description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the games of billiards, pool and snooker, and more particularly to an apparatus for tightly setting and arranging billiard, pool or snooker balls on the surface of a playing table.
2. Description of the Prior Art
In the games of billiards, pool, and snooker, the playing balls are arranged in a pre-determined pattern at the start of the game. In the game of pool, for example, fifteen balls are arranged in a triangular pattern using a triangular shaped frame known as a rack. The balls are placed in a triangular formation at a given spot on the playing surface, and the rack is removed. Once the rack is removed from the balls, the formation is broken by a player propelling a cue ball in such a manner as to disperse the formation of balls across the playing surface. The way in which the formation of balls is broken is of utmost importance to how the ensuing game progresses. It is very desirable to compact the formation of balls such that they are set tightly together. The act of compacting the formation of balls such that they are set tightly together is commonly known as “tightening”. This technique allows for the maximum transfer of energy from the cue ball to the balls in formation, and provides a disperse spread of balls across the playing surface. There are various techniques used to compact the formation of balls contained by the rack, the simplest being the use of a player's fingers to push the balls forward in the rack once the balls are contained by the rack. The problem with this technique is with the adhesion that occurs between a player's fingers and the playing balls. The surface adhesion that momentarily occurs when a player removes their fingers from the playing balls serves to disturb the compact formation of balls within the rack. Another problem occurs when the rack is removed from the formation of balls. Upon removal of the rack from a compact formation of balls, there exists the possibility that the rack inadvertently comes into contact with one or more of the playing balls and disturbs the previously compact formation of balls. Such a disturbance can negatively impact the breaking of the formation, or can further result in resetting and retightening the formation prior to the start of play.
The prior art has disclosed various techniques for creating a compact formation of playing balls using various means to tighten the playing balls. Reference may be had, e.g., to U.S. Pat. No. 3,672,671 that uses inclined walls within the rack to create downward pressure on the playing balls. Reference may also be had to U.S. Pat. No. 6,595,862 that uses similar inclined walls within the rack to create downward pressure on the playing balls, and further uses lifting levers to ensure that the compact formation of playing balls is not disturbed upon removal of the rack. U.S. Pat. Nos. 5,601,495 and 5,735,750 further use inclined walls to create downward pressure on the playing balls, and use springs to push the rack upward and away from the playing balls once the formation is compacted. U.S. Pat. No. 5,556,341 uses angled packing bars to create downward pressure on the playing balls. There further exists U.S. Pat. No. 5,997,404 that discloses the use of individual pressure pins to create downward pressure on each individual playing ball. Each of these referenced United States Patents describe the use of downward pressure to press the playing balls into the felt of the playing surface. The use of downward pressure of the playing balls into the felt of the playing surface causes wear and fatigue of the playing surface felt, resulting in a playing surface with uneven ball rolling characteristics and premature failure and subsequent replacement of the felt playing surface. The present invention improves upon the attributes of the prior art compression racks by using horizontal pressure to compact the arrangement of playing balls, thus eliminating concerns over the wear and fatigue of the felt of the playing surface.
Reference may further be had to U.S. Pat. No. 3,992,005 that discloses a rack that uses horizontal pressure to compact the playing balls. The rack disclosed uses a ball and socket arrangement such that one corner of the rack triangle pops open upon insertion of the last ball. A problem with such a ball and socket release mechanism is one of vibration whereas the potential exists for the playing balls to be disturbed as the one corner of the rack triangle pops open automatically. Another problem with the use of horizontal compression from a single geometric plane, as described in U.S. Pat. No. 3,992,005 arises from the potential lack of size uniformity of the playing balls, as described in U.S. Pat. No. 5,997,404: “Unfortunately, the size of the pool balls often lacks uniformity, which makes it difficult to properly rack the balls into a tight formation.” The present invention solves the aforementioned problems by using slide mechanisms to reduce the length of the sides of the rack, and thus apply horizontal compression in both horizontal geometric planes, therefore compensating for any variation in ball size. The present invention further employs a hinge and slide mechanism to completely open one side of the rack, without any risk of disturbing the compacted playing ball formation.
The prior art references cited above use various mechanical means to compress the formation of balls within the rack. A further drawback to the prior art is the resulting shape of the rack. There are many devices in use today to retain and store a standard rack. These devices include retainers for securing racks in a commercial pool hall, holders for retaining accessories such as cue sticks, racks, chalk, and balls, carrying cases for racks, and the like. Many of the racks referenced in the prior art have a shape that does not conform to the shape of a typical rack. This precludes the use of such prior art racks with most rack retention and storage devices. The present invention conforms to the geometry of a typical rack, thus allowing the use of the present invention with most rack retention and storage devices.
It is an object of the present invention to provide an improved rack for compacting a formation of playing balls using horizontal pressure.
It is another object of the present invention to provide an improved rack for compacting a formation of playing balls and allowing for removal of said rack without disturbing the formation of playing balls.
It is another object of the present invention to provide an improved rack for compacting a formation of playing balls whereas the improved rack fits in a standard rack holder or rack slot such as the rack holders or rack slots found in billiard halls.
These and other objects of the invention will be apparent from the discussion appearing in the remainder of this specification.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an apparatus for arranging and compacting a plurality of balls into a predetermined pattern comprising a frame with a first side wall, a second side wall and a third side wall, and a slide mechanism attached to at least one side wall for changing the length of at least one side wall.
In using the present invention, one places a plurality of balls within the confines of said apparatus and reduces the length of at least one side wall by pushing at least one side wall toward the plurality of balls such that the plurality of balls are arranged and compacted into a predetermined pattern. The apparatus uses horizontal compression along both the x-axis and the y-axis to create a tight grouping of playing balls. The use of horizontal compression in place of the more common vertical compression racks provides a tighter grouping of playing balls and also reduces wear, fatigue and subsequent failure of the playing surface.
One embodiment of the present invention may include a slideable hinge mechanism pivotally attached to at least one side wall to allow at least one side wall to be raised above the height of said plurality of balls. By raising at least one side wall above the height of the plurality of balls, the apparatus may be slid away from the compact grouping of balls without disturbing the compact grouping of balls.
Another embodiment of the present invention may include tabs to facilitate hand retention of said apparatus.
Other features and advantages of the present invention will become apparent from the following more detailed description provided with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described by reference to the following drawings, in which like numerals refer to like elements, and in which:
FIG. 1 is a perspective view of a ball setting and tightening rack according to one embodiment of the present invention;
FIG. 2 is an exploded view of a ball setting and tightening rack according to one embodiment of the present invention;
FIG. 2A is an exploded broken-away view of a ball setting and tightening rack according to another embodiment of the present invention;
FIG. 2B is another exploded view of the ball setting and tightening rack of FIG. 2A ;
FIG. 3 illustrates the use of a ball setting and tightening rack according to one embodiment of the present invention;
FIG. 4 is a top plan view of a ball setting and tightening rack according to one embodiment of the present invention;
FIG. 5 is a side elevation view of a ball setting and tightening rack shown in the open position for release of playing balls;
FIG. 6 is a rear elevation view of a ball setting and tightening rack according to one embodiment of the present invention;
FIG. 7 is a perspective view of a ball setting and tightening rack according to another embodiment of the present invention;
FIG. 8 is a top plan view of a ball setting and tightening rack of FIG. 7 in use, according to another embodiment of the present invention;
FIG. 9 is a side elevation view of a ball setting and tightening rack of FIG. 7 , according to another embodiment of the present invention;
FIG. 10 is an end elevation view of a ball setting and tightening rack of FIG. 7 , according to another embodiment of the present invention.
The present invention will be described in connection with a preferred embodiment, however, it will be understood that there is no intent to limit the invention to the embodiment described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For a general understanding of the present invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate identical elements. As shown in the drawings for purposes of illustration, the present invention is directed to a billiard ball rack for tightly setting and arranging a formation of billiard balls on a playing table. For the purposes of illustration, the drawings illustrate a 15 ball billiard rack, however the spirit and scope of the present invention includes variations of the game of billiards such as 9 ball, snooker, pool, and the like.
FIG. 1 is a perspective view of a ball setting and tightening rack according to one embodiment of the present invention. Referring to FIG. 1 , a rack assembly 100 is shown. The rack assembly 100 is made of a plurality of side walls that form a geometric shape such as a triangle. A compound side wall 133 makes up the first side wall and the second side wall of the triangular shaped rack 100 . A first partial side wall 101 and a second partial side wall 103 are connected to form the third side wall of the triangular shaped rack 100 . The first partial side wall 101 and the second partial side wall 103 further contain slide mechanisms to reduce the inner area of the rack assembly 100 and thus tighten the formation of playing balls placed within said rack assembly 100 .
Referring now to FIG. 2 , an exploded view of a ball setting and tightening rack according to one embodiment of the present invention is shown. The compound side wall 133 makes up two of the three sides of the rack assembly 100 . The compound side wall 133 is generally V-shaped, and the two terminating ends of the V are each bent obliquely at a slight angle of less than 45 degrees. The compound side wall 133 contains a first threaded insert 121 and a second threaded insert 127 . The compound side wall 133 also contains a first tab 129 and a second tab 131 to facilitate hand retention of the triangular shaped rack 100 . The first tab 129 and the second tab 131 may be cut away from the compound side wall 133 and bent perpendicular to the compound side wall, or the first tab 129 and the second tab 131 may be molded, mechanically, or chemically attached to the compound side wall 133 .
The compound side wall 133 makes up two of the three sides of the triangular shaped rack 100 , and the third side of the triangular shaped rack is made up of two partial side walls, a first partial side wall 101 and a second partial side wall 103 . The first partial side wall 101 is bent to form a right angle and contains two slots, a y-axis compression slot 117 and an x-axis compression slot 113 . The purpose of the y-axis compression slot 117 is to allow travel of the first partial side wall 101 and the second partial side wall 103 in the y-axis for compressing a formation of playing balls. The purpose of the x-axis compression slot 113 is to allow travel of the second partial side wall 103 in relation to the first partial side wall 101 in the x-axis for compressing a formation of playing balls in the x-axis. The first partial side wall 101 contains a bevel 115 to provide a smooth and continuous surface between the first partial side wall 101 and the second partial side wall 103 along the interior of the triangular shaped rack 100 . The second partial side wall 103 is also bent to form a right angle, but contains one slot, a y-axis compression slot 119 . The second partial side wall 103 contains two threaded inserts, an x-axis first threaded insert 105 and an x-axis second threaded insert 107 .
The first partial side wall 101 and the second partial side wall 103 are connected using a first screw 109 and a second screw 111 . Washers 141 and 142 are optionally used with said first screw 109 and said second screw 111 . The first screw 109 and the second screw 111 are placed through the first partial side wall x-axis compression slot 113 , and fastened to the second partial side wall using the threaded inserts 105 and 107 . The clearance between the screws 109 and 111 and the threaded inserts 105 and 107 is such that the first partial side wall 101 and the second partial side wall 103 glide smoothly in the x-axis, and the screws 109 and 111 and the washers 141 and 142 travel freely along the length of the first partial side wall x-axis compression slot 113 .
The first partial side wall 101 and the second partial side wall 103 , once connected together, are further connected to the compound side wall 133 . The first partial side wall 101 is connected to the compound side wall 133 by placing a first partial side wall y-axis screw 125 through the first partial side wall y-axis compression slot 117 . The first partial side wall y-axis screw 125 is fastened to the compound side wall 133 using a compound side wall first threaded insert 127 . The first partial side wall y-axis screw 125 may optionally contain a first partial side wall y-axis washer 143 . The clearance between the first partial side wall y-axis screw 125 and the compound side wall second threaded insert 127 is such that the first partial side wall 101 and the compound side wall 133 glide smoothly in the y-axis, and the first partial side wall y-axis screw 125 and the first partial side wall y-axis washer 143 travel freely along the length of the first partial side wall y-axis compression slot 117 .
The second partial side wall 103 is connected in a similar manner to the compound side wall 133 by placing a second partial side wall y-axis screw 123 through a second partial side wall y-axis compression slot 119 , and fastened to the compound side wall 133 using the compound side wall first threaded insert 121 . The second partial side wall y-axis screw 123 may optionally contain a second partial side wall y-axis washer 140 . The clearance between the second partial side wall y-axis screw 123 and the compound side wall first threaded insert 121 is such that the second partial side wall 103 and the compound side wall 133 glide smoothly in the y-axis, and the second partial side wall y-axis screw 123 and the second partial side wall y-axis washer 140 travel freely along the length of the second partial side wall y-axis compression slot 119 .
The first partial side wall 101 and the second partial side wall 103 may optionally contain handles, tabs, grips, or other such structures to assist in retaining the first partial side wall 101 and the second partial side wall 103 with one's fingers.
The compound side wall 133 , the first partial side wall 101 and the second partial side wall 103 are made of a rigid and durable material such as molded graphite, wood, lexan, polypropylene, polystyrene, Acrylonitrile-butadiene-styrene, Polycarbonate, Nylon, Polyethylene-terephthalate, Acetal Resin (such as acetal polyoxymethylene (POM) resin, an example of which is the product manufactured by DUPONT™ under the trade name DELRIN®), Acrylic, metal, fiberglass, or another plastic material.
Referring now to FIG. 2A , an exploded broken-away view of a ball setting and tightening rack according to another embodiment of the present invention is shown. The ball setting and tightening rack of FIG. 2A is similar to the ball setting and tightening rack shown in FIG. 2 , except that the compound side wall 133 , the first partial side wall 101 and the second partial side wall 103 are connected without the use of external hardware. The compound side wall 133 contains a first y-axis flange 201 and a second y-axis flange 206 . The first y-axis flange 201 and the second y-axis flange 206 are integral to the compound side wall 133 . The first y-axis flange 201 is shaped as a circle with two truncated arcs and is oriented such that the second partial side wall y-axis compression slot 119 will fit over the first y-axis flange 201 when properly aligned with said first y-axis flange 201 , and will be securely retained on said first y-axis flange 201 when rotated. The second y-axis flange 206 is also shaped as a circle with two truncated arcs and is oriented such that the first partial side wall y-axis compression slot 117 will fit over the second y-axis flange 206 when properly aligned with said second y-axis flange 206 , and will be securely retained on said second y-axis flange 206 when rotated.
The first partial side wall 101 contains a first handle 205 and the second partial side wall 103 contains a second handle 202 . The first handle 205 and the second handle 202 are used to assist in raising the first partial side wall 101 and the second partial side wall 103 when removing the ball setting and tightening rack from the playing balls.
The first partial side wall 101 and the second partial side wall 103 are connected by placing a first x-axis flange 204 and a second x-axis flange 207 through the key slot first partial side wall x-axis compression slot 203 . The compound side wall 133 is connected to the assembled first partial side wall 101 and second partial side wall 103 by placing the first y-axis flange 201 through the second partial side wall y-axis compression slot 119 and placing the second y-axis flange 206 through the first partial side wall y-axis compression slot 117 .
FIG. 2B is another exploded view of the ball setting and tightening rack shown in FIG. 2A . FIG. 2B clearly shows the first x-axis flange 204 which is shaped as a circle with two truncated arcs, and the second x-axis flange 207 which is shaped as a circle. To join the first partial side wall 101 and the second partial side wall 103 , the first x-axis flange 204 is inserted in the key slot first partial side wall x-axis compression slot 203 at an angle that allows for insertion. The second partial side wall 103 is then rotated to allow the second x-axis flange 207 to be inserted into the rounded end of the key slot first partial side wall x-axis compression slot 203 .
Referring now to FIG. 3 , a ball setting and tightening rack is shown in use. Playing balls 301 are placed within the confines of the ball setting and tightening rack. To tighten the formation of playing balls 301 , the first partial side wall 101 and the second partial side wall 103 are pushed toward the compound side wall 133 . Simultaneously, the first partial side wall 101 and the second partial side wall 103 are pushed toward each other along the x-axis. These two actions will compress the playing balls 301 tightly together. Once the compression action is complete, the first partial side wall 101 and the second partial side wall 103 are rotated upward, and the ball setting and tightening rack is slid forward, away from the formation of playing balls 301 . FIG. 5 illustrates the upward rotation of the first partial side wall 101 and the second partial side wall 103 . The first tab 129 and the second tab 131 can be used to hold the ball setting and tightening rack while compressing the playing ball formation and also while removing the ball setting and tightening rack from the formation of playing balls 301 .
FIG. 4 shows a top plan view of a ball setting and tightening rack according to one embodiment of the present invention.
FIG. 5 is a side elevation view of a ball setting and tightening rack shown in the open position for release of playing balls. Once playing balls are compressed, the first partial side wall 101 and the second partial side wall 103 are rotated upward, and the ball setting and tightening rack is slid forward, away from the formation of playing balls 301 . The direction of rotation is illustrated as 501 .
FIG. 6 is a rear elevation view of a ball setting and tightening rack according to one embodiment of the present invention. The partial side wall x-axis compression slot 113 is shown with the x-axis first screw 109 and the x-axis second screw 111 in position within the partial side wall x-axis compression slot 113 .
Referring now to FIG. 7 , a ball setting and tightening rack according to another embodiment of the present invention is shown. FIG. 7 shows a diamond shaped rack assembly 700 that may be used to accommodate a grouping of 9 playing balls, a grouping that is commonly used in variations of the game of billiards such as 9 ball and snooker. As shown, a first partial side wall 101 and a second partial side wall 103 are connected to a compound side wall 133 using a slideable hinge mechanism that, in one embodiment of the present invention, is comprised of a slot 119 and a fastener 123 . The assembly allows for the compaction of a grouping of playing balls, and subsequent horizontal removal of the assembly by raising the compound side wall 133 as shown by the direction of travel arrow 710 , and sliding the assembly away from the compacted grouping of balls. FIG. 8 shows a plan view of the assembly in use. FIG. 9 shows a side view of the assembly, and FIG. 10 shows an end elevation view of the assembly.
It is, therefore, apparent that there has been provided, in accordance with the various objects of the present invention, an improved apparatus for creating a compact grouping of playing balls. While the various objects of this invention have been described in conjunction with preferred embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. | An improved ball setting and tightening rack for creating a compact formation of playing balls on a playing surface that is used for playing billiards, pool, snooker, or any other game requiring a tight grouping of playing balls on a playing surface. The improved ball setting and tightening rack contains a mechanism for both creating a compact formation of playing balls and for aiding in the removal of the rack from the compacted formation of playing balls without disturbing the compacted balls. The improved ball setting and tightening rack uses horizontal compression to create a compact formation of playing balls, thus reducing wear on the playing surface. The improved ball setting and tightening rack also fits in a standard rack holder or rack slot such as the rack holders or rack slots found in billiard halls. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of mixing containers of fluids, most often at least one liquid. More specifically, the device and method of the invention concern disposable, sealed containers and various devices and processes for mixing the contents therein.
2. Description of the Related Art
The biopharmaceutical process industry has been moving toward technologies that use disposable manufacturing components versus stainless steel tanks and piping. One key component is bioprocessing containers (BPCs). Conventional manufacturing, mixing and/or stirring devices have been used in this type of industry for a considerable period of time. In one type of system, the various ingredients or components are introduced into a typical glass beaker.
When a large scale production is required, the glass beaker may be replaced by a large metal vat or other conventional industrial vessel that also provides heating and cooling capacity. In either system, the components are sequentially or consecutively added to the vessel where the mixing and/or stirring is conducted. In such systems, a stirring device is generally inserted through the upper, open face of the container and powered from an external source. Additionally, reuse of the conventional system requires significant cleaning and sterilization processes to ensure the absence of undesirable materials.
Improvements to the traditional beaker or industrial vat mixing systems include those described in U.S. Pat. No. 5,795,330, No. 5,941,635, No. 6,076,457, and No. 6,190,913, each of which is herein incorporated by reference in its entirety.
SUMMARY OF THE INVENTION
In order to overcome the problems associated with conventional BPC mixing devices, the present invention utilizes a new container-heat exchanger combination. Specifically, the BPC of the invention generally includes a flexible container, placed inside a rigid heat exchanger. In one embodiment, the flexible container is destroyed and replaced after use to eliminate the necessity of cleaning and sterilization. The shape of the heat exchanger is selected to correspond to the shape of the flexible container when the container is filled. Because the container is inserted into a cavity in the heat exchanger, by matching the shape of the heat exchanger (in particular, the cavity) to the shape of the container, the efficiency of the heating and/or cooling elements can be increased.
The BPC of the invention is designed to be utilized with a mixing device. In a first embodiment, a shaft of conventional (optionally disposable) agitator passes through an opening in the container, with the stirring element disposed therein. A motor is provided at the other end of the shaft to rotate the stirring element.
A second embodiment utilizes a magnetic agitator. A magnetic rod is placed inside the container and a magnetic field is generated by a magnetic drive device to rotate the rod. By locating a magnetic drive device external to the container, preferably outside the heat exchanger, the container need not have an opening and may be sealed, albeit with the rod and optional containment disk therein. The magnet rod may be disposed inside a containment disk.
Alternatively, the container and/or heat exchanger may include mixing devices mounted thereto. In a third embodiment, the container has a series of discontinuous baffles, such that when the baffles are alternatively inflated and deflated, the contents of the container can be stirred. Similarly, the container may have a series of fluid-filled sleeves, such that the mixing is performed when the sleeves are squeezed. In a final embodiment, the container includes, on the outside thereof, a series of hinged plates, and the cavity of the heat exchanger includes corresponding mechanical plates. When the mechanical plates in the cavity apply pressure to the hinged plates on the outside of the container, the bag is compressed and the contents thereof mixed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial is cut-away view of a first embodiment of the invention.
FIG. 2 is a partial cut-away view of a second embodiment of the invention.
FIG. 3 a is an exploded view of a rod containment device of the invention.
FIG. 3 b is a side view of a containment disk of the invention.
FIG. 4 is a partial cut-away view of a third embodiment of the invention.
FIG. 5 a is an isometric view of a fourth embodiment of the invention.
FIG. 5 b is an isometric view of a fifth embodiment of the invention.
FIG. 5 c is an isometric view of a sixth embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
A bioprocess container (BPC) in accordance with the invention is shown in the various figures, each figure detailing an embodiment thereof. FIG. 1 shows a BPC 10 , comprising a flexible container 12 in conjunction with a rigid, jacket-type heat exchanger 14 . Specifically, heat exchanger 14 comprises a cavity 15 , defined by a bottom 16 , and side walls 18 . For simplicity, container 12 is shown as being seated in heat exchanger 14 , however, optionally, a small section may extend above side walls 18 heat exchanger 14 . Although container 12 and heat exchanger 14 are shown in the shape of cylinders, any three-dimensional shape may be used. Preferably, however, the shape of cavity 15 of heat exchanger 14 is selected as to correspond to the size and shape of container 12 when filled. When the sizes and shapes correspond, the exterior surfaces of container 12 contact the interior surface of cavity 15 to increase efficiency of heat transfer therebetween. In any event, although the shape of each of container 12 and cavity 15 may be any three dimensional shape, e.g., rectangular prism, cubic, substantially spherical, pyramidal, and conical, a cylindrical shape, having either squared or rounded-off comers, is preferred.
Although the structure and size of container 12 is not particularly limited by the invention, preferably, container 12 is cylindrically shaped (approximately 36″ diameter by 30″ high) and made of polymeric materials, such as polyolefins, thermoplastic elastomers, polyamides, polyesters, polyimides, polysulphones, or barrier polymers (such as MX D 6 available from Mitsubishi Gas Chemical America, Inc. of New York, N.Y.; ethyl vinyl alcohol, polychlorotetrafluoroethylene, polyvinyl chloride). Most preferred however are polyolefins, thermoplastic elastomers and polyamides, alone or in combination. The polymeric materials may be processed in a multilayer laminate and/or film with a thickness from about 2 to about 12 mils, typically about 4 to about 8, and preferably from about 6 to about 8 mils.
Preferably, side walls 18 of heat exchanger 14 contain liquid-transfer media in spirally arranged tubes. Thus, when heating of the contents of container 12 is desired, the liquid-transfer media can be either heated or cooled to add or remove heat from container 12 . During operation, the liquid transfer medium is pumped from an external location (where it is heated or cooled), through the tubes (transferring heat either to or from container 12 ), and back to the external location. In order to cool container 12 , the liquid transfer medium is first cooled before it is pumped into the tubes.
In any event, the liquid-transfer media may be replaced by conventional heating or cooling coils, such as electric resistance or refrigerant-filled coils. Such heating and cooling coils may be provided independently or may both be incorporated into the same heat exchanger 14 . For example, heat exchanger 14 preferably comprises a series of circular heat exchanger plates in side walls 18 , providing a means for transferring heat out of the water by circulating a colder liquid through closed channels on the plate surface.
FIG. 1 also depicts a BPC mixing device comprising BPC 10 . Specifically, the BPC mixing device comprises BPC 10 and an agitator 22 . Agitator 22 , in one embodiment, comprises a shaft 24 , extending through an aperture 25 in a first end 26 of container 12 as to maintain sealing of container 12 . It is considered within the scope of the invention for aperture 25 to be a one-way port, allowing introduction of agitator 22 without allowing exit of the contents of container 12 . One extreme of shaft 24 terminates in a stirring element 28 , inside container 12 . Additionally, a motor 30 is connected to the section of shaft 24 external to container 12 . Alternatively, however, shaft 24 may extend through a second end 32 of container 12 and optionally through bottom 16 of heat exchanger, such that motor 30 is disposed either integral with bottom 16 or below heat exchanger 14 . Although FIG. 1 , shows motor 30 disposed at the extreme opposite end from stirring element, as long as motor 30 is located outside container 12 , any location is sufficient.
It must be noted that as used herein, the terms “stir”, “mix” and “agitate” are considered equivalents and are interchangeable, as each simply means manipulating the contents of container 12 to, for example, to incorporate two substances (such as liquid into liquid or a solid into a liquid), or simply to disturb a single substance. Thus, no distinction should be inferred from the uses of these different terms.
Similarly, while stirring element 28 is depicted as a substantially flat, horizontally aligned device (with respect to the long axis of shaft 24 ), having multiple arms extending from a center, stirring element 28 need not be so limited. For example, stirring element 28 may be in the shape of a paddle extending vertically with respect to the long axis of shaft 24 , or may have extensions extending in all three dimensions from shaft 24 .
FIG. 2 illustrates a second BPC mixing device embodiment in accordance with the invention. Specifically, the agitator in this embodiment comprises a magnetic rod 40 and a magnetic drive mechanism 42 (not shown). Magnetic drive mechanism 42 can be any device capable of generating a rotating magnetic field, such as a second magnetic rod attached to a motor, located either integral with heat exchanger 14 , such as in bottom 16 , or somewhere external thereto. In order to increase the efficiency of stirring created by the rotation of magnetic rod 40 , the surface upon which magnetic rod 40 rotates, e.g., second end 32 , may be provided with a non-stick or non-abrasive, low-friction coating, such as a polyolefinic material, preferably polytetrafluoroethylene. Although rod 40 is described as a magnetic rod, rod 40 may also be a magnetizable material, such as ferrous metals or ferrous metal-containing materials.
For example, in such an embodiment, 485 L of water can be cooled from 70.1° F. to 49.0° F. in 2.0 hours. The cooling liquid supply in the plates of heat exchanger 14 set-point is 38° F. with the closed system supply operating in a range from 38.5-46.9° F. Continuous motion of the contents of the disposable container 12 , formed from a modified polyethylene, is generated by rod 40 , having a tapered shape (e.g., diameter of 25 mm and 90 mm long), rotating at 650 rpm. By recording the water temperature at 8 locations, including 4 depths, 3 radial distances and 4 locating angles, the mixing of the contents of container 12 can be measured. The data shown in Table I indicates that when the invention is employed, even or uniform cooling can be achieved.
TABLE I
Test
Location
Radial
Location
Angle
Distance
Depth
Temp.
No.
(degrees)
(inches)
(inches)
(° F.)
1
0
18
24
60.5
2
90
18
18
60.4
3
180
18
12
60.6
4
180
9
6
60.7
5
180
9
24
60.8
6
180
0
6
61.3
7
180
0
24
61.2
8
270
9
18
61.3
Mean
60.8
Standard Deviation
0.366
In a second example, heat exchanger 14 heats the liquid in container 12 , formed from a modified polyethylene, by circulating a liquid having a temperature hotter than the water in the in container 12 . 446 L of water is heated from 41.9° F. to 77.6° F. in 1.3 hours, with the liquid in heat exchanger 14 having a set point of 95° F., and the closed system operating in a range from 77.1-96.2° F.
FIGS. 3 a and 3 b show a rod containment disk 100 of the invention. Conventional magnetic stirrers often become free from the magnetic field, and as a result, the mixing stops. Thus, the inventors have developed a containment disk, indicated at 100 , into which magnetic rod 40 is placed. Due to the design of containment disk 100 , rod 40 is prevented from exiting the magnetic field. In particular, containment disk 100 preferably has an upper ring 105 and a lower ring 108 , which when assembled with bolts 110 and spacers 115 , form the structure shown in FIG. 3 b . The exploded view in FIG. 3 a shows that bolts 110 pass through holes 112 in upper ring 105 and into threaded recesses 118 of lower ring 108 . The length of bolts 110 and spacers 115 are preferably selected such that when constructed, the distance between upper ring 105 and lower ring 108 is large enough to allow rotation of rod 40 and permit substantially unobstructed fluid flow therein, while simultaneously preventing rod 40 from escaping containment disk 100 . While containment disk 100 is shown in FIGS. 3 a and 3 b as being a separate device, it is preferable to integrate at lower ring 108 onto a plate 120 . Typically plate 120 is adhered to or part of container 12 and serves as the surface upon which rod 40 rotates.
Typically, each of upper plate 105 , lower plate 108 , bolts 110 and spacers 115 are constructed from the same types of materials as container 12 , preferably a polyolefin and more preferably low-density polyethylene. However, it is also considered within the scope of the invention to form any one of the components of containment disk of other materials, such as metal. In order to reduce friction, plate 120 is also preferably at least coated with a reduced-friction coating, such as polytetrafluoroethylene.
Preferably, each of the components of containment disk 100 is injection molded and once assembled, the components are ultrasonically welded together with rod 40 placed inside. Additionally, while upper ring 105 is shown as having a central aperture 125 , in a preferred embodiment, this aperture 125 is not large enough for rod 40 to fit through without disassembling containment disk 100 and is merely present to increase fluid flow about rod 40 .
Because conventional magnetic rods are often tapered at their ends, the space formed between upper ring 105 and lower ring 108 is preferably similarly tapered. Because the particular shape of the tapered surface can correspond to the shape of the particular shape of rod 40 to be enclosed therein, containment disk 100 can effectively allow rod 40 to rotate freely without risking it leaving the magnetic field.
Although it is preferable to position containment disk 100 at the bottom of container 12 with magnetic drive mechanism 42 located below container 12 , it is also considered within the scope of the invention to mount containment disk 100 removed from the bottom of container 12 . This may be accomplished, for example, with one or more feet supporting containment disk 100 , or by attaching the outer circumferences of upper ring 105 and lower ring 108 to the inside wall of container 12 at the desired location. Finally, plate 120 may be eliminated and lower plate 108 be provided with an aperture when containment disk 100 is not positioned at the bottom of container 12 to allow for efficient fluid flow. In order to rotate rod 40 , magnetic drive means 42 may comprise, instead of a rotating magnetic field, a pulsating magnetic field, alternating polarities to drive rod 40 inside containment disk 100 .
Containment disk 100 may also be equipped with a baffle element 110 attached to upper ring 105 ( FIG. 3 b ). Preferably, baffle element 110 is included to hinder or otherwise prevent the contents of container 12 from forming a vortex during agitation. In conventional mixing devices using a magnetic rod, if any air is trapped inside the container, rotation of the magnetic rod causes the liquid to form a vortex, necessarily drawing air into the liquid. By including baffle element 110 , the rotation of the liquid can be disrupted enough to limit any vortex formation, while increasing mixing efficiency. Preferably, baffle element 110 is similar in structure to upper ring 105 , but may alternatively be of any shape or size capable of hindering the vortex-causing forces, for example, a rectangular prism, thin vertically-extending flange or pyramid. Additionally, a second set of spacers 130 maintain a space between baffle element I 10 and upper ring 105 . Although spacers 130 are show as being substantially similar in size to spacers 115 , the particular dimensions of spacers 130 are preferably selected as to position baffle element 110 in the location where the vortex-causing forces are greatest.
In an additional set of embodiments, the contents of container 12 are stirred by physically changing the shape and/or dimensions of container 12 . By applying pressure to a particular area or location of container 12 , the contents are displaced and moved to another location inside container 12 . Thus, a shape manipulating means is utilized to stir the contents of container 12 .
In a third embodiment, depicted in FIG. 4 , container 12 comprises at least one bladder 60 , capable of being filled with a fluid disposed about the periphery of container 12 . In order to selectively inflate and/or deflate bladders 60 , an inflating apparatus 62 (not shown), such as an air or water pump is provided. Specifically, by forming an inflated bladder 60 a , and a deflated bladder 60 b , container 12 can be manipulated to create forces therein to mix the contents. While bladders 60 are preferably formed integral with the structure of container 12 , it is also considered within the scope of the invention to form bladders 60 in side walls 18 of heat exchanger 14 or as a separate inflatable/deflateable element between side walls 18 and container 12 (in which case bladders 60 may be affixed to side walls 18 and/or container 12 in a removable or permanent fashion). Bladders 60 may also be in fluid communication with conduits carrying the liquid-transfer media, such that by simply altering the volume or pressure of the liquid-transfer media, the shape of container 12 can be changed. Additionally, baffles 60 may be a single unit, or alternatively, multiple discontinuous units.
In a third example, liquid syrup was mixed with water in a flexible container and single continuous bladder supported by a rigid outer structure. The flexible container was cylindrically shaped, having a diameter of 8 inches, and a circumferential bladder (4 inches in diameter and 440 cubic inches in volume) located at one end. Both the container and bladder were formed from a plastic film, processed into a multilayer laminate with a thickness between about 2 and about 12 mils. A cylindrical outer structure, having an 11 inch diameter was also provided. One milliliter of liquid syrup was introduced at the bottom of 1.7 gallons of water. After 29 cycles (each cycle including inflating the bladder completely with air and subsequently deflating the bladder) over 2 minutes, approximately 90% of the syrup had become mixed into the water. This mixing percentage can be determined by any sufficient means, for example, by measuring optical color change or opacity of the water.
Furthermore, bladders 60 may be replaced by other devices designed to manipulate the shape of container 12 as to agitate the contents disposed therein. For example, FIG. 5 a shows container 12 , wherein static fluid-filled sleeves 70 are attached to the exterior. Thus, in order to change the shape of container 12 , one or more sleeves 70 are squeezed by, for example, a clam-shell device, indicated at 71 , which may be motorized or actuated manually. In order to perform the agitating, clam-shell devices 71 simply clamp down on sleeves 70 to force the contents of sleeves 70 into the main body of the container. When more than one sleeve 70 is provided, the sleeves 70 may be squeezed simultaneously or independently.
One or more arms 80 may be attached to container 12 , as shown in FIG. 5 b , such that when arms 80 are pushed, container 12 is deformed and fluid is forced from the area in proximity to arms 80 . Preferably, a stationary baffle 81 is provided near arms 80 , such that before entering the main section of container 12 , the fluid must first pass stationary baffle 81 . Additionally, arms 80 may be pulled to deform container 12 by stretching. Preferably, when arms 80 are utilized container 12 resembles a rectangular prism or a cube, with arms 80 positioned at the edges thereof. Most preferably, arms 80 are disposed at the edges, most preferably at each of the corners of container 12 .
Finally, container 12 may be provided with a system comprising at least one hinged plate 90 ( FIG. 5 c ), while heat exchanger 14 includes at least one mechanical plate 95 , corresponding to the location and number of the hinged plates, such that mechanical plates may be activated to create a pulsation in container 12 . Preferably, mechanical plates 95 in heat exchanger 14 correspond in number and position to hinged plates 90 in container 12 , such that each mechanical plate 95 impinges upon a separate hinged plate 90 . Thus, the manipulation of hinged plates 90 functions to massage container 12 to agitate the contents therein.
Although the present invention has been described in terms of specific embodiments, it will be apparent to one skilled in the art that various modifications may be made according to those embodiments without departing from the scope of the applied claims and their equivalents. Accordingly, the present invention should not be construed to be limited to the specific embodiments disclosed herein. | A bioprocess container consists of a flexible container, placed inside a heat exchanger. By providing a disposable agitation device inside the sealed container, a filled container can be stirred without having to open the container. Possible agitation elements include traditional stirrers, rotating magnetic rods, bladder devices integral with the structure of the container, as well as different devices for manipulating the shape of the sealed container. Finally, a containment disk is used to ensure that the magnetic rod is maintained in the magnetic field. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to self-leveling support assemblies for heavy machinery, and in particular to such assemblies used in automatic laundry appliances.
2. Description of the Prior Art
Self-leveling support assemblies for use in redistributing uneven weight loading caused by setting an appliance on an uneven floor, or by vibrations produced in the operation of the appliance, are known in the art. Such assemblies utilize non-expandable tying means to connect two feet which are movable in a general vertical direction.
The assemblies known in the art have the disadvantage of having the feet deployed at all times, thus requiring special packing of the appliance in order to ensure stability of the appliance during shipping. Further, construction of the assemblies known in the art is such that damage to the assembly is likely should the appliance be moved an appreciable distance without such special packing.
SUMMARY OF THE INVENTION
The present invention is an improved self-leveling support assembly having a storage position and a deployed position. The assembly has a rigid horizontal frame member having upwardly diverging slots disposed at opposite ends thereof, covered by brackets having corresponding slots therein. A pin is slidably engaged in each of the pairs of slots, the pin connecting vertically movable feet to respective ends of an adjustable horizontal tension bar.
The adjustable tension bar is comprised of two slidably interlocking portions held together by a spring, each portion having a relieved section therein to receive a flanged end of the other portion, each relieved section having a notched surface arranged to engage the flange received in the relieved section and oppose horizontal movement of the portions with respect to each other. In the deployed position, the feet connected to the tension bar may rest on an uneven surface, and the pins connected to the tension bar will be free to slide in the upwardly diverging slots so as to allow leveling of the appliance and redistribution of the weight thereof.
The assembly is also movable to a retracted or storage position wherein the tension bar is manually extended to a greatest allowable length and pegged in that position by a pin inserted through the tension bar and received in the horizontal frame member. When the bar is in this position, the pins in the diverging slots are forced to the uppermost ends thereof, fully retracting the feet attached thereto, but maintaining the feet in a rigid, vertically disposed position to facilitate easy packing and movement without damage to the assembly, and still providing stability for the appliance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, partly broken away, of a laundry appliance embodying a self-leveling support assembly constructed in accordance with the principles of the present invention.
FIG. 2 is a plan view of a self-leveling support assembly constructed in accordance with the principles of the present invention.
FIG. 3 is a front elevational view of the assembly of FIG. 2.
FIG. 4 is a sectional view taken along line IV--IV of FIG. 3.
FIG. 5 is an elevational view of the assembly of FIG. 2 in a fully-extended deployed position immediately prior to the contact with a supporting surface.
FIG. 6 is an elevational view of the assembly of FIG. 2 in a deployed position on a non-level supporting surface.
FIG. 7 is a partly cut away detailed view of the expandable tension arm of the assembly of FIG. 2.
FIG. 8 is a sectional view taken along line VIII--VIII of FIG. 7.
FIG. 9 is a side elevational view of the appliance of FIG. 1 showing the assembly of FIG. 2 in a deployed position.
FIG. 10 is an exploded view of the self-leveling support assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Domestic appliances such as automatic laundry machines are frequently required to stand on uneven supporting surfaces, such as basement floors or the like. Proper functioning of such machines, in particular vertical axis washing machines having a high speed spin or centrifugal extraction cycle, requires that the machine be level. If the machine is not level the forces generated by the rotating basket and clothes load cause the machine to experience vibrations which are not only noisy, but may also result in structural damage to the machine. In some cases, the vibrations may be sufficient to cause the machine to "walk" over the surface on which it rests.
It is desirable that assemblies constructed to remedy this problem by leveling the appliance be self-leveling so that re-positioning of the appliance by the user will not require readjustment of the leveling assembly by the user. Additionally, storage and packing of the appliance without loss of stability can be achieved if the assembly is retractable to a storage position while still providing support for the appliance.
A laundry appliance of the vertical axis type embodying the principles of the present invention is shown generally at 10 in FIG. 1. The appliance 10 has an outer cabinet 11 which houses a stationary tub 12 therein, containing a perforate spin basket 13. An agitator 14 is vertically disposed inside the spin basket 13, and a generally circular opening 15 in the top of the tub 12 for entry and removal of laundry is covered by a hinged lid 20.
The appliance 10 is driven by a motor and drive means 16 which is supported on an interior frame 17. The frame 17 is supported in tripod fashion by two struts 23 connected at a front of the cabinet 11 to a cabinet base 22. A suspension mechanism 18 minimizes transfer of vibrations from the moving interior parts to the cabinet 11.
As shown in FIG. 9, the front of the cabinet 11 is conventionally supported by threaded screw-adjustable feet 71, for limited selected manual adjustment of the height of the cabinet 11 above a supporting surface 72.
As shown in FIG. 2, a third strut 24 of the tripod supporting the frame 17 is connected to a self-levelling support assembly shown generally at 25. As best seen in FIGS. 2, 3 and 4, the assembly 25 consists of a horizontal frame member 26 made from sheet steel bent to form a vertical flat wall 30 and a horizontal flat wall 60 at a right angle thereto. A stiffening portion 61 of the horizontal wall 60 is bent partially upwardly to add strength to the mid point of the horizontal wall 60. The top of the vertical wall 30 is bent into an L-shaped configuration having a horizontal portion 37 and a vertical portion 36. As shown in FIG. 4, the vertical portion 36 engages a portion 32 of the cabinet 11 and is held in place by three machine screws 33. Outwardly extending ends 37a of the top horizontal portion 37 are bent downwardly to abut end brackets 35, and are attached thereto by any suitable means, such as by spot welding. Supporting brackets 40 are attached to the end brackets 35 such as by spot welding, and are connected to a cabinet frame 34.
As shown in FIGS. 3, 4 and 10, a bracket 41 and a bracket 42 are connected respectively at the left and right ends of the assembly 25. The brackets are attached to the horizontal portion 60 of the frame member by any suitable means, such as by spot welding, and are held in place by an upwardly extending tab 66 which extends through slots in the top horizontal portion 37 of the frame and are held in place by respective ones of screws 33. The top horizontal portion 37 thus interconnected with bracket 41 forms a hollow chamber 65.
Upwardly and outwardly slanting slots 62 and 62a are formed in the frame as shown in FIG. 10. As shown in FIG. 4, this is accomplished by bending a severed portion 63 of the vertical wall 30 outwardly of chamber 65. A corresponding slot 43 is formed by bending a portion 45 of the bracket 41.
As best shown in FIGS. 2 and 3, the other bracket 42 has a slot 44 formed therein by bending a portion 46 of the bracket outwardly, the slot 44 slanting outwardly in a direction opposite to that of the slots 43 and 62 so as to register with slot 62a.
Referring to FIGS. 3, 4 and 5, a pair of feet 50 and 51, having respective vertical legs 70 and 64 attached thereto, extend into the chambers 65 formed between the frame 26 and the brackets 41 and 42. A horizontal arm 54 extends into the area between the left bracket 41 and the frame 26, and is engaged in a slot 70a in the upper portion of the leg 70. The arm 54 is held therein by a horizontal pin 52 passing through the leg 70 and a corresponding hole in the arm 54. An identical assembly holds a second horizontal arm 55 in engagement with the leg 64, and the two are held together behind the right bracket 42 by a pin 53.
As assembled, each of the pins 52 and 53 are free to slide within the confines of the respective slots 43 and 44. The outwardly extending portions 45, 63 and 46 and the other outwardly extending wall not shown on the frame member 26 behind the bracket 42, provide bearing surfaces against which the pins 52 and 53 can move.
As shown in detail in FIGS. 7, 8 and 10, the arm 54 has a flanged end 81 which is received in an aperture 76 in the other arm 55. The arm 55 has a similar flange 82 which is received in a similar aperture 73 in the arm 54. Extension of the assembled arm combination is opposed by a biasing spring 56 connected at its ends to each of the arms 54 and 55, and disposed in overlapping rectangular apertures 71 and 85 in the respective arms 54 and 55.
Each of the arms 54 and 55 has a respective second aperture 74 and 77 therein, connected by respective channels 75 and 78 to the apertures 73 and 76. A generally vertical portion 73a of the aperture 73 is disposed at one end of the channel 75, and a generally vertical portion 76a of the aperture 76 is disposed at an end of the channel 78.
As shown in FIG. 3, the assembly 25 may be placed in a retracted position by applying a downward force to move the arms 54 and 55 out of horizontal alignment, and by applying opposed outwardly directed forces to each of the arms 54 and 55 to extend the combination to a greatest length. This allows the flanges 81 and 82 to respectively move into the channels 78 and 75. When this occurs, the pins 52 and 53 are moved a greatest distance apart to the tops of the respective slots 43 and 44, thereby pulling the feet 50 and 51 into the cabinet 11. Because the spring 56 is now extended, the assembly must be pegged in this position, which is accomplished by means of a pin 57 inserted through an aperture in the vertical wall 30.
When the feet 50 and 51 are in the position shown in FIG. 3, the assembly is suitable for packing and/or movement of the appliance 10 without damage to the retracted feet. The stability of the appliance 10 is not lost, however, because the feet 50 and 51 in addition to dimples 31 extending downwardly from the horizontal wall 60, provide a secure means for supporting the appliance 10, even in the retracted position.
Prior to placing the assembly 25 in the deployed positions shown in FIGS. 5 and 6, the front adjustable feet 91 are adjusted to level the front of the appliance 10 on a supporting surface 72 as best as can be achieved. The rear portion of the appliance 10 is raised so that no weight is being supported by the assembly 25, the pin 57 is removed and the arms 54 and 55 are moved back into horizontal alignment. Referring to FIG. 5, the spring 56 will contract pulling the arms 54 and 55 together while the flange 82 slides through the channel 75 into aperture 73 and the flange 81 slides through the channel 78 into aperture 76. Flange 81 and 82 will continue to be moved by spring 56 in respective apertures 76 and 73 until contact is made with end walls opposite respective vertical portions 76a and 73a. The arm combination is thus now in a rigid, non-expandable form, and the feet 50 and 51 are fully extended with the pins 52 and 53 at the bottom of the respective slots 45 and 44. As weight is brought to bear on the rear of the appliance 10, as shown in FIG. 6, the feet 50 and 51 will engage the supporting surface 72 which may be slanted an angle from the horizontal. Extension of the arms 54 and 55 is now prevented because the flanges 81 and 82 abut a limiting means comprising vertical walls 76a and 73a respectively. Instead of assuming a position 50a level with the foot 51, the foot 50 will rest against the supporting surface 72, so that the pin 52 will not slide as far in the slot 43 as the pin 53 slides in the slot 44. The arm combination 54 and 55 will thus be slightly canted but the cabinet 11 and the appliance 10 will be level.
If the appliance 10 is subsequently moved by a user, the assembly 25 will automatically readjust to a changing angle to that the rear of the appliance 10 will automatically be self-leveled whenever moved.
Although changes and modifications may be suggested by those skilled in the art it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art. | A retractable self-leveling assembly for supporting a laundry appliance such as an automatic washer is connected at a rear base portion of the appliance. The assembly has two spaced apart upwardly and outwardly angled slots therein for slidably receiving pins which connect supporting feet to opposite ends of an adjustable tension bar generally at right angles thereto. In a deployed position, the feet extend below the laundry appliance and the weight of the appliance on the feet and tension bar combination causes the pins to slide in the slots to automatically position the feet to compensate for any unevenness in the surface on which the appliance rests. The tension bar may be manually extended to retract the feet into the appliance cabinet during storage or transport of the appliance. | 3 |
FIELD OF THE INVENTION
The present invention relates to novel compounds useful for controlling undesired plants and for retarding plant growth. More particularly, the present invention relates to certain pyridinyloxypyridazines useful for controlling undesired plants and for retarding plant growth.
PRIOR ART
In U.S. Pat. No. 4. 964,895, substituted 4-(4-nitrophenoxy)pyrazoles have been disclosed as being useful as herbicides.
In U.S. Pat. No. 3,427,146, certain phenoxypyridazines have been disclosed as being useful as herbicides.
5-amino-4-chloro-2-phenylpyridizin-3-(2H)-one is a known pyridazinone herbicide and has the common name chloridazon.
4-Chloro-5-methylamino-2(α,α,α-trifluoro-m-tolyl)prisazine-3-(2H)-one is another known pyridazinone herbicide and has the common name norflurazon.
6-Chloro-3-phenylpyridazin-4-yl-S-octyl thiocarbonate is a known pyridazine herbicide and has the common name pyridate.
There is a continuing need in the art for herbicides which provide a broad spectrum of control of weeds and which may be better tolerated by crops. The present invention provides such kind of improved and useful herbicides.
SUMMARY OF THE INVENTION
The novel compounds of the present invention may be depicted by one of the following structural formulas: ##STR1## wherein: X is CF 3 , OCF 2 H, SCF 2 H, OCH 2 CF 3 , OCH 2 CF 2 CF 2 H or OCH(CH 3 )CF 3 .
The present invention provides novel compounds of the general Formula J depicted above which exhibit desirable herbicidal properties and further provides herbicidal compositions for the selective controlling of weeds in crop plants. The compositions comprise one or more compounds of Formula J herein by themselves or admixed with one or more carriers, such as solid and/or liquid inert extenders or diluents and/or wetting agents and optionally other active herbicides, insecticides, fungicides, safeners, growth regulators, plant nutrients and like additaments. The invention also provides an effective method of controlling undesirable plants, such as grasses, perennial and annual broadleafed weeds and so on which comprises applying to the locus of the plants to be controlled an effective amount of at least one pyridinyloxypyridazine to exert a herbicidal action.
These novel pyridinyloxypyridazine compounds which may be employed as an active ingredient in this invention can be prepared by a variety of new and useful processes, such as one of the general procedures as will be described below. Many of the depicted intermediate compounds are novel and useful for preparing the herbicidal pyridinyloxypyridazines herein.
DETAILED DESCRIPTION OF THE INVENTION
It has been shown that the pyridine oxygen-linked pyridazine compounds within the above depicted general Formula J are not only herbicidal against undesirable plants but also have good herbicidal tolerance by certain crop plants, especially corn. Novel compounds herein in many instances provide substantially equal or better herbicidal performance than the present widely commercially employed acetanilides but with better environmental acceptability. The preferred compounds herein provide a broader spectrum of weed control and show good perennial broadleaf activity. The field soil half-life of the preferred compounds provides longer residual control than alachlor but is short enough that any carryover problems are agronomically acceptable.
In this specification and claims, numerical values are not critical unless otherwise stated. That is, the numerical values may be read as if prefaced with the word "about" or "substantially".
The following defines the various terms used in the application.
The term "C 1 -C 10 alkyl" or in the shortened form "C 1 -C 10 alk" as used herein include the straight and branched aliphatic groups of one to ten carbon atoms, such as methyl, ethyl, propyl, isopropyl (1-methylethyl), butyl, isobutyl, (2-methylpropyl), sec-butyl, (1-methylpropyl), tert-butyl, (1,1-dimethylethyl), pentyl, isopentyl, (3-methylbutyl), sec-pentyl (1-methylbutyl), 1,1-dimethylpropyl, 1-2-dimethylpropyl, neopentyl, (2,2-dimethylpropyl), hexyl, isohexyl (4-methylpentyl), sec-hexyl, (1-methylpentyl), 2-methylpentyl, 3-methylpentyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 1,2,2-trimethylpropyl, 1,1,2-trimethylpropyl, and the like. The terms, such as "C 1 -C 3 " and "C 1 -C 5 " are included in the term C 1 -C 10 but with a corresponding lesser number of carbon atoms as indicated.
The term "C 1 -C 3 haloalkyl" as used herein includes such radicals as trifluoromethyl, trichloromethyl, difluoromethyl, chlorodifluoromethyl, fluoromethyl, bromomethyl, pentafluoroethyl, heptafluoro-npropyl, pentachloroethyl, iodo-methyl, etc., where the number of carbon atoms in the alkyl is 1-3, inclusive.
The term "halogen" either alone or in compound words such as "haloalky" denotes fluorine, chlorine, bromine or iodine.
The term "alkoxy" denotes methoxy, ethoxy, n-propyloxy, isopropyloxy and the different butoxy, pentoxy, hexoxy isomers, etc.
The term "alkenyl" denotes straight or branched alkenes, e.g., vinyl, 1-propenyl, 2-propenyl, and the different butenyl, pentenyl, hexenyl isomers, etc.
The term "alkynyl" denotes straight chain or branched alkynes, e.g., ethynyl, 1-propynyl, 2-propynyl, etc., including the different butynyl, pentynyl and hexynyl isomers.
The term "alkylthio" denotes methylthio, ethylthio and the various propylthio, butylthio, pentylthio and hexyithio isomers.
Alkylsulfinyl, alkylsulfonyl, alkylamine, etc., are defined analogously to the above terms.
A process for preparing the compounds of the present invention can be described in the following schematic diagrams which follow below.
The compounds according to this invention are suitably prepared by a variety of processes as will also be described below with greater particularity.
In broad aspect, the preferred overall process for preparing the compounds of Formula J is best viewed in the separate process steps required to prepare the necessary intermediates, immediate precursors and end products of the above formula. The products of "Processes I and II", provide the intermediates necessary for "Process III". The compounds according to Formula J are prepared by either a single process "III" or any combination of "Processes I-III". It is expressly understood that various modifications obvious to those skilled in the art are contemplated. Specific embodiments of the preparation of the compounds herein are described in Examples 1-3 below.
In the sequence of process steps described below, the various symbols defining radical substituents, e.g., X, Y, m, n, R 1 -R 2 , Rf, etc., have the same meaning as defined for the compounds of Formula J, unless otherwise qualified or limited.
Process I
This process describes the preparation of important intermediate compounds of Formula C which are useful in the overall process scheme for producing compounds of Formula J.
The first step in the process for the preparation of compounds of Formula J proceeds from either 2-halo-6-trifluoromethylpyridine or 2-halo-4-trifluoromethylpyridine A, which are commercially available. Treatment of Compound A with an appropriate salt of t-butyl alcohol chosen from potassium, sodium, or lithium gives a compound of Formula B. The reaction can be carried out in any non-reactive organic solvent, such as ether, tetrahydrofuran, benzene or t-butyl alcohol. The reaction temperatures may range from -78° C. to 150° C., preferably 0° C. to 100° C. The reaction period may be chosen from a few minutes to several weeks depending on the amounts of reagents, reaction temperature, etc. After the reaction is complete, the mixture containing the compounds of Formula B is diluted with water and extracted with an organic solvent. The organic solvent is then dried and evaporated in-vacuo.
The compounds of Formula B are utilized as is or if necessary the product is purified by standard methods such as crystallization or column chromatography. ##STR2## The second step in Process I involves the conversion of compounds of Formula B to C by treatment of B with an organic acid chosen from sulfonic acid, p-toluenesulfonic acid, acetic acid, or trifluoroacetic acid. The reaction may be carried out utilizing the organic acid as the solvent or in an organic solvent such as benzene, toluene, ether, methylene chloride, carbon tetrachloride or chloroform. The reaction temperature may range from -78° C. to 150° C., preferably 0° C. to 50° C.
Process II
This process describes the preparation of important intermediate compounds of Formula G which are useful in the overall process scheme for producing compounds of Formula J.
The first step in Process II involves the conversion of 4-benzyloxy-2-pyridone D which is known in the art (R. L. Shone, et al., J. Heterocyclic Chem., 12, 389 (1975)) to compounds of Formula E. Compounds of Formula D are combined together with an appropriate base chosen from sodium hydroxide, potassium hydroxide or lithium hydroxide in water. An appropriate organic solvent is then added to this mixture chosen from carbon tetrachloride, benzene, dioxane or tetrahydrofuran. This two phase mixture is stirred vigorously while an excess of a halogenated methane chosen from CF 2 ClH, CF 2 BrH or CF 2 IH is added slowly to this mixture to give compounds of Formula E. The mixture containing the compounds of Formula E are then diluted with an organic solvent and extracted several times with water. The compounds of Formula E are isolated by removal of the organic solvent in-vacuo and may be used as is or if necessary may be purified by standard methods such as crystallization or column chromatography. ##STR3##
The second step in Process II involves the conversion of compounds of Formula E to G by treatment of E with hydrogen gas at a pressure from atmospheric to 0 kilo Pascals (kPa) and a catalyst chosen from Pd--C, Pt--C, or PtO 2 in an appropriate solvent chosen from benzene, methanol, ethanol or tetrahydrofuran.
An alternative method for preparing compounds of Formula G involves the conversion of compounds of Formula D to compounds of Formula F by treatment with a chlorinating agent chosen from SOCl 2 , SO 2 Cl 2 , POCl 3 , (CO) 2 Cl 2 or PCl 5 either neat or in an appropriate organic solvent chosen from benzene, carbon tetrachloride, methylene chloride or chloroform. The compounds of Formula F are then treated with an appropriate fluorinated primary, secondary, or tertiary alcohol and a base chosen from NaH, lithium diisopropylamide or KH in an appropriate organic solvent chosen from dimethylsulfoxide, N,N-dimethylformamide, tetrahydrofuran or ether to give an intermediate compound 2-fluoroalkoxy-4-benzyloxypyridine, F'. The reaction temperature may range from -78° C. to 150° C. preferably 20° C. to 100° C. The reaction period may be chosen from a few minutes to several weeks depending on the amounts of reagents, reaction temperature, etc. The compounds of Formula F' are isolated by evaporation of the solvent followed by partitioning the crude product between an organic solvent and water. The organic solvent is then dried and evaporated in-vacuo. The compounds of Formula F' may be used as is or purified by standard methods such as crystallization or column chromatography. The compounds of Formula F' are then converted to compounds of Formula G by hydrogenation in a manner that is identical to that described above form the conversion of compounds of Formula E to compounds of Formula G.
Process III
This process describes the preparation of compounds of Formula J. Pyridinols of Formula H and pyridazines of Formula I, which are described in M. S. South, et. al., U.S. Patent application pending, are combined together with an appropriate base chosen from sodium hydride, potassium hydride, sodium bicarbonate, potassium carbonate, triethyl amine, N,N-diisopyropylethylamine, 2,6-lutidine, or DBU and optionally an appropriate catalyst chosen from TiCl 4 , SnCl 2 , FeCl 3 CuCl, CuBr, AgBF 4 or CuF to give compounds of Formula J. ##STR4## In these cases X m and Y n are defined as given above for Formula J. The reaction may be carried out in any anhydrous solvent or mixture of solvents, preferably ether, tetrahydrofuran, N,N-dimethylformamide, dimethylsulfoxide, diglyme, glyme, sulfolane, benzene, toluene or xylene. The reaction temperatures may range from -78° C. to 180° C., preferably 0° C. to 150°C. The reaction period may be chosen from a few minutes to several weeks depending on the amounts of reagents, reaction temperature, etc. The products of Formula J are isolated by diluting the reaction mixture with an organic solvent and extracting with water. The organic solvent is then removed in-vacuo and the products of Formula J are either used as is or purified by standard methods such as crystallization or chromatography, etc.
Preparation of some of the intermediates of the compounds of this invention and the compounds of this invention are illustrated by the following examples. In the examples which follow, all percentages are given on a weight basis unless otherwise indicated.
EXAMPLE 1
This example describes the preparation of 5-methoxy-3-[[6-(trifluoromethyl)-2-pyridinyl]oxy]pyridazine, Compound No. 2, and is a specific embodiment of Process I and Process III.
A. 2-Chloro-6-trifluoromethylpyridine (5.0 g, 27.6 mmol) was dissolved in tert-butyl alcohol (135 mL). Potassium tert-butoxide (25.0 g, 220 mmol) was added and the mixture was refluxed under nitrogen for 20 h. After cooling, cold 3N HCl was carefully added to the flask until the pH was approximately 1-2. The resulting solution was extracted several times with methylene chloride. The organic layers were dried (MgSO 4 ) and evaporated. This residue was then treated with trifluoroacetic acid 1.5 mL) at 80° C. for 2 h. The solution was neutralized with aqueous sodium bicarbonate and extracted several times with methylene chloride. The organic layer was dried (MgSO 4 ), filtered and evaporated in-vacuo. The residue was recrystallized from methylene chloride and hexane to give 6-trifluoromethyl-2-pyridinol (2.8 g, 62% yield) as a white solid, mp=117° C. -118 ° C. Anal. Calcd. for C 6 H 4 NOF 3 : C, 44.19; H, 2.47; N, 8.59
Found: C, 44.27; H, 2.43; N, 8.56
B. 6-Trifluoromethyl-2-pyridinol (2.0 g, 12.27 mmol), 2,6-lutidine (2.3 g, 21.5 mol) and 3-chloro-5-methoxypyridazine (1.77 g, 12.27 mmol) were added to xylenes (30 Ml). The solution was refluxed under nitrogen for 17 h. After cooling, the solution was added to water and extracted three times with methylene chloride. The organic layer was dried (MgSO 4 ), filtered and evaporated in-vacuo. The crude product was purified by HPLC (1:1 ethyl acetate/methylene chloride) to give 5-methoxy-3-[6-(trifluoromethyl)-2-pyridinyl]oxy]pyridazine (1.5 g, 45% yield, Compound No. 2) as a light yellow oil, nD=1.5181.
EXAMPLE 2
This example describes the preparation of 3-[[2-(difluoromethoxy)-4pyridinyl]oxy]-5-methoxypyridazine, Example No. 5, and is a specific embodiment of Processes II and III.
A. 4-Benzyloxy-2-pyridone (311.4 g, 1.55 mol) was mechanically stirred under nitrogen in a mixture of dioxane (6.2 L) and 50% sodium hydroxide (2.48 L) while chlorodifluoromethane (1,332.4 g, 15.5 mol) was condensed into the 22 L flask over a 4 h period using a dry-ice condenser that was attached to one of the necks of the 4-neck flask. The temperature inside the flask was maintained below 35° C. by means of an ice-bath. The mixture was then stirred for 18 h maintaining the temperature of the mixture between 25° C. and 35° C. The dry-ice condenser was in place during the 18 h reaction time. The mixture was then diluted with water, acidified to pH 1 with conc. HCl and extracted three times with ethyl acetate. If emulsions formed the whole mixture was filtered through a bed of celite. The combined organic layers were dried (MgSO 4 ), filtered through silica gel and concentrated in-vacuo. The crude oil was chromatographed on a Prep-500 HPLC to give 2-difluoromethoxy-4-benzyloxypyridine (219.75 g, 56% yield) as a yellow oil, nD =1.5274. Anal. Calcd. for C 13 H 11 NO 2 F 2 : C,62.15; H,4.41; N,5.58 Found: C,62.18; H,4.40; N,5.52.
B. 2-Difluoromethoxy-4-benzyloxypyridine (219.75 g, 0.875 mol), ethanol (500 mL) and palladium on carbon (7.8 g, 5 mol %, 50% by weight water) were shaken on a Parr hydrogenator at 5393 kPa of hydrogen at RT for 2.5 h. The mixture was then filtered through celite and the solvent was evaporated in-vacuo. 2-Difluoromethoxy-4-hydroxypyridine (123 g, 87% yield) was obtained as a white solid after trituration with hexane, mp=88.6° C. -89.8° C. Anal. Calcd. for C 6 H 5 NO 2 F 2 : C,44.73; H,3.13; N,8.69 Found: C,44.82; H,3.13; N,8.76.
C. 2-Difluoromethoxy-4-hydroxypyridine (123 g, 0.764 mol), 3-chloro-5-methoxypyridazine (110.47 g, 0.764 mol), potassium carbonate (211.18 g, 1.53 mol), CuBr (54.80 g, 0.382 mol) and 18-crown-6 (1 g) were mechanically stirred under nitrogen in diglyme (1.28 L) at 100° C. for 30 h. The mixture was cooled to RT and partitioned between ethyl acetate and 2 L of 3% HCl. The layers were separated. The aqueous layer was then adjusted to pH--1 with conc. HCl and extracted twice with additional ethyl acetate. The combined organics were filtered through silica gel and then extracted twice with 1.5 N NaOH. Solids were formed which were removed by filtering the organic layer through silica gel and celite. The organic layer was dried (MgSO 4 ), filtered through silica gel and evaporated in-vacuo. The residue was triturated with ethyl acetate and filtered to give pure 3-[[2-(difluoromethoxy)-4-pyridinyl]oxy]-5-methoxypyridazine (92.5 g, 45% yield) as a light brown solid, mp=119° C. -120.5° C.
EXAMPLE 3
This example describes the preparation of 5-methoxy-3-[[2-(2,2,2-trifluoro-1-methylethoxy)-4pyridinyl]oxy]pyridazine, Compound No. 10 and is a specific embodiment of Processes II and III.
A. 4-Benzyloxy-2-pyridone (26.3 g, 0.131 mol) and POCl 3 (200 mL) was heated at reflux for 2 h. The mixture was cooled and poured into 1 L of crushed ice and then 500 mL of ethyl acetate was added. The mixture was treated with decolorizing carbon, filtered and then treated with solid potassium carbonate until gas ceased to evolve. The mixture was filtered and the layers were separated. The aqueous layer was extracted three times with ethyl acetate. The combined organic layers were treated with decolorizing carbon, dried (MgSO 4 ), filtered and the solvent was removed in-vacuo. The crude product was chromatographed to give 2-chloro-4-benzyloxypyridine (8 g, 28% yield) as a white solid, mp=91° C. -93° C. Anal. Calcd. for C 12 H 10 NO: C,65.61; H,4.59; N,6.38 Found: C,,65.59; H,4.55; N,6.39.
B. 2-Chloro-4-benzyloxypyridine (1.5 g, 6.85 mmol), 1,1,1-trifluoroisopropan-2-ol (1.56 g, 13.7 mmol) and NaH (0.33 g of 95%, 13.7 mmol) were stirred under nitrogen in DMF (30 mL) at 80° C. for 70 h. After 40 h additional portions (13.7 mmol each) of the alcohol and the NaH were added. The mixture was cooled to RT, poured into water and extracted several times with ethyl acetate. The organic layer was dried (MgSO 4 ), filtered and evaporated in-vacuo. The crude oil was chromatographed to give 4-(phenylmethoxy)-2-(2,2,2-trifluoro-1-methoxyethoxy)-pyridine (1.4 g, 69% yield) as a clear oil. Anal. Calcd. for C 15 H 4 NO 2 F 3 : C,60.61; H,4.75; N,4.71 Found: C,60.70; H,4.82; N,4.71.
C. 4-(Phenylmethoxy)-2-(2,2,2-trifluoro-1-methyloxy)-pyridine (1.19 g, 4 mmol) and palladium on carbon (5 mol %, 50% by weight water) in methanol (50 mL) were shaken on a Parr hydrogenator at 55 psi of hydrogen for 20 min. The mixture was filtered through celite and the solvent was evaporated in-vacuo. The crude material was purified by flash chromatography to give 2-(2,2,2-trifluoro-1-methylethoxy)-4-pyridinol (0.76 g, 92% yield) as a white solid, mp=67° C. -69° C. Anal. Calcd. for C 8 H 8 NO 2 F 3 : C,46.39; H,3.89; N,6.79 Found: C,46.37; H,3.89; N,6.68.
D. 2-(2,2,2-Trifluoro-1-methylethoxy)-4-pyridinol (0.64 g, 3.09 mmol), 3-chloro-5-methoxy-pyridazine (0.44 g, 3.09 mmol), potassium carbonate (0.85 g, 6.18 mmol) and CuBr (0.89 g, 6.18 mmol) were stirred under nitrogen in diglyme (5 mL) at 100° C. for 6 days. The mixture was then poured in water and extracted several times with ethyl acetate. The combined organic layers were dried (MgSO 4 ), filtered and evaporated in-vacuo. The crude product was purified by flash chromatography to give 5-methoxy-3-[[2-(2,2,2-trifluoro-1-methylethoxy)-4-pyridinyl]oxy]pyridazine (0.42 g, 43% yield, Compound No. 10) as a white solid, mp=100° C. -102° C.
Several other compounds of the present invention were prepared using generally the procedures illustrated above or other procedure obvious to one skilled in the art. Specific compounds illustrated of the present invention are given below where the prepared compounds are structurally depicted and named. Melting points and elemental analyses are provided for these compounds in the following table.
__________________________________________________________________________ Analysis (%)CP NO.Name Structure Calc'd__________________________________________________________________________ Found1 PYRIDAZINE, 5-METHOXY-3-[[2-(TRIFLUOROMETHYL)-4- PYRIDINYL]OXY]- MP:52.5-54.0 ##STR5## C 48.72 48.59 H 2.97 2.92 N 15.49 15.462 PYRIDAZINE, 5-METHOXY-3-[[6-(TRIFLUOROMETHYL)-2- PYRIDINYL]OXY]- ##STR6## C 48.72 48.59 H 2.97 2.99 N 15.49 15.413 PYRIDAZINE, 5-METHOXY-3-[[5-(TRIFLUOROMETHYL)-3- PYRIDINYL]OXY]- ##STR7##4 PYRIDAZINE, 5-METHOXY-3-[[4-(TRIFLUOROMETHYL)-2- PYRIDINYL]OXY]- ##STR8## C 47.95 47.93 H 3.29 3.115 PYRIDAZINE, 3-[[2-(DIFLUOROMETHOXY)-4-PYRIDINYL]OXY]-5- METHOXY- MP:119.0-120.5 ##STR9##6 PYRIDAZINE, 3-[[6-(DIFLUOROMETHOXY)-2-PYRIDINYL]OXY]- 5-METHOXY- ##STR10## C 49.08 49.34 H 3.37 3.45 N 15.61 15.397 PYRIDAZINE, 3-[[2-((DIFLUOROMETHYL)THIO]-4-PYRI- DINYL]OXY]-5-METHOXY- MP: 96.0-97.0 ##STR11## C 46.31 46.32 H 3.18 3.17 N 14.73 14.718 PYRIDAZINE, 5-METHOXY-3-[[2-(2,2,2-TRIFLUOROETHOXY)-4- PYRIDINYL]OXY]- MP: 75.0-76.0 ##STR12## C 47.85 47.79 H 3.35 3.35 N 13.95 13.999 PYRIDAZINE, 5-METHOXY-3[[2-(2,2,3,3-TETRAFLUOROPROPOXY)- 4-PYRIDINYL]OXY]- MP: 48.0-50.0 ##STR13## C 46.86 47.01 H 3.33 3.42 N 12.61 12.5310 PYRIDAZINE, 5-METHOXY-3-[[2-(2,2,2-TRIFLUORO-1-METHYLETH- OXY)-4-PYRIDINYL]OXY]- MP: 100.0-102.0 ##STR14## C 49.53 49.55 H 3.84 3.83 N 13.33 13.30__________________________________________________________________________
PRE-EMERGENT ACTIVITY ON PLANTS
As noted above, compounds of this invention have been found to be effective as herbicides, particularly as pre-emergent herbicides. Tables A and B summarize results of tests conducted to determine the pre-emergent herbicidal activity of the compounds of this invention. The herbicidal ratings used in Tables A and B were assigned according to a scale based on the percent inhibition of each plant species. The symbol C represents complete control and N or a hyphen represents no data.
One set of pre-emergent tests was conducted as follows:
Topsoil was placed in a pan and compacted to a depth of 0.95 to 1.27 cm. from the top of the pan. A predetermined number of seeds of each of several monocotyledonous and dicotyledonous annual plant species and/or vegetative propagules of various perennial plant species were placed on top of the soil. The soil required to level fill a pan after seeding or adding vegetative propagules was weighed into another pan. A known amount of the test compound dissolved or suspended in an organic solvent or water and applied in acetone or water as a carrier was thoroughly mixed with this cover soil, and the herbicide/soil mixture was used as a cover layer for the previously prepared pan. In Table A below the amounts of active ingredient were all equivalent to an application rate of 11.2 kilograms/hectare (kg/ha) or other rate as indicated in Table A. After treatment, the pans were moved to a greenhouse bench where they were watered as needed to give adequate moisture for germination and growth.
Approximately 10-14 days (usually 11 days) after planting and treating, the plants were observed and the results recorded.
The plant species usually regarded as weeds which were utilized in one set of pre-emergent activity tests, the data for which are shown in Table A, are identified by letter headings printed above the columns according to the following legend:
COBU-Cocklebur
VELE-Velvetleaf
DOBR-Downy Brome
MOGL-Morningglory
BYGR-Barnyardgrass
ANBG-Annual Bluegrass
SEJG-Seedling Johnsongrass *
YENS-Yellow Nutsedge
INMU-Indian Mustard
WIBW-Wild Buckwheat
COTT-Cotton
RICE-Rice
SOYB-Soybean
CORN-Corn
WHEA-Wheat
JGRZ-Johnsongrass, Rhizome
CNTH-Canadian Thistle
QGRZ-Quackgrass, Rhizome
FOXT-Foxtail, Green
CWBS-Catchweed Bedstream
RAPE-Rape
CHWD-Chickweed, Common
WDOA-Wild Oats
BLGR-Blackgrass
RUTH-Russian Thistle
FDBW-Field Bindweed
CBGR-Crabgrass, Large
BISW-Birdseye Speedwell
BARL-Barley
TABLE A__________________________________________________________________________CP RateNO. Kg/Ha COTT RICE SOYB CORN WHEA JBRZ YENS CNTH FDBW QGRZ__________________________________________________________________________1 5.6 100 99 99 100 100 98 98 99 100 981 1.1 100 50 98 100 100 40 90 98 100 981 0.28 30 15 95 97 20 5 70 95 99 951 0.07 5 5 40 0 5 0 10 40 99 5__________________________________________________________________________CP RateNO. Kg/Ha FOXT CWBG RAPE WHEA WDOA DOBR BLGR WIBW RUTH CHWD BISW CWBG__________________________________________________________________________1 0.07 90 90 90 0 10 0 15 40 15 95 -- --1 0.004 10 30 25 0 0 0 0 40 0 80 -- --2 0.07 20 0 20 0 0 0 30 -- -- -- -- --2 0.017 0 0 0 0 0 0 0 0 0 0 0 05 75 35 35 75 75 35 99 -- --5 0.017 25 75 30 0 20 30 20 30 0 85 -- --5 0.004 20 30 0 0 0 0 5 15 0 75 -- --5 0.28 100 -- 65 25 35 30 100 -- -- 100 100 1005 0.14 100 -- 75 15 35 35 98 -- -- 100 100 95__________________________________________________________________________CP RateNO. Kg/Ha YENS ANBG SEJG DOBR BYGL MOGL COBW VELE INMU WIBW__________________________________________________________________________1 1.12 100 100 100 100 100 100 90 100 100 1002 1.12 20 70 50 30 80 70 20 70 100 803 1.12 0 30 20 20 50 70 0 40 80 304 2.24 0 10 0 0 0 0 0 0 20 205 11.2 80 100 90 100 100 80 70 100 90 90__________________________________________________________________________CP RateNO. Kg/Ha CBGR SEJG RICE SOYA CORN BYGR COTT VELE MOGL COBW__________________________________________________________________________2 1.12 95 90 30 25 0 70 0 30 75 102 0.28 90 10 0 5 0 50 0 20 35 0__________________________________________________________________________CP RateNO. Kg/Ha FOXT YENS BYGR RICE CORN VELE MOGL COBW SOYB__________________________________________________________________________6 1.0 100 0 0 5 0 100 70 0 200.2 0 0 0 10 0 15 0 0 10__________________________________________________________________________CP RateNO. Kg/Ha RAPE WHEA WIBW BARL CHWD DOBR CWBS BYGR FOXT WDOA__________________________________________________________________________7 1.12 100 30 99 40 -- 85 98 99 100 1008 1.12 100 20 98 25 -- 75 100 99 104 459 1.12 100 98 99 90 100 100 100 99 100 --10 1.12 100 95 99 90 -- 100 99 100 100 85__________________________________________________________________________
POST-EMERGENT HERBICIDE ACTIVITY ON PLANTS
Although, as has been stated above, the compounds of this invention exhibit predominantly preemergence activity in greenhouse testing, nevertheless many of these compounds are active post-emergent herbicides. The post-emergent activity is best seen on younger plants treated at the 11/2 to 2 leaf stage. In the tests which follow, larger and more developed plants were used.
The post-emergence herbicidal activity of compounds of this invention was demonstrated by greenhouse testing, and the results are shown in the following Table B.
Top soil was placed in pans having holes in the bottom and compacted to a depth of 0.95 to 1.27 cm from the top of the pan. A predetermined number of seeds of each of several dicotyledonous and monocotyledonous annual plant species and/or vegetative propagules for the perennial plant species were placed on the soil and pressed into the soil surface. The seeds and/or vegetative propagules were covered with soil and leveled. The pans were then placed on a bench in the greenhouse and watered as needed for germination and growth. After the plants reached the desired age (two to three weeks), each pan (except the control pans) was moved to a spraying chamber and sprayed by means of an atomizer. The spray solution or suspension contained about 0.4% by volume of an emulsifying agent and a sufficient amount of the candidate chemical to give an application rate of the active ingredient of 11.2 kg/ha or other rate as indicated in Table B while applying a total amount of solution or suspension equivalent to 1870 L/ha. The pans were returned to the greenhouse and watered as before and the injury to the plants as compared to those in control pans was observed at approximately 10-14 days (usually 11 days). The plant identifying codes and symbols in Table A are the same as above defined.
TABLE B__________________________________________________________________________CP RateNO. Kg/Ha YENS ANBG SEJG DOBR BYGR MOGL COBU VELE INMU WIBW__________________________________________________________________________1 1.12 30 60 60 30 50 70 60 80 70 902 1.12 0 0 0 0 30 20 20 40 50 403 1.12 0 0 0 0 0 20 20 20 20 04 2.24 0 0 0 40 0 20 0 20 10 05 11.1 50 80 60 40 70 70 50 60 80 90__________________________________________________________________________CP RATENO. Kg/Ha FOXT YENS BNGR RICE CORN VELE MOGL COBU SOYB__________________________________________________________________________6 1.0 0 0 0 0 5 55 45 25 25__________________________________________________________________________CP RATENO. Kg/Ha RAPE WHEA WIBW BARL CHWD DOBR CWBS BLGR FOXT WDOA__________________________________________________________________________9 1.12 99 20 99 30 95 60 95 95 95 8010 0.28 99 15 15 15 35 90 90 95 70 45__________________________________________________________________________
As can be seen from the data above, some of the compounds are suitably safe on certain crops and can thus be used for selective control of weeds in these crops. Known safeners can be added to the formulated herbicidal formulation when additional crop safening is indicated.
The methods of making such compositions are well known. Solutions are prepared by simply mixing the ingredients to be included therein. Fine solid compositions are made by blending and, usually, grinding as in a hammer or fluid energy mill. Suspensions are prepared by wet milling, for example. Granules and pellets can be made by spraying the material containing the active material upon preformed granular carriers or by agglomeration techniques or the like.
The herbicidal compositions of this invention, including concentrates which require dilution prior to application, may contain at least one active ingredient and an adjuvant in liquid or solid form. The compositions are prepared by admixing the active ingredient with an adjuvant including diluents, extenders, carriers, and conditioning agents to provide compositions in the form of finely-divided particulate solids, granules, pellets, solutions, dispersions or emulsions. Thus, it is believed that the active ingredient could be used with an adjuvant such as a finely-divided solid, a liquid of organic origin, water, a wetting agent, a dispersing agent, an emulsifying agent or any suitable combination of these.
Suitable wetting agents include alkyl benzene and alkyl naphthalene sulfonates, sulfated fatty alcohols, amines or acid amides, long chain acid esters of sodium isothionate, esters of sodium sulfosuccinate, sulfated or sulfonated fatty acid esters, petroleum sulfonates, sulfonated vegetable oils, ditertiary acetylenic glycols, polyoxyethylene derivatives of alkylphenols (particularly isooctylphenol and nonylphenyl) and polyoxyethylene derivatives of the mono-higher fatty acid esters of hexitol anhydrides (e.g., sorbitan). Preferred dispersants are methyl cellulose, polyvinyl alcohol, sodium lignin sulfonates, polymeric alkyl naphthalene sulfonates, sodium naphthalene sulfonate and polymethylene bisnaphthalene sulfonate.
Wettable powders are water-dispersible compositions containing one or more active ingredients, an inert solid extender and one or more wetting and dispersing agents. The inert solid extenders are usually of mineral origin such as the natural clays, diatomaceous earth and synthetic minerals derived from silica and the like. Examples of such extenders include kaolinites, attapulgite clay and synthetic magnesium silicate. The wettable powders compositions of this invention usually contain from about 0.5 to 60 parts (preferably from 5-20 parts) of active ingredient, from about 0.25 to 25 parts (preferably 1-15 parts) of wetting agent, from about 0.25 to 25 parts (preferably 1.0-15 parts) of dispersant and from 5 to about 95 parts (preferably 5-50 paints) of inert solid extender, all parts being by weight of the total composition. Where required, from about 0.1 to 2.0 parts of the solid inert extender can be replaced by a corrosion inhibitor or anti-foaming agent or both.
Other formulations include dust concentrates comprising from 0.1 to 60% by weight of the active ingredient on a suitable extender; these dusts may be diluted for application at concentrations within the range of from about 0.1-10% by weight.
Aqueous suspensions or emulsions may be prepared by stirring a nonaqueous solution of a water-insoluble active ingredient and an emulsification agent with water until uniform and then homogenizing to give stable emulsions of very finely-divided particles. The resulting concentrated aqueous suspension is characterized by its extremely small particle size, so that when diluted and sprayed, coverage is very uniform. Suitable concentrations of these formulations contain from about 0.1-60% preferably 5-50% by weight of active ingredient, the upper limit being determined by the solubility limit of active ingredient in the solvent.
Concentrates are usually solutions of active ingredient in water-immiscible or partially water-immiscible solvents together with a surface active agent. Suitable solvents for the active ingredient of this invention include N,N-dimethylformamide, dimethylsulfoxide, N-methyl-pyrrolidone, hydrocarbons and water-immiscible ethers, esters or ketones. However, other high strength liquid concentrates may be formulated by dissolving the active ingredient in a solvent then diluting, e.g., with kerosene, to spray concentration.
The concentrate compositions herein generally contain from about 0.1 to 95 parts (preferably 5-60 parts) active ingredient, about 0.25 to 50 parts (preferably 1-25 parts) surface active agent and where required about 4 to 94 parts solvent, all parts being by weight based on the total weight of emulsifiable oil.
Granules are physically stable particulate compositions comprising at least one active ingredient adhered to or distributed through a basic matrix of an inert, finely-divided particulate extender. In order to aid leaching of the active ingredient from the particulate, a surface active agent such as those listed hereinbefore can be present in the composition. Natural clays, pyrophyllites, illite and vermiculite are examples of operable classes of particulate mineral extenders. The preferred extenders are the porous, absorptive, preformed particles such as preformed and screened particulate attapulgite clay for heat expanded, particulate vermiculite and the finely-divided clays such as kaolin clays, hydrated attapulgite or bentonitic clays. These extenders are sprayed or blended with the active ingredient to form the herbicidal granules.
The granular compositions of this invention may contain from about 0.1 to about 30 parts by weight of active ingredient per 100 parts by weight of clay and 0 to about 5 parts by weight of surface active agent per 100 parts by weight of particulate clay.
The compositions of this invention can also contain other additaments, for example, fertilizers, other herbicides, other pesticides, safeners and the like used as adjuvants or in combination with any of the above-described adjuvants. Chemicals useful in combination with the active ingredients of this invention include, for example, triazines, ureas, carbamates, acetamides, acetanilides, uracils, acetic acid or phenol derivatives, thiolcarbamates, triazoles, benzoic acids, nitriles, biphenyl ethers and the like, such as:
Heterocyclic Nitrogen/Sulfur Derivatives
2-Chloro-4-ethylamino-6-isopropylamino-s-triazine
2-Chloro-4,6-bis(isopropylamino)-s-triazine
2-Chloro-4,6-bis(ethylamino)-s-triazine
3-Isopropyl-1H-2,1,3-benzothiadiazin-4-(3H)-one 2,2-dioxide
3-Amino-1,2,4-triazole
6,7-Dihydrodipyrido (1,2-d:α', 1'-c)-pyrazidiinium salt
5-Bromo-3-isopropyl-6-methyluracil 1,1'-dimethyl-4,4'-bipyridinium
2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-3-quinolinecarboxylic acid
Isopropylamine salt of 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl) nicotinic acid
Methyl 6-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-m-toluate and methyl 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-p-toluate
Ureas
N-(4-chlorophenoxy) phenyl-N,N-dimethylurea
N,N-dimethyl-N'-(3-chloro-4-methylphenyl) urea
3-(3,4-Dichlorophenyl)-1,1-dimethylurea
1,3-Dimethyl-3-(2-benzothiazolyl) urea
3-(p-Chlorophenyl)-1,1-dimethylurea
1-Butyl-3-(3,4-dichlorophenyl)-1-methylurea
-Chloro-N[(4-methoxy-6-methyl-3,5-triazin-2-yl)aminocarbonyl]-benzenesulfonamide
Methyl-2-(((((4,6-dimethyl-2-pyrimidinyl)amino)carbonyl)amino)sulfonyl)amino)sulfonyl) benzoate
Ethyl 2-[methyl-2-(((((4,6-dimethyl-2-pyrimidinyl)amino)carbonyl)amino)sulfonyl)]benzoate
Methyl-2 ((4,6-dimethoxy pyrimidin-2-yl ) aminocarbonyl)amino sulfonyl methyl) benzoate
Methyl 2-(((((4-methoxy-6-methyl-1,3,5-triazin-2yl)amino)carbonyl)amino)sulfonyl) benzoate
Carbamates/Thiolcarbamates
2-Chloroallyl diethyldithiocarbamate
S-(4-chlorobenzyl)N,N-diethylthiolcarbamate
Isopropyl N-(3-chlorophenyl) carbamate
S-2,3-dichloroallyl N,N-diisopropylthiolcarbamate
S-N,N-dipropylthiolcarbamate
S-Propyl N,N-dipropylthiolcarbamate
S-2,3,3-Trichloroallyl N,N-diisopropylthiolcarbamate
Acetamides/Acetanilides/Anilines/Amides
2-Chloro-N,N-diallylacetamide
N,N-dimethyl-2,2-diphenylacetamide
N-(2,4-dimethyl-5-[[(trifluoromethyl)sulfony]amino]phenyl]acetamide N-isopropyl-2-chloroacetanilide
2',6'-Diethyl-N-methoxymethyl-2-chloroacetanilide (aka alachlor)
2'-Methyl-6'-ethyl-N-(2-methoxypropyl-2-yl)-2-chloroacetanilide
α,α,α, -Trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine N-(1,1-dimethylpropynyl)-3,5-dichlorobenzamide
2-Chloro-N-ethoxymethyl-6'-ethylacet-o-toluidide (aka acetochlor)
2-Chloro-6'-ethyl-N-(2-methoxy-1-methylethyl)acet-o-toluidide (aka as metolachlor)
2-Chloro-N-isopropylacetanilide (aka as propachlor)
S-4-Chloro-N-isopropylcarbaniloylmethyl-O,O-dimethyl phosphorothioate (aka anilofos)
N-Butoxymethyl-2-chloro-2',6'-diethylacetanilide (aka butachlor)
3-(4-Bromo-3-chlorophenyl)-1-methoxy-1-methylurea (aka chlorobromuron)
N-Chloroacetyl-N-(2,6-diethylphenyl)glycine (aka diethatyl)
2-Chloro-N-(2-methoxyethyl)acet-2',6', -xylidide (aka dimethachlor)
Preferred are herbicide mixtures of the 3-pyrazolyloxypyridazine and one or more of a just-mentioned 2-chloroacetanilides. Especially, preferred 2-chloroacetanilides include acetochlor, alachlor, butachlor and metolachlor. The preferred ratio of pyridazine to 2-chloroacetanilide is between 10:1 and 1:10.
Acids/Esters/Alcohols
2,2-Dichloropropionic acid
2-Methyl-4-chlorophenoxyacetic acid
2-Dichlorophenoxyacetic acid
Methyl-2-[4-(2,4-dichlorophenoxy)phenoxy]propionate
3-Amino-2,5-dichlorobenzoic acid
2-Methoxy-3,6-dichlorobenzoic acid
2,3,6-Trichlorophenylacetic acid
N-1-naphthylphthalamic acid
Sodium 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate
4,6-Dinitro-o-sec-butylphenol N-(phosphonomethyl) glycine and its salts
Butyl 2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]-phenoxy]propanoate
Ethers
2,4-Dichlorophenyl-4-nitrophenyl ether
2-Chloro-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrodiphenyl ether
5-(2-Chloro-4-trifluoromethylphenoxy)-N-methyl sulfonyl-2-nitrobenzamide
1'-(Carboethoxy) ethyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate
Miscellaneous
2,6-Dichlorobenzonitrile
Monosodium acid methanearsonate
Disodium methanearsonate
2-(2-chlorophenyl)methyl-4,4-dimethyl-3-isoxazolidinone
7-Oxabicyclo (2.2.1) heptane, 1-methyl-4-(1-methylphenylmethoxy)-, exo
Fertilizers useful in combination with the active ingredients include, for example, ammonium nitrate, urea, potash and superphosphate. Other useful additaments include materials in which plant organisms take root and grow such as compost, manure, humus, sand and the like.
It is common practice to use various antidotal or safening compounds to reduce the phytotoxicity of certain herbicides to various crops, especially corn. Accordingly, together with the 3-pyrazolyl-oxypyridazines of the present invention, alone or in combination with a herbicidal 2-chloroacetanilide, one can include in the formulations a safening amount of a suitable antidotal compound. Among suitable safeners for inclusion in the formulations of the present invention are fluorazole, cyometrinal, oxabetrinil, dichlormid, AD-67, 1,3-oxazolidine dichloroacetamides and other compounds known in the art as antidotes for herbicides, especially for corn one preferred safener is 3-(dichloroacetyl)-5-(2-furanyl)-(2,2-dimethyl oxazolidine.
Herbicidal formulations of the types described above are exemplified in several illustrative embodiments below.
______________________________________ Weight Percent______________________________________I. Emulsifiable ConcentratesA. Compound of Example No. 1 11.0Free acid of complex organic 5.59phosphate or aromatic or ali-phatic hydrophobe base (e.g.,GAFAC RE-610, registeredtrademark of GAF Corp.)Polyoxyethylene/polyoxypropylene 1.11block copolymer with butanol (e.g.,Tergitol XH, registered trademarkof Union Carbide Corp.)Phenol 5.34Monochlorobenzene 76.96 100.00B. Compound of Example No. 2 25.00Free acid of complex organic 5.00phosphate or aromatic or ali-phatic hydrophobe base (e.g.,GAFAC RE-610)Polyoxyethylene/polyoxyproplene 1.60block copolymer with butanol(e.g., Tergitol XH)Phenol 4.75Monochlorobenzene 63.65 100.00II. FlowablesA. Compound of Example No. 3 25.00Methyl cellulose 0.3Silica Aerogel 1.5Sodium lignosulfonate 3.5Sodium N-methyl-N-oleyl taurate 2.0Water 67.7 100.00B. Compound of Example No. 4 45.0Methyl cellulose 0.3Silica aerogel 1.5Sodium lignosulfonate 3.5Sodium N-methyl-N-oleyl taurate 2.0Water 47.7 100.00III. Wettable PowdersA. Compound of Example No. 5 25.0Sodium lignosulfonate 3.0Sodium N-methyl-N-oleyl-taurate 1.0Amorphous silica (synthetic) 71.0 100.00B. Compound of Example 6 80.00Sodium dioctyl sulfonsuccinate 1.25Calcium lignosulfonate 2.75Amorphous silica (synthetic) 16.00 100.00C. Compound of Example No. 7 10.0Sodium lignosulfonate 3.0Sodium N-methyl-N-oleyl-taurate 1.0Kaolinite clay 86.0 100.00IV. DustsA. Compound of Example No. 8 2.0Attapulgite clay 98.0 100.00B. Compound of Example No. 9 60.0Montmorillonite 40.0 100.00C. Compound of Example No. 10 30.0Ethylene glycol 1.0Bentonite 69.0 100.00D. Compound of Example No. 13 1.0Diatomaceous earth 99.0 100.00V. GranulesA. Compound of Example No. 1 15.0Granular attapulgite (20/40 mesh) 85.0 100.00B. Compound of Example No. 2 30.0Diatomaceous earth (20/40) 70.0 100.00C. Compound of Example No. 3 1.0Ethylene glycol 5.0Methylene blue 0.1Pyrophyllite 93.9 100.00D. Compound of Example No. 4 5.0Pyrophyllite (20/40 95.0 100.00______________________________________
When operating in accordance with the present invention, effective amounts of the compounds of this invention are applied to the soil containing the seeds, or vegetative propagules or may be incorporated into soil media in any convenient fashion. The application of liquid and particulate solid compositions to the soil can be carried out by conventional methods, e.g., power dusters, boom and hand sprayers and spray dusters. The compositions can also be applied from airplanes as a dust or a spray because of their effectiveness at low dosages.
The exact amount of active ingredient to be employed is dependent upon various factors, including the plant species and stage of development thereof, the type and condition of soil, the amount of rainfall and the specific compounds employed. In selective preemergence application or to the soil, a dosage of from about 0.02 to about 11.2 kg/ha, preferably from about 0.1 to about 5.60 kg/ha, is usually employed. Lower or higher rates may be required in some .instances. One skilled in the art can readily determine from this specification, including the above examples, the optimum rate to be applied in any particular case.
While the illustrative embodiments of the invention have been described with particularity, it will be understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and descriptions set forth hereinabove but rather that the claims be construed as encompassing all the features of patentable novelty which reside in the present invention, including all features which would be treated as equivalents thereof by those skilled in the art to which the invention pertains. | Disclosed are certain 5-methoxypyridinyloxypyridazines, compositions thereof which are herbicidal and methods of using such compositions for controlling undesired plants.
Intermediates useful in preparing the pyridinyloxypyridazines are also disclosed. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority of U.S. provisional application No. 62/045,708, filed Sep. 4, 2014, the contents of which are herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a weapon handguard and the method of manufacture thereof. More particularly, to the heat mitigating capabilities of the thermoplastic weapon handguard, and the method of molding during the manufacturing process.
[0003] Existing aluminum handguards absorb extremely high levels of radiant barrel heat generated by firing the rifle and transfer that heat through the handguard directly to the operator. Radiant heat from the barrel or suppressor can rapidly reach >800° F. As heat transfer occurs, aluminum handguards can quickly exceed temperatures over 200° F., well above the pain threshold for human skin and can literally burn the skin. This heat transfer creates significant degradation of shooter effectiveness, a measurable decrease in accuracy over longer distances, and loss of basic control during maneuver. These effects, either singularly or in combination reduce the overall effectiveness of the shooter.
[0004] Handguards mitigate or outright negate nearly all of the heat related problems of current handguards. They remain comfortable to the touch, well below the pain threshold for human skin while constantly tested against standard protocols of 210 rounds fired on automatic. By removing heat from the shooting equation, the shooter can focus on marksmanship principles that improve accuracy during sustained engagements and control during maneuver.
[0005] As can be seen, there is a need for an improved insulation unit for rifles.
SUMMARY OF THE INVENTION
[0006] In one aspect of the present invention, a thermally protective handguard for a firearm, comprises at least one handguard member comprising a plurality of ventilation apertures defined between an outer surface and an inner surface of the handguard member, and a plurality of elevated ridges extending upwardly from the outer surface of the handguard. The handguard may further comprise a first and a second handguard member, the first handguard member is adapted to cover an upper portion of a barrel of the weapon, the second handguard member is adapted to cover a lower portion of the weapon barrel. In another aspect of the invention, the handguard assembly may further comprise a mounting ring assembly, having a top mounting ring and a bottom mounting ring, the top mounting ring comprising a plurality of holes for receiving a fastener to secure the first handguard member to the top mounting ring.
[0007] In other aspects of the invention, the mounting ring assembly further comprises an annular groove defined in an inner surface of the top mounting ring and the bottom mounting ring. The mounting ring assembly providing a clamping attachment between the top mounting ring and the bottom mounting ring.
[0008] In another aspect of the invention, the handguard assembly may further comprise a barrel nut having a substantially ring shaped cylinder and a plurality of slots defined in an outer surface of the barrel nut. The barrel nut may be clamped by the mounting ring assembly within the annular groove.
[0009] In yet another aspect of the invention, the handguard member is formed from a nano-enhanced polymeric material comprising: a composition of carbon tube nano fiber material, and micro-sphere glass material.
[0010] These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 : Is a perspective view of a short handguard.
[0012] FIG. 2 : Is a perspective view of a long upper handguard.
[0013] FIG. 3 : Is a perspective view of a long lower handguard.
[0014] FIG. 4 : Is a perspective view of a top mounting ring.
[0015] FIG. 5 : Is a perspective view of a bottom mounting ring.
[0016] FIG. 6 : Is a side elevation view of a barrel nut.
[0017] FIG. 7 : Is an end view of the barrel nut from a receiver end of the barrel nut.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
[0019] Broadly, an embodiment of the present invention provides technology advancements that make it possible to solve long standing heat related problems through the development and use of advanced materials with comparable strength characteristics of traditional aluminum weapon handguard systems, while still capable of protecting the shooter from related radiant barrel heat. The present invention includes a rifle handguard that is distinguished by high heat protective qualities, lightweight design, durability, and resistance to extreme environments. But most importantly, it serves as thermal insulation that mitigates most or outright negates nearly all of the heat related attributes of the current handguard systems, while maintaining existing battle tested design of current weapons handguard systems.
[0020] The present invention utilizes high grade engineered advanced thermoplastic material to upgrade the design and capabilities of existing weapon handguard systems. This material maintains critical properties such as strength, toughness, operational durability and abrasion resistance. The present invention allows significant airflow to cool the barrel to within the manufacture specifications. The handguard of the present invention promotes and facilitates the attachment of peripheral device attachments, while being reconfigurable and modular in design and practical use. The handguard does not in negatively affect the operation of the weapons system, such as its accuracy, function, reliability, or cooling.
[0021] The present invention includes: a combination of polymeric materials that includes one or more types of fibers that are used to form any portion of the handguard; mounting rails or peripheral devices; a combination of polymeric materials that includes one or more types of nanoparticles that are used to form any portion of the handguard, mounting rails or peripheral devices; using polymeric-based materials with one or more nanoparticles, where the nanoparticles introduce increased or decreased multiple functionalities such as heat-insulation+/−strength+/−toughness+/−hardness+/−electrical conductivity+/−sensing.
[0022] The present invention further includes a method of molding nano-enhanced polymeric materials into the desired shapes and sizes, in a plurality or combination of colors; a method of molding nano-enhanced polymeric materials into the desired shapes and sizes, to include labels, logos, and any their desired marking; a method of forming the polymeric-based materials and material configurations through use of a mold; a method of forming the polymeric-based materials and material configurations through use of a mold that may include heat and/or pressure and/or catalysts sufficient to cause an alteration of the material such that it facilitates the forming of such materials in a mold; and a method of forming the polymeric-based materials and material configurations through use of a mold that may include heat and/or pressure and/or catalysts sufficient to cause an alteration of the material such that it facilitates the hardening or curing of such materials in a shape defined by the mold.
[0023] Referring now to the Figures, the present invention may comprise the following components: an Upper Handguard-Short as seen in reference to FIG. 1 ; an Upper Handguard-Long 12 , as seen in reference to FIG. 2 ; a Lower Handguard-Long, FIG. 3 ; an Upper Mounting Ring 16 , as seen in reference to FIG. 4 ; a Bottom Mounting Ring 18 , as seen in reference to FIG. 5 , and a Barrel Nut 20 , as seen in reference to FIGS. 6 and 7 .
[0024] The long free floating handguard 12 & 14 is designed for the M4A1 Carbine so that the only point of contact between the rifle and the handguard 12 & 14 is at the barrel nut 20 . In this configuration, there is no interference with the barrel while shooting. Two piece designs allows the upper handguard 12 and lower handguard 14 hand guards to be installed without removing the front site of the rifle, clamping securely to the barrel nut 20 with only two locking screws, saving time and maintenance costs. The upper portion of the handguard 12 may be made from the highest performing melt-process-able thermoplastic material with superior resistance to elevated temperatures. The material is capable of performing under severe stress conditions at continuous temperatures to 500° F. (260° C.). It's extremely low coefficient of linear thermal expansion and high creep resistance deliver excellent dimensional stability over its entire use range. It has a Tg (glass transition temperature) of 537° F. (280° C.).
[0025] The handguard 12 is approximately 13 inches long and covers the top half of the weapons barrel. To ensure proper fitting on automatic rifle (AR) weapon variants, a slot 13 may be cut into the top of the handguard 12 to accommodate the front sight and gas tube assemblies.
[0026] The mounting rail incorporated into the top and sides of the upper handguard 12 carries the official title MIL-STD-1913. It is also known by the NATO designation STANAG 2324. This bracket is used on various weapons systems in order to provide a standardized mounting platform for telescopic sights and other accessories, such as tactical lights and laser sighting modules. The upper handguard 12 assembly attaches to the weapon's upper receiver by means of an attachment bracket discussed below. Preferably, the upper handguard 12 may have a plurality of holes 11 on each side for mounting screws, four equally spaced on each side, for attaching with corresponding holes 15 defined the lower portion 14 .
[0027] The lower portion of the handguard 14 is made from the highest performing melt-process-able thermoplastic material with superior resistance to elevated temperatures. The material is capable of performing under severe stress conditions at continuous temperatures to 500° F. (260° C.). It's extremely low coefficient of linear thermal expansion and high creep resistance deliver excellent dimensional stability over its entire use range. It has a Tg (glass transition temperature) of 537° F. (280° C.).
[0028] The handguards 10 , 12 , 14 are formed of a thermoplastic base material such as, a carbon fiber nano-tube material, and glass micro-spheres.
[0029] The lower handguard 14 is approximately 13 inches long and covers the bottom half of the weapons barrel. The mounting rail incorporated into the bottom handguard lower carries the official title MIL-STD-1913. It is also known by the NATO designation STANAG 2324. This bracket is used on various weapons systems in order to provide a standardized mounting platform for telescopic sights and other accessories, such as tactical lights and laser sighting modules. The lower handguard assembly 14 attaches to the upper handguard 12 be means of holes 14 and a mounting screws, four equally spaced on each side, for attaching the lower portion 14 .
[0030] The upper and lower handguards 10 , 12 , 14 may further comprise a plurality of ventilation apertures 23 defined along the longitudinal length of the handguards. Preferably, the apertures 23 are defined along top and side surfaces to permit ventilation and cooling airflow around the barrel of the weapon. The plurality of ventilation apertures 23 defining a ventilation surface area for the handguard 10 , 12 , 14 .
[0031] Additionally, the handguards 10 , 12 , 14 may also comprise a plurality of elevated ridges 24 extending upwardly from the outer surface of the handguards. The ridges 24 provide an increased surface area for the radiation and dispersion of heat that may be transferred from the barrel to the handguards 10 , 12 , 14 . Some of the ridges 24 may be intersected by the apertures 23 to provide a combined cooling effect.
[0032] The barrel nut 20 serves to securely attach the rifle barrel to the upper receiver 12 and serves as the mounting platform for the Mounting Ring 16 & 18 . The barrel nut 20 comprises an annular ring for surrounding the barrel of the weapon and is secured to the weapon at an aft end of the barrel, proximal to the receiver of the weapon. The barrel nut 20 may further comprise four slots 21 that are preferably equally spaced around the nut 20 that act to allow tightening using a standard AR-15/M-4 barrel wrench.
[0033] The mounting ring 16 & 18 is a two part assembly, comprising an upper mounting ring 16 and a lower mounting ring 18 . The upper and lower mounting rings 16 & 18 are preferably made from aluminum that serves as an attachment base for the thermoplastic handguard assembly 12 . The mounting ring 16 & 18 also serves as the mounting attachment to the weapon by clamping onto the barrel nut assembly 20 . This is accomplished by two screws applying pressure evenly over the barrel nut 20 that is recessed into a grove 25 defined in both the upper 16 and lower 18 portions of the mounting ring.
[0034] The Mounting Ring Top 16 may house six screws 19 that secure the thermoplastic assembly 12 to the mounting ring 16 . The top portion of the mounting ring 16 may also have two optional studs 17 on the weapon receiver side at the top that acts to prevent counter rotation of the handguard assembly 12 .
[0035] As seen in reference to FIG. 1 , the short handguard 10 is a replacement for the M4A1 Service Carbine. The MIL-STD-1913 rail or STANAG 2324 handguard is a quick and simple two piece drop in design that attaches through use of the weapon's existing delta ring. The short handguards 10 are not free floated. The short handguard 10 is made from the highest performing melt-processable thermoplastic material with superior resistance to elevated temperatures. The material is capable of performing under severe stress conditions at continuous temperatures to 500° F. (260° C.). It's extremely low coefficient of linear thermal expansion and high creep resistance deliver excellent dimensional stability over its entire use range. It has a Tg (glass transition temperature) of 537° F. (280° C.). The short handguard 10 is approximately seven (7) inches long and covers the weapons barrel.
[0036] The mounting rail incorporated into the bottom handguard lower carries the official title MIL-STD-1913. It is also known by the NATO designation STANAG 2324. This bracket is used on various weapons systems in order to provide a standardized mounting platform for telescopic sights and other accessories, such as tactical lights and laser sighting modules.
[0037] The Handguard System described and claimed herein, is the next generation in tactical rifle hand guards due to the innovative design that utilizes high grade engineered thermoplastic material and a special mix of other advanced materials to upgrade the existing battle tested design of the Picatinny Rail system. The integration of thermo plastic materials enhances critical properties such as strength, toughness, operational durability and abrasion resistance.
[0038] The present invention serves as thermal insulation to the user that mitigates or outright negates nearly all of the heat related attributes of the current rail system. Additionally, the hand-guard/rail system does not in any way affect the operation of the weapons system, such as accuracy, function, reliability, or cooling. The rail system design allows the weapon to vent and cool in accordance with the manufacturers specifications, thus preventing safety hazards such as ammunition cook offs. Using a mold-able thermo plastic material system allows much more innovative designs to emerge in the future, adaptation to a wider variety of weapons, and will reduce overall weight. The handguard 12 , 12 , 14 may be designed for the M4A1 Carbine in which the only point of contact between the rifle and the handguard is at the barrel nut 20 . In this configuration, it is the barrel that is free floated, and as such nothing is touching or interfering with the barrel while shooting. The length of handguard 12 & 14 may be about 13″ long and leave the gas bloc or front sight post exposed. Quad rail free float handguards feature four full length Picatinny attachment points for accessories such as tactical lights, fore grips, bipods, and sling swivels. The present invention may be designed for military, law enforcement, and professional shooters, the handguard virtually erases the negative high heat aspects related with sustained rates of fire. Negating the burning hand distraction allows the shooter to hold the rifle as it was designed with a focus on control and accuracy.
[0039] The method of making and attaching the present invention may include the following: attaching the mounting rails to the handguard, using a plurality of mating and/or interlocking grooves, combined with permanent or temporary fasteners; molded-in or formed-in threaded inserts or other receptacles designed to work in conjunction with a mating part of a fastener system; fastener system used to fasten multiple parts of the handguard together with or without the use of hand tools; fastener system used to attach the handguard to the firearm with or without the use of hand tools; a handguard and/or attachment system that provides enough heat insulating effect, such that it does not reach a temperature on the external surface after normal/heavy operational use of the firearm to which it is attached, that causes the user to loosen or alter their grip on the handguard and/or attachment system; a handguard and/or attachment system that provides enough heat-insulating effect, such that it does not reach a temperature on the external surface that causes burns or scarring or material alteration when touched during or after normal/heavy operational use of the handguard to which it is attached; a base handguard without any hand tools, using a permanent or temporary system of fasteners; the base handguard without the use hand tools, using a permanent or temporary system of fasteners; assembling the peripheral device mounting system without the use of hand tools, using a permanent or temporary system of fasteners; using multiple layers of materials to form the handguard or mounting rails or peripheral devices; forming or integrating multiple material layers during the manufacturing process; forming or integrating multiple material layers during the assembly or attachment process(es).
[0040] The present invention solves the problem related to handguard heating and utilizes a material that does not transfer radiant rifle barrel heat through the handguard to the operator. Handguard development is based on the standard infantryman's basic load (210 rounds) as the primary objective. The handguard should allow the shooter to fire that basic load and still maintain positive control of his weapon, and by positive control, accuracy at all tactical ranges. New handguards may remain relatively comfortable to the touch even as barrel temperatures push to >800 F. This material also withstands the operational environment and abuses inflicted on a small arms weapons system. In order to provide a stable platform, the rail may not flex as the barrel heats and cools.
[0041] It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. | Heat Mitigating handguards for rifles and method of manufacture thereof. The handguards are made from advanced thermoplastics that mitigate heat transfer, are 20% lighter than aluminum with like strength characteristics. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/177,921, filed Jan. 25, 2000, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The subject disclosure relates to devices for aiding female urinary incontinence, and more particularly to an improved female urine collection device which comfortably and discretely conforms to the female body and protects against leakage.
[0004] 2. Background of the Related Art
[0005] Approximately eleven million women in America experience involuntary leakage of urine. Such a condition erodes their quality of life because medical, emotional and social problems often accompany incontinence. Skin rashes, urinary tract infections, sleep disturbances, restricted social interactions, reduced sexual activity, loss of self-esteem and depression are only a few of the typical symptoms associated with incontinence.
[0006] For many women, the condition is a consequence of aging and approximately half of the women in nursing homes are incontinent in varying degrees. Further, hospitalized patients, such as those in traction or who are otherwise bedridden must empty their bladder at bedside. Moreover, circumstances may simply make a restroom break inconvenient such as when working in outer space. To accommodate such conditions, it is desirable to provide a device which can comfortably and reliably collect, retain and empty, or channel urine so as to prevent embarrassing and untimely leakage.
[0007] Several devices have been developed to perform this function. For example, U.S. Pat. No. 3,528,423 to Lee discloses a female incontinence device having an intravaginal stabilizer bar with projections for holding a face plate in place. The face plate has grooves to conform to the major and minor labia, respectively. The face plate further defines an outlet for allowing urine to collect in a reservoir. A drain tube may terminate in a plug or connect to a suitable receptacle. Buttons on the face plate provide anchors for a harness to secure the device to the patient's body.
[0008] A further example includes U.S. Pat. No. 5,370,637 to Brodeur, which discloses a female urination aid to facilitate urination by females in a substantially upright position. A base defines an oval center opening which fits around a patient's vulva. The opening has upper contours and a seal to engage the labia. Finger pads on the base provide an area for the patient to apply pressure to effectuate proper engagement of the seal. An absorbent pad disposed at the bottom of the base can be used as a germicidal and deodorizing wipe. A collapsible fluid guide extends from the base and terminates at an outlet to take urine away from the patient. The fluid guide has an inner liner surrounded by an accordion boot.
[0009] Still further, U.S. Pat. No. 4,986,823 to Anderson et al. discloses a device for directing a flow of urine from a female. The device includes a body having a collector surrounding the urethral meatus and a pair of limbs extending internally of the vagina through the vaginal orifice. A collection tube is connected to the collector to communicate the urine into a reservoir. Further, the collector includes torsion members to provide a spring force to separate the limbs. An applicator holds the limbs together for easy insertion.
[0010] U.S. Pat. No. 5,336,208 to Rosenbluth et al. discloses a first embodiment having a disposable urinary incontinence pad with a base that has an adhesive layer for providing a fluid tight seal and occlusion against the urethral meatus and increasing retention against the vestibule of the vulva. Lateral edges of the base and an anterior end of the pad are tucked under the labia minora to enhance retention. Moreover, the adhesive layer can be extended onto the labia-engaging surface to further enhance the stability of the device. A handle in the form of a ring or loop of string facilitates removal. A second embodiment has a short protuberance to be received at least partially within the urethral meatus. A third embodiment has a flexible bladder filled with gel. The bladder conforms to the anatomical structure of the external female genitalia, filling the interlabial space, and sealing against the urethral meatus with the aid of an adhesive.
[0011] Also, U.S. Pat. No. 4,484,917 to Blackmon discloses a female external catheter formed from a main body having an inlet for receiving urine. An adhesive layer, surrounding the inlet, secures the inlet about the urethral meatus. A stabilizer provides a rigid backing for the adhesive layer. An outlet tube channels urine into a collection bag. U.S. Pat. No. 4,822,347 to MacDougall discloses a female incontinence device with a tubular sheath integral with a funnel and a urine conduit. A pad of adhesive material secures an entry portion around the urethral meatus. The sheath is a highly stretchable latex rubber in order to absorb the energy created by urine surges and, thus, prevent stress upon the adhesive seal. The conduit leads to a leg bag or urine collection vessel.
[0012] Notwithstanding the above teachings, there is a need for an improved female urinary incontinence device. Typically, prior art devices are ill-suited for their intended use due to discomfort and potential for leakage, particularly for ambulatory patients. In light of the foregoing, a need exists for a female urinary incontinence device which is comfortable and secure for bedridden and ambulatory patients.
SUMMARY OF THE DISCLOSURE
[0013] The subject disclosure is directed to a device to accommodate female urinary incontinence. The device includes a reservoir defining a recess for receiving urine. The reservoir has a rim configured to adhere the device to the periurethral surface and secure its position. A securement tab depends from the device for engagement in the vaginal opening to further secure the position and orientation of the device. Means for selectively draining the reservoir are also provided. Such means preferably includes a selectively actuable check valve. In another embodiment, an adhesive flange depends from the rim for engaging the labia minora. In use, an adhesive coating is applied to the tab and a string is attached to the tab. The tab has a plurality of hinges to allow the tab to conform to the vaginal opening.
[0014] The method for collecting female urine includes the step of providing a collection device having a securing portion with a rim defining an inlet and configured to surround a urethra and engage a labia. A tab is adjacent to the rim and configured for insertion into a vaginal opening to secure a position of the securing portion. The method further includes the steps of applying an adhesive to the rim, adhering the rim to the periurethral surface to create a seal therewith and inserting the tab into the vaginal opening.
[0015] These and other unique features of the system disclosed herein will become more readily apparent from the following description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] So that those having ordinary skill in the art to which the disclosed device appertains will more readily understand how to make and use the same, reference may be had to the drawings wherein:
[0017] [0017]FIG. 1 is a front perspective view of a first urinary incontinence device constructed in accordance with a preferred embodiment of the subject disclosure;
[0018] [0018]FIG. 2 is a rear perspective view of the urinary incontinence device of FIG. 1;
[0019] [0019]FIG. 3 is a side-elevational view of the urinary incontinence device of FIG. 1 during insertion of the securement tab into the vaginal opening of a patient;
[0020] [0020]FIG. 4 is a side-elevational view of the urinary incontinence device of FIG. 1 fully disposed in an operational position on a patient;
[0021] [0021]FIG. 5 is a side-elevational view of the urinary incontinence device as in FIG. 4 with the reservoir shown in partial cross-section as urine is drained therefrom;
[0022] [0022]FIG. 6 is a perspective view of a second urinary incontinence device constructed in accordance with a preferred embodiment of the subject disclosure;
[0023] [0023]FIG. 7 is a side-elevational view of the urinary incontinence device of FIG. 6 in an operational position on a patient;
[0024] [0024]FIG. 8 is a partial cross-sectional view of the urinary incontinence device of FIG. 6 in an operational position on a patient as urine is received in the reservoir; and
[0025] [0025]FIG. 9 is an illustration of a urine collection system constructed in accordance with a preferred embodiment of the subject disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] The subject disclosure relates to an improved system for capturing the urine of women. The system is particularly applicable to women who are incontinent or bed-ridden, although the system may be utilized in many circumstances in which insertion of a catheter into the urethra is contra-indicated for medical reasons or such as during a long journey when a bathroom is unavailable, as would be readily appreciated by those skilled in the art.
[0027] The present disclosure overcomes many problems of the prior art associated with female urinary aids. The advantages, and other features of the system disclosed herein, will become more readily apparent to those having ordinary skill in the art from the following detailed description of certain preferred embodiments of the invention taken in conjunction with the figures which set forth representative embodiments of the present disclosure.
[0028] Referring to FIG. 1, there is shown urinary incontinence device constructed in accordance with a preferred embodiment of the subject disclosure and designated generally by reference numeral 100 . In general, the device 100 includes a securing portion 110 to sealingly engage a patient, a carriage 130 for storing urine and a drain tube 140 . In operation, the patient is ambulatory yet micturation is captured for subsequent release. The device 100 is secured in place as easily as a tampon and remains hidden under the patient's clothing in a manner superior to diapers and pads. The drain tube 140 allows the patient to selectively empty the reservoir body.
[0029] With continuing reference to FIG. 1, the securing portion 110 includes an elongated tab 112 which serves to secure the device 100 in place. The tab 112 is sized and shaped for insertion into the vaginal opening 180 of the patient. Preferably, the tab 112 is constructed of nylon, styrene, flexible polyvinyl plastic or the like. Hinges 114 integral with the tab 112 create flexibility which helps the tab 112 conform to the patient's anatomy. In one embodiment, the upstanding tab 112 is coated with a bio-compatible adhesive to secure placement of the tab 112 and therefore the device 100 in place. The bio-compatible adhesive preferably does not alter the bacteria flora balance of the vaginal track. A string 116 in combination with the hinges 114 facilitates easy removal of the tab 112 from the vaginal opening 180 . In one embodiment, the adhesive on the tab 112 is pressure sensitive and contains a hydrophilic resin. Further, the coating weight of the adhesive on the tab 112 should be set to maximize wet adhesion and wet shear resistance. In another embodiment, a water soluble adhesive based upon polyvinylmethyl ether may be used. In yet another embodiment, the tab 112 has a plurality of protuberances (not shown) to engage the vaginal rugae and help secure the tab 112 in place.
[0030] The securing portion 110 also includes a rim 118 sized and configured to sealingly engage the labia minora of the patient (see FIG. 4). The rim 118 defines an inlet 120 which surrounds the urethra of the patient. Preferably, the tab 112 is disposed adjacent the rim 118 and projects at approximately a 45-50 degree angle so that it corresponds with that of the typical vaginal axis. Preferably, the rim 118 is composed of a malleable material, such as rubber, so that it readily conforms to the anatomy of the patient. It is envisioned that in order to effectively seal around the urethra, the rim 118 is coated with a bio-compatible adhesive appropriate to the corresponding contact area with the patient. In one embodiment, the adhesive of the rim 118 swells and becomes sticky upon contact with moisture. Further, the rim 118 may have a groove (not shown) which is filled with adhesive. In a preferred embodiment, the groove has a depth of 0.0015 to 0.0020 inches.
[0031] The securing portion 110 also includes a flange 122 surrounding the rim 118 . The flange 122 engages the labia minora to help secure the rim 118 in place on the patient. Preferably, the flange 122 is constructed of nylon, styrene, flexible polyvinyl plastic or the like. In one embodiment, a sticky adhesive is hot melt onto the flange 122 to create the securement of the flange 122 to the labia minora. In another embodiment, the flange 122 is provided with double-sided tape. In still another embodiment, the flange 122 is provided with adhesive by a vacuum transfer process. The adhesive should be bio-compatible with respect to the contact area. Further, the adhesive may contain a moisture absorbent component such as carboxy methyl cellulose to enhance adhesion. In yet embodiment, no flange is required.
[0032] Still referring to FIG. 1, the carriage 130 depends from the rim 118 of the securing portion 110 to collect urine as it evacuates the patient. Preferably, the carriage 130 is sized and configured for free movement of the patient and concealment under traditional clothing. When empty as shown, the carriage 130 compresses to maximize comfort and minimize obtrusiveness. It is envisioned that the top surface 132 of the carriage 130 is a flexible polyvinyl plastic in order to provide shape and support. In one embodiment, a plurality of channels 134 in the top surface 132 of the carriage 130 provide additional structural support. A plurality of bellows portion 136 depends from the top surface 132 of carriage 130 to allow for expansion as urine collects therein. The bellows portion 136 is preferably elastomeric in construction.
[0033] A drain tube 140 depends from carriage 130 for allowing the patient to release urine collected therein. The drain tube 140 has a manual release valve 142 to allow selective opening of the drain tube 140 by the patient. Alternatively, the drain tube 140 terminates with a check valve that opens and closes with the use of a pull tab (not shown). In yet another embodiment, the drain tube 140 terminates in a collection bag (not shown). In still another embodiment, the drain tube 140 includes an internal pinch valve.
[0034] It is also envisioned that the drain tube 140 allows cleansing and medicating of the vaginal area without removal of the device 100 . For cleansing, the patient would introduce a cleaning solution such as water into the carriage 130 by way of the drain tube 140 . For medicating, the patient would introduce by way of the drain tube 140 a therapeutic solution. The therapeutic solution would be varied according to the condition of the patient such as an anti-inflammatory agent, an antibiotic, a fungicide or the like.
[0035] Referring to FIG. 2, the string 116 is preferably attached to a distal end 124 of the upstanding tab 112 to facilitate easy removal of the device 100 by minimizing the effort required to remove the tab 112 . In one embodiment, the top surface 132 of the carriage 130 contains a leak proof air vent 126 . The air vent 126 allows efficient emptying of the carriage 130 without creating a vacuum effect therein.
[0036] It should be recognized that although “patient” is used throughout the specification to refer to a woman utilizing the subject system, the patient may be ambulatory and other than minor urinary incontinence perfectly healthy. For simplicity, the subject application describes a patient inserting and removing the subject invention, however, it is also envisioned that a caregiver may insert, empty and remove the device 100 . Preferably, the patient uses their hands to insert the device 100 .
[0037] Referring to FIG. 3, to apply the device 100 , a patient inserts the tab 112 into the vaginal opening along the direction indicated by arrow 170 . If the adhesives are coated with silicone coated release paper (not shown), the patient removes the silicone coated release paper or similar non-sticking packaging in preparation for use of the device 100 .
[0038] Referring to FIG. 4, during application the patient fully engages the tab 112 within the vaginal opening to locate the rim 118 around the urethra. The device 100 is secured in place sufficiently to withstand greater than 100 mmHg output pressure of the urethral sphincter and contain up to 400 ml of micturation. As a result, when the bladder evacuates through the urethra, the urine passes through the inlet 120 in the direction indicated by arrows 172 into the carriage 130 .
[0039] It is envisioned that the tab 112 can be held in place due to the pressure from the wall of the vaginal opening. When the tab 112 is coated with a pressure sensitive adhesive, the pressure from the wall of the vaginal opening will create additional adhesive tension. Similarly, if the tab 112 has protuberances (not shown) provided thereon, the pressure from the wall of the vaginal opening will create additional structural tension with the protuberances.
[0040] Still referring to FIG. 4, when pressure is applied on the rim 118 , it conforms to the surface of the labia minora. Preferably, an adhesive on the rim 118 swells and becomes sticky to create a periurethral leak-proof seal. As the flange 122 engages the labia minora, the rim 118 is further affixed about the urethra. Preferably, the flange 122 is pressed into place to engage an adhesive thereon in contact with the labia minora.
[0041] The forward portion of the carriage 130 and the drain tube 140 can be flexed to rest against the patient's lower abdomen. Thus, the obtrusiveness of the device 100 is minimized. As the carriage 130 collects urine, the plurality of bellows portion 136 expands outwardly in the direction indicated by arrow 174 . When the carriage 130 is full of urine, the urine may splash undesirably while a patient moves. Further, the splashing may cause partial leakage about the rim 118 . Under such circumstances, it is envisioned that a reticulated polyurethane foam (not shown) in the carriage 130 will absorb the urine to prevent sloshing and the associated undesirable effects and will add only minimal weight.
[0042] Referring to FIG. 5, to empty the carriage 130 , the patient positions the drain tube 140 over a toilet and opens or removes the valve 142 to allow the urine to exit out of the drain tube 140 in the direction indicated by arrow 176 . The patient may be lying down, sitting or standing to evacuate the carriage 130 . As urine exits, air enters air vent 126 in the direction indicated by arrow 178 and the plurality of bellows portion 136 compresses in the direction indicated by arrow 180 . When evacuation of the carriage 130 is complete, the drain tube 140 is again blocked by the valve 142 and the patient can once again return to normal activity. It is envisioned that the patient may apply the device 100 and wear it for extended periods while evacuating the carriage 130 multiple times as may be required. When removal of the device 100 is desired, the patient can grasp the string 116 and remove the tab 112 from the vaginal opening. If the rim 118 and flange 122 are provided with adhesives, they can be manually peeled away from the periurethral surface and the labia minora, respectively.
[0043] Referring to FIG. 6, another device constructed in accordance with the subject disclosure is illustrated and designated generally by reference numeral 200 . In general, device 200 includes a securing portion 210 to sealingly engage a patient, a reservoir body 210 for storing urine and a drain (not shown). In operation, the patient is ambulatory, the device 200 remains hidden and the patient can selectively empty the reservoir body.
[0044] The securing portion 210 includes an elongated tab 212 which serves to secure the device 200 in place. Preferably, the hinges 214 create flexibility which helps the tab 212 conform to the patient's anatomy. The upstanding tab 212 is coated with a bio-compatible adhesive to further secure placement of the tab 212 and therefore the device 200 in place.
[0045] The securing portion 210 also includes a rim 218 sized and configured to sealingly engage the periurethral surface of the patient. The rim 218 defines an inlet 220 which surrounds the urethra of the patient. It is envisioned that in order to effectively seal around the urethra, the rim 218 is malleable and coated with an adhesive. In one embodiment, the adhesive of the rim 218 swells and becomes sticky upon contact with moisture.
[0046] The securing portion 210 also includes a flange 222 surrounding the rim 218 . The flange 222 engages the labia minora to help secure the rim 218 in place periurethrally on the patient. Preferably, a sticky adhesive is hot melt or vacuum transferred onto the flange 222 to create the securement of the flange 222 to the labia minora. In another embodiment, the flange 222 is provided with double-sided tape.
[0047] Referring now to FIG. 7, the reservoir body includes a diaphragm 230 depending from the rim 218 to collect urine as it evacuates the patient. Preferably, the diaphragm 230 is sized and configured to be contained within the flange 222 when empty. Further, the diaphragm 230 is preferably elastomeric in construction to provide additional expansion and absorption of the energy of evacuating urine. The diaphragm 230 defines a drain 240 for allowing the patent to release urine collected therein. The drain 240 is an opening at the lowest part of the diaphragm 230 . Release 244 allows the patient to manually open the drain 240 .
[0048] In use, the patient fully engages the tab 212 within the vaginal opening to locate the rim 218 around the urethra. It is envisioned that the tab 212 is held in place due to the pressure from the wall of the vaginal opening and adhesive tension. As a result, when the bladder evacuates through the urethra, the urine passes into the diaphragm 230 . The diaphragm 230 defines a plurality of bellows 236 to allow for expansion as urine collects therein.
[0049] When pressure is applied on the rim 218 , the rim 218 conforms to the periurethral surface. Preferably, an adhesive on the rim 218 swells and becomes sticky to create a periurethral leak-proof seal. As the flange 222 engages the labia minora, the rim 218 is further affixed about the urethra. Preferably, the flange 222 is pressed into place to engage an adhesive thereon. The drain 240 extends away from the patient at the lowest point of the diaphragm 230 . The drain 240 is normally blocked with a one-way valve (not shown) or an end plug 242 which is attached to a release 244 .
[0050] Referring now to FIG. 8, when the device 200 is in place on a patient, the rim 218 surrounds the urethra exit point. As a result, when the bladder evacuates through the urethra, the urine passes into the diaphragm 230 . As the diaphragm 230 collects urine, the plurality of bellows 236 expand downward. Preferably, the diaphragm 230 is constructed of elastomeric material to allow further expansion. When the diaphragm 230 is full of urine, the patient may empty the diaphragm 230 from the drain 240 . Preferably, the drain 240 extends from the low point of the diaphragm 230 to facilitate complete evacuation of the diaphragm 230 . It is envisioned that the patient will empty the device 200 into the toilet. Alternatively, the patient may empty the device 200 into a receptacle for subsequent disposal. To open the drain 240 , the end plug 242 is removed by pulling the release 244 .
[0051] Referring now to FIG. 9, there is disclosed a urine collection system constructed in accordance with the subject disclosure and designated generally by reference numeral 300 . The system 300 includes a securing portion 310 to sealingly engage a patient, a collection portion for storing urine and an irrigation portion for cleansing the vaginal area. In operation, the securing portion 310 engages the patient to capture micturation in a bag 330 of the irrigation portion for subsequent release. The irrigation portion allows the patient to cleanse and medicate the vaginal area of the patient.
[0052] The securing portion 310 includes a tab 312 which serves to secure the system 300 in place. The tab 312 is sized and shaped for insertion into the vaginal opening of the patient. Preferably, the tab 312 is coated with an adhesive to secure the tab 312 within the vaginal opening. The tab 312 does not have a string and is removed by grasping. In another embodiment, a string is fixed on a distal end of the tab 312 to facilitate removal from the vaginal opening.
[0053] The securing portion 310 also includes a rim 318 sized and configured to sealingly engage the periurethral surface of the patient. The rim 318 defines an inlet which surrounds the urethra of the patient. Preferably, the rim 318 is coated with a bio-compatible adhesive appropriate to the corresponding contact area with the patient. The securing portion 310 also includes a flange 322 surrounding the rim 318 . The flange 322 engages the labia minora to help secure the rim 318 in place on the patient. Preferably, the flange 322 is coated with a bio-compatible adhesive to enhance engagement with the patient.
[0054] With continuing reference to FIG. 9, the collection portion includes a syphon portion 340 , shown partially in phantom lines, depending from the rim 318 of the securing portion 310 to collect urine as it evacuates the patient. The syphon portion 340 terminates in a tube for irrigation 342 and a tube for urine collection 344 . In another embodiment, the syphon portion 340 is funnel-shaped. Preferably, the irrigation tube 342 terminates with a one-way check valve 346 to prevent fluid from entering the irrigation tube 342 . A conduit 348 connects to the irrigation tube 342 for delivering topical medical and irrigation solutions. The conduit 348 has a female Luer end 350 to facilitate the introduction of solutions into the conduit 348 through the one-way check valve 346 and into the syphon portion 340 for receiving a cleansing or medicating solution. It is envisioned that the irrigation portion may be adapted for use with each of the urinary incontinence devices disclosed herein. Once in the syphon portion 340 , fluids will wash over the vaginal area within the inlet of the rim 318 .
[0055] The urine collection tube 344 allows the urine and fluid collected in syphon portion 340 to pass into a flexible tube 352 . In another embodiment, the urine collection tube 344 has a leak-proof air vent which allows air into the system 300 but prevents urine from leaking. The flexible tube 352 is reticulated and allows routing in a convenient manner. The flexible tube 352 empties into the bag 330 . The bag 330 has a check valve 354 at its entry to prevent backflow. Alternatively, the urine collection tube 344 may include a pinch valve or squeeze valve to allow bi-directional flow unless manually closed. Such a configuration allows solutions introduced via irrigation portion to be maintained with the syphon portion 340 to more thoroughly wash the vaginal area.
[0056] The bag 330 has straps 356 to fasten to the lower leg of the patient. When full, the patient removes the straps 356 , detaches the bag 330 from the reticulated tube 352 , empties the bag 330 and reattaches the bag 330 to the reticulated tube 352 and restraps the bag 330 on their lower leg. In another embodiment for bedridden patients, the bag 330 mounts on a bed frame or adjacent structure. It is envisioned that when the irrigation tube 342 is used, the cleansing and medicinal solutions are collected in the bag 330 for disposal.
[0057] While the disclosure has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made thereto without departing from the spirit or scope as defined by the appended claims. | A feminine care device for collecting urine including a reservoir defining a recess for receiving urine. The reservoir has a rim and flange configured for periurethral sealing and adhesion to the labia minora, respectively. A tab depends from the reservoir for engagement and adhesion to the anterior vaginal wall. A drain for selectively draining urine from the reservoir is provided. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improvement on the conventional rotating head assembly adapted for use, for example, in a magnetic video recording/reproducing apparatus or the like.
2. Description of the Prior Art
Portable video tape recorders have become popular as a result of efforts to reduce the size of rotating head type magnetic video recording/reproducing device. To meet this tendency, efforts have been exerted also to reduce the size and thickness of the rotating head assemblies to be used for the portable video tape recorders. Such efforts, however, are now approaching a structurally allowable limit.
Further, there have appeared rotating head type magnetic video recording/reproducing apparatuses of the kind having a camera combined therewith. The apparatuses of this kind are more strongly desired to have further reduction in size and weight. Typical examples of the conventional head assemblies used for such video tape recorders and video tape recorders of another type having a camera combined therewith are as described below:
FIG. 1 of the accompanying drawing shows the example of the conventional rotating head assembly, which is of an upper drum rotating system. Referring to FIG. 1, a fixed lower drum 1 has a rotation shaft 2 disposed in the middle part thereof. The rotation shaft 2 is rotatably mounted on the fixed lower drum 1 by means of bearings 3 and 4. A rotating upper drum 5 which is opposed to the fixed lower drum 1 is mounted on a support member 6 by mounting screws 7. The support member 6 is secured to the rotation shaft 2 by a mounting screw 8 and is disposed above the bearing 3. The rotating upper drum 5 is thus arranged to be rotatable relative to the fixed lower drum 1. At least one head base plate 10 which has a magnetic head 9 is mounted on the rotating upper drum 5 by means of screws 11. A travelling face 12 for a magnetic tape is formed on the peripheral faces of the rotating upper drum 5 and the fixed lower drum 1. To the support member 6 is attached a rotating-side winding 13 of a rotary transformer. Meanwhile, a stationary-side winding 14 of the rotary transformer is attached to the fixed lower drum 1 and is opposed to the winding 13. The winding 13 is connected to the magnetic head 9. Incoming or outgoing signals to or from the magnetic head 9 is arranged to go through the electromagnetic coupling of the rotary transformer.
Another support member 15 is mounted on the rotation shaft 2 and is disposed below the bearing 4. A rotary yoke 17 of a motor 16 is mounted on the support member 15 by means of a screw 18. A rotary magnet 19 is secured to the rotary yoke 17. A stator 20 and a stator coil 21 are secured to the fixed lower drum 1 and are opposed to the rotary magnet 19. The fixed lower drum 1 is mounted on a mount 22 which is disposed within a magnetic video recording/reproducing apparatus. The upper part of the rotating head assembly 24 which is arranged in this manner is covered by a cover 25 of the magnetic video recording/reproducing apparatus.
In a magnetic video recording/reproducing apparatus using a rotating head assembly which is arranged as shown in FIG. 1, the rotating upper drum 5 is mounted on the rotation shaft 2 and the rotation shaft is arranged to be carried by the bearings 3 and 4. Such being the arrangement, if the spacing distance between these bearings 3 and 4 is short, the rotation locus of the magnetic head 9 would be greatly affected and would be prevented from making a precise rotation by a tilt of the rotation shaft 2 resulting from deviation of these bearings 3 and 4 from their prescribed relative positions. Because of this problem, it has been extremely difficult to reduce the thickness of the rotating head assembly in the axial direction thereof.
In addition to this problem, the adjustment of the height, angle and protruding extent of the magnetic head 9 relative to the fixed lower drum 1 is difficult. Accordingly, even in cases where some parts must be replaced due to a damage of the magnetic head 9, the work required for this is not limited to mere replacement work on the parts but the height, etc. of the magnetic head 9 must be readjusted. The conventional rotating head assembly thus has been presenting another problem in terms of interchangeability of parts and this has been hindering to improvement in serviceability.
Further, in the case of the assembly shown in FIG. 1, the mounting screw 23 is tightened by inserting a screw driver into a space between the motor 16 and the mount 22. However, the space is too small to facilitate the work. In some cases, the mounting screw is arranged to be tightened from the surface side of the mount 22. In such a case, however, the various mechanisms arranged round the fixed lower drum 1 have worsened the workability.
In the case of a system having a camera combined into one unified body with the rotating head type magnetic video recording/reproducing apparatus, the optical path of the optical system of the camera must be obtained by avoiding the various parts of the rotating head type video recording/reproducing apparatus. This has been hindering attempts to reduce the size of the system. Besides, in such a system, driving means for automatically carrying out a focusing operation by driving an automatic focusing mechanism or driving means for driving a zoom lens to automatically carry out adjustment of a focal point occupies a large space to present a further hindrance to reduction in size.
The rotating head assembly 24 is disposed in the middle part of the magnetic video recording/reproducing apparatus. Besides, on the periphery of the assembly, there are arranged a magnetic tape travel guide, a loading mechanism for pulling the magnetic tape out of a cassette and for placing it on the rotating head assembly 24, etc. Therefore, a cover 25 is generally carried by a peripheral part of the magnetic video recording/reproducing apparatus to keep it away from the rotating head assembly 24. The cover must have a sufficient strength against external pressure which might be applied from outside as indicated by an arrow A. Even if the cover 25 is deformed and bent inward by the external pressure, the cover must be prevented from coming into contact with the rotating head assembly 24. Therefore, in the conventional system of this type, the thickness of the cover 25 is arranged to be thick and the cover is disposed sufficiently away from the rotating head assembly 24. This also has been hindering reduction in size and weight of a magnetic video recording/reproducing apparatus.
FIG. 2 shows an example of the conventional rotating head assembly of a head-on-propeller rotating system. The components similar to those shown in FIG. 1 are indicated by the same reference numerals as those used in FIG. 1. A cylindrical fixed upper drum 26 and a fixed lower drum 1 are fixed in prescribed relative positions by a coupling member 27 and mounting screws 28 and 29. The peripheral faces of the two drums 26 and 1 are arranged to serve as tape travelling surface 12. A guide 30 which guides a magnetic tape (which is not shown) is formed on the peripheral face of the fixed lower drum 1. At the common center of the two drums 1 and 26, there is provided a rotation shaft 2. The rotation shaft 2 is rotatably mounted on the fixed lower drum 1 by means of bearings 3 and 4. A head bar 31 is secured to the rotation shaft 2 by a screw 8. A head plate 32 is fitted on the head bar 31 and is secured thereto. At least one head base plate 10 which has a magnetic head 9 is secured to the head plate 32 by means of mounting screws 11.
In the lower part of the rotation shaft 2, a support member 15 is secured to the rotation shaft 2 in such a manner as to expel the plays of the bearings 3 and 4 in the axial direction of the rotation shaft. With this arrangement, the bearings 3 and 4 have a pre-load imposed thereon. The rotary yoke 15 of a motor 16 is secured to the support member 15 by means of a mounting screw 18. A rotary magnet 19 and a magnet sensor 33 for detecting the position of the magnetic head 9 are mounted on the rotary yoke 15. A stator 20 and a stator coil 21 are secured to the fixed lower drum 1 and are opposed to the rotary magnet 19. A reference numeral 34 indicates a printed circuit board for the motor 19; and 35 indicates a sensor for detecting the phase of the rotary magnet 19. The magnet sensor 33 is arranged not only to detect the position of the magnetic head 9 but also to detect the rotating state of the magnetic head 9 for controlling the normal rotating state of the head 9.
The rotating head assembly of the head-on-propeller rotating system which is arranged as described above with reference to FIG. 2 also has the same shortcomings as the rotating head assembly of the upper-drum rotating system shown in FIG. 1. These shortcomings likewise have been hindering efforts to reduce the size and thickness of the rotating head assembly and, as a result of that, also have been hindering efforts to reduce the size and weight of the magnetic video recording/reproducing apparatus.
In the rotating head assembly described above, the fixed drum 26 and the fixed lower drum 1 are joined together at their peripheral parts by means of the coupling member 27. However, since this arrangement necessitates to tighten the mounting screws 28 and 29 from a lateral direction, the fixed upper drum 26 tends to be deformed by this lateral tightening force. Further, a very high degree of positional precision is required for retaining the two drums 26 and 1 in a prescribed relative positions. However, in the conventionally practiced method of adjusting the relative positions of them, thin washers measuring 5 to 6μ is inserted between the coupling member 27 and the drums 26 and 1 before tightening. Therefore, much time has been required for the adjustment work.
As described in the foregoing with reference to FIGS. 1 and 2, the conventional rotating head assemblies have been hindering the efforts to reduce the size and thickness thereof. As a result of that, reduction in size and weight of an apparatus using such a rotating head assembly has been difficult.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a rotating head assembly which permits reduction in size and thickness thereof. More broadly stated, the invention is directed to reduction in size and weight of a magnetic video recording/reproducing apparatus or the like using a rotating head assembly.
It is another object of the invention to provide a rotating head assembly which facilitates adjustment of the position of the head and has improved interchangeability of parts required at the time of replacing the head.
It is a further object of the invention to provide a rotating head assembly which has excellent workability for mounting it on a mount.
It is another object of the invention to provide a rotating head assembly which permits use of a thin cover member and reduction of spacing distance between the cover member and the rotating head assembly.
It is a further object of the invention to provide a rotating head assembly which includes fixed drums in the upper and lower parts thereof and in which the fixed upper drum is free from the fear of deformation and the relative positions of the fixed upper and lower drums can be adjusted without difficulty.
It is a still further object of the invention to provide a rotating head assembly which permits reduction in size of a magnetic video recording/reproducing system having a camera and a recording/reproducing apparatus arranged into one unified body.
These and other objects, features and advantages of the invention will become apparent from the detailed description of preferred embodiments thereof taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing by way of example a rotating head assembly of the conventional upper drum rotating type.
FIG. 2 is a sectional view showing a rotating head assembly of the conventional head-on-propeller rotating type.
FIG. 3 is a sectional view showing a rotating head assembly as an embodiment of the present invention.
FIG. 4 is a sectional view showing an embodiment of the invention in which the invention is applied to a rotating head assembly of the head-on-propeller rotating type.
FIG. 5 is a sectional view showing a rotating head assembly of the upper drum rotating type embodying the invention and including mounting means for mounting a fixed lower drum 52 on a mount.
FIG. 6 is a sectional view showing a rotating head assembly of the head-on-propeller rotating type as an embodiment of the invention including the above stated mounting means.
FIG. 7 is a sectional view showing a rotating head assembly having the above stated mounting means as an embodiment of the invention in which a bearing serving as supporting means is disposed on a plane perpendicular to the axis of rotation.
FIG. 8(A) is a plan view and FIG. 8(B) a sectional view of a mounting arrangement embodying a feature of the invention.
FIG. 9(A) is a plan view and FIG. 9(B) a sectional view of a fitting arrangement embodying features of the invention.
FIG. 10 is a sectional view showing a rotating head assembly as an embodiment of the invention including fixing means for securing a fixed upper drum to a fixed lower drum.
FIG. 11 is a sectional view of another embodiment of the invention including the above stated fixing means.
FIG. 12 is a sectional view showing still another embodiment of the invention in which the above stated fixing means is arranged to secure a fixed upper drum to both a fixed lower drum and a mount 12.
FIG. 13 is a sectional view showing a further embodiment of the invention in which the above stated fixing means is also arranged to secure a fixed upper drum to both a fixed lower drum and a mount.
FIG. 14 is a sectional view showing an embodiment including a support member arranged to support a cover member.
FIGS. 15 and 16 are sectional views respectively showing other embodiments including the above stated support member.
FIG. 17 is a sectional view showing an embodiment of the invention in which an optical path for an optical system is arranged in the vicinity of the axis of rotation.
FIGS. 18(A) and 18(B) are illustrations respectively showing a rotating head assembly such as the one shown in FIG. 17 in relation to an optical system.
FIGS. 19-23 are sectional views showing other embodiments each providing an optical path for an optical system by arranging the optical path in the vicinity of the axis of rotation.
FIG. 24 is a sectional view showing a still further embodiment of the invention in which there is provided means for driving an optical system within a void hole provided in the vicinity of the axis of rotation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 3 shows a rotating head assembly as an embodiment of the invention. In this case the invention is applied to an upper drum rotating system. A tape travel surface is formed by the peripheral faces of a rotating upper drum 51 and a fixed lower drum 52. A tape guide 53 which is arranged to guide a tape (not shown) is provided on the peripheral face of the fixed lower drum 52. A rotating member support 55 is disposed within the inner space 54 of the fixed lower drum 52. The rotating member support 55 is opposed to a confronting inner circumferential face 56 which is located close to the outer circumferential face of the fixed lower drum 52. Two fixed annular members 57 are disposed on this inner circumferential face 56. Meanwhile, on the outer circumferential face 58 of the rotating member support 55 which is opposed to the inner circumferential face 56, there are disposed two rotating annular members 59. Annular groove parts 60 and 61 are respectively provided in the fixed annular member 57 and the rotating annular member 59. A plurality of steel balls 62 are inserted in between the two annular groove parts 60 and 61. The fixed annular member 57, the rotating annular member 59 and the steel balls 62 jointly form two rolling bearings 63. The rotating member support 55 is carried by these two rolling bearings 63 in such a way as to be rotatable relative to the fixed lower drum 52. The two rolling bearings 63 are spaced by a spacer 64 and are fixed in place with tightening rings 65 and 66 screwed to the rotating member support 55 and the fixed lower drum 52. A head base plate 68 which has a magnetic head 67 is mounted on the rotating upper drum 51 by means of mounting screws 69. The height of the magnetic head 67 is arranged to be adjustable by height adjustment screws 70. The position of the magnetic head 67 is arranged to be detected by a magnetic sensor 71. A detection coil 72 is arranged to detect the approach of the magnetic sensor 71. A sensor 73 is provided for detecting the phase of a rotary magnet 74. When power is supplied to a stator coil 75 from a driving circuit which is not shown, a rotating force acts on the rotary magnet 74 to cause the rotating member support 55 to rotate in a state of being carried by the rolling bearings 63. A magnetic tape which is not shown is wound round the peripheral faces of the rotating upper drum 51 and the fixed lower drum 52 and is arranged to travel there. With the magnetic tape caused to travel, the magnetic head 67 rotates at a speed higher than the travelling speed of the magnetic tape to thus perform scanning over the magnetic surface of the magnetic tape. Then, a magnetic video recording/reproducing apparatus which is not shown performs a recording or reproducing operation. During the operation, each signal to be given or received between the magnetic head 67 and the magnetic tape comes from or goes out to a signal processing circuit of the magnetic video recording/reproducing apparatus through the rotating-side winding 76 and the stationary-side winding 77 of the rotary transformer.
The diameter of the rolling bearings 63 is large enough to allow other components of the rotating head assembly to be arranged in the vicinity of the axis of rotation of the bearings 63. The rotary magnet 74 is attached to the rotating member support 55 within the inner space 78 of the rotating member support 55. The stator coil 75 and a stator 79 are attached to a protruding part 81 of a support member 80. The stationary-side winding 77 of the rotary transformer is secured to the upper end face of a gap adjustment member 82 which is screwed into the protruding part 81. The rotating-side winding 76 is attached to the rotating member support 55 and is disposed opposite to the stationary-side winding 77. The gap between the windings 77 and 76 is adjustable by adjusting the screwing degree of the gap adjustment member 82.
The components to be arranged in the vicinity of the axis of rotation of the bearings 63 include positioning arrangement for determining the mounting position of the rotating upper drum 51 relative to the rotating member support 55. The positioning arrangement is as follows: As shown in FIG. 3, the rotating upper drum 51 is provided with a square fitting recess 83 extending from the lower side thereof while the rotating member support 55 is provided with a square fitting protrusion 84. The fitting recess 83 is fitted on the fitting protrusion. Then, a mounting screw 85 is screwed into holes provided in the rotating upper drum 51 and the rotating member support 55 to set the rotating upper drum 51 into a prescribed position. In the embodiment shown in FIG. 3, the precision of the relative positions of the rotating upper drum 51 and the fixed lower drum 52 is highly improved because of the arrangement to mount the rotating upper drum 51 accurately in a prescribed mounting position thereof by fitting the fitting recessed part 83 onto the fitting protrudent part 84 of the rotating member support 55. Such being the arrangement, before the rotating upper drum 51 is mounted on the rotating member support 55, the rotating upper drum 51 is first fitted on an adjustment tool (not shown) which is prepared into the same shape as the rotating member support 55. Then, the head base plate 68 is attached to the rotating upper drum 51 while adjusting the height, angle and protruding extent of the magnetic head 67 to the position of the fixed lower drum which is indicated by the adjustment tool. This enables to precisely bring the magnetic head 67 into alignment with the fixed lower drum 52. This arrangement not only enhances the interchangeability of parts but also improves serviceability because any rotating upper drum 51 can be used as long as it has undergone such adjustment. More specifically stated, part replacement work required as a result of some damage of the magnetic head 67 or the like can be accomplished by merely replacing the rotating upper drum 51. This arrangement is, therefore, advantageous for reduction in cost.
Further, with regard to rotating precision, the large diameter of the rolling bearings 63 resulting from the location thereof close to the periphery of the fixed lower drum 52 serves to minimize the adverse effects of deviation of the relative positions of the rolling bearings 63 or tilting thereof on the locus of rotation of the magnetic head 67. Accordingly, distance between the rolling bearings 63 can be shortened for reduction in thickness. Further, the rotating precision of the rotating upper drum 51 is determined by the rotating precision of the rolling bearings 63 and the rotating member support 55 as well as that of the rotating upper drum 51. Therefore, compared with the conventional arrangement, the rotating precision of the rotating upper drum 51 can be increased with the number of parts that require a high degree of precision decreased.
FIG. 4 shows another embodiment in which the invention is applied to a rotating head assembly of the head-on-propeller rotating type. The parts indicated in FIG. 3 by the same reference numerals are identical with the corresponding parts shown in FIG. 3. Therefore, description of such parts is omitted here. A fixed upper drum 86 is secured to a fixed lower drum 52 through a coupling member 87 and mounting screws 88 and 89 in such a way as to keep a prescribed positional relation to the fixed lower drum 52. The relative positions of the fixed upper and lower drums 86 and 52 is adjusted by inserting a thin washer or the like in between the coupling member 87 and the fixed upper or lower drum 86 or 52.
A head bar 90 on which a head base plate 68 is mounted is mounted on a rotating member support 55 at a prescribed position by fitting its fitting recessed part 91 onto a fitting protrudent part 84 and then by tightening a mounting screw 85.
The operation and the advantageous effects of the embodiment shown in FIG. 4 is almost the same as those of the embodiment shown in FIG. 3.
The following description covers the embodiments of the invention including components which are disposed within a space available in the vicinity of the axis of rotation of the bearing 63 to give an advantageous effect.
FIG. 5 shows an embodiment in which the invention is applied to a rotating head assembly of the upper drum rotating type. In this case, means for securing a fixed lower drum 52 to a mount is disposed in the space available in the vicinity of the above stated rotation axis. The parts identical with the corresponding parts shown in FIG. 3 is indicated by the same reference numerals in FIG. 5. A support part 92 which is formed into one unified body with a rotating upper drum 51 is disposed within the inner space 54 of a fixed lower drum 52. A fixed lower drum 52 is provided with an inner circumferential face 56 which is opposed to the support part 92. Two fixed annular members 57 are disposed on this inner circumferential face 56 of the fixed lower drum 52 and is opposed to the support part 92 close to the peripheral face of the support part.
Rolling bearings 63 are formed as shown in FIG. 5 jointly by the annular members 57, annular groove parts 60 and 61 and steel balls 62. The plays of the rolling bearings 63 in the radial and axial directions thereof are removed by biasing the steel balls towards one side within the annular groove parts.
A fixed member 95 is secured to the fixed lower drum 52 by mounting screws 94. The fixed member 95 has a stator coil 75 secured thereto. A rotary magnet 74 which is secured to a mounting member 96 is attached to the support part 92 by means of screws 97.
The fixed member 95 is provided with a downward recessed part 98 which has a fitting hole 99 in the middle part thereof. Meanwhile, a pin 101 is formed on a mount 100. The pin 101 is fitted into the fitting hole 99 of the fixed member 95. The whole rotating head assembly is mounted on the mount 100 by tightening a mounting screw 103 through a void hole 102 which is provided in the middle part of the rotating upper drum 51. In accordance with this embodiment, the large diameter of the rolling bearings 63 permits provision of the void hole 102 in the middle part of the rotating upper drum 23, which greatly facilitates the tightening work on the mounting screw 103. This contributes to improvement in workability. Compared with the conventional arrangement shown in FIG. 1, use of only one mounting screw 103 suffices in this case and this further contributes to improvement in workability.
Another embodiment shown in FIG. 6 is a rotating head assembly of the head-on-propeller rotating type, in which means for securing a fixed lower drum 52 to a mount 100 is arranged in a space available in the vicinity of the axis of rotation mentioned in the foregoing. In FIG. 6, the parts of the embodiment which are identical with the corresponding parts shown in FIGS. 4 and 5 are indicated by the same reference numerals as FIGS. 4 and 5. A rotating member 104 and a fixed upper drum 86 are respectively provided with void holes 106 and 107 which are located in the neighborhood of the above stated axis of rotation. A mounting screw 103 is arranged to be tightened through these void holes 106 and 107.
FIG. 7 shows a further embodiment of the invention as another variation of the type having means for securing a fixed lower drum 52 to a mount 100 within a space provided in the vicinity of the above stated axis of rotation. In FIG. 7, the same components as those shown in FIG. 5 are indicated by the same reference numerals. The lower side 107 of a rotating upper drum 51 and the upper side 108 of a fixed lower drum 52 are respectively provided with annular groove parts 109 and 110. A plurality of steel balls 62 are inserted in between these annular groove parts 109 and 110. The two groove parts and the steel balls jointly form a rolling bearing 63. On the opposed sides of the fixed lower drum 52 and the rotating upper drum 51 are mounted a stationary-side winding 76 and a rotating-side winding of a signal transmitting rotary transformer, a stator coil 75 of a motor, a rotary magnet 75, a pre-load magnet 112 for carrying the rotating upper drum 51 and adjusting a pre-load imposed on the rolling bearing 63, and a pre-load adjustment screw 111. A head base plate 68 which has a magnetic head 67 is mounted on the rotating upper drum 51 by means of mounting screws 69. An attractive force between the pre-load magnet 112 and the pre-load adjustment screw 111 is adjustable by adjusting the screwing degree of the screw 111. With this arrangement, the state of carrying the rotating upper drum 51 and the pre-load imposed on the steel balls 62 of the rolling bearing 63 are adjusted in a non-contact manner.
In this embodiment, the rolling bearing 63 is arranged on a plane perpendicular to the axis of rotation of the rotating upper drum 51 and is positioned close to the peripheral faces of the two drums 51 and 52. This arrangement permits reduction in thickness to a great extent. The rotational precision of the rotating upper drum 51 is determined only by rolling bearing 63 in addition to the rotating precision of the rotating upper drum 51. The embodiment therefore permits reduction in the number of parts that requires a high degree of precision and enables to enhance the rotational precision with a less number of parts and at a low cost. In addition to this advantage, the embodiment gives improved workability for mounting the assembly on a mount 100 in the same manner as in the cases of the preceding embodiments shown in FIGS. 5 and 6.
The mounting angle of the whole rotating head assembly to the mount 100 in the circumferential direction is determined by relation to the tape travel surface of the assembly. In view of this, it is preferable to have a fitting hole 99 and a pin 101 arranged in such a manner that the above stated mounting angle in the circumferential direction is automatically determined when they come into fitting engagement. An example of such fitting arrangement is as shown in FIG. 8. In this case, the pin 101 is provided with a projection 101a on one side thereof while the fitting hole 99 is provided with a sidewise extending hole part 99a which is formed in a position to correspond to the projection 101a. When the fitting hole 99 is fitted on the pin 101, the mounting angle in the circumferential direction of the rotating head assembly to the mount 100 is automatically determined. In FIG. 8, a reference numeral 113 indicates a washer.
Another example of the fitting arrangement of the fitting hole 99 and the pin 101 is as shown in FIG. 9. In this case, the mount 100 is provided with another pin 101b which is arranged in a position away from the pin 101 for the purpose of positioning. The recessed part 98 of a fixed member on the other hand is provided with a slot 99b which is arranged separately from the fitting hole 99. The positioning pin 101b comes into fitting engagement with the slot 99b when the fitting hole 99 is fitted on the pin 101. This automatically determines the mounting angle of the rotating head assembly to the mount 100. With the rotating head assembly thus mounted, a mounting screw 103 is tightened through a washer 113.
FIG. 10 shows a rotating head assembly of the head-on-propeller rotating type as another embodiment of the invention, in which means for securing a fixed upper drum 86 to a fixed lower drum 52 is disposed in a space provided in the vicinity of the above stated axis of rotation. In FIG. 10, the same components as those shown in FIGS. 4 or 6 are indicated by the same reference numerals. A support member 95 is provided with a protrudent part 113 which is disposed in the central part of the fixed lower drum 52. The fixed upper drum 86 is provided with a cylindrical connection part 114 formed in the central part thereof. The connection part 114 pierces through a hole 115 provided in the central part of a rotating member 104 around the rotation axis thereof and thus comes into contact with the protrudent part 113. The connection part 114 is thus secured to the protrudent part 113 by a mounting screw 116. There are provided two rolling bearings 63 which are spaced by means of a spacer 121 and are fixed in their positions by a washer 119, mounting screws 120 and a tightening ring 93.
A square fitting recessed part 117 is provided on the upper side of the protrudent part 113 of the support member 95. Meanwhile, a square fitting protrudent part 118 is provided on the lower side of the connecting part 114 of the fixed upper drum 86. The protrudent part 118 is arranged to be fitted into the recessed part 117. The fixed upper drum 86 is secured to the support member 95 in such a way as to keep the upper and lower fixed drums 86 and 52 in a predetermined relative positions with the protrudent part 118 fitted into the recessed part 117 and with the mounting screw 116 tightened.
In this embodiment, the connection part 114 and the protrudent part 113 are disposed in the middle parts of the fixed upper and lower drums 86 and 52 with no rotation shaft provided in the middle parts. The two parts 113 and 114 are connected to each other by tightening the mounting screw 116 in the axial direction thereof. This arrangement dispenses with the coupling member 87 which is shown in FIG. 4 and eliminates the possibility of deformation of the fixed upper drum 86. The relative positions of the upper and lower fixed drums 86 and 52 are adjusted by pushing the peripheral face of the fixed upper drum against a reference plane and then by tightening the mounting screw 116 or in some other suitable manner. Therefore, the adjustment can be accomplished very simply.
FIG. 11 shows a further embodiment which also includes means for securing a fixed upper drum 86 to a fixed lower drum 52 with the means arranged in the vicinity of the above stated axis of rotation in a manner similar to the preceding embodiment shown in FIG. 10. The same components of the embodiment are indicated by the same reference numerals as FIG. 10. A rotating member 104 is disposed within the inner spaces 54 and 54' of upper and lower fixed drums 86 and 52. Annular groove parts 60 and 60' are respectively formed in the inner circumferential faces 56 and 56' of the upper and lower fixed drums 86 and 52 and are located close to their peripheral faces. Meanwhile, there are provided rotating annular members 59 and 59' on the rotating member 104. These rotating annular members 59 and 59' are provided with annular groove parts 61 and 61' which are formed opposite to the annular groove parts 60 and 60'. A plurality of steel balls 62 and 62' are inserted respectively in between the opposed annular groove parts 60 and 61 and between the other opposed annular groove parts 60' and 61'. A rolling bearing 63 is formed jointly by the annular groove parts 60 and 61 and the steel balls 62 while another rolling bearing 63' is formed by the opposed annular groove parts 60' and 61' and the steel balls 62'. These rolling bearings 63 and 63' rotatably carry the rotating member 104 on the fixed lower drum 52.
The advantageous effects attainable by the embodiment shown in FIG. 11 are about the same as the effects attainable by the embodiment shown in FIG. 10.
FIG. 12 shows also a rotating head assembly of the head-on-propeller rotating type as a further embodiment of the invention. In this case, the embodiment includes means for securing a fixed upper drum 86 not only to a fixed lower drum 52 but also to a mount 100 with the securing means arranged in the vicinity of the aforementioned axis of rotation. The components of this embodiment that are the same as those shown in FIGS. 4, 6 and 10 are indicated by the same reference numerals. A support member 80 has a protrudent part 121 which is disposed in the middle part of a fixed lower drum 52. The protrudent part 121 is provided with a circular or square fitting hole 124. A connection part 122 is provided in the middle part of the fixed upper drum 86. The connection part 122 is arranged to pierce through a hole 115 provided in the middle part of a rotating member 104. The connection part 122 is provided with a stepped part 123. The portion of the connection part 122 from the stepped part 123 to the fore end thereof is formed into a circular or square shaped fitting part 125, which is fitted into the above stated fitting hole 124. In the middle part of the connection part 122, there is formed a recess 126 with a screw hole 127 provided therein. With the fitting part 125 fitted into the fitting hole 124, the upper and lower fixed drums 52 and 86 are secured to each other with a mounting screw 128 screwed through the screw hole 127 into a mount 100. The two drums are thus simultaneously secured to the mount 100. The mount 100 has a fitting hole 129 which is provided with a member, which is not shown but is arranged to determine the mounting angle of the assembly relative to the mount 100 in the circumferential direction thereof. The mounting angle in the circumferential direction of the fixed lower drum 52 is automatically determined with the support member 80 fitted into the fitting hole 129. In this embodiment shown in FIG. 12, the connection part 122 and the protrudent part 121 are disposed in the middle parts of the upper and lower fixed drums 86 and 52 with no rotation shaft provided there. The two drums and the mount 100 are connected to each other by the mounting screw 128 in the middle part of the assembly. This arrangement thus dispenses with the coupling member 87 shown in FIG. 4 to preclude any possibility of deformation of the fixed upper drum 86. Besides, the relative positions of the fixed upper drum and the support member 80 are determined by the fitting engagement of the fitting part 125 and the fitting hole 124. Therefore, the relative positions of the upper and lower fixed drums 86 and 52 are adjusted through the adjustment of the positions of the fixed lower drum 52 and the support member 80. This adjustment can be very simply accomplished in such a manner as to push the peripheral face of the fixed lower drum 52 against a reference plane which is not shown and then to tighten a mounting screw 94. Further, the provision of the fitting part 125 and the fitting hole 124 makes it possible that, when the fixed upper drum 86 is removed for replacing the magnetic head 67, it may be again mounted without readjustment of the relative positions of the upper and lower fixed drums 86 and 52. Since the mounting screw 128 is positioned in the middle part, a screw driver can be inserted without any obstacle, so that the tightening work thereon can be greatly facilitated.
The fitting hole 129 of the mount 100 is provided with a member (not shown) that is arranged to determine the mounting angle in the circumferential direction as mentioned above. The mounting angle of the fixed lower drum 52 relative to the mount 100 therefore can be automatically determined. Further, in cases where the mounting screw 128 loosens, the arrangement of the embodiment prevents deviation of the fixed lower drum from the position and the mounting angle thereof in the circumferential direction.
The arrangement to simultaneously mount the upper and lower fixed drums 86 and 52 onto the mount 100 with the mounting screw 128 greatly simplifies mounting work and permits reduction in the number of parts and cost.
FIG. 13 shows another structural arrangement of a rotating head assembly embodying the invention. In this embodiment, different means from that of the preceding embodiment is used for securing the upper and lower fixed drums 86 and 52 to the mount 100 simultaneously with securing the upper drum 86 to the lower drum 52. In FIG. 13, the same components as those shown in FIGS. 7 and 12 are indicated by the same reference numerals as those used in these figures.
This embodiment includes fitting holes 127 and 130 which are respectively provided in the upper and lower fixed drums 86 and 52 for receiving a mounting screw 128. There is provided a rotating member 104 which is opposed to the fixed lower drum 52 on a plane perpendicular to the axis of rotation. This embodiment also gives about the same advantageous effects as the embodiment shown in FIG. 12.
FIG. 14 shows a rotating head assembly of the upper drum rotating type embodying the invention as another example. In this embodiment, a holding member is provided for holding a cover member for covering the rotating head assembly and the cover holding member is disposed in a space available in the vicinity of the aforementioned axis of rotation. In FIG. 14, the like components are also indicated by like reference numerals as in other drawings. In this case, mounting on the mount 100 is effected with a plurality of mounting screws 130. A rotating upper drum 51 and a fixed member 95 are respectively provided with void holes 131 and 132 which are located in the middle parts of them. The holding member or post 133 is disposed through the holes 131 and 132. The holding member 133 has its lower end secured to the mount 100 and its upper end extended upward from the upper side of the rotating upper drum 51 to come into contact with the cover 134. In accordance with the embodiment shown in FIG. 14, the provision of the holes 131 and 132 permits the holding member 133 to be disposed there. When an external force is applied to the cover 134 as shown with an arrow A in the middle of the drawing to deform the cover 134, the holding member 133 holds the cover and prevents it from coming into contact with the rotating upper drum 51. The provision of the holding member, therefore, permits reduction in distance between the cover 134 and the rotating head assembly. Therefore, this permits reduction in thickness of the material of the cover 134.
FIG. 15 shows an embodiment of the head-on-propeller rotating type which is also provided with the above stated holding member. FIG. 15 shows the same components with the same reference numerals as in FIG. 14. A fixed upper drum 86 and a rotating member 104 are provided with holes 135 and 136 which are disposed in the middle parts of them. A fixed member 137 has a protrudent part 137 which is inserted into the lower half portion of the hole 136 of the rotating member 104. A stator coil 75 of a face-opposed type motor is attached to this protrudent part 137. The fixed member 95 is mounted on the mount 100 by means of a screw 138. The cover 134 and the holding member 134' are formed into one unified body with each other. The holding member 134' is disposed within the holes 135 and 136. The lower end of the holding member 134' is located slightly above the upper end face of the protrudent part 137. This embodiment also gives the same advantageous effects as those obtainable from the embodiment shown in FIG. 14.
FIG. 16 shows another embodiment as a variation of the preceding embodiment also having a holding member similar to the one used in the preceding embodiment. In this case, a bearing 63 is arranged on a plane perpendicular to the axis of rotation.
FIG. 17 shows another rotating head assembly of the upper drum rotating type embodying the invention. In this embodiment, the void hole available in the vicinity of the axis of rotation is utilized for providing an optical path for an optical system. In FIG. 17, the reference numerals used in FIG. 14 are used to indicate like components. A void hole 131 is provided at the center of rotation of a rotating upper drum 51. Another void hole 132 which communicates with the void hole 131 is provided in a fixed member 95. A photo taking optical system 139 and a lens barrel 140 which carries the optical system 139 are disposed above the void hole 131 and are opposed thereto. The void holes 131 and 132 form the optical path of the optical system 139. Meanwhile, a solid image pickup element 141 such as CCD or BBD which is positioned on an imaging plane is secured to a mount 95. A shield member 142 which serves combined functions as a shield case for a stator coil 75 and a rotary magnet 74 and a light shielding mask for the optical system 139 is secured to the fixed member 95. An optical image incident from the optical system 139 is converted into an electrical signal by the solid image pickup element 141. The electrical signal is processed through a signal processing circuit which is not shown and then comes to a magnetic head 67 through the stationary-side winding 77 and the rotating-side winding 76 of a rotary transformer to be recorded on a magnetic head.
In the case of the embodiment shown in FIG. 17, the void holes 131 and 132 are provided respectively in the rotating upper drum 51 and the fixed lower drum 51 and these holes 131 and 132 are utilized as the optical path of the optical system. This arrangement is advantageous particularly for reduction in size of a system where a camera and a magnetic video recording/reproducing apparatus are combined into one unit. The relation of the rotating head assembly to the optical system in a system such as shown in FIG. 17 is as shown in FIG. 18.
In the case of FIG. 18(A), the optical path formed in the rotating head assembly 142 is used for a photo taking optical system and is indicated by reference numeral 143. The body of the system consists of a magnetic recording/reproducing apparatus and a camera which are combined into one unit. An optical image passes through the photo taking optical system 145 and then comes through a half mirror 146 and a photo taking optical path 143 to image on a solid image pickup element 141. Meanwhile, a part of the light is reflected at the half mirror 146. The reflected light comes to an eye of the photographer through a mirror 147 and a view finder optical system 148. FIG. 18(B) shows another case in which the optical path formed in the rotating head assembly 142 is used for a view finder optical system and is indicated by reference numeral 150.
FIG. 19 shows a rotating head assembly of the head-on-propell rotating type as another embodiment of the invention. In this embodiment, a void hole provided in the vicinity of the axis of rotation is used as the optical path of an optical system. In FIG. 19, the same reference numerals as those used in FIGS. 15 and 17 indicate like components. A void holes 151 and 152 are formed in the middle parts of a fixed upper drum 86 and a rotating member 104. A protrudent part 137 which is formed on a fixed member 95 is positioned in the lower half portion of the void hole 152. A solid image pickup element 141 is secured to this protrudent part 137. A lens barrel 140 which carries either a photo taking optical system 139 or a view finder optical system is secured to a recessed parts of the void holes 151 and 152.
FIG. 20 shows another embodiment of the invention in which a photo taking optical system 139 is carried by a support member 153 which is provided on a rotating upper drum 51.
FIG. 21 shows a further embodiment of the invention in which a stator coil 75 is secured to a lens barrel 140 while a rotary magnet 74 is secured to a rotating upper drum 51 and is opposed to the stator coil 75. A reference numeral 154 indicates a shield member arranged to serve combined functions as a shield member and a light shielding member; 155 indicates a support member; and 156 indicates a photo taking optical system.
FIG. 22 shows a further embodiment of the invention in which the stationary-side winding 77 and the rotating-side winding 76 are respectively attached to a lens barrel 140 and a rotating upper drum 51.
FIG. 23 shows another embodiment of the invention in which the above-mentioned optical path is arranged in a rotating head assembly having a rolling bearing 63 provided on a plane perpendicular to the axis of rotation.
In FIGS. 20-23, the same reference numerals as those used in FIGS. 14-17 indicate like components.
The embodiments shown in FIGS. 19-23 give about the same advantageous effects as the embodiment shown in FIG. 17.
FIG. 24 shows a still further embodiment in which means for driving an optical system is disposed within the void hole mentioned in the foregoing.
Automatic focusing mechanisms for automatically focusing on an object to be photographed have begun to be employed in cameras. Recently, these automatic focusing mechanisms come to include TTL automatic focusing mechanisms which are arranged to branch an optical path from a photo taking optical system through a half mirror or the like; to supply the light of the branched optical path to a photo-electric conversion element; and then to perform focus adjustment in accordance with the output of this photo-electric conversion element. In such a TTL automatic focusing mechanism, with the optical system arranged in the manner as mentioned above, the focusing adjustment is accomplished by moving a lens of the photo taking optical system immediately before or close to an imaging plane. In the case of the embodiment shown in FIG. 24, the non-existence of any rotating shaft permits to arrange a photo taking optical system and an automatic focusing mechanism in the void holes 131 and 132. More specifically, a portion of a fixed lens barrel 140 carrying a fixed lens 139 of the photo taking optical system is disposed within the void hole 131. Meanwhile, a movable lens barrel 158 which is in screwed engagement with the threaded part 157 of the fixed lens barrel 140 is located also within the void hole 131. The movable lens barrel 158 carries the automatic focusing lens 156 of the photo taking optical system. A magnet 159 and a coil 160 are secured to the movable lens barrel 158 and to a fixed member 95 and are thus arranged to serve as means for driving the automatic focusing lens 156 in the direction of the optical axis of the optical system.
A solid image pickup element 141 such as CCD or BBD which is located at the imaging plane of the photo taking optical system 139 and 156 is secured to a mount 48. A half mirror 162 supplies a portion of the light of the photo taking optical path 161 to a photo-electric conversion element 163. The photo-electric conversion element 163 and the solid image pickup element 141 are arranged in optically equivalent positions. Therefore, when an optical image is out of focus at the photo-electric conversion element 163, it is also out of focus at the solid image pickup element 141.
When a portion of the light of the photo taking optical path 161 is supplied through the half mirror to the photo-electric conversion element 163, the light thus supplied is converted into an electrical signal by the photo-electric conversion element 163. The degree of out-of-focus of the optical image is determined by an automatic focusing circuit (not shown) through the output of the photo-electric conversion element 163. The circuit then causes an exciting current of a magnitude corresponding to the determined out-of-focus degree to the coil 160. With the current supplied, the magnet 159 and the movable lens barrel 158 rotate. Then, the threaded part 157 guides the movable lens barrel 158 and the automatic focusing lens 156 to allow them to move together in the direction of the optical axis. When the lens come to an in-focus position, the exciting current of the stator coil 160 becomes zero to set the automatic focusing lens 156 in that position.
The light which comes to the solid image pickup element 141 through the photo taking optical system 139 and 156 and the half mirror 162 is converted into an electrical signal. The signal comes to a signal processing circuit which is not shown and, after that, comes through the stationary-side winding 77 and rotating-side winding 76 of a rotary transformer to a magnetic head 67 to be recorded on a magnetic tape.
In the embodiment shown in FIG. 24, the parts of an automatic focusing mechanism including the photo taking optical system 139 and 156, the moving lens barrel 158, the magnet 159, the coil 160, the half mirror 162, the photo-electric conversion element 163, etc. and the solid image pickup element 141 can be arranged within the void hole 131 of the rotating upper drum 51 and the void hole 132 of the fixed member 95. This arrangement of the embodiment, therefore, advantageously contributes to reduction in size of a system in which a camera having an automatic focusing mechanism and a magnetic video recording/reproducing apparatus are arranged into one unified body.
As will be apparent from the foregoing description of embodiments, the invention enables to obtain a rotating head assembly which is not only compact but excels in workability and operability. | A rotating head assembly comprises a fixed lower drum; a rotating member which has at least one head and also has a void hole in a position corresponding to the axis of rotation; supporting means which is disposed in a position farther away from the axis of rotation than the void hole and is arranged to support the rotating member rotatably relative to the fixed lower drum; and at least one composing means which is arranged by utilizing the void hole to compose at least a portion of the rotating head assembly. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to and the benefit of the filing of U.S. Provisional Patent Application Ser. No. 61/388,468, entitled “High Efficiency Slug Containing Vapor Recovery”, filed on Sep. 30, 2010, and the specification thereof is incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
Technical Field
Embodiments of the present invention provide a vapor recovery system for a hydrocarbon well. Particularly, embodiments of the present invention a vapor recovery system which is capable of handling large slugs of liquids without inducing large recycle loops thereby permitting the use of a relatively small compressor
BRIEF SUMMARY OF EMBODIMENTS OF THE PRESENT INVENTION
An embodiment of the present invention relates to a slug-containing vapor recovery system having a first flow of hydrocarbon vapors in fluid communication with a first pressure sensor, the hydrocarbon vapors traveling to an inlet scrubber; allowing a flow of liquid hydrocarbons to flow from a flash separator and be heated into a vapor before joining the first flow of hydrocarbon vapors; and reducing the flow of liquid hydrocarbons from the flash separator when the first pressure sensor senses a pressure in excess of a predetermined amount. Optionally, reducing the flow of liquid hydrocarbons can include stopping the flow of liquid hydrocarbons from the flash separator. Heating the flow of liquid hydrocarbons into a vapor can include heating the flow of liquid hydrocarbons with a heat exchanger.
In one embodiment, the heat exchanger is disposed within a two-phase stabilizing reboiler, and the stabilizing reboiler can be heated by a firetube. The system can also include providing a two-phase, slug-containing flash separator, which itself can have a gas expansion vessel communicably coupled to it. The gas expansion vessel can be in fluid communication with a well-stream inlet separator. The gas expansion vessel can allow the pressure of contents therein to increase due to the arrival of a slug of liquid hydrocarbons.
An embodiment of the present invention also relates to a slug-containing vapor recovery system having a gas expansion vessel communicably coupled to receive an incoming flow of hydrocarbons from a well-stream inlet, a two-phase, slug-containing flash separator in fluid communication with the gas expansion vessel, a first pressure sensor sensing a pressure of contents of the gas expansion vessel, and operating a compressor which compresses hydrocarbon vapors, the compressor operating at a first speed when pressure sensed by the first pressure sensor is less than a first predetermined amount and the compressor operating at a second speed when pressure sensed by the first pressure sensor is greater than the first predetermined amount, the first speed being less than the second speed.
The system can divert the incoming flow of hydrocarbons to bypass at least a portion of the system when the first pressure sensor senses a pressure which is greater than a second predetermined amount. The system can optionally divert the incoming flow of hydrocarbons such that they travel from the existing well-stream inlet separator into a hydrocarbon storage tank.
Optionally, the system can also include: providing a second pressure sensor in fluid communication with a first flow of hydrocarbon vapors traveling to an inlet scrubber; allowing a flow of liquid hydrocarbons to flow from a flash separator and be heated into a vapor before joining the first flow of hydrocarbon vapors; and/or reducing the flow of liquid hydrocarbons from the flash separator when the first pressure sensor senses a pressure in excess of a predetermined amount. The gas expansion vessel can include a liquid level switch. The incoming flow of hydrocarbons can be diverted around at least a portion of the system in response to the detection of a liquid by the liquid level switch. Optionally, the incoming flow of hydrocarbons can be diverted around at least a portion of the system for a predetermined amount of time, which can optionally include diverting the incoming flow of hydrocarbons into a hydrocarbon storage tank, which itself can optionally have a volume of at least 200 barrels.
An embodiment of the present invention also relates to a slug-containing vapor recovery apparatus having a first hydrocarbon vapors passageway, the passageway in fluid communication with a first pressure sensor, the first hydrocarbon vapors passageway communicable with an inlet scrubber, a liquid hydrocarbon vaporizing heater, the vaporizing heater communicably coupled to a condensate outlet of a flash separator and the vaporizing heater communicably coupled to the first hydrocarbon vapors passageway, and an apparatus capable of reducing a flow of liquid hydrocarbons from the flash separator when the first pressure sensor senses a pressure in excess of a first predetermined amount.
Optionally, a diverting valve can be activated in response to the first pressure sensor sensing a pressure which is in excess of a second predetermined amount. In one embodiment, the diverting valve can be communicably coupleable to an outlet of a hydrocarbon producing well and to an inlet of a hydrocarbon storage tank.
An embodiment of the present invention also relates to a slug-containing vapor recovery apparatus having a gas expansion vessel communicably coupleable to an outlet of a hydrocarbon-producing well, a two-phase slug-containing flash separator in fluid communication with the gas expansion vessel, a first pressure sensor, the first pressure sensor positioned to sense a pressure of contents of the gas expansion vessel, and an at least two speed compressor, the compressor communicably coupled to an outlet of a first stage inlet scrubber, the compressor selectively speed controlled based on an output of the first pressure sensor. The compressor can be caused to operate at a speed which is faster when the pressure sensor detects a pressure that is in excess of a predetermined amount, as compared with the speed of the compressor when the sensor detects a pressure that is below the predetermined amount. Optionally, the apparatus can also include a liquid level switch positioned to detect a liquid level within the gas expansion vessel.
In one embodiment, a diverting valve can be activated in response to a sensed liquid level by the liquid level switch. The diverting valve can be communicably coupleable to an outlet of a hydrocarbon producing well and to an inlet of a hydrocarbon storage tank.
An embodiment of the present invention also relates to a slug-containing vapor recovery apparatus having a compressor, a reboiler, and a gas expansion vessel, the gas expansion vessel allowing the pressure of a hydrocarbon gas to increase upon receipt of an incoming hydrocarbon slug, thereby increasing a gas storage capacity of the gas expansion vessel, the vapor recovery apparatus configured such that if the pressure of the gas in the gas expansion vessel reaches a predetermined set point a pressure control process of the vapor recovery apparatus causes the dumping of liquid hydrocarbons into the reboiler to cease, thus allowing the additional capacity of the compressor to be applied to reducing the pressure of the gas in the gas expansion vessel.
Objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, 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.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more preferred embodiments of the invention and are not to be construed as limiting the invention. In the drawings:
FIGS. 1A-D (hereinafter referred to as “FIG. 1 ”) illustrate a schematic diagram of an embodiment of the present invention in use with a 2-stage compressor; and
FIGS. 2A-D (hereinafter referred to as “FIG. 2 ”) illustrate a schematic diagram of an embodiment of the present invention in use with a 3-stage compressor.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention relates to a high efficiency slug containing vapor recovery system. Referring now to FIG. 1 , a flow diagram for a two-stage compressor embodiment of the present invention is illustrated. The system of the present invention can optionally be powered by an internal combustion engine an electric motor, other power means or a combination thereof. Although the components of the present invention can be selected so as to handle virtually any pressure, in one embodiment, the system is constructed to handle a maximum discharge pressure of about 400 psig. For applications requiring higher discharge pressures, a compressor with three or more stages can be used and will produce desirable results. Because of higher discharge pressures, the amount of heat generated by three stages or more of compression will be greater than the amount of heat generated by a two stages of compression. On some high pressure applications, atmospheric cooling can optionally be used to cool parts of the process, particularly those which generate very high temperatures. For embodiments of the present invention which are used with several stages of compression, additional compression temperature control is preferably provided for each additional stage of compression.
As illustrated in FIG. 1 , flash separator vessel 1 , is a two phase slug containing flash separator which performs the functions of a flash separator and a liquid slug containment vessel. In one embodiment, vessel 1 can have a maximum working pressure of about 175 to about 250 psig. Vessel 1 preferably retains enough liquids to at least partially, and most preferably fully immerse cooling coil 2 . While desirable results can be provided when vessel 1 is a two-phase slug containing flash separator, desirable results can also be produced when vessel 1 is configured as a three-phase slug containing flash separator. Reboiler 3 can be selected to have a maximum working pressure for any given site-location requirements, but in one embodiment, reboiler 3 preferably has a maximum working pressure of about 75 to about 125 psig. Firetube 4 is preferably immersed in the condensates in reboiler 3 . In one embodiment, reboiler 3 preferably heats, under about 35 psig pressure, liquid condensates to a temperature of about 200 to 250 degrees Fahrenheit. Stabilizing column 5 is preferably mounted on top of and in communication with reboiler 3 . Stabilizing column 5 can be filled with pall rings 6 or other types of packing. Stabilizing column 5 preferably performs two functions. First, it aids in stripping high vapor pressure components such as propane, butane, etc., from the condensate. As the condensate falls through the packing, it is heated by the rising heated vapors from reboiler 3 . Heating of the condensate preferably causes some of the high vapor components of the condensate to flash into the vapor phase. Second, stabilizing column 5 preferably aids in refluxing back into the liquid phase some of the lower vapor pressure components of the heated vapors from reboiler 3 . As the heated vapors from reboiler 3 rise through the cooler condensate, the heated vapors are cooled while forming gas bubbles within the condensate. Cooling and intimate contact of the heated vapors with the condensate causes some of the lower vapor pressure components of the heated vapors to return to the liquid phase.
While flowing through heat exchanger 7 , the cool condensate from vessel 1 is preferably heated and the hot condensate from reboiler 3 is preferably simultaneously cooled. Heating coil 8 is preferably immersed in the hot liquids contained in reboiler 3 . Inlet suction scrubber 9 preferably collects and dumps, through dump valve 27 to liquid hydrocarbon storage tank 26 , any liquid that might condense from the collected vapors so that only hydrocarbon vapors are introduced into the compressor. In one embodiment liquid hydrocarbon storage tank 26 preferably has a capacity of at least about 10 barrels, more preferably a capacity of at least about 200 barrels, and most preferably a capacity of at least about 400 barrels.
First and second stages 10 and 11 are two stages of a two-stage compressor. Interstage scrubber 12 is preferably located between an outlet of compression stage 10 and an inlet of compression stage 11 . Various functions of the system of the present invention are preferably controlled, at least in part via PCL (process logic controller) 13 . Condensates separated from the well stream by the high pressure separator or separators enter gas expansion vessel 15 at inlet 16 . Since flash separator 1 and gas expansion vessel 15 are preferably at a lower pressure than the entering well stream, some entrained gas as well as some vapors will flash from the condensate. In one embodiment, back pressure valve 17 is set to hold an operating pressure of about 50 psig on gas expansion vessel 15 and flash separator 1 . In one embodiment, back pressure valve 24 is set to hold a pressure that is about 20 psig less than the lowest operating pressure of the high pressure separators (not shown); or else, back pressure regulator 24 is set slightly below the maximum working pressure of flash separator 1 and gas expansion vessel 15 .
Referring to first stage of compression 10 , 28 is a flow line that connects gas discharge port 29 of first stage compression 10 to point 30 . At point 30 , line 28 splits into lines 31 and 32 . Line 31 connects to cooling coil 2 . Line 32 connects to by-pass port 33 of temperature control valve 34 . Outlet 35 of cooling coil 2 preferably connects to cooled gas port 36 of temperature control valve 34 . Line 37 connects outlet port 38 of temperature control valve 34 to inlet port 39 of interstage scrubber 12 .
In one embodiment, line 128 connects outlet port 129 of interstage scrubber 12 to suction port 40 of second compression stage 11 . Line 41 preferably connects discharge port 45 of second compression stage 11 to point 42 . Point 42 splits into two lines 43 and 44 . Line 44 carries the collected hydrocarbon vapors to the sales meter/sales 210 . Line 43 connects to inlet port 46 of gas recycle pressure control valve 47 .
Line 48 connects discharge 49 of recycle valve 47 to point 50 . Point 50 splits into lines 51 and 68 . Line 51 carries the collected vapors, as well as any recycled vapors required for operation of the compressor, to suction port 52 of first stage of compression 10 .
Referring to gas expansion vessel 15 , line 94 connects from outlet port 95 of gas expansion vessel 15 to inlet port 96 of back pressure valve 24 . Line 98 connects from outlet port 97 of back pressure valve 24 to point 93 . Point 93 splits into two lines 92 and 99 . Line 105 connects to vapor outlet port 106 of expansion vessel 15 to inlet port 130 of back pressure valve 17 . Line 108 connects from outlet port 109 of back pressure valve 17 to inlet port 110 of pressure control valve 22 . Line 132 connects pressure transducer 131 to PLC 13 . Line 134 connects electric liquid level control 133 to PLC 13 .
Referring to flash separator 1 and reboiler 3 , line 69 connects condensate outlet port 68 of flash separator 1 to inlet port 70 of condensate dump valve 23 . Line 72 connects from condensate dump valve outlet port 71 to point 73 . Point 73 splits into two lines 74 and 119 . Line 74 connects from point 73 to cool condensate inlet port 75 of condensate to condensate heat exchanger 7 . Line 76 connects from heated outlet port 77 of condensate to condensate heat exchanger 7 to condensate inlet port 78 of stabilizing column 5 . Line 79 connects from vapor outlet port 80 of stabilizing column 5 to inlet port 81 of back pressure valve 25 . In one embodiment, back pressure valve 25 is set to hold a pressure of about 35 to 45 psig on reboiler 3 . Line 83 connects from outlet port 82 of back pressure valve 25 to point 55 . Point 55 splits into lines 53 and 56 . Line 53 connects outlet port 54 of pressure control valve 22 to point 55 . Line 56 connects point 55 to point 57 . Point 57 splits into two lines 60 and 59 . Line 60 connects point 57 to the inlet 58 of heating coil 8 . Line 59 connects point 57 to bypass port 61 of temperature control valve 62 . Line 64 connects outlet port 63 of heating coil 8 to hot gas port 65 of temperature control valve 62 . Line 20 connects outlet port 66 of temperature control valve 62 to inlet port 67 of inlet scrubber 9 . Line 68 connects vapor outlet port 69 of inlet scrubber 9 to point 50 . Point 50 splits into lines 48 and 51 . Line 48 connects outlet port 49 of recycle valve 47 to point 50 . Line 51 connects point 50 to suction port 52 of first stage of compression 10 .
Reboiler 3 is preferably adjusted via condensate liquid level control 103 . Line 104 is a tubing line that sends a pressure signal from liquid level control 103 to liquid dump valve 90 . Line 84 connects from hot condensate outlet port 85 of reboiler 3 to hot liquid inlet port 86 of condensate to condensate heat exchanger 7 . Line 87 connects from cooled condensate outlet port 88 of condensate to condensate heat exchanger 7 to inlet port 89 of cooled condensate dump valve 90 . Line 92 connects from outlet port 91 of cooled condensate dump valve 90 to point 93 . At point 93 the lines split to form lines 98 and 99 . Line 99 connects from point 93 to point 100 . At point 100 the line splits to form lines 101 and 113 . Line 101 connects from point 100 to inlet 102 of storage tank 26 . Line 113 connects from outlet port 114 of dump valve 27 to point 100 .
Inlet scrubber 9 is preferably adjusted via liquid level control 111 . Line 112 is preferably formed from tubing and carries a pneumatic signal to dump valve 27 . Line 113 connects from outlet port 114 of dump valve 27 to point 100 . Electrical line 116 transmits an electrical signal from transducer 115 to PLC 13 .
Interstage scrubber 12 is preferably adjusted with liquid level control 117 . Line 119 connects outlet port 120 of dump valve 118 to point 73 . Tubing line 121 carries a pneumatic control signal from liquid level control 117 to dump valve 118 .
As used throughout this application, a reference to “normal operation” is intended to mean that the present invention is operating within the normal design capacity without the influence of a large slug of produced liquids and/or liquids and gases; whereas “abnormal” or “upset conditions” means that the present invention is operating under the influence of a slug of produced liquids and/or liquids and gases, which could exceed the capacity of the present invention, particularly the reboiler and compressor. Such abnormal conditions can be caused by arrival of a slug into flash separator 1 and gas expansion vessel 15 .
In embodiments of the present invention wherein three stages of compression are required for a particular application, the preceding description is equally applicable in conjunction with the following discussion regarding this additional third stage. Referring to FIG. 2 , liquids collected in inner-stage scrubber 167 are dumped by liquid level control 170 and dump valve 172 through line 197 to point 73 . At point 188 , the liquids from inner-stage scrubbers 12 and 167 flow through common line 119 to point 73 . Additional stages of compression, such as four or five stages of compression can optionally be used in accordance with the teachings of the present invention simply by duplicating the configuration of this third stage of compression.
Handling of Liquids Under Normal Operation
Condensates from the high pressure separator or separators enter gas expansion vessel 15 at point 16 . The condensates flow downward into flash separator 1 and the gas and vapors collect in the top of gas expansion vessel 15 . As previously described, flash separator 1 is designed to maintain a hydrocarbon liquid level that is most preferably above cooling coil 2 . Any volume of liquid hydrocarbons in excess of that required to maintain the minimum liquid level in separator 1 is sensed by liquid level control 21 and dumped to stabilizing column 5 . While being dumped to stabilizing column 5 , the condensates are heated by heat exchanger 7 . The heated condensates pass downward through the packing 6 in stabilizing column 5 and mix with the heated condensate already in reboiler 3 . The condensates entering reboiler 3 are heated by firetube 4 to a high enough temperature to vaporize the volatile components such as butane, propane, etc which were previously condensed into liquid form. Any other suitable source of heat such as hot oil, electric heaters, and/or captured waste heat may be used in place of firetube 4 .
The level of condensates in reboiler 3 are preferably maintained by liquid level control 103 . When liquid level control 103 senses an increase in condensate level in reboiler 3 , it activates through tubing line 104 and dump valve 90 to dump the stabilized condensate to storage tank 26 . While being dumped to storage tank 26 the hot stabilized condensate is cooled in heat exchanger 7 by the cool condensate from flash separator 1 .
Handling of Liquids Under Abnormal Operation.
As previously described, in some instances, the condensates entering flash separator 1 and gas expansion vessel 15 can arrive suddenly in the form of a large slug of produced liquids and/or liquids and gases. The increased volume of condensates increases the volume of flashed gases and hydrocarbon vapors being released in flash separator 1 , gas expansion vessel 15 , and reboiler 3 . The increased volume of flash gases causes the pressure in line 20 , which carries the flash gases to inlet scrubber 9 , to increase. During slugging conditions the condensate level in flash separator 1 is above the operating level of throttling liquid level control 21 , causing liquid level control 21 to begin completely opening dump valve 23 . Increased opening of dump valve 23 increases the flow of condensates to reboiler 3 , thereby causing an overload of condensate and vapors in reboiler 3 .
Pressure controller 18 monitors through sensing line 19 the pressure in line 20 . Tubing line 203 carries the pressure signal from pressure controller 18 to pressure control valve 22 and liquid Level control 21 . When solenoid 136 is not activated, tubing line 204 carries a pneumatic signal from liquid level control 21 to dump valve 23 . Pressure controller 18 controls the supply pressure going to liquid level controller 21 and pressure control valve 22 . In one embodiment, pressure controller 18 is set to maintain a predetermined set pressure, which can optionally be about 40 psig on line 20 . As long as the pressure in line 20 is at or below the set pressure, pressure controller 18 allows full supply pressure to flow to both pressure control valve 22 and liquid level controller 21 . Full supply pressure holds pressure control valve 22 completely open and allows liquid level controller 21 to operate normally to dump through dump valve 23 the condensate from flash separator 1 to reboiler 3 . Whenever the pressure in line 20 begins to rise above the predetermined set pressure, pressure controller 18 begins reducing the supply pressure going to pressure control valve 22 and liquid level controller 21 . Reduction of the supply pressure causes pressure control valve 22 and dump valve 23 to begin closing. Closing pressure control valve 22 reduces the flow of gas and vapors from gas expansion vessel 15 . Closing dump valve 23 reduces the volume of condensate being dumped from vessel 1 to reboiler 3 .
As previously described, in one embodiment, back pressure valve 17 is set to maintain a pressure of about 50 psig on flash separator 1 and gas expansion vessel 15 , and back pressure valve 24 is set to hold a pressure that is about 20 psig less than the lowest operating pressure of the high pressure separators (not shown). Alternatively, back pressure regulator 24 can be set slightly below the maximum allowable working pressure of flash separator 1 and gas expansion vessel 15 . Flash separator 1 and gas expansion vessel 15 are preferably sized with excess capacity to hold the largest liquid slug that are expected to be produced. Electric liquid level control 133 is preferably installed at a level in gas expansion vessel 15 that is above any liquid level that gas expansion vessel 15 is expected to handle. Pressure transducer 131 , located in the top of gas expansion vessel 15 , is set to send an electrical signal through line 132 to PLC 13 anytime the pressure in gas expansion vessel 15 increases to within about 10 psig of the set pressure of back pressure valve 24 . When PLC 13 receives an electric signal from pressure transducer 131 , PLC 13 sends an electric signal through line 135 to activate solenoid 136 . Activating solenoid 136 causes the pneumatic signal from liquid level control 21 going to dump valve 23 to be vented. Closing dump valve 23 stops condensate from being dumped from flash separator 1 to reboiler 3 , thereby reducing the amount of vapors flowing from reboiler 3 and allowing the full capacity of the compressor to be used to rapidly reduce the pressure in flash separator 1 and gas expansion vessel 15 . As soon as the pressure in flash separator 1 and gas expansion vessel 15 has been reduced about 20 to about 25 pounds per square inch gauge below the set pressure of back pressure valve 24 , PLC 13 opens solenoid 136 re-establishing the connection between liquid level control 21 and dump valve 23 . Re-establishing the connection between liquid level control 21 and dump valve 23 , returns the unit to operation where pressure controller 18 is controlling the opening of pressure control valve 22 and dump valve 23 . After a period of time, the gases and liquids created by the slugging condition are processed and the unit thus returns to normal operation.
Handling of Gases and Vapors Under Normal Operation
Referring to FIG. 1 , as previously described, the relative cool flash gases and vapors flow from flash separator 1 through line 53 to point 55 . At point 55 the flash gases and vapors from flash separator 1 are combined with the hot vapors stripped from the condensate by the heat of reboiler 3 and the stripping action of stabilizing column 5 . The operating pressure of reboiler 3 and stabilizing column 5 is maintained at about 35 psig by back pressure valve 25 . From point 55 the combined gas and vapor stream flows through line 56 to point 57 . At point 57 the combined gas and vapor stream can split into two streams with one portion of the combined gas and vapor stream flowing through line 59 to cool port 61 of temperature control valve 62 and the other portion flowing through line 60 and heating coil 8 to hot port 65 of temperature control valve 62 . Temperature control valve 62 is controlled by thermostat 150 which is mounted in discharge line 28 . Line 28 is the hot discharge line from first stage compression cylinder 10 . Thermostat 150 is set to control temperature control valve 62 to mix the cool and hot portions of the combined gas and vapor stream to obtain a temperature in inlet scrubber 9 high enough to be above the hydrocarbon dew-point of the combined gas and vapor stream and low enough to maintain the temperature of first stage of compression 10 below approximately 300 degrees Fahrenheit. From the common port 66 of temperature control valve 62 , the temperature controlled combined gas and vapor stream flows through line 20 to inlet scrubber 9 . Inlet scrubber 9 separates any hydrocarbon liquids that might be in the combined gas and vapor stream. The liquid level in inlet scrubber 9 is maintained by liquid level control 111 and dump valve 27 . Liquid hydrocarbons separated by inlet scrubber 9 are dumped through dump valve 27 , line 113 , and line 101 into hydrocarbon storage tank 26 . The liquid free combined gas and vapor stream exits inlet scrubber 9 at point 69 and flows through lines 68 and 51 into suction port 52 of first stage of compression 10 . The combined gas and vapor stream exits first compression stage 10 at a temperature in excess of the hydrocarbon dew-point of the combined gas and vapor stream and at an intermediate pressure of about 100 psig. The pressurized and heated combined gas and vapor stream flows through line 28 to point 30 . At point 30 the pressurized and heated combined gas and vapor stream can split into two streams with one portion of the combined gas and vapor stream flowing through line 32 to the hot port 33 of splitter valve 34 and the other portion flowing through line 31 and cooling coil 2 to the cool port 36 of temperature control valve 34 . The condensates in flash separator 1 serve as a heat sink to cool the hot vapors flowing through cooling coil 2 . Temperature control valve 34 is controlled by thermostat 151 which is set to maintain a discharge temperature from second stage of compression 11 that is above the hydrocarbon dew-point of the combined gas and vapor stream but less than 300 degrees Fahrenheit. As further illustrated in FIG. 1 , thermostat 151 is mounted in line 44 . Line 44 is the hot discharge line from second stage of compression 11 . From the common port 38 of splitter valve 34 the temperature controlled combined gas and vapor stream flows through line 37 to the inlet port 39 of interstage scrubber 12 . Interstage scrubber 12 separates hydrocarbon liquids that are in the cooled, pressurized, combined gas and vapor stream from first stage compression 10 . The liquid level in interstage scrubber 12 is maintained by liquid level control 117 and dump valve 118 . Liquid hydrocarbons separated by interstage scrubber 12 are dumped through dump valve 118 and line 119 to point 73 . At point 73 , liquid hydrocarbons from interstage scrubber 12 are combined in line 72 with the condensates from flash separator 1 and flow to heat exchanger 7 . The liquid free combined gas and vapor stream exits interstage scrubber 12 at discharge port 129 and flows through line 128 into the suction port 40 of the second stage of compression 11 . The combined gas and vapor stream exits second stage of compression 11 through discharge port 45 at a temperature that is preferably in excess of the hydrocarbon dew point but less than about 300 degrees Fahrenheit and a discharge pressure that is preferably about 200 to about 500 psig. The pressurized and heated combined gas and vapor stream flows through line 41 to point 42 . During normal operation, the combined gas and vapor stream flows from point 42 through line 44 to sales 210 , but, at times the amount of gas and vapors being produced by the process will not be enough to keep the compressor fully loaded. When needed, pressure regulator 47 causes circulation of enough of the discharged gas and vapors to maintain the suction pressure at about 15 psig in inlet scrubber 9 to flow back through lines 43 , 48 and 68 .
Handling of Gases and Vapors Under Abnormal Operation
Conditions that create slugging have been previously described in the liquid handling section. When a slug of liquid hydrocarbons is introduced into flash separator 1 , the liquid volume displaces, almost instantaneously, the same volume of gas contained in flash separator 1 . In addition to the displaced gases the liquid slug creates, almost instantaneously, flash gases and released vapors. The sudden introduction of an increase in the volume of gases and vapors that the unit is required to process will, unless controlled, overload the capacity of the compressor.
As previously described, gas expansion vessel 15 is designed to control the effects of a sudden introduction of a large volume of gas and vapors into the unit. When the volume of gas and vapors entering gas expansion vessel 15 increase enough to exceed the capacity of the compressor, the pressure in gas expansion vessel 15 is allowed to increase. Increasing the pressure in gas flash separator 1 , has the effect of increasing the gas and vapor capacity of gas expansion vessel 15 as well as slowing the release of gases and vapors from the liquid hydrocarbons.
As previously described, if the pressure in gas expansion vessel 15 increases to a point where gases can be released to storage tank 26 , the full capacity of the compressor is applied to rapidly reduce the pressure in gas expansion 15 by stopping the processing of hydrocarbon liquids in reboiler 3 .
In one embodiment, the speed of the compressor of the present invention is preferably variable from about half speed to full speed. The speed of the compressor in this embodiment is optionally controlled by changing the speed of the drive unit, which can optionally be an electrically-powered drive unit, a pneumatic-powered drive unit, an internal combustion drive unit, or a combination thereof.
Referring to FIG. 1 , pressure transducer 115 is preferably disposed in inlet scrubber 9 . Pressure transducer 115 sends an electric signal through line 116 to PLC 13 . PLC 13 , responding to pressure transducer 115 sends an electric signal to either a VFD (electric drive) or a governor (internal combustion engine). The VFD or governor varies the speed of the driver and in turn the speed of the compressor depending upon the pressure in inlet scrubber 9 .
In case of a mechanical failure, such as a frozen dump line, an inoperable dump valve, etc., which could possibly lead to an uncontrolled release to the environment of hydrocarbon liquids or gases, three-way diverter valve 152 is preferably provided and can be disposed on line 153 , the inlet to flash separator 1 and gas expansion vessel 15 . In this embodiment, under most operating conditions three-way valve 152 remains open to allow hydrocarbon liquids and gases to enter flash separator 1 and gas expansion vessel 15 ; however, if a problem should occur that would allow hydrocarbon liquids to rise high enough in expansion vessel 15 to activate electric level control 133 , an electric signal is preferably sent through line 134 to PLC 13 . PLC 13 then sends an electric signal through line 158 to solenoid 156 . Activating solenoid 156 , in turn, preferably sends a pneumatic signal through tubing line 157 to three-way valve 152 causing the valve to switch and send all the liquid hydrocarbon production to storage tank 26 via flow line 154 . After three-way valve 152 has switched to send all the liquid hydrocarbon production to storage tank 26 , a time delay, which can preferably be anywhere from about 1 minute to about 2 hours and is most preferably between about 15 to about 30 minutes is preferably provided. If electric liquid level control 133 remains activated after the time delay, the problem of a high level can be detected and would thus be considered a major malfunction, thereby causing the unit to automatically shut down. If, during the time delay, the liquid level dropped enough to de-activate electric liquid level control 133 the malfunction would thus be considered a possible temporary problem, and the unit would not be automatically shut down. In this case, three-way valve 152 is preferably switched, thus sending the liquid hydrocarbon production to the unit. As soon as three-way valve 152 switches the liquid hydrocarbon production back to the unit, a new timer is preferably activated and most preferably has a duration of about 15 minutes to about 4 hours and most preferably has a duration of about 1 hour. If during the 1-hour event, the fluid level rises again and activates liquid level control 133 , the problem would not be consider temporary, in which case the liquid hydrocarbon production is again be switched back to storage tank 26 and the unit is automatically shutdown.
While the bulk of this application discusses a two stage compressor embodiment, on applications where the discharge pressure is high, a compressor having three or more stages can be used. All the operating principles remain the same, regardless of whether a two, three, or more stage compressor is used. The main difference between a unit with a two or three stage compressor is that an additional cooling coil, with a temperature control valve, thermostat, etc., is preferably provided on the three stage compressor to control the compression temperature of the third stage. These additional components are readily observed simply by comparing and contrasting FIGS. 1 and 2 .
As illustrated in the three-stage compression system of FIG. 2 , the same configuration as was used in the two stage compression system is also preferably used, except that now, instead of line 44 exiting to the gas sales line, it preferably splits at point 173 before being directed into through line 176 to the hot port 177 of splitter valve 169 and the other portion flowing into cooling coil 165 to the cool port 174 of temperature control valve 169 . The condensates in flash separator 1 serve as a heat sink to cool the hot vapors flowing through cooling coil 165 . Temperature control valve 169 is controlled by thermostat 168 which is set to maintain a discharge temperature from third stage of compression 166 that is above the hydrocarbon dew-point of the combined gas and vapor stream but less than 300 degrees Fahrenheit. As further illustrated in FIG. 2 , thermostat 168 is mounted in line 186 . Line 186 is the hot discharge line from third stage of compression 166 . From the common port 187 of splitter valve 169 the temperature controlled combined gas and vapor stream flows through line 179 to the inlet port 180 of interstage scrubber 167 . Interstage scrubber 167 separates hydrocarbon liquids that are in the cooled, pressurized, combined gas and vapor stream from second stage compression 11 . The liquid level in interstage scrubber 167 is maintained by liquid level control 170 and dump valve 172 . Liquid hydrocarbons separated by interstage scrubber 167 are dumped through dump valve 172 and line 197 to point 73 . At point 73 , liquid hydrocarbons from interstage scrubber 167 are combined in line 72 with the condensates from flash separator 1 and flow to heat exchanger 7 . The liquid free combined gas and vapor stream exits interstage scrubber 167 at discharge port 181 and flows through line 182 into the suction port 183 of the third stage of compression 166 . The combined gas and vapor stream exits third stage of compression 166 through discharge port 178 at a temperature that is preferably in excess of the hydrocarbon dew point but less than about 300 degrees Fahrenheit and a discharge pressure that is preferably about 450 to about 1000 psig. The pressurized and heated combined gas and vapor stream flows through line 184 to point 185 . During normal operation, the combined gas and vapor stream flows from point 185 through line 186 to sales, but, at times the amount of gas and vapors being produced by the process will not be enough to keep the compressor fully loaded. When needed, pressure regulator 47 causes circulation of enough of the discharged gas and vapors to maintain the suction pressure at about 15 psig in inlet scrubber 9 to flow back through lines 43 , 48 and 68 .
In one embodiment, the additional components illustrated in FIG. 2 , which are not illustrated in FIG. 1 , are preferably duplicated again for a four-stage or additional-stage compressor, etc. While embodiments of the present invention preferably use some pneumatic control mechanisms, alternative embodiments of the present invention optionally use other known mechanisms, including but not limited to hydraulic control, electrical control, electro-mechanical control, and combinations thereof in place of one or more of such pneumatic control mechanisms.
Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover, including in the appended claims, all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above and/or in the attachments, and of the corresponding application(s), are hereby incorporated by reference. | A slug-containing vapor recovery system wherein pressure and/or fluid level sensors are provided which monitor for conditions caused by the entry of a slug of hydrocarbon liquid, including that caused by a plunger-lift system. The system can be configured to accommodate virtually any anticipated slug-events. | 1 |
FIELD OF INVENTION
[0001] The invention relates to vibration isolation and damping in hand tools. The embodiments shown and described herein are more particularly for isolating vibrations transferred to the user from the tool when using a pneumatic powered hand tool.
CROSS REFERENCE TO RELATED APPLICATIONS
[0002] None
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] No federal funds were used to develop or create the invention disclosed and described in the patent application.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
[0004] Not Applicable
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 shows an axial cross-sectional view of one embodiment of the present invention.
[0006] FIG. 2 shows a blow-up of one embodiment of the present invention.
[0007] FIG. 3 shows a blow-up of the pneumatic motor in one embodiment.
[0008] FIGS. 4A , 4 B and 4 C show three views of the front cap of the internal isolation layer fashioned for front end exhaust.
[0009] FIGS. 5A , 5 B and 5 C show three views of the rear cap of the internal isolation layer fashioned for front end exhaust.
[0010] FIGS. 6A , 6 B and 6 C show three views of the front cap of the internal isolation layer fashioned for rear end exhaust.
[0011] FIGS. 7A , 7 B, and 7 C show three views of the rear cap of the internal isolation layer fashioned for rear end exhaust.
[0012] FIG. 8 shows a radial cross-sectional view of the main body rear end of one embodiment of the present invention.
[0013] FIG. 9 shows one embodiment of the lock nut fashioned for front end exhaust.
[0014] FIG. 10 shows one embodiment of the lock ring fashioned for front end exhaust
DETAILED DESCRIPTION—LISTING OF ELEMENTS
[0015]
[0000]
Element Description
Element Number
Main Body
1
Main Body Front End
2
Main Body Rear End
3
Fluid Passage
4
Rotary Shaft
5
Pneumatic Motor
6
Throttle Mechanism
7
Intentionally blank
8
Pneumatic Hand Tool
9
Lock Nut
10
Hollow Tube Member
11
Annular Space
12
Throttle Lever
13
Inlet Bushing
14
External Isolation Layer
15
Lock Ring
16
Collet Assembly
17
Stay Pin
18
Rear Thrust Plate
19
Front Thrust Plate
20
Front Bearing Support Plate
21
Cylinder
22
Intentionally blank
23
Internal Isolation Layer
24
Front Cap
25
Rear Cap
26
Pneumatic Motor Front End
27
Pneumatic Motor Rear End
28
Fluid Inlet Hole
29
Fluid Outlet Hole
30
Intentionally blank
31
Rear Bearing
32
Front Bearing
33
Machined Recess
34
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIG. 1 discloses and describes a vibration isolated pneumatic hand tool 9 . When referring to FIGS. 1 , 2 , 3 , 4 B, 5 B, 6 B and 7 B, the left side of the pneumatic hand tool 9 will be referred to as the rear of the pneumatic hand tool 9 and the right side of the pneumatic hand tool 9 will be referred to as the front of the pneumatic hand tool 9 ; additionally, the left side of elements axially disposed with the main body 1 will be referred to as the rear of the element while the right side of the element will be referred to as the front of the element. The pneumatic hand tool 9 in the embodiment shown in FIG. 1 includes a main body 1 formed as a hollow tube member 11 . The main body rear end 3 includes a fluid passage 4 to allow fluid to move into and power the pneumatic motor 6 . In addition to compressed air, the power source may also be selected from the group consisting of electricity or other compressed fluids, such as steam or nitrogen.
[0017] The pneumatic motor 6 is of the type well known to those skilled in the art, and may be of 0.3, 0.6 or 1.0 horsepower, depending on the embodiment. Accordingly, the present invention is not limited by the power rating of the pneumatic motor 6 . The fluid flow to the pneumatic motor 6 is controlled via the throttle mechanism 7 , for which the throttle lever 13 provides the user interface. The throttle mechanism 7 and throttle lever 13 are one type of work control means for controlling the work generating means as recited in the claims.
[0018] In the embodiment shown in FIGS. 1 , 2 and 3 , the pneumatic motor rear end 28 is comprised of a rear thrust plate 19 and a rear bearing 32 , of the type well known to those skilled in the art, engaged with the rear end of a cylinder 22 . The pneumatic motor front end 27 is comprised of a front thrust plate 20 , a front bearing support plate 21 and a front bearing 33 , of the type well known to those skilled in the art, engaged with the front end of said cylinder 22 . The rear bearing 32 has a smaller outer diameter than the inner diameter of the rear thrust plate 19 , and in the embodiment shown in FIG. 3 , the axial dimension of the rear bearing 32 is less than or equal to the axial dimension of the rear thrust plate 19 so that the rear bearing 32 completely seats within the rear thrust plate 19 . The rear bearing 32 engages both the rear end outer surface of the rotary shaft 5 and the inward surface of the rear thrust plate 19 so that the rear thrust plate 19 does not rotate with respect to the rotary shaft 5 . The front bearing 33 has a smaller outer diameter than the inner diameter of the front bearing support plate 21 , and in the embodiment shown in FIG. 3 , the axial dimension of the front bearing 33 is less than or equal to the axial dimension of the front bearing support plate 21 so that the front bearing 33 completely seats within the front bearing support plate 21 . The front thrust plate 20 emulates the outward circumferential shape and size of the front bearing support plate 21 , and in the embodiment shown in FIG. 3 , is axially positioned between and held stationary by the cylinder 22 and the front bearing support plate 21 . The front bearing 33 engages both the front end outer surface of the rotary shaft 5 and the inward surface of the front bearing support plate 21 so that neither the front bearing support plate 21 nor the front thrust plate 20 rotate with respect to the rotary shaft 5 .
[0019] The main body 1 is axially disposed with the pneumatic motor 6 . The rotary shaft 5 of the pneumatic motor 6 extends axially from the main body front end 2 . A collet assembly 17 is engaged with the rotary shaft 5 on the rear end of the collet assembly 17 (as shown in FIG. 2 ). The collet assembly 17 is able to engage a plurality of rotational tools such as a bit, a grinding wheel or a cutter on its front end, as is known to those skilled in the art. The collet assembly 17 is one means of coupling a tool to the rotary shaft 5 as recited in the claims. A lock nut 10 is fashioned, most commonly with threads on the circumferentially outward surface, to engage both the circumferentially inward surface of the main body front end 2 and to engage a portion of the pneumatic motor front end 27 in such a way as to fix the axial position of the pneumatic motor 6 with respect to the main body front end 2 . This is most commonly achieved via threads on a portion of the pneumatic motor front end 27 that engage threads on the lock nut 10 , but other means may be used by those skilled in the art. In one embodiment, a lock ring 16 is fitted with threads on the circumferentially inward surface for engagement with a portion of the circumferentially outward threads on the lock nut 10 so that when the lock ring 16 is tightened against the main body front end 2 , the lock nut 10 is held in place by the lock ring 16 .
[0020] In the present invention an internal isolation layer 24 is placed between the pneumatic motor 6 and the main body 1 in order to minimize the number and magnitude of vibrations transferred from the pneumatic motor 6 to the main body 1 . Additionally, the internal isolation layer 24 provides noise reduction associated with vibrations caused by operation of the pneumatic hand tool 9 . The internal isolation layer 24 may be fashioned to eliminate any metal on metal contact between the main body 1 and the pneumatic motor 6 . In the embodiment shown in FIG. 1 , an external isolation layer 15 is placed on the external surface of the main body 1 in order to minimize the number and magnitude of vibrations transferred from the main body 1 to the user. The external isolation layer 15 also serves to provide comfort to the user's hand and a better grip on the pneumatic hand tool 9 . Further benefits of the external isolation layer 15 are that it serves to reduce sound generated by operation of the pneumatic hand tool 9 and acts as a temperature insulator between the main body 1 and the user's hand. The internal isolation layer 24 is one means of reducing the number and magnitude of vibrations transferred from the work generating means to the main body 1 as recited in the claims.
[0021] In the embodiment shown in FIGS. 1 and 2 , the internal isolation layer 24 consists of two caps, a front cap 25 and a rear cap 26 , with an annular space 12 disposed axially between the front cap 25 and the rear cap 26 . The front cap 25 is formed so as to fully engage both the pneumatic motor front end 27 circumferentially outward surface 6 and the circumferentially inward surface of the main body front end 2 so that the front cap 25 and the circumferentially inward surface of the main body front end 2 fix the radial position of pneumatic motor front end 27 with respect to the main body front end 2 . In the embodiment shown in FIG. 1 , the front cap 25 extends axially over the front thrust plate 20 , front bearing support plate 21 and the small portion at the front of the cylinder 22 that has an outer circumferential shape that emulates the outer circumferential shape of the front thrust plate 20 . When the pneumatic hand tool 9 in the embodiment shown in FIG. 1 is fully assembled, the rear surface of the lock nut 10 is engaged with the front surface of the front cap 25 , preventing movement towards the main body front end 2 within the hollow tube member 11 .
[0022] The rear cap 26 is formed so as to fully engage both the pneumatic motor rear end 28 circumferentially outward surface and the circumferentially inward surface of the main body rear end 3 so that the rear cap 26 and the circumferentially inward surface of the main body rear end 3 fix the radial position of the pneumatic motor rear end 28 with respect to the main body rear end 3 . In one embodiment, the rear cap 26 extends axially over the rear thrust plate 19 and the small portion at the rear of the cylinder 22 that has an outer circumferential shape that emulates the outer circumferential shape of the rear thrust plate 19 . The rear cap 26 is also formed with a stay pin 18 that engages a machined recess 34 in the main body rear end 3 to ensure that only the rotary shaft 5 rotates with respect to the main body 1 when the pneumatic motor 6 is energized, preventing the pneumatic motor 6 from rotating with respect to the main body 1 . When the pneumatic hand tool 9 in the embodiment shown in FIG. 1 is fully assembled, the portion of the main body rear end 3 that is transverse with respect to the rotary shaft (that portion in which the machined recess 34 is located and shown in FIG. 8 ) is engaged with the rear surface of the rear cap 26 so that any corresponding fluid inlet holes 29 and/or fluid outlet holes 30 in the rear cap 26 and the main body rear end 3 are properly aligned for communication. This engagement also prevents any element within the hollow tube member 11 from moving towards the main body rear end 3 . Additionally, this engagement, in conjunction with the front cap 25 and the lock nut 11 , fixes the axial position of the pneumatic motor 6 within the main body 1 .
