include but are not limited to diarrhea, abdominal cramping, bloating and fatigue. CD is diagnosed upon detection of serum IgA antibodies to the autoantigen human tissue transglutaminase II (tTG), and confirmed by intestinal biopsy. The only treatment is lifelong adherence to a strict gluten-free diet, which presents a major challenge for individuals living with this disease as many struggle to follow total dietary compliance. Left untreated, severe problems such as vitamin deficiencies, osteoporosis and other extraintestinal complications may occur. Most affected individuals respond to the gluten-free diet with complete remission of tissue pathology, however some progress to refractory disease, increasing their risk of gastrointestinal malignancies (Brousse et al., Best Pract. Res. Clin. Gastroenterol., 19(3):401-412 (2005)).
[0006] Celiac disease results from convoluted interactions between multiple predisposing genes, dietary glutens, and innate and adaptive arms of the immune system, which may influence one another. Each of these factors pertinent to the pathogenesis of CD and related autoimmune diseases will be described briefly below.
[0007] In one aspect, the present invention provides a pepsin-trypsin digest of gliadin (PTG) which induces production of IL-23 by a subset of monocytes with highest levels in CD patients on a gluten-free diet, intermediate levels from HLA-DQ matched monocytes from normal individuals, and lowest levels from monocytes from HLA-DQ mismatched normal individuals, and the relative levels of other cytokines involved in the T H 17 response network follow this same pattern. In one aspect, IL-1β production is also induced by PTG and temporarily precedes IL-23 production, and this cytokine alone induces IL-23 production while the IL-1 receptor antagonist inhibits IL-23 production generated by monocytes exposed to PTG. This provides an non-limiting example of cytokine, pathway, genetic influence. In another aspect of the invention, the cytokine responses can only be generated with PTG and not with overlapping synthetic peptides from α-gliadin, but are also recapitulated with β-glucans from barley.
[0008] In one aspect of the invention, the IL-23/T H 17 innate immune response axis is activated by exposing defined populations of antigen presenting cells (APC) to gliadin proteins, and that this innate immune response influences the pathogenesis of CD in genetically predisposed individuals.
[0009] The present invention in an additional aspect establishes that the subset of monocytes and/or immature DC that produce IL-23 and related T H 17 cytokines in response to PTG exposure.
[0010] In one aspect, the present invention identifies, enumerates and compares the relative distribution of population(s) of monocytes, T cells, and their respective subsets associated with the IL 23/T H 17 pathway in peripheral blood mononuclear cells (PBMC) from patients with active and treated CD and HLA-DQ matched and HLA-DQ mismatched healthy individuals.
[0011] In one aspect, the present invention determines if the array and magnitude of cytokine and chemokine responses to PTG and other agents that activate the IL-23/T H 17 innate immune response is different in PBMC obtained from patients with active and treated CD and HLA-DQ matched and HLA-DQ mismatched healthy individuals.
Genetics of Celiac Disease and Related Autoimmune Disorders
[0012] A remarkably strong association exists between susceptibility to CD and the specific HLA class II alleles HLA-DQ2 and HLA-DQ8, with 95% of patients expressing HLA-DQ2 (Sollid, Annu. Rev. Immunol., 18:53-81 (2000); and Margaritte-Jeannin et al., Tissue Antigens, 63(6):562-567 (2004). Moreover, individuals homozygous for the DQB*02 genes (DQ2/DQ2 and DQ2/DR7) are at increased risk for disease than those expressing the DQ8 (DR4)/X genotype (Louka et al., Hum. Immunol., 64(3):350-358 (2003); and Vader et al., Proc. Natl. Acad. Sci., U.S.A., 100(21):12390-12395 (2003)). These genes, located within the major histocompatibility complex on chromosome 6p21, encode cell-surface antigen-presenting proteins vital to the T cell-mediated process of adaptive immunity. Detection of gliadin-specific HLA-DQ2 and -DQ8-restricted CD4 + T cells clones in the active celiac lesion has helped explain the genetic prerequisite and inspired a decade of research establishing a central role for the adaptive immune response in CD (Sollid, Annu. Rev. Immunol., 18:53-81 (2000); Lundin et al., J. Exp. Med., 178(1):187-196 (1993); Lundin et al., Hum. Immunol., 41(4):285-291 (1994); and Molberg et al., Scand. J. Immunol., 46(3):103-109 (1997)). While these alleles are required for CD, they are not sufficient for pathogenesis given that the majority of individuals expressing HLA-DQ2/8 encounter gluten everyday and never develop disease.
[0013] Inheritance of the HLA-DQ alleles contributes 40% of the genetic requirement in CD, and the remaining 60% results from a complex mosaic of undetermined non-HLA genes (Sollid et al., Clin. Gastroenterol. Hepatol., 3(9):843-851 (2005)). Genetic association studies have identified numerous genes as candidates for susceptibility to CD, but confounding factors such as genetic heterogeneity, linkage disequilibrium, population stratification and limited sample size have generated conflicting results (Latiano et al., J. Pediatr. Gastroenterol. Nutr., 45(2):180-186 (2007); and Capilla et al., Tissue Antigens, 70(4):324-329 (2007)). These include the TNF-308A variant within the HLA complex on chromosome 6p21 (Sumnik et al., Diabetes Care, 29(4):858-863 (2006)), the CD28/CTLA4/ICOS cluster (CELIAC3) on chromosome 2q33 (Amundsen et al., Tissue Antigens, 64(5):593-599 (2004)), FcgRIIa*519GG on chromosome 1q23 (Alizadeh et al., Hum. Mol. Genet., 16(21):2552-2559 (2007)), as well as chromosomal loci 5q32-34 (CELIAC2) that encode IL17B and other cytokines (Ryan et al., Tissue Antigens, 65(2):150-155 (2005)) 3p21 that encodes the autoantigen GM1 ganglioside and the fractalkine receptor CX3CR1 (Neuhausen et al., Am. J. Med. Genet., 111(1):1-9 (2002)), 19p13 (CELIAC4) (Curley et al., Eur. J. Hum. Genet., 14(11):1215-1222 (2006); and Van Belzen et al., Gastroenterology, 125(4):1032-1041 (2003)), 11p11, 18q23, 7q31, 16q23, and 10q26 (King et al., Ann. Hum. Genet., 65(Pt. 4):377-386 (2001); and King et al., Ann. Hum. Genet., 64(Pt. 6):479-490 (2000)). Interestingly, the HLA class II alleles and several of the above mentioned loci have been implicated in other autoimmune diseases including T1D, autoimmune thyroiditis, Crohn's disease, RA, psoriasis and multiple sclerosis (MS), indicating a common disease process in the generation of adaptive immune responses that characterize these seemingly unrelated conditions. Additional genes include TNFR1, located on chromosome 12p13, a locus recently identified with CD in Bedouin kindred (Eller et al., Hum. Immunol., 67(11):940-950 (2006)); TNFR2, IL23R and NOD2 residing on chromosomes 1p36, 1p31 and 16q12 respectively, which have been implicated in Crohn's disease (Waschke et al., Am. J. Gastroenterol., 100(5):1126-1133 (2005); Pierik et al., Aliment Pharmacol. Ther., 20(3):303-310 (2004); Weersma et al., “ATG16L1 and IL23R Are Associated With Inflammatory Bowel Diseases but Not With Celiac Disease in The Netherlands”, Am. J. Gastroenterol. ( 2007); and Eckmann et al., Immunity, 22(6):661-667 (2005)); genes encoding the chemokine receptor CCR6 on chromosome 6q27, a locus associated with T1D, RA and MS, and its only known ligand CCL20 on chromosome 2q35-2q36 that has been linked to inflammatory bowel disease (IBD) (Nelson et al., Genomics, 73(1):28-37 (2001); and Rodriguez-Bores et al., World J. Gastroenterol., 13(42):5560-5570 (2007)); the IL-1 gene cluster on 2q previously reported in CD (Sumnik et al., Diabetes Care, 29(4):858-863 (2006); Moreno et al., Immunogenetics, 57(8):618-620 (2005); and Chowers et al., Clin. Exp. Immunol., 107(1):141-147 (1997)). A number of these genes encode products that are known to participate in inflammatory processes that are related to innate immune responses. Heretofore, the obligatory role of specific cytokines, chemokines and their cognate receptors in the IL23-mediated T H 17 pathway were not clearly functionally correlated with disease associated genes.
Etiologic Agents of Celiac Disease
[0014] The external trigger for CD is enteric exposure to specific proteins in dietary grains known as prolamins, specifically wheat gliadins, barley hordeins, and rye secalins, which influence CD. This is illustrated by both the clinical and mucosal recovery of CD patients following a gluten-free diet (Fasano et al., Gastroenterology, 120(3):636-651 (2001)). Several features of these prolamins contribute to their immunogenicity. Their high proline content (>15%) confers resistance to proteolytic degradation in the gastrointestinal tract, and their abundant glutamine (>30%) residues provide copious targets for deamidation by the autoantigen tTG, which enhances the binding affinity to HLA-DQ2 at positions P4, P6 or P7 and P1, P4 or P9 for HLA-DQ8 (Tollefsen et al., J. Clin. Invest., 116(8):2226-2236 (2006); Johansen et al., Clin. Immunol. Immunopathol., 79(3):288-293 (1996); Vartdal et al., Eur. J. Immunol., 26(11):2764-2772 (1996); Johansen et al., Int. Immunol., 8(2):177-182 (1996); Godkin et al., Int. Immunol., 9(6):905-911 (1997); Kwok et al., J. Exp. Med., 183(3):1253-1258 (1996); and Kwok et al., J. Immunol., 156(6):2171-2177 (1996). In addition, these peptides naturally assume the left-handed polyproline II helical conformation preferred by all bound HLA-DQ2 and DQ8 ligands (Molberg et al., Eur. J. Immunol., 31(5):1317-1323 (2001); Shan et al., Science, 297(5590):2275-2279 (2002); and Kim et al., Proc. Natl. Acad. Sci., U.S.A., 101(12):4175-4179 (2004)). While these characteristics are important in generating the adaptive immune response that is manifest as CD, the structural or biochemical properties that lead to intestinal permeability and a role for innate cell activation in this process remain unclear.
[0015] The heterogeneous nature of wheat gliadin, which contains over 50 different proteins categorized as ω5-, ω1,2-α/β- or γ-gliadins based on amino acid sequence, composition and molecular weight (Wieser, Food Microbiol., 24(2):115-119 (2007)), has hindered both the identification of T cell epitopes that are targets of the adaptive immune response and properties required for innate cell activation (Turner et al., Protein Pept. Lett., 9(1):23-29 (2002)). Although lectin-like carbohydrate epitopes have not been detected in gliadin, higher molecular weight fractions (i.e., ω-gliadins) were recently shown to contain carbohydrates with the capacity to bind GM1 ganglioside, another autoantigen reported in CD (Alaedini et al., J. Neuroimmunol., 177(1-2):167-172 (2006)). GM1 is the ubiquitously expressed receptor for cholera toxin B (CTB) recognized for its potent immunomodulatory properties that are profoundly influenced by HLA class II haplotype in mouse models Nashar et al., Immunology, 106(1):60-70 (2002); Hirst et al., Symp. Ser. Soc. Appl. Microbiol., 27:26S-34S (1998); and Nashar et al., Vaccine, 13(9):803-810 (1995)). Indeed, Drago and colleagues have described a pronounced increase in the magnitude and duration of zonulin-mediated intestinal permeability in response to gliadin exposure in individuals with CD compared to that of healthy subjects of undetermined HLA status (Drago et al., Scand. J. Gastroenterol., 41(4):408-419 (2006)). Therefore, CD may ultimately result from an augmented innate immune response occurring in HLA-DQ2/DQ8 positive individuals upon ligation of glycosylated gliadins with GM1 on intestinal epithelial cells or intestinal dendritic cells (DC), similar to that generated by CTB/GM1 in H-2 b mice.
[0016] Clearly, environmental factors involved in development of CD are multifaceted and remain unclear. Several aspects of gluten exposure may influence the risk of CD occurrence, such as the amount of ingested gluten, the quality of ingested gluten, and the time at which gluten is included in infant feeding (Sollid, Nat. Rev. Immunol., 2(9):647-655 (2002)).
Immunobiology of Celiac Disease and Related Autoimmune Diseases
[0017] Innate and Adaptive Immunity in CD
[0018] While the major genetic and environmental requirements for CD are known, the immunological events responsible for the deranged immune response are not well understood. Hallmarks of active disease include infiltration of cytotoxic intraepithelial lymphocytes (IEL) in the epithelium and gliadin-specific IFNγ-secreting CD4 + T cell clones restricted by HLA-DQ2 and DQ8 in the lamina propria (Lundin et al., J. Exp. Med., 178(1):187-196 (1993); Molberg et al., Scand. J. Immunol., 46(3):103-109 (1997); Halstensen et al., Scand. J. Immunol., 30(6):665-672 (1989); Maiuri et al., Am. J. Gastroenterol., 96(1):150-156 (2001); Meresse et al., Immunity, 21(3):357-366 (2004); and Meresse et al., J. Exp. Med., 203(5):1343-1355 (2006)). IEL differ from their lamina propria counterparts in both phenotype and function, and are considered more innate because they do not require TCR-specificity for activation. In healthy individuals, the majority of IEL are αβ T cells, 13% are γδT cells, 10% are CD8αα T cells, and 10% appear to be immature CD7 + CD3 − T cells. This distribution is dramatically skewed in CD patients irrespective of diet with a permanent increase of γδ T cells and diminished proportion of CD7 + CD3 − T cells (Eiras et al., Cytometry, 34(2):95-102 (1998); and Camarero et al., Acta Paediatr., 89(3):285-290 (2000)). Subsets of IEL are thought to be directly involved in the immediate destruction of IEC following consumption of dietary gluten in individuals with CD. The nonimmunodominant p31-43 epitope of α-gliadin has been demonstrated to activate both IL-15 dependent NKG2D-mediated killing of MICA/B + IEC and IFNγ driven NKG2C-mediated killing of HLA-E + IEC (Maiuri et al., Am. J. Gastroenterol., 96(1):150-156 (2001); and Meresse et al., J. Exp. Med., 203(5):1343-1355 (2006)). This same toxic epitope has also been reported to activate mucosal antigen presenting cells (APC), defined as CD3 − COX2 + CD86 + cells, isolated from intestinal biopsies of CD patients, but the mechanisms or cell population(s) involved were not determined (Maiuri et al., Am. J. Gastroenterol., 96(1):150-156 (2001)). While the adaptive immune response to gluten (and specifically immunodominant epitopes of the derivative protein, gliadin) has been well characterized in CD, the early events responsible for activation of the innate immune response have not been established.
[0019] Gliadin is thought to access the intestinal submucosa through the induction of zonulin signaling, which reversibly disrupts the integrity of epithelial tight junctions (Drago et al., Scand. J. Gastroenterol., 41(4):408-419 (2006)). Once the intestinal barrier is compromised, gliadin protein(s) or the peptides produced by enzymatic degradation of the protein must be acquired and processed by antigen presenting cells for presentation to gliadin-specific CD4 + T cells to initiate the adaptive immune response that characterizes CD (Weenink et al., Immunol. Cell Biol., 75(1):69-81 (1997)). The dynamic communication between IEC and intestinal dendritic cells (DC) are thought to regulate the processes of oral tolerance to harmless food antigens and commensal bacteria and immunity to harmful pathogens ( FIG. 1 ). The aberrant response to gluten in CD immediately calls into question the maturation and activation state of mucosal DC subsets in these individuals. New evidence implicates a subset of lamina propria DQ2 + DC in the immunopathogenesis of CD. These DC were significantly increased in the lamina propria of untreated CD patients compared to treated CD patients and healthy donors, displayed an activated mature phenotype, and were exceptional at stimulating gliadin-specific T cell clones in vitro. Surface phenotyping suggest they derive from peripheral blood monocytes that continuously migrate through the intestinal mucosa (Raki et al., Gastroenterology, 131(2):428-438 (2006)). Indeed, Gliadin has also been reported to induce augmented levels of TNFα and IL-8 in blood monocytes from untreated CD patients compared to treated CD patients and healthy donors (Cinova et al., J. Clin. Immunol., 27(2):201-209 (2007)), and to mature monocyte-derived DC from healthy donors (Palova-Jelinkova et al., J. Immunol., 175(10):7038-7045 (2005)). These findings suggest that intolerance to gluten in CD may be initiated by accumulation and maturation of normally quiescent circulating monocytes upon encounter with gliadin, which can easily be manipulated in vitro to elucidate the mechanisms involved.
[0020] CD16 + Monocytes and Chronic Inflammation
[0021] Monocytes and their progeny are integral components of the innate immune system. In response to environmental antigens, conserved pattern recognition receptors (PRR) trigger cytokine production directing the immune response towards cellular and humoral adaptive immunity or immunologic tolerance to the encountered antigen (Williams et al., Leuk Lymphoma, 34(1-2):1-23 (1999)). Monocytes comprise two main subsets with distinct phenotypes and functions. In healthy individuals, 90-95% are classical monocytes, determined by CD14 high CCR2 + CD16 − GM1 low CX 3 CR1 low , which serve as precursors for inflammatory DC recruited to sites of inflammation. The remaining 5-10%, characterized as CD14 low CCR2 − CD16 + GM1 high CX 3 CR1 high , are considered resident monocytes because they constantly patrol non-inflated tissues in response to fractalkine (FKN/CX3CL1), a transmembrane chemokine constitutively expressed by IEC (Ziegler-Heitbrock, J. Leukoc. Biol., 81(3):584-592 (2007.); Yano et al., Acta. Med. Okayama, 61(2):89-98 (2007); and Moreno-Altamirano et al, Immunology, 120(4):536-543 (2007)). Moreover, this subset has been demonstrated to preferentially differentiate into migratory DC that mature upon exposure to yeast zymosan, serving as a primary first line of defense to invading pathogens (Randolph et al., J. Exp. Med., 196(4):517-527 (2002)). CD14 low CD16 + monocytes are also referred to as “proinflammatory” because they exhibit a more mature phenotype, have a greater capacity to produce the proinflammatory cytokines TNFα, IL-1 and IL-6, and are expanded in a number of inflammatory conditions including RA, Crohn's disease, Grave's disease, atherosclerosis, HIV (Ulrich et al., Am. J. Transplant., 8(1):103-110 (2008); Rahman et al., Crit. Care Med., 32(12):2457-2463 (2004); Abel et al., FEMS Microbiol. Immunol., 5(5-6):317-323 (1992); Belge et al., J. Immunol., 168(7):3536-3542 (2002); Ziegler-Heitbrock, Immunol. Today, 17(9):424-428 (1996); Abrahams et al., Arthritis Rheum, 43(3):608-616 (2000); Ancuta et al., J. Leukoc. Biol., 80(5):1156-1164 (2006); and Grip et al., Inflamm. Bowel Dis., 13(5):566-572 (2007)) and following excessive exercise (Steppich et al., Am. J. Physiol. Cell Physiol., 279(3):C578-C586 (2000)). Indeed, an increase of CD14 + CD16 + DQ2 + monocytes has been noted in the intestinal lesion of untreated CD patients; however their role in the immunopathogenesis of CD was neglected and warrants further exploration (Raki et al., Gastroenterology, 131(2):428-438 (2006)). Our novel findings indicate that this minor population of monocytes plays a fundamental role in the innate immune response to gliadin, and offer insight into the mechanisms involved.
[0022] IL-23/T H 17 Paradigm in Autoimmune Disease
[0023] In recent years, the emergence of the T H 17 hypothesis has replaced the T H 1 paradigm invoked to explain cell-mediated tissue damage in autoimmunity. A compelling association between the IL-23 mediated T H 17 pathway and tissue destruction in RA, psoriasis, Crohn's disease, ulcerative colitis and MS has not been described in CD (Fuss et al., Inflamm. Bowel Dis., 12(1):9-15 (2006); Kim et al., Scand. J. Rheumatol., 36(4):259-264 (2007); Kim et al., Rheumatology ( Oxford ), 46(1):57-64 (2007); Becker et al., J. Clin. Invest., 112(5):693-706 (2003); Lee et al., J. Exp. Med., 199(1):125-130 (2004); Piskin et al., J. Immunol., 176(3):1908-1915 (2006); and Vaknin-Dembinsky et al., J. Immunol., 176(12):7768-7774 (2006)).
[0024] IL-23 is a heterodimeric cytokine secreted by activated APC that consists of the IL-12/23p40 subunit and the protein IL-23p19 (Oppmann et al., Immunity, 13(5):715-725 (2000)); and Langrish et al., Immunol. Rev., 202:96-105 (2004)). It expands the memory subset of CD4 + T cells that secrete the tissue destructive cytokine IL-17, termed T H 17 (Steinman, Nat. Med., 13(2):139-145 (2007); and McKenzie et al, Trends. Immunol., 27(1):17-23 (2006)). This subset comprise a distinct lineage of CD4 + T cells generated in the presence of activated monocytes and IL-1 and IL-23 and in the absence of the T H 1 cytokine IFNγ, providing the necessary signals for STAT3-dependent transcription of the T H 17 master regulator RORC2 (Zhou et al., Nat. Immunol., 8(9):967-974 (2007); and Evans et al., Proc. Natl. Acad. Sci., U.S.A., 104(43):17034-17039 (2007)). T H 17 cells are characterized, for example, by surface expression of IL23R, CD45RO, CCR6 and CCR4 and their ability to produce IL-17A, IL-17F, IL-6, TNFα IL-21 and IL-22 (Steinman, Nat. Med., 13(2):139-145 (2007); Singh et al., J. Immunol., 180(1):214-21 (2008); Acosta-Rodriguez et al., Nat. Immunol., 8(6):639-646 (2007); and Wilson et al., Nat. Immunol., 8(9):950-957 (2007)). These exemplary cytokines enhance T cell priming and augment the proinflammatory mediators IL-1β, IL-6, TNFα, CXCL1 (GRO-1), CXCL2 (MIP-2α), and CXCL8 (IL-8), which recruit neutrophils and perpetuate inflammation (Schmidt-Weber et al., J. Allergy Clin. Immunol., 120(2):247-254 (2007)). Neutralization of IL-17, IL-1, IL-23 or CCL20 has been shown to ameliorate tissue pathology in autoimmune models of RA, Crohn's, and MS, illustrating the critical role of these cytokines/chemokines in the T H 17 response (Bush et al., Arthritis Rheum., 46(3):802-805 (2002); Hirota et al., J. Exp. Med., 204(12):2803-2812 (2007); Lubberts et al., Arthritis Rheum., 50(2):650-659 (2004); Lee et al., Gastroenterology, 133(1):108-123 (2007); Yen et al., J. Clin. Invest., 116(5):1310-1316 (2006); and Chen et al., J. Clin. Invest., 116(5):1317-1326 (2006)). In addition to activating T H 17 cells, IL-23 is thought to contribute to the chronicity of inflammation in an autocrine fashion, stimulating production of IL-1β, IL-6 and TNFα in IL-23R + myeloid-derived APC (Hue et al., J. Exp. Med., 203(11):2473-2483 (2006); and Belladonna et al., J. Immunol., 168(11):5448-5454 (2002)).
[0025] Important for protection against microbial infection, studies have identified a number of agents capable of inducing IL-23 in monocytes and various sources of DC, depending on the cytokine milieu, the morphology of the microbe, and the differentiation state of the APC (Cooper, Eur. J. Immunol., 37(10):2680-2682 (2007)). These include cytokines, PGE 2 , FasL and receptor/ligand pairs such as Dectin1/β-glucan, NOD2/peptidoglycan, and the combination of Dectin1 and TLR2 for yeast zymosan particles (Sheibanie et al., Faseb. J, 18(11):1318-1320 (2004); Liu et al., Rheumatology ( Oxford ), 46(8):1266-1273 (2007); LeibundGut-Landmann et al., Nat. Immunol., 8(6):630-638 (2007); Nakamura et al., FEMS Immunol. Med. Microbiol., 47(1):148-154 (2006); and van Beelen et al., Immunity, 27(4):660-669 (2007)). Despite the undisputed advantages of studying CD as a model of autoimmunity, the effect of gliadins on the IL-23/T H 17 is unknown.
SUMMARY OF THE INVENTION
[0026] Autoimmune diseases are the consequence of complex interactions between a mosaic of host genetic factors and etiologic elements. Celiac disease (CD) is an autoimmune disease prevalent in 1% of the general population, but is unique on two accounts; a) the majority (90%) of individuals with CD have the HLA class II DQ2 allele, the others HLA-DQ8 and b) the etiologic agent is gluten proteins from wheat and related prolamins in barley and rye. The disease process is generally considered to be mediated by T cells that recognize HLA-DQ2 specific peptide sequences in gluten. CD14 low CD16 + monocytes in PBMC from patients and controls produce the cytokines and chemokine associated with this pathway (IL-23, IL-1β, IL-6, TNFα, MIP-3α) when exposed to pepsin-trypsin digest of gliadin (PTG). Cytokine levels are significantly higher in cells from treated CD patients than controls. While levels detected in HLA-DQ2 matched controls were reduced compared to patients, they were considerably higher than controls not having the disease associated alleles. Gliadin activation of the IL-23/T H 17 innate immune response pathway plays a fundamental role in the pathogenesis of CD. We confirmed the cell source(s) of the IL-23 response to PTG, classify, enumerate and compare the relative distribution of population(s) of monocytes, T cells, and their respective subsets associated with the IL-23/T H 17 pathway in PBMC from CD patients with active disease, treated disease, and HLA-DQ2 matched and HLA-DQ mismatched healthy individuals and establish the array and magnitude of cytokine/chemokine responses to PTG from the different patient groups. We identify phenotypic and functional properties of cell populations that respond to gliadins with induction of cytokines/chemokines comprising the IL-23/T H 17 innate immune response, and establish differences that distinguish patients with CD from healthy populations. We identify therapeutic targets for this disease and innate immune pathways in other inflammatory conditions.
[0027] Accordingly, it is an object of the invention to provide a cell population comprising at least one cell, wherein said cell influences celiac disease. An exemplary cell population responds to gliadins. Further, an exemplary cell population produces cytokines, such as T H 17 cytokines. A further exemplary object of the invention is a cell population producing cytokines wherein said cytokines influence IL-1β. Another exemplary object of the invention is a cell population producing cytokines wherein said cytokines influence IL-1β, and wherein said population influences IL-1RA. The present invention also provides a pepsin-trypsin digest of gliadin (PTG) which induces production of IL-23 by a subset of monocytes with highest levels in CD patients on a gluten-free diet, intermediate levels from HLA-DQ matched monocytes from normal individuals, and lowest levels from monocytes from HLA-DQ mismatched normal individuals, and the relative levels of other cytokines involved in the T H 17 response network follow this same pattern. In one object, IL-1β production is also induced by PTG and temporarily precedes IL-23 production, and this cytokine alone induces IL-23 production while the IL-1 receptor antagonist inhibits IL-23 production generated by monocytes exposed to PTG. There is provided a non-limiting example of cytokine, pathway, genetic influence. In another object of the invention, the cytokine responses can only be generated with PTG and not with overlapping synthetic peptides from α-gliadin, but are also recapitulated with β-glucans from barley. An additional exemplary cell population produces chemokines.
[0028] A second object of the invention is a method influencing immunity in an individual with celiac disease. An exemplary method includes influencing T H 17 cytokines. Further, an exemplary method includes influencing innate immunity. An additional object of the invention is a method influencing immunity in an individual with celiac disease wherein IL-1β is influenced. Yet another exemplary object includes a method influencing immunity in an individual with celiac disease wherein IL-1RA is influenced. In one object, the present invention identifies, enumerates and compares the relative distribution of population(s) of monocytes, T cells, and their respective subsets associated with the IL 23/T H 17 pathway in peripheral blood mononuclear cells (PBMC) from patients with active and treated CD and HLA-DQ matched and HLA-DQ mismatched healthy individuals. In one object, the present invention determines if the array and magnitude of cytokine and chemokine responses to PTG and other agents that activate the IL-23/T H 17 innate immune response is different in PBMC obtained from patients with active and treated CD and HLA-DQ matched and HLA-DQ mismatched healthy individuals.
[0029] A third object of the invention is a composition for improving immune function, comprising an immune modulating component, comprising a first agent, wherein said first agent modulates immunity. An exemplary composition includes a first agent that influences celiac disease in a patient wherein said patient has at least one cell that responds to gliadins. Further, a therapeutic composition is an object of the present invention and comprises a first agent, wherein said first agent influences celiac disease in a patient wherein said patient has at least one cell that responds to gliadins. An exemplary therapeutic composition includes a first agent that inhibits at least one cell that responds to gliadins. An exemplary therapeutic composition includes a first agent that inhibits cytokine production of at least one cell that responds to gliadins.
[0030] A fourth object of the invention is a diagnostic method, comprising contacting at least one cell wherein said cell is obtained from an individual with celiac disease, further comprising contacting at least one cell wherein said cell is obtained from an individual without celiac disease, and further comprising comparing said cell from an individual with celiac disease to said cell from an individual without celiac disease. An exemplary diagnostic method includes influencing T H 17 cytokines. An exemplary diagnostic method includes influencing innate immunity.
[0031] A fifth object of the invention is a composition for improving immune function. An exemplary object of the invention includes a composition for improving immune function that includes an immune modulating component. An exemplary object of the invention includes a composition for improving immune function that includes an immune modulating component comprising a first agent, wherein said first agent modulates immunity, wherein said immunity involves IL-1β. An additional exemplary object of the invention is a composition for improving immune function, comprising an immune modulating component, comprising a first agent, wherein said first agent modulates immunity, wherein said immunity involves IL-1RA.
[0032] A sixth object of the invention includes a diagnostic method, wherein said method includes contacting at least one cell obtained from an individual with celiac disease and contacting at least one cell wherein said second cell is obtained from an individual without celiac disease, and comparing the cell (or cells) from an individual with celiac disease to a cell (or cells) from an individual without celiac disease. An exemplary embodiment includes a diagnostic method wherein cellular IL-1β from an individual without celiac disease is compared to IL-1β from an individual with celiac disease. An exemplary object of the invention also includes a diagnostic method comprising contacting at least one cell wherein said cell is obtained from an individual with celiac disease, further comprising contacting at least one cell wherein said cell is obtained from an individual without celiac disease, further comprising comparing said cell from an individual with celiac disease to said cell from an individual without celiac disease, and further comprising comparing IL-1RA from an individual without celiac disease to IL-1RA from an individual with celiac disease.
[0033] A seventh object of the invention includes a method of reducing inflammation in a subject with celiac disease comprising administering to said subject an IL-1 antagonist or an IL-1 inhibitor wherein said administering of said IL-1 antagonist or said IL-1 inhibitor reduces inflammation in said subject with celiac disease. An exemplary object of the invention includes a method of reducing inflammation, wherein the inflammation is IL-23 mediated. An exemplary object of the invention includes a method of reducing inflammation, wherein an IL-1 antagonist or an IL-1 inhibitor is administered and elicits a reduction of IL-23 or IL-1β. Yet another exemplary object of the invention includes a method of reducing inflammation, wherein said method includes administering an IL-1 antagonist or an IL-1 inhibitor that causes a reduction of IL-23. A further object of the invention includes a method of reducing inflammation, wherein said method includes administering an IL-1 antagonist or an IL-1 inhibitor and wherein said IL-1 antagonist or said IL-1 inhibitor is IL-1ra.
[0034] The objects of the present invention as summarized and taught herein are exemplary and non-limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 illustrates that subsets of mucosal DC regulate antigenic tolerance and immunity in the intestine. CX3CR1+ DC form tight junctions with IEC for continuous luminal sampling and populate the entire lamina propria and dome regions of Peyer's patches. CCR6+ DC reside in Peyer's patches and are recruited to the subepithelial dome region in response to pathogen-triggered CCL20 production. FAE means follicle associated epithelium.
[0036] FIGS. 2A-2E illustrate that monocytes are a major source of T H 17 cytokines triggered by exposure to PTG, however IFNγ treatment allows immDC to respond similarly. IL-23 data is shown as the mean of 5 independent experiments; IL-1β, TNFα, CCL20 and IL-6 are representative of 3 independent experiments. Exposure to β-glucan produced similar results.
[0037] FIGS. 3A-3D illustrate the obligatory role of IL-1 signaling in activation of IL-23 innate response in purified monocytes. Pretreatment with IL-1ra blocks PTG ( FIG. 3A ) and β-glucan ( FIG. 3B ) induced IL-23 production. Dose dependent IL-23 response to exogenous IL-1β alone in monocytes ( FIG. 3C ). IFN-γ treated DC response to PTG is independent of IL-1 signaling ( FIG. 3D ). FIG. 3B is one representative of four independent experiments. FIG. 3D represents one of three independent experiments.
[0038] FIGS. 4A-4E show that the CD14 low CD16 + subset of circulating monocytes is required for PTG-induced IL-1β and IL-23 production. Monocytes purified by elutriation were sorted into CD14 low and CD14 high subsets and cultured in the absence or presence of 100 ug/ml PTG for 24 h. Only the CD14 low CD16 + cells produced IL-1β and IL-23 upon exposure to PTG.
[0039] FIG. 5 illustrates CD14 low CD16 + cells increased in peripheral blood of CD patients in remission on GFD and decreased in CD patients with active disease.
[0040] FIGS. 6A-6E shows PBMC from healthy individuals produce IL-23 and additional cytokines/chemokines associated with induction of T H 17 cells upon exposure to PTG. Addition of IL-1ra inhibits PTG activation of the IL-23/T H 17 innate immune response, and β-glucan and IL-1β alone have the capacity to recapitulate this innate response. These data are representative of 6 independent experiments.
[0041] FIGS. 7A-7B illustrate kinetics and influence of HLA status on IL-23/T H 17 innate immune response pathway. After 24 h, PBMC from HLA-DQ2 positive healthy individuals produce substantially more IL-23 in response to PTG and β-glucan than HLA-DQ2 negative normal donors. Background levels were subtracted before plotting the effects of PTG or β-glucan.
[0042] FIGS. 8A-8C show gliadin-induced cytokine production is significantly higher in PBMC from CD patients than DQ2 + healthy individuals. Background levels from medium alone were subtracted from PTG before calculating the means.
[0043] FIG. 9 illustrates gliadin induces robust production of IL-23 and related proinflammatory cytokines in PBMC from CD patients. FIG. 9A shows PBMC from CD patients generate significantly higher amounts of IL-23, IL-1β and TNFα in response to PTG stimulation than HLA-DQ2 + healthy individuals. PTG substantially reduces secretion of the anti-inflammatory cytokine IL-1ra in CD patients but not in healthy individuals, and only stimulates significant levels of IL-6 in CD patients. PBMC from 7 CD patients and 6 HLA-DQ2 + healthy individuals (HD) were incubated with or without PTG (100 μg/ml) for 48 h, and cell-free culture supernatants analyzed for production of IL-1β, IL-1ra, IL-6, IL-12p70, IL-23 and TNFα. Together, these data illustrate that proinflammatory cytokine responses to PTG are augmented in HLA-DQ2 + individuals with CD compared to those without disease. Error bars indicate +s.d. FIG. 9B shows PTG stimulation of IL-23 and IL-1β production is dose dependent. PBMC from CD patients were cultured with or without 25, 100, 250 or 500 μg/ml PTG for 24 h. Increasing doses of β-glucan from barley served as a positive control. Concentrations of IL-23 and IL-1β were quantified by ELISA. Data represents mean values from 3 independent experiments. Error bars indicate +s.d.
[0044] FIG. 10 illustrates IL-1 cytokines regulate the IL-23 response in vitro. FIG. 10A shows that the addition of IL-1ra significantly inhibits IL-23 and IL-1β responses to PTG and the positive control, β-glucan. PBMC were incubated with or without 0.5 μg/ml IL-1ra for 1 h prior to stimulation with PTG or β-glucan for 20 h. Secretion of IL-23 and IL-1β were determined by ELISA. These data are mean values from 10 independent experiments. Error bars indicate +s.d. FIG. 10B shows IL-1β alone stimulates PBMC to produce IL-23, however its capacity to do so is much lower (˜10-fold) than that of PTG or β-glucan. PBMC were cultured in the absence or presence of 5 ng/ml IL-1β for 20 h, and supernatants tested by IL-23 ELISA. These results represent the mean of 10 independent experiments. Error bars indicate +s.d.
[0045] FIG. 11 illustrates that monocytes are the cell source of IL-23 and related proinflammatory mediators produced in response to in vitro gliadin stimulation. Highly purified lymphocytes, monocytes or monocyte-derived immDC were incubated with or without PTG (100 μg/ml) for 24 h, and supernatants analyzed for production of IL-1μ, IL-6 IL-23, TNFα and CCL20. PTG directly activates monocytes, and not lymphocytes or immature DC, to secrete IL-23. IL-1β, TNFα, IL-6 and CCL20 responses were also generated by monocytes exposed to PTG, and not their progeny DC. IL-23 data represent the mean of 5 independent experiments. IL-1β, TNFα and IL-6 data represent the means of 3 independent experiments. CCL20 data is one representative of 3 independent experiments. Error bars indicate +s.d.
[0046] FIG. 12 illustrates the IL-1 system regulates IL-23 production in human monocytes. FIG. 12A shows IL-1ra significantly inhibited IL-23 responses from monocytes exposed to PTG and the positive control, β-glucan. Highly purified monocytes were incubated with or without 0.5 μg/ml IL-1ra prior to addition of PTG or β-glucan for 20 h. These results represent the means of 5 independent experiments. Error bars indicate +s.d. FIG. 12B shows that IL-1β alone directly activates monocytes to secrete IL-23 in a dose dependent manner, however its capacity to do so is greatly reduced (˜10-fold) compared to that of PTG or β-glucan. Purified monocytes were treated with and without 0.5, 5 or 50 ng/ml rhIL-1β for 20 h, and culture supernatants were analyzed for IL-23 production. These results represent the means of 5 independent experiments. P values compare IL-1β data sets to medium alone. Error bars indicate +s.d.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0047] Unless otherwise noted, technical terms are used according to conventional usage. Definitions of common scientific technical terms may be found, for example, in McGraw-hill Dictionary of Scientific & Technical Terms published by McGraw-hill Healthcare Management Group; Benjamin Lewin, Genes VIII, published by Oxford University Press; Kendrew et al. (eds.), The Encyclopedia of Molecular Biology, published by Blackwell Publishers; and Robert A. Meyers (ed.), Molecular Biology and Biotechnology: a Comprehensive Desk Reference, published by Wiley, John & Sons, Inc; and other similar technical references.
[0048] As used herein, “a” or “an” may mean one or more. As used herein in the claim(s), when used in conjunction with the word “comprising”, the words “a” or “an” may mean one or more than one. As used herein “another” may mean at least a second or more. Furthermore, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.
[0049] As used herein, the term “agent” is a molecular entity including, for example, a small molecule (especially small organic molecules that satisfy the constraints of Lipinski's Rules (Lipinski, C. A. et al. (1997) “Experimental And Computational Approaches To Estimate Solubility And Permeability In Drug Discovery And Development Settings,” Adv. Drug Del. Rev, 23:3-25; Lipinski, C. A. et al. (2001) “Experimental And Computational Approaches To Estimate Solubility And Permeability In Drug Discovery And Development Settings,” Adv. Drug Del. Rev. 46,3-26; Oprea, T. I. et al. (2001) “Is There A Difference Between Leads And Drugs? A Historical Perspective,” J. Chem. Inf. Comput. Sci. 41:1308-1315; Arup, K. et al. (1999) “A Knowledge-Based Approach in Designing Combinatorial or Medicinal Chemistry Libraries for Drug Discovery,” J. Combin. Chem. 1:55-68), a nucleic acid (e.g., an oligonucleotide, and in particular, a siRNA, a shRNA an expression cassette, an antisense DNA, an antisense RNA, etc.), protein, peptide, antibody, antisense drug, or other biomolecule that is naturally made, synthetically made, or semi-synthetically made and is used alone or in combination with other therapies or methods for the treatment of a pathological condition of the invention (including, for example, a CD).
[0050] As used herein, an “IL-1 antagonist,” “IL-1 inhibitor,” or an obvious derivation thereof is an agent that is capable of reducing the effective amount of endogenous biologically active IL-1β, TNFα, or IL-23 by, for example, reducing the amount of IL-1β, or by inhibiting the binding of IL-1β to its receptor. In particular aspects, an IL-1 antagonist or IL-1 inhibitor is capable of reducing the effective amount of endogenous biologically active IL-23.
[0051] As used herein, “treat” and all its forms and tenses (including, for example, treat, treating, treated, and treatment) refers administering an agent of the invention to a subject in need thereof for both therapeutic treatment or prophylactic or preventative treatment. A subject in need of treatment includes those already with a pathological condition of the invention (including, for example, a CD) as well as those in which a pathological condition of the invention is to be prevented.
DESCRIPTION OF INVENTION
[0052] We are the first to correlate IL-23 mediated inflammation in the pathogenesis of CD. More than a decade of research has defined the T cell response to gluten-derived gliadin peptides in CD, yet the early events that initiate its activation are not well understood (Lundin et al., Hum. Immunol., 41:285-91 (1994); Tollefsen et al., J. Clin. Invest., 116:2226-2236 (2006); and van de Wal et al., Proc. Natl. Acad. Sci., U.S.A., 95:10050-10054 (1998)). The compromised intestinal epithelial barrier that characterizes CD allows gliadin access to the intestinal submucosa, where it must be acquired and processed by antigen presenting cells (APC) for presentation and activation of gliadin-specific CD4 + T cells. While augmented levels of zonulin and potent inflammatory cytokines IL-1β and TNFα have all been reported to increase intestinal permeability by disrupting the integrity of tight junctions in individuals with CD and other forms of inflammatory bowel disease (IBD), the precise mechanisms involved remain to be determined (Drago et al., Scand. J. Gastroenterol., 41:408-419 (2006); Al-Sadi et al., J. Immunol., 178:4641-4649 (2007); and Ma et al., Am. J. Physiol. Gastrointest. Liver Physiol., 286:G367-G376 (2004)).
[0053] A dynamic relationship between intestinal epithelial cells (IEC) and dendritic cells (iDC) regulates the processes of immunologic tolerance to harmless food and commensal antigens and adaptive immunity to pathogens (Kelsall et al., Immunol. Rev., 206:132-148 (2005)). The aberrant response to dietary glutens in CD immediately calls into question the maturation and activation state of iDC in these individuals. Indeed, a subset of activated lamina propria DQ2 + DC derived from circulating blood monocytes was recently implicated in the pathogenesis of CD (Raki et al., Gastroenterology, 131:428-438 (2006)). Moreover, circulating monocytes from CD patients have been demonstrated to produce substantially more TNFα and IL-8 in response to gliadin than monocytes from healthy individuals (Cinova et al., J. Clin. Immunol., 27:201-209 (2007)). Together, these findings suggest that CD ultimately results from accumulation of normally quiescent circulating monocytes that are activated upon encounter with gliadin in the gut.
[0054] Monocytes and their progeny are integral components of the innate immune system. In response to environmental antigens, conserved pattern recognition receptors (PRR) trigger cytokine production directing the immune response to the encountered antigen (Williams et al., Leuk. Lymphoma., 34:1-23 (1999)). New evidence shows that activated monocytes producing IL-1β and IL-23 are the most potent stimulators of the memory subset of pathogenic T helper cells (termed Th17) that secrete tissue destructive cytokines IL-17, IL-21 and IL-22 (Acosta-Rodriguez et al., Nat. Immunol., 8:942-949 (2007); Steinman, Nat. Med., 13:139-145 (2007); and McKenzie et al., Trends Immunol., 27:17-23 (2006)).
[0055] IL-1 was one of the first cytokines to be described and has since proved to be an important mediator of multiple immunologic processes throughout the body, including inflammatory conditions in the gut (Ligumsky et al., Gut, 31:686-689 (1990)). The IL-1 family consists of proinflammatory cytokines IL-1α and IL-1β and anti-inflammatory IL-1ra, which prevents IL-1 signaling by binding the active IL-1 receptor (IL-1RI) (Schreuder et al., Nature, 386:194-200 (1997)). An imbalance between IL-1β and IL-1ra, resulting from amplified levels of IL-1β has been associated with inflammation in CD (Fornari et al., Am. J. Gastroenterol., 93:413-418 (1998)). Interestingly, elimination of dietary glutens significantly increases levels of IL-1ra in these individuals without substantially altering IL-1β, suggesting that individuals with CD inherently produce more IL-1β and IL-1ra, and that dietary glutens may induce inflammation by shifting the balance toward IL-1β in individuals with CD.
[0056] IL-23 is a relatively new inflammatory cytokine composed of the IL-12/23p40 subunit and the IL-23p19 protein that is preferentially secreted in specific tissues by APC (Oppmann et al., Immunity, 13:715-725 (2000); and Uhlig et al., Immunity, 25:309-318 (2006)). It perpetuates chronic inflammation by stimulating both adaptive and innate cells to produce additional proinflammatory mediators (Hue et al., J. Exp. Med., 203:2473-2483 (2006)). CD has been considered a typical Th1 disease, however emergence of the IL23-Th17 paradigm has prompted reanalysis of cell-mediated tissue damage previously attributed to the IL12-Th1 axis, and emphasized the decisive role of the innate arm in adaptive immunity. Although novel studies have detected augmented levels of IL-23 in rheumatoid arthritis, psoriasis. Crohn's disease, ulcerative colitis and multiple sclerosis, and other cytokines associated with Th17-mediated inflammation (IL-1β, IL-6, IL-15 and TNFα) have been implicated in the pathogenesis of CD, an association with IL-23 has not yet been reported (Fornari et al., Am. J. Gastroenterol., 93:413-418 (1998); Kim et al., Scand. J. Rheumatol., 36:259-264 (2007); Becker et al., J. Clin. Invest., 112:693-706 (2003); Piskin et al, J. Immunol., 176:1908-1915 (2006); Cua et al., Nature, 421:744-748 (2003); J. Invest. Dermatol., 127:2495-2497 (2007); Yen et al., J. Clin. Invest., 116:1310-1316 (2006); Chowers et al., Clin. Exp. Immunol., 107:141-147 (1997); and Thomas et al., J. Immunol., 176:2512-2521 (2006)).
[0057] Given the strong genetic requirement associated with CD, we investigated gliadin's capacity to activate the IL-23 pathway in HLA-DQ2 + individuals with and without CD. We predicted that gliadin would induce increased levels of IL-23 and related inflammatory cytokines in HLA-DQ2 + individuals with CD compared to healthy individuals. To test this hypothesis, we exposed PBMC from CD patients and HLA-DQ2 + healthy individuals to a pepsin-trypsin digest of gliadin (PTG) and analyzed culture supernatants for IL-1β, IL-1ra, IL-6, IL-12p70, IL-23 and TNFα. We discovered that PTG stimulated production of IL-23, IL-1β, IL-6 and TNFα and reduced secretion of IL-1ra in all donors tested, however levels of IL-1β, IL-23, IL-6 and TNFα were significantly higher, and IL-1ra substantially reduced, in CD patients ( FIG. 1A ). Importantly, PTG did not induce IL-12p70 in any of the donors tested (negative data not shown). These results confirm that gliadin stimulates robust production of IL-1β and TNFα in individuals with CD (Cinova et al., J. Clin. Immunol., 27:201-209 (2007); and Fornari et al., Am. J. Gastroenterol., 93:413-418 (1998)) and demonstrate gliadin's ability to disrupt the balance between IL-1β and IL-1ra by simultaneously inducing high levels of IL-1β and decreased levels of IL-1ra. Moreover, our novel findings strongly advocate a role for IL-23 mediated inflammation in the pathogenesis of CD.
[0058] In order to demonstrate that production of these potent mediators depended on gliadin exposure, dose response curves were generated with PTG or β-glucan, an agent known to activate the IL-23 pathway. Both stimuli induced dose-dependent production of IL-1β and IL-23, although PTG proved to be far more effective as evidenced by detectable levels of IL-23 achieved with 100 μg/ml versus 500 μg/ml of β-glucan ( FIG. 1B ). These stimulatory effects of PTG were not due to endotoxin contamination, since the presence of LPS in this preparation of PTG was ruled out in earlier studies (Thomas et al., J. Immunol., 176:2512-2521 (2006)).
[0059] Several immunodominant epitopes of α-gliadin that preferentially bind HLA-DQ2 and DQ8 molecules as well as an innate peptide p31-43 have been implicated in the pathogenesis of CD (Maiuri et al., Lancet, 362:30-37 (2003)). To determine if any of these epitopes were involved in activation of the innate immune response, we incubated PBMC with synthetic overlapping peptides spanning the entire sequence of α-gliadin. None of the overlapping peptides tested individually or in combination stimulated secretion of IL-1β or IL-23, indicating that other subtypes of gliadin (γ- or ω-gliadin) or additional properties of gliadin are required for induction of these cytokines (negative data not shown). Since gliadin is a glycoprotein and β-glucan recapitulates the inflammatory cytokine response generated by PTG, posttranslational modifications are likely necessary for pattern recognition and activation of APC.
Methods of Treatment
[0060] In particular aspects of the invention, methods of treatment are drawn to inhibiting the innate immune response that is responsible for causing cell injury or dysfunction in autoimmunity. In further particular aspects, inhibiting the innate immune response is inhibiting IL-23 mediated inflammation in autoimmunity. IL-23 mediated inflammation in autoimmunity can be the cause of cell injury or dysfunction in autoimmunity in a number of diseases, including, for example, rheumatoid arthritis, Crohn's disease, lupus, Hashimoto's thyroiditis, Sjogren's syndrome, multiple sclerosis, Graves' disease, Guillain-barre, ulcerative colitis, psoriasis, and CD. In certain aspects of the invention, IL-23 mediated inflammation in autoimmunity is a cause of cell injury or dysfunction in CD. As described herein and throughout the specification, the inventors are the first to describe IL-23 mediated inflammation in the pathogenesis of CD. The inventors are also the first to demonstrate that the IL-1 system regulates IL-23, and illustrate the powerful anti-inflammatory effects of IL-1ra on induction of IL-23. These two novel findings support novel methods of treating CD. Such methods include, for example, a method comprising administering an IL-1 antagonist or IL-1 inhibitor to a subject in need thereof.
[0061] An IL-1 antagonist or IL-1 inhibitor of the invention include, for example, a receptor-binding peptide fragment of IL-1, an IL-1, IL-1β or IL-1 receptor antibody, an IL-1ra polypeptide, an IL-1β converting enzyme (ICE) inhibitor (US Patent Application Publication No. 20090022733); IL-1ra (KINERET); sIL-1ra, icIL-1raI, icIL-1raII, and other IL-1 receptor antagonists described in U.S. Pat. No. 5,739,282; rilonacept (U.S. Pat. No. 6,927,044 and US Patent Application Publication No. 20090123446); IL-1β binding antibody or IL-1β binding fragment that bind selectively to IL-1β (U.S. Pat. No. 7,491,392 and US Patent Application Publication No. 20090060923); a human IL-1 receptor type 1 antibody (U.S. Pat. No. 7,438,910); a noncompetitive antagonist of IL-1 receptor, including RYTVELA (SEQ ID NO:1), MKLPVHKLY (SEQ ID NO:2), VGSPKNAVPPV (SEQ ID NO:3), AND WTLDGKKPDDL (SEQ ID NO:4) (Quiniou et al. J Immunol. 2008 May 15;180(10):6977-87).
[0062] In certain aspects of the invention an IL-1ra polypeptide includes a form of IL-1ra described in U.S. Pat. No. 5,075,222 and modified forms and variants including those described U.S. Pat. No. 5,922,573, and PCT Patent Application Publication Nos. WO 91/17184, WO 92 16221, and WO 96 09323; IL-1β converting enzyme (ICE) inhibitors include peptidyl and small molecule ICE inhibitors including those described in PCT Patent Application Publication Nos. WO 91/15577, WO 93/05071, WO 93/09135, WO 93/14777 and WO 93/16710, and European patent application 0 547 699; non-peptidyl compounds include those described in PCT Patent Application Publication No. WO 95/26958, U.S. Pat. Nos. 5,552,400, 6,121,266, and Dolle et al., J. Med. Chem., 39, pp. 2438-2440 (1996); and additional ICE inhibitors are described in U.S. Pat. Nos. 7,417,029, 6,162,790, 6,204,261, 6,136,787, 6,103,711, 6,025,147, 6,008,217, 5,973,111, 5,874,424, 5,847,135, 5,843,904, 5,756,466, 5,656,627, 5,716,929. Said references are incorporated by reference herein in their entireties.
Cell Source of IL-23/T H 17 Innate Response to PTG
[0063] PTG Directly Stimulates the Production of T H 17-Related Cytokines in Monocytes
[0064] IL-23 is only secreted by activated APC such as monocytes, macrophages and DC, which reduces the number of possible cell sources considerably. To determine which of these cell populations was the source of IL-23 in response to PTG, purified lymphocytes, monocytes, or monocyte-derived DC cultured with GM-CSF and IL-4, were incubated in the presence or absence of PTG for 24 h, at which time supernatants were collected for IL-23, IL-1β, IL-6, IFNγ and TNFα analysis. Under these conditions, both PTG- and β-glucan-induced secretion of IL-23, IL-1β, CCL20, TNFα and IL-6 was confined to monocytes, identifying a readily available target population for further investigation, and indicating a direct interaction of PTG with its PRR(s) whose expression must be limited to this population ( FIGS. 2A-2E ). Since neither PTG nor β-glucan activated cytokine production in DC differed from monocytes, we examined the response after pretreatment with IFNγ, given that this treatment has been necessary for the IL-23 response to a variety of agents including β-glucan. immDC were cultured in the presence or absence of IFNγ for 18 h prior to addition of PTG, after which supernatants were subjected to cytokine analysis as described above. Similar to monocytes, IFNγ-treated immDC produced IL-23, IL-6, TNFα and CCL20 in response to PTG, implying that IFN-γ upregulates the PRR(s) or cytoplasmic signaling components required for the response in immDC, and calls into question the properties of PTG and its cognate PRR expressed on monocytes and IFNγ-treated immDC mediating this response. In contrast to monocytes, the magnitude of the immDC response was notably reduced and lacked IL-1β altogether, suggesting that PTG activates distinct signaling cascades in the different cell types that ultimately determine the fate of the adaptive immune response to PTG ( FIGS. 2A-2E ). Moreover, these findings provide insight to the mechanisms in which IFNγ counteracts IL-1 dependent T H 17 responses.
[0065] IL-1β Regulates the IL-23/T H 17 Innate Immune Response Triggered by PTG in Monocytes
[0066] To better understand the contribution of IL-1 signaling in the IL-23/T H 17 innate response to PTG in monocyte and immDC populations, we pretreated monocytes, immDC and IFNγ-treated immDC with the naturally occurring anti-inflammatory IL-1 receptor antagonist (IL-1ra) for 1 h prior to stimulation with PTG or β-glucan as a positive control, or incubated with increasing doses of exogenous IL-1β for 20 h. Addition of IL-1ra drastically inhibited the IL-23, TNFα, IL-6, and CCL20 responses to PTG in monocytes, demonstrating the influential role of autocrine IL-1 signaling in monocyte-derived IL-23/T H 17 innate immune responses ( FIG. 3A ). The requirement for IL-1 appears to be a general phenomenon of this pathway in monocytes, since IL-1ra also inhibited the cytokine response to the positive control β-glucan ( FIG. 3B ), and the IL-23 response to exogenous IL-1β was dose dependent ( FIG. 3C ). Similar effects were observed for the other cytokines/chemokines. Contradictory to the monocyte response, addition of IL-1ra or IL-1β to IFNγ-treated immDC had no effect on the IL-23/T H 17 profile induced by PTG exposure ( FIG. 3D ), providing further indication that monocytes exposed to gluten and not their progeny DC have the potential to activate autoreactive memory T H 17 cells. Indeed, other groups have reported in human studies that activated monocytes, which produce IL-1β and IL-23, are the best inducers of T H 17 cells (Evans et al., Proc. Natl. Acad. Sci., U.S.A., 104(43):17034-17039 (2007)).
[0067] Subtypes of Monocytes Required for the IL-1β and IL-23 Response to PTG
[0068] The minor CD14 low CD16 + subtype of monocytes has a greater capacity to produce TNFα, IL-1β and IL-6, and is expanded in conditions of chronic inflammation such as autoimmune disease. Given the proinflammatory nature of this subset, and the similar cytokine profile triggered by PTG in monocytes, we investigated the involvement of CD14 low CD16 + cells in our in vitro model of the IL-23/T H 17 innate immune response to PTG. Elutriated monocytes were stained with αCD14-PE mAb and sterile sorted based on high and low expression of CD14 since the majority of CD16 + cells are CD14 low and αCD16 monoclonal antibody reportedly alters their function ( FIGS. 4A-4E ). Equal numbers of CD14 high , CD14 low or unsorted control monocytes were incubated in the presence or absence of 100 ug/ml PTG for 20 h, and cell free supernatants were analyzed for IL-1β and IL-23 (ELISA). Remarkably, only CD14 low CD16 + monocytes produced IL-1β and IL-23 in response to stimulation with PTG, providing a more specific target population that can be exploited for further investigation of the receptors and signaling mechanisms involved ( FIGS. 4A-4E ).
[0069] Compare the proportion of populations of monocytes, T cells, and their respective subsets associated with the IL-23/T H 17 pathway in PBMC from patients with active and treated CD and HLA-DQ matched and HLA DQ mismatched healthy individuals.
[0070] Increased CD14 low CD16 + Monocytes in CD Patients
[0071] Given that this subset is expanded in other autoimmune diseases and has been observed in active celiac lesions, together with our novel discovery that this subset is required for the IL-23/T H 17 innate immune response, we further investigated the proportion of this subset. Freshly thawed PBMC from CD patients with active and treated disease and HLA matched and mismatched normals were stained with monoclonal Abs to CD11c, CD14 and CD16, or appropriate isotype controls and analyzed by flow cytometry. The proportion of CD14 low CD16 + monocytes was considerably highest in the CD patient with treated disease and lowest in the CD patient with active disease ( FIG. 5 ), which can be explained by the increase of this subset in the intestinal tissues of CD patients exposed to gluten (Raki et al., Gastroenterology, 131(2):428-438 (2006)).
[0072] Effect of gliadin on PBMC from treated and active CD patients and HLA-matched and mismatched healthy donors.
[0073] Influence of HLA class II Alleles on Gliadin-Induced T H 17 Related Cytokines/Chemokines
[0074] Given the HLA requirement for CD, together with the knowledge that gliadin activates the proinflammatory cytokines TNFα and IL-8 in PBMC from healthy individuals, we evaluated its capacity to stimulate T H 17 related cytokines in HLA-matched and mismatched healthy subjects.
[0075] We cultured PBMC from HLA-DQ2 positive and HLA-DQ2 negative healthy persons in the presence or absence of 100 ug/ml of PTG or β-D-glucan from barley as a positive control for 20 h. Cell-free culture supernatants were harvested and analyzed for proinflammatory cytokines IL-1β, IL-6, IFNγ, TNFα (Luminex) IL-23 and the T H 17 chemokine CCL20/MIP-3α (ELISA). PTG stimulated production of IL-23, IL-1β, IL-6, TNFα and CCL20, and not the IL-17 inhibitor IFNγ in all donors tested, illustrating the ability of PTG to induce the IL-23/T H 17 innate immune response ( FIGS. 6A-6E ).
[0076] Interestingly, PTG and β-glucan had a more pronounced effect on PBMC from HLA-DQ2 + healthy individuals, suggesting a positive correlation between the HLA-DQ alleles required for CD and the intensity of the IL-23/T H 17 innate immune response ( FIGS. 7A-7B ). Kinetic studies evaluated after 6, 24, 48 and 72 h exposure to PTG revealed secretion of IL-1β, IL-6 and TNFα as early as 6 h, while IL-23 was not detected until 24 h at which time it reached peak levels and declined steadily thereafter ( FIGS. 7A-7B ). Considering the essential role for IL-1β in the IL-23/T H 17 innate response in purified monocytes, we predicted that IL-1β regulates the cytokine profile triggered by PTG and β-glucan in whole PBMC as well. To this end, PBMC were pretreated with IL-1ra for 1 h prior to stimulation with PTG or β-glucan, or incubated with 5 ng/ml IL-1β alone for 20 h. Indeed, IL-1ra almost completely inhibited IL-23, TNF-α, IL-6, and CCL20 responses to PTG and β-glucan, implying that IL-1 signaling was required for production of these potent mediators. IL-1ra also reduced the IL-1β response by ˜60%, indicating a positive feedback loop wherein the initial burst of IL-1β released upon engagement of PTG with its anonymous PRR perpetuates IL-1β secretion. Moreover, exogenous IL-1β generated a similar profile as PTG producing equivalent concentrations of CCL20 and IL-6, but reduced levels of IL-23 and TNFα suggesting that the complex cytokine milieu triggered by PTG enhance the IL-23 and TNFα responses ( FIGS. 6A-6E ).
[0077] The Cytokine Response to Gliadin is Augmented in CD Patients on GFD Compared to HLA-DQ2 Matched Healthy Individuals
[0078] Considering the role of the IL-23/T H 17 pathway in autoimmune diseases sharing the disease-associated HLA class II alleles, and our novel discovery that PTG stimulates this innate immune response in PBMC of healthy subjects, we tested the hypothesis that PTG activates the IL-23/T H 17 pathway differently in individuals with CD compared to healthy individuals. We incubated PBMC from CD patients on a GFD in remission and PBMC from HLA-matched healthy donors in the presence or absence of PTG, and quantified levels of IL-1β, IFNγ, TNFα (Luminex) and IL-23 (ELISA) from cell-free culture supernatants after 48 h. Significantly elevated levels of IL-23, IL-1β and TNFα were detected in culture supernatants from PBMC from the CD patients, indicating a role for the IL-23/T H 17 paradigm in the pathogenesis of CD ( FIGS. 8A-8C ). A correlation between the proportion and activation status of cell subsets involved in the IL-23/T H 17 axis and the differential cytokine response to PTG was observed.
[0079] We discovered the involvement of IL23-mediated inflammation in the pathogenesis of CD and address a number of unresolved questions pertinent to the long felt need, such as: Is there a role for HLA-DQ2 (and/or -DQ8) or linked genes in the activation of this innate immune response? What is responsible for the difference in the response observed in CD patients vs. healthy subjects with the same HLA genotype? Does this innate immune response control the balance between chronic inflammation and tolerance to a food stuff that is consumed by the population at large, but causes disease in those genetically predisposed? What is the constituent(s) in gliadin that initiates the production of cytokines and chemokines that characterize the IL-23/T H 17 response and what PRR on APC interacts with this constituent? What genes are expressed as a result of the PRR-ligand interaction?
EXAMPLES
[0080] We used several approaches to test the overall hypothesis that the IL-23/T H 17 innate immune response axis is activated by exposure of defined populations of APC to gliadin proteins, and that this innate immune response plays a fundamental role in the pathogenesis of CD in genetically predisposed individuals.
Example 1
[0081] We identified the subset of monocytes and/or immature DC that produce IL-23 and related T H 17 cytokines in response to PTG exposure. Highly purified monocytes from our inventory of healthy individuals will be used to investigate this AIM. Elutriated monocytes are obtained from the apheresis products of healthy individuals and cryopreserved until used. Freshly thawed monocytes will be sorted into CD14 hi and CD14 low subsets or cultured with GM-CSF and IL-4 to make immDC that will be incubated for an additional 18 h in the presence or absence of IFNγ. Unsorted monocytes, monocyte subsets, immDC and IFNγ-treated immDC will be exposed to PTG with and without IL-1ra, β-glucan or IL-1β for 20 h. Cell-free culture supernatants will be harvested and analyzed for cytokine/chemokine production by ELISA.
[0082] Isolation of subsets of monocytes: Subsets of monocytes will be separated by sterile flow cytometry cell sorting. Cells are incubated with fluorochrome-conjugated CD14 antibody for 15 minutes at 27 C, washed and resuspended in FACS buffer (PBS with 1% huAB serum) and sorted in CD14 high , CD14 low and CD14 − subsets on a BD FACSVantage cell sorter.
[0083] Antigens: Gliadin will be prepared by enzymatic digestion as described previously (Thomas et al., J. Immunol., 176(4):2512-2521 (2006)). Briefly, 50 g of gliadin (crude wheat; Sigma-Aldrich) is dissolved in 500 ml of 0.2 N HCl for 2 h at 37° C. with 1 g of pepsin (Sigma-Aldrich). The resultant peptic digest is further digested by the addition of 1 g of trypsin (Sigma-Aldrich) after the pH was adjusted to 7.4 using 2 M NaOH. The solution is stirred vigorously at 37° C. for 4 h, boiled (100° C.) for 30 min, freeze-dried, lyophilized in 10-mg aliquots, and stored at −20° C. until use (referred to as pepsin/trypsin-digested gliadin or (PTG). 100 mg of β-D-glucan from barley (Sigma-Aldrich) is dissolved in 600 ul 95% EtOH followed by 9 mL distilled water. The resultant slurry is then stirred vigorously at 100° C. for 3 min. or until completely dissolved, allowed to cool, and stored at 10 mg/ml at 4° C. until used.
[0084] ELISA Cytokine Assays: Cytokine levels are quantified using IL-23 (eBioscience) or Quantikine ELISA kits (R& D Systems) following the manufacturers' protocol. Briefly, samples and standards (100 ul) are added to each well in duplicate and incubated at room temperature (RT) for 2 hrs. Wells are washed four times with wash buffer. Conjugate is added to each well and incubated for 1-2 hrs at RT. After washing four times, substrate solution is added to each well and the plate is incubated for 15-30 min at RT. The reaction is stopped by adding 50 ul of stop solution to each well and the OD 450 nm read.
[0085] The CD14 low (CD16 + ) monocyte population generate an IL-1 dependent IL-23/T H 17 innate response with exposure to PTG, β-glucan and IL-1β. IFNγ-treated immDC will produce IL-23 and related cytokines (except for IL-1β) independently of IL-1β in response to PTG, and immDC not exposed to IFNγ will not recapitulate the IL-23/T H 17 response to these antigens.
[0086] Variables introduced by genetic diversity, lifestyle and environment, blood sample collection and processing, and the cell sorting process could impact the phenotype and function of monocytes in vitro. Monocyte subsets are magnetically depleted from whole PBMC or elutriated monocytes, and the untouched cells tested for reactivity to PTG and β-glucan. Intracellular cytokine staining is used to identify the subsets producing IL-1β in response to antigens, since an appropriate antibody for detecting IL-23 is not currently available.
Example 2
[0087] We identified, enumerated and compared the proportion of monocytes that produce IL-23 in response to PTG and the number of T H 17 cells in PBMC obtained from patients with active and treated CD and HLA-DQ matched and HLA-DQ mismatched normal individuals.
[0088] Peripheral blood samples are obtained from patients. Disease, treatment status as well as relationship to other donors are recorded. Peripheral blood samples are obtained from patients with untreated disease, treated (on a gluten-free diet), HLA-DQ2/DQ8 + and HLA-DQ2/8 − individuals that are disease free. The laboratory investigators are blinded to this information until after completion of the following tests. Serum samples from all study subjects are tested for antibodies to tissue transglutaminase (tTG). PBMC are isolated from whole blood, for example by density gradient centrifugation, and DNA extracted from a portion of the cells for high resolution HLA class II allele typing (HLA-DRB1, DQA1 and DQB1) and future molecular studies. The remainder and the majority of the PBMC will be cryo-preserved by control rate freezing and stored in the vapor phase of liquid nitrogen until used.
[0089] PBMC Cryopreservation: Peripheral blood mononuclear cells are isolated from donors' whole blood, for example by density gradient centrifugation in Lymphocyte Separation Medium (ICN Biomedicals Inc., Aurora, Ohio). These cells will be viably cryopreserved, for example in RPMI-1640 media (Invitrogen Corp., Grand Island, N.Y.) containing 20% human AB serum (Gemini Bioproducts, Woodland, Calif.) and 10% Dimethylsulfoxide (Sigma, St Louis, Mo.) or other suitable media using an automated cell freezer (Gordinier Electronics, Roseville, Mich.) and stored in the vapor phase of liquid nitrogen until used.
[0090] Combinations of fluorochrome-conjugated antibodies and flow cytometric technology are used to identify cells and subsets of cells of the various lineages in PBMC obtained from patients and controls. To identify and enumerate B cells, suitable targets include CD19, CD27; NK cells, suitable targets include CD3, CD56; T cells and T cell subsets, suitable targets include CD3, CD4, CD8, CD56, αβTCR, γδTCR, CD45RO, CD45RA, IL1R, IL23R, CCR6, CXCR3 and activation status suitable targets include CD25 and CD69; monocytes/dendrites cells suitable targets include CD11c, CD1a, CD14, CD16, CD32, CD64, CD123, HLA-DR, HLA-DQ, HLA-DP, CD40, CD80, CD86, CD83, TLR2, CX3CR1, CCR2, GM1, CCR6. Data is analyzed comparing the relative distribution of different cell lineages and lineage subsets. While the analysis is focused on the differences in the numbers of T H 17 cells (CD4 + CD45RO + IL23R + CCR6 + IL1R + ) and the CD16 + CD14 + monocyte subset in the patients and controls, this systematic comparison of the distribution of mononuclear cells provides a baseline for functional studies.
[0091] Flow Cytometry: Cells are labeled using flow cytometry methodology. Briefly, cells are washed in RPMI containing 5% hAB, and incubated for 15 minutes at room temperature (22-25° C.) in order to block Fc receptors. After an additional wash, (1×PBS with 1% FBS and 0.1% NaN 3 ) fluorochrome-conjugated antibodies are added (BD Biosciences, San Diego, Calif.) and the cells incubated for 30 minutes at 4° C., washed again and fixed in 1×PBC with 1% paraformaldehyde. Flow cytometric data are acquired using a BD™ FACS SCAN flow cytometer and analyzed with CellQuest Software (Becton Dickinson, San Jose, Calif.).
[0092] We see a significant difference in the relative numbers of circulating cells that express the combinations of markers that identify the monocyte population that produces IL-23 and other T H 17 related cytokines in response to PTG. The highest number of will be found in treated celiac patients, with lower numbers in patients among other groups. Our model hypothesizes that the monocyte population that produces IL-23 and other T H 17 related cytokines in response to PTG localize in the gut and are particularly abundant in patients with active disease thus lower numbers in circulation. In studies determining the phenotype of the T cell populations in the four groups, we see the highest numbers of the CD4 + cells with the T H 17 phenotype (CD45RO, IL23R, CCR6) in CD patients with active disease and these numbers lowered as the patients are followed after a change in diet to reduce or eliminate gliadins.
[0093] Phenotyping of intestinal tissue from patient populations is done using an inventory of paraffin-embedded intestinal biopsies from an Amish cohort of related individuals with and without CD that will be available for study.
Example 3
[0094] The magnitude and array of cytokine/chemokine responses to PTG is different in active and treated CD patients from that observed in PBMC from HLA-DQ matched and HLA-DQ mismatched normal individuals.
[0095] PBMC from patients and controls are exposed to PTG, IL-1β, IL-1 receptor antagonist, and β-glucan for 6, 24, 48 and 72 hours, and the culture supernatants are harvested for cytokine analysis. The cell-free culture supernatants are assayed for the presence and quantity of cytokines, such as IL-1, IL-23, IL-21, IFNγ, TNFα, IL-6, IL-8, IP-10, IL-2, IL-10, IL-4, MIP3α, IL-17 (A-F) and IL-27 in ELISA assays or alternatively in multiplex cytokine/chemokine assays. These experiments are initially on PBMC from subjects in different groups to determine if the kinetics of response is similar or different. Using the information obtained from these kinetic studies, we select the conditions and the length of culture that provides optimal information when PBMC from other individuals in each of the groups are tested. The rational for selecting IL-1β and its natural inhibitor comes from our observation that production of this cytokine precedes production of IL-23, and that the presence of IL-1ra abrogates the IL-23 response induced by PTG. β-glucans activate the IL-23/T H 17 innate immune response. Inclusion of IL-23 is a positive control as our results indicate that the response of PBMC to β-glucan exposure is similar to the response observed when the same cells are exposed to PTG.
[0096] Antigens and ELISA Methods
[0097] Bio-Plex Human Cytokine Assay: Cytokines from cell culture supernatants are detected and quantified using various commercially available kits and reagents, including Bio-Plex Cytokine Assay kits (Bio-Rad). Briefly, a premixed standard is reconstituted in the same culture media as that used for the sample and incubated on ice for 30 minutes. Serial dilutions of the stock are prepared to give a total of eight standards. Cell culture supernatants are diluted and kept on ice until ready to use. Premixed beads (50 ul) coated with target capture antibodies are transferred to each well of a filter plate and washed twice with buffer. The premixed standards and samples (50 ul) are added to each well. The plate is shaken for 30 sec. and incubated for 30 minutes at RT with shaking at 300 rpm. After washing, premixed detection antibodies (50 ul) are added to each well and shaken at RT for an additional 10 minutes. After 3 washes, the beads are resuspended in 125 ul of Bio-Plex assay buffer. The plate is then read on the Bio-Plex suspension array system and analyzed using Bio-Plex Manager software.
[0098] Having identified the cytokines/chemokines produced by PBMC from the different cohorts, studies are conducted to determine the population of cells producing the lymphokines. PBMC are exposed to PTG, IL-1β and β-glucan in culture for the period of time that was determined to produce the peak amounts of the cytokines/chemokines and the cells producing the cytokine and/or chemokines identified using intracellular staining and flow cytometric methods.
[0099] Detection of intracellular cytokine expression by flow cytometry: Intracellular cytokine production by sub-populations of PBMC is measured by flow cytometry. For example, cells are stimulated with the selected antigen (or mitogen) for 2 hours at 37° C., 5% CO 2 in a humidified incubator. Golgi Stop (10 μg/ml) (Pharmingen, San Diego, Calif.) is added for an additional 4 hours of incubation. Cells are washed with blocking buffer (PBS with 5% human AB serum), resuspended in the buffer and incubated for 15 minutes at 4° C. to block Fc receptors. The cells are washed with staining buffer (PBS with 1% human AB serum) and incubated with fluorochrome labeled antibodies detecting cell surface markers or appropriate isotype controls (Becton Dickinson, San Jose, Calif.) at 4° C. for 25 minutes in the dark. After washing, cells are fixed and permeabilized by incubation with 250 ul perm/fix solution (Pharmingen, San Diego, Calif.) for 25 minutes at 4° C., then washed with perm wash buffer. The fluorochrome labeled monoclonal for intracellular cytokines or appropriate isotype control antibodies are then added (Pharmingen, San Diego, Calif.) and incubated at 4° C. for 25 minutes in the dark. The cells are again washed, resuspended in 200 ul perm wash buffer and analyzed by flow cytometry.
[0100] The array and magnitude of cytokines/chemokines differ in PBMC from CD patients with active disease, patients on a disease free diet and controls. We see differences depending on HLA class II type in control populations. The levels of cytokine/chemokine production in response to PTG exposure corresponds to the numbers of CD16 + monocytes. The responses observed will be replicated when PBMC are exposed to β-glucans and addition of IL-1ra shuts down production of all of the cytokines involved in the innate immune response regardless of the agent that was used to induce the response. A central role for IL-1β or its receptor in the initiation of the IL-23/T H 17 pathway is established, thus therapeutic options are available.
Example 4
[0101] The kinetics of cytokine responses to PTG was determined by exposing PBMC to PTG for 6, 24, 48 and 72 h. These studies revealed that IL-1β, IL-6 and TNFα were secreted in as few as 6 h following PTG exposure, while IL-23 could not be detected until 24 h, suggesting that induction of IL-23 required earlier inflammatory mediators (data not shown). During these initial studies, we also observed a positive correlation between IL-1β and IL-23, which led us to hypothesize that IL-1 is essential for production of IL-23. To directly examine the role of IL-1β in IL-23 responses, we treated PBMC from CD patients with IL-1ra prior to stimulation with PTG or the positive control, β-glucan. IL-1ra completely inhibited induction of IL-23 in response to both PTG and β-glucan, illustrating the fundamental role of IL-1 signaling in IL-23 production ( FIG. 10A ). IL-1ra also markedly reduced levels of IL-1β in PBMC treated with both antigens, suggesting that IL-1β released upon engagement of PTG or β-glucan with their respective pattern recognition receptor (PRR) perpetuates production of IL-1β and facilitates induction of IL-23 ( FIG. 10B ). Additionally, PBMC were treated with physiologic concentrations of exogenous IL-1β in order to ascertain its direct effects on cytokine production. Importantly, IL-1β alone induced IL-23 production at much lower levels than PTG and β-glucan, indicating that additional signaling pathways triggered by these antigens enhance secretion of IL-23 ( FIG. 10B ). The invention demonstrates for the first time that the IL-1 system regulates IL-23, and illustrate the powerful anti-inflammatory effects of IL-1ra on induction of IL-23.
[0102] While IL-1β is produced by many cell types, IL-23 production is thought to be restricted to activated APC. Recently, TLR activated monocytes were shown to secrete high levels of IL-23 and to be the best inducers of Th17 cells 14 , thus we predicted that monocytes were the cellular source of PTG-induced IL-23. To investigate this hypothesis, we exposed purified lymphocytes, monocytes, or monocyte-derived DC (cultured with GM-CSF and IL-4 for 72 h) to PTG overnight and analyzed the cell-free culture supernatants for IL-23 and related “Th17” polarizing mediators. Under these conditions, monocytes and not their progeny DC or lymphocytes produced IL-23, IL-1β, IL-6, TNFα and CCL20 in response to PTG, demonstrating a direct interaction between PTG and its anonymous PRR(s) on this population ( FIG. 11 ).
[0103] As with whole PBMC, IL-1ra significantly inhibited IL-23 responses to PTG and β-glucan in purified monocytes ( FIG. 12A ), and addition of exogenous IL-1β to this subset triggered a dose-dependent IL-23 response ( FIG. 12B ). These results illustrate that gliadin directly stimulates monocytes to secrete IL-23 and related inflammatory mediators and further support a primary role for the IL-1 system in IL-23 mediated inflammation.
[0104] In summary, our studies demonstrate that enzymatically digested wheat gliadin stimulates monocytes to produce significantly more IL-23, IL-1β and TNFα in CD patients than HLA-DQ2 + healthy individuals, and reveal a fundamental role for the IL-1 system in the IL-23 pathway. We show that IL-1β directly induces monocytes to secrete IL-23, while its natural inhibitor, IL-1ra, substantially inhibits both the IL-1β and IL-23 responses generated by monocytes exposed to gliadin. Moreover, our data indicate that gliadin initiates the inflammatory cascade by disrupting the balance between these two IL-1 members, which could be targeted therapeutically for treatment of this disease and other conditions associated with IL-23 mediated inflammation.
Methods
[0105] Cells. Peripheral blood mononuclear cells (PBMC) were isolated from Celiac patients' and healthy donors' whole blood by methods common in the art including, for example, by density gradient centrifugation in Lymphocyte Separation Medium (ICN Biomedicals Inc.). PBMC were viably cryopreserved in RPMI-1640 media (Invitrogen Corp.) containing 20% human AB serum (hAB) (Gemini Bioproducts) and 10% Dimethylsulfoxide (Sigma) using an automated cell freezer (Gordinier Electronics), and stored in the vapor phase of liquid nitrogen until used. Highly purified monocytes (95% purity) were obtained from healthy donors as above followed by countercurrent centrifugal elutriation. The resulting cells were viably cryopreserved in fetal bovine serum (Summit Biotechnology) containing 10% DMSO and 5% glucose (Sigma) for later use. All individuals gave informed consent for peripheral blood drawn for this study. The study protocol was approved by the Institutional Review Board at the University of Maryland School of Medicine.
[0106] DNA Extraction and HLA Typing. DNA was extracted using common methods and reagents, for example from a portion of the PBMC using the QIAamp DNA Mini Kit (Qiagen) per the manufacturer's instructions. DNA was analyzed by spectrophotometry to determine quantity and purity and stored at −20° C. until used. Alleles of genes encoding HLA were identified using One Lambda Micro SSP™ ABDR Typing Kit, and alleles of genes encoding HLA-DQ were determined by DQA1 and DQB1 SSP UniTray® Kit (Dynal Biotech) following the manufacturer's.
[0107] Reagents. Gliadin was prepared by enzymatic digestion as described previously (Thomas et al., J. Immunol., 176:2512-2521 (2006)). The presence of contaminating endotoxin in gliadin was determined by Limulus amebocyte assay per the manufacturers' instructions. 100 mg of β-D-glucan from barley (Sigma) was dissolved in 600 ul 95% EtOH followed by 9 mL distilled water. The resultant slurry was stirred vigorously at 100° C. for 3 minutes, allowed to cool, and stored at 10 mg/ml at 4° C. until used. 25 overlapping 20 mers spanning the sequence of α-gliadin were synthesized and purified >95% at the University of Maryland Biopolymer Lab, and stored at −20° C. until used. Recombinant human IL-1β and IL-1ra were purchased from R & D Systems.
[0108] PBMC cultures. PBMC from CD patients and HLA-DQ2 + healthy controls was tested as follows. 10 6 PBMC/ml were incubated in RPMI-1640 supplemented with 10% heat inactivated hAB, 1% L-glutamine, 1% Pen-Strep and 20 mM Hepes Buffer (cRPMI) with and without PTG, β-glucan, 5 ng/ml rhIL-1β, or 10 μg/ml pooled synthetic 20 mers of α-gliadin in 96 well U-bottom plates (Denville Scientific Inc.) at 37° C. in 5% CO 2 for 6, 24, 48, or 72 h. Alternatively, 10 6 PBMC/ml were incubated with 0.5 μg/ml rhIL-1ra at 37° C. in 5% CO 2 for 1 h then cultured with and without 100 μg/ml PTG or 500 μg/ml β-glucan for an additional 20 h. Cell-free culture supernatants were harvested for cytokine and chemokine analysis.
[0109] Elutriated monocyte cultures. 5×10 5 monocytes/ml were cultured in cRPMI with and without 100 μg/ml PTG, 100 μg/ml β-glucan, or 0.5-50 ng/ml rhIL-1β in 96 well U-bottom plates at 37° C. in 5% CO 2 for 20 h. Alternatively, 5×10 5 monocytes/ml were incubated with 0.5 μg/ml rhIL-1ra at 37° C. in 5% CO 2 for 1 h then cultured with and without 100 μg/ml PTG or β-glucan for an additional 20 h. Cell-free culture supernatants were harvested for cytokine and chemokine analysis.
[0110] Cytokine & chemokine analysis. Cell-free culture supernatants were analyzed for IL-1β, IL-1ra, IL-6, IL-12p70, IFNγ, TNFα (Bio-Plex Cytokine Assay kit, Bio-Rad) or IL-1β, IL-23 (ELISA kit, eBiosciences), IL-1ra and CCL20 (Quantikine ELISA kit, R & D Systems) following the manufacturers' protocols. Appropriate standard curves were included in each assay.
[0111] Statistical analyses. Data are presented as mean values+s.d. P values comparing different conditions within the same individuals were calculated using paired two-tailed Student's t tests and p values comparing the two study groups were determined by unpaired two-tailed Student's t tests ( FIG. 1A ). P values<0.05 were considered statistically significant.
[0112] Certain patents and printed publications have been referred to in the present disclosure, the teachings of which are hereby each incorporated in their respective entireties by reference.
[0113] While the invention has been described in detail and with reference to specific objects, examples or embodiments thereof, it will be apparent to one of ordinary skill in the art that various changes and modifications can be made thereto without departing from the spirit and scope of the invention.
|
Autoimmune diseases are the consequence of complex interactions between a mosaic of host genetic factors and etiologic elements. Celiac disease (CD) is an autoimmune disease prevalent in 1% of the general population, but is unique on two accounts; a) the majority (90%) of individuals with CD have the HLA class II DQ2 allele, the others HLA-DQ8 and b) the etiologic agent is gluten proteins from wheat and related prolamins in barley and rye. The disease process is generally considered to be mediated by T cells that recognize HLA-DQ2 specific peptide sequences in gluten. There is currently no therapeutic treatment for CD. To this end, the inventors have identified a novel therapeutic target for CD and innate immune pathways in other inflammatory conditions.
| 0
|
FIELD OF THE INVENTION
[0001] The present invention relates to methods for protecting operating inert anode electrodes from temperature drops upon removal and replacement of an adjacent anode. More specifically, the present invention relates to protection of inert anodes and their support structure from thermal shock when operating in a cryolite bath during adjacent anode change out operations.
BACKGROUND OF THE INVENTION
[0002] Aluminum is produced conventionally by the electrolysis of alumina dissolved in a cryolite-based molten electrolyte bath at temperatures between about 900° C. and 1000° C.; the process is known as the Hall-Heroult process. A Hall-Heroult reduction cell typically comprises a steel shell having an insulating lining of refractory material, which in turn has a lining of carbon that contact the molten constituents. Conductor bars connected to the negative pole of a direct current source are embedded in the carbon cathode substrate that forms the cell bottom floor. The anodes are at least partially submerged in the cryolite bath.
[0003] Electrolytic reduction cells must be heated from room temperature to approximately the desired operating temperature before the production of metal can be initiated. Heating is done gradually and evenly to avoid thermal shock, which can in turn cause breakage or spalling. The heating operation minimizes thermal shock to the lining, the electrodes and the support structure assemblies upon introduction of the electrolyte and molten metal to the cell. Once at operating temperatures carbon anodes erode and have to be replaced usually one at a time, in what is called a “change out” operation. D'Astolfo Jr. et al. in U.S. Pat. No. 6,551,489B2 addressed change out operations where an inert anode assembly containing from about four to eleven inert anodes on a common conducting support was used to replace standard single, large carbon anodes. The inert anodes were about from 12 cm to 76 cm. in diameter and from about 12 cm. to 38 cm. high.
[0004] Carbon anodes can be placed in to the electrolyte cold and heated by the energy of the cell to operating temperatures, at which time the nominal current of the anode will be attained. Ceramic anodes have much longer lives but are more prone to thermal shock and therefore need to be preheated in a furnace outside of the electrolytic cell prior to insertion into the hot electrolyte. During transfer, the cooling or heating of the anodes must be also minimized to avoid thermal shock. The thermal shock/cracking was thought to only occur both during movement of the anodes into position and during their placement into the molten salt. Thermal shock relates to the thermal gradient (positive or negative) through the anode that occurs, usually during the movement from the preheat furnace to the cell, and also upon insertion of the anodes into the molten salt. Depending upon the time frame, a thermal gradient as low as between about 20° C. to 50° C. can cause cracking.
[0005] In an attempt to protect electrodes in an electrolysis cell from thermal shock during start-up, U.S. Pat. No. 4,265,717 (Wiltzius), taught protection of hollow cylindrical TiB 2 cathodes by inserting aluminum alloy plugs into the cathode cavity and further protecting the cathode with a heat dispersing metal jacket having an inside heat insulating layer contacting the TiB 2 , made of expanded, fibrous kaolin-china clay (Al 2 O 3 .2SiO 2 .2H 2 O), which would subsequently dissolve in the molten electrolyte. In U.S. Pat. No. 6,447,667 B1 (Bates et al.) the inert anode was coated with carbon and/or aluminum as protection against the cryolite bath. Also, in U.S. patent application Publication No. 2003/0127339A1 (LaCamera et al.) anodes were first heated and had an insulating boot attached during submersion into the molten bath. A silica or alumina insulating material was found to be effective. However, such silica or alumina boots were made to dissolve in the bath over time, so that at change out they would usually be non-existent.
[0006] Aluminum electrolysis cells have historically employed carbon anodes on a commercial scale. The energy and cost efficiency of aluminum smelting can be significantly reduced with the use of inert, non-consumable, and dimensionally stable anodes. Use of inert anodes rather than traditional carbon anodes allows a highly productive cell design to be utilized, thereby reducing capital costs. Significant environmental benefits are also realized because inert anodes produce essentially no CO 2 or CF 4 emissions. Some examples of inert anode compositions are provided, for example, in U.S. Pat. Nos. 4,374,761; 5,279,715; and 6,126,799 assigned to Alcoa Inc.
[0007] It has recently been found, that, in inert anodes cells, when an anode is replaced by taking it out of an operating bath, at about 960° C., its function as a “heat sink” and radiation shield is lost and the surface temperature of exposed adjacent inert anodes still operating in the molten bath can drop more than 25° C. during the first minute. This could cause adjacent inert anodes to crack and fail in the first 20 seconds. This problem has created a critical need to protect the anodes remaining in the molten bath from temperature drops during change out. It is therefore a main object of this invention to provide some means to protect inert anodes from such temperature drops.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to methods for protecting ceramic or cermet inert anodes from thermal shock during operation in an electrolysis cell, when an adjacent anode is replaced by removing the adjacent anode from the cell. The method generally comprises (1) operating an electrolysis cell having a plurality of inert anode assemblies at over 850° C. in a molten cryolite bath, where all of the anode assemblies are shielded by a circumscribed heat radiation shield, (2) withdrawing a shielded anode assembly adjacent to other shielded anode assemblies thus exposing the other shielded assemblies to lower ambient temperatures, and (3) inserting a new shielded anode assembly adjacent the other shielded anode assemblies, wherein the radiation shield does not disintegrate in contact with cryolite fumes, remains intact and in place above the molten bath, and prevents a temperature drop within its circumscribed assembly of under about 30° C. Preferably the shield prevents a temperature drop of under about 20° C. The heat radiation shield is in place during submersion of the anode into the molten bath and during its operation in the cell. The bath preferably comprises cryolite. Because the inert anodes can be rapidly cracked at short temperature gradients during operation of the cell, the effect of temperature gradients must be minimized. The change to a new shielded assembly is preferably accomplished in less than 60 seconds, most preferably 10 seconds to 50 seconds.
[0009] Similarly, the castable box or plate which is positioned just above the anodes are also subject to thermal shock. The plates, typically made of a refractory material such as a silica or alumina ceramic, can also crack as a result of thermal gradients. Accordingly, the present invention is further directed to an optional method for protecting castable plates from thermal shock by extending the heat radiation shield to the plates.
[0010] The present invention further provides a method of replacing anode assemblies which are immersed in a bath comprising molten electrolyte in an aluminum electrolysis cell comprising: (1) operating an aluminum electrolysis cell at a temperature over about 850° C., where a plurality of adjacent anode assemblies are immersed in molten electrolyte, said assemblies being subject to deterioration by at least the electrolyte and also operating as a heat sink and radiation shield while in the molten electrolyte, where all of the anode assembly comprises an inert shielded anode having an attached, heat radiation shield; (2) removing at least one anode assembly adjacent another shielded assembly by drawing it out of the molten electrolyte, thus exposing the remaining adjacent shielded assemblies to lower external ambient temperatures, wherein the heat radiation shield reduces radiative cooling of the shielded inert anode assembly over about 30° C.; and (3) replacing the removed anode assembly with another anode assembly, wherein the heat radiation shield remains intact and in place above the molten electrolyte bath. In order to assist the function of the heat radiation shield, the anode removal and replacement process should be completed in less than about 3 minutes. The heat radiation shields are from about 0.2 cm to about 4.0 cm thick and preferably are made of ceramic selected from at least one of alumina or silica. Unlike the previous protective boots previously described as taught in U.S. patent application Publication No. 2003/0127339A1 by LaCamera et al., these heat radiation shields are designed with materials that are capable of surviving in severe environments that exist just above the bath. In addition to surviving, they must also provide the thermal protection required to prevent anode thermal shock. Preferred materials include alumina and at least one of silica and calcia, which is meant to herein include materials such as, high alumina materials, aluminates including alumina silicates, calcium aluminates and calcium alumina silicates. Preferably, they consist essentially of those materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic illustration, partly in section, showing replacement of an anode assembly 16 ′ in an electrolysis cell for making aluminum utilizing a molten electrolyte, with a still immersed adjacent anode assembly 16 , both having an attached heat radiation shield; and
[0012] FIG. 2 is a graph of temperature drop of the anode vs. time, for anodes with radiation shields (Group 1 ) and without radiation shields (Group 2 ), as determined from both thermal measurements and simulations of anode assembly charge out processes.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] The present invention is directed to a method for protecting an inert anodes from thermal shock. Preferably, the inert anode is made of a cermet or ceramic material. The present invention is further directed to a method for protecting a castable support for the anode from thermal shock.
[0014] Referring now to FIG. 1 , one type of operating electrolytic cell 10 for producing metal, such as aluminum is shown, and can include a carbon cathode floor 11 and sidewalls 12 , 13 extending upwardly from the floor 11 . The cell 10 will initially be described as the in place anode assembly 16 , shown as the left assembly in FIG. 1 . The sidewalls 12 , 13 can be both covered by a solid crust 14 . The floor 11 and sidewalls 12 , 13 define a chamber above the molten cryolite bath 15 and aluminum deposit 17 . A steel shell 18 supports the floor 11 and sidewalls 12 , 13 . A metal collector bar 19 carries current from the carbon cathode floor 11 . The cell 10 includes several anodes 20 fastened by electrically conductive metal conductors 22 which can pass through a protective ceramic cover 28 and a layer of insulation 30 . The conductors 22 are attached to a metallic distribution plate 32 . The distribution plate is supported by a support beam 26 which can be used to raise or lower the anode assembly 16 . The conductors 22 , distribution plate 32 , and support beam 26 together make up a support structure assembly for the anodes 20 and anode assembly 16 . The ceramic cover 28 and insulation layer provide environmental and thermal protection.
[0015] The conductors 22 are made of any suitable material providing electrical conductivity to the anodes 20 . The insulating layer 30 preferably includes one or more thermal insulating layers of any suitable composition. The protective cover 28 is made from a highly corrosion resistant ceramic material capable of being exposed to the severe environment above the molten bath 15 . An electrically conductive metallic distribution plate 32 provides a current path between the support beam 26 and the conductors 22 .
[0016] The inert anodes 20 are protected from thermal shock during removal of an adjacent anode assembly 16 ′ by heat radiation shields 24 . The radiation shields preferably can be disposed a distance 25 above the bottom of the inert anode 20 as shown. The shields circumscribe at least two sides of the assembly and preferably, while not shown, surround the assembly and inert anodes 20 on all four sides. The distance 25 can range from 12 cm to 20 cm. The ambient atmosphere 40 , is substantially cooler than the molten cryolite 15 by at least 800° C. As the anode assembly 16 ′ is removed, a major heat sink and radiation shield is lost and adjacent inert anodes are exposed to the ambient atmosphere 40 which can cause cooling of over 20° C. A change about 20° C. to 30° C. can provide sufficient thermal stress to initiate cracking of ceramic or cermet inert anodes.
[0017] FIG. 2 illustrates a simulation of the change in anode surface temperature over time during change out, where series of curves shown as Group 2 , show surface temperature changes without a radiation shield in ° C. vs. Group 1 with a radiation shield in ° C. As can be seen, Group 1 which includes shields made of a high alumina material having a thickness of 0.30 cm provided sufficient radiation protection from the ambient temperatures to limit the temperature change to about 20° C. to 30° C. Because the radiation shields must remain intact above the bath in order to protect the anodes from thermal shock, they must not dissolve in molten cryolite fumes.
[0018] The requirements for non-dissolvable, effective radiation shields which surround/circumscribe an anode assembly or plate to which the anode is attached in terms of ratio of shield compositions, porosity, thickness, thermal shock and the like are now described in detail. An effective radiation shield material must be resistant to chemical attack from fluoride fumes and occasional splashing of cryolite bath. It must also be able to withstand thermal shock encountered during anode insertion and movements of adjacent anodes. Simple or compound oxides of alumina with silica and calcia have been found to be both chemically and thermal shock resistant. Alumina content should be from 50 wt % to 95 wt % or more preferably 60 wt % to 85 wt %. Porosity must be low enough to afford good mechanical strength, but not so low as to negatively impact thermal shock resistance. Porosity should be in the range of 5 vol % to 30 vol %, or more preferably 10 vol %-25 vol %.
[0019] Thickness requirements are determined by strength and practical fabrication limitations. The minimum practical thickness which satisfies mechanical integrity and ease of fabrication should be used that is and from 0.3 cm to 4.0 cm is preferably in the range of 1.27 cm to 3.7 cm or more preferably 1.9 cm to 3.18.
[0020] Having described the presently preferred embodiments, it is to be understood that the invention may be otherwise embodied within the scope of the appended claims.
|
A method of protecting an inert anode assembly ( 16 ) operating in an electrolysis cell ( 10 ) for producing metal when an adjacent assembly ( 16 ′) is removed exposing remaining assemblies to low ambient temperatures ( 40 ) by utilizing heat radiation shields ( 24 ) which can circumscribe every inert anode assembly ( 16 ), where the shields ( 24 ) remain intact and in place in the cell ( 10 ) while operating in molten electrolyte ( 15 ) at about 850° C.
| 2
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a composite article comprising a copper element, e.g. a copper printed circuit and an adhesive material, and a process for producing such an article. The invention is particularly, but not exclusively, applicable to a multi-layered wiring circuit board and also is applicable to other articles in which copper is bonded to an adhesive material such as semiconductor chip packages, flexible printed circuits and a tape automated bonding device.
2. Description of Prior Art
In FIG. 1 described in detail below there is shown a conventional multi-layer wiring circuit board. In the manufacture of such a board, individual circuit boards carrying copper wiring layers are laminated in a stack alternately with layers of adhesive material known as prepregs which are cloth layers impregnated with thermosetting polymers. To achieve bonding, the stack is subjected to pressure and heat. The present specification is especially concerned with the bonding between the copper layer and the adhesive material.
U.S. Pat. No. 4,642,161 (JP-A-86-176192) describes a process in which a conventional multi-layer printed wiring board is produced by roughening the surface of a copper circuit layer by an etching treatment, carrying out a "blackening treatment" to form a copper oxide film by oxidation, effecting reduction of the copper oxide and thereafter carrying out lamination and bonding with prepreg layers. In this case, the surface of the copper foil has pit-like recesses having a diameter and depth of from 0.1 to 1.0 μm, due to etching.
U.S. Pat. No. 4,643,793 (JP-A-86-15981) discloses a method of treating a surface for copper to improve its adhesion to prepreg material. The surface is electrolessly plated by contacting it with an aqueous solution containing (a) copper ions, a chelating agent, a reducing agent, hydroxy ions and water, and (b) a nitrogen-containing heterocyclic compound which colors the surface into a color and gloss other than that of metallic copper. Thereafter the surface is treated with at least one of ammonia water, an aqueous solution of a reducing agent and an acidic solution. It is stated that the treatment by the first solution can form a copper deposition layer having minute particles, needles or cylinders or mixtures thereof. Etching to roughen the surface prior to the electroless printing is described.
U.S. Pat. No. 3,615,737 discloses an electroless metal deposition solution containing a small amount of extraneous ions such as ions of vanadium, antimony, arsenic and bismuth. It is stated that the solution provides enhanced ductility of electroless metal deposits.
U.S. Pat. No. 4,632,852 (JP-A-86-9578 and JP-A-86-38406) discloses a process for electroless copper plating suitable for thick plating in the production of printed circuit boards. Inorganic germanium compounds or silicon compounds are added to the plating solution, and plating is carried out while injecting an oxygen-containing gas into the solution and/or with an oxidizing agent in the solution. It is said that an improvement of the mechanical properties of the plating film are achieved.
JP-A-77-79271 discloses a process for manufacturing a multi-layer printed circuit board, which comprises roughening the surface of desired circuit patterns by plating a patterned copper film by electroless metal deposition and laminating a plurality of the treated printed circuit boards. The adhesion strength between the treated circuit boards can be improved.
The conventional techniques for producing multi-layer wiring circuit boards can obtain sufficiently high bonding strength between a copper circuit and a prepreg resin in the case where known resins such as an epoxy resin, a polyimide resin, and the like are used and can secure high reliability of the printed wiring board.