[0023] The front cap 25 and rear cap 26 are composed of a vibration isolating material, such as an elastomeric ether or ester based polyurethane, or an elastomeric vinyl, suitable for the specific pneumatic hand tool 9 the front cap 25 and rear cap 26 are to be used with. The material of the internal isolation layer 24 is chosen depending on the frequency of vibrations the pneumatic hand tool 9 generates and the typical operating temperatures of the pneumatic hand tool 9 . In the embodiment shown in FIG. 1 , a material with a shore A hardness between 45 and 70 is most effective for minimizing the vibrations transferred from the pneumatic motor 6 to the main body 1 at ambient temperature. The internal isolation layer 24 acts as a shock absorber between the pneumatic motor 6 and the main body 1 to minimize the number and magnitude of vibrations transferred from the pneumatic motor 6 to the main body 1 . In the embodiment shown in FIGS. 1 and 2 , the internal isolation layer 24 ensures that there is no metal to metal contact between the main body 1 and pneumatic motor 6 , which also reduces the amount of sound generated during operation of a pneumatic hand tool 9 . In the embodiment shown in FIG. 1 , the front cap 25 and rear cap 26 are of such an axial dimension as to allow for a predetermined amount of annular space 12 between the axial portions of the front cap 25 and rear cap 26 . The annular space 12 provides an area for exhaust fluid to be discharged from the pneumatic motor 6 . The front cap 25 and rear cap 26 may be slightly compressed in the embodiment shown in FIG. 1 depending on the degree of axial force used to secure the lock nut 10 and/or lock ring 16 within the main body 1 .
[0024] The invention allows pneumatic hand tools 9 to be specified as rear end exhaust or front end exhaust. The internal isolation layer 24 is ported to communicate with different fluid inlet holes 29 and fluid outlet holes 30 in the main body 1 , lock nut 10 or lock ring 16 , depending on the specified exhaust location. In a rear end exhaust pneumatic hand tool 9 (for which one embodiment of the front cap 25 is shown in FIGS. 6A , 6 B and 6 C; and for which one embodiment of the rear cap 26 is shown in FIGS. 7A , 7 B and 7 C), the rear cap 26 is formed with fluid inlet holes 29 that correspond to fluid inlet holes 29 in the main body rear end 3 . The rear cap 26 is further formed with fluid outlet holes 30 that correspond to fluid outlet holes 30 machined into the main body rear end 3 (see FIG. 8 ). The fluid outlet holes 30 machined in the main body rear end 3 communicate with corresponding fluid passages (not shown) in the inlet bushing 14 to exhaust spent fluid to the atmosphere as in designs currently available and well known to those skilled in the art. In a rear end exhaust embodiment, the exhaust passes from the pneumatic motor 6 to the annular space 12 , through the outlet holes 30 in the rear cap 26 and through the outlet holes 30 in the main body rear end 3 to the fluid passages (not shown) in the inlet bushing 14 , from where the exhaust is discharged to the atmosphere. In a front end exhaust pneumatic hand tool 9 (for which one embodiment of the front cap 25 is shown in FIGS. 4A , 4 B and 4 C; and for which one embodiment of the rear cap 26 is shown in FIGS. 5A , 5 B and 5 C), the rear cap 26 is formed with fluid inlet holes 29 that correspond to fluid inlet holes 29 machined in the main body rear end 3 , but the rear cap 26 has no fluid outlet holes 30 in this embodiment (see FIGS. 5A and 5C ). The front cap 25 , lock nut 10 and lock ring 16 are formed with corresponding fluid outlet holes 30 (see FIGS. 4A , 4 C, 9 and 10 ), so that spent fluid exhausted into the annular space 12 passes through the fluid outlet holes 30 in the front cap 25 and the corresponding fluid outlet holes 30 in the lock nut 10 and lock ring 16 , from where the exhaust is discharged to the atmosphere.
[0025] The present invention allows for the front cap 25 and rear cap 26 of the internal isolation layer 24 to be easily disengaged from a pneumatic motor 6 if the pneumatic motor 6 becomes dysfunctional. The front cap 25 and rear cap 26 may then subsequently be easily engaged with a properly functioning pneumatic motor 6 . The front cap 25 , rear cap 26 and the properly functioning pneumatic motor 6 may easily be fitted inside the original main body 1 . Consequently, the main body 1 , front cap 25 and rear cap 26 may be used with a plurality of pneumatic motors 6 . Using the present invention, the pneumatic motor 6 of a pneumatic hand tool 9 may easily be removed and replaced or serviced without refitting the main body 1 with new or additional components to the internal isolation layer 24 or external isolation layer 15 . This allows for easily servicing the pneumatic motor 6 of a pneumatic hand tool 9 employing the disclosed internal isolation layer 24 and/or external isolation layer 15 . Embodiments of the present invention include, but are not limited to, pneumatic hand tools 9 using a 0.3, 0.6 or 1.0 horsepower pneumatic motor 6 . The pneumatic motor 6 as shown is one type or means of generating work, as recited in the claims, which may also be connected to other power sources such as an internal combustion system as recited in the claims.
[0026] In the embodiment shown in FIG. 1 , the external isolation layer 15 is engaged with the circumferentially outward portion of the main body 1 and occupies the surface of the main body 1 that is in contact with the user when the pneumatic hand tool 9 is in operation. The external isolation layer 15 need not engage the entire circumferentially outward surface of the main body 1 , but may be fashioned to engage such area of the circumferentially outward surface of the main body 1 that provides the user interface without interfering with the operation of the throttle lever 13 . The external isolation layer 15 may be affixed to the main body 1 by any means known to those skilled in the art, or it may be molded to the shape of the main body 1 for an interference fit between the main body 1 and the external isolation layer 15 . In the embodiment shown in FIG. 1 , the external isolation layer 15 is fashioned of a thickness between one-eighth of an inch and three-sixteenths of an inch to minimize vibrations associated with a specific type or style of pneumatic hand tool 9 or to alleviate the symptoms associated with hand fatigue of a specific physical ailment. In this way, the external isolation layer 15 acts as a shock absorber between the main body 1 and the user to minimize the number and magnitude of vibrations transferred from the main body 1 to the user. The external isolation layer 15 also minimizes the hand fatigue experienced by the user during operation of the pneumatic hand tool 9 while simultaneously providing for a better grip. The external isolation layer 15 also reduces the amount of sound generated during operation of a pneumatic hand tool 9 and acts as a temperature insulator between the main body 1 and the user during operation. The material for the external isolation layer 15 is chosen in the same manner as the material for the internal isolation layer 24 . In some embodiments, such as the one disclosed in FIG. 1 , the external isolation layer 15 and the internal isolation layer 24 are constructed of a similar material. In the embodiment shown in FIG. 1 , the main body 1 is formed in an ergonomic wave contour and the external isolation layer 15 follows that same ergonomic wave contour so that the user's fingers may engage the trough of the wave contour, thereby further reducing the resulting amount of fatigue in the user's hand after operation of the pneumatic hand tool 9 . The external isolation layer 15 and ergonomic wave contour as shown are one means of surrounding the main body 1 , as recited in the claims.
[0027] It should be noted that the present invention is not limited to the specific embodiments pictured and described herein, but is intended to apply to all similar apparatuses for minimizing the number and magnitude of vibrations transferred from a pneumatic hand tool 9 to the user during operation. Accordingly, modifications and alterations from the described embodiments will occur to those skilled in the art without departure from the spirit and scope of the present invention. | A powered hand tool comprising a pneumatic motor including a cylinder, a main body formed as a hollow tube member, a main body rear end being formed with a fluid inlet and a fluid outlet, said main body being axially disposed for engagement with said pneumatic motor, a main body front end with an interior surface fitted for engagement with a lock nut, said pneumatic motor having a rotary shaft axially extending out of said main body front end wherein the diameter of said pneumatic motor is smaller than the diameter of said hollow tube member, an internal isolation layer composed of a vibration isolation material placed in said hollow tube member so that said vibration isolation material is engaged with and adjacent said ends of said hollow tube member and said pneumatic motor. | 1 |
The present invention relates to a panel system and a method of installing a light weight structural system to provide a safe, long lasting, weatherproof, maintenance free surface. The panel may be a composite material with fiberglass reinforced polymer (FRP). It may be covered with a gel coat or a painted finish. The panel provides structural strength to support loads and forces as a combination roof and decking material as well a sidewall construction building panel.
BACKGROUND OF THE ART
The present invention is a non-metal panel system with advantages over known metal panel systems, metal panel foam laminate systems, FRP panel systems, and FRP foam combination panel systems.
Prior art metal panel roof systems are traditionally divided into two categories, architectural and structural. An architectural system is generally a steep slope system, used for visual impact or aesthetics. It typically requires a supporting deck with a minimum slope of 3 inch per foot of slope with water shedding or hydrokinetic seams. A structural system will tend to be a low slope system, although a minimum of ¼ inch per foot of slope is typically used to provide runoff. A structural system can support its own weight without a deck. The seams of a structural system are water tight or hydrostatic and are designed to withstand water pressure.
These types of metal panels and seams come in a variety of shapes and sizes. Panels profile or shapes can be of corrugated style design, trapezoidal rib, flat, or a specialty design. Seams may have an interlocking or meshing male/female design, although non-meshing ends covered with a cap are also used. The seams may be hand formed, roll formed, or brake formed. Types of seam can include flat, corrugated, trapezoidal rib, batten, vertical leg. The term “standing seam” is often used as a generic description for most kinds of metal roofing. It comes from the fact that the seams stand vertically upright above the panel flats. Because a standing seam located above the panel is therefore out of the path of water that is either shedding from the roof or ponding or accumulating on the roof, the standing seam provides superior waterproofing, even when a hydrostatic seal of the seam may fail. These panels may be attached to supporting substructures with through panel fasteners. A number of fastening means are known, but a common means is a simple bolt and washer assembly with a variety of sealing methodologies. There are a variety of other attachment methods that do not require penetration of the panel surfaces, such as the clip system described in U.S. Pat. No. 4,649,684 to Petree. Another non-penetrating fastener is that taught by Greenberg in U.S. Pat. No. 5,737,892.
The same type of panels and seaming techniques are used commonly in the sidewall panels of buildings as are used in roofs, although waterproofing is a reduced concern. These panels are of metals, such as steel, copper, aluminum, etc., of typical thicknesses about 0.015 inches to about 0.051 inches. Similar to this type of metal panel roof and wall construction is roof and wall panel construction composed of panels that contain an insulated core with outer- or inner metal skins with similar design profiles and patterns.
Today, fiberglass-reinforced polymer panel roof and wall panel construction is similar, if not identical to, metal panel roof and wall construction. A primary difference is that FRP panel or panel system does not use a through panel attachment methodology combined with a standing seam lateral adjoinment. Lateral flat panel seams and longitudinal flat seams often require a field applied sealant, especially in combination with some form of sealing member, such as a gasket. These seams are vulnerable to problems in field craftsmanship as well as the durability and maintenance of the sealant used. In other words, an otherwise acceptable or even superior FRP panel roofing system can result in complaints against the manufacturer due to factors beyond that manufacturer's control. One FRP panel system using through panel attachment methodology and flat overlap seams is described in U.S. Pat. No. 5,625,999 to Buzza.
Other plastic panel technology that has been developed in recent years includes the panel coupling assemblies of Conterno, assigned to Politec Polimeri Tecnici S. A. of Italy, as disclosed in U.S. Pat. No. 6,347,495 B1 (Feb. 19, 2002) and U.S. Pat. No. 6,202,382 B1 (Mar. 20, 2001).
It is a previously unmet object of the invention to provide a non-metal panel system that employs a non-penetrating method of attachment, to eliminate penetrating fasteners that are the source of leaks, which require routine maintenance to ensure their tightness or attachment and watertight seal and which restrain movement of the panel from expansion, contraction and other stresses.
SUMMARY OF THE INVENTION
This and other objects of the invention are provided by a panel system for attaching to a substructure of a roof or a wall. Such a panel system comprises at least one pair of adjacent panels and at least one clip for connecting each said pair of adjacent panels. Each of the panels comprises an elongate body with a base section having first and second side edges. A first leg is attached at a first end thereof at the first side edge and a second leg is attached at a first end thereof at the second side edge. These first and second legs extend generally perpendicularly from the base section. Each side edge further comprises a groove or channel. In order to attach the first leg of a first panel to the second leg of a second panel, each of the first and second legs has one of a complementary pair of mating means arranged at a second end therof. Each of the clips comprises a flat bottom that is arranged and designed to have a bottom surface fastened to the substructure. Each clip further has a left, a right and a central support member that extends from an upper surface of the flat bottom. Each of the left and right support members has an enlarged upper surface for bearing against the base section of a panel and receiving its weight. The central support member has a pair of outwardly extending tongues or tabs to be received in the channel or groove of the panels. At least one clip fits between each pair of the adjacent panels.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will best be understood when reference is made to the detailed description of the invention and the accompanying drawing, wherein identical parts are indentified by identical reference number and wherein:
FIG. 1 shows a cross sectional view of a first embodiment panel;
FIG. 2 shows a cross sectional view of ends of first embodiment panels being joined together;
FIG. 3 shows a cross sectional view of a second embodiment having an insulative hollowed or foam containing underlying inner core;
FIG. 4 shows a cross sectional view of ends of second embodiment panels being joined together;
FIG. 5 shows a clip being used to fasten a pair of first embodiment panels;
FIG. 6 shows a clip being used to fasten a pair of second embodiment panels; and
FIG. 7 shows a cross sectional view of two panels of a third embodiment of the present invention being joined by a clip.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an end or cross section view of the panel 10 of a first embodiment of the present invention, it being understood that this cross sectional profile of the panel 10 is consistent throughout a longitudinal direction of the panel, that longitudinal direction extending normal to the plane of the drawing sheet. For that reason, the section depicted could occur anywhere along the longitudinal direction. The panel 10 comprises a generally U-shaped elongate body having a planar base section 12 with first and second vertical legs 14 , 16 , one of the legs positioned at the two side edges of the base section, that is, the sides when viewed in the cross section view as presented. One of the vertical legs, in this case, first vertical leg 14 , has a first part 18 of a means 20 for mating disposed at a top end thereof. The other vertical leg, that is, second vertical leg 16 , has a second part 22 of the mating means 20 disposed at a top end thereof. In the partical embodiment shown, the first mating means part 18 is a female portion and the second mating means part 22 is a male portion.
The juxtaposition of two adjacent panels 10 a, 10 b is shown in FIG. 2 . In the embodiment illustrated, the second mating means part 22 on panel 10 b fits into the first mating means part 18 of panel 10 a, forming the vertical standing seam. A longitudinal strip or band 24 of a resilient sealent of gasket can be applied to one of the mating faces of the first or the second mating means parts 18 , 22 to render the seam water-tight. If this strip or band 24 is adhered to one of the mating means parts 18 , 22 , it should not be adhered to the other, as adhesion to both the first and second mating means parts 18 , 22 , could result in restraining the panels from expansion in the longitudinal direction, causing stresses in the panel. However, it is desirable that the strip or band 24 be maintained in compression by the mating of parts 18 , 22 .
FIGS. 1 and 2 also show another feature of the panel 10 . Each side edge is also provided with a groove or channel 26 , intended to receive a tongue of a clip, as described in more detailed below. For structural integrity, as well as for facilitating the guiding of the panels 10 into place, each groove or channel 26 has a pair of built-up gussets 28 , 30 , one of the gussets above the channel and the other below the channel. Also notable in FIG. 2 is the vertical channel 32 available for receiving an upstanding member of the clip used to secure the panel assembly to the roof.
FIGS. 3 and 4 are similar to FIGS. 1 and 2, but illustrate a second embodiment of the present invention. FIG. 3 shows an end or cross section view of the panel 110 of this second embodiment, it again being understood that this cross sectional profile of the panel 110 is consistent throughout a longitudinal direction of the panel, that longitudinal direction extending normal to the plane of the drawing sheet. For that reason, the section depicted could occur anywhere along the longitudinal direction. The panel 110 comprises a generally U-shaped elongate body, but the base section 112 is no longer a relatively thin plane, but is instead a top plane 113 with an underlying cavity 115 , bounded by a bottom plane 117 , the cavity being shown in FIG. 3 as being filled with an insulative foam 119 . The first and second vertical legs 14 , 16 are identical to those in FIGS. 1 and 2, and they operate identically, with means 20 for mating comprising a first part 18 disposed at a top end of first vertical leg 14 and a second part 22 disposed at a top end of second vertical leg 16 . As in FIGS. 1 and 2, the first mating means part 18 is a female portion and the second mating means part 22 is a male portion.
The juxtaposition of two adjacent panels 110 a, 110 b is shown in FIG. 4 . In the embodiment illustrated, the second mating means part 22 on panel 110 b fits into the first mating means part 18 of panel 10 a, forming the vertical standing seam. A longitudinal strip or band 24 of a resilient sealent or gasket can be applied to one of the mating faces of the first or the second mating means parts 18 , 22 to render the seam water-tight. If this strip or band 24 is adhered to one of the mating means parts 18 , 22 it should not be adhered to the other, as adhesion to both the first and second mating means parts 18 , 22 , could result in restraining the panels from expansion in the longitudinal direction, causing stresses in the panel. However, it is desirable that the strip or band 24 be maintained in compression by the mating of parts 18 , 22 .
FIGS. 3 and 4 also show another feature of the panel 110 . Each side edge is also provided with a groove or channel 26 , intended to receive a tongue of a clip, as described in more detail below. For structural integrity, as well as for facilitating the guiding of the panels 110 into place, each groove or channel 26 has a pair of built-up gussets 28 , 30 , one of the gussets above the channel and the other below the channel. Also notable in FIG. 2 is the vertical channel 32 available for receiving an upstanding member of the clip used to secure the panel assembly to the roof. Additionally a gusset 34 is shown in the cavity 117 as providing support. In the second embodiment, the vertical channel is longer, as it extends significantly below the channel 26 .
One method of securing the panel 10 of the present invention to roof is shown in FIG. 5, where a clip 60 is disclosed and is shown in side section. The clip 60 can be a continuous member or it can be discontinuous, depending on the particular amount of support needed in a particular application. The clip 60 has a flat bottom 62 , which may be seated upon and secured to an underlying building member, such as a purlin (not shown). The clip also has three upstanding members extending up from the bottom. These are the left and right supports 64 , 66 and a central support 68 . In the embodiment shown, the central support 68 terminates at an upper end in a pair of horizontal tabs 70 which fit into the channels 26 of the panel 10 , while upper surfaces 72 of the left and right supports provide support to the planar portion 12 of the panel. In at least one additional design, the central support could extend further upwardly into the vertical channel 32 , as is shown in broken lines as part 74 . Of course, other clip options are available for securing the panels to the building. As noted the clip 60 can vary in length and size, and may even be continuous in length spanning the entire gap between adjacent purlins. This type of clip design allows the panel to expand/contract over its length along the channels/grooves freely. In essence the panel and panel system is free floating in the longitudinal direction. Panel weight is borne by upper surface 72 and tabs 70 .
FIG. 6 shows a second clip 160 for securing the panel 110 of the present invention to a roof. This clip 160 is similar to clip 60 , but the central support 168 is significantly longer to account for the thicker base portion of the panel 110 .
It will be appreciated that the clips 60 , 160 described do not require any penetration of the panels to secure them to the roof and the clips do not impede longitudinal movement of the panels along the clip, thereby allowing expansion, contraction, etc. of the panels. Similarly, a degree of lateral movement is also allowed by the clip design.
In the embodiment of the panel shown in FIGS. 3 and 4, the panel may have a plastic or resin portion comprising phenolic, epoxy, polyester, vinyl ester, and polyurethane resins among others. The fiberglass portion of the panel may include chopped strands of fiberglass, fiberglass rovings, a variety of fiberglass mats from wet laid process, woven, laminated, or stitch knitted, and variety of other processes including a variety of additional reinforcing materials such as polyester, carbon, KEVLAR, etc. In some embodiments, at least the exterior or weather bearing surface of the panel may be painted or covered with a gel coat.
The panel profiles envisioned by this disclosure may formed by continuous methods such as extrusion, pultrusion, or by a variations thereof in lengths of example of 50 to 100 feet or more, limited only by the equipment used to form and handle the panels. Other finite methods of forming include variations of forms of molding such as open mold, spray lay-up, or closed molding. Resins can include both thermosetting of thermoplastic materials.
Even a third embodiment of the invention, exemplified by panel 210 , is shown in FIG. 7 . It is again understood that the cross sectional profile shown of the panel 210 is consistent throughout a longitudinal direction of the panel, that longitudinal direction extending normal to the plane of the drawing sheet. Actually, FIG. 7 shows two panels 210 a, 210 b juxtaposed as they would be in operation, using a clip 300 , especially a clip similar to that disclosed in the Petree '684 patent cited above. The panel 210 comprises a generally U-shaped elongate body, but the base section 212 is not a relatively thin plane, as in panel 10 , but is instead a top plane 213 with an underlying cavity 215 , bounded by a bottom plane 217 . Unlike the embodiment in FIG. 3, the embodiment in FIG. 7 is not filled with an insulative foam, although it certainly would be in some embodiments of the invention. The base section 212 is bounded on its ends by first and second vertical legs 214 , 216 , one of each being shown on the respective panels 210 a, 210 b. The first vertical leg 214 , has a first part 218 of a means 220 for mating disposed at a top end therof. The other vertical leg, that is, second vertical leg 216 , also has a first part 218 of the mating means 220 disposed at a top end thereof. It is noted that the first mating parts 216 , 218 of the respective vertical legs are identical, although mirror images of each other. They do not mate with each other. To achieve the mating of the first mating parts, a second mating part 222 is required and this is provided by cap member 302 , shown operatively engaged on the panels 210 a, 210 b. In the particular embodiment shown, the first mating part 218 are male portions and the second mating part 222 is a female portion.
The embodiment shown in FIG. 7 does not show any equivalent of the longitudinal strip or band 24 of a resilient sealant or gasket which is applied to mating faces in the first two embodiments. This does not mean that such a resilient sealant or gasket would not be used. However, if the sealant or gasket were used, the primary place for positioning it would be along the V-shaped gap between the cap member 302 and the tops of mating parts 218 . Alternately, it would be desirable in some situations to use a T-shaped gasket in which the horizontal arms would lie in the V-shaped gap and the vertical arm would extend in the vertical gap between the mating parts 218 .
FIG. 7 also shows other features of the panel 210 and clip 300 . Each side edge is also provided with a groove or channel 226 , intended to receive a tongue 304 of the clip, but in this case the groove 226 is formed in the first mating part 218 at the top end of the vertical leg 214 , 216 , rather than at an intermediate portion of the leg, especially an intermediate portion near the base section 212 . In this way, the built-up head 240 of the first mating part 218 acts as a gusset similar to one of the gussets 28 , 30 of the other embodiments and the functionality of the second gusset is provided by a portion of the cap member 302 , specifically part 306 .
A few points are in order about cap member 302 . The cap member would usually be selected from a rigid plastic material, but the material should be selected so that the channel opening 308 may selectively expand as the cap member 302 is pushed downwardly onto the respective first mating parts 218 , but resiliently restore to this initial size once engaged. To help achieve this, one known method is to have a portion 308 of the cap member be less thick than other portions, so that some flexibility is provided at that point. | A light-weight structural system is provided by a panel system having at least one pair of adjacent panels ( 10 ) and a clip ( 60 ) positioned between the adjacent panels. A groove or channel ( 26 ) in each panel receives an outwardly-extending tongue or tab ( 70 ) on the clip. Built-up gussets ( 28, 30 ) on the panels above and below the groove or channel provide structural strength. Upwardly-extending support members ( 64, 66 ) on the clip bear weight from the panels. A base section ( 62 ) of the clip allows the clip to be fixed to a roof or wall substructure. The panels can be formed from thermosetting or thermoplastic polymers, especially fiber-reinforced polymers. | 4 |
[0001] The work leading to this invention was supported in part by Grant Nos. DK08753 and RO1DK48042 from the National Institutes of Health. The U.S. Government may have certain rights to this invention.
FIELD OF THE INVENTION
[0002] This invention is directed to specific antagonists of glucose-dependent insulinotropic polypeptide (GIP). This invention is also directed to treatment of non-insulin dependent diabetes through increasing glucose tolerance without requirement for increased serum insulin, the treatment of obesity by the administration of a GIP antagonist, the development of nonpeptide GIP antagonist compounds, and compositions.
BACKGROUND
[0003] Insulin release induced by the ingestion of glucose and other nutrients is due part to both hormonal and neural factors (Creutzfeldt, et al., 1985 , Diabetologia 28:565-573). Several gastrointestinal regulatory peptides have been proposed as incretins, the substance(s) believed to mnediate the enteroinsular axis and that may play a physiological role in maintaining glucose homeostasis (Unger, et al., 1969 , Arch. Intern. Med, 123:261-266; Ebert R., et al. 1987 , Diab. Metab. Rev., 3:1-16; Dupré J., 1991, “The Endocrine Pancreas.” Raven Press. New York, p 253). Among these candidates, only glucose-dependent insulinotropic polypeptide (GIP) and glucagon like peptide-1 (7-36)(GLP-1) appear to fuilfill the requirements to be considered physiological stimulants of postprandial insulin release (Dupré, et al. 1973, J. Clin. Endocrinol. Metab., 37:826-828; Naauck, et al., 1989 , J. Clin. Endocrinol. Metab., 69:6540662; Kreyinann, et al. 1987 , Lancet, 2:1300-1304; Mojsov, et al., 1987 , J. Clin. Invest., 79:616-619).
[0004] Following oral glucose administration, serum GIP levels increase several fold (see Cleator, et al., 1975 , Am. J. Surg., 130:128-135; Nauck, et al. 1986 , J. Clin. Endocrinol. Metab., 63:492-498; Nauck, et al., 1986 , Diabetologia, 29:46-52; Salera, et al., 1983 , Metabolismn, 32:21-24; Kreymann, et al., 1987 , Lancet, 2:1300-1304), and although the increment in plasma GLP-1 concentration in response to glucose is also significant, it is far smaller in magnitude (Kreymann, et al., 1987 , Lancet, 2:1300-1304; Orskov, et al., 1987 , Scand J. Clin. Lab. Invest., 47:165-174; Orskov, et al., 1991 , J. Clin. Invest., 87:415-423; Shuster, et al., 1988 , Mayo Clin. Proc., 63:794-800). In human volunteers, Nauck et a. (1993 , J. Clin. Endocrinol. Metab., 76:912-917) showed that GIP was a major contributor in the incretin effect after oral glucose, whereas GLP-1 appeared to play a major role. Shuster et al. (1988) also suggested that GIP was the most important, but not the sole, mediator of the incretin effect in humans.
[0005] Some studies have demonstrated that GIP and GLP-1 are equally potent in their capacity to stimulate insulin release (Schmid, et al., 1990 , Z. Gastroenterol, 28:280-284; Suzuki, et al., 1990 , Diabetes, 39:1320-1325), whereas others have suggested that GLP-1 possesses greater insulinotropic properties (Siegel, et al. 1992 , Eur. J. Clin. Invest. 22:154-157; Shimra, et al. 1988 , Regu. Pept., 22:245-252). Recently, using a putative specific antagonist to the GLP-1 receptor, exendin (9-39), Wang et aL have demonstrated that exenden reduced postprandial insulin release by 48% and thus concluded that GLP-1 might contribute substantially to postprandial stimulation of insulin secretion (Wang, et al. 1995 , J. Clin. Invest., 95:417-421). More recent studies, however, have shown that exendin might also displace GIP binding from its receptor and thereby reduce GIP-stimulated cyclic adenosine monophosphate (cAMP) generation (Wheeler, et al. 1995 , Endocrinology, 136:4629-4639; Gremlich, et al. 1995 , Diabetes, 44:1202-1208). Therefore, the antagonist properties of exendin (9-39) might not be limited to GLP-1.
[0006] The availability of a GIP-specific receptor antagonist would be invaluable for determining the precise roles of these peptides in mediating postprandial insulin secretion.
SUMMARY OF THE INVENTION
[0007] It is an object of this invention to provide specific antagonists of glucose-dependent insulinotropic polypeptide (GIP).
[0008] It is another object of this invention to provide alternative methods for treatment of non-insulin dependent diabetes which increase glucose tolerance without requirement for increased serum insulin, for treatment of obesity with a GIP antagonist which inhibits, blocks or reduces glucose absorption from the intestine of an animal, and for development of nonpeptide GIP antagonist compounds.
[0009] In one embodiment, this invention provides an antagonist of glucose-dependent insulinotropic polypeptide (GIP) consisting essentially of a 24-amino acid polypeptide corresponding to positions 7-30 of the sequence of GIP.
[0010] In another embodiment, this invention provides a method of treating non-insulin dependent diabetes mellitus in a patient comprising administering to the patient an antagonist of glucose-dependent insulinotropic polypeptide (GIP).
[0011] In yet another embodiment, this invention provides a method of improving glucose tolerance in a mammal comprising administering to the mammal an antagonist of glucose-dependent insulinotropic polypeptide (GIP).
[0012] Using a reporter L-cell line stably transfected with rat GIP receptor cDNA (LGIPR2), the inventors have identified a fragment of GIP [GIP (7-30)-NH 2 ] as a specific GIP receptor antagonist. This antagonist (referred to as ANTGIP) inhibited GIP-stimulated intracellular cAMP production in vitro, and ANTGIP competed. with GIP for binding to cellular receptors, but did not complete with GLP-1. ANTGIP inhibited the GIP-dependent release of insulin in vivo, but ANTGIP had no effect on glucose-, GLP-1-, GIP-, and arginine-induced insulin release in anesthetized rats. In conscious rats, ANTGIP inhibited postprandial insulin release, without significantly affecting the serum glucose concentration. However, despite its inhibiting effect on insulin release, ANTGIP has been discovered to enhance glucose tolerance in an oral glucose tolerance test.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1A and 1B show cAMP-dependent β-galactosidase production by LGIPR2 cells in the presence of GIP or various GIP fragments.
[0014] FIG. 2 shows dose-dependent inhibition of ANTGIP on GIP-included cAMP-dependent β-galactosidase production in LGIPR2 cells.
[0015] FIG. 3 shows competition of 125 I-GIP and 125 I GLP-l(inset) binding by GIP, GLP-1 and ANTGIP.
[0016] FIG. 4 shows plasma insulin concentrations (±SE) in fasted anesthetized rats after 30 min of GIP, ANTGIP, or 0.9 NaCl infusion.
[0017] FIG. 5 shows plasma insulin concentrations (±SE) in fasted anesthetized rats after a 30-min infusion of GLP-1 (0.4 nmol/kg), glucose (0.8 g/kg), or arginine (375 mg/kg) with (open bars) or without (solid bars) ANTGIP (100 nmol/kg) (n=6 for each group).
[0018] FIG. 6 shows postprandial plasma insulin and serum glucose levels (±SE) in conscious trained rats.
[0019] FIG. 7 shows plasma insulin level following oral glucose administration to rats with or without ANTGIP injection.
[0020] FIG. 8 shows plasma glucose level following oral glucose administration to rats with and without ANTGIP injection.
[0021] FIG. 9 shows the effects of the GIP receptor antagonist, ANTGIIP, on the absorption of free D-glucose from the lumen of the jejunal test segment.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Glucose-dependent insulinotropic polypeptide (GIP) is 42-amino acid hormone that was originally described as a inhibitor of acid secretion. More recently, however, it has been shown to be potent stimulant for the release of insulin from the-endocrine pancreas.
[0023] The inventors have confirmed previous studies (Rossowski, et al., 1992 , Regu. Pep., 39:9-17) indicating that truncated GIP [GIP (1-30)-NH 2 ] might be one of the biologically active forms of mature GIP. As shown in FIG. 1 , GIP (1-30)-NH 2 was nearly equipotent to GIP (1-42) in stimulating cAMP dependent β-galactosidase production in LGIPR2 cells. These findings are consistent with the observations of Wheeler, et al. (1995), reported that both GIP(1-42) and GIP(1-30) exhibited similar stimulatory properties for cAMP production in COS-7 cell transiently expressing GIP receptor cDNA. Moreover, Kieffer et a. (1993 , Can. J. Physiol. Phannacol., 71:917-922) found that GIP (1-30) competitively inhibited binding of GIP (1-42) to the GIP receptor in βTC3 cells. These data suggest the possibility of cellular processing of GIP (1-42) to yield biologically-active a-amidated GIP (1-30).
[0000] Physiological Effects of GIP Antagonists
[0024] Insulin release induced by the ingestion of glucose and other nutrients is due in part to both hormonal and neural factors (see, e.g., Creutzfeldt, et al., 1985). Although a number of gastrointestinal regulatory peptides have been proposed as putative incretins; GIP and GLP-1 are the most likely physiological insulinotropic peptides. Although both GIP and GLP-1 possess significant insulinotropic properties, controversy exists regarding their relative physiological roles in stimulating insulin release.
[0025] Using a GLP-1 receptor antagonist exendin (9-39), Wang et al. (1995) detected a 50% decrease in postprandial insulin secretion in exendin-treated rats. Administration of exendin also reduced 70% of insulin release following intraduodenal glucose infusion (Kolligs, et al., 1995 , Diabetes, 44:16-19). Recent studies, however, have demonstrated that exendin also displaced GIP binding from its receptor, and inhibits cAMP generation in response to GIP stimulation (Wheeler, et al. 1995; Gremlich, et al. 1995). Therefore, the antagonist properties of exendin do not appear to be GLP-1 specific.
[0026] Successful synthesis by the present inventors of a specific GIP receptor antagonist greatly facilitates investigation of the relative contribution of GIP in mediating the enteroinsular axis. The GIP fragment ANTGIP [GIP (7-30)-NH 2 ] specifically inhibits various GIP-dependent effects. In LGIPR2 cells, ANTGIP inhibited the cANW response to GIP in a concentration-dependent manner (see FIG. 2 ), and in βTC3 cells, the antagonist displaced GIP binding from its receptor (see FIG. 3 ). Furthermore, ANTGIP completely abolished the insulinotropic properties of GIP in fasted anesthetized rats, while not affecting GLP-1, glucose-, or arginine-stimulated insulin release indicating that this antagonist is GIP-specific. ANTGIP alone demonstrated no stimulatory effect on in-sulin release or cAMP generation in either intact rats or LGIPR cells, indicating the absence of any agonist properties. Studies demonstrated that even at a concentration as high as 10 4 M, ANTGIP did not stimulate a detectable increase in cAMP-dependent β-galactosidase level in LGIPR2 cells.
[0027] The inventors have observed a 72% decrease in postprandial insulin release in response to the administration of ANTGIP to rats. ANTGIP did not affect GLP-1 binding to its receptor, and the insulinotropic effect of GLP-1 is preserved in vivo in the presence of ANTGIP. Furthermore, postprandial GLP-1 levels were not affected by ANTGIP. These findings are consistent with a dominant role for GLP in mediating the enteroinsular axis.
[0028] Wang et al. demonstrated an approximate 50% reduction in postprandial insulin levels in exendin-treated rats, whereas plasma glucose levels increased minimally from 7.5 to 8.7 nmmol/1. The physiological significance of this minor increment in glucose level was not clear to Wang, et al. The inventors found that serum glucose concentrations remained largely unchanged despite a marked decrease in serum insulin levels in ANTGIP-treated rats. The results of the present study are consistent with the notion that insulin is not the sole mediator of glucose homeostasis, but that glucose maintenance is dependent on numerous neurohumoral factors. These factors include horrmones, such as pancreatic glucagon, cortisol, and growth hormone, and physiological events, including peripheral and hepatic glucose uptake.
[0029] The results of the present studies demonstrate that GIP (7-30)-NH 2 is a specific receptor antagonist of naturally occurring GIP. GIP (7-30)-NH 2 inhibits GIP-induced cAMP generation and insulin release, but does not affect the insulinotropic effects of other secretagogues such as glucose, arginine, and GLP-1. Furthermore, circulating insulin levels decreased by 72% in response to the concomitant administration of GIP (7-30)-NH 2 to chow-fed rats, indicating that GtP plays a dominant role in mediating postprandial. insulin secretion.
[0030] Strikingly, although GIP (7-30)-NH 2 reverses the insulin stimulatory properties of the parent compound, when the GIP antagonist was administered to rats (injected intraperitoneally), oral glucose tolerance was improved: a significant decrease in serum glucose levels was detected at all time points in all rats. In addition, plasma insulin levels were also diminished in these same rats. These results are surprising—with the decrease in insulin release, one would expect an increase in serum glucose. However, GIP has several other peripheral effects which may include an affect of GIP on peripheral glucose utilization, and the decrease in serum glucose levels seen with GIP might be due to such an effect.
[0031] The effect of GIP antagonists on serum glucose levels in the absence of increased serum insulin suggests their use in patients with noninsulin dependent diabetes mellitus (NIDDM). With the aging of the United States population, an increase in the number of cases of NIDDM has been predicted. In the past forty years, very few new forms of therapy for this most prevalent disease have been developed. GIP antagonists enhance tolerance to oral glucose, as demonstrated herein, and therefore treatment of NIDDM patients with these compounds is indicated.
[0000] GIP Antagonists
[0032] A GIP antagonist according to this invention is any composition which interferes with biological action of GIP. Such compositions include antibodies specific for either GIP or GIP receptors, antisense RNA which hybridizes with mRNA encoding GIP or GIP receptor, or other genetic controls which knock out expression of GIP or GIP receptor. GIP antagonists also include peptides or other small molecules which bind to the GIP receptor and block the cAMP response to GIP. Suitable assays for antagonist activity are exemplified in Examples 1 and 2 below:
[0033] As described herein (see Example 1 below), the inventors have now discovered a polypeptide fragment of GIP that is a specific GIP receptor antagonist. While the 30-amino acid N-terminal fragment [GIP (1-3 0)-NH 2 ] was as effective in stimulating cAMP increase through GIP receptors as the parent hormone, a fragment missing the most N-terminal six amino acids [GIP (7-30)-NH 2 ] did not stimulate cAMP release in the same system. Thus, the N-terminal hexamer appears to be important for functional GIP signaling. GIP fragments missing the N-terminal 15 amino acids (e g., GIP (16-30)-NH 2 ) did not mimic GIP, but neither did they inhibit GIP-dependent effects. Thus, the segment from amino acids 7-15 appears to be especially important in signaling through the GIP receptor. Fragment GIP (10-30)-NH 2 was less effective as an antagonist, but retained some ability to affect GIP receptor activation, as indicated by partial agonist activity. Thus, peptide antagonists would appear to require the segment from amino acids 7-9 of the GIP sequence, and some or all of the amino acids from 10-30 or effective alternative amino acids thereto are likely to promote binding to the receptor. It should therefore be understood by those of skill in this art that the present invention contemplates any polypeptide sequence which effectively prevents GIP activation of its native receptor, such as the sequence containing amino acids in positions 7-30 of the sequence of the GIP sequence and polypeptides based upon sequences containing amino acids in positions 7-30 of the sequence of the GIP that include additional, deleted or alternative amino acids to form effective GIP polypeptide antagonist. Polypeptides based on this sequence may be designed for use as GIP antagonists according to this invention by the skilled artisan, who will routinely confirm that the resultant peptides exhibit antagonist function by testing the peptides in in vitro and in vivo assays such as those described in Examples 1 and 3-5 below.
[0034] Immunologic components specific for GIP or GIP receptors can be employed as GIP antagonists. Such antagonists include with specific monoclonal antibodies (either naked or conjugated to cytotoxic agents) or specific activated cytotoxic immune cells. Such antibodies or immune cells may be generated as reagents outside the body, or may be generated inside the body by vaccines which target GIP or GIP receptors.
[0035] Antibodies which are specifically reactive with GiE or the hormone binding domain of GIP receptor, or antigenic recombinant peptide fragments of either of those proteins, may be obtained in a number of ways which will be readily apparent to those skilled in the art. The known sequences of GIP (see Takeda, et al. 1987 , Proc. Nat. Acad. Sci USA , B84:7005-7008, and Genbank Accession No. M18185), and GIP receptor (see Bonner, T. I., and Usdin, T. B., 1995, Genbank Accession No U3923 1) can be used in conjunction with standard recombinant DNA technology to produce the desired antigenic peptides in recombinant systems (see, e.g., Sanbrobk et al.). Antigenic fragments of GIP or GIP receptor can be injected into an animal as a immunogen to elicit polyclonal antibody production. Purification of the antibodies can be accomplished by selective binding from the serum, for instance by using cells transformed with DNA sequence encoding the respective proteins. The resultant polyclonal antisera may be used directly or may be purified by, for example, affinity absorption using recombinantly produced protein coupled to an insoluble support.
[0036] In another alternative, monoclonal antibodies specifically immunoreactive with either GIP or the hormone binding domain of GIP receptor may be prepared according to well known methods (See, e.g., Kohler and Milstein, 1976 , Eur. J. Immunol., 6:611), using the proteins or antigenic fragments described above as immunogen(s), using them for selection or using them for both functions. These and other methods for preparing antibodies or immune cells that are specifically immunoreactive with GIP or GIP receptor are easily within the skill of the ordinary worker in the art.
[0037] Immunogenic compositions according to this invention for use in active immunotherapy include recombinant antigenic fragments of GIP or GIP receptor prepared as described above and expression vectors (particularly recombinant viral vectors) which express antigenic fragments of GIP or GIP receptor. Such expression vectors can be prepared as described in Baschang, et al., U.S. Pat. No. 4,446,128, incorporated herein by reference, or Axel, et al., Pastan, et al., or Davis, et al., using the known sequences of GIP or GIP receptor.
[0038] Still another GIP antagonist according to this invention is an expression vector containing an antisense sequence corresponding to all or part of an MRNA sequence encoding GIP or GIP receptor, inserted in opposite orientation into the vector after a promoter. As a result, the inserted DNA will be transcribed to produce an RNA which is complementary to and capable of binding or hybridizing to the mRNA. Upon binding to the GIP or GIP receptor rnRNA, translation of the mRNA is prevented, and consequently the protein coded for by the mRNA is not produced. Suitable antisense sequences can be readily selected by the skilled artisan from the sequences of GIP or GIP receptor cited above. Production and use of antisense expression vectors is described in more detail in U.S. Pat. No. 5,107,065 and U.S. Pat. No. 5,190,931, both of which are incorporated herein by reference.
[0039] Alternative materials within the contemplation of the skilled artisan which function as antagonists of GIP in the procedures described in Examples 1 and 3-5 below may also be used in the therapeutic methods according to this invention.
[0000] Therapeutic use of GIP Antagonists
[0040] GIP (7-30)-NH 2 acts as a receptor antagonist of GIP, but also improves glucose tolerance contrary to the expected consequence of blocking GIP-dependent insulin secretion. In addition, a GIP receptor antagonist in accordance with the present invention inhibits, blocks or reduces glucose absorption from the intestine of an animal. In accordance with this observation, therapeutic compositions containing GIP antagonists may be used in patients with noninsulin dependent diabetes mellitus (NIDDM) to improve tolerance to oral glucose or in animals, such as humans, to prevent, inhibit or reduce obesity by inhibiting, blocking or reducing glucose absorption from the intestine of the animal, as demonstrated herein.
[0041] Therapeutic compositions according to this invention are preferably formulated in pharmaceutical compositions containing one or more GIP antagonists and a pharmaceutically acceptable carrier. The pharmaceutical composition may contain other components so long as the other components do not reduce the effectiveness of the GIP antagonist according to this invention so much that the therapy is negated. Examples of such components include sweetening, flavoring, coloring, dispersing, disintegrating, binding, granulating, suspending, wetting, preservative and demulcent agents and the like. Pharmaceutically acceptable carriers are well known, and one skilled in the pharmaceutical art can easily select carriers suitable for particular-routes for administration ( Remington's Pharmaceutical Sciences , Mack Publishing Co., Easton, Pa., 1985).
[0042] Also in accordance with the present invention, the GIP receptor antagonist of the present invention may be lyophilized using standard techniques known to those in this art. The lyophilized GIP receptor antagonists may then be reconstituted with, for example, suitable diluents such as normal saline, sterile water, glacial acetic acid, sodium acetate, combinations thereof and the like. The reconstituted GIP receptor antagonists in accordance with the present invention may be administered parenterally or orally and may further include preservatives or other acceptable inert components as mentioned hereinbefore.
[0043] The pharmaceutical compositions containing any of the GIP antagonists according to this invention may be administered by parenteral (subcutaneously, intramuscularly, intravenously, intraperitoneally, intrapleurally, intravesicularly or intrathecally, topical, oral, rectal, or nasal route, as necessitated by choice of drug and disease. The dose used in a particular formulation or application will be determined by the requirements of the particular state of disease and the constraints imposed by the characteristics of capacities of the carrier materials. The concentrations of the active agent in pharmaceutically acceptable carriers may range from 0.1 nM to 100 μM. The compositions described above may be combined or used together or in coordination with another therapeutic substance.
[0044] Dose will depend on a variety of factors, including the therapeutic index of the drugs, disease type, patient age, patient weight, and tolerance of toxicity. Dose will generally be chosen to achieve serum concentrations fro about 0.1 μg/ml to about 100 μg/ml. Preferably, initial dose levels will be selected based on their ability to achieve ambient concentrations shown to be effective in in-vitro models, such as that used to determine therapeutic index, and in-vivo models and in clinical trials, up to maximum tolerated levels. Standard clinical procedure prefers that chemotherapy be tailored to the individual patient and the sytemic concentration of the chemotherapeutic agent be monitored regularly. The dose of a particular patient can be determined by the skilled clinician using standard pharmacological approaches in view of the above factors. The response to treatment may be monitored by analysis of blood or body fluid levels of the glucose or GIP or GIP antagonist according to this invention, measurement of activity if the antagonist or its levels in relevant tissues or monitoring disease state of the patient. The skilled clinician will adjust the dose based on the response to treatment revealed by these measurements.
[0045] One approach to therapy ofNIDDM is to introduce vector expressing antisense sequences to block expression of GIP and/or GIP receptor. In one embodiment of this invention, a method is provided which comprises obtaining a DNA expression vector containing a cDNA sequence having the sequence of human GIP or GIP receptor MRNA which is operably linked to a promoter such that it will be expressed in antisense orientation, and trarisforming cells which express GIP or GIP receptor, respectively, with the DNA vector. The expression vector material is generally produced by culture of recombinant or transfected cells and formulated.in a pharmacologically acceptable solution or suspension, which is usually a physiologically-compatible aqueous solution, or in coated tablets, tablets, capsules, suppositories, inhalation aerosols, or ampules, as described in the art, for example in U.S. Pat. No. 4,446,128, incorporated herein by reference.
[0046] The vector-containing composition is administered to a mammal exhibiting NIDDM in an amount sufficient to transect a substantial portion of the target cells of the mammal. Administration may be any suitable route, including oral, rectal, intranasal or by intravesicular (e.g. bladder) instillation or injection where injection may be, for example, transdermal, subcutaneous, intramuscular in intravenous. Preferably, the expression vector is administered to the mammal so that the target cells of the mammal are preferentially transfected. Determination of the amount to be administered will involve consideration of infectivity of the vector, transection efficiency in vitro, immune response of the patient, etc. A typical initial dose for administration would be 10-1000 micrograms when administered intravenously, intramuscularly, subcutaneously, intravesicularly, or in inhalation aerosol, 100 to 1000 micrograms by mouth, 10 5 to 10 10 plaque forming units of a recombinant vector, although this amount may be adjusted by a clinician doing the administration as commonly occurs in the administration of other pharmacological agents. A single administration may usually-be sufficient to produce a therapeutic effect, but multiple administrations may be necessary to assure continued response over a substantial period of time.
[0047] Further description of suitable methods of formulation and administration according to this invention may be found in U.S. Pat. Nos. 4,592,002 and 4,920,209, which are incorporated herein by reference in their entireties.
[0048] The present invention also contemplates the use of the GIP antagonists and/or its properties to develop nonpeptide compounds which exhibit antagonist properties similar to the GIP polypeptide antagonists as herein described using techniques known those versed in the pharmaceutical industry.
EXAMPLES
[0049] In order to facilitate a more complete understanding of the invention, a number of Examples are provided below. However, the scope of the invention is not limited to specific embodiments disclosed in these Examples, which are for purposes of illustration only.
Example 1
Effects of Various Peptide Fragments on cAMP Production
[0050] To define the biologically active region of GIP, the effects of several peptide fragments of GIP on stimulating cAMP-dependent βgalactosidase production in LGIPR2 cells were examined. LGIPR2 cells are stably transfected with a cAMP-dependent promoter from the VIP gene fused to the bacterial lac Z gene. When intracellular cAMP increases within these cells, lac Z gene transcription is activated, resulting in the accumulation of its product, β-galactosidase. The measurement of β-galactosidase in this system provided a convenient, inexpensive, and nonradioactive method for detecting changes in the levels of intracellular cAMP.
[0051] LGIPR2 cells were grown in Dulbecco's Modified Eagle's Medium (DMEM) containing 4.5 g/L of glucose and 10% fetal calf serum. For each assay, 10 5 cells/well were seeded onto 24-well plates. After incubation overnight, peptides were added in various concentrations to the wells in the absence of 3-isobutyl-methylxanthine (IBMX) for 4 h, at which time maximal stimulation of β-galactosidase was determined. The medium was then removed and wells rinsed once with phosphate-buffered saline (PBS). The plates were then blotted briefly and frozen overnight at −70° C., and, after the addition of chlorophenol red-β-D-galactopyranoside, accumulated β-galactosidase was detected using a colorimetric assay, as described previously (Usdin, et al., 1993 , Endocrinology, 133:2861-2870).
[0052] Preliminary studies using LGIPR2 cells demonstrated that GIP(1-42) stimulated β-galactosidase production in a concentration-dependent manner, with the maximum effect observed at 4 h with 10 8 M. Various peptide fragments of GIP, including GIP(21-30)NH 2 , GIP (16-30)-NH 2 , GIP (7-30)-NH 2 , GIP (1-30)-NH 2 , GIP (10-30)-NH 2 , and GIP (31-44), were synthesized at the Biopolymer Laboratory, Harvard Medical School, based on previously published rat GIP cDNA sequence (Tseng, et al., 1993 , Proc. Natl. Acad Sci. USA, 90:1992-1996). LGIEPR2 cells were incubated in the presence of 10 8 M GIP or different GIP fragments for 4 h, and β-galactosidase was measured as described herein and expressed in optical density (O.D.) units. FIG. 1A and 1B show cyclic AMP-dependent β-galactosidase generation in LGIPR2 cells in response to incubation with different fragments of GIP. Values are expressed as the mean±SE of quadruplicate measurements (*p<0.01, compared to control).
[0053] As demonstrated in FIG. 1A , 10 8 M GIP (1-30)-NH 2 stimulated β-galactosidase production to a similar degree, while none of the other peptide fragments tested, including GIP (7-30)-NH 2 , GIP (16-30)-NH 2 , GIP (21-30)-NH 2 , and GIP (31-44), stimulated β-galactosidase generation above control levels. Furthermore, no changes in cAMP-dependent-β-galactosidase levels were detected when LGIPR2 cells were incubated in the presence of higher concentrations of the smaller peptide fragments.
[0054] To examine whether any of these fragments might serve as an antagonist to GIP, LGIPR2 cells were incubated with 10 8 M GIP (1-42) and one of the peptide fragments at two different concentrations (10 8 M or 10 6 M ) for 4 h. LGIPR2 cells were cultured in the presence of 10 8 M GIP and various concentrations of ANTGIP, as depicted on the horizontal axis if FIG. 2 . Values are expressed as the mean±SE of quadruplicate measurements. Only GIP (7-30)-NH 2 (ANTGIP) was found to attenuate the cAMP stimulatory effects exhibited by GIP (1-42); the inhibition was concentration-dependent, with half-maximal inhibition occurring at 10 7 M ( FIG. 2 ).
[0055] FIG. 1B shows that peptide GIP (10-30)-NH 2 is an antagonist, albeit a weak one, as demonstrated by the reduction in GIP-stimulated β-gal levels when GIP (10-3 0)-NH 2 is present with GIP (1-42) compared to GIP (1-42) alone. On the other hand, GIP (10-30)-NH 2 also has agonist properties, as demonstrated by β-gal level of 0.39 O.D. ±0.03 stimulated by GIP (10-30)-NH 2 alone, compared to 0.95±0.04 for GIP (1-42).
Example 2
Receptor Binding Studies
[0056] Binding studies were performed in either LGIPR2 or βTC3 cells to determine the relative affinities of GIP, ANTGIP, and GLP-1 for both GIP and GLP-1 receptors. GLP(7-37) and porcine GIP (5 μg each) were iodinated by the chloramine-T method and were purified using C-18 cartridges (Sep-Pak®, Millipore, Milford, Mass.) using an acetonitrile gradient of 30-45%. The specific activity of radiolabeled peptides was 10-50 μCi/mg (Hunter, et al., 1962 , Nature, 194:495-498; Kieffer, et al., 1993 , Can. J. Physiol Pharmacol., 71:917-922). Aliquots were lyophilized and reconstituted-in assay buffer at 4° C. to a concentration of 3×10 5 cpm/100 μl. Binding studies was performed in desegrated LGIPR2 or βTC2 cells, the latter a generous gift from Dr. S. Efrat (Diabetes Center, Albert Einstein College of Medicine, New York). The βTC2 cell line originally arose in a lineage of transgenic mice expressing an insulin promoted, SV40 T-antigen hybrid oncogene in pancreatic β-cells (Efrat, et al., 1988 , Proc. Natl. Acad. Sci. U.S.A., 85:9037-9041) and has previously been demonstrated to be responsive to both GIP and GLP (Kieffer, et al.; 1993 , Can. J. Physiol. Pharmacol., 71:917-922). The receptor binding buffer contained 138 mM NaCl, 5.6 mM KCl, 1.2 mM MgCl 2 , 2.6 mM CaCl 2 , 10 mM Hepes, 10 mM glucose, and 1% bovine serum albumin (BSA, fraction V, protease free, Sigma). For binding assays, LGIPR2 (GIP binding) or βTC3 (GLP-1 binding) cells were cultured in DMEM containing 4.5 g/L of glucose and 10% fetal bovine serum until 70% confluent. Cells were washed once with PBS and then harvested with PBS-EDTA solution. βTC3 cells were then suspended in assay buffer at a density of 2×10 6 cells/ml, and LGIPR2 cells were used at a density of 2.5×10 5 cells/ml. Binding was performed at room temperature in the presence of 3×10 5 cpm/ml of [ 125 I]-GIP and -GLP. Nonsaturable binding was determined by the amount of radioactivity associated with cells when incubated in the presence of unlabeled 10 6 M GIP, GLP, or 10 4 M ANTGIP. Specific binding was defined as the difference between counts in the absence and presehce of unlabeled peptide. GIP binding was examined using LGIRP2 cells, and GLP-1 binding was assessed using βTC3 cells, and the results are shown in FIG. 3 . Values are expressed as a percentage of maximum specific binding and are the mean±SE, with assays performed in duplicate.
[0057] GIP and ANTGIP displaced the binding of [ 125 ] GIP to LGIPR2 cells in a concentration-dependent manner ( FIG. 3 ), with an IC 50 of 7 nM for GIP (n=5) and 200 nM for ANTGIP (n=4). Binding of [ 125 I]GLP-1 to its βTC3 cell receptor was displaced fully by GLP-1, but negligibly by ANTGIP, with an IC 50 of 4 nM and 80 μM, respectively (n=7; FIG. 3 ).
Example 3
Intravenous Infusion of Peptides in Fasting Anesthetized Rats
[0058] Adult male Sprague-Dawley rats (250-350 g) were purchased from Charles River Co. (Kingston, Mass.). For infusion studies, rats were fasted overnight and then anesthetized using intraperitoneal sodium pentobarbital. The right jugular vein was cannulated with silicon polymer. tubing (0.025 in I.D., 0.047 in O. D., Dow Corning Corporation, Midland, Mich.), as described by Xu and Melethil (21). The tubing was then connected to an infusion pump (Harvard Apparatus Co., Inc., Millis, Mass.), and freshly made 0.9% NaCl, 5% glucose, arginine, GIP, or GLP-1 (peptides and arginine dissolved in 0.9% NaCl) was infused at a rate of 0.1 ml/min. Blood (0.5 ml each) was obtained at 0, 10, 20, and 30 min by translumbar vena cava puncture, as described by Wmsett et al. (1985 , Am. J. Physiol, 249:G145-146), and samples were centrifuged at 2,000 g for 10 min. Serum samples were separated and stored at −20° C. until assayed for insulin using a radioimmunoassay kit (ICN Biochemicals, Costa Mesa, Calif.), and glucose, using a One Touch Iiβ glucose meter (Lifescan, INS., Milpitas, Calif.).
[0059] To examine the insuotropic effect of GIP in vivo, fasted anesthetized rats were perfuised continuously with three different concentrations of GIP (0.5, 1.0, and 1.5 nmol/kg) at a rate of 0.1 ml/min for 30 min (10 8 M equivalent to 1 nmol/kg/30 min). Significant increases in plasma insulin levels were first detected at 15 min. and after completion of the GIP infusion, insulin levels were elevated with all three GIP concentrations (43.5±2.7, 61.6±4.2, and 72.4±3.5 μIU/ml, respectively) compared to control (32.2±3.3 μIU/m, p<0.05, FIG. 4 ). The concomitant administration of ANTGIP (100 nmol/kg) completely abolished the insulinotropic properties of GIP (1.5 nmol/kg), with plasma insulin returning to control values ( FIG. 4 ). GIP was infused at 0.5, 1.0, and 1.5 nmol/kg, with the largest insulin stimulatory response seen with 1.5 nmol/kg. ANTGIP (100 nmol/kg) administered concomitantly with GIP 1.5 nmol/kg completely abolished its insulinotropic effect, whereas ANTGIP and 0.9% NaCl infusion had no effect on insulin secretion (n=6 for each group, *p<0.05, compared with basal levels).
[0060] To examine whether ANTGIP exerted a nonspecific effect on β-cell function, GLP-1 (0.4 nmol/kg), glucose (0.8 g/kg), or arginine (375 mg/kg) was infused, in the presence or absence of the antagonist for 30 min, as described by Wang et al. (13). FIG. 5 shows plasma insulin concentrations (±SE) in fasted anesthetized rats after a 30-min infusion of GLP-1 (0.4 nmol/kg), glucose (0.8 g/kg), or arginine (375 mg/kg) with (open bars) or without (solid bars) ANTGIP (100 nmol per kg) (n=6 for each group, *p<0.05, compared with basal levels). GLP-1, glucose, and arginine alone each significantly increased insulin levels after 15 min of infusion, and by 30 min, the insulin levels in GLP-1-, glucose-, and arginine-infused rats were 50.3±3.7, 63.1±2.5, 69.7±5.8 μIU/ml respectively (p<0.01, compared with control rats, 29.1±2.9 μIU/ml, FIG. 5 ). No significant change in the insulin response was detected when ANTGIP was administered concomitantly ( FIG. 5 ).
Example 4
Insulinotropic Effect of GIP in Trained Conscious Fed Rats
[0061] Postprandial plasma insulin and serum glucose levels were studied in conscious trained rats. Previous reports have indicated that the stress response to injection in untrained rats might alter their feeding and subsequently glucose and insulin levels (13). To avoid such a response, rats were trained for 10 d before experimentation. They were fasted from 17:00 to 08:00, and 0.9% NaCl (0.3 ml) was injected subcutaneously at 08:00 before feeding. After the injection of 0.9% NaCl, animals were given rat chow for 30 min, after which it was removed. At the end of ten days, the rats were accustomed to the injection and ate quickly (consuming 4-6 g of rat chow within 30 min).
[0062] On the day of the experiment, after fasting from 17:00 the night before, trained rats were injected subcutaneously at 08:00 with 0.3 ml of either 0.9% NaCl or ANTGIP (100 nmol/kg). This dose was chosen to approximately the amount of peptide used in the anesthetized animal studies of Example 3. After injection, six of the fasted control rats were killed to obtain baseline serum glucose and insulin levels. ANTGIP- or 0.9% NaCl-treated rats (n=6 in each group) were exposed to chow for 30 min, after which food was withdrawn. Rats were then anesthetized by intraperitoneal sodium pentobarbital, and blood was collected by translumber vena cava puncture at 20 and 40 min for the subsequent measurement of plasma insulin, glucose, and GLP-1.
[0063] FIG. 6 shows postprandial plasma insulin and serum glucose levels (±SE) in conscious trained rats (* p<0.01 compared to ANTGIP injection). In response to consuming chow, serum glucose and plasma insulin levels increased significantly, with insulin levels of 38.7±5.3 and 58.9±3.7 μIU/ml at 20 and 40 min, respectively (p<0.05, FIG. 6A ). These increases in plasma insulin level were nearly abolished by ANTGIP pretreatment; at 20 and 40 min, the plasma insulin concentrations were 25.3±4.7 and 27.1±2.6 μIU/ml, respectively (p<0.01). Postprandial serum glucose concentrations were similar in both saline- and ANTGIP-treated rats ( FIG. 6B ). To determine whether the effects of the GIP receptor antagonist were mediated through changes in GLP-1 release into the circulation, postprandial serum GLP-1 levels were measured in both control and ANTGIP-treated animals. Meal-stimulated serum GLP-1 concentrations were not affected by ANTGIP administration. Following the ingestion of rat chow, serum GLP-1 levels at 20 min were 280±20 and 290±10 pg/ml in control and ANTGIP-treated rats, respectively; at 40 min, serum GLP-1 concentrations were 320±10 and 330±20 pg/mgl, respectively.
Example 5
Effect of ANTGIP on Glucose Tolerance and Plasma Insulin Levels
[0064] Oral glucose tolerance tests were performed on rats injected intraperitoneally with ANTGIP (300 ng/kg) or 0.9% saline solution. After the intraperitoneal injection of 0.9% NaCl or ANTGIP, an oral glucose tolerance test was performed. The test was done by administering a 40% glucose solution by oral gavage at a dose of 1 g per kg. The volume administered to each rat was approximately 0.5 ml. Blood was obtained at various time points for subsequent measurement of plasma insulin and glucose levels.
[0065] As expected in view of the experiment in Example 4, rats treated with ANTGIP showed reduced the plasma insulin levels ( FIG. 7 ). Surprisingly, plasma glucose was diminished at all time points in rats treated with ANTGIP, compared to control rats ( FIG. 8 ). Thus, ANTGIP increases glucose tolerance, despite its negative effect on the insulinotropic response to GIP shown in Examples 3 and 4.
Example 6
Effect of GIP Receptor Antagonist on Intestinal Glucose Absorption
[0066] Male Sprague-Dawley rats weighing about 200-250 g are fasted overnight and anesthetized using intraperitoneai urethane (about 1.25 g per kg body weight). After midline laparotomy, an about 30-cm segment of jejunum, starting at about 5 cm distal to the ligament of Treitz, is isolated and flushed with approximately 20 ml of about 0.9% NaCl. The jejunal test segments are each perfused twice, initially with control buffer and then once again with control buffer or with the test solution. The test solution consists of Krebs-Ringer-bicarbonate buffer containing about 5 mmol/L [ −14 C]D-glucose, and 3 H-labeled polyethylene glycol is included in the luminal perfiisate to correct for fluid movement. The test or control solution is perfused through the jejunal segment without recirculation at a flow rate of about 1.6 mlumin, using a Harvard PHD 2000 syringe pump (Harvard Apparatus, Millis, Mass.). The effluent from the luminal segment is collected at about 5-min intervals for about 30 min. After the initial period of perfusion, the luminal contents in the jejunum are flushed with about 20 ml of about 0.9% NaCl prior to the initiation of the second period of perfusion. In all experiments, animals are administered either about 0.9% NaCl (control) or ANTGIP (10 nmol/kg body weight) though the inferior vena cava by single injection at about time 0 min.
[0067] The enclosed FIG. 9 depicts the effects of the GIP receptor antagonist, ANTGIP, on the absorption of free D-glucose from the lumen of the jejunal test segment. Data points are believed to represent the rate of glucose disappearance from the luminal perfusate corrected for fluid movement. Results are expressed as the mean±SE of five experiments. Statistical significance (*) is assigned if P<0.05. As seen in the figure, a ANTGIP is believed to significantly reduce the absorption of D-glucose from the jejunal test segment throughout the entire 30-mini period of perfusion. Thus, it is believed that one of the mechanisms by which GIP receptor antagonism may improve glucose tolerance is by decreasing intestinal glucose absorption.
[0068] For purposes of clarity of understanding, the foregoing invention has been described in some detail by way of illustration and example in conjunction with specific embodiments, although other aspects, advantages and modifications will be apparent to those skilled in the art to which the invention pertains. The foregoing description and examples are intended to illustrate, but not limit the scope of the invention. Modifications of the above-described modes for carrying out the invention that are apparent to persons of skill in medicine, molecular biology, pharmacology, and/or related fields are intended to be within the scope of the invention, which is limited only by the appended claims.
[0069] All publications and patent applications mentioned in this specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference in their entireties to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. | In one embodiment, this invention provides an antagonist of glucose-dependent insulinotropic polypeptide (GIP) consisting essentially of a 24 amino acid polypeptide corresponding to positions 7-30 of the sequence of GIP. In another embodiment, this invention provides a method of preventing and treating obesity and non-insulin dependent diabetes mellitus (Type II) in a patient comprising administering to the patient an antagonist of glucose-dependent insulinotropic polypeptide (GIP). In yet another embodiment, this invention provides a method of improving glucose tolerance in a mammal comprising administering to the mammal an antagonist of glucose-dependent insulinotropic polypeptide (GIP). | 2 |
This invention relates to a control circuit for an electric clothes dryer which normally employs dual electric heating elements for heating the air which is subsequently drawn through the rotating drum of the dryer. The usual control for electric clothes dryers uses a number of temperature sensitive devices mounted in strategic places in the air flow path to constantly monitor the temperature of the airstream at each strategic location, and when the switching temperature of the temperature sensing devices is reached the flow of electric energy to the dryer heater is interrupted. Usually, during this time, the drum continues to rotate and the air blower continues to draw air through the dryer until the temperature of the air drops sufficiently to cause the temperature sensing device which previously opened, to close and re-energize the dryer heater to again begin the air heating cycle over again. Most of the present day dryers include an automatic cycle which is designed to terminate the cycle automatically when the clothes are dried in the automatic cycle. During the time that the energy to the heater is interrupted, it is not unusual to have a dryer timing device advance toward the end of its timing cycle. This process is repeated again and again each time that the temperature sensor is activated with the end result being that as the clothes in the dryer drum are approaching the desired degree of dryness and the timing device is approaching its final time out and shut down of the dryer occurs just as the clothes have reached the desired degree of "dryness". (One of the temperature sensors which has a temperature operating point substantially above the others serves as a safety device and once this particular sensor trips, the operation of the dryer is terminated, even the blower motor is shut off.)
The above drying cycle has been incorporated by the manufacturers of domestic electric clothes dryers for the convenience of the operator. Some deviations in the operation of the control circuit are possible but the underlying philosophy of control remains the same, that is, the timer advances only when the flow of electric power to the dryer heater is interrupted; the timer motor serves to integrate those periods when power to the heater is interrupted and stop the drying process when a predetermined amount of time has elapsed. The operator is permitted to control the level of dryness by changing a control which increases or decreases the integrated time period that the timer motor must integrate before the drying process is stopped.
This method of control is to be differentiated from the method of control where the overall drying time is selected and set by the operator at the beginning of the drying operation and the timing device continuously operates to advance to the original predetermined timed setting whereupon the drying operation is terminated. This method of drying sees a constant, continuous advance in the timer mechanism during the drying operation, and the temperature sensing devices are continually sensing air temperature at various locations in the air stream and the interruption of the power to the dryer heater does not have any effect on the advance or stopping of the timing device in the dryer.
Thus it is the former method of control to which this invention is directed and this improvement is useful only with electric dryers equipped with a pair of heating elements, which may be separately energized. The invention will found to be most useful in dual element heater dryers in which some impediment to the air flow path is present, ie the exhaust ducting is partially obstructed, the lint filter is partially blocked or some other problem has arisen in the air stream which partially obstructs the normal air flow.
This invention seeks to improve the performance of such driers by interrupting the electricity flow to one of the heating elements, usually the outer coil, once a predetermined temperature at a preselected location in the dryer has been reached. During the time that the flow of electricity to the single element is interrupted, the other heating element of the pair continues to operate at full wattage so that heat is still added to the air stream, albeit at a reduced rate. However, the timing motor is prevented from advancing during this period because of the circuitry chosen to prevent such timing advancement under this reduced temperature drying condition.
Thus the dryer continues to operate although the heat introduced into the air passing through the dryer has been substantially reduced and the timer has not advanced. When the sensor which interrupted the electricity flow to the single element subsequently cools to its closing state, the de-energized heating element is again energized and again full heating wattage is applied to the combined elements thus adding the normal heat to the moving air stream and the process repeats until the temperature sensor at the outlet of the drum assumes control of the heating elements (this temperature sensor is usually used to control the drying process) and upon interruption of power to the dual elements by this sensor, the timing motor advances toward its ultimate end at which time the drying cycle is completed.
SUMMARY OF THE INVENTION
This invention relates to the power interruption of one of the heating elements of a dual element electric clothes dryer during a drying operation, the timing motor being held from advancing during this time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial perspective of an electric clothes dryer of this invention; and
FIG. 2 is a view of the diffuser showing the heating device of the dryer of FIG. 1;
FIG. 3 is an enlarged view showing the mounting of the thermostatic devices in the diffuser of FIG. 2; and
FIG. 4 is a circuit diagram utilized by this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and FIG. 1 in particular, a domestic clothes dryer 10 is shown.
Dryer 10 has a cabinet or housing 12 on which is mounted a control panel 14 which allows the user to select various drying modes and degrees of dryness of the clothes undergoing drying. Cabinet 12 has a door 16 mounted on the front panel to allow access to the drum 18. Drum 18 is mounted in cabinet 12 so as to allow for rotation therein.
Drum 18 is mounted within the cabinet 12 so that the rear of the drum 18 is substantially surrounded by a diffuser 20, shown in more detail in FIG. 2. The drum 18 is provided with a flat disc shaped member 22 at the rear thereof which contains a plurality of apertures such as 24 for the passage of drying air there through.
The diffuser 20 of the dryer 10 provides a convenient method of mounting a pair of electrical heating elements 26 and 28 on insulators mounted in the diffuser. These elements are standard heating elements and in the dryer illustrated, the elements in this instance being capable of separate electrical energization. The elements 26 and 28 pass through insulators such as those shown at 30 in the diffuser 20. The diffuser is made to mate with the revolving drum so that there is good communication between the drum and the diffuser for the hot air steam.
Three temperature sensors 32, 34 and 36 are shown mounted on the top of the diffuser 20. Two of these thermostats 32 and 34 are designed to open before the temperature of the air entering the clothes drum reaches a point that might damage the clothes being dried. The third temperature sensor 36 has a higher temperature rating and would be generally regarded as an ultimate safety device rather than a controlling device.
As previously stated, the thermostatic devices 32 and 34 will have operating characteristics and be mounted in a different manner on diffuser 20. Referring to FIG. 3, it will be seen that thermostat 34 is mounted in diffuser 20 in the usual manner with the temperature sensing head exposed completely to the airflow in the diffuser. Thermostat 32 on the other hand is somewhat shielded from the airflow in the diffuser by the fact that only part of the temperature sensing head is exposed to the atmosphere inside the diffuser. In this instance, a "strap" of the metal 38 from diffuser 20 remains beneath the thermostat 32 to shield the device and delay its reaction. Thus, under changing temperature conditions thermostat 32 will have a delayed reaction compared to thermostat 34.
It would also be possible to utilize two thermostats for operation of this invention whose temperature ratings are slightly different ie device 34 opening at say 190° F. and device 32 opening at 210° F. However for convenience in manufacturing it is simpler to use two thermostats of the same temperature operating characteristics. Not only do the devices cost less in quantity, but the problem of accidentally interchanging two devices of different ratings during manufacture is eliminated.
Two additional temperature sensors or thermostats are located at or near the front of the cabinet so as to sample the temperature of the air stream as it leaves the rotating drum. These are sensors 40 and 42 which essentially control the drying process. Temperature sensor 42 has a higher temperature activation than sensor 40.
A housing 44 is mounted so as to be in airflow communication with drum 20. A lint filter 45 is shown for trapping lint just as the air enters housing 44. Air is drawn from housing 44 into blower housing 46, the blower being driven by motor 47 and the air leaving blower 46 exits the dryer via pipe or duct 48.
The basic control circuit is shown in FIG. 4. Power is fed to the two terminals 50 and 52 designated as L 1 and L 2 respectively. The neutral terminal is shown at 59. Terminal 50 is connected to one pole 56 of timer motor control switch 58 and to terminal 57 of timer motor control switch 59. The other pole 60 of switch 58 is connected to terminal 64, of start switch 66. The other pole 62 of timer switch 59 is connected to terminal 70. Terminal 70 is connected to timer motor 72 and pole 74 of thermostat 32. The other pole 76 of thermostat 32 is connected to pole 78 of thermostat 42. The other pole of thermostat 42 is connected to pole 80 of thermostat 40 and pole 84 of switch 86. Pole 88 of switch 86 is connected to pole 90 of thermostat 34 and pole 92 of thermostat 34 is connected to one side of outer heating coil 94.
The other pole 82 of thermostat 40 is connected to pole 96 of switch 98 and terminal 154 of switch 152. Pole 100 of switch 98 is connected to one side of resistor 102, and to one end of inner heating coil 104. Pole 150 of switch 152 is connected to terminal 88 of switch 86 and terminal 90 of thermostat 34.
Heating coils 94 and 104 are connected to one pole 108 of centrifugal switch 110. The other pole 112 of switch 110 is connected to terminal 52 of L 2 .
Timer motor 72 is connected to resistor 102 and terminal 142 of switch 140. Terminal 144 of switch 140 is connected to the neutral terminal 59.
Pole 68 of start switch 66 is connected to pole 116 of centrifugal switch 110 which in turn is connected to "run" winding 118 of the blower motor 44 shown in FIG. 1. The other end of run winding 118 is connected to terminal 114 which is connected to terminal 54 of switch 57.
Pole 64 of start switch 66 is connected to pole 120 of high limit thermostat 36 (located on the diffuser). Pole 122 of thermostat 36 is connected to pole 124 of centrifugal switch 110. The blade 126 of centrifugal switch 110 is shown in its "start" position, ie bridging poles 116 and 128. Pole 128 is connected to "start" winding 130 of motor 47. The other end of start winding 130 is connected to terminal 114 which is connected to terminal 54 of door switch 57. The other terminal 55 of door switch 57 is connected to neutral terminal 59.
Basically the circuit functions as follows:
Control timer is set by the operator to a setting calculated to give a predetermined desired degree of "dryness" to the clothes in dryer drum 18 at the end of the drying cycle. The other variable set by the operator is the type of fabrics, whether "Wash and Wear" or "Regular Drying" is desired. This is accomplished by means of switches 86 and 98 and 152 (which are coupled) and in the circuit shown in FIG. 4 control will resort to thermostat 40 which has the lower temperature operating point (as compared to the other control thermostat 42).
With the control timer 58 and 59 set, contacts 56 and 60 plus contact 57 and 62 are closed, and control temperature selected, the operator depresses the "start" button on switch 66 and the windings 118 and 130 are energized and motor 47 begins to run. As the motor gains speed centrifugal switch 110 snaps to the alternate state closing contacts 116, 124 and 108 and 112. The operator may now allow the start switch 66 to return to its unbridged position opening contacts 64 and 68. Run winding 118 is now energized through high temperature thermostat 36 and switch blade 126 of switch 110.
Similarly, current for the two heating elements is supplied via control timer, switch 59, safety thermostat 32, (located on diffuser) high temperature drum outlet temperature sensor 42, low temperature drum outlet temperature sensor 40, switch 98 and to coil 104 also from sensor 42 to switch 86, sensor 34 to coil 94. It will be noted that thermostat 34 carries current from switch 86 to coil 94, and this thermostat which would not be present in the prior art driers, forms the basis for this invention. Thermostats 32 and 34 are located quite close to each other on the diffuser and their characteristics are chosen to be identical but thermostat 32 is shielded and requires a longer time period to respond than does thermostat 34.
The timer motor will not advance as long as the heater 104 is energized because resistor 102 maintains a potential of L 1 on terminal 103.
As the clothes begin to dry, the temperature of the air exiting the drum begins to increase and thermostat 42 controls the energization of coils 94 and 104. As the temperature of the air exiting the drum increases (indicating that the clothes are drying), the thermostat 40 opens but when normal (high) drying temperature has been chosen by operator, switch 86 and 152 will keep passing current to both heater coils 94 and 104. As temperature of air exiting the drum keeps increasing to the point where sensor 42 opens and stops current flow to both coils, the potential at terminal 103 approaches that of L 2 and timer motor 72 beings to advance the timer.
When the air exiting the drum cools somewhat, thermostat 42 closes and the advance of the timer ceases and the coils 94 and 104 are energized again. This cycle repeats until the timer times out and switch 59 opens then current flow to heater coils ceases and timer motor runs continuously to the point where switch 58 opens. At that point, main motor 47 stops and the dryer stops.
If thermostat 34 is omitted from the circuit as in prior art models, assuming terminals 90 and 92 are permanently bridged, if an obstruction occurs in the air flow path, the temperature in the diffuser increases and the thermostat 32 (which in prior art devices would be unshielded) opens (insufficient hot air arriving at thermostat 40 to cause it to open) and timer 72 advances and the clothes in the drum are not drying because of the obstruction in the air stream. If the obstruction is continuous, and thermostat 32 continues to open and close, the clothes are not being dried, but the timer is advancing each time thermostat 32 opens. The end result is that the timer eventually times out and the clothes in the drum are still wet, because the timer was advancing because the diffuser was subjected to overheat and thermostat 32 kept opening and closing.
In order to overcome this deficiency, thermostat 34 will provide a solution. Thermostat 34 is mounted in diffuser in the same general location as thermostat 32, but is more temperature sensitive because of the absence of shield 38. If in the presence of an obstruction in the air flow stream in the dryer or in the exhaust ducting, connected to the dryer 10, when overheating occurs in the diffuser 20, thermostat 34 will open before thermostat 32, disconnecting the outer heating coil 94 from terminal 50 of L 1 allowing only about half the previous heat to be added to the drum 18 and diffuser 20. During this time, reduced wattage allows the drying operation to continue, and the timer is not allowed to advance because terminal 103 is maintained at the potential of L 1 . Thus the thermostat 34 continues to cycle on and off until the clothes begin to dry at which time the air leaving the drum begins to heat up and the thermostat 42 begins to assume control as the temperature of the air leaving the drum rises to a level to cause thermostat 42 to open. When thermostat 42 opens, the timer begins to advance to the end of its cycle.
When thermostat 42 assumes control, it will be found that thermostat 34 may continue to cycle depending on the temperature rise in the diffuser 20. However, the timer 72 will only advance when any of the thermostats 32 or 42 open. All of these thermostats only serve to interrupt the power to the dryer heating elements 94 and 104; they do not halt operation of the dryer, thermostat 36 which is a safely device of a high temperature rating serves to stop the entire dryer operation should its contacts open.
Thus, it will be seen that when an obstruction occurs in the air flow path of the clothes dryer that the temperature in the diffuser increases because the heat generated by the dryer heating elements is not being transferred to the damp or wet clothes in the drum. In prior art circuits, the thermostat in the diffuser region would be designed to interrupt the total power to heating elements and the timer would advance to its time out. Meanwhile, the degree of moisture removal from the set clothes in the drum was insignificant.
This invention keeps up the drying operation, albeit at a reduced rate while such problems exist, and the timer advance is held in abeyance while the partial energization of the dryer heating elements occurs.
If the obstruction in air flow is too high, even if sensor 34 opens and lets only one coil heating, the temperature could still keep increasing in diffuser to the point where sensor 32 would open. The timer motor would then advance to the off position. Sensor 32 and 34 are calibrated so that this condition would only happen in very high air flow restrictions and at these restrictions, it is acceptable to stop with wet clothes. It is hoped that then the operator will notice the problem and inspect and correct air blockage.
Various alternatives will be obvious to those skilled in the art, but applicant wishes to be limited only the scope of the following claims. | This invention relates to a clothes dryer which can successfully cope with operation when the air circulation path is partially blocked. The dryer is of a type having dual heating elements and during conditions where blocking exists, the heat generation is reduced by disconnecting one of the heating elements while air is circulated thru the dryer. | 3 |
TECHNICAL FIELD
The present invention relates to apparatus for supporting a ladder when in use.
In use ladders are often arranged to lean against a wall or other part of a structure such as a building. This arrangement can often lead to situations where the user is put at risk through the danger of the ladder falling.
The present invention seeks to ameliorate the abovementioned disadvantage.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided a ladder support apparatus, the apparatus including a support body, one or more clamp mechanisms operatively mountable to the support body, for mounting the support body to a structure and a retention assembly operatively connected to the support body and, in use, being adapted to limit relative movement between the ladder and ladder support, the or each clamping mechanism including a clamp arm mounted for movement relative to the support body in a clamping direction and a release direction, an actuator operable to control the operation of the clamp arm, the clamp mechanism being arranged so as to be able to adopt a preset mode in which the clamp arm is substantially freely moveable in both the clamping direction and the release direction, a set mode in which the clamp arm is inhibited from movement in either direction but can be moved incrementally by operation of the actuator and a pre-release mode in which the clamp arm is inhibited from movement in either direction but upon operation of the actuator when in the pre-release mode the clamp arm can return to its preset mode.
The retention assembly may include two ladder retention devices each adapted for association with a respective ladder stile each device including a bracket which is operatively connected to the support body and includes a plurality of guides arranged in spaced apart relation for receiving the ladder stile with which it is associated therebetween, the guides being arranged to enable relative movement between the ladder and the retention devices in the direction of the stiles but inhibiting relative lateral movement. Preferably the position of the guides is adjustable relative to one another. Preferably each clamp arm is mounted for relative linear movement with respect to the support body towards the support body in the clamping direction and away from the support body in the release position.
Each clamping mechanism includes a braking device which can provide resistance to the movement of the clamp arm. A control arm may be provided which is operable to engage the braking bar towards the braking bar into a non-braking position. In one form the actuator comprises a lever pivotally mounted so that pivotal movement thereof can cause the clamping mechanism to operate in its various modes.
A lift mechanism may be provided, attached to the support body for lifting the apparatus into a selected position on the ladder. The lift mechanism may be of any suitable form, however, in one preferred form the lift mechanism includes a flexible line such as a cable or rope operatively connected to the support body. A lift eye may be connected to the support body for the purpose of connecting the lift cable or rope.
A pulley may be provided to raise the support body, along the ladder. In a preferred form the line is passed once over an upper rung of the ladder and drawn upwards by pulling downward on an appropriate end of the line at a selected purchase such as for example a 1:1 purchase.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will hereinafter be described with reference to the accompanying drawings, and in those drawings:
FIG. 1 is a plan view of apparatus in accordance with one embodiment of the invention;
FIG. 2 is a detailed view of part of the apparatus shown in FIG. 1 ;
FIG. 3 is a schematic view of part of the apparatus shown in FIG. 1 ;
FIG. 4 is an end view of part of the apparatus shown in FIG. 3 ;
FIG. 5 is a schematic side elevation of apparatus according to one embodiment in one operating mode;
FIG. 6 is a schematic side elevation of the apparatus shown in FIG. 5 in another operating mode;
FIG. 7 is an end view of part of the apparatus;
FIG. 8 is a schematic side view of the apparatus shown in FIG. 6 in a mode of operation;
FIG. 9 is a schematic side view of the apparatus shown in another operational mode;
FIG. 10 is a schematic side view of the apparatus shown in another mode; and
FIG. 11 is a schematic side elevation of apparatus according to another embodiment in one operating mode;
FIG. 12 is a schematic side elevation of the apparatus shown in FIG. 1 in another operating mode;
FIG. 13 is a schematic side view of the apparatus shown in FIGS. 11 and 12 in a mode of operation;
FIG. 14 is an end view of the apparatus as shown in FIGS. 11 to 13 ;
FIG. 15 is a schematic side view of the apparatus shown in FIGS. 11 to 14 in another operational mode;
FIG. 16 is a schematic side elevation of apparatus according to yet another embodiment in one operating mode;
FIG. 17 is a schematic side elevation of the apparatus shown in FIG. 15 in another operating mode;
FIG. 18 is a schematic side view of the apparatus shown in FIGS. 15 and 16 in a mode of operation;
FIG. 19 is a schematic side view of the apparatus shown in another operational mode;
FIG. 20 is a schematic side elevation of apparatus according to yet another embodiment in one operating mode;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2 of the drawings there is shown a ladder support apparatus generally indicated at 10 . As illustrated in FIGS. 3 , 6 and 11 the apparatus is adapted to be mounted to a ladder 12 which includes a pair of spaced apart substantially parallel stiles 14 with spaced apart rungs 16 extending therebetween. The apparatus is adapted to be clamped to a structure such as gutter 60 ( FIG. 6 ), scaffold member 260 ( FIG. 11 ), or any other suitable structure. The apparatus is adapted to limit the movement of the ladder when mounted thereto.
The apparatus 10 includes a support body 20 in the form of an elongated structure which when the apparatus is mounted to a ladder extends in a direction from one stile to the other and generally parallel to the rungs.
As best illustrated in FIG. 2 the support body comprises a plurality of tubular components including outer sections 101 and 102 and inner sections 103 and 104 . Outer section 101 is smaller in length than section 102 and is adapted to support inner sections 103 and 104 which are arranged generally parallel to one another and in slightly spaced apart relation. Outer section 102 is adapted to receive inner sections 103 and 104 in telescopic fashion so that they can be slidably displaced therealong so as to provide for an adjustment of the length of the support body. The support body further includes a quick release locking device 105 which holds the sections in a fixed position relative to one another. The locking device 105 is adapted to cooperate with holes in the support body. A lifting link or eye 108 is provided to which a flexible line such as a rope or cord 109 can be attached. The lifting link 108 can be positioned in one of the holes 111 (only two are itemised) chosen so that the link is centrally disposed when the length of telescopic body is adjusted. Non-slip rubber pads 127 are provided in spaced apart relation along the body which inhibit damage to which the apparatus is to be clamped.
The apparatus further includes two ladder retention devices 110 each being adapted for association with a respective ladder stile. Each retention device 110 includes a bracket 112 which is secured to the support body. The devices 110 include guides 113 , 114 and 115 which in a mounted position limits movement of the ladder. Guides 113 and 114 includes rollers 116 and 117 and bearing plates 118 and 119 . Guide 115 is in the form of a boss 120 having a bearing plate 121 associated therewith. The guides enable the apparatus to move along the ladder in the direction of the stiles whilst limiting substantial lateral movement of the ladder. Guides 114 and 115 can be adjusted along slots 123 and 124 in order to cater for different ladders. Guide 113 can be mounted in one of holes 125 to provide suitable position adjustment.
The support body can be drawn upwards by a flexible line in the form of lift rope 109 which is connected to a lift eye 108 in the middle of the support body to ensure even pulling force to both devices.
In the embodiment of FIGS. 4 to 9 each device further includes a clamping mechanism 137 by which the apparatus can be releasably secured to a structure such as gutter 60 . In this embodiment the clamping device is adapted to be operated in a position remote from the apparatus when in use; that is the device can be operated from the ground or other surface upon which the ladder rests. The clamping mechanism 137 includes a clamp arm 138 in the form of a rod mounted to a support housing 171 on bracket 112 . The position of the support housing 171 relative to bracket 112 is clearly illustrated in FIG. 4 . The support housing 171 has mounting apertures 141 and 142 in opposed side walls thereof through which the clamp arm 138 can extend. The clamp arm 138 is slidably moveable relative to the housing 131 through the apertures 141 and 142 . The clamp arm 138 has a clamping stop 177 mounted at one end thereof and a stop 178 at its other end. Clamping stop 177 is mounted on arm 173 which is spring loaded and can be rotated relative to clamping arm 138 for positioning of a pin in one of a series of grooves 174 in section 175 of arm 173 (see FIG. 7 ).
The clamp mechanism includes a releasable braking device 182 which in a braking position provides resistance to movement of the clamp arm 138 relative to the housing 171 in at least one direction. The braking device includes a braking bar 183 having an aperture 184 therein through which the clamp arm 138 passes. The braking bar 183 can adopt a braking position in which withdrawal of the clamp arm 138 from the housing 171 is resisted.
Spring 185 tends to urge braking bar 183 into a braking position in which relative movement between the clamp arm 138 and the housing 171 is resisted. A control arm 187 is adapted to engage braking bar 183 under the influence of spring 188 to urge the braking bar into a non-braking position. The control arm 187 can be held by catch element 189 as described hereinafter.
There is further provided an adjustment device 186 which is operable to enable incremental movement of the clamp arm 138 so that the stop 177 is drawn towards the housing. The adjustment device includes an actuating lever 181 arranged to cause movement of a drive link 190 . Spring 191 urges the drive link 190 into a selected operating position. The clamp arm 138 passes through an aperture 193 in the drive link 190 .
Initially the clamping mechanism adopts a pre-set mode as illustrated in FIG. 5 . In this mode the actuating lever 181 is urged into a preset position by spring 195 . The arrangement is such that clamp arm 138 is substantially free to move relative to braking bar 183 and drive link 190 the actuating lever 181 causing the drive link 190 to abut and be retained against lip 192 and pin 197 . In this pre-set mode control arm 187 under the influence of spring 188 urges brake arm 183 into a non-braking position in which control arm 138 and can be moved in both directions relative to support housing 171 . In this present mode stop 178 can be removed enabling the arm 138 to be removed and replaced. It will be appreciated the configuration of the clamp arrangement can take other forms depending upon its application. For example the arms may be of different lengths and the clamping device of different shapes for use under eaves, tree trunks, poles and the like.
When the device is required to be clamped to a structure such as gutter 60 the clamping mechanism is caused to adopt a set mode as illustrated in FIG. 6 . This is done before the device is raised to the position whereby it can be clamped to the gutter. It may be put in this mode prior to or initially when mounted to the ladder. In this set mode actuating lever 181 is pivotally displaced from its pre-set position so that the control arm 187 can be moved so as to be held by catch element 189 . In this position brake arm 183 is urged into a braking position under the influence of spring 185 . When in this position the brake arm 183 provides a resistance to movement of the clamp arm 138 in direction where stop 177 is displaced away from supporting housing 171 although movement in the other direction is still possible.
With the mechanism in the set mode the device can be drawn along the ladder from the base region thereof and positioned with a wall of the gutter disposed between stop 177 and the support body 102 of the device. This is illustrated in FIG. 9 . Pivotal movement of actuating lever 181 causes drive link 190 to incrementally move the clamp arm 138 so that stop 177 is brought into abutment against the wall of gutter 60 . Abutment section 198 causes displacement of link 190 off members 192 and 197 . In this position the device firmly clamps the ladder to the gutter 60 . The pivotal movement of the actuating lever can be effected from the base region of the ladder by pulling of line 132 connected thereto.
To release the device, catch element 189 is disengaged from control arm 187 which is caused to engage shoulder 175 on actuating lever 181 . This is a pre-release position and is illustrated in FIG. 10 . In this position the clamp arm 138 is yet to be released and the operator can descend the ladder. The abutment section 198 on actuating lever 181 causes drive link 190 to be displaced from lip 192 and pin 197 thereby effectively locking clamp arm 138 relative to the drive link 190 ; that it is the position of the drive link 190 which inhibits movement of the clamp arm 138 when clamped to the structure in this position. The clamp arm 138 could not move from this position even if the brake arm 183 adopted its non-braking position. By further pivotal displacement of actuating lever 181 using line 132 the control arm 187 is disengaged from the shoulder 175 on the actuating lever 181 whereupon it is caused to move under the influence of spring 188 to its pre-set position in which it acts on brake arm 183 so that it adopts the non-braking position. In this position lever 181 can move under the influence of spring 195 so that link 190 can return to the position shown in FIG. 5 and the device can be manipulated until it can be freed from the gutter whereupon it can be returned to the base position of the ladder.
Referring to FIGS. 11 to 15 there is shown another embodiment according to the invention with a modified form of catch element. The same numerals have been used to identify the same parts as shown in the earlier embodiments. In this embodiment the catch element 289 is pivotally mounted at pivot point 290 the same pivot point as for control arm 187 . An indexing member 292 is provided at one end of the catch element 289 . The indexing member 292 includes a knob 293 and a spring loaded pin 294 ( FIG. 14 ).
Referring to FIG. 11 the device is shown in the preset position. In this position the spring loaded pin 294 abuts against a face of the support housing wall 171 . In this position all other elements are arranged in the position as shown in FIG. 5 with reference to the first embodiment.
In order for the device to adopt the set position element 289 is rotated in the direction of arrow A in FIG. 11 until the pin under the influence of the spring associated therewith is located against the end of the housing 171 thereby preventing its return. Rotation of the element 289 into the position shown in FIG. 12 causes the control arm 187 to rotate into the position shown in FIG. 12 thereby activating braking bar 183 in the same fashion as described with reference to the first embodiment. The element 289 holds the arm 187 in the position shown in FIG. 12 . Pivotal movement of lever 181 in this position causes incremental movement of the clamp arm 138 in the same manner as described with reference to the first embodiment.
To effect the pre-release position element 289 is returned to its original position but control arm 187 is retained by stop 178 on lever 181 . To release the device lever 181 is pivotally displaced thereby facilitating the return of control arm 187 to its original position.
Referring to FIGS. 16 to 19 there is shown another embodiment according to the invention with yet a further modified form of catch element. Again the same reference numerals have been used to identify the same parts as shown in the earlier embodiments. In this embodiment the catch element 389 has a slot 394 in the element which can enable pivotal movement about pivot mount 390 as well as movement along the slot 394 . FIG. 16 illustrates the device in the preset mode with the elements functioning in the same fashion as shown in FIG. 5 with reference to the first embodiment. To adopt the set position catch element 389 is pivotally moved in the direction of arrow A in FIG. 16 to the position shown in FIG. 17 . The catch element 389 can lock over pin 197 on support housing 171 thereby holding the control arm 187 while actuating lever 181 is being activated to incrementally move the clamp arm 138 ( FIG. 19 ).
Prior to descent the operator releases catch element 389 by pivotal movement thereof by releasing it from pin 197 and moving it into a forward position as shown in FIG. 16 . The control arm 187 is held by stop 178 so that the mechanism is in its pre release mode. Upon descent activation of lever 181 by line 132 releases the mechanism as described earlier.
A manually operable apparatus is illustrated in FIG. 20 . In this embodiment the clamping mechanism 237 of the apparatus can be releasably secured to scaffold member 260 . The clamping mechanism 237 includes a clamp arm 238 in the form of a rod mounted to support housing 271 on bracket 247 . The support housing 237 is similar in structure to that described earlier. The clamp arm 238 is mounted in a similar fashion to that described earlier. The clamp arm 238 has a clamping stop 277 at one end thereof.
The clamp mechanism includes a releasably braking device 282 which in a braking position provides resistance to movement of the clamp arm 238 relative to the housing 271 in at least one direction. The braking device includes a braking bar 283 having an aperture 284 therein through which the clamp arm 238 passes. The braking bar 283 can adopt a braking position in which withdrawal of the clamp arm 238 from the housing 271 is resisted.
Spring 285 urges the braking bar 283 into a braking position in which relative movement between the clamp arm 238 and the housing 271 is resisted in one direction.
There is further provided an adjustment device 286 which is operable to enable incremental movement of the control arm 238 so that stop 277 is drawn towards the housing. The adjustment device 286 includes an actuating lever 281 arranged to cause movement of a drive link 290 . Spring 291 urges the drive link 290 into a braking position.
There is further provided a locking lever 222 which is engageable with the drive link 290 at section 294 .
In the position shown in the drawing, the clamping bar is clamped to the scaffold member 260 . In this position, the clamping bar is locked against movement which would loosen the clamping bars grip on the scaffold member. In order to move the clamping arm incrementally towards the scaffold member actuating lever 281 and locking lever 222 are pivotally displaced downwardly as shown in the drawing thereby causing incremental movement of the control arm 238 . When the clamping arm is in the position shown in the drawing the actuating arm and locking lever are released and the locking lever engages with a tooth 297 on control arm 238 . To release the mechanism firstly a slight downward pressure, is put on actuating arm 281 thereby releasing the locking lever which can be depressed so that it clears control arm 238 . By then raising the actuating arm and locking lever the braking bar is caused to adopt its release position so that the clamping arm can be displaced relative to the housing.
The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.
Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps.
Finally, it is to be understood that the inventive concept in any of its aspects can be incorporated in many different constructions so that the generality of the preceding description is not to be superseded by the particularity of the attached drawings. Various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit or ambit of the invention. | A ladder support apparatus, the apparatus including a support body, one or more clamp mechanisms operatively mountable to the support body, for mounting the support body to a structure and a retention assembly operatively connected to the support body and, in use, being adapted to limit relative movement between the ladder and ladder support, the or each clamping mechanism including a clamp aπn mounted for movement relative to the support body in a clamping direction and a release direction, an actuator operable to control the operation of the clamp arm, the clamp mechanism being arranged so as to be able to adopt a preset mode in which the clamp arm is substantially freely moveable in both the clamping direction and the release direction, a set mode in which the clamp arm is inhibited from movement in either direction but can be moved incrementally by operation of the actuator and a pre-release mode in which the clamp arm is inhibited from movement in either direction but upon operation of the actuator when in the pre-release mode the clamp arm can return to its preset mode. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to methods and apparatus for protecting against the influx of air into a pipeline carrying a combustible gas under negative pressure, and particularly to such methods and apparatus for use in association with a pipeline carrying natural gas under negative pressure from a natural gas well to a gas compressor.
BACKGROUND OF THE INVENTION
[0002] Natural gas is commonly found in subsurface geological formations such as deposits of granular material (e.g., sand or gravel) or porous rock. Production of natural gas from these types of formations typically involves drilling a well a desired depth into the formation, installing a casing in the wellbore (to keep the well bore from sloughing and collapsing), perforating the casing in the production zone (i.e., the portion of the well that penetrates the gas-bearing formation) so that gas can flow into the casing, and installing a string of tubing inside the casing down to the production zone. Gas can then be made to flow up to the surface through a production chamber, which may be either the tubing or the annulus between the tubing and the casing. The gas flowing up the production chamber is conveyed through an intake pipeline running from the wellhead to the suction inlet of a wellhead compressor. The compressed gas discharged from the compressor is then conveyed through another pipeline to a gas processing facility and sales facility as appropriate.
[0003] When natural gas is flowing up a well, formation liquids will tend to be entrained in the gas stream, in the form of small droplets. As long as the gas is flowing upward at or above a critical velocity (the value of which depends on various well-specific factors), the droplets will be lifted along with the gas to the wellhead. In this situation, the gas velocity provides the means for lifting the liquids, and the well is said to be producing by “velocity-induced flow”. Because liquids in the gas stream can cause internal damage to most gas compressors, a gas-liquid separator is provided in the intake pipeline to remove liquids from the gas stream before entering the compressor. The liquids may be pumped from the separator and reintroduced into the gas flow at a point downstream of the compressor, for eventual separation at the gas processing facility. Much more commonly, however, the liquids are collected in a tank on the well site.
[0004] In order to optimize total volumes and rates of gas recovery from a gas reservoir, the bottomhole flowing pressure should be kept as low as possible. The theoretically ideal case would be to have a negative bottomhole flowing pressure so as to facilitate 100% gas recovery from the reservoir, resulting in a final reservoir pressure of zero. In order to reduce the bottomhole pressure to a negative value, or to a very low positive value, it would be necessary to have a negative flowing pressure (i.e., less than atmospheric pressure) in the intake pipeline. This can be readily accomplished using well-known technology; i.e., by providing a wellhead compressor of sufficient power.
[0005] However, negative pressure in a natural gas pipeline would present an inherent problem, because any leak in the line (e.g., at pipeline joints) would allow the entry of air into the pipeline, because air would naturally flow to the area of lower pressure. This would create a risk of explosion should the air/gas mixture be exposed to a source of ignition. In addition to the explosion risk, entry of air into the pipeline also creates or increases the risk of corrosion inside the pipeline. For these reasons, the pressure in the intake pipeline is typically maintained at a positive level (i.e., higher than atmospheric). Therefore, in the event of a leak in the intake pipeline, gas in the pipeline will escape into the atmosphere, rather than air entering the pipeline. The explosion and corrosion risks are thus minimized or eliminated, but in a way that effectively limits ultimate recovery of gas reserves from the well.
[0006] One way of minimizing or eliminating the explosion and corrosion risks, while facilitating the use of negative pressures in the intake pipeline, would be to provide an oxygen sensor in association with the pipeline. The oxygen sensor would be adapted to detect the presence of oxygen inside the pipeline, and to shut down the compressor immediately upon detection of oxygen. This system thus would more safely facilitate the use of compressor suction to induce negative pressures in the intake pipeline and, therefore, to induce negative or low positive bottomhole flowing pressures. However, this system has an inherent drawback in that its effectiveness would rely on the proper functioning of the oxygen sensor. If the sensor malfunctions, and if the malfunction is not detected and remedied in timely fashion, the risk of explosion and/or corrosion will become manifest once again. This fact highlights an even more significant drawback in that this system would not prevent the influx of air into the pipeline in the first place, but is merely directed to mitigation in the event of that undesirable event.
[0007] For the foregoing reasons, there is a need for an improved method and apparatus for minimizing and protecting against the risk of explosion arising from the influx of air into a pipeline carrying a combustible gas such as natural gas under negative pressure. There is a particular need for such methods and apparatus that do not require or rely on the use of oxygen sensors or other instruments or devices that are prone to malfunction. Even more particularly, there is a need for such methods and apparatus that prevent the influx of air into the pipeline in the first place. The present invention is directed to these needs.
BRIEF DESCRIPTION OF THE INVENTION
[0008] In general terms, the present invention provides a method and apparatus whereby the intake pipeline running between the production chamber of a natural gas well and the suction inlet of an associated wellhead compressor is completely enclosed, in vapour-tight fashion, within a jacket of natural gas under positive pressure (i.e., higher than atmospheric). Being enclosed inside this “positive pressure jacket”, the intake pipeline is not exposed to the atmosphere at any point. This allows gas to be drawn into the compressor through the intake pipeline under a negative pressure, without risk of air entering the intake pipeline should a leak occur in the pipeline. If such a leak occurs, there would merely be a harmless transfer of gas from the positive pressure jacket into the intake pipeline. If a leak occurs in the positive pressure jacket, gas therefrom would escape into the atmosphere, and entry of air into the positive pressure jacket would be impossible.
[0009] Accordingly, in one aspect the present invention is a positive pressure gas jacket apparatus for use in association with a natural gas well facility, said well facility comprising:
(a) a wellbore extending from ground surface into a subsurface gas production zone; (b) a wellhead apparatus at the top of the wellbore; (c) a tubing string extending from the wellhead into the wellbore, for conveying gas from the production zone, said tubing string and wellbore defining an annulus; (d) an upstream pipeline in fluid communication with a production chamber selected from the tubing and the annulus, and connecting to the suction manifold of a gas compressor; and (e) a downstream pipeline extending from the discharge manifold of the compressor:
said apparatus comprising:
(f) a vapour-tight enclosure defining an internal chamber surrounding the upstream pipeline; and (g) a gas recirculation pipeline extending between a selected point on the downstream pipeline and a selected point on the vapour-tight enclosure, such that the gas recirculation pipeline is in fluid communication with both the downstream pipeline and the internal chamber of the vapour-tight enclosure;
characterized in that the upstream pipeline will be completely enveloped by pressurized natural gas introduced into the internal chamber from the downstream pipeline via the recirculation pipeline.
[0017] In a second aspect, the invention is a method of preventing air leaks into the upstream pipeline of a natural gas well facility as described above, the method comprising the steps of:
(f) providing a vapour-tight enclosure defining an internal chamber surrounding the upstream pipeline; and (g) providing a gas recirculation pipeline extending between a selected point on the downstream pipeline and a selected point on the vapour-tight enclosure, such that the gas recirculation pipeline is in fluid communication with both the downstream pipeline and the internal chamber of the vapour-tight enclosure;
said method being characterized in that the upstream pipeline will be completely enveloped by pressurized natural gas introduced into the internal chamber from the downstream pipeline via the recirculation pipeline.
[0020] In preferred embodiments of the apparatus and the method, a throttling valve is provided in the recirculation pipeline, for regulating the flow of gas from the downstream pipeline into the recirculation pipeline.
[0021] Also in preferred embodiments, a pressure regulator valve (PRV) is disposed between the internal chamber of the vapour-tight enclosure and a well injection chamber selected from the tubing and the annulus, said injection chamber not being the production chamber. The PRV is adapted to prevent gas pressure in the internal chamber from exceeding a selected pre-set value, by allowing gas from the internal chamber to enter the well injection chamber when the internal chamber pressure exceeds the pre-set value.
[0022] The vapour-tight enclosure is preferably of welded steel construction. However, other materials and known fabrication methods may be used without departing from the scope of the invention.
[0023] In the preferred embodiment, the positive pressure gas jacket apparatus also comprises a gas-liquid separator apparatus connected into the upstream pipeline for separating liquids out of raw gas from the well, with a liquid discharge line for removing separated liquids, and with the internal chamber of the vapour-tight enclosure surrounding the separator apparatus as well as the upstream pipeline. In accordance with this embodiment, pressurized gas introduced into the internal chamber from the downstream pipeline via the recirculation pipeline will completely envelope both the separator apparatus and the discharge line.
[0024] In a particularly preferred embodiment, the separator apparatus comprises a separator vessel, a blow case, and a liquid transfer line for carrying separated liquids from the separator vessel to the blow case. The blow case is of a type well known in the art, being a pressure vessel for retaining the separated liquids under positive pressure. The liquid discharge line connects to the blow case and extends therefrom through the vapour-tight enclosure for conveying liquids from the blow case under positive pressure to a liquid disposal point (which may be a storage tank, or alternatively may be a connection to the downstream pipeline). Since the liquids leave the blow case under positive pressure, it is not necessary for the vapour-tight enclosure to enclose any portion of the liquid discharge line.
[0025] In an alternative embodiment not having a blow case, liquids removed by the separator apparatus are discharged into the liquid discharge line under negative pressure, and the liquid discharge line connects to a vacuum pump, which in turn discharges the liquids under positive pressure into a liquid return line. The internal chamber of the vapour-tight enclosure surrounds the liquid discharge line as well as the separator apparatus and the upstream pipeline, such that pressurized gas introduced into the internal chamber from the downstream pipeline via the recirculation pipeline will completely envelope the upstream pipeline, the separator apparatus, and the discharge line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Embodiments of the invention will now be described with reference to the accompanying figures, in which numerical references denote like parts, and in which:
[0027] FIG. 1 is a schematic diagram of a well producing natural gas in accordance with prior art methods and apparatus.
[0028] FIG. 2 is a schematic diagram of a well producing natural gas in accordance with a preferred embodiment of the method and apparatus of the present invention.
[0029] FIG. 3 is a schematic diagram of a well producing natural gas in accordance with an alternative embodiment of the method and apparatus of the invention.
[0030] FIG. 4 is a partial cutaway schematic diagram of a separator having a positive pressure gas jacket in accordance with a preferred embodiment of the invention.
[0031] FIG. 5 is a schematic diagram of a gas well producing natural gas using a prior art gas injection system.
[0032] FIG. 6 is a schematic diagram of the gas well shown in FIG. 5 , producing natural gas using a prior art gas injection system, modified to incorporate the positive pressure jacket of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] The present invention will be best understood after first reviewing conventional methods and apparatus for carrying natural gas from a well to a compressor. FIG. 1 schematically illustrates a typical natural gas well W configured in accordance with prior art methods and apparatus. The well W penetrates a subsurface formation F containing natural gas (typically along with water and crude oil in some proportions). The well W is lined with a casing 20 which has a number of perforations conceptually illustrated by short lines 22 within a production zone (generally corresponding to the portion of the well penetrating the formation F). As conceptually indicated by arrows 24 , formation fluids including gas, oil, and water may flow into the well through the perforations 22 . A string of tubing 30 extends inside the casing 20 , terminating at a point within the production zone. The bottom end of the tubing 30 is open such that fluids in the wellbore may freely enter the tubing 30 . An annulus 32 is formed between the tubing 30 and the casing 20 . The upper end of the tubing 30 runs into a surface termination apparatus or “wellhead” (not illustrated), of which various types are known in the field of gas wells.
[0034] It should be noted that, to facilitate illustration and understanding of the invention, the Figures are not drawn to scale. The diameter of the casing 20 is commonly in the range of 4.5 to 7 inches (114 to 178 mm), and the diameter of the tubing 30 is commonly in the range of 2.375 to 3.5 inches (60 to 89 mm), while the well W typically penetrates hundreds or thousands of feet into the ground. It should also be noted that except where indicated otherwise, the arrows in the Figures denote the direction of flow within various components of the apparatus.
[0035] In the well configuration shown in FIG. 1 , the tubing 30 serves as the production chamber to carry gas from the well W, under positive pressure, via the wellhead (not shown) to a production pipeline 40 having an upstream section 40 U which carries the gas through a gas-liquid separator 70 to the suction manifold 42 S of a gas compressor 42 . The separator 70 divides the upstream pipeline into section 40 U′ on the wellhead side of the separator, and section 40 U″ on the compressor side of the separator 70 . The production pipeline 40 also has a downstream section 40 D which connects at one end to the discharge manifold 42 D of the compressor 42 and continues therefrom to a gas processing facility (not shown). As schematically indicated, liquids 72 separated from the gas flowing in the intake pipeline 40 U′ will accumulate in a lower section of the separator 70 . In the usual case, the liquids 72 flow from the separator 70 to a storage tank 80 on the well site.
[0036] The present invention may be best understood from reference to FIG. 2 . The invention provides for production of gas under negative pressure, in which case the liquids 72 removed from the gas stream by the separator 70 will also be under negative pressure, and for this reason a vacuum pump 74 is provided as shown. The liquids 72 flow under negative pressure through a pump inlet line 78 to the pump 74 , which pumps the liquids 72 , now under positive pressure, through a liquid return line 76 into the downstream section 40 D of production pipeline 40 at a point Z downstream of the compressor 42 . Alternatively, the liquids 72 may be pumped to an on-site storage tank 80 .
[0037] As illustrated in FIG. 2 , the upstream pipeline sections 40 U′ and 40 U″, the separator 70 , and the pump inlet line 78 are fully enclosed by a vapour-tight positive pressure jacket 50 that defines a continuous internal chamber 52 . The positive pressure jacket 50 will typically be constructed of welded steel. However, suitable and well-known alternative materials may be used without departing from the fundamental concept and scope of the present invention.
[0038] A gas recirculation pipeline 60 extends between, and is in fluid communication with, the downstream section 40 D of production pipeline 40 (at point X located between the compressor 42 and point Z) and a selected pressure connection point Y on the positive pressure jacket 50 . As shown in FIG. 2 , pressure connection point Y may be located in upstream pipeline section 40 U″ between the compressor 42 and the separator 70 . However, this is not essential; pressure connection point Y may be at any convenient location on the positive pressure jacket 50 —such as, for example, on the portion of the positive pressure jacket 50 surrounding the separator 70 , as schematically indicated by broken lines (marked 61 ), which depict an optional alternative routing of the recirculation pipeline 60 .
[0039] By means of the recirculation pipeline 60 , a portion of the gas discharged from the discharge manifold 42 D of the compressor 42 may be diverted into the positive pressure jacket 50 , such that the upstream pipeline sections 40 U′ and 40 U″, the separator 70 , and the pump inlet line 78 are entirely enclosed by a “blanket” of gas under positive pressure.
[0040] The positive pressure jacket 50 thus enshrouds all components of the apparatus containing combustible fluids under negative pressure between the wellhead and the suction manifold 42 S of compressor 42 with a blanket of gas under positive pressure, thereby preventing the entry of air into the combustible fluids present in any of those components.
[0041] In the preferred embodiment, the positive pressure jacket 50 also encloses any portions of the wellhead containing gas under negative pressure.
[0042] The embodiment shown in FIG. 2 provides for what may be termed a “static” positive pressure blanket, as the gas inside the positive pressure jacket 50 will be essentially stationary. In an alternative embodiment of the invention, illustrated in FIG. 3 , the internal chamber 52 of the positive pressure jacket 50 is in fluid communication with the annulus 32 of the well W, such that gas from the internal chamber 52 of the positive pressure jacket 50 can be injected into the annulus 32 . As shown schematically in FIG. 3 , a pressure regulator valve 54 is provided to regulate the gas pressure inside the positive pressure jacket 50 . The pressure regulator valve 54 may be set such that it will open, thus allowing gas to enter the annulus 32 , only when the gas pressure in the internal chamber 52 of the positive pressure jacket 50 is above a selected value. Under either static conditions (as in FIG. 2 ) or gas injection conditions (as in FIG. 3 ), internal chamber pressures in the approximate range of 40 to 50 pounds per square inch (275 to 345 kPa) are considered desirable. However, higher or lower pressures may be used without departing from the concept and principles of the present invention.
[0043] As schematically illustrated in FIG. 3 , a throttling valve (or “choke”) 62 optionally may be provided in association with the recirculation pipeline 60 , to regulate the flow of gas from the downstream section 40 D of production pipeline 40 into the recirculation pipeline 60 and thence into the internal chamber 52 of the positive pressure jacket 50 and ultimately into the well W.
[0044] FIG. 4 schematically illustrates a preferred construction of the separator 70 and the corresponding section of the positive pressure jacket 50 in accordance with the present invention. In this embodiment, the separator 70 comprises two main components, a vertical separator 90 and a blow case 100 , the construction and operation of which are in accordance with well known technology. Upstream pipeline section 40 U′ delivers raw well gas under negative pressure to the separator. Upstream pipeline section 40 U″ delivers dry gas from the separator 70 to the suction manifold 42 S of the compressor 42 . The vertical separator 90 and blow case 100 are enclosed within a separator jacket 55 forming part of the overall positive pressure jacket 50 . Injection pipeline 60 , carrying gas under pressure from the downstream pipeline 40 D, is connected to the positive pressure jacket 50 at pressure connection point Y (which in the embodiment shown in FIG. 4 is located on separator jacket 55 , but may be located elsewhere on the positive pressure jacket 50 as previously mentioned). Regardless of the location of pressure connection point Y, gas under pressure is introduced into the internal chamber 52 of the positive pressure jacket 50 , such that all system components carrying raw gas from the well W under negative pressure will be surrounded by gas under positive pressure.
[0045] Liquids 72 removed from the gas are discharged from the vertical separator 90 at liquid outlet 96 through liquid transfer line 98 , which in turn carries the liquids 72 to the blow case 100 through blow case inlet port 102 . The blow case 100 accumulates separated liquids under positive pressure. Liquid return line 76 connects to the blow case 100 at blow case discharge port 104 . A check valve 106 prevents liquids from being discharged from the blow case 100 unless the pressure in the blow case exceeds a pre-set value. In this embodiment, there is no need for a pump 74 (as in the embodiments shown in FIG. 2 and FIG. 3 ) and therefore no pump inlet line 78 . The flow in the liquid return line 76 will always be under positive pressure as it exits the separator jacket 55 .
[0046] Alternative methods of constructing the positive pressure jacket 50 around the separator 70 , using known fabrication methods and materials, will be readily apparent to persons skilled in the art, without departing from the principles of the invention.
[0047] The method and apparatus of the present invention can be particularly advantageous when used in conjunction with gas wells in which gas injection is used to enhance recovery of gas from the formation F. Gas injection provides this benefit by further reducing bottomhole pressures in the well W. Formation pressures in virgin gas reservoirs tend to be relatively high. Therefore, upon initial completion of a well, the gas will commonly rise naturally to the surface provided that the characteristics of the reservoir and the wellbore are suitable to produce stable flow (meaning that the gas velocity at all locations in the production chamber remains equal to or greater than the critical velocity—in other words, velocity-induced flow).
[0048] However, as wells penetrate the reservoir and gas reserves are depleted, the formation pressure drops continuously, inevitably to a level too low to induce gas velocities high enough to sustain stable flow. Therefore, all flowing gas wells producing from reservoirs with depleting formation pressure eventually become unstable. Once the gas velocity has become too low to lift liquids, the liquids accumulate in the wellbore, and the well is said to be “liquid loaded”. This accumulation of liquids results in increased bottomhole flowing pressures and reduced gas recoveries. Injection of recirculated gas can effectively prevent or alleviate liquid loading, by increasing the upward velocity of the gas stream in the production chamber so as to maintain a gas velocity at or above the critical velocity for the well in question, thus maintaining velocity-induced flow. Methods and apparatus for gas injection for this purpose are described in the present Applicant's Canadian Patent Application No. 2,242,745, filed on Apr. 9, 2003 and corresponding International Application No. PCT/CA2004/000478, filed on Mar. 30, 2004.
[0049] FIG. 5 illustrates a gas well producing natural gas using an embodiment of the gas injection system disclosed in PCT/CA2004/000478. In the well configuration shown in FIG. 5 , the tubing 30 serves as the production chamber to carry gas from the well W to an above-ground production pipeline 40 , which has an upstream section 40 U and a downstream section 40 D. The tubing 30 connects in fluid communication with one end of the upstream section 40 U (via wellhead apparatus, not shown), and the other end of the upstream section 40 U is connected to the suction manifold 42 S of a gas compressor 42 . The downstream section 40 D of the production pipeline 40 connects at one end to the discharge manifold 42 D of the compressor 42 and continues therefrom to a gas processing facility (not shown). A gas injection pipeline 16 , for diverting production gas from the production pipeline 40 for injection into the injection chamber (i.e., the annulus 32 , in FIG. 5 ), is connected at one end to the downstream section 40 D of the production pipeline 40 at a point Q, and at its other end to the top of the injection chamber. Also provided is a throttling valve (or “choke”) 12 , which is operable to regulate the flow of gas from the production pipeline 40 into the injection pipeline 16 and the injection chamber.
[0050] The choke 12 may be of any suitable type. In a fairly simple embodiment of the apparatus, the choke 12 may be of a manually-actuated type, which may be manually adjusted to achieve desired rates of gas injection, using trial-and-error methods as may be necessary or appropriate; with practice, a skilled well operator can develop a sufficiently practical ability to determine how the choke 12 needs to be adjusted to achieve stable gas flow in the production chamber, without actually quantifying the necessary minimum gas injection rate or the flow rate in the production chamber. Alternatively, the choke 12 may be an automatic choke; e.g., a Kimray® Model 2200 flow control valve.
[0051] In the preferred embodiment, however, a flow controller 150 is provided for operating the choke 12 . Also provided is a flow meter 14 adapted to measure the rate of total gas flow up the production chamber, and to communicate that information to the flow controller 50 . The flow controller 150 may be a pneumatic controller of any suitable type; e.g., a Fisher™ Model 4194 differential pressure controller.
[0052] To implement the gas injection system illustrated in FIG. 5 , a critical gas flow rate is determined. The critical flow rate, which may be expressed in terms of either gas velocity or volumetric flow, is a parameter corresponding to the minimum velocity V cr that must be maintained by a gas stream flowing up the production chamber (i.e., the tubing 30 , in FIG. 5 ) in order to carry formation liquids upward with the gas stream (i.e., by velocity-induced flow). This parameter is determined in accordance with well-established methods and formulae taking into account a variety of quantifiable factors relating to the well construction and the characteristics of formation from which the well is producing. A minimum total flow rate (or “set point”) is then selected, based on the calculated critical flow rate, and flow controller 150 is set accordingly. The selected set point will preferably be somewhat higher than the calculated critical rate, in order to provide a reasonable margin of safety, but also preferably not significantly higher than the critical rate, in order to minimize friction loading in the production chamber.
[0053] If the total flow rate measured by the meter 14 is less than the set point, the flow controller 150 will adjust the choke 12 to increase the gas injection rate if and as necessary to increase the total flow rate to a level at or above the set point. If the total flow rate is at or above the set point, there may be no need to adjust the choke 12 . The flow controller 50 may be adapted such that if the total gas flow is considerably higher than the set point, the flow controller 150 will adjust the choke 12 to reduce the gas injection rate, thus minimizing the amount of gas being recirculated to the well through injection, and maximizing the amount of gas available for processing and sale.
[0054] In one particular embodiment of the gas injection system, the flow controller 150 has a computer with a microprocessor (conceptually illustrated by reference numeral 160 ) and a memory (conceptually illustrated by reference numeral 162 ). The flow controller 150 also has a meter communication link (conceptually illustrated by reference numeral 152 ) for receiving gas flow measurement data from the meter 14 . The meter communication link 152 may comprise a wired or wireless electronic link, and may comprise a transducer. The flow controller 150 also has a choke control link (conceptually illustrated by reference numeral 154 ), for communicating a control signal from the computer 160 to a choke control means (not shown) which actuates the choke 12 in accordance with the control signal from the computer. The choke control link 154 may comprise a mechanical linkage, and may comprise a wired or wireless electronic link.
[0055] Using this embodiment of the apparatus, the set point is stored in the memory 162 . The computer 160 receives a signal from the meter 14 (via the meter communication link 152 ) corresponding to the measured total gas flow rate in the production chamber, and, using software programmed into the computer 160 , compares this value against the set point. The computer 160 then calculates a minimum injection rate at which supplementary is gas must be injected into the injection chamber, or to which the injection rate must be increased in order to keep the total flow rate at or above the set point. This calculation takes into account the current gas injection rate (which would be zero if no gas is being injected at the time). If the measured total gas flow is below the set point, the computer 160 will convey a control signal, via the choke control link 154 , to the choke control means, which in turn will adjust the choke 12 to deliver injection gas, at the calculated minimum injection rate, into the injection pipeline 16 , and thence into the injection chamber of the well (i.e., the annulus 32 , in FIG. 1 ). If the measured total gas flow equals or exceeds the set point, no adjustment of the choke 12 will be necessary, strictly speaking.
[0056] However, the computer 160 may also be programmed to reduce the injection rate if it is substantially higher than the set point, in order to minimize the amount of gas being recirculated to the well W, thus maximizing the amount of gas available for processing and sale, as well as to minimize friction loading. In fact, situations may occur in which there effectively is a “negative” gas injection rate; i.e., where rather than having gas being injected downward into the well through a selected injection chamber, gas is actually flowing to the surface through both the tubing 30 and the annulus 32 . This situation could occur when formation pressures are so great that the upward gas velocity in the selected production chamber is not only high enough to maintain a velocity-induced flow regime, but also so high that excessive friction loading develops in the production chamber. In this scenario, gas production would be optimized by producing gas up both chambers, thus reducing gas velocities and resultant friction loading (provided of course that the gas velocity—which will be naturally lower than when producing through only one chamber—remains above V cr at all points in at least one of the chambers; i.e., so that there is stable flow in at least one chamber).
[0057] FIG. 6 illustrates the well and gas injection system shown in FIG. 5 , but modified to incorporate the positive pressure jacket of the present invention, with separator and positive pressure jacket components corresponding to those described and illustrated in connection with FIG. 2 and FIG. 5 . In the embodiment shown in FIG. 6 , the recirculation pipeline 60 ties in to the injection pipeline 16 , but this is only a representative illustration of one means of providing gas under positive pressure to the internal chamber 52 of the positive pressure jacket 50 . For example, the recirculation pipeline 60 could be a separate line connecting to downstream pipeline 40 D, independent of injection pipeline 16 .
[0058] Although not illustrated, it will be appreciated that the gas injection embodiments shown in FIGS. 3, 4 , and 6 can be readily adapted for use in association with a gas well in which the annulus 32 serves as the production chamber. In that case, the upstream section 40 U of intake pipeline 40 will be in fluid communication with the annulus 32 , and the internal chamber 52 of the positive pressure jacket 50 will be in fluid communication with the production tubing 30 . Accordingly, pressurized gas diverted into the internal chamber 52 will be injected into the well W through the tubing 30 , with the same production-enhancing benefits as described previously in connection with embodiments wherein the tubing 30 serves as the production chamber.
[0059] 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.
[0060] 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. | The present invention provides a method and apparatus whereby the intake pipeline running between the production chamber of a natural gas well and the suction inlet of an associated wellhead compressor is completely enclosed, in airtight fashion, within a jacket of natural gas under positive pressure (i.e., higher than atmospheric). Being enclosed inside this “positive pressure jacket”, the intake pipeline is not exposed to the atmosphere at any point. This allows gas to be drawn into the compressor through the intake pipeline under a negative pressure, without risk of air entering the intake pipeline should a leak occur in the pipeline. If such a leak occurs, there will merely be a harmless transfer of gas from the positive pressure jacket into the intake pipeline. If a leak occurs in the positive pressure jacket, gas therefrom will escape into the atmosphere, and entry of air into the positive pressure jacket will be impossible. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to electric plugs, and more particularly to such plugs incorporating integral over-current protection such as circuit breakers.
A wide variety of devices have been developed for providing over-current protection at the electric plug. One such approach is to provide a circuit breaker box interposed between a conventional electric plug and a conventional outlet receptacle. This device is disclosed in U.S. Pat. No. 4,484,185, issued Nov. 20, 1984, to Graves entitled SAFETY PLUG ADAPTOR. However, such devices protrude excessively from the outlet, creating safety problems and preventing appliances from being placed against the wall in which the plug is mounted. Further, the necessity of a separate box creates inventory and installation problems. Third, the box must be secured to the receptacle cover plate further complicating the construction and use of this device.
A second type of electric safety plug is illustrated in U.S. Pat. Nos. 4,086,643 and Des. 246,241 issued Apr. 25, 1978 and Nov. 1, 1977, respectively, to Jacobs, entitled COMBINATION PLUG AND POWER CUT-OFF UNIT. This plug includes a hollow multi-piece housing which supports the power cord connection, a circuit breaker, and the prong assembly. The breaker trips whenever excessive current is conducted through the prongs. This plug also suffers several disadvantages. First, its profile is excessively large so that the assembly protrudes undesirably from the receptacle. Second, the multi-piece housing can come open exposing dangerous electric connections. Third, the many pieces required to assemble this plug create inventory and assembly problems.
A third type of electric safety plug is sold by The Belden Division of Cooper Industries located in Geneva, Ill. This plug includes a plug body integrally molded over the end of a power cord and integrally supporting common and ground prongs. The housing also defines a bayonet fuse socket. A bayonet fuse with an integral power prong mounted thereon is releasably secured within the socket. If excessive current flows through the power prong, the integral fuse blows and power is interrupted. To reestablish the connection, the plug must be withdrawn from the outlet; the bayonet fuse must be removed; a proper bayonet replacement fuse must be located and reinstalled within the plug housing; and the plug must be reinserted into the outlet. This plug has several drawbacks. First, the plug must be removed from the receptacle each time the fuse is to be checked or replaced. Second, an inventory of fuses must be maintained to provide replacement capability. Third, the plug is relatively expensive to operate since the fuse-and-prong assembly must continually be replaced.
SUMMARY OF THE INVENTION
The aforementioned problems are overcome in the present invention wherein an electric safety plug is provided including an integral circuit breaker in a low profile housing. In a first embodiment of the invention, the plug includes an injection-molded housing molded directly onto the end of a power cord. The housing integrally supports the plug prongs and also a circuit breaker connected in series with one of the prongs. All electric connections are encapsulated within the molded plug housing and therefore cannot become exposed during rough handling of the plug. The relatively simple construction reduces the number of parts, and hence the cost, of the plug.
In a second aspect of the invention, the housing is elongated, and the prongs extend from one of the elongated faces. Consequently, when the plug is installed within a outlet, the elongated plug body lies relatively flat against the wall. Further in this embodiment, the plug prongs are angularly oriented with respect to the elongated body so that the body will not overlie an adjacent outlet when mounted in a first outlet. This enables multiple plugs to be utilized side-by-side in duplex outlets.
In a third aspect of the invention, these two features are combined to provide an integrally molded elongated plug housing which integrally supports the plug prongs and circuit breaker. The power cord enters one end and the circuit breaker is positioned within the opposite end so that the plug has a low profile against the wall.
These and other objects, advantages, and features of the invention will be more readily and understood and appreciated by reference to the detailed description of the preferred embodiment of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the electric safety plug;
FIG. 2 is a front elevational view of the plug;
FIG. 3 is a longitudinal sectional view through the plug;
FIG. 4 is a front elevational view of the circuit breaker;
FIG. 5 is a schematic diagram of the electric connections within the plug;
FIG. 6 is an elevational view of two of the plugs mounted in a duplex outlet; and
FIG. 7 is a top plan view of the plug housing only.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A safety electric plug constructed in accordance with a preferred aspect of the invention is illustrated in the drawings and generally designated 10. Basically, the plug includes a plug housing or body 12, a prong assembly 14, and a circuit breaker or other over-current protection means 16. The one-piece housing 12 is integrally molded onto the power cord 18 and integrally supports both the prong assembly 14 and the circuit breaker 16. Consequently, the present plug provides integral over-current protection in a compact low-profile assembly.
The housing 12 (FIGS. 1-3 and 7) is preferably injection molded to provide a unitary support mechanism for the remaining components. The housing is elongated including a longitudinal axis 30 and includes opposite relatively narrow top and bottom ends 32 and 34. The bottom end 34 is integrally molded onto the power cord 18 to provide a secure interconnection between the housing and power cord. The cross-sectional configuration of the plug perpendicular to the axis 30 is generally rectangular so that the plug includes a front face 36, a rear face 38, and left and right faces 40 and 42. Gripping ridges 44 and 46 extend the full length of the left and right sides 40 and 42, respectively, to provide a mechanism by which the plug housing can be more easily grasped.
The housing 12 defines a chamber 50 (FIG. 3) which opens through the top end 32. The chamber is generally elongated and oriented generally parallel to the axis 30. As seen in FIG. 7, the chamber 50 is generally square in cross section and extends from the top end 32 to a floor 52 which is approximately midway along the length of the housing 12. A pair of slots 54a and 54b are defined in the floor 52 of the chamber 50 to receive prongs on the circuit breaker as will be described. The perimeter 56 of the opening of the chamber 50 receives the face of the circuit breaker.
The power cord 18 (FIGS. 3 and 5) is generally well known to those having ordinary skill in the art. This is a three-conductor cord including power, common, and ground conductors. The power cord 18 includes an insulating/protective jacket preferably of the same color as the housing 12.
The prong assembly 14 (FIGS. 1-2 and 5) is mounted within the front face 36 at a location proximate the bottom end 34. The prong assembly includes a power prong 60, a power prong (also referred to as a common prong) 62, and a ground prong 64. Preferably, the prongs are fabricated of copper to provide good electric conductivity. The prongs are electrically connected to the conductors within the power cord 18 as will be described. The prongs are sized and arranged to interfit with a conventional receptacle outlet as is well known to those having ordinary skill in the art. The housing 12 is integrally molded about the prongs such that the prongs are integrally and directly supported by the housing. Such structure eliminates the necessity of additional structure for supporting the prong assembly 14. The prongs are generally perpendicular to the axis 30 (see FIG. 3). Further, an imaginary line 70 drawn through the two power prongs 60 and 62 forms an acute angle with the axis 30. Although an angle of approximately forty-five degrees is disclosed, this angle should be substantially nonperpendicular. Preferably, the angle should be in the range zero degrees to approximately forty-five degrees as will be described.
The circuit breaker 16 (FIGS. 3 and 4) are generally well known in the art and are typically referred to as panel breakers since they are most commonly installed within planar control panels. The breaker used in the preferred embodiment is that sold by Mechanical Products, Inc. of Jackson, Mich. as the 2000 Series. The breaker generally includes a body 80 defining a face 82 at one end and integrally supporting prongs 84 at its opposite end. The breaker body is plastic and includes upper and lower spring fingers or other ratchet means 86 which lock the breaker within the chamber 50. The prongs 84 interfit with the slots 542 and 546 in the floor 52 of the chamber 50 to make electric connection with the power conductor in the cord 18 through one slot and the power prong 60 through the other slot. The face 82 fits closely within the perimeter 56 so that the facing 82 is slightly recessed within the housing end 32. As seen in FIG. 1, the breaker further includes a reset button 88 which can be depressed, or pushed in the direction of housing 12, to rest the breaker after it is tripped. The breaker body 80 is generally closely received within the chamber 50. The spring fingers 86 ratchet against the walls of the chamber 50 permitting the breaker to be slid into the chamber 50 during installation but not easily subsequently withdrawn. The breaker capacity will be selected depending on the application. Currently anticipated capacities are in the range 0.25 to 15 amps.
The electric interconnections in the plug are schematically illustrated in FIG. 5. The power cord 18 includes a power conductor 90, a common conductor 92, and a ground conductor 94. The circuit breaker 16 is coupled in series with the power prong 60. Specifically, electric connections, (not specifically shown) are provided in sockets 54a and 54b by which means the circuit breaker 16 is connected with the power conductor 90 and the prong 60. The common conductor 92 is coupled directly to the common prong 62, and the ground conductor 94 is coupled directly to the ground prong 64. All electric connections are made in a manner well-known in the art and are encapsulated within the integrally molded housing 12. The connections are therefore protected from exposure even upon rugged use of the housing.
ASSEMBLY AND OPERATION
Manufacture of the plug is initiated by making all electric connections which will be encapsulated within the plug housing 12. These connections are schematically illustrated in FIG. 5. Specifically, the power conductor 90 is coupled to one socket 54b, and the power prong 60 is coupled to the other socket 54a. The common wire 52 is coupled to the common prong 62; and the ground conductor 94 is coupled to the ground prong 64. The prong assembly 14 is then mounted within a mold insert which holds the prongs in position for subsequent molding. The insert can be rotated through 360 degrees so that the prong assembly 14 can be installed at any desired angular orientation to the housing axis 30.
After all electric connections have been made, the housing 12 is injection molded onto the power cord 18 and the prong assembly 14. During molding, all electric connections are encapsulated within the housing 12.
After the housing cures, the circuit breaker 16 is installed within the chamber 50. As the circuit breaker is slid into the chamber, the prongs 84 slide into slots to establish electric connection with the power conductor 90 and the power prong 60 such that the circuit breaker is coupled in series with the power prong 60. Also as the breaker is slid into position, the fingers 86 engage the chamber walls and are slightly compressed thereby. Breaker insertion continues until the facing 82 extends slightly into perimeter 56. The compressed fingers 86 provide a ratcheting effect to prevent inadvertent removal of the breaker from the housing 12.
The plug can be mounted on any appliance power cord or in conjunction with any device requiring electric power. The plug has its greatest utility in conjunction with appliances which draw large currents such as table saws or other devices with relatively large electric motors. Whenever the appliance or device draws excessive current, the circuit breaker 16 trips to interrupt power to the power prong 60 and consequently to the device powered by the cord. After corrective action has been taken to remedy the over-current situation, the breaker 16 is reset simply by depressing the reset button 88. The plug therefore provides infinitely resettable over-current protection for the appliance.
The desirability of the angular orientation of the prong assembly 14 is illustrated in FIG. 6. Two plugs 10a and 10b are illustrated mounted side-by-side within a conventional duplex outlet 100 including an upper outlet 102, a lower outlet 104, and a cover plate 106. The angular orientation of the prong assemblies (not visible) of the plugs 10a and 10b orients the elongated plug housings 12a and 12b at an angle with respect to the receptacle 100. Consequently the elongated housings 12a and 12b do not overlap or otherwise restrict access to the adjacent outlets. If the angle between the line 70 and the axis 30 (FIG. 2) were 90 degrees, the housings 12a and 12b would undesirably overlie the adjacent receptacle outlets. Conversely, if the line 70 and the axis 30 are parallel, the housings 12a and 12b will be oriented generally horizontally. The optimal range for the angle between the line 70 and the axis 30 is in the range of zero degrees to approximately forty-five degrees to prevent this overlapping problem. In any event, the circuit breakers 16a and 16b of the plugs 10i a and 10b, respectively, are readily accessible for resetting even when the plugs are in the outlets.
The present plug provides a low profile plug with an integral circuit breaker. The low profile enhances safety and the security of the plug within the receptacle. The integral circuit breaker enables power to be easily reestablished without accessing the fuse box or circuit breaker box through which the circuit is connected.
The above description is that of a preferred embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as set forth in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. | The specification discloses an injection-molded electric plug having an integral circuit breaker. The plug housing is molded directly onto the power cord and defines a circuit breaker chamber. A circuit breaker is slidably received within the chamber and retained therein by spring fingers. The housing is elongated and the prongs extend from one of the long sides thereof so that the housing lays substantially flat against a receptacle. The prongs are angularly oriented with respect to the elongated body so that the body will not overlie adjacent receptacle outlets. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present case is a continuation of application Ser. No. 11/749,705, filed May 16, 2007 now U.S. Pat. No. 7,561,887, which is a continuation of application Ser. No. 11/286,811, filed Nov. 22, 2005 and issued as U.S. Pat. No. 7,263,372 on Aug. 28, 2007. Application Ser. No. 11/286,811 is a continuation of application Ser. No. 10/323,450, filed Dec. 17, 2002, now U.S. Pat. No. 6,987,977, which is a continuation of application Ser. No. 09/452,768, filed Dec. 1, 1999, now U.S. Pat. No. 6,496,702. The entire disclosure of each of these applications is incorporated herein by reference, and priority is claimed to the filing date for the disclosure of each of these applications, including Dec. 1, 1999 of application Ser. No. 09/452,768.
The entire disclosure of copending application Ser. No. 11/456,796 is incorporated herein by reference. Application Ser. No. 11/456,796 is a continuation of application Ser. No. 10/899,528, now U.S. Pat. No. 7,079,641, which is a continuation of application Ser. No. 09/912,770, filed Jul. 24, 2001, now U.S. Pat. No. 6,788,779. The entire disclosure of each of these applications is incorporated herein by reference, and priority is claimed to the filing date for the first disclosure of each of these applications, including Jul. 24, 2001 of application Ser. No. 09/912,770.
The entire disclosure of copending application Ser. No. 11/388,089 is incorporated herein by reference. Application Ser. No. 11/388,089 is a continuation of application Ser. No. 09/661,181, now U.S. Pat. No. 7,020,264, which is a continuation of application Ser. No. 09/443,057, now U.S. Pat. No. 6,122,360, which is a continuation of application Ser. No. 08/968,825, now U.S. Pat. No. 6,005,931, which is a continuation-in-part of application Ser. No. 08/869,815, now U.S. Pat. No. 6,148,074, which is a continuation-in-part of application Ser. No. 08/802,667, now U.S. Pat. No. 6,201,863, which is a continuation-in-part of application Ser. No. 08/797,420, now U.S. Pat. No. 6,185,291, filed Feb. 10, 1997. The entire disclosure of each of these applications is incorporated herein by reference, and priority is claimed to the filing date for the first disclosure of each of these applications, including Feb. 10, 1997 of application Ser. No. 08/797,420.
The entire disclosure of copending application Ser. No. 10/406,347 is incorporated herein by reference, and priority is claimed to the filing date of Apr. 2, 2003 for the disclosure.
The entire disclosure of copending application Ser. No. 10/229,428 is incorporated herein by reference. Application Ser. No. 10/229,428 is a continuation of application Ser. No. 09/335,423, now U.S. Pat. No. 7,020,264. The entire disclosure of each of these applications is incorporated herein by reference, and priority is claimed to the filing date for the first disclosure of each of these applications, including Jun. 17, 1999 of application Ser. No. 09/335,423.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is in the field of telephony communication as it pertains to mobile devices or units operating on a private network and pertains more particularly to methods and apparatus for enhancing communication capability, data transfer capability, and increasing the number of mobile devices that can successfully operate on a communication-center facilitated virtual private network (VPN).
2. Description of Related Art
The field of telephony communication has grown more diverse and flexible. Call-in centers that once were restricted to connection-oriented switched telephony (COST) are now employing computer-simulated telephony techniques generally referred to as data network telephony (DNT). Call-in centers that are enhanced with DNT and multimedia capability more appropriately termed communication centers in the art. This is due to the broad range of telephony and data transfer capabilities that are routinely practiced within or facilitated by such centers.
Communication centers are often used by enterprises to accomplish cellular communication links with fleets of vehicles having wireless communication devices installed therein for receiving instruction and responding back to personnel operating within the center, such as dispatchers, sales agents and so on. There are a variety of existing techniques used by communication centers today to track, control and support fleets of vehicles.
Services such as Omnitracs™ operated by Qualcomm and On-Star™ operated by General Motors Corp. (GM) use the well-known cellular telephone infrastructure and the global positioning system (GPS) to track and support vehicles in the field. Services offered include such as air bag deployment notification, remote door unlocking, road-side service, vehicle theft notification, and so on. In some cases device-equipped vehicles are owned and operated by a single entity that also provides the service. In some cases vehicles are owned individually, or in small groups and are subscribed to a service.
A commonality among all of these types of service communication systems is that users (i.e. drivers of subscribed vehicles) may need to be periodically tracked by the system to be given logistics support, help or advice at some point during a trip. In some cases tracking is employed for reporting purposes to customers of the service business, such as with some trucking companies and the like. The above-described systems target mostly high-end vehicles or commercial fleets as primary targets, due to the higher value and traffic they incur.
One problem with the infrastructure associated with the above-described services is that communication with the volume of serviced cars or commercial fleet of vehicles is typically implemented by a single communication center. As a result the systems are limited to a relatively small volume vehicles depending on the nature of the service. Such a communication center, as is known in the art, simply cannot handle a really large volume, such as perhaps a million vehicles or more.
The technologies (GPS and cellular services) that support the above-described services are continually being developed and made available over ever-increasing geographic regions. Therefore, it is desirable to provide similar services to a much larger customer base than the currently limited numbers serviced by today's largest system/infrastructures. As previously described, a single communications center cannot handle the desired volume. For example, a service base of a million users or more would logically encompass mostly “normal citizens” rather than professional drivers due to shear volume. In this regard, services offered would have to be more diversified among users instead of being standardized as with a fleet of company-owned service vehicles.
An unacceptable communication load would result in any single communication center. Moreover, other problems would arise from an overload of users interacting with a center such as increased costs of long-distance routing, and lack of “local knowledge” required to effect many desired and marketable services.
What is clearly needed is a method and apparatus that enables efficient data management and routing of service events to and from a large volume of tracked vehicles maintaining wireless communication devices, wherein specific interaction and routing does not have to be performed in or facilitated by one single communication center. Such a system would allow a single service to provide cost-effective, mainstream services to millions subscribers.
BRIEF SUMMARY OF THE INVENTION
In a preferred embodiment of the present invention a service communication system for mobile vehicles is provided, comprising a cellular telephony interface in individual ones of the mobile vehicles, for establishing telephony events over a cellular network with a base station; a global positioning system in individual ones of the mobile vehicles for determining global position from transmissions from GPS satellites; a network of base stations for receiving and broadcasting to the mobile vehicles, and for bridging events between cellular and public switched telephone service (PSTN) protocol; a network-level routing system connected by first telephony trunks to the base stations and enabled to retrieve GPS position from the telephony events; and a plurality of service centers connected to the network-level routing system by second telephony trunks. The network-level routing system determines a destination for individual ones of the telephony events among the plurality of service centers according to the retrieved GPS position.
In preferred embodiments the network-level routing system further comprises an interactive voice solution (IVS) system for providing synthesized voice responses to incoming events. Also in preferred embodiments individual ones of the service centers each comprise a telephone switching apparatus connected by a computer telephony integration (CTI) link to a CTI processor for monitoring a controlling the connected telephone switching apparatus, and the network routing center comprises a network-level CTI processor connected to a network-level switch, and wherein the CTI processors at network and service center level are interconnected by a data link separate from the second telephony trunks. In some embodiments data about a call event is stripped at the network-level routing system and transmitted by the data link separate from the second telephony trunks to a service center to which the call event is routed.
In various embodiments of the invention taught in enabling detail below, services for mobile vehicles may for the first time be provided in a specialized way by having local service centers attuned to the needs of certain areas and for special purposes, and by routing service call events to specialized centers based on mobile vehicle location at the time service is requested.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is an overview of a mobile device communication network as known to the inventor illustrating typical routing points for a call event from a mobile device to a contact center.
FIG. 2 is an overview of the mobile device communication network of FIG. 1 illustrating typical routing points for incoming voice calls into the contact center of FIG. 1 .
FIG. 3 is an overview of the mobile device communication network of FIG. 1 illustrating typical routing points for a call event to a car from a PSTN through the contact center of FIG. 1 .
FIG. 4 is an overview of a mobile device communication network enhanced with network data control and routing control according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an overview of a current-art mobile device communication-network 9 as known to the inventor illustrating typical routing points for a call-event from a mobile device to a contact center. Communication network 9 comprises a Cell network 13 , which is in an area that has by in large also GPS coverage, a connected PSTN network 11 , and a communication center 15 . Cell network 13 represents the well-known cellular communications networks in an area with the well-known GPS system. These two technologies including their respective infrastructures are utilized by service communication centers such as center 15 to track and provide support to fleets of vehicles having both GPS devices and wireless communication devices installed therein. One vehicle of such a fleet of vehicles is represented herein by a car 25 illustrated within Cell network 13 and presumably with the GPS coverage.
PSTN network 11 may be another type of telephony network such as a private telephone network as may be known in the art. Communication center 15 , also referred to as a contact center in the art, represents in this example a national service center that offers support and service to a fleet of vehicles as was defined in the background section. Center 15 utilizes PSTN network 11 and Cell networks 13 to facilitate communication and interaction between center 15 and an equipped vehicle such as car 25 .
A network bridging (base) station 17 is provided and adapted in this example to convert wireless cellular calls into PSTN calls and PSTN calls into cellular calls. This shall be a grossly simplified view of elements as are well known in the art of telephony. Further details would obfuscate discussing the present invention and have hence been left out. Station 17 is equipped with all of the necessary hardware and software to accomplish this task as is known in the art. Station 17 has a transceiver/receiver device 19 connected thereto and adapted to pick-up and transmit cellular transmissions. Cellular communication from car 25 to center 15 , or from center 15 to car 25 is routed, in this example, through the PSTN network 11 .
Communication center 15 has installed therein a central telephony switch 33 , which may be an ACD or PBX type switch. Switch 33 is adapted to function as a first destination for inbound call events originating from such as car 25 , or from other sources within PSTN 11 . Switch 33 is CTI (computer telephony integration) enhanced by a CTI processor 35 connected thereto by a CTI link 37 . Such enhancement provides status and event monitoring of the switch, and switch function control, such as intelligent routing control. For example, switch 33 functions in this embodiment as a private service control point (SCP) with agent/system level routing intelligence for routing to various points within center 15 .
A modem pool 41 is provided and adapted to strip data from inbound and outbound call events processed at center 15 . Modem pool 41 is connected to switch 33 by an internal telephony trunk 55 , and to an internal, interconnecting local area network (LAN) 49 , which interconnects several internal elements as described below, including the CTO processor 35 . Modem pool 41 represents a second “data” routing point within communication center 15 .
An interactive voice solution (IVS) machine 43 is provided and adapted to interact with customer's calls and contacts, and to process certain aspects of data in incoming calls to synthesized voice, which may go to an agent or back to a subscriber's vehicle. IVS 43 connects on LAN 49 . In this way IVS 43 is controlled to respond to call events according to event protocols.
A front-end communication-center server (CCS FE) 45 is provided and adapted to process workflow for incoming non-real-time events. Server 45 is connected to CTI processor on LAN 49 and is controlled by processor 35 . A back-end communication-center server (CCS BE) 47 is provided and adapted to process workflow for non-real-time outgoing events. Server 47 is connected to server 45 and also to IVS 43 on LAN 49 .
An agent's telephone 50 is provided at an agent station and adapted to enable live voice communication between such as car 25 and an agent operating within center 15 . Telephone 50 is connected to switch 35 by internal telephone wiring 51 . In other embodiments, an IP phone may be used connected to a LAN (e.g. LAN 49 ). A communication queue 39 is provided in switch 33 for incoming call events that are waiting for pickup by an available agent such as one operating telephone 50 . It will be apparent to one with skill in the art that in a service communication center such as center 15 , there will be many more agents' telephones than the one telephone 50 illustrated herein. Moreover, agents may also be operating local area network (LAN) connected terminals at the agent stations, such as terminal 52 shown, having graphical user interfaces (GUI) along with processing and data input capabilities. Such terminals may be personal computers (PCs) or other adapted machines.
It is noted here that the equipment and connections illustrated within communication center 15 in this embodiment represent such as apparatus connection and control schemes known to the inventor and is not yet widely available in the art to be termed prior art. It will be apparent to the skilled artisan that there are alternative architectures that might be used for the interconnection of operational elements in the communication center.
As described in the background section, large commercial fleets, such as trucking fleets, as well as private subscribers operating private vehicles are facilitated in terms of GPS tracking and cellular support by a single national communication center. Such is the case represented here. Because of this only a limited number of vehicles, perhaps up to a few thousands, may be adequately serviced without severely straining the resources of a national center such as center 15 . Moreover, routing within a center such as center 15 may be somewhat complicated depending on the nature of events and services offered.
In this example a typical routing path is illustrated for a call event arriving to center 15 from car 25 . Such a call event may be an automatically triggered data request, a voice/data request, or a voice call. It is important to note here that the modem communication between such as modem pool 41 and a modem installed in car 25 follows such as Analog Display Services Interface (ADSI) protocols or equivalents. Hence, the connection has two states; one being a voice connection and the other being a data connection using an A/B toggle switch at each modem with control afforded to communication center 15 .
An inbound event is broadcast from car 25 , received by receiver/transceiver 19 and transmitted to station 17 where it is converted to a PSTN call. Typically, because of the nature of the subscription service, being highly dependent in many instances on the location of the vehicle originating an event, data regarding global positioning is sent with the call event. This data is available to the system in the vehicle by GPS interface which operates, as is known in the art, by monitoring transmission from multiple satellites, represented here by satellites 23 and 24 , and triangulation calculations. In some cases, because, for example, a vehicle having initiated an event continues to move, the position has to be updated, which may be done periodically as a function of the vehicle system, or may be triggered from a remote station. In any event, the GPS position information is transmitted via the cell network.
Once on PSTN 11 , the event is routed to switch 29 . The event is then switched to central switch 33 at the communication center at a first agent-level routing point I over telephony trunk 31 . Routing point I is a private SCP equivalent implemented at center 15 . Once the event reaches routing point I, the nature of the event is determined (ANI/DNIS). In this example, we assume the event is a data call requiring a non-real-time or automated response, and the GPS arrives with the call event. Call nature determination and further routing is controlled by CTI processor 35 running CTI software adapted for the purpose. It is important to note here that every inbound event is routed to a routing point II (modem pool 41 ) over trunk 55 . Routing point II, which is at modem pool 41 , strips the data from the event, including the GPS location of car 25 at the time of event initiation.
Also, certain data about the call may be passed to Customer Client-Server workflow engine Front End (CCS FE) server 45 over LAN 49 for front-end processing. Data about the event passes from server 45 to Customer Client-Server workflow engine Back End (CCS BE) server 47 for back-end processing. Processed data, which reflects the command disposition of the event, passes from server 47 into IVS 43 for processing, if required, into synthesized voice instruction, which will become part of an outbound event. The Voice package necessitated is passed to modem pool 41 and an outbound event is created and forwarded to a routing point III. Hence, an outbound call event representing a synthesized voice response to the original request is routed back over trunk 31 into switch 29 in PSTN 11 . The response event is then routed to station 17 over line 27 where it is converted back to a cellular protocol and broadcast by transceiver/receiver 19 to car 25 where a motorist receives it.
Returning to routing point III, if the original event required or requested a live agent communication, the caller would either be connected to an available agent at, for example, telephone 50 , or, if none were available, be placed in queue 39 . An agent at telephone 50 will typically have access as well to a computer station 52 having a video display unit (PC/VDU), and the system may provide display for the agent related to telephony events. However, the voice aspect of a live event is not connected until all data is stripped and processed. Communication center 15 , through server 35 , controls the voice/data aspect of each event.
Because communication center 15 in this example is a national center handling all subscribing vehicles nation wide, events may have to be routed over long distances through PSTN 11 to a local cell network. Another issue is that one national center such as center 15 may not be up to date on recent local changes transpiring in the vicinity of car 25 . For example, if the original request was for a list of local motel vacancies in the immediate area of car 25 , center 15 may not have the recent listings or information on any new locations just opened for business. If, for example, the original request was for an emergency towing service, a national center may not know that car 25 is only a few miles from a recently opened service and may recommend a more distant provider causing added expense for the motorist.
It will be apparent to one with skill in the art that a communication network, wherein a single national center must facilitate communication with a nationally spread-out fleet of vehicles, will have substantial limitations with respect to providing accurate knowledge of local resources and with providing routing of events over long distance wired networks.
FIG. 2 is an overview of the mobile device communication network 9 of FIG. 1 as known to the inventor illustrating typical routing points for an incoming voice call into the contact center of FIG. 1 . As the elements involved in this embodiment are analogous to those described in FIG. 1 , reintroduction of such elements will not be made.
In this embodiment, we assume that car 25 places a live voice call for an agent at communication center 15 . A voice call is initiated from car 25 using the voice mode on the associated modem. Initial call routing is analogous to FIG. 1 . For example, transceiver/receiver 19 picks up the event and passes it into station 17 where it is converted to a PSTN call. The event is then routed over trunk 27 to switch 29 in network 11 . Techniques typically using ANI/DNIS cause routing of the event over trunk 31 to switch 33 (SCP). At this point the voice nature of the call is determined, and the call is routed first to an available agent as a PSTN-connected call. Notification is given by the agent to the vehicle operator that he or she requires data communications with the vehicle and will be placed on hold for reconnection. This may be accomplished by a voice-synthesized message.
The event is then routed to routing point II (modem pool 41 ) and the agent operating telephone 50 is placed on hold. This process must be performed so that any data associated with the live call request may be stripped by modem pool 41 and processed, including obtaining a read on car location per the GPS system if necessary. Once the data is processed by servers 45 and 47 as described above with reference to FIG. 1 , the agent at telephone 50 is reconnected to the caller in voice mode. If the agent becomes unavailable while data is being processed, then the inbound call event may be routed to queue 39 to wait for reconnection to a different agent.
It will be apparent to one with skill in the art that internal routing wherein the modem at communication center 15 must be re-linked back into the call flow in order to complete a voice call is rather complicated and uses significant resources. The modem at communication center 15 must issue a dual-tone-multiple-frequency (DTMF) or other suitable non-DTMF tone to switch the connection-state from voice to data and then back to voice as is known in the art with ADSI type modem-interfaces. Moreover, as communication network 9 is identical to the one described in FIG. 1 , the same limitations apply that were described in FIG. 1 .
FIG. 3 is an overview of the mobile device communication network 9 of FIG. 1 illustrating typical routing points for a call event to a car from a PSTN from the contact center of FIG. 1 . In this example as in the example of FIG. 2 , elements of communication network 9 remain the same as previous embodiments and therefore, will not be reintroduced. The example provided herein represents the routing path associated with a PSTN call to car 25 in Cell network 13 .
A call event represented by a vector 30 arrives at switch 29 in PSTN 11 . ANI and DNIS information indicates that the event is destined to communication center 15 . It is assumed that in this embodiment center 15 , which is a national center, must facilitate the call. This is typical of services of the type described in the background section.
Event 30 is routed from switch 29 over trunk 31 to switch 33 at communication center 15 . Because it is a conventional PSTN call, it may be routed directly to an agent (routing point II) such as one operating telephone 50 . The agent operating telephone 50 may further direct the call based on information supplied by the caller such as car identification number. In some cases a car identification number may be part of the call identification data. Based on the call data and agent input data, event 30 is routed back to switch 33 as an outbound call to car 25 . This employs the workflow process represented by servers 45 and 47 along with IVS 43 which instructs modem pool 41 to dial car 25 . Therefore, a third routing point is at switch 33 , which represents an outbound call in progress. The agent operating telephone 50 may or may not stay with the caller during this process. The outbound call is routed back through PSTN 11 , through bridging station 17 and onto car 25 through Cell network 13 . When the motorist operating car 25 picks up; he is connected to the waiting PSTN event.
It will be apparent to one with skill in the art that limitations exist with respect to communication network 9 described in FIGS. 1-3 including routing complexity, long distance costs, lack of local knowledge to aid motorists, and so on.
The above FIGS. 1-3 describe a current-art communication network that uses the GPS system and the cellular network along with the PSTN to enable national centers such as center 15 to communicate with motorists and on-board systems that may be associated with a subscribed car such as car 25 .
A communication network such as network 9 may utilize a virtual private network (VPN) comprising multiple wireless carriers and land networks as is known in the art. Therefore, networks 13 and 11 may be assumed to represent multiple wireless and land-line networks spread over large geographic areas. Even with VPN access, which limits some long distance charges, routing to one national center such as center 15 is still complicated.
FIG. 4 is an overview of a mobile device communication network 61 enhanced with network data control and routing control system 63 according to an embodiment of the present invention. New elements are introduced in this preferred embodiment. Such elements provide enhancement to overall performance and efficiency for the entire system.
In this example, instead of utilizing one single, national communication center to facilitate communication as is illustrated in current-art examples with reference to FIGS. 1-3 , the inventor illustrates a unique and novel network system 61 , which uses multiple, distributed communication-centers, illustrated herein as centers 71 and 73 , and places data control and voice/data switching capability at the network level, illustrated by a VID packet 63 . For clarity, not all the elements explained before are shown in the drawing but may or may not be present in each one of the centers.
Communication center 71 comprises a central switch 75 , a modem pool 77 , a CTI processor 81 , a representative telephone 83 , and a representative PC/VDU 84 . The separate elements are connected through a LAN 86 , and a trunk 79 connects switch 75 to modem pool 77 . IVS and CCS implementations as shown in communication center 15 of FIGS. 1-3 may be assumed to be present, but are not shown. Communication center 73 is in this embodiment is identical to center 71 , comprising a central switch 89 , a modem pool 91 , a CTI processor 95 , a representative telephone 97 , a representative PC/VDU 97 , a LAN 100 , and a trunk 93 . In center 71 , switch 75 is connected to CTI processor 81 by a CTI link 87 . Modem pool 77 is connected to switch 75 by internal telephone wiring 79 . Telephone 83 is connected to switch 75 by internal telephone wiring 85 . In center 73 , switch 89 is connected to CTI processor 95 by a CTI link 101 . Modem pool 91 is connected to switch 89 by internal telephone wiring 93 . Telephone 97 is connected to switch 89 by internal wiring 99 .
Centers 71 and 73 represent local distributed communication service centers provided by an enterprise hosting a mainstream service and therefore may be significantly smaller in size (number of agents, modems, workstations, etc.) than one large national center. An object of the present invention is to provide distributed centers such as centers 71 and 73 to allow for a much higher service capability (number of vehicles) than is possible with current art systems.
VID packet 63 is provided and operates at PSTN network level. Packet 63 is in this example is an equipment grouping that handles GPS, voice/data switching, and workflow processing activity, which was in previous examples provided within a national communication center such as center 15 of FIGS. 1-3 . Packet 63 comprises a modem pool 65 , an IVS machine 67 , and a CTI processor 69 . CTI processor 69 is connected to switch 29 by a CTI link 68 . This connection provides CTI monitoring and control over switch 29 such that it may be used in many enhanced ways, including as a private SCP. By placing VID packet 63 in the network, GPS location data may be utilized at the network level instead of from within a communication center. Voice and data switching and interactive voice/data control is also performed at network level by modem pool 65 and associated IVS 67 .
In a preferred embodiment of the present invention, an inbound call event from car 25 is received at a local bridging station such as station 17 by way of transceiver/receiver 19 and is converted to a PSTN call event as was described in previous examples. It is assumed for this example that the incoming call event includes data for GPS position. In some embodiments there may be a function for updating position by automatic pinging back through the system to the vehicle. The call event arrives at switch 29 over trunk 27 also as previously described. Here the similarity ends with respect to previously described routing means and data handling.
Data from such a call event is passed over data-network connection 68 to processor 69 in VID packet 63 . The call event is routed to modem pool 65 over trunk 66 . Modem pool 65 represents a routing point I, which is a pre-center routing point. GPS location data associated with car 25 is accessed by modem pool 65 . Data about the call event is stripped by modem pool 65 and processed by IVS 67 . By utilizing VID capability at the network level, now the inbound call event from car 25 may be routed to either center 71 or center 73 (or another call center) whichever is more appropriate. In many cases the appropriate center will be the closest center to car 25 , and the GPS data may be used to make the routing decision. An event such as an inbound event sourced from car 25 arrives at either center 71 or 73 by way of telephony trunk 72 out of modem pool 65 in the network. Other items may be used in considering the routing, as are well known in agent skill level routing, customer requirement routing etc.
Routing points II illustrated at switch 75 (center 71 ) and switch 89 (center 73 ) are optional routing points depending on which center will be designated to receive the inbound event. Data about the inbound event is passed to the appropriate communication center over a separate data network represented by path 70 connecting processors 69 , 81 and 95 . Processors 81 and 95 control further routing, at centers 71 and 73 , respectively.
Now GPS location is available as a determinant in routing to various call centers. This position information has other novel uses as well. Data processing and voice/data switching is performed at network level according to CTI routines for inbound events. Therefore, the ratio of modems to agents at each center may be significantly reduced. Call events arriving from anywhere in PSTN 11 may also he handled at network level. Modem pools 71 and 73 handle outbound traffic in normal fashion as well as providing voice/data switching.
The method and apparatus of the present invention may be integrated into existing VPN networks without departing from the spirit and scope of the present invention. In this way, multiple wireless carriers as well as land connections may be utilized in routing. Inbound events are routed intelligently by virtue of processors 69 (network), 81 (center 71 ), 95 (center 73 ), utilizing a separate data network illustrated by network connections 68 and 70 . As a result, inbound routing decisions may be based on a variety of criteria such as load balancing requirements, statistical routing, routing according to least expensive path, routing according to defined service, routing by agent skill, and so on.
In one embodiment of the present invention, a wide area network such as the Internet packet-data network may be utilized and integrated as a data/voice carrier. For example, an Internet-based service may be available for owners of subscribed vehicles to plan such as vacation trips or the like. Such data may be configured and uploaded to an Internet server and tagged to a particular vehicle. At the time of the trip the plans can be included in a series of inbound data calls to such as car 25 from the Internet. Of course, the appropriate DNT/PSTN bridge is required in order to interface switch 29 with the source data events.
GPS may also be used to trigger portions of a trip plan to be broadcast to car 25 . For example, car 25 reaches a certain point (GPS location, latitude or longitude as more broad lines along the planned trip route). Periodic pinging of the GPS system may be used to approximate the correct location of car 25 along a route. When such location data closely matches data included in the trip plan, an automated data call from the Internet carrying the appropriate data for the matching location would be processed as an inbound call event to the appropriate communication center. That center could then generate an outbound data call to car 25 that may include locations and directions for local motels, restaurants, banks, supermarkets, camp sites, and so on. There are many possibilities. Businesses and service providers such as auto towing, truck stops, rest areas, and the like may advertise to customers through local centers.
In some cases, the location of a requested service may effect network-level routing of an inbound call request. For example, if during travel, a subscriber such as one driving car 25 requests knowledge of a nearest hospital that provides emergency services, then a network-level SCP may, after pinging for GPS position, route the event to a local communication center known to have knowledge of a name, location and directions to a nearest hospital that matches the request. Such data would, of course, have to be known at network level such as by a connected data repository adapted for the purpose.
It will be apparent to one with skill in the art that a communication/service network such as network 61 can provide service to more vehicles by virtue of utilizing multiple communication centers than can be handled by a single communication center. It will also be apparent to one with skill in the art that such multiple centers as described above can provide more specific and updated information by virtue of being in close vicinity to the services requested, and local centers may be specialized to local services, and so on.
The methods and apparatus of the present invention may be practiced over standard Cell/PSTN networks or may be integrated into a VPN comprising multiple carriers. Likewise integration into such as the Internet or other WAN or G3-type digital networks is possible. Therefore, the method and apparatus of the present invention should be afforded the broadest scope. The method and apparatus of the present invention is limited only by the claims that follow. | A communication system has a cellular telephony interface in individual ones of two or more mobile vehicles, a position determination system in individual ones of the mobile vehicles, a network of cellular base stations coupled to the mobile vehicles, individual base stations coupled to one or both of a packet-switched or a line-switched telephony system, a router coupled to the base stations and enabled to retrieve GPS position from the telephony events, and a plurality of service centers coupled to one or both of the telephony systems. Telephony events from individual ones of the mobile vehicles are routed according to position reported by the position determination system. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 10/172,047, filed Jun. 14, 2002 now abandoned.
The invention relates to an access cannula for endoscopic operations, in particular for arthroscopy.
Access cannulas for endoscopic operations are generally known.
In minimally invasive operating techniques, whose application is becoming ever more widespread, such an access is provided using a trocar. A trocar has a sleeve-like or cannula-like hollow tubular body which is introduced into the body, for example through the abdominal wall, in order to perform operations within the peritoneal space. Suitable instruments, for example endoscopes, are then guided through the trocar in order to be able to visually monitor the operation being performed inside the body.
To bring the trocar in place, a pointed trocar mandrel or core rod is inserted into the trocar sleeve and a skin incision is made in order to introduce the access cannula, in this case the trocar sleeve, into the body.
In minimally invasive operations on soft tissue parts, for example through the abdominal wall, the trocar can be introduced exactly in the required size.
But it is much more difficult to create an access in arthroscopic procedures. If a minimally invasive endoscopic operation is to be performed in a joint, the spaces between two bones forming a joint are often very small, with the result that a trocar cannot easily be fitted using the technique described above.
It is often desirable or even necessary to arrange a plurality of access cannulas in the operating field in order either to observe the operating field from a plurality of directions or to obtain an access to the joint from a plurality of directions.
A further problem is that, to permit better viewing of the operating site through the access cannula, gases and/or liquids are introduced in order to slightly expand the body in the operating site by means of overpressure. Irrigation fluids are often also passed through the access cannula. To prevent body fluids, gases or irrigation fluids from running out from the proximal end of the access cannula, a valve is usually provided there which, on the one hand, ensures a tight closure of the cannula tube but, on the other hand, also provides for the possibility of pushing instruments or endoscopes through the valve. Various configurations of valves with flaps or with slit seals are known for this purpose.
On account of the aforementioned widespread application of minimally invasive surgery, a large number of access cannulas are required which then have to be properly cleaned and sterilized after the surgery, which necessitates the use of high-quality materials.
It is therefore the object of the present invention to make available an access cannula for endoscopic operations which permits different operating methods and different possibilities of bringing the cannula in place, and which can be produced inexpensively, but nevertheless functions effectively and safely during the intervention.
SUMMARY OF THE INVENTION
The object is achieved by an access cannula which has a cannula tube and a valve housing, which valve housing can be connected releasably to one end of the cannula tube, said valve housing having a valve which ensures a tight closure of the cannula tube at the end but allows instruments to be passed through the cannula tube, and wherein said valve housing is designed as an entire valve body unit, which entire unit is releasable connected to the cannula.
It is now possible, with one and the same valve body unit, to combine different cannula tubes which are best suited for the particular operating technique. At the same time, this affords the possibility of initially inserting just the cannula tube, and only later securing the entire valve body unit to the latter. This also makes it possible to fit a plurality of cannula tubes which lie close to one another, and are of a very slender construction, without the relatively voluminous valve body being present at the same time. A very high degree of flexibility is thus obtained. It is only when the actual operation is performed, that is to say after the preparation involving placement of the access cannula, that the valve body unit need be connected to the cannula tube and thus ensure a tight closure of this end of the cannula tube. The instruments, for example endoscopes or surgical instruments, can then be pushed through the valve body itself.
Increased flexibility is also achieved by the fact that other instruments can also be attached for a time to the cannula tube, for which purpose the entire valve body unit is simply removed and an instrument, e.g. a viewing optic or the like, can be attached for a time.
It is therefore also possible, depending on the objective and on the operating technique, to arrange different cannula tubes on a single type of a valve body unit which has standardized couplings for other instruments.
This not only increases flexibility but also ensures a considerable reduction in cost and guarantees a perfect sealing. The releasable connection between valve body unit and cannula tube can be effected in different ways, for example by means of a screw connection, a bayonet lock, a snap-fit connection, etc.
In a further embodiment of the invention, the valve housing is designed as a sterilizable component part which can be used a number of times.
This measure has the advantage that the aforementioned configuration affords the possibility of producing the valve housing as a high-quality component part, for example made of medical grade steel, which can be sterilized and can be used a number of times.
In a further embodiment of the invention, the cannula tube is designed as a disposable component part.
This measure, in particular together with the aforementioned measure, has the advantage that the cannula tube can be produced as an inexpensive disposable part for single use, to which the reusable valve body unit can then be coupled.
In a further embodiment of the invention, the valve is designed as a double-disk valve.
This measure has the advantage that, by means of the double-disk construction, an instrument has to be guided through two disks, which ensures particularly reliable sealing.
In a further embodiment of the invention, a slit seal is provided in each disk.
This measure has the advantage that instruments of different diameter can be guided through, with a tight closure being ensured in each case. This is especially the case because the valve is designed as a double-disk valve.
In a further embodiment of the invention, the slits are designed in a star shape, and the slits of the two disks are offset in relation to one another.
This measure contributes still further to the excellent tight closure.
In a further embodiment of the invention, the two disks are connected to one another via an elastic bridge.
This measure has the considerable advantage that the double-disk valve consists only of one component part.
In a further embodiment of the invention, locking means are provided on the disks and serve to lock the disks onto one another.
This measure has the advantage that the double-disk valve can be produced as a body which extends in one plane and in which the two disks are connected to one another via the bridge and, for assembly, are turned back and placed one upon the other, by bending the bridge, and are then held firmly on one another by the locking means.
In a further embodiment of the invention, the valve housing is designed in two parts, and the valve can be arranged between the two parts.
This measure has the advantage that the valve is held in the valve housing by structurally simple means. This measure also permits simple dismantling of the valve housing for cleaning and sterilizing.
In a further embodiment of the invention, the valve housing has a main body which has a neck for releasable connection to the cannula tube and moreover has a recess into which the valve can be inserted, the valve being fixed via a clamping ring.
This measure has the advantage that the main body of the valve housing and the clamping ring can be made from high-quality special steel materials, whereas the interposed valve can be made as a disposable part. For this reason, only these two parts need to be sterilized, and a new valve can be inserted after sterilization.
This increases the versatility still further and also contributes to a cost reduction. In this case, both the cannula tube and the valve can be designed as a disposable part, and only the two-part valve housing is made of high-quality and precision-finished materials.
In a further embodiment of the invention, the cannula tube has, at the distal end, a ring which widens conically in the proximal direction.
This measure has the advantage that the cannula tube can be pushed via this ring into the joint, specifically in arthroscopic operations, and secured against removal or inadvertent loosening during the operation since the distal tip with the conical ring is as it were snapped into the joint.
In a further embodiment of the invention, the cannula tube is designed as a component part of a trocar device.
This measure has the advantage that it permits a flexible attachment to different trocars, for example for adults, for children, for thin and for thickset individuals.
In a further embodiment of the invention, the trocar device has a mandrel with a hand grip and also a core rod, which mandrel can be introduced into the cannula tube.
This measure has the advantage that the access cannula is designed as it were as a trocar sleeve which is introduced into the body together with the mandrel and core rod.
In a further embodiment of the invention, the cannula tube is designed as a component part of a dilatation device.
This measure has the considerable advantage that, upon access, dilatation can be performed without causing trauma. For example in arthroscopic operations, a first access is initially made with very thin cannulas, this access is then widened by pushing on dilatation rods of ever increasing diameter, and, finally, the access cannula according to the invention is fitted as an operating cannula which remains in the body.
For this purpose, the dilatation device particularly advantageously has a puncture needle, a guide wire, at least one dilatation mandrel for attachment onto the guide wire, the cannula tube being designed in such a way that it can be pushed onto a dilatation mandrel.
This arrangement is of advantage particularly in terms of the atraumatic placement of the cannula tube for an arthroscopic operation, this versatility having an especially favorable effect in this case. The guide tube can be pushed onto the dilatation mandrel again by means of the mandrel provided with a hand grip.
It will be appreciated that the features mentioned above and those still to be discussed below can be used not only in the respective combination mentioned but also in other combinations or in isolation, without departing from the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described and explained in greater detail below on the basis of a number of selected illustrative embodiments and with reference to the attached drawings, in which:
FIG. 1 shows a longitudinal section through an access cannula according to the invention, consisting of cannula tube and valve body unit, in an exploded view;
FIG. 2 shows a cross section through the valve body unit, turned through 90° about the axis of the cannula tube;
FIG. 3 shows a perspective view of the valve incorporated in the valve housing;
FIG. 4 shows the double-disk valve from FIG. 3 in the opened-out state before being fitted in the valve housing;
FIG. 5 shows a corresponding perspective view of the valve turned through 180°;
FIG. 6 shows a longitudinal section, corresponding to FIG. 1 , of the cannula tube and valve body unit when fitted together;
FIG. 7 shows a mandrel, with hand grip, of a trocar device;
FIG. 8 shows a core rod of a trocar device which is intended to cooperate with an access cannula according to the invention in FIG. 6 ;
FIG. 9 shows the component parts from FIGS. 6 , 7 and 8 when fitted together;
FIG. 10 shows a puncture needle of a dilatation device;
FIG. 11 shows an inner part of the puncture needle from FIG. 10 ;
FIG. 12 shows a guide wire which can be pushed into the puncture needle in FIG. 10 ;
FIG. 13 shows a dilatation mandrel and handle which can be pushed over the guide wire from FIG. 12 ; and
FIG. 14 shows an assembly consisting of the access cannula from FIGS. 1 and 6 , with a mandrel from FIG. 7 inserted therein, so as to be pushed over the dilatation mandrel from FIG. 13 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
An access cannula shown in FIG. 1 is provided overall with the reference number 10 .
The access cannula 10 consists of a cannula tube 12 and of a valve body unit 14 .
The cannula tube 12 has a tube 16 at whose distal end a conical ring 18 is provided as nose. The conicity is chosen such that the ring 18 widens as viewed from distal to proximal.
A shoulder 20 is thus created at a distance from the distal end. This ring 18 serves to be driven into a body opening, for example into a joint, and is then locked therein in order to secure against removal of the cannula tube 12 .
Provided in the area of the conical ring 18 , in the lateral wall, there is a through-opening 22 which serves to permit pressure compensation with the environment during operations. At the end 23 remote from the conical ring 18 , the tube 16 is provided with a collar 24 of greater diameter which has an internal thread 26 .
The valve body unit 14 is designed as a two-part valve housing. One part is provided by a main body 28 from one side of which there protrudes a tubular neck 30 , which is provided with an external thread 32 . The external thread 32 is configured such that it can be turned into the internal thread 26 in the collar 24 of the tube 16 . The clear internal diameter of the neck 30 corresponds to the clear internal diameter of the tube 16 . Protruding laterally from the main body 28 there is an attachment piece 34 which is closed by a cap 36 . This lateral attachment piece 34 is used to deliver fluids or gases laterally via the valve body unit 14 to the tube 16 or to remove them from it.
A valve 40 is arranged in the valve body unit 14 , proximally of the lateral attachment piece 34 . The valve 40 thus ensures a tight closure of the valve body unit 14 in the proximal direction and of the cannula tube 12 when the valve body unit 14 is connected to it via the screw connection.
The valve 40 in this case consists of a double-disk valve 42 , as can be seen in particular from FIGS. 2 through 5 .
The double-disk valve 42 has two disks 44 and 46 , each surrounded by a ring 45 and 47 , respectively. A star-shaped slit 48 , 50 with three arms is provided in each disk 44 , 46 respectively. The material of the double-disk valve is a rubber-elastic synthetic material so that, despite the presence of the slits 48 and 50 , a tight closure is guaranteed by each disk 44 and 46 .
The two rings 45 and 47 are connected to one another via a flexible bridge 52 . From the perspective views in FIGS. 4 and 5 , it will be seen that the slits 48 and 50 are cut so as to be offset in relation to one another.
As will be seen in particular from FIG. 4 , a stud 54 projects from each disk and can be fitted into a corresponding opening 56 on the other disk, in order to provide locking means on the disks serving to lock the two disks one to another.
The double-disk valve 42 , in the configuration represented in FIGS. 4 and 5 , can thus be produced as a shaped part or punched-out part, and it is later brought into the position shown in FIG. 3 by bending it about the bridge 52 .
The valve 40 is inserted into a recess 58 in the main body 28 of the valve body unit 14 , the latter having a lateral slot opening 60 from which the bent bridge 52 can laterally extend. The valve 40 is held on the valve body unit 14 via a clamp ring 62 , which provides a second part of the two-part valve housing. The clamp ring 62 is provided with an external thread which can be turned into an internal thread (not specifically shown) in the recess 58 . The clamping ring 62 then presses the two rings 45 and 47 of the disks 44 and 46 tightly against one another so that a tight closure of the valve body unit 14 is guaranteed by the valve 40 as a whole. The two parts, i.e. main body 28 and clamp ring 62 , provide the two-part valve housing.
Inside the valve body unit 14 there is a through-opening 64 whose clear internal diameter is greater than the clear internal diameter of the tube 16 , so that for example instruments, e.g. endoscopes or the like, can then be attached to the valve body unit 14 .
In FIG. 6 , the access cannula 10 is shown in the assembled state, i.e. the valve body unit 14 is mounted in place and ready, i.e. the valve 40 is fitted, and the valve body unit 14 is screwed via its external thread 32 on the neck 30 into the internal thread 26 on the collar 24 of the cannula tube 12 .
In this state, the access cannula 10 can for example be a structural part or component part of a trocar device 70 , as is shown in FIGS. 7 and 8 .
The trocar device 70 thus has a mandrel 72 and a core rod 73 which has a sharpened tip 74 .
The mandrel 72 has a hand grip 78 from which a tubular sleeve 76 projects.
The external diameter of the sleeve 76 is chosen such that this corresponds to the clear internal diameter of the tube 16 of the access cannula 10 .
The trocar device 70 is shown in its assembled state in FIG. 9 , i.e. the core rod 73 is pushed into the sleeve 76 of the mandrel 72 , and this assembly is in turn pushed into the cannula tube 12 .
From the view in FIG. 9 , it will be seen that the tip 74 extends slightly beyond the sleeve 76 , and the latter in turn extends beyond the conical ring 18 and is provided with a corresponding conical bevel. This results in the insertion end of the trocar device 70 having a pointed cone shape.
To insert the access cannula 10 , which now functions as a trocar sleeve, the core rod 73 is applied to a skin incision and pushed into the body, and the whole assembly in FIG. 9 is driven to the desired depth into the body. The hand grip 78 facilitates this procedure. Mandrel 72 and core rod 73 are then removed. By virtue of the valve body unit 14 with the closed valve 40 , it is possible to prevent the escape of body fluids or the like.
It is also possible to initially insert the cannula tube 12 into the body without having the valve body unit 14 mounted, and to screw the valve body unit 14 later onto it.
As has already been described, it is also possible to drive the assembly, as shown in FIG. 6 , into place and, after removal of mandrel 72 and core rod 73 , if necessary to remove the valve body unit 14 for a short time in order, for example, to fit a second access cannula in the immediate proximity.
This affords a particularly high degree of versatility.
After removal of the access cannula 10 , the valve body unit 14 can be dismantled, cleaned and sterilized, and, depending on its design, the double-disk valve 42 can likewise be cleaned and reinserted or can be replaced by another one.
Depending on its design, the cannula tube 12 can also be cleaned and sterilized, or it can also be made as a disposable part and discarded after the operation. The cleaned, sterilized and reassembled valve body unit 14 can then be again connected to a cannula tube 12 .
FIGS. 10 to 14 show another possible use of the access cannula 10 according to the invention, involving an access for an arthroscopic operation, for example an operation on a shoulder joint. For this purpose, the puncture needle 82 shown in FIG. 10 is placed at the location where access is required between two bones of the joint. The diameter of the puncture needle 82 is extremely small and is in the range of approximately 1.5 mm.
The needle is advanced through the skin and into the joint until the needle tip can be detected by an arthroscope.
An inner part 84 extends through the puncture needle 82 which is designed as a hollow needle.
After inserting the puncture needle 82 into the joint, the inner part 84 is removed and a guide wire 86 is pushed fully into the puncture needle 82 .
The puncture needle 82 is then removed, and the guide wire 84 now extends in the body or joint.
After making a skin incision, a dilatation mandrel 88 is placed on the guide wire 86 and for this purpose, as is shown in FIG. 13 , is connected to a hand grip 92 . The connection between hand grip 92 and dilatation mandrel 88 is effected via a locking screw 94 . Depending on the expansion diameter which is desired, one or more dilatation mandrels 88 of ever increasing diameter are pushed on.
In the illustrative embodiment shown, only the dilatation mandrel 88 is initially pushed onto the guide wire 86 and pressed into the joint, this being made easier by the conical tip of the dilatation mandrel 88 .
The external diameter of the dilatation mandrel 88 corresponds to the clear internal diameter of a sleeve 76 of a mandrel 72 which is in turn inserted into the tube 16 of an access cannula 10 according to the invention.
This assembly is shown in FIG. 14 .
After placement of the dilatation mandrel 88 , the hand grip 92 is removed by releasing the locking screw 94 , and the assembly in FIG. 14 is pushed over the dilatation mandrel 88 . The access cannula 10 is again pushed in until its conical ring 18 has snapped into or locked in the joint. To do this, considerable forces have to be applied, and the hand grip 78 makes it possible to do this safely in particular because of its easy-to-grip shape.
The dilatation mandrel 88 and the mandrel 72 are then removed, and only the access cannula 10 shown in FIG. 6 is left in the body. The actual surgical intervention can then be performed by guiding the appropriate instruments through the cannula. | An access cannula for endoscopic operations comprises a cannula tube, a valve body unit having a valve housing and a valve mounted in the valve housing. The valve body can be connected releasably as a completely assembled valve body unit to one end of the cannula tube. The valve of the valve body ensures a tight closure of the cannula tube at said one end, but allows an instrument to be passed through the valve body unit and the cannula. | 0 |
FIELD OF THE INVENTION
[0001] This invention relates generally to birefringent crystals, and more particularly, to a temperature-stabilized birefringent crystal for use in stable, temperature-independent birefringent crystal interferometers.
BACKGROUND OF THE INVENTION
[0002] Interferometers form the basis of a number of important communications devices including interleavers, dispersion compensators, and periodic filters. The basic function of an interferometer is to split coherent light into two paths with possibly different propagation delays and then to recombine the light from these two paths.
[0003] If the coherence length of the light source is longer than the difference in the path lengths on the two arms, interference of the two optical signals at the output provides a sensitive measure of the difference in the propagation delays on the two arms. If the frequency of the input light source is swept, the interferometer reveals a periodic transmission with a frequency period of
v o = c n 1 l 1 - n 2 l 2 ( 1 )
[0004] where c is the speed of light in free space, n i and l i are the optical index and physical path length of the two arms i=1,2. This quantity is typically referred to as the interferometer free spectral range (FSR).
[0005] To provide stable operation, both n i l i products must be stable to much better than one wavelength of light. At optical communications wavelengths, this leads to a stability requirement on the order of 10 nm, which is difficult to maintain. It is known in the art that a birefringent crystal interferometer (BCI) can be designed to provide such stable path lengths.
[0006] In BCIs comprising uniaxial birefringent crystalline material, the two “paths” are simply the optical paths of the two orthogonal linear polarizations propagating through the material. Since one polarisation experiences the extraordinary refractive index, n e , and the other the ordinary refractive index, n o , the path difference, also known as the retardance, is given by Δnl, where the birefringence, Δn, is given by n e −n o for a material having positive dielectric anisotropy. The interferometer FSR is now given by:
v o = c Δ nl ( 2 )
[0007] Since l 1 =l 2 =l automatically, only changes in the birefringence, Δn, and the total crystal length, l, can affect the operation of the interferometer. In fact, changes in temperature modify both of these properties, to an extent characterised by the physical parameters of thermo-optic coefficients (in fact, the difference of the two thermo-optic coefficients relating to n o and n e ) and the coefficient of thermal expansion (CTE) in the direction of light propagation.
[0008] One solution to the temperature dependence has been proposed by Kuochou Tai et al. in copending application Ser. No. 09/476,034, to the same assignee. Kuochou Tai et al. teach cascading two crystals of different material in such a way that the two crystal BCI is independent of temperature. For example, an appropriately selected Yttrium ortho-Vanadate (YVO 4 ) crystal followed by an appropriately selected rutile (TiO 2 ) crystal provides an interferometer that is stable to both thermal and mechanical perturbations.
[0009] However, the proposed method has several disadvantages.
[0010] First, it is difficult to manufacture both crystal lengths with sufficient accuracy. To overcome this limitation, pairs of crystals are picked so that the combination has the desired FSR.
[0011] Second, although this pair of crystals is selected to have the desired FSR and to be temperature stable, they typically do not resonate precisely at the optical frequency of interest (typically a channel on the ITU grid). To adjust the resonant frequency of the interferometer, the current practice is to add a thin piece of quartz (typically in the range of 180 to 210 microns). Accordingly, each crystal pair must be measured and an appropriate quartz piece selected to adjust the resonant frequency.
[0012] Finally, if during mounting, one of the crystals is rotated relative to the other, it is possible for the effective length and/or the effective indices of refraction (and hence effective birefringence) to change, introducing undesirable changes into the FSR and its temperature dependence.
[0013] It is an object of this invention to provide a birefringent crystal whose retardance is independent of temperature, for use in a thermally stable BCI that obviates the disadvantages of prior art.
[0014] It is a further object of this invention is to provide an optical retardance system that can be used in a stable, temperature independent BCI for use in interleavers, periodic filters, and/or dispersion compensators.
SUMMARY OF THE INVENTION
[0015] The instant invention relates to a stable, temperature-insensitive birefringent crystal interferometer (BCI) that uses a single variety of crystal and that can be used in an interleaver, a periodic filter, and/or a dispersion compensator. In comparison to BCIs that use two crystal varieties, the resulting device is cheaper, more robust, and has better performance.
[0016] In accordance with the invention there is provided an optical system comprising: a first block of light transmissive uniaxial birefringent material having an input port and an output port, the material having a first retardance at a first temperature; and, straining means for inducing a strain in one of the first block and a second block of light transmissive material optically coupled to the first block, the strain induced for maintaining a second net retardance substantially unchanged from the first retardance at at least a second other temperature.
[0017] In accordance with the invention there is further provided a method for compensating a thermal drift of a birefringent material comprising the steps of: providing a first block of light transmissive birefringent material having a first retardance at a first temperature; and, maintaining a net retardance substantially equal to the first retardance at a second temperature by applying a stress to one of the first block of light transmissive birefringent material and a second block of light transmissive material.
[0018] In accordance with the invention there is further provided a method for compensating a thermal drift of a birefringent material comprising the steps of: providing a light transmissive element having a net retardance at a first temperature, the light transmissive element comprising a block of the birefringent material; and, maintaining the net retardance of the light transmissive element at a second other temperature by inducing a strain in at least part of the light transmissive element.
[0019] Conveniently, the term “net retardance” as used herein, refers to the net or total retardance in the spectral region of desired device operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Exemplary embodiments of the invention will now be described in conjunction with the drawings in which:
[0021] [0021]FIG. 1 is a schematic diagram of a prior art arrangement of a YVO 4 crystal, a TiO 2 crystal, and a SiO 2 plate for use in thermally stable birefringent crystal interferometer (BCI);
[0022] [0022]FIG. 2 a is a schematic diagram of a single birefringent crystal for use in thermally stable BCI in accordance with the instant invention;
[0023] [0023]FIG. 2 b is a schematic diagram of a single birefringent crystal and a glass block for use in a thermally stable BCI in accordance with the instant invention;
[0024] [0024]FIG. 3 is a schematic diagram showing an optical element in close contact with a mount having a different thermal expansion than the optical element for providing means for stress-induced birefringence in the optical element;
[0025] [0025]FIG. 3 a is a cross-sectional view of a bimetallic mount and optical element;
[0026] [0026]FIGS. 4 a and 4 b are graphs showing the dependence of strain (S) on temperature (T) in accordance with the instant invention;
[0027] [0027]FIG. 5 is a schematic diagram showing the optical element and mount in FIG. 3 disposed such that an amount of stress-induced birefringence is varied by changing an interaction length between the optical element and the mount;
[0028] [0028]FIG. 5 a is a schematic diagram showing the optical element and mount in FIG. 5, wherein the optical element is movable relative to the mount; and
[0029] [0029]FIG. 5 b is a schematic diagram showing the mount in FIG. 5 being constructed from two different metals.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Referring to FIG. 1 there is shown a prior art optical system for use in a birefringent crystal interferometer (BCI) having two varieties of birefringent crystals. A first YVO 4 birefringent crystal 10 is disposed adjacent a second TiO 2 birefringent crystal 20 . The composition and length of each birefringent crystal is selected to have a predetermined free spectral range (FSR) and to provide thermal stability. A quartz (SiO 2 ) plate 30 is disposed adjacent the second birefringent crystal 20 to adjust the resonant frequency of the interferometer by a small amount. Light is shown to propagate from left to right. Typically, the c axis of the crystal is in the plane perpendicular to the optical path.
[0031] Turning to FIG. 2, there are shown two different embodiments of an optical system 100 for use in a birefringent crystal interferometer in accordance with the instant invention, having a single variety of birefringent crystal 110 . Superior temperature stabilizing and frequency tuning of the BCI is accomplished by virtue of the elastooptic effect, wherein the birefringence of a material is changed by inducing a strain in the material. In the instant invention, the birefringent crystal is temperature-stabilized by inducing a strain in one of the crystal and another optical element optically coupled to the crystal.
[0032] Referring to FIG. 2 a, a temperature-dependent, uniform, strain field, depicted by thick arrows, is shown incident on a single birefringent crystal 110 in a direction transverse to the direction of optical propagation. The strain field induces a change in the birefringence of the crystal 110 , and modifies the free spectral range (FSR) of the interferometer through equation 2. For any particular temperature dependence of the strain-free FSR, it is possible to solve for a required strain as a function of temperature that compensates this change, resulting in a temperature-stabilized BCI.
[0033] Referring to FIG. 2 b, the temperature-dependent, uniform, strain field, is shown incident on a separate compensating plate 120 fabricated from a normally isotropic material, such as a glass block, for providing a compensating, temperature dependent FSR. As the normally isotropic glass block 120 is subject to strain, it becomes birefringent. The retardance that results from this small additional birefringence exactly compensates the change in FSR of the crystal.
[0034] Although, this embodiment has the disadvantage of a second optical component, it provides several advantages in terms of flexibility.
[0035] First, since the only function of the glass block 120 is to compensate for thermal drift of the crystal, both the material and the size of the glass 120 is selected to provide best performance. This is in contrast to the embodiment shown in FIG. 2 a, wherein the material and length of the crystal 110 are constrained by the desired FSR through equation 1.
[0036] Secondly, for a given strain, additional length of the compensator plate 120 provides additional shift of the resonant frequency since the retardance induced scales linearly with the length of material through which the light propagates. A corollary is that, in principle, this embodiment provides compensation for any crystal over any temperature range simply by increasing the glass length until the maximum required strain falls within acceptable limits.
[0037] Finally, this embodiment advantageously allows the crystal 110 to be strain free, thus reducing the chances of fracturing or otherwise damaging the crystal. Furthermore, since the crystal 110 is strain free, the choice of crystal and/or temperature range is based on efficiency, not on resistance to breakage or damage.
[0038] As is well known in the art, strain-induced birefringence is proportional to strain to a high degree of accuracy. The temperature-induced change in the FSR is also nearly linear with temperature. Therefore, it is required that the strain change linearly with temperature in order to cancel out the temperature shift of the FSR. According to one embodiment of the instant invention, this is accomplished by constraining the crystal 110 in FIG. 2 a or the glass block 120 in FIG. 2 b, in a metal mount with a thermal expansion different than that of the crystal 110 or glass block 120 . Advantageously, this embodiment provides a substantially compact and self-stabilized BCI.
[0039] Referring to FIG. 3, there is shown a mount 130 supporting an optical element 140 , which is either the crystal 110 or glass plate 120 . The mount 130 , which is preferably a single metal or a combination of metals, as for example shown in FIG. 3 a, is arranged to be in close contact with the optical element at all operating and storage temperatures of the device. As the temperature changes, the differing rates of thermal expansion of the optical element 140 and the metal mount 130 generate a strain in the optical element 140 that changes linearly with temperature, as required (i.e., the metal mount functions as straining means). Optionally, a bi- or multi-metallic mount is designed such that the strain applied to the optic as a function of temperature is a function of the weighted average of the CTEs and dimensions of the metals, as well as the Young's moduli of all materials. Although the mount 130 is depicted as having three sides for surrounding the rectangularly shaped optical element 140 , 2 or 4 sides are also possible. Advantageously, the three-sided design provides a one-piece construction that allows the optical element 140 to be easily placed therein. Preferably, the mount provides at least two opposing sides for providing compressive strain in the crystal.
[0040] Preferably, the strain field throughout the element 140 is uniform in order to generate uniform birefringence and to reduce excess stress that could damage the optical element 140 . To provide this uniform loading, a thin compliant layer between the mount and the crystal is optionally provided. This pad deforms in response to local non-uniform stress and therefore improves the uniformity of contact between the optical element 140 and the mount 130 . Moreover, the thermal conductivity of the mount 130 is preferably large to minimize any possible thermal gradients within the mount that create non-uniform loading of the crystal by the mount, or non-uniformities in temperature-dependence of the retardance of the optical material.
[0041] It is further preferred that strain fields in directions other than that intended be minimized. For example, when the strain is induced in a direction perpendicular to the optical signal as illustrated in FIG. 2, shear strain in the crystal due to the thermal expansion of the crystal and mount is preferably controlled.
[0042] In order to reduce large stresses that typically form near the corners of the optical element 140 in the mount 130 , the corners of the optical element are optionally rounded or chamfered.
[0043] Depending on the sign of the effective elastooptic coefficient of the optical element 140 under strain and the sign of the FSR shift of the optical element 140 with temperature, the strain in the optical element 140 increases or decreases linearly with temperature.
[0044] Referring to FIGS. 4 a and 4 b, the dependence of strain (S) on temperature (T) is shown. The sign of the slope in FIG. 4 may be calculated by comparing the magnitude of the thermal expansion of the optical element 140 to that of the mount 130 . For example, if the mount has a larger thermal expansion than the optical element then the strain will decrease with increasing temperature (FIG. 4 a ), whereas if the thermal expansion of the mount is smaller than the thermal expansion of the optical element then the strain will increase linearly with temperature (FIG. 4 b ).
[0045] As shown in FIG. 4, the pre-load at room temperature (marked by a star) is set so that, over the storage temperature range of the device, the strain never exceeds the damage threshold of the material or decreases lower than zero, the latter of which causes the mount 130 and the optical element 140 to separate. This pre-load has the second important property of adjusting the resonant frequency of the BCI, in analogy to the quartz plate 30 described in the prior art. To achieve the largest change in resonant frequency for a given strain, in the absence of a temperature change, it is advantageous to arrange the mutual orientation of the optical element 140 and the mount 130 to harness the largest effective elastooptic coefficient. This coefficient is calculated for the different possible orientations by someone of ordinary skill in the art. To generate the largest strain from a particular optical element 140 and mount 130 material, it is advantageous to orient the optical element 140 to have the largest compliance aligned to the direction of the induced strain. Of course, these considerations are not important for normally isotropic materials such as the glass block 120 .
[0046] Referring to FIG. 5, an alternate method of adjusting the strain-induced birefringence is shown. In this embodiment, the effective interaction length of the optical element 140 is adjusted by sliding it with respect to the mount 130 . Since the strain-induced change in the retardance δ(Δn·L i ) is proportional to the interaction length L i , another means, in combination with appropriate design for mount-applied strain, for adjusting both the initial total retardance (to adjust for the fabrication tolerance of the crystal length) and the slope of the retardance change with temperature (to adjust for material property variations), is provided. Preferably, the mounting scheme is designed to avoid any non-uniformity in applied strain field at the peripheral parts of the portion of the optic that are in direct contact with the mount. For example, in addition to actively moving the optical element 140 relative to the entire mount as shown in FIG. 5 a in order to change the interaction length, the mount could be constructed from two or more metals as shown in FIG. 5 b. Motion of the optic relative to the mount in the direction of light propagation then varies the relative areas of contact with the various metals and hence varies the applied strain. Notably, the bimetallic mount shown in FIG. 5 b is not limited to the embodiment shown in FIG. 5, but is a useful alternative to the mount described above for any embodiment where a weighted average of the strain provided by two or more different metals is required.
[0047] Advantageously, the strain-stabilized BCI in accordance with the instant invention has fewer optical parts, thus reducing materials cost, assembly time, and optical insertion loss, while increasing reliability. Greatly reduced complexity of construction is provided by eliminating the need to measure a pool of each of two crystal types and pick appropriate crystals plus a quartz plate to achieve the desired FSR and resonant frequency.
[0048] Furthermore, the instant invention provides a method of setting the resonant frequency (the facility to continuously adjust and then fix the applied ‘pre-load’ strain at the nominal operating temperature) that is both more accurate and precise in comparison to the discrete tuning provided by a finite set of quartz plates. Also, the instant apparatus and method removes any error in the FSR caused by mounting, since the adjustment is made on the mounted crystal.
[0049] Moreover, the instant invention provides a more accurate control of the temperature-dependence of the BCI. Since the temperature compensation in the invention is controlled by the relative thermal expansions of the optical element and its mount, the limitation on stability is set by the repeatability of these expansions. Since the composition of crystal, glass, and metal materials is substantially repeatable, the thermal stability of the system is accurately controlled. In contrast, the thermal stability of the two-crystal BCI is set by length fabrication tolerances that are at the edge of the state-of-the-art.
[0050] Although the instant invention has been described using compressive strain, it is obvious to one skilled in the art, that tensile (stretching) or shear strain could produce an identical effect. For example, tensile strain may be more appropriate for very thin compensating plates (e.g. a thin plastic sheet).
[0051] Similarly, the instant invention disclosed herein includes a method of modifying the temperature dependence of a BCI by inducing strain in a crystal or an isotropic material that then becomes weakly birefringent under the strain. Clearly, these concepts are combinable with any other temperature stabilization or resonant-frequency tuning technique.
[0052] Preferably, the strain is induced by applying a stress in a direction traversing the propagation of light, however, other directions are possible. The term “stress” as used herein refers to a force exerted when one body, or a part of one, presses upon, pulls upon, pushes against, or tends to stress, compress, or twist another body or part of one. Although, it is most convenient to apply a stress in one axis, perpendicular to the direction of optical propagation, it is also possible to apply a stress in both perpendicular directions or, with appropriate mounting, parallel to the direction of optical propagation. Accordingly, the straining means includes any apparatus capable of asserting a stress on one of the crystal 110 and the glass block 120 . For example, active straining means such as a device using piezo-electric transducers to apply stress to the optical element 140 is possible.
[0053] The simple linear expansion of all physical effects described here results in a requirement for a linear variation of strain with temperature. However, more complex (non-linear) functions are achieved by appropriate choice of materials. Advantageously, the non-linearity may be used to create some desired variation of the BCI FSR with temperature. Alternatively, nonlinear variations of the physical parameters (e.g. elastooptic coefficient, thermal expansion, or compliance) are balanced against one another to achieve a greater degree of temperature compensation.
[0054] Advantageously, in the embodiments described herein, the straining means are passive and the optical system including the temperature-stabilized crystal is absent any external feedback circuits. Further advantageously, the passive straining means provides a substantially constant net retardance of the light transmissive element(s) (e.g., the birefringent crystal or the combination of the birefringent crystal and the glass block) over a given temperature range and in the spectral region of desired device operation.
[0055] Of course, numerous other embodiments can be envisaged without departing from the spirit and scope of the invention | The invention provides an optical system for use in a stable, temperature-insensitive birefringent crystal interferometer (BCI). The optical system includes a first block of light transmissive birefringent material having an input port and an output port, the material having in the spectral region of desired device operation a net retardance at a first temperature, and straining means for inducing a strain in one of the first block and a second block of light transmissive material optically coupled to the first block, the strain induced for maintaining the net retardance substantially unchanged from the net retardance at at least a second other temperature. Advantageously, the optical system uses a single variety of crystal, which is cheaper, more robust, and has better performance than BCIs having two crystal varieties. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of co-pending U.S. Provisional Application No. 61/039,776, filed on Mar. 26, 2008, the content of which is incorporated herein by reference for all purposes.
FIELD OF THE DISCLOSURE
The present disclosure generally relates to methods and apparatus for exploring subsurface formations. More particularly, the present disclosure relates to methods and apparatus for sensing acoustic activity in subsurface formations.
BACKGROUND OF THE DISCLOSURE
Various types of acoustic sensing are used during hydrocarbon production. Generally speaking, acoustic sensing may be active or passive. Active acoustic sensing applications include vertical seismic profiling and hydrofracture monitoring, or any other application that includes source activation. In hydrofracture monitoring, for example, a fluid may be injected into the formation to stimulate microseismic activity. Passive applications do not use ancillary means to stimulate the well but instead simply monitor acoustic activity created during production, or monitoring. In each sensing application, the acoustic sensors are used to obtain information to help operators better understand the characteristics of the fracture, such as propagation direction, geometry, dip, and other parameters. In active monitoring applications, the information permits adjustment, in real time, of the injection process parameters in case of a mismatch between the planned and actual fracture. The “real-time” expression refers here to enabling a reaction in a time which is fast enough to have an impact on the economics of the fracturing job (for instance stopping the injection in case the fracture is in danger of extending into a water zone).
Many current microseismic fracture monitoring systems employ a wireline seismic array tool deployed in a monitoring well. A monitoring well, however, is not always available or suitable for microseismic monitoring (e.g., if located too far from the injection well). In addition, there is a high cost associated with running a seismic wireline tool in a monitoring well, mainly coming from the preparation of the monitoring well.
Other fracture monitoring systems have been proposed in which the sensors are deployed in the injection well, thereby eliminating the need for a monitoring well. These systems, however, are typically limited to use in applications where tubing is used to convey the fracture fluid.
SUMMARY OF THE DISCLOSURE
According to one embodiment disclosed herein, a method of monitoring acoustic activity in a formation having a wellbore is provided in which a flow manipulation device is positioned into the wellbore, the flow manipulation device defog a chamber and a flow path through which fluid may flow. A sensor unit is positioned in the flow manipulation device chamber such that the sensor unit is separated from the flow path by the flow manipulation device. Finally, acoustic activity is detected in the formation with the sensor unit.
In another embodiment, an apparatus is provided for obtaining acoustic data from a formation having a wellbore formed therein. The apparatus includes a housing sized for insertion into the wellbore, the housing including an exterior wall, an interior wall defining a flow path through which fluid may flow, and a chamber disposed between the exterior and interior walls. A sensor unit is disposed in the housing chamber and responsive to acoustic energy emanating from the formation.
In a further embodiment, a method of monitoring microseismic events in a formation from a wellbore is provided that includes positioning a flow manipulation device into the wellbore, the flow manipulation device defining a flow path through which fluid may flow. Fluid is then pumped into the wellbore and through the manipulation device. A sensor disposed near the manipulation device is then coupled to the formation, the formation is fractured with fluid, and acoustic activity in the formation is detected with the sensor.
Other advantages and features will be apparent from the following detailed description when read in conjunction with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the disclosed methods and apparatuses, reference should be made to the embodiments illustrated in greater detail in the accompanying drawings, wherein:
FIG. 1 is a schematic side elevation view, in partial cross-section, of a downhole monitoring tool positioned in a wellbore;
FIG. 2 is a perspective, cross-sectional view of the monitoring tool of FIG. 1 ;
FIG. 3 is a plan, cross-sectional view of an acoustic monitoring tool disposed in a wellbore and having a coupling system;
FIG. 4 is side elevation view in cross-section of an acoustic monitoring tool having a packer in a retracted position; and
FIG. 5 is a side elevation view in cross-section of the acoustic monitoring tool of FIG. 4 , with the packer in the expanded position.
It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are illustrated graphically, diagrammatically and in partial views. In certain instances, details which are not necessary for an understanding of the disclosed methods and apparatuses or which render other details difficult to perceive may have been omitted. It should be understood, of course, that this disclosure is not limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTION
So that the above recited features and advantages of the present disclosure can be understood in detail, a more particular description of the disclosure may be had by reference to the embodiments thereof that are illustrated in the accompanied drawings. It is to be noted, however, that the drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.
An acoustic monitoring system is disclosed which can be deployed in the treatment well, thereby eliminating the need for a monitoring well. The tool may be operated as either a memory tool or as a wireline tool, and is configured to facilitate easy removal from the wellbore.
When the tool is a memory tool, acoustic data may be recorded to a memory device (hard disk or flash), and the tool may powered by a battery. The tool may be deployed using a wireline in which case the tool is coupled to the formation as shown in FIGS. 1 and 2 and as described in more detail below. Alternatively, the tool may be deployed during casing deployment for open hole non-cemented wells, in which case the tool is connected to a casing joint, possibly via a mandrel. In this case, the tool is either connected to the surface recording equipment using a control line deployed behind casing or, in the case of a memory tool, accessed by wireline. In another exemplary embodiment, the tool may be conveyed by coiled tubing and may be attached at a distal end thereof. Regardless of the manner of conveyance, as the tool is retrieved after/during the job, data is analyzed after the fracture of the formation.
When the tool is a wireline tool, the tool may be deployed just before injection of fracturing fluid. The wireline is used to provide power to the downhole electronics and motors, and to convey the digital data uphole. The communication link can either be copper or optical telemetry. Acoustic coupling of the sensors to the formation may be ensured by a motor actuated retractable system as shown in FIG. 3 , although alternate methods or apparatus may be used.
Furthermore, while one aspect of the disclosure is monitoring microseismicity induced by hydraulic fracturing or reservoir activity, this disclosure also contemplates the field of VSP (Vertical Seismic profiling), where an active source (airgun, dynamite or vibroseis) is used to generate an acoustic signal.
FIG. 1 illustrates a hydraulic fracture monitoring system 10 employed in a wellbore 12 . The wellbore 12 traverses a formation 14 having a reservoir or area 16 designated for hydraulic fracture. The wellbore 12 may be lined, such as with mudcake or a casing 122 .
A hydraulic fracture system 18 is provided for injecting fracture fluid into the reservoir 16 . The hydraulic fracture system 18 may include a source of fracture fluid, a pump operably coupled to the fracture fluid source, and a fracture fluid controller 20 for controlling operation of the pump. The system 18 is operable to inject fluid into the wellbore 12 , thereby increasing fluid pressure in the reservoir 16 to stimulate microseismic activity. An exemplary point 22 exhibiting microseismic activity is shown in FIG. 1 propagating seismic waves 24 , which may include compression wave (“P-wave”) and shear wave (“S-wave”) components.
A downhole monitoring tool 120 is disposed in the wellbore 12 for detecting microseismic activity in the formation. In the embodiment illustrated in FIG. 1 , the tool 120 is configured as a wireline tool. Accordingly, the tool 120 is attached to a cable 26 deployed from a rig 28 . While FIG. 1 shows the rig 28 , a wireline arrangement that does not have a rig may be used.
As best shown in FIG. 2 , the illustrated tool 120 includes a flow manipulation device in the form of a housing 124 . The housing 124 is configured to redirect fluid flow as it travels along the borehole in the vicinity of the tool 120 . Accordingly, the housing 124 defines a flow path along which the hydraulic fracture fluid may flow.
In the exemplary embodiment, the flow path is surrounded by the housing 124 . As best shown in FIG. 2 , the housing 124 has a generally annular shape formed by an exterior wall 126 and an interior wall 128 . The exterior and interior walls 126 , 128 may be formed of a material having a sufficient hardness to minimize erosion during use, and may be constructed of the same wall. The material may further have acoustic properties which attenuate noise. Exemplary materials suitable for use include steel, stainless steel, titanium alloy, and inconel, however other materials having sufficient hardness and/or noise attenuation may also be used. The walls 126 , 128 may be formed entirely of a single material or may have a base layer and an external coating or layer. The exterior wall 126 is cylindrical and may define a substantially uniform diameter. The interior wall 128 , however, may include a first transition section 128 a , an intermediate section 128 b , and a second transition section 128 c . The first transition section 128 a may have an irregular, frustoconical shape with an outer end 130 having a larger diameter and an inner end 132 having a smaller diameter. The intermediate section 128 b may have a cylindrical shape with a substantially uniform diameter approximately equal to the smaller diameter of the first transition section inner end 132 . The second transition section 128 c may have a frustoconical shape similar to, but inverted from, the first transition section 128 a . Accordingly, the second transition section 128 c may have an inner end 134 sized at the smaller diameter and an outer end 136 having the larger diameter. The flow path defined by the housing 124 , therefore, has a varying cross-sectional area that gradually decreases through the first transition section 128 a , is substantially uniform through the intermediate section 128 b , and gradually increases through the second transition section 128 c.
The flow path may further be configured to minimize the amount of noise generated by fluid flowing therethrough. Accordingly, the housing interior wall 128 may be shaped to promote laminar fluid flow along the path.
The housing 124 further provides an enclosure for protecting a sensor unit 142 from the injection fluid. As best shown in FIG. 2 , the housing 124 defines a chamber 140 sized to receive the sensor unit 142 . The chamber 140 is formed in the annular space between the exterior wall 126 and the interior wall 128 , or may simply be within or on the tool 120 . The chamber 140 is widest at a central portion located between the intermediate section 128 b of the interior wall and the exterior wall 126 . As shown in the illustrated embodiment, a centerline 144 of the intermediate section 128 b may be offset from a centerline 146 of the casing 122 to maximize the width of the chamber central portion.
The sensor unit 142 is disposed in the housing chamber 140 and is configured to detect microseismic activity in the formation. The sensor unit 142 may include one or more sensors 143 ( FIG. 1 ) for detecting seismic, acoustic, or related energy. Exemplary sensors include hydrophones, geophones (including optical), MEMS, pressure/temperature sensors, or other types of sensors, or combinations thereof.
A data processing system 110 is operatively coupled to the sensor unit 142 by the cable 26 ( FIG. 1 ). The data processing system 110 is configured to receive, store, and/or process signals from the sensors 143 . Accordingly, the data processing system 110 may include control, communication, and processing circuitry, a power supply, a processor, a RAM, a recorder, and the like. In certain embodiments, the data processing system 110 may omit one or more of the foregoing components. For example, if an optical geophone is used, it may be coupled to the data processing system 110 using optical fiber, in which case electrical power is not needed to transmit the signals. The processor may be a suitably programmed general purpose computer system, a special purpose digital or analog computer, or other device.
Based on the acoustic signals generated by the sensors 143 , the data processing system 110 may run programs containing instructions that, when executed, perform various routines for processing the signals. These routines may be fully automated and capable of continuous operation in time for monitoring, detecting, and locating microseismic events. An operator may receive results from the process routines in real time, such as on a display monitor, and may adjust hydraulic fracture parameters such as pumping pressure, stimulation fluid, and proppant concentrations to optimize wellbore stimulation based on the displayed information.
In operation, an acoustic monitoring tool 120 may be inserted into a wellbore using one of the many known methods. A source may then be activated to generate acoustic and/or seismic energy that is received by the tool sensor unit 142 . In the illustrated embodiment, the energy source is microseismic activity in the formation induced by hydraulic fluid pressure in the reservoir. Alternatively, the energy source may be located at the surface, in the wellbore, or at an adjacent monitoring wellbore. During fracture fluid injection, the tool 120 directs the fluid flow away from the sensor unit 142 , thereby enabling the sensor unit 142 to be disposed in the same wellbore as the injection fluid. The annular shape of the housing 124 shown in FIG. 2 prevents, or at least minimizes, flow restriction during the injection process to facilitate fracture fluid injection. The energy sensed by the sensor unit 142 is converted into a signal representing data, such as seismic data. The data is communicated to the data processing system 110 , in which one or more stored programs will process the data to derive useful information regarding the location, geometry, or other characteristics of the microfractures in the formation.
While the foregoing describes a single acoustic monitoring tool 120 in the wellbore 12 , multiple tools may be used. Furthermore, additional downhole tools other than microseismic monitoring tools may be deployed in the wellbore 12 .
An optional coupling system may be provided for reducing unwanted noise during acoustic sensing. The coupling system may be used to place the sensor unit nearer to or in direct contact with the casing, thereby to improve seismic/acoustic sensing. Additionally, the coupling system may better secure the tool in place, thereby to damp unwanted vibrations or other sources of undesirable noise. Without a coupling system, the tool may tend to move or vibrate during fluid flow, thereby generating noise. Various types of coupling systems may be used, either individually or in combination, to minimize or eliminate unwanted noise.
FIG. 3 illustrates an acoustic monitoring tool 150 including a piston-type coupling system 152 . The tool 150 is disposed in a casing 154 , and includes a housing 156 in which a sensing unit 158 is disposed. The coupling system 152 includes arms 160 coupled to the housing 156 and a contact pad 162 coupled to the arms 160 . The arms 160 are radially extendable between a retracted position, in which the contact pad 162 is positioned closer to the housing 156 , and an extended position, in which the contact pad 162 is farther from the housing 156 to engage the casing 154 (as shown in FIG. 3 ). Acoustic coupling between the sensor unit 158 and the microseismic energy source is provided when the contact pad 162 engages the formation or casing wall, as the sensor is in direct contact with, as opposed to off-set from, the formation/casing wall.
Additionally or alternatively, the sensor unit and/or housing may be suspended or may include a dampening mechanism to absorb and/or remove unwanted noise. In particular, the sensor unit may be connected to the tool using a mechanical filter, such that the sensor unit is isolated from the housing. The tool also may be connected to the formation/casing using a similar spring dashpot system. Alternatively, the sensor unit may be coupled to the tool by a magnetic system.
FIGS. 4 and 5 illustrate a further embodiment of an acoustic monitoring tool 200 . The tool 200 may include a housing 202 similar to that of the embodiment shown in FIGS. 1-3 , but it also includes a packer 210 which may be used to seal between the wellbore and the tool 200 to force fluid through the tool 200 . The housing 202 may include an inner wall 203 defining a flow path 205 . The housing 202 is disposed in a wellbore 204 formed in a formation.
The packer 210 may be similar to conventional packers that are well-known in the art, except as discussed below. Accordingly, the packer 210 may have an annular shape extending around a periphery of the housing 202 . In the illustrated embodiment, the packer 210 defines an annular chamber 211 . The packer 210 may also have a contact surface 212 . The packer 210 may be formed of a resilient material that permits movement between a retracted position and an extended position. In the retracted position as best shown in FIG. 4 , the contact surface 212 is spaced from the surface of the wellbore 204 . In the extended position as best shown in FIG. 5 , the contact surface 212 engages the surface of the wellbore 204 . The packer 210 may be moved between retracted and expanded positions using any known type of packer actuator, such as controlling pressurized fluid flow into the packer interior chamber 211 . A controller may be provided for controlling actuation of the packer 210 .
The tool 200 further includes a sensor unit 214 for detecting acoustic and/or seismic energy. The illustrated sensor unit 214 is disposed in the packer interior chamber 211 and includes a chassis 216 holding one or more sensors 218 . Accordingly, the packer 210 provides a protective enclosure for the sensor unit 214 . As noted above, the one or more sensors 218 may include sensors for detecting seismic, acoustic, or related energy. Exemplary sensors include hydrophones, geophones (including optical), MWMS, pressure/temperature sensors, or other types of sensors, or a combination thereof.
The tool 200 may further include means for communicating sensed data to a remote location, such as to the surface. In the illustrated embodiment, a telemetry line 220 is operatively coupled to the sensor unit 214 , however other communication means may be used. Additionally or alternatively, the tool 200 may include storage media for storing the sensor data.
In operation, the packer 210 may be actuated to acoustically couple the sensor unit 214 to the formation. When the packer 210 is placed in the expanded position, such as by increasing fluid pressure in the chamber 211 , the contact surface 212 will engage the wellbore wall, as shown in FIG. 5 , thereby placing the sensor unit 214 in close proximity to the formation. Multiple tools 200 may be spaced along the housing 202 to form a seismic array.
While the foregoing describes monitoring at a specific depth in the wellbore, it will be appreciated that the various tool embodiments disclosed herein may be quickly and easily repositioned to different wellbore depths to obtain acoustic information related to multiple target zones in the formation.
Moreover, inventive aspects lie in less than all features of a single disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment. The embodiments and aspects were chosen and described in order to best explain the principles of the invention and its practical application. The preceding description is intended to enable others skilled in the art to best utilize the principles in various embodiments and aspects and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims. | A method of monitoring acoustic activity in a formation from a wellbore includes positioning a flow manipulation device into the wellbore, the flow manipulation device defining a flow path through which fluid may flow. Fluid is then pumped into the wellbore and through the manipulation device. A sensor disposed near the manipulation device is then coupled to the formation, the formation is fractured with fluid, and acoustic events in the formation are detected with the sensor. | 6 |
FIELD OF THE INVENTION
The present invention refers to adjustment of the needle guard plate on a vertical axis hook or crochet of a lockstitch sewing machine.
BACKGROUND OF THE INVENTION
In lockstitch sewing machines the crochet or hook has a peripheral “hook point” extending for a distance along the circumference of the hook. The hook, by rotating around its own axis, grips with said point the loop formed by the upper thread or needle thread, a loop which forms at the start of the movement of withdrawal or raising of the needle. The point of the hook must brush the needle to grip the loop of thread. Any bending of the needle, due for example to the force exerted thereon by a sideways translation of the fabric, could bring it to be situated on the trajectory of the hook point and could cause a collision with probable breakage of the needle or splintering of the hook point. In order to avoid this, a needle guard plate is provided which serves to prevent the needle from bending in the direction of the hook tip. The plate has an arched shape, in its working portion seen in a plan view, and rotates integrally with the hook body.
FIG. 28 is a top perspective view illustrating a vertical axis hook 1 , according to the prior art, provided with a hook point 2 , and a needle-protecting plate, or needle-guard plate, denoted by reference numeral 3 .
Adjustment of the position of the plate in a radial direction with respect to the axis of the hook is generally required or desirable to adapt the hook to the type and size of needle used. The state of the art comprises various solutions for mounting plates on the hook body, so as to be able to perform said adjustment. Needle guard plates are generally considered to be grouped into three families according to the type of construction: a first family comprises so-called “flange plates”, formed by a sheet of metal bent into an L-shape which is placed with the flat part between the hook and its axial resting point on the sewing machine; a second family comprises “flange-mounted plates” wherein a flange is fastened to the rear part of the hook; a third family comprises the “peripheral plates”, obtained from sheet metal bent in an arch and fastened to the side of the hook body.
The subject matter of the present invention concerns the field of peripheral plates.
Peripheral plates are positioned on and fastened to the body of the hook. Some currently known and used methods of fastening will be described briefly.
According to a first method, the plate is mounted on the side of the hook by means of two head countersunk screws which centre the respective seats on the plate and therefore perform both the positioning function and that of fastening of the plate. The two screws are in proximity to the opposite end of the plate with respect to the hook point and leave the part of the plate near the hook point projecting. A variant of said system consists in fastening with four screws, two for each end of the plate.
In a second manner, the plate is positioned in a circumferential groove on the side of the hook and is fastened by means of two flat-headed screws, which therefore serve no positioning function, but only that of fastening.
As far as adjustment of peripheral plates is concerned, the following three systems are known and used.
a) The mounted plate is adjusted only by manual deformation of the bending curve of the projecting part with respect to the positioning and fastening system. Adjustment can therefore be only rough.
b) A third screw is placed on the side of the body of the hook at the opposite end of the needle guard plate with respect to the positioning and fastening portion. The screw, when it is loosened, presses on the tip of the plate and obliges outward deformation thereof. The screw normally requires a braking system (typically a locking thread) and holds the disadvantage of not being able to be applied to all hooks, in that it requires an adequate space, on the side of the hook and near the hook tip, a space which often is not available. Such an adjustment system is described in patents DE G 8116870 and IT 1151267.
c) In the case of the hook with a plate positioned in the groove, whilst positioning of the plate is performed by the groove and fastening of the plate by the flat-headed screw nearest the end of the plate, for fine adjustment use is made of the second screw, positioned between the fastening screw and the tip of the plate at the hook point. In this case the plate has a double bend which, without the second screw, would position it far to the outside of the hook tip. By screwing the second screw, on the other hand, the plate is forced inwards.
SUMMARY OF THE INVENTION
An object of the present invention is to reduce production costs of hook with an adjustable plate.
A further object is to be able to apply a finely adjustable plate on a hook where this was not hitherto possible because of problems of space.
The object has been achieved with a hook as stated in claim 1 . Further new and useful characteristics are disclosed in the dependent claims.
In other words, in the hook of the invention fine adjustment of the peripheral needle guard plate is achieved without the need for a third screw in proximity to the point of the hook and with the sole function of adjustment, and without the need for a slot for positioning of the plate.
In one embodiment, three screws (two countersunk head for fastening and positioning and one for adjustment), all positioned on the portion of plate opposite that facing towards the hook point. The plate has a double bend and the third screw forces the plate inward.
In another embodiment, two countersunk head screws are used, one of which serves for positioning and fastening, whereas the second serves for positioning and adjustment. The plate has a double bend and the second screw forces the plate inwards.
In a third embodiment, two screws are used, one countersunk head for fastening and the second flat-headed for positioning and adjustment, having a cylindrical shape between the head and the thread which couples with a horizontal slot on the plate.
In a fourth embodiment two screws are used, the first being countersunk head and having a positioning and fastening function, whereas the second, serving for positioning and adjustment, works in thrust and is shaped with a cylindrical pin protruding from the head of the screw. Said pin enters a hole or slot in the plate and it is also possible from the pin to act to tighten or loosen said screw. The plate is naturally bent inwards and is forced outwards by loosening the screw.
In a fifth embodiment two screws are used, the first of which is countersunk head and serves for positioning and adjustment, whereas the second serves for positioning and adjustment. The second screw serves for “dual effect” adjustment: that is, it works both in traction and in thrust, depending on whether it is more or less tightened. The plate is bent to be level with the hook point with the adjustment screw half tightened. The adjustment screw has two flanges that remain one on the inside and one on the outside of the needle guard plate. The outer flange is flat in shape.
A sixth embodiment is similar to the fifth but the outer flange of the adjustment screw is conical.
The invention achieves the aforementioned objects, in particular it achieves lower production costs for the hook and allows simplified adjustment where it was not otherwise possible.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention, will be described hereunder by way of non-limiting illustration with reference to the appended figures, wherein:
FIG. 1 is a partially sectional plan view of a vertical axis hook according to a first embodiment of the invention; the plate is drawn with a slid line in an extreme position of adjustment near the axis a 10 of the hook, with a dashed line in the other extreme position of adjustment farther from the axis a 10 ;
FIG. 2 is a side view from the right of FIG. 1;
FIG. 3 is a view of the hook plate of FIGS. 1 and 2, on an enlarged scale and in the extended position;
FIG. 4 is a side view on an enlarged scale of a fastening and adjustment screw for the plate of the first embodiment;
FIG. 5 is a partially sectional plan view of a hook according to a second embodiment of the invention, with the adjustable plate in the extreme position nearest the axis a 20 and the adjustment screw completely tightened; the plate in the adjusted position furthest from the axis a 20 of the hook is shown with a dashed line,
FIG. 6 is a view from the right with respect to FIG. 5,
FIG. 7 is a view of the plate of the hook of FIGS. 5 and 6, on an enlarged scale and in the extended condition,
FIG. 8 is a partially sectional plan view of a third embodiment of the hook according to the invention, with plate indicated with a solid line in one extreme position and with a dashed line in the other extreme position,
FIG. 9 is a side view from the right of FIG. 8,
FIG. 10 is a view of the plate of the hook of FIGS. 8 and 9, on an enlarged scale and in the extended condition,
FIG. 11 is an enlarged side view of an adjustment screw for the plate of the hook of FIGS. 8 and 9,
FIG. 12 is a plan view of a hook according to a fourth embodiment, with the plate drawn with a solid line in one extreme position and with a dashed line in the other extreme position,
FIG. 13 is a side view from the right of the hook of the preceding figure,
FIG. 14 is an enlarged side view of the plate of the hook of FIGS. 12 and 13 in the extended condition,
FIG. 15 is an enlarged side view of an adjustment screw for the hook of FIGS. 13 and 14,
FIG. 16 is a partially sectional plan view of a hook according to a fifth embodiment, with the plate drawn with a solid line in one extreme position and with a dashed line in the other extreme position,
FIG. 17 is a side view from the right of the hook of FIG. 16,
FIG. 18 is an enlarged side view of the plate of the hook of FIGS. 16 and 17, in the extended condition,
FIG. 19 is an enlarged side view of the plate of the hook of FIGS. 16 and 17, in the extended condition,
FIG. 20 is an enlarged side view of another variant of the plate of the hook of FIGS. 16 and 17, in the extended condition,
FIG. 21 is an enlarged side view of an adjustment screw for the plate of the hook in FIG. 18,
FIG. 22 is a partially sectional plan view of a hook according to a sixth embodiment, with the plate drawn with a solid line in one extreme position and with a dashed line in the other extreme position,
FIG. 23 is a side view from the right of the hook of FIG. 22,
FIG. 24 is an enlarged side view of the plate of the hook of FIGS. 22 and 23, in the extended position,
FIG. 25 is an enlarged side view of a variant of the plate of the hook of FIGS. 22 and 23, in an extended position,
FIG. 26 is an enlarged side view of another variant of the plate of the hook of FIGS. 22 and 23, in an extended condition,
FIG. 27 is an enlarged side view of an adjustment screw for the plate of the hook of FIGS. 22-26;
FIG. 28 is a perspective view of a hook according to the state of the art.
A hook according to the prior art has been described above with reference to FIG. 28 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference first to FIGS. 1 to 4 , a hook according to the invention is designated as a whole with reference numeral 10 , is rotatable around its own axis denoted by a 10 and comprises a hook body 11 , with a hook point, 11 a , and a needle-guard plate of the hook, 12 .
The plate 12 can be seen better in FIG. 3, wherein it is illustrated enlarged and extended. The plate comprises a working portion 12 a facing towards the tip of the hook and designed to cooperate therewith, and a fastening and positioning portion 12 b . The working portion, in the view of FIG. 3, has a tapered and rounded shape at the distal end, having a narrow neck 12 c and an adjustment hole or slot 13 at the proximal end. The fastening portion of the plate is substantially rectangular in shape and has two aligned fastening and positioning holes, denoted by 14 , 15 . All three holes 13 , 14 , 15 have an outwardly countersunk aperture. The plate 12 is applied to the hook. The fastening portion 12 b thereof is curved in an arc of a circle, in a manner corresponding to the curvature of the hook body. The working portion 12 a has a double curvature, that is to say, it is curved outwardly (with respect to the axis of the hook crochet) in the area corresponding to the line b 12 drawn dashed, between the holes 13 and 14 , and it is curved in an arch around the axis of the hook in its distal portion.
The plate 12 is applied to the hook by means of three screws indicated by 16 , 17 and 18 (FIG. 1 ). The screw 16 is an adjustment screw and occupies the hole 13 of the plate, the screws 17 and 18 are fastening and positioning screws, and occupy the holes 14 and 15 of the plate. The three screws screw into the threaded holes 13 ′, 14 ′ and 15 ′ in the hook body. In this embodiment, the three screws 16 , 17 and 18 are identical. In FIG. 4 the screw 16 , which is of a per se known type, comprising a threaded shank 16 a and a countersunk head 16 b , is illustrated. The head of the screw 16 could also be cylindrical and consequently not require countersinking of the hole 13 .
The plate 12 is mounted on the body of the hook around the periphery thereof, and fastened and positioned level with its fastening portion with the screws 17 and 18 , in a per se known manner. Owing to the deformation that has been imparted to it, the plate is disposed with its working portion slightly distanced from the periphery of the hook body (position indicated by dashed line). The screw 16 engages the working portion of the blade and the body. By tightening the screw 16 the blade is forced toward the hook crochet body (axis), by loosening the screw the very elasticity of the plate moves it away from the hook body; it is thus possible to adjust the position of the plate with respect to the point 11 (to the axis a 10 ) of the hook.
A second embodiment of the hook (rotatable around the axis a 20 ) with adjustable plate is indicated by reference numeral 20 and illustrated in appended FIGS. 5, 6 and 7 ; it comprises a hook body 21 with a hook point 21 a , and a hook plate 22 .
The plate 22 can be seen better in FIG. 7, wherein it is illustrated enlarged, and extended. The plate comprises a working portion 22 a facing towards the hook point and designed to cooperate therewith and a fastening and positioning portion 22 b . The working portion, in the view of FIG. 7, is tapered and rounded in shape at the distal end, has a narrow neck 22 c and an adjustment hole 23 at the proximal end. The fastening portion 22 b of the plate is substantially rectangular in shape and has a fastening and positioning hole, indicated by 24 . The holes 23 , 24 have an outwardly countersunk opening. The plate 22 is applied to the hook. The fastening portion 22 b thereof is curved in an arc of a circle, in a manner corresponding to the curvature of the hook body. The working portion 22 a has a double curvature, that is to say it is curved outward (with respect to the hook axis) in the area corresponding to the dashed line b 22 , between the holes 23 and 24 , and it is curved in an arch around the axis of the hook in its distal portion.
The plate 22 is applied to the hook by means of two screws indicated by 26 and 27 . The screw 26 is a positioning and adjustment screw, the screw 27 is a fastening and positioning screw. In this embodiment, the two screws 26 , 27 are identical and identical to the screw 16 illustrated in FIG. 4 .
The plate 22 is mounted on the hook body around the periphery thereof, and fastened and positioned at its fastening portion with the screw 27 , in a per se known manner. Owing to the deformation that has been imparted to it, the plate is disposed with its working portion slightly distanced from the periphery of the hook body. The screw 26 engages the working portion of the plate and the body. By tightening and loosening the screw 26 it is possible to adjust the position of the plate 22 with respect to the point 21 a of the hook 21 . The screw 26 serves for adjustment and positioning of the plate, that is to say it adjusts the position of the plate towards or away from the hook point (from the axis of the hook) and positions the plate in the direction of the axis a 20 .
A third embodiment of the hook with an adjustable plate is indicated by reference numeral 30 and illustrated in appended FIGS. 8, 9 , 10 and 11 ; it comprises a hook body 31 with a hook point 31 a and a hook plate 32 .
The plate 32 can be seen better in FIG. 10, wherein it is illustrated enlarged and extended. The plate comprises a working portion 32 a facing towards the hook point, and designed to cooperate therewith, and a fastening and positioning portion 32 b . The working portion, in the view of FIG. 10, is tapered and rounded in shape at the distal end, has a narrow neck 32 c and an adjustment slot 33 at the proximal end. The shape of the slot 33 is elongated longitudinally with respect to the plate. The fastening portion of the plate is substantially rectangular in shape and has a fastening and positioning hole, indicated by 34 , with an outwardly countersunk opening. The plate 32 is applied to the hook. The fastening portion 32 b thereof is curved in an arc of a circle, in a manner corresponding to the curvature of the hook body. The working portion 32 a has a double curvature, that is to say it is curved outward (with respect to the hook axis) in the area corresponding to the line b 32 drawn with a dashed line, between the holes 33 and 34 , and is curved in an arch around the axis of the hook in the distal portion thereof. The plate 32 is applied to the hook by means of two screws denoted by 36 and 37 . The screw 36 is an adjusting and positioning screw, the screw 37 is a fastening and positioning screw. The screw 37 is identical to the screw 16 illustrated in FIG. 4 . The screw 36 is illustrated in FIG. 11 and has a threaded shank 36 a , a cylindrical neck 36 b , and a widened cylindrical head 36 c . The diameter of the neck is smaller that the transverse measurement of the slot 33 , the diameter of the head is greater that the transverse measurement of the slot. The plate 32 is mounted on the hook body around the periphery thereof, and fixed and positioned at its fastening portion with the screw 37 , in a per se known manner. Owing to the deformation that has been imparted thereto, the plate is disposed with its working portion slightly distanced from the periphery of the hook body. The screw 36 engages the working portion of the plate with its portion 36 b and the shoulder 36 ' c of the head 36 c and the hook body with its threaded part 36 a.
By tightening and loosening the screw 36 it is possible to adjust the position of the plate with respect to the hook point 31 .
A fourth embodiment of the hook with an adjustable plate is indicated by reference numeral 40 and illustrated in appended FIGS. 12, 13 , 14 and 15 ; it comprises a hook body 41 with a hook point 41 a , and a hook plate 42 .
The plate 42 can be seen better in FIG. 14, wherein it is illustrated enlarged and extended. In this view, it is identical to the plate 32 of the previous embodiment. It therefore comprises a working portion 42 a facing towards the hook point and designed to cooperate therewith, and a fastening and positioning portion 42 b . The working portion, in the view in FIG. 14, is tapered and rounded in shape at the distal end, has a narrow neck 42 c and an adjustment slot 43 at the proximal end. The shape of the slot 43 is elongated longitudinally with respect to the plate. The fastening portion of the plate is substantially rectangular in shape and has a fastening and positioning hole, denoted by 44 , with an outwardly countersunk opening. The plate 42 is applied to the hook and is curved in an arc of a circle, in a manner corresponding to the curvature of the hook body. The working portion 42 a is preliminarily curved inward, towards the axis of the hook, with respect to the hook point 41 a.
The plate 42 is applied to the hook crochet by means of two screws denoted by 46 , 47 . The screw 46 is a plate adjusting and positioning screw, the screw 47 is a fastening and positioning screw identical to the screw 16 illustrated in FIG. 4 . The screw 46 (FIG. 15) has a threaded shank 46 a , a countersunk flange 46 b , and a cylindrical head 46 c . The maximum diameter of the countersunk flange is greater than the transverse measurement of the slot 43 ; the diameter of the head 46 c is smaller than the transverse measurement of the slot.
The plate 42 is mounted on the hook body around the periphery thereof, and fastened and positioned at its fastening portion with the screw 47 , in a per se known manner, after having engaged the adjustment screw 46 in a suitable countersunk hole in the hook body. The screw 46 engages the slot 43 of the plate with its cylindrical head and the surface of the plate facing toward the hook body with the abutment surface 46 ' b of the countersunk flange. By loosening the screw 46 it is possible to adjust the position of the plate bringing it away from the hook axis, by tightening the screw 46 , the plate is returned towards the hook axis by its own elasticity.
A fifth embodiment of the hook with an adjustable plate is indicated by reference numeral 50 and illustrated in appended FIGS. 16-21; it comprises a hook body 51 with a hook point 51 a and a hook crochet plate 52 . The plate 52 can be seen better in FIG. 18, wherein it is illustrated enlarged and extended. It comprises a working portion 52 a facing towards the hook point, and designed to cooperate therewith, and a fastening and positioning portion 52 b.
The working portion, in the view of FIG. 18, is tapered and rounded in shape at the distal end, has a narrow neck 52 c and an adjustment slot 53 open on one side. The fastening portion of the plate is substantially rectangular in shape and has a fastening and positioning hole, designated by 54 , with an outwardly countersunk opening. The plate 52 is applied to the hook crochet with the fastening portion 52 b thereof, curved in an arc of a circle, in a manner corresponding to the curvature of the hook body. The working portion 52 a is also curved according to the periphery of the hook body.
The plate 52 is applied to the hook by means of two screws denoted by 56 , 57 . The screw 56 is a plate adjusting and positioning screw; the screw 57 is a fastening and positioning screw identical to the screw 16 illustrated in FIG. 4 . The screw 56 has a threaded shank 56 a , a countersunk flange 56 b , a cylindrical flange 56 c , and a neck 56 d therebetween. The maximum diameter of the flanges is greater than the width of the slot 53 ; the diameter of the neck 56 d is smaller than the transverse measurement of the slot.
The plate 52 is mounted on the hook body around the periphery thereof after the screw 56 has been inserted with the neck 56 d in the slot 53 , and is fastened and positioned at its fastening portion with the screw 57 , in a per se known manner. The screw 56 engages the slot of the plate with the neck 56 d, and engages the surface of the plate facing towards the body of the hook with the abutment surface of its countersunk flange 56 b , or the outer surface of the plate with the abutment surface of the cylindrical outer flange 56 c , depending on whether the screw is acted upon to bring plate away from or toward the hook axis.
FIGS. 19 and 20 present variants of the plate that it is possible to use with the hook 50 and the screw 56 . The plate 52 ′ has, instead of the slot 53 , a slot 53 ′ made up of two portions with different diameters, with their axes aligned transversally to the longitudinal dimension of the plate. The portion with the largest diameter allows the passage of the flanges of the adjustment screw; the portion with the smallest diameter has a smaller diameter than the flanges and a larger diameter than the neck 56 d of the adjustment screw. The plate 52 ″ is similar to 52 ′ except that the slot with two diameters 53 ″ has the axis of the two portions aligned longitudinally with respect to the plate.
A sixth embodiment of the hook with an adjustable plate is indicated by reference numeral 60 and illustrated in appended FIGS. 22-27; it comprises a hook body 61 with a hook point 61 a and a hook plate 62 .
The plate 62 and its variants 62 ′, 62 ″ can be seen better in FIGS. 24, 25 and 26 , wherein they are illustrated enlarged and extended. The plates correspond substantially to the plates 52 , 52 ′ and 52 ″, except that the adjustment slot 63 , 63 ′, 63 ″, or the part of the adjustment slot with the smallest diameter, has countersunk walls. No detailed description of the plates 62 , 62 ′, 62 ″ will therefore be given.
The plate 62 is applied to the hook by means of two screws designated 66 , 67 . The screw 66 is an adjusting and positioning screw; the screw 67 is a fastening and positioning screw identical to the screw 16 illustrated in FIG. 4 . The screw 66 has a threaded shank 66 a , a proximal countersunk flange 66 b , a distal countersunk flange 66 c , and a neck 66 d therebetween. The maximum diameter of the flanges is greater than the width of the slot or of the part of the plate slots with the smallest diameter; the diameter of the neck 66 d is smaller than the transverse measurement of the slot or of the part of the slot with the smallest diameter.
The screw 66 engages the slot of the plate with the neck 66 d , and engages the surface of the plate towards the hook body with its proximal flange 66 b , or the outer surface of the plate with respect to the hook with its distal flange 66 c , depending on whether the screw is acted upon to move the plate away from or toward the hook axis.
Further variants are possible and it is understood that all variants accessible to a person skilled in the art of normal experience in any case come within the scope of the invention as set forth in the appended claims. | A vertical axis hook ( 10 ) for a lockstitch sewing machine comprises a hook body ( 11 ) with a hook point and a peripheral needle guard plate ( 12 ) mounted on the hook body, the plate comprising a fastening and positioning portion and an adjustable portion integral with each other. It further comprises a plate adjustment means to adjust the radial position of the adjustable portion with respect to the hook point. The plate adjustment and positioning means ( 16 ) acts in a position of the adjustable portion of the plate which is near the fastening portion thereof. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 13/649,294 filed Oct. 11, 2012, currently pending, which claims the benefit of:
[0002] U.S. Application No. 61/581,907 filed Dec. 30, 2011;
[0003] U.S. Application No. 61/581,922 filed Dec. 30, 2011;
[0004] U.S. Application No. 61/581,878 filed Dec. 30, 2011; and
[0005] U.S. Application No. 61/581,890 filed Dec. 30, 2011;
[0000] the entire disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0006] The present invention generally relates to compositions comprising C5 and C6 saccharides of varying degrees of polymerization and/or containing maximum levels of undesirable impurities, such as compounds containing sulfur, nitrogen, or metals, especially those processed from lignocellulosic biomass using supercritical, subcritical, and/or near critical fluid extraction.
BACKGROUND OF THE INVENTION
[0007] There are a number of processes for converting lignocellulosic biomass into liquid streams of various fermentable sugars. Certain preferred processes are based on supercritical water (SCW) or hot compressed water (HCW) technology, which offer several advantages including high throughputs, use of mixed feedstocks, separation of sugars, and avoidance of concentrated acids, microbial cultures, and enzymes. Processes using hot compressed water may have two distinct operations: pre-treatment and cellulose hydrolysis. The pre-treatment process hydrolyzes the hemicellulose component of the lignocellulosic biomass and cellulose hydrolysis (CH) process, as its name infers, hydrolyzes the cellulose fibers. The resultant five carbon (C5) and six carbon (C6) sugar streams are recovered separately. The remaining solids, which consist mostly of lignin, are preferably recovered, such as through filtration, and may be used as a fuel to provide thermal energy to the process itself or for other processes.
[0008] Among their many uses, the sugar streams may be converted to ethanol through fermentation using yeast or bacteria that feed on the sugars. As the sugars are consumed, ethanol and carbon dioxide are produced.
[0009] The invention is directed to these compositions, as well as and other important ends.
SUMMARY OF THE INVENTION
[0010] In one embodiment, the invention is directed to compositions, comprising:
[0011] at least one water-soluble C6 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0012] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0013] less than about 5250 ppm in total by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of elements;
[0014] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0015] In another embodiment, the invention is directed to compositions, comprising:
[0016] at least one water-soluble C6 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0017] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0018] less than about 10 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of aluminum;
[0019] less than about 3000 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of calcium;
[0020] less than about 350 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of iron; and
[0021] less than about 1000 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of sulfur.
[0022] In other embodiments, the invention is directed to compositions, comprising:
[0023] at least one water-soluble C6 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0024] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0025] less than about 10 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of aluminum.
[0026] In a further embodiment, the invention is directed to compositions, comprising:
[0027] at least one water-soluble C6 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0028] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0029] less than about 3000 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of calcium.
[0030] In yet other embodiments, the invention is directed to compositions, comprising:
[0031] at least one water-soluble C6 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0032] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0033] less than about 350 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of iron.
[0034] In another embodiment, the invention is directed to compositions, comprising:
[0035] at least one water-soluble C6 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0036] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0037] less than about 1000 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of sulfur.
[0038] In yet another embodiment, the invention is directed to compositions, comprising:
[0039] about 10% by weight to about 25% by weight, based on total weight of C6 saccharides present in said composition, of C6 disaccharides;
[0040] about 10% by weight to about 25% by weight, based on total weight of C6 saccharides present in said composition, of C6 trisaccharides;
[0041] about 10% by weight to about 25% by weight, based on total weight of C6 saccharides present in said composition, of C6 tetrasaccharides;
[0042] about 10% by weight to about 25% by weight, based on total weight of C6 saccharides present in said composition, of C6 pentasaccharides; and
[0043] about 10% by weight to about 50% by weight, based on total weight of C6 saccharides present in said composition, of C6 saccharides having at a degree of polymerization of at least about 6.
[0044] In further embodiments, the invention is directed to compositions, comprising:
[0045] about 80% by weight to about 95% by weight, based on total weight of C6 saccharides present in said composition, of water-soluble C6 oligosaccharides;
[0046] wherein said water-soluble C6 oligosaccharides have a degree of polymerization of about 2 to about 15.
[0047] In other embodiments, the invention is directed to compositions, comprising:
[0048] at least one water-soluble C5 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0049] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0050] less than about 3700 ppm in total by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of elements;
[0051] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0052] In one embodiment, the invention is directed to compositions, comprising:
[0053] at least one water-soluble C5 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0054] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0055] less than about 10 ppm by weight, based on the total weight of C5 saccharide hydrolysate in said composition, of aluminum;
[0056] less than about 2300 ppm by weight, based on the total weight of C5 saccharide hydrolysate in said composition, of calcium;
[0057] less than about 50 ppm by weight, based on the total weight of C5 saccharide hydrolysate in said composition, of iron; and
[0058] less than about 150 ppm by weight, based on the total weight of C5 saccharide hydrolysate in said composition, of sulfur.
[0059] In further embodiments, the invention is directed to compositions, comprising:
[0060] at least one water-soluble C5 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0061] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0062] less than about 10 ppm, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of aluminum.
[0063] In yet further embodiments, the invention is directed to compositions, comprising:
[0064] at least one water-soluble C5 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0065] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0066] less than about 2300 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of calcium.
[0067] In another embodiment, the invention is directed to compositions, comprising:
[0068] at least one water-soluble C5 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0069] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0070] less than about 50 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of iron.
[0071] In yet another embodiment, the invention is directed to compositions, comprising:
[0072] at least one water-soluble C5 oligosaccharide hydrolysate, especially those hydrolysates processed from lignocellulosic biomass using supercritical or near critical fluid extraction;
[0073] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0074] less than about 150 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of sulfur.
[0075] In certain embodiments, the invention is directed to methods of reducing the level of enzyme required for enzymatically hydrolyzing first water-soluble C6 saccharides having an average degree of polymerization to about 2 to about 15, preferably about 2 to about 10, and more preferably about 2 to about 6, to second water-soluble C6 saccharides having a lower average degree of polymerization than said average degree of polymerization of said first water-soluble C6 saccharides, comprising:
[0076] providing a hydrolysate comprising said first water-soluble C6 saccharides and less than about 5250 ppm in total, based on total weight of water-soluble C6 saccharide hydrolysate in said composition, of elements;
[0077] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0078] In certain embodiments, the invention is directed to methods of reducing the level of enzyme required for enzymatically hydrolyzing first water-soluble C5 saccharides having an average degree of polymerization to about 2 to about 28, preferably about 2 to about 15, more preferably about 2 to about 13, even more preferably about 2 to about 6, to second water-soluble C5 saccharides having a lower average degree of polymerization than said average degree of polymerization of said first water-soluble C5 saccharides, comprising:
[0079] providing a hydrolysate comprising said first water-soluble C5 saccharides and less than about 3700 ppm in total, based on total weight of water-soluble C5 saccharide hydrolysate in said composition, of elements;
[0080] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
BRIEF DESCRIPTION OF THE DRAWINGS
[0081] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
[0082] FIG. 1A is a scan from a DIONEX high pressure liquid chromatography device with an electrochemical detector of a C6 oligosaccharide composition of one embodiment of the invention.
[0083] FIG. 1B is a scan from a DIONEX high pressure liquid chromatography device with an electrochemical detector of a C6 oligosaccharide composition of one embodiment of the invention.
[0084] FIG. 2A is a scan from a DIONEX high pressure liquid chromatography device with an electrochemical detector of a C5 oligosaccharide composition of one embodiment of the invention.
[0085] FIG. 2B is a scan from a DIONEX high pressure liquid chromatography device with an electrochemical detector of a C5 oligosaccharide composition of one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0086] As employed above and throughout the disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings.
[0087] As used herein, the singular forms “a,” “an,” and “the” include the plural reference unless the context clearly indicates otherwise.
[0088] While the present invention is capable of being embodied in various forms, the description below of several embodiments is made with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiments illustrated. Headings are provided for convenience only and are not to be construed to limit the invention in any manner. Embodiments illustrated under any heading may be combined with embodiments illustrated under any other heading.
[0089] The use of numerical values in the various quantitative values specified in this application, unless expressly indicated otherwise, are stated as approximations as though the minimum and maximum values within the stated ranges were both preceded by the word “about.” In this manner, slight variations from a stated value can be used to achieve substantially the same results as the stated value. Also, the disclosure of ranges is intended as a continuous range including every value between the minimum and maximum values recited as well as any ranges that can be formed by such values. Also disclosed herein are any and all ratios (and ranges of any such ratios) that can be formed by dividing a recited numeric value into any other recited numeric value. Accordingly, the skilled person will appreciate that many such ratios, ranges, and ranges of ratios can be unambiguously derived from the numerical values presented herein and in all instances such ratios, ranges, and ranges of ratios represent various embodiments of the present invention.
[0090] As used herein, the phrase “substantially free” means have no more than about 1%, preferably less than about 0.5%, more preferably, less than about 0.1%, by weight of a component, based on the total weight of any composition containing the component.
[0091] A supercritical fluid is a fluid at a temperature above its critical temperature and at a pressure above its critical pressure. A supercritical fluid exists at or above its “critical point,” the point of highest temperature and pressure at which the liquid and vapor (gas) phases can exist in equilibrium with one another. Above critical pressure and critical temperature, the distinction between liquid and gas phases disappears. A supercritical fluid possesses approximately the penetration properties of a gas simultaneously with the solvent properties of a liquid. Accordingly, supercritical fluid extraction has the benefit of high penetrability and good solvation.
[0092] Reported critical temperatures and pressures include: for pure water, a critical temperature of about 374.2° C., and a critical pressure of about 221 bar; for carbon dioxide, a critical temperature of about 31° C. and a critical pressure of about 72.9 atmospheres (about 1072 psig). Near critical water has a temperature at or above about 300° C. and below the critical temperature of water (374.2° C.), and a pressure high enough to ensure that all fluid is in the liquid phase. Sub-critical water has a temperature of less than about 300° C. and a pressure high enough to ensure that all fluid is in the liquid phase. Sub-critical water temperature may be greater than about 250° C. and less than about 300° C., and in many instances sub-critical water has a temperature between about 250° C. and about 280° C. The term “hot compressed water” is used interchangeably herein for water that is at or above its critical state, or defined herein as near-critical or sub-critical, or any other temperature above about 50° C. (preferably, at least about 100° C.) but less than subcritical and at pressures such that water is in a liquid state.
[0093] As used herein, a fluid which is “supercritical” (e.g. supercritical water, supercritical CO 2 , etc.) indicates a fluid which would be supercritical if present in pure form under a given set of temperature and pressure conditions. For example, “supercritical water” indicates water present at a temperature of at least about 374.2° C. and a pressure of at least about 221 bar, whether the water is pure water, or present as a mixture (e.g. water and ethanol, water and CO 2 , etc). Thus, for example, “a mixture of sub-critical water and supercritical carbon dioxide” indicates a mixture of water and carbon dioxide at a temperature and pressure above that of the critical point for carbon dioxide but below the critical point for water, regardless of whether the supercritical phase contains water and regardless of whether the water phase contains any carbon dioxide. For example, a mixture of sub-critical water and supercritical CO 2 may have a temperature of about 250° C. to about 280° C. and a pressure of at least about 225 bar.
[0094] As used herein, “lignocellulosic biomass or a component part thereof” refers to plant biomass containing cellulose, hemicellulose, and lignin from a variety of sources, including, without limitation (1) agricultural residues (including corn stover and sugarcane bagasse), (2) dedicated energy crops, (3) wood residues (including hardwoods, softwoods, sawmill and paper mill discards), and (4) municipal waste, and their constituent parts including without limitation, lignocellulose biomass itself, lignin, saccharides (including cellulose, cellobiose, C 6 oligosaccharides, C 6 monosaccharides, C 5 saccharides (including hemicellulose, C 5 oligosaccharides, and C 5 monosaccharides), and mixtures thereof.
[0095] As used herein, “ash” refers to the non-aqueous residue that remains after a sample is burned, and consists mostly of metal oxides. Ash content may be measured in accordance with ASTM Standard Method No. E1755-01 “Standard Method for the Determination of Ash in Biomass.” This test method covers the determination of ash, expressed as the percentage of residue remaining after dry oxidation at 550 to 600° C. All results are reported relative to the 105° C. oven dry weight of the sample.” See also: Sluiter, A. et al., “Determination of Ash in Biomass,” National Renewable Energy Laboratory (NREL) Technical Report NREL/TP-510-42622, Jul. 17, 2005; and ASTM Standard Method No. E1755-01 “Standard Method for the Determination of Ash in Biomass,” 2007, which are both incorporated herein by reference in their entirety.
[0096] As used herein, “degree of polymerization” refers to the number of monomeric units in a macromolecule or polymer or oligomer molecule, including those monomeric units that are not identical (such as in a oligomer with different monomeric residues). The degree of polymerization (DP) of the various saccharides in the compositions of the invention may be measured using gel permeation chromatography (GPC), high pressure liquid chromatography (HPLC), such as DIONEX with an electrochemical detector, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, or other conventional molecular weight determination methods.
C6 Saccharides
[0097] Accordingly, in one embodiment, the invention is directed to compositions, comprising C6 saccharides. In particular embodiments, the compositions comprise:
[0098] at least one water-soluble C6 oligosaccharide hydrolysate;
[0099] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0100] less than about 5250 ppm in total by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of elements;
[0101] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0000] In certain embodiments, the elements are present at a level of less than about 5100 ppm in total by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition.
[0102] In another embodiment, the invention is directed to compositions, comprising:
[0103] at least one water-soluble C6 oligosaccharide hydrolysate;
[0104] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0105] less than about 10 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of aluminum;
[0106] less than about 3000 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of calcium;
[0107] less than about 350 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of iron; and
[0108] less than about 1000 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of sulfur.
[0000] In certain preferred embodiments, such compositions further comprise:
[0109] less than about 5250 ppm in total by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of elements;
[0110] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0111] In other embodiments, the invention is directed to compositions, comprising:
[0112] at least one water-soluble C6 oligosaccharide hydrolysate;
[0113] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0114] less than about 10 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of aluminum.
[0000] In certain preferred embodiments, such compositions further comprise:
[0115] less than about 5250 ppm in total by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of elements;
[0116] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0117] In a further embodiment, the invention is directed to compositions, comprising:
[0118] at least one water-soluble C6 oligosaccharide hydrolysate;
[0119] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0120] less than about 3000 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of calcium.
[0000] In certain preferred embodiments, such compositions further comprise:
[0121] less than about 5250 ppm in total by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of elements;
[0122] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0123] In yet other embodiments, the invention is directed to compositions, comprising:
[0124] at least one water-soluble C6 oligosaccharide hydrolysate;
[0125] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0126] less than about 350 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of iron.
[0000] In certain preferred embodiments, such compositions further comprise:
[0127] less than about 5250 ppm in total by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of elements;
[0128] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0129] In another embodiment, the invention is directed to compositions, comprising:
[0130] at least one water-soluble C6 oligosaccharide hydrolysate;
[0131] optionally, at least one water-soluble C6 monosaccharide hydrolysate; and
[0132] less than about 1000 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of sulfur.
[0000] In certain preferred embodiments, such compositions further comprise:
[0133] less than about 5250 ppm in total by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of elements;
[0134] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0135] In certain embodiments, the water-soluble C6 oligosaccharide hydrolysate has a degree of polymerization of about 2 to about 15. In other embodiments, water-soluble C6 oligosaccharide hydrolysate has a degree of polymerization of about 2 to about 13. In other embodiments, water-soluble C6 oligosaccharide hydrolysate has a degree of polymerization of about 2 to about 10. In other embodiments, water-soluble C6 oligosaccharide hydrolysate has a degree of polymerization of about 2 to about 6.
[0136] In certain embodiments, the compositions further comprise at least one water-soluble C6 monosaccharide hydrolysate.
[0137] In certain embodiments, the water-soluble C6 monosaccharide hydrolysate is glucose, galactose, mannose, fructose, or a mixture thereof.
[0138] In certain embodiments, the compositions further comprise less than about 10 ppm, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of aluminum, preferably less than about 5 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of aluminum.
[0139] In certain embodiments, the compositions further comprise less than about 3000 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of calcium, preferably less than about 2950 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of calcium.
[0140] In certain embodiments, the compositions further comprise less than about 350 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of iron, preferably less than about 325 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of iron.
[0141] In certain embodiments, the compositions further comprise less than about 1000 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of sulfur, preferably less than about 975 ppm by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of sulfur.
[0142] In certain embodiments, wherein the ratio of the total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate to said elements is greater than about 45:1, preferably greater than about 47:1.
[0143] In certain embodiments, the level of said elements are measured by inductively coupled plasma emission spectroscopy.
[0144] In other embodiments, the compositions less than about 1500 mg of nitrogen per kg of total weight of water-soluble C6 saccharides, preferably less than about 1450 of nitrogen per kg of total weight of water-soluble C6 saccharides. Nitrogen may be measured by thermal conductivity detection after combustion and reduction.
[0145] In yet other embodiments of the compositions, the weight ratio of the collective mass of hydrogen and nitrogen to mass of carbon present in said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate is less than about 0.14. Carbon, hydrogen, and nitrogen levels may be measured by thermal conductivity detection after combustion and reduction.
[0146] In certain other embodiments, the compositions comprising the C6 saccharides further comprise less than a maximum of any of the elements, individually or in combination, in the table listed below:
[0000]
Level less than about
(ppm or mg of element/kg
Element
of C6 saccharides)
As
0.5
B
0.7
Ba
2.6
Be
0.05
Cd
0.10
Co
0.05
Cr
0.17
Cu
1.2
K
130
Li
0.05
Mg
180
Mn
15.0
Mo
0.7
Na
375
Ni
0.9
P
12.0
Pb
0.3
Sb
0.3
Se
0.6
Si
85.0
Sn
0.25
Sr
5.0
Ti
0.05
Tl
0.7
V
0.05
Zn
65
[0147] In another embodiment, the compositions comprise:
[0148] about 80% by weight to about 95% by weight, based on total weight of C6 saccharides present in said composition, of water-soluble C6 oligosaccharides;
[0149] wherein said water-soluble C6 oligosaccharides have a degree of polymerization of about 2 to about 15.
[0000] In certain embodiments, said water-soluble C6 oligosaccharides are present at a level of about 80% by weight to about 92.5% by weight, based on total weight of C6 saccharides present in said composition. In certain embodiments of the composition, said water-soluble C6 oligosaccharides have a degree of polymerization of about 2 to about 13, preferably, about 2 to about 10, and more preferably about 2 to about 6. In certain embodiments, the compositions further comprise about 5% by weight to about 20% by weight, based on total weight of C6 saccharides present in said composition, of C6 monosaccharides.
[0150] In certain embodiments of the compositions described herein, said water-soluble C6 oligosaccharide hydrolysate comprises:
[0151] about 10% by weight to about 25% by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of C6 disaccharides;
[0152] about 10% by weight to about 25% by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of C6 trisaccharides;
[0153] about 10% by weight to about 25% by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of C6 tetrasaccharides;
[0154] about 10% by weight to about 25% by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of C6 pentasaccharides; and
[0155] about 10% by weight to about 50% by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of C6 saccharides having at a degree of polymerization of at least about 6.
[0000] In certain embodiments, the compositions further comprise:
[0156] about 5% by weight to about 20% by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of C6 monosaccharides.
[0000] In certain embodiments, the compositions further comprise:
[0157] about 7.5% by weight to about 20% by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of C6 monosaccharides.
[0158] In other embodiments, the compositions comprise:
[0159] about 10% by weight to about 25% by weight, based on total weight of C6 saccharides present in said composition, of C6 disaccharides;
[0160] about 10% by weight to about 25% by weight, based on total weight of C6 saccharides present in said composition, of C6 trisaccharides;
[0161] about 10% by weight to about 25% by weight, based on total weight of C6 saccharides present in said composition, of C6 tetrasaccharides;
[0162] about 10% by weight to about 25% by weight, based on total weight of C6 saccharides present in said composition, of C6 pentasaccharides; and about 10% by weight to about 50% by weight, based on total weight of C6 saccharides present in said composition, of C6 saccharides having at a degree of polymerization of at least about 6.
[0163] In other embodiments of the compositions, said C6 disaccharides are present at a level of about 10% by weight to about 20% by weight, based on total weight of C6 saccharides present in said composition.
[0164] In other embodiments of the compositions, said C6 trisaccharides are present at a level of about 10% by weight to about 20% by weight, based on total weight of C6 saccharides present in said composition.
[0165] In other embodiments of the compositions, said C6 tetrasaccharides are present at a level of about 10% by weight to about 20% by weight, based on total weight of C6 saccharides present in said composition.
[0166] In other embodiments of the compositions, said C6 pentasaccharides are present at a level of about 10% by weight to about 20% by weight, based on total weight of C6 saccharides present in said composition.
[0167] In other embodiments of the compositions, said C6 saccharides having at a degree of polymerization of at least about 6 are present at a level of about 10% by weight to about 20% by weight, based on total weight of C6 saccharides present in said composition.
[0168] In other embodiments, the compositions further comprise:
[0169] about 5% by weight to about 20% by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of C6 monosaccharides.
[0000] In certain embodiments, the compositions further comprise about 7.5% by weight to about 20% by weight, based on total weight of said water-soluble C6 oligosaccharide hydrolysate and said water-soluble C6 monosaccharide hydrolysate in said composition, of C6 monosaccharides.
[0170] In other embodiments, the compositions further comprise water.
[0171] In certain embodiments, the water-soluble C6 oligosaccharide hydrolysate and the water-soluble C6 monosaccharide hydrolysate are processed from lignocellulosic biomass using supercritical, subcritical, or near critical fluid extraction, or a combination thereof.
C5 Saccharides
[0172] Accordingly, in one embodiment, the invention is directed to compositions, comprising C5 oligosaccharides. In particular, the compositions comprise:
[0173] at least one water-soluble C5 oligosaccharide hydrolysate;
[0174] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0175] less than about 3700 ppm in total by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of elements;
[0176] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0177] In one embodiment, the invention is directed to compositions, comprising:
[0178] at least one water-soluble C5 oligosaccharide hydrolysate;
[0179] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0180] less than about 10 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of aluminum;
[0181] less than about 2300 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of calcium;
[0182] less than about 50 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of iron; and
[0183] less than about 150 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of sulfur.
[0000] In certain embodiments, the elements are present at a level of less than about 3610 ppm in total by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition.
[0184] In further embodiments, the invention is directed to compositions, comprising:
[0185] at least one water-soluble C5 oligosaccharide hydrolysate;
[0186] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0187] less than about 10 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of aluminum.
[0188] In yet further embodiments, the invention is directed to compositions, comprising:
[0189] at least one water-soluble C5 oligosaccharide hydrolysate;
[0190] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0191] less than about 2300 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of calcium.
[0192] In another embodiment, the invention is directed to compositions, comprising:
[0193] at least one water-soluble C5 oligosaccharide hydrolysate;
[0194] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0195] less than about 50 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of iron.
[0196] In yet another embodiment, the invention is directed to compositions, comprising:
[0197] at least one water-soluble C5 oligosaccharide hydrolysate;
[0198] optionally, at least one water-soluble C5 monosaccharide hydrolysate; and
[0199] less than about 150 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of sulfur.
[0200] In certain embodiments, the compositions described herein further comprise:
[0201] less than about 3700 ppm by weight in total, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of elements;
[0202] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0203] In certain embodiments, the water-soluble C5 oligosaccharide hydrolysate has a degree of polymerization of at least about 2 to about 28. In other embodiments, water-soluble C5 oligosaccharide hydrolysate has a degree of polymerization of at least about 2 to about 15. In other embodiments, water-soluble C5 oligosaccharide hydrolysate has a degree of polymerization of at least about 2 to about 10. In other embodiments, water-soluble C5 oligosaccharide hydrolysate has a degree of polymerization of at least about 2 to about 6.
[0204] In certain embodiments, the compositions further comprise:
[0205] at least one water-soluble C5 monosaccharide hydrolysate.
[0206] In certain embodiments, the water-soluble C5 monosaccharide hydrolysate is xylose, arabinose, lyxose, ribose, or a mixture thereof.
[0207] In certain embodiments, the compositions further comprise less than about 10 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of aluminum, preferably less than about 5 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of aluminum.
[0208] In certain embodiments, the compositions further comprise less than about 2300 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of calcium, preferably less than about 2250 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of calcium.
[0209] In certain embodiments, the compositions further comprise less than about 50 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of iron, preferably less than about 30 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of iron.
[0210] In certain embodiments, the compositions further comprise less than about 150 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of sulfur, preferably less than about 140 ppm by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of sulfur.
[0211] In certain embodiments, the ratio of total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition to said elements is greater than about 75:1, preferably greater than about 80:1.
[0212] In certain embodiments, the water-soluble C5 oligosaccharide hydrolysate is processed from lignocellulosic biomass using supercritical, subcritical, or near critical fluid extraction, or a combination thereof.
[0213] In certain embodiments, the level of said elements are measured by inductively coupled plasma emission spectroscopy.
[0214] In other embodiments, the compositions comprise less than about 350 ppm of nitrogen per kg of total weight of water-soluble C5 saccharides, preferably less than about 325 ppm of nitrogen per kg of total weight of water-soluble C5 saccharides. Nitrogen may be measured by thermal conductivity detection after combustion and reduction.
[0215] In yet other embodiments of the compositions, the weight ratio of the collective mass of hydrogen and nitrogen to mass of carbon present in said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate is less than about 0.14. Carbon, hydrogen, and nitrogen levels may be measured by thermal conductivity detection after combustion and reduction.
[0216] In certain other embodiments, the compositions comprising the C5 saccharides further comprise less than a maximum of any of the elements, individually or in combination, in the table listed below:
[0000]
Level less than about
(ppm or mg of element/kg
Element
of C5 saccharides)
As
0.7
B
2.5
Ba
4.2
Be
0.02
Cd
0.2
Co
0.1
Cr
0.2
Cu
0.70
K
350
Li
0.05
Mg
550
Mn
130
Mo
0.5
Na
50
Ni
0.75
P
95
Pb
0.5
Sb
0.5
Se
0.75
Si
25
Sn
0.5
Sr
15
Ti
0.02
Tl
0.75
V
0.02
Zn
20
[0217] In another embodiment, the compositions comprise:
[0218] about 75% by weight to about 90% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of water-soluble C5 oligosaccharides;
[0219] wherein said water-soluble C5 oligosaccharides have a degree of polymerization of about 2 to about 28.
[0000] In certain embodiments, said water-soluble C5 oligosaccharides are present at a level of about 80% by weight to about 90% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition. In certain embodiments of the composition, said water-soluble C5 oligosaccharides have a degree of polymerization of about 2 to about 16, preferably, about 2 to about 10, and more preferably, about 2 to about 5. In certain embodiments, the compositions further comprise about 10% by weight, to about 25% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of C5 monosaccharides.
[0220] In certain embodiments of the compositions described herein, said water-soluble C5 oligosaccharide hydrolysate comprises:
[0221] about 15% by weight, to about 30% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of C5 disaccharides;
[0222] about 10% by weight, to about 20% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of C5 trisaccharides;
[0223] about 5% by weight, to about 20% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of C5 tetrasaccharides;
[0224] about 2% by weight, to about 20% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of C5 pentasaccharides; and
[0225] about 10% by weight, to about 35% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of C5 saccharides having at a degree of polymerization of at least about 6.
[0000] In certain embodiments of the composition, said water-soluble C5 oligosaccharides have a degree of polymerization of about 2 to about 16, preferably, about 2 to about 10, and more preferably, about 2 to about 5. In certain embodiments, the compositions further comprise about 10% by weight, to about 25% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of C5 monosaccharides. In certain embodiments, the compositions further comprise about 12.5% by weight, to about 20% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of C5 monosaccharides.
[0226] In certain embodiments of the compositions described herein, said C5 disaccharides are present at a level of about 17.5% by weight to about 25% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition.
[0227] In certain embodiments of the compositions described herein, said C5 trisaccharides are present at a level of about 12.5% by weight to about 17.5% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition.
[0228] In certain embodiments of the compositions described herein, said C5 tetrasaccharides are present at a level of about 10% by weight to about 20% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition.
[0229] In certain embodiments of the compositions described herein, said C5 pentasaccharides are present at a level of about 2.5% by weight to about 15% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition.
[0230] In certain embodiments of the compositions described herein, said C5 saccharides having at a degree of polymerization of at least about 6 are present at a level of about 12.5% by weight to about 30% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition.
[0231] In certain embodiments, the compositions described herein further comprise about 10% by weight, to about 25% by weight, based on total weight of said water-soluble C5 oligosaccharide hydrolysate and said water-soluble C5 monosaccharide hydrolysate in said composition, of C5 monosaccharides.
[0232] In certain embodiments, the compositions described herein further comprise water.
[0233] In certain embodiments, the water-soluble C6 oligosaccharide hydrolysate and the water-soluble C6 monosaccharide hydrolysate are processed from lignocellulosic biomass using supercritical, subcritical, or near critical fluid extraction, or a combination thereof.
Further Embodiments
[0234] In certain embodiments, the invention is directed to methods of reducing the level of enzyme required for enzymatically hydrolyzing first water-soluble C6 saccharides having an average degree of polymerization to about 2 to about 15, preferably about 2 to about 10, and more preferably about 2 to about 6, to second water-soluble C6 saccharides having a lower average degree of polymerization than said average degree of polymerization of said first water-soluble C6 saccharides, comprising:
[0235] providing a hydrolysate comprising said first water-soluble C6 saccharides and less than about 5250 ppm in total, based on total weight of water-soluble C6 saccharide hydrolysate in said composition, of elements;
[0236] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0000] In certain embodiments, the C6 saccharides are extracted from lignocellulosic biomass. In other embodiments, the C6 saccharides are processed from lignocellulosic biomass using supercritical, subcritical, or near critical fluid extraction, or a combination thereof.
[0237] In certain embodiments, the invention is directed to methods of reducing the level of enzyme required for enzymatically hydrolyzing first water-soluble C5 saccharides having an average degree of polymerization to about 2 to about 28, preferably about 2 to about 15, more preferably about 2 to about 13, even more preferably about 2 to about 6, to second water-soluble C5 saccharides having a lower average degree of polymerization than said average degree of polymerization of said first water-soluble C5 saccharides, comprising:
[0238] providing a hydrolysate comprising said first water-soluble C5 saccharides and less than about 3700 ppm in total, based on total weight of water-soluble C5 saccharide hydrolysate in said composition, of elements;
[0239] wherein said elements are Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn.
[0240] In further embodiments, the compositions further comprise less than about 0.5% by weight, based on the total weight of said C5 saccharides or C6 saccharides, of organic solvent, such as alcohols, including water miscible lower aliphatic C 1 -C 4 alcohols (e.g., methanol, ethanol, isopropanol, t-butanol). In preferred embodiments, the compositions contain less than about 0.1% by weight, based on the total weight of said of said C5 saccharides or C6 saccharides of organic solvent. In more preferred embodiments, the compositions contain substantially no organic solvent.
[0241] The compositions of the invention are preferably prepared from biomass by processes employing supercritical, subcritical, and/or near critical water, preferably without the addition of acid. The processes may include pretreatment step or steps using supercritical or near critical water to separate the C5 sugars (monomers and/or oligomers) from cellulose and lignin. In the pretreatment step, suitable temperatures are about 130° C. to about 250° C., suitable pressures are about 4 bars to about 100 bars, and suitable residence times are about 0.5 minutes to about 5 hours. The processes may also include a cellulose hydrolysis step or steps using supercritical or near critical water to separate the cellulose (which may processed to form C6 monomeric and/or oligomeric sugars) from the lignin. In the hydrolysis step(s), suitable temperatures are about 250° C. to about 450° C., suitable pressures are about 40 bars to about 260 bars, and suitable residence times are about 0.1 seconds to about 3 minutes. The compositions may be prepared in any suitable reactor, including, but not limited to, a tubular reactor, a digester (vertical, horizontal, or inclined), or the like. Suitable digesters include the digester system described in U.S. Pat. No. 8,057,639, which include a digester and a steam explosion unit, the entire disclosure of which is incorporated by reference.
[0242] The compositions of the invention comprising C5 saccharides or C6 saccharides may be utilized in a wide variety of applications, where C5 and C6 sugars are conventionally utilized, including, but not limited to, the production of various chemicals and fuels using fermentative, enzymatic, catalytic, and non-catalytic (e.g., thermal decomposition) processes. Such processes are useful for preparing feedstocks for the preparation of the following non-exhaustive list:
[0243] fuels (such as gasoline, jet fuel, butanol, and the like);
[0244] chemicals (such as acetic acid, acetic anhydride, acetone, acrylic acid, adipic acid, benzene, ethanol, ethylene, ethylene glycol, ethylene oxide, methanol, polypropylene, terephthalic acid, toluene, xylene, 1,3-propanediol, 1,4-butanediol, and the like);
[0245] pharmaceuticals and foods (such as acetoin, alanine, arabitol, ascorbic acid, aspartic acid, citric acid, coumaric acid, fumaric acid, glycerol, glycine, kojic acid, lactic acid, lysine, malonic acid, proline, propionic acid, serine, sorbitol, succinic acid, threonine, xylitol, sugar acids (glucaric acid, gluconic acid, xylonic acids), and the like);
[0246] specialty chemicals (such as acontic acid, glutamic acid, malic acid, oxalic acid, and the like);
[0247] textile applications (such as formic acid and the like); and
[0248] industrial intermediates (acetaldehyde, 3-hydroxypropionic acid, 2,5-furan dicarboxylic acid, furfural, glutaric acid, itaconic acid, levulinic acid, and the like).
[0249] The present invention is further defined in the following Examples, in which all parts and percentages are by weight, unless otherwise stated. It should be understood that these examples, while indicating preferred embodiments of the invention, are given by way of illustration only and are not to be construed as limiting in any manner. From the above discussion and these examples, one skilled in the art can ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
EXAMPLES
Example 1
Preparation of Oligosaccharide Compositions
[0250] The C5 oligosaccharide and C6 oligosaccharide compositions of the invention were prepared using supercritical, subcritical, and near critical water extraction in a two stage process. Particulate lignocellulosic biomass consisting of mixed hardwood chips of 140 mesh or less was mixed with water to form a slurry (about 20% by weight solids). The slurry was heated to a temperature of about 170-245° C. and then feed into a pretreatment reactor for about 1-120 minutes under sufficient pressure to keep the water in the liquid phase. The pretreated slurry was then cooled to a temperature less than about 100° C. under little (less than about 10 bar) or no pressure. The pretreated solids were then separated from the liquid stream using a filter press. Alternatively, the solids may be separated using a centrifugal filter pressor. The pretreated solids were then mixed with water to form a slurry and the slurry was heated to a temperature of about 150-250° C. The slurry was then subjected to supercritical water at about 374-600° C. in a hydrolysis reactor for about 0.05-10 seconds under a pressure of about 230-300 bar. After exiting the hydrolysis reactor, the hydrolyzed slurry was quenched with water and then flashed to about ambient temperature and pressure to remove water. The lignin solids were then separated from the liquid stream using a centrifugal decanter and air dried.
[0251] The C5 oligosaccharides and the C6 oligosaccharides streams were first concentrated to about 200 g/L, adjusted to about pH 3-4 and filtered using 0.45 micron filter.
Example 2
Analysis of Oligosaccharide Compositions Using Inductively Coupled Plasma
[0252] The dried compositions containing the C5 and C6 oligosaccharides of Example 1 were analyzed using inductively coupled plasma emission spectroscopy. The results are shown in the table below:
[0000]
Oligomer (C6)
Oligomer (C5)
Species
g/liter or ppm
g/liter or ppm
Al
4.63
4.05
As
0.39
0.54
B
0.61
2.31
Ba
2.49
3.94
Be
0.00
0.01
Ca
2945.00
2245.00
Cd
0.05
0.11
Co
0.04
0.08
Cr
0.14
0.12
Cu
0.97
0.70
Fe
309.00
22.94
K
127.35
329.00
Li
0.03
0.02
Mg
178.00
545.50
Mn
14.40
126.40
Mo
0.58
0.32
Na
368.50
44.80
Ni
0.78
0.69
P
10.99
90.20
Pb
0.21
0.32
S
946.00
132.45
Sb
0.21
0.30
Se
0.45
0.66
Si
80.65
22.10
Sn
0.18
0.39
Sr
3.51
13.66
Ti
0.00
0.00
Tl
0.45
0.67
V
0.02
0.01
Zn
61.35
17.48
Example 3
Analysis of Oligosaccharide Compositions Using Gel Permeation Chromatography
[0253] The C5 oligosaccharide and C6 oligosaccharide compositions of the invention were prepared using supercritical, subcritical, and near critical water extraction in a two stage process as described in Example 1. The samples were then diluted ten times. The degree of polymerization was qualitatively determined, i.e., not quantifying the amount of each oligomer, using gel permeation chromatography.
[0254] As can be seen in FIGS. 1A and 1B , a degree of polymerization (DP) were detected up to at least a DP of 13, with small peaks visible above DP of 13 for the C6 oligosaccharide compositions. As can be seen in FIGS. 2A and 2B , a degree of polymerization (DP) were detected up to at least a DP of 28, with small peaks visible above DP of 28 for the C5 oligosaccharide compositions.
Example 4
Analysis of C6 Saccharide Compositions Using Gel Permeation Chromatography
[0255] The C6 saccharide compositions of the invention were prepared using supercritical, subcritical, and near critical water extraction in a two stage process as described in Example 1. Representative samples bracketing the extremes/possibilities of feed material source (tubular reactor), reactor temperature (348.2-383.4° C.), reactor residence time (0.19-1.48 seconds), and feed aqueous slurry concentration (6.4-14.77%) were selected.
[0256] The representative samples were analyzed using gel permeation chromatography. The area under each peak (indicating an individual mer unit in the saccharide) was measured to calculate weight % of each mer unit, based on the total weight of C6 saccharides present in the sample. The results are shown in the following table:
[0000]
C6
C6
C6
C6
C6
C6
hexasac-
mono-
disac-
trisac-
tetrsac-
pentasac-
charides
saccharides
charides
charides
charides
charides
+
Sample
(weight %)
(weight %)
(weight %)
(weight %)
(weight %)
(weight %)
1-1033
15.3
19.8
15.4
15.2
12.1
22.2
2-1448
19.3
19.1
18.9
15.6
14.7
12.4
3-1252
8.9
11.3
13.3
12.4
16.6
37.5
4-2125
16.8
17.1
17.1
15.4
15.9
17.8
5-2344
13.689
16.444
15.454
14.945
12.652
26.816
6-1600
7.914
10.087
11.397
13.024
12.71
44.867
Example 5
Analysis of C5 Saccharide Compositions Using Gel Permeation Chromatography
[0257] The C5 saccharide compositions of the invention were prepared using supercritical, subcritical, and near critical water extraction in the first stage of the two stage process as described in Example 1. Representative samples bracketing the extremes/possibilities of reactor feed concentration (10.66-13.78 weight %, reactor temperature (249-261° C.), and reactor residence time (2-3 minutes) were selected.
[0258] The representative samples were analyzed using gel permeation chromatography (details below).
GPC Agilent HPLC System Configuration
[0259]
[0000]
Auto Sampler
1260 ASL
Pump
1260 isocratic pump Agilent
Heater
1260 TCC
Degasser
1260 degasser
Mobile Phase
DI water
Column
Ultrahydrogel-120, 250, 500 from Waters
(injection vol 25 μl, Size 7.8 × 300 mm) temp 30° C.
Flow Rate
0.5 ml/min; run time of 80 minutes
Detector
1260-RID set at 50° C. Agilent and DAD (signal 214
and 270 nm)
[0260] The area under each peak (indicating an individual mer unit in the saccharide) was measured to calculate weight % of each mer unit, based on the total weight of C5 saccharides present in the sample. The results are shown in the following table:
[0000]
C5
C5 ≧
monosac-
C5
C5
C5
C5
hexa-
charides
disaccharides
trisaccharides
tetrsaccharides
pentasaccharides
saccharides
(weight
(weight
(weight
(weight
(weight
(weight
Sample
%)
%)
%)
%)
%)
%)
7-0458
18.2
24.4
16.3
14.1
11.8
15.3
8-0550
17.0
21.8
16.2
11.6
13.0
20.3
9-0647
16.1
23.5
18.1
10.7
4.5
27.1
10-2144
17.2
23.6
17.6
10.4
9.4
21.9
11-2242
13.3
20.4
13.9
17.4
9.3
25.4
12-2348
13.4
19.3
14.7
13.0
9.5
30.1
Example 6
Analysis of C5 and C6 Saccharide Compositions Using HPLC with an Electrochemical Detector
[0261] The C5 and C6 saccharide compositions of the invention were prepared using supercritical, subcritical, and near critical water extraction in the two stage process as described in Example 1. Representative samples were selected.
[0262] The representative samples were analyzed using DIONEX HPLC (details below).
Dionex System Thermo Scientific Configuration
[0263]
[0000]
Auto Sampler
AS-AP
Pump
ICS-5000 DP (dual pulse)
Mobile Phase
100 mM NaOH (sodium hydrohyde) + deionized water
100 mM NaOH (sodium hydrohyde) + 1M NaOAc
(sodium acetate)
Column/Heater
CarboPac PA 200 3 × 250 mm temp 30° C.
with guard column CarboPac PA 200 3 × 250 mm
(injection vol 10 μl) and compartment temperature 30° C.
Flow Rate
0.5 ml/min; run time of 70 minutes
Detector
ICS-5000 DC Electro chemical detector
[0264] The results are averaged and shown in the tables below:
[0000]
DIONEX averaged results
(varying residence time in hemihydrolysis reactor; varying slurry loading)
Residence
Slurry
C5 monomer
C5
C5
C5
C5
C5
time
loading
(xylose)
dimer
trimer
tetramer
pentamer
hexamer
minutes
%
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
2
11.39
0.28835
6.9
1.7517
42.0
1.4432
34.6
0.0981
2.4
0.1817
4.4
0.4095
9.8
3
10.95
0.91497
19.8
1.6926
36.7
1.248
27.0
0.35397
7.7
0.2271
4.9
0.18023
3.9
[0000]
DIONEX averaged results
(varying slurry loading)
Residence
Slurry
C5 monomer
time
loading
(xylose)
C5 dimer
C5 trimer
C5 tetramer
C5 pentamer
C5 hexamer
minutes
%
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
2
11.39
0.28835
6.9
1.7517
42.0
1.4432
34.6
0.0981
2.4
0.1817
4.4
0.4095
9.8
2
12.24
0.3272
6.5
2.1768
43.0
0.7087
14.0
1.3541
26.8
0.223
4.4
0.2685
5.3
[0000]
DIONEX averaged results
(varying hemihydrolysis reactor total time)
Residence
Slurry
time
loading
C5 monomer
C5 dimer
C5 trimer
C5 tetramer
C5 pentamer
C5 hexamer
hours
%
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
1
10.95
1.7316
19.99
0.4674
5.4
3.1371
36.1
0.5831
6.7
0.0618
0.7
0.0139
0.2
2
10.95
0.489
13.5
2.2848
62.9
0.3536
9.7
0.2033
5.6
0.0679
1.9
0.2323
6.4
3
10.95
0.5243
12.4
2.3256
55.0
0.2533
6.0
0.2755
6.5
0.5516
13.1
0.2945
7.0
[0000]
DIONEX averaged results
(with and without quench post cellulose hydrolysis)
Total
C6 monomer
Rx T
Flow
(glucose)
C6 dimer
C6 trimer
C6 tetramer
C6 pentamer
C6 hexamer
° C.
Rate
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
With
374.2
1049.9
2.9
24.2
1.8
14.9
1.7
14.3
1.7
13.8
2.2
18.4
1.7
14.3
quench
Without
367.7
774.8
1.95
18.6
1.77
16.9
1.51
14.5
1.45
13.9
1.94
18.6
1.82
17.4
quench
[0000]
DIONEX averaged results
(with and without quench post cellulose hydrolysis; quench at 200° C.)
Total
C6 monomer
Rx T
Flow
(glucose)
C6 dimer
C6 trimer
C6 tetramer
C6 pentamer
C6 hexamer
° C.
Rate
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
With
383.4
766.6
0.9
25.5
0.6
15.5
0.6
16.9
0.5
13.7
0.5
14.9
0.5
13.5
quench
Without
379.0
796.3
1.59
15.5
0.23
2.2
2.24
21.8
1.95
19.0
2.13
20.7
2.13
20.8
quench
[0000]
DIONEX averaged results
(residence time in reactor)
Total
C6 monomer
Rx T
Flow
(glucose)
C6 dimer
C6 trimer
C6 tetramer
C6 pentamer
C6 hexamer
° C.
Rate
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
0.19
373.0
775.6
0.66
13.1
0.66
13.1
0.84
16.6
0.85
16.8
0.94
18.5
1.1059
21.9
seconds
1.22
374.2
1049.9
2.94
24.2
1.81
14.9
1.73
14.3
1.67
13.8
2.24
18.4
1.74
14.3
seconds
[0000]
DIONEX averaged results
(varying residence time in hemihydrolysis reactor; varying slurry loading)
Residence
Slurry
time
loading
C5 monomer
C5 dimer
C5 trimer
C5 tetramer
C5 pentamer
C5 hexamer
minutes
%
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
g/L
wt %
2
11.39
0.28835
6.9
1.7517
42.0
1.4432
34.6
0.0981
2.4
0.1817
4.4
0.4095
9.8
3
10.95
0.91497
19.8
1.6926
36.7
1.248
27.0
0.35397
7.7
0.2271
4.9
0.18023
3.9
[0265] When ranges are used herein for physical properties, such as molecular weight, or chemical properties, such as chemical formulae, all combinations, and subcombinations of ranges specific embodiments therein are intended to be included.
[0266] The disclosures of each patent, patent application, and publication cited or described in this document are hereby incorporated herein by reference, in their entirety.
[0267] Those skilled in the art will appreciate that numerous changes and modifications can be made to the preferred embodiments of the invention and that such changes and modifications can be made without departing from the spirit of the invention. It is, therefore, intended that the appended claims cover all such equivalent variations as fall within the true spirit and scope of the invention. | Compositions comprising C5 and C6 saccharides of varying degrees of polymerization and low levels of undesirable impurities, such as compounds containing sulfur, nitrogen, or metals, are disclosed. | 2 |
CLAIM OF PRIORITY
[0001] This application is a continuation-in-part of pending application Ser. No. 09/550,230, filed on Apr. 14, 2000, the entire disclosure of which is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for dynamically extending a firewall upon the establishment of a connection with a remote system, and in particular, to a firewall method that enables the rejection of network traffic from non-approved sources.
BACKGROUND OF THE INVENTION
[0003] Information systems are evolving to become the delivery mechanism that drives corporate revenues. In industries ranging from financial services to on-line shopping, the computer has become the business. Accordingly, protection of computer-based data is becoming of paramount importance to a corporation's financial well being.
[0004] Customer support for such information systems needs to be rapid. For mission-critical information systems, a delay of even a few hours while waiting for a service engineer to arrive to diagnose the system can be disastrously expensive. Attempts have been made to address this problem by providing a service network to which a computer system is able to connect. However, such systems can be expensive to create and maintain because they must be capable of connecting to each and every customer requiring support. Further, the identity and locations of clients seeking support changes rapidly, requiring constant reconfiguration of the service network.
[0005] Moreover, existing service networks have faced some resistance due to perceived security problems connection of client systems to the service provider's network limit the security of both networks. Accordingly, a robust service network that is dynamically configurable and secure is desirable.
SUMMARY OF THE INVENTION
[0006] The present invention provides a firewall technique that is dynamically extendible upon the establishment of connections with a remote system.
[0007] In one aspect the present invention relates to a method for dynamically extending a firewall. The method includes the step of establishing a connection with a remote system. A connection, in some embodiments a serial connection; is initiated with the remote system and the remote system assigns identifiers to the local system. In some embodiments, the identifier is an IP address transmitted to the client system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention is pointed out with particularity in the appended claims. The advantages of the invention described above, as well as further advantages of the invention, may be better understood by reference to the following description taken in conjunction with the accompanying drawings, in which:
[0009] [0009]FIG. 1 is a block diagram of an embodiment of a traditional computer system;
[0010] [0010]FIG. 2 is a block diagram of an embodiment of a redundant, fault-tolerant computer system;
[0011] [0011]FIG. 3 is a block diagram showing an embodiment of auxiliary connections between service management logic units, processors, and I/O controllers in the system of FIG. 2;
[0012] [0012]FIGS. 4 and 4A are block diagrams depicting an embodiment of the steps to be taken during initialization of a fault-tolerant computer system;
[0013] [0013]FIGS. 5 and 5A are screen shots depicting exemplary embodiments of user interfaces for controlling the booting process;
[0014] [0014]FIG. 6 is a block diagram depicting one embodiment of a service network;
[0015] [0015]FIG. 7 is a block diagram depicting one embodiment of a POP server as shown in FIG. 6;
[0016] [0016]FIG. 8 is a functional flow diagram of one embodiment of the steps to be taken to initiate a client connection from a service network;
[0017] [0017]FIG. 9 is a block diagram of one embodiment of the system management logic of FIG. 3;
[0018] [0018]FIG. 10 is a diagram showing the internals of one embodiment of the arbiter 930 of FIG. 9;
[0019] [0019]FIG. 11 is a state diagram of the PCI state machine 1000 of FIG. 10; and
[0020] [0020]FIG. 12 is a state diagram of the priority state machine 1002 of FIG. 10.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Referring now to FIG. 1, a typical computer 14 as known in the prior art includes a central processor 20 , a main memory unit 22 for storing programs and/or data, an input/output (I/O) controller 24 , a display device 26 , and a data bus 42 coupling these components to allow communication between these units. The memory 22 may include random access memory (RAM) and read only memory (ROM) chips. The computer 14 typically also has one or more input devices 30 such as a keyboard 32 (e.g., an alphanumeric keyboard and/or a musical keyboard), a mouse 34 , and, in some embodiments, a joystick 12 .
[0022] The computer 14 typically also has a hard disk drive 36 and a floppy disk drive 38 for receiving floppy disks such as 3.5-inch disks. Other devices 40 also can be part of the computer 14 including output devices (e.g., printer or plotter) and/or optical disk drives for receiving and reading digital data on a CD-ROM. In the disclosed embodiment, one or more computer programs define the operational capabilities of the system 10 . These programs can be loaded onto the hard drive 36 and/or into the memory 22 of the computer 14 via the floppy drive 38 . Applications may be caused to run by double clicking a related icon displayed on the display device 26 using the mouse 34 . In general, the controlling software program(s) and all of the data utilized by the program(s) are stored on one or more of the computer's storage mediums such as the hard drive 36 , CD-ROM 40 , etc.
[0023] System bus 42 allows data to be transferred between the various units in the computer 14 . For example, processor 20 may retrieve program data from memory 22 over system bus 42 . Various system busses 42 are standard in computer systems 14 , such as the Video Electronics Standards Association Local Bus (VESA Local Bus), the industry standard architecture ISA bus (ISA), the Extended Industry Standard Architecture bus (EISA), the Micro Channel Architecture bus (MCA) and the Peripheral Component Interconnect bus (PCI). In some systems 14 multiple busses may be used to provide access to different units of the system. For example, a system 14 may use a PCI to connect a processor 20 to peripheral devices 30 , 36 , 38 and concurrently connect the processor 20 to main memory 22 using an MCA bus.
[0024] It is immediately apparent from FIG. 1 that such a traditional computer system 14 is highly sensitive to any single point of failure. For example, if main memory unit 22 fails to operate for any reason, the computer 14 as a whole will cease to function. Similarly, should system bus 42 fail, the system 14 as a whole will fail. A redundant, fault-tolerant system achieves an extremely high level of availability by using redundant components and data paths to insure uninterrupted operation. A redundant, fault-tolerant system may be provided with any number of redundant units. Configurations include dual redundant systems, which include duplicates of certain hardware units found in FIG. 1, and triply redundant configurations, which include three of each unit shown in FIG. 1. In either case, redundant central processing units 20 and main memory units 22 run in “lock step,” that is, each processor runs identical copies of the operating system and application programs. The data stored in replicated memory 22 and registers provided by the replicated processors 20 should be identical at all times.
[0025] Referring now to FIG. 2, one embodiment of a redundant, fault-tolerant system 14 ′ is shown that includes three processors 20 , 20 ′, 20 ″ (generally 20 ) and at least two input output controllers 24 , 24 ′ (generally 24 ). As shown in FIG. 2, system 14 ′ may include more than two input output controllers ( 24 ″ and 24 ′″ shown in phantom view) to allow the system 14 ′ to control more I/O devices. In the embodiment shown in FIG. 2, four redundant system busses 42 , 42 ′, 42 ″ and 42 ′″ (generally 42 ) are used to interconnect each processor 20 and I/O controllers 24 . In one embodiment, processors 20 are selected from the “x86” family of processors manufactured by Intel Corporation of Santa Clara, Calif. The x86 family of processors includes the 80286 processor, the 80386 processor, the 80486 processor, and the Pentium, Pentium II, Pentium III, and Xeon processors. In another embodiment processors are selected from the “680x0” family of processors manufactured by Motorola Corporation of Schaumburg, Ill. The 680x0 family of processors includes the 68000, 68020, 68030, and 68040 processors. Other processor families include the Power PC line of processors manufactured by the Motorola Corporation, the Alpha line of processors manufactured by Compaq Corporation of Houston, Texas, and the Crusoe line of processors manufactured by Transmeta Corporation of Santa Clara, Calif.
[0026] Each processor 20 may include logic that implements fault-tolerant support. For embodiments in which CPU 20 is a single chip, the fault-tolerant logic may be included on the chip itself. In other embodiments, the CPU 20 is a processor board that includes a processor, associated memory, and fault-tolerant logic. In these embodiments, the fault-tolerant logic can be implemented as a separate set of logic on processor board 20 . For example, the fault-tolerant logic may be provided as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a programmable logic device (PLD), or a read-only memory device (ROM). The fault-tolerant logic compares the results of each operation performed by the separate processors 20 to the results of the same operation performed on one of the other processors 20 . If a discrepancy is determined then a failure has occurred.
[0027] Each input output controller may also include fault-tolerant logic that monitors transactions on the system busses 42 to aid in determining a processor failure. As shown in FIG. 2 , the I/O controller boards 24 also provide support for the display 26 , input devices 30 and mass storage such as floppy drives 38 , hard drives, and CD-ROM devices. The embodiment shown in FIG. 2 includes a front panel 52 that provides an interface to these input and output devices. In these embodiments, the front panel may serve as an adapter between the I/O controllers 24 and, for example, a universal serial bus (USB) used by keyboard and mouse input devices, or a video connector (EGA, VGA, or SVGA) used for connecting displays to the system 14 ′.
[0028] Each I/O controller 24 includes service management logic which performs various system management functions, such as: monitoring the operational status of the system; performing online diagnostics of the system; and providing an interface for remotely viewing system operation (including a processor boot sequence). In some embodiments, the service management logic includes a modem providing a serial line connection to a service network. In other embodiments, the service management logic includes a connection for communicating with other customer equipment, such as an Ethernet connection of other local area network connection. In some embodiments, the service management logic is provided as a separate board that is in communication with I/O controller 24 . In one particularly preferred embodiment, a service management board including all service management logic connects to I/O controller 24 via a PCI slot. The service management logic (referred to hereafter as SML) may be provided with a power supply separate from the remainder of the system 14 ′.
[0029] Referring now to FIG. 3, a block diagram shows the connection between SML units 50 , 50 ′ (generally 50 ) and the I/O controllers 24 , 24 ′ and processors 20 , 20 ′, 20 ″ of the system 14 ′. As shown by FIG. 3, each SML 50 is connected to each of the other units by redundant auxiliary busses 60 , 60 ′ in addition to redundant busses 42 . Auxiliary busses 60 , 60 ′ may be any bus that allows the SMLs 50 to control and query the processors 20 and I/O controllers 24 . The SMLs can communicate with the other units using a variety of connections including twisted pair, broadband connections, or wireless connections. Connections can be established using a variety of lower layer communication protocols such as TCP/IP, IPX, SPX, Ethernet, RS232, direct asynchronous connections, or I 2 C. In general, any message-oriented protocol may be used, and a check-summed, packet-oriented protocol is preferred.
[0030] Referring now to FIG. 4, the steps to be taken to boot a redundant, fault-tolerant system are shown. In brief overview, the boot process begins by powering on the SMLs (step 402 ), initializing and communicating with other SMLs in the system (steps 404 , 406 and 408 ), and determining whether or not the system requires booting (step 410 ).
[0031] In greater detail, and as noted above, SMLs 50 are provided with power separate from the power provided to the system 14 ′. Power is supplied to the SMLs (step 402 ) before any other units in the system 14 ′. For embodiments in which the SML is a portion of an I/O controller board 24 , power may be supplied to the entire I/O controller board 24 but only routed to the SML portion of the controller board 24 . For embodiments in which the SML is provided as a separate board, then only the SML is supplied with power. In either case, whether and when power is supplied to the other units in the system is under the direct control of the SML.
[0032] A SML uses auxiliary busses 60 , 60 ′ to determine if other SMLs exist in the system (step 404 ). If so, the SMLs exchange messages over the auxiliary busses 60 , 60 ′ in order to determine which SML will function as the primary SML for the system 14 ′ (step 406 ). The determination of which SML will function as the primary SML may include many factors, including: whether or not a service management logic unit has been previously inserted in the system to be powered up; and whether another SML has already been powered up and is operational. In other embodiments, the identity of the primary SML may be “hardwired.”
[0033] If an SML 50 determines that no other SML exists in the system 14 ′, or if an SML 50 has determined that it will function as the primary SML 50 for a system 14 ′ with multiple SMLs, the SML identifies with which I/O controller 24 it is associated (step 408 ). The SML 50 uses this information during the boot process to determine if another SML 50 should act as the primary SML 50 during the boot process. For example, if the I/O controller with which the SML 50 is associated is not selected for booting, then the SML 50 associated with the booting I/O controller must act as the primary SML 50 for the boot attempt. In other words, BIOS heartbeat and other boot status messages will be directed to the SML 50 on the booting I/O controller, even if that SML 50 is not the primary SML 50 .
[0034] Once an SML determines that it is the primary SML for a system 14 ′, it determines whether or not to boot the system 14 ′. SMLs 50 can exchange messages to negotiate which SML 50 is the primary SML 50 . If an SML 50 is already functioning in the system as primary, then a peer SML 50 becomes secondary. If neither SML 50 has yet been identified as the primary SML 50 , the SMLs 50 negotiate to determine which SML 50 is the primary SML 50 . In one embodiment the SMLs 50 negotiate to determine which SML 50 is the primary SML 50 . In one embodiment, the SMLs 50 negotiate using the following rules:
[0035] 1. If one SML 50 is “alien” to the system then the SML 50 which is not alien becomes primary. “Alien” means that the SML 50 was not resident in the computer system the last time it was used.
[0036] 2. If one SML 50 was primary more recently than the other, it becomes the primary again (and the other becomes secondary).
[0037] 3. As a default, the SML 50 in I/O board slot 0 becomes the primary SML 50 . The SML 50 in I/O board slot 1 becomes secondary.
[0038] A service management logic unit, in this embodiment, will not boot the system if it was explicitly shut down by an administrator (for example, if the administrator used a “power off” command to shut down the system). Whether or not a system has been explicitly shut down by an administrator may be stored in non-volatile memory (not shown in the drawings) that the SML 50 may query.
[0039] If a SML 50 determines that it should not boot the system 14 ′, it transitions to a state in which it monitors the system (step 412 ). This state is described in greater detail below. For example, an SML 50 may query a non-volatile memory element and discover that the system 14 ′ was properly and explicitly shut down by an administrator. In this case, the SML 50 will not attempt to boot the system 14 ′. Otherwise, the system moves to the boot process described in FIG. 4A.
[0040] The boot process shown in FIG. 4A may be commenced by an initializing SML 50 . Alternatively, the boot process may be directly invoked by a system administrator by, for example, a “boot” command. FIG. 5A is a screen shot showing an exemplary embodiment for providing such commands to the system administrator by the primary SML 50 . In this embodiment, system administration commands are grouped as a set of “tabs” and displayed to the administrator. The administrator selects the tab containing the desired operations. FIG. 5A depicts an embodiment in which a “System Control” tab 54 provides four controls for a system: a “Power On” command 56 (depicted in gray to indicate the system is currently running; an explicit “Power Off” command 58 ; a “Reset” command 60 ; and a “System Interrupt” command 62 . System information 64 , as well as information concerning the primary SML 66 , is provided to the administrator. In the embodiment shown in FIG. 5A, the administration commands are provided using a browser-based user interface. Although FIG. 5A depicts an embodiment using NETSCAPE NAVIGATOR, manufactured by Netscape Communications of Mountain View, Calif., any browser may be used, including MICROSOFT INTERNET EXPLORER, manufactured by Microsoft Corporation of Redmond, Wash. A third way for the boot process shown in FIG. 4A to be invoked is by an SML following a system failure. This mechanism is discussed in greater detail below.
[0041] The boot process begins by determining a “boot list” (step 450 ) FIG. 4A. A boot list is a list of component systems allowing the system to boot. For example, boot components may include processors, I/O controllers, BIOS, and other software (both application and system). In one particular embodiment, a boot list an ordered list of processor-I/O controller pairs. In some embodiments, the boot list includes “heartbeat” values associated with each boot pair. Heartbeat values are used by an SML 50 during system operation to determine if a processor 20 is functioning properly. Heartbeats are described in greater detail below. The boot list may be stored in a data structure that associates processor identification values with I/O controller values. For embodiments in which heartbeat values are also stored, the data structure includes an additional field to associate heartbeat timer values with each boot pair. The data structure may be stored on each SML 50 in a system 14 ′. In preferred embodiments, the data structure is stored in an non-volatile, erasable memory element, such as an EEPROM, that is accessible using auxiliary busses 60 , 60 ′. In the event that the stored data structure is inconsistent (for example the data structure may include corrupted data values), or if the SML 50 is unable to retrieve data from the memory element (for example, if no memory element exists or if both auxiliary busses 60 , 60 ′ are not functioning), the SML 50 may use a hard-coded default list.
[0042] [0042]FIG. 5B depicts a screen shot of an exemplary user interface allowing a system administrator to modify the default boot list. As shown in connection with FIG. 5A, the user interface is browser based and provides information to the administrator regarding the system 14 ′ and SML 50 currently active. Once the graphical user interface shown in FIG. 5B is used to create a boot list, it is saved to the non-volatile memory element.
[0043] Once a boot list is determined, whether by retrieving a list from a memory element or by using a default list, the SML 50 determines available processors 20 and I/O controllers 24 (step 452 ). The SML 50 may transmit a message over auxiliary busses 60 , 60 ′ to determine this information. Processors 20 and I/O controller 24 respond to the message transmitted by the SML 50 . The SML 50 concludes that a processor 20 or I/O controller does not exist if no response to the message is received on either bus 60 , 60 ′. This information is used by the SML 50 to skip pairs in the boot list if they reference units not present in the system 14 ′.
[0044] Once all system units are discovered by the SML 50 , the SML 50 provides system clocks to the processors 20 and the I/O controllers 24 (step 452 ). In other embodiments system clocks are not under the control of the SML 50 and, in these embodiments, step 452 may be skipped.
[0045] Using auxiliary busses 60 , 60 ′, the SML 50 asserts a reset signal associated with each processor 20 and I/O controller 24 (step 456 ). The SML 50 takes any other steps necessary at this point to prepare all system units for booting. For example, some units may need to have power applied or, for example, certain other signals may need to be asserted to prepare the unit for booting.
[0046] The SML releases reset from the processor 20 and the I/O controller 24 identified in the boot list as the first boot pair while holding reset active for all other system units (step 458 ). This allows the selected boot pair to boot in a manner consistent with a traditional computer. The SML 50 monitors the boot process of the selected boot pair to determine if the boot process is successful (step 460 ). In one embodiment, the SML 50 monitors the progress of the boot process by receiving heartbeat signals from the booting process-I/O controller pair. In one embodiment, heartbeats are transmitted over system busses 40 . Failure to receive a heartbeat signal within a predetermined time period indicates that the boot process has failed. If the boot process is not successful, the SML 50 selects a new boot pair from the boot list (step 462 ) and attempts to boot that processor-I/O controller pair. In some embodiments, the Basic Input-Output System (BIOS) may, during the boot attempt, determine that it cannot achieve a proper boot of the operating system , even though the processor has booted and is providing heartbeat signals to the SML 50 . In this case, the BIOS issues an explicit “reboot” command to the SML 50 and the SML 50 selects a new boot pair from the boot list.
[0047] If the SML 50 cycles through every pair identified in the boot pair list and none of the pairs is successful, the SML 50 indicates that the system 14 ′ was unable to boot. In some embodiments the SML 50 removes all power from the processors 20 and the I/O controllers 24 after determining the system 14 ′ is unable to boot.
[0048] If the boot process is successful, the BIOS transmits a message to the SML indicating that the operating system has booted properly. In this case, the SML transitions to a monitoring state (step 464 ). In some embodiments, after successfully booting the first processor-I/O pair the SML 50 boots each other processor 20 in the system 14 ′.
[0049] Once the booting process is complete, or if the SML 50 determines that the system 14 ′ should not be booted, the SML 50 enters a monitoring state (steps 412 or 464 ). In this state the SML 50 monitors heartbeat signals from each of the processors 20 to determine operation status of the system 14 ′. A failure to receive a heartbeat signal from a processor 20 during a predetermined period indicates that a failure has occurred. In this event, the SML 50 consults a non-volatile memory element to determine what actions, if any to take. The memory element may be the same memory element discussed above that stores the boot list, or a separate memory element may be provided that is accessible via the auxiliary busses 60 , 60 ′. In one embodiment, the memory element stores a value that indicates one of seven actions for the SML 50 to take upon heartbeat failure: (1) no action; (2) normal interrupt; (3) non-maskable interrupt; (4) stop processor from executing; (5) system reboot; or (6) deterministic boot. Each of these options is discussed in detail below.
[0050] A memory value indicating that the SML 50 should take no action on a heartbeat failure disables all recovery mechanisms. In some embodiments, the SML 50 logs the failure but otherwise does nothing.
[0051] A memory value indicating “normal interrupt” restricts recovery attempts by the SML 50 to issuing normal interrupts to the processor 20 or processors 20 that have ceased to transmit a heartbeat. In this embodiment, the SML 50 issues an interrupt to a target processor 20 via the auxiliary busses 60 , 60 ′. If the processor's operating system is able to process the interrupt, it responds by restarting heartbeat transmission. In some embodiments, the operating system ensures that lockstep processing is resumed. In other embodiments, the SML 50 issues interrupts to the processor or processors such that the processors resume lockstep operation. For example, interrupts may be issued to processors simultaneously which should avoid breaking lockstep. In some embodiments the operating system halts execution of all programs and allows a system administrator to debug system settings. If the operating system does not respond to the interrupt, then recovery fails. In some embodiments, the SML 50 simply logs this failure. In other embodiments, the SML 50 alerts an administrator that the system 14 ′ will not respond.
[0052] A memory value indicating “non-maskable interrupts” restricts recovery attempts by the SML 50 to issuing normal and non-maskable interrupts to the processor 20 or processors 20 that have ceased to transmit a heartbeat. In this embodiment, should the system 14 ′ refuse to respond to a normal interrupt, the SML 50 issues a non-maskable interrupt to a target processor 20 via the I/O controller 24 . If multiple processors 20 are hung, non-maskable interrupts are issued to all processors 20 in lockstep to avoid breaking processor lockstep. If the processor's operating system is able to process the non-maskable interrupt, it responds by restarting heartbeat transmission. In this case, the SML 50 must revoke the previously issued normal interrupt. In some embodiments the operating system halts execution of all programs and allows a system administrator to debug system settings. If the operating system does not respond to the non-maskable interrupt, then recovery fails. In some embodiments, the SML 50 simply logs this failure. In other embodiments, the SML 50 alerts an administrator that the system 14 ′ will not respond.
[0053] A memory value indicating that processor execution should be suspended allows the SML 50 , in the event that a non-maskable interrupt fails to restore system operation, to select a processor 20 and suspend execution of all applications and the operating system by that processor 20 . Processor and memory state of the suspended processor is not destroyed. If heartbeat signals resume from the other processors once the selected processor 20 is suspended, recovery has been successful. The state of the suspended processor 20 may be dumped for analysis, the state of the suspended processor may be replaced with state from one of the operational processors 20 , or both. If this step fails to restore the system 14 ′ to operational status, the SML 50 may dump the state of the suspended processor 20 for analysis by a system administrator, log the failure, alert an administrator to the failure, or any combination of these actions.
[0054] A memory value indicating “system reboot” allows the SML 50 to attempt to reboot the system in the event that suspended a selected processor 20 does not succeed. The reboot process is similar to the reboot process described in connection with FIGS. 4 and 4A, except that the suspended processor 20 is skipped during reboot of the boot pairs listed in the boot list. To avoid repetitive heartbeat failure, the SML 50 maintains an index to identify the last processor-I/O boot pair in the boot list that last rebooted successfully. During the reboot process, this index is incremented to ensure that a different pair is selected as the starting pair each time. If successful, the state of the suspended processor 20 may be dumped for analysis, the state of the suspended processor 20 may be replaced with the state of one of the operational processors, or both. As above, if this mechanism doesn't succeed in restoring the system 14 ′ to operational status, the SML 50 may dump the state of the suspended processor 20 for analysis by a system administrator, log the failure, alert an administrator to the failure, or any combination of these actions.
[0055] A memory value indicating “deterministic boot” allow the SML 50 to abandon the state of the suspended board and perform a full deterministic reboot, as described in connection with FIGS. 4 and 4A.
[0056] Referring now to FIG. 6, the system management features of the SML 50 can be extended by providing the SML 50 with the capability of connecting to a service network 100 . The service network allows support personnel 182 to access, configure, or otherwise manipulate connected computer systems 14 ′ via their respective SMLs 50 . The service network 100 also allows the SML 50 to report specific problems or failures it has detected with the system 14 ′. An example of the types of failures reported are those resulting from failure of a heartbeat signal, as described above.
[0057] The embodiment of a service network 100 shown in FIG. 6 includes two remote “points of presence” 110 , 110 ′ 0 and a centralized support provider network (SPN) 180 . Points of presence 110 , 110 ′ provide geographically localized access to the centralized network 180 . For example, the centralized SPN 180 may be located in Glasgow, Scotland. Point of presence 110 may be located in Boston, United States of America. In this embodiment, POP 110 provides a computer system 14 ′ in Boston with access to the SPN 180 in Scotland while avoiding the expense attendant with making a direct connection to the SPN 180 in Scotland. POPs 110 , 110 ′ connect with the centralized SPN 180 through a firewall 112 , 112 ′. Firewalls 112 , 112 ′ secure the SPN 180 against malicious client-side activity.
[0058] Each POP 110 , 110 ′ includes a POP server 114 , 114 ′ that is responsible for establishing and managing network connections to individual computer systems 14 , 14 ′ and an address server 118 ′ that manages the assignment of IP addresses to computer systems 14 ′. In one embodiment, the address server 118 ′ is a Dynamic Host Configuration Protocol (DHCP) server. In another embodiment, the address server 118 ′ is a customized server application. In the embodiment shown in FIG. 6, computer systems 14 , 14 ′ establish network connections with modem banks 116 , 116 ′ using a serial line protocol, such as the Point-to-Point (PPP) protocol or the Serial Line Internet Protocol (SLIP). The POP servers 114 , 114 ′ also establish packet routing and filtering functions to allow service personnel 182 connecting through the SPN 180 to access remote computer systems 14 , 14 ′. Although only two POPs 110 , 110 ′ are shown in FIG. 6, it should be understood that any number of POPs may be used to achieve geographic dispersity.
[0059] The address server 118 receives a request for an IP address to the requester and returns an IP address that is available for assignment. The address server maintains a pool of IP addresses, the range for which may be configured during address server 118 setup. The pool of IP address may be maintained as a text file, array of integers, linked list, or a doubly linked list. For embodiments in which the address server 118 is provided as a DHCP server, administration of the server 118 may be done using standard management tools provided by WINDOWS 2000.
[0060] Referring now to FIG. 7, a POP server 114 , 114 ′ is depicted in greater detail. In brief overview, a POP server 114 , 114 ′ includes a remote access module 120 , a local database 122 , an authentication server module 124 , and a connection server module 126 .
[0061] The remote access module 120 establishes and manages connections with computer systems 14 , 14 ′. The remote access server 120 may establish PPP connections for computer systems 14 , 14 ′ either as an incoming call placed to the POP 100 by the system 14 or as an outgoing call placed by the POP 100 to the system 14 . In some embodiments, the remote access module 120 places a call to a system 14 , authenticates itself to the system 14 , and then terminates the call. In these embodiments, the system 14 places a return call to the POP 100 to establish a connection. The POP 100 may authenticate itself using predefined passwords, shared secrets, or public key infrastructure techniques.
[0062] The remote access module 120 communicates with an authentication server module 124 to authenticate systems 14 . The remote access module 120 monitors the state of all system connections and reports those changes to the connection server module 126 . In certain embodiments, the remote access module 120 is provided as the RRAS portion of WINDOWS 2000, manufactured by Microsoft Corporation of Redmond, Wash. In other embodiments, the remote access module 120 is provided by a modified version of RRAS that supports the management of connections across multiple servers.
[0063] The authentication server module 124 verifies the authentication credentials of systems 14 and support personnel 182 seeking access to the POP 100 . In one embodiment, the authentication server module 124 verifies a username and password against a password database stored in the database 122 . In other embodiments, the authentication server module 124 verifies an encryption key, digital certificate, or digital signature. In other embodiments, the authentication server module 124 includes accounting functionality that tracks accounting statistics relating to connections or connection attempts. In one embodiment, the authentication server module is provided as the INTERNET AUTHENTICATION SERVICES module of WINDOWS 2000 manufactured by Microsoft Corporation of Redmond, Wash. Once the system 14 or support personnel 182 is authenticated, the authentication server module 124 transmits a request for an IP address to the address server 118 .
[0064] The database 122 stores information associated with connections. In some embodiments, the database 122 stores information associated with active connections, such as time of connection, frequency of connection requests, and address associated with particular requests. The database 122 can be provided as an ODBC-compliant, flat file, multidimensional, or relational database.
[0065] The connection server module 126 manages connections to systems 14 ′ and requests from the centralized SPN 180 . For example, in some embodiments the connection server module 126 maintains reference count values and idle timeout values for connections to determine if a particular connection may be terminated due to inactivity and notifies the SPN 180 when a connection is broken. The remote access module 120 communicates with the connection server module 126 through an Application Programming Interface. In some embodiments, the connection server module 126 API is provided as a dynamically linked library.
[0066] The connection server module 126 manages and directs the allocation of IP addresses to connections between the POP 100 and the system 14 . The connection server module 126 is given an IP address by the address server 118 , makes routing changes to assign that address to a connection, and transmits the address to SML 50 on the system 14 .
[0067] Connection requests from the centralized SPN 180 may originate directly from service personnel 182 or they may originate from the connection server module 126 ′ of another POP server 114 ′. The SPN 180 and the various POPs 100 may communicate using a variety of connections including standard telephone lines, LAN, or WAN links (e.g., T1, T3, 56 kb, X.25), broad band connections (ISDN, Frame Relay, ATM) and wireless connections. Connections may be established using a variety of lower layer communication protocols (e.g. TCP/IP, IPX, SPX, NetBIOS, Ethernet, RS232, and direct asynchronous connection). In one embodiment, TCP/IP is used to communicate connection requests from the SPN 180 to the POP server 114 .
[0068] Referring now to FIG. 8, the functional flow diagram depicts the operation of the described service network when allowing service personnel 182 connections to systems 14 . Service personnel 182 request connection to a system 14 (step 802 ). The service person 182 provides an identifier of the system to which the connection is desired, as well as authentication credentials such as a user name and password or a digital certificate. The request is transmitted through the centralized SPN 180 to a POP 100 . The target POP 100 may be predetermined, selected by the service person 182 , or selected on the basis of information included in the identifier. For example, in some embodiments the centralized SPN 180 maintains a database of identifiers and associated POP addresses. When a request to connect to a particular site is received, the identification information is used to lookup the address of the POP 100 with which the system 14 is associated. In certain embodiments, POP 100 associated with certain geographical regions and are identified by IP addresses.
[0069] The connection server module 126 of the identified POP 100 receives the connection request and validates the information associated with that request (step 820 ). If the authentication credentials associated with the request are not validated, the connection server module 126 denies access to the POP 100 and returns a denial message to service personnel 182 . If the authentication credentials associated with the request are valid, then the connection server module 126 registers the request (step 822 ). The request registration is stored in the database 122 and associated with an identifier. The identifier allows the connection request to be identified for use in subsequent communications. In some embodiments, other information is stored with the request such as the time and the system to which the request connection is made. The connection server module 126 returns a successful status message (step 824 ) to the service personnel 182 .
[0070] The connection server module checks the database 122 to determine if the connection to the identified system 14 already exists (step 826 ). If a local connection already exists, then the connection server module 126 activates the connection, and selects one or more address filters (step 840 ), and the address filters are sent to the remote access module. In response to this message, the remote access module 120 sets the address filters (step 884 ). For example, in some instances the address filters are IP filters.
[0071] IP filters provide the client system 14 with security against SPN-side malicious activity, since the filters can be set to reject all packets except those from the SPN 180 . If no local connection to the system 14 exists then the connection server module 126 broadcasts a message to all other POPs 100 connected to the centralized SPN 180 . The broadcast message polls the other connection server modules 126 to determine if they have existing connection to the desired system 14 . The transmitted poll request include the authentication credential from the request.
[0072] Each of the other remote connection server modules 126 ′ validates the poll request 870 and checks for a local connection by querying their respective databases 122 ′. If no local connection exists, then the remote connection server module 126 ′ does not respond to the broadcast message. Otherwise, the remote connection server module locks the connection to the system 14 (step 874 ) and sends a message to the connection server module 126 indicating that a local connection exists with the system 14 (step 876 ).
[0073] The connection server module 126 determines if a response has been transmitted to its polling requests (step 830 ). In some embodiments, the connection server module 126 waits a predetermined amount of time and if no response is received in that period of time, it is assumed that no response to the poll has been received. If no response is received, that indicates that no POP 100 has a local connection to the desired system 14 and the connection server module 126 determines which connection server module 126 is the appropriate connection server module to initiate a local connection with the desired system 14 . In some embodiments, this determination can be based on geographical location, i.e., which connection server module 126 is the nearest to the desired system 14 . In other embodiments, this determination can be on the basis of the current processing activity in each POP 100 . If the connection server module 126 determines that it is the appropriate connection server module to initiate the local connection, then it initiates a connection with the desired system 14 .
[0074] If the connection server module 126 determines that it is not the appropriate connection server module to initiate the local connection then connection server module 126 returns status to the service personnel 182 indicating that its request should be redirected to the identified connection server module 126 ′ and the service personnel 182 transmits a connection request to the identified POP 100 (step 802 ).
[0075] In some embodiments, when the connection server module 126 determines that it is not the appropriate connection server module to initiate the local connection, then the status message returned by the connection server module 126 causes the software used by service personnel 182 to automatically transmit a connection request to the identified POP 100 .
[0076] Referring back to step 880 , the remote access module 120 initiates a connection with the desired system 14 . The system 14 requests authentication information (step 890 ) which is transmitted by the remote access module 120 (step 882 ). The system 14 authenticates the request and, the authentication credentials are valid, allows access to the system 14 . In some embodiments, the system 14 terminates the serial connection (step 894 ) upon authentication and initiates a return serial connection based on the validated authentication credentials (step 896 ).
[0077] Once a system connection has been successfully established, the remote access module 120 requests an IP address from the authentication server module 124 . The requested IP address is transmitted to the SML 50 on the client system 14 . In some embodiments, the IP address is transmitted using a remote procedure call. The assigned IP address allows communication with the system 14 to occur over the centralized SPN 180 and the POPs 100 rather than the public Internet. In some embodiments, two IP addresses are assigned to a system 14 ; one identifies the system 14 ; and a second IP address identifies the SML 50 .
[0078] Once a system connection has been successfully established, the remote accesss module 120 assigns an IP address to the SML 50 on the client system. The assigned IP address allows communication with the SML 50 over the centralized SPN 180 and the POPs 100 rather than the public Internet. In some embodiments, two addresses are assigned: one to the SML 50 and one to the system 14 . In one embodiment, the IP address assigned to the system 14 is done through a remote procedure call.
[0079] The SML 50 uses the IP address transmitted to it by the remote access module 120 to control traffic at the client system 14 . IP filtering allows the SML 50 to block packets having associated addresses that are not intended for the system 14 .
[0080] In one detailed embodiment, the system 14 makes a connection to the POP/centralized SPN as follows:
[0081] 1. If the system 14 is initiating the connection, it performs a remote procedure call (“RPC”) to the SML 50 instructing it to establish a PPP connection to the POP/centralized SPN. The SML 50 can also initiate a connection for its own connection.
[0082] 2. The SML 50 dials the POP/centralized SPN on its modem.
[0083] 3. A POP/centralized SPN answers, the system 14 is authenticated and identified by the remote access module 120 . A PPP session is established between the POP/centralized SPN and system 14 .
[0084] 4. During the establishment of the PPP connection, IP address T2 is assigned to the SML's 50 modem interface.
[0085] 5. A POP/centralized SPN performs an RPC to the SML 50 to send a newly-assigned IP address T1 for the system 14 .
[0086] 6. The SML 50 receives the system IP address T1 from the POP/centralized SPN and modifies its routing table to allow packets coming from a POP/centralized SPN to be sent to the system IP address T1.
[0087] 7. The SML 50 passes the system IP address T1 onto the system via a RPC.
[0088] 8. The system assigns this address to the system 14 side of the SML 50 virtual network interface.
[0089] 9. The POP/centralized SPN performs a RPC to the SML 50 to send a delivery IP address.
[0090] 10. The SML 50 takes note of the delivery IP address, and passes it onto the system 14 via a RPC.
[0091] 11. The system note of the delivery IP address.
[0092] 12. The remote access module 120 registers the connected user (i.e., it makes note of the connection so that any request to attach to the site is directed to the existing connection).
[0093] 13. Depending on the firewall architecture, the remote access module 120 may also communicate with the firewall to explicitly allow packets from the connected system through to the POP/centralized SPN.
[0094] 14. At this stage an IP connection now exists between the POP/centralized SPN and customer system 14 .
[0095] Outgoing (POP/centralized SPN to Customer system) connections are established as follows:
[0096] 1. The POP/centralized SPN initiates a PPP connection to the SML 50 by dialing the SML's 50 modem.
[0097] 2. The SML's 50 modem answers, POP/centralized SPN is authenticated and the PPP connection is up.
[0098] 3. The SML 50 takes note of the user that connects, and terminates the PPP connection.
[0099] 4. The SML 50 retrieves the dial-back phone number for that user, and dials its modem.
[0100] 5. A POP/centralized SPN answers, the system 14 is authenticated and identified by the remote access module 120 . A PPP session is established between the POP/centralized SPN and system 14 .
[0101] 6. During establishment of the PPP connection, IP address T2 is assigned to the SML's 50 modem interface.
[0102] 7. A POP/centralized SPN performs an RPC to the SML 50 to send a newly-assigned IP address T1 for the system 14 .
[0103] 8. The SML 50 receives the system IP address T1 from the POP/centralized SPN and modifies its routing table to allow packets coming from a POP/centralized SPN to be sent to the system IP address T1.
[0104] 9. The SML 50 passes the system IP address T1 onto the system via a RPC.
[0105] 10. The system assigns this address to the system 14 side of the SML 50 virtual network interface.
[0106] 11. The POP/centralized SPN performs an RPC to the SML 50 to send a delivery IP address.
[0107] 12. The SML 50 takes note of the delivery IP address, and passes it onto the system 14 via a RPC.
[0108] 13. The system takes note of the delivery IP address.
[0109] 14. The POP/centralized SPN performs an RPC to the SML 50 to send the IP address B2 of the service system.
[0110] 15. The SML 50 receives the service system IP address B2 from the POP/centralized SPN and modifies its routing table to allow packets intended for the service system to be sent via the PPP interface.
[0111] 16. The SML 50 passes the service system IP address B2 onto the host via RPC.
[0112] 17. The system 14 modifies its routing table to allow packets intended for the service system to be sent via the shared memory interface.
[0113] 18. The remote access module 120 registers the connected user (i.e., it makes note of the connection so that any request to attach to the site is directed to the existing connection).
[0114] 19. Depending on the firewall architecture, the remote access module 120 may also communicate with the firewall to explicitly allow packets from the connected system through to the POP/centralized SPN.
[0115] 20. At this stage an IP connection now exists between the POP/centralized SPN and customer system 14 . Firewall functionality is implemented by the SML 50 rejecting any packet not addressed to T1 or T2, since only the customer system 14 and the POP/centralized SPN know addresses T1 and T2.
[0116] Additional steps are required to implement firewall functionality when the customer system 14 uses the Microsoft WINDOWS operating system. To communicate successfully through the firewall functionality, packets sent from the customer system 14 to the POP/centralized SPN must bear source address T1. If instead the packets bear the permanent address P1 of the customer system 14 , then packets sent to the customer system 14 from the POP/centralized SPN will be rejected by the SML 50 .
[0117] The Microsoft WINDOWS operating system assigns the source address of packets based on the address of the default gateway to the POP/centralized SPN stored in the WINDOWS routing table. Since this gateway is the SML 50 , the gateway address will either be T2 or the permanent address P2 of the SML 50 side of the virtual network interface. If the address is T2, then the packet source address will be T1 which, as discussed above, is the desired source address. If instead the gateway address is P2, then WINDOWS will assign P1 as the source address of the packets, which will not pass the firewall functionality.
[0118] However, the desired value T2 cannot be used as the default gateway in the WINDOWS routing table because the SML 50 will not respond to Address Resolution Protocol (ARP) requests using the T2 address coming from the client system 14 side of the SML 50 . The PPP interface bearing the T2 address is on the POP/centralized SPN side of the SML 50 and is not associated by the SML 50 with the client system 14 side of the SML 50 . That is, the SML 50 is only responsive to ARP requests using the T2 address that come from the POP/centralized SPN side of the SML 50 .
[0119] Thus, the permanent address P2 of the virtual network interface of the SML 50 must be used as the gateway in the routing table, which prevents the source address of the packets from being set to T1, the proper source address.
[0120] In one embodiment, this problem is solved by assigning temporary address T4 to the SML 50 side of the virtual network interface which, as discussed above, is also identified with address P2. The use of T4 as the default gateway lets WINDOWS set the source address of packets from the client system 14 to T1 and, unlike the earlier scenario, the SML 50 will recognize and respond to ARP requests directed to the T4 address and coming from the client system 14 side of the SML 50 .
[0121] Once a connection has been established with a client system 14 , service personnel 182 can perform various operations on system 14 or access various parts of system 14 to monitor the system. Regardless of whether the SML 50 is in a boot or active state, it is in some embodiments useful for system personnel 182 to access video data corresponding to messages normally displayed on the display 26 of the system 14 ′. Such messages can provide valuable indicia of the state of the system 14 ′ as well as each of its installed elements. For example, BIOS messages typically indicate the version of the BIOS that may or may not be compatible with the hardware version of the system 14 ′. BIOS messages can also indicate whether there is an incompatibility between the CPU versions in multiprocessor configurations that may affect the operations of the system 14 ′. Another type of fault indicia includes messages from I/O controllers 24 that indicate if the BIOS of the I/O controller 24 has been loaded and that also provide the status and configuration information for devices that it controls. Other types of fault indicia typically displayed on the display 26 of the system 14 ′ include POST codes, memory contents, messages from software drivers, hardware and software interrupt messages, diagnostics results, etc.
[0122] In one embodiment and with reference to FIG. 9, the SML 50 comprises a PCI/PCI bridge 910 , a VGA chip set 920 with associated VRAM 922 , an arbiter 930 , a PCI/Processor bridge 940 , a processor 950 , an inter-integrated circuits serial interface (I 2 C) 952 , a memory 954 , and a network interface 956 . The PCI/PCI bridge 910 , such as a DEC 21153 PCI-PCI bridge/isolator, extends the system PCI bus 42 so that PCI devices on a local PCI bus 942 and sited on the SML 50 have visibility to the system 14 ′. An example of a PCI device that can be located on the SML 50 and which communicates via the local PCI bus 942 is the VGA chip set 920 , such as the Cirrus Logic CL-GD5446 VGA controller. The VGA chip set 920 processes and renders the video data stored in the VRAM 622 for subsequent display on the server's display 26 .
[0123] The PCI/Processor Bridge 940 (e.g., Tundra QSPAN PCI to Host bridge) enables the processor 950 (e.g., MPC860T I/O microprocessor and PowerPC core) to communicate with local and system PCI devices over a local processor bus 944 (e.g., Qbus). When performing a monitoring function, the processor 950 executes instructions stored in the memory 954 and accesses system and component information of the system 14 ′ via I 2 C logic 952 that has visibility on an I 2 C bus, via the system PCI bus 42 , and via the local PCI bus 642 . The processor 950 can also provide data to and receive instructions from a remote administrator via the network interface 956 .
[0124] As previously discussed, the SML 50 enables a remote administrator to access messages displayed on the display 26 of the system 14 ′ in support of a troubleshooting session. Since the processor 950 has access to the VRAM 922 of the VGA chip set 920 via the local PCI bus 942 , the processor 950 can programmatically read and write to VGA I/O and memory space. In one embodiment, the capture of the video data stored in the VRAM 922 involves the following steps: store the state of key VGA registers (not shown) in the VGA chip set 920 , set the appropriate VGA registers to enable access to the VRAM 922 , perform the VRAM 922 memory accesses, and restore the VGA register state for the system 14 ′.
[0125] Remote VGA accesses by the administrator via the local PCI bus 942 result in the modification of the VGA registers and thus may result in a conflict when concurrent data access requests are received from the system 14 ′. The conflict introduced by concurrent accesses from the system 14 ′ (such as by CPU 20 ) and the processor 950 of the SML 50 can result in a corrupted VGA state or in an inability to read video data from the VRAM 922 . This problem is resolved in one embodiment, through the use of a customized arbiter 930 that provides an additional pin that, when asserted by a blocking command issued by the processor 950 , ignores/blocks requests from the PCI/PCI bridge 910 and thus enables the processor 950 to obtain exclusive access to the VGA chip set 920 . The arbiter may be provided as a programmable logic device (PLD), field-programmable gate array (FPGA), or application-specific integrated circuit (ASIC). The processor 950 can then complete the transactions requested by the administrator, reset the VGA registers for subsequent use by CPU 20 , and then issue a signal/command to the arbiter 930 that undoes the previous blocking command and enables the VGA chip set 920 to service data access requests received from the PCI/PCI bridge 910 .
[0126] In one embodiment, referring to FIG. 10, the arbiter 930 includes two state machines: a PCI state machine 1000 that arbitrates access to the local bus 42 and a priority state machine 1002 that addresses blocking commands issued by the processor 950 . The GRANT signal of the PCI state machine 1000 passes through the priority state machine 1002 , which in turn decides whether the system 14 or the processor 950 has access to the VGA chip set 920 .
[0127] In one embodiment, referring to FIG. 11, in normal operation the PCI state machine 1000 has four internal states and a register. When the arbiter 930 is powered on or receives a reset signal, the PCI state machine 1000 enters the Assert Grant Idle (AGI) state 1100 . In the AGI state 1100 , a default device (at power up) or the last granted device (when entering from another state) controls the bus 42 until a request occurs. When entering this state the GRANT signal is asserted and the register is updated with the ID of the device being granted. As long as the bus 42 is idle, no error conditions occur, and the device requesting the bus 42 is the one currently controlling the bus 42 , the PCI state machine 1000 does not change its state.
[0128] If a device other than the currently granted device requests the bus 42 and the bus is idle, then the PCI state machine 1000 will transition to the Deassert Grant Idle (DGI) state 1102 through transition 1108 . If a device other than the currently granted device requests the bus 42 and the bus is not idle, then the PCI state machine 1000 will transition to the Deassert Grant Not Idle (DGNI) state 1104 through transition 1110 . These states are described in more detail below. The state of the bus 42 determines the next state of the PCI state machine 1000 because the grant lines need to be deasserted for one clock cycle before another device's request can be granted. On the other hand, if the bus 42 becomes busy and there are no requests or the only requests are from the device currently granted, then the PCI state machine 1000 will transition from AGI state 100 into the Assert Grant Not Idle (AGNI) state 1106 through transition 1112 .
[0129] The AGNI state 1106 may be entered from the AGI, DGI, or DGNI states. When entering this state the GRANT signal is asserted and the register is updated with the ID of the device being granted. If the bus 42 goes idle and a request from a device other than the currently-granted device is received, the PCI state machine 1000 transitions into the DGI state 1102 through transition 1114 to avoid potential contention on the bus 42 when granting to another device. If the bus 42 becomes idle or is requested by the currently-granted device, then the PCI state machine 1000 transitions back to its initial AGI state 1100 through transition 1116 . On the other hand, if a request comes from a device that is not the currently-granted device without the bus 42 going idle, then the PCI state machine 1000 transitions to the DGNI state 1104 through transition 1118 , performing hidden arbitration as discussed below.
[0130] The DGI state 1102 is necessary to allow for turnaround when re-assigning the bus 42 to avoid bus contention. This state can only be entered from an asserted state (i.e., AGI state 1100 or AGNI state 1106 ) when the bus 42 goes idle and a device other than the currently-granted device requests the bus 42 . In these cases, the bus 42 is deasserted upon entering this state and the initial AGI state 1100 is entered through transition 1120 . On the next transition, the PCI state machine 1000 will change to either of the asserted states (i.e., AGI state 1100 through transition 1120 or AGNI state 1106 through transition 1122 ), depending on whether or not the bus 42 is idle.
[0131] The DGNI state 1104 essentially serves the same function as the DGI state 1102 , permitting transition to both asserted states (i.e., AGI state 1100 and AGNI state 1106 ). The transition to AGNI state 1106 permits the arbiter 930 to support hidden arbitration, since the bus 42 will have been granted to a new device without ever going idle. If the bus 42 goes idle while in this state, the PCI state machine 1000 transitions to the default or initial state through transition 1124 until a new transaction is initiated. If the bus 42 is not idle, then the PCI state machine 1000 transitions to the AGNI state 1106 through transition 1126 until a new transaction is initiated. This state can be entered from either of the asserted states (i.e., AGI state 1100 or AGNI state 1106 ) depending on whether the bus 42 is idle and which device is requesting the bus 42 .
[0132] The GRANT signal from the PCI state machine 1000 is an input to the priority state machine 1002 . The blocking command from the processor 950 is a second input to the priority state machine 1002 , which operates so as to prevent the system 14 ′ from accessing the VGA chipset 920 when the blocking command is asserted. Referring to FIG. 12, after a reset, the priority state machine 1002 is in HOST1 state 1200 , whereby the system 14 ′ may access the VGA chip set 920 through the bus 42 . If the system 14 ′ has higher priority and does not need to be blocked and the grant signal is asserted, then the priority state machine 1002 transitions to the HOST2 state 1202 through transition 1206 . If the grant signal is not asserted, the priority state machine 1002 remains in HOST1 state 1200 through transition 1208 .
[0133] The priority state machine 1002 remains in HOST2 state 1202 through transition 1218 as long as grant is not asserted. When grant is asserted, the priority state machine 1002 transitions from HOST2 state 1202 to LOCAL state 1204 through transition 1220 .
[0134] If the priority of the system 14 ′ is equal or the processor 950 has issued a blocking request and grant is asserted, then the priority state machine 1002 transitions from HOST1 state 1200 to LOCAL state 1204 through transition 1210 . In LOCAL state 1204 , the system 14 is blocked from accessing the bus 42 . As long as the system 14 ′ must be blocked, the priority state machine stays in LOCAL state through transition 1212 . When blocking is no longer necessary, the finite state machine transitions to HOST1 mode through transition 1214 or HOST2 mode through transition 1216 , depending on whether the system 14 has priority. Video may then be transmitted to service personnel 182 using an appropriate video transmission protocol, such as the Virtual Network Computing (VNC) protocol.
[0135] Having described certain embodiments of the invention, it will now become apparent to one of skill in the art that other embodiments incorporating the concepts of the invention may be used. In particular, the functional divisions made in connection with the block diagrams of the present discussion have been made to enhance clarity of the discussion, and other divisions or integrations of the described functions are within the scope of the invention. Therefore, the invention should not be limited to certain embodiments, but rather should be limited only by the spirit and scope of the following claims. | A method for dynamically-extending a firewall includes a step of receiving an identifier from a remote system. The identifier is used locally to accept packets of information with matching identifiers, rejecting packets whose identifiers do not match. | 7 |
RELATED APPLICATIONS
This application claims priority to Taiwan Application Serial Number 96100979, filed Jan. 10, 2007, which is herein incorporated by reference.
FIELD OF THE INVENTION
This invention relates to a manufacturing method for integrating at least one passive component within a substrate, and more particularly, to a method for positioning the passive component in the substrate in advance.
BACKGROUND OF THE INVENTION
For electronic devices today, the need of functionality and small size has gradually increased, and thus designers and suppliers thereof have to integrate more electronic devices into a package system. As to chip package, multi-chip module (MCM) or system-in-package (SIP) may provide the resolution of the foregoing problem. If MCM or SIP cooperated with embedding technique is used for integrating the Surface Mount Technology (SMT) passive components into a package substrate, more space on the surface of the substrate can be enhanced. Further, for the integrity of signal, in high frequency circuit design, the parasitic effect of electronic devices is a great issue. Compared with SMT passive components, an ideal embedded passive component has shorter connection therein, and thus has less parasitic effects. Therefore, the embedded passive component is suitable for the high frequency circuit design, and is important for the passive component design in the further.
Currently, when integrating the passive component into a substrate, the passive component is laminated within the substrate, and then the substrate is drilled for electrical connection. However, the position of drilling is predetermined, and if the position of the passive component is not accurate and precise, the position of drilling can not position to the electrical contact of the passive component. Therefore, the electrical connection of the passive component can not be achieved, thus affecting the product's yield significantly.
SUMMARY OF THE INVENTION
Therefore, an aspect of the present invention is to provide a manufacturing method for integrating at least one passive component within a substrate to prevent positioning error of the passive component therein, thereby enhancing the process yield thereof.
Another aspect of aspect of the present invention is to provide a manufacturing method for integrating at least one passive component within a substrate, whereby the passive component is positioned and electrically connected to a circuit layer on the substrate via an adhesive conductive material.
According to an embodiment of the present invention, the manufacturing method for integrating at least one passive component within a substrate comprises: providing at least one circuit layer, wherein at least one positioning blind hole is formed in the circuit layer; forming a conductive material in the positioning blind hole; positioning the passive component to the positioning blind hole of the circuit layer and electrically connecting the passive component to the circuit layer via the conductive material in the positioning blind hole; and laminating a core layer, the passive component and the circuit layer as the substrate, wherein the passive component is embedded in the core layer
According to another embodiment of the present invention, the foregoing conductive material is adhesive.
Therefore, with the application of the method disclosed in the embodiments of the present invention, the passive component can be positioned on the circuit layer and electrically connected thereto via a conductive material in the positioning blind hole before a laminating step, wherein the conductive material may be adhesive to position the passive component in advance, thereby preventing positioning error and the passive component can not electrically connect with the circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1A through FIG. 1H are schematic flow diagrams showing the process for integrating at least one passive component within a substrate according to a first embodiment of the present invention;
FIG. 2A and FIG. 2B are schematic flow diagrams showing the process for integrating at least one passive component within a substrate according to a second embodiment of the present invention; and
FIG. 3 is a cross-section view showing a substrate integrated with at least one passive component according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to make the illustration of the present invention more explicit and complete, the following description is stated with reference to FIG. 1A through FIG. 3 .
Refer to FIG. 1A through FIG. 1H . FIG. 1A through FIG. 1H are schematic flow diagrams showing the process for integrating at least one passive component within a substrate according to a first embodiment of the present invention. Refer to FIG. 1A again. First, a circuit layer 110 is provided. The circuit layer 110 includes an intermediate layer 111 and an electrically conductive layer 112 . The intermediate layer 111 is made of dielectric material. The electrically conductive layer 112 is formed at both sides of the intermediate layer 111 and made of metal material, such as Cu, Ni or Au.
Refer to FIG. 1B again. Next, at least one positioning blind hole 113 is formed in the circuit layer 110 . The positioning blind hole 113 may be formed by a method such as laser drilling or mechanical drilling. The positioning blind hole 113 is drilled from one side of the circuit layer 110 of the electrically conductive layer 112 , and another side of the electrically conductive layer 112 is not drilled, thereby forming the blind hole.
Refer to FIG. 1C again. Next, the electrically conductive layer 112 of the circuit layer 110 is patterned to form a circuit 114 . The electrically conductive layer 112 is patterned by a method such as photolithography etching or laser etching. The circuit 114 includes at least one contact 114 a connected to the positioning blind hole 113 , thereby forming an electrical connection to at least one passive component 120 .
Refer to FIG. 1D again. Next, a conductive material 115 is formed in (such as filled in) the positioning blind hole 113 . The conductive material 115 is preferably adhesive, such as a conductive glue or a melted metal.
Refer to FIG. 1E again. Next, the passive component 120 is disposed and positioned to the positioning blind hole 113 of the circuit layer 110 . Since the positioning blind hole 113 has the conductive material 115 therein, and the contact 114 a of the circuit 114 is connected to the positioning blind hole 113 , the passive component 120 can be electrically connected to the circuit layer 110 via the conductive material 115 in the positioning blind hole 113 . Further, since the conductive material 115 is preferably adhesive, the passive component 120 can be bonded and positioned to the circuit layer 110 . For example, when the conductive material 115 is the conductive glue, the conductive material 115 is filled into the positioning blind hole 113 to bond and position the passive component 120 to the circuit layer 110 . When the conductive material 115 is metal material, the conductive material 115 is heated previously to a melted state, and then filled into the positioning blind hole 113 . The passive component 120 is bonded and positioned to the circuit layer 110 before the melted metal is solidified.
Refer to FIG. 1F again. Next, a core layer 130 , the passive component 120 and two circuit layers 110 are laminated as one substrate 100 , wherein a dielectric layer 140 is formed between the core layer 130 and the circuit layer 110 . After the laminating step, the circuit layers 110 are formed on both sides of the core layer 130 , and the passive component 120 is embedded in the core layer 130 . The core layer 130 is made of dielectric material, such as Bismaleimide Triazine (BT), epoxy resin, ceramics or organic glass fiber. The core layer 130 includes at least one through hole 131 to embed the passive component 120 . The through hole 131 may be formed by a method such as laser drilling or mechanical drilling. Therefore, the passive component 120 of the present embodiment can be positioned and bonded on the circuit layer 110 previously by the positioning blind hole 113 , and be electrically connected to the circuit 114 on the circuit layer 110 via the conductive material 115 within the positioning blind hole 113 , thereby preventing the passive component 120 from positioning error, wherein the conductive material 115 is preferably adhesive to previously bond the passive component 120 on the circuit layer 110 .
It is worth mentioning that the circuit 114 on the circuit layer 110 may be formed after the laminating step. Namely, the electrically conductive layer 112 is patterned to form the circuit 114 of the circuit layer 110 after the laminating step.
Refer to FIG. 1G again. Next, after the laminating step, at least one conductive through hole 150 is formed in the substrate 100 by a method such as laser drilling or mechanical drilling. A metal layer 151 (such as Cu layer) is formed on the surface of the conductive through hole 150 to electrically connect with the circuit layers 110 on both sides of the core layer 130 , wherein the metal layer 151 is formed by a method such as electroplating.
Refer to FIG. 1H again. Then, an isolation layer 160 (such as solder mask) is used to encapsulate the surface of the substrate 100 for packaging, wherein the circuit 114 is exposed on the circuit layers 110 after encapsulating the isolation layer 160 . Further, a conductive antioxidant 170 may be formed on the circuit 114 to prevent oxidation. Therefore, the passive component 120 can be integrated into the substrate 100 of the present embodiment.
Therefore, the passive component 120 of the present embodiment can be positioned on the circuit layer 110 before the laminating step, thereby preventing positioning error and the passive component 120 can not electrically connect with the circuit 114 . Consequently, the process yield of the substrate 100 integrated with the passive component 120 can be enhanced.
Refer to FIG. 2A and FIG. 2B . FIG. 2A and FIG. 2B are schematic flow diagrams showing the process for integrating at least one passive component within a substrate according to a second embodiment of the present invention. Some reference numerals shown in the first embodiment are used in the second embodiment of the present invention. The construction shown in the second embodiment is similar to that in the first embodiment with respect to configuration and function, and thus is not stated in detail herein.
Refer again to FIG. 2A and FIG. 2B , in comparison with the first embodiment, the circuit 214 is formed on the circuit layer 210 , and then the positioning blind hole 213 is formed in the circuit layer 210 . At this time, the circuit 214 may be formed by a method such as deposition (electroplating, thermal deposition, chemical vapor deposition, physical vapor deposition or sputtering) or printing (screen printing) on the two sides of the middle layer 211 , and the electrically conductive layer 112 is not necessary to exist. Then, after forming the circuit 214 , the circuit layer 210 is drilled to form the positioning blind hole 213 .
Refer to FIG. 3 . FIG. 3 is a cross-section view showing a substrate integrated with at least one passive component according to a third embodiment of the present invention. Some reference numerals shown in the first embodiment are used in the third embodiment of the present invention. The construction shown in the third embodiment is similar to that in the first embodiment with respect to configuration and function, and thus is not stated in detail herein.
Refer again to FIG. 3 , in comparison with the first embodiment, the core layer 330 includes at least one blind hole 331 to embed the passive component 120 . The blind hole 331 may be formed by a method of such as laser drilling or mechanical drilling. At this time, the passive component 120 is positioned to the circuit layer 110 at one side of the core layer 330 .
Therefore, the manufacturing method for integrating the passive component within the substrate shown in the respective embodiments of the present invention can prevent positioning error of the passive component, thereby ensuring that the passive component electrically connects with the circuit of the substrate and enhancing the process yield thereof.
As is understood by a person skilled in the art, the foregoing embodiments of the present invention are strengths of the present invention rather than limiting of the present invention. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structure. | A manufacturing method for integrating a passive component within a substrate is disclosed. The manufacturing method comprises the steps of: providing a circuit layer, wherein a positioning blind hole is formed in the circuit layer; forming a conductive material in the positioning blind hole; positioning the passive component in the positioning blind hole of the circuit layer and electrically connecting the passive component to the circuit layer via the conductive material in the positioning blind hole; and laminating a core layer, the passive component, and the circuit layer as the substrate. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Patent Application No. 60/906,752 filed on Mar. 13, 2007, and is a continuation in part of U.S. application Ser. No. 12/046,586 filed on Mar. 12, 2008, now U.S. Pat. No. 7,645,936 all of which are incorporated herein by reference.
FIELD OF THE INVENTION
This invention pertains to a cover of an electrical outlet box and more particularly to a cover having an adjustable extension sleeve attached thereto.
BACKGROUND OF THE INVENTION
Daring construction, electrical outlet boxes are affixed to their support or stud prior to the wall covering (i.e. dry wall) being installed. It is generally known what thickness of dry wail is going to be installed and hence electrical outlet boxes are installed off-set from the front of the stud by that amount so as to be flush with the wall. However, if the dry wall thickness is not known or if it changes or if additional wall material (i.e. tile, sound insulation, double-layer dry wall) is subsequently added, then the box opening will no longer be flush with the wall and hence it will be difficult, if not impossible, to properly install an electrical device within the box.
Solutions to this problem are varied. U.S. Pat. No. 5,253,831 discloses a bracket that is rigidly affixed to the stud. A box is then adjustably secured to the bracket. Thus, if the wall material is greater or less than expected, the entire box can be adjusted accordingly. Unfortunately, if the code specifies that all wiring to/from the box be contained in conduit, this would mean that the conduit would also have to move along with the box which is not always possible.
U.S. Pat. No. 4,927,039 discloses a removable attachment that abuts the open perimeter of the box. A first (cut-out) wall covering is applied over the box before the attachment is secured against the open front face of the box. Then a second wall covering is installed. Thus, this attachment is configured to accommodate both, wall thicknesses, but such thicknesses must be known beforehand so that the proper sized attachment can be ordered. If there is any subsequent change, this attachment cannot be subsequently altered.
A further variation is shown in U.S. Pat. No. 2,378,861 and U.S. Pat. No. 4,634,015. In both of these cases, an extension sleeve is mounted to either the box itself or to the box's cover. The extension sleeve is threadably mounted such that it can be adjusted as needed even after the wall material is installed. In both cases, however, the user must make the adjustments from inside the box which exposes the installer to the oftentimes live wires contained therein. Also, in both cases, long screws are needed as they must be at least as long as the adjustment range of the extension sleeve. Such screws also project well into the box and can interfere with the box's wiring. Further, in both cases, the ground path from the electric device to the box passes through the screw; hence if the screw is loose or the mating threads are not properly sized, grounding issues can surface. Finally, in both cases, the screw is used to position the extension sleeve and hence the extension sleeve can never be rigidly locked into any one position.
It is thus an object of this invention to provide a cover that is inexpensive to manufacture and yet is infinitely adjustable. A further object of this invention is to provide a cover whose adjustable extension sleeve provides a solid ground path for the electric device and which can be easily locked or fixed at a selected position as desired. Still a further object of this invention is to eliminate the need for long screws that can interfere with the box's wiring and to also eliminate the need for the installer to make adjustments from within the box. Yet another object of this invention is to provide a means where adjustments to the box can be made without adjusting the position of the box itself. It is a further object of this invention to provide a means of making adjustments even if the wall thickness varies or if later a new wall covering is applied. These and other objects and advantages of this invention will be come apparent upon further investigation and review.
SUMMARY OF THE INVENTION
This invention pertains to an adjustable cover that is mounted to an electrical outlet box. The cover incorporates a mounting plate that extends over a portion of the electrical outlet box. This cover includes a collar that surrounds an opening with this collar having a distal end spaced from the mounting plate. An extension sleeve fits within this collar and moves with respect thereto. Adjacent the opening is at least one fastener, this fastener being movable between a locking position and an unlocking position. The fastener operates at least one locking device to selectively cause such device to engage or disengage the extension sleeve in order to selectively lock or unlock the extension sleeve with respect to the mounting plate. The at least one locking device includes a pair of L-shaped wedges.
Further provided is an adjustable cover for an electrical outlet box including a mounting plate, an extension sleeve and two locking devices. The mounting plate has an inner rim, the inner rim defines an opening, the inner rim includes two opposing tabs on opposite sides of the inner rim and protruding into the opening. The extension sleeve extends adjacent to the inner rim and the opening, the extension sleeve extending generally perpendicular to the mounting plate, the extension sleeve being freely movable within the inner rim. Two locking devices, each device including a fastener and a pair of L-shaped wedges, each fastener extending through each of the pair of L-shaped wedges and one of the two tabs. The locking devices configured to selectively engage and disengage the extension sleeve so as to selectively lock and unlock the extension sleeve with respect to the mounting plate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view of the box cover of the present invention.
FIG. 2 is a bottom view of the cover of FIG. 1 .
FIG. 3 is a top view of the box cover of FIG. 1 .
FIG. 4 is bottom perspective view of the extension sleeve of the present invention.
FIG. 5 is a top perspective view of the mounting plate of the present invention.
FIG. 6 is a cross-sectional view of the mounting plate of FIG. 5 along A-A.
FIG. 7 is a side perspective view of the mounting plate of FIG. 1 .
FIG. 8 is an enlarged side perspective view of a portion of the mounting plate and wedge of FIG. 7 .
FIG. 9 is a top perspective view of wedge of FIG. 1 .
FIG. 10 is a side planar view of wedge of FIG. 9 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1-10 there is shown an adjustable device cover 10 of the present invention including a mounting plate 12 , an extension sleeve 14 and a locking device 16 . This assembly includes a generally rectangular base or mounting plate 12 that is used to secure device cover 10 to an electrical outlet box (not shown) and preferably a two or more gang box such as a 4 inch square or a 4 11/16 inch square box. A series of slots or apertures 18 are spaced along the perimeter of plate 12 through which one or more fasteners would extend so as to mount cover 10 to the outlet box in the convention fashion. These slots 18 are preferably arranged so that mounting plate 12 can be secured to the box in a variety of different orientations.
The center of cover 10 contains a large opening 20 that permits access through cover 10 to the interior of the electrical outlet box. Surrounding and generally defining opening 20 is collar 22 which projects away from and generally perpendicular to mounting plate 12 . FIGS. 1 , 5 and 6 show the upper distal end 24 of collar 22 is generally rounded, being curved towards opening 20 . FIGS. 6 and 7 show tab 26 is recessed or inset from the collar 22 . The collar 22 includes at least one inwardly facing tab 26 . The tab 26 projects inwardly toward the opening 20 . FIGS. 1-3 and 5 show two opposing tabs 26 . The tabs 26 include aperture 56 used for locking the extension sleeve 14 to the mounting plate 12 . Tab 26 includes an interior threaded portion 30 which mates with the exterior threading of fastener 32 to lock the fastener in place.
FIGS. 1-3 show slidably positioned within collar 22 is extension sleeve 14 . Extension sleeve 14 is generally an open box-like structure having sidewalls 34 corresponding with opening 16 . The depth of sidewalls 34 is approximately the amount of adjustment provided by cover 10 , hence such depth can be varied by the manufacturer as needed. Extension sleeve 14 contains device mounting tabs 38 which are used to secure an electric device (not shown) to cover 10 . The sidewall(s) 34 which would run adjacent to tab(s) 26 of the collar 22 include a concaved portion or a channel 36 that closely conforms to tab 26 and which protrudes into the opening 20 . The tab 26 travels through the channel 36 until the preferred position is obtained and the extension sleeve 14 is secured in position accordingly. Also, if desired, extension sleeve 14 can be configured with upper stops and/or lower stops 28 that prevent extension sleeve 14 from sliding out of mounting plate 12 . Such stops 28 can consist primarily of small projections that engage distal end 24 of collar 22 but cannot pass through opening 20 .
FIG. 3 shows the opposite corners 40 of extension sleeve 14 are beveled or angled inwardly into opening 20 . While this bevel is shown as being slightly curved into the opening 20 , other configurations are possible if desired such as to accommodate both the electrical device mounted to tabs 38 as well as the mounting screws passing through slots 18 . It is also possible that the four corners 40 of extension sleeve 14 are regular 90 degree corners. In some cases, protruding stops are located at one or more such corners 40 which help prevent extension sleeve 14 from sliding out of collar 22 . However, these stops are not required for the operation of cover 10 .
FIG. 7 shows details of the locking device 16 which includes a fastener 32 and a pair of wedges 42 . The short fastener 32 passes through wedge apertures 44 and proceeds into the inward tab 26 through aperture 56 . These fasteners 32 are adjustable between a locking position and an unlocking position to allow for adjustment of the collar 22 along the extension sleeve 14 and securement of the collar 22 at the desired position along the extension sleeve 14 .
FIGS. 7 and 8 show the pair of wedges 42 including identical wedges 42 where one wedge 42 a is positioned on top of the other wedge 42 b . The top wedge 42 a is positioned upside down and rotated 180° from, the position of the bottom wedge 42 b as shown in FIG. 8 . This position allows wedge 42 a to seat on top of wedge 42 b and as the head 46 of the fastener 32 draws the wedges 42 a , 42 b together against the tab 26 the wedges 42 a , 42 b are forced outwardly against the wall of the channel 36 .
FIGS. 9 and 10 show wedge 42 has a generally L-shaped geometry that will flex outwardly to meet and mate with the walls of the channel 36 . Each wedge 42 includes two parallel L-shaped surfaces 60 , an upper surface 48 , a lower surface 50 , two side surfaces 52 , 54 and material therebetween. The bottom surface 50 is a planar surface. The upper surface 48 extends between the L-shaped surfaces 60 . The upper surface 48 includes two planar surfaces 48 a and 48 c which are parallel to the bottom surface 50 , Planar surface 48 a is shorter than planar surface 48 c . Shorter planar surface 48 a is spaced apart from longer planar surface 48 e . Angled surface 48 b connects planar surface 48 a to a longer planar surface 48 c . Angled surface 48 b sloped downwardly from shorter surface 48 a at angle A which is less than 90°. Angled surface 48 b similarly extends from longer planar surface 48 c upwardly toward shorter surface 48 a at angle B which is an obtuse angle greater than 90°, preferably about 135°. Wedge aperture 44 extends through longer planar surface 48 c through the wedge and bottom surface 50 . Additionally, the aperture 44 cuts through a portion of angled surface 48 b . Extending from longer planar surface 48 c is shorter angled surface 48 d , Shorter angled surface 48 d extends between long planar surface 48 c and side surface 54 . Shorter angled surface 48 d is preferably shorter than angled surface 48 b . Shorter angled surface 48 d is preferably parallel to angled surface 48 b . Side surfaces 52 and 54 extend generally perpendicularly from lower surface 50 .
FIGS. 1 , 2 , 7 and 8 show wedges 42 are sized so that while they are loosely restrained by fastener 32 in the unlocked position collar 22 is allowed to move freely about sleeve 14 . The fastener 32 extends through the wedges 42 and then through the aperture 56 of the tab 26 in the mounting plate 12 . Fastener 32 includes a head 46 at one end, a stop 58 at the other end and a threaded portion therebetween in which the wedges 42 mate with the fastener 32 . Stop 58 is larger than aperture 56 of the tab 26 such that the fastener 32 is retained within aperture 56 . Stop 58 and the head 46 prevent the fastener 32 from being removed from the collar and/or the wedges 42 . In this configuration, the wedges 42 are sandwiched between the collar 22 and fastener head 46 . Once collar 22 is properly positioned along extension sleeve 14 then subsequent tightening of fastener 32 drives the fastener 32 downward along the threading of the aperture 56 . As the head of the fastener 46 nears tab 26 the wedges 42 are being compressed therebetween, and the wedges 42 is reversibly deformed outwardly against the wail of the channel 36 . This outward expansion of the wedges 42 are forced or biased against the channel 36 to hold collar 22 in place. Such force as applied by wedges 42 will bind or lock extension sleeve 14 within collar 22 . To release the wedges 42 , one need only rotate the fastener 32 so as to allow the wedges 42 to return to their original shaped configuration.
Having described the preferred embodiments herein, it should now be appreciated that variations may be made thereto without departing from the contemplated scope of the invention. Accordingly, the preferred embodiments described herein are deemed illustrative rather than limiting, the true scope of the invention being set forth in the claims appended hereto. | This invention pertains to an adjustable cover for an electrical outlet box. The cover is configured having a generally planar mounting plate with a collar surrounding an opening through this mounting plate. An extension sleeve moves within this opening and adjacent the collar. At least one fastener is located adjacent the opening and is movable between a locked position and an unlocked position. The fastener operates a locking device that engages wedges against the extension sleeve when the fastener is in the locked position and disengages wedges against the extension sleeve when the fastener is in the unlocked position. | 7 |
CROSS REFERENCE TO RELATED PATENT APPLICATIONS
This application is the National Phase Application under 35 USC §371 of International Application No. PCT/EP2010/056959, filed May 20, 2010, which claims priority to German Patent Application No. 10 2009 026 511.2, filed May 27, 2009.
BACKGROUND
A. Technical Field
The present invention relates to a microgyroscope for determining rotational motions about at least one of three perpendicular spatial axes x, y, and/or z, having a substrate on which multiple masses which oscillate parallel to the plane of the substrate in an x-y plane are situated, some of the oscillating masses being attached to the substrate by means of springs and anchorings, having drive elements for maintaining oscillating vibrations of the masses which are subjected to Coriolis forces when the substrate rotates about any given spatial axis, and having sensor elements for detecting the deflections of the masses due to the Coriolis forces generated.
Microgyroscopes are generally used for determining a rotational motion about an axis in an orthogonal x-y-z coordinate system. Therefore, three such microgyroscopes are necessary to be able to determine rotational motions of the system about each of the three axes. This entails high expense, and complicated control and evaluation of the data.
B. Background of the Invention
A triaxial microelectromechanical (MEMS) gyroscope is known from TW 286201 BB. Masses which are situated on a central anchoring are set in oscillating rotational motion. The masses are arranged on a substrate, and when there is a torque about the x or y axis the masses are tilted about the y or x axis, respectively, due to a Coriolis force which occurs. This is made possible by an appropriate suspension of these drive masses on the substrate. When there is a torque about the z axis, partial masses are translationally deflectable by an appropriate suspension of these partial masses on the rotatably supported masses. The tilting motions as well as the translational motion may be detected by sensors, and due to their proportionality to the rotational motion of the substrate, are used as a measure of the corresponding rotation about the x, y, or z axis. However, the respective deflections are very difficult to determine.
To allow a three-dimensional gyroscope to be provided for which rotations about all three axes may be determined, in the 1996 article titled “A monolithic silicon gyroscope capable of sensing about three axes simultaneously,” D. Wood et al. proposed a gyroscope having oscillating masses annularly arranged around a central anchoring. These masses are able to undergo tilting motions as well as rotational motions as the result of Coriolis forces which occur. It is disadvantageous that it is difficult to manufacture such a sensor and to drive the moved masses. The motions of the individual components of the sensor have a mutual influence on one another, so that measurements of the motion in the x, y, or z direction of the gyroscope do not provide sufficient accuracy.
One-dimensional and two-dimensional gyroscopes are also basically known which are able to detect tilting and rotational motions of the gyroscope only about one or about two of the three spatial axes x, y, and z. Fairly simple gyroscopes of this type are adequate for many applications.
SUMMARY OF THE INVENTION
The object of the present invention is to provide microgyroscopes which are compact and which have a relatively simple design, and which have high detection accuracy with regard to one, two, or three yaw rates about the x, y, and/or z axis.
The present object is achieved by a microgyroscope having the features of claim 1 .
The microgyroscope according to the invention is a microelectromechanical system (MEMS), and is used for determining rotational motions about at least one, and in one preferred embodiment of the invention, about two or three, of three perpendicular spatial axes x, y, and z. Multiple masses which oscillate parallel to the plane of the substrate in an x-y plane are situated on a silicone [sic; silicon] substrate. At least some of these oscillating masses are attached to the substrate by means of springs and anchorings. Drive elements are used for maintaining linearly oscillating vibrations of these masses. When the substrate rotates about a predetermined spatial axis, Coriolis forces result which cause the associated masses to be deflected in a defined direction. These deflections may be detected using sensor elements.
If x or y yaw rates are to be detected, in addition to the drive direction extending parallel to the substrate, some of the oscillating masses may be deflected along the z axis perpendicular to the substrate. The masses which are also deflectable along the z axis and which are designed for detecting yaw rates about the x axis are referred to below as “x masses”; similarly, the masses which are deflectable along the z axis and which are designed for detecting rotations of the substrate about the y axis are referred to as “y masses.” In turn, others of the oscillating masses are z masses, which in addition to their drive direction in the x-y plane are deflectable perpendicular to their respective drive direction, but within the x-y plane parallel to the substrate, in order to detect a rotation of the gyroscope about the z axis.
Accordingly, if a yaw rate is present about the x axis, Coriolis force pairs act on the x masses, resulting in oscillating deflection of the x masses in phase opposition along the z axis. Yaw rates about the y axis are detected in an analogous manner, resulting in an oscillating deflection of the y masses in phase opposition along the z axis. If a yaw rate is present about the z axis, forces which are directed radially inwardly or outwardly act on the z masses. The z masses are thus forced into a corresponding radial oscillating motion. This motion, the same as the motion of the x masses and the y masses, may be detected using sensor elements. Depending on the design of the gyroscope, all of the referenced directions of motion, or only single directions of motion, are made possible. For a design as a three-dimensional gyroscope for detecting yaw rates about all three axes, the movability of the x masses in the y direction as the primary motion and in the z direction as the secondary motion, of the y masses in the x direction as the primary motion and in the z direction as the secondary motion, and of the z masses in the x and/or y direction as the primary motion and correspondingly in the y and/or x direction as the secondary motion, are made possible by a suitable suspension of the x, y, and z masses.
On the other hand, if the gyroscope is provided strictly as a z gyroscope, the secondary movability of the x masses and y masses is suppressed. The x masses and the y masses are suspended on the substrate in such a way that only their primary motion is permitted. Only the z masses have a primary motion in the x and/or y direction and a corresponding secondary motion in the y and/or x direction in order to indicate a z yaw rate.
In another embodiment of the invention, if the gyroscope is designed as a two-dimensional gyroscope which is to detect only yaw rates about the x axis and the y axis, the gyroscope either has no z masses, or the independent movability of the z masses in the x or y direction is blocked or is not evaluated.
Further options for alternative gyroscopes according to the invention result in each case by dispensing with the corresponding mass or the movability thereof in the direction which is not required. Thus, in addition to strictly z gyroscopes, strictly x or strictly y gyroscopes or x-y, x-z, or y-z gyroscopes may be implemented which have the basic design of the present invention.
When appropriately excited, the sensor elements generate an electrical signal which is proportional to the x, y, or z yaw rate of the gyroscope. The sensor elements may be plate capacitors, for example, which are situated on the substrate and the x or y or z masses, and which generate the electrical signal when the distance between them changes. In principle, vertical or horizontal capacitors or electrodes are possible as sensor elements. It is important that the change in position of the individual elements relative to one another is detectable. This is generally achieved in that a portion of the plate capacitors or capacitor electrodes are stationarily situated on the substrate, while the portion corresponding thereto is attached to the movable x, y, or z masses.
According to the invention, a central anchoring is situated on the substrate. The masses are arranged around the central anchoring, the x masses and the y masses being connected to the central anchoring, and the z masses being connected to the x masses or to the y masses. The x masses and the y masses are supported on the substrate in such a way that they are linearly and tangentially drivable about the central anchoring. When four x or y masses are used, two of the masses are drivable in the x direction as the primary motion, and the other two masses are drivable in the y direction. The direction of motion preferably extends linearly and parallel to the x or y axis; the relative phase of the individual components is such that the moving elements as a whole undergo a linear and tangential motion about the z axis.
As the result of arranging the masses around the central anchoring and connecting the masses to the central anchoring, a supporting and coupling function is achieved which makes the system much more stable against interfering effects than is the case for the prior art. On the one hand, as the result of the linear drive motion which is tangentially directed with respect to the central anchoring, an uncomplicated drive mode is provided which allows very uniform oscillation of the masses. On the other hand, the masses are supported on the central anchoring, and when appropriately coupled, also mutually influence one another in such a way that they may be driven very uniformly and without significant deviations from one another, not only individually, but also in relation to the other masses. This allows a sensor to be provided which operates very precisely. In addition, the supporting action of the central anchoring has an effect on the masses in such a way that parasitic influences, such as impacts to the sensor, do not result in measuring errors. Without the supporting action, impacts could result in an inadvertent “butterfly mode” in which the masses, similar to the beating of the wings of a butterfly, are moved out of the x-y plane, possibly even resulting in destruction of the sensor.
The design according to the invention of the oscillating masses and their primary and secondary motions allow a relatively simple structure of the microgyroscope. In particular, the secondary motions are completely unambiguous, so that the secondary motions of the masses may be uniquely associated with an x, y, or z yaw rate by the sensor elements associated with the secondary motions. The electrical signals of the sensor elements may thus be evaluated reliably and with great accuracy.
In one preferred embodiment of the invention, the x masses and/or the y masses are designed as sensor plates. The sensor plates have a flat extension in the x-y plane parallel to the substrate, and have a relatively large mass. The sensor plates are deflected in the z direction when an x yaw rate or a y yaw rate is present. In one preferred embodiment, the sensor plates remain essentially parallel to the x-y plane during the deflection. Only the distance from the plane of the substrate changes during the deflection in the z direction.
In one advantageous embodiment of the invention, the z masses are designed as frames. The z masses are moved, together with the x masses or the y masses, in the respective primary direction of motion of the x or y mass on which they are situated. When a z yaw rate occurs, the z masses are deflected in the x-y plane, perpendicular to the respective drive direction. As a result of the frame-like design of the z mass, the arrangement of sensor elements which define the deflection perpendicular to their primary drive direction is relatively simple. The stationary sensor elements are situated inside the frame. The change in distance of the frame from the stationary elements may be easily determined. If the gyroscope is designed as a two-dimensional gyroscope which is to detect only yaw rates in the x and y directions, the z masses may be dispensed with; i.e., the gyroscope has no z masses.
To obtain a compact design of the microgyroscope, it is advantageous when the x, y, and/or z masses have an essentially rectangular layout. These masses may thus be arranged on the substrate, offset relative to one another in the x-y plane, in such a way that on the one hand they have sufficient freedom of motion for the primary and secondary motions, and on the other hand occupy a small overall area. The unused free space inside the microgyroscope may thus be kept very small. The microgyroscope as a whole is thus very compact.
To obtain stable mounting of the x masses and y masses, fixing anchors and drive springs are provided on the substrate. The x masses and y masses are fastened to the fixing anchor via the drive springs. The x masses and y masses are thus situated at a predetermined distance from the substrate in the x-y plane. The primary motion of the x masses occurs in phase opposition in the y direction. The secondary motion occurs in phase opposition in the z direction, by means of which an x yaw rate is detected. The drive springs of the x masses are therefore preferably designed in such a way that they have a controllable stiffness or flexibility in the y direction and in the z direction, but are barely flexible in the x direction. The resistance of the drive springs to a deflection of the x masses in the primary and secondary directions may be set as desired.
Similarly, the drive springs of the y masses are designed in such a way that they have a controllable stiffness or flexibility in the x and z directions, but are barely flexible in the y direction. The gyroscope is able to detect y yaw rates in this way. The primary direction of motion of the y masses occurs in phase opposition in the x direction, and the secondary motion of the y masses occurs in phase opposition in the z direction. For the drive as well as for the yaw rate detection, the drive springs for the y masses thus have a relatively soft design and offer little resistance. On the other hand, in the y direction the position of the y masses should be relatively unchangeable. Therefore, the drive springs in this direction have a stiff design.
If the microgyroscope is to be designed strictly as a z gyroscope, for example, it is advantageous when the x masses and y masses have no secondary movability. The drive springs for the x masses are then designed in such a way that they have controllable flexibility in the y direction, and are barely flexible in the z and x directions. Thus, the gyroscope is not able to detect x yaw rates. In order to not detect y yaw rates as well, it is advantageous when the drive springs for the y masses are designed in such a way that they have controllable flexibility in the x direction, and are barely flexible in the y and z directions.
To obtain a stable support of the x masses and y masses on the substrate, it is preferably provided that the x masses and y masses are each retained by an outer drive spring and an inner drive spring. The outer drive spring faces the edge of the microgyroscope, while the inner drive spring faces the adjacent mass. The resonance frequencies of the drive modes and the x or y yaw rate detection modes may be set by virtue of the shape and width of the drive springs.
If the gyroscope is to detect x or y yaw rates, it is advantageous when the outer drive springs and the inner drive springs are situated on the x or y mass with controllable flexibility in the z direction. The deflection of the x or y mass in the z direction as a secondary motion is assisted in this way.
If only z yaw rates are to be detected by the gyroscope, it is advantageous when the outer drive springs and inner drive springs are situated on the x or y mass so as to be barely flexible in the z direction. As a result of the stiff arrangement, the x masses and y masses largely remain in the x-y plane and are not deflected.
In one advantageous embodiment of the invention, when the outer drive spring and the inner drive spring have different lengths, this may be advantageous in order to compensate for inclined tilting axes in the detection of the x yaw rates or the y yaw rates. In this manner, the x or y masses which are deflected along the z axis in the course of the detection of an x or y yaw rate remain oriented essentially parallel to the x-y plane, and thus, parallel to the substrate.
The x masses and y masses are preferably driven by means of comb electrodes. One part of the comb electrodes is stationarily attached to the substrate, while the other corresponding part of the comb electrodes is attached to the x masses and the y masses. The x masses and the y masses are attracted in alternation by applying an alternating voltage, thus producing the oscillating primary motion.
In one advantageous embodiment of the invention, the x masses are oriented and driven in the y direction, and the y masses are oriented and driven in the x direction. In particular for a rectangular layout of the x masses and the y masses, a practically square overall layout of the microgyroscope may be obtained by a 90° rotation of the y masses and a correspondingly offset mounting. This results in a very compact, small design of the microgyroscope.
When two x masses and two y masses are arranged in alternation around the central anchoring, this also results in a desirable equilibrium during the drive and detection of x or y yaw rates, in the following sense: parasitic torques which could result around the anchoring during a nonuniform deflection or a nonuniform drive of the x or y masses are thus largely neutralized. The microgyroscope is thus balanced, and the corresponding yaw rates may be determined free of interfering effects.
If the x masses and the y masses are each situated on a central spring by means of a coupling spring, there is a shared, synchronous mode of vibration of these masses in the sense of the drive motion around the central anchoring. This is the case in particular when the central spring is attached to the central anchoring and is designed to rotate around same in the x-y plane. As a result of the coupling springs, all four x or y masses may be driven synchronously and may have the same resonance frequency. This is advantageous for accurate and consistent detection of yaw rates which occur.
The central spring influences the drive resonance frequency, but generally only negligibly. The central spring primarily prevents external shock pulses, which are introduced to the sensor structure along the z axis, from easily striking the x or y masses on the substrate. The secondary task of the central spring is to synchronize the drive motions of the x or y masses via the coupling springs in such a way that the x or y masses as a whole achieve a single, shared resonance frequency at the desired drive frequency.
In one particularly advantageous embodiment, the coupling springs have an overall spiral design. A coupling spring is preferably stiff in a tangential direction in order to transmit coupling forces in this direction. However, in the radial direction the coupling spring has a soft design in order to avoid distortion forces on the x or y mass. This advantageously ensures that while being driven, the x or y mass, similarly as for the secondary motion for detecting a yaw rate, is largely free of resistance but may still be synchronously moved. If the resistances due to the coupling springs were too large, there would be concern that the x or y masses might warp, which would adversely affect the detection of yaw rates about the z axis.
In one particularly preferred embodiment of the invention, a z mass is situated on each x mass and each y mass. Thus, each x mass and each y mass has a z mass. The primary motion of the z mass, together with the x mass or the y mass, occurs in the y or x direction, respectively. Due to the occurrence of z rotation of the microgyroscope, the z masses are deflected perpendicular to the direction of their primary motion, and parallel to the substrate. If the primary motion of the z mass is in the x direction, the z mass is deflected in the y direction. If the z mass is situated on an x mass whose primary motion occurs in the y direction, the Coriolis force, which refers to a z yaw rate, deflects the z mass in the x direction. Due to the drive vibration mode of the x or y masses which is synchronized by the coupling springs, and which occurs in a spiral rotational manner about the z axis, the phases of the deflections of the z masses during detection of a rotation of the gyroscope are synchronized about the z axis in such a way that they oscillate together in the x-y plane, and radially inwardly and outwardly with respect to the z axis.
To obtain appropriate elasticity for the deflection of the z masses in the secondary motion which is relevant for detecting a z yaw rate, but to still firmly connect the z mass to the x or y mass in the primary direction, springs are provided, which via a connecting bar projection are essentially centrally connected to the x or y mass. This prevents the springs from resting directly on the x mass or the y mass, which is advantageous for decoupling the z yaw rate detection from the primary motion. Such an attachment of the z mass to the x or y mass is also advantageous when the microgyroscope has a different design than that claimed herein.
It is particularly advantageous when the connection of the bar projection to the x or y mass and to the fixing anchors of the x or y mass are in flush alignment with one another. Warping, which could occur due to deformations of the x or y mass, is thus kept to a particularly low level.
The secondary motion of the z masses is specified according to the invention by the fact that the springs which are associated with the x mass have controllable flexibility in the x direction, i.e., are controllably soft, and are barely flexible in the y and z directions, i.e., have an essentially stiff design. Accordingly, it is also advantageous when the springs which are associated with the y mass have controllable flexibility or softness in the y direction, and in the x and z directions are barely flexible, i.e., have an essentially stiff design. As a result, the z mass together with the x mass and the y mass is synchronously moved in the primary direction, and optionally when the x or y mass is also deflected, is moved together with the x or y mass in its secondary direction. On the other hand, when a z yaw rate occurs, the z mass ceases its shared motion with the x or y mass, and yields in the x or y direction, depending on the direction in which the primary motion occurred.
If a gyroscope according to the invention is designed as a z gyroscope in order to detect only z yaw rates, the drive springs of the x masses are preferably designed in such a way that they have controllable flexibility in the y direction, and are barely flexible in the z and x directions. The drive springs of the y masses are designed in such a way that they have controllable flexibility in the x direction, and are barely flexible in the y and z directions. The connecting springs associated with the x masses have controllable flexibility in the x direction and are barely flexible in the y and z directions, and the connecting springs associated with the y masses have controllable flexibility in the y direction and are barely flexible in the x and z directions. As a result, the x masses and the y masses are not able to deflect in response to the Coriolis force which occurs due to yaw rates about the x or y axis, since they are supported relatively rigidly with respect to forces in the respective direction. Only the z mass is deflected and is able to respond to a z yaw rate of the gyroscope via a secondary motion in the x or y direction within the x-y plane. The sensor elements associated with the z mass detect this deflection.
If the gyroscope is designed as a three-dimensional gyroscope in order to detect yaw rates about the x, y, and z axes, the drive springs of the x masses are designed in such a way that they have controllable flexibility in the y and z directions, but are barely flexible in the x direction. The drive springs of the y masses are designed in such a way that they have controllable flexibility in the x and z directions, and are barely flexible in the y direction. The connecting springs associated with the x masses have controllable flexibility in the x direction, and are barely flexible in the y and z directions. The connecting springs associated with the y masses have controllable flexibility in the y direction, and are barely flexible in the x and z directions. All of the x, y, and z masses may thus be moved in their secondary directions as the result of a Coriolis force which occurs. The motions are detected by associated sensor elements.
If a gyroscope according to the invention is designed as a two-dimensional gyroscope in order to detect yaw rates about the x axis and the y axis, the movabilities of the x masses and the y masses are provided in the same way as for the three-dimensional gyroscope. In contrast, either the movability of the z mass in the x-y plane is blocked transverse to the primary motion, or the z masses are completely dispensed with in the corresponding gyroscope. The gyroscope thus has a simpler design, since the z masses as well as the associated springs are not necessary.
One particularly advantageous design of a three-dimensional gyroscope according to the invention is described below:
The x or y masses are set in drive motion mode by means of the drive combs. The x and y masses oscillate synchronously in the drive combs at the frequency of the drive voltage, in a tangential direction with respect to the circle described by the coupling springs. In the absence of the coupling springs, it would be possible for all four x or y masses to move independently of one another. Although excitation is provided by the same drive voltage, as a result of unavoidable production tolerances in the springs the drive resonance frequencies of the four masses would be slightly different from one another, which would necessarily result in different excitation amplitudes and slightly shifted phases of the drive motion. Due to the presence of the coupling springs, a single, shared drive resonance frequency is achieved in which all masses oscillate in phase and at the same amplitude.
If a yaw rate Ω is present about the x axis, Coriolis forces which are proportional to the cross product v x Ω, where v represents the speed of the particular mass, act on the x masses. These forces result in deflections, oscillating in phase opposition, of the plates which form the x masses, along the z axis. The plates, together with conductive surfaces located therebeneath which stationarily rest on the silicon substrate, form plate capacitors, by means of which the detection motion is converted to an electrical signal.
Yaw rates about the y axis are detected in a similar manner, resulting in deflection, oscillating in phase opposition, of the plates which form the y masses.
If a yaw rate is present about the z axis, forces which are directed radially inwardly/outwardly act on the z masses. The frames are then forced into the motion form of the z detection mode. The vertical surfaces of the recesses in the z masses form the moving halves of plate capacitors, whose stationary halves are located within the recesses.
In the absence of central springs, the gyroscope would have parasitic natural oscillations in which the plates, connected by the coupling springs, synchronously move up and down along the z axis. It would thus be difficult to prevent the sensor structure from striking the substrate under the effect of an impact along the z axis. The presence of the central springs completely eliminates this natural oscillation mode.
As a result of the spiral shape of the coupling springs, coupling forces are transmitted essentially only in a tangential direction with respect to the central, circular coupling spring. In particular, these springs are extremely soft in the radial direction. Together with the fact that their starting point is located at the inner drive spring, distortion forces which would act radially inwardly on the plates in the drive motion are thus largely avoided. Otherwise, such distortions could subsequently be transmitted to the springs which retain the z mass inside the x or y masses, thus adversely affecting the signal for detecting z yaw rates.
The springs which connect the z masses to the x or y masses rest on a bar which centrally establishes the connection to the x or y masses. This measure provides further protection of the connecting springs from buckling, and from the associated interferences in the detection of z yaw rates.
One particularly advantageous design of a two-dimensional gyroscope for detecting yaw rates about the x and y axes according to the invention is described below:
The sensor plates, i.e., the x masses and the y masses, are set in drive motion mode by the drive combs. The sensor plates oscillate in these drive combs at the frequency of the drive voltage in a tangential direction with respect to the circle described by the coupling springs. In the absence of coupling springs, it would be possible for all four plates to move independently of one another. Although excitation is provided by the same drive voltage, as a result of unavoidable production tolerances in the springs the drive resonance frequencies of the four plates would be slightly different from one another, which would necessarily result in different excitation amplitudes and slightly shifted phases of the drive motion. Due to the presence of the coupling springs, a single, shared drive resonance frequency is achieved in which all plates oscillate in phase and at the same amplitude. If a yaw rate Ω is present about the x axis, Coriolis forces which are proportional to the cross product v x Ω, where v represents the speed of the particular plate, act on the plates. These forces result in deflection, oscillating in phase opposition, of the upper left plate and the lower right plate along the z axis. The plates, together with conductive surfaces located therebeneath which stationarily rest on the silicon substrate, form plate capacitors, by means of which the detection motion is converted to an electrical signal.
Yaw rates about the y axis are detected in a similar manner, resulting in deflection, oscillating in phase opposition, of the lower left plate and the upper right plate.
In the absence of the advantageous central springs, the resonance of the “butterfly” mode, in which the plates, connected by the coupling springs, move up and down along the z axis would be at very low frequencies, approximately 5 kHz. It would thus be difficult to prevent the sensor structure from striking the substrate under the effect of an impact along the z axis. The presence of the central springs completely eliminates this mode. As a result of the spiral shape of the coupling springs, coupling forces are transmitted essentially only in a tangential direction with respect to the central, circular coupling spring. In particular, these springs are extremely soft in the radial direction.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages of the present invention are described in the following exemplary embodiments.
FIG. 1 shows a top view of a three-dimensional microgyroscope according to the invention,
FIG. 2 shows the primary motion of the microgyroscope according to FIG. 1 ,
FIG. 3 shows the detection of an x yaw rate of the gyroscope according to FIG. 1 ,
FIG. 4 shows the detection of a y yaw rate of the gyroscope according to FIG. 1 ,
FIG. 5 shows the detection of a z yaw rate of the gyroscope according to FIG. 1 ,
FIG. 6 shows a top view of a z microgyroscope according to the invention,
FIG. 7 shows the primary motion of the microgyroscope according to FIG. 6 ,
FIG. 8 shows the detection of a z yaw rate of the gyroscope according to FIG. 6 ,
FIG. 9 shows a top view of the primary motion of an x-y microgyroscope according to the invention,
FIG. 10 shows the microgyroscope according to FIG. 9 with the detection of an x yaw rate, and
FIG. 11 shows the microgyroscope according to FIG. 9 with the detection of a y yaw rate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a top view of a three-dimensional microgyroscope according to the invention. Important components are linearly oscillating sensor plates 2 , which in each case have an essentially rectangular layout and are arranged around a central anchoring 3 . The sensor plates 2 x represent the x masses, while the sensor plates 2 y form the y masses. The x masses 2 x extend lengthwise in the y direction, while the y masses 2 y have a longer extension in the x direction. The x masses 2 x as well as the y masses 2 y are situated in the x-y plane above a substrate, not illustrated.
The x masses 2 x and the y masses 2 y are driven in a linearly oscillating manner in the y or x direction, respectively, by means of comb electrodes. The comb electrodes are each composed of two stationary comb sections 4 a which are situated on the substrate, and movable comb sections 4 b which are connected to the sensor plate 2 . The electrodes are attracted in alternation by applying an alternating voltage, causing the sensor plates 2 to move back and forth in an oscillating manner.
To be movably supported in the respective direction, each sensor plate 2 is attached to two fixing anchors 5 by means of drive springs 6 a and 6 b . Outer drive springs 6 a and inner drive springs 6 b are provided. In each case the outer drive springs 6 a are situated at the outer periphery of the structure, while the inner drive springs 6 b are situated facing the adjacent sensor plate 2 . The outer drive spring 6 a and the inner drive spring 6 b may have different designs. This may be advantageous for some designs of the gyroscope according to the invention in order to allow control of the position of the tilting axes of the x masses 2 x in the x yaw rate detection motion and of the y masses 2 y in the y yaw rate detection motion (see FIGS. 3 and 4 ). If it is ensured by the design of the gyroscope that the sensor plates 2 may be driven within the x-y plane and at the same time deflected in the z direction, it is not necessary for the inner and the outer drive springs 6 a , 6 b to have different designs. In the advantageous embodiment of the invention illustrated, the fixing anchor 5 is situated approximately in the middle between the outer and the inner drive springs 6 a , 6 b.
The x masses 2 x and the y masses 2 y are point symmetrical with respect to the central anchoring 3 . The x masses 2 x have a design that is comparable to the y masses 2 y . However, the x masses and y masses are arranged on the substrate in a 90° rotation relative to one another. To ensure synchronous vibration of the sensor plates 2 , the sensor plates are connected to one another in each case via a coupling spring 7 and a circular central spring 8 which is attached via spokes to the central anchoring 3 . The coupling springs 7 have a stiff design in the drive direction of their associated sensor plate 2 , but have a soft design in the radial direction with respect to the z axis. As a result of the coupling to the central spring 8 , during the primary motion all four sensor plates 2 are driven at the same frequency and are able to vibrate. The dynamic behavior of the gyroscope is significantly improved in this manner.
z masses 9 are situated within the sensor plates 2 . The z masses 9 are designed as grid frames. The grid rods may be used as movable electrodes of plate capacitors whose stationary counterparts are stationarily mounted on the substrate, so that when a yaw rate is present about the z axis the secondary motion may be detected by means of an appropriate electrical signal.
The z mass 9 is attached to a bar 11 by means of four connecting springs 10 . The bar 11 is centrally situated via a connection 12 to the sensor plate 2 . The z mass 9 is retained by the connecting springs 10 , which are stiff in the z direction and in the drive direction of the respective sensor plate 2 , while they are soft at right angles to the drive direction of the respective sensor plate 2 within the x-y plane. Under the effect of the Coriolis forces which occur when a yaw rate is present about the z axis, the z mass 9 is thus able to yield at right angles to the drive direction, but within the x-y plane. This secondary motion may be detected using the plate capacitors.
Typical motions of the individual components of the gyroscope are illustrated in the following figures. The illustrations are greatly exaggerated to aid in identification of features. Of course, the actual deflections are much smaller. For better clarity, reference numerals, which are representative of identical components by way of example, are not shown in every figure.
FIG. 2 illustrates the drive motions of the sensor plates 2 . The x masses 2 x move in a linearly oscillating manner, parallel to the y axis and point symmetrically with respect to the central anchoring 3 . The y masses 2 y are arranged in a 90° rotation relative to the x masses 2 x . The directions of motion of the y masses are parallel to the x axis, and are likewise point symmetrical with respect to the central anchoring 3 . The inner and the outer anchoring springs 6 a , 6 b are designed in such a way that they permit this drive motion without great resistance. Thus, the drive springs 6 a and 6 b for the x masses 2 x are soft in the y direction, while they are stiff in the x direction. Similarly, the inner and the outer drive springs 6 a , 6 b of the y masses 2 y are soft in the x direction, and are stiff in the y direction. This ensures that the drive motions of the sensor plates 2 are linear. To synchronize the drive motions of all four sensor plates 2 , the sensor plates are connected to one another via coupling springs 7 and a central spring 8 which is attached to the central anchoring 3 . As a result of the coupling springs 7 , the four sensor plates 2 have the same natural oscillation frequency with respect to the drive motion. The coupling springs 7 are attached to the inner drive springs 6 b , thus largely preventing deformation of the sensor plates 2 . The central spring 8 together with its spokes is moved in a rotating oscillating manner about the central anchoring 3 due to the drive motions of the sensor plates 2 . In addition to the synchronization of the sensor plates 2 , the coupling springs 7 and the central spring 8 ensure stable support of the sensor plates 2 on the substrate.
FIG. 3 shows a perspective illustration of the deflection of the x masses 2 x for detecting a rotational motion of the gyroscope about the x axis. The x masses 2 x are deflected in the z direction as a response to Coriolis forces which occur at right angles to the primary direction of motion and to the rotational axis. For this purpose, the outer and the inner drive springs 6 a and 6 b are designed to be relatively soft in the z direction, so that they yield under the effect of a corresponding Coriolis force pair which acts on the x masses 2 x , and the x masses 2 x are moved in opposite directions in the z direction, out of the x-y plane. The secondary motion of the x mass 2 x may be detected using capacitor plates, which are formed by the top side of the substrate and the bottom side of the x masses 2 x . The secondary motion causes the distance between the capacitor plates to change, thus generating an electrical signal which indicates the x yaw rate of the gyroscope. The y masses 2 y remain in the x-y plane when there is an x yaw rate of the gyroscope, since a yaw rate about the x axis does not generate Coriolis forces for a primary motion in the x direction.
FIG. 4 shows a perspective illustration of the deflection of the y masses 2 y when a y yaw rate occurs. The y masses 2 y , which have their primary motion in the x direction, are moved out of the x-y plane in their secondary motion as a response to a y yaw rate in the z direction. The inner and the outer drive springs 6 a and 6 b are accordingly designed in such a way that they permit the primary motion as well as the secondary motion of the y mass 2 y due to their smaller spring constant in these directions. The secondary motion may once again be detected using plate capacitors, the same as for the x masses 2 x . Analogously to the behavior of the y masses, the motion state of the x masses 2 x does not change when a y yaw rate occurs, and instead is completed in the x-y plane unchanged.
FIG. 5 illustrates the detection of a z yaw rate of the gyroscope. Whereas the z masses 9 are moved in an essentially fixed manner with their associated x masses 2 x or y masses 2 y during the detection of an x yaw rate and/or a y yaw rate and in the primary motion, they undergo an independent motion when a z yaw rate occurs. On account of their connecting springs 10 , the z masses 9 are able to yield within the x-y plane, at right angles to the drive direction, when a corresponding Coriolis force occurs due to a yaw rate about the z axis. The z mass 9 moves within a cutout in the x mass 2 x or the y mass 2 y . The apparent overlapping of the z masses 9 with the x masses 2 x or y masses 2 y in FIG. 5 is an artifact of the simulation program used to create the image, which illustrates the computed deflections in an exaggerated manner for improved visibility. Of course, this does not actually occur, since the z masses 9 are located in the same plane as the x masses 2 x and the y masses 2 y . The secondary motion of the z mass 9 is detected by vertical plate electrodes or by comb electrodes. The distance of the grid structure of the z mass 9 from elements of the sensor element which are stationarily mounted on the substrate is capacitively determined and converted to a corresponding electrical signal.
The individual yaw rates of the microgyroscope according to the invention are unambiguously determinable as a result of the unique association of specific components with rotations about the respective axis. The x masses 2 x, y masses 2 y , and z masses 9 have secondary motions which are independent of one another. The corresponding yaw rate may thus be unambiguously determined, and measured using electrical signals from corresponding sensor elements.
FIG. 6 , in another example of a gyroscope according to the invention, shows a top view of a z microgyroscope. Reference is made to the analogous design from FIG. 1 . To avoid repetition, essentially only the differences are described below.
To allow a z yaw rate to be detected with accuracy and sensitivity, compared to the three-dimensional gyroscope the z mass 9 is larger in relation to the x or y mass 2 x , 2 y which accommodates it. The x masses and the y masses 2 x , 2 y do not respond to x or y yaw rates by undergoing deflection, and their mass therefore cannot be reduced. The connecting springs 10 are situated directly on the x or y mass 2 x , 2 y . A bar 11 and a bar projection 12 may be provided, but are not required, since warping due to distortion of the x or y mass 2 x , 2 y is not expected since there are no deflections in the z direction. The outer and the inner drive springs 6 a , 6 b , the same as for the three-dimensional gyroscope, have controlled flexibility in the drive direction within the x-y plane. However, they are stiff with regard to a deflection of the x or y mass 2 x , 2 y in the z direction. Accordingly, in addition to an altered spring cross section, the arrangement of the drive springs 6 a , 6 b on the x or y mass 2 x , 2 y is more direct. In addition, the x or y mass 2 x , 2 y does not represent a sensor plate which cooperates with sensor plates on the substrate 1 , since a deflection in the z direction does not occur.
FIG. 7 shows the primary motion of the z microgyroscope according to FIG. 6 . The same as in FIG. 2 and its associated description, the x masses 2 x are driven in the y direction, and the y masses 2 y are driven in the x direction, in an oscillating manner.
FIG. 8 illustrates the detection of a z yaw rate of the z gyroscope according to FIG. 6 . This is analogous to FIG. 5 and the associated description of the operating principle. The z masses 9 are deflected in the x or the y direction when a Coriolis force occurs due to a z rotation of the substrate 1 . When a yaw rate about the z axis is present, forces which are directly radially inwardly/outwardly act on the z masses 9 , as also illustrated in FIG. 5 . These z masses 9 are then forced into the motion form of the detection mode. Vertical surfaces of the recesses in the z masses 9 form the moving halves of plate capacitors, whose stationary halves are located within the recesses and are not illustrated.
The same as for the three-dimensional gyroscope, external impacts deflect the drive frames or detection frames in such a way that the changes in capacitance at the plate capacitors situated in and around the detection frames cancel out one another. External shocks to the detection electronics system are thus reliably prevented from indicating an erroneous yaw rate signal.
FIG. 9 illustrates a top view of the primary motion of a two-dimensional x-y microgyroscope according to the invention. The gyroscope essentially corresponds to the gyroscope in FIGS. 1 through 4 . The only difference is that the present x-y gyroscope has no z mass 9 together with its connecting springs 10 , bar 11 , and bar projection 12 . Therefore, full reference is made to the description for FIGS. 1 through 4 , except for the description of the z mass and the corresponding detection of a z yaw rate. The primary motion of the x masses 2 x and of the y masses 2 y once again occurs in a tangential direction around the central anchoring 3 . The x masses 2 x and the y masses 2 y are connected to one another via a coupling spring 7 and a central spring 8 for synchronization of their motions, and are connected to the central anchoring 3 for retention on the substrate. The x masses 2 x and the y masses 2 y are driven in an oscillating manner, rotating in the same direction.
FIG. 10 shows the microgyroscope according to FIG. 9 for the detection of an x yaw rate. The x masses 2 x are deflected out of their x-y plane due to a Coriolis force in the z direction. The x masses 2 x move essentially parallel to their drive position along the z axis. The resulting change in the distance of the x masses 2 x from the substrate is detected by corresponding sensor plates located on the bottom side of the x masses 2 x and on the top side of the substrate.
FIG. 11 , analogously to FIG. 10 , shows the microgyroscope according to FIG. 9 for the detection of a y yaw rate. Instead of the x masses 2 x , in the present case the y masses 2 y are deflected from their drive plane in the z direction.
The present invention is not limited to the exemplary embodiments illustrated. Thus, other shapes and other arrangements of the individual components within the scope of the claims are always possible. In particular, for a design as a three-dimensional gyroscope, it is possible for only one of the three yaw rates, for example the z yaw rate, to be evaluated. In addition, use of the gyroscope strictly as a z gyroscope is possible. Likewise, for a three-dimensional gyroscope the arrangement of the sensor plates beneath the x or y mass and on the substrate may be dispensed with in order to obtain a z gyroscope. In that case, sensor elements are associated only with the z masses. However, the embodiment of the strictly z gyroscope illustrated in the figures is more advantageous, since more cost-effective manufacture and more accurate measurement is thus possible.
LIST OF REFERENCE NUMERALS
1 Substrate
2 Sensor plate
2 x x mass
2 y y mass
3 Central anchoring
4 a Stationary comb sections
4 b Movable comb sections
5 Fixing anchors
6 a Outer drive spring
6 b Inner drive spring
7 Coupling spring
8 Central spring
9 z mass
10 Connecting spring
11 Bar
12 Central bar projection | A microgyroscope is used to determine rotational motions about at least one of three perpendicular spatial axes x, y, and z. The microgyroscope has a substrate ( 1 ) on which multiple masses ( 2 x, 2 y, 9 ) which oscillate parallel to the plane of the substrate ( 1 ) in an x-y plane are situated. Some of the oscillating masses ( 2 x, 2 y ) are attached to the substrate ( 1 ) by means of springs and anchorings. Drive elements ( 4 a, 4 b ) are used to maintain oscillating vibrations of the masses ( 2 x, 2 y, 9 ) which are subjected to Coriolis forces when the substrate ( 1 ) rotates about any given spatial axis. Sensor elements detect the deflections of the masses ( 2 x, 2 y, 9 ) due to the Coriolis forces generated. Some of the oscillating masses are x masses ( 2 x ) which are also deflectable along the z axis perpendicular to the substrate ( 1 ), by means of which they are able to detect yaw rates about the x axis, and/or some of the oscillating masses are y masses ( 2 y ) which are also deflectable along the z axis perpendicular to the substrate ( 1 ), by means of which they are able to detect yaw rates about the y axis, and/or others of the oscillating masses are z masses ( 9 ) which are also deflectable in the x-y plane, but perpendicular to their respective drive direction, by means of which they are able to detect yaw rates about the z axis. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to a connector for electrically connecting female and male terminals together, and more particularly to a connector in which wear of contact portions of the female and male terminals due to vibration is reduced.
A connector, used, for example, in the wiring of a vehicle such as an automobile, undergoes vibration developing during the travel of the vehicle, and contact portions of female and male terminals are worn by such vibration, and in some cases the electrical connection becomes defective. Therefore, there is known a conventional connector in which relative motion between female and male connector housings, fitted together, is suppressed so as to reduce wear of contact portions of female and male terminals which rub against each other (see, for example, JP-A-2002-198127 (Pages 3 to 4, FIGS. 4 and 6)).
As shown in FIGS. 5A and 5B , the connector 100 , disclosed in JP-A-2002-198127, comprises the female connector housing 102 holding the male terminals 103 , and the male connector housing 104 receiving the female terminals 101 for electrical connection to the respective male terminals 103 . The male connector housing 104 includes an inner housing 106 which holds the female terminals 101 , and is fitted into a hood portion 105 of the female connector housing 102 , and an outer housing 107 of a generally square tubular shape formed around the inner housing 106 . The male connector housing 104 is formed into an integral construction.
Limitation projections 108 are formed on an inner surface of the hood portion 15 of the female connector housing 102 , and these limitation projections 108 contact an outer surface of the inner housing 106 of the male connector housing 104 inserted and fitted in the hood portion 105 . As a result, relative motion of the female and male connector housings 102 and 104 in a direction perpendicular to the direction of fitting of these connector housings to each other is suppressed.
A lock arm 109 is formed on the outer housing 107 of the male connector housing 104 , and this lock arm 109 is retainingly engaged with an engagement projection of the female connector housing 102 . As a result, the rearward movement of the male connector housing 104 in the fitting direction is prevented, so that the fitted condition of the female and male connector housings 102 and 104 is maintained.
To reduce a load applied to the female and male terminals is effective in reducing wear of the contact portions of the female and male terminals due to vibration. However, in the connector 100 disclosed in JP-A-2002-198127, the inner housing 106 of the male connector housing 104 , holding the female terminals 101 , is formed integrally with the outer housing 107 . Therefore, when vibration is applied to the connector 100 , so that relative motion between the mutually-fitted female and male connector housings occurs, the overall weight of the male connector housing 104 is applied as a load directly to the female and male terminals 101 and 103 .
And besides, the limitation projections 108 in the connector 100 , disclosed in JP-A-2002-198127, suppress the relative motion in the direction perpendicular to the fitting direction, but is less effective in suppressing the relative motion in the fitting direction. As a result of this fact, along with the fact that the overall weight of the male connector housing 104 is applied as a load, there is a fear that wear of the female and male terminals 101 and 103 due to vibration is not sufficiently reduced.
Furthermore, when the limitation projections 108 in the connector 100 , disclosed in JP-A-2002-198127, are used for a long period of time, there is a fear that these limitation projections 108 are worn by relative motion of the female and male connector housings 102 and 104 in the fitting direction, and there is also a fear that relative motion of the female and male connector housings 102 and 104 in the direction perpendicular to the fitting direction also occurs.
SUMMARY OF THE INVENTION
This invention has been made in view of the above problems, and an object of the invention is to provide a connector in which a load, applied to female and male terminals, can be reduced, and also relative motion of mutually-fitted female and male connector housings both in a fitting direction and in a direction perpendicular to the fitting direction can be suppressed, thereby reducing wear of contact portions of the female and male terminals.
The above object has been achieved by a connector of the present invention having features recited in the following Paragraphs (1) to (4).
(1) A connector, comprising:
a female connector housing, that has a male terminal; and
a male connector housing that has a female terminal for electrical connecting to the male terminal, and that is adapted to be fitted into the female connector,
wherein the male connector housing includes:
an inner housing which has the female terminal, and which is adapted to be fitted in the female connector housing so that the female terminal is connected to the male terminal; and an outer housing which is adapted to support the inner housing so that the inner housing is movable in a first direction in which the inner housing is fitted in the female connector housing and in a second direction perpendicular to the first direction; and
wherein when the inner housing is fitted into the female connector housing, the inner housing is disposed so as to separate from the outer housing in the second direction with a first gap.
Preferably, when the inner housing is not fitted into the female connector housing, the inner housing contacts with the outer housing in the second direction or is separated from the outer housing with a second gap in the second direction. A width of the first gap is greater than that of the second gap.
(2) Preferably, a rib and a rib receiving portion are respectively formed on an outer surface of the inner housing and an inner surface of the outer housing which are opposed to each other in the second direction. When the inner housing is not fitted into the female connector housing, the rib contacts the rib reception portion, or is separated from the rib reception portion with the second gap. When the inner housing is fitted into the female connector housing, the rib is shifted away from the rib reception portion in the first direction so that the first gap is formed between the inner housing and the outer housing.
(3) Preferably, a first slanting surface is formed on the outer surface of the inner housing. A second slanting surface is formed on an inner surface of the female connector housing, and is corresponded to the first slanting surface. The first slanting surface is mated with the second slanting surface.
(4) Preferably, the connector further includes an urging unit that is interposed between the inner housing and the outer housing. When the inner housing is fitted into the female connector housing, the urging unit urges the inner housing in the first direction so that the first slanting surface of the inner housing is pressed against the second slanting surface of the female connector housing.
In the connector of the construction of the above Paragraph (1), the inner housing is supported by the outer housing in such a manner that the inner housing can move both in the first direction and in the second direction perpendicular to the first direction. Namely, the male connector housing is divided into the inner housing and the outer housing.
When the inner housing is not fitted into the female connector housing, the inner housing contacts the outer housing in the second direction perpendicular to the first direction, or is disposed in such a manner that the second gap is formed between the inner housing and the outer housing in the second direction perpendicular to the first direction. Therefore, during the operation for fitting the inner housing into the female connector housing, relative motion of the inner housing in the second direction is suppressed, and the inner housing can be smoothly fitted into the female connector housing.
When the inner housing is fitted in the female connector housing, the inner housing is disposed in such a manner that the first gap, being greater than the second gap, is formed between the inner housing and the outer housing in the second direction. Therefore, even when vibration acts on the connector, so that relative motion of the female and male connector housings occurs, the outer housing is prevented from interfering with the inner housing, and the load of the outer housing will not act on the female and male terminals. Therefore, the load, acting on the female and male terminals, is reduced, so that the load, acting on contact portions of these terminals, can be reduced.
In the connector of the construction of the above Paragraph (2), during the operation for fitting the inner housing into the female connector housing, the inner housing is moved in the first direction, and by doing so, the rib of the inner housing is displaced in the fitting direction, and is completely brought out of registry with the corresponding rib reception portion of the outer housing. As a result, a gap, corresponding to a height of the rib reception portion, is formed between the rib and the inner surface of the outer housing, and also a gap, corresponding to a height of the rib, is formed between the rib reception portion and the outer surface of the inner housing. With this simple construction, when the inner housing is not fitted in the female connector housing, the inner housing contacts the outer housing in the second direction, or is disposed in such a manner that the second gap is formed between the inner housing and the outer housing in the direction perpendicular to the fitting direction. Also, when the inner housing is fitted in the female connector housing, the inner housing is disposed in such a manner that the first gap, larger than the second gap, is formed between the inner housing and the outer housing in the second direction perpendicular to the first direction.
In the connector of the construction of the above Paragraph (3), the first slanting surface is formed on the outer surface of the inner housing, and the second slanting surface is formed on the inner surface of the female connector housing, and the first slanting surface is mated with the second slanting surface. These slanting surfaces intersect the first direction, and therefore relative motion of the inner housing and the female connector housing (which are fitted together) both in the fitting direction and in the second direction perpendicular to the fitting direction can be suppressed. Furthermore, when the mating slanting surfaces are worn, the inner housing is inserted deeper into the female connector housing, so that the first slanting surface is kept mated respectively with the second slanting surface, and therefore the relative motion can be suppressed for a long period of time.
In the connector of the construction of the above Paragraph (4), the urging unit, interposed between the inner housing and the outer housing, urges the inner housing in the first direction in such a manner that the slanting surface of the inner housing is pressed against the slanting surface of the female connector housing. With this construction, the slanting surface of the inner housing is always positively kept mated with the slanting surface of the female connector housing, and therefore relative motion of the inner housing and the female connector housing (which are fitted together) both in the first direction and in the second direction perpendicular to the first direction can be positively suppressed. A member, having spring properties, can suitably be used as the urging unit, and one example is a coil spring.
In the connector of the present invention, a load, applied to the female and male terminals, can be reduced, and also relative motion of the mutually-fitted female and male connector housings both in the first direction and in the second direction perpendicular to the first direction can be suppressed, thereby reducing wear of the contact portions of the female and male terminals.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein:
FIG. 1 is an exploded, perspective view of one preferred embodiment of a connector of the present invention;
FIG. 2 is a perspective view showing an inner housing and an outer housing of a male connector housing, with the outer housing shown as being partly broken;
FIG. 3A is a cross-sectional view of the male connector housing which is not fitted in a female connector housing, and FIG. 3B is an enlarged view of a portion surrounded by a broken line IIIb of FIG. 3A ;
FIG. 4A is a cross-sectional view of the male connector housing fitted in the female connector housing, and FIG. 4B is an enlarged view of a portion surrounded by a broken line IVb of FIG. 4A ; and
FIGS. 5A and 5B are cross-sectional views of a related connector.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
One preferred embodiment of a connector of the present invention will now be described in detail with reference to the drawings.
FIG. 1 is an exploded, perspective view of the connector of this embodiment, FIG. 2 is a perspective view showing an inner housing and an outer housing of a male connector housing, with the outer housing shown as been partly broken, FIG. 3A is a cross-sectional view of the male connector housing which is not fitted in a female connector housing, FIG. 3B is an enlarged view of a portion surrounded by a broken line IIIb of FIG. 3A , FIG. 4A is a cross-sectional view of the male connector housing fitted in the female connector housing, and FIG. 4B is an enlarged view of a portion surrounded by a broken line IVb of FIG. 4A .
As shown in FIG. 1 , the connector 1 of this embodiment includes the female connector housing 2 which holds male terminals 4 (indicated by dot-and-dash lines in FIG. 4A ), and the male connector housing 3 receiving female terminals 5 for electrical connection to the respective male terminals 4 .
The female connector housing 2 is, for example, a resin-molded part in which the male terminals 4 are insert molded, and this female connector housing 2 is fixed to an equipment, and includes a hood portion 6 of a generally rectangular tubular shape surrounding the male terminals 4 . A pair of retaining projections 7 for retaining engagement with respective retaining member formed on the outer housing of the male connector housing 3 (described later) are formed on an outer surface of the hood portion 6 .
Referring to FIG. 2 , the male connector housing 3 comprises the inner housing 20 which holds the female terminals 5 , and can be fitted in the hood portion 6 of the female connector housing 2 so that the female terminals 5 can be connected to the respective male terminals 4 held by the female connector housing 2 , and the outer housing 40 having a pair of lock arms 41 (serving as the retaining member) which are retainingly engaged with the respective engagement projections 7 of the female connector housing 2 when the inner housing 20 is fitted in the hood portion 6 of the female connector housing 2 .
The inner housing 20 is, for example, a resin-molded part, and is formed into a generally square pillar-shape, and has terminal receiving chambers 21 for respectively receiving and holding the female terminals 5 each having a wire W connected thereto. The terminal receiving chambers 21 extend through the inner housing 20 from a rear end thereof to a front end thereof in a direction of fitting of the male and female connector housings 3 and 2 to each other. Each female terminal 5 is inserted into the corresponding terminal receiving chamber 21 from a rear opening 21 a thereof.
An elastic member 8 of a waterproof nature such for example as a ring-like rubber packing is fitted on a rear end portion of the female terminal 5 to which the wire W is connected. The elastic member 8 is press-fitted into a rear end portion of the terminal receiving chamber 21 , and is fixed thereto, thereby preventing the female terminal 5 from being withdrawn from the rear opening 21 a of the terminal receiving chamber 21 .
A front holder 9 is attached to the front end portion of the inner housing 20 . The front holder 9 is held against front ends of the female terminals 5 received in the respective terminal receiving chambers 21 , thereby preventing the female terminals 5 from being withdrawn from front openings of the respective terminal receiving chambers 21 . Openings 9 a are formed in the front holder 9 , and the female terminals 5 are accessible from the exterior in the fitting direction through these openings 9 a.
An elastic member 10 of a waterproof nature such for example as a ring-like rubber packing is fitted on the front end portion of the inner housing 20 . When the inner housing 20 is fitted in the hood portion 6 of the female connector housing 2 , the elastic member 10 is held in intimate contact with an inner surface of the hood portion 6 to form a waterproof seal, and also functions as a shock absorbing material for damping vibration transmitted between the hood portion 6 and the inner housing 20 .
The outer housing 40 is, for example, a resin-molded part, and receives the inner housing 20 therein, and is formed into such a generally square tubular shape that the outer housing 40 surrounds the received inner housing 20 , with a predetermined gap formed between its surface and the outer surface of the inner housing 20 .
A pair of elastic retaining piece portions 42 are formed respectively on opposed inner side surfaces of the outer housing 40 . The elastic retaining piece portion 42 has a generally L-shape, and its distal end portion extends rearwardly in the fitting direction, and its proximal end portion is integrally connected to the inner surface of the outer housing 40 . A retaining projection 43 is formed at the distal end portion of the elastic retaining piece portion 42 , and is directed toward the inside of the outer housing 40 . A pair of engagement projections 22 for retaining engagement respectively with the pair of elastic retaining piece portions 42 are formed on and project from the outer surface of the rear end portion of the inner housing 20 .
The inner housing 20 is inserted into the outer housing 40 through a front opening 40 a of the outer housing 40 . As the inner housing 20 is inserted into the outer housing 40 , a rear end surface of each engagement projection 22 of the inner housing 20 is brought into abutting engagement with a front end surface of the retaining projection 43 of the corresponding elastic retaining piece portion 42 of the outer housing 40 , and elastically deforms the elastic retaining piece portion 42 in a manner to move the distal end portion of the elastic retaining piece portion 42 toward the inner surface of the outer housing 40 to which the proximal end portion of the elastic retaining piece portion 42 is integrally connected. When the inner housing 20 reaches a predetermined position, the elastic retaining piece portion 42 slides past the engagement projection 22 of the inner housing 20 , and is restored into its initial condition from the elastically-deformed condition, so that the retaining projection 43 is located at the front side of the engagement projection 22 . In this condition in which the inner housing 20 is thus received in the outer housing 40 , each elastic retaining piece portion 42 of the outer housing 40 is retainingly engaged at the rear end surface of its retaining projection 43 with the front end surface of the corresponding engagement projection 22 of the inner housing 20 .
Coil springs 11 (made of metal), serving as urging members, are interposed between the inner housing 20 and the outer housing 40 . The coil springs 11 are so arranged as to be expanded and contracted in a direction coinciding with the fitting direction, and these coil springs 11 resiliently urge the inner housing 20 forwardly in the fitting direction relative to the outer housing 40 . As described above, the engagement projections 22 of the inner housing 20 are retained respectively by the elastic retaining piece portions 42 of the outer housing 40 , and therefore the inner housing 20 is prevented from being withdrawn from the front opening 40 a of the outer housing 40 .
A rear cover 12 is mounted in a rear opening of the outer housing 40 to close this rear opening, and the wires W, connected respectively to the female terminals 5 held in the inner housing 20 , can be led to the exterior through the rear cover 12 .
The structure of fitting the female connector housing 2 and the male connector housing 3 together will be described with reference to FIGS. 3 and 4 .
FIG. 3A is a cross-sectional view showing the male connector housing 3 in its non-fitted condition in which the male connector housing 3 is not fitted in the female connector housing 2 . In this non-fitted condition, the inner housing 20 is resiliently urged forwardly in the fitting direction by the coil springs 11 , and is received within the outer housing 10 , with the engagement projections 22 retained by the respective elastic retaining piece portions 42 of the outer housing 40 .
A plurality of ribs 23 and a plurality of rib reception portions 44 are formed respectively on the outer surface of the inner housing 20 and the inner surface of the outer housing 40 which are opposed to each other in a direction perpendicular to the fitting direction, and each rib 23 and the corresponding rib reception portion 44 project toward each other. In order that the inner housing 20 can be smoothly inserted into the outer housing 40 , a clearance (small gap) C 1 is formed between each rib 23 and the corresponding rib reception portion 44 as shown in FIG. 3B . The inner housing 20 , received within the outer housing 40 , is contacted at the ribs 23 with the rib reception portions 44 of the outer housing 40 , or is disposed in such a manner that the clearance C 1 is formed between each rib 23 and the corresponding rib reception portion 44 . This inner housing 20 is resiliently urged by the coil spring 11 , and is supported by the outer housing 40 in such a manner that the inner housing 20 will not move relative to the outer housing 40 in a direction perpendicular to the fitting direction, and can move forward and rearward in the fitting direction.
A plurality of limitation projections 24 are formed on the outer surface of the front end portion of the inner housing 20 , and are arranged generally symmetrically with respect to a centerline (or axis) of the inner housing 20 . A front end surface 24 a of each of the limitation projections 24 is defined by a slanting surface which is slanting forwardly in the fitting direction in a manner to gradually approach the centerline of the inner housing 20 . Slanting surfaces 6 a which can be mated respectively with (or held in surface-to-surface contact with) the slanting surfaces 24 a of the limitation projections 24 of the inner housing 20 are formed on an inner surface of the opening of the hood portion 6 of the female connector housing 2 .
As the male connector housing 3 is moved to be fitted into the female connector housing 2 , the inner housing 20 of the male connector housing 3 is fitted into the hood portion 6 of the female connector housing 2 . At this time, the hood portion 6 of the female connector housing 2 enters a space between the outer surface of the inner housing 20 of the male connector housing 3 and the inner surface of the outer housing 40 thereof. Then, the slanting surfaces 24 a of the limitation projections 24 of the inner housing 20 are mated respectively with the slanting surfaces 6 a of the hood portion 6 , so that the position of the inner housing 20 relative to the female connector housing 2 is fixed.
FIG. 4A shows the male connector housing 3 fitted in the female connector housing 2 . At the time when the male connector housing 3 is completely fitted in the female connector housing 2 , the hood portion 6 of the female connector housing 2 further enters the space between the outer surface of the inner housing 20 of the male connector housing 3 and the inner surface of the outer housing 40 thereof, and the engagement projections 7 , formed on the outer surface of the hood portion 6 , are retainingly engaged with the lock arms 41 of the outer housing 40 . The inner housing 20 , fixed to the female connector housing 2 , is moved rearward in the fitting direction relative to the outer housing 40 by an amount larger than an amount of superimposing of each rib 23 and the corresponding rib reception portion 44 on each other in the fitting direction.
In this fitted condition, the inner housing 20 and the outer housing 40 are supported by the hood portion 6 of the female connector housing 2 independently of each other. And, the inner housing 20 is moved rearward in the fitting direction relative to the outer housing 40 as described above, and by doing so, each rib 23 of the inner housing 20 is displaced in the fitting direction, and is completely brought out of registry with the corresponding rib reception portion 44 . As a result, a gap C 2 , corresponding to a height of the rib reception portion 44 , is formed between the rib 23 and the inner surface of the outer housing 40 , and also a gap C 3 , corresponding to a height of the rib 23 , is formed between the rib reception portion 44 and the outer surface of the inner housing 20 as shown in FIG. 4B . Both of the gap C 2 and the gap C 3 are larger than the clearance C 1 , and therefore in this condition, a larger gap is formed between the inner housing 20 and the outer housing 40 than in the non-fitted condition of the male connector housing 3 (in which it is not fitted in the female connector housing 2 ).
Thus, the inner housing 20 , holding the female terminals 5 , is disposed out of contact with the outer housing 40 , and therefore even when vibration is applied to the connector 1 , so that relative motion of the female and male connector housings 2 and 3 occurs, the load of the outer housing 40 will not act on the male and female terminals 4 and 5 . As a result, a load, acting on the male and female terminals 4 and 5 , is reduced, thereby reducing wear of contact portions of these terminals.
And besides, the slanting surfaces 24 formed respectively on the limitation projections 24 of the inner housing 20 , as well as the slanting surfaces 6 a formed on the hood portion 6 of the female connector housing 2 , intersect the fitting direction, and therefore relative motion of the inner housing 20 and the female connector housing 2 (which are fitted together) both in the fitting direction and in a direction perpendicular to the fitting direction is suppressed. Furthermore, when the mating slanting surfaces 24 a and 6 a are worn, the inner housing 20 is inserted deeper into the female connector housing 2 , so that the slanting surfaces 24 a are kept mated with the respective slanting surfaces 6 a , and therefore the relative motion is suppressed for a long period of time.
Furthermore, the coil springs 11 resiliently urge the inner housing 20 forwardly in the fitting direction in such a manner that the slanting surfaces 24 a , formed respectively on the limitation projections 24 of the inner housing 20 , are pressed respectively against the slanting surfaces 6 a formed on the hood portion 6 of the female connector housing 2 . With this construction, the slanting surfaces 24 a , formed respectively on the limitation projections 24 of the inner housing 20 , are always positively kept mated respectively with the slanting surfaces 6 a formed on the hood portion 6 of the female connector housing 2 , and therefore relative motion of the inner housing 20 and the female connector housing 2 (which are fitted together) both in the fitting direction and in the direction perpendicular to the fitting direction is positively suppressed.
The present invention is not limited to the above embodiment, and suitable modifications, improvements and so on can be made.
The present application is based on Japan Patent Application No. 2005-106361 filed on Apr. 1, 2005, the contents of which are incorporated herein for reference. | A connector includes a female connector housing, that has a male terminal, and a male connector housing that has a female terminal for electrical connecting to the male terminal, and that is adapted to be fitted into the female connector. The male connector housing includes an inner housing which has the female terminal, and which is adapted to be fitted in the female connector housing so that the female terminal is connected to the male terminal, and an outer housing which is adapted to support the inner housing so that the inner housing is movable in a first direction in which the inner housing is fitted in the female connector housing and in a second direction perpendicular to the first direction. When the inner housing is fitted into the female connector housing, the inner housing is disposed so as to separate from the outer housing in the second direction with a first gap. | 7 |
FIELD OF THE INVENTION
This invention is concerned with the production of novel perfumes and perfumed articles containing phenylethynyl carbinol compounds.
BACKGROUND OF THE INVENTION
There is a continual search for new and inexpensive chemicals which can be utilized to modify, enhance, or otherwise improve the organoleptic properties of consumable products.
Although many acetylenic compounds are found naturally, the use of this class of compounds in perfumery has been limited. Arctander in "Perfume and Flavor Chemicals", 1969, describes the ester methyl 2-nonynoate, commonly known as "methyl heptine carbonate", as well as related acetylenes. U.S. Pat. No. 3,268,594 discloses compounds having the structure:
CH.sub.3 (CH.sub.2).sub.n C.tbd.CCH(OCH.sub.3).sub.2
which are useful as perfumery ingredients.
SUMMARY OF THE INVENTION
The present invention provides for perfume compositions having new and improved organoleptic properties.
Accordingly, it is an object of the invention to provide novel perfume compositions and perfumed articles which incorporate one or more phenylethynyl carbinol compounds into their fragrance formulas. Broadly, this invention provides for a perfume composition comprising:
a. one or more phenylethynyl carbinols having the structure: ##STR2## wherein R 1 and R 2 is the same or different lower alkyl in an amount sufficient to impart fragrance thereto; and
b. conventional perfume ingredients.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides for the production of novel perfumes and perfumed articles through the use of sufficient amounts of one or more of the phenylethynyl carbinols having the general formula presented hereinabove. Alkyl groups suitable for use in this invention perferably contain from 1 to 6 carbon atoms, most preferably from 1 to 4 carbon atoms. The alkyl groups may be straight chained or branched, cyclic or acyclic. The alkyls are perferably methyl, ethyl and isopropyl. The phenylethynyl carbinols preferably contain between 11 and about 16 carbon atoms.
Table I hereinafter illustrates some preferred compounds of Formula I which are characterized by odor notes.
______________________________________EXAMPLES OF COMPOUNDS OF FORMULA I______________________________________3-Methyl-1-phenyl-1-butyn-3-ol green, floral ##STR3##3-Methyl-1-phenyl-1-pentyn-3-ol rosey, floral muguet-like ##STR4##3-Ethyl-1-phenyl-1-pentyn-3-ol fresh, rosey ##STR5##3,4-Dimethyl-phenyl-1-pentyn-3-ol sweet, floral slightly rosey ##STR6##______________________________________
Compounds of the present invention may be prepared in accordance with known technology by reacting phenylacetylene with the appropriate ketone as illustrated in accompanying Scheme I. ##STR7## Such procedures are reported by Smissman et al., in the Journal of the American Chemical Society, Vol. 78, pp. 3395-3400 (1956) and are incorporated here by reference.
The phenylethynyl carbinols of the present invention have been found to possess distinctive green, floral, rosey, muguet, slightly balsamic odors which render them useful in fine fragrances as well as perfumed products such as soaps, detergents, deodorants, cosmetic preparations and the like.
One or more of the phenylethynyl carbinols of this invention and auxiliary perfume ingredients, for example, alcohols, aldehydes, ketones, nitriles, esters and essential oils, may be admixed so that the combined odors of the individual components produce a desired fragrance. Such perfume compositions are carefully balanced, harmonious blends of essential oils, aroma chemicals, resinoids and other extracts of natural odorous materials. Each perfume ingredient imparts its own characteristic effect to the composition. Thus, one or more of the phenylethynyl carbinols of the invention can be employed to impart novel characteristics into fragrance compositions.
Such perfume compositions may contain between about 0.001 and about 80 weight percent of any one or more of the phenylethynyl carbinols of this invention. Ordinarily, at least about 0.001 weight percent of the phenylethynyl carbinol is required to impart significant odor characteristics. Amounts of phenylethynyl compounds in the range of from about 1 to about 60 weight percent are preferred. The phenylethynyl carbinols of this invention may be formulated into concentrates containing from about 1 to about 60 weight percent of the compound in an appropriate solvent. Such concentrates are then employed to formulate products such as colognes, soaps, etc., wherein the concentration of the compounds of this invention can be in the range of from about 0.001 to 7 weight percent, depending upon the final product. For example, the concentration of the compounds of this invention will be of the order of about 0.001 to about 0.1 weight percent in detergents, and of the order of about 0.1 to about 7 weight percent in perfumes and colognes.
The phenylethynyl carbinols of this invention are useful as olfactory components of perfume compositions for detergents and soaps, space odorants and deodorants, perfumes, colognes, toilet water, bath preparations such as bath oils and bath solids, hair preparations such as lacquers, brilliantines, pomades and shampoos, cosmetic preparations such as creams, deodorants, hand lotions and sunscreens, powders such as talcs, dusting powders and face powders, and the like.
The following examples are set forth herein to illustrate the preferred method of synthesis of the compounds of this invention. In addition, examples are included which demonstrate their use in fragrance compositions. These examples are intended only to illustrate the preferred embodiments of this invention and are in no way meant to limit the scope thereof.
EXAMPLE 1
Preparation of 3-Methyl-1-phenyl-1-pentyn-3-ol
Phenylacetylene (500 g, 4.2 mol) was added to a mixture of potassium hydroxide flake (290 g) and toluene (3 L). 2-Butanone (425 g, 5.9 mol) was added over 45 minutes keeping the temperature below 30° C. with periodic cooling and the resulting mixture agitated for 20 h at room temperature. Water (1 L) was added, the toluene solution washed until neutral, the solvent evaporated, and the residue distilled to give 517 g (71% yield) of 3-methyl-1-phenyl-1-pentyn-3-ol; bp 107°-110° C./3 mm; IR (film) 3400, 1150, 1000, 920 cm -1 ; NMR (CDCl 3 ) 1.1 (3H, t), 1.6 (3H, s), 1.8 (2H, q), 2.2 (1H, s), 7.2-7.6 (5.H, m) δ; MS (m/e) 174, 156, 145, 43.
EXAMPLE 2
Preparation of 3-Methyl-1-phenyl-1-butyn-3-ol
The procedure outlined in Example 1 was followed using acetone and resulted in the isolation of 403 g (60% yield) of 3-methyl-1-phenyl-1-butyn-3-ol: bp 101° C./3 mm [mp 52°-53° C./from hexane]; IR (film) 3400, 1150, 960, 910 cm -1 ; NMR (CDCl 3 ) 1.6 (6H, s), 2.2 (1H, s), 7.2-7.5 (5H, m) δ; MS (m/e) 160, 142, 145, 43.
EXAMPLE 3
Preparation of 3-Ethyl-1-phenyl-1-pentyn-3-ol
The procedure outlined in Example 1 was followed using 3-pentanone and resulted in the isolation of 568 g (72% yield) of 3-ethyl-1-phenyl-1-pentyn-3-ol: bp 117°-118° C./3 mm; IR (film) 3400, 1310, 1130, 950 cm -1 ; NMR (CDCl 3 ) 1.1 (6H, t), 1.8 (4H, q), 2.1 (1H, s), 7.2-7.6 (5H, m) δ; MS (m/e) 188, 160, 159, 57.
EXAMPLE 4
Preparation of 3,4-Dimethyl-1-phenyl-1-pentyn-3-ol
The procedure outlined in Example 1 was followed using 3-methyl-2-butanone and resulted in the isolation of 458 g (58% yield) of 3,4-dimethyl-1-phenyl-1-pentyn-3-ol: bp 113°-115° C./3 mm; IR (film) 3400, 1100, 1060, 910 cm -1 ; NMR (CDCl 3 ) 1.1 (6H, 2d), 1.5 (3H, s) 1.6-2.0 (1H, m), 2.2 (1H, s), 7.2-7.6 (5H, m) δ; MS (m/e) 188, 160, 145, 43.
EXAMPLE 5
The following illustrates the use of the phenylethynyl carbinols in a perfume composition of the muguet type.
______________________________________BASE COMPOSITIONComponent Parts by weight______________________________________cis-3-Hexenol 1.0Tonalide 3.0Indole (10% in DEP) 3.0Citral quenched 5.0Alpha Ionone 7.0Nerolidol 8.0Citronellyl formate 8.5Geranyl acetate 9.5Citronellyl propionate 20.0Jasmin absolute B 25.0Linalool synthetic 45.0Terpineol 65.0Phenylethyl alcohol 70.0Hydroxycitronellal 100.0Benzyl alcohol 200.0 570.0______________________________________
______________________________________MODIFYING INGREDIENTS Parts by weightComponent A B C D______________________________________Geraniol 200 -- -- --Laevo citronellol 230 -- -- --3-Methyl-1-phenyl-1-pentyn-3-ol -- 430 -- --3-Ethyl-1-phenyl-1-pentyn-3-ol -- -- 400 --3,4-Dimethyl-1-phenyl-1-pentyn-3-ol -- -- -- 370Diethyl phthalate -- -- 30 60Base 570 570 570 570 1000 1000 1000 1000______________________________________
When varying amounts of the phenylethynyl carbinols (formulations B, C and D) were mixed with the base as indicated, the character of the finished products was more rounded and esthetic as evaluated in both the freshly blottered and on dry out, than compositions A with the rose alcohols normally used.
EXAMPLE 6
The following illustrates the use of several phenylethynyl carbinols in the preparation of a substitute Rose absolute.
______________________________________BASE COMPOSITIONComponent Parts by weight______________________________________Phenylacetic acid 2Rosetone 4Benzyl isoeugenol 10Oakmoss absolute 4Dimethylbenzylcarbinyl acetate 20Guaiacwood acetate 20Honey base 10Undecylenic alcohol 2Aldehyde C.sub.9 (10% in DEP) 15Aldehyde undecylenic (10% in DEP) 20Alcohol C.sub.9 2Mimosa absolute 2Oil Chamomile blue 1Methyl octine carbonate (1% in DEP) 10Penylacetaldehyde dimethyl acetal 9Costus 5Isobutylphenyl acetate 12Alpha Irisone white extra 25Oil Geranium bourbon 19Oil Ceranium Maroc selection 40Phenylethyl acetate 12Citronellyl formate 40Dibutylsulfide (1% in DEP) 4Geranyl acetate 50Phenylethyl alcohol 902-trans-6-cis-Nonadienal (5% in DEP) 2 430______________________________________
______________________________________MODIFYING INGREDIENTS Parts by weightComponent A B C D E______________________________________Geraniol ex Palmarosa 270 -- -- -- --Laevo citronellol 300 -- -- -- --3-Methyl-1-phenyl-1- -- 570 -- -- --pentyn-3-ol3-Ethyl-1-phenyl-1- -- -- 530 -- --pentyn-3-ol3,4-Dimethyl-1-phenyl-1- -- -- -- 500 --pentyn-3-ol3-Methyl-1-phenyl-1- -- -- -- -- 570butyn-3-olDiethyl phthalate -- -- 40 70 --Base 430 430 430 430 430 1000 1000 1000 1000 1000______________________________________
When the rose absolute is made up with the varying amounts of phenylethynyl carbinols as indicated above (formulations B, C, D and E), the characteristics of the finished products are more esthetic and better balanced than the one made with the rose alcohols (example A) normally used. | The invention discloses perfume compositions containing one or more phenylethynyl carbinol compounds along with conventional perfume ingredients. The phenylethynyl carbinol compounds have the formula: ##STR1## wherein R 1 and R 2 is the same or different lower alkyl. | 2 |
The Government has rights in this invention pursuant to a Government Contract.
The invention relates to an optical recording medium and information record having a radial tracking aid in the form of a masking layer, with slots therein, spaced apart from and overlying the layer in which information is recorded.
BACKGROUND OF THE INVENTION
Information may be recorded by exposing a portion of an optical recording medium to a recording light beam thereby changing the local optical properties of the exposed portion. The simplest such recording medium is a monolayer structure having a light absorptive layer overlying a substrate. Information is recorded by locally melting or ablating the light absorptive layer to change the transmission or reflectivity of the recording medium in the exposed portions.
Spong, in U.S. Pat. No. 4,097,895, issued June 27, 1978 which is entitled MULTILAYER OPTICAL RECORD and which is incorporated herein by reference, disclosed a bilayer optical recording medium which comprises a light reflective layer coated with a light absorptive layer. Bell, in U.S. Pat. No. 4,216,501, issued Aug. 5, 1980, which is entitled OPTICAL ANTI-REFLECTIVE INFORMATION RECORD and which is incorporated herein by reference, disclosed a trilayer optical recording medium having a transparent spacer layer interposed between the reflective and absorptive layers of the bilayer recording medium.
Such recording media are substantially uniform in their structural and optical properties prior to exposure and thus contain no means by which a track can be defined or followed prior to the recording of information. A recording medium having a pregrooved substrate which has been proposed to provide these means, does not have the flexibility for changes of the track arrangement after manufacture. An alternative approach in which a portion of the absorptive layer is thermally removed by a laser beam to form the track has this flexibility but is undesirable since it involves a modification of the absorptive layer itself. It would be desirable to have a medium in which tracks can be defined after the fabrication of the medium without perturbing the absorptive layer.
SUMMARY OF THE INVENTION
The invention is an optical recording medium comprising a substrate, a light absorptive layer overlying the substrate, a buffer layer overlying the light absorptive layer and a masking layer overlying the buffer layer. The masking layer has one or more slots extending therethrough.
The invention also includes an information record comprising the recording medium of the invention having information recorded in the light absorptive layer as a series of regions of the light absorptive layer, underlying the slots in the masking layer, whose optical properties differ from those of the remainder of the light absorptive layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a radial cross-sectional view of the recording medium of the invention.
FIG. 2 is a cross-sectional view along the line 2--2 of FIG. 1.