However, there is a need to improve bonding of the copper to the adhesive. Novel resins exist whose properties such as heat resistance, thermal expansion coefficient and the like are improved permitting high density wiring and high computation speed of the printed circuit but these have low affinity with respect to copper and known techniques cannot obtain sufficiently high bonding strength. Accordingly, sufficient reliability cannot be obtained in the multi-layer printed wiring board.
Secondly, the conventional techniques make the copper surface coarse by etching, but if the etching conditions are not appropriate the circuit is excesively etched locally and the connection reliability of the wiring tends to be reduced.
SUMMARY OF THE INVENTION
One object of the present invention is to provide an article containing copper bonded to an adhesive material, such as a multi-layered printed wiring board, with increased adhesion strength between the copper and the adhesive material.
It is a further object of embodiments of the present invention to provide a process for making such an article in which decrease of the connection reliability of the circuits due to etching is avoided.
Broadly, the present invention in one aspect provides a composite article comprising a copper element and an adhesive material adhesively bonded to a surface of said copper element, wherein the surface of the copper element has knife-shaped elongate projections. The opposite flanks of these projections are at an average angle of less than 60° to each other. The projections extend along the copper surface. This microstructure anchors the copper element to the adhesive.
In another aspect, the invention provides a method of forming the above composite article, with the microstructure of the copper surface as described.
The invention further broadly provides a process of making a composite article having a copper element bonded to an adhesive material, comprising the steps of;
(a) electrolessly plating a surface of the copper element to form thereon a plated copper layer,
(b) oxidizing the plated copper layer,
(c) causing the adhesive material to adhere to the oxidized plated copper layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective sectional view of a conventional multi-layer wiring circuit board to which the invention may be applied;
FIG. 2 is an enlarged sectional view of the part II of FIG. 1, illustrating the present invention;
FIG. 3 is a diagrammatic enlarged perspective view of the part III of FIG. 2;
FIG. 4 is a scanning electron microphotograph of the projections formed on a circuit pattern in one Example according to the invention; and
FIG. 5 is a scanning electron microphotograph of the projections on a circuit pattern in the same Example at a later stage.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention will now be further described and illustrated, and preferred embodiments given, with reference to the above drawings.
Since bonding strength between a copper foil and an adhesive depends greatly on the mechanical anchor effect of the interface, the shape of the coarsened copper surface affects greatly the bonding strength.
The present inventors have found that the coarse surface formed by conventional etching has hemi-spherical recesses of at most about 1 μm in diameter. Even if the etching time is extended, etching proceeds on the entire surface so that it is not easy to attain a high degree of roughening of the surface. Since the roughened surface has recesses approximating hemi-spheres, the effect of the mechanical engagement to the resin is not sufficient. To improve bonding strength by mechanical engagement, the present invention involves formation of projections on the copper surface rather than forming recesses by etching, and the irregularly arranged knife-like projections of the invention are more effective in shape than projections of other shapes such as conical, hemi-spherical, pyramidal and truncated pyramidal. This may be because the contact area is greater between the side surface portions of the elongate projections and the resin, and the peel stress is dispersed. An even better result can be obtained by providing further very small rod-like projections on the knife-shaped projections.
Thus, due to the knife-shaped projection provided on the surface of the circuit layer of copper, the mechanical anchor effect at the interface between copper and the resin can be improved and a printed wiring board with high reliability can be obtained even when a resin having a relatively low affinity with copper is used. Since etching can be omitted, the risk of over-etching a circuit portion can be avoided. Also the profile of the copper wiring element is preserved.
The knife-like projections described above are not obtained by the conventional etching method but can be obtained by depositing copper to the desired shape on the copper circuit surface by plating. It is preferred to use electroless copper plating as the plating method, because a circuit pattern may have independent portions not connected electrically to the exterior. Such portions cannot be electrolytically plated.
The plating conditions and composition must be chosen to achieve the desired surface microstructure.
If the mechanical strength and flexibility of the copper projections are not sufficient, the projections may be broken. Therefore, the composition of the plating solution should be appropriately selected with this in mind also.
Although the electroless copper plating solution disclosed in JP-C-1,085,648, for example, produces electroless copper plating with excellent properties, the shape of the plated surface is pyramidal or truncated pyramidal, and such a surface does not exhibit sufficient bonding strength to the adhesive layer material such as an epoxy resin impregnated prepreg.
As mentioned, the possibility of loss of connection reliability due to local excess etching can be eliminated by forming the projections through plating without carrying out a surface roughening treatment by etching involving removal of material from the surface. Such an effect can be obtained for those resins, such as an epoxy resin, a polyimide resin and the like, whose bonding strength has never been a problem, and when the present invention is applied using these resins, bonding strength between copper layers and the resins can be improved when compared with the prior art technique, and very high reliability can be achieved. Within the invention, light etching to clean and de-fat the copper surface can be employed, prior to the formation of the projections. This does not involve the risk of connection loss.
In some processes within the invention, heavier etching may be used.
To obtain high bonding strength it is preferred to form further fine rod-like projections on the surface of the knife-shaped projections after they are formed on the copper surface. Methods of forming a copper oxide coating film such as a so-called "blackening treatment" and "brown oxide treatment" can be employed as the method of forming such fine projections. The fine projections may alternatively be formed by plating treatment which provides fine surface roughness equivalent to the blackening treatment and brown oxide treatment. Where acid resistance is required for the bonded interface, acid resistance can be improved by reducing the copper oxide coating film to metallic copper by use of a reducing agent. In this case, an amine-borane reducing agent can be suitably used.
Nickel plating, to provide a thin film of nickel on the copper, may be performed after the electroless plating to form the knife-shaped projections or after the oxidation to form the rod-shaped projections.
The height of the knife-shaped projections is preferably at least 0.1 μm. There is no upper limit to the plating thickness to produce these projections. The greater the plating thickness, the higher the knife-like projections grow and the higher the bonding strength becomes. The upper limit is rather limited by the dimension of the pattern. In particular, the upper limit of the plating thickness is generally from 5 to 10 μm, for a fine copper pattern width of up to 100 μm. A preferred range for the height of the knife-shaped projections is 1 to 10 μm, more preferably 1 to 3 μm.
When the small rod-shaped projections are formed on the knife-shaped projections, the height of the latter is preferably at least five times, more preferably at least 10 times, the average height of the former. Suitably, the rod-shaped projections, which are elongate, with length greater than width, have an average diameter of 1-50 nm and an average length of 10-200 nm. Preferred average diameter is in the range 5-10 nm and average length in the range 30-100 nm. A round cross-sectional shape is preferred, and the projections may taper.
In the present invention, the adhesive material is typically made of prepreg resins, adhesive sheets or films, adhesive varnishes or adhesive resin pastes.
To form the knife-shaped projections, it is preferred in the invention to use an electroless copper plating solution containing at least one compound of Si, Ge and V or carbonic acid ions.
If a polyalkylene oxide or polyalkylether is added to the plating solution described above, larger knife-shaped projections can be formed in the same plating thickness.
Preferably the electroless copper plating solution used for forming these projections on the copper layer, e.g. circuit patterns, contains one of oxoacid ions of silicon in an amount of 25 to 150 mg/l calculated as Si; oxoacid ions of germanium in an amount of 20 to 100 mg/l calculated as Ge; oxoacid ions of vanadium in an amount of 0.2 to 10 mg/l calculated as V; and oxoacid ions of carbon in an amount of 0.05 to 1.5 mol/l calculated as CO 3 =.
Examples of compounds added to a plating solution to provide such oxoacid ions are:
Si: sodium metasilicate, sodium orthosilicate, sodium silicate and water glass.
Ge: germanium dioxide, sodium germanic acid, germanium dichloride and germanium nitrate.
V: sodium metavanadate, sodium orthovanadate and vanadium pentoxide.
CO 3 =: sodium carbonate, sodium percarbonate and carbon dioxide gas.
Apart from the above additives, the preferred electroless copper plating solutions used for forming the knife-shaped projections are known electroless copper plating solutions which typically contain a water soluble copper salt at a concentration of 50 g/l or less, a reducing agent such as formaldehyde at a concentration of 2 to 10 ml/l, and a chelating agent such as ethylenediamine tetraacetic acid (EDTA) in at least a stoichiometric amount with respect to copper ions, the pH value of the solution being regulated to 11 to 13.
These preferred plating solutions used in the present invention have high selectivity, i.e. they plate selectively on copper, with low tendency to plate on the insulating material. There is therefore a low risk of "bridging" i.e. formation of an unwanted interconnection between wiring parts.
Examples of processes within the invention for forming multi-layered wiring circuit boards are as follows:
(1) Forming circuit patterns on substrate boards--optionally, etching the surfaces of the circuit patterns to roughen them--electroless plating to form knife-shaped projections on the roughened patterns--optionally, nickel plating on the projections--lamination.
(2) Forming circuit patterns on substrate boards--optionally, etching the surfaces of the circuit patterns to roughen them--electroless plating to form knife-shaped projections--oxidizing the surfaces of the knife-shaped projections to provide rod-shaped projections--lamination.
(3) Forming circuit patterns on substrate boards-- optionally, etching the surfaces of the circuit patterns--electroless plating to form knife-shaped projections--oxidizing the surfaces of the knife-shaped projections to form rod-shaped projections--reducing treatment of the oxidized surfaces of the knife-like projections--plating the projections with nickel--lamination.
Referring now to the drawings, FIG. 1 is a perspective sectional view of a typical conventional multi-layered printed wiring circuit board, made up of a plurality of double-sided circuit boards 2,2',10 laminated together by prepreg layers 6. Outer layer circuits 4,4' are formed on the outer circuit boards 2,2' and inner circuit patterns 12 on the inner faces of the outer boards 2,2' and the inner boards 10 are bonded to the prepreg layers 6. Copper-lined through-holes 8 provide interconnections between the layers.
Typically the width of the copper wiring elements in the circuits adhered to the adhesive layer is in the range 50 μm to 3 mm, and their thickness is in the range 30 to 50 μm.
FIG. 2 is an enlarged sectional view of part II of FIG. 1 in an embodiment of the invention. The circuit wiring element 12 is formed on the inner face of outer circuit board 2'. On the wiring element 12 is a layer 14 of electrolessly plated copper having at its outer face knife-like projections. On the knife-like projections is a fine microstructure consisting of rod-shaped projections 16 obtained by reducing an oxide film.
FIG. 3 is a further enlarged diagrammatic view of the portion III of FIG. 2, showing the nature of the knife-shaped projections on the layer 14. Here the smaller rod-shaped projections are omitted. The angle θ between the flanks of each knife-shaped projection is less than 60°. These projections are shown in FIG. 3 as having pointed apexes, but in practice their apexes are more rounded. They extend elongately along the surface of the layer 14 and intersect each other in a random manner. This can be seen especially well in FIG. 4, described more below.
Non-limitative examples of the invention will now be given.
EXAMPLE 1
Copper of a copper-plated laminated sheet for an inner circuit layer was etched using an etching resist as a mask to form a copper circuit having a predetermined pattern. Next, electroless copper plating was applied to this surface to a thickness of 5 μm using an electroless copper plating aqueous solution having the composition given below and a surface having knife-shaped projections was obtained in which the projections were from 0.1 to 5 μm wide, 5 to 7 μm long and 1.8 μm high and were arranged irregularly as shown in FIGS. 2 to 4.
______________________________________Plating solution______________________________________EDTA.2Na.2H.sub.2 O 30 g/lCuSO.sub.4.5H.sub.2 O 10 g/lGeO.sub.2 70 mg/lPEG 1000(MW)* 1 g/l37% formalin 2.5 ml/lpH 12.7temperature 72° C.______________________________________ (*polyethylene glycol, average molecular weight 1000)
Next, the substrate was dipped into a solution containing 30 g/l of NaClO 2 ,10 g/l of NaOH and 5 g/l of Na 3 PO 4 .12 H 2 O at 75° C. for 2 minutes to form a copper oxide film on the surface (blackening). The substrate was then dipped into a solution of dimethylamino borane (6 g/l) and NaOH (5 g/l) for one minute to reduce the copper oxide film to metallic copper. This formed rod-shaped projections on the knife-shaped projections. Thereafter, a predetermined number of such substrates were laminated and hot-pressed at 3 MPa and 220° C. for 2 hours to form a multi-layer structure by bonding through prepregs each obtained by imprenating cloth with a resin having the composition below and drying the cloth:
______________________________________cresol novolak epoxy-modified polybutadiene 30 wt %poly (4-vinylbromophenyl) methacrylate 20 wt %2,2-di (4-methacrylethoxy-3,5-dibromo phenyl) 50 wt %propanedicumyl peroxide 0.5 phrbenzoguanamine 2.0 phr(Phr: weight ratio per 100 g resin)______________________________________
A multi-layered printed wiring board was then produced by conventional process steps such as drilling through-holes, through-hole plating, formation of an outer layer pattern, and so forth. Bonding strength between the prepreg resin and the copper foil was 0.8 kgf/cm. Substantially the same bonding strength could be obtained when the amount of GeO 2 in the plating solution was changed within the range of from 30 to 150 mg/l.
FIG. 4 is scanning electron microphotograph showing the structure of the crystals of the knife-shaped projections formed by the process of Example 1 described above after the electroless plating and before oxidation. The average angle θ between the flanks of the projections was about 45°.
COMPARATIVE EXAMPLE 1
A multi-layered printed wiring board was obtained in the same way as in Example 1 except that an etching treatment of the copper pattern 12 was carried out by dipping the substrate into an aqueous solution having the composition given below for 1 minute in place of the electroless copper plating in Example 1:
______________________________________CuCl.sub.2.2H.sub.2 O 50 g/l36% HCl 500 g/ltemperature 40° C.______________________________________
The oxidation and reduction steps of Example 1 were included.
Semi-spherical recesses having a diameter of 0.7 to 1 μm were present on the copper surface after the etching treatment. Bonding strength between the prepreg resin and copper was 0.2 kgf/cm. It was found that an average angle at peaks of the smooth projections left in the copper surface was about 120°.
EXAMPLE 2
A multi-layered printing board was obtained in the same way as in Example 1 except that 1 g/l of Na 2 SiO 3 .9H 2 O was used in place of 70 mg/l of GeO 2 in the electroless copper plating solution used in Example 1. Knife-shaped projections 0.8 to 2 μm long and 0.5 μm high were present on the surface after plating, and the bonding strength with the resin was 0.7 kgf/cm. The microstructure of the copper surface of the wiring was the same as in Example 1.
EXAMPLE 3
In place of 70 mg/l of GeO 2 in the plating solution of Example 1, 1.5 mg/l of NaVO 3 was used. The process was otherwise identical to that of Example 1. The plating time was 2 hours. Knife-like projections 0.8 to 2 μm wide, 5 to 6 μm long and 1.3 μm high were formed on the surface of the copper and the bonding strength to the resin was 0.65 kgf/cm.
EXAMPLE 4
A multi-layered printed board was obtained in the same way as in Example 1 except that an electroless plating solution having the composition shown below was used in place of the plating solution of Example 1:
______________________________________EDTA.2Na.2H.sub.2 O 30 g/lCuSO.sub.4.5H.sub.2 O 14 g/lNa.sub.2 CO.sub.3 30 g/lPEG 600 (Average mol. wt.) 10 ml/l37% formalin 8 ml/lpH 11.8temperature 72° C.______________________________________
Knife-shaped projections 0.1 to 0.3 μm wide, 10 to 15 μm long and 0.6 μm high were formed on the copper surface, and the bonding strength to the resin was 0.85 kgf/cm.
The microstructure produced was as in Example 1.
EXAMPLE 5
A multi-layered printed board was obtained in the same way as in Example 1 except that PEG 1000 was removed from the composition used in Example 1. Bonding strength was 0.5 kgf/cm. The microstructure was generally similar.
COMPARATIVE EXAMPLE 2
In the procedure of Example 1 (including the oxidation/reduction treatment), electroless copper plating was conducted including 30 mg/l of 2,2'-dipyridyl in place of 70 mg/l of GeO 2 in the copper plating solution of Example 1. The copper surface after plating had the form of a pyramid or truncated pyramid having a side length of 0.5 to 1 μm. Bonding strength between the copper and the resin was 0.1 kgf.cm.
HEAT RESISTANCE TEST
A heat resistance test was conducted by floating the multi-layer printed wiring board produced by the method of Example 1 in molten solder at 260° C. or 288° C. A section of the inner layer circuit portion of the printed boards used as the testpiece was observed through a microscope to examine (1) peeling-off between the inner layer circuit and the resin and (2) cracks of the resin. The result is tabulated in Table 1 below (see Example 6).
It was found after the heat resistance test that cracking of the adhesive resin and peeling between the adhesive resin and the copper patterns did not occur.
EXAMPLE 6
Copper plating was applied to a thickness of 5 μm to the entire surface of a copper foil of a copper laminate sheet intended for an inner wiring layer using a plating solution having the composition set out below. Next, the circuit portion was masked by use of a dry film photoresist and a circuit pattern was formed by etching. After the photoresist on the circuit was removed, a copper oxide film was formed and the reduction treatment of the oxide film was conducted in the same was as in Example 1. Lamination bonding was conducted in the same way as in Example 1 to obtain a multi-layer printed board. A solder heat resistance test was conducted as described above to observe the peel between the inner layer circuit and the resin and the occurrence of cracks. The result is tabulated in Table 1.
The composition of the electroless copper plating solution is:
______________________________________EDTA 0.08 mol/lcopper sulphate 0.04 mol/lformalin 3 ml/lsodium metasilicate 0.75 g/lPEG 600 20 ml/lpH 12.5temperature 70° C.______________________________________
Since in this example, knife-shaped projections were not present on the side surfaces of the wiring elements of the multi-layer printed wiring board, the peel strength between the copper patterns and the prepreg layers was not so high as in Example 1. Some peeling and cracks occurred at the portion which was subjected to heating in the longer solder resistance tests.
TABLE 1______________________________________Result of Solder Heat Resistance TestTest condition Example Examplesolder temperature float time 1 6(°C.) (s) peel crack peel crack______________________________________260 0 nil nil nil nil 10 nil nil nil nil 30 nil nil yes nil 60 nil nil yes yes288 0 nil nil nil nil 10 nil nil nil nil 30 nil nil yes yes 60 nil nil yes yes______________________________________
In the above experiments, the peel strength was measured in accordance with JIS-C6481 or JIS-C5012.
In accordance with the present invention, a sufficiently high bonding strength can be obtained using conventional adhesive resins which have been used as resins for prepregs and also using novel adhesive resins recently disclosed. It is thus possible to produce a multi-layer wiring board having high reliability.
|
To make a composite article comprising a copper element and an adhesive material adhesively bonded to a surface thereof, the surface of the copper element is provided with knife-shaped elongate projections whose opposite flanks are at an average angle of less than 60° to each other. The knife-shaped elongate projections may include rod-shaped projections much smaller than the knife-shaped projections projecting outwardly from the surface of the knife-shaped projections. The knife-shaped projections may be formed by electroless plating and the rod-shaped projections by oxidation and optionally reduction. Bonding strength is improved.
| 8
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the purchase and sale of bandwidth and, more particularly, to a system and method for real-time buying and selling of bandwidth at differentiated quality of service levels, routing of excess traffic over the bandwidth purchased in real time, and billing and settlement of the transactions.
[0003] 2. Description of the Related Art
[0004] The internet is a collection of large nationwide and international networks. Many of the networks are owned and operated by telephone companies such as MCI, Sprint, ANS, and AGIS. Individual users can be directly connected to one of the networks, or indirectly connected via an internet service provider (ISP), typically a company that provides connectivity to one of the networks for a fee.
[0005] When two end users are directly or indirectly connected to the same network, data is passed between the users over the common network. If the end users are on different networks, the data is passed from one network to the other network at an interconnection point known as a network access point (NAP).
[0006] To provide connectivity to the internet, the ISP must purchase internet protocol (IP) transit, the right to transmit data onto a network at a specified data rate. For example, IP transit is commonly available at 8 Mbps, 16 Mbps, 34 Mbits, 45 Mbps, and 155 Mbps data rates, and varies in price according to the data rate selected. The higher the data rate, the higher the cost.
[0007] The amount of data traffic that an ISP experiences changes dramatically over the course of a day. FIG. 1 shows a graph that illustrates a conventional ISP traffic profile for an ISP that serves business and residential customers, respectively. As shown in FIG. 1 , a traffic profile 100 peaks during the middle of the day due to business users, and again peaks in the evening due to personal users.
[0008] ISPs are keen to deliver the highest quality of internet services to their customers. One approach to doing this is to purchase a level of capacity, such as capacity level 112 , that insures that sufficient capacity is available during the busiest periods. It is not cost effective, however, for an ISP to merely buy capacity to cope with their peak traffic flow.
[0009] As an industry average, ISPs tend to buy 100% more than their average traffic flow. The average traffic flow is defined as the capacity required to cope with the total flow of traffic averaged over a 24-hour period. FIG. 1 shows an average traffic flow level 114 , and a doubled (100% more) traffic flow level 116 .
[0010] As further shown in FIG. 1 , doubled traffic flow level 116 is often insufficient to cope with bursty periods, such as bursty periods 118 , which are times when traffic flows exceed the available capacity. When the amount of data to be transmitted onto the network is greater than the amount of capacity, the data is stored and output in turn as capacity becomes available. This degrades the service by significantly increasing the time required for the data to be delivered to the end user.
[0011] Most ISPs are resigned to this as an inevitable standard trade off between quality of service concerns and IP transit costs. Delays for accessing the internet, however, are becoming critical issues for ISPs as customers become more discerning over their speed of internet access.
[0012] Thus, ISPs buying IP transit capacity are faced with a dilemma when determining the size of their link. If they over-dimension their network, they will have unused capacity, whilst if they under-dimension their network, they will face frequent overloads that result in poor response times for their customers.
[0013] Adding to the dilemma is the approximately 300% to 1000% per year increase in internet traffic. Further, most contracts are for one year, and for blocks of capacity. Thus, ISPs are forced to catch a moving target (the increasing internet traffic) with a wide net (a one year block of capacity).
[0014] As a result, ISPs commonly have expensive, unutilised capacity at the beginning of a contract, and degraded quality of service by the end of the contract. Even with over-dimensioning of their IP transit requirements, ISPs are never sure that they will have enough capacity to provide an adequate quality of service during bursty periods that occur at random.
[0015] Thus, there is a need for a method that provides high quality internet service during bursty periods that costs significantly less than it would to buy a peak capacity level, such as capacity level 112 , and that efficiently responds to increases in demand due to growth.
[0016] There are no real solutions within the market, but some players have attempted to address the problem. One approach is to offer usage-based billing, whereby a charge is levied based upon the volume of IP traffic transferred on the network. Another approach is for ISPs to buy monthly contracts for capacity through an exchange.
[0017] These exchanges allow networks to advertise their price for a monthly transit service. However—if an ISP does buy such a transit service, they are committed to using it for a month regardless of whether they have sufficient traffic to fully utilize the capacity.
SUMMARY OF THE INVENTION
[0018] The present invention provides a system and method for real-time buying and selling of bandwidth at differentiated quality of service levels, routing of excess traffic over the bandwidth purchased in real time, and billing and settlement of the transactions. A system in accordance with the present invention includes a router that routes a plurality of data packets from a number of network users to a number of backbone providers.
[0019] The router has a number of input ports that receive the data packets, a number of output ports that transmit the data packets to the backbone providers, and switching circuitry that connects each input port to each output port. In addition, the router has traffic measuring circuitry that measures traffic levels on the input ports, identifies types of data packets, and outputs traffic information in response thereto. Further, the router has a switch controller that receives traffic information from the traffic measuring circuitry and a number of routing instructions, and controls the switching circuitry in response thereto.
[0020] The system also includes a route optimizer that is connected to the router. The route optimizer receives operating instructions, and generates routing instructions for each input port in response thereto. The routing instructions include a first routing instruction and a second routing instruction. The first routing instruction identifies an output port that is connected to a fixed-capacity bandwidth provider that can receive data packets up to a first traffic level. The second routing instruction indicates that data packets in excess of the first traffic level are to be output to a usage-based bandwidth provider that offers capacity on an as-needed basis.
[0021] The present invention also includes a method for handling overflow traffic for a bandwidth user that has purchased a total fixed amount of bandwidth capacity. The bandwidth user outputs traffic to an input port where the traffic has a traffic level. The method includes the step of monitoring the traffic level on the input port. The method also includes the step of determining if the traffic level is near the total fixed amount of bandwidth capacity. If the traffic level is near the total fixed amount of bandwidth capacity, the method determines if the bandwidth user wishes to reroute its overflow traffic. If the bandwidth user wishes to reroute its overflow traffic, the method determines if the bandwidth user has selected a provider to handle its overflow traffic. If the bandwidth user has not selected a provider to handle its overflow traffic, the method purchases capacity to handle the overflow traffic when the traffic level exceeds the total fixed amount of bandwidth capacity.
[0022] The present invention further includes a method for routing data traffic from a start point to an end destination. A plurality of bandwidth providers are connected to the start point and provide service to the end destination. The method includes the step of continually measuring an amount of time required to send data to the end destination on each of the bandwidth providers that provide service to the end destination. The method also includes the steps of statistically measuring the amount of time to form a measured response time; and assigning each bandwidth provider to one of a range of response times based on the measured response time.
[0023] The present invention additionally includes a method for ranking a list of bandwidth providers that provide service from a start point. The bandwidth providers include backbone providers and bandwidth resellers. The method includes the step of identifying each backbone provider that provides service from the start point to an end destination to form a list of backbone providers for the end destination.
[0024] The method also includes the step of removing backbone providers from the list of backbone providers when the backbone providers indicate that usage-based capacity is not available for sale to form a modified list of backbone providers. The method further includes the step of forming a list of sellers from the modified list of backbone providers. The list is formed by adding bandwidth resellers to the list when the bandwidth resellers have excess capacity on a backbone provider on the list of backbone providers, and by updating the list of sellers which have more or less capacity available due to a sale. The method additionally includes the step of ranking the list of sellers according to a factor.
[0025] A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description and accompanying drawings that set forth an illustrative embodiment in which the principles of the invention are utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a graph illustrating a typical ISP traffic profile 100 for an ISP that serves both business and residential customers.
[0027] FIG. 2 is a block diagram illustrating a system 200 in accordance with the present invention.
[0028] FIG. 3 is a flow chart illustrating a method 300 of determining the best backbone provider in accordance with the present invention.
[0029] FIGS. 4A and 4B are flow charts illustrating methods 400 A and 400 B for determining response times in accordance with the present invention.
[0030] FIG. 5 is a flow diagram illustrating response time measurement in accordance with the present invention.
[0031] FIG. 6 is a flow chart illustrating a method 600 of operating route optimizer 230 in accordance with the present invention.
[0032] FIG. 7 is a graph illustrating a business traffic profile 710 and a residential traffic profile 720 in accordance with the present invention.
DETAILED DESCRIPTION
[0033] FIG. 2 shows a block diagram that illustrates a system 200 in accordance with the present invention. As described in greater detail below, the present invention provides for real-time buying and selling of bandwidth, routing of excess traffic over bandwidth purchased in real time, and billing and settlement of the transactions. In addition, bandwidth can be purchased with different response times so that all traffic can be delivered within a time limit, or types of data can be delivered within different time limits.
[0034] As shown in FIG. 2 , system 200 includes a router 210 that routes incoming data packets from network users, such as internet service providers (ISPs), to network or backbone providers. (Backbone providers are unrelated entities that often have peering arrangements with other backbone providers to provide service to additional destinations.) Router 210 has a number of input ports IP 1 -IPn that receive the incoming data packets from the ISPs, and a number of output ports OP 1 -OPm that transmit the data packets to the backbone providers.
[0035] Router 210 also includes switching circuitry 212 that connects each input port IP to each output port OP, and traffic measuring circuitry 214 that measures the traffic level, and the types of data packets, on the input ports IP 1 -Ipn. Router 210 further includes destination determining circuitry 216 that identifies the destinations that are served by the backbone providers, and congestion monitoring circuitry 218 that monitors the traffic conditions on the backbone providers.
[0036] Router 210 additionally includes a switch controller 220 that controls switching circuitry 212 and, thereby, controls the output ports OP that are connected to the input ports IP. Switch controller 220 receives traffic information from traffic measuring circuitry 214 and a number of routing instructions for each input port IP. The routing instructions include fixed capacity, selected overflow capacity, real-time overflow capacity, and data-type capacity routing instructions.
[0037] Fixed capacity routing instructions relate to fixed blocks of bandwidth that a network user has purchased under a contract. The fixed capacity routing instructions for an input port IP identify the output ports OP that are to receive data packets from the input port IP, and the amount of capacity that can be transmitted to the output ports OP by the input port IP.
[0038] For example, assume that the ISP connected to input port IP 1 purchases a 155 Mbps block of bandwidth from the backbone provider connected to output port OP 2 . In this case, the fixed capacity routing instruction indicates that traffic levels up to 155 Mbps of traffic can be routed from input port IP 1 to output port OP 2 .
[0039] Selected overflow capacity routing instructions relate to usage-based bandwidth that the network user has selected to handle bursts of traffic that exceed the fixed blocks of bandwidth that have been purchased. The selected overflow capacity routing instructions for an input port IP identify the output port OP that is to receive the overflow traffic from the input port IP.
[0040] For example, assume that the ISP connected to input port Ip 1 purchases 155 Mbps of bandwidth from the backbone provider connected to output port OP 2 , and indicates that the backbone provider connected to output port OP 1 is to handle its overflow traffic (traffic in excess of 155 Mbps). In this case, the selected overflow capacity routing instruction indicates that traffic levels over 155 Mbps are to be routed to output port OP 1 .
[0041] Real-time overflow capacity routing instructions relate to usage-based bandwidth where the network user has indicated that they wish to have bursts of traffic that exceed the fixed blocks of bandwidth carried by the best backbone provider that is available at the time additional capacity is needed. The real-time overflow capacity routing instructions for an input port IP identify the output port OP that is to receive the overflow traffic from the input port IP.
[0042] For example, assume that the ISP connected to input port IP 1 purchases 155 Mbps of bandwidth from the backbone provider connected to output port OP 2 . Further assume that the backbone provider connected to output port OP 3 is the best backbone provider at the time the overflow traffic from the ISP is present. In this case, the real-time overflow capacity routing instruction indicates that traffic levels over 155 Mbps are to be routed to output port OP 3 .
[0043] Data-type capacity routing instructions relate to usage-based bandwidth where the network user has indicated that they wish to have specific types of data, such as video, carried by the best backbone provider that is available at the time the data type is present. The data-type capacity routing instructions for an input port IP identify the output port OP that is to receive the type of data from the input port IP.
[0044] In operation, router 210 receives a data packet on an input port IP. Based on the traffic level and data type on the input port IP as indicated by traffic measuring circuitry 214 , switch controller 220 controls switching circuitry 212 so that the data packet is routed to an output port OP. The output port OP, in turn, is defined by the fixed capacity routing instruction, the select overflow capacity routing instruction, the real-time overflow capacity routing instruction , or the data type capacity routing instruction.
[0045] In addition, when a network user has purchased multiple blocks of bandwidth, switch controller 220 can also use the level of traffic congestion as indicated by the congestion monitoring circuitry 218 to route the data packets among the available blocks of bandwidth.
[0046] For example, an ISP could purchase a 155 Mbps block of bandwidth from a first backbone provider, and a 32 Mbps block of bandwidth from a second backbone provider. If the ISP has 150 Mbps of data traffic and the first backbone provider is congested (such as when a router goes down), router 210 can transmit 32 Mbps onto the second backbone provider, and only 122 Mbps onto the more congested first backbone provider. Vendors such as Cisco provide routers.
[0047] As further shown in FIG. 2 , system 200 includes a route optimizer 230 . Route optimizer 230 includes a memory 232 that stores instructions and data, and a central processing unit (CPU) 234 that is connected to memory 232 . Further, route optimizer 230 includes a memory access device 236 , such as a disk drive or a networking card, which is connected to memory 232 and CPU 234 . Memory access device 236 allows instructions and data to be transferred to memory 232 from an external medium, such as a disk or a networked computer. In addition, device 236 allows data from memory 232 or CPU 234 to be transferred to the external medium.
[0048] In addition, route optimizer 230 includes a display system 238 that is connected to CPU 234 . Display system 238 displays images to an administrator which are necessary for the administrator to interact with the program. Route optimizer 230 also includes a user input device 240 , such as a keyboard and a pointing device, which is connected to CPU 234 . Input device 240 allows the administrator to interact with the Route optimizer 230 executes a route optimizer algorithm that generates the fixed capacity, select overflow capacity, real-time overflow capacity, and data-type capacity routing instructions. Route optimizer 230 receives traffic information from traffic measuring circuitry 214 , and fixed capacity sold instructions. In addition, route optimizer 230 receives selected capacity sold instructions, bandwidth seller instructions, and best provider instructions.
[0049] The fixed capacity sold instructions identify a network user that purchased a block of bandwidth, the backbone provider that sold the bandwidth, and the amount of capacity that has been purchased from the backbone provider. Utilizing this information, the route optimizer algorithm identifies the input port IP that is associated with the network user that purchased the capacity, and the output port OP that is associated with the backbone provider that sold the capacity. The route optimizer algorithm generates the fixed capacity routing instructions using the identified input port IP, the identified output port OP, and the capacity purchased.
[0050] The selected capacity sold instructions identify a network user and the backbone provider that has been selected to handle the overflow traffic. Utilizing this information, the route optimizer algorithm identifies the input port IP associated with the network user that selected the provider, and the output port OP of the backbone provider that will provide the overflow capacity. The route optimizer algorithm generates the selected overflow capacity routing instructions using the identified input port IP, and the identified output port OP.
[0051] The bandwidth seller instructions identify sellers that wish to sell usage-based bandwidth, and the cost of the usage-based bandwidth (including available discounts). The sellers include backbone providers that have usage-based capacity for sale as well as network users. Network users that have excess capacity on a backbone provider can sell the excess capacity on a usage basis.
[0052] The best provider instructions identify a network user that wishes to have their overflow traffic, or types of data, routed to the best backbone provider that is available at the time the additional capacity is needed, or the type of data is present. (ISPs can also choose to have all of their traffic routed to the best backbone provider.) The route optimizer algorithm determines the best backbone provider. FIG. 3 shows a flow chart that illustrates a method 300 of determining the best backbone provider in accordance with the present invention.
[0053] As shown in FIG. 3 , method 300 begins at step 310 by collecting destination information from destination determining circuitry 216 to determine the end destinations that can be reached with the backbone providers. Utilizing this information, method 300 moves to step 312 to develop a list of backbone providers that provides service to each end destination.
[0054] Next, method 300 moves to step 314 to evaluate the bandwidth seller instructions. In addition, method 300 modifies the list of providers to form a list of sellers by removing backbone providers that do not have usage-based capacity available for sale, and updating , the capacity that is available from sellers that have sold capacity. Further, method 300 adds network users to the list of sellers that have excess capacity on a provider that is on the list of providers.
[0055] For example, if only backbone providers A, B, and C provide service to a destination, but only backbone providers A and B have usage-based capacity for sale as indicated in the bandwidth seller instruction, then backbone provider C is removed from the list of sellers. In addition, if network users G and H have indicated that they wish to sell excess capacity on a usage basis and users G and H have excess capacity on providers A and D, respectively, then only user G is added to the list of sellers.
[0056] The usage-based excess capacity available for sale by a network user varies from moment to moment, depending on the traffic level on the input port IP. Thus, a network user that has 100 Mbps of excess capacity at one moment may have no excess capacity at a next moment, or may have 150 Mbps of excess capacity at the next moment. The present invention allows even brief periods of excess bandwidth to be sold, rerouting data packets on a packet-by-packet basis.
[0057] Once the list of sellers has been formed, method 300 moves to step 316 to rank the sellers that have usage-based capacity for sale according to a factor from lowest to highest to form a ranking of sellers. One factor that can be utilized to rank the sellers is the cost of the bandwidth (including applicable discounts). In this case, the best backbone provider is the seller that has usage-based capacity on a backbone provider at the lowest cost.
[0058] Another factor that can be utilized to rank the sellers is response times. The time it takes for a packet to reach its destination is an important factor and different networks have different response times for transferring information. FIGS. 4A and 4B show flow charts that illustrate methods 400 A and 400 B for determining response times in accordance with the present invention.
[0059] As shown in FIG. 4A , method 400 -A begins at step 410 by monitoring the traffic that is on the backbone providers to determine when pings can be transmitted. When pings can be transmitted, method 400 -A moves to step 412 where router 210 pings an identified site. Next, method 400 -A moves to step 414 to indicate that the identified site has been pinged.
[0060] Following this, method 400 -A moves to step 416 .to identify a next site to be pinged. Destination information is collected from method step 310 (or from destination determining circuitry 216 ) to develop a list of end destinations that can be reached with the backbone providers. From the list of end destinations, method 400 -A identifies a next site to be pinged using a predefined order.
[0061] Sites from the list of end destinations can be pinged in a repeating order. For example, the first through last sites could be pinged in a first to last order. Alternately, sites could be pinged in a non-repeating order using a criteria, such as total traffic volume, to vary the order. In this case, sites that received more traffic would be pinged more often. Once a next site has been identified method 400 -A returns to step 410 .
[0062] As shown in FIG. 4B , method 400 -B begins at step 420 by determining whether a ping output by method 400 -A has been received. When a ping has been received, method 400 -B moves to step 422 to determine the time required for a packet to reach that destination over the pinged backbone provider. Thus, method 400 -B continually measures the time required to send data to the destination on each of the backbone providers that provide service to the destination. If a direct measure of the time required to reach a destination is unavailable, then one-half of the round trip time can be used.
[0063] Following this, method 400 -B moves to step 424 to statistically measure the response times to form a measured response time for each backbone provider for the different sites. The backbone providers are then assigned to different ranges of response times based on the measured response times. For example, all providers providing service to a destination in X mS or less are assigned to a first range. In addition, all providers providing service to the destination in Y mS down to X mS are assigned to a second range, while all providers providing service in Z mS down to Y mS are assigned to a third range.
[0064] The ranges, in turn, can correspond to different types of data. For example, video and voice over IP may require that data packets be delivered within X mS. In addition, basic corporate traffic may require that data packets be delivered within Y mS, while standard ISP traffic may require that data packets not take any longer than Z mS.
[0065] By defining ranges of traffic, the present invention is able to provide guaranteed levels of service based on the amount of time required for a packet to reach its destination. For example, system 200 can guarantee that 99.99% of all video and voice over IP packets will reach their final destination within X mS. System 200 can also guarantee that 99.99% of all corporate traffic will reach its final destination within Y mS, and all basic ISP traffic within Z mS.
[0066] Guaranteed levels of service allow up-market, business ISPs or ISPs with many Web hosts to choose to have all of their traffic reach its destination within a time limit, or set time limits within which certain types of their traffic should be delivered. This will ensure that their traffic is routed over the backbone provider that has the best connection with the destination site. In addition to routing overflow traffic based on cost, residential ISPs may be interested in upgrading their service to allow certain applications, such as video conferencing, to reach their end destinations within set time limits.
[0067] Further, corporate virtual private networks (VPNs), which typically use leased lines, can utilize guaranteed levels of service. The cost of running a VPN is becoming increasingly expensive as companies look to use their dedicated infrastructure to carry increasingly complex and bandwidth hungry applications, such as video conferencing. This is forcing up the amount of bandwidth the VPNs require despite the fact that the VPNs may only need this large bandwidth for short periods of time. Thus, by providing guaranteed transit times, VPNs can utilize system 200 to transmit time sensitive packets.
[0068] In addition, guaranteed levels of service provide benefits to telephone companies using voice over IP (VOIP). Telephone companies within Europe and North America send most international voice traffic over IP backbones. To insure that there is no degradation to the voice service from bursty data, separate IP links are set up to carry the voice signal. Thus, by guaranteeing a level of service, the voice signal need not be sent over a separate IP link.
[0069] System 200 can only provide quality of service guarantees for outbound traffic from the exchange in which it is installed. For example, a user may request to see a Web page, and this request may be sent at the highest grade of service to the end Web host. However, the response will only be sent back at the speed provided by the host's backbone provider.
[0070] On the other hand, if system 200 is installed at both exchanges, than a guaranteed level of service can be provided for both outbound and inbound traffic. This is beneficial to ISPs, but the greatest beneficiaries are companies setting up VPNs as this allows the companies to send traffic between platforms without setting up leased lines.
[0071] This guarantee can even take into account the complex hierarchal structure of the public internet. FIG. 5 shows a flow diagram that illustrates response time measurement in accordance with the present invention. As shown in FIG. 5 , six backbone providers BB 1 -BB 6 provide various segments of a route from router 210 to an end destination 510 .
[0072] Specifically, router 210 is connected to backbone providers BB 1 , BB 2 , and BB 3 . Backbone provider BB 1 has a peering arrangement with backbone provider BB 5 at point A. Backbone provider BB 5 , in turn, is connected to the end destination 510 . In addition, backbone provider BB 2 has a peering arrangement with backbone provider BB 4 at point A, while backbone provider BB 4 has a peering arrangement with backbone provider BB 6 at point B. Backbone provider BB 6 , in turn, is connected to the end destination 510 .
[0073] After a site has been pinged a statistically significant number of times, method 400 -B could determine, for example, that it requires 20 mS for a ping to reach end destination 510 when sent via backbone provider BB 1 . The 20 mS, in turn, could require 15 mS for the ping to reach point A, and another 5 mS for the ping to reach the end destination via backbone provider BB 5 .
[0074] Method 400 -B could also determine, for example, that it requires 25 mS for a ping to reach end destination 510 when sent via backbone provider BB 2 . The 25 mS, in turn, could require 5 mS for the ping to reach point A, 10 mS for the ping to reach point B via backbone provider BB 4 , and another 10 mS for the ping to reach the end destination via backbone provider BB 6 . Further, it could additionally require 35 mS for a ping to reach end destination 510 when sent via backbone provider BB 3 , which has the only direct connection. As a result, backbone provider BB 1 provides the time-optimal choice.
[0075] Method 400 -B also utilizes traffic condition information from congestion monitoring circuitry 218 to determine response times. Thus, if congestion occurs on, for example, backbone provider BB 5 , the statistics quickly reflect this change. As a result, backbone provider BB 1 would drop from being the best to being the worst choice.
[0076] The cost and response time rankings can be used alone, in combination or in combination with other factors to determine the best backbone provider at each moment in time. For example, an ISP purchasing video service would have packets routed on the least expensive provider of all of the providers. meeting the response time criteria. When used with other factors, the network user provides the appropriate weighting.
[0077] In addition, rather than purchasing a fixed amount of bandwidth and electing to have overflow traffic routed across the best provider at the time, a network user can also elect to have all of their traffic delivered within a time limit. Alternately, the network user can elect to have types of traffic delivered within different time limits.
[0078] The present invention changes the public internet from a heterogeneous system of proprietary networks with an inconsistent performance to one where there is differentiated price associated with different grades of service. Although some prioritization or queuing techniques, such as Orchestream, exist for providing different levels of service, these solutions only work when implemented across an end-to-end network over which the packets have to travel.
[0079] FIG. 6 shows a flow chart that illustrates a method 600 of operating route optimizer 230 in accordance with the present invention. As shown in FIG. 6 , method 600 begins at step 610 by monitoring the traffic levels on the input ports IP using the traffic level information output by traffic measuring circuitry 216 . For each input port IP, method 600 determines if the traffic level is near the total of the fixed capacity blocks of bandwidth that have been purchased.
[0080] If the traffic level is not near the total fixed capacity bandwidth that has been purchased, method 600 moves to step 612 where the route optimizer algorithm evaluates the bandwidth seller instructions to determine if the ISP connected to the input port IP wishes to sell excess capacity. If the ISP does not wish to sell excess capacity, method 600 returns to step 610 . If the ISP does wish to sell excess capacity, method 600 moves to step 614 where the route optimizer algorithm runs method 300 to update the ranking of sellers, and then returns to step 610 .
[0081] If the traffic level is near the total fixed capacity bandwidth that has been purchased, method 600 moves to step 620 where the route optimizer algorithm determines whether the ISP connected to the input port IP wishes to reroute its overflow traffic. If the ISP does not wish to reroute its overflow traffic, method 600 returns to step 610 .
[0082] If the ISP does wish to reroute its overflow traffic, method 600 moves to step 622 where the route optimizer algorithm determines if the ISP has selected a backbone provider to handle its overflow traffic. If the ISP has selected a backbone provider to handle its overflow traffic (where the selected overflow capacity routing instruction controls the routing), method 600 returns to step 610 .
[0083] If the ISP has not selected a backbone provider to handle its overflow traffic, method 600 moves to step 624 where the route optimizer algorithm purchases capacity from the best backbone provider in the ranking of sellers. This real-time purchase and sale of bandwidth allows sellers the opportunity to sell capacity from moment to moment. This, in turn, allows sellers to sell significantly more of their capacity than when sellers must sell blocks of bandwidth for typically at least a month. With more bandwidth available, the cost of IP transit should fall.
[0084] In addition to purchasing capacity from the best backbone provider, method 600 generates a real-time overflow capacity routing instruction that identifies the best backbone provider. This real-time routing of excess traffic onto output lines OL where additional capacity has just been purchased allows network users the ability to buy and sell bandwidth in real time.
[0085] The real-time purchase and sale of bandwidth, and the real-time routing of excess traffic over the bandwidth purchased in real time, more efficiently utilizes-the bandwidth than the current practice where blocks of bandwidth are sold under contracts that range from one month to one year in length. A more efficient utilization of the bandwidth, in turn, reduces the IP transit costs for the participating network users.
[0086] Returning to FIG. 6 , method 600 next moves to step 626 where the route optimizer algorithm outputs a sales notification and a billing notification. Next, method 600 moves to step 614 where the route optimizer algorithm runs method 300 to update the ranking of sellers (to remove the capacity that was sold), and then returns to step 610 .
[0087] As further shown in FIG. 2 , system 200 includes a trading platform 250 . Trading platform 250 includes a memory 252 that stores instructions and data, and a central processing unit (CPU) 254 that is connected to memory 252 . Further, trading platform 250 includes a memory access device 256 , such as a disk drive or a networking card, which is connected to memory 252 and CPU 254 . Memory access device 256 allows instructions and data-to be transferred to memory 252 from an external medium, such as a disk or a networked computer. In addition, device 256 allows data from memory 252 or CPU 254 to be transferred to the external medium.
[0088] In addition, trading platform 250 includes a display system 258 that is connected to CPU 254 . Display system 258 displays images to an administrator which are necessary for the administrator to interact with the program. Trading platform 250 also includes a user input device 260 , such as a keyboard and a pointing device, which is connected to CPU 254 . Input device 260 allows the administrator to interact with the program.
[0089] Trading platform 250 executes a trading algorithm that matches buyers and sellers of bandwidth. Trading platform 250 receives network user instructions and backbone provider instructions. The network user instructions indicate the fixed capacity blocks of bandwidth that a network user has been purchased outside of system 200 , and the price and quality requirements of the network user for buying additional capacity. The quality requirements can include, for example, a desired response time and a minimum acceptable response time. In addition, the network user instructions also indicate a network users price requirements to sell their own excess capacity.
[0090] The backbone provider instructions , indicate the fixed capacity and usage-based charges of a backbone provider (along with terms and conditions such as contract length). The charges can include, for example, discounts based on volume and time of day. The network user and backbone provider instructions are input to trading platform 250 via a number of input screens that are accessed via a network, such as the internet.
[0091] The trading algorithm utilizes the network user and backbone provider instructions to develop trader information. The trader information includes lists of backbone providers that have fixed capacity for sale, and lists of backbone providers that have usage-based capacity for sale. The lists include the cost of the bandwidth, and can be sorted and arranged according to specific factors, such as quality.
[0092] The trading algorithm also utilizes data from route optimizer 230 to develop additional trader information. The additional trader information can include rankings of sellers provided by route optimizer 230 as well as usage based data. The usage based data can includes best capacity bandwidth that has been sold (as indicated by the sales notification output at step 426 ), and traffic profiles that are viewable over a number of time periods. The trader information can further include recommendations for all or any portion of the total bandwidth utilized by a network user. The trading information is accessed by network users and backbone providers via a network such as the internet.
[0093] The trading algorithm also provides a means for a network user to purchase, such as by point-and-click, fixed capacity and usage-based bandwidth from a specific provider or a recommended provider, and to also receive confirmation of the sale. The network user can also indicate that they wish to have their overflow capacity routed to the best backbone provider that is available when the additional capacity is needed. The trading algorithm also provides information that indicates the fixed capacity bandwidth that has been purchased, and the usage-based bandwidth that is to be purchased to handle the overflow traffic.
[0094] When network users purchase fixed capacity from backbone providers, the trading algorithm outputs the fixed capacity sold instructions and a sold fixed capacity notification. When network users select specific backbone providers to provide overflow capacity, the trading algorithm outputs the selected capacity sold instructions and a sold selected capacity notification. When network users indicate that they wish to use the best backbone provider to handle their overflow capacity, the trading algorithm outputs the best provider instructions. In addition, the trading algorithm outputs the bandwidth seller instructions each time bandwidth is bought or sold.
[0095] Conventional trading platforms for matching user requirements to market offerings can be modified to implement the trading algorithm running on trading computer 250 .
[0096] As further shown in FIG. 2 , system 200 also includes a billing system 270 that provides fixed capacity and usage based billing. Billing system 270 includes a number of sniffers 272 that non-intrusively extract packet header and payload information from all the data streams between the input ports IP and the output ports OP.
[0097] Billing system 270 also includes a number of aggregators 274 and a mediator 276 . Each aggregator 274 collects the raw transaction data from a number of sniffers 272 , while mediator 276 formats and compresses the raw transaction data into useful billing data. The billing data, which includes sender and receiver information, identifies data packets that have been routed according to fixed contracts as well as overflow packets that have been rerouted. Vendors such as Narus, Xacct and Belle Systems provide mediation systems.
[0098] Billing system 270 further includes a biller 278 that includes a memory 280 that stores instructions and data, and a central processing unit (CPU) 282 that is connected to memory 280 . Further, biller 278 includes a memory access device 284 , such as a disk drive or a networking card, which is connected to memory 280 and CPU 282 . Memory access device 284 allows instructions and data to be transferred to memory 280 from an external medium, such as a disk or a networked computer. In addition, device 284 allows data from memory 280 or CPU 282 to be transferred to the external medium.
[0099] In addition, biller 278 includes a display system 286 that is connected to CPU 282 . Display system 286 displays images to an administrator which are necessary for the administrator to interact with the program. Biller 278 also includes a user input device 288 , such as a keyboard and a pointing device, which is connected to CPU 282 . Input device 288 allows the administrator to interact with the program.
[0100] Biller 278 executes a billing algorithm that utilizes the billing data output by mediator 276 , the sold fixed capacity and sold selected capacity notifications output by trading platform 250 , and the billing notification output by route optimizer 230 to generate charges for the transactions in near real time. The charges reflect data packets that were actually output to a backbone provider, not the indications of a sale from route optimizer 230 .
[0101] The billing algorithm utilizes rules to define tariffs, plans, and discounts using billing events that include the type of application, such as file transfer, browser, and streaming media. In addition, the bandwidth allocated, the total bytes transferred, the time of day, the quality of service requested and delivered, and the priority are additional billing events that are used.
[0102] The billing algorithm also generates paper and/or electronic billing statements from the charges that provide both up to the minute charges as well as monthly or other periodic summaries. The billing statements can include personalized levels of summarization and itemization. The billing algorithm also provides a means for electronic bill payment using credit cards, direct debits, bank giros, checks, or via the web. The billing statements and electronic bill payment are viewable via a network such as the internet.
[0103] The billing algorithm also provides inquiry screens so that customers and customer care representatives can review the transactions. The billing algorithm also provides credit control and collections, inventory of equipment, and on-line real-time provisioning of routers and switches. The billing algorithm further includes management capabilities such as order entry, invoice reconciliation, commission calculation, reporting, and security capabilities. Vendors such as Portal, Geneva, and Solect provide billing systems.
[0104] Each network user has a traffic profile that is formed by graphing the traffic level of an input data stream against the time of day. By adding the total of the fixed capacity blocks to the graph, a peak profile can be defined as the traffic levels that lie above the total of the fixed capacity blocks.
[0105] The network users have similar peak profiles, partially overlapping peak profiles, and non-overlapping peak profiles. The more network users that have a non-overlapping peak profile, the greater the likelihood that a real-time transaction can be completed.
[0106] One way to obtain non-overlapping peak profiles is to accept incoming data streams IN from network users that focus on different customer groups, such as business and residential groups. The traffic profiles of predominantly residential ISPs are very different from business ISPs.
[0107] FIG. 7 shows a graph that illustrates a business traffic profile 710 and a residential traffic profile 720 in accordance with the present. invention. As shown in FIG. 7 , business traffic profile 710 has a peak profile 712 that lasts between about 10:00 to 14:00 hours, and excess capacity 714 to sell between about 19:00 to 23:00 hours.
[0108] In addition, residential traffic profile 720 has excess capacity 722 to sell between about 10:00 to 14:00 hours, and a peak profile 724 between about 19:00 to 23:00 hours. Thus, during a first complementary period CP 1 , the network user that outputs residential traffic profile 720 has as excess substantially all of the capacity that is needed by the network user that outputs business traffic profile 710 .
[0109] Similarly, during a second complementary period CP 2 , the network user that outputs business traffic profile 710 has as excess substantially all of the capacity that is needed by the network user that outputs residential traffic profile 710 . Thus, FIG. 7 shows that non-overlapping peak profiles can be obtained by accepting incoming data streams IN from network users that focus on different customer groups.
[0110] Thus, a system and a method for real-time buying and selling of excess bandwidth, real-time routing of excess traffic over bandwidth purchased in real time, and billing of the transactions have been described. The system and method of the present invention provide numerous advantages over the fixed contract approach that is commonly used in the industry.
[0111] One of the advantages of the present invention is that it allows network users the ability to both pay a fixed capacity fee and a usage-based fee. The fixed capacity fee provides a network user with a fixed amount of network capacity to carry the bulk of their traffic, while the usage-based fee provides for peak traffic periods.
[0112] The usage-based fee removes the need to over dimension the network, and also insures the network user that they can handle peak traffic periods. As a result, network users can buy less fixed capacity. For example, instead of purchasing a fixed capacity level which is twice the average traffic level, where there is only a 50% utilization, network users of system 200 can buy less fixed capacity and can therefore realize, for example, an 80% utilization. The net result is a cost-effective solution for network users. (The amount of fixed capacity that is optimal for each network user varies according to their traffic profile.)
[0113] Another significant advantage to network users of system 200 is that network users can sell any spare capacity on their links on a real time basis. Network users can also choose a combination of fixed capacity and usage based services, depending on their traffic profiles and traffic volumes.
[0114] An advantage to network providers is that system 200 offers network providers a way to offer usage-based charges, such as on a “per gigabit transferred basis.” This eliminates the need for the network provider to develop this ability in house.
[0115] It should be understood that various alternatives to the embodiment of the invention described herein may be employed in practicing the invention. Thus, it is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
|
An apparatus and method for real-time buying and selling of Internet Protocol (IP) transit is described. Embodiments include a platform for routing IP traffic in real time from at least one network user to a plurality of backbone providers. Embodiments further include sellers specifying a quality, a quantity, and a duration of a contract available, buyers identifying and selecting an appropriate contract, and executing the selected contract. Embodiments further include assigning different ranks to different backbone providers based on network monitoring. Other embodiments are described and claimed.
| 7
|
BACKGROUND OF THE INVENTION
The present invention relates to engine tachometers, and more particularly to a tachometer which is designed to measure the speed in revolutions per minute of a Diesel engine during the period of idle adjustment.
A known type of idle adjusting tachometer is designed so that as will be the case with gasoline engine tachometers, the primary or secondary voltage of the ignition coil is detected and the engine rpm is measured from the detection signal. However, and this prior art device has the disadvantage of being not suitable for use in vehicles equipped with Diesel engines.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a tachometer suitable for engine adjusting purposes, which is adapted for installation on all types of engines including Diesel engines and gasoline engines whereby the engine rpm can be seen directly at the location of the tachometer and thus the driver can adjust the engine idling rpm while observing the display on the tachometer.
The tachometer according to the present invention features the tachometer proper for sensing pressure changes in the engine case so as to compute and display the engine rpm. The tachometer is mounted on the oil filler port in the engine cylinder head cover (the place where the oil filler cap is fitted).
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are perspective views showing the mounting position of a tachometer according to the present invention.
FIG. 2 is a partially sectional perspective view showing the manner in which the tachometer of this invention is mounted on the oil filler port in the cylinder head cover of an engine.
FIG. 3 is a block diagram showing an embodiment of the tachometer according to the invention.
FIG. 4 is a wiring diagram showing one form of the voltage supply circuit shown in FIG. 4.
FIGS. 5 and 6 are wiring diagrams showing in detail the circuit construction of the tachometer of the invention.
FIG. 7 shows waveform diagrams useful in explaining the operation of the tachometer of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will now be described in greater detail with reference to the illustrated embodiment.
Referring first to FIGS. 1A and 1B, numeral 10 shows an exemplary form of a cylinder head cover of an engine which is in the upper portion of the engine, 11 an oil filler port through which the engine oil is introduced, 12 an oil filler cap which covers the oil filler port to hermetically seal the engine case, and 13 a schematic construction of the device proper of a tachometer, which is fixedly mounted by forcing it into the oil filler port so as to measure the engine rpm.
FIG. 2 shows the manner in which the device proper 13 is mounted on the oil filler port 11, and the cylinder head cover 10 is formed with a threaded groove 101 for mounting the oil filler cap 12. Numeral 110 shows an engine case interior, 20 a housing forming the outer shell of the device proper 13, 201 an elastic member made of rubber or the like for hermetically sealing the engine case and fixedly mounting the device proper 13 on the engine, and 202 a pressure inlet pipe for sensing pressure changes in the engine case whereby the output signal of a pressure sensor is supplied to an engine rpm signal computing circuit (not shown) which is incorporated within the housing 20. The engine rpm is indicated by a display unit 38 so as to be visible outwardly. Numeral 21 shows the direction from which the engine rpm display will be seen. Numeral 205 designates a lead wire protective member made of rubber, and 206 a lead wire.
FIG. 3 is a block diagram showing the overall circuit construction of the tachometer according to the invention. In the Figure, numeral 31 designates a voltage supply circuit having terminals 301 and 302 which are connected to a vehicle-mounted battery. In connecting the terminals 301 and 302, they have no directional properties such as positive and negative properties and thus they may each be connected to the positive or negative terminal of the battery to permit operation of electric circuits and also to produce a constant supply voltage for supplying the circuits. Numeral 32 designates a pressure sensor for sensing pressure changes in the engine case, 33 an amplifier circuit, 34 a multiplier circuit for multiplying the output of the amplifier circuit 34 for the computational purposes which will be described later, 35 a constant-frequency oscillator circuit, 36 a computing circuit for producing a periodic signal having a predetermined time width and generating a multiplication signal only during the time width, and 37 a counter/decoder circuit responsive to the output signal of the computing circuit to generate a signal for actuating the digital-type display unit 38.
With the construction described above, the operation of the tachometer according to the invention will now be described with reference to FIGS. 4 to 7. Referring first to FIG. 4 showing a wiring diagram of the voltage supply circuit 31, the terminals 301 and 302 are each connected to the positive or negative terminal of the battery. The terminals 301 and 302 are connected to a rectifier circuit comprising four diodes 41 so that a line 410 always has a positive potential and a line 411 always has a negative potential irrespective of whether the polarities of the supply voltage to the terminals 301 and 302 are respectively positive and negative or vice versa. As a result, a constant voltage is produced from this voltage by means of a transistor 43, a resistor 44 and a Zener diode 45. This constant voltage is delivered through terminals 401 and 402 to supply power to the electric circuits which will be described later.
Referring now to FIG. 5, the pressure sensor 32 includes a pressure sensing element 511 consisting for example of a known type of semiconductor pressure sensing element whose output voltage varies with pressure changes and thus the pressure sensing element 511 generates at its output a voltage signal as shown in (a) of FIG. 7 (in the case of a four-cylinder engine, for example, two pressure changes occur for every engine crankshaft revolution and two periods of the voltage signal represent one complete engine revolution). This signal is amplified by an amplifier 513 of the amplifier circuit 33 through a capacitor 512 and the signal shown in (b) of FIG. 7 appears at the output of the amplifier 513. This signal is applied to the input portion of a multiplying element 514 of the multiplier circuit 34. In this embodiment, the multiplying element 514 is of the same type as the RCA COS/MOS CD4046A. A counter 515, a NAND gate 516, an inverter 517 and a D-type flip-flop 518 produce one signal pulse at the output Q of the D-type flip-flop 518 each time the number of pulses applied to the input of the counter 515 reaches 60. As a result, if the multiplying element 514 has its terminal VCO OUT connected to the input φ of the counter 515 and its terminal COMPARATOR IN connected to the output terminal Q of the D-type flip-flop 518 and if resistors 520, 521 and 522 and capacitors 523 and 524 are connected to the multiplying element 514, a frequency which is 60 times the frequency at the terminal SIGNAL IN is generated at the output terminal VCO OUT of the multiplying device 514. In other words, if the engine speed is 600 rpm, then a pulse signal of (600×2)/60=20 Hz is applied to the terminal SIGNAL IN of the multiplying element 514 and a pulse signal of 1200 (=20×60) Hz is generated at its output terminal VCO OUT.
On the other hand, the oscillator circuit 35 generates an oscillation pulse signal of a constant frequency and the pulses are counted by a counter 531 which in turn generates at its output terminal Qn a pulse signal of 10 Hz as shown in (c) of FIG. 7. This 10 Hz signal is applied to the input of a counter 532 which in turn generates the signals shown in (d), (e), (f) and (g) of FIG. 7 at its output terminals "9", "7", "8" and CARRY OUT. The operation of the counter 532 is the same as the RCA COS/MOS Decade Counter/Divider CD4017. The CARRY OUT signal is applied to one input of a NAND gate 538 whose other input receives the previously mentioned multiplication signal shown in (b) of FIG. 7. Thus, the NAND gate 538 is opened for a time interval T 05 corresponding to the five clock pulses shown in (c) of FIG. 7 ((1/10)×5=0.5 sec in this embodiment) and thus the NAND gate 538 generates at its output the multiplication signal only during the time interval T 05 as shown in (i) of FIG. 7. In other words, if the engine speed is 600 rpm as mentioned previously, 1200×0.5=600 pulses will be present in the time interval T 05 since the multiplication signal has a frequency of 1200 Hz. In the case of this embodiment, as many pulses as the engine rpm will appear during the time interval T 05 .
A resistor 552, a capacitor 550 and an inverter 541 are provided to reset the electric circuits to the initial states upon application of the supply voltage, so that only at the instant that the supply voltage is applied, a "1" signal is generated at the output of the inverter gate 541 and the counters 531, 532, etc., are reset to the initial states. As a result, the signal at the output Q 1 of a counter 533 changes from "0" to "1" at the expiration of one second after the application of the supply voltage and the signal is applied to its ENABLE terminal through an inverter gate 534, thus maintaining the output of the inverter gate 534 in the "0" signal state. The fact that the output signal of the inverter gate 534 goes to "1" only for one second after the application of the supply voltage, has the effect of preventing any erroneous display by the display unit 38 which will be described later. Also the output signal of the inverter gate 534 is applied to the data input of a D-type flip-flop 535 whose clock input receives the previously mentioned engine rpm signal (the amplifier output signal). The D-type flip-flop 535 and the following D-type flip-flop 536 are provided to determine whether the engine rpm signal has been generated so that if it is, a "1" signal is generated at the output Q of the flip-flop 536 and NAND gates 539 and 540 are opened. On the contrary, if no engine rpm signal is present, a "0" signal is generated at the output Q of the flip-flop 536 and the NAND gates 539 and 540 are closed. The purpose of this arrangement is to prevent any erroneous display when no engine rpm signal is present.
The above-described operation results in the generation at a terminal 501 of a pulse signal having a constant frequency (about 1 KHz in this embodiment), at a terminal 502 of a pulse signal superposed by an engine rpm signal as shown in (i) of FIG. 7, at a terminal 503 of a reset signal which goes to "1" at one-second intervals as shown in (d) of FIG. 7, at a terminal 504 of the storage signal shown in (e) of FIG. 7 and at a terminal 505 of a signal which goes to "1" only for one second after the application of the supply voltage. These signals are applied to the counter/decoder circuit 37 shown in FIG. 6.
In FIG. 6, the terminals 401 and 402 are the positive and negative supply terminals. Although the terminals are shown not wired, they are connected to the associated electronic components. The counter/decoder circuit 37 includes a counter 711 which operates in the same manner as the Toshiba C 2 MOS TC 5051P 4-digit decade counter with blanking control; the counts for the respective digit positions are sequentially delivered to the BCD outputs in a dynamic manner beginning with the most-significant digit position.
Assuming now that the engine speed is 1600 rpm, the number of the engine rpm signal pulses shown in (i) of FIG. 7 and appearing at the terminal 502 amounts to 1600 pulses during the time interval T 05 as mentioned previously. In response to the SCAN IN input signal arriving at the terminal 501, the output Q 1 of the counter 711 first goes to "1" and thus "1", "0", "0" and "0" signals respectively appear at its BCD outputs A, B, C and D representing a decimal digit "1". When the output Q 1 goes to "0" and the output Q 2 goes to "1", "0", "1", "1" and "0" signals respectively appear at the outputs A, B, C and D representing a decimal digit "6". Then when the output Q 3 goes to " 1", a "0" signal appears at each of the outputs A, B, C and D representing a digit "0", and when the output Q 4 goes to "1", a "0" signal appears at each of the outputs A, B, C and D representing a decimal digit "0". The output signals from the outputs Q 1 , Q 2 , Q 3 and Q 4 are respectively applied to NAND gates 713, 714, 715 and 716 each serving as a NOT gate and operated by a large drive current; the outputs of these NAND gates drive the display unit 38. The RCA CD40107B may be used satisfactorily for each of these NAND gates.
On the other hand, the BCD outputs are applied to the corresponding inputs of a decoder 712 (e.g., the Toshiba C 2 MOS TC 5022BP BCD-to-7-Segment Decoder/Driver) and a 7-segment display drive signal corresponding to the BCD input signal appears as its outputs a to g. Thus each of four 7-segment light-emitting displays 720 of the display unit 38 is lit by the corresponding segment signal, thus displaying a decimal number "1600" as shown in the Figure.
While, in the embodiment described above, the power supply is adapted to be connected to the battery installed in a vehicle by a lead wire, a dry cell or the like may be incorporated in the tachometer to thereby eliminate the use of any lead wire.
Further, while the tachometer according to the embodiment is adapted to be forced into and fixedly mounted on the oil filler port in the engine cylinder head cover by utilizing the resiliency of rubber, the invention is not intended to be limited thereto and the tachometer may be fixedly mounted by means of a screw or the like.
Further, while the engine rpm is computed by multiplying the signal generated by detecting pressure changes, a pulse signal having a high frequency (e.g., 1 MHz) may be superposed on the signal shown in (b) of FIG. 7 so as to count the number of pulses appearing during the "1" period.
|
Pressure changes in the engine case of an automobile are sensed to compute and display the engine rpm irrespective of the types of engines. A pressure sensing element is mounted on the oil filler port in the engine cylinder head cover by means of a mounting member made of an elastic material.
| 5
|
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates in general to pulverized fuel delivery systems such as pulverized coal injection (PCI) systems for blast furnaces used in iron and steel production, and in particular to a new and unique pulverized fuel delivery system and method which uses a high pressure, variable speed solids pump for continuously providing pulverized coal to one or more blast furnaces or other users of pulverized coal.
The use of pulverized coal as a fuel for blast furnaces was first introduced approximately 35 years ago, and is a popular fuel due to its relatively low cost and widespread availability. Several different delivery systems for conveying the pulverized coal to furnaces or other combustion applications have been developed. In particular, one modern group of substantially continuous flow, high pressure pulverized coal pneumatic delivery systems is characterized by the use of atmospheric reservoirs to fill pressurized feeder tanks, which in turn supply pulverized coal to multiple injection lines or to a feed line connected to one or more distributors. The distributors convey the pulverized coal from the feed line to multiple points in a furnace or other application. The coal may be provided in what is known as "dense phase" because of the relatively high ratio of solids to volume of gas present, or it may be conveyed in dilute phase depending on the specific technology employed.
However, these known methods for continuously delivering pulverized coal fuel to blast furnaces for burning all have drawbacks, such as inefficient use of materials, space, or energy. These problems arise primarily from the difficulty of moving the pulverized coal from atmospheric pressure storage bins to higher pressure feeder or batch tanks for injection into a furnace. Also, because the pulverized coal is provided in the dense phase at high pressure, rotary feeders do not work well due to pressure limitations.
U.S. Pat. Nos. 3,689,045 and 3,720,351 to Coulter et al. both disclose a pulverized coal delivery system for providing dense phase pulverized coal to a blast furnace. An atmospheric coal grinding and collection system is combined with two or more pressurized batch or feeder tanks, preferably at least three separate feeder tanks, which are connected to one storage reservoir. While one full feeder tank is used to supply the pulverized coal to the blast furnace at high pressure, the remaining two feeder tanks may be refilled from the storage reservoir at atmospheric pressure. Once a feeder tank is filled, it is pressurized and readied to be placed online when the supply of pulverized coal in that feeder tank currently feeding the blast furnace is depleted, thus maintaining a substantially continuous pulverized coal fuel flow into the blast furnace. This cycle is continuously repeated, such that one feeder tank is always online and feeding the blast furnace, while the remaining two feeder tanks are at varying stages of refilling with pulverized coal and/or recharging to high pressure.
More particularly, the pulverized fuel delivery systems of Coulter et al. operate such that each batch tank in these systems is cycled continuously in the following sequence:
a. At atmospheric pressure (vented), the feeder tank is filled by gravity flow from a pulverized fuel reservoir located above through a connecting pipeline.
b. Once filled, a valve in the fill pipeline is closed and the feeder tank is pressurized with inert gas.
c. Once pressurized, the feeder tank is in the ready condition and remains in standby until the on-line feeder tank is empty.
d. When the time comes for the ready tank to go on-line, e.g., to begin feeding pulverized fuel to the blast furnace, a valve in the discharge line located below the tank opens and pulverized fuel in dense phase flows out under pressure into the fuel transport and distribution system which connects the tank to the furnace.
e. Once the tank is nearly empty, the pulverized fuel discharge valve closes and the feeder tank pressure is vented down to atmospheric pressure. This completes the cycle which generally requires a time span of 30 to 90 minutes.
Another common form of high pressure solids feed system employs two tanks in series, and is shown in schematically in FIG. 1. The first tank, commonly referred to as a lock hopper, receives solids materials from an atmospheric storage reservoir by gravity flow. This first tank is then closed and pressurized to a pressure equal to the pressure of the second or feed tank. A drain valve in the first tank is opened to release the material into the feed tank. Once the first tank is emptied, it is depressurized and refilled for another cycle.
Other known methods for continuously transporting fine solids in dense phase include the cascading pressure continuous blow bottle disclosed by U.S. Pat. No. 5,265,983 to Wennerstrom et al. The Wennerstrom et al. patent provides for the continuous filling of a blow bottle, which takes the place of multiple feeder tanks. This device employs a single variable speed rotary feeder in combination with one or more constant speed rotary feeders in a cascade arrangement. The upper variable speed rotary feeder is capable of handling 20 psig differential pressure, while the lower constant speed feeders are designed for higher differential pressures up to 50 psig. Continuous venting of the rotary feeders is necessary to prevent up-draft of gas through the feed system. In a high pressure system, the continuous venting of the feeders will result in a large quantity of compressed gas (typically nitrogen or N 2 ) being lost, and this wasted nitrogen is a costly element in the overall system.
U.S. Pat. No. 4,392,438 to Dooley discloses a coal transport system for delivering a pulverized coal fuel from a remote point directly to a furnace or alternately to a storage chamber. The system disclosed in the '438 patent uses coal gas to pressurize the system and force the pressurized coal from a processing and pulverizing plant through a pipeline having a series of booster stations used to maintain pressure to a furnace. The system of the '438 Dooley patent is similar in concept to that of the present invention, however it does not use a high pressure variable speed solids pump to maintain and initiate the fuel flow into the furnace, nor does it concern itself with filling and maintaining a fuel level in a feeder tank.
U.S. Pat. No. 5,285,735 to Motoi et al. discloses a control apparatus for injection of a particular quantity of pulverized coal into a blast furnace. This patent does not disclose the use of a high pressure variable speed solids pump either, but merely a different means of controlling the level of coal in a feed tank for supplying the furnace. The Motoi et al. patent uses additional pressurizing gas to maintain the pressure within the feed tank while varying the rate at which the feed tank is filed with the control system. The Motoi et al. patent's apparatus uses a conveying gas in conjunction with a pressurized gas and a series of valves to achieve similar results as are achieved with the high pressure pump of the present invention which requires much less equipment.
It is thus apparent that an improved pulverized fuel delivery system that can reduce or eliminate: the cycling of multiple batch tanks, the disruptions that occur when one such batch tank is taken off line and another is started, and the venting of significant quantities of pressurizing gas, would be welcomed by the industry.
SUMMARY OF THE INVENTION
It is a primary object of this invention to improve upon and streamline the process of continuously providing atmospheric pressure pulverized coal to a high pressure solids feeder tank for supplying a blast furnace or other application.
Accordingly, a system is provided in which solids, such as pulverized coal, are provided to and stored at atmospheric pressure in a reservoir, from where the solids are discharged by gravity in dense phase flow and continuously conveyed to a high pressure feeder tank through a variable speed, high pressure solids pump, preferably of the type disclosed in U.S. Pat. Nos. 4,516,674; 4,988,239; and 5,051,041 to Firth. However, in most instances it is envisioned that deaeration means will have to be provided just upstream of the solids pump to maintain proper inlet conditions so that the pump will operate properly. The high pressure feeder tank may be connected to a blast furnace or other application which requires a continuous supply of solids, such as pulverized coal, through a dense phase discharge line. In some systems the dense phase discharge may be diluted with the addition of gas for improved flow characteristics.
The high pressure solids pump both meters the flow of solids into the feeder tank and increases the pressure from atmospheric pressure. This system for filling the high pressure feeder tank may be operated continuously and the speed of the pump may be controlled so that a nearly constant level of solids may be maintained in the feeder tank. Preferably, the pump will be capable of providing solids to the feeder tank at least as rapidly as the solids are discharged from the tank outlet for use. As a result, this system eliminates the need for more than one high pressure feeder tank for each application which it is supplying with solids.
The reservoir may have fluidizing gas added near the outlet to facilitate the dense phase flow of solids into the pump. Additional fluidizing gas may also be provided to the outlet of the feeder tank, in order to maintain the dense phase flow through the discharge line and assist in regulating the discharge flow. Pressurizing gas is added to the feeder tanks to further assist the regulation of the discharge flow and maintain the pressure in the feeder tank to the required process pressure which may normally range from 5 to 20 atmospheres, although other pressures may be maintained depending on the application.
Valves may be added at one or more points between the reservoir and feeder tank to assist in depressurizing and isolating parts of the system for cleaning and maintenance purposes. Further, vents may be provided on the feeder tank for assisting with the pressure adjustment of the tank and helping to regulate the flow out of the feeder tank while operating.
In one application of the present invention, additional solids pumps may be added in parallel with the first pump to supply the same tank or other feeder tanks from the same reservoir. The different pumps and feeder tanks do not have to have the same capacity requirements and their fill levels may be maintained independently of each other, although they may have identical characteristics. The additional feeder tanks may be modified existing feeder tanks from the known two or three feed tank supply systems described above, thus utilizing existing equipment and avoiding large costs to implement the system of the present invention.
The process of the present invention requires providing solids to a reservoir maintained at atmospheric pressure, passing the solids to a variable speed, high pressure solids pump, using the pump to pressurize the solids and convey the solids to a pressurized feeder tank. The solids may then be supplied to an application such as a blast furnace by conveying the solids from the feeder tank through a discharge line or other apparatus.
The new system and process of the invention is advantageous for many reasons. The use of a continuous pump supplying one feeder tank eliminates the need for more than one feeder tank, or for a lock hopper transfer tank and as a result, eliminates the venting of significant quantifies of pressurized gas which occurs in known systems when individual batch feeder tanks or lock hoppers are depressurized. It also eliminates the disruption in the feed system which occurs when switching between batch tanks.
Advantages over other systems include the elimination of the need to continually vent the system to prevent blow-back of solids since the pump helps to generate the pressure. And, because the solids pump is capable of providing higher pressure levels independently, the need for a series of pumps to pressurize and convey the solids is eliminated.
Accordingly, one aspect of the present invention is drawn to a continuous high pressure solids supply system which comprises a source of solids, and a dense phase discharge conduit for conveying the solids in a dense phase flow. This discharge conduit will preferably include deaeration means which allow the solids material to deaereate just prior to entering a variable speed, high pressure solids pump. The deaeration means allows the entrained gas to flow back to the source of the solids, typically a reservoir, via an external conduit. The deaeration means is located just ahead of the pump inlet. Alternatively, some applications will not require a separate deaeration means to accomplish this function; in such cases the solids are self-deaerating, the entrained gases flowing back up to the reservoir through the dense phase discharge conduit itself. The high pressure solids supply system further comprises a variable speed, high pressure solids pump having a pump inlet and a pump outlet, the pump inlet connected to the deaeration means in the discharge conduit. Finally, a feeder tank is connected to the solids pump outlet. The feeder tank is maintained at a higher pressure than the source of solids, and also has an outlet to provide the solids to the process of interest, typically a blast furnace.
Another aspect of the present invention is drawn to a method for continuously conveying solids. The steps of this method include providing a source of solids to a reservoir. The method discharges the solids from the reservoir into a discharge conduit in a dense phase flow. The dense phase flow of solids is deaerated and then enters a variable speed, high pressure solids pump. The solids pump is used to increase the pressure of the solids flow. The dense phase flow of solids is then discharged to a feeder tank which is maintained at a higher pressure than the pressure in the reservoir. The solids in dense phase flow are then provided to an application through an outlet of the feeder tank. The solids pump is controlled such that a substantially constant level of solids is maintained in the feeder tank.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic representation of a known series tank arrangement also known as a lock hopper system;
FIG. 2 is a schematic drawing of a first embodiment of the system of the present invention;
FIG. 3 is a schematic detail drawing of the discharge conduit portion of the system of FIG. 2, illustrating the deaeration means of the present invention in greater detail;
FIG. 4 is a schematic drawing of one application of the present invention wherein one reservoir supplies plural feeder tanks in parallel; and
FIGS. 5(a)-5(d) are schematics of other embodiments of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings generally, wherein like numerals represent the same or functionally similar elements in the drawings, and to FIGS. 2 and. 3 in particular, one aspect of the present invention is drawn to a high pressure solids supply system, generally designated 90. The system 90 has a collection and storage reservoir 10 with reservoir outlet 11. Reservoir outlet 11 provides a dense phase flow of solids, advantageously pulverized coal, into a dense phase discharge conduit 13 which has an isolation valve 14. The solids will eventually be conveyed to a variable speed, high pressure solids pump 20 at pump inlet 19. FIG. 2 further discloses one preferred embodiment of the invention which includes a deaerator means 15 containing a gas permeable internal conduit 16, a deaerator jacket 17 and a vent 18. As shown in greater detail in FIG. 3, since the solids must be fluidized with fluidizing gas 12 to enable them to be discharged from the reservoir 10, the deaeration means 15 is required to maintain proper, deaerated conditions in the solids at the pump 20 inlet so that pump 20 will maintain its seal. The gas permeable internal conduit 16 has a wall which is advantageously made of a fabric filter material, such as Gore Tex® or the like, which will allow the gases to pass therethrough but which will retain the fine solids within the gas permeable conduit 16. Other suitable filter materials could be porous ceramics, metals or polymers. Gases passing through the filter wall of conduit 16 are conveyed into an annular space defined between conduit 16 and jacket 17 and then back into the reservoir 10 at vent 18. Alternatively, the deaerator vent gas may be vented to atmosphere and/or may be induced by a exhauster fan (not shown). The deaerator means 15 may employ a means to stimulate flow and prevent pluggage by applying vibration to the deaerator means 15, as schematically indicated at 120. It may also utilize a pneumatic pulse means 125, for applying a pneumatic pulse inside the deaerator jacket 17 which will stimulate the material flow inside the gas permeable conduit 16.
Referring back to FIG. 2, the storage reservoir 10 is typically maintained at atmospheric or near atmospheric pressure. The storage reservoir 10 may be inerted (such as with nitrogen or N 2 ) from a source 8 of inerting gas or remain uninerted, depending on the combustibility of the fine solids therein. Pump outlet 21 connects to feeder tank 30, which has its outlet 31 connected to discharge line 39. Discharge line 39 is connected to an application such as furnace 40.
Collection and storage reservoir 10 is supplied with solids, such as pulverized coal, from solids source 16. Reservoir 10 has fluidizing gas 12 provided near outlet 11 to fluidize the solids within the reservoir 10 to maintain a dense phase flow through outlet 11 and into the discharge conduit 13. In one embodiment, reservoir 10 may have one or more vent inlets 18 near its top.
As indicated above, the reservoir 10 is usually at atmospheric pressure, and may be filled from solids source 16 by any known means, including but not limited to gravity, a belt type feeder, or a rotary feed pump, all schematically indicated at 7.
Solids pump 20 is preferentially a modified version of a high pressure solids pump available from STAMET, Incorporated, and is capable of transferring and metering solids. For details of the basic solids pump configuration, the reader is referred to the aforementioned U.S. Pat. Nos. 4,516,674; 4,988,239; and 5,051,041 to Firth. Modifications that will be necessary include those needed to operate at the required pressures, and/or to meet safety requirements which may be imposed by local, state, or national codes for materials which have explosive or other hazardous characteristics. The pump 20 also increases the pressure between the reservoir 10 and feeder tank 30, and serves as a pressuring boundary therebetween. Solids pump 20 is powered by a variable speed electric motor (not shown), which may be controlled by known means so that the solids are properly metered into the feeder tank 30 and to keep the feeder tank 30 at a nearly constant fill level.
Metered and pressurized solids leave pump outlet 21 at a higher pressure than in the reservoir 10, are conveyed to pressurized feeder tank 30. The pump 20 is controlled by a control system 55 which varies the speed of the electric motor (not shown) driving solids pump 20, based upon signals indicative of the weight of feeder tank 30 provided by load cells or level sensors schematically indicated at 50. The control system 55 provides a control signal to the electric motor (not shown) via line 57, schematically shown being provided to pump 20 for simplicity. The solids pump 20 is operated in such a manner so as to affect whatever fine solids process flow is discharged from the bottom of the feeder tank 30 via discharge line 39. Manual (via a human operator) or automatic control signals 80 from other systems may also be provided to the control system 55, based upon process conditions, such as those occurring within blast furnace 40. System data signals, schematically represented at 85, can be provided to remote locations to apprise operators of operating conditions.
Feeder tank 30 has outlet 31 at its lower end connected to discharge pipe 39. Fluidizing gas 34 is provided at inlet 35 adjacent feeder tank outlet 31 to ensure that the solids material is in the dense phase flow when it leaves the feeder tank 30. A pressurizing gas 32 is supplied to the tank at pressurizing gas inlet 33, to help maintain the pressure within the feeder tank 30. The pressure within the feeder tank 30 is preferentially between 5 and 20 atmospheres. A vent 38 may be provided near the top of the feeder tank 30 for reducing the pressure within the feeder tank 30. Fluidizing gas 34, pressurizing gas 32 and vent 38 all assist in regulating the flow of dense phase solids through tank outlet 31 and discharge pipe 39.
Feeder tanks 30 may also employ variable speed rotary feeders or similar devices 41 at tank outlet 31 to regulate flow from the tank 30 to the process of interest, as well as isolation valve 42.
Discharge pipe 39 connects the feeder tank outlet 31 to intermediate distribution systems (not shown), when needed, and applications such as blast furnace 40.
Isolation valves 14 and 22 may be provided between reservoir outlet 11 and pump inlet 19, and pump outlet 21 and feeder tank 30, respectively. The isolation valves 14, 22 are useful for keeping the lower pressure reservoir 20 separated from the higher pressure feeder tank during cleaning and maintenance. Vent 38 may be added to feeder tank 30 and can be used to reduce the pressure inside the tank 30. A vent filter 36 is added to the vent line to remove unwanted particles from the vented gases, which can be maintained in the system 90 by returning it to reservoir 10 through inlet 18.
One application of the present invention is shown in furnace supply system 100 of FIG. 4. Supply system 100 has a single reservoir 10 which receives solids in the form of pulverized coal from sources 16 and 17. Coal source 17 includes reclaimed pulverized coal from sources such as baghouse filters and cyclones (not shown). Coal source 16 includes the primary source of pulverized coal such as from a pulverizer or crusher (not shown).
The coal in reservoir 10 is fluidized to a dense phase flow as before by fluidizing gas 12 injected near reservoir multiple outlets 11a-11c. In this case, three lines are shown, but more are possible if the capacity of the reservoir 10 will allow it, and one line, as shown in FIG. 1, or two are also within the scope of this invention. The remaining elements of the system 100 may be identical, or different, in their requirements and capacities. In this example, the remaining elements in each line are substantially identical, although this is not intended to limit the scope of the invention, as it is the intention of this invention that each line is independent of the others.
From multiple outlets 11a-11c, the dense phase flow travels through conduits 13a-13c and isolation valves 14a-14c to pump inlets 19a-19c, where variable speed high pressure solids pumps 20a-20c raise the pressure between reservoir 10 and feeder tanks 30a-30c. Conduits 13a-13c are preferably vertical but may be sloped only in that part of the conduit where the material is aerated and flowing in dense phase. Before the solids stream becomes deaerated either by back venting in conduit 13a-13c or by separate deaerator means 15, the flow must be vertical into the pump inlets 19a-19c. Pumps 20a-20c transfer the dense phase flow to the higher pressure region, and eject the flow from pump outlets 21a-21c, where the flow is conveyed through isolation valves 22a-22c to feeder tanks 30a-30c. It should be noted, that as with the system 90 of FIG. 1, the isolation valves 14a-14c and 22a-22c are not required for normal operation of the invention, but are used to assist in cleaning and maintenance of the system 100. Each pump 20a-20c is controlled by control system 55 which varies the speed of the electric motor (not shown) driving each solids pump 20a-20c, based upon signals indicative of the weight of feeder tank 30a-30c provided by load cells or level sensors schematically indicated at 50. The control system 55 provides a control signal to each of the electric motors (not shown) via line 57, schematically shown being provided to pumps 20a-20c for simplicity. Each solids pump 20a-20c is operated in such a manner so as to affect whatever free solids process flow is discharged from the bottom of each feeder tank 30a-30c via discharge lines 39a-39c. Manual (via a human operator) or automatic control signals 80 from other systems may also be provided to the control system 55, based upon process conditions, such as those occurring within blast furnaces 40a-40c. System data signals, schematically represented at 85, can again be provided to remote locations to provide system status information to the operators.
The pulverized coal that was transported as a dense phase flow to the feeder tanks 30a-30c is stored until it is again fluidized by fluidizing gas 34, injected near tank outlets 31a-31c at fluidizing inlets 35a-35c. While the pulverized coal is in the feeder tanks 30a-30c, the pressure is maintained in part by pressurizing gas 32, supplied to each feeder tank 30a-30c at pressurizing gas inlets 33a-33c. The pressurizing gas 32 may be adjusted for each tank to assist in controlling the flow of pulverized coal leaving the tank. Additionally, as shown in FIG. 2, a single source for each of the fluidizing gas 34 and pressurizing gas 32 may be used in combination with valves (not shown) to control the supply of each gas to the feeder tanks 30a-30c, or individual sources may be used.
In this system 100, each feeder tank 30 is again provided with a vent 38a-38c, for removing pressurized gases from the system. Each vent line has an isolation valve 37a-37c and recycles gases to and terminates at reservoir vent inlet(s) 18. The vents 38a-38c and associated isolation valves 37a-37c and lines are not necessarily required in this system 100, and are included for cleaning and maintenance and additional pulverized discharge flow control in the feeder tanks 30a-30c. A vent filter 36 would typically be provided to reservoir 10, eventually venting to atmosphere (ATM) as shown.
Finally, each feeder tank 30a-30c is used to supply a discharge line 39a-39c which is connected to an application, in this case three blast furnaces 40a-40c. These furnaces may be separate furnaces, or the discharge lines may connect the pulverized coal supply of two or more feeders 30a-30c to different combustion areas of the same furnace 40a-40c. An isolation valve 42a-42c is provided in each discharge line 39a-39c to shut off the flow of dense phase pulverized coal to the furnaces 40a-40c if necessary, but the valves 42a-42c are not required for operation. Again, a rotary valve means 41a-41c may also be provided if needed.
There are three primary advantages of this invention vis-a-vis the classic batch type or lock hopper feed system:
1. The continuous pump system eliminates the cycling of multiple batch tanks and their associated fill valves, pressurizing valves, on-line dense phase flow valves and vent valves. These valves are typically severe duty valves which require significant maintenance.
2. The continuous pump system eliminates the disruption in solids feed which occurs in a batch tank system when one tank goes off line and another comes on line. Also, because the continuous feed system maintains a constant fine solids inventory in the feed tank, there is no feed rate change which may occur in a batch tank whose inventory is reduced from full to near-empty during a feed cycle.
3. The continuous pump system eliminates the venting of significant quantities of pressurized gas which occurs at the end of a batch tank feed cycle or a lock hopper charge cycle. This vented gas wastes the energy of compression normally supplied by motor driven compressors and the value of the gas itself if it is vented to an atmospheric discharge point. It also eliminates the need for large vent filters and their associated installation, operation, and maintenance costs.
The continuous pump system of the present invention also has two major advantages over the cascading pressure continuous blow bottle system of U.S. Pat. No. 5,265,983 to Wennerstrom et al.:
1. The multiple rotary feeders employed by the continuous blow bottle must each be vented to prevent blow-back of pressurized gases coming from the pressurized feed tank (blow bottle). This gas has a compression energy component which is lost and may discard gas which has some value as in Item 3 above.
2. The rotary feeders that are employed by the continuous blow bottle have relatively low differential pressure capability when compared to the solids pump. Hence, multiple or cascading rotary feeders are needed for higher pressure systems which complicates the system, adds initial cost and increases operation and maintenance costs.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. For example, while the present invention is particularly suitable as part of a pulverized fuel delivery system for blast furnaces used in the manufacture of iron and steel, it could also be used to transport such fuels to other types of furnaces, for other purposes. Similarly, the solids material need not be a fuel, but instead could be other types of pulverized material that needs to be transported from a region of atmospheric pressure to another region at superatmospheric pressure. Several alternative arrangements of the present invention using the high pressure free solids pump could accomplish the purpose intended:
1. An arrangement without the pressurized feed tank. The solids pump would discharge directly into a high pressure conduit for fluidization and conveying to the process.
2. An arrangement that contains two high pressure fine solids pumps, one upstream of the high pressure feed tank and one at the feed tank outlet. This outlet pump would take the place of feed tank pressurizing gas as the means to regulate flow out of the feed tank and into the process.
3. An arrangement that contains two or more solids pumps in parallel between a single storage bin or reservoir and a single pressurized feed tank. This arrangement would allow for greater capacity or for redundancy in case of a pump failure.
4. An arrangement that contains two or more pumps in series for cases where one pump cannot achieve the pressure rise required by the system. Pumps in series would be in a cascade scheme, each delivering fine solids at higher pressure to the next pump.
5. Any combination of storage bins pumps and pressurized feed tanks that are appropriate for the process requirements. For instance, in the case of blast furnace pulverized coal injection, a single large pulverized coal bin could be utilized for the injection of coal into multiple furnaces by using multiple solids pumps and pressurized feed tanks arranged in parallel under the storage bin.
These various alternative arrangements are shown schematically in FIGS. 5(a)-5(d). Like numerals designate the same or functionally similar elements. Since the particular functions and details have thus been mentioned previously, a detailed description of such modifications have been omitted herein for the sake of conciseness and readability, but properly fall within the scope and equivalents of the following claims.
|
A system and method for continuously supplying solids from a lower pressure storage reservoir to a high pressure feeder tank for use in an application such as a blast furnace employs a high pressure variable speed solids pump. A fluidizing device discharges solids in a dense phase flow to a deaerating device for deaerating the solids flow prior to entering a variable speed high pressure solids pump. A feeder tank having an outlet is connected to the outlet of the solids pump and the feeder tank is at a higher pressure than the source of the solids.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This patent application is a continuation of U.S. patent application Ser. No. 09/881,631 filed on Jun. 14, 2001 now U.S. Pat. No. 6,597,768 which claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/212,388 filed Jun. 19, 2000, the entire contents of which is hereby expressly incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to the field of voice and data communications, and in particular, a method and apparatus for coupling a voiceband modem circuit to a common phoneline connector for use in a home network communications system.
Referring to FIGS. 1 a - 1 e , an evolution of home based communications systems is depicted.
In FIG. 1 a , plain old telephone service (POTS) wiring 102 , generally unshielded twisted pair (UTP) wiring, at customer premises 104 couples POTS telephones 106 through subscriber loop 108 to a telephone company central office, which, in turn, is connected to the public switched telephone network (PSTN). Customer premises 104 is a telephone subscriber site that has arranged (generally for a monthly telephone service fee or for a per call minute fee) with a local provider (such as a local telephone company) for a connection to the central office. The central telephone office (also called a local exchange) provides local switching and non-local switching via the PSTN.
In FIG. 1 b , computer 110 through conventional voice modem 112 can also be coupled to POTS wiring 102 to allow the transmission of signals from computer 110 to be transmitted onto the telephone network. Voice modem 112 will be described in more detail below.
In FIG. 1 c , there is depicted a conventional local area network (LAN) 114 (such as an ethernet network using coaxial cable) installed at customer premises 104 in addition to any POTS wiring 102 that may be in place to connect, for example, computer 110 with computer 110 a.
In FIG. 1 d , computers 110 and 110 a , rather than being connected via LAN 114 as seen in FIG. 1 c , connects and utilizes POTS wiring 102 as a LAN transmission medium in accordance with the Home Phoneline Network Alliance (HPNA) specifications for the LAN computer interconnection over existing telephone lines within the local environment.
In FIG. 1 e , computer 110 , while implementing an HPNA LAN via POTS wiring 102 , can also implement broadband digital data services through digital subscriber line (xDSL) modem 116 , including one which supports asymmetrical digital subscriber line (ADSL) protocol, coupled to POTS wiring 102 .
While broadband data services using DSL, or similarly cable modem or fixed wireless transceivers, are now being regularly deployed in home environments, there is still a need for basic connectivity using legacy voiceband data modems. Moreover, in the case of DSL and particularly ADSL, the broadband service may use the same physical metallic pair over which the voiceband modem signals travel to the PSTN central office, though at higher frequencies. In many cases, there may be no splitter (low-pass filter) between the in-premise wiring and the local loop.
Therefore, a need exists for a method and apparatus for attenuating high-frequency interfering signals, such as splitterless ADSL or phoneline network signals, at the front-end of a voiceband modem. The present invention provides a solution to this problem and will enable low-cost voiceband modems which use line-powered DAAs to be able to effectively connect to the PSTN.
SUMMARY OF THE INVENTION
In accordance with the present invention a method and apparatus for coupling a voiceband modem circuit to a common phoneline connector is provided, the common phoneline connection having a ring line connection and a tip line connection which couples a ring/tip line pair to a subscriber loop circuit, the voiceband modem circuit operating in a voiceband modem operating frequency band and having a voiceband modem interface ring line and a voiceband modem interface tip line.
In particular, in one embodiment of the present invention the voiceband modem interface ring line is coupled to the ring line and the voiceband modem interface tip line is coupled to the tip line connection by inserting, between the ring line connection and the voiceband modem interface ring line and between the tip line connection and the voiceband modem interface tip line, a series pair of inductors. A first inductor of the series pair has a low inductance and a high self-resonant frequency and a second inductor of the series pair has a high inductance and low self-resonant frequency. The low inductance, the high self-resonant frequency, the high inductance and the low self-resonant frequency are each determined to locate a filtering cutoff point between the voiceband modem operating frequency band and a digital subscriber line operating frequency band.
In another embodiment a method and apparatus for coupling a voiceband modem circuit and a digital subscriber line circuit to a common phoneline connector is provided, the common phoneline connection having a ring line connection and a tip line connection which couples a ring/tip line pair to a subscriber loop circuit, the voiceband modem circuit operating in a voiceband modem operating frequency band and having a voiceband modem interface ring line and a voiceband modem interface tip line, the digital subscriber line circuit operating in a digital subscriber line operating frequency band and having a digital subscriber line interface ring line and a digital subscriber line interface tip line. The voiceband modem interface ring line and the digital subscriber interface ring line are coupled in parallel to the ring line. The voiceband modem interface tip line and the digital subscriber interface tip line are coupled in parallel to the tip line connection. The coupling the voiceband modem interface, ring line and the coupling the voiceband modem interface tip line is by inserting, between the ring line connection and the voiceband modem interface ring line and between the tip line connection and the voiceband modem interface tip line, a series pair of inductors. A first inductor of the series pair has a low inductance and a high self-resonant frequency and a second inductor of the series pair has a high inductance and low self-resonant frequency. The low inductance, the high self-resonant frequency, the high inductance and the low self-resonant frequency are each determined to locate a filtering cutoff point between the voiceband modem operating frequency band and the digital subscriber line operating frequency band.
In still another embodiment a method and apparatus for coupling a voiceband modem circuit and a home phoneline circuit to a common phoneline connector is provided, the common phoneline connection having a ring line connection and a tip line connection which couples a ring/tip line pair to a subscriber loop circuit, the voiceband modem circuit operating in a voiceband modem operating frequency band and having a voiceband modem interface ring line and a voiceband modem interface tip line, the home phoneline circuit operating in a home phone line operating frequency band and having a home phoneline interface ring line and a home phoneline interface tip line. The voiceband modem interface ring line and the home phoneline interface ring line are coupled in parallel to the ring line. The voiceband modem interface tip line and the home phoneline interface tip line are coupled in parallel to the tip line connection. The coupling the voiceband modem interface ring line and the coupling the voiceband modem interface tip line is by inserting, between the ring line connection and the voiceband modem interface ring line and between the tip line connection and the voiceband modem interface tip line, a series pair of inductors. A first inductor of the series pair has a low inductance and a high self-resonant frequency and a second inductor of the series pair has a high inductance and low self-resonant frequency. The low inductance, the high self-resonant frequency, the high inductance and the low self-resonant frequency being each determined to locate a filtering cutoff point between the voiceband modem operating frequency band and the home phoneline operating frequency band.
In yet still another embodiment a method and apparatus for coupling a voiceband modem circuit, a digital subscriber line circuit and a home phoneline circuit to a common phoneline connector is provided, the common phoneline connection having a ring line connection and a tip line connection which couples a ring/tip line pair to a subscriber loop circuit, the voiceband modem circuit operating in a voiceband modem operating frequency band and having a voiceband modem interface ring line and a voiceband modem interface tip line, the digital subscriber line circuit operating in a digital subscriber line operating frequency band and having a digital subscriber line interface ring line and a digital subscriber line interface tip line, the home phoneline circuit operating in a home phoneline operating frequency band and having a home phoneline interface ring line and a home phoneline interface tip line. The voiceband modem interface ring line, the digital subscriber interface ring line and the home phoneline interface ring line are coupled in parallel to the ring line. The voiceband modem interface tip line, the digital subscriber interface tip line, and the home phoneline interface tip line being coupled in parallel to the tip line connection. The coupling the voiceband modem interface ring line, the digital subscriber interface ring line and the home phoneline interface ring line and the coupling the voiceband modem interface tip line, the digital subscriber interface tip line and the home phoneline interface tip line is by inserting, between the ring line connection and the voiceband modem interface ring line and between the tip line connection and the voiceband modem interface tip line, a series pair of inductors. A first inductor of the series pair has a low inductance and a high self-resonant frequency and a second inductor of the series pair has a high inductance and low self-resonant frequency. The low inductance, the high self-resonant frequency, the high inductance and the low self-resonant frequency are each determined to locate a filtering cutoff point between the voiceband modem operating frequency band and the digital subscriber line operating frequency band.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a - 1 e show in block diagram form home networking environments within which the present invention can be implemented.