FIGS. 3 and 4 are cross-sectional views of second and third embodiments of the recording medium of the invention.
FIGS. 5, 6 and 7 are cross-sectional views of different embodiments of the information record of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In FIGS. 1 and 2 the recording medium 10 comprises a substrate 12, a subbing layer 14 overlying a surface of the substrate 12, an absorptive layer 16 overlying the subbing layer 14, a buffer layer 18 overlying the absorptive layer 16 and a masking layer 20 overlying the buffer layer 18. The masking layer 20 has slots 22 extending therethrough with regions 24 of the masking layer 20 between the slots.
The substrate 12 may be a glass or a plastic material such as polyvinylchloride or (poly)methylmethacrylate typically in the form of a disc. A subbing layer 14 in the form of a non-conformal coating of a plastic material, such as an epoxy or acrylic resin having a microscopically smooth surface, may be deposited on the surface of the substrate 12 prior to the deposition of the absorptive layer 16.
The absorptive layer 16 may be a material such as titanium, rhodium, tellurium, selenium, alloys containing tellurium or selenium, or other chalcogenide alloys. The thickness of the absorptive layer 16 is chosen so as to provide a balance between the reflectivity and absorption of this layer at the wavelength of a recording light beam. Typically this layer is between about 10 nanometers and about 40 nanometers thick.
The buffer layer 18 is substantially transparent at the wavelength of the recording and readout light beams and can be an inorganic material such as an oxide of silicon, aluminum, titanium, or magnesium or an organic material such as an acrylic or epoxy resin. This layer is typically between about 50 and about 1000 nanometers thick and is preferably between about 100 and about 500 nanometers thick. A preferred thickness is an integral multiple and one-half the wavelength of the recording light beam in the material of which the buffer layer is composed.
The masking layer 20 is absorptive of light at the wavelength at which the slots are formed and at the wavelength of the recording light beam and can be a metal such as titanium, rhodium, tellurium, selenium, alloys containing tellurium or selenium or other chalcogenide alloys. This layer should be thick enough to provide absorption of light at the wavelength of the recording light beam but thin enough so that the slots can be formed using a focused light beam either at the wavelength of the recording light beam or another wavelength and is typically between about 5 and about 150 nanometers thick.
The slots 22 may be formed by ablation or melting using a focused laser beam or by well known photolithographic methods as a series of openings along a circular or spiral track. Although in FIG. 1 the slots are shown as lying along a circular track they may be distributed in any desired manner in the masking layer. This structure provides radial tracking capability during recording and readout of information from the absorptive layer since the difference in the reflected light intensity from the masking layer and slots can be converted into an electrical signal proportional to the radial tracking error.
In FIG. 3 and subsequent figures, the identification of the common elements of the subject embodiment and previous embodiments of the invention are the same. The second embodiment 30 differs from the first embodiment 10 in that a reflective layer 32 is interposed between the subbing layer 14 and the absorptive layer 16 and an overcoat layer 36 overlies the masking layer 20.
The reflective layer 32 reflects a substantial fraction, preferably at least 50 percent, of the incident light at the wavelengths of the recording and readout light beams and can be a metal such as aluminum or gold or a single or multilayer dielectric reflector.
In this embodiment the thickness of the absorptive layer 16 is chosen so as to reduce and preferably to minimize the reflectivity of the recording medium in the slotted portions at the wavelength of the recording light beam. Typically the thickness is between about 5 and about 100 nanometers and depends upon the optical constants of the materials which constitutes the reflective, absorptive and buffer layers.
The overcoat layer 36, preferably between 0.5 and about 1 millimeter thick, serves to reduce signal defects caused by surface dust which precipitates from the environment onto the recording medium. Useful materials for this layer include silicone, acrylic or epoxy resins.
The third embodiment 40 of FIG. 4 differs from the second embodiment 30 in that a spacer layer 42 is interposed between the light reflective layer 32 and the absorptive layer 16.
The spacer layer 42 is substantially transparent and non-scattering at the wavelengths of the recording and readout light beams and may be an oxide of silicon, titanium, aluminum or magnesium deposited by electron beam evaporation. Alternatively, organic materials deposited by evaporation, spin coating or glow discharge deposition may be used.
The thicknesses of the spacer layer 42 and the absorptive layer 16 are so related to the optical constants of the reflective layer 32, the spacer layer 42, the absorptive layer 16 and the buffer layer 18 that the reflectivity of the recording medium in the slotted portions is reduced and preferably minimized at the wavelength of the recording light beam. The spacer layer 42 is typically between about 10 nanometers and about 150 nanometers thick. The absorptive layer 16 is typically between about 3 nanometers and about 40 nanometers thick.
Information is recorded in these media by exposure to a modulated recording light beam which can form a pit or a reversible change in the optical properties of the absorptive layer; for example, a change in the degree of crystallinity of the absorptive layer. Information may be encoded as a variation in the length or spacing of the regions of the absorptive layer so changed. Since the recording light beam will only penetrate with substantially unchanged intensity to the absorptive layer in those regions underlying the slots in the masking layer, recording will only occur in such regions unless the intensity and duration of the recording light beam is sufficient to first form an opening in the masking layer and then produce the necessary change in the absorptive layer. This latter effect is minimized by use of a material for the masking layer which has a higher sensitivity at the recording wavelength. Alternatively, for the recording medium 30 or 40 the thicknesses of the layers may be chosen so as to produce a low reflectivity at the recording wavelength and a high reflectivity at the wavelength of the light beam used to form the slots.
In FIGS. 5, 6 and 7 the information track comprises a series of regions 52 in the absorptive layer 16 underlying the slots 22 in the masking layer 20. The regions 52 have different optical properties from the unexposed portions of the absorptive layer 16 and are spaced apart from one another by unexposed regions 54.
EXAMPLE
A trilayer recording medium fabricated according to the principles of the invention included a polyvinylchloride substrate coated with an acrylic resin (FUTURE™ acrylic finish manufactured by S. C. Johnson and Sons, Inc., Racine, Wis.) between 10 and 25 micrometers thick, an aluminum reflective layer 80 nanometers thick, a silicon dioxide spacer layer 62 nanometers thick, a tellurium light absorptive layer 5.5 nanometers thick, a silicon dioxide buffer layer 167 nanometers thick and a 30 nanometer thick tellurium masking layer. The medium was tested for its recording and readout properties in an optical system such as that disclosed by Spong, referred to above, which operated at a wavelength of 488 nanometers and had a focussed light beam spot size about 0.4 by about 0.6 micrometer in cross section. A slot along a spiral path was formed in the masking layer using a continuous wave incident light beam with about 10 milliwatts incident on the optical recording medium. An information track in the absorptive layer was then formed by recording an FM modulated video signal using a recording light beam having an incident power on the recording medium of about 20 milliwatts. Information tracks beneath the slots in the masking layer were observed using bright field optical microscopy. | An optical recording medium comprising a substrate, a light absorptive layer overlying the substrate, a buffer layer overlying the absorptive layer and a masking layer having slots therethrough overlying the buffer layer. The invention also includes an information record having information recorded in the absorptive layer as a series of regions of the absorptive layer, underlying the slots in the masking layer, whose optical properties differ from those of the remainder of the absorptive layer. The presence of the slots in this medium can provide a spatially varying recording sensitivity, track identification and a means for obtaining a radial tracking error signal. | 6 |
This is a division of application Ser. No. 777,873, filed 9/20/85, now U.S. Pat. No. 4,606,496.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention pertains generally to the field of processes for forming pressed paperboard products such as paper trays and plates and to the products formed by such processes.
2. Description of the Prior Art
Formed fiber containers, such as paper plates and trays, are commonly produced either by molding fibers from a pulp slurry into the desired form of the container or by pressing a paperboard blank between forming dies into the desired shape. The molded pulp articles, after drying, are fairly strong and rigid but generally have rough surface characteristics and are not usually coated so that they are susceptible to penetration by water, oil and other liquids. Pressed paperboard containers, on the other hand, can be decorated and coated with a liquid-proof coating before being stamped by the forming dies into the desired shape. Pressed paperboard containers generally cost less and require less storage space than the molded pulp articles. Large numbers of paper plates and similar products are produced by each of these methods every year at relatively low unit cost. These products come in many different shapes, rectangular or polygonal as well as round, and in multicompartment configurations.
Pressed paperboard containers tend to have somewhat less strength and rigidity than do comparable containers made by the pulp molding processes. Much of the strength and resistance to bending of a plate-like container made by either process lies in the side wall and rim areas which surround the center or bottom portion of the container. When in use, such containers are supported by the rim and side wall while the weight held by the container is located on the bottom portion. Thus, the rim and side wall generally is placed in tension when the container is being used.
In plate-like structures made by the pulp molding process, the side wall and overturned rim of the plate are unitary, cohesive fibrous structures which have good resistance to bending as long as they are not damaged or split. Because the rim and side wall of the pulp molded containers are of a cohesive, unitary structure, they may be placed under considerable tension without failing.
In contrast, when a container is made by pressing a paperboard blank, the flat blank must be distorted and changed in area in order to form the blank into the desired three dimensional shape. This necessary distortion results in seams or pleats in the sidewall and rim, the areas of the container which are reduced in press forming the container. These seams or pleats constitute material fault lines in the side wall and rim areas about which such containers bend more readily than do containers having unflawed side walls and rims. Moreover, such seams or pleats have a tendancy to return to their original shape - flat. The necessary location of these pleats in the side wall and rim of pressed paperboard containers places the greatest weakness in the area requiring the greatest strength. Such containers have been unable to support loads comparable to pulp molded containers since, when in use, the greater the load the higher the tension imposed on the rim and side wall. Imposing tension on pleats merely enhances the tendancy to flatten. Accordingly, known pressed paperboard containers have significantly less load carrying ability than do pulp molded containers. A pressed paperboard plate being less costly than its pulp molded competitor would have significant commercial value if it had comparable strength and rigidity.
Many efforts have been made to strengthen pressed paperboard containers while accommodating the necessary reduction in area at the side walls and rims. Blanks from which paperboard containers are pressed have been provided with score lines at their periphery to eliminate the random creation of seams or pleats. The score lines define the locations of the seams or pleats. Score lines, sometimes in conjunction with special die shapes, have been used to create flutes or corrugations in the sidewall and rim for aesthetic and structural purposes. The additional cost and complexity of dies used to create flutes or corrugations in the side wall of such containers is a cost disadvantage, and the containers are not significantly more rigid than prior paperboard containers.
Whether the area reduction of the side wall and rim is accommodated by pleats, seams, flutes or corrugations, the basic difficulty has been that under limited stress the paperboard will tend to return to its original shape.
To overcome this tendency, it has been suggested that the rim be subjected to various strengthening techniques. The earliest efforts comprised the addition of several thicknesses of paperboard at the rim. This container, however, required additional manufacturing steps and increased the cost and required storage space of the containers. Examples of this technique may be seen in Moore, U.S. Pat. No. 2,627,051, and Bothe, U.S. Pat. No. 2,668,101.
Wilson, British Pat. No. 981,667, teaches subjecting the lip or rim of the container to pressure greater than that imposed on the rest of the container in the belief that the additional compression would resist the tendency of the rim to return to its original shape. While the rim of the device of Wilson is flattened, the side wall of the container is corrugated presenting the disadvantages referred to above.
More recently, as disclosed in a commonly-assigned, copending U.S. application, Ser. No. 367,880, filed Apr. 13, 1982, improved rigidity in a pressed paperboard container has been achieved by application of pressure and temperature to the rim of the container while applying substantially no pressure to the sidewall and bottom wall. In particular, the container had a generally planar bottom wall, a side wall upwardly rising from the bottom wall periphery and an overturned rim extending from the sidewall periphery. During integrally press-forming of the container, substantially no pressure was applied to the bottom and side walls and pressure was applied to the overturned rim. The amount of pressure imposed on the rim was approximately 200-250 psi and gradually increased from the juncture of the rim and side wall to the peripheral edge of the rim. The pleats formed in the rim were compressed to the thickness of the rim while the pleats formed in the side wall were not subject to any significant pressure. The container thus formed provided a significant improvement over prior paperboard containers.
The present invention is a dramatic improvement over prior paperboard containers. The containers of the invention provide a 300% improvement in rigidity over earlier paperboard containers and approximately a 50% increase in rigidity over containers disclosed in U.S. application Ser. No. 367,880.
SUMMARY OF THE INVENTION
As embodied and broadly described herein, the invention is a paperboard container comprising a bottom wall, an upwardly extending side wall, a first curved portion joining the side wall to the periphery of the bottom wall, an outwardly extending rim, a second curved portion joining the rim to the periphery of the side wall, and a downwardly curved lip outwardly extending from the periphery of the rim. The container is integrally formed from a substantially homogeneous paperboard blank by a press such that the thickness of the side wall, second curved portion and rim is less than that of the bottom wall, first curved portion and lip. The container includes a plurality of densified regions radially extending through and circumferentially spaced about annular sections of the side wall, second curved portion and rim. The densified regions are formed from pleats including at least three layers of paperboard created during press forming of the blank which are subjected to sufficient pressure to reform the pleats into cohesive, fibrous structures having a density substantially greater than and a thickness substantially equal to adjacent areas of the side wall, second curved portion and rim.
Preferably, the bottom wall and rim of the container are generally planar and substantially parallel, and the side wall is substantially planar and is outwardly inclined to the bottom wall.
In a preferred embodiment, the thickness of the side wall is equal to that of the rim, and the thickness of the bottom wall is substantially equal to that of the blank.
Preferably the paperboard blank has a moisture content by weight of 4% to 12% and is pressed at a temperature between 200° F. and 400° F. The force applied by the press is preferably in the range of 6000 lbs to 30000 lbs with a pressure in the range of 300 psi to 1500 psi being applied to the side wall, second curved portion and rim.
The paperboard blank may include a plurality of score lines at which pleats are formed and transformed into densified regions.
The invention is also directed to a method of forming containers from a flat, substantially homogeneous paperboard blank comprising shaping the blank into a formed container having a bottom wall, an upturned side wall extending from the bottom wall, a rim outwardly extending from the side wall and a lip downwardly extending from the rim and including pleats formed in the side wall, rim and lip. Sufficient heat and pressure are applied to the side wall and rim to decrease their thickness to less than the blank and to transform the pleats into cohesive fibrous strutures having a density greater than and a thickness substantially equal to adjacent areas of the side wall and rim.
Preferably the container is pressed at a temperature of approximately 200° F. to 400° F., and the side wall and rim is subject to pressure in the range of 300 psi to 1500 psi.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention, and, together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a section of a plate-like container in accordance with the invention.
FIG. 2 is a graphic representation of the cross-sectional shape of one-half of the container of the invention.
FIG. 3 is a plan view of a blank for a plate-like container of the invention.
FIG. 4 is a graphic representation of a cross-section of a pleat taken along line IVIV of FIG. 1 before application of pressure to the side wall and rim.
FIG. 5 is a photomicrograph (100×) of a cross-section of the bottom wall portion of a paperboard plate formed in accordance with the invention.
FIG. 6 is a photomicrograph (100×) of a cross-section of a densified region in the side wall of a paperboard plate formed in accordance with the invention.
FIG. 7 is a photomicrograph (100×) of a cross-section of a densified region in the rim of a paperboard plate formed in accordance with the invention.
FIG. 8 is a photomicrograph (100×) of a cross-section of a pleat in the lip of a paperboard plate formed in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.
In accordance with the invention, the paperboard container comprises a bottom wall, an upwardly extending side wall, a first curved portion joining the side wall to the periphery of the bottom wall, an outwardly extending rim, a second curved portion joining the rim to the periphery of the side wall, and a downwardly curved lip outwardly extending from the periphery of the rim.
The container of the invention may be circular, as in a plate or bowl, or it may be square or rectangular with annular corners, as in a tray. Other shapes are contemplated including compartmented trays or plates and oval platters. In each contemplated embodiment all corners are rounded or curved which are represented by the section depicted in FIG. 1
In the preferred embodiment depicted in FIG. 1, container 10 comprises bottom wall 12, upwardly extending side wall 14, first curved portion 16 joining side wall 14 to the periphery of bottom wall 12, rim 18, second curved portion 20 joining rim 18 to the periphery of side wall 14, and a downwardly curved lip 22 outwardly extending from the periphery of rim 18. The phantom lines in FIG. 1 have been provided for ease in identifying the various structural segments of the container and do not represent lines actually appearing on the container. Moreover, the phantom lines do not represent actual demarcations between the segments; as explained below, in each embodiment the size relationships between the segments vary.
As depicted in FIG. 2, bottom wall 12 is generally co-planar with an imaginary plane defined by its periphery 24. Bottom wall 12 may gradually diverge toward its center 26 from the periphery 24.
In the preferred embodiment, rim 18 is generally planar and generally parallel to a plane defined by the periphery 24 of bottom wall 12. Also, side wall 14 is generally planar and outwardly inclined to bottom wall 12.
As previously mentioned, the container of the invention may be embodied in various shapes and sizes. For example, the container may be circular plates having different diameters, bowls of different sizes, platters and trays. In each case, however, the container shape will conform to certain geometric relationships found to contribute to the improved rigidity. The general geometric shape providing such rigidity has been set forth above. Certain specific geometric factors, however, are useful in describing the various shapes contemplated by the subject invention.
In FIG. 2 the following designations are used:
R--the radial distance from the center 26 of bottom wall 12 to the distal end 30 of lip 22.
H--the axial height of rim 18 above a plane defined by the periphery 24 of bottom wall 12.
C 1 --the radius of curvature of first curved portion 16.
C 2 --the radius of curvature of second curved portion 20.
F--the radial width of rim 18.
L H --the axial height of lip 22
L R --the radial width of lip 22.
T o --the average thickness of bottom wall 12.
T s --the average thickness of side wall 14.
T F --the average thickness of rim 18
Δ--the angle of inclination of side wall 14 to bottom wall 12.
Using the geometric factors depicted in FIG. 2, the annular portions of the contemplated shapes of the invention preferably fall within the following ranges.
(1) R=2 to 8 inches
(2) H/R=0.1 to 0.8
(3) C 1 =7/16 to 3/4 inches
(4) C 2 =3/16 to 1/4 inches
(5) C 1 >C 2
(6) F/R=0.02 to 0.1
(7) L H /R=0.02 to 0.1
(8) L R /R=0.02 to 0.1
(9) Δ=30° to 90°
(10) C 1 /R=0.05 to 0.3
(11) C 2 /R=0.01 to 0.1
In accordance with the invention, the container is integrally formed from a substantially homogeneous paperboard blank by a press. Preferably, the blank is a unitary, flat piece of paperboard stock conventionally produced by a wet laid papermaking process and typically available in the form of a continuous web on a roll.
The paperboard stock used for the blank preferably has a weight in the range of 100 pounds to 400 pounds per ream (3000 square feet) and a thickness or caliper in the range of about 0.008 inch to 0.050 inch. Paperboard having basis weight and caliper in the lower end of the range may be preferred for ease of forming and economic reasons. Of course, this must be balanced against the lower strength and rigidity obtained with the lighter paperboard. No matter what paperboard is selected, the containers of the invention have greater rigidity than prior containers formed of comparable paperboard.
Preferably, the paperboard of the blank has a density, in basis weight per 0.001 inch of caliper, in the range of 8 to 12.
The paperboard comprising the blank is typically bleached pulp furnish with double clay coating on one side. Preferably, the paperboard stock has a moisture content (generally water) varying from 4.0% to 12.0% by weight. In forming the containers of the invention, the best results are achieved when the blank has a water content by weight of 9% to 11%.
While various end uses for the containers of the invention are contemplated, typically they are used to holding food and liquids. Accordingly, one side of the blank is preferably coated with one or more layers of a known liquid-proof coating material, such as a first layer of polyvinyl acetate emulsion and a second layer of nitrocellulose lacquer. For aesthetic purposes, one side of the blank may be printed with a design or other printing before application of the liquid-proof coatings. It is also preferred that the coatings selected be heat resistant.
Blank 40 depicted in FIG. 3 is the type generally used to form circular containers such as plates and bowls. Preferably the blank includes a plurality of radially extending score lines 42 circumferentially disposed around the periphery of blank 40. The score lines define locations at which pleats are created in the side wall, second curved portion, rim and lip during forming of the container. The number of score lines 42 may vary between 10 and 100 for a circular container depending on the rigidity desired and on the radius R and height H of the container. Generally, the fewer score lines, and therefore, the fewer resulting pleats, the more rigid the resulting container. Significant to this invention, the fewer score lines for a given reduction in radius at the side wall and rim the greater the overlap of paperboard at the pleats which places more fiber in the area of densification. Thus, with appropriate pressure, moisture and temperature conditions, improved bonding of the fiber network is achieved. This can be referred to as pleat bonding. Where the contemplated container is other than circular, score lines are provided in the blank in areas to be formed into annular portions of the container.
The press used to form the container of the invention is preferably an articulated press of the type disclosed in Patterson, U.S. Pat. No. 4,149,841.
The preferred press includes male and female die surfaces which define the shape and thickness of the container. Preferably, at least one die surface is heated so as to maintain a temperature during pressing of the blank in the range of 200° F. to 400° F.
In accordance with the invention, the container is formed by a press such that the thickness of the side wall, second curved portion and rim is less than that of the bottom wall, first curved portion and lip. In the preferred embodiment, the press applies substantially zero pressure to the bottom wall; the thickness of the bottom wall in the resulting container being substantially equal to the blank.
In the preferred embodiment, the ratio of thicknesses of the bottom wall, side wall and rim to the radius of the container or annular portion are in the following ranges:
(12) T o /R=0.002 to 0.008
(13) T s /R=0.001 to 0.007
(14) T f /R=0.001 to 0.007
Depending on the embodiment, T s may equal T f , and it is preferred that T s and T f <T o . In some embodiment, due to paperboard weight and press parameters, T s may be less than T f .
To achieve the preferred thicknesses of the side wall and rim, preferably the press imposes on the side wall, second curved portion and rim a pressure in the range of 300 psi to 1500 psi.
While in the earlier container disclosed in co-pending application Ser. No. 367,880, the distal edge of the lip was subjected to the greatest pressure and had the least thickness, in the present invention it has been found that application of the significant pressure contemplated causes damage to the lip. Furthermore, it has been found that the lip of the container of this invention does not contribute as much to rigidity as does the side wall and rim. Accordingly, in the preferred embodiment, the lip has a thickness greater than the rim or sidewall but somewhat less than the bottom wall.
In accordance with the invention, the container includes a plurality of densified regions radially extending through and circumferentially spaced about annular sections of the side wall, second curved portion and rim. The densified regions are formed from pleats including at least three layers of paperboard created during pressforming of the blank and subjected to sufficient pressure to reform the pleats into cohesive, fibrous structures having a density substantially greater than and a thickness substantially equal to adjacent areas of the side wall, second curved portion and rim.
As depicted in FIG. 1, the preferred embodiment of the invention includes a plurality of densified regions 25 radially extending through and circumferentially spaced about the annular section of side wall 14, first curved portion 20, and rim 18. These densified regions are formed from pleats 50, exageratedly represented in FIG. 4, including at least three layers 52, 54, 56 of paperboard created at the score lines during forming of the container. These pleats are subjected to sufficient pressure to reform the fibers of the separate layers 52, 54, 56 of paperboard into a cohesive, fibrous structure.
Reformation of the pleats into cohesive, fibrous structures substantially strengthens the weakest part of a pressed paperboard container. Where the pleats no longer comprise separate layers of paperboard, there is no tendancy for the container to return to its original shape. Indeed, the densified regions resist efforts to flatten the side wall and rim as such would require increasing the area of the side wall and rim.
Preferably, the press forming the container imposes a force in the range of 6000 lbs to 30,000 lbs between the die surfaces.
It will be apparent that if substantially zero pressure is imposed on the bottom wall, virtually all of the force between the dies of the press is imposed on the other areas of the container. To achieve such a distribution of pressure, the preferred die structure provides a spacing between die surfaces at the bottom wall which is substantially equal to or greater than the blank thickness. The die spacings at the side wall, second curved portion, rim and lip are less than the blank thickness. In this way the amount of pressure imposed can be different at different lines of circumference.
Preferably, the spacing between the die surfaces at the side wall is equal to that at the rim, and the spacing at the lip is greater than at the side wall and rim and equal to or less than that of the blank. The die surface spacing at the side wall may be less than that at the rim in some embodiments.
The pressure imposed on the side wall, second curved portion, rim and lip, of course, depends on the respective areas of those regions which will vary with different contemplated shapes and sizes.
For comparison, in a typical 9 inch diameter (after forming) paper plate, a typical force between die surfaces of 6000 pounds if uniformly distributed over the area of the plate results in a pressure of about 90 psi over the entire plate area.
In a 9 inch plate formed as taught in the co-pending application, pressures in the range of 200 psi are imposed on the rim and lip. This is achieved by distributing the die force of about 6000 pounds only over the area of the rim and lip.
In a 9 inch plate formed in accordance with the invention, the side wall, second curved portion and rim receive a pressure in excess of 500 psi thereby substantially increasing the densities of these regions.
During the pressing process, the initial stage defines the basic shape of the container. The bottom wall, side wall, rim and curved portions are formed and the pleats or folds are created in the side wall and rim. At this point only nominal pressure has been applied to the container. As the process continues, pressure is first applied only to the pleats which are raised above the adjacent surfaces. Thus, the full force of the press is distributed over the very small area comprising the pleats thereby imposing an instantaneous pressure on the pleats which is substantially greater than subsequently imposed on the full area of the side wall and rim. Compressing three or more layers of paperboard with such pressure breaks down the fiber matrix of the paperboard and reforms the fibers into a new cohesive, fibrous structure. As the process continues the pleats are reduced in thickness to that of the adjacent side wall and rim, and the force of the press is distributed over a large area. At this point the pressure reduces the thickness of the side wall and rim as well as the newly-formed densified regions to increase the density of the side wall and rim and to further increase the density of the densified regions.
In the example referred to above, the initial pressure imposed on the pleats may be approximately 12,000 psi. Such pressure, in conjunction with press temperature and blank moisture content, disassociates the fibers from their previous structure in the three layers of paperboard and reforms the fibers into a new bonded network constituting a cohesive fibrous structure. Since the die surfaces acting on the side wall, second curved portion and rim are uniform, the densified regions have and retain a thickness substantially equal to that of the annularly adjacent areas. As the densified regions are cohesive structures, they will withstand tension to levels approaching that of pulp molded containers. The resulting containers, while not as strong as pulp molded containers, provide substantially greater rigidity than prior paperboard containers and are very competitive with pulp molded containers because the cost of the containers of the invention is substantially less.
The effect of application of such pressures may be seen in FIGS. 5-8 which are micrographs of cross-sections through a paper plate made in accordance with the present invention. The plate was formed of 160 pound per ream, 0.015 inch caliper, low density bleached plate stock, clay coated on one side, printed on one surface with standard inks and coated with two layers of liquid-proof material. The density of the paperboard stock, in basis weight per 0.001 inch of thickness, averages about 10.7.
The view of FIG. 5 (100×) is a crosssection through the approximate center of the plate made in accordance with the present invention and shows relatively even surfaces. The fiber network seen in FIG. 5 has evident many ends of round fibers with substantial voids distributed throughout the matrix of fibers within the board which is charactristic of the unpressed, low density paperboard stock material from which the pressed plate is made. The average thickness is about 0.015 inch. FIG. 6 (100×) is a photomicrograph taken along a cut through the side wall of the plate, with the cut lying along a circumferential line through one of the densified regions of the pressed plate. FIG. 7 (100×) is a photomicrograph taken along a cut through the rim of the plate, the cut lying along a circumferential line through one of the densified regions. The paperboard in the area through which the sections of FIG. 6 and 7 were taken is highly compacted, leaving very little empty space between the fibers; the structure of the densified region consists of compressed bonded fibers. The paperboard in the lip shown in FIG. 8 has been slightly compacted compared to the bottom wall shown in FIG. 5, but since it has been subjected to less pressure than the side wall and rim seen in FIGS. 6 and 7, the pleat structure is more apparent.
The thickness of the cross-sections, occurring at the densified regions shown, is about 0.012 inch at the side wall (FIG. 6) and 0.013 inch at the rim (FIG. 7), substantially less than the thickness (0.015 inch) of the bottom wall (FIG. 5). Away from the densified regions the thickness of the side wall and rim is about the same as the densified regions and thinner than the bottom wall. Since the densified regions contain substantially more solid fibrous material than the rest of the paperboard; perhaps 40 to 100% more, the density of the densified regions is substantially greater than the remainder of the container.
The surface of the paperboard of FIGS. 6 and 7 are essentially smooth and continuous. The uneven surfaces seen in FIG. 8 are similar to the appearance of pleats in the rim and side wall regions prior to the application of high pressure. As seen in FIGS. 6 and 7, such pressure has caused virtually all traces of the pleat to disappear and the paperboard fibers have been essentially bonded together, leaving only the vestigial traces of the fold remaining. Strength measurements (tension within the elastic limit of the densified region) indicate a strength of at least twice and up to five times that of containers formed with lower pressures. The heat and pressure applied during the forming process may be sufficient to cause some melting and surface adhesion between the abutting coated surfaces which lie along the fold lines, although the outer coating is preferably resistant to heat and pressure.
The cross-sections through a plate of the invention taken across the side wall and rim, FIGS. 6 and 7, shows that the fibers within the plate are substantially compacted, and virtually all evidence of the pleats that existed in the side wall and rim areas during the forming operation have disappeared, except for small areas where the overcoated tops of the folded regions have been laid back upon themselves. The fibers are tightly and closely compressed together, leaving very few voids or air spaces, and the basis weight of the paperboard in these regions are substantially uniform because of the compaction of the fibers. The densification of the plate in the side wall and rim areas and the reformation of the pleats into substantially integral structures results in the marked increases in plate rigidity.
Due to the photomicrographic process used to produce FIGS. 5-8, certain discoloration and focus abnormalities appear. These problems are particularly evident in FIG. 6 wherein dark lines and blurred areas appear. These areas of FIG. 6, and to some extent in FIG. 7, are not intended to represent structural aspects of the pressed fiberboard and may be ignored.
Containers formed in accordance with the invention have much greater rigidity than comparable containers formed of similar paperboard blank material in accordance with the prior art processes. To provide a comparison of the rigidity of various plates formed in the configuration of the plate 10, a test procedure has been used which measures the force that the plate exerts in resistance to a standard amount of deflection. The test fixture utilized, a Marks II Plate Rigidity Tester, has a wedge shaped support platform on which the plate rests. A pair of plate guide posts are mounted to the support platform at positions approximately equal to the radius of the plate from the apex of the wedge shaped platform. The paper plate is laid on the support platform with its edges abutting the two guide posts so that the platform extends out to the center of the plate. A straight leveling bar, mounted for up and down movement parallel to the support platform, is then moved downwardly until it contacts the top of the rim on either side of the plate so that the plate is lightly held between the platform and the horizontal leveling bar. The probe of a movable force gauge, such as a Hunter Force Gauge, is then moved into position to just contact the top of the rim under the leveling bar at the unsupported side of the plate. The probe is lowered to deflect the rim downwardly one-half inch, and the force exerted by the deflected plate on the test probe is measured. For typical prior commercially produced 9 inch paper plates rigidity readings made as described above generally averaged about 60 grams or less (using the Hunter Force Gauge), and the plate as shown in co-pending application, Ser. No. 367,880, had an average rigidity of about 90 grams/0.5 inch deflection. A comparable 9 inch plate produced in accordance with the invention has rigidity in the range of 140 gms to 280 gms/0.5 inch deflection depending on the paper weight used and the number of score lines.
Of course, successful manufacture of containers in accordance with the invention requires attention to details of the pressing process in accordance with good manufacturing techniques. For example, the die surfaces of the press preferably would be perfectly symmetrical ground the entire circumference. This not being entirely practical in view of machining requirements, the critical tolerances are those within the side wall, second curved portion and rim areas. It is highly preferred that the die spacings in these areas be uniform along any circumferential line. Additionally, it is necessary that male and female die surfaces be properly aligned.
It is understood that the invention is not confined to the particular construction and arrangement or to the particular process techniques described herein; the invention includes modified forms thereof within the scope of the following claims. | A method of forming a container from a flat, substantially homogeneous blank of fibrous substrate, comprising the steps of shaping the blank into a formed container having a bottom wall, an up-turned side wall extending from the bottom wall, a rim outwardly extending from the side wall and a lip downwardly curving from the rim and including a plurality of radially-extending, circumferentially-spaced pleats formed in the side wall, rim, and lip, each pleat including at least three layers of the blank; and applying sufficient heat and pressure to the side wall and rim to decrease the thickness thereof to less than that of the blank and to transform each pleat into a substantially integrated fibrous structure in which the constituent layers generally lack individual identity, each structure having a density greater than and a thickness substantially equal to adjacent areas of the side wall and rim. | 1 |
BACKGROUND TO THE TECHNOLOGY
[0001] 1. Field
[0002] The present invention relates to new apparatuses useful for the conversion by steam reforming of hydrocarbons and fossil fuels into hydrogen that is the feedstock for fuel cell stacks that generate electricity. Still more particularly, the present invention is concerned with particular equipment, a hydrocarbon generating apparatus, a single vessel heat integrated multi-stage water-gas shift reactor, a multiple heat source boiler, a multi-functional heat exchanger, and a multi-staged preferential oxidation reactor, and the combination thereof into a fuel processor. The present invention is further related to the integration of said fuel processor with a fuel cell stack.
[0003] 2. Description of the prior art
[0004] Distributed electrical power systems for residences can be realized by the combination and integration of various equipment. This invention relates to improvements in specific fuel processing equipment used to produce hydrogen for a fuel cell stack and more particular to the synergies that can be obtained from specific methods of combination and integration of said fuel cell stack operating on hydrogen with said fuel processing equipment that produces the required hydrogen, to form systems that are suitable for residential distributed power generation.
[0005] However means of improving fuel processing apparatuses are continually being sought, and as a consequence many patents have issued in this area.
[0006] U.S. Pat. No. 4,847,051 claims a fuel processor in a fuel cell power plant. It describes the advantages of sleeves about the individual catalyst tubes within the reformer. It does not suggest any particular technique for combining the reformer with the fuel cell.
[0007] U.S. Pat. No. 4,650,727 discloses a fuel cell power system combining a fuel cell and a fuel processing apparatus that operates on an organic fuel such as methanol using a fuel conversion catalyst specifically identified as a partially reduced copper oxide and zinc oxide solid. Although this catalyst has frequently been used for methanol conversion, it is well known that other catalysts are superior to it far steam reforming fuel feed stocks other than methanol. Since systems to distribute methanol to residences are not generally available whereas distribution systems are in place for fuels such as natural gas and liquefied petroleum gas, methanol is unlikely to be a fuel for residential power generation.
[0008] U.S. Pat. No. 5,985,474 discloses a combination of a fuel cell and a furnace that are heated with a hydrogen containing reformate produced by a fuel processor or reformer, in order to provide both electricity and heat to a residence. Although it is essential to use a hydrogen containing feedstock as the fuel for the fuel cell, there are other possibilities for the fuel used in furnaces. It is much more efficient to use a fuel such as natural gas or liquefied petroleum gas directly in a furnace than to use energy to convert that fuel to a hydrogen containing reformate and subsequently burn the hydrogen containing reformate in the furnace.
[0009] U.S. Pat. No. 5,401,589 discloses a combination of a fuel cell and a reformer to generate electrical power. For example, waste gases were fed to a turbine to generate electricity. The various components in the systems functioned independently of one another. Any integration of the fuel cell with the fuel processor was limited.
[0010] It is the object of the present invention to provide an improved fuel processing apparatus comprised of a hydrogen generating apparatus, a single vessel heat integrated multi-stage water-gas shift reactor, a multifunctional heat exchanger, a multiple source boiler, and a single vessel water heat exchanged multi-staged preferential oxidation reactor, that when combined to form a fuel processing apparatus satisfy the criteria of compact size for residential application, short start-up times that are consistent with residential needs, rapid responses to transient changes in demand for electricity, and maximum energy efficiency. It is a further object of the present invention to integrate a fuel cell stack with the said fuel processing apparatus by multiple means.
[0011] It is a further object of the present invention to provide various embodiments of a fuel processor apparatus having the aforesaid characteristics, including methods of further improvement by operating the fuel processing apparatus with a fuel cell stack in a manner whereby integration is performed by more that one means simultaneously to achieve various advantageous results.
[0012] The present invention will be best understood, and further objects and advantages thereof will be apparent, from the following description when read in connection with the accompanying drawings.
SUMMARY OF THE INVENTION
[0013] Improvements over the prior art are provided according to the present invention by first improving each major equipment sub-system of the fuel processor. According to the present invention the hydrogen generating apparatus is equipped with a side mounted metal fiber burner that operates in a blue flame mode that is located just above the burner surface producing heat in a convective way. The single vessel heat-integrated multi-stage water-gas shift reactors combine two or more water-gas shift reactors within a single vessel having means of communicating with a multi-functional heat exchanger that decreases the temperature of the process gas from the high temperature shift reactor to a desired value while simultaneously transferring the unwanted heat to water that is recirculated to a boiler for the generation of steam. The multi-functional heat exchanger not only transfers heat from the process gas from the high temperature water gas shift reactor, it also contains an immersion electrical heater that can transfer heat via recirculated water to produce steam. The immersion water heater is particularly important for rapid start-up when the system has not been used for an extended period. The multiple heat source boiler obtains heat from the process gas from the high temperature water-gas reactor and from the electrical immersion heater as described above. In addition heat is received from the process gas from the low temperature shift reactor and from the combustion gas mixture from the combustion chamber. The single vessel water exchanged multi-stage preferential oxidation reactor is divided into at least two stages. Make-up air is added to each of the stages, thereby providing an improved distribution of air and ensuring that not all the air is used in the first part of the reactor. Each preferential oxidation reactor stage has a particular shell and tube design. In one embodiment of the present invention, warm cooling water exiting from the fuel cell stack is used on the shell side. It acts as a sink for the exothermic heat of reaction from the preferential oxidation reaction that must be managed in the first stage of the preferential oxidation reaction. It also provides a controlled temperature to ensure that an adequate rate of preferential oxidation is maintained and that the small quantities of carbon monoxide that enter the second stage are converted to obtain the 10 ppm carbon monoxide specification.
[0014] Another aspect of the present invention provides for the integration of the fuel processing apparatus with a fuel cell stack through more than one means simultaneously. As described above a first means of integrating the fuel processor with the fuel cell is through the warm cooling water exiting from said fuel cell stack that is subsequently used on a shell side of the preferential oxidation reactor. A second means of integrating the two apparatuses is by routing the anode off-gas containing un-reacted hydrogen from said fuel cell stack to the hydrogen generating apparatus within said fuel processing apparatus for burning inside the combustion chamber. A third means of integrating the two apparatuses is through the supply stream of the hydrogen containing product process gas that is made by said fuel processing apparatus and consumed by said fuel cell stack.
BRIEF DESCRIPTION OF DRAWINGS
[0015] [0015]FIG. 1 is a process flow diagram illustrating the apparatus and flow paths of the fuel processing apparatus according to the present invention.
[0016] [0016]FIG. 2 is a diagram illustrating one preferred embodiment of the hydrogen generation apparatus including a combustion chamber, a burner, a steam reformer catalytic reactor, and a heat exchanger.
[0017] [0017]FIG. 3 is a diagram illustrating one preferred embodiment of the single vessel heat-integrated multi-stage water-gas shift reactor.
[0018] [0018]FIG. 4 is a diagram illustrating one preferred embodiment of the multiple heat source boiler.
[0019] [0019]FIG. 5 is a diagram illustrating one preferred embodiment of the multi-function heat exchanger.
[0020] [0020]FIG. 6 is a diagram illustrating one preferred embodiment of the single vessel water heat exchanged multi-staged preferential oxidation reactor.
DETAILED DESCRIPTION OF THE INVENTION:
[0021] The apparatus and equipment for generating a hydrogen-containing gas of the quality necessary for sustained operation of a polymer electrolyte fuel cell stack is illustrated in FIG. 1, which is one embodiment of the present invention. A hydrocarbon feedstock or fossil fuel, such as natural gas, liquefied petroleum gas, diesel fuel, 1 is passed through a fixed bed of adsorbent 2 , preferably an activated carbon adsorbent or an activated carbon adsorbent impregnated with copper, wherein odorants such as mercaptans or hydrothiophenes are adsorbed to produce a hydrocarbon feedstock that is almost sulfur free, having a sulfur content less than the specification of the catalysts used to within the fuel processing apparatus to produce a hydrogen-containing gas mixture. A portion of the desulfurized hydrocarbon 3 is mixed with steam 5 to become the steam reformer catalytic reactor feedstock mixture. Another portion of the desulfurized hydrocarbon 4 is mixed with other gases and used as a combustion fuel. The steam reformer catalytic reactor feedstock mixture is heated in the feedstock pre-heat exchanger 6 by heat transferred from the steam reformer catalytic reactor product gases, 10 to become the heated steam reformer catalytic reactor gas feedstock, 7 . The feedstock 7 is reacted via the steam reforming reaction to form a reformate product gas mixture, 10 comprised of carbon monoxide, hydrogen, and other gases after passing through a fixed bed of steam reforming catalyst contained in the U-tube shaped steam reformer catalytic reaction vessel, 8 that is part of the hydrogen generating apparatus, 9 . A suitable steam reforming catalyst is commercially available as G-91 from Sud-Chemie. After passing through the pre-heat exchanger 6 and being cooled the cooled steam reformer catalytic reactor product gas mixture 11 enters the fixed bed of high temperature water-gas shift catalyst contained within the single vessel heat integrated multi-stage water-gas shift reactor, 12 . A suitable high temperature water-gas catalyst is available commercially as G-3 C from Sud-Chemie. The product gas mixture from the fixed bed of high temperature water-gas shift catalyst, 13 flows through multi-functional heat exchanger 14 where its temperature is decreased and it becomes the feedstock 18 to the fixed bed of low temperature water-gas shift catalyst contained within the single vessel heat integrated multi-stage water-gas shift reactor, 12 . A suitable low temperature water-gas shift catalyst is available commercially as C 18-8 from Sud-Chemie. The water-gas shift reaction of carbon monoxide with water to form an additional quantity of hydrogen plus carbon dioxide occurs within the single vessel heat integrated multi-stage water-gas shift catalysts. The product process gas from the single vessel heat integrated multi-stage water-gas shift reactor 19 flows through the inside of some of the tubes within the multiple heat source boiler 20 where the heat it transfers to the water within the multiple heat source boiler is some of the heat necessary to generate the amount of steam required for steam reforming reaction. The cooled product process gas from the multiple heat source boiler 21 passes through an air cooled heat exchanger 22 to decrease its temperature below its dew point and thereby to condense some of its water to form a vapor/liquid phase mixture, 23 .
[0022] The mixture passes into a separator vessel 24 to form a vapor stream 25 and a liquid water stream 43 . The vapor stream 24 is mixed with some of the air 27 from an air blower 26 and enters the first catalyst stage of a single vessel water heat exchanged multi-staged preferential oxidation reactor 28 . After the first stage within the single vessel water heat exchanged multi-stage preferential oxidation reactor 28 , the product process gas is mixed with the balance of air 27 from the air blower 26 and is passed through a second catalyst stage within the single vessel water-heated multi-stage preferential oxidation reactor 28 . The temperature of the catalyst stages within the single vessel water heat exchanged multi-stage preferential oxidation reactor is maintained by circulating a water stream such as the cooling water from the fuel cell stack. The product process gas from the single vessel water heat exchanged multi-stage preferential oxidation reactor 31 is the hydrogen containing feedstock gas for the fuel cell stack 32 . A portion of the hydrogen in the fuel cell stack feedstock 31 is consumed in the fuel cell stack. The portion of hydrogen that is not consumed remains in the anode off gas 33 from the fuel cell stack that is used as one of the fuels that are burned in the combustion chamber of the hydrogen generating apparatus 9 to supply the endothermic heat of the steam reforming reaction. The combustion product gas 36 from the hydrogen generating apparatus flows through the inside of some of the tubes in the multiple heat source boiler where the heat that is transferred to the water is some of the heat necessary to generate the steam 5 required for the hydrogen generating apparatus. The combustion product gas 37 leaving boiler 20 transfers some of its heat in heat exchanger 38 to the boiler feed water 43 that enters boiler 20 . Domestic water 40 is treated by chlorine removal and ion exchange in a water treatment cartridge 41 to produce make-up water 42 that initially flows into the bottom of separator 24 and ultimately into boiler 20 .
[0023] The components of the equipment used in the hydrogen generating apparatus, including a combustion chamber, a burner, a steam reformer catalytic reactor, and a heat exchanger are illustrated in FIG. 2, which is one embodiment of the present invention. The hydrogen generating apparatus 9 is composed of a combustion chamber 52 that is surrounded by insulation 51 , a burner 35 , a U-tube shaped steam reforming catalytic reaction vessel 8 , and a double pipe heat exchanger 53 . The mixture of hydrocarbon and steam enter U-tube shaped steam reforming catalytic reaction vessel 8 through means 7 and are heated in double pipe heat exchanger 53 , pass through a fixed bed of steam reforming catalyst where the hydrocarbon and steam are converted to carbon monoxide and water. The steam reformer product gases exit the U-tube shaped steam reforming reactor vessel through means 10 . The endothermic heat required by the steam reforming reaction is provided by heat delivered from burner 35 by burning a mixture of hydrocarbon, anode off-gas, and air in combustion chamber 52 . The mixture of combustion gas products passes through double pipe heat exchanger 52 , transferring heat to the incoming mixture of hydrocarbon and steam and subsequently exits through means 36 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] In a preferred embodiment, the combustion chamber 52 has an internal diameter of 12 inches and an internal length of 18 inches. Each side of the U-tube shaped steam reforming reaction vessel has a length of 23 inches, measured from the exterior of the hydrogen generating apparatus 9 to the point of maximum radius of the U portion of the U-tube. The U-tube shaped steam-reforming vessel is fabricated from a 2 inch 310 stainless steel schedule 40 pipe. A thickness of 5 inches of insulation surrounds the combustion chamber. The outer pipe of the double pipe heat exchanger is fabricated from 3 inch 304 stainless steel tubing having a {fraction (1/8)} inch wall thickness. The burner is a conical shaped burner commercially available from Acotech.
[0025] The equipment used in the single vessel heat integrated multi-stage water-gas shift reactor, including two water gas shift reactors, and a means of exchanging heat with a multi-functional heat exchanger are illustrated in FIG. 3, which is one embodiment of the present invention. The reformer product gas mixture enters the single vessel heat integrated multi-stage water-gas shift reactor 12 through inlet means 11 and passes through the fixed bed of high temperature water-gas shift catalyst 61 , and exits through exit means 13 to pass to the multi-functional heat exchanger and return through entrance means 18 to flow through the fixed bed of low temperature water-gas shift catalyst 63 and exit through exit means 19 . Port 62 of the single vessel heat integrated multi-stage water-gas shift reactor 12 is used to replace the low temperature water-gas shift catalyst 63 when required.
[0026] Description of the Preferred Embodiment
[0027] In a preferred embodiment, the water-gas shift reaction vessel was fabricated from 4 inch 304 stainless steel schedule 40 piping. The length of the vessel was 28 inches. The inlet to the fixed bed of high temperature water-gas shift catalyst was located at the upper end of the vessel. A solid bulkhead plate was welded to form a gas tight seal at the center of the vessel. An outlet from the fixed bed of high temperature water-gas shift catalyst fabricated from {fraction (1/2)} inch 304 stainless steel piping was centered 1¼ inches above the center line of the vessel. An inlet to the fixed bed of low temperature water-gas shift catalyst fabricated from {fraction (1/2)} inch 304 stainless steel piping was centered 1½ inches below the center line of the vessel. The outlet from the fixed bed of low temperature water-gas shift catalyst was located at the bottom end of the vessel.
[0028] The equipment used in the multiple heat source boiler, including a means of exchanging heat with a multi-functional heat exchanger, a means of receiving heat from the multi-functional heat exchanger, and a means of exchanger heat with the single vessel heat integrated multi-stage water-gas shift reactor are illustrated in FIG. 4, which is one embodiment of the present invention. Boiler feed water enters the multiple heat source boiler through inlet means 71 , receives heat to change its phase into steam and exits through exit means 5 . Heat is provided to the multiple heat source boiler 20 by the product process gas from the single vessel heat integrated multi-stage water-gas shift reactor 19 which flows through a first bank of 10 tubes 72 and exits through exit means 21 . A second means of receiving heat is from the combustion product gas from the combustion chamber 36 that flows through a second bank of 42 heat exchange tubes 73 and exits through exit means 37 . The third means of providing heat to the multiple heat source boiler, 20 is by re-circulating water 16 from boiler 20 to the multi-functional heat exchanger and receiving this stream returned in the form of a water-vapor mixture through inlet means 17 .
[0029] Description of the Preferred Embodiment
[0030] In a preferred embodiment the multiple heat source boiler was a unique shell and tube heat exchanger fabricated from 10 inch 304 stainless steel piping. It had a length of 19 inches. A partial tube sheet was located 2½ inches from the end of the boiler at which the combustion gas mixture entered. Another partial tube sheet was located 3 inches from the end at which it exited. The headspace at each end where gases entered and exited various tubes was divided into two different sections. One of the sections contained 10 tubes through which the process gas flowed. The other headspace section contained 42 tubes through which the combustion gas mixture flowed. All of the tubes were {fraction (1/2)} inch 304 stainless steel set on ⅝ inch triangular pitch. The space on the exterior of the tubes was filled with the water that was being heated to form steam.
[0031] The equipment used in the multi-functional heat exchanger having a means of exchanging heat with the multiple heat source boiler, a means of exchanger heat with the single vessel heat integrated multi-stage water-gas shift reactor, and a means of receiving heat from an electrical device are illustrated in FIG. 5, which is one embodiment of the present invention. The exit stream from the fixed bed of the high temperature water-gas shift catalyst in the single vessel heat integrated multi-stage water-gas shift reactor enters the multi-functional heat exchanger 14 through inlet means 13 passes through heat exchange tube 81 and exits through exit means 18 . The re-circulated water from the multiple heat source boiler enters through inlet means 16 passes through the shell side of the tubes in multi-functional heat exchanger 14 and exits through exit means 17 as a water-vapor mixture to return to the multiple heat source boiler. The third means of providing heat to the multi-functional heat exchanger 14 is from an electrical heating device such as an immersion electrical heater that is connected to the multi-functional heat exchanger 14 through connection 15 .
[0032] Description of the Preferred Embodiment
[0033] In a preferred embodiment the multi-functional heat exchanger was fabricated from 3 inch 304 stainless steel schedule 40 piping having a length of 16 inches. 304 stainless steel piping, in the form of a U enters and leaves the top of the vessel. This piping is connected to the water-gas shift reaction vessel. {fraction (1/2)} inch fine National Pipe Thread fittings are used on the side of the heat exchanger to make connections with the water recirculated to and from the multiple heat source boiler. A 1 inch fine National Pipe Thread connection at the bottom of the vessel is used to connect the electrical immersion water heater.
[0034] The equipment used in the single vessel water exchanged multi-staged preferential oxidation reactor is illustrated in FIG. 6, which is one embodiment of the present invention. The diagram in FIG. 6 shows an embodiment that is a preferential oxidation reactor of two stages. The product process gas mixed with air enters a first stage through inlet means 25 , and flows through a first bank of parallel tubes, 92 , each of which contains a fixed bed of preferential oxidation catalyst. The exit gas from said first stage is combined with an additional amount of air entering through inlet means 93 to form a feed mixture to a second stage 94 , of the single vessel water heat exchanged multi-stage preferential oxidation reactor 28 , which is comprised of a second bank of parallel tubes each of which contains a fixed bed of preferential oxidation catalyst. The water used to maintain the appropriate controlled temperature within the single vessel water heat exchanged multi-stage preferential oxidation reactor, and particularly to remove the exothermic heat of the preferential oxidation reactor enters at inlet means 29 and exits at outlet means 30 . The water for maintaining the appropriate temperature is typically the cooling water that has exited from the fuel cell stack. The carbon monoxide content of the product process gas entering at inlet means 25 is typically 0.3 to 1.0 percent whereas the carbon monoxide content of the hydrogen containing fuel cell stack feedstock exiting at exit means 95 is typically less than 10 parts per million.
[0035] Description of the Preferred Embodiment
[0036] In a preferred embodiment the single vessel water exchanged multi-staged preferential oxidation reactor is fabricated from 5 inch 304 stainless steel schedule 40 piping, having a length of 24 inches. Tube sheets were located 3 inches from each end of the preferential oxidation reactor. Nine ⅝ inch tubes fabricated from 304 stainless steel on a ⅞ inch triangular pitch occupied one half of the cross-sectional area of the reactor and were filled with preferential oxidation catalyst to form the first stage. The inlet to the headspace for the tube sheet was a {fraction (3/4)} inch fine National Pipe Thread fitting located at the top of the vessel. The outlets of the nine tubes were connected to a headspace at the bottom of the reactor from which {fraction (1/2)} inch stainless steel tubing in the shape of a U formed the outlet from the first stage and the inlet to the second stage. A {fraction (1/4)} inch tube was the connection used to add the second stage air to the U shaped tube connecting the first stage outlet to the second stage inlet. The second stage tubes were identical to the first stage tubes. The outlets from the nine second-stage tubes were connected to a headspace at the top of the reactor. A {fraction (3/4)} inch fine National Pipe Thread fitting was the outlet from the second-stage headspace.
[0037] Although only specific embodiments of the present invention have been described, numerous variations can be made in these embodiments without departing from the spirit of the invention, and all such variations that fall within the scope of the appended claims are intended to be embraced thereby.
[0038] The foregoing disclosure of this invention is not considered to be limiting since variations can be made by those skilled in the art without departing from the scope and spirit of the appended claims. | A fuel processor including a hydrogen generating apparatus, a single vessel heat-integrated multi-stage water-gas shift reactor, a multifunctional heat exchanger, a multiple heat source boiler, and a single vessel water exchanged multi-staged preferential oxidation reactor is integrated with a fuel cell stack. Hydrogen is manufactured by the fuel processing apparatus and is consumed by the fuel cell stack, thereby providing one means of integration. The portion of the hydrogen that is not utilized within the fuel cell stack is subsequently burned in the combustion chamber of the fuel processing apparatus thereby providing a second means of integration. The warm cooling water that exits from the fuel cell stack is used as a heat sink for the exothermic heat of reaction in the preferential oxidation reactor, thereby providing a third means of integration. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to an improvement of an automatic focusing camera and more particularly to an improvement of an automatic focusing camera equipped with a self-timer.
The automatic focusing camera capable of automatically focusing the photograph taking lens, or simply the taking lens by detecting the distance between the camera and an object and generating an electric signal to set the taking lens at a focus position has been widely accepted by photographers owing to its intrinsic ease of operation. However, the conventional automatic focusing cameras have problems in taking a photograph of the photographer himself using a self-timer. In a camera which focuses the taking lense at the moment when the self-timer is started, the range will be incorrectly set if the photographer starts the self-timer standing immediately in front of or behind the camera, while in a camera which focuses the taking lens after the self-timer has been started, the object may not be within the focus detecting area so that the taking lens will be incorrectly focused.
Accordingly, an object of the present invention is to provide a system which will allow manual focusing in photographing using a self-timer by locking the shutter once when the self-timer is set, then cancelling the locking of the shutter when the automatic focusing is cancelled.
BRIEF DESCRIPTION OF THE DRAWING
The attached drawing is a schematic illustration of the essential part of the mechanism according to the present invention as adjusted in the charged state with the self-timer not in use. Reference numerals designate; 1 . . . release plate, 2 . . . setting plate.
DETAILED DESCRIPTION OF THE INVENTION
Detailed explanation will be made hereinafter referring to the drawing. A release plate 1 having a projection 1d and an interlocking pin 1e is slidably guided by pins 1a fitted in slots 1b and restrained against a spring 1c.
A setting plate 2, only a part of it is shown, is adapted to move leftward from the charged position as shown in the drawing in focusing operation.
A ring 3 having a projection 3b for engaging with the setting plate 2 and cam part 3c formed of cams A, B, C, D and E is rotative together with the taking lens about the optical axis and urged counterclockwise by a spring 3a.
An adjusting lever 4 having a bend 4b for engaging with the cam part 3c, ratchet teeth 4c and an operating arm 4d is rotative about a shaft 4a and interlocked with the interlocking pin 1e by a known means.
An armature lever 5 having a pawl 5b for engaging with the ratchet teeth 4c and a magnetic part 5c is rotative about a shaft 5a and urged clockwise by a spring 5d. In the charged state as shown in the drawing, the armature lever 5 is pressed against an electromagnet 6 against the spring 5d by a known means.
The coil 6a of the electromagnet 6 is connected to a focus detecting electronic circuit 7 which supplies electricity to the coil 6a after the interlocking pin 1e has started and cuts off electricity when the focus is determined by the operation of the interlocking pin 1e.
A selecting member 8 having a bend 8b for engaging with the cam part 3c and an arm 8c for engaging with the operating arm 4d is rotative about a shaft 8a, urged counterclockwise by a spring 8d and stopped by a fixed pin 8e.
A locking member 9 having a shoulder part 9b for engaging with the projection 1d and projections 9c and 9d is rotative about a shaft 9a and urged counterclockwise by a weak spring 9e extending between the locking member 9 and the selecting member 8.
A self-timer 10 is set by turning a setting member 11 about a shaft 11a in the direction as shown by the arrow and delays shutter release for a desired period of time by known means. A projection 11b of the setting member 11 pushes the projection 9c against the spring 9e to retract the shoulder part 9b from the operating range of the projection 1d when the self-timer is not used.
A release lever 12 is rotative about a shaft 12a and adapted to actuate the shutter, not shown.
The manner of operation of the mechanism with the self-timer resting will be explained.
As the release plate 1 is depressed against the spring 1c interlocking with shutter release operation, the interlocking pin 1e actuates the focus detecting electronic circuit 7 to supply electricity to the coil 6a and to magnetize the electromagnet 6 so that the armature lever 5 is attracted to and held by the electromagnet 6, then the pressing of the armature lever 5 against the electromagnet is released by a known means, not shown, so that the armature lever 5 is controlled by the attraction of the electromagnet 6.
At the same time, the interlocking pin 1e turns the adjusting lever 4 counterclockwise about the shaft 4a, during which electricity supply to the coil 6a is cut off to unmagnetize the electromagnet 6 when a focus detection signal is generated so that the armature lever 5 is allowed to be turned clockwise about the shaft 5a by the spring 5d. Consequently, the pawl 5b engages with one of the ratchet teeth 4c to hold the bend 4b at a position to engage with one of the cams A, B, C, D and E corresponding to the focus position of the taking lens.
As the release plate 1 is depressed further, the release lever 12 is pushed with the bottom end of the release plate 1 and turned counterclockwise about the shaft 12a to start the shutter.
According to the operation of the shutter, the setting plate 2 travels leftward and is followed by the projection 3b so that the ring 3 is turned counterclockwise together with the taking lens by the spring 3a until the cam of the cam part 3c corresponding to the focus position of the taking lens is engaged with the bend 4b. Thus the ring 3, that is the taking lens, is adjusted to the focus position.
At the end of the operation of the setting plate 2, the shutter is released to perform exposure and the release plate 1 is returned to the starting position as shown in the drawing by the spring 1c.
In recharging the shutter, the setting plate 2 is moved rightward interlocking with the shutter charging operation pushing the ring 3 at the projection 3b against the spring 3a to turn the ring 3 clockwise and at the same time, turning the armature lever 5 counterclockwise against the spring 5d so that the magnetic part 5c is pressed against the electromagnet 6 thus completing the recharging operation as shown in the drawing.
When the self-timer is used, as the setting member 11 is turned clockwise about the shaft 11a, the locking member 9 is turned counterclockwise about the shaft 9a by the spring 9e as the projection 9c follows the projection 11b so that the shoulder part 9b is brought into the operating area of the projection 1d. The turning of the locking member 9 stops with the arm 9d against the arm 8c of the selecting member 8. In this state, the shoulder part 9d obstructs the operation of the release plate 1 by engaging with the projection 1d of the release plate 1.
Then, as the selecting member 8 is manually turned clockwise about the shaft 8a against the spring 8d, the arm 8c is engaged with the operating arm 4d to turn the adjusting lever 4 counterclockwise about the shaft 4a so that the bend 4b is retracted out of the operating range of the cam E of the cam part 3c while the bend 8b is introduced into the operating range of the cam D of the ring 3. The cam D corresponds to the common focus position of the taking lens.
Meanwhile, the arm 8c pushes the arm 9d to turn the locking member 9 clockwise so that the shoulder part 9b is retracted from the operating area of the projection 1d.
When the release plate 1 is depressed with the self-timer setting member 11 set at the self-timer operating position and the selecting member 8 set at the common focus position, the adjusting lever 4 will not be controlled by the focus signal generated from the electronic circuit 7 if the armature lever 5 is controlled by the electronic circuit 7 actuated by the interlocking pin 1e, because the adjusting lever 4 has previously been turned counterclockwise by the arm 8c of the selecting member 8 and the bend 4b has been retracted from the operating range of the cam part 3c. Therefore, the cam D corresponding to the common focus position of the taking lens engages with the bend 8b and the taking lens is adjusted to the common focus position when the setting plate 2 is actuated by the release lever 12 and the ring 3 is turned counterclockwise.
The operation of the setting plate 2 is delayed by the self-timer 10 through a means, not shown, near the end of the operation and allowed to move the final position after a fixed period of time to actuate the shutter thus completing the exposure, then the setting member 11 returns to the position as shown in the drawing.
In modification, the self-timer 10 may be constructed to allow the setting plate 2 to move a fixed period of time after the release lever 12 has been actuated.
Furthermore, although the selecting member 8 is provided with an action to cancel the automatic focusing function of the adjusting lever 4 and an action to restrain the cam part 3c at the position corresponding to the common focus position of the taking lens, the latter action may be developed into an action to adjust the cam part 3c to plural manually adjusted focus positions.
Still further, the selecting member 8 may be constructed to cancel the automatic focus detecting function of the electronic circuit 7 instead of a function of the arm 8c and to provide manual focus detecting function to the electronic circuit 7 instead of the bend 8b thus adjusting the adjusting lever 4 to a manually adjusted focus position.
According to the present invention, when the self-timer is used, the photographer is warned that the automatic focusing is not available by obstructing the shutter release operation and shutter release operation is possible by adjusting the mechanism to manual focusing setting. Thus the present invention is useful for the correct operation of the automatic focusing camera and for extending the availability of the automatic focusing camera. | An automatic focusing camera automatically determines the focus position of the taking lens by detecting the distance between the camera and an object and equipped with a self-timer setting system and a focusing system selector system which selects between automatic focusing and manual focusing.
A shutter locking member which normally locks the shutter interlocking with a setting operation of said self-timer setting system is released as said focusing system reflector system is set to manual focusing. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of co-pending U.S. patent application Ser. No. 09/826,070 filed on Apr. 4, 2001 entitled “Blades with Functional Balance Asymmetries for Use with Ultrasonic Surgical Instruments” and further claims the priority benefit of U.S. provisional patent application Ser. No. 60/412,845, filed on Sep. 23, 2002, both of which are incorporated by reference in their entirety herein.
FIELD OF THE INVENTION
[0002] The present invention relates to an ultrasonic surgical instrument for cutting, coagulating, grasping and blunt-dissecting tissue, and particularly relates to an ultrasonic surgical instrument having a port or lumen for providing fluid, vapor and/or debris management, such as, suction or irrigation to the surgical site. The present invention is, in one embodiment, specifically adapted for endoscopic surgery, although it has other medical applications as well.
BACKGROUND OF THE INVENTION
[0003] The prior art often features a suction system located at the distal end of an ultrasonic phacoemulsifier. This allows for suction/irrigation, but a problem exists in that the fluid suctioned or expelled from the ultrasonic phacoemulsifier is heated due to its direct contact with the ultrasonic blade. Fluids that come in direct contact with the ultrasonic blade cause a substantial heat reduction making the cauterization feature of the instrument less effective. The fluid in direct contact with the ultrasonic blade causes a decrease in the available transmitted ultrasonic energy, that is, the fluid dampens or loads the blade system requiring more input power to achieve the desired tissue effect. In addition, the tissue and/or fluids being transmitted through the blade cavity tend to accumulate at the nodes of the blade. This accumulation creates a blockage within the blade, which results in a reduced flow situation and even more power loss due to blade loading.
[0004] There is a need for an ultrasonic surgical device with suction and/or irrigation capabilities in which the suction/irrigation does not increase (due to, for example, loading of the blade system due to a collection of debris) or decrease (due to, for example, convective cooling) the heat emissions of the blade nor decrease the net power of the blade available to do work. A need is also present for an ultrasonic surgical device to effectively eliminate debris, which is known to collect at or near the nodes (longitudinal, torsional and/or transverse-modes or motion) of ultrasonic blades. In addition, a need is present to eliminate vapor from the ultrasonic transections to allow for increased visibility for the clinical user.
[0005] The present invention addresses the deficiencies of the prior art and provides an ultrasonic surgical instrument that is useful in both open and endoscopic surgical applications in addition to robotic-assisted surgeries.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention provides for an ultrasonic surgical device having a distally/proximally movable fluid management system consisting of single lumen or multiple lumens, which is positioned so as to minimally contact the ultrasonic blade. The invention provides for means of controlled delivery/removal of fluids, debris or vapor to and/or from the tissue effecting portion of the blade while minimizing the loading on the blade. The blades in the preferred embodiment are non-axisymmetric in at least one plane and have modal shapes at a given natural excitation frequency characterized by longitudinal, transverse, and/or torsional motion patterns where at least one nodal point along the tissue-effecting portion of the blade exists and is defined by a minimum (approximately zero) vibratory motion of the blade in a direction and at least one antinodal position exists along the tissue effecting portion (for example, at the distal tip) where the motion in the same direction is a maximum. This invention can also be used with axisymmetric blades that propagate vibratory motion in any of the aforementioned forms (longitudinal, transverse, and torsional) or combinations thereof wherein at least one motion nodal point is available for effecting tissue. The preferred instrument is designed to allow for the fluid management system to be positioned at one or more transverse (mode or motion) node to facilitate efficient removal of tissue or fluid, which tends to accumulate at such nodes of non-axisymmetric ultrasonic surgical blades.
[0007] It is known that during ultrasonic surgical procedures fluid and tissue accumulates at the nodes (longitudinal, transverse, and torsional-modes or motion). The present invention takes advantage of this phenomenon by utilizing a movable single lumen or movable multiple lumens, which may be placed for suction/irrigation at any of the nodes contained within the working portion of the end-effector. It may also be beneficial for the surgeon to have the ability to position the lumen/lumens anywhere along the working portion of the end-effector. Less suction is therefore required to remove the tissue or particles that have already accumulated near the nodal locations.
[0008] The present invention has the advantage of having the movable suction/irrigation lumen/lumens located away from the ultrasonic blade. In the prior art, instruments that have a suction system, an irrigation system, or both, in contact with the ultrasonic blade, have several disadvantages as earlier discussed. By locating the movable suction/irrigation lumen/lumens away from the blade, the coagulating temperature of the blade is not decreased and the unpredictable temperature increase of the blade that are due to tissue accumulation at the transverse (mode or motion) nodes of the blade are eliminated. In the present invention, the ultrasonic blades may also be solid as opposed to the necessary hollow blades seen in the prior art. This solid construction allows for better blade strength and allows more versatility of construction and shape.
[0009] The movable suction/irrigation lumen/lumens allows physicians to suction/irrigate at the most optimal location. Various blades will have different nodal (longitudinal, transverse, and torsional-mode or motion) locations due to the abundance of blade lengths, operating frequencies, materials, and geometry that affect the characteristic mode shape(s) of the blade that will be excited during use. A movable suction/irrigation lumen/lumens enables physicians to locate the suction/irrigation system at the desired location (nodal or otherwise), wherever that may be on a given blade.
[0010] The present invention also features the advantage of a channel located in the tissue-effecting portion of the ultrasonic blade. Fluid and tissue, which have a tendency to congregate at the nodal location, are more easily removed because the channel prevents collected particles from escaping from the suction device. The channel may also be used to direct irrigation fluid to the surgical site. Additionally, the channel may come in contact with the lumen/lumens in order to provide support or partially constrain the lumen. The channel may come in a variety of embodiments such as a spoon shape, wide curve, etc. The lumen may also be moved proximally in order to evacuate aerosol and/or vapor from the surgical site during the procedure.
[0011] The lumen/lumens may also be positioned to deliver irrigation through the device. Irrigation is, at times, beneficial to remove tissue and/or blood from the device when the blade is active. It is also beneficial to deliver irrigation to the surgical site in order to improve the visualization or clean the site in question. It makes sense that the lumen/lumens would be movable infinitely along the working portion of the end-effector. In the case of the surgical site irrigation, it may be beneficial to allow movement of the lumen/lumens beyond the distal tip of the blade.
BRIEF DESCRIPTION OF THE FIGURES
[0012] The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which:
[0013] FIG. 1 illustrates an ultrasonic surgical system including an elevation view of an ultrasonic generator, a sectioned plan view of an ultrasonic transducer, and a partially sectioned plan view of a clamp coagulator in accordance with the present invention;
[0014] FIG. 2 is a side view of an end-effector of the clamp coagulator with the clamp arm open;
[0015] FIG. 3 a is a bottom plan view of a blade of the clamp coagulator;
[0016] FIG. 3 b is a cross-sectional view of a blade of the clamp coagulator;
[0017] FIG. 3 c is a cross-sectional view of an alternate embodiment of a blade of the clamp coagulator;
[0018] FIG. 4 is a perspective view of an end-effector of the clamp coagulator.
[0019] FIG. 5 is a perspective view of one embodiment of a fluid management lumen for use with a clamp and curved blade ultrasonic end effector;
[0020] FIGS. 6 a - c are perspective views of a fluid management lumen in combination with alternate embodiments of ultrasonic blade end effectors;
[0021] FIGS. 7 a - b are perspective views of a fluid management lumen in combination with ultrasonic blade end effectors having channels;
[0022] FIG. 8 is a perspective view of an alternate embodiment of a blade and clamp in combination with a fluid management lumen; and
[0023] FIG. 9 a - e are elevation views of alternate ultrasonic blade designs for use with in combination with a fluid management lumen.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Before explaining the present invention in detail, it should be noted that the invention is not limited in its application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative embodiments of the invention may be implemented or incorporated in other embodiments, variations and modifications, and may be practiced or carried out in various ways. For example, the surgical instrument and blade configurations disclosed below are illustrative only and not meant to limit the scope or application of the invention. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative embodiments of the present invention for the convenience of the reader and are not for the purpose of limiting the invention.
[0025] Further, it is understood that any one or more of the following-described embodiments, expressions of embodiments, examples, methods, etc. can be combined with or are descriptive of any one or more of the other following-described embodiments, expressions of embodiments, examples, methods, etc.
[0026] The present invention is useful in combination with a blade only, a blade and a clamp, a shear configuration, or numerous other end-effectors. Examples of ultrasonic surgical instruments are disclosed in U.S. Pat. Nos. 5,322,055 and 5,954,736 and in combination with ultrasonic blades and surgical instruments as, for example, disclosed in U.S. Pat. Nos. 6,309,400 B2, 6,283,981 B1, and 6,325,811 B1 all of which are incorporated in their entirety by reference herein. These references disclose ultrasonic surgical instrument design and blade designs where a longitudinal mode of the blade is excited. Because of asymmetry or asymmetries, these blades exhibit transverse and/or torsional motion where the characteristic “wavelength” of this non-longitudinal motion is less than that of the general longitudinal motion of the blade and its extender portion. Therefore, the wave shape of the non-longitudinal motion will present nodal positions of transverse/torsional motion along the tissue effector while the net motion of the active blade along its tissue effector is non-zero (i.e. will have at least longitudinal motion along the length extending from its distal end, an antinode of longitudinal motion, to the first nodal position of longitudinal motion that is proximal to the tissue effector portion).
[0027] FIG. 1 illustrates ultrasonic system 10 comprising an ultrasonic signal generator 15 with ultrasonic transducer 82 , hand piece housing 20 , and clamp coagulator 120 in accordance with the present invention. Clamp coagulator 120 may be used for open or laparoscopic surgery. The ultrasonic transducer 82 , which is known as a “Langevin stack”, generally includes a transduction portion 90 , a first resonator or end-bell 92 , and a second resonator or fore-bell 94 , and ancillary components. The ultrasonic transducer 82 is preferably an integral number of one-half system wavelengths (nλ/2) in length as will be described in more detail later. An acoustic assembly 80 includes the ultrasonic transducer 82 , mount 36 , velocity transformer 64 and surface 95 .
[0028] The distal end of end-bell 92 is connected to the proximal end of transduction portion 90 , and the proximal end of fore-bell 94 is connected to the distal end of transduction portion 90 . Fore-bell 94 and end-bell 92 have a length determined by a number of variables, including the thickness of the transduction portion 90 , the density and modulus of elasticity of the material used to manufacture end-bell 92 and fore-bell 94 , and the resonant frequency of the ultrasonic transducer 82 . The fore-bell 94 may be tapered inwardly from its proximal end to its distal end to amplify the ultrasonic vibration amplitude as velocity transformer 64 , or alternately may have no amplification.
[0029] The piezoelectric elements 100 may be fabricated from any suitable material, such as, for example, lead zirconate-titanate, lead meta-niobate, lead titanate, or other piezoelectric crystal material. Each of the positive electrodes 96 , negative electrodes 98 , and piezoelectric elements 100 has a bore extending through the center. The positive and negative electrodes 96 and 98 are electrically coupled to wires 102 and 104 , respectively. Wires 102 and 104 are encased within cable 25 and electrically connectable to ultrasonic signal generator 15 of ultrasonic system 10 .
[0030] Ultrasonic transducer 82 of the acoustic assembly 80 converts the electrical signal from ultrasonic signal generator 15 into mechanical energy that results in primarily longitudinal vibratory motion of the ultrasonic transducer 82 and an end-effector 180 at ultrasonic frequencies. A suitable generator is available as model number GEN01, from Ethicon Endo-Surgery, Inc., Cincinnati, Ohio. When the acoustic assembly 80 is energized, a vibratory motion standing wave is generated through the acoustic assembly 80 . The amplitude of the vibratory motion at any point along the acoustic assembly 80 depends on the location along the acoustic assembly 80 at which the vibratory motion is measured. A minimum or zero crossing in the vibratory motion standing wave is generally referred to as a node (i.e., where motion is usually minimal), and an absolute value maximum or peak in the standing wave is generally referred to as an anti-node. The distance between an anti-node and its nearest node is one-quarter wavelength (λ/4).
[0031] Wires 102 and 104 transmit the electrical signal from the ultrasonic signal generator 15 to positive electrodes 96 and negative electrodes 98 . The piezoelectric elements 100 are energized by an electrical signal supplied from the ultrasonic signal generator 15 in response to a foot switch 118 to produce an acoustic standing wave in the acoustic assembly 80 . The electrical signal causes disturbances in the piezoelectric elements 100 in the form of repeated small displacements resulting in large compression forces within the material. The repeated small displacements cause the piezoelectric elements 100 to expand and contract in a continuous manner along the axis of the voltage gradient, producing longitudinal waves of ultrasonic energy. The ultrasonic energy is transmitted through the acoustic assembly 80 to the end-effector 180 .
[0032] In order for the acoustic assembly 80 to deliver energy to end-effector 180 , all components of acoustic assembly 80 must be acoustically coupled to the ultrasonically active portions of clamp coagulator 120 . The distal end of the ultrasonic transducer 82 may be acoustically coupled at surface 95 to the proximal end of an ultrasonic waveguide 179 by a threaded connection such as stud 50 .
[0033] The components of the acoustic assembly 80 are preferably acoustically tuned such that the length of any assembly is an integral number of one-half wavelengths (nλ/2), where the wavelength λ is the wavelength of a pre-selected or operating longitudinal vibration drive frequency f d of the acoustic assembly 80 , and where n is any positive integer. It is also contemplated that the acoustic assembly 80 may incorporate any suitable arrangement of acoustic elements.
[0034] The clamp coagulator 120 may include an instrument housing 130 , and an elongated member 150 . The elongated member 150 can be selectively rotated with respect to the instrument housing 130 . Located at the distal end of the outer tube 160 is an end-effector 180 for performing various tasks, such as, for example, grasping tissue, cutting tissue and the like.
[0035] End-effector 180 and its components are shown in greater detail in FIGS. 2 through 4 . The end-effector 180 generally includes a non-vibrating clamp arm assembly 300 to, for example, grip tissue or compress tissue against the ultrasonic blade 88 . The end-effector 180 is illustrated in FIGS. 2 and 4 in a clamp open position, and clamp arm assembly 300 is preferably pivotally attached to the distal end of the outer tube 160 . The damp arm 202 has tissue pad 208 with serrations 210 attached thereto for squeezing tissue between the ultrasonic blade 88 and clamp arm assembly 300 .
[0036] The distal end of the tubular member 174 of the inner tube 170 preferably includes a finger or flange 171 that extends therefrom. The flange 171 has an opening 173 A and an opening 173 B (not shown) to receive the first post 206 A and second post 206 B of the clamp arm 202 . When the inner tube 170 of the elongated member 150 is moved axially, the flange 171 moves forwardly or rearwardly while engaging the first post 206 A and second post 206 B of the clamp arm assembly 300 to open and close the clamp arm 202 .
[0037] The ultrasonic waveguide 179 of the elongated member 150 extends through aperture 175 of the inner tube 170 . The ultrasonic waveguide 179 is preferably substantially semi-flexible. It will be recognized that the ultrasonic waveguide 179 may be substantially rigid or may be a flexible wire. Ultrasonic vibrations are transmitted along the ultrasonic waveguide 179 in a longitudinal direction to vibrate the ultrasonic blade 88 .
[0038] The ultrasonic waveguide 179 may, for example, have a length substantially equal to an integral number of one-half system wavelengths (nλ/2). The ultrasonic waveguide 179 may be preferably fabricated from a solid core shaft constructed out of material that propagates ultrasonic energy efficiently, such as titanium alloy (i.e., Ti-6Al-4V) or an aluminum alloy. The ultrasonic waveguide 179 may also amplify the mechanical vibrations transmitted to the ultrasonic blade 88 as is well known in the art.
[0039] The ultrasonic blade 88 may have a length substantially equal to an integral multiple of one-half system wavelengths (nλ/2). The distal end of ultrasonic blade 88 may be disposed near an antinode in order to provide the maximum longitudinal excursion of the distal end. When the transducer assembly is energized, the distal end of the ultrasonic blade 88 is configured to move in the range of, for example, approximately 10 to 500 microns peak-to-peak, and preferably in the range of about 30 to 150 microns at a predetermined vibrational frequency.
[0040] The ultrasonic blade 88 is preferably made from a solid core shaft constructed of material which propagates ultrasonic energy, such as a titanium alloy (i.e., Ti-6Al-4V) or an aluminum alloy and can be of various geometries. As illustrated in FIGS. 3 a - c and 4 , the geometry of the ultrasonic blade 88 delivers ultrasonic power more uniformly to clamped tissue than predicate devices. The end-effector 180 provides for improved visibility of the blade tip so that a surgeon can verify that the blade 88 extends across the structure being cut or coagulated. This is especially important in verifying margins for large blood vessels. The geometry also provides for improved tissue access by more closely replicating the curvature of biological structures. Blade 88 provides a multitude of edges and surfaces, designed to provide a multitude of tissue effects: clamped coagulation, clamped cutting, grasping, back-cutting, dissection, spot coagulation, tip penetration and tip scoring.
[0041] The distal most tip of blade 88 has a surface 54 perpendicular to tangent 63 , a line tangent to the curvature at the distal tip. Two fillet-like features 61 A and 61 B are used to blend surfaces 51 , 52 and 54 , thus giving a blunt tip that can be utilized for spot coagulation. The top of the blade 88 is radiused and blunt, providing a broad edge, or surface 56 , for clamping tissues between it and clamp arm assembly 300 . Surface 56 is used for clamped cutting and coagulation as well as manipulating tissues while the blade is inactive.
[0042] The bottom surface has a spherical cut 53 that provides a narrow edge, or sharp edge 55 , along the bottom of blade 88 . The material cut is accomplished by, for example, sweeping a spherical end mill through an arc of radius R1 and then finishing the cut using a second, tighter radius R2 that blends the cut with a bottom surface 58 of the blade 88 . Radius R1 is preferably within the range of 0.5 inches to 2 inches, more preferably within the range of 0.9 inches to 1.1 inches, and most preferably about 1.068 inches. Radius R2 is preferably within the range of 0.125 inches to 0.5 inches, and most preferably about 0.25 inches. The second radius R2 and the corresponding blend with the bottom surface 58 of blade 88 diminishes the stress concentrated at the end of the spherical cut relative to stopping the cut without this blend. The sharp edge 55 facilitates dissection and unclamped cutting (back-cutting) through less vascular tissues.
[0043] Spherical cut 53 on bottom surface 58 of blade 88 creates sharp edge 55 while removing a minimal amount of material from blade 88 . Spherical cut 53 on the bottom of blade 88 creates a sharp edge 55 with an angle of α as described below. This angle α may be similar to predicate shears devices such as, for example, the LCS-K5 manufactured by Ethicon Endo-Surgery, Inc., Cincinnati, Ohio. However blade 88 cuts faster than predicate devices by virtue of the orientation of the angle α with respect to the typical application force. For the predicate shears devices, the edges are symmetric, spanning the application force equally. The edges for the present invention are asymmetric, with the asymmetry of the edges dictating how quickly tissue is separated or cut. The asymmetry is important in that it provides for an effectively sharper edge when ultrasonically activated, without removing a significant volume of material, while maintaining blunt geometry. This asymmetric angle as well as the curvature of the blade act to self tension tissue during back-cutting utilizing a slight hook-like or wedge-like action.
[0044] Sharp edge 55 of ultrasonic blade 88 is defined by the intersection of surface 53 and a second surface 57 left after bottom surface 58 has received spherical cut 53 . Clamp arm assembly 300 is pivotally mounted on said distal end of outer tube 160 for pivotal movement with respect to ultrasonic blade 88 , for clamping tissue between clamp arm assembly 300 and ultrasonic blade 88 . Reciprocal movement of inner tube 170 pivots clamp arm assembly 300 through an arc of movement, defining a vertical plane 181 . A tangent 60 of spherical cut 53 at sharp edge 55 defines an angle α with a tangent 62 of second surface 57 , as illustrated in FIG. 3 b . The bisection 59 of angle α preferably does not lie in vertical plane 181 , but is offset by an angle β. Preferably the tangent 60 of spherical cut 53 lies within about 5 to 50 degrees of vertical plane 181 , and most preferably the tangent of spherical cut 53 lies about 38.8 degrees from vertical plane 181 . Preferably angle α is within the range of about 90 to 150 degrees, and most preferably angle α is about 121.6 degrees.
[0045] Looking to FIG. 3 c , an alternate embodiment illustrated with an asymmetric narrow edge. A tangent 60 A of a spherical cut 53 A at a sharp edge 55 A defines an angle αA with a tangent 62 A of a second surface 57 A, as illustrated in FIG. 3 c . A bisection 59 A of angle αA preferably does not lie in a vertical plane 181 A, but is offset by an angle βA.
[0046] The curved shape of the design of ultrasonic blade 88 also results in a more uniformly distributed energy delivery to tissue as it is clamped against the blade 88 . Uniform energy delivery is desired so that a consistent tissue effect (thermal and transection effect) along the length of end-effector 180 is achieved. The distal most 15 millimeters of blade 88 is the working portion, used to achieve a tissue effect. As will be further described below, the displacement vectors for locations along the curved shears blade 88 have directions that, by virtue of the improvements of the present invention over predicate instruments, lie largely in the x-y plane illustrated in FIGS. 3 a - c . The motion, therefore, of blade 88 lies within a plane (the x-y plane) that is perpendicular to the direction of the clamping force from clamp arm assembly 300 .
[0047] Straight symmetric ultrasonic blades in general have tip excursions that lie along the longitudinal axis, designated the x-axis in FIGS. 3 a - c . Transverse motion is usually undesirable because it results in undesirable heat generation in inner tube 170 . When a functional asymmetry is added to an ultrasonic blade, such as a curved end-effector as described in U.S. patent application Ser. No. 09/106,686 incorporated herein by reference, the functional asymmetry creates an imbalance in the ultrasonic waveguide. If the imbalance is not corrected, then undesirable heat, noise, and compromised tissue effect occur. Although U.S. patent application Ser. No. 09/106,686 teaches how to provide ultrasonic blades that are balanced proximal to the balance asymmetry, the distal portion of the end-effector has an excursion in at least two axes. If the end-effector has a single plane of functional asymmetry, such as a curved end-effector, but the blade is otherwise symmetric, then the excursion will lie in a plane at the distal most end.
[0048] It is often desirable to minimize any ultrasonic blade 88 excursion in the z-axis direction. Excursion of ultrasonic blade 88 in the z-axis direction causes system inefficiencies, resulting in undesirable heating, power loss, and possibly noise. Excursion of ultrasonic blade 88 in the z-axis direction at end-effector 180 causes the ultrasonic blade 88 to impact tissue lying between ultrasonic blade 88 and clamp arm assembly 300 . It is desirable to limit ultrasonic blade 88 excursion to the x-y plane shown in FIGS. 3 a - c . This allows ultrasonic blade 88 to rub tissue lying between ultrasonic blade 88 and clamp arm assembly 300 without impact, which optimizes heating of the tissue, and thus provides optimal coagulation. Minimizing z-axis excursion both proximal to the end-effector 180 , and in ultrasonic blade 88 , may be accomplished by proper selection of a spherical cut 53 .
[0049] However, an ultrasonic end-effector 180 with an ultrasonic blade 88 that has multiple functional asymmetries, such as ultrasonic blade 88 as illustrated in FIGS. 3-4 , will naturally have a tendency to include tip excursion in all three axes, x, y, and z if not balanced properly. For example, ultrasonic blade 88 as illustrated in FIG. 3 a is curved in the y direction at its distal end. This curvature, although balanced proximal to end-effector 180 , will cause ultrasonic blade 88 to have excursions in both the x and y directions when activated. Adding spherical cut 53 subsequently adds another level of asymmetry to ultrasonic blade 88 , causing tip excursion in all three axes if not corrected, and also causing z-axis imbalances in ultrasonic waveguide 179 which decreases efficiency.
[0050] It is possible to minimize z-axis tip excursion proximal to the functional asymmetry, and therefore maximize efficiency with improved tissue effect, by providing a functional asymmetry optimized to minimize z-axis excursion in ultrasonic waveguide 179 . As illustrated in FIG. 3 , spherical cut 53 may extend proximally into ultrasonic blade 88 , from the most distal end, to any position. For example, FIG. 3 illustrates a first position 66 , a second position 67 , and a third position 68 , for spherical cut 53 to extend into ultrasonic blade 88 .
[0051] Table 1 below describes three possible lengths of spherical cuts 53 for ultrasonic blade 88 illustrated in FIG. 3 as first position 66 , second position 67 , and third position 68 . The rows of Table 1 correspond to the length of cut into the ultrasonic blade 88 , and the columns of Table 1 correspond to the balance condition and excursions along each axis for each cut length. It can be appreciated from Table 1 that providing spherical cut 53 to a length corresponding to first position 68 minimizes the z axis excursion proximal to the functional asymmetry. It is preferable to balance ultrasonic blade 88 below 15% z axis excursion proximal to the functional asymmetry and it is most preferable to balance ultrasonic blade 88 below 5% z axis excursion proximal to the functional asymmetry. Preferably damp coagulator 120 is designed to be balanced when activated in air (loaded only by air), and then balance is verified under other load conditions.
[0052] In Table 1, a normalized excursion percentage (% z) in a clamping instrument at the end-effector 88 is calculated by taking the magnitude of the excursion in the direction normal to the clamp arm when the clamp arm is in its fully closed position, and dividing that magnitude by the magnitude of the maximum tip vibration excursion (also called the primary tip vibration excursion), and then multiplying the dividend by one hundred. Primary tip vibration excursion is the magnitude of the major axis of the ellipse or ellipsoid created by a point on the distal most end of ultrasonic blade 88 when the ultrasonic blade 88 is activated. The measurement of excursions is more fully explained in IEC international standard 61847, titled Measurement and Declaration of the Basic Output Characteristics of ultrasonic surgical systems, hereby incorporated herein by reference. A normalized excursion percentage (%x, %y, %z) in ultrasonic blade 88 or ultrasonic waveguide 179 is calculated by taking the magnitude of a secondary vibration excursion, and dividing that magnitude by the magnitude of the primary tip vibration excursion, and then multiplying the dividend by one hundred. Secondary tip vibration excursion is the magnitude of a minor axis, or other arbitrary axis, of the ellipse or ellipsoid created by a point on the distal most end of ultrasonic blade 88 when the ultrasonic blade 88 is activated.
TABLE 1 Three possible lengths to provide a range of balances for a 0.946 inch long blade with a radius of R1 manufactured from Ti6AI4V with the blade including a functional asymmetry. % x at distal % y at distal % z at distal end of blade end of blade end of blade % z proximal 88 88 88 to blade 88 Cut Length = 71.83 69.47 4.15 0.40 12.8 mm, Location at first position 68 Cut Length = 72.49 68.87 1.60 12.43 14.8 mm Location at second position 67 Cut Length = 74.54 66.03 9.21 8.25 8.2 mm, Location at third position 66
[0053] FIG. 5 discloses the ultrasonic end effector 180 , featuring a lumen 9 , which permits irrigation/suction during surgical procedures. Lumen 9 may consist of a single tube with a single lumen, several tubes or a single tube with multiple lumens. Additionally, the lumen or lumens may have cross-sectional shapes selected from many manufacturable designs including, but not limited to, round, half round, partial round, rectangular, pyramidal, etc. Lumen 9 may be extendable/retractable with respect to blade 6 . In the preferred embodiment, lumen 9 is extended or retracted to a nodal (longitudinal, transverse, or torsional-mode or motion) position 7 or any other desirable position along a representative blade 6 . There are many variations in blade 6 shape and length such as a spoon shape, a blade 6 with a dramatic curve, a blade 6 with a flat curve, etc. These embodiments of ultrasonic surgical device 14 alter the location of the nodal positions 7 , at times creating several nodal locations 7 along the blade 6 . These particular examples are designed to be excited at a frequency corresponding to a longitudinal mode, but they will have non-longitudinal motion (i.e. transverse motion) occurring in a wave pattern with associated non-longitudinal nodes present at one or more location along the tissue effecting portion. The lumen 9 is extendable/retractable to allow the terminus of lumen 9 to be positioned at one of the transverse nodal positions 7 . The lumen 9 is retractable/extendable by several means, including manual extension, gear extension, trigger extension and by other means of mechanical actuation that may be located at the proximal end of surgical device 14 , as is well known to those skilled in the design of medical instruments. The method of creating suction/irrigation through lumen 9 may be done through a variety of means such as by attaching lumen 9 to a stand alone suction/irrigation module, tower mounted suction 200 and/or irrigation 202 modules ( FIG. 1 ), or an integrated ultrasonic generator/suction/irrigation module in the operating room. It may also be advantageous to integrate suction/irrigation controls (i.e. trumpet valves, etc.) and a means for selecting either suction or irrigation within the device handle.
[0054] In the preferred embodiment, lumen 9 is located on the concave side of blade 6 , though placement of the lumen 9 around the blade may vary depending on the needs of the physician, blade shape and/or acoustic characteristics. Lumen 9 may be made of numerous materials, though the material of the lumen 9 in the preferred embodiment is polymeric in nature. Examples of lumen materials include but are not limited to the following: FEP (fluorinated ethylene-propylene), PTFE (polytetrafluoroethylene), polyimide, nylon, PET (polyethylene terephthalate), PFA (perfluoroalkoxy), PVDA (polyvinylidene acetate), ETFE (ethylene tetrofluoroethylene), and polyethylene (high and low density). In the preferred embodiment, lumen 9 is fitted down an inner actuating tube 15 alongside the blade, held away from the blade by a series of silastic or polymeric stand-offs (not shown). Other embodiments may include the lumen 9 being fit between the blade and a tube (in the case of a blade-only configuration) an inner 15 and outer tube 160 (in the case of either shears or blade-only configurations), integrated into the tube, or alternatively, along the outside of a single support outer tube 160 . The lumen 9 is also extendable/retractable along the entire length 11 of the blade 6 , though the preferred location of the lumen 9 termination during surgical procedures is at or just proximal to a nodal position 7 for suction removal of fluids and/or debris, beyond the distal terminus of the end-effector for irrigation, and at the proximal terminus of the end-effector for suction removal of vapor and/or aerosol.
[0055] FIGS. 6 a - c disclose several alternate embodiments of the blade 6 . FIG. 6 a discloses a blade 6 having a spoon shape. The spoon shape of blade 6 creates a concave surface or channel 110 within the curvature of blade 6 . Channel 110 allows for particles to collect at a nodal position 7 preventing the particles from escaping from the blade 6 . The lumen 9 , preferably located at or just proximal to a transverse motion nodal position 7 , suctions the particles out of channel 10 . FIGS. 2 b and 2 c illustrate a dramatic curve of blade 6 and a wide, spatula-like blade 6 , respectively. Blade 6 may also be made out of numerous materials such as, but not limited to, titanium, aluminum, Stellite or ceramics.
[0056] FIGS. 7 a and b illustrates two alternate embodiments for a cavity or channel 110 , which may or may not be present in ultrasonic surgical instrument 14 depending on the needs of the physician. FIG. 7 a discloses a curved blade 6 featuring a curved channel 110 that terminates at the distal end of blade 6 . FIG. 7 b illustrates a second embodiment of channel 110 incorporated into a straight blade 6 . Channel 110 may have numerous embodiments such as a spoon-like appearance, a curved shape, a straight shape, sharp knife edges, etc. Channel 110 may also have a wide variety of lengths, widths and depths from blade to blade or channel 110 may have varying widths and depths along the length of a blade. Further, channel 110 may take on other forms such as a V-groove or square channel. This channel may be designed such that it provides support or constraint for the lumen/lumens.
[0057] FIG. 8 illustrates one embodiment of an ultrasonic shears device 14 in which the lumen 9 is present. In this alternate embodiment, the area for spot coagulation/cavitation 12 is disclosed, as well as the preferred area for a possible clamping surface 13 . If used with a clamping device, clamping surface 13 is the preferred area for clamp coagulation and cutting, though the area is not limited to this position. FIG. 8 also illustrates the possible distal/proximal extension/retraction movements lumen 9 may make in relation to the blade 6 .
[0058] FIGS. 9 a - e discloses numerous cross-sectional embodiments of the blade 6 and the channel 110 a - e.
[0059] While the present invention has been illustrated by description of several embodiments, it is not the intention of the applicant to restrict or limit the spirit and scope of the appended claims to such detail. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the scope of the invention. Moreover, the structure of each element associated with the present invention can be alternatively described as a means for providing the function performed by the element. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims. | Disclosed is an ultrasonic surgical device having a distally/proximally movable fluid management system consisting of single lumen or multiple lumens. The invention provides for the delivery of irrigation fluid or the removal of fluid, debris or vapor from the tissue-effecting portion of the blade while minimizing the loading on the blade. The blades of the surgical device, when excited at a natural blade system frequency, will have modal shapes characterized by longitudinal, transverse and/or torsional motion and will have nodal locations for these motions at positions along the tissue effecting length of the blade. The instrument is designed to allow for the fluid management system to be positioned at one or more motion nodes to facilitate efficient removal of tissue or fluid, which tends to accumulate at such nodes of the ultrasonic surgical blades. | 0 |
FIELD OF THE INVENTION
The present invention pertains to the controls for measuring fluid flow consumption, and, more particularly, to an improved system for controlling the flow of natural gas in a natural gas measuring and transfer station.
BACKGROUND OF THE INVENTION
Many natural gas distribution companies purchase natural gas from gas transmission companies at designated purchase stations, where the amount of natural gas being sold is measured. The natural gas at these purchase stations is heated, measured and reduced in pressure.
Until the late 1970s, archaic orifice meters were used to measure the amount of the gas being transferred from transmission and distribution points. Most of the transfer stations maintained multiple orifice meter runs (supply lines) arranged in parallel. Parallel meter runs were necessary in order to obtain accurate measurements of the gas flow with respect to the measuring instruments' water column range of 0 to 100 inches of water. The measurement was found to be most accurate in the 50-inch (or, the mid-range of differential pressure) measurement. Therefore, gas flowing at 85 inches of water through a primary line, for example, was diverted through a parallel, secondary line. This adjusted the differential pressure in each of the primary and secondary lines to 40 inches of water (the mid-range of the water columns), and avoided exceeding the upper measurement limits of the instruments.
The transmission companies using these multiple run systems typically utilize a constant bleed pneumatic limit flow controller to activate the parallel orifice meter runs
In the late 1970s, the use of liquefied natural gas prompted the transmission companies to install sophisticated electronic measuring devices in order to bill their customers for the amount of energy being transferred in each line, rather than measuring the volume of the flowing fluid.
Today, despite the capability for electronic control and measurement of natural gas at each purchase station, the transfer companies are still using the old-fashioned limit flow control equipment for gaseous natural gas transmission.
In order to regulate the gaseous flow between runs, the current constant bleed pneumatic controllers needlessly waste approximately 1,437 standard cubic feet of natural gas each day that they are in operation, i.e., when both runs are allowing gas to flow therethrough. This mode of operation is most prevalent in the winter months, when there is a greater demand for heating fuels. Although only small amounts of gas are being vented, it has been determined that the cumulative costs are great.
The present invention is a system for replacing the constant bleed pneumatic controllers for these transfer stations, thus providing the means by which substantial savings in fuel and money can be realized.
DISCUSSION OF RELATED ART
In U.S. Pat. No. 3,555,901, issued to Delatorre et al on Jan. 19, 1971, for "Method of and Apparatus for Measuring Varying Fluid Flow", a dual-metered line is illustrated having a fluid flow computer which governs the switchover controls. As the flow rate is measured, the fluid, in response thereto, is directed into the alternate line.
The aforementioned system differs from the present invention in that Delatorre et al require a computer to control the flow, and the flow rate in the line must be calculated. The present invention is far less complex, and its cost is minimal. The differential transducer used by the present invention already exists on site at each transfer station. The circuitry of the invention requires only one solenoid valve to do the switching between the runs, instead of the three solenoid valves of the aforementioned patented system.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a system for actuating additional fluid flow lines at a transfer station, without the venting or bleeding of fluid. The transfer station operates its supply lines, or runs, at differential pressures, usually ranging from 15 to 85 inches of water. It is desirable to maintain differential pressure in the primary line, or in the combination of primary and secondary lines at mid-range, of about 50 inches of water. The system of the invention entails replacing the existing constant bleed pneumatic controller with an electromechanical no-bleed control circuit. The circuit of the system includes a differential pressure transducer that provides an electrical signal that indicates the pressure drop across the supply lines. The differential pressure transducer controls a three-way, no-bleed, solenoid control valve that is designed to be ordinarily in the closed position, with the exhaust port open to the atmosphere. This control valve operates in the inventive system with the second fluid flow run in a position that is usually open. This is necessary; if the supply line were closed during a power loss, an excessive pressure drop would result in a shortage of supply. In addition, if this line were indeed closed, a pressure drop greater than 100 inches of water would not be measurable; hence, fluid would be supplied without an accounting thereof.
As fluid flows through the supply line and across the orifice plates of the dual-run system, the differential pressure transducer (which is tapped across the orifice plate in the primary run) measures the pressure drop. An electrical signal is generated that is indicative of this pressure drop. The signal is transmitted to a switching relay. When the upper or lower pressure limits in the primary line are reached, the generated signal will cause the relay to respectively activate or deactivate the three-way, no-bleed, solenoid valve. This will, in turn, allow fluid to flow not only through the primary run, but through both the primary and the secondary runs.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the present invention may be obtained by reference to the accompanying drawings, considered in conjunction with the subsequent, detailed description, in which:
FIG. 1 illustrates a systematic diagram of a prior art purchase station fluid supply system; and
FIG. 2 depicts a schematic diagram of the circuitry of the invention, as applied to the purchase station shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Generally speaking, the invention seeks to eliminate the constant bleeding and venting of natural gas in a switching valve that controls the gas flowing through the lines of a purchase station. The bleeding of the gas has never posed a serious problem in the past, due to the very small amounts of waste. However, given this era of greater fuel conservation, these minimal amounts of waste have been shown to eventually accumulate to produce significant losses. The bleed valve of the purchase flow system has been replaced with a non-venting valve and a simplified control apparatus in order to conserve fuel and protect the environment.
Now referring to FIG. 1, a prior art natural gas flow system for a purchase station 10 is illustrated. The purchase station 10 comprises a main supply line 11 for incoming natural gas to be measured, as well as an outgoing, purchaser gas line 14. In order to accurately measure the gas being supplied to the user during high demand periods, it is necessary to divide the gas flow into two gas lines; primary run 12 and secondary run 22 are shown. This is distilled as a result of the measurement process. It has been found that greater measurement accuracy is obtained when measurement of the flow is conducted at mid-pressure range, or approximately 50 inches of water. Therefore, when demand in the primary line 12 approaches the upper measurement limit of 85 inches of water, the flow is switched; it is then carried by the additional secondary run 22, as well as by the primary run 12. In this manner, the flow in both lines will carry a differential pressure of 15.0 inches of water or greater. Similarly, when the pressure drops below 15 inches of water in both lines, it is advantageous to switch the flow back to just one line, i.e., the primary line 12.
Orifices 13 and 23 disposed in each run, 12 and 22 respectively, are set to a certain size. Gauges 15 and 16 respectively measure the differential pressure across each orifice. A bleed-type pressure valve 17 allows for the opening of flow through the secondary run 22 during peak demand periods.
In order to switch the gas flow without the venting or bleeding of natural gas during high demand periods, the present invention then eliminates the bleed-type switching valve 17. This bleed-type valve 17 is now replaced with a three-way, no-bleed, solenoid-actuated valve, which is actuated by the control circuit, shown in FIG. 2.
Referring to FIG. 2, a schematic of the control circuit 100 of this invention is illustrated. The natural gas flow (arrow 25) in the incoming supply line 11 is directed to the primary and secondary runs 12 and 22, respectively. Gas flows (arrows 30 and 31) respectively through runs 12 and 22 and passes across respective orifice plates 27 and 37. A differential pressure transducer 32, tapped across the orifice plate 27 of the primary run 12, measures the pressure drop. The differential pressure transducer 32 is manufactured by Honeywell. The transducer 32 will transmit a signal in the range of approximately between 4 and 20 ma, which is proportional to the corresponding pressure range of between 0 and 100 inches of water column drop across the orifice 27. The signal is directed along line 40 to an integrated control circuit 41. The three-way, solenoid valve 35 is of a type similar to that made by the Automatic Switch Company of Florham Park, N.J. (Catalog No. 83206184). When the solenoid is de-energized, port 1 is closed, and ports 2 and 3 are open. When the solenoid is energized, port 2 is closed, and ports 1 and 3 are open. Pressure from the inlet port 1 (15 psig) will be applied to the outlet port 3 in order to close the on-off valve 36 and restrict the flow in the secondary run. Loss of power results in no pressure being applied to the on-off valve 36. The on-off valve is a pressure-to-close valve and will remain open in this circumstance. When the pressure limit of 15 inches is sensed across orifice 27, the signal will correspond to 0.64 v, using a 100 ohm resistor. When the pressure limit of 85 inches is sensed across orifice 27, the signal will correspond to 1.76 v. A relay (not shown) which is part of circuit 41 is actuated by the respective transducer signals to open and close a three-way, no-bleed solenoid valve 35. The relay is a 9-volt, 18 m coil, 120 AC, 1 amp relay powered from a ±15-volt transformer. The three-way solenoid valve 35, manufactured by ASCO, controls the on-off valve 36 disposed in the secondary run 22 via line 38. A 24-volt transformer is used to power the transducer 32.
A high signal of 1.76 v from transducer 32, corresponding to 85 inches of water across orifice 27, will trigger the relay of circuit 41 to output a 0 psig signal to on-off valve 36. This will cause the on-off valve 36 to open the flow in the secondary run 22. A low signal of 0.64 v from transducer 32 will cause the on-off valve 36 to output a 15 psig signal and close or restrict the flow of the secondary run 22.
A flow computer 50, shown connected to transducer 32, can be used to process the signals being generated by the existing electronic measurement equipment in order to calculate the amount of energy transferred. The computer 50, per se, is not part of this invention.
The inventive circuitry herein is very simple, and it utilizes the transducer 32 already available at most purchase station sites for measuring natural gas. The cost of converting the available equipment is minimal, and the retrofitting of each purchase station is quickly amortized by the savings in conserved fuel.
Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
Having thus described the present invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims. | The present invention features a system for actuating additional fluid flow lines at a transfer station, without the continuous venting or bleeding of fluid. The transfer station operates its supply lines, or runs, at differential pressures ranging from 15 to 85 inches of water. It is desirable to maintain differential pressure in the primary line, or in the combination of primary and secondary lines at mid-range, at about 50 inches of water. The system of the invention entails replacing the existing constant bleed pneumatic controller with an electromechanical no-bleed controller. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to pumpable geopolymer formulations or suspensions, and their uses, in particular, for oil and/or gas industry applications.
DESCRIPTION OF THE PRIOR ART
[0002] Geopolymers are a novel class of materials that are formed by chemical dissolution and subsequent recondensation of various aluminosilicate oxides and silicates to form an amorphous three-dimensional framework structure. The term geopolymer was proposed and first used by J. Davidovits (Synthesis of new high-temperature geo-polymers for reinforced plastics/composites, SPE PACTEC' 79, Society of Plastics Engineers) in 1976 at the IUPAC International Symposium on Macromolecules held in Stockholm. Other terms have been used to describe materials synthesized utilizing a similar chemistry, such as alkali-activated cement, geocement, alkali-bonded ceramic, inorganic polymer, hydroceramic. In the following description, the term geopolymer will be used.
[0003] Geopolymers based on alumino-silicates are generally designated as poly(sialate), which is an abbreviation for poly(silicon-oxo-aluminate) or (—Si—O—Al—O—) n (with n being the degree of polymerization). The sialate network consists of SiO 4 and AlO 4 tetrahedra linked alternately by sharing all the oxygens, with Al 3+ and Si 4+ in IV-fold coordination with oxygen. Positive ions (Na + , K + , Li + , Ca 2+ , . . . ) must be present in the framework cavities to balance the charge of Al 3+ in IV-fold coordination.
[0004] The empirical formula of polysialates is: M n {—(SiO 2 ) z —AlO 2 } n , w H 2 O, wherein M is a cation such as potassium, sodium or calcium, n is a degree of polymerization and z is the atomic ratio Si/Al which may be 1, 2, 3 or more, until 35 as known today.
[0005] The three-dimensional network (3D) geopolymers are summarized in the table below.
[0000]
TABLE 1
Geopolymers chemical designation (wherein M is a cation such as
potassium, sodium or calcium, and n is a degree of polymerization)
Si/Al
ratio
Designation
Structure
Abbreviations
1
Poly(sialate)
M n (—Si—O—Al—O—) n
(M)-PS
2
Poly(sialate-siloxo)
M n (—Si—O—Al—O—Si—O) n
(M)-PSS
3
Poly(sialate-disiloxo)
M n (—Si—O—Al—O—Si—O—Si—O—) n
(M)-PSDS
[0006] The properties and application fields of geopolymers will depend principally on their chemical structure, and more particularly on the atomic ratio of silicon versus aluminum. Geopolymers have been investigated for use in a number of applications, including as cementing systems within the construction industry, as refractory materials, as coatings, as ceramic precursors and as encapsulants for hazardous and radioactive waste streams. Geopolymers are also referenced as rapid setting and hardening materials. Compared to conventional Portland cement, they typically exhibit superior hardness and chemical stability.
[0007] First step of geopolymer synthesis involves the suspension of solid raw materials, such as the above mentioned alumino-silicates, into a carrier fluid. The fluid-to-solid ratio of this suspension affects properties of the suspension, such as for example, its viscosity and hardening time, and the properties of the hardened material obtained from the same suspension. Adjustment of the viscosity of this geopolymeric suspension without altering the other properties is critical in many applications such as the homogeneous coating thickness, the molding of ceramics pieces or the placement of the cement in building structure or in well cementing.
[0008] Well cementing, in particular, implies the control of the viscosity of the suspension at various temperatures encountered by the fluid in order to achieve a good placement of the fluid, while the fluid-to-solid ratio affects other critical parameters of well cementing operation such as for example the density of the suspension, the permeability and the mechanical properties of the hardened material.
[0009] Different prior art documents disclose the use of geopolymer compositions in the construction industry. In particular U.S. Pat. No. 4,509,985 discloses a mineral polymer composition employed for the making of cast or molded products at room temperatures, or temperatures generally up to 120° C.; U.S. Pat. No. 4,859,367, U.S. Pat. No. 5,349,118 and U.S. Pat. No. 5,539,140 disclose a geopolymer for solidifying and storing waste material in order to provide the waste material with a high stability over a very long time, comparable to certain archeological materials, those waste materials can be dangerous and even potentially toxic for human beings and the natural environment; U.S. Pat. No. 5,356,579, U.S. Pat. No. 5,788,762, U.S. Pat. No. 5,626,665, U.S. Pat. No. 5,635,292 U.S. Pat. No. 5,637,412 and U.S. Pat. No. 5,788,762 disclose cementitious systems with enhanced compressive strengths or low density for construction applications. WO2005019130 highlights the problem of controlling the setting time of the geopolymer system in the construction industry.
[0010] More recently WO2008017414 A1 and WO2008017413 A1, describe the application of the geopolymers in the oilfield industry. These documents state that, besides rapid strength development required in construction application, cementing oilfield applications require the control of other properties such as the mixability, pumpability, stability, thickening and setting times for large temperature and density ranges of geopolymer slurries. They mention different routes to control the thickening time, such as the nature and/or the pH and/or the concentration of the activator and/or the concentration of the alkali metal silicate. Additives controlling the thickening and setting times, such as setting accelerators or retarders, are also described in these documents. More precisely, setting accelerators such as alkali metal, salt of lithium and lithium chloride, are mentioned.
[0011] Simple and modified carbohydrates are already used in the cementing industry, and, more particularly in well cementing operations. Simple carbohydrates such as sugar are used to delay the setting time of Portland-based slurries.
SUMMARY OF THE INVENTION
[0012] Considering the above, the present description aims at proposing a settable geopolymer composition comprising at least one additive that is capable of accelerating the thickening and the setting of geopolymeric suspensions, especially at ambient and low temperature.
[0013] According to a first aspect, embodiments concern the use of a carbohydrate-based compound as a setting accelerator in a pumpable geopolymeric suspension for oil and/or gas industry applications, said suspension further comprising an aluminosilicate source, a carrier fluid, and an activator.
[0014] Preferably, the aluminosilicate source is selected from the group consisting of clays, dehydrated clays, dehydrated kaolins, fly ashes, blast-furnace slags, natural and synthetic zeolites, feldspars, dehydrated feldspars, alumina and silica sols, aluminum silicate or silica ceramic products, and mixtures thereof.
[0015] Preferably, the carrier fluid is selected from the group consisting of fresh water, sea water, brines, re-cycled water or recuperated water, and mixtures thereof.
[0016] Preferably, the activator is a base. More preferably, it is a silicate, a metal aluminate, a alkali-metal hydroxide, ammonium hydroxide, a alkaline earth metal hydroxide, sodium carbonate or a mixture thereof.
[0017] According to embodiments, the carbohydrate-based compound is a monomer. According to a second embodiment, the carbohydrate-based compound is a dimer. According to a third embodiment, the carbohydrate-based compound is a polymer. Mixtures of monomers, dimers or polymers may be used.
[0018] The carbohydrate-based compound is, for example, a saccharide or a salt thereof. In another example, the carbohydrate-based compound is a saccharide derivative of a salt thereof.
[0019] Preferably, the concentration of the carbohydrate-based compound is from 0.03% to 15% by weight of aluminosilicate. More preferably, the concentration of the carbohydrate-based compound is from 0.05% to 10% by weight of aluminosilicate. More preferably, the concentration of the carbohydrate-based compound is from 0.05% to 5% by weight of aluminosilicate.
[0020] According to a further aspect, embodiments relate to methods of preparing and placing such a suspension, which includes a first step comprising either (i) predissolving the carbohydrate-based compound in the carrier fluid that can optionally contain pre-dissolved activator or (i′) blending the carbohydrate-based compound with the aluminosilicate source. It will be noted that the carbohydrate may, optionally, be admixed with the activator.
[0021] Preferably, the method according to the invention further comprises the steps of: (ii) pumping said suspension into the borehole, and (iii) allowing said suspension to set under wellbore downhole conditions and thereby to form the geopolymeric set material.
[0022] Preferably, the suspension is a pumpable composition in for use in the oil and gas industry and the suspension is able to set downhole, in an oil and/or gas well. Nevertheless, the invention may be implemented in injector wells, in particular, steam injector wells, geothermal wells, or for carbon capture and storage. More preferably, the suspension is used for performing well primary cementing operations or for remedial applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Other features and aspects will be apparent from the following description and the accompanying drawings, in which:
[0024] FIG. 1 illustrates the effect of the starch on the thickening time of geopolymer suspension at 40° C.; and
[0025] FIG. 2 illustrates the effect of glucose on the thickening time at a bottom hole circulating temperature of 25° C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Embodiments relate to uses of a carbohydrate-based compound as a setting accelerator in a pumpable geopolymeric suspension, and to a method of preparing and placing such suspension downhole. According to the invention, the suspension comprises an aluminosilicate source, a carrier fluid, an activator; a setting accelerator and, if appropriate, other additives.
[0027] Preferably, the aluminosilicate source is selected from the group consisting of: clays, dehydrated clays, dehydrated kaolins (metakaolin), fly ashes, blast-furnace slags, natural and synthetic zeolites, feldspars, dehydrated feldspars, alumina and silica sols, aluminum silicate and silica ceramic products (refractories, wares, catalytic supports, bricks, structural ceramics), or a mixture thereof. In this list, more preferable, aluminosilicate sources are selected from the group consisting of calcined clay such as metakaolin, ASTM class C and F fly ashes and granulated or pelletized blast-furnace slag.
[0028] In a further embodiment, the aluminosilicate component comprises a first aluminosilicate binder and optionally one or more secondary binder components which may be chosen in the list: ground granulated blast furnace slag, fly ash, Portland cement, kaolin, metakaolin, silica fume, bauxite, alumina oxide and hydroxide.
[0029] The carrier fluid is preferably an aqueous solution such as fresh water. In another embodiment, fresh water may be substituted by the sea water, brines or re-cycled or recuperated water.
[0030] The activator is generally an alkali. Among them, silicate, a metal aluminate, a alkali-metal hydroxide, ammonium hydroxide, a alkaline earth metal hydroxide, sodium carbonate or a combination thereof are preferred. It can be carbonate salts (such as sodium carbonate), or more preferably a metal silicate, a metal aluminate, certain soluble metal hydroxide, preferably alkali-metal hydroxide such as sodium hydroxide or potassium hydroxide or alkaline earth metal hydroxide such as Ca(OH) 2 ), and combinations thereof.
[0031] The setting accelerator comprises at least a carbohydrate-based compound to accelerate the thickening and the setting of the geopolymeric suspension, especially at ambient and low temperature, for example in the range of 20° C. to 85° C. The carbohydrate-based compound is either a monomer, such as glucose, a dimer, a polymer, such as starch, or a saccharide salt, such as carboxymethylcellulose. Saccharide derivatives, and their salts, may also be used as setting accelerators according to the invention. The concentration of the carbohydrate-based compound is preferably less than 15% by weight of aluminosilicate, more preferably less than 10%, more preferably less than 5%.
EXAMPLE 1
[0032] This example demonstrates the possibility to control the thickening time of the geopolymer suspensions by addition of starch. FIG. 1 illustrates the obtained effect.
[0033] A sample A1 was made by the subsequent addition of 167 g of 10 M solution of sodium hydroxide and the blend comprising 569 g of Fly ash class C, 53.5 g of sodium disilicate into 235 g of water. The prepared slurry is then placed into the pressurized consistometer and thickening time was measured according to ISO 10426-2 standard at a bottom hole circulating temperature of 40 ° C. according to API schedule 9.2 (recommended practice 10B, 1997).
[0034] A sample A2 was made by the pre-hydration of 4.8 g of modified starch Flotrol available from MI-SWACO in 235 g of water and subsequent addition into this solution of 161.3 g of 10 M solution of sodium hydroxide and the blend comprising 569 g of Fly ash class C, 53.5 g of sodium disilicate. The prepared slurry was then placed into the pressurized consistometer and thickening time was measured according to ISO 10426-2 standard at a bottom hole circulating temperature of 40° C. according to API schedule 9.2 (recommended practice 10B, 1997).
EXAMPLE 2
[0035] The following example demonstrates the accelerating effect of the water-soluble cellulose derivatives at 40° C.
[0036] A sample B1 was made by the subsequent addition of 167 g of 10 M solution of sodium hydroxide and, the blend comprising 569 g of Fly ash class C, 53.5 g of sodium disilicate into 235 g of water. The prepared slurry was then placed into the pressurized consistometer and thickening time was measured according to ISO 10426-2 standard at a bottom hole circulating temperature of 40° C. according to API schedule 9.2 (recommended practice 10B, 1997).
[0037] A sample B2 was made by the pre-dissolution of 6.3 g of low-viscosity carboxymethylcellulose in 235 g of water and subsequent addition into this solution of 167 g of 10 M solution of sodium hydroxide and the blend comprising 569 g of Fly ash class C, 53.5 g of sodium disilicate. The prepared slurry was then placed into the pressurized consistometer and thickening time measurements were performed according at a bottom hole circulating temperature of 40° C. according to API schedule 9.2. The results are shown in the Table 2 below.
[0000] TABLE 2 Possibility to accelerate geopolymer slurries with carboxymethylcellulose at 40° C. Sample B1 B2 Thickening time, 30 Bc Not reached 4:06 hh:mm during 16 h 70 Bc n.m 7:51 95 Bc n.m 7:57
n.m designates that the experiment was stopped and measurement was not taken because it took more than 16 h to achieve the consistency of 30 Bc (Bearden consistency).
[0038] The measurements are performed at a bottom hole circulating temperature of 40° C. according to API schedule 9.2.
EXAMPLE 3
[0039] In a further aspect, a saccharide-based compound can be used as accelerating agent to shorten the thickening and setting times of geopolymeric suspensions. As shown in FIG. 2 , an increasing concentration of glucose decreases the thickening time, as measured according to the ISO 10426-2 standard. These results illustrate that the mechanism involved during cement and geopolymer settings are completely different, sugar being known as retarder for cement compositions.
[0040] A sample C1 was prepared by adding the blend comprising 660 g of class C fly ash, 117 g of sodium disilicate and 6.6 g of glucose into 353 g of a solution made of water and 72 g of NaOH. The preparation was achieved according to ISO 10426-2 standard mixing procedure. Thickening time was measured according to ISO 10426-2 standard at a bottom hole circulating temperature of 25° C. according to API schedule 9.2 (recommended practice 10B, 1997).
[0041] A sample C2 was prepared by adding the blend comprising 660 g of class C fly ash, 117 g of sodium disilicate and 9.9 g of glucose into 351 g of a solution made of water and 72 g of NaOH. The preparation was achieved according to ISO 10426-2 standard mixing procedure. Thickening time was measured according to ISO 10426-2 standard at a bottom hole circulating temperature of 25° C. according to API schedule 9.2 (recommended practice 10B, 1997).
[0042] A sample C3 was prepared by adding the blend comprising 660 g of class C fly ash, 117 g of sodium disilicate and 13.2 g of glucose into 349 g of a solution made of water and 72 g of NaOH. The preparation was achieved according to ISO 10426-2 standard mixing procedure. Thickening time was measured according to ISO 10426-2 standard at a bottom hole circulating temperature of 25° C. according to API schedule 9.2 (recommended practice 10B, 1997). | The invention concerns the use of a carbohydrate-based compound as a setting accelerator in a pumpable geopolymeric suspension for oil and/or gas industry applications, said suspension further comprising ‘an aluminosilicate source, a carrier fluid, and an activator, and methods of preparing such suspensions. In particular, the suspension according to the invention is used for well primary cementing operations and/or remedial applications. | 4 |
FIELD OF THE INVENTION
The present invention relates to a base paper (raw paper), which can be made into various processed paper, such as the paper sheet of a textbook, the thin layer of a notebook or wrap paper, the flake structure of household paper or the base layer of office paper. The present invention also relates to a preparation method of the base paper.
BACKGROUND OF THE INVENTION
In the prior art, there exist the problems of stimulation to eyes caused by the whiteness of textbook, notebook and duplicating paper, and the use of a large number of chemicals resulting in environmental pollution.
No other dyes, pigments or dyeware are added into the base paper of the present invention. In most cases, the base paper is not bleached or just lightly bleached, and the resulting base paper per se has a natural yellow color which is beneficial to the vision, so as to achieve the purpose of protecting eyes and preventing myopia. At the same time, by employing 100% of the base paper, the damage of chemicals such as dioxin to humans can be avoided, that is to say, the base paper of the present application is environment-friendly.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a base paper;
Another object of the present invention is to provide a preparation method of the base paper.
A further object of the present invention is to provide the use of the base paper in paper production.
In order to achieve the objects mentioned above, the invention takes the following technical scheme:
A base paper, which is made from mixed pulp comprising straw pulp and industry pulp, wherein the weight percent of the straw pulp is 10-100 wt. % of the mixed pulp, preferably 30-90 wt. %, more preferably 40-80 wt. %; the straw pulp has a hardness with potassium permanganate value of 10-17, an average fiber length of 0.1-2.5 mm, a tensile index of 23-57 Nm/g, a tear index of 3.0-6.0 mN·m 2 /g, and a folding number of 2-6 kPa·m 2 /g; and the straw pulp has a whiteness of 28-50%, preferably 30-45%, more preferably 25-43%.
A method for preparing the base paper, wherein the method comprises: putting the grass material into a cooker, adding cooking liquor, and then heating the cooking liquor to 100-200°, increasing pressure to 0.3-0.9 MPa, keeping cooking for 150-250 minutes, and obtaining the straw pulp after pressing and washing; and in the cooking liquor, ammonium sulfite is used in an amount of 5-20% of bone dry raw material by weight, sodium hydroxide is used in an amount of 0-15% of the bone dry raw material by weight, and the liquor ratio is 1:2-15.
Preferably, the method comprises: putting the grass material into the cooker, adding cooking liquor, and then heating the cooking liquor to 156-173°, increasing pressure to 0.6-0.75 MPa, keeping cooking for 180-220 minutes, and obtaining the straw pulp after pressing and washing; and in the cooking liquor, ammonium sulfite is used in an amount of 9-15% of the bone dry raw material by weight, sodium hydroxide is used in an amount of 0-8% of the bone dry raw material by weight, and the liquor ratio is 1:6-10.
The method further comprises oxygen delignification after washing, which comprises: pumping the pulp after cooking or washing to an oxygen delignification reaction tower for a reaction of 60-90 minutes and obtaining the straw pulp, wherein, a temperature and a pressure of the pulp is respectively 90-100° and 0.9-1.2 MPa at the inlet of the reaction tower, and 95-105° and 0.2-0.4 MPa at the outlet; and the alkali used in the oxygen delignification is 2-4% of bone dry pulp based on sodium hydroxide, and oxygen is added in an amount of 20-40 kg per ton of bone dry pulp.
The method further comprises oxygen delignification, which comprises: 1) regulating concentration of high-hardness pulp which is obtained after cooking; 2) pumping the high-hardness pulp to an oxygen delignification reaction tower and adding sodium hydroxide and oxygen; 3) the high-hardness pulp being subjected to delignification reaction in the oxygen delignification reaction tower, wherein the concentration of high-hardness pulp refers to regulating the concentration of high-hardness pulp to 8-18%; the oxygen delignification is preferably single stage and carried out in the oxygen delignification reaction tower.
Preferably, during the oxygen delignification, a temperature and a pressure of the pulp is respectively 95-100° and 0.9-1.2 MPa at an inlet of the reaction tower, and 100-105° and 0.2-0.4 MPa at an outlet.
Alkali used in the oxygen delignification is 2-4% of bone dry pulp based on sodium hydroxide, oxygen is added in an amount of 20-40 kg per ton of bone dry pulp; and the straw pulp reacts in the reaction tower for 60-90 min.
Preferably, the pulp is heated to 70° and conveyed to a pulp pipe before the oxygen delignification.
Preferably, a magnesium salt is added in amount of 0.2-1% of the bone dry raw material by weight as a protective agent in the oxygen delignification.
Preferably, a bleacher is added in an amount of 1/10˜¼ the one of the prior art.
The invention has the following advantages:
(1) Textbook made from the base paper of the invention as material can form the yellow vision environment to people without adding other dyes, pigments or colorant, which achieves the purpose of protecting the eyes, prevention and treatment of myopia; (2) The straw pulp without bleaching in the invention avoids health threats caused by dioxins and other environmental problem; (3) Products made by the base paper are not added dye, pigment or colorant, and the straw pulp is not need to be bleached, which reduces the cost of manufacturing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The following embodiments further illustrates the technical solution of the present invention. It will contribute to understand the advantages and effect of the invention. The embodiments do not limit the scope of protection of the invention, and the scope of protection of the invention is decided by the claims.
Example 1
The present example relates to the preparation method of the straw pulp.
The straw pulp of the present example is obtained after cooking and washing, or obtained after cooking, washing and oxygen delignification.
The cooking of the invention can employ a common cooking method in the prior art, such as ammonium sulfite, sodium hydroxide, anthraquinone-sodium hydroxide, sulfate, or anthraquinone-alkali sodium sulfite cooking methods.
The method preferably comprises: putting the grass material into a cooker, adding cooking liquor to the cooker and heating to 100-200°, increasing pressure to 0.3-0.9 MPa, keeping cooking for 150-250 minutes, and obtaining the straw pulp after pressing and washing. Wherein, in the cooking liquor, the ammonium sulfite is used in an amount of 5-20% of the bone dry raw material by weight, the sodium hydroxide is used in an amount of 0-15% of the bone dry raw material by weight, and the liquor ratio is 1:2-15.
More preferably comprises: putting the grass material into a cooker, adding cooking liquor to the cooker and heating to 156-173°, increasing pressure to 0.6-0.75 MPa, keeping cooking for 180-220 minutes, and obtaining the straw pulp after pressing and washing. Wherein, in the cooking liquor, the ammonium sulfite is used in an amount of 9-15% of the bone dry raw material by weight, the sodium hydroxide is used in an amount of 0-8% of the bone dry raw material by weight, and liquor ratio is 1:6-10.
The oxygen delignification is carried out after washing to get the straw pulp of the invention, and the pulp is obtained.
The oxygen delignification of the present invention comprises: pumping the pulp after cooking or washing to an oxygen delignification reaction tower, in which the temperature and pressure of the pulp is respectively 90-100° and 0.9-1.2 MPa at an inlet of the reaction tower, and 95-105° and 0.2-0.6 MPa at an outlet.
Wherein, alkali is used in the oxygen delignification in an amount of 2-4% of bone dry pulp based on sodium hydroxide, and oxygen is added in an amount of 20-40 kg for every ton of bone dry pulp for keeping reaction for 60-90 min to obtain the straw pulp.
The straw pulp of the invention has a hardness with potassium permanganate number of 10-17, an average fiber length of 0.1-2.5 mm, a tensile index of 23-57 Nm/g, a tear index of 3.0-6.0 mN·m 2 /g, and a folding number of 2-6 kPa·m 2 /g.
The straw pulp of the invention has a whiteness of 28-50%, preferably 30-45%, more preferably 25-43%.
The straw pulp of the present example is obtained from one or more of wheat straw, rice straw, cotton stalk, giant reed and reed, preferably wheat straw and rice straw.
The example also relates to a mixture of pulp which contains other industrial paper pulp. The industrial paper pulp comprises one or more of bagasse pulp, wood pulp, cotton pulp, bamboo pulp or secondary fiber.
The secondary fiber is made from recycled waste paper pulp fibers.
The straw pulp has a weight ratio of 10-100% of the mixed pulp, preferably 30-90%, more preferably 40-80%.
Example 2
The present example relates to a straw pulp which is the same as that of example 1 except the following difference: the base paper is made from the straw pulp with content of 100% which has a hardness with potassium permanganate value of 10-17, an average fiber length of 0.1-2.5 mm, a tensile index of 23-57 Nm/g, a tear index of 3.0-6.0 mN·m 2 /g, a folding number of 2-6 kPa·m 2 /g.
The present example also relates to an anti-myopia base paper of textbooks which is made from the mixed pulp, wherein, the pages of textbooks with a whiteness of 40-76%, preferably 50˜76%, more preferably 60˜76% are made from straw pulp without adding dyes, pigments or colorant. Further, the pages have an opacity of 70˜100%, preferably 80˜99%, more preferably 85˜95%.
The present example also relates to a base paper of publications which is made from the mixed pulp, wherein, the base paper refers to the page here. The paper made from the mixed pulp without adding any dye, pigment or colorant has a whiteness of 40-76%, preferably 50˜76%, more preferably 60˜76%. Further, the page has an opacity of 70˜100%, preferably 80˜99%, more preferably 85˜95%.
Example 3
This example is the same as example 1, except that straw pulp fiber and wood pulp fiber obtained by following method are interweaved each other to form a network structure which makes the page multi porous, rough, has large area of optical joint surface and high opacity.
The preparation method and properties of writing paper are as follows: putting the straw into a cooker, adding cooking liquor to the cooker and heating to 165°, increasing pressure to 0.7 MPa, keeping cooking for 240 minutes, and obtaining the straw pulp after pressing and washing. Wherein, in the cooking liquor, ammonium sulfite is used in an amount of 15% of the bone dry raw material by weight, sodium hydroxide is used in an amount of 5% of the bone dry raw material by weight, and liquor ratio is 1:8. The straw pulp has a hardness with potassium permanganate value of 16, a tensile index of 28 Nm/g, a tear index of 3.9 mN·m 2 /g, a folding number of 3.4 kPa·m 2 /g, and a whiteness of 35%. The straw pulp and wood pulp are mixed to make the writing paper (base paper) with dirt count of 75/·m 2 per 0.3-1.5 mm 2 , opacity of 91%, whiteness of 51%.
The preparation method and properties of food wrap paper are as follows: putting the straw into a cooker, adding cooking liquor to the cooker and heating to 160°, increasing pressure to 0.65 MPa, keeping cooking for 200 minutes, and obtaining the straw pulp after pressing and washing. Wherein, in the cooking liquor, ammonium sulfite is used in an amount of 10% of the bone dry raw material by weight, sodium hydroxide is used in an amount of 5% of the bone dry raw material by weight, and liquor ratio is 1:8. The straw pulp has a hardness with potassium permanganate value of 16, a tensile index of 38 Nm/g, a tear index of 4.8 mN·m 2 /g, a folding number of 4.6 kPa·m 2 /g, a whiteness of 35%. The pulp is used to make the food wrap paper (base paper) with dirt count of 120/·m 2 per 0.3-2.0 mm 2 , bursting strength of 75 kPa, and whiteness of 28-60%.
The dirt count of the invention is measured by the testing method of national standard GB/T 1541-1989 (Paper and board-Determination of dirt).
Example 4
The straw pulp fiber of the invention is defined as the straw pulp fiber which is obtained by the method of the prior art, such as cooking and washing, or cooking, washing and oxygen delignification. The cooking of the invention comprises, but not limited to, ammonium sulfite and alkaline method. The alkaline method comprises anthraquinone-sodium hydroxide, sulfate or basic sodium sulfite cooking methods.
The preferable cooking method of the present example is as follows: putting the straw material into a cooker, adding cooking liquor to the cooker and then heating to 100-200°, increasing pressure to 0.3-0.9 MPa, and keeping cooking for 150-250 minutes, and obtaining the straw pulp after pressing and washing. Wherein, in the cooking liquor, ammonium sulfite is used in an amount of 5-20% of the bone dry raw material by weight, sodium hydroxide is used in an amount of 0-15% of the bone dry raw material by weight, and liquor ratio is 1:2-15.
An oxygen delignification can be carried out after cooking or washing, wherein the oxygen delignification comprises:
1) regulating concentration of high-hardness pulp obtained after cooking; 2) pumping the high-hardness pulp to an oxygen delignification reaction tower and adding sodium hydroxide and oxygen; 3) carrying out delignification reaction in the oxygen delignification reaction tower.
Wherein, the concentration of high-hardness pulp is regulated to 8-18%. In other words, the oxygen delignification is carried out under a high concentration.
Preferably, the oxygen delignification is single stage and executed in the oxygen delignification reaction tower, in which, the temperature and pressure of the pulp is respectively 95-100° and 0.9-1.2 MPa at an inlet of the reaction tower, and 100-105° and 0.2-0.4 MPa at an outlet.
Wherein, alkali used in the oxygen delignification treatment is 2-4% of bone dry pulp based on sodium hydroxide, and oxygen is added in an amount of 20-40 kg for every ton of bone dry pulp; and the straw pulp reacts in the reaction tower for 60-90 min.
Preferably, the pulp is heated to 70° and conveyed to a pulp pipe before the oxygen delignification.
Preferably, magnesium salt with amount of 0.2-1% of the bone dry raw material by weight is added as protective agent.
Preferably, high-hardness of the pulp obtained after the oxygen delignification is potassium permanganate value of 10-14, which is equivalent to 13-19.8 Kappa number, more preferably potassium permanganate value of 11-13, which is equivalent to 14.5-17.9 Kappa number.
The straw pulp of the present example is obtained from one or more of wheat straw, rice straw, cotton stalk, giant reed and reed, preferably wheat straw and rice straw.
The example also relates to a mixture of pulp which contains other industrial paper pulp, wherein the industrial paper pulp comprises one or more of bagasse pulp, wood pulp, cotton pulp, bamboo pulp or secondary fiber which is made from recycled waste paper pulp fibers.
Wherein the straw fiber preferably has a ratio of 10˜100 wt. %, more preferably 30˜97%, further preferably 51˜95%, most preferably 71˜93%.
The household paper of the present example can be prepared only by straw pulp fibers or by straw pulp fibers with other plant pulp fiber, such as wood pulp fiber, bamboo pulp fiber and so on.
The base paper of household paper has a tensile index of 1.5˜4 N·m/g, preferably 2˜3.5 N·m/g, more preferably 2.3˜3.2 N·m/g, and the visible dust of 0.3 mm 2 ˜2.0 mm 2 is 10˜500/m 2 , preferably 20˜400/m 2 , more preferably 30˜250/m 2 , and the visible hole of 2˜5 mm on the household paper is 2˜100, preferably 5˜80, more preferably 20˜60.
The dust and hole of the present example are all meet with the national standard definition, such as GB/T20808-2006. The base paper of the household paper of the present example has a basis weight of 10˜70 g/m 2 , preferably 15˜50 g/m 2 , more preferably 20˜40 g/m 2 . The color of the base paper is same as that of the straw pulp fiber and other plant pulp fiber themselves. The household paper of the invention refers to toilet paper, towel paper, wiping paper or tissue paper. Following is the specific embodiments:
A flake tissue paper, which is made up by one base layer manufactured by 50% straw pulp fibers and 50% of the unbleached wood pulp fibers, wherein the base paper has an basis weight of 10 g/m 2 , a whiteness of 45%, the color of the base paper is the color of the straw fiber and wood pulp fiber themselves, and the base paper has a tensile index of 1.5 N·m/g, particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 50 per square meter, and holes of 2˜5 mm of 3˜10.
A flake tissue paper, which is composed by three base layers manufactured by 100% of the straw pulp fibers, wherein the base layer has an basis weight of 70 g/m 2 , a tensile index of 4 N·m/g, a whiteness of 35%, particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 400-500 per square meter, holes of 2˜5 mm of 50˜100, and the color of the paper is the color of the straw fiber itself.
A flake towel paper, which is composed by two base layers manufactured by 30% of the straw pulp fibers and 70% of the wood pulp fibers, wherein the base layer has a basis weight of 15 g/m 2 , a tensile index of 2 N·m/g, a whiteness of 55-70%, particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 20 per square meter, and holes of 2˜5 mm of 70˜90, and the color of the paper is the color of the straw fiber and wood pulp fiber themselves.
A flake wiping paper, which is composed by four base layers manufactured by 60% of the straw pulp fibers and 40% of the wood pulp fibers, wherein the base layer has an basis weight of 50 g/m 2 , a tensile index of 3.5 N·m/g, a whiteness of 40%, particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 300 per square meter, and holes of 2˜5 mm of 30˜50, and the color of the paper is the color of the straw fiber and wood pulp fiber themselves.
A drum toilet paper, which is composed by three base layers manufactured by 80% of the straw pulp fibers and 20% of the wood pulp fibers, wherein the base layer has an basis weight of 20 g/m 2 , a tensile index of 2.5 N·m/g, a whiteness of 38-40%, particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 450 per square meter, and holes of 2˜5 mm of 10˜20, and the color of the paper is the color of the straw fiber and wood pulp fiber themselves.
A flake toilet paper made into long strip and folded, which is composed by two base layers manufactured by 10% of the straw pulp fibers and 90% of the bleached wood pulp fibers, wherein the base layer has a basis weight of 30-40 g/m 2 , a tensile index of 3-3.2 N·m/g, a whiteness of 65-75%, particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 20 per square meter, and holes of 2˜5 mm of 3˜15.
Example 5
This example is the same as example 4 except that, the composite layer of the office paper has a breaking length of 1.5˜5 km, preferably 2˜4.5 km, more preferably 2.5˜4 km, an opacity of 70˜100%, preferably 80˜99%, more preferably 85˜95%, a visible dust of 0.3 mm 2 ˜2.0 mm 2 of 10˜500/m 2 , preferably 20˜400/m 2 , more preferably 30˜250/m 2 , a whiteness of 35˜75%, preferably 35˜65%, more preferably 40˜60%, a basis weight of 20˜160 g/m 2 , preferably 30˜80 g/m 2 , more preferably 40˜70 g/m 2 , wherein, the base layer of the office paper has a Hue L values of 65-95, preferably 70-94, more preferably 80-91, a value of 0-5, preferably 0-4.5, more preferably 0-3, and b value of 0-40, preferably 0-35, more preferably 0-30.
At least one side of the base layer of office paper is coated by adhesive layer. It means that one side or both two sides can be coated by adhesive layer. The adhesive layer can be set by the method of the prior art, such as taking one or more of starch, animals glue and polyolefin to set adhesive layer, for example, using oxidized starch, polyacrylamide, polyethylene-maleic anhydride polymers, acrylic latex, modified polyvinyl alcohol, sodium carboxymethyl cellulose or styrene-acrylate and so on, wherein, the method of prior art comprises press sizing, tube sizing, off-machine sizing, spray sizing, roller press sizing or calendar sizing, wherein the amount of adhesive can be same as that of the prior art, preferably 1˜20 kg per ton of paper, more preferably 5˜15 kg per ton of paper, most preferably 7˜12 kg per ton of paper, wherein, the specific embodiments are as follows:
A flake offset printing paper has a basis weight of 20˜50 g/m 2 , a breaking length of 1.5˜2.5 km, a particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 300 per square meter, and an opacity of 100%, width of 10 cm, and length of 38 cm, which comprises a base layer manufactured by 50% of the straw pulp fibers and 50% of the unbleached wood pulp, wherein, both sides of the base layer are coated with adhesive, and the base layer has a whiteness of 45-50%, Hue L values of 50-89, a value of 0-2 and b value of 0-20.
A flake writing paper has a particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 500 per square meter and an opacity of 95%, which comprises a base layer manufactured by 100% of the straw pulp fibers, wherein, the base layer has a whiteness of 35-45%, one side of the base layer is coated with adhesive, and the color of the base layer is the color of straw fiber itself.
A flake writing paper has a particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 200 per square meter and an opacity of 80%, which comprises a base layer manufactured by 60% of the straw pulp fibers and 40% of the unbleached wood pulp fibers, wherein, the base layer has a whiteness of 40%, Hue L values of 65-75, a value of 2.5-3 and b value of 20-35.
A typing paper has a particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 450 per square meter, an opacity of 92% and width of 10 cm, length of 20 cm, wherein, the middle base layer is manufactured by 80% of the straw pulp fibers and 20% of the wood pulp fibers, which has a whiteness of 38-45%, Hue L values of 70-80, a value of 3.5-5, and b value of 30-35, wherein, two surface of the base layer are coated by adhesive layer of modified PVA, with the adhesive used of 10 kg per ton of paper.
A sheet typing paper with a particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 20 per square meter, and an opacity of 94%, which comprises a base layer manufactured by 10% of the straw pulp fibers and 90% of the wood pulp fibers, wherein, the base layer has a whiteness of 55-65%.
The base paper of office paper in the present invention is manufactured by straw pulp fibers and/or other plant pulp fibers, wherein the manufacturing refers to any manufacturing in the prior art, for example, mixing the straw pulp and other plant pulp after beating respectively, or mixing the straw pulp and other plant pulp before beating, which makes the straw fiber and other plant pulp fiber has a certain space structure, such as the space structure of the prior art.
The office paper refers to electrostatic copy paper, writing paper, offset printing paper or typing paper.
Example 6
This example is the same as example 4 and example 5 except that steps of cooking, washing and bleaching with small amount of bleacher can be carried out, wherein the bleacher with a small amount used in the present invention is 1/10˜¼ of the prior art. The base paper made by the straw pulp fiber obtained after oxygen delignification or bleaching with small amount of bleacher can be made into household paper and office paper.
The special embodiment is as follows: an electrostatic copy paper with a basis weight of 130˜160 g/m 2 , a breaking length of 2˜4.5 km, a particulate matter of 0.3 mm 2 ˜2.0 mm 2 of less than 20 per square meter, and an opacity of 92%, which comprises a base layer made by 30% straw fiber and 70% bleached wood pulp fiber, wherein the straw fiber is obtained after cooking, washing and bleaching with a small amount of ¼ of the prior art of bleacher, wherein both sides of the base layer are coated with adhesive, and the base layer has a whiteness of 65˜75%, Hue L values of 55-80, a value of 1.5-5, and b value of 9-35. Wherein, the electrostatic copy paper of the invention has a sizing of polyacrylamide. | A raw paper prepared by a mixed pulp including straw pulp, which can be used to prepare textbooks, writing papers and office paper with good performance, and the producing method of said raw paper are provided. The weight proportion of the straw pulp in the mixed stock is from 10% to 100%, and the straw pulp has a hardness of KMnO 4 value 10-17, an average fiber length of 0.1-2.5 mm, a tensile index of 23-57 Nm/g, a tearing index of 3.0-6.0 mN·m2/g, a folding endurance index of 2-6 kPa·m2/g and a whiteness of 28-50%. Either, the L value of the hue of said raw paper is 65-95, a value is 0-5, and b value is 0-40. The KMnO 4 value of hardness of the pulp after oxygen delignification is 10-14. The method includes: adding grass-series raw material into a digester, then adding cooking liquor, heating the cooking liquor to 100-200°, pressurizing to 0.3-0.9 MPa, cooking for 150-250 min, extruding the pulp, washing and obtaining the straw pulp. The amount of the ammonium sulfite of the cooking reagent is 5-20% of the absolute dry material, and the amount of the sodium hydroxide is 0-15% of the absolute dry material, the liquor ratio is 1:2-15. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on U.S. provisional applications 60/416,684 filed Oct. 7, 2002, and 60/431,355 filed Dec. 5, 2002, both hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
BACKGROUND OF THE INVENTION
[0002] The present invention relates to mechanisms for securing doors from being opened by small children, and in particular, to a device suitable for doors with lever-type door handles.
[0003] Architectural doors may have a latch mechanism holding the door closed and operated by means of a doorknob. Particularly for interior doors, the latch mechanism may be without a lock, and therefore readily opened by anyone turning the doorknob.
[0004] Parents with small children who wish to secure a door, for example, a door leading to stairs or other hazards, may make use of an add-on “safety lock” that prevents the child from opening the door. A commonly available safety lock for standard doorknobs covers the doorknob with a loosely fitting shell which rotates freely around the doorknob. A child grasping the shell can turn only the shell and not the contained knob. An adult with greater hand strength may compress the shell against the doorknob so as to enable rotation of the doorknob through the shell. This type of safety lock differentiates between adults and children in part by hand strength and requires that the doorknob be rotationally symmetric.
[0005] In recent years, such symmetric doorknobs have given way to lever handles which can be easier for the infirm and handicapped to actuate. A safety lock using a rotating shell design does not work with such lever handle systems, which are not rotationally symmetric, and have a wide variety of lever sizes.
[0006] Nevertheless, it is often desired to secure doors having such lever handles from opening by small children, and in fact, lever handles may in some cases be easier for small children to open, to the extent that the child may be drawn to reach up and hang upon the lever.
SUMMARY OF THE INVENTION
[0007] The present invention provides a safety lock for lever-type door handles that blocks rotation of the handle by bracing the handle against both the handle shaft and at least one stationary point on the door structure, typically the door jam. In this way, the lever need not be fully shrouded and a wide variety of different door handles may be accommodated.
[0008] Specifically, the present invention provides a child safety lock for doors with lever handles of a type having a rotatable shaft extending from the door and a lever extending radially from the handle shaft. The child safety lock comprises a lever grip engaging a portion of the lever and a fulcrum element attached to the lever grip to be positioned proximate to the shaft as a fulcrum. At least one arm having a first end attached to the fulcrum element extends radially therefrom to a second end sized to interfit with a stationary door structure. As configured, a force of rotation of the lever in an unlocking direction may be conducted by the lever grip through the fulcrum element to the shaft, and through the arm to the stationary door structure.
[0009] Thus it is one object of the invention to provide an add-on safety lock for lever door handles.
[0010] The arm may be sized so that the second end interfits with a door jam adjacent to the door handle when the door is closed.
[0011] Thus it is another object of the invention to engage a structure commonly available near the handle.
[0012] The fulcrum element may be a collar surrounding the shaft.
[0013] Thus it is another object of the invention to provide a mechanism that is retained when locked and unlocked.
[0014] The collar may include at least a first and second collar portion separable for insertion of the shaft within the collar.
[0015] Thus it is another object of the invention to provide a collar that may conform closely to the shaft of the handle without creating problems installing it over the lever.
[0016] The collar may include at least one latch for releasably retaining the collar in a closed position around the shaft after the shaft is inserted into the collar.
[0017] It is thus an object of the invention to prevent accidental dislodgment of the collar from the shaft.
[0018] The collar may include space-filling elements allowing the inner opening of the collar to conform to shafts of different diameters.
[0019] It is thus another object of the invention to accommodate multiple handle designs with different-sized shaft or shafts that are not cylindrical.
[0020] The space filling elements may be spring fingers extending inward from an inner edge of the collar to flexibly press against the outer circumference of the shaft.
[0021] It is thus an object of the invention to provide an embodiment in which multiple spacer elements need not be provided, but which may conform and automatically adjust to the shaft size.
[0022] The arm may include a release allowing it to be displaced from interfitting with the stationary door structure for rotation of the lever.
[0023] It is thus another object of the invention to allow an adult operating the release to open the door without detaching the safety lock from the handle.
[0024] The arm may include a pivot operating about an axis substantially parallel to the axis of the shaft and the release may be a catch preventing pivoting of the arm except when the catch is released.
[0025] It is thus another object of the invention to provide a release mechanism that is simple and does not produce unwieldy extensions from the door.
[0026] The lever grip may be a collar surrounding the lever.
[0027] It is thus another object of the invention to provide a positive retention of the lever and a gripping of levers of arbitrary length in a single device.
[0028] The safety lock may include a second arm extending radially from the fulcrum to a second end sized to interfit with a stationary door structure.
[0029] It is thus another object of the invention to provide a lock that may block two directions of rotation of the lever handle.
[0030] The lever grip fulcrum element and arm may be polymer materials.
[0031] Thus it is another object of the invention to provide a device that is simple to manufacture but that reduces risk of damaging or marring the door when in direct contact with the door.
[0032] The release mechanism may be oriented on top of the safety lock when the safety lock is in place and locked on a door handle.
[0033] Thus it is another object of the invention to displace the release mechanism from the access by or sight of small children.
[0034] The arms may have feet portions that ride against the front surface of the door.
[0035] It is another object of the invention to provide a lock that rests stably on the door when attached to the door handle.
[0036] These particular objects and advantages may apply to only some embodiments falling within the claims, and thus do not define the scope of the invention.
BRIEF DESCRIPTION OF THE FIGURES
[0037] FIG. 1 is a an exploded perspective view of the three components of the safety lock of a preferred embodiment of the invention partially assembled around a lever door handle shown in phantom;
[0038] FIG. 2 is a fragmentary cross-sectional, front elevational view through the assembled invention along lines 2 - 2 of FIG. 1 showing attachment of two collar portions about the shaft of the handle and the compression of space filling elements therein;
[0039] FIG. 3 is a right side, elevational view of a lever grip attached to one of the collar portions for receiving the lever in a cage to retain the lever, the figure further showing the offset of the cage with respect to the collar;
[0040] FIG. 4 a is a fragmentary right side, elevational view of a collar tab for holding the collar portions together;
[0041] FIG. 4 b is a cross-sectional view through the collar tab along lines 4 b - 4 b showing a stop blocking the disengagement of barbed fingers;
[0042] FIG. 5 is a front elevational view of the assembled components of FIG. 1 showing blocking of the handle of a door against clockwise rotation by a first arm abutting a door jam;
[0043] FIG. 6 is a cross sectional view along lines 6 - 6 of FIG. 1 showing a release allowing a folding back of a second arm of FIG. 7 ; and
[0044] FIG. 7 is a fragmentary view similar to that of FIG. 5 showing a folding back of a second arm allowing lifting of the lever.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0045] Referring now to FIG. 1 , a lever-type door handle 10 includes an escutcheon plate 12 fitting against a front surface of the door 14 . A shaft 16 may extend from the door 14 along a shaft axis 18 about which the shaft 16 may turn. A lever 20 extends radially from the exposed end of the shaft 16 to be grasped by the user to rotate the shaft 16 to operate a latch mechanism within the door (not shown) as is generally understood in the art.
[0046] Referring also to FIG. 2 , a safety lock 22 per the present invention provides a first collar portion 24 having a hemicylindrical opening 26 for fitting about a left side of the shaft 16 as depicted and a second collar portion 28 having a hemicylindrical opening 30 for fitting about a right side of the shaft 16 , together providing a cylindrical bore through which shaft 16 may pass.
[0047] As seen in both FIGS. 1 and 2 , space filling elements 36 may extend inward from the inner surfaces of the hemicylindrical cavities of first collar portion 24 and second collar portion 28 ; the space filling elements. 36 being flexible fingers diverging from a line of diameter of the formed cylindrical bore in a V-form opening toward the center of the cylindrical bore. The fingers may flex outward to fill the space between the outer circumference of the shaft 16 and the inner surface of the formed cylindrical bore preventing looseness in the interfitting of the first collar portion 24 and second collar portion 28 about the shaft 16 such as would cause a rattling or inadvertent pivoting thereabout.
[0048] Referring now to FIGS. 1, 3 , 4 a, and 4 b, the second collar portion 28 may be held to first collar portion 24 by barbed fingers 32 extending horizontally from the first collar portion 24 and passing through retaining slots 48 on collar tabs 34 on second collar portion 28 . The barbed fingers 32 may flex inward to allow their outwardly extending barbs 50 to pass through the slots 48 in the collar tabs 34 and engage the outer surface thereof. Further engaging motion of the barbed fingers 32 and collar tabs 34 is stopped by molded stop 52 projecting upward from first collar portion 24 between the barbed fingers 32 .
[0049] Outward flexure of the barbed fingers 32 is sufficient to hold collar tabs 34 of second collar portion 28 in place, however, additional security is provided by means of stop plates 56 attached by living hinges 58 to an outer edge of the collar tabs 34 . The stop plates 56 fit between tips of the barbed fingers 32 after they have passed through the collar tabs 34 preventing them from flexing inward such as might disengage their barbs 50 from the surface of the collar tabs. A T-retainer 59 extends outward from the collar tabs 34 to be received in a dual width slot 60 in the stop plate 56 . One portion of the dual width slot 60 allows free passage of the head of the T-retainer 59 through the dual width slot 60 while the other portion of the dual width slot 60 is sufficiently narrow to block passage of the head of the T-retainer 59 thereby capturing the stop plate 56 beneath the head of the T-retainer 59 . A handle 62 projects outward from the stop plate 56 to allow engagement and disengagement of the stop plate 56 from the T-retainer 59 .
[0050] As described, the first collar portion 24 and second collar portion 28 may be thus easily assembled and disassembled about the shaft 16 without needing to thread the collar so formed over lever 20 .
[0051] Referring to FIGS. 1,2 , and 3 , the second collar portion 28 includes a cage 40 defining an opening 42 through which the lever 20 may pass to be surrounded on all sides. This opening 42 may also have space filling elements (not shown) allowing the cage 40 to conform to handle levers 20 of different widths and thicknesses or a single opening size may be used, as shown, allowing some limited and acceptable handle rotation.
[0052] As shown in FIG. 3 , generally the opening 42 of the cage 40 is offset outward from the door 14 with respect to the second collar portion 28 around the shaft 16 . This offset is reversed for the lever on the opposite side of the door and yet both lever directions may be accommodated by a 180-degree rotation 46 of the second collar portion 28 about a radial axis 44 , prior to its engagement with first collar portion 24 as shown in FIG. 1 . The barbed fingers 32 of the first collar portion 24 and the slots 48 of the collar tabs 34 of the second collar portion 28 are symmetric so as to allow this rotation 46 while still permitting the connection between the barbed fingers 32 and the slots 48 . In this way, lever handles on either side of the door 14 may be secured with the present device.
[0053] Referring now to FIGS. 1 and 5 , attached to the first collar portion 24 are an upper arm 68 and lower arm 64 , each extending radially from the shaft 16 at approximately equal angular spacing about axis 18 to each other as to the lever 20 . The arm 64 is sized so that downward motion (clockwise) of the lever 20 , acting through the cage 40 against a fulcrum provided by the first and/or second collar portions 24 and 28 , brings the distal end of arm 64 upward into abutment with the vertical jam wall 66 being part of the casing of door structure. Conversely, upward motion (counterclockwise) of the lever 20 acting through the cage 40 against a fulcrum provided by the first and/or second collar portions 24 and 28 brings the distal end of arm 68 downward against the vertical jam wall 66 .
[0054] The arms 64 and 68 are sized so that the free rotation of the lever 20 is insufficient to cause the lock mechanism with the door 14 to withdraw the bolt (not shown) holding the door shut. The arms 64 and 68 include at their distal ends, spreaders 67 extending axially that provide an edge that may ride along the face of the door 14 to stabilize the safety lock and ensure engagement with the jam.
[0055] It will be understood that arms 64 and 68 together prevent the opening of the door 14 by moving the lever 20 up or down. This is the highest level of security. The arm 64 alone may, however, prevent the opening of the closed door 14 where the expectation is that the child will only be able to pull downward on the lever 20 . In this case, a parent or guardian may simply raise the lever 20 to open the door 14 .
[0056] An opening of the door 14 or this lower level of security may be obtained by a retraction of lever arm 68 through the use of a release lever 70 . Referring to FIGS. 1, 7 , and 6 , this retraction of arm 68 is accomplished by attaching arm 68 to first collar portion 24 by means of pivot pins 72 extending axially from the first collar portion and fitting within corresponding pivot holes 74 in the proximal end of arm 68 so that arm 68 may swing about an axis generally parallel to axis 18 while remaining adjacent to the plane of the door 14 . Unintended retraction of the arm 68 when the lever 20 is to be locked against upward motion is provided by means of a flexible hook 76 extending within the arm 68 from its distal to proximal end. The hook engaging a catch surface 78 attached to the first collar portion 24 between the pivot pins 72 to which the arm 68 is attached. The hook 76 , when engaged, resists upward motion 80 of the arm 68 until the hook 76 is disengaged from the catch surface 78 by a backward pressing of the release lever 70 as indicated by arrow 82 .
[0057] The above-described design is amenable to injection molding where each of the arm 68 , the first collar portion 24 and the second collar portion 28 are separately molded as integral parts and assembled, the first collar portion 24 and second collar portion 28 assembled together via the barbed fingers 32 as described above, and the arm 68 assembled to the first collar portion 24 by snapping it onto the pivot pins 72 . Fabricating the safety lock of the present invention from plastic material such as polypropylene provides for good resilience and low risk of marring the door 14 and the flexibility required of the space filling elements 36 , living hinge 58 , and flexible latch hook 76 .
[0058] While what has been described is a preferred embodiment, it will be recognized that the principle described herein may be applicable to safety locks which engage stationary door structure not limited to the casing surrounding the door but including, for example, the slot between the door and the casing as gripped by a pin or blade extending into the slot from the distal ends of one or both of arms 64 and 68 .
[0059] From the description herein, variations of this invention will be understood to include those which engage portions of the surface of the door 14 with frictional elements and semi-permanent attachments to the front surface of the door. Although a collar that fully surrounds the shaft 16 is described, it will be understood that during normal use only portions of the collar contact the shaft 16 , and therefore a collar which does not fully enclose shaft 16 may be used.
[0060] It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. | An add-on safety lock for lever-type handles blocks lever rotation by bracing the lever against a fulcrum point at the handle shaft and nearby door structure. | 4 |
FIELD OF THE INVENTION
This invention relates to power tongs used for the make-up or break-out of tubular materials.
BACKGROUND TO THE INVENTION
When drilling, as in the oil industry, a power tong and backup combination is commonly used to effect a connection between one pipe and another. In order to “makeup” or “break-out” a connection between pipe sections during drilling, it is necessary to hold or clamp the collar or body of the receiving pipe so that it will remain stationary while the other pipe is rotated into engagement with the stationary pipe. This function is done by the use of a “backup tong”, often called simply a “backup”.
Generally, but not exclusively, the backup is located below the main rotary tong. A backup may be C-shaped, fully closed, or initially open prior to gripping, but closed during gripping, as for example in U.S. Pat. No. 5,702,139 (Buck). The backup is normally hydraulically operated (other methods include pneumatic and manual operation) and due to the nature of its function it is desirable that it be as simple as possible in design. The design of a backup generally includes a set of two or more jaws; a means for connecting the backup to the rotary tong; and provision to make a connection to a rigid anchor point in order to absorb the reaction torque on the stationary pipe arising from the torque applied to the rotating pipe by the rotary tong.
Typically, but not exclusively, on a well site a rotary tong/backup assembly is moved into place so that the backup can grasp the stationary pipe. After centering the stationary pipe in the central opening of the backup, the backup is activated to move its jaws into engagement with the pipe. The jaws bite into the pipe to provide sufficient radial force to overcome the tangential force generated by the torque of the rotary tong. Once the stationary pipe is held in place by the backup, the rotary tong provides torque to the rotating pipe in order to make up the joint. The applied torque builds up until the joint is closed. Once the connection is torqued to its final target value, the backup jaws are released from the anchor and retracted from the stationary pipe.
A common form of backup usually includes one or more cylinders (operated either hydraulically or pneumatically), each of which drive a jaw, either directly or indirectly, along a guided slot radially toward the pipe until a sufficient clamping force is attained. This form of backup generally includes a fixed jaw that reacts against this force and serves to center the pipe; along with the aforementioned driving jaw(s).
References herein to “jaws” may be taken as referring to the combined assembly of the jaw carrier and the die that is carried into contact with the pipe, unless the context indicates otherwise.
A number of desired characteristics of a backup tong include: a sufficient clamping force that holds the stationary pipe while torquing; a limit in size and weight to allow the unit to be used on smaller rig floors and/or snubbing baskets; allow the use of jaws which are interchangeable with the tong, thereby reducing the number of spare jaws required to be stocked by the operator; allow the use of wraparound dies; reduce the quantity of parts thereby reducing cost and inventory; optimize the speed with which the jaws engage the stationary pipe while ensuring that the desired maximum torque can be achieved and supported; and generate a controlled radial force required to grip the pipe while minimizing the hydraulic pressure requirement and avoid crushing of the pipe itself.
U.S. Pat. No. 4,494,425 (Shewmak Sr.) discloses a backup tong wherein a moveable jaw is carried at the end of a lever arm that pivots about a pivot point. The end of the lever arm remote from the jaw is actuated by an air cylinder, causing the jaw at the other end to swing in an arc towards contact with a pipe. The pivot axis is eccentric to a curved face of the moveable jaw, so that as the moveable jaw is swung towards the pipe the jaw closes on the pipe. A disadvantage of this configuration is that the jaw, as it advances further towards the pipe once contact is made, tends to move transversely across the face of the pipe.
U.S. Pat. No. 4,402,239 (Mooney) discloses a backup tong wherein the jaw is carried on a jaw carrier that slides radially towards the pipe to be engaged. The jaw carrier is driven into engagement with the drill pipe by one end of a lever that pivots about a pivot point fixed with respect to the tong body, the other end of the lever being coupled to a hydraulically-driven push rod. In this configuration no provision is made for having distinct rates of advancement of the jaw towards the pipe as the lever rotates about its pivot point. Additionally, the radial force generated is purely based on the differential between the pivot point to cylinder attachment, and the pivot point to roller contact point.
In the aforementioned prior art references, the radial force provided by the jaws will vary to some degree, depending on the state of the pipe, which is often oversize or worn.
Accordingly, it would be desirable to provide a backup tong wherein provision is made for having distinct rates of advancement of the jaw towards the pipe as an activating lever is being rotated in order to effect engagement of the jaw with such pipe. It would also be desirable to provide for a design option for controlling the amplification factor for the force originating from an actuator and giving rise to the force being applied by a jaw to the pipe.
SUMMARY OF THE INVENTION
In one aspect of the present invention, there is provided a backup tong comprising: a body with a central opening for receiving a tubular body; a fixed jaw assembly mounted on the backup tong body for engagement with the tubular body; a sliding jaw assembly mounted on the backup tong body for sliding engagement with the tubular body; an activating mechanism for slidingly advancing the sliding jaw assembly onto engagement with the tubular body positioned centrally within the opening, the activating mechanism comprising: (a) a cam arm which pivots around a fixed pivot point on the body of the backup tong, the cam arm comprising a first extension and second extension; the first extension having a cam surface in contact with the sliding jaw assembly thereby defining a point of contact on the cam surface; the cam surface comprising a rapid surface portion for rapid advancement of the sliding jaw assembly and a slow surface portion for slow advancement of the sliding jaw assembly; and (b) an actuating mechanism for providing rotation of the cam arm about the pivot point, the actuating mechanism mounted on the tong body and connected to the second extension; wherein upon rotation of the cam arm by the actuating mechanism, the point of connection first traverses along the rapid surface portion and then the slow surface portion, resulting in rapid advancement of the sliding jaw assembly upon initial approach towards the tubular body, followed by slow advancement of the sliding jaw assembly upon close approach and engagement with the tubular body.
In another aspect of the present invention, there is provided a backup tong comprising: a body with a central opening for receiving a tubular body; a first sliding jaw assembly mounted on the backup tong body for sliding engagement with the tubular body; a first activating mechanism for slidingly advancing the first jaw assembly onto engagement with the tubular body positioned centrally within the opening; a second sliding jaw assembly mounted on the backup tong body for sliding engagement with the tubular body; a second activating mechanism for slidingly advancing the second jaw assembly onto engagement with the tubular body positioned centrally within the opening; each activating mechanism comprising: a cam arm which pivots around a first fixed pivot point on the body of the backup tong, the cam arm comprising a first extension and second extension; the first extension having a cam surface in contact with the respective sliding jaw assembly thereby defining a point of contact on the cam surface; the cam surface comprising a rapid surface portion for rapid advancement of the respective sliding jaw assembly and a slow surface portion for slow advancement of the respective sliding jaw assembly; and an actuating mechanism for providing rotation of the cam arm about the pivot point, the actuating mechanism mounted on the tong body and connected to the second extension; wherein upon rotation of the cam arm by the actuating mechanism, the point of connection first traverses along the rapid surface portion and then the slow surface portion, resulting in rapid advancement of the respective sliding jaw assembly upon initial approach towards the tubular body, followed by slow advancement of the respective sliding jaw assembly upon close approach and engagement with the tubular body.
According to one embodiment of the invention a backup comprises an activating mechanism for advancing a jaw die mounted on a jaw carrier within the backup into engagement with a pipe positioned centrally therein. The jaw carrier is fitted within the tong body to permit a sliding action radially toward the center point of the opening in the backup tong. Such mechanism includes a cam surface located along a first extension of a cam arm which pivots around a fixed pivot pin carried by the body of the backup. The other extension of the cam arm is connected toward its outer end to an actuator (for example, a hydraulic cylinder), anchored at one end to the backup body and oriented at the other end to swing the cam arm about the pivot pin.
The cam surface is located along an edge-face portion of the first extension of the cam arm so as to present the cam surface for connecting with a portion of a jaw carrier. The cam surface may connect with the jaw carrier on the end of the jaw carrier remote from the pipe or through any other portion of the jaw carrier that will permit the jaw carrier to move in response to movement of the cam surface. Rotation of the cam arm changes the point of connection between the jaw carrier and the cam surface, resulting in the advancement of the jaw carrier towards the pipe.
Just as the jaw engages the pipe (and subsequently tightens the engagement), the point of connection between the jaw carrier and the cam surface tends to move nearly, but not precisely, transversely across the face of the cam surface with further rotation of the cam arm.
The shape of the cam surface in this region is chosen so as to provide a selected amplification factor for the force originating from the actuator and giving rise to the force being applied by the jaw to the pipe.
The cam surface may further be provided with a profile which includes two portions: a first portion for advancing the jaw carrier rapidly towards the pipe at it approaches engagement, and a second portion for advancing the jaw carrier more slowly towards the pipe in the terminal stage of its engagement (i.e. gripping), based on a constant speed of advancement of the actuator. This distinction in the portions of the cam surface allows the invention to achieve distinct rates of advancement of the jaw towards the pipe.
During the approach stage of jaw engagement, there is relatively little resistance to advancement of the jaw carrier. However, during the gripping stage of engagement (i.e. when the jaw is in contact with the pipe), substantial resistance will be encountered. If the actuator is a hydraulic cylinder, the hydraulic pressure will approach a maximum as the jaw contacts the pipe. Advancement of the jaw at this stage is limited to the engagement of serrations on the gripping face of the jaw with the outside surface of the pipe, and the compression and the deflection of the components transporting the driving force to the jaw-pipe interface, and to deformation of the pipe itself.
Control of this force is critical due to the possibility that it may deform the pipe beyond its elastic limit and therefore make the pipe out-of-round.
The orientation of the two portions of the cam surface with respect to the direction of a radial line (which extends from the center of the tong outwardly through the jaw carrier and also defines the direction of travel of the jaw carrier), can be measured by a “cam angle”, defined as the angle between the radial line and the tangent to the connection point between the jaw carrier and the cam surface. The cam angle at the fast portion of the cam surface is much less than the cam angle along the slow portion of the cam surface. Alternately, the tangent to the connection point along the slow portion of the cam surface, is more transverse to the radial line, than the tangent to the connection point along the fast portion of the cam surface.
The smaller the cam angle between the radial line and the tangent to the fast cam surface portion at the point of jaw carrier connection, the faster the jaw will advance from the retracted position as the cam arm is rotated. Since the maximum angular travel of the cam arm itself under actuation is typically about 90 degrees, it is desirable to shape a cam profile which progressively decreases the cam angle along the extent of the fast cam region, in order to avoid undue limitations on the available length of the slow cam surface. The transition area between the fast and slow cam surfaces may be shaped to include a radius in the transition surface.
The length of the respective extensions of the cam arm, and the profile of the slow cam surface portion collectively control the degree to which the force applied by the cam arm actuator is multiplied as the final compressive force is applied at the jaw-pipe interface. When the profile of the slow cam surface portion is shaped to allow the cam angle to progressively become more nearly aligned fully transverse to the radial line passing through the jaw carrier, the degree of amplification of force is also progressively increased along the path of jaw carrier travel. If the slow cam surface is aligned fully transverse to the radial line, the advancement of the jaw into the pipe with the rotation of the cam arm would ultimately cease altogether. If, by this point, the jaw has not fully advanced into a non-slipping engagement with the pipe, the backup will fail to achieve its purpose. The slow cam surface portion must therefore be shaped such that the its surface contour has a cam angle oriented along a line that that is relatively close to, but not fully transverse to the radial line, in order to ensure the jaw's continued advancement while providing an appropriate amplification factor for force. Accordingly, the working profile of the slow cam surface is a sensitive variable for the proper operation of this backup.
The slow cam surface portion of the cam arm may be advantageously, but not necessarily, shaped to provide a greater cam angle than that of the fast cam surface portion, with respect to the radial line of jaw carrier travel, in order to provide greater force amplification and a slower jaw closing speed relative to the work pipe. Slow cam surface angles very close to tangential to the radial line may create high resultant forces on the driving jaw, and may also result in a self-locking cam condition, wherein the cam becomes difficult to break free upon jaw retraction.
Smaller slow cam angles provide a lesser mechanical advantage, and at lower angles the resultant forces on the driving jaw could prove too low to create a useful pressure of the jaw against the pipe. This means that the determination of the optimal range of slow cam surface tangent angles requires balancing sufficient force for useful jaw grip on a pipe against the development of excessive jaw forces that can crush or otherwise damage the pipe and potentially lock-up the backup tong.
Within the above angular range considerations, a nearly linear contour with a constant cam angle on the slow cam surface will allow the jaw to move inwardly at a nearly constant rate as the cam arm is rotated by advancement of the actuator at a constant speed. In this case however, the resultant force on the jaw roller will change dynamically during cam arm travel, due to the progressive change of the angle between the applied actuator force and the cam arm, with the jaw roller force being greatest when the actuator force is perpendicular to the cam arm. This variation in transmitted jaw roller force can be mitigated by shaping the slow cam surface contour as a continuous curve that accommodates and counteracts such driving force variations.
The transition point between jaw-approaching fast cam surface and the pipe-gripping slow cam surface portions should preferably be set to engage with the jaw carrier just as the jaw is arriving at the pipe. The length of the slow cam surface portion should be sufficient to ensure that, with further rotation of the cam arm, the jaw will become fully engaged with the pipe with adequate gripping force to secure it.
In the preferred design case where the slow cam surface, defined by its tangent cam angles, is not aligned fully transversely to the radial line but is approaching this limit, the operator should take care to limit the force being generated by the cam arm actuator, in order to prevent the application of damaging excessive radial force to an engaged pipe.
In the above summary a mechanism for advancing a single jaw towards pipe has been described. The invention is applicable to a case where the backup has two jaws, one fixed, and one displaceable. In such case, the fixed jaw would be shaped and positioned to be centrally aligned with the center of pipe to be gripped. It is also possible to include two or more actuated jaws in a backup, there being independent actuators provided for each of the actuated jaws.
To reduce friction, it is preferable that the portion of the actuated jaw's carrier that connects with the cam surface be provided with a friction-reducing cam follower or roller. This can be in the form of a roller fitted to the jaw carrier. The point of contact between the cam surface and roller is preferably close to, or directly on the radial line, in order to minimize sideways forces on the jaw carrier.
The cam arm backup according to the invention advantageously provides programmed rates of advancement of the jaw along its travel towards the pipe and during engagement. It also provides for a design option for deterministic control of the amplification factor giving rise to optimum forces being applied by a jaw to a pipe.
Due to the simplicity of the design and the low number of parts used, the cam arm backup may be constructed so as to be of reduced size and weight when compared to many other typical backup units. Additionally, the cam arm actuating system of the invention allows two simple jaws to be used for the clamping action, rather than the traditional three. This allows the use of specialized dies, as well as permitting the dies to be used in an open mouth backup without the need for the door which is traditionally used to house a jaw in three jaw backups relying on a mechanical advantage. Further, the use of the cam allows a variable amplification of force and speed permitting the use of smaller bore actuating cylinders of reduced stroke.
Generally the reduced size of the jaw assemblies will avoid the requirement for a jaw retraction mechanism, as the smaller jaws are easily displaced by the pipe as it is moved into place or removed. However in alternate embodiments the jaws may be either retracted by the actuator or fitted with an independent retraction method mounted between the backup and the jaw.
The invention in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention in its broadest and more specific forms will then be further described, and defined, in each of the individual claims which conclude this Specification.
The foregoing summarizes the principal features of the invention and some of its optional aspects. The invention may be further understood by the description of the embodiments which follow,
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a backup tong with a driving jaw in the retracted position, and top plate removed.
FIG. 2 is a detailed plan view of a backup tong jaw mechanism in the retracted position.
FIG. 3 is a plan view of a backup tong, with a driving jaw extended in clamping engagement with a pipe.
FIG. 4 is a detailed plan view of a backup tong jaw mechanism, with a driving jaw extended in clamping engagement with a pipe.
FIG. 5 is a detailed plan view of a cam arm.
FIG. 6 is a detailed plan view of a cam arm showing the respective orientations of a cam following roller as it progresses along cam surfaces.
FIG. 7 is a detailed plan view of a cam arm showing the position of a cam following roller in the starting, fully retracted position.
FIG. 8 is a detailed plan view of the cam arm of FIG. 7 showing the position of the cam following roller at a transition point between fast and slow cam surface.
FIG. 9 is a detailed plan view of the cam arm of FIG. 7 showing the position of the cam following roller at the end of the slow cam surface.
FIG. 10 is a representative graph of a back-up tong's driven jaw displacement plotted against a hydraulic actuator extension.
FIG. 11 is a plan view of a backup tong, with two actuated jaws in clamping engagement with a pipe.
The following is given by way of illustration only and is not to be considered limitative of this invention. Many apparent variations are possible without departing from the spirit and scope thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the FIGS. 1-4 , a backup tong has a body 2 with a central opening 3 and a throat 4 . The tong body 2 is moved into position around pipe 4 . Central opening 3 is preferably C-shaped. Attached to the top of tong body 2 at one side of the central opening 3 is a stationary jaw carrier 5 , which projects into the central opening 3 such that stationary jaw 6 can be placed into contact with centrally-positioned pipe 1 .
At the opposite side of central opening 3 , a second complimentary driving jaw carrier 7 is positioned to allow radial motion with respect to tong body 2 . Driving jaw 8 makes contact with pipe 1 as jaw carrier 7 is advanced towards pipe 1 . Cam-following roller 9 , which runs against the contoured edge face 13 of cam arm 10 , is mounted at the distal end of jaw carrier 7 .
As shown in FIG. 1 , cam arm 10 is rotatably mounted on a fixed pivot pin 19 secured to tong body 2 . Fixed pivot pin 19 and cam following roller 9 are disposed along a radial line 18 that extends from the center of tong body opening 3 through the driving jaw carrier 7 . Driving jaw 8 travels along radial line 18 .
As shown in FIG. 5 , cam arm 10 is generally angular in shape, with two extensions projecting from its pivot point 11 . The first cam arm extension 12 has an edge face 13 upon which is formed the cam surface which bears against jaw roller 9 . The edge face 13 is shaped into three distinct cam surfaces 14 , 15 and 16 .
Referring to FIGS. 5 and 6 , it can be seen that the first cam surface 16 (or “fast cam surface”) is characterized by a relatively low cam angle (defined previously as the angle between the tangent at the point of connection relative and the radial line 18 ). The second cam surface 15 (or the “transition cam surface”) then leads into the third cam surface 14 (or “slow cam surface”), which has a higher cam angle.
As shown in FIGS. 1-4 , the second extension 17 of cam arm 10 is attached by drive linkage 20 to hydraulic piston rod 21 , and serves as the effort arm of the lever composed of cam arm 10 across the fulcrum of pivot pin 19 . Hydraulic cylinder 22 serves as a linear actuator to drive this lever and thus operate the backup tong's jaw mechanism.
FIGS. 1 and 2 show the backup tong positioned to begin engagement with pipe 1 . Here the tong body 2 has been placed such that stationary jaw 6 is in contact with the pipe; piston rod 21 is fully retracted into hydraulic cylinder 22 , which places cam arm 10 in its starting position; and the driving jaw carrier 7 is at its furthest point of retraction.
As shown in FIGS. 6 and 7 , cam arm 10 is thus in its starting position, with the onset point of fast cam surface 16 lying along radial line 18 , and the cam following jaw roller 9 is in contact with fast cam surface 16 at its retracted starting position 23 .
When hydraulic cylinder 22 is pressurized, piston rod 21 is driven outwardly from the cylinder and expresses force against cam arm drive linkage 20 . This driving force induces cam arm 10 to rotate about pivot pin 19 such that the fast cam surface 16 begins to act against jaw roller 9 .
Referring to FIG. 7 , as jaw roller 9 moves from its starting position 23 , it must initially ascend the relatively steep fast cam starting angle 26 . Thus, at the outset of motion, the roller 9 and connected jaw carrier 7 move quite rapidly along radial line 18 , and the distance between driving jaw 8 and pipe 1 closes quickly. As roller 9 proceeds along fast cam surface 16 to the transition region 15 , the angle faced by the roller decreases progressively, and jaw carrier travel begins to slow.
This slowing can be seen in the representative graph of FIG. 10 , which plots the displacement of the driving jaw 8 versus extension of the hydraulic actuator, for a pipe of nominal diameter. The slowing can be seen in FIG. 10 as the gap between driving jaw 8 and the pipe 1 decreases at a declining rate as hydraulic cylinder displacement moves from 0 to about 1.4 inches, at which point the cam surface contact point of roller 9 approaches transition cam surface 15 .
As the hydraulic piston rod 21 continues its outward travel from cylinder 22 , the longitudinal axis of the cam arm's second extension 17 preferably approaches an orientation approximately perpendicular to radial line 18 , advancing the cam surface contact point of jaw roller 9 across the transition cam surface 15 . At the point when the cam arm's second extension 17 has reached approximate perpendicularity to radial line 18 , jaw roller 9 has attained its slow cam starting position 24 , as can be seen in FIGS. 6 and 8 , and on the graph of FIG. 10 at about 1.7 inches of hydraulic cylinder displacement.
With reference to FIGS. 3 and 8 , it can be seen that with continued driving force applied by hydraulic piston rod 21 , and with the cam arm extension 17 approximately perpendicular to radial line 18 , the resultant force on roller 9 derived from the lever of cam arm 10 against pivot pin 19 will reach its maximum range. The lower rate of advancement of the contact point between the slow cam surface 14 and the jaw roller 9 causes a concomitant reduction in the travel rate of the jaw carrier 9 along radial line 18 . As cam arm extension 17 continues to rotate, its longitudinal angle with respect to radial line 18 grows beyond the optimal power transfer altitude of 90 degrees off the radial line 18 depicted in FIG. 8 . To mitigate the decrease in resultant force against jaw roller 9 , the contour of slow cam surface 14 is shaped to progressively reduce the cam angle as the jaw roller proceeds along, thus allowing a continuance in the application of high resultant force on jaw roller 9 . The compensating effect of this contoured progressive reduction in the angle of attack of slow cam surface 14 can be seen in the representative graph of FIG. 10 , with a relatively linear decrease in jaw separation from the pipe along the section of the domain from about 1.7 inches to about 4.0 inches of hydraulic cylinder displacement. At this terminal point of travel, cam arm 10 has reached the orientation illustrated in FIGS. 6 and 9 , and jaw roller 9 has attained limit position 25 .
At this limit point 25 , and as jaw roller 9 travels further along slow cam surface 14 beyond this point, there will be no further advancement of the jaw carrier 7 , and no further increase in the gripping force applied to pipe 1 .
FIG. 11 illustrates an embodiment with two actuated jaws in a backup, with independent actuators provided for each of the actuated jaws. First and second sliding jaw assemblies ( 110 , 120 ) are mounted on the backup tong body for sliding engagement with the pipe ( 1 ). The first sliding jaw assembly ( 110 ) is identical to that shown in FIG. 3 , and so identical reference numerals are used. The first sliding jaw assembly includes the driving jaw carrier ( 7 ) and driving jaw ( 8 ). Similarly, the first activating mechanism for slidingly advancing the first sliding jaw assembly, is identical to that shown in FIG. 3 , and so, identical reference numerals are used.
The second sliding jaw assembly ( 120 ) and the second activating mechanism ( 118 ) have the same basic components as the first sliding jaw assembly ( 110 ) and the first activating mechanism, respectively. For example, the second sliding jaw assembly ( 120 ) includes a second complimentary driving jaw carrier ( 115 ) and driving jaw ( 116 ) which makes contact with pipe ( 1 ) as jaw carrier ( 115 ) is advanced towards pipe ( 1 ). The second activating mechanism ( 118 ) slidingly advances the second sliding jaw assembly ( 120 ) in an identical manner as the first activating mechanism acts first sliding jaw assembly ( 110 ).
CONCLUSION
The foregoing has constituted a description of specific embodiments showing how the invention may be applied and put into use. These embodiments are only exemplary. The invention in its broadest, and more specific aspects, is further described and defined in the claims which now follow.
These claims, and the language used therein, are to be understood in terms of the variants of the invention which have been described. They are not to be restricted to such variants, but are to be read as covering the full scope of the invention as is implicit within the invention and the disclosure that has been provided herein. | A backup tong that comprises an activating mechanism for advancing a jaw die mounted on a jaw carrier within the backup into engagement with a pipe positioned centrally therein. The jaw carrier is fitted within the tong body to permit a sliding action radially toward the center point of the opening in the backup tong. Such mechanism includes a cam surface located along a first extension of a cam arm which pivots around a fixed pivot pin carried by the body of the backup. The other extension of the cam arm is connected toward its outer end to an actuator, anchored at one end to the backup body and oriented at the other end to swing the cam arm about the pivot pin. | 4 |
RELATED APPLICATION DATA
This application is a continuation of copending provisional application Ser. No. 60/008,071 filed Oct. 25, 1995, the disclosure of which is incorporated by reference.
TECHNICAL FIELD
The present invention relates to a communication antenna system fed through a dielectric wall, and more particularly relates to through-glass coupling systems for antennas used at frequencies above 1.5 GHz (e.g. PCN, PCS, and ISM services).
BACKGROUND AND SUMMARY OF THE INVENTION
Window mounted antennas have gained more and more popularity in mobile radio links, especially in cellular telephone communications because of their obvious advantages to the consumer. These advantages include the ease of installation and the fact that it is not necessary to drill a hole in the vehicle. Many efforts in designing effective window mounted antenna systems have been disclosed in the patent literature. The majority of these are capacitively coupled systems. With the introduction of PCNIPCS (Personal Communication Network/Personal Communication Services), capacitive coupling becomes troublesome due to the doubling of the frequency and bandwidth requirements.
U.S. Pat. No. 4,089,817 to Kirkendall illustrates one capacitively coupled antenna system for use with half wavelength antennas. U.S. Pat. No. 4,839,660 to Hadzoglou discloses another capacitive coupling system--this one for use with a bottom radiation element of between 1/4-wavelength and 1/2-wavelength. (Hadzoglou's bottom radiation element cannot be a full dipole because of the high transition impedance sensitivity at a 1/2-wavelength.) U.S. Pat. Nos. 4,992,800 to Parfitt, 4,857,939 to Shimazaki, and 4,785,305 to Shyu, follow similar principles, all involving LC matching networks and capacitive coupling through the vehicle glass.
Capacitive coupling systems (e.g conducting patches mounted on opposing sides of window/windshield glass to form a capacitor coupling RF energy therethrough) suffer from a number of disadvantages, summarized below:
1) To present a substantially capacitive reactance, the coupling patches cannot be large in comparison with the operating wavelength. High impedance coupling (several hundred ohms) results, leading to losses through the leakage of electrical field at high frequencies.
2) In the higher UHF bands, such as the 1.5-2.4 GHz frequencies used for PCN/PCS/ISM services, even a "small" coupling patch does not behave as a lumped capacitor element. Considering the thickness of vehicle glass and stray capacitance, the coupling circuit can bypass the signal and make it more difficult to match the high impedance of the antenna to a 50 ohm system.
3) The high impedance coupling afforded by capacitive coupling creates a moisture sensitive structure. U.S. Pat. No. 4,764,773 to Larsen describes a better coupling structure to improve performance in the presence of moisture, but it is still subject to patch size limitations.
In addition to problems with capacitive coupling systems, the conventional collinear array antenna presents problems of its own. For example, such antennas do not have uniform current distributions; the lower section of the whip exhibits the strongest radiation. In most vehicle mounting situations, the lower section of the whip is blocked by the roof of the vehicle, causing severe pattern distortion and deep nulls. This situation becomes worse in the 1.7-2.4 GHz PCS/PCN/ISM bands simply because the length of the radiator is less than half that at the 800 MHz cellular band due to the more than doubling of the frequency. To reduce this problem, elevated feed systems are sometimes employed. But antennas with elevated feeds are not easily matched for broadband operation (e.g. up to 11% for DCS-1800). Moreover, such elevated feed systems often present a low impedance (e.g. 50 ohms) at the through-glass coupling point, limiting the through-glass coupling techniques that can be used. If traditional capacitive coupling is employed, a matching network must, somewhere, be employed to transform impedances. Such matching networks tend to have prohibitive losses at the high UHF frequencies of the PCN/PCS/ISM services (typically 4-6 dB).
U.S. Pat. No. Reissue 33,743 to Blaese describes a different capacitively coupling system for coupling a coaxial cable through the glass. But at the PCN/PCS/ISM frequencies, the quarter-wave antenna employed by Blaese would be only 1.7 inches long--completely below the roof line of a vehicle, causing severe pattern distortion and deep nulls. U.S. Pat. No. 4,939,484 to Harada discloses a coupler comprising helix cavities for through-glass coupling. While suitable for use in the 800 MHz cellular band, this arrangement has a number of drawbacks when scaled to the 1.8 GHz PCS band. For example, the coupling aperture becomes undesirably small. Moreover, the helix Q is relatively small due to the size of the helix. Still further, the coupling coefficient is too small to provide adequate coupling over the wide (11%) PCS band. Manufacturing and tuning are complicated by the high frequency and the coupler's complex 3D structure.
Most of the above-discussed drawbacks are present with other through-glass couplers described in the prior art (notwithstanding the prior art's laudatory assertions of their general applicability at frequencies above the 800 MHz cellular band).
Accordingly, there is a need for an improved method of through-glass (or through other dielectric) coupling for use at gigahertz frequencies.
One attempt to meet this need is disclosed in my U.S. Pat. No. 5,471,222. The disclosed system employs microwave cavities containing high Q ceramic resonators, with RF signals fed through the glass by a pair of TE 01 δ mode dielectric resonators.
The disclosed approach is highly efficient, with an insertion loss of 0.5dB (through 5 mm automobile glass at 1.8 GHz) attainable with careful tuning. However, this design is expensive to manufacture and is sensitive to detuning in the field.
Another attempt to meet this need is disclosed in my U.S. Pat. No. 5,451,966. In that system, a rectangular slot coupling scheme replaces the expensive ceramic couplers of my '222 patent. (The concept of slot coupling on a microstrip antenna (MSA) is understood to have originated with Pozar. See, e.g., his publication "Improved Coupling for Aperture Coupled Microstrip Antennas," Elec. Lett., Vol. 27, pp. 1129-1131, June, 1991.) Slot coupling is used to overcome the narrow band nature of MSA. A "doggie bone" type of slot, suggested by Pozar, significantly increases the magnetic polarisability on the slot, allowing a short slot to provide the necessary coupling while at the same time keeping the backward emissions low. Pozar and other researchers' work has generally been limited to numerical solutions of slot-fed microstrip antennas and multilayer arrays on a ground plane. But the bandwidth advantages of this type of MSA can be used to enhance the concept of the planar slot-cavity coupler. Furthermore, recent progress in low cost, high performance microwave printed circuit board material has brought about the opportunity to make this type of antenna system affordable for commercial applications. Based on this MSA process, a "doggie bone" type slot coupled antenna system was developed with the coupling element etched on low loss Teflon™ PCB and it has proven to be quite successful in the field.
Unexpectedly, I have discovered that a simpler and less costly coupling technique is capable of achieving the same superior performance of the previous arrangement, while at the same time providing various advantages over the rectangular slot approach.
One issue in the existing slot-coupled approach is cascade coupling, which can be diagrammed as:
cable→microstrip→slot→glass→
slot→microstrip→i.m.n.→antenna
Another issue is the so-called "MSA effect." The E field excited by a rectangular slot is always distributed perpendicularly to the slot, making the opposite coupler an antenna patch. The inner and outer PCB, however, must be limited in size to satisfy the resonant frequency. This introduces a substantial loss inherent in all slot-fed variations of the MSA.
Moreover, radiation always occurs at the edges of the resonant direction of the patch (i.e. perpendicular to the slot) by means of an equivalent magnetic current represented as M=EXn. The presence of a larger ground plane supports the tangential portion of the E field. When a rectangular slot is used as a glass coupler, the edge E field still exists, leading to a radiation loss. In the previous art, the lengths of the two ground planes on the PC board are selected and aligned in the resonant direction to form a glass mount antenna. The MSA effect is obviously observed.
Finally, to achieve a high coupling coefficient, long slot lengths arguably should be used. But this presents the problem of increasing backwards radiation.
In accordance with the preferred embodiment of the present invention, through-glass coupling is achieved with an annular ring type aperture coupling arrangement. One advantage of this approach over rectangular slot coupling is that it raises the coupling coefficient, which is important for coupling through a relatively thick dielectric wall. Another advantage is that the radial distribution of the E field from an annular ring aperture tends to increase the aperture coupling and reduce edge coupling.
The annular ring aperture coupler of the present invention also aids the issue of backwards radiation from the slot itself. FIG. 2 presents an estimated radiation resistance of an annular ring slot according to the preferred embodiment. For a rectangular slot, as mentioned by Pozar and other researchers, the backwards radiation of a slot-fed MSA can effectively be cut by shortening the slot length and end-loading the slot to retain a sufficient coupling coefficient. This technique can also be applied to glass couplers; An annular ring is the complementary element of a small loop antenna and, like the loop antenna, presents a low radiation efficiency, but this effect is here turned to advantage by reducing backwards radiation. A larger E field aperture can be achieved, with less MSA effect. An impedance matching network is avoided by connecting the CPW line directly to the center resonant element instead of using a transition coupling scheme, as described in the prior art. With this improvement, the i.m.n. stays in the same layer as the resonant element, facilitating fabrication (e.g. a single layer PCB or simple stamped metal parts).
By the foregoing arrangement, the loss mechanisms of the prior art are largely eliminated, leaving just the dielectric loss of the vehicle glass. Results like that of the ceramic coupler arrangement are thus achieved, without its cost, manufacturing, and detuning drawbacks.
One object of the preferred embodiment is thus the provision of a cost effective glass mount antenna system operating at frequencies higher than the existing cellular band.
Another object is the provision of a through-glass coupler that is simpler than the prior art, facilitating mass production and lowering manufacturing costs.
Another object is the provision of a through-glass coupler operating at relatively low impedance while enabling a high feeding point and providing broadband operation.
Another object is the provision of a through-glass coupler that minimizes loss factors present in the prior art.
Another object is the provision of a through-glass coupler that reduces backward radiation while maintaining a high coupling coefficient.
Another object is the provision of a through-glass coupler that reduces edge-coupling effects of the prior art.
The foregoing and other objects, features and advantages of the present invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of an antenna system employing annular ring aperture coupling according to one embodiment of the present invention.
FIG. 2 shows an estimated radiation resistance of the annular ring slot employed in FIG. 1.
FIGS. 3A and 3B illustrate a first portion of the through-glass coupler employed in FIG. 1.
FIG. 4 illustrates a second portion of the through-glass coupler employed in FIG. 1.
FIG. 5 shows an equivalent circuit of the antenna system of FIG. 1.
FIG. 6 is a graph showing typical insertion loss of the FIG. 1 coupler, and the resultant VSWR characteristics.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an exploded view of an antenna system 12 employing an annular ring aperture coupling arrangement according to one embodiment of the present invention. Antenna system 12 includes an antenna assembly 100, an outside assembly 66, an inside assembly 15, and a feed cable assembly 20.
The antenna assembly 100 comprises a collinear array with an upper 1/2- to 5/8-wavelength radiator 101, and a 1/2-wavelength lower radiator 106. The two radiators are separated by an air-wound phasing coil 105. This array is desirably encapsulated with a low loss plastic material through a molding process. At the bottom of this molded plastic is formed a threaded coupler 107, which screws onto a corresponding threaded post 108, allowing the antenna (whip) to be removed from the antenna assembly, e.g. at a car wash. Post 108 is formed on a conductive swivel member 110, which engages with a corresponding conductive swivel part 115 to set the angle of the antenna (using set screw 120). A ball 102 is positioned on the end of the upper element to improve bandwidth and enhance physical safety.
Normally, a 1/2-wavelength radiator has a sharp resonant impedance characteristic, significantly limiting its bandwidth A 5/8-wavelength radiator is better, but some energy is consumed at the out-of-phase section near the feeding point, and the radiation resistance is too low when the feeding point is "bulky." A 1/2-wavelength lower section has many advantages over its 1/4- or 3/8-wavelength counterpart as described in Parfitt's early patents. First, the dependency on the ground plane is significantly reduced. For the same reason, feed line emissions are cut since less current flows on the outside conductor of the feed cable. Also, emissions to the passenger compartment are much less, compared to that from a 1/4- or 3/8-wavelength lower sections, since relatively little current is present at the bottom of the antenna (it is relatively "cold"). Another important feature is that a 1/2-wavelength lower section effectively raises the feed point above the roof line of the vehicle, creating a more uniform radiation pattern.
In Parfitt's early patents, there is a high impedance formed at the feed point, making the antenna moisture sensitive and reducing its bandwidth. Further, it may be noticed that a 3/8-wavelength lower section is used in Parfitt's recent work (U.S. Pat. No. 4,992,800) to improve performance. It has been found that a 1/2-wavelength section with a small length/diameter ratio, or a "bulky"feeding point, can be easily matched. The outside diameter of the lower radiating element is selected to satisfy the bandwidth as well as to preserve cosmetic appearance and enhance rigidity. A metal rod and a "bulky" swivel assembly smooth the impedance significantly. Therefore, a broadband 1/2-or 5/8- over 1/2-wavelength collinear array can be realized. For best results, an approximately 1/2-wavelength lower section is utilized in the preferred embodiment to minimize the sensitivity.
The illustrated outside assembly 66 includes a housing 60, a printed circuit board 80, and double-sided adhesive tape 71 for mounting the PC board/housing to a window 58.
Housing 60 includes the swivel part 115 insert-mounted therein (thereby providing good rigidity and moisture isolation). Housing 60 can be made of a thermal plastic such as LEXAN™ (a GE material) for rigidity and UV stability. PC board 80 (discussed below) is bonded or thermo-pressed into the plastic housing 60, and is covered by the adhesive tape 71. The tape 71 is commercially available from 3M; a thickness of 0.045 is used in the illustrated embodiment. Holes 86 in circuit board 80 are furnished for mounting and reducing dielectric loss.
The inside assembly 15 includes a housing 10, a second printed circuit board 40, and double-sided adhesive tape 57 for mounting the PC board/housing to the window 58.
Housing 10 is made of thermal plastic such as ABS. Again, the PC board 40 is bonded or thermo-pressed onto the plastic housing 10 (through holes 43, 44 and 45) and is covered by the adhesive pad 57.
Cable assembly 20 can employ any type of popular low loss coaxial cable. One end of cable 20 is terminated at the inside coupling housing 10. More particularly, a center conductor 24 of the cable is soldered to a microstrip line member 47 on the PCB 40. The coaxial cable braid, which is split in two bundles, illustrated as 22 and 23, are soldered to ground 46 (FIG. 3B) on the PC board member 40.
In the illustrated system, the remote end of the coaxial cable 20 is connected to an RF connector 21 for connection to a radio transceiver.
FIGS. 3A and 3B illustrate the inside coupling member 40. As indicated, shield (braid) members 22, 23 of the feed cable 20 are soldered to ground 46 on PC board 40. Ground 46 is connected by plated vias 51 to a ground plane 41 on the opposite side of the board (FIG. 3A). This construction facilitates assembly and soldering in a production line. Trace members 47, 48, 49 and 50 (FIG. 3B) are microstrip lines, forming an "Anchor" type impedance matching network and a transition coupling between element 39 on the glass side of board 40, and the feed line 20.
Outside the glass, facing the FIG. 3A circuit board, is the surface of PC board 80 shown in FIG. 4. This surface includes an annular slot 87 defined between copper-clad regions 81 and 82. Along with a microstrip feeding line 84, a planar cavity is constructed. The slot 87 is designed to have a width to length ratio of about 0.1 to satisfy the requirement of at least 11% bandwidth. The inside feeding microstrip line 84, which is typically 50 ohms, is extended across the slot 87 by 5-7 mm in the preferred embodiment to obtain proper impedance matching.
Trace 84 serves as a high impedance CPW section which impedance matches to the antenna element 100. More particularly, one end of trace 84 is connected (by soldering at point 85) directly to an antenna base member 70, and the other end is attached to the annular ring (patch) member 82. Notches 83 adjacent trace 84 serve to tune the electrical length of the CPW line 84. By this arrangement, single layer layout is used to simplify the structure. It will be recognized that the illustrated conductive surfaces cooperate to form an annular ring slot resonant circuit.
FIG. 5 shows an equivalent circuit. Since the aperture structure is a quasi-open resonant system, it is necessary to use low loss material to reduce the excessive loss incurred by the feeding line and impedance matching circuit.
Several transition coupling techniques between the annular aperture and the cable feeding system were investigated and compared for system optimization. One prior art method, disclosed in Bahl et al, Microstrip Antennas (1980), places a microstrip line across the annular ring slot and extends to a certain length. Unfortunately the resulting frequency response is quite sharp and the coupling coefficient is not sufficient for a dielectric comprising 4-6 mm of glass with the associated pair of adhesive tapes. The illustrated tuning circuit thus was developed and it was found that this "Anchor" arrangement of microstrip line provides a sufficient coupling coefficient while at the same time providing the bandwidth required by PCN/PCS. (The basic idea is to expand the bandwidth by a double tuned resonant circuit; keep a maximum E field intensity at the annular ring portion; and distribute it evenly.)
It was found that the illustrated embodiment is not as sensitive to the size and shape of the printed circuit board structures as the prior art. This implies a reduction of edge coupling found in prior art, rectangular slot approaches. Still, certain restrictions apply. The length of the PC boards is chosen to be slightly bigger than a free space 1/4-wavelength but less than a waveguide 1/2-wavelength, in order to avoid resonance at the operating frequency when the adhesive-glass-adhesive dielectric wall are taken into account.
The lengths of the inside and outside annular ring slots are selected to avoid resonance in the desired operational band. The annular rings provide sufficient aperture, by themselves, for coupling; no loading is required. The "Anchor" coupling transformer assures that maximum current occurs at the annular aperture-resonant slots at the individual operating frequency. When two of the aperture resonant system are placed face-to-face together, the strongest coupling occurs, since the magnetic polarisability is concentrated on the slot aperture. The presence of the glass wall and the adjacent resonant circuit changes the resonant frequency of the entire system and pulls the resonant frequency back to the desired operating frequency even when they are non-resonant circuits at the operating frequency individually.
The upper half of FIG. 6 shows the transmission loss of a pair of prototype couplers measured with 50 Ohm test cable used with two 1 mm adhesive tapes on each side of a piece of automobile glass having a thickness of about 4 mm. It is noticed that no spurious responses are found at adjacent communication bands. A bandpass characteristic is thus achieved with this simple arrangement. Cable loss is calibrated out for accuracy. It is clear that a low impedance coupling is achieved. The lower chart is the typical VSWR of a complete antenna system tested with only 9" RG-58 cable so that the influence of the cable loss is negligible.
For lowest loss and flat response inside the usage band, the condition should be satisfied that k*Q L =1, where k is the coupling coefficient and Q L is the loaded Q of the resonant system. For PCN and the proposed U.S. broadband PCS, Q L is selected to equal 9 in order to ensure the needed bandwidth. k may be adjusted by tuning the "Anchor" elements. Q O should be high to minimize loss since the Q O /Q L ratio decides the overall coupling loss.
In order to minimize the losses contributed by the feed lines, the PC board (70, 80) material should be carefully selected. Rogers Corp.'s RO4003™ low cost microwave substrate is used in the preferred embodiment. G-10(FR-4) board and/or stamped metal elements can be used for further cost reduction. In this case, the substrate (printed circuit board or plastic) should be partially routed out to reduce dielectric loss since the E field is concentrated at the ring aperture.
Having described and illustrated the principles of my invention with reference to a preferred embodiment, it should be apparent that the invention can be modified in arrangement and detail without departing from such principles. Accordingly, I claim as my invention all such modifications as may come within the scope and spirit of the following claims, and equivalents thereto. | A low cost window-mounted antenna system for mobile communication systems operating at frequencies in and above the 1.5 GHz band includes an annular ring aperture coupler fabricated on printed circuit boards on each side of the window, with a microstrip line etched on each of the printed circuit boards. A collinear array-type whip antenna with a 1/2-wavelength lower section is used with the coupler. A coplanar waveguide trace is printed on the outside coupling unit to form an impedance matching network for the active element. The RF signal is thus electro-magnetically coupled through the window. | 7 |
The present invention relates to a process of preparing an alkylene glycol.
BACKGROUND OF THE INVENTION
Alkylene glycols, in particular monoalkylene glycols, are of established commercial interest. For example, monoalkylene glycols are being used in anti-freeze compositions, as solvents and as base materials in the production of polyalkylene terephthalates e.g. for fibers and bottles.
The production of alkylene glycols by liquid phase hydrolysis of alkylene oxides is known. In commercial production the hydrolysis is performed without a catalyst by adding a large excess of water, e.g. 15 to 30 moles of water per mole of alkylene oxide. The reaction is considered to be a nucleophilic substitution reaction, whereby opening of the alkylene oxide ring occurs, water acting as the nucleophile. Because the primarily formed monoalkylene glycol also acts as a nucleophile, as a rule a mixture of monoalkylene glycol, dialkylene glycol and higher alkylene glycols is formed. In order to increase the selectivity to monoalkylene glycol, it is necessary to suppress the secondary reaction between the primary product and the alkylene oxide, which competes with the hydrolysis of the alkylene oxide.
One effective means for suppressing the secondary reaction is to increase the relative amount of water present in the reaction mixture. Although this measure improves the selectivity towards the production of the monoalkylene glycol, it creates a problem in that large amounts of water have to be removed for recovering the product. Removing this additional water increases production costs as it is energy intensive and requires large-scale distillation facilities.
The demand for monoalkylene glycols has risen significantly in recent years and further growth is expected on account of the increasing popularity of monoalkylene glycol derived products. Most existing commercial alkylene glycol production facilities already operate at or close to maximum (design) capacity. Therefore, to meet the increased demand more efficient methods of producing monoalkylene glycols are required.
In commercial thermal alkylene glycols production processes, the limiting factor on the amount of monoalkylene glycol production is frequently the distillation of water from the aqueous glycol reactor product, as removing the large amounts of water required for high selectivity is a relatively lengthy process. This is problematic as the distillation step acts as a bottleneck, restricting the overall amount of production.
One method of overcoming this problem would be to reduce the ratio of water to alkylene oxide employed in the process. However, this would also increase the relative yield of less desirable higher alkylene glycol products, and possibly necessitate an expansion of facilities to remove and purify the higher alkylene glycol products from the monoalkylene glycol product.
Due to the size and cost of distillation and purification apparatus required to remove water and/or higher glycols, increasing distillation capacity is in many cases neither a practical nor cost-effective solution. Accordingly, it would be advantageous if there was a flexible means with which to overcome this problem such that glycol production could be increased while retaining high selectivity to monoalkylene glycol products.
Catalytic processes for converting alkylene oxides to alkylene glycols have been investigated and catalysts capable of promoting a higher selectivity to monoalkylene glycol product at reduced water levels are known, (e.g. EP-A 015649, EP-A 0160330, WO 95/20559 and U.S. Pat. No. 6,124,508). For some catalysts, such as the quaternary phosphonium cation-containing catalysts of U.S. Pat. No. 6,124,508, it is mentioned that in order to save the catalyst it may be advantageous to subject the alkylene oxide feed stream to partial thermal hydrolysis before completing the hydrolysis catalytically.
SUMMARY OF THE INVENTION
The present invention is directed to a previously unconsidered use of a catalytic method of glycol production that enables production amounts to be increased while maintaining high selectivity to monoalkylene glycol product. Accordingly, the present invention is directed to a process of preparing an alkylene glycol which process comprises:—
i) reacting a respective alkylene oxide and water in a first reactor, ii) removing from the first reactor a reactor output mixture comprising an alkylene glycol and unreacted water, iii) transferring a proportion of the reactor output mixture to a distillation unit and a proportion of the reaction output mixture to a second reactor comprising a catalyst, iv) reacting the reaction output mixture in the second reactor with a further amount of the respective alkylene oxide, and v) transferring a reactor output mixture from the second reactor to a distillation unit.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a schematic depiction of a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention makes use of a catalyst in the second reactor to allow a further amount of alkylene oxide to be converted to alkylene glycol by reaction with water already present in the output mixture from the first reactor. In this way, overall yields of product may be increased with relatively little or no increase in the total amount of water employed in the process. This is possible as the catalytic reaction has a higher selectivity to monoalkylene glycol product at the same or a lower ratio of water to ethylene oxide than the thermal reaction.
Catalysts that may be employed in the present process are known in the art. Preferred catalysts are those comprising an ion exchange resin as a solid support, in particular the strongly basic (anionic) Ion exchange resin wherein the basic groups are quaternary ammonium or quaternary phosphonium. The ion exchange resins may be based on vinylpyridine, polysiloxanes, as well as other solid supports having electropositive complexing sites of an inorganic nature, such as carbon, silica, silica-alumina, zeolites, glass and clays such as hydrotalcite. Further, immobilized complexing macrocycles such as crown ethers, etc. can be used as well as a solid support.
Preferably, the catalyst is based on a strongly basic quaternary ammonium resin or a quaternary phosphonium resin. The catalyst is most preferably based on an anion exchange resin comprising a trimethylbenzyl ammonium group. Examples of commercially available anion exchange resins on which the catalyst of the present invention may be based include LEWATIT M 500 WS (LEWATIT is a trademark), DUOLITE A 368 (DUOLITE is a trademark) and AMBERJET 4200 (AMBERJET is a trademark), DOWEX MSA-1 (DOWEX is a trademark), MARATHON-A and MARATHON-MSA (MARATHON is a trademark) (all based on polystyrene resins, cross-linked with divinyl benzene) and Reillex HPQ (based on a polyvinylpyridine resin, cross-linked with divinyl benzene).
The anion exchange resin in the fixed bed of solid catalyst may comprise more than one anion. Preferably, the anion is selected from the group of bicarbonate, bisulfite, metalate and carboxylate anions.
When the anion is a carboxylate anion, it is preferred that the anion is a polycarboxylic acid anion having in its chain molecule one or more carboxyl groups and one or more carboxylate groups, the individual carboxyl and/or carboxylate groups being separated from each other in the chain molecule by a separating group consisting of at least one atom. Preferably the polycarboxylic acid anion is a citric acid derivative, more preferably a mono-anion of citric acid.
Most preferably the anion is a bicarbonate anion.
A solid catalyst which has given particularly good results when employed in the process of the present invention, is a catalyst based on a quaternary ammonium resin, preferably a resin comprising a trimethylbenzyl ammonium group, and wherein the anion is a bicarbonate anion.
The alkylene oxides used as starting materials in the process of the present invention, have their conventional definition, i.e. they are compounds having a vicinal oxide (epoxy) group in their molecules.
Preferred alkylene oxides are alkylene oxides of the general formula:—
wherein each of R 1 to R 4 independently represents a hydrogen atom or an optionally substituted alkyl group having from 1 to 6 carbon atoms. Any alkyl group, represented by R 1 , R 2 , R 3 and/or R 4 , preferably has from 1 to 3 carbon atoms. Optional substituents on the alkyl groups include hydroxyl groups. Preferably, R 1 , R 2 , and R 3 represent hydrogen atoms and R 4 represents a non-substituted C 1 –C 3 -alkyl group and, more preferably, R 1 , R 2 , R 3 and R 4 all represent hydrogen atoms.
Examples of alkylene oxides which may conveniently be employed include ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane and glycidol. The alkylene oxide is preferably ethylene oxide or propylene oxide; ethylene glycol and propylene glycol being alkylene glycols of particular commercial importance. Most preferably the alkylene oxide of the present invention is ethylene oxide or propylene oxide and the alkylene glycol is ethylene glycol or propylene glycol.
The first reactor of the present invention may conveniently be a conventional thermal reactor as is widely used for the hydrolysis of alkylene oxides to alkylene glycols, and the reaction conditions in the first reactor will generally be in accordance with those commonly used in thermal alkylene glycol production, e.g. a water/alkylene oxide ratio of 15 to 30 moles of water per mole of alkylene oxide, a temperature in the range of from 150 to 250° C., and a pressure in the range of from 500 to 5000 kPa. The first reactor may comprise a single thermal reactor or two or more thermal reactors arranged in either a parallel or series configuration.
It is an advantageous feature of the present invention that by varying the amount of first reactor output mixture directed to the second reactor it is possible to vary the output of mono-, di- and trialkylene glycol product produced to suit demand. For example, when a higher proportion of monoalkylene glycol product is required, the proportion of first reactor output mixture routed to the second reactor may conveniently be increased. Conversely, if it is desired to produce a larger quantity of di- or trialkylene glycol, the amount of output mixture fed to the second reactor may be adjusted appropriately. As will be understood by those skilled in the art, the present process may further comprise suitable detection and adjusting means to allow the proportion of reaction output mixture fed to the second reactor to be optimized to attain the required product ratios.
In general, the proportion of reaction output mixture from the first reactor transferred to the second reactor is preferably in the range of from 25 to 100% wt of the total amount of first reactor output mixture, more preferably 30 to 99% wt, even more preferably 35 to 70% wt, and most preferably 40 to 60% wt.
The second reactor of the present invention may comprise a single catalyst-containing reactor, or a reactor system comprising two or more catalyst-containing reactors arranged in either a parallel or series configuration. The conditions employed in the second reactor may vary depending on the catalyst employed, the constituents of the reactor output mixture fed to the second reactor, and the desired overall selectivity to mono-, di- and trialkylene glycol product. However, in general, the temperature in the second reactor will conveniently be in the range of from 60 to 150° C., more conveniently 70 to 100° C.; and the pressure conveniently in the range of from 500 to 5000 kPa, more conveniently 500 to 3000 kPa. Moreover, the optimal liquid hourly space velocity of the reactants through the reactor will preferably be in the range of from 0.5 to 15 l/l·h, more preferably 1 to 10 l/l·h.
In certain embodiments of the present invention it may be beneficial to add carbon dioxide to the second (catalytic) reactor. Such carbon dioxide may conveniently be added directly to the reactor or it may be added to the alkylene oxide feed. If carbon dioxide is to be added, the amount of carbon dioxide added may be varied to obtain optimum performance in relation to other reaction parameters, in particular the type of catalyst employed. However the amount added will preferably be less than 0.1% wt, more preferably less than 0.01% wt, based on a total amount of reactants in the second reactor.
When the second reactor comprises a fixed bed reactor, the process of the present invention may be operated in up-flow or down-flow operation. Down-flow operation is preferred. The reactor may be maintained under isothermal, adiabatic or hybrid conditions. Isothermal reactors are generally shell- and tube reactors, mostly of the multitubular type, wherein the tubes contain the catalyst and coolant passes outside the tubes. Adiabatic reactors are not cooled, and the product stream leaving them may be cooled in a separate heat exchanger. Under certain chosen circumstances it may be advantageous to use a recycle reactor in which part of the outlet of the reactor containing the catalyst is recycled back to the inlet of the same reactor. In order to accommodate any swelling of the catalyst during operation, the reactor volume can advantageously be greater than the volume occupied by the catalyst therein, for example 10 to 70 vol % greater.
The present invention provides a highly flexible means of alkylene glycol production. As well as allowing glycol to be produced at a higher rate, the output of mono-, di- and trialkylene glycol product produced may be conveniently adjusted to suit demand. Further, the invention may very conveniently be implemented in existing alkylene glycol production facilities to increase production rates without compromising selectivity.
The invention is now further described with reference to the FIGURE. In the preferred process depicted in the FIGURE, water and alkylene oxide are fed to a first reactor 1 wherein they are reacted at elevated temperature to produce a reactor output mixture comprising alkylene glycol, unreacted water and optionally some unreacted alkylene oxide. The reactor output mixture from the first reactor is then divided into two streams such that a proportion of the mixture is fed to a distillation unit 3 , while a proportion is fed, via heat exchangers 5 , to a second reactor 2 containing a catalyst bed 4 .
In the second reactor 2 , the reactor output mixture from the first reactor is reacted with a further amount of alkylene oxide, and optionally water. In the preferred process of FIG. 1 , the reaction output mixture from the second reactor 2 is transferred to the distillation unit 3 via a post-reactor 6 and heat exchangers 5 .
It is not an essential feature of the present invention that the same distillation unit be employed to remove water from both the reactor output mixture from the first and second reactors. However, in certain applications, in particular where the present process is implemented in an existing glycol production facility to overcome a bottleneck problem, it is preferred that the reactor output mixture from the second reactor is transferred to the same distillation unit to which a proportion of the reactor output mixture from the first reactor is transferred.
The distillation unit may comprise any distillation apparatus known in the art for the removal of water from alkylene glycols. Conveniently, the distillation unit may be a unit already present in an existing glycols production facility, as is particularly advantageous when the present invention is implemented to increase the production capacity of an existing plant. Such distillation units will typically comprise a multiple effect evaporation system with subsequent vacuum distillation. After water removal the monoalkylene glycol product may then be purified in a purification column wherein monoalkylene glycol product is extracted as a side stream, while the bottom stream is sent to further purification columns for isolation of higher alkylene glycol products.
In accordance with the present invention post-reactor(s) 6 may be employed, for example as depicted in the preferred embodiment of FIG. 1 , to ensure complete conversion of all starting material alkylene oxide to glycol product and/or to remove any contaminants such as amines or phosphines that may have leached into the reaction output mixture from the catalyst. Where necessary, an effective way of removing such contaminants is to pass the output mixture through a post-reactor comprising a strongly acidic ion exchange resin, for example of an exchange resin of the sulfonic type, e.g. as available under the trade names AMBERLYST 15, AMBERJET 1500H, AMBERJET 1200H, DOWEX MSC-1, DIANON SK1B, LEWATIT VP OC 1812, LEWATIT S 100 MB, LEWATIT S 100 G1.
The process of the present invention may be carried out in batch operation. However, in particular for large scale embodiments it is preferred to operate the process continuously.
The present invention further provides a process of permitting a variable rate of alkylene glycol(s) production from alkylene oxide and water, which process comprises use of a catalytic conversion reactor in combination with a thermal conversion reactor. A thermal conversion reactor is a reactor wherein the reaction may be promoted by heat alone and does not contain a catalyst. A catalytic conversion reactor is a reactor comprising a catalyst capable of promoting the conversion of alkylene oxide to alkylene glycol(s). By variable rate of alkylene glycol(s) production it is meant that the overall amount of monoalkylene glycol produced may be increased as compared with the use of a thermal reactor alone without any loss in selectivity. In said process, the thermal and catalytic conversion reactors may be positioned in either a series or parallel configuration. Preferably the reactors are in a series configuration, more preferably with the catalytic conversion reactor positioned down stream of the thermal conversion reactor.
The present invention will be further understood from the following illustrative example.
EXAMPLE 1
A feed composition corresponding to the reactor output from a thermal reactor was reacted with a further amount of ethylene oxide in the presence of a catalyst in an adiabatic reactor.
The catalyst employed in Example 1 comprised a quaternary ammonium resin and a bicarbonate anion. The catalyst was prepared by washing an ion exchange resin of the quaternary ammonium type in the chloride form (AMBERJET 4200, ex-Rohm & Hass, exchange capacity 1.3 meq/ml) as follows: I) 150 ml of wet catalyst was slurried in a water filled glass tube, ii) the chloride anion was exchanged by treatment with a sodium-bicarbonate solution (10 times molar excess in 2500 g of water) for approximately 5 hours (Liquid Hourly Space Velocity=4 l/l·h), and iii) the exchanged resin was washed with 1200 ml of water for 2 h (LHSV=4 l/l·h). In the resulting catalyst the chloride anions from the AMBERJET 4200 had been almost completely exchanged with the desired bicarbonate anions, the final chloride content of the catalyst being 32 ppm.
The adiabatic reactor comprised a reactor tube filled with catalyst and fitted inside a stainless steel pipe. The reactor tube had an internal diameter of 20 mm and a length of 24 cm. The reactor tube was insulated with a Teflon layer placed between the tube and the stainless steel pipe. The stainless steel pipe was electrically heated to compensate for heat loss only. In operation the feed was preheated prior to mixing with the additional ethylene oxide to achieve the required inlet temperature.
The feed stream entering the reactor consisted of 17.1% wt monoethylene glycol, 2.1% wt diethylene glycol, 77.9% wt water, 3% wt ethylene oxide and had a carbon dioxide content of 7 ppm. The contents of the above feed stream correspond to the output of a thermal reactor to which an additional amount of ethylene oxide has been added, and were determined on the basis of an input to the thermal reactor of 83% wt water and 14% wt ethylene oxide, a selectivity to monoethylene glycol in the thermal reactor of 87.4%, and the addition of a further amount of 3% wt of ethylene oxide to the output of the thermal reactor, all weights based on the total amount of water and ethylene oxide employed in the process.
The adiabatic reactor was loaded with 42 ml of wet catalyst and the feed was pumped at 1000 kPa pressure into the reactor. The liquid hourly space velocity (LHSV) through the reactor was 4.7 l/l·h, the inlet temperature was from 84–85° C. and the outlet temperature from 91–93° C. The reactor was run continuously and the reactor output periodically analyzed by gas chromatography to determine the conversion of ethylene oxide in the catalytic reactor and the selectivity to monoethylene glycol in the total mixture. The results are shown in Table 1.
TABLE 1
1 EO Conversion in
2 Selectivity to MEG
Run
catalytic reactor
in reaction mixture
(hour)
(%)
(%)
127
95.4
88.7
176
96.3
88.8
201
96.3
88.8
254
96.6
88.6
377
92.3
88.6
460
93.6
88.6
621
95.5
88.7
710
95.5
88.7
780
92.9
88.7
892
93.3
88.8
1055
96.5
88.7
1151
94.4
88.6
1218
94.6
88.7
1284
96.0
89.1
1373
95.6
88.9
1445
95.0
88.8
1616
93.9
88.6
1704
92.8
88.8
1886
92.6
88.6
2024
91.1
88.5
2190
89.3
88.5
2281
90.6
88.5
2392
87.3
88.4
2554
88.4
88.4
2556
87.6
88.2
1 EO conversion (mol %) = 100 × (MEG + 2DEG + 3TEG + 4TTEG)/(EO + MEG + 2DEG + 3TEG + 4TTEG)
2 MEG selectivity (mol %) = 100 × (MEG)/(MEG + 2DEG + 3TEG + 4TTEG)
From Table 1 it can be seen that the overall selectivity to monoethylene glycol (MEG) in the total reaction mixture has been improved from 87.4% to in excess of 88% despite the addition and conversion of the extra amount of ethylene oxide (EO). Accordingly, Example 1 demonstrates the capability of a catalytic reactor, when used in accordance with the present invention, to de-bottleneck a thermal monoethylene glycol plant with no loss in overall selectivity. | A process of preparing an alkylene glycol which process involves: i) reacting a respective alkylene oxide and water in a first reactor, ii) removing from the first reactor a reactor output mixture comprising an alkylene glycol and unreacted water, iii) transferring a proportion of the reactor output mixture to a distillation unit and a proportion of the reaction output mixture to a second reactor containing a catalyst, iv) reacting the reaction output mixture in the second reactor with a further amount of the respective alkylene oxide, and v) transferring a reactor output mixture from the second reactor to a distillation unit. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a lock mechanism and, in particular, to a locking box having said lock mechanism.
2. Brief Statement of the Prior Art
Locking mechanisms having detenting balls which must be moved into or out of detenting positions to enable operation of the latch of the locking mechanism have been described in prior patents. U.S. Pat. No. 1,714,019 discloses a padlock in which a ball is interposed between the hasp and latch members to permit movement of the latch out of its hasp engaging position. The ball is transported to its operative, detenting position through a labyrinth, thereby defining an enabling sequence of lock positions.
U.S. Pat. No. 1,733,772, discloses a locking box having a keeper bolt which engages a hasp. The cover of the box receives the keeper bolt and has two obstructing, sliding bolts that are retained in obstruction to movement combination the keeper bolt by a plurality of balls. The enabling combination of positions for this box results in movement of the balls out of their detenting positions, freeing the obstructing rods for movement out of the path of the keeper bolt, and permitting movement of the keeper bolt to release the hasp.
While the aforedescribed attempts have been made to provide a lock mechanism requiring movement through a preselected sequence of positions, no attempt has been made to provide a maximum complexity of such a lock mechanism nor to provide interchanging of the combination of such a lock mechanism.
BRIEF STATEMENT OF THE INVENTION
This invention comprises a lock mechanism having a retainer or hasp member which is captured by a latch means that comprises a pair of opposed hooks, one carried on an actuation member and the other carried on a travel latch member that is yieldably interconnected thereto whereby depression of the actuation member moves the hooks in unison and fails to release the hasp member. The actuation mechanism also includes a fixed position abutment with an opposed, moveable abutment carried on the travel latch member but separated therefrom by an actuation cavity. The actuation cavity is in communication with a labyrinth that defines a three-dimensional torturous passageway for a ball. When the latter is advanced through the torturous passageway by movement through an enabling combination of preselected, sequential positions, the ball drops into the actuation cavity where it obstructs the movement of the latch member. In this position, depression of the actuation member with its dependent hook spreads the opposed hooks and releases the hasp member.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described by reference to the drawings of which:
FIG. 1 is a perspective view of the locking box of the invention;
FIG. 2 is a view along lines 2--2 of FIG. 1;
FIG. 3 is a view along lines 3--3 of FIG. 2;
FIG. 4 is a view along lines 4--4 of FIG. 2;
FIG. 5 is a view along lines 5--5 of FIG. 4;
FIG. 6 is a view similar to that of FIG. 5;
FIG. 7 is a perspective view of the labyrinth of the lock mechanism;
FIG. 8 is as view along lines 8--8 of FIG. 7; and
FIGS. 9-11 illustrate the detenting positions of the ball and actuation and latch members.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, the locking box of the invention is shown as a substantially cubic box 10 having a cover 12 received between the upper edges of the upright sidewalls. One of the walls, wall 14, has an aperture 16 which receives the end button 18 of an actuation member for the latch mechanism. Each of the corners of box 10 bears a characteristic indicia 20 which can be a letter, numeral or can be a distinct color to provide a coating of the corners of the box. Letter indicia from A to H are shown in FIG. 1.
Referring now to FIG. 2, there is shown a sectional elevational view along lines 2--2 of FIG. 1. As there shown, the box has opposite, upright sidewalls 22 and 24 secured to a bottom wall 26 which, together with cover 12, define an interior chamber 28 that is subdivided by a transverse internal wall 30 to form a lock mechanism chamber that receives the lock mechanism of the invention.
Cover 12 has a protruding post 32 that is received in aperture 34 in the top edge of wall 24 and, on its opposite edge, has a groove 36 which is traversed by a hasp pin 38.
Hasp pin 38 is captured by a pair of opposed hook members 40 and 42, which are shown in greater detail in FIG. 3. Hook member 40 is secured to actuation lever 44 which extends substantially the interior width of the box and which has opposite, lateral raised edges 46 and 48 that are received in grooves 50 and 52 of the partition 30 and wall 22, respectively. As apparent from FIG. 3, actuation lever 44 carries end button 18 which is received in aperture 16 of sidewall 14.
The undersurface of actuation lever 44 has a wide, transverse slot 54 and a communicating, smaller slot 56. Hook member 42 extends through slot 56 and is attached to latch travel member 58 which also has opposite, lateral raised edges that seat in grooves 50 and 52. The body portion 60 of latch travel member 58 is received within slot 54, partially filling the slot and a resilient member such as a compressible sponge or rubber plug 62 is placed between body portion 60 and face 64 in slot 54 of the latch actuation member 44, thereby providing a yieldable interconnection between these members. A second resilient plug 66 is mounted on the inboard end of actuation lever 44, bearing against the interior wall of upright side 68 to serve as a resilient bias for the actuation lever and dependent buttom 18.
The latch travel member 58 bears, on its undersurface, a dependent bracket 70 which has a travelling abutment surface 72 that is opposed to and spaced apart from a fixed position abutment 74 by an actuation cavity 76. As apparent from FIG. 2, fixed position abutment 74 is fixedly mounted on the inside wall of partition 30.
The actuation cavity 76 receives, in a manner hereinafter described in greater detail, a ball member which fills the cavity and restricts travel of the latch travel member 58 when button 18 is pushed; the relative displacement between the travel member and the actuation member 44 being permitted by the resilient yieldable plug 62. In this fashion, the opposed hook members 40 and 42 can be spread sufficient distance to release hasp pin 38. It is likewise apparent that when the actuation cavity 76 is vacant, the actuation travel member 58 is freely displaceable with displacement of actuation member 44, resulting in no separation of opposed hook members 40 and 42 and no release of hasp pin 38.
The remainder of the lock mechanism comprises a labyrinth that defines a torturous passageway which communicates with actuation cavity 76 and permits advance of the ball into this actuation cavity when the box 10 is through the enabling combination of preselected and sequential positions.
The labyrinth of the three-dimentional torturous passageway includes a subjacent transverse chamber 78 subdivided from a superior chamber 80 by a coextensive partition 82. The subjacent chamber 78 is subdivided by a transverse partition 84 which has an aperture 86; see FIG. 5, to provide a passageway for the actuation ball. The partition 82 has a plurality of ball passing apertures 87 and 88 and corner aperture 90 which appears in FIG. 4 and which provides passage for the ball member into the superior chamber 80. Chamber 80 is subdivided by a plurality of transverse partitions including partition 92 that has a corner aperture 94, shown in FIG. 5. The latter permits passage of the actuation ball into the succeeding chamber 95 which is defined by transverse partition 92 and a successive, transverse partition formed by partial wall 96 and a generally coplanar, opposed wall 98, is shown in FIG. 3. The space above wall 96 defines a ball passing aperture 100 that permits the actuation ball to move into the succeeding chamber 102 which is defined by the transverse wall 104 and the generally coplanar and cooperative wall 106 shown in FIG. 3. Wall 106 has a clearance space above partition 82 to provide a ball passage aperture 108 (shown in FIG. 3) whereby the actuation ball can pass into large cavity 110.
In the preferred embodiment, one of more of the transverse partitions in the subjacent chamber 78 or superior chamber 80 is removeable and can be reversed, end-to-end or inverted or can be interchanged with other transverse partitions. This flexibility is shown in FIGS. 5 and 6 where the partitions 84 and 92 are shown received in grooves 112 and 114 in wall 22. The partitions are secured in this position by a lock pin 116 which is received in a bore 117. The reversability of these partitions 84 and 92 is illustrated in FIG. 6 where partition 84 is reversed end-to-end and inverted to locate aperture 86 at the lower left rather than upper right, as shown in FIG. 5. In a similar fashion, partition 92 can be reversed or even replaced with an interchangeable wall thereby changing the enabling combination of positions.
The apertures 87 and 88 in partition 82 serve as bypass or shunt passageways for the actuation ball and provide a further complexity in the operation of the lock mechanism for successful passage of the actuation ball into the actuation cavity 76.
The travel of the actuation ball and interrelationship of the partitions of the labyrinth can be better described with reference to FIG. 7. As there illustrated, the labyrinth portion is shown as enclosed by imaginary planes which are formed by the interior sidewalls of the interior partition 30 and 30a, and opposed side interior surface of sidewall 22 and the interior walls of the opposite sides of the box. The actuation ball 118 is shown in solid lines in the actuation cavity and in broken lines in the subjacent chamber 78.
The first movement of the box is made to locate aperture 86 of partition 84 at a low point to permit ball 118 to roll through the aperture and into the small subjacent cavity 85. The box is then rotated to place aperture 90 of partition 82 at a lowermost elevation, permitting the ball 118 to pass into chamber 80 from which the ball can be passed through aperture 94 in partition 92 into chamber 95. The ball can then be passed through aperture 100 in the partition formed by coplanar partial walls 96 and 98 into chamber 100 from where the ball can be passed through aperture 108 formed by the coplanar partial walls 106 and 104.
As the ball enters the large cavity 110, it is important that button 18 of the actuation lever 44 not be depressed so that post 120, which is carried on the undersurface of travel member 58 will be in the illustrated position which obstructs aperture 88 and prevents the actuation ball 118 from passing through this shunting aperture, retaining the ball within chamber 110 rather than permitting it to fall into the subjacent chamber 78. Aperture 87 also serves as a shunting aperture that will permit the ball to fall into chamber 78 if the box is wrongly positioned with aperture 78 at the lower corner. The proper rotation of the box will cause the actuation ball to pass about post 122 carried on the undersurface of actuation member 44 from where the ball can be moved, again upon proper rotation of the box and pressing of button 18, into the actuation cavity 76 between fixed position abutment 74 and the abutment surface 72 of block 70 carried on the undersurface of the travel member 58.
FIG. 8 illustrates a preferred construction for the undersurface of the partition 82 which has raised lips 124 and 126 surrounding both apertures 87 and 88, thereby preventing bypassing the previously described labyrinth by dropping the actuation ball from cavity 78 directly into the large cavity 110.
FIGS. 9 through 11 illustrate the last steps of the unlocking of the box. The ball 118 is prevented from entering the actuation cavity 72 by post 122 that is carried on the undersurface of actuation member 44. To permit the ball to be received in this actuation cavity, it is necessary to press button 18 and move the actuation member 44 with its associated post 122 a sufficient distance shown in FIG. 10 to permit the ball 118 to be received in groove 126. The button 18 is then relaxed, permitting the resilient block 66 to return the button and move the actuation member 44 into the position shown in FIG. 11 where the ball 118 is free to fall into the actuation cavity 76, captured between the fixed abutment 74 and the abutment surface 72 on the moveable abutment 70 that is carried on the undersurface of the latch travel member 58. As apparent from FIG. 3, depressing the button 18 will move actuation member 44 relative to the obstructed travel member 58 and spread hook members 40 and 42 sufficiently to release hasp pin 38.
The enabling combination of box positions based on the FIG. 1 indicia is as follows, with each letter designating the high corner of the box: H, F, H, A, D, C, B, C, D, A, H, F, PUSH BUTTON 18, O, G, RELEASE BUTTON 18, H, PUSH BUTTON 18. The box can be relocked with the G corner uppermost, insert lever 12 and press button 18, then rotate the box to elevate corners C and B in sequence and push botton 18. When button 18 is pushed, the ball is freed to clear post 122 and falls into chamber 110. With the B corner elevated, the ball will roll to aperture 87 and fall therethrough, into subjacent chamber 78.
The three-dimensional character of the labyrinth provides a maximum of positions of the box and permits each corner to be assigned an indicium such as an identifying number or color to provide a maximum number of possible combinations. The complexity of enabling combination of box positions is further increased by the necessity to depress and release the actuating button at the proper timing.
The invention has been described with reference to the illustrated and presently preferred embodiment. It is not intended that the invention be unduly limitied by this description. Instead, it is intended that the invention be defined by the means, and the obvious equivalents, set forth in the following claims. | There is disclosed a lock mechanism requiring movement through an enabling combination of preselected, sequential positions for operation. The lock mechanism is preferably embodied in a locking box and includes a latch formed with a pair of opposed hooks that capture a retainer of the box cover. The opposed hooks are carried on separate members yieldably interconnected. Release of the lock requires positioning a ball in an actuation cavity to block movement of one of the members, thereby permitting the hooks to be separated, releasing the retainer pin carried by the box cover. The ball is positioned in the actuation cavity by advance through a torturous passageway of a three-dimensional labyrinth within the box. Passageway defining partitions of the labyrinth have apertures at preselected locations to provide the desired, preselected sequential combination of positions. The partitions are removeable, reversible and/or interchangeable to permit changing of the combination and can have bypass apertures to further increase the complexity of the enabling combination of positions. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to wireless devices, such as radio-frequency identification (RFID) tags, and, in particular, to methods of quickly estimating the cardinality of a set of wireless devices. i.e. the number of devices in the set.
2. Description of the Related Art
A common problem that arises in any RFID deployment is the quick estimation of the number of tags in a field, up to a desired level of accuracy. Prior work in this area has focused on the identification of tags, which takes a relatively long time and is unsuitable for many situations, especially if the tag set is dense or highly dynamic.
Radio-frequency identification (RFID) tags are being used in diverse applications in everyday scenarios, ranging from inventory control and tracking to medical-patient management, and are appearing ubiquitously in increasingly-large numbers. The key driver behind this widespread adoption is the simplicity of the tags, which enables relatively low (nearly zero) cost at high volumes. The tags themselves vary significantly in their capabilities, from “dumb” or passive tags that merely transmit a particular bit-string when probed by a reader, to “smart” or active tags that have their own CPUs, memories, and power supplies. Passive tags are designed to have a relatively long life and, hence, do not use any on-board energy sources for transmitting data. Rather, they derive the energy needed for transmission from a probe signal sent by a reader node. This probe signal can be transmitted, e.g., via magnetic coupling (called near-field), or electro-magnetic coupling (called far-field). The latter has a much larger range and is designed to read hundreds of tags at a time, while the former typically has a range of less than 1 meter and, hence, is used to read less than 1 to 5 tags at a time.
RFID tags can be generally classified into passive tags, semi-passive tags, and active tags. Active and semi-passive tags have their own power sources, typically in the form of batteries. However, semi-passive tags do not use their power source for transmission, but instead use it primarily to drive other on-board circuitry. Nearly all current RFID deployments around the world involve passive and semi-passive tags. A sensor mote (a wireless transceiver that is also a remote sensor) can be classified as being an active tag.
RFID tags are often used to label items. Hence, identifying these items is normally the main goal of such an RFID system. The general idea is as follows: the reader probes a set of tags, and the tags reply back. There are many algorithms that enable identification, which can be classified into two categories: probabilistic and deterministic. Since RFID devices are relatively simple and operate in a wireless medium, collisions will typically result whenever a reader probes a set of tags. The identification algorithms use anti-collision schemes to resolve such collisions.
In probabilistic-identification algorithms, a framed scheme dubbed an “ALOHA” scheme is used, as fully described in F. C. Schoute, “Dynamic framed length ALOHA,” IEEE Transactions on Communications , vol. 31(4). April 1983, the disclosure of which is incorporated herein in its entirety. In an ALOHA scheme, the reader communicates the frame length, and the tags pick a particular slot in the frame in which to transmit. The reader repeats this process until all tags have transmitted at least once successfully in a slot without collisions. In semi-passive and active tag systems, the reader can acknowledge tags that have succeeded at the end of each frame. Hence, those tags can stay silent in subsequent frames, reducing the probability of collisions, thereby shortening the overall identification time. In passive tag systems, all tags will continue to transmit in every frame, which lengthens the total the it takes to identify all tags.
Deterministic identification algorithms typically use a slotted-ALOHA model, where the reader identifies the set of tags that will transmit in a given slot and tries to reduce the contending tag set in the next slot based on the result in the previous slot. These algorithms fall into the class of “tree-based” identification algorithms, with the tags classified on a binary tree based on their IDs, and the reader moving down the tree at each step to identify all nodes. Deterministic algorithms are typically faster than probabilistic schemes in terms of actual tag-response slots used. However, such algorithms suffer from large reader overhead, since the reader has to specify address ranges to isolate contending tag subsets using a probe at the beginning of each slot. The common requirement for both classes of identification algorithms is an estimate of t, the actual number of tags in the system. This estimate is used to set the optimal frame size in framed ALOHA and to guide the tree-based identification process for computing the expected number of slots needed for identification. Hence, it is important to have a quick estimate that is as accurate as possible. The estimation and identification steps could hypothetically be combined or be performed concurrently, to save time, e.g., in probabilistic-identification algorithms. However, the drawback is that the initial steps then rely on inaccurate estimates of the number of tags. Hence, the estimation process should be able to use non-identifiable information, such as a string of bits used by all tags, to compute the size of the tag set t.
Estimation of the cardinality of the tag set is also important in other problems pertaining to RFID tags. Due to privacy constraints, it might not be acceptable for readers to query the tags for their identification in certain instances. In such instances, tags could send out non-identifiable information, which could still be used to compute estimates of cardinality. Another set of problems arises when the tag set is changing so fast that identification of all tags is impossible (e.g., an airplane flying over a field of sensors while trying to obtain an estimate of the number of active sensors remaining in the field). An efficient cardinality estimation scheme should be able to work in such environments as well. It should be noted that, in these instances, using an active tag does not confer any special advantages to the estimation problem from an energy-management perspective, as opposed to using a passive tag.
SUMMARY OF THE INVENTION
Problems in the prior art are addressed in accordance with the principles of the present invention in several aspects. First, the present invention provides, in certain embodiments, an efficient and fast estimation scheme that works extremely well in a wide variety of circumstances. Second, the present invention provides, in certain embodiments, a method that enables the computation of the cardinality of a tag set in a relatively small amount of time, as compared to the time taken for identification. The present invention, in certain embodiments, also involves relatively simple algorithmic modifications to readers and associated equipment that can be used with existing RFID tags and can be implemented using available technology with relatively little incremental cost.
In particular, the present invention, in certain embodiments, proposes two estimation algorithms for a static tag set, and their properties are demonstrated herein through analysis and simulations. It is shown herein that the two estimation algorithms are complementary to one other.
The present invention, in certain embodiments, also provides a single unified estimation algorithm that permits the estimation of the cardinality of a static tag set with a desired level of accuracy, and the performance of the unified algorithm is shown herein via analysis and simulations.
The present invention, in certain embodiments, further provides, using a probabilistic framed-ALOHA model, even better estimation algorithms that can achieve the desired performance in a substantially shorter time than any known algorithm. It is also shown herein that the estimation range of this algorithm spans many orders of magnitude (e.g., from tens of tags to tens of thousands of tags).
In one embodiment, the present invention provides a method for estimating the cardinality of a set of one or more tags in a system that includes the set of one or more tags and one or more readers. The one or more readers issue a command requesting that the tags issue a reply to identify themselves. The command includes timing information defining a total number of timeslots for the reply. In response to the command, one or more of the tags (i) selects a timeslot in which to reply to the command and (ii) issues the reply in the selected timeslot. The method includes: (a) issuing the command; (b) receiving, in one or more timeslots, replies from the one or more tags; and (c) deriving an estimate of the cardinality of the set of one or more tags in the system based on at least one of: (i) the number of zero slots, wherein a zero slot is a timeslot identified as having no tags transmitting therein, (ii) the number of singleton slots, wherein a singleton slot is a timeslot identified as having only one tag transmitting therein, and (iii) the number of collision slots, wherein a collision slot is a timeslot identified as having more than one tag transmitting therein.
In another embodiment, the present invention provides an apparatus for estimating the cardinality of a set of one or more tags in a system that includes the set of one or more tags and one or more readers. The one or more readers issue a command requesting that the tags issue a reply to identify themselves. The command includes timing information defining a total number of timeslots for the reply. In response to the command, one or more of the tags (i) selects a timeslot in which to reply to the command and (ii) issues the reply in the selected timeslot. The apparatus (a) issues the command. (b) receives, in one or more timeslots, replies from the one or more tags, and (d) derives an estimate of the cardinality of the set of one or more tags in the system based on at least one of: (i) the number of zero slots, wherein a zero slot is a timeslot identified as having no tags transmitting therein, (ii) the number of singleton slots, wherein a singleton slot is a timeslot identified as having only one tag transmitting therein, and (iii) the number of collision slots, wherein a collision slot is a timeslot identified as having more than one tag transmitting therein.
In a further embodiment, the present invention provides a machine-readable medium, having encoded thereon program code. When the program code is executed by a machine, the machine implements a method for estimating the cardinality of a set of one or more tags in a system that comprises the set of one or more tags and one or more readers. The method includes: (a) issuing the command; (b) receiving, in one or more timeslots, replies from the one or more tags; and (c) deriving an estimate of the cardinality of the set of one or more tags in the system based on at least one of: (i) the number of zero slots, wherein a zero slot is a timeslot identified as having no tags transmitting therein, (ii) the number of singleton slots, wherein a singleton slot is a timeslot identified as having only one tag transmitting therein, and (iii) the number of collision slots, wherein a collision slot is a timeslot identified as having more than one tag transmitting therein.
BRIEF DESCRIPTION OF THE DRAWINGS
Other aspects, features, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings in which like reference numerals identify similar or identical elements.
FIG. 1 illustrates a plot of normalized expected numbers of slots as functions of the load factor for each of three estimators, in an exemplary embodiment of the present invention;
FIG. 2 illustrates a comparison of the operating ranges for two estimators, in an exemplary embodiment of the present invention;
FIG. 3 illustrates the experimental performance of two estimators, in an exemplary embodiment of the present invention;
FIG. 4 illustrates the experimental distribution of the number of collision slots superimposed on the normal distribution with the mean and variance, in an exemplary embodiment of the present invention;
FIG. 5 illustrates a plot of the normalized estimator variance as a function of load factor, in an exemplary embodiment of the present invention;
FIG. 6 illustrates a plot of the estimated variance of one estimator, in an exemplary embodiment of the present invention;
FIG. 7 illustrates pseudo-code for a unified simple-estimation algorithm that can be derived using two estimators, in an exemplary embodiment of the present invention;
FIG. 8 illustrates a plot of various estimated values in different experimental runs over a single frame against the tag set card finality, in an exemplary embodiment of the present invention;
FIG. 9 illustrates a plot of a probabilistic-estimator variance, in an exemplary embodiment of the present invention;
FIG. 10 illustrates a plot of another probabilistic-estimator variance, in an exemplary embodiment of the present invention;
FIG. 11 illustrates pseudo-code for a unified probabilistic-estimation algorithm that can be derived using two probabilistic estimators, in an exemplary embodiment of the present invention;
FIG. 12 illustrates an RFID system, in an exemplary embodiment of the present invention.
DETAILED DESCRIPTION
System Model
In the exemplary system model used herein, an RFID system consistent with the present invention includes a set of readers and a large number of tags. Such a system adopts a “listen-before-talk” model for the RFID tags, wherein the tags listen to the reader's request before they “talk” back. It is assumed in such a scenario that there exists a separate estimation phase for computing the cardinality of the tag set, which precedes any identification process, and that the identification phase uses the framed-slotted ALOHA model for tags to transmit back to the reader (although the estimation phase could be combined with the identification phase in alternative embodiments). In this system model, given a frame of size f slots, tags randomly pick a slot based on a uniform probability distribution and transmit in that slot. Tags cannot sense the channel and, hence, merely transmit in the chosen slot. Slot synchronization is provided by the reader's request or command, which typically includes a probe to energize the tags.
When probed by the reader in the estimation phase, it is assumed in this system model that tags respond with a bit string that contains some error detection (such as CRC) embedded in the string. The length of this common bit string is defined as the minimum-length string such that the reader can detect collisions when multiple tags transmit the same string in a given slot. This string need not be unique across tags and therefore is typically much smaller than the length of the unique tag identifier. The reader can thus detect collisions in the estimation phase and identify a successful transmission in any slot by only one tag. If a time slot is not chosen by any of the tags, then the reader will recognize that this time slot is idle. The entire system, in this system model, uses a single wireless channel/band for operation.
The load factor ρ of the system in this system model is defined as the ratio of the number t of tags to the number f of time slots in a frame, i.e., ρ=t/f. When a tag chooses to transmit, it has two degrees of freedom: (i) choosing a slot in a frame of size f and (ii) the probability p of transmission in any given frame. Current tag systems already allow variable frame sizes, albeit from a limited set of choices, for both passive and active tags. Accordingly, the reader's transmission request can contain one or both options: (i) a desired frame size f to be used by all tags, and (ii) the probability of transmission to be used by tags for transmitting in a given frame. Given both parameters, the tag first decides whether to participate in the frame with probability p and then picks a slot at random in a frame of size f. Each of these parameters can be varied across frames, resulting in four possible combinations: (i) fixed f with fixed p, (ii) fixed f with variable p, (iii) variable f with fixed p, and (iv) variable f with variable p.
In certain embodiments of the invention, the identification problem, also referred to as collision resolution or conflict resolution, will not be considered (although it should be recognized that solving the identification problem could hypothetically be combined with or performed concurrently with solving the tag cardinality estimation problem, e.g., for probabilistic-identification algorithms). The focus of the present invention, in certain embodiments as described herein, is simply to provide a reliable estimate of the cardinality of the tag set in as little time as possible.
Since the estimation scheme is probabilistic in nature, the accuracy requirement for the estimation process is specified using two parameters: the error bound β>0 and the failure probability 0<α<1.
The problem to be solved is the following: Given a set of t tags in the system, the reader has to estimate the number of tags in the system with a confidence interval of width β, i.e., the goal is to obtain an estimate {circumflex over (t)} such that
t ^ t ∈ ( 1 - β 2 , 1 + β 2 ) ,
with probability p greater than a. In other words, the maximum error should be at most
± β t 2 ,
with probability p greater than a. A sample problem would be to estimate the number of tags within ±1% of the actual number of tags with probability p greater than 99.99%.
The performance of the estimator is measured in terms of the number of slots employed to perform the estimation to the desired accuracy level. Typically, in order to achieve the specified accuracy level, multiple measurements are made. The performance is measured in terms of the total number of slots, summed over all of the measurements. The goal is to achieve the desired performance in as little time as possible. In other words, if it takes l e slots to compute {circumflex over (t)}, the estimate of t tags, with a certain accuracy, and l i slots to uniquely identify {circumflex over (t)} tags, then s e l e <<l i s i should be true, where s e and s i are the sizes of the bit strings transmitted during the estimation and identification phases, respectively.
The variable Z a will be used herein to denote the percentile for the unit normal distribution. If a=99.9%, then Z a =3.2.
A current implementation of random-slot selection in a frame, which implementation can be easily extended to accommodate the probability of transmission in a given frame, will now be described. In the Phillips I-Code system, described fully at Philips Semiconductors, “I-CODE Smart Label RFID Tags,” http://www.semiconductors.com/acrobat_download/other/identification/SL092030.pdf, the disclosure of which is incorporated herein by reference in its entirety, a frame size f (typically a power of 2) is sent by a reader along with a seed value which is a 16-bit number. Each tag uses this seed information along with its identifier to hash into an integer in the range [1, f], which specifies the slot in which the frame will contend. The reader sends a different seed in each frame to ensure tags do not necessarily select the same slot in each frame. It is noted that tag/reader implementations by other RFID vendors follow similar principles for slot selection. This scheme can be extended to support variable contention probability p, as will be discussed in further detail below. The reader now sends three parameters in each probe: (i) the seed, (ii) the frame size f and (iii) the integer
⌈ f p ⌉ ,
where the notation ┌ ┐ indicates the function “smallest integer not less than.” The tag hashes the combined seed/identifier value into the range
[ 1 , ⌈ f p ⌉ ] .
If the hashed value is greater than f, then the tag does not transmit in this frame, else, it transmits in the computed slot, thereby resulting in a frame transmission probability of
f f / p = p .
This model is implemented in the simulations described herein, except that, in the simulations described herein, the drand( ) function is used for the hashing scheme.
Based on the I-Code system, the estimator slot is set to be 10 bits long (which is actually an overestimate, since it is possible to detect collisions using even smaller bit lengths), to achieve a rate of 4000 estimation slots per second. The unique tag ID field is 56 bits long, including the CRC, and the maximum tag-identification rate in I-Code is 200 tags per second, using a 56-kbps bit-rate. Thus, the estimation slot is much smaller than the identification slot.
Simple-Estimation Algorithms
Two different estimators for t, the cardinality of the tag set, are developed herein, assuming that all tags transmit in all frames during the estimation process. The two estimators complement one another well, and combining them provides an estimation algorithm that performs well for a wide range of tag-set cardinalities.
In the exemplary system model used herein, the reader with frame size f probes the tags, and the tags pick a slot j in the frame uniformly at random and transmit in that slot. The indicator random variable X j is used for the event in which there is no transmission in slot j. In other words, X j =1 if no tag transmits in slot j, and X j =0 otherwise. Similarly, Y j =1 if and only if there is exactly one tag that transmits in slot j, and V j =1 if and only if there are multiple tags that transmit in slot j. It is noted that X j +Y j +V j =1 for all slots j. If slot j has no transmissions in it, i.e., X j =1, then this slot j will be referred to as an empty slot or a zero slot. If exactly one tag transmits in slot j, i.e., Y j =1, then slot j will be referred to as a singleton slot. If multiple tags transmit in slot j, creating a collision, i.e., V j =1, then slot j will be referred to as a collision slot. The total number of empty slots will be denoted by
N 0 = ∑ j = 1 f X j ,
the total number of singleton slots will be denoted by
N 1 = ∑ j = 1 f Y j ,
and the total number of collision slots will be denoted by N c =f−N 0 −N 1 . It is noted that N 0 , N 1 , and N c are random variables. The values that are observed by the reader in a particular instance are represented by n 0 , n 1 , and n c . The reader derives an estimate of t based on (n 0 , n 1 , n c ). The following Lemma 1 assists in arriving at the estimate of t.
Lemma 1. Let (N 0 , N 1 , N c ) represent the number of time slots with no transmissions, one transmission, and collision, respectively, in a system with t tags and frame size f. Let ρ=t/f. Then:
E[N 0 ]≈fe −ρ ,
E[N 1 ]≈fρe ρ , and
E[N c ]≈f (1−(1+ρ) e ρ ).
To obtain the estimators, the reader first measures (n 0 , n 1 , n c ). From Lemma 1, it is known that the expected number of empty slots is fe −ρ , or the fraction of empty slots is e −ρ . From the current measurement, the reader observes that the fraction of empty slots is n 0 /f. Equating the expected value and the observed value, the reader now determines ρ 0 that solves e −ρ 0 =n 0 /f and sets t 0 =fρ 0 . Similarly, the reader can obtain estimates for t from the singleton slots, as well as from the collision slots. The three exemplary estimators and estimates for t are shown in the following Table 1.
TABLE 1
Estimator
Problem to be Solved
ZE: Zero
e −(t 0 /f) = n 0 /f
Estimator t 0
SE: Singleton
(t 1 /f) e −(t 1 /f) = n 1 /f
Estimator t 1
CE: Collision
1 − (1 + (t c /f)) e −(t c /f) = n c /f
Estimator t c
The estimator based on t 0 can be solved for relatively easily in closed form, but the other two estimators involve solving a non-linear equation in one variable. A simple bisection search or Newton's method can be used to solve the equation, since the estimation functions shown in Table 1 above are “well-behaved.” and therefore, both of these methods converge relatively quickly. Also, when the estimate is an integer, the search can terminate once the interval of uncertainty is known to be less than one, and this fact can also be used in solving the equation. Notwithstanding other possible search methods, the bisection search method will be used herein.
The three exemplary estimators have very different characteristics. FIG. 1 illustrates a plot of the normalized expected values, E[N 0 ]/f, E[N 1 ]/f, and E[N c ]/f, as functions of the load factor ρ. It is noted that the curves for empty slots and collision slots are monotonic in ρ, but the curve for singleton slots is non-monotonic. Intuitively, when the load factor is very low, there are many empty slots but very few singleton or collision slots. As the load factor increases, the number of empty slots decreases with a corresponding increase in the number of singleton and collision slots. The expected number of singleton slots attains a maximum when the load factor ρ=1, a fact widely used in identification algorithms to optimize the number of successful identifications in a single frame. From this point on, as the load factor increases, there are many more collision slots, and the number of singleton slots decreases. Thus, when the reader solves for ρ 1 in e −ρ 1 =n 1 /f, the solution is not unique for ρ=1. This suggests that it is not desirable to use the singleton slots alone for estimating the number of tags. Therefore, the following discussion will focus on the zero estimator (ZE), with an estimate denoted by {circumflex over (t)}=t 0 , and the collision estimator (CE), with an estimate denoted by {circumflex over (t)}=t c .
The operating range for the estimators will now be discussed. When the number of tags t<<f, then all slots in the frame have a high probability of encountering collisions, resulting in n 0 =n 1 =0 and n c =f. In such cases, both the zero estimator and the collision estimator will not have finite estimates, i.e., t 0 =t c =1. Since the number of tags is assumed to be fixed, as the frame size increases (and the load factor decreases), the probability that estimators are finite will increase. In other words, given a frame size f, there is an upper bound on the number of tags that can be estimated reliably using a given estimator.
Definition 1. Given a frame size f and a probability θ<1, the operating range for an estimator is defined as the maximum number t of tags for which the estimator has a finite solution with probability greater than θ.
The definition of the operating range simply ensures that a finite estimate can be obtained. (It should be noted that the operating range does not speak to the accuracy of the estimate when the estimate is finite.) For a fixed f, the objective for the zero estimator (ZE) is to determine the maximum number of tags that will result in no empty slots with a probability of less than 1−θ, and the objective for the collision estimator (CE) is to determine the maximum number of tags that will result in collisions in all slots with a probability of less than 1−θ. The following classical result due to von Mises (as fully explained in Feller, An Introduction to Probability Theory and Its Applications , Vol. 1, John Wiley, 1968, the contents of which are incorporated herein by reference in its entirety) on the distribution of N 0 and N 1 will be used.
Lemma 2. Let t tags each pick a slot randomly from among f slots and transmit in that slot. Let t, f→∞ while maintaining t/f=ρ. Then, the number N 0 of empty slots approaches a Poisson random variable with parameter λ 0 =fe −ρ and the number N 1 of singleton slots is distributed approximately as a Poisson random variable with parameters λ 1 =fρe −ρ , where ρ=t/f is the load factor.
Using the above result, the probability that the reader fails to obtain a finite t 0 is the probability that N 0 =0. Since N 0 is distributed as a Poisson variable with parameter λ 0 ,
Pr[N 0 =0 ]=e −λ0 .
Hence, requiring the failure probability to be less than (1−θ) is equivalent to setting λ 0 ≦−log(1−θ). If θ is set to 0.99, this corresponds to setting λ 0 ≦5. (When λ 0 =5, the failure probability is about 0.007.)
In the case of the CE estimator, the estimation process fails only if N c =f, i.e., there are no empty or singleton slots. This probability is given by
Pr[N 0 =0 ,N 1 =0 ]≈e −λ0−λ1 .
Again using θ=0.99, it can be seen that, as long as the load factor ensures that λ 0 +λ 1 <5, then the collision-based estimator fails with a probability of less than 0.007.
FIG. 2 illustrates a comparison of the operating ranges for the ZE and CE estimators for θ=0.99, i.e., a failure probability of less than 1%. The x-axis represents the number of slots, and the y-axis represents the maximum number of tags t 0 and t c that can be estimated using the ZE and CE estimators, respectively. It is noted that the range for the CE estimator is greater than the range of the ZE estimator. This difference increases with frame size. For example, the operating range for the CE estimator is about 180 higher than that of the ZE estimator for f=100 slots and is about 11600 higher when f=5000 slots. Therefore, the collision-based CE estimator can operate at higher load factors than the empty slots-based ZE estimator.
FIG. 3 illustrates the experimental performance of the CE and ZE estimators when f=100, when the number of tags is increased from 0 to 1000. The x-axis represents the actual number of tags, and the y-axis represents the estimated numbers of tags, t 0 and t c . The ideal curve is the 45-degree line shown in the plot. Each point in the plot represents the average of 100 experiments. It is noted that the performance of t 0 starts deteriorating when the number t of tags is about 350, and that the performance of t c starts deteriorating when t is about 550.
From the foregoing results, it can be observed that, with increasing frame size, the operating range expands for both estimators, with a larger range for the Collision Estimator than for the Zero Estimator. This also implies that the Collision Estimator works well for a greater range of load factors than the Zero Estimator.
Determining the accuracy of the estimators will now be discussed. First, however, the variance of the CE and ZE estimators is derived. The computation of the variance not only permits comparison of the accuracy of the two estimators but also assists in deciding how to use the estimators to obtain the desired accuracy level for the estimates. In the previous discussion herein, the fact that N 0 and N 1 can be approximated as Poisson random variables was used. The reason for preferring the Poisson distribution above is that it is a discrete distribution that gives a probability mass-function value at zero for N 0 and N 1 . It turns out that N 0 and N 1 can also be asymptotically approximated as normal distributions, a fact that is used for analyzing the variance of the estimators. A normal distribution with mean a and variance b is denoted by N[a, b].
Theorem 1. Let each of t tags pick randomly from among f slots and transmit in the randomly-selected slot. N 0 represents the number of empty slots, and N c represents the number of collision slots. If f, t→∞ while maintaining f/t=ρ, then
N 0 −N[μ 0 ,σ 0 2 ],
where
μ 0 =fe −ρ , σ 0 2 =fe −ρ (1−(1+ρ) e −ρ ),
and
N c −N[μ c σ c 2 ],
where
μ c =f (1 −e −ρ (1+ρ)),
and
σ c 2 =fe −ρ ((1+ρ)−(1+2ρ+ρ 2 +ρ 3 ) e −ρ ).
FIG. 4 illustrates the experimental distribution of the number of collision slots, superimposed on the normal distribution with the mean and variance, computed as in Theorem 1.
Ultimately, instances of N 0 and N c are measured, which are then used to estimate t. It is noted that μ 0 and μ c are viewed as (non-linear) functions of the number t of tags, i.e., as μ 0 (t) and μ c (t). From Lemma 1 and FIG. 1 , it is known that both μ 0 (t) and μ c (t) are monotonic continuous functions of t, i.e., μ 0 (t) is increasing in t, and μ c (t) is decreasing in t. Since they are monotonic and continuous, both of these functions have unique inverses, denoted by g 0 ( ) and g c ( ), respectively. In other words, g 0 (μ 0 (t))=t, and g c (μ c (t))=t.
Theorem 2. Let t, f→∞ while maintaining t/f=ρ. Then,
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In order to compare the variances of the two estimators, the notion of a normalized variance, which is the ratio of the estimator variance to the number of tags, is first defined. The normalized variance of the ZE estimator is δ 0 /t, and the normalized variance of the CE estimator is δ c /t. From the expressions for the estimator variance shown above, the normalized variance is just a function of the load factor. ρ. FIG. 5 illustrates a plot of the normalized estimator variance as a function of the load factor. There are three observations that can be made from FIG. 5 . First, for ρ<1, the variance of t 0 decreases, while the variance of t c increases. In other words, if the number t of tags is fixed, and the number of slots is increased, the empty slots-based ZE estimator becomes more accurate, while the collision slots-based CE estimator becomes less accurate. Second, as the load factor increases, the variance of the collision-based CE estimator becomes significantly less than the variance of the empty slots-based ZE estimator. Third, the ZE estimator can achieve an arbitrarily-low normalized variance, while the normalized variance of the CE estimator is always at least 0.425. These observations suggest that, for estimating a given tag set with cardinality t, the ZE estimator can be used with a very large frame size to obtain any desired accuracy in a single frame, assuming such a frame size is allowed. On the other hand, with the CE estimator, other methods of reducing the variance are desirably investigated. It should also be recognized that the two estimators are complementary to one other. At load factors greater than a given threshold, the CE estimator performs better, while the ZE estimator performs better at lower load factors.
The reduction of the variance of the simple estimators will now be discussed. Given the expressions for the variance of the ZE and CE estimators, as provided in Equations (1) and (2) above, a straightforward way of reducing the variance of an estimator is to repeat the experiment multiple times and take the average of the estimates. If the final estimate is the average of m independent experiments, each with an estimator variance of σ 2 , then the variance of the average is σ 2 /m. The variance can also be manipulated by changing the frame size or performing a weighted average of the estimates. Before choosing a method for reducing the variance, the characteristics of the two estimators should first be understood.
The variance of the ZE estimator can be reduced by reducing p or, equivalently, by increasing the frame size, f. It can be shown that having a frame of size mf and performing the reading once provides a lower variance for t 0 than having a frame of size f and averaging the results of m experiments. If the variance is desired to be less than σ 2 for a given estimate {circumflex over (t)}, then ρ is first solved for in the expression
t ^ ( e ρ - ( 1 + ρ ) ) ρ ≤ σ 2 ,
and f can then be set so that f≧{circumflex over (t)}ρ.
From the estimated variance plot of FIG. 6 , it can be seen that t c attains minimum variance when ρ=1.15. This is obtained by evaluating the minima of Equation 2 with respect to ρ. It is noted that ρ=1.15 is equivalent to setting f=(1/1.15) t=0.87t. The minimum variance when ρ=1.15 is 0.425 t. If f is fixed at f=0.87 t, the experiment is repeated m times, m estimates are averaged, and then the variance of the final estimate is reduced by a factor of about m, i.e., the variance will be 0.87 t m. This suggests that if the final variance is desired to be less than σ 2 , then the measurement should be repeated at least ┌0.87t/σ 2 ┐ times.
Two other practical issues will now be addressed: maximum frame size and frame overhead. Regarding maximum frame size, the frame size that arises from the computation for a desired variance may be quite large, especially in the case of the ZE estimator. In practice, systems typically have some maximum frame-size restriction. Therefore, if the frame-size computation provided above leads to a size larger than the maximum permitted, then the maximum-permitted frame size can be used instead. This implies that multiple experiments are desirably performed in order to reduce the variance, even for the ZE estimator. The variable f max is used to denote the maximum frame size. Regarding frame overhead, there is typically some overhead associated with each frame, primarily the time and/or energy that is used to energize the tags. It is assumed that the frame overhead is specified in terms of the number of slots used to initialize a frame, and this quantity is denoted by the variable τ. Therefore, a frame of size f actually uses up f+τ slots.
Based on the observation that the two estimators are complementary to one other, a unified simple-estimation algorithm can be derived, which uses both estimators, depending on the frame size and the estimated number of tags. For a given frame size and tag-set estimates from the two estimators, the value with the lower variance is chosen and is used to refine subsequent estimates.
Pseudo-code for one such exemplary unified algorithm is shown in FIG. 7 . This algorithm receives as input (i) an upper bound t on the number t of tags, (ii) a confidence interval width β, and (iii) an error probability α. The algorithm computes a desired variance and an initial frame size f and then energizes the tags. Next, the algorithm computes the numbers of zero slots and collision slots and the respective variances of each. The slot type (zero or collision) having the smaller variance is chosen to be used in calculating the cardinality estimate. The frame size f ZE needed for the zero estimator to obtain the desired variance is then computed. Next, the number of repetitions needed to obtain the desired variance is computed using equations (1) and (2), which the algorithm then uses to generate the total number of slots for the ZE estimator and the CE estimator, respectively, including frame overhead. If the total number of slots for the ZE estimator is less than the total number of slots for the CE estimator, then the ZE estimator is used, in conjunction with the appropriate number of repetitions calculated to generate multiple estimates of the cardinality of the tag set. If the total number of slots for the ZE estimator is not less than the total number of slots for the CE estimator, then the CE estimator is used, in conjunction with the appropriate number of repetitions calculated to generate multiple estimates of the cardinality of the tag set. The final value for the estimated cardinality of the tag set is the average of the multiple estimates over all of the repetitions.
The simple estimators described above are capable of estimating the value of t within a 20% confidence interval (β=20) in a single frame, assuming that the frame size is initially appropriately chosen to accommodate the operating range of measurements. This is demonstrated by the experimental results in FIG. 8 , in which the various estimated values in different experimental runs over a single frame are plotted against the tag-set cardinality, t. The frame size is selected to be 1000 slots. For comparison, the 20% confidence interval is also plotted, represented by the upper and lower lines with slopes 11 and 0.9, respectively. Also shown are the results of the tag-set size estimator described in Vogt, “Efficient Object Identification with Passive RFID Tags,” Lecture Notes in Computer Science , Springer-Verlag, vol. 2414, 2002, incorporated by reference herein in its entirety, wherein a lower bound is computed as {circumflex over (t)}≧n 1 +2n c . The estimators presented in the Vogt reference are believed to be relatively superior and to be able to provide a high confidence estimate in as few as 1000 slots.
With the proposed estimation schemes in the I-Code system discussed above, the size of a 4500-tag set can be estimated with 20% accuracy in 0.25 seconds. The amount of time to achieve the same accuracy with the identification scheme described in the I-Code reference “I-CODE Smart Label RFID Tags,” is 18 seconds. Even if the system only had 500 tags, the scheme described herein can still estimate the size within ±100 in 0.25 seconds, while the identification scheme described in the I-Code reference takes 2 seconds.
Mention was made above that, with m multiple experimental estimates, averaging the estimates will reduce the variance by m. The variance can be even further reduced by weighted averaging of the estimates. This can be done, e.g., using the following statistical result.
Theorem 3. Let e 1 , e 2 , . . . , e k be k estimates for t with variances ν 1 , ν 2 , . . . , ν k . For any set {α i } with 0≦α t ≦1 and Σ i α i =1, the expression
∑ i = 1 k α i e i
is an estimator for t having a variance of
∑ i = 1 k α i 2 v i .
The optimal choice of α i that minimizes the variance of the linear combination is
α i = 1 v i ∑ i = 1 k 1 v i ,
and the minimum variance is
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Weighted statistical averaging is used to compute the final variance of the sampled estimates in the simulations described herein. Using the unified simple-estimation algorithm of FIG. 7 , the number of slots needed to estimate various tag sets with set sizes ranging from 5 to 50,000 is measured. In order to accommodate this large operating range, the initial frame size f as described in FIG. 7 , is set to 6984 slots. It is noted that subsequent frames can be of different sizes. Simulations were used to find, for various levels of accuracy, the number of slots needed for estimation, and the results are shown in the following Table 2.
TABLE 2 Slots needed for Number confidence interval (in %) of of tags 0.2 0.1 0.05 0.02 5 6984 6984 6984 6984 50 7028 7256 7826 14837 500 7498 7498 8666 15674 5000 12736 12736 12736 18558 50000 65378 65378 182306 883874
These results show that for tag sizes well within the operating range, the algorithm easily estimates the number of tags to within a couple of frames, with an accuracy of greater than 0.05%. However, there is very little adjustability of the algorithm for various levels of accuracy. In addition, as the desired accuracy increases, or as the number of tags reaches the upper end of the operating range, the algorithm takes a large number of slots to obtain the desired estimate, mainly due to the large frame sizes involved. However, the algorithm can advantageously obtain an estimate of 50,000 tags within a confidence interval of ±500 tags in 4.5 seconds and within ±50 tags in 16 seconds, while the time spent for identification is 100 seconds or more.
The following Table 3 shows different numbers of slots needed to achieve various operating ranges in estimating the cardinality of a set of 500 tags with a confidence interval of ±5 tags.
TABLE 3 Slots needed 500 1000 5000 10,000 50,000 Operating range 714 870 1554 2302 7498
The foregoing data shows that there is a tradeoff between operating range and estimation time (as a function of frame size) when the number of tags is well within the operating range.
Scalable Estimation Algorithm
Estimation schemes that allow all tags to contend in every frame have a specific operating range that is dependent on the frame size chosen, e.g., as in the unified simple-estimation algorithm of FIG. 7 . Hence, in order to estimate any tag-set size t, an upper bound on the tag-set size is assumed, and the frame size is fixed, such that the operating range stretches up to the upper bound. In addition, the optimal frame sizes for computing a low-variance estimate are lower-bounded by the tag-set size t for both the ZE and the CE estimators. This requirement can be impractical in actual systems for large values of t.
In some cases, the number of tags is of orders of magnitude larger than the maximum frame size f max , and f max can be very small. Extending the framed ALOHA to include probabilistic contention increases the range and improves the accuracy of estimates when the load factor is large. To this end, a new protocol termed Probabilistic-Framed ALOHA (PFA) protocol will now be described.
Definition 2. The Probabilistic-Framed ALOHA (PFA) protocol is defined as the framed-ALOHA protocol model with a frame size f and an additional contention probability p. A node in the PFA protocol decides to contend in a frame with probability p, and if it decides to contend, it picks one of the f slots in which to transmit.
It is noted that the PFA protocol is just a simple extension of probabilistic ALOHA to the framed model. When p=1 the PFA protocol becomes the Framed-ALOHA protocol. The analysis of the behavior of a probabilistic estimator in the PFA model will now be discussed. The following Theorem 4 is analogous to Theorem 1 and provides the mean and the variance for the numbers of empty slots and collision slots for the PFA scheme.
Theorem 4. Let t tags each pick randomly from among f slots and transmit in the randomly-selected slot if they choose to contend with probability p. Then,
N 0 −N[μ 0 ,σ 0 2 ],
and
N c −N[μ c ,σ c 2 ],
where
μ 0 =fe −pρ , σ 0 2 =fe −pρ (1−(1 +p 2 ρ) e −pρ ),
μ c =f (1 −e −pρ (1 +p ρ)),
and
σ c 2 =fe −pρ ((1 +p ρ)−(1+2 pρ+p 2 ρ 2 +p 4 ρ 3 ) e −pρ ).
The estimators t 0 and t c for the probabilistic case are computed as shown in the following Table 4.
TABLE 4 Estimator Problem to be Solved PZE: Empty Slot e −(pt 0 /f) = n 0 /f Estimator t 0 PCE: Collision 1 − (1 + (pt c /f)) e −(pt c /f) = n c /f Estimator t c
The abbreviations PZE and PCE are used to denote the estimators in the context of PFA.
The variance of the estimators will now be provided, and the derivation is similar to the framed-ALOHA derivation in Theorem 2. The estimator functions for the PFA model are g 0 (x) and g c (x), with g 0 (μ 0 )=g c (μ c )=t, where μ 0 and μ c are defined as in Theorem 4.
Theorem 5. Let N 0 and N c be the number of empty slots and number of collision slots, respectively. Then,
[g 0 (N 0 )−g 0 (μ 0 )]−N[0,δ 0 ],
and
[g c (N c )−g c (μ c )]−N[0,δ c ],
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The main use of the probabilistic scheme is for handling cases in which both (i) the number of tags is large, and (ii) it is not feasible to increase the frame size to accommodate the tags. Therefore, it is temporarily assumed that the values of t and f are fixed, and that the load factor ρ=t/f is relatively large.
The problem of choosing the optimal contention probability given the load factor ρ will now be addressed for both the PZE and the PCE estimators. In the case of the PZE estimator, the partial derivative of δ 0 with respect to p is calculated and set to zero to obtain the minimum variance. The partial derivative is given by
∂ δ 0 ∂ p = t ( ρ pe p ρ - 2 e p ρ + 2 ) ) p 4 ρ 2 = 0.
In order to obtain the minimum variance, p is solved for in the following equation:
ρ pe pρ −2 e pρ +2=0.
Since pρ occurs together in the expression, it is easy to show numerically that the minimum is attained when p is chosen such that pρ=1.59. Therefore, the optimal p=1.59/ρ. If ρ<1.59, then the optimal value for p=1. FIG. 9 is a plot of PZE estimator variance in an experimental simulation. This plot illustrates how the variance changes with p for two different values of ρ. In the case of the PCE estimator, the minima of the function δ c (p,ρ) is sought with respect to p to obtain the value of p that provides minimum variance. The optimal p will satisfy
e pρ ( p 2 ρ 2 −2 pρ− 4)+2( p 2 ρ 2 +3 pρ+ 2)=0.
Once again, it is noted that p and ρ occur together, and therefore, it is relatively easy to solve this numerically to show that the minimum is attained when pρ=2.59. Therefore, p=2.59/ρ, and p=1 if ρ<2.59.
It can also be seen that the collision-based PCE estimator is robust over a larger range than the empty slots-based PZE estimator. FIG. 10 is a plot of PCE-estimator variance in an experimental simulation. This plot illustrates how the variance changes with respect top for two different values of ρ. The probabilistic-contention mechanism permits a dramatic reduction in the frame size used, even when t is large. If the variance for a single estimate is too large, then averaging multiple estimates reduces variance.
The PZE and PCE estimators are combined using the same approach as described above with respect to the ZE and CE estimators, to obtain a unified probabilistic-estimation algorithm. Pseudo-code for one such exemplary unified probabilistic-algorithm is shown in FIG. 11 . This algorithm receives as input (i) a frame size f (ii) a confidence interval width β, and (iii) an error probability α. Based on variances and cardinality estimates obtained over multiple runs of the CE and/or ZE estimators, the algorithm outputs an estimation {circumflex over (t)} of the cardinality of the set of t tags that satisfies the specified accuracy requirement.
One of the advantages of the PFA protocol is that the total estimation time for given accuracy level is independent of the cardinality t of the tag set. This will now be illustrated using simulation results. As in the simulation results of the simple-estimator algorithms discussed above, the number of slots used to estimate various tag sets is measured with set sizes ranging from 5 to 50,000. Operating range is not an issue in this situation, since the probability of contention will be adapted dynamically depending on the number of tags present. The frame size is set to be a constant, f=30 slots, and the probability of contention in a frame is varied.
For various levels of accuracy, simulations were used to find the number of slots needed for estimation, and the results are shown in the following Table 5.
TABLE 5 Slots needed for Number confidence interval (in %) of of tags 0.2 0.1 0.05 0.02 5 90 390 1440 8970 50 60 210 840 5190 500 180 540 2220 12420 5000 210 600 2220 13590 50000 240 660 2280 13560
The first observation to be made is that, for a given confidence level, the number of slots needed is nearly independent of the tag size. The second observation is that the number of estimation slots needed is of orders of magnitude smaller than those used for the unified simple-estimation algorithms (Table 2). As the accuracy requirement increases by a factor of x, the estimation time increases by a factor of x 2 . This is expected, since the variance is related to the square of the confidence levels. It can be seen that the estimation time for a tag-set size of 50 is much better than the estimation time for a tag-set size of 5. This is because of the frame size of 30, which results in a near-optimal variance estimate for the tag-set size of 50, as compared to the tag-set size of 5. In terms of actual time, assuming a rate of 4000 estimation slots per second, any tag size (not necessarily restricted to 50,000) can be estimated with a confidence interval of 0.05 within 1 second. This is an entirely unique result as compared to prior art estimation methods.
FIG. 12 illustrates an exemplary RFID system 100 , including reader 200 and a plurality of tags 300 in selective communication with reader 200 . A computer, such as server 400 , is configured to perform the estimation methods based on data exchanged with the reader. While system 100 depicts an RFID system that might be used in performing one or more of the estimation methods of the present invention, as described herein, it should be understood that other systems are possible, such as those including other numbers of tags and/or readers. It should also be understood that, while a server, computer, or other processing device may be used to perform one or more of the estimation methods of the present invention, as described herein, such estimation methods may alternatively or additionally be performed by one or more of the readers themselves.
It should be understood that, while the present invention is described in terms of RFID tags and readers, the invention has utility in other applications in which estimation of the cardinality of a set of objects is performed. For example, the methods described herein could possibly have utility in estimating a cardinality of a wired or wirelessly-networked elements, such as electronic product-code (EPC) tags, nodes on a computer network, mobile telephone devices in a given range, customer loyalty cards or identification devices in a store, or even molecules, particles, biological organisms, or cells that exhibit particular responsive behaviors in a given environment. The broad terms “reader” and “tag” should be understood to include not only RFID readers and RFID tags, respectively, but also other devices performing the same or similar functions in RFID applications or in other applications, such as the exemplary applications set forth in this paragraph.
It should be recognized that the invention has applicability to both “smart” or active tags and “dumb” or passive tags, and that the expressions “probing” or “issuing a command” to a tag, as used herein, may include (i) energization of the tag and (ii) transmission of data to the tag, but does not necessarily include both of these functions, e.g., in the case of active tags that are self-powered, no energization of the tag is necessary.
The term “random” in the context of selection or number generation, as used herein, should not be construed as limited to pure random selections or number generations, but should be understood to include pseudo-random, including seed-based selections or number generations, as well as other selection or number generation methods that might simulate randomness but are not actually random, or do not even attempt to simulate randomness.
It is also possible that, in certain embodiments of the present invention, an algorithm could be used wherein certain tags are instructed not to respond to a probe at all, under certain circumstances. For example, in certain embodiments, systems employing PZE and/or PCE estimators could employ tags that are adapted not to transmit any response if the computed random number provided by the reader exceeds a given threshold value.
The present invention may be implemented as circuit-based processes, including possible implementation as a single integrated circuit (such as an ASIC or an FPGA), a multi-chip module, a single card, or a multi-card circuit pack. As would be apparent to one skilled in the art, various functions of circuit elements may also be implemented as processing blocks in a software program. Such software may be employed in, for example, a digital signal processor, micro-controller, or general-purpose computer.
The present invention can be embodied in the form of methods and apparatuses for practicing those methods. The present invention can also be embodied in the form of program code embodied in tangible media, such as magnetic recording media, optical recording media, solid state memory, floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage medium, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. The present invention can also be embodied in the form of program code, for example, whether stored in a storage medium, loaded into and/or executed by a machine, or transmitted over some transmission medium or carrier, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. When implemented on a general-purpose processor, the program code segments combine with the processor to provide a unique device that operates analogously to specific logic circuits.
The present invention can also be embodied in the form of a bitstream or other sequence of signal values electrically or optically transmitted through a medium, stored magnetic-field variations in a magnetic recording medium, etc., generated using a method and/or an apparatus of the present invention.
Unless explicitly stated otherwise, each numerical value and range should be interpreted as being approximate as if the word “about” or “approximately” preceded the value of the value or range.
It will be further understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain the nature of this invention may be made by those skilled in the art without departing from the scope of the invention as expressed in the following claims.
The use of figure numbers and/or figure reference labels in the claims is intended to identify one or more possible embodiments of the claimed subject matter in order to facilitate the interpretation of the claims. Such use is not to be construed as necessarily limiting the scope of those claims to the embodiments shown in the corresponding figures.
It should be understood that the steps of the exemplary methods set forth herein are not necessarily required to be performed in the order described, and the order of the steps of such methods should be understood to be merely exemplary. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments of the present invention.
Although the elements in the following method claims, if any, are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.
Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term “implementation.” | In one embodiment, a method for estimating the cardinality of one or more tags in a system that has the one or more tags and one or more readers. The reader issues a command requesting that the tags identify themselves. The command includes timing information defining a total number of timeslots. In response to the command, each of the one or more tags (i) selects a timeslot in which to reply to the command and (ii) issues a reply in the selected timeslot. The method includes: (a) issuing the command; (b) receiving, in one or more timeslots, replies from the one or more tags; and (c) deriving an estimate of the cardinality of the one or more tags in the system based on at least one of: (i) the number of zero slots, wherein a zero slot is a timeslot that has no tags transmitting therein, (ii) the number of singleton slots, wherein a singleton slot is a timeslot that has only one tag transmitting therein, and (iii) the number of collision slots, wherein a collision slot is a timeslot that has more than one tag transmitting therein. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a U.S. National Phase Application under 35 U.S.C. §371 of International Patent Application No. PCT/IN2012/000483 filed Jul. 9, 2012, which claims the benefit of Indian Patent Application Serial No. 1973/MUM/2011 filed Jul. 8, 2011, both of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention deals with the production of hydrogen using a six step thermochemical copper-chlorine (Cu—Cl) cycle as one variant. Water is split into hydrogen and oxygen through chemical reactions at high temperatures through copper and chlorine compounds to form a closed loop cycle. The present invention also relates to a system, including experimental set up for the production of copper oxide and oxygen production by chlorination of copper oxide as a part of thermochemical Cu—Cl cycle wherein copper chloride is reacted with superheated steam to produce cooper oxide and chlorination of formed copper oxide further produces oxygen. The reactions are carried out in fixed bed reactor at high temperature and atmospheric pressure.
BACKGROUND OF THE INVENTION
Today, the need for alternative energy sources is a central concern because of traditional resource depletion and global climate change due to emission of greenhouse gases. Hydrogen is an apparent alternative to hydrocarbon fuels. It has been proposed as a means to reduce greenhouse gases and other harmful emissions, satisfying the need of efficient, sustainable, non-polluting source of energy. It is an ideal energy carrier that helps to increase our energy diversity and security by reducing our dependence on hydrocarbon-based fuels.
Hydrogen is produced from a very diverse base of primary energy feedstocks and a variety of process technologies including steam reforming, partial oxidation, coal gasification, biomass pyrolysis/gasification, electrolysis, photosynthetic/photobiological, photocatalytic water splitting and thermochemical water splitting.
Hydrogen production from water splitting is environmentally benign and attractive as a clean source of energy. Thermochemical process for hydrogen production utilizing water as a raw material and nuclear energy as primary energy source is an attractive option which involves the separation of water into hydrogen and oxygen through chemical reactions at high temperatures to create a closed loop where water can be fed to the process; and all other reactants are regenerated and recycled.
More than hundred thermochemical cycles have been reported in the literature. A few of the most promising cycles have been studied so far based on some criteria as simplicity of the cycle, efficiency of the process and the ability to separate a pure hydrogen product. Among various feasible thermochemical cycles i.e. sulphur-iodine, cerium-chlorine, iron-chlorine, vanadium-chlorine and copper-chlorine, Cu—Cl cycle has the advantage to produce required hydrogen at a relatively low temperature (550° C.).
Cu—Cl cycle is a hybrid process which uses both heat and electricity to carry out a series of reactions i.e. chemical and electrochemical reactions where the net reaction is the splitting of water into hydrogen and oxygen. The proposed Cu—Cl cycle has two variations, which are known as a four-step process and a five-step process. There are some technical challenges associated with Cu—Cl cycle. Despite these challenges and risks, the Cu—Cl cycle offers a number of key advantages.
GB1461646 discloses a process for production of water by an endothermic cycle through intermediate copper-chlorine and magnesium compounds where intermediary products react and are regenerated.
U.S. Pat. No. 3,919,406 describes a closed loop thermochemical route for production of hydrogen by a succession of four reactions where chlorides of copper and magnesium, hydrochloric acid, and magnesium oxide break down water into its constituent elements with a net result of splitting water into hydrogen and oxygen.
US2008/0256952 discloses a solar powered thermochemical Cu—Cl hydrogen production system and a solar heating system with molten salt comprising sodium nitrate and potassium nitrate, as a heat transfer medium to provide thermal and electrical energy to the thermochemical, system.
US2010/0129287 describes a system for production of hydrogen gas from water decomposition using a thermochemical cycle comprising three, four and five steps. The present invention relates to reactors and vessels and heat coupling methods which are used in a closed loop of a copper-chlorine thermochemical cycle to produces hydrogen and oxygen by using energy from clean sources such as nuclear and solar.
US2010/0025260 discloses a new approach to use low grade heat or waste heat from nuclear or an industrial sources for hydrogen production using combined chemical or vapor compression heat pumps and a thermochemical cycle.
Barbooti et al. (Thermochimica Acta 78 (1984) 275-284) have explained the copper-chlorine thermochemical cycle involving the set of reactions such as hydrogen production, partial regeneration of copper, dechlorination of copper chloride, generation of oxygen and regeneration of hydrogen chloride.
Lewis et al. (Nuclear Production of Hydrogen, Third Information Exchange Meeting, 2003) have developed low temperature cycles designed for low temperature heat around 500 to 550° C.
Rosen et al. (Canadian Hydrogen Association Workshop, 2006) have focused on a copper-chlorine (Cu—Cl) cycle, which has been identified as a highly promising cycle for thermochemical hydrogen production driven by nuclear heat from Super-Critical Water Reactor (SCWR).
Lewis et al. (Int. J. Hydrogen Energy 34(9) (2009) 4115-4124 and 4125-4135) have carried out a detailed study of thermochemical cycles for efficiency calculations.
Orhan et al. (Int. J. Hydrogen Energy 35 (2010) 1560-1574) have studied the coupling of Cu—Cl thermochemical cycle with a desalination plant for nuclear-based hydrogen production.
Rosen et al. (Canadian Hydrogen Association Workshop, 2006) have focused on a copper-chlorine (Cu—Cl) cycle, which has been identified as a highly promising cycle for thermochemical hydrogen production driven by nuclear heat from Super-Critical Water Reactor (SCWR).
Daggupati et al. (Int. J. Hydrogen Energy 35(10) (2010) 4877-4882) have examined copper chloride solid conversion during hydrolysis to copper oxychloride in the thermochemical copper-chlorine (Cu—Cl) cycle of hydrogen production.
Serban et al. (AIChE 2004 Spring National Meeting, 2004) has adopted an approach of seeking water-splitting cycles that have maximum reaction temperatures of less than 550° C. This makes it possible to consider a number of lower temperature nuclear reactors, including supercritical water and liquid metal cooled reactors as well as high temperature CANDU reactors.
Cu—Cl cycle presents a number of prospective advantages such as maximum cycle temperature (550° C.) allow the use of a wider range of heat sources like nuclear, solar etc; intermediate chemicals are relatively safe, inexpensive and abundant. This involves minimum solid handling as compared to other processes which allows the cycle to operate efficiently. All individual steps have been investigated and experimentally proven. One of the steps could be performed at a much lower temperature by use of low grade waste heat from the nuclear or other sources. Though, ahead of these advantages can be recognized, scale-up of equipment is needed further.
OBJECTIVE OF THE INVENTION
Broad objective of the invention is to propose a hydrogen production method which will reduce greenhouse gases and other harmful emissions, satisfies the need of efficient, sustainable, non-polluting source of energy. This is an ideal energy carrier that helps to increase our energy diversity and security by reducing our dependence on hydrocarbon-based fuels.
The principal objective of this invention is to provide an improved multi-step closed loop Cu—Cl thermochemical cycle for hydrogen production as it is a promising method to generate hydrogen as a clean fuel in the future.
Another objective of present invention is to provide an improved process for synthesis of copper oxide and oxygen production by chlorination of copper oxide as a part of multi-step thermochemical Cu—Cl cycle for hydrogen production.
Another objective of present invention is to an improved multi-step closed loop Cu—Cl thermochemical cycle which can be coupled to nuclear or solar sources to provide heat.
SUMMARY OF THE INVENTION
A method for production of hydrogen via Cu—Cl thermochemical cycle consists of five thermal reactions and one electrochemical reaction. The cycle involves six steps: (1) hydrogen production; (2) copper production; (3) drying; (4) hydrogen chloride production; (5) decomposition; (6) oxygen production. An integrated process flow sheet has been developed for production of hydrogen via Cu—Cl thermochemical cycle, which involves following reactions:
Step-1:
Hydrogen Generation
2Cu (s) + 2HCl (g) → 2CuCl (l) + H 2(g)
Reaction
Step-2:
Electrochemical
4CuCl (aq) → 2CuCl 2(aq) + 2Cu (s)
Reaction
Step-3:
Drying
2CuCl 2(aq) → 2CuCl 2(s)
Step-4:
Hydrolysis Reaction
CuCl 2(s) + H 2 O (g) → CuO (s) + 2HCl (g)
Step-5:
Decomposition
CuCl 2(s) → CuCl (l) + ½Cl 2(g)
Reaction
Step-6:
Oxygen Generation
CuO (s) + ½Cl 2(g) → CuCl (l) + ½O 2(g)
Reaction
Overall Reaction
H 2 O → H 2(g) + ½O 2(g)
A chemical reaction takes place in each step, except drying step. The chemical reactions form a closed loop which re-cycles all of the copper-chlorine compounds on a continuous basis, without emitting any greenhouse gases to the atmosphere.
But the present invention can be deduced to four basic steps of method for the production of hydrogen by thermochemical Cu—Cl cycle like.
Step 1: contacting of copper with dry hydrogen chloride (HCl) to form cuprous chloride (CuCl) and hydrogen gas Step 2: electrolysis of CuCl of step a) to produce copper and cupric chloride (CuCl 2 ) Step 3: hydrolysis of CuCl 2 of step b) to produce cupric oxide (CuO) and hydrogen chloride (HCl) Step 4: reacting CuO with chlorine to produce CuCl and oxygen gas.
and wherein CuCl 2 is partially decomposed to produce CuCl and Cl 2(g) .
A non-catalytic reaction of copper chloride particles with superheated steam in a fixed bed reactor with the effect of various reaction parameters such as effect of mole ratio of steam to copper chloride, temperature of superheated steam, flow rate of nitrogen and reaction temperature and a reaction of copper oxide particles with chlorine gas by varying the parameters such as effect of mole ratio of copper oxide to chlorine, flow rate of chlorine, flow rate of nitrogen and reaction temperature to achieve maximum conversion have been studied as a part of Copper-Chlorine (Cu—C) water splitting thermochemical cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are used to illustrate the present invention.
FIG. 1 is a representation of closed loop of thermochemical Cu—Cl cycle for hydrogen production.
FIG. 2 is a schematic view of conceptual process layout of thermochemical Cu—Cl cycle for hydrogen production.
FIG. 3 is a representation of an experimental set up used to perform the experiments cited in the examples.
STATEMENT OF THE INVENTION
A method for thermochemical production of hydrogen and oxygen from water by a six-step copper-chlorine (Cu—Cl) process involving the reactions of copper and chlorine compounds has been developed. This process forms a closed loop by recycling all the reactants and products on a constant basis, without emitting any greenhouse gases to the atmosphere. The process described herein uses a lower temperature than any other thermochemical process with the readily available and inexpensive intermediate compounds which pose little or no hazardous material harms.
A method for hydrogen production by thermochemical Cu—Cl cycle comprises hydrolysis reaction of copper chloride (Step-4) to copper oxide and hydrogen chloride gas and hydrogen chloride gas is consumed for hydrogen production (Step-1) and oxygen production step (Step-6), as a last step, which closes the cycle, by chlorination of copper oxide, produced in Step-4 and chlorine gas generated in Step-3, wherein the reactions are carried out in a flow through type quartz reactor as fixed bed type at high temperature and atmospheric pressure. The hydrolysis of copper chloride and oxygen generation reaction as a part of Cu—Cl thermochemical cycle for hydrogen production are experimentally demonstrated in proof-of-concept work, thus indicating chemical viability. The experimental data indicates that a less steam to copper chloride molar ratio is required for high conversion and high yields of CuO.
DESCRIPTION OF THE INVENTION
The present invention discloses the process for the production of hydrogen by thermochemical Cu—Cl cycle involving six reactions.
But the present invention can be deduced to four basic steps of method for the production of hydrogen by thermochemical Cu—Cl cycle like.
Step 1: contacting of copper with dry hydrogen chloride (HCl) to form cuprous chloride (CuCl) and hydrogen gas Step 2: electrolysis of CuCl of step a) to produce copper and cupric chloride (CuCl 2 ) Step 3: hydrolysis of CuCl 2 of step b) to produce cupric oxide (CuO) and hydrogen chloride (HCl) Step 4: reacting CuO with chlorine to produce CuCl and oxygen gas and wherein CuCl 2 is partially decomposed to produce CuCl and Cl 2(g) .
These reactions can be transformed in the form of closed loop of thermochemical Cu—Cl cycle wherein hydrogen production is carried out as representation in FIG. 1 .
The present invention discloses the process for the production of hydrogen by thermochemical Cu—Cl cycle involving six reactions. The reactions in the form of closed loop of thermochemical Cu—Cl cycle for hydrogen production are representation in FIG. 1 . The block diagram has been made for the Cu—Cl cycle and shown in FIG 2 .
The key components of Cu—Cl cycle are six interconnected reactors. In the hydrogen production reactor 1 , copper particles react with dry HCl gas to produce H 2(g) and CuCl (l) . Generated H 2(g) is collected and stored. The produced CuCl (l) is supplied to electrochemical step. In the electrochemical cell 2 , an aqueous solution of CuCl is electrolyzed to produce solid copper and aqueous CuCl 2 solution. The solid copper particles are then supplied to hydrogen production reactor 1 . However, an aqueous CuCl 2 solution from electrochemical cell 2 is dried in dryer 3 to produce CuCl 2 particles. The solid CuCl 2 particles are collected, conveyed and then fed to decomposition and hydrolysis reaction. In hydrolysis reactor 4 , CuCl 2 particles react with steam to produce two product streams viz. HCl (g) and CuO solid particles, where produced HCl (g) is supplied to hydrogen production reactor 1 . Simultaneously, CuCl 2 particles are fed to decomposition reactor 5 to produce CuCl (l) and Cl 2(g) . CuO solid particles from hydrolysis reaction enters the oxygen production reactor 6 where it reacts with Cl 2(g) leaving from decomposition reactor 5 to produce CuCl (l) and O 2(g) . Generated O 2(g) is collected and stored. However, CuCl (l) streams from decomposition reactor 5 and oxygen production reactor 6 are collectively supplied to electrochemical cell 2 for electrolysis.
As described above, all the chemical reactions involved form a closed loop with recycling all of the reactants and products on a continuous basis with net reaction of water splitting resulting into hydrogen and oxygen.
The results of study of hydrolysis of copper chloride (Step-5) and chlorination of copper oxide (Step-6) are discussed below.
The present invention relates to a system, including experimental set up ( FIG. 3 ) for the production of copper oxide copper oxide and hydrogen chloride gas by hydrolysis of copper chloride (Step-4) wherein hydrogen chloride gas generated is recycled to hydrogen production (Step-1) and copper oxide formed is used for oxygen production (Step-6) of thermochemical Cu—Cl cycle.
FIG. No. 3 is a representation of an experimental set up used to perform the experiments cited in the examples.
The experimental set up comprises:
a microreactor ( 1 ) made of quartz, with a capacity of approximately 50 cm 3 enclosed by furnace ( 2 ); a cylinder ( 3 ) for nitrogen; a rotameter ( 4 ) or mass flow controller ( 5 ) to control the flow of carrier gas; a cylinder ( 6 ) for hydrogen chloride or chlorine; a mass flow controller ( 7 ) or rotameter ( 8 ) to control the flow of hydrogen chloride or chlorine gas; a water collection tank ( 9 ) to supply water to vaporizer; a pump ( 10 ) to drive the liquid at calculated flow rate to vaporizer; a vaporizer ( 11 ) for generation of steam; a NaOH collection tank ( 12 ) to supply water to scrubber at a particular flow tare through rotameter ( 13 ); a scrubber ( 14 ) to scrub generated hydrogen chloride; a moisture trap ( 15 ) to trap any moisture.
As said above, present invention can be deduced to four basic steps of method for the production of hydrogen by thermochemical Cu—Cl cycle like.
Step 1: contacting of copper with dry hydrogen chloride (HCl) to form cuprous chloride (CuCl) and hydrogen gas Step 2: electrolysis of CuCl of step a) to produce copper and cupric chloride (CuCl 2 ) Step 3: hydrolysis of CuCl 2 of step b) to produce cupric oxide (CuO) and hydrogen chloride (HCl) Step 4: reacting CuO with chlorine to produce CuCl and oxygen gas and wherein CuCl 2 is partially decomposed to produce CuCl and Cl 2(g) .
Some of the embodiments of the invention can be described as follows:
One of the embodiments of present invention wherein production of hydrogen is carried out with at least one product of at least one step is used as reactant in other step. But in present method for the production of hydrogen it is found that all products of at least one step are can be recycled.
Another embodiment of the present invention is that copper and dry hydrogen chloride (HCl) can be preheated before contacting of copper with dry hydrogen chloride at temperature in the range of 300-600° C.
Another embodiment of the present invention is that electrolysis of CuCl can be carried out in aqueous condition.
Another embodiment of the present invention is that hydrolysis of CuCl 2 can be carried out to obtain solid CuO and dry hydrogen chloride (HCl). But it is found that hydrolysis of CuCl 2 can be carried out with superheated steam for effective conversion.
Another embodiment of the present invention is that reaction of CuO with chlorine is carried out to obtain molten CuCl salt and oxygen gas.
Another embodiment of the present invention is that hydrolysis of CuCl 2 can be carried out with superheated steam having temperature ranging from 200° C. to 600° C.
For effective hydrolysis, superheated steam having temperature in range of 300° C. to 500° C. can be used.
It is found that superheated steam has pressure ranging from 1 to 5 atm but pressure preferably in range of 1 to 3 atm can be used. Hydrolysis of CuCl 2 with superheated steam can also be carried out at atmospheric pressure.
Another embodiment of the present invention is that hydrolysis of CuCl 2 is carried out in temperature range of 100° C. to 800° C. but temperature range of 300° C. to 500° C. can be used preferably.
Another embodiment of the present invention is that hydrolysis of CuCl 2 with superheated steam can be carried out with mole ratio in the range 1:1 to 1:100 of steam to copper chloride. But for effective conversion preferable mole ratio in the range 1:5 to 1:30 of steam to copper chloride can be used.
Another embodiment of the present invention is that the reaction of CuO with chlorine can be carried out at a temperature in range of 300° C. to 700° C. The reaction of CuO with chlorine can also be carried out preferably in the temperature range of 450° C. to 550° C.
Another embodiment of the present invention is that the reaction of CuO with chlorine can be carried out in the mole ratio of copper oxide to chlorine ranges between 1:1 to 1:10. But this mole ratio of copper oxide to chlorine can be used preferably in ranges between 1:1 to 1:2.5. This reaction of CuO with chlorine can be carried out at atmospheric pressure.
Another embodiment of the present invention is that CuCl 2 produced in electrolysis step can be decomposed to produce CuCl and Cl 2(g) . This decomposition of CuCl 2 is carried out at a temperature in range of 300° C. to 700° C. to produce molten CuCl salt and chlorine gas. It is found that decomposition is carried out preferably in the temperature in range of 400° C. to 550° C.
Another embodiment of the present invention is that CuCl 2 can be decomposed in range of 10 to 90 percent of total CuCl 2 produced in step b). But CuCl 2 can be partially decomposed preferably in range of 40 to 60 percent of total CuCl 2 produced in step b).
Another embodiment of the present invention is that CuCl 2 obtained in step b) can be dried or in dried form. Further CuCl 2 obtained in step b) can also be partially dried.
Yet another embodiment of the present invention is that CuO obtained in step c) can have particle size in range about 0.1 to 500 microns.
Yet another embodiment of the present invention is that at least one product of at least one step can be used as reactant in other step to form overall a closed loop thermochemical Cu—Cl cycle reaction through intermediate copper and chlorine compounds. Further it is found that at least one product of each of the above step is used as reactant in other step.
Step 1: Hydrogen Generation as a Part of Cu—Cl Thermochemical Cycle
According to the process of present invention, hydrogen generation reaction is performed in a flow-through type quartz microreactor as a fixed bed reactor type enclosed by furnace wherein the temperature of the furnace is controlled using a PID controller and the temperature inside the reactor is monitored by K-type thermocouple placed inside the reactor.
According to the process of present invention, dry hydrogen chloride gas required for reaction is supplied through mass flow controller to the reactor through the quartz tube extended to the bottom of the reactor.
According to the process of present invention, dry hydrogen chloride gas is diluted with inert gas such as nitrogen. Carrier gas facilitates continuous removal of generated hydrogen gas during the reaction.
According to the process of present invention, the outlet of the reactor is connected to the scrubber to scrub the unreacted hydrogen chloride gas.
According to invention, hydrogen generation reaction is carried out in quartz microreactor with mole ratio of Cu to dry hydrogen chloride gas flow rate in the range between 1:1 to 1:10.
According to invention, hydrogen generation reaction is carried out in quartz microreactor with mole ratio of dry hydrogen chloride gas to nitrogen in the range between 1:0 to 1:10.
According to invention, hydrogen generation reaction is carried out in quartz microreactor with reaction temperature in the range between 300° C. to 600° C.
According to invention, hydrogen generation reaction is carried out in quartz microreactor with particle size of copper in the range between 1 μm to 2000 μm.
Step 3: Hydrolysis of Copper Chloride as a Part of Cu—Cl Thermochemical Cycle
According to the process of present invention, hydrolysis reaction is performed in a flow-through type quartz microreactor as a fixed bed reactor type enclosed by furnace wherein the temperature of the furnace is controlled using a PID controller and the temperature inside the reactor is monitored by K-type thermocouple placed inside the reactor.
According to the process of present invention, the steam required for reaction is supplied to the reactor through the quartz tube extended to the bottom of the reactor wherein water at a calculated flow rate is pumped through the pump to the vaporizer to produce steam.
According to the process of present invention, the steam temperature is maintained at desired condition by line heaters up to reactor.
According to the process of present invention, the steam used is diluted with inert gas such as nitrogen. Carrier gas facilitates continuous removal of generated hydrogen chloride during the reaction.
According to the process of present invention, the outlet of the reactor is connected to the scrubber to scrub the hydrogen chloride generated in-situ.
The present invention will be further illustrated by the following examples, which are merely representative but are not intended to restrict the scope of the present invention in any way.
Step 4: Chlorination of Copper Oxide as a Part of Cu—Cl Thermochemical Cycle
The present invention relates to a system, including experimental set up FIG. 3 for the production of oxygen by chlorination of copper oxide (Step-6) wherein chlorine gas generated in decomposition reaction (Step-4) is utilized and cuprous chloride formed is given for electrolysis (Step-2) of thermochemical Cu—Cl cycle.
According to the process of present invention, oxygen generation reaction is performed in quartz microreactor as a fixed bed reactor type enclosed by furnace wherein the temperature of the furnace is controlled using a PID controller and the temperature inside the reactor is monitored by K-type thermocouple placed inside the reactor.
According to the process of present invention, dry chlorine gas required for reaction is supplied through mass flow controller to the reactor through the quartz tube extended to the bottom of the reactor.
According to the process of present invention, dry chlorine gas is diluted with inert gas such as nitrogen. Carrier gas facilitates continuous removal of generated oxygen gas during the reaction.
According to the process of present invention, the outlet of the reactor is connected to the scrubber to scrub the unreacted chlorine.
According to invention, chlorination reaction is carried out in quartz microreactor with chlorine flow rate in the range between 5 to 30 cm 3 /min.
According to invention, chlorination reaction is carried out in quartz microreactor with mole ratio of CuO to chlorine flow in the range between 1:0.5 to 1:2.5.
Step 5: Decomposition of Copper Chloride as a Part of Cu—Cl Thermochemical Cycle
According to the process of present invention, decomposition reaction is performed in a flow-through type quartz microreactor as a fixed bed reactor type enclosed by furnace wherein the temperature of the furnace is controlled using a PID controller and the temperature inside the reactor is monitored by K-type thermocouple placed inside the reactor.
According to the process of present invention, inert gas such as nitrogen is supplied through mass flow controller to the reactor to facilitate continuous removal of generated chlorine gas during the reaction.
According to the process of present invention, the outlet of the reactor is connected to the scrubber to scrub generated chlorine gas.
EXAMPLES
Example 1-5
According to the described disclosure of the invention following experiments are conducted in a quartz microreactor. The reaction is carried out as fixed bed reactor type. The dry hydrochloric acid gas required for reaction is supplied through mass flow controller to the reactor through quartz tube extended to the bottom of the reactor. The reaction is carried out at atmospheric pressure. The dry hydrochloric acid gas is introduced in the reactor at a desired flow rate. The results are presented in Table 1. The reactions are performed at the following operating conditions:
Cu: 0.015 moles (1 g) Molar ratio of HCl/Cu: 5:1 Size of Cu: 3-5 μm N 2 flow rate: 15 cm 3 /min.
TABLE 1
Example
Temperature
Conversion
No.
(° C.)
(%)
1
300
20
2
425
72
3
450
81
4
475
82
5
525
86
Example 6-8
According to the described disclosure of the invention following experiments are conducted in a quartz microreactor. The reaction is carried out as fixed bed reactor type. The dry hydrochloric acid gas required for reaction is supplied through mass flow controller to the reactor through quartz tube extended to the bottom of the reactor. The reaction is carried out at atmospheric pressure. The dry hydrochloric acid gas is introduced in the reactor at a desired flow rate. The results are presented in Table 2. The reactions are performed at the following operating conditions:
Cu: 0.015 moles (1 g) Molar ratio of HCl/Cu: 1:1 Size of Cu: 3-5 μm Temperature: 450° C.
TABLE 2
Example
N 2 flow rate
Conversion
No.
(cm 3 /min.)
(%)
6
0
90
7
15
92
8
30
95
Example 9-11
According to the described disclosure of the invention following experiments are conducted in a quartz microreactor. The reaction is carried out as fixed bed reactor type. The dry hydrochloric acid gas required for reaction is supplied through mass flow controller to the reactor through quartz tube extended to the bottom of the reactor. The reaction is carried out at atmospheric pressure. The dry hydrochloric acid gas is introduced in the reactor at a desired flow rate. The results are presented in Table 3. The reactions are performed at the following operating conditions:
Cu: 0.015 moles (1 g) Size of Cu: 3-5 μm Temperature: 450° C. N 2 flow rate: 50 cm 3 /min.
TABLE 3
Example
Molar ratio of
Cu Conversion
No.
HCl/Cu
(%)
9
1:1
70
10
4:1
92
11
6:1
95
Example 12-15
According to the described disclosure of the invention following experiments are conducted in a quartz microreactor. The reaction is carried out as fixed bed reactor type. The dry hydrochloric acid gas required for reaction is supplied through mass flow controller to the reactor through quartz tube extended to the bottom of the reactor. The reaction is carried out at atmospheric pressure. The dry hydrochloric acid gas is introduced in the reactor at a desired flow rate. The results are presented in Table 3. The reactions are performed at the following operating conditions:
Cu: 0.015 moles (1 g) Molar ratio of HCl/Cu: 4:1 Temperature 450° C. N 2 flow rate: 15 cm 3 /min.
TABLE 4
Example
Size of Cu
Conversion
No.
(μm)
(%)
12
10
95
13
40
88
14
150
55
15
500
30
Example 16-21
According to the described disclosure of the invention following experiments are conducted in a quartz microreactor. The reaction is carried out as fixed bed reactor type. The steam required for reaction is supplied to the reactor through quartz tube extended to the bottom of the reactor. The reaction is carried out at atmospheric pressure. The steam is introduced in the reactor at a desired flow rate. The results are presented in Table 5. The reactions are performed at the following operating conditions:
Copper chloride: 0.00743 moles (1 g) Reaction temperature: 500° C. Steam temperature: 550° C. N 2 flow rate: 30 cm 3 /min.
TABLE 5
Example
Steam/CuCl 2
Conversion
No.
Mole ratio
(%)
16
1:2
50
17
1:5
72
18
1:15
85
19
1:20
90
20
1:30
93
21
1:50
97
Example 22-26
According to the described disclosure of the invention following experiments are conducted in a flow through type quartz microreactor. The reaction is carried out as fixed bed reactor type. The steam required for reaction is supplied to the reactor through quartz tube extended to the bottom of the reactor. The reaction is carried out at atmospheric pressure. The steam is introduced in the reactor at a constant flow rate. The results are presented in Table 6. The reactions are performed at the following operating conditions:
Copper chloride: 0.00743 moles (1 g) Steam/CuCl 2 mole ratio: 1:15 Reaction temperature: 500° C. N 2 flow rate: 10 cm 3 /min.
TABLE 6
Steam
Example
Temperature
Conversion
No.
(° C.)
(%)
22
250
90.5
23
300
90.6
24
350
91.9
25
400
91.9
26
500
92
Example 27-29
According to the described disclosure of the invention following experiments are conducted in a flow through type quartz microreactor. The reaction is carried out as fixed bed reactor type. The steam required for reaction is supplied to the reactor through quartz tube extended to the bottom of the reactor. The reaction is carried out at atmospheric pressure. The steam is introduced in the reactor at a constant flow rate. The results are presented in Table 7. The reactions are performed at the following operating conditions:
Copper chloride: 0.00743 moles (1 g) Steam/CuCl 2 mole ratio: 1:20 Steam temperature: 400° C. N 2 flow rate: 10 cm 3 /min.
TABLE 7
Reaction
Example
Temperature
Conversion
No.
(° C.)
(%)
27
300
35.8
28
400
85.6
29
500
95
Example 30-33
According to the described disclosure of the invention following experiments are conducted in a quartz microreactor. The reaction is carried out as fixed bed reactor type. The dry chlorine gas required for reaction is supplied through mass flow controller to the reactor through quartz tube extended to the bottom of the reactor. The reaction is carried out at atmospheric pressure. The dry chlorine gas is introduced in the reactor at a desired flow rate. The results are presented in Table 8. The reactions are performed at the following operating conditions:
Copper oxide: 0.01 moles (0.795 g) CuO/Cl 2 mole ratio: 1:5 Reaction temperature: 525° C. N 2 flow rate: 15 cm 3 /min.
TABLE 8
Example
Cl 2 Flow rate
Conversion
No.
(cm 3 /min)
(%)
30
5
66
31
10
74
32
15
84
33
20
80
Example 34-37
According to the described disclosure of the invention following experiments are conducted in a quartz microreactor. The reaction is carried out as fixed bed reactor type. The dry chlorine gas required for reaction is supplied through mass flow controller to the reactor through quartz tube extended to the bottom of the reactor. The reaction is carried out at atmospheric pressure. The dry chlorine gas is introduced in the reactor at a constant flow rate. The results are presented in Table 9. The reactions are performed at the following operating conditions:
Copper oxide: 0.01 moles (0.795 g) Reaction temperature: 550° C. N 2 flowrate: 15 cm 3 /min.
TABLE 9
Example
CuO:Cl 2
Conversion
No.
Mole Ratio
(%)
34
1:1
54
35
1:2
65
36
1:4
84
37
1:6
90
Example 38-40
According to the described disclosure of the invention following experiments are conducted in a quartz microreactor. The reaction is carried out as fixed bed reactor type. The dry chlorine gas required for reaction is supplied through mass flow controller to the reactor through quartz tube extended to the bottom of the reactor. The reaction is carried out at atmospheric pressure. The dry chlorine gas is introduced in the reactor at a constant flow rate. The results are presented in Table 10. The reactions are performed in the following operating conditions:
Copper oxide: 0.01 moles (0.795 g) N 2 flow rate: 15 cm 3 /min.
TABLE 10
Reaction
Example
Temperature
Conversion
No.
(° C.)
(%)
38
400
15
39
500
75
40
550
84
Example 41-43
According to the described disclosure of the invention following experiments are conducted in a quartz microreactor. The reaction is carried out as fixed bed reactor type. The results are presented in Table 11. The reactions are performed at the following operating conditions:
Copper chloride: 0.01 mol (1.345 g) N 2 flow rate: 15 cm 3 /min.
TABLE 11
Example
Reaction
Conversion
No.
Temperature (° C.)
(%)
41
400
5
42
450
30
43
550
85 | The present invention discloses a method for thermochemical production of hydrogen and oxygen from water by a low temperature, multi-step, closed, cyclic copper-chlorine (Cu—Cl) process involving the reactions of copper and chlorine compounds. A method for production of hydrogen via Cu—Cl thermochemical cycle consists of four thermal reactions and one electrochemical reaction and one unit operation. The cycle involves six steps: (1) hydrogen production step; (2) copper production step; (3) drying step; (4) hydrogen chloride production step; (5) decomposition step; (6) oxygen production step. The net reaction of the sequential process is the decomposition of water into hydrogen and oxygen. The methods for production of copper oxide which comprises contacting copper chloride particles with superheated steam and production of oxygen comprises reaction of copper oxide with dry chlorine as a part of hydrogen production by thermochemical Copper-Chlorine (Cu—Cl) cycle. The reactions are performed in a flow through type quartz reactor as fixed bed type at high temperature and atmospheric pressure. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a process for chemically modifying nonwoven textile articles to impart pilling resistance and soil release properties to the article without compromising the strength and abrasion resistance of the article.
Nonwoven textile articles have historically possessed many attributes that led to their use for many items of commerce, such as air filters, furniture lining, and vehicle floorcovering, side panel and molded trunk linings. Among these attributes are lightweightness of the products, low cost and simplicity of the manufacturing process, and various other advantages. More recently, technological advances in the field of nonwovens, in areas such as abrasion resistance, fabric drape, fabric softness, and wash durability, have created new markets for nonwoven materials. For example, U.S. Pat. Nos. 5,899,785 and 5,970,583, both assigned to Freudenberg, describe a nonwoven lap of very fine continuous filament and the process for making such nonwoven lap using traditional nonwoven manufacturing techniques. The raw material for this process is a spun-bonded composite, or multi-component, fiber that is splittable along its length by mechanical or chemical action. As an example, after a nonwoven lap is formed, it may be subjected to high-pressure water jets which cause the composite fibers to partially separate along their length and become entangled with one another thereby imparting strength and microfiber-like softness to the final product. One such product manufactured and made available by Freudenberg according to these processes is known as Evolon®, and it is available in standard or point bonded variations. These manufacturing techniques allow for the efficient and inexpensive production of nonwoven fabrics having characteristics, such as strength, softness, and drapeability, equal to those of woven or knitted fabrics, which have end uses in products such as apparel, cleaning cloths, and artificial leather.
With the emergence of nonwovens into these new markets and increased consumer interest in such products, there has been a desire to produce fabrics with other characteristics, in addition to strength, similar to those of woven or knitted fabrics. Some of these characteristics include pilling resistance and soil release. Pilling typically results from fibers being pulled out of the fiber bundle and becoming entangled into a “ball” due to mechanical action, such as rubbing that, for example, fabrics encounter during normal use. These “pill balls” are a detriment to the appearance and comfort of textile articles. Reducing or eliminating the pilling propensity of textile articles would typically extend the useful life of the end-use product, such as a garment, by retaining its original appearance and comfort. Furthermore, soil release properties have obvious considerable importance for end-use products such as children's clothing, napery, and cleaning cloths since it is desirable to maintain the original appearance of these products for aesthetic reasons. Thus, it is an important attribute for nonwoven articles to possess pilling resistance and soil release characteristics without compromising strength and abrasion resistance of the articles for their emergence into these new markets.
SUMMARY OF THE INVENTION
In light of the foregoing discussion, it is one object of the current invention to achieve a nonwoven textile article which has been chemically modified to possess pilling resistance, soil release, and acceptable strength characteristics. Textile articles include fabrics, films, and combinations thereof. By pilling resistant, it is meant that the article achieves a minimum “B” rating after 18,000 cycles under a 9 kPa weight when tested for Martindale Pilling according to ASTM D4970 and using the Marks & Spencer Test Method P17 and rating the article on the Marks & Spencer Holoscope. Soil release is determined according to test method AATCC Method 130-2000 and is found to be acceptable for articles that achieve a minimum 3.0 rating after one wash cycle. The amount of strength that will generally be considered to be “acceptable” is the strength required for the treated article to function within its anticipated end product for a minimum number of use or wear cycles, which will generally also include intermittent cleaning cycles as well. The strength that is considered to be acceptable for a given article will therefore vary depending on the type of treated article, how it will be used in an end product, the type of end product, etc. By way of example, acceptable strength for an article intended for use as apparel is achieved with a minimum 2000 cycles when tested for Flex Abrasion according to ASTM D 3885. More specifically, by experience it has been determined that a certain nonwoven fabric comprised of spun-bonded continuous multi-component splittable fibers, wherein the fibers are 65% polyester and 35% nylon 6 or nylon 6,6, to be used in shirting should achieve a minimum of 2000 cycles when tested according to ASTM D 3885. Other standard methods for evaluating the pilling resistance, soil release, and abrasion resistance of fabrics may be used and are known and available to those skilled in the art.
A second object of the current invention is to achieve a nonwoven textile article, which has been chemically modified, that maintains its aesthetic appearance and comfort properties due to its resistance to pilling. The formation of “pill balls” leads to an unsightly appearance of the article. In addition, these “pill balls,” when found in a garment, for example, generally result in a loss of garment comfort due to the abrasive nature of these protrusions against the skin. Therefore, reducing or eliminating the formation of “pill balls” allows for the extension of the useful life of textile articles, such as apparel, made from nonwoven fabric.
A further object of the current invention is to achieve a nonwoven textile article, which has been chemically modified, that maintains its aesthetic appearance due to its soil release characteristics. For example, garments or napery articles having food or soil stains are typically detracting to the appearance of those items. Thus, treating nonwoven textile articles with soil release chemicals would generally preserve the appearance of those articles and thereby extend the useful of those articles.
It is also an object of the current invention to achieve a method for chemically modifying nonwoven textile articles to impart pilling resistance and soil release properties to the articles while at the same time maintaining acceptable strength and abrasion resistance characteristics.
A further object of the current invention is to achieve a composition of matter for chemically modifying a nonwoven textile article to achieve pilling resistance, soil release, strength and abrasion resistance comprising a hydrophilic silicone, a soil release agent, an abrasion resistance agent, water, and optionally, a wetting agent and a defoaming agent.
Other objects, advantages, and features of the current invention will occur to those skilled in the art. Thus, while the invention will be described and disclosed in connection with certain preferred embodiments and procedures, such embodiments and procedures are not intended to limit the scope of the current invention. Rather, it is intended that all such alternative embodiments, procedures, and modifications are included within the scope and spirit of the disclosed invention and limited only by the appended claims and their equivalents.
DETAILED DESCRIPTION OF THE INVENTION
A nonwoven textile article is provided that has been chemically modified to achieve a useful change in certain of its properties. U.S. Pat. Nos. 5,899,785 and 5,970,583, both incorporated herein by reference, describe the composition and process for manufacturing the nonwoven lap that is the basis for the nonwoven textile article that is chemically modified by the current invention. Typically, the nonwoven article is a fabric comprised of spun-bonded continuous multi-component filament fiber that has been split, either partially or wholly, into its individual component fibers by exposure to mechanical or chemical means, such as high-pressure fluid jets. The fabric composition is generally 65% polyester fiber and 35% nylon 6 or nylon 6,6 fiber, although other fiber variations and combinations described by the above-mentioned patents are contemplated to be within the scope of this invention.
The process for chemically treating the nonwoven article, typically a fabric made from polyester and nylon composite fibers, involves the use of several chemicals combined in a mixture. The chemicals typically function as wetting agents, defoaming agents, soil release agents, pilling resistance agents, and abrasion resistance agents.
Generally, the wetting agents are ethoxylated long chain alcohols, such as Solpon® 839 available from Boehme Filatex, such that the long chains comprise at least 9 carbon atoms. Without being bound by theory, it is thought that the wetting agent improves adhesion, and possibly the chemical reaction that occurs, between the fabric and the other chemicals in the mixture. Because the untreated fabric typically tends to be inherently hydrophilic (approximately 100% wet pickup on weight of fabric in laboratory scale testing), the use of a wetting agent is optional. However, if a wetting agent is employed, concentrations typically range from between about 0.20 and about 0.30 weight percent on weight of the chemical mixture.
Depending on the specific mixture of chemicals applied to the fabric, a defoaming agent may be needed to reduce foam during the manufacturing process. For example, a mineral oil such as Tebefoam® VP1868 available from Boehme Filatex may be used. Other defoamers include silicone defoamers and de-aerating agents. The use of a defoamer is generally optional. However, if a defoamer is employed, typical concentrations may range from between about 0.05 and about 2 weight percent on weight of the chemical mixture.
Chemicals used to impart pilling resistance to the fabric are typically hydrophilic silicones (such as SilTouch® SRS available from Yorkshire PatChem). It is generally known to those skilled in the art that silicones usually hinder the pilling characteristics of fabrics. However, with the unique combination of chemicals employed in this invention, these silicones have actually been found to improve the pilling resistance of these fabrics. Typical concentrations for hydrophilic silicones range from between about 2 and about 8 weight percent on weight of the chemical mixture.
Soil release chemicals are typically chosen from acrylic compounds (such as Millitex® PD 75 available from Milliken Chemical), fluorocarbon compounds (such as Zonyl® 7910 available from Ciba Specialty Chemicals), or liquid polyesters (such as Millitex® PD 92 available from Milliken Chemical). The soil release chemicals have a tendency to form films around the fibers. Typical concentrations of acrylic soil release chemicals range from between about 2 and about 12 weight percent on weight of the chemical mixture. Concentrations of fluorocarbon soil release compounds generally range from between about 0.5 and about 6 weight percent on weight of the chemical mixture, and concentrations of liquid polyester soil release compounds generally range from between about 2 and about 6 weight percent on weight of the chemical mixture.
Chemicals used to impart abrasion resistance and strength to the fabric are generally polyethylenes (such as Aqualene N available from Moretex) or polyurethanes (such as Prote-set FAI available from Synthron, Inc). Generally, polyethylenes with a higher melting point (usually referred to as high-density polyethylenes), such as greater than about 124 degrees Celsius, are preferred over low melting point polyethylenes (usually referred to as low-density polyethylenes), and they tend to form films around the fiber similar to the films formed by the soil release chemicals. Typical concentrations of polyethylenes range from between about 8 and about 16 weight percent on weight of the chemical mixture, while typical concentrations of polyurethanes range from between about 6 and about 18 weight percent on weight of the chemical mixture. Interestingly, the hydrophilic silicones, mentioned previously as pilling resistance chemicals, also tend to enhance the abrasion resistance of the fabric, while the polyethylenes mentioned above as abrasion resistance chemicals tend to enhance the pilling resistance of the fabric. It has been generally found that an intimate relationship exists between the use these two types of chemicals for generally enhancing both the abrasion resistance and the pilling resistance of the nonwoven textile article.
It should be noted that the concentrations of the chemicals used to treat the nonwoven textile articles can be varied within a relatively broad range, depending on the amount of pilling resistance and the amount of soil release desired for a particular end-use product, and is related to the inherent strength of the textile article to be processed. The inherent strength of the fiber which will ultimately be treated with the chemical mixture generally varies between different manufacturers of the fiber and between fiber types. As a result, these characteristics typically need to be examined in determining the concentration and amount of chemical to be used for a given treatment.
In one aspect of the invention, the process of the current invention requires no special equipment; standard textile dyeing and finishing equipment can be employed. By way of example, a nonwoven textile fabric may be treated either in a batch operation, wherein chemical contact is prolonged, or in a continuous operation, wherein chemical contact with the fabric is shorter. Generally, a predetermined amount of the desired chemical mixture is deposited onto the article, and the treated article is then dried, typically by exposing the article to a sufficient amount of heat for a predetermined amount of time. The application of the chemical mixture to the article may be accomplished by immersion coating, padding, spraying, foam coating, or by any other technique whereby one can apply a controlled amount of a liquid suspension to an article. Employing one or more of these application techniques may allow the chemical to be applied to a textile article in a uniform manner. As noted above, once the chemical has been applied to the article, the article is dried, generally by subjecting the article to heat. Heating can be accomplished by any technique typically used in manufacturing operations, such as dry heat from a tenter frame, microwave energy, infrared heating, steam, superheated steam, autoclaving, etc. or any combination thereof. The article may be dyed or undyed prior to chemical treatment. If undyed before treatment, the article may be dyed or printed after treatment. The article may also be subjected to various face-finishing processes and sanforization after chemical treatment. For example, U.S. Pat. Nos. 5,822,835, 4,918,795, and 4,837,902, incorporated herein by reference, disclose a face-finishing process wherein low pressure streams of gas are directed at high velocity to the surface of a fabric. The process ultimately softens and conditions the fabric due to vibration caused from airflow on the fabric.
The following examples illustrate various embodiments of the present invention but are not intended to restrict the scope thereof. In all examples, all percentages are by weight percent of the total chemical mixture (i.e., percent on weight of the chemical bath), unless otherwise noted.
All examples utilized nonwoven fabric comprised of spun-bonded continuous multi-component fibers which have been exposed to mechanical or chemical processes to cause the multi-component fibers to split, at least partially, along their length into individual polyester and nylon 6,6 fibers, according to processes described in the two Freudenberg patents earlier incorporated by reference. The fabric, known by its product name as Evolon®, was obtained from Firma Carl Freudenberg of Weinheim, Germany.
Pilling was determined by Martindale Pilling according to ASTM D4970 and the Marks & Spencer Test Method P17, wherein “A” indicates optimal pilling resistance and “E” indicates poor pilling resistance, when rating the fabric on the Marks & Spencer Holoscope. The Martindale Pilling exposed the fabric to a 9 kPa weight (595 grams) for 18,000 revolutions, or cycles. A Home Laundry Tumble Dry (HLTD) wash procedure was also incorporated as part of the Martindale Pilling test method. The HLTD involves washing the fabric in a standard residential washing machine at 105 degrees F for 12 minutes using 10 g of Tide® laundry detergent (available from Procter & Gamble) at the high water level setting. The fabric was then dried in a standard residential dryer for 45 minutes on the cotton sturdy setting. A 4-pound load of laundry comprised of the test fabric and non-test (or “dummy”) fabric was used for each test.
Soil release was determined by AATCC Method 130-2000 using a scale from 1 to 5, wherein “5” indicates optimal soil release and “1” indicates poor soil release. Corn oil was applied to the fabric as the staining agent, and the fabric was rated for soil release after one wash (indicated as “0/1”) and two washes (indicated as “0/2”). Further testing in some examples below includes staining the fabric again after the fourth wash and rating the fabric for soil release after the fifth wash (indicated as “4/5”) and the sixth wash (indicated as “5/6”).
Abrasion resistance and strength were determined by a variety of methods: (a) Flex
Abrasion, according to ASTM D3885; (b) Stoll Flat Abrasion, according to ASTM D3886; (c) Elmendorf Tear, according to ASTM D1424, wherein the warp direction was estimated to be the direction the fabric entered and exited the machine during manufacturing (machine direction), and the fill direction was estimated to be perpendicular to the machine direction; (d) Trap Tear, according to ASTM D5587, wherein the test was performed on the warp, or machine direction of the fabric; and (e) Grab Tensile, according to ASTM D5034, wherein the test was performed on the warp, or machine direction of the fabric.
Note that “N/T” indicates that a sample was not tested for a given parameter.
EXAMPLE 1
The following example shows treatment of the nonwoven fabric with the chemical mixture of the current invention in a laboratory setting. The fabric utilized here was 100 g/m 2 point bonded Evolon®.
A one-liter solution of the desired chemical mixture was place in a beaker. The solution was comprised of 0.25% wetting agent (Synthropol® KB from Clariant), 4.0% hydrophilic silicone (Duosoft® OH from Boehme Filatex), 2.0% fluorocarbon (Zonyl® 7910 from Ciba Specialty Chemicals), 10.0% polyethylene (Atebin® 1062 from Boehme Filatex), and 83.75% water. The chemical mixture was then padded onto a 20″×20″ piece of fabric by placing the fabric in the beaker and coating it with the mixture. The fabric was then removed from the beaker and run through a chemical padding machine to remove excess chemical. The fabric was then hung in an oven and dried at 360 degrees F for two minutes. The results are shown in Table 1 below.
TABLE 1
Comparison of Treated Nonwoven Fabric versus Untreated
Nonwoven Fabric
Flex Abrasion
Martindale Pilling/
(# Cycles to Failure)
Marks & Spencer
Soil Release
Sample
Warp
Fill
(18,000 Cycles, 9 Kpa)
0/1
0/2
Treated
No HLTD
11,129
4144
A
3.0
3.5
1 HLTD
N/T
A
N/T
5 HLTD
N/T
A
N/T
Untreated
No HLTD
2522
2599
A
1.5
2.0
1 HLTD
N/T
E
N/T
5 HLTD
N/T
D
N/T
Several observations can be made regarding the data in Table 1. First, the chemically treated samples exhibit greater abrasion resistance than the untreated samples in both the warp estimated and fill estimated directions according to the Flex Abrasion test method. The warp direction withstands a higher amount of abrasion than the fill direction, which is most likely explicable by the fact that the warp direction is estimated as the machine direction of the fabric during the manufacturing process, which typically tends to be inherently stronger than the fill direction. Martindale Pilling shows pilling resistance is greatly enhanced after laundering for the treated fabric sample. It also indicates that the fabric is strong enough to withstand at least the minimum number of cycles typical for end-use products such as apparel, bedding, napery, and upholstery. This minimum number of cycles is typically about 2000 cycles for these end-uses. Additionally, the soil release property of the fabric is increased for both the 0/1 and 0/2 tests after chemical treatment. These factors indicate the effectiveness of the chemical treatment for achieving pilling resistance and soil release on the nonwoven textile article without compromising (and actually improving) abrasion resistance in both the warp and fill estimated directions.
EXAMPLE 2
Example 1 was repeated, except that the concentration of Zonyl® 7910, a soil release agent according to the present invention, was increased from 2.0 weight percent to 4.0 weight percent on weight of the chemical mixture. The soil release results are shown in Table 2 below.
TABLE 2
Comparison of Soil Release Concentration on
Treated Nonwoven Fabric
Soil Release Results
Sample
0/1
0/2
4/5
5/6
2.0% Zonyl ® 7910
3.0
3.5
3.0
3.5
4.0% Zonyl ® 7910
3.5
4.0
3.0
3.5
Table 2 shows that increasing the amount of soil release chemical from 2.0 to 4.0 weight percent on weight of the chemical mixture, while maintaining unchanged concentrations of the other chemicals, increases the soil release properties of the treated fabric after 1 wash and after 2 washes. These results indicate the effectiveness of the soil release chemicals at optimal concentration for the present invention.
EXAMPLE 3
The following example shows treatment of the fabric with the chemical mixture of the current invention in a manufacturing or production setting. The fabric utilized here included both 100 g/m 2 and 120 g/m 2 standard and point bonded Evolon® fabric. Some fabric samples were undyed, while others were dyed using standard dyeing techniques (both jet-dye and continuous dyeing processes) and dye formulations known to those skilled in the art.
The chemical mixture was prepared using 0.25% wetting agent (Solpon® 839 from Boehme Filatex), 10% polyethylene (Atebin® 1062 from Boehme Filatex), 6% hydrophilic silicone (Duosoft® OH from Boehme Filatex), 4% fluorocarbon (Zonyl® 7910 from Ciba Specialty Chemicals), and 79.75% water. There were ten 100-yard fabric samples treated with the chemical mixture (Samples 3-7 and 10-14) and four 100-yard control fabric samples treated only with water (Samples 1-2 and 8-9). The samples included:
Sample Number
Sample Description
1
Standard Greige, 100 g/m 2 (Control A)
2
Point Bonded Greige, 100 g/m 2 (Control B)
3
Standard Prepared For Print, 100 g/m 2
4
Point Bonded Prepared For Print, 100 g/m 2
5
Point Bonded Continuous Dyed White, 100 g/m 2
6
Point Bonded Continuous Dyed Navy, 100 g/m 2
7
Point Bonded Jet-Dyed Burgundy, 100 g/m 2
8
Standard Greige, 120 g/m 2 (Control C)
9
Point Bonded Greige, 120 g/m 2 Control D)
10
Standard Prepared For Print, 120 g/m 2
11
Standard Jet-Dyed Navy, 120 g/m 2
12
Point Bonded Jet-Dyed Green, 120 g/m 2
13
Point Bonded Jet-Dyed Tan, 120 g/m 2
14
PS33 (point bonded in herringbone pattern)
Continuous Dyed White, 120 g/m 2
The chemical mixture was padded on the fabric by dipping the fabric in the dip pad of a pin tenter range. The pad nip pressure was 55 psi with a wet pick up of 140%. The overfeed to chain speed was 2%, and all circulating fans were set on high. The vacuum slot was turned off. The fabric was then dried in the tenter by running the fabric at 40 yards per minute through the heat zones of the tenter which averaged 366 degrees F. The exhaust dampers were set at 50%, and the cooling cans were 80 degrees F. The winder oscillator was off.
After drying, the fabric was exposed to a face-finishing process (as described in U.S. Pat. Nos. 5,822,835, 4,918,795, and 4,837,902), wherein two zones of high velocity gaseous fluid were directed to the surface of the fabric in opposite directions at 20 psi and at 1.0 tension setting on the entry and exit rolls. Following this treatment, the fabric was sanforized. The fabric was then inspected and tested for abrasion resistance and strength. The results are shown in Table 3 below.
TABLE 3
Abrasion Resistance and Strength of Treated Nonwoven Fabric versus Untreated
Nonwoven Fabric
Elmendorf Tear
Trap Tear
Grab Tensile
(Pounds)
(Pounds)
(Pounds)
Stoll Flat
Flex Abrasion
Sample
Warp
Warp
Warp
(# Cycles to Failure)
(# Cycles to Failure)
1 (Control A)
1.17
6.51
65.8
518.0
602
2 (Control B)
0.56
5.04
67.5
499.3
490
Control Average
0.87
5.78
66.7
508.7
546
3
2.59
10.25
75.6
483.0
17,149
4
2.14
9.60
82.8
693.0
18,818
5
2.05
8.27
82.6
536.0
18,632
6
2.05
8.97
82.5
634.0
18,674
7
2.22
8.70
75.4
N/T
N/T
Sample 3-7 Average
2.21
9.16
79.8
586.5
18,318
8 (Control C)
1.07
6.57
80.4
602.0
475
9 (Control D)
0.75
4.85
85.3
758.7
675
Control Average
0.91
5.71
82.9
680.4
575
10
3.01
10.09
84.2
693.0
19,673
11
3.15
11.49
85.4
1033.0
N/T
12
2.95
14.98
96.7
1299.0
14,797
13
2.87
12.43
93.2
N/T
N/T
14
2.33
9.97
105.6
1104.0
19,708
Sample 10-14 Average
2.86
11.79
93.0
1032.3
18,059
Several observations can be made regarding the results shown in Table 3. All of the treated samples, both the 100 g/m 2 and 120 g/m 2 fabrics, exhibit improved abrasion resistance after treatment with the chemical mixture of the present invention. The heavier weight 120 g/m 2 samples, both treated and untreated, generally exhibited higher strength and abrasion resistance characteristics. Exposure of the fabric to a wide variety of different abrasion and strength tests as shown in this example confirms the usefulness and applicability of this fabric treatment for a large array of end-use applications as previously discussed.
The above description and examples show that the present invention provides a novel method for imparting pilling resistance and soil release properties to nonwoven textile articles without compromising the strength and abrasion resistance characteristics of the articles. Accordingly, the invention has many applicable uses for incorporation into articles of apparel, bedding, residential upholstery, commercial upholstery, automotive upholstery, napery, residential and commercial cleaning cloths, and any other article wherein it is desirable to manufacture a pilling resistant product with soil release properties that retains its required strength and abrasion resistance characteristics for its intended end use.
The above description and examples also provide a novel composition of matter for imparting pilling resistance, soil release, strength, and abrasion resistance properties to nonwoven textile articles. The composition of matter comprises a hydrophilic silicone, a soil release agent, an abrasion resistance agent, water, and optionally a wetting agent and a defoaming agent. The concentration of the hydrophilic silicone is between about 2 and about 8 weight percent on weight of the composition of matter. The soil release agents are selected from the group consisting of acrylics, fluorocarbons, liquid polyesters, and combinations thereof. The concentration of acrylic is between about 2 and about 12 weight percent on weight of the composition of matter. The concentration of fluorocarbon is between about 0.5 and about 6 weight percent on weight of the composition of matter. The concentration of liquid polyester is between about 2 and about 6 weight percent on weight of the composition of matter. The abrasion resistance chemicals are selected from the group consisting of polyethylenes, polyurethanes, and combinations thereof. The concentration of polyethylene is between about 8 and about 16 weight percent on weight of the composition of matter. Generally, polyethylenes with a higher melting point (usually referred to as high-density polyethylenes), such as greater than about 124 degrees Celsius, are preferred over low melting point polyethylenes (usually referred to as low-density polyethylenes). The concentration of polyurethane is between about 6 and about 18 weight percent on weight of the composition of matter. A wetting agent, such as an ethoxylated long chain alcohol wherein the chain is at least 9 carbon atoms long, may be included as a component of this composition of matter in concentrations of between about 0.2 and about 0.3 weight percent on weight of the composition of matter. A defoaming agent, such as mineral oil, silicone defoamers, and de-aerating agents, may be included as a component of this composition of matter in concentrations of between about 0.05 and about 2 weight percent on weight of the composition of matter.
These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the scope of the invention described in the appended claims. | A chemically modified nonwoven textile article and method for producing the same is provided that exhibits pilling resistance, soil release, strength, and abrasion resistance properties, thus rendering the article less prone to the formation of objectionable pill balls, staining, or loss of strength, thereby increasing wearer comfort and retaining the desired appearance of the article, and thereby extending the useful life of the article. A composition of matter for chemically modifying a nonwoven textile article to achieve pilling resistance, soil release, strength, and abrasion resistance is also provided. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority of U.S. Ser. No. 61/015,423 filed on Dec. 20, 2007.
FIELD OF INVENTION
[0002] Waterborne coatings having good, blush resistance and resistance to common household contaminants are described. The coatings comprise polymers from a) ethylenically unsaturated monomers phosphorus containing monomer, b) carbonyl containing monomer and crosslinking system, and either a phosphate surfactant and/or polymerizable surfactant.
BACKGROUND OF THE INVENTION
[0003] Waterborne coatings are commonly applied to a wide variety of substrates, such as wood, metal, masonry, plaster, stucco, and plastic. In many of these applications the coating, which is based, upon an emulsion polymer, is exposed to wet environments caused by rain, dew, snow and other sources of water. The coating is exposed to water for prolonged periods of time in some applications. However, waterborne coatings especially clear aqueous coatings, tend to blush or whiten when exposed to water. Some prior arts had addressed this issue by using self-crosslinking approaches.
[0004] U.S. Pat. No. 4,267,091 disclosed the use of carbonyl groups containing monomers, water soluble aliphatic dihydrazide and metal salts such as zinc salt to improve water whitening (blushing).
[0005] U.S. Pat. No. 4,959,428 disclosed the use of a water soluble carbonyl containing copolymer as polymeric dispersant to make emulsion polymers to enhance anti-whitening.
[0006] U.S. Pat. No. 4,654,397, U.S. Pat. No. 5,447,970, U.S. Pat. No. 5,472,996, U.S. Pat. No. 6,117,936, U.S. Pat. No. 6,512,042, U.S. Pat. No. 6,515,042 and U.S. Pat. No. 6,538,062 disclosed the polymers with carbonyl containing monomers to enhance coating properties.
[0007] Some prior arts also taught the approaches to reduce water-whitening; however, they are not suitable for coating applications.
[0008] U.S. Pat. No. 6,515,042 B2 and U.S. Patent 2005/0245662 A1 disclosed styrene containing emulsion polymers with polymerizable surfactants for improving water-whitening resistance of pressure sensitive adhesives.
[0009] WO 2004/029172 disclosed the use of monomers containing aldehyde or ketone groups and polymerizable surfactants to enhance water whitening resistance for removable pressure sensitive adhesives.
[0010] None of the prior arts addressed the issue of early water blushing or whitening resistance for coating applications. There is currently a need for waterborne varnishes and water sealers having good early water blushing resistance, such as after two to four hours of dry time under normal conditions, to sustain unexpected rain, sprinkler water, or swimming pool water. None of the prior arts taught the disclosed polymer compositions for early water blushing resistance.
[0011] Waterborne coatings also frequently offer poor resistance to chemicals that are commonly used in homes and offices, such as gasoline, motor oil, brake fluid, transmission fluid, household cleaners, window cleaning fluids, antifreeze, and the like. The prior arts mentioned above have taught the use of carbonyl containing monomers to enhance resistance to chemicals. It is also desirable for such waterborne coatings to offer good adhesion to typical substrates and a high level of resistance to common chemicals. Such waterborne coating compositions would be of particular value for utilization in painting masonry structures, such as concrete, tile, or brick surfaces.
SUMMARY OF THE INVENTION
[0012] This invention discloses a polymer that is of particular value for utilization in manufacturing waterborne coating formulations, such as varnishes, water sealers, and paints. The coatings made with these polymers offer excellent early water blushing and whitening resistance and are not prone to water spotting or blushing on exposure to water. They also offer excellent resistance to common household chemicals, such as gasoline, motor oil, brake fluid, transmission fluid, household cleaners, window cleaning fluids, antifreeze, and the like.
[0013] The polymers of this invention are of value for utilization in manufacturing coating compositions, such as paints or varnishes, for use on virtually any type of substrate including wood, metal, masonry, plaster, stucco, or plastic. By virtue of their high level of water resistance they are of particular value for use in making exterior paints, varnishes, and water sealers. They also have excellent characteristics for utilization in making coatings for masonry structures. For instance, the polymers of this invention are of particular value for use in making paints and water sealers for application to garage floors and concrete driveways. This is because they adhere well to concrete and are resistant to water, gasoline, motor oil, brake fluid, transmission fluid, antifreeze, and a wide variety of other chemicals that are commonly spilled onto garage floors and concrete driveways.
[0014] The present invention more specifically discloses a waterborne coating composition which is comprised of (1) water; (2) an emulsion polymer composition which is comprised of: (a) 0.5 weight percent to 15 weight percent of a carbonyl functionalized monomer, (b) 0.1 weight percent to 10 weight percent of a phosphorous containing monomer, and (c) 0.05 weight percent to 5 weight percent of a phosphate surfactant or a polymerizable surfactant; and (3) at least one coalescing aid.
[0015] The subject invention also reveals an emulsion polymer which is comprised of (a) 0.5 weight percent to 0.15 weight percent of a carbonyl functionalized monomer, (b) 0.1 weight percent to 10 weight percent of a phosphorous containing monomer, and (c) 0.05 weight percent to 5 weight percent of a phosphate surfactant or a polymerizable surfactant.
DETAILED DESCRIPTION OF THE INVENTION
[0016] It was unexpectedly found that the combination of carbonyl functional monomers and phosphorous containing monomers in a polymer composition offered a much better chemical resistance than carbonyl functional monomers alone.
[0017] The polymers used in the water based coating compositions of this invention are comprised of (a) 0.5 weight percent to 15 weight percent of a carbonyl functionalized monomer, (b) 0.1 weight percent to 10 weight percent of a phosphorous containing monomer, (c) 0.05 weight percent to 5 weight percent of a phosphate surfactant or a polymerizable surfactant and optionally (d) at least a crosslinking agent having two or more hydrazide groups per molecule). The crosslinking agent is optional as it may be added at a later time when a coating composition is formulated from the polymer.
[0018] The waterborne coating compositions of this invention are, made with these polymers. Such waterborne coating compositions are comprised of (1) water; (2) an emulsion polymer composition which is comprised of: (a) 0.5 weight percent to 15 weight percent of a carbonyl functionalized monomer, (b) 0.1 weight percent to 10 weight percent of a phosphorous containing monomer, (c) 0.05 weight percent to 5 weight percent of a phosphate surfactant or a polymerizable surfactant; (d) at, least a crosslinking agent having two or more hydrazide groups per molecule); and (3) at least one coalescing aid and optionally. The crosslinking agent is optional as it may be added at a later time when a coating composition is formulated from the polymer.
[0019] Suitable phosphate surfactants for use in the present invention include those having at least one phosphate group, as well as salts thereof. Salts include but are not limited to sodium, potassium, lithium, and ammonium salts. Non-limiting examples of phosphate surfactants having at least one phosphate group and salts thereof include the mono- and di-phosphate esters of nonyl phenol ethoxylate, phosphate esters of tridecyl alcohol ethoxylate, phosphate esters of isodecyl ethoxylate, and other phosphate esters of aromatic ethoxylates and aliphatic ethoxylates, phosphate esters of C 10 -C 16 alkyl ethoxylates/propoxylates and the like; and mixtures thereof. Another class of phosphate group containing surfactants includes phosphate esters of C 10 -C 16 alkyl ethoxylates/propoxylates wherein the surfactant consists of at least 50% by weight of ethylene oxide and propylene oxide groups and the proportion of ethylene oxide groups and propylene oxide groups is in each case at least 10% by weight, based on the overall amount of the ethylene oxide groups and propylene oxide groups. Such surfactants are described in U.S. Pat. No. 6,348,528, the teachings of which are incorporated herein by reference for the purpose of illustrating phosphate surfactants that are suitable for use in making the Waterborne coating compositions of this invention.
[0020] Commercially available phosphate surfactants include those listed in McCutcheon's Emulsifiers and Detergents (2004 edition), such as Rhodafac® PE-510, RE-410, RE-610, RE-960, RK-500A, RS-410, RS-610, RS-610A-25, RS-710, and RS-960 from Rhodia Inc.; Dextrol™ OC-110, OC-15, OC-40, OC-60, and OC-70 from Dexter Chemical L.L.C.; Tryfac® 5553 and 5570 from Cogis Corporation; Klearfac® AA 270, Lutensit® and Maphos® from BASF Corporation; and the like, and mixtures thereof. In one embodiment, Dextrol™ OC-110 (nonyl phenol ethoxylate phosphate ester) from Dexter Chemical L.L.C.) is used. In another embodiment, tridecyl alcohol ethoxylate phosphate ester (Dexttol™ OC-40 from Dexter Chemical L.L.C.) is used.
[0021] Non-limiting examples of other suitable phosphates having at least one phosphorus acid group and salts thereof include phosphorous-containing acids (e.g., phosphoric acid, phosphorous acid, hypophosphorous acid, orthophosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, and metaphosphoric acid), monomethyl phosphate, monoethyl phosphate, mono n-butyl phosphate, dimethyl phosphate, diethyl phosphate, ethyl ester of phosphorous acid, and other esters of phosphorous-containing acids; and the like, and mixtures thereof. In one emnbodiment, Dextrol™ OC-70 is used.
[0022] A wide variety of polymerizable surfactants can be used in synthesizing the polymers of this invention. These polymerizable surfactants are normally either water-soluble or water-dispersible. U.S. Pat. No. 5,928,783 and U.S. Pat. No. 6,239,240 describe polymerizable surfactants of this type that can be utilized in the polymers of this invention. The teachings of U.S. Pat. No. 5,928,783 and U.S. Pat. No. 6,239,240 are incorporated herein by reference for the purpose of disclosing such polymerizable surfactants that can be employed in the practice of this invention.
[0023] The polymerizable surfactants of the invention preferably contain a hydrophilic portion selected from a sulfonate allyl amine moiety, a sulfate allyl amine moiety, or a phosphate allyl amine moiety, and a hydrophobic portion selected from —R, or a group having the formula RO—(CH 2 CH 2 O) n —; wherein R is an alkyl group or an alkyl-substituted phenyl group wherein the alkyl, group has 1 to 20 carbon atoms, preferably 10 to 18 carbon atoms, and n is an integer from 2 to 100, preferably 2 to 15. The hydrophilic portion and the hydrophobic portion are connected by means of a covalent bond. Combinations of such polymerizable surfactants can be used in preparing the polymers of this invention. Water-soluble or water-dispersible polymerizable surfactants having a terminal allyl amine moieties that are useful in synthesizing the polymers of this invention are available from Stepan Company under the Polystep® trademark. For example, Polystep® NMS-9 surfactant is a preferred polymerizable surfactant for utilization in the practice of this invention.
[0024] Numerous water-soluble or water-dispersible polymerizable surfactants having a terminal allyl amine moiety are suitable for use in making the polymers of this invention. For instance, the polymerizable surfactant can be an allyl amine salt of an alkyl benzene sulfonate having the formula 1:
[0000]
[0000] wherein R 1 is an alkyl group having 1 to 20 carbon atoms, preferably 10 to 18 carbon atoms, and X + is selected from NH 3 + , + NH 2 R 4 , or + NHR 4 R 5 , wherein R 4 and R 5 are independently selected from C 1 -C 4 alkyl or hydroxyalkyl groups. X + is preferably NH 3 + . An example of a polymerizable surfactant of this type is an allyl amine salt of dodecylbenzene sulfonate.
[0025] Another preferred polymerizable surfactant is an allyl amine salt of an alkyl ether sulfate having the formula 2:
[0000]
[0000] wherein R 2 is an alkyl group containing from 1, to 20 carbon atoms, preferably 10 to 18 carbon atoms, n is an integer from 2 to 100, preferably 2 to 15, and X + is selected from NH 3 + , + NH 2 R 4 , or + NHR 4 R 5 , wherein R 4 and R 5 are independently selected from C 1 -C 4 alkyl or hydroxyalkyl groups. X + is preferably NH 3 + . An example of a polymerizable surfactant of this type is an allyl amine salt of lauryl sulfate.
[0026] Another preferred polymerizable surfactant is an allyl amine salt of a phosphate ester having the formula 3:
[0000]
[0000] wherein R 3 is an alkyl or alkyl-substituted phenyl group wherein the alkyl group has 1 to 20 carbon atoms, n is an integer from 2 to 100, preferably 2 to 15, and X + is selected from NH 3 + , + NH 2 R 4 , or + NHR 4 R 5 , wherein R 4 and R 5 are independently selected from C 1 -C 4 alkyl or hydroxyalkyl groups. It is preferred for X + to represent NH 3 + . An example of a polymerizable surfactant of this type is an allyl amine salt of nonylphenol ethoxylate (9 moles EO) phosphate ester.
[0027] Yet another preferred polymerizable surfactant is an allyl amine salt of a sulfate having the formula R 6 —SO 3 − X + —CH 2 —CH═CH 2 , wherein R 6 is an alkyl group having 6 to 20 carbon atoms, preferably 10 to 18 carbon atoms, and X + is selected from NH 3 + , + NH 2 R 4 , or + NHR 4 R 5 , wherein R 4 and R 5 are independently selected from C 1 -C 4 alkyl or hydroxyalkyl groups. It is preferred for X + to represent + NH 3 .
[0028] The substituted phenyl compounds having at least one alkenyl substituent that can be employed as water-soluble or water dispersible polymerizable surfactants in the practice of the subject invention include those disclosed in U.S. Pat. No. 5,332,854. The teachings of U.S. Pat. No. 5,332,854 are incorporated herein by reference for the purpose of disclosing polymerizable surfactants that can be used in the practice of this invention.
[0029] Suitable substituted phenyl compounds having at least one alkenyl substituent include compounds having the formula 4:
[0000]
[0000] wherein R 7 is an alkyl, alkenyl or aralkyl group containing 6 to 18 carbon atoms; R 8 is a hydrogen atom or an alkyl, alkenyl or aralkyl group containing 6 to 18 carbon atoms; R 9 is a hydrogen atom or a propenyl group; A is an unsubstituted or substituted alkylene group of 2 to 4 carbon atoms; n is an integer of 1 to about 200, preferably 2 to about 100; and M is an alkali metal, an ammonium ion or an alkanolamine residue.
[0030] In the substituted phenyl compounds of the invention, the alkyl, alkenyl and aralkyl groups of R 7 and R 8 are independently selected and may be the same or different. Suitable alkyl groups include, but are not limited to, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl. Suitable alkenyl groups include, but are not limited to, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl and octadecenyl. Suitable aralkyl groups include, but are not limited to, styryl, benzyl and cumyl.
[0031] The propenyl group may occur as trans- and cis-isomers. For the purposes of the present invention, these isomers may be used independently or as a mixture.
[0032] For A, suitable unsubstituted or substituted alkylene groups include, for example, ethylene, propylene, butylene, and isobutylene. The polyoxyalkylene group -(AO) n — can be a homopolymer, block polymer or random polymer, or a mixture thereof.
[0033] Substituted phenyl surfactants that can be used in the practice of this invention can be produced by adding an alkylene oxide such as ethylene oxide (EO) or propylene oxide (PO) to an alkylated propenyl phenol in the usual manner, sulfating the addict with a sulfating agent such as sulfuric acid, sulfamic acid, chlorosulfonic acid, or the like, followed by neutralizing with an alkaline substance.
[0034] A currently preferred group of substituted phenyl compounds are those compounds having the formula 5:
[0000]
[0000] wherein R 7 , A, M and n are as defined above. More preferred compounds are those wherein R 7 represents an alkyl, A is ethylene (—CH 2 CH 2 —), and M is alkali metal or ammonium. Most preferred compounds are those wherein M is ammonium, R 7 is nonyl, and n is about 10 to about 30.
[0035] The polyoxyalkylene-1-(allyloxymethyl) alkyl ether sulfate salts can be employed in making the polymers of this invention. Suitable polyoxyalkylene-1-(allyloxymethyl)alkyl ether sulfate salts include compounds having the formula 6:
[0000]
[0000] wherein R 10 is a linear or branched alkyl group containing 8 to 30 carbon atoms, preferably 8 to 14 carbon atoms, and more preferably 10 to 12 carbon atoms; R 11 is hydrogen or a methyl group, and is preferably hydrogen; A is an unsubstituted or substituted alkylene group having 2 to 4 carbon atoms; n is 0 or an integer of 1 to about 200, preferably 2 to about 100, more preferably 2 to about 30; and M is an alkali metal, an ammonium ion, or an alkanolamine residue. Examples of alkanolamine residues include monoethanolamine, triethanolamine, and the like.
[0036] For A, suitable unsubstituted or substituted alkylene groups include, for example, ethylene, propylene, butylene, and isobutylene. The polyoxyalkylene group -(AO) n — can be homopolymers, block polymers, random polymers, or a mixture thereof.
[0037] Preferred polyoxyalkylene-1-(allyloxymethyl) alkyl ether sulfate salts that can be used as the polymerizable surfactant in making the polymers of this invention are of the structural formula 7:
[0000]
[0000] wherein R 10 is an alkyl group containing 8 to 14 carbon atoms, and preferably 10 to 12 carbon atoms; n is an integer of 1 to about 200, preferably 2 to about 100, more preferably 2 to about 30; and M is an alkali metal, an ammonium ion, or an alkanolamine residue. More preferred compounds are those wherein R 10 is a decyl or dodecyl group, n is 5 to 10, and M is NH 4 , such as the compounds available from Dai-Ichi Kogyo Seiyaku Co., Ltd. (Tokyo, Japan) under the trademark Hitenol® KH.
[0038] A wide variety of carbonyl functionalized monomers can be utilized in making the polymers of this invention. These carbonyl functionalized monomers possess at least one aldo group or keto group and at least one polymerizable double bond. In other words these monomers are ketone functionalized or aldehyde functionalized ethylenically unsaturated compounds. The carbonyl functionalized monomer will typically contain only one carbon to carbon double bond because multiple carbon to carbon double bonds can lead to undesirably high levels of crosslinking in the polymer.
[0039] Some representative examples of carbonyl functionalized monomers that can be used in the practice of this invention include acrolein, diacetone acrylamide, (meth) acryloxyalkyl benzophenone, (meth)acrolein,crotonaldehyde, 2-butanone(meth)acrylate, fommystyrol, vinyl alkyl ketones containing from 4 to 7 carbon atoms (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl propyl ketone, and vinyl butyl ketone), diacetone acrylate, acetonyl acrylate, diacetone methacrylate, 2-hydroxypropyl acrylate acetylacetate, 1,4-butanediol acrylate acetylacetate, and (meth)acryloxyalkyl-propenals of the formula 8:
[0000]
[0000] wherein R 1 represents a hydrogen atom or a methyl group; R 2 represents a hydrogen atom or an alkyl group having from 1 to 3 carbon atoms; R 3 represents an alkyl group having from 1 to 3 carbon atoms; and R 4 represents an alkyl group having from 1 to 4 carbon atoms. These monomers may be used either individually or in combination with one or more additional carbonyl functionalized monomers. Preferred carbonyl functionalized monomers are diacetone acrylamide, acrolein, and vinyl methyl ketone. Diacetone acrylamide has the structural formula 9:
[0000]
[0000] and is commercially available from a variety of sources and is highly preferred from utilization as a monomer in making the polymers of this invention.
[0040] The phosphorous containing monomers used in making the polymers of this invention contain a polymerizable double bond and at least one phosphorous atom. The phosphorous containing monomer will preferably be a phosphate ester.
[0041] Suitable phosphate esters for use in the practice of the present invention include those represented by the formula 10:
[0000]
[0000] wherein R 1 represents a hydrogen atom or a methyl group, and wherein R 2 represents a hydrogen atom or a group of the structural formula 1.1:
[0000]
[0000] wherein R 1 again represents a hydrogen atom or a methyl group. A particularly useful phosphate ester for use in the present invention is hydroxylethyl methacrylate phosphate ester, which is sold under the trademark T-MULZ® 1228 and Sipomer PAM® 4000. The phosphorus containing monomer is different from the phosphate surfactant is that the phosphorus containing monomer has a much smaller hydrophilic group and thus typically is neither water soluble as a monomer nor as a portion of a polymer. The phosphorus containing monomer typically does not have the large poly(alkylene oxide) segments and/or sulfonated groups (strongly hydrophilic groups) of the phosphorus containing surfactant or the polymerizable surfactant. Thus, the phosphorus containing monomer has a different function than phosphate surfactant and/or polymerizable surfactant.
[0042] The ethylenically unsaturated monomer or monomers used in synthesizing the polymer of this invention is copolymerizable with the polymerizable surfactant, the carbonyl functionalized monomer and the phosphorous containing monomer utilized in making the polymer of this invention. The ethylenically unsaturated monomer or monomers will also, of course, be copolymerizable under the free radical emulsion polymerizations conditions utilized in synthesizing the polymer of this invention.
[0043] Examples of ethylenically unsaturated monomers that can be used in the process of the invention include mono vinyl aromatic monomers, alpha-beta ethylenically-unsaturated carboxylic acid ester monomers, unsaturated monomers with carboxylic acid groups, vinyl ester monomers, and various combinations of these. Preferably they are selected from the group consisting of esters of acrylic and methacrylic acid (e.g., those with 4 to 30 carbon atoms) such as n-butyl (meth)acrylate, methyl(meth)acrylate, ethyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, cycloalkyl(meth)acrylates, such as isobornyl(meth)acrylate and cyclohexyl(meth)acrylate, styrene, i.e., styrene or substituted styrenes, for instance alpha-methyl styrene or t-butyl styrene; vinyl toluene; dienes such as 1,3-butadiene or isoprene, and mixtures thereof. Also vinyl esters with 4 to 25 carbon atoms, such as vinyl acetate, vinyl alkanoate or their derivatives or mixtures thereof can be used in the monomer composition. Nitriles, such as (meth)acrylonitrile, or olefinically unsaturated halides, such as vinyl chloride, vinylidene chloride, and vinyl fluoride can also be used. Preferred vinyl ester monomers include vinyl esters of versatic acid such as the monomers commercialized by Hexion Specialty Chemicals under the trade names VEOVA® 9, 10 and 11.
[0044] Unsaturated monomers with acid (e.g., carboxylic acid) functionality, which include monomers of which the acid groups are latent as, for example, in maleic anhydride, are suitably selected from, but not limited to: acrylic acid, methacrylic acid, oligomerized acrylic acids such as beta-carboxyethyl acrylate or its higher analogues (commercially available from Rhodia as Sipomerm™ B-CEA), itaconic acid fumaric acid, maleic acid, citraconic acid, or the anhydrides thereof, styrene p-sulphonic acid, ethylmethacrylate-2-sulfonic acid and 2-acrylamido-2-methylpropane sulfonic acid. An acid bearing monomer could be polymerized as the free acid or as a salt, e.g., the NH 4 or alkali metal salts. Amide-functional comonomers include, but are not limited to, acrylamide- and methacrylamide. Another component optionally present is repeating units of mono or polycarboxylic acid groups (other than esters of said carboxylic acids). These unsaturated monomers with acid functionality are present in amounts less than 5 wt.% on average based on the weight of said and in another embodiment less than 3 wt. %, and still another embodiment less than 1 wt. % (e.g., acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric or maleic acid, etc.).
[0045] Another group of monomers which are useful in preparing the copolymers of the present invention are polar non-ionic monomers such as hydroxyalkyl (meth)acrylates, (meth)acrylamides and substituted (meth)acrylamides, N-vinyl-2-pyrrolidone, N-vinyl caprolactam, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (4-hydroxymethylcyclohexyl)-methyl (meth)acrylate, 1-(2-((2-hydroxy-3-(2-propenyloxy)propyl)amino)ethyl)-2-imidazolidinone, N-methylol (meth)acrylamide, Sipomer® WAM, WAM II (from Rhodia) and other urido-containing monomers, dimethylaminoethyl (meth)acrylate, and dimethylaminopropyl (meth)acrylamide. Mixtures of polar monomers also may be used. Those hydrophilic monomers should be used at appropriate levels, which do not impair the earlier water resistance.
[0046] Vinyl aromatic monomers can also be employed as the copolymerizable monomer. However, the total amount of vinyl aromatic monomers utilized in making the polymer of this invention will typically not exceed about 25 weight percent of the total weight of monomers employed in making the polymer in the case of polymers that are employed in exterior coatings. This is because polymers that contain more than about 25 weight percent vinyl aromatic monomers are prone to yellowing and chalking on exposure to ultraviolet light. It is generally preferred for polymers that are employed in exterior coating applications to contain less than 10 or 20 weight percent vinyl aromatic monomer.
[0047] The polymerizable surfactant will be incorporated into the polymers of this invention at a level which is within the range of 0.05 weight percent to 5 or 8 weight percent, based upon the total weight of the polymer. The polymerizable surfactant will more typically be incorporated into the polymers of this invention at a level which is within the range of 0.1 weight percent to 5 weight percent and will preferable be incorporated into the polymers of this invention at a level which is within the range of 0.2, 0.3 or 0.5 weight percent to 2 weight percent.
[0048] The carbonyl functionalized monomer will be incorporated into the polymers of this invention at a level which is within the range of 0.5 weight percent to 15 or 20 weight percent, based upon the total weight of the polymer. The carbonyl functionalized monomer will more typically be incorporated into the polymers of this invention at a level which is within the range of 2 weight percent to 12 weight percent and will preferable be incorporated into the polymers of this invention at a level which is within the range of 2 weight percent to 8 weight percent.
[0049] The phosphorous containing monomer will be incorporated into the polymers of this invention at a level which is within the range of 0.1 weight percent to 10 weight percent, based upon the total weight of the polymer. The phosphorous containing monomer will more typically be incorporated into the polymers of this invention at a level which is within the range of 0.2 or 0.3 weight percent to 5 weight percent and will preferable be incorporated into the polymers of this invention at a level which is within the range of 0.2 or 0.5 weight percent to 2.5 weight percent.
[0050] In addition to the polymerizable surfactant, the carbonyl functionalized monomer, and the phosphorous containing monomer the balance of the polymers of this invention will be comprised of the ethylenically unsaturated polymerizable monomers. Thus, in one embodiment, the emulsion polymer(s) of this invention will contain at least 38 weight percent of the additional ethylenically monomers. More specifically, the emulsion polymer will be comprised of 0.05 to 5 or 8 weight percent of the polymerizable surfactant, 0.5 weight percent to 15 or 20 weight percent of the carbonyl functionalized monomer, 0.1, 0.5, or 2 to 8, 10, 12 or 15 weight percent of the phosphorous containing monomer, and about 30, 38 or 70 to 98.8, 98.9, or 99.35 weight percent of at least one ethylenically unsaturated monomer.
[0051] In many cases, it is advantageous to utilize both an alkyl acrylate monomer and an alkyl methacrylate monomer is making the polymers of this invention. For instance, in one embodiment, the polymer can advantageously be comprised of about 20, 30, or 40 to 80 weight percent of a alkyl methacrylate monomer, 15 to 30, 40 or 50 weight percent of an alkyl acrylate monomer, 4 weight percent to 8 weight percent of a carbonyl functionalized monomer, 1 weight percent to 3 weight percent of a phosphorous containing monomer, and 0.2 weight percent to 1 weight percent of a polymerizable surfactant. In one embodiment, the alkyl acrylate monomer can be methyl methacrylate, the alkyl acrylate monomer can be 2-ethyl hexyl acrylate, the carbonyl functionalized monomer can be diacetone acrylamide, and the phosphorous containing monomer can be hydroxy ethyl methacrylate phosphate ester. Alternative ranges and monomers can be used in alternative embodiments. It is frequently desirable to include a small amount of methacrylic acid in polymers of this type. For example, it may be desirable to include from about 0.1 weight percent to about 5 weight percent methacrylic acid or other carboxylic acid containing ethylenically unsaturated monomers in polymers of this type. It is typically more desirable to include from about 0.2 weight percent to about 1 weight percent carboxylic acid containing ethylenically unsaturated monomers in polymers of this type.
[0052] Beside surfactants described above, other surfactants also may be used as co-surfactants in emulsion polymerization. These co-surfactants include anionic or nonionic emulsifiers and mixtures thereof. Typical anionic emulsifiers include alkali or ammonium alkyl sulfates, alkyl sulfonates, salts of fatty acids, esters of sulfosuccinic acid salts, alkyl diphenylether disulfonates, and the like, and mixtures thereof. Typical nonionic emulsifiers include polyethers, e.g., ethylene oxide and propylene oxide condensates, including straight and branched chain alkyl and alkylaryl polyethylene glycol and polypropylene glycol ethers and thioethers, alkyl phenoxypoly(ethyleneoxy)ethanols having alkyl groups containing from about 7 to about 18 carbon atoms and having from about 4 to about 100 ethyleneoxy units, and polyoxy-alkylene derivatives of hexitol, including sorbitans, sorbides, mannitans, and mannides; and the like, and mixtures thereof. Co-surfactants typically are employed in the compositions of the present invention at levels of about 0 wt. % to about 3 wt. % High concentration of co-surfactant may adversely affect early water bushing or whitening resistance.
[0053] The emulsion polymerization employed in synthesizing the polymer of this invention is carried out in a conventional manner using well-known additives and ingredients; such as emulsifiers, free radical polymerization initiators, and the like, and mixtures thereof. Either thermal or redox initiation processes may be used. The reaction temperature typically is maintained at a temperature lower than about 100° C. throughout the course of the reaction. In one embodiment, a reaction temperature between about 50° C. and 95° C. is used.
[0054] For the purpose of adjusting pH at the outset of the polymerization pH control agents and buffers typically are added. The initial reactor pH will normally be within the range of about 3 to about 10. However, other pH values may be obtained in particular applications using pH control agents and buffers well known to those skilled in the art. Non-limiting examples of suitable pH control agents include but are not limited to ammonium and alkali metal hydroxides (such as sodium hydroxide and potassium hydroxide), and mixtures thereof, and the like. Non-limiting examples of suitable buffers include ammonium carbonate, sodium carbonate, sodium bicarbonate, and mixtures thereof, and the like. pH may be adjusted if desired at the end of the polymerization process according to the desired application.
[0055] In preparing the copolymer component, any chain-transfer agent, or mixtures thereof, may be used to control molecular weight. Suitable chain transfer agents include, for example, C 1 to C 1-2 alkyl or functional alkyl mercaptans, alkyl or functional alkyl mercaptoalkanoates, or halogenated hydrocarbons, and the like, and mixtures thereof. Chain transfer agents typically are employed at levels of about 0.1 weight percent to about 10 weight percent, based on total monomer weight.
[0056] The copolymers typically are prepared in the presence of water-soluble or oil-soluble initiators (such as persulfates, peroxides, hydroperoxides, percarbonates, peracetates, perbenzoates, azo-functional compounds, and other free-radical generating species, and the like, and mixtures thereof, as is well known to those skilled in the art.
[0057] Any nitrogen-containing compound having at least two amine nitrogens reactive with carbonyl groups may be employed as a crosslinking agent in the practice of the present invention. The crosslinker may be added during the polymerization process or post-added during formulation of the coating compositions. Such crosslinking agents may be aliphatic or aromatic, polymeric or non-polyineric, and may be used alone or in combination. Non-limiting examples of suitable compounds include: hydrazine, aliphatic dihydrazines having from 2 to 4 carbon atoms such as but not limited to ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, and butylene-1,4-dihydrazine, alkylene dioxime ethers, and water soluble dihydrazides of dicarboxylic acids (for example, dihydrizides of malonic, succinic, and adipic acids). In one embodiment, the dihydrazide of adipic acid (adipic acid dihydrazide) is used.
[0058] In one embodiment, the crosslinking agent is used in an amount sufficient to react with about 0.25 to about 1 carbonyl mole equivalents present in the copolymer. In another embodiment, the crosslinking agent is used in an amount sufficient to react with at least about 0.5 to about 1 carbonyl mole equivalents (derived from the carbonyl functional monomer) present in the copolymer.
[0059] In this invention, the glass transition temperature (“Tg”) of the emulsion copolymer should be maintained below about 90° C. Tg's used herein are those calculated by using the Fox equation; see T. G. Fox, Bull. Am. Physics Soc., Volume 1, Issue No. 3, page 123, (1956). In other words, for calculating the Tg of a copolymer of monomers M1 and M2, 1/Tg(calc.)=w(M1)/Tg(M1)+w(M2)/Tg(M2), wherein Tg(calc.) is the glass transition temperature calculated for the copolymer, w(M1) is the weight fraction of monomer M1 in the copolymer, w(M2) is the weight fraction of monomer M2 in the copolymer, Tg(M1) is the glass transition temperature of the homopolymer of M1, and Tg(M2) is the glass transition temperature of the homopolymer of M2, with all temperatures being in ° K. Glass transition temperatures of homopolymers may be found, for example, in J. Brandrup and E. H. Immergut, ed., Polymer Handbook, Interscience Publishers.
[0060] When the emulsion polymers were made by various processes to create core-shell or non-uniform monomer distribution in the particles or multi-modal particle distribution or other morphology, the Tg calculation is based on the total monomers used in the polymerization, regardless of the sequence of monomer additions.
[0061] The latex formed by the free radical emulsion polymerization can optionally be diluted with additional water to any concentration (solids content) that is desired. This latex can then be used in the preparation of water based coatings-employing techniques that are well-known to those skilled in the art.
[0062] Desired pigments, plasticizers, coalescing solvents, fillers, wetting agents, stabilizers, defoamers, dryers, antibacterial agents, fungicides, insecticides, antifouling agents, and anticorrosive agents can be mixed directly into the latex.
[0063] Pigments are normally added to paint formulations to impart color and hiding to the coating. Titanium dioxide is an example of a widely used pigment which imparts hiding and a white color. Mineral pigments (such as oxides of iron and chromium), organic pigments (such as phthalocyanine) and active anticorrosive pigments (such as zinc phosphate) are representative examples of other widely used pigments.
[0064] The fillers employed in making water based coating formulations are normally inexpensive materials which are added to attain the desired consistency and non-settling characteristics. Fillers can also improve a coating's physical properties, such as resistance to cracking and abrasion. Some representative examples of widely utilized fillers include chalks, clays, micas, barites, talcs, and silica.
[0065] Fungicides and algaecides are commonly added to interior and exterior house paints and are of particular value in coating formulations that will be used in warm climates. Antifouling compounds are commonly added to marine-paints to inhibit marine growth.
[0066] A film-forming, water based composition can be prepared utilizing a mixture of the polymer with suitable coalescing solvent and plasticizer. It is preferred for the coalescing solvent to be at least water inmiscible and even more preferably for it to be water insoluble. Of the various solvents which can be used, generally ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether are preferred. It should be noted that the solvent and plasticizer can be mixed directly with the polymer in its water emulsion. In one embodiment, the coalescing solvent (aid) is present in an amount from about 2 to about 20 weight percent based on the total weight of the polymer. In another embodiment, it is present from about 3 to about 15 weight percent.
[0067] A wide variety of plasticizers can be used in the practice of this invention. They can, for example, be of the type listed in the Federation Series on Coatings Technology, Unit Twenty-two, entitled “Plasticizers,” published April, 1974, so long as they fulfill the melting point, boiling point and compatibility requirements. Some representative examples of plasticizers that can be used include propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, propylene glycol diacetate, dipropylene glycol dimethyl ether, diethylene glycol ethyl ether, diethylene glycol methyl ether, diethylene glycol n-butyl ether, diethylene glycol hexyl ether, diethylene glycol n-butyl ether acetate, ethylene glycol propyl ether, ethylene glycol n-butyl ether, ethylene glycol hexyl ether, ethylene glycol n-butyl ether acetate, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol n-butyl ether, ethylene glycol phenyl ether, ethylene glycol n-butyl ether mixture, polyethylene glycol dibenzoate, o-p-toluene sulfonamide, trimethylpentanediol dibenzoate and trimethylpentanediol monoisobutyrate monobenzoate.
[0068] In making a water based coating compositions of this invention, typically about 25 parts by weight to about 100 parts by weight of the polymer is incorporated into 100 parts by weight of water. However, more or less water can usually be employed. Level of polymer utilized will also depend upon the type and amount of coalescing solvent and plasticizer used. The water based coating composition, as an aqueous dispersion or solution, can then be applied as a coating onto a suitable substrate such as wood, masonry, plastic or metals. As has been explained, the water based coating compositions of this invention are a particular value for application to masonry surfaces, such as garage floors and concrete driveways.
[0069] This invention is illustrated by the following examples that are merely for the purpose of illustration and are not to be regarded as limiting the scope of the invention or the manner in which it can be practiced. Unless specifically indicated otherwise, parts and percentages are given by weight.
Example 1
[0070] An emulsion polymer of methacrylic acid, methyl methacrylate, 2-ethylhexyl acrylate, diacetone acrylamide and T-mulz1228 phosphate monomer was made by using Polystep® NMS-9 (a polymerizable phosphate surfactant). A monomer premix was made by mixing 216 grams of water, 45.6 grams of diacetone acrylamide, 0.8 grams of ammonium carbonate, 19.2 grams of Polystep® NMS-9, 4.57 grams of ammonium hydroxide, 13.6 grams of T-Mulz 1228 with 16 grams of water flush, 4 grams of methacrylic acid, 280 grams of methyl methacrylate, 280 grams of 2-ethylhexyl acrylate. Initiator A was made by dissolving 0.8 grams of ammonium persulfate in 13.3 grams of water. Initiator B was made by dissolving 1.2 grams of ammonium, persulfate in 80 grams of water. A 3-liter reaction vessel was charged as follows: 568 grams of water, 0.72 grams of ammonium carbonate, and 6.86 grams of Calfax® 16-L35 grams, and then was heated to 88° C. under nitrogen. Initiator A was then added to the reaction vessel, followed by proportioning the monomer premix to the reaction vessel over a period of about 3 hours. At 45 minutes after premix proportioning started, initiator B was proportioned into the reaction vessel over a period of about 3 hours and 30 minutes. At 75 minutes after premix proportioning started, the premix proportioning was stopped for 15 minutes. 176 grams of methyl methacrylate was added the remaining monomer premix and 6.86 grams of Calfax® 16 L-35 was added into the reactor. After completion of initiator B feed, the temperature of the reaction vessel was maintained at 88° C. for 30 minutes. The reaction vessel then was cooled to 57° C. A mixture of 10.64 grams of water, 0.91 grams of t-butyl hydroperoxide, and 0.27 grams of 30% ammonium lauryl was added to the reaction vessel. After about 5 minutes, 23.2 grams of 2.4% erythorbic acid was added to the reaction vessel. After 30 minutes, the reaction vessel was cooled to room temperature and filtered through 100-micron cloth. Then, 128 grams of 12.8% adipic acid dihydrazide, ammonium hydroxide, and biocide were added. The product had a pH about 8.5.
Example 2
[0071] The emulsion polymer was made exactly the same as Example 1 except that 240.8 grams of methyl methacrylate and 256 grams of 2-ethylhexyl acrylate were used in the monomer premix, 240 grams of methyl methacrylate was added in the remaining monomer premix, and 6.86 grams of Calfax® 16 L-35 was added into the reactor at 75 minute stop. All, other monomers were the same.
Example 3
[0072] The emulsion polymer was made exactly same as Example 2 except 4.8 grains of Dextrol™ OC-70 phosphate ester of tridecyl alcohol ethoxylate was used instead of Polystep® NMS-9.
Example 4
[0073] The emulsion polymer was made exactly same as Example 1 except that 13.6 grams of Sipomer™ PAM-4000 phosphate monomer (instead of T-mulz 1228 monomer), 224.8 grams of methyl methacrylate and 272 grams of 2-ethylhexyl acrylate were used in the monomer premix. All other monomers were the same.
Example 5
[0074] An emulsion polymer of metliacrylic acid, methyl methacrylate, 2-ethylhexyl acrylate, styrene, diacetone acrylamide and Sipomemm PAM-4000 phosphate monomer was made by using Polystep® NMS-9 polymerizable phosphate surfactant. A monomer premix was made by mixing 432 grams of water, 91.2 grams of diacetone acrylamide, 2.4 grams of ammonium carbonate, 38.4 grams of Polystep® NMS-9, 27.2 grams of Sipomer™ PAM-4000 with 32 grams of water flush, 9.14 grams of ammonium-hydroxide, 8 grams of methacrylic acid, 81.6 grams of methyl methacrylate, 400 grams of styrene, 5.12 grams of 2-ethylhexyl acrylate. Initiator A was made by dissolving 2.24 grams of ammonium persulfate in 26.6 grams of water. Initiator B was made by dissolving 2.4 grams of ammonium persulfate in 160 grams of water. A 5-liter reaction vessel was charged as follows: 1136 grams of water, 1.44 grams of ammonium carbonate, and 9.14 grams of Calfax® 16-L35 grams, and then was heated to 84° C. under nitrogen. Initiator A was then added to the reaction vessel, followed by proportioning the monomer premix to the reaction vessel over a period of about 3 hours. The reaction was kept at 88° C. At 45 minutes after premix proportioning started, initiator B was proportioned into the reaction vessel over a period of about 3 hours and 30 minutes. At 70 minutes after premix proportioning was started, the premix proportioning was stopped for 15 minutes. Then, 480 grams of methyl methacrylate was added the remaining monomer premix and 13.71 grams of Calfax® 16 L-35 was added into the reactor. After completion of initiator B feed, the temperature of the reaction vessel was maintained at 88° C. for 30 minutes. The reaction vessel then was cooled to 57° C. A mixture of 21.28 grams of water, 1.83 grams of t-butyl hydroperoxide, and 0.53 grams of 30% ammonium lauryl was added to the reaction vessel. After about 5 minutes, 46.4 grams of 2.4% erythorbic acid was added to the reaction vessel. After 30 minutes, the reaction vessel was cooled to room temperature and filtered through 100-micron cloth. Then, 256 grams of 12.8% adipic acid dihydrazide, ammonium hydroxide, and biocide were added. The product had a pH about 8.5.
Example 6
[0075] In this experiment, the emulsion polymer was made utilizing the same procedure as in Example 2 except Polystep® NMS-9 was replaced by 4.8 grams of Adeka™ SR-10 polymerizable surfactant.
Example 7
[0076] In this experiment, the emulsion polymer was made using the same procedure as in Example 2 except that the Polystep® NMS-9 was replaced by 4.8 grams of Hetenol™ KH-10 polymerizable surfactant.
Comparative Example 1
[0077] In this experiment, the emulsion polymer was made using exactly same procedure as were employed in Example 2 except that the T-multz was replaced with methacrylic acid.
Comparative Example 2
[0078] In this experiment, the emulsion polymer was made utilizing the same procedure as in Example 2 except that T-multz was replaced by AMPS™ 2405 monomer at same solids basis.
Comparative Example 3
[0079] In this comparative experiment, an emulsion polymer was synthesized using the same procedure that was employed in Example 2 except that Polystep® NMS-9 was replaced by Disponil™ AES-25 nonyl phenol ethoxylated sulfate at same solids basis.
Comparative Example 4
[0080] In this experiment, an emulsion polymer was made by the same technique that was utilized in Example 2 except that Polystepg NMS-9 was replaced by 6.86 grams of Calfax® 16L-35 and 8 grams of sodiuin laureth sulfate.
Comparative Example 5
[0081] In this experiment, an emulsion polymer was made using the same procedure that was employed in Example 2 except that Polystep® NMS-9 was replaced by 686 grams of Calfax® 16L-35 and 3.43 grams of Aerosol™ TR-70.
Comparative Example 6
[0082] In this experiment, an emulsion polymer was synthesized by the same technique that was use in Example 2 except that Polystep® NMS-9 was replaced by 8 grams of Rhoplex™ ES-30 sodium trideceth sulfate.
[0083] The data from Examples 1-7 and Comparative Examples 1-6 is summarized below in Table 0.1. In Comparative Examples 1 and 2, no phosphate monomer was incorporated into the polymer. In Comparative Examples 3-6, no polymerizable monomer or phosphate surfactant was incorporated into the polymer.
[0000]
TABLE 1
Experimental Polymers Formulated in
Clear Coatings Comparative Study
Brake
Early
Fluid
Blush
Resis-
% of
Additive 1
Additive 2
Resistance
tance
Total
Example #
Example 1
NMS-9
T-mulz 1228
10
8
90
Example 2
NMS-9
T-mulz 1228
10
8
90
Example 3
OC-70
T-mulz 1228
10
8
90
Example 4
NMS-9
PAM-4000
10
8
90
Example 5
NMS-9
PAM-4000
10
9
95
Example 6
Adeka ™ SR-
T-mulz 1228
6
8
70
10
Example 7
Hetenol ™
T-mulz 1228
10
8
90
KH-10
Comparative
Example #1
NMS-9
MAA
0
0
0
Example #2
NMS-9
AMPS-2405
6
0
30
Example #3
Disponil ™
T-mulz 1228
10
0
50
AES-25
Example #4
Calfax ™ &
T-mulz 1228
0
6
30
ALS
Example #5
Calfax ™ &
T-mulz 1228
6
6
60
TR-70
Note:
Early blush resistance was reported on a 0-10 scale where 10 is excellent and 0 is indicative of total failure. Brake fluid resistance is also reported on a 0-10 scale where 10 is excellent and 0 is indicative of total failure.
[0084] As can be seen by reviewing the data in Table 1, the experimental polymers made in accordance with this invention offered generally better early blush resistance and resistance to brake fluid than did the polymers made in the Comparative Examples using conventional technology.
Paint Examples
[0085] In this series of experiments, the latex of the polymer synthesized in Example 2 and a number of commercially available lattices were formulated into clear waterborne coating compositions for application to horizontal masonry substrates. The coatings made with these formulations were evaluated for early water resistance, blushing on concrete, adhesion, and chemical resistance. These characteristics were evaluated utilizing the following test procedures:
1) Early Water Resistance
[0000]
Apply 1 coat on black Leneta scrub chart; dry at room temperature for 2 hours.
Immerse ½ of the chart in a water bath for 24 hours.
Remove chart from water batch and rate for degree of blushing, blistering and other film deformation after removing from water immediately and after 24 hour recovery at room temperature.
Rating scale is 1-10 (10 is best).
2) Blushing on Concrete
[0000]
Apply 2 coats on Type 1 smooth concrete; dry film for 24 hours at room temperature.
Apply a cotton (absorbent) pad to the surface of the coated concrete.
Soak the cotton pad with water. Leave wet cotton pad on the coated concrete for 24 hours.
Remove the cotton pad, rate for degree of blushing and recovery immediately after removing the cotton pad and after recovery for 24 hours.
Rating scale is 1-10 (10 is best).
3) Adhesion
[0000]
Apply 1 or 2 coats on Type 1, smooth concrete; dry at room temperature for 24 hours.
Using a cross-hatch template and very sharp utility knife, cut through the film in a 10×10 grid pattern.
Firmly apply Permacel™ tape to the grid area; then remove tape in a quick motion at 90° from the surface.
To a second 10×10 grid, apply a cotton pad and completely saturate with water.
Remove cotton pad after 30 minutes.
Gently pat the wet area to dry it off; after 5 minutes, apply the Tm tape and repeat tape pull as noted above.
Rate the following rating scale is 0-5 (5 is Excellent, no film removed).
4) Chemical Resistance
[0000]
Apply 2 coats on Type 1, smooth concrete, dry for 3 days at room temperature.
Place a cotton pad on the surface; saturate with one of the following products; dirty motor oil, brake fluid, windshield washing fluid, transmission fluid, Skydrol™, antifreeze, bleach, pool chlorine, TSP and other similar materials.
Allow the wet pad to come in direct contact with the film surface for 1 hour.
Remove wet pad and rate for degree of film defect.
Rating scale is 1-10 (10=Excellent)
[0107] The coating compositions made in this series of experiments were formulated utilizing the ingredients identified in Table 2. In making these coating formulations, the ingredients identified in Table 2 were added to a mixing vessel sequentially in the order listed under continuous agitation. Ammonia was added immediately after the addition of the polymer latex in a quantity which was sufficient to adjust the pH of the formulation to 9.
[0000]
TABLE 2
Clear - Horizontal Masonry Coating 100 g/l VOC
Weight %
Water
36.7
Surfynol ® 104H surfactant 1
0.9
BYK ® 333 polyether modified
0.1
polydimethylsiloxane
Dowanol ® DPnB dipropylene glycol
2.7
monobutyl ether
Polymer emulsion
59.1
Ammonia (pH = 9)
0.1
Acrysol ® RM 825 polyurethane
0.4
associative thickener
Total
100
1 Surfynol ® 104H surfactant is a mixture containing 75 weight percent of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (CAS Number 126-86-3) and 25 weight percent of ethylene glycol.
[0108] The identity of the polymer latex utilized in making each of the formulations in this series of experiments is identified in the following tables as are the physical and chemical characteristics of the coatings made.
[0000]
TABLE 3
Experimental
Commercial Polymers for
Polymer
Masonry or Concrete
from
Poly-
Poly-
Poly-
Poly-
Example 2
mer 1
mer 2
mer 3
mer 4
Early Blush Resistance
(10 = Excellent)
Blush
10
0
5
0
5
Recovery
10
5
0
0
10
Adhesion
(10 = excellent)
Dry Tape Pull
10
10
10
8
10
Chemical Resistance
(10 = Excellent)
Dirty Motor
10
9
9
9
9
Oil
Brake Fluid
9
0
0
6
9
Winshield
10
8
8
10
10
Washer Fluid
TSP
10
9
10
10
5
Skydrol ™
10
5
5
6
6
Ethylene
10
8
10
10
6
Glycol
Overall
89
54
57
59
70
Rating
[0000]
TABLE 4
Paint from
Commercial Paints for Masonry or Concrete
Polymer of
Paint
Paint
Paint
Paint
Paint
Paint
Example 2
A
B
C
D
E
F
Early Blush Resistance
(10 = Excellent)
Blushing
10
2
8
10
0
2
1
Recovery
10
2
10
10
0
2
1
Adhesion
(10 = Excellent)
Dry Tape Pull
10
10
10
10
2
8
6
Chemical Resistance
(10 = Excellent)
Dirty Motor Oil
10
9
8
8
9
10
10
Brake Fluid
9
1
0
0
0
1
0
Winshield Washer
10
9
9
8
9
10
8
Fluid
TSP
10
5
9
10
10
10
0
Skydrol ™
10
1
0
0
0
1
0
Ethylene Glycol
10
10
10
10
10
10
9
Overall Rating
89
49
64
66
40
54
35
[0109] As can be seen from the Tables above, the experimental latex of this invention provided coating formulations that had a unique combination of early blush resistance as well as excellent resistance to household chemicals. These coating compositions also exhibited outstanding adhesion characteristics to masonry substrates. Accordingly, these coating formulations offer an excellent combination of characteristics for application to horizontal concrete substrates.
[0110] While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. | This invention relates to waterborne coatings with enhanced early water blushing resistance, chemical resistance, and adhesion to substrates. These waterborne coatings can be paints, varnishes, and water sealers that offer excellent early water blushing as well as. excellent resistance to common household chemicals, such as gasoline, motor oil, brake fluid, transmission fluid, household cleaners, window cleaning fluids, antifreeze, and the like. | 2 |
FIELD OF THE INVENTION
[0001] The present invention generally relates to air conditioning systems and, more particularly, to an electrically driven air conditioning system for an aircraft that does not rely on engine bleed air.
BACKGROUND OF THE INVENTION
[0002] Many air conditioning systems employed in modern commercial aircraft utilize the air-to-air thermodynamic cycle to provide cooling and/or heating air to the various compartments on the aircraft, such as the passenger cabin, cargo holds, and the like. Air from the compressor stages of the main jet propulsion engines, also known as “bleed air,” is generally output at high temperature and pressure (i.e. 610 OF and 60 psi). Conventionally, this bleed air is then conditioned through conditioning packs before passing into the pressurized fuselage for cabin temperature control, ventilation, and pressurization. This conditioned air within the fuselage is then discharged to the outside ambient air through various overboard valves, overflow valves, and cabin leaks.
[0003] This known method of conditioning air for use with the various aircraft systems is inefficient. That is, during a typical steady state cruise operation, more energy than is necessary for the primary requirements of the conditioning system (e.g. cabin temperature control, ventilation, and pressurization) is added into the conditioning system at the engines in the form of additional fuel. Much of this excess energy is wasted in the form of heat and pressure drop through ductwork, valves, and various other components of the conditioning system. Moreover, extracting work from the engines in the form of bleed air is inefficient relative to other extraction methods. Consequently, the use of bleed air from the engines reduces the efficiency of the engines and, thus, increases the fuel consumption and load on the engines. By eliminating or at least minimizing the use of bleed air in the various aircraft systems, it is believed that more efficient jet engines may be developed. Moreover, it is believed that alternative air conditioning systems may lead to a reduction in aircraft weight, assembly complexity, and fuel consumption.
[0004] Accordingly, there exists a need in the relevant art to provide an air conditioning system for an aircraft that does not rely on jet engine bleed air for operation. Furthermore, there exists a need in the relevant art to provide an air conditioning system for an aircraft that is capable of reducing the aircraft weight, assembly complexity, and fuel consumption. Still further, there exists a need in the relevant art to provide an air conditioning system for an aircraft driven by electrical energy. Moreover, there exists a need in the relevant art to provide an air conditioning system for an aircraft that overcomes the disadvantages of the prior art.
SUMMARY OF THE INVENTION
[0005] An all electric air conditioning system for an aircraft, wherein the aircraft defines an interior volume having conditioned air at a first pressure, is provided having an advantageous construction. A compressor is provided and is operable to compress supply air to a second pressure. The compressor being operated in response to an electrical drive motor. A passage fluidly couples the compressor and the interior volume of the aircraft. A heat-dissipating device, such as a heat exchanger, is positioned in the passage to extract heat energy from the supply air. This arrangement permits conditioning of air within the aircraft without using bleed air from the engines. The use of bleed air results in a significant amount of fuel burn. An optional conditioned air recovery system may be coupled to the interior volume of the fuselage to direct at least a portion of the conditioned air from the interior volume back for further conditioning and use.
[0006] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0008] [0008]FIG. 1 is a circuit diagram illustrating a first embodiment of the present invention in a ground or low altitude operation configuration;
[0009] [0009]FIG. 2 is a circuit diagram illustrating the first embodiment of the present invention in a cruise operation configuration;
[0010] [0010]FIG. 3 is a circuit diagram illustrating a second embodiment of the present invention in a ground or low altitude operation configuration;
[0011] [0011]FIG. 4 is a circuit diagram illustrating the second embodiment of the present invention in a cruise operation configuration;
[0012] [0012]FIG. 5 is a circuit diagram illustrating a third embodiment of the present invention in a ground or low altitude operation configuration;
[0013] [0013]FIG. 6 is a circuit diagram illustrating the third embodiment of the present invention in a cruise operation configuration; and
[0014] [0014]FIG. 7 is a circuit diagram illustrating various alternative modifications of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. That is, the electrical air conditioning system of the present invention may find utility in other applications, which commonly use bleed air to drive an air conditioning system, such as in tanks and the like.
[0016] According to a first embodiment of the present invention, an air conditioning system 10 is illustrated that is capable of eliminating the use of bleed air. Air conditioning system 10 comprises a first compressor 12 , a second compressor 14 , a first turbine 16 , a second turbine 18 , a heat exchanger assembly 20 , a reheater 22 , a condenser 24 , and a high-pressure water separator 26 . With particular reference to FIG. 1, a ram air fan 28 provides cold side air for heat exchanger assembly 20 during ground operation. With particular reference to FIG. 2, a ram air inlet scoop (not shown) provides cold side air for heat exchanger assembly 20 during in-flight operation. Ram air, generally indicated as 100 , is provided to first compressor 12 via a passage 30 and further to heat exchanger assembly 20 . A valve 62 controls the amount of ram air 100 that is directed to heat exchanger assembly 20 . Alternatively, engine fan air could be used to provide cool side air to first compressor 12 in place of ram air 100 .
[0017] First compressor 12 is fluidly coupled to a primary heat exchanger 32 of heat exchanger assembly 20 via a passage 34 . Primary heat exchanger 32 in turn is fluidly coupled to second compressor 14 via a passage 36 . Second compressor 14 in turn is fluidly coupled to a secondary heat exchanger 38 via a passage 40 . Secondary heat exchanger 38 is fluidly separate from primary heat exchanger 32 . Hence, it should be understood that primary heat exchanger 32 and secondary heat exchanger 38 might be configured as separate units or a single unit having multiple discrete chambers.
[0018] A compressor bypass valve 42 may fluidly interconnect passage 36 and passage 40 so as to permit bypassing of second compressor 14 . Furthermore, an ozone converter 44 may be positioned in series within passage 40 to permit proper conversion of ambient air during a cruise phase of flight.
[0019] As seen in FIGS. 1 and 2, heat exchanger assembly 20 also employs ram air 100 acting as a heat sink to remove excess heat from the air upon exit from first compressor 12 and again upon exit from second compressor 14 . Trim air 46 may be extracted from passage 40 for use in individual compartment temperature control or for use in other aircraft systems.
[0020] Secondary heat exchanger 38 is fluidly coupled to reheater 22 via a passage 48 . The cold outlet of reheater 22 is directed to first turbine 16 through a passage 50 so as to be expanded and reduced in temperature therein. This air is then directed into the cold inlet of condenser 24 via a passage 52 . It should be appreciated that the cold inlet side of condenser 24 is maintained above freezing to prevent ice formation. The air from condenser 24 is then directed to second turbine 18 via a passage 54 for final expansion. Finally, air exits second turbine 18 via passage 56 and is directed to a mix manifold (not shown) for distribution into the aircraft cabin.
[0021] Still referring to FIGS. 1 and 2, air conditioning system 10 further includes a passage 58 fluidly interconnecting condenser 24 to water collector 26 and a passage 60 fluidly interconnecting water collector 26 to reheater 22 . A passage 61 is further provided that fluidly interconnects reheater 22 and condenser 24 . Air conditioning system 10 still further includes a ram air modulator valve/actuator 62 used for controlling the flow of ram air 100 . A turbine bypass valve 64 fluidly interconnects passage 54 and passage 56 so as to permit bypassing of second turbine 18 . A first motor 66 is operably coupled between first compressor 12 and second turbine 18 and a second motor 68 is operably coupled between second compressor 14 and first turbine 16 .
[0022] With particular reference to FIG. 2, it can be seen that air conditioning system 10 further includes an altitude valve 70 fluidly interconnecting passage 48 and passage 54 . Altitude valve 70 permits bypassing of a condensing loop 72 above a predetermined altitude. Condensing loop 72 generally includes reheater 22 , passage 50 , first turbine 16 , passage 52 , condenser 24 , passage 58 , water collector 26 , passage 60 , and passage 61 . The opening of altitude valve 70 bypasses condensing loop 72 such that primary cooling of the air occurs in heat exchanger assembly 20 and second turbine 18 . This arrangement at altitude enables the overall pressure drop in the system to be minimized so as to provide sufficient flow to the passenger cabin at lower power consumption levels.
[0023] Referring to FIGS. 1 and 2, during operation, first compressor 12 receives ambient air 100 from ram air fan 28 . This air is compressed within first compressor 12 and is passed through primary heat exchanger 32 of heat exchanger assembly 20 to second compressor 14 . Primary heat exchanger 32 removes heat from the air using ram air 100 as a heat sink. The air is then compressed within second compressor 14 and passed through secondary heat exchanger 38 of heat exchanger assembly 20 . Second compressor 14 may be bypassed using compressor bypass valve 42 .
[0024] During ground or low altitude operation, air then exits secondary heat exchanger 38 and is directed to reheater 22 . The cold outlet of reheater 22 directs air to first turbine 16 where the temperature and pressure are reduced. The air is then directed to condenser 24 to remove excess water from the air. The cold outlet of condenser 24 directs the air to second turbine 18 where the temperature and pressure are further reduced. Lastly, the air is then directed to the mixing manifold and distributed to the aircraft cabin.
[0025] Air and water from condenser 24 flows to water collector 26 through passage 58 , where water is collected by water collector 26 .
[0026] During high altitude operation, air from secondary heat exchanger 38 of heat exchanger assembly 20 is directed through altitude valve 70 so as to completely bypass condensing loop 72 . Accordingly, air flows from secondary heat exchanger 38 directly to second turbine 18 so as to minimize the pressure drop within system 10 during high altitude cruise. Therefore, power consumption is minimized.
[0027] According to a second embodiment of the present invention, an air conditioning system 10 ′ is illustrated that is capable of eliminating the use of bleed air and further capable of utilizing the potential energy of pressurized air leaving the aircraft cabin during high altitude flight.
[0028] With particular reference to FIGS. 3 and 4, in addition to those elements described in reference to FIGS. 1 and 2, air conditioning system 10 ′ further includes an outflow turbine 110 . Outflow turbine 110 is illustrated as being operably coupled to motor 68 and first turbine 16 . However, it must be understood that outflow turbine 110 may be alternatively coupled to first compressor 12 or second turbine 18 . Outflow turbine 110 receives previously conditioned air from the cabin of the aircraft through a cabin recovery valve 112 . Cabin recovery valve 112 is actuated to provide flow of conditioned air through outflow turbine 110 . It should be understood that cabin recovery valve 112 or outflow turbine 110 might include an integral anti-depressurization valve to guard against inadvertent depressurization of the aircraft cabin. That is, should a duct burst or other failure to occur, anti-depressurization valve will close to prevent further depressurization of the aircraft cabin. The anti-depressurization valve may be a conventional aerodynamic valve that closes upon sensing too much air flow.
[0029] Cabin air 114 is directed through outflow turbine 110 where it is quickly expanded. This expansion of cabin air 114 causes a rapid temperature drop of cabin air 114 , which is directed through passage 116 to heat exchanger assembly 20 . This cooled air serves to supplement ram air 100 , thereby reducing the drag associated with the ram air system by not requiring as much outside ambient air for heat exchanger assembly 20 cooling. Moreover, the power generated by outflow turbine 110 serves to reduce the work required by motor 68 when driving second compressor 14 . A significant electrical power and ram air drag saving is achieved as the cruise phase is the majority of the entire flight.
[0030] Still referring to FIGS. 3 and 4, during ground or low altitude operation, air conditioning system 10 ′ works identically to air conditioning system 10 . However, during high altitude operation, as described above, cabin air 114 is expanded and cooled in outflow turbine 110 and is passed to heat exchanger assembly 20 for cooling. Like air conditioning system 10 , condensing loop 72 is bypassed using altitude valve 70 . The opening of altitude valve 70 bypasses condensing loop 72 such that primary cooling of the air occurs in heat exchanger assembly 20 , supplementing with expanded cabin air 114 , and second turbine 18 . This arrangement, at altitude, enables the overall pressure drop in system 10 ′ to be minimized so as to provide sufficient flow to the passenger cabin at lower power consumption levels.
[0031] According to a third embodiment of the present invention, an air conditioning system 10 ″ is illustrated that is capable of eliminating the use of bleed air and further capable of utilizing the potential energy of pressurized air leaving the aircraft cabin during high altitude flight. However, unlike the second embodiment of the present invention, air conditioning system 10 ″ employs a series of control valves such that first turbine 16 acts similar to outflow turbine 110 of the second embodiment.
[0032] More particularly, as best seen in FIGS. 5 and 6, in addition to those elements described in reference to FIGS. 1 and 2, air conditioning system 10 ″ further includes a first cabin recovery valve 210 . First turbine 16 receives previously conditioned air 114 from the cabin of the aircraft through first cabin recovery valve 210 . First cabin recovery valve 210 is variably actuated to control the preferred flow of conditioned air 114 into passage 50 . Conditioned air 114 joins air flow within passage 50 and is directed to first turbine 16 where it is expanded and cooled. It should be understood that first cabin recovery valve 210 or first turbine 16 may include an integral anti-depressurization valve to guard against inadvertent depressurization of the aircraft cabin. That is, should a duct burst or other failure to occur, anti-depressurization valve will close to prevent further depressurization of the aircraft cabin. The anti-depressurization valve may be a conventional aerodynamic valve that closes upon sensing too much air flow.
[0033] Air conditioning system 10 ″ further includes a second cabin recovery valve 212 disposed within passage 50 upstream from the inflow of cabin air 114 . Second cabin recovery valve 212 is selectively actuated to prohibit air flow from reheater 22 to first turbine 16 and backflow of cabin air 114 to reheater 22 . A third cabin recovery valve 214 is disposed within a passage 216 interconnecting passage 52 and heat exchanger assembly 20 . A check valve 218 is further disposed in passage 52 downstream from the interconnection with passage 216 . Check valve 218 prevents backflow of air from condenser 24 in the event of a failure of third cabin recovery valve 214 .
[0034] Still referring to FIGS. 5 and 6, during ground or low altitude operation, air conditioning system 10 ″ works identically to air conditioning system 10 . However, during high altitude operation, cabin air 114 is expanded and cooled in first turbine 16 and is passed to heat exchanger assembly 20 for cooling. Like air conditioning system 10 , condensing loop 72 is bypassed using altitude valve 70 and the bypass valves are actuated to direct cabin air 114 to first turbine 16 and heat exchanger assembly 20 . Specifically, first cabin recovery valve 210 is opened to allow flow of cabin air 114 into a passage 220 . Cabin air 114 is then directed to first turbine 16 via passage 50 by closing second cabin recovery valve 212 . Cabin air 114 is then expanded and cooled and used to supplement ram air 100 in heat exchanger assembly 20 . Check valve 218 prevents flow through a failed-open valve 214 to the ram system. The opening of altitude valve 70 bypasses condensing loop 72 such that primary cooling of the air occurs in heat exchanger assembly 20 , supplementing with expanded cabin air 114 , and second turbine 18 . This arrangement, at altitude, enables the overall pressure drop in system 10 ″ to be minimized so as to provide sufficient flow to the passenger cabin at lower power consumption levels.
[0035] In addition to the above embodiments described in detail, there are numerous modifications that are anticipated to further tailor the air conditioning system of the present invention. However, it must be understood that each of the following modifications, although described together, is individually applicable to the above described embodiments. That is, each modification may be employed separately from the remaining modifications, if desired. They are simply being described together here in the interest of brevity.
[0036] Referring to FIG. 7, it should be understood that ram air fan 28 may alternatively be coupled to second compressor 14 , generally indicated at 28 ′. Ram air fan 28 ′ would thus supply ram air to second compressor 14 . Still referring to FIG. 7, primary heat exchanger 32 may be eliminated if it is determined that a two-stage heat exchanger system is not required, thereby generally designated as 20 ′. Similarly, motor 68 may be eliminated if added mechanical input is not required between second compressor 14 and first turbine 16 . Likewise, second turbine 18 may be eliminated if the necessary temperature and pressure are achieved depending on the equipment used and the aircraft requirements. However, it is preferable that if second turbine 18 is eliminated, then turbine bypass valve 64 be similarly eliminated since its use is now defeated. Alternatively, turbine bypass valve 64 may be repositioned between passage 50 and passage 52 , thereby serving to selectively bypass first turbine 16 .
[0037] Existing aircraft require the use of bleed air to operate the aircraft air conditioning system. However, bleed air requires a significant amount of fuel burn where a significant amount of energy is wasted by the processing of the bleed air. Hence, there is a need in modern designs to alleviate the use of bleed air in air conditioning systems. According to the principles of the present invention, an all electrical air conditioning system is provided that eliminates the need for bleed air. Moreover, the present invention enables much of the energy of the conditioned air within the cabin to be recovered, thereby reducing electrical power consumption. The elimination of the use of bleed air enables aircraft engines to be more efficiency designed, thereby reducing the use of fuel. It should be appreciated that extracting electricity from jet engines is much more efficient than extracting bleed air. Still further, the present invention provides a method of reducing the weight and maintenance requirements of the aircraft since engine pneumatic ducting, APU ducting, and pneumatic components are eliminated. Duct leaks may be eliminated or at least reduce while overheat detection systems may no longer be necessary. Additionally, air conditioning systems may be modularized, since they no longer need to be sized relative to APU/Engine pneumatic operation performance.
[0038] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | An all electric air conditioning system for an aircraft, wherein the aircraft defines an interior volume having conditioned air at a first pressure. A compressor is provided and is operable to compress supply air to a second pressure. The compressor being operated in response to an electrical drive motor. A passage fluidly couples the compressor and the interior volume of the aircraft. A heat dissipating device, such as a heat exchanger, is positioned in the passage to extract heat energy from the supply air. This arrangement permits conditioning of air within the aircraft without using bleed air from the engines. The use of bleed air results in a significant amount of fuel burn. An optional conditioned air recovery system may be coupled to the interior volume of the fuselage to direct at least a portion of the conditioned air from the interior volume back for further conditioning and use. | 1 |
FIELD OF THE INVENTION
This invention relates to computer systems and more particularly to programming within such computer systems. Even more particularly, the invention relates to processing errors within a computer program.
BACKGROUND OF THE INVENTION
When developing a complex application or complex system of applications, an error handling system is needed that handles normal error conditions in the application or system and unexpected exceptions caused by the inevitable software errors made by the developer of the application or system. Complex applications or systems often create difficult error handling problems for the user of the system. The error handling must have a uniform look and equal access to the help system supplied with the application or system. Ideally, exceptions are reported through the same error handling as expected error conditions are reported. In a complex application or system, errors and exceptions may occur concurrently in different processes and if improperly handled, may cause a bewildering series of error messages to occur and, sometimes, create more exceptions in an attempt to concurrently access the error handling or help system.
One important aspect of error processing is to attempt to produce the earlier error message first within the system. That is, the first process to detect an error more often finds the actual, or root, cause of the error, and it is important that the error message displayed by this first process be the first or top most error message on the display screen connected to the computer system that displays the error. This may not occur if multiple processes detect the error, since some of those processes may have a higher priority than the process that first detected the error, and the process with the higher priority will display its message before the other processes. In this situation, the message from the process that first detects the error may be buried within the user screen and not easily visible.
Another problem that can occur is that one or more processes may consume all the memory available within the computer system. When this happens, there is insufficient user memory for the error process to display an error message. Thus, the user is uninformed and the system simply "crashes", without informing the user as to the cause of the "crash".
Another problem that can occur between applications that are distributed over more than one computer, is that the application may have a problem on a remote computer and the user at the local computer, who is actually running the process, will be unaware that an error has occurred or unaware of the cause of the error. Thus, it is important when an error occurs in a distributed system, that error messages be displayed on all computers that are operating the distributed system.
There is need in the art then for an improved system for displaying error messages in an application or system of applications. There is a further need for such a system that attempts to display the first occurring error on the most prominent portion of the computer screen attached to the process that is running. Another need is for such a system that gives equal access to a help file for all errors. Still another need is for such a system that can display out of memory error messages, even though the system has no memory available for use in constructing the error message. A still further need is for such a system that can remotely display errors in an application or system application. The present invention solves these and other needs in the art.
SUMMARY OF THE INVENTION
It is an aspect of the present invention to process errors within a common process of a computer system.
It is another aspect of the invention to detect errors within each process of the computer system and transfer the error information to a common error processing process of the computer system.
Another aspect is to provide all help information from the common error processing process within the computer system.
Another aspect of the invention is to transfer error information to a second computer system connected to the computer system.
A further aspect of the invention is to reserve memory when the system is initialized, and then release the memory in the event of a memory error, so that the released memory can be used to process the memory error.
The above and other aspects of the invention are accomplished in a system that uses a common error processing process within the computer system wherein other processes that detect errors send an error message to the common process and the common process is used to display all error messages, and display the help file. By displaying all error messages from the common process, the messages are more likely to come out in a correct order of discovery of an error, when multiple processes detect the same error.
The common error process detects whether the system is a distributed application running on multiple computer systems, and if this is so, the common error process sends any error messages to other computers within the distributed network, so that the error messages are displayed on all computers when one computer has an error. This insures that the user of the distributed application will receive the error message, regardless of which computer they are actually using to run the application.
The invention also reserves an amount of memory in each process when it is started, and keeps this memory reserved throughout operation of the system. If an out of memory error occurs in another process, the reserved memory is released, to provide sufficient memory for building an error message. This insures that an error message indicating an out of memory condition is reported to a user of the system.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features, and advantages of the invention will be better understood by reading the following more particular description of the invention, presented in conjunction with the following drawings, wherein:
FIG. 1 shows a block diagram of a computer system incorporating the present invention;
FIG. 2 shows a block diagram of the modules of the present invention;
FIG. 3 shows a flowchart of the method of using the present invention;
FIG. 4 shows a flowchart of the catch block called from FIG. 3; and
FIG. 5 shows a flowchart of the error processor of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description is of the best presently contemplated mode of carrying out the present invention. This description is not to be taken in a limiting sense but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined by referencing the appended claims.
FIG. 1 shows a block diagram of a computer system incorporating the present invention. Referring now to FIG. 1, a computer system 100 contains a processing element 102 which communicates to other elements of the computer system 100 over a system bus 104. A keyboard device 106, and a graphical user input device 108, such as a mouse, provide input to the computer system 100 while a graphics display device 110 allows software within the computer system 100 to output information to a user of the computer system 100. A disk 112 stores software and data within the computer system 100.
Also contained within the computer system 100 is a memory 116 which contains an operating system 118. The operating system 118 may be any number of commercially available operating systems, such as the Microsoft Windows operating system. The memory 116 also contains application software 120 which contains the error processing system of the present invention.
A communications interface 114 allows the computer system 100 to communicate to other systems, such as the remote computer 124 over a network 122. The network 122 may be a local area network (LAN) or a wide area telecommunications network. This communication allows the error processing system, within the application software 120, to communicate to an error processing system within the remote computer 124 to display error messages on both computer systems.
FIG. 2 shows a block diagram of the application software 120 of FIG. 1, as well as a block diagram of an equivalent application software process running in the remote computer 124. Referring now to FIG. 2, the application software 120 contains a system control process 202 which contains an error processor 203 of the present invention. The application software 120 also contains one or more view processes 204 and one or more tool processes 206 which perform other functions within the application software. Within the view process 204 is an error process 210, of the present invention, which reports errors that occur within the view process 204. Similarly, the tool process 206 contains an error process 212 which reports errors that occur within the tool process 206.
The view process 204 typically represents an application program, as this term is commonly understood on computer systems, and the tool process 206 represents a system utility or other utility program or function used by the view process 204. Thus, either an application program, or a system tool, can report errors using the present invention.
When an error occurs, for example within the view process 204, the error process 210 of the view process 204 builds an error message and sends this error message to the error processor 203. This is typically done in the windows operating system using object linking and imbedding (OLE). Those skilled in the art will recognize, however, that the message could be sent using any type of interprocess communication mechanism within the operating system.
The error processor 203 receives the error message, formats it and sends it to an error graphical user interface (GUI) 208 for display on the graphics output device 110 (FIG. 1). A second application software process 220 represents an application software process that would run in the remote computer 124 (FIG. 1). This process has equivalents of the elements of the process 120 operating in the local computer system 100 (FIG. 1).
When an error occurs in either computer system, and that error is reported to the respective error processor within the computer system, that error processor can refer to the system to determine whether the remote computer system is attached. When the remote computer system is attached, the error processor in the computer system that detected the error asks the system to send the message over the network 122 (FIG. 1) to the error processor in the other computer system, and the error processor in the other computer system displays the error message using its error graphical user interface. Thus, for the example described above, error processor 203 would send the error message over the network 122 to error processor 223 which would display the error on its graphical user interface 228. This allows errors that occur in either computer system to be displayed on both computer systems.
FIGS. 3 and 4 show a flowchart of the error process 210, and the error process 212 of FIG. 2. The error process of FIGS. 3 and 4 is the same for each process in which they are performed, thus the error process of FIGS. 3 and 4 are performed within each view or tool process. Referring now to FIG. 3, when the process is started, block 302 initializes the error process. Block 304 then reserves an area of memory for use in the event of an out of memory error condition.
The present invention uses the try/catch error system available in ANSI standard C++, however, those skilled in the art will recognize that the present will work with other error detection systems. The try/catch method defined in ANSI C++ puts all the code being executed by the application, which can potentially cause an error, into a "try" block. Following each try block, is a "catch" block, which determines whether an error has occurred and takes appropriate action. The present invention uses this conventional try/catch mechanism to detect the original error.
Thus, the code of the application is performed within a try block 306. After this code is performed, block 308 determines whether an error has occurred, and if not, block 308 simply returns to the user. If an error has occurred, block 308 transfers to block 310 which calls the catch block processor of FIG. 4. Those skilled in the art will recognize that the error detection of block 308 is built into the try/catch mechanism of ANSI C++, and is not ordinarily visible to the programmer writing code that uses the try/catch mechanism.
Table 1 shows a code example of the code of FIG. 3, which uses the try/catch mechanism. In this example, the catch part of the mechanism is incorporated within a macro called "CATCH -- AND -- CLOSE". This macro is shown in Table 2 along with another macro that it uses. The use of macros within the mechanism is not important to the invention, and is simply a convenient way of writing the code.
FIG. 4 shows a flowchart of the catch block code called from block 310 of FIG. 3. Referring now to FIG. 4, after entry, block 402 determines whether timers are running. If timers are running, block 402 calls block 404 which stops the timers. The determination as to whether the timers are to be stopped is implemented in the present invention by choosing one of two different macros to implement the catch block. Those skilled in the art will recognize that this could also be implemented as a specific test within the catch block.
Block 406 then determines whether the error that occurred was an out of memory error. If the error was an out of memory error, block 406 goes to block 408 which frees the memory that was reserved by block 304 (FIG. 3). By freeing this memory, the present invention supplies enough memory to the operating system to allow room for building the error message, as described below.
If the error was not an out of memory error, or after freeing the reserve memory, control goes to block 410 which builds the error message for the error, and then block 412 sends this error message to the error processor 203 (FIG. 2). In the present invention, the error message is sent to the error processor using the OLE mechanism of the Microsoft Windows operating system.
After sending the error message, block 414 determines whether the catch block is to perform a close down, and if so, block 414 transfers to block 416 which calls the application close down routine. After performing the close down, or if no close down was to be performed, control returns to FIG. 3. In the present invention, the choice of whether a close down is to be performed is determined by using one of two macros to perform the catch block function in the same manner as described above with respect to the stop timers function.
FIG. 5 shows a flowchart of the error processor 203 (FIG. 2), this is identical to the error processor 223 shown in FIG. 2. This error processor receives control when a message is sent by one of the error processes 210 or 212, as described above with respect to FIGS. 3 and 4. Referring now to FIG. 5, after entry, block 502 retrieves the error message sent by the error process 210 or 212. Block 504 then formats this error message for display to the user, block 505 finds a reference in the help system for the message and inserts it into the message, and block 506 sends the formatted message to the error GUI 208 (FIG. 2), where the message is displayed to the user. In the present invention, the error message is sent to the error processor using the OLE mechanism of the Microsoft Windows operating system.
After sending the formatted message, control goes to block 508 which determines whether communication is available to a second computer system that is performing the application software 120 (FIG. 1). If communication is available, control goes to block 510 which sends the unformatted message to the second computer system 124 (FIG. 1). The unformatted message is sent because it is smaller than the formatted message, thus saving time. After sending the unformatted message, or if no communications was available, FIG. 5 simply completes its process and returns to the operating system.
Because the error processor of the flowchart of FIG. 5 is a separate process within the computer system, and all error messages are transferred to the error processor for display, there will not be any priority conflict as to which messages are displayed first. Thus, since all error messages are displayed by the error processor, the first error message received will be displayed first, and this error message is most likely the error message produced by the process that first discovered the error condition.
Having thus described a presently preferred embodiment of the present invention, it will be understood by those skilled in the art that many changes in construction and circuitry and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the present invention as defined in the claims. The disclosures and the description herein are intended to be illustrative and are not in any sense limiting of the invention, defined in scope by the following claims.
TABLE 1______________________________________try { //processing of the application functions } CATCH.sub.-- AND.sub.-- CLOSE(CerrorNumber, ProcessId)}______________________________________
TABLE 2______________________________________#define CATCH.sub.-- AND.sub.-- CLOSE( CerrorNumber, ProcessId ) {\catch( CMemoryException &ce ) \ {CleanUp () ;REPORT.sub.-- MEMORY.sub.-- EXCEPTION(CerrorNumber,\ProcessId) ;Closedown () ; }#define REPORT.sub.-- MEMORY.sub.-- EXCEPTION(CerrorNumber, ProcessId)\ //send error message to Error Processor______________________________________ | A system uses a common error processing process within a computer system wherein other processes that detect errors send an error message to the common process and the common process is used to display all error messages, and display the help file. The common error process detects whether the system is a distributed application running on multiple computer systems, and if this is so, the common error process sends any error messages to other computers within the distributed network, so that the error messages are displayed on all computers when one computer has an error. The system reserves an amount of memory when it is started, and keeps this memory reserved throughout operation of the system. If an out of memory error occurs in a process, the reserved memory is released, to provide sufficient memory for building an error message. | 6 |
TECHNICAL FIELD
This invention pertains to methods of fabricating a one-piece fiber reinforcement from a number of co-extensive, separate and distinct reinforcing fibrous structures arranged in layered fashion. The method involves intermingling fibers from the different layers so that at least some of the fibers from each layer are inserted into an adjacent layer and bridge the original layer interface to engage with, and interfere with, at least some of the fibers of at least one other layer to interlock the layers. The invention, applied over substantially the entire lateral extent of the individual reinforcements, may be used to fabricate reinforcements with improved resistance to delamination and simplify manufacture of fiber reinforced polymer composites.
BACKGROUND OF THE INVENTION
There is increasing interest in substituting high performance lightweight reinforced composite components and structures comprising a polymer matrix with a suitable reinforcement for stamped sheet metal components in vehicles. Suitable polymers are often thermosets, such as epoxies, vinyl-esters or polyesters, or thermoplastics, such as polypropylene or poly amide, and suitable reinforcements include structural fibers such as carbon, glass or aramid fibers. Such fibers may be randomly oriented and arranged or aligned along one or more preferred directions.
Individual carbon fibers may range from about 5 to 10 micrometers in diameter with 7 micrometer diameter fibers being especially common. Individual glass fibers may range from about 7 to 30 micrometers, depending in part on the grade of glass. In many applications, particularly those employing aligned fibers, assemblages of commonly-oriented fibers, variously called tows or roving, are used. Such carbon fiber assemblages may contain as few as 1000 or as many as 50,000 or more fibers, while glass fiber assemblages may include up to 200,000 or more fibers.
For fabric applications, aligned fibers may be assembled into one of two fabric structures for ease of application: a woven cloth or a non-woven fabric often called a non-crimp or stitch bonded fabric. A woven cloth employs tows of a first orientation which alternately overlie and underlie fiber tows of a second orientation, usually at about 90° to the first orientation. The weave may be tight, with adjacent tows positioned about a millimeter or less apart, or loose, with adjacent tows spaced up to about 10 millimeters apart. In an alternative structure, a number of spaced apart fiber rovings, individually fed from their respective spools, may be simply laid alongside one another in a ply, and temporarily secured and locked into place, by stitching, using, for example, a polyester yarn. Such stitching generally extends over the length and breadth of the reinforcement ply and is usually accomplished with a stitch beam which incorporates a plurality of needles and has a suitable motion to enable both simple chain stitches and other more complex stitches, for example tricot stitches. In many cases multiple coextensive plies are laid atop one another and the rovings of all of the plies are secured in a single stitching operation. Often the plies are placed with the fiber orientations of adjacent plies rotated one from another to render the in-plane properties less directional, or more isotropic, in the multi-ply reinforcement than in each ply individually. The weight of each ply is determined by the bulk of the roving and the spacing between adjacent roving bundles. These, non-woven reinforcements are called stitch bonded fabrics or non crimp fabrics, often abbreviated as NCF.
One common example of a multi-ply NCF is a 4-layer grouping of fibers arranged at 0°, +45°, −45° and 90° respectively with substantially equal numbers of fibers in each orientation. A 2-layer NCF with fibers arranged at +45° and −45° also finds wide application. Of course this description of such a multi-ply NCF is intended to be exemplary and not limiting. It will be appreciated that variations in the number of plies, in the number of orientations, in the angular alignment of the fibers within any ply and in the fiber density in each orientation are comprehended by the terminology non-crimp fabric, stitch bonded fabric, NCF, NCF fabric or aligned fiber layer as used in this specification.
Such fabric reinforcements, woven or non-woven, may be impregnated with a suitable polymer resin, placed in a mold, shaped and then cured, typically at modestly elevated temperature, say about 150° C., to form the desired polymer composite. It will be appreciated that the above-listed sequence of operations may be modified for different molding processes. For example, preforms may be placed in a mold with resin already impregnated, or the resin can be added after the preform is in the mold via resin infusion, resin transfer molding, or structural resin injection molding. Thermoplastic or thermoset sheets or materials with comingled strands of thermoplastic and reinforcing fiber may also be employed.
Commonly, more than one fabric reinforcement may be required to develop the desired properties in the composite. These reinforcements may be stacked atop one another, while possibly rotating or offsetting one layer with respect to another, with the goal of developing greater isotropy, or lack of directionality in properties, at least in the plane of the reinforcement.
Reinforcing layers in which the reinforcing fibers are randomly oriented such as by directed fiber preforming or Programmable Powered Preform Process (P4™ preforming), or one or more layers of continuous strand mat such as Owens Corning 8610 or chopped strand mat also find application. Such reinforcements may, by virtue of the fibers being oriented over all possible orientations, offer more isotropic properties than even a multilayer NCF fabric reinforcement.
One suitable configuration for a multilayer fiber-based polymer composite reinforcement is a layer of randomly-oriented fibers sandwiched between two layers of aligned fibers, which may be assembled as NCF (non crimp fabric) layers or woven layers. But, such multilayer reinforcements are also multi-piece, and require that each reinforcement layer be placed and positioned individually, complicating manufacturing.
There is therefore need for a one-piece reinforcement which facilitates manufacturing of fiber reinforced polymer composite articles and at least meets the performance objective of multilayer, multi-piece reinforcements.
SUMMARY OF THE INVENTION
A layered, one-piece fiber reinforcement suitable for use in a reinforced polymer composite is formed from a plurality of layered, coextensive individual reinforcements in face to face contact. The individual reinforcements may include at least an oriented layer of woven or non-woven reinforcing fabric with oriented fibers and a layer of randomly oriented fibers. A needle punch or similar technique is used to pull or push a preselected portion of the fibers of a layer and insert them into at least an adjacent layer where they may engage with the fibers of the adjacent layer. It is preferred that the fibers engage the layers substantially uniformly over substantially the entire extent of the layer. Frictional interaction and mechanical interference between the fibers from the differing layers will hold, bind and interlock at least adjacent reinforcing layers to one another and render a one-piece reinforcement with enhanced interlayer strength. In reinforcements with more than two layers it may be preferred to thread fibers through all the layers of the reinforcement so that all layers are interlocked. A one-piece reinforcement is thereby effected from a plurality of reinforcing layers. The one-piece reinforcement simplifies manufacturing of fiber reinforced polymer composite articles and provides improved properties over the same arrangement of non-interlocked reinforcing layers.
For example, in an embodiment, a 3-layer reinforcement includes two aligned fiber layers, which may, for example, be NCF layers, with a random fiber layer positioned between them. The random fiber layer may comprise continuous or chopped fibers. A preselected number of fibers from a first aligned fiber layer is pulled or pushed through the random fiber layer and inserted into or through the second aligned fiber layer to frictionally and mechanically securely bind all of the layers together. Optionally, fibers may also be pulled or pushed from the second aligned fiber layer, through the random fiber layer, to the first aligned fiber layer to further secure the layers and effect a one-piece reinforcement. Such extensive fiber rearrangement is not a requirement and fibers may be pulled or pushed from only the random layer to be inserted in one of the aligned layers, or vice versa.
Such a reinforcement, by virtue of those fibers extending out of the plane of reinforcing layer and directed through the reinforcement thickness, will impart enhanced interfacial strength at the layer interfaces to a reinforced polymer article. Such increased interfacial strength may suppress delamination and enhance the energy adsorption afforded by the article under severe loading. This benefit may also obtain with layered chopped strand mat or continuous strand mat reinforcements. Because the location of such load application may be indeterminate, the layers should be bound together over substantially their entire extent with the engaging fibers generally uniformly distributed over the entire area of the layer(s). But it may be preferred to concentrate the engaging fibers at load application sites if these may be predicted, for example by simulation or modeling, or are known from experience or experiment.
Needle punching employs an elongated tool, with a shaft incorporating at least one feature adapted to engage and capture fibers when the tool is moved in a first direction, and, when the tool is moved in the reverse direction, release the captured fibers. The tool, which may be needle-shaped with a diameter of from about 0.5 to 1 millimeter, is operated with a reciprocating motion so that it is repeatedly inserted into, and withdrawn from, a fiber-containing layer. In a tool with a plurality of fiber-capturing features, these will typically be distributed along the length and/or around the cross-section of the tool shaft. Generally the fiber capturing features, for example barbs, hooks or flukes, are arranged for unidirectional fiber capture. That is, a fiber in sliding contact with the tool shaft will be captured and retained by the fiber capturing feature under only one of the tool's reciprocating motions. Often the fiber-capturing feature is oriented to capture fibers as the needle or tool is inserted into a fiber layer so that with each insertion of the tool, fibers captured by the barb(s) or similar, during an early part of the stroke will be pushed more deeply into the fiber layer as the tool continues to advance. At the end of the tool stroke, as the tool reverses direction and is withdrawn, the fiber will disengage from the unidirectional fiber capturing feature but will be held in place through frictional engagement with other fibers or through mechanical interference with other fibers. Because the fiber capturing feature is unidirectional, the tool is ill-oriented and unsuited to capture any further fibers during retraction, and so may be readily withdrawn. Repeated insertions and withdrawals, usually accompanied by lateral movement of the tool to previously unprocessed areas, will promote increasing engagement, entanglement and interference between the fibers from the upper and lower sections of the layer. This procedure may be continued until the layers are secured to one another by a suitable number of inserted fibers across substantially their entire extent. Generally the number of inserted fibers per unit area will be substantially uniform across the extent of the reinforcement but a greater areal density of inserted fibers may be employed in more highly stressed regions if required.
Higher productivity may be achieved through the use of multiple tools, operated independently or ganged together in a common fixture. When multiple tools are employed the tools may be supported by plates incorporating a plurality of close-fitting holes suitably positioned to receive the tools. Also the fabric layer may be supported on a similar, hole-containing, tool receiving plate or on a fiber array oriented parallel to the tool or on a support body which may be penetrated by the tool without damage to the tool, such as a solid or foam soft rubber body.
Although a common embodiment employs fiber capturing features oriented to enable fiber capture during only one of the up-down strokes of a reciprocating tool, tool variants suitable for fiber capture on both of the up and down strokes may be employed.
The strength of a joint formed between layers in a layered one-piece reinforcement will depend, primarily on the number of fibers of each layer which interferingly engage with the fibers of the abutting layer and so will generally depend on the number of tool strokes. If fiber-engaging features are distributed along the length of the tool, the extent of fiber engagement and interference may also depend on the length of the tool stroke. Commonly such needle punch or similar procedures may be applied from only a single side so that the tool will always enter the layer stack on a particular surface of a particular layer. But, to achieve more robust fiber intermingling, the procedure may also be applied from both sides of the stack. Where such two-side needle punching is preferred it may be carried out either by using two sets of opposing tools or by using a single tool set from one direction and then interchanging the top and bottom surfaces of the stack and performing a second needle punching operation.
Such a one-piece reinforcement is effective in imparting increased strength and fracture resistance to a reinforced polymer article. Most reinforced polymer components are substantially two-dimensional in character with a thickness appreciably less than their lateral extent. Planar reinforcements are usually oriented to enhance lateral properties and are assembled one atop the other without interconnection. After impregnating the layers with a polymer resin and curing of the composite, the layers are secured to one another by only whatever thickness of polymer is trapped between them. Under high impact loads, if the polymer fractures or releases from one or other of the layers, delamination or separation of the reinforcement layers may occur. Once delaminated the layers are rendered incapable of providing mutual support and act independently, diminishing their effectiveness.
With the one-piece reinforcement of the present invention, fibers from one layer may be inserted into at least an adjacent layer so that these fibers serve as reinforcements which extend between and span layers. These inserted fibers will be oriented out of the plane of the reinforcing layers, commonly, but without limitation, within ±10° of perpendicular to the layer interface, and, after curing, secured in position by adhesion between the fibers and the polymer. Further, these fibers, in contrast to the fibers in the reinforcement layers, will follow a tortuous path which will be effective in resisting fiber pull-out from the polymer matrix. With the inter-layer reinforcement contributed by these layer-spanning fibers, the reinforcement will be less likely to delaminate under severe loads and so may provide enhanced performance over assemblies of reinforcing layers without such layer-spanning interlocking fibers.
The fiber content of such a one-piece reinforcement may include all commonly-used reinforcing fibers including, but not limited to, carbon fibers or glass fibers, as well as aramid fibers.
A fiber reinforced polymer article containing such a one-piece reinforcement may be fabricated by the following steps (though, depending on the particular molding process used, not necessarily in this order): assembling a layered reinforcement by stacking a plurality of generally planar, generally coextensive fiber-containing reinforcements atop one another in face to face relation; conveying a preselected portion of the fibers from at least one layer of the layered reinforcements out of the plane of the reinforcement and pulling or pushing them into to at least a second layer of reinforcement to secure the reinforcements together and repeating until all layers are bound to one another; impregnating the reinforcement with a suitable polymer precursor in sufficient quantity to wet all of the fibers and to fill a mold cavity; shaping the polymer precursor-impregnated reinforcement to a preselected geometry suitable for production of the article and thereby forming a pre-preg; placing the pre-preg in a mold with an interior cavity defining the desired article shape; closing the mold to induce the prepreg to conform to the shape of the die cavity, to compact the prepreg and to displace and distribute polymer precursor throughout the mold cavity; and curing the polymer precursor in the shaped pre-preg to form the fiber reinforced polymer article. One-sided vacuum-bag or autoclave molding may also be employed.
These and other aspects of the invention are described below, while still others will be readily apparent to those skilled in the art based on the descriptions provided in this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows, a schematic representation of a number of aligned and random reinforcements suitable for reinforcing a reinforced polymer article. FIG. 1A shows, in plan view, a woven reinforcement; FIG. 1B shows in perspective view, a non-woven reinforcement; FIG. 1C shows, in plan view, a continuous mat reinforcement; and FIG. 1D shows in plan view a chopped mat reinforcement.
FIGS. 2A-G show, in cross-section, a series of schematic representations of a needle-punch tool entering and withdrawing from a 3-layer reinforcement with two aligned fiber outer layers and a random fiber inner layer. The tool is adapted to capture a fiber on removal from the reinforcement.
FIGS. 3A-F show, in cross-section, a series of schematic representations of a needle-punch tool entering and withdrawing from a three layer reinforcement with two aligned fiber outer layers and a random fiber inner layer. The tool is adapted to capture a fiber on entering the reinforcement.
FIGS. 4A-B shows, schematic illustrations of two bi-directional needle punch tools adapted to capture fibers on both entering and withdrawing from a fibrous body.
FIGS. 5A-C shows, in cross-section, the operation of a reconfigurable needle punch tool in which the fiber capture feature may be: retracted— FIG. 5A ; oriented to capture fibers— FIG. 5B ; and oriented to disengage fibers— FIG. 5C . FIG. 5D shows, in fragmentary cross-section, an alternative fiber capture feature design.
FIG. 6 shows, in quasi-perspective view a three-layer reinforcement stack with fiber loops extending though the layers to interlock and bind the layers together.
DESCRIPTION OF PREFERRED EMBODIMENTS
Fiber reinforced polymer composite articles find increasing application where low mass and high strength are required. Often the composite reinforcement is itself a composite of several different, generally coextensive reinforcing fiber layers stacked or layered atop one another. The reinforcements may be aligned woven or non-woven fibers, or randomly arranged and positioned fibers which may be continuous, or chopped. Illustrative examples of such reinforcements are shown in FIGS. 1A-D and may comprise without limitation, carbon fibers, glass fibers, and aramid fibers.
FIG. 1A shows a portion of a woven reinforcement 10 comprising warp fibers 12 arranged into tows 14 which alternately overlie and underlie weft fibers 16 arranged into tow(s) 18 . FIG. 1B shows a four layer non-crimp fabric (NCF) 20 in which roving layers 25 , 27 , 29 , 31 containing oriented spaced-apart roving 24 , 26 , 28 , 30 each containing fibers 22 (shown only once for clarity) are laid down in layered fashion and secured by tricot stitching 32 .
FIG. 1C shows a random continuous fiber mat 34 in which a plurality of continuous fibers 36 , have been laid down in a generally random manner in a generally planar, but layered configuration. FIG. 1D shows a random chopped fiber mat 38 in which lengths of chopped fiber, for example fiber 40 (shown in heavier weight line for clarity) have been randomly arranged to form a generally planar, but layered, array. It will be appreciated that although the fiber density shown in both of FIGS. 1C and 1D is relatively low for ease of viewing, typical fiber mats may have many more overlying fibers and may have appreciable thickness.