FIG. 2 shows a frequency diagram in accordance with an implementation of the present invention.
FIGS. 3-5 show in block diagram form overviews of representative voice band modems with which the present invention may be implemented.
FIG. 6 shows in block diagram form a combination phone networking transceiver and voiceband modem with which the present invention may be implemented.
FIGS. 7-8 show in block diagram form a combination phone networking transceiver, DSL modem and voiceband modem with which the present invention may be implemented.
FIG. 9 shows in circuit diagram form a depiction of a realistic inductor.
FIG. 10 shows in block diagram form an embodiment of the present invention.
FIG. 11 shows in block diagram form a more detailed depiction of an embodiment of the present invention.
FIGS. 12 a and 12 b show in circuit diagram form a more detailed depiction of an embodiment of the present invention.
FIG. 13 shows in block diagram form a further implementation of an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 depicts the typical frequency plans used by voiceband modems, HPNA, and one example of DSL (e.g.,ADSL), over telephone wires, such as the system depicted in FIG. 1 e . Voiceband modems would occupy frequency band 111 (300-4000 Hz). ADSL upstream would occupy frequency band 113 (26-138 kHz). ADSL downstream would occupy frequency band 115 (138 kHz-1.104 MHz). An HPNA implementation, such as the Broadcom Corporation family of iLine (tm)family of controllers, would occupy frequency band 117 (4-10 mHz).
Generally, the DSL service and the voiceband modem will not be used simultaneously. However, as voiceband modems are used in facsimile transmissions, a voiceband modem connection for fax transmission may occur while the DSL service is in use. Also, in some residential applications, the DSL service may be used to access the Internet in general (for personal use), but a voiceband modem (e.g. V.90) may be used to connect to one's place of work for security reasons. In some cases, the DSL service may be inaccessible due to routing problems at the local telephone service provider or internet service provider (ISP) but the DSL signal may still be present on the metallic pair (e.g.,transmitting IDLE patterns). In these cases, it is desirable that the performance of the voiceband modem be not adversely impacted by the presence of the DSL signal. Adverse impact means reduction in connection probability or in maximum data throughput. Since the DSL signals use higher frequencies than voiceband modems, it may be possible to use a simple low-pass filter (LPF) to attenuate the interfering DSL signal before the voiceband modem signal is sampled and quantized (digitized) by an analog-to-digital converter (ADC) for further processing by the receiving voiceband modem. However, the filtering must be performed before the ADC to avoid aliasing of the high-frequency signal into the range of frequencies used by the voiceband modem.
Referring now to FIG. 3 , in many voiceband modems, typical data access arrangement (DAA) integrated circuit (IC) 118 and interface components 120 coupled between codec IC 122 and telephone line ring/tip lines 139 , provide a high-voltage telephone line interface and protect other circuits in the modem from the DC loop current, the ringing signal, and surges. Low-voltage codec integrated circuit 122 contains an analog-to-digital converter (ADC) for the receive path, a digital-to-analog converter (DAC) for the transmit path, and all of required low-pass filtering 124 to prevent aliasing and interference with higher frequencies. Since the filtering is implemented on an IC, it can be made at low cost.
Alternatively, required low-pass filtering 124 may be performed with discrete components between the DAA and the codec as shown in FIG. 4 , or directly before the DAA, as shown in FIG. 5 . In all of these cases, the filters may be implemented with small components that do not need to withstand high voltages across them or have high currents carried through them.
However, in some voiceband modem products, such as the Broadcom Corporation Model BCM94211 Voiceband Modem and Phoneline Networking Transceiver, the DAA IC derives its power source for operation from the telephone line itself. Some DC loop current is drawn by the DAA from the central office battery, and, as tip and ring may be reversed, an external diode rectifier bridge is used to ensure the correct polarity of the inputs. Ordinarily, when the voiceband modem takes the telephone line off-hook (active), no less than 6 Volts DC is present across the device. The voiceband modem signal at tip and ring of the telephone line is roughly 2 Volts peak-to-peak when the modem is transmitting. This AC signal sums with the DC bias from the line, resulting in a time-varying voltage which drops as low as 4 Volts. The DAA's need to see a specified minimum voltage at its power supply input pin, the rectifier bridge's two diode drops, in addition to other losses before the DAA, do not leave much margin for correct circuit operation. If a DSL upstream signal is added across tip and ring and not attenuated prior to the rectifier bridge, it is likely that the DAA will not get a clean source of line power, and the voiceband modem will fail to connect or connect at a lower rate.
One straightforward solution to the problem would appear to involve installing a passive POTS microfilter at the input to the voiceband modem device. These microfilters are commonly installed by telephone companies providing splitterless DSL service, and they are attached either at the wall jack or the telephony device to protect the telephony device from high-frequency interference. This would appear to be a feasible, if expensive, solution provided that the voiceband modem is not a “combo” device, in which, for example, a voiceband modem and a phoneline networking transceiver are combined on one printed circuit board and connected to the phone line with a single connector. FIG. 6 shows an example of such a combo device, wherein phoneline networking transceiver 130 for an HPNA implementation and voiceband modem 132 are coupled in parallel to POTS phoneline RJ-11 connector 134 at ring/tip lines 139 . Similarly, a combo device could also be expanded to include a voiceband modem, a DSL modem, and a phoneline networking transceiver on one printed circuit board. FIG. 7 shows an example of such an expanded combo device, wherein phoneline networking transceiver 130 , voiceband modem 132 and DSL modem 136 are coupled in parallel to POTS phoneline RJ-11 connector 134 at ring/tip lines 139 .
Referring to FIG. 8 , another straightforward solution would appear to involve merely adding two high-valued inductors (e.g. 5 mH) 140 a , 140 b in series with each of the ring/tip lines 139 connections of the implemention depicted in FIG. 7 . If the value of these inductors is sufficiently-high, the high-frequency ADSL interfering signal will be sufficiently-attenuated before the rectifier bridge. However, the inductors must also not have a value high enough to significantly attenuate the voiceband modem signal, which occupies spectrum to 4000 Hz. The problem with this solution, referring to FIG. 9 , is that a practical inductor 150 behaves more like ideal capacitor 152 in parallel with the series combination of resistor 154 and ideal inductor 156 . Therefore, at higher frequencies, above the so-called “self-resonant frequency” ωr=1/√{square root over (LC)}, the inductor's impedance actually drops with frequency, acting like a capacitor. The self-resonant frequency of the larger inductors tend to be low, in the hundreds of kHz. However, there is presently no commercially-available technique for building low-cost, high self-resonant frequency large inductors. Accordingly, the front-end of the voiceband modem with these large inductors would start to look like a short circuit at higher frequencies, affecting the performance of both the DSL downstream band and also the higher-frequency home phoneline network. Also, there arises a conflict between the need for a high inductance value, such as 5 mH, and the ability to handle a large DC current, such as 125 mA. (These inductors must be able to pass a DC subscriber loop current of up to 125 mA without saturating when the DAA goes off hook.) These conflicting requirements lead to bulky and expensive inductors and therefore it is important to minimize the filter complexity and the number of these inductors required.
Referring now to FIG. 10 , phoneline networking transceiver 130 and voiceband modem 132 are coupled to RJ-11 connector 134 at ring/tip lines 139 (as in FIG. 6 ). However, between voiceband modem 132 and the ring/tip connections at ring/tip lines 139 , low-valued inductor 200 (e.g. 47 μH) with high self-resonant frequency (tens of MHz) is placed in series high-valued inductor 202 (e.g. 5 mH) with low self-resonant frequency (hundreds of kHz to a couple of MHz) at both tip and ring lines. Since the impedance of the ideal inductor is directly proportional to frequency, the use of the lower-valued, high-self-resonant-frequency inductor sufficiently protects the higher-frequency services from unwanted attenuation due to insertion of this device into the phone network. However, the high-valued, low-self-resonant-frequency inductor protects the voiceband modem receiver, and its line power source, from the ADSL upstream signal. Inductors 200 , 202 are in essence valued to locate the filtering (cutoff) point between voiceband modem band 111 and ADSL upstream band 113 as shown in FIG. 2 . At frequencies below the self-resonant frequency the inductors look like a true inductor, while at frequencies above the self-resonant frequency the inductors look like a capacitor. In the representative embodiment of series inductances as described above, the 5 mH inductor (a relatively high value inductance dictated by the filtering frequency desired) has a low-resonant frequency whose inductive properties for the voice modem cutoff frequency are extended out to a higher frequency than can be obtained by an individual 5 mH inductance. This inductive properties extension is achieved by providing the additional 47 μH inductor in series with the 5 mH inductor. In essence, the combination merely has a 5 mH inductance value because of the relatively small μH amount being added to a mH amount. Therefore, when the 5 mH inductor starts to operate like a capacitor, the 47 μH inductor will operate like an inductor and extend the inductive behavior out to a higher frequency. Therefore, the low-value inductor is low relative to the 5 mH (high value) inductor dictated by the filtering cutoff requirement, e.g., the values being of a two order of magnitude difference in values. The two orders of magnitude in inductor value will produce approximately two orders of magnitude difference in self-resonance frequency value.
Referring to FIG. 11 , the principal components of an embodiment of the combo device depicted in FIG. 10 , for example, the Broadcom Corporation Model BCM94211, is shown implementing the present invention. Phoneline networking transceiver 130 includes bandpass filter/magnetics circuit 140 coupled between ring/tip lines 139 and analog front end 142 . Transceiver and modem interface 144 is coupled to analog front end 142 . Voiceband modem 132 includes line interface/protection circuit 150 coupled between high-valued inductor 202 and DAA IC 152 . Voiceband modem 132 also includes codec 154 coupled between DAA IC 152 and transceiver and modem interface 144 .
Referring now to FIGS. 12 a and 12 b , the interfaces between ring/tip lines 139 , inductors 200 , 202 , interface/protection circuit 150 and bandpass filter/magnetics circuit 140 of FIG. 11 are shown in more detail. In FIG. 12 a , the interface between ring/tip lines 139 , and interface/protection circuit 150 is shown in more detail. Interface/protection circuit 150 is coupled to codec 154 (shown in FIG. 11 ) through standard DAA IC 152 and with ring/tip lines 139 through pairs of inductors 200 , 202 . Interface/protection circuit 150 includes diode protection bridge 160 for voltage polarity sensing. Diode protection bridge 160 includes filtering capacitor 162 and forms the low-pass filtering with the pairs of inductors 200 , 202 . Interface/protection circuit 150 also includes zener diode protection device 164 . Interface/protection circuit 150 includes transistor switch sub-circuits Q 2 , Q 3 , Q 4 with accompanying biasing resistors. DAA 152 includes by-pass capacitor sub-circuits 166 , 168 which are in parallel with filtering capacitor 162 . However, the capacitance values of by-pass capacitor sub-circuits 166 , 168 being in the pf range add little to the capacitance provided by filtering capacitor 162 which is in the uf range. In FIG. 12 b , bandpass filter/magnetics circuit 140 includes transformer T 1 coupled to transmit TX and receive RX lines of analog front end 142 . Bandpass filter/magnetics circuit 140 includes filter 141 and noise suppression capacitor 143 and is coupled to ring/tip lines 139 . Ring/tip lines 139 connect to RJ-11 connector 134 . Ring/tip lines 139 include therebetween over-voltage protection device RV 1 .
Another possible embodiment of this invention is set forth in FIG. 13 , wherein an expanded combo device of that shown in FIG. 7 is depicted. Phoneline networking transceiver 130 , voiceband modem 132 and DSL modem 136 are coupled in parallel to POTS phoneline RJ-11 connector 134 at ring/tip line 139 . In accordance with the present invention comparable inductors 200 and 202 can be interfaced with voiceband modem 132 and provide appropriate filtering such that interference signals from phoneline networking transceiver 130 and/or DSL modem 136 will not impact the operation of voiceband modem 132 in the same manner as described above for the combo device having merely the phoneline networking transceiver and the voiceband modem.
Therefore, in accordance with the present invention a circuit is provided for attenuating an interfering DSL signal within a voiceband modem while passing the voiceband modem signal to the remainder of the voiceband modem receiver path with negligible loss. The circuit is inserted at the line input to the modem, protecting line-powered DAAs from interference. It also does not affect the performance of the upstream or downstream DSL signals or the performance of home networks that share the same phone line, as it does not present a near short-circuit input impedance at higher frequencies. In addition, it enables devices to be implemented that combine voiceband modem, DSL, and/or home phoneline networking functionality.
|
A method and apparatus for coupling a voiceband modem circuit to a common phoneline connector, the common phoneline connection having a ring line connection and a tip line connection which couples a ring/tip line pair to a subscriber loop circuit, the voiceband modem circuit operating in a voiceband modem operating frequency band and having a voiceband modem interface ring line and a voiceband modem interface tip line. The voiceband modem interface ring line is coupled to the ring line and the voiceband modem interface tip line is coupled to the tip line connection by inserting, between the ring line connection and the voiceband modem interface ring line and between the tip line connection and the voiceband modem interface tip line, a series pair of inductors. A first inductor of the series pair has a low inductance and a high self-resonant frequency and a second inductor of the series pair has a high inductance and low self-resonant frequency. The low inductance, the high self-resonant frequency, the high inductance and the low self-resonant frequency are each determined to locate a filtering cutoff point between the voiceband modem operating frequency band and a digital subscriber line operating frequency band.
| 7
|
RELATED APPLICATIONS
[0001] This application claims priority from Provisional Application Ser. No. 60/220,863, filed on Jul. 26, 2000.
FIELD OF THE INVENTION
[0002] This invention relates generally to data processing systems, and more specifically, to a system and method for obtaining and presenting data offline and online through customization of the operating system.
BACKGROUND OF THE INVENTION
[0003] A personal computer generally obtains data from the Internet or other on-line source according to an online protocol that requires downloading to thepersonal computers, in real-time, data stored at a network location. For example, advertisements are downloaded to a user's computer from a network location as the ads are being displayed. This process requires network connectivity and may use system resources that are needed by other applications, thereby delaying the processing of these other applications. Further, displaying advertising information according to a conventional method of computer network-based advertising is generally intrusive to the user's workspace. For example, advertising information may be displayed via, for example, a floating bar in the user's workspace.
[0004] Alternatively, ads may be buffered into local storage as they are downloaded. This method still requires online connectivity and uses system resources that may be needed by other applications to perform regular refreshing of the ads. Further, the ads are generally displayed in a manner which intrudes on the user's workspace. Also, for purposes of assessing payment, the ads downloaded and displayed must be counted—a process that further uses computer resources that may be needed by other applications.
[0005] Accordingly, a need exists for a manner of computer network-based data downloading that overcomes the shortcomings of conventional methods. Namely, extending data display to offline computing time, avoiding data, such as advertisements, being downloaded with every new page view (which generally slows down online activity) and displaying advertisements in a manner that is less intrusive to the user's workspace.
SUMMARY OF THE INVENTION
[0006] This invention provides a system and method for extending computer network-based data presentation to offline time. This invention also allows the downloading of data, such as advertisements, news information, entertainment, etc., to occur during online sessions in periods with otherwise little or no data transmission. Additionally, the downloaded data may be displayed without intruding on the user's workspace. A method according to an embodiment of the invention may run as a background process on the user's computer. When the user initiates an online session, the user's computer may automatically initiate communication with a server to start downloadingdata. The downloading process may be adjusted to reflect the user's online activity. For example, during periods of significant data transfer, such as during the loading of a new web page, which requires use of a significant amount of bandwidth, the downloading process, for the advertisements or the like, is significantly reduced, or even paused, until sufficient bandwidth is available.
[0007] According to one embodiment, a method for obtaining and presenting information to a user is provided. Data is received at a user device. The data may be obtained via a downloading process that is adjusted to reflect on-line activity at the first device. The data may then be stored at the first device. The downloaded data can be presented to the user regardless of network connectivity of the user device.
[0008] In a further embodiment, it is determined when data is to be downloaded to a first device. It is also detected when the first device is online. When data is to be downloaded and when the first device is on-line, a download of data is initiated at the first device. The data is downloaded based on the on-line activity of the first device. The data may then be presented to the user via the first device, regardless of network connectivity of the first device.
[0009] According to another embodiment of the invention, a computer system for providing targeted information to users is provided. A server device is provided as part of the system. The server device includes means for receiving a plurality of information messages, the information messages being associated with at least one of a plurality of target audiences; a profile manager for managing user profiles, the user profiles including information to associate users with the target audiences; a content supplier providing a format of the information message for the user; an upload component storing the plurality of information messages; a server component receiving requests for information messages, the requests including data to associate the request with a user profile; and means for sending information messages in response to the requests, the information messages being determined by comparing the target audience for the information message and the user profiles.
[0010] In an exemplary embodiment of the invention, each time a user goes online, the user's computer sends a message to a server, indicating a unique user ID. The user ID may be assigned to the computer after an initial system installation. The message may also include a request for new data, such as the number of ads the computer would like to receive (which, in one embodiment, corresponds to the number of ads that have been viewed). The server confirms the validity of the user ID by, for example, comparing the user ID to a user profile stored on the server. Upon completing this confirmation, the server sends to the user's computer the requested data, such as the number of ads of the type that the user's profile indicates are most suitable (“targeted ads”). The received data or ads may be stored locally on a storage device, such as a hard drive, at the user's computer.
[0011] In one embodiment, when data is displayed to, or viewed by, a user it is marked accordingly, and may be overwritten by other data the next time the user goes online.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 depicts an exemplary computer network suitable for using the advertising system of the invention;
[0013] [0013]FIG. 2 depicts an exemplary SQL database;
[0014] [0014]FIG. 3 depicts an exemplary schema of the data exchange between a client and a server in the invention;
[0015] [0015]FIGS. 4 and 5 depict further details of the client cache; and
[0016] [0016]FIGS. 6 and 7 depict flow diagrams of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention provides a system and method for obtaining data and for presenting data to a user when the user is both on-line and off-line. Data can be received at the user's computer via a downloading process. The data may include information messages such as advertisements, news articles etc. The downloading process can be adjusted to reflect the on-line activity of the user's computer. As the data is being downloaded, it may be stored at the user's computer, for example on a hard drive. The downloaded data can then be presented to the user, regardless of the network connectivity of the user's computer.
[0018] The system and method of the present invention may be implemented in a client server environment, which is well known to those skilled in the art and is not described in detail herein, and the functions may be performed via computer software. In a preferred embodiment, the user's computer may determine when information is required, and initiate a request for information from the server. The server can determine, based on a user profile for the user, which data to provide to the user's computer. The system and method of the present invention are particularly suited for use in on-line advertising and is described below in that context. However, it will be recognized by those skilled in the art that the invention can be applied to many other environments.
[0019] The system and method of the invention may use various screens, including, for example, the desktop/wallpaper, startup and shutdown screens, and screen savers to display data and information to users. Existing PC functionality can be utilized to display information to a user's desktop. The data may be delivered to the user in a variety of formats, including, for example, video, or audio. In this invention, unlike in conventional online advertising systems, the user's computer may initiate the communication with the server to request, for example, advertising information. This makes it much easier for advertisements to be delivered through, for example, corporate firewalls.
[0020] The data can be downloaded to the user's computer from a server. The downloaded data may be stored at the user's computer in, for example, an “ad battery”. The downloaded data may then be displayed to the user. Thus, a user need only be online for the time required to request and receive data from the server. The downloaded data can be stored locally and displayed to the user regardless of network connectivity. For example, ad screensavers may be displayed while a user is online or offline.
[0021] In an exemplary embodiment, which data is presented to the user is tracked. For example, once an ad has been displayed to a user, a software program resident on the user's computer marks the ad accordingly and displays a different ad the next time. Each time a user goes online, i.e., establishes a network connection, data that has already been displayed may be replaced with new data, i.e., new ads are downloaded to the user's PC and stored in the ad battery. If the user does not go online during a specified number of PC sessions and the local supply of unseen ads is exhausted, the ads stored in the ad battery may be re-displayed to the user. These additional displays may or may not be tracked.
[0022] Ads may include an ad-rating feature that allows a user to rate the ad. This feature may be in the form of, for example, selectable radio buttons marked with various rankings, e.g. poor to excellent. This rating information may be aggregated and saved by the system, and sent to the server at specified times. Users may be rewarded for rating ads.
[0023] As mentioned above, if a user does not establish a network connection for, for example, two consecutive computer sessions, previously viewed ads (those ads stored in the local ad battery) may be rotated and re-displayed to the user. Because the system tracks the ads displayed, it can determine how much to charge an advertiser based on the number of clients sent the ador the number of times the ad is viewed. Each advertiser is typically charged once, for one ad display. Thus, when ads are rotated, the advertiser may not be charged for additional displays of the ads.
[0024] The software resident on the user's computer may automatically be loaded at boot-up. The software can include a system tray icon that is visible to the user. This icon allows the user to change the system settings. For example, when the icon is double-clicked, a modified preference screen may appear. The screen allows the user to: turn off the program during the current user session, and temporarily or permanently disable or re-enable ad space, or data display, functionality. This preference screen may also include a history of the previous ads that were displayed, for example, the last twelve ads and html links to the advertiser for each may be displayed on this modified preference screen. A user may also temporarily disable the system via the system tray icon. If the system is temporarily disabled, no ads will be shown for the remainder of the current session, but ads will be displayed during the next boot-up. Furthermore, the wallpaper and screensavers can incorporate a “live link button” which also activates a browser and takes the user to the advertiser's site. The system may also provide additional features. For example, a user may “touch” a screensaver without removing it by holding the “Shift” key down before moving the cursor (and during the mouse movement and click).
[0025] [0025]FIG. 1 depicts an exemplary computer network suitable for using the online/offline system of the present invention. The network includes, for example, a client and a server. The client may include a client cache, a system register, and a web browser, such as, Microsoft Internet Explorer™. The client may be installed on, for example, a workstation running a Microsoft Windows™ operating system. The server can serve as a conduit between information providers, such as third party advertisers, and the user's computer. That is, the server serves as the hub for communication and transactions between users and advertisers. Advertisers send ads to the server and indicate a target market for the ad. The ad may be stored at the server and sent to a user when the user's computer makes a request. Ads can be sent to any number of users, depending on, for example, the number of people the advertiser has paid to reach.
[0026] The server may run on a machine running, for example, Java Servlet Engine implementing Java Servlet API 2.1. The server may also be connected to an SQL database server that has a suitable JDBC driver. This database stores user profile and resource information for users. FIG. 2 depicts such an exemplary SQL database.
[0027] The server is a basic technological component and may have multiple functionality. The server may be one or more servers that are able to function together to provide a certain functionality. Specific tasks may be split between physical servers, or they may reside on the same server. According to one embodiment of the invention, the server identifies a user, via the ID, for example, and determines which data, such as ads, are available for download by the client. This may be done by classifying ads by profile groups, etc. As described above, the ads may be stored in the ad bank and the server should also determine the address from which the ads will be downloaded. This address is then provided to the client. The client can then begin the download at the earliest possible time. This data may be delivered by the same server, or a physically separate server, depending on server availability.
[0028] In the disclosed embodiment, the server may include two services: a profile manager, and a content supplier. The profile manager manages user profiles. It includes various fields for collecting profile information from the user. A user's profile may include, for example, name, address, hobbies, etc. This profile information may be stored on the server and may be used when delivering ads to the client. Several clients may share the same profile. The profile manager can distinguish between clients with the same profile to track ads. Users may be divided into groups according to their user profile information. Each group may be targeted to receive specific ads. The content supplier service provides a client with different wallpaper images, screensavers, startup and shutdown screens, etc. The content supplier service may, but does not necessarily, consider profile settings when sending ads to the client.
[0029] The server stores a user profile for each registered system user, and stores the ads that may be provided to a client. Communication between the client and the server occurs over a network using, for example, the HTTP and XML protocols. System features may further be accessible through a proxy server that supports the HTTP protocol. The server may be localized geographically, in a country or region. This allows for local advertising content, and localizes risks associated with a server crashing. The server may include two components: an ad upload area and an ad server area. The ad upload area stores ads which have been created and approved for client presentation. Ads may be specially “tagged” for display to specific users, according to a user's indicated preferences, or other profile information, described further below. While this tag may allow for overlap between user profiles, it may also be very specific, limiting the presentation of certain ads to specific clients. The other component of the server, the ad server, receives an ad reload request from the end user's PC and responds by sending new ads to the user. It determines which ads to send according to the user profile stored on the server.
[0030] [0030]FIG. 3 depicts an exemplary schema of the data exchange between a client and a server when a network connection is detected. When the client logs in to the server, the server searches, for example, a profile manager to determine the profile of the client. When a user establishes a network connection, the client checks a cache, explained further below relative to FIGS. 4 and 5, to determine which resources need to be refreshed and initiates a communication with the server. According to the information stored about the content that has been downloaded to it, the client can determine which resource(s) have already been displayed and should be overwritten with new data.
[0031] [0031]FIGS. 4 and 5 depict further details of the client cache. The client cache can maintain a separate list for different types of ads that are downloaded (e.g., wallpaper, screensaver, etc.). For each ad type, the filename of a particular ad and an indication of whether the ad has been displayed are stored. The client cache farther includes an index for each list that points to the resource that is currently in use. According to the information in the client cache, the client determines which resources, i.e., ad types, have already been displayed and should be refreshed. The client application may be, for example, native Win32, running in the system tray. In the case of, for example, screensaver ads, the system register keeps track of whether a particular screensaver ad has been displayed, or viewed. Generally, rather than maintaining a log of which ads have been displayed, it “marks” or “flags” a particular ad as having been displayed. Thus, when an ad is displayed to the user, it is indicated, or “marked,” as being displayed (or viewed). This flagging or marking may be done in code. Detailed information about which ads have been displayed may be stored at the user's computer and updated when a previously displayed ad is overwritten with a new one.
[0032] [0032]FIGS. 6 and 7 depict flow diagrams of an embodiment of the present invention. A user downloads the system software to a client computer. Once the compressed, self-installing file is fully downloaded, double-clicking on it launches the installation program. A profile window is then displayed to the user, asking the user to enter certain information that will be used to develop his profile. This may include information about the user's specific preferences for receiving information. The profile information is then stored on the user's computer until the next online session (after the first re-boot) at which point it is sent to the server. Via the preference screen, a user may answer personal questions, such as age, sex, educational level, salary, hobbies, etc. The user may further indicate what type of information is preferred and which is not preferred. For example, the preference screen may allow a user to affirmatively decline particular advertisements, or types of advertisements. After the user has completed the profile window's data requests, the computer is re-booted (then or later) to complete installation of the software. During the next online session, the server generates a unique profile identification code for the user and sends a copy of the code back to the client for storage. This profile registration should execute only once, upon the initial installation of the system.
[0033] The next time a user establishes a network connection, the unique user ID is provided to the server and is checked against the stored user profile, allowing for information, such as ads, to be properly targeted according to the profile. The server may also analyze the user's IP address to determine additional user information (such as geographic location, type of browser used, etc.). The stored preference information and the IP address analysis can be used to develop an accurate user profile. Users can then be grouped according to their profiles into various advertiser-requested classifications.
[0034] During the next online session, the user's computer, i.e., the software application on the client device may send a login request to the server. The login request should include information that allows the profile manager to identify the user, for example, an indication of the client's unique user ID. A content information request may also be sent to the server. The content information request should include a request for data from the server and may be included with the login request. If the client does not have a user identification code, when sending the content information request to the server, a default user identification code, for example, 0 may be used. In response, the server assigns the client a user identification code. A login request may include the following:
[0035] http:“\\server\servlet\profile?ProfileID=1234.
[0036] In response to the request, the server replies with a login packet response. The login packet response to the client may include a content manager address and specify content periods. This reply may be in the form of XML. The content manager address indicates from where the new ads will be downloaded, and the content periods indicate the frequency with which ads may be changed. For example, the wallpaper may be changed only once, five minutes after login. Similarly, startup or shutdown screens may be changed each time they are presented. When the client receives this content manager address and content period information, it sends a content information request to a content manager. The content manager may be a server or a portion of a server dedicated to act as a “librarian” for data, such as ads. A request for a specific ad is fulfilled by the content manager, that is, a specific ad is made available for downloading by the client. The content manager can also ensure that the advertisers get only the exposure that they paid for, for example, delivery of ads to a certain number of users. When enough users view a specific ad, the content manager ensures that a different ad (that matches the user's profile) is delivered. A login response packet from the server may include the following:
[0037] <XML>
[0038] <LOGIN>
[0039] <CONTENT MANAGER>
[0040] <CMPARM NAME=“Address” VALUE=“content Manager URL”/>
[0041] </CONTENT_MANAGER>
[0042] <TIMEOUTS>
[0043] <TIMEOUT NAME=“Relogin” VALUE=“[−1[n]”/>
[0044] <TIMEOUT NAME=“Wallpaper” VALUE=“[−1[0]n]”/>
[0045] <TIMEOUT NAME=“ScreenSaver” VALUE=“[−1[0]n]”/>
[0046] <TIMEOUT NAME=“Startup” VALUE=“[−1[0]n]”/>
[0047] <TIMEOUT NAME=“Login” VALUE=“[−1[0]n]”/>
[0048] </TIMEOUTS>
[0049] </LOGIN>
[0050] </XML>
[0051] In the above example, the following timeout values may be used: “−1”=do not perform action; “0”=request now; and “n”=number of minutes to wait. The client uses URLs from the response packet to obtain new resources. One of ordinary skill in the art will appreciate that the URLs may point to zipped files to decrease the transfer time.
[0052] After a content information request is made, the content manager may respond back to the client with a response including the following:
[0053] <XML>
[0054] <CONTENT [ATTRIB=“UserID”]>
[0055] <CITEM NAME=“LoginDlg” VALUE=“valid url”/>
[0056] [
[0057] <CITEM NAME=“Wallpaper” VALUE=“valid url”/>
[0058] <CITEM NAME=“Startup” VALUE=“valid url”/>
[0059] <CITEM NAME=“Screensaver” VALUE=“valid url”/>
[0060] ]
[0061] </CONTENT?>
[0062] [
[0063] <SYSTEM>
[0064] <SYS NAME=“Message”>
[0065] Message text goes here.
[0066] </SYS>
[0067] <SYS NAME=“Action” VALUE=“relogin”>
[0068] <ISYS>
[0069] </SYSTEM>
[0070] ]
[0071] </XML>
[0072] During an online session, the user's computer may request data, such as ads, from the server. When the user establishes a network connection, the client checks its cache to determine which data need to be refreshed or replaced and if some of the data need to be refreshed or replaced, initiates a communication with the server. In this request, the user's computer may request a specific amount of data, for example a specific number of ads. These ads will be presented to the user during the next PC sessions. The ads may include two startup screens, four wallpaper screens, four screen savers, and two shutdown screens. Therefore, when the user next turns on the PC, one of the startup screen ads will be displayed. Immediately thereafter, the first wallpaper ad may be displayed. After a specified period of time, e.g., five minutes, the wallpaper may be switched to a second wallpaper screen, depending on the content period. During this PC session, if the computer sits idle for a specified period of time, e.g., two minutes (or another time indicated by the PC's desktop settings), an ad screensaver may be displayed. When the user shuts down the system, a shutdown ad may be displayed. One of ordinary skill in the art will appreciate that while the various ads have been given descriptive names, different ad screens may be available with different operating systems. For example, for users using a PC running Windows 2000, there will be a pre-login screen instead of the startup screen, and there will be no shutdown screen.
[0073] The system may further include a process for determining whether an ad has actually been viewed. A “proven view” may be defined as any time when all programs and windows are closed during a user session, giving a clear and unobstructed view of the wallpaper. In this case, instead of ads being changed according to a pre-set time schedule, ads may be changed after a proven view.
[0074] Although the foregoing description has been described with reference to a specific implementation, those skilled in the art will know of various changes in form and detail that may be made without departing from the spirit and scope of the invention. For example, ads may be delivered to users in a variety of presentation formats, including audio, video, and scent. Moreover, instead of personal computers, the data can be downloaded to PDAs, wireless phones, WAP devices, etc.
|
A system and method for extending computer network-based data presentation to offline time is provided. Data, such as advertisements, news information, entertainment, etc., can be downloaded during online sessions in periods with otherwise little or no data transmission. Additionally, the downloaded data may be displayed without intruding on the user's workspace. A method according to an embodiment of the invention may run as a background process on the user's computer. When the user initiates an online session, the user's computer may automatically initiate communication with a server to start downloading data. The downloading process may be adjusted to reflect the user's online activity. For example, during periods of significant data transfer, such as during the loading of a new web page, which requires use of a significant amount of bandwidth, the downloading process, for the advertisements or the like, is significantly reduced, or even paused, until sufficient bandwidth is available.
| 6
|
BACKGROUND
[0001] Exploration, production, and monitoring of hydrocarbon and water deposits entails the measurement of subsurface characteristics and the evaluation of the obtained data to determine petrophysical properties of interest for the relevant formation or reservoir. A variety of techniques have been developed to measure subsurface characteristics. These techniques involve the subsurface deployment (usually through a borehole traversing the formations) of several different measurement and telemetry systems to provide data regarding the subsurface characteristics of interest, and data regarding the state of tools or instruments disposed downhole.
[0002] Among the various data collection and logging techniques routinely employed, systems for obtaining measurement data while drilling have proven to be cost effective. Logging While Drilling (LWD) and Measurement While Drilling (MWD) techniques are well known in the art. Logging While Tripping (LWT) systems have also been developed as an alternative to LWD and MWD techniques. In LWT, a small diameter “run-in” tool is sent downhole through the drill pipe, at the end of a bit run, just before the drill pipe is pulled. The run-in tool is used to measure downhole characteristics as the drill string is extracted or tripped out of the hole. In these types of systems, obtained data is either stored in downhole memory for later processing or transmitted to the surface using telemetry means, such as mud flow telemetry devices in the case of LWD/MWD systems.
[0003] Regardless of the conveyance means used for downhole tools, a shared requirement of the various measurement and telemetry systems is the need for electrical power. With the exception of wireline systems, it is difficult to convey electric power from the surface through the conveyance means to the components of the logging tools or the telemetry means. In these cases, electrical power can however be provided by downhole sources. Conventional systems obtain such power downhole either from a battery pack or a turbine-based alternator. Battery packs provide an energy storage medium. When using batteries, electrical power is made available until the battery is depleted. Turbine-based alternators provide an energy conversion device. In this case, electrical power is made available only when the energy source to be converted into electrical power is present.
[0004] Examples of alternators used in downhole logging tools are described in U.S. Pat. Nos. 5,517,464 and 5,793,625. An example of an alternator-like electrical torque-generator is described in U.S. Pat. No. 5,265,682. Turbine-based alternators employ rotors having impellers that are placed in the high-pressure flow of drilling fluid (“mud flow”) inside the drill string so that the impeller blades convert the hydraulic energy of the drilling fluid into rotation of the rotor. The rotor rotates at an angular velocity that provides enough energy to power the telemetry means and/or other components (e.g., sources/sensors) in the telemetry tool, and in some cases other tools in the downhole assembly.
[0005] Examples of battery packs used in downhole logging tools are described in U.S. Pat. Nos. 6,187,469 and 6,575,248. An example of a testing while drilling tool powered at least in part by a battery module disposed in the tool collar is described in U.S. Pat. No. 7,124,819 (assigned to the present assignee and entirely incorporated herein by reference). Battery packs are charged at the surface and provide electrical power to a single tool. Some batteries packs may be recharged downhole.
[0006] FIG. 1 shows a conventional land-based drilling rig 10 with connected drill pipe leading into a borehole 12 drilling through a subterranean formation F. At the tip of the drill string 14 is a drill bit 16 followed by a bottom hole assembly (BHA) 18 comprised of drilling, telemetry, and MWD/LWD tools. The borehole 12 is formed by rotary drilling in a manner that is well known. Drilling fluid or mud is pumped to the interior of drill string 14 to flow downwardly through the string. The drilling fluid exits drill string 14 via ports in the drill bit 16 , and then circulates upwardly through the annular space between the outside of the drill string and the wall of the borehole as indicated by the arrows. These conventional systems are powered both in a distributed fashion, wherein an individual tool in the string contains its own battery, and in a centralized fashion, wherein an individual tool draws power from a downhole turbine.
[0007] FIG. 2 shows a conventional design for supplying power in a downhole system such as the drilling assembly of FIG. 1 . Each tool in the BHA has its own dedicated battery 20 . A single conductor, combined low electrical power and low speed communications bus 22 is used through all tools in the string. A low electrical power source is provided by a turbine, usually disposed in the telemetry tool, and energized by the mud flow. It should be appreciated that the bus 22 does not provide electrical coupling between the battery disposed in one tool and electrical components disposed in another tool. This configuration offers restricted spacing (a large spacing) between sources/sensors 24 in the string and presents handling and reliability issues. Thus a need remains for improved power distribution techniques for subsurface systems.
SUMMARY
[0008] The present disclosure provides a flexible architecture and modular method of supplying power to downhole tools and instruments. Aspects of the disclosure include a modular power sub to supply the power needs for downhole tools in a centralized manor in which a single power source can be used to simplify the BHA by removing the need for a power source in each tool or component in an assembly. The power subs disclosed herein provide more power in a flexible manner, such as to cover both flow and no flow measurements in while-drilling applications. In addition, it is also contemplated that the BHA may include one or more power subs, optionally with varying power outputs, which may provide the BHA with additional flexibility and modularity. For example, the BHA may be stacked with multiple power subs, running in series or parallel, that provide the BHA with additional or greater power. One potential benefit is to provide a more compact BHA, where the location of the power sub can be customized as desired for any drilling operation. An additional potential benefit of having power subs is that a frame of the power sub (e.g. a chassis and/or collar) may be used with a plurality of tools/BHAs, thereby reducing the inventory and design time associated with storing and/or designing frames for the various tools. Another potential benefit of centralizing and sharing the power sources amongst the tools of the BHA is to prevent failure of one particular tool caused for example by the depletion of its battery. In the proposed configurations, all tools of the BHA may be simultaneously powered and provide useful measurements as long as the centralized power source is available. While the failure of a single tool does not usually justify the end of the drilling operation, the depletion of a centralized power source may justify the end of the drilling operation. In this case however, the end of the drilling operation occurs at a time where an optimal use of the downhole power has been achieved.
[0009] Other aspects of the disclosure include a modular downhole tool having a measuring or testing section disposed in one tool collar and a modular power sub disposed in another tool collar. For example, during high temperature logging runs, which may expose the battery or any other component in the power sub to unacceptably high temperatures, the modular power sub may be removed from the tool and replaced with another modular power sub having a higher temperature rating, such as a turbine. Thus, the downhole tool may be equipped with any of a plurality of power subs having varying power outputs, thereby allowing the downhole tool to be configured with different electrical power configurations. An additional potential advantage provided by this configuration is that the measuring/testing section and the modular power sub of the downhole tool can be handled separately, thereby providing more compact collars (e.g. shorter than thirty five feet and/or lighter than four thousand five hundred pounds). Short collars are easier to transport to and from a drilling rig and easier to assemble to the BHA.
[0010] One embodiment introduced in the present disclosure provides an electrical power system comprising a support configured for interconnection within a subsurface drillstring, an electrical power unit coupled to the support, and a conductive link configured to distribute electrical power from the electrical power unit to at least one component coupled to the electrical power system within the subsurface drillstring. The support may comprise a drill collar and a central chassis internally coupled to the drill collar. The support may also comprise an annular space between the drill collar and the central chassis, wherein the annular space is configured to allow mud flow to or from the at least one component coupled to the electrical power system within the subsurface drillstring. The central chassis may comprise a first conductor, at least one power source, at least one electronics component, and a second conductor, wherein the at least one power source and the at least one electronics component are each coupled between the first and second conductors. The conductive link may be coupled, at least indirectly, to at least one of the first and second conductors. The conductive link may comprise at least one of the first and second conductors. One of the first and second conductors may comprise a pin conductor and the other of the first and second conductors may comprise a box conductor. The conductive link may comprise at least one multiple conductor member. For example, the conductive link may comprise a plurality of electrical conductors, including at least one first conductor configured for distributing high power and at least one second conductor configured for distributing communications. The plurality of electrical conductors may also include at least two first conductors configured for distributing high power and at least two second conductors configured for distributing communications.
[0011] The present disclosure also introduces a modular power system for a downhole tool, comprising a tool collar configured to operatively connect to a BHA, wherein the BHA comprises a plurality of BHA components; an electrical power source disposed in the tool collar and configured to provide electrical power to at least one of the plurality of BHA components; and a connector disposed between the electrical power source and one of the plurality of BHA components. The plurality of BHA components may include at least one drilling component, at least one telemetry component, at least one measurement-while-drilling (MWD) component, and/or at least one logging-while-drilling (LWD) component. The plurality of BHA components may not comprise any internal electrical power source and, thus, may only be powered by the electrical power source. The electrical power source may comprise an energy storage medium, including where none of the BHA components comprise an energy storage medium. The electrical power source may additionally or alternatively comprise an energy conversion device, including where none of the BHA components comprise an energy storage medium. The electrical power source may comprise an energy storage medium which is rechargeable downhole and/or at the surface.
[0012] The present disclosure also provides a modular drilling tool having a drill bit at and end thereof, comprising: a first collar including at least portions of a testing module; a second collar including at least portions of a telemetry module; and a third collar including an electrical power source operatively connected to the testing module; wherein removal of the third collar reduces a length of the tool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic view of drilling apparatus according to the prior art.
[0014] FIG. 2 is a schematic view of a bottom hole assembly (BHA) according to the prior art.
[0015] FIG. 3 is a schematic view of a BHA according to one or more aspects of the present disclosure.
[0016] FIG. 4 is a schematic view of a power sub according to one or more aspects of the present disclosure.
[0017] FIG. 5 is a schematic view of an electrical connector according to the prior art.
[0018] FIG. 6 is a schematic view of an electrical connector according to one or more aspects of the present disclosure.
[0019] FIG. 7 is a schematic view of an electrical connector according to one or more aspects of the present disclosure.
[0020] FIG. 8 is a schematic view of an electrical connector according to one or more aspects of the present disclosure.
[0021] FIG. 9 is a schematic view of a power sub according to one or more aspects of the present disclosure.
DETAILED DESCRIPTION
[0022] FIG. 3 is a schematic view showing aspects of the present disclosure. This system configuration includes a centralized power scheme where a modular power sub 30 is disposed in the assembly. With a power section no longer required in each tool, their complexity and length decreases significantly. This in turn moves all of the measurements taken by these tools closer together (e.g., reduced spacing between sources/sensors 32 ) and to the drill bit. The close proximity to the bit creates a major advantage in well trajectory decision making as the well profile can be more precisely controlled with the measurements closer to the bit. In addition to the centralized power, a multiple conductor, high power and communications bus 34 is disposed in the string. Multiple conductors are preferable to maximize both the power transmission and the telemetry data rate. Also, while the tools shown in FIG. 2 have a dedicated power source and hence may still be operative in case of a failure of the single conductor bus 22 , the bus 34 preferably provides redundant electrical paths between the modular power sub 30 and the tools in the BHA to minimize the impact of the failure of one of the paths in the bus 34 . Although aspects of the modular power sub 30 disclosed herein are shown powering the tools of a drill string BHA, one skilled in the art given the benefit of this disclosure will appreciate that the present disclosure is not limited solely to drilling applications.
[0023] FIG. 4 is a schematic view showing aspects of a modular power sub 30 of the present disclosure. A central chassis 36 resides inside a main drill collar 38 which withstands all of the drilling forces. The illustrated configuration allows mud flow within the annular space between the drill collar 38 and the chassis 36 . However, other configurations within the scope of the present disclosure may have the mud flow through a central channel (not shown) within the chassis 36 . Additionally, other aspects may be implemented with the chassis 36 offset from center of the collar 38 .
[0024] The chassis 36 may be comprised of four main components, such as an upper conductor 40 , a power unit/source 42 , electronics 44 , and a lower conductor 46 . The upper 40 and lower 46 conductors route power and communication to and from the power sub 30 .
[0025] The upper conductor 40 comprises a pin connector 48 and the lower conductor 46 comprises and a box connector 50 . It will be understood that aspects of the power sub 30 can be implemented with the pin and box connectors transposed (i.e., pin at lower position, box at upper position). FIG. 5 shows a conventional connector pair 60 . This connector has a single-contact 62 configuration with seals 64 . Although conventional connectors may be used, aspects of the present disclosure are not limited to any particular connector design. Furthermore, the connector may be implemented in the collar wall, as known in the art.
[0026] Turning to FIG. 6 , another aspect of a connector pair 70 of the present disclosure is shown. The connector pair 70 of FIG. 6 is configured with a mating pair of dual contacts 72 , 74 . Two or more contacts allow for efficient transmission of both power and communication. This connector pair maximizes contact length while minimizing the overall engagement length of the connector so as to easily fit within the envelope of a tapered drill collar thread connection. The short path between the connectors is also maximized and elastomeric seals 76 are used to isolate the connections. The radial arrangement of the smaller box socket comprising contacts 74 within the large pin could be expanded beyond two conductors as shown to three conductors and beyond. Any suitable materials may be used to implement the connector pairs of the present disclosure as known in the art.
[0027] FIG. 7 shows another connector pair 80 of the present disclosure. This aspect comprises multiple contacts 82 spaced axially on a single diameter separated by insulating seals 84 . FIG. 8 shows yet another connector pair 90 of the present disclosure. This aspect also comprises multiple contacts 92 spaced axially and separated by insulating seals 94 , but at differing diameters as to increase the short path without increasing the axial distance between conductors.
[0028] Returning to FIGS. 3 and 4 , the power source 42 section of the power sub 30 may be comprised of single or multiple power sources. These power sources can be divided into two types: energy conversion and energy storage. Energy conversion aspects include, but are not limited to, turbine power converting kinetic energy of the mud flow into electric power, vibrational energy generators, and piezo-electric power conversion. Energy storage aspects include, but are not limited to, batteries (rechargeable downhole or not), ultra-capacitors, fuel cells, and flywheel kinetic energy storage.
[0029] Batteries and rechargeable batteries offer a convenient power source for aspects of the present disclosure. Aspects may also be implemented using combinations of power sources. For example, an aspect may be configured for turbine power to provide power during mud flow while battery power is used to provide power with no flow present. The use of turbine or other energy conversion systems allows for aspects to be implemented wherein a battery or other energy storage device is charged downhole. Alternatively, such combinations could be used together to increase the power output of the power sub 30 .
[0030] In addition to providing power management of the power sources implemented in the power sub 30 , aspects of the electronics 44 section are configured to protect against spark and shock risk at the conductors during handling and connection with other tools. Indeed, while the tools shown in FIG. 2 only share power source based on energy conversion (i.e., a turbine) that is inactive during the handling or connection with other tool, the power sub 30 preferably includes a power source based on energy storage (e.g., a battery) that is usually charged before it arrives at the drilling rig. Hence, it may be advantageous to implement one or more safety switches in the power sub 30 , as further detailed below. Other functions of the electronics 44 may include sensing, recording and transmitting power system status and diagnostics, both in real time via telemetry means and following an operation from recorded memory. Optional sensors may also be implemented in the electronics 44 section if desired (e.g., annular or stand pipe pressure sensors).
[0031] A tiered approach to safety is preferred, as well as the use of automated safety logic. Aspects of the power sub 30 may be implemented with a safety switch. One aspect is configured with the safety switch in the form of a hall effect sensor energized by a magnet and inserted into a read-out-port (ROP) disposed on the sub 30 (See item 45 in FIG. 4 ) and operable from an exterior of the power sub 30 (e.g., an exterior of the collar 38 ). In this embodiment, when the magnet is inserted into the ROP 45 , the power source 42 is electrically disconnected or de-coupled from the conductors 40 , 50 at either end of the tool. It will be understood by one skilled in the art that other means may be used to disconnect the power source 42 . For example, an alternative to using a hall effect switch is a mechanical switch that is closed when the power sub 30 is linked into the tools in the assembly (not shown).
[0032] In operations, the magnet is removed at the rig, for example once the BHA is assembled, thereby permitting the connection of the power source 42 to one or both connectors 40 and 50 . However further control of one or more of the power sources 42 may be achieved, if desired. Once in service downhole, the power source 42 can be switched on or coupled via downlink commands through telemetry means (or direct control via a wired drill pipe system). Such automated switch logic can also be configured for operation when the central chassis 36 is put into the BHA. Safety interlocks can be included for automatic coupling of the power source 42 when mud flow is confirmed. U.S. Pat. No. 6,649,906 (assigned to the present assignee and entirely incorporated herein by reference) describes safety interlock configurations that may be implemented with aspects of the present disclosure. The power source 42 can then remain coupled unless a safety interlock is violated (e.g., a voltage or current limit violation, or a predetermined timeout without mud flow) or a downlink telemetry decoupling command is given.
[0033] The electronics 44 of the power sub 30 may be configured to vary the output voltage delivered through the upper 40 and/or lower 46 conductors as needed. The electronics 44 can be implemented with appropriate circuitry to allow on-site programming of the output voltage, increasing the flexibility of the system. Additionally, the electronics 44 can also be used for the purpose of recharging a rechargeable power source 42 .
[0034] Aspects of the present disclosure may be implemented using multiple power subs 30 in a single assembly. The subs 30 could be used in parallel to increase the power capability of the system or used sequentially to increase the run life (e.g., in the case of an energy storage device). It should be appreciated that, in the configuration shown in FIG. 2 , no electrical coupling between two power sources is provided. In contrast, when multiple power subs 30 are coupled to the bus 34 in the BHA, for example a battery and a turbine, it may be advantageous to implement power management systems between the multiples power subs. Thus, the electronics 44 in each sub 30 can be configured to prevent inadvertent charging or discharging of the power source 42 when multiple subs are used in combination.
[0035] Aspects of the present disclosure may also be configured with a retrievable power source 42 such that the source (e.g., a battery) could be replaced or initially inserted from the surface, with the BHA in position downhole. One such aspect can be implemented with the chassis 36 and collar 38 incorporating a latching mechanism (See item 49 in FIG. 4 ) and a modified connector 48 at the upper end thereof. The latching mechanism 49 removably connects the retrievable chassis 36 to the drill collar 38 , while allowing for mud flow through the tubular. The modified upper connector 48 can be adapted for connection to a wireline, slickline, or other retrieval mechanisms as known in the art for retrieval of the unit to the surface. The retrievable chassis 36 may also be deployed into the downhole tool or subsurface assembly using a tractor, mud flow, gravity or other conveyance means. The retrievable chassis 36 is then secured in place using the latching mechanism 49 . Other retrievable configurations may be devised to implement aspects of the present disclosure. U.S. Pat. No. 6,577,244 and U.S. Patent Publication No. 20060260805 (both assigned to the present assignee and entirely incorporated herein by reference) describe retrievable tool configurations that may be implemented with aspects of the present disclosure.
[0036] FIG. 9 is a schematic view of a power sub 130 according to one or more aspects of the present disclosure. This system configuration includes a centralized power scheme where the modular power sub 130 is disposed in the assembly. One or more aspects of the power sub 130 are or may be substantially similar to corresponding aspects of the power sub 30 described above and shown in other figures. For example, the power sub 130 may include a multiple conductor, high power and communications bus which may be substantially similar in function to the bus 34 described above. The bus may provide redundant electrical paths between the modular power sub 130 and the tools in the BHA to minimize the impact of the failure of one of the paths in the bus. Although aspects of the modular power sub 130 disclosed herein are shown powering the tools of a drill string BHA, one skilled in the art given the benefit of this disclosure will appreciate that the present disclosure is not limited solely to drilling applications.
[0037] The modular power sub 130 shown in FIG. 9 may also include a central chassis similar in function to the chassis 36 described above, coupled internally to a main drill collar 138 in a manner which allows mud flow within the annular space between the drill collar 138 and the chassis. However, other configurations within the scope of the present disclosure may have the mud flow through a central channel (not shown) within the chassis. Additionally, other aspects may be implemented with the chassis offset from center of the collar 138 .
[0038] The chassis may be comprised of four main components, such as an upper conductor module 140 , a plurality of rechargeable battery modules 142 , an energy conversion module 143 , an electronics module 144 , and a lower conductor module 146 . It is worth noting that the top-to-bottom sequence of these modules is not limited to the embodiment shown in FIG. 9 . For example, the electronics module 144 may be positioned above the battery modules 142 and/or below the energy conversion module 143 , among other embodiments within the scope of the present disclosure.
[0039] The upper 140 and lower 146 conductor modules route power and communication to and from the power sub 130 . The upper conductor module 140 may comprise a pin connector and the lower conductor module 146 may comprise a box connector as described with regard to embodiments discussed above. It will be understood that aspects of the power sub 130 can be implemented with the pin and box connectors transposed (i.e., pin at lower position, box at upper position). Moreover, the particular connector pair employed by the upper 140 and lower 146 conductor modules may be any of those described elsewhere herein, conventional, or otherwise.
[0040] The power section of the power sub 130 comprises multiple power sources/modules. These power sources can be divided into two types: energy conversion and energy storage. Energy conversion aspects include, but are not limited to, turbine power converting kinetic energy of the mud flow into electric power, vibrational energy generators, and piezo-electric power conversion. In the embodiment illustrated in FIG. 9 , for example, the energy conversion module 143 includes a turbine 143 a configured to be driven by mud flow and cooperate with an alternator 143 b to convert rotational kinetic energy into electric power. Energy storage aspects include, but are not limited to, batteries (rechargeable downhole or not), ultra-capacitors, fuel cells, and flywheel kinetic energy storage. In the embodiment illustrated in FIG. 9 , for example, such energy storage is accomplished via the plurality of rechargeable battery modules 142 which are electrically coupled (at least indirectly) to the energy conversion module 143 , such that the rechargeable battery modules 142 may store the energy generated by the energy conversion module 143 .
[0041] The power sub 130 may also include a safety switch 145 . The safety switch may be or comprise a hall effect sensor energized by a magnet and inserted into a read-out-port (ROP) disposed on the power sub 130 and operable from an exterior of the power sub 130 (e.g., an exterior of the collar 138 ). For example, when the magnet is inserted into the ROP 145 , the battery modules 142 and/or energy conversion module 143 are electrically disconnected or de-coupled from the conductor modules 140 , 150 at either end of the tool. It will be understood by one skilled in the art that other means may be used to disconnect the power sources 142 and/or 143 . For example, an alternative to using a hall effect switch is a mechanical switch that is closed when the power sub 130 is linked into the tools in the assembly (not shown).
[0042] The electronics 144 of the power sub 130 may be substantially similar, at least in function, to those describe above, such as being configured to vary the output voltage delivered through the upper 40 and/or lower 46 conductor modules as needed. The electronics 144 can be implemented with appropriate circuitry to allow on-site programming of the output voltage, increasing the flexibility of the system. Additionally, the electronics 144 can also be used in conjunction with recharging of the rechargeable battery modules 142 . For example, the electronics 144 may be configured to prevent inadvertent charging or discharging of the battery modules 142 and/or energy conversion module 143 , including when multiple subs are used in combination.
[0043] The sub 130 may also be configured with retrievable battery modules 142 such that they may be replaced or initially inserted from the surface, with the BHA in position downhole. One such aspect can be implemented with the chassis and collar 138 incorporating a latching mechanism (such as item 49 shown in FIG. 4 ) and a modified connector at the upper end thereof. The latching mechanism may removably connect the retrievable chassis to the drill collar 138 , while allowing for mud flow through the tubular. The modified upper connector can be adapted for connection to a wireline, slickline, or other retrieval mechanisms as known in the art for retrieval of the unit to the surface. The retrievable chassis may also be deployed into the downhole tool or subsurface assembly using a tractor, mud flow, gravity or other conveyance means. The retrievable chassis may then be secured in place using the latching mechanism. Other retrievable configurations may be devised to implement aspects of the present disclosure. U.S. Pat. No. 6,577,244 and U.S. Patent Publication No. 20060260805 describe retrievable tool configurations that may be implemented with aspects of the present disclosure.
[0044] It will be appreciated by one skilled in the art that various tool configurations can be implemented using the modular power source techniques disclosed herein. For example, it will be appreciated that the disclosed power sub configurations can be implemented to include conventional sources and sensors to perform a variety of subsurface measurements as known in the art. Though not shown in full detail for clarity of illustration, the disclosed aspects can be implemented with conventional electronics, hardware, circuitry, housings and materials as known in the art. For example, embodiments can be implemented using composite materials to form the chassis and/or housing tubular as known in the art. U.S. Pat. Nos. 6,084,052 and 6,300,762 (both assigned to the present assignee and entirely incorporated herein by reference) describe composite-based tools and tubular configurations that may be implemented with aspects of the present disclosure. It will also be appreciated that aspects of the present disclosure may be used for any subsurface applications requiring a local power source including, but not limited to, LWD/MWD, LWT, run-in tools, production tubing, casing, and underwater applications. For the purposes of this disclosure it will be clearly understood that the word “comprising” means “including but not limited to” and that the word “comprises” has a corresponding meaning.
|
An electrical power system comprising a support configured for interconnection within a subsurface drillstring, an electrical power unit coupled to the support, and a conductive link configured to distribute electrical power from the electrical power unit to at least one component coupled to the electrical power system within the subsurface drillstring.
| 4
|
FIELD
This application relates to blade retention in gas turbine engines and the like.
BACKGROUND
Typically, a rotor assembly for an aircraft engine has a rotor disk and one or more arrays of rotor blades. The rotor blades extend outwardly into a working medium flow path such as air. The rotor blades engage the outer periphery or rim region of the rotor disk. The rim region of the rotor disk is defined generally by axially oriented slots that receive the roots of the rotor blades.
The working medium gases exert a tangential force and an axial force on the blades as the gases flow through the rotor assembly. The axial force on the rotor blades urges the rotor blade bases axially forward relative to the movement of aircraft carrying the engine and out of the axially oriented slots. Lock means are provided to lock the rotor blades against this forward axial movement. These locks add to the rotational mass of the rotor assembly and must be carried by the rotor disk.
If a rotor blade suffers a foreign object strike, however, the rotor blade tends to rotate about the points where the foreign object strikes sending the rotor blade's root forward relative to the movement of aircraft within the rotor disk. For this reason, to protect the integrity of the rotor and the rest of the engine, lock means are also provided to lock the rotor blades from moving axially forward.
SUMMARY OF THE INVENTION
An exemplary embodiment of a lock for constraining blades in a hub includes a flexible ring for constraining the blades from moving axially forward in the hub, a finger attached to the hub for preventing the ring from rotating relative to the hub and whereby the ring flexes about at least a partial circumference thereof if urged axially by the blades.
A further exemplary method for mounting a blade on a hub includes inserting a blade root into a slot in the hub, placing a flexible ring against the blade root, placing a finger within the ring to prevent its rotation and wherein the ring flexes axially about at least a partial circumference thereof if urged by the blade root.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an aircraft hub, a lock ring and an anti-rotation ring.
FIG. 2 is a perspective exploded view of the aircraft hub, a lock ring and an anti-rotation ring of FIG. 1 .
FIG. 3 is a schematic view of the aircraft hub, a lock ring and an anti-rotation ring of FIG. 1 . of FIG. 1 .
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1-3 , a hub 10 for an aircraft engine (not shown) or the like, with a lock ring 15 and an anti-rotation ring 20 is shown. The hub 10 has a plurality of splines 25 for attaching to a shaft (not shown). The hub has a plurality of mounts 30 , such as slots, for holding a fan blade root 35 . The mounts 30 have a trapezoidal cross section 40 that runs from the front 45 of the hub towards a back 50 of the hub. The trapezoidal cross section securely traps the fan blade root 35 therein. Other shapes of such mounts are contemplated herein.
A circular ring mount 55 is disposed about a front 45 of the hub. The ring mount 55 has a plurality of outer diameter tabs 60 that are separated by gaps 65 . The hub also has a plurality of inner diameter tabs 70 extending radially inwardly towards the spline 25 . Each inner diameter tab 70 at an end 75 thereof has an axial flange 80 extending outwardly therefrom. The inner diameter tab also has a hole 85 through which a bolt 90 is designed to extend.
Referring to FIGS. 2 and 3 , each lock ring 15 has an inner surface 95 , an outer surface 100 , a front edge 105 , a back edge 110 , and internal diameter tabs 115 extending around the inner surface 95 of the lock ring.
The anti-rotation ring 20 has a circular body 120 , fingers 125 that extend towards the back end 50 of the hub, inner diameter tabs 130 that depend inwardly towards the splines and an axial flange 135 extending radially towards a front of the hub 45 . The axial flange 135 sits upon and cooperates with axial flange 80 of the hub. The inner diameter tabs 130 have a hole 140 extending therethrough.
During assembly, the lock ring 15 inner diameter tabs 115 are aligned with and disposed within the gaps 65 of the hub 10 and pushed axially towards the mounts 35 into the circular ring mount 55 . Once the inner diameter tabs 115 clear the gaps 65 , the lock ring is rotated as shown in FIG. 3 so that the lock ring inner diameter tabs 115 are disposed behind the hub 10 outer diameter tabs 60 . Bolts 90 are threaded through holes 140 in the anti-rotation ring 20 and holes 85 in the hub 10 after which nuts 145 (see FIG. 3 ) are threaded on the bolts and secured thereupon. In this arrangement, the axial flange 135 and the inner diameter tabs 130 of the anti-rotation ring 20 are seated against the inner diameter tabs 70 and axial flanges 80 of the hub 10 . The fingers 125 extend through the gaps 65 and prohibit the lock ring from rotating relative to the hub 10 .
If there is foreign object damage or bird strike against the blade 155 (see FIG. 3 ), the strike or damage will cause a moment of inertia to move the blade root forward towards the front end 50 of the hub 10 . Because the lock ring 15 is designed to flex torsionally behind the outer diameter tabs 60 of the hub 10 , impact of the blade strike will be shared along a circumference of the lock ring 15 such that the anti-rotation key fingers do not shear and the blade lock does not shear and the blade root is retained within the hub 10 .
By allowing movement, such as deflection, in the lock ring 15 about a circumference thereof, split rings of the prior art (not shown) may be eliminated and the weight of the lock ring will be minimized to allow a more efficient arrangement.
Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
|
A lock for constraining blades in a hub includes a flexible ring for constraining the blades from moving axially in the hub, a finger attached to the hub for preventing the ring from rotating relative to the hub and whereby the ring flexes about at least a partial circumference thereof if urged axially by the blades.
| 8
|
This application claims the benefit of Provisional Application No. 60/286,473 filed Apr. 25, 2001.
TECHNICAL FIELD
This invention relates generally to movable barrier operators and more particularly to obstacle detection.
BACKGROUND
Movable barrier operators are known in the art. Such operators, including garage door operators, are often provided with a mechanism to detect when an obstacle lies in the path of the movable barrier. Upon sensing such an obstacle, movement of the movable barrier can be altered to avoid damage or injury to the obstacle and/or the movable barrier.
In some systems, a force limit (or force sensitivity) can be manually set. When this value is exceeded during movement of the movable barrier, as will typically occur when the movable barrier contacts an obstacle, an appropriate response can be effected. For example, the direction of travel of the movable barrier can be reversed to move the movable barrier away from the obstacle. In other systems, the speed of door travel is monitored. If the speed slows or stops, the operator determines that the movable barrier has contacted an obstacle and again the movable barrier can be stopped or its movement reversed.
One problem with such systems derives from the fact that the amount of force required to move a movable barrier over its entire travel limit may vary from place to place. Variations can also exist in a given place between closing and opening the movable barrier. In addition, mechanical noise due to sticking of the movable barrier can also contribute detectable artifacts that can simulate rapid force changes that can in turn cause an unwanted operator response.
Some prior art systems seek to remedy such problems by adjusting force sensitivity to make the operator less sensitive to such conditions. Unfortunately, reducing sensitivity in this way will also often make the operator less sensitive to detecting a genuine obstacle impact.
Other systems use so-called force profiling. Historical force information is stored in a force table and possibly updated from time to time to account for changes over time. Unfortunately, these systems, too, are sometimes subject to false triggering due at least in part to measurement anomalies during the operation of the movable barrier.
BRIEF DESCRIPTION OF THE DRAWINGS
The above needs are at least partially met through provision of the method and apparatus for facilitating control of a movable barrier operator described in the following detailed description, particularly when studied in conjunction with the drawings, wherein:
FIG. 1 comprises a block diagram as configured in accordance with an embodiment of the invention;
FIG. 2 comprises a flow diagram as configured in accordance with an embodiment of the invention;
FIG. 3 comprises a flow diagram as configured in accordance with an embodiment of the invention;
FIG. 4 comprises a flow diagram as configured in accordance with an embodiment of the invention; and
FIG. 5 comprises a flow diagram as configured in accordance with another embodiment of the invention.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are typically not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.
DETAILED DESCRIPTION
Generally speaking, during movement of a movable barrier from a first position to a second position by a movable barrier operator, the operator repeatedly senses a parameter representing the forces applied to the movable barrier during a first interval of time and determines at least one value that represents the sensed forces on the movable barrier over the interval of time. During a subsequent interval of time, which subsequent interval is later than the first interval of time but still during the same movement of the movable barrier from the first position to the second position, this sensed value is used to determine a threshold value. In one embodiment, the representative value is divided by a predetermined scaling value and is then multiplied by an adjustment value to derive the threshold value. In one embodiment, the adjustment value comprises at least one of a force adjustment setting and a noise level adjustment value. If desired, the force adjustment value can be multiplied by the noise level adjustment value to provide the adjustment value. The forces applied to the barrier may be sensed somewhat directly by use of a force sensing device such as a piezoelectric strain measuring unit or such forces can be represented by the current applied to the motor or the speed at which the motor or the barrier are moved. Other such devices for representing applied forces are known in the art. In the subsequently described embodiments the barrier speed as represented by motor speed is used to represent forces applied to the barrier.
Pursuant to these various embodiments, during movement of a movable barrier from a first position to a second position by a movable barrier operator, the operator repeatedly senses present speed of the movable barrier during a first interval of time and determines at least one representative value as corresponds to the speed of the movable barrier over that interval of time. (In a preferred embodiment, this interval of time is without fixed duration. Instead, the interval is bounded by the amount of time required to accommodate a fixed number of sequential position measurements.) In one embodiment, the at least one representative value comprises a median value of speed over this interval of time. During a subsequent interval of time, which subsequent interval is later than the first interval of time but still during the same movement of the movable barrier from the first position to the second position, this representative value is used to determine a threshold value. In one embodiment, the representative value is divided by a predetermined scaling value and is then multiplied by an adjustment value to derive the threshold value. In one embodiment, the adjustment value comprises at least one of a force adjustment setting and a noise level adjustment value. If desired, the force adjustment value can be multiplied by the noise level adjustment value to provide the adjustment value.
During that subsequent interval of time, a first value that corresponds to the present speed of the movable barrier is compared with the threshold value. In one embodiment, the first value comprises the absolute value of the present speed less the representative value determined above. This first value is then compared against the threshold value. When the first value is within a predetermined range of values with respect to the threshold value, the operator then takes at least one predetermined action with respect to subsequent movement of the movable barrier (for example, movement of the movable barrier can be stopped or reversed). In one embodiment, the predetermined range of values includes values that are larger than the threshold value, such that the predetermined action will be taken when the first value exceeds the threshold value.
In one embodiment, to aid in preventing false triggering of the predetermined response, a plurality of such comparative results can be required before initiating the predetermined action.
Referring now to FIG. 1, a movable barrier system 10 includes, in this embodiment, a movable barrier operator 11 that comprises a programmable platform. The movable barrier operator 11 couples to a motor 12 which in turn is coupled to a movable barrier (not shown) via an appropriate drive mechanism (not shown) as well understood in the art. A sensor 13 provides speed information regarding the motor 12 to the movable barrier operator 11 . Such a sensor 13 may be, for example, an optical interrupter that provides a signal to the movable barrier operator 11 each time an output shaft of the motor 12 rotates a predetermined amount. If desired, one or more force setting controls 14 and 15 can also be provided (for example, to allow manual adjustment of a force setting when closing, opening, or both). All of the above components, both individually and as combined, are well understood in the art. Therefore, for the sake of brevity and the preservation of focus, additional description will not be provided here.
So configured, the movable barrier operator 11 can cause selective movement of a movable barrier by control of the motor 12 . This includes moving the movable barrier from an open position to a closed position and the reverse thereof. Also, as already indicated, the movable barrier operator 11 can monitor the speed of the motor 12 and hence the corresponding speed of the movable barrier. Also as already indicated, force settings can be manually modified by a user (in this embodiment, such controls, when present, are presumed to offer a range of adjustment from one to sixteen, with sixteen representing maximum sensitivity to force and one representing the least sensitivity to force). The movable barrier operator 11 comprises a programmable platform that is programmed in an ordinary fashion to function as a movable barrier operator. In addition, and referring now to FIG. 2, the movable barrier operator 11 is programmed to respond in an interrupt fashion 20 upon receipt of a signal from the sensor 13 . As a result, the operator 11 will receive such an interrupt each time the movable barrier moves a predetermined distance. Upon receiving such an indication the operator 11 then reads 21 an internal timer and calculates 22 an instantaneous period P (or RPM value) for the motor 12 , which value of course corresponds to movement of the movable barrier (such a value is easily calculated by determining how much time is required to incrementally move a predetermined distance as corresponds to the sensor 13 mechanism as is well understood in the art). This value P is then stored 23 . The operator 11 then determines 24 whether this present speed value P exceeds a previously stored value P-HI (if any) that constitutes a highest previous speed value during the present interval or window of review. If true, the operator 11 writes 25 the present speed value P into memory as the new highest speed value for the present interval. The operator 11 also determines 26 when a present speed value P is less than a lowest previous speed value P-LO as identified and stored for the present interval. Again when true, the operator 11 writes 27 the present speed value P into memory as the new lowest speed value for the present interval. Once the operator 11 determines 28 that a predetermined number of readings have been taken in this fashion, the operator 11 calculates 29 a median value P-MEDIAN for the interval. In a preferred embodiment, the median value is calculated by adding the highest speed value P-HI with the lowest speed value P-LO and then dividing by two. P-MEDIAN as calculated is then stored 30 and P-HI and P-LO are cleared to allow re-identification during a subsequent interval.
So configured, the operator 11 can calculate a value that is representative of speed of the movable barrier over various intervals of time. In particular, a value representing a median value for speed over each interval can be so calculated.
Referring now to FIG. 3, when the operator 11 begins 31 a new interval, optional force settings as correspond to force setting controls 14 and 15 can be read 32 . The median speed value P-MEDIAN as determined in the previous interval is then read 33 and utilized to determine 34 a threshold value T. In one embodiment, this threshold value T can be calculated as follows:
T= ( P - MEDIAN/ 256)( FS+NA ) (1)
where FS=a force setting of from 1 to 16 as manually set via a corresponding force setting control 14 or 15 as understood in the art and NA=a noise adjustment value that can be used to desensitize the calculation of the threshold value T somewhat from noise in the system. In a preferred embodiment, this threshold value T is calculated once and used during an entire interval as described below in more detail. Again, it should be noted that the interval during which data is gathered to allow calculation of the threshold value T and the interval during which the threshold value T is used both occur during the same movement of the movable barrier from a first position to a second position (such as when moving from an open to a closed position or from a closed to an open position).
During each interval, as described, the operator 11 calculates a median value P-MEDIAN for the preceding interval as well as a threshold value T that also derives from preceding interval data. Referring now to FIG. 4, with each new period value as sensed 40 by the operator 11 during the next subsequent interval, the operator reads 41 the new period P (as calculated pursuant to the process described above with respect to FIG. 2 ). The operator 11 also reads 42 the P-MEDIAN value as calculated for the previous interval and reads 43 the corresponding threshold value T. In this embodiment the operator 11 then determines 44 a test value TV by taking the absolute value of the present speed value P less the P-MEDIAN median speed value for the preceding interval. This test value TV is then compared with the threshold value T. In this embodiment, the operator 11 determines whether the test value TV is greater than the threshold value T.
The operator 11 determines 46 whether to react to the present speed value as a function of the comparison of the test value TV to the threshold value T. In particular, when the test value TV exceeds the threshold value T, the operator implements 47 an appropriate corresponding action.
If the operator 11 responds immediately when the test value TV first exceeds the threshold value T, however, the operator 11 may stop or reverse movement of the movable barrier in error. With reference to FIG. 5, in this embodiment, upon determining 46 that a given present speed value P is such that the test value TV exceeds the threshold value T, the operator 11 can increment 51 a count C and then determine 52 whether this count C exceeds a predetermined value X (such as, for example, “10”). If not, the operator 11 simply carries on in an ordinary fashion while continuing to monitor present speed of the motor/movable barrier. Once the count C has been met, however, the operator 11 then implements 47 a responsive action as before. It should also be noted that each time the operator 11 determines that a present given speed value does not correspond to a situation where the test value TV exceeds the threshold value T, the count C is cleared 53 . So configured, the operator 11 can still safely react to an actual obstacle in sufficient time while significantly avoiding false triggering of an obstacle-detected response.
Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention, and that such modifications, alterations, and combinations are to be viewed as being within the ambit of the inventive concept.
This application includes a computer code listing which is entitled
“S:\Shared\CDO\Lgo-Rjo\RJO-Study\Code\Final0301.S”
attached hereto on pages A1-A52.
|
A movable barrier operator ( 11 ) receives movement sensing signals from a sensor ( 13 ) and calculates corresponding speed of movement of a movable barrier. Such speed measurements lead to development of a median speed value over a monitoring window. The median speed value is used in a subsequent monitoring window to facilitate determining when speed of movement for the movable barrier has slowed in a way that likely corresponds to the movable barrier having encountered an obstacle.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application Ser. No. 10/662,366 filed Sep. 16, 2003, and the disclosure of said earlier application is fully incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to apparatus for tensioning shaft-mounted helical springs, and in particular for tensioning shaft-mounted torsion springs of overhead doors.
BACKGROUND OF THE INVENTION
[0003] Sectional overhead doors for residential and commercial garages typically have a number of hinged horizontal sections with rollers at each end that run inside tracks extending vertically on each side of the door opening. The tracks continue either vertically or, perhaps most commonly, horizontally inward above the door opening to accommodate the door when in its open position. These doors commonly incorporate a counterweighting system to reduce the effective door weight that must be lifted by a manual or motorized door-opening mechanism.
[0004] The components of a typical counterweighting system include an elongate round shaft with a pulley at each end, and at least one helical torsion spring mounted generally concentrically on the shaft. The shaft is rotatably mounted to the building structure above and parallel to the door opening. Each pulley has a door-lifting cable attached to the door at a selected point, typically near the bottom of the door. One end of the spring is non-rotatably fixed to the building structure, and the other end is fixed to a spring cone which in turn is lockably mounted onto the shaft (typically by means of set screws). The spring may be tensioned by rotating the spring cone around the shaft and then locking the spring cone on the shaft. The tensioned spring exerts a rotational force on the shaft, inducing tension forces in the cables, which in turn exert upward forces on the door. These upward forces effectively counteract and reduce the weight that needs to be lifted when operating the door.
[0005] There are many known types of spring cones, most of which incorporate a number of radial sockets (typically four) into which steel winding rods can be inserted for purposes of winding the spring cone around the shaft to tension the spring. With the spring cone loose on the shaft, a first rod is inserted into one socket and manual force is applied to the rod to rotate the spring cone and one end of the spring a partial turn, thus increasing spring tension. With the first rod being firmly held (to restrain spring tension), a second rod is inserted into another socket and used to turn the cone further. With the second rod being firmly held, the first rod may be withdrawn and moved to a new socket. This alternating process is continued until a desired spring tension has been achieved, whereupon the spring cone is tightened onto the shaft and the rods are removed from the sockets.
[0006] This well-known procedure is effective but potentially dangerous. If the rods are accidentally let go of while the spring cone is loose on the shaft, the tensioned spring will quickly unwind, causing the spring cone to spin on the shaft. If one or both rods are still engaged in spring cone sockets, they will spin rapidly with the spring cone and thus may injure a person standing too close. In fact, the rods may even fly out of the spring cone and thus become dangerous projectiles that can seriously injure or even kill a bystander. The danger inherent in such situations is greater for larger and heavier doors, which typically have heavier springs that store greater potential energy when tensioned.
[0007] These risks are particularly great when spring tensioning is being attempted by a single worker. Muscle fatigue and momentary inattention or distraction are only two factors that could cause the worker to lose hold of the winding rods. In view of these concerns, it is less dangerous if the spring tensioning procedure is performed by two workers, each operating only one winding rod. Then if one worker becomes unexpectedly tired or inattentive and loses control of one rod, the other worker will in most cases be holding the other rod safely, and preventing the spring from unwinding. An obvious disadvantage of this safer alternative procedure, however, is that the need for two workers results in higher cost for the spring tensioning operation.
[0008] For the foregoing reasons, it is desirable to have spring tensioning methods and means that do not use loose winding rods that can cause injury in case of inadvertent and uncontrolled unwinding of a tensioned spring, and, further, that can be safely by only one worker. The prior art discloses a number of attempts to address this problem. U.S. Pat. No. 2,718,282 (Davis), discloses spring tensioning apparatus having a splined cylindrical member with a longitudinal slot to permit mounting of the member over a spring shaft. The slot is then closed off using a secondary member that slides into longitudinal keyways in the cylindrical member on either side of the slot. The secondary member is also splined so as to create an effectively continuous splined perimeter around the cylindrical member when the secondary member has been positioned in the slot. The cylindrical member has means for connecting to a spring cone so that the spring cone will rotate when the cylindrical member is rotated. Also provided is a pair of pawl-equipped ratchet levers, each having a cylindrical inner surface and an opening to allow positioning over the shaft. The levers are placed over the shaft and slid over the splined cylindrical member, whereupon they may be operated in alternating fashion, with the pawls of the levers engaging the splines of the cylindrical member and causing it to rotate, thus rotating the spring cone and tightening the spring. Because the shaft openings in the levers are smaller than the diameter of the cylindrical member, the levers cannot come free of the cylindrical member without sliding them laterally off of the cylindrical member.
[0009] Although being a useful device, the Davis apparatus has several disadvantages. For example, it requires precise machining for splining of the cylindrical and secondary members, as well as for the keyways in the cylindrical member and the corresponding keys of the secondary member. Indeed, if the keyways are not machined to close tolerances, the secondary member will either fit too tightly (thus being difficult to install and remove) or it will be too loose (thus being prone to sliding out of the cylindrical member, making the apparatus inoperable. Even when these parts have been machined to provide an optimal fit, their mating surfaces can become damaged or covered with grime, paint, or other contaminants, in each case making insertion and/or removal of the secondary member difficult or impossible. Furthermore, the secondary member is of necessity a loose component that could be accidentally lost, again making the apparatus unusable.
[0010] U.S. Pat. No. 3,651,719 (Wessel) discloses another spring tensioning apparatus that operates on the ratchet principle. This apparatus features an hinged split collar assembly releasably mountable around a spring cone, with a rigid pin that goes into one of the spring cone sockets so that rotation of the collar will cause rotation of the spring cone. The split collar has rounded ratchet teeth around its perimeter, the teeth extending across the full width of the inner collar. The apparatus includes a pair of pawled ratchet handles, each with a hinged split collar section approximately half the width of the toothed inner collar. The Wessel apparatus is operated by opening the inner collar and mounting it to the spring cone, closing the inner collar and locking its hinged sections with an anchor pin, opening the ratchet handle collars of the ratchet handles and placing them over the inner collar, closing the ratchet handle collars and locking their hinged sections together with anchor pins, and, finally, operating the handles in alternating fashion to tighten the spring.
[0011] The Wessel apparatus also has disadvantages and drawbacks. Its installation requires the use of three anchor pins, and the loss of even one of these loose components may make the apparatus unusable. It also has several hinges that are prone to wear and breakage that could make efficient use of the apparatus difficult or impossible. Furthermore, installation of the Wessel apparatus on the spring shaft involves a number of steps before it is ready to operate, and these steps must also be performed in reverse in order to remove the apparatus from the shaft after the spring has been tensioned. This comparatively labour-intensive procedure increases the cost of spring tensioning.
[0012] Another ratchet-type spring tensioning device is found in U.S. Pat. No. 5,605,079 (Way). This apparatus has a split housing, which is separable for installation onto the shaft and the spring cone, with a bore for receiving the shaft and a number of pins for engaging holes in the winding cone. A split sprocket is integrally mounted to the housing and an annular groove on each side of the sprocket receives a ratchet tool. The ratchet tools are locked into the groove using bolts to prevent disengagement, and are operated in alternating fashion to rotate the sprocket, thus rotating the spring cone to adjust the tension in the spring. Disadvantages of this system include the number of loose components and the higher degree of assembly and disassembly required (i.e. assembly of the split housing and sprocket, attachment of the ratchet tools, and the corresponding disassembly once the adjustment is completed).
[0013] In view of the disadvantages of the prior art devices described above, there is a need for an improved apparatus for adjusting the tension of a helically wound torsion spring that has minimal or no small loose components prone to being misplaced, that has minimal hinged components prone to wear and disrepair, and that is simple to attach to and remove from a spring shaft, while being safely operable by a single worker. The present invention is directed to these needs.
BRIEF SUMMARY OF THE INVENTION
[0014] In general terms, the invention is an apparatus for safely tensioning a torsion spring, without need for spring cone tightening rods that may pose an injury hazard in the event of an inadvertent release of spring tension during the tensioning operation. The apparatus features a central ratchet assembly with cogged ratchet wheels at each end, slotted to allow the assembly to be placed over the spring shaft adjacent to the spring cone. The ratchet assembly includes sub-apparatus connectable to the spring cone so that the spring cone (and therefore the spring) will rotate when the ratchet assembly is rotated. The slots in the ratchet wheels are closed by cogged bridging elements to create a continuously cogged perimeter around the ratchet wheels. The apparatus includes a pair of pawl-equipped operating levers that may be positioned over the ratchet wheels so that the pawls can engage the ratchet wheel cogs. The levers may then be operated in alternating fashion to rotate the ratchet assembly, thus tensioning the spring.
[0015] Accordingly, in one aspect the present invention is an apparatus for tensioning a helical spring mounted generally concentrically on an elongate round shaft having a shaft diameter, said spring having a first end fixed to a building support and a second end anchored to a spring cone lockably mounted on the shaft, said apparatus comprising:
(a) a ratchet wheel assembly comprising:
a.1 a trunnion having a substantially semi-cylindrical inner surface with a diameter slightly greater than the shaft diameter, and having a concentrically semi-cylindrical outer surface defining an open side; and a.2 a pair of primary ratchet wheels, each having a centroidal opening, plus a radial slot contiguous with the centroidal opening and having two slot edges, said radial slot extending radially from the centroidal opening to the wheel's perimeter so as to intersect with and define a gap in said perimeter; wherein: a.3 the centroidal opening of each primary ratchet wheel is large enough to allow the shaft to be disposed therewithin, and concentrically with the primary ratchet wheel; a.4 the width of each radial slot is at least slightly greater than the shaft diameter; a.5 the perimeter of each primary ratchet wheel defines a continuous plurality of uniformly-spaced cogs between the edges of the primary ratchet wheel's perimeter gap; and a.6 the primary ratchet wheels are spaced apart and coaxially mounted to the trunnion with their radial slots aligned with the open side of the trunnion, such that the ratchet wheel assembly can be positioned substantially coaxially over the shaft;
(b) a pair of bridging elements, each bridging element being associated with a corresponding one of the primary ratchet wheels; each bridging element having an arcuate-edged section defining a plurality of cogs configured and spaced to match the cogs of the corresponding primary ratchet wheel; wherein each bridging element is selectively operable between:
b.1 an open position, in which the arcuate-edged section is substantially clear of the perimeter gap and radial slot of the corresponding primary ratchet wheel so as to permit positioning of the ratchet wheel assembly coaxially over the shaft; and b.2 an engaged position, in which the arcuate-edged section bridges the perimeter gap of the bridging element's corresponding primary ratchet wheel such that the cogs of the bridging element and the corresponding primary ratchet wheel combine to form a continuous and uniformly-spaced series of cogs;
(c) locking means, for releasably locking the bridging elements in the engaged position; (d) spring cone engagement means, for releasably engaging the spring cone such that the spring cone will rotate with the ratchet wheel assembly; and (e) a pair of levers, each lever having a hub section rotatably mountable around the outer surface of the trunnion in association with one of the primary ratchet wheels, each lever having a pawl member with an inner end and an outer end, said inner end defining a cog-engaging surface and a non-engaging surface, each pawl member being mounted to its corresponding lever such that the pawl member may be retractably extended such that the cog-engaging surface may engage the cogs of one of the primary ratchet wheels and its corresponding bridging element;
wherein said apparatus may be substantially coaxially mounted over the shaft when the bridging elements are in the open position, whereupon:
(f) the bridging elements may be moved to, and releasably locked in, the engaged position, thereby to prevent disengagement of the apparatus from the spring shaft; (g) the spring cone engagement means may be releasably engaged with the spring cone; (h) the pawl members may be positioned to engage the cogs of the primary ratchet wheels in a desired orientation; and (i) with the spring cone free to rotate about the spring shaft, the levers may be cooperatively manipulated to rotate the spring cone in a desired direction around the shaft, thereby tensioning or alternatively relaxing the tension in the torsion spring, until a desired degree of tensioning has been achieved, whereupon the spring cone may be locked in position relative to the shaft, the bridging elements may be moved to the open position, and the apparatus may be disengaged from the shaft.
[0034] In the preferred embodiment, the trunnion is a semi-cylindrical sleeve. In an alternative embodiment, the trunnion may be an elongate member having separate cylindrical outer surfaces for rotatably receiving the levers.
[0035] Also in the preferred embodiment, the primary ratchet wheels are mounted at opposite ends of the trunnion. In operation of the apparatus in this embodiment, the levers are mounted onto the trunnion inboard of the primary ratchet wheels. In an alternative embodiment, the primary ratchet wheels are mounted inboard of the ends of the trunnion, such that the levers are mounted onto the trunnion outboard of the primary ratchet wheels. In a variant of this alternative embodiment, the levers may be mounted either inboard or outboard of the primary ratchet wheels.
[0036] In the preferred embodiment, each bridging element is an auxiliary ratchet wheel having substantially the same configuration and features of the primary ratchet wheels. Each auxiliary ratchet wheel is rotatably and coaxially mounted to its corresponding primary ratchet wheel, such that it is rotatable relative to the primary ratchet wheel between the open and engaged position. Unlike the primary ratchet wheels, the auxiliary ratchet wheels need not have cogs around their full perimeter, although that might be convenient or advantageous in some situations. What is important is for the auxiliary ratchet wheels to have sufficient cogs positioned so as to provide a substantially continuous series of cogs around the periphery of the combined primary/auxiliary ratchet wheel combination when in the engaged position. The cogs of the two wheels will necessarily lie in closely adjacent parallel planes, such that the cogs of both wheels are readily engageable by the pawl member of one of the levers.
[0037] Alternatively, each bridging element may be a cogged element smaller than its corresponding primary ratchet wheel, mountable thereto in either hinged or swivelling fashion so that it can either swing or swivel between the open and engaged positions. Where the bridging element is a cogged element hinged to the primary wheel, it may be adapted such that when in the engaged position its cogs will lie in the same plane as the primary wheel cogs. Alternatively, and in embodiments where the bridging element is a swivelling cogged element, its cogs will typically lie in a plane parallel to and closely adjacent to the plane of the primary wheel cogs, as in the case where the bridging elements are auxiliary ratchet wheels.
[0038] In the preferred embodiment, each lever includes pawl biasing means, for biasing the lever's pawl member inwardly toward the primary ratchet wheel on which the lever may be mounted. The pawl biasing means may comprise a spring. Also in the preferred embodiment, each lever includes pawl orientation means, for selectively orienting the cog-engaging surface of the lever's pawl member to accommodate rotation of the ratchet wheel assembly in either direction. The pawl orientation means may be a handle associated with the outer end of the pawl member.
[0039] Each lever preferably includes pawl alignment means, to facilitate positioning of the lever on the trunnion with the lever's pawl member in optimal alignment with the cogs of the corresponding primary ratchet wheel and bridging element. The pawl alignment means may comprise a guide member mounted to the hub section of the lever, with the guide member being rotatable against a rub plate mounted to the trunnion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] Embodiments of the invention will now be described with reference to the accompanying figures, in which numerical references denote like parts, and in which:
[0041] FIG. 1A is an exploded isometric view of the ratchet wheel assembly of the preferred embodiment of the invention, in which the bridging elements are auxiliary ratchet wheels.
[0042] FIG. 1B is an isometric view of a pair of ratchet levers for use in association with the ratchet wheel assembly of the invention.
[0043] FIG. 1C is a side view of a primary ratchet wheel of the preferred embodiment, illustrating the centroidal opening and radial slot thereof.
[0044] FIG. 2 is a side view of the preferred embodiment, with the auxiliary ratchet wheels in the open position, ready for mounting of the apparatus on a spring shaft.
[0045] FIG. 3 is a side view of the preferred embodiment, mounted on a spring shaft with the auxiliary ratchet wheels in the open position.
[0046] FIG. 4 is a side view of the preferred embodiment, mounted on a spring shaft with the auxiliary ratchet wheels in the engaged position.
[0047] FIG. 5 is a partially-sectional elevation of the preferred embodiment, mounted on a spring shaft preparatory to engagement with the spring cone of a torsion spring.
[0048] FIG. 6 is an isometric view of the fully-assembled preferred embodiment, with the auxiliary ratchet wheels in the open position and ready for mounting on a spring shaft.
[0049] FIG. 7 is a side view of a primary ratchet wheel and bridging element in accordance with a first alternative embodiment of the invention.
[0050] FIG. 8 is an end view of the primary ratchet wheel and bridging element shown in FIG. 7 .
[0051] FIG. 9 is a side view of a primary ratchet wheel and bridging element in accordance with a second alternative embodiment of the invention.
[0052] FIG. 10 is an end view of the primary ratchet wheel and bridging element shown in FIG. 9 .
[0053] FIG. 11 is a side view of a primary ratchet wheel and bridging element in accordance with a third alternative embodiment of the invention.
[0054] FIG. 12 is an end view of the primary ratchet wheel and bridging element shown in FIG. 11 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0055] The preferred embodiment of the invention, generally represented by reference numeral 10 , is shown fully assembled in FIG. 6 . To assist in understanding the construction of the preferred embodiment, reference may be made to FIGS. 1 -A, 1 -B, and 1 -C, which illustrate separate components and sub-assemblies forming part of the invention 10 when fully assembled, as will be described later herein. Referring to FIG. 1 -A, a ratchet wheel assembly 20 is made up of two primary ratchet wheels 30 mounted to a trunnion 22 . The trunnion 22 has a semi-cylindrical inner surface 23 slightly larger in diameter than the torsion spring shaft 90 (see FIG. 6 ) on which it is intended to use the apparatus, such that the trunnion 22 can rotate substantially coaxially around the shaft 90 . The trunnion 22 has an open side 24 of a width greater than the diameter D of the shaft 90 so as to allow the trunnion 22 to be removably positioned coaxially over the shaft 90 (as conceptually indicated in FIGS. 2 and 3 ). The trunnion 22 also has a cylindrical outer surface 25 , for purposes that will soon be apparent. In the preferred embodiment, the trunnion 22 is a semi-cylindrical sleeve as shown in the Figures.
[0056] A pair of primary ratchet wheels 30 are fixedly and coaxially mounted to the trunnion 22 in spaced relation. In the preferred embodiment shown in FIG. 1 -A, the primary ratchet wheels 30 are mounted at opposite ends of the trunnion 22 ; however, in alternative embodiments, either or both of the primary ratchet wheels 30 may be mounted a distance inboard from the ends of the trunnion 22 .
[0057] As best understood by reference to FIG. 1 -C, each primary ratchet wheel 30 has a centroidal opening 34 A and a radial slot 34 B, with the latter extending outward to the perimeter 31 of the primary ratchet wheel 30 and creating a perimeter gap 31 A therein. As used in reference to centroidal opening 34 A, the term “centroidal” indicates that centroidal opening 34 A is disposed in the region of the geometric center of primary ratchet wheel 30 . The perimeter of each primary ratchet wheel 30 defines a plurality of uniformly-spaced ratchet teeth, or “cogs” 32 , disposed continuously around the perimeter 31 of the primary ratchet wheel 30 between the edges 31 B of the perimeter gap 31 A.
[0058] In the illustrated embodiments, the portion of centroidal opening 34 A farthest from perimeter gap 31 A is shown as having a semi-circular portion (which is concentric with the primary ratchet wheel); however, this is not essential. What is important regarding the geometrical configuration of centroidal opening 34 A is that it is large enough to enclose a circular shape having a diameter equal to that of inner surface 23 of trunnion 22 (and thus will be at least slightly larger than the cross-section of shaft 90 ), such that there will be no interference when the assembled apparatus 10 is positioned over shaft 90 . It may be preferable or convenient to fashion centroidal opening 34 A with a semi-circular portion to facilitate mounting of the primary ratchet wheel 30 onto trunnion 22 , particularly in embodiments where one or both of the primary ratchet wheels 30 are mounted inboard of the ends of trunnion 22 . It will be appreciated, however, that centroidal opening 34 A could take a different shape, subject to suitable adaptation for concentrically mounting trunnion 22 to primary ratchet wheels 30 .
[0059] As will be appreciated from FIG. 1 -C in particular, centroidal opening 34 A and radial slot 34 B are necessarily contiguous, but they are given separate reference numerals herein for ease of understanding. The radial slot 34 B is shown as being of essentially constant width W, but this is not essential; what is essential is for the minimum slot width W to be greater than the diameter D of the shaft 90 , so as to allow the assembly 10 to be removably positioned coaxially over shaft 90 .
[0060] Also provided, in association with each primary ratchet wheel 30 , is a bridging element with a cogged, arcuate-edged section, for closing off the perimeter gap in the primary ratchet wheel 30 . Each bridging element is operable between:
an “open” position, in which the radial slot 34 B of the associated primary ratchet wheel 30 is clear, so as to permit mounting of the assembled apparatus 10 over the spring shaft 90 , and an “engaged” position in which at least a portion of the bridging element spans the perimeter gap 31 A of its associated primary ratchet wheel 30 , such that there will be a continuous series of cogs around the full perimeter of the primary ratchet wheel 30 , with the cogs of the bridging element providing the effective continuity of cogs across perimeter gap 31 A.
[0063] It will be appreciated by persons skilled in the art that it is not necessary for the bridging element or any portion thereof to be disposed within perimeter gap 31 A of primary ratchet wheel 30 when the bridging element is in the engaged position. In some embodiments (such as those illustrated in FIGS. 9-10 ), the bridging element may be at least partially disposed within the perimeter gap, such that the cogs of the bridging element are substantially aligned with (i.e., co-planar with) the cogs of primary ratchet wheel 30 when the bridging element is in the engaged position. In other embodiments (such as those illustrated in FIGS. 1 -A, 7 , 8 , 11 , and 12 ), the bridging element will lie adjacent to rather than in alignment with primary ratchet wheel 30 when the bridging element is in the engaged position, such that the bridging element cogs lie in a plane substantially parallel to and slightly offset from the plane of primary ratchet wheel 30 .
[0064] Accordingly, the term “bridging” and related forms of this term, as used herein in association with a bridging element of the apparatus, are to be construed as denoting that the bridging element spans (i.e., bridges) perimeter gap 31 A of its associated primary ratchet wheel 30 when in the engaged position, with the cogs of the bridging element being either in a substantially co-planar relationship with the cogs of the primary ratchet wheel 30 , or lying in a plane parallel to and offset from the plane of the primary ratchet wheel 30 .
[0065] As illustrated in FIG. 1 -A and other Figures, the bridging elements in the preferred embodiment will be in the form of auxiliary ratchet wheels 40 similar in construction to the primary ratchet wheels 30 , with each auxiliary ratchet wheels 40 having a corresponding centroidal opening 44 A, radial slot 44 B, and cogs 42 . Each auxiliary ratchet wheel 40 is rotatably mounted (using suitable mounting means) to its corresponding primary ratchet wheel 30 so as to be rotatably operable between the open and engaged positions.
[0066] In the preferred embodiment, as particularly illustrated in FIGS. 2, 3 , and 4 , the mounting means will comprise a pair of arcuate slots 46 in each auxiliary ratchet wheel 40 , plus a pair of stop posts, with each stop post projecting through an associated arcuate slot 46 and anchored to the corresponding primary ratchet wheel 30 . As illustrated in FIG. 1 -A, the stop post may be a machine bolt 54 (with or without washer 56 ) which engages a mating threaded opening 36 in the corresponding primary ratchet wheel 30 . However, it will be readily apparent that the stop post could take any of several other forms.
[0067] The arcuate slots 46 and stop posts are configured such that when an auxiliary ratchet wheel 40 is rotated in one direction until the stop posts hit the ends of their respective arcuate slots 46 , the auxiliary ratchet wheel 40 will be in the open position, and when the auxiliary ratchet wheel 40 is rotated in the other direction until the stop posts hit the other ends of their arcuate slots 46 , the auxiliary ratchet wheel 40 will be in the engaged position, with the spacing of the cogs 42 of the auxiliary ratchet wheel 40 conforming as desired with the spacing of the cogs 32 of the corresponding primary ratchet wheel 30 .
[0068] Although the bridging elements of the embodiments shown in FIGS. 1 -A, 2 , 3 , and 4 (i.e., in the form of auxiliary ratchet wheels) are shown with cogs spaced around their full perimeter, persons skilled in the field will appreciate that this is not essential. Each bridging element need only have enough cogs to span or bridge the perimeter gap 31 A of its associated primary ratchet wheel 30 when the bridging element is in the engaged position. Accordingly, a bridging element in the form of an auxiliary ratchet wheel could have un-cogged perimeter except in a cogged region intended to bridge perimeter gap 31 A in the engaged position. In fact, a bridging element in the form of an auxiliary ratchet wheel, in alternative embodiments, need not form a complete circular shape, provided that it has an arcuate cogged region adapted to bridge perimeter gap 31 A in the corresponding primary ratchet wheel 30 .
[0069] The apparatus of the invention also includes locking means, for releasably securing each bridging element in the engaged position such that cogs of the bridging element cannot be displaced relative to the cogs of the associated primary ratchet wheel 30 . In the preferred embodiment, and as particularly illustrated in FIGS. 2, 3 , and 4 , the locking means is provided by way of a releasable pin 52 or other fastener that may be inserted through an opening 48 B in the auxiliary ratchet wheel 40 into a mating opening 38 in the corresponding primary ratchet wheel 30 . The pin 52 may be loose or, preferably, mounted to the auxiliary ratchet wheel 40 in spring-loaded fashion such that it will be biased to stay engaged in opening 38 when inserted therein, but may be conveniently withdrawn therefrom as desired. Although not essential to the invention, an additional opening 48 A may be provided in the auxiliary ratchet wheel 40 for holding the auxiliary ratchet wheel 40 in the open position, with said opening 48 A being located so as to align with opening 38 when the auxiliary ratchet wheel 40 is in the open position. It will be readily appreciated by those skilled in the art that various other locking means may be used without departing from the fundamental concept or scope of the present invention.
[0070] In alternative embodiments, the bridging element may be a comparatively small member with a cogged, arcuate-edged section just large enough to span the perimeter gap of the corresponding primary ratchet wheel 30 . In a first alternative embodiment, shown in FIGS. 7 and 8 , bridging element 140 , with cogs 132 , is attached to modified corresponding primary ratchet wheel 130 by means of hinge 142 adjacent one edge of the radial slot 34 B, such that it can swing between the engaged position (in which it will lie adjacent to the primary ratchet wheel 130 ) and the open position).
[0071] In a second alternative embodiment, shown in FIGS. 9 and 10 , the bridging element 240 , with cogs 242 , is attached to modified corresponding primary ratchet wheel 230 by means of hinge 242 adjacent one edge of the radial slot 34 B, such that it will lie in substantially co-planar relation with primary ratchet wheel 230 when in the engaged position, as indicated by the solid lines in FIG. 10 (in which dotted lines also illustrate bridging element 240 in the open position).
[0072] In a third alternative embodiment, shown in FIGS. 11 and 12 , the bridging element 340 , with cogs 342 , is swivellingly mounted to modified corresponding primary ratchet wheel 330 so that it swivels between the open and engaged positions about an axis parallel to the axis of the primary ratchet wheel 330 (for example, about a pivot pin 350 as illustrated). In this third embodiment, bridging element 340 may be secured in the engaged position by means analogous to the securing means previously described for the embodiment illustrated in FIG. 1 -A; i.e., by providing holes 336 and 346 in primary ratchet wheel 330 and bridging element 340 respectively, through which a suitable bolt or pin may be inserted so as to releasably lock bridging element 340 in the engaged position.
[0073] In a yet further embodiment, the bridging element could take the form of a segment of an auxiliary ratchet wheel 40 as illustrated in FIGS. 3 and 4 , with an arcuate slot 46 having a pair of stop posts extending therethrough, so as to allow the bridging element to rotate concentrically relative to its corresponding primary ratchet wheel 30 .
[0074] The invention 10 also includes spring cone engagement means 60 , which may take a variety of forms well known in the art of the invention. In the preferred embodiment illustrated in FIGS. 1 -A, 5 , and 6 , the spring cone engagement means 60 has a central hub 62 and at least one outwardly-extending bracket 64 having mounted thereto a radially-oriented sleeve 66 which slidingly receives a cone-engaging pin 68 adapted to be insertable into a socket 96 of a spring cone 94 . The pin 68 may be spring-loaded to bias it radially inward, such that it will tend to stay engaged in the socket 96 when engaged therein. Alternatively, and as illustrated in FIG. 5 , the pin 68 may have an operating wand 69 that extends through an L-shaped slot 67 in sleeve 66 , such that the pin 68 can slide within the sleeve 66 by moving the wand 69 within one leg 67 A of the L-shaped slot 67 for purposes of inserting the pin 68 into the socket 96 or retracting it therefrom, and such that the pin 68 can be releasably locked in position inside the socket 96 by moving the wand 69 into the other leg 67 B of the L-shaped slot 67 .
[0075] The spring cone engagement means 60 is mounted to other components of the invention 10 such that it will rotate with the ratchet wheel assembly 20 . In the preferred embodiment, and as particularly illustrated in FIGS. 1 -A, 5 , and 6 , this is accomplished by rigidly connecting the spring cone engagement means 60 to one of the auxiliary ratchet wheels 40 , such as by welding. In other embodiments, however, such as where the bridging elements are comparatively small and do not cover the entire surface of their associated primary ratchet wheels 30 , the spring cone engagement means 60 may be mounted directly to one of the primary ratchet wheels 30 .
[0076] The invention 10 also comprises a pair of ratchet levers 70 , as illustrated in FIG. 1 -B. Each lever 70 has a hub assembly 74 adapted to be rotatably mounted around the outer surface 25 of the trunnion 22 , and for that purpose will preferably have a bushing element 72 with an inner diameter slightly greater than the diameter of the outer surface 25 of the trunnion 22 . The configuration of the hub assemblies 74 as shown in the Figures is merely representative; various other hub configurations could be used without departing from the scope of the invention.
[0077] Each lever 70 also has a pawl assembly 80 comprising a pawl member 82 with an inner end 82 A and an outer end 82 B, with the inner end 82 A defining a cog-engaging surface 83 A and a non-engaging surface 83 B. The pawl member 82 is mounted to the lever 70 in any suitable fashion such that its inner end 82 A can be retractably extended inward toward the hub 74 . In the particular embodiment shown in FIG. 1 -B and FIGS. 2 through 6 , the outer end 82 B of the pawl member 82 passes slidably through a bracket 86 mounted to the lever 70 , and the inner end 82 A of the pawl member 82 passes slidably through an opening in the hub 74 . In the preferred embodiment, the pawl member 82 is provided with a spring 84 (with spring retainer means 84 A) or other biasing means, for biasing the pawl member 82 inward toward the hub 74 .
[0078] Preferably, the pawl member 82 is also provided with pawl-orientation means, for orienting the cog-engaging surface 83 A as desired, depending on the direction in which the lever 70 is to be operated. As illustrated in the Figures, the pawl-orientation means can be provided by way of a handle 88 associated with the outer end 82 B of the pawl member 82 . However, this is merely one example, and those skilled in the art of the invention will understand that various other pawl-orientation means could be used without departing from the concept or scope of the invention.
[0079] Assembly of the preferred embodiment of the invention 10 may now be readily understood having reference to FIGS. 5 and 6 in particular. The levers 70 are positioned between the primary ratchet wheels 30 so as to be rotatable around the outer surface 25 of the trunnion 22 , with the pawl member 82 of each lever 70 aligned so as to be able to engage the cogs 32 of one of the primary ratchet wheels 30 as well as the cogs 42 of the associated auxiliary ratchet wheel 40 (or other form of bridging element) as the case may be. In the illustrated embodiment, the required alignment of the pawl members 82 is accomplished by providing rub plates 26 on the trunnion 22 and providing a guide member (typically a flat plate) 76 in association with each hub 74 , with these components being configured and positioned such that the pawl members 82 will be properly aligned when the levers 70 are rotated with their guide members 76 closely adjacent their corresponding rub plates 26 . Persons skilled in the art of the invention will readily appreciate that other suitable alignment means may be devised without departing from the scope of the invention.
[0080] In the illustrated embodiment, the levers 70 cannot be readily removed from the ratchet wheel assembly 20 because of the geometry of the assembly, and in particular the fact that the hubs 74 in the illustrated embodiment closely enshroud their corresponding primary ratchet wheels 30 . In this arrangement, the invention 10 has no loose components that might be inadvertently misplaced. More significantly, perhaps, this arrangement prevents the levers 70 from flying loosely away from the ratchet wheel assembly in the event of an unexpected unwinding of a torsion spring being tensioned with the apparatus. However, there may be circumstances in which it will be desirable for the levers 70 to be removable, which can be easily accomplished by modifying the configuration of the hubs 74 (e.g., by making them essentially semi-circular or smaller) so that they can be mounted directly over their corresponding primary ratchet wheels 30 .
[0081] The operation of the present invention may now be easily understood having particular reference to FIGS. 5 and 6 . With the bridging elements in the open position, the apparatus of the invention 10 is coaxially mounted over a torsion spring shaft 90 adjacent a spring cone 94 on the side opposite the torsion spring 92 anchored thereto. The apparatus is then moved laterally as required such that the spring cone engagement means 60 can engage the spring cone 94 . The bridging elements are moved to their engaged positions and locked; as preferred or convenient, this step may be taken either before or after engagement of the spring cone 94 . With the spring cone 94 free to rotate about the shaft 90 , with the pawl members 82 oriented as desired, and with the pawl-engaging surfaces 83 A aligned to engage cogs 32 and/or 42 as the case may be, the two levers 70 may be operated with one lever 70 being used to restrain the spring 92 from unwinding while the other lever 70 is operated in typical ratchet fashion so as to rotate the spring cone engaging means 60 , in turn tensioning (or relaxing the tension in) the spring 92 , depending on the direction of rotation. When the spring 92 has reached the desired level of tension, the spring cone 94 may be anchored to the shaft 90 (typically by means of set screws 98 as shown in FIG. 5 ), whereupon the spring cone engaging means 60 may be disengaged, the bridging elements may be moved to the open position, and the apparatus may be removed from the shaft 90 .
[0082] It will be readily appreciated by those skilled in the art that various modifications of the present invention may be devised without departing from the essential concept of the invention, and all such modifications are intended to be included in the scope of the claims appended hereto.
[0083] In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following that word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one such element.
|
Apparatus for tensioning torsion spring, shaft-mounted in association with a spring cone, has a central ratchet assembly with two spaced, cogged ratchet wheels, slotted to allow the assembly to be rotatably positioned over the shaft. The ratchet assembly is connectable to the spring cone so that the spring cone will rotate with the ratchet assembly. The ratchet wheel slots are closed off by cogged bridging elements that create a continuous cogged perimeter around each ratchet wheel. Pawl-equipped levers are positioned over the ratchet wheels with the pawls engageably aligned with the ratchet wheel cogs, and then operated in alternating fashion to rotate the ratchet assembly and spring cone, thus tensioning the spring. Upon achieving a desired spring tension, the spring cone may be secured to the shaft, whereupon the bridging elements may be retracted from the ratchet wheel slots to permit removal of the apparatus from the shaft.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is related to U.S. patent application Ser. No. 10/689,345 entitled “Method for Load Balancing a Line of Parallel Processing Elements” filed 20 Oct. 2003, U.S. patent application Ser. No. 10/689,312 entitled “Method for Using Extrema to Load Balance a Loop of Parallel Processing Elements” filed 20 Oct. 2003, U.S. patent application Ser. No. 10/689,336 entitled “Method for Load Balancing a Loop of Parallel Processing Elements” filed 20 Oct. 2003, U.S. patent application Ser. No. 10/689,355 entitled “Method for Using Filtering to Load Balance a Loop of Parallel Processing Elements” filed 20 Oct. 2003, U.S. patent application Ser. No. 10/689,365 entitled “Method for Load Balancing an N-Dimensional Array of Parallel Processing Elements” filed 20 Oct. 2003, and U.S. patent application Ser. No. 10/689,280 entitled “Method of Obtaining Interleave Interval for Two Data Values” filed 20 Oct. 2003.
BACKGROUND OF THE INVENTION
The present invention relates generally to parallel processing and more particularly to algorithms employed to balance the work loads of the processing elements within a parallel processing system.
Conventional central processing units (“CPU's”), such as those found in most personal computers, execute a single program (or instruction stream) and operate on a single stream of data. For example, the CPU fetches its program and data from a random access memory (“RAM”), manipulates the data in accordance with the program instructions, and writes the results back sequentially. There is a single stream of instructions and a single stream of data (note: a single operation may operate on more than one data item, as in X=Y +Z, however, only a single stream of results is produced). Although the CPU may determine the sequence of instructions executed in the program itself, only one operation can be completed at a time. Because conventional CPUs execute a single program (or instruction stream) and operate on a single stream of data, conventional CPUs may be referred to as a single-instruction, single data CPU or an SISD CPU.
The speed of conventional CPUs has dramatically increased in recent years. Additionally, the use of cache memories enables conventional CPUs faster access to the desired instruction and data streams. However because conventional CPUs can complete only one operation at a time, conventional CPUs are not suitable for extremely demanding applications having large data sets (such as moving image processing, high quality speech recognition, and analytical modeling applications, among others).
Improved performance over conventional SISD CPUs may be achieved by building systems which exhibit parallel processing capability. Typically, parallel processing systems use multiple processing units or processing elements to simultaneously perform one or more tasks on one or more data streams. For example in one class of parallel processing system, the results of an operation from a first CPU are passed to a second CPU for additional processing, and from the second CPU to another CPU, and so on. Such a system, commonly known as a “pipeline”, is referred to as a multiple-instruction, single-data or MISD system because each CPU receives a different instruction stream while operating on a single data stream. Improved performance may also be obtained by using a system which contains many autonomous processors, each running its own program (even if the program running on the processors is the same code) and producing multiple data streams. Systems in this class are referred to as a multiple-instruction, multiple-data or MIMD system.
Additionally, improved performance may be obtained using a system which has multiple identical processing units each performing the same operations at once on different data streams. The processing units may be under the control of a single sequencer running a single program. Systems in this class are referred to as a single-instruction, multiple data or SIMD system. When the number of processing units in this type of system is very large (e.g., hundreds or thousands), the system may be referred to as a massively parallel SIMD system.
Nearly all computer systems now exhibit some aspect of one or more of these types of parallelism. For example, MMX extensions are SIMD; multiple processors (graphics processors, etc) are MIMD; pipelining (especially in graphics accelerators) is MISD. Furthermore, techniques such as out of order execution and multiple execution units have been used to introduce parallelism within conventional CPUs as well.
Parallel processing is also used in active memory applications. An active memory refers to a memory device having a processing resource distributed throughout the memory structure. The processing resource is most often partitioned into many similar processing elements (PEs) and is typically a highly parallel computer system. By distributing the processing resource throughout the memory system, an active memory is able to exploit the very high data bandwidths available inside a memory system. Another advantage of active memory is that data can be processed “on-chip” without the need to transmit the data across a system bus to the CPU or other system resource. Thus, the work load of the CPU may be reduced to operating system tasks, such as scheduling processes and allocating system resources.
A typical active memory includes a number of interconnected PEs which are capable of simultaneously executing instructions sent from a central sequencer or control unit. The PEs may be connected in a variety of different arrangements depending on the design requirements for the active memory. For example, PEs may be arranged in hypercubes, butterfly networks, one-dimensional strings/loops, and two-dimensional meshes, among others.
In typical active memories, load imbalances often occur such that some PEs are idle (i.e., without assigned tasks) while other PEs have multiple tasks assigned. To maximize the effectiveness of the active memory, it is desirable to balance the work load across all of the PEs. For example in an active memory having a multitude of identical PEs, it is desirable that each PE be assigned the same number of instructions by the central sequencer, thus maximizing the resources of the active memory. Additionally in an active memory having non-identical PEs, it may be desirable to assign more tasks to the PEs with greater processing capabilities. By balancing the load, the amount of time that one or more PEs is idle while waiting for one or more other PEs to complete their assigned tasks is minimized.
In some instances, the mean value of instructions encountered by all PEs within an array may be used by a balancing method for redistributing tasks within the array. However, rounding errors caused by prior art algorithms and methods for finding the mean value of tasks often cause tasks to be “lost” or “gained”.
Thus, there exists a need for a method for balancing the load of a parallel processing system such that the resources of the parallel processing system are maximized. For example, there exists a need for a method for balancing the load of an active memory such that the resources of the active memory are maximized. More specifically, there exits a need for a method for determining the mean value of tasks assigned to PEs such that rounding errors are eliminated and tasks are not lost or gained.
SUMMARY OF THE INVENTION
One aspect of the present invention relates to a method for calculating a local mean number of tasks for each processing element (PE r ) in a parallel processing system, wherein each processing element (PE r ) has a local number of tasks associated therewith and wherein r represents the number for a selected processing element. The method comprising assigning a value (E r ) to the each processing element (PE r ), summing a total number of tasks present on the parallel processing system, further augmenting said sum by adding the value (E r ) on each processing element (PE r ), dividing the augmented sum for the each processing element (PE r ) by a total number of processing elements in the parallel processing system and truncating a fractional portion of the divided sum for each processing element.
The present invention enables local mean calculations to be completed without introducing rounding errors which may, for example, have adverse effects on subsequent load balancing methods related to an array of processing elements. The present invention enables tasks to be distributed within a network of connected PEs so that each PE typically has X number of tasks or (X+1) number of tasks to perform in the next phase. The present invention may be performed using the hardware and software (i.e., the local processing capability) of each PE within the array. Those advantages and benefits, and others, will become apparent from description of the invention below.
BRIEF DESCRIPTION OF THE DRAWINGS
To enable the present invention to be easily understood and readily practiced, the present invention will now be described for purposes of illustration and not limitation, in connection with the following figures wherein:
FIG. 1 is a block diagram illustrating an active memory according to an embodiment of the present invention.
FIG. 2 is a block diagram of a processing element for the active memory illustrated in FIG. 1 according to an embodiment of the present invention.
FIG. 3 illustrates an array of the processing elements illustrated in FIG. 2 arranged in a line according to an embodiment of the present invention.
FIG. 4 illustrates an operational process for an improved rounding function for rounding the local mean value of one or more processing elements within an array according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As discussed above, parallel processing systems may be placed within one or more classifications (e.g., MISD, MIMD, SIMD, etc.). For simplicity, the present invention is discussed in the context of a SIMD parallel processing system. More specifically, the present invention is discussed in the context of a SIMD active memory. It should be noted that such discussion is for clarity only and is not intended to the limit the scope of the present invention in any way. The present invention may be used for other types and classifications of parallel processing systems.
FIG. 1 is a block diagram illustrating an active memory 10 according to an embodiment of the present invention. It should be noted that the active memory 10 is only one example of a device on which the methods of the present invention may be practiced and those of ordinary skill in the art will recognize that the block diagram of FIG. 1 is an overview of an active memory device 10 with a number of components known in the art being omitted for purposes of clarity.
Active memory 10 is intended to be one component in a computer system. Processing within active memory 10 is initiated when the active memory 10 receives commands from a host processor (not shown), such as the computer system's CPU. A complete processing operation (i.e., data movement and processing) in the active memory 10 may consist of a sequence of many commands from the host to the active memory device 10 .
Active memory 10 is comprised of a host memory interface (“HMI”) 12 , a bus interface 14 , a clock generator 16 , a task dispatch unit (“TDU”) 18 , a DRAM control unit (“DCU”) 20 , a DRAM module 22 , a programmable SRAM 24 , an array control sequencer 26 , and a processing element array 28 , among others.
The HMI 12 provides an input/output channel between the host (such as a CPU, not shown) and the DRAM module 22 . In the current embodiment, the HMI 12 receives command (cmd), address (addr), and data signals (among others) from and sends data and ready (rdy) signals (among others) to the host. The HMI 12 approximates the operation of a standard non-active memory so that the host, without modifications, is compatible with the active memory 10 .
The HMI 12 may be similar in its operation to the interface of a synchronous DRAM as is know in the art. Accordingly, the host must first activate a page of data to access data within a DRAM module 22 . In the current embodiment, each page may contain 1024 bytes of data and there may be 16,384 pages in all. Once a page has been activated, it can be written and read through the HMI 12 . The data in the DRAM module 22 may be updated when the page is deactivated. The HMI 12 also sends control signals (among others) to the DCU 20 and to the processing element array 28 via the task dispatch unit 18 .
The HMI 12 may operate at a frequency different than that of the frequency of the master clock. For example, a 2× internal clock signal from clock generator 16 may be used. Unlike a traditional DRAM, the access time for the HMI 12 uses a variable number of cycles to complete an internal operation, such as an activate or deactivate. Thus, the ready signal (rdy) is provided to allow the host to detect when a specific command has been completed.
The bus interface 14 provides and input/output channel between the host and the TDU 18 . For example, the bus interface 14 receives column select (cs), write command (w), read command (r), address (addr), and data signals (among others) from and places interrupt (intr), flag, and data signals (among others) onto the system bus (not shown). The bus interface 14 also receives signals from and sends signals to TDU 18 .
The clock generator 16 is operable to receive an external master clock signal (x 1 ) and operable to provide the master clock signal (x 1 ) and one or more internal clock signals (x 2 , x 4 , x 8 ) to the components of the active memory. It should be apparent to one skilled in the art that other internal clock signals may be produced by the clock generator 16 .
The TDU 18 communicates with the bus interface 14 , the HMI 12 , the programmable SRAM 24 , the array control sequencer 26 , and the DCU 20 . In the current embodiment, the TDU 18 functions as an interface to allow the host to issue a sequence of commands to the array control sequencer 26 and the DCU 20 . Task commands from the host may be buffered in the TDU's FIFO buffers to allow a burst command to be issued. Commands may contain information on how the tasks in the array control sequencer 26 and the DCU 20 should be synchronized with one another, among others.
The DCU 20 arbitrates between the TDU 18 and the HMI 12 and sends commands to the DRAM modules 22 and the processing element array 28 . The DCU 20 also schedules refreshes within the DRAM modules 22 . In one embodiment, the DRAM modules 22 of the active memory 10 may be comprised of sixteen 64 k×128 eDRAM (or embedded DRAM) cores. Each eDRAM core may be connected to an array of sixteen PEs, thus requiring 256 (16×16) PEs in all.
The programmable SRAM 24 functions as a program memory by storing commands issued by the TDU 18 . For example, the TDU 18 may transmit a “write program memory address” command which sets up a start address for a write operation and a “write program memory data” command which writes a memory location and increments the program memory write address, among others. The programmable SRAM 24 , in the current embodiment, has both an address register and a data output register.
The array control sequencer 26 is comprised of a simple 16 bit minimal instruction set computer (16-MISC). The array control sequencer 26 communicates with the TDU 18 , the programmable SRAM 24 , and the DCU 20 , and is operable to generate register file addresses for the processing element array 28 and operable to sequence the array commands, among others.
The processing element array 28 is comprised of a multitude of processing elements (“PEs”) 30 (see FIG. 2 ) connected in a variety of different arrangements depending on the design requirements for the processing system. For example, processing units may be arranged in hypercubes, butterfly networks, one-dimensional strings/loops, and two-dimensional meshes, among others. In the current embodiment, the processing elements 30 are arranged in a line (for example, see FIG. 3 ). The processing element array 28 communicates with the DRAM module 22 and executes commands received from the programmable SRAM 24 , the array control sequencer 26 , the DCU 20 , and the HMI 12 . Each PE in the processing element array 28 includes dedicated H-registers for communication with the HMI 12 . Control of the H-registers is shared by the HMI 12 and the DCU 20 .
Referring now to FIG. 2 , a block diagram of a PE 30 according to one embodiment of the present invention is illustrated. PE 30 includes an arithmetic logic unit (“ALU”) 32 , Q-registers 34 , M-registers 36 , a shift control and condition register 38 (also called “condition logic” 38 ), a result register pipeline 40 , and register file 42 . The PE 30 may also contain other components such as multiplexers 48 and logic gates (not shown), among others.
In the current embodiment, the Q-registers 34 are operable to merge data into a floating point format and the M-Registers 36 are operable to de-merge data from a floating point format into a single magnitude plus an exponent format. The ALU 32 is a multiplier-adder operable (among others) to receive information from the Q-registers 34 and M-registers 36 , execute tasks assigned by the TDU 18 (see FIG. 1 ), and transmit results to the shift control and condition register 38 and to the result register pipeline 40 . The result register pipeline 40 is operable to communicate with the register file 42 , which holds data for transfer into or out of the DRAM modules 22 via a DRAM interface 44 . Data is transferred between the PE and the DRAM module 22 via a pair a registers, one register being responsive to the DCU 20 and the other register being responsive to the PE 30 . The DRAM interface receives command information from the DCU 20 . The DRAM interface 44 also permits the PE 30 to communicate with the host through the host memory access port 46 .
In the current embodiment, the H-registers 42 are comprised of synchronous SRAM and each processing element within the processing element array 28 contains eight H-registers 42 so that two pages can be stored from different DRAM locations, thus allowing the interleaving of short i/o bursts to be more efficient. Result register pipeline 40 is also connected to one or more neighborhood connection registers (“X-register”) (not shown). The X-register links one PE 30 to its neighboring PE's 30 in the processing element array 28 .
The reader desiring more information about the hardware shown in FIGS. 1 and 2 is directed to UK Patent application No. 0221563.0 entitled “Control of Processing Elements in Parallel Processors” filed 17 Sep. 2002, which is hereby incorporated by reference. Details about the PEs may also be found in UK Patent Application No. 021562.2 entitled “Host Memory Interface for a Parallel Processor” filed 17 Sep. 2002, which is hereby incorporated by reference.
FIG. 3 is a simplified diagram showing the interconnections of an array of PEs 30 (as illustrated in FIG. 2 ) arranged in a line 50 according to an embodiment of the present invention. In the current embodiment, line 50 is comprised of eight (8) PEs (i.e., PE r , where r=0, 1, 2 . . . 7) which are interconnected via their associated X-register links. It should be noted that the number of PEs 30 included in line 50 may be altered while remaining within the scope of the present invention. It should further be noted that although the current embodiment is discussed with respect to a single line of PEs, the present invention is applicable to other arrangements as well. For example, the present invention may be employed for PEs arranged in N×N n-dimensional arrays, one-dimensional loop arrays, hypercubes, butterfly networks, two-dimensional meshes, etc. while remaining with the scope of the present invention. In the current embodiment, each PE 30 in line 50 is operable to receive instructions from TDU 18 as discussed in conjunction with FIG. 1 .
As illustrated in FIG. 3 , each PE r has a local number of tasks (v r ) associated therewith. For example, PE 0 , PE 1 , PE 2 , . . . PE 7 have local number of tasks v 0 =3, v 1 =6, v 2 =2 . . . v 7 =7, respectively, associated therewith. PE 1 through PE 6 are operable to communicate with both their left and right neighboring PEs. For example, PE 1 can communicate with PE 0 (i.e., PE 1 's left neighbor) and with PE 2 (i.e., PE 1 's right neighbor). In the current embodiment, the line's 50 left end PE (i.e., PE 0 ) is operable to communicate with its right neighbor (i.e., PE 1 ), whereas the line's 50 right end PE (i.e., PE 7 ) is operable to communicate with its left neighbor (i.e., PE 6 ). It should be noted, however, that each PE on the end of line 50 (i.e., PE 0 and PE 7 ) may also be operable to communicate with a PE from another line (e.g., to link two or more lines in an array) or to communicate with each other (e.g., PE 0 and PE 7 may communicate to permit a wrap function).
It should be noted that “line” refers to at least two serially connected PEs. It should be apparent to one skilled in the art that “line” is intended to include PE's arranged in a linear array (e.g., rows, columns, diagonals, etc.) and other non-linear shapes. It should also be apparent to one skilled in the art that serially connected arrays having uniform and/or varied distances between one or more of the PEs are within the scope of the present invention.
In the current embodiment, the total number of tasks (V) on the line 50 may be found by summing the local number of tasks (v r ) associated we each PE r in the line 50 . In the current embodiment, a partial sum (S r ) of the number of tasks (v r ) is passed from a first end to a second end of the line 50 (e.g., from the leftmost PE to the rightmost PE). The partial sum (S r ) is initialized to the number of tasks on the first end (here S 0 =v 0 ). The partial sum (S r ) is then passed serially from PE r to PE r+1 (i.e., from left to right). Each PE r receives the partial sum and adds it's own number of tasks to the partial sum (i.e., S r =S r+1 +v r ). After adding it's number of tasks (v r ), PE r passes the partial sum (S r ) to PE r+1 . When the partial sum (S r ) reaches the right end (i.e., PE N−1 ), the last tasks (V N−1 ) are added to form the total sum of tasks (V). The sum (V) can be expressed by the equation
V = ∑ i = 0 i = N - 1 v i ,
where N represents the number of PEs 30 in the line 50 , and v i represents the local number of tasks associated with a local PE r in the line 50 . It should also be noted that in the current discussion, “local” refers to the values or functions associated with a single PE within the line, whereas “global” refers to the values or functions associated with the entire line of PEs. It should be noted that other methods of finding the total number of task may be used while remaining within the scope of the present invention.
Referring to FIG. 3 , PE 0 has 3 tasks associated therewith (i.e., v 0 =3). Thus, the initial value for the partial sum is also 3 (i.e., S 0 =v 0 =3). The partial sum is then passed to PE 1 , which has 6 tasks associated therewith (i.e., v 1 =6). The number of tasks associated with PE 1 is then added to the partial sum S 0 to obtain S 1 =9 (i.e., S 1 =S 0 +v 1 ). The partial sum continues to be passed serially until it reaches the right end of line 50 (i.e., PE 7 ). As illustrated in FIG. 3 , the total sum of tasks on line 50 is equal to forty-three (i.e., V=43).
It may be desirable for some applications to find a local mean value of tasks (M r ) for each PE r on the line 50 . For example, the local mean value (M r ) may be used in methods for balancing the load among the PEs on the line 50 . Using the total sum of tasks (V), a local mean value for each PE on the line 50 can be determined. Using a simple mean function (i.e., without the use of a rounding algorithm), the mean value for each PE r (i.e., PE 0 . . . PE 7 ) in the current embodiment may be calculated as
M r = V N ,
where M r represents the local mean value of tasks for PE r , V represents the total number of tasks on the line 50 , and N represents the number of PEs 30 in the line 50 .
This simple mean function, however, produces rounding errors that may impact later load balancing processes. For example in the current embodiment, forty-three (43) tasks (i.e., V=43) are to be shared by the eight PEs in line 50 (i.e., PE 0 through PE 7 ). The local mean for each PE, using the simple mean function, would be PE r =5.375 (i.e., 43÷8=5.375). If the result (i.e., 5.375) is designated to round down for each PE (i.e., 43÷8 is set equal to 5), then the sum of the means for all of the individual PEs (i.e., PE 0 through PE 7 ) will be equal to 40. Thus, three (43−40=3) tasks are lost. In contrast, if the result (i.e., 5.375) is designated to round up for each PE (i.e., 43÷8 is set equal to 6), then the sum of the means for all of the individual PEs (i.e., PE 0 through PE 7 ) will be equal to 48. Thus, five (48−43=5) tasks are gained. Accordingly, the simple mean function introduces errors into any subsequent load balancing process.
A rounding function that satisfies the equation
V = ∑ i = 0 i = N - 1 M i
(where N represents the number of PEs 30 in the line 50 , and M i represents the local mean of tasks associated with a local PE r in the line 50 ) is desirable to prevent rounding errors. In other words, it is desirable that the sum of the local means (M r ) for all PEs on the line 50 equals the total number of tasks (V) on the line such that tasks are neither “lost” nor “gained” during a mean calculation step.
FIG. 4 illustrates an operational process 60 for an improved rounding function for rounding the local mean value of one or more processing elements within an array according to an embodiment of the present invention. Operational process 60 begins with E r values being assigned to the PEs in the line in operation 61 , where E r represents a number in the range of 0 to (N−1). In the current embodiment, each PE r is assigned a different E r value for controlling the rounding. The simplest form for the function E is the case in which E r =P r , the number of the PE. For example, for PE 0 , E 0= 0; for PE 1 , E 1= 1; for PE 2 , E 2 =2; etc Table #1 below.) By assigning each PE 30 a different E r value, the rounding function can be controlled such that some of the local means are rounded up and some of the local means are rounded down, thus insuring that
V
=
∑
i
=
0
i
=
N
-
1
M
i
.
After the E r values are assigned in operation 61 , the total number of tasks (V) present on the line 50 is added to the E r value for each PE r . For example, in the case in which forty-three (43) tasks are present on the line, forty-three (43) is added to E 0 (i.e., 43+0=43), E 1 (i.e., 43+1=44), E 2 (i.e., 43+2=45), and E 7 (i.e., 43+7=50). (See Table #1 below.)
After the total number of tasks is added to each E r value in operation 62 , the sum of the total number of tasks (V) and the E r value is divided by the number of PEs on the line (N) in operation 63 . As mentioned above, the line 50 is comprised of eight (8) PEs. Thus, each sum found in operation 62 is divided by eight (8). (See Table #1 below.)
After the sums of the total number of tasks and the E r value is divided the number of PEs on the line (N) in operation 63 , the results for each PE r are truncated in operation 64 . More specifically, any fractional part of the result is truncated (i.e., removed) such that only an integer remains. The results obtained for each PE r in the current embodiment are illustrated in Table 1. For example prior to operation 64 , PE 2 had a value of five-and-five-eighths (i.e., 5.625), whereas after truncation in operation 64 PE 2 has a value of five (5).
Referring to Table #1, it is apparent that the sum of column “Trunc(V+E r )/N)” is equal to forty-three (43). Thus, the equation
V = ∑ i = 0 i = N - 1 M i
is satisfied and no tasks have been gained or lost. After the results are truncated in operation 64 , operational process 60 is terminated. It should be noted that in the current embodiment, operational process 60 is completed in parallel for each PE r on line 50 .
TABLE #1
Local Mean Calculation for V = 43, N = 8.
PE r
E r
(V + E r )/N
Trunc((V + E r )/N)
PE 0
0
5.375
5
PE 1
1
5.5
5
PE 2
2
5.625
5
PE 3
3
5.75
5
PE 4
4
5.875
5
PE 5
5
6
6
PE 6
6
6.125
6
PE 7
7
6.25
6
Table #1 illustrates the local mean calculation for the current embodiment in which the total number of tasks on the line 50 (which is comprised of eight PEs) is equal to forty-three (43). Referring to Table 1, it is apparent that the rounding function controls the rounding such that M 0 through M 4 are rounded to five (5), whereas M 5 through M 7 are rounded to six (6). The sum of the values of M 0 through M 7 is equal to 43, which is equal to the total number of tasks (V) on the line 50 . Thus, tasks were neither lost nor gained due to rounding.
Referring to Table #1, it should be apparent that a PE r having an E r function set to a lower value (e.g., 0, 1, 2, . . . ) tends to have a local mean of X, whereas a PE r having an E r function set to a higher value (e.g., (N−1), (N−2), (N−3), . . . ) tends to have a local mean of (X+1). Accordingly, it should be noted that the form for the function E may be altered from the case in which E r =P r , to obtain other results. For example, the values assigned may be reversed to obtain the results shown in Table #2 or the values interleaved to obtain the results shown in Table #3. It should be apparent that other forms of the function E may be used while remaining within the scope of the present invention.
TABLE #2
Local Mean Calculation for V = 43, N = 8, Reverse Function for E r .
PE r
0
1
2
3
4
5
6
7
E r
7
6
5
4
3
2
1
0
M r
6
6
6
5
5
5
5
5
TABLE #2
Local Mean Calculation for V = 43, N = 8, Interleave Function for E r .
PE r
0
1
2
3
4
5
6
7
E r
0
4
2
6
1
5
3
7
M r
5
5
5
6
5
6
5
6
It should be recognized that the above-described embodiments of the invention are to be illustrative only. Numerous alternative embodiments may be devised by those n the art without departing from the scope of the following claims.
|
A method for calculating a local mean number of tasks for each processing element (PE r ) in a parallel processing system, wherein each processing element (PE r ) has a local number of tasks associated therewith and wherein r represents the number for a selected processing element, the method comprising assigning a value (E r ) to the each processing element (PE r ), summing a total number of tasks present on the parallel processing system and the value (E r ) for the each processing element (PE r ), dividing the sum of the total number of tasks present on the parallel processing system and the value (E r ) for the each processing element (PE r ) by a total number of processing elements in the parallel processing system and truncating a fractional portion of the divided sum for the each processing element.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
This invention applies to paper webs or sheets, and more specifically to tissue or paper tissue webs, that are commonly used in paper towels, napkins, facial and toilet tissues. The important characteristics for such papers (simply referred to as ‘tissue papers’ from this point on) are bulk, softness, absorbency, stretch and strength. There is an ongoing work to improve each of these characteristics without seriously affecting the others. Methods for making conventional wet pressed (CWP) and through-air-dried (TAD) tissue papers are well known in the art. Both types of tissue papers are formed by draining a cellulosic fiber suspension through a forming fabric to create the paper web. The cellulosic fiber suspension is deposited onto the forming fabric by means of a headbox which uniformly deposits the suspension. Depending on machine type, there can be some initial vacuum or centrifugal dewatering of the web. For CWP tissue papers, the web is further dewatered at the pressure roll, where the sheet is pressed between the pressure roll and the Yankee dryer to a typical consistency of 40-45%. Final drying is accomplished by the steam heated Yankee dryer in combination with hot air impingement hoods. For TAD tissue papers the web is further dried by the through-air dryer(s) which force hot air through the web to obtain a typical consistency of 60-85%. Again, final drying is accomplished by the steam heated Yankee dryer in combination with hot air impingement hoods.
Conventional fluff pulp and methods for making such pulp are well known in the art. Important properties include absorbency, burst strength and specific shredding energy. Such pulp is typically made by forming a thick web or sheet on a Fourdrinier wire and subsequently pressing and drying the paper sheet into bales or rolls having a consistency of 8-10%. The dry bales or rolls are subsequently defiberized using a hammermill or a pin defiberizer to form fluff. Typical products made from fluff are diapers, feminine hygiene products and incontinence products. Fluff can also be used to produce various air laid absorbent pads and paper products.
Softness is a tactile sensation perceived by the consumer holding a particular product, rubbing it across the skin or crumpling it within the hand. Softness comprises two components, bulk softness and surface softness. Bulk softness relates to how easily the paper product flexes, crumples, or otherwise yields to even delicate counter-forces. Surface softness relates to how smooth or with how much lubricity the paper product can be slid against another surface. Both of these forms of softness can be achieved by mechanical means. For example, the sheet can be calendered to flatten the crests formed when creping the sheet and improve surface softness. Through-air-drying of the sheet improves bulk softness. However, mechanical approaches by themselves are often insufficient to meet consumer softness demands.
One way to make the paper softer is to add a softening compound to the cellulosic suspension. The softening compound interferes with the natural fiber-to-fiber bonding that occurs during sheet formation in papermaking processes. This reduction of bonding leads to a softer, or less harsh, sheet of paper. WO 98/07927 describes the production of soft absorbent paper products using a softener. The softener comprises a quaternary ammonium surfactant, a non-ionic surfactant as well as strength additives. The softening agent is added to the cellulosic suspension before the paper web is formed.
A softening compound can also be applied to a dry or wet paper web e.g. by means of spraying. If the paper web is dry, the softening compound can also be printed on the paper. U.S. Pat. No. 5,389,204 describes a process for making soft tissue paper with a functional polysiloxane softener. The softener comprises a functional-polysiloxane, an emulsifier surfactant and surfactants which are noncationic. The softener is transferred to the dry paper web through a heated transfer surface. The softener is then pressed on the dry paper web. WO 97/30217 describes a composition used as a lotion to increase the softness of absorbent paper. The composition comprises an emollient which is preferably a fatty alcohol or a waxy ester. The composition also comprises a quaternary ammonium surfactant as well as one or more non-ionic or amphoteric emulsifiers.
Most softening compounds, either added to the cellulosic suspension or applied directly to the paper web, contain quaternary ammonium surfactants. Since producers and consumers are experiencing a growing environmental concern, quaternary ammonium surfactants are not always accepted. The quaternary ammonium surfactants are generally toxic to aquatic organisms and are generally considered dangerous for the environment. The quaternary ammonium surfactants can be irritating to eyes and skin, and in some cases the irritation to eyes can be severe. Thus there is clear utility in compositions that debond and soften paper products that have less deleterious effects on the environment and have improved health profiles.
The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “Prior Art” with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 CFR §1.56(a) exists.
BRIEF SUMMARY OF THE INVENTION
At least one embodiment of the invention is directed to a method of softening a paper product. The method comprises: adding an effective amount of a composition to a mass containing cellulose fibers. The composition comprises at least one non-ionic surfactant and at least one cationic polyelectrolyte polymer coagulant. The polyelectrolyte polymer coagulant is characterized in having an overall cationic character and which can form stable emulsions with the nonionic surfactant. The composition effectively de-bonds the cellulose fibers.
The polyelectrolyte polymer coagulant may have anionic regions within the overall cationic polymer. The at least one cationic polymer may be a poly(DADMAC). The at least one polymer may be an epi-DMA polymer. The cationic polymer may have a low or high molecular weight. The composition may create a complex that prevents bonding interactions between the cellulose fibers. The composition may improve surface softness. The paper product may be tissue paper. The mass may be paper slurry. The composition may be an aqueous solution added to paper slurry. The composition may be sprayed onto the surface of the mass. The composition may be non-toxic.
Additional features and advantages are described herein, and will be apparent from, the following Detailed Description.
DETAILED DESCRIPTION OF THE INVENTION
The following definitions are provided to determine how terms used in this application, and in particular how the claims, are to be construed. The organization of the definitions is for convenience only and is not intended to limit any of the definitions to any particular category.
“Coagulant” means a composition of matter which is cationically charged and includes one or more organic based coagulants, or one or more inorganic based coagulants, and/or any combination and/or blend thereof, which destabilizes and initially aggregates colloidal and/or finely divided material suspended in a liquid.
“Epichlorohydrin-Dimethylamine Polymer” means a copolymer of epichlorohydrin and dimethylamine also referred to as epi-DMA polymer. The epi-DMA polymer may be crosslinked, for example with ammonia. The epi-DMA has a weight average molecular weight between 1000 and 1,000,000; preferably between 10,000 and 800,000; and most preferably between 100,000 and 600,000 Da.
“High molecular weight polymer” means a polymer having an average molecular weight greater than 1,000,000 Daltons.
“Inorganic Based Coagulant” means a coagulant which is predominantly inorganic including but not limited to alum, partially neutralized aluminum salts such as polyaluminum chlorides, ferric salts such as chloride and sulfate, and polymers thereof.
“Low molecular weight polymer” means a polymer with an average molecular weight of less than 250,000 Daltons.
“Medium molecular weight polymer” means a polymer having an average molecular weight in the range from 250,000 to 1,000,000 Daltons.
“Nonionic Surfactant” means a non-charged surfactant which includes but is not limited to alkanolamides, alkoxylated alcohols, amine oxides, ethoxylated amines, alkoxylated amides, EO-PO-block copolymers, alkoxylated fatty alcohols, alkoxylated fatty acid esters, alkylarylalkoxylates, sorbitan derivatives, polyglyceryl fatty acid esters, alkyl(poly)glucosides, fluorocarbon-based surfactants, and any combination thereof. Nonionic Surfactants typically have an HLB range between 3 and 18 with a preferred range between 4 and 14.
“Organic Based Coagulant” means a coagulant which is predominantly organic and which includes but is not limited to epichlorohydrin/dimethylamine polymers (epi-DMA) including crosslinked versions, ethylene dichloride/ammonia polymers, ethyleneimine polymers (PEI), diallyldimethylammonium chloride polymers (p-DADMAC), acrylamidopropyltrimethyl ammonium chloride polymers, polyamidoamines, amidoamine-epichlorohydrin polymers, copolymers of DADMAC and acrylamide, copolymers of DADMAC and acrylic acid (polyampholytes—as long as net charge is cationic), polyvinylamines. hydrolyzed N-vinylformamide polymers, polyamines, modified PEI (polyamidoamines grafted with PEI), and 2-cyanoguanidine based polymers including combinations with formaldehyde, urea and melamine.
“Poly(DADMAC) means a homopolymer of diallyldimethylammonium chloride (DADMAC). The monomer DADMAC is formed by reacting two equivalents of allyl chloride with dimethylamine. The pDADMAC has a weight average molecular weight between 1000 and 3,000,000; preferably between 25,000 and 2,000,000; and most preferably between 100,000 and 1,500,000 Da. A low molecular weight p-DADMAC has a weight average molecular weight less than 250,000 Da. A medium molecular weight p-DADMAC has a weight average molecular weight in the range from 250,000 to 1,000,000 Da. A high molecular weight p-DADMAC has a weight average molecular weight greater than 1,000,000 Da.
“Polyelectrolyte” means a polymer whose repeating units bear an electrolyte group.
“Surfactant means a composition of matter characterized in being a surface active agent having an amphiphilic structure which includes a hydrophilic head group and a hydrophobic tail group and which lowers the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid.
In the event that the above definitions or a description stated elsewhere in this application is inconsistent with a meaning (explicit or implicit) which is commonly used, in a dictionary, or stated in a source incorporated by reference into this application, the application and the claim terms in particular are understood to be construed according to the definition or description in this application, and not according to the common definition, dictionary definition, or the definition that was incorporated by reference. In light of the above, in the event that a term can only be understood if it is construed by a dictionary, if the term is defined by the Kirk - Othmer Encyclopedia of Chemical Technology, 5th Edition, (2005), (Published by Wiley, John & Sons, Inc.) this definition shall control how the term is to be defined in the claims.
The present invention relates to methods and compositions that soften paper products and in particular tissue products. In at least one embodiment a composition is provided which comprises a combination of nonionic surfactants and cationic polymers formulated to provide an easy to use, stable, liquid product. This composition is both effective at softening paper products and has a superior environmental profile when compared with prior art cationic surfactants.
In at least one embodiment the composition comprises a blend of nonionic surfactants and cationic polymers, which does not need to be labeled with an R-phase (risk phrase) according to the European Union's (EU) MSDS system as being very toxic, toxic, harmful, or cause long-term adverse effects in the aquatic environment. This includes both singular risk phrases such as R50, R51, R52, and R53, as well as the multiple risk phrases such as R50/53, R51/53, and R52/53. In at least one embodiment the composition need not be labeled with an “N” code and therefore can be packaged and sold in the EU without a dangerous for the environment, dead tree, or dead fish logo on it.
In at least one embodiment the nonionic surfactant is any surfactant which is nonionic, and which is sufficiently hydrophobic so as to effectively de-bond the cellulose fibers used in making tissue paper or other paper products. In at least one embodiment the cationic polymer is a polyelectrolyte, which may have anionic regions but which has an overall cationic character and which can form stable emulsions with nonionic surfactants.
In at least one embodiment the cationic polymer is a poly(DADMAC) polymer of high molecular weight (such as 8108+ by Nalco Company, Naperville Ill.), of intermediate molecular weight (such as 74316 by Nalco Company), of low molecular weight (such as 74696 by Nalco Company), and any combination thereof.
EXAMPLES
The foregoing may be better understood by reference to the following examples, which are presented for purposes of illustration and are not intended to limit the scope of the invention.
Example 1
In this example the preparation of softener formulations utilizing several cationic coagulants and a non-ionic surfactant is demonstrated. For softener Formulation 1, eight parts of an oleic acid polyglycol ester (Rewopol® EO 70) (available from Evonik Industries) was added to 82 parts of distilled water while stirring. Next, 10 parts of p-DADMAC (Nalco 8108 PLUS) was added to this dilute mixture with additional stirring. Formulation 1 was a stable macro-emulsion having a milky to slightly yellow appearance and a viscosity of 100 mPa·s at 25° C. Similarly for Formulation 2, eight parts of Rewopol® EO 70 was added to 82 parts of distilled water while stirring. Ten parts of p-DADMAC (Nalco 74316) was added to the dilute mixture with additional stirring. Formulation 2 was stable and had a milky to slightly yellowish macro-emulsion appearance with a viscosity of 100 mPa·s at 25° C. Finally for Formulation 3, eight parts of Rewopol® EO 70 was added to 89.5 parts of distilled water while stirring. Next 2.5 parts of p-DADMAC (Nalco 74696) was added to the dilute mixture with additional stirring. Formulation 3 was stable and had a milky to slightly yellowish macro-emulsion appearance with a viscosity of 100 mPa·s at 25° C.
Example 2
In this example the preparation of a second example formulation is demonstrated. An epi-DMA coagulant (Nalco 7607 Plus) was added to an equal quantity of distilled water while stirring. Next, 33.8 parts of this blend was added to 66.2 parts of an oleic acid polyglycol ester (Rewopol® BO 90) (available from Evonik Industries). This produced a stable product dispersion called Softener Formulation 4 that had a yellowish turbid appearance and a viscosity of approximately 1500 mPa·s at 25° C.
Example 3
Softener Formulations 1, 2 and 3 prepared in Example 1 were evaluated in handsheet studies to determine the amount of tensile strength loss they produced compared to industry standards Arosurf® PA 777V and Arosurf® PA 842V (available from Evonik Industries). Handsheets were produced using a Rapid-Kothen former according to ISO Procedure 5269-2. The furnish was a 50/50 blend of hardwood and softwood dry lap pulp. The softener formulations were added to the furnish at doses of 1, 3 and 5 kg/MT of dry fiber. The diameter of the sheets was 21 cm and the corresponding sheet weights were approximately 1.25 grams resulting in a basis weight of approximately 36.1 g/m 2 . The sheets were conditioned under standard recommendations for temperature and humidity (TAPPI Method T 402) and evaluated for tensile strength following TAPPI Method T 220.
The results are provided in Table I. The industry standard products Arosurf® PA 777V and 842V provide good debonding of the handsheets as determined by the measured loss in tensile index. A loss in tensile index correlates to an increase in bulk softness of the sheets. Similarly, the Product Formulations 1, 2, and 3 of Example 1 all showed a loss in tensile index compared to the Blank sheet used as a control. The industry standard products Arosurf® PA777V and 842V have R-phrase labeling of R50/53 and danger symbol showing a dead tree and fish. The Product Formulations 1, 2, and 3 would not have the R50153 phrase or the danger symbol.
TABLE I
Conditions and tensile index values for Example 3.
Average
Tensile Index
Loss in
Condition
Dose
(Nm/g)
Tensile (%)
Blank
0
17.3
—
PA 777V
1
12.7
26.6
PA 777V
3
8.1
53.2
PA 777V
5
6.7
61.3
PA 842V
1
12.7
26.6
PA 842V
3
9.1
47.4
PA 842V
5
8.3
52.0
Formula 1
1
9.6
44.5
Formula 1
3
14.5
16.2
Formula 1
5
10.7
38.2
Formula 2
1
14.2
17.9
Formula 2
3
12.7
26.6
Formula 2
5
11.5
33.5
Formula 3
1
16.5
4.6
Formula 3
3
9.8
43.4
Example 4
Softener Formulations 1, 2 and 3 from Example 1 were tested again in a second handsheet comparison to industry standards Arosurf® PA 777 and 842. Additional control experiments were also conducted to evaluate the effects of the individual components of the formulation. Rewopol EO 70 is an oleic acid polyglycol ester available from Evonik Industries. Nalco 8108 Plus is a high molecular weight p-DADMAC product available from Nalco Company. Handsheets were produced using a Messmer Model M 153 former according to TAPPI Method T205. The furnish was a 70/30 blend of hardwood and softwood dry lap pulp. The softener formulations were added to the furnish at doses of 1, 3 and 5 kg/MT of dry fiber. The diameter of the sheets was 15.9 cm and the corresponding sheet weights were approximately 1.0 gram resulting in a basis weight of approximately 60 g/m 2 . The sheets were conditioned under standard recommendations for temperature and humidity (TAPPI Method T 402) and evaluated for tensile strength following TAPPI Method T 220.
Tensile results are tabulated in Table II and again show that the industry standard products, Arosurf® PA 777V and 842V provided good debonding of the sheets. Oppositely, the nonionic surfactant, Rewopol E0 70, and the cationic coagulant, 8108 Plus, when dosed by themselves, provided minimal or no debonding of the sheets. However, when the individual nonionic surfactant and cationic coagulant components were combined together as in Softener Formulations 1, 2 and 3 then significant tensile index reductions occurred, thus demonstrating the utility of present invention.
TABLE II
Conditions and tensile index values for Example 4.
Average
Tensile Index
Loss in
Condition
Dose
(Nm/g)
Tensile (%)
Blank
0
18.3
—
PA 777V
1
15.9
12.9
PA 777V
3
8.3
54.6
PA 777V
5
7.4
59.7
PA 842V
1
14.0
23.4
PA 842V
3
10.5
42.5
PA 842V
5
7.1
61.5
EO 70
1
18.6
−1.5
EO 70
3
17.5
4.4
EO 70
5
17.5
4.6
8108 Plus
1
16.5
9.9
8108 Plus
3
16.4
10.4
8108 Plus
5
16.4
10.7
Formula 1
1
16.4
10.6
Formula 1
3
11.0
40.1
Formula 1
5
9.7
46.8
Formula 2
1
15.1
17.3
Formula 2
3
9.6
47.4
Formula 2
5
11.8
35.6
Formula 3
1
16.5
9.6
Formula 3
3
12.5
31.6
Formula 3
5
6.2
66.2
Example 5
In this example Softener Formulation 4 was compared to industry standard products Arosurf® PA 777 and Rewoquat® WE 15 DPG (available from Evonik Industries) in handsheet debonding experiments. Handsheets were produced using a Messmer Model M 153 former according to TAPPI Method T205. The furnish was a 50/50 blend of hardwood and softwood dry lap pulp. The softener formulations were added to the furnish at doses of 1, 3 and 5 kg/MT of dry fiber. The diameter of the sheets was 15.9 cm and the corresponding sheet weights were approximately 1.9 gram resulting in a basis weight of approximately 100 g/m 2 . The sheets were conditioned under standard recommendations for temperature and humidity (TAPPI Method T 402) and evaluated for tensile strength following TAPPI Method T 220.
Tensile results are tabulated in Table III and again show that the industry standard products, Arosurf® PA 777V and Rewoquat® WE 15 DPG provided good debonding of the sheets. Formulation 4 provided equally good debonding, evidenced by the similar loss of tensile strength in the sheets compared to the industry standard products.
TABLE III
Conditions and tensile index values for Example 5.
Average
Tensile Index
Loss in
Condition
Dose
(Nm/g)
Tensile (%)
Blank
0
18.9
—
PA 777V
1
15.8
16.4
PA 777V
3
9.4
50.3
PA 777V
5
8.0
57.9
Rewoquat WE 15
1
16.4
13.4
DPG
Rewoquat WE 15
3
11.1
41.3
DPG
Rewoquat WE 15
5
8.0
57.7
DPG
Formula 4
1
17.1
9.8
Formula 4
3
10.4
45.1
Formula 4
5
7.7
59.1
The data demonstrates that nonionic surfactants and cationic polymers when used alone have little effect on tensile strength. Their combination however demonstrates a marked and completely unexpected synergistic effect, which decreases tensile strength of paper products to levels comparable with more toxic compositions currently commonly used in the tissue-making industry.
Without being limited in theory and the scope afforded in construing the claims, it is believed that the synergistic composition better attaches de-bonding materials than the prior art can. Cellulose fibers are anionic so they naturally repel anionic compositions, which would otherwise effectively debond them. In the invention, the cationic polymers and surfactants create a complex, which is attracted to the fiber surface and thereby prevents fiber-fiber bonding interactions.
This invention provides unexpectedly good results by using a simple two component formulation and does not contain an anionic component, compared to other prior art de-bonding compositions having four components and containing at least one anionic component. For example WO 2006/071175 and WO 2007/058609 both disclose compositions containing at least four components and containing at least one anionic component selected from anionic surfactants and anionic microparticles. In at least one embodiment the composition excludes having any one anionic component. In at least one embodiment the composition excludes a four (or more) component formulation of the composition.
While this invention may be embodied in many different forms, there are described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. All patents, patent applications, scientific papers, and any other referenced materials mentioned herein are incorporated by reference in their entirety. Additionally, the invention also encompasses any possible combination of some or all of the various embodiments described and incorporated herein. Furthermore the invention also encompasses combinations in which one, some, or all but one of the various embodiments described and/or incorporated herein are excluded.
The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
All ranges and parameters disclosed herein are understood to encompass any and all subranges subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, (e.g. 1 to 6.1), and ending with a maximum value of 10 or less, (e.g. 2.3 to 9.4, 3 to 8, 4 to 7), and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range.
This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
|
Methods and compositions for softening paper. An inventive composition and method of its use softens paper products (like tissue paper) by de-bonding its cellulose fibers and by improving the smoothness of the resulting paper. The invention forms a surfactant-polymer complex that attaches de-bonding non-ionic surfactants to cellulose fibers that would otherwise not be retained by the cellulose fibers. This complex prevents the fibers from bonding with each other and makes the paper product smoother. Best of all, the composition is environmentally superior and is a non-toxic.
| 3
|
BACKGROUND OF THE INVENTION
The invention relates to a solenoid membrane valve for controlling and/or regulating the flow of liquid media, which valve comprises a membrane fixedly clamped in a valve housing, and an armature frictionally connected with the membrane.
Particularly, in the case of fuel injection systems, it is required to intervene in an automatic control circuit by means which are inexpensive to manufacture, but operate accurately, in order to change the proportions prevailing in the circuit. In a fuel injection system, such change will be in the proportionality of the aspirated amount of air and the injected amount of fuel. This proportionality is changed in dependence on engine data, such as rpm, load, temperature and composition of the exhaust gases, in order to combust the fuel as completely as possible, thereby avoiding or strongly reducing the formation of toxic exhaust gases, while maintaining the greatest possible efficiency of the internal combustion engine and a minimum of fuel consumption. As in the case of many other control systems with similar requirements, it has been found in such automatic fuel injection control systems that liquid is a highly suitable control medium owing to its non-compressibility with preservation of its fluid properties.
Especially when using electrical means for measuring the amount of air or metering the amount of fuel, a solenoid valve is usually an important element of the control system, a magnetically controlled membrane valve having a flat seat being preferred as such element. Apart from the fact that such a valve operates practically free from hysteresis, its flat seat with the cross-sectional area of its annular valve passage produces at short strokes a linear relationship between the stroke of the membrane and the cross-sectional area of the flow passage.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a novel valve of the aforementioned type, in which the above-described requirements are fulfilled better than in the known valves, which novel valve is, in particular, less expensive to manufacture.
This and other objects are attained according to the invention by providing a valve of the type described, wherein the armature of the solenoid is arranged on that side of the membrane which faces away from the exciting coil and from the magnetic core of the solenoid, whereby the magnetic flux flows through the membrane, especially for the control of the flow of liquids which serve as control means in a fuel injection system. According to a feature of the invention, the armature is pressed against the membrane by the magnetic flux flowing through the membrane. In known valves, the armature of the magnet is affixed to the membrane, thereby causing a change in the shape of the latter, which change will have a negative effect on the control of the medium. A further advantage of the novel valve according to the invention resides in its small size, and, if necessary, in the easy separability of the space containing the exciting coil from the control space.
In an advantageous embodiment of the invention the armature serves at the same time as a spring retainer of a control spring, being preferably manufactured from soft-magnetic material and having the shape of a cup, and encircling a sleeve which bears the valve seat. According to another advantageous embodiment of the invention the armature is mounted and radially guided on a guiding membrane. The armature is suspended to be axially displaceable and free from friction, preferably by means of a rolled flange portion. Thereby mechanical friction which would automatically lead to hysteresis is avoided. In this case the guiding membrane is made in a known manner of axially soft and radially rigid material. The guiding membrane can be axially attachable by means of a soft-iron ring of the same diameter which axially engages in the stator bore. Thus no additional dividing plane of the housing is needed for clamping-in the guiding membrane and the frontal face of the casing turned toward the membrane can be lapped in a single working step. A narrow radial play is provided between the soft-iron ring and the armature-spring retainer, in order to ensure minimum losses of magnetic flux. The soft-iron ring can be provided, on the side thereof facing away from the membrane, with an inner flange and the armature-spring retainer can be provided with an outer flange which extends beyond that side of the inner flange of the soft-iron ring which faces away from the membrane. This prevents the formation of unilateral radial forces due to eccentricity of the spring retainer in the soft-iron ring, resulting from manufacture thereof. Otherwise, such radial forces could effect a tilting of the spring retainer and may even cause magnetic adhesion during contact of the spring retainer and the soft-iron ring; also, avoidance of such radial forces affords the advantage of an additional axial power gain. Moreover, the guiding membrane can serve advantageously for controlling the magnetic flux, for which purpose it is preferably made of soft-magnetic material having a high saturation inductance. In this case, no additional and uncontrolled magnetic radial and/or axial forces will be exerted on the spring retainer.
It is important that valves of this type should be constructed of small radial extensions, so that they may be integrated readily into other control units. Furthermore, the clamped-in diameter of the membrane should be as small as possible, in order to keep the magnetic forces small, when, for example, different pressures prevail on the two sides of the control membrane, for the force of the membrane increases proportionally with the second power of the clamped-in diameter of the control membrane, and the diameter of the guiding membrane is largely dependent on the diameter of the control membrane. According to the invention, the head of the spring retainer should have the smallest possible diameter, and to this end, the control spring can be supported by the spring retainer in a range which is located, taken from the control membrane, axially behind the guiding membrane.
According to a further advantageous embodiment of the invention, the armature-spring retainer is axially displaceable and radially guided in the housing. In this case, it is important that there should be only a minimal clearance between the two members being displaceable relative to one another. In order to avoid any magnetic adhesion, the surfaces of members facing towards each other, through which the magnetic flux passes, can be coated with a non-magnetic material. In order to reduce expenses, a ring of soft-magnetic material, affixed to the housing, can be arranged between the armature-spring retainer and the housing, across which a locally large magnetic flux density is possible. The casing on the contrary, can be manufactured from less expensive material, since the magnetic flux density therein is smaller. In order to avoid a magnetic short circuit, the control spring, a tubular socket, or a casing part containing the socket, may consist of non-magnetic material. Washers made of non-magnetic material may also be used, provided their magnetic resistance is sufficient.
For some control purposes it is necessary that different pressures should prevail on both sides of the membrane. Therefore, according to the invention, the chambers on both sides of the membrane may be in communication with each other, preferably by way of a throttle bore. When a given pressure prevails in one chamber, this throttle bore brings about a constant pressure drop in the direction toward the other chamber. In addition, in accordance with the invention, oscillations of constant, small amplitude and constant frequency can be superimposed on the applied basic operating current, in order to eliminate the occurrence of adhesion hysteresis.
The invention will be better understood, and further objects and advantages will become apparent from the ensuing detailed specification of a preferred but merely exemplary embodiment taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows in axial view a preferred embodiment of the solenoid membrane valve according to the invention, and
FIGS. 2 to 4 show in partial sectional view variations of the armature of the valve shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In a multiple-part housing of a solenoid membrane valve, a membrane 3 is clamped between the housing elements 1 and 2. Housing element 2 is closed by means of a top 4, and has a central bore 2a into a threaded portion 2b of which a magnetic core 5 having an external thread and bearing a plug portion 6 is screwed in position. About plug 6 an exciting coil 7 is affixed to core 5. The free end face 6a of plug 6 determines the maximal stroke of the membrane 3. In the central bore 1a of housing element 1, which registers with central bore 2a, there is affixed an insert 8 which is preferably manufactured from magnetically non-conductive material. In the central bore 8a of insert 8, there is seated a valve sleeve 9 whose reduced diameter portion 9a facing toward membrane 3 constitutes a valve seat 10. A coil spring 11 serving as a control spring and surrounding sleeve portion 9a, is seated with its one end on the inside face 8b of insert 8 and with its other end in a cup-shaped spring retainer 12, thereby urging the latter into contact with membrane 3. The cup-shaped spring retainer 12 serves as the armature of solenoid 7.
In the embodiment shown in FIG. 1, armature 12 is fixedly mounted in the central opening 13a of a guiding membrane 13, which is clamped between two rings 14 and 15 inserted fixedly into the central bore 1a of housing element 1. The cup-shaped armature 12 has an outer flange 16 which reaches over an inwardly extending flange 17 of ring 14, in order to provide particularly favorable flux-transmitting surfaces for the magnetic flux in the axial direction. Furthermore, there are provided in ring 14 axial bores 18, through which fuel flows in its passage past seat 10, to fill the entire space 30 of the housing even when flange 16 is in contact with flange 17. In this embodiment, a higher fuel pressure prevails in chamber 30a of interior space 30 which is surrounded by element 2 than in chamber 30b which is enclosed by elements 1 and 8. A constant pressure drop between the two chambers 30a and 30b which are separated by the membrane 3, is caused by a throttle 19 through which fuel continually flows from chamber 30a into chamber 30b. Moreover, a larger amount of fuel flows through chamber 30a from entry bore 2d to exit bore 2c as indicated by arrows in order to effect a cooling of the exciting coil 7. From chamber 30b the liquid passing through throttle 19 then flows either past the valve seat 10 and out of discharge bore 8c to another control pressure valve (not shown), whenever armature 12 (along with membrane 3) is attracted by solenoid 7; or, pressure-regulated, via axial duct 18, orifices 13b in guiding membrane 13 into discharge bore 20 in element 1 to a fuel-consuming device. Depending on which current intensity and/or current frequency is applied to the exciting coil 7, the stroke of membrane 3 can correspond to the applied current intensity (proportional actuation), or the membrane can be operated in cycles carrying out a full stroke in each cycle (integral actuation). In either case, the difference between the pressures prevailing on both sides of the membrane is thus controlled.
The magnetic core 5 has a bore 31 formed therein. The bore 61 serves as a connecting bore for the chamber 30a to the space 32 between the core 5 and the cover 4.
In the embodiment shown in FIG. 2, the magnetic flux does not pass via a special annular member as provided by annular flange 17 in the preceding embodiment, but, instead, via the guiding membrane 13 which is manufactured from suitable soft-magnetic material, and has an adequate cross-sectional area.
A ring 21, by means of which the guiding membrane 13 is fixedly held on ring 15 is preferably manufactured of soft-magnetic material in order to facilitate the passage of the densified magnetic flux from housing element 1 to the guiding membrane.
In contrast to the magnetic system shown in FIG. 1, the magnetic system shown in FIG. 3 comprises a cup-shaped armature 22 of much smaller diameter, thus avoiding the need for too large an electromagnet even in the case of larger differences occurring between the pressures on both sides of membrane 3, as the required control forces increase with the square of the membrane diameter. The smaller diameter of armature 22 is made possible by supporting control spring 11 in this embodiment on a shoulder 23 in the armature cup rim 22a facing away from membrane 3 and beneath the cup zone in which the guiding membrane 24 engages armature 22, rather than having the spring located inside the cup of the armature as is the case in the embodiment of FIG. 1. In order to maintain an adequately soft characteristic spring curve, the length of control spring 11 must not be shortened, wherefor the valve sleeve 31 is slightly longer than the valve sleeve 9 of the embodiments shown in FIGS. 1 and 2, but has a much smaller diameter. Radial bores 25 are provided in the armature for the flow of fuel therethrough.
In the embodiment of the magnetic system shown in FIG. 4, the cup-shaped armature 26 is inserted in a soft-iron ring 27 which is provided with grooves 28 for fuel flow in the wall of its central bore 27a. A coating 29 of non-magnetic material is provided on the outer cup surface of the armature 26 facing ring 27. Thereby, magnetic adhesion due to one-sided compression of the spring 11, and the resulting eccentric positioning of the armature, can be avoided.
According to the invention, a coating of non-magnetic material may be provided advantageously on all surfaces which must undergo displacement, relative to each other, in order to avoid magnetic adhesion. All other members which are not important for the magnetic flux can be made from less expensive non-magnetic material.
|
A magnetically-actuated membrane valve for controlling and/or regulating the flow of a liquid medium is described which valve comprises a control membrane fixedly clamped in a valve housing, and an armature frictionally connected with the membrane, which armature is arranged on that side of the membrane which faces away from the exciting coil and from the magnet core of the solenoid, whereby the magnetic flux flows through the membrane, especially for the control of the flow of a liquid which serves as control means in a fuel injection system.
| 5
|
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of co-pending application Ser. No. 656,951, filed Feb. 19, 1991, now U.S. Pat. No. 5,125,910, entitled "Surgical Endoscopic Suction/Irrigation Cannula Assembly", and assigned to the same assignee as the present application.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The invention relates to a surgical endoscopic suction/irrigation cannula assembly including a valve actuator.
(2) Brief Description of the Prior Art
Surgical endoscopic procedures typically follow three steps. First, a cannula, such as a Veress cannula, is inserted into the abdominal cavity through the abdominal wall and the cavity is inflated with insufflating gas which is passed through the cannula tubular housing. After insufflation, a small incision is made in the skin and a standard trocar spike is thrust into the inflated abdomen through the bore of the trocar tube. The spike is inserted for purposes of puncturing or cutting of the abdominal wall and piercing the fascio and peritoneum inside the cavity. After removal of the spike, a suction/irrigation cannula is inserted through the trocar housing and into the opening so that fluids may be drained from the body cavity.
Endoscopic surgery also includes the introduction through a trocar tube of a number of auxiliary surgical instruments such as, for example, a laparoscope, or the like. Heretofore, in many surgical instances, endoscopic surgery procedures have been performed through the trocar tubular housing by sequential insertion and removal of surgical instruments as they are needed. As the surgery is performed using such instruments, many situations require concurrent introduction or removal of gaseous or liquid fluid materials immediate the area of the surgery. Thus, removal of the surgical instrument from the body cavity through the trocar tubular housing and reinsertion through the trocar housing of a device for transmission of the gaseous or liquid substance not only complicates the surgical procedure, but is also time consuming and may introduce unforeseeable consequences to the surgical operation.
Endoscopic surgery is a very fine art, demanding extremely controlled movements of the surgeon's hand in the operation of the surgical instruments through the trocar housing. Therefore, any valves or other components which are required to be manually manipulated by the surgeon must be extremely sensitive and manipulatable in direct response to a very minor application of pressure or movement of the surgeon's hand or finger.
In copending application Ser. No. 656,951, filed Feb. 19, 1991, now U.S. Pat. No. 5,125,910, and entitled "Surgical Endoscopic Suction/Irrigation Cannula Assembly", and assigned to the same assignee as the present invention, there is shown and disclosed a "trumpet"--like valve assembly and cannula for use in irrigation/suction techniques for endoscopic surgery. The present invention is provided in order to enhance the sensitivity of such a device to hand manipulation by the surgeon and to afford the surgeon a positive "feel", indicative of the movement of the valve to the open position. Accordingly, the invention permits the introduction or removal of fluid to or from the body cavity during surgery by activation with only a minor amount of pressure through the surgeon's finger and provides a positive indication, transmittable through the device and the operating finger of the surgeon, indicative of the positioning of the valve head to open a fluid flow passageway.
The present invention also provides for introduction or removal of fluid from the body cavity during surgery through the cannula housing through which an auxiliary device may be inserted at any time during the surgery without removal of the valve actuator device. Thus, an auxiliary endoscopic instrument may be utilized concurrently with the device of the present invention to introduce and/or remove gaseous or liquid fluids from the body cavity during the surgical operation.
SUMMARY OF THE INVENTION
The present invention provides a positive touch surgical endoscopic cannula assembly, as well as a valve actuator assembly for incorporation onto an endoscopic surgical instrument in which gas or liquid is to be introduced and/or removed from a body cavity during surgery. An elongate tubular housing has a first open end for introduction into the body cavity during surgery, and an opposite second open end. A valve actuator assembly is carried on the tubular housing through the second open end with the valve actuator assembly including an actuator housing. At least one valve chamber is provided within the actuator housing. A valve head member is movable between first and second positions and housed within the chamber. A valve seat is defined in the chamber for selective sealing receipt of the valve head when the valve head is in the first position. Biasing means, such as a spring, are provided within the chamber for urging the valve head toward the first position. A manually operable valve head controller is carried on the housing for overcoming the bias of the biasing means and moving the valve head toward the second position. A conically shaped flexible force resistor means has a normal non-inverted state as well as an inverted state and is spaced in the chamber between the housing and the head controller. The resistor means resists movement of the controller in one direction when in the normal state and is at least partially invertible in response to movement of the valve head controller and movement of the valve head toward the second position, whereby movement of the resistor to the partially inverted state will terminate resistance upon movement of the valve head controller. A fluid passageway is included in the chamber and extends within the actuator housing and through the elongate tubular housing. A port is disposed through the actuator housing and is in fluid communication with the chamber for receiving a fluid transmitting means for directing fluid into or out of the tubular housing through the chamber.
In an alternate preferred embodiment, an assembly is provided in which ports are disposed through the lower most portion of the actuator housing which are, in turn, in fluid communication with a fluid chamber upstream of a valve head which is normally biased toward its sealing valve seat. In such configuration, the valve will always remain closed regardless of the exposure of the device to increased pressures. In other words, the more pressure which is received through the ports, the more the valve heads are urged into sealing engagement with the valve seat.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the surgical endoscopic cannula assembly introduced through a trocar housing and held in the hands of a surgical operator.
FIG. 2 is a partial sectional view through the valve actuator assembly with the valve members therein being in closed position.
FIG. 3 is a view similar to that of FIG. 2 showing one of the valve members in the actuator being opened for passage of fluid therethrough.
FIG. 4 is a view similar to that of FIGS. 2 and 3, showing the other of the valve members in the actuator being opened and the first valve member being closed for transmission of another fluid therethrough.
FIG. 5 is a view similar to that of FIG. 3, but illustrating the alternate preferred embodiment of the present invention.
FIG. 6 is a view similar to that of FIG. 4, illustrating the alternate preferred embodiment with the other of the valve members in the actuator being opened and the first valve member being closed for transmission of another fluid therethrough.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, with first reference to FIG. 1, there is shown the surgical endoscopic cannula assembly 100 of the present invention disposed through an elongate tubular cannula housing 10 and held in such position prior to use during surgery and introduction through a body cavity by means of application of a surgeon's fingers F while the surgeon's thumb T on hand H grasps the end of a valve actuator assembly 20.
An elongate tubular housing 32 of the actuator assembly 20 is shown extending through the outboard-most open end 10a of the cannula housing 10, with the elongate tubular housing 32 having a first open end 32a with transverse ports 32c intermediate the open end 32a.
As shown in FIG. 1, plural fluid hoses FHa, FHb are secured to the valve actuator assembly 20 through respective ports 46a, 46b, with the hoses FHa, FHb, extending to a body of pressured fluid for introduction through the actuator assembly 20 and the housing 32 and into the body cavity during surgery, and/or to a vacuum generating means for removal of fluid, by suction, through the open end 32a, thence through the housing 32 and into the actuator assembly 20, during the surgical operation.
Now referring to FIG. 2, there is shown the valve actuator assembly 20 of the present invention with plural valve assemblies therein. The actuator is defined by an exterior actuator housing 21 having a lower body member 21a for sealing receipt of the second open end 32b of the elongate tubular housing 32.
With continued reference to FIG. 2, the valve actuator assembly 20 includes within the housing 21 first and second valve head spherical members 22a, 22b, which are biased by means of respective springs 23a, 23b, toward a companionably contoured valve seat portion 21d, 21e, on the housing 21.
A finger or thumb activated controller 24a, 24b is provided for each of the valve heads 22a, 23b. The controllers 24a, 24b have respective extensions 25a, 25b extending within the housing 21 and inner extending end 26a, 26b extending within a passage 21b, 21c through the top of the housing 21. The ends 26a, 26b extend to the outer surface of the respective valve head 22a, 22b.
Extending around the exterior of the respective end elements 26a, 26b and within the housing 21 are first and second force resistors 27 and 28. The force resistors are of an elastomeric rubber-like material and are normally conically shaped, each having an upper cone portion 27a, 28a extending to a lower outwardly extending conical skirt portion 27b, 28b, with the lower end of the respective skirt portions 27b, 28b being carried on the housing 21 at the uppermost end of the valve seat portion 21d, 21e above the respective valve heads 22a, 22b.
Valve chambers 41a, 41b, are defined exteriorally around the respective valve head members 22a, 22b, interior of the actuator housing 21, and are always in communication through respective ports 46a, 46b with the respective fluid hose FHa, FHb.
Fluid passageways 45a (FIG. 3) is defined in the actuator assembly 20 and includes the valve chamber 41a when the valve seat 21d is sealingly away from its valve head 22a (FIG. 2). Likewise, a fluid passageway 45b (FIG. 4) extends from the fluid hose FHb by means of the port 46b through the chamber 41b when the valve head 23b is sealingly away from its valve seat 21e (FIG. 4). These fluid passageways 45a, 45b, may carry fluid in a form of a liquid in one or both of the fluid hoses FHa, FHb, for introduction into the actuator assembly 20 and the tubular cannula housing 10, and discharged through the open end 32a and the transverse ports 32c into the body cavity during surgery. Alternatively, one or both of the fluid passageways 45a, 45b, may provide a fluid vacuum passage extending to one or both of the fluid hoses FHa, FHb, for removal of fluid from the body cavity during surgery.
The actuator housing 21 also has a selectively openable port 47 opposite the opening in housing member 21a for receipt of the member 32, for introduction of an auxiliary device AD, such as a laparoscope, which may be concurrently utilized during the surgery in combination with the actuator assembly 20. As will be appreciated from the disclosure herein, and, particularly with respect to FIGS. 1 and 2, the auxiliary device AD may be introduced through the valve actuator assembly 20 and the elongate tubular cannula housing 10 and the tubular housing 32 of the assembly 100 while concurrently manipulating one or both of the valve head controllers 24a, 24b, to introduce or remove fluid during surgery.
The port 47 is always sealingly closed by means of a seal assembly comprising a first seal 48 and a second seal means 49. The first seal 48 has a concave curvature 48a and incorporates a lateral slit to accommodate entrance of the auxiliary device AD therethrough. When the auxiliary device AD is introduced through the assembly 20, as shown in FIGS. 2, 3 and 4, first and second seal means 49c and 49d will seal around the exterior of auxiliary device AD to prevent passage of fluid and pressure there across from the interior of the assembly 20, to the exterior thereof, through the port 47. Additionally, when the auxiliary device AD is not within the assembly 20, the seal means 48 prevents fluids from passing from the exterior to the interior, and vice versa.
OPERATION
When it is desired to perform endoscopic surgery, the cannula housing 10 is introduced through the body cavity and held by the surgeon, as shown in FIG. 1. The valve actuator assembly 20 may be introduced into the cannula housing 10 prior to introduction of housing 10 into the body cavity, or concurrently therewith, or subsequent thereto.
When it is desired to introduce or remove fluid to or from the body cavity, one or more of the valve head controllers 24a, 24b are manipulated to move the respective valve heads 22a, 22b, from sealing engagement with the respective valve seat 21d, 21e, by placing the thumb T or finger F of the hand H of the surgeon on the respective controller 24a and applying a downward slight force thereon and toward the interior of the housing 21. Accordingly, as force is applied through the controller 24a in such fashion, the end 26a will engage the valve head 22a to begin movement away from the valve seat 21d and sealing engagement relative thereto. Concurrently, the bias of the spring 23a will be overcome and the spring 23a will begin to compress.
Because of the elasticity and snug engagement of the force resistor 27 around the exterior of the end portion 26a, slight resistance to movement of the controller 24a by the thumb T or finger F will occur. As the controller 24a continues to be moved, the load on the flexible elastomeric force resistor 27 will cause a slight "inversion" of the conical shape thereof between the upper cone portion 27a and the conical skirt 27b such that the resistor 27 configuration inverts from the form shown in FIG. 2 to that in FIG. 3 (for controller 24a) or FIG. 4 (for controller 24b). When the "inversion" of the force resistor 27 is effected, load through the end 26a of the controller 24a will be immediately directly transferred to the valve head 22a without resistance and such immediate transfer can be felt through the thumb T or finger F of the surgeon through the controller 24a by a slight "snap" thrust movement through the controller 24a. Such an indication is reflective of the valve head 22a being moved to the open position.
The same sequential operation will be produced when the controller 24b is manipulated.
The auxiliary device AD may be inserted through the apparatus 100 either prior to subsequent to activation of the controller 24a, 24b, as described above.
Now with reference to FIGS. 5 and 6, there is shown an alternate preferred embodiment of the assembly 20, wherein like numbers are used for like parts. In such alternate preferred embodiment, it will be appreciated that the ports 46a, 46b are placed within the lower body member 21a and upstream of the respective spherical valve head members 22a, 22b, with the respective biasing means, or springs, 23a, 23b, also being placed upstream of the spherical members 22a, 22b. Additionally, the elongate tubular housing 32 is positioned through the assembly 20 and within the housing 21 and are downstream of the respective spherical valve heads 22a, 22b. Each of the inner ends 26a, 26b, extending from the controller 24a, 24b, is provided with a passageway 26aa 26bb which, when the valve heads 22a, 22b, are in sealing engagement on the valve seats 21d, 21e, provides full opening relative to the inner diameter of the elongate tubular housing member 32, such that auxiliary devices may be inserted therethrough. Each of the inner ends 26a, 26b of the respective controllers 24a, 24b have a solid tip end 26a', 26b' which contacts the upper surface of the respective valve head spherical member 22a, 22b, such that when the respective controller 24a, 24b is manipulated by the operator, the respective tip end 26a', 26b' will contact the outer upper surface of the respective valve heads spherical element 22a, 22b, to overcome the bias of the spring 23a, 23b, as well as the pressure within the chamber 41a, 41b through the port 46a, 46b, to manipulate the spherical 22a, 22b, away from the respective seat 21d, 21e, to open the fluid flow passageway between the chamber 41a, 41b, and the elongate tubular housing 32.
It will be appreciated that the inner diameter of the respective passageways 26aa, 26bb, through the inner ends 26a, 26b, is slightly larger than the inner diameter of the elongate tubular housing member 32 in order to provide full opening clearance through the members 26a, 26b, while the spherical members 22a, 22b, in the assembly 20 are manipulated from closed to opened position to permit fluid communication thereacross while having an auxiliary instrument housed within the assembly 20 and the elongate tubular housing 32. Thus, in the alternative preferred embodiment of the apparatus shown in FIGS. 5 and 6, the ports 46a and 46b are on the same side of the ball valve heads 22a, 22b as is the biasing means 23a, 23b, in other words, when the fluid passing through the lines FHa, FHb, and into the respective ports 46a and 46b is to be an irrigating liquid, the ports 46a, 46b and the biasing means 23a, 23b will be upstream with respect to the valve head members 22a, 22b, with respect to the direction of flow of fluid within the actuator 20. Likewise, the second opened end 32b of the elongate tubular housing 32 is "downstream" of the area of sealing engagement between the respective valve heads 22a, 22b, and the valve seats 21d, 21e.
Although the invention has been described in terms as specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.
|
A positive touch surgical endoscopic cannula assembly in which one, or both, of liquid or gas may be introduced or removed from a body cavity during surgery. The device contains a valving mechanism responsive to finger or thumb touch of the surgeon and having a conically shaped force resistor which is partially inverted during movement of the valve between open and closed positions. The partial inversion of the flexible resistor is detectable through an actuator to the hand or thumb of the operator to positively indicate positioning of the valve head and seat members.
| 0
|
CROSS REFERENCES TO RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 14/200,347, filed on Mar. 7, 2014, which is a continuation of U.S. patent application Ser. No. 13/754,373, filed on Jan. 30, 2013, and issued on Apr. 15, 2014, as U.S. Pat. No. 8,696,283, which claims priority to U.S. Provisional Patent Application No. 61/705,498 filed on Sep. 25, 2012, now abandoned, the disclosure of each of which is hereby incorporated by reference in its entirety herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a multi-piece weight screw with a retaining feature and a unidirectional torque transferring feature.
2. Description of the Related Art
In recent years, golf consumers have become more interested in customizing their golf equipment. As such, many manufacturers have begun incorporating adjustable features into their golf clubs. One such feature is weighting, which can be adjusted through the use of removable or movable weights, including weight screws, affixed to various regions of a golf club head or shaft. While there are several different kinds of golf club weight screws currently available on the market, many of these screws have structural weaknesses that can lead to breakage and thus require consumers to spend additional money replacing them. Furthermore, once a weight is removed there is the potential for the consumer to lose it, which is inconvenient for the golfer. As such, there is a need for a weight screw with an improved structure that prevents breakage and loss.
BRIEF SUMMARY OF THE INVENTION
One aspect of the present invention is a two piece weight screw that may be used to adjust the weight of a golf club head. The two part screw of the present invention separates the first, drive part, which may be Torx™, hex, Phillips, etc., from the second, threaded part. This screw further includes a mechanism for removably attaching the screw to an adjustment wrench, which may be a retaining ring that engages a specific geometry of the wrench. The retaining ring is disposed on the second part of the screw assembly, and preferably sits within a cavity in the second part where it cannot move in a vertical direction and has space to expand horizontally around its diameter. This cavity becomes an enclosed space when the first part of the screw assembly is assembled with the second part of the screw assembly.
Another aspect of the present invention is a torque transfer method. An interface surface is provided between the first and second parts of the screw assembly, and the interface of the present invention transfers the torque applied at the drive side in the first part of the screw to the threads of the second part of the screw without slipping.
Yet another aspect of the present invention is a screw comprising a drive part comprising a receiving cavity, a threaded part comprising a projecting portion and a pocket, and a retaining ring, wherein the drive part is formed separately from the threaded part, wherein the retaining ring is disposed in the pocket, and wherein the projecting portion is sized to mate with the receiving cavity. In some embodiments, the retaining ring is composed of a material selected from the group consisting of elastomeric material, metal material, and composite material, and in a further embodiment may be composed of steel. In other embodiments, the receiving cavity comprises a shape, which may be selected from the group consisting of circular, triangular, square, rectangular, oval, and hexalobular. In some embodiments, the receiving cavity may comprise a plurality of pins, the projecting portion may comprise a plurality of holes, and the plurality of pins may mate with the plurality of holes. In an alternative embodiment, the receiving cavity may comprise the plurality of holes and the projecting portion may comprise the plurality of pins.
In one embodiment, the pocket may have a first diameter, the retaining ring may have a second diameter, and the second diameter may be smaller than the first diameter. In another embodiment, the pocket may be sized to permit the retaining ring to expand in a horizontal direction and not a vertical direction. In some embodiments, the drive part may comprise a through bore, which may have hexalobular geometry. In some embodiments, torque applied to the drive part may be transmitted to the threaded part via the receiving cavity and the projecting portion. In another embodiment, the drive part may be composed of a first material, the threaded part may be composed of a second material, and the first material may be different from the second material. In some embodiments, the drive part may be composed of a material having a density of no less than 1 g/cc to and no more than 16 g/cc, and in other embodiments, the threaded part may be composed of a material having a density of no less than 2.5 g/cc and no more than 12 g/cc. In still other embodiments, the drive part may be composed of thixomolded magnesium material, and the threaded part may be composed of a different metal material.
Another aspect of the present invention is a weight screw comprising a drive part composed of a material having a density of no less than 1 g/cc to and no more than 16 g/cc, a threaded part formed separately from the threaded part composed of a material having a density of no less than 2.5 g/cc and no more than 12 g/cc, a receiving cavity, a projecting portion, a pocket, and a retaining ring composed of a metal alloy, wherein the retaining ring is disposed in the pocket, wherein the pocket is sized to permit the retaining ring to expand in a horizontal direction and not a vertical direction, and wherein the projecting portion is sized to mate with the receiving cavity. In some embodiments, the receiving cavity may be disposed on the drive part, the projecting portion and the pocket may be disposed on the threaded part, and the receiving cavity may have a hexalobular shape. Another embodiment may further comprise a plurality of holes and a plurality of pins that mate with the plurality of holes. In a further embodiment, the plurality of holes may be disposed on the receiving cavity and the plurality of pins may be disposed on the projecting portion.
Another aspect of the present invention is a set of weight screws or a kit comprising one or more of the weight screws described herein.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1A is a side perspective view of a first embodiment of the present invention.
FIG. 1B is a bottom perspective view of the embodiment shown in FIG. 1A .
FIG. 2 is a cross-sectional view of the embodiment shown in FIG. 1A along lines 2 - 2 .
FIG. 3A is a top perspective view of the drive part of the first embodiment.
FIG. 3B is a bottom perspective view of the drive part of the first embodiment.
FIG. 4A is a top perspective view of the threaded part of the first embodiment with a retaining ring.
FIG. 4B is a top perspective view of the threaded part of the first embodiment without a retaining ring.
FIG. 5 is a side perspective view of a second embodiment of the present invention.
FIG. 6 is a cross-sectional view of the embodiment shown in FIG. 5 along lines 6 - 6 .
FIG. 7 is a top perspective view of the threaded part of the second embodiment without a retaining ring.
FIG. 8 is a bottom perspective view of the drive part of the second embodiment.
FIG. 9 is a side perspective view of a third embodiment of the present invention.
FIG. 10 is a cross-sectional view of the embodiment shown in FIG. 9 along lines 10 - 10 .
FIG. 11 is a top perspective view of the threaded part of the third embodiment without a retaining ring.
FIG. 12 is a bottom perspective view of the drive part of the third embodiment.
FIG. 13 is a side perspective view of a fourth embodiment of the present invention.
FIG. 14 is a cross-sectional view of the embodiment shown in FIG. 13 along lines 14 - 14 .
FIG. 15 is a top perspective view of the threaded part of the fourth embodiment without a retaining ring.
FIG. 16 is a bottom perspective view of the drive part of the fourth embodiment.
FIG. 17 is a side perspective view of a fifth embodiment of the present invention.
FIG. 18 is a cross-sectional view of the embodiment shown in FIG. 17 along lines 18 - 18 .
FIG. 19 is a top perspective view of the threaded part of the fifth embodiment without a retaining ring.
FIG. 20 is a bottom perspective view of the drive part of the fifth embodiment.
FIG. 21 is a side perspective view of a sixth embodiment of the present invention.
FIG. 22 is a cross-sectional view of the embodiment shown in FIG. 21 along lines 22 - 22 .
FIG. 23 is a top perspective view of the threaded part of the sixth embodiment without a retaining ring.
FIG. 24 is a bottom perspective view of the drive part of the sixth embodiment.
DETAILED DESCRIPTION OF THE INVENTION
The weight screws of the present invention are designed to help a golfer achieve discrete weighting goals in golf club heads without sacrificing structural integrity, but do not have to be limited to use with golf clubs, or even sporting equipment, as they can be used with any structure or device that requires or could benefit from adjustable weight technology. The weight screws of the present invention are also designed to be retained on a wrench during adjustment and thus be less susceptible to loss. The weight screws of the present invention may include one or more features of the weight screws disclosed in U.S. patent application Ser. No. 13/410,127, filed on Mar. 1, 2012, the disclosure of which is hereby incorporated by reference in its entirety herein. The weight screws of the present invention may also include any of the features of the embodiments disclosed in U.S. patent application Ser. No. 13/412,395, filed on Mar. 5, 2012, the disclosure of which is hereby incorporated by reference in its entirety herein. In particular, the weight screws of the present invention may include the interrupted thread pattern disclosed in that application.
As shown in the Figures, each screw 10 of the present invention has a first, drive part 20 and a second, threaded part 30 , which combine to create an internal pocket or cavity 40 that houses the retaining ring 50 and prevents it from moving in a vertical direction inside the screw 10 while allowing it to expand horizontally. A preferred embodiment of the present invention is shown in FIGS. 1A through 4B . As shown in these Figures, the drive part 20 has a hexalobular through-bore 21 and a receiving cavity 22 with a plurality of interface surfaces 25 . The threaded part 30 has a threaded region 31 and a head 34 having a projecting portion 32 , which also comprises a plurality of interface surfaces 35 . In order to assemble the screw 10 , the projecting portion 32 mates with the receiving cavity 22 to connect the drive part 20 and the threaded part 30 together, and friction between the interface surfaces 25 , 35 prevents these two parts 20 , 30 from disengaging from one another during use. The interface surfaces 25 of the drive part 20 also bear against the interface surfaces 35 of the threaded part 30 , and transmit torque from the drive part 20 to the threaded part 30 when the screw is being threaded into a receptacle, (such as one of the weight ports shown in U.S. patent application Ser. No. 13/629,391, the disclosure of which is hereby incorporated by reference in its entirety herein) using a wrench or other tool.
The retaining ring 50 , shown in FIGS. 2 and 4A , preferably has a shape similar to the letter C, with an inner opening 52 and a side opening 54 , and is composed of a metal material, but may in alternative embodiments be composed of an elastomeric material. The retaining ring 50 preferably has a diameter that is smaller than the diameter of the cavity 40 . When a torque wrench (not shown) is applied to the screw 10 of the present invention, the tip of the wrench extends through the inner opening 52 of the retaining ring 50 , pushing the two ends 56 , 58 apart and causing the ring's 50 radius to expand in a horizontal direction, press against the wall 42 of the cavity 40 , and press against and grip the tip of the wrench. In this way, the retaining ring 50 causes the screw 10 to become removably affixed to the wrench during removal, and reduces the likelihood that the screw 10 will be lost during adjustment. It is important that the retaining ring 50 be composed of material with sufficient elasticity and structural integrity to ensure expansion and avoid breakage while allowing the retaining ring 50 to return to its original, unexpanded configuration, such as steel or other metal alloys.
The interface surfaces 25 , 35 are shaped to transmit torque from the drive part 20 to the threaded part 30 . As shown in the Figures, interface surfaced 25 , 35 the screw 10 of the present invention may form structures having various shapes or geometries. For example, in the preferred embodiment, the interface surfaces 25 , 35 of the drive and threaded parts 20 , 30 include a circular configuration 26 a , 36 a . In the embodiment shown in FIGS. 5-8 , the interface surfaces 25 , 35 of the drive and threaded parts 20 , 30 include a triangular configuration 26 b , 36 b . In the embodiment shown in FIGS. 9-12 , the interface surfaces 25 , 35 of the drive and threaded parts 20 , 30 include a hexalobular configuration 26 c , 36 c.
In other embodiments, the drive and threaded parts 20 , 30 of the screw may include additional features to ensure that the parts 20 , 30 do not disengage from each other during use. For example, the embodiments shown in FIGS. 13 through 24 include projections or pins 61 , 62 , 63 extending from the receiving cavity 22 of the drive part 20 that mate with holes 71 , 72 , 73 extending into the projecting portion 32 of the threaded part 30 . In the embodiment shown in FIGS. 13-16 , the interface surfaces 25 , 35 of the drive and threaded parts 20 , 30 include a triangular configuration 26 b , 36 b and the pins 61 , 62 , 63 and holes 71 , 72 , 73 described herein. In the embodiment shown in FIGS. 17-20 , the interface surfaces 25 , 35 of the drive and threaded parts 20 , 30 include a different triangular configuration 26 d , 36 d that incorporates the pins 61 , 62 , 63 and holes 71 , 72 , 73 into its structure. In the embodiment shown in FIGS. 21-24 , the interface surfaces 25 , 35 of the drive and threaded parts 20 , 30 include a rounded triangular configuration 26 e , 36 e and the pins 61 , 62 , 63 and holes 71 , 72 , 73 described herein.
Screws 10 with low torque requirements can use simple press fit diameters, such as those included in the embodiments shown in FIGS. 1A through 12 , to transmit the torque, and rely on the friction between the interface surfaces 25 , 35 to resist torque applied to the drive part 20 . For higher torque requirements, the interface surfaces 25 , 35 need to be connected by more than just friction. The embodiments shown in FIGS. 13 through 24 transmit higher torque forces due to the inclusion of pins 61 , 62 , 63 and holes 71 , 72 , 73 , so are more suitable for higher torque requirements.
The embodiments shown in FIGS. 1-24 are not intended to be limiting, however, because the screw 10 of the present invention may incorporate a structure of any shape, including those disclosed herein, in its interface surfaces 25 , 35 to increase friction and transmit torque, and may also combine any of the shapes disclosed herein or known to a person skilled in the art with the pins 61 , 62 , 63 and holes 71 , 72 , 73 described herein. In one alternative embodiment, for example, the pins 61 , 62 , 63 may be disposed on the projecting portion 32 while the holes 71 , 72 , 73 may be disposed within the receiving cavity 22 . The embodiments disclosed herein may also be composed of any number of materials known to a person skilled in the art, and the drive part 20 of the screws 10 disclosed herein may have through-bores with any number of shapes other than hexalobular.
Each of the parts of the embodiments disclosed herein may be composed of any material known to a person skilled in the art, including metal alloys such as tungsten alloy, aluminum alloy, steel, titanium alloy, and magnesium alloy, polymeric materials such as plastic and rubber, and composite materials, and may be made by any process known in the art, including, but not limited to, metal injection molding, powder metallurgy, and thixomolding. The materials used to form the screws 10 disclosed herein can be selected based on the type of weighting required. For example, if a golf club head requires a heavy weight, one or more parts of the screw 10 can be composed of a high density material such as tungsten, whereas a golf club head requiring a lightweight weight could incorporate a screw 10 with one or more parts composed of composite, plastic, aluminum alloy, or magnesium alloy. The material of the drive part 20 can be adjusted, while maintaining a consistent volume of the drive part 20 , to adjust the overall weight of the screw 10 of the present invention, and separating the drive part 20 from the threaded part 30 allows for cost savings if only the drive part 20 material needs to change to provide multiple weighting options.
In one particular embodiment, each of the drive part 20 , threaded part 30 , and retaining ring 50 is formed from stainless steel. Weight screws 10 having this material composition and a length of approximately 0.600 inch were hit tested by engaging the screws 10 with weight ports in a golf club head and then hitting golf balls with the golf club head 10,000 times at a speed of 110 mph at various points on the golf club face. The screws 10 did not crack and their length did not change at any point during this test.
In another particular embodiment, the drive part is 20 is formed from a thixomolded magnesium alloy, while the threaded part 30 is formed from a different, metal alloy.
From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.
|
A screw comprising a drive part, a threaded part, and a retaining ring is disclosed herein. Each of the drive part and the threaded part comprises a plurality of interface surfaces that transmit torque from the drive part to the threaded part and prevent the parts from disengaging from one another during use. Each plurality of interface surfaces forms one or more geometric shapes that create additional friction between the drive and threaded parts, and may further include mating pins and holes to prevent the parts from detaching from one another. The retaining ring, which removably connects the screw to a wrench during assembly of the screw with a receptacle, is disposed within a cavity formed when the drive part is assembled with the threaded part.
| 5
|
CROSS REFERENCE
This is a continuation-in-part of Ser. No. 08/520,710 filed Aug. 29, 1995.
DETAILED DESCRIPTION
The present invention pertains to a class of compounds which inhibit the action of phosphodiesterases, particularly PDE III and PDE IV, and the formation of tumor necrosis factor α, or TNFα, and the nuclear factor κB, or NFκB. These compounds can be diagrammatically represented by the formula: ##STR1## in which: one of R 1 and R 2 is R 3 --X-- and the other is hydrogen, nitro, cyano, trifluoromethyl, carbo(lower)alkoxy, acetyl, carbamoyl, acetoxy, carboxy, hydroxy, amino, lower alkyl, lower alkoxy, halo, or R 3 --X--;
R 3 is monocycloalkyl, bicycloalkyl, or benzocycloalkyl of up to 18 carbon atoms;
X is a carbon-carbon bond, --CH 2 --, or --O--;
R 5 is: (i) o-phenylene, unsubstituted or substituted with 1 to 3 substituents each selected independently from nitro, cyano, halo, trifluoromethyl, carbo(lower)alkoxy, acetyl, or carbamoyl, unsubstituted or substituted with lower alkyl, acetoxy, carboxy, hydroxy, amino, lower alkylamino, lower acylamino, or lower alkoxy; (ii) the vicinally divalent residue of pyridine, pyrrolidine, imidazole, naphthalene, or thiophene, wherein the divalent bonds are on vicinal ring carbon atoms; (iii) a vicinally divalent cycloalkyl or cycloalkenyl of 4-10 carbon atoms, unsubstituted or substituted with 1 to 3 substituents each selected independently from the group consisting of nitro, cyano, halo, trifluoromethyl, carbo(lower)alkoxy, acetyl, carbamoyl, acetoxy, carboxy, hydroxy, amino, lower alkylamino, lower alkyl, lower alkoxy, or phenyl; (iv) vinylene di-substituted with lower alkyl; or (v) ethylene, unsubstituted or monosubstituted or disubstituted with lower alkyl;
R 6 is --CO--, --CH 2 --, or --CH 2 CO--;
Y is --COZ, --C.tbd.N, --OR 8 , lower alkyl, or aryl;
Z is --NH 2 , --OH, --NHR, --R 9 , or --OR 9 ;
R 8 is hydrogen or lower alkyl;
R 9 is lower alkyl or benzyl; and,
n has a value of 0, 1, 2, or 3.
The term alkyl as used herein denotes a univalent saturated branched or straight hydrocarbon chain. Unless otherwise stated, such chains can contain from 1 to 18 carbon atoms. Representative of such alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neo-pentyl, tert-pentyl, hexyl, isohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, and the like. When qualified by "lower", the alkyl group will contain from 1 to 6 carbon atoms. The same carbon content applies to the parent term "alkane" and to derivative terms such as "alkoxy".
The term cycloalkyl as used herein denotes a univalent saturated cyclic hydrocarbon chain. Unless otherwise stated, such chains can contain up to 18 carbon atoms. Monocycloalkyl refers to groups having a single ring. Polycycloalkyl denotes hydrocarbon groups having two or more ring systems having two or more ring atoms in common. Benzocycloalkyl denotes a monocyclic or polycyclic group fused to a benzo ring.