FIGS. 2A-G show how a group of three discrete and initially unattached fiber reinforcing layers, 50 , 52 , 54 may be secured into a one-piece reinforcement by the action of tool 56 with fiber engaging feature 58 . Reinforcing layers 50 , 54 are aligned fiber reinforcement layers, here depicted, without limitation or restriction, as four-layer stackups of aligned reinforcing fiber rovings similar to the NCF shown in FIG. 1B . Reinforcing layers 50 and 52 could equally be NCF fabrics with fewer or greater layers of woven fabrics without limitation. Without limitation, reinforcing layer 52 is shown as a random fiber layer similar to either of the continuous fiber or chopped fiber mats shown in FIGS. 1C and 1D .
In FIG. 2A , point 59 of tool 56 , moving as indicated by arrow 57 and guided by opening 64 in top plate 60 just penetrates the upper fiber layer 51 of aligned fiber reinforcement 50 . Continued motion of tool 56 , shown at FIGS. 2B-D progressively drives tool 56 through, successively, reinforcing layers 50 , 52 and 54 , until, as shown at FIG. 2D , tool point 59 emerges from lower fiber layer 55 of aligned fiber reinforcement 54 and just engages opening 63 in lower support 62 . Throughout tool advance, no fiber capture occurs because capture surface 68 and guidance surface 66 which together define fiber capture feature 58 are not arranged to engage and capture any of the fibers encountered by tool 56 as it advanced in the direction of arrow 57 . At FIG. 2E , after point 59 has penetrated lower aligned fiber reinforcement 70 , the direction of motion of tool 56 has reversed and is now indicated by arrow 57 ′, enabling capture surface 68 to engage with fibers from roving layer 53 of lower aligned reinforcement 70 , or, as shown, all of roving layer 53 to form and carry roving loop 53 ′ upward through reinforcing layers 52 and 50 as shown in FIGS. 2F and 2G . Continued motion of tool 56 in direction of arrow 57 ′ will fully disengage tool 56 from opening 64 in upper plate 60 so that by relaxing tension on loop 53 ′ to disengage tool capture surface 68 from loop 53 ′, tool 56 may be moved laterally to fully disengage loop 53 ′ from capture feature 58 so that the process may be repeated. Loop 53 ′ remains in the position shown in FIG. 2G , inserted into, and engaging, reinforcement layers 52 and 50 .
The direction of motion of tool 56 has been shown as generally perpendicular to the plane of the fiber reinforcements. This is not intended to limit the invention which also comprehends the use of inclined or slanted tools. It will be appreciated that any inclination of the tool will also be manifested in the orientation of the fiber loop(s).
FIGS. 3A-F show, in an alternate embodiment, how a similar group of three discrete and initially unattached fiber reinforcing layers, 150 , 152 , 154 may be secured into a one-piece reinforcement by the action of tool 156 with fiber engaging feature 158 . Similarly to FIGS. 2A-G , reinforcing layers 150 , 154 are aligned fiber reinforcement layers, with four-layer stackups of aligned reinforcing fiber rovings similar to the NCF shown in FIG. 1B . Reinforcing layer 152 is shown as a random fiber layer similar to either of the continuous fiber or chopped fiber mats shown in FIGS. 1C and 1D .
The particular number, arrangement and character (aligned or random fiber; woven or non-woven; number of fibers or plies per layer) of the layers shown in FIGS. 3A-F are exemplary only and no limitation of the scope of the invention is intended or should be inferred from the particular reinforcing layer arrangement shown.
In FIG. 3A , point 159 of tool 156 moving in a direction 157 is shown penetrating several of plies of reinforcing layer 150 while fiber capture feature 158 has not yet engaged the upper ply 151 of layer 150 . Tool 156 may, like tool 56 shown in FIGS. 2A-G , be supported by openings in a top plate and by openings in a lower support like those shown as 64 in (top) plate 60 and openings 63 in (lower) support 62 in FIGS. 2A-G . These features have been omitted from FIGS. 3A-F for clarity. At FIG. 3B tool 156 has further advanced in the direction of arrow 157 so that capture surface 168 of fiber capture feature 158 has engaged a fiber loop 153 from reinforcing layer 151 of reinforcement 150 . Fiber loop 153 is guided into contact with capture surface 168 by guidance surface 166 . With continued advance in direction of arrow 157 , shown at FIG. 3C , tool 156 penetrates deeper into the reinforcement stack defined by reinforcement layers 150 , 152 and 154 engaging a second thread loop 153 ′ originating in ply 151 ′ of layer 150 . At FIG. 3D , fiber loops 153 and 153 ′ have been pulled out of the plane of layer 150 and extended through the reinforcement stack and below ply 155 of layer 154 . In so doing, fiber loops 153 and 153 ′ bridge the interfaces between layers 150 and 152 as well as between layers 152 and 154 . Fiber loops 153 and 153 ′ are directed generally perpendicular to the plane of layer 151 . As tool 156 is withdrawn in the direction of arrow 157 ′ ( FIGS. 3D-F ), displaced fiber loops 153 and 153 ′, now inserted into reinforcing layers 152 , 154 are frictionally and interferingly engaged by the fibers of reinforcing layers 154 and 152 . The frictional restrain applied to loops 153 and 153 ′ causes them to disengage from fiber capture feature 158 and remain in their displaced configuration. Tool 156 may be laterally displaced and re-inserted into the reinforcement stack to repeat this process until a suitable and predetermined number of fibers has been inserted into adjacent reinforcing layer(s).
Repeated application of the processes shown in FIGS. 2A-G and 3 A-F will result in a plurality of fibers or fiber tows or roving which will extend through the thickness of the reinforcement stackup. These fibers, through frictional engagement with other fibers in the stackup and/or through mechanical interference with other fibers in the stackup will induce sufficient cohesion between the reinforcement layers to render a one-piece reinforcement. The processes shown in FIGS. 2A-G and 3 A-F are intended to illustrate the interaction between an individual tool and the individual layers. To obtain a generally uniform areal density of fibers or tows extending through the layers, an individual tool may be repeatedly inserted and removed while following a path which traverses substantially the entire area of the reinforcement. A second approach, suitable for reinforcements of more limited area, is to employ a plurality of tools, suitably positioned on a common support or fixture, so that all of the tools may be inserted and extracted in concert. A combined approach may be adopted for more extensive reinforcements. A multi-tool fixture may be repeatedly employed and stepped over substantially the entire area of the support until a suitable, and suitably uniform, density of fibers or tows extending through the layers is obtained.
Both top plate 60 and lower support 62 have been shown as sheet-like or plate-like bodies with openings positioned to accept reciprocating tool 56 . Top plate 60 serves to guide and support tool 56 which may, if cylindrical in cross-section have a diameter of less than 0.5 millimeters or so and may break or bend if not supported. But lower plate 62 serves to support the workpiece and ensure that tool 56 is driven into the workpiece rather than bodily displacing it. Alternate designs of lower support 62 may be employed. For example the lower support may be a solid or porous body, capable of penetration by tool 56 , which does not appreciably dull tool point 59 , such as rubber or rubber foam. Alternatively an array of (relatively) widely spaced upwardly pointing fibers or thin columns may be used. With this design the fibers or columns may be present in sufficient number and density to support the workpiece but suitably positioned and spaced apart to at least minimize the possibility of contact between a descending tool and the support columns. In a related design the support columns may be made compliant so that any tool-support contact on tool advance merely deflects or moves the support aside temporarily, enabling to return to its undeflected configuration as the tool is withdrawn.
Because the fiber-capturing action of the tools shown in FIGS. 2A-G and 3 A-F occurs at different stages of the stroke a bi-directional tool, incorporating both fiber capturing features 58 and 158 may be employed. A representative tool 256 is shown in FIG. 4A and includes both of fiber capturing features 58 and 158 . In operation, fiber capturing tool 158 , closer to tool point 259 , will engage the upper surface of a reinforcement stack first and begin to convey fibers from the upper surface view of the stack to the lower surface. As tool 256 advances deeper into the stack, fiber capture feature 58 will be immersed in the stack but, due to its orientation will be unable to engage with or capture any fibers. When the tool reaches the limit of its advance stroke and begins to retract, fiber capture feature 158 will release those fibers which it was conveying and fiber capture feature 58 will capture fibers and begin to convey them toward the upper surface. The stroke of the tool and the placement of the fiber capturing features on the tool, in conjunction with the thickness of the reinforcement stack will determine the origin and extent of the fiber loops. Generally however it is preferred that the loops extend through the entire thickness of the stack for greatest cohesion across all layers.
FIG. 4B illustrates a second configuration for such a tool. It will be appreciated that, to be effective a tool should induce as little damage to the fibers and fiber breakage as possible and for this reason a tool with a small cross-section of say between about 0.5 and 1 millimeter is preferred. But tool geometry will also influence the likelihood of fiber damage from the tool. The angular nature of the tool point 259 and fiber capture features 58 , 158 shown in FIG. 4A may create stress concentrations or otherwise cut or damage fibers. In FIG. 4B , tool 356 is shown with rounded end 359 which may be effective in laterally displacing fibers to enable insertion and passage of tool 356 rather than potentially cutting or otherwise weakening fibers with pointed end 259 . Similarly fiber capture features 58 ′ and 158 ′, though still suited to capture and retain fibers, are shown as having a more rounded, or curved appearance, in both directions to minimize stress concentrations and promote fiber conveyance with minimal damage.
The tool designs shown have exhibited a fixed geometry and relied on the directionality of the fiber capture process to disengage the tool from the fiber when fiber conveyance is terminated, generally when the fibers from one layer have been pulled or pushed through and inserted into at least a second layer. FIGS. 5A-D shows an illustration of a variable geometry tool which may also be effective in conveying fibers through and across layers but may be more effective in minimizing the potential for fiber damage.
The tool 100 , shown, at FIG. 5A in a configuration suitable for penetrating a workpiece consists of a generally cylindrical pin 78 slidably restrained within the inner surface 79 of a hollow cylindrical casing 80 . A plurality of fiber capturing features 88 are pivotally pinned, near extremity 92 , to cylindrical pin 78 at pivots 94 and engage one of a like plurality of openings 82 in casing 80 . The relative positions of pivot 94 , attached to pin 78 , and opening 82 , located in casing 80 determine the orientation of fiber capturing feature 88 . Changing the relative positioning of pivots and openings by moving pin 78 relative to casing 80 enables generally simultaneous adjustment of the orientations of all of the fiber capturing features 86 as shown in FIGS. 5A and 5B . In FIG. 5A , pin 78 and casing 80 are so arranged that fiber capturing features 88 , are supported on pin 94 on one end, and on lower edge 84 of opening 82 , near its other extremity 90 . Thus fiber capturing features 88 are near fully retracted into casing 80 so that only a portion extends beyond casing 80 . In such configuration tool 100 may be directed into a workpiece in direction of arrow 96 with little likelihood of imparting damage to a workpiece fiber 98 in contact with casing exterior surface 81 from fiber capturing features 88 .
In FIG. 5B the direction of tool 100 motion is reversed as indicated by arrow 104 . Also pin 78 has been displaced, relative to casing 80 , in the direction of arrow 91 and so likewise displacing fiber capturing feature 88 in the direction of arrow 91 . Because of its engagement with opening 82 , feature 88 will be guided by upper opening edge 86 or by lower opening edge 84 so it rotates outboard and into a more suitable fiber capturing orientation as well as extending so that extremity 90 of feature 88 protrudes beyond outer surface 81 of casing 80 . In this configuration, features 88 are well-suited to engage any fibers 98 adjacent to outer casing surface 81 as shown at FIG. 5B .
Yet further relative motion of pin 78 with respect to casing 80 as shown at FIG. 5C may result in further extension of fiber capturing feature 88 and also in its further rotation to an orientation in which it is not properly inclined to capture and retain fibers. In this configuration fiber 98 , upon continued motion of tool 100 in the direction of arrow 104 , fiber 98 may ‘roll off’ and disengage from feature 88 . Resetting tool 100 to the configuration of FIG. 5A by moving pin 78 , with respect to casing 80 , in a direction opposite that of arrow 90 enables the cycle to be repeated. Depending on the angular range of motion of fiber capturing feature 88 , it may be feasible to have it operate bidirectionally. With only modest further rotation, fiber capturing feature 88 may be oriented to capture fibers if the direction of motion of tool 100 is reversed. Thus tool 100 may be operated unidirectionally or bidirectionally.
Fiber damage may be further minimized through the use of a more smoothly curved fiber capture feature such as the ‘comma-shaped’ design 88 ′ shown, in fragmentary view, in both retracted (solid line) and extended (broken line) configuration in FIG. 5D .
FIG. 6 shows a depiction of a one-piece layered reinforcement in quasi-perspective view. A three-layer stack 300 comprises reinforcing layers 250 , 252 and 254 represented as woven fiber layers, 250 , 254 and chopped fiber mat layer 252 . These layers are interlocked and bound together by a plurality (not shown) of fiber loops which may include one or more of the individual representative loop configuration 253 , 353 , 253 ′, 353 ′, 253 ″, 353 ″, all shown in heavy line for clarity. Loop 353 , extending from woven layer 254 , passes through and is inserted between the fibers of layer 252 and is further inserted into the woven fibers of layer 250 . Loop 253 , extending from woven layer 250 , passes through and is inserted between the fibers of layer 252 and is further inserted into the woven fibers of layer 254 . Less extensive loops 253 ′ and 353 ′ originate in random fiber layer 252 and are inserted into woven fiber layers 250 and 254 respectively, while loops 253 ″ and 353 ″, originating in woven fiber layers 250 and 254 respectively extend only partway through the stack and are inserted into random layer 252 . The representation shown in FIG. 6 is illustrative and not limiting. For example, other fiber layer configurations may be employed and such alternate fiber layer configurations may enable other loop configurations than those shown. Also and not all possible loop configurations may be found in a specific reinforcement.
A fiber reinforced polymer article containing such a one-piece reinforcement may be fabricated by the following steps, which need not necessarily be performed in the order listed—in particular, it may be preferred to charge the reinforcement with polymer precursor after the reinforcement has been placed in a mold: assembling a layered reinforcement by stacking a plurality of generally planar, generally coextensive fiber-containing reinforcements atop one another in face to face relation; conveying a preselected portion of the fibers from at least one layer of the layered reinforcements out of the plane of the reinforcement and pulling or pushing them out of the plane of the layer across at least one layer boundary to insert the fibers into at least a second layer of reinforcement to secure the reinforcement layers together; and repeating until all layers are bound to one another by fibers extending from one layer and engaging with at least an adjacent layer; impregnating the reinforcement with a suitable polymer precursor in sufficient quantity to wet all of the fibers and to fill a mold cavity; shaping the polymer precursor-impregnated reinforcement to a preselected geometry suitable for production of the article and thereby forming a pre-preg; placing the pre-preg in a mold with an interior cavity defining the desired article shape; closing the mold to induce the prepreg to conform to the shape of the die cavity, to compact the prepreg and to displace and distribute polymer precursor throughout the mold cavity; and curing the polymer precursor in the shaped pre-preg to form the fiber reinforced polymer article.
One-sided vacuum-bag or autoclave molding may also be employed. In this case the pre-preg may be positioned in one-half of a mold cavity and pressure applied to induce the pre-preg to conform to the mold shape.
The practice of the invention has been illustrated through reference to certain preferred embodiments that are intended to be exemplary and not limiting. The full scope of the invention is to be defined and limited only by the following claims. | A one-piece fiber reinforcement for a reinforced polymer is described. In an embodiment, a one-piece reinforcement is fabricated by first assembling an interior randomly oriented fiber layer between two exterior aligned fiber layers. With all layers in face to face contact, a preselected number of fibers from the aligned layer is conveyed out of its aligned layer and threaded into at least the random fiber layer so that the conveyed fibers engage and mechanically and frictionally interfere with the random fibers. The fibers may be conveyed from one aligned layer to the other for yet greater interference. The interfering fibers serve to secure and interlock the layers together, producing a one-piece reinforcement which, when impregnated with a polymer precursor, shaped and cured may be incorporated in a polymer reinforced composite article. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from Australian Provisional Patent Application No 2006904359 filed on 9 Aug. 2006, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to process control of an industrial plant. More particularly, the invention relates to a system for, and a method of, controlling an industrial plant particularly, but not necessarily exclusively, a smelting plant.
BACKGROUND TO THE INVENTION
[0003] The present demand for an increasingly rapid financial return in industrial plants such as smelting operations has driven operating parameters beyond their current performance limits. This has resulted in reduction in the lives of operating components of the plant, reduced operating efficiencies and reduction in product quality. The ever present need to reduce carbon and/or other greenhouse gas emissions is adding additional pressure to the situation. In the case of smelting operations, the control systems that are in use were implemented in the early 1980s whereas productivity, raw materials supply, energy price and environmental issues associated with the industry have intensified considerably since that time. Furthermore, the flexibility of pot line electricity usage is an increasingly important issue for smelters because of country and continental electricity grids and variation in availability and price which connection to such grids can impose.
[0004] Generally, control of processes has evolved in different ways depending on the type of system under consideration. The desire to maintain a process and its operating conditions at the optimum operating parameters for which it was designed, or subsequently retrofitted for the purpose of increased production and minimal capital investment, is a common requirement since these parameters determine the quality of the product and the efficiency and cost of the process. In an attempt to maintain operation at such optimum parameters, control systems have involved some form of compensatory control loop or feedback loop in order to maintain steady operating conditions for the industrial plant.
[0005] Thus, using a smelting operation as an example once again, a normal control strategy has fixed or specified operating targets for the key process variables associated with the smelting operation. These key variables are adjusted in a compensatory fashion using other control inputs. A problem with this approach is that this may produce greater variation over time and compound the initial causes of the variation. In fact, the initial causes of the variation may not be addressed at all due to the reliance on manipulation of control inputs not necessarily related to the cause, allowing the causes of the variation to remain embedded in the process and increase in number over time.
[0006] Further, in order to reduce complexity, assessment of the process condition in smelting cells has been characterised by a limited set of measurements performed, at different intervals, on each cell. The last data point for each routinely measured variable is usually the one used in assessment of cell state.
[0007] With the above arrangements, inadequate information is provided to enable comprehensive operational or automatic control of the smelting operation to be effected.
SUMMARY OF THE INVENTION
[0008] Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
[0009] According to a first aspect of the invention, there is provided a system for controlling an industrial plant, the system comprising:
[0010] automatic control equipment comprising a plurality of measurement sensors for sensing predetermined variables associated with components of the industrial plant, the sensors generating measured data relating to operation of the components of the industrial plant;
[0011] a database containing operational data, including observational data, regarding the industrial plant; and
[0012] a processor in communication with the automatic control equipment and the database for receiving the measured data from the sensors of the automatic control equipment and the operational data from the database, the processor manipulating the measured and the operational data to provide an evolving description of a process condition of each component over time, along with output information relating to operational control of the industrial plant and for updating the database.
[0013] The automatic control equipment may constitute a first system level, the processor and database constitute a second system level with the system including a third system level, being a management level. The management level may use the information output from the processor for effecting control of the industrial plant. The levels may be configured to achieve an improvement in a number of operating variables of the plant.
[0014] The system and method are intended particularly, but not necessarily exclusively, for use in an aluminium smelting operation. For ease of explanation, the invention will be described below with reference to this application. Those skilled in the art will, however, appreciate that the system and method are suitable for use in other applications. In particular, the method described here is generally applicable to any complex industrial process involving elements or sub-processes which interact in a non-linear and/or unpredictable way and in which the state of the industrial process has low observability for reasons of sensing or other difficulties, and low controllability because of the interactive nature of inputs and outputs and the varying and unpredictable time scales of their response to a control input.
[0015] A non-exhaustive list of industrial processes with the characteristics referred to above include: alumina refineries where a multiplicity of interacting caustic liquor circuits exist, each with a different dissolved sodium aluminate concentration and degree of super-saturation, and some streams with precipitating aluminium trihydroxide as well; steel plants where the iron ore thermal reduction step, iron to steel making furnaces and continuous casting processes are closely linked through steel temperature, composition and heat transfer from the transporting and holding vessels; steel or aluminium rolling and annealing/coating lines where coil gauge and width profiles are hard to measure a priori but have a profound effect on the heat transfer to the strip as it is annealed and the correct velocity of the strip through the annealing furnace for metallurgical quality.
[0016] In an aluminium smelting operation, the smelter contains a plurality of individual cells in which the smelting of aluminium oxide, or alumina, occurs. The cells of the smelting operation are arranged in lines, commonly referred to as pot lines. As indicated above, the system levels are provided to achieve improvements in a number of operational aspects of the smelting plant, more particularly, feed control to achieve good alumina dissolution; feed control to detect when good dissolution is not occurring and to correct this to inhibit periods of sludge accumulation; compositional control to maintain the mass of aluminium fluoride at an approximately constant level in a bath in each cell and to allow reduced compositional and temperature variation over time as alumina feed control and energy balance control are improved; energy balance control to maintain both sufficient superheat and actual bath temperature for alumina dissolution; energy balance control to inhibit periods of excessive superheat over time; statistical and causal analysis to continuously reduce variations across pot lines; and enterprise level management to assess actual pot line capabilities cell by cell to organise and prioritise improvement actions to improve smelter capability over time.
[0017] The system may be operable within a range for each variable, as determined by variability within the process, and may act to reduce variation within each variable and other key process variables through identifying abnormal or systemic, damaging patterns of variation which can be related to a single dominant cause.
[0018] The system may include a classifier module in communication with the processor for classifying variations of operating variables of the plant into one of a predetermined number of classes of variations. The classifier module may classify variations in a process variable into one of three classes being: common cause or natural variation, special cause variation or structural variation.
[0019] Common cause or natural variation may occur where no dominant cause is acting and a mix of causes results in a basically random pattern of variation. This class of variation may not be responded to automatically but may be the subject of process investigations if certain circumstances are present such as if the magnitude of the variation is still high or if there are safety implications.
[0020] Special cause variation may be one where a statistically significant, rarely encountered pattern of variation indicates that a dominant cause is influencing the process at any one time and that this cause is not part of the way the process is normally run. This class of variation may be signalled or alarmed by the automatic control equipment for investigation by operations staff. The operations staff may use the processor to determine the cause and, ideally, where possible, eliminate or correct the cause.
[0021] Structural variation may be one where non-random variation occurs often or routinely through the action of physical and chemical laws and the way the process is operated. Corrective automatic control actions may be possible if undesirable structural variations are detected by the sensors of the automatic control equipment. This may require identifying, or “finger printing”, the structural variation and observing corresponding changes in process condition over time.
[0022] In assessing the cell state, the present system may be operable to take into account information about the total process condition including process variable trajectory over a preceding period of time. In addition, when the plant is an aluminium smelting plant, the automatic control equipment may include bath superheat sensors, bath resistivity sensors, sensors for monitoring and noting electrical current variation and characteristic frequencies, cell off-gas temperature and flow rate sensors, and other control inputs such as the number of alumina shots fed to the cells in different feeding modes, for example, underfeed or overfeed modes and the degree of reduction in cell electrical resistance which occurs when such feeding modes are executed.
[0023] The observational data may relate to the operational state of the individual cells, the operational state being formally monitored and integrated into individual cell process conditions and including:-
anode condition including red carbon, airburnt anodes, red stubs, spikes, cracked anodes; bath condition including carbon dust, gap between bath and crust, bubble generation and location of evolution of the bubbles in the cell, bath level; metal level and the projected metal tap history; cover condition (remaining thickness and height on the anode connectors/stubs), crust damage, fume escape from superstructure; alumina and bath spillage on electrical conductors (rods, beams, bus bars); control action history over previous weeks including aluminium fluoride addition, alumina addition, extra voltage, excessive, unplanned anode beam movements, metals and bath transfers, etc; cathode condition including cathode voltage drop (CVD) history, collector bar current density, instability history, anode changing observations, anode effect frequency, etc; shell condition, including red plates, shell deformation and excessive heat rising to the catwalk from a certain shell location; hooding condition—gaps, damage, fitment, door and quarter shield sealing; bus bar and flexible damage, collector bars cut; lack of duct gas suction as observed through fume escape into the pot room; feeder operation, feeder chutes, feeder holes blocked, alumina not entering feeder holes; side wall ledge condition, silicon carbide mass loss, history of silicon level in metal; excessive liquid bath output from cells or from a pot room, indicating a change in heat balance causing melting of ledge, crust or dissolution of bottom sludge; iron level in metal which is an indicator of bath level and anode condition; trace elements in the metal which is indicative of trends in current efficiency over time; flame colour, including blue flames, lazy yellow flames (sludge), bright yellow (sodium) shooting flames which may indicate some anode to metal direct contact in a cell; and general housekeeping around each cell.
[0042] Each operational state may be monitored automatically by the sensors, using regular cell observations or both by the sensors and by observation, information obtained from the monitoring process being integrated with state variable measurements to build a description of the cell process condition of each individual cell and its evolution over time. It will be appreciated that in any industrial process there will be a set of equivalent observational data representative of the operational state of the process.
[0043] The processor and the database may be operable to check the process condition for each cell individually with the database being updated periodically. For example, the cell process condition may be updated at the commencement or termination of each shift.
[0044] The processor may include a causal framework for relating identified problems and cell process conditions to specific causes. The causal framework may form part of a learning algorithm of the processor which is improved and updated over time using data from the database, including feedback from staff about the validity of the causes identified and the effectiveness of corrective actions applied. This may also include conflicts which are observed and documented between the observational data and decisions and the numerical state information and automated decisions at level 1 of the control system. These updates may be subject to monthly review by management before becoming part of the knowledge base in the control system. Thus, the management level may employ causal trees containing the learning algorithm to provide a growing framework of decision support and, in the case of a smelting operation, cell diagnosis over time.
[0045] The database may have information associated with each cell and may contain process variable identifiers or “fingerprints” associated with specific problems, process events and/or cell process conditions.
[0046] The processor may further use a complexity measure to assess predictability of the process outcomes and the overall operation of the plant.
[0047] According to a second aspect of the invention, there is provided a method of controlling an industrial plant, the method comprising:
[0048] monitoring operation of the industrial plant by a plurality of sensors forming part of automatic control equipment;
[0049] transferring measured data from the sensors and observational (qualitative) data relating to operation of the industrial plant to a processor;
[0050] accessing a database containing operational data including data from the sensors and the observational data relating to operation of the industrial plant, as periodically updated by the processor; and
[0051] generating evolving process condition descriptions of each monitored component of the industrial plant and output information relating to operation of the industrial plant.
[0052] Thus, the method may include employing new formal control objectives based on the long term reduction in variability of the process, and on integrating human observation and decision making into the computational organisation of sensed information in traditional control systems.
[0053] The method may include forming three system levels, the automatic control equipment constituting a first system level, the processor and database constituting a second system level and a third system level being a management level. The method may include using the information output from the processor in the management level for effecting control of the industrial plant. The method may include configuring the levels to achieve an improvement in a number of operating variables of the plant.
[0054] The plant may be an aluminium smelting plant and the method may include configuring the levels to achieve improvements in a number of operational aspects of the plant. These operational aspects are generally not considered as part of the process condition of the industrial plant from a control viewpoint. More particularly, the operational aspects may include feed control to achieve desired alumina dissolution; feed control to reduce, and, if possible, eliminate, periods of sludge accumulation; compositional control to maintain the mass of aluminium fluoride at an approximately constant level in a bath in each cell and reduce compositional and temperature variation over time; energy balance control to maintain both sufficient superheat and actual bath temperature for alumina dissolution; energy balance control to inhibit periods of excessive superheat over time; statistical and causal analysis to continuously reduce variations across pot lines; and enterprise level management to assess actual pot line capabilities cell by cell to organise and prioritise improvement actions to improve capability over time and to optimise the production of metals with specifications matching sales orders.
[0055] The method may include operating the plant within a range for each variable as determined by variability within the process and which acts to reduce variation within each variable and other key process variables through identifying abnormal or systemic, damaging patterns of variation which can be related to a single dominant cause. Thus, the method may include correcting or minimising identified causes as appropriate, reducing the range of each process variable and improving process capability over time.
[0056] The method may include classifying variations of operating variables of the plant into one of a predetermined number of classes of variations. In particular, the method may include classifying variations in a process variable into one of three classes being: common cause or natural variation, special cause variation or structural variation.
[0057] The method may include taking into account information about the total process condition including process variable trajectory over a preceding period of time. The observational data may relate to the operational state of the individual cells, the method including formally monitoring and integrating the operational state into individual cell process conditions and the operational states including:-
anode condition including red carbon, airburnt anodes, red stubs, spikes, cracked anodes; bath condition including carbon dust, gap between bath and crust, bubble generation and location of evolution of the bubbles in the cell, bath level; metal level and the projected metal tap history; cover condition (remaining thickness and height on the anode connectors/stubs), crust damage, fume escape from superstructure; alumina and bath spillage on electrical conductors (rods, beams, bus bars); control action history over previous weeks including aluminium fluoride addition, alumina addition, extra voltage, excessive, unplanned anode beam movements, metals and bath transfers, etc; cathode condition including cathode voltage drop (CVD) history, collector bar current density, instability history, anode changing observations, anode effect frequency, etc; shell condition, including red plates, shell deformation and excessive heat rising to the catwalk from a certain shell location; hooding condition—gaps, damage, fitment, door and quarter shield sealing; bus bar and flexible damage, collector bars cut; lack of duct gas suction as observed through fume escape into the pot room; feeder operation, feeder chutes, feeder holes blocked, alumina not entering feeder holes; side wall ledge condition, silicon carbide mass loss, history of silicon level in metal; excessive liquid bath output from cells or from a pot room, indicating a change in heat balance causing melting of ledge, crust or dissolution of bottom sludge; iron level in metal which is an indicator of bath level and anode condition; trace elements in the metal which is indicative of trends in current efficiency over time; flame colour, including blue flames, lazy yellow flames (sludge), bright yellow (sodium) shooting flames which may indicate some anode to metal direct contact in a cell; and general housekeeping around each cell.
[0076] The method may further include monitoring each operational state automatically by the sensors, using regular cell observations or both by the sensors and by observation, information obtained from the monitoring process being integrated with state variable measurements to build a description of the cell process condition of each individual cell and its evolution over time.
[0077] The method may includes operating the processor and the database to check the process condition for each cell individually and updating the database periodically. For example, the cell process condition may be updated at the commencement or termination of each shift.
[0078] In addition, the method may include using a causal framework to relate identified problems and cell process conditions to specific causes. The method may include integrating the causal framework into a learning algorithm of the processor which is improved and updated over time using data from the database. Thus, the method may include employing causal trees containing the learning algorithm to provide a growing framework of decision support and, in the case of a smelting operation, cell diagnosis over time.
[0079] The database may have information associated with each cell and may contain process variable identifiers or “fingerprints” associated with specific problems, process events and/or cell process conditions.
[0080] The method may include using a complexity measure to assess predictability of the process outcomes and the overall operation of the plant.
[0081] According to a third aspect of the invention, there is provided a system for controlling an industrial plant, the system comprising:
[0082] automatic control equipment comprising a plurality of measurement sensors for sensing predetermined variables associated with components of the industrial plant;
[0083] a database containing operational data, including observational data, regarding the industrial plant; and
[0084] a processor in communication with the automatic control equipment and the database for receiving data from the sensors of the automatic control equipment and from the database, the processor using causal tree analysis comprising at least one continually updated learning algorithm to provide a framework of decision support and plant component diagnosis over time.
[0085] According to a fourth aspect of the invention, there is provided a method of controlling an industrial plant, the method comprising:
[0086] monitoring operation of the industrial plant by a plurality of sensors forming part of automatic control equipment;
[0087] transferring data from the sensors and observational data relating to operation of the industrial plant to a processor;
[0088] accessing a database containing operational data, including the data from the sensors and the observational data relating to operation of the industrial plant, as periodically updated by the processor; and
[0089] using causal tree analysis comprising at least one continually updated learning algorithm to provide a framework of decision support and plant component diagnosis over time.
[0090] According to a fifth aspect of the invention, there is provided automatic control equipment for a system for controlling an industrial plant, the system comprising:
[0091] a plurality of measurement sensors for sensing predetermined variables associated with components of the industrial plant;
[0092] a signal processing module responsive to the sensors and control input data; and
[0093] a classifier module in communication with the signal processing module, for classifying variations of operating variables of the plant, as detected by the sensors, into one of a predetermined number of classes of variations.
[0094] According to a sixth aspect of the invention, there is provided a method of operating an industrial plant, the method comprising:
[0095] monitoring operation of the industrial plant by a plurality of sensors;
[0096] processing data from the sensors and other control inputs; and
[0097] classifying variations of operating variables of the plant, as detected by the sensors, into one of a predetermined number of classes of variations.
[0098] According to a seventh aspect of the invention, there is provided a method of operating an industrial plant, the method comprising
[0099] monitoring operation of the industrial plant by a plurality of sensors forming part of automatic control equipment;
[0100] transferring measured data from the sensors and observational data relating to operation of the industrial plant to a processor;
[0101] accessing a database containing operational data, including the data from the sensors and the observational data relating to operation of the industrial plant, as periodically updated by the processor, to provide mechanisms to assist in identification and removal of causes of variations in the measured data; and
[0102] combining automatic control as carried out by the automatic control equipment with said mechanisms to provide continuous improvement in the operation of the plant.
[0103] According to an eighth aspect of the invention, there is provided a system for controlling an industrial plant, the system comprising:
[0104] automatic control equipment comprising a plurality of measurement sensors for sensing predetermined variables associated with components of the industrial plant;
[0105] a database containing operational data, including observational data, regarding the industrial plant; and
[0106] a processor in communication with the automatic control equipment and the database for receiving data from the sensors of the automatic control equipment and from the database, the processor using a complexity measure to assess predictability of the plant.
[0107] The use of the complexity measure may provide an early warning of a trend to more chaotic or less reliable operation of the plant (and/or the people in the plant) over time which will not otherwise be detected by the more repetitive, regular operation of control inputs and process outputs.
[0108] According to a ninth aspect of the invention, there is provided a method of controlling an industrial plant, the method comprising:
[0109] monitoring operation of the industrial plant by a plurality of sensors forming part of automatic control equipment;
[0110] feeding data from the sensors and observational data relating to operation of the industrial plant to a processor;
[0111] accessing a database containing operational data, including the data from the sensors and the observational data relating to operation of the industrial plant, as periodically updated by the processor; and
[0112] using a complexity measure to assess predictability of the plant.
[0113] The complexity measure may further alarm deteriorating trends in the reliability of the plant or elements of it (for example a particular part of a potline or a whole potline may start to behave less reliably than others in the same smelter).
BRIEF DESCRIPTION OF THE DRAWINGS
[0114] Embodiments of the invention are now described by way of example only with reference to the accompanying drawings in which:
[0115] FIG. 1 shows a schematic block diagram of a system, in accordance with an embodiment of the invention, for controlling an industrial plant;
[0116] FIG. 2 shows a tabular representation of the system of FIG. 1 ;
[0117] FIGS. 3-6 show a graphic representation of an example of the determination of state changes for a cell using a complexity measure;
[0118] FIG. 7 shows a tabular representation of a first control objective of the system;
[0119] FIG. 8 shows a tabular representation of a second control objective of the system;
[0120] FIG. 9 shows a tabular representation of a third control objective of the system;
[0121] FIG. 10 shows a tabular representation of a fourth and a fifth control objective of the system; and
[0122] FIG. 11 shows a tabular representation of a sixth control objective of the system.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0123] In FIG. 1 of the drawings reference numeral 10 generally designates a system, in accordance with an embodiment of the invention, for controlling an industrial plant. The plant is designated generally by the reference numeral 12 . The system 10 will be described with reference to its application to an aluminium smelting operation but it will be appreciated that the system 10 could be used in any industrial plant requiring control. The smelting operation or smelter 12 comprises a plurality of pot lines. Each pot line is constituted by a plurality of cells in which alumina is processed to form aluminium. Aluminium formed in the cells is tapped off periodically for casting or further processing downstream in the plant 12 .
[0124] The purpose of the system 10 is to minimize energy consumption and smelter emissions, maximize productivity and metal purity and promote a safer, healthier working environment over time by continuously reducing and removing variations in the process. The control objectives of the system 10 include:-
[0125] 1. Feed control to achieve conditions for good alumina dissolution for a high proportion of the operating time through identifying early signs of poor dissolution conditions and acting automatically if heat or composition related or through operational decisions and intervention if not able to be corrected automatically.
[0126] 2. Feed control to inhibit periods of sludge accumulation which are usually characterised by low alumina input during an underfeeding control mode and high alumina input during an overfeeding control mode and through this objective and objective 1 above jointly to minimize anode effects on all of the cells.
[0127] 3. Compositional control which maintains the mass of aluminium fluoride at an approximately constant level in the whole cell but also provides signals and mechanisms to correct the causes of aluminium fluoride mass variation within cells and pot lines, thereby improving the stability of aluminium fluoride concentration in the bath over time.
[0128] 4. Energy balance control which maintains both sufficient superheat and actual bath temperature for alumina dissolution and which inhibits large scale electrolyte freezing during normal cell operations such as anode setting, alumina feeding, metal level changes, or other additions to the cell.
[0129] 5. Energy balance control which minimises periods of excessive superheat over time by signalling when causes of excessive superheat are present and by giving decision support to cause identification and elimination.
[0130] 6. Continuous reduction in variation across the pot lines by categorising and finger printing sensor responses, integrating operational information with cell data histories and connecting the resulting cell process condition and identified process signals to proven causal trees. These causal trees contain a learning algorithm (as discussed below) and provide a growing framework of decision support and cell diagnosis over months and years of operation of the industrial process.
[0131] 7. Enterprise level management which assesses actual pot line capability cell by cell and includes carbon plant and casthouse capabilities to organise and prioritise improvement actions over time. The system builds levels of planning information for future years based on cell and pot line constraints and tested solutions to result in maximized production, capture of higher purity metal and satisfying sales order metal specifications (through bath level, anode airburn and bath temperature variability reduction and linkage to the casthouse metal batch and furnace capture). It also matches anode capability and cell capability across their respective populations to reduce anode/cell adverse interactions over time.
[0132] The above objectives are achieved through a three step control model of, firstly, observing the process, secondly, understanding the variation and, thirdly, controlling the outcome. Particular emphasis is placed on the multivariate nature and non-linearity of the system 10 . The system 10 is implemented within an architecture which systemizes observation of total process condition in the first control step, learning through a causal framework associated with the second control step and a human decision guidance module associated with the third control step.
[0133] The system 10 includes automatic control equipment 14 . The automatic control equipment 14 comprises a plurality of sensors 16 for monitoring operating variables associated with the smelter 12 . The automatic control equipment 14 and the sensors 16 constitute a first level of the system 10 .
[0134] A second level of the system 10 comprises a processor 18 which communicates with the automatic control equipment 14 . The processor 18 is further in communication with a database 20 in which operational data relating to the cells of the smelter 12 are stored. In addition to the sensor and routine numerical measurements, the database 20 contains data relating to problems and process variable identifiers or “fingerprints” associated with specific problems or events related to each cell of the smelter 12 . These data are derived from the sensors 16 as well as qualitative observational data as detected by operations staff, as illustrated schematically at 22 , which is input into the database via the processor 18 .
[0135] A third level of the system 10 is a management level 24 which uses data from the database 20 to control and improve operation of the smelter 12 , as will be described in greater detail below.
[0136] A tabular arrangement of the system 10 is shown in FIG. 2 of the drawings. The automatic control equipment 14 , as indicated above, communicates with the sensors 16 . These sensors 16 , in turn, feed to a plurality of monitoring modules. Hence, the automatic control equipment 14 comprises an abnormal raw resistance monitor 26 for monitoring a rapidly acquired cell resistance signal and detecting patterns and frequencies indicative of abnormal operation. Together with alarming of cathode and anode abnormalities, the resistance monitor 26 is used in combination with a feed monitor module 28 which monitors the response of the individual cell resistances of the smelter 12 to the feeding of alumina at different rates corresponding to the different feed control modes.
[0137] A temperature/liquidus control module 30 also communicates with the feed monitor module 28 and with the raw resistance monitor 26 . This module 30 monitors changes in temperature, liquidus temperature and bath resistance per millimetre of anode beam movement (if these sensors are active) and also includes an alumina concentration dimension computed with reference to the feed monitor module 28 .
[0138] The automatic control equipment 14 further includes a signal processing module 32 which receives signals from all of the sensors 16 and other control inputs. It summarises the essential character (mean, range, trend, frequency) of these signals and controls the supply of the resulting information to the processor 18 of the system 10 .
[0139] The operating variables of the smelter 12 are classified in three classes, as will be described in greater detail below. To enable this to occur, the automatic control equipment 14 includes a classifier module 34 . This classifier module 34 classifies variations into one of the three classes. In addition, the classifier module 34 classifies the cells of the pot line.
[0140] In level two of the system 10 , the processor 18 includes a cell process condition module 36 which communicates with the database 20 for maintaining a history of state variables, operational observations and non-conformances of both as well as cell process complexity trends (which can show process state changes) for all cells. The cell process condition is tracked daily, weekly and monthly. Short and longer term aspects of the cell process condition are determined and updated periodically, for example, at the commencement or termination of each shift, weekly and/or monthly.
[0141] The cell process complexity trends are used to determine aspects of the cell state which are not evident from the normal physical measurements of process variables. Predictability of the system 10 is assessed using a complexity/information measure referred to as T-entropy. Briefly, T-entropy is an algorithmic technique which allows computation of the complexity of a finite string of characters which are produced by symbolically transforming information from visual and other analogue or digital signals. (A complete treatment of the derivation of T-entropy can be obtained from the following reference: Titchener, M. R., Gulliver, A., Nicolescu, R., Speidel, U. and Staiger, L. (2005) Deterministic Complexity and Entropy . Fundamenta Informaticae, 64(1-4), 443-61.)
[0142] T-entropy is analogous to its thermodynamic equivalent which is most commonly referred to as the ‘level of disorder’ in a (chemical) system. Similarly, T-entropy evaluates the level of disorder in a finite, two-dimensional signal. T-entropy contains information which is not provided in traditional signal processing, where the repetitive, regular frequency characteristics of a signal are determined. The non-repetitive, chaotic or non-linear elements of signals in real world problems contain more information however. It is this complex, real world behaviour which is transduced through the T-entropy computation.
[0143] Using the example of a pseudo-resistance trace from a pre-bake operating cell with metal pad noise developing over a period of four hours, FIG. 3 exemplifies the computation of T-entropy. In FIG. 3 , an entropy surface 52 and its maximum entropy 54 for pseudo-resistance trace 56 is illustrated.
[0144] In FIG. 4 , the maximum entropy 54 , an integral under the curve, or raster, 58 and a three-dimensional hybrid trace 60 are illustrated. Another “view” of this (in a z-y plane) is shown in FIG. 5 of the drawings. This shows areas of density in the hybrid trace 60 . The two areas of density are shown at 62 and 64 with the transition between them shown at 66 . The three clusters 62 - 66 indicate three distinct states of the process with state changes associated with physical changes inside the cell which it is not possible to detect routinely by other sensors and methods.
[0145] The three clusters or states 62 - 66 identified in FIG. 5 are plotted against time as a trace 68 together with the T-entropy output 52 and the pseudo-resistance output 56 as shown in FIG. 6 . This state information 68 would not have been obtainable from the pseudo-resistance trace 56 alone and provides information concerning changes in the complexity of the cell behaviour. The information provided by the trace 68 is integrated into the cell process condition module 36 and is made available to the operational staff of the plant to enable analysis and remedial action, if necessary, to be undertaken.
[0146] The processor 18 makes use of a learning algorithm 38 for causal tree analysis. The learning algorithm comprises a causal framework 39 ( FIG. 11 ) for the pot line of the smelter 12 and relates identified problems and cell process conditions to specific causes. The processor 18 therefore communicates with the database 20 and under management authorisation the new causal/cell condition links and corrective actions are added to the framework so that the causal framework is improved and updated over time to render the learning algorithm 38 more applicable to prevailing circumstances. Operational staff at the plant provide feedback concerning the success of causal analysis and recommendations into the processor 18 to integrate the practical aspect of plant operation and to improve future control system actions.
[0147] The management level 24 includes an assessment module 40 . The assessment module 40 assesses pot line efficiency and production capability on a cell by cell basis, taking note of the incidence and severity of variations occurring in two of the classes, i.e. special cause variation and structural cause variation.
[0148] Additionally, the management level 24 comprises an analysis module 42 for effecting planning options analysis based on potential capability improvement and calculated risk over a period of time.
[0149] As indicated above, the classification module 34 classifies variations in each variable into one of three classes. These three classes are:-
[0150] common cause or natural variation, special cause variation and structural cause variation.
[0151] Common cause or natural variation is a variation where no dominant cause is acting and the mix of causes results in a basically random pattern of variation. This class of variation is not responded to automatically but may be the subject of process investigations if the magnitude of the variation is too high or has safety implications.
[0152] Special cause variation is one where a statistically significant, rarely encountered pattern of variation indicates that a dominant cause is influencing the process at that particular time and that this cause is not part of the way the process is normally run. This class of variation is detected by the sensors 16 of the automatic control equipment 14 and/or through the systematic observations of staff at the cells during routine daily operations and is investigated by the operations staff 22 . The staff 22 use the causal tree analysis of the processor 18 to determine and, if possible, eliminate the cause.
[0153] Structural variation occurs where non-random variation takes place often or routinely through the action of physical and chemical laws and the way the process is operated. Automatic corrective action is possible if undesirable structural variation is detected in the cell sensors 16 . This requires access to the database to determine established connections between the cell sensor responses, causes of variation and control objectives of the system 10 . This is achieved through finger printing the structural variations and observing corresponding changes in the process condition over time.
[0154] Insofar as the first step of observing the process is concerned, the control strategy of the system 10 does not rely solely on fixed or specified operating targets for the key process variables such as bath temperature, bath composition, and cell voltage. Rather, the control strategy operates over a range of process variables determined by variability within the process itself to produce a target cell process condition related to the desired process outcomes (for example energy efficiency, metal purity, anode effects, cell life, cost of production and safety). The control strategy acts to reduce variation in the range of these key process variables through identifying abnormal or systemic, damaging patterns of variations which can be related to a single dominant cause at a given point in time. The identified causes can then be corrected or eliminated as appropriate reducing the range of each process variable and improving the process capability over time. Thus, the system uses, in addition to the existing cell sensors 16 , new cell sensors such as bath superheat sensors, bath resistivity sensors, sensors for monitoring anode current variation at characteristic frequencies, cell off-gas temperature and flow rate sensors and other control inputs.
[0155] In addition, observational data as detected by the operation staff 22 include monitoring the operational state of the cells by monitoring of the following:
anode condition including red carbon, airburnt anodes, red stubs, spikes, cracked anodes; bath condition including carbon dust, gap between bath and crust, bubble generation and location of evolution of the bubbles in the cell, bath level; metal level and the projected metal tap history; cover condition (remaining thickness and height on the anode connectors/stubs), crust damage, fume escape from superstructure; alumina and bath spillage on electrical conductors (rods, beams, bus bars); control action history over previous weeks including aluminium fluoride addition, alumina addition, extra voltage, excessive, unplanned anode beam movements, metals and bath transfers, etc; cathode condition including cathode voltage drop (CVD) history, collector bar current density, instability history, anode changing observations, anode effect frequency, etc; shell condition, including redylates, shell deformation and excessive heat rising to the catwalk from a certain shell location; hooding condition—gaps, damage, fitment, door and quarter shield sealing; bus bar and flexible damage, collector bars cut; lack of duct gas suction as observed through fume escape into the pot room; feeder operation, feeder chutes, feeder holes blocked, alumina not entering feeder holes; side wall ledge condition, silicon carbide mass loss, history of silicon level in metal; excessive liquid bath output from cells or from a pot room, indicating a change in heat balance causing melting of ledge, crust or dissolution of bottom sludge; iron level in metal which is an indicator of bath level and anode condition; trace elements in the metal which is indicative of trends in current efficiency over time; flame colour, including blue flames, lazy yellow flames (sludge), bright yellow (sodium) shooting flames which may indicate some anode to metal direct contact in a cell; and general housekeeping around each cell.
[0174] The cell process condition elements monitored above can be monitored either by the operations staff 22 or by the sensors 16 . This information is integrated with state variable measurements to build a description of the total process condition of each individual cell and its evolution over time.
[0175] The cell process condition for each cell is tracked individually by the processor 18 and is updated periodically, for example, at the commencement or termination of each shift. The process condition description is also used in the automatic control equipment 14 and may be used for operational decisions during any shift for individual cells or for the pot line. The process condition is also used for process engineering investigations to correct individual cells manifesting long term problems and, finally, is used by the management level 24 which uses pot line condition for judging the capability of the smelter 12 to alter its operating settings, for example, production rate or energy usage.
[0176] As indicated above, understanding the variation in the operating variables comprises classifying these variations in one of the three classes.
[0177] The third step of the control system 10 is achieved by altering the traditional function of each level of the system 10 so that the new control objectives set out above are met. Insofar as the first level is concerned, the control system 10 seeks to achieve a systematic reduction in individual cell variations through corrective control of variables such as alumina feed, bath composition and energy input and relies on the integration of operator observations of cell condition and their subsequent well informed decisions and actions to remove causes of these variations.
[0178] The second level of the system 10 seeks to achieve pot line variation reduction through removal of causes of the variations. It further relies on pot line management which emphasises decision making using the database framework of variation and causes which is continually updated with evidence accumulating over time and is systematically linked to the operational observations and practical decision making so that contradictions between theoretical control decisions and direct observation are constantly being sought and resolved. It also facilitates individual cell process condition description and tracking using T-entropy trends to identify hidden state and state change information. This level also uses human decision guidance linking physical cell condition stimuli to detection and decision making.
[0179] The management level 24 of the system 10 is used to effect pot line capability assessment based on cell state, metal purity distribution data from the second level and quantified improvement potential. The cell distribution data is linked to improvement strategies such as reducing poorly performing cells or moving the entire cell distribution, as well as metal marketing and financial planning and control.
[0180] FIG. 7 shows a tabular implementation of the first control objective for achieving good alumina dissolution. The module letters correspond to the module labels in FIG. 2 of the drawings.
[0181] Similarly, FIG. 8 shows a tabular representation of the second control objective of elimination of periods of sludge accumulation without incurring anode effects. As is the case with the first control objective, the second control objective relies on operational observations triggered automatically by sensing and level 1 control logic to indicate specific observations (concerning the alumina feeders primarily) required to achieve the control objectives.
[0182] FIG. 9 shows a tabular representation of the third control objective of compositional control based on achieving near constant mass of aluminium fluoride in each cell and its improvement over time. In this control objective, there is, once again, a requirement for observational data and also operator input for adjustment of the cell or line, particularly in the case where the variation is identified as being special cause. The identification of adverse structural variation such as thermal and compositional cycling allows these to be related to the systemic causes embedded in the control system and the smelter 12 itself through the learning algorithm 38 at level 2 in the control system.
[0183] FIG. 10 is a combination of control objectives 4 and 5 to achieve energy balance control to maintain changes in temperature within a range which can be withstood by the cell without damage to the process.
[0184] In the case of control objective 6, this control objective is met substantially at level 2 of the system 10 and is shown diagrammatically in FIG. 11 . Because the system design is now specifically aimed at improvement and not only control, the architecture of the level 2 system differs from previous supervisory systems.
[0185] Better understanding of what constitutes the cell process condition now enables a single screen view of the state of each cell of the smelter 12 and incorporates both state variable measurement and operational state attributes as well as the respective histories. One embodiment of this view is shown in the first part of FIG. 11 . Each variable or attribute is described by a colour being red (R), orange (O), blue (B), or green (G) representing not only the last observation but also the stability of the observations over a specified operating period and within the stable, multi-dimensional control volume for selected groups of variables. Red and orange status indicates abnormal status conditions requiring attention and potential abnormality respectively.
[0186] Taking the example of “Alumina kg/d” the stability of the uni-variate measurement will be judged by the statistical stability of the cusum of the “Alumina Daily addition. The capability of the cell with respect to “Alumina Feeding” will be judged by the flatness of the Cusum Chart. In other words: “Is the cell consumption of alumina matched to the metal production rate?” However, this variable is also combined into multivariate views of the whole cell process condition because of its interaction with the thermal arid compositional balance. In this example of alumina feeding, kg/d of alumina fed during an underfeed mode and kg/d of alumina fed during an overfeed mode can be analysed as a bi-variate surface, leading to a state descriptor for feeding, as one element of the overall cell process condition.
[0187] The database 20 contains the normal comprehensive numerical information over time, but with new classes of discontinuous, cell specific information as shown in FIG. 11 . This “event driven” data is stored in time stamped flat files and is used along with process variable fingerprints stored in the database to establish likely causes within the causal framework 39 .
[0188] The causal framework 39 is largely automated in its data queries and logic processing. It is designed to respond to management requirements in two ways by, firstly, providing causes and corrective actions for individual problems through request at any time. These requests can also be automated at a start of a shift through the cell process condition module 44 , if required.
[0189] The causal framework 39 , secondly, provides timed (daily, weekly, monthly) review reports to people within the organisation. These reports are configurable and summarise problems requested, those resolved and those with adverse consequences stemming from the advice provided, learning opportunities formulated (for authorisation) and conflicts between causal logic and observations (for resolution). This is provided on a human decision guidance module 46 .
[0190] The causal framework 39 drives improvements in control and in performance on the pot line by use of the enhanced database 20 and process condition descriptions to solve single cell and systemic pot line problems.
[0191] The presentation of summary data on the number of problems outstanding on the number of cells in various states of control is a stimulus for management attention and is facilitated by having a continuous tracker 48 of both cell process condition and identified cell problems. The tracker 48 aids in operational implementation of cell action plans as shown at 50 .
[0192] The tracker 48 plays an integral part of the management process embedded in level 2 of the system 10 . Decisions are based on the scientifically formulated and evidentially confirmed causal framework 39 , the diagnosed cell process condition and the computed trend in the complexity or chaotic nature of the cell condition using T-entropy.
[0193] The control objective 7 relies on achievement over time of the first six control objectives. It also requires that the measured and predicted future capability of the pot line is formally integrated into financial management and planning processes for the smelter 12 . This is achieved by the modules 40 and 42 of the management level 24 . The actual design of the modules 40 and 42 will depend on the enterprise level system which is in use at the smelter 12 .
[0194] It is therefore an advantage of the invention that an improved system 10 is provided which enables more accurate control of a smelter 12 to be achieved over a period of time by the use of observational data, a causal framework 39 and automatic control equipment 14 which is more integrated with the formal control objectives and with the observations of the staff. With the new system, reduction in variation in individual cells through integrated automatic and operational control decisions can be achieved over a period of time resulting, in the long run, in improved operating efficiencies of the smelter 12 .
[0195] A further advantage of the system 10 is that it achieves integration of energy, composition, alumina feed and operational controls with smelter improvement plans to minimise energy consumption and smelter emissions and to maximise production of metal of the highest possible purity/value over time. Still further, it facilitates a holistic assessment of the process condition of each individual cell, the process condition of each cell being maintained and updated over time.
[0196] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. In particular, while the system and method have been described with reference to its application in an aluminium smelting plant, that has been done for ease of explanation only. The system and method are equally applicable in any industrial process where a set of equivalent observational data representative of the operational state of the process can be employed in improving the operation of the process. | A system ( 10 ) for controlling an industrial plant ( 12 ) comprises automatic control equipment ( 14 ) comprising a plurality of measurement sensors ( 16 ) for sensing predetermined variables associated with components of the industrial plant ( 12 ). The sensors ( 16 ) generate measured data relating to operation of the components of the industrial plant ( 12 ). A database ( 20 ) contains operational data, including observational data, regarding the industrial plant ( 12 ). A processor ( 18 ) is in communication with the automatic control equipment ( 14 ) and the database ( 20 ) for receiving the measured data from the sensors ( 16 ) of the automatic control equipment ( 14 ) and the operational data from the database ( 20 ). The processor ( 18 ) manipulates the measured and operational data to provide an evolving description of a process condition of each component over time, along with output information relating to operational control of the industrial plant ( 12 ) and for updating the database ( 20 ). | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of pending U.S. patent application Ser. No. 13/439,686 filed Apr. 4, 2012, entitled “Methods and Apparatus for Efficient Transport and Management of a Positioning & Timing Almanac,” which is assigned to the assignee hereof and hereby incorporated by reference in its entirety.
BACKGROUND
[0002] 1. Field
[0003] The present disclosure relates generally to communication systems, and more particularly, to methods and apparatus for efficient transport and management of a positioning and timing almanac at mobile stations supported by a positioning assistance server.
[0004] 2. Background
[0005] Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, and so on. These systems may be multiple-access systems capable of supporting communications with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA), 3GPP Long Term Evolution (LTE) systems, and orthogonal frequency division multiple access (OFDMA) systems.
[0006] Generally, a wireless multiple-access communication system may simultaneously support communication for multiple wireless terminals. Each terminal communicates with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. This communication link may be established via a single-in-single-out, multiple-in-single-out or a multiple-in-multiple-out (MIMO) system. The method and apparatus described herein may be used with a conventional wireless system or with a MIMO system.
[0007] A MIMO system employs multiple (N T ) transmit antennas and multiple (N R ) receive antennas for data transmission. A MIMO channel formed by the N T transmit and N R receive antennas may be decomposed into N S independent channels, where N S ≧min {N T , N R }. Each of the N S independent channels corresponds to a dimension. The MIMO system may provide improved performance (e.g., higher throughput and/or greater reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.
[0008] A MIMO system may support time division duplex (TDD) and/or frequency division duplex (FDD) systems. In a TDD system, the forward and reverse link transmissions are on the same frequency region so that the reciprocity principle allows the estimation of the forward link channel from the reverse link channel. This enables the base station to extract transmit beamforming gain on the forward link when the multiple antennas are available at the base station. In an FDD system, forward and reverse link transmissions are on different frequency regions.
[0009] As mobile stations have become more capable with more features provided use and reliance on those features has grown. One such feature is position location, commonly known as global positioning systems (GPS). Most users are familiar with GPS systems and have used them for locating points of interest or for obtaining directions. Terrestrial radio resources (e.g., cellular base stations, TV broadcasting, FM/AM radio signals and WiFi access points) are more widely used for positioning now because of increased availability for mobile stations. In order to take advantage of these communication receivers for positioning, additional information must be delivered to a mobile station for use with mobile based positioning.
[0010] The information package, often known as an almanac, grows quickly in size as it covers larger areas of transceivers with descriptions of their location, coverage, and clock calibration data. It is important to deliver the almanac efficiently with minimum cost. There is a need in the art for efficient almanac delivery and maintenance to reduce unnecessary transmissions between mobile stations and the server.
SUMMARY
[0011] Embodiments disclosed herein provide a method for almanac version control. The method comprises reporting almanac versions and almanac identification by a mobile station to a server. The mobile then receives instructions from the server to match the server versions of the almanac versions and almanac identifications held by the server for the almanac versions and almanac identifications that the mobile station should hold.
[0012] A further embodiment provides a method for selective downloading of almanac versions. The server receives almanac identifications and almanac versions from at least one mobile station. The server then compares the almanac versions and almanac identifications sent the by the at least one mobile station with the almanac versions and almanac identifications held by the server. The server then sends instructions to the mobile station to match the server versions of the almanac versions and almanac identifications for the almanac versions and identifications that the at least one mobile station should hold.
[0013] A still further embodiment provides a method for almanac version control. The method begins when a server generates a partition based on a privilege setting. The server then receives a request from at least one mobile station for almanac versions based on at least one of a latest version, a relevant version, and the privilege setting. The server then compares the server's almanac versions with the versions requested by the mobile station. The requested almanac is then sent to the mobile station.
[0014] A yet further embodiment provides a method for selective downloading of almanac versions. The method comprises the steps of: requesting, by a mobile station, almanac versions based on at least one of a latest version, a relevant version, and a privilege setting. The mobile stations then receive the requested version from the server and updates the version held by the mobile station.
[0015] An apparatus for almanac version control is provided in a further embodiment. The apparatus comprises: a server containing a database, wherein the server acts in conjunction with a processor for data aggregation and a processor for comparison. A release database and a partition database acting in conjunction with a partition manager processor. The apparatus also includes a processor for checking for reorganization flags and for comparing almanacs for version changes. A process then determines the existing partition organization and compares the existing partitions with the predetermined threshold size.
[0016] A still further embodiment provides: means for reporting almanac version and almanac identification by a mobile station to a server; means for receiving instructions from a server to match the server versions of the almanac versions and almanac identifications that the mobile station should hold.
[0017] Yet a further embodiment provides an apparatus for selecting downloading of almanac versions. The apparatus provides: means for requesting almanac versions based on at least one of a latest version, a relevant version, and a privilege setting; means for receiving the almanac version requested; and means for updating the requested version.
[0018] An additional embodiment provides a machine readable non-transitory computer readable medium comprising instructions, which when executed by a processor cause the processor to perform the steps of: reporting almanac versions and almanac identifications by a mobile station to a server; and receiving instructions from a server to match the server versions of the almanac version and almanac identifications held by the server for the almanac versions and almanac identifications that the mobile station should hold. A still further embodiment provides a machine readable non-transitory computer readable medium comprising instructions, which when executed by a processor cause the processor to perform the steps of: receiving almanac versions and almanac identifications from at least one mobile station; comparing the almanac versions and almanac identifications sent by the at least one mobile station with almanac versions and almanac identifications held by the server; and sending instructions to the mobile station to match the server version of the almanac versions and almanac identifications for the almanac version and identification that the at least one mobile station should hold.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 illustrates a multiple access wireless communication system, in accordance with certain embodiments of the disclosure.
[0020] FIG. 2 illustrates a block diagram of a communication system in accordance with certain embodiments of the disclosure.
[0021] FIG. 3 is a diagram illustrating PTA system architecture.
[0022] FIG. 4 illustrates the PTA revision process—coordination of data aggregation engine and partition manager.
[0023] FIG. 5 depicts examples of PTA revision triggering events.
DETAILED DESCRIPTION
[0024] Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident; however, that such aspect(s) may be practiced without these specific details.
[0025] As used in this application, the terms “component,” “module,” “system” and the like are intended to include a computer-related entity, such as, but not limited to hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets, such as data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal.
[0026] Furthermore, various aspects are described herein in connection with a terminal, which can be a wired terminal or a wireless terminal. A terminal can also be called a system, device, subscriber unit, subscriber station, mobile station, mobile, mobile device, remote station, remote terminal, access terminal, user terminal, communication device, user agent, user device, or user equipment (UE). A wireless terminal may be a cellular telephone, a satellite phone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having wireless connection capability, a computing device, or other processing devices connected to a wireless modem. Moreover, various aspects are described herein in connection with a base station. A base station may be utilized for communicating with wireless terminal(s) and may also be referred to as an access point, a Node B, or some other terminology.
[0027] Moreover, the term “or” is intended to man an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form.
[0028] The techniques described herein may be used for various wireless communication networks such as Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, Single-Carrier FDMA (SC-FDMA) networks, etc. The terms “networks” and “systems” are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes Wideband CDMA (W-CDMA). CDMA2000 covers IS-2000, IS-95 and technology such as Global System for Mobile Communication (GSM).
[0029] An OFDMA network may implement a radio technology such as Evolved UTRA (E-UTRA), the Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, Flash-OFDAM®, etc. UTRA, E-UTRA, and GSM are part of Universal Mobile Telecommunication System (UMTS). Long Term Evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS, and LTE are described in documents from an organization named “3 rd Generation Partnership Project” (3GPP). CDMA2000 is described in documents from an organization named “3 rd Generation Partnership Project 2” (3GPP2). These various radio technologies and standards are known in the art. For clarity, certain aspects of the techniques are described below for LTE, and LTE terminology is used in much of the description below. It should be noted that the LTE terminology is used by way of illustration and the scope of the disclosure is not limited to LTE. Rather, the techniques described herein may be utilized in various application involving wireless transmissions, such as personal area networks (PANs), body area networks (BANs), location, Bluetooth, GPS, UWB, RFID, and the like. Further, the techniques may also be utilized in wired systems, such as cable modems, fiber-based systems, and the like.
[0030] Single carrier frequency division multiple access (SC-FDMA), which utilizes single carrier modulation and frequency domain equalization has similar performance and essentially the same overall complexity as those of an OFDMA system. SC-FDMA signal may have lower peak-to-average power ration (PAPR) because of its inherent single carrier structure. SC-FDMA may be used in the uplink communications where the lower PAPR greatly benefits the mobile terminal in terms of transmit power efficiency.
[0031] FIG. 1 illustrates a multiple access wireless communication system 100 according to one aspect. An access point 102 (AP) may include multiple antenna groups, one including 104 and 106 , another including 108 and 110 , and an additional one including 112 and 114 . In FIG. 1 , only two antennas are shown for each antenna group, however, more or fewer antennas may be utilized for each antenna group. Access terminal 116 (AT) is in communication with antennas 112 and 114 , where antennas 112 and 114 transmit information to access terminal 116 over downlink or forward link 118 and receive information from access terminal 116 over uplink or reverse link 120 . Access terminal 122 is in communication with antennas 106 and 108 , where antennas 106 and 108 transmit information to access terminal 122 over downlink or forward link 124 and receive information from access terminal 122 over uplink or reverse link 126 . In a Frequency Division Duplex (FDD) system, communication links 118 , 120 , 124 , and 126 may use a different frequency for communication. For example, downlink or forward link 118 may use a different frequency than that used by uplink or reverse link 120 .
[0032] Each group of antennas and/or the area in which they are designed to communicate is often referred to as a sector of the access point. In an aspect, antenna groups each are designed to communicate to access terminals in a sector of the areas covered by access point 102 .
[0033] In communication over downlinks or forward links 118 and 124 , the transmitting antennas of access point may utilize beamforming in order to improve the signal-to-noise ratio (SNR) of downlinks or forward links for the different access terminals 116 and 122 . Also, an access point using beamforming to transmit to access terminals scattered randomly through its coverage causes less interference to access terminals in neighboring cells than an access point transmitting through a single antenna to all its access terminals.
[0034] An access point may be a fixed station used for communicating with the terminals and may also be referred to as a Node B, an evolved Node B (eNB), or some other terminology. An access terminal may also be called a mobile station, UE, a wireless communication device, terminal, or some other terminology. For certain aspects, either the AP 102 , or the access terminals 116 , 122 may utilize the proposed Tx-echo cancellation technique to improve performance of the system.
[0035] FIG. 2 is a block diagram of an aspect of a transmitter system 210 and a receiver system 250 in a MIMO system 200 . At the transmitter system 210 , traffic data for a number of data streams is provided from a data source 212 to a transmit (TX) data processor 214 . An embodiment of the disclosure may also be applicable to a wireline (wired) equivalent of the system shown in FIG. 2 .
[0036] In an aspect, each data stream is transmitted over a respective transmit antenna. TX data processor 214 formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provided coded data.
[0037] The coded data for each data stream may be multiplexed with pilot data using OFDM techniques. The pilot data is typically a known data pattern that is processed in a known manner and may be used at the receiver system to estimate the channel response. The multiplexed pilot and coded data for each data stream is then modulated (e.g., symbol mapped) based on a particular based on a particular modulation scheme (e.g. a Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), M-PSK in which M may be a power of two, or M-QAM, (Quadrature Amplitude Modulation)) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream may be determined by instructions performed by processor 230 that may be coupled with a memory 232 .
[0038] The modulation symbols for all data streams are then provided to a TX MIMO processor 220 , which may further process the modulation symbols (e.g., for OFDM). TX MIMO processor 220 then provides N T modulation symbol streams to N T transmitters (TMTR) 222 a through 222 t . In certain aspects TX MIMO processor 220 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.
[0039] Each transmitter 222 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel N T modulated signals from transmitters 222 a through 222 t are then transmitted from N T antennas 224 a through 224 t , respectively.
[0040] At receiver system 250 , the transmitted modulated signals are received by the N R antennas 252 a through 252 r and the received signal from each antenna 252 is provided to a respective receiver (RCVR) 254 a through 254 r . each receiver 254 conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding “received” symbol stream.
[0041] An RX data processor 260 then receives and processes the N R received symbol streams from N R receivers 254 based on a particular receiver processing technique to provide N T “detected” symbol streams. The RX data processor 260 then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by RX processor 260 is complementary to that performed by TX MIMO processor 220 and TX data processor 214 at transmitter system 210 .
[0042] Processor 270 , coupled to memory 272 , formulates a reverse link message. The reverse link message may comprise various types of information regarding the communication link and/or the received data stream. The reverse link message is then processed by a TX data processor 238 , which also receives traffic data for a number of data streams from data source 236 , modulated by a modulator 280 , conditioned by transmitters 254 a through 254 r , and transmitted back to transmitter system 210 .
[0043] At transmitter system 210 , the modulated signals from receiver system 250 are received by antennas 224 , conditioned by receivers 222 , demodulated by a demodulator 240 and processed by a RX data processor 242 to extract the reserve link message transmitted by the receiver system 250 .
[0044] Methods and apparatuses are provided that support efficient transport and management of a terrestrial radio resource almanac at mobile stations supported by a navigation assistance server.
[0045] Almanac version control is designed to minimize frequent unnecessary revisions of the almanac and the resulting data transactions between the mobile station and the server. Changes on each almanac partition as closely watched and selectively updated and distributed depending on their significance. The proposed almanac version control mechanism minimizes mobile downloading traffic and time by reducing any unnecessary revisions of the almanac.
[0046] The server prioritizes the almanac partitions to be downloaded and recommends their simple and efficient management at a mobile station. The partition selection is intended to provide a locally optimized set of partitions that are most relevant to the mobile station's current location. The partition management recommendations reduce the burden of partition management at a mobile station while preserving the mobile's right to keep the partitions it deems relevant and important. The proposed server intelligent almanac selection minimizes mobile downloading traffic and time by enhancing the relevance of the downloaded almanac to the current user's context based on mobile current or past context (e.g., current or past location, and the current or past list of partitions.)
[0047] Assistance data around cellular networks (e.g., BSA, SNA, and others) is used to illustrate the operation of the apparatus described herein, however, the methods and apparatus may be used in conjunction with any terrestrial radio source as well as any general positioning, timing, or contextual assistance information provided from a server to a mobile device to enhance the user's position or timing experience.
[0048] The almanac version control mechanism described herein minimizes mobile downloading traffic and time by reducing unnecessary almanac revisions. In addition, the proposed selective downloading protects the privacy and privilege of entities, (e.g., a wireless carrier, building owner, institution, or others) by enabling selective almanac downloading according to the given mobile station′ privilege settings and the given almanac downloading permission settings. The proposed multi-layered mobile memory space enables a mobile to benefit from both public assistance almanacs and personalized mobile history (e.g., frequently visited places) as well as multiple memory spaces on mobiles with different speeds and sizes.
[0049] FIG. 3 provides an overview of the context of the positioning and timing assistance (PTA) system, which includes PTA servers and PTA clients. The position and timing assistance (PTA) system 300 provides position and timing assistance to mobile stations or PTA clients 324 to enhance positioning operations. Position and timing assistance includes positioning assistance information such as terrestrial radio transmitter location, power level, expected range or coverage, timing/frequency bias and stability as well as data for the navigation satellites. A mobile or PTA client 324 uses the position and timing assistance to find the assistance information for the user's current positioning activity. For example, when a cellular base station is observed, the mobile station may use the location of the base station instantaneously if the base station is included in position and timing assistance in the mobile station's memory as a seed location to initialize the positioning calculation. This saves time and resources since the mobile station does not need to wait for assistance from a remote server.
[0050] The position and timing assistance system 300 comprises a PTA server 310 and a PTA client 324 . The PTA server 310 includes a version control manager 312 that interfaces with almanac database 314 . The almanac database 314 makes inputs to the partition collector 318 . Partition collector 318 receives uploads from upload manager 316 and provides information to download manager 320 .
[0051] Upload manager 316 receives a download request from the upload/download manager 326 of a PTA client 324 . In turn, download manager 320 provides the requested download to PTA client 324 , specifically the upload/download manager 326 . PTA client 324 also includes positioning/measurement engine 328 that interfaces with almanac assistance manager 330 . Almanac assistance manager 330 interfaces with almanac cache manager 334 . Almanac storage manager 332 provides input to almanac cache manager 334 , which also interfaces with the upload/download manager 326 . Almanac cache manager 334 also provides inputs to the personal record manager 336 . In addition the almanac storage manager 332 interfaces with personal record manager 336 . Storage is provided for the almanac storage manager 332 in almanac storage 338 . Almanac cache 340 provides storage for almanac cache manager 340 . Personal record storage 342 provides storage for personal record manager 336 .
[0052] The mobile station is the consumer of the positioning and timing assistance. It downloads position and timing assistance from the position and timing assistance PTA either periodically or as needed (e.g., when a terrestrial radio is observed but no information is available on the mobile), stores them in memory, and then uses this information to assist in the positioning process. The upload/download manager 326 handles the communication with the server 310 and internal requests for position and timing assistance downloading.
[0053] The search process is coordinated by the position and timing assistance manager. It receives assistance requests from the positioning/measurement engine 328 and initiates a search in the following order: the personal record 342 of the mobile station, the almanac cache 340 , the almanac storage 338 , and the position and timing assistance server 310 . The search may also be performed in parallel if a faster search is needed or desired.
[0054] The positioning and timing assistance server 310 collects positioning assistance information, generates position timing and assistance and maintains records of the position and timing assistance requested. The upload manager 316 and download manager 320 interact with the mobile stations, PTA clients, 324 ; the partition collector 318 retrieves the position timing and assistance most relevant to the user's current location; and the version control manager 3112 maintains the position timing and assistance information in a current state.
[0055] The position, timing, and assistance almanac may include various types of information such as Spare network Almanac (SNA) and Base Station Almanac (BSA) information. Sparse network almanacs are, by definition, broad in scope of coverage, but have low precision, thus allowing a small amount of data to cover very broad areas. In contrast, a base station almanac is narrow in scope of coverage, but has high precision, and provides more detail.
[0056] Almanac download selection uses the proposed intelligent server almanac selection to minimize the mobile station's download traffic and time by enhancing the relevance of the downloaded almanac to the current user's context. That context is based on the mobile's current or past context (e.g., current or past location, the current or past list of partitions). The proposed mobile download feedback enhances the relevance of downloaded almanacs to the next mobile or mobiles to access the server by adaptively adjusting the server's almanac selection based on the mobile device's feedback (e.g., hit or miss, a list of utilized almanac version, a list of observed transmitters, and the like).
[0057] The carrier network may need to support multiple air interfaces and partitions need to be capable of working across air interfaces. This applies to both PTA-BSA and PTA-SNA partitions. As air interface types evolve, there are carrier networks and mobile phones supporting multiple air interface types (e.g., GSM/WCDMA networks). Within these networks, the mobile station switches between air interface types frequently and consequently could request multiple PTA downloads in a short period of time. In order to minimize there undesirably frequent download requests, it is preferable for the server to send PTAs for all of the corresponding air interface types. Regardless of whether the mobile is connected through a GSM or WCDMA network, the server sends both GSM and WCDMA PTA partitions for GSM and WCDMA dual-mode mobiles.
[0058] For convenience of PTA partition management, the PTA partitions belonging to different air interface types from a single carrier are managed separately as if they are from separate networks. The association between PTA partitions is maintained through the Cell ID indexing table. Cell ID is only one example, other mechanisms may be used, such as user position, neighboring AP MAC address/SSID, and may be used individually or in combination. Also, the other indexes may be pre-linked to a global index table. For example, the known AP MAC addresses or user positions are pre-assigned to neighboring Cell IDs and when this information is sent to the server, the server converts that information into a Cell ID and uses the Cell ID index table to get a partition list. In this way, each PTA partition can be managed independently and any combination of air interface types can be supported by simply picking and choosing the corresponding partitions from the Cell ID indexing table. Also, any new air interface types can be added simply by creating partitions from the Cell ID indexing table. Also, any new air interface types can be added simply by creating partitions for the new interface type, and updating the Cell ID indexing table without change to the existing partitions.
[0059] The server maintains information about carrier networks and their supported air interface types. The server also maintains a Cell ID indexing table including PTA-BSA partitions for all supported air interface types in the order of their proximity to the serving cell. Hence, the first partition includes the serving cell, followed by partitions containing co-located cells. The rest of the partitions are selected based on proximity to the serving cell. The server should distinguish the following: the partition with the serving cell, the partitions with the co-located cells, and the rest. For example, Cell ID #1 (a GSM cell) is indexed to PTA_BSA_GSM#3 (serving cell's partition), PTA_BSA_WCDMA_#5 (co-located cell's partition), PTA_BSA_WCDMA #1, PTA_GSM #1, PTA_BSA_WCDMA #4, PTA_BSA_GSM #9, . . . .
[0060] The server checks the mobile station's association with air interface types vi AIR_INTERFACE_TYPE in the PTA upload format. If the mobile station supports a single air interface type, the server sends the PTA partitions for the corresponding air interface type to the mobile in terms of BSA and SNA. For example, a GSM only mobile will receive PTA_SNA_GSM along with PTA_BSA_GWM #3, PTA_BSA_GSM#1, PTA_BSA_GSM#9, . . . . . If the mobile station supports multiple air interface types which are supported by the carrier, the server sends the PTA partitions for all air interface types of the mobile station in terms of BSA and SNA. For example, a GSM/WCDMA dual mode mobile station will receive PTA_SNA_GSM and PTA_SNA_WCDMA along with PTA_BSA_GSM#3, PTA_BSA_SCDMA#5, PTA_BSA_WCDMA#1, PTA_BSA_GSM#1, PTA_BSA_WCDMA #4, PTA_BSA_GSM#9, . . . .
[0061] The selection of download PTA-SNAs generally follows the same procedure as described above.
[0062] Download SNA partitions will be selected based on the mobile station's current serving Region ID (e.g., SID/NID, MNC/LAC, or MNC/RNC-ID) or the mobile station's current or past position.
[0063] The embodiments described herein for selective downloading protect the privacy and privilege of entities (e.g., a wireless carrier, building owner, institution, etc.) by enabling almanac downloading selectively according to a particular mobile device's privilege setting and the given almanac downloading permission setting. For example certain high security facility information could be protected from unauthorized personnel.
[0064] The mobile device's download privileges may be represented by explicit or pre-assigned privilege information. The mobile device's download privilege may also be derived from implicit information.
[0065] Explicit privilege information may include a global privilege setting, which permits distinguishing between premium users and basic users based on a service contract, association with entities, such as an employer or agency, or may use a unique device identifier. A unique device group identifier may also be used. If an individual device identification is not provided, or is not used, a group identification may be used to allow privilege setting for a group of devices. Explicit privilege information provides specific privilege limits on downloading of assistance data for each mobile device.
[0066] Implicit privilege information may include a device manufacturer, such as Samsung, HTC, or Nokia, device hardware and software versions where more detailed assistance is provided for users of more recent hardware and software with greater capabilities. The implicit privilege information may also include serving carrier, country, current location, current serving base station, currently associated WiFi AP, or other contextual information Implicit privilege information is used to derive the download privilege for a given mobile device context and may be applied adaptively, where the explicit privilege information is not adaptable.
[0067] The privilege information is intended to limit access to certain sets of information by a particular mobile device. In another embodiment, the privilege information may be used to provide assistance data of enhanced relevance to a mobile device depending on the mobile device's context.
[0068] Related entities, which may include building owners or carriers, may request adjustment of a mobile device's privilege setting to assist in downloading data. The privilege mapping may then be updated on the server and the information delivered to the affected mobile devices may be adjusted accordingly.
[0069] In yet another embodiment, privilege information may be handled either by the mobile device or by the server. The mobile device normally keeps or submits its privilege information to the server. The server then uses the privilege mapping table to map a given mobile device's privilege information to the downloadable information. In an additional embodiment, the server may remember the privilege setting of each mobile device based on each mobile device's unique identifier, where a mobile device submits only its identification information.
[0070] The almanac version control mechanism minimizes mobile downloading traffic and download time by reducing unnecessary almanac revisions. For clarification, “version” or “revision” refers strictly to CONTENT and not to the formats of the PTA partitions.
[0071] The PTA partition revision number will be incremented based on the degree of change of data, not the age of the file. This prevents downloading new PTA data for relatively minor changes, such as minor changes in coverage radius for a region in the partition.
[0072] The overall PTA partition generation procedure consists of two main functional blocks—data aggregation and partitioning manager, with the version control being conducted in coordination of these two blocks to support version control for each PTA partition.
[0073] Version control begins after PTAs are updated from third party uploads and stored in the latest PTA database. The version control (revision) process is performed as part of the overall PTA generation procedure, which will be described.
[0074] The PTA generation process beings for each network when the latest PTAs and the release version PTAs are fetched from the latest PTA database and the PTA release database. Then, the data is analyzed for revision triggering events: region reorganization, or significant region expansion/contraction/shift.
[0075] If the latest PTAs contain significant differences from the last released PTAs (qualified triggering events), the latest PTAs are copied to the PTA release database and become new release version PTAs. Upon revision, the data aggregation engine notifies the portioning manager with the list of affected cells or regions.
[0076] The partitioning manager checks for existing partitions for the newly released PTAs. If there are no existing partitions, partitioning is conducted and all partitions are initialized.
[0077] If there are existing partitions, the existing partition configuration should be applied (e.g., center circle location/radius and partitioning angles in case of the pie-slicing method) to the PTAs and a check made to see if the resulting partitions are legitimate, that is less than the partition size limit. If any partition is not legitimate, then partitioning in conduced. For example, if a new cell is reported in the region, the new cell may be inserted into an existing partition which geographically covers the new cell's center location. Or, if a cell center has moved from one partition area to another partition area, this cell's entry is moved between these two partitions. The next step is to check to see if the affected partitions are still within the partition size limit, (e.g., 2 Kbyte). If the partition size is within the partition size limit, no other partitions in this region need updating. If the partition size is not within the partition size limit, then partitioning is conducted and new partition regions with resulting new partitions are created.
[0078] The newly generated partitions are compared to the existing partitions and the partitions with changes are identified and updated. The comparison is based on the partition contents (e.g., list of cells, cell size, and cell center location), not on the partition configuration. The content comparison is intended to support mobile more efficiently when the mobiles care about the contents of partitions, not how the server generates the partitions. The updated partitions are then copied to the partition database for mobile download.
[0079] FIG. 4 provides a flow chart of the process and illustrates the interaction with the databases. The system and method 400 , operates with a data aggregation engine 402 . This data aggregation engine 402 includes means for data aggregation 404 , the latest PTA database 408 with PTA reorganization flags 408 a , both of which are in communication with the means for PTA comparison 410 . The PTA comparison means 410 is also in communication with the PTA release database 412 , and includes a trigger partitioning manager for new PTA releases. The partitioning manager 414 receives inputs from PTA release database 412 and the PTA comparison means 410 , as well as the partition database 416 .
[0080] The process 400 begins with the PTA comparison means 410 initiating a check for reorganization flags in step 418 . Specifically, a check is made to determine if there is any reorganization flag in the latest PTA. A query is then run in step 420 to check for region reorganization. The check includes looking for any region births or deaths, as well as renumbering. If the region is being reorganized the method proceeds to step 428 where a new PTA release is obtained. If the region is not being reorganized, the next step 422 compares the latest PTA with the released PTA for region changes. The change compares the latest PTA with the last released PTA and looks to see if there is any qualifying change for an PTA revision. The method checks for region changes that are greater than a specified threshold in step 424 . If the changes are greater then the specified threshold, the method proceeds to step 428 where the new PTA release is obtained. If the changes do not exceed the threshold, there is not a new PTA release as shown in step 426 .
[0081] The partitioning manager 414 implements partition changes to the partition configuration using the method described below. The method checks for an existing partition configuration at step 430 , and specifically checks for an PTA partition. If the answer is no, the method continues to step 442 where partitioning occurs. In step 444 a version update is performed on all partitions. If there is an existing partition configuration then that existing partition configuration is applied in step 432 . The existing partition may use angles or grids with the new PTA. The method next checks to see if the new or existing partitions are less than the partition size limit (bytes), in step 434 . If the partitions are not below the partition size limit, the method continues to step 436 where partitioning occurs. If the partitions are below the partition size limit the old and new partitions are compared in step 438 . In step 440 the partition version is updated based on the comparison performed in step 438 .
[0082] The PTA version control includes both PTA-SNA and PTA-BSA, and may accommodate further partition variations. Except for the difference between member region definitions, (for CDMA, SIDs/NIDs for PTA-SNA and SIDs/NIDs/cells for PTA-BSA), all PTA version control follows the procedure described herein. In this context, “region” is more broadly defined and refers to any level of area designation used in XT including SID, NID, or a cell instead of the more narrow and usual reference to NIDs or LACs.
[0083] The PTA server processes BSA third party updates in a batch mode, on a network-by-network basis whose processing periodicity is typically one day. The next concern is when to increment the almanac version at the server. If an almanac has not changes, there is no need to increment the version number, so version control should be based on the degree of change, and not the age of the data. Version control based on the degree of change is helps minimize download data traffic to mobiles.
[0084] A PTA may change in two ways: region expansion/contraction/shift and region reorganization. In case of third party upload, region changes are not expected to occur frequently. The region expansion and contraction may be described by changes in region size (radius) and the region shift by changes in the center location. On the other hand, regions can be re-organized by a carrier as well. A new region may be created, a region may be removed, of the whole network can be re-numbered (changing only the identifiers without any physical change).
[0085] In general, the ordinary region expansion/contraction/shift event are expected to happen frequently, but to cause less significant changes, thus triggering PTA revision only if the accumulated changes are significant enough. Region reorganization events, however, are less frequent but may cause significant changes and are thus classified and treated separately from ordinary expansion or contraction events and triggering PTA revision automatically.
[0086] Table 1 provides a summary of PTA revision triggering events.
[0000]
Recommended
Event Types
Parameters
Action
Comments
Region/
Region center,
PTA revision
Frequent but
cell Expansion/
Region size
only in case of
less significant
Contraction/Shift
(radius)
significant change
events
above threshold
Region/
New/removed/
Automatic PTA
Significant but
cell Reorganization
renumbered
revision
infrequent
(Region birth*/
PTA entry
events
death/
renumbering**)
*Region birth refers to new region discovery by actual region reorganization or simply by first time user observation of an existing region.
**Data aggregation engine detects and sends flags for region reorganization events.
[0087] In the PTA revision process, region reorganization is a qualified event by default and automatically triggers PTA revision. Therefore, there is no separate threshold for region reorganization events. Here, region reorganization refers to an event that affects PTA entries. As one example, if it is PTA-SNA for CDMA, a new NID creation is a qualified reorganization but a new cell creation is not since this cell is not directly represented in SNA.
[0088] Ordinary region expansion/contraction/shift events are compared with thresholds to assess the significance of changes. Since the region expansion/contraction/shift events happen more frequently, these thresholds affect the overall frequency of PTA revision. As a consideration in setting these threshold values, the release version PTA should not deviate from the actual network too much, but at the same time should not be too frequent. Thus, the thresholds should be set to follow region changes closely while maintaining revision rate at a sustainable level.
[0089] These are two example parameters that may be used for version control, however, other parameters may be selected, such as region average altitude, antenna phase center, region population center, among others, may be tracked as well and used as criteria for partition version control. Here, the region center and size are shown as one example illustrating how to measure changes over time and also how to trigger a version update. The two parameters of interest are region center and size (radius). These changes are measured both in percentile and meters in order to monitor both relative and absolute changes. As one example, a revision may be triggered by either a 10% or a 10 Km change in size. The degree of change is measured as follows: first, measures the change on the region center of the individual regions. In this case, new refers to the latest PTA, while old refers to the release version PTA.
[0000]
Center
change
(
m
)
=
∥
new
center
-
old
center
∥
Center
change
ratio
(
%
)
=
∥
new
center
-
old
center
∥
old
radius
×
100
[0090] Second, measure the change on the region size of the individual regions.
[0000]
Size
change
(
m
)
=
∥
new
radius
-
old
radius
∥
Size
change
ratio
(
%
)
=
∥
new
radius
-
old
radius
∥
old
radius
×
100
[0091] Third, combine and take the average degree of changes from all regions in this PTA.
[0000]
Average
center
change
ratio
(
%
)
=
∑
All
regions
center
change
ratio
number
of
regions
Average
size
change
ratio
(
%
)
=
∑
All
regions
size
change
ratio
number
of
regions
[0092] Based on the computed absolute or relative degree of changes, apply the corresponding thresholds given below in Table 2, which captures both local changes on individual member regions and accumulated changes throughout all regions in this PTA. The thresholds are given separately for PTA-SNA and PTA-BSA. For PTA-SNA, thresholds for SID/NID, MNC/LAC, or MNC/RNC are given.
[0093] For PTA-BSA, thresholds are given only for cells to detect only cell changes since the cells are the primary contents of BSA. Consequently, in PTA-BSA, changes in SID/NID, MNC/LAC, or MNC/RNC may not be updated as they are in PTA-SNA and do not trigger revision of PTA-BSA. This avoids any avalanching PTA-BSA revisions due to a single change in one region. If one NID has changed significantly and caused a change in SID, then all BSAs under this SID are affected, although other NIDs have not changed. To prevent this avalanching PTA revision, only cell changes are considered in PTA-BSA revision.
[0094] In a PTA-BSA partition, SID or NID values may not be the same as the corresponding values in a PTA-SNA since SID or NID values are used as a reference to support the efficient representation of the primary contents of PTA-BSA, which are the cell values. These reference values, (SID/NID, MNC/LAC, or MNC/RNC) are updated only when the cell descriptions need to be updated in the PTA-BSA. If an accurate and latest description of SID or NID is required, the PTA-SNA should be referenced, while the PTA-BSA is used to provide an accurate description of cells.
[0095] The PTA revision is triggered if any of the corresponding thresholds is met or exceeded. The thresholds are to be adjusted as tested through mobile uploads and for optimization per radio access technology, separate tables of thresholds are created and maintained for each radio access technology.
[0000]
TABLE 2
PTA-SNA degree of change and thresholds (CDMA)
Region Level
Parameters
Threshold*
SID**
Center
10% or 25 Km
Size (Radius)
10% or 25 Km
NID**
Center
20% or 10 Km
Size (Radius)
20% or 10 Km
Combined***
Center
5%
(all SIDs/NIDs)
Size (Radius)
5%
*Change ration is normalized by region size (radius)
**Thresholds to detect local changes on any single region in this PTA although the rest of the regions are unchanged.
***Thresholds to detect global changes on all regions in this PTA, only applicable if there are multiple regions in this PTA.
[0096] The degree of changed and the thresholds may vary depending on the wireless system as well as the system operating constraints.
[0097] FIG. 5 illustrates triggering events in comparison with the thresholds. In FIG. 5 , region expansion, contraction, and shift cases are illustrated. As one example, assuming thresholds of 10 km and 10%, if a region is observed to have grown, the new estimate has a bigger radius (120 km) than the existing estimate (100 km). In this case, the size change is 20 km and the size change ration is 20%. Since the changes are larger than the corresponding thresholds (10 km and 10%) a new PTA is released. The contracts and shift cases experience the same degree of changes and also trigger PTA revision.
[0098] For tracking freshness of individual PTA entries, time stamps for each PTA entry are kept and updated when new mobile or third party upload data is reported for the corresponding region. Even if the PTA entries are not changed based on the new data, time stamps are still generated upon the latest upload data as an indication of the freshness of individual PTA entries.
[0099] Time stamps are kept because regions in a PTA may experience different rates of mobile uploads. In a PTA, there will be regions more or less frequently visited by mobiles. Other regions are more frequently visited by mobiles and as a result are updated more frequently. This leads to less frequently visited regions having much older PTA entries.
[0100] Within the PTA server, GPS week and GPS milliseconds are used as timestamps. Here, the time resolution does not need to be in milliseconds and resolution within one day should be sufficient, as the PTA is expected to be updated in a 24 hour cycle. However, in order to be consistent with other time stamps in XT, this form of time stamp is used which could be revised if necessary.
[0101] Table 3 shows an example of the form and length of the time stamps that may be used.
[0000]
Time Stamp
Length (bits)
Note
GpsWeek
16
GPS week when this PTA
entry is updated with new
mobile/third party upload
GpsMs
32
GPS milliseconds
[0102] The PTA may contain information accuracy, reliability, and freshness indicators which a mobile may use to determine how accurate, how reliable, and how fresh the information is in the PTA. This information may be detailed or may be more concise. For example, if PTA freshness may be indicated in the time stamp in the time of PTA generation, or may be more compact when quantized as a few bits of an indicator. These indicators are used to minimize download data traffic by providing PTA quality information to the mobile so that a mobile may avoid unnecessary data downloading (e.g., download only old, unreliable, or inaccurate PTA). Even in the case of downloading, the mobile and the server may exchange these light weight indicators before actual PTA downloading so that only the needed partitions, specifically, those in need of updating, are updated. In one example of indicator use at a mobile, a mobile may use this freshness indicator to resolve any possible conflicts between that the mobile observes and what the PTA server tells the mobile. If the discrepancy is real and reported by many mobiles simultaneously to the PTA server, the corresponding PTA will be updated. This mechanism addresses the time gap between when the mobile station observes the discrepancy and when the PTA is actually being updated in a way that the mobile makes its own decision whether or not to trust the current PTA based on the given indicator before the actual PTA update by the PTA server, which usually takes time.
[0103] Table 5 illustrates an example of PTA freshness indicators for a mobile station.
[0000]
Estimation age
3
0
≦1 day
1
>1 day and ≦1 week
2
>1 week and ≦2 weeks
3
>2 weeks and ≦1 month
4
>1 month and ≦4 months
5
>4 months and ≦1 year
6
>1 year
7
reserved
[0104] The embodiments described herein provide numerous advantages over other methods. The proposed mobile local search within its storage and cache reduces traffic to the server and accompanying communication cost, and may also save time.
[0105] The described pre-loading method to the mobile storage enables stand alone operation.
[0106] In addition, the proposed predictive loading (either mobile to server, or mobile internally) enables faster preparation of the necessary almanac, and reduces positioning delay, based on a projected route from among probable routes based on crowd sourcing, user input destination, or application layer information (navigation software routing information).
[0107] The proposed almanac selective downloading also protects the privacy and privilege of entities (e.g., wireless carrier, building owner, or an institution, or similar) by enabling selective almanac downloading according to the given mobile's privilege setting and the given almanac downloading permission setting.
[0108] It is understood that the specific order or hierarchy of steps in the processes disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.
[0109] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.” | A method and apparatus for reporting almanac versions and almanac identification by a mobile station to a server is provided. The server compares the almanac version and almanac identification held by the mobile station with almanac versions and almanac identifications held by the server. The server then sends instructions to the mobile station to match the server versions of the almanac versions and almanac identifications for the almanac versions and almanac identifications that the mobile station should hold. | 6 |
BACKGROUND OF THE INVENTION
[0001] The present invention concerns a fluid distribution assembly, of the type having modules for channelling fluid and for mounting functional components intended to interact with the fluid, and a body having at least one support face for supporting the modules, the said support face having a regular network of fixing elements.
[0002] The invention applies, for example, to the analysis or measurement of characteristics of fluids circulating in industrial installations for this purpose, assemblies of the aforesaid type are used. The body is constituted by a thin plate. The fixing means are threaded holes which pass through the plate and are distributed according to one of the two possibilities provided for by standard ANSI/ISA-76.00.02-2002.
[0003] The holes are therefore distributed so as to form squares, and the spacing between two holes of the same square may be 37 mm or 56 mm.
[0004] Thus it is possible to fix on the plate, fluid channelling modules having dimensions which are also standardised. The modules are thus substantially in the shape of a parallelepiped with square base, the sides of which have a length of 38.2 mm if the first possibility is selected or, respectively, 57.2 mm if the second possibility is selected.
[0005] The modules have internal channels and are arranged one after the other, being connected by connecting members, in order to effect the channelling of the fluid. The modules also serve for the mounting of functional components intended to interact with the fluid, such as valves, taps, pressure gauges, transducers, sensors, etc.
[0006] Owing to the above-mentioned standard, the perforated plates, the modules and the components are interchangeable, whoever their manufacturers, thus making it possible in particular to guarantee reduced costs.
[0007] In order to analyse a fluid, for example in an industrial installation, the fluid distribution assembly, equipped with the appropriate functional components, may be arranged downstream of a branch connection made on the pipe of the installation in which the fluid to be analysed circulates. A filter is generally provided between the branch connection and the fluid distribution assembly, in order to avoid polluting the analysis and measurement components.
[0008] Such known distribution assemblies prove satisfactory, but it is still desirable to reduce their overall dimensions.
SUMMARY OF THE INVENTION
[0009] It is therefore an aim of the invention to solve this problem by providing a distribution assembly of the aforesaid type which is of more reduced overall dimensions.
[0010] To this end, the subject of the invention is an assembly of the aforesaid type, characterized in that a passage for the fluid is provided inside the body.
[0011] According to particular embodiments, the invention may comprise one or more of the following features, taken singly or in all the technically possible combinations:
[0012] the body has at least two support faces, each of which faces has a regular network of fixing means for the modules;
[0013] the fluid passage and the or each support face extend in a longitudinal direction;
[0014] the body has a polygonal cross-section, the or each support face forming one side of the polygon;
[0015] the body has as many support faces as the polygon has sides;
[0016] the fluid passage passes through the body from side to side;
[0017] the fixing means are holes provided in the or each support face of the body;
[0018] the fixing means are distributed at the corners of squares;
[0019] the squares have sides with a length of 37 mm or 56 mm;
[0020] the assembly further comprises functional components intended to be fixed on the or each support face by means of the fixing means in order to interact with the fluid; and the assembly comprises a filter for filtering the fluid, which filter is carried by the body.
[0021] The invention also has as its subject the use of an assembly such as defined above for distributing a supply fluid for an engine of a vessel.
[0022] According to one variant, the fluid is oil.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention will be more easily understood on reading the following description, provided solely by way of example, with reference to the appended drawings, in which:
[0024] FIG. 1 is a diagrammatic view in longitudinal section of a fluid distribution assembly according to the invention,
[0025] FIG. 2 is a diagrammatic section, along the line II-II in FIG. 1 , and illustrating the body of the assembly of FIG. 1 ,
[0026] FIG. 3 is a partial top view of a support face of the body of the assembly of FIG. 1 ,
[0027] FIG. 4 is a diagrammatic front view of the left-hand flange of the body of the assembly of FIG. 1 , seen in the direction of the arrow IV,
[0028] FIG. 5 is a diagrammatic top view of a fluid channelling module of the assembly of FIG. 1 ,
[0029] FIG. 6 is a diagrammatic sectional view of a connecting member which may be used with the assembly of FIG. 1 , and
[0030] FIG. 7 is a diagrammatic side view illustrating a fluid distribution assembly according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] FIG. 1 shows a fluid distribution assembly 1 which principally comprises a body 3 , fluid channelling modules 5 and functional components 7 intended to interact with the fluid. More precisely, the components 7 are components for treating and/or measuring and/or analysing the fluid or its flow.
[0032] The body 3 extends along a longitudinal axis L. It has a substantially cylindrical shape of square section. Thus, the body 3 has four faces 9 ( FIG. 2 ), each of which corresponds to one side of the said square.
[0033] Each face 9 is provided with a regular network of threaded fixing holes 11 . The network complies with standard ANSI/ISA-76.00.02-2002. Thus, the sides of the squares connecting the axes of the holes 11 may have a length l of 37 mm, if the first possibility of this standard is selected.
[0034] As will be seen hereinafter, the network of holes 11 makes it possible to fix on the faces 9 modules 5 , also conforming to standard ANSI/ISA-76.00.02-2002, that is to say, modules 5 which, seen from above, have a substantially square shape with a side length L of 38.2 mm, if the first possibility of the standard is selected.
[0035] The body 3 is traversed by a main fluid circulation passage 13 which extends, inside the body 3 , along the axis L. In the example shown, the main passage 13 is substantially centered in the body 3 .
[0036] Also in the example shown, the main passage 13 receives a filter 15 which comprises a radial filtering member 17 and two hollow plugs 19 . The plugs 19 are inserted into the ends of the passage 13 and are provided with seals 21 . The plugs 19 enclose longitudinally between them the filtering member 17 , maintaining it radially at a distance from the side wall of the main passage 13 . In another variant, the plugs 19 may be welded to the filtering member 17 .
[0037] A first end of the body 3 (on the left in FIG. 1 ) is extended by a first flange 23 for holding the modules 5 . The flange 23 is integral with the body 3 .
[0038] The first flange 23 is traversed by four openings 25 for feeding the fluid towards the modules 5 . These openings 25 are for example evenly distributed angularly around the axis L. The openings 25 are stepped and thus have widened portions 27 which are oriented towards the rest of the body 3 , that is to say, towards the right in FIG. 1 .
[0039] An auxiliary passage 29 for the fluid is also provided in the body 3 . The passage 29 opens out at one end into the side wall of the main passage 13 , substantially in a middle region of the body 3 , then the auxiliary passage 29 extends longitudinally towards the flange 23 , passes through the latter and opens to the outside.
[0040] The flange 23 further includes openings 31 for fixing a closure plate 33 onto the flange 23 . These openings 31 may be distributed in a similar manner to the openings 25 and be arranged in the flange 23 radially further out than the openings 25 .
[0041] The closure plate 33 is traversed by a central opening 35 which communicates with the inside of the plug 19 arranged opposite (on the left in FIG. 1 ), the inside of the plug 19 communicating with the inside of the filtering member 17 .
[0042] The plate 33 holds the plug 19 in place inside the passage 13 .
[0043] A countersink 37 is provided in the face of the closure plate 33 arranged opposite the flange 23 . This countersink 37 places the auxiliary passage 29 and the openings 25 in communication and is, for example, in the shape of a ring.
[0044] Sealing gaskets 39 may be provided in the opposed faces of the flange 23 and of the closure plate 33 .
[0045] All the modules 5 have similar structures and only one will be described hereinafter with reference to FIG. 5 .
[0046] As indicated previously, the module 5 is perfectly conventional and conforms to standard ANSI/ISA-76.00.02-2002. It will therefore be described only briefly. The module 5 is a block substantially in the shape of a parallelepiped which in top view has a substantially square shape, the angles of which are provided with seats 41 intended to receive fixing screws for fixing the module 5 on one of the faces 9 of the body 3 by screwing into its holes 11 .
[0047] In the example shown in FIG. 5 , the module 5 is pierced by a channel 43 intended to be traversed by the fluid and which passes through the module 5 from side to side. The channel 43 opens out into the upper face of the module 5 through an opening 45 which will serve to feed a component 7 mounted on the module 5 via four threaded holes 47 arranged in a square in the module 5 .
[0048] As is also conventional, the modules 5 used in the assembly of FIG. 1 may have shapes and numbers of channels 43 or openings 45 different from those of the module 5 shown in FIG. 5 .
[0049] In the assembly of FIG. 1 , each face 9 is equipped with modules 5 which are aligned one after the other along the longitudinal axis L. In some applications, however, some faces 9 may be unused. Communication between the different modules 5 and with the widened portions 27 of the openings 25 of the first flange 23 is effected in a conventional manner by connecting members 49 inserted into the ends of the channels 43 and into the portions 27 .
[0050] Also conventionally, components 7 are mounted on the modules 5 .
[0051] It will be observed that only some of the modules 5 and of the components 7 have been shown in FIG. 1 .
[0052] The component 7 at the top left in FIG. 1 may for example be a valve, the following component 7 on the right may be a pressure gauge, and the bottom component 7 on the left may be a filter cleaner. Thus, on each face 9 a circuit is formed, the whole of the circuits making it possible to carry out the required measurements and analyses of the fluid. It will be noted that elbowed connecting members 63 ( FIG. 6 ) may be used in some variants to connect to one another modules 5 provided on adjacent faces 9 and therefore the circuits which they carry.
[0053] The body 3 is provided at its second end (on the right in FIG. 1 ) with a second flange 51 for holding the modules 5 . The flange 51 is screwed onto the body 3 and, like the flange 23 , has four openings 25 terminating in flared portions 27 . The flange 51 holds the straight plug 19 in place in the main passage 13 .
[0054] Connecting members 49 (not shown) are engaged in the portions 27 of the second flange 51 and the modules 5 located furthest on the right in FIG. 1 . A connecting member 49 is arranged between the modules of each pair of modules 5 . It will additionally be recalled that connecting members 49 are arranged between the first flange 23 and the modules 5 located furthest on the left in FIG. 1 .
[0055] The modules 5 are therefore on the one hand fixed on the faces 9 by screwing into the holes 11 , and on the other hand held longitudinally via the connecting members 49 and the flanges 23 and 51 .
[0056] In the example shown, a countersink 52 extending over about 180° around the axis L connects the lower opening 25 and the two middle openings 25 of the second flange 51 . This countersink 52 , for example in the shape of a sector of a crown, is closed by a closure plate 53 fixed on the flange 51 . The plate 53 has a central opening 35 , similar to the opening 35 of the plate 33 , and two stepped fluid passage openings 57 which have passed through the modules 5 . One of these openings 57 is located opposite the upper opening 25 and communicates with the latter. The other opening 57 is located opposite the lower opening 25 of the flange 51 and communicates with the opening 25 and the countersink 52 .
[0057] The assembly 1 of FIG. 1 is for example arranged on a branch loop of the oil supply circuit of the engine of a vessel, for example an oil tanker.
[0058] The fluid circulating in the branch loop, in the present instance oil, penetrates into the left-hand opening 35 as represented by the arrow 59 in FIG. 1 . Part of the fluid flows longitudinally inside the filtering member 17 and emerges through the other opening 35 , as represented by the arrow 61 , before being returned towards the remainder of the branch loop and then towards the supply circuit of the engine. The body 3 thus forms a portion of the branch loop.
[0059] Another part of the fluid having penetrated into the filtering member 17 is filtered while passing radially through the filtering member 17 , then circulates in the auxiliary passage 29 and is returned through the countersink 37 to the openings 25 of the flange 23 . This other part of the fluid feeds the alignments of module 5 provided on each face 9 . The fluid then passes through the circuits formed on each of the faces 9 through the modules 5 and the components 7 where the required measurements and analyses are carried out.
[0060] The fluid is then collected on the one hand by the upper openings 25 of the flange 51 and of the plate 53 and on the other hand by the lower and middle openings 25 of the flange 51 , by the countersink 52 and by the lower opening 57 of the plate 53 . The collected fluid is then returned towards the branch loop and the oil supply circuit.
[0061] It will be observed that the upper opening 57 of the plate 53 may be dedicated, for example, to the evacuation of a polluted fraction of the fluid, in which case this fraction is not returned towards the branch loop or the main circuit. It will also be noted that, according to requirements, the countersink 52 may for example connect only two openings 25 , that another countersink 52 may be used simultaneously, that no countersink 52 may be provided, etc.
[0062] The assembly 1 of FIG. 1 has particularly reduced overall dimensions.
[0063] This is due on the one hand to the fact that the body 3 itself has an inner passage 13 intended for the circulation of the fluid, and on the other hand to the fact that the body 3 has a plurality of support faces 9 for supporting the modules 5 arranged around the passage 13 .
[0064] It will also be observed that the transport time for the fluid between the main passage 13 and the components 7 is reduced, thereby increasing the relevance of the measurements and analyses carried out.
[0065] In general, numerous other arrangements may be used.
[0066] Thus, by way of example, FIG. 7 illustrates another embodiment in which the assembly 1 is mounted on a flange 65 of a branch connection 67 provided on a pipe 69 of an industrial installation.
[0067] As illustrated by the arrow 71 , the fluid passes through the passage 13 , which does not include a filtering member, flowing upwards (in FIG. 6 ), is filtered in an upper filter 72 integral with the body 3 , and is then returned downwards in order, as illustrated by the arrows 73 , to pass through the alignments of modules 5 provided along the faces 9 , before being returned towards the pipe 69 . It will be observed that the components 7 have not been shown in FIG. 6 in order not to overload it.
[0068] In general, other shapes of body 3 may be used, for example polygonal cross-sections other than square and the body 3 may be made in a plurality of parts.
[0069] Similarly, the number of support faces 9 may be varied, and may in particular be less than four. It is also possible, for example, to use a body 3 which has only one support face 9 for supporting modules. The simple fact of providing in the body 3 a passage 13 intended for the fluid makes it possible to save space.
[0070] Conversely, it is possible to use a body 3 having a plurality of support faces 9 , each corresponding, for example, to the side of a polygon, without using an inner passage 13 in the body 9 .
[0071] Still more generally, the passage 13 is not necessarily a passage intended to be traversed by the fluid. It may thus be, by way of example, a fluid accumulation passage, from which the fluid is expelled, after accumulation, by means of a piston in order to pass through the alignment(s) of modules 5 provided on the support face(s) 9 of the assembly 1 .
[0072] Also in general, the holes 11 may be replaced by other fixing means, for example protuberances, and be arranged in the form of a regular pattern other than those described previously. That would be the case especially if the aforesaid standard were to evolve or be replaced by a standard imposing different constraints.
[0073] It will also be noted that the body 3 , the modules 5 and the components 7 may be sold separately.
[0074] It will be observed that the above principles may be used in numerous fields and especially in industrial installations or vehicles. | A fluid distribution assembly includes modules for channelling fluid and for mounting components a body having at least one support face for supporting the modules, the support face having a regular network of elements for fixing the modules. A passage for fluid is provided inside the body. The assembly finds application in the analysis of fluids circulating in industrial installations. | 5 |
FIELD OF THE INVENTION
The present invention relates to security fibers, a process for the preparation thereof and a security paper containing same.
BACKGROUND OF THE INVENTION
Security documents such as bank notes, stocks, bonds, checks, warrants and identification cards need to be guarded by antifalsification measures and they are often made from a security paper having a security element in the form of fibers, strips or threads embedded therein.
Japanese Laid-open Patent Application No. 90-293500 discloses a security paper containing security fibers prepared by dyeing a natural or synthetic fiber uniformly with a visible or invisible fluorescent dye and cutting the dyed fiber to a given length. However, such monochromatic security fibers have limited effectiveness in the prevention of counterfeiting.
Korean Patent No. 111,723 describes multi-colored security fibers prepared by a process comprising the steps of: placing a mask over a section of a fiber and dyeing the exposed section of the fiber with a first dye; replacing the mask over to the dyed section thereby exposing the undyed section; dyeing the undyed section of the fiber with a second dye; and cutting the fiber to a suitable length to obtain multi-colored security fibers having an enhanced security feature.
However, this complicated process has a low productivity.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to provide an improved process for preparing security fibers suitable for use in a security paper.
It is another object of the present invention to provide novel security fibers suitable for use in a security paper.
It is still another object of the present invention to provide a security paper containing security fibers having an enhanced security features.
In accordance with one aspect of the present invention, there is provided a process for preparing security fibers which comprises the steps of: i) braiding 5 to 30 denier fibers to form a twine; ii) dyeing the twine with a dye or pigment; iii) drying the dyed twine; and iv) cutting the dried twine to give the security fibers in the form of cut fibers.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will become apparent from the following description of the invention, when taken in conjunction with the accompanying drawings, in which:
FIG. 1 shows a schematic diagram of braided fibers in the form of a two-thread twisted twine;
FIGS. 2 depicts a schematic diagram of braided fibers in the form of a three-thread twine;
FIG. 3 demonstrates one embodiment of the security fibers prepared in accordance with the present invention; and
FIG. 4 illustrates one embodiment of the inventive security paper containing embedded security fibers prepared in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In practicing the present invention, a 5 to 30 denier fiber 1 , which may be any one conventionally used in the art including natural fibers and synthetic fibers such as polyamide, rayon, polyester and cotton thread, may be braided in the form of a two-thread twisted twine 21 as shown in FIG. 1, a three-thread twine 22 as illustrated in FIG. 2, a twine twisted around a suitable pad, e.g., a wire, a twisted twine with a marking band and the like.
The braided fibers are dyed with a dye or pigment in a conventional manner. Exemplary dye or pigment which may be used in the present invention may be any one conventionally used in the art including acid dyes and direct dyes such as Acid Blue AS, Acid Rhodamine B, Uvitex, Papilion Yellow F, TBF(terasile brilliant flavine) and GFF.
The braided fibers dyed in accordance with the present invention have various shades of color because each fiber is partially masked by other fiber(s) and sections thereof are dyed to different shades depending on the degree of masking.
The shades of color in a fiber can be controlled by adjusting the extent of twist torsion and dyeing time. When the twist strength is high and the dyeing time is short, the area of the twisted fiber which is tightly shielded by other fibers may remain undyed as shown in FIG. 3 wherein the portion 31 is dyed whereas the portion 32 is not dyed.
The dyed fiber may be cut by using any of the conventional method well known in the art to a given length, preferably 3 to 6 mm.
In practicing the present invention, the dyed and cut fiber may be further dyed with another dye/pigment to obtain fibers having various shades of two or more colors. The dye/pigment suitable for use in the second dyeing step may be any one conventionally used in the art including acid dyes and direct dyes such as Acid Blue AS, Acid Rhodamine B, Uvitex, Papilion Yellow F, TBF(terasile brilliant flavine) and GFF.
When the second dyeing process is carried out at a high temperature, e.g., from 80 to 100° C., the fiber may be transformed into an S-shaped form, thereby enhancing its anti-counterfeiting feature.
The security fibers having varying color shades prepared in accordance with the present invention may be used in manufacturing a security paper by employing any of the conventional papermaking method well known in the art.
For example, the security fibers of the present invention may be mixed with papermaking materials to provide a security paper containing the security fibers uniformly dispersed therein as illustrated in FIG. 4 .
The following Examples are intended to further illustrate the present invention without limiting its scope.
EXAMPLE 1
Preparation of Security Fiber
20 denier polyamide fiber was braided in the form of two-thread twine as shown in FIG. 1 .
Acid Blue AS was dissolved in water at pH 4-5 to a concentration of 1-2 wt % to obtain a dye solution. The braided fiber was added to the dye solution and dyed at about 90° C. for 10-30 minutes, washed thoroughly with warm water and dried. Then, the dyed fiber was cut to a length of 3-5 mm.
The cut fibers above were dyed in a 1-2 wt % TBF solution at about 90° C. for 10-30 minutes, washed thoroughly with water and dried to give security fibers of the present invention.
EXAMPLE 2
Preparation of Security Paper
10 wt % of a mixture of titanium dioxide, white carbon, talc and calcium carbonate, and 0.1-1 wt % epoxy resin were added to a 0.2-1% wood pulp suspension in stock chest to form a paper making stock.
The security fibers obtained in Example 1 were added to the paper making composition obtained above, to a concentration of 0.002-1.0%. The mixture was stirred well and formed into a security paper of 60-100 g/m 2 .
While the invention has been described with respect to the above specific embodiments, it should be recognized that various modifications and changes may be made to the invention by those skilled in the art which also fall within the scope of the invention as defined by the appended claims. | Security fibers having enhanced antifalsification features are prepared by a process which comprises the steps of: i) braiding 5 to 30 denier fibers to form a twine; ii) dyeing the twine with a dye or pigment; iii) drying the dyed twine; and then iv) cutting the dried twine to give the security fibers in the form of cut fibers. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an automatic transmission control. The control is used in connection with a solenoid valve which accomplishes gear ratio stages. More particularly, the control method is useful for a full automatic electronic controlled transmission.
2. Description of the Prior Art
A conventional electronic controlled transmission is disclosed, for example, in Japanese Laid-Open Publication No. 60-30864 (TOKU-KAI-SYO 60-30864), issued on Feb. 16, 1985.
FIG. 4 of the accompanying drawing shows a conventional type of a solenoid valve 100 for use in such a transmission, the solenoid valve comprising an electromagnetic coil 101, a core 102 and a plunger 103. An electronic controlled transmission is equipped with a plurality of those conventional solenoid valves which establish a plurality of gear ratio stages in connection with an operation of a manual shift valve.
As seen from FIG. 4, there is a clearance 104 between the core 102 and the plunger 103. A spring 105 is provided between the core 102 and the plunger 103 which produces a proper tension to bias the plunger 103 away from the core. An inlet oil conduit 106 is connected to an inlet port 107 of the solenoid valve 100. An outlet oil conduit 108 is formed in the solenoid valve 100.
The above mentioned solenoid valve is a normally closed type of solenoid valve. When the solenoid valve 100 is magnetized, the plunger approaches the core whereupon the inlet conduit 106 and the outlet conduit 108 are communicated with each other. On the other hand, when the solenoid valve 100 is demagnetized, the spring extends the plunger so that the inlet conduit 106 and the outlet conduit 108 are not communicated with each other.
During the operation of the electric controlled transmission, if trash invades the clearance 104 of the solenoid valve 100, the operation of the solenoid valve 100 may be interrupted. This operating condition is called "solenoid-stick" which obstructs the operation of the electronic controlled transmission and can result in the engine overrunning, especially if the transmission had been signalled to down-shift when the solenoid-stick occurred.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a control method for an automatic transmission in which the above mentioned drawback of the conventional apparatus is eliminated.
It is a further object of this invention to provide a control method for an automatic transmission in which the overrunning of an engine can be prevented despite the sticking of a solenoid valve.
In accordance with the invention, when trash is accumulated in the clearance of a solenoid valve whereupon the operation of the solenoid valve is obstructed, a flow of electric current is cut off such that the plunger is returned to a closed state by the tension of a spring and overrunning of the engine is prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic depiction of a hydraulic circuit diagram, portions of which are shown in FIG. 1a through FIG. 1e;
FIG. 1a is a partial circuit diagram of the hydraulic circuit of the automatic transmission according to claim 1;
FIG. 1b shows a partial circuit diagram illustrating a hydraulic circuit of an automatic transmission;
FIG. 1c shows a partial circuit diagram illustrating a hydraulic circuit of an automatic transmission;
FIG. 1d shows a partial circuit diagram illustrating a hydraulic circuit of an automatic transmission;
FIG. 1e shows a partial circuit diagram illustrating a hydraulic circuit of an automatic transmission;
FIG. 2 shows a block diagram illustrating a system for controlling solenoid valves;
FIG. 3 shows a flow chart illustrating an embodiment of the control method according to this invention;
FIG. 4 is a longitudinal sectional view of a solenoid valve for an electronic controlled automatic transmission;
FIG. 5 illustrates the speed of an engine, the signal of down shifting and the gear change of the transmission all as a function of time.
Table 1 shows a relation between the shift lever positions and the operation of the solenoid valve.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Features and advantages of this invention will become apparent from the following description and the accompanying drawing.
With reference to FIG. 1a, a hydraulic circuit control system is associated with a torque converter 10 and gear change mechanism. FIG. 1b includes a lock-up control valve 27, a torque converter control valve 28 and a lubrication control valve 29. FIG. 1c includes a 1-2 shift valve 14, a 2-3 shift valve 16, a 3-4 shift valve 16; an accumulator valve 20 for brake B1, an accumulator valve 22 for brake B2, an accumulator valve 23 for clutch C2, an accumulator valve 21 for clutch C1, an accumulator valve 23' for clutch C2 and an exhaust control valve 26. FIG. 1d depicts a first signal valve 24, a second signal valve 25 and solenoid valves SOL1, SOL2, SOL3. FIG 1e depicts a hydraulic pump 11, a manual valve 13, a throttle valve 17, a primary regulator valve 18 and a throttle modulator valve 19.
In the hydraulic circuit of the automatic transmission of FIG. 1e, an oil line L1 extending from the hydraulic pump 11 via the primary regulator valve 18 is connected to the manual valve 13. The oil line L1 is connected to oil lines L2, L3, L4, L5,, L6 and L7 via the manual valve 13. The solenoid valves SOL1, SOL2, clutches C1, C2 and brakes B1, B2 and B3 are operated, as shown in Table 1 in accordance with shift lever positions R, N, D, 3, 2, and 1.
In FIG. 1b, the lock-up control valve 27 having a spool 27a is controlled by operation of the solenoid valve SOL3 located within the hydraulic circuit control system. A lock-up clutch 30 is activated in response to operation of the solenoid valve SOL3. More specifically, when the solenoid valve SOL3 is in a magnetized state, the oil line L8 is closed and the spool 27a is urged into the rightward direction by hydraulic pressure from the line L7, whereby lines L9 and L7' are brought into communication to supply pressurized oil that engages the lock-up clutch 30. When the solenoid valve SOL3 is in a demagnetized state, on the other hand, pressurized oil from the line L7 drains from the line L8, so that the spool 27a is held at its left side position in FIG. 1 by a spring 27b. As a result, the lines L9 and L7' are cut off from each other so that the lock-up clutch 30 is disengaged.
As seen from FIG. 1d, the first signal valve 24 is provided with a spool 24a and the pressurized oil supplied to the first signal valve 24 is transmitted to the 1-2 and 3-4 shift valves 14, 16. The first signal valve 24 is controlled by the operation of the spool 24a. The valve spool 24a is controlled by operation of the solenoid valve SOL1. When the solenoid valve SOL1 is in a demagnetized state, the oil line L1 communicates with an end of the spool 24a whereby the spool 24a is urged downwardly by hydraulic pressure from the line L1. A line L10 from the second signal valve 25 and a line L11 to the 3-4 shift valve 16 then communicate with each other. On the other hand, When the solenoid valve SOL 1 is in the demagnetized state, pressurized oil drains from the line L1, so that the spool 24a is held at its upward position by tension of a spring 24b of the first signal valve 24. The second signal valve 25 is provided with a spool 25a, and the pressurized oil supplied to the second signal valve 25 is transmitted to the first signal valve 24 which is controlled by the spool 25a of the second signal valve 25. The second signal valve 25 is controlled by operation of the solenoid valve SOL2. When the solenoid valve SOL2 is in the demagnetized state, the line L2 communicates with an end of the spool 25a and the spool 25a is urged downwardly by the hydraulic pressure from the line L2. The line L2 from the manual valve 13 and the line L-0 to first signal valve 24, 1-2 shift valve 14 and 2-3 shift valve 15 communicate with each other. On the other hand, when the solenoid valve SOL2 is in the demagnetized state, pressurized oil drains from the line L2, so that the spool 25a is held at its upward position by tension of a spring 25b of the second signal valve 25.
TABLE 1______________________________________Manual Various StateValve of the Solenoid ValveOperation Transmission SOL1 SOL2______________________________________R -- XN -- X XD (4) X X 3 X 2 1 X3 3 X 2 1 X (3) X X2 2 1 X (2) X X1 1 X (1) X X______________________________________
Thus, the gear ranges in the automatic transmission are shifted by control based on operation of the two solenoid valves SOL1, SOL2, and the lock-up clutch 30 in engaged and disengaged by control based on operation of the solenoid valve SOL3. Table 1 shows a relationship between the solenoid valves SOL1 and SOL2 in the magnetized state and in the demagnetized state, which are controlled by the microcomputer 50.
The three solenoid valves SOL1, SOL2 and SOL3 are operated by the microcomputer 50, as shown in FIG. 2. The microcomputer 50 has its output side connected to the solenoid valves SOL1, SOL2 and SOL3 of the hydraulic control system, and controls these solenoid valves in response to input signals received from various sensors.
The solenoid valves SOL1, SOL2, and SOL3 are preferably of the type depicted in FIG. 4, the operation which was described earlier herein.
The control performed by the microcomputer 50 for establishing the various gear ranges in the automatic transmission will now be described with reference to a flow chart of FIG. 3.
FIG. 3 explains the flow of a detected signal which is produced by engine operation. As shown in FIG. 3, a step (a) requires that the engine revolution per minute (engine RPM) be read while the engine is operated. This is followed by a step (b) wherein it is determined whether the engine RPM is higher than a predetermined engine RPM. If the answer is YES, (i.e., the engine RPM is higher than the predetermined engine RPM), an operational signal from the step (b) is generated for a step (c). If the answer is NO (i.e., the engine RPM is lower than the predetermined engine RPM), the operational signal from the step (b) is generated for a step (d). At the step (c), the electric current is not turned on or transmitted to the solenoid valve SOL2. At the step (d), the electric current is turned on or transmitted to the solenoid SOL2.
By turning off electric current to the solenoid SOL2 in that manner, the risk of the engine overrunning due to a solenoid-stick condition is prevented. That is, as described earlier herein, if trash enters a clearance 150 of either or both of solenoid valves SOL2, SOL3 (shown in FIG. 4 with respect to a solenoid valve 100), the operation of the solenoid valves SOL1 and SOL2 will be disturbed, since that trash causes "solenoid-stick". When the throttle valve 17 of the hydraulic circuit is operated to a full throttle position in response to a rapid depression of the accelerator pedal (not shown), a downshift is attained wherein the microcomputer 50 produces a shift control signal for solenoid valves SOL1 and SOL2. Under the "solenoid-stick" condition, however, the down shift control oversteps the predetermined shift position, whereupon the engine may overrun for a sufficient period of time to be damaged.
In this invention, when the detected rpm of the signal is higher than a predetermined level, the microcomputer produces a cut-off signal for the solenoid valves which return to the demagnetized position. This operation prevents the engine from overrunning for a time period greater than the time required for the microcomputer to produce the cut-off signal.
For example, as illustrated in FIG. 5, if a vehicle operator traveling in fourth gear presses down on the accelerator to effect a down-shift condition, the solenoid valves SOL1 and SOL2 will be energized with the intention of down-shifting the transmission from fourth gear to second gear. However, if trash is present which prevents opening of a solenoid valve, the transmission will instead downshift to first gear which will result in an overrunning of the engine and possible damage to the engine. In accordance with the present invention, however, the condition wherein the engine rpm exceeds the predetermined engine rpm will be detected, whereupon the solenoid valves will be de-energized. As a result, the transmission will be returned to fourth gear, thereby avoiding damage to the engine.
While this invention has been described fully and completely with special emphasis upon a single preferred embodiment, it should be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described herein. | An automatic transmission is controlled by detecting engine rmp following a transmission downshift and comparing the detected engine speed with a predetermined speed value. If the detected speed does not exceed the predetermined value, the solenoids controlling the down-shift are maintained energized. If the detected speed exceeds the predetermined speed value, the solenoids are de-energized to prevent overrunning of the engine. | 8 |
RELATED APPLICATIONS
This application is a continuation-in-part application of U.S. patent application Ser. No. 11/246,152, filed Oct. 11, 2005, now U.S. Pat. No. 7,862,845.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for producing a highly purified Stevioside and Rebaudioside A from the extract of the Stevia rebaudiana Bertoni plant and use thereof in various food products and beverages.
2. Description of the Related Art
In view of food sanitation, the use of artificial sweeteners such as dulcin, sodium cyclamate and saccharin has been restricted. However natural sweeteners have been receiving increasing demand. Stevia rebaudiana Bertoni is a plant that produces an alternative sweetener that has an added advantage of being a natural plant product. In addition, the sweet steviol glycosides have functional and sensory properties superior to those of many high potency sweeteners.
The extract of Stevia rebaudiana plant contains a mixture of different sweet diterpene glycosides, which have a single base—steviol and differ by the presence of carbohydrate residues at positions C13 and C19. These glycosides accumulate in Stevia leaves and compose approximately 10%-20% of the total dry weight. Typically, on a dry weight basis, the four major glycosides found in the leaves of Stevia are Dulcoside A (0.3%), Rebaudioside C (0.6%), Rebaudioside A (3.8%) and Stevioside (9.1%). Other glycosides identified in Stevia extract include Rebaudioside B, C, D, E, and F, Steviolbioside and Rubusoside.
The physical and sensory properties are well studied only for Stevioside and Rebaudioside A. They were tested for stability in carbonated beverages and found to be both heat and pH stable (Chang and Cook, 1983). The sweetness potency of Stevioside is around 210 times higher than sucrose, Rebaudioside A in between 200 and 400 times, and Rebaudioside C and Dulcoside A around 30 times (Phillips, 1989 and Tanaka, 1997).
However, apart from its high level of sweetness, they have also intrinsic properties of post-bitter taste and unpleasant and undesirable aftertaste. Some undesirable taste characteristics of glycosides can be as a result of contamination of other substances, presented in extract.
One of the main ways to improve the taste quality is the enzymatic glycosylation of mixture of semi-purified steviol glycosides. Another way to produce highly purified individual glycosides with standard characteristics and minimal content of accompanying compounds.
The invention related to the purification of two main glycosides—Stevioside and Rebaudioside A and use thereof.
A process for the recovery of diterpene glycosides, including Stevioside from the Stevia rebaudiana plant is described (U.S. Pat. No. 4,361,697). A variety of solvents, having different polarities, were used in a sequential treatment that concluded with a high performance liquid chromatographic (HPLC) separation procedure.
A method for the recovery of Rebaudioside A from the leaves of Stevia rebaudiana plants has been developed (U.S. Pat. No. 4,082,858). Again, final purification is achieved by liquid chromatography subsequent to an initial extraction with water and an alkanol having from 1 to 3 carbon carbons, preferably methanol. It is also known that water may be used as the initial solvent; their preferred solvent at this stage is a liquid haloalkane having from 1 to 4 carbon atoms. The preferred second solvent is an alkanol having from 1 to 3 carbon atoms, while the preferred third solvent is an alkanol having from 1 to 4 carbon atoms and optionally minor amounts of water.
Individual sweet glycosides can be obtained from the Stevia rebaudiana plant. A mixture of sweet glycosides extracted from the Stevia rebaudiana plant is processed to remove impurities by using two types of ion-exchangers. After removing the mixed sweet glycosides from the second column with methanol, the solution is dried. Upon refluxing the dried solids in a methanol solution and then cooling the solution, Stevioside precipitates out. The filtrate is further concentrated and cooled to precipitate out Rebaudioside A. This Rebaudioside A can be further purified as can the previously obtained Stevioside (U.S. Pat. No. 5,962,678). However, a large amount of toxic organic solvent, such as methanol is used.
However, all the above-mentioned methods allow the production of Stevioside and Rebaudioside A not in highly purified grade, which further possess a residual bitterness and aftertaste.
On the other hand, the unfavorable taste of the glycosides can be as a result of contamination of impurities, presented in extract. Highly purified Stevioside and Rebaudioside A possessing an improved taste profile and there is a need to provide an easy and commercially valuable process for the manufacturing the highly purified Stevioside and Rebaudioside A, and use thereof in various beverages and food products.
SUMMARY OF INVENTION
An object of the present invention is to provide a commercially valuable process for producing a highly purified sweetener from the extract of Stevia rebaudiana Bertoni plant and use thereof in various food products and beverages, which overcomes the disadvantages of the related art.
The invention, in part, pertains to the dried and powdered leaves being subjected to water extraction and the resulted extracts is purified using treatment with a base such as calcium hydroxide and then iron chloride. The filtrate was deionized on, e.g., Amberlite FPC23H, Amberlite FPA51, and Amberlite FPA98Cl. The filtrate is concentrated under vacuum and spray dried. The isolation and purification of Stevioside and Rebaudioside A were developed using alcoholic precipitation and ultrafiltration. The highly purified Stevioside and Rebaudioside A were obtained. Any type of existing Stevia extract with various ratio of sweet glycosides are feasible.
The highly purified glycosides were applied in various foods and beverages as sweetener.
The invention, in part, pertains to a purified sweet glycosides extract produced from the Stevia rebaudiana plant, wherein the main sweet glycosides are Rebaudioside A and Stevioside, obtained by a process including drying Stevia rebaudiana leaves, treating the leaves to extract an aqueous liquid solution containing mixed sweet glycosides, extracting the Stevia rebaudiana leaves, obtaining an extract, filtering the extract, obtaining a filtrate, treating the filtrate with a base such as calcium hydroxide, treating the extract with trivalent iron chloride, desalting, decolorizing, and evaporating the filtrate to dryness.
In the invention, purified Rebaudioside A and Stevioside can be obtained by dissolving sweet glycosides in methanol at ambient temperatures to precipitate Stevioside, filtering the solution to recover a precipitate of Stevioside, purifying, recovering a high purity Stevioside, concentrating the remaining solution and evaporating to dryness, suspending the powder in ethanol, heating and then cooling the solution to precipitate Rebaudioside A. Suspending the crystalline Rebaudioside A obtained in ethanol-water solution at cool conditions (10-12° C.) prepares a high purity of Rebaudioside A. Stevioside or Rebaudioside A has a purity of at least 98%. Applications are found in various foods such as chocolate, ice cream, beverage, dairy products, as a sweetener in a tablet form.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the embodiments of the invention.
FIG. 1 shows a sensory evaluation of raw Stevia extract, Stevioside, and Rebaudioside A;
FIG. 2 shows a sensory evaluation of Stevioside with a different grade of purity; and
FIG. 3 shows a sensory evaluation of Rebaudioside A with a different grade of purity;
DETAILED DESCRIPTION
Advantages of the present invention will become more 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.
The dried leaves of Stevia rebaudiana Bertoni were extracted by 10 volumes of water. The proportion of extraction water preferably was about 5 liters to about 15 liters (pH 6.0 to 7.0) to one kilogram of leaves. Greater volumes of solvent can be used, however, it was not preferable from the practical standpoint. The duration of extraction may be from 0.5 hours to 24 hours, with a period of from about 1 hours to about 6 hours preferred.
The extraction temperature can be in the limits of 25-90° C., however the temperatures between 45-75° C. are more preferable.
The plant material was separated from the solution by filtration, and the pH of the filtrate was adjusted to about 10 with calcium hydroxide and heated between 40-60° C., preferably from 50° C. to 55° C., for about 0.5-1.0 hours, cooled to ambient temperature with slow agitation, and neutralized by FeCl 3 . After mixing for 10-15 minutes, the precipitate was removed by filtration; the filtrate was passed through the Celite, deionized, and decolorized by Amberlite FPC23H, Amberlite FPA51, and Amberlite FPA98Cl by conventional manner. The solution was concentrated and spray dried.
The yellow powder had a content of 3.4% Dulcoside, 64.6% Stevioside, 6.7% Rebaudioside C and 25.3% Rebaudioside A.
An HPLC analysis of the obtained product was carried out using an Agilent Technologies 1100 Series (USA) equipped with Zorbax-NH 2 column using acetonitrile-water gradient from 80:20, v/v (2 minutes) to 50:50, v/v during 70 minutes and UV detector at 210 nm.
The obtained powder was dissolved in methanol and maintained at a temperatures 20-50° C., preferably at 20-25° C., for 0.5-6.0 hours, preferably 0.5-1.0 hours with agitation. The proportion of extract and methanol was between 1:2-1:7, w/v, preferably 1:5. During this time the precipitate was formed, which was filtered and dried. According to the HPLC analysis, the powder contents were around 90-91% of Stevioside. A second treatment by methanol was not efficient to prepare high purity Stevioside.
For the further purification, the powder was mixed with two volumes of 90% of ethanol and at 10-12° C. and maintained for about 30 minutes with slow agitation. The precipitate was separated by filtration and dried under vacuum. The Stevioside with about 98.5-99.4% purity was obtained.
The filtrates were combined and used for recovery of Rebaudioside A. For this purpose the remaining solution was evaporated to remove the methanol, the syrup obtained diluted with water and passed through polysulfone based ultrafiltration membranes (with a filtering discrimination of 2.5 kDa) (Liumar Technologies, Ottawa, Canada) with diafiltration. The filtrate was concentrated and spray dried. The obtained powder was mixed with 96.2% ethanol and maintained at 45-50° C. for about 30 minutes with agitation. The proportion of syrup and ethanol was between 1:2-1:7, w/v, preferably 1:5. During this time the precipitate was formed, which was filtered and dried. Rebaudioside A with 88-90% purity was obtained. For the further purification the powder was mixed with two volumes of 92% ethanol and maintained at 10-12° C. for about 60 minutes with slow agitation. The crystals were filtered and dried. Rebaudioside A with 98.9% purity was obtained.
Based on the results of preliminary test on the sweetening power of the sweeteners, aqueous solutions of commercial Stevia extract (0.05%) commercialized by Ganzhou Julong High-Tech Food Industry Co., Ltd (China), Stevioside (0.07%), and Rebaudioside A (0.028%) were prepared.
The organoleptic test was carried out with 30 previously trained panel members. It was observed that Rebaudioside A has the highest sweetness level (5.96), followed by Stevioside with a mean score of 4.62, and commercial Stevia extract had the lowest mean score of 2.96. Rebaudioside A had the lowest score for bitterness (1.76), and commercial Stevia extract was the most bitter compared to the other samples. For overall acceptability, Rebaudioside A had the highest score of 4.05 followed by Stevioside (3.81) and raw extract (3.16) ( FIG. 1 ).
The taste profile of Stevioside with 99.3% of purity was more preferable as compared with 90.2 and 95.4% ( FIG. 2 ). The similar feature was obtained for Rebaudioside A with various grades of purity ( FIG. 3 ).
The highly purified sweeteners can be favorably used for seasoning various food products (for instance, soy sauce, soy sauce powder, soy paste, soy paste powder, dressings, mayonnaise, vinegar, powdered vinegar, bakery products and confectioneries, frozen-desserts, meat products, fish-meat products, potato salad, bottled and canned foods, fruit and vegetables) in intact or mixed forms with other sweeteners, such as corn syrup, glucose, maltose, sucrose, lactose, aspartame, saccharin, sugar alcohols, organic and amino acids, flavors and/or coloring agents.
The products are favorably usable as a low-cariogenic and low-calorie sweetener because it is less fermentable by oral dental-caries causative microorganisms. Exemplary applications include low-cariogenic food products such as confectioneries including chewing gum, chocolate, biscuits, cookies, toffee and candy. Additionally applications include soft drinks such as coffee, cocoa, juice, carbonated drinks, sour milk beverage, yoghurt drinks and alcoholic drinks, such as brandy, whisky, vodka and wine. In addition to the above-described uses, the sweeteners are usable for sweetening drugs and cosmetics.
The following examples illustrate preferred embodiments of the invention.
EXAMPLE 1
Extraction of Sweet Glycosides
The leaves of Stevia rebaudiana are dried at 55° C. for three hours in a vacuum oven and powdered (30 mesh). One kg of the obtained material was mixed with 10 liters of water (pH 6.5) and heated to 55° C. with slow agitation for 10 hours. The plant material was separated from the solution by filtration and the pH of the filtrate was adjusted to 10 with about 24 grams of calcium hydroxide and heated to 50° C. for 0.5 hours. The obtained mixture was cooled to ambient temperature and the pH was adjusted to about 7.0 by about 53 grams of FeCl 3 . After mixing for 15 minutes the precipitate was removed by filtration.
The slightly yellow filtrate was passed through the Celite, deionized, and decolorized by conventional manner on Amberlite FPC23H, Amberlite FPA51, and Amberlite FPA98Cl commercialized by ROHM & HAAS Co., Germany. The solution was concentrated and spray dried. The yield was 122 grams of powder with a content of sweet glycosides to about 91%. The mixture contains 3.4% Dulcoside, 64.6% Stevioside, 6.7% Rebaudioside C and 25.3% Rebaudioside A.
EXAMPLE 2
Preparation of Stevioside
100 grams (on the base of dry material) of the powder obtained by the process of EXAMPLE 1 was mixed with 0.5 liters of methanol and maintained at 25° C. for 45 minutes with slow agitation. The precipitate Stevioside was filtered and dried. 61.2 grams of Stevioside with 90.6% purity was obtained.
For the further purification the powder was mixed with two parts of 90% of ethanol, and maintained at 10-12° C. for about 30 minutes with slow agitation. The precipitate was separated by filtration and dried under vacuum. The product weighed 58.8 grams and contained 99.3% Stevioside.
EXAMPLE 3
Preparation of Rebaudioside A
The remaining solutions after separation of Stevioside (EXAMPLE 2) were combined, and methanol was removed by evaporation. The syrup was diluted with water and passed through polysulfone based ultrafiltration membranes (with a filtering discrimination of 2.5 kDa) (Liumar Technologies, Ottawa, Canada) with diafiltration. The filtrate was concentrated and spray dried. 40.8 grams of powder with content of Rebaudioside A of around 60% were obtained. The powder was mixed with five volumes (w/v) of 96.2% ethanol and maintained at 50° C. for 30 minutes with slow agitation. The precipitate was filtered and dried. Rebaudioside A with 89.8% purity was obtained. The powder was mixed with two volumes of 92% of ethanol and maintained at 12° C. for 60 minutes with slow agitation. The crystals were filtered and dried. 23.6 grams of Rebaudioside A of 98.9% purity was obtained.
EXAMPLE 4
Low-Calorie Orange Juice Drink
Orange concentrate (35%), citric acid (0.38%), ascorbic acid (0.05%), sodium benzoate (0.02%), orange red color (0.01%), orange flavor (0.20%), and sweetener (0.06%) containing 90.2, 95.4 or 99.3% of Stevioside, or 80, 90, or 98.9% of Rebaudioside A were blended and dissolved completely in the water (up to 100%) and pasteurized. The sensory evaluation of the samples is summarized in the TABLE 1. The data shows that best results were obtained for highly purified Rebaudioside A and Stevioside.
TABLE 1
Comments
Sample
Flavor
Aftertaste
Mouth feel
Stevioside -
Sweet and balanced flavor
Slight bitterness in
Acceptable
90.2%
aftertaste
Stevioside -
Sweet and balanced flavor
Slight bitterness in
Acceptable
95.4%
aftertaste
Stevioside -
Sweet, pleasant, balanced flavor
Clean, no bitterness
Quite full
99.3%
Rebaudioside
Sweet, rounded and balanced
Almost no any
Acceptable
A - 80.0%
flavor
bitterness
Rebaudioside
Sweet, rounded and balanced
Almost no any
Full
A - 90.0%
flavor
bitterness
Rebaudioside
High quality of sweetness,
Clean, no unpleasant
Quite full
A - 98.9%
pleasant, taste similar to
aftertaste
sucrose, balanced flavor
By the same way can be prepared juices from other fruits, such as apple, lemon, apricot, cherry, pineapple, etc.
EXAMPLE 5
Low-Calorie Carbonated Lemon-Flavored Beverage
The formula for the beverage was as below:
Ingredients
Quantity, kg
Sugar
30.0
Sweetener
0.4
Citric acid
2.5
Green tea extract
25.0
Salt
0.3
Lemon tincture
10.0
L
Juniper tincture
8.0
L
Sodium benzoate
0.17
Carbonated water
up to 1000
L
Sensory and physicochemical characteristics of the drink are presented in the TABLE 2.
The drinks with highly purified Rebaudioside A and Stevioside were superior with an excellent flavor and taste.
TABLE 2
Characteristics
Stevioside -
Rebaudioside
Rebaudioside
Item
Stevioside - 90.2%
99.3%
A - 90.0%
A - 98.9%
Appearance
Transparent liquid,
Transparent
Transparent
Transparent
free of sediment
liquid, free of
liquid, free of
liquid, free of
and strange
sediment and
sediment and
sediment and
impurities. A light
strange
strange
strange
opalescence, caused
impurities. A
impurities. A
impurities. A
by features of used
light
light
light
raw materials is
opalescence,
opalescence,
opalescence,
possible.
caused by
caused by
caused by
features of
features of
features of
used raw
used raw
used raw
materials is
materials is
materials is
possible.
possible.
possible.
Color
From light yellow up to
From light
From light
From light
yellow
yellow up to
yellow up to
yellow up to
yellow
yellow
yellow
Taste
Sour-sweet, some
Sour-sweet,
Sour-sweet,
Sour-sweet,
bitterness in
expression of
almost no any
expression of
aftertaste
sweetness is
bitterness,
sweetness is
rapid. The
expression of
rapid.
taste is
sweetness is
satisfactory.
rapid.
EXAMPLE 6
Low-Calorie Carbonated Drink
The formula for the beverage was as below:
Ingredients
Quantity, %
Cola flavor
0.340
Phosphoric acid (85%)
0.100
Sodium citrate
0.310
Sodium benzoate
0.018
Citric acid
0.018
Sweetener
0.030
Carbonated water
to 100
The beverages prepared with different sweeteners were given to 10 judges for comparison.
TABLE 3 shows the results.
TABLE 3
Number of panelists
Comparison
Stevioside -
Stevioside -
Rebaudioside A
Rebaudioside A
Point
90.2%
99.3%
90.0%
98.9%
Bitter taste
6
2
3
0
Astringent taste
6
2
3
0
Aftertaste
6
2
3
0
Quality of
Sweet,
Clean (7 of the
Sweet, some
Clean (10 of the
sweet taste
bitterness in
10 judges)
bitterness in
10 judges)
aftertaste (6 of
aftertaste (5 of
the 10 judges)
the 10 judges)
Overall
Satisfactory (5
Satisfactory (8
Satisfactory (8
Satisfactory (10
evaluation
of the 10
of the 10
of the 10
of the 10
judges)
judges)
judges)
judges)
The above results show that the beverages prepared using highly purified Stevioside and Rebaudioside A possessing good organoleptic characteristics.
EXAMPLE 7
Chocolate
A composition containing 30 kg of cacao liquor, 11.5 kg of cacao butter, 14 kg of milk powder, 44 kg of sorbitol, 0.1 kg of salt, and 0.1 kg of sweetener prepared according to the EXAMPLES 2 or 3, was kneaded sufficiently, and the mixture was then placed in a refiner to reduce its particle size for 24 hours. Thereafter, the content was transferred into a conche, 300 grams of lecithin was added, and the composition was kneaded at 50° C. for 48 hours. Then, the content was placed in a shaping apparatus, and solidified.
The products are low-cariogenic and low-calorie chocolate with excellent texture. Also, the organoleptic test carried out with 20 panelists revealed no lingering after-taste. The most desirable ones were the products with Rebaudioside-98.9% (19 members) and Stevioside 99.3% (16 members).
EXAMPLE 8
Ice-Cream
1.50 kg of whole milk were heated to 45° C., and 300 grams of milk cream, 100 grams of tagatose, 90 grams of sorbitol, 6 grams of carrageenan as a stabilizer, 3 grams of polysorbate-80 as an emulsifier, and 1.0 gram of sweetener prepared according to the EXAMPLES 2 or 3, were added into the milk and was stirred until the ingredients completely dissolved. The mixture then was pasteurized at a temperature of 80° C. for 25 seconds. The homogenization of the obtained mixture was carried out at a pressure of 800 bars and the samples were kept at a temperature of 4° C. for 24 hours to complete the aging process. Vanilla flavor (1.0% of the mixture weight) and coloring (0.025% of the mixture weight) are added into the mixture after aging. The mixture was then transferred to ice cream maker to produce ice cream automatically. Samples of ice creams produced were transferred to seal containers and were kept in the freezer at a temperature of −18° C.
The application of sweeteners does not affect the physicochemical properties of ice cream, as well as the overall attributes of color, smoothness, surface texture, air cell, vanilla aroma intensity, vanilla taste, chalkiness, iciness and melting rate. Organoleptic test carried out with 20 panelists. The most desirable ones were the products with 98.9% Rebaudioside A (18 members) and 99.3% Stevioside (14 members).
EXAMPLE 9
Yogurt
In 5 kg of defatted milk, 4.0 grams of sweetener, prepared according to EXAMPLES 2 and 3, were dissolved. After pasteurizing at 82° C. for 20 minutes, the milk was cooled to 40° C. A starter in amount of 150 grams was added and the mixture was incubated at 37° C. for 6 hours. Then, the fermented mass was maintained at 10-15° C. for 12 hours.
The product is a low-calorie and low-cariogenic yoghurt without foreign taste and odor.
EXAMPLE 10
Table Top Tablet
A mixture, consisting of 58.5% lactose, 10% calcium silicate, 5% cross-carmellose, 5% L-leucine, 1% aerosol 200, 0.5% magnesium stearate, and 20% of a sweetener, obtained according to the EXAMPLE 2 or 3, was kneaded sufficiently. Then the mixture was shaped with the use of a tabletting machine, equipped with punchers of 6.2 mm diameter, into tablets of 70 mg each, 3.0 mm thick, and 10±1 kg hardness
The tablets can be easily administrated due to their appropriate sweetness. However, the formulations using low grade of Stevioside and Rebaudioside A were somewhat sticky with solubility about 3-4 minutes in water at 25° C. The tablets, prepared with highly purified Rebaudioside A show the best characteristics with the solubility around 20-30 seconds.
EXAMPLE 11
Tooth Paste
A tooth paste was prepared by kneading a composition comprising of calcium phosphate, 45.0%; carboxymethylcellulose, 1.5%; carrageenan, 0.5%; glycerol, 18.0%; polyoxyethylene sorbitan mono-ester, 2.0%; beta-cyclodextrin, 1.5%; sodium laurylsarcosinate, 0.2%; flavoring, 1.0%; preservative, 0.1%; Rebaudioside A or Stevioside, obtained according to the EXAMPLE 2 or 3, 0.2%; and water to 100%, by usual way. The product possesses good foaming and cleaning abilities with appropriate sweetness.
EXAMPLE 12
Soy Sauce
0.8 g of Rebaudioside A/Stevioside mixture (1:1, w/w) obtained according to the invention was added to 1000 mL of soy sauce and mixed homogenously. The products had an excellent taste and texture.
EXAMPLE 13
Bread
1 kg of wheat flour, 37.38 grams of fructooligosaccharide syrup, 80 grams of margarine, 20 grams of salt, 20 grams of yeasts, and 0.25 grams of high purity Rebaudioside A or Stevioside, obtained according to the EXAMPLE 2 or 3 were placed into the blender and mixed well. 600 ml of water was poured into the mixture and kneaded sufficiently. At the completion of the kneading process, the dough was shaped and raised for 30 to 45 minutes. The ready dough was placed in oven and baked for 45 minutes. Bread samples had creamy white color, and smooth texture.
EXAMPLE 14
Diet Cookies
Flour (50.0%), margarine (30.0%), fructose (10.0%), maltitol (8.0%), whole milk (1.0%), salt (0.2%), baking powder (0.15%), vanillin (0.1%), Rebaudioside A or Stevioside (0.55%), obtained according to this invention were kneaded well in dough-mixing machine. After molding of the dough the cookies were baked at 200° C. for 15 minutes.
The product is a low-calorie diet cookie with excellent taste and appropriate sweetness.
EXAMPLE 15
Cake
123 g of hen eggs, 45 g of sugar, 345 g of sorbitol liquid, 2.0 g of sucrose fatty acid ester, 0.35 g of Rebaudioside A or Stevioside was mixed with 100 g of wheat flour and 200 g of water in order to prepare a cake according to a conventional method. The product had an excellent taste with an optimal sweet flavor.
It is to be understood that the foregoing descriptions and specific embodiments shown herein are merely illustrative of the best mode of the invention and the principles thereof, and that modifications and additions may be easily made by those skilled in the art without departing for the spirit and scope of the invention, which is therefore understood to be limited only by the scope of the appended claims. | Highly purified Stevioside and Rebaudioside A were prepared from sweet glycoside extracts obtained from Stevia rebaudiana Bertoni leaves. The resulting sweeteners are suitable as non-calorie, non-cariogenic, non-bitter, non-lingering sweeteners, which may be advantageously applied in foods, beverages, and milk products. | 0 |
CROSS-RELATED TO OTHER APPLICATIONS
This is a National Stage filing of PCT/US95/10920 under 35 U.S. C. §371 and a continuation of 08/299,872, filed Sep. 1, 1994, now abandoned.
FIELD OF THE INVENTION
The present invention relates to the brain-specific expression of the Familial Alzheimer's disease (V-I) variant of the human amyloid precursor protein in transgenic mice.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . Schematic representation of the 7.1 kb Eco RI-Xba I fragment encoding the human Thy-1 promoter, the human APP 751 FAD (V-I) cDNA and SV40 derived 3′ flanking sequences. Relevant regions of the APP including the signal peptide (Sp), Kunitz protease inhibitor (KPI) and βA4 domains and the position of the V-I FAD mutation are indicated. The position of primers is shown by arrows. The primers were employed across the 66 bp SV40 small t intron (indentation in the physical map) to amplify a 319 bp fragment from the APP 751 FAD mRNA by RT-PCR.
FIG. 2 . RNA analysis of APP 751 FAD founders. Upper panel: Northern blot analysis of APP 751 FAD transgenic (Tg) and age-matched, non-transgenic (NTg) F1 mice. Samples (about 4 μg) of poly A + mRNA from brain (B), kidney (K) and intestine (I) were resolved on a MOPS formaldehyde gel and transferred to a nylon membrane. The RNA was hybridized with 32 p labeled transgene specific SV40 sequences. Predominant brain-specific expression was seen in line 14.2 F1 transgenic animals. Line 7.2 and Line 9.3 transgenic animals exhibited a lower level of expression. Bottom panel: The Northern blot was hybridized with a 32 p labeled β-actin probe and the relative amount of poly A + mRNA loaded in the different lanes was estimated.
FIGS. 3 (A-B). RT-PCR analysis of APP751 FAD. One microgram of total RNA from various tissues of a perfused transgenic animal (line 14.2) was reverse transcribed and subsequently amplified using AmpliTaq DNA polymerase. The amplified products were resolved on a 0.8% agarose gel, blotted to a nylon membrane, and hybridized with SV40 sequences. Predominantly APP 751 mRNA expression was found in brain and while expression was negligible in most other tissues.
FIGS. 4 (A-L). Localization of APP 751 FAD RNA by in situ hybridization. Computer-generated pseudo-color images of representative in situ hybridization X-ray film autoradiograms show expression of human APP 751 FAD mRNA in various brain areas of the transgenic mice. The 14.2 line (rostral to caudal; labeled A, B, C); the 9.3 line (E, F, G); and the 7.2 line (I, J, K). The highest level of mRNA expression was found in the brains of mice belonging to the 14.2 line with expression throughout the brain, but was particularly dense in the cortex (C) and hippocampus (h). High mRNA levels were also found in the amygdala (am), the superficial layers of the superior colliculus (sc) and the central grey (cg). Lower levels of expression were found in other areas, e.g., in the hypothalamus-medial preoptic area (mpo) and arcuate nucleus (arc), the lateral septum (ls) and caudate putamen (cp). When brain sections were taken from the 14.2 line (D), the 9.3 line (H) and the 7.2 line (L) and hybridized with 35 S labeled control ‘sense’ probe (complementary to the ‘antisense’ probe), mRNA signals could not be obtained, showing the specificity of the RNA signals obtained with the labeled antisense human APP 751FAD mRNA probe.
FIG. 5 . APP 751 (V-I) protein analysis by Western blotting. Western blotting of brain protein lysates from different transgenic animals (91-95) and non-transgenic control animals (96, 97) with a human-specific antibody (Ab) 6E10 (Kim et al., (1990) Neurosci. Res. Commun. 7, 113-122; Kim et al., (1988) Neurosci Res. Commun. 2, 121-130). The top panel shows reactivity with the 6E10 Ab; the middle panel shows reactivity with CT15 Ab; recognizing human and mouse APP; and the bottom panel shows reactivity with a β-tubulin control Ab. Animal 95 (line 14.2 transgenics) expresses a large quantity of APP 751 protein at levels comparable to the 500 kb YAC derived human APP protein expressed in mice (labeled YAC; Lamb et al., (1993) Nature Genetics 5, 22-30). N+O in the CT15 panel represents the fully modified, glycosylated 751 protein in the line 95 animals. Line 9.3 and 7.2 animals (91, 92 and 93, 94, respectively) had lower levels of APP protein.
FIGS. 6 (A-B). APP751 FAD expression in mouse brain. Brains from transgenic mice that overexpress the human APP gene were analyzed. Using a monoclonal antibody to the N-terminal end of human APP (Clone 22C11, Boehringer Mannheim; dilution 1:20), intensely immunoreactive neurons were found in the cortex and hippocampus in the brains of APP751 FAD transgenic 14.2 founder (18 months old). Non-transgenic control (15 month old) did not show this staining pattern. The intensity of the staining appeared to be age-related. This accumulation of APP immunoreactivity in neurons of the transgenic mice appeared to be granular and deposit-like in appearance.
FIG. 7 . The 43 amino acid β-A4 domain of FAD APP 751 is shown in bold. The V-I substitution is boxed. The nucleotide sequence in this figure is SEQ ID NO:6 and the amino acid sequence is SEQ ID NO:7.
BACKGROUND OF THE INVENTION
Alzheimer's disease (AD) is a neurological disorder that disproportionately affects the population over 65 years of age. Incidence of the disease increases from less than 1% at age 60-65, to 5% at age 75, to as high as 47% at age 85. Between, 60% to 80% of all cases of dementia in persons over age 65 are caused by AD. Afflicted individuals exhibit impaired cognitive function and memory. Neither a suitable diagnostic procedure nor an effective therapeutic treatment exists for AD. Positive identification of AD requires biopsy or autopsy of the brain.
Although the etiology of AD is unknown, genetic, immunological and environmental factors have been implicated in the development of AD. Distinguishing features of AD include the presence of senile plaques as well as, neurofibrillary tangles and extensive neuronal loss in the neocortex, hippocampus and associated structures. Senile plaques consist of extracellular deposits containing a β-amyloid core surrounded by a halo of dystrophic neurites, glia and astrocytes. β-amyloid deposits are present in neocortex blood vessel walls. The major component of senile plaques is a 4 kDa peptide referred to as βA4, that is proteolytically cleaved from a larger 120 kDa amyloid precursor protein (APP). Other components of the plaques include ubiquitin, amyloid P, Apo E, interleukin-1, and α-1-antichymotrypsin.
In addition to biochemical evidence supporting βA4 involvement in AD, there are strong genetic data which suggest a link between APP and AD. A clue to the location of a gene involved in AD comes from analysis of Down syndrome patients; in these patients trisomy of chromosome 21 is responsible for the early onset of AD. Karyotype analysis of Down syndrome patients mapped the gene involved to the upper portion of the long arm of chromosome 21. The region involved encodes several genes, including the APP gene. The early onset (˜ age 35) of AD in Down syndrome patients suggests that an increase in the gene dosage of the responsible marker(s) on the long arm of chromosome 21 may contribute to the neuropathology noticed in most AD patients.
Although the majority of AD cases appear sporadic, several cases of early onset familial AD (FAD) have been reported. Genetic analysis of FAD families has established that the disorder is inherited as a dominant autosomal gene defect, which maps to the long arm of chromosome 21 and is closely linked to the APP gene. These findings are consistent with genetic data obtained from the analysis of Down syndrome patients. Several FAD families have also been identified in which an early onset of AD is strictly correlated with the presence of a mutation in exon 17 of the APP gene at amino acid 717 (Val-Ile). This mutation within the transmembrane spanning domain of the APP co-segregates with FAD. Since the families afflicted with APP717 FAD are of different ethnic origins (English, Japanese and Canadian), evidence for the involvement of the FAD gene in these cases of AD is strong. The mutation is absent from control individuals, in sporadic AD patients, in Down syndrome patients, in late onset familial AD, and also in most other cases of early onset FAD. Several additional mutations in the APP gene have been identified that can explain the occurrence of AD in other FAD families. The genetic evidence in the five distinct early onset APP 717 FAD families strongly supports the hypothesis that the APP 717 gene in these FAD families is directly positioned in the pathway of AD progression.
The APP gene is approximately 400 kb in length and encodes a glycosylated, transmembrane protein which may be involved in cell-cell interaction. The APP gene has at least 19 exons that create at least 5 distinct APP transcripts by alternative splicing. The predominant transcripts encode proteins of 695, 751 and 770 amino acids (these major forms of APP are referred as APP 695, APP 751 and APP 770, respectively). Transcripts for APP 695 are enriched in the brain. Transcripts encoding APP 751 and APP 770 mRNA species predominate in peripheral tissues. All three isoforms contain the 42 amino acid βA4 domain. APP isoforms 751 and 770 contain an additional 56 amino acid insert encoding the kunitz type serine protease inhibitor (KPI). APP is proteolytically metabolized by at least two pathways. One pathway involves an α-secretase cleavage site positioned between Lys 16 and Leu 17 of βA4 domain; proteolytic cleavage at this site precludes the formation of amyloidogenic βA4 entity. The second pathway produces intact, amyloidogenic βA4 (39-42 amino acids) by proteolytic cleavages at the β- and γ-secretase cleavage sites of the full-length APP molecule.
The βA4 laden senile deposits seen in AD patients are also found in aged humans and other aged mammals including non-human primates, polar bears and dogs. However, other aged mammals, such as laboratory rats and mice, do not normally develop βA4 deposits. The lack of a cost-effective, experimental animal model mimicking human pathogenesis hinders the understanding AD neuropathology and developing therapeutics against AD. Transgenic technology may offer a suitable alternative to this problem. Addition of a gene construct directing high levels of human APP or its components to key regions in the murine central nervous system may cause neuropathological changes resembling the AD phenotype. Although it may not be possible to produce all aspects of human AD together in a transgenic rodent model, significant aspects of the disease are likely to be produced in an appropriate transgenic animal model.
Accordingly, it is an object of the present invention to provide a transgenic mouse which exhibits neuropathology due to the overexpression of the human FAD APP 751 (V-I) isoform. The FAD APP 751 (V-I) isoform is specifically overexpressed in the brain of patients with familial AD and, therefore, represents a useful and novel model, distinct from those established by others. The transgenic mice of the present invention are useful in the identification of new targets in AD since the progression of the disease can be followed gradually. The mice of the present invention may be used in the identification of compounds that affect the role of FAD APP 751 (V-I) in neuronal dysfunction and compounds that affect formation of βA4 precipitates and/or βA4 function. It is expected that the amino acid substitution in the FAD APP (V-I) protein alters the normal function of the APP protein, thus precipitating early onset AD. Altered APP processing and/or an altered APP function in the mutant protein may thus be responsible for FAD in these cases.
Attempts to express human amyloid precursor protein segments or the full-length wild type protein in transgenic animals have been successful. Numerous reports exist outlining expression of different wildtype, full-length and truncated APP cDNA isoforms in mouse (Kammesheidt et al., (1992) Proc. Natl. Acad. Sci ., 89, 10857-10861; Sandhu et al., (1991) J. Biol. Chem ., 266, 21331-21334; Quon, et al., (1991) Nature , 352, 239-241; Wirak et al., (1991) Science , 253, 323-325; Kawabata et al., (1991) Nature 354, 476-478; Patent, International publication number WO93/02189, Neve, R., Inventor). However, these previous attempts to generate transgenic mouse models for AD have essentially failed. One of the main issues has been that in none of these publications researchers have reproducibly identified: i) a high level expression of full-length recombinant human APP protein expressed from cDNA constructs in mouse brain; ii) APP protein deposits in brain; or iii) neuropathology (Jucker et al., (1992) Science , 255, 1443-1445; Wirak et al., (1992) Science , 255, 1445; Marx, (1992) Science 255, 1200-1202; Kawabata, et al., Nature (1992) 356, p 23).
Overexpression of the APP 751 (V-I) cDNA representing a familial (APP 717 ) form of AD using a strong neuronal-specific promoter has not been attempted by others and is a unique aspect of the animal model described herein. The mouse of the present invention differs from others in that it shows a high steady state expression of APP 751 FAD protein by Western blotting, a unique distribution of APP mRNA in the central nervous system by in situ hybridization, and a unique deposition of intraneural protein APP FAD aggregates. These characteristics of the invention in combination with the identification of neuronal βA4 immunoreactive aggregates extend beyond previous claims in this area of research. Because of the early onset of FAD, this disease differs from late life AD. The model presented here will therefore represent unique aspects of AD.
SUMMARY OF THE INVENTION
A transgenic mouse with brain-specific expression of the familial form of the APP 751 isoform with a valine to isoleucine substitution at amino acid 698 (APP 751 isoform numbering; previously introduced as APP 717 based on APP 770 isoform numbering) is provided. The transgenic mouse of the invention may be used in the study of AD and disorders involving the central nervous system.
DETAILED DESCRIPTION OF THE INVENTION
A transgenic mouse with brain-specific expression of the familial form of the APP 751 isoform with a valine to isoleucine substitution at amino acid 698 (APP 751 isoform numbering; previously introduced as APP 717 based on APP 770 isoform numbering) is provided. The transgenic mouse of the invention may be used in the study of AD and disorders involving the central nervous system.
The term “animal” is used herein to include all vertebrate animals, except humans. It also includes an individual animal in all stages of development, including embryonic and fetal stages. A “transgenic animal” is an animal containing one or more cells bearing genetic information received, directly or indirectly, by deliberate genetic manipulation at a subcellular level, such as by microinjection or infection with recombinant virus. This introduced DNA molecule may be integrated within a chromosome, or it may be extra-chromosomally replicating DNA. The term “germ cell-line transgenic animal” refers to a transgenic animal in which the genetic information was introduced into a germ line cell, thereby conferring the ability to transfer the information to offspring. If such offspring in fact possess some or all of that information, then they, too, are transgenic animals.
The information may be foreign to the species of animal to which the recipient belongs, foreign only to the particular individual recipient, or genetic information already possessed by the recipient. In the last case, the introduced gene may be differently expressed compared to the native endogenous gene.
The genes may be obtained by isolating them from genomic sources by preparation of cDNAs from isolated mRNA templates, by directed synthesis, or by some combination thereof.
To be expressed, the structural gene must be coupled to a promoter in a functional manner. Promoter/regulatory sequences may be used to increase, decrease, regulate or designate to certain tissues or to certain stages of development the expression of a gene. The promoter need not be a naturally occurring promoter. In the preferred embodiment of the invention, the human Thy-1 (hThy-1) promoter is used. The hThy-1 promoter preferentially allows expression of the gene of interest within the brain (Gordon, J. et al., (1987) Cell , 50, 445-452).
The “transgenic non-human animals” of the invention are produced by introducing “transgenes” into the germline of the non-human animal. The methods enabling the introduction of DNA into cells are generally available and well-known in the art; however, the generation of a particular type of transgenic animal requires experimentation. Different methods of introducing transgenes could be used. Generally, the zygote is the best target for microinjection. In the mouse, the male pronucleus reaches the size of approximately 20 μm in diameter, which allows reproducible injection of 1-2 pL of DNA solution. The use of zygotes as a target for gene transfer has a major advantage, in most cases, the injected DNA will be incorporated into the host gene before the first cleavage (Brinster, et al., (1985) Proc. Natl. Acad. Sci. USA 82, 4438-4442). Consequently, nearly all cells of the transgenic non-human animal will carry the incorporated transgene. Generally, this will also result in the efficient transmission of the transgene to offspring of the founder since 50% of the germ cells will harbor the transgene. Microinjection of zygotes is the preferred method for incorporating transgenes in practicing the invention.
Retroviral infection can also be used to introduce a transgene into a non-human animal. The developing non-human embryo can be cultured in vitro to the blastocyst stage. During this time, blastomeres may be targets for retroviral infection (Jaenich, R. (1976) Proc. Natl. Acad. Sci. USA 73, 1260-1264). Efficient infection of the blastomeres is obtained by enzymatic treatment to remove the zona pellucida (Hogan et al., (1986) in Manipulating the Mouse Embryo, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.). The viral vector system used to introduce the transgene is typically a replication-defective retrovirus carrying the transgene (Jahner et al., (1985) Proc. Natl. Acad. Sci. USA 82, 6927-6931; Van der Putten et al., (1985) Proc. Natl. Acad. Sci. USA 82, 6148-6152). Transfection is easily and efficiently obtained by culturing the blastomeres on a monolayer of virus-producing cells (Van der Putten, supra; Stewart et al., (1987) EMBO J . 6: 383-388). Alternatively, infection can be performed at a later stage. Virus or virus-producing cells can be injected into the blastocoele (Jahner et al., (1982) Nature 298: 623-628). Most of the founder animals will be mosaic for the transgene since incorporation occurs only in a subset of the cells which formed the transgenic non-human animal. Furthermore, the founder animal may contain retroviral insertions of the transgene at a variety of positions in the genome; these generally segregate in the offspring. In addition, it is also possible to introduce transgenes into the germ line, albeit with low efficiency, by intrauterine retroviral infection of the midgestation embryo (Jahner et al., (1982) supra).
A third type of target cell for transgene introduction is the embryonal stem cell (ES). ES cells are obtained from pre-implantation embryos cultured in vitro (Evans, M. J., et al., (1981) Nature 292, 154-156; Bradley, A., et al., (1984) Nature 309, 255-258; Gossler, et al., (1986) Proc. Natl. Acad. Sci. USA 83, 9065-9069; and Robertson, et al., (1986) Nature 322, 445-448). Transgenes can be efficiently introduced into ES cells by DNA transfection or by retrovirus-mediated transduction. The resulting transformed ES cells can thereafter be combined with blastocysts from a non-human animal. The ES cells colonize the embryo and contribute to the germ line of the resulting chimeric animal (For review see Jaenisch, R. (1988) Science 240, 1468-1474).
The methods for evaluating the presence of the introduced DNA as well as its expression are readily available and well-known in the art. Such methods include, but are not limited to DNA (Southern) hybridization to detect the exogenous DNA, polymerase chain reaction (PCR), polyacrylamide gel electrophoresis (PAGE) and Western blots to detect DNA, RNA and protein. The methods include immunological and histochemical techniques to detect amyloid precursor protein and pathology associated with Alzheimer's disease.
As used herein, a “transgene” is a DNA sequence introduced into the germline of a non-human animal by way of human intervention such as by way of the methods described below.
A potential therapeutic compound for AD may be detected by measuring its capacity to block the neurodegenerative effect of APP, to block expression of APP, or to evaluate neurotrophic or other neuronally active compounds in these transgenic mice possibly in combination with different genetic backgrounds or transgenes, providing other susceptibility markers (i.e., cytokines, apolipoprotein overexpression and knock out, protease inhibitors, serum amyloid protein, NGF receptor protein, and prion protein transgenic mice). Such compounds will be formulated in accordance with known methods to produce pharmaceutically acceptable compositions. Such compositions may be administered to patients in a variety of standard ways.
The following is presented by the way of examples and is not to be construed as a limitation on the scope of the invention:
EXAMPLE 1
Construction of Human APP 751 FAD Expression Vector Using the Neuronal-specific Human Thy-1 Promoter
A. Construction of pHZ024, a Plasmid Containing Human Thy-1 and SV40 Sequences
A 3.7 kb Eco RI-Bgl II fragment of pBSHT1 containing the human Thy-1 promoter and the ATG translation initiation codon of the the Thy-1 gene was cloned into the Eco RI-Bam HI site of pTZ18u to generate pHZ020. We needed to remove the ATG translation initiation codon derived from the Thy-1 gene, allowing the ATG from any new coding sequence that we wished to introduce, downstream of the Thy-1 promoter to encode the first translation initiation start site. Therefore, a 1.6 kb Bam HI-Bgl 11 fragment of pBSHT1 (encoding the ATG translation initiation codon) was subcloned into the Bam HI site of pTZ18u to generate pHZ021a. To silence the initiation codon and to add convenient cloning sites, PCR amplification was carried out using pHZ021a as template and 20-mer (T7; 5′ primer) and 73-mer (oHZ002; 3′ primer with disrupted ATG and several convenient cloning sites) oligonucleotides. In primer oHZ002 the ATG translation initiation codon has been mutated and replaced with a Hind III restriction enzyme site (see sequence given below; the Hind III restriction enzyme site is outlined in bold; mutated residues are underlined).
T7 :
5′TAATACGACTCACTATAGGG (SEQ ID NO: 1).
oHZ002:
5′ACGTCGACTCTAGAAGATCTTCGACTCGAGATCGATGGTACCCGGGCAGGTT-
C A A G C TT CTGGGATCTCAGTC (SEQ ID NO: 2).
CAT GGTTCTGGGATCTCAGTC (unaltered strand)
Incorporation of the underlined residues in the 1.3 kb amplified product destroyed the ATG (CAT in the unaltered complimentary strand, shown in italics) but created a Hind III site (in bold letters). The modified Thy-1 promoter was reconstituted by ligating 0.3 kb Nco I-Xba I fragment of the 1.3 kb amplified product into Nco I-Xba I digested pHZ020. The resulting vector is designated pHZ022.
SV40 sequences were inserted into this plasmid downstream of the Thy-1 promoter in a two step procedure; first, by inserting a Bgl II linker at the Sma I restriction enzyme site upstream of the SV40 small t intron of pSV2neo (pHZ023; Southern and Berg, (1982) Mol, Appl. Genet. 1:327) and second by isolating the 1.0 kb Bgl II-Bam HI containing SV40 small t intron and polyadenylation site and ligating it to the Bgl II digested pHZ022. In the resulting plasmid, pHZ024, the neuronal specific human Thy-1 promoter is separated from the SV40 sequences by a multi-purpose cloning site, permitting the insertion of desired gene(s) or their segments.
B. Construction of APP 751 FAD Expression Vector, p4
A 2.7 kb Sma I-Cla I restriction fragment encoding the full-length human APP 751 cDNA with the late onset FAD mutation (V-I) was obtained by restriction enzyme digestion of plasmid DA-12 (a gift of Drs. N. Robakis of Mount Sinai School of Medicine and R. Swanson of MRL, West Point). The ends of the Sma I-Cla I restriction enzyme fragment were made blunt with the Klenow fragment of DNA polymerase I. This fragment was ligated into pHZ024 (pHZ024 was digested with Xho I and the Xho I site was made blunt using the Klenow fragment of DNA polymerase I). The human APP 751 cDNA (V>I) was thus placed under the control of the hThy-1 promoter, flanked at its 3′ end by the SV40 small t intron and poly A addition site. The resulting plasmid is referred to as p4. The nucleotide sequence of the coding sequence of the APP 751 cDNA insert of plasmid p4 was entirely confirmed to assure that the entire amino acid sequence was as predicted and a full-length polypeptide would be expressed. A 79 bp deletion in the 3′ non coding extension of the mRNA of APP 751 was noted. For microinjection into zygotes, the p4 expression vector was purified on a CsCl gradient and was digested at a unique Xba I restriction enzyme site and partially restriction enzyme digested with Eco RI to obtain a 7.1 kb fragment, T-APP751 FAD, which does not contain flanking plasmid sequences. The 7.1 kb fragment was purified on a preparative 1% low melting point agarose gel containing 10 ng/ml ethidium bromide. The DNA was visualized using minimal exposure to short-wave UV light and the 7.1 kb band was excised, melted at 65-70° C., phenol/chloroform extracted twice, chloroform extracted once and ethanol precipitated in 0.3 M sodium acetate (pH 5.2) and filtered through a pre-rinsed 0.2 μm cellulose acetate filter. The purified 7.1 kb linear DNA containing the human Thy-1 promoter linked to the human APP 751 FAD cDNA and SV40 small t intron and poly A addition sequences was subsequently microinjected (FIG. 1 ).
All restriction endonucleases and DNA modifying enzymes were from Boehringer Mannheim, Inc. DNA sequencing was performed using either Sequenase (U.S. Biochemical, Inc.) or a double stranded DNA Cycle Sequencing Kit (BRL, Inc.). Oligodeoxynucleotides were synthesized on ABI DNA Synthesizer model #381A. PCR was according to Perkin-Elmer, Corp.
EXAMPLE 2
Production of Transgenic Mice Containing Human Amyloid Precursor Protein Under Regulation of the Human Thy-1 Promoter
The p4 DNA construct of Example 1 containing the human APP 751 FAD cDNA under the control of the human Thy-1 promoter was microinjected into the pronucleus of one-cell fertilized mouse embryos obtained from superovulated B6SJL females. The optimal concentration of the DNA used for microinjection was the LD 50 value derived empirically from toxicity test experiments using several dilutions of the gene construct microinjected into mouse embryos. This LD50 value came out to be 7.5×10 −9 μg. The embryos injected with 7.5×10 −9 μg DNA were then surgically reimplanted into the oviducts of pseudopregnant recipient mice and allowed to develop to term. At three to four weeks, postnatal tail samples were taken by clipping approximately 1 cm of the tail for DNA (Southern) blot analysis to determine the presence of the transgene. Necropsies and/or biopsies were performed to collect tissue specimens for histological and expression studies.
EXAMPLE 3
Analysis of Transgenic Mice
A. DNA Analysis
Genomic DNA extracted from tail samples using a Proteinase-K lysis method was quantitated by DNA fluorometry. Approximately 7 mg of genomic DNA was digested with the restriction enzyme Bam HI, size separated on a 0.8% agarose gel, after which the DNA was transferred to a nylon membrane by Southern blotting. The filters were hybridized with transgene-specific 32 p labeled SV40 sequences. Hybridization was conducted at 65° C. in 6×SSC, 5× Denhardt's reagent, 50% Dextran sulphate, 1.2% SDS, 100 mg/ml denatured, sonicated salmon sperm DNA, and 0.1 M Tris (pH 7.4). Post-hybridizational washes were performed in 2×SSC, 1% SDS for 15 minutes at room temperature followed by serial washes 65° C. in 2×SSC, 1% SDS for 2-3 hours. The filters were exposed to X-ray film at −70° C. with an intensifying screen for up to five days. Transgene copy number was determined on 7 μg of genomic DNA from transgenic offspring with known quantities of the linearized p4 vector co-migrated in the same agarose gel. The probe used was able to detect as little as 0.1 copies of the transgene in the murine genome. Appropriate transgenic founders were bred to produce offspring. Three transgenic founders were numbered 7.2, 9.3 and 14.2. The transgene copy number in these three founders ranged from 1-5 in the F1 progeny of the 7.2 and 14.2 founders, and 6-10 for the F1 progeny of the 9.3 founder.
B. RNA Analysis
Total RNA was isolated from mouse tissues including brain, liver, lung, kidney, spleen, intestine, heart, thymus, and skeletal muscle by the method of Chomczynski and Sacchi ( Anal. Biochem . (1987) 162, 156-159). Poly A + mRNA was purified from total RNA using mini-oligo (dT) cellulose spin column kit with methods as outlined by the suppliers (5 Prime>3 Prime Inc.®). Approximately 4 μg of poly (A) + mRNA was resolved on a MOPS-formaldehyde gel at 5 Volts/cm for 3-4 hours at room temperature with constant recirculation of the buffer. At the end of the run, RNA was visualized by ethidium bromide staining. Following staining, the gel was repeatedly rinsed in DEPC treated water to remove excess formaldehyde. To assure efficient transfer of the RNA, the gel was soaked in 50 mM NaOH and 10 mM NaCl for 20 minutes and neutralized in 100 mM Tris-HCl (pH 7.5) for 30 minutes. Finally, the RNA was transferred to a nylon membrane in 20×SSC. To identify the APP 751 FAD transgenic transcripts, the filter was hybridized with transgene-specific SV40 sequences. At least a 10-fold increase in the APP 751 RNA expression levels in the brain of the 14.2 transgenic line was observed in comparison to the other transgenic samples, while control brain samples never showed expression of the transgenes (FIG. 2 ). In addition, APP transgene expression could not be detected in other tissues from the transgenic animals suggesting neuronal-specific expression of the hThy-1 promoter. The ability to detect the APP 751 cDNA in Northern blot analysis indicates that the RNA is abundantly expressed in the central nervous system. Previous reports relied on reverse transcriptase PCR technology, presumably due to the low level of expression of the transgene.
C. RT-PCR
A reverse transcription polymerase chain reaction (RT-PCR) assay for rapidly analyzing the transgenic mRNA in the APP transgenic animals was also used analyzing total RNA isolated from different tissues for FAD APP 751 expression. To avoid contamination of the tissue with blood, total RNA for RT-PCR analysis was prepared from saline perfused transgenic animals. At least 1 μg of total RNA was reverse transcribed at 42° C. in the presence of human placental RNase inhibitor. PCR amplification was performed in the presence of the 519-5 (CGGGCTCTCCTGATTATITATCT; SEQ ID NO: 3) and 519-3 primers (AAAGGCATTCCACCA CTGCT; SEQ ID NO: 4) and components of GeneAmp®RNA PCR Kit (Perkin Elmer Cetus Instruments) according to the manufacturers instructions. The primers (FIG. 1, arrows below the physical map) were designed across the 66 bp small t intron (FIG. 1; indentation in physical map) to differentiate amplification of the spliced mRNA from intron containing DNA that might contaminate the RNA preparation and to discriminate RNA precursor transcripts from mRNA. The amplification profile included a 2 minute incubation at 95° C. for 1 cycle; 1 minute at 95° C. and 1 minute at 60° C. for 35 cycles and a 7 minute extension cycle at 60° C. Amplifications were carried out in a Bios thermal cycler. The PCR products were resolved on a 1.5% agarose gel in a Tris Acetate-EDTA buffer and transferred to a nylon membrane and hybridized with SV40 sequences (FIG. 3 ). An expected RNA derived 319 bp fragment was generated in brain samples from the F2 progeny of all three independently generated transgenic lines (7.2, 9.3 and 14.2; only line 14.2 results are shown in FIG. 3 ). Amplification signals could not be observed with RNA from a non-transgenic control brain sample.
D. In situ Hybridization
The animals were euthanized, the brains quickly removed under aseptic conditions and immediately frozen in isopentane on dry ice at −35° C. and stored at −70° C. Coronal or sagittal sections˜10 μm) were then cut in a cryostat (Reichert) at −18° C. to −20° C. Sections were thaw mounted on “Probe On” slides (Fisher Scientific), air-dried thoroughly (approximately 1 h), fixed in 4% paraformaldehyde in 0.1 M phosphate buffered saline (PBS; pH7.4) for 5 min., rinsed in PBS for 2 min., delipidated and dehydrated in an ethanol series (50, 70 and 95%) (5 min. each and stored in 95% ethanol at +4° C.).
The ‘antisense’ oligonucleotide probe specific for the human APP 751 mRNA was 40 bases long and was complementary to bases 1138-1177 of the human APP gene (5′-ACT GGC TGC TGT TGT AGG AAT GGC GCT GCC ACA CAC GGC C -3′; SEQ ID NO: 5) (Ponte et al., (1988), Nature , 331, 525-527). It was synthesized on an Applied Biosystems DNA synthesizers (Model 394) and purified on a 8% polyacrylamide/8M urea preparative sequencing gel. When used in in situ hybridization experiments, this probe gave hybridization signal for APP 751 in human and monkey brain sections, but not in mouse brain sections, indicating its specificity for human APP 751 (no cross hybridization with mouse APP 751).
The APP 751 probe was 3′-end labeled with [ 35 S]deoxyadenosine 5′-(α-thiotriphosphate) ([ 35 S]dATP) (1415 Ci/mMol) (New England Nuclear) in a 30:1 molar ratio of [ 35 S]dATP:oligonucleotide using terminal deoxynucleotidyl transferase (25 units; Boehringer Manheim) for 15 min. at 37° C. in reaction buffer containing 1 M potassium cacodylate, 125 mM Tris-HCl, 1.25 mg/ml bovine serum albumin (pH 6.6) and 25 mM cobalt chloride. Radiolabeled oligonucleotide was separated from unincorporated nucleotides using Sephadex G50 spin columns; 2 μl of 1 M dithiothreitol (DTT) was added to the eluate to prevent cross linking of sulfur residues. The specific activities of the labeled APP 751 oligonucleotide probe in several labeling reactions varied from 1.2-2.3×10 9 cpm/μg.
Hybridizations of mouse brain sections were carried out essentially as previously described (Sirinathsinghji et al., (1990), Neuroscience , 34, 675-686; Sirinathsinghji and Dunnett (1993), In Molecular imaging in neuroscience (Ed. Sharif, NA), 43-70). Briefly, sections were removed from the alcohol, air-dried for about 1 h and incubated with 0.4-1.0×10 6 cpm of 35S labeled probe in 100 ml hybridization buffer containing 50% deionized formamide, 4× saline sodium citrate (SSC), 5× Denhardt's, 200 μg/ml acid-alkali denatured salmon sperm DNA, 100 μg/ml long chain polyadenylic acid, 25 mM Sodium phosphate pH7.0, 0.1 mM sodium pyrophosphate, 10% dextransulphate, and 40 mM DTT.
To define non-specific hybridization, adjacent slide mounted sections were incubated with labeled oligonucleotide probe in the presence of an excess (×00) concentration of unlabeled oligonucleotide probe or with a sense probe from the same region. Parafilm coverslips were gently placed over the sections which were then put in humidified containers and incubated overnight (about 16 h) at 37° C. Following hybridization, the sections were washed for 1 h in 1×SSC at 57° C. and then rinsed briefly in 0.1×SSC, 70% and 95% ethanol, air-dried and then exposed to Amersham Hyperfilm, β-max X-ray film for 2-17 days.
In situ hybridization was performed on sections from 3 animals from the 14.2 founder (14.2.5.13, 14.2.3.25 and 14.2.3.57) and two control non-transgenic litter mates (14 2.5.12 and 14.2.3.26) and animals from transgenic lines 7.2 and 9.3 and their non-transgenic littermates. Autoradiograms (2-day-exposure) of hybridized sections from all three transgenic animals showed dense homogeneous APP751 mRNA expression throughout the brain. Expression was particularly abundant in all cortical areas (prefrontal, cingulate, frontal, occipital, piriform) hippocampus (dentate gyrus, CA3, CA2, CA1 fields and amygdala). Dense but comparatively less expression was found in the septum, caudate-putamen and thalamus (FIG. 4 ). The specificity of the mRNA signal was confirmed by results showing that (1) adjacent sections from the three transgenic animals hybridized with labeled oligonucleotide in the presence of 100-fold excess of unlabeled oligonucleotide gave no hybridization signal and (2) sections from control non-transgenic animals (14.2.3.26 and 14.2.5.12) hybridized with labeled oligonucleotide probe gave no hybridization signal in any brain areas and (3) hybridization with the sense probe gave no detectable signal (FIG. 4 ).
E. APP Protein Detection by Western Blotting
The human APP 751 protein was also identified by Western blotting in lysates from brains from these transgenic mice (FIG. 5 ). The quantity of protein APP 751 protein identified equaled that of the endogenous mouse APP 751 protein (see Figure legend for details).
E. Immunocytochemistry
Mice were deeply anaesthetized and then transcardially perfused with saline, followed by 4% paraformaldehyde in 0.1 M phosphate buffered saline (PBS). Brains were removed and post-fixed in 4% paraformaldehyde for 1 h, then placed in 30% sucrose in 0.1 M PBS at 4° C. until the brains sank and then frozen in isopentane at −35° C. and stored at −70° C. until sections were cut. Sections (20 mM) were cut in a cryostat (Reichert) and stored in anti-freeze at −20° C. Sections were removed from anti-freeze and washed through 5 changes of PBS and Triton X100 (0.3%). Background staining was blocked by incubating sections in normal goat serum (3% in PBS and Triton) for 90 minutes. The sections were then incubated overnight at 4° C. with a rabbit polyclonal antibody to synthetic β-amyloid (1-40) peptide (Boehringer Manheim). Again, the sections were washed thoroughly in PBS and Triton (3×5 minutes) and then immunostained using a standard avidin-biotin complex method (Vector Laboratories, Peterborough, UK). Stained sections were mounted on gelatin subbed air-dried and mounted in Depex. Commercially available monoclonal antibodies to the N-terminal end of the B-APP (clone 22C11, Boehringer Mannheim) intensely stained neurons in the cortex and hippocampus (CA3-CA1) of the APP 751 FAD mice that were 18 months old. This staining pattern was not homogeneous and appeared granular in neurons and neurites. This deposit-like accumulation of intraneuronal βAPP immunoreactivity was not seen in the control non-transgenic mice (FIG. 6 ).
EXAMPLE 4
Cell Culture
The transgenic animals of the invention may be used as a source of cells for cell culture. Brain tissues of transgenic mice are analyzed for the presence of human amyloid precursor protein by directly analyzing DNA or RNA or by assaying brain tissue for the protein expressed by the gene. Cells of brain tissues carrying the gene may be cultured using standard culture techniques that are well-known in the art.
EXAMPLE 5
Screening Assays
The transgenic animals and cells derived from the transgenic animals may be used to screen for compounds that modulate expression of human amyloid precursor protein. Modulation may occur at a variety of levels including but not limited to DNA or RNA or protein or combinations thereof.
One method of determining the ability of a compound to modulate the expression of human amyloid precursor protein in a transgenic non-human animal having cells containing a gene encoding a familial form of the human amyloid precursor protein APP 751 comprises: (a) treating the transgenic animal with the compound; (b) measuring the expression or aggregation of human amyloid precursor protein in the treated animal; and (c) comparing the measurement of step (b) with a control.
A method of determining the ability of a compound to modulate the expression of human amyloid precursor protein in cells derived from a transgenic animal comprises: (a) treating the cells with the compound; (b) measuring the expression or aggregation of human amyloid precursor protein in the treated cells; and (c) comparing the measurement of step (b) with a control.
EXAMPLE 6
Nucleotide Sequence of Relevant FAD APP 751 β-A4 Sequence
The 43 amino acid β-A4 domain is highlighted in bold. The V-I substitution is boxed (FIG. 7 ). | Transgenic non-human mammals which express in their brains a nucleic acid construct comprising a DNA sequence encoding a human amyloid precursor protein FAD variant where at amino acid position 717 valine is substituted by isoleucine. These transgenic non-human mammals can be assays systems for determining compounds which are effective in modulating production of human amyloid precursor protein in brain and in isolated neuronal cells. Specifically exemplified are transgenic mice whose genome comprises a DNA sequence encoding a human amyloid precursor protein FAD variant where at amino acid position 717 valine is substituted by isoleucine operably linked to a Thy-1 promoter. The mice are shown to produce the APP-FAD variant in their brains by mRNA and protein assays. | 0 |
TECHNICAL FIELD
[0001] This invention relates generally to spark plugs and other ignition devices used in internal combustion engines and, more particularly, to such ignition devices having noble metal firing tips. As used herein, the term “ignition device” means spark plugs, igniters, and other such devices that are used to initiate the combustion of a gas or fuel.
BACKGROUND OF THE INVENTION
[0002] A variety of iridium-based alloys have been proposed for use in spark plug electrodes to increase the erosion resistance of the firing surfaces of the electrodes.
[0003] Iridium has a relatively high melting point and is more resistant to spark erosion than many of the metals widely used today. The iridium is typically used in the form of a pad or rivet that is laser welded or otherwise metallurgically bonded to the center and ground electrodes on either side of the spark gap. There are, however, known disadvantages to the use of iridium, including difficulty in bonding of the iridium to the electrodes and oxidative volatilization of the iridium at higher temperatures. The present invention addresses the latter of these two problems.
[0004] A known approach for reducing the oxidative loss of iridium is to utilize it in the form of an alloy combined with rhodium. U.S. Pat. No. 6,094,000 and published UK patent application GB 2,302,367 to Osamura et al. discloses such an alloy in which rhodium can be included in an amount ranging from 1-60 wt %. Group 3A and 4A elements such as yttria or zirconium oxide can also be added to help reduce consumption resistance. Notwithstanding Osamura et al's teaching of use of rhodium in amounts as low as 1%, it has been found that minimization of oxidative loss of the iridium at higher temperatures requires much higher amounts of rhodium. This is borne out in the test data presented by Osamura et al. and their patent notes that the amount of rhodium is preferably at least 3%.
[0005] U.S. Pat. No. 5,793,793 to Matsutani et al. reports a similar finding, wherein the amount of rhodium is kept within the range of 3-50 wt % and, most preferably, is at least 18%. In U.S. Pat. No. 5,998,913, Matsutani identifies some disadvantages of the inclusion of high percentages of rhodium and, in an effort to reduce the amount of rhodium in the alloy, proposes the addition of rhenium or ruthenium. According to this patent, by adding rhenium and/or ruthenium in amounts up to 17 wt %, the amount of rhodium needed to maintain good resistance to oxidative consumption can be lowered to as little as 0.1 wt %.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to an ignition device having a pair of electrodes defining a spark gap therebetween, with at least one of the electrodes including a firing tip formed from an alloy of iridium, rhodium, tungsten, and zirconium. The combination of these constituent elements permits the known benefits of good erosion resistance and lowered sparking voltages to be obtained at much lower percentages of rhodium than has been found desirable in alloys containing only iridium and rhodium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] A preferred exemplary embodiment of the present invention will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements, and:
[0008] [0008]FIG. 1 is a fragmentary view and a partially cross-sectional view of a spark plug constructed in accordance with a preferred embodiment of the invention;
[0009] [0009]FIG. 2 is a side view of a rivet that can be used in place of the firing tip pads used on the spark plug of FIG. 1; and
[0010] [0010]FIG. 3 depicts a wire that can be used in place of the firing tip pads shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] Referring to FIG. 1, there is shown the working end of a spark plug 10 that includes a metal casing or housing 12 , an insulator 14 secured within the housing, a center electrode 16 , a ground electrode 18 , and a pair of firing tips 20 , 22 located opposite each other on the center and ground electrodes 16 , 18 , respectively. Housing 12 can be constructed in a conventional manner and can include standard threads 24 along with an annular lower end 26 to which the ground electrode 18 is welded or otherwise attached. Similarly, all other components of the spark plug 10 (including those not shown) can be constructed using known techniques and materials, excepting of course the ground and/or center electrodes 16 , 18 which are constructed with firing tip 20 and/or 22 , as will be described below.
[0012] As is known, the annular end 26 of housing 12 defines an opening 28 through which insulator 14 protrudes. Center electrode 16 is permanently mounted within insulator 14 by a glass seal or using any other suitable technique. It extends out of insulator 14 through an exposed, axial end 30 . Ground electrode 18 is in the form of a conventional ninety-degree elbow that is mechanically and electrically attached to housing 12 at one end 32 and that terminates opposite center electrode 16 at its other end 34 . This free end 34 comprises a firing end of the ground electrode 18 that, along with the corresponding firing end of center electrode 16 , defines a spark gap 36 therebetween.
[0013] The firing tips 20 , 22 are each located at the firing ends of their respective electrodes 16 , 18 so that they provide sparking surfaces for the emission and reception of electrons across the spark gap 36 . These firing ends are shown in cross-section for purposes of illustrating the firing tips which, in this embodiment, comprise pads welded into place on the firing ends. As shown, the firing tips 20 , 22 can be welded into partial recesses on each electrode. Optionally, one or both of the pads can be fully recessed on its associated electrode or can be welded onto an outer surface of the electrode without being recessed at all.
[0014] In accordance with the invention, each firing tip is formed from an alloy containing iridium, rhodium, tungsten, and zirconium. Preferably, the alloy is formed from a combination of iridium with 1-3 wt % rhodium, 0.1-0.5 wt % tungsten, and 0.05-0.1 wt % zirconium with no more than minor amounts of anything else. “Minor amounts,” means a combined maximum of 2000 ppm of unspecified base metal and PGM (platinum group metals) impurities. In a highly preferred embodiment, the alloy is formed from about 2.5 wt % rhodium, about 0.3 wt % tungsten, about 0.07 wt % zirconium, and the balance iridium with no more than trace amounts of anything else. The alloy can be formed by known processes such as by melting the desired amounts of iridium, rhodium, tungsten, and zirconium together. After melting, the alloy can be converted into a powdered form by an atomization process, as is known to those skilled in the art. The powdered alloy can then be isostatically pressed into solid form, with secondary shaping operations being used if necessary to achieve the desired final form. Techniques and procedures for accomplishing these steps are known to those skilled in the art.
[0015] Although the electrodes can be made directly from the alloy, preferably they are separately formed from a more conventional electrically-conductive material, with the alloy being formed into firing tips for subsequent attachment to the electrodes. Once both the firing tips and electrodes are formed, the firing tips are then permanently attached, both mechanically and electrically, to their associated electrodes by metallurgical bonding, such as laser welding, laser joining, or other suitable means. This results in the electrodes each having an integral firing tip that provides an exposed sparking surface for the electrode. Laser welding can be done according to any of a number of techniques well known to those skilled in the art. Laser joining involves forming a mechanical interlock of the electrode to the firing tip by using laser light to melt the electrode material so that it can flow into a recess or other surface feature of the firing tip, with the electrode thereafter being allowed to solidify and lock the firing tip in place. This laser joining technique is more fully described in European Patent Office publication no. EP 1 286 442 A1, the complete disclosure of which is hereby incorporated by reference.
[0016] As will be appreciated, the firing tips 20 , 22 need not be pads, but can take the form of a rivet 40 (shown in FIG. 2), a wire 42 (shown in FIG. 3), a ball (not shown), or any other suitable shape. Although a round-end rivet is shown in FIG. 2, a rivet having a conical or frusto-conical head could also be used. As indicated in FIG. 3, the firing tip can, but need not, include one or more surface features such as grooves 44 to permit it to be interlocked to the electrode using the laser joining technique discussed above. The construction and mounting of these various types of firing tips is known to those skilled in the art. Also, although the firing ends of both the center and ground electrodes are shown having a firing tip formed from the iridium/rhodium/tungsten/zirconium alloy, it will be appreciated that the alloy could be used on only one of the electrodes. The other electrode can be utilized without any firing tip or can include a firing tip formed from another precious metal or precious metal alloy. For example, in one embodiment, the center electrode firing tip 20 can be formed from the iridium/rhodium/tungsten/zirconium alloy and the ground electrode firing tip 20 can be formed from platinum or a platinum alloy.
[0017] The combination of iridium, rhodium, tungsten, and zirconium has been found to yield an alloy the exhibits good resistance to both spark and oxidative consumption, and the present invention permits these benefits to be maintained using relatively small amounts of rhodium.
[0018] It will thus be apparent that there has been provided in accordance with the present invention an ignition device and manufacturing method therefor which achieves the aims and advantages specified herein. It will, of course, be understood that the foregoing description is of preferred exemplary embodiments of the invention and that the invention is not limited to the specific embodiments shown. Various changes and modifications will become apparent to those skilled in the art. For example, although an ignition device in the form of a spark plug has been illustrated, it will be appreciated that the invention can be incorporated into an igniter of the type in which sparking occurs across the surface of a semiconducting material disposed between the center electrode and an annular ground electrode. All such changes and modifications are intended to be within the scope of the present invention. | An ignition device such as a spark plug having ground and center electrodes, at least one of which includes a firing tip formed from an alloy containing iridium, rhodium, tungsten, and zirconium. With the inclusion of tungsten and zirconium in the alloy, the percentage of rhodium can be kept relatively low without sacrificing the erosion resistance or reduced sparking voltage of the firing tip. In one embodiment, the firing tip contains 2.5% rhodium, 0.3% tungsten, 0.07% zirconium, and the balance iridium. | 7 |
This application claims priority to U.S. Provisional patent application No. 61/137,315. Filed Jul. 30, 2008 entitled WAVE CATCHER. Conformation #8917
BACKGROUND
This device (ELECTROWAVE) makes use or the speed, motion and weight of wave waters to produce a steady and uninterrupted supply of electricity. It uses a base which is well anchored to the ocean floor so that the devise is maintained in a secure position except for upward and downward motion. The devise is maintained at levels corresponding to the levels of the rising and falling tides by a devise which will be referred to as a “Surface Finder.” Maintaining a constant positioning of the ElectroWave enable it to better capitalize on the random motions of the surf. Also the devise is constructed primarily of plastics, fiberglass and other materials that can better withstand the caustic effects of ocean water.
SUMMARY OF THE INVENTION
As a wave moves up and forward it is ushered up a ramp and into a bucket-like structure. As the water moves up the ramp it presses the ramp downward and proceeds onward to fill the bucket-like structure (which will be referred to as the bucket). When the bucket has been filled with water a float that is located in the upper area of the bucket moves upward moving a lever which causes a snap which holds the bucket up to be released. The bucket then plunges downward. When the bucket arrives at the lower level one or more of the walls of the bucket and or the floor of the bucket is opened by releasing a snap which holds the walls and or the floor of the bucked in a closed position. The water then gushes out of the bucket. Weights which are located on the opposite end of the fulcrum then cause the bucket to rise once again to the uppermost position. The ramp is also located on a fulcrum with weights on the opposite end that return it to the uppermost position after it has been depressed. Also compressed air cylinders are located on the opposite ends of both fulcrums. They are attached to a lower base. The rods of the pistons are attached to an upper frame which moves them up and down in response to the upward and downward motions of the bucket and ramp. The air is then compressed by the compressed air cylinders and transferred to compressed air tanks. The air is then transferred to a compressed air motor which turns an electric generator producing an electric current
The ElectroWave device is maneuvered to match the changing surface levels by rolling upward and downward on two tracts which rise upward from a stationary platform. The platform is submerged but floats toward the surface via floats which are attached to it. It is located at a level that is beneath the level of the lowest ebb tide. The platform is attached to cables which are anchored to an ocean (or lake) floor. Also there is a tract which rises upward between one or both of the dual tracts described above. It has notches on it to which the devise attaches on order to prevent random upward movements that would be caused by the effect of the waves on the floats attached to the lower frame of the device. The tracts rise upward to the highest known level of the highest of the high tides including surges caused by wind.
As the device moves up and down the lower frame is kept on the same level as the surface of the waters by a mechanism called a SURFACE FINDER. This mechanism determines the surface level by using the familiar principle that water seeks it own level. The upward movements of the devise are determined by this surface finder which causes it to lock onto the notches as it moves upward in measured increments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side view of an electrowave device according to a preferred embodiment
FIG. 2 shows a repeat of FIG. 1 with a ramp in a downward position
FIG. 3 shows a 3 dimensional view of FIG. 2
FIG. 4 a shows a bucket in a locked position. FIG. 4 b shows a bucket in an unlocked position ready to descend.
FIG. 5 a shows top view of a float and locking mechanism. FIG. 5 b side views of FIG. 5 a , locked and unlocked.
FIG. 6 a shows the bucket in a lower position FIG. 6 b shows the bucket in the lowermost position with a snap released so that a door is opened and the water in the bucket is released. FIG. 6 c bucket resumes upper position.
FIG. 7 shows a joint ( 19 c ) that permits accommodation between the relative changes of position between the upper and lower frames.
FIG. 8 shows an anchored platform that floats upward toward the surface while remaining submerged. It supports the tracts on which the ElectroWave device rolls up and down and also enables the device to remain on the level of the surface of the tides.
FIG. 9 shows wheels that are mounted on the lower frame. They roll on tracts tracks described in FIG. 8 . Also there is a track with notches that are locked into to permit the device to remain at the level of the surface.
FIG. 10 shows a composite view of the base which supports the ElectroWave devise as described in FIGS. 8 & 9 .
FIG. 11 shows a view which demonstrates the relationship between the device and its supporting structures.
FIG. 12 a shows the SurfaceFinder mechanism ( 57 ) which enables the ElectroWave device to accommodate the changing surface levels which are due to tides, surges & etc.
FIG. 12 b shows the Surface Finder in the process of changing and locking into a different position to keep the ElectroWave device in accord with the changing surface levels. It also shows a pipe ( 50 ) which extends at least down to the still water level.
FIG. 13 shows the SurfaceFinder as it is positioned on the lower frame of the ElectroWave device.
FIG. 14 A side view of the Power Ramp in the upper position ready to be pressed onto a downward stroke.
FIG. 15 A side view of the Power Ramp in the lower position having completed the stroke.
FIG. 16 a A frontal view of the Surface finder with the latch and wheel locked into a notch when the float is in a downward position.
FIG. 16 b A frontal view of Surface Finder where the latch and wheel has been released from the notch so that the device has progressed upward to the notch above, permitting lower base on which it is mounted to rise and accommodate the new surface level.
DETAILED DESCRIPTION
Referring now to FIG. 1 which is a side view of a portion on the ElectroWave device. It demonstrates the following items: a float 34 which is attached to the lower frame 18 . An upper frame 21 , an axle joint 22 which supports the upper frame 21 and a ramp 11 with sides 9 , a bucket 10 is located on the front end of the upper frame 21 , on top of the bucket is a rod 12 . In front of the box is an emptying mechanism 13 - 17 it has wheels 14 , a flexible support 15 and or a spring 5 , and a joint 16 that enables the mechanism to lean forward and backward. There are also supports 6 , weights 20 that enable both the ramp and bucket to return to uppermost position after the water is no longer present Eg. the bucket has released its water and there is no water on the ramp. Compressed air cylinders 19 supply compressed air to a main tank 36 shown in FIG. 8 . Note that the ramp 11 is shown in its uppermost position.
Referring to FIG. 2 is the same as FIG. 1 except that the ramp 11 is in a downward position. Not that the rod of the compressed air cylinder 19 has engaged the plunger so as to compress the air in the cylinder.
Referring to FIG. 3 shows a composite 3-D view for clarification.
FIG. 4 a shows a release mechanism which consists of a float 24 attached to a rod 12 with a joint 16 . When the bucket is full the float rises and the wheel 23 is moved outward by a rod 12 . A support 13 with a joint 16 is pushed outward releasing a snap 7 which enables the bucket to fall downward from the position seen in FIG. 4 a . The float 24 rests on ledge 25 when the water in the bucket is at a lower level. The support 13 and joint 16 are attached to the lower frame 18 . The bucket 10 rests on the upper frame 21 .
FIG. 5 a shows a top view of a release mechanism described in FIGS. 4 a & 4 b . Eg. a float 24 a rod 12 , a wheel 23 , joints 28 and a support 13 . FIG. 5 b is a side view.
FIG. 6 a shows is a side view of the bucket in descent. A front wall 3 is kept closed by a snap 30 . FIG. 6 b shows the bucket in final descent. The snap 30 is forced into an open position by a protruding rod 31 attached to the base causing the door 3 to open releasing the water from the bucket. FIG. 6 c shows the bucket once again in the uppermost position. A protruding rod 32 forces the snap 30 into a closed position. A wheel 29 insures that the wall 3 is closed prior to snap 32 returning to a locked position.
FIG. 7 a Shows a side view of a joint 19 a that enables the compressed air cylinder 19 a swing back and forth in a front to back direction and vice versa. This enables the cylinder to maintain a more vertical position while the upper frame moves up and down moving the rod and plunger of the cylinder up and down. Other items shown are: a tube 35 to transfer air to a compressed air tank, a joint 22 which forms a fulcrum, a support 6 , ends of a lower frame 18 and an upper frame 21 and also a float 34 . FIG. 7 b shows a side view of the mechanism described in FIG. 7 a . FIG. 7 c demonstrates an air tube 35 , a compressed air tank 36 . a compressed air motor 37 and an electric generator 38 .
FIG. 8 Shows a composite view for orientation. A base platform 45 is located beneath the surface and waves 48 it has multiple floats on the underside 44 and is attached to cables on the underside which are attached to cement blocks or an or a different type of anchor located on the ocean floor 47 (or a lake floor). Located just above the waves is an ElectroWave device 44 . Also there are wheels 40 on which the devise rolls up and down on tracts 41 . Cables 42 can be attached from the support on top 43 as needed.
FIG. 9 Shows a side view of the base platform 45 as it relates to the wheels 20 which are mounted on the lower frame 18 of the ElectroWave device. The wheels roll up and down on the tract 41 as shown in FIG. 10. 44 are floats.
FIG. 10 Is a front view of the side view shown in FIG. 9 . A notched tract 55 which is located in between the double tract 41 which rises up from the base platform 45 . The Surface Finder mechanism (shown in FIG. 12 ) locks into the notches on this tract to enable the ElectroWave device to rise up in increments so that the lower frame 18 stays on the same level as the surface 3 of the water. The locking in also prevents random upward movements that would be caused by the effect of waves 48 on the floats 44 located on the underside of the lower frame. Also shown are wheels 40 and cables 42 .
FIG. 11 Shows a 3-D view for clarification of the relationship between the ElectroWave device 44 and the base 45 and tracts 55 & 41 . Also shown are floats 44 , waves 48 just above the surface, support 43 and cables 42
FIG. 12 a Shows a Surface Finder in a locked position, see 53 , while FIG. 12 b shows the device having progressed to an unlocked position and onward into a relocked position. Both are a front view of the Surface Finder device.
FIG. 12 a shows a notched tract 55 , a wheel which has locked into a notch in the tract 53 , joints 52 , a kettle 57 which contains a float 51 that rises when the water level rises. When 51 rises it engages the mechanism which disengages the wheel 53 which enables the ElectroWave device to move up a notch so the lower frame 21 is once again at the same level as the surface of the water. Also there is a support rod 54 , a float 34 and a wave 48 . Also there is a pipe 50 which extends downward from the kettle down to at least the still water level 60 . FIG. 12 c shows a top view of the kettle 57 and its float. Holes 56 in the top of the kettle (if a top is present).
FIG. 13 a shows a side view of the ElectroWave device with the Surface Finder mechanism in place on the lower frame of the device. Shone are a kettle 57 , a float 51 , a pipe (that goes downward to the still water level).
FIG. 13 b is a front view of the notched tract 55 .
FIG. 14 116 —A hinge with the lower leaf attached to the lower base and the upper leaf attached to the rear end of the ramp.
19 —A compressed air cylinder which compresses the air and transfers it to auxiliary compressed air tank when the rod is depressed. 113 —An auxiliary compressed air tank. 114 —A spring which returns the ramp tp an uppermost position after it has been depressed. 57 —A tubing through which the compressed air is transferred from the compressed air cylinder to the auxiliary compressed air tank. 118 —A latch with mounted wheel which is locked into a notch on the notched tract. 119 —A rod. 110 —A compressed air valve. 117 —An on off lever to turn compressed air valve on and off. 118 —A float in a lower position 121 —A receptacle that contains the input of water from the lower pipe which delivers water from the still water layer. 120 —A pipe leading from the still water layer up to the receptacle. 112 —A tubing. | A machine which capitalizes on the descent of water which has been elevated by making use of the random use of waves and or the velocity of the waters.
A device which determines the true surface level in spite of random motions of the waters such as waves, surges and etc. by establishing the theory that water seeks its own level.
A device which capitalizes on the velocity and weight of water, such as is present in waves and river waters, wherein the current has sufficient velocity to depress a ramp and produce useful energy. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
The present application is the national stage under 35 U.S.C. 371 of PCT/IL99/00080, filed Feb. 8, 1999.
FIELD OF THE INVENTION
The present invention relates to a method for performing cycled primer extension on a DNA template, and more particularly to methods including a primer extension step such as polymerase chain reaction (PCR) amplification and nucleotide sequencing comprising performing said PCR and sequencing reactions in the presence of an osmoprotectant selected from proline 2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine (hereinafter “THP(B)”), 2-methyl-4-carboxy-5-hydroxy-3,4,5,6-tetrahydropyrimidine (hereinafter “THP(A)”) and mixtures thereof, to improve yield and specificity of said reactions. The invention further relates to kits comprising proline, THP(B), THP(A), or mixtures thereof for use in PCR amplification and in cycle nucleotide sequencing.
BACKGROUND OF THE INVENTION
Primer extension on a DNA template is a step common to some of the most useful and powerful techniques in molecular biology. Polymerase chain reaction (PCR), one of these techniques, is a rapid, inexpensive and simple means of producing microgram amounts of DNA from minute quantities of source materials. Many variations on the basic procedure have now been described and applied to a range of disciplines.
In medicine, PCR's major impact is on the diagnosis and screening of genetic diseases and cancer, the rapid detection of mycobacteria and HIV, the detection of minimal residual disease in leukemia, and HLA typing. The PCR technique is also useful in forensic pathology and evolutionary biology, plays a central role in the human genome project and is routinely used in molecular biology processes (McPherson et al., 1992).
However, the practical use of PCR technology frequently faces difficulties and limitations. The necessity to convert originally duplex source DNA and then double-stranded DNA products into single stranded templates in every cycle of amplification is normally accomplished by thermal denaturation of DNA at 93-95° C. The DNA denaturation greatly depends on its nucleic base composition. A high GC content renders DNA amplification and sequencing very difficult, due to increased melting temperature and the stable secondary structure of the expanded motif. A common result of amplifying a region containing a repeat motif with a high GC content is the presence of additional amplification products, which do not correspond to the desired product (Varadaraj and Skinner, 1994). In addition, incomplete denaturation allows DNA strands to “snap back”, leading to a decrease in product yield. Denaturation steps that are conducted for long periods of time and/or at a high temperature lead to unnecessary loss of enzyme activity and dNTP decomposition.
Taq DNA polymerase, ordinarily used in PCR protocols, can withstand repeated exposure to the high temperature (94-95° C.) required for typical DNA strand separation, and thus simplifies the PCR procedure by eliminating the need to add an enzyme in each cycle. However, Taq polymerase appears to extend a mismatched primer/template in comparison to other polymerases with proofreading exonuclease activities, e.g. Klenow and T7 DNA polymerases, which are non-thermostable.
Another very effective technique employing primer extension is the cycle sequencing technique used for determining the order of nucleic acids in a target nucleotide sequence. This procedure involves repeated cycles of primer extension while the target nucleotide sequence is sequenced.
Similar considerations, as mentioned above for the PCR method, apply for the cycle sequencing procedure. In sequencing reactions as well, the complete denaturation of the template DNA is of crucial importance for a successful reaction. Thus, regions of DNA with repeat motifs, high GC content and rigid secondary structures are difficult to sequence. In addition, sequencing of a very long stretch of nucleotides, or of a target nucleotide sequence present in a minute amount is problematic. The ability to accomplish a complete denaturation of double stranded DNA and to perform sequencing reactions at reduced temperatures, either with Taq polymerase or with non-thermostable polymerase, is advantageous in terms of both yield and accuracy.
In an attempt to improve the yield and specificity of PCR and sequencing reactions, a number of buffer additives were employed. It was shown that certain cosolvents, such as DMSO (Pomp and Medrano, 1991; Filichkin and Gelvin, 1992), glycerol (Cheng et al., 1994; U.S. Pat. Nos. 5,432,065 and 5,545,539), formamide (Comey et al., 1991) and betaine (German Patents DE 4411594 C1 and DE 4411588 C1; Mytelka et al., 1996), facilitate standard PCR and/or cycle sequencing. It has been suggested that DMSO may affect the melting temperatures (Tm) of the template DNA and of the oligonucleotide primers and/or the degree of product strand separation at a particular “denaturation” as well as improving the thermal activity of Taq DNA polymerase (Gelfand and White, 1989). Glycerol may influence long amplifications by (i) doubling the thermal stability of Taq polymerase at 95-97° C., and (ii) effectively lowering DNA melting temperatures (by 2.5-3° C. for each 10% increase in glycerol concentration) (Cheng et al., 1994). Yet, the use of these buffer additives is limited, e.g. solutions containing glycerol in effective concentrations of 20-40% are viscous and difficult to handle (U.S. Pat. No. 5,432,065), DMSO in 10% concentration inhibits Taq DNA polymerase activity by 53% and T7 DNA polymerase is completely inactive in 40% formamide.
The compounds 2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine [THP(B)], also known as ectoine, and its hydroxy derivative, 2-methyl-4-carboxy-5-hydroxy-3,4,5,6-tetrahydropyrimidine [THP(A)] were previously identified in the laboratory of the inventors of the present invention as metabolites in several Streptomyces microorganisms (Inbar and Lapidot, 1988a; 1988b and 1991; Malin and Lapidot, 1996). Ectoine was also found in a variety of halophilic and halotolerant bacteria (Galinski et al., 1985). THP(B) and THP(A) are zwitterionic compounds (Inbar et al. 1993; FIG. 1) with many useful properties such as osmoprotection and thermoprotection of several organisms of the Streptomyces species and E. coli cells (Malin and Lapidot, 1996). THP(B) and THP(A) are not toxic neither to mammalian cells nor to animals (Lapidot et al., 1995). Israel patent No. 100810 and corresponding U.S. Pat. No. 5,789,414 and European Patent No. EP 0553884 of the present applicants disclose that THP(A) and THP(B) interact with and protect DNA in non-tumor tissues from damage by DNA-binding drugs and thus can be used for decreasing the toxic effects of DNA-binding drugs such as adriamycin and actinomycin D.
Proline is another osmoprotectant that accumulates in plants, bacteria, algae and marine invertebrates as a response to salinity stress. Proline was shown to destabilize DNA and to partially counteract the effect of sodium chloride and spermidine on the stability of the double helix, and to lower the melting temperature of DNA in a concentration-dependent manner (Rajendrakumar et al., 1997).
None of the above references describes or suggests the use of proline, THP(A) or THP(B) or mixtures thereof as additives to PCR reaction mixtures and in reactions for nucleotide sequencing.
SUMMARY OF THE INVENTION
It has now been found, according to the present invention, that THP(B) is effective in lowering the melting temperature of double-stranded DNA, and that proline, THP(B) and THP(A) are capable of increasing the thermal stability of DNA polymerases at elevated temperatures, indicating that they can be useful in procedures involving melting of double-stranded DNA and/or polymerase-mediated DNA synthesis, such as in primer extension, in PCR (polymerase chain reaction) amplification and in DNA sequencing.