Representative of monocycloalkyl groups are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl, cyclotridecyl, cyclotetradecyl, cyclopentadecyl, cyclohexadecyl, cycloheptadecyl, and cyclooctadecyl. Representative of polycycloalkyl groups are bicyclo 2.2.1!heptyl, bicyclo 3.2.1!octyl, and bicyclo 2.2.2!octyl. Benzocycloalkyl is typified by tetrahydronaphthyl, indanyl, and benzocycloheptanyl.
This invention also relates to a method of reducing the level of cytokines and their precursors in mammals and to compositions useful therein.
TNFα is a cytokine which is released primarily by mononuclear phagocytes in response to immunostimulators. When administered to animals or humans, TNFα can cause inflammation, fever, cardiovascular effects, hemorrhage, coagulation, and acute phase responses similar to those seen during acute infections and shock states.
NFκB is a pleiotropic transcriptional activator (Lenardo, et al., Cell 1989, 58, 227-29) which has been implicated in a variety of disease and inflammatory states. NFκB is thought to regulate cytokine levels including, but not limited to, TNFα and to be an activator of HIV transcription (Dbaibo et al., J. Biol. Chem. 1993, 17762-66; Dub et al., Proc. Natl. Acad. Sci. 1989, 86, 5974-78; Bachelerie et al., Nature 1991, 350, 709-12; Boswas et al., J. Acquired Immune Deficiency Syndrome 1993, 6, 778-786; Suzuki et al., Biochem. and Biophys. Res. Comm. 1993, 193, 277-83; Suzuki et al., Biochem. and Biophys. Res. Comm. 1992, 189, 1709-15; Suzuki et al., Biochem. Mol. Bio. Int. 1993, 31(4), 693-700; Shakhov et al., 1990, 171, 35-47; and Staal et al., Proc. Natl. Acad. Sci. USA 1990, 87, 9943-47. Thus inhibition of NFκB binding can regulate transcription of cytokine gene(s) and through this modulation and other mechanisms is useful in the inhibition of a multitude of disease states. TNFα and NFκB levels are influenced by a reciprocal feedback loop.
Many cellular functions which contribute to inflammatory conditions and diseases including asthma, inflammation, and other conditions are mediated by levels of adenosine 3',5'-cyclic monophosphate (cAMP). See, e.g., Lowe and Cheng, Drugs of the Future, 17(9), 799-807, 1992. It has been shown that the elevation of cAMP in inflammatory leukocytes inhibits their activation and the subsequent release of inflammatory mediators. Increased levels of cAMP also leads to the relaxation of airway smooth muscle. The primary cellular mechanism for the inactivation of cAMP is the breakdown of cAMP by a family of isoenzymes referred to as cyclic nucleotide phosphodiesterases (PDE), of which seven are known. It is recognized, for example, that the inhibition of PDE type IV is particularly effective in both the inhibition of inflammatory mediator release and the relaxation of airway smooth muscle. Thus, compounds which inhibit PDE IV specifically inhibit inflammation and relax airway smooth muscle, with a minimum of unwanted side effects such as cardiovascular or anti-platelet effects. It is now known that inhibition of TNFα production is a consequence of inhibition of PDE IV. Excessive or unregulated TNFα production has been implicated in a number of disease conditions. These include endotoxemia and/or toxic shock syndrome {Tracey et al., Nature 330, 662-664 (1987) and Hinshaw et al., Circ. Shock 30, 279-292 (1990)}; cachexia {Dezube et al., Lancet, 335 (8690), 662 (1990)}; and Adult Respiratory Distress Syndrome where TNFα concentration in excess of 12,000 pg/milliliters have been detected in pulmonary aspirates from ARDS patients (Millar et al., Lancet 2 (8665), 712-714 (1989)). Systemic infusion of recombinant TNFα also resulted in changes typically seen in ARDS {Ferrai-Baliviera et al., Arch. Surg. 124(12), 1400-1405 (1989)}.
TNFα also appears to be involved in bone resorption diseases, including arthritis where it has been determined that when activated, leukocytes will produce a bone-resorbing activity, and data suggest that TNFα contributes to this activity {Bertolini et al., Nature 319, 516-518 (1986) and Johnson et al., Endocrinology 124(3), 1424-1427 (1989)}. It has been determined that TNFα stimulates bone resorption and inhibits bone formation in vitro and in vivo through stimulation of osteoclast formation and activation combined with inhibition of osteoblast function. Although TNFα may be involved in many bone resorption diseases, including arthritis, the most compelling link with disease is the association between production of TNFα by tumor or host tissues and malignancy associated hypercalcemia {Calci. Tissue Int. (US) 46 (Suppl.), S3-10 (1990)}. In Graft versus Host Disease, increased serum TNFα levels have been associated with major complications following acute allogenic bone marrow transplants {Holler et al., Blood, 75(4), 1011-1016 (1990)}.
Cerebral malaria is a lethal hyperacute neurological syndrome associated with high blood levels of TNFα and the most severe complication occurring in malaria patients. Levels of serum TNFα correlated directly with the severity of the disease and the prognosis in patients with acute malaria attacks {Grau et al., N. EngI. J. Med. 320 (24), 1586-1591 (1989)}.
TNFα also appears to play a role in the area of chronic pulmonary inflammatory diseases. The deposition of silica particles leads to silicosis, a disease of progressive respiratory failure caused by a fibrotic reaction. Antibodies to TNFα completely blocked the silica-induced lung fibrosis in mice {Pignet et al., Nature, 344:245-247 (1990)}. High levels of TNFα production (in the serum and in isolated macrophages) have been demonstrated in animal models of silica and asbestos induced fibrosis (Bissonnette et al., Inflammation 13(3), 329-339 (1989)). Alveolar macrophages from pulmonary sarcoidosis patients also have been found to release spontaneously massive quantities of TNFα, as compared with macrophages from normal donors {Baughman et al., J. Lab. Clin. Med. 115 (1), 36-42 (1990)}.
TNFα is also implicated in the inflammatory response which follows reperfusion (reperfusion injury) and is a major cause of tissue damage after loss of blood flow {Vedder et al., PNAS 87, 2643-2646 (1990)}. TNFα also alters the properties of endothelial cells and has various pro-coagulant activities, such as producing an increase in tissue factor pro-coagulant activity and suppression of the anticoagulant protein C pathway as well as down-regulating the expression of thrombomodulin {Sherry et al., J. Cell Biol. 107, 1269-1277 (1988)}. TNFα has pro-inflammatory activities which together with its early production (during the initial stage of an inflammatory event) make it a likely mediator of tissue injury in several important disorders including but not limited to, myocardial infarction, stroke and circulatory shock. Of specific importance may be TNFα-induced expression of adhesion molecules, such as intercellular adhesion molecule (ICAM) or endothelial leukocyte adhesion molecule (ELAM) on endothelial cells {Munro et al., Am. J. Path. 135 (1), 121-132 (1989)}.
Moreover, it is now known that TNFα is a potent activator of retrovirus replication including activation of HIV-1 {Duh et al., Proc. Nat. Acad. Sci. 86, 5974-5978 (1989); Poll et al., Proc. Nat. Acad. Sci. 87, 782-785 (1990); Monto et al., Blood 79, 2670 (1990); Clouse et al., J. Immunol. 142, 431-438 (1989); Poll et al., AIDS Res. Hum. Retrovirus, 191-197 (1992)}. AIDS results from the infection of T lymphocytes with Human Immunodeficiency Virus (HIV). At least three types or strains of HIV have been identified, i.e., HIV-1, HIV-2 and HIV-3. As a consequence of HIV infection, T-cell mediated immunity is impaired and infected individuals manifest severe opportunistic infections and/or unusual neoplasms. HIV entry into the T lymphocyte requires T lymphocyte activation. Other viruses, such as HIV-1 and HIV-2, infect T lymphocytes after T cell activation and such virus protein expression and/or replication is mediated or maintained by such T cell activation. Once an activated T lymphocyte is infected with HIV, the T lymphocyte must continue to be maintained in an activated state to permit HIV gene expression and/or HIV replication. Cytokines, specifically TNFα, are implicated in activated T-cell mediated HIV protein expression and/or virus replication in maintaining T lymphocyte activation. Therefore, interference with cytokine activity such as by prevention or inhibition of cytokine production, notably TNFα, in a HIV-infected individual aids in limiting the maintenance of T lymphocyte activation caused by HIV infection.
Monocytes, macrophages, and related cells, such as kupffer and glial cells, have also been implicated in maintenance of the HIV infection. These cells, like T cells, are targets for viral replication and the level of viral replication is dependent upon the activation state of the cells {Rosenberg et al., The Immunopathogenesis of HIV Infection, Advances in Immunology, 57 (1989)}. Cytokines, such as TNFα, have been shown to activate HIV replication in monocytes and/or macrophages {Poli et al., Proc. Natl. Acad. Sci., 87, 782-784 (1990)}, therefore, prevention or inhibition of cytokine production or activity aids in limiting HIV progression as stated above for T cells. Additional studies have identified TNFα as a common factor in the activation of HIV in vitro and has provided a clear mechanism of action via a nuclear regulatory protein found in the cytoplasm of cells (Osborn, et al., PNAS 86, 2336-2340). This evidence suggests that a reduction of TNFα synthesis may have an antiviral effect in HIV infections, by reducing the transcription and thus virus production.
AIDS viral replication of latent HIV in T cell and macrophage lines can be induced by TNFα {Folks et al., PNAS 86, 2365-2368 (1989)}. A molecular mechanism for the virus inducing activity is suggested by TNFα's ability to activate a gene regulatory protein (NFκB) found in the cytoplasm of cells, which promotes HIV replication through binding to a viral regulatory gene sequence (LTR) {Osborn et al., PNAS 86, 2336-2340 (1989)}. TNFα in AIDS associated cachexia is suggested by elevated serum TNFα and high levels of spontaneous TNFα production in peripheral blood monocytes from patients {Wright et al., J. Immunol. 141 (1) , 99-104 (1988)}.
TNFα has been implicated in other viral infections, such as the cytomegalia virus (CMV), influenza virus, adenovirus, and the herpes family of viruses for similar reasons as those noted.
It is recognized that suppression of the effects of TNFα can be beneficial in a Variety of conditions and in the past, steroids such as dexamethasone and prednisolone as well as polyclonal and monoclonal antibodies {Beutler et al., Science 234, 470-474 (1985); WO 92/11383} have been employed for this purpose. Conditions in which inhibition of TNFα or NFκB is desirable include septic shock, sepsis, endotoxic shock, hemodynamic shock and sepsis syndrome, post ischemic reperfusion injury, malaria, mycobacterial infection, meningitis, psoriasis, congestive heart failure, fibrotic disease, cachexia, graft rejection, cancer, autoimmune disease, opportunistic infections in AIDS, rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis and other arthritic conditions, Crohn's disease, ulcerative colitis, multiple sclerosis, systemic lupus erythrematosis, ENL in leprosy, radiation damage, and hyperoxic alveolar injury. The compounds can be used, under the supervision of qualified professionals, to inhibit the undesirable effects of TNFα, NFκB, or phosphodiesterase. The compounds can be administered orally, rectally, or parenterally, alone or in combination with other therapeutic agents including antibiotics, steroids, etc., to a mammal in need of treatment. Oral dosage forms include tablets, capsules, dragees, and similar shaped, compressed pharmaceutical forms. Isotonic saline solutions containing 20-100 milligrams/milliliter can be used for parenteral administration which includes intramuscular, intrathecal, intravenous and intra-arterial routes of administration. Rectal administration can be effected through the use of suppositories formulated from conventional carriers such as cocoa butter.
Dosage regimens must be titrated to the particular indication, the age, weight, and general physical condition of the patient, and the response desired but generally doses will be from about 1 to about 1000 milligrams/day as needed in single or multiple daily administration. In general, an initial treatment regimen can be copied from that known to be effective in interfering with TNFα activity for other TNFα mediated disease states by the compounds of the present invention. Treated individuals will be regularly checked for T cell numbers and T4/T8 ratios and/or measures of viremia such as levels of reverse transcriptase or viral proteins, and/or for progression of cytokine-mediated disease associated problems such as cachexia or muscle degeneration. If no effect is observed following the normal treatment regimen, then the amount of cytokine activity interfering agent administered is increased, e.g., by fifty percent a week.
The compounds of the present invention can also be used topically in the treatment or prophylaxis of topical disease states mediated or exacerbated by excessive TNFα production, such as viral infections, for example those caused by the herpes viruses or vital conjunctivitis, psoriasis, other skin disorders and diseases, etc.
The compounds can also be used in the veterinary treatment of mammals other than humans in need of prevention or inhibition of TNFα production. TNFα mediated diseases for treatment, therapeutically or prophylactically, in animals include disease states such as those noted above, but in particular viral infections. Examples include feline immunodeficiency virus, equine infectious anaemia virus, caprine arthritis virus, visna virus, and maedi virus, as well as other lentiviruses.
The compounds of this invention possess at least one center of chirality, that to which the depicted phenyl group is attached, and thus will exist as optical isomers. Both the racemates of these isomers and the individual isomers themselves, as well as diastereoisomers when there are two or more chiral centers, are within the scope of the present invention. The racemates can be used as such or can be separated into their individual isomers mechanically as by chromatography using a chiral absorbent. Alternatively, the individual isomers can be prepared in chiral form or separated chemically from a mixture by forming salts with a chiral acid, such as the individual enantiomers of 10-camphorsulfonic acid, camphoric acid, alpha-bromocamphoric acid, methoxyacetic acid, tartaric acid, diacetyltartaric acid, malic acid, pyrrolidone-5-carboxylic acid, and the like, and then freeing one or both of the resolved bases, optionally repeating the process, so as to obtain either or both isomers substantially free of the other; i.e., in a form having an optical purity of >95%.
Inhibition of production of TNFα by these compounds can be conveniently assayed using methods known in the art. For example, TNFα Inhibition Assays can be determined by a variety of known methods.
PBMC from normal donors is obtained by Ficoll-Hypaque density centrifugation. Cells are cultured in RPMI supplemented with 10% AB+ serum, 2 mM L-glutamine, 100 U/mL penicillin and 100 mg/mL streptomycin. The active compound is dissolved in DMSO (Sigma Chemical) and further dilutions are done in supplemented RPMI. The final DMSO concentration in the presence or absence of drug in the PBMC suspensions is 0.25 wt %. Test candidates are assayed at half-log dilutions starting at 50 mg/mL, being added to PBMC (10 6 cells/mL) in 96 wells plates one hour before the addition of LPS. PBMC (10 6 cells/mL) in the presence or absence of the compound is stimulated by treatment with 1 mg/mL of LPS from Salmonella minnesota R595 (List Biological Labs, Campbell, Calif.). Cells are then incubated at 37° C. for 18-20 hours. The supernatants then are harvested and assayed immediately for TNFα levels or frozen at -70° C. (for not more than 4 days) until assayed. The concentration of TNFα in the supernatant is determined by human TNFα ELISA kits (ENDOGEN, Boston, Mass.) according to the manufacturer's directions.
Particularly preferred are compounds in which R 5 is o-unsubstituted or substituted phenylene, R 1 is lower alkoxy, R 3 is monocycloalkyl of up to 10 carbon atoms, R 6 is --CO-- or --CH 2 --, Y is lower alkyl, --COZ or --C.tbd.N, Z is --NH 2 , --OH, or --O(lower alkyl), and n has a value of 0 or 1.
The compounds of the present invention can be prepared using methods known per se. For example, a cyclic acid anhydride or a lactone is allowed to react with the appropriate disubstituted phenyl compound: ##STR2## in which R 1 , R 2 , R 5 , R 6 , Y, and n are as defined above. The reaction can be effected simply by heating, analogously to the methods described in U.K. Patent Specification No. 1,036,694, the disclosure of which is incorporated herein by reference. Optionally acetic acid, with or without sodium acetate, can be added.
In place of the acid anhydride or lactone, one can utilize an N-carbethoxy derivative of the formula: ##STR3##
In a further embodiment, compounds in which R 6 is --CH 2 -- can be formed through condensation of a dialdehyde with a disubstituted phenyl compound in the presence of refluxing acetic acid utilizing the method of Griggs et al., J. Chem. Soc., Chem. Comm., 1985, 1183-1184, the disclosure of which is incorporated herein by reference.
The disubstituted phenyl starting materials can be obtained through condensation of an appropriately substituted aldehyde and malonic acid, with intermediate formation of the phenyl amidine and subsequent decarboxylation.
The disubstituted aldehydes can be prepared utilizing classical methods for ether formation; e.g., reaction with the appropriate bromide in the presence of potassium carbonate. Numerous cycloalkyloxy benzaldehydes and procedures for preparing them are described in the literature. See, e.g., Ashton et al., J. Med. Chem., 1994, 37, 1696-1703; Saccomano et al., J. Med. Chem., 1994, 34, 291-298; and Cheng et al., Org. and Med. Chem. Lett., 1995, 5(17), 1969-1972, the disclosures of which are incorporated herein by reference.
Representative starting materials include 3-cyclopentyloxy-4-methoxybenzaldehyde, 3-cyclopentyloxy-4-ethoxybenzaldehyde, 3-cyclohexyloxy-4-methoxybenzaldehyde, 3-(exo-bicyclo 2.2.1!hept-2-yloxy)-4-methoxybenzaldehyde, 3-(endo-bicyclo 2.2.1!hept-2-yl-oxy)-4-methoxybenzaldehyde, 3-(bicyclo 2.2.2!oct-2-yloxy)-4-methoxybenzaldehyde, 3-(bicyclo 3.2.1!oct-2-yloxy)-4-methoxybenzaldehyde, 3-indan-2-yloxy-4-methoxybenzaldehyde, and 3-(endo-benzo-bicyclo 2.2.1!hept-2-yloxy)-4-methoxybenzaldehyde.
The following examples will serve to further typify the nature of this invention but should not be construed as a limitation in the scope thereof, which scope is defined solely by the appended claims.
EXAMPLE 1
3-Amino-3-(3-cyclopentyloxy-4-methoxyphenyl)propionic Acid
A stirred suspension of 3-cyclopentyloxy-4-methoxybenzaldehyde (10.0 g, 45.4 mmol) and ammonium acetate (7.00 g, 90.8 mmol) in ethanol (95%, 30 mL) under nitrogen was heated to 45°-50° C. and malonic acid (4.72 g, 45.4 mmol) was added. The solution was heated at reflux for 24 hours. The mixture was allowed to cool to room temperature and was then filtered. The solid which is collected was washed with ethanol, air dried and then dried in vacuo (60° C., <1 mm) to afford 7.36 g (58%) of the product: mp 225°-226° C.; 1 H NMR (D 2 O/NaOH/TSP) δ 7.05-6.88 (m, 3H), 4.91-4.78 (m, 1H), 4.21-4.14 (m, 1H) 3.79 (s, 3H), 2.59-2.46 (m, 2H), 2.05-1.48 (m, 8H). Trace impurity peaks were present at 6.39 and 7.34 ppm. 13 C NMR (D 2 O/NaOD/TSP) δ 182.9, 150.7, 149.1, 140.6, 121.6, 116.0, 114.9, 83.9, 58.5, 55.3, 49.8, 34.9, 26.3.
Similarly prepared from 3-cyclopentyloxy-4-methoxybenzaldehyde, 3-cyclopentyloxy-4-ethoxybenzaldehyde, and 3-cyclohexyloxy-4-methoxybenzaldehyde are 3-amino-3-(3-cyclopentyloxy-4-methoxyphenyl)propionic acid, 3-amino-3-(3-cyclopentyloxy-4-ethoxyphenyl)propionic acid, and 3-amino-3-(3-cyclohexyloxy-4-methoxyphenyl)propionic acid, respectively.
EXAMPLE 2
3-Phthalimido-3-(3-cyclopentyloxy-4-methoxyphenyl)propionic Acid
To a stirred mixture of 3-amino-3-(3-cyclopentyloxy-4-methoxyphenyl)propionic acid (2.34 g, 8.40 mmol) and sodium carbonate (0.96 g, 9.05 mmol) in a mixture of water (20 mL) and acetonitrile (20 mL) under nitrogen was added N-carbethoxyphthalimide (1.9 g, 8.4 mmol). After 3 hours, the acetonitrile was removed in vacuo. The pH of the solution was adjusted to 1 with aqueous hydrogen chloride (4 N). Ether (5 mL) was added and the mixture stirred for 1 hour. The resulting slurry was filtered and the solid washed with water, air dried and then dried in vacuo (60° C., <1 mm) to afford 2.92 g (85%) of the product as a white solid: mp 159°-162° C.; 1 H NMR (DMSO- 6 ) δ 12.40 (br s, 1H), 7.96-7.80 (m, 4H), 7.02 (s, 1H), 6.90 (s, 2H), 5.71-5.52 (m, 1H), 4.81-4.65 (m, 1H), 3.70 (s, 3H), 3.59-3.16 (m, 2H), 2.00-1.44 (m, 8H); 13 C NMR (DMSO-d 6 ) δ 171.7, 167.6, 149.1, 146.8, 134.6, 131.2, 131.1, 123.1, 119.4, 113.9, 112.1, 79.5, 55.5, 50.1, 36.1, 32.1, 32.1, 23.5; Anal. Calcd for C 23 H 23 NO 6 . Theoretical: C, 67.47; H, 5.66; N, 3.42. Found: C, 67.34; H, 5.59; N, 3.14.
Similarly prepared are 3-phthalimido-3-(3-cyclopentyloxy-4-methoxyphenyl)propionic acid, 3-phthalimido-3-(3-cyclopentyloxy-4-ethoxyphenyl)propionic acid, 3-phthalimido-3-(3-cyclohexyloxy-4-methoxyphenyl)propionic acid, 3-phthalimido-3-{3-(bicyclo- 3.2.1!oct-2-yloxy)-4-methoxyphenyl}propionic acid, 3-phthalimido-3-{3-indan-2-yloxy-4-methoxyphenyl{propionic acid, and 3-phthalimido-3-{3-(endo-benzobicyclo 2.2.1!hept-2-yloxy)-4-methoxyphenyl}propionic acid.
EXAMPLE 3
3-Phthalimido-3-(3-cyclopentyloxy-4-methoxyphenyl)propionamide
A mixture of 3-phthalimido-3-(3-cyclopentyloxy-4-methoxyphenyl)propionic acid (2.05 g, 5.00 mmol), 1,1'-carbonyldiimidazole (0.91 g, 5.5 mmol) and 4-dimethylaminopyridine (trace) in tetrahydrofuran (20 mL) was stirred for 1.5 hours under nitrogen at approximately 25° C. To the solution was added ammonium hydroxide (1.07 mL, 16.0 mmol, 28-30%) and stirring was continued for 1.5 hours. A small amount of solid forms during this time. The mixture was concentrated to half its volume and a white solid precipitated. The mixture was filtered, washed with a small amount of tetrahydrofuran, air dried, and dried in vacuo (60° C.,<1 mm) to afford 1.27 g of the product. The product was further purified by flash column chromatography (silica gel, 5% methanol/methylene chloride) and the resulting white solid was dried in vacuo (60° C., <1 mm) to afford 1 g (49%) of the product: mp 165°-166° C.; 1 H NMR (CDCl 3 ) δ 7.85-7.61 (m, 4H), 7.16-7.04 (m, 2H), 6.85-6.75 (m, 1H), 5.80 (dd, J=5.8, 10.4 Hz, 1H), 5.66 (br s, 1H), 5.54 (br s, 1H), 4.82-4.70 (m, 1H), 3.80 (s, 3H), 3.71 (dd, J=10.4, 15 Hz, 1H), 3.06 (dd, J=5.8, 15 Hz, 1H), 2.06-1.51 (m, 8H); 13 C NMR (CDCl 3 ) δ 171.8, 168.3, 149.8, 147.7, 133.9, 131.8, 131.3, 123.3, 119.9, 114.6, 111.8, 80.4, 56.0, 51.6, 37.9, 32.7, 24.1; Anal. Calcd for C 23 H 24 N 2 O 5 . Theoretical: C, 67.63; H, 5.92; N, 6.86. Found: C, 67.25; H, 5.76; N, 6.68.
Similarly prepared are 3-phthalimido-3-(3-cyclopentyloxy-4-methoxyphenyl)propionamide, 3-phthalimido-3-(3-cyclopentyloxy-4-ethoxyphenyl)propionamide, 3-phthalimido-3-(3-cyclohexyloxy-4-methoxyphenyl)propionamide, 3-phthalimido-3-(3-(endo-bicyclo- 2.2.1!hept-2-yloxy)-4-methoxyphenyl}propionamide, 3-phthalimido-3-{3-(bicyclo 2.2.2!oct-2-yloxy)-4-methoxyphenyl}propionamide, 3-phthalimido-3-{3-(bicyclo 3.2.1!oct-2-yloxy)-4-methoxyphenyl}-propionamide, 3-phthalimido-3-{3-indan-2-yloxy-4-methoxyphenyl-{propionamide, and 3-phthalimido-3-{3-(endo-benzobicyclo 2.2.1!-hept-2-yloxy)-4-methoxyphenyl}propionamide.
EXAMPLE 4
Methyl 3-amino-3-(3-cyclopentyloxy-4-methoxyphenyl)propionate
To a cooled (ice bath temperature) and stirred mixture of 3-amino-3-(3-cyclopentyloxy-4-methoxyphenyl)propionic acid (3.00 g, 10.7 mmol) in methanol (20 mL) under nitrogen was added thionyl chloride (1.8 mL, 2.3 mmol) dropwise via syringe. The resulting solution was stirred at 0° C. for 1 hour, the ice bath was removed and stirring was continued at RT for 1 hour and a white solid precipitated. The methanol was removed and the solid was slurried in hexane. The mixture was filtered and the white solid was washed with hexane, air dried and then dried in vacuo (60° C., <1 mm) to afford 2.69 g (76%) of the product as the hydrochloride salt: mp 183°-184.5° C.; 1 NMR (DMSO-d 6 ) δ 8.76 (br s, 3H), 7.25 (s, 1H), 7.06-6.89 (m, 2H), 4.85-4.75 (m, 1H), 4.58-4.44 (m, 1H), 3.74 (s, 3H), 3.55 (s, 3H), 3.31-2.86 (m, 2H), 2.06-1.44 (m, 8H); 13 C NMR (DMSO-d 6 ) δ 169.1, 149.3, 146.5, 128.4, 119.5, 113.5, 111.4, 79.0, 55.0, 51.2, 50.3, 38.2, 31.7, 31.6, 23.0; Anal. Calcd for C 16 H 24 ClNO 4 . Theoretical.: C, 58.27; H, 7.33; N, 4.25. Found: C, 58.44; H, 7.34; N, 4.13.
Similarly prepared are methyl 3-amino-3-(3-cyclopentyloxy-4-methoxyphenyl)propionate, methyl 3-amino-3-(3-cyclopentyloxy-4-ethoxyphenyl)propionate, and methyl 3-amino-3-(3-cyclohexyloxy-4-methoxyphenyl)propionate, all as the hydrochloride.
EXAMPLE 5
Methyl 3-phthalimido-3-(3cyclopentyloxy-4-methoxyphenyl)propionate
To a stirred solution of methyl 3-amino-3-(3-cyclopentyloxy-4-methoxyphenyl)propionate hydrochloride (0.50 g, 1.52 mmol) and sodium carbonate (0.16 g, 1.52 mmol) in a mixture of water (5 mL) and acetonitrile (5 mL) under nitrogen was added N-carbethoxyphthalimide (0.34 g, 1.52 mmol). The solution was stirred for 3 hours at RT. The acetonitrile was removed in vacuo which afforded a two layer mixture which was extracted with methylene chloride (3×15 mL). The combined organic extracts were dried over magnesium sulfate, filtered and then Concentrated in vacuo to afford 0.77 g of the crude product as an oil. The crude product was purified by flash column chromatography (silica gel, 35/65, ethyl acetate/hexane) the resulting glassy solid was dried in vacuo to afford 0.48 g (75%) of the product as a white solid: mp 76°-78° C.; 1 H NMR (CDCl 3 ) δ 7.86-7.60 (m, 4H), 7.19-7.00 (m, 2H), 6.88-6.72 (m, 1H), 5.84-5.67 (m, 1H), 4.85-4.70 (m, 1H), 3.80 (s, 3H), 3.80-3.69 (m, 1H), 3.63 (s, 3H), 3.34-3.15 (m, 1H), 2.10-1.48 (m, 8H); 13 C NMR (CDCl 3 ) δ 171.0, 168.0, 149.8, 147.6, 133.9, 131.8, 130.9, 123.2, 120.1, 114.6, 111.7, 80.4, 55.9, 51.8, 50.7, 35.9, 32.7, 24.0; Anal. Calcd for C 24 H 25 NO 6 . Theoretical: C, 68.03; H, 5.95; N, 3.31. Found: C, 67.77; H, 5.97; N, 3.20.
Similarly prepared are methyl 3-phthalimido-3-(3-cyclopentyloxy-4-methoxyphenyl)propionate, methyl 3-phthalimido-3-(3-cyclopentyloxy-4-ethoxyphenyl)propionate, and methyl 3-phthalimido-3-(3-cyclohexyloxy-4-methoxyphenyl)propionate.
EXAMPLE 6
3-Amino-3-(3-{exo-bicyclo 2.2.1!hept-2-yloxy}-4-methoxyphenyl)propionic Acid
A stirred suspension of 3-(exo-bicyclo 2.2.1!hept-2-yloxy)-4-methoxybenzaldehyde (6.00 g, 24.4 mmol) and ammonium acetate (3.76 g, 48.8 mmol) in ethanol (95%, 20 mL) under nitrogen was heated to 45°-50° C. and malonic acid (2.53 g, 24.4 mmol) was added. The solution was refluxed for 24 hours, allowed to cool to room temperature, and filtered. The solid was washed with ethanol, air dried, and dried in vacuo (60° C., <1 mm) to afford 3.17 g (43%) of the product: mp 225°-226° C.; 1 H NMR (D 2 O/NaOD/TSP) δ 7.09-6.90 (m, 3H), 4.41-4.28 (m, 1H), 4.27-4.15 (m, 1H), 3.82 (s, 3H), 2.64-2.48 (m, 2H) 2.44 (s, 1H), 2.31 (s, 1H), 1.92-1.76 (m, 1H), 1.69-1.38 (m, 4H), 1.30-1.05 (m, 3H).
Similarly prepared from 3-(endo-bicyclo 2.2.1!hept-2-yloxy)-4-methoxybenzaldehyde, 3-(bicyclo 2.2.2!oct-2-yloxy)-4-methoxybenzaldehyde, 3-(bicyclo 3.2.1!oct-2-yloxy)-4-methoxybenzaldehyde, 3-indan-2-yloxy-4-methoxybenzaldehyde, and 3-(endo-benzobicyclo 2.2.1!hept-2-yloxy)-4-methoxybenzaldehyde are 3-amino-3-(3-(endo-bicyclo 2.2.1!hept-2-yloxy)-4-methoxyphenyl}propionic acid, 3-amino-3-{3-(bicyclo 2.2.2!oct-2-yloxy)-4-methoxyphenyl}propionic acid, 3-amino-3-{3-(bicyclo 3.2.1!oct-2-yloxy)-4-methoxyphenyl}propionic acid, 3-amino-3-{3-indan-2-yloxy-4-methoxyphenyl{propionic acid, and 3-amino-3-{3-(endo-benzobicyclo 2.2.1!hept-2-yloxy)-4-methoxyphenyl}propionic acid, respectively.
EXAMPLE 7
Methyl 3-Amino-3-(3-{exo-bicyclo 2.2.1!hept-2-yloxy}-4-methoxyphenyl)propionate Hydrochloride
To an ice bath cooled stirred suspension of 3-amino-3-(3-{exo-bicyclo 2.2.1!hept-2-yloxy}-4-methoxyphenyl)propionic acid (2.00 g, 6.55 mmol) in methanol (15 mL) under nitrogen was added thionyl chloride (1.56 mL, 13.1 mmol) dropwise via syringe. The resulting solution was stirred at 0° C. for 30 minutes, the ice bath was removed and stirring was continued at room temperature for 2.5 hours. The methanol was removed and the solid slurried in hexane (15 mL). The mixture was filtered and the white solid washed with hexane, air dried and then dried in vacuo (60° C., <1 mm) to afford 1.97 g (85%) of the product: mp 197.5°-201.5° C.; 1 H NMR (DMSO-d 6 ) δ 7.50 (br s, 3H), 7.18 (s, 1H), 7.07-6.88 (m, 2H), 4.56-4.42 (m, 1H), 4.30-4.19 (m, 1H), 3.74 (s, 3H), 3.54 (s, 3H), 3.41-2.85 (m, 3H), 2.37 (s, 1H), 2.27 (s, 1H), 1.92-1.75 (m, 1H), 1.64-1.03 (m, 6H); 13 C NMR (DMSO-d 6 ) δ 169.4, 149.6, 146.4, 128.8, 120.0, 119.9, 113.8, 111.8, 80.1, 79.9, 55.5, 51.6, 50.7, 40.5, 39.2, 38.6, 34.8, 27.8, 23.7, 23.6.
Similarly prepared are methyl 3-amino-3-(3-(endo-bicyclo- 2.2.1!hept-2-yloxy)-4-methoxyphenyl}propionate, methyl 3-amino-3-(3-(bicyclo 2.2.2!oct-2-yloxy)-4-methoxyphenyl}propionate, methyl 3-amino-3-(3-(bicyclo 3.2.1!oct-2-yloxy)-4-methoxyphenyl)-propionate, methyl 3-amino-3-(3-indan-2-yloxy-4-methoxyphenyl-{propionate, and methyl 3-amino-3-{3-(endo-benzobicyclo 2.2.1!hept-2-yloxy)-4-methoxyphenyl)propionate.
EXAMPLE 8
By following the procedure of Example 3 but substituting 3-phthalimido-3-(3-{exo-bicyclo 2.2.1!hept-2-yloxy}-4-methoxyphenyl)propionic acid, there is obtained 3-phthalimido-3-(3-{exo-bicyclo 2.2.1!hept-2-yloxy}-4-methoxyphenyl)propionamide.
Similarly prepared are 3-phthalimido-3-{3-(endo-bicyclo- 2.2.1!hept-2-yloxy)-4-methoxyphenyl}propionamide, 3-phthalimido-3-{3-(bicyclo 2.2.2!oct-2-yloxy)-4-methoxyphenyl}propionamide, 3-phthalimido-3-{3-(bicyclo 3.2.1!oct-2-yloxy)-4-methoxyphenyl}-propionamide, 3-phthalimido-3-{3-indan-2-yloxy-4-methoxyphenyl-{propionamide, and 3-phthalimido-3-{3-(endo-benzobicyclo 2.2.1!-hept-2-yloxy)-4-methoxyphenyl}propionamide.
EXAMPLE 9
Methyl 3-Phthalimido-3-(3-{exo-bicyclo 2.2.1!hept-2-yloxy}-4-methoxyphenyl)propionate
To a stirred solution of methyl 3-amino-3-(3-{exo-bicyclo- 2.2.1!hept-2-yloxy}-4-methoxyphenyl)propionate hydrochloride (1.00 g, 2.81 mmol) and sodium carbonate (0.3 g, 2.8 mmol) in a mixture of water (10 mL) and acetonitrile (10 mL) under nitrogen was added N-carbethoxyphthalimide (0.64 g, 2.81 mmol). The solution was stirred for 3 hours at room temperature. The acetonitrile was remove in vacuo and the residue extracted with methylene chloride (3×30 ml). The combined organic extracts were dried over magnesium sulfate, filtered and concentrated in vacuo to afford 1.44 g of the product. The product was further purified by flash column chromatography (silica gel, 20%, ethyl acetate/methylene chloride) to afford a white solid which was then dried in vacuo to afford 0.23 g (18%) of product: mp 47°-48° C.; 1 H NMR (CDCl 3 ) δ 7.86-7.61 (m, 4H), 7.14-7.00 (m, 2H), 6.82-6.74 (m, 1H), 5.75 (dd, J=5.9, 10 Hz, 1H), 4.25-4.14 (m, 1H), 3.84-3.69 (m, 1H), 3.79 (s, 3H), 3.63 (s, 3H), 3.23 (dd, J=5.9, 16.5 Hz, 1H), 2.51-2.41 (m, 1H), 2.34-2.24 (m, 1H), 1.86-1.06 (m, 8H); 13 C NMR (CDCl 3 ) δ 171.1, 168.1, 149.7, 147.2, 133.9, 131.8, 130.9, 123.3, 120.1, 120.0, 114.5, 114.4, 111.8, 81.1, 56.0, 51.9, 50.8, 41.1, 41.0, 39.9, 39.8, 35.9, 35.5, 35.3, 28.4, 24.3; HPLC 97%; Anal. Calcd for C 26 H 27 NO 6 . Theoretical: C, 69.47; H, 6.05; N, 3.12. Found: C, 69,22; H, 5.91; N, 2.95.
Similarly prepared are methyl 3-phthalimido-3-{3-(endo-bicyclo 2.2.1!hept-2-yloxy)-4-methoxyphenyl}propionate, methyl 3-phthalimido-3-{3-(bicyclo 2.2.2!oct-2-yloxy)-4-methoxyphenyl}propionate, methyl 3-phthalimido-3-{3-(bicyclo 3.2.1!oct-2-yloxy)-4-methoxyphenyl}propionate, methyl 3-phthalimido-3-{3-indan-2-yloxy-4-methoxyphenyl{propionate, and methyl 3-phthalimido-3-{3-(endo-benzobicyclo 2.2.1!hept-2-yloxy)-4-methoxyphenyl}propionate.
Example 10
1-(3-Cyclopentoxy-4-methoxyphenyl)propylamine
To an ice bath cooled stirred solution of 1,1,1,3,3,3-hexamethyldisilazane (2.5M, 4.1 mL, 19.5 mmol) in tetrahydrofuran (5 mL) under nitrogen, was added a hexane solution of butyl lithium (7.2 mL, 18 mmol) via syringe. The ice bath was removed and the solution was stirred for 30 minutes at room temperature. This solution then was added dropwise to an ice bath cooled solution of 3-cyclopentoxy-4-methoxybenzaldehyde (3.3 g, 15 mmol) in tetrahydrofuran (5 mL) and the mixture stirred for 20 minutes. An ethereal solution of ethylmagnesium bromide (3M, 10 mL, 30 mmol) then was added dropwise. The reaction solution was allowed to reach room temperature and then was stirred at room temperature. The reaction progress was monitored by HPLC (Waters Nova-Pak/EC 18 column, 3.9×150 mm, 4 micron, 1 mL/min, 240 nm, 35/65, CH 3 CN/0.1% H 3 PO 4 (aq)) and after 3 hours no starting material remained. The reaction mixture was slowly poured into a saturated solution of ammonium chloride (100 mL). The resulting mixture was extracted with methylene chloride (3×20 mL) and the combined extracts were dried over magnesium sulfate and concentrated in vacuo to yield 5.6 g of product which was further purified by flash column chromatography (silica gel, 250/10/1, methylene chloride/methanol/ammonium hydroxide) to afford 2.5 g (67%) of the product as an oil: 1H NMR (CDCl 3 ) δ 6.91-6.77 (m, 3H), 4.85-4.74 (m, 1H), 3.83 (s, 3H), 3.74 (t, J=6.8 Hz, 1H), 2.02-1.15 (m, 12H), 0.86 (t, J=7.4 Hz, 3H); 13 C NMR (CDCl 3 ) δ 148.8, 147.5, 138.8, 118.4, 113.3, 111.8, 80.3, 57.4, 56.0, 32.7, 32.4, 10.9.
EXAMPLE 11
3-Phthalimido-3-(3-cyclopentoxy-4-methoxyphenyl)propane
To a stirred solution of 1-(3-cyclopentoxy-4-methoxyphenyl)propylamine (1 g, 4 mmol) and sodium carbonate (0.42 g, 4.0 mmol) in a mixture of water (5 mL) and acetonitrile (5 mL) under nitrogen was added N-carbethoxyphthalimide (0.9 g, 4.0 mmol). The solution was stirred for 2.5 hours at room temperature. The acetonitrile was remove in vacuo which resulted in the precipitation of a white solid. The mixture was filtered and the solid was washed with water, air dried and then dried in vacuo to afford 1.25 g (83%) of product: mp 100.0°-102.5° C.; 1H NMR (CDCl 3 ) δ 7.87-7.61 (m, 4H), 7.21-7.01 (m, 2H), 6.85-6.75 (m, 1H), 5.15 (dd, J=7, 9.3 Hz, 1H), 4.86-4.74 (m, 1H), 3.81 (s, 3H), 2.66-2.20 (m, 2H), 2.08-1.47 (m, 8H), 0.95 (t, J=7.3 Hz, 3H); 13 C NMR (CDCl 3 ) δ 168.4, 149.4, 147.5, 133.8, 132.2, 131.9, 123.1, 120.5, 115.0, 111.5, 80.3, 55.6, 55.9, 32.7, 24.4, 11.6; HPLC (Waters Nova-Pak/EC 18 column, 3.9×150 mm, 4 micron, 1 mL/min, 240 nm, 60/40, CH 3 CN/0.1% H 3 PO 4 (aq)) 12 min, 99%; Anal. Calcd for C 23 H 25 NO 4 . Theoretical: C, 72.80; H, 6.64; N, 3.69. Found: C, 72.72; H, 6.69; N, 3.65.
EXAMPLE 12
1-(3-Indanyloxy-4-methoxyphenyl)propylamine
To an ice bath cooled stirred solution of 1,1,1,3,3,3-hexamethyldisilazane (2.7 mL, 13 mmol) in tetrahydrofuran (5 mL) under nitrogen, was added a hexane solution of butyl lithium (2.5M, 4.8 mL, 12 mmol) via syringe. The ice bath was removed and the solution was stirred for 25 minutes at room temperature. This solution then was added dropwise to an ice bath cooled solution of 3-indanyloxy-4-methoxybenzaldehyde (2.68 g, 10.0 mmol) in tetrahydrofuran (4 mL) and the mixture was stirred for one hour. An ethereal solution of ethylmagnesium bromide (3M, 6.7 mL, 20 mmol) then was added dropwise via syringe. The reaction mixture was heated at reflux and was monitored by HPLC (Waters Nova-Pak/EC 18 column, 3.9×150 mm, 4 micron, 1 mL/min, 240 nm, 40/60, CH 3 CN/0.1% H 3 PO 4 (aq)). After 48 hours the reaction had reached completion and was allowed to cool to room temperature. The reaction mixture then was slowly poured into a saturated solution of ammonium chloride (80 mL). The resulting mixture was extracted with methylene chloride (3×15 mL) and the combined extracts were dried over magnesium sulfate and concentrated to afford the product which was further purified by flash column chromatography (silica gel, 250/10/1, methylene chloride/methanol/ammonium hydroxide) to afford 0.27 g (9%) of product as an orange solid.
EXAMPLE 13
1-Phthalimido-1-(3-indanyloxy-4-methoxyphenyl)propane
To a stirred solution of 1-(3-indanyloxy-4-methoxyphenyl)propylamine (0.25 g, 0.84 mmol) and sodium carbonate (0.09 g, 0.84 mmol) in a mixture of water (2 mL) and acetonitrile (2 mL) under nitrogen was added N-carbethoxyphthalimide (0.19 g, 0.84 mmol). The solution was stirred for 4 hours at room temperature. The acetonitrile was removed in vacuo and the resulting mixture was extracted with methylene chloride (2×10 mL), dried over magnesium sulfate and concentrated in vacuo to afford 0.35 g of the product which was further purified by flash column chromatography (silica gel, 25/75, ethyl acetate/hexane) to afford 0.19 g (48%) of the product as a solid: mp 62° C.; 1 H NMR (CDCl 3 ) δ 7.86-7.63 (m, 4H), 7.29-7.04 (m, 6H), 6.87-6.78 (m, 1H), 5.30-5.14 (m, 2H), 3.77 (s, 3H), 3.52-3.14 (m, 4H), 2.66-2.21 (m, 2H), 0.97 (t, J=7.3 Hz, 3H); 13 C NMR (CDCl 3 ) δ 168.4, 149.6, 147.1, 140.7, 140.6, 133.8, 132.2, 131.8, 126.5, 124.6, 123.1, 121.2, 115.3, 111.7, 79.0, 56.5, 55.9, 39.6, 39.6, 24.4, 11.6; HPLC (Waters Nova-Pak/EC 18 column, 3.9×150 mm, 4 micron, 1 mL/min, 240 nm, 60/40, CH 3 CN/0.1% H 3 PO 4 (aq)) 12 min, 98%; Anal. Calcd for C 27 H 25 NO 4 . Theoretical: C, 75.86; H, 5.89; N, 3.28. Found: C, 75.58; H, 5.90; N, 3.20.
EXAMPLE 14
1-(1-Oxoisoindoline)-1-(3-cyclopentoxy-4-methoxyphenyl)propane
A stirred solution of phthalic dicarboxaldehyde (0.4 g, 3 mmol) and 1-(3-cyclopentoxy-4-methoxyphenyl)propylamine (0.75 g, 3.0 mmol) in glacial acetic acid (9 mL) under nitrogen was heated at reflux for 5 minutes. The stirred reaction then was allowed to cool to room temperature and concentrated in vacuo to afford the product which was further purified by flash column chromatography on silica gel, first with 40/60 ethyl acetate/hexane and then with 15/85, ethyl acetate/methylene chloride) to afford 0.48 g (44%) of the product as a yellow oil: 1H NMR (CDCl 3 ) δ 7.97-7.76 (m, 1H), 7.61-7.31 (m, 3H), 7.06-6.74 (m, 3H), 5.54-5.39 (m, 1H), 4.87-4.66 (m, 1H), 4.28 (d, J=17 Hz, 1H), 4.00 (d, J=17 Hz, 1H), 3.82 (s, 3H), 2.25-1.45 (m, 10H), 0.99 (t, J=7.3 Hz, 3H); 13 C NMR (CDCl 3 ) δ 168.3, 149.4, 147.5, 141.1, 132.7, 132.2, 130.9, 127.7, 123.5, 122.6, 119.3, 114.9, 111.6, 80.3, 55.9, 55.8, 45.3, 32.6, 32.5, 24.2, 23.8, 10.9; HPLC (Waters Nova-Pak/EC 18 column, 3.9×150 mm, 4 micron, 1 mL/min, 240 nm, 50/50, CH 3 CN/0.1% H 3 PO 4 ) 8 min, 100%.
EXAMPLE 15
3-(1-Oxoisoindoline)-3-(3-cyclopentyloxy-4-methoxyphenyl)-propionic Acid
A stirred solution of phthalic dicarboxaldehyde (0.67 g, 5.00 mmol) and 3-amino-3-(3-cyclopentyloxy-4-methoxyphenyl)propanoic acid (1.40 g, 5.01 mmol) in 20 mL of glacial acetic acid under nitrogen was heated to reflux for 5 minutes. The stirred reaction then was allowed to cool to room temperature overnight. The resulting yellow brown solution was concentrated in vacuo and the solid which formed slurried in ethyl acetate (25 mL). The slurry was filtered and the solid dried in vacuo to afford 1.52 g (77%) of the product as a white powder: mp 161°-163° C.; 1 H NMR (dmso-D 6 /TMS) δ 12.33 (br s, 1 H, COOH), 7.75-7.4 (m , 4 H, Ar), 7.05-6.8 (m, 3 H, Ar), 5.66 (app. t, J=7.9 Hz, 1 H), 4.75 (m, 1 H), 4.51 (d, J=17.7 Hz, 1 H), 4.11 (d, J=17.7 Hz, 1 H), 3.71 (s, 3 H), 3.12 (m, 2 H), 1.95-1.45 (m, 8 H); 13 C NMR (dmso-D 6 /TMS) δ 171.8, 149.1, 146.8, 141.6, 132.1, 131.5, 131.3, 127.8, 123.4, 122.8, 119.2, 114.0, 112.2, 79.4, 55.5, 51.0, 46.3, 36.7, 32.1, 32.0, 23.4. Anal. Calcd for C 23 H 25 NO 5 . Theory: C, 69.86; H, 6.37; N, 3.54. Found: C, 69.59; H, 6.35; N, 3.44.
EXAMPLE 16
Methyl 3-(1-oxoisoindoline)-3-(3-cyclopentyloxy-4-methoxyphenyl)propionate.
To a stirred suspension of 3-(1-oxoisoindoline)-3-(3-cyclopentyloxy-4-methoxyphenyl)propionic acid (0.758 g, 1.92 mmol) in 10 mL of methanol cooled in an ice bath and under nitrogen was added 0.3 mL of thionyl chloride. After stirring for 15 minutes, the mixture was allowed to warm to room temperature and stirred overnight. The solvent was evaporated and the residue dissolved in methylene chloride and washed with saturated aqueous sodium bicarbonate solution and brine. The organic layer was dried over sodium sulfate and concentrated in vacuo. The residue was purified by flash chromatography (silica gel, 1/9 ethyl acetate/methylene chloride) to afford 0.6 g of the product which was stirred in hexane. The slurry was filtered to afford 0.32 g of the product as a white solid: mp 94.5°-95.5° C.; 1 H NMR (CDCl 3 /TMS) δ 7.85 (d , J=6.7 Hz, 1 H, Ar), 7.55-7.3 (m, 3 H, Ar), 7.0-6.75 (m, 3 H), 5,92 (dd, J=9.1, 7.0 Hz, 1 H), 4.74 (m, 1 H), 4.37 (d, J=16.7 Hz, 1 H), 4.07 (d, J=16.7 Hz, 1 H), 3.82 (s, 3 H), 3.64 (s, 3 H), 3.23 (dd, J=9.1, 15.0 Hz, 1 H), 3.10 (dd, J=9.1, 15.0 Hz, 1 H), 2.05-1.45 (m, 8 H); 13 C NMR (CDCl 3 /TMS) δ 170.9, 149.8, 147.8, 141.3, 132.6, 131.3, 131.0, 127.9, 123.8, 122.7, 119.0, 114.6, 111.8, 80.5, 56.0, 52.0, 51.7, 46.6, 40.0, 32.7, 32.7, 24.0. Anal. Calcd for C 24 H 27 NO 5 . Theory: C, 70.40; H, 6.65; N, 3.42. Found: C, 70.07; H, 6.63; N, 3.34.
EXAMPLE 17
Tablets, each containing 50 milligrams of active ingredient, can be prepared in the following manner:
______________________________________Constituents (for 1000 tablets)______________________________________active ingredient 50.0 gramslactose 50.7 gramswheat starch 7.5 gramspolyethylene glycol 6000 5.0 gramstalc 5.0 gramsmagnesium stearate 1.8 gramsdemineralized water q.s.______________________________________
The solid ingredients are first forced through a sieve of 0.6 mm mesh width. The active ingredient, the lactose, the talc, the magnesium stearate and half of the starch then are mixed. The other half of the starch is suspended in 40 milliliters of water and this suspension is added to a boiling solution of the polyethylene glycol in 100 milliliters of water. The resulting paste is added to the pulverulent substances and the mixture is granulated, if necessary with the addition of water. The granulate is dried overnight at 35° C., forced through a sieve of 1.2 mm mesh width and compressed to form tablets of approximately 6 mm diameter which are concave on both sides.
EXAMPLE 18
Tablets, each containing 100 milligrams of active ingredient, can be prepared in the following manner:
______________________________________Constituents (for 1000 tablets)______________________________________active ingredient 100.0 gramslactose 100.0 gramswheat starch 47.0 gramsmagnesium stearate 3.0 grams______________________________________
All the solid ingredients are first forced through a sieve of 0.6 mm mesh width. The active ingredient, the lactose, the magnesium stearate and half of the starch then are mixed. The other half of the starch is suspended in 40 milliliters of water and this suspension is added to 100 milliliters of boiling water. The resulting paste is added to the pulverulent substances and the mixture is granulated, if necessary with the addition of water. The granulate is dried overnight at 35° C., forced through a sieve of 1.2 mm mesh width and compressed to form tablets of approximately 6 mm diameter which are concave on both sides.
EXAMPLE 19
Tablets for chewing, each containing 75 milligrams of active ingredient, can be prepared in the following manner:
______________________________________Composition (for 1000 tablets)______________________________________active ingredient 75.0 gramsmannitol 230.0 gramslactose 150.0 gramstalc 21.0 gramsglycine 12.5 gramsstearic acid 10.0 gramssaccharin 1.5 grams5% gelatin solution q.s.______________________________________
All the solid ingredients are first forced through a sieve of 0.25 mm mesh width. The mannitol and the lactose are mixed, granulated with the addition of gelatin solution, forced through a sieve of 2 mm mesh width, dried at 50° C. and again forced through a sieve of 1.7 mm mesh width. The active ingredient, the glycine and the saccharin are carefully mixed, the mannitol, the lactose granulate, the stearic acid and the talc are added and the whole is mixed thoroughly and compressed to form tablets of approximately 10 mm diameter which are concave on both sides and have a breaking groove on the upper side.
EXAMPLE 20
Tablets, each containing 10 milligrams of active ingredient, can be prepared in the following manner:
______________________________________Composition (for 1000 tablets)______________________________________active ingredient 10.0 gramslactose 328.5 gramscorn starch 17.5 gramspolyethylene glycol 6000 5.0 gramstalc 25.0 gramsmagnesium stearate 4.0 gramsdemineralized water q.s.______________________________________
The solid ingredients are first forced through a sieve of 0.6 mm mesh width. Then the active ingredient, lactose, talc, magnesium stearate and half of the starch are intimately mixed. The other half of the starch is suspended in 65 milliliters of water and this suspension is added to a boiling solution of the polyethylene glycol in 260 milliliters of water. The resulting paste is added to the pulverulent substances, and the whole is mixed and granulated, if necessary with the addition of water. The granulate is dried overnight at 35° C., forced through a sieve of 1.2 mm mesh width and compressed to form tablets of approximately 10 mm diameter which are concave on both sides and have a breaking notch on the upper side.
EXAMPLE 21
Gelatin dry-filled capsules, each containing 100 milligrams of active ingredient, can be prepared in the following manner:
______________________________________Composition (for 1000 capsules)______________________________________active ingredient 100.0 gramsmicrocrystalline cellulose 30.0 gramssodium lauryl sulphate 2.0 gramsmagnesium stearate 8.0 grams______________________________________
The sodium lauryl sulphate is sieved into the active ingredient through a sieve of 0.2 mm mesh width and the two components are intimately mixed for 10 minutes. The microcrystalline cellulose is then added through a sieve of 0.9 mm mesh width and the whole is again intimately mixed for 10 minutes. Finally, the magnesium stearate is added through a sieve of 0.8 mm width and, after mixing for a further 3 minutes, the mixture is introduced in portions of 140 milligrams each into size 0 (elongated) gelatin dry-fill capsules.
EXAMPLE 22
A 0.2% injection or infusion solution can be prepared, for example, in the following manner:
______________________________________active ingredient 5.0 gramssodium chloride 22.5 gramsphosphate buffer pH 7.4 300.0 gramsdemineralized water to 2500.0 mL______________________________________
The active ingredient is dissolved in 1000 milliliters of water and filtered through a microfilter or slurried in 1000 mL of H 2 O. The buffer solution is added and the whole is made up to 2500 milliliters with water. To prepare dosage unit forms, portions of 1.0 or 2.5 milliliters each are introduced into glass ampoules (each containing respectively 2.0 or 5.0 milligrams of active ingredient).
|
Novel amides are inhibitors of TNFα and phosphodiesterase and can be used to combat cachexia, endotoxic shock, retrovirus replication, asthma, and inflammatory conditions. A typical embodiment is 3-phthalimido-3-(3-cyclopentyloxy-4-methoxyphenyl)propionamide.
| 2
|
FEDERALLY SPONSORED RESEARCH
Not Applicable
SEQUENCE LISTING OR PROGRAM
Not Applicable
BACKGROUND
1. Field of Invention
This is a motor vehicle safety device that warns of vehicles in the driver's blind-spot.
2. Prior Art
Drivers of motor vehicles should be aware of other nearby vehicles, particularly when they are changing lanes on a multilane highway. Rearview mirrors, required safety equipment for automobiles, address the need drivers have to monitor the traffic situation behind them. Some drivers have difficulty making adequate use of their rearview mirrors. One problem arises when another vehicles is close to them in an adjacent lane, slightly behind the driver's vehicle, so the nearby vehicle is not visible in the inside rearview mirror and is not visible in the driver's peripheral vision when the driver is looking straight ahead. This is the so-called blind-spot problem. Another related problem is that some drivers do not check their rearview mirror every few seconds to continually update their knowledge about the traffic situation behind them. These problems become worse when distractions, such as cell phone conversations or disruptive children, compete for the driver's attention. These problems also worsen when long trips fatigue drivers.
Traffic safety experts and people working in the automobile industry recognize the blind-spot problem. Systems have been developed, in addition to rearview mirrors, to address this problem. Typical prior-art systems, represented by U.S. Pat. No. 6,388,565, have sensors, signal processing, and a driver interface. These three elements in the prior art systems have problems what retard widespread use. The sensors are typically technically advanced and sophisticated devices such as radar or ultrasound. These technically sophisticated sensors are generally expensive, which is a problem for widespread deployment. Another disadvantage of technically sophisticated sensors is that they generally require technically sophisticated signal processing. For a system that uses, for example, radar, the signal processing must either determine when a vehicle is in the blind-spot, or it must present data that will allow the driver to determine a blind-spot presence. Making a safety system responsible for interpreting the sensor data for the driver is risky. False warning mistakes annoy the driver, and mistakes of missed vehicles are dangerous. Different cases that need to be considered make interpretation difficult. For example, the system will detect cars in the blind spot when stuck in traffic jams or when in a city; but warnings sent to the driver in these situations might be unwelcome. The interface to the driver is typically a warning such as a flashing light, a sound, or a vibration that the driver feels. The interface must provide a positive warning to the driver without annoying the driver. An interface that is helpful without being annoying is difficult.
The present invention uses tire noise of nearby vehicles to give blind-spot warnings. U.S. Pat. No. 3,158,835 has many elements of the present invention. However, anyone implementing the system taught by U.S. Pat. No. 3,158,835 would find that the sounds presented by the system that originate from the host vehicle would limit usefulness of the system. U.S. Pat. No. 3,158,835 does not adequately teach how to discriminate between the sounds from the host vehicle and the useful sounds of nearby vehicles. Perhaps because sources of constant noise are annoying, there are no known direct descendants of U.S. Pat. No. 3,158,835, and it has not been developed into an available product. The philosophy of quieting host noise to enhance the usefulness of environmental noise for safety is shown in U.S. Pat. No. 6,325,173 that shows the use of wind screens in front of bicyclists' ears so they can better hear overtaking cars. The car safety invention described here differs from the bicycle windscreen patent because it teaches how to make useful sounds available to someone operating a vehicle inside a sound-blocking enclosure.
Another prior art, U.S. Pat. No. 4,943,798 and similar patents, uses many of the same elements of this invention but for the purpose of monitoring the mechanical health of remote tires and wheels on tractor trailer trucks.
Another prior art, U.S. Pat. No. 5,278,553, uses microphones outside a car. This patent teaches how to warn a deaf driver, or a driver listening to a loud sound system, when an emergency vehicle's siren is sounding nearby. The purpose of this patent, the nature of the signal processing, and the interface to the driver are all different from the present invention.
The near absence of prior art blind-spot warning systems that use tire noise is striking. This absence is due in part to basic goals and assumptions that guide the automotive industry. Modern automobiles are quiet inside. They are designed to block road or tire noise, and wind noise. Most people judge quiet cars to be good, and quieter cars to be better. The ability to keep passenger compartments quiet has been aided by the widespread use of automobile air conditioners so windows often remain closed in all types of weather, particularly at highway speeds. The automobile industry considers road noise, in particular, to be a nuisance with no redeeming value. The use of road noise as a useful and interesting sensual input is a paradigm shift for the automotive industry. This helps explain why the use of tire noise to alert drivers to vehicles in their blind-spot has not been pursued by the automotive industry, but instead was demonstrated by a bicycle rider who was able to build a demonstration in his basement from inexpensive components.
Objects and Advantages
This invention alerts a driver to vehicles in his blind spots by allowing the driver to hear nearby vehicles. Another object of this invention is to help drivers to be more alert by making driving a more sensually rich experience. Another object of this invention is to not annoy drivers with useless noise. A further object of this invention is to make driving more interesting.
This invention can be implemented with inexpensive hardware. The sensors are electret microphones in one demonstration implementation. The signal processing is relatively simple because this system does not make any decisions concerning the need to warn the driver about blind-spot intrusions. The data is presented to the driver without interpretation. The driver provides the interpretation function. Also, the signal processing need use only audio frequency signals, which are easy to manipulate.
The interface is straightforward. The driver hears sounds that seem to come from nearby vehicles. The sounds actually come from inexpensive loudspeakers. These sounds resemble the sounds that would be heard from nearby vehicles if the noise-blocking passenger compartment were not in the way. A driver using this system does not perceive any increase in wind noise or tire noise coming from his vehicle. The sounds from this safety system are of much higher quality, that is, free from extraneous noise, than what a driver would hear if she opened her windows at highway speeds. Drivers find the sounds made by this system, which seem to come from the highway environment, easy to interpret, useful, and interesting.
This system does not noticeably add objectionable noise to the passenger compartment. By using directionally selective microphones and electronic signal processing that exploits the directional properties of the microphones, the system essentially rejects noise coming from the host vehicle. The only sounds that the driver notices coming from the safety system are useful sounds from nearby vehicles.
The data interpretation function is done by the driver. This is an important point that makes this system superior to the prior art represented by U.S. Pat. No. 6,388,565. People are extremely good at interpreting sounds from activities happening close to them, when the sounds are not blocked by an enclosure. This ability to interpret sounds is built into people's neurological system. It operates naturally and it operates unconsciously, that is, without conscious effort. New sounds coming from behind have a high priority ability to focus attention. To say this another way, new sounds coming from behind are automatically considered to be very important by primitive parts of the human brain. This ability does not need to be learned. The ability to accurately and automatically interpret sounds that correspond to environmental situations is shared by many animals. This remarkable ability is the result of millions of years of evolution. The vehicle safety system described here makes use of this ability.
Another advantage of this invention is that drivers find that using this device is interesting. Drivers appreciate the additional sensual inputs provided, not only for the safety benefit, but because the sounds make driving more fun. Being able to hear clearly what is happening nearby is a welcome, natural ability enjoyed by people who have normal hearing, and sadly missed by people who are hearing impaired. No one, for example, would consider wearing ear plugs while making love, except perhaps if they had been married for thirty years. People enjoy the sounds from this system because they mitigate the aural sensory deprivation caused by modern, sound-insulated cars.
One benefit of the sounds provided by this system being interesting is that drivers do not need to be encouraged or coerced to use the system. They enjoy using the system.
Another benefit of this invention is that because driving is more interesting when drivers can hear what is happening around them, drivers stay more alert and better focused on their driving tasks on long trips.
The sounds produced by this safety system need not interfere with traditional in-car activities. The driver has no difficulty conversing with passengers or listening to the car radio while using this system. Passengers are barely aware of the system's presence.
Microphones have advantages as sensors. They are inexpensive, the required signal processing for use in blind-spot warnings is simple, and microphones are adequate to do an excellent job for automobiles. However, there are applications for which passive microphones have limitations and for which cost is not a major concern. One example is a system to warn a pilot of nearby aircraft. The advantages of an interface that mimics natural sound could be combined with radar sensors, or any sensors that can detect objects and estimate their location.
DRAWING FIGURES
FIG. 1 shows an automobile with this sound-based safety system.
FIG. 2 shows two loudspeakers mounted on the driver's seat.
FIG. 3 shows directional microphones incorporated into an automobile's taillight assemblies.
FIG. 4 shows another embodiment of directional microphones suitable for mounting on the rear of an automobile.
FIG. 5 is a block diagram of the preferred embodiment of this sound-based safety system.
FIG. 6 shows a sound-based safety system joined with other automobile components to address the problem of children being injured by vehicles backing out of parking spots.
FIG. 7 is a block diagram of a level-dependent filter.
FIG. 8 is a block diagram of the controls for the level-dependent filter.
FIG. 9 is a block diagram of a compressor.
FIG. 10 is a block diagram of method to compensate for varying pavement surfaces.
FIG. 11 is a block diagram of a safety system that has a human interface that is based on sound.
FIG. 12 is a block diagram of a sound-based safety system adapted for people with asymmetric hearing
FIG. 13 is a circuit diagram of the level-dependent filter shown in FIG. 7 .
FIG. 14 is a circuit diagram of controls that mate with the circuit diagram of FIG. 13 .
FIG. 15 is a circuit diagram of the compressor shown in FIG. 9 .
DETAILED DESCRIPTION
FIGS. 1 and 2 —Preferred Embodiment
FIG. 1 shows the rear of an automobile, the host vehicle for a sound-based safety system, with two directionally discriminating microphones 20 mounted on the back, electronic signal processing 22 inside the car, two loudspeakers 24 mounted on the driver's seat beside the headrest, interconnecting wiring 26 between the microphones 20 and signal processing 22 , and interconnection wiring 28 between the signal processing 22 and loudspeakers 24 . The microphones 20 on the back of the host vehicle are directional so that they respond strongly to sounds coming from vehicles near the host vehicle while responding only weakly to sounds coming from the host vehicle. The primary source of sound that this system uses is tire noise. The host vehicle produces tire noise and this is usually not a useful sound. By using directional microphones, the system provides a much clearer aural picture of the driving environment.
FIG. 2 shows the loudspeakers 24 mounted on the driver's seat so they are close to the driver's ears. This loudspeaker placement allows the system to easily and clearly convey location information to the driver. This loudspeaker placement has the further advantage that passengers in the vehicle are not generally aware of the sounds from the safety system. FIG. 2 also shows controls 30 mounted on the driver's seat headrest. This placement avoids changing the design of the dashboard or other control-intensive location in the vehicle. Further, this location of controls 30 near the safety system loudspeakers 24 is logical in that it is close to the mechanical embodiment of the system's interface to the driver. The controls 30 will be simple, perhaps a volume control and a single switch that will select either a normal mode of operation or a mode for people with asymmetrical left-right hearing. Once these two controls have been set, they will rarely need to be changed.
Directionally Discriminating Microphones
The objective of this sound-based safety system is to enable the driver to hear vehicles in his blind spots while not annoying the driver with sounds that originate from his own vehicle. Directionally discriminating microphones play an important role. Directionally discriminating microphones are preferentially sensitive to sounds that come from certain orientations and discriminate against other sounds. The directionally discriminating microphones of this system are aimed at vehicles behind and beside the host vehicle and discriminate against sounds that come from the host vehicle.
The directionally discriminating microphones for this safety system can be implemented in several ways. For demonstrating the principles of this invention without making irreversible modifications to an existing automobile, the microphones have been parabolic reflectors that mount on the car with magnets so the microphones can be placed, repositioned, and removed without modifying the car. These microphones are shown in FIG. 1 . The microphones for the demonstration system were molded on a parabolic surface 15 centimeters in diameter at the outer edge of the mold, and the focal point of the parabola is 3.3 centimeters from the inside-most point of the parabola surface. In each reflector an electret microphones about 10 millimeters in diameter and 7 millimeters in length is mounted with its acoustic openings facing the innermost point of the parabola and about 3.2 cm from the innermost point of the reflector surface. The parabolic reflector and electret microphone are covered with a windscreen made from a fabric that is acoustically nearly transparent but which inhibits wind from blowing directly on the electret microphone. The windscreens reduces noise caused from air passing by the microphones due to the forward motion of the vehicle or due to wind. The fabric wind screens were treated to make them water-repellent, so the microphones operate properly in wet weather. The microphones are aimed so that the axes of the parabolic reflectors, that is the axis of maximum sensitivity to sound, point down about 5 degrees. The axes of the parabolic reflectors point slightly to the sides. The microphone on the right side points to the right by about ten degrees. The microphone on the left points to the left by about ten degrees. The microphones are positioned approximately as shown in FIG. 1 .
The parabolic reflector microphones described above have advantages for developing and demonstrating the system on an existing vehicle, but a better choice is available for a mass-produced product. FIGS. 3 and 4 each show two directional microphones. In FIG. 3 the microphones are incorporated into the taillight assemblies of an automobile. These microphones each have a tapered acoustic waveguide 32 with external opening 34 . The waveguides curve upward inside the vehicle and end at electret microphones 38 . The external openings 34 of the waveguides 32 are covered with screens 36 . These screens prevent insects and other objects from entering the waveguides and they serve as windscreens that reduces noise from air moving past the vehicle as a result of vehicle motion and natural air currents from wind. Tapered acoustic waveguides are well known for their ability to make efficient loudspeakers by improving the acoustic impedance match between the loudspeaker driver and the air in the listening room. This safety invention exploits the directional properties of tapered acoustic waveguides. The external openings 34 of the waveguides 32 have dimensions that are large compared to the wavelengths of some portion of the spectrum of sounds of interest. For sounds that have wavelengths smaller than the dimensions of the openings, the microphones are directional. The same general relationship between size of the microphone, wavelengths of sound, and directionality apply to microphones with parabolic reflectors. By making the openings 34 of the waveguides 32 non-circular, the pattern of the directionality can be made non-circular. The waveguides 32 shown in FIG. 3 are curved so that the electret microphones 38 inside the automobile are protected from environmental hazards such as rain and car washes. That is, the electret microphone elements 38 that may be water-sensitive are protected from water because water will drain downhill, away from the water-sensitive elements. This arrangement mimics the way that the most sensitive parts of the human ear are protected.
FIG. 4 shows that the opening of the acoustic waveguides 32 can be substantially non-symmetric from left to right so that although the axes of the waveguides point nearly straight back, the response of the left microphone to a vehicle close to the host vehicle and on the left side of the host vehicle will be much stronger than the response of the right microphone. In FIG. 4 the two waveguides are mounted side-by-side near the center of the automobile, and their axes of maximum sensitivity both point straight back from the vehicle. Opening region 40 extends further toward the back of the vehicle than opening areas 42 . Because of these asymmetrical openings, the two microphones respond differently to vehicles in the left and right blind spots, thus allowing the position of vehicles in the left and right blind spots to be accurately distinguished by ear.
Block Diagram of the Preferred Embodiment— FIG. 5
FIG. 5 shows a block diagram of one channel of the safety system. The blocks starting with microphone amplifier 44 , including level-dependent filter 46 , level-dependent filter controller 48 , level-dependent filter controls 50 , compressor 52 , volume control 54 , and power amplifier 56 are the signal processing portion of the system. The directional microphone 20 , the level-dependent filter 46 and the level-dependent filter controller 48 are elements that work together to make the system relatively insensitive to noise originating from the host vehicle while making it sensitive to sounds coming from nearby vehicles.
FIG. 5 shows several less-common signal processing functions, which are represented in FIG. 5 by the level-dependent filter 46 and its controller 48 , and the compressor 52 . The level-dependent filter 46 complements the directional microphones 20 that are directional only for the higher portion of the frequency spectrum that represents sounds of interest. If the microphones were directionally selective for the entire spectrum of sounds for which the system responds, they would be quite large compared with the taillights of automobiles. By employing a level-dependent filter, larger microphones are unnecessary.
FIG. 6 , a System Addressing Backing Accidents in Driveways
FIG. 6 shows a system, which includes the sound-based safety system, that reduces the danger of backing over children in driveways. The problem of injuries to children from people backing automobiles out of driveways may be addressed by the following combination of measures: (a) Limit reverse speed initially to a slow speed, perhaps walking speed of 3 miles per hour, by a governor, or to a low acceleration, (b) Automatically mute the car radio/sound system when the vehicle is backing, (c) Automatically increase the gain of the sound-based safety system when the vehicle is backing. These three measures are shown as a system, in block-diagram form, in FIG. 6 . When the vehicle transmission 58 is in reverse, the sound-based safety system 60 has its gain increased, the radio sound system 62 is muted, and the vehicle speed or acceleration is limited by engine control 64 . This allows a child playing behind the vehicle to scream and alert the driver before being overrun.
Level Dependent Filter and Controller
The level-dependent filter 46 has two basic specifications. First, when there are no loud sounds nearby, such as sounds produced by high-speed vehicles near the host vehicle, the level-dependent filter should have no noticeable effect on the signals passing through it. Second, when the host vehicle is traveling at speed and there is another vehicle nearby, the level-dependent filter should make the sounds from the nearby vehicle seem natural. The level-dependent filter in this case counteracts the frequency dependence of the directional microphones without losing the directional advantages of the microphones. One consequence of the first specification is that if the host vehicle is at rest and a person outside the vehicle and not on the axes of the microphones speaks, the driver will hear the person speaking and the sound will seem natural. This ability will help drivers from backing over children in driveways as noted in the system of FIG. 6 .
Having described the objectives of the level-dependent filter, the structure of one embodiment can now be understood.
FIG. 7 shows a block diagram of a level-dependent filter. The notation of this block diagram is familiar to engineers who work with dynamic system designs. The blocks 72 and 74 with “1/s” inside are integrators. The “s” variable is the Laplace transform variable which, roughly speaking, represents frequency. The blocks 76 and 78 with “2*zeta*omega o ” and “omega o 2 ” are gains. The circles 66 , 68 , and 70 are summing junctions. The four blocks 72 , 74 , 76 , and 78 , and two summing junctions 66 and 68 comprise a second order “state-space” filter with a high-pass output from summing junction 66 , a bandpass output from gain block 76 , and a low-pass output from gain block 78 . The “resonant frequency” of the filter is omega o and the damping ratio is zeta. When the variable gain blocks 80 and 82 have gain of 1, the signal output, formed by summing three signals at summing junction 70 , is the same as the input signal on the left of FIG. 7 . When a vehicle is nearby and at speed, the control signals 50 , from the level-dependent filter controller 48 , change the gains of blocks 80 and 82 to make the sounds heard by the driver seem more natural. Without the level-dependent feature of this filter, vehicles would sound unnaturally high in frequency as the directional microphones responded preferentially to the higher frequencies of the vehicles that are near their axis of symmetry.
FIG. 8 shows the level-dependent filter controls in block diagram form. FIG. 8 shows two independent controls 50 provided to the level-dependent filter, called “bandpass filter control” and “high-pass filter control.”. The bandpass filters 84 and 90 respond to signals in some selected band of frequencies. If there is adequate signal in the frequency region accepted by bandpass filter 84 or bandpass filter 90 , the rectifier and low-pass filter 86 or 92 produces a change in a slowly varying, nearly direct-current signal. These near-direct-current signals are further provided with gain, zero, and possibly dead-zone adjustments, by blocks 88 and 94 , to interface appropriately with the level-dependent filter. Because the control signals 50 , provided to the level-dependent filter 46 to change gains, have slowly changing levels, there is no noticeable distortion caused by the level-dependent filters.
FIG. 7 shows the mathematical concept of the level-dependent filter without showing a practical implementation. FIG. 13 is a circuit diagram of an implementation of a level-dependent filter using analog circuits. While the implementation shown here is well suited to testing and demonstrating the concepts of this invention, a shipped product would likely be implemented with digital signal processing.
Circuit Diagrams of Level Dependent Filter and Controller
The circuit diagrams of FIGS. 13 , 14 , and 15 are designed to operate with four AA size alkaline batteries as the power supply. The power supply voltage is designated as “Vc.” The voltage designated as “Vc/2” is half the battery voltage. In FIG. 13 , op amps 134 and 136 form the two integrators of the state space filter. Pot 138 adjusts the resonant frequency of the filter, and it also affects the damping ratio of the filter. Pot 138 adjusts the gain shown in FIG. 7 as “omega o 2 .” This one pot adjusts the resonant frequency of all three paths of the filter, the low-pass, bandpass and high-pass paths. Pot 140 adjusts the damping ratio. Pot 140 with op amp 142 adjusts the gain shown in FIG. 7 as “2*zeta*omega o .” This adjustment changes the damping ratio for all three paths. These adjustments are useful for experimenting, but could be fixed for a shipped product. JFET 144 changes the gain of the bandpass path. JFET 146 changes the gain of the high frequency path. These two JFETs are used as voltage controlled resistors. The use of JFETs for this purpose is well-known and is described in application notes from JFET manufacturers. In order to obtain proper operation of the JFETs, the JFETs must be selected for proper on resistance and gate-source cutoff voltage, and the individual devices must have control voltages that come from circuits that have gain and offset adjustments, and these adjustments must be adjusted for the particular individual JFET that they control. This need for adjustments is of little concern for a demonstration implementation, but for a mass-produced product this would be a serious disadvantage. For this and other reasons, using digital signal processing to implement is attractive. Op amp 148 sums the low-pass, bandpass and high-pass paths. Op amp 150 performs the summing function that in FIG. 7 is done by summing junctions 66 and 68 .
FIG. 14 shows a circuit diagram of an implementation of the level-dependent filter controller that works with the circuit of FIG. 13 . Op amps 154 and 156 with JFET 158 and associated resistors provides a reference voltage that is used repeatedly to adjust the offset of the controls for the JFETs that are used as voltage controlled resistors. This reference voltage is independent of supply voltage and it has a temperature dependence that derives from JFET 158 in such a way that the properties of the system do not change noticeably with temperature. Op amps 160 , 162 , and 164 form the bandpass filter for the filter controller for the level-dependent filter's bandpass gain. The configuration shown allows a relatively high resonant frequency and a very low damping ratio to be implemented with op amps that have a modest gain-bandwidth. While this configuration was useful for experimental purposes, it is not necessary, and a simpler bandpass filter would be adequate. FIGS. 7 and 8 show two independent controls 50 . The control for the level-dependent band pass filter path is the more important in the sense that it uses high frequency signals to control much lower frequency signal gains in the level-dependent filter, and thus implements the objective of obtaining natural-sounding output from directional microphones that have limited directional bandwidth. The control for the gain of the high-pass path of the level-dependent filter makes the sound output of the system more interesting by giving the sounds produced an additional sense of depth. This high-pass section of the level-dependent filter changes the color of the sound of a nearby vehicle as it comes closer to the host car. The control for the high-pass path uses the bandpass filter of the level-dependent filter as the filter that selects the spectral region whose signal energy changes the gain of the level-dependent filter's high pass path. That is, signal 152 of FIG. 13 is also signal 152 of FIG. 14 . For the bandpass controller, potentiometer 166 adjusts the resonant frequency of the bandpass filter, potentiometer 168 adjusts the gain of the bandpass controller, potentiometer 170 adjusts the dead zone, potentiometer 172 adjusts the control offset, and potentiometer 174 adjusts the high limit. For the high-pass controller, potentiometer 176 adjusts the gain, and potentiometer 178 adjusts the control offset.
Compressor
FIG. 9 is a block diagram of a compressor. The purpose of the compressor is to keep loud sounds from being uncomfortably loud. The problem addressed by the compressor is that occasionally there are unusually loud sounds from traffic, such as sounds made by a truck or a horn. The compressor turns down the volume on sounds that would otherwise be unpleasantly loud. The signal strength of the output of the compressor gets monitored by a rectifier and low-pass filter, 98 . Based on the output signal strength, the gain at the input to the compressor gets adjusted by a variable gain element 96 , with louder signals causing the gain to be reduced.
FIG. 15 is a circuit diagram of a compressor. This circuit shows two channels corresponding to the preferred embodiment of a left and a right channel. The JFETs 180 and 182 are used as voltage controlled resistors as is done in the level-dependent filter. The rectifier for the right channel, formed by op amp 184 and associated components, gets inputs from both the left and right channels through resistors 186 and 188 . Using inputs from both channels as inputs to the gain control for each channel keeps the level of attenuation from the compressors in the left and right channel approximately balanced. For the left channel, potentiometer 190 adjusts offset and potentiometer 192 adjusts gain.
Signal Levels
Returning to FIG. 5 , the microphone amplifier 44 , volume control 54 , and power amplifier 56 use routine technology. Amplifying microphone signals to drive a loudspeaker is well-known art. However, parts of this safety system, the level-dependent filter 46 and the level-dependent filter controller 48 , are nonlinear and so signal levels are important. The gain of the microphone amplifier 44 for the demonstration system described here has a voltage gain of about 6 for use with an electret microphone with gain of −42 dB where 0 dB is 1 volt per pascal, mounted in a 15 centimeter diameter parabolic reflector. This gain is appropriate for dry pavement. For wet pavement, a gain of about 3 is appropriate because tires make more noise on wet pavement. These gains work well with the circuits shown in FIGS. 13 and 14 .
FIG. 10 , Automatically Monitoring Highway Acoustic Properties
FIG. 10 is a block diagram of a sound-based safety system such as is shown in FIG. 5 but with the addition of a microphone 100 whose purpose is to monitor the condition of the pavement and the speed of the host vehicle that together determine the tire noise characteristic of that combination of pavement and speed. The signal of the pavement-monitoring microphone 100 is used to change the signal processing properties of the sound-based safety system. The signal processing block 102 monitors the signal from the pavement monitoring microphone 100 to produce a nearly-dc control signal indicative of signal strength from the pavement monitoring microphone 100 . This control signal from signal processing block 102 changes the characteristics of signal processing block 104 . One use of the pavement-monitoring microphone is to change the gain of the microphone amplifiers 44 that are part of signal processing block 104 . This gain, as has been noted, is profitably changed based on pavement conditions. Wet pavement makes more noise than dry pavement, and some pavements are noticeably more quiet than others. Making automatic gain adjustments would make this sound-based safety system sound more natural and more useful to the user. Also, the pavement-monitoring microphone would automatically increase gains at low speed to improve safety when backing up.
Additional Embodiment—A System with Generalized Sensors
FIG. 11 shows another embodiment of this invention. This embodiment makes use of the previously described sound-based interface to the user, but with sensors 106 of any sort. In this embodiment, the user hears sounds that seem natural and that represent important nearby objects. However, the sensors are not necessarily microphones, and the sounds are synthesized, If radar sensors were used, for example, the signals sent to the loudspeakers 24 would be generated based not on directly sensed sounds from outside the system, but would be based on estimated locations of nearby items of interest. The sensors 106 , orientation estimator 108 and distance estimator 110 would detect and estimate the location of items of interest. Then the system would generate signals that when played by the loudspeakers would represent the sensed objects in the object's estimated position. The objects could be assigned a base sound that could resemble tire noise, aircraft noise, ship propeller noise, or other sounds. A base sound generator 112 creates a signal representing this base sound. The volume of the sound is used to represent estimated distance. The volume is adjusted by the volume control 114 based on the estimated distance from the distance estimator 110 . The estimated direction of the object would be indicated by processing the object's assigned sound signal through an appropriate “head-related transfer functions,” 116 . Such “head-related transfer functions” can be used, for example, to make sound convincingly seem to originate from behind the listener when the loudspeakers are in fact in front of the listener. These “head-related transfer functions” represent the effect of a listener's head on the sounds that reach the insides of his ears. These head-related effects of course are strongly dependent on where sounds originate relative to the orientation of the listener. Thus seemingly natural sounds can be generated from position information of any sort. Alternately an array of loudspeakers could be used in place of head related transfer functions 116 and two loudspeakers 24 . These synthesized sounds can be used as an output of a warning system to alert someone that an object has come close enough to deserve their attention.
Additional Embodiment—A System for People with Asymmetrical Hearing
The systems described so far require that the person using them have balanced hearing in their left and right ears. Some people have a hearing problem that makes them less able to localize the source of a sound. This limitation is addressed by the concept shown in FIG. 12 . This system is a user-selectable configuration of the system of which one channel is shown in FIG. 5 . The microphones 118 and 120 are the same directional microphones used for the previous configurations. The left filter 122 and right filter 124 represent almost all of the signal processing functions. For this configuration the left and right filters are deliberately different so as to give the tire noise from a vehicle in the left blind spot a different tonal color than the tire noise from a vehicle in the right blind spot. This is easy to do because tire noise has a broad frequency spectrum, so different parts of the spectrum can be emphasized by the left and right filters. The level-dependent filters can be used for this left-right difference so that low-level signals are not given unbalanced tonal color. The outputs from the left and right filters are summed together by summer 126 . The output of the summer is a single common signal 128 that goes to both the left power amplifier and loudspeaker 130 , and the right power amplifier and loudspeaker 132 . Thus a person with hearing in only one ear can benefit from the system is several ways. She will be aware of nearby vehicles from sound coming from the system, and she will be able to differentiate by ear vehicles in the left and right blind spots because they sound different.
Conclusion, Ramifications, and Scope
The invention described here makes driving safer and more interesting by providing useful, natural-sounding aural information to the driver. Sounds that originate from nearby vehicles are useful. Sound that originate from the host vehicle is noise that provides no useful information about the traffic environment. The safety system must be able to discriminate against host vehicle noise, and this ability is a central technical challenge for this sound-based safety system.
The description above describes how a demonstration of this safety system has been implemented and suggests how a practical, mass-produced sound-based safety system can be realized. Extensions and useful implementation details will occur to those skilled in electronic, acoustic, and automotive arts. The directional microphones, for example, could be realized by using arrays of small individual transducers. Digital signal processing can be used in the signal processing.
The description above provides concrete examples of this invention and thus serves to aid understanding of the following claims. The claims alone describe the full scope and coverage of this invention.
|
A motor vehicle safety device allows the driver to hear nearby vehicles, so the driver can tell by ear when vehicles are in his blind spots, without significantly increasing the sound level inside the vehicle when there are no vehicles close to the host vehicle's blind spot. One benefit of this invention is the blind spot alert, or blind spot warning. Another benefit is that, because this invention communicates aural information from the host vehicle's environment to the driver, the driving experience is sensually richer and more interesting. The driver remains more alert and focused on the driving task. Elements of this invention, all of which are inexpensive, include directionally selective microphones ( 20 ) mounted on the vehicle, electronic signal processing ( 22 ), and loudspeakers ( 24 ) that are mounted close to the ears of the driver.
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention generally relates to a device for the electrical connection of two parallel busbars for busbar trunking systems with a common tensioning element in the form of a bolt. In the device, the busbars are arranged at the junction site in such a way that they rotate around the common tensioning element.
2. Background Information
When using busbar trunking systems, a problem often occurs wherein, because of structural conditions, the trunking systems must be equipped with flexible connecting elements, such as in situations when the busbars must be run along a wall which goes around a corner.
Connecting elements for busbars with flexible connecting leads are known, whereby a jacketing is ribbed to create the sense of optical continuation of the contours. Such a device is described and illustrated in German Laid Open Patent Appln. No. DE-OS 27 43 424. However, the device disclosed therein tends to be unsuitable for high currents, particularly for several hundred, or even thousands, of Amperes. A further disadvantage is that the connecting elements must usually be supported at the end sections.
An additional connecting element for the connection of two distributor channels, with which changes of direction can be effected, and which consists of a flexible jacket tube in which insulated cables are run, is described and illustrated in German Patent Publication Published for Opposition Purposes No. DE-AS 1255761. However, this device also tends to be unsuitable for high currents.
An additional connecting element consisting of a jacket tube comprised of chain links, in which tube the flexible leads are contained and whereby the chain links can be rotated in opposite directions around an axis, is described and illustrated in French Laid Open Patent Application No. 89 03 170. However, this connection element tends not to be suitable for higher currents.
U.S. Pat. No. 3,459,874 discloses the placement of busbars around a common bolt such that the busbars can be rotated. However, the housing at this point is essentially structurally complex and, furthermore, appears not to be suitable for high degrees of protection.
It is known, from U.S. Pat. Nos. 3,459,872 and 3,004,097, to have insulating plates with raised edges all around the busbar contour. This, however, does not form the housing. These documents also disclose the interdependent mobility of the insulating disks associated with the ends of the two connected busbars. However, the motion associated with that mobility is linear, and not rotary.
OBJECT OF THE INVENTION
The object of the invention is therefore to create a device, for the electrical connection of parallel busbars for busbar trunking systems, which makes it possible to easily change the direction of busbar trunking systems as desired.
The object of the invention is achieved by means of insulating disks, or cylindrical members, which can be rotated opposite to one another, which cylindrical members are placed between the busbars. The insulating cylindrical members are preferably so designed that they form a housing around the busbars, whereby the incoming and outgoing busbars are arranged in such a way that they can rotate like a hinge. Advantageous refinements of the invention are also disclosed hereinbelow.
Certain features of the invention disclosed hereinbelow result in the creation of a particularly favorable insulation, which is further improved by other features disclosed hereinbelow. For example, the gap between the insulating disks can be kept small enough that a high degree of protection is achieved. The number of required insulation plates can be reduced. An advantageous, favorable attachment of the rotatable insulation elements is created. The transition from the cylindrical housing to the busbar trunking or busbar housing is particularly well insulated. The simple electrical and mechanical connection of the busbars is improved. It is possible to use identical insulating plates. A particularly high degree of protection is achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, additional configurations and refinements of the invention and additional advantages of the invention are described below with reference to the attached drawings of one embodiment, which may be summarized as follows:
FIG. 1: A three-dimensional representation of the device according to the invention.
FIG. 2: An exploded representation of the device shown in FIG. 1.
FIG. 3a: A top view of a busbar.
FIG. 3b: A side view of a busbar.
FIG. 3c: An additional side view of this busbar.
FIG. 4a: A three-dimensional representation of the insulating plate used as a terminating element.
FIG. 4b: An additional three-dimensional representation of this insulating plate.
FIG. 5a: A three-dimensional representation of a middle insulating plate.
FIG. 5b: An additional three-dimensional representation of this insulating plate.
FIG. 6a: A side view of the bolt.
FIG. 6b: A top view of the bolt.
FIG. 7: A representation of the driver ring.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the device according to the invention with a set angle of about 90°. The device consists of the incoming busbars, which are indicated in FIG. 1 by only the reference number 2a, and the outgoing busbars 7 to 11.
In essence, it does not matter which of the busbars is the incoming or outgoing busbar but the above-discussed orientation must be taken under consideration in this example for the purpose of illustration. It must also generally be assumed that the incoming busbars 2a are fixed, while the outgoing busbars 7 to 11 are mobile, although alternative arrangements of fixed and movable busbars are possible.
As can be seen in FIG. 2 in particular, the housing 12 of busbars 2 to 6 preferably extends into the device 1. Busbars 2 to 6 can be electrically and mechanically connected to the busbar section 13 in a manner well-known to those of ordinary skill in the art.
Busbar 2 preferably terminates in an insulating disk 15, which is shown exploded, or taken-apart, in FIG. 2. Busbar 2 preferably has, at a terminal portion thereof, as, preferably, do all of the other busbars of the device, a portion 14 having an expanded surface area. This enlarged portion 14 is preferably completely embedded in the insulating disk 15 and serves to essentially improve the contact of busbar 2 with its neighboring, interfacing busbar.
Busbar 2 corresponds to, or interfaces with, busbar 7, wherein busbar 7 is preferably placed in such a way that it can rotate with respect to busbar 2. Insulating disk 15, like busbar 2, is preferably not rotatable, while insulating disk 16, which corresponds to busbar 7, preferably follows the rotation of busbar 7. Both busbars 2 and 7, as well as both insulating disks 15 and 16, preferably can be rotated with respect to one another around a bolt 21 common to all busbars 2 to 11 and insulating disks 15 to 20.
On the side of insulating disk 16 opposite to busbars 2 and 7, there is preferably an additional busbar 8 disposed in such a way that this inner insulating disk 16 preferably contains both busbars 7 and 8. Insulating disk 15 is preferably simultaneously the terminating element of the cylindrical joint 22, as can particularly be seen in FIG. 1. Disk 15 preferably has a seat 23 on the side opposite to busbar 2, which seat accepts a driver ring 24 in such a way that the driver ring 24 and seat 23 essentially cannot twist with respect to one another. This is preferably achieved by means of grooves 25 and projections 26, as can be seen in FIGS. 4a and 7.
The clamping function in the present invention will be described in more detail later. The insulating disk 17 adjacent to insulating disk 16 preferably corresponds to, or contains, busbars 3 and 4. As was assumed for purposes of illustration, this disk is preferably fixed, as are insulating disk 19 and busbars 5 and 6. Insulating disk 18, which corresponds to, or contains, busbars 9 and 10, is preferably rotatable, as is insulating disk 20, which preferably serves as a terminating section, whereby insulating disk 20 preferably corresponds to, or contains, busbar 11.
Insulating disks 15 to 20 preferably have raised regions 27 along the edges, as can be seen in FIGS. 4a, 4b, 5a and 5b, in such a way that when the insulating disks 15 to 20 are assembled together, the raised regions 27 essentially form a housing 41 in a simple manner.
Busbars 2 to 11 are preferably passed through openings 28 which are completely covered by insulating covers 29.
To avoid adversely affecting the contact of busbars 2 through 11, the insulating disks 15-20 are preferably sized in such a way that when put together, there is preferably a slight gap between them. The raised areas 27 have grooves 31 as seats for sealant, such that this gap may be sealed, to provide the device with a high degree of protection.
In addition to the driver ring 24, a spring washer 32 is also preferably placed in the seat 23, which spring washer, together with a spring washer 33 on the opposing end of the bolt and two plain washers 34, as particularly illustrated in FIG. 2, can preferably provide a pre-stress force, which pre-stress force is highly desirable. The bolt 21, as can particularly be seen in FIGS. 6a and 6b, preferably has a square enlargement of the cross-sectional area of the bolt 21, indicated at 35, for fitting into the driver ring 24 and a thread 37 on each end for fastening by means of nuts 38. Fastening can essentially thus be controlled by means of a defined pre-stress set at the factory on the cover 39 side in such a way that the customer only essentially has to tighten the nut 38 until reaching a stop. In addition, the bolt also preferably has an insulating conduit 36, which is shown in FIG. 2.
As can be seen in FIGS. 3b and 3c, there is also a preferably slight offset 30 to the busbars 2 to 11 which further ensures that a constant interval can preferably be maintained between busbars 2 through 11. The surface area enlargement 14 is preferably square and is preferably affixed to, or set firmly in, insulating disks 15 to 20 by means of the existing projections 40, which can be seen in FIG. 4b.
An additional possible embodiment, which is not illustrated here, would be to have the groove 31 completely encircle the circumference of cylindrical joint 22, whereby additional contact and insulating elements would possibly be required.
Preferably, the device can essentially be infinitely adjustable within a range of approximately 270°.
An adjustment scale can be provided to assist adjustment. Such a scale, for example, may be constituted by a set of markings about cylindrical joint 22, which markings could indicate a relative angular displacement between incoming busbars 2-6 and outgoing busbars 7-11.
The insulating covers 29 are preferably adapted to that of the housing of the busbar duct, and preferably include an area which is adapted to the cylindrical housing in such a way that an insulated transition is essentially created between both housings.
The disclosure now turns to a more detailed description of the components employed in a connection device according to the present invention.
FIG. 1 shows a connection device according to the present invention. Included in the device are a set of incoming busbars, indicated generally at 2a, and a set of outgoing busbars, indicated individually at 7 through 11. In FIG. 1, incoming busbars 2a are shown as being oriented at an angle of about 90° with respect to busbars 7 through 11.
It should be understood that the terms "incoming" and "outgoing", as applied herein, are intended primarily for differentiating between the two sets of busbars concerned, and are not to be taken as an absolute indication of the nature of each set of busbars. For example, it is conceivable to refer to busbars 2a as the "outgoing" busbars and busbars 7-11 as the "incoming" busbars. Also, for the purposes of illustration, busbars 2a can be thought of as being "fixed" and busbars 7 through 11 can be thought of as being "movable" although, indeed, both sets of busbars can essentially be thought of as both being movable with respect to each other.
In a manner to be described in greater detail below, a housing for busbar connections is indicated at 41. Additionally, the joint, preferably cylindrical, at which the incoming busbars 2a and the outgoing busbars 7-11 meet, is indicated in FIG. 1 at 22.
FIG. 2 more particularly illustrates the constituent components of a connection device according to the present invention and shows several of the components taken apart from the greater device. At this juncture, the busbars previously indicated at 2a can now be seen as individual busbars 2 through 6. It should be understood that, in a manner to be described more fully below, each of the incoming busbars 2-6 corresponds to, and in fact preferably interfaces with, one of the busbars 7-11.
As is typical in busbar connections, each set of busbars (2-6 and 7-11) preferably includes an outer housing 12, one for the incoming busbars 2-6 and one for the outgoing busbars 7-11. Thus, each housing 12 preferably surrounds its corresponding set of busbars (2-6 or 7-11) up to cylindrical joint 22. Indicated generally at 13 is a conventional busbar section to which, in a manner well-known to those of ordinary skill in the art, busbars 2-6 are preferably connected.
The busbars 2-6 and 7-11 all preferably meet at joint 22, which preferably includes a set of insulating disks 15-20. These insulating disks may be alternatively termed cylindrical members 15-20. Insulating disks 15-20 are all preferably stacked against one another to form a row of disks. In a manner described more fully below, each of these insulating disks 15-20 is preferably configured to accommodate therewithin a terminating portion 14 of at least one busbar.
In accordance with the present invention, a first incoming busbar 2 preferably terminates at a first insulating disk 15. Preferably, busbar 2, in a manner similar to preferably all other busbars in the connecting device, terminates at an enlarged portion 14 within its corresponding insulating disk, in this case disk 15. As shown, this enlarged portion is preferably in the form of a square-shaped portion 14. Preferably, disk 15 is configured such that enlarged portion 14 is essentially completely disposed within, or embedded in, disk 15. Enlarged portion 14 preferably has a hole in the center thereof to accommodate bolt 21.
Outgoing busbar 7 preferably terminates at disk 16, which itself is positioned adjacent disk 15. In accordance with the present invention, disk 16, positioned adjacent disk 15, is preferably rotatable with respect to disk 15. Likewise, busbar 7, extending from disk 16, is preferably angularly displaceable with respect to busbar 2. Similarly to busbar 2, busbar 7 preferably has an enlarged portion 14 within disk 16, which enlarged portion is preferably square-shaped and has a hole in a central portion therethrough. Accordingly, that hole is preferably configured to accommodate rod 21 therethrough, such that busbar 7 can essentially pivot, and disk 16 rotate, about bolt 21. It will be appreciated that disk 16 is preferably configured to accommodate busbar 7 in such a manner that disk 16 and busbar 7 will both undergo angular displacement in tandem. Such an observation can similarly be made with regard to busbar 2 and disk 15, if the two are indeed considered to themselves be angularly displaceable with respect to busbar 7 and disk 16.
At thus juncture, it serves to digress on the specific makeup of disk 15 and 16, as contemplated by the present invention. As has been stated heretofore, the enlarged portion 14 of busbar 2 preferably fits into disk 15 such that it is essentially disposed within, or "embedded" in, disk 15. With this in mind, it will be appreciated that disk 15 is preferably embodied by a circular, disk portion 27a and an outer wall portion 27, the outer wall portion 27 being essentially disposed about the circumference of the circular, disk portion 27a and, thus, being essentially cylindrical in nature. In this manner, it will be noted that the outer wall portion 27 of disk 15 preferably has a marked "height" dimension (indicated by "h" in FIG. 4b; that is, it extends from the circular disk portion in a direction perpendicular thereto, or parallel to a central longitudinal axis of bolt 21. By virtue of the height dimension of the outer wall portion, the enlarged portion 14 of busbar 2 can essentially, and preferably, be disposed within the outer wall portion 27 of disk 15 in such a manner that it may be considered to be embedded therewithin.
Disk 16 is preferably configured in a manner similar to that of disk 15, with one of the exceptions being that disk 16 is preferably configured to accommodate two busbars, in this case busbars 7 and 8. To this end, disk 16 also preferably comprises a central, circular disk portion 27a and an outer wall portion 27. In this case, however, the central disk portion preferably bisects disk 16 such that, preferably, approximately one-half of the outer wall portion 27 is, with respect to the axial direction of cylindrical joint 22, on one side of the circular disk portion 27a and approximately another half of the outer wall portion 27 is on the other side of the circular disk portion 27a. Thus, whereas disk 15 preferably includes essentially only one recess-type area for accommodating an enlarged portion 14 of a busbar, disk 16 preferably includes two such areas, wherein one such area is for accommodating enlarged portion 14 of busbar 7 and the other such area is for accommodating enlarged portion 14 of busbar 8. (Enlarged portions 14 of bus bars 7 and 8 are not shown in the drawings, but it should be understood that, preferably, they are disposed and configured in essentially the same manner as the enlarged portion 14 of busbar 2, which itself is shown in FIG. 2).
It will be appreciated that enlarged portions 14 of busbar 7 and busbar 8 are preferably insulated from one another by the central disk portion 27a of disk 16. It will further be appreciated that disk 15 and disk 16 are preferably configured such that, when placed adjacent one another, the outward facing portion of enlarged portion 14 of busbar 2 will essentially come into contact with the enlarged portion 14 of busbar 7 in order to afford an appropriate electrical contact connection between busbar 2 and busbar 7.
It will now be appreciated that the arrangement of interfacing busbars 2 and 7, as well as the configuration and relative positioning of disks 15 and 16, as described immediately above, preferably constitutes the basic principle on which the other disks (17-20) and busbars (3-6 and 8-11) are preferably arranged. Thus, disks 17-19 are preferably configured similarly to disk 16, such that:
disk 17 is preferably configured to hold enlarged end portions 14 of incoming busbars 3 and 4;
disk 18 is preferably configured to hold enlarged end portions 14 of outgoing busbars 9 and 10; and
disk 19 is preferably configured to hold enlarged end portions 14 of incoming busbars 5 and 6,
Additionally, disk 20 is preferably positioned at that end of cylindrical joint 22 opposite disk 15 and can preferably be configured similarly to disk 15, such that it is preferably configured to hold enlarged end portion 14 of disk 11.
It should now be understood that disks 15 and 20, which may be termed "end disks", are each preferably configured to hold enlarged end portions 14 of just one busbar each, whilst disks 16-19, which may be termed "intermediate disks", are each preferably configured to hold enlarged end portions 14 of two busbars each.
Accordingly, in a manner similar to that of busbars 2 and 7 already described, busbars 3-6 and 8-11 are preferably arranged among disks 16-20 such that:
outgoing busbar 8 preferably interfaces with incoming busbar 3, between disks 16 and 17;
outgoing busbar 9 preferably interfaces with incoming busbar 4, between disks 17 and 18;
outgoing busbar 10 preferably interfaces with incoming busbar 5, between disks 18 and 19; and
outgoing busbar 11 preferably interfaces with incoming busbar 6, between disks 19 and 20.
Again, it should be understood that, similarly to disk 16, in each of intermediate disks 17-19, the two enlarged end portions 14 of the corresponding busbars are insulated from one another by the central disk portion of the disk in question.
It will be appreciated that disk 15 preferably serves both to hold enlarged end portion 14 of busbar 2 and to cap one end of cylindrical joint 22. In the sense of the latter, disk 15 is preferably configured, as shown in FIG. 2 to include a seat 23. Seat 23 is preferably constituted by a generally cylindrical wall coaxial with respect to the outer wall portion of disk 15, yet having a smaller radius. Preferably disposed along the inward-facing surface of the cylindrical wall constituting seat 23 are a set of preferably semi-cylindrical indentations 25, wherein each of the indentations 25 can preferably be distributed uniformly about the circumference of seat 23. As an example, eight such indentations 25 may be provided.
As will be appreciated from FIG. 2, the bolt 21, which preferably serves as a focus for angular displacement of disks 15-20 and busbars 2-11, and which is preferably disposed through the centers of disks 15-20, preferably is configured to carry thereupon, at the end thereof adjacent disk 15, a driver ring 24. As shown, driver ring 24 is preferably constituted by a general disk shape, yet preferably includes a plurality of projections 26. Each of the projections 26 is preferably configured to be snugly accommodated in a corresponding one of the indentations 25 of seat 23. Thus, there is preferably a number and relative distribution of projections 26 corresponding to the number and relative distribution of indentations 25. In this manner, seat 23 is essentially configured to accommodate driver ring 24 in such a way that the two will not be angularly displaceable with respect to one another. It should be understood that, although the arrangement of projections 26 and indentations 25 is described herein as a preferable means for achieving this end, other possible arrangements may be used within the scope of the present invention. For example, a force-locking or friction-locking arrangement could possibly be employed.
It will now be appreciated that, when disks 15-20 are aligned with one another in a row, as illustrated in FIGS. 1 and 2, the outer wall portions of each disk will collectively serve to essentially create, along the axial direction of cylindrical joint 22, a housing 41 for the busbar connections. In other words, the outer wall portions 27 of disks 15-20 are preferably configured such that they combine to effectively form a housing for the enlarged end portions 14 of the busbars 2-11. In addition, as has been mentioned heretofore, each of the busbars 2-11 is preferably passed through openings 28 to cylindrical joint 22 wherein, however, each of the openings is preferably covered completely, or is essentially sealed, by insulating covers 29.
As has been mentioned heretofore, preferably, the disks 15-20 are preferably dimensioned such that, when the disks are aligned adjacent one another, there may preferably be a slight gap therebetween.
Particularly, the height (h) of the outer wall portion 27 in question can preferably be less than a thickness (t) of the enlarged end portion 14 of the corresponding busbar or, as shown in FIG. 5b, there may preferably be an arrangement of ribs, or webs, 42 on the surface of circular disk portion 27a so that enlarged end portion 14 may be held in such a way that enlarged end portion 14 can extend beyond the height (h) of outer wall portion 27. It should be understood that, in the case of intermediate disks 16-20 the height (h) should preferably be taken to represent essentially about one-half of the linear dimension of those disks in the axial direction thereof, or, put another way, the distance from circular disk portion 27a to either edge of outer wall portion 27.
Primarily, this may be done so as to avoid adversely affecting the contact of the busbars with each other. Preferably, disposed within each outer wall portion of each disk 15-20, on each of the sides which face another, adjacent disk, is a groove 31. As may be even more clearly seen in FIG. 5b, each such groove preferably has a slight depth in the axial direction of joint 22 and is preferably cut into the outer face surface of the outer wall portion, that is, into that end surface which is perpendicular to the longitudinal axis of joint 22. Groove 31 preferably extends in a circumferential direction and terminates at either side of opening 28. In order to seal the gap between disks mentioned above, each groove 31 can preferably serve as a seat, or recipient, for sealant.
Modifications on the basic principles outlined immediately heretofore can be made within the scope of the present invention, as long as neighboring disks, and their associated busbars, are arranged such that contact between enlarged end portions 14 of the busbars in question is afforded.
The disclosure now turns again to FIGS. 3a-7, which more clearly illustrate the preferred specific features of various components employed by the present invention.
As shown in FIGS. 3a to 3c, each busbar preferably includes a slight offset 30 when progressing from one end to the other thereof. The offset is preferably configured such that a constant interval can preferably be maintained between adjacent pairs of busbars.
FIGS. 4a and 4b show opposing views of an insulating disk, such as disk 15, which may be used as a terminating disk. It will be noted that opening 28 is preferably provided in outer wall portion 27 to accommodate a busbar. It will also be noted that a set of projections 40 are preferably provided to firmly hold the enlarged portion 14 of the busbar in question in such a manner that the bus bar essentially cannot rotate within the disk in question, but essentially will rotate along with the disk. Particularly, the projections 40 are preferably configured as minor bumps distributed essentially uniformly about the inner periphery of outer wall portion 27, and are preferably four in number. Of course, it is possible, within the scope of the present invention, to utilize other possible arrangements for firmly holding an enlarged end portion 14 of a busbar within a disk.
FIGS. 5a and 5b show opposing three-dimensional views of an insulating disk, such as any of disks 16-19, which may preferably be used as an intermediate disk.
FIGS. 6a and 6b show different views of bolt 21.
Finally, FIG. 7 shows a more detailed view of driver ring 24, particularly with its projections 26 and its preferably square center opening for accommodating therewithin the square portion 35 of bolt 21. In this manner, rotation of bolt 21 with respect to driver ring 24 can be prevented.
It should now be appreciated that, within the scope of the present invention, modifications can be made on the basic principles set forth hereinabove. For example, insofar as joint 22 has been referred to heretofore as a "cylindrical joint", it should be understood that it may be possible, within the scope of the present invention to provide a joint which is not necessarily generally cylindrical in shape. Likewise, it is conceivable to use a number of disks and busbars different from that contemplated hereinabove. Many such departures from the preferred embodiments disclosed hereinabove can be made while still remaining within the spirit and scope of the invention.
One feature of the invention resides broadly in the device for the electrical connection of parallel busbars for busbar trunking systems with a common tensioning element in the form of a bolt, in which device the busbars are arranged at the junction site in such a way that they rotate around the common tensioning element, characterized by the fact that insulating disks 15 to 20 which can be rotated opposite to one another are placed between the busbars 2 to 11, which insulating disks are so designed that they form a housing 41 around the busbars 2 to 11, whereby the incoming and outgoing busbars 2 to 11 are placed in such a way that they can rotate like a hinge.
Another feature of the invention resides broadly in the device, characterized by the fact that for each incoming busbar 2, 3, 4, 5, 6, there is an insulating disk 15, 17, 19, and that there is an additional insulating disk 16, 18, 20 which can be rotated opposite to the incoming busbar 2, 3, 4, 5, 6 and the corresponding insulating disk 15, 17, 19.
Still another feature of the invention resides broadly in the device, characterized by the fact that the insulating disks 15 to 20 have raised edges and form a cylindrical housing 41 when put together, and that the insulating disks 15 to 20 have an opening 28 for the passage of the busbars 2 to 11.
Yet another feature of the invention resides broadly in the device, characterized by the fact that the inner insulating disks 16, 17, 18, 19 are designed as common insulating disks 16, 17, 18, 19 for two busbars 3 to 10, whereby one side of these insulating disks 16, 17, 18, 19 is assigned to one busbar 7, 8, 3, 4, 9, 10, 5, 6.
Another feature of the invention resides broadly in the device, characterized by the fact that an insulating disk 15, which is used as a terminating element, has a seat 23 for a driver ring 24, which is embedded in this seat in such a way that it cannot twist and is firmly attached to the bolt 21.
Still another feature of the invention resides broadly in the device, characterized by the fact that in those areas in which the busbars 2 to 11 pass out of the cylindrical housing 40, there are insulating covers 29 which create an insulated transition from the busbars 2 to 11 to the busbar duct.
Yet still another feature of the invention resides broadly in the device, characterized by the fact that the busbars 2 to 11 have a surface area enlargement 14.
Another feature of the invention resides broadly in the device, characterized by the fact that the surface area enlargement 14 is square.
Still yet another feature of the invention resides broadly in the device, characterized by the fact that the busbars 2 to 11 are alternately offset in the area extending passing out from the housing 41.
Yet another feature of the invention resides broadly in the device, characterized by the fact that the insulating disks 15 to 20 have a groove 31 for sealant.
All, or substantially all, of the components and methods of the various embodiments may be used with at least one embodiment or all of the embodiments, if any, described herein.
All of the patents, patent applications and publications recited herein, if any, are hereby incorporated by reference as if set forth in their entirety herein.
The details in the patents, patent applications and publications may be considered to be incorporable, at applicant's option, into the claims during prosecution as further limitations in the claims to patentably distinguish any amended claims from any applied prior art.
The appended drawings, in their entirety, including all dimensions, proportions and/or shapes in at least one embodiment of the invention, are, if applicable, accurate and to scale and are hereby incorporated by reference into this specification.
The invention as described hereinabove in the context of the preferred embodiments is not to be taken as limited to all of the provided details thereof, since modifications and variations thereof may be made without departing from the spirit and scope of the invention.
|
The known arrangements of low-voltage energy distribution include connecting elements for busbar trunking systems with which, while a change of direction is possible, the currents are limited. The new device is intended to make it possible to easily change directions, even with high currents. To achieve this object, the invention teaches that the busbars at the junction site are placed in such a way around a common tensioning element that they can be rotated.
| 7
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a method and a device for preparing process gases for heat treatments of metallic materials/workpieces in industrial furnaces, wherein the heatable process gases include a treatment medium as a protective gas and/or for example a reaction gas.
[0003] 2. Description of the Related Art
[0004] In general, a process gas for the heat treatment of metallic materials/workpieces in industrial furnaces is understood by a person skilled in the art to be a treatment medium such as for example a protective gas containing carbon monoxide, hydrogen and nitrogen, carbon dioxide oxygen and/or steam, and/or for example a reaction gas containing hydrocarbons for “carburisation processes”, which relate to the carburising or carbonitriding of metallic materials/workpieces.
[0005] Thus, in one of the steps of carburisation for example, a gas containing hydrocarbons is added to a process gas reacting in the treatment chamber to create the requisite furnace atmosphere. In this process, the individual components of the process gas are intended to create a controllable state of equilibrium in the furnace atmosphere so that the carbon is able to be transferred from the gas atmosphere to the metallic materials/workpieces in a manner that is both controlled and reproducible. Automatic control of processes of this kind is assured by regulation of the C level, such as is described in DE 29 09 978 and has become successfully established in industrial practice for the heat treatment of metallic materials/workpieces. However, the control of the C level solved so advantageously here fails to make use of catalytically usable potential with regard to modern requirements.
[0006] Thus for example, in his report entitled “Gas mixtures fed hot into the furnace chamber as the atmosphere for heat treatment of steel”, (HTM 30 (1975) Vol. 2, p. 107-) W. Goring had already suggested using a protective gas retort with catalyst bed integrated in the industrial furnace to feed hot process gas into the treatment chamber, regardless of the temperature there, as a way to speed up the level of activation of a furnace atmosphere. For the purposes of modern specifications, this method is associated with a number of drawbacks, because it requires constant replenishment with fresh gas, that is to say regulation is effected by enriching the gas, and harmful emissions must be contended with.
[0007] The use of catalysts is also described in other documents, such as for example DE 36 32577, DE 38 88 814, DE 40 05 710, DE 691 33356, and DE 44 16 469.
[0008] The following text discloses the treatment of metals in a carburised atmosphere
in accordance with GB 1,069,531, in accordance with U.S. Pat. No. 3,620,518 for the treatment of workpieces in hardening furnaces having a catalyst lining of nickel oxide, which has been applied to the ceramic interior wall and increases the available surface area, in accordance with U.S. Pat. No. 4,294,436 with a furnace for heat treatment of metal parts with a protective atmosphere in furnaces having catalytic walls of Ni, in accordance with U.S. Pat. No. 5,645,808 for catalytic oxidation with carbon compounds in gas streams, and in accordance with US 2006/0081567 with plasma-supported workpiece treatment, and in accordance with JP 62199761.
[0015] In order to improve the process effect of the gas feed in the abovementioned industrial furnaces, it has already been suggested in DE 10 2008 029 001.7-45 to tailor the supply of hydrocarbon to specific carburisation requirements so as to economise on protective gas and reduce heat energy losses, to adjust the C potential in the protective gas and prevent uncontrollable and/or undesirable reactions. This resulted in the creation of a new protective gas recirculation system for gas carburisation. In this, the components carbon dioxide, oxygen and steam react with a supplied hydrocarbon in a processing area of the treatment chamber of a species-related industrial furnace to yield carbon monoxide and hydrogen again, in this case catalytically. In this way, previously “used” protective gas, that is to say a protective gas with a low C potential, may be advantageously reprocessed. The C potential is adjusted in the processing area of the treatment chamber. The “processed” protective gas may then be fed back into the treatment chamber at one or more points, thus establishing a truly circular process for gas carburisation.
[0016] According to this new method
the components carbon dioxide, oxygen and steam react with a fed supply of a hydrocarbon as the reagent gas to yield carbon monoxide and hydrogen in a processing area equipped with catalyst bed in an industrial furnace, the protective gas has elevated C potential, and the C potential is adjusted, the catalytic reaction is accelerated, and the protective gas processed in this way is returned to the treatment chamber in a recirculation system.
[0021] The purpose of this was to improve the process of uniform carburisation and enable costs for process gas to be reduced further.
[0022] However, more extensive research was needed in order to ensure even more reliable and reproducible heat treatment for industrial furnace operators, because the method described above requires the treatment chamber and the heating chamber to be as impermeable as possible, and reaction temperatures in the heating chamber do not exceed for example 850-950° C.
[0023] In this context, the quality requirements for case hardening had to be analysed again, particularly with respect to parameters such as
case hardening depth/carburisation depth, surface hardness/surface carbon content, perlite/troostite seam, residual austenite content, carbide formation, surface oxidation depth as well as dimensional and shape changes and core hardness
if they were to be correlated even indirectly with the degree of carburisation. In this case, the depth of carburisation and the carbon concentration were both significant factors.
[0032] In the existing industrial carburisation methods, such as gas carburisation in atmosphere furnaces and low-pressure carburising in vacuum furnaces, the objective is one that is familiar to those skilled in the art: all parts of the workpieces in a batch must be carburised with total uniformity, to the same C content and the same carburisation depth.
[0033] With gas carburisation, in which the furnace atmosphere is adjustable via equilibrium reactions, this may be achieved more effectively than by non-equilibrium carburisation using hydrocarbons.
[0034] Accordingly, gas carburisation, that is atmospheric gas carburisation, is the preferred process.
[0035] In this process, the following known, various process steps are performed, it is essential to take all of them into account to ensure reproducible, even carburisation:
1. The gas reactions for creating the carburising gas components in the atmosphere. 2. Gas phase homogenisation for transporting the carbon-containing molecules in the gas phase and to the part to be carburised. 3. Diffusion transport, that is to say transport of the carbon-containing molecules by the flow boundary layer to the surface of the part. 4. Dissociation and adsorption relating to splitting of the molecules on the surface of the part. 5. Absorption, that is to say the uptake of the carbon by the part surface. 6. Diffusion as the means of transporting the carbon into the part.
[0042] As has already been described in the outcome in DE 10 2008 029 001.7-45, the decisive reactions for carburisation in the carburisation atmosphere are:
[0000] CH 4 C+2H 2 Methane dissociation
[0000] 2CO C+CO 2 Boudouard reaction
[0000] CO+H 2 C+H 2 O Heterogeneous water-gas reaction
[0000] CH 4 +CO 2 2CO+2H 2 Enrichment reaction 1
[0000] CH 4 +H 2 O CO+3H 2 Enrichment reaction 2
[0043] In order to build on the advance represented by DE 10 2008 029 001.7-45 with regard to the prior art, it is important to influence the kinetics and also the direction of these reactions, because they depend to a large degree on the temperature which—as was explained previously—is regularly limited to 850-950° C., but are not enabled at temperatures significantly below this.
[0044] Since the transportation of the carbon carrier is usually effected through forced convection, the powerful circulation of the atmosphere within the heating chamber helps to ensure that the carbon carriers are thoroughly mixed and the flow thereof is then directed towards the part.
[0045] Thus, for example, the following relationship is known to apply for mass transfer when the atmospheric flow is directed towards a flat workpiece panel
[0000]
β
L
=
0.664
×
V
·
L
ν
×
ν
D
3
×
D
L
,
[0000] wherein a coefficient of diffusion is represented by D;
a length of the part to which flow is directed is represented by L; a flow speed is represented by V; and a kinematic viscosity is represented by ν.
[0049] Accordingly, as the flow speed increases the effective coefficient of mass transfer β also becomes larger, and it is this relationship that must be used even more efficiently.
[0050] The known relationship to the effect that the speed of diffusion through the flow boundary layer is essential and cannot be influenced by changing the flow speed had to be studied further.
[0051] In this regard, it is the magnitude of the coefficient of diffusion in the gas that is decisive, and this is critically dependent on temperature and pressure. In an initial approximation—also known—, doubling the pressure halves the diffusion coefficient.
[0052] The thickness of the boundary layer may be determined using the relationship familiar to those skilled in the art
[0000]
δ
(
x
)
=
4.64
ν
·
x
V
∞
[0000] where thickness of the boundary layer is represented by δ(x);
distance from the edge of the part is represented by x; and speed of the gas farther from the part is represented by V ∞ .
[0055] It may be observed that increasing the speed of the gas reduces the thickness of the boundary layer, which in turn shortens the transport time to the surface. Use of this relationship must be improved as well.
[0056] Finally, the splitting reaction of the carbon monoxide on the part according to the known equation
[0000]
C
O
⇒
C
+
1
2
O
2
[0000] is also the underlying reaction for transferring carbon for gas carburisation in CO/H mixtures, which, besides still other reactions, enables the carburisation effect of the atmosphere to take place continuously, as is shown in FIG. 1 , which illustrates known findings.
[0057] In order to arrive at advanced solutions proceeding from this known basis, the creative approach had to be applied and exploited in a technologically new way, in particular that
the speed of carbon transfer depends on the property of the atmosphere, and the oxygen generated during splitting must be bound and then removed by convection.
[0060] Since hydrogen is needed for this, the speed of dissociation of the carbon monoxide in the presence of a sufficiently large quantity of hydrogen becomes the determining parameter.
[0061] The speed at which the carbon is absorbed by the workpiece surface in turn depends on the difference between the carbon activities in the atmosphere and in the part. This means, if the carbon activity in the gas is greater than in the part, the net effect is a transfer of the carbon to the workpiece surface.
[0062] In practice, this difference may be characterized in pure iron and unalloyed steel by the difference between the C potential and the carbon content in the workpiece surface, wherein the diffusion of the carbon can be described by Fick's laws, which will not be further elaborated on here.
[0063] Accordingly, a new inventive task must address the fact that diffusion depends on the temperature and the progression of the concentration of carbon C in material having depth x.
SUMMARY OF THE INVENTION
[0064] In the context of these detailed investigations, the object of the invention is to provide a method for preparing process gases for heat treatments of metallic materials/workpieces in industrial furnaces of the species described, by which at least one of the components containing a process gas, having been practically completely prepared, and also homogenised and heated, is fed into the at least one treatment chamber thereof and is able to be connected by a device both to newly manufactured as well as and particularly to units of industrial furnaces that have already been in service, such that the process gas is able to be used for heat treatment in the respective industrial furnace economically and with low emissions, and ideal carburisation conditions in terms of
temperature, gas flow towards the parts, homogenisation of the gas phase, and rapid reaction kinetics
are created uniformly throughout the treatment chamber of the industrial furnace in accordance with the six process steps listed above.
[0069] Unlike the prior art, the invention is therefore intended for industrial furnaces, particularly those referred to as atmosphere furnaces, in which previously the components of the process gas to be heated were normally prepared in the treatment chamber as the heating chamber, before they were introduced for carburising or carbonitriding heat treatment of metallic workpieces/materials, wherein in an upstream process and with a device that may be connected to the industrial furnace, the process gas is practically entirely prepared beforehand and then fed into the treatment chamber with direct effect so that the heat treatment process may be carried out in a more efficient, more environmentally responsible manner for operators in the industry, and to provide a corresponding unit that is able to be retrofitted in older industrial furnaces.
[0070] With this statement of the object, approaches to finding inventive solutions are informed by the fact that the temperature in both the treatment chamber and the heating chamber of modern industrial furnaces can be maintained with a uniformity of at ±5° C. This means that when the heating and soaking phase is finished, all austenised parts are at the same temperature.
[0071] If special gas feed devices are also arranged inside the heating chamber, they already enable the remaining convective heat transfer portions to be used in a defined way to achieve the all-important uniformity of temperature throughout the entire batch chamber. In certain cases, it is then possible to achieve tolerances of just ±3° C.
[0072] Ideal temperature uniformity can only be established if the gas flow is directed to all parts optimally. Accordingly, excellent temperature uniformity needs another circulation system, or more importantly one that has been devised differently from previous systems, and which must be considered as a unit.
[0073] Besides establishing temperature uniformity and optimal exposure of the parts to the carburising gas flow, a third aspect of circulation to be considered is homogenisation of the atmosphere, which enables the gas reactions for initiating consistent carbon activity (C level) to be sustained throughout the batch chamber and in the treatment chamber.
[0074] In order to set a defined atmosphere, continuous gasification with carrier and enrichment gas must always be adjustable directly via the circulation system.
[0075] The continuous interaction between the furnace atmosphere and the surface of the workpiece, and the associated transfer of carbon from the gas causes the carbon activity (C level) in the atmosphere to change constantly, so that it is imperative to measure this variable. This is assured with the aid of the oxygen probe (and thermoelement) on the basis of an oxygen partial pressure measurement. Natural gas (or another hydrocarbon) is added to the air to adjust the C potential.
[0076] Accordingly, carburisation of the parts and the enrichment of the process atmosphere necessitated thereby leads to a permanent imbalance therein. Balanced adjustment of the C level must create a quasi-stationary equilibrium in generating a generally balanced atmosphere despite these locally occurring imbalances, and this is illustrated in FIG. 2 to provide a better understanding of the object of the invention in the circular gas carburisation process that is central to the invention.
[0077] In this figure, the carburisation reactions responsible for carburisation, all of which lead to the formation of carburising carbon monoxide, are shown on the left.
[0078] One carburising reaction appears at top right in FIG. 2 , that is unbalanced carburisation due to methane dissociation. A locally occurring, impermissible increase in the concentration of methane in the CO- and H 2 -containing process atmosphere can result in partial overcarburisations on the parts, which then in turn cause residual austenite and/or carbide formation. Methane dissociation is not normally detected by the sensors, and consequently it is most often perceived as an interference factor during the process.
[0079] However, it is possible to achieve the interaction between gasification and adjustment of the C level within the atmosphere according to an internal development stage, wherein this interaction is defined by the maintenance of a tolerance of ±0.05% C in the surface carbon content of the workpiece, and results in uniform carburisation of the surface layer.
[0080] If a person skilled in the art assumes the degrees of effectiveness that are achievable using the carburisation gasification techniques that are standard today, he would recall that in operating industrial furnaces
thermal losses occur such as in the flare when the protective gas is burned off, and approximately 98% of the carbon that is fed into the carburisation process is not available for carburising at all, instead it is merely burned off, so that the degree of efficiency in carburisation is thus less than 2%, and other technologies are addressing the question of how to exploit the heat energy that is discharged into the ambient air.
[0085] A new gasification process was already proposed in the document DE 10 2008 029 001.7-45 cited above, according to which the protective gas is no longer burned off, but instead is returned to the heating chamber by recirculation after undergoing an intermediate step as preparation, and is thus no longer dissipated, but reused.
[0086] The purpose of this invention is now to take the process another important step forward, in which the reactions proceeding within the heating chamber due to carburisation, such as:
[0000] 2CH 4 +O 2 2CO+4H 2
[0000] CH 4 +CO 2 2CO+2H 2
[0000] CH 4 +H 2 O O CO+3H 2
[0000] have been examined again with regard to more interference factors.
[0087] According to this, the intention was
to enable better use to be made of the catalytic potential, to ensure that above 850° C. the temperature actually required in the furnace chamber does not result in reprocessing of protective gas that has already been “consumed”, a process that while advantageous on its own has negative effect on the reactions, to ensure that the catalytic effect is guaranteed regardless of the temperature in the furnace chamber, that is to say significantly above but also below temperatures, and to ensure that the enrichment gas is passed directly through the catalyst, and not fed into the furnace chamber first.
[0092] Unlike previous approaches, in the present invention the protective gas is to be generated and enriched in a distinct preparation process, separately from the batch, so that it is possible to expose the batch to a gas atmosphere that is consistently homogeneous. As a result, streaks or inconsistencies are not formed when natural gas is introduced into the heating chamber for the purpose of enrichment. Undesirable local overcarburisations, such as are caused by unbalanced carburisation due to the methane dissociation described above, are to be almost entirely prevented.
[0093] The low environmental impact of the method is demonstrated by its carbon footprint. CO 2 emissions are lowered significantly by the extensive economies in process gas.
[0094] Although it has not yet been possible to use the information gained from DE 10 2008 029 001.7-45 for a wide range of industrial furnaces of the species described in the introduction that are already in service, a further field of application is now accessible by virtue of the fact that it is possible to retrofit existing industrial furnaces, and thus achieve even greater efficiency than was offered by the method according to DE 10 2008 029 001.7-45. In particular, older inventories of industrial furnaces that are at operators' sites and still operable are able to be retrofitted according to the invention.
[0095] Starting from the prior art situation described in the preceding, this newly gained knowledge may now be applied to a wide range of currently operating industrial furnaces of the technological species described in the introduction. Although some of these solutions were implemented, for example a protective gas retort with protective catalyst bed integrated in the industrial furnace, they were only implemented as integrated components of furnace units and involved the disadvantageous supply of enrichment gas but not gas recirculation.
[0096] It was also typical and disadvantageous in such arrangements that the process gases were always prepared under the conditions prevailing in the respective treatment chamber as the heating chamber and directly associate functional units. Accordingly, it was not possible to prepare the gases under higher or lower temperature conditions.
[0097] The present invention now makes it possible for operators' existing older industrial furnaces, which are still serviceable but are not yet being operated with the full range of commercial/technological and ecological advantages, to be run in an environmentally conscious manner and with economical use of energy carriers.
[0098] The invention provides a method for preparing process gases for heat treatments of metallic materials/workpieces in industrial furnaces, by which at least one of the components containing a process gas, having been practically completely prepared, and also homogenised and heated, is fed into the at least one treatment chamber thereof and is able to be connected by a device both to newly manufactured as well as and particularly to units of industrial furnaces that have already been in service, such that the process gas is able to be used for heat treatment in the respective industrial furnace economically and with low emissions.
[0099] Unlike the prior art, the invention enables industrial furnaces, particularly those referred to as atmosphere furnaces, in which previously the components of the process gas to be heated were normally prepared in the treatment chamber as the heating chamber, before they were introduced for carburising or carbonitriding heat treatment of metallic workpieces/materials, an upstream method and a device that may be connected to the industrial furnace enables the process gas to be processed in the manner explained in the preceding, wherein the actual preparation process is able to take place and is favoured by higher reaction temperatures up to about 1250° C. and at significantly lower reaction temperatures, that is to say higher and lower than the temperature of 850° C.-950° C. in the treatment chamber, and that in this context particularly accelerated reactions such as enrichment and generation, as described for example by
[0000] 2CH 4 +O 2 →2CO+4H 2
[0000] CH 4 +CO 2 →2CO+2H 2
[0000] CH 4 +H 2 O→CO+3H 2
[0000] are encouraged and able to take place, so that this process gas may then be fed directly to the treatment chamber of the industrial furnace, so that the carburising reactions there, for example
[0000] 2CO→C+CO 2
[0000] CO+H 2 →C+H 2 O
[0000] CO→C+0.5O 2
[0000] are able to take place with direct effect at the usual, cited temperatures.
[0100] In this context, other reaction equations in keeping with the central idea of the invention may also take place depending on the corresponding heat treatment method and the gas components for preparing the process gas and the treatment-related consumption thereof for the purposes of central idea of the invention.
[0101] The entire heat treatment process may thus be carried out by operators in the industry in an even more efficient and environmentally conscious manner, for which purpose the corresponding unit has been created so that according to the invention it is able to be retrofitted in older industrial furnaces.
[0102] In summary, the sequence of the method is configured according to the invention such that the process gas, which includes at least
a first treatment medium as a protective gas, which also contains the components carbon dioxide, oxygen and steam in addition to the minimum components carbon monoxide, hydrogen and nitrogen, and a second treatment medium as a reagent gas, which initiates a carburising or carbonitriding treatment, a) is prepared separately with regard to at least one of the properties thereof that is essential for heat treatment, such as chemical reactions, temperatures, pressures or flow speeds, in a preparation chamber of an external module outside of the treatment chamber and the industrial furnace at temperatures of up to 1250° C. and with the use of a compressor according to the following reactions, for example,
[0000] 2CH 4 +O 2 →2CO+4H 2
[0000] CH 4 +CO 2 →2CO+2H 2
[0000] CH 4 +H 2 O→CO+3H 2
[0000] such that the components such as carbon dioxide, oxygen and steam react catalytically with a hydrocarbon as the reagent gas to form carbon monoxide and hydrogen, and after this reaction the protective gas has a required C potential, after which
b) the process gas thus prepared is forced out of the preparation chamber of the external module by the compressor and fed to the treatment chamber in the industrial furnace, having been compressed, homogenised and accelerated, and is directed via single-point or multipoint feeds towards the materials/workpieces, where the carburising or carbonitriding treatment is carried out according to the following reaction, for example,
[0000] 2CO→C+CO 2
[0000] CO+H 2 →C+H 2 O
[0000] CO→C+0.5O 2
[0000] wherein
c) at least one treatment medium of the process gas is recirculated and is recovered for use in the preparation described in step a).
[0108] Experience has shown that the gas passing through pipelines can undergo a reactive breakdown, depending on the length and diameter of required pipe connections between the treatment chamber and preparation chamber.
[0109] This is to be avoided by rapidly cooling the gas after it exits the treatment chamber, or even after it exits the preparation chamber.
[0110] As an alternative, achieving the high gas temperature by insulating and, if necessary, heating the pipelines also constitutes a suitable means for avoiding gas breakdown.
[0111] In the device for implementing the method, the respective pipeline must correspondingly have allocated to it a cooling aggregate, e.g., designed as ribbed pipe piece with ducted or induced cooling, or an insulation or heater, in particular directly behind the treatment chamber or behind the preparation chamber.
[0112] With this method, it is possible to produce a process gas that has been compressed, homogenised, and heated to a higher, but also to a lower temperature, which process gas together with at least one second treatment medium as the reagent gas containing a hydrocarbon and also ammonia as components causes carburising and/or carbonitriding during heat treatment of materials/workpieces or the treatment medium thereof, wherein at this point at least one treatment medium of the process gas fed into the treatment chamber of the industrial furnace is recirculated in the treatment chamber for separate reconstitution.
[0113] The process gas is processed separately and catalytically in the module described to yield a circulation/mixture that is optimised for heat treatment and is able to overcome flow resistances with the assistance of the compressor, for subsequent, direct use in heat treatment in the industrial furnace.
[0114] By the time it reaches the industrial furnace, the process gas has thus been prepared, fully reacted, compressed, homogenised and accelerated, so that the carburising effect is able to take place directly on the workpieces/materials directly in the treatment chamber of the industrial furnace without the need to perform the reactions and preparation in the treatment chamber, as previously, and then control/adjust the treatment medium according to the C level as a function of the workpieces/material that are to be treated.
[0115] The composition of the gas siphoned out of the treatment chamber and relayed into the preparation chamber varies as a function of the level of thermochemical gas reactions and gas metal reactions taking place in the treatment chamber.
[0116] In terms of the input/output monitoring described in the invention, the gas is to be optimally prepared in the preparation chamber by precisely adjusting the unburned gases being fed into the preparation chamber, e.g., natural gas and air, along with other hydrocarbons and other oxidizing gases, relative to a supplied overall quantity and ratio of supplied individual quantities, based on the quantity and composition of the gas to be prepared and the desired preparation result.
[0117] In a thermochemical heat treatment process, such as carburisation or carbonitration, the overall composition in the treatment chamber varies throughout the entire duration of the process. Therefore, an optimally prepared reaction gas cannot be generated by supplying a chronologically constant quantity of unburned gas in a chronologically constant ratio of the individual unburned gas components into the preparation chamber.
[0118] The inventive process of optimal gas preparation is set up therein from a procedural standpoint by measuring the composition, streaming quantity and temperature of the gas to be prepared after exiting the treatment chamber and before entering the preparation chamber, and of the prepared gas after exiting the preparation chamber and before entering the treatment chamber, and continuously changing the entire quantity of unburned gas fed into the preparation chamber along with the relative quantities of individual unburned gas components relative to each other, so as to achieve an optimal preparation result.
[0119] The process creates a closed control loop, in which target variables for the prepared gas are defined based on an analysis of the gas to be prepared, in particular with respect to CO content and CH 4 content, and potentially also with respect to H 2 content and CO 2 or H 2 O content, wherein they are reached by varying the quantities of individual unburned gas components fed to the preparation chamber, and monitored and readjusted as needed by analysing the prepared gas.
[0120] The corresponding device for this control loop for assuring the quality of the prepared gas consists of gas composition analysers, in particular for gas components CO and CH 4 , but also CO 2 and H 2 , and potentially H 2 O and/or O 2 . Sensors for determining the quantity and temperature of the gas entering the preparation chamber for preparation and exiting the preparation chamber after prepared, controllable metering valves and rate meters for the unburned gases fed into the preparation chamber, as well as a programmable control system for processing the measuring data, calculating the target variables, and relaying the control signals to the actuators, such as valves, etc.
[0121] In this way, a treatment stimulus that increases the effectiveness of the heat treatment is created immediately in the treatment chamber according to at least one of the parameters such as temperature, CO content or pressure through integrated monitoring/measurement/control/adjustment of the atmosphere in the treatment chamber or the temperature of the process gas. In this context, the monitoring/measurement/control/adjustment is further supported in the treatment chamber by at least one of the parameters, such as oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere.
[0122] With this method, it is advantageously possible to add air from a cold area to at least one treatment medium of the process gas that is to be prepared.
[0123] The method as a whole is characterized in that the prepared process gas is extracted from the treatment chamber again and fed back into the external module, prepared again as before, and forwarded back to the treatment chamber of the industrial furnace.
[0124] For the accelerating and compressing circulating/mixing motion of at least one of the treatment media in the process gas, air is fed from a cold area to at least the one compressor located in the external module.
[0125] For control and adjustment, software is used that adds another treatment medium, for example a reagent gas, by segments in pulsed, timed, and/or constant quantities from at least one treatment medium of the process gas, for example the atmosphere in the treatment chamber.
[0126] In this way, if carburisation causes the concentrations of CO 2 , H 2 O and O 2 to increase and the C level to fall in the heating chamber, this diluted gas is fed back into the preparation chamber, which is separate and thus locally isolated from the heating chamber.
[0127] Here, the C level is enriched by the addition of finely metered quantities of natural gas, initiating the reactions described earlier, such as
[0000] 2CH 4 +O 2 2CO+4H 2
[0000] CH 4 +CO 2 2CO+2H 2
[0000] CH 4 +H 2 O CO=CO+3H 2
[0000] and reducing the concentrations again.
[0128] However, natural gas is only added to the preparation chamber if the C potential falls. While enrichment is not required, no natural gas is added. Natural gas only needs to be introduced to enrich the mixture, and then in the smallest quantities, when the C potential falls as a result of carburisation (and not due to flushing, as was previously the case). In the ideal operating state, therefore, carbon in the form of natural gas only needs to be added in a quantity necessary for carburising the part, in order to lower the C level, air may be introduced.
[0129] No additional protective gas generator is required to ensure the process reliability of an industrial furnace, because this function is performed by the external preparation chamber.
[0130] The heat treatment process workflow is configured such that, after the heating chamber has been loaded with the batch of materials/workpieces, flushing gasification with protective gas generated by the system is carried out for a defined initial period so that the desired furnace atmosphere is restored as quickly as possible. For this, a natural gas/air mixture is fed into the preparation chamber, a solenoid valve to a burn-off system equipped with a pilot burner is opened, and the furnace is flushed with protective gas. After the flushing period, all valves on the burn-off system area closed and recirculation is started. In this way, the protective gas is recirculated to the external preparation chamber of the separate module and may be adjusted to the desired C level and prepared by the metered addition of natural gas.
[0131] The fully prepared protective gas can also be introduced into the heating chamber via a plurality of points as a multipoint feed inside the heating chamber. In this way, is it possible to establish a homogeneous gas atmosphere more quickly than was the case with conventional methods. In addition, the geometry of the treatment chamber may be optimised for a given application by using a selectable single-point or multi-point feed system.
[0132] For example, if atmospheric heat treatment furnaces are equipped with a strong internal gas circulation system and given a multi-point feeding process, the reaction gas to be prepared can be siphoned out of the treatment chamber, and the gas prepared in the preparation chamber can be returned to the treatment chamber via a single interface in the form of a coaxial dual pipe with an inner pipe that is somewhat longer than the outer pipe.
[0133] The reaction gas to be prepared is here advantageously siphoned off via the inner pipe, while the prepared gas is returned via the outer pipe.
[0134] As a result, minimal structural changes, if any, are normally required when retrofitting existing heat treatment furnaces with the gas preparation system according to the invention. It is in this way that the overall decisive advantage of the method, as described in the preceding, becomes evident. The protective gas is generated and enriched separately from the batch, that is to say the batch is constantly exposed to a homogeneous gas atmosphere. No streaks or inconsistencies occurred due to the introduction of natural gas into the heating chamber for enrichment, so that undesirable local over-carburisations, such as may be caused by non-uniform carburisation to due to methane dissociation, are precluded.
[0135] The CO content is not constant during treatment because natural gas is added to compensate for the effects of carburising. Accordingly a CO analyser is needed to enable adjustment. If the CO content falls below a minimum value, the option still remains to increase the CO content again with a brief flushing phase. In the course of the process, the concentrations of CO and H 2 initially fall and rise during the over-carburisation phase, because until this time a relatively large quantity of CH 4 has been needed initially to saturate the surface of the parts being treated.
[0136] In the process sequence according to the invention, this behaviour is advantageously such that less enrichment is required. During the diffusion phase, in which the need for enrichment gas is the smallest, the concentrations are thus approximately equivalent to the normal reaction compound.
[0137] Accordingly, a practically self-regulating, adaptive gasification system has been created in which natural gas is only added as an enrichment agent when the C potential of the atmosphere falls because of carburisation of the parts, and not due to flushing losses or such other causes.
[0138] The circular process for making significant economies in process gas, as represented by the ideal objective illustrated in FIG. 2 , is fulfilled with the invention.
[0139] The external module associated with the performance of the method, and which is to be used preferably, essentially includes the following in a housing:
a) a closable preparation chamber with a catalyst and temperature adjustment device for preparing the process gases, which is via one detachable and sealable inflow line for a prepared process gas to be introduced into the treatment chamber of the industrial furnace and one sealable outflow line for a treatment medium from an area or from the treatment chamber of the industrial furnace, b) a blower-type compressor with drive unit attached to the preparation chamber and functionally integrated with the inflow line, c) equipment for measuring the inflow of treatment media of the process gas, the pressure in the treatment chamber, the rotating speed of the compressor and the temperature of the catalysts, which equipment is connected functionally to the treatment chamber of the industrial furnace, the preparation chamber and the compressor, and d) an assigned switching unit for controlling and adjusting parameters such as the pressure, temperature, the volume flow of the process gas to be prepared in the preparation chamber for the purpose of feeding the treatment media, feeding the prepared process gas into the treatment chamber of the industrial furnace, and the C level.
[0144] From the point of view of someone skilled in this field, these reactions are to be understood such that of course air and the cited hydrocarbon gas may also be used to adjust the carbon potential. This means that at quantity of air is introduced if the C potential is to be lowered; on the other hand, a hydrocarbon gas is introduced if it is desired to raise the C level.
[0145] The fundamentally new gas preparation process corresponding to the preliminary stage of the invention was already defined in the DE 10 2008 029 B1 cited at the outset. This process involves reducing the gas components CO 2 and H 2 O to CO and H 2 in a preparation chamber not separately arranged there by means of unburned gases fed into the preparation chamber, which essentially consist of hydrocarbons, if necessary with certain percentages of an oxidizing gas, such as O 2 , CO 2 , etc.
[0146] To this end, the gas to be prepared and the unburned gases must be heated to a reaction temperature necessary for the conversion, and a metal catalyst must be present to accelerate the process. Depending on the metal of the used catalyst, the necessary conversion temperatures range from 800° C. to 1250°.
[0147] Since no prepared reaction gas is often available at the start of the process in heat treatment furnaces operated with reaction gases, it must first be generated for the respective location.
[0148] In an especially advantageous embodiment of the preparation chamber, the latter can also be used to generate the reaction gas required by the heat treatment furnace.
[0149] In this reaction gas generating process, the preparation chamber is operated similarly to an endothermic atmosphere generating system (like an endothermic gas generator), specifically in such a way as to entirely or partially prevent the supply of gas from the treatment chamber into the preparation chamber (by stopping or decelerating the circulating fan or closing the corresponding line valve), raise the quantities of hydrocarbons and oxidizing gases metered in the preparation chamber based on the required amount of endothermic gas to be generated, and analyse and regulate the quality of the generated endothermic reaction gas, relaying the endothermic gas generated in this way to the furnace in a hot or cooled state.
[0150] After the treatment chamber of the furnace according to the invention has been scoured for the corresponding requisite period of time with the endothermic reaction gas generated in the preparation chamber, the furnace is ready for thermochemical heat treatment, and the preparation chamber can be switched from the gas generating process to the gas preparation process.
[0151] In an especially advantageous way, this enables the configuration and combined utilization of the preparation chamber for the gas generation and gas preparation of reaction gases.
[0152] In order to satisfy these requirements, the preparation chamber is designed to be fire-resistant and gastight, and provided with a heater and temperature controller.
[0153] In order to accelerate the gas reactions described above, metals known from the gas generating systems, in particular nickel, are used as the catalyst material.
[0154] The performance of the preparation chamber with respect to quantity and quality of preparation or of the generated reaction gas depends on the reaction temperature level, in particular on the size of the catalyst surface. Catalysts of the kind used for scrubbing the exhaust gas in passenger car engines yield catalysts that perform at an especially high level, while at the same time exhibiting a compact structure.
[0155] The overall scope of the invention may be represented in this context by a detailed explanation of its optional variants:
[0156] The key to the method for preparing process gases for heat treatments of metallic materials/workpieces in industrial furnace treatment chambers is that the respective process gas is able to be prepared at temperatures that are independent of the temperature in the treatment chamber, in a process separate from the heat treatment process in the treatment chamber, and in a temperature range significantly lower than the temperatures in the heating chamber, up to a temperature of about 1250° C.
[0157] The process gas is usually a process gas that is consumed after the heat treatment process or thermochemical treatment, and it is prepared in the separate process.
[0158] Process gases are enriched and generated separately in a preparation step according to at least one of the following reaction equations, for example,
[0000] 2CH 4 +O 2 2CO+4H 2
[0000] CH 4 +CO 2 2CO+2H 2
[0000] CH 4 +H 2 O CO+3H 2
[0000] or an equation having equivalent effect.
[0159] After a carburising or heat treatment process step according to one of the following reaction equations, for example,
[0000] 2CO→C+CO 2
[0000] CO+H 2 →C+H 2 O
[0000] CO→C+0.5O 2
[0000] or an equation having equivalent effect, the used process gas is returned to the treatment chamber.
[0160] The sequence of the preparation step and the process steps of heat treatment, thermochemical treatment or carburisation is carried out in a closed circuit via the preparation step and in a preparation chamber having a catalyst and temperature adjustment device that is separate from the treatment chamber of the industrial furnace.
[0161] For this, a module may be used that includes the preparation chamber with the catalyst and temperature adjustment device, wherein an external module is particularly advantageous for industrial furnaces that need to be retrofitted.
[0162] On the other hand, a module that is integrated in the industrial furnace may also be used, particularly for new installations. The module may be connected to the treatment chamber via lines.
[0163] The used process gas may be extracted from the treatment chamber and returned to the preparation chamber via an outflow line, and the prepared process gas may be compressed and fed into the treatment chamber from the preparation chamber via an inflow line.
[0164] At least one process gas compressor is used to accelerate the closed circuit of extracting the used process gas and feeding the prepared process gas back, and to at least homogenise and compress it, and transport it with a higher level of activation. At least one process gas compressor is functionally integrated in the preparation step, and a turbocharger may be used as the process gas compressor. A piston compressor may be used as the process gas compressor.
[0165] In this way, the preparation of process gases for heat treatments of metallic materials/workpieces in industrial furnace treatment chambers, which process gas includes at least
a first treatment medium as a protective gas, which may include the components carbon dioxide, oxygen and steam in addition to the components carbon monoxide, hydrogen and nitrogen, and a second treatment medium as a reagent gas, which initiates a thermochemical process,
may proceed as follows:
a) In the preparation step, the process gas is prepared with respect to at least one of the properties thereof that are essential for heat treatment, such as chemical properties, temperatures, pressures or flow speeds, in a separate module outside of the treatment chamber and the industrial furnace, and in this step b) the components, such as carbon dioxide, oxygen and steam react catalytically with a hydrocarbon as a reagent gas to yield carbon monoxide and hydrogen, and after this reaction the protective gas has an adjusted C potential, wherein c) the C potential is adjusted with respect to at least one of the parameters such as temperature, pressure and flow speed depending on the conditions in the treatment chamber and the prepared process gas, having been compressed, homogenised and accelerated is fed into the treatment chamber via the process gas compressor and directed and controlled with respect to the materials/workpieces via a single-point or multipoint feed system, and d) in the treatment chamber at least one treatment medium of the process gas is recirculated and recovered for preparation in the separate module.
[0172] Air from a cold area may be added to the treatment media of the process gas being prepared.
[0173] The used process gas or at least one of its treatment media is extracted from the treatment chamber and fed back into the treatment chamber after it has been prepared.
[0174] At least one process gas compressor is used for the flow accelerating and compressing circulation of at least one treatment medium of the process gas being prepared, with which air from a cold area may be mixed for cooling. The process gas compressor may be driven by a blower.
[0175] The compressing, mixing/homogenising and/or accelerating transport of the process gas is directed towards the materials/workpieces of the batch to be treated via the single-point or multipoint feed system, which may be adapted to the treatment chamber of the respective furnace type. Flow optimising guidance devices are able to assist the directed transport of the process gas towards the workpieces/materials.
[0176] It is conceivable for the process gas or at least one of the treatment media to be diverted from at least one other industrial furnace or treatment chamber.
[0177] In order to control and adjust as well as monitor the process atmosphere in the treatment chamber of the industrial furnace or the temperature of the process gas, equipment having at least one of the requisite elements such as probes, analysers and sensors is used to measure the temperature and CO content as well as the pressure in the treatment chamber and at least one further parameter, such as the oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere in the treatment chamber, and subsequently to regulate the preparation of the process gas in the preparation chamber and to control the inflow or outflow thereof according to the reconditioning time for at least one treatment medium from the treatment chamber.
[0178] The reconditioning time may be controlled according to at least one of the parameters such as
a) rotating speed of the compressor and b) number of times the process gas passes through the preparation chamber with the catalyst without interruption.
[0181] Software may be used for controlling and adjusting by segments at least one treatment medium of the process gas to be prepared for the atmosphere in the treatment chamber by at least a pulsed, timed or constant addition of at least one of the treatment media as reagent gases.
[0182] At least one treatment medium of the process gas may be used for several industrial furnaces or treatment chambers.
[0183] Partial mass flows of the process gas may be produced and controlled in at least one process step.
[0184] In order to carry out the method, the device includes a closable preparation chamber equipped with a catalyst and temperature adjustment device for preparing the process gases, the functionally integrated process gas compressor, equipment functionally connected to the treatment chamber of the industrial furnace, the preparation chamber and the process gas compressor for measuring the inflow of the process gas treatment media, and a switching unit for controlling and adjusting at least one of the parameters of the process gas being prepared in the preparation chamber for the purpose of feeding treatment media, feeding the prepared process gas into the industrial furnace treatment chamber, and the C level, and for extracting at least one of the treatment media.
[0185] The device may be configured as a separate module including
a) a housing with the closable preparation chamber, the catalyst and the temperature adjustment device, which housing is equipped with at least one detachable and sealable inflow line each for the prepared process gas or components thereof as treatment media to be introduced into the industrial furnace treatment chamber, and one outflow line for at least one treatment medium from an area of from the treatment chamber of the industrial furnace, b) equipment for measuring the inflow of the process gas treatment media, the pressure in the treatment chamber, the rotating speed of the process gas compressor, the actuation of elements such as valves in order to create a partial mass flow of the process gas, and the temperature of the catalyst, and c) the switching unit for controlling and adjusting the parameters such as pressure, temperature, volume flow of the process gas to be prepared in the preparation chamber,
wherein the process gas compressor may be attached to the treatment chamber.
[0189] It is preferably also possible to attach the process gas compressor to the preparation chamber.
[0190] It is conceivable for the module to be configured as a separate module integrated in the industrial furnace, and in this case the module may also be designed functionally as a retort.
[0191] Preferably for retrofits according to the invention, it is designed as separate module that may be connected externally to an existing industrial furnace.
[0192] The respective module may be lined with a ceramic material.
[0193] The equipment is equipped in detail with at least one of the following elements:
d) probes, analysers and sensors for measuring a temperature, a CO content and a pressure in the treatment chamber, and at least one more of the parameters such as oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere in the treatment chamber, e) a switching unit ( 2 . 5 ) as a control and adjustment device for preparing the process gas ( 3 ) in preparation chamber ( 2 . 2 ), and controlling the inflow or outflow according to the reconditioning time, and f) means for controlling a residence time, cycles or a partial mass flow of the process gas ( 3 ) in preparation chamber ( 2 . 2 ) or treatment chamber ( 1 . 1 ).
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0197] In the drawing:
[0198] FIG. 1 is a diagrammatic representation of a carburisation reaction on the surface of a part and secondary reactions in the furnace atmosphere according to the described prior art,
[0199] FIG. 2 is a diagrammatic representation of the reactions known previously in principle in a treatment and preparation chamber designed in accordance with DE 10 2008 029 001.7-45 including recirculation of the prepared gas, and
[0200] FIG. 3 is a diagrammatic representation of an example of an industrial furnace operated according to the method and using the device according to the invention for preparing process gases.
DETAILED DESCRIPTION OF THE INVENTION
[0201] FIG. 3 is a diagrammatic representation of a plant designed according to the invention including for example an industrial furnace 1 that is suitable for retrofitting. Industrial furnace 1 has a treatment chamber 1 . 1 , a multipoint feeder as a multipoint feed system 1 . 2 , and a quenching area 1 . 3 .
[0202] Even though a single-point feed is essentially possible, the advantages offered by a multi-point feed 1 . 2 for siphoning the reaction gas to be prepared from the treatment chamber 1 . 1 and returning the gas prepared in the preparation chamber 2 . 2 to the treatment chamber 1 . 1 are here to be realized by using an interface in the form of a coaxial dual-pipe with an inner pipe that is somewhat longer than the outer pipe, and by siphoning the reaction gas to be prepared via the inner pipe, and returning the prepared gas via the outer pipe.
[0203] A treatment chamber circulation system 1 . 4 is arranged above treatment chamber 1 . 1 .
[0204] An inflow line 1 . 5 for a process gas 3 enters treatment chamber 1 . 1 , and an outflow line 1 . 6 for extracting at least a first treatment medium 3 . 1 of process gas 3 exits treatment chamber 1 . 1 .
[0205] An external module 2 consists of a housing 2 . 1 with a preparation chamber 2 . 2 , which is equipped with a catalyst 2 . 2 . 1 and a temperature adjustment device 2 . 2 . 2 . Preparation chamber 2 . 2 is connected to treatment chamber 1 . 1 via inflow line 1 . 5 for the process gas 3 . A process gas compressor 2 . 3 , which may be in the form of a turbocharger for example, is arranged before preparation chamber 2 . 2 in outflow line 1 . 6 —primarily in order to extract a first treatment medium 3 . 1 of process gas 3 from treatment chamber 1 . 1 more quickly. Process gas compressor 2 . 3 also ensures that process gas 3 is highly compressed during preparation in preparation chamber 2 . 2 , and that the prepared process gas 3 is forwarded to treatment chamber 1 . 1 in a highly compressed state.
[0206] In addition, the preparation chamber 2 . 2 can be designed to be fire-resistant and gastight, and provided with a second heater and temperature controller.
[0207] In order to accelerate the gas reactions, metals, in particular nickel, are used as the material for the catalyst 2 . 2 . 1 , wherein the use of the catalyst 2 . 2 . 1 has been proven effective for scrubbing the exhaust gas in passenger car engines.
[0208] In order to prevent a reactive breakdown of the introduced process gas 3 after it exits the treatment chamber 1 . 1 or exits the preparation chamber 2 . 2 , the method can be expanded so as to cool this process gas 3 .
[0209] To this end, a cooling aggregate 1 . 7 , preferably one designed as a ribbed pipe piece with ducted or induced cooling, is allocated to at least inflow line 1 . 5 or outflow line 1 . 6 .
[0210] As an alternative, a reactive breakdown of the introduced process gas 3 can be avoided by heat-insulating or heating the latter after it exits the treatment chamber 1 . 1 or exits the preparation chamber 2 . 2 , so that it achieves its gas temperature.
[0211] In the above alternative case, insulation or a first heater would have to be allocated to at least inflow line 1 . 5 or outflow line 1 . 6 .
[0212] Equipment 2 . 4 for measuring the supply of treatment media 3 . 1 , 3 . 2 of process gas 3 , the pressure in treatment chamber 1 . 1 , the rotating speed of the process gas compressor 2 . 3 , and the temperature of catalyst 2 . 2 . 1 is connected to treatment chamber 1 . 1 and to a switching unit 2 . 5 for controlling and adjusting the parameters such as pressure, temperature, the volume flow of the process gas 3 to be prepared in preparation chamber 2 . 2 . for the purpose of introducing treatment media 3 . 1 , 3 . 2 and air 3 . 3 , introducing the prepared process gas 3 into treatment chamber 1 . 1 of industrial furnace 1 and the C level, and extracting at least one of treatment media 3 . 1 , 3 . 2 .
[0213] The expanded equipment 2 . 4 for an input/output monitoring system designed as a control loop encompasses (not to be shown)
Gas composition analysers, in particular for gas components CO and CH 4 , but also CO 2 and H 2 , and potentially H 2 O and/or O 2 , Sensors for determining the quantity and temperature of the gas flowing into the preparation chamber 2 . 2 for preparation and flowing out of the preparation chamber 2 . 2 after prepared, Controllable metering valves and rate meters for the unburned gases fed into the preparation chamber 2 . 2 , and A programmable control system for processing the measuring data, calculating the target variables, and relaying the control signals to the actuators, such as valves.
[0218] With this system, the method according to the invention for preparing the respective process gas 3 at temperatures up to about 1250° C. that are uncoupled from the temperature in treatment chamber 1 . 1 , is enriched and generated in a preparation step, in this example according to a reaction equation
[0000] 2CH 4 +O 2 2CO+4H 2
[0000] CH 4 +CO 2 2CO+2H 2
[0000] CH 4 +H 2 O CO+3H 2
[0000] and the used process gas 3 is returned to treatment chamber 1 . 1 after a carburisation process step (see FIGS. 1 and 2 ), in this example according to a reaction equation
[0000] 2CO→C+CO 2
[0000] CO+H 2 →C+H 2 O
[0000] CO→C+0.5O 2
[0219] In this context, it should be noted again it is within the scope of the central idea of the invention that other reactions may also take place according to the composition of the gas components and depending on the corresponding heat treatment methods for preparing the process gas 3 and its consumption as part of the treatment.
[0220] The sequence of the preparation step and the process step—as here of the carburisation—takes place in a recirculating circuit. The preparation step is carried out in preparation chamber 2 . 2 which is equipped with catalyst 2 . 2 . 1 and temperature adjustment device 2 . 2 . 2 and separate from industrial furnace 1 but connected to treatment chamber 1 . 1 via lines 1 . 5 , 1 . 6 .
[0221] The entire recirculation process also encompasses the generation of the reaction gas to be prepared as a process gas 3 in preparation chamber 2 . 2 .
[0222] The following steps are required for this purpose:
a) Using the preparation chamber 2 . 2 as a type of endothermic gas generating system, in such a way as to entirely or partially prevent the supply of gas from the treatment chamber 1 . 1 into the preparation chamber 2 . 2 , b) Raising the quantities of hydrocarbons and oxidizing gases metered in the preparation chamber 2 . 2 based on the required amount of endothermic gas to be generated, and analysing and regulating the quality of the generated endothermic reaction gas, and c) Relaying this generated process gas 3 as a quasi-endothermic gas to the treatment chamber 1 . 1 in a hot or cooled state.
[0226] After the treatment chamber 1 . 1 has been scoured with the endothermic reaction gas generated in this way in the preparation chamber 2 . 2 , preparations for a thermochemical heat treatment are complete, and the preparation chamber 2 . 2 for the gas generating process is switched over to the actual preparation process.
[0227] The used process gas 3 is accelerated out of treatment chamber 1 . 1 through outflow line 1 . 6 exiting treatment chamber 1 . 1 and to preparation chamber 2 . 2 by accelerating process gas compressor 2 . 3 , and after it has been prepared it is returned as prepared and highly compressed process gas 3 out of preparation chamber 2 . 2 through infeed line 1 . 5 to treatment chamber 1 . 1 . This sequence is supported by process gas compressor 2 . 3 significantly with respect to the improved effects according to the invention of
gas reactions for generating carburising gas components in the atmosphere, convective gas phase homogenisation for the transport of carbon-containing molecules in the gas phase and to the part, transport by diffusion of carbon-containing molecules through the flow boundary layer to the surface of the part, dissociation and adsorption in terms of splitting of molecules on the surface of the part, absorption of the carbon by the surface of the part, and diffusion of the carbon into the part.
[0234] The unburned gases being fed into the preparation chamber 2 . 2 , such as natural gas and air, along with other hydrocarbons and other oxidizing gases, can be adjusted relative to a supplied overall quantity and the ratio of supplied individual quantities, based on the quantity and composition of the gas to be prepared and the desired preparation result.
[0235] The composition, flowing quantity and temperature are here measured for the process gas 3 to be prepared after exits the treatment chamber 1 . 1 and before it enters the preparation chamber 2 . 2 , as well as for the prepared gas after it exits the preparation chamber 2 . 2 and before it enters the treatment chamber 1 . 1 .
[0236] The entire quantity of the unburned gases fed into the preparation chamber 2 . 2 along with the relative quantities of individual unburned gas components are continuously varied relative to each other in such a way as to yield a process-optimised preparation result.
[0237] This sequence forms a closed control loop, in which target variables for the prepared gas are defined based on an analysis of the gas to be prepared, in particular with respect to CO content and CH 4 content, and potentially also with respect to H2 content and CO 2 or H 2 O content. Attainment of target variables is ensured by varying the quantities of individual unburned gas components fed to the preparation chamber 2 . 2 , and monitored and readjusted as needed by analysing the prepared process gas 3 .
[0238] For the preparation of process gases 3 , this includes at least
first treatment medium 3 . 1 as the protective gas, which includes components carbon dioxide, oxygen and steam in addition to minimum components carbon monoxide, hydrogen, and nitrogen, and second treatment medium 3 . 2 as the reagent gas, which initiates the carburising process.
[0241] The processes may be summarised as follows:
process gas 3 is accordingly prepared in the preparation step with regard to at least one of the properties thereof that are essential for the heat treatment, such as chemical properties, temperatures, pressures, or flow speeds, separately in external module 2 , outside of treatment chamber 1 . 1 and industrial furnace 1 , in this context, the components such as carbon dioxide, oxygen, and steam react catalytically with a hydrocarbon as a reagent gas to yield carbon monoxide and hydrogen, and following this reaction the protective gas will have an adjusted C potential, the C potential is adjusted according to at least one of the parameters, such as temperature, pressure, and flow speed depending on the conditions in treatment chamber 1 . 1 and having been compressed, homogenised and accelerated the prepared process gas 3 is fed in controlled manner back to treatment chamber 1 . 1 with the aid of process gas compressor 2 . 3 and directed towards the materials/workpieces via, in this case, multipoint feed system 1 . 2 , and at least one treatment medium 3 . 1 , 3 . 2 of process gas 3 is recirculated in treatment chamber 1 . 1 and recovered for preparation in external module 2 .
[0246] If necessary, air 3 . 3 from a cold area may be added to treatment media 3 . 1 , 3 . 2 of the process gas 3 to be prepared.
[0247] The used process gas 3 or at least one of the treatment media 3 . 1 , 3 . 2 thereof is extracted from treatment chamber 1 . 1 by suction and then returned to treatment chamber 1 . 1 after it is has been prepared.
[0248] If necessary, several process gas compressors 2 . 3 may be used for flow-accelerating and compressing circulation of at least one treatment medium 3 . 1 , 3 . 2 of the process gas 3 to be prepared, and air 3 . 3 is also supplied to these from the cold area for cooling purposes.
[0249] Process gas compressor 2 . 3 may be driven by a blower, but this is not shown in the figure.
[0250] In general, it is advantageous if the compressing, mixing/homogenising and/or accelerating transport of the process gas 3 is directed at the materials/workpieces of the batch that are to be treated via multipoint feed/multiple point feeder system 1 . 2 , which may also be adapted to the treatment chamber 1 . 1 of the respective furnace type.
[0251] The prepared process gas 3 may be directed at the workpieces/materials economically via flow optimising guidance devices, but these are not illustrated in the figure.
[0252] The method is used advantageously in furnace lines, for example, which are not shown here, if the process gas 3 or at least one of the treatment media 3 . 1 , 3 . 2 is diverted from at least a second industrial furnace 1 .
[0253] In order to control and adjust as well as monitor the process atmosphere in treatment chamber 1 . 1 of industrial furnace 1 or the temperature of the process gas 3 , equipment 2 . 4 having at least one of the requisite elements such as probes, analysers and sensors is used to measure the temperature and CO content as well as the pressure in treatment chamber 1 . 1 and at least one more of the parameters, such as the oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere in treatment chamber 1 . 1 , and subsequently to regulate the preparation of the process gas 3 in preparation chamber 2 . 2 and to control the inflow into treatment chamber 1 . 1 or outflow of at least one treatment medium 3 . 1 , 3 . 2 from treatment chamber 1 . 1 .
[0254] Software is used purposefully for control and adjustment of at least one treatment medium 3 . 1 , 3 . 2 of the process gas 3 to be prepared for the atmosphere in treatment chamber 1 . 1 , and it controls or adjusts the pulsed, timed, and/or constant feeing of at least one of the treatment medium 3 . 1 , 3 . 2 , for example the reagent gases, by segments.
[0255] The method is capable of being expanded, for example in furnace lines, such that at least one treatment medium 1 , 3 . 2 of the process gas 3 is use for multiple industrial furnaces 1 or treatment chambers 1 . 1 .
[0256] It is particularly advantageous if the process of controlling and adjusting as well as monitoring the process atmosphere in treatment chamber 1 . 1 of industrial furnace 1 or the temperature of the process gas 3 , is assured by equipment 2 . 4 having at least one of the requisite elements such as probes, analysers and sensors, which measure the temperature and CO content as well as the pressure in treatment chamber 1 . 1 and at least one more of the parameters, such as the oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere in treatment chamber 1 . 1 , and subsequently regulates the preparation of the process gas 3 in preparation chamber 2 . 2 and controls the inflow or outflow thereof according to the reconditioning time for at least one treatment medium 3 . 1 , 3 . 2 from treatment chamber 1 . 1 .
[0257] In this context, the reconditioning time is controlled according to at least one of the parameters such as
a) rotating speed of the compressor and b) number of times the process gas 3 passes through preparation chamber 2 . 1 with catalyst 2 . 2 without interruption.
[0260] Accordingly, the device for carrying out the method as has already been described above with an external module 2 includes
a) the closable preparation chamber 2 . 2 with catalyst 2 . 2 . 1 and temperature adjustment device 2 . 2 . 2 for preparing the process gases 3 , which is via one detachable and sealable inflow line 1 . 5 for the prepared process gas 3 or components thereof such as treatment media 3 . 1 , 3 . 2 to be introduced into treatment chamber 1 . 1 of industrial furnace 1 , and outflow line 1 . 6 for at least one treatment medium 3 . 1 , 3 . 2 from an area or from the treatment chamber 1 . 1 of industrial furnace 1 , b) the blower-type compressor 2 . 3 with drive unit attached to and functionally integrated with preparation chamber 2 . 2 , and c) equipment 2 . 4 for measuring the inflow of treatment media 3 . 1 , 3 . 2 of the process gas 3 , the pressure in treatment chamber 1 . 1 , the rotating speed of process gas compressor 2 . 3 , and the temperature of catalyst 2 . 2 . 1 , which equipment is connected functionally to treatment chamber 1 . 1 of the industrial furnace, preparation chamber 2 . 2 , and process gas compressor 2 . 3 , d) switching unit 2 . 5 for controlling and adjusting parameters such as pressure, temperature, volume flow of the process gas to be prepared in preparation chamber 2 . 2 for the purpose of feeding treatment media 3 . 1 , 3 . 2 , feeding the prepared process gas 3 into treatment chamber 1 . 1 of industrial furnace 1 , and the C level, as well as extracting at least one of the treatment media 3 . 1 , 3 . 2 .
[0265] In this example, external module 2 is constructed as a housing with closable preparation chamber 2 . 2 , catalyst 2 . 2 . 1 , and temperature adjustment device 2 . 2 . 2 . Housing 2 has at least one detachable and sealable infeed line 1 . 5 each for the prepared process gas 3 or the components thereof, such as treatment media 3 . 1 , 3 . 2 , to be introduced into treatment chamber 1 . 1 of industrial furnace 1 , and one outflow line 1 . 6 for at least one treatment medium 3 . 1 , 3 . 2 from treatment chamber 1 . 1 of the industrial furnace or an area thereof.
[0266] Equipment 2 . 4 is to be designed for measuring the inflow of treatment media 3 . 1 , 3 . 2 of the process gas 3 , the pressure in treatment chamber 1 . 1 , the rotating speed of process gas compressor 1 . 4 , 2 . 3 and for actuating elements such as valve to create a partial mass flow of the process gas 3 , and the temperature of catalyst 2 . 2 . 1 .
[0267] Switching unit 2 . 5 must be provided for controlling and adjusting parameters such as pressure, temperature, volume flow of the process gas 3 to be prepared in preparation chamber 2 . 2 .
[0268] A turbocharger may be used as the process gas compressor 1 . 4 attached to treatment chamber 1 . 1 .
[0269] For special new constructions, separate module 2 may be designed as a module integrated in industrial furnace 1 , though this is not shown here, and such a configuration as a retort is conceivable.
[0270] In the example presented here, a preferred illustration of separate module 2 is represented as a module that may be connected to industrial furnace 1 externally.
[0271] For module 2 a lining with a ceramic material may be used, such as is known from the prior art described in the introduction.
[0272] Finally, the device includes the equipment 2 . 4 indicated previously, having at least one of the following elements:
a) probes, analysers and sensors for measuring a temperature, a CO content and a pressure in treatment chamber 1 . 1 , and at least one more of the parameters such as oxygen partial pressure, CO 2 content, and dewpoint of the atmosphere in treatment chamber 1 . 1 , b) switching unit ( 2 . 5 ) as a control and adjustment device for preparing the process gas 3 in preparation chamber 2 . 2 , and controlling inflow or outflow according to the reconditioning time, and c) means for controlling a residence time, cycles or a partial mass flow of the process gas 3 in preparation chamber 2 . 2 or treatment chamber 1 . 1 .
LEGEND
[0000]
1 =Industrial furnace
1 . 1 =Treatment chamber
1 . 2 =Multipoint feed
1 . 3 =Quenching area
1 . 4 =Treatment chamber circulating system
1 . 5 =Inflow
1 . 6 =Outflow
1 . 7 =Cooling aggregate
2 =Module
2 . 1 =Housing
2 . 2 =Preparation chamber
2 . 2 . 1 =Catalyst 2 . 2 . 2 =Temperature control device
2 . 3 =Process gas compressor
2 . 4 =Equipment
2 . 5 =Switching unit for control and adjustment
3 =Process gas
3 . 1 =First treatment medium
3 . 2 =Second treatment medium
3 . 3 =Air
|
In a method and with a device for preparing process gases ( 3 ) for heat treatments of metallic materials/workpieces, the respective process gas ( 3 ) is to be fed into at least one treatment chamber ( 1.1 ) in an industrial furnace ( 1 ) having been practically fully prepared, homogenised and heated, and the method is to be carried out both with newly built and particularly with already existing installations of industrial furnaces ( 1 ) with the aid of the device, wherein the process gas ( 3 ) is prepared with compression at temperatures uncoupled from the temperature in the treatment chamber ( 1.1 ), in a process separate from the heat treatment process in the treatment chamber ( 1.1 ), and in a temperature range up to about 1250° C., and is rendered usable for economical and low-emission heat treatment (FIG. 3 ).
| 8
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a pulse combustion apparatus in which pulsating explosive combustions occur repeatedly and continuously. A pulse combustion apparatus performs repeatedly explosive combustions in a certain cycle by making use of self-ignition and natural suction of air for combustion at the time or regular combustion, at which combustion heat is used to be applied for cooking devices and the like.
2. Description of the Prior Art
One example of a combustion chamber of this pulse combustion apparatus is shown in FIG. 2. A combustion chamber R in which explosive combustions are performed is generally formed and sectioned by a wall W having a curved face of a snail or a cylindrical shape or the like with a fundamental curvature owing to the characterization of pulse combustion and so on. And as an ignition device necessary at the start of combustion, an ignition plug P is set and inserted into the curved wall W spirally by the screw part P1. Also, TP in FIG. 2 is a tail pipe for the discharge of combustion exhaust.
SUMMARY OF THE INVENTION
As the temperature inside the combustion chamber R of such pulse combustion apparatus becomes, however, very high, the top (L letter-shape part shown by the broken line) of the ground electrode P2 on the ignition plug P often burns or is damaged as shown in FIG. 2. Also the central electrode P3 expands due to high temperature and oxidization, and the surrounding insulator P4 may break up to cut the wire inside.
An object of the present invention is to provide an apparatus in which the above problem may be resolved and to extend the life span of the ignition plug by more efficient radiation of heat from the ignition plug to the outside through the combustion chamber.
This invention is thus summarized as a combustion chamber of pulse combustion apparatus which is formed by a curved faced wall into which is set an ignition plug whose sparks start pulsating explosive combustions in the combustion chamber, and that, in the combustion chamber, the inner face of the wall section where the ignition plug is set and inserted into is furthermore formed with respect to the continuous curved face with a fundamental curvature, to a nearly flat face almost perpendicular to the axis of the ignition plug by increasing the wall thickness inwardly of the chamber.
In the combustion chamber of the pulse combustion apparatus according to the above structure of this invention, the heat of ignition plug heated up during combustion is well radiated by equal transmission through its wall, because the inner face of the wall where the ignition plug is set and inserted is formed to a nearly flat face almost perpendicular to the axis of the ignition plug. In the prior apparatus, an ignition plug is set and inserted generally slantwise to the wall face and furthermore due to the curved face the contact area between the ignition plug and the receiving wall is not constant around its plug. That is, as shown by letter A in FIG. 2, the plug is to have partially an exposed part to the combustion chamber. Compared to this, in the combustion chamber of this invention constant contact with the receiving wall is achieved because the inner face of the same wall is formed approximately perpendicular to the axis of the ignition plug. As a result, radiation of heat from the ignition plug to the combustion chamber wall becomes well without partial deviation.
In order to clarify further the structure and function of this invention in the above, the combustion chamber of the pulse combustion of this invention is explained as below by way of a suitable practical example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional elevational view of a combustion chamber of the pulse combustion apparatus as a practical example of this invention; and
FIG. 2 is a sectional elevational view of a prior art arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a schematic cross-sectional diagram of a combustion chamber used in a pulse combustion apparatus as a practical example. The combustion chamber 1 is a chamber where mixed air is drawn in from a mixing chamber not shown in FIG. 1 and at a certain cycle explosive combustions are continuouly repeated, and the shape is formed like snail to possess a cave of almost circular in cross section. The entrance 2 of the combustion chamber which is connected with the mixing chamber not shown in FIG. 1, is formed toward a tangent of the combustion chamber 1 in order to take in mixed air well and also to prevent backfire.
In the wall 3 composing the combustion chamber 1, a screw hole 4 for installing an ignition plug (hereinafter called as plug fitting hole 4) is provided and into this hole a plug P is fitted and inserted by screwing. Also the inner wall face where the plug fitting hole 4 is made is formed with a flat wall perpendicular to the inserting direction of the plug P. In other words, with respect to the continuous curved face 5 forming a snail's shape, the inner wall face where the ignition plug is set is formed to be perpendicular to the axis of the ignition plug by increasing the wall thickness. This part of the inner wall face is hereinafter called an inner plane 6. Furthermore in FIG. 1 for easy understanding, hatching is placed respectively on the wall forming inner plane 6 around the plug fitting hole 4 and on the wall forming the other curved face 5. However, they are one body. Also numeral 7 in FIG. 1 indicates a tail pipe to discharge the exhausting air after combustion and which is set up in bothside faces of combustion chamber 1.
The ignition plug P in whose top is set a central electrode P3 and a ground electrode P2 bent in the form of the letter L and in whose central side face is set a cylindrical screw part P1, is fitted and inserted by screwing the screw part P1 into the plug fitting hole 4. Consequently, a ring-form face P1a of the edge of screw part P1 becomes parallel to the inner plane 6, and besides in this practical example the inserting position is set so that both of these faces are approximately in one plane. Also not shown in the drawings is a flame rod for flame detection and which is set next to the ignition plug and inserted perpendicularly on the wall forming the above inner plane 6.
In the combustion chamber 1 constructed as above, after the ignition by the ignition plug P, explosive combustions are repeated in a certain cycle and the internal temperature becomes very high. However, for the reasons mentioned below the life span of ground electrode P2 and central electrode P3 of the ignition plug can be extended. That is, as heat from the ground electrode P2 and central electrode P3 whose temperature have become high by the effect of pulse combustion is transmitted via the screw par P1 uniformly to the wall 3 of combustion chamber 1, the heat radiation effect can be increased without deviation.
In conventional device as shown in FIG. 2, the effective heat radiation can not be achieved because a part of the screw part P1 is exposed in the combustion chamber R (shown at A in FIG. 2), by the fact that the ignition plug P is inserted and set in the curved wall W. Furthermore, in this example, the inclined set up of the ignition plug also affects such partial exposure. If the exposure of screw part P1 is prevented by setting the ignition plug drawn outwards from the combustion chamber R, the position of both electrodes P2 and P3 will become far from the center of the chamber R to result in decrease of the ignition efficiency.
Compared to this, in the combustion chamber 1 of the practical example, the radiation effect of the screw part P1 can be obtained at its maximum for the face of the inner wall part where the ignition plug P is fixed by insertion is formed as perpendicular to the axis of the plug. Consequently, the breakage of ground electrode P2, the wire of central electrode P3 or others due to combustion heat can be reduced so that the life span of the ignition plug P is extended.
The temperature which reaches 900° C. at the plug top of the prior art can be reduced to 840° C. and further to 700° C. by effect of the increasing wall thickness to make the flat face 6 continuous from the fundamental curve 5 of the pulse combustion chamber.
This invention explained with the above practical example is not limited by such practical example and of course can be practiced within the limits without deviating from the major points of the invention.
|
In order to obtain good efficiency of a pulse combustion apparatus, an ignition plug is protected to extend the life span by way of discharging high heat from the plug top in good balance to the combustion chamber, in which a structure of the chamber wall is reformed with respect to the partial wall for receiving the plug screwed therein.
| 5
|
BACKGROUND OF THE INVENTION
The present invention relates to steam irons and more particularly to steam iron with controlled water flow and steam generation.
Steam irons are well known and have been in use for many years. Such irons have a handle and a base. The base includes a water reservoir, a steam chamber in fluid communication with the water reservoir, a heating element, and a base plate having a number of steam spray ports therein. Typically, the heating element heats water in the steam chamber to generate steam that may be expelled from the base plates via the steam spray ports in response to the user pressing a button. Thus, the amount of steam released from the iron depends in large part on the user. If the user presses the button for a prolonged period of time, all of the steam will be expelled from the steam chamber.
It would be advantageous to have a steam iron that can automatically control the generation and flow of steam.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description of preferred embodiments of the invention will be better understood when read in conjunction with the appended drawings. The present invention is illustrated by way of example and is not limited by the accompanying figures, in which like references indicate similar elements. It is to be understood that the drawings are not to scale and have been simplified for ease of understanding the invention.
FIG. 1 is a side, cross-sectional view of a steam iron in accordance with one embodiment of the invention; and
FIGS. 2A-2D illustrate the operation of a steam iron in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The detailed description set forth below in connection with the appended drawings is intended as a description of a presently preferred embodiment of the invention, and is not intended to represent the only form in which the present invention may be practiced. It is to be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the invention. In the drawings, like numerals are used to indicate like elements throughout.
In one embodiment, the present invention provides a steam iron including a heatable base plate having a plurality of steam outlets. A reservoir is provided for holding water and steam. A heating element is located near to the base plate and the reservoir for heating the base plate and for heating water in the reservoir and converting the water to steam. At least one steam pipe connects the base plate steam outlets with the reservoir that allows steam to move from the reservoir to the steam outlets and exit the iron. A first valve is located along the steam pipe between the reservoir and the steam outlets for regulating the flow of steam through the steam pipe. Steam may move from the reservoir to the steam outlets when the first valve is in an open position. A first actuator moves the first valve between the open position and a closed position. A sensor, coupled to the actuator, detects and measures a speed of movement of the steam iron. The actuator moves the first valve between the open and closed positions depending on the detected speed of movement.
In another embodiment, the sensor is three axis accelerometer that detects both speed and tilt angle of the steam iron and the actuator is a microcontroller that moves the valve between the open and closed positions depending on either or both of the speed of movement and the tilt angle of the steam iron. When the steam iron is moved at a predetermined speed and at a predetermined angle, steam is automatically expelled via the steam outlets.
A steam iron 10 in accordance with various embodiments of the present invention now will be described with reference to FIG. 1 . The steam iron 10 has a heatable base plate 12 having a plurality of steam spray ports or outlets 14 therein. A reservoir is provided for holding water and steam. In one embodiment of the invention, the reservoir comprises a water reservoir 16 for holding water and a steam chamber 18 for holding steam. The water reservoir 16 is in fluid communication with the steam chamber 18 . The base plate 12 , steam outlets 14 , water reservoir 16 and steam chamber 18 are all well known elements of a steam iron to those of skill in the art and a detailed description is not required for a complete understanding of the invention. Further, although the water reservoir 16 and steam chamber 18 are shown as in the drawing as separate elements at particular locations and of particular size and shape, in fact, these elements may comprise various numbers, sizes, shapes and locations, and the present invention should not be limited by such features of these elements.
The iron 10 includes a heating element for heating water in the water reservoir 16 and converting the water to steam, and heating the base plate 12 . In one embodiment of the invention, the heating element comprises at least two heating elements. A first heating element 20 is located proximate to or integral with the base plate 12 for heating the base plate 12 . A second heating element 22 is located proximate to or integral with the steam chamber 18 for converting water in the steam chamber to steam. In another embodiment of the present invention, a pre-heating element 24 is located proximate to or integral with the water reservoir 16 for pre-heating the water stored in the water reservoir 16 . Although the heating elements 20 , 22 and 24 are shown as adjacent to the base plate 12 , steam chamber 18 and water reservoir 16 , respectively, it will be understood by those of skill in the art that the heating elements may comprise various types of heating elements and be located at several different positions, such as adjacent to, near to, or integral with the base plate 12 , water reservoir 16 , and steam chamber 18 , respectively. Thus, the present invention should not be limited by the type, number, or location of the heating elements.
At least one steam pipe 26 connects the base plate steam outlets 14 with the steam chamber 18 and allows steam in the steam chamber 18 to move to the steam outlets 14 and exit or be sprayed from the iron 10 . A first valve 28 is located along the steam pipe 26 between the steam chamber 18 and the steam outlets 14 for regulating the flow of steam through the steam pipe 26 . When the first valve 28 is in an open position, steam may move from the steam chamber 18 to the steam outlets 14 , and when the first valve 28 is in a closed position, steam may not traverse the steam pipe 26 . Although only one steam pipe 26 and first valve 28 are shown, the steam iron 10 may have more than one steam pipe 26 that connects the steam chamber 18 with the steam outlets 14 .
In one embodiment of the invention, the steam iron 10 also includes a water pipe 30 connecting the water reservoir 16 with the steam chamber 18 . A second valve 32 is located along the water pipe 30 for regulating the flow of liquid between the water reservoir 16 and the steam chamber 18 . When the second valve 32 is in an open position, liquid stored in the water reservoir 16 may move to steam chamber 18 , and when the second valve 32 is in a closed position, liquid may not traverse the water pipe 30 . Although only one water pipe 30 and second valve 32 are shown, the steam iron 10 may have more than one water pipe 30 that connects the water reservoir 16 with the steam chamber 18 .
In one embodiment of the invention, the steam iron 10 includes first and second actuators for moving the first and second valves 28 and 32 , respectively, between their respective open and closed positions. In one embodiment of the invention, the first and second actuators comprise a microcontroller 34 that is electrically connected to the first and second valves 28 and 32 , and sends respective first and second actuator signals 36 and 38 to the first and second valves 28 and 32 to move the first and second valves 28 , 32 between their open and closed positions.
A sensor 40 is coupled to the microcontroller 34 for detecting and measuring a speed of movement of the steam iron 10 . The sensor 10 sends the measured speed data to the microcontroller 34 and the microcontroller 34 generates the first actuator signal 36 , to move the first valve 38 between the open and closed positions, depending on the detected speed of movement. In one embodiment of the present invention, the sensor 40 comprises an accelerometer, such as a 3-axis accelerometer that can measure both speed and tilt angle of the steam iron 10 . In such embodiment, the microcontroller 24 receives the measured speed and tilt data from the sensor 40 and generates the first and second actuator signals 36 , 38 , for moving the first and second valves 28 , 32 between their open and closed positions. The generation of steam and the flow of liquid between the water reservoir 16 , the steam chamber 18 and the base plate steam outlets 14 are thus controlled.
The sensor 40 may comprise a Micro-electromechanical system (MEMS) sensor. MEMS dual axis accelerometers are presently available in small packages, on the order of 4 mm×4 mm×1.5 mm. Such devices operate on power supplies around 3v and provide signal conditioned voltage outputs for a variety of motion sensing, tilt sensing and inertial sensing features. For example, small tilt changes can be sensed using narrow bandwidths. Example MEMS sensors that may be used to realize the present invention are Freescale Semiconductor, Inc.'s MMA7455L and MMA7456L accelerometers, which can be used for sophisticated portable electronics products.
The speed and tilt data provided by the sensor 40 to the microcontroller 34 are used as further described herein. In one embodiment, when the iron 10 moves faster than a first predetermined speed, the controller 34 generates the first actuator signal 36 to move the first valve 28 from its closed position to its open position. This would be the case for when the iron 10 is in a steam mode and a user is moving the iron 10 back and forth over an item to be ironed. The sensor 40 detects the movement speed of the iron 10 and sprays steam stored in the steam chamber 18 by way of the steam outlets 14 by causing the first valve 28 to be opened. Conversely, when the iron 10 moves slower than the first predetermined speed, the first valve 28 is moved from the open position to the closed position.
As discussed above, in addition to measuring speed of movement, the sensor 40 can also detect and measure tilt angles. Such tilt angle data is provided from the sensor 40 to the controller 34 . In turn, the controller 34 causes the first valve 28 to move between the open and closed positions depending on the detected tilt angle. In one embodiment of the invention, the first valve 28 is closed when a tilt angle of the steam iron 10 is about 90° (e.g., 90°±10°). That is, the user has placed the iron 10 in an upright or erect position, such as that shown in FIG. 2A . In another embodiment of the invention, the first valve 28 is closed when a tilt angle of the steam iron 10 is greater than about 20° (e.g., 20°±10°), as shown in FIG. 2D .
Referring now to FIGS. 2A-2D , the operation of the steam iron 10 is shown. FIG. 2A shows the steam iron 10 in an upright or erect position. The iron 10 would be in such position, for example, before or after use, or when the user is taking a break or re-positioning the item being ironed. When the iron 10 is in the upright position (i.e., the tilt angle is about 90°, as detected by the sensor 40 ), the first valve 28 is maintained in the closed position.
FIGS. 2B and 2C show the iron 10 in a flat or in-use position (i.e., the tilt angle is close to 0°, as detected by the sensor 40 ). In such case, the sensor 40 also measures the speed at which the iron is being moved, either forward or backward, and can cause steam to be sprayed out of the steam outlets 14 . That is, the tilt angle and speed data are provided from the sensor 40 to the controller 34 and the controller 34 causes the first valve 28 to be opened (or closed as the case may be).
FIG. 2D shows the steam iron 10 being lifted or moved from a relatively flat, in-use position, to an upright position. When the iron 10 is at an angle of greater than about 10°, the controller 34 causes the first valve 28 to be closed.
The iron 10 may include additional features. For example, temperature information may be passed from the heating elements 20 , 22 and 24 to the controller 34 so that optimal temperatures thereof may be maintained. Temperature sensors and their interconnection to a microcontroller are well understood by those of skill in the art. In addition, water and steam level information may be passed to the microcontroller 34 so that liquid may be moved from the water reservoir 16 to the steam chamber 18 whenever the steam chamber 18 is low on steam or needs additional steam to maintain enough pressure to eject steam out the steam ports 14 .
As is evident from the foregoing discussion, the present invention provides a steam iron with improved steam flow control. By incorporating a three-axis accelerometer, both motion and tilt angle information can be detected and provided to a controller that regulates the production and flow of steam. For example, when the iron is moved from an upright position to an in-use position, steam production may be commenced and when the iron is moved from the in-use position to the upright position, steam production may be inhibited. Additionally, steam generation and ejection can be based on the speed and direction of movement of the iron when in the in-use position. As will be understood by those of skill in the art, the first and second valves 28 and 32 may be opened and/or closed based on other factors not discussed herein, yet not required for a complete understanding of the present invention.
The description of the preferred embodiments of the present invention have been presented for purposes of illustration and description, but are not intended to be exhaustive or to limit the invention to the forms disclosed. It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but covers modifications within the spirit and scope of the present invention as defined by the appended claims.
|
A steam iron includes a sensor for detecting and measuring movement of the steam iron. The sensor is coupled to an actuator that regulates the flow of steam via a valve located between a steam chamber and steam outlets. The sensor can detect movement in three directions (X, Y, Z) and adjust steam generation based on speed of movement of the iron and tilt angle. A pre-heater is used to pre-heat water in a water chamber. The pre-heated water is provided to a steam chamber where it is later converted to steam.
| 3
|
BACKGROUND
Viscous hydrocarbon recovery is a segment of the overall hydrocarbon recovery industry that is increasingly important from the standpoint of global hydrocarbon reserves and associated product cost. In view hereof, there is increasing pressure to develop new technologies capable of producing viscous reserves economically and efficiently. Steam Assisted Gravity Drainage (SAGD) is one technology that is being used and explored with good results in some wellbore systems. Other wellbore systems however where there is a significant horizontal or near horizontal length of the wellbore system present profile challenges both for heat distribution and for production. In some cases, similar issues arise even in vertical systems.
Both inflow and outflow profiles (e.g. production and stimulation) are desired to be as uniform as possible relative to the particular borehole. This should enhance efficiency as well as avoid early water breakthrough. Breakthrough is clearly inefficient as hydrocarbon material is likely to be left in situ rather than being produced. Profiles are important in all well types but it will be understood that the more viscous the target material the greater the difficulty in maintaining a uniform profile.
Another issue in conjunction with SAGD systems is that the heat of steam injected to facilitate hydrocarbon recovery is sufficient to damage downhole components due to thermal expansion of the components. This can increase expenses to operators and reduce recovery of target fluids. Since viscous hydrocarbon reserves are likely to become only more important as other resources become depleted, configurations and methods that improve recovery of viscous hydrocarbons from earth formations will continue to be well received by the art.
SUMMARY
A SAGD system in a formation including a heated fluid injection well having a tubular including permeability control, one or more open hole anchors restricting thermal growth of the tubular and one or more baffles directing heated fluid application to target areas of the formation; and a production well in fluid collecting proximity to the injection well the production well having a tubular with permeability control, one or more open hole anchors and one or more baffles.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several figures:
FIG. 1 is a schematic view of a wellbore system in a viscous hydrocarbon reservoir;
FIG. 2 is a chart illustrating a change in fluid profile over a length of the borehole with and without permeability control; and
FIG. 3 is a perspective sectional view of a beaded matrix type permeability control device.
DETAILED DESCRIPTION
Referring to FIG. 1 , the reader will recognize a schematic illustration of a portion of a SAGD wellbore system 10 configured with a pair of boreholes 12 and 14 . Generally, borehole 12 is the steam injection borehole and borehole 14 is the hydrocarbon recovery borehole but the disclosure should not be understood as limiting the possibilities to such. The discussion herein however will address the boreholes as illustrated. Steam injected in borehole 12 heats the surrounding formation 16 thereby reducing the viscosity of the stored hydrocarbons and facilitating gravity drainage of those hydrocarbons. Horizontal or other highly deviated well structures like those depicted tend to have greater fluid movement into and to of the formation at a heel 18 of the borehole than at a toe 20 of the borehole due simply to fluid dynamics. An issue associated with this property is that the toe 20 will suffer reduced steam application from that desired while heel 18 will experience more steam application than that desired, for example. The change in the rate of fluid movement is relatively linear (declining flow) when querying the system at intervals with increasing distance from the heel 18 toward the toe 20 . The same is true for production fluid movement whereby the heel 28 of the production borehole 14 will pass more of the target hydrocarbon fluid than the toe 30 of the production borehole 14 . This is due primarily to permeability versus pressure drop along the length of the borehole 12 or 14 . The system 10 as illustrated alleviates this issue as well as others noted above.
According to the teaching herein, one or more of the boreholes (represented by just two boreholes 12 and 14 for simplicity in illustration) is configured with one or more permeability control devices 32 that are each configured differently with respect to permeability or pressure drop in flow direction in or out of the tubular. The devices 32 nearest the heel 18 or 28 will have the least permeability while permeability will increase in each device 32 sequentially toward the toe 20 and 30 . The permeability of the device 32 closest to toe 20 or 30 will be the greatest. This will tend to balance outflow of injected fluid and inflow of production fluid over the length of the borehole 12 and 14 because the natural pressure drop of the system is opposite that created by the configuration of permeability devices as described. Permeability and/or pressure drop devices 32 useable in this configuration include inflow control devices such as product family number H48688 commercially available from Baker Oil Tools, Houston Tex., beaded matrix flow control configurations such as those disclosed in U.S. Ser. No. 61/052,919, expired on May 13, 2009, U.S. Pat. No. 7,918,272 and U.S. Pat. Nos. 7,775,277, 7,789,139 and 7,784,543 the disclosures of which are incorporated herein by reference, or other similar devices. Adjustment of pressure drop across individual permeability devices is possible in accordance with the teaching hereof such that the desired permeability over the length of the borehole 12 or 14 as described herein is achievable. Referring to FIG. 2 , a chart of the flow of fluid over the length of borehole 12 is shown without permeability control and with permeability control. The representation is stark with regard to the profile improvement with permeability control.
In order to determine the appropriate amount of permeability for particular sections of the borehole 12 or 14 , one needs to determine the pressure in the formation over the length of the horizontal borehole. Formation pressure can be determined/measured in a number of known ways. Pressure at the heel of the borehole and pressure at the toe should also be determined/measured. This can be determined in known ways. Once both formation pressure and pressures at locations within the borehole have been ascertained, the change in pressure (ΔP) across the completion can be determined for each location where pressure within the completion has been or is tested. Mathematically this is expressed as ΔP location=P formation−P location where the locations may be the heel, the toe or any other point of interest.
A flow profile whether into or out of the completion is dictated by the ΔP at each location and the pressure inside the completion is dictated by the head of pressure associated with the column of fluid extending to the surface. The longer the column, the higher the pressure. It follows, then, that greater resistance to inflow will occur at the toe of the borehole than at the heel of the completion. In accordance with the teaching hereof permeability control is distributed such that pressure drop at a toe of the borehole is in the range of about 25% to less than 1% whereas pressure drop at the heel of the borehole is about 30% or more. In one embodiment the pressure drop at the heel is less than 45% and at the toe less than about 25%. Permeability control devices distributed between the heel and the toe will in some embodiments have individual pressure drop values between the percentage pressure drop at the toe and the percentage pressure drop at the heel. Moreover, in some embodiments the distribution of pressure drops among the permeability devices is linear while in other embodiments the distribution may follow a curve or may be discontinuous to promote inflow of fluid from areas of the formation having larger volumes of desirable liberatable fluid and reduced inflow of fluid from areas of the formation having smaller volumes of desirable liberatable fluid. In one embodiment, referring to FIG. 3 , the permeability control devices 110 comprise a bore disposed longitudinally through the device is of more than one diameter (or dimension if not cylindrical). This creates a shoulder 120 within the inside surface of the device 110 . While it is not necessarily required to provide the shoulder 120 , it can be useful in applications where the device is rendered temporarily impermeable and might experience differential pressure thereacross.
The matrix itself is described as “beaded” since the individual “beads” 130 are rounded though not necessarily spherical. A rounded geometry is useful primarily in avoiding clogging of the matrix 114 since there are few edges upon which debris can gain purchase.
The beads 130 themselves can be formed of many materials such as ceramic, glass, metal, etc. without departing from the scope of the disclosure. Each of the materials indicated as examples, and others, has its own properties with respect to resistance to conditions in the downhole environment and so may be selected to support the purposes to which the devices 110 will be put. The beads 130 may then be joined together (such as by sintering, for example) to form a mass (the matrix 114 ) such that interstitial spaces are formed therebetween providing the permeability thereof. In some embodiments, the beads will be coated with another material for various chemical and/or mechanical resistance reasons. One embodiment utilizes nickel as a coating material for excellent wear resistance and avoidance of clogging of the matrix 114 . Further, permeability of the matrix tends to be substantially better than a gravel or sand pack and therefore pressure drop across the matrix 114 is less than the mentioned constructions. In another embodiment, the beads are coated with a highly hydrophobic coating that works to exclude water in fluids passing through the device 110 . In addition to coatings or treatments that provide activity related to fluids flowing through the matrix 114 , other materials may be applied to the matrix 114 to render the same temporarily (or permanently if desired) impermeable.
Each or any number of the devices 110 can easily be modified to be temporarily (or permanently) impermeable by injecting a hardenable (or other property causing impermeability) substance such as a bio-polymer into the interstices of the beaded matrix 114 . Determination of the material to be used is related to temperature and length of time for undermining (dissolving, disintegrating, fluidizing, subliming, etc) of the material desired. For example, Polyethylene Oxide (PEO) is appropriate for temperatures up to about 200 degrees Fahrenheit, Polywax for temperatures up to about 180 degrees Fahrenheit; PEO/Polyvinyl Alcohol (PVA) for temperatures up to about 250 degrees Fahrenheit; Polylactic Acid (PLA) for temperatures above 250 degrees Fahrenheit; among others. These can be dissolved using acids such as Sulfamic Acid, Glucono delta lactone, Polyglycolic Acid, or simply by exposure to the downhole environment for a selected period, for example. In one embodiment, Polyvinyl Chloride (PVC) is rendered molten or at least relatively soft and injected into the interstices of the beaded matrix and allowed to cool. This can be accomplished at a manufacturing location or at another controlled location such as on the rig. It is also possible to treat the devices in the downhole environment by pumping the hardenable material into the devices in situ. This can be done selectively or collectively of the devices 110 and depending upon the material selected to reside in the interstices of the devices; it can be rendered soft enough to be pumped directly from the surface or other remote location or can be supplied via a tool run to the vicinity of the devices and having the capability of heating the material adjacent the devices. In either case, the material is then applied to the devices. In such condition, the device 110 will hold a substantial pressure differential that may exceed 10,000 PSI.
The PVC, PEO, PVA, etc. can then be removed from the matrix 114 by application of an appropriate acid or over time as selected. As the hardenable material is undermined, target fluids begin to flow through the devices 100 into a tubular in which the devices 110 are mounted. Treating of the hardenable substance may be general or selective. Selective treatment is by, for example, spot treating, which is a process known to the industry and does not require specific disclosure with respect to how it is accomplished.