Thus, in one aspect, the present invention provides a method for performing a cycled primer extension reaction comprising the steps of:
(i) contacting a template DNA comprising a target sequence of nucleotides with at least one primer oligonucleotide complementary to a nucleotide sequence at the 3′-end of said target sequence, under conditions allowing annealing of said primer to its complementary nucleotide sequence on said target sequence, in the presence of an osmoprotectant selected from proline, 2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine [THP(B)] and mixtures thereof, to lower the melting temperature of said template DNA and/or of said primer; and
(ii) carrying out a polymerase-mediated extension of said primer on said target sequence of nucleotides in the presence of an osmoprotectant selected from proline, THP(B), 2-methyl-4-carboxy-5-hydroxy-3,4,5,6-tetrahydropyrimidine [THP(A)] and mixtures thereof, to stabilize said polymerase,
thus obtaining a high yield specific extension of the primer on said target sequence of nucleotides of the template DNA.
Steps (i) and (ii) may be repeated a plurality of times, for example 10-90 times, preferably 15-35 times, and each step (i) is preceded by DNA thermal denaturation at a temperature suitable for separating both said template DNA into its strands and the polymerase-extended primer of step (ii) from its complementary target sequence of nucleotides, said temperature being a temperature in which the polymerase used in step (ii) is stable.
In one embodiment, the invention relates to a method for determining a nucleotide sequence of a target DNA, wherein in step (i) the target sequence of the template DNA is a sequence of nucleotides to be sequenced, and the polymerase-mediated extension of the primer in step (ii) is carried out in the presence of all four dNTPs: dATP, dCTP, dGTP and dTTP, and in the presence of a minute amount of either ddATP, ddCTP, ddGTP or ddTTP, prior to the determination of the nucleotide sequence of the target DNA. The dGTP can be substituted by 7-deaza-dGTP described in EP 0212536.
According to this embodiment, the method for determining a nucleotide sequence of a target DNA comprises the steps of:
(i) heating a template DNA comprising a target sequence of nucleotides to be sequenced at a temperature suitable for separating said template DNA into its strands in the presence of an osmoprotectant selected from proline, 2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine [THP(B)] and mixtures thereof;
(ii) contacting said denatured template DNA of step (i) with a primer oligonucleotide complementary to a nucleotide sequence at the 3′-end of said target sequence of nucleotides under conditions allowing annealing of said primer to its complementary nucleotide sequence on the target sequence, in the presence of an osmoprotectant selected from proline, 2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine [THP(B)] and mixtures thereof;
(iii) carrying out a polymerase-mediated extension of said primer of step (ii) in the presence of all four natural dNTPs: dATP, dCTP, dGTP (or 7-deaza-dGTP) and dTTP, of a minute amount of either ddATP, ddCTP, ddGTP or ddTTP and of an osmoprotectant selected from proline, THP(B), 2-methyl-4-carboxy-5-hydroxy-3,4,5,6-tetrahydropyrimidine [THP(A)] and mixtures thereof;
(iv) repeating steps (i)-(iii) a plurality of times; and
(v) determining the nucleotide sequence of the target DNA.
In another embodiment, the invention provides a method for amplifying a target sequence of nucleotides by polymerase chain reaction (PCR), wherein in step (i) the target sequence of the template DNA is a sequence of nucleotides to be amplified and the template DNA is contacted with two oligonucleotide primers complementary to the nucleotide sequences at the 3′-ends of said target sequence of nucleotides and its opposite strand; in step (ii) a polymerase-mediated extension of the annealed primers of step (i) is carried out; steps (i)-(ii) are repeated a plurality of times, the last step being step (ii), thus generating multiple copies of the target sequence of nucleotides.
According to this embodiment, the invention relates to a method for amplifying a target sequence of nucleotides by polymerase chain reaction (PCR) comprising the steps of:
(i) heating a template DNA comprising a target sequence of nucleotides to be amplified at a temperature suitable for separating said template DNA into its strands in the presence of an osmoprotectant selected from proline, 2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine [THP(B)] and mixtures thereof;
(ii) contacting the template DNA of step (i) with two oligonucleotide primers complementary to nucleotide sequences at the 3′-ends of said target sequence of nucleotides and its opposite strand; in the presence of an osmoprotectant selected from proline, 2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine [THP(B)] and mixtures thereof, under conditions allowing annealing of said oligonucleotide primers to their complementary sequences on said target sequence of nucleotides and its opposite strand;
(iii) carrying out a polymerase-mediated extension of the annealed primers of step (ii) in the presence of an osmoprotectant selected from proline, THP(B), 2-methyl-4-carboxy-5-hydroxy-3,4,5,6-tetrahydropyrimidine [THP(A)] and mixtures thereof; and
(iv) repeating steps (i)-(iii) a plurality of times, the last step being step (iii), thus generating multiple copies of the target sequence of nucleotides.
The methods of the invention are particularly useful for reactions involving GC-rich DNAs, thus diminishing or eliminating the difficulties found in amplification and sequencing of GC-rich DNA molecules. The methods are further useful for reactions involving in step (ii) or (iii) a thermostable DNA polymerase, such as Taq polymerase Klentaql polymerase and Pfu polymerase, or a non-thermostable DNA polymerase such as T7 DNA polymerase, T4 DNA polymerase, Klenow fragment of DNA polymerase I, reverse transcriptases, Bca polymerase, Bst polymerase and mutants of these polymerases.
In another aspect, the invention relates to the use of an osmoprotectant selected from proline, THP(B), THP(A) and mixture thereof as an additive in a reaction for determining a nucleotide sequence or as an additive to a PCR reaction mixture, and to kits comprising in separate containers: (a) the reagents necessary for DNA sequencing or the reagents necessary for a polymerase chain reaction, and (b) proline, THP(A) or THP(B).
In a further aspect, the invention relates to a method for lowering the melting temperature of double-stranded DNA (dsDNA) comprising adding to the incubation mixture of said dsDNA an effective amount of THP(B).
In a further aspect, the invention relates to a method for increasing stability of a DNA polymerase at elevated temperatures comprising adding to the incubation mixture of said polymerase an effective amount of an osmoprotectant selected from proline, THP(B), THP(A) and mixtures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the structural formulas of THP(A) (left) and THP(B) (right).
FIG. 2 depicts thermal transition of calf thymus DNA in the absence and presence of the indicated amounts of THP(B): 0.8M, 2M, 3M and 4M. DNA melting was performed as described in Materials and Methods, section (ii).
FIG. 3 depicts the variation of melting temperature (Tm) with THP(B) concentration for DNAs of varying base compositions. DNA melting was performed and Tms determined as described in Materials and Methods, section (ii). (filled triangles)—Calf thymus DNA; (filled circles)— Micrococcus lysodeikticus DNA; (filled squares)— Clostridium perfringens DNA; (open triangles)—poly(dA-dT).
FIGS. 4A-B depict thermal transitions of the oligonucleotides [d(ATGCAT)] 2 (SEQ ID NO: 1) and [d(GCTTAAGC)] 2 (SEQ ID NO: 2), respectively. The chemical shifts of the C4H5 proton of [d(ATGCAT)] 2 (SEQ ID NO: 1) and of the G1H8 proton of [d(GCTTAAGC)] 2 (SEQ ID NO: 2) were measured as described in Materials and Methods section (iii), as a function of increasing temperatures in the absence (open squares) or presence of 0.5M (open circles) and 1M (filled squares) THP(B).
FIG. 5 depicts the time course of thermal inactivation of Taq DNA polymerase at 97° C. in the absence (filled circles) and presence of either 1M THP(B) (filled squares), 1M THP(A) (open squares) or 1M glycerol (open diamonds). The thermal inactivation was determined at different periods of time from Taq polymerase remaining activity measured as described in Materials and Methods, section (vi).
FIG. 6 depicts ethidium bromide staining of PCR-amplified DNA products run on 1.7% agarose gel. PCR was performed according to the procedure described in Materials and Methods, section (viii), for amplification of a 349 b.p. fragment (66.5% GC content) from Halobacterium marismortui genomic DNA template at two different denaturation temperatures (Td), 95° C. (left) and 92° C. (right), in the absence and in the presence of 0.5M THP(B), as indicated. Two or three repetitions of each experiment are shown.
FIGS. 7A-7C depict ethidium bromide staining of PCR-amplified DNA products run on 1.7% agarose gel. PCR was performed according to the procedures described in Materials and Methods, section (viii), for amplification of a 349 bp. fragment (66.5% GC content) from Halobacterium marismortui genomic DNA template at three different denaturation temperatures (Td): 95° C. (FIG. 7 A), 90° C. (FIG. 7B) and 89° C. (FIG. 7 C), in the absence and presence of 1.0M THP(B). Two or three repetitions of each experiment are shown.
FIGS. 8A-8B depict thermal transition of calf thymus DNA (FIG. 8A) and other DNAs (FIG. 8B) in the presence and absence of proline. DNA melting was performed as described in Materials and Methods, section (ii). FIG. 8 A: —(filled diamonds)—no proline added; (open squares)—2.0M; (filled triangles)—3.5M; (filled squares)—5.0M; (open triangles)—5.5 M; (filled circles)—6.2M proline. FIG. 8B, in the presence of 6.2 M proline: (open triangles)— Micrococcus lysodeikticus DNA; (filled triangles)— Clostridium perfringens DNA; (filled squares)—calf thymus DNA; (filled circles)—poly(dA-dT).
FIG. 9A depicts a variation of Tm with proline concentration for DNAs of varying base compositions. DNA melting was performed as described in Materials and Methods, section (ii). (filled squares)—calf thymus DNA; (open triangles)— Micrococcus lysodeikticus DNA; (filled triangles)— Clostridium perfringens DNA; (filled circles)—poly(dA-dT). FIG. 9B depicts changes in dTm/dGC as a function of proline concentration.
FIG. 10 depicts Klenow DNA polymerase activity at 37° C. in the absence (dark bars) and in the presence of 5.0M proline (hatched bars). The activity of Klenow DNA polymerase was measured at 6.7, 10 and 15 mM MgCl 2 as described in Materials and Methods, section (iv).
FIG. 11 depicts the time course of thermal inactivation of Klenow DNA polymerase at 65° C. in the absence (filled circles) and presence of either 5M proline (open diamonds) or 5M glycerol (filled triangles). The remaining activity of Klenow DNA polymerase was measured at different periods of time as described in Materials and Methods, section (vii).
FIG. 12 depicts ethidium bromide staining of PCR-amplified DNA products run on 2.0% agarose gel. PCR was performed according to the procedure described in Materials and Methods, section (ix), for amplification of a 349 b.p, fragment (66.5% GC) from Halobacterium marismortui genomic DNA, using 10 and 15 units of Klenow fragment of DNA polymerase I.
FIG. 13 depicts ethidium bromide staining of PCR-amplified DNA products run on 1.7% agarose gel. PCR was performed according to the procedure described in Materials and Methods, section (x), for amplification of a 349 b.p. fragment (66.5% GC) from Halobacterium marismortui genomic DNA template catalyzed by Taq DNA polymerase at two different denaturation temperatures (Td), at 95° C. and 91° C., in the absence and in the presence of 1.0M proline. Three repetitions of each experiment are shown.
FIG. 14 depicts ethidium bromide staining of PCR-amplified DNA products run on 1.7% agarose gel. PCR was performed according to the procedure described in Materials and Methods, section (xi), for amplification of a 349 b.p. fragment (66.5% GC) from Halobacterium marismortui genomic DNA template catalyzed by KlenTaql DNA polymerase at two different denaturation temperatures (Td), at 77° C. and 75° C., in the presence of 4.0 M proline. Two repetitions of each experiment are shown.
DETAILED DESCRIPTION OF THE INVENTION
The term “primer extension” as used herein in the specification refers to a process of increasing the length of an oligonucleotide complementary to a nucleotide sequence comprised within a template DNA. The process consists of repeatedly adding to the oligonucleotide's 3′-end a single nucleotide which is dictated by the nucleotide present at the corresponding position in the complementary template DNA strand. The term “cycled primer extension” refers to a procedure which involves repeated cycles in which primer extension is alternated with periodic heating whereby separation of the extended primer from the template DNA strand occurs.
The term “melting temperature (Tm)” of double-stranded DNA (dsDNA) refers to a temperature at which 50% of a dsDNA sample is separated into its two complementary DNA strands.
The term “amplifying” refers to repeated copying of a specified sequence of nucleotides resulting in an increase in the amount of said specified sequence of nucleotides.
The term “sequencing” refers to a procedure for determining the order in which nucleotides occur in a target nucleotide sequence.
The term “target nucleotide sequence” refers to a nucleotide sequence which is intended to be duplicated, amplified or sequenced.
The term “template DNA” refers to DNA molecules or fragments thereof of any source or nucleotide composition, that comprise a target nucleotide sequence as defined above.
According to the present invention, THP(B) or proline or mixtures thereof can significantly lower the melting temperature of dsDNA, and proline, THP(B) or THP(A), alone or in combination, increase the stability of DNA polymerases incubated at elevated temperatures.
THP(B) and THP(A) for use in the invention can be isolated from natural sources such as, for example, from actinomycin D-producing microorganisms of the Streptomyces species, e.g., S. parvulus, S. chrismomalus , or S. antibioticus , and separated in purified form as described in IL Patent No. 100810 and corresponding U.S. Pat. No. 5,789,414 and EP 0553884. THP(B) alone can be isolated and purified from halophilic and halotolerant bacteria such as bacteria of the genus Ectothiorhodospira, e.g. E. halochloris, E. halophila and mutants thereof or from heterotrophic halophilic eubacteria of the family Halomonadaceae grown in high salinity conditions. THP(A) alone can be isolated and purified from soil microorganisms of the Streptomyces species, e.g. S. clavuligerus, S. griseus and mutants thereof, under low salt stress such as 0.25-0.5M NaCl. THP(B) can also be synthetically produced as described in Japanese Patent Application No. 63-259827.
L-Proline is a common amino acid that is commercially available or can be synthetically produced and obtained in highly purified form.
According to the invention, THP(B) was found to decrease the Tm of oligonucleotides as short as 6-8 mers and of dsDNAs being either genomic DNAs, cDNAs or recombinant DNA molecules, in a concentration dependent manner in concentrations ranging from 0.5 to 4M. The melting temperature of short oligonucleotides (6 or 8 mers) were reduced by 3 to 6° C. in the presence of 0.5M and 1.0 M THP(B).
The magnitude of the Tm decrease depends on the GC content of the particular oligonucleotide or dsDNA, being more pronounced with high GC content DNAs. For example, the Tm decrease of calf thymus DNA (42% GC) and of Micrococcus lysodeikticus DNA (72% GC content) in the presence of THP(B) was significantly higher than that of Clostridium perfringens DNA (26% GC content), while no change in the Tm of the synthetic oligonucleotide poly(dA-dT) could be observed in the presence of THP(B) at concentrations as high as 4M. At 4.0 M concentration of THP(B), DNAs with different GC content melt in a very narrow temperature range (40-43° C.), while in the absence of THP(B) the melting temperature ranges from 39 to 75° C. Isostabilization of the DNA molecule by THP(B) may be explained as a result of greater destabilization of GC-rich than AT-rich DNAs. THP(B) eliminates the DNAs base pair composition-dependence on DNA melting.
Proline, known to decrease DNA melting temperature (Rajendrakumar et al., 1997), was found according to the invention to only slightly decrease Klenow polymerase enzymatic activity and to be a better stabilizer of Klenow polymerase than glycerol, with a half-life of the enzyme of 21 min at 65° C. in 5 M L-proline. These findings have enabled a successful design of a PCR protocol for a rather GC-rich genomic DNA template. The amount of Klenow polymerase in the herein presented protocol (10-15 units) can be further reduced when 7-deaza-dGTP is used instead of dGTP, due to the expected decrease of denaturation temperature. The results herein reveal that proline concentration in the range of 3-5.5 M is sufficient to confer stability to Klenow polymerase.
Proline can be used as a sole additive in the protocol or in combination with glycerol or any other DNA-destabilizing agent which the polymerase tolerates, such as THP(B) or THP(A). Proline (up to 5.0 M) decreases the melting temperature (Tm) of various DNAs and leads to DNA partial “isostabilization” (a decrease of Tm difference between GC and AT pairs, manifested by an apparent linear decrease of dTm/GC factor (Melchior et al., 1973; Rees et al., 1993), while at higher concentrations, proline destabilizes GC and AT pairs evenly. A complete “isostabilation” of DNA, as in the case of betane (Rees et al., 1993) THP(B) (equal stability of AT and GC pairs, dTm/dGC=0), was not reached for proline. The Tm values of the tested natural DNAs (57-78° C.) decreased to a narrow range of 28-32° C. in the presence of 6.2 M prolione. The partial “isostabilization” of DNA by proline at high concentration may cause low specificity of PCR, when 20-25 b.p. primers are used.
Primers of 30-35 b.p. length, used in the herein presented PCR protocol, were found to be effective to remedy the decreased priming specificity at high concentrations of proline, and to achieve a good selectivity of amplification.
Besides standard PCR and DNA sequencing, the protocol with proline can be interesting for the following methods: a) use of Klenow polymerase in combination with contiguous hexamer primers and single-stranded DNA binding protein for a specific primer formation (Kieleczawa et al., 1992) utilizing a rather low amount of a source DNA; b) low denaturation temperature cycling might enable usage of less thermostable labels for DNA sequencing or PCR. This approach might be useful for other thermolabile polymerases in PCR and other DNA amplification methods. For example, T7 DNA polymerase and its modifications, able to amplify GC-rich DNA and regions with stable secondary structures, could provide solutions to the cases still remaining beyond today's practical PCR and DNA sequencing capabilities, such as amplification of long CGG triplet repeat sequences. Introduction of T4 polymerase to cycled PCR might be of interest for the cases requiring high fidelity, e.g. for amplification of sequences present at a very low frequency requiring many cycles of amplification to be detected.
According to the invention it was further found that proline, THP(B) and THP(A), alone or in combination, can stabilize both thermostable and non-thermostable DNA polymerases incubated at elevated temperatures, the stabilizing effect being more pronounced when the enzyme is incubated for prolonged periods of time and at a higher temperature than the temperature of their optimal activities. The thermostable Taq polymerase, after 30-35 min incubation under typical DNA denaturation temperature at 95° C., is only 50% active, and after 30 min incubation at 97° C., only 10% active in comparison to 40% in the presence of 1M THP(B) and even higher, 55%, in the presence of THP(A). A much more dramatic effect is obtained at longer incubation time (60 min), where the remaining activity is less than 5% without additives and is 55% in the presence of THP(A) (by 10-fold higher). The non-thermostable polymerases are much more sensitive to thermal inactivation, for example, the half life of Klenow DNA polymerase is around 30-50 seconds at 65° C., whereas in the presence of 5M proline it is 25 min, about 30-50 fold longer.
In preferred embodiments, cycled primer extension of any template DNA is conducted with the thermostable Taq polymerase at 60-80° C. in the presence of 0.5-3.5M THP(B), optionally with 0.5-3.0M THP(A), or 1-5M proline, or with a non-thermostable polymerase at 30-65° C. in the presence of 1-3 M THP(B), optionally with 0.5-3.0M THP(A), or 1-5M proline.
Lowering the Tm of dsDNA by proline and/or THP(B) and stabilization of DNA polymerases by proline, THP(B) and/or THP(A) are beneficial for cycled primer extension procedures that comprise steps of DNA melting and of polymerase-mediated DNA synthesis, such as DNA sequencing and PCR procedures, leading to high yields of dsDNA denaturation, namely separation of dsDNA into its two complementary strands at a lower temperature, and high performance of DNA polymerases.
The concentration of the osmoprotectant to be used in a particular cycled primer extension reaction depends on the specific template DNA, the primer(s), the DNA polymerase and the reaction conditions employed. Low concentrations of THP(B) or proline, typically around 0.5-1.5M, are preferred for lowering Tm of an average GC-content DNA, while higher concentrations, typically 1-3M, are preferred for high GC-content DNA, so to further lower the Tm and hence the denaturing temperature employed. To avoid major dissociation of primer/template DNA, when high concentrations of THP(B) (3-4M) and proline (4-5M) are used to lower DNA Tm to the range of 40-55° C. primers of at least 30 nucleotides are used. These modifications improve annealing and yield of the reaction.
The use of non-thermostable DNA polymerases such as T7 DNA polymerase or Klenow is of major importance in cases where accuracy of DNA amplification is crucial such as in detection of subtle changes in a DNA sequence and in processes of PCR typing and diagnosis of some genetic diseases and cancer caused by minor mutations, due to their high fidelity in DNA replication and proofreading ability.
Performing primer extension reactions at reduced temperatures also permits the use of thermosensitive fluorescent and other labile compounds for labeling newly synthesized DNA strands for use as probes in the detection of complementary target sequences of nucleotides by sensitive assays such as, chemiluminescence detection.
Reaction conditions used in PCR are variable depending on the nature of the template DNA and primers, and optimal pH and salt and magnesium ions concentrations are usually determined empirically for each particular reaction. A typical PCR procedure involves temperature cycling to provide adequate conditions for accomplishing three steps in each PCR cycle: (i) DNA denaturation; (ii) primer annealing; and (iii) primer extension.
A standard denaturation incubation step (i) at 94-95° C. for 0.5-2 min is usually sufficient for separating DNA strands of an average GC content from the original and newly synthesized DNA. The primer annealing step (ii) is performed usually around 5° C. lower than the melting temperature of the primer-template DNA duplex. However, if non-specific PCR products are obtained in addition to the expected product, the annealing temperature should be increased. The extension (step iii) of the annealed primer at its 3′ end to synthesize a new DNA strand, complementary to the template strand, is usually carried out by the thermostable enzyme Taq polymerase at 70-75° C., which is the optimal temperature range for the enzyme activity (˜2-4 Kb/min.).
The complete denaturation of the DNA template, especially at the first amplification cycles, is of most importance in PCR procedures, otherwise its use as a template for the following reaction steps decreases and results in poor yield of the PCR product. This is especially relevant when an amplified DNA duplex has a very high GC content, rendering it difficult in strand separation, or when a target nucleotide sequence is present in a minute amount in the initial reaction mixture. Thus, PCR buffers containing solutes leading to significant lower Tms of the DNA templates are most important in PCR procedures. The addition of proline, THP(B), THP(A) or mixtures thereof to PCR procedures is beneficial in three levels: (i) increased yield of the amplified DNA products; (ii) increased sensitivity; and (iii) increased specificity of the reaction. The effect of proline and THP(B) in decreasing Tms of oligonucleotide primers and of template DNAs, and the effect of proline, THP(B) and THP(A) in stabilizing DNA polymerases, result in more efficient use of the template DNAs, primers and enzymes of the reaction, leading to high yield of PCR-amplified DNA product. Moreover, the increased sensitivity of PCR assays in the presence of the additive enables detection of target DNA sequences that are not detectable in its absence. This is especially significant in cases where very rare or long target sequences are to be amplified. In addition, the additives also improve the quality of PCR amplification by reducing significantly or eliminating nonspecific products. The improved accuracy of PCR in the presence of proline, THP(B) and/or THP(A) enables performing PCR protocols with increased number of cycles and longer cycle times, without impairing the quality of the reaction products.
In another embodiment, the invention provides a method for cycle DNA sequencing comprising contacting a template DNA with a primer homologous to a specific sequence on a target DNA in the presence of a DNA polymerase and an effective amount of proline, THP(B) and/or THP(A) under conditions allowing DNA sequencing.
A commonly used cycle DNA sequencing protocol known as Sanger or dideoxy sequencing method, typically includes isolating double stranded template DNA, separating it into its component single strands, adding a sequencing primer homologous to a sequence of nucleotides on the target DNA and performing a cycled primer extension of said primer on the target DNA. The cycled primer extension is performed in four paralleled reactions, each including a small amount of a dideoxynucleotide triphosphate, either ddATP, ddCTP, ddGTP or ddTTP, along with a molar excess of the four deoxynucleotide triphosphates (dNTPs) normally required for DNA synthesis, i.e. dATP, dCTP, dGTP or dTTP. The growth of the extended DNA chain is stopped once a ddNTP molecule is incorporated into it, thus generating series of extension products of various lengths. When these extension products of the four extension reactions are separated side by side, for example on a polyacrylamide gel, a pattern is obtained. By using a labeled primer or labeled ddNTP, typically radioactive or fluorescent, this pattern can be monitored, for example, by autoradiography, fluorescence detectors etc, and the DNA sequence can be determined.
Cycle DNA sequencing also involves cycle primer extension, thus the sequencing outcome is influenced by similar criteria as mentioned above for PCR. The degree of template DNA and primer denaturation, as well as the polymerase performance, are of crucial importance for the sensitivity and accuracy of a sequencing reaction. The exact reaction conditions for performing a cycle DNA sequencing method and the effective concentrations of the added osmoprotectant vary depending on the template DNA, primers, target DNA to be sequenced and the DNA polymerase used in a particular reaction.
Cycle sequencing performed in accordance with the invention in the presence of proline, THP(B) and/or THP(A), is a beneficial and sensitive tool. The osmoprotectant additive permits obtaining a sequence of a longer stretch of nucleotides in a single reaction, as well as to sequence minute amounts of DNA present, for example, in limited samples of blood or tissue used in forensic pathology and in evolutionary biology. In addition, some GC-rich DNAs or other DNAs with complex or rigid secondary structure that are very difficult to sequence using conventional reaction mixtures, can thus be successfully sequenced. Since in the presence of the additives the specificity of primer annealing is increased and non-specific extended products are mostly eliminated, detection of rare mutations becomes feasible. This is especially important in diagnosis of diseases characterized by a small mutation in a gene nucleotide sequence or in identification of high CGG repeats that are indicative of many human disorders, such as Huntington's disease (Han et al., 1994).
The kits for performing DNA amplification by PCR or for DNA cycle sequencing of the invention include, respectively, the reagents necessary for PCR or DNA sequencing (e.g. appropriate buffers, dNTPs, either Taq or a non-thermostable polymerase, etc.) and, in separate containers, THP(B) optionally with THP(A) or proline.
EXAMPLES
Materials and Methods
(i) Materials
For Examples 1-4, THP(A) and THP(B) were prepared according to Malin and Lapidot (1996) and their water solutions were passed through a chelex column to remove divalent cations before use. Betaine (Sigma) was dissolved in water and passed through a chelex column before use. Taq DNA polymerase (recombinant) and Klenow fragment of DNA polymerase I (10 units/μl) were purchased from MBI Fermentas, calf thymus DNA (used in the DNA melting examples) and activated calf thymus DNA (used in the polymerase activity assays), Micrococcus lysodeikticus DNA, Colstridium perfringens DNA and poly(dA-dT) from Sigma. The oligonucleotides [d(ATGCAT)] 2 (SEQ ID NO: 1)and [d(GCTTAAGC)] 2 (SEQ ID NO: 2) and the following 28-mer primers 1 and 2 were prepared by solid-phase phosphouramidate synthesis:
1. 5′>CGG GAT CCA TGG AAT ACG TAT ACG CTG C<3′(SEQ ID NO: 3)
2. 5′>CGG AAT TCT TAG CCG AAG AGT TCG CCG A<3′(SEQ ID NO: 4)
For Examples 5-9, L-proline 99+% and 99.5+% were purchased from Sigma and from Fluka, respectively, and glycerol was from BDH. Activated calf thymus DNA and calf thymus DNA was from Sigma. Taq DNA polymerase (recombinant) and Klenow fragment of DNA polymerase I (10 units/μl) were purchased from MBI Fermentas. Klentaql DNA polymerase from AB Peptides and Pfu DNA polymerase (cloned) from Stratagene. Halobacterium marismortui genomic DNA template was a generous gift of Dr. Shulamith Weinstein (Kimmelman Laboratory of Biocrystallization, Weizmann Institute of Science).
Two pairs of primers were used in Examples 7-9: two 28-mer primers 3 and 4 with 22 of complementary nucleotides each and with end restriction site: primer 3 containing BamHI restriction site and primer 4 containing EcoRI restriction site, and two 30-mer primers 5 and 6 with all 30 complementary nucleotides:
3. 5′>CGG GAT CCA TGG AAT ACG TAT ACG CTG C<3′(SEQ ID NO: 3)
4. 5′>CGG AAT TCT TAG CCG AAG AGT TCG CCG A<3′(SEQ ID NO: 4)
5. 5′>ATG GAA TAC GTA TAC GCT GCA CTC ATC CTG<3′(SEQ ID NO: 5)
6. 5′>TTA GCC GAA GAG TTC GCC GAG GCC CTC ACC<3′(SEQ ID NO: 6)
All oligonucleotides and primers for Examples 1-9 were prepared by the Chemical Service Unit of the Weizmann Institute of Science, Rehovot, Israel, and their solution concentrations were determined by UV absorbance at 260 nm.
(ii) DNA Melting Experiments
DNA melting studies were conducted in a buffer (1 ml) containing 5.0 mM K 2 HPO 4 and 0.1 mM Na 2 EDTA at pH 7.5. The buffer and THP(B) or proline solutions were filtered through 0.22 μm Millipore membrane filter, prior to addition of the DNA, and then degassed with helium at room temperature. DNA samples were adjusted to O.D 360 =0.2 and incubated overnight at 37° C. before use, as previously described (Rees et al., 1993). DNAs in the above buffer with and without THP(B) or proline were measured in 1-cm path Teflon-stoppered quartz cell and incubated at the initial assay temperature for 5 min. The increase in absorbance at 260 nm was monitored in Hewlett Packard 9450A diode array spectrophotometer attached to a temperature programmer and controller. Both the sample and the reference cells were heated together at a rate of 0.5° C./min and the net absorbance was recorded after every 0.5° C. increase. The Tms were determined graphically from the midpoints of the absorbance versus temperature profile.
(iii) NMR measurements of chemical shift changes
1 H NMR measurements were carried out on a Bruker AMX 400 NMR MHZ spectrometer at 400.13 MHZ (equipped with an Aspect 300 control). For the 1 H NMR measurements, 1.0 mM DNA oligonucleotides were dissolved in 0.5 ml phosphate buffer solution (pH 7.2) in D 2 O (20 mM, for [d(ATGCAT)] 2 (SEQ ID NO:1) and 40 mM for [d(GCTTAAGC)] 2 (SEQ ID NO:2) containing 50 mM NaCl and 0.1 mM EDTA. The solutions were lyophilized and then redissolved in 0.5 ml D 2 O (99.96%), heated to 65° C. and gradually cooled to 5° C., and then degassed with argon at room temperature.
(iv) Klenow DNA polymerase activity assay
The assay was performed at 37° C. in 15 μl reaction mixture containing 67 mM Tris-HCl (pH 7.4), 1.0 mM β-mercaptoethanol, 5.2 nM, [α- 32 P]dATP, 6.4 μM dATP and 320 μM of each dCTP, dGTP, dTTP, 0.6 mM activated calf thymus DNA, and 6.7 mM MgCl 2 for THP or 6.7, 10.0 and 15 mM MgCl 2 for proline, Klenow fragment (0.1 units) was added to the microtubes with reaction mixtures pre-heated at 37° C., and following 7.5 minutes incubation at 37° C. (a time-point within the region of linear kinetics determined in a separate experiment, not shown), the reaction microtubes were placed on ice, and the reaction was stopped by addition of 12 μl of 50 mM EDTA and then applied on strips of chromatographic paper (Whatman No. 3). Strips were washed three times by cold TCA 10%, dried and the radioactivity was counted.
(v) Determination of remaining activities of Tag polymerase after incubation with THP(A) or THP(B) at elevated temperatures
Taq polymerase (0.5 units) was added to 50 μl buffer containing: 10 mM tris-HCl (pH 8.8 at 25° C.), 2.5 mg Halobacterium morismortui genomic DNA template, 2 μm of each of the dNTPs: dATP, dCTP, dGTP and dTTP, 0.12 nM of each of the two 28-mer oligonucleotide primers 1 and 2 described in section (i) above, 50 mM KCl, 0.08% Nonidet P40 and 1.0 mM MgCl 2 . THP(B), THP(A) or glycerol were added from 3M stock solutions (pH 8.8 at 25° C.). The reaction mixtures were overlaid with paraffin oil and incubated at 95° C. or 97° C. Aliquots (7.5 μl) were taken for polymerase activity assay at different periods of time.
(iv) Determination of remaining activity of Klenow DNA polymerase after incubation at 65° C. with proline
Klenow DNA polymerase (0.5 unit) was incubated at 65° C. in 50 μl buffer containing: 67 mM tris-HCl (pH 7.4 at 25° C.), 2.5 ng Halobacterium marismortui genomic DNA template, 4 μM of each of the dNTPs dATP, dCTP, dGTP and dTTP, 0.12 nM each of the two 28-mer oligonucleotide primers 3 and 4 described in section (i) above, 6.7 mM MgCl 2 and either without or in the presence of 5.0M glycerol or proline. Tris-HCl buffer, template DNA, dNTP, primers and MgCl 2 were added to PCR microtubes, evaporated to dryness by speed-vacuum and respective volumes of water, proline (from a 5.5M stock solution) or glycerol (from a 5.5M stock solution) were added. The microtubes were vortexed and Klenow enzyme was added to the samples. Aliquots (5 μl) were taken for polymerase activity assay at different periods of time as indicated in FIG. 11 . The Klenow DNA polymerase activity assay was performed as described in section (iv) above at 6.7 mM concentration of MgCl 2 . To each aliquot (5 μl) 20 μl of stock solution containing all other components of the assay were added, making a total reaction volume of 25 μl and a 5-fold dilution of the aliquots. Thus, proline and glycerol concentration in the polymerase assay were 1.0M, shown to be stimulative for Klenow polymerase activity in a separate experiment (data not shown).
(vii) Polymerase Chain Reaction (PCR) procedure with THP(B)
PCR was performed in 25 μl reaction mixture containing 3 ng temperature DNA, 0.12 nM of each 28-mer oligonucleotide primer 1 and 2 described in section (i) above 0.5 units Taq DNA polymerase. 200 μM of each dNTP, in PCR buffer containing: 10 mM Tris-HCl (pH 8.8 at 25° C.), 50 mM KCl, 0.08% Nonidet P40. MgCl 2 concentrations of 1.0 mM and 1.75 mM were used in the absence and presence of THP(B), respectively, added from a 3M stock solution (pH 8.8 at 25° C.). Reaction mixtures were overlaid with paraffin oil and preheated for 3 min at their respective denaturing temperatures, except for mixtures of reactions performed at Td 95° C., that were preheated for 3 min. at 94° C., and then subjected to 35 thermal cycles as follows: (i) 30 sec incubation at 89-95° C., as indicated i each experiment (denaturation step); (ii) 90 sec. incubation at 55° C. (annealing step); and (iii) 60 sec incubation at 72° C. (primer extension).
(viii) PCR in the presence of proline, using Klenow DN4 polymerase.
PCR was performed in a 25 μl reaction mixture containing 100 ng Halobacterium marismortui genomic DNA template, 0.12 nM of each 30-mer oligonucleotide primers 5 and 6 described in section (i) above 10 or 15 units of Klenow DNA polymerase. 0.9 mM of each dNTP, in PCR buffer containing 10 mM Tris-HCl (pH 7.4 at 25° C.) and 15 mM Mg(OAc) 2 . Tris-HCl buffer, temperature DNA, dNTP, primers and Mg(OAc) 2 were added to PCR microtubes, evaporated to dryness by speed-vacuum and dissolved in 22 μl of a proline-glycerol solution (5.5M of L-proline in 12.5% w/v solution of glycerol in water). Reaction mixtures were preheated for 3 min at 75° C., and then subjected to 35 thermal cycles as follows: (i) 20 sec incubation at 70° C. (denaturation step); (ii) 4 min incubation at 37° C. (primer annealing and primer extension steps). Klenow DNA polymerase (10 or 15 units) diluted up to 3 μl volume, containing 50% w/v glycerol, was added during the first primer annealing step at 37° C.
(ix) PCR in the presence of proline, using Tq DNA polymerase.
PCR was performed in 25 μl reaction mixture containing 3 ng of Halobacterium marismortui genomic DNA temperature, 0.12 nM of each 28-mer olignocleotide primers 3 and 4 described in section (i) above, 0.5 units of Taq DNA polymerase, 200 μM of each dNTP, in PCR buffer containing : 10 mM Tris-HCl (pH 8.8 at 25° C.), 50 mM KCl, 0.08% Nonidet P40. MgCl2 concentrations of 1.0 mM and 1.8 mM were used in the absence and in th presence of 1.0M L-proline, respectively. L-proline was added from 5.5 M stock solution adjusted to pH 8.8 at 25° C. Reaction mixtures were preheated for 3 min at their respective denaturation temperatures, except for reactions performed at Td 95° C., that were preheated for 3 min at 94° C., and then subjected to 35 thermal cycles as follows: (I) 30 sec incubation at 91-95° C., as indicated in each experiment (denaturation step); (ii) 90 sec incubation at 55° C. (primer annealing step); and (iii) 60 sec incubation at 7° C. (primer extension).
(x) PCR in the presence of proline, using a mixture of Klentaql and Pfu for Vent) DNA polymerases.
PCR was performed in 25 μl reaction mixture containing 250 ng of Halobacterium marismortui genomic DNA template, 0.12 nM of each 30-mer oligonucleotide primers 5 and 6 described in section (i) above, 0.3 μl of Klentaql and Pfu (or Vent) enzymes mixture, prepared as described (Barnes, 1994), 200 μM of each dNTP, in PCR buffer containing : 10 mM Tris-HCl (pH 8.3 at 25° C.) and 50 mM KCl Mg(OAc) 3 concentrations of 1.0 mM and 14.5 mM were used in the absence and in the presence of 4.0M L-proline, respectively, L-proline was added from 5.5 M stock solution adjusted to pH 8.3 at 25° C. Reaction mixtures were preheated for 1 min at their respective denaturation temperatures, except for reactions performed at Td 95° C., that were preheated for 1 min at 94° C., and then subjected to 35 thermal cycles as follows: (I) 30 sec incubation at 72-95° C., as indicated in each experiment (denaturation step); (ii) 90 sec incubation at 37-55° C., as indicated in each experiment (primer annealing step); and (iii) 7 min incubation at 63-69° C., as indicated in each experiment (primer extension).
Example 1
DNA melting in the presence of THP(B)
The effect o different concentrations of THP(B) on the melting profile of calf thymus DNA (42% GC) was studied. Melting experiments were conducted as described in Materials and Methods, section (ii), in the absence or presence of 0.8M, 2M, 3M and 4M THP(B).
As shown in FIG. 2, the addition of THP(B) significantly lowered the DNA melting temperature and sharpened its transition profile. The DNA melting temperature in aqueous solution, 62° C., was lowered to 41° C. in the presence of 3 or 4M THP(B).
The effect of THP(B) on DNA melting temperatures was examined on other DNAs with different base compositions, such as Micrococcus lysodeikticus and Clostridium perfringens DNAs (72% and 26% GC, respectively) and on the synthetic poly(dA-dT). As shown in FIG. 3, the melting temperatures (Tm) of the different DNAs decreased with the increase of THP(B) concentration in the incubation mixture. This effect is more pronounced for GC-rich DNAs. While the oligonucleotide poly(dA-dT) did not exhibit any change in the melting temperature in the presence of 1-4M (THP(B), 3-4M THP(B) eliminated the base-pair composition dependence of DNA thermal melting. As shown in FIG. 3, in the presence of 4M THP(B), all DNAs with a wide range of GC content melt in a very narrow temperature range (40-43° C.), while in the absence of THP(B), the melting temperatures ranged from 39 to 75° C. This isostabilization effect by THP(B) may be explained as a result of greater destabilization of GC-rich than AT-rich DNAs.
Example 2
Short oligonucleotides melting in the presence of THP(B)
The thermal transitions of the short oligonucleotides [d(ATGCAT)] 2 (SEQ ID NO:1) (FIG. 4A) and [d(GCTTAAGC)] 2 (SEQ ID NO:2) (FIG. 4B) were studied in the absence (open squares) and presence of 0.5M (open circles) and 1.0M (filled squares) THP(B). NMR chemical shift changes of the C4H5 proton of [d(ATGCAT)] 2 (SEQ ID NO:1) and of the G1H8 proton of [d(GCTTAAGC)], (SEQ ID NO:2) were measured as a function of increasing temperatures as described in Materials and Methods section (iii). The results of these experiments are depicted in FIGS. 4A-B and summarized in Table 1.
TABLE 1
Tm° C.
DNA-THP (B)
DNA-betaine
Oligonucleotide
DNA
0.5 M
1.0 M
1.0 M
[d(ATGCAT)] 2 (SEQ ID NO:1)
31.5
29.5
28.0
29.2
[d(GCTTAAGC)] 2 (SEQ ID
48.0
45.0
42.0
—
NO:2)
As shown in Table 1, the melting temperatures of [d(ATGCAT)] 2 (SEQ ID NO:1) and of [d(GCTTAAGC)] 2 (SEQ ID NO:2) decreased by 2° C. and by 3° C., respectively, in the presence of 0.5M THP(B), and by 3.5° C. and 6° C., respectively, in the presence of 1.0M THP(B). Data were compared to the melting temperature of [d(GCTTAAGC)] 2 (SEQ ID NO:2) in the presence of betaine. The decrease in Tm by betaine was only −2° C. at 1.0M concentration, about two-fold higher concentration of betaine is needed for exerting the same Tm decline caused by THP(B).
Example 3
THP(B) and THP(A) effects on Taq DNA polymerase stability at elevated temperatures
The effect of THP(B) and THP(A) on the remaining activity of Taq DNA polymerase incubated at elevated temperatures for different periods of time were studied.
After 90 min incubation at 95° C., Taq DNA polymerase was only 30% active. The enzyme was remarkably stabilized upon addition of either THP(B) or THP(A). After incubation at 95° C. in the presence of 0.5M THP(B) or 0.5M THP(A), the half life of Taq polymerase was 70 min and 60-90 min, respectively, in comparison to the half life of 30-40 min observed in the absence of additive (not shown). Comparable protective effects were obtained when Taq DNA polymerase was incubated at 95° C. in the presence of a combination of THP(A) and THP(B) (results not shown). Thus, THP(B) and/or THP(A) present in the reaction mixture enable doubling PCR cycles without increased loss of enzyme activity.
in FIG. 5 are shown results of similar experiments measuring the thermal inactivation of Taq polymerase at 97° C. in the absence (filled circles) or presence of 1M THP(B) (filled squares), 1M THP(A) (open squares) in comparison to 1M glycerol (open diamonds). The thermal inactivation of the enzyme at the elevated temperature 97° C. was, as expected, more rapid than the inactivation at 95° C., almost a complete loss (>95%) of enzyme activity was observed following 60 min incubation at 97° C., with no additives. However, also the protective effects by THP(B) and THP(A) were more dramatic: the remaining Taq polymerase activities, following 30 min incubation at 97° C. were 40% and 50% in the presence of 1M THP(B) or THP(A), respectively, in comparison to 10% remaining activity in the absence of additives. As a result of 60 min incubation at 97° C., the remaining Taq polymerase activity in the absence of additive was 5%, whereas in the presence of 1M THP(B) or THP(A) the remaining activities were 20% and 45%, respectively. The results shown in FIG. 5 indicate that THP(A) is more effective than THP(B) or glycerol in stabilizing Taq DNA polymerase.
Example 4
PCR in the presence of THP(B)
The combined effect of THP(B) on DNA melting temperatures and on Taq DNA polymerase activity and stability at elevated temperatures was followed under PCR conditions.
PCR reaction was performed by Taq DNA polymerase as described in Materials and Methods, section (viii), using as a temperature whole genomic DNA of Halobacterium marismortui (66.5% GC) and the 28-mer primers 1 and 2 described in section (i).
In FIG. 6 are depicted the amplified DNA sequences produced by PCR performed at 95° C. and 92° C., in the absence and presence of 0.5M THP(B), respectively, showing that yield and specificity of the DNA amplification was improved by the presence of THP(B). At 92° C. amplified sequences were produced only in the presence of THP(B), but not in its absence.
The effect of 1.0M THP(B) in the PCR buffer mixture in presented in FIGS. 7A-C. A “control” assay was performed at Td 95° C. in the absence and presence of 1.0M THP(B) with two concentrations of Taq DNA polymerase, 0.5 and 0.75 units in 25 μl PCR reaction mixture. The presence of 1.0M THP(B) improved PCR specific amplification at Td 95° C. (FIG. 7 A). However, the most significant results were obtained when denaturation temperatures of the DNA were reduced from 95° C. to 90° C. (FIG. 7B) in the presence of 1.0M THP(B) (either with 0.5 or 0.75 units of Taq DNA polymerase in 25 μl reaction mixture). Under these conditions, specific amplified sequence was generated only in the presence of THP(B), while no trace of amplified DNA could be detected in the absence of this additive.
When Td was further lowered to 89° C. in the presence of 0.5 units Taq DNA polymerase in 25 μl reaction mixture, amplified DNA sequence was markedly lower, even in the presence of 1.0M THP(B) but no trace of amplified DNA was detected in the absence of THP(B) (FIG. 7 C).
Example 5
DNA melting in the presence of proline.
The effect of different concentrations of proline on the melting profile of calf thymus DNA (42% GC) was studied. Melting experiments were conducted as described in Materials and Methods, section (ii), in the absence or presence of 2M, 3.5M 5M and 6.2M proline.
As shown in FIG. 8A, the addition of proline significantly lowered the DNA melting temperature and sharpened its transition profile. The DNA melting temperature in aqueous solution, 62° C., was lowered in 27° C. in the presence of 6.2M proline.
The effect of proline on DNA melting temperatures was examined on different DNAs with different base compositions, such as Micrococcus lysodeikticus and Clostridium perfringens DNAs (72% and 26% GC, respectively), calf thymus DNA (42% GC) and on the synthetic poly(dA-dT). As shown in FIG. 8B, the melting temperatures (Tm) of the different DNAs decreased in the presence of 6.2M proline concentration in the incubation mixture. The range of melting DNA with GC content of 72% is about 5° C. higher than that of GC content of 42% and 26%, while poly(dA-dT) melts about 15° C. lower.
The effect of increasing concentration of proline as depicted in FIG. 9A on the four DNAs reveals that the effect was pronounced for GC-rich DNAs. While the oligonucleotide poly(dA-dT) did not exhibit any change in the melting temperature in the presence of 1-5M proline, a small effect occurred in the range of 6-6.2M proline. Proline at 6.2M almost eliminated the base-pair composition dependence of DNA thermal melting. As shown in FIG. 9A, in the presence of 6.2M proline all DNAs with a wide range of GC content melt in a very narrow temperature range (25-32° C.), while in the absence of proline the melting temperatures ranged from 38 to 78° C.
FIG. 9B depicts changes in dTm/dGC as a function of proline concentration. A linear correlation is presented for proline concentration of up to 5M.
Example 6
Klenow polymerase activity in the presence of proline.
To study the effect of 5.0M L-proline on the Klenow DNA polymerase activity, experiments were conducted as described in Materials and Methods, section (iv), in the presence of different concentrations of MgCl 2 : 6.7 mM, 10.0 mM and 15.0 mM MgCl 2 .
As shown in FIG. 10, L-proline only slightly decreased Klenow DNA polymerase activity. The activity of the enzyme remained high enough, particularly at 10.0 (hatched bar, middle) and 15.0 mM MgCl 2 (hatched bar, right).
Example 7
The effect of 5.0M proline on the stability of Klenow DNA polymerase at 65° C.
The remaining activity of Klenow DNA polymerase incubated at 65° C. in the presence of 5.0M proline, 5.0M glycerol or without any additives, was measured as described in Materials and Methods, section (vi). As shown in FIG. 11, Klenow DNA polymerase at 65° C. has a half-life of less than one minute with no additives (filled circles), 3 minutes in the presence of 5.0M glycerol (filled triangles) and 21 minutes in the presence of 5.0M proline (open diamonds).
Example 8
PCR in the presence of proline, using Klenow DNA polymerase.
The combined effects of proline in Klenow DNA polymerase stability at elevated temperatures and on DNA denaturation temperature step, permitted a successful design of cycled PCR conditions for this enzyme. PCR was performed by Klenow DNA polymerase as described in Materials and Methods, section (viii).
PCR amplification of a 349 b.p. fragment (66.5% GC) of Halobacterium marismortui genomic DNA (from position 2546 to 2843) was performed in a 25 μl reaction mixture containing 100 ng of the DNA template, 0.12 nM of each 30-mer oligonucleotide primers 5 and 6 described in section (i) above, 0.9 mM of each dNTP, 10 mM Tris-HCl (pH 7.4 at 25° C.) and 15 mM of magnesium acetate. Tris-HCl buffer, template DNA, dNTP, primers and magnesium acetate were added to PCR microtubes from stock solutions, evaporated to dryness by speed-vacuum and dissolved in 22 μl of a proline-glycerol solution, containing 5.5M of L-proline in a 12.5% v/w solution of glycerol in water. Klenow polymerase (10 units/μl, storage buffer contains 50% w/v glycerol) and, in order to keep constant glycerol concentration in the PCR mixtures, aliquots of glycerol solution in water (50% w/v glycerol) were added during the first primer annealing step.
As shown in FIG. 12, in lanes 1, and 2, 1.0 μl of Klenow polymerase (10 units) and 2.0 μl of the glycerol solution were added, and in lanes 3, and 4, 1.5 μl of Klenow polymerase (15 units) and 1.5 μl of the glycerol were added. The final concentration of L-proline in all PCR mixtures was 4.85M and of glycerol was 17% w/v. All PCR reactions were run on a MJ Research PTC-100 machine equipped with a normal block (ramping rate is 1° C. per section). Reaction mixtures were preheated for 3 min at 75° C., and then subjected to 35 thermal cycles as follows: a) 20 sec incubation at 70° C.; b) 4 min incubation at 37° C. Reaction products were run on a 2% agarose gel and strained by ethidium bromide.
The results shown in FIG. 12 reveal that proline concentration i the range of 3-5.5M is sufficient to confer stability to Klenow DNA polymerase and to conduct a successful PCR protocol.
Example 9
PCR in the presence of proline, using Taq DNA polymerase.
FIG. 13 shows PCR, using Taq DNA polymerase, performed in the absence and in the presence of 1.0M proline, as described in Materials and Methods, section (ix). Addition of 1.0M proline to the reaction mixture did not impair PCR performance at denaturation temperature 95° C. and enabled successful PCR at decreased denaturation temperature, namely 91° C.
Example 10
PCR in the presence of proline, using mixture of Klentaql and Pfu DNA polymerase.
PCR was performed in the presence of 4.0M proline, using a mixture of Klentaql and Pfu DNA polymerases, as described in Materials and Methods, section (x). Reaction mixtures were preheated for 1 min at their respective denaturation temperatures (77° C. and 75° C.), and then subjected to 35 thermal cycles as follows: (i) 30 sec incubation at 77° C. or 75° C. (denaturation step), (ii) 90 sec incubation at 44° C. (primer annealing step); and (iii) 7 min incubation at 65° C. (primer extension).
As shown in FIG. 14, there is a clear correlation between the concentration of proline in the mixture and the minimal denaturation temperature. Thus, true for above mentioned conditions, 4.0M concentration of proline was enough for successful PCR at the 77° C. denaturation temperature, but not at 75° C.
References
1. Barnes, W. M. (1994) PCR amplification of up to 35-kb DNA with high fidelity and high yield from λ bacteriophage temperatures, Proc. Natl. Acad. Sci. 91, 2216-2220.
2. Cheng, S., C. Fockler, W. M. Barnes and R. Higuchi (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 5695-5699.
3. Comey, C. T. J. M. Jung and B. Budowle (1991) BioTechniques 10, 60-61.
4. Filichkin, S. A. and S. B. Gelvin (1992) BioTechniques 12, 828-830.
5. Gainski, E. A. H. P. Pfeifer and H. G. Truper (1985) Eur. J. Biochem. 149, 135-139.
6. Gelfand, D. H. and White (1989) in PCR Technology: Principles and Applications for DNA Amplification (Erlich, H. A. ed). pp. 17-22, Stockton Press, New York.
7. Han, J. et al. (1994) Nucleic Acids Research 22, 1735-1740.
8. Inbar, L. and A. Lapidot (1988a) J. Bacteriol, 170, 4055-4064.
9. Inbar, L. and A. Lapidot (1988b) J. Biol. Chem 263, 16014-16022.
10. Inbar, L., and A. Lapidot (1991) J. Bacteriol, 173, 7790-7801.
11. Inbar. L., F. Frolow and A. Lapidot (1993) Eur. J. of Biochem. 214, 897-906.
12. Kieleczawa, J., Dunn, J. J., and Studier, F. W. (1992) Science 258, 1787-1791.
13. Lapidot, A., Ben-Asher, E. and Eisenstein, M. (1995) FEBS Letters 367, 33-38.
14. Malin, G. M. and A. Lapidot (1996) J. Bacteriol. 178, 385-395.
15. Melchior, W. B., Von Hippel, P. H. Jr., and Von Hippel, P. H. (1973) Proc. Natl. Acad. Sci. U.S.A. 70: 298-302
16. Mcpherson, M. J., P. Quirke and G. R. Taylor (1992) in PCR, A practical approach. (Mcpherson, M. J., Quirke P. and Taylor, G. R., Editors), IRL Press, Oxford University Press.
17. Mytelka, D. S. and M. J. Chamberlain (1996) Nucl. Acids Res. 24, 2774-2781.
18. Pomp, D. and J. F. Medrano (1991) BioTechniques 10, 58-59.
19. Rajendrakumar, S. V., Suryanarayana, T., and Reddy, A. R. (1997) FEBS Letters 410, 201-205.
20. Rees, W. A. T. D. Yager, J. Korte and P. H. Von Hippel (1993) Biochemistry 32, 137-144.
21. Varadaraj, K. and D. M. Skinner (1994) Gene 140, 1-5.
6
1
12
DNA
Artificial Sequence
Synthetic
1
atgcatatgc at 12
2
16
DNA
Artificial Sequence
synthetic
2
gcttaagcgc ttaagc 16
3
28
DNA
Artificial Sequence
synthetic
3
cgggatccat ggaatacgta tacgctgc 28
4
28
DNA
Artificial Sequence
synthetic
4
cggaattctt agccgaagag ttcgccga 28
5
30
DNA
Artificial Sequence
synthetic
5
atggaatacg tatacgctgc actcatcctg 30
6
30
DNA
Artificial Sequence
synthetic
6
ttagccgaag agttcgccga ggccctcagg 30 | The osmoprotectants proline, 2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine (“THP(B)”, and 2-methyl-4-carboxy-5-hydroxy-3,4,5,6,-tetrahydropyrimidine (“THP(A)”) are capable of increasing the thermal stability of DNA polymerases at elevated temperatures. THP(B) is further effective in lowering the melting temperature of double-stranded DNA. Proline, THP(A) and THP(B) are thus useful in procedures involving melting of double-stranded DNA and/or polymerase-mediated DNA synthesis, such as in primer extension, in PCR (polymerase chain reaction) amplification and in DNA sequencing. | 2 |
TECHNICAL FIELD
The present invention relates to a cell culture vessel and a culture device. In particular, the present invention relates to a method for improving incubation efficiency.
BACKGROUND ART
Regenerative medicine has gotten a lot of attention as an innovative medical treatment, which enables basic remedy for damaged and/or defective cells, tissues, and organs. The regenerating tissue used for regenerative medicine, which is produced through the steps of collecting cells from the body of a patient or the other person; separating and purifying the collected cells in vitro, and growing and organizing the cells into tissue, is transplanted into the body of the patient. Tissue engineering, making advances yearly, has enabled the methods for forming one kind of cells into a sheet and for arranging several kinds of cells sterically to assemble an organ by artificial means to be developed.
To amplify therapeutic cells, in particular adherent cells in large quantities, an incubator large in area is useful. It is because adherent cells are amplified while expanding in the planar direction. On the other hand, it has a problem that as the area of an incubator becomes larger, its culture surface increasingly deforms; thereby, cells aggregate in a lower area, leading to deteriorated usage efficiency. As an effective technique for manipulating cells, electrophoresis has gotten attention. The systematic study and theoretical analysis of electrophoresis were set out by Pohl in 1970s (see Nonpatent Literature 1). Micro biological substances, such as bacteria and cells, have been already employed as a principal target to be manipulated since the initial study; accordingly, biotechnology is one of key applications of electrophoresis.
A dielectrophoretic force F DEP exerted on dielectric particles is given by the following equation 1 (see Nonpatent Literature 1). In the following paragraph, how to calculate is explained taking an example of dielectric particles being cells.
[Mathematical formula 1]
F DEP =2πα 3 ∈ 0 ∈ m Re[K]∇E 2 (Formula 1)
Where a is the radius of a cell approximated to a spherical shape, ∈ 0 : electric permittivity in vacuum, ∈ m : specific electric permittivity in medium, E: electric field intensity, and ∇ is an operator representing a gradient. In this case, ∇E 2 , which is the gradient for the square of an electric field intensity (E 2 ), indicates how degree E 2 inclines at that point, namely, how suddenly the electric field spatially changes. K is called a Claudius-Mossotti number and is represented by an equation 2. Herein, assuming that ∈ b * and ∈ m * be complex dielectric constants for cells and a medium, respectively, and Re [K] be the real part of the Claudius-Mossotti number, Re [K]>0 represents positive electrophoresis and the cells migrate in the same direction as that of the electric field gradient, namely toward an electric field concentration part. Re [K]<0 represents negative electrophoresis and cells migrate in the direction apart from the electric field concentration part, namely toward a weak electric field part.
[
Mathematical
formula
2
]
K
=
ɛ
b
*
-
ɛ
m
*
ɛ
b
*
+
2
ɛ
m
*
(
Formula
2
)
Formula 3 generally represents complex dielectric constant ∈ r * .
[
Mathematical
formula
3
]
ɛ
r
*
=
ɛ
r
-
j
σ
ω
ɛ
0
(
Formula
3
)
Where, ∈ r is the specific electric permittivity for a cell or medium, σ is the electric conductivity of a cell or medium, and ω is the angular frequency of an applied electric field. As known from Formulae 1, 2, and 3, a dielectrophoretic force depends on the radius of a cell, the real part of a Claudius-Mossotti number, and an electric field intensity. Moreover, it is known that the real part of the Claudius-Mossotti number varies depending on the complex electric permittivity and electric field frequency of a cell and medium.
The DEPIM method, combining dielectrophoresis and impedance measurement, has been proposed as a method for measuring microbial counts using dielectrophoresis. The DEPIM method is characterized in that these parameters are appropriately selected and a positive dielectrophoretic force exerted on microorganisms is sufficiently increased to collect the microorganisms into an electrode gap, making electrical measurement to determine a microbial count in the sample solution (see Nonpatent Literature 2).
In addition, a culture device, which eliminates unnecessary cells from a cell suspension using negative dielectrophoresis to culture necessary cells at high concentrations, is disclosed (see Patent Literature 1 and Patent Literature 3).
Moreover, a method and apparatus, for collecting cells efficiently in a target area without losing the activity of functional cells using positive dielectrophoresis, is disclosed (see Patent Literature 2).
CITATION LIST
Patent Literature
Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2009-291097
Patent Literature 2: Japanese Unexamined Patent Application Publication No. 2008-54511
Patent Literature 3: US Patent Application Publication No. 2008/0057505, Specification
Nonpatent Literature
Nonpatent Literature 1: H. Pohl: Dielectrophoresis, Cambridge University Press, Cambridge (1978)
Nonpatent Literature 2: J. Suchiro, R. Yatsunami, R. Hamada, M. Hara, J. Phys. D: Appl. Phys. 32 (1999) 2814-2820
SUMMARY OF INVENTION
Technical Problem
However, it is difficult to manipulate cells and microorganisms directly in an ion-rich culture solution (namely, high electric conductivity) using dielectrophoresis described in BACKGROUND. For this reason, generally, the target cells are moved in an ion-poor buffer solution, manipulated, and then returned back in the original culture solution. As a result, a cell manipulation process is complicated, causing a problem of increased stress on the cells due to a change in culture environment. In addition, this method has another problem that generally, an enzyme is used to detach the cells grown during surface culture from the surface of culture medium, increasing load on the cells.
An object of the present invention is to simplify the cell manipulation process to reduce the stress on the cells, as well as the load on the grown cells exerted when detached from the surface of the culture medium in order to solve these problems. This makes possible to improve culture efficiency of a cell culture vessel and determine cell distribution and growth via electric signals.
Solution to Problem
To address the aforementioned problems, the key characteristics of the cell culture vessel of the present invention are as described below.
A cell culture vessel for supporting and culturing cells is composed of a space enclosed by a housing for supporting a medium and a cell attachment part disposed on the bottom surface of the space for attaching and supporting the cells therein. The cell attachment part has a cell immobilizing mechanism for guiding the cells to the cell attachment part from the cell space and immobilizing them therein, and a cell detachment mechanism for detaching the cells attached in the cell attachment part. The cell immobilizing mechanism includes a step of applying voltage in an electrode to generate an inhomogeneous electric field in the space, and the cell detachment mechanism includes a step of applying voltage in an electrode disposed in the cell attachment part to induce electrolysis in the space.
A cell culture device of the present invention is mainly characterized as described below. The cell culture device equipped with the cell culture vessel for supporting and culturing the cells therein is composed of a feeding/discharging part for feeding/discharging the medium into/from the cell culture vessel, and a power source for applying voltage to an electrode disposed in the cell culture vessel. A cell culture vessel is composed of a space enclosed by a housing for supporting a medium and a cell attachment part disposed on the bottom surface of the space for attaching and supporting the cells therein. The cell attachment part has a cell immobilizing mechanism for guiding the cells into the cell attachment part from the cell space and immobilizing them therein, and a cell detachment mechanism for detaching the cells attached in the cell attachment part. The cell immobilizing mechanism includes a step of applying voltage in an electrode to generate an inhomogeneous electric field in the space, and the cell detachment mechanism includes a step of applying voltage in an electrode disposed in the cell attachment part to induce electrolysis in the space.
It has been known that in the ion-rich environment with the electric conductivity of the medium equal to or less than 1000 mS/m, dielectrophoresis becomes negative always at the frequency equal to or less than 10 9 Hz. Taking advantage of cell migration in the direction apart from the electric field concentration, namely toward the weak electric field by negative electrophoresis, the present invention enables the cells to be immobilized in a desired location.
The cells may be detached from the surface of the culture medium by applying a direct current (DC) field; thereby, the need for the use of any enzyme (e.g., trypsin) in cell detachment, as with traditional apparatuses, is eliminated.
Advantageous Effects of Invention
The present invention enables the culture efficiency of the cell culture vessel to be improved and the cell distribution and growth to be determined via electric signals.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram showing one configuration of a cell culture vessel of the present invention.
FIG. 2 is a diagram showing one configuration of an electrode disposed in a cell immobilizing mechanism of the present invention.
FIG. 3 is a diagram illustrating the relationship between the frequency of an alternate current (AC) field and the real part Re [K] of a Claudius-Mossotti number.
FIG. 4 is a diagram illustrating the use of circular electrodes as cell immobilizing electrodes.
FIG. 5 is a diagram illustrating the use of comb-shaped electrodes as the cell immobilizing electrodes.
FIG. 6 is a diagram illustrating the use of castle-wall electrodes as the cell immobilizing electrodes.
FIG. 7 is a diagram illustrating how to immobilize the cells by the cell immobilizing electrodes of the present invention.
FIG. 8 is a diagram illustrating how to grow the cells in the cell culture vessel of the present invention.
FIG. 9 is a view showing the state of the cell culture vessel before the cells are detached by the electrodes disposed in the cell detachment mechanism of the present invention.
FIG. 10 is a view the state of the cell culture vessel after the cells are detached by the electrodes disposed in the cell detachment mechanism of the present invention.
FIG. 11 is a view illustrating an equivalent circuit for the cells in the gap formed between the electrodes.
FIG. 12 is a diagram showing another configuration of the electrodes disposed in the cell detachment mechanism of the present invention.
FIG. 13 is a diagram showing the other configuration of the electrodes disposed in the cell detachment mechanism of the present invention.
FIG. 14 is a view showing the state of the cell culture vessel after the cells have been seeded according to an example 1.
FIG. 15 is a view showing the state of the cell culture vessel after the cells have been grown according to the example 1.
FIG. 16 is a view exemplifying the influence of an applied frequency on impedance between the electrodes of the present invention.
FIG. 17 is a view exemplifying a time-course change in impedance between the electrodes of the present invention.
FIG. 18 is a view showing a cell concentration apparatus according to an example 3 of the present invention.
FIG. 19 is a view illustrating the relationship between the frequency of an AC electric field and the real part RE [K] of a Claudius-Mossotti number.
FIG. 20 is a view illustrating the principle of concentration of the cell by dielectrophoresis of the present invention.
FIG. 21A is a view illustrating a flow A of cell concentration by the cell concentration apparatus according to the example 3 of the present invention.
FIG. 21B is a view illustrating a flow B of cell concentration by the cell concentration apparatus according to the example 3 of the present invention.
FIG. 21C is a view illustrating a flow C of cell concentration by the cell concentration apparatus according to the example 3 of the present invention.
FIG. 21D is a view illustrating a flow D of cell concentration by the cell concentration apparatus according to the example 3 of the present invention.
FIG. 22 is a view showing a cell concentration apparatus according to a fourth embodiment of the present invention.
FIG. 23A is a view showing a flow A of concentration measurement at the cell concentration apparatus according to an example 4 of the present invention.
FIG. 23B is a view showing a flow B of concentration measurement at the cell concentration apparatus according to the example 4 of the present invention.
FIG. 23C is a view showing a flow C of concentration measurement at the cell concentration apparatus according to the example 4 of the present invention.
FIG. 23D is a view showing a flow D of concentration measurement at the cell concentration apparatus according to the example 4 of the present invention.
FIG. 24 is a view illustrating an equivalent circuit for a cell disposed between the electrodes.
FIG. 25 is a view showing a cell concentration system of an example 5 of the present invention.
FIG. 26 is a flow sheet illustrating the step of controlling the cell concentration system according to the example 5 of the present invention.
FIG. 27A is a view showing a cell concentration apparatus having a multilayer electrode structure according to an example 6 of the present invention.
FIG. 27B is a view showing a cell concentration apparatus having a multilayer electrode structure according to the example 6 of the present invention.
FIG. 27C is a view showing a cell concentration apparatus having a multilayer electrode structure according to the example 6 of the present invention.
DESCRIPTION OF EMBODIMENTS
Hereinafter, by reference to the accompanying drawings, the embodiments of the present invention will be explained. It should be noted that the same signs are assigned to the same components in the drawings and the explanation of these components are omitted.
Hereinafter, by reference to the accompanying drawings, the embodiments will be explained.
First Embodiment
One example of the cell culture vessel of the present invention will be explained by reference to FIG. 1 .
In FIG. 1, 1 is the ceiling substrate of the cell culture vessel, 3 is an upper electrodes including an electrode couple, which is disposed on the ceiling substrate 1 . 2 is a bottom substrate of the cell culture vessel, 4 are lower electrodes for immobilizing the cells, which is disposed on the bottom substrate. 5 is an internal space of a cell culture vessel, and 5 A is a medium containing cells 5 B. 6 is a medium inlet, at which a valve 6 A is disposed, 7 is a medium outlet, at which a valve 7 A is disposed, 8 is a mixed gas inlet, at which a valve 8 A is disposed and 9 is a mixed gas outlet, at which a valve 9 A is disposed. 10 is an AC power source and 11 is an impedance measuring apparatus for measuring impedance between the electrode couple. 12 is a DC power source, 13 A is a switch for conducting electricity from the upper electrode 3 to the lower electrode 4 through the DC power source 12 , and 13 B is a switch for conducting electricity from the AC power source 10 to the lower electrode 4 .
FIG. 2 is a plan view showing one configuration of the electrodes disposed in the cell immobilizing mechanism. 4 is a thin film electrode disposed on the bottom surface and 14 is an on/off switch for supplying or interrupting current to/from the power source 10 . 15 A, 15 B, and 15 C are driving circuits for controlling the switch 14 .
The aforementioned the ceiling substrate 1 and the bottom substrate 2 may be formed using any of insulating materials, as their base material, such as glass, silicone, quartz plastics, polymers. Preferably, the ceiling substrate 1 and the bottom substrate 2 are formed using, as their material, any of materials with light transmittance to the degree that the cells are enabled to be observed under an optical microscope, and more preferably, for the surface of the bottom substrate 2 , a material is used, which may be modified through cleaning and preprocessing processes before the cells are attached thereon.
Generally, an ion-rich, highly-conducting medium (1000 mS/m) is used for cell culture, in particular for animal cell culture. FIG. 3 is a diagram showing the relationship between the frequency of a DC electric field and the real part Re [K] of a Claudius-Mossotti number. As known from the figure, when the electric conductivity of the medium is equal to or higher than 1000 mS/m, dielectrophoresis is negative dielectrophoresis (negative DEP) in all cases at the frequency equal to or lower than 10 9 Hz. Specifically, the cells migrate in the direction away from the center of the electric field, namely toward the weak electric field. It should be noted that preferably, the applied frequency is equal to or lower than 10 7 Hz because the dielectrophoretic force is proportional to the amplitude of Re [K].
As shown in FIG. 4 , at the center of the four electrodes disposed in the cell immobilizing mechanism according to the first embodiment, a weak electric field is formed. This enables the cells in the highly-conducting medium to migrate into this weak electric field and be immobilized there. Moreover, individually controlling these four electrodes allows for control of cell distribution. It goes without saying that circular electrodes have been described in regard to the first embodiment, but rectangular or polygonal electrodes may be used.
The present invention is not limited to the electrodes according to the aforementioned first embodiment but may be the electrodes formed into the shape capable of generating the weak electric field shown in FIG. 5 and FIG. 6 ; it is because this type of electrodes enable the cells in the highly-conducting medium to migrate into the weak electric field and be immobilized there through a negative dielectrophoretic force.
In the case of the cells culture on the surface of the medium, it is desired that to grow the cells, a layer for facilitating cell attachment capacity, for example a polymeric membrane, is coated between the bottom surface of the incubator between the electrodes, as well as the surfaces of the electrodes.
Hereinafter, by reference to FIGS. 7, 8, 9, and 10 , the flow of a process involving the steps of seeding cells homogenously, culturing the cells for growth, and detaching the cells is explained.
As shown in FIG. 7 , cells 5 B seeded in five mediums 5 A in the cell culture vessel migrate into many weak electric fields of the lower electrode 4 and are immobilized there separately. Accordingly, it is possible to suppress the influence of the deformed bottom surface of the cell culture vessel, external vibrations during cell seeding, and medium vibration, achieving homogenous cell seeding over the whole surface of the cell culture vessel. Homogenous cell seeding improves the use efficiency of the cell culture vessel, increasing cell culture efficiency. Moreover, measuring changes in impedance in the gap between the lower electrodes 4 makes it possible to estimate the distribution of cells immobilized in the weak electric fields. Using this advantage, the cell distribution may be easily estimated using electric signals rather than an optical microscope.
During the step of culturing the cells (for example, animal cells) for growth, the cells are attached to the culture surface at 37° C. for growth. During the step of exchanging a mixed gas for culture (composed of air, 5% Co 2 , and 100% water), as shown in FIG. 8 , the gas is introduced into the cell culture vessel from a mixed-gas inlet 8 thereof, and waste gas produced by culture is discharged from a mixed-gas outlet 9 . During the step of exchanging the medium, a new medium is introduced from a medium inlet 6 and waste medium is discharged from a medium outlet 7 . Since the culture surface is disposed directly above the lower electrodes 4 , measuring changes in impedance in the gap between the lower electrodes 4 allows for estimation of cell growth progress. This enables real-time measurement of the cell growth progress through the electric signals with no need for observation of the progress under an optical microscope.
To detach the grown cells from the culture surface, as shown in FIG. 9 , first, the cell culture vessel is filled with the medium 5 A. Then, the switch 13 B is turned OFF and the switch 13 A is turned ON. This operation applies the DC electric field is applied between the lower electrode 4 and the upper electrode from the DC power source 12 . Applying an appropriate DC voltage enables the cells to be detached from the culture surface, as shown in FIG. 10 , by the effect of electrolysis occurring on the surface of the lower electrode. In this case, the cells may be detached with no need for using the enzyme (for example, trypsin) as with conventional techniques. Accordingly, the cost of an enzyme may be saved.
The cells contained in the medium precipitate, when left as it is, spontaneously down toward the bottom of the cell culture vessel under its own weight. However, it takes long time, about several hours, for the cells to reach the bottom of the incubator and initiate their growth, especially for light cells; thereby they are likely to die before they initiate their growth. To solve this problem, it is required that an appropriate voltage is applied to facilitate cell immobilization. However, even though the voltage is applied, the precipitated cells are eccentrically deposited; thereby it is not expected that the cells grow homogeneously over a wide range.
According to the first embodiment of the present invention, it is expected that the death of the cells may be avoided.
Moreover, according to the first embodiment of the present invention, the cell culture vessel of the present invention enables the cells to be incubated more efficiently, the distribution and growth progress of the cells to be estimated, and the cells to be detached from the culture surface through electrophoresis. In other words, the cell culture vessel according to the first embodiment of the present invention has advantages of improving cell culture efficiency and reducing the running cost of the apparatus using the cell culture vessel.
Second Embodiment
With regard to the second embodiment of the present invention, explained is a method for estimating the distribution and growth progress of the cells by measuring the impedance between the lower electrodes of the present invention.
Hereinafter, assuming that the impedance between the lower electrodes be Z, capacitance be C, reactance be x, resistance be r, and resistor be R, the aforementioned method is explained using formulas 4 to 8 by reference to FIG. 11 .
[
Mathematical
formula
4
]
Z
=
R
-
j
ω
R
2
C
1
+
ω
2
R
2
C
2
(
Formula
4
)
[
Mathematical
formula
5
]
r
=
R
1
+
ω
2
R
2
C
2
(
Formula
5
)
[
Mathematical
formula
6
]
x
=
-
j
ω
R
2
C
1
+
ω
2
R
2
C
2
(
Formula
6
)
[
Mathematical
formula
7
]
R
=
r
+
x
2
r
(
Formula
7
)
[
Mathematical
formula
8
]
C
=
x
ω
(
r
2
+
x
2
)
(
Formula
8
)
The formula 4 represents a synthetic impedance Z in a CR parallel equivalent circuit, the formula 5 represents a resistance r in the CR parallel equivalent circuit, the formula 6 represents a reactance x in the CR parallel equivalent circuit, the formula 7 represents a resistor R in the CR parallel equivalent circuit, and the formula 8 represents capacitance C in the parallel equivalent circuit.
FIG. 11 shows the electric state between the lower electrodes 16 of the cell culture vessel by means of the equivalent circuit. There exists the medium containing the cells between the electrodes 16 . The capacitance (C) 17 configured using the medium as an inter-electrode dielectric and the electric resistor (R) 18 connect in parallel between the electrodes 16 before the cells migrate into the gap between the electrodes. Specifically, the count of the cells, which are locally immobilized may be estimated based on the degree, to which the impedance between the lower electrodes of the cell culture vessel. Moreover, when the locally immobilized cells divide and grow, the impedance increases; this makes it possible to estimate the cell growth progress. Accordingly, electric signals may be used to assess the cell growth progress easily and rapidly with no observation under an optical microscope.
Third Embodiment
With respect to the third embodiment of the present invention, the gap distance between the electrodes of the cell immobilizing mechanism, applied voltage, and applied frequency are explained.
An electric field intensity E between the electrodes of the cell immobilizing mechanism may be represented by the formula 9.
[
Mathematical
formula
9
]
E
=
V
d
(
Formula
9
)
Where, E is the electric field intensity, V is the applied voltage, and d is the gap distance. Water, which is a principal component of the medium for the cell culture, undergoes electrolysis theoretically at 1.23 V; thereby, the applied voltage V need to be set to 1.23 V and preferably, it is equal to and higher than 1 V. However, a lower applied voltage has a disadvantage that it induces only a weak dielectrophoretic force, taking long time for cell growth; accordingly, the lower limit of the applied voltage is preferably approx. 20 mV from the practical view. Moreover, when the cells are manipulated using the thin film electrodes, the electric field intensity E need to be equal to or higher than 1×10 4 V/m; thereby gap distance d between electrodes becomes equal to or lower than 123 μm. Furthermore, in the case of the cells, the average diameter of them is 10 μm; accordingly, the gap distance between the electrodes is preferably 20 to 30 μm. The formula 10 represents the amplitude of the impedance between the aforementioned electrodes.
[
Mathematical
formula
10
]
Z
=
d
s
1
σ
m
2
+
(
2
π
f
ɛ
0
ɛ
m
)
2
(
Formula
10
)
Where S is the facing surface areas of the electrodes. As known from the formula 10, with d between the electrode gaps being constant, the larger the applied frequency f, the smaller the impedance. Specifically, applying high frequency decreases the resistance between the electrodes, causing a larger current to flow. This elevates the medium temperature, causing the environment appropriate for cell culture to be deteriorated or a current control system to be complicated. In addition, considering the technique for achieving a high frequency apparatus, to gain a practical dielectrophoretic force, the applied frequency is preferably equal to or lower than 10 MHz. However, with a lower applied frequency, electrolysis of water occurs readily; accordingly, the lower limit is preferably approx. 100 Hz.
Fourth Embodiment
With respect to the fourth embodiment, another cell culture vessel of the present invention is explained by reference to FIGS. 12 and 13 .
In the fourth embodiment, an expansion mechanism 3 A shown in FIG. 12 and a side electrode 3 B shown in FIG. 13 are the same as those in the first embodiment. Hereinafter, the same signs are assigned to the same parts as those described with respect to the first embodiment to omit duplicated explanation and only different parts will be explained.
In the cell culture vessel configured as shown in FIG. 12 , to detach the cultured and grown cell, the upper electrode 3 is caused to come into contact with the top surface of the medium 5 A by means of an expansion mechanism, and turns the switch 13 B OFF and the switch 13 A ON. This operation applies a DC electric field between the lower electrode 4 and the upper electrode 3 from the power source 12 . Applying an appropriate voltage enables the cells to be detached from the culture surface through the effect of electrolysis occurring on the surface of the lower electrode.
In the cell culture vessel shown in FIG. 13 , the electrodes of the detachment mechanism are disposed on the side surface of the cell culture vessel. Moreover, the switch 13 B is turned OFF and the switch 13 A is turned ON. This operation applies a DC electric field between the lower electrode 4 and the upper electrode 3 from the power source 12 . Applying an appropriate voltage enables the cells to be detached from the culture surface through the effect of electrolysis occurring on the surface of the lower electrode.
Example 1
In the example 1, a castle-wall electrodes are used for cell immobilization, cell count measurement, and cell growth progress measurement. FIG. 14 shows the state of the medium after cell seeding and FIG. 15 shows the state of the medium after cell growth. In the example 1, 3T3 cells (cultivated strain of the fibroblast cells derived from mouse skin), and the DMEM medium with calf serum and an antibiotic substance added are used. Note that the average diameter of 3T3 cells is 10 μm and the electric conductivity of the medium is 1200 mS/m.
FIG. 16 shows the influence of the applied voltage of 0.1 V on changes in impedance between the electrodes with the gap distance between the electrodes of 20 m. As known from FIG. 16 , the impedance of the medium containing the 3T3 cells is higher than that of the medium alone. It is because the 3T3 cells have been immobilized in the weak electric field by the negative dielectrophoretic force. FIG. 17 shows a time-course change in impedance between the electrodes at the applied voltage of 0.1 V and the applied frequency of 1 KHz. The impedance between the electrodes clearly increased over time. This suggests that the cells in the medium are rapidly immobilized in the weak electric field between the electrodes. Moreover, comparison of this change in impedance with the result of microscopic observation gives the impedance count for each cell; accordingly, the count of the immobilized cells between the electrodes may be found based on the change in impedance.
With respect to the example 1, the result of the use of the 3T3 cells and the DMEM medium have been explained; however, the use of the cells derived from any other animal of comparable size and another medium with electric conductivity equivalent to that of the DMEM medium may give the same result.
As known from FIG. 16 , after the cells are cultured for 24 hours at 37° C. while the mixed gas of air, 5% CO 2 , and 100% water is being flown into the cell culture vessel the impedance between the electrodes further increases. This increase in impedance between the electrodes may be associated with the increased count of the cells after cell growth. Taking advantage of this phenomenon, the cell growth progress may be easily determined using the electric signals.
Example 2
With respect to the example 2, the result of an experiment, in which the cultured cells are detached from the medium surface using the detachment mechanism of the present invention. Since the experimental conditions are the same as those of the example 1, the explanation of them is omitted. After 24-hour culture, 0.5 V of voltage was applied between the upper electrode 3 and lower electrode 4 of the cell culture vessel from the DC power source 12 . Two hours after applying the voltage, it was observed that the cells were gradually detached away from the medium surface. To facilitate this detachment step, the applied voltage may be increased; however, it is concerned about the possibility of damage to the cells due to strong electrolysis. Taking advantage of this phenomenon, the cells may be detached with no need for an enzyme for detachment as with conventional techniques, for example trypsin, reducing the running cost.
On the other hand, no technique method for concentrating the cells using dielectrophoresis has been reported.
With respect to the example 3 and its succeeding examples, an apparatus for concentrating the cells in the medium efficiently with less load on the cells using negative dielectrophoresis is explained.
Example 3
One configuration of the cell concentrating apparatus according to the example 3 of the present invention is explained by reference to FIG. 18 .
In FIG. 18, 101 is a piston-type incubator, 102 are concentrating electrodes containing electrode couples 102 a and 102 b disposed on the bottom surface of the piston-type incubator 101 . 103 is an AC power source, 104 is a switch between the concentrating electrode 102 and the AC power source 103 . 105 is a cell suspension vessel and 106 is the medium containing cells 107 . 108 is a driving mechanism equipped with a support mechanism 108 A. 109 is a discharge mechanism equipped with a discharge tube 110 .
The concentrating electrode 102 disposed on the bottom surface of the piston-type incubator 101 may be formed directly of, for example metal wire, or may be formed by evaporating or fixing a metal material on a solid insulating substrate made of any of materials such as glass, silicone, quartz, plastics, and polymers and then forming a through hole between the electrodes. Moreover, it is desired that any of materials capable of suppressing the chemical reaction with the medium and the influence on the cells is used for the aforementioned electrodes and the support member. The allowable materials for the electrodes include platinum, gold, chromium, palladium, silver, aluminum, tungsten, and ITO, or any combination of them. It goes without saying that the cross-sectional shape of the concentering electrode is preferably circular but may be other shapes such as rectangle and polygon.
Generally, ion-rich media with high conductivity (1000 mS/m or higher) is used for culturing the cells, especially animal cells. FIG. 19 is a view showing the relationship between the frequency of the AC electric field and real part Re [K] of the Claudius-Mossotti number. In this figure, the results of dielectrophoresis are shown for each of media with electric conductivity of 0.1, 1, 10, 100, and 1000 mS/m. In the figure, the areas, where the dielectrophoretic force F DEP is positive and negative, are also shown. As known from this figure, with the media with electric conductivity equal to or higher than 1000 mS/m, dielectrophoresis becomes negative at the frequency equal to or lower than 10 9 Hz in all cases. Specifically, the cells migrate in the direction away from the center of the electric field, namely toward the weak electric field. Note that since the dielectrophoretic force is proportional to the amplitude of Re [K], the applied frequency is preferably equal to or lower than 10 7 Hz.
By reference to FIG. 20 , the principle of cell concentration will be explained. A gravity force G, buoyant force F B , and viscous force F DRAG are exerted on the cells 107 seeded on the medium 106 . In this case, when the concentrating electrode 102 , to which the AC voltage is applied, approaches the cells 107 , the dielectrophoretic force F DEP is further exerted thereon. When the concentrating electrode 102 is inserted down into the cell suspension vessel 105 vertically from the top side, the cells 107 contained in the medium move toward the bottom of the cell suspension vessel 105 together with the concentrating electrode 102 , provided that the condition F DEP +G>F B is met. At the same time, the medium passes through the gap between the concentrating electrodes 102 to the piston-type incubator 101 , in which the medium is discharged. Thus, cell concentration may be achieved.
With respect to the example 3, the technique for inserting the concentrating electrode 102 down into the cell suspension vessel 105 vertically from the top side has been described; however, it goes without saying that the concentrating electrode 102 may be inserted from the bottom side or the lateral side. Insertion of the concentrating electrode 102 into the cell suspension vessel 105 from the top side is preferable because it improves cell concentration efficiency by exerting the gravity force G and the dielectrophoretic force from their individual directions.
By reference to FIGS. 21A to 21D , the flow of the process of concentrating the cells according to the example 3 will be explained. First, as shown in FIG. 21A , the switch 104 is closed and an AC voltage is applied to the concentrating electrode 102 . Second, as shown in FIG. 21B , the driving mechanism 108 moves the piston-type incubator 101 into the cell suspension vessel 105 . The cells 107 are pressed down against the bottom surface of the cell suspension vessel 105 and coagulate thereon, while the medium 106 passes through the through-hole of the concentrating electrode 102 and moves upward. Third, shown in FIG. 21C , the medium 106 , which moved upward, is discharged outside from the cell suspension vessel 105 by means of the discharge mechanism 109 and the discharge tube 110 . Finally, as shown in FIG. 21D , the switch 104 is opened to return the piston-type incubator 101 back to its original position shown in FIG. 21A by means of the driving mechanism 108 . This operation allows for concentrating the cell suspension in the cell suspension vessel 5 .
Herein, the gap distance between the concentrating electrodes 102 , and the applied voltage and applied frequency are explained.
The electric field intensity E between cell concentrating electrodes is represented by the above formula 9.
Water, which is a principal component of the medium for cell culture, undergoes electrolysis theoretically at 1.23 V; thereby, the applied voltage need be set to 1.23 V or lower. Moreover, as shown in the formula 1, since the dielectrophoretic force is proportional to the applied voltage. At the applied voltage lower than 20 mV, the dielectrophoretic force becomes smaller, namely the force for driving the cells is decreased; accordingly, the applied voltage is preferably equal to or higher than 20 mV.
To manipulate the cells, the electric field intensity E equal to or higher than 1×10 4 V/m is required, resulting in the gap distance d between the electrodes being equal to or lower than 123 μm. Furthermore, for the animal cells, of which average diameter is 10 μm, the gap distance between the electrodes is preferably within the range from 20 to 30 μm.
The above formula 10 represents the amplitude of the impedance between the aforementioned electrodes.
In the formula, S is the area between the opposing electrodes. As known from the formula 10, assuming that the gap distance d between the electrodes is constant, the larger the applied frequency f, the smaller the impedance. Specifically, when high frequency is applied, the resistance between the electrodes, increasing flowing current. This elevates the medium temperature, causing the environment appropriate for cell culture to be deteriorated or a current control system to be complicated. In addition, considering the technique for achieving a high frequency apparatus, the applied frequency is preferably equal to or lower than 10 MHz. However, with higher electric conductivity of the medium, electrolysis of water occurs even when low-frequency AC voltage is applied; accordingly, the applied voltage is preferably equal to or higher than 100 MHz.
According to the example 3 of the present invention, the cell concentrating apparatus of the present invention is capable of concentrating the cells easily and efficiently by means of dielectrophoretic force, rather than the conventional membrane separation process, centrifuge separation method, and precipitation separation method.
Example 4
The example 4 of the present invention measures the impedance between the concentrating electrode and the bottom surface electrode of the present invention to determine the cell concentration. The example 4 is explained by reference to FIG. 22 . Hereinafter, the same signs are assigned to the same parts as those described in the example 3 to omit their explanation and only the different parts are explained.
113 is a bottom surface electrode disposed on the bottom surface of the cell suspension vessel, 111 is an impedance measuring apparatus electrically connected to the bottom surface electrode 113 , and 112 is a switch connecting the concentrating electrode 102 and the impedance measuring apparatus. 114 is a position sensor of the concentrating electrode, and 115 is magnetic sheet for the position sensor.
The flow of a process of measuring the cell concentration according to the example 4 of the present invention is explained by reference to FIGS. 23A to 23D . First, as shown in FIG. 23A , the switch 104 is closed and the switch 112 is opened. Second, as shown in FIG. 23B , the driving mechanism 108 moves the piston-type incubator 101 toward the cell suspension vessel 105 . The cells 107 are coagulated on the bottom surface of the cell suspension vessel 105 by means of dielectrophoresis, while the medium 106 passes through the through-hole of the concentrating electrode 102 and moves upward. Third, as shown in FIG. 23C , the medium 106 , which moved upward, is discharged outside from the cell suspension vessel 105 by means of the discharge mechanism 109 and the discharge tube 110 . At this point, the switch 104 is opened and the switch 112 is closed. The impedance measuring apparatus 111 measures the impedance between the concentrating electrode 102 and the bottom surface electrode 113 to estimate the count of the cells contained in the medium. Moreover, the position sensor 114 measures the volume of the cell suspension. This allows for measurement of the concentration of the concentrated cells. Finally, as shown in FIG. 23D , the switch 112 is opened to return the piston-type incubator 101 back to its original position shown in FIG. 23A by means of the driving mechanism 108 . This operation allows for concentrating the cell suspension in the cell suspension vessel 105 and measuring the concentration of the concentrated cells.
Herein, the method for determining the cell concentration by measuring the impedance between the concentrating electrode 102 and the bottom surface electrode 113 is explained.
Hereinafter, the impedance Z between the concentrating electrode and the bottom surface electrode is explained by reference to FIG. 24 and the above formulas 4 to 8.
In the formulas, the capacitance is represented by C, the reactance is represented by x, the resistance is represented by r, and the resistor is R.
The formula 4 represents the synthetic impedance Z in the CR parallel equivalent circuit, the formula 5 represents the resistance r in the CR parallel equivalent circuit, the formula 6 represents the reactance x in the CR parallel equivalent circuit, the formula 7 represents the resistor R in the CR parallel equivalent circuit, and the formula 8 represents the capacitance C in the CR parallel equivalent circuit.
FIG. 24 shows the electric state between the lower electrodes 116 of the cell culture vessel by means of an equivalent circuit. There exists the medium containing the cells between the electrodes 116 . The capacitance (C) 17 configured using the medium as an inter-electrode dielectric and the electroconductive resistor (R) 18 connect in parallel between the electrodes 116 before the cells migrate into the gap between the electrodes.
The medium is homogenous liquid. In contrast, the cell is enclosed with an almost insulating cell membrane and therefore, large differences in capacitance and resistance are observed between the cell and the medium. Specifically, the capacitance and resistance of the medium have been measured in advance and when the cells are seeded in the medium, the cell count is determined based on the changes in capacitance and resistance. Since the impedance may be assessed based on the capacitance and resistance, the cell count may be estimated based on the impedance by assessing, in advance, the relationship between the cell count and the impedance. In other words, the cell count may be estimated based on the impedance between the concentrating electrode and the bottom surface electrode.
Example 5
By reference to FIG. 25 , the cell concentration system according to the example 5 of the present invention.
In FIG. 25 , the parts excluding a control processor 119 and a monitor 120 are the same as those explained with respect to the example 4. Note that the broken line in FIG. 25 is an electric signal line connecting the control processor 119 to individual electric control parts.
The cell concentration system shown in FIG. 25 is capable of controlling and monitoring the steps of concentrating the cells and measuring the cell concentration explained above with respect to the example 4. First, the switch 104 is closed and the switch 112 is opened. Second, the driving mechanism 108 moves the piston-type incubator 101 to the cell suspension vessel 105 . Third, the medium 106 is discharged outside of the cell suspension vessel 105 by means of the discharge mechanism 109 and the discharge tube 110 . At this point, the switch 104 is opened and the switch 112 is closed. The impedance measuring apparatus 111 measures the impedance between the concentrating electrode 102 and the bottom surface electrode 113 to estimate the count of the cells contained in the medium. Moreover, the position sensor 114 measures the volume of the cell suspension. This allows for measurement of concentration of the concentrated cells. Finally, the switch 112 is opened to return the piston-type incubator 101 to its original position by means of the driving mechanism 108 . This operation enables the cell suspension contained in the cell suspension vessel 105 to be concentrated and the concentration of the concentrated cells to be measured. At this point, the driving speed of the driving mechanism 108 , and the position of the concentrating electrode, the volume of the cell suspension, and cell concentration may be monitored.
Taking advantage of the above functions, the cells may be concentrated to the target level. The flow sheet of controlling the process is shown in FIG. 26 . First, in the first step ST 1 , it is determined whether or not the cell concentration is the target one. If it is target one, the process goes to the step ST 2 for opening the switch 104 and the switch 112 . When the step ST 2 is finished, control is transferred to the main routine in the step ST 5 . On the other hand, if the cell concentration is not target one, the process goes to the step ST 3 of concentrating the cells contained in the medium by opening the switch 104 , turning the AC power source 103 ON, and moving the driving mechanism 108 down. Moreover, the process goes to the step ST 4 of opening the switch 104 and closing the switch 112 , turning the AC power source OFF and the impedance measuring apparatus 111 ON to measure the impedance and the position. The step ST 3 for concentrating the cells to the target cell concentration and the step ST 4 of measuring the impedance and the position are repeated until the condition set in the step ST 1 is met.
Example 6
A cell concentration apparatus according to the example 6 of the present invention is explained by reference to FIGS. 27A to 27C . Herein after, the same signs are assigned to the same parts as those explained with regard to the examples 3 and 4 to omit the explanation of them and only different parts are explained.
According to the example 6, the concentrating electrode 102 is disposed on the wall of the cell suspension vessel 105 in the form of multi-layer electrodes 102 A to 102 C. The corresponding one of switches 104 A to 104 C is disposed between each of the concentrating electrode 102 A to 102 C and the AC power source 103 .
The flow of the process for concentrating the cells according to the example 6 is explained by reference to FIGS. 27A to 27C . First, as shown in FIG. 27A , the switch 104 A is closed, the switch 104 B is opened, the switch 104 C is opened, and an AC voltage is applied to the concentrating electrode 102 A to coagulate the cells at the bottom of the concentrating electrode 102 A. Second, the switch 104 A is opened, the switch 104 B is closed, the switch 104 C is opened, and an AC voltage is applied to the concentrating electrode 102 B to coagulate the cells at the bottom of the concentrating electrode 102 B. Third, as shown in FIG. 27B , the switch 104 A is opened, the switch 104 B is opened, the switch 104 C is closed, and an AC voltage is applied to the concentrating electrode 102 C to coagulate the cells at the bottom of the concentrating electrode 102 C. Finally, as shown in FIG. 27C , the medium 106 on the concentering electrode 102 C may be discharged outside of the cell suspension vessel 105 by means of the discharge mechanism 109 and the discharge tube 110 . It goes without saying that three-layer concentrating electrode has been explained with regard to the example 6, but a two-layer or four layer or more concentrating electrode may be used.
Focusing on cell concentration, the present invention has been explained. The principle of the apparatus and the system of the present invention may be inversely used to dilute the cell suspension to the target concentration.
As long as the features of the present invention are not lost, the present invention is not limited to the aforementioned embodiments and examples and includes other embodiments, which may be considered within the scope of the technical idea of the present invention.
Hereinafter, the embodiments of the present invention are summarized and recited.
(1) A cell concentration apparatus for concentrating cells contained in a medium, which includes a cell suspension vessel that supports the media containing the cells, a piston-type incubator moving toward the cell suspension vessel, an electrode disposed on the bottom surface of the piston-type vessel, a through-hole, which pierces through the bottom surface of the piston-type incubator disposed between the electrodes, a power source that applies an AC voltage to the electrode, a driving mechanism that moves the piston-type incubator up from and down to the cell suspension vessel, and a discharge mechanism that discharges the medium, which enters the piston-type vessel through the through-hole.
(2) The cell concentrating apparatus described in (1) which is characterized in that the electrode disposed on the bottom surface of the piston-type incubator presses the cells in a cell suspension against the bottom of the cell suspension vessel by means of a diectrophoretic force.
(3) The cell concentrating apparatus described in (1) which further includes an impedance measuring apparatus that measures the impedance between the electrode disposed on the bottom surface of the piston-type incubator and the electrode disposed on the bottom surface of the cell suspension vessel to estimate the count of the cells in the medium based on the measured impedance.
(4) The cell concentrating apparatus described in (3), which further includes a position sensor that measures the position of the electrode, in which it finds the volume of the cell suspension based on the measured electrode position to determine the cell concentration.
(5) The cell concentration apparatus for concentrating the cells contained in the medium, characterized by including a cell suspension vessel that supports the medium contained the cells, a plurality of electrodes disposed on the inner wall of the cell suspension vessel in the multi-layer form, a through-holes formed between the electrodes, a power source that applies an AC voltage to the electrode, a switch that switches among the plurality of electrodes to which the AC voltage is applied, and a discharge mechanism that discharges the medium which enters the cell suspension vessel.
(6) The cell concentrating apparatus described in (5) which is characterized in that the plurality of electrodes disposed on the inner wall of the cell suspension vessel in the multi-layer form presses the cells in the cell suspension against the bottom of the cell suspension vessel by means of a negative dielectrophoretic force.
(7) The cell concentrating apparatus described in any one of (1) to (6) which is characterized in that the voltage applied for generating an electric field between the electrodes is within the range from 20 mV to 1.23 V.
(8) The cell concentrating apparatus described in any one of (1) to (6) which is characterized in that the frequency applied for generating an electric field between the electrodes is within the range from 100 Hz to 10 MHz.
(9) The cell concentrating apparatus described in any one of (1) to (6) which is characterized in that the gap distance between the electrodes is equal to or less than 123 μm.
(10) The cell concentrating apparatus described in any one of (1) to (6) which is characterized in that the electrodes are made of any one of platinum, gold, chrome, palladium, rhodium, silver, aluminum, tungsten, and ITO, or any combination of them.
(11) A cell concentrating system composed of a cell concentrating apparatus described in any one of (1) to (6); and a control processor that controls the individual parts of the cell concentrating apparatus.
(12) A method for concentrating cells using a cell concentrating apparatus described in one of (1) and (2), which includes: supplying a medium containing cells in the cell suspension vessel; moving the piston-type incubator downward while applying an AC voltage to the electrode; and discharging the medium, which enters the piston-type incubator through the through-holes.
(13) A method for concentrating the cells using the cell concentrating apparatus described in (4), which includes: supplying the medium containing the cells in the cell suspension vessel; moving the piston-type incubator downward while applying an AC voltage to the electrode; and discharging the medium, which enters the piston-type incubator through the through-holes; measuring the impedance between the electrode disposed on the bottom surface of the piston-type incubator and the electrode disposed on the bottom surface of the cell suspension vessel using the impedance gauge and finding the volume of the cell suspension using the position sensor; finding the cell concentration based on the measured impedance and volume of the cell suspension; and ending the cell concentration process if the found cell concentration has reached the target level, and going to the step of moving the piston-type incubator downward if it is lower than the target level.
(14) A method for concentrating the cells using the cell concentrating apparatus described in one of (5) and (6), which includes: supplying the medium containing the cells in the cell suspension vessel; switching among the electrodes arranged in the multi-layer form to apply the AC voltage to them sequentially from one end; and discharging the medium, which enters the cell suspension vessel through the through-holes.
Note that according to the above-recited embodiments of the present invention, the cells contained in the medium may be concentrated efficiently with less load on them. The cell concentration may be measured by means of electric signals.
REFERENCE SIGNS LIST
1 . . . Incubator ceiling substrate, 2 . . . Incubator bottom substrate, 3 . . . Upper electrode, 3 A . . . Expansion mechanism, 3 B . . . Side electrode, 4 . . . Lower electrode, 5 . . . Inside of the incubator, 5 A . . . Culture medium, 5 B . . . Cell, 6 . . . Medium inlet, 6 A . . . Medium inlet valve, 7 . . . Medium outlet, 7 A . . . Medium outlet valve, 8 . . . Mixed-gas inlet, 8 A . . . Mixed-gas inlet valve, 9 . . . Mixed-gas outlet, 9 A . . . Mixed-gas outlet valve, 10 . . . AC power source, 11 . . . Impedance measuring apparatus, 12 . . . DC power source, 13 A . . . Switch, 13 B . . . Switch, 14 . . . Switching element, 15 A . . . Driving circuit, 15 B . . . Driving circuit, 15 C . . . Driving circuit, 16 . . . Electrode, 17 . . . Capacitance C, 18 . . . Resistor R, 101 . . . Piston-type incubator, 102 . . . Concentrating electrode, 103 . . . AC power source, 104 . . . Switch, 105 . . . Cell suspension vessel, 106 . Medium, 107 . . . Cell, 108 . . . Driving mechanism, 108 A . . . Support mechanism, 109 . . . Discharge mechanism, 110 . . . Discharge tube, 111 . . . Impedance measuring apparatus, 112 . . . Switch, 113 . . . Bottom surface electrode, 114 . . . Position sensor, 115 . . . Magnetic sheet, 116 . . . Electrode, C 17 . . . Capacitance C, R 18 . Resistor R, 119 . . . Control processor, 120 . . . Monitor. | Disclosed is a cell culture vessel of the present invention, which is composed of a space enclosed by a housing that supports a medium and a cell attachment part, disposed on the bottom surface of the space, that attaches and supports the cells, the cell attachment part having a cell immobilizing mechanism that guides the cells in the space to the cell attachment part to immobilize there and a cell detachment mechanism that detaches the cells attached in the cell attachment part, the cell immobilizing mechanism having a step of applying a voltage to an electrode disposed in the cell attachment part to generate a heterogeneous electric field in the space, and the cell detachment mechanism having a step of applying a voltage to an electrode disposed in the cell attachment part to induce electrolyte in the space. | 2 |
TECHNICAL FIELD
[0001] The present invention relates to a storage system and, more specifically, to a method for creating and managing hierarchically managed logical volume snapshots in a storage system.
BACKGROUND ART
[0002] In storage systems, data (files) are hierarchically managed using relatively fast, higher-level storage such as a hard disk drive (HDD), and relatively slow, lower-level storage such as a tape drive. In storage systems, logic volume management (LVM) is also performed using logical volumes logically segmented into volume groups of more than one logical volume.
[0003] In copy services providing various types of storage subsystems, file systems and applications in addition to this type of storage management, techniques are used to store images of data at a certain instant (hereinafter referred to as “Time 0”). Examples of these techniques include snapshots and flash copies. The detailed mechanisms of this technique differ depending on the hardware and software being used but pointer information at locations where files (data) are being stored at Time 0 is generally saved, and this pointer information is used to manage the original files and images created at Time 0. In the following explanation, the term “snapshot” is used synonymously with “flash copy”.
[0004] Existing snapshots are valid only for files stored on the disk at Time 0, and a snapshot cannot be created when the target file is not present on the disk. In other words, snapshots are of a disk on a single level, and can be created and managed by creating and using pointer data when valid data is present on the disk. A snapshot cannot be created if data is not present on the disk.
[0005] However, when files are hierarchically managed using a disk and physical tape, valid data is sometimes present on the physical tape even when there is no valid data present on the disk. Also, data can be moved from disk to physical tape hierarchically. When files are hierarchically managed in these situations, it is difficult to create and manage snapshots by using the simple pointer information archived by the conventional snapshot functions.
[0006] Patent Literature 1 describes a file management method for hierarchical management of files using a disk and physical tape which includes snapshot files using i-nodes of each source file and i-nodes of each snapshot file for each source file. However, Patent Literature 1 does not describe a method for creating and managing snapshots when no valid data is present on the disk but valid data is present on physical tape.
SUMMARY OF INVENTION
[0007] Therefore, it is an object of the present invention to provide a method for creating and managing snapshots of hierarchically managed logical volumes even in situations in which there is no valid data on a disk but there is valid data on a physical tape.
[0008] The present invention is a method for creating and managing snapshots of hierarchically managed logical volumes in a storage system. The storage system includes first level storage and second level storage lower than the first level storage. This method includes the steps of:
[0009] (a) receiving a command for creating a snapshot of the logical volume;
[0010] (b) preparing a management table for managing the snapshot, the management table including first metadata indicating the creation status of the snapshot, second metadata indicating the management status of the snapshot, and third metadata indicating the storage location of the logical volume;
[0011] (c) detecting the storage status of the logical volume; and
[0012] (d) updating the management table without recalling the logical volume from the second level storage to the first level storage when the logical volume has migrated from the first level storage to the second level storage, the first metadata indicating that creation of a snapshot is required, the second metadata indicating that the logical volume has migrated, and the third metadata indicating that the second level storage is the storage location of the logical volume.
[0013] By updating and reusing a management table to manage a snapshot, the present invention is able to create and manage a snapshot of hierarchically managed logical volumes when the logical volume has migrated from the first level storage to the second level storage without directly having to immediately recall the logical volume from the second level storage to the first level storage.
[0014] The method in one aspect of the present invention also includes the steps of:
[0015] (e) recalling the logical volume when access to the logical volume or the snapshot is requested;
[0016] (f) creating a snapshot from the logical volume recalled to the first level storage; and
[0017] (g) updating the management table, the first metadata indicating that the snapshot has been created, the second metadata indicating that the logical volume has pre-migrated, and the third metadata indicating that the second level storage is the storage location of the logical volume.
[0018] By creating a snapshot and updating and reusing a management table when access to a logical volume or snapshot is requested, one aspect of the present invention is the ability to respond to the access request and properly manage the snapshot afterwards.
[0019] The method in one aspect of the present invention also includes the step of:
[0020] (h) updating the management table when overwriting of the logical volume or deletion of the logical volume is requested, the first metadata indicating that creation of a snapshot is not required, the second metadata indicating that the logical volume has migrated, and the third metadata indicating that the second level storage is the storage location of the logical volume.
[0021] By not requiring the creation of a snapshot and keeping the second level storage as the storage location of logical volume, one aspect of the present invention is the ability to create and manage logical volumes and their snapshots stored in this location when the overwriting or deletion of a logical volume previously used in a command to create a snapshot is requested.
[0022] The method in one aspect of the present invention also includes the step of:
[0023] (i) updating the management table when overwriting of the snapshot is requested, the first metadata indicating that creation of a snapshot is not required, the second metadata indicating that the logical volume is located in the first level storage, and the third metadata indicating that deletion has been performed.
[0024] The method in one aspect of the present invention also includes the step of:
[0025] (j) updating the management table when deletion of the snapshot is requested, the first metadata indicating that deletion has been performed, the second metadata indicating that deletion has been performed, and the third metadata indicating that deletion has been performed.
BRIEF DESCRIPTION OF DRAWINGS
[0026] FIG. 1 is a diagram showing a configuration example of a storage system used by the method of the present invention.
[0027] FIG. 2 is a diagram showing an example of a data storage status.
[0028] FIG. 3 is an image diagram showing a snapshot that was created in the situation shown in FIG. 2 .
[0029] FIG. 4 is a flowchart of the method of the present invention.
[0030] FIG. 5 is a diagram showing an example of a management table prepared in Step S 2 of FIG. 4 .
[0031] FIG. 6 is a diagram showing the management table after an update.
[0032] FIG. 7 is a diagram showing the management table after an update.
[0033] FIG. 8 is a diagram showing the management table after an update.
[0034] FIG. 9 is a diagram showing the management table after an update.
[0035] FIG. 10 is a diagram showing the management table after an update.
[0036] FIG. 11 is a diagram showing the management table after an update.
[0037] FIG. 12 is a diagram showing the management table after an update.
DETAILED DESCRIPTION
[0038] The following is an explanation of an embodiment of the present invention with reference to the drawings. FIG. 1 is a diagram showing a configurational example of a storage system used by the method of the present invention. The storage system 10 includes first storage 101 and second storage 102 which can communicate so as to enable communication. FIG. 1 shows a configuration with the minimal requirements for hierarchical management. The storage system 10 can be connected to multiple hosts (servers), and can include multiple units of first storage 101 and second storage 102 . A configuration including the storage system 10 and the host 20 can serve as an entire system 1 (for example, a data system, or data management system) or as part of a system.
[0039] In one embodiment, the first storage 101 in the storage system 10 can be storage including a higher level disk (sometimes referred to as the disk cache or HDD below), and the second storage 102 can be storage including lower level physical tape (tape drive). The configuration (or combination) of first and second storage can be any hierarchically organized combination and is not restricted to combinations of disks and physical tape. In the following explanation, the storage system is Virtual Tape Server TS7700® provided by the applicant, International Business Machines Corporation. (hereinafter referred to as the TS7700.) The TS7700 can include, as a minimal configuration, the disk cache and physical tape illustrated in the storage system 10 of FIG. 1 .
[0040] FIG. 2 shows the storage states of data in the TS7700. The data written from the host 20 is written to the disk cache 101 in units known as “logical volumes” 30 . As mentioned above, logical volumes 30 are segmented logically into volume groups composed of more than one physical volume. The host 20 issues a mount command for a logical volume 30 , and the logical volume 30 is read or written. The host 20 then rewinds, unloads, and ends access. After access has been ended, the data is moved from the disk cache 101 to physical tape 102 and hierarchically managed according to the policies established by the user for each logical volume 30 .
[0041] As shown in FIG. 2 , data 40 inside the TS7700 is stored in one of the following three storage states.
[0042] A: Present only in the disk cache 101
[0043] B: Present both in the disk cache 101 and on physical tape 102
[0044] C: Present only on physical tape 102
[0000] A transition from storage state A to storage state B is referred to as pre-migration, a transition from storage state B to storage state C is referred to as migration, and transition from storage state C to storage state B is referred to as a recall.
[0045] In the TS7700, data in the disk cache is read and written via the General Parallel File System® (GPFS). The GPFS provides a snapshot function on both the file system level and the individual file level. In the following explanation, the logical volume which is the source of a snapshot is referred to as the original data and the image of the logical volume created at Time 0 is referred to as the snapshot.
[0046] FIG. 3 shows an image when a snapshot has been created at Time 0 using a function provided by GPFS with regard to the storage states A, B and C shown in FIG. 2 . In FIG. 3 , block 50 delineated by dotted lines is a snapshot of data 40 . Because data 40 is present in the disk cache 101 in storage states A and B, it can create a snapshot 50 properly at Time 0.
[0047] Because data is not present in the disk cache 101 in storage state C, a snapshot cannot be created using GPFS even when there is valid (the latest) data 40 present on the physical tape 102 . Therefore, in order to create a snapshot of data in storage state C at Time 0, an operation has to be performed in advance to recall data on the physical tape and write the data to the disk cache 101 .
[0048] However, in the TS7700, a maximum of 2 million logical volumes can be defined. When there is a large amount of migrated logical volumes, it can take a long time to recall all of the logical volumes. Therefore, Time 0 itself cannot be defined. Also, all volumes cannot be recalled at once because of the limited disk cache capacity. Therefore, it is inappropriate and practically impossible to recall data on the physical tape in advance. This particular problem is to be solved by the method of the present invention explained in detail below.
[0049] The following is an explanation with reference to FIG. 4 of the operational flow of the method of the present invention which is used to create and manage a snapshot of hierarchically managed logical volumes. The operational flow in FIG. 4 is embodied in the configuration shown in FIG. 1 by software executed by a computer (controller) in the storage system 10 .
[0050] In Step S 1 , a command is received from the host to create a snapshot of the logical volumes. More specifically, the user issues a command to the storage system via the host or a management interface. In Step S 2 , a management table is prepared for managing the snapshot. More specifically, a DB2® table is prepared (duplicated) for the snapshot. Here, a DB2 table refers to a DB2 table defined by the TS7700 as a relational database. The DB2 table includes various types of metadata used to manage the snapshot as explained below.
[0051] FIG. 5 is an example of a management table (DB2 table) prepared in Step S 2 . In the management table, LVOL_TOK, LVOL and LVOL_TO_PVOL in line 1 through line 3 include metadata information described below that is related to the original data (logical volumes), and LVOL_TOK_SNAP, LVOL_SNAP and LVOL_TO_PVOL_SNAP in line 4 through line 6 include metadata information described below that is related to the snapshot.
[0052] (a) LVOL_TOK: This holds the status of each logical volume (whether or not the most recent data is present, etc.). An entry is created when the user defines a logical volume irrespective of whether the data is located on the disk or the physical tape.
[0053] (b) LVOL: This holds information indicating in which physical volume the logical volume is located (whether or not the data is migrated or pre-migrated). As in the case of LVOL_TOK, an entry is created when the user defines a logical volume irrespective of whether the data is located on the disk or the physical tape.
[0054] (c) LVOL_TO_PVOL: When each logical volume is migrated or pre-migrated, this holds information indicating whether or not the logical volume is located on physical tape. An entry is created when a logical volume has pre-migrated to physical tape.
[0055] In the example shown in FIG. 5 , the management table is for logical volumes (original data) which have already migrated and are present only on physical tape. As a result, “migrated” is indicated for LVOL in line 2, and physical volume PVOLX is indicated as the storage location of the migrated logical volume (original data) for LVOL_TO_PVOL in line 3. LVOL_TOK in line 1 indicates that a snapshot (snap) does not have to be created of the initial state. LVOL_TOK_SNAP, LVOL_SNAP and LVOL_TO_PVOL_SNAP in line 4 through line 6 are not applicable (NA) in the initial state.
[0056] Returning to FIG. 4 , the storage state of the logical volumes (original data) are detected in Step S 3 . More specifically, it is detected whether or not the logical volumes are in state A, B or C shown in FIG. 2 . In Step S 4 , it is determined whether or not the logical volumes (original data) has migrated. If the determination is YES, there is no data present on the disk cache. Therefore, an actual snapshot is not created and an image cannot be obtained at Time 0 even when a command has been issued to the GPFS to create a snapshot. Thus, the management table is updated in Step S 5 without performing the processing required to create a snapshot right away.
[0057] FIG. 6 shows the management table after the update. First, “snap creation required” is recorded in LVOL_TOK and in LVOL_TOK_SNAP, which is the field indicating the current snapshot status. This indicates that another snapshot has to be created for each logical volume unit at a stage when the original data has been recalled. Then, “migrated” is recorded in both LVOL_SNAP and LVOL which indicates that the logical volumes have migrated. The physical volume PVOLX of the migrated original data is recorded in LVOL_TO_PVOL_SNAP.
[0058] When the determination in Step S 4 is NO, original data is present in the disk cache. In Step S 5 , a snapshot is created of the original data at Time 0, as shown in the examples of states A and B in FIG. 3 . The step goes to S 5 , and the management table is updated. FIG. 7 shows the updated management table after a snapshot has been created. In the management table shown in FIG. 7 , “cached” refers to storage state A in FIG. 2 in which original data is present in the disk cache 101 , and “pre-migrated” refers to storage state B in FIG. 2 in which original data is present in both the disk cache 101 and physical tape 102 .
[0059] Time 0 snapshots of all the logical volumes managed by TS7700 have been completed at this point. However, an actual snapshot image is not created at Time 0 of the logical volumes which have migrated. In the present invention, when any of the following events occurs after the Time 0 snapshot, a separate snapshot is created and managed for the migrated logical volumes. In one embodiment, the “mmcrsnapshot” command in GPFS can be used to create a snapshot at once of all of the data in the managed file system. A snapshot of separate files can be created using the “mmclone” command.
[0060] (A) if Original Data or Snapshot has been Accessed (Logical Volumes are Read and Written)
[0000] (A1) Because the host can only access files located in the disk cache, the TS7700 recalls migrated original data when the data has been accessed. When a snapshot is accessed, it is recalled from the physical tape written to LVOL_TO_PVOL_SNAP.
(A2) Original data can be accessed from the host once it has been recalled and its snapshot is created in an instant.
(A3) Afterwards, the management table is updated.
[0061] FIG. 8 shows the management table after it has been updated.
[0062] LVOL_TOK and LVOL_TOK_SNAP have been changed from “snap creation required” to “snap created”, and LVOL and LVOL_SNAP have been changed to “pre-migrated”.
[0063] (B) If Original Files Have Been Overwritten
[0064] When “Write From BOT (Beginning of Tape)” has occurred, the management table is updated in the following way. LVOL_TOK has to be changed to “snap creation required”, LVOL has to be updated to “cached” to indicate that data is present on the disk, and LVOL_TO_PVOL has to be deleted (NA). However, because an entry for the snapshot remains in LVOL_TO_PVOL_SNAP, the logical volumes of the original file present on the physical tape are not invalidated. In this case, there is no longer any need to create a snapshot, and future access is provided to the original file and snapshot as two separate files. FIG. 9 shows the management table after it has been updated.
[0065] (C) if Original Files have been Deleted
[0066] In this case, LVOL_TOK, LVOL and LVOL_TO_PVOL are deleted and the management table is updated accordingly. The status of LVOL_TOK_SNAP, LVOL_SNAP and LVOL_TO_PVOL_SNAP are the same as case (B) above. FIG. 10 shows the management table after it has been updated.
[0067] A snapshot does not have to be created if any of the following has occurred before a snapshot has been created using GPFS.
[0068] (D) if Snapshot Overwrite (Write from BOT) has Occurred
[0069] In this case, the management table is updated in the following way without any recall because a snapshot does not have to be created of the original files. LVOL_TOK and LVOL_TOK_SNAP are changed from “snap creation required” to “snap creation not required”, LVOL_SNAP is updated to “cached” indicating that data is present on the disk, and LVOL_TO_PVOL_SNAP is deleted (NA). FIG. 11 shows the management table after it has been updated.
[0070] (E) If Snapshot Deletion Has Occurred
[0071] In this case, the management table is updated in the following way. LVOL_TOK_SNAP, LVOL_SNAP and LVOL_TO_PVOL_SNAP are deleted (NA), and LVOL_TOK is changed from “snap creation required” to “snap creation not required”. FIG. 12 shows the management table after it has been updated.
[0072] As mentioned above, three values can be applied to the fields indicating the “status of a current snapshot” added to LVOL_TOK and LVOL_TOK_SNAP: “snap creation not required”, “snap creation required”, and “snap created”. The logical volume and snapshot of “snap creation not required” are treated as separate logical volumes.
[0073] Embodiments of the present invention have been explained with reference to the drawings, but the present invention is not limited to these embodiments. In the embodiments described above, hierarchical management was explained between a disk and physical tape. However, the present invention is not limited to this and can be applied to any system that is hierarchically managed using different levels. A similar mechanism can be realized by applying an existing snapshot function to an upper-level disk device and recording the state of data (metadata) which has been moved to a lower-level disk drive as metadata. Snapshot management can be performed using the same technique even when three or more levels are used.
REFERENCE SIGNS LIST
[0000]
1 : Overall system
10 : Storage system
20 : Host, multiple hosts (servers)
30 : Logical volume
40 : Data
50 : Snapshot
101 : 1st storage medium (HDD, etc.)
102 : 2nd storage medium (tape drive, etc.) | The method of the present invention includes the steps of: receiving a command for creating a snapshot of the logical volume; preparing a management table for managing the snapshot; detecting the storage status of the logical volume; and updating the management table without recalling the logical volume from the second level storage to the first level storage when the logical volume has migrated from the first level storage to the second level storage. After the update, the storage table indicates whether creation of a snapshot is required, whether a logical volume has migrated, and whether the second level storage is the storage location of the logical volume. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention concerns a module for measuring purposes according to the main clause of claim 1 .
[0003] 2. Description of the Related Art
[0004] Housings or racks are known from the state of the art into which a limited number of so-called slide-in cards can be inserted. Among those working in this field, these are known by the name 19″-rack or the like.
[0005] Such modularly built slide-in cards, preferably boards carrying an electrical or electronic circuit, usually have one or more power supply connections and one or more data line connections, which are inserted into the plug arrangements located at the back of the corresponding rack, by inserting the slide-in cards into one of the racks described above.
[0006] As a rule, all the plug arrangements provided on the back side of a rack are of similar design and the corresponding contacts of the individual slots are connected together via an electrical connection. In this way, it is achieved that the slide-in cards inserted into the rack are connected together in the manner of a bus.
[0007] Although such systems were found to be useful, an inherent disadvantage is that the rack can hold only a limited number of slide-in cards. Therefore, such a system is not freely scalable, but is always limited by the size of the corresponding rack. In addition, because of this predetermined constructional size, such a system has limited usefulness for the so-called portable measuring technique.
SUMMARY OF THE INVENTION
[0008] Thus, the task of the invention is to provide a system which no longer has the disadvantages mentioned above. Especially, a system should be provided which is freely scalable in any arbitrary manner and is not limited by the size of the rack. In addition, use at almost any arbitrary location should be possible. Finally, it should be useable both for very simple as well as complicated measuring purposes.
[0009] This task is solved by a module for measuring purposes according to the invention having the characteristics of the characterizing part of claim 1 .
[0010] Advantageous embodiments and further developments of the invention are given in the subclaims.
[0011] The essential idea of the invention consists in the fact that the electronic circuit is arranged in a housing which has a first contact surface and a second contact surface. According to the invention, it is provided that the first contact surface can be connected to the second contact surface of another module of like design, so that it can be joined in a manner that permits it to be mechanically detached, that is, it can be in slidingly coupled, interlocked, snapped together or the like. It is provided that at least one power supply connection has a power supply contact in the first contact surface and a corresponding power supply contact in the second contact surface and that the at least one data line connection always has a data line contact in the first contact surface and a corresponding data line contact in the second contact surface. Specifically, this means that the corresponding power supply contacts or data line contacts are in cooperative engagement from the first contact surface to the second contact surface.
[0012] Moreover, it is provided that, in the connected state, that is, when the second contact surface of the additional module is joined to the first contact surface in the manner described above, the power supply contact in the first contact surface be in an electrical connection with the corresponding power supply contact in the second contact surface of the other module and, correspondingly, the data line contact in the first contact surface is an electrical connection with the corresponding data line contact in the second contact surface of the other module.
[0013] Forming connections between the individual modules (corresponding to the slide-in cards in the system according to the state of the art) is done directly by contacting the contacts arranged in the particular housing of the module and not with the aid of additional connections like in the system of the state of the art, which are, for example, components of a rack or optionally are to be produced with the aid of separate cables or lines.
[0014] In this way, it is made possible that, for example, with the aid of a single module, simple measurement tasks can be performed and, depending on the requirements, other modules can be joined together to a larger measuring unit according to the Lego principle. Furthermore, as a result, it is made possible to combine modules from a module assortment for almost any arbitrary measuring tasks. In this way, the measuring system can be assembled and disassembled again rapidly at almost any arbitrary location. Transportation of individual modules is possible as well as transportation of a larger connected total system. Furthermore, the danger of destruction or contamination of the actual electrical or electronic circuits is clearly reduced in comparison to the system according to the state of the art mentioned above.
[0015] A preferred embodiment of the invention provides that the joining of the module with the other module be done with the aid of a bayonet-like lock. The advantage of such a bayonet-like lock consists in the fact that, first of all, joining and separation of the connection can be done rapidly, but on the other hand, it can be done simply. Such bayonet-like lock has been found to be useful in many ways.
[0016] In an especially advantageous variant, it is provided that the first and second contact surfaces be essentially opposing housing surfaces arranged parallel to one another. A measurement unit is obtained by stacking several or a large number of such modules on top of one another. Thus, an especially compact measuring arrangement is obtained.
[0017] Hereby, it is especially advantageous when the first and second contact surfaces are the bottom and covering surfaces, so that the base necessary for the positioning of such a system is not increased by increasing the number of individual modules used.
[0018] An especially advantageous variant provides that the housing be essentially rectangular, a housing form which excels by its low space requirement.
[0019] According to the invention it is provided that, on the first contact surface, at least two guide rails are arranged which run essentially parallel to one another; on the side, which is away from the contact surface, engagement elements in the form of tabs or bars are formed which run essentially parallel to the contact surface, and on the second contact surface guide rails are arranged which are essentially parallel to one another and correspond to the guide rails of the first contact surface; on the side of these, which is away from the contact surface, engagement elements are formed which correspond to the engagement elements of the guide rails of the first contact surface and are essentially parallel to the contact surface, so that the engagement elements can be brought into overlapping contact with the corresponding engagement elements of another module and the modules held together in this way. First of all, an advantage of such an arrangement is that it can be produced with simple means, for example, with the aid of an injection molding method and, on the other hand, it makes it possible to produce safe and rapid connection between the individual modules, which can then be separated again, rapidly and safely. An embodiment of this variation provides that the engagement elements and the corresponding engagement elements are at such a distance that, in order to join the first contact surface to the second contact surface of the other module, the engagement elements can be engaged in the interval of the corresponding engagement elements of the second contact surface of the other module and, vice versa, the corresponding engagement elements of the second contact surface of the other module can be engaged in the interval of the engagement elements and, in this position, by shifting the particular modules against one another, the engagement elements can be joined to the corresponding engagement elements of the other module to form a joint which holds the module together.
[0020] In a further embodiment of this variant or in an individual embodiment independent of this variant of the module according to the invention, it is provided that a rocker lever be supported on a side surface of a rocker bearing arranged on the housing, so that it is tiltable. A lever arm of the rocker lever is supported against the force of a spring on the side surface of the module housing. The other lever arm of the rocking lever has a latch which can be engaged in a groove of the housing of the other module and can be locked with it. Such a rocker lever thus locks two attached modules to one another so they cannot be separated from one another unintentionally.
[0021] The locking and interlocking mechanism of the rocker lever can be realized in a simple manner by the fact that the latch engages in a groove formed from the guide rails and the engagement element. Accordingly, additional measures are not necessary in this variant.
[0022] Furthermore, according to the invention, it is provided that at least one contact of the first contact surface be a contact head with a contact surface inserted into a recess of the first contact surface.
[0023] Corresponding to this, the corresponding contact of the second contact surface is a contact tappet which is arranged so it can be shifted perpendicularly to the contact surface against the force of a spring. In this way, an electrically conducting joint between two attached and optionally locked modules can be produced simply and rapidly. The fact that the contact tappet can be shifted against a spring has the advantage that a reliable electrical contact can be produced even after frequent attachment processes, especially even when the corresponding contact side had been worn due to frequent use, or even contaminated or corroded.
[0024] An especially advantageous variant of the invention provides that, for producing the electrical contact between the contact head and the contact tappet, a spring plate be provided within the housing of a module, one end of which is supported by spring force against a contact tip of the contact head directed toward the inside of the housing and, on the end, it is supported against a contact surface of the contact tappet directed toward the inside of the housing. Such a spring contact has the advantage, first of all, in comparison to a rigid contact that, in the case of shocks, breaking off of the electrical contact is largely avoided and, on the other hand, it has the advantage of simple mounting of a module without time-intensive soldering or attachment processes.
[0025] Furthermore, according to the invention, it is provided that the circuit be arranged on a board and that the spring plate be joined to the board mechanically, rigidly and in an electrically conducting manner. This variation of the embodiment of the invention has the advantage that no additional holder is required for the spring plate, since an attachment in the board within the housing of the module is required anyway. Thus, the board holds the spring plate securely, so that, for example, the cover or bottom plates forming the contact surfaces merely have to be put in place during manufacture or assembly.
[0026] Another variant of the invention provides that the contact tappet be guided so it can be shifted in a guide element. A sealing element is placed into this guide element, surrounding the contact tappet in the manner described above, so that it can be shifted; the inside has a sealing lip surrounding the contact tappet on its periphery for sealing. In this way, entry of water or other fluids inside the housing and destruction of the electrical or electronic circuits or individual electric or electronic circuit elements is prevented.
[0027] Another preferred variation of the embodiment provides that the contact surface of the contact head be enclosed by two bars aligned essentially parallel to the guide rails, extending above the contact surface of the contact head in such a way that touching it by a standardized measuring finger is impossible. Such a design of the invention serves as a safety device against electrostatic discharges.
[0028] In a corresponding manner, it is provided that the contact tip of the contact tappet, designed on the base of a groove formed in the contact surface, running essentially parallel to the guide rail and that the width of the groove be chosen so that touching the contact tip of the contact tappet by a standardized measuring finger is impossible. These two latter variants thus ensure that the electrical or electronic circuits or individual circuit elements, arranged in the module, will not harm the operators due to accumulated electric charge.
[0029] Modules with the following functions are provided:
[0030] a) Measured value recording module
[0031] b) Power supply module
[0032] c) Radio connection module to provide radio connection between measuring systems and measuring units built from one or several modules
[0033] d) Analog-digital converter module or digital-analog converter module
[0034] e) Modules with operating and display functions
[0035] f) Modules with printing functions
[0036] g) Smoke reporting modules
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] A practical example of the invention is shown in the drawing and will be described in more detail below.
[0038] The following are shown:
[0039] [0039]FIG. 1 is a measuring unit consisting of an operating, measuring, display and printing module according to the invention and two measuring modules according to the invention
[0040] perspective view from above—
[0041] [0041]FIG. 2 is a measuring unit consisting of a radio module and two measuring modules according to the invention
[0042] perspective view from above—
[0043] [0043]FIG. 3 is a measuring module according to the invention according to FIG. 1 and FIG. 2
[0044] perspective view from underneath—
[0045] [0045]FIG. 4 is the measuring unit according to FIG. 2, consisting of the radio module according to the invention and two measuring modules according to the invention
[0046] cross-sectional representation along plane A-A—
[0047] [0047]FIG. 5 is the measuring unit according to FIG. 2 and FIG. 4
[0048] detailed view in a longitudinal section along B-B—
[0049] a) Radio module according to the invention and measuring module according to the invention, in the combined but not locked state.
[0050] b) Radio module according to the invention and measuring module according to the invention according to FIG. 5 a ) in the locked state.
[0051] [0051]FIG. 6 is the measuring unit according to FIG. 2 and FIG. 4 with protective device against electrostatic discharges
[0052] detail view Z from FIG. 4—
[0053] [0053]FIG. 7 is the measuring unit according to FIG. 2 and FIG. 4: locking mechanism with the latch of a rocker lever engaged in a guide rail of a measuring module according to the invention
[0054] detail view Y from FIG. 4—
DETAILED DESCRIPTION OF THE INVENTION
[0055] [0055]FIG. 1 shows a measuring unit 1 a consisting of several individual modules 2 , 22 , 32 according to the invention. Specifically, the measuring unit 1 a, shown in FIG. 1, has a combined operating, measuring, display and printing module 2 , a measuring module 22 connected with this and another measuring module 32 connecting to the latter.
[0056] The operating, measuring, display and printing module 2 , as it is obvious from the name, has a keyboard 7 for data input and thus for operation of module 2 , a measuring channel connection 5 to connect it with a measuring cell, a measured value recorder, a sensor or similar. Furthermore, a display 8 is provided in order to display the measured value introduced to measurement channel connection 5 and as well as a small printer 9 , for example, to produce a measuring or data protocol. Furthermore, the operating, measuring, display and printing module 2 has a sending element 3 and a receiving element 4 , through which data communication, for example, via radio, infrared or similar, with another module, can be provided. Finally, the operating measuring display and printing module has a power supply connection 6 on its front side 12 in order to be able to supply module 2 with power from the outside. In the present example, the power supply is provided via a power plug to a conventional low voltage power connection, but it is also conceivable to make module 2 self-sufficient with regard to power or to operate it through an integrated accumulator, batteries or similar.
[0057] The two other measurement modules, 22 and 32 , shown in FIG. 1, have a largely identical form. Both have four measuring channel connections 23 , 24 , 25 and 26 as well as 33 , 34 , 35 and 36 on their front side 12 in front surfaces 94 . These measuring channel connections 23 , 24 , 25 , 26 and 33 , 34 , 35 , 36 , respectively, are designed in the manner of measuring channel connection 5 of the operating, measuring, display and printing module 2 . Thus, they represent merely an extension for the connection of other eight measuring value recorder, sensors or similar.
[0058] According to the invention, it is provided that the operation, parametrization and control of the other measuring channel connections 23 , 24 , 25 and 26 of the measuring module 22 , as well as the measuring channel connections 33 , 34 , 35 and 36 of measuring module 32 occur through the operating, measuring, display and printing module 2 . The evaluation, data acquisition, protocolling, etc., also occurs via the operating, measuring, display and printing module 2 , which, as will be described below, is connected mechanically as well as electrically to the individual modules 22 and 32 .
[0059] In order to demonstrate how such a mechanical and electrical connection between the individual modules according to the invention is realized, FIGS. 2 to 7 show details of the mechanical locking and interlocking mechanism as well as that for producing an electrical connection between the corresponding contact elements necessary for the individual modules.
[0060] [0060]FIG. 2, first of all, shows a measuring unit 1 b according to the invention, consisting of two measurement modules 22 and 32 according to the invention of the type described above, as well as instead of the operating, measuring, display and printing module 2 shown in FIG. 1, it has a radio module 42 according to the invention, namely shown in perspective view from the top onto the top side 10 of radio module 42 . Corresponding to this, FIG. 3 shows, as an example, the measuring module 32 according to the invention according to FIGS. 1 and 2, also in a perspective view from underneath looking at the bottom side 11 .
[0061] The housing of the modules 22 , 32 , 42 has an essentially rectangular shape. Consequently, it consists of six individual surfaces, which are designated below as side surfaces 92 and 93 , front surface 94 , back surface 95 as well as first contact surface 90 and second contact surface 91 . The first and second contact surfaces 90 , 91 are the oppositely arranged base and cover surfaces. The particular front surfaces (and optionally also the back surface 95 ) have, as described above, measuring channel connections 23 , 24 , 25 , 26 or 33 , 34 , 35 , 36 , respectively, as well as sending elements 43 and 44 .
[0062] The first contact surface 90 of a module 22 , 32 , 42 can be locked to the second contact surface 91 of another module 22 , 32 , 42 . The locking mechanism is designed in the example in the manner of a bayonet lock. Specifically, two guide rails 50 and 50 ′, running essentially parallel to one another, are arranged on the first contact surface 90 ; on the side away from contact surface 90 , engagement elements 49 a , 49 b , 49 c , 49 d , 49 a ′, 49 b ′, 49 c ′, 49 d ′ are formed essentially parallel to contact surface 90 . On the second contact surface 79 , guide rails 40 , 40 ′ are arranged, again running parallel to one another, and essentially corresponding to the guide rails 50 , 50 ′ of the first contact surface 90 . On these guide rails 40 , 40 ′, on their side away from contact surface 91 , engagement elements 38 a , 38 b , 38 c , 38 d , 38 a′ , 38 b ′, 38 c ′, 38 d ′ are formed corresponding to the engagement elements 49 a , 49 b , 49 c , 49 d , 49 a ′, 49 b ′, 49 c ′, 49 d ′ of guide rails 50 , 50 ′ of the first contact surface 90 . While in the first case, the engagement elements 49 a , 49 b , 49 c , 49 d , 49 a ′, 49 b ′, 49 c ′, 49 d ′ tend toward the inside against one another, in the second case, the engagement elements 38 a , 38 b , 38 c , 38 d , 38 a′ , 38 b ′, 38 c ′, 38 d ′ run directed toward the outside, so that the engagement elements 49 a , 49 b , 49 c , 49 d , 49 a ′, 49 b ′, 49 c ′, 49 d ′ can be brought into overlapping connection with the corresponding engagement elements 38 a , 38 b , 38 c , 38 d , 38 a′ , 38 b ′, 38 c ′, 38 d ′ of the other module and, in this way, two neighboring modules 42 and 22 or 22 and 32 , respectively, are being held together.
[0063] In the present example, the engagement elements 49 a , 49 b , 49 c , 49 d , 49 a ′, 49 b ′, 49 c ′, 49 d ′ and the corresponding engagement elements 38 a , 38 b , 38 c , 38 d , 38 a′ , 38 b ′, 38 c ′, 38 d ′ are spaced in such a way that, for assembling the first contact surface 90 of a module 22 , 42 with the second contact surface 91 of the neighboring module 32 , 22 , the engagement elements 49 a , 49 b , 49 c , 49 d , 49 a ′, 49 b ′, 49 c ′, 49 d ′ can engage in the intervals 41 a , 41 b , 41 c , 41 a ′, 41 b ′, 41 c ′ of the corresponding engagement elements 38 a , 38 b , 38 c , 38 d , 38 a′ , 38 b ′, 38 c ′, 38 d ′ of the second contact surface 91 of the neighboring module. In an analogous manner, the corresponding engagement elements 38 a , 38 b , 38 c , 38 d , 38 a′ , 38 b ′, 38 c ′, 38 d ′ of the second contact surface 91 of the other module can engage in the intervals 51 a , 51 b , 51 c , 51 a ′, 51 b ′, 51 c ′ of engagement elements 49 a , 49 b , 49 c , 49 d , 49 a ′, 49 b ′, 49 c ′, 49 d ′. The particular modules 22 , 32 , 42 are brought into the fixed position, that is, in the position where the two neighboring modules 42 , 22 or 22 , 32 , respectively, are held together, by being shifted in the position described above, so that the engagement elements 49 a , 49 b , 49 c , 49 d , 49 a ′, 49 b ′, 49 c ′, 49 d ′ engage with the corresponding engagement elements 38 a , 38 b , 38 c , 38 d , 38 a′ , 38 b ′, 38 c ′, 38 d ′ of the neighboring module 22 , 32 , 42 .
[0064] Furthermore, according to the invention, it is provided that two neighboring modules 42 and 22 or 22 and 32 , respectively, can be locked with the aid of a rocker lever 27 , 37 , 47 . The special design according to the invention of such an interlocking mechanism can be seen in detail in FIG. 4, which shows the measurement unit according to FIG. 2, consisting of the radio module 42 according to the invention and two measurement modules 22 and 32 according to the invention in a cross-sectional representation along plane A-A shown in FIG. 2 and in the detail view Y from FIG. 4, which is shown in FIG. 7.
[0065] As can be seen from the drawings, the rocker lever 27 , 37 , 47 is supported tiltably on a rocker bearing 52 arranged on the side surface 92 of the particular housing. A lever arm 48 b of rocker lever 27 , 37 , 47 is supported against the force of a spring 53 on the side surface 92 of the particular housing. In the drawing, the spring 53 is designed in the manner of a spring plate, but a spring, for example, with the aid of a spiral spring or similar, can also be considered.
[0066] The other lever arm 48 a of the rocker lever 27 , 37 , 47 has a latch 54 , which can be engaged in a groove 55 of the housing of the neighboring module and can be locked with it.
[0067] In the present case, the groove is formed by the guide rails 40 and the engagement element 38 b.
[0068] As it was already presented in detail in the introductory part of the Specification, the individual modules 22 , 32 , 42 are joined together in a contacting manner through electrical contact locations which come into contact in the switched state. Especially, in the present case, two power supply contacts 84 a, 85 a are provided, which are arranged in the first contact surface 90 of a module 22 , 32 , 42 and can be brought into contact with the corresponding power supply contact 84 b , 85 b in the second contact surface 91 of the other neighboring module 22 , 32 , 42 . Furthermore, data line contacts 86 a , 87 a are provided in the first contact surface 90 of a module 22 , 32 , 42 , which can be brought into contact with the corresponding data line contacts 86 b, 87 b in the second contact surface 91 of the other neighboring module 22 , 32 , 42 .
[0069] The concrete design of contacts 84 a , 85 a , 86 a , 87 a in the first contact surface 90 and of the corresponding contacts 84 a ′, 85 a ′, 86 a ′, 87 a ′ of the second contact surface 91 can be seen in the drawings according to FIG. 2, FIG. 3, FIG. 4 and FIG. 6. The electrical and mechanical bond between contacts 84 a , 85 a , 86 a and 87 a in the first contact surface 90 and the corresponding contacts 84 a ′, 85 a ′, 86 a ′, 87 a ′ of the second contact surface 91 within a module can be seen especially in FIGS. 4, 5 a and 5 b.
[0070] Specifically, as it can be seen in FIG. 5, the contacts 84 a , 85 a , 86 a , 87 a of the first contact surface 90 always consist of a contact head 70 , which is placed in a recess 75 of the first contact surface 90 , and has a contact surface 72 . The corresponding contacts 84 a ′, 85 a ′, 86 a ′, 87 a ′ of the second contact surface 91 are essentially perpendicular to contact surface 91 against a contact tappet 60 , guided against the force of a spring 81 so that it can be shifted.
[0071] The contact surfaces 72 of the particular contact heads 70 are always enclosed by two bars 76 a and 76 b, aligned essentially parallel to guide rails 50 , 50 ′. These stand above contact surfaces 72 of the particular contact head 70 , so that, especially as can be seen in FIG. 6, touching of it by a standardized measuring finger M is impossible. In the present case, the distance between the tip of the standardized measuring finger M with a tip radius of 4 mm and a contact surface 72 is designated with the aid of reference d 2 .
[0072] In principle, the other contacts 84 b , 85 b , 86 b , 87 b with contact tappet 60 are designed similarly. As shown in FIG. 6, the particular contact tappets 60 are led from the base of grooves 31 a , 31 b , 31 c , 31 d running essentially parallel to the guide rails 40 , 40 ′ and formed in contact surface 91 , where the width of the corresponding grooves 31 a , 31 b , 31 c , 31 d is chosen so that touching the particular contact tips 61 of contact tappet 60 by the standardized measuring finger M with a tip radius of 4 mm is impossible. The distance between the contact tip 61 of a contact tappet 60 and a standardized measuring finger M is shown with reference d 1 in the drawing.
[0073] As can be seen especially from the drawings according to FIG. 4 and FIGS. 5 a and 5 b, the bars 76 a , 76 b, which enclose the contact surfaces 72 of the particular contact heads 70 , are designed specifically so that when sets of two modules 22 , 32 , 42 are joined together, they engage exactly in the particular grooves 31 a , 31 b , 31 c , 31 d from the base of which the particular contact tappets 60 are guided out. The electrical connection is now produced by the fact that, in the shifting process V described above, the corresponding contacts 84 a , 85 a , 86 a , 87 a are brought into connection with the corresponding contacts 84 a ′, 85 a ′, 86 a ′, 87 a ′. In this case, the contact tip 61 of the contact tappet 60 is guided against the force of spring 81 above the recess 75 and the contact head 70 with contact surface 72 placed in it, where the bars 76 a and 76 b serve as guide rails for the contact tip 61 of contact tappet 60 .
[0074] The guidance of the contact tappet 60 so it can be shifted under the action of a spring and the formation of the electrical connection between the particular contacts 84 a , 84 b , 85 a , 86 a , 86 b , 87 a , 87 b within a housing is realized with the aid of a spring plate 81 , as described below. Thus, a spring plate 81 is arranged between the contact head 70 and contact tappet 60 in such a way that, at its one end, it is supported against the contact tip 71 of contact head 70 directed toward the inside of the housing, and on the other end it is supported against contact surface 62 of contact tappet 60 directed inside the housing. A mechanical attachment of the spring plate 81 is realized by the fact that it is connected mechanically, rigidly and electrically conducting to the board 80 carrying the circuit.
[0075] Reference List
[0076] [0076] 1 a measuring unit
[0077] [0077] 1 b measuring unit
[0078] [0078] 2 operating, measuring, display and printing module
[0079] [0079] 3 sending element
[0080] [0080] 4 receiving element
[0081] [0081] 5 measuring channel connection
[0082] [0082] 6 power supply connection
[0083] [0083] 7 keyboard
[0084] [0084] 8 display
[0085] [0085] 9 printer
[0086] [0086] 10 top side
[0087] [0087] 11 bottom side
[0088] [0088] 12 front side
[0089] [0089] 13 back side
[0090] [0090] 22 measuring module
[0091] [0091] 23 measuring channel connection
[0092] [0092] 24 measuring channel connection
[0093] [0093] 25 measuring channel connection
[0094] [0094] 26 measuring channel connection
[0095] [0095] 27 rocker lever
[0096] [0096] 31 a groove
[0097] [0097] 31 b groove
[0098] [0098] 31 c groove
[0099] [0099] 31 d groove
[0100] [0100] 32 measuring module
[0101] [0101] 33 measuring channel connection
[0102] [0102] 34 measuring channel connection
[0103] [0103] 35 measuring channel connection
[0104] [0104] 36 measuring channel connection
[0105] [0105] 37 rocker lever
[0106] [0106] 38 a engagement element
[0107] [0107] 38 b engagement element
[0108] [0108] 38 c engagement element
[0109] [0109] 38 d engagement element
[0110] [0110] 38 a ′ engagement element
[0111] [0111] 38 b ′ engagement element
[0112] [0112] 38 c ′ engagement element
[0113] [0113] 38 d ′ engagement element
[0114] [0114] 40 guide rails
[0115] [0115] 40 ′ guide rails
[0116] [0116] 41 a interval
[0117] [0117] 41 b interval
[0118] [0118] 41 c interval
[0119] [0119] 42 radio module
[0120] [0120] 43 sending element
[0121] [0121] 44 receiving element
[0122] [0122] 47 rocker lever
[0123] [0123] 48 a lever arm
[0124] [0124] 48 b lever arm
[0125] [0125] 49 a engagement element
[0126] [0126] 49 b engagement element
[0127] [0127] 49 c engagement element
[0128] [0128] 49 d engagement element
[0129] [0129] 49 a ′ engagement element
[0130] [0130] 49 b ′ engagement element
[0131] [0131] 49 c ′ engagement element
[0132] [0132] 49 d ′ engagement element
[0133] [0133] 50 guide rails
[0134] [0134] 50 ′ guide rails
[0135] [0135] 51 a interval
[0136] [0136] 51 b interval
[0137] [0137] 51 c interval
[0138] [0138] 52 rocker bearing
[0139] [0139] 53 spring
[0140] [0140] 54 latch
[0141] [0141] 55 groove
[0142] [0142] 60 contact tappet
[0143] [0143] 61 contact tip
[0144] [0144] 62 contact surface
[0145] [0145] 63 sealing element
[0146] [0146] 64 sealing lip
[0147] [0147] 65 guide element
[0148] [0148] 70 contact head
[0149] [0149] 71 contact tip
[0150] [0150] 72 contact surface
[0151] [0151] 75 recess
[0152] [0152] 76 a bar
[0153] [0153] 76 b bar
[0154] [0154] 80 board
[0155] [0155] 81 spring plate
[0156] [0156] 84 a contact
[0157] [0157] 84 b contact
[0158] [0158] 85 a contact
[0159] [0159] 85 b contact
[0160] [0160] 86 a contact
[0161] [0161] 86 b contact
[0162] [0162] 87 a contact
[0163] [0163] 87 b contact
[0164] [0164] 90 first contact surface
[0165] [0165] 91 second contact surface
[0166] [0166] 92 side surface
[0167] [0167] 93 side surface
[0168] [0168] 94 front surface
[0169] [0169] 95 back surface
[0170] V shifting direction
[0171] d 1 distance
[0172] d 2 distance
[0173] M standardized measuring finger | The invention relates to a module for measuring purposes comprising an electrical or electronic circuit, which has at least one power supply connection and at least one data line connection for connecting, in the manner of a bus, to at least one other module of the same type that is also used for measuring purposes. According to the invention, the electronic circuit ( 80 ) is arranged inside a housing, the housing has a first contact surface ( 90 ) and a second contact surface ( 91 ), and the first contact surface ( 90 ) is joined to the second contact surface ( 91 ) of the other module ( 22, 32, 42 ) in a manner that permits it to be mechanically detached. The at least one power supply connection has a power supply contact ( 84 a, 85 a ) in the first contact surface ( 90 ) and has a corresponding power supply contact ( 84 b, 85 b ) in the second contact surface ( 91 ). The at least one data line connection has a data line contact ( 86 a, 85 a ) in the first contact surface ( 90 ) is connected in an electrically conductive manner to the corresponding power supply contact ( 84 b, 85 b ) in the second contact surface ( 91 ) of the other module ( 22, 32, 42 ), and the data line contact ( 86 a, 87 a ) in the first contact surface ( 91 ) of the other module ( 22, 32, 42 ). | 8 |
This is a division of application Ser. No. 183,857, filed Sept. 3, 1980 now abandoned.
BACKGROUND OF THE INVENTION
Curable resins have long been used to insulate metallic conductors. Representative is their use as magnet wire enamels--see, for example, U.S. Pat. Nos. 2,936,296; 3,342,780; U.K. Pat. No. 973,377; U.S. Pat. No. 3,426,098; and U.S. Pat. No. 3,668,175.
Such enamels most commonly comprise a solution of the resin in a solvent therefor. This solution may be applied to the conductor, dried and subjected to conventional curing conditions. This results in the production of a solid coating or wall of insulating resin peripherally about the conductor.
Myriad resins or combinations of resins have been employed in such enamels. Polyester resins, particularly ones produced through condensation of glycols and polyfunctional acids or anhydrides, have long been utilized in this manner. See, e.g., U.S. Pat. No. 2,936,296.
In U.S. Pat. No. 3,541,038, the production of high molecular weight polyimidamide resins by condensation of tribasic acid anhydride with diisocyanate compounds is described. The resultant resins are especially useful for coil-impregnation or electrical insulation. Tough films can also be produced from solutions of them.
More recently, polyetherimides comprising the reaction products of bis ether anhydrides with organic diamines have been suggested for use as wire coatings. They can be deposited on the conductor from simple solvents, U.S. Pat. No. 3,847,867; or as powders from fluidized beds, U.S. Pat. No. 4,098,800; or from reactive ether solvents, U.S. Pat. No. 4,115,341; or as reaction products prepared in the presence of a phenolic solvent, U.S. Pat. No. 4,024,010.
Polyisocyanate compounds, preferably employed in blocked form, are also described in U.S. patent application Ser. No. 53,317 where they are reacted to cross-link various polyetherimides. The resultant resins make highly preferred enamels for electrical insulation.
It is also known to upgrade the properties of such wire enamels by including minor proportions of other additives. For example, U.S. Pat. No. 3,668,175 confirms that the addition of titanate esters, phenolic resins, and the like, have exemplary effects on such important properties of wire enamels as flexibility, abrasion resistance, heat shock, cut-through temperature, and thermal life. This patent also discloses a general improvement in heat shock, at some expense to thermal life, when adding blocked polyisocyanates to enamels comprising polyester amide imides.
Notwithstanding the foregoing and other improvements in the properties of enamels, drawbacks respecting their application have remained. Most importantly, enamels applied from solvent solution commonly produce rough and grainy coatings. Such coating walls are inefficient as insulators and result in substantial scrap losses.
DESCRIPTION OF THE INVENTION
The present invention involves a means for producing smooth insulation surfaces on electrical conductors. This avoids the previously described drawbacks and is accomplished by improving the surface coatability of an enamel solution.
This improved coatability is obtained by incorporating nylon polymer within the enamel solution. An effective amount of the nylon enhances its surface coatability. This results in production of a smooth and non-grainy wall or coating of insulating resin on a treated conductor.
Enamel compositions susceptible to improvement in accordance with present invention include any of the well known and/or available resin solutions. These compositions may be quite simple and need comprise only a curable resin and a solvent therefore. Ordinarily, the resin is present in from 15 to 60% by weight of solvent.
As described above, many suitable resins are known and there is no criticality in their selection. Preferred, however, are the previously mentioned polyester, polyesterimide and/or polyetherimide resins, particularly ones cross-linked with polyfunctional isocyanate agent or the like.
The solvent likewise lacks criticality. Any solvent or mixture of solvents which will dissolve the particular resin utilized is satisfactory. Representative are such preferably organic solvents as cresylic acids, phenols and aprotic solvents and glycol ethers.
Any nylon--i.e., polyamide--may be utilized in accordance with the present invention. Representative are Dupont's Elvamid 8061.
While the amount of nylon incorporated into the enamel may vary greatly, it must be an amount sufficient to enhance surface coatability. The amount of nylon polymer and curable enamel resin are preferably in a weight ratio of from 2:25 to 0.5:25.
In addition to these essential ingredients, the present compositions may contain such common enamel additives as resin curing and/or cross-linking agents, etc. It may also contain conventional nylon adjuncts, including delustrants, such as titanium compounds.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE shows a cross-sectional view of an insulated conductor of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS AND EXAMPLES
In the FIGURE, a magnet wire 10, has a conductor 11 (normally metallic) covered peripherally with an insulating wall or layer 12 of curable resin admixed with nylon polymer. Although the FIGURE illustrates a conductor wire which is circular in cross-section, it will be understood that square, rectangularly or other shaped conductors in, for example, the form of flat strips or foils may also be used without departing from the scope of this invention.
Wire test properties are carried out by standard tests. "Flexibility 25+" is done by elongating a specimen, winding it ten times around a mandrel and examining for adherence failure, and the values are expressed in units comprising mandrel diameters (Reference GE Method E18B4 and National Electrical Manufacturers Association (NEMA) Pub. No. MW1000 Part 3, Paragraph 2.1.1). Dissipation factor is done by immersing a bent section of coated wire in hot mercury and measuring at 60 to 1000 hertz by means of a General Radio Bridge, or its equivalent, connected to the specimen and the mercury. The values are expressed in units of % at the specified temperature in degrees Centrigrade (Reference NEMA 9.1.1). Heat aging is carried out by placing a coil of unstretched unbent coated wire in an oven under the specified conditions and evaluating it after 21 hours. The values are expressed in mandrel diameters withstanding failure after 21 hours, at 175.C., and 0% stretch. Cut through temperature is done by positioning two lengths of wire at right angles, loading one with a weight and raising the temperature until thermoplastic flow causes an electrical short, and the values are expressed in units comprising degrees centrigrade at 2000 g. (Reference NEMA method 50.1.1). Dielectric strength is determined on twisted specimens to which are applied 60-hertz voltage until breakdown occurs. The breakdown voltage is measured with a meter calibrated in root-mean-square volts. The values are expressed in units comprising kilovolts (kv). (Reference NEMA Method 7.1.1)
EXAMPLE I
A flask equipped with a thermometer, N 2 purge, mixer, and packed column with Dean Stark trap, is charged with following:
______________________________________Material Grams______________________________________Ethylene glycol 214.0Terephthalic acid 582.0Trimellitic anhydride 574.0Methylene Dianiline 298.0Tris-2-hydroxyethylisocyanurate 820.0Tetra isopropyl titanate 4.6Monethyl ether diethylene glycol 422.0Nylon (Elvamide 8061 of duPont) 91.0______________________________________
The contents are heated to a maximum of 218° C. until the theoretical amount of water is obtained and the acid number reaches 0.51%. Then with cooling, 1350 grams of monethyl ether diethylene glycol and 442 grams of Solvesso 100 are added. To 1500 grams of the above, 52.68 grams of a blocked tri-functional isocyanurate (Mondur SH) and 21 grams of tetra isopropy titanate are added.
A metal wire is coated with the resultant enamel utilizing seven passes on a 15 foot gas-fired down-draft tower. The surface of the coated insulation is smooth. In contrast, wire coated in the same manner and utilizing the same enamel formula (except for the omission of the nylon) has a poor and grainy appearance.
EXAMPLE II
The process of Example I is repeated except the flask contents are heated to a maximum of 217° C. until the theoretical amount of water was obtained and the acid reaches 0.6%. Then, with cooling, 1200 grams of monoethyl ether diethylene glycol and 442 grams of Solvesso 100 are added. To 1500 grams of the above, 52.68 grams of a blocked isocyanurate (Mondur SH) and 21 grams of tetra isopropyl titanate are added.
After application as in Example I, the coated enamel has the following properties:
______________________________________Film smoothness SmoothFlexibility 25+ 2XDissipation factor 220° C. 4.9Heat aging, 21 hrs. 175° C.-0% 1XCut through, °C. 405Dielectric strength, kV 9.5______________________________________
EXAMPLE III
The process of Example II is repeated except 112 grams of 50% phenolic resin is added to the enamel immediately prior to application to the wire. After application, the coated enamel has the following properties:
______________________________________Film smoothness ExcellentFlexibility 25+ 1Dissipation factor 220° C. 4.8Heat aging, 21 hrs., 175° C.-0% 2XCut through, °C. 400Dielectric strength, kV 9.2______________________________________
To more completely describe the present invention, the disclosures of the various applications and patents mentioned above are incorporated herein by reference. Obviously, many modifications and variations of the present invention are possible in the light of the above and other well-known teachings. It is therefore to be understood that changes may be made in the particularly described embodiments of this invention. All are within the full intended scope of the invention as defined in the appended claims. | Improved enamels and insulated electrical articles produced therefrom are described. The enamels are composed of solutions of curable resin which have been modified to contain nylon polymer. This polymer facilitates application of the enamel to a metallic conductor so as to produce an especially smooth and desirable insulation coating. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to chilled water systems that include variable flow pumps for circulating the chilled water through multiple chillers. More specifically, the present invention relates to a method of controlling such a system.
[0003] 2. Description of Related Art
[0004] A chiller is an assembly of refrigerant components arranged in a circuit for cooling water. The chilled water is typically pumped to a number of remote heat exchangers or system coils for cooling various rooms or areas within a building.
[0005] In some cases, the water may be cooled by a chiller system comprising two or more chillers. When the cooling demand is low, only one chiller of the system may need to operate, and the operating chiller's capacity may be controlled to match the demand. The cooling demand is often determined by sensing the temperature of the chilled water discharged from the chiller system and comparing the sensed temperature to a predetermined target temperature. If the cooling demand is beyond a single chiller's maximum capacity, one or more additional chillers may need to be energized. Then, the operating chillers are controlled so the system's total capacity (sum of the chillers' individual capacities) meets the cooling demand.
[0006] Meanwhile, the chilled water is pumped at a flow rate that is adequate for each individual chiller and is delivered at a pressure sufficient to meet the needs of the system coils. This can be accomplished by pumping the chilled water with variable speed pumps and/or controlling a bypass valve to convey a portion of the discharged chilled water back to the suction side of the pumps.
[0007] Overall, controlling a chiller system can become quite involved. This is due to the difficulty of coordinating the control of several diverse chiller components, such as multiple chillers of varying capacity, multiple variable speed pumps, and a bypass valve. Moreover, the system components must operate to satisfy various needs, such as meeting the cooling demand, providing sufficient water pressure for the system coils, and providing adequate water flow through the chillers. A need to minimize the power consumption of the chillers and the chilled water pumps further complicates the controls of chiller systems. Although controls of such systems do exist, their actual control schemes may limit their use or effectiveness in certain applications, and their complexity may make them difficult to understand, install and service. Since many chiller installations have unique system requirements, there is a need for a more adaptable, straightforward control scheme for controlling chiller systems with variable speed chilled water pumps.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to coordinate the operation of multiple chillers, multiple variable speed pumps, and a bypass valve to meet a cooling demand.
[0009] Another object of some embodiments of the invention is to energize a second chiller in response to a cooling demand exceeding that what can be met by a first chiller, and de-energizing the second chiller upon the cooling demand decreasing to a level below the first chiller's maximum capacity.
[0010] Another object of some embodiments is to operate two chillers in unison, whereby the chillers operate at the same capacity with respect to a percentage of their maximum capacity.
[0011] Another object of some embodiments is to operate two pumps at the same speed, but vary their speed to achieve a certain discharge pressure or pressure differential.
[0012] Another object, for a chiller system having two variable speed water pumps, is to maintain sufficient water flow through two chillers by opening a bypass valve that is in parallel flow relationship with the chillers.
[0013] Another object of some embodiments is to vary the speed of two pumps in response to sensing a pressure differential across a remote heat exchanger coil.
[0014] One or more of these objects are provided by a chiller system that includes two variable speed pumps that pump water through a first chiller and a second chiller for cooling the water. A control energizes the second chiller in response to a cooling demand exceeding that what can be met by the first chiller operating alone, and de-energizes the second chiller upon the cooling demand decreasing to a level below the first chiller's maximum capacity.
[0015] The present invention provides a method of controlling a chiller system that includes a first chiller and a second chiller through which water can be pumped to meet a cooling demand. The method comprises: pumping the water through the first chiller at a first flow rate to meet the cooling demand; increasing the cooling demand; in response to increasing the cooling demand, pumping the water through the first chiller at a second flow rate that is less than the first flow rate; and in response to increasing the cooling demand, pumping the water through the second chiller at a third flow rate, wherein the first flow rate is substantially equal to a sum of the second flow rate plus the third flow rate. The present invention also provides, with respect to the water, piping the first chiller and the second chiller in parallel flow relationship with a heat exchanger that is spaced apart from the first chiller and the second chiller, whereby the water is conveyed to the heat exchanger via a supply line and is conveyed from the heat exchanger via a return line; sensing a water pressure differential between the supply line and the return line; and controlling the first flow rate, the second flow rate and the third flow rate in response to sensing the water pressure differential.
[0016] The present invention further provides a method of controlling a chiller system that includes a first chiller and a second chiller for meeting a demand for chilled water, wherein the first chiller is selectively operable at a first full load and a first range of partial loads, and the second chiller is selectively operable at a second full load and a second range of partial loads. The chiller system further includes a chilled water circuit, a first pump for forcing the chilled water through the first chiller at a first flow rate that may vary, a second pump for forcing the chilled water through the second chiller at a second flow rate that may vary, a bypass valve, a first heat exchanger, and a second heat exchanger. The chilled water circuit connects the first chiller, the second chiller, the bypass valve, the first heat exchanger, and the second heat exchanger in parallel flow relationship with respect to the flow of chilled water. The method comprises increasing the demand for chilled water; in response to increasing the demand for chilled water, changing the operation of the first chiller from operating at the first full load to operating within the first range of partial loads; in response to increasing the demand for chilled water, reducing the first rate at which the first pump forces chilled water through the first chiller; and in response to increasing the demand for chilled water, energizing the second chiller to begin operating the second chiller in the second range of partial loads. The present invention yet further provides, via a supply line of the chilled water circuit, conveying the chilled water to the first heat exchanger and the second heat exchanger; via a return line of the chilled water circuit, conveying the chilled water from the first heat exchanger and the second heat exchanger; sensing a water pressure differential between the supply line and the return line; and varying the first flow rate and the second flow rate in response to sensing the water pressure differential.
[0017] The present invention still further provides a method of controlling a chiller system that includes a first chiller and a second chiller for meeting a demand for chilled water. The first chiller is selectively operable at a first full load and a first range of partial loads, and the second chiller is selectively operable at a second full load and a second range of partial loads. The chiller system further includes a chilled water circuit, a first pump for forcing the chilled water through the first chiller at a first flow rate that may vary, a second pump for forcing the chilled water through the second chiller at a second flow rate that may vary, a bypass valve, a first heat exchanger, and a second heat exchanger. The chilled water circuit connects the first chiller, the second chiller, the bypass valve, the first heat exchanger, and the second heat exchanger in parallel flow relationship with respect to the flow of chilled water. The method comprises establishing a chilled water temperature target; establishing a chilled water pressure target; selectively operating the chiller system in a high demand mode and a low demand mode to meet the chilled water temperature target; in the low demand mode, leaving the second chiller inactive while selectively operating the first chiller in the full load and the first range of partial loads to meet the chilled water temperature target; in the low demand mode, leaving the second pump inactive while modulating the pressure of the chilled water by controlling the operation of the first pump to meet the chilled water pressure target; in the high demand mode, operating the first chiller at a first partial load while operating the second chiller at a second partial load; and in the high demand mode, modulating the pressure of the chilled water by controlling the operation of the first pump and the second pump to meet the chilled water pressure target.
[0018] The present invention additionally provides a method of controlling a chiller system that includes a first chiller and a second chiller for meeting a demand for chilled water. The first chiller is selectively operable at a first full load and a percent of the first full load ranging from zero to one hundred percent, and the second chiller is selectively operable at a second full load and a percent of the second full load ranging from zero to one hundred percent. The chiller system further includes a chilled water circuit, a first pump for forcing the chilled water through the first chiller at a first flow rate that may vary, a second pump for forcing the chilled water through the second chiller at a second flow rate that may vary, a bypass valve, a first heat exchanger, and a second heat exchanger. The chilled water circuit connects the first chiller, the second chiller, the bypass valve, the first heat exchanger, and the second heat exchanger in parallel flow relationship with respect to the flow of chilled water. The method comprises establishing a chilled water temperature target; establishing a chilled water pressure target; selectively operating the chiller system in a high demand mode and a low demand mode to meet the chilled water temperature target; in the low demand mode, leaving the second chiller inactive while operating the first chiller to meet the chilled water temperature target; in the low demand mode, leaving the second pump inactive while modulating the pressure of the chilled water by controlling the operation of the first pump to meet the chilled water pressure target; in the low demand mode, modulating the pressure of the chilled water by controlling the operation of the first pump and the second pump to meet the chilled water pressure target; in the high demand mode, modulating the first chiller at a percentage of the first full load; and in the high demand mode, modulating the second chiller at a percentage of the second full load and in unison with the first chiller, whereby the percentage of the first full load is substantially equal to the percentage of the second full load.
[0019] The present invention moreover provides a chiller system. The system comprises a first chiller wherein the first chiller is selectively operable at a first full load and a first range of partial loads; and a second chiller for meeting a demand for chilled water wherein the second chiller is selectively operable at a second full load and a second range of partial loads. The system also comprises a first pump for forcing the chilled water through the first chiller at a first flow rate that may vary, a second pump for forcing the chilled water through the second chiller at a second flow rate that may vary; a bypass valve; a first heat exchanger; a second heat exchanger; and a chilled water circuit. The chilled water circuit connects the first chiller, the second chiller, the bypass valve, the first heat exchanger, and the second heat exchanger in parallel flow relationship with respect to the flow of chilled water; control circuitry or logic establishing a chilled water temperature target; control circuitry or logic establishing a chilled water pressure target; control circuitry or logic selectively operating the chiller system in a high demand mode and a low demand mode to meet the chilled water temperature target. The system further comprises, in the low demand mode, leaving the second chiller inactive while selectively operating the first chiller in the full load and the first range of partial loads to meet the chilled water temperature target; control circuitry or logic, in the low demand mode, leaving the second pump inactive while modulating the pressure of the chilled water by controlling the operation of the first pump to meet the chilled water pressure target; control circuitry or logic, in the high demand mode, operating the first chiller at a first partial load while operating the second chiller at a second partial load; and control circuitry or logic, in the high demand mode, modulating the pressure of the chilled water by controlling the operation of the first pump and the second pump to meet the chilled water pressure target.
[0020] The present invention still further provides a chiller system. The system includes a first chiller where the first chiller is selectively operable at a first full load and a percent of the first full load ranging from zero to one hundred percent; a second chiller for meeting a demand for chilled water where the second chiller is selectively operable at a second full load and a percent of the second full load ranging from zero to one hundred percent; a first pump for forcing the chilled water through the first chiller at a first flow rate that may vary; and a second pump for forcing the chilled water through the second chiller at a second flow rate that may vary. The system also includes a bypass valve; a first heat exchanger; a second heat exchanger; and a chilled water circuit wherein the chilled water circuit connects the first chiller, the second chiller, the bypass valve, the first heat exchanger, and the second heat exchanger in parallel flow relationship with respect to the flow of chilled water. The system also includes a controller establishing a chilled water temperature target and a chilled water pressure target, the controller selectively operating the chiller system in a high demand mode and a low demand mode to meet the chilled water temperature target. In the low demand mode, the controller leaves the second chiller inactive while operating the first chiller to meet the chilled water temperature target; in the low demand mode, the controller leaves the second pump inactive while modulating the pressure of the chilled water by controlling the operation of the first pump to meet the chilled water pressure target; in the low demand mode, the controller modulates the pressure of the chilled water by controlling the operation of the first pump and the second pump to meet the chilled water pressure target; in the high demand mode, the controller modulates the first chiller at a percentage of the first full load; and in the high demand mode, the controller modulates the second chiller at a percentage of the second full load and in unison with the first chiller. The percentage of the first full load is substantially equal to the percentage of the second full load.
DESCRIPTION OF THE DRAWING FIGURES
[0021] [0021]FIG. 1 is a schematic diagram of a chiller system according to one embodiment of the invention.
[0022] [0022]FIG. 2 is a flow chart illustrating a control scheme for the chiller system of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] A chiller system 10 , shown in FIG. 1, includes multiple chillers for generating chilled water. The term, “chiller” refers to any apparatus having a refrigerant cycle for creating a cooling effect. Multiple pumps force the water through the chillers, and a chilled water circuit 12 distributes the chilled water to various system coils or heat exchangers for cooling rooms or other areas within a building. Although system 10 may include any number of chillers and pumps, for illustration, system 10 will be described as having two chillers 14 and 16 , two pumps 18 and 20 , and two coils 22 and 24 .
[0024] Chillers 14 and 16 are schematically illustrated to represent all types of chillers. In one embodiment of the invention, chiller 14 includes a compressor 26 that forces a refrigerant in series through a condenser 28 , an expansion device 30 (e.g., flow restrictor, orifice, capillary, expansion valve, etc.), and an evaporator 32 . With the aid of a condenser fan 34 (or some other system for promoting the transfer of heat), condenser 28 releases waste heat from relatively hot compressed refrigerant inside condenser 28 . From condenser 28 , the refrigerant expands and its temperature drops upon passing through expansion device 30 . The cooler refrigerant then passes through evaporator 32 to cool the water that pump 18 forces through evaporator 32 . After cooling the water, the refrigerant returns to the suction side of compressor 26 to perpetuate the refrigerant cycle.
[0025] Chiller 14 is preferably provided with a device that can adjust the refrigerant's flow rate for varying the chiller's capacity or cooling effect. Common examples of such a device include, but are not limited to, adjustable inlet guide vanes of a centrifugal compressor, a slide valve of a screw compressor, and a compressor driven by a variable speed motor. All of these examples and more are schematically represented by arrow 36 .
[0026] In some embodiments of the invention, chillers 14 and 16 are similar in that chiller 16 includes a compressor 26 ′, a condenser 28 ′, an expansion device 30 ′ and an evaporator 32 ′. However, one chiller may have a higher maximum cooling capacity than the other.
[0027] Chillers 14 and 16 may be installed in the same general location (e.g., basement or roof of the building), and system coils 22 and 24 may be installed where they are closer to the areas they cool. To connect the chillers to the coils, chilled water circuit 12 includes a supply line 38 and a return line 40 . Supply line 38 conveys chilled water from chillers 14 and 16 to coils 22 and 24 . From supply line 38 , the chilled water passes through coils 22 and 24 to cool air that a fan forces across the coils to cool the building. Valves 42 and 44 can throttle the flow of chilled water to a coil, thereby providing a way to individually control or limit the amount of cooling for a particular area of the building. After the water passes through the coils, the return line 40 conveys the water back to the inlet side of pumps 18 and 20 .
[0028] To inhibit backflow through the chillers, circuit 12 may include two check valves 46 and 48 . When only one chiller/pump is operating, one of the check valves prevents the water from flowing backwards through the inactive chiller/pump. For example, if chiller 14 and pump 18 are operating while chiller 16 and pump 20 are inactive, check valve 48 prevents water in supply line 38 from flowing backwards in series through evaporator 32 ′, pump 20 and into return line 40 . Likewise, check valve 46 prevents water from flowing backwards through evaporator 32 when pump 20 is operating and pump 18 is inactive.
[0029] In some situations, such as during periods of very low cooling demand, valves 42 and 44 may throttle the water flow to such an extent that the total flow rate is inadequate for chiller 14 or 16 . If the flow rate through an operating chiller becomes too low, the water might freeze inside the chiller. To avoid this, a bypass valve 50 may be partially or fully opened to create a shunt that can convey at least a portion of the water from supply line 38 directly to return line 40 without all the water having to first pass though valves 42 and 44 .
[0030] To provide chilled water at a proper temperature and pressure, system 10 includes a controller 52 . Controller 52 is schematically illustrated to encompass a wide variety of electrical devices (programmable or not programmable) having the ability to provide various output signals 54 in response to various input signals 56 . Examples of controller 52 include, but are not limited to, microcomputers, personal computers, dedicated electrical circuits having analog and/or digital components, programmable logic controllers, and various combinations thereof.
[0031] In some embodiments of the invention, controller 52 controls chiller system 10 according to the flow chart of FIG. 2. In decision block 58 , controller 52 compares the actual chilled water temperature to an established chilled water temperature target or set point. Controller 52 can determine the actual chilled water temperature from a temperature sensor 60 on supply line 38 and/or individual temperature sensors 62 and 64 (associated with chillers 14 and 16 , respectively). Controller 52 may receive temperature-indicating signals 66 , 68 and 70 from temperature sensors 60 , 62 and 64 , respectively. Establishing the chilled water temperature target can be performed through a conventional input device, such as a keyboard, dial, etc.
[0032] If block 58 determines that the actual chilled water temperature is less than or equal to the set point, control decision block 70 determines whether chiller 14 should continue operating (provided it was already operating). If chiller 14 is operating below its predetermined minimum capacity, control block 72 deactivates chiller 14 , and control returns to decision block 58 . Otherwise, control shifts to control block 74 , which compares an actual chilled water pressure to an established chilled water pressure target.
[0033] Establishing the chilled water pressure target can be a performed at any time before or after the installation of system 10 and may be performed through a conventional input device, such as a keyboard, dial, etc. Controller 52 can determine the actual chilled water pressure from a pressure sensor 76 (sensing pressure of water entering chiller 14 ), a pressure sensor 78 (sensing pressure of water entering chiller 16 ), a pressure sensor 80 (sensing the pressure of water leaving chiller 14 ), a pressure sensor 82 (sensing the pressure of water leaving chiller 16 ), a pressure sensor 84 (sensing the pressure of water in supply line 38 , near coil 24 ), and/or a pressure sensor 86 (sensing the pressure of water in return line 40 , near coil 24 ). The actual chilled water pressure value can be a single pressure reading or a pressure differential between two pressure readings. Controller 52 may receive pressure-indicating signals 88 , 90 , 92 , 94 , 96 and 98 from pressure sensors 76 , 78 , 80 , 82 , 84 and 86 , respectively.
[0034] In a currently preferred embodiment, block 74 compares the chilled water pressure target (e.g., a delta-P value) to a pressure differential (signal 96 minus signal 98 ) across the system coil (e.g., coil 24 ) that is furthest from the chillers. In response to the comparison in block 74 , block 100 directs controller 52 to provide an output signal 102 that causes pump 18 to create a pressure differential across coil 24 that meets the target value. Controlling a pump to modulate pressure is well known to those skilled in the art. For example, pump 18 can be driven by a variable speed motor whose inverter or other control circuitry is responsive to signal 102 .
[0035] In block 104 , control 52 varies the opening of bypass valve 50 via a signal 105 if the water flow through chiller 14 is too low. Controller 52 can determine the flow rate by receiving a flow rate input signal 106 from a flow sensor 108 . Alternatively, the flow rate can be determined by comparing known flow characteristics of evaporator 32 to the pressure drop across the evaporator (the difference between pressure signals 92 and 88 ).
[0036] In block 110 , controller 52 provides one or more output signals 112 that vary the capacity or otherwise control chiller 14 in an attempt to meet the cooling demand with chiller 16 inactive. With only one chiller operating, system 10 is considered as operating in a low demand mode. Controller 52 generates output signal 112 in response to the chilled water temperature signal 66 , chilled water temperature signal 62 , and/or signal 114 , wherein signal 114 represents various common feedback from the operation of chiller 14 . In this example, output signal 112 represents one or more signals for varying the opening of inlet guide vanes and varying the speed of compressor 26 , thereby operating chiller 14 over a range of partial loads between zero and one hundred percent of the chiller's full load. Such control of a single chiller to meet a cooling demand can be accomplished by any of the numerous control functions well known to those skilled in the art.
[0037] Periodically, decision block 116 determines whether chiller 14 is operating at its rated full load. If not, control of system 10 continues as just described. However, if chiller 14 is at full load, another decision block 118 determines whether chiller 14 is able to maintain the chilled water temperature at or below its target temperature. If chiller 14 operating at full load is sufficient to meet the cooling demand, control returns to block 58 whose function has already been defined.
[0038] Referring back to block 118 , if chiller 14 is unable to meet the cooling demand, control shifts to block 120 to change the operation of system 10 to a high demand mode. In the high demand mode, block 120 directs controller 52 to provide an output signal 122 that activates pump 20 . Controller 52 now modulates both pumps 18 and 20 to create a pressure differential across coil 24 that meets the water pressure target. Upon switching from the low demand mode to the high demand mode, signal 102 will reduce the speed of pump 18 , since two pumps are now running instead of just one. Ideally, the flow rate through pump 18 operating alone during the low demand mode will be about equal to the combined flow rates through pumps 18 and 20 during the high demand mode. In the high demand mode, the speed modulation of both pumps can be simplified by controlling their speed in unison, whereby both pumps are controlled to run at the same speed or at the same percentage of their rated full speed.
[0039] In block 124 , controller 52 varies the opening of bypass valve 50 if the water flow through either chiller 14 or 16 is too low. Similar to what was done with chiller 14 , controller 52 can determine the flow rate through evaporator 32 ′ by receiving a flow rate input signal 126 from a flow sensor 128 . Alternatively, the flow rate through chiller 16 can be determined by comparing known flow characteristics of evaporator 32 ′ to the pressure drop across the evaporator (the difference between pressure signals 94 and 90 ).
[0040] In block 130 , controller 52 provides output signals 112 and 112 ′ to vary the capacity or otherwise control chillers 14 and 16 , respectively. With both chillers operating, system 10 is considered as operating in the high demand mode for meeting generally higher cooling demands. Controller 52 generates output signals 112 and 112 ′ in response to one or more feedback signals, such as chiller water temperature signals 66 , 68 and 70 and/or signals 114 and 114 ′. Signals 114 and 114 ′ are similar in that they both represent various common feedbacks from the operation of their respective chiller. In this example, output signal 112 ′ represents one or more signals for varying the opening of inlet guide vanes and varying the speed of compressor 26 ′, thereby operating chiller 16 over a range of partial loads between zero and one hundred percent of the chiller's full load. In the high demand mode, the capacity of chillers 14 and 16 are preferably modulated in unison, whereby both chillers operate at the same percentage of their respective full load rating. For example, at times, both chillers operate at 50% of their full load, and other times they both chillers operate at 75% of their full load. This can be done even when one chiller has a significantly higher full load capacity than the other.
[0041] Periodically, a decision block 132 determines whether system 10 can return to operating in the low demand mode. This is done by considering the combined partial loads of both chillers 14 and 16 and comparing that to the rated full load of chiller 14 . If the rated full load of chiller 14 is appreciably greater than the combined partial loads of both chillers, control block 134 will deactivate chiller 16 , and block 136 will stop pump 20 , thereby returning system 10 to its low demand mode of operation. Otherwise, control returns to block 120 , and system 10 continues operating in the high demand mode.
[0042] When a chiller is operating at less than full load, the chiller's partial load can be determined in various ways that are well known to those skilled in the art. For example, the electrical current to the motor that drives the compressor can be measured (e.g., signal 114 or 114 ′), and the chiller's percent of full load can be approximated as a ratio of the motor's current draw at part load to the motor's current draw at full load. Alternatively, a chiller's load can be defined as a product of the flow rate of chilled water passing through the chiller's evaporator (e.g., signal 106 or 126 ) times the chilled water's temperature drop upon passing through the evaporator. Such a temperature drop can be determined by installing temperature sensors 150 and 152 , which provide signals 138 and 140 that indicate the temperature of the water entering evaporators 32 and 32 ′ respectively. The temperature drop will then be the value of signal 68 minus the value of signal 138 for evaporator 32 , or the value of signal 70 minus the value of signal 140 for evaporator 32 ′. Sensing the position of a compressor's inlet guide vanes, the position of a compressor's slide valve, and/or a compressor's speed are other ways of determining a chiller's operating load.
[0043] Although the invention is described with reference to a preferred embodiment, it should be appreciated by those skilled in the art that other variations are well within the scope of the invention. Therefore, the scope of the invention is to be determined by reference to the claims, which follow. | To provide chilled water, a variable-primary-flow system includes two variable speed pumps that pump water through a first chiller and a second chiller. A control energizes the second chiller in response to a cooling demand exceeding that what can be met by the first chiller operating alone, and de-energizes the second chiller upon the cooling demand decreasing to a level below the first chiller's maximum capacity. When both chillers are operating, the capacities of the chillers are modulated in unison to meet the cooling demand. Likewise, when both pumps are running, their speed is modulated in unison to provide a desired pressure. | 5 |
BACKGROUND OF THE INVENTION
This invention relates generally to de-mountable sunshade canopy structures and in particular sunshade canopies for ultraviolet (UV) sun ray protection of childrens' play areas.
It is increasingly acknowledged that physically challenging outdoor play structures are of benefit to the physical and emotional development of young children. A code of safety specifications for the construction and maintenance of childrens' play structures has been developed by National Play and Playground Authorities, published (1996) by the National Recreation and Park Association Arlington, Va. These construction specifications describe construction features for support of childrens' slides, swings, climbing apparatus, etc. which minimize risk of injury to children engaged in all manner of predictable use and misuse of the play structures.
The specifications require that the play structures be mounted on a platform or on towers elevated up to six feet above a resilient (non-hardened) surface such as cork or rubber panels, and the towers or platform be supported by a very limited number of support columns. The columns are to be capped at the top and without exterior fittings on which a child could be caught or injured while climbing upon or falling from the platform or tower. The support columns are capped at the top to discourage a child from climbing or holding on suspended from the column top. The vertical support columns have been in the past a source of injures to children engaged in unintended use of these structures. Accordingly, the minimum number of vertical support columns, all free of hand or foot holds, has become a specification for acceptable safe design.
Separate from the safe construction design specifications referred to above which have and are significantly reducing playground injuries there is a growing theat to childrens' health when they are engaged in outdoor play and exercise in the sun shine.
The earth's protective atmosphere ozone layer has been significantly depleted due to release of chemical pollutants into the atmosphere during the last five decades. The result of the ozone depletion is that the solar ultraviolet (UV) rays are significantly more intense and comprise a serious health risk to children without protection when playing in the now unfiltered UV sun radiation.
In 1930 the risk of developing melanoma from sun exposure was 1 in 1500 people. Today a person's risk of developing skin cancer at some time during their life as a result of UV exposure is 1 in 75 people. Skin cancer is the most common cancer in the United States, with more than one million new cases diagnosed each year. Currently this year 47,700 Americans will be diagnosed with life threatening melanoma and 7,700 will die of the disease. The current prognosis for this disease is that approximately 1 out of 5 children in the United States will experience some form of skin cancer during their lifetime. Furthermore, exposure to the current intensity of solar UV radiation reduces the effectiveness of the immune system. This effect is of special importance in children's health.
Sources of the above statistics are to be found in publications of the American Academy of Dermatology, American Cancer Society, National Institutes of Health, U.S. Center for Disease Control and Protection and the Australian Cancer Society.
OBJECTS OF THE INVENTION
It is a first object of our invention to provide a sturdy, wind resistant, demountable canopy structure suitable for shading a childrens' play area from direct rays of the sun.
Another object of our invention is to provide a sturdy, wind resistant, demountable sun shade canopy for mounting on vertical support columns as used in childrens' standard safe outdoor play structures. The sun shade canopy structure as described herein, is in full compliance with recommended safety specifications for childrens' play areas.
Still another object of our invention is to provide a sturdy, wind resistant, demountable sun shade canopy design adaptable to retrofit existing small area and extended childrens' play area installations with effective sun shade protection.
These and other objects and advantages and diverse uses of our invention will be apparent from consideration of the following illustrations, specifications and claims.
BRIEF SUMMARY OF THE INVENTION
A demountable, wind resistant sun shade canopy suitable for mounting on a limited number of vertical columns, erected for the purpose of, or suitable for mounting on, extensions of a limited number of standard safe play area support columns. The canopy support structure, comprised of a plurality of uniquely shaped brackets which, when each is fixedly mounted, respectively, to the top of a vertical column, provides at each column a mount for a cantilever extending outward toward the perimeter of the area to be shaded, and simultaneously provides for mount of a hip beam extending toward the inner portion of the area to be shaded. Thus an extended-area rigid support structure is provided over a designated area which may be dependably shaded from the sun rays when a high density knitted polyethylene porous canopy cover is placed over the unique bracket supported plurality of cantilever and hip beam support members and secured about the perimeter of the canopy cover with an adjustable tension means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of an existing safe play structure without sun protection; the play structure is shown mounted above a resilient ground cover.
FIG. 2 is a cross section of the upper portion of a support column taken along the plane 2 — 2 .
FIG. 3 is a plane view of a specified safe design single tower childrens' play area on which our innovative sun shade canopy has been erected; the play and exercise devices are shown in phantom lines.
FIG. 4 is a sectional elevation view of the embodiment of our invention shown in FIG. 3 with portions of the play structures and canopy support members shown in phantom.
FIG. 5 is a perspective view of a construction bracket for mounting cantilever beam and hip beam members to form a support structure for mounting the canopy cover.
FIG. 6 is a cross section of the construction bracket shown in FIG. 5 taken on the plane 6 — 6 .
FIG. 7 is a plane view of the connector for the four hip beam canopy support members shown in the embodiment of our sun shade canopy illustrated in FIGS. 3 and 4.
FIG. 8 is a perspective view of the hip beam connector illustrated in FIG. 7 .
FIG. 9 shows detail of means for fastening the canopy cover to the support structure with adjustable tension means.
FIG. 10 shows a section of an extended end of the cantilever member showing means for securing the canopy cover.
FIG. 11 is an elevation view of a second embodiment of our sun shade canopy structure mounted to cover a two tower specified safe children's play area.
FIG. 12 is a plane view of the embodiment of our sun shade canopy shown in the embodiment illustrated in FIG. 11 . The children's play area devices are shown in phantom.
DETAILED DESCRIPTION OF THE INVENTION
A safe design childrens' play structure is illustrated in FIG. 1 wherein a plurality of fixedly mounted vertical columns 12 a , 12 b , 12 c and 12 d are shown. The columns 12 a , 12 b etc. are mounted in foundations (not shown) beneath a resilient ground cover 14 . The ground cover may be made of rubber or cork matted materials to soften impact and reduce injuries to a child falling thereon.
The columns support a platform 16 from which a slide 18 , a closed chute 20 and other childrens' climbing and exercise devices may be positioned.
The upper end of conventionally designed vertical columns 12 a , 12 b , 12 c , 12 d is shown in FIG. 2 in cross section on plane 2 — 2 . A column cap 22 fits over the top of the column 12 d . The cap 22 is shaped with a reduced diameter lower section 24 which, when inserted into the hollow opening 26 of the vertical column, comprises a secure mount for the column cap. Although such conventionally designed columns are fully compatible with the invention, in order to avoid the possibility of rainwater leaking into the seam between lower portion 24 and column 12 d , it is preferable to have the columns designed as depicted in FIG. 6, where the upper end of column 12 a , 12 b , etc. has a smaller diameter than bracket 52 so that rainwater will flow over the juncture between the two without entering the seam.
FIGS. 1 and 2 are illustrative of safe childrens' play structures in compliance with the safety specifications developed by the National Play and Playground Authorities, At this date there are tens of thousands of such play structures erected and being erected in the United States without provision for effective sun shade for children using such structures.
A plan view of a first embodiment of our invention is shown in FIG. 3 wherein a canopy cover 30 is shown supported over structural members described below which in turn are mounted above a children's play structure area. Children's exercise and play devices are shown at 32 in phantom lines below the canopy 30 .
A cross section elevation of the FIG. 3 embodiment is shown in FIG. 4 taken on plane 4 — 4 . Vertical columns 34 and 36 are fixedly mounted respectively in concrete foundation footings 40 and 42 . The vertical columns support a platform or deck 44 . The columns 34 , 36 terminate at approximately four feet above the platform or deck 44 . Caps 22 such as shown in FIG. 2 have been removed from the upper column portions 60 , 62 of the columns 34 , 36 exposing the tops 48 , 50 respectively, of columns 34 and 36 . Structural bracket fittings 55 and 57 have lower ends 56 , 58 , which, fit over the tops 48 , 50 of columns 34 and 36 .
FIGS. 5 and 6 are illustrative of the structural brackets fittings 55 and 57 ; more specifically, FIG. 5 depicts bracket 55 in a perspective cut-away fragmentary view while FIG. 6 is a view of the structural bracket 55 shown as a cross section on plane 6 — 6 . In preferred embodiments, the lower portion 56 of structural bracket 55 fits over the reduced diameter upper end 52 of the upper column portion 60 . In rainy weather, water will flow over the juncture of lower portion 56 and upper end 52 and will not enter the seam where it might cause damage.
The upper end of the bracket is terminated with a transverse angularly mounted cylindrical rod 64 . The rod 64 is mounted at an acute angle with the vertical cylinder extension. The angle with the horizontal is normally 22 degrees, but is subject to adjustment as required for specific application.
Mounted as shown in FIG. 5 and FIG. 6, the cylindrical rod 64 is mounted on a plate 83 which in turn is mounted at an angle relative to the horizontal to bracket rod 55 , said bracket rod 55 has an upper or first end 68 , and a lower or second end 70 . Hip beam 72 comprises a straight section of a hollow metal steel pipe or rod. The hip beam 72 is positioned over the upper, or first end 68 , of the angle mounted cylindrical rod 64 and secured with threaded bolt means 76 passed through the hip beam 72 and the cylindrical rod 64 .
The lower or second end 70 of the solid metal rod 64 is mounted over a cantilever beam 80 comprised of a straight section of hollow steel pipe at its upper end and secured with threaded means 81 . The lower end of the cantilever beam is terminated with an oblong eyelet connector 84 .
As shown in fragment view in FIGS. 7 and 8 the four hip beams 72 , 74 and counter parts 72 a , 74 a terminate in juxtaposition and are secured together with a right angle joint 86 .
Referring now to FIG. 3, a porous woven polyethylene canopy cover 30 is placed over the structure comprised of hip beam members 72 , 72 a , 74 , 74 a , and cantilever beam members 80 , 80 a , 82 , 82 a . The canopy details are more clearly shown in FIG. 9 . The canopy cover 30 is secured about its perimeter with a tension cable 90 which is secured within a cable channel 92 sewn about the canopy perimeter 94 . The tension on the cable 90 is adjusted and maintained with a turnbuckle 96 . The canopy cover 30 is provided at its four corners with a reinforced opening 98 through which the oblong eyelet connector 84 located on the extreme end of the cantilever beam 80 and its counterpart cantilever beams 82 , etc. protrudes.
A second embodiment of our invention is illustrated in FIGS. 11 and 12 wherein a two tower safe design children's play area is shown. The play and exercise devices are shown in phantom lines. A porous shade canopy 104 fabricated with woven polyethylene strips is constructed similarly to the single tower canopy cover 30 . The two tower canopy cover 104 is sewn so that it provides a cable channel 106 . A tension cable 108 is threaded through the channel 106 and when positioned over the metal support structure of hip beams 110 a , 110 b , 110 c , etc. ridge beam 112 and cantilever beams 114 a , 114 b , 114 c , etc. forms a sunshade canopy. A turnbuckle tension means 116 is attached to the ends of the cable 108 to provide adjustment and to maintain cable tension.
The canopy cover 104 is provided at each corner with a reinforced opening 98 as shown in FIG. 9, through which the oblong eyelet connector 84 on the cantilever beam extends.
The purposes and other advantages to our invention and possible application to sun sheltering purposes beyond those described in connection with children's play areas will be apparent from the following claims. | A demountable, wind-resistant sun shade canopy for shading childrens' play areas or other actively used areas. The canopy cover, being removably secured over a metal support structure, is comprised of vertical columns upon which are mounted at the upper end thereof respectively, uniquely configured bracket fittings, each bracket fitting providing secure mounting for a cantilever beam extending outwardly toward the perimeter of the area to be shaded, and providing secure mounting for a hip beam extending upward and toward the inner portion of the area to be shaded. | 4 |
FIELD OF THE INVENTION
This present invention relates generally to glass optical elements, and more particularly to molded glass optical elements with datum(s) formed therein in the molding process that decrease the difficulty of subsequent manufacturing steps.
BACKGROUND OF THE INVENTION
Various methods and apparatus for the compression molding of glass optical elements are known in the prior art. With these methods and apparatus, optical element preforms sometimes referred to as gobs are compression molded at high temperatures to form glass lens elements. The basic process and apparatus for molding glass elements is taught in a series of patents assigned to Eastman Kodak Company. Such patents are U.S. Pat. No. 3,833,347 to Engle et al., U.S. Pat. No. 4,139,677 to Blair et al., and U.S. Pat. No. 4,168,961 to Blair. These patents disclose a variety of suitable materials for construction of molds used to form the optical surfaces in the molded optical glass elements. Those suitable materials for the construction of the molds include glasslike or vitreous carbon, silicon carbide, silicon nitride, and a mixture of silicon carbide and carbon. In the practice of the process described in such patents, a glass preform or gob is inserted into a mold cavity with the mold being formed out of one of the above mentioned materials. The molds reside within a chamber in which a non-oxidizing atmosphere is maintained during the molding process. The preform is then heat softened by increasing the temperature of the mold to thereby bring the preform up to a viscosity ranging from 10 7 -10 9 poise for the particular type of glass from which the preform has been made. Pressure is then applied to force the preform to conform to the shape of the mold cavity. The mold and preform are then allowed to cool below the glass transition temperature of the glass. The pressure on the mold is then relieved and the temperature is lowered further so that the finished molded lens can be removed from the mold.
Molded glass lenses may be manufactured with upper and lower molds residing in a cylindrical mold sleeve (U.S. Pat. No. 5,718,850 to Takano et al.). In such a process the final molded lens element is typically cylindrical (and circular in cross-section). The diameter and concentricity of the cylinder are critical to subsequent handling, positioning and mounting operations. Therefore, it has been necessary to control the diameter of the cylinder either during molding, or during a subsequent grinding operation. Controlling the diameter during molding is difficult. Although a cylindrical mold sleeve produces a lens with a well-constrained outer diameter, molding tool life can be decreased due to a variety of factors. One contributor to decreased molding tool life is variability in the volume of the preforms. The preforms are the glass material (usually in the shape of a sphere) from which the lenses are molded. If the preform volume is slightly larger than the mold cavity, the excess glass can exert excessive force on the cylindrical sleeve during molding. It can also become difficult to remove the lenses from the cylindrical sleeve after multiple molding cycles.
Grinding a specified outer diameter on a lens after molding is often referred to as centering. As lens elements become smaller it becomes increasingly difficult to accurately center such lens elements as well as to position and align such elements in subsequent assembly operations.
A lens geometry is needed which allows for accurate centering, handling, positioning, and mounting operations and that does not rely on the accuracy of the outside diameter of the cylindrical body of the lens as molded.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a molded lens having a geometry that allows for accurate centering, handling, positioning, and mounting operations after molding.
It is a further object of the present invention to provide a molded lens having a geometry that does not rely on the accuracy of the outside diameter of the cylindrical body of the lens for post molding operations.
Yet another object of the present invention is to provide a molded lens having a geometry that is not critically dependent upon optical element preform volume for the creation of a reference surface.
Briefly stated, the foregoing and numerous other features, objects and advantages of the present invention will become readily apparent upon a review of the detailed description, claims and drawings set forth herein. These features, objects and advantages are accomplished by providing a molded lens that includes a molded two-dimensional reference surface at a first end of the lens body, a first molded optical surface that is longitudinally offset from the two-dimensional reference surface, and a molded second optical surface at a second end of the lens body. The first and second optical surfaces may be plano, convex or concave. The molded two-dimensional reference surface is an annular plano surface. The lens body (that portion of the lens that is between the second optical surface and the molded two-dimensional reference surface or the molded two-dimensional reference surface, and outside the diameters of the second optical surface and the molded two-dimensional reference surface) may be allowed to partially or fully free-form during molding or may be constrained during molding to provide a generally cylindrical shape to the lens body. If the lens body is allowed to free-form, it is subsequently subjected to a grinding operation to yield a generally cylindrical shape. Whether the generally cylindrical shape of the lens body is accomplished by molding or grinding, the generally cylindrical shape may include an additional datum surface(s) formed therein. Also, the molded lens of the present invention may include a molded three-dimensional reference surface at the second end of the lens body. If the molded lens includes a molded three-dimensional reference surface at the second end of the lens body, that reference surface will be interrupted by the second optical surface. The first and second optical surfaces are designed to image light from an object point to an image point. The molded two-dimensional reference surface is of a specified shape and location with respect to the first and second optical surfaces. By physically locating the lens with the molded two-dimensional reference surface and one of the first or second optical surfaces, the lens can be held in a given orientation. Thus, the molded reference surface(s) at the end(s) of the cylindrical body allow for accurate and safe capture, positioning, handling, and placement for subsequent finishing operations, allowing for the creation of one or more additional lens datums. These finishing operations can include, but are not limited to, grinding, polishing and cutting. These functions of capture, positioning, handling, and placement for subsequent operations can be performed using a centering cup that engages the molded reference surface(s) at the end(s) of the cylindrical body thereby allowing subsequent operations to be performed without reliance on the outside diameter of the lens body.
As mentioned above, the first molded optical surface is longitudinally offset from the two-dimensional reference surface. That is, the first molded optical surface is positioned along the cylindrical or optical axis of the lens but the two-dimensional reference surface and the first molded optical surface reside at different distances from the second optical surface. The offset may be such that the first molded optical surface is closer to or further from the second optical surface as compared to the molded two-dimensional reference surface. In other words, the offset may take the form of an axial recess or an axial projection. In fact, the offset may be simultaneously a partial axial recess and a partial axial projection.
The lens of the present invention can be made with an angled plano optical surface, a convex optical surface and a lens datum. This lens datum can then be used for subsequent processing operations (such as grinding) to add additional datums to the lens. These additional datums can be placed in a precise location with respect to the optical axis of the lens element. One of the additional lens datums can be a cylindrical surface that enables mounting of the lens either in a V-groove type structure or in a precise tube. In addition, the lens can be molded without the need for a precisely controlled cylindrical preform. The lens can be centered using existing centering equipment. Because the lens does not have to be held on the optical plano surface, it reduces the chances of scratching this surface. Scratches can lead to scatter and reduce the light transmitted by the lens. This is particularly important for situations where the beam diameter of the light directed onto the plano optical face may be only 50 microns such as those optical elements used in conjunction with optical fibers. In such an instance, a scratch of only a few microns in size could cause a measurable decrease in the amount of light transmitted by the lens to the receiving fiber.
Either as a result of a post-molding grinding operation or as result of the molding operation itself, the lenses of the present invention typically will be “generally cylindrical.” Further, such lenses will typically be circular in cross-section. However, there may be lens applications where it is beneficial to form generally cylindrical lenses which, in cross-section perpendicular to lens axis, are not circular (e.g. elliptical). Thus, the term “generally cylindrical” as used herein is intended to include cylindrical lenses that may or may not be circular in cross-section. In addition, the term “generally cylindrical” as used herein is intended to include those lenses which have datum(s) formed in the cylindrical surface thereof such as, for example, flat datum(s) and recessed datum(s) as will be discussed in more detail hereafter. Therefore, the formation of such datum(s) in the cylindrical surface of a lens will not remove such lens from the definition of “generally cylindrical” as used herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an exemplary lens of the present invention including a two-dimensional reference surface;
FIG. 2 is a side elevational view of the exemplary lens depicted in FIG. 1;
FIG. 3 is a cross-sectional schematic view of an apparatus with a preform positioned therein at the beginning of a molding sequence;
FIG. 4 is a cross-sectional schematic view of the apparatus of FIG. 3 with the apparatus actuated to compress the preform to yield an exemplary molded lens of the present invention with a free-form lens body or perimeter;
FIG. 5 a is a cross-sectional schematic view of the apparatus of FIGS. 3 and 4 with the apparatus actuated to release the exemplary molded lens with a free-form lens body or perimeter formed thereby;
FIG. 5 b is a side elevational view of an exemplary lens as molded with the apparatus depicted in FIG. 5 a;
FIG. 6 a is a cross-sectional schematic view of an alternative apparatus to that shown in FIGS. 3 through 5 a for molding a lens of the present invention;
FIG. 6 b is a side elevational view of an exemplary lens as molded with the apparatus depicted in FIG. 6 a;
FIG. 7 is a side elevational view of another exemplary molded glass lens of the present invention which includes a two-dimensional reference surface at one end thereof and a three-dimensional reference surface at the opposite end thereof;
FIG. 8 is a side elevational view of yet another exemplary molded glass lens of the present invention and including a longitudinal flat reference surface formed on the lens body;
FIG. 9 is a plan view taken from the perspective of line 9 — 9 of FIG. 8;
FIG. 10 is a side elevational view of yet another exemplary molded glass lens of the present invention including a two-dimensional (planar) reference surface, and a recessed reference surface formed on the lens body;
FIG. 11 is a schematic depicting one potential use of two of the lenses of the present invention in an optical fiber communications component;
FIG. 12 a is a schematic showing typical center of curvature separation, d, of a prior art lens;
FIG. 12 b is a shematic illustrating that the center of curvature separation, d, of a plano-convex lens is infinite;
FIG. 13 is a schematic showing how the lens of the present invention can be used to increase the center of curvature separation, d, of the lens;
FIG. 14 is a schematic side elevational view of an exemplary lens of the present invention supported between two centering cups in a post molding grinding operation to achieve a generally cylindrical lens body; and
FIGS. 15 a through 15 f show cross-sectional views of various exemplary lenses of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Turning first to FIGS. 1 and 2, there is depicted an exemplary molded glass lens 10 of the present invention. Lens 10 includes a lens body 12 that is cylindrical (and in this example, circular in cross-section). At a first end of lens body 12 is a molded two-dimensional reference surface 14 . The molded two-dimensional reference surface 14 is a plano surface that is preferably annular. There is a first molded optical surface 16 that is longitudinally displaced or offset from the molded two-dimensional reference surface 14 . That offset may take the form of a recess or a projection. An exemplary projection 15 is depicted in FIG. 1 . As depicted, exemplary projection 15 includes an intermediate surface 17 residing between the molded two-dimensional reference surface 14 and the first molded optical surface 16 . The intermediate surface 17 is preferably tapered (such as, for example, to form a frusto-conical shape) to facilitate removal of the lens from the mold. There is a molded second optical surface 18 at a second end of the lens body 12 . The first and second molded optical surfaces 16 , 18 may be plano, convex or concave.
As described above, the molded two-dimensional reference surface 14 is a plano surface that is preferably annular. The actual shape of molded two-dimensional reference surface 14 will typically depend, however, on the cross-sectional shape of the lens body 12 and the shape of recess or projection which forms the base for the first molded optical surface 16 .
As depicted in FIGS. 1 and 2, first molded optical surface 16 is plano and molded second optical surface 18 is convex. Note that although first molded optical surface 16 is plano, it does not have to be perpendicular to the cylindrical axis 20 of lens 10 . This geometry has particular advantage in some collimating lens applications, which will be discussed in more detail hereinafter.
Looking next in FIGS. 3 through 5 b , there is shown a cross-sectional view of an apparatus 22 for producing the molded glass lens 10 of the present invention depicting a molding sequence. The apparatus 22 of the present invention includes an upper mold 24 and a lower mold 26 . Upper mold 24 resides in an upper mold support 28 and lower mold 26 resides in a lower mold support 30 . The upper mold 24 includes a first optical mold surface 32 . First optical mold surface 32 is depicted as being concave but may include other optical geometries such as convex or plano features. The lower mold 26 includes a two-dimensional reference mold surface 34 and a second optical mold surface 36 . Surrounding upper and lower molds 24 and 26 is an induction heating coil 40 . In operation, a glass preform 38 (depicted as being spherical) with an optical quality surface is inserted into the depression in the lower mold 26 defined by the two-dimensional reference mold surface 34 and the second optical mold surface 36 . Through actuation of the induction heating coil 40 , the temperature of the upper and lower molds 24 , 26 and preform 38 is raised to at least the glass transition temperature of the preform 38 . Then the preform 38 is pressed between the upper and lower molds 24 , 26 causing the preform 38 to deform as depicted in FIG. 4, thereby imparting to the preform 38 first and second optical mold surfaces 32 , 36 and molded two-dimensional reference surface 14 . Compression is performed (by means not shown) to a positive stop at which point the molds 24 , 26 and the preform 38 are allowed to cool to below the glass transition temperature and preferably to below the annealing point of the glass. The volume of the cavity 42 defined by molds 24 , 26 and mold support 28 , 30 within the mold position as depicted in FIG. 4 is significantly greater than the volume of the preform 38 . Once the molds 24 , 26 and the preform 38 cool, molds 24 , 26 are parted as depicted in FIG. 5 a . In such manner, a molded glass lens 44 (See FIG. 5 b ) is molded which includes a lens body 46 with a free-formed perimeter 48 , a molded two-dimensional reference surface 50 , a first molded optical surface 52 displaced longitudinally from the molded two-dimensional reference surface 50 , and a molded second optical surface 54 . The molded two-dimensional reference surface 50 is an annular plano surface. The conical surface 51 is tapered to facilitate easy removal of the lens 44 from the mold. The free formed perimeter 48 is then preferably subjected to a grinding operation to produce a cylindrical lens body. In this manner, a finished lens 10 such as depicted in FIG. 1 is produced. The grinding operation can be efficiently performed as centering of the lens 44 is accomplished using the two-dimensional reference surface 50 . Molds 24 , 26 may be made of a machinable material (such as electroless nickel) thereby allowing both molds 24 , 26 to be machined. Alternatively, molds 24 , 26 may also be made from a material that cannot be easily machined, such as glass or ceramic, by forming molds 24 , 26 by machining mold tools which have surfaces that are negatives of the desired surfaces for molds 24 , 26 . Then molds 24 , 26 can be molded using such negative or inverse mold tools.
It should be understood that upper and lower molds 24 , 26 are not necessarily directly heated by induction. Rather, upper and lower molds 24 , 26 preferably reside in mold supports 28 , 30 fabricated from a conductive material such as graphite or molybdenum. The mold supports 28 , 30 are heated by the induction heating coil 40 and the upper and lower molds 24 , 26 are heated indirectly by conduction and radiant heat transfer.
It should be understood that two-dimensional reference mold surface 34 does not have to be of the highest optical quality, since two-dimensional reference surface 14 will not be used to transmit light. However, the quality of two-dimensional reference mold surface 34 will affect subsequent centering operations.
Looking next at FIGS. 6 a and 6 b , there is shown an alternative apparatus 60 for molding an exemplary molded glass lens 61 of the present invention. Apparatus 60 includes an upper mold 62 and a lower mold 64 . Upper mold 62 resides in an upper mold sleeve 66 and lower mold 64 resides in a lower mold sleeve 68 . The upper mold 62 includes a first optical mold surface 70 . First optical mold surface 70 is depicted as being concave, but may include other optical geometries such as convex or plano features. The lower mold 64 includes a two-dimensional reference mold surface 72 and a second optical mold surface 74 . Operation of apparatus 60 is similar to operation of apparatus 22 . A glass preform 73 with an optical quality surface is inserted into the lower mold sleeve 68 and on top of lower mold 64 . The glass preform 73 used in the apparatus 60 as depicted is preferably cylindrical with spherical ends. The spherical ends would have optical quality surfaces. Through actuation of an induction heating coil, or other heating means, the temperature of the upper and lower molds 62 , 64 and preform 73 is raised to at least the glass transition temperature of the preform 73 . Then the preform 73 is pressed between the upper and lower mold 62 , 64 and confined by the upper and lower mold sleeves 66 , 68 causing the preform 73 to deform to the shape of the mold cavity 75 defined thereby. In this manner, the first and second optical mold surfaces 76 , 78 and the molded two-dimensional reference surface 80 are imparted to the preform 73 yielding lens 61 as depicted in FIG. 6 b . The conical surface 77 is tapered to facilitate easy removal of lens 61 from the mold. Compression is performed (by means not shown) to a positive stop at which point the molds 62 , 64 and the lens 61 are allowed to cool to below the glass transition temperature and preferably to below the annealing point of the glass. At that point, upper and lower molds 62 , 64 and upper and lower mold sleeves 66 , 68 can be separated and lens 61 can be removed. Preferably, upper and lower mold sleeve 66 , 68 join one another in an interlocking arrangement as shown in FIG. 6 a . Preferably, mold cavity 75 includes an annular channel 82 projecting into upper and lower mold sleeves 66 , 68 proximate to where upper and lower mold sleeves 66 , 68 are above one another when in molding position. In the embodiment depicted in FIG. 6 a , one-half of annular channel 82 is formed in upper mold sleeve 66 , and one-half of annular channel 82 is formed in lower mold sleeve 68 . Annular channel 82 allows for the volume of the preform 73 which is somewhat larger than the volume of the main portion of mold cavity 75 . In this manner, lens 61 can be formed with a generally cylindrical shape while avoiding putting too much pressure on upper and lower sleeves 66 , 68 during molding operation. In other words, annular channel 82 provides a reservoir into which excess glass can flow. The excess glass that flows into annular channel 82 can be subjected to a subsequent grinding operation and removed thereafter.
Those skilled in the art will recognize that the lens of the present invention could be formed with a mold apparatus similar to that depicted in FIG. 6 a but having only a single sleeve rather than a split sleeve. However, a single sleeve would prevent the inclusion of annular channel 82 in the mold cavity. Such a design would have problems associated therewith. These problems are particularly true when molding glass optical elements that are only about 2 mm or less in diameter. Maintaining control of the inner diameter of a bore that is only about 2 mm in diameter is difficult. Furthermore, repeated glass pressing operations tend to degrade the surface quality inside the bore, leading to increased probability of the lens sticking in the mold. In this type of molding operation the variability of preform volume must be controlled very precisely to reduce potential stresses that might damage the sleeve.
The lens of the present invention can be molded to include more than one datum or reference surface. Looking at FIG. 7, there is depicted another exemplary molded glass lens 100 of the present invention which includes two reference surfaces. Lens 100 includes a lens body 102 that is cylindrical (and in this example, circular in cross-section). At a first end of lens body 102 is a molded two-dimensional reference surface 104 . There is a first molded optical surface 106 that is displaced longitudinally from the molded two-dimensional reference surface 104 . The molded two-dimensional reference surface 104 is an annular plano surface. At a second end of lens body 102 is a molded three-dimensional reference surface 107 . The molded three-dimensional reference surface 107 is curvilinear and may be a spherical, aspherical or conical segment. As such, the second molded optical surface 108 may be thought of as interrupting the three-dimensional reference surface 107 . The second molded optical surface 108 abutts and is formed integrally with molded three-dimensional reference surface 107 . The first and second optical surfaces 106 , 108 may be plano, convex or concave. As depicted in FIG. 7, first molded optical surface 106 is plano and second molded optical surface 108 is convex. Note that although first molded optical surface 106 is plano, it does not have to be perpendicular to the cylindrical axis 109 of lens 100 . This geometry has particular advantage in some collimating lens applications which will be discussed in more detail hereinafter. However, for other lens applications which include a plano optical surface it may be preferred to have the plano surface perpendicular to the cylinder and/or optical axis of the lens. This embodiment of the invention allows independent location of the center of curvatures of the two reference surfaces 104 , 107 that are held in the cups during a centering operation. That is, the location of the lens for grinding does not depend on the molded optical surfaces 106 , 108 that are used to implement the optical function of the lens 100 .
FIGS. 8 and 9 show yet another exemplary molded glass lens 110 of the present invention. Exemplary lens 110 is similar to lens 10 . Lens 110 includes a lens body 112 that is cylindrical (and in this example, circular in cross-section). At a first end of lens body 112 is a molded two-dimensional reference surface 114 . There is a first molded optical surface 116 longitudinally displaced from the molded two-dimensional reference surface 114 . The molded two-dimensional reference surface 114 is an annular plano surface. There is a molded second optical surface 118 at a second end of the lens body 112 . The first and second optical surfaces 116 , 118 may be plano, convex or concave. As depicted in FIGS. 8 and 9, first molded optical surface 116 is plano and second molded optical surface 118 is convex. As shown, first molded optical surface 116 is plano but is not perpendicular to the cylindrical axis 120 of lens 110 . However, first molded optical surface 116 may be formed to be perpendicular to the cylindrical axis 120 of lens 110 depending on the particular lens application.
In this alternate lens embodiment, the molded datum (molded two-dimensional reference surface 114 ) allows the addition of two other datums. The first added datum is a cylindrical surface 122 , the axis of which is coincident with the optical axis of the lens 110 . The second added datum is a flat reference surface or datum 126 . The flat reference surface 126 is parallel to the axis 120 of the cylindrical datum surface 122 . The flat surface 126 can be used during placement of the lens into an assembly to constrain the rotational orientation of the lens about the aspheric axis (which is assumed to be coincident with the axis of the created cylindrical datum). Preferably, datums 122 , 126 are formed during the molding process. However, datums 122 , 126 may also be formed in subsequent grinding operation(s) after the molding process is completed. When the lens body 112 is allowed to free-form in the molding operation, then it is necessary to form datums 122 , 126 in subsequent grinding operations.
FIG. 10 shows yet another exemplary molded glass lens 130 of the present invention. Exemplary lens 130 is also similar to lens 10 . Lens 130 includes a lens body 132 that is cylindrical (and in this example, circular in cross-section). At a first end of lens body 132 is a molded two-dimensional reference surface 134 . There is a first molded optical surface 136 displaced longitudinally from the molded two-dimensional reference surface 134 . The molded two-dimensional reference surface 134 is an annular plano surface. There is a molded second optical surface 138 at a second end of the lens body 132 . The first and second optical surfaces 136 , 138 may be plano, convex or concave. As depicted in FIG. 10, first molded optical surface 136 is plano and second molded optical surface 138 is convex. As shown, first molded optical surface 136 is plano but is not perpendicular to the cylindrical axis 140 of lens 130 . However, first molded optical surface 136 may be formed to be perpendicular to the cylindrical axis 140 of lens 130 depending on the particular lens application. Lens 130 also includes a recess 142 formed therein. Recess 142 would be formed in a subsequent grinding operation after molding. The recess 142 allows relatively precise axial location of the lens 130 . Such a recess 142 could make subsequent placement, inspection and alignment of the lens 130 in an optical assembly easier. Those skilled in the art will recognize that although recess 142 is preferably annular, recess 142 may comprise one or more non-contiguous recess segments.
As mentioned above, the geometry of lens 10 as depicted in FIG. 1, where the first molded optical surface 16 is plano but does not have to be perpendicular to the cylindrical axis 20 of lens 10 has particular advantage in some collimating lens applications. Looking at FIG. 11, when light is transferred from a first optical fiber 150 to a second optical fiber 152 , it is often accomplished with a pair of lenses 154 , 156 . The first lens 154 collimates the output of the emitting fiber 150 , and the second lens 156 focuses that collimated beam 158 into the receiving fiber 152 . Other optical components (not shown) may be placed between these two lenses 154 , 156 in the collimated beam 158 of light such as dichroic filters, beam splitters or birefringent materials that separate the beams. For these systems, it is desirable that the collimating optics be small. This minimizes the size of any supplemental optics, and decreases the overall package size. The optics must also work over a wide wavelength and temperature range. Glass optical elements are desired over plastic due to lower thermal and environmental sensitivity. In the manufacture of assemblies that use optical components such as lenses, it is desirable that the lenses have datums that can be used for accurately locating the lenses in the assembly. When using a lens 154 to collimate light from an optic fiber 150 , it is not desirable to have an optical surface 162 that is nearly perpendicular to the beams. A perpendicular optical surface may reflect light back along the same path, and back into the fiber. This reflected light could affect the laser source used in telecommunication systems. One possible design for a collimating lens element 154 which would overcome this reflection problem is to have plano optical surface 162 angled to the optical axis, and the second optical surface 164 be a convex asphere.
Thus, the lens of the present invention describes a way of making lenses with an angled rear facet surface and producing a known datum on the lens. The inclusion of the known datum reduces difficulties in the subsequent centering operations.
As mentioned above, the lens of the present invention allows more efficient centering operations. When centering lenses, it is desirable that the separation between the center of curvatures of the optical surfaces be a large as possible. FIG. 12 a shows a molded glass lens 170 with two convex optical surfaces 172 and 174 and having corresponding radii of curvature, R 1 and R 2 , respectively. In this case, the center of curvature separation d is quite small making it difficult to grind the outside diameter of the lens precisely with respect to the optical axis.
FIG. 12 b shows a lens 175 with a plano surface 176 and a convex surface 178 . In this case the radius of curvature of the plano surface is infinite which causes the center of curvature separation d to also be infinite. This will greatly faciliate the centering of this plano-convex lens. The plano surface 176 minimizes the tilt of the centered lens 175 , and the convex surface 178 minimizes the decentration of the centered lens 175 . FIG. 12 b shows a plano-convex lens, but the present invention can also be used on a plano-concave lens.
In the special case of a sphere, the center of curvature separation is zero and the ability to precisely center the lens become very difficult. A molded glass lens 180 of the present invention is depicted in FIG. 13 which includes convex optical surfaces 182 , 184 . Convex optical surfaces 182 , 184 may both be spherical and of the same radius. By adding a two-dimensional reference surface 186 to the lens 180 , the center of curvature separation d as defined by the reference surface 186 and convex optical surface 184 becomes infinite, making the centering operation much easier.