Referring back to FIG. 1 , a tubing string 40 and 50 are illustrated in boreholes 12 and 14 respectively. Open hole anchors 42 , such as Baker Oil Tools WBAnchor™ may be employed in the borehole to anchor the tubing 40 . This is helpful in that the tubing 40 experiences a significant change in thermal load and hence a significant amount of thermal expansion during well operations. Unchecked, the thermal expansion can cause damage to other downhole structures or to the tubing string 40 itself thereby affecting efficiency and production of the well system. In order to overcome this problem, one or more open hole anchors 42 are used to ensure that the tubing string 40 is restrained from excessive movement. Because the total length of mobile tubing string is reduced by the interposition of open hole anchor(s) 42 , excess extension cannot occur. In one embodiment, three open hole anchors 42 , as illustrated, are employed and are spaced by about 90 to 120 ft from one another but could in some particular applications be positioned more closely and even every 30 feet (at each pipe joint). The spacing interval is also applicable to longer runs with each open hole anchor being spaced about 90-120 ft from the next. Moreover, the exact spacing amount between anchors is not limited to that noted in this illustrated embodiment but rather can be any distance that will have the desired effect of reducing thermal expansion related wellbore damage. In addition the spacing can be even or uneven as desired. The determination of distance between anchors must take into account. The anchor length, pattern, or the number of anchor points per foot in order to adjust the anchoring effect to optimize performance based on formation type and formation strength tubular dimensions and material.
Finally in one embodiment, the tubing string 40 , 50 or both is configured with one or more baffles 60 . Baffles 60 are effective in both deterring loss of steam to formation cracks such as that illustrated in FIG. 1 as numeral 62 and in causing produced fluid to migrate through the intended permeability device 32 . More specifically, and taking the functions one at a time, the injector borehole, such as 12 , is provided with one or more baffles 60 . The baffles may be of any material having the ability to withstand the temperature at which the particular steam is injected into the formation. As shown in FIG. 1 , the baffles 60 may include a substantially pointed cross-section tapered to a substantially pointed end where the pointed end is radially extended to contact the formation. In one embodiment, a metal deformable seal such as one commercially known as a z-seal and available from Baker Oil Tools, Houston Tex., may be employed. And while metal deformable seals are normally intended to create a high pressure high temperature seal against a metal casing within which the seal is deployed, for the purposes taught in this disclosure, it is not necessary for the metal deformable seal to create an actual seal. That stated however, there is also no prohibition to the creation of a seal but rather then focus is upon the ability of the configuration to direct steam flow with relatively minimal leakage. In the event that an actual seal is created with the open hole formation, the intent to minimize leakage will of course be met. In the event that a seal is not created but substantially all of the steam applied to a particular region of the wellbore is delivered to that portion of the formation then the baffle will have done its job and achieved this portion of the intent of this disclosure. With respect to production, the baffles are also of use in that the drawdown of individual portions of the well can be balanced better with the baffles so that fluids from a particular area are delivered to the borehole in that area and fluids from other areas do not migrate in the annulus to the same section of the borehole but rather will enter at their respective locations. This ensures that profile control is maintained and also that where breakthrough does occur, a particular section of the borehole can be bridged and the rest will still produce target fluid as opposed to breakthrough fluid since annular flow will be inhibited by the baffles. In one embodiment baffles are placed about 100 ft or 3 liner joints apart but as noted with respect to the open hole anchors, this distance is not fixed but may be varied to fit the particular needs of the well at issue. The distance between baffles may be even or may be uneven and in some cases the baffles will be distributed as dictated by formation condition such that for example cracks in the formation will be taken into account so that a baffle will be positioned on each side of the crack when considered along the length of the tubular.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
|
A SAGD system in a formation including a heated fluid injection well having a tubular including permeability control, one or more open hole anchors restricting thermal growth of the tubular and one or more baffles directing heated fluid application to target areas of the formation; a production well in fluid collecting proximity to the injection well the production well having a tubular with permeability control, one or more open hole anchors and one or more baffles.
| 4
|
BACKGROUND
[0001] A driveline including a continuously variable transmission allows an operator or a control system to vary a drive ratio in a stepless manner, permitting a power source to operate at its most advantageous rotational speed.
SUMMARY
[0002] Provided herein is a continuously variable transmission comprising: a first rotatable shaft operably coupleable to a source of rotational power; a second rotatable shaft aligned substantially coaxial to the first rotatable shaft, the first rotatable shaft and second rotatable shaft forming a main axis of the transmission; a third rotatable shaft aligned substantially parallel to the main axis; a variator assembly having a first traction ring assembly and a second traction ring assembly in contact with a first plurality of balls, each ball having a tillable axis of rotation; wherein the variator assembly is coaxial with the main axis, the first traction ring assembly is coupled to the second rotatable shaft; a first planetary gear set having a first sun gear, a first planet carrier, and a first ring gear; a second planetary gear set arranged coaxial with the main axis, the second planetary gear set having a second sun gear, a second planet carrier, and a second ring gear; wherein the second planet carrier is operably coupled to the first ring gear; wherein the first sun gear is coupled to the first rotatable shaft, and the first planet carrier is operably coupled to the second ring gear; a third planetary gear set arranged coaxial with the third rotatable shaft, the third planetary gear set having a third sun gear, a third planet carrier, and a third ring gear; wherein the third planet carrier is grounded; a forward clutch positioned coaxial with the third rotatable shaft, the forward clutch operably coupled to the third sun gear; and a reverse clutch operably coupled to the forward clutch and the third sun gear.
[0003] Provided herein is a vehicle driveline comprising: a power source, a variable transmission of the types disclosed herein drivingly engaged with the power source, and a vehicle output drivingly engaged with the variable transmission. In some embodiments of the vehicle driveline, the power source is drivingly engaged with the vehicle output.
[0004] Provided herein is a vehicle comprising the variable transmission of any one of the embodiments disclosed herein.
[0005] Provided herein is a method comprising providing a variable transmission of any one of the embodiments disclosed herein.
[0006] Provided herein is a method comprising providing a vehicle driveline having any one of the embodiments disclosed herein.
[0007] Provided herein is a method comprising providing a vehicle of any embodiment disclosed herein. In some embodiments, the method includes engaging the reverse clutch to operate in a reverse mode. In some embodiments, the method includes engaging the forward clutch to operate in a forward mode. In some embodiments, the method includes engaging the forward clutch and the reverse clutch to operate in a park mode. In some embodiments, the method includes disengaging the forward clutch and the reverse clutch to operate in a neutral mode.
[0008] Provided herein is a continuously variable transmission comprising: a first rotatable shaft operably coupleable to a source of rotational power; a second rotatable shaft aligned substantially coaxial to the first rotatable shaft, the first rotatable shaft and second rotatable shaft forming a main axis of the transmission; a variator assembly having a first traction ring assembly and a second traction ring assembly in contact with a first plurality of balls, each ball having a tiltable axis of rotation; wherein the variator assembly is coaxial with the main axis; a first planetary gear set having a first sun gear, a first planet carrier, and a first ring gear; a second planetary gear set arranged coaxial with the main axis, the second planetary gear set having a second sun gear, a second planet carrier, and a second ring gear; wherein the first planetary gear set is coupled to the second planetary gear set; and wherein the variator assembly is coupled to the first planetary gear set and the second planetary gear set.
INCORPORATION BY REFERENCE
[0009] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The novel features of the preferred embodiments are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present embodiments will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the preferred embodiments are utilized, and the accompanying drawings of which:
[0011] FIG. 1 is a side sectional view of a ball-type variator.
[0012] FIG. 2 is a plan view of a carrier member that is used in the variator of FIG. 1 .
[0013] FIG. 3 is an illustrative view of different tilt positions of the ball-type variator of FIG. 1 .
[0014] FIG. 4 is a schematic diagram of a planetary powersplit continuously variable transmission.
[0015] FIG. 5 is a table depicting operating modes of the continuously variable transmission depicted in FIG. 4 .
[0016] FIG. 6 is a table depicting a number of configurations of continuously variable transmissions having the ball-type variator of FIG. 1 and two planetary gear sets.
[0017] FIG. 7 is a schematic diagram of a planetary powersplit continuously variable transmission having two variators.
[0018] FIG. 8 is a table depicting operating mode of the continuously variable transmission depicted in FIG. 7 .
[0019] FIG. 9 is a schematic diagram of a powersplit continuously variable transmission having a rear wheel drive configuration.
DETAILED DESCRIPTION
[0020] The preferred embodiments will now be described with reference to the accompanying figures, wherein like numerals refer to like elements throughout. The terminology used in the descriptions below is not to be interpreted in any limited or restrictive manner simply because it is used in conjunction with detailed descriptions of certain specific embodiments. Furthermore, embodiments includes several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the embodiments described.
[0021] Provided herein are configurations of CVTs based on a ball type variators, also known as CVP, for continuously variable planetary. Basic concepts of a ball type Continuously Variable Transmissions are described in U.S. Pat. Nos. 8,469,856 and 8,870,711 incorporated herein by reference in their entirety. Such a CVT, adapted herein as described throughout this specification, comprises a number of balls (planets, spheres) 1 , depending on the application, two ring (disc) assemblies with a conical surface in contact with the balls, an input traction ring 2 , an output traction ring 3 , and an idler (sun) assembly 4 as shown on FIG. 1 . The balls are mounted on tiltable axles 5 , themselves held in a carrier (stator, cage) assembly having a first carrier member 6 operably coupled to a second carrier member 7 . The first carrier member 6 rotates with respect to the second carrier member 7 , and vice versa. In some embodiments, the first carrier member 6 is substantially fixed from rotation while the second carrier member 7 is configured to rotate with respect to the first carrier member, and vice versa. In some embodiments, the first carrier member 6 is provided with a number of radial guide slots 8 . The second carrier member 7 is provided with a number of radially offset guide slots 9 , as illustrated in FIG. 2 . The radial guide slots 8 and the radially offset guide slots 9 are adapted to guide the tiltable axles 5 . The axles 5 are adjusted to achieve a desired ratio of input speed to output speed during operation of the CVT. In some embodiments, adjustment of the axles 5 involves control of the position of the first and second carrier members to impart a tilting of the axles 5 and thereby adjusts the speed ratio of the variator. Other types of ball CVTs also exist, but are slightly different.
[0022] The working principle of such a CVP of FIG. 1 is shown on FIG. 3 . The CVP itself works with a traction fluid. The lubricant between the ball and the conical rings acts as a solid at high pressure, transferring the power from the input ring, through the balls, to the output ring. By tilting the balls' axes, the ratio is changed between input and output. When the axis is horizontal the ratio is one, illustrated in FIG. 3 , when the axis is tilted the distance between the axis and the contact point change, modifying the overall ratio. All the balls' axes are tilted at the same time with a mechanism included in the carrier and/or idler. Embodiments disclosed here are related to the control of a variator and/or a CVT using generally spherical planets each having a tiltable axis of rotation that are adjusted to achieve a desired ratio of input speed to output speed during operation. In some embodiments, adjustment of said axis of rotation involves angular misalignment of the planet axis in a first plane in order to achieve an angular adjustment of the planet axis in a second plane that is substantially perpendicular to the first plane, thereby adjusting the speed ratio of the variator. The angular misalignment in the first plane is referred to here as “skew”, “skew angle”, and/or “skew condition”. In some embodiments, a control system coordinates the use of a skew angle to generate forces between certain contacting components in the variator that will tilt the planet axis of rotation. The tilting of the planet axis of rotation adjusts the speed ratio of the variator.
[0023] For description purposes, the term “radial” is used here to indicate a direction or position that is perpendicular relative to a longitudinal axis of a transmission or variator. The term “axial” as used here refers to a direction or position along an axis that is parallel to a main or longitudinal axis of a transmission or variator. For clarity and conciseness, at times similar components labeled similarly (for example, bearing 1011 A and bearing 1011 B) will be referred to collectively by a single label (for example, bearing 1011 ).
[0024] As used here, the terms “operationally connected,” “operationally coupled”, “operationally linked”, “operably connected”, “operably coupled”, “operably linked,” “operably coupleable” and like terms, refer to a relationship (mechanical, linkage, coupling, etc.) between elements whereby operation of one element results in a corresponding, following, or simultaneous operation or actuation of a second element. It is noted that in using said terms to describe inventive embodiments, specific structures or mechanisms that link or couple the elements are typically described. However, unless otherwise specifically stated, when one of said terms is used, the term indicates that the actual linkage or coupling take a variety of forms, which in certain instances will be readily apparent to a person of ordinary skill in the relevant technology.
[0025] It should be noted that reference herein to “traction” does not exclude applications where the dominant or exclusive mode of power transfer is through “friction.” Without attempting to establish a categorical difference between traction and friction drives here, generally these are typically understood as different regimes of power transfer. Traction drives usually involve the transfer of power between two elements by shear forces in a thin fluid layer trapped between the elements. The fluids used in these applications usually exhibit traction coefficients greater than conventional mineral oils. The traction coefficient (μ) represents the maximum available traction force which would be available at the interfaces of the contacting components and is the ratio of the maximum available drive torque per contact force. Typically, friction drives generally relate to transferring power between two elements by frictional forces between the elements. For the purposes of this disclosure, it should be understood that the CVTs described here operate in both tractive and frictional applications. For example, in the embodiment where a CVT is used for a bicycle application, the CVT operates at times as a friction drive and at other times as a traction drive, depending on the torque and speed conditions present during operation.
[0026] Referring now to FIG. 4 , in some embodiments, a continuously variable transmission (CVT) 10 is provided with a first rotatable shaft 11 adapted to receive power from a source of rotational power. In some embodiments, the CVT 10 has a second rotatable shaft 12 coaxial with the first rotatable shaft 11 . The first rotatable shaft 11 and the second rotatable shaft 12 form a main axis of the CVT 10 . The CVT 10 has a variator assembly 13 arranged coaxial with the main axis. In some embodiments, the variator assembly 13 is configured to be a CVP of the type depicted in FIGS. 1-3 . In some embodiments, the variator assembly 13 has a first traction ring assembly (“CVPR1”) 14 and a second traction ring assembly (“CVPR2”) 15 in contact with an array of balls. In some embodiments, the CVT 10 is provided with a first planetary gear set 16 arranged coaxial with the main axis. The first planetary gear set 16 includes a first ring gear (“R1”) 17 , a first planet carrier (“C1”) 18 , and a first sun gear (“S1”) 19 . In some embodiments, the CVT 10 includes a second planetary gear set 20 arranged coaxial with the main axis. The second planetary gear set 20 has a second ring gear (“R2”) 21 , a second planet carrier (“C2”) 22 , and a second sun gear (“C3”) 23 . In some embodiments, the first rotatable shaft 11 is coupled to the first sun gear (“S1”) 19 . The first ring gear (“R1”) 17 is coupled to the second planet carrier (“C2”) 22 . The first planet carrier (“C1”) 18 is coupled to the second ring gear (“R2”) 21 . The second rotatable shaft 12 is coupled to the second sun gear (“S2”) 23 and the first traction ring assembly (“CVPR1”) 14 . The second ring gear (“R2”) 21 is coupled to the second traction ring assembly (“CVPR2”) 15 . The second rotatable shaft 12 is coupled to a first gear set 24 .
[0027] Still referring to FIG. 4 , in some embodiments, the CVT 10 is provided with a third rotatable shaft 25 aligned parallel to the main axis. The CVT 10 has a third planetary gear set 26 arranged coaxial with the third rotatable shaft 25 . The third planetary gear set 26 includes a third ring gear 27 , a third planet carrier 28 , and a third sun gear 29 . The third planet carrier 28 is grounded to a non-rotatable component of the CVT 10 such as the housing (not shown). In some embodiments, the CVT 10 includes a forward clutch 30 arranged coaxial with the third rotatable shaft 25 . In some embodiments, the forward clutch 30 is a synchronizer clutch. The forward clutch 30 is coupled to a second gear set 31 . The second gear set 31 is coupled to the first gear set 24 . In some embodiments, the CVT 10 includes a reverse clutch 32 . In some embodiments, the reverse clutch 32 is a synchronizer clutch. The reverse clutch 32 is coupled to a third gear set 33 (labeled in FIG. 4 as “4a”, “4b”, and “4c”). The third gear set 33 is configured to transfer power to the reverse clutch 32 from the third sun gear 29 . The CVT 10 includes a final drive gear 34 operably coupled to the third rotatable shaft 25 . The third ring gear 27 is operably coupled to the final drive gear 34 . In some embodiments, the first gear set 24 , the second gear set 31 , and the third gear set 33 have two or more meshing gears configured to transfer rotational power. It should be appreciated that in some embodiments, the first gear set 24 , the second gear set 31 , and the third gear set 33 are optionally configured to be chains driving sprockets, or belts driving pulleys. In some embodiments, the final drive ( 26 ) is optionally configured to be a gear set or chain driving another axis. In some embodiments, the third rotatable shaft 25 is configured to be coaxial with the main axis as in the case for rear wheel drive applications.
[0028] Typically, synchronizer mechanisms (referred to herein as “synchronizer clutch”) used in power transmissions include a well-known dog clutch integrated with a speed-matching device such as a cone-clutch. During operation of the transmission, if the dog teeth of the dog clutch make contact with a gear, and the two parts are spinning at different speeds, the teeth will fail to engage and a loud grinding sound will be heard as they clatter together. For this reason, a synchronizer mechanism or synchronizer clutch is used, which consists of a cone clutch. Before the teeth engage, the cone clutch engages first, which brings the two rotating elements to the same speed using friction. Until synchronization occurs, the teeth are prevented from making contact. It should be appreciated that the exact design of the synchronizer clutch is within a designer's choice for satisfying packaging and performance requirements. A synchronizer clutch is optionally configured to be a two position clutch having an engaged position and a neutral (or free) position. A synchronizer clutch is optionally configured to be a three position clutch having a first engaged position, a second engaged position, and a neutral position. Embodiments disclosed herein use synchronizer clutches to enable the pre-selection of gear sets by a control system (not shown) for smooth transition between operating modes of the transmission. It should be appreciated that other types of clutches are optionally implemented in place of synchronizer clutch to achieve the transmission configurations disclosed herein.
[0029] Referring now to FIG. 5 , during operation of the CVT 10 , a forward mode of operation corresponds to the selective engagement of the forward synchronizer clutch 30 and the disengagement of the reverse synchronizer clutch 32 . A reverse mode of operation corresponds to the selective engagement of the reverse synchronizer clutch 32 and the disengagement of the forward synchronizer clutch 30 . A neutral mode of operation corresponds to the disengagement of the forward synchronizer clutch 30 and disengagement of the reverse synchronizer clutch 32 . A park mode of operation corresponds to the simultaneous engagement of both the forward synchronizer clutch 30 and the reverse synchronizer clutch 32 .
[0030] Turning now to FIG. 6 , a number of continuously variable transmission architectures are configurable using a variator assembly, such as the variator assembly 13 , a first planetary gear set, such as the first planetary gear set 16 , and a second planetary gear set, such as the second planetary gear set 20 . For clarity and conciseness, the first planetary gear set is depicted as having the following components: a first ring gear (R1), a first planet carrier (C1), and a first sun gear (S1). The second planetary gear set is depicted as having the following components: a second ring gear (R2), a second planet carrier (C2), and a second sun gear (S2). A table 40 depicts a number of continuously variable transmission architectures listed in column 41 labeled “Configuration”. The table 40 has column 42 (“Input”) listing the planetary gear set component, or components, coupling to an input power source. An illustrative example of an input power source is embodied in the first rotatable shaft 11 . The table 40 has column 43 (“CVPR1”) listing the planetary gear set component, or components, coupling to the first traction ring assembly of the variator assembly, for example, the first traction ring assembly 14 . The table 40 has column 44 (“CVPR2”) listing the planetary gear set component, or components, coupling to the second traction ring assembly of the variator assembly, for example the second traction ring assembly 15 . The table 40 has a column 45 (“Output”) listing the planetary component, or components, configured to provide an output power. An illustrative example of an output power coupling is embodied in the second rotatable shaft 12 . Each row of the table 40 represents a continuously variable transmission configuration and the connections or couplings of planetary components. For example, the configuration listed as “1” represents a continuously variable transmission configuration having the first sun gear (S1) coupled to an input power source (Input), the second ring gear (R2) and the first planet carrier (C1) coupled to the first traction ring assembly (CVPR1), the first ring gear (R1) and the second planet carrier (C2) coupled to the second traction ring assembly (CVPR2), and the second sun gear (S2) configured to provide a power output (Output). It should be appreciated that the configurations depicted in table 40 are optionally provided with additional gear set, clutches, and shafts to suit desired operating characteristics.
[0031] Referring now to FIG. 7 , in some embodiments a continuously variable transmission (CVT) 50 is provided with a first rotatable shaft 51 adapted to receive power from a source of rotational power. In some embodiments, the CVT 50 has a second rotatable shaft 52 coaxial with the first rotatable shaft 51 . The first rotatable shaft 51 and the second rotatable shaft 52 form a main axis of the CVT 50 . The CVT 50 has a first variator assembly 53 arranged coaxial with the main axis. In some embodiments, the first variator assembly 53 is configured to be a CVP of the type depicted in FIGS. 1-3 . In some embodiments, the first variator assembly 53 has a first traction ring assembly 54 and a second traction ring assembly 55 in contact with an array of balls. In some embodiments, the CVT 50 is provided with a second variator assembly 56 arranged coaxial with the main axis. The second variator assembly 56 includes a third traction ring assembly 57 and a fourth traction ring assembly 58 . In some embodiments, the third traction ring assembly 57 is coupled to the second traction ring assembly 55 . In other embodiments, the third traction ring assembly 57 and the second traction ring assembly 55 are an integral component. In some embodiments, the CVT 50 is provided with a first planetary gear set 59 arranged coaxial with the main axis. The first planetary gear set 59 includes a first ring gear (“R1”) 60 , a first planet carrier (“C1”) 61 and a first sun gear (“S1”) 62 . In some embodiments, the CVT 50 includes a second planetary gear set 63 arranged coaxial with the main axis. The second planetary gear set 63 has a second ring gear (“R2”) 64 , a second planet carrier (“C2”) 65 , and a second sun gear (“C3”) 66 . In some embodiments, the first rotatable shaft 51 is coupled to the first sun gear (“S1”) 62 . The first ring gear (“R1”) 60 is coupled to the second planet carrier (“C2”) 65 . The first planet carrier (“C1”) 61 is coupled to the second ring gear (“R2”) 64 . The second rotatable shaft 52 is coupled to the second sun gear (“S2”) 66 The second planet carrier (“C2”) 65 is coupled to the first traction ring assembly 54 . The second ring gear (“R2”) 64 is coupled to the fourth traction ring assembly 58 . The second rotatable shaft 52 is coupled to a first gear set 67 .
[0032] Still referring to FIG. 7 , in some embodiments, the CVT 50 is provided with a third rotatable shaft 68 aligned parallel to the main axis. The CVT 50 has a third planetary gear set 69 arranged coaxial with the third rotatable shaft 68 . The third planetary gear set 69 includes a third ring gear 70 , a third planet carrier 71 , and a third sun gear 72 . The third planet carrier 71 is grounded to a non-rotatable component of the CVT 50 such as the housing (not shown). In some embodiments, the CVT 50 includes a forward clutch 73 arranged coaxial with the third rotatable shaft 68 . In some embodiments, the forward clutch 73 is a synchronizer clutch. The forward clutch 73 is coupled to a second gear set 74 . The second gear set 74 is coupled to the first gear set 67 . In some embodiments, the CVT 50 includes a reverse clutch 75 . In some embodiments, the reverse clutch 75 is a synchronizer clutch. The reverse clutch 75 is coupled to a third gear set 76 (labeled in FIG. 7 as “4a”, “4b”, and “4c”). The third gear set 76 is configured to transfer power to the reverse clutch 75 from the third sun gear 72 . The CVT 50 includes a final drive gear 77 operably coupled to the third rotatable shaft 68 . The third ring gear 70 is operably coupled to the final drive gear 77 . In some embodiments, the first gear set 67 , the second gear set 74 , and the third gear set 76 have two or more meshing gears configured to transfer rotational power. It should be appreciated that in some embodiments, the first gear set 67 , the second gear set 74 , and the third gear set 76 are optionally configured to be chains driving sprockets, or belts driving pulleys. In some embodiments, the final drive 77 is optionally configured to be a gear set or chain driving another axis.
[0033] Referring now to FIG. 8 , during operation of the CVT 50 , a forward mode of operation corresponds to the selective engagement of the forward synchronizer clutch 73 and the disengagement of the reverse synchronizer clutch 75 . A reverse mode of operation corresponds to the selective engagement of the reverse synchronizer clutch 75 and the disengagement of the forward synchronizer clutch 73 . A neutral mode of operation corresponds to the disengagement of the forward synchronizer clutch 73 and disengagement of the reverse synchronizer clutch 75 . A park mode of operation corresponds to the simultaneous engagement of both the forward synchronizer clutch 73 and the reverse synchronizer clutch 75 .
[0034] Referring now to FIG. 9 , in some embodiments, a continuously variable transmission (CVT) 150 is provided with a first rotatable shaft 151 adapted to receive power from a source of rotational power. In some embodiments, the CVT 150 has a second rotatable shaft 152 coaxial with the first rotatable shaft 151 . The first rotatable shaft 151 and the second rotatable shaft 152 form a main axis of the CVT 150 . The CVT 150 has a variator assembly 153 arranged coaxial with the main axis. In some embodiments, the variator assembly 153 is configured to be a CVP of the type depicted in FIGS. 1-3 . In some embodiments, the variator assembly 153 has a first traction ring assembly (“CVPR1”) 154 and a second traction ring assembly (“CVPR2”) 155 in contact with an array of balls. In some embodiments, the CVT 150 is provided with a first planetary gear set 156 arranged coaxial with the main axis. The first planetary gear set 156 includes a first ring gear (“R1”) 157 , a first planet carrier (“C1”) 158 , and a first sun gear (“S1”) 159 . In some embodiments, the CVT 150 includes a second planetary gear set 160 arranged coaxial with the main axis. The second planetary gear set 160 has a second ring gear (“R2”) 161 , a second planet carrier (“C2”) 162 , and a second sun gear (“C3”) 163 . In some embodiments, the first rotatable shaft 151 is coupled to the first sun gear (“S1”) 159 . The first ring gear (“R1”) 157 is coupled to the second planet carrier (“C2”) 162 . The first planet carrier (“C1”) 158 is coupled to the second ring gear (“R2”) 161 . The second rotatable shaft 152 is coupled to the second sun gear (“S2”) 163 and the first traction ring assembly (“CVPR1”) 154 . The second ring gear (“R2”) 161 is coupled to the second traction ring assembly (“CVPR2”) 155 . The second rotatable shaft 152 is coupled to a first gear set 164 . The first gear set 164 is coupled to a third rotatable shaft 165 . The third rotatable shaft 165 is parallel to the main axis formed by the first rotatable shaft 151 and the second rotatable shaft 152 . In some embodiments, the CVT 150 includes a second gear set 166 coupled to the third rotatable shaft 165 and a first synchronizer clutch 167 . The first synchronizer clutch 167 is coupled to a fourth rotatable shaft 168 . The fourth rotatable shaft 168 is coaxial with the main axis. In some embodiments, the CVT 150 includes a reverse gear set 169 coupled to the third rotatable shaft 165 and a reverse synchronizer clutch 170 . The reverse synchronizer clutch 170 is coupled to the fourth rotatable shaft 168 . In some embodiments, the first synchronizer clutch 167 and the reverse synchronizer clutch 170 are configured as a three position synchronizer clutch. During operation of the CVT 150 , engagement of the first synchronizer clutch 167 corresponds to operation in a forward direction. Engagement of the reverse synchronizer clutch 170 corresponds to operation in a reverse direction.
[0035] It should be noted that the description above has provided dimensions for certain components or subassemblies. The mentioned dimensions, or ranges of dimensions, are provided in order to comply as best as possible with certain legal requirements, such as best mode. However, the scope of the preferred embodiments described herein are to be determined solely by the language of the claims, and consequently, none of the mentioned dimensions is to be considered limiting on the inventive embodiments, except in so far as any one claim makes a specified dimension, or range of thereof, a feature of the claim.
[0036] While preferred embodiments have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the preferred embodiments. It should be understood that various alternatives to the embodiments described herein may be employed in practicing the preferred embodiments. It is intended that the following claims define the scope of the preferred embodiments and that methods and structures within the scope of these claims and their equivalents be covered thereby.
|
Devices and methods are provided herein for the transmission of power in motor vehicles. Power is transmitted in a smoother and more efficient manner by splitting torque into two or more torque paths. A continuously variable transmission is provided with a ball variator assembly having two arrays of balls, a planetary gear set coupled thereto and an arrangement of rotatable shafts with multiple gears and clutches that extend the ratio range of the variator. In some embodiments, clutches are coupled to the gear sets to enable synchronous shifting of gear modes.
| 5
|
FIELD OF THE INVENTION
The invention relates generally to videoconferencing. More particularly, the present invention relates to methods and systems for videoconferencing with integrated therein feedback, prediction and image degrading mechanisms to continuously display on the local video display a predicted video, which simulates how a local party is viewed at a remote system.
BACKGROUND OF THE INVENTION
In current video conferencing systems the local video is streamed directly from the local camera to the local display (see FIG. 1 ). With the current technology, the local video is always shown in great quality. In contrast, the video from the remote location often appears with many artifacts. The remote video quality degradation is due to network artifacts such as packet lost, congestion, delay, jitter, or inadequate computation processing resources such slow CPU, shortage of memory, etc.
Since the local video is always shown in great quality independent of network conditions, the local party may actually think that the remote party can see him/her/them clearly when in fact the remote party might see him/her/them with heavy video/audio distortion or the remote party might not see the local party at all. This often forces the remote party to ask the local party to repeat himself, herself or themselves, results in miscommunication or leads to irritating situations. A remote party may not be able to ask the local party to repeat himself, herself or themselves until the network condition improves. Network conditions may not improve until several minutes later during the videoconferencing, which is highly disruptive to the conversation. Sometimes the remote party may not even know that they missed something, for example, the local party may smile at the remote party, and this smile may be lost or distorted due to network conditions. Such conditions are extremely hurtful to the conversation, where bad video is often worse than no video at all.
Some systems include feedback mechanisms such as a symbol (e.g. a bright yellow lighting mark) or text messages on the remote video's display in case the network condition is poor. Unfortunately, such feedback mechanisms still make it difficult for a local party to learn the meaning of symbols or text messages since it does not capture the actual video degradation. Furthermore, symbols or text do not capture the varying degree of network degradation of video quality. It would therefore be considered an advance in the art to develop new systems and methods whereby the local party actually sees how he/she/them is/are viewed on a remote video display during a videoconference in a continuous manner. Such a continuous feedback system would allow the party to continuously adjust and adapt to how he/she/them is/are seen to maximize communication effectiveness; e.g. delay smiling until after a network congestion has passed.
SUMMARY OF THE INVENTION
The invention enables a local party to see how a remote party is viewing himself, herself or themselves during a videoconference. This is accomplished by predicting and changing the local video to a similar video quality level as the video quality displayed on a remote display. This process occurs without any input from the involved parties. Instead the prediction and changing of the local video occurs in an automatic fashion and continuously.
The present invention is a video-feedback mechanism in which the local party obtains continuous video-feedback regarding the network conditions and/or remote system. The predicted and degraded local video represents the state of the video displayed remotely and is a function of the network conditions and/or remote system.
A party is defined as one or more users at either the local or remote location. Each party and even each user in a party could have more than one camera and/or display.
BRIEF DESCRIPTION OF THE FIGURES
The present invention together with its objectives and advantages will be understood by reading the following description in conjunction with the drawings, in which:
FIG. 1 shows a videoconferencing system according to a prior art example. The local video of the local party comes directly from the local camera. The grey box (remote video of local party) indicates lower video quality than the white box (local video of local party)
FIG. 2 shows a videoconferencing system according to the present invention. The local video of the local party includes feedback information from the network and/or remote system. The local video of the local party is predicted and changed to represent how a remote party views the local party. The grey boxes (remote video of local party and local video of local party) indicate similar video quality, though of lower quality than the white box as in FIG. 1 .
FIGS. 3-4 show two examples of implementation according to the present invention.
FIG. 5 shows a prior art example with the same view of the local party to both the local and remote display, either both mirrored or both not mirrored.
FIG. 6 shows a mirroring mechanism according to the present invention to mirror the video of the local party to match the actual position/presence of the local party.
DETAILED DESCRIPTION OF THE INVENTION
The videoconferencing system includes a local system with a local party, a local video camera, a local video display for the local party, and a local video processor to process the local video from the local video camera. It further includes a remote system for the remote party with a remote video display for the remote party, and a remote video processor to process the local video received from the local video camera. A network connects at least the local video camera, the local video display, the local video processor, the remote video display and the remote video processor. The videoconferencing system further includes a feedback mechanism from the remote video processor to the local video processor. This feedback carries information regarding the remote system and the network, such as network condition statistics and processor, memory or input/output device load of the remote system.
With the obtained feedback as input, a prediction and image degrading mechanism is integrated in the system to predict the remote video degradation between the local video displayed on the remote video display and the local video displayed on the local video display. Once a prediction is obtained, this mechanism then degrades the quality of the local video, which is displayed on the local video display. The predicted and degraded video is then displayed through a displaying mechanism in a continuous manner on the local video display to the local party. The preferred location of the prediction and imaging degrading mechanism is at the local site since the goal of these modules/mechanisms is to reduce the video quality from the local camera to the local display.
Before implementation of this invention the local video displayed on the remote display is degraded in quality compared to the local video displayed on the local display as shown in FIG. 1 . After implementation of this invention similar video quality is achieved as shown in FIG. 2 by the two grey boxes, i.e. local video of local party and remote video of local party having the same shade of grey. This is in contrast to FIG. 1 where the two boxes of the local video of local party and the remote video of local party are different, i.e. the local video of the local party is of higher quality (white box) than the remote video of the local party (grey box). In the example of FIG. 2 both grey boxes indicate lower video quality than the white box in FIG. 1 .
There could be several factors that influence the degradation of the local video at the remote party end. For example, network data transmission-delay, transmission loss, transmission jitter, and the condition of the general and/or video processor such as processing load, memory usage, etc. Such information could be used as feedback to the prediction and degradation mechanism, which could contain several blocks. Example of block components of the prediction and degradation mechanism are a frame rate differential buffer, video compression, a delay buffer, a prediction buffer on the network condition statistics, a prediction video decompression based on the processor memory or input/output load of the remote system, a image warping module or any combination thereof. These blocks could be used in various combinations of which two examples are discussed herein, but first some examples of feedback information are discussed.
A. Data Packet Transmission-Delay
The data packet transmission-delay is measured as how much time it takes for a packet to transmit and travel from one party/user terminal to another. This delay could range from less than 1 millisecond to more than 30 seconds. Some examples are:
1 ms—party/user terminals located on the same broadband local area network 30 ms—party/user terminals located within same city, connected via broadband 100-150 ms—party/user terminals located within the U.S., connected via broadband 250-350 ms—party/user terminals located within the world, connected via broadband >350 ms—party/user terminals connected with Dial Up Modem, satellite, or cellular data network
B. Data Packet Transmission Loss
The video data stream is converted into data packets and transmitted over the network. Data packets might get lost due to network problems such congestions. Such a loss ratio might range from 0% to 100%, for example:
if the data packets loss ratio is 0%, then the remote video quality is as good as the local video quality, assuming no other adverse network or processing conditions if the data packet loss ratio is between 0% and 100%, then the remote video of a local party is being affected. In such a case the local party should be made aware how the local party is being displayed by the remote party. if the loss is 100%, then no video stream is received and the local party should be made aware that the remote party can no longer see him, her or them.
Data Packets could be lost in different manners, for example:
1 out of every 10 data packets is lost (10% loss), which could be argued that the video quality may still be acceptable. This manner of data packet loss might range from 0% to 100%. 10 consecutive data packets are lost in 100 (10% loss), which could be argued that the video quality might be severely degraded. This manner of data packet loss might range from 0% to 100%.
The data packet loss ratio and loss manner must be fed back from the data packet receive terminal to the data packet transmit terminal. The data packet loss information feedback might be delayed from 0 to >30 sec, depending on the network conditions.
One way to combat the data packet loss problem is to re-transmit the lost data packets; but this will increase the need for more data transmission bandwidth and increase video transmission delay. Another way is to transmit redundant data packets, which will also increase the need for more data transmission bandwidth and increase video transmission delay. Either method or both methods could be used. In case of the latter the method could be decided dynamically at runtime depending on the exact scene and network conditions.
C. Video Data Processing Unit Condition
An impaired processing unit can also cause video quality degradations. If the processing unit is slow or load saturated, it cannot process the received and transmitted video information fast enough to render satisfactory videoconferencing experience. Significant data packet processing delays ranges from <1 ms to >30 seconds and/or data packet loss ranges from 0% to 100% could result from the processing unit being unable to fully perform its functions. This impaired condition could be temporary or permanent.
FIGS. 3-4 shows two example implementations of the invention. One implementation utilizes video compression and predictive video decompression as shown in FIG. 3 . The other implementation uses an image-warping module as shown in FIG. 4 . The implementation in FIG. 3 will render more exact mimicking of the local video of the local party to the remote video of the local party, in comparison to image-warping module method. However, the method of FIG. 3 may require a higher computation load in comparison to image-warping module method.
The following sections describe the individual blocks/components and their interactions as shown in the embodiments of FIGS. 3-4 .
Frame Rate Differential Buffer
Cameras often would produce video of a certain frame rate, and the remote system, together with network limitations, may limit the actual frame rate delivered to the remote party. A frame rate differential buffer reduces the frame rate of the local video of the local party to match the actual video frame rate received at the remote system.
Delay Buffer
The Delay Buffer is used to insert delay into local video to the local party. The inserted delay preferably matches the amount of network delay at any given time. If the delay is less than a certain predetermined or automatically determined threshold (e.g. 200 ms), no Delay is inserted. By deliberately delaying the local video of local party, the local party can determine how the remote party is viewing the local party. The reason that network delays less than a certain threshold is not inserted in the delay buffer is that remote parties/users typically cannot detect delays less than around 250 ms. However, inserting this amount of delay into the local delay buffer results in a noticeable and annoying lag of the local video, which negatively impact the local video experience. This implementation only inserts the delay to reflect adverse network conditions. Thus, in the typical operation, no delay is inserted until an adverse network event.
Video Compression
The video compression block is used to perform video compression for transmission of the local video to the remote party.
Prediction Buffer
The prediction buffer is used to manipulate the compressed local video data utilizing the network condition statistics feedback from the remote terminal. A calculated prediction is made to mimic network condition likely experienced by the remote terminal. For example, from the network conditions feedback, if 10 percent of the packets are known to be lost, then 10 percent of the packets are removed from the prediction buffer, simulation the condition of network packet loss for the local video of the local party. The feedback information may contain aggregate statistics, a probabilistic profile, or the exact packets that were lost.
Predictive Video Decompression
The predictive video decompression block is used to take the output of the prediction buffer, which is the compressed local video data that has been altered to mimic degradation due to network conditions. This block will decompress the predication buffer output, utilizing the remote terminal processor, memory, and IO device (input/output) load information. The output of this block is displayed as local video of the local party.
Image Warping Module
The image warping module/block is used to take the output of delay buffer and frame rate differential buffer. Subsequently with the network condition statistics and remote processor, memory, and IO device load information, this module renders or warps certain pixel or blocks of pixels, which results in erroneous representation of the video images in certain localized locations. The result of the warping is to mimic the effect of adverse network or system conditions. The output of this block is displayed as local video of the local party.
An additional aspect of the invention is the local video mirror ( FIG. 6 ). This local mirror is implemented such that local video is mirrored in for example the image-warping module or the predictive decompression module. This mirroring mechanism allows the local video to appear like a mirror and yet the remote people will still see the local person from the correct perspective. Existing videoconferencing systems present the same view of the local party to both the local video and the remote video; either both are mirrored or both are not mirrored ( FIG. 5 ).
The present invention has now been described in accordance with several exemplary embodiments, which are intended to be illustrative in all aspects, rather than restrictive. Thus, the present invention is capable of many variations in detailed implementation either in hardware and/or software, which may be derived from the description contained herein by a person of ordinary skill in the art. For example, there could be multiple locations each having one or more parties. In those cases, the local video feedback could be a function of (a) the worst case of all remote locations, (b) a picture-in-picture of local video attached to each remote location video, (c) or two classes of remote site. For the latter one have four remote sites and two of those sites have good networks and the other two have bad networks. The present invention could then use two different methods to stream video to the good sites and to the bad sites, and then one would show how the good and bad sites can see the local sites/parties, respectively. All such variations are considered to be within the scope and spirit of the present invention as defined by the following claims and their legal equivalents.
|
A system and method enabling a local party to see how a remote party is viewing him/her during a videoconference is provided. This is accomplished by predicting and changing the local video to a similar video quality level as the video quality displayed with which the local video is displayed on a remote display. This process occurs without any input from the parties/user(s). Instead the prediction and changing of the local video occurs in an automatic fashion and continuously.
| 7
|
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to a mechanical connection using non-circular inter-fitting components for transmitting torque. In particular to shaft/hub connection for transmitting torque.
BACKGROUND OF THE INVENTION
[0002] In a typical machine construction, shaft/hub connections are used in may ways for transmitting torques between the shaft and hub. In addition to many requirements, the basic task of such types of connections is usually the transmission of high torques. For transferring such torque, the connections should be as compact and light as possible. In addition, it should be mountable without extensive installation and adjustment work. Dynamic loads are usually higher than static loads.
[0003] Since conventional shaft/hub connections usually don't deal with an interference fit, only a certain portion of their contact surfaces truly participates in torque transmission. This causes high stresses in the components, which must be compensated for or reduced by an appropriately long connection. But the connection's enlarged length again causes larger radial run-out and reinforces a relative motion between shaft and hub, during which no transmission of torque occurs (the so-called play). Enlargement of radial run-out also leads to undesired noises and vibrations. A longer connection moreover facilitates sliding of the surfaces upon each other, which again promotes the formation of fretting corrosion. Finally, these effects lead to a reduction in the lifetime of the shaft/hub connection and consequently that of the entire system.
[0004] DE 198 36 259 A1 shows a tight shaft/hub connection in which, to diminish or prevent the undesired play, a radial pressing device presses the hub toward the rotational axis in such a manner, that the hub's inside contour engages the shaft free of play. The disadvantage of this embodiment is the need of additional components, which is associated with higher space requirements and costs.
[0005] Clamping-bush connections, in which a clamping-bush fits closely between the shaft and hub, are also a known means to reduce or prevent unwanted play. Such a clamping-bush demonstrates at least one element that enables the clamping-bush's annular cross section to be enlarged, thereby pressing the clamping-bush against the shaft's lateral surface on one side and against the hub boring's inner surface on the other side, creating a connection free of play. DE 36 36 393 A1 describes clamping-bushes of such a type, in which positive locking is achieved by fitting both shaft and hub with longitudinal toothing, the clamping-bush being fitted with a matching toothing both on its inside and its outside. This embodiment too is associated with correspondingly higher costs and higher space requirements due to its extra components. More time and a consequently more cost-intensive work step is needed to assemble the clamping-bush.
[0006] Wedge-shaped elements, which are inserted between shaft and hub, are also well known. But these lead to an eccentricity of the shaft and therefore to point contacts or relatively small contact surfaces between shaft and hub. Therefore, there is a need in the industry to manufacture a shaft/hub connection that eliminates the above problems.
SUMMARY OF THE INVENTION
[0007] It is the objective of the present invention to create a mechanical connection with high functionality and lifetime for transmitting torque. It is yet another objective for the shaft/hub connection to be inexpensive to manufacture and easy to assemble.
[0008] The above objects are accomplished by having at least one of the components in the region of the slaving section, demonstrates at least two retaining sections angularly displaced to each other around the longitudinal axis.
[0009] The invention is based on the knowledge that a reduction of the play between shaft and hub can only diminish or neutralize high stresses in the component, fatigue, true running, and vibrations and only lead to the objective if the reduction of play occurs while there is a more centered position of the shaft in the hub. The inventors have discovered that longitudinal sections of one of the components, mutually displaced around their longitudinal axis and located in the region of the slaving section, ensure the shaft's centricity within the hub, thereby achieving a more uniform transmission of torque. This can be achieved for example by torsion that extends across the entire length of the slaving section or also by two untorqued longitudinal sections that are connected to each other by a connecting section and mutually displaced therein. Several connecting sections, whose longitudinal sections are displaced against each other in steps or continuously, are also possible.
[0010] The reduction or neutralization of play in a centered shaft leads to a more favorable distribution of energy during torque transmission, thereby reducing stresses in the component, fatigue, true running, and vibrations. It is easy and quick to join, especially to thread, or to insert the connection together.
[0011] Continuous torsion permits the shaft to be inserted forward into the hub using an input cross section, the hub then turns because of the torsion as insertion becomes deeper and both the input and output cross sections come into contact with the hub. The terms input and output cross section are understood in terms of the shaft's direction of insertion into the hub and refer to the opposite ends of the slaving section.
[0012] The shaft's depth of insertion into the hub can be used both to reduce play by means of closely fitting (prestressing) the shaft on the hub and finally achieve a clamping action between shaft and hub. Transmission of torque in both directions free of play and change of direction free of play are consequently possible. Contact points or surfaces arise between the hub and shaft in all cases, at least in the regions of the shaft's input and output cross sections. Due to the elasticity or plasticity of the material, intensified torsion before or during the transmission of torque can achieve a close fit along the entire length of the slaving section through deformation of the shaft and/or hub.
[0013] Moreover the degree of torsion can influence and determine different functions and parameters of the shaft/hub connection. A small degree of torsion, for example, means that stronger turning of the torqued component is necessary or possible until the desired effect, such as complete neutralization of play, has been attained. In contrast, torsion progressively running in the direction of the output cross section leads to easy insertion followed by increased turning of the shaft on an increasingly shorter segment. A diminishment or neutralization of play and a clamping action can be rapidly and easily achieved during assembly due to the short insertion distance. Degressive torsion in the direction of the delivery cross section is also conceivable for special applications. Mixed shapes, namely torqued components that can be changed (degressive, progressive, linear) across the length of the slaving section, are possible.
[0014] Polygonally shaped, especially trochoidally shaped cross sections of the shaft and hub have proven advantageous. A trochoid arises as the trajectory of a point as the point is carried along when a circle (moving circle) rolls along on or in a circle (rest circle). The number of and implementation of the trochoidal “indentations and bulges” are variable. It has been shown that it is possible to transmit torque with minimum stress and, at the same time, with minimum relative motion between touching surfaces by using a trochoidal contour that has been optimized with respect to the number of “indentations and bulges” and to their large and small diameters. Small differences in the contour of the touching components enable the properties of the shaft/hub connection to be changed, its lifetime and stability in particular.
[0015] The shaft/hub connection according to invention is particularly suited for use in automotive engineering, such as for the braking systems and wheel suspensions of motor vehicles. Here it is advantageous that a hub with polygonal inside contour according to invention doesn't have to be broached. It is consequently unnecessary to manufacture it out of steel, the hub could be produced from cast iron for example. The shaft/hub connection according to invention is therefore also suitable in particular for use of this type, because brake systems for example are exposed to high thermal loading.
[0016] The invention shall be explained in more detail based on preferred embodiments illustrated in the drawing. It shows:
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a cross sectional view of a shaft/hub connection in the region of the input cross section according to the present invention;
[0018] [0018]FIG. 2 is a cross sectional view of a shaft/hub connection in the connection's central region according to the present invention;
[0019] [0019]FIG. 3 is a cross sectional view of a shaft/hub connection in the region of the output cross section according to present invention;
[0020] [0020]FIG. 4 is a perspective view of a shaft/hub connection wherein the shaft demonstrates untorqued shaft sections that are connected to each other by a torsion section according to the present invention;
[0021] [0021]FIG. 5 is a perspective view of the manufacture of the shaft depicted in FIG. 4; and
[0022] [0022]FIG. 6 is a partially cut perspective view of a shaft/hub connection for a motor vehicle's braking system according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The following description of the preferred embodiment is merely exemplary in nature, and is in no way intended to limit the invention or its application or uses.
[0024] Referring to FIG. 1, a shaft/hub connection is generally shown and represented by reference numeral 1 . The shaft 1 hub connection 1 comprises a shaft 2 and hub 4 . The examples presented in FIGS. 1 through 4, for example, each demonstrate one shaft 2 and one hub 4 .
[0025] [0025]FIGS. 1 through 3 show a cross section through a shaft/hub connection 1 according to invention. A shaft 2 with an external contour 6 is guided into a hub 4 with its inside contour 8 . The shaft 2 demonstrates trochoidal bulges 9 and the hub 4 demonstrates a corresponding trochoidal indentations 11 relative to its cross section. All other out-of-round cross section shapes are also fundamentally suitable for implementing the invention. A six-sided polygon in particular has proven particularly suitable for transmitting the torque. It has likewise been shown for a six-sided polygon, that a relative eccentricity Ε between 2 und 10%, preferably between approximately 3 and 5% should be specified. The relative eccentricity Ε describes the polygon's eccentricity relative to the non-physical average diameter D m in percent, thus describing a relationship between an external diameter D o and an internal diameter D i of the polygon. D m is the diameter of a circular disk with the same area as the polygon. The term polygon is not to be understood here within its strictest meaning, but rather as an approximate, polygon-like, multi-angular shape. The relative eccentricity E can be computed by the following formula:
Ε=D i +2×ε
[0026] where
ε=polygon's out-of-roundness
[0027] The relative eccentricity Ε should preferably be derived from the following formula:
Ε=( D o −D i /D o −D i )×50
[0028] Particularly advantageous polygonal shapes result can be computed from the following formulas in particular (deviation +/−10%):
x (γ)=( D m /2)×cos(γ)+ε×cos((n−1)×γ)
y (γ)=( D m /2)×sin(γ)−ε×sin((n−1)×γ)
[0029] where
γ=0 to 360°, continuous parameter
n=number of sides on the polygon
ε=Ε ×D m ×100
[0030] For explanation, FIG. 4 shows a three-dimensional principle illustration of the shaft/hub connection 1 according to the invention. Shaft 2 with trochoidal bulges 9 can be inserted into hub 4 , which also possesses a trochoidal inside contour 8 . Shaft 2 has an input cross section 10 and an output cross section 12 , wherein the terms “input” and “output” are understood to mean the insertion direction of the shaft into hub 4 ; the input cross section 10 for example, is inserted into hub 4 in the axial direction until the hub has surrounded the output cross section 12 . In their joined state, shaft 2 and hub 4 demonstrate a mutual longitudinal axis X-X. In their state of assembly, the contact region between the shaft 2 and hub 4 that transmits a torque is labeled as a slaving section 14 . Due to manufacturing tolerances, the slaving section 14 is generally shorter than the geometric length of the shaft 2 that can be inserted into hub 4 .
[0031] In the illustrated examples, the cross section or inside contour 8 of hub 4 is constant across the entire length of the slaving section 14 , and is thus neither torqued nor angularly displaced.
[0032] [0032]FIGS. 1 through 3 relate to a joined shaft/hub connection 1 with a shaft 2 that is continuously torqued over the entire length of the slaving section 14 . After the input cross section 10 has been inserted into the hub 4 , the torsion from shaft 2 presses the mostly trochoidal bulges 9 against the inside contour 8 of the hub 4 as further insertion occurs. The play of shaft 2 , initially present due to the different cross sectional surfaces of shaft 2 and inside contour 8 , diminishes and is neutralized when both the input cross section 10 and output cross section 12 of shaft 2 both fit closely within the hub. Depending on the expenditure of energy, pre-stressing or clamping of the shaft 2 in the hub 4 can be achieved as shaft 2 is further inserted or turned without shaft 2 becoming eccentric.
[0033] [0033]FIG. 1 shows a cross section of the shaft/hub connection 1 in the region of the input cross section 10 , FIG. 2 a cross section of the central section of the slaving section 14 , and FIG. 3 a cross section in the region of the output cross section 12 . The close fit of the trochoidal bulges 9 of shaft 2 to the trochoidal indentations 11 of hub 4 is clearly seen. In contrast to the central section of shaft 2 (FIG. 2), shaft 2 fits closely to hub 4 both in the region of its input cross section 10 (FIG. 1) and in the region of its output cross section 12 (FIG. 3).
[0034] [0034]FIG. 4 shows a shaft 2 with trochoidal cross section that demonstrates three longitudinal sections in the region of the slaving section 14 . The illustration is only to be understood as demonstrating the principle. The geometric ratios are not reflected perfectly for the sake of better understanding. Starting from the input cross section 10 , a torqued connecting section 20 connects a first retaining section 18 with a second retaining section 22 , wherein the two retaining sections 18 , 22 demonstrate an angular displacement to each other around their longitudinal axis X-X due to the torsion of connecting section 20 . The trochoidal bulges 9 of retaining sections 18 , 22 each run parallel to one another. After the input cross section 10 has been inserted, such an embodiment results in a straight, tight insertion of shaft 2 after the connecting section 20 has come into contact with hub 4 upon further insertion, the shaft 2 is turned around its longitudinal axis X-X and the second retaining section 22 pressed against the hub's inside contour. The angular displacement of the retaining sections 18 , 22 to one another diminishes the play in the connection in its joined state. Both retaining sections 18 , 22 fit closely to hub 4 along their entire length and consequently each consequently participates in transmitting torque along its entire length. The bulges 9 , which run along the connecting section 20 , make an angle α with the longitudinal axis X-X, an angle that can be executed so gently that it excludes selflocking between shaft 2 and hub 4 . If the angle a is implemented in such a manner that selflocking exists between shaft 2 and hub 4 , then an elastic or plastic deformation of shaft 2 will be necessary when shaft 2 is inserted into hub 4 .
[0035] In a particularly advantageous embodiment, the length of the connecting section 20 amounts to less than 30% of the entire length of the slaving section 14 . In principle, it should be endeavored that the connecting section 20 be particularly short, because it would then barely or not at all participate in transmitting torque in the joined state of the shaft/hub connection 1 . Given an appropriate degree of torsion, this embodiment can achieve that the components can move relative to each other axially at the same time that both retaining sections 18 , 22 are in contact with the hub 4 . The angular displacement thus permits torque to be transmitted without play for a prestressed connection.
[0036] In an illustration principally representing an example, FIG. 5 explains the manufacture of a shaft 2 that is depicted in FIG. 4. The shaft 2 , which demonstrates trochoidal bulges 9 , is clamped into two lathe tools 24 , which are then turned relative to each other by the desired amount in correspondence with the sketched directional circles.
[0037] [0037]FIG. 6 shows the use of a shaft/hub connection 1 according to invention within a braking system 26 in a partially cut perspective illustration. The braking system 26 demonstrates a brake disk 28 , which is connected with the hub 4 . Slaving segment 14 , demonstrating two retaining sections 18 , 22 and one connection section 20 , can be clearly recognized. The trochoidal external contour of shaft 2 continuously changes proceeding from input cross section 10 toward output cross section 12 . Die trochoidal bulges 9 of shaft 2 are less pronounced in the region of the input cross section 10 than in the region of the output cross section 12 .
[0038] Torque transmission at a minimum of stress and minimum relative motion between the components at the same time is possible by using a trochoidal contour that has been optimized with respect to the number and dimensions of the bulges 9 and indentations 11 . Small differences in the contour of touching components permit further improvement in the properties of the shaft/hub connection 1 , especially its lifetime and stability. The degree of torsion moreover makes it possible to position shaft 2 into hub 4 exactly.
[0039] The minimum length of the slaving section 14 of the shaft/hub connection 1 is determined by working loads and is shorter for the embodiment according to invention than for conventional connections. Reduction of the connecting length leads to diminishment of the play and to improvement of noise and vibration phenomena. The minimum length is the length that suffices to absorb all occurring forces and to transmit the required torque. The number of trochoidal bulges 9 and indentations 11 should be as small as necessary in order to avoid unnecessary restrictions on the rotational motion between shaft 2 and hub 4 in the peripheral direction. Concavely bent sides of shaft 2 , as illustrated in FIGS. 1 through 3, are particularly preferred.
[0040] Another conspicuous property of this invention is that the same or different materials can be used for shafts 2 and hubs 6 . When the shaft/hub connection 1 according to invention is used for the wheel suspensions of motor vehicles for example, hub 2 can produced out of cast iron rather than steel, whereby broaching of hub 2 may be dispensed with. Interesting materials for manufacturing shaft/hub connections 1 according to invention include ceramics, aluminum, steel, MMC, and globular and laminar cast iron. All combinations of these materials can be used.
[0041] Shaft 2 or hub 4 or even both components can be torqued in principle. To achieve a fit of shaft 2 and hub 4 that is as exact as possible and to pre-stress them, it is possible to first torque shaft 2 within hub 4 in its inserted state and then remove shaft 2 completely and torque it at another defined angular amount outside of hub 4 .
[0042] Continuous change of shape of the cross-sectional area of shaft 2 or hub 4 at the same time as torsion across the length of slaving section 14 may also be reasonable. The input cross section 10 and output cross section 12 will then each demonstrate a different cross section. An embodiment of the components can also occur using a cone angle between shaft 2 and hub 4 .
[0043] The foregoing discussion discloses and describes a preferred embodiment of the invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that changes and modifications can be made to the invention without departing from the true spirit and fair scope of the invention as defined in the following claims.
|
The invention relates to a mechanical connection for transmitting torque, demonstrating a common longitudinal axis a shaft rotating around the longitudinal axis and a hub coaxial to the shaft, its inside contour surrounding the shaft via a slaving section, wherein in the area of the slaving section, the shaft and the inside contour of the hub comprise of at least one retaining section with out-of-round cross section for transmitting torque. In the region of the slaving section, at least one of the shaft or the hub demonstrates at least two retaining sections angularly displaced to each other around the longitudinal axis.
| 5
|
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is the U.S. National Stage of International Application No. PCT/EP2011/001764, filed Apr. 8, 2011, which designated the United States and has been published as International Publication No. WO 2011/128045 and which claims the priority of German Patent Application, Serial No. 10 2010 015 465.2, filed Apr. 16, 2010, pursuant to 35 U.S.C. 119(a)-(d).
BACKGROUND OF THE INVENTION
The invention relates to a ground-drilling device with a basic body and a drill head which is supported for movement in longitudinal axial direction relative to the basic body.
A ground-drilling device with a drill head which is supported for movement relative to a basic body is known for example from DE 195 08 542 A1. This is a self-propelled ground-drilling device, a so called ground rocket. This ground rocket has a basic body within which an impact piston is supported for movement in longitudinal axial direction. The impact piston is caused to cyclically move back and forth by the supply of compressed air, wherein in every cycle the impact piston impacts a front impact surface, whereby ultimately the kinetic energy of the impact piston is transferred to the basic body of the ground rocket to advance the latter in the soil. The front impact surface is formed by an impact bolt which is part of a drill head of the ground rocket. The drill head is supported in the basic body for movement in longitudinal axial direction; for guiding the relative movement between the drill head and the basic body the impact bolt is supported within a corresponding opening of the basic body. In addition, the impact bolt has a ring shaped shoulder at its section which extends into the basic body, with a diameter of the ring shaped shoulder being greater than the diameter of the opening into the basic body. This shoulder serves for transferring the energy which is initially transferred from the impact piston to the impact bolt or the drill head to the basic body after a defined relative movement between the drill head and the basic body. The advancement of the ground rocket in the ground occurs thus in two stages: first, the drill head is advanced by a defined distance in that the impact piston impacts the impact surface of the impact bolt; after a defined movement of the drill head relative to the basic body the ring shaped shoulder of the impact bolt impacts the impact surface of the basic body, whereby the residual energy is transferred to the basic body in order to cause the basic body to follow the drill head in the bore.
The ring shaped shoulder of the impact bolt together with the corresponding section of the basic body forms a free space whose size varies depending on the position of the drill head relative to the basic body. This free space is connected with the working chamber of the basic body via the annular gap between the ring shaped shoulder and the inner wall of the basic body, within which basic body the impact piston is cyclically moved. Although this annular gap is small it is not sealed for reasons of cost thus allowing (partial) pressure compensation between the working chamber and the free space, whereby pressurized air which was conducted into the working chamber, flows over into the free space. Because the pressure compensation between the free space and the working chamber occurs relatively slowly, an overpressure may be present in the free space after the ventilation of the working chamber, which overpressure impedes a return movement of the drill head into its retracted position. In order to avoid this, it is provided to connect the free space additionally to the environment so that an overpressure which forms in the free space can not only be released to the working chamber but also to the environment. In the ground rocket of DE 195 08 542 A1 this occurs via the also not sealed support of the impact bolt in the opening of the basic body.
The pressure compensation between the free space and the environment, is associated with the disadvantage that the entering of contaminations from outside into the free space through the non-sealed support of the impact bolt is even exacerbated; because the movement of the drill head relative to the housing into its front position first generates a negative pressure due to the speed with which this movement occurs, which negative pressure “draws” contaminations into the free space. These contaminations on one hand increase the wear of the movable components of the ground rocket and can lead to a decrease or loss of movability of the drill head.
SUMMARY OF THE INVENTION
Proceeding from this state of the art, the invention was based on the object to set forth an improved ground-drilling device with a movable drill head. In particular, the entering of undesired contaminations into the free space between the movable drill head and the basic body of the ground-drilling device is intended to be prevented with the ground-drilling device according to the invention.
This object is solved with a ground-drilling device which includes a basic body and a drill head which is supported for movement in longitudinal direction relative to the basic body, wherein between the drill head and the basic body a free space is formed whose sized is variable owing to the movable support, and a sealing element for sealing the free space against the environment, wherein the sealing element is configured as valve element, which opens when an overpressure is present in the free space to establish a pressure compensation, and which is closed when an negative pressure is present in the free space to prevent a pressure compensation. Advantageous refinements of the ground-drilling device according to the invention are the subject matter of the dependent patent claims and result from the following description of the invention.
The essence of the invention is to seal the free space which is formed between the movable drill head and the basic body with a sealing element, in which free space at times a negative pressure is present, and at times an overpressure is present, which sealing element is configured according to the invention so as to function as valve element which releases an overpressure present in the free space and when a negative pressure is present in the free space seals, in order to prevent the entering of contaminations into the free space as far as possible.
A ground-drilling device according to the invention has thus a basic body and a drill head which is supported for movement in longitudinal axial direction relative to the basic body (i.e., in the drilling direction), wherein between the drill head and the basic body a free space is formed which is variable in its size; further a sealing element for sealing the free space against the environment is provided, wherein the sealing element is configured as valve element which opens when an overpressure is present in the free space to effect a pressure compensation and which is closed when a negative pressure is present in the free space to prevent a pressure compensation.
A ground-drilling device according to the invention can be any device with which bores, and in particular horizontal bores, can be introduced into the ground. Particularly preferably, they are however self-propelled ground-drilling devices, so called ground rockets which are equipped with an internal impact mechanism (impact piston) which is propelled via supply of a pressure fluid and in particular of a pressure gas (pressurized air).
In a preferred embodiment of the ground-drilling device according to the invention, the sealing element has a sealing lip which is configured as slanted process. Such a sealing lip ensures on one hand the desired function for opening a passage only in case of an overpressure and is on the other hand easy to produce and with this cost effective.
In a further preferred embodiment of the drilling device according to the invention, the sealing element is configured or integrated into the ground-drilling device so that a defined passage between the free space and the environment is formed, wherein the passage is released or closed by the sealing lip depending on the pressure conditions. Such a defined passage between the free space and the environment enables a pressure compensation, insofar this is required for the function of the movable drill head. The additionally provided sealing lip allows sealing this defined free space in a simple manner when the entering of contaminations into the free space is to be prevented in a manner according to the invention.
Preferably, the sealing element can have a recess into which the sealing lip can descend in order to release the passage between the free space and the environment, in the case of an overpressure. This in turn allows ensuring a most unimpeded pressure compensation between the free space and the environment in the case of an overpressure in the free space.
Because the housing as well as the drill head of ground-drilling devices normally have a circular cross section, the sealing element according to the invention can be easily integrated into the housing when it is configured as sealing ring.
In a preferred embodiment of the ground-drilling device according to the invention the sealing element can exclusively or in addition, have at least one adjusted ventilation bore which connects the free space with the environment. This ventilation bore can be configured (i.e. adjusted) so small that a flow of pressurized gas can occur from the free space into the environment when an overpressure is present in the free space, at the same time however, an aspiration of contaminations is largely prevented when a negative pressure is present in the free space (this negative pressure is normally only present for a short time and with a smaller (compared to the overpressure) pressure differential). An aspiration of contaminations by the ventilation bore can also be prevented by an adjusted integration of the ventilation opening into the sealing element, in that for example the aspirated flow is deflected multiple times, before it enters the free space. These deflections can prevent that contaminations, in particular in form of relatively heavy particles or droplets actually proceed as far as into the free space.
In a particularly preferred embodiment, the at least one ventilation opening can be combined with a further sealing part (in particular a sealing lip) of the sealing element, which sealing part functions as valve element. The ventilation opening can then be arranged that the pressure gas flow which exits from the ventilation opening when an overpressure is present in the free space, flows against the region before for example the sealing lip, whereby the sealing lip which can take over the actual function of the pressure compensation is kept free of contaminations. This allows ensuring a durable function of the sealing lip.
As explained before, the ground-drilling device according to the invention is preferably constructed as self-propelled ground rocket and has thus an impact piston which is moved to oscillate within the housing and which can cyclically impact a front impact surface of the ground rocket, in order to advance the ground-drilling device in the drilling direction.
Such a ground rocket according to the invention can preferably further have a threaded ring with an outer threading, which threaded ring is screwed into a corresponding inner threading of the housing and serves for transferring the energy which is transferred by the impact piston to the housing. This threaded ring can preferably simultaneously serve as support for the movable drill head, for which purpose the ground drill device can further have an impact bolt which is connected with the drill head and extends through the threaded ring. The impact bolt can protrude over the threaded ring so that the impact piston first impacts the impact bolt and thereby moves the drill head relative to the housing.
Because such a threaded ring serves for transferring the impact energy, it has to be exchanged relatively frequently. The connection of the threaded ring with the housing in form of a threaded connection can in this case ensure a simple and fast exchangeability. A disadvantage of a threaded connection in a ground-drilling device can be however, that it is sensitive against contaminations, because a contaminated threaded connection can often no longer or only by using auxiliary means, be released again. In a preferred embodiment of the ground-drilling device according to the invention, the sealing ring can therefore be configured or integrated into the ground-drilling device so that it simultaneously seals the threaded connection between the threaded ring and the housing against the environment.
In order to facilitate the mounting and demounting of the ground-drilling device according to the invention, the threaded ring can be connected with the sealing element according to the invention, so that both elements can be inserted into the ground-drilling device as a unit or removed from the ground-drilling device again. This can occur in any desired manner. Preferably however, the sealing element insofar it is configured as sealing ring, is attached to the cylindrical projection of the threaded ring. By providing a projection of the (elastic) sealing ring and a corresponding recess in the cylindrical projection of the threaded ring, it can further be achieved that the projection of the sealing ring latchingly engages into the recess of the threaded ring and thus forms a form fitting connection between the two elements.
The sealing element of the ground-drilling device according to the invention can of course be configured multi-part.
BRIEF DESCRIPTION OF THE DRAWING
In the following, the invention is explained in more detail by way of an exemplary embodiment shown in the drawings.
In the drawings it is shown in:
FIG. 1 a section of a ground-drilling device according to the invention in a sectional side view; and
FIG. 2 in a perspective view individual elements of the ground-drilling device of FIG. 1 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows the front section of a ground-drilling device according to the invention in a sectional side view. In this section the ground-drilling device is essentially composed of a basic body 1 and a drill head 2 which is supported for movement relative to the basic body 1 . The basic body 1 includes a housing 3 in whose rear section an impact piston 4 is movably supported. The impact piston 4 is caused to move oscillatingly in a known manner by means of compressed air which is supplied to the ground-drilling device at the rear side end of the ground-drilling device via a compressed air line, wherein it impacts a front impact surface during operation of the ground-drilling device in each cycle in order to transfer the kinetic energy of the impact piston 4 in two stages first to the drill head 2 and then to the housing 1 of the ground-drilling device, to advance the ground-drilling device in the ground. The shown ground-drilling device is thus a ground rocket.
During its forward movement the impact piston 4 first impacts the rear end of the impact bolt 5 which is part of the drill head 2 and extends as far as into the working chamber 6 of the basic body 1 , in which the impact piston is movably supported.
The front end of the impact bolt 5 forms a drill head tip 7 which due to its relatively small diameter ensures a high directional stability of the ground rocket during movement through the ground. Behind the drill head tip 7 two ring shaped drill head elements 8 , 9 are connected behind one another to the impact bolt 5 . The connection occurs by means of two respective fastening bolts 10 .
The front drill head element 8 forms a plurality of cutting elements 11 which are oriented radially and whose radial extension substantially corresponds to the radius of the housing 3 and consequently to the radius of the bore to be generated. Between two neighboring cutting elements a respective channel is formed whose channel ground 12 —viewed from front to back—is configured inclined. During the advancement of the drill head 2 the cutting elements 11 cut into the ground and loosen the latter which is then disposed rearward through the channels which are formed between the cutting elements 11 . Due to the inclined geometry of the channel grounds 12 the ground is already displaced radially outward and compacted. This compaction is continued by the rear drill head element 9 whose sheath surface is configured conical in its front section and whose diameter widens to a diameter (viewed from front to back) which corresponds to the one of the housing 3 of the ground rocket.
In contrast to the step drill head known form the state of the art, the instant drill head which has a plurality of radially extending cutting elements 11 which already substantially correspond to the final diameter of the bore, allows achieving a particularly high directional stability of the ground rocket during its movement in the ground. Of course it is also possible to use the ground-drilling device according to the invention with any other drill head such as for example with a conventional step drill head.
The support of the impact bolt 5 in the basic body 1 is provided inter alia by the threaded ring 13 which is screwed into the front end of the housing 3 . For this, the threaded ring 13 has an outer threading and the housing has a corresponding inner threading. Adjoining the rear end of the threaded ring 13 is a threaded bushing 14 which also has an outer threading which engages in a corresponding inner threaded of the housing 3 . A ring shaped space is formed between the threaded bushing 14 and the corresponding section of the impact bolt 5 , in which space a cylindrical 15 is arranged. This helical spring 15 is supported on its front side on a projection of the threaded bushing 14 and on its rear side on a projection of the impact bolt 5 .
As soon as the impact piston 4 impacts the rear end of the impact bolt 5 the latter and the further elements of the drill head 2 connected thereto are displaced forward relative to the basic body 1 of the ground rocket. The cylindrical helical spring 15 is compressed by the movement of the impact bolt 5 relative to threaded bushing 14 , whereby a pre-tensioning is generated which later supports the return movement of the drill head 2 into its retracted basic position.
After a defined forward movement of the impact bolt 5 relative to the basic body 1 , a ring shaped shoulder 16 of the impact bolt 5 impacts the rear end of the threaded bushing 14 . In this way the kinetic energy remaining in the impact bolt 5 is also transferred to the basic body 1 of the ground rocket, so that the basic body 1 is then advanced in the ground together with the drill head 2 . The rear end of the threaded bushing 14 thus forms a front impact surface of the basic body 1 of the ground rocket.
After the energy which was transferred to the impact bolt 5 by a strike of the impact piston, is completely converted, the advancement of the ground rocket in the ground comes to a halt. Due to the pre-tensioning of the helical spring 15 , the still forwardly displaced drill head is retracted again into its starting position. At the same time the impact piston 4 is guided in a further cyclical movement, wherein the interplay is repeated when the impact piston impacts the rear end of the impact bolt again.
The forces which are transferred from the shoulder 16 of the impact bolt 5 to the threaded ring 13 are transferred to the housing 3 via the bolted connection with the housing. Because this represents a significant stress the threaded bushing 14 has to be secured to prevent that it is displaced from the desired position by the strikes. This securing of the threaded bushing 14 is achieved by the threaded ring 13 which is supported on the front end of the threaded bushing 14 via a spacer ring 17 .
As shown in FIG. 2 , the threaded ring 13 is slotted on one side in longitudinal axial direction, wherein the slot is configured conical on the end which faces the threaded bushing 14 . An expansion element 18 is inserted into the slot, which expansion element 18 has a threaded bolt 19 which can be screwed together with a threaded sleeve 20 . By screwing in of the threaded bolt 19 into the threaded sleeve 20 , a conical head part 21 of the expansion element is drawn into the corresponding conical section of the slot whereby the threaded ring 13 is spread out. In this way the area surface pressure of the bolted connection between the threaded ring 13 and the housing 3 is increased and thereby a secured fit of the threaded ring 13 and with this also of the threaded bushing 14 in the housing 3 is achieved.
On its front end the threaded ring 13 is provided with a cylindrical projection 22 , which serves for receiving a sealing ring 23 according to the invention. The sealing ring 23 is made of an elastic material (for example elastomer) and forms a projection 24 on its inner surface, which projection 24 can engage in a corresponding recess 25 of the cylindrical projection 22 of the threaded ring 13 .
This allows achieving a secure connection of the threaded ring 13 with the sealing ring 23 , so that the two components can be handled as a unit and in particular mounted into the ground rocket or demounted from the ground rocket. The sealing ring 23 further forms a through bore 26 which serves for receiving the threaded bushing 20 .
The movable support of the impact bolt 5 in the basic body 1 results in a connection between the working chamber 6 in which the impact piston 4 is movably guided and the free space 27 which is formed between the rear drill head element 9 and the impact bolt 5 (as parts of the drill head 2 ) and the sealing ring 23 , the threaded ring 13 and the spacer ring 17 (as parts of the basic body 1 ). To keep the ground rocket constructively as simple as possible, no sealing is provided which would securely prevent that the at times high overpressure (relative to the environment of the ground rocket) present in the working chamber 6 causes the pressurized air contained therein to overflow into the free space 27 . Consequently, an overpressure (relative to the environment of the ground rocket) is temporarily also generated in the free space 27 , which has to be compensated again relatively quickly because this overpressure would otherwise impede the return movement of the drill head 2 which is supported by the helical spring 15 . This pressure compensation is achieved in that between the rear drill head element 9 and the sealing ring 13 an annular gap 28 is formed via which the pressure compensation between the free space 27 and the environment can occur.
This annular gap 28 has the disadvantage however, that the contaminations (in particular soil and water) can enter into the free space 27 from the environment, whereby at least the wear of the movable parts is increased and the mobility of these parts can be impeded. The risk of an entering of contaminations is particularly given because the free space is temporarily quickly increased by the forward movement of the drill head, whereby (temporarily) a negative pressure (relative to the environment) is generated. This negative pressure can cause contaminations to be aspirated through the annular gap.
To prevent this, the sealing ring 23 is provided with a sealing lip 29 which is configured so as to point slantedly rearward. Due to the particular configuration of the sealing lip 29 the latter can be deformed in case of an overpressure in the free space 27 , whereby it can descent into a ring shaped recess 30 of the sealing ring 23 which recess is located adjacent to the sealing lip 29 . This releases the annular gap 28 . When, on the other hand a negative pressure relative to the environment is present in the free space 27 this negative pressure leads to the sealing lip 29 being pressed against the inner surface which is formed by the rear drill head element 9 and the annular gap 28 being closed.
The sealing ring 23 further has two small opposing ventilation openings 32 which in conjunction with two flat portions 33 in a front shoulder of the cylindrical projection 22 form a connection between the free space 27 and the environment. Through these ventilation openings 32 a flow of pressurized gas can occur from the free space into the environment when an overpressure is present in the free space. At the same time however, an aspiration of contaminations is largely prevented when a negative pressure is present in the free space 27 because the ventilation openings 32 on one hand only have a relatively small diameter and on the other hand are arranged in the sealing ring 23 or integrated into the ground-drilling device so that an air flow from the environment into the free space 27 is deflected multiple times (compare FIG. 1 ) before the air flow enters the free space 27 . This deflection prevents that contaminations enter as far as into the free space due to their inertia.
In the mounted state of the sealing ring 23 , the ventilation openings 32 lead into the gap which is formed between the sealing ring 23 and the rear drill head element 9 and with this—viewed from the environment—before the sealing lip 29 . The compressed air which temporarily exits the ventilation openings 32 can prevent that contaminations accumulate at the side of the sealing lip 29 which faces the gap, which may impede the function of the sealing lip 29 after a longer use of the ground-drilling device.
The sealing ring 23 additionally has a ring shaped sealing bulge 31 which partially rests against the front end of the housing 3 . This sealing bulge 31 prevents that contaminations enter the threaded connection between the threaded ring 13 and the housing 3 . This allows ensuring that the threaded connection can be released without great effort also after a longer use of the ground rocket.
|
A ground-drilling device includes a basic body and a drill head movably mounted in relation thereto in the longitudinally axial direction, wherein a free space, which is variable in its size owing to the movable mounting, is formed between the drill head and the basic body, and a sealing element for sealing the free space with respect to the environment, wherein the sealing element is designed as a valve element which opens when an overpressure is present inside the clearance, in order to produce a pressure compensation, and which is closed when a negative pressure is present inside the clearance, in order to prevent a pressure compensation.
| 4
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a speakerphone that estimates an echo canceling performance of an echo canceler through an easy processing and improves the transmit and receive switching performance of the voice switch, in a full-duplex communication system using a speaker and microphone.
2. Description of the Related Art
The speakerphone used for a telephone conversation using a speaker and microphone without using a handset has been applied widely to a teleconference system that connects plural locations, and to the automobile telephone system wherein the driver cannot free his hands from the steering for obvious safety reasons.
However, this speakerphone involves troublesome phenomena, such as an acoustic echo generated by sounds emitted from the speaker returning to the microphone while reflecting, and a line echo generated by a talker's uttered voice being reflected at the connections on the communication line due to the impedance mismatching thereat. FIG. 6 is a chart for simply explaining the acoustic echo and the line echo.
What makes the problem acute is that the acoustic echo path and the line echo path coincide so as to make up a closed loop (formed of a microphone 61 , communication line SP, and speaker 62 ), as shown in FIG. 6 . If the gain of the foregoing dosed loop exceeds 1, it will generate an oscillation (howling) inside the closed loop, which will in the worst case disable the conversation. Even if the howling does not occur, if there is a line echo, the talker's uttered voice will be emitted from the speaker 62 with a delay, and hence, the talker will be in a trouble of speaking.
Devices have been provided in order to avoid the influence of these echoes, which can be classified roughly into two. One of them is a half duplex voice switching system, wherein, when a near-end talker is speaking, an electric loss is inserted on the receive path of the talker (transmit state), when the talker is listening to, an electric loss is inserted on the transmit path of the talker (receive state). In this system, the switching of the transmit and the receive state is carried out on the basis of the voices uttered by the near-end talker or the far-end talker.
The other one is an echo canceling system, wherein an adaptive filter to estimate the characteristic of the foregoing echo is employed to produce a signal similar to the echo, and the signal is subtracted from the transmit and the receive paths to thereby remove the echo signal from the dosed loop. In the echo canceling system, echoes are removed in real time, both the transmit and receive paths are not closed, and hence, the full duplex communication is possible.
The technique relating to the speakerphone using the foregoing voice switch is disclosed, for example, in the Japanese Patent Application Laid-open No. 5-44221. FIG. 7 is a functional block representation of the speakerphone disclosed in the foregoing document.
As shown in FIG. 7, a speakerphone 100 using the voice switch comprises a transmit section 200 , a receive section 300 , and a computer 110 . The transmit section 200 includes a multiplexer 210 for temporarily storing a plurality of input signals such as speech signals inputted from a microphone 111 , a mute control 211 to dose the transmit path in accordance with a control signal from the computer 110 described later, a high pass filter 212 for removing background noises contained in the foregoing speech signals, a programmable attenuator 213 (equivalent to receive state setting means) for giving attenuation to the foregoing speech signals passed through the high pass filter 212 in accordance with a control signal from the computer 110 , an envelope detector 214 for detecting an envelope of a speech signal outputted from the high pass filter 212 , a low pass filter 215 for reducing switching noises generated by the programmable attenuator 213 and shaping output waveforms to a communication line 101 , and a logarithmic amplifier 216 for logarithmically amplifying an output from the envelope detector 214 .
The receive section 300 contains functionally the same circuits as the transmit section 200 : a multiplexer 310 for temporarily storing a plurality of input signals such as speech signals received through a communication line 102 , a mute control 311 to dose the receive path in accordance with a control signal from the computer 110 , a high pass filter 312 for removing background noises contained in the foregoing speech signals, a programmable attenuator 313 (equivalent to transmit state setting means) for giving attenuation to the foregoing speech signals passed through the high pass filter 312 in accordance with a control signal from the computer 110 , an envelope detector 314 for detecting an envelope of a speech signal outputted from the high pass filter 312 , a low pass filter 315 for reducing switching noises generated by the programmable attenuator 313 and shaping output waveforms to a speaker 112 , and a logarithmic amplifier 216 for logarithmically amplifying an output from the envelope detector 314 .
And, the foregoing computer 110 (equivalent to state switching means) receives signals from the logarithmic amplifiers 216 , 316 through a multiplexer 117 and an A/D converter 115 , and controls the mute controls 211 , 311 and the programmable attenuators 213 , 313 . Further, the computer 110 is connected to a calibration circuit 113 as well. The calibration circuit 113 feeds a specific calibration tone to the multiplexers 210 and 310 to assist the estimation of system characteristics.
The operation of the foregoing speakerphone, specially a transmit break-in operation switching from the receive state to the transmit state will hereunder be described. FIG. 8 is a flow chart for explaining the transmit break-in operation.
As shown in FIG. 8, when the process comes into step 1001 , the speakerphone enters the receive state. Then, the process advances to step 1002 where a determination is made as to whether a transmit signal TX-S inputted from the microphone 111 exceeds an expected transmit signal IX-E by a specific threshold Th. Here, the expected transmit signal TX-E is a transmit signal expected to be generated by the coupling of the receive signal RX-S from the speaker 112 to the microphone 111 . The reason to provide this step 1002 is to prevent a phenomenon that the device generates the self-switching by the receive signal RX-S emitted from the speaker 112 and the influence of an acoustic echo, while the near-end talker does not speak.
At step 1002 , if the transmit signal TX-S exceeds the expected transmit signal TX-E, the process advances to step 1003 where a determination is made as to whether the transmit signal TX-S exceeds a transmit noise TX-N by a specific threshold Th. The decision at this step is provided to determine whether the transmit signal TX-S is a voice signal or a noise signal.
At step 1003 , after the transmit signal TX-S is confirmed as a voice signal, the process advances to step 1004 where a comparison is made whether the transmit signal TX-S exceeds the receive signal RX-S by a specific threshold Th. And, if the transmit signal TX-S is greater than the receive signal RX-S at step 1004 , the process moves to step 1005 where the holdover timer is initialized, and then the process moves to step 1006 where it brings the device into the transmit state.
Thus, the foregoing speakerphone prevents an error switching due to the acoustic echo by comparing the transmit signal TX-S with the expected transmit signal TX-E. To prevent the error switching due to the line echo is performed substantially in the same manner as in the acoustic echo, and the description will be omitted
Incidentally, the threshold used in the foregoing expected transmit signal TX-E and the decision at step 1004 is determined by using a calibration tone actually outputted from the calibration circuit 113 . More concretely, the calibration circuit 113 generates a audio frequency signal covering from 300 Hz to 3.4 kHz, and the speaker emits the audible sounds into the environment in a regular manner. On the basis of the acoustic response characteristics then measured, the maximum amplitude of the acoustic echo and the duration of reverberation, etc., are obtained. Thereby, the foregoing expected transmit signal TX-E and the threshold are determined. The calibration tone is transmitted while the speech signal is not detected on the transmit path and the receive path so as to vary the expected transmit signal TX-E and/or the threshold in correspondence with the change of the environment.
Accordingly, when the environment produces less reverberation and the acoustic condition is good, or when the line condition is good, it is possible to perform a communication that approaches to the fill duplex system by lowering the break-in threshold determined in accordance with the acoustic echo or the line echo.
On the other hand, the technique relating to the echo canceler is disclosed, for example, in the Japanese Patent Application Laid-open No. 61-258554. FIG. 9 illustrates a block diagram of the echo canceler disclosed in the foregoing document.
As shown in FIG. 9, the echo canceler includes: an XR memory 906 for storing in time series a receive signal XR received from the communication line, an A memory 907 for storing an estimated value A of the acoustic echo returning to the microphone 901 from a speaker 902 while reflecting, an arithmetic circuit 908 for operating the convolution of the receive signal XR and the estimated value A, a subtracter 909 for subtracting the output of the arithmetic circuit 908 from the acoustic echo signal to thereby suppress the acoustic echo signal, an XT memory 910 for storing in time series a transmit signal XT, an H memory 911 for storing an estimated value H of the line echo, an arithmetic circuit 912 for operating the convolution of the transmit signal XT and the estimated value H, a subtracter 913 for subtracting the output of the arithmetic circuit 912 from the line echo signal to thereby suppress the line echo signal, an adaptive control circuit 914 for acquiring an adjusting coefficient that sequentially adjusts the estimated value A stored in the A memory 907 on the basis of the receive signal XR stored in the XR memory 906 and the output of the subtracter 909 , and the same for acquiring an adjusting coefficient that sequentially adjusts the estimated value H stored in the H memory 911 on the basis of the transmit signal XT stored in the XT memory 910 and the output of the subtracter 913 , an adder 915 for sequentially adjusting the estimated value A by adding the adjusting coefficient acquired by the adaptive control circuit 914 , an adder 916 for sequentially adjusting the estimated value H by adding the adjusting coefficient acquired by the adaptive control circuit 914 , switches 917 , 918 , 919 for selecting the input/output signals of the adaptive control circuit 914 , and a signal detector 920 (equivalent to speech signal detection means) for detecting the speech signal of the transmit signal and the receive signal and controlling the switches 917 , 918 , 919 .
Although an echo canceler is usually provided with the adaptive control circuit for removing the acoustic echo and the adaptive control circuit for removing the line echo separately, the foregoing echo canceler, having a single adaptive control circuit 914 , performs the processings usually done by the foregoing two adaptive control circuits with the assistance of the signal detector 920 and the switches 917 , 918 , 919 to control the input/output; and thereby achieves to simplify the hardware construction. Here, the process of removing the acoustic echo is basically the same as that of removing the line echo, and hence, the removal of the acoustic echo will mainly be referred to hereunder, and the removal of the line echo will be omitted as long as not needed.
In the foregoing echo canceler, when the signal detector 920 detects a speech signal only in the receive signal XR, the echo canceler starts the adaptive learning. In other words, the adjusting coefficient Δ a n acquired by the adaptive control circuit 914 sequentially modifies the estimated value sequence a n of the impulse response, stored in the A memory 907 . This adjustment employs, for example, the method of identification by learning. The following equation (1) expresses concretely the adjustment by the method of identification by learning. a n = a n - 1 + Δ a n - 1 = a n - 1 + α ( Y R n - 1 - a n - 1 · X R n - 1 ′ ) X R n - 1 X R n - 1 · X R n - 1 ′ = a n - 1 + α ( Y R n - 1 - ∑ k = 0 N - 1 a n - 1 , k · X R n - k - 1 ) X R n - 1 ∑ j = 1 N X R n - 1 2 [ equation 1 ]
here, a: loop gain, N: degree of the adaptive filter, YR n−1 : acoustic echo signal at time n−1.
Further, the foregoing adaptive learning is performed when the speech signal is detected only in the receive signal, and the reason is as follows. Since the speech signal uttered by the near-end talker is originally independent on the acoustic echo characteristics, if the speech signal uttered by the near-end talker together with the acoustic echo signal is inputted to the echo canceler, the speech signal uttered by the near-end talker functions as disturbances so as to obstruct the learning of the echo canceler.
Thus, the speakerphone containing the foregoing echo canceler is able to remove the echo in a better accuracy along with the time progress, by sequentially adjusting the impulse response of the adaptive filter, using the method of identification by learning.
Incidentally, the combination of the foregoing voice switching system and the echo canceling system will attenuate the echo by the attenuator of the voice switch as well as remove the echo to some extent by the adaptive filter of the echo canceler. Therefore, the combination has a possibility to provide a system that approaches to the full duplex system and is more immune from influence by the echoes.
The problem here lies in the setting of the threshold for switching the transmit state and the receive state in the voice switching system. The voice switching system is able to directly measure the characteristics of the system by the calibration tone generated from the calibration circuit 113 and to adjust the threshold to the echo. However, if combined with the echo canceling system, the amount of the echo varies from moment to moment which remains in the system in correspondence with the degree of learning by the adaptive filter. Therefore, the threshold calibrated only within a specific period will cause most calibrations to result in wastes, and will cause error switching as well.
The present invention intends to solve the problems in these conventional techniques and to improve the speakerphone, and it is therefore an object of the invention to provide a speakerphone combining the voice switching system and the echo canceling system, which stably performs a communication that approaches to the full duplex while estimating a performance variation of the adaptive filter on the basis of the past signal referred to when the adaptive filter performs the learning.
SUMMARY OF THE INVENTION
In order to achieve the foregoing object, the speakerphone according to the first invention comprises: receive state setting means for setting a receive state to attenuate a transmit signal inputted from a microphone before transmitting the transmit signal into a communication line; transmit state setting means for setting a transmit state to attenuate a receive signal received from the communication line before outputting the receive signal from a speaker; state switching means for determining a state and setting the determined state, said state switching means comprising means for comparing the difference between the transmit signal and the receive signal with an acoustic echo threshold set to an acoustic echo generated by the receive signal returning to the microphone from the speaker; speech signal detection means for detecting a speech signal from the transmit signal and the receive signal; acoustic echo canceling means, including an adaptive filter for sequentially estimating the characteristics of the acoustic echo by varying the response on the basis of the acoustic echo when the speech signal detection means detects the speech signal only in the receive signal, for subtracting a quasi-acoustic echo signal obtained by inputting the receive signal to the adaptive filter from the transmit signal; residual acoustic echo estimation means for estimating a residual acoustic echo signal remaining without being removed by the acoustic echo canceling means on the basis of the history of the receive signal outputted in the past from the speaker; and acoustic echo threshold variation means for varying the acoustic echo threshold of the state switching means in accordance with the residual acoustic echo signal estimated by the residual acoustic echo estimation means.
The speakerphone relating to the foregoing first invention is able to estimate the residual acoustic echo signal on the basic of the receive signal emitted in the past from the speaker, and to vary the acoustic echo threshold for switching the transmit state and receive state in correspondence with the estimated residual acoustic echo signal. Therefore, putting the acoustic echo canceling means and the transmit/receive state setting means into cooperation, the speakerphone is able to achieve a full-duplex communication system, which improves in the transmit/receive switching performance and presents a better feeling of operation compared to the conventional speakerphone.
In the foregoing speakerphone, the residual acoustic echo signal can be estimated, for example, on the basis of the integrated value of power of the receive signal obtained by integrating the power of the receive signal when the foregoing speech signal detection means detects the speech signal only in the receive signal. And, the residual acoustic echo signal can be estimated on the basis of the integrated value of the receive signal detected obtained by integrating the detected time of the receive signal when the foregoing speech signal detection means detects the speech signal only in the receive signal. A simple process such as the integration of power of the receive signal or the integration of time of the receive signal detected will reduce the quantity of the arithmetic operation for varying the acoustic echo threshold, which provides a speakerphone system that is inexpensive and consumes a less power compared to the conventional.
Further, in the foregoing speakerphone, the state switching means maintains the receive state or the transmit state when the speech signal detection means detects the speech signal from the receive signal or the transmit signal, and shifts the attenuation in the receive state setting means and the transmit state setting means into an intermediate attenuation when the speech signal detection means does not detect a speech signal.
Accordingly, in such a circumstance that there is not a great level difference between the receive signal and the transmit signal, for example, while receiving a speech signal from a far-end talker, the talker lapses into silence for a while, the speakerphone with this arrangement is able to return to the receive state immediately when the far-end talker resumes speaking, and to avoid an initial sound from being cut out as is the case with the conventional speakerphone, since this arrangement will not change the processing procedure while maintaining the receive state and only shifting the attenuation in the receive state and transmit state setting means into an intermediate attenuation.
Further, the speakerphone according to the second invention comprises: receive state setting means for setting a receive state to attenuate a transmit signal inputted from a microphone before transmitting the transmit signal into a communication line; transmit state setting means for setting a transmit state to attenuate a receive signal received from the communication line before outputting the receive signal from a speaker; state switching means for determining a state and setting the determined state, said state switching means comprising means for comparing the difference between the transmit signal and the receive signal with a line echo threshold set to a line echo generated by the transmit signal returning to a line receive side from a line transmit side; speech signal detection means for detecting a speech signal from the transmit signal and the receive signal; line echo canceling means, including an adaptive filter for sequentially estimating the characteristics of the line echo by varying the response on the basis of the line echo when the speech signal detection means detects the speech signal only in the transmit signal, for subtracting a quasi-line echo signal obtained by inputting the transmit signal to the adaptive filter from the receive signal; residual line echo estimation means for estimating a residual line echo signal remaining without being removed by the line echo canceling means on the basis of the history of the transmit signal outputted in the past from the microphone to the line; and line echo threshold variation means for varying the line echo threshold of the state switching means in accordance with the residual line echo signal estimated by the residual line echo estimation means.
The speakerphone relating to the foregoing second invention is able to estimate the residual line echo signal on the basis of the transmit it signal outputted in the past from the microphone to the line, and to vary the line echo threshold for switching the transmit state and receive state in correspondence with the estimated residual line echo signal. Therefore, putting the line echo canceling means and the transmit/receive state setting means into cooperation, the speakerphone is able to achieve a full-duplex communication system, which improves in the transmit/receive switching performance and presents a better feeling of operation compared to the conventional speakerphone.
In the foregoing speakerphone, the residual line echo signal can be estimated, for example, on the basis of the integrated value of power of the transmit signal obtained by integrating the power of the transmit signal when the foregoing speech signal detection means detects the speech signal only in the transmit signal. And, the residual line echo signal can be estimated on the basis of the integrated value of the transmit signal detected obtained by integrating the detected time of the transmit signal when the foregoing speech signal detection means detects the speech signal only in the transmit signal. A simple process such as the integration of power of the transmit signal or the integration of a detected time of the transmit signal will reduce the quantity of the arithmetic operation for varying the line echo threshold, which provides a speakerphone system that is inexpensive and consumes a less power compared to the conventional.
Further, in the foregoing speakerphone, the state switching means maintains the transmit state or the receive state when the speech signal detection means detects the speech signal from the transmit signal or the receive signal, and shifts the attenuation in the receive state setting means and the transmit state setting means into an intermediate attenuation when the speech signal detection means does not detect a speech signal.
Accordingly, in such a circumstance that there is not a great level difference between the transmit signal and the receive signal, for example, a near-end talker lapses into silence for a while during communication, the speakerphone with this arrangement is able to return to the transmit state immediately when the near-end talker resumes speaking to detect the speech signal, and to avoid an initial sound from being cut out as is the case with the conventional speakerphone, since this arrangement will not change the processing procedure while maintaining the transmit state and only g the attenuation in the transmit state and receive state setting means into an intermediate attenuation.
Further, the speakerphone according to the third invention is a combination of the first and the second invention. The third invention is able to reduce the effect of both an acoustic echo and a line echo and realize the smoother switching of the state.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a block diagram of a speakerphone relating to one embodiment of the present invention;
FIG. 2 is a flow chart for explaining the operation of the foregoing speakerphone;
FIG. 3 is a graph showing the variation of the characteristics of an echo canceler in time series;
FIG. 4 is a graph for explaining the estimation of the characteristic variation by the integrated value of an input signal power;
FIG. 5 is a graph for explaining the estimation of the characteristic variation by the integrated value of time for detecting a speech signal;
FIG. 6 is a chart for simply explaining the echo phenomenon;
FIG. 7 is a block diagram of a conventional speakerphone of the voice switching system;
FIG. 8 is a flow chart for explaining the operation of the foregoing conventional speakerphone; and
FIG. 9 is a block diagram of a speakerphone provided with the conventional echo canceler.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of the present invention will hereafter be described in detail with reference to the accompanying drawings. The embodiment described hereunder represents only one example that materializes the invention, and does not confine the scope of the invention in a technological sense. Here, FIG. 1 illustrates a block diagram of a speakerphone relating to the one embodiment of the invention, FIG. 2 illustrates a flow chart for explaining the operation of the foregoing speakerphone, FIG. 3 graphs the variation of the characteristics of an echo canceler in time series, and FIG. 4 graphs in time series the state of adjusting the threshold by using the signal power.
As shown in FIG. 1, the speakerphone is classified into three sections: a voice switch section VS, an echo canceler section, and an echo threshold varying section.
The voice switch section VS includes: receive state setting means 2 for setting a receive state to attenuate a transmit signal TS inputted from a microphone 1 before transmitting the transmit signal TS to a general communication line SP connected, for example, to the two-wire/four-wire transducer; transmit state setting means 4 for setting a transmit state to attenuate a receive signal RS received from the line SP before outputting the receive signal RS to a speaker 3 ; a signal level detector 5 for detecting the signal level of the transmit signal TS and the receive signal RS; line echo transmit/receive determination means 6 which compares the receive signal RS with the transmit signal TS on the basis of a specific line echo threshold GRS set to the line echo generated by the transmit signal TS returning to a line receive side 21 from a line transmit side 20 ; acoustic echo transmit/receive determination means 7 which compares the transmit signal TS with the receive signal RS on the basis of a specific acoustic echo threshold GTS set to the acoustic echo generated by the receive signal RS returning to the microphone 1 from the speaker 3 ; speech signal detection means 8 for detecting a speech signal from the transmit signal TS and the receive signal RS; first transmit/receive state switching means 9 (equivalent to a state switching means) that sets, in the transmit preference mode, when the line echo transmit/receive determination means 6 determines that the transmit signal TS is greater or smaller than the receive signal RS, the transmit state or the receive state by means of the transmit state setting means 4 or the receive state setting means 2 , maintains the transmit state or the receive state when the speech signal detection means 8 detects the speech signal from the transmit signal TS or the receive signal RS, and shifts the attenuation in the receive state setting means 2 and the transmit state setting means 4 into an intermediate attenuation when the speech signal detection means 8 detects noise signals; second transmit/receive state switching means 10 (equivalent to a state switching means) that sets, in the receive preference mode, when the acoustic echo transmit receive determination means 7 determines that the receive signal RS is greater or smaller than the transmit signal TS, the receive state or the transmit state by means of the receive state setting means 2 or the transmit state setting means 4 , maintains the receive state or the transmit state when the speech signal detection means 8 detects the speech signal from the receive signal RS or the transmit signal TS, and shifts the attenuation in the receive state setting means 2 and the transmit state setting means 4 into an intermediate attenuation when the speech signal detection means 8 detects noise signals; process transfer means 11 transfers, when the first transmit/receive state switching means 9 sets the receive state or the intermediate state by the line echo transmit/receive determination means 6 determining the transmit signal TS to be smaller than the receive signal RS, the next process to the second transmit or the receive state switching means 10 , and transfers, when the second transmit/receive state switching means 10 sets the transmit state or the intermediate state of the attenuation by the acoustic echo transmit/receive determination means 7 determining the receive signal RS to be smaller than the transmit signal TS, the next process to the first transmit/receive state switching means 9 ; and transmit/receive signal determination means 18 for determining the presence of the transmit signal TS or the receive signal RS after removing the influence by the system gain on the basis of the predetermined transmit path gain Gt and receive path gain Gr. The line echo threshold and the acoustic echo threshold can be varied by line echo threshold variation means 17 and acoustic echo threshold variation means 15 , which will be described later.
The echo canceler section includes adaptive filters 12 ( 12 a , 12 b ) for sequentially estimating the characteristics of the acoustic echo or the line echo by varying the response on the basis of the acoustic echo or the line echo when the speech signal detection means 8 detects the speech signal only in the receive signal RS or the transmit signal TS, and an acoustic echo canceler 13 a and a line echo canceler 13 b for subtracting a quasi-acoustic signal or a line echo signal obtained by inputting the receive signal RS or the transmit signal TS to the adaptive filter 12 a or 12 b from the transmit signal TS or the receive signal RS.
And, the speakerphone further comprises the echo threshold varying section in order to cooperate the echo canceler section with the voice switch section VS, which includes: residual acoustic echo estimation means 14 for estimating a residual acoustic echo signal remaining without being removed by the acoustic echo canceler 13 a on the basis of the history of the receive signal RS outputted from the speaker; acoustic echo threshold variation means 15 for varying the acoustic echo threshold GTS of the acoustic echo transmit/receive determination means 7 in accordance with the residual acoustic echo signal estimated by the residual acoustic echo estimation means 14 ; residual line echo estimation means 16 for estimating a residual line echo signal remaining without being removed by the line echo canceler 13 b on the basis of the history of the transmit signal TS outputted from the microphone to the line; line echo threshold variation means 17 for varying the line echo threshold GRS of the line echo transmit/receive determination means 6 in accordance with the residual line echo signal estimated by the residual line echo estimation means 16 .
Here in the embodiment, the transmit state is defined as a state that the attenuation of the receive state setting means 2 is 0 and the attenuation of the transmit state setting means 4 is the maximum value, the transmit waiting state is defined as a state that the attenuation of the receive state setting means 2 is half of the maximum value and the attenuation of the transmit state setting means 4 is half of the maximum value, the receive state is defined as a state that the attenuation of the receive state setting means 2 is the maximum value and the attenuation of the transmit state setting means 4 is 0, and the receive waiting state is defined as a state that the attenuation of the receive state setting means 2 is half of the maximum value and the attenuation of the transmit state setting means 4 is half of the maximum value. Further, the combination of the transmit state and the transmit waiting state is referred to as the transmit preference state, and the combination of the receive state and the receive waiting state is referred to as the receive preference state.
In the foregoing speakerphone, the line echo threshold GRS and the acoustic echo threshold GTS that the line echo transmit receive determination means 6 and the acoustic echo transmit/receive determination means 7 each refer to are the estimated values of the line echo and the acoustic echo, which are preset, for example, within 0˜48 dB on factory shipment. Gt and Gr in FIG. 1 indicate the transmit path gain and the receive path gain, respectively, that are used for the determination of the transmit/receive signal determination means 18 , which are preset, for example, within 0˜48 dB on factory shipment, in the same manner as the line echo threshold GRS and the acoustic echo threshold GTS. Further, Tt and Tr are the thresholds for determining the presence of the transmit speech signal and the receive speech signal, which are preset, for example, within 0˜48 dB on factory shipment in consideration of the noise level contained in the transmit signal TS.
The switching operation of the transmit state and the receive state and the variation of the threshold in the foregoing speakerphone will now be described with reference to FIG. 2 . Further, the transmit state, receive state, transmit waiting state, and receive waiting state are defined in the same manner as the above.
When the speakerphone is powered and connected to the general communication line, the speakerphone is usually set to the receive preference state. However here, the switching operation in the transmit preference state, namely, the operation of the first transmit/receive state switching means 9 will be described first.
At step S 101 , the state setting is confirmed in the first transmit/receive state switching means 9 .
Next, the process moves to step S 102 where the line echo transmit/receive determination means 6 compares the level of the transmit signal TS and the receive signal RS on the basis of the line echo threshold GRS to determine the state. If the transmit signal TS is grater than the receive signal RS from which the value of GRS is subtracted, the process advances to step S 103 , if the transmit signal TS is smaller than the receive signal RS, the process advances to step S 104 . Incidentally, the step S 102 indicates that it continues the transmit preference process unless the voice signal level of a far-end talker clearly exceeds the line echo. Thus, the voice switch section VS continues the transmit preference process, even if a near-end talker speaks nothing for a while at the transmit preference state.
At step S 103 , the process sets again a flag for the transmit preference state, and the process advances to step 105 where the speech signal detection means 8 detects the speech signal of the transmit signal TS. Here, the speech signal detection means 8 detects the speech signal if the transmit signal is greater than the noise signal threshold, and detects the noise signal if it is smaller than the noise signal threshold.
At step S 105 , if the process determines that the transmit signal TS is a speech signal, the process advances to step S 106 where it sets the receive state setting means 2 and the transmit state setting means 4 to the transmit state. Further, if the speech signal is detected only in the transmit signal TS by the decision at step S 102 and step S 105 , the process advances to step S 107 where the residual line echo estimation means 16 estimates the residual line echo signal remaining without being removed by the line echo canceler 13 b.
Here, the performance of the adaptive filters 12 ( 12 a , 12 b ) used in the echo canceler section can virtually be estimated by the characteristics of the input signal referred in the adaptive learning of the adaptive filters 12 , which will be explained with reference to FIG. 3 and 4. FIG. 3 illustrates the state that the residual line echo signal decreases as the time progresses.
On the other hand, FIG. 4 ( a ) illustrates the signal power of the input signal that the adaptive filters 12 referred on the adaptive learning, and FIG. 4 ( b ) illustrates the integrated signal power of the transmit signal TS.
From FIGS. 3 and 4 ( b ), it can be understood that the degree of the learning of the adaptive filters 12 increases as the integrated power of the input signal referred increases. This input signal is only needed to use, for example, the transmit signal when the speech signal is detected only in the transmit signal TS, which does not require special measuring means.
Accordingly, the residual line echo estimation means 16 applies an operation of which output decreases as the integrated power of the input signal (transmit signal TS in this case) increases. FIG. 4 ( c ) illustrates the output of the operation against time. The actual value of the residual line echo shown in FIG. 3 and the estimated value of the residual line echo shown in FIG. 4 ( c ) are consistent in tendency, and the estimated value of the residual line echo is enough to be used for varying the line echo threshold.
And, the process advances to step S 108 where the line echo threshold variation means 17 varies the line echo threshold GRS as shown in FIG. 4 ( d ), in correspondence with the residual line echo signal estimated by the residual line echo estimation means 16 .
In this manner, based on the past input signal that the adaptive filters 12 referred during learning, the performance variation of the echo canceler can easily be estimated. Further, a special measurement means for carrying out the calibration is not needed for this estimation.
Further, if the process determines that the transmit signal TS is a noise signal at step S 105 , the process advances to step S 109 where it sets the receive state setting means 2 and the transmit state setting means 4 to the intermediate states. After completing the processes at step S 106 and step S 109 , the process returns to step S 101 to continue the decision process.
On the other hand, if the process determines that the transmit signal TS is smaller than the receive signal RS from which the value of GRS is subtracted at step S 102 , the process moves to step S 104 where the transmit/receive signal determination means 18 compares the transmit signal TS and the receive signal RS on the basis of the transmit path gain Gt and the receive path gain Gr. At this step S 104 , the possibility of the receive is examined with the system gain removed. At step S 104 , if the level of the transmit signal TS is determined greater than the receive signal RS, the process returns to step S 103 where it sets the flag for the transmit preference state, and at the next step S 105 , it examines the presence of the transmit speech signal. And, if the level of the receive signal RS is determined greater than the transmit signal TS, the process progresses to step S 110 where it sets the flag for the receive preference state, and at the next step S 111 , it examines the presence of the receive speech signal.
At step S 111 the speech signal detection means 8 detects the speech signal of the receive signal RS. The determination of the speech signal detection means 8 is carried out, in the same manner as the transmit signal TS, on the basis that the receive signal RS is greater or smaller than the noise signal threshold.
At step S 111 , if the process determines that the receive signal RS is a speech signal, the process advances to step S 112 where it sets the receive signal setting means 2 and the transmit signal setting means 4 to the receive state. Further, in the same manner as in the variation of the line echo threshold, the acoustic echo is estimated at step S 113 and varied at step S 114 . And, if the process determines that the transmit signal TS is a noise signal at step S 111 , the process advances to step S 115 where it sets the receive state setting means 2 and the transmit state setting means 4 to the intermediate states.
After completing the processes at step S 112 and step S 115 , the process returns to step S 101 to continue the decision process. When returning to step S 101 , the process at step S 108 or S 114 sets the line echo or the acoustic echo threshold to a low level to accompany with the performance improvement of the echo canceler. Accordingly, the speakerphone is able to perform a communication that approaches to the full duplex by the voice switch section VS.
If the decision process in the foregoing first transmit/receive state switching means 9 sets the flag for the receive preference, the process transfer means 11 transfers the decision process from the first transmit/receive state switching means 9 to the second transmit/receive state switching means 10 . Here, the decision processes by the first transmit/receive state switching means 9 and the second transmit/receive state switching means 10 are in a pair relation, which are substantially equivalent.
If the state transfers from the transmit preference to the receive preference, for example, by a voice uttered by a far-end talker, first, the process moves to step S 202 where the acoustic echo transmit/receive determination means 7 compares the receive signal RS with the transmit signal TS on the basis of the acoustic echo threshold GTS. If the receive signal RS is determined to be grater than the transmit signal TS from which the value of GTS is subtracted, the process advances to step S 203 , if the receive signal RS is determined to be smaller, the process advances to step S 204 . Incidentally, the step S 202 indicates that it continues the receive preference process unless the voice signal level of a near-end talker clearly exceeds the acoustic echo. Thus, the speakerphone continues the receive preference process, even if a far-end talker speaks nothing for a while at the receive preference state.
At step S 203 , the process sets again a flag for the receive preference state. At this step S 203 , if the process continues, the second transmit/receive state switching means 10 is designed to perform the decision process.
Next, the process advances to step 205 where the speech signal detection means 8 determines whether the receive signal RS is a speech signal. And, at step S 205 , if the process determines that the receive signal RS is a speech signal, the process advances to step S 206 where it sets the receive state setting means 2 and the transmit state setting means 4 to the receive state. And, in the same manner as the foregoing steps (S 113 , S 114 ), the variation of the acoustic echo threshold is carried out through step S 207 and Step 208 . Further, if the process determines that the receive signal RS is a noise signal at step S 205 , the process advances to step S 209 where it sets the receive state setting means 2 and the transmit state setting means 4 to the intermediate states.
After completing the state setting processes at step S 206 and step S 209 , the process returns to step S 101 to continue the process.
On the other hand, if the process determines that the receive signal RS is smaller than the transmit signal TS from which the value of GTS is subtracted at step S 202 , the process moves to step S 204 where the transmit/receive signal determination means 18 compares the transmit signal TS and the receive signal RS on the basis of the transmit path gain Gt and the receive path gain Gr. At this step S 204 , the possibility of the transmit is examined with the system gain removed. At step S 204 , if the level of the receive signal RS is determined greater than the transmit signal TS, the process returns to step S 203 where it sets the flag for the receive preference state, and at the next step S 205 , it examines the presence of the receive speech signal. And, if the level of the transmit signal TS is determined greater than the receive signal RS at step S 204 , the process progresses to step S 210 where it switches from the flag for the receive preference state to the flag for the transmit preference state, and at the next step S 211 , it examines the presence of the transmit speech signal. Further, at step S 210 , the next decision process is designed to move to the first transmit/receive state switching means 9 .
At step S 211 , the speech signal detection means 8 determines whether the transmit signal TS is a speech signal or a noise signal.
If the process determines that the transmit signal TS is a speech signal at step S 211 , the process advances to step S 212 where it sets the receive signal setting means 2 and the transmit signal setting means 4 to the transmit state. Further, in the same manner as in the variation of the line echo threshold, the acoustic echo is estimated at step S 213 and varied at step S 214 . And, if the process determines that the transmit signal TS is a noise signal at step S 211 , the process advances to step S 215 where it sets the receive state setting means 2 and the transmit state setting means 4 to the intermediate states.
After completing the state setting processes at step S 212 and step S 215 , the process returns to step S 101 to continue the decision process. When returning to step S 101 , the process at step S 208 or S 214 sets the line echo threshold or the acoustic echo threshold to a low level to accompany with the performance improvement of the echo canceler. Accordingly, the speakerphone is able to perform a communication that approaches to the full duplex by the voice switch section VS.
In this manner, the foregoing speakerphone is able to estimate the performance variation of the echo canceler from the integrated power of the input signal that the adaptive filters 12 referred to during leaning. Accordingly, putting the echo canceler and the voice switch into cooperation, the speakerphone is able to achieve a full-duplex communication system, which improves in the transmit/receive switching performance and presents a better feeling during operation compared to the conventional speakerphone. Further, the performance variation of the foregoing echo canceler can be estimated by a simple arithmetic process, thereby achieving a speakerphone that is inexpensive and consumes a less power. Further, the threshold is varied in correspondence with the performance of the echo canceler that varies with time during communication, which makes unnecessary to use that unpleasant calibration tone.
The speakerphone relating to the foregoing embodiment integrates the speakerphone (corresponding to a first invention) that can vary the acoustic echo threshold with the speakerphone (corresponding to a second invention) that can vary the line echo threshold. However, when the acoustic echo is ignorable because the microphone 1 is located distant from the speaker 3 , or when the line echo is ignorable because the communication line is made up with a short distance and two-way communication line directly connected, it is possible to form each of the speakerphone that can vary the acoustic echo threshold and the speakerphone that can vary the line echo threshold into a separate construction. In this case, the threshold is only needed to be varied as to either the acoustic echo or the line echo, which favors a further low cost. Such a speakerphone is included within the invention.
Further, in the foregoing embodiment, the performance variation of the adaptive filters 12 is estimated by using the integrated power of the past input signal. However, as shown in FIG. 5, the performance variation may be estimated on the basis of the integrated value of time at which the speech signal is detected. The estimation by the integrated value of time will further reduce the arithmetic processing volume. Such a speakerphone is also an example derived from the invention.
The invention thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
|
The conventional speakerphone using the voice switch, when combined with the echo canceler, involves a problem that the threshold for switching the transmit/receive state of the voice switch cannot comply smoothly and stably with the performance variation of the echo canceler, thereby obstructing echo canceling in a manner that the voice switch cooperates with the echo canceler.
The speakerphone of the invention estimates the performance variation of the adaptive filter by using the integrated value of a power of the receive signal or the transmit signal referred in the past when the adaptive filter learns, and varies the threshold in accordance with the performance variation. Thus, the speakerphone of the invention achieves a stable communication system that approaches to the fill duplex with the voice switching system and the echo canceling system combined.
| 7
|
FIELD OF THE INVENTION
The invention relates to hoods for heavy trucks of the type that are hinged and pivot at a front end of the truck. More particularly, the invention relates to a hinge arrangement for a hood that provides a horizontal pivot axis and a vertical pivot axis allowing the hood to tilt forward and then swing laterally open.
BACKGROUND AND SUMMARY
Heavy trucks of the conventional engine-forward architecture typically have hoods that are hinged at the front of the truck frame, allowing the hood to be pivoted forward on a horizontal axis to an open position. These hoods are usually integrated with the fenders so that the hood/fender assembly pivots as a unit. While this allows access to the engine, there is room for improvement.
The invention provides a hinge arrangement for a truck hood that provides improved access to the engine and other components mounted near the engine.
More particularly, the invention provides a multiple axis hinge arrangement that allows a heavy truck hood to pivot on a horizontal axis to a forward open position, and then pivot on a vertical axis laterally to expose a front portion of the engine.
An arrangement in accordance with the invention includes a first hinge arrangement mounting a hood to a truck frame that provides relative pivotal movement on a horizontal axis, and a second hinge arrangement mounted to the hood and truck frame that provides pivotal movement of the hood on a vertical axis.
According to one aspect of the invention, the first hinge arrangement providing a horizontal pivot axis is interconnected to a hinge coupling member that mounts to a truck frame. Preferably, the hinge coupling member mounts to the front ends of both frame rails of the truck frame.
According to another aspect of the invention, the second hinge arrangement providing a vertical pivot axis is integrated with the hinge coupling member.
According to yet another aspect of the invention, the hinge coupling member includes on at least a first frame rail a securing device for releasably securing the hinge coupling member to the first frame rail. The second hinge arrangement includes a member interconnected with the hood and located on the second frame rail that provides a vertical pivot axis, wherein, the hinge coupling member may be released from the first frame rail of the truck frame to allow the hood to pivot on the vertical axis of the second hinge arrangement.
According to an embodiment of the invention, the hinge coupling member includes a securing device attached on each side of the truck frame and a second hinge arrangement attached at each side of the truck frame, permitting the hood to be selectively pivoted laterally leftward or rightward.
According to one embodiment, the hinge coupling member includes a first bracket mounted on the truck frame at a first side and a second bracket mounted on the truck frame on a second side, the first hinge arrangement including a first horizontal hinge attached to the first bracket and to the hood and a second horizontal hinge mounted to the second bracket and the hood, the first horizontal hinge and second horizontal hinge being oriented on a common pivot axis.
According to another embodiment, the hinge coupling member includes a bar extending from a first side of the truck frame to a second side of the truck frame, the first hinge arrangement being mounted to the bar and to the truck hood. The second hinge arrangement is integrated or mounted on a first side of the bar and a securing device mounted on a second side of the bar.
Alternatively, a second hinge arrangement and a securing device are mounted on the first side of the bar and on the second side of the bar, so that the hood may be laterally pivoted about either side. The first hinge arrangement may include a first hinge and a second hinge mounted to the bar in spaced relationship. Alternatively, the first hinge arrangement may include a single hinge mounted to the hood and to the bar, which may be suitable for smaller trucks.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to the following Detailed Description read in conjunction with the appended drawings, in which:
FIG. 1 is a side view of a truck having a hood hinged at a front of the truck frame;
FIG. 2 is a perspective view of a hood and truck frame including a hinge assembly in accordance with the invention with the hood shown in a pivoted-open position;
FIG. 3 is a perspective view of an embodiment of a hinge assembly of the invention for a left frame rail shown removed from the truck and in a pivoted-open position;
FIG. 4 is a perspective view of a frame bracket for the assembly of FIG. 3 ;
FIG. 5 is a perspective view of a hinge member for the assembly of FIG. 3 ;
FIG. 6 is a perspective view of a coupling member of the hinge assembly of FIG. 3 ; and,
FIG. 7 is a perspective view of an alternative coupling member mounted on a frame bracket.
DETAILED DESCRIPTION
FIG. 1 shows a simplified side view of a heavy truck 10 , sectioned to illustrate only the front end, including the cab portion 12 , hood 14 , and engine 28 . The hood 14 is mounted by a hinge 16 at the front of a truck frame 18 . The hinge 16 is mounted at a front end 22 of a frame rail 20 , and provides a horizontal pivot axis oriented laterally to a truck longitudinal axis (the horizontal axis is perpendicular to the drawing plane). The hinge 16 is shown on the front left of the truck frame 18 and another hinge (not illustrated) would be mounted to the front right of the truck frame. The hinge 16 allows the hood to pivot forward from a closed position (illustrated in broken lines as 14 ′) to an open position as shown in solid lines. When in the open position, the hood 14 allows access to the engine 28 for service, repair, and the like. A bumper, including a bumper end cap 24 (only the end cap is visible), is mounted to the front end 22 of the frame 18 below the hood 14 . The bumper end cap 24 is shown in broken line to reveal the hinge 16 and frame rail 20 . A gas spring 26 helps counterbalance the weight of the hood 14 . Other devices, such as torsion springs, may be used.
FIG. 2 shows a perspective view of a hood 14 and frame 18 having a hinge assembly 50 in accord with the invention. As shown in FIG. 2 , the hood 14 has been pivoted longitudinally forward in relation to the truck frame 18 to an open position as in FIG. 1 , and then pivoted laterally, opening a front area of the engine compartment. The hood 14 is shown as laterally pivoted on a right side frame rail 21 ; however, as will become apparent, the hinge arrangement of the invention can allow pivoting alternatively on the left side frame rail 20 , or alternately on either frame rail.
In FIG. 2 , a bumper 25 and a bumper end cap 24 are shown mounted to the hinge assembly 50 so that the bumper 25 and bumper end cap 24 pivot laterally with the hood 14 .
FIG. 3 illustrates an embodiment of a hinge assembly 50 of the invention in a perspective view from the rear and removed from the truck frame. The hinge assembly 50 is mounted to the truck frame (not illustrated) by way of a frame bracket 40 . The hinge assembly 50 includes a vertical axis V for pivoting the hood as further described below. A hinge coupling member 70 is mounted to the frame bracket, both releasably and alternately for pivoting movement, as described in more detail below. The hinge coupling member 70 supports a hinge member 52 that attaches to the hood.
The hinge assembly 50 , hinge coupling member 70 , and frame bracket 40 shown in FIG. 3 represent a left side assembly (left being the driver side of the truck). A right side assembly is a mirror image of the illustrated left side assembly, and its construction will be understood by those skilled in the art without further description.
The frame bracket 40 is mounted to a frame rail (not shown in FIG. 3 ) and, as is known in the art, may include mounting support structure for components located at the front of the truck, for example, the radiator and the front cross member. Referring now also to FIG. 4 , in which the hinge coupling member 70 is removed, the frame bracket 40 of the illustrated embodiment includes an upper bracket 42 and a lower bracket 44 extending horizontally from the frame bracket. The upper bracket 42 and lower bracket 44 are vertically spaced and have mounting holes that are vertically aligned. The upper bracket 42 and lower bracket 44 support the hinge coupling member 70 . The frame bracket 40 is normally intended to be permanently fixed to the frame rail; accordingly, it is considered for the purposes of the invention a part of the frame.
The hinge assembly 50 includes the first hinge 52 that provides a horizontal pivotal axis. As shown in FIG. 5 , the first hinge 52 is formed as a J-hook, having a J-shaped body 54 , a base 56 for mounting the J-hook to the hood, and a hub 58 that pivots on a pin 60 . The pin 60 defines a horizontal axis H for pivoting the hood between the longitudinally forward open and rearward closed positions.
Referring again to FIG. 3 , the hinge coupling member 70 connects the first hinge 52 to the frame bracket 40 by way of the pin 60 , as explained below. Turning also to FIG. 6 , the hinge coupling member 70 includes a body 72 mounted to the frame bracket 40 for pivoting movement on a vertical axis V (indicated in FIG. 3 ). The body 72 includes an upper leg 74 and a lower leg 76 that connect to the upper bracket 42 and lower bracket 44 , respectively, of the frame bracket 40 . A hole 75 in the upper leg 74 is vertically aligned with a hole 77 in the lower leg 76 . A vertical hinge arrangement may include an upper hinge pin 78 extending through the hole 75 in the upper leg 74 to connect the upper leg to the upper bracket 42 and a lower hinge pin 80 , (see, FIG. 3 and FIG. 4 ), extending through the hole 77 in the lower leg 76 to connect the lower leg to the lower bracket 44 . The hinge pins 78 , 80 may be configured as bolts, as shown. Alternatively, a single hinge pin may extend through and connect the brackets 42 , 44 and legs 74 , 76 .
The body 72 includes a face 82 on which a bumper or bumper end cap support may be connected, which includes a plurality of mounting holes for fasteners (not illustrated).
The hinge coupling member 70 includes a hinge support arm 86 extending forwardly of the body 72 . The hinge support arm 86 includes a bore 88 to support the pin 60 and interconnect with the hub 58 of the first hinge member 52 .
According to the illustrated embodiment of FIG. 2 , a hinge assembly 50 , including a first hinge member 52 and hinge coupling member 70 , is mounted on a front end of a left frame rail and a second hinge assembly is mounted to a right frame rail of a truck frame. As shown, the hinge coupling member 70 of the left frame rail 20 is detached from the frame bracket 40 .
According to the invention, the hinge coupling member 70 is releasably connected to the frame bracket 40 by the hinge pins 78 , 80 . Optionally, an additional single fastener or two fasteners may be used with holes 79 , 81 in the upper leg 74 and lower leg 76 . By removing the hinge pins 78 , 80 (or optional single pin) and additional optional fasteners, the hinge coupling member 70 is released from the frame bracket 40 . The opposite side hinge coupling member, still supported by the vertical hinge (hinge pins 78 , 80 or a single pin) is then free to pivot on the vertical hinge axis V, allowing the hood to pivot laterally. If an additional fastener or fasteners are used to secure the opposite side coupling member (as described for the coupling member 70 , above), it would be necessary to remove the additional fasteners to allow the opposite side coupling member to pivot.
According to another embodiment of the invention, the left side and right side hinge assemblies may be interconnected by a bridging member, for example, a bar. This allows the first hinge members to be positioned at a position other than mounted to the frame brackets at the front of the right and left frame rails, if desired.
The illustrated hinge coupling member 70 is shown is for the purposes of description of an embodiment of the invention. A hinge coupling member suitable for the invention includes a portion to support the first hinge member 52 and a portion to mount to the vehicle frame for pivoting movement. Configurations other than as illustrated that satisfy these functions are encompassed by the invention. For example, FIG. 7 shows an alternative hinge coupling member 90 having a body 92 formed as a block or plate having two parallel cylindrical bores 94 , 96 . A first bore 94 supports a hinge pin 98 and a second bore carries a fastener 99 for releasably securing the member 90 to a plate 100 . The plate 100 is mounted to a lower bracket 110 of the frame bracket 112 . An upper arm for the frame bracket as in FIGS. 3 and 4 is omitted. A hinge support arm 102 for extends forward of the body 92 . The hinge support arm 102 includes a bore 104 to support the pin 60 and interconnect with the hub 58 of the first hinge member 52 of FIG. 5 .
The invention has been described in terms of preferred principles, embodiments, and components. Those skilled in the art will understand that substitutions of specific components may be made without departing from the scope of the invention as defined in the appended claims.
|
A multiple axis hinge arrangement for a truck hood includes a first hinge arrangement and a second hinge arrangement laterally spaced and mounted at first and second sides, respectively, of a front end of a truck. The first and second hinge arrangements include horizontal hinge elements that support a truck hood for pivotal movement on a horizontal axis relative to a truck frame and include vertical hinge elements that provide vertical pivot axes. A coupling member is provided at each of the first and second hinge arrangements allowing the selected hinge arrangement to be uncoupled from the front end of the truck so the hood is free to pivot on the vertical axis of the coupled arrangement.
| 4
|
BACKGROUND OF THE INVENTION
The invention concerns an inlet for a separator (separator tank) in a process plant, for example a plant for processing a fluid consisting of oil, water and/or gas.
The inlet arrangement in a separator in a process plant usually has several purposes. First, the inlet reduces the impulse to incoming fluid to prevent the inlet flow from disturbing the steady flow conditions required in the separator. Second, the inlet prevents sand or similar material in the process flow from being deposited in places where this is undesirable. Thirdly, the inlet prepares the process flow so that the conditions for good separation are optimal.
In practice, impulse reduction is usually the guiding factor for the design of an inlet in a separator. A widely known impulse reduction solution is based on the use of a flow interruption plate arranged just outside the separator inlet. The fluid flow meets the plate and is spread outwards and possibly backwards if the plate is curved. Another impulse reduction solution is based on the use of a U-shaped pipe in connection with the inlet to “return” the flow towards the separator wall. A third solution is based on the use of a T-pipe section in connection with the inlet to interrupt the fluid flow and steer it sideways.
However, all of these solutions create a greater or lesser degree of spray, agitation and disturbance to the surface of the fluid, which means that the conditions for good separation are not achieved or are poor. If the fluid supply flow consists of oil and water, large shear stresses, for example as a result of pressure loss across a valve or sudden changes of speed, can lead to the oil and/or water being turned into small drops and a so-called emulsion being formed. In its simplest form, the emulsion is either oil-in-water (oil drops in water) or water-in-oil (water drops in oil). Surfactants in the oil can stabilize the emulsion and make it difficult to separate the oil and water. Water-in-oil emulsions are considered to be more difficult to break down than oil-in-water emulsions.
If the fluid supply flow contains free gas in addition to oil and water, shear stresses to which the fluid supply flow is exposed can lead to the formation of small gas bubbles which are mixed with the fluid phases. These gas bubbles can have an emulsion-stabilizing effect like the surfactants in oil.
SUMMARY OF THE INVENTION
The present invention represents an inlet to a separator in which the fluid inlet flow is not exposed to unnecessarily large shear stresses (plunging, sudden changes of speed), and in which free gas which may be present in the fluid supply flow is released before the fluid flow is exposed to shear stresses. Moreover, the present invention represents an inlet which produces steady flow conditions in the separator and prevents any sand or other particulate contaminants from being deposited in places where this is undesirable.
The present invention is characterized in that the separator inlet is designed as a spiral channel open at the top in a channel housing. The fluid flows in tangentially and flows out through a central outlet in the housing downwards.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in the following in further detail with reference to the attached drawings, in which:
FIG. 1 shows a separator inlet in accordance with the present invention arranged in a separator tank;
FIG. 2 shows, in the form of a schematic diagram, an outline of the separator inlet;
FIG. 3 is a schematic diagram of the same inlet seen from above; and
FIG. 4 is a schematic diagram of the inlet shown in FIG. 2 during operation, i.e. filled with a fluid, for example oil/water containing gas.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows, as stated, a separator inlet 1 in accordance with the present invention arranged in a separator tank 2 . The separator inlet is placed in connection with the surface of the fluid, and the fluid is supplied to the separator inlet from outside via a supply line 3 .
The separator inlet 1 comprises, as shown in FIG. 2 and FIG. 3, a channel housing 4 with channels 10 open at the top which run from a tangentially-located connection line (first line) 5 for the supply line 3 in a spiral path to an outlet line (second line) 6 which is arranged centrally in the housing 4 .
The housing 4 may expediently be made of a disc-shaped plate 7 and inward-sloping plates 8 , 9 arranged on this disc-shaped plate 7 which run in a spiral path and form walls in a channel 10 . A circular, pipe-shaped part with openings 11 to the channel 10 may also expediently form the outlet 6 in the housing. The housing 4 may be equipped with a lid over the channel, but any lid must be provided with openings for the evacuation of gas.
In order to trap any gas bubbles which are released at the outlet line (second line) 6 in the housing 4 , it is preferable to arrange a funnel-shaped gas trap 12 which is connected to the housing via mounting pieces 13 . The gas trap 12 is designed to extend slightly below the second line 6 to just above the surface of the fluid outside the housing 4 .
The separator inlet works in the following way. The fluid is introduced into the channel 10 in the housing 4 from the pipe 5 and flows in spiral path through the channel 10 in the housing to the outlet 6 while releasing any gas. The fluid then flows downwards through the outlet 6 , and any remaining gas will be trapped by the funnel-shaped trap 12 and conveyed to the surface. Alternatively, the flow can be in the opposite direction (i.e., the inflow can be via the centrally-located second line 6 from above, and the outflow can be tangential via the first line 5 , which will be immersed in the fluid in the separator).
The housing may expediently be made by casting or of welded plates of a corrosion-resistant material, for example stainless steel.
EXAMPLE
Comparative tests were performed in a Plexiglas model of a separator in the scale 1:4.5. Water, Exxol D80® and air were used for the three phases in the fluid, which was supplied to a separator inlet in accordance with the present invention and to a well known separator inlet of the impulse type with two sets of plate packs in the water phase. The tests for the two separator types were performed under the following conditions.
Water cut (percentage content of water)
60%
Gas/fluid ratio (volume)
1.2
Mixing speed (inflow speed of fluid)
6 mls
Oil in water was measured with a Horiba® IR instrument.
The following results were obtained:
Oil in water at
Oil in water at
inlet of separator
outlet of separator
Widely known impulse type inlet
110-140 ppm
400-500 ppm
Inlet in accordance with the present
100-150 ppm
220-300 ppm
invention
As the results show, the separator inlet in accordance with the present invention produces a much lower content of oil in water (better water quality) at the separator outlet than the well known inlet.
|
A separator inlet includes a spiral channel in a channel housing and having an open top. Fluid flows in tangentially and out of a central outlet of the channel housing, or in a reverse direction.
| 4
|
FIELD
[0001] The disclosure relates to audio and video devices. More particularly, the disclosure relates to an audio and video system including an entertainment module and a docking station.
BACKGROUND
[0002] The worldwide digital video disk (DVD) market is maturing and has become accepted as the standard for viewing audio and video on a television, computer monitor, or the like. In the domestic United States for example, DVD player units were first available in 1997, with 349,000 units being shipped and 200,000 units being sold. In 1997, approximately 900 DVD programming content titles were available. By the year 2004, 530,000,000 DVD player units were shipped in the United States with 37,000,000 units being sold; in the same year, the number of available DVD titles for purchase grew to 29,000. It is estimated that by the end of the year 2005, at least one DVD player will be in at least 80% of United States households, accounting for more than 70,000,000 homes.
[0003] In addition to home DVD players, portable DVD players including, for example, a 5-inch liquid crystal display (LCD) screen have become widely popular, allowing DVD enthusiasts to enjoy their DVD titles remotely from their home. DVD players are also being offered as an originally-installed feature in many vehicles, or, alternatively, as an after-market component that a user or skilled technician may install within the vehicle. Accordingly, the home, portable, or vehicular DVD player has become a ubiquitous device, allowing consumers to enjoy DVDs from their library in virtually any environment.
[0004] Although adequate for most applications, DVD players do not permit consumers to access programming content that may not be already part of their entertainment library. Even further, consumers are often required to purchase multiple DVD players to utilize their DVD library in different environments; for example, as described in the above scenarios, a consumer may purchase a first DVD player as a component for their home theater system. Then, a second DVD player may be purchased for utilization in a first portable situation such as, for example, while a user is taking a walk. Then, thirdly, a DVD player may be purchased for utilization in a second portable situation such as, for example, as an originally-installed component in a vehicle that may be part of a premium vehicle package.
[0005] Accordingly, a need therefore exists to provide a device that eliminates the need to obtain a plurality of DVD players in various platforms, thereby saving the consumer money by not having to purchase a plurality of DVD players or upgrading to premium vehicle packages to obtain a DVD player as an originally-installed component in a vehicle. Even further, a need exists to permit DVD enthusiasts to obtain programming content that is not included in their DVD library.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The inventors of the present disclosure have recognized these and other problems associated with fixed and/or portable DVD devices. The present disclosure will now be described, by way of example, with reference to the accompanying drawings, in which:
[0007] FIG. 1 is a perspective view of an entertainment module according to an embodiment;
[0008] FIG. 2A is a perspective view of the entertainment module according to FIG. 1 being inserted into a docking station according to an embodiment;
[0009] FIG. 2B is a perspective view of the entertainment module that is pivotably attached to the docking station according to FIG. 2A ;
[0010] FIG. 3 is a block diagram view of the entertainment module and docking station according to an embodiment;
[0011] FIG. 4 is a block diagram of the entertainment module according to an embodiment; and
[0012] FIG. 5 is a block diagram view of the entertainment module and docking station according to an embodiment.
DETAILED DESCRIPTION
[0013] Referring to FIG. 1 , an entertainment module is generally shown at 10 according to an embodiment. The entertainment module 10 may include at least an output means, such as a display screen 12 and speakers 25 , a plurality of control buttons 14 , an infrared (IR) receiver 16 to enable communication with a remote control 75 ( FIG. 3 ), a pair of mounting pivot studs 18 , and an input means, such as a slot 20 for inputting media programming, such as, for example, a compact disk, CD, or digital video disc, DVD ( FIG. 2B ). Although the slot 20 is shown for inputting a CD or DVD, one or more input means 20 other than a CD/DVD slot may be included, such as, for example, input means for upload MP 3 audio files to a storage means 64 .
[0014] As shown in FIGS. 2A and 2B , the entertainment module 10 may be inserted into and secured/supported by a docking station 50 . The docking station 50 may be located, for example, in a vehicle ( FIG. 3 ), or alternatively, in a home ( FIG. 5 ). If located in a vehicle, the docking station 50 may be affixed to, for example, a vehicle's headliner 100 ; alternatively, if located in a home, the docking station may be located, for example, under a kitchen cabinet, or, alternatively on a table-, counter-, or desk-top. Although the entertainment module 10 may be inserted into and secured by the docking station 50 for, if desired, pivotable deployment in the direction of arrow, D, it will be appreciated that the entertainment module 10 may be a stand-alone device that may be utilized on its own without being inserted into the docking station 50 ; accordingly, the entertainment module 10 may be utilized as an independent, portable device for playing media programming stored on a CD or DVD, or, alternatively, accessed wireless programming as described below.
[0015] Referring to FIG. 3 , a docking station, which is seen generally at 50 a , is attached to the vehicle headliner 100 . The entertainment module 10 is attached to the docking station 50 a by a connector 22 . The connector 22 may extend from either the entertainment module 10 , or, alternatively, from the docking station 50 a . Once the entertainment module 10 and docking station 50 a are connected, the entertainment module 10 may draw power from the vehicle's battery through the connector 22 while also sending/receiving audio and/or video programming to and from the entertainment module 10 and docking station 50 a through the connector 22 .
[0016] As illustrated, the docking station 50 a , includes, for example, IR transmitters 52 for transmitting wireless audio signals to headphones 125 . The docking station 50 a also includes an auxiliary battery slot 54 as a supplemental power source to the vehicle's battery if the entertainment module 10 is being operated with docking station 50 a when the vehicle in the keyed-off position. In an alternative embodiment, the battery slot 54 may be included in the entertainment module 10 . Additionally, it will be appreciated that circuitry (not shown ) located within the docking station 50 a may be utilized to charge a battery inserted into the auxiliary battery slot 54 when the vehicle is in the keyed-on position. The docking station 50 a may also include an IR receiver 56 connected to an interface box 58 that provides an output to a data-bus 60 for controlling other components in the vehicle, such as, for example, the radio, which may be located in a head unit proximate the dashboard (not shown). Conversely, it is contemplated that the interface box 58 may permit vehicle passengers in the front seat of the vehicle to control the entertainment module 10 in the back seat by pressing control buttons located proximate the dashboard.
[0017] The docking station 50 a also includes an optional wireless module 62 . The wireless module 62 may be, for example, a “Wireless-X” module, such as, a Wireless-B (i.e. 802.11b), Wireless-G (i.e. 802.11g), Wireless-N (i.e. 802.11n), or any other desirable Wireless-“X” (i.e. 802.11“X”) technology. Alternatively, the wireless module 62 may include BLUETOOTH®, Ultra-wideband (UWB), or a similar technology. As illustrated, the wireless module 62 is connected to an optional storage means, such as a hard drive device (HDD) 64 . The wireless module 62 may receive, for example, wirelessly downloaded audio and/or video content from an antenna 66 for playback over the speakers 25 and/or the display screen 12 .
[0018] As shown in FIG. 4 in an alternative embodiment, the entertainment module 10 may include the antenna 66 , wireless module 62 and the HDD 64 . As such, it will be appreciated that the docking station 50 a , may, if desired, be merely utilized as a structural element to support/retain the entertainment module 10 while also providing power to the entertainment module 10 (i.e., the docking station 50 a may be designed to not include the wireless module 62 and HDD 64 ). Alternatively, the entertainment module 10 may include its own power source so as to further reduce a wiring/circuitry interface (e.g. the connector 22 ) between the docking station 50 and entertainment module 10 . Although the wireless module 62 and HDD 64 are shown connected to each other while being located in the same device, it will be appreciated that the wireless module 62 may be located in the docking station 50 a while the HDD 64 is located in the entertainment module 10 , and vice-versa.
[0019] The source for providing the wireless download of information to the antenna 66 may be, according to an embodiment, a wireless router, R, that is commercially available, for example, from LINKSYS® of San Jose, Calif. and sold as model number WAP54G. Accordingly, it is contemplated that when the vehicle is located in the homeowner's garage or driveway within a broadcast radius of the wireless router, R, the antenna 66 connected to the wireless module 62 , which may be part of the docking station 50 a or entertainment module 10 , may receive the downloaded programming. Alternatively, the entertainment module 10 may be located within the home and in the broadcast radius of the wireless router, R, to directly download the programming to the entertainment module 10 . In another embodiment, the docking station 50 a or entertainment module 10 may receive the downloaded content from a “wireless hot spot” proximate a restaurant, coffee house, or the like that provides free wireless internet access; accordingly, the user may park the vehicle including the docking station 50 a nearby the restaurant, coffee house, or the like to receiving the wireless broadcast, or, alternatively, the user may bring the entertainment module 10 with the restaurant, coffee house, or the like. Upon receiving the downloaded audio and/or video content at the antenna 66 , the downloaded content may be stored on the HDD 64 for subsequent playback on the display screen 12 .
[0020] Referring to FIG. 5 , a docking station 50 b and the entertainment module 10 are shown according to an embodiment. The entertainment module 10 and docking station 50 b may be located, for example, in a home or office, and interfaces in a similar manner as the docking station 50 a described above in that upon connecting the entertainment module 10 and docking station 50 a , the entertainment module 10 may draw power from the home or office's 120V AC power and send/receive audio and/or video content to and from the entertainment module 10 and docking station 50 b . If desired, the docking station 50 b may also include a slot 54 for recharging an external battery that is used, for example, in the docking station 50 a or entertainment module 10 .
[0021] As described above in relation to the docking station 50 a , the docking station 50 b may also include an optional wireless module 62 connected to an optional hard drive device (HDD) 64 to wirelessly access and download audio and/or video content. Additionally, the docking station 50 b or entertainment module 10 may be connected to an external device 150 , such as, for example, a personal computer, modem, or set-top box. The external device 150 may be for example, a set-top box 150 , as shown in FIG. 5 . As is known in the art, the set-top box 150 may provide cable or satellite television programming to a television 175 . If implemented as shown in FIG. 5 , the entertainment module 10 and set-top box 150 may be connected with any desirable input/output connection, such as, for example, an S-video cable 152 , an audio cable 154 , a 1394/USB cable 156 , or the like; however, if the entertainment module 10 directly receives the cable or satellite programming (i.e. there is no intermediate connection of the docking station 50 b ) it will be appreciated that the connections 152 - 156 may directly connect the external device 150 and entertainment module 10 .
[0022] Programming content received by the set-top box 150 may be stored in the HDD 64 of the docking station 50 b or entertainment module 10 . If desired, the downloaded programming may be obtained by the docking station 50 b or entertainment module 10 directly from a coaxial connection that is fed into the set-top box 150 or entertainment module 10 ; however, a wireless router, R, as described above, may wirelessly transmit the programming content to the docking station 50 b or entertainment module 10 . Thus, the entertainment module 10 may be used as a home theatre DVD player, or, alternatively, the docking station 50 b or entertainment module 10 may be used as a digital video recorder (DVR) in a home theater system to play saved programming originating from the set-top box 150 or cable provider (i.e. directly from a coaxial cable from “basic cable” service that does not utilize a cable box). Although not shown in FIG. 5 , it will be appreciated that the docking station 50 b and entertainment module 10 may be connected to a device other than a set-top box 150 ; for example, the docking station 50 b and entertainment module 10 may be connected to, for example, a receiver/amplifier to amplifier and output sound over home theater speakers while a video cable may directly connect the television 175 and docking station 50 b or entertainment module 10 to provide the video content on the television 175 .
[0023] Accordingly, the fixed/portable audio and/or video system described above may permit a consumer to save money by purchasing a single entertainment module 10 , which may be used in any desirable fixed or portable environment. If the consumer chooses to utilize the entertainment module 10 in a home and vehicular application, the consumer may elect to purchase no or any desirable number of docking stations 50 a , 50 b for home or mobile use. Even further, the entertainment module 10 or docking station may include an antenna 66 , wireless module 62 , and HDD 64 that permits the user to download and store programming content that is not part of their DVD library.
[0024] While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.
|
An audio and/or video system is disclosed. The audio and/or video system includes an entertainment module adapted for connection to a docking station. The entertainment module includes output means for provding programming that is audible and visible. The entertainment module includes an antenna connected to a wireless module that wirelessly accesses wireless audio and/or video programming, a storage means for storing the wireless audio and/or video programming, and an input means for receiving a compact disc or digital video disc that stores media audio and/or video programming. The docking station may optionally include the antenna, wireless module and storage means.
| 6
|
This application is a divisional of application Ser. No. 08/903,623, filed Jul. 31, 1997, now U.S. Pat. No. 5,932,072, which is a continuation-in-part of application Ser. No. 08/837,755, filed Apr. 22, 1997 now U.S. Pat. No. 5,922,173.
BACKGROUND OF THE INVENTION
1. Field of the Invention
First and second aspects of this invention relates to the creation of stock activity and the control of drainage in a Fourdrinier table, particularly by the use of lifting variable inertial stimulation blades which can further include limited-vent indented surfaces.
Additionally, a third aspect of this invention relates to the variable tilting of the inertial stimulation blades, the inertial stimulation blades being provided in component pieces, the use of ceramic inserts at wear points of the inertial stimulation blades, and the use of button or disk-based mounting apparatus for the inertial stimulation blades.
2. Description of the Prior Art
Stock activity in the early part of a Fourdrinier table is critical to the production of a good sheet of paper. Generally, stock activity can be defined as turbulence in the fiber-water slurry on the forming fabric. This turbulence takes place in all three dimensions. Activity plays a major part in developing good formation by impeding stratification of the sheet as it is formed, by breaking up fiber flocs, and by causing fiber orientation to be random. Typically, stock activity quality is inversely proportional to water removal from the sheet. That is, activity is typically enhanced if dewatering is retarded. As water is removed, activity becomes more difficult because the sheet becomes set, and because water, which is the primary media in which the activity takes place, becomes scarcer. Good paper machine operation is therefore a balance between activity and drainage.
There are a number of conventional methods to promote activity and drainage. A table roll causes a large positive pressure pulse to be applied to the sheet resulting from water under the forming fabric being forced into the incoming nip formed by the roll and forming fabric. This positive pulse has a positive effect on stock activity by causing flow perpendicular to the sheet surface. Similarly, on the exiting side of the roll, large negative pressures are generated, which greatly enhance drainage. Table rolls are generally limited to relatively slow machines because at high speeds, the positive and negative pulse amplitudes become excessively large. Foils are used to promote and control activity and drainage. A vacuum pulse is generated by the nip formed by the forming fabric and conventional foil as the fabric passes over the foil. Activity is generated by using a number of consecutively placed foils, encouraging a positively reinforced activity in the stock. Another type of foil, sometimes referred to as a "posi-blade", incorporates a positive incoming nip to generate a positive and negative pressure pulse. The amplitude of the pressure pulse is determined in a large part by the angle formed by the fabric and the incoming edge of the foil. This type of foil simulates a table roll, but with much lower amplitude positive and negative pressure pulses. The amplitudes are determined by the speed of the machine and the angles of the foils.
Often, Fourdrinier tables are mechanically shaken to promote stock activity, especially on slower, narrower machines. While the shaking might be a good way to enhance formation it is undesirable because it is difficult and expensive to control and maintain, and generally punishing on the equipment on and around the Fourdrinier Table. For paper making in general, most activity inducing systems have the negative feature of excessive drainage.
In patent application Ser. No. 08/600,833, entitled "Velocity Induced Drainage Method and Unit", filed on Feb. 12, 1996, now U.S. Pat. No. 5,437,769 discloses an alternate way of creating activity and drainage. The apparatus disclosed therein, and illustrated herein as FIG. 1, decouples activity and drainage and therefore provides independent control and optimization of activity and drainage. The device typically uses a long blade with a controlled, at least partially non-flat or undulated, surface to induce initial activity in the sheet, and limits the flow downstream of the blade through placement of a trail blade to control drainage. Drainage is enhanced if the area between the long blade, the forming fabric and trail blade remains flooded and surface tension is maintained between the water above and below the fabric. However, the implementation of this device has revealed phenomena previously not fully appreciated. The first occurs in the "counterflow zone" over the long blade, particularly at the undulated portion, where the incompressible fluid is pumped through the forming fabric. This was expected. However, the second activity is much more vigorous and had not been fully appreciated. As the forming fabric spans the relatively long distance between the lead edge of the long blade and the trail blade, it deflects downwardly because of the forces acting on it. These forces are gravitational and also result from the vacuum induction as the fabric travels along the long blade. The latter predominates by far. The wire takes on the shape of a skewed catenary as the forces are asymmetrical along the wire between the support points. If the long blade is high enough or the fabric deflection is severe enough, the wire will contact the long blade and the catenary shape will be further distorted. The activity is induced when the fabric reaches the trail blade. The fabric path must make a rapid transition from the deflected state to the horizontal state very quickly at the leading edge of the trail blade because of the high tensions acting on the fabric path. The fabric path therefore changes sharply as the fabric travels around the sharp leading edge of the trail blade. Inertial forces prevent the fluid slurry of the paper sheet from following the fabric, and inertial activity is induced as the sheet lifts vertically.
Additionally, as the foils are typically made of HDPE (or any other suitable material as would be known to one skilled in the art), any introduction of wear points on the foil may reduce foil life. Similarly, as the foils may require replacement periodically, particularly in a high-speed operation, it is important to be have a mounting system to enable to the rapid replacement of the foils.
Submerged drainage in a Fourdrinier fabric is disclosed by U.S. Pat. No. 5,522,969 to Corbellini et al. entitled "Submerged Drainage Method for Forming and Dewatering a Web on a Fourdrinier Fabric" and U.S. Pat. No. 5,242,547 to Corbellini et al. entitled "Submerged Drainage System for Forming and Dewatering a Web on a Fourdrinier Fabric". Positional control of elements in papermaking apparatus is disclosed in U.S. Pat. No. 5,486,270 to Schiel entitled "Angularly Adjustable Drainage Foil for Paper Machines"; U.S. Pat. No. 5,421,961 to Miller entitled "Forming Board Position Control System"; U.S. Pat. No. 5,262,010 to Bubik et al. entitled "Dewatering Device with Adjustable Force Elements for the Web-Forming Section of a Papermaking Machine"; and U.S. Pat. No. 5,221,438 to Takeuchi et al. entitled "Supporting Device for Dewatering Elements".
U.S. Pat. No. 3,595,747 to Walser entitled "Suction Box Covers with Rows of Drainage Openings for Uniform Dewatering" and U.S. Pat. No. 5,562,807 to Baluha entitled "Cross Direction Fiber Movement and Dewatering Device".
Other prior art includes U.S. Pat. No. 4,687,549 to Kallmes entitled "Hydrofoil Blade"; U.S. Pat. No. 4,838,996 to Kallmes entitled "Hydrofoil Blade for Producing Turbulence"; and U.S. Pat. No. 3,573,159 to Sepall entitled "Deflocculation of Pulp Stock Suspension with Pressure Pulses".
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide controlled stock activity in the papermaking process, particularly in a Fourdrinier table.
It is therefore a further object of this invention to provide controlled drainage in the papermaking process, particularly in a Fourdrinier table.
It is therefore a still further object of this invention to provide controlled stock activity decoupled from controlled drainage in the papermaking process, particularly in a Fourdrinier table.
It is therefore a still further object of this invention to reduce the amount of fluid which is pumped through the forming fabric as the fluid passes over the undulated portion of a long blade in the papermaking process, particularly in a Fourdrinier table.
It is therefore a still further object of this invention to provide a blade with a variable angle and a relative fixed leading edge, particularly in a Fourdrinier table.
It is therefore a still further object of this invention to provide a blade which can be manufactured in elements and assembled together, and which can be easily mounted on a papermaking apparatus, particularly a Fourdrinier table.
It is therefore a still further object of this invention to provide increased resistance to wear at the wear points of a foil in the papermaking processing, particularly in a Fourdrinier table.
It is therefore a final object of this invention to control the sharpness of the path change as the fabric passes over the trail blade in the papermaking process, particularly in a Fourdrinier table.
A first aspect of this invention provides downwardly sloped atmospheric vents extending from the undulated portions of the long blade of the Fourdrinier table. This venting of the counterflow zone to atmosphere equalizes the pressure above and below the fabric and therefore controls the downward force on the fabric thereby controlling deflection with respect to the trail blade, controlling inertial activity and eliminates the vacuum or deflection of the fabric over the counterflow zone. Only gravitation force deflects the fabric, and it has been demonstrated that gravitational deflection is negligible except for very long spans. Furthermore, if the venting is limited or throttled, then deflection can be controlled in an analog manner and activity can be "tuned" for optimum sheet formation. The control of the venting can be uniform or non-uniform across the surface of the long blade for cross-machine profile control or variable drainage in the machine direction. The surface of the long blade can be indented locally or in the cross-machine direction to provide for the vents.
A second aspect of the invention uses an elevator-type configuration to raise or lower the trail blade. This controls stock activity by controlling the sharpness of the path change as the forming fabric travels over the trail blade thereby controlling the inertial activity. When a trail blade is elevated the angle formed by the oncoming fabric and the trail blade surface is maximized. This maximizes the rapid directional change of the fabric and therefore maximizes the inertial activity. Conversely, when the trail blade is lowered, the angle is minimized, and the inertial activity is decreased or eliminated. If the tail of the long lead blade is high enough such that the fabric lands on it as the trail blade is lowered the effect is enhanced.
Additionally, in the second aspect of the invention, successive blades can be cascaded so that the trail blade of the first pair becomes the lead blade of the second pair, etc. As elevations of successive blades are changed, the activity generated over the entire apparatus is affected. Activity can therefore be finely tuned to desired levels. As the path of the fabric determines the effectiveness of the device, it can be used with any length blade, and can be used in conjunction with other control devices, such as the vented blades of the first aspect of this invention.
A third aspect of this invention inclines the blade or foil at a variable angle. This variable angle can be accomplished by a single elevator in the front or rear of the blade in combination with either a hinge or a fixed support. Alternately, the variable angle can be accomplished with a first elevator on the front and a second elevator on the rear of the blade. Additionally, the variable angle can be accomplished by taking advantage of the inherent weight and flexibility of the blade. Additionally, the blade may also include ceramic inserts at the apices of its undulated portions in order to reduce wear. Moreover, the blade is provided in two or more pieces (with the seam at a downwardly inclined portion of the undulation) and the blade is mounted using a "button-type" fixture engaging a slot of T-shaped cross section in the blade.
Traditional foil surfaces for paper machines are short in the machine direction, compared to the special designs of the VID type blades. The length of these blade s vary depending on the specific design of the top surface curvature, which can be comprised of symmetrical undulations, or more likely, skewed profiles to provide desired results.
Based on the fact that most paper machines operate under unique conditions, each blade may be designed to maximize operation and formation for the operating ranges particular to its environment. An important variable in blade design is the specific profile of the top surface. Blade length in the machine direction is dependent on the required hydrodynamic profile desired.
The hydrodynamic profiles are design ed to produce a varying pressure profile over the entire length of the blade. This profile includes both positive and negative pressure pulses that effectively cause counterflows of fluid through the forming fabric. These counterflows create a mixing action that better forms the paper sheet. The pressure pattern is design to create a net vacuum pulse, resulting in drainage of fluid after significant mixing has been induced.
Varying blade lengths that are considerably longer in the machine direction than standard drainage foils presents a manufacturing challenge in both material procurement and physical profiling in a production environment. The jointed design offers a simple, more economical way to produce long, machined foils. In many cases, material availability is limited to lengths less than what is required for the manufacture of custom designed profiles. This created the need for a sectional design.
An additional benefit of the sectional design is that it simplifies manufacturing, by allowing smaller sections to be sculpted independently, making handling and machining less cumbersome.
The joint securing the blades sections to one another is designed to create a sealed lock, so as not to effect the operating pressure and vacuum pulses created by the top surface profile. Further, the location of the joint is selected to be within a lower portion of the undulations to keep its binding and structural integrity from being affected by wear induced by the forming fabric.
The ceramic design incorporating laterally grooved beams securing ceramic components, and spaced by polyethylene sections creates several advantages over traditional ceramic assemblies, both in manufacturing and operation. In manufacturing, the size of individual sections is significantly reduced, making critical machining steps less difficult, and increasing the choices of material available for use in the application. The sectional assembly also allows for custom fitting of parts to each other.
The ceramic portions of the profile are preferably located only at the critical wear points, and therefore are not a major portion of the special blade profile. The polyethylene spacers make up most of the blade shape and because of this, several different blade profiles can be utilized simply by changing the polyethylene spacer designs. These spacer bushings are removable and thereby can be replaced with new spacers of any variation of shape.
The machine direction length of the blades since it is relatively long requires secure mounting thereof. Typically, one hold down slot is used for the typical shorter foil blades. The blades of the present application are typically much larger, and due to their operating forced involved with their design, it is desirable to secure the mounting structure by at least two or more slots, one at each end of the foil.
Note that because of the general size and weight of the foils, it makes it relatively more difficult to install and secure them to the structure in the traditionally employed manner ("T"-bars). The cylindrical "button `T`" design allows for simple installation by creating significantly less frictional resistance between the blade and the securing mechanism. This is realized by the fact that the buttons are spaced apart on the structure, and therefore do not create a continuous contact point between the blade and the hold down. They also have diametric clearance, allowing them to follow the hold down slot in the blade as it is installed on the structure, thereby minimizing the need for strict tolerances of the slots during manufacture.
These types of hold-downs may be utilized with any foil type that has significant cross machine direction rigidity.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:
FIG. 1 is a cross-sectional view of a prior art blade arrangement.
FIG. 2 is a cross-sectional view of the vents of a first aspect of the present invention.
FIG. 3 is a cross-sectional view of the elevator-type configuration of a second aspect of the present invention.
FIG. 4A is a cross-sectional view of the effect on the inertial zone by raising the trail blade in the second aspect of the invention.
FIG. 4B is a cross-sectional view of the effect on the inertial zone by lowering the trail blade in the second aspect of the invention.
FIG. 5 is a cross-sectional view of a third aspect of the invention using a single elevator and a hinged section to achieve a variable angle of the blade.
FIG. 6 is a cross-sectional view of the third aspect of the invention using an elevator and a support (which could be a second elevator) to achieve a variable angle of the blade.
FIG. 7A is a cross-sectional view of the third aspect of the invention illustrating a two-piece design and the mounting slots of a "T" cross section.
FIG. 7B is a cross-sectional view of an alternative embodiment of the third aspect of the invention, illustrating the use of ceramic inserts at the apices of the undulations.
FIG. 8 is a perspective view of the mounting button used for the mounting system in combination with the mounting slots of FIG. 7A.
FIG. 9A is a top view of the third aspect of the invention showing the modular design for use with the ceramic inserts at wear points.
FIG. 9B is a front view of the third aspect of the invention showing the modular design for use with the ceramic inserts at wear points.
FIG. 9C is a side cross sectional view of the third aspect of the invention showing the modular design for use with the ceramic inserts at wear points.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in detail wherein like numerals indicate like elements throughout the several views, one sees that FIG. 2 is a cross-sectional view of a first aspect of the invention. The long blade 10 has undulations 12 which generally decline in the machine direction. The forming fabric 100 traverses a path immediately above and supported by the long blade 10 and then immediately above and supported by trail blade 14. A counterflow zone 102 is formed above long blade 10 and an inertial zone 104 is formed above trail blade 14. Water is both above and below forming fabric 100 and is drained through the passageway 16 immediately between long blade 10 and trail blade 14. In the area of the undulations 12 of long blade 10, generally downwardly extending vents 18 are formed. Vents 18 allow liquid flow therethrough and equalize the pressure between the counterflow zone 102 and atmosphere. This venting of the counterflow zone 102 to atmosphere equalizes the pressure above and below the forming fabric 100 and therefore controls the downward force on the forming fabric 100 thereby controlling deflection with respect to the trail blade 14, controlling inertial activity and eliminating the vacuum or deflection of the fabric over the counterflow zone 102. Only gravitation force deflects the fabric, and it has been demonstrated that gravitational deflection is negligible except for very long spans. Furthermore, if the venting is limited or throttled, such as is illustrated by valve or throttle 20, then deflection can be controlled in an analog manner and activity can be "tuned" for optimum sheet formation. The control of the venting can be uniform or non-uniform across the surface of the long blade 10 for cross-machine profile control or variable drainage in the machine direction. The vents 18 can be throttled independently or in gangs of any combination. The surface of the long blade can be indented locally or across the cross-machine direction to provide for the vents 18.
Alternatively, the vents 18 can be connected to a cavity in which the vacuum level is controlled. Thus the pressure level between the wire and blade can be independently controlled.
Referring now to FIG. 3, one sees a cross-sectional view of a second aspect of the invention. As in FIG. 2, the long blade 10 has undulations 12 which generally decline in the machine direction. The forming fabric 100 traverses a path immediately above and supported by the long blade 10 and then immediately above and supported by trail blade 14. A counterflow zone 102 is formed above long blade 10 and an inertial zone 104 is formed above trail blade 14. Water is both above and below forming fabric 100 and is drained through the passageway 16 immediately between long blade 10 and trail blade 14. The trail blade 14 further includes blade elevator 22 which raises and lowers trail blade 14. The vertical raising and lowering of trail blade 14 varies the angle θ (see FIG. 4A). That is, lowering trail blade 14 by way of blade elevator 22 reduces e as shown in FIG. 4B while raising trail blade 14 by way of blade elevator increases θ as shown in FIG. 4A. This controls stock activity by controlling the sharpness of the path change as the forming fabric 100 travels over the trail blade 14 thereby controlling the inertial activity. When a trail blade 14 is elevated the angle θ formed by the oncoming fabric and the trail blade surface is maximized. This maximizes the rapid directional change of the forming fabric 100 and therefore maximizes the inertial activity. Conversely, when the trail blade 14 is lowered by blade elevator 22, the angle θ is minimized, and the inertial activity is decreased or eliminated. If the tail of the long lead blade is high enough such that the forming fabric 100 lands on it as the trail blade 14 is lowered the effect is enhanced.
Additionally, in the second aspect of the invention, successive blades can be cascaded so that the trail blade of the first pair becomes the lead blade of the second pair, etc. As elevations of successive blades are changed, the activity generated over the entire apparatus is affected. Activity can therefore be finely tuned to desired levels. As the path of the fabric determines the effectiveness of the device, it can be used with any length blade, and can be used in conjunction with other control devices, such as the vented blades of the first aspect of this invention.
Referring now to FIGS. 5-9C, one sees the third aspect of the invention. In particular, FIG. 5 illustrates blade or foil 30 with a fixed leading edge 32. Trailing undulated portion 34 is attached to fixed leading edge 32 by hinge 36. The angle of trailing undulated portion 34 is adjusted by vertical elevator 38. The design of FIG. 5 has the advantage that the position of the leading edge 32 is fixed, and variation of the angle of trailing undulated portion 34 does not raise or lower fixed leading edge 32.
FIG. 6 illustrates a similar design to FIG. 5. Blade or foil 30 is a one-piece design. The portion of blade 30 proximate to leading edge 32' is coupled to support 36 (which could be fixed or a vertical elevator) while trailing edge 40 of foil 30 is supported by vertical elevator 38. Alternately, support 36 could be a vertical elevator and support 38 could be fixed. Typically, blade 30 rests on fixed support 36 so as to allow a change of angle of blade 30 with respect to fixed support 36 as trailing edge is raised and lowered by vertical elevator 38. However, a variation of this aspect could include flexible blade 30 integral with fixed support 36. The variation of the angle of the blade 30 in response to the movement of vertical elevator could be accommodated by the inherent flexibility of the blade.
FIG. 7A illustrates the two (or multiple) piece blade design. Blade 30 is composed of a forward section 42 and a rearward section 44. Seam 46 between forward section 42 and rearward section 44 is formed from an angled portion 46 extending from a downward extending portion of an undulation (with respect to the machine direction, so that the felt or liquid `not shown` does not urge the forward section 42 and the rearward section 44 apart) and a notched portion 48. The notched portion 48 is shown with a male portion in rearward section 44 and a female portion in forward section 42. The forward section 42 and the rearward section 44 are held together by bolts 51 (in phantom) or similar fastening devices. The lower portion of both forward section 42 and rearward section 44 include mounting slots 50 of a T-shaped cross section. Mounting slots 50 are used to engage mounting buttons 52 as shown in FIG. 8. Additionally, the lower portion of both forward section 42 and rearward section 44 include vent slots 53 of a T-shaped cross section. Vent slots 53 are in communication with vents 55 which are in communication with the troughs of the undulations of the upper surface of forward section 42 and rearward section 44. Vent slots 53 engage variable plug strips 57 which can be vertically adjusted either to align apertures 65 of variable plug strips 57 with vents 55 or to block vents 55 with solid portions of variable plug strips 57.
FIG. 7B shows ceramic inserts 62 at the apices of the undulations of blade 30 in a design otherwise similar to that shown in FIG. 7A.
FIG. 8 illustrates mounting button 52. Mounting button 52 includes a cylindrical stem 54 with a lower threaded portion 56. Upper circular cap 58 is integral with intermediate circular portion 59 and cylindrical stem 54. Washer 60 of a hollow cylindrical shape loosely engages intermediate circular portion 59 immediately below upper circular cap 58. As can be seen from the phantom lines in FIG. 8, the inner wall 62 of washer 60 is outward from intermediate circular portion 59 thereby allowing "play" between washer 60 and intermediate circular portion 59. Likewise, cylindrical stem 54 passes through central aperture 61 of cylindrical spacer bushing 63 which is downwardly adjacent from washer 60.
Mounting buttons 52 are secured to a frame (not shown) by lower threaded portions 56. Upper cylindrical cap 58 and washer 60 then engage the T-shaped mounting slots 50 (see FIG. 7A).
FIGS. 9A-9C illustrate a modular design with ceramic inserts 62 at the apices of the undulations of blade 30. Ceramic inserts 62 are supported by laterally grooved beams 64. Beams 64 include lateral grooves 66 which guide the trough portions 68 into place to form the modular composite blade 30.
Thus the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.
|
A papermaking apparatus such as a Fourdrinier table which includes a long blade and a trail blade. In the first aspect of the invention, the long blade includes an upper undulated surface with vents passing from the upper undulated surface to the lower surface of the long blade which is at substantially atmospheric pressure. In the second aspect of the invention, the trail blade includes an elevator-type device for adjusting the vertical position of the trail blade. In a third aspect of the invention, a single elevator is used to adjust the angle of the blade, the blade is provided as a modular or multiple-piece design, mounting buttons are used to engage slots of T-shaped cross section in the blade and/or ceramic inserts are included at wear points.
| 3
|
REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of priority of U.S. provisional application Ser. No. 61/083,026, filed Jul. 23, 2008, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to methods and compositions which are in a form randomly distributable upon a surface for emission of a chemiluminescent light which facilitates tracking of movements upon the surface, more particularly to a chemiluminescent system that may be pressure activatable to facilitate enabling one to detect whether any movement has breached an area during a certain time frame; and most particularly to compositions containing an infrared light generating chemiluminescent system, blended into an earthen-like carrier.
BACKGROUND OF THE INVENTION
[0003] Chemiluminscent systems are typically comprised of four active ingredients, an oxalate ester, hydrogen peroxide, a fluorescer, and a catalyst. Normally, these active ingredients are divided until time of use by placing the oxalate ester and dye in one solution that is packaged within a frangible glass ampoule. This sealed ampoule is then floated within a sealed flexible tube containing the hydrogen peroxide and catalyst in a second solution. To generate light, the user bends the flexible tube, breaking the frangible ampoule and allowing the two solutions to mix.
[0004] It is desirable to formulate a chemiluminescent system which is in a granular format that is dispersible upon a surface and which is dispersed in either an activated state, so that the act of moving along the surface results in a visible disruption of the light emission, or wherein one part of the chemistry is microencapsulated, such that the pressure of movement occurring upon the surface causes initiation of the light emission, to act as a visual track of the movement thereupon.
[0005] In accordance with the present invention, the same four active ingredients are utilized, but they are divided differently. In this instance, the hydrogen peroxide, fluorescer, and catalyst are combined within a soil colored solid matrix. At time of use, this combination is directly admixed with the oxalate ester for generation of light. Altering the oxalate ester by microencapsulating it delays the generation of light upon admixture, until the admix is stepped upon. The act of stepping on the admixture ruptures the microencapsulation around the oxalate ester and results in its interacting with the other active ingredients, initiating the chemiluminescent light generating reaction.
[0006] Often security forces need and desire to passively detect passage through various areas. Common methods to do this include removing all vegetation from outdoor areas and raking the ground into a smooth pattern. Any movement across the prepared area disturbs the smooth, raked pattern on the ground and allows for detection of the intrusion. The obvious problem with this is that the preparation of the ground by raking is obvious to all. Another problem with this method is that it is not suitable for indoor areas.
[0007] In accordance with the present invention, there has now been developed a method of preparing ground for intrusion detection that is suitable for indoor and outdoor use. This method is also covert in that the materials look like the normal contents of a floor or ground area. This new method utilizes chemiluminescent materials that have been modified to look like normal dirt or soil. In a particular embodiment, the fluorescer may be chosen so that only infrared light is produced by the chemiluminescent reaction, so that the light is only visualized by special filters, and therefore the intruders are not readily aware that they have left a covertly visible trail.
PRIOR ART
[0008] U.S. Pat. No. 4,771,724 to Baretz et al is directed toward a non-pyrotechnic lighting device whereby intrusion into a restricted area can be monitored and detected subsequent to the device having been triggered by an unsuspecting subject.
[0009] U.S. Pat. No. 5,770,116 to Byrne, Jr. teaches a kit comprising a chemiluminescent chemical capable of emitting visible light on contact with animal blood. Delivery of the composition to an area of terrain suspected of having blood deposits thereon results in emission of a luminescence enabling the hunter to recognize the presence of blood to assist in tracking a wounded game animal.
[0010] The prior art fails to teach a process or composition wherein an infrared emitting composition is formed which is capable of being spread upon an interior or exterior area, and which can be colored so as to camouflage its presence, so that an observer in possession of a device, such as a night vision eyepiece, capable of detecting light in the infrared portion of the spectrum, may visualize the telltale signs of intrusion in a covert manner.
SUMMARY OF THE INVENTION
[0011] The present invention relates to a chemiluminescent system which is provided in a granular format that is dispersible upon a surface and which is dispersed in either an activated state, so that the act of moving along the surface results in a visible disruption of the light emission, or wherein one part of the chemistry is microencapsulated, such that the pressure of movement occurring upon the surface causes initiation of the light emission, to act as a visual track of the movement thereupon. The formulation may be colored in such a manner as to blend or contrast with the surface upon which it is distributed. Dependent upon the judicious selection of fluorescers, the light generated by the formulation may be in either the visible or infrared spectrum, as is desirable.
[0012] In a particular embodiment, the present invention provides an earthen-like carrier that could be spread either indoors or outdoors on any type of walking surface where covert intrusion detection is desired. This substance will allow an observer to determine whether an intruder has breeched a surface by giving off a chemiluminescent light that can be seen by wearing night vision goggles. This will allow the observer to protect their property and detect the type of footsteps or tracks that passed through an area.
[0013] The chemiluminescent substance looks very similar to dirt or soil. Because the material looks like normal soil or dirt, it is not detectable to the naked eye. It also has the ability to camouflage itself by altering the ingredients when making the substance, depending upon what color soil or dirt is located on your property. This IR light emitting dark brown powder can be spread across a hallway, over stairs, or over any indoor area where covert intrusion detection is desired.
[0014] As will be described hereinafter, various types of chemiluminescent substances will be illustrated. These examples are merely illustrative and are not meant to limit the inventive concept in any way.
[0015] One type will emit IR light continuously for up to 5 days. It will, however, fade if exposed to UV light. If exposed to UV light, the color will fade from a dark brown to a bright orange.
[0016] Another type of chemiluminescent substance will not fade from UV light, and will continuously emit IR light for up to 3 days. Exposure to UV light (sunlight) will result in a slight change in color or shade from a dark brown to a lighter brown. However, both the before and after states continue to look like normal soil or dirt.
[0017] Accordingly, it is a primary objective of the instant invention to provide a means for intrusion detection based upon an IR emitting chemiluminescent system incorporated within or upon an earthen-like carrier material.
[0018] It is a further objective of the instant invention to provide an intrusion detection system based upon an IR emitting chemiluminescent system which will not undergo substantial color change when exposed to ultra-violet light.
[0019] It is yet another objective of the instant invention to provide a process for covert intrusion detection by distribution of an IR emitting chemiluminescent system incorporated within or upon an earthen-like carrier material upon an area to be monitored.
[0020] It is an additional objective of the instant invention to provide a dispersible formulation which may actively produce light of any spectrum desirable when distributed or which may be in the form of a pressure-activated chemiluminescent reaction system, from which light emission ensues when the material is stepped upon.
[0021] Other objects and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0022] FIG. 1 illustrates an area which has been dusted with the covert intrusion composition, being observed for signs of intrusion.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Typical chemical light systems employ four active ingredients, an oxalate ester, hydrogen peroxide, a fluorescer, and a catalyst. Usually, these active ingredients are divided until time of use by placing the oxalate ester and dye in one solution that is packaged within a frangible glass ampoule. This sealed ampoule is then floated within a sealed flexible tube containing the hydrogen peroxide and catalyst in a second solution. To generate light, the user bends the flexible tube, breaking the frangible ampoule and allowing the two solutions to mix.
[0024] In accordance with the present invention, the same four active ingredients are utilized, but they are divided differently. In this instance, the hydrogen peroxide, fluorescer, and catalyst are combined within a soil colored solid matrix. At time of use, this combination is directly admixed with the oxalate ester.
[0025] It is desirable to formulate a chemiluminescent system which is in a granular format that is dispersible upon a surface and which is dispersed in either an activated state, so that the act of moving along the surface results in a visible disruption of the light emission, or wherein one part of the chemistry is microencapsulated, such that the pressure of movement occurring upon the surface causes initiation of the light emission, to act as a visual track of the movement thereupon.
[0026] Therefore, the present invention teaches an illustrative, albeit non-limiting method for forming an immobilized and colored chemiluminescent material useful for indoor or outdoor intrusion detection comprising the steps of providing a colorable absorbent media, along with one or more dyes selected to provide a desirable coloration to the color absorbent media; forming an aqueous coloring solution including an effective amount of one or more of the dyes; combining the colorable absorbable media and the aqueous coloring solution to form a paste having a desirable color; drying the paste to less than about 5% water by weight; forming a first reactant composition including an effective amount of a fluorescer and a solvent therefore; adding the first reactant composition to the paste; forming a second reactant composition including an effective amount of a peroxide, a catalyst and a solvent therefore; adding the second reactant composition to the paste containing the first reactant composition; and adding, at a desired time of use, an effective amount of an oxalate ester. This process results in the production of a chemiluminescent light emitting intrusion detection composition suitable for indoor or outdoor use is formed.
[0027] The composition can be provided in any desirable color. When the end use is for covert intrusion detection, a desirable coloration resembles normal soil or dirt, so as to camouflage the material. Further, when utilizing covert intrusion, the choice of fluorescer is selected for production of infrared light whereby covert intrusion detection is enabled. In an alternative embodiment, activation of the chemiluminescent system can be delayed and take the form of a pressure or contact initiated reaction by microencapsulation of the oxalate ester.
[0028] When it is desired to maintain the covert nature of the subject invention, the fluorescer is chosen so that it emits light only in the infrared portion of the spectrum. Light will be generated immediately when the unaltered oxalate ester is directly admixed with the soil colored solid matrix. This has great utility in indoor areas where, due to lack of windows or other openings (i.e. stairwells or basements), there is no light for Night Vision Goggles to intensify. The infrared emission of the subject invention generates enough covert light so that wearers of Night Vision Goggles can readily see.
[0029] Altering the oxalate ester by microencapsulating it delays the generation of light upon admixing with the soil colored solid matrix until the admix is stepped upon. The act of stepping on the admixture ruptures the microencapsulation around the oxalate ester and results in its interacting with the other active ingredients, initiating the chemiluminescent light generating reaction. This has particular utility in outdoor areas where knowing if the area has been crossed and which direction the persons crossing the area were going have utility (i.e. such as borders).
[0030] The above products and processes are useful in practicing a process for intrusion detection which comprises providing a light emitting chemiluminescent colored composition adapted to blend in with the surroundings upon which it is placed, and observing the emissions of the light emitting chemiluminescent colored composition for signs of disturbance by an intruder, whereby intrusion is detected.
[0031] Fluorescers useful in the present invention include but are not limited to 1-methoxy-9,10-bis(phenylethynyl)anthracene, perylene, rubrene, 16,17-didecycloxyviolanthrone, 2-ethyl-9,10-bis(phenylethynyl)anthracene; 2-chloro-9,10-bis(4-ethoxyphenyl)anthracene; 2-chloro-9,10-bis(4methoxyphenyl)anthracene; 9,10-bis(phenylethynyl)anthracene; 1-chloro-9,10-bis(phenylethynyl)anthracene; 1,8-dichloro-9,10-bis(phenylethynyl)anthracene; 1,5-dichloro-9,10-bis(phenylethynyl)anthracene; 2,3-dichloro-9,10-bis(phenylethynyl)anthracene; 5,12-bis(phenylethynyl)tetracene; 9,10-diphenylanthracene; 1,6,7,12-tetraphenoxy-N,N′-bis(2,6-diisopropylphenyl)-3,4,9,10-perylene dicarboximide; 1,6,7,12-tetraphenoxy-N,N′-bis(2,5-di-t-butylphenyl)-3,4,9,10-perylene dicarboximide; 1,7-di-chloro-6,12-diphenoxy-N,N′-bis(2,6-diisopropylphenyl)-3,4,9,10-perylene dicarboximide; 1,6,7,12-tetra(p-bromophenoxy)-N,N′-bis(2,6-diisopropylphenyl)-3,4,9,10-perylene dicarboximide; 1,6,7,12-tetraphenoxy-N,N′-di-neopentyl-3,4,9,10-perylene dicarboximide; 1,6,7,12-tetra(p-t-butylphenoxy)N,N′-dineopentyl-3,4,9,10-perylene dicarboximide; 1,6,7,12-tetra(o-chlorophenoxy)-N,N′-bis(2,6-diisopropylphenyl)-3,4,9,10-perylene dicarboximide; 1,6,7,12-tetra(p-chlorophenoxy)-N,N′-bis(2,6-diisopropylphenyl)-3,4,9,10-perylene dicarboximide; 1,6,7,12-tetra(o-fluorophenoxy)-N,N′-bis(2,6-diisopropylphenyl)-3,4,9,10-perylene dicarboximide; 1,6,7,12-tetra(p-fluorophenoxy)-N,N′bis(2,6-diisopropylphenyl)-3,4,9,10-perylene dicarboximide; 1,6,7,12-tetraphenoxy-N,N′-diethyl-3,4,9,10-perylene dicarboximide; 1,7-dibromo-6,12-diphenoxy-N,N′-bis(2-isopropylphenyl)-3,4,9,10-perylene dicarboximide; 16,17-dihexyloxyviolanthrone; rubrene; and 1,4-dimethyl-9,10-bis(phenylethynyl)anthracene.
[0032] Catalysts useful in the present invention include but are not limited to sodium salicylate; sodium-5-fluorosalicylate; sodium-5-chlorosalicylate; sodium-5-bromosalicylate; sodium trifluoroacetate; potassium salicylate; potassium pentachlorophenolate; lithium salicylate; lithium-3-chlorosalicylate; lithium-5-chlorosalicylate; lithium-3,5-dichlorosalicylate; lithium-3,5,6-trichlorosalicylate; lithium-2-chlorobenzoate; lithium-5-t-butylsalicylate; lithium trifluoroacetate; rubidium acetate; tetrabutylammonium salicylate; tetrabutylammonium tetrafluoborate; tetraethylammonium benzoate; tetrabutylammonium benzoate; tetrabutylammonium hexafluorophosphate; tetraethylammonium perchlorate; tetrabutylammonium perchlorate; tetraoctylammonium perchlorate; tetrabutylammonium-2,3,5-trichlorobenzoate; tetramethylammonium trifluoroacetate; magnesium salicylate; magnesium-5-t-butyl-salicylate; magnesium-3-chlorosalicylate; magnesium-3,5-dichloro-salicylate; and magnesium-3,5,6-trichlorosalicylate.
[0033] Oxalates useful in the present invention include but are not limited to bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate; bis(2,4,5-trichlorophenyl)oxalate; bis(2,4,5-tribromo-6-carbohexoxyphenyl)oxalate; bis(2-nitrophenyl)oxalate; bis(2,4-dinitrophenyl)oxalate; bis(2,6-dichloro-4-nitrophenyl) oxalate; bis(2,4,6-trichlorophenyl)oxalate; bis(3-trifluoromethyl-4-nitrophenyl)oxalate; bis(2-methyl-4,6-dinitrophenyl)oxalate; bis(1,2-dimethyl-4,6-dinitrophenyl)oxalate; bis(2,4-dichlorophenyl)oxalate; bis(2,4-dinitrophenyl)oxalate; bis(2,5-dinitrophenyl)oxalate; bis(2-formyl-4-nitrophenyl)oxalate; bis(pentachlorophenyl)oxalate; bis(1,2-dihydro-2-oxo-1-pyridyl)glyoxal; bis(2,4-dinitro-6-methylphenyl)oxalate; and bis-N-phthalimidyl oxalate.
[0034] Peroxides useful in the present invention include but are not limited to hydrogen peroxide; sodium peroxide; sodium perborate; sodium pyrophosphate peroxide; urea peroxide; histidine peroxide; t-butyl-hydroperoxide; and peroxybenzoic acid.
[0035] Dyes useful in the present invention include but are not limited to water soluble dyes such as Brown HT; Quinoline Yellow; Indigo Carmine; Brilliant Blue FCF; Ponceau 4R; Sunset Yellow; Indigotine; Fast Green FCF; Alura Red AC.
[0036] Oxalate solvents useful in the present invention include, but are not limited to a propylene glycol dialkyl ether containing one to three propylene moieties and each alkyl group is independently a straight-chain or branched-chain alkyl group containing up to 8 carbon atoms. Especially preferred first solvents are propylene glycol dialkyl ethers containing two propylene moieties such as dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether and dipropylene glycol di-t-butyl ether. The particularly preferred first solvent comprises dipropylene glycol dimethyl ether, dibutyl phthalate, butyl benzoate, propylene glycol dibenzoate, and ethyl-hexyl diphenyl phosphate.
[0037] Activator solvents useful in the present invention include, but are not limited, to dimethyl phthalate, triethyl citrate, and ethylene glycol dibenzoate.
EXAMPLE 1
[0038] In one illustrative embodiment, about 0.15 grams of Brown HT dye were dissolved in about 35 grams of water. This colored solution was then added to about 85 grams of corn starch. The resulting brown colored paste was oven dried to less than about 5% water (by weight). Subsequently, about 0.0211 grams of didecycloxyviolanthrone were dissolved in about 14 grams of propylene glycol dibenzoate, and were added to the brown, dried corn starch. About 1.7 grams of 50% hydrogen peroxide were then mixed with about 14 grams of triethyl citrate, and added to the brown, dried corn starch mixture. The resulting product can now be admixed with about 4 grams of bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate at the desired time of use to make an infrared light emitting dark brown powder that looks like ordinary soil or dirt.
[0039] As illustrated in FIG. 1 , the IR light emitting dark brown powder 10 can be spread across a hallway, over stairs, or over any indoor area where covert intrusion detection is desired. Because the material looks like normal soil or dirt, it is not detectable to the naked eye. However, with Night Vision Goggles 30 , the material is readily seen as a glowing surface that easily shows disturbances, such as footsteps 20 . This material is suitable for indoor spaces and if protected from UV light (sunlight), will emit IR light continuously for up to 5 days. Exposure to UV light will result in “bleaching” and the material will change in color or shade from a dark brown to a bright orange.
EXAMPLE 2
[0040] In an alternative illustrative embodiment, about 0.15 grams of Brown HT dye, about 0.026 grams of Red Dye #40, about 0.025 grams of Yellow Dye #5, and about 0.179 grams of Blue Dye #2 were dissolved in about 35 grams of water. This colored solution was then added to about 85 grams of corn starch. The resulting brown colored paste was then oven dried to less than about 5% water (by weight). About 0.042 grams of didecycloxyviolanthrone were then dissolved in about 14 grams of propylene glycol dibenzoate, and added to the brown, dried corn starch. Subsequently, about 1.7 grams of 50% hydrogen peroxide were mixed with about 14 grams of triethyl citrate, and added to the brown, dried corn starch mixture. The resulting product can now be admixed with about 4 grams of bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate at the desired time of use to make an infrared light emitting dark brown powder that looks like ordinary soil or dirt.
[0041] This IR light emitting dark brown powder can be spread across any outdoor space where covert intrusion detection is desired. Because the material looks like normal soil or dirt, it is not detectable to the naked eye. However, with Night Vision Goggles, the material is readily seen as a glowing surface that easily shows disturbances (such as footsteps). This material is suitable for outdoor spaces and does not require protection from UV light (sunlight). It will emit IR light continuously for up to 3 days. Exposure to UV light (sunlight) will result in a slight change in color or shade from a dark brown to a lighter brown, however, both the before and after states continue to look like normal soil or dirt.
EXAMPLE 3
[0042] In another illustrative embodiment, about 0.15 grams of Brown HT dye are dissolved in about 35 grams of water. The colored solution, thus formed, is added to about 85 grams of corn starch. The resulting brown colored paste is oven dried to less than about 5% water (by weight). Next, dissolve about 0.0211 grams of didecycloxyviolanthrone in about 14 grams of propylene glycol dibenzoate. Add this to the brown, dried corn starch. Next, mix about 1.7 grams of 50% hydrogen peroxide with about 14 grams of triethyl citrate. Add this to the brown, dried corn starch mixture. The resulting product can now be admixed with about 4 grams of microencapsulated bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate at the desired time of use to make an infrared light emitting dark brown powder that looks like ordinary soil or dirt. The bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate can be microencapsulated by slurrying it in a variety of suitable encapsulating agents, for example, within a solution of polyvinyl butyrate dissolved in ethanol, subsequent to which the slurry is spray dried, after which the ethanol is allowed to flash off and harden the polyvinyl butyrate and form a coating over the bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate. This powder can be spread upon the ground and will emit light after being stepped upon.
[0043] The dark brown powder can be spread across a hallway, over stairs, or over any indoor area where covert intrusion detection is desired. Because the material looks like normal soil or dirt, it is not detectable to the naked eye. However, with Night Vision Goggles, the pressure-activated chemiluminescent reaction which ensues when the material is stepped upon, is readily seen as a glowing disturbance (such as footsteps) within a non-glowing area.
[0044] This material is suitable for indoor spaces and if protected from UV light (sunlight), will emit IR light continuously for up to 5 days, subsequent to activation. Exposure to UV light will result in “bleaching” and the material will change in color or shade from a dark brown to a bright orange.
EXAMPLE 4
[0045] In yet an additional illustrative embodiment, first dissolve about 0.15 grams of Brown HT dye, about 0.026 grams of Red Dye #40, about 0.025 grams of Yellow Dye #5, and about 0.179 grams of Blue Dye #2 in about 35 grams of water. Add this colored solution to about 85 grams of corn starch. Oven dry the resulting brown colored paste to less than about 5% water (by weight). Dissolve about 0.042 grams of didecycloxyviolanthrone in about 14 grams of propylene glycol dibenzoate. Add this to the brown, dried corn starch. Mix about 1.7 grams of 50% hydrogen peroxide with about 14 grams of triethyl citrate. Add this to the brown, dried corn starch mixture. The resulting product can now be admixed with about 4 grams of microencapsulated bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate at the desired time of use to make a dark brown powder that looks like ordinary soil or dirt. The bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate can be microencapsulated by slurrying it within molten paraffin and then spray drying the slurry and allowing the molten paraffin to harden and form a coating over the bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate. This powder can be spread upon the ground and will emit light after being stepped upon.
[0046] This IR light emitting dark brown powder can be spread across any outdoor space where covert intrusion detection is desired. Because the material looks like normal soil or dirt, it is not detectable to the naked eye. However, with Night Vision Goggles, the pressure-activated chemiluminescent reaction which ensues when the material is stepped upon, is readily seen as a glowing disturbance (such as footsteps) within a non-glowing area.
[0047] This material is suitable for outdoor spaces and does not require protection from UV light (sunlight). It will emit IR light continuously for up to 3 days after being stepped upon. Exposure to UV light (sunlight) will result in a slight change in color or shade from a dark brown to a lighter brown. However, both the before and after states continue to look like normal soil or dirt.
[0048] All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
[0049] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
[0050] One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
|
This invention is directed towards chemiluminescent systems useful in the practice of methods of intrusion detection, compositions useful for intrusion detection and methods for their formation, and to covert intrusion detection techniques and compositions therefore containing an infrared light generating chemiluminescent system, blended into an earthen-like carrier that enable one to detect whether any movement has breached an area during a certain time frame.
| 2
|
BACKGROUND
[0001] The present invention relates generally to the field of bicycles and specifically to bicycle frames that can be converted from a dropout adapted to receive a wheel axle of one size to a wheel axle of a different size.
[0002] Bicycles are available in a variety of different wheel sizes. For example, wheels can be designated with diameters of 26 inch, 27 inch, or 700 mm. In addition, wheels can come with different-sized axles having lengths such as 135 mm or 140 mm and diameters of 10 mm or 12 mm.
[0003] It is often desirable to convert a bicycle frame from accommodating a wheel of one size to a wheel of another size. For example, it might be desirable to convert a frame from receiving a rear wheel with a 135 mm axle spacing to a wheel with a 140 mm axle spacing.
SUMMARY
[0004] The present invention provides a bicycle that includes a frame that is specifically design to accommodate wheel of different axle configurations. Specifically, the bicycle includes a wheel including a wheel axle and a bicycle frame supported by the wheel. The frame includes a wheel support coupled to the wheel, and the wheel support includes an axle opening (e.g., extending laterally through the wheel support) having a first width and an axle slot contiguous with the axle opening and having a second width that is less than the first width. Preferably, a portion of the wheel axle positioned in the axle opening has a diameter that substantially matches the first width (e.g., the axle fits snugly into the axle opening).
[0005] In one embodiment, the wheel axle extends substantially all the way through the axle opening in the wheel support. In another embodiment, the bicycle further includes a converter at least partially positioned in the axle opening, the converter engaging at least a portion of the wheel axle. For example, the converter can include a flange positioned in the axle opening and defining an axle receiving area contiguous with the axle slot and having a third width that substantially matches the second width. Preferably, the converter includes an alignment feature for aligning the converter relative to the wheel support.
[0006] The present invention also provides a method of changing an original wheel of a bicycle. The bicycle includes a frame including a wheel support having an axle opening with a first width, at least a portion of an original axle being positioned in the axle opening. The wheel support further including an axle slot contiguous with the axle opening, the axle slot having a second width that is less than the first width. The method comprises removing the original wheel from the wheel support, positioning a converter at least partially in the axle opening (the converter defining an axle receiving area contiguous with the axle slot and having a third width smaller than the first width and preferably substantially matching the second width), providing a replacement wheel having a replacement hub that has a replacement axle, and sliding the replacement axle through the axle slot and into the receiving area defined by the converter.
[0007] In one embodiment, the axle opening extends laterally through the wheel support, and the step of removing the original wheel includes sliding the original axle laterally out of the axle opening. Preferably, the converter includes a first alignment feature and the wheel support includes a second alignment feature, and wherein the step of positioning the converter includes aligning the first alignment feature with the second alignment feature. After sliding the replacement axle, the method can further include the step of compressing the wheel support against the replacement hub (e.g., by inserting a skewer through the replacement axle and tightening the skewer).
[0008] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a side view of a bicycle embodying the present invention.
[0010] FIG. 2 is an exploded right perspective view of a first configuration of a rear wheel support for the bicycle of FIG. 1 .
[0011] FIG. 3 is an exploded left perspective view of the first configuration.
[0012] FIG. 4 is a right rear perspective view of a rear portion of the frame of FIG. 2 .
[0013] FIG. 5 is a left rear perspective view of a rear portion of the frame of FIG. 2 .
[0014] FIG. 6 is a vertical section view of the assembled first configuration of FIGS. 2-3 .
[0015] FIG. 7 is an exploded right perspective view of a second configuration of a rear wheel support for the bicycle of FIG. 1 .
[0016] FIG. 8 is an exploded left perspective view of the second configuration.
[0017] FIG. 9 is a vertical section view of the assembled second configuration of FIGS. 7-8 .
DETAILED DESCRIPTION
[0018] Before any embodiments of the invention are explained in detail, it is to be understood that the 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 following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
[0019] FIG. 1 illustrates a bicycle 10 having front and rear wheels 12 , 14 , a frame 16 supported on the rear wheel 14 , a front fork 18 supported on the front wheel 12 , a seat 20 , handlebars 22 , and a rear derailleur 23 as is generally known in the art. Referring to FIG. 2 , the rear wheel 14 includes a hub 24 that is mounted to left and right wheel supports 26 , 28 (commonly called dropouts) on a rear portion of the frame 16 . The wheel supports 26 , 28 of the illustrated frame 16 are designed to accommodate hubs having at least two different configurations. A first hub 24 having a first configuration is illustrated in FIGS. 2-6 , and a second hub 30 having a second configuration is illustrated in FIGS. 7-9 .
[0020] Referring to FIGS. 2-5 , the first hub 24 includes a first body 32 rotationally mounted on a main axle 34 by two wheel bearings 36 . Left and right spacers 38 , 40 fit over the ends of the main axle 34 to achieve an overall hub width W1, which in the illustrated embodiment is about 135 mm. Each of the spacers 38 , 40 includes a spacer diameter D, which in the illustrated embodiment is about 19 mm.
[0021] The left wheel support 26 ( FIGS. 2 and 4 ) includes a left hub slot 42 formed on an inner face of the left wheel support 26 . The left hub slot 42 is dimensioned to receive the left spacer 38 of the first hub 24 . The outer surface of the left wheel support ( FIGS. 3 and 5 ) includes a cylindrical recess 44 terminating in a frusto-conical wall 46 . A left axle opening 48 extends through the left wheel support and has a width (diameter) of about 12 mm. An alignment recess 50 ( FIG. 4 ) also extends through the left wheel support 26 and is contiguous with the left axle opening 48 . The inner face of the left wheel support 26 further includes a left axle slot 52 contiguous with the left axle opening 48 . The left axle slot 52 extends only partially into the inner face of the left wheel support 26 , and has a width of about 10 mm.
[0022] The right wheel support 28 includes an inner face ( FIGS. 3 and 5 ) having a recess 54 dimensional to receive a derailleur hanger. The right wheel support 28 further includes a hanger mount hole 58 extending laterally all the way through the right wheel support 28 . The right wheel support 28 further includes a threaded right axle opening 60 extending all the way through the right wheel support 28 and having a width (diameter) of about 12_ mm. A right axle slot 62 is formed in the inner face of the right wheel support 28 and is contiguous with the right axle opening 60 . The illustrated right axle slot 62 extends only partially into the right wheel support 28 and has a width of about 10 mm.
[0023] When it is desired to insert the above-described first hub 24 into the wheel supports 24 , 28 of the frame 16 , the frame 16 is first provided with a closed hanger 64 ( FIG. 3 ) on the right wheel support 28 . More specifically, the closed hanger 64 is positioned in the recess 54 on the inner face of the right wheel support 28 , and a hanger attachment bolt 66 is inserted through the hanger mount hole 58 of the right wheel support 28 and threaded into a threaded opening 68 in the closed hanger 64 . In this manner, the closed hanger 64 is secured to the inner face of the right wheel support 28 . The closed hanger 64 includes a hanger opening 70 having a width (diameter) of about 12 mm that is aligned with the right axle opening 60 when the closed hanger 64 is secured in the recess 54 of the right wheel support 28 . The closed hanger 64 further includes a lip 72 extending partially circumferentially around the hanger opening 70 . The closed hanger 64 further includes a threaded derailleur mount hole 74 configured to receive the rear derailleur 23 , as is known in the art. The closed hanger 64 further includes a ramped surface 76 that guides the first hub 24 into the closed hanger 64 , as described below in more detail.
[0024] A through-axle assembly is provided to secure the first hub 24 to the wheel supports 26 , 28 . The through-axle assembly includes a split plug 78 , a washer 82 , and a through axle 84 having a threaded end 86 . All three parts of the through-axle assembly are retained in an assembled condition due to a lip on the split plug 78 that engages a groove in the head of the through axle 84 , as shown in FIG. 6 .
[0025] In order to mount the first hub 24 between the left and right wheel supports 26 , 28 , the first hub 24 is arranged such that the left spacer 38 is aligned with the left hub slot 42 and the right spacer 40 is aligned with the ramped surface 76 on the closed hanger 64 . The first hub 24 is then moved upward until the left spacer 38 is fully seated in the left hub slot 42 and aligned with the left axle opening 48 and the right spacer 40 is fully seated into engagement with the lip 72 and aligned with the hanger opening 70 . With the first hub 24 held in this position, the through axle assembly 80 , 82 , 84 is inserted through the left axle opening 48 , through the first hub 24 , through the hanger opening 70 , and threaded into the right axle opening 60 . The through axle 84 has a diameter of about 12 mm to substantially match (e.g., slide snugly through) the diameter of the left axle opening 48 . Tightening of the through axle 84 in this position results in the first hub 24 being secured to the frame 16 .
[0026] When it is desired to instead use the second hub 30 , the first hub 24 is removed from the frame 16 by removing the through axle assembly 80 , 82 , 84 , and sliding the first hub 24 out through the left hub slot 42 and closed hanger 64 . A converter plug 88 is inserted into the recess 44 in the left wheel support 26 , and the closed hanger 64 is replaced with an open hanger 90 . The converter plug 88 includes a cylindrical surface 92 and a frusto-conical surface 94 that are dimensioned to fit into the recess 44 in the outer face of the left wheel support 26 . The converter plug 88 further includes a skewer opening 96 extending through the converter plug 88 , and a flange 98 extending partially circumferentially around the skewer opening 96 . The flange 98 is dimensioned to fit into the left axle opening 48 and defines an axle receiving area having a width that substantially matches the width of the left axle slot 52 . The flange 98 is provided with an alignment boss 100 that is dimensioned to be received in the alignment recess 50 .
[0027] The open hanger 90 includes a hanger slot 102 having a width that substantially matches the width of the right axle slot 62 . The open hanger 90 further includes ramped surfaces 104 on opposing sides of the hanger slot 102 . When being configured to receive the second hub 30 , a converter nut 106 is inserted through the outer face of the right wheel support 28 and into the right axle opening 60 . The converter nut 106 includes a partially threaded opening 108 extending all the way through.
[0028] The second hub 30 includes a main axle 110 and bearings (now shown) similar to the embodiment of FIGS. 2-6 . However, the left and right spacers 111 of this second hub 30 include small-diameter ends 112 that extend outward. The width W2 of the second hub 30 , not including the small-diameter ends 112 , is about 135 mm. In order to mount the second hub 30 to the frame 16 , the left and right ends 112 of the small axle 110 are aligned with the left and right axle slots 52 , 62 , respectively. It is noted that the hanger slot 102 is aligned with the right axle slot 62 , and therefore the right end 112 of the axle 110 will also be aligned with the hanger slot 102 . The second hub 30 is then moved upward so that the left and right ends 112 of the small axle 110 slide through the corresponding slots until the left end 112 of the small axle 110 is fully seated into the flange 98 of the converter plug 88 and the right end 112 of the small axle 110 is fully seated into the end of the hanger slot 102 . With the parts properly aligned, a skewer rod 114 inserted through the converter plug 88 , through the small axle 110 , and into the converter nut 106 . The skewer rod 114 is threaded into the converter nut 106 to the desire a mount, and a skewer cam 116 rotated to compress the wheel supports 26 , 28 to the second hub 30 , as is generally known in the art.
[0029] Various features of the invention are set forth in the following claims.
|
The present invention provides a bicycle that includes a frame that is specifically design to accommodate different axle configurations. The bicycle includes a wheel including a wheel axle and a bicycle frame comprising a wheel support including an axle opening having a first width and an axle slot contiguous with the axle opening and having a second width less than the first width. Preferably, a portion of the wheel axle positioned in the axle opening has a diameter that substantially matches the first width. The present invention also provides a method of changing an original wheel of a bicycle. The method comprises removing the original wheel from the wheel support, positioning a converter in the axle opening, providing a replacement wheel having a replacement hub that has a replacement axle, and sliding the replacement axle through the axle slot and into the receiving area defined by the converter.
| 8
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.