As mentioned above, the molded lens of the present invention allows for ease of centering using standard optical centering equipment. In normal use, this equipment is used to center optical lenses with two spherical surfaces. It is understood that the equipment can also be used to center lenses with aspheric surfaces. Referring to FIG. 14, there is shown an exemplary lens 10 of the present invention (FIG. 1) supported between two centering cups 190 , 192 . The first centering cup 190 engages two-dimensional reference surface 14 . The second centering cup engages the second molded optical surface 18 . As previously noted, the two-dimensional reference surface 14 is an annular plano surface. By way of example, FIG. 14 depicts a lens 10 positioned for removal of excess material using a grinding wheel 194 .
EXAMPLE
An exemplary lens of the present invention similar to that depicted in FIGS. 1 and 2 was successfully molded from Schott SF-57 glass. The lens produced was a plano-convex collimator lens intended to be used in an arrangement similar to that shown in FIG. 11 . The plano optical surface 16 was inclined by approximately 8° from being perpendicular to the cylindrical axis 20 to reduce back reflections into the transmitting optical fiber. An annular plano two-dimensional reference surface 14 was molded into the end of lens 10 that contained the plano optical surface 16 . The plano optical surface 16 was displaced longitudinally from the two-dimensional reference surface 14 . An aspheric optical surface 18 was integrally molded at the opposite end of lens 10 . The purpose of the aspheric optical surface 18 is to collimate the optical beam. The apparatus used to form the lens 10 was similar to that depicted in FIGS. 3 through 5. A spherical preform 38 was placed into the mold and heated to approximately 500° C. The spherical preform 38 was then compressed between upper and lower molds 24 , 26 for approximately 30 seconds and then cooled. Once the upper and lower molds 24 , 26 were separated, the molded lens 44 was removed and placed in a plastic tray. Subsequent to molding, the lens 44 was coated with an anti-reflection coating optimized at 1550 nm. Following this, the excess glass was removed using a conventional optical lens centering machine to yield a final lens geometry similar to that shown in FIGS. 1 and 2. Two centering cups 190 , 192 were used to align the optical axis of the lens to the mechanical axis of the centering machine similar to the arrangement shown in FIG. 14 . One cup 190 contacted the annular plano two-dimensional reference surface 14 and the other cup 192 contacted the aspheric optical surface 18 .
As mentioned above, the first molded optical surface 16 is longitudinally offset from the two-dimensional reference surface 14 . The offset may be such that the first molded optical surface 16 is closer to or further from the second molded optical surface 18 as compared to the molded two-dimensional reference surface 14 . In other words, the offset may take the form of an axial or longitudinal recess or an axial or longitudinal projection. In fact, the offset may be simultaneously a partial axial recess and a partial axial projection. FIGS. 15 a through 15 f show cross-sectional views of various exemplary lenses of the present invention. FIGS. 15 a and 15 b depict offsets that are exemplary of axial recesses. FIGS. 15 c and 15 d depict offsets that are exemplary of axial projections. FIGS. 15 e and 15 f depict exemplary offsets that are simultaneously partially axially recessed and partially axially projecting.
Those skilled in the art will recognize that although the lenses of the present invention are discussed herein as being individually molded, small versions (having diameters of 2 mm or less) of such lenses can be molded in arrays. The upper and lower mold would include cavities for molding multiple lenses as part of a single integrally formed sheet. The individual lenses could then be singulated in a subsequent cutting operation.
From the foregoing, it will be seen that this invention is well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are apparent and which are inherent to the apparatus.
It will be understood that certain features and subcombinations are of utility and may be employed with reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth and shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
PARTS LIST
10 molded glass lens
12 lens body
14 two-dimensional reference surface
15 exemplary projection
16 first molded optical surface
17 intermediate surface of exemplary projection 15
18 second molded optical surface
20 cylindrical axis
22 apparatus
24 upper mold
26 lower mold
28 upper mold support
30 lower mold support
32 first optical mold surface
34 two-dimensional reference mold surface
36 second optical mold surface
38 glass preform
40 induction heating coil
42 cavity
44 molded glass lens
46 lens body
48 free-formed perimeter
50 molded two-dimensional reference surface
51 conical surface
52 first molded optical surface
54 second molded optical surface
60 alternative apparatus
61 molded glass lens
62 upper mold
64 lower mold
66 upper mold sleeve
68 lower mold sleeve
70 first optical mold surface
71 induction heating coil
72 two-dimensional reference mold surface
73 glass preform
74 second optical mold surface
75 mold cavity
76 first optical mold surface
77 conical surface
78 second optical mold surface
80 molded two-dimensional reference surface
82 annular channel
100 molded glass lens
102 lens body
104 molded two-dimensional reference surface
106 first molded optical surface
107 molded three-dimensional reference surface
108 second molded optical surface
109 cylindrical axis
110 molded glass lens
112 lens body
114 molded two-dimensional reference surface
116 first molded optical surface
118 second molded optical surface
120 cylindrical axis
122 cylindrical surface or datum
126 flat reference surface or datum
130 molded glass lens
132 lens body
134 molded two-dimensional reference surface
136 first molded optical surface
138 second molded optical surface
140 cylindrical axis
142 recess
150 first optical fiber
152 second optical fiber
154 first lens
156 second lens
158 collimated beam
162 first optical surface
164 second optical surface
170 molded glass lens
172 convex optical surface
174 convex optical surface
175 molded glass lens
176 plano surface
178 convex optical surface
180 molded glass lens
182 convex optical surface
184 convex optical surface
186 two-dimensional reference surface
190 first centering cup
192 second centering cup
194 grinding wheel
d center of curvature separation
R 1 radius of curvature
R 2 radius of curvature | A molded glass lens is taught that includes a molded two-dimensional reference surface at a first end of the lens body, a first molded optical surface that is longitudinally displaced from the two-dimensional reference surface, and a molded second optical surface at a second end of the lens body. The first and second optical surfaces may be plano, convex or concave. The molded two-dimensional reference surface is planar and preferable annular. By physically locating the lens with the molded two-dimensional reference surface and one of the first or second optical surfaces, the lens can be held in a given orientation. Thus, the molded reference surface at the end of the cylindrical body allows for accurate and safe capture, positioning, handling, and placement for subsequent finishing operations, allowing for the creation of one or more additional lens datums. | 2 |
CROSS-REFERENCE
This application is a divisional of application Ser. No. 10/008,881, filed Nov. 8, 2001, entitled “2N Mask Design and Method of Sequential Lateral Solidification,” invented by Mark Albert Crowder, now U.S. Pat. No. 6,767,804, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to sequential lateral solidification (SLS).
One method of SLS, which may be referred to as the “2-shot process,” has been investigated for use in high-throughput processes. In this process, small beamlets, or a small beamlet, are projected onto regions of a silicon film overlying another substrate to induce melting and solidification (also referred to as “crystallization”) of large-grained polycrystalline silicon material. This may be referred to as a first shot. The small beamlets are then advanced and the process repeated such that the melted and solidified regions of this second shot overlap the regions of the first shot.
This process may be accomplished by using a single array of beamlets and making two or more passes over a given region of silicon film and microtranslating the array between passes. The process may also be accomplished by using multiple arrays of beamlets that are staggered with respect to each other and scanning the entire pattern in a across the silicon film. A single beamlet may also be used to iteratively stitch together crystallized regions, although this offers poor throughput.
The material produced using the above described process has severe directionality effects. The material has a plurality of narrow rectangular crystal grains oriented with the long axis perpendicular to the beamlet length.
As these directional effects are generally undesirable, a 2+2 process may be used to reduce, or eliminate, these directional effects. This may be accomplished by following up a first 2-shot process with a second 2-shot process carried out in a direction orthogonal to the first. This has been carried out by crystallizing silicon with an initial 2-shot process, rotating the sample being crystallized by 90 degrees, and then carrying out the second 2-shot process.
The need to rotate the sample by 90 degrees decreases throughput of the system, and adds complexity to the stage system for carrying out the SLS process.
SUMMARY OF THE INVENTION
Accordingly, a mask design is provided which enables a 2+2 process to be accomplished without the need to rotate the mask or the substrate relative to each other. This reduces the complexity of stages or mask mounts, and improves the angular alignment of the multiple 2-shot processes. The mask comprises a first set of two arrays of beamlets oriented substantially parallel to each other, and a second set two arrays of beamlets oriented at an angle, for example 90 degrees, relative the first set of two arrays.
The first set of two arrays is arranged so that a second array of beamlets is offset relative to a first array of beamlets, such that when the mask is transitioned the second array of beamlets will fill the gap between the first array of beamlets and slightly overlap the first array of beamlets.
A method of using the mask to accomplish a 2N processing is also provided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a 2+2 mask design.
FIG. 2 shows a region of material prior to SLS processing.
FIG. 3 shows the region of material during a first irradiation exposure.
FIG. 4 shows the region of material following the first irradiation exposure and crystallization.
FIG. 5 shows the region of material during a second irradiation exposure.
FIG. 6 shows the region of material following the second irradiation exposure and crystallization.
FIG. 7 shows the region of material during a third irradiation exposure.
FIG. 8 shows the region of material following the third irradiation exposure and crystallization.
FIG. 9 shows the region of material during a forth irradiation exposure.
FIG. 10 shows the region of material following the forth irradiation exposure and crystallization.
FIG. 11 is a view of a 2+2+2+2 mask design.
FIG. 12 is a view of a portion of a mask design.
FIG. 13 is a view of one alternative 2+2 mask design.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is one embodiment of a mask 10 for a 2+2 shot process, which eliminates the need to rotate the substrate ninety degrees relative to the mask. Systems that rotate the substrate ninety degrees relative to the mask require complicated stage or mask retaining systems. Also it is difficult to achieve a precise ninety degree rotation, to the tolerance desired to produce optimal crystal structures. The precision of modern mask design allows the mask 10 to produce sets of beamlets which are much more precisely ninety degrees relative to another set of beamlets. This allows the mask design 10 to produce crystals that have more precisely orthogonal structures.
The mask 10 comprises a first set of slits 12 and a second set of slits 14 , which are at a desired angle relative to the first set of slits. In one embodiment, the desired angle may be ninety degrees. The first set of slits consist of two arrays of beamlets, a first array of beamlets 16 and a second array of beamlets 18 . The first array of beamlets 16 and the second array of beamlets 18 are preferably arranged adjacent to each other, substantially parallel to each other, and offset relative to each other with a slight overlap. The two arrays of beamlets that comprise the first set of slits 12 may be used in a first 2-shot process. For illustration, a laser source (not shown) is projected through the first array of beamlets 16 to crystallize a layer of material (not shown). The mask 10 is then stepped in the direction indicated by the arrow in FIG. 1 . The second array of beamlets 18 is then used to crystallize the layer of material. The crystallized region formed by the first array of beamlets 16 , and the crystallized region formed by the second array of beamlets 18 may intersect to form a continuous crystallized region. The intersection of the crystallized regions may be accomplished by having a slight overlap of the crystallized regions for the first array of beamlets and the second array of beamlets.
As the mask 10 is moved again in the direction indicated by the arrow, the second set of slits will be projected, at least partially, over regions of material which have previously been crystallized by the first set of slits. The second set of slits comprises a third array of beamlets 22 and a fourth array of beamlets 24 . The third array of beamlets 22 and the fourth array of beamlets 24 are preferably parallel to each other. After the third array of beamlets 22 has been used to crystallize portions of a region of material, the mask 10 is moved again. The forth array of beamlets 24 then slightly overlaps the regions crystallized by the third array of beamlets and crystallizes this region. The second set of slits effectively produces a second 2-shot process. Accordingly, the mask 10 shown in FIG. 1 accomplishes a 2+2 process without rotating the stage relative to the mask. As shown, the first set of slits is oriented horizontally and the second set of slits is oriented vertically. It is also entirely possible, to have the first set of slits oriented vertically and the second set of slits oriented horizontally.
FIG. 2 shows a region of material 30 that has been deposited over a substrate. The material is preferably amorphous material although it may contain microcrystals or be polycrystalline. The material is preferably silicon, germanium, copper, silicon germanium, or aluminum.
FIG. 3 illustrates irradiation of regions exposed by the first array of beamlets 16 . The irradiation is provided by a suitable irradiation source, including an electron beam, ion beam or laser irradiation. If laser irradiation is used the source may be a uv laser, such as an excimer laser. An excimer laser may be used at 308 nm for example. The region of material under the beamlets crystallizes by melting and solidifying. The region preferably crystallizes from the edges of the beamlets inward toward the center of the beamlets.
FIG. 4 shows regions 40 crystallized by the first shot. The adjacent regions 42 remain in essentially their as deposited condition, which may be amorphous. After the regions 40 have been crystallized the mask 10 is advanced.
FIG. 5 illustrates irradiation of regions exposed by the second array of beamlets 18 . The second array of beamlets 18 preferably irradiate the adjacent regions 42 with a slight overlap into the previously crystallized regions 40 . The adjacent regions 42 are then crystallized. This corresponds to the second shot in a two shot process. Although a 2-shot process is shown, it is also possible to use additional shots to crystallize the material in smaller segments. For example, a three shot process could be used.
FIG. 6 shows regions 42 crystallized by the second shot, along with regions 40 which were crystallized by the first shot. The resulting crystallized material is characterized by directional effects of crystallization illustrated by the grain boundaries 46 , along with high angle crystal boundaries 48 at the centerline of each beamlet, as denoted by the dotted line.
To reduce the directional effects in the crystallized material. The material may be recrystallized at a different angle. This is accomplished by advancing the mask 10 , and irradiating the crystallized material with the third array of beamlets 22 . The third array of beamlets is oriented at an angle relative to the first array of beamlets and the second array of beamlets 18 . The angle is preferably 90 degrees, as shown in FIG. 7 .
FIG. 8 shows regions 50 following crystallization. It should be noted that the directional effects in regions 50 have been reduced. Those in the adjacent regions 52 still show the directional effects of the previous crystallization process, also referred to as the first 2-shot process. The mask 10 is then advanced again.
FIG. 9 illustrates the forth array of beamlets 24 irradiating the adjacent regions 52 with a slight overlap into the regions 50 which were crystallized using the third array of beamlets 22 .
FIG. 10 shows the material following irradition using the forth array of beamlets 24 . Irradiation with the third array of beamlets 22 and the forth array of beamlets 24 corresponds to a second two shot process. The mask 10 has enabled the completion of a 2+2 process without the need to rotate the mask and stage relative to each other. Although, some directional effects remain, the directional effects have been significantly reduced.
The use of the mask 10 has allowed a 2+2 process to be completed without the need to rotate the mask relative to the material. This improves throughput, reduces the complexity of the stage or mask system; and provides greater precision in the angular alignment of the masks with respect to each other.
The mask 10 can be expanded to allow for further processing such as a 2+2+2 process, or 2+2+2+2 process, etc. FIG. 11 shows the mask 10 for use in a 2+2+2+2 process. Additional 2-shot processes, may further reduce directional effects and improve the overall crystal characteristics of the crystallized material. Multiple 2-shot processes can be referred to as a 2N process, where N is the number of 2-shot processes. For the mask shown in FIG. 11 , N equals 4. There may eventually be a point of diminishing returns at which point no measurable improvement in material is reached for additional crystallization shots. Provided that the irradiation source has the ability to provide sufficient power to fully utilize the entire mask, throughput may not be adversely affected by adding additional 2-shot processes.
Referring now to FIG. 12 , which shows a view of adjacent beamlets taken from the first and second array of beamlets. Each beamlet has a width (W), a gap (g) and an overlap (S). The gap (g) is between adjacent elements is preferably designed to be the width (W) minus two times the overlap (S). The breadth (d) of the beamlets in the first and second arrays of beamlets should be greater than the step size between irradiation pulses. Although, there is no required upper limit on the breadth, the breadth is preferably only slightly greater than the step sizes between irradiation pulses to minimize the amount of overlap from one irradiation pulse to the next.
Referring again to FIG. 1 , in this illustrated embodiment, the size of the steps between irradiation pulses is constrained by the distance across of the third array of beamlets 22 and the distance across the forth array of beamlets 24 , which preferably have the same number of elements. In a preferred example, the step size would correspond to the number of elements in the array times the combination of the width of each element (W) and the gap (g) between adjacent beamlets. There is a gap 60 between the third array of beamlets 22 and the forth array of beamlets 24 . The distance across this gap is preferably the sum of the width (W), plus the gap (g), minus the overlap (S), which reduces to 2W−3S, since the gap (g) is related to W and S as described above. The space between the first array of beamlets 16 and the second array of beamlets 18 is not critical. The space between the third array of beamlets 22 and the second array of beamlets 18 is also not critical.
For purposes of illustration, the width (W) may be on the order of between approximately 3 and 5 micrometers. The overlap (S) may be on the order of between approximately 0.25 and 1 micrometer.
Referring again to FIG. 11 , the mask design can be extended for use in connection with any arbitrary number of 2-shot scans, such as 2+2+2, 2+2+2+2, etc. FIG. 11 shows one possible embodiment of a 2+2+2+2 mask design. Based upon the relationships described above one of ordinary skill in the art will be able to determine the necessary spacing of elements.
Referring now to FIG. 13 , in alternative embodiment the first array of beamlets 116 and the third array of beamlets 118 are designed to overlap slightly to crystallize crystallize material in one direction. While, the second array of beamlets 122 and the forth array of beamlets 124 irradiate at a second angle, preferably 90 degrees, relative to the first and third array of beamlets. Preferably the spacing will be optimized so that with the proper stepping distance the second array of beamlets 122 and the forth array of beamlets 124 will slightly overlap. This is just one exemplary embodiment to illustrate that the present invention is not limited to a single disclosed embodiment.
Rather, the scope of the invention will be determined by the broadest allowable interpretation of the following claims. | A mask design for use in sequential lateral solidification processing is provided comprising a first array of beamlet and a second array of beamlets, which is parallel to the first, for accomplishing a first 2-shot process, and a third array of beamlets and forth array of beamlets, both at at an angle, for example 90 degrees, relative to the first and second array of beamlets for accomplishing a second 2-shot process without the need to rotate the mask. A method of using the mask to accomplish a 2N crystallization process. | 1 |
CROSS-REFREENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part (CIP) of U.S. patent application Ser. No. 10/017,050, filed Dec. 13, 2001, entitled “IOTA SOFTWARE DOWNLOAD VIA AUXILIARY DEVICE”, which claims the benefit of U.S. Provisional Application Serial No. 60/310,511 filed Aug. 6, 2001. The disclosure of related patent application Ser. No. 10/017,050 is hereby incorporated by reference into the present disclosure as if fully set forth herein.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention is directed, in general, to Internet over-the-air software downloads to wireless communication devices and, more specifically, to wireless software download notification for wireless communication devices capable of accessing the Internet.
BACKGROUND OF THE INVENTION
[0003] As wireless communication devices such as mobile telephones and personal digital assistants (PDAs) become increasingly prevalent, the need for software downloads to such devices (e.g., to upgrade operating system software, update applications, or add after-market functionality) will also increase. Wireless communication devices capable of accessing the Internet (sometimes referred to as Internet over-the-air or “IOTA”) are particularly likely to require such software downloads. Wireless software downloads would be preferable in such cases to avoid the necessity of providing a separate Internet connection mechanism simply for software downloads.
[0004] Wireless performance of software downloads to wireless Internet-access devices is currently the subject of considerable effort, but standardization of such wireless downloads is challenging due to the wide disparity in technology employed by wireless devices. Wireless software downloads may be achieved by a variety of means including file transfer protocol (FTP), trivial file transfer protocol (TFTP), and the like. However, all of these methods require running the entire network protocol stack—including the radio frequency (RF), call processing, and transmission control protocol/Internet protocol (TCP/IP) layers—on the wireless communication device in order to download new software.
[0005] Currently, a user of a wireless communication device is required to poll a predefined website designated by the operator or manufacture to find out if any new software updates are available. However, this presents a problem with regard to the certainty that the user is aware of all software updates in a timely manner and that all users have applied critical software updates.
[0006] There is, therefore, a need in the art for providing a system and method for Internet over-the-air software download notification. In particular, there is a need for automatic notification of wireless communication devices capable of wireless connection to the Internet.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to overcome the above-discussed deficiencies of the prior art, and more specifically, it is a primary object of the present invention to provide a system and method for Internet over-the-air software download notification for wireless communication devices.
[0008] It is another object of the present invention to provide a wireless communication device capable of being upgraded from a software upgrade server via a wireless communication network. According to an advantageous embodiment of the present invention, the wireless communication device comprises: 1) a memory capable of storing a user profile, wherein the user profile is suitable for managing an un-attended software download; and 2) a message processor associated with the memory capable of communicating with the software upgrade server via the wireless communication network, wherein the message processor receives at least a first un-attended notification message from the software upgrade server identifying a new software update to be applied to the wireless communication device.
[0009] It is still another object of the present invention to provide a communication system capable of upgrading a wireless communication device from a software upgrade server via a wireless communication network. According to an advantageous embodiment of the present invention, the communication system comprises a wireless communication device capable of being upgraded from a software upgrade server via a wireless communication network comprising: 1) a memory capable of storing a user profile, wherein the user profile is suitable for managing an un-attended software download; and 2) a message processor associated with the memory capable of communicating with the software upgrade server via the wireless communication network, wherein the message processor receives at least a first un-attended notification message from the software upgrade server identifying a new software update to be applied to the wireless communication device.
[0010] These and other advantages and features of the present invention will become readily apparent to those skilled in the art upon examination of the subsequent detailed description and accompanying drawings. Accordingly, additional advantages and features of the present invention and the scope thereof are pointed out with particularity in the claims and form a part hereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A more complete understanding of the present invention, its preferred embodiments, further objects, and advantages thereof, will become more apparent by reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numbers indicate like elements, and in which:
[0012] [0012]FIG. 1 illustrates selected portions of an exemplary communication system according to one embodiment of the present invention; and
[0013] [0013]FIG. 2 illustrates a high-level flow diagram of a process for Internet over-the-air software download notification for a wireless communication device, according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Reference will now be made to the following detailed description of the exemplary embodiments of the present invention. Those skilled in the art will recognize that the present invention provides many inventive concepts and novel features that are merely illustrative and are not to be construed as restrictive. Accordingly, the specific embodiments discussed herein are given by way of example and should not be construed to limit the scope of the present invention.
[0015] [0015]FIG. 1 illustrates selected portions of an exemplary communication system 100 according to one embodiment of the present invention. Communication system 100 comprises a wireless communication network 101 coupling a wireless communication device 102 to Internet 103 and software update server 107 . Wireless communication network 101 also comprises mobile switching center (MSC) 104 , inter-working function (IWF) 105 , packet data protocol (PDP) access point (AP) 106 , and base stations (BS) 108 and 109 .
[0016] Radio frequency (RF) communication links 110 and 111 provide the operable connection between base stations (BS) 108 and 109 and wireless communication device 102 . Wireless communication device 102 may be any wireless communication device, including, but not limited to, conventional cellular telephones, paging devices, personal digital assistant devices, text-message transmission devices, portable computers, or the like.
[0017] Wireless connectivity between the wireless communication device 102 and the Internet 103 is provided by wireless communication network 101 through, for example, a mobile switching center (MSC) 104 and inter-working function (IWF) 105 , or through a packet data protocol (PDP) access point (AP) 106 for a general packet radio service (GPRS) gateway GPRS support node (GGSN).
[0018] Those skilled in the art will recognize that the complete structure and operation of a wireless communication network and other components within communication system 100 are not depicted or described. The present invention may be employed in conjunction with known wireless communication networks and other components, and only so much of those components as is unique to the present invention or necessary for an understanding of the present invention are depicted and described.
[0019] In order to receive wireless software download notifications, wireless communication device 102 employs the wireless connection to Internet 103 provided by wireless communication network 101 to access software update server 107 . Software update server 107 contains software to be downloaded to and installed within wireless communication device 102 for either replacing or augmenting existing software.
[0020] According to the principles of the present invention, wireless communication device 102 comprises a memory (not shown), message processor (not shown) and custom software to manage the entire procedure for the un-attended reception, software download, and installation of software described below. The message processor further allows, for example, software registration, security and encryption keys associated with wireless communication device 102 to be employed in downloading the software without transfer of such keys to any intermediate devices.
[0021] According to an advantageous embodiment of the present invention, the wireless software download notification is initiated when new software becomes available. In such an embodiment, software update server 107 sends out a special-purpose broadcast notification message via wireless communication network 101 to all wireless communication devices to which the software update applies. The special-purpose, specially-formatted broadcast message may be delivered to wireless communication device 102 using a variety of means, including short message service (SMS), multimedia messaging (MMS), email, special data burst messages, broadcast information on shared channels, or the like. In this advantageous embodiment, the specially formatted broadcast message contains at least one record, furthermore, each record may comprise a file name, file size, checksum, flag indicating if this is a mandatory software module, recommended download server (for geographical load balancing), or the like.
[0022] Accordingly, wireless communication device 102 receives the un-attended specially formulated broadcast message and the message processor checks the user-preferences stored in memory for the appropriate downloading profile. Depending on the content of the message, and the available battery life, wireless communication device 102 may begin downloading the software-update asynchronously. Alternatively, the user-preferences may require a user consultation prior to the downloading or loading of the software. Therefore, wireless communication device 102 may process the specially formatted message and prompt the user via the MMI for processing instructions.
[0023] Once the software is downloaded in its entirety, the message processor determines the appropriate time for wireless communication device 102 to enter a program mode. During the program mode, the wireless communication device 102 no longer communicates with wireless network 101 (i.e., wireless communication device 102 goes “off the air”). Wireless communication device 102 proceeds to program the buffered software update, installing the downloaded software for either replacing or augmenting the existing software. Once the programming and installation is complete, if needed, wireless communication device 102 restarts or “reboots” in order to effectively utilize the newly loaded software.
[0024] [0024]FIG. 2 illustrates a high-level flow diagram of a process for Internet over-the-air software download notification for a wireless communication device, according to one embodiment of the present invention. The process 200 begins with a wireless software download to a wireless communication device capable of Internet access (process step 205 ). In order to receive wireless software download notifications, wireless communication device 102 connects to Internet 103 provided by wireless communication network 101 to access software update server 107 (process step 210 ).
[0025] When new software becomes available, software update server 107 sends out a specially formatted, specific-purpose broadcast message to all wireless communication devices to which the software update applies, via wireless communication network 101 (process step 215 ). Wireless communication device 102 receives the un-attended specially formatted broadcast message from software update server 107 (process step 220 ). The message processor of wireless communication device 102 checks the user-preferences for the appropriate downloading profile (process step 225 ).
[0026] Depending on the content of the message and the available battery life, wireless communication device 102 may begin downloading the software-update or may initiate a consultation with the user prior to the downloading or loading of the software. Thereinafter, the software update from software update server 107 is downloaded to wireless communication device 102 , via wireless communication network 101 (process step 230 ). Alternatively, wireless communication device 102 enters into a delay loop (process step 231 ) wherein the downloading of the software-update is not initiated until such time as indicated by the downloading profile.
[0027] Thereafter, wireless communication device 102 enters a program mode, in which the wireless communication device 102 no longer communicates with wireless network 101 (process step 235 ). Wireless communication device 102 proceeds to program the buffered software update, installing the downloaded software for either replacing or augmenting of existing software (process step 240 ). If necessary, once the programming and installation is complete, wireless communication device 102 restarts or “reboots” in order to effectively utilize the newly loaded software (process step 245 ).
[0028] While the exemplary embodiments of the present invention have been shown and described, it will be understood that various changes and modifications to the foregoing embodiments may become apparent to those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the invention is not limited to the embodiments disclosed, but rather by the appended claims and their equivalents. | A wireless communication device capable of being upgraded from a software upgrade server via a wireless communication network. The wireless communication device comprises: 1) a memory capable of storing a user profile, wherein the user profile is suitable for managing an un-attended software download; and 2) a message processor associated with the memory capable of communicating with the software upgrade server via the wireless communication network, wherein the message processor receives at least a first un-attended notification message from the software upgrade server identifying a new software update to be applied to the wireless communication device. | 7 |
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2011/003083, filed on Jun. 22, 2011, which claims the benefit of priority to Serial No. DE 10 2010 032 057.9, filed on Jul. 23, 2010 in Germany, the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND
The disclosure relates to a radial piston machine as per the description below and to a piston suitable for a radial piston machine.
A radial piston machine of said type and a piston of said type are known for example from DE 39 19 456 C2. Said document discloses a radial piston machine having a stroke ring which is fixed with respect to a housing and which may for example be arranged with a cam path or eccentrically with respect to a rotatably mounted cylinder star. In the cylinder star, a multiplicity of pistons is guided so as to be displaceable in the radial direction, said pistons being supported on the stroke ring in each case by means of a roller. In the known solutions, said roller is rotatably mounted on the piston foot via a bearing shell, wherein captive retention of the piston is realized by virtue of the fact that the piston foot extends around the roller over more than 180°, such that the roller is secured in the radial direction. A problem of said solution is that considerable outlay is required for the machining of the piston foot, because the embracing configuration of the piston foot cannot be realized by means of simple grinding, but rather must be formed by means of transverse milling or stamping. Such production methods are relatively imprecise, such that a precise bearing shell fit in the piston foot cannot be ensured. In the worst case, bearing shell fracture may occur.
A similar embodiment of a piston foot is also disclosed in DE 39 26 185 C2. In said variant, too, the roller 1 is secured by an embracing form of the piston foot.
US 2009/0183629 A1 presents a piston in which the embracing form is realized not by means of a cutting-type machining process but rather by means of a crimping process. In one variant, in said known piston arrangement, the bearing shell also extends around the roller over more than 180°—all of said solutions however require that the piston foot be of crimpable configuration. As a result of the required crimping, the production outlay is likewise considerable, wherein a crimped securing arrangement necessitates the provision of a suitable piston material, such that there are certain restrictions with regard to material selection.
By contrast, it is the object of the disclosure to provide a radial piston machine and a piston which is suitable for such a radial piston machine, in which a roller is captively retained in a simple manner.
Said object is achieved, with regard to the radial piston machine, by means of the features described below, and with regard to the piston, by means of the features of the coordinate description below.
The description below relates to advantageous refinements of the disclosure.
SUMMARY
The radial piston machine according to the disclosure has a stroke ring which is fixed with respect to a housing and on the stroke path of which a multiplicity of pistons which are movable in a rotatably mounted cylinder star are supported via in each case one roller. Each roller is rotatably mounted on a piston foot via a bearing shell. According to the disclosure, the captive retention means is formed substantially by the bearing shell. That means that, according to the disclosure, the function of captive retention is reassigned from the piston, which is difficult to machine, to the bearing shell which, as a relatively areal component, is significantly easier to machine.
In one variant of the disclosure, the bearing shell extends around the roller over a circumferential angle of greater than 180°—in other words, the bearing shell embraces the roller such that the latter is secured in the radial direction.
In said variant, it is preferable for a receptacle in the piston foot for the bearing shell to extend around the roller over a maximum of 180°—that is to say the piston foot is not designed with an embracing form, such that the bearing shell receptacle can be produced in a very simple manner, for example by means of plunge-cut grinding. As a result of said simple machining, it is possible for the bearing shell receptacle to be produced very precisely, such that bearing shell fracture as a result of incorrect support is virtually ruled out.
In a preferred exemplary embodiment of the disclosure, the bearing shell is connected to the piston foot by adhesive bonding or by means of a rivet.
It has proven to be a particularly simple solution for the rivet to be formed as a blind rivet.
The fixing of the bearing shell in position in the piston foot is particularly reliable if said bearing shell is fastened to the piston foot by adhesive bonding and by riveting.
To minimize the friction and wear in the region of the roller bearing arrangement, the rivet may be formed with a duct for the supply of fluid to the bearing region.
Said supply of fluid may take place via a piston bore which has a pressure medium connection to the duct of the rivet.
To further minimize the friction, a hydrostatic field may be formed in the bearing shell, to which hydrostatic field pressure medium is supplied via the duct.
The piston according to the disclosure is accordingly formed with a bearing shell whose geometry is selected such that it also acts as a captive retention means for a roller.
It is preferable if the bearing shell embraces the roller, that is to say extends around at least one portion of the roller over more than 180°.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred exemplary embodiments of the disclosure will be explained in more detail below on the basis of schematic drawings, in which:
FIG. 1 shows a section through an axial piston machine;
FIG. 2 shows views of a first exemplary embodiment of a piston for a radial piston machine of said type;
FIG. 3 shows views of a further exemplary embodiment of a radial piston machine, and
FIG. 4 shows a hydrostatic field for minimizing friction for the pistons as per FIGS. 2 and 3 .
DETAILED DESCRIPTION
FIG. 1 shows a diagonal section through a radial piston pump, wherein for simplicity, owing to the symmetrical construction, only one half of the section is illustrated. A radial piston pump of said type has a stroke ring 2 which is mounted in a housing—not shown—and whose inner circumferential surface is formed as a cam path 4 . Within the stroke ring 2 there is mounted a cylinder star 8 which is connected rotationally conjointly to a pump shaft 6 and in which are formed a multiplicity of cylinder bores 10 extending in the radial direction. In each cylinder bore 10 , a piston 12 is guided so as to be displaceable in the radial direction of the cylinder star 8 . Said piston 12 delimits, together with the cylinder bore 10 , a working chamber 14 , the volume of which is defined by the piston stroke. Said working chamber 14 can be connected via a pressure medium duct 16 and via inlet and outlet valves (not illustrated) to a tank or to a pressure port, such that during an expansion stroke of the piston 12 , pressure medium is delivered into the working chamber 14 , and during a compression stroke, pressure medium is delivered out of the working chamber 14 to the pressure port.
Each piston has a piston foot 18 in which is rotatably mounted a cylindrical roller 20 which rolls along the cam path 4 as the cylinder star 8 rotates. In the illustrated exemplary embodiment, said cam path is of undulating design, such that each piston 12 performs multiple piston strokes during one revolution. It is self-evidently also possible for some other geometry to be used instead of such an undulating cam path 4 . In principle, the concept according to the disclosure is also applicable to a radial piston pump with an eccentric drive, in which the pump shaft axis and the stroke ring axis are offset.
The roller 20 is received in the piston foot 18 via a bearing shell 22 . By contrast to the prior art, the captive retention of the roller 20 is realized not by means of an embracing form of the piston foot 18 but rather by means of the bearing shell 22 . This will be explained on the basis of the individual illustrations of a piston in FIGS. 2 and 3 .
FIG. 2 a shows a three-dimensional, highly schematic illustration of a single piston 12 of the radial piston machine 1 from FIG. 1 . According to said figure, the piston 12 is of substantially cylindrical form and bears, at its working-chamber-side end portion, a sealing ring 23 which is inserted into an annular groove (see FIG. 1 ), by means of which sealing ring the working chamber 14 is sealed off radially to the outside. Into the piston foot 18 , which is situated at the top in FIG. 2 , there is formed a cylinder-segment-shaped indentation 24 which is particularly clearly visible in the illustration of FIG. 2 b . The bearing shell 22 is inserted into said indentation 24 .
As emerges particularly clearly from FIG. 2 , the indentation 24 is formed such that the roller 20 which is inserted into the bearing shell 22 is extended around over a circumferential angle α of at most 180°. In the specific exemplary embodiment, the indentation 24 is, in the view of FIG. 2 , formed as a semicircle—that is to say the circumferential angle is 180°.
In FIGS. 2 a and 2 b , the bearing shell 22 embraces the outer circumference of the roller 20 , that is to say the circumferential angle β (dashed line in FIG. 2 b ) over which the bearing shell 22 extends is greater than 180°. The roller 20 is thus received in the bearing shell 22 in a positively locking manner in the radial direction and is thus fixed in position. The fit is however formed such that the roller 20 can rotate with relatively low friction. With the solution according to the disclosure, therefore, the function of captive retention is reassigned to the bearing shell side, whereas the piston foot 18 is of relatively simple form and can thus be machined in a simple manner as described in the introduction. The piston can thus be formed in a very simple manner, for example by means of plunge-cut grinding or similar methods, or alternatively by sintering, such that a precise receptacle is created for the bearing shell 22 .
In the exemplary embodiment illustrated, the bearing shell 22 is adhesively bonded into the indentation 24 , wherein the areal fit, which is formed with high accuracy, permits a high-strength adhesive bond. The insertion of the roller 20 into the bearing shell 22 can take place in a simple manner in the axial direction.
FIG. 3 shows a refinement of the exemplary embodiment according to FIG. 2 . The embodiment of the bearing shell 22 , of the roller 20 and of the piston 12 corresponds substantially to the exemplary embodiment described above, such that explanations in this regard can, by reference to the embodiments above, be omitted. In addition to the adhesive bonding of the bearing shell 22 to the piston foot 18 , the bearing shell 22 is fixed in position by means of a rivet 26 . Said rivet may be formed for example as a blind rivet and has a passage bore 28 which opens out at one side in the chamber around which the bearing shell 22 extends and at the outer side in an axial bore 30 of the piston 12 . Said axial bore 30 has a pressure medium connection to the pressure side of the radial piston pump, such that pressure medium is supplied to the bearing receptacle via the axial bore 30 and the passage bore 28 and the friction is thus reduced. Accordingly, said rivet 26 performs a dual function—it serves firstly for fastening the bearing shell 22 in the piston foot 18 , and it secondly forms a part of a lubricating oil flow path for minimizing the friction of the roller 20 .
As already indicated above, it is preferable for the bearing shell 22 to be connected to the piston foot 18 by adhesive bonding and by riveting. It is self-evidently alternatively also possible for one of said variants or for some other fastening solution to be selected. As can be seen in the detail illustration, the rivet head is formed flush with the inner circumferential wall of the bearing shell 22 or is recessed, such that an optimum sliding surface for the roller 20 is provided.
To improve the bearing arrangement, a hydrostatic field may be formed in the bearing shell 22 . FIG. 4 shows such a variant, wherein the view according to FIG. 4 is a view into the bearing shell 22 in the axial direction of the piston 12 . It is possible to see the mouth region of the passage bore 28 . In the exemplary embodiment according to FIG. 3 , said passage bore 28 is formed in the rivet 26 (dashed line in FIG. 4 ); said passage bore 28 may self-evidently also be formed directly in the bearing shell 22 . The mouth region of the passage bore 28 is connected via a radial groove 32 to an encircling, frame-shaped channel 34 which is formed for example by milling or the like. Instead of the rectangular geometry of the encircling channel 34 , it is self-evidently also possible to select some other geometry suitable for a hydrostatic bearing arrangement. The production of said hydrostatic field 36 is particularly simple if it is formed before the bending of the bearing shell 22 . After production of the hydrostatic field 36 by milling or some other process, the planar bearing shell blank 22 is then bent into the desired cylindrical shell shape. It is self-evidently also possible for the bearing shell 22 to be produced by sintering or the like and, in this case, for the hydrostatic field 36 to be formed in one working step.
If the rivet 26 is to be used, the passage bore 28 indicated in FIG. 4 may also be formed initially as a bore in the bearing shell 22 , into which bore the rivet 26 is then inserted. With regard to function, there is then correspondence with the exemplary embodiment described above.
Disclosed is a radial piston machine having a piston which bears, on its piston foot, a roller. The captive retention means for said roller is formed by a bearing shell which is inserted into the piston foot. | A radial piston machine includes a piston having a base which is provided with a roller. The roller is held secure by a bearing shell that is inserted in the piston base. | 5 |
RELATED APPLICATIONS
U.S. Application No. 61/926,832 for this invention was filed on Jan. 13, 2014, for which application these inventors claim domestic priority, and which application is incorporated in its entirety.
BACKGROUND OF THE INVENTION
The present invention generally relates to artificial lift systems which are utilized for production of fluids from subsurface reservoirs, including oil, water, and liquid phase hydrocarbons. More particularly, the present invention is utilized with artificial lift systems where a subsurface pump is actuated by a plurality of rods connected end-to-end, herein collectively referred to as a “rod string.” The rod string is set within a plurality of tubing joints likewise connected end-to-end, wherein the tubing joints are collectively referred to as a “tubing string.” Actuation of the subsurface pump lifts the fluid upwardly from the subsurface pump to the surface, where the fluids flow in the annular space between the rod string and the inside diameter of the tubing string as the fluid flows upwardly.
The typical subsurface pump operated by a rod string is a positive displacement pump operated by reciprocation of the rod string. This type of pump has a plunger connected to the rod string, where the plunger reciprocates within a polished barrel located at the bottom of the tubing string such that liquids are drawn into the pump barrel and lifted upwardly through the tubing string. The reciprocating motion of the rod string is typically imparted by a pump jack.
For this system, the uppermost rod in the rod string is a polish rod. The polish rod reciprocates in and out of a stuffing box. The stuffing box is a close-fit assembly which cleans the polished rod, prevents debris from entering or exiting the well, and further prevents fluid from leaking from the well during operation. The stuffing box is typically mounted above a T-fitting or pumping tee cross at the top of the tubing. The stuffing box provides a dynamic seal along the length of the polish rod. The stuffing box typically has a central passage through which the polish rod moves, while stuffing or packing material is compressed against the sides of the polish rod to create a fluid seal. The packing materials are typically elastomers and other materials which are softer than the polish rod material.
The movement of the polish rod within the packing material generates friction, and thus heat, which breaks down and degrades the packing materials contained within the stuffing box. This breakdown and degradation reduces the integrity of the seal formed between the packing material and the polish rod. The presence of solids in the produced fluid, such as sand, can accelerate this degrading of the packing material and can adversely impact the life of the polish rod, potentially resulting in a polish rod failure. The loss of the integrity of the seal between the polish rod and the packing material will result in the escape of fluids from the well which can result in environmental damage and the loss of valuable resources, and can result in significant clean-up expense and potential fines and penalties. Accelerated packing replacement also requires the expenditure of man-hours to replace the packing which might otherwise be avoided.
Solutions to the above problem typically focus on the packing material, such as utilizing a different type of packing material or attempting to reduce the friction between the polish rod and the packing material, and therefore reduce the thermal degradation.
SUMMARY OF THE INVENTION
Embodiments of the presently disclosed invention provides a solution to the problems identified above by addressing the problem by guiding and aligning the polish rod as it reciprocates within the stuffing box thereby reducing lateral motion of the polish rod. Embodiments of the invention may also wipe the polish rod of debris as it reciprocates within the device. In one embodiment of the invention, a coupling member, hereinafter referred to as the “centralizer” has threads on one end into which the threads of a pin end of the stuffing box are made up. The centralizer has a second end to which an alignment barrel depends, either by direct connection or by utilization of a barrel adapter. In a first embodiment of the invention, as the stuffing box is attached to the centralizer, the stuffing box is slid over a nylon sleeve through which the polish rod is inserted. In a second embodiment of the invention, the stuffing box is made up to the centralizer and the nylon sleeve is captured on the bottom side of the centralizer by the barrel adapter. In both embodiments, an alignment barrel depends from the centralizer, either by direct connection to the centralizer or by utilization of the barrel adapter, which makes up into the bottom of the centralizer.
The polish rod reciprocates within the alignment barrel and the nylon sleeve. The alignment barrel may comprise slots to allow for the passage of oil, scale and solids which may accumulate on the polish rod. The alignment barrel has an inside diameter which is smaller than the outside diameter of the coupling which attaches the polish rod to the top rod of the rod string, such that should the alignment barrel become detached from the centralizer, the alignment barrel can fall through the tubing no further than down to the connection between the polish rod and the top rod of the rod string.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a pump jack, polish rod, and stuffing box, to which embodiments of the present invention may be utilized.
FIG. 2 shows a perspective view of an embodiment of the polish rod alignment device with a stuffing box attached.
FIG. 2A shows a detailed view of the stuffing box attached to the preserver barrel coupling.
FIG. 2B shows a detailed view of the polish rod and preserver barrel extending through a pumping tee fitting.
FIG. 3 shows a perspective view of an embodiment of the polish rod alignment device.
FIG. 3A shows a front view of an embodiment of the polish rod alignment device.
FIG. 3B shows a sectional view taken along line A-A of FIG. 3A .
FIG. 3C shows a close-up view of circled portion of FIG. 3B .
FIG. 4 shows a perspective view of an embodiment of an alignment barrel which may be utilized in embodiments of the polish rod alignment device.
FIG. 4A shows a front view of an embodiment of an alignment barrel.
FIG. 4B shows a sectional view taken along line A-A of FIG. 4A .
FIG. 4C shows a close up view of the circled portion of FIG. 4B . Illustrative dimensions are provided for one embodiment of the invention.
FIG. 5 shows a perspective view of an embodiment of a nylon sleeve which may be utilized in embodiments of the polish rod alignment device. Illustrative dimensions are provided for one embodiment of the invention.
FIG. 5A shows a front view of an embodiment of the nylon sleeve.
FIG. 5B shows a sectional view taken along line A-A of FIG. 5A . Illustrative dimensions are provided for one embodiment of the invention.
FIG. 6 is a perspective view of an embodiment of a coupling, i.e., centralizer, which may be utilized in embodiments of the polish rod alignment device.
FIG. 6A shows a front view of an embodiment of a centralizer.
FIG. 6B shows a sectional view taken along line A-B of FIG. 6A .
FIG. 7 shows an exploded and sectional view of an alternative embodiment of the polish rod alignment and stabilization device
FIG. 8 shows a perspective view of a centralizer which may be used with the alternative embodiment.
FIG. 9 shows a sectioned view of the centralizer of depicted in FIG. 8 .
FIG. 10 shows a top view of the centralizer depicted in FIG. 8 .
FIG. 11 shows a bottom view of the centralizer depicted in FIG. 8 .
FIG. 12 shows a perspective view of a nylon sleeve which may be used with the alternative embodiment of the invention.
FIG. 13 shows a top perspective view of the nylon sleeve depicted in FIG. 12 .
FIG. 14 shows a bottom perspective view of the nylon sleeve depicted in FIG. 12 .
FIG. 15 shows a perspective view of a barrel adapter which may be used with the alternative embodiment of the invention.
FIG. 16 shows a sectioned view of the barrel adapter depicted in FIG. 15 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
Referring now to the figures, FIG. 1 shows a known pumping unit 10 which is utilized to impart a reciprocating motion to a rod string 16 . The rod string terminates at the surface with a polish rod 12 . As shown in greater detail in FIGS. 2, 2A and 2B , polish rod 12 reciprocates or rotates within stuffing box 14 which contains internal seal packing elements 26 for maintaining a pressure seal around the polish rod 12 . Referring again to FIG. 1 , rod string 16 reciprocates within a tubing string 18 . A subsurface pump 20 is actuated by the reciprocal motion of the rod string 16 resulting in fluid flow from the reservoir up through the tubing string 18 and out production line 22 which is typically connected to an outlet of a pumping tee 24 .
Stuffing box 14 maintains a seal between the polish rod 12 and the tubing string 18 . An embodiment of an apparatus for maintaining the alignment of the polish rod with respect to the stuffing box 14 , referred to hereinafter as the alignment device 100 , forms an extended chamber for travel of the polish rod 12 .
FIG. 1 schematically depicts one location in which the alignment device 100 may be mounted, where the centralizer 130 is depicted connected to the stuffing box 14 . It is to be appreciated that most of the disclosed apparatus is not shown in FIG. 1 , because, for this particular embodiment of the alignment device 100 , with the exception of the centralizer 130 , most of the device is contained within the pumping tee 24 and the top joint of the tubing string 18 , and/or any pup joints between the pumping tee and the top joint. Embodiments of the present invention thus provide a guidance mechanism for the polish rod 12 which is almost entirely contained within the upper portion of the tubing string 18 .
An embodiment of the alignment device 100 is generally depicted in FIGS. 2, 2A and 2B . In general, the alignment device 100 has an alignment barrel 110 , an alignment sleeve 120 , and a centralizer 130 to which the stuffing box 14 is attached. As shown in the Figures, the alignment device 100 may be configured with the centralizer 130 mounted at the top of the alignment barrel 110 , with the alignment sleeve 120 disposed within the centralizer 130 . For purposes of this disclosure, the terms “top,” “bottom,” “upper,” “lower,” “above,” and “beneath” are made with reference to the ground surface, with items referred as top, upper, and above located at a higher relative position with respect to the ground surface than items referred to as bottom, lower, and beneath. For the embodiment of the alignment device 100 shown in FIGS. 2 and 2A , a pin or threaded end on the lower end of stuffing box 14 makes up into internal threads 132 in centralizer 130 .
As shown in greater detail in FIGS. 2 and 2B , in this embodiment of the invention, the alignment barrel 110 is suspended from centralizer 130 such as by making up external threads on alignment barrel up into internal threads in centralizer 130 , or by utilizing a hanger assembly on alignment barrel 110 which lands within a profile in centralizer 130 . Centralizer 130 is attached to pumping tee 24 with the lower threads 134 of the centralizer 130 typically making up into internal threads contained within the production tee 24 . The packing material 26 of the stuffing box 14 will typically be contained within a portion of the stuffing box 14 which is above the alignment sleeve 120 . With this configuration, the polish rod 12 is isolated from the internal pressure of the tubing string 18 by the packing contained 26 within the stuffing box 14 . In this embodiment of the alignment device 100 , alignment sleeve 120 , as shown in FIG. 2A , is vertically adjacent to the packing material 26 . Alignment sleeve 120 centralizes and guides the polish rod 12 as it is reciprocated up and down inside the packing material 26 .
For illustration purposes, in one embodiment of the invention, alignment sleeve 120 may have a length of approximately 3 inches and an inside diameter of approximately 1.5 inches, although the outside diameter of the alignment sleeve 120 is dependent upon the bottom inside diameter of the stuffing box or blow-out preventer into which upper edge 121 seats. The outside diameter of the alignment sleeve 120 must also fit into the top of the centralizer and mate to the designated face. For this reason, the alignment sleeve 120 may have a chamfered bottom edge 123 which seats within a corresponding chamfered portion of the centralizer 130 , such that the faces are aligned and mated within the centralizer. Alignment sleeve 120 may be fabricated from nylon.
Alignment barrel 110 , which may be fabricated from carbon steel or appropriate corrosion resistant materials and, in one embodiment, have an inside diameter of approximately 1.6 inches. The length L of alignment barrel 110 will be somewhat dependent upon the stroke length of the downhole pump 20 . However, alignment barrel 110 will generally have a length greater than one foot, and may be several feet in length or longer. Thus, support and guidance for the polish rod 12 is provided for a significant distance adjacent to the stuffing box 14 .
In most embodiments of the invention the outside diameter of the coupling which connects the top rod of rod string 16 to the bottom of polish rod 12 will be larger than the inside diameter of the alignment barrel 110 , so the pump must be spaced such that the coupling is not pulled up into the bottom of the alignment barrel. This feature prevents the alignment barrel 110 from falling to the bottom of the tubing string 18 should the alignment barrel become detached from the centralizer 130 , but rather the alignment barrel will be stopped by the coupling which connects the top rod of rod string 16 to the bottom of polish rod 12 , such that the alignment barrel is relatively easy to recover in such situations.
As shown in the figures, alignment barrel 110 has slots 112 penetrating through its side walls which allow liquids, as well as any scale, solids, etc., which are produced up through the tubing to exit the alignment barrel 110 . By way of example only, slots 112 may have a width of 0.625 inches and a length of approximately 3 inches and may be identical on either side of the barrel.
FIGS. 7 through 16 show an alternative embodiment of the alignment device 1000 . This embodiment utilizes the same alignment barrel 110 as the embodiment of the alignment device 100 discussed above. Stuffing box 14 will make up into threads 1132 of the centralizer 1130 . In the alternative embodiment of the alignment device 1000 , a barrel adapter 1200 is utilized to attach the alignment barrel 110 to the centralizer 1130 , where alignment sleeve 1120 is captured in the lower portion of centralizer 1130 by the engagement of threads 1210 of the barrel adapter 1200 to internal threads 1140 of the centralizer. Centralizer 1130 further comprises external threads 1134 at the bottom which make up into internal threads of the pumping tee 24 as before. Centralizer 1130 may further comprise a relief port 1150 .
FIGS. 12 through 14 depict an embodiment of an alignment sleeve 1120 which might be utilized with the alternative embodiment of the alignment device 1000 . The upper surface 1150 of alignment sleeve 1120 may be tapered to seal against an internal profile within the centralizer 1130 . The lower surface 1160 may seal against a matching surface 1220 in barrel adapter 1200 .
FIGS. 15 through 16 depict an embodiment of a barrel adapter 1200 which may be utilized to attach alignment barrel 110 to centralizer 1130 in an embodiment of the alignment device 1000 , such that alignment barrel 110 depends from centralizer 1130 , capturing alignment sleeve 1120 between the centralizer and the barrel adapter. Barrel adapter 1200 comprises external threads 1210 which make up into threads 1140 of the centralizer. Barrel adapter 1200 may further comprise threads 1230 which make up to threads 114 of alignment barrel 110 .
This embodiment of the alignment device 1000 allows manufacturing of a single centralizer body 1130 which may be utilized with three sizes of barrel adapter 1200 , such that embodiments of the device may accommodate three sizes of polish rod, specifically 1.25″, 1.50″, and 1.75″.
While the above is a description of various embodiments of the present invention, further modifications may be employed without departing from the spirit and scope of the present invention. Thus the scope of the invention should not be limited according to these factors, but according to the following appended claims. | A polish rod alignment and stabilization device preserves stuffing box packing and protects the polish rod of an oil well sucker rod string by guiding and aligning the polish rod as it reciprocates within the stuffing box thereby reducing lateral motion of the polish rod reciprocates up and down. Embodiments of the invention may also wipe the polish rod of debris as it reciprocates within the device. The alignment device utilizes a rod centralizer to which a stuffing box is made up. The centralizer has a second end to which an alignment barrel depends, either by direct connection or by utilization of a barrel adapter. The alignment barrel is disposed within the uppermost portion of the tubing string of the well. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to a minimally invasive surgical instrument having a detachable end effector.
BACKGROUND
[0002] Minimally invasive surgery is a surgical approach that involves the use of instruments inserted through several tiny incision openings to perform a surgery causing minimal tissue trauma in human or animal bodies.
[0003] The minimally invasive surgery relatively reduces changes in metabolism of a patient in the period of post-surgical care, so it facilitates rapid recovery of the patient. Therefore, the minimally invasive surgery shortens the length of hospitalization of the patient after the surgery and allows the patient to return to normal physical activities in a short period of time. In addition, the minimally invasive surgery causes less pain and leaves fewer scars on the patient's body after the surgery.
[0004] One of the general forms of the minimally invasive surgery is endoscopy. Among the others, a laparoscopy that involves minimally invasive inspection and operation inside abdominal cavity is known as the most general form of endoscopy. To operate a standard laparoscopic surgery, the abdomen of the patient is insufflated with gas and at least one small incision is formed to provide an entrance for laparoscopic surgical instruments, through which a trocar is inserted. When performing the surgery, it is general that a user puts the laparoscopic surgical instruments into a surgical site or the like through the trocar, and manipulates (or controls) the instruments from the outside of abdominal cavity. In general, the laparoscopic surgical instruments include a laparoscope (for observation of a surgical site) and other working tools. Herein, the working tools are similar to the conventional tools used for small incision surgery, except that the end effector or working end of each tool is separated from its handle or the like by a shaft. For instance, the working tools may include a clamp, a grasper, scissors, a stapler, a needle holder, and so forth. Meanwhile, the user monitors the procedure of the surgery through a monitor that displays the images of the surgical site which are taken by the laparoscope. The endoscopic approaches similar to the above are broadly used in retroperitoneoscopy, pelviscopy, arthroscopy, cisternoscopy, sinuscopy, hysteroscopy, nephroscopy, cystoscopy, urethroscopy, pyeloscopy, and so on.
[0005] The inventor(s) has developed various minimally invasive surgical instruments useful for the above-mentioned minimally invasive surgeries and has already disclosed the features of the structures and effects of the same in Korean Patent Application Nos. 2008-51248, 2008-61894, 2008-79126 and 2008-90560, the contents of which are incorporated herein by reference in its entirety. Additionally, the inventor(s) have also introduced a minimally invasive surgical instrument with improved functionality, which is more advantageous for users and patients, in Korean Patent Application Nos. 2010-115152, 2011-3192, 2011-26243 and 2011-29771, the contents of which are incorporated herein by reference in its entirety.
[0006] Herein, the inventor(s) now present a minimally invasive surgical instrument to and from which a user may easily attach and detach an end effector.
SUMMARY OF THE INVENTION
[0007] One object of the present invention is to provide a minimally invasive surgical instrument to and from which a user may easily attach and detach an end effector.
[0008] Another object of the invention is to provide a minimally invasive surgical instrument which may be more economically used by increasing the utility and reusability of the parts except the end effector thereof.
[0009] According to one aspect of the invention to achieve the objects as described above, there is provided a minimally invasive surgical instrument comprising a shaft; a joint unit being connected to one end of the shaft; and an end effector being connected to the joint unit and capable of carrying out joint motion thereby, wherein the joint unit comprises a detachable connecting unit being capable of receiving rotational torque, and wherein the end effector comprises a working end connecting unit being capable of being screwed into the detachable connecting unit to attach thereto or being screwed out of the detachable connecting unit to detach therefrom.
[0010] In addition, there may be provided other configurations to implement this invention.
[0011] According to the invention, there is provided a minimally invasive surgical instrument to and from which a user may easily attach and detach an end effector.
[0012] According to the invention, there is provided a minimally invasive surgical instrument which may be more economically used by increasing the utility and reusability of the parts except the end effector thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows the overall appearance of a minimally invasive surgical instrument according to one embodiment of the invention.
[0014] FIG. 2 is a perspective view of some components such as an end effector 200 and a joint unit 300 of a minimally invasive surgical instrument according to one embodiment of the invention.
[0015] FIG. 3 is an exploded perspective view of the components of the minimally invasive surgical instrument shown in FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] In the following detailed description of the invention, references are made to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention, although different from each other, are not necessarily mutually exclusive. For example, specific shapes, structures, or characteristics described herein may be implemented as modified from one embodiment to another embodiment without departing from the spirit and the scope of the invention. Furthermore, it shall be understood that the locations or arrangements of individual elements within each embodiment may be also modified without departing from the spirit and the scope of the invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the invention is to be taken as encompassing the scope of the appended claims and all equivalents thereof. In the drawings, like reference numerals refer to the same or similar elements throughout the several views.
[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings to enable those skilled in the art to easily implement the invention.
[0018] Meanwhile, it should be understood that the term “connection” herein encompasses a direct connection or an indirect connection (i.e., via separate components) between mechanical or other types of components.
[0019] FIG. 1 shows the overall appearance of a minimally invasive surgical instrument according to one embodiment of the invention.
[0020] Reference will be made to FIG. 1 . The minimally invasive surgical instrument may comprise a shaft 100 ; an end effector 200 being connected to one end of the shaft 100 to perform surgery by using surgical tools (not shown) or functioning itself as a surgical tool; a joint unit 300 to connect the shaft 100 and the end effector 200 and to provide the end effector 200 with joint functionality; and a handling unit 400 being connected to the other end of the shaft 100 and capable of being held and manipulated by a user.
[0021] First, the shaft 100 may include a cavity therein to support and pass at least one wire or torque transmission member, in the same manner as those of the minimally invasive surgical instruments disclosed in the aforementioned Korean patent applications. (The torque transmission member is mainly intended for the rolling motion of the end effector 200 , while the shaft 100 may function itself as the torque transmission member in some cases.) The shaft 100 may comprise at least one segment as necessary. Further, the shaft 100 may comprise a bend in at least a part thereof.
[0022] Next, the end effector 200 may carry out joint motion, rolling motion, opening/closing motion and the like by the action of the at least one wire or torque transmission member passing from the handling unit 400 to the joint unit 300 via the shaft 100 , in the same manner as those of the minimally invasive surgical instruments disclosed in the aforementioned Korean patent applications. The tip of the end effector 200 may be implemented in the form of a clamp, a grasper, a pair of scissors, a stapler, a needle holder, a hook-type electrode or the like.
[0023] Next, the joint unit 300 may act together with the at least one wire or torque transmission member to allow the end effector 200 to carry out joint motion, rolling motion and the like, in the same manner as those of the minimally invasive surgical instruments disclosed in the aforementioned Korean patent applications.
[0024] Finally, the handling unit 400 may control the joint motion, rolling motion, opening/closing motion and the like of the end effector 200 according to the user's manipulation, in the same manner as those of the minimally invasive surgical instruments disclosed in the aforementioned Korean patent applications. To allow for such control, the at least one wire or torque transmission member may be connected to the handling unit 400 .
[0025] FIG. 2 is a perspective view of some components such as the end effector 200 and the joint unit 300 of the minimally invasive surgical instrument according to one embodiment of the invention. Further, FIG. 3 is an exploded perspective view of the components of the minimally invasive surgical instrument shown in FIG. 2 .
[0026] Reference will be made to FIG. 2 . As described above, the end effector 200 and the joint unit 300 may be connected to each other, and a torque transmission member 500 or an opening/closing wire 600 may be supported and passed through some part of the joint unit 300 (preferably the longitudinal central axis thereof) toward the end effector 200 . In connection with the configuration of the joint unit 300 , the torque transmission member 500 and the opening/closing wire 600 , further reference may be made to Korean Patent Application Nos. 2011-86738 and 2011-89854, the contents of which are incorporated herein by reference in its entirety.
[0027] Reference will be made to FIG. 3 .
[0028] First, the end effector 200 may essentially comprise a working end 210 (shown in FIG. 2 ), a working end connecting unit 220 and an X-shaped link 230 . The configuration and operating principle of the end effector 200 may be similar to those of the end effectors disclosed in the aforementioned Korean patent applications.
[0029] Further, the end effector 200 may further comprise an opening/closing wire fixing unit 240 and a fixing ring 250 .
[0030] Since the opening/closing wire fixing unit 240 may be connected with the X-shaped link 230 and also with an opening/closing wire cap 320 to be described below, it may pull the X-shaped link 230 to close the working end 210 as the opening/closing wire 600 is pulled. In connection with this, it should be noted that those skilled in the art may also employ an alternative configuration in which the working end 210 is opened as the opening/closing wire 600 is pulled, or in which the working end 210 is closed or opened by means of a component that may apply a pushing force in place of the opening/closing wire 600 .
[0031] The fixing ring 250 may be made of an elastic material or other materials, and used to wind the opening/closing wire fixing unit 240 and the opening/closing wire cap 320 together to connect and fix them to each other.
[0032] The components of the end effector 200 will be further discussed when those of the joint unit 300 are described below.
[0033] The configuration and operating principle of the joint unit 300 may be essentially similar to those of the joint units disclosed in Korean Patent Application Nos. 2011-86738 and 2011-89854.
[0034] In addition to the above configuration, the joint unit 300 may be configured to further comprise a detachable connecting unit 310 , an opening/closing wire cap 320 , a rolling connecting unit 330 , a holder 332 , a fastener 334 , and a connecting unit 340 .
[0035] The detachable connecting unit 310 may comprise a groove having a P-shape, r-shape or similar shape into which a protrusion of the working end connecting unit 220 may be screwed as necessary. Thus, at least a part of the working end connecting unit 220 may be fitted and fixed to the detachable connecting unit 310 . (That is, the end effector 200 may be fixed to the detachable connecting unit 310 .) In this case, the working end connecting unit 220 and the working end 210 attached thereto may operate together in a roll direction when the detachable connecting unit 310 operates in the roll direction. (That is, the roll direction operation of the end effector 200 may be caused.) To allow for such series of operations, the detachable connecting unit 310 may be fixed to the rolling connecting unit 330 , which may receive the rotational torque of the torque transmission member 500 as will be described below. Meanwhile, the working end connecting unit 220 may be screwed in the opposite direction and detached from the detachable connecting unit 310 , as necessary. (That is, the end effector 200 may be separated from the detachable connecting unit 310 .)
[0036] The opening/closing wire cap 320 may be connected to the opening/closing wire fixing unit 240 while grasping the opening/closing wire 600 . To allow for such connection, the opening/closing wire fixing unit 240 and the opening/closing wire cap 320 may comprise some groove-protrusion structures that may be disposed facing each other. In order to fix the above connection, the fixing ring 250 may be used in the connecting region between the opening/closing wire fixing unit 240 and the opening/closing wire cap 320 .
[0037] The rolling connecting unit 330 may comprise one end having the shape as shown, which may engage with one end of the working end connecting unit 220 , so that it may be connected to and fixed together with the working end connecting unit 220 in the detachable connecting unit 310 . (This fixation may be achieved by screwing in the working end connecting unit 220 as it is engaged with the rolling connecting unit 330 .) Further, the rolling connecting unit 330 may comprise the other end having such a shape that it may be fixed to the connecting unit 340 to be described below, with the holder 332 and the fastener 334 as shown being interposed therebetween. Further reference may be made to Korean Patent Application Nos. 2011-86738 and 2011-89854 in connection with the illustrative principle of connecting the rolling connecting unit 330 and the connecting unit 340 . Meanwhile, the rolling connecting unit 330 may be configured such that the torque transmission member 500 is joined and fixed to the above end. Accordingly, the rolling connecting unit 330 may receive the rotational torque of the torque transmission member 500 to cause the roll direction operation of the end effector 200 . Meanwhile, the rolling connecting unit 330 may further comprise a passage to at least allow the opening/closing wire 600 to be extended and passed to the opening/closing wire cap 320 .
[0038] The connecting unit 340 may be configured to constitute a part of the joint unit 300 and achieve such joint motion as discussed in Korean Patent Application No. 2011-86738 or 2011-89854. The connecting unit 340 may comprise a passage to allow the torque transmission member 500 to operate freely in the roll direction.
Applications
[0039] According to an application of the present invention, those skilled in the art may partially change the form and such of the handling unit or the like so that the wire or torque transmission member of the minimally invasive surgical instrument may be operated by an electric motor or the like of another motor-based system (not shown) such as a surgical robot, as necessary.
[0040] Although the present invention has been described in terms of specific items such as detailed elements as well as the limited embodiments and the drawings, they are only provided to help general understanding of the invention, and the present invention is not limited to the above embodiments. It will be appreciated by a person of ordinary skill in the art that various modifications and changes may be made from the above description.
[0041] Therefore, the spirit of the present invention shall not be limited to the above-described embodiments, and the entire scope of the appended claims and their equivalents will fall within the scope and spirit of the invention. | The present invention relates to a minimally invasive surgical instrument having a detachable end effector. Provided is a minimally invasive surgical instrument comprising a shaft, a joint section which is connected to one end of the shaft, and an end effector which is connected to the joint section and thus is capable of articulatory movement. Therein, the joint section comprises a detachable connection section which can receive rotational torque, and the end effector comprises an operational end-section connection unit which can be attached to the detachable connection section by being screwed in, or can be separated from the detachable connection section by being unscrewed. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of co-pending International Application No. PCT/DE01/04159 filed Nov. 6, 2001 which designates the United States, and claims priority to German application number DE10054977.2 filed Nov. 6, 2000.
TECHNICAL FIELD OF THE INVENTION
The invention relates to a setting device for an adjustable gearing mechanism, in particular for selecting a parking position in an automatic transmission.
BACKGROUND OF THE INVENTION
Conventional automatic transmissions for automobiles usually have four preselection ranges for the different operating states of the automobile, namely a park position, a reverse position, a neutral position, and a drive position. In the park position, a mechanical locking mechanism (park lock) prevents the output shaft of the automatic transmission, and therefore the wheels of the automobile, from turning, thus preventing the automobile from rolling away unintentionally.
The desired preselection range is set by the driver by actuating a gearshift lever, while the link between the gearshift lever and the automatic transmission can be effected, for example, by means of electric cables, this shifting principle being known as “shift by wire”. At the same time it must, however, be ensured that the park lock can also be activated even in the event of a total failure of the vehicle electronics system.
As a solution to this problem, a setting device for an automatic transmission is known from DE 44 22 257 C1, said device comprising, in addition to an electric motor for setting the desired preselection range in normal operation, also a spring which enables the park lock to be activated if the electric motor or the power supply fails. For this purpose, the driver simply has to release the spring, which is under tension during normal operation, by means of a Bowden cable, whereupon the spring activates the park lock.
However, a disadvantage with this known setting device is the fact that in order to activate the park lock in the event of a failure of the power supply, a manual intervention is still required by the driver, in that the latter actuates the Bowden cable.
Furthermore, EP 0 198 114 B1 discloses a setting device for a two-stage gearing mechanism, in which an electric motor axially displaces a rod in order to set the desired gearing mechanism stage, said rod being linked via a spring to a likewise axially movable carriage which carries the selection lever of the gearing mechanism. In this arrangement, the carriage can be locked in two positions by means of a stationary electromagnetically controllable locking element in the form of a solenoid, the two positions of the carriage each corresponding to a gearing mechanism stage. Thus, owing to the locking of the carriage by the locking element, the displacement of the rod by the electric motor does not lead to a change in the gearing mechanism stage, but simply leads to a tensioning of the spring. When the carriage is unlocked, the tensioned spring then drives the carriage into the respective other position, thus causing the other gearing mechanism stage to be set. However, the locking element fixes the carriage in the idle state to ensure that a failure of the power supply or a malfunction of the locking element does not lead to a change in the gearing mechanism stage. Rather, with the known setting device described in the foregoing, in the event of a failure of the power supply the gearing mechanism remains in the gearing mechanism stage just set.
SUMMARY OF THE INVENTION
The object of the invention is therefore to create a setting device for an automatic transmission in which the automatic transmission is controlled via electric cables, the park lock being activated automatically even in the event of a total failure of the vehicle electronics system.
The object is achieved, based on a known setting device for an adjustable gearing mechanism according to a setting element having a setting motion; an intermediate gearing mechanism for transferring the setting motion of the setting element to a control element of the adjustable gearing mechanism, the intermediate gearing mechanism comprising a movably mounted carrier linked to the setting element via a spindle, a carriage mounted in a linearly movable manner in parallel with the carrier and linked to the control element, and a controllable locking element to link the carriage to the carrier or separate it from the carrier; and a mechanical energy store for driving the carriage in the event of a failure of the setting element.
The invention comprises the general technical principle of providing a mechanical energy store in addition to the normal mechanical setting element for selecting the preselection range of the automatic transmission, said mechanical energy store enabling the park lock to be activated in the event of a failure of the normal setting element. An energy store of this type preferably comprises a spring, for example in the form of a helical or flat spiral spring, although other types of energy store which permit the park lock to be activated are also possible.
In a conventional automatic transmission, the preselection range of the automatic transmission is usually set via a control shaft, the angle position of which determines the preselection range. However, the rotation of the control shaft usually requires relatively large torques of up to 12 Nm, with the result that the energy needed for selecting the preselection range of the automatic transmission is transmitted by the mechanical setting element to the control shaft determining the preselection range via an intermediate gearing mechanism.
According to the invention, energy is introduced into the intermediate gearing mechanism via a movably mounted carriage, the carriage being linked on one hand to the energy store and on the other hand, via a controllable locking element, to the setting element. In the locked state, the setting element therefore acts on the carriage and thus enables the desired preselection range to be set. If the setting element fails, on the other hand, the locking element is unlocked, with the result that the movably mounted carriage is now linked only to the energy store and is pushed by the latter into the desired position, causing the automatic transmission to assume the desired preselection range. The controllable locking element for linking the carriage to the setting element preferably comprises an electromagnet, such that the locking element is automatically unlocked in the event of a power failure and thus releases the movably mounted carriage.
The carriage is preferably movable in a linear direction, but in principle it is also conceivable that the carriage is moved on a circular path or a path curved in some other way.
In the preferred embodiment, the setting element is linked to a carrier which is movably mounted parallel to the carriage, the locking element either linking the carriage to the carrier or separating it from the carrier. In normal operation with a properly functioning power supply, the locking element therefore links the carriage to the carrier, which is driven by the setting element such that the setting element moves the carriage and thereby sets the desired preselection range of the automatic transmission. If the power supply fails, on the other hand, the locking element severs the link between the carrier and the carriage, with the result that the setting element no longer acts on the carriage, which is then moved into the desired position by the energy store.
In an embodiment of the energy store as a spring, the spring can be disposed, for example, between the carrier and the carriage and can pretension the carrier with respect to the carriage. As an alternative to this, however, it is also possible that the spring is disposed between the carriage and a thrust bearing fixed in space and pretensions the carriage independently of the carrier with respect to the thrust bearing. In both cases, when carriage and carrier are unlocked, the energy of the tensioned spring leads to the carriage being moved by the spring, whereupon the automatic transmission assumes the desired preselection range.
In a variant of the invention, the carrier has a guide for the movable mounting of the carriage, such that the carriage can be moved relative to the carrier. In another variant of the invention, in contrast, a separate guide is provided both for the carrier and for the carriage.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail below in connection with the description of the preferred exemplary embodiments with reference to the figures, which show:
FIG. 1 shows a setting device according to the invention, wherein the carriage is guided by the carrier,
FIGS. 2 a and 2 b show a setting device according to the invention, wherein the carrier and the carriage each have a separate guide, the carriage being pretensioned by a spring having a thrust bearing fixed in space,
FIGS. 3 a and 3 b show a setting device according to the invention having a separate guide for the carriage and the carrier, the carriage being pretensioned by a spring disposed between the carriage and the carrier,
FIGS. 4 a - 4 d show different forms of compensating elements for compensating for minor setting errors,
FIGS. 5 a and 5 b show an alternative exemplary embodiment of a setting device according to the invention having a stationary unlocking device, and
FIG. 6 shows a further alternative exemplary embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The setting device shown in FIG. 1 as a preferred exemplary embodiment of the invention enables the preselection range to be set for an automatic transmission for an automobile, the preselection range of the automatic transmission being specified by the angle position of a control shaft 1 .
A lever 2 is fixed to the control shaft 1 , because torques of up to 12 Nm are required for a rotation of the control shaft 1 .
These torques are generated by an electric motor 3 having a worm shaft 4 , the worm shaft 4 offering the advantage of being self-locking. As an alternative to the worm shaft 4 , a shaft without self-locking can also be used for driving the spindle housing 5 , however.
The worm shaft 4 acts on a spindle nut, which is disposed in a movably mounted spindle housing 5 , such that the spindle housing 5 can be moved by the electric motor 3 .
The spindle housing 5 further comprises a guide for a carriage 6 , such that the carriage 6 is movable relative to the spindle housing 5 and parallel to this spindle housing.
The spindle housing 5 and the carriage 6 can, however, by locked together by means of an electromagnetic locking element 7 , thereby preventing the carriage 6 shifting relative to the spindle housing 5 .
The carriage 6 comprises a pivot point, via which the carriage 6 is linked to the lever 2 , such that a displacement of the carriage 6 causes a rotation of the lever 2 and the control shaft 1 , as a result of which the desired preselection range of the automatic transmission can be set.
Finally, also provided is an energy store in the form of a spring 8 , which is disposed between the spindle housing 5 and the carriage 6 and pretensions the carriage 6 with respect to the spindle housing 5 .
In the following, the normal operation of the setting device shown in FIG. 1 will now be described first. In this state, the power supply of the automobile is operational, such that the locking element 7 locks together the spindle housing 5 with the carriage 6 . The electric motor 3 can therefore move both the spindle housing 5 and the carriage 6 via the worm shaft 4 and thereby rotate the lever 2 into the desired position.
The following description now explains the mode of operation of the setting device shown in FIG. 1 in the event of a power supply failure. In this case, the locking element 7 releases the lock between the spindle housing 5 and the carriage 6 , with the result that the carriage 6 can move freely, independently of the position of the spindle housing 5 . The pretensioning of the spring 8 then leads to the lever 2 being rotated counterclockwise, with the result that the automatic transmission assumes the park position.
The exemplary embodiment shown in FIGS. 2 a and 2 b largely corresponds to the exemplary embodiment shown in FIG. 1 and described above, so the same reference characters are used below for corresponding components and reference is made to the foregoing description in order to avoid repetition.
Here, FIG. 2 a shows the status of the setting device with a properly functioning power supply, whereas FIG. 2 b depicts the status of the setting device in the case of a power supply failure.
A special feature of the exemplary embodiment of a setting device according to the invention shown in FIG. 2 a and 2 b is that a separate guide 9 , 4 is provided in each case for the spindle housing 5 and for the carriage 6 .
A further special feature is that the spring 8 does not act on the spindle housing 5 , but on a separate thrust bearing 10 that is fixed in space. In this case, the spring 8 therefore pretensions the carriage 6 with respect to the thrust bearing 10 .
The exemplary embodiment of a setting device according to the invention shown in FIGS. 3 a and 3 b largely corresponds to the exemplary embodiment described above and shown in FIGS. 2 a and 2 b , so the same reference characters are used below and reference is made to the foregoing description in order to avoid repetition.
The difference between the exemplary embodiment shown in FIGS. 3 a and 3 b and the exemplary embodiment shown in FIGS. 2 a and 2 b is essentially that the spring 8 is disposed between the spindle housing 5 and the carriage 6 and pretensions the carriage 6 with respect to the spindle housing 5 .
Finally, FIGS. 4 a to 4 d shows different exemplary embodiments of compensating elements which can compensate for minor angle setting errors of the setting device according to the invention.
Thus, in the case of the compensating elements according to FIG. 4 a , the control shaft 1 of the automatic transmission is linked via an elastic toothed belt 11 to an auxiliary shaft 12 , which is rotated by the lever 2 .
In the case of the compensating element according to FIG. 4 b , in contrast, the lever 2 acts on an auxiliary shaft 13 , a segment-shaped lever 14 having likewise segment-shaped cutouts 15 being mounted on the control shaft of the automatic transmission, within which cutouts the lever 2 can be turned. Mounted between the lateral edges of the segment-shaped cutout 15 and the lever 2 in this case are springs 16 , which press the lever 2 into a center position within the segment-shaped cutout without external forces.
In the exemplary embodiment according to FIG. 4 c , the control shaft 1 of the automatic transmission has segment-shaped cutouts 17 , in which the buffer elements of an elastic damping material engage, the buffer elements being appropriately adapted in shape and fixed on an auxiliary shaft 18 , which is turned by the lever 2 .
Finally, the lever 2 in the compensating element according to the invention as shown in FIG. 4 d is elastic and can, for example, assume the positions 2 ′ and 2 ″ in order to compensate for minor setting errors.
The exemplary embodiment of a setting device according to the invention shown in FIGS. 5 a and 5 b largely corresponds to the exemplary embodiment described above and shown in FIGS. 3 a and 3 b , so the same reference characters are used below and reference is made to the foregoing description in order to avoid repetition.
The special feature of the exemplary embodiment shown in FIGS. 5 a and 5 b is that the unlocking element is stationary, as described in the following.
In order to lock together the spindle housing 5 with the carriage 6 , there is provided a locking lever 19 which is pivotably mounted on the top of the spindle housing 5 , the locking lever 19 being able to swivel between a locking position and an unlocking position. In the locking position, a bolt mounted on the front side of the locking lever 19 engages in a corresponding cutout on the top of the carriage 6 , causing the carriage 6 to be locked together with the spindle housing 5 . The locking element further comprises a spring 20 , which pretensions the locking lever 19 in the direction of the locking position, such that the locking lever 19 locks together the carriage 6 with the spindle housing 5 when no external forces act upon the locking lever 19 . On the side opposite to the bolt, the locking lever 19 has an unlocking button 21 , which must be pressed down in order to unlock the locking element.
In order to actuate the locking lever 19 , the locking element also has an unlocking lever 22 , also referred to as a cam sword, which is pivotably mounted in a housing 23 , the unlocking lever 22 being able to swivel about an axis 24 between an unlocking position and a locking position. The unlocking lever 22 is pretensioned here in the direction of the unlocking position by a spring 25 . Also provided is an electromagnet 26 in order to maintain the unlocking lever 22 in the locking position shown in FIG. 5 a against the pretensioning force of the spring 25 . To this end, there is disposed at the top of the unlocking lever 22 a clamping plate 27 , which can be gripped by the electromagnet 26 . In this arrangement, the clamping plate 27 is pivotably mounted on the housing 23 .
The status shown in FIG. 5 a will now be described below, wherein the carriage 6 is locked together with the spindle housing 5 . In this state, the locking lever 19 engages in the latching projection at the top of the carriage, causing the carriage 6 to be locked together with the spindle housing 5 . The locking lever 19 is maintained in this position by the spring 20 until an external force acting on the unlocking button 21 causes the locking lever 19 to rotate in a clockwise direction.
In the locking state shown in FIG. 5 a , the electromagnet 26 is energized and consequently attracts the clamping plate 27 , thus causing the unlocking lever 22 to be maintained in the locking position shown in FIG. 5 a against the pretensioning force of the spring 25 .
In the following, the transition from the locking state shown in FIG. 5 a to the unlocking state shown in FIG. 5 b will now be described. This transition takes place if, for example, the power supply fails. In this case, the electromagnet 26 is de-energized, causing the clamping plate 27 to be released, with the result that the spring 25 turns the unlocking lever 22 counterclockwise. The underside of the unlocking lever 22 then comes into contact with the unlocking button 21 of the locking lever 19 and turns the locking lever 19 in a clockwise direction until the bolt mounted on the front side of the locking lever 19 releases the latching projection on the top of the carriage, thus causing the carriage 6 to be disengaged from the link housing. A spring 28 mounted between the spindle housing 5 and the carriage 6 then causes the carriage 6 to be pushed to the left and finally assume the park position.
The transition from the locking state shown in FIG. 5 a to the unlocking state shown in FIG. 5 b was described above for the situation in which the power supply fails. However, this transition can also take place if the electromagnet 26 is driven with opposite polarity, causing the electromagnet 26 to repel the clamping plate 27 .
In the following, the transition from the unlocking or park position shown in FIG. 5 b to the locking position shown in FIG. 5 a will now be described. This transition takes place if the power supply of the electromagnet 26 is restored after a temporary failure. In this case, the electric motor 3 rotates the worm shaft 4 , causing the spindle housing 5 to be pushed to the left in the direction of the carriage 6 . In this process, the spring 28 is put under tension once more in order to be able to push the carriage 6 into the park position again in the event of a subsequent power failure. In addition, a load pin 29 flips out on the top of the spindle housing 5 when the locking lever 19 is unlocked; when the spindle housing 5 moves in the direction of the carriage 6 , this load pin causes the unlocking lever 22 to be raised to a point where the electromagnet 26 can grip and attract the clamping plate 27 . For this purpose, the unlocking lever 22 has a guide called a load curve, in which the load pin 29 travels along and at the same time raises the unlocking lever 22 .
Upon reaching the carriage 6 , the locking lever 19 automatically engages in the latching projection on the top of the carriage 6 , causing the carriage 6 to lock together once again with the spindle housing 5 .
It should further be mentioned that on the underside of the unlocking lever 22 there is mounted a projection 30 which, in the park position, prevents the carriage 6 from being unlocked from the spindle housing 5 . In the park position, namely, the spindle housing 5 is located beneath the projection 30 , with the result that the unlocking lever 22 cannot be pressed down so far that the locking lever 19 is turned accordingly.
Instead of the projection 30 , however, a cutout can also be disposed on the front side of the unlocking lever 22 , said cutout being located above the unlocking button 21 and preventing the unlocking lever 22 from pressing down the unlocking button 21 as long as the spindle housing 5 is in the park position.
As an alternative to the embodiment of the locking lever 19 shown in FIGS. 5 a and 5 b , the locking lever 19 can also be implemented as an articulated lever, the lever arms on both sides of the swiveling axis being at an angle to each other. In this arrangement, a better transmission ratio can be achieved.
The exemplary embodiment shown in FIG. 6 largely corresponds to the exemplary embodiment described above and shown in FIGS. 5 a and 5 b , so in order to avoid repetition, reference is made to the foregoing description and the same reference characters are used below.
The special feature of the exemplary embodiment shown in FIG. 6 is the manner in which the spindle housing 5 is unlocked from the carriage 6 . To this end, there is provided a rotatably mounted camshaft 31 , which is disposed above the locking lever 19 and is driven by an electric motor 32 . In the position shown in FIG. 6, the camshaft 31 is in the locking position, i.e. the camshaft 31 is not in contact with the unlocking button 21 of the locking lever 19 . Conversely, in order to unlock the spindle housing 5 from the carriage 6 , the camshaft 31 is rotated through 90°, causing the locking lever 19 to be pressed down.
In one variant, the cross-section of the camshaft 31 deviates from the circular form only over a small angle range of, for example, 90°. As a result, the transmission of energy to achieve the necessary lift is worse than with a radius increasing over the entire circumference of the camshaft 31 . The advantage, however, lies in the possibility of the camshaft 31 being supported by the housing along the entire length of the carriage movement. Suitable stops are provided in the end positions. As a result, no motor position control is required. The electric motor 32 must be able to turn in both directions.
In another variant, the electric motor 32 turns in one direction only. This simplifies the control of the electric motor 32 . Depending on the operating time, the electric motor 32 may operate the locking lever 19 a number of times, one actuation being sufficient for correct unlocking.
In a further variant, the camshaft has a radius that increases over its entire circumference, which results in a better transmission of energy. Stops are provided at the end positions, with the result that no motor position control is required. In this case, the electric motor 32 must be able to turn in both directions.
Finally, the camshaft 31 can also exhibit an increasing radius over its entire circumference, the transition being rounded. In this case the electric motor 32 turns in one direction only. This simplifies the control of the electric motor 32 . Depending on the operating time, the electric motor 32 may operate the locking lever 19 a number of times, one simple actuation being sufficient for correct unlocking.
If no stops are provided at the end positions of the camshaft, it is necessary to provide either a sensor system for determining the angle position or a clutch between the electric motor 32 and the camshaft 31 .
Behind the lever 2 in the pivoting plane of the lever 2 there is further disposed a sensor mat, which enables the setting angle of the lever 2 to be determined.
The invention is not limited to the above-described exemplary embodiments according to the invention. Rather, a plurality of variants and adaptations that make use of the inventive idea are conceivable and therefore also fall within the scope of protection. | The invention relates to a setting device for an adjustable gearing mechanism, in particular, for selecting a parking position in an automatic transmission. The inventive setting device comprises a mechanical setting element, an intermediate gearing mechanism for transferring the setting motion of the setting element to a control element of the adjustable gearing mechanism. A mechanical energy store, which can be replenished once again by the setting element, is provided for driving the intermediate mechanism when the setting element malfunctions. | 5 |
This is a continuation of application Ser. No. 623,356, filed June 22, 1984, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to an information display apparatus and, more particularly, to an information display apparatus including a plurality of information display apparatuses, each of which has a display for displaying a variety of information and a telephone set which is to be automatically connected to a destination while information thereof is on display.
When one intends to select a hotel for room reservation among many hotels available in a pertinent area, he or she usually contact the front desks of hotels with reference to advertisement columns of telephone directories. Usually, therefore, one is to contact only a couple of hotels, and information about all available hotels is not to be obtained.
For this reason, it is very difficult to check into the most suited hotel.
The primary object of the present invention is to provide an information display apparatus, which is to display information of many hotels in succession on a display and a telephone set of which is to be connected to an intended hotel by merely unhooking the handset while information of that hotel is on display.
Another object of the present invention is to provide an information display apparatus, which includes a source discriminatingsection provided at the front desk of each subscriber hotel and discriminates the location of an information display apparatus as a source of an incoming call, thus providing for perfection of service.
A further object of the present invention is to provide an information display apparatus which is to provide facsimile guide to the user.
The information display apparatus according to the present information is installed in or in front of a railroad station hall, for instance, and it is to display hotel informatin, such as appearance, room interior and variour facilities, of many hotels in succession on a display screen. The user may find a suited hotel while information of successive hotels is displayed on the display being watched. By unhooking the handset while the information of the suited hotel is on display, the telephone set is connected to the front desk of that hotel, so that room reservation may be made by confirming the charge or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings illustrating preferred embodiments of the present invention:
FIG. 1 is a perspective view showing a first embodiment;
FIG. 2 is a perspective view showing a second embodiment;
FIG. 3 is a block diagram showing the electric circuitry of the system according to the present invention;
FIG. 4 is a schematic representation of a logic control section, a dial number memory section and a dial number search section;
FIG. 5 is a schematic representation of a decoder and a control circuit;
FIG. 6 is a circuit diagram of a telephone circuit control section;
FIG. 7 is a circuit diagram showing a voice control section;
FIG. 8 is a connection diagram showing a printer;
FIG. 9 is a circuit diagram showing a source discrimination unit; and
FIG. 10 is a perspective view showing a further embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, reference numeral 1 designates a logic control section, which includes a central processing unit 2, a program memory 3 and an I/O port 4.
Reference numeral 5 designates a display/memory control section, which includes a decoder 6, a video disc library 7 and a control circuit 8. The decoder 6 receives a control signal from the I/O port 4. The video disk on which is library 7 includes a disk recorded various information. The control circuit 8 controls the video disc library 7 according to the control signal provided from the decoder 6.
The control circuit 8, as shown in detail in FIG. 5, has a remote control unit 9 for controlling the video disc library 7 and an analog switch group 10 connected to the remote control unit 9. Individual switches of the analog switch group 10 are operated according to control signal from the decoder 6, thus operating the remote control unit 9 for controlling the video disc library 7.
Reference numeral 11 designates a display screen, which constitutes a display section for displaying signal reproduced by the display/memory control section 5. Reference numeral 12 designates an operating switch section, which includes a search switch 13 and a call switch 14 as shown in FIG. 1. Reference numeral 15 designates a coin/card insert section, which permits selective insertion of coins and cards. Reference numeral 16 designates a card reader section for restricting the users. This section is constructed such that coins are to be inserted as well. Reference numeral 17 designates a coin detector section for confirming the coin inserted through the card insert section 15. The card reader section 16 and coin detector section 17 are connected to the logic control section 1.
Reference numeral 18 designates a dial number memory section, in which dial numbers pertaining to various information recorded on video discs provided in the video disc library 7 are stored. Reference numeral 19 designates a dial number search section for searching for a dial number to be read out from the dial number memory section 18. Reference numeral 20 designates a telephone circuit control section connected to telephone circuit. It includes a push-button tone generator 21 for so-called push-button dial telephone set and a dial pulse relay section 22 for dial telephone set. Reference numeral 24 designates relay switches for the dial pulse relay section 22, and numeral 25 terminals to be connected to the telephone circuit. When a dial number of a destination displayed on the display section 11 is read out from the dial number memory section 18, it is once read into the dial number search section 19 and thence transferred through the I/O port 4 to the telephone circuit control section 20. When the telephone set employed is of the push-button type, it operates the dial pulse relay section 22 to continually hold the relay switch 24 "on". In this state, the push-button tone generator section 21 generates a destination telephone set call signal, whereby the telephone set is connected to an external telephone circuit. When the employed telephone set is of the dial type, the dial pulse relay section 22 on-off operates the relay switch 24 to generate dial pulses, whereby a call signal is sent to the external telephone circuit. Subsequently, the relay switch 24 is held "on".
Reference numeral 26 designates a voice control section which produces voice informing the user of how to use the apparatus. It includes a voice memory section 27, a counter section 28, an address section 29 and an amplifier 30. The voice memory section 27 produces various stored guide voices, e.g., "Push button" and "Unhook handset". The counter section 28 determines the period of start of reading of stored voice data and the address section 29 determines the position of start of reading. Reference numeral 31 designates a loudspeaker.
Reference numeral 32 designates a printer which is to print part or all of the information displayed on the display section 11 on a recording sheet. This printer is connected to the I/O port 4, as shown in FIG. 8. In the drawings, reference numeral 33 designates the console of the apparatus, numeral 34 the handset, numeral 35 a guide plate, on which a guide for use of the apparatus is described, and numeral 36 a destination telephone set.
Reference numeral 38 designates a source disciminator section. It includes a hybrid IC 39 and a voide synthesis IC 40. When a telephone circuit to the destination telephone set 36 is set up, the source discriminator section 38 informs the destination of the location of the information display apparatus as a source of call. Reference numeral 41 designates a terminal which is connected to a terminal 42 shown in FIG. 6. Reference numeral 23 designates a relay switch which is operated by a relay 45. When a telephone circuit to the destination telephone set 36 is set up, the source discriminator section 38 is connected to and held in connection to the destination telephone set 36 for 1 to 2 seconds.
FIG. 2 shows a second embodiment of the present invention. In this embodiment, numeral keys 37 are provided on the console 33. These keys 37 may be operated for selecting various video disc information in the video disc library 7. As an example, by operating the numeral key labeled "1" in FIG. 2, hotel information is displayed. By operating numeral key labeled "2", information of motion pictures is displayed. In this way, a variety of information accommodated in various video discs is to be selected for display.
Reference numeral 43 designates a facsimile set connected to the connection terminal 25 of the telephone circuit control section 20. Reference numeral 44 designates a record sheet outlet of the facsimile set 43.
The operation will now be described.
Video discs on which information of predetermined hotels is stored are provided in the video disc library 7 in the display/memory control section 5. When a power source for the apparatus provided in the console 33 is turned on, a variety of information is successively displayed on the display section 11, usually with a constant interval time (e.g., 10 seconds). At this time, only an outline, and not the details, of information is displayed on the display section 11. Of the successively displayed information, a desired item of information is selected by operating the numeral keys 37. For instance, by operating numeral key "1" in FIG. 2 hotel information is selected. By operating numeral key "2" information of motion picture theaters is selected. After the desired item of information is selected, the search switch 13 is operated. As a result, display information displayed on the display section 11 is fast fed, for instance at an interval of 5 seconds, to successively display the outline of hotels. When informatin of a suited hotel is displayed, the search key 13 is released. As a result, detailed information of that hotel (usually about three frames) are successively displayed, while at the same time commercial voice is produced from the loudspeaker 31. In this case, the last frame is displayed for a longer period, e.g., 10 seconds.
When the user is satisfied with the detailed information, he or she unhooks the handset 34, inserts a magnetic card (or a coin) into the card insert section 3, and depresses the call switch 14. As a result, the dial number corresponding to the displayed information is automatically searched from the dial number memory section 18, and a telephone circuit to the telephone set 36 in that hotel is set up. Before the user's speech starts, the destination hotel is informed of the location of the information display apparatus as the source of call in synthesized voice, for instance telling "New York" reproduced from data stored in the voice synthesis IC, for instance for a period of a couple of seconds.
If the user desires a detailed map, catalogue, charge table, etc. of the destination, it may be obtained from the facsimile set 43.
If the user does not want to make reservation, he or she may wait for 10 seconds or depress the search switch 13 once again. As a result, display of following outline information is resumed.
The procedure of operation as described is announced in voice to the user from the loudspeaker 31 through the voice control section 26 aside from the procedure guide described on the guide plate 35. For example, when the logic control section 1 determines that the next situation is for the search of a suited hotel, it takes out information of voice telling "Keep search button depressed until your favorite hotel is displayed." from the voice memory section 27 through the address section 29. The voice information is amplified through the amplifier 30 and uttered from the loudspeaker 31 at an output timing determined by the counter section 28.
As has been described before, in case when one intends to select a hotel for room reservation he or she usually contacts the fronts of hotels with reference to telephone directory advertisement columns so that he or she is to contact only a couple of hotels at the most. For this reason, if a called hotel has vacant room, the room is selected for reversation in most cases. That is, even if there are more suited hotels having vacant rooms, these hotels are not utilized for usually it is impossible to contact all the hotels in the pertient area one after another.
This is possible according to the present invention. In other words, with the information display apparatus according to the present invention, a number of hotels are displayed in succession, and merely unhooking the handset while information of a suited hotel is on display sets up the telephone circuit to that hotel. According to the present invention, it is thus only necessary to wait until information of a suited hotel appears on display. | An information display apparatus is disclosed, which includes a plurality of information display apparatus installed, for instance, in or in front of railroad station halls. Each information display apparatus comprises a display (i.e., a television screen), a keyboard and a telephone handset or the like. When the handset is unhooked while hotel information (of information about restaurants or travel agencies or commercial guides of mail-order sales companies or job offer guides, such information generally referred to as hotel information) is on display, a telephone circuit of the apparatus is connected directly to the front of a hotel, the information of which is on display. | 7 |
This is a division of U.S. application Ser. No. 07/607,838, filed Oct. 31, 1990 now U.S. Pat. No. 5,115,034, which is a continuation of U.S. Ser. No. 07/316,016, filed Feb. 27, 1989, abandoned, which is a division of U.S. Ser. No. 07/107,292, filed Oct. 9, 1987, now U.S. Pat. No. 4,857,618.
TECHNICAL FILED
This invention relates to aninonically-prepared copolymers containing organometallic-substituted styrene.
BACKGROUND ART
According to Odian, Principles of Polymerization, 2nd Ed., Wiley-Interscience, p. 18, (1981) polymers fall into three structural groups: linear, branched and crosslinked. Branched polymer molecules are those in which there are side branches of linked monomer protruding from various central branch points along the main polymer chain and that have several idealized configurations. Branched polymers are known in at least three configurations. They may be "comb-like" where each branch is of equal length, "dendritic" where branches occur on branches (series branching), or "star-like" where all branches radiate from a single point.
Branching often imparts various desirable properties, for example, branched polymers have been made that have improved melt flow and processability. Additionally, appropriate branching disrupts long linear polymer backbones to thereby reduce crystallinity. In free radical and cationic polymerization processes, for example in the production of polyethylene, branching is largely uncontrolled and its extent is dependent on polymerization variables. In some cases branching can be as high as 15-30 branches per 500 monomer units. In contrast, anionic polymerization processes yield very narrow molecular weight distributions and a unique structure. Branched polymer structures produced by anionic polymerization are generally star shaped (arrayed about a central point or nucleus) although the structure can be varied by coupling together individually prepared arms of different structure.
Such polymers are described by St. Clair in U.S. Pat. No. 4,391,949 where "asymmetric" star block copolymers are prepared by mutually linking together individually prepared living polymers, which may be represented by (AB)Li and (C)Li, with polyalkenylaromatic linking reagents. The structural formula describing the resulting polymer is given as (A--B) x --Y--(C) z , where x plus z is greater than six. A statistical distribution of polymer products would be obtained from this process, where the average structure is equal to the mole ratio of the respective charges. Further chain growth would only be possible through the linking nucleus Y.
Crossland, U.S. Pat. No. 4,010,226, has also recognized the problem of preparing block polymers with an asymmetric configuration and, to avoid the statistical distribution of polymers obtained by St. Clair, first coupled a set of polymer arms with divinylbenzene, then continued the polymerization, utilizing the anionic centers that remain on the divinylbenzene residue, to produce a different set of arms bound to the same nucleus. The number of new arms grown would thus equal the number of arms coupled together, since linking with divinylbenzene (DVB) is a non-terminating process and each newly grown arm would have an anionic terminus. Fahrbach, U.S. Pat. No. 4,086,298, discloses star-block copolymers having a mixture of arms where some arms are formed by first polymerizing styrene with alkyllithium to form living polymer blocks, represented by (A)Li, and then adding a mixture of styrene and butadiene to form a graded copolymer represented by A-B→A' where the arrow represents a graded segment. Other arms are made up of only the butadiene-styrene graded copolymer segment. These arms are then linked together with a polyfunctional coupling agent, such as DVB, to give star-branched polymers. U.S. Pat. Nos. 4,221,884, 4,248,980, 4,248,982, 4,248,983, and 4,248,984, Bi and Milkovich, describe a similar series of polymers in which more complex polymer arm segments are linked together using a polyalkenyl aromatic, such as divinylbenzene, to form an asymmetric star molecule.
Prudence (U.S. Pat. No. 3,949,020) prepares branched block polymers by a method wherein divinylbenzene is added with the diolefin monomer to a polystyryllithium initiator. However, according to Bi and Fetters (Macromolecules 9, 732-742 [1976]), such a method leads to gelatin when the divinylbenzene/initiator ratio is three or greater.
Martin, in U.S. Pat. Nos. 4,080,400, 4,143,089, 4,148,838, and 4,273,896, describes a composition obtained from the linking together of anionically active polymers (from, e.g., styrene) with silanes of the formula, X 4-a-b Si(R) b (C═CH 2 ) a , where X is a displaceable group, R is alkyl, a is 1 to 4 and b is 1 to 3. One of the stated objects of these patents is to couple polymeric carbanions with silanes and then form new carbanions which can be used to initiate the polymerization of cyclic silicones or "other unsaturated monomers". No disclosure is provided directed towards the step of using other unsaturated monomers except for certain unspecified hydrocarbon/siloxane block polymers.
It has been established [Nametkin, Chemical Abstract Nos 85:47314a (1976), 87:185046g (1977), and 89:110569n (1978)] that vinylsilanes of the type described by Martin will copolymerize in an anionic fashion, for example with butadiene; however, reactivity is very low, with up to 300 hours required for good conversion. Furthermore, copolymers of vinyl silanes with dienes initiated by butyl lithium are unimodal but exhibit peak broadening due to the occurrence of chain termination reactions caused by spontaneous cleavage reactions producing lithium hydride (Nametkin, Chemical Abstract No. 93:168679x, 1980). Loss of LiH during anionic homopolymerization of vinyltrimethylsilane has also been observed and has been used to explain the poor conversion and spread in molecular weight distribution observed in these polymers [Nametkin, Dokl. Nauk SSSR, 215, 861 (1974)]. Chaumont [Eur. Poly. J. 15, 537 (1979)] prepared vinylsilyl terminated polystyrenes via anionic polymerization; however, it was necessary to cap the polymer anion with diphenylethylene in order to reduce side reactions.
Chlorosilane-substituted styrenes are well-known compounds and have been used, for example, to prepare polysiloxane macromolecular monomers [Kawakami, Polymer J., 14, 913 (1982)]. Chromatography gels have been described based on poly-α-methylstyrene dianions and chlorodimethyl-silylstyrene [Greber, Angew. Makromol. Chem. 1971, 16/17, 325]. Compositions for the encapsulation of electrical equipment have been derived from organosilicon monomers having styrenyl groups (Lewis, U.S. Pat. No. 2,982,757). Hirao et al. (Macromolecules 1987, 20, 242) has studied the anionic homopolymerization of (4-alkoxysilyl) styrenes and reaction of the resultant homopolymer with polystyryllithium.
There has been no disclosure, however, of the use of organometallic-substituted styrenes, e.g., chlorosilane-substituted styrenes, in the preparation of condensed phase polymers.
SUMMARY OF THE INVENTION
The present invention provides elastomeric copolymers and block copolymers, e.g., based upon styrene/isoprene, having a novel condensed phase structure wherein polymer branches occur along the polymer backbone, either at a predetermined location or at random locations. The polymers of the present invention are made by a method which comprises the step of reacting, under polymerization conditions, hydrocarbyl lithium initiator, at least one anionically polymerizable compound, and an organometallic-substituted styrene condensing agent. The reactants may be added simultaneously to produce a copolymer with polymer branch segments randomly located along the polymer backbone or sequentially to produce a copolymer with branches located at the same predetermined location along the polymer backbone. The resultant polymers may be further reacted with a linking agent to form multi-arm copolymers. The method of making the copolymers is claimed in U.S. application Ser. No. 107,292, filed Oct. 9, 1987, now U.S. Pat. No. 4,857,618.
The resultant elastomeric polymers are compatible with any of a wide variety of known tackifier resins and plasticizers to produce unique pressure-sensitive adhesive compositions. The pressure-sensitive adhesive compositions are claimed in U.S. application Ser. No. 107,289, filed Oct. 8, 1987, now U.S. Pat. No. 4,906,691.
Specifically, the method comprises the step of reacting, under polymerization conditions, the following:
(a) hydrocarbyl lithium initiator;
(b) at least one anionically polymerizable compound; and
(c) a condensing agent having the general formula
CH.sub.2 ═C(R')QY(R).sub.n (X).sub.m I
wherein
Y is tetravalent Si, Ge, Sn or Pb;
X is H, --OR", Cl, Br or F wherein R"is a monovalent lower alkyl group having from 1 to 6 carbon atoms;
R" is hydrogen, a monovalent lower alkyl group having from 1 to 6 carbon atoms, or phenyl;
Q is phenylene;
R" is hydrogen, a monovalent lower alkyl group having from 1 to 6 carbon atoms, or phenyl;
m is an integer of 1, 2, or 3; and
n is an integer equal to 3-m,
in a mole ratio of (a) to (c) of about (1 +m):1 to form a condensed phase copolymer.
The elastomeric polymers are anionic copolymers comprising at least one anionically polymerizable monomer and a condensing agent (I monomer wherein the mole percentage of condensing agent (I) in each copolymer segment containing the condensing agent (I) is in the range of about 0.01% to about 5%.
The polymers of this invention are generally copolymers of the condensing agent (I) with conjugated diene monomer, or are block copolymers of conjugated diene and vinyl aromatic monomers (wherein at least one block is a copolymer of condensing agent monomer and either diene or vinyl aromatic monomer). The monovinyl aromatic monomer yields a hard polymer segment having a high T g , i.e., above 25° C. The conjugated diene monomer yields a soft (generally elastomeric) polymer segment having a low T g , i.e., not greater than about 0° C.
The polymers of the invention are preferably elastomeric anionic polymers comprised of conjugated diene monomer, typically containing 4 to 12 carbon atoms, monoalkenyl or monovinyl aromatic monomer and the condensing reagent (I) wherein the mole percent of condensing reagent in a polymer segment containing such reagent is about 0.01 to about 5.0, preferably about 0.02 to about 2.0. Typically, the copolymer contains on a weight basis from about 50% to about 90% conjugated diene and about 50% to about 10% monoalkenyl or vinyl aromatic monomer.
In one embodiment, branch points are introduced at predetermined loci in the polymer chain by addition of condensing agent in a sequential fashion, i.e., after formation of a living polymer segment via conventional anionic polymerization techniques. Thus, copolymer is prepared by first forming a living linear polymer segment, then reacting the living polymer segment with the condensing reagent to form a condensed living copolymer and next polymerizing therewith additional polymerizable compound to form a condensed phase block copolymer. Such a block copolymer may be represented by the following general formula:
(A).sub.x Z.sub.q --B II
where:
A is a nonelastomeric polymer segment based on a monovinyl aromatic compound such as styrene, alpha-methylstyrene, para-methylstyrene, and t-butyl styrene;
B is an elastomeric polymer segment based on a conjugated diene compound, such as butadiene, isoprene, and piperylene;
Z is the residue of a condensing reagent having the general formula
CH.sub.2 ═C(R')QY(R).sub.n (X).sub.m I
where
X, R, Y, Q, R', m and n have been defined above;
q is an integer from 1 to about 10;
x is an integer from 2 to about 10; and
wherein the mole percentage of Z in the segment (A) x Z q is in the range of about 0.1% to about 5%.
The method comprises the further step of contacting the resulting condensed phase block copolymer of Formula II with a multifunctional linking agent such as a polyalkenyl aromatic linking agent under reactive conditions thereby forming a multi-arm condensed phase block copolymer. Such a block copolymer may be represented by the following general formula:
[(A).sub.x Z.sub.q --B].sub.y L.sub.z III
where:
A, Z, B, x, and q have been defined above;
L is the residue of a multifunctional linking agent;
z is an integer from zero to about 10;
y is an integer from 1 to about 50 and, when y is 1, z is zero;
wherein the mole percentage of Z in the segment (A) x Z q is in the range of about 0.1% to about 5%.
The method also comprises first forming a living linear polymer segment, adding a second polymerizable compound to form a living linear block copolymer segment, then reacting the living linear block copolymer segment with the condensing reagent to form a condensed living block copolymer, and next polymerizing therewith additional polymerizable compound to form a condensed phase block copolymer represented by the following general formula:
(A--B).sub.x Z.sub.q --B IV
where:
A, B, Z, x and q are defined above and wherein the mole percentage of Z in the segment (A--B) x Z q is in the range of from about 0.01% to about 1%.
The method comprises the further step of contacting resulting block copolymer IV with a multifunctional linking agent under reactive conditions thereby forming a multi-arm condensed phase block copolymer represented by the general formula shown below:
[(A--B).sub.x Z.sub.q --B].sub.y L.sub.z V
wherein:
A, B, Z, L, x, q, y and z are defined above and wherein the mole percentage of Z in the segment (A--B) x Z q is in the range of about 0.01% to about 1%.
Other condensed phase block copolymers besides II and IV are also contemplated and may be linked to form multi-arm condensed phase block copolymers other than III and V. Such block copolymers, including II, III, IV, and V, may be represented by the general formula:
[(W).sub.x Z.sub.q --W'].sub.y L.sub.z VI
wherein:
W is selected from the group consisting of A, S, BA, and AB, W' is selected from the group consisting of B, BA and AB, and A, B, Z, L, x, q, y and z are defined above, and wherein the mole percentage of Z in the segment (W) x Z q is in the range of from about 0.01% to about 5%.
In a second embodiment, randomly placed branch centers are generated on the polymer chain by polymerization of a mixture of condensing agent and anionically polymerizable monomer or monomers. The method involves simultaneously reacting a hydrocarbyl lithium initiator, polymerizable compound, and condensing reagent to form a living condensed phase copolymer having a randomly structure which may be represented by the following general formula:
B/Z VII
wherein B and Z are defined above, and wherein the mole percentage of Z in the copolymer is from about 0.01% to about 1%.
Copolymer VII may be further reacted with a multifunctional linking agent, thereby forming a multi-arm condensed phase copolymer. Such a copolymer may be represented by the general formula:
(B/Z).sub.y L.sub.z VIII
wherein B, Z, L, y and z are defined above, and wherein the mole percentage of Z in the unlinked copolymer is from about 0.01% to about 1%.
Monovinyl aromatic monomer may be polymerized with condensing reagent to form a randomly-branched living copolymer which may be further treated by adding a different polymerizable compound such as butadiene, isoprene, or piperylene, after completion of the simultaneous reaction and permitting the different polymerizable compound to copolymerize with the living copolymer to form a condensed phase block copolymer. The resultant copolymer may be further reacted with a multi-functional linking agent thereby forming a multi-arm condensed phase block copolymer. Such block copolymer may be represented by the general formula:
[(A/Z)--B].sub.y L.sub.z IX
wherein A, B, Z, L, y and z are defined above, and wherein the mole percentage of Z in the segment A/Z is in the range of from about 0.1% to about 5%.
In addition, a randomly-branched living polymer derived from monovinyl aromatic monomer may be further treated by adding a mixture of a different polymerizable compound and additional condensing reagent, after completion of the simultaneous reaction, and permitting the mixture to copolymerize with the living copolymer to form a block copolymer having "condensed" structure randomly placed in both blocks. This block copolymer may be further reacted with a multifunctional linking agent under reactive conditions thereby forming a multi-arm condensed phase block copolymer. Such a block copolymer may be represented by the general formula:
[(A/Z)--(B/Z)].sub.y L.sub.z X
wherein A, B, Z, L, y and z are defined above, and wherein the mole percentage of Z in the segment A/Z is in the range of from about 0.1% to about 5% and in the segment B/Z is from about 0.01% to about 1%.
Alternatively, a different condensed phase block copolymer may be prepared by first forming a living linear polymer segment, adding a mixture of a second polymerizable compound and the condensing reagent, and then permitting the mixture to copolymerize with the living linear polymer segment produced by polymerization of the first polymerizable compound. The resulting block copolymer may be further modified by contacting it with a multifunctional linking agent under reactive conditions thereby forming a multi-arm condensed phase block copolymer. Such a block copolymer may be represented by the general formula:
[A--(B/Z)].sub.y L.sub.z XI
wherein A, B, Z, L, y and z are defined above, and wherein the mole percentage of Z in the segment B/Z is in the range of from about 0.01% to about 1%. The unlinked block copolymer may be alternatively modified to include an additional linear polymer segment to provide a block copolymer which may be represented by the general formula:
A--(B/Z)--A XII
wherein A, B and Z are defined above.
BRIEF DESCRIPTION OF DRAWINGS
Understanding of the invention will be facilitated by reference to the drawings, wherein:
FIGS. 1 and 2 are graphs depicting the melt viscosity of untackified and tackified polymers according to the invention and a styrene isoprene linear triblock copolymer (Shell's Kraton® 1107) according to the prior art as a function of shear rate; and
FIG. 3 is a graph depicting the steady shear viscosity of polymer according to the invention and a styrene isoprene linear triblock copolymer (Shell's Kraton® 1107) according to the prior art as a function of shear rate.
DETAILED DESCRIPTION
The initiators useful in the preparation of the copolymers of this invention are known alkyllithium compounds such as methyllithium, n-butyllithium and sec-butyllithium, cycloalkyllithium compounds such as cyclohexyllithium, and aryllithium compounds such as phenyllithium, naphthyllithium and the like.
Useful monoalkenyl aromatic monomers include styrene, ring-substituted styrenes, and alpha-substituted styrenes. These can be used individually or as mixtures. Preferred are styrene, alpha-methylstyrene, para-methylstyrene, and t-butylstyrene. Useful conjugated diene monomers have 4 to 12 carbon atoms, e.g., 1,3-butadiene, isoprene, piperylene, myrcene, 2,3-dimethylbutadiene, and the like. These also may be used individually or as mixtures. Preferred conjugated diene monomers are 1,3-butadiene, isoprene, and piperylene.
The "condensed phase" or branch structure of the copolymers of this invention is formed by addition of a multifunctional "condensing" reagent to create points at which two or more polymer segments are connected together by the reagent. The terminology "condensed" is derived from the term "polycondensation" which, according to Chemical Kinetics edited by C. H. Bamford (Elsevier, 1976), is used to denote those polymerization reactions which proceed by a propagation mechanism in which an active polymerization site disappears every time one monomer equivalent reacts. Also, Webster's 7th Collegiate Dictionary defines condensation as a chemical reaction involving union between atoms in the same or different molecules often with elimination of a simple molecule to form a more complex compound of often greater molecular weight. It should be pointed out that the linking processes that occur with "condensing" reagents and linking agents such as divinylbenzene are very different. "Condensing" reagents yield a polymeric species with a single anionic charge, whereas divinylbenzene joins polymer segments together to give a nucleus containing a number of anions equal to the number of chains linked together. Thus, the potential for network formation and gelation associated with the method of Prudence is avoided by use of "condensing", rather than linking, agents.
Suitable condensing agents are compounds having dual functionality, the first derived from at least one anionically polymerizable group and the second from at least one other group capable of undergoing one or more nucleophilic displacement reactions. One active chain is terminated by each nucleophilic displacement reaction. The relative reactivity of the two groups is unspecified, such that anion addition may be faster or slower than termination, and the preference of relative reactivity for the two groups will depend on the final polymer structure desired. The condensing agent must be compatible with anionic polymerization processes; i.e., its anionically polymerizable group(s) should be capable of reinitiating polymerization of itself or other anionically polymerizable monomers. Useful condensing agents are molecules of the following structure: ##STR1## wherein Y is tetravalent Si, Ge, Sn, or Pb;
X is H, --OR", Cl, Br, or F, wherein R" is a monovalent lower alkyl group having from 1 to 6 carbon atoms;
R is hydrogen, a monovalent lower alkyl group having from 1 to 6 carbon atoms, or phenyl;
R' is hydrogen, a monovalent lower alkyl group having from 1 to 6 carbon atoms, or phenyl;
m is an integer of 1, 2, or 3; and
n is an integer equal to 3--m.
The displaced group, X, does not subsequently react in a side reaction with polymer anions. The alkenylaromatic group may be substituted in the alpha position with alkyl or aromatic moieties, R', to modify condenser reactivity. The alkenylaromatic group may also be further substituted on the aromatic ring with groups such as alkyl, phenyl, alkoxy, dialkylamino, and the like, which are not reactive toward polymer anions. Preferred condensing agents are the silylstyrenes for which R is methyl, R'is hydrogen, Y is silicon, and X is F, Cl, Br, or methoxy, or, most preferably, X is F or Cl.
The above-described condensing agents are readily prepared via an in situ Grignard reaction involving, e.g., para-chlorostyrene and chloroalkylsilane. Other routes for the preparation of these compounds have been described by Chernyshev (Chemical Abstracts 62:6502c). The condensing agents are utilized to achieve a branched or condensed phase polymer structure by addition of 1/n mole of multifunctional condenser per mole of active polymer anions, where n is the total number of anionically reactive sites on the condenser molecule. The mole percentage of condensing agent monomer in any particular polymer segment is generally within the range of from about 0.01% to about 5%, preferably, within about 0.02% to about 2%. (For monovinyl aromatics, the range is about 0.1-5%, with about 0.2-2% preferred; for conjugated dienes, the range is about 0.01-1%, with about 0.02-0.2% preferred.)
Conventional anionic polymerization techniques are utilized in preparing the condensed phase polymers of this invention. Thus, the polymerization is carried out in an inert atmosphere in the absence of moisture, air, or other impurities which are known to react with polymer anions. A temperature between 0° C. and 100° C., more preferably between 30° C. and 80° C., is maintained. Suitable solvents are hydrocarbon solvents which may be aliphatic, cycloaliphatic, or aromatic. Optionally, ethers such as tetrahydrofuran, diethylether, or other similar solvents, may be used either alone or as mixtures with the hydrocarbon solvent.
If so desired, linking agents may be used to increase the degree of branching of the condensed phase copolymers or block copolymers beyond that achieved via the condensing agent. In this way, symmetrical polymer architectures such as radial or star structures, etc., can be created, the final structure being a function of the linking molecule. Such multifunctional linking agents are well-known in the art and are detailed, e.g., in U.S. Pat. No. 3,985,830. Preferred examples of such compounds are 1,2-dibromoethane, silicon tetrachloride, dichlorodimethyl silane, phenyl benzoate, and divinylbenzene. The quantity of linking agent used to further combine the anionically-terminated species of this invention is derived from the actual content of active polymer chain ends in the polymerization mixture. Generally, a mole equivalent of linking agent to chain ends is required when the agent links polymer chain ends by termination reactions, as is the case for, e.g., dibromoethane and silicon tetrachloride. When non-terminating agents such as divinylbenzene are utilized to form star polymers, higher mole ratios are used, generally within the range of from about 3:1 to about 20:1 or higher. The preferred range is from about 3:1 to about 8:1.
The molecular weights of the condensed phase polymers may be varied to suit an individual application. When conjugated diene monomers are utilized, preferred molecular weights are generally in the range of from about 50,000 to about 200,000. In the case of additional linking of these copolymers via, e.g., divinylbenzene to form star polymers, molecular weights may exceed 1,000,000. Condensed phase block copolymers can have individual segment molecular weights that are typically preferred in the art, i.e., from about 5,000 to about 50,000 for the glassy or hard monoalkenyl aromatic phase and from about 50,000 to about 250,000 for the elastomeric or rubbery conjugated diene phase.
Both the conjugated diene-based condensed phase copolymers and the condensed phase block copolymers (and linked structures derived from each) are useful in preparing pressure sensitive adhesive (PSA) compositions. The block copolymers utilized for this purpose typically have a hard phase content of from about 10% to about 30% by weight (the remainder constituting the rubbery phase). The PSA compositions may be formed by mixing condensed phase copolymer or block copolymer and tackifying resin, either in solution, as dry granules, or by melt blending. Any of the resinous (or synthetic) materials commonly used in the art to impart or enhance the tack of PSA compositions may be used as a tackifier. Examples include rosin, rosin esters of glycerol or pentaerythritol, hydrogenated rosins, polyterpene resins such as polymerized β-pinene, coumaroneindene resins, "C5" and "C9" polymerized petroleum fractions, and the like. The use of such tack-modifiers is common in the art, as is described in the Handbook of Pressure-Sensitive Adhesive Technology edited by Donatas Satas (1982). Tackifying resin is added in an amount sufficient to provide a tacky composition. This is typically achieved by adding from about 50 parts to about 300 parts by weight of tackifying resin per 100 parts by weight of condensed phase copolymer.
The tackifier resin is selected to provide the copolymers of the invention with an adequate degree of tack to maintain in the resultant composition balanced PSA properties including high shear and peel. As is known in the art, not all tackifier resins interact with the same base elastomer in the same manner; therefore some minor amount of experimentation may be required to select the appropriate tackifier resin and to achieve optimum adhesive performance. Such minor experimentation is well within the capability of one skilled in the adhesive art. Along these lines, selection of the resin should take into account whether the resin associates with the thermoplastic styrene segment or the rubbery segments.
It is also within the scope of this invention to include various other components in the adhesive formulation. For example, it may be desirable to include such materials as plasticizers, pigments, fillers, stabilizers, and/or various polymeric additives.
The PSA compositions can be applied as solutions, dispersions, or as hot melt coatings to suitable flexible or inflexible backing materials to produce PSA-coated sheet materials. Flexible backings may be of any material which is conventionally utilized as a tape backing or may be of any other flexible material. Representative examples of flexible tape backing materials include paper, plastic films such as poly(propylene), poly(ethylene), poly(vinyl chloride), polyester [e.g., poly(ethylene terephthalate)], cellulose acetate, and ethyl cellulose. Backings may also be of woven fabric formed of threads of synthetic or natural materials such as cotton, nylon, rayon, glass, or ceramic material, or they may be of a nonwoven fabric such as air-laid webs of natural or synthetic fibers or blends of these. In addition, the backing may be formed of metal, metallized polymeric film, or ceramic sheet material. The PSA-coated sheet materials may take the form of any article conventionally known to be utilized with PSA compositions such as labels, tapes, signs, covers, marking indices, and the like.
The PSA compositions may be coated by any of a variety of conventional coating techniques such as roll coating, knife coating, or curtain coating. The PSA compositions may also be coated without modification by extrusion, coextrusion, or hot melt techniques by employing suitable conventional coating devices for this purpose. Because of the unique rheological characteristics of the condensed phase polymers and their blends with tackifiers, hot melt coating is particularly preferred. Primers may be utilized, but they are not always necessary.
EXAMPLES
The invention is illustrated by the following examples, wherein all parts are by weight unless otherwise indicated.
Nomenclature and Symbols
"S 10M is a shorthand designation for a polymer segment consisting of polystyrene(S) having a molecular weight of 10,000 (10M). Other polymer segments are identified in a similar manner with the first letter representing the first letter of the monomer of the polymer segment and the subscript indicating the molecular weight in thousands, e.g., 10M would mean a 10,000 molecular weight. As a further example, I 102M represents a polymer segment based upon isoprene which has a molecular weight of 120,000.
"br/n" refers to the fact that the polymer is randomly branched, indicated by "br", and "n" is an integer expressing the functionality of the condensing agent monomer. The term "br/n" is used as a prefix for the polymer segment modified. For example, S 10M -br/2-I 120M represents a block copolymer having a linear 10,000 molecular weight polystyrene segment (S 10M ) and a randomly branched 120,000 molecular weight polyisoprene segment (br/2-I 120M ).
Gel Permeation Chromatography
A Hewlett-Packard Model 1084B high performance liquid chromatograph equipped with two bimodal Zorbax PSM Kits (two columns at 60-S Å and two columns at 1000-S Å) was used for all determinations. Samples were dissolved in THF (AR grade) and filtered through a 0.5 micrometer polytetrafluoroethylene filter. Samples were injected at volumes of 10 microliters and eluted at a rate of 0.5 ml per minute through the columns maintained at 40° C. THF (AR grade) was used as the solvent. The differential refractometer detector was a Hewlett-Packard Model 1037A. The system was calibrated using polystyrene standards and employing a linear least squares fit. All GPC calculations were performed on an IBM 9000 integrator and all molecular weight averages are polystyrene equivalent molecular weights The molecular weight averages were calculated according to accepted practices. GPC test methods are further explained in Modern Size Exclusion Liquid Chromatography by W. W. Yau, J. J. Kirkland, and D. D. Bly, John Wiley and Sons, 1979.
PSA Test Methods
The test methods which were used to evaluate PSA-coated flexible sheet materials are industry standard tests. The standard tests are described in various publications of the American Society for Testing and Materials (ASTM), Philadelphia, Pennsylvania, and the Pressure Sensitive Tape Council (PSTC), Glenview, Ill. and are detailed below. The reference source of each of the standard test methods is also given.
Shear Adhesion
Reference: ASTM: D3654-78; PSTC-7
The shear adhesion strength is a measure of the cohesiveness or internal strength of an adhesive. It is based upon the amount of force required to pull an adhesive strip from a standard flat surface in a direction parallel to the surface to which it has been affixed with a definite pressure. It is measured in terms of time (in minutes) required to pull a standard area of adhesive coated sheet material from a stainless steel test panel under stress of a constant, standard load.
The tests were conducted on adhesive-coated strips applied to a stainless steel panel such that a 12.7 mm by 12.7 mm portion of each strip was in firm contact with the panel with one end portion of the tape being free. The panel with coated strip attached was held in a rack such that the panel forms an angle of 178° with the extended tape free end which is then tensioned by application of a force of one kilogram applied as a hanging weight from the free end of the coated strip. The 2° less than 180° is used to negate any peel forces, thus insuring that only the shear forces are measured, in an attempt to more accurately determine the holding power of the tape being tested. The time elapsed for each tape example to separate from the test panel is recorded as the shear adhesion strength.
Peel Adhesion
Reference: ASTM D3330-78 PSTC-1 (11/75)
Peel adhesion is the force required to remove a coated flexible sheet material from a test panel measured at a specific angle and rate of removal. In the examples, this force is expressed in Newtons per 100 mm (N/100 mm) width of coated sheet. The procedure followed is:
1. A 12.7 mm width of the coated sheet is applied to the horizontal surface of a clean glass test plate with at least 12.7 lineal cm in firm contact. A 2 kg hard rubber roller is used to apply the strip.
2. The free end of the coated strip is doubled back nearly touching itself so the angle of removal will be 180°. The free end is attached to the adhesion tester scale.
3. The glass test plate is clamped in the jaws of a tensile testing machine which is capable of moving the plate away from the scale at a constant rate of 2.3 meters per minute.
4. The scale reading in Newtons is recorded as the tape is peeled from the glass surface. The data is reported as the average of the range of numbers observed during the test.
EXAMPLES 1-23
The type and amount of each material used in each reaction, as well as the resultant polymer composition, are shown in Tables I-III for Examples 1-23.
A 5-liter, 5-necked reaction flask equipped with stirrer, condenser (under a small positive argon pressure from a gas bubbler), thermometer, and 3-septum inlet was used in the procedures which follow. All glassware and fittings were baked at 120+° C. for a minimum of 24 hours, were assembled under argon while hot, and then the entire apparatus was flamed under argon purge. Transfers of solvent and isoprene were made through stainless steel needles (through rubber septa) connected with polytetrafluoroethylene (Teflon®) tubing from a tared vessel or container using argon pressure. Styrene monomer was transferred through a rubber septum via syringe. Cyclohexane (AR grade) was dried by storage for 96+hours over indicating 4-6 mesh silica gel, and styrene monomer was dried by chromatography on a 1 cm×15 cm two-layered alumina (150 mesh)/silica gel (28-200 mesh) column. Purification of isoprene was initiated by stirring with KOH pellets for a minimum of two hours, followed by removal of the KOH by filtration. The isoprene was then refluxed over CaH 2 granules and, finally, was distilled and collected under argon in 500 g portions which were stored at 0°-5° C. Divinylbenzene (Matheson, Coleman, and Bell (MCB), 56% commercial grade) was purified by chromatography on a chilled, two-layered alumina (150 mesh)/silica gel (28-200 mesh) column (approximately 1 cm×15 cm) immediately before use. sec-Butyl lithium (Lithium Corporation of America, 12% in cyclohexane) was used as received from freshly opened bottles and was transferred via syringe through a rubber septum. Alkoxy- or haloalkylsilylstyrene condensing agents were prepared under nitrogen by the method described in the Detailed Description above, were distilled and sealed (in glass ampoules) under vacuum, and were then refrigerated at 0°-5° C.
In each example described below, the following preliminary glassware "sweetening" process was carried out prior to polymerization: 0.3 ml styrene was added to cyclohexane (an amount equal to the tabulated amount of cyclohexane minus the amount required to additionally prepare a 50% solution of the tabulated amount of isoprene), the mixture was then heated to 55°-60° C., and 3.0 ml of 1.3M sec-butyl lithium were added to obtain a bright orange color. The solution was then kept under reflux for about 45 minutes, cooled to 60° C., and back-titrated with cyclohexane saturated with methanol until the color just disappeared.
EXAMPLES 1 and 2
These examples demonstrate the preparation of polymers having random branching in the vinyl aromatic phase. Table I details reactant amounts and product compositions for polymers made via the following general procedure.
After the glassware "sweetening" process (while still at 60° C.), the full charge of styrene (as indicated in Table I) was added and titrated with 1.3M sec-butyl lithium to a pale yellow color. Then the full sec-butyl lithium initiator charge (as indicated in Table I) was added. Exactly one minute after the sec-butyl lithium addition, neat chloroalkylsilylstyrene condensing agent was added by injection through a rubber septum, and the reaction mixture was then stirred and kept at 60° C. for one hour. The reaction was continued by adding a 50% solution of isoprene (quantity shown in Table I) in cyclohexane which had been passed through a 4 cm×20 cm column of 28-200 mesh silica gel (minimum residence time of 30 minutes). The reaction mixture was then allowed to polymerize for three hours at 60°-65° C. During the initial exotherm, a cold water bath was necessary to prevent excessive reflux and loss of isoprene. Finally, star block copolymer was formed by adding divinylbenzene linking agent in one portion via syringe (through a rubber septum) and allowing polymerization over several hours at 60°-65° C. before termination with 1 ml of degassed methanol. The reaction flask was then allowed to cool to room temperature, was opened, and 3.5% by weight of solids of octadecyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate antioxidant and thermal stabilizer (Ciba Geigy Irganox® 1076) was immediately added as a polymer stabilizer. Next, precipitation of the polymer was achieved by slow addition of the polymer syrup to agitated isopropanol, followed by air drying or drying in a vacuum oven at 40° C. The yield was essentially quantitative, and weight average molecular weights were determined (by size exclusion gel permeation chromatography as described above)to be as shown in Table I.
Tables I-III display quantities of styrene and isoprene in grams, with amounts of initiator and condensing agent in millimoles. Although this appears to be inconsistent, it is done to show the relationship among reactant amounts, amount of initiator or condensing agent, and molecular weight.
TABLE I__________________________________________________________________________RANDOMLY-BRANCHED STYRENE No. of kg Condensing MW of.sup.1 MW Arms.sup.2Ex. cyclo- mmol g g iso- agent* Linking agent** AB Product perNo. Polymer hexane BuLi styrene prene Type mmol Type mmol × 10.sup.-3 × 10.sup.-3 Star__________________________________________________________________________1 (br/2-S.sub.10M -1,4-I.sub.60M).sub.n DVB 1.4 4.29 21.4 128.6 SSCL 2.14 DVB 12.8 101 853 82 (br/2-S.sub.10M -1,4-I.sub.60M).sub.n DVB 1.9 5.80 28.5 171.5 m-SSCL 2.90 DVB 17.4 126 918 7__________________________________________________________________________ *SSCL = 4(chlorodimethylsilyl)styrene mSSCL = 3(chlorodimethylsilyl)styrene **DVB = divinylbenzene .sup.1 Weight average molecular weight: polystyrene equivalent as determined by size exclusion gel permeation chromatography. .sup.2 Ratio of MW (product) to MW (AB)
EXAMPLES 3-14
These examples demonstrate the preparation of polymers having random branching in the rubbery diene phase Table II details reactant amounts and product compositions for polymers made via the following general procedure.
After the glassware "sweetening" process, the full charge of styrene (as indicated in Table II) was added, followed by the initiating dose of sec-butyl lithium. The temperature was maintained at 60° C. for one hour. The alkoxy- or haloalkylsilylstyrene condensing agent was then added to a 50% solution of isoprene (or, for example 12, butadiene) in cyclohexane which had previously been passed through a column of silica gel as described above. This solution was added to the reaction flask (by argon pressure) through two stainless steel needles (through rubber septa) connected with polytetrafluoroethylene Teflon®) tubing. The reaction temperature was maintained at 55°-60° C. at first by cooling and later by heating for three hours.
At this point, the reaction was terminated for examples 3, 4 and 10-14. Example 5 required the sequential addition of another charge of styrene (13 g) and maintaining the temperature at 55°-60° C. for another hour before termination. Star block copolymer was formed in Examples 6-9 by addition of divinylbenzene that had been purified as described previously. The temperature was then kept at 60° C. for several hours before termination. In all cases, the polymerization was terminated by the addition of 1 ml of degassed methanol followed by cooling, stabilization (by addition of 3.5% by weight of solids of Irganox® 1076), precipitation in isopropanol, and drying, as described above. Molecular weights were determined to be as shown in Table II.
TABLE II__________________________________________________________________________RANDOMLY-BRANCHED ISOPRENE No. of kg g g Condensing MW of.sup.1 MW Arms.sup.2Ex. cyclo- mmol sty- iso- agent* Linking agent** AB Product perNo. Polymer hexane BuLi rene prene Type mmol Type mmol × 10.sup.-3 × 10.sup.-3 Star__________________________________________________________________________3 (S.sub.10M -br/2-1,4-I.sub.120M) 1.7 4.29 42.9 257 SSCL 2.14 . . 137 .4 (S.sub.10M -br/3-1,4-I.sub.184M) 2.3 4.20 42 258 SSDCL 1.40 . . 480 .5 (S.sub.10M -br/3-1,4-I.sub.278M --S.sub.10M) 2.29 2.60 26 241 SSDCL 0.87 . . 589 .6 (S.sub.10M -br/2-1,4-I.sub.120M).sub.n DVB 1.5 3.91 39 234 SSCL 1.96 DVB 11.8 176 915 57 (S.sub.10M -br/3-1,4-I.sub.184M).sub.n DVB 2.0 4.20 42 258 SSDCL 1.40 DVB 8.4 176 1,114 68 (S.sub.5M -br/3-1,4-I.sub.184M).sub.n DVB 2.6 4.20 21 258 SSDCL 1.40 DVB 8.4 155 1,063 79 (S.sub.624 -br/3-1,4-I.sub.150M).sub.n DVB 2.3 5.40 3.37 280 SSDCL 1.80 DVB 18 132 1,142 910 S.sub.10M -br/2-1,4-I.sub.120M 2.0 3.33 33.3 200 SSMO 1.67 . . . Trimodal .11 S.sub.10M -br/2-1,4-I.sub.120M 2.0 3.33 33.3 200 SSF 1.67 . . . 212 .12 S.sub.10M -br/2-1,4-Bd.sub.120M 2.9 3.57 35.7 214.3.sup.3 SSCL 1.79 . . . 260 .13 S.sub.10M -br/4-1,4-I.sub.240M 2.1 3.33 33.3 200 SSTCL 0.833 . . . 570 .14 (S.sub.10M -br/2-1,4-I.sub.120M) 2.2 4.15 41.5 249 SSBr 2.07 . . . 149 .__________________________________________________________________________ *SSCL = 4(chlorodimethylsilyl)styrene SSDCL = 4(dichloromethylsilyl)styrene SSBr = 4(bromodimethylsilyl)styrene SSF = 4(fluorodimethylsilyl)styrene SSTCL = 4(trichlorosilyl)styrene SSMO = 4(methoxydimethylsilyl)styrene **DVB = divinylbenzene .sup.1 Weight average molecular weight: polystyrene equivalent as determined by size exclusion gel permeation chromatography .sup.2 Ratio of MW (product) to MW (AB) .sup.3 Butadiene was employed in place of isoprene
EXAMPLES 15-23
These examples demonstrate the preparation of polymers having point-branched structures. Table III details reactant amounts and product compositions for polymers made via the following general procedure.
After the glassware "sweetening" process, the full styrene charge (see Table III) was added, followed by the sec-butyl lithium initiating charge. A temperature of 55°-60° C. was held for one hour.*
*For Examples 16-23, the chloroalkylsilylstyrene condensing agent was injected at this point (in one portion by syringe), and the temperature was maintained at 55°-60° C. for another 45 minutes. Then a purified 50% solution of isoprene in cyclohexane was added as described above, and the reaction temperature was kept at 55°-60° C. for three hours, at first by cooling and later by heating. Finally, the divinylbenzene (or other) linking agent (as shown in Table III) was added and a temperature of 60° C. maintained for several hours.
*For Example 15, 3/4 of a purified 50% solution of isoprene in cyclohexane was added at this point, and the temperature was held at 55°-60° C. for 2 hours and 45 minutes. Then, the haloalkylsilylstyrene condensing agent was added and the same temperature range maintained for another 45 minutes, at which time the remaining 1/4 of the isoprene solution was added and the temperature again held at 55°-60° C. for 2 hours and 45 minutes. Lastly, the divinylbenzene linking agent was added and a temperature of 60° C. maintained for several hours.
For all of these examples (15-23), termination was achieved via addition of 1 ml of degassed methanol, and, after cooling to room temperature, the polymer was stabilized, precipitated, and dried as described for the previous examples. Molecular weights were as shown in Table III.
TABLE III__________________________________________________________________________POINT BRANCHING No. of g Condensing MW of.sup.1 MW Arms.sup.2Ex. kg cyclo- mmol g iso- agent* Linking agent** AB Product perNo. Polymer hexane BuLi styrene prene Type mmol Type mmol × 10.sup.-3 × 10.sup.-3 Star__________________________________________________________________________15 [(S.sub.10M -1,4-I.sub.38M).sub.3 1,4- 2.3 6.00 60 300 SSDCL 2.00 DVB 12 517 1,384 3 I.sub.38M ].sub.n DVB16 [(S.sub.5M).sub.2 -1,4-I.sub.60M ].sub.n DVB 1.9 8.00 40 240 SSCL 4.00 DVB 24 117 857 717 [(S.sub.5M).sub.3 -1,4-I.sub.107M ].sub.n DVB 2.3 8.61 43 307 SSDCL 2.87 DVB 17.2 239 1,261 518 [(S.sub.10M).sub.2 -1,4-I.sub.120M ] .sub.n DVB 2.3 4.00 40 240 αMSSCL 2.00 DVB 12 195 1,226 619 [(S.sub.10M).sub.2 -1,4-I.sub.120M ].sub.n DVB 2.3 6.20 53 372 mSSCL 3.10 DVB 27.9 277 1,553 620 [(S.sub.10M).sub.2 -1,4-I.sub.60M ].sub.2 DEPO 2.0 6.20 62 186 mSSCL 3.10 DEPO 0.221 209 436 221 [(S.sub.10M).sub.2 -1,4-I.sub.60M].sub.2 PB 2.0 5.20 52 156 mSSCL 2.60 PB 1.30 142 307 222 [(S.sub.10M).sub.2 -1,4-I.sub.60M ].sub.2 DBE 1.4 3.75 37.5 112.5 SSBr 1.875 DBE 0.94 138 322 223 [(S.sub.10M).sub.4 -1,4-I.sub.240M ] 2.2 3.33 33.3 200 SSTCL 0.83 -- -- 570 570 --__________________________________________________________________________ *SSCL = 4(chlorodimethylsilyl)styrene SSDCL = 4(dichloromethylsilyl)styrene αMSSCL = 4(chlorodimethylsilyl)-methylstyrene mSSCL = 3(chlorodimethylsilyl)styrene SSBr = 4(bromodimethylsilyl)styrene SSTCL = 4(trichlorosilyl)styrene **DEPO = 1,2.7.8 diepoxyoctane PB = phenylbenzoate DVB = divinylbenzene DBE = 1,2dibromoethane .sup.1 Weight average molecular weight: polystyrene equivalent as determined by size exclusion gel permeation chromatography .sup.2 Ratio of MW (product) to MW (AB)
EXAMPLE 24
This examples demonstrates the preparation of block copolymer which is randomly-branched in both the vinyl aromatic and diene phases:
br/2--S.sub.20M --br/2--1,4--I.sub.120M
Following the procedure for Example 1, a randomly-branched styrene polymer was produced from 2.0 kg cyclohexane, 6.0 mmol sec-butyl lithium, 60.0 g styrene, and 3.0 mmol 4-(chlorodimethylsilyl)styrene condensing agent. To the living polymeric anion obtained in this step was added (following the procedure set forth in Example 3) a 50% solution of 180.0 g isoprene in cyclohexane, to which 1.5 mmol 4-(chlorodimethylsilyl)styrene had been added. After stirring for 3 hours at 55°-60° C., the polymerization was terminated and the polymer cooled, stabilized, and collected as described above. The weight average molecular weight of the product was 290,000, with a dispersity of 1.16 (styrene equivalents).
EXAMPLES 25
This example compares the melt viscosity characteristics of condensed phase block copolymers over a broad range of shear rates with state-of-the-art linear triblock polymer, Kraton® 1107 (Shell Oil Co.), MW=175,000 (based on a 3M determination). Three different types of condensed phase block polymer are compared. The data are shown in FIG. 1. The melt viscosity was determined using a Siegloff-McKelvey capillary viscometer at 170° C. L/D=51. The melt viscosity for the polymer of Example 3, shown as line B, which has incorporated a bifunctional condensing reagent, was found to be an order of magnitude lower than the linear control sample, Kraton® 1107, shown as line D. The polymer of Example 4, which incorporates a trifunctional condensing reagent in the copolymerization of the isoprene segment, has a melt viscosity (shown as line C) only slightly higher than the control, even though the molecular weight of the condensed block polymer is about 2.5 times greater. When the condensing reagent is copolymerized in the vinylaromatic segment, a remarkable reduction in melt viscosity is observed The data show that for the polymer of Example 1, shown as line A, the viscosity characteristics are substantially the same as for the control polymer, even though Example 1 is a condensed phase star block polymer with a molecular weight of about 853,000 (about five times the control). The effect persists when both polymers are tackified with 100 phr (parts per hundred rubber) Wingtack Plus® (Goodyear Tire and Rubber Co.) and their melt viscosities compared, as shown in FIG. 2. ("At" refers to the viscosity data for the tackified polymer of Example 1 and "Dt" refers to tackified Kraton® 1107 block copolymer control.) In addition to having a very low melt viscosity for its molecular weight, the "condensed" styrene phase star polymer also shows a low dependence of viscosity on shear rate.
EXAMPLE 26
This example illustrates the rheological effects of random branching in the rubbery or diene phase of block polymers.
Condensing together growing diene polymer chains in a more or less random fashion during an anionic polymerization leads to polymers with unusual rheological properties when compared to conventional, linear materials. Comparison of a linear triblock polymer, Kraton ® 1107 (Shell Chemical Company), with a condensed diene phase styrene-isoprene block polymer, S 10M --br/2--I 120M (Example 3), using steady shear viscosity measurements performed .at 190° C. on a Rheometrics Mechanical Spectrometer showed that, for the experimental condensed block polymer, the steady shear viscosity has a relatively low value of 10 2 Pa·s which is shear rate-independent over the range shown in FIG. 3. (In FIG. 3, "D" refers to the Kraton® 1107 block copolymer control and "B" refers to the polymer of Example 3.) This effect would be an advantage in hot melt coatings, since better control and uniformity could be achieved due to the Newtonian-like behavior of the polymer.
EXAMPLES 27 and 28
This example demonstrates the properties of pressure-sensitive adhesive compositions derived from point-branched and randomly-branched block polymers.
The novel polymers of this invention were formulated into pressure-sensitive adhesives (PSAs) by solution blending in toluene the branched or "condensed phase" block polymer, a synthetic hydrocarbon tackifier resin, and 3 phr (parts per hundred rubber) Irganox® 1076 stabilizer. These adhesive compositions were knife-coated at a thickness of 25 micrometers onto primed 38-micrometer polyethylene terephthalate film, were dried for 5 minutes at 60° C., and were then conditioned for 24 hours at 21° C. and 50% relative humidity. Tape testing was carried out according to the test methods previously described, and the results are detailed in Tables IV and V below. In addition, Table V ("Randomly-Branched Block Polymer PSAs") includes data for analogous linear (unbranched) diblock polymer PSA compositions as comparative examples. The data shows that a significant improvement in PSA properties is observed when a "condensing" reagent is copolymerized to form a branched or "condensed" polymer structure.
EXAMPLES 27
TABLE IV______________________________________Point-Branched Block Polymer PSAsPolymer(Previous Tackifier Peel Shear.sup.2Ex. No.) Tradename (phr) (N/100 mm) (RT, Min.)______________________________________15 Wingtack Plus ®.sup.1 80 107 5,000+ 100 120 5,000+ 120 131 5,000+17 Wingtack Plus ® 80 107 4,503 100 116 10,000+ 120 129 10,000+18 Wingtack Plus ® 80 99 5,000+ 100 123 5,000+ 120 136 5,000+______________________________________ .sup.1 Available from Goodyear Tire & Rubber Company .sup.2 + indicates that test was terminated at this point.
EXAMPLE 28
Excellent shear and peel adhesion characteristics are also obtained with randomly-branched block polymers when formulated into PSAs, as shown below.
TABLE V______________________________________Randomly-Branched Block Polymer PSAsPolymer(Previous Tackifier Peel Shear.sup.3Ex. No.) Tradename (phr) (N/100 mm) (RT, Min.)______________________________________1 Wingtack Plus ®.sup.1 80 99 7,100+ 100 127 7,100+ 120 151 7,100+ Escorez ® 5300.sup.2 80 109 7,100+ 100 134 7,100+ 120 151 7,100+3 Wingtack Plus ® 80 103 3,792 100 142 4,000+ 120 166 3,847 Escorez ® 5300 80 109 4,100+ 100 120 4,100+ 120 74 4,100+4 Wingtack Plus ® 80 120 10,000+ 100 116 10,000+ 120 120 10,000+5 Wingtack Plus ® 80 88 5,000+ 100 99 5,000+ 120 114 5,000+6 Wingtack Plus ® 80 99 6,000+ 100 118 6,000+ 120 112 6,000+ Escorez ® 5300 80 107 6,000+ 100 118 6,000+ 120 120 6,000+7 Wingtack Plus ® 80 63 7,500+ 100 96 7,500+ 120 147 7,500+8 Wingtack Plus ® 80 125 2,594 100 151 1,498 120 199 (coh).sup.4 753s.sub.10M --I.sub.60M Wingtack Plus ® 100 127 3s.sub.10M --I.sub.180M Wingtack Plus ® 100 116 8______________________________________ .sup.1 Available from Goodyear Tire and Rubber Company .sup.2 Available from Exxon Chemical Company .sup.3 + indicates that test was terminated at this point .sup.4 (coh) indicates cohesive failure
EXAMPLES 29
Pressure-sensitive adhesives formulated as in Example 28 have improved high temperature shear performance compared to their linear counterparts. As shown in Table VI, shear adhesion dramatically improves as the condensing reagent is copolymerized in the isoprene phase. There is also a significant improvement in shear adhesion when the polymers are further linked with vinylbenzene to form a condensed phase star polymer.
TABLE VI__________________________________________________________________________Shear Adhesion at 66° C.For PSA Formulations.sup.2 Time to failure.sup.1 Melt Viscosity at load (Pa · s × 10.sup.-2) (minutes (at 100 sec.sup.-1Polymer at 66° C.) shear rate)Structure Ex. 200 g 500 g 1000 g 170° C. 190° C.__________________________________________________________________________S.sub.10M --I.sub.120M -- 2 <1 <1 2.35 0.98S.sub.10M -br/2-I.sub.120M 3 1184 20 3 1.8(S.sub.10M --I.sub.120M)DVB -- >10,000 1478 59 7.7 6.5(S.sub.10M -br/2-I.sub.120M)DVB 6 >10,000 4080 350 4.2 2.0S.sub.10M --I.sub.180M -- 1712 13 <1 2.85S.sub.10M -br/3-I.sub.184M 4 3267 545 108 3.2 2.5S.sub.11.5M --I.sub.145M --S.sub.11.5M Control.sup.3 2068 279 48 2.85 2.7__________________________________________________________________________ .sup.1 Shear adhesion failure, 12.7 mm × 12.7 mm overlap, 25micrometer coat thickness on polyethylene terephthalate, all failures were cohesive .sup.2 Tackified with 100 phr Wingtack Plus .sup.3 Commercially available Kraton ® 1107 block copolymer
EXAMPLE 30
This example illustrates the tensile properties of condensed-phase diblock polymers of the invention. Polymer films were prepared by casting solutions of the polymer in toluene (30% solids) onto polytetrafluoroethylene (Teflon®) sheets or silicone release liners using glass cylinders as spacers. Solvent was allowed to evaporate over a period of 7 days. The sample was further dried in a vacuum oven at 40° C. for 48 hours. Stress-strain measurements were made using a modification of ASTM D 412 with a micro-dumbbell and 2 in./min. crosshead speed. An Instron Universal Testing Machine was used to measure the stress-strain properties of the samples. Elongation was estimated by measuring the distance between bench marks on the sample. The stress was recorded continuously on a chart recorder.
TABLE VII______________________________________Tensile Properties of Condensed-Phase Diblock PolymersExample 300% Modulus Tensile ElongationNumber (psi) Modulus (psi) (%)______________________________________ 3 75 390 110010 131 335 102511 150 594 125024 200 1000 1200Kraton ® 1107* 112 2724 1300______________________________________ *Kraton ® 1107 is a linear styreneisoprene triblock polymer from Shel Oil Company.
While this invention has been described in terms of specific embodiments, it should be understood that it is capable of further modifications. The claims herein are intended to cover those variations which one skilled in the art would recognize as the chemical equivalent of what has been described here. | The present invention relates to elastomeric copolymers and block copolymers, e.g., based upon styrene/isoprene, having a novel condensed phase structure wherein polymer branches occur along the polymer backbone, either at a predetermined location or at random locations. The polymers are made by a method which comprises the step of reacting, under polymerization conditions, hydrocarbyl lithium initiator, at least one anionically polymerizable compound, and an organometallic- substituted styrene condensing agent. The reactants may be added simultaneously to produce a copolymer with polymer branch segments randomly located along the polymer backbone or sequentially to produce a copolymer with branches located at the same predetermined location along the polymer backbone. The resultant polymers may be further reacted with a linking agent to form multi-arm copolymers. | 2 |
BACKGROUND OF THE INVENTION
This application is related to U.S. application Ser. No. 924,775 and 924,639.
The invention concerns belts or straps, more particularly elevator conveyor belts. It relates to a method and a device for splicing the ends of belts, either to increase their length, or to make them endless by joining the belt to itself in a manner which is reliable during operation. The fastening device as well as the process will be described below, as an example, for application to an elevator belt, with the understanding that they are not limited to this use.
One conventional method of splicing the ends of belts is hot splicing after the ends of the reinforcing material have been interlaced.
Various forms of these hot splicing techniques are described in a number of patents, such as DE No. 1,165,354 of Franz Clouth Rheinische Gummiwarenfabrik; FR No. 74.03141 and DE No. 907,996 of Continental Gummi-Werke; FR No. 1,395,634, FR No. 1,582,190 and FR No. 1,440,605 of Pneumatiques, Caoutchouc Manufacture et Plastiques Kleber Colombes; and U.S. Pat. No. 173,686 of Goodyear Tire and Rubber. One method is recommended in German standard DIN 22131. Another method is described by Mr. Gozdiff of Goodyear in a paper entitled "Factors relating to vulcanized splice reliability for steel cable reinforced conveyor belting", delivered to the 125th Meeting of the Rubber Division, American Chemical Society, in Indianapolis on May 8-11, 1984. Finally, an article by H. P. Lachmann entitled "A survey of present-day conveyor belt technology", published in Bulk Solids Handling volume 4, number 4, December 1984, reviews the different technologies that can be used. Other proposals have been described in, for example, U.S. Pat. Nos. 2,446,311 and 3,093,005.
Examples of the prior art in hot splicing are illustrated in FIG. 1. There are, however, conditions which make hot splicing techniques inapplicable: for example the length of such a splice may be incompatible with the space available in the sheath or alongside the elevator, or again the mechanical strength may become insufficient to guarantee trouble-free operation of the elevator if the temperature of the products transported or that of the gases circulating in the sheath is greater than 100° C.
Specifically, in the case of interlacing of metal cords, the two ends of the belt(s) are bonded together by the rubber mixture separating the ends of the cable(s). It is known, however, that as the temperature increases, the mechanical properties of elastomer-based mixtures decrease; the same applies to the bonding forces between the rubber and the metal. As a consequence, the tensile strength of such a splice decreases as the temperature rises.
Taking into account the risks encountered with a splice using hot adhesion and interlacing of metal cords, handling engineers have suggested replacing the adhesive bond with a mechanical bond designed to clamp the two ends of the belts(s) against one another. These techniques are referred to as "fastening", and are described, for example, in French Pat. No. 1,320,222 of Pneumatiques, Caoutchouc Manufacture et Plastiques Kleber Colombes, or in advertising materials of specialized companies such as Goro or Flexco.
Other mechanical fasteners are described in, for example, U.S. Pat. Nos. 2,447,855 and 1,918,255.
The compression force is exerted by metal flanges which are passed through by clamping bolts. The principle applied in mechanically splicing the ends of a belt or belts is theoretically more satisfactory than the hot-adhesion process, but an analysis of phenomena associated with operation of this type of device shows that there is only a slight improvement in operating reliability. This is because the lateral plates have a tendency to move away from one another under the tensile force exerted on the two ends of the belt. To remedy this problem, two lines of bolts are generally used to clamp the plates, with the line of bolts placed closest to the tension zone being designed to limit movement of the plates.
FIG. 2 illustrates conventional fastening techniques such as described in U.S. Pat. Nos. 4,489,827, 1,803,354, 2,330,434, 2,330,435, 3,618,384, and 4,450,389 and provide an example of changes which occur during operation, in terms of distribution of pressure over the belt ends.
When the fastening device is initially clamped, pressure distributed uniformly over the entire extent of the two clamped ends. When operation begins, the lateral parts are displaced, which tends to decrease the pressure in zone X and increase that in zone Y. As a result of the increased pressure, the rubber mixture located in zone Y tends to be expelled and to creep, i.e. rubber is displaced from the most highly compressed zones towards those least compressed. The effect of this creep is to encourage the clamping plates to move closer together in zone Y, which accentuates the effect.
As confirmation of this analysis, it is commonly observed that the second line of bolts has completely loosened, which proves that the pressure effect exerted on the ends of the belt(s) is due not to the bolts but to a rotary movement of the clamping plates. Since the clamping force in zone X has decreased considerably, the strength of such a clip fastener consists only of the retention of the metal cords in zone Y and the frictional forces existing in zone X between the belt and each of the clamping plates. When zone Y is unclamped, an examination of the ends of the belt(s) in said zone shows that the tensile stress has been so high that there has been local destruction of the rubber mixture and of the bond between the rubber and the metal cords. This fact makes the strength of such a clip fastener very problematical, especially when this mechanical effect is combined with the effect of temperature, since it is well known that increased temperature accelerates and facilitates the creep of elastomer-based mixtures, and decreases the strength of the bond between said mixtures and steel cords.
To remedy this problem, it is possible to attempt to increase the pressure exerted by the lateral plates by locking the ends of the metal cords.
Patent DE No. 2,341,992 of Bernhard Beumer Maschinenfabrik describes such a solution, in which each metal cord is stripped at its end of its rubber covering, and said end is inserted into a clamping device using screws. Such a technique, time-consuming and difficult to implement, presents a further risk due to the design of the metal cord clamping zone: if the clamping pressure is not properly controlled, there is a definite risk of cutting the metal cord, which would nullify the anticipated effect. In addition, the screws have a tendency to loosen under the action of vibration and temperature, and therefore require constant monitoring.
A similar solution of the type described above using bores steel balls to lock the ends of metallic cables is also proposed in U.S. Pat. No. 3,105,390.
A different solution, used in particular to lock pretensioning cords in prestressed structures, involves stripping the ends of the metal cords, unstranding them, i.e. untwisting the constituent strands to spread out the end, and pouring around it a metal with a low melting point. This technique is highly reliable when it can be used, but pouring the molten metal requires that the clip fastener be placed in a vertical position, which implies either that one of the drums of the elevator can be moved - which is not always possible--or that the clip fastener can be placed at the top of the elevator, although pouring molten metal onto the ends of metal cords at a height of several dozen meters is tricky and even dangerous. In addition, such a device is practically non-removable, which does not facilitate maintenance of the elevator or replacement of the belt.
The object of the invention is therefore a fastening device for splicing belts, and more particularly belts for bucket elevators, which comprises a reinforcement made of manmade fabric or metal cords. Other objects of the invention are the process for creating splices using the device described, and application to an elevator conveyor belt.
The fastening device which is the object of the invention makes it possible to create, using a method that is as simple as conventional splices and is completely safe since there is no handling of hot products or adhesives or heating equipment, a splice between two adjacent ends of two belts to produce a longer belt, or between the two ends of a single belt to produce an "endless" item, ready for operation on a conveyor or elevator.
The device, which requires only simple preparation of the ends, acts on the one hand by locking by means of a loop created around a locking core, and on the other hand by means of mechanical clamping of said ends over the greatest possible length.
This fastening device comprises, on the one hand, two central plates, designed solely for installation and serving to support the ends of the belts(s), to which are attached, on the upper part, two installation wedges allowing the assembly to be aligned, and on the other hand, two locking cores making it possible to create loops in the ends of the belt(s) and, finally, two lateral clamping parts each fitted with a ball joint.
This device acts like a pivoting self-clamping clip by means of its various component parts, with the lateral clamping parts acting to clamp the belt by means of through bolts.
The characteristics and variants of the invention will be better understood by reading the description below taken in conjunction with the accompanying.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 illustrate fastening devices constructed in accordance with the prior art;
FIG. 3 shows the fastening device used for splicing two belts or making one belt into an endless belt;
FIGS. 4a-4e show details of certain component elements of a particular embodiment of the fastening device;
FIG. 5 explains how the belt is installed on the fastening device;
FIG. 6 illustrates the splicing process using the fastening device which is the object of the invention;
FIGS. 7a-7b show a particular arrangement making it possible to improve the quality of the splice;
FIGS. 8a-8b illustrate the self-clamping operating principle of the fastening device which is the object of the invention.
DETAILED DESCRIPTION
Referring now to the drawings wherein like reference numerals are used throughout the various views to designate like parts and, more particularly, to FIG. 3, according to this figure, a fastening device, in an assembly position, includes two central support plates 1 to which are mechanicaly attached, by attaching means 10, two wedges 2 for installing and aligning a belt. The fastening device also includes two locking cores 3 of a generally cylindrical cross section and two lateral clamping parts provided with a ball joint 5. While the component parts of the fastening device can be made of steel thereby leading to a total weight for the fastener of approximately 80 kg per meter of length.
Considerable lightening can be achieved by making locking cores 3 and central support plates 1 of a lower-density material, such as duralumin, a composite material with a rigid matrix, or a rubber-based mixture reinforced wtih fabric or metal fillers or fibers. In the case where duralumin is used, the weight of the fastener is decreased to approximately 59 kg per meter of length, which increases the advantage of this type of fastening in terms of the conveyor's energy budget.
FIG. 4a shows one of the central plates 1 with, in its upper part, a hole 6 for mechanical attachment of the installation and alignment wedges and, in its lower part, a hole 7 for passage of the through bolts with a recess 8 which will allow the rubber covering to expand in the vicinity of the zone where the through bolts clamp and, along the same axis, a hole 31 to retain the loop before clamping.
FIG. 4b shows one of the possible shapes for the installation and alignment wedges 2, comprising a hole 9 which will allow the belt to be attached between edge 2 and central support plate 1. The holes 6 in said plate 1 and 9 in the installation and alignment wedge 2 will accommodate the assembly device 10 in FIG. 3.
In the example illustrated, installation and alignment wedge 2 consists of an L-shaped part 11 in which angle A is 90°, and a welded base element 12 with a tapped hole 9 for attachment to central support plate 1.
FIG. 4c illustrates, in cross section, a particular embodiment of one of the lateral clamping parts 4, composed of a stiffener 13 and a clamping distribution sheet 14 to which is attached, by welding, the ball-joint support 15. Lateral clamping part 4 comprises a hole 16 through which the through bolts pass, and a recess 17 to allow the rubber covering to expand in the vicinity of the zone where the transverse bolt clamps.
FIG. 4d and 4e illustrate, in cross section, the ball-joint device 18 which will be inserted into ball-joint support 15 on lateral clamping part 4. It consists of a half-cylinder 19 comprising two lateral positioning shoulders 20, and through it passes a hole 21 for the through bolts.
FIG. 5 illustrates the way in which the fastening device is installed on a belt end, as a unit, within the conveyor or outside it.
The process begins with creation of the loop. To do this, end 22 of belt 23 being assembled is placed against central plate 1, and installation and alignment wedge 2 is attached by means of mechanical elements 10 to said central plate through end 22 of the belt. Locking core 3 is then placed against installation wedge 2 and the loop is formed around said locking core using a forming tool. Clamping part 4 is put into place and retained with clamps on central part 1, then attached with installation nuts and bolts 31.
FIG. 6 illustrates the belt splicing process using the fastening device which is the object of the invention. After the loops have been formed, resting against central pars 1, the two parts are placed back to back and mechanically clamped with through bolts 24. The expansion of the rubber coatings produced when through bolts 24 are inserted into the belt is accommodated by recesses 8 in central support plates 1 and 17 in lateral clamping plates 4. An elastic welt 25, made of rubber comprising fabric or metal reinforcements, is added to the fastening device to allow it to pass over rollers and drums without impact and, moreover, without noise.
In order for ends 22 of the belt(s) being assembled to be wound without excessive stress around locking cores 3, said cores must have a sufficiently large diameter. The minimum value is not critical with a textile-reinforced belt which is fairly flexible, but for a belt whose reinforcement consists of metal cords, the diameter of said locking cores 3 must be at least 16 times the diameter of the metal cords, and preferably 20 times.
To prevent dust contamination or chemical attack, it is possible to finish off the splice by applying a terminal welt 27 placed on a sheet of insulating material 28, for example a cellular material, and affixed to the belt with a mechanical clamping device 29.
To extend this protection against contamination to the entire spliced zone, it is possible to place on the upper part of the device a cap (not shown), most often made of sheet metal, and to ensure complete watertightness by applying a putty or any other formable material.
In order to increase the mechanical strength and therefore the efficacy of the splice by limiting the number of breaks in the reinforcing elements in the zone where the bolts pass through, it is possible, during installation, to arrange said reinforcing elements 26 in such a way that they are diverted from their initial path around the shafts of said bolts 24 as diagrammed in FIG. 7. This is done with a suitable tool, for example one with a tapered point.
FIG. 7a illustrates how the reinforcing elements are diverted when said reinforcement consists of textile or metal cords 26, initially parallel, forming a ply.
FIG. 7b shows the same effect in a reinforcing element comprising a weft 26 composed of textile or of metal cords, and a warp 32 also composed of textile or of metal cords. The threads are then diverted longitudinally along weft 26 and transversely along warp 32.
FIG. 8 illustrates the principle and the operation of the self-clamping system.
FIG. 8a shows the orientation of the forces. The tensile force Ft which acts on the body of the belt gives rise to a reaction force Fr in relation to point E.
FIG. 8b illustrates the same effect on a cutaway view of the fastener. The tensile force Ft which acts on the body of the belt 23 produces a compression represented by forces Fc in the end of belt 22 which tend to press together the two parts of the belt thanks to its ball-joint device 5; lateral clamping part 4, by pivoting about point E, then exerts a reaction force Fr on the return side of the loop in belt 30, which gives rise to a series of forces f1, f2, f3 ... which progressively increase up to point G where the end of the belt is supported on central plate 1, thereby producing self-clamping of the end of the belt around locking core 3.
Obviously, clamping force Fs of the transverse bolt must be greater than the sum of tensile force Ft and reaction force Fr.
As apparent from the above description and attached figures, the fastening device of the present invention has a number of advantages as compared with prior art devices. More particularly, the fastening device of the present invention is applicable both to textile-reinforced belts and to those belts in which the reinforcement consists of metal cords. Moreover, there is no need to prepare the end of the belt and it can be applied flat, off the conveyor, without requiring any complex tool. Furthermore, a number of cut reinforcing elements can be reduced which thereby increase the strength of the splice, and the process of gluing the ends of the belt is eliminated thereby also dispensing with the requirement for additional equipment such as, for example, vulcanization presses, molding parts of build-up devices.
Additionally, by virtue of the features of the present invention, the fastening device may be reduced in weight by making the locking cores and/or the central parts out of a like metal or composite materials thereby reducing the overall energy cost per unit, and maintenance problems during operation may be reduced since possible creep of the rubber into the clamping zones is compensated for by a pivoting of the lateral clamping parts.
Furthermore, the present invention enables an increase in reliability due to the self clamping effect exerted by the ball-joint device in the lateral clamping parts. | Fastening device for splicing belts comprising reinforcing elements made of manmade fabric or metal cords, characterized by the fact that it consists of two central support plates, two installation and alignment wedges, two locking cores which make it possible to create loops in the ends of the belt(s), and two lateral clamping plates each equipped with a ball joint, these various component elements making it possible for said device to operate in a self-clamping pivoting manner. Applicable to straps and belts and, more particularly, to conveyor belts for elevators. | 8 |
CROSS RELATED APPLICATION
This application claims the benefit of application Ser. No. 61/263,905 filed Nov. 24, 2009, which is incorporated in its entirety by reference.
BACKGROUND OF THE INVENTION
The present invention generally relates to methods and systems for producing a pulp from lignocellulosic material, such as wood chips, using chemical cooking techniques. The pulp may be produced in a continuous flow chemical digester vessel.
Lignocellulosic material, such as wood, is conventionally comminuted into wood chips before being cooked in a digester vessel, such as a continuous or batch vessel. The size of the wood chips has primarily been set to enhance digester performance and, particularly, to avoid plugging the bottom of the digester vessel with collapsed chips.
Softwood chips are typically cooked to Kappa numbers of 20 to 33 and hardwood chips are cooked to a Kappa numbers of 15 to 20. The Kappa number indicates the residual lignin content of wood pulp. At these conventional Kappa numbers, thin chips, e.g., chips having a thickness of less than 7 mm, become soft and easily compressed at the bottom of the digester vessel.
Compressed, soft thin chips become densely packed at the bottom of the digester vessel, plug the bottom and impede the flow of wash liquor through the chips in the wash zone of the digester vessel. When compression of soft chips is severe, the bottom of the digester becomes choked with chips such that insufficient liquid flows through the chips in the column of chips in the vessel. Under such conditions, a mass transfer problem can arise in which the chips no longer move uniformly downward to the chip discharge outlet at the bottom of the vessel.
Compressed soft, thin chips can form chip agglomerations that plug and block chip flow down through the lower portion of a digester vessel. Channels may form in the thin chip agglomerations that allow some chips to flow to the bottom of the vessel while other chips are bound in the agglomeration. The channels are not desired as they are inconsistent with uniform chip flow down the digester vessel and allow the agglomerations of chips to remain in the vessel for extended periods.
Chip agglomerations may inhibit wash liquids intended to flow through the chips to remove used or spent cooking liquor (black liquor) and lignin prior to exiting the chips/pulp exiting the digester. An agglomeration of cooked thin chips at the bottom of a digester vessel can inhibit the removal of black liquor before the chips are discharged from the digester vessel. An agglomeration of cooked thin chips may also plug or block the screens in the sidewalls of the digester vessel.
A high content of very thin chips and pin chips (collectively referred to as “small chips”) can cause problems in an upper portion of a digester vessel. Small chips may plug the screens in the upper regions of the digester vessel. Plugged screens prevent the extraction of liquor from the upper portion of the digester vessel.
When the vessel becomes excessively compacted, the continuous cooking operation is temporarily stopped and cold liquor added to the bottom of the digester to cool down, break up and remove the agglomeration of chips. The lower pulp production rate or temporary halt to chip production results in a reduction in the pulp production realized by the mill and higher maintenance costs.
Due to the difficulty in processing thin and small chips, an average chip thickness of 8 mm is a standard minimum sized chip to be formed at a mill for use in a continuous digester vessel. When the average chip length is 22 mm (millimeter) to 30 mm in length, the thickness of the chips is generally less than 8 mm, with 85% to 90% of the chips having a thickness in a range of 8 mm to 2 mm.
Chip screens in the chip feed system are commonly used to select chips having an acceptable thickness. The screens may be positioned at an inlet to the chip bin for the digester vessel. A chip screen may have first screen of 8 mm slots and second screen having 7 mm diameter holes. Chips are selected as those that pass through the first screen and are retained by the second screen. Screening chips is a technique for classifying the chips. Chip classification is commonly done according to a SCAN-CM 40:01 chip size distribution analyzing method. According to this method, acceptable chips for continuous digesting are those that pass through an 8 mm slot and are retained on a tray with 7 mm holes.
Conventional wisdom is that large amounts of thin and small chips should not be processed in a conventional continuous digester vessel. Thin and small chips, such as pin chips and sawdust, are conventionally processed in a Pandia Digester offered by GL&V, Bauer M&D digesters and Metso pin chip processes, or a specially adapted Kamyr® digester.
To avoid the problems associated with small and thin chips, the conventional wisdom has been that chips for a conventional continuous digester should be sufficiently large, e.g., average chip thickness of 8 m and lengths 25 to 30 mm for softwood and 22 to 24 mm for hardwood, to avoid excessive softening the chips in the digester vessel.
BRIEF DESCRIPTION OF THE INVENTION
There is a need for a method and system for chemically digesting thin chips, such as in a continuous flow digester vessel. Such a method and system may avoid or minimize the difficulties conventionally associated with cooking thin chips in a vertical continuous digester vessel. It would be desirable if the method and system for digesting thin chips minimized the halts to digester production which are needed to break up an agglomeration of soft chips plugging the digester.
A method has been conceived and is disclosed herein to cook thin chips in a continuous digester vessel comprising: introducing a flow of thin chips in which at least 85% of the chips have a thickness of no greater than 6 mm; adding liquor to the chip bin or to a chip transport passage extending from the chip bin to an upper inlet of the continuous digester vessel; injecting steam or other heated fluid to an upper region of the digester vessel to elevate a cooking temperature of the chips in the vessel to at least 130 degrees Celsius; cooking the chips in the vessel as the chips flow downward through the vessel without substantial extraction or introduction of liquor in the cooking section of the vessel; injecting wash liquid to a lower region of the vessel; extracting at least the wash liquid through a wash liquid extraction screen in the lower region of the vessel and above the injection of the wash liquid, and discharging the cooked thin chips as pulp from the lower region of the vessel.
Substantially all of the white (cooking) liquor may be added in the chip bin and the chip transport passage and substantially no white liquor is added in the digester vessel. The chips and cooking liquor in the digester vessel flow in a uniformly downward direction through the vessel to the wash liquid extraction screen. Substantially the entire height of a chip column in the digester vessel may be maintained at a temperature of at least 130 degrees Celsius and at a pressure of at least 2 bar gauge.
At least 85% of the chips may have a thickness greater than 2 mm. The pulp discharged from the digester vessel may have a Kappa number of at least 50 for softwoods and at least 25 for hardwoods. The steam or the other heated fluid injected to the digester vessel may be at a pressure of at least 2 bars gauge.
An apparatus to pulp thin wood chips has been conceived and is disclosed herein comprising: a chip screen receiving chips of comminuted cellulosic material, the screen assembly including a screening assembly which outputs thin chips in which at least 85% of the chips have a thickness of no greater than 6 mm; a chip bin and conveyor assembly receiving the thin chips output from the chip screen, the chip bin assembly including a chip bin having an inlet to receive white liquor and said chip bin having an operating mode in which a lower portion of the chip bin is flooded with white liquor while thin chips move through the chip bin to a discharge outlet of the chip bin, and the chip bin and conveyor assembly including a conveyor discharging the thin chips to a transport conduit; a continuous digester vessel having an chip inlet at an upper region of the vessel coupled to the transport conduit, a cooking zone extending vertically from the upper region of the vessel to a wash zone, a wash zone extending from the cooking zone to a bottom region of the vessel and a pulp discharge outlet in the bottom region; an inlet to receive steam or other heated fluid at the upper region of the inlet, an upper region of the digester vessel to elevate a cooking temperature of the chips in the vessel to at least 130 degrees Celsius; and the wash zone including a wash inlet to digester vessel to receive wash liquid and a screen assembly proximate to the wash inlet, the screen assembly including a screen adjacent and a wash filtrate chamber on a side of the screen adjacent the chips in the wash zone.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of an exemplary embodiment of a method and system for digesting thin chips.
DETAILED DESCRIPTION OF THE INVENTION
A new cooking method and system have been conceived and is disclosed herein for cooking thin chips in a continuous chemical digester, and useable with various chemical cooking process, such as kraft and soda process. Cooking thin chips with the method and system disclosed herein may solve or reduce the mass transfer problems associated with thin chips in conventional kraft continuous digester cooking.
Thin chips may be comminuted lignocellulosic chips in which 85% to 90% of the chips have thicknesses of 2 mm to 6 mm. The thin chips can be generated by adjusting conventional chippers in a mill supplying the chips and by adjusting conventional screening devices that screen the chips entering the chip bin for a continuous digester.
The cooking conditions in a continuous digester vessel for thin chips may be less severe than the conditions typically used to cook conventional thicker chips. For example, the digester vessel may product pulp from softwood thin chips having Kappa numbers of at least 50 and be in any of ranges of 50 to 100, 50 to 80, and 60 to 75. Similarly, pulp from hardwood thin chips may have Kappa numbers of at least 25, and be in a range of 25 to or be above 50. These high Kappa numbers may be achieved even though the period for impregnating the chips with a cooking liquor is short. The chips may be impregnated with white cooking liquor in the chip bin and thereby avoid a separate chip impregnation device.
The cooking of thick chips is presently believed to be mass transfer limited in the early stage of the cooking. Mass transfer relates to the transfer of cooking chemicals into the chips and to the fibers within the chips. Mass transfer can be improved by increasing temperature, using thinner wood chips and higher OH-concentration. Higher temperatures can be problematic because they may cause a higher consumption of OH. The inventors propose using thinner wood chips and high OH-concentration as a practical approach to improving the mass transfer of cooking chemicals to the fibers in the wood chips.
The conventional problems of thin wood chips becoming too soft in a chemical digester vessel appear to be due, at least in part, to excessive permeability of thin chips in the digester vessel. The permeability of chips depend on the size of the chips, porosity of the chips, and the Kappa number of the chip. A lower Kappa number may provide for lower permeability of the chip, and a higher Kappa number may provide for a higher permeability of the chip.
A chip feed system, e.g., a chip bin, having enhanced penetration of the chips by a white cooking liquor may not need a separate impregnation stage. In an embodiment, the target is to cook softwood thin chips to Kappa numbers of over 50, in a range of 50 to 70 and over 70 and hardwood thin chips to Kappa numbers of over 25, in a range of 25 to 50 or over 50. These high Kappa numbers are possible because the cooking conditions are mild and thin chips are easily cooked. The cooking and impregnation may be carried out using same liquor.
The alkali penetration of the white liquor into the thin wood chips may be fast, and will be faster if the liquor wood ratio is low. A high alkali content in the white liquor accelerates the penetration of the chips. The white liquor may be about 60 percent (%) to 70% total alkali. The alkali may be transferred to thin chips without a long impregnation retention time in the chip bin or digester vessel. Further, the diffusion of cooking chemicals into the chips after the initial impregnation of the chips may be less critical because of a high alkali concentration of the white liquor.
The Kappa number may high, e.g., greater than 50 for softwoods and greater than 25 for hardwoods, and the porosity of the pulp/chips discharged from the digester vessel may be maintained and a sufficient washing and cooling can be carried out in the bottom of the digester. If the alkali concentration in the white liquor is high, the alkali penetration and diffusion into the chips will proceed quickly. Due to the fast penetration, alkali may be transferred to thin chips without a long impregnation period. The chip retention period in the chip feed system and digester vessel need be relatively short. If chip impregnation is achieved quickly, e.g., in 2 to 5 minutes, the impregnation stage may be performed in the chip bin and a separated impregnation stage may not be necessary.
The cooking of the chips in the white liquor may be done at a mild temperature (e.g., at or above 130 degrees Celsius (° C.)) in the digester vessel 120 . The thin chip cooking process may employ cooking temperatures lower than the temperatures (150 to 180 degrees Celsius) of conventional cooking processes.
The conventional cooking control parameter (H-Factor) may not be a sufficient indicator of the cooking process of thin chips, and may not be best used to calculate retention time or cooking temperature for the thin chip cook process. The lower cook temperature of the thin chips may protect the pulp during the first minutes of exposure to the cooking conditions in the digester vessel. In the thin chip cooking process the cooking time is over two hours of the chips in the digester vessel 120 .
A digester vessel 120 cooking thin chips at cooking conditions yielding pulp with such high Kappa numbers should produce chips that are not too soft. The thin chips produced under these cooking conditions should withstand the forces at the bottom of the chip column in the digester vessel without becoming excessively compressed, packed or agglomerated at the bottom of the digester vessel.
Once cooked, thin chips/pulp tend to easily disintegrate at the bottom of the digester vessel and after discharge from the digester vessel, such as in the fiberline process downstream of the vessel. The easy disintegration the chips/pulp may render unnecessary the recirculation of unprocessed chips from the bottom of the digester vessel back to the top inlet of the vessel.
By avoiding the recirculation of chips, the yield from the bottom of the digester of thinner chips may result in a chip yield increase of 3 percent (%) to 15% over conventional cooking of thicker chips. For example, under conventional cooking conditions, the yield of softwood is typically 45% to 50% when using Lo-Solids® Cooking as sold by Andritz Inc. Using the thin chip cooking method, yields of pulp may be 48% to 65% which are a significant increase over conventional pulp yields.
Other benefits of the thinner chip cooking method may include less complicated equipment and fewer equipment components, as compared to conventional continuous chip digesting systems. Further, the pulp discharged from the digester vessel may be used directly as brown pulp to form brown packaging material that does not require bleaching of the pulp. In addition, the pulp discharged from the digester vessel may be sufficient to form bleachable paper and other white paper products because the pulp is in fiber form with low reject pulp.
FIG. 1 is a schematic illustration of an exemplary embodiment of a cooking system 100 for thinner chips. The cooking system 100 includes a chip bin 110 and a continuous flow, chemical digester vessel 120 . The cooking system 100 includes a white liquor input line 106 , e.g., a pipe or other conduit, that adds white liquor to the thin chips in the chip bin. Additional cooking liquor may be add as the chips are discharged from a chip conveyor 140 and are pumped 150 through chip feed line 108 to the digester vessel 120 .
The white liquor added to the chip bin and chip conveyor may be sufficient for cooking the chips in the digester vessel 120 , such that additional cooking liquor need not be added to the digester vessel. The white liquor may be mixed with or substituted by green liquor or other cooking liquids. Wash liquid and other liquor may be added to the digester vessel 120 and to chip transport lines 108 to facilitate chip flow through transport lines and chip discharge from the digester vessel.
Thin chips may have a particle size distribution in which 85% or more of the chips have a thickness of no greater than 6 mm. The chips being transported through a chip feed line 102 may be screened prior to entering a chip screw device 130 at the inlet to the chip bin 110 or as the chips leave the bin 110 and enter a chip metering and conveyor device 140 .
A chip screening device screening device 119 may be a conventional screening device except for smaller openings for screening the chips. For example, to obtain chips having an average thickness of 6 mm the screening device 119 may have 6 mm slots in a first screen and 5 mm or 4 mm holes in a second screen. Chips that pass through the first screen but not the second screen are fed to the chip bin 110 .
The chips are fed via the screw conveyor 130 to the chip bin 110 . The chip bin 110 may be a conventional chip bin, such as the Diamondback® chip bin supplied by Andritz Inc. Low pressure steam may be added via steam line 104 to chip bin 110 , such that the temperature and pressure of the chips in the chip bin may be controlled. The chip bin 110 may also operate as a pre-steaming stage to heat and soften the chips.
White liquor may be added via line 106 to the chip bin 110 to impregnate chips with cooking liquid while they are in the bin and the chip transport line 108 . The white liquor may partially flood the chip bin with liquor. The white liquor may be added at a lower elevation of the chip bin to facilitate transportation of the chips to the chip metering and conveyor screw 140 or other type of conveyor located at the bottom of the chip bin. Liquor may be added in the chip bin or in the chip transport stream to reduce the chip density of the chip slurry flowing to the top of the digester and thereby facilitate the transport and pumping of the slurry.
The chips may presteamed in the chip bin and retained in the chip bin for a pre-steam residence time of 5 min to 60 min. Thorough and complete pre-steaming of the thin chips enhances the mass transfer into the chips of the cooking liquid (and purging air from the chips), facilitates the cooking of the chips in the digester vessel and reduces the risk that the chips will plug the bottom of the digester vessel. After presteaming, the chips may be transferred to a liquid, e.g., a transport liquid. Chips may be soaked with the cooking liquor as the chip slurry is fed to and through the feeding device.
Recycled liquor and other liquids, e.g., black liquor, recovered from a black liquor filter 190 , a top separator 122 in the digester vessel 120 and other locations in the pulping process, e.g. wash filtrate, may be injected into the chips by a nozzle 141 near the discharge end of the chip conveyor 140 to facilitate transportation of the impregnated chips to one or more pumps 150 , e.g. a TurboFeed® chip feeding system, through chip transport pipe (line) 108 to an inverted top separator 122 of the digester vessel 120 .
One or more chip feeding devices 150 may pressurize the chip and liquor slurry. The chip feeding device may be one or more of a high pressure feeder (HPF), a pump(s) and a feed valve. Prior to the feeding device there may be a chip tube, chip tank or chip vessel, in which the liquor level may be controlled and which temporarily holds the chips. This system (which includes thin chips) may facilitate the immediate penetration of cooking liquor as well as chip neutralization.
The digester vessel 120 may employ a continuous process, such that chips and steam are continuously being added to the top of the digester 120 and pulp is continuously discharged from the bottom of the digester. The residence period of the chips in the digester vessel 120 is dependent on specific cooking conditions and the digester vessel.
The top separator 122 , e.g., an inverted top separator, may extract a portion of the liquor in the chips entering the separator. The extracted liquor flows through a liquor recirculation line 112 to be injected via nozzle 141 into the chip flow at the discharge of the chip conveyor 140 . The top separator 122 is optional and, if removed, the chips may be discharged directly into the top of the digester vessel 120 without the extraction of liquor.
The digester vessel 120 includes a controlled pressure steam inlet line 114 . The addition of steam via line 114 provides a means for controlling the cooking pressure and temperature in the digester vessel. Steam pressure in line 114 may be controlled in a conventional manner to achieve a desired temperature in the digester vessel 120 and avoid flashing of the steam in the vessel.
The chips in digester vessel 120 may be heated to the cooking temperature quickly after entering the top of the digester vessel. The steam (e.g., medium pressure, low pressure steam or steam from digester or evaporator equipment) added at the top of the digester vessel quickly brings the chips to a cooking temperature, e.g., 130 degrees Celsius or above, as the chips enter the vessel through the top separator. The steam added via line 114 to the top of the digester vessel may be at medium or low pressure as required to meet the temperature requirements of the cooking process in the vessel.
In an exemplary embodiment, the digester vessel 120 operates at a pressure of at least 2 bars gauge and at a temperature of at least 130° C. These are cooking conditions under which the thin chips are processed in the digester vessel. The single digester vessel cooking system shown in FIG. 1 , may be embodied as a two or more vessel cooking system configured for thin chip cooking and to operate under similar cooking conditions as are disclosed herein.
The flow of the thin chips, e.g. the chip column, through the digester vessel 120 may be a unidirectional downward flow and a uniform chip flow across the entire cross-section of the chip column. The digester vessel may not have cooking liquor recycle loops, cooking liquor countercurrent flow or extraction cooking screens at multiple elevations in the vessel. The cooking zone 121 of the vessel may be cylindrical with smooth and uniform cylindrical walls, which may expansion rings 123 where the diameter of the vessel expands. The interior walls of the cooking zone 121 may be free of screens, nozzles and other devices to add or extract fluid to the cooking zone.
The digester vessel 120 may further include one or more inlets for wash liquid, which may be water. The wash liquid mixes passes through the chips/pulp in a wash zone 125 in a lower section of the digester vessel.
Wash liquid may be added to the digester vessel via wash lines 148 , 146 and 144 to the digester vessel 120 . Wash liquid enters the system 100 via line 136 , where it is optionally pressurized. A pump 180 may move the wash liquid towards the wash zone and may pressurize the wash liquid. Optionally, the wash liquid may be thermally adjusted (e.g., heated or cooled) via a heat exchanger 170 . In certain embodiments, the heat exchanger 170 may use warm water via 138 as a cooling medium, and in such a case, hot water exits the heat exchanger via line 142 . The heat exchanger 170 may be known as a cold blow circulation unit.
After the optional pressure and temperature adjustment, wash liquid may be split into at least three lines 144 , 146 and 148 . Wash liquid flowing through line 144 enters the bottom of the digester 120 and inhibits clogging of the pulp at discharge outlet 160 , and adds liquid to promote flow of the chips through discharge line 134 . Wash line 146 may also inhibit chip clogging by injecting wash liquid upward into the bottom of the vessel imparting to agitate the pulp in the bottom of the vessel. Wash liquid injected to the bottom of the vessel via line 148 similarly may inhibit clogging by imparting a horizontal force on the pulp and thereby agitate the pulp. The wash liquid may also assist in diluting or removing the spent liquor that may or may not be entrained in the cooked chips.
The digester vessel 120 includes a wash screen 124 adjacent a wash zone 125 below the cooking zone. The wash screen 124 separates at least a portion of the liquid, which may include spent liquor, wash liquid, water and other filtrate liquids. The filtrate liquids pass through the wash screen and into an annular filtrate chamber 126 on a side of the screens opposite to the flow of chips down through the digester vessel.
The separated liquid, commonly referred to as black liquor or filtrate, is drawn from the chamber 126 into wash filtrate extraction line 116 and flows to a black liquor filter 190 . The filtered strong liquor exits the black liquor filter 190 via line 118 , and a filtered weak black liquor exits the black liquor filter 190 via liquor recirculation line 132 . The filtered weak liquor may be circulated, in whole or in part, back to the chip screw conveyor 140 . The liquor exiting the black liquor filter 190 via line 118 may pass through a cooler which extracts heat energy and flow to a further process stage, such as a flash tank or recovery boiler.
The pulp, e.g., cooked thin chips, is discharged from the digester vessel 120 via a pulp transport line 134 . Little or no additional refining or pulping may be needed after the pulp is discharged from the digester vessel. The discharged pulp may be used as brown stock to form corrugated paper and other materials. Alternatively, the brown stock may be washed using conventional pulp washing techniques.
After being discharged from the digester vessel 120 , the pulp may be optionally washed, such as before proceeding to a bleaching or delignification stage. The separate wash step may be a conventional brown stock wash stage involving washing with the DD-washers offered by Andritz Inc. or other conventional washing equipment to remove cooking liquor remaining with the material after the washing stage within the digester, diffusers or vacuum filters. Alternatively, the further washing step may be unnecessary if the pulp is sufficiently washed in the wash zone 125 of the digester vessel.
The washed pulp may be whitened in an oxygen delignification stage (O2-stage) or other bleaching process. For example, the pulp may be treated in an O2-stage to inject oxygen to the pulp stock to continue the delignification of the pulp. If the oxygen delignification stage is strong, the conditions in the digester vessel 120 may be adjusted to produce pulp with a reduced Kappa number of 15 to 30 for soft woods and 10 to 20 for hard woods. Reducing the Kappa number allows the pulp to be bleached in conventional totally chlorine free (TCF) and elemental chlorine free (ECF) bleaching stages.
Chives and other small wood pieces, e.g., splinters and rejection pieces, may be processed in the delignification stage as they need not be circulated back to the digester. Further, chives may be sufficiently small that the O2-stage alone can remove the lignin. Accordingly, chives may flow directly to the O2-stage without passing through the digester vessel.
The thin chip cooking process described herein produces a pulp requiring less washing, oxygen delignification, screening and bleaching than pulp produced by traditional high Kappa cooking methods. The cooking system 100 need not require long chip impregnation periods.
The methods and systems described in this application may not require a high liquor to wood ratio during the impregnation. For instance, it may be preferable that liquor impregnation times of less than 2 hours, and liquor to wood ratios of less than 7 may be used for cooking the thin chips.
A majority or all of the white liquor used for pulping the chips may be introduced in the beginning (e.g., in the chip bin 110 or feed system circulation) of the cooking system 100 . This early introduction of white liquor may result in a high chip alkalinity and concomitant enhanced diffusion rate of the liquor into the chips. In certain embodiments, the system may have a short impregnation periods for the chips and the temperature of the chips can be raised to cooking temperature, e.g., 130 degree Celsius to 160 degree Celsius, directly in the top of the digester in a one vessel system (e.g., impregnation in the lower part of the chip bin and impregnation vessel 110 or in the feeding circulation or in the top of the digester may be sufficient). Although illustrated as one vessel, the chip bin and impregnation vessel 110 may be separate vessels.
The withdrawal of liquor from the chips may occur only at the end of the cooking process. In certain embodiments of thin chip cooking, the cooking system 100 may be simplified as compared to conventional cooking with thicker chips. Thin chip cooking may be suitable for retrofits of previously existing mills and newly built mills. For example, a high Kappa pulp is possible to produce without an in-line refiner.
Because the amount of black liquor produced and discharged to line 118 from cooking thin chips in the manner discussed above is less than the amount of black liquor that would be expected to be produced in a conventional thick chip cooking process, the recovery boiler needed for the black liquor from line 118 may be smaller that the recovery boiler needed for larger chips. In particular, the high yield of pulp which results in the above described thin chip chemical pulping process yields fewer by-products to burn in the recovery boiler. Similarly, the white liquor plant needed to produce white liquor for the thin chip chemical pulping process may be may be smaller or minimized, as compared to the white liquor plant needed for a conventional thick chip chemical pulping process because the thin chip process requires less white liquor, e.g., the white liquor charge, for cooking than does conventional thick chip cooking.
Associated with the addition of white liquor to the wood chips, there is a penetration stage in which the liquor penetrates the chips. After the penetration stage, a mass transfer of the cooking chemicals into the chips occurs by diffusion of the chemicals into the chips. Thinner wood chips may enhance the mass transfer. Because of the enhanced mass transfer, the delignification during cooking may be improved and the temperature may be raised at the top of the digester directly to the cooking temperature. For instance, if the thickness of the wood chip is half of the thickness of a standard wood chip, the time needed to achieve liquor penetration of the thin chips may be a quarter of the time needed for liquor to penetrate a thick wood chip.
The thin chip cooking system 100 may provide a cost-effective chip and pulp processing system with high Kappa cooking. The cost may be held low because it may not be necessary to refine the chips or pulp generated by the disclosed thin chip processing system. The thin chip cooking system may also be efficient in that they system may produce more pulp using the same amount of wood as compared to a conventional thick chip cooking system and, thus, provide a significant yield increase as compared to conventional thick chip digesting processes.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A method to cook thin chips in a continuous digester vessel including: introducing thin chips having a thickness of no more than 6 mm, into a chip bin; adding white (cooking) liquor to the chip bin or to a chip transport passage extending from the chip bin to an upper inlet of the continuous digester vessel; injecting medium pressure steam or another heated fluid to an upper region of the digester vessel to elevate a cooking temperature of the chips in the vessel to at least 130 degrees Celsius; cooking the chips in the vessel as the chips flow downward through the vessel without substantial extraction or introduction of liquor in the cooking section of the vessel; injecting wash liquid to a lower region of the vessel; extracting at least wash liquid through a wash liquid extraction screen in the lower region of the vessel and above the injection of the wash liquid, and discharging the cooked thin chips from the lower region of the vessel. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional App. No. 61/293,354 filed Jan. 8, 2010, which application is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE DISCLOSURE
[0003] In recent years, various pneumatic grain conveying systems have been employed for conveying grain to and from a grain storage bin or the like. These prior pneumatic grain conveying systems typically employed a positive displacement blower for forcing air into a closed duct or pipe system. Grain to be conveyed was introduced into the piping downstream of the blower by means of a so-called airlock grain inlet or other grain infeed device, which fed the grain into the pipe system in such a manner that the grain was entrained by the air flowing through the pipe system and in such a manner that the pressurized air was not lost thus maintaining the conveying capacity of the pneumatic conveying system. Downstream from the grain inlet the piping system may be directed upwardly, for example, along the sidewall of a grain bin, and along the sloped, conical grain bin roof to a center grain inlet opening in the roof, where a so-called deadhead deflector or a cyclone diffuser was positioned so as to allow the pressurized air to be vented to the atmosphere and to direct the grain into the grain inlet in the grain bin roof. Such pneumatic grain conveying systems have the advantage of moving the grain within a cushion of air that minimizes damage to the grain, as compared to mechanical grain auger conveyors or other types of mechanical grain conveying systems.
[0004] However, such pneumatic grain conveying systems, especially such pneumatic grain conveying systems having high capacity (e.g., 2,500 bushels/hour), require a powerful electric motor (e.g., up to 75 horsepower) for powering the positive displacement blower. Such motors are expensive. It is thus desirable to utilize the same motor and the same airlock grain infeed unit to convey grain to a plurality of grain storage bins. Heretofore, this has been accomplished by providing separate piping systems from the air lock to the various grain storage bins with a complex manifold/distributor, such as shown in FIG. 2 of the instant drawings and as will be hereinafter described, so as to permit the pressurized air duct from the grain infeed airlock to be selectively connected in an air tight fashion to a desired or selected piping system for a selected one of the plurality of grain storage bins. Not only did this prior manner of connecting the pressurized air conveying system to the piping system for a selected grain storage bin require the complex manifold/distributor, but it also required separate piping runs from the grain inlet airlock to each of the grain storage bins with each of these piping runs having a horizontal run along the ground and a vertical run along the vertical sidewall and conical roof of each bin. In turn, this added to the expense and complexity of such prior pneumatic conveying systems. These multiple runs of piping along the ground often interfered with vehicles which require close access to the grain bins. Still further, it has been found that such manifold/distributor systems are sometimes difficult to operate and they often require that the blower and airlock infeed be shut down while making a change from conveying to one bin and then to another bin.
SUMMARY OF THE DISCLOSURE
[0005] A pneumatic conveying system is disclosed for conveying a dry flowable or granular product, such as grain, from a grain inlet device to a selected one of a plurality of grain bins or other storage vessels. The system includes a blower for forcing air under pressure into a conveyor piping system. A grain inlet device is located downstream from the blower. The piping system has a portion leading from the grain inlet to an inlet in a first one of the vessels. A discharge/bypass valve is connected to a portion of the piping system leading from the grain inlet so as to receive the granular product being conveyed therethrough with the valve having a discharge outlet for discharging the granular product into the vessel and a by-pass outlet for by-passing the first vessel and delivering the granular product to a second vessel. The valve is installed on the vessel such that the discharge outlet is in communication with the interior of the vessel. The valve further has an inlet coupling operatively connected to the piping system and an outlet coupling operatively connected to another portion of the piping system downstream of the valve leading to another of the vessels. The valve has a sleeve movable between a discharge position in which the inlet coupling is disconnected from the outlet coupling such that the granular product is discharged from the piping system into the valve and then is discharged into the vessel and a by-pass position in which the inlet and outlet couplings are operatively connected so that the granular product is conveyed through the valve and into the piping system downstream from the valve. The by-pass outlet comprises the outlet coupling.
[0006] In one embodiment, the housing for the valve can be provided with a hopper. The hopper opens into the valve housing below the valve to be in communication with the interior of the vessel. The hopper can receive granular product from an auger, which need not be permanently affixed to the hopper. In this manner, the granular product can be delivered to the vessel via an auger without having to remove the discharge/by-pass valve.
[0007] A method of selectively conveying this granular product to a selected one of the vessels is also disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a diagrammatic side elevational view of a typical pneumatic grain conveying system having a positive displacement blower forcing pressurized air into a piping system with an airlock grain infeed downstream from the blower, with a piping system conveying the grain upwardly along the vertical sidewall and along the conical roof of a first grain storage bin (only half of which is illustrated) or other receiving vessel to a so-called grain discharge/by-pass valve of the present disclosure mounted on a center grain inlet in the roof of the first bin, with a reach of piping extending from the outlet of the discharge/by-pass valve to a deadhead deflector mounted on a center grain inlet of a second grain storage bin (again, only one half of the bin is illustrated) or other vessel so that with the discharge/by-pass valve on the first bin in its discharge position grain may be discharged into the first grain bin and so that with the discharge/by-pass valve in its by-pass position grain may by-pass the first bin to be discharged into the second bin;
[0009] FIG. 2 is a perspective view of a prior art manifold/distributor assembly for connecting the pressurized air duct downstream from the airlock grain infeed to a selected one of a plurality of air conveying ducts or piping systems for conveying the grain to a selected one of a plurality of grain storage bins;
[0010] FIG. 3 is a perspective side elevational view of a first embodiment of a discharge/bypass valve of the present disclosure with the valve in a discharge position to discharge grain into the bin on which the valve is mounted;
[0011] FIG. 4 is a perspective view of a portion of the valve shown in FIG. 3 with the exterior housing of the valve removed to better illustrate the components within the housing with these components arranged in a by-pass position so that grain conveyed to the valve will not be discharged into the grain bin on which it is installed but rather will by-pass the grain through the valve into a piping run that will convey the grain to another grain storage bin, with the components of the valve including a rack and pinion linear drive for axially moving a sleeve between a by-pass position (as shown in FIG. 4 ) in which the grain is pneumatically conveyed through the valve and a discharge position, as shown in FIGS. 3 , 5 and 6 , in which grain is discharged into the bin below the valve;
[0012] FIG. 5 is another view of the valve as shown in FIG. 4 with its components arranged in their discharge position with a flapper diverter member disposed at the outlet end of the above-noted sleeve so as to direct grain conveyed through the sleeve downwardly into the bin on which the valve is mounted;
[0013] FIG. 6 is a view similar to FIG. 5 in which the flapper diverter member is raised clear of the end of the sleeve so as to permit the sleeve to be moved axially to be coupled to the piping downstream of the valve when the sleeve is in its by-pass position;
[0014] FIG. 7 is a perspective view of a second embodiment of the valve;
[0015] FIG. 8 is a perspective view of the second embodiment of the valve with portions of the outer housing removed to illustrate internal components, where the above-described flapper diverter member is replaced by curved grain diverter member selectably movable between a discharge position, as shown in FIGS. 8 and 9 , in which, with the sleeve in its above-described by-pass position, grain may flow through the valve to a grain bin downstream from the first bin;
[0016] FIG. 9 is a view similar to FIG. 8 on a somewhat enlarged scale illustrating the axially movable sleeve in its retracted discharge position with the curved grain diverter member in its diverting position;
[0017] FIG. 10 is a view similar to FIG. 9 , on an enlarged scale and with a side wall of the curved grain diverter member removed to better illustrate the curved plate of the diverter member;
[0018] FIG. 11 is a view similar to FIG. 9 with the curved diverter member moved clear of the sleeve and with the sleeve axially extended so as to form a fluid tight (or air-tight) connection between the inlet and outlet couplings so that grain may by-pass the discharge outlet of the bin on which the valve is installed to be delivered to another bin;
[0019] FIG. 12 is a perspective view of a third embodiment of the valve provided with a hopper to enable a bin on which the valve is placed to alternatively be filled by means of a traditional transport auger;
[0020] FIG. 13 is a perspective view of the valve of FIG. 12 , but taken from an opposite side of FIG. 12 ;
[0021] FIG. 14 is a perspective view of the valve of FIG. 12 with portions of the housing removed to show an internal wall of the valve; and
[0022] FIGS. 15 and 16 are cross-sectional views taken along lines 15 - 15 and 16 - 16 , respectively of FIG. 12 , but wherein the curved diverter plate of the valve of FIG. 12 is replaced with an inclined diverter plate.
[0023] Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] The following detailed description illustrates the claimed invention by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the claimed invention, and describes several embodiments, adaptations, variations, alternatives and uses of the claimed invention, including what we presently believe is the best mode of carrying out the claimed invention. Additionally, it is to be understood that the claimed invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The claimed invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting
[0025] Referring now to the drawings and particularly to FIG. 1 , a pneumatic grain conveying system, as indicated in its entirety at 1 , is shown to be installed on a plurality of grain storage bins or vessels 3 and 5 . Two grain bins 3 and 5 are shown, but those of ordinary skill in the art will understand that additional grain bins can be connected to one another in the manner that bin 3 is connected to bin 5 . As is typical, each of the grain bins has a vertical sidewall 7 , a sloped conical roof 9 , and a grain inlet 11 at the peak of the conical roof.
[0026] The pneumatic grain conveying system 1 includes a motor and blower assembly 13 (preferably a positive displacement blower), which forces pressurized air into a conveyor piping system 15 . The blower and motor are controlled by a control panel 17 . Downstream of the blower, a so-called airlock/grain infeed unit 19 is provided for introducing grain (or other granular, powdered or pulverulent flowable material capable of being pneumatically conveyed) to be introduced into the pressurized air stream moving through piping system 15 . Piping system 15 includes a horizontal run 21 leading to a horizontal-to-vertical elbow 23 , which in turn is connected to a vertical run 25 extending upwardly along the sidewall 7 of the first grain bin. The piping system further includes a sloped run 25 along the conical roof 9 of the first grain bin toward the inlet 11 of the first grain bin.
[0027] A discharge/by-pass valve 27 of the present disclosure is installed in register with the grain inlet 11 of the first grain bin. The valve 27 has an inlet 29 coupled to the downstream end of the sloping run 25 and an outlet 31 coupled to pneumatic conveyor tube 33 extending from the valve 27 to a deadhead deflector 35 installed on the grain inlet 11 of the second grain bin 5 . This deadhead deflector 35 allows the pressurized air to escape to the atmosphere thus disrupting the flowing airstream in the conveyor piping run 33 and deflects the grain conveyed through piping run to be discharged into the second grain bin. While not illustrated, it will be understood that in place of the deadhead deflector 35 installed on the grain inlet 11 of the second grain bin, another valve 27 of the present disclosure may be installed on the grain inlet of the second bin and another run of piping (not shown) may be connected to the outlet end 31 of this other valve 27 , where this other run of piping leads to the grain inlet 11 of another (i.e., a third) grain bin (not shown) so that grain conveyed to the second bin via the piping run 33 may be selectively discharged into the second bin or may be selective by-passed to the next grain bin. In this manner, the pneumatic conveying system 1 utilizing valves 27 may selectively convey grain to any one of a plurality of grain bins merely by operating the valves 27 installed on the grain inlets 11 of the grain bins upstream of the selected bin to be in their by-pass positions and by operating the valve 27 (or a deadhead valve 35 ) installed on the selected bin in its discharge position. As will become apparent, the discharge/by-pass valves 27 can be operated to selectively alter the bin or vessel in which the grain is to be deposited without the need to shut down the pneumatic conveying system.
[0028] In FIG. 2 , a prior art distributor manifold/selector valve assembly is indicated in its entirety by reference character 201 . The distributor manifold/selector valve 201 includes a frame 203 having a base plate 205 , a head plate 207 , and elongate spacer members 209 extending between the base plate and the head plate. An inlet piping section 211 is adapted to be connected to the pneumatic piping system 15 downstream from airlock grain infeed unit 19 . Preferably, the distributor/manifold assembly 201 is installed adjacent the first grain bin. The head plate 207 has a plurality of manifold ports 213 (six such ports are shown) such that a selected piping run, as indicated at 215 a , 215 b , 215 c , may be operatively connected to the inlet piping section 211 . Each of these last-noted piping runs leads to a respective grain bin so that grain may be selectively conveyed to that grain bin. A selector pipe 217 coupled to the inlet pipe 211 may be selectively coupled to a selected one of the manifold ports 213 , and thus to a selected one of the piping runs 215 a , 215 b or 215 c so as to convey grain to the grain bin corresponding to that piping run.
[0029] Referring now to the valve 27 installed on the first grain bin (as shown in FIG. 1 ), a first embodiment of the valve is illustrated in FIGS. 3-6 . As shown best in FIG. 3 , the valve 27 includes an exterior housing 37 having a top housing panel 39 , side panels 41 , an outlet end plate 43 , an inlet end plate 45 , a bottom plate (not shown in FIGS. 3-6 ), and a bottom hopper discharge chute 47 defining a discharge outlet through which grain is discharged into the grain inlet 11 of the bin supporting the valve 27 . The inlet end plate 45 has an inlet coupling tube 51 adapted to be coupled to the sloped piping reach 25 , and the outlet end plate 43 has an outlet coupling tube 49 adapted to be coupled to piping run 33 . As will become apparent, the outlet coupling tube defines a by-pass outlet of the valve 27 . The inlet coupling tube 51 is rigidly and sealably secured to its inlet plate 45 and the outlet coupling 49 is rigidly and sealably secured to its outlet plate 43 with the inlet and outlet coupling tubes being substantially coaxial with respect to one another and with a space between their inner ends, as shown in FIGS. 5 and 6 . As indicated at 52 a and 52 b , internal support plates support the inner ends of tubes 49 and 51 , respectively, within housing 37 .
[0030] In accordance with this disclosure, a valve member, shown as a sleeve 53 in the drawings, is axially movable relative to the inlet and outlet coupling tubes 49 and 51 by means of an actuator (a linear actuator as will be hereinafter described), as generally indicated at 55 , as shown in FIGS. 4-6 . The sleeve valve member 53 is movable in an axial direction with respect to the inlet and outlet coupling tubes between a first or by-pass position (more specifically, an extended coupling position as shown in FIG. 4 ) in which grain conveyed to valve 27 will be conveyed through or by-passed through the valve to the next grain storage bin downstream from the bin on which the valve 27 is installed, and a second or discharge position (more specifically, a retracted position as shown in FIGS. 3 , 5 and 6 ). With the sleeve 53 axially uncoupled from inlet coupling tube 51 , the pressurized air within the piping system 15 will be discharged into housing 37 , which is vented to the atmosphere and so that the grain entrained in the air stream flowing through the inlet coupling tube 51 will fall by gravity downwardly into the discharge chute 47 . The linear actuator 55 is also operable so as to axially move the sleeve 53 from its retracted discharge position (as shown in FIGS. 3 , 5 and 6 ) to its extended by-pass position (as shown in FIG. 4 ) in which the sleeve is sealably coupled to the inlet tube 51 . With the sleeve in its by-pass position, the pressurized air stream and the grain entrained therein will be conveyed through the valve 27 and will be conveyed via piping run 33 to the next grain storage bin. Although the sleeve 53 is shown to be moved toward and away from the inlet coupling tube 51 by the actuator 55 , the valve sleeve could alternatively be positioned over the inlet coupling tube, so that the actuator 55 moves the sleeve 53 toward and away from the outlet coupling tube 49 .
[0031] As shown in FIGS. 4-6 , the linear actuator, as generally indicated at 55 , comprises a rack and pinion mechanism having a rack 57 attached to the bottom of sleeve 53 and a pinion 59 journalled on a shaft 61 supported by bearings 63 carried by the housing side walls 41 . The shaft 61 may be selectively rotated by means of a sheave 64 , wheel, or the like attached to one end of the shaft 61 . The sheave may be rotated by any suitable means, such as an electric motor (not shown), or by means of a chain or belt and pulley arrangement (also not shown) that may be manually operated from ground level. Alternatively, the linear actuator may be a fluid cylinder (not shown), such as an air or pneumatic cylinder, that may be remotely actuated so as to move the sleeve 53 between its extended by-pass position and its retracted discharge position. Further, those skilled in the art will recognize that other well known linear actuators, such as a screw drive or the like, may be used. Such linear actuators thus constitute a means for selectively moving the sleeve 53 in an axial direction between its extended by-pass position and its retracted discharge position so that grain may be selectively discharged into the bin below the valve 27 or by-passed to the next bin downstream from the bin on which the valve 27 is installed.
[0032] A block 60 is mounted to the sleeve 53 and a post 62 extends forwardly from the block. The post 62 slides through an alignment hole in the support plate 52 b , to ensure axial alignment of the sleeve 53 with the inlet coupling tube 51 as the sleeve 53 is moved to its extended position in which the sleeve 53 is connected to the inlet coupling tube 51 . The exit end of the inlet coupling tube 51 is tapered to facilitate guiding of the sleeve 53 over the inlet coupling tube when the sleeve is moved to its extended position. The ends of the sleeve 53 can also be tapered.
[0033] The sleeve 53 has an inner diameter greater than the outer diameter of the inlet coupling tube 51 and the outlet coupling tube 49 . The inlet and outlet coupling tubes 51 and 49 are of generally the same inner and outer diameter. The sleeve 53 can thus slide over both the inlet and outlet coupling tubes. The sleeve 53 is provided with internal O-rings 54 at both ends of the sleeve. The O-rings form an air-tight seal between the sleeve 53 and both the inlet and outlet coupling tubes 51 and 49 when the sleeve 53 is in the extended position. The substantially eliminates air (and thus air pressure) loss when the sleeve is in the extended position, to facilitate the transport of the product to the second bin. Although the O-rings are described as being internal O-rings on the sleeve 53 , the O-rings could be external O-rings on the inlet coupling tube and the outlet coupling tube. Any other desired means to form an air-tight seal between the sleeve 53 and the inlet and outlet coupling tubes may also be used. As can be appreciated, the valve 27 provides for an air-tight or pneumatically sealed connection when the sleeve 53 is in its extended position, and an unsealed, atmospheric connection when the sleeve 53 is retracted.
[0034] As further shown in FIGS. 3-6 , a diverter or deflector member 65 , illustratively shown as a flapper or plate, is mounted on a shaft 67 above the sleeve 53 for movement between a raised, retracted position (as shown in FIGS. 4 and 6 ) in which the diverter member is clear of the sleeve and a lowered, diverting position (as shown in FIGS. 3 and 5 ) in which the diverter member 65 is positioned in a discharge space between the retracted sleeve 53 and the outlet end of inlet coupling tube 51 so that grain conveyed through the inlet coupling tube 51 will impinge against the diverter member and be directed downwardly into discharge chute 47 . The diverter member 65 is pivoted from its lowered position to its raised position by the axial movement of the sleeve 53 . That is, as the sleeve 53 is moved axial to its extended by-pass position, the sleeve 53 will engage the diverter member 65 and pivot the diverter member to the raised position. The diverter member 65 is gravity biased toward its lowered, diverting position by means of its own weight, but it will be apparent to one skilled in the art that the movement of the diverter member could be mechanically coupled to the linear actuator to provide a positive engagement and retraction of the diverter. A counterweight 69 can be affixed to one end of the shaft 67 on the exterior of housing 37 . This counterweight also serves as a flag or visual indicator visible from the ground to indicate to an operator whether the sleeve 53 is in its discharge or by-pass position.
[0035] Referring now to FIGS. 7-10 , a second embodiment of the discharge/bypass valve of the present disclosure is indicated in its entirety by reference character 27 ′. The valve 27 ′ is similar to valve 27 , as described above, except the flapper diverter member 65 has been replaced by a curved diverter member 71 . The other components of the alternate discharge/bypass valve 27 ′ are similar to the corresponding components of the valve 27 and thus will not be again described. More specifically, the curved diverter member 71 has a curved deflector plate 73 within a diverter housing 75 , as perhaps best shown in FIGS. 10 and 11 . The curved plate 73 could be replaced with an sloped or inclined plate 73 ′ as shown in FIG. 15 or a flat plate. With sleeve 53 in its retracted position clear of the inlet coupling 51 , the diverter housing 75 , which is mounted on shaft 67 for selective rotatary movement about the shaft, is movable between a lowered discharge position (as shown in 8 and 9 ) and a raised position (as shown in FIG. 11 ). In the lowered position, the curved plate 73 is positioned downstream from the inlet coupling tube 51 so that grain discharged from the inlet coupling tube impinges against the curved plate 73 and is directed downwardly into the discharge chute 47 . The diverter housing 75 is also rotatably movable from its above-described lowered discharge position to a raised retracted position (as shown in FIG. 11 ) in which the sleeve 53 may be moved from its retracted discharge position to its extended by-pass position in which it is axially, sealably coupled to inlet coupling tube 51 so that grain may be conveyed through the valve 27 ′ and into piping run 33 to the next grain storage bin. As with the diverter member 65 , the diverter member 71 is pivoted from its lowered position to its raised position by the sleeve 53 . It will be understood that the diverter member 71 may be gravity biased toward its lowered discharge position in the same manner as flapper diverter member 65 , as above described, and likewise may be mechanically coupled to the linear actuator as previously described. Also, it will be understood that when sleeve 53 is axially moved from its retracted discharge position to its by-pass position in which it is in axial coupling engagement with inlet tube 51 , the housing 75 is moved to its retracted position clear of the end of the sleeve. The valve 27 ″ also includes the flag or indicator 69 which is rotationally fixed to the shaft 67 to indicate the position of the diverter member 71 .
[0036] Referring now to FIGS. 12-14 , a third embodiment of the discharge/bypass valve of the present disclosure is indicated in its entirety by reference character 27 ″. The valve 27 ″ is substantially the same as the valve 27 ′. The difference between the valves 27 ″ and 27 ′ lies in the housing of the two valves. The housing 37 ″ of the valve 27 ″ is provided with an intermediate section 81 between the discharge chute 47 ″ and the couplings 49 , 51 and the sleeve 53 . This intermediate section 81 is defined by front and back walls 83 a,b and end walls 85 . At least one of the front and back walls, and preferably both of the front and back walls, are provided with an aperture 87 ( FIG. 14 ). With reference to FIGS. 12 and 13 , the aperture of the front wall 83 a is closed by a plate 89 , and the aperture of the back wall 83 b is covered with a side hopper 91 . The hopper 91 opens into the housing 37 ″ below the elements of the valve (i.e., below the inlet and outlet couplings 51 , 49 and the sleeve 53 ) The opening to the hopper 91 is closed by a cover plate 93 . The cover plate 93 can be removed to open the hopper 91 . With the hopper opened, the bin on which the valve 27 ″ is mounted can be filled by means of a traditional auger. In this instance, the outlet of the auger would be just above, or received within, the opening to the hopper 91 . The auger need not be permanently affixed to the hopper 91 . The cover plate 93 is shown to be secured to the hopper by means of bolts, which would need to be removed to open the hopper for use. The hopper cover 93 can be hinged to the frame of the hopper, such that the cover 93 can be opened and closed either from ground level. The provision of the aperture 87 on both the front and back walls 83 a,b allows for the hopper to be mounted to either the front or the back wall. It also allows for the hopper to be moved from the front to the back wall, should that be desired. Additionally, if desired, a hopper 91 could be mounted to both the front and back walls.
[0037] With reference to FIG. 14 , the intermediate section 81 is provided with a vertical internal plate 95 . The internal plate 95 is positioned to be generally flush with the inlet of the outlet coupling (and the end of the sleeve 53 when in the retracted position). In this way, the plate 95 will keep grain away from the linear actuator (i.e., the rack and pinion).
[0038] With reference to FIGS. 12 and 14 , the sheave 64 is mounted to the shaft 61 ″ by means of a bolt 97 which passes through a passage in the shaft 61 ″. The opposite end of the shaft 61 ″ includes a corresponding passage. This allows for the sheave 64 to be positioned on either side of the valve housing 37 ″, or to be moved from one side to the other. Similarly, the counterweight 69 , which serves as an indicator flag, can be mounted on either side of the housing, or moved from one side of the housing to the other.
[0039] The diverter members 65 and 71 are described to be moved from their lowered positions to their raised positions by the sleeve 53 as the sleeve moves to its by-pass position. However, the diverter members could be connected, for example by way of linkages, to the linear actuator, such that the diverter member is directly moved by the linear actuator.
[0040] It will be recognized that regardless of the embodiment of the valve 27 , 27 ′, or 27 ″ that is utilized, the valve may be operated by its linear actuator 55 from the ground level without the necessity of shutting down the blower 13 . This aids in switching the discharge of grain from one bin to another.
[0041] While the valves 27 and 27 ′ of the present disclosure have been described in the environment of conveying grain to grain storage bins, those of ordinary skill in the art will appreciate that the air conveying system 1 may be used to convey other particulate or granular, fluent materials, such as powered materials or plastic pellets or the like that are capable of being pneumatically conveyed. Additionally, it will be appreciated that the grain storage bins may be any desired vessel for receiving the particulate or powdered material.
[0042] Still further, those of ordinary skill in the art will recognize that the slidable sleeve 53 type diverter valve may be replaced with other types of diverter valves. For example, a rotary diverter valve, such as shown in U.S. Pat. No. 5,070,910 may be used to divert the flow of grain within valve 27 between a discharge position and a by-pass position. Further, a flapper-type diverter valve, such as shown in FIGS. 7-8B of U.S. Pat. No. 6,964,544 may also be used to divert the flow of grain within valve 27 between a discharge position and a by-pass position. U.S. Pat. Nos. 5,070,910 and 6,964,544 are herein incorporated by reference in their entirety. But neither of the above referenced valves provides a pneumatically sealed connection in only one selectable position and an unsealed, atmospheric connection in another selectable position. For the valves of the two referenced patents to work according to the valves 27 , 27 ′ or 27 ″, the valves would have to be modified such that in a first position, the path between the inlet and a first outlet is sealed (i.e., air tight), and such that in a second position, the valve inlet is open to the atmosphere.
[0043] As various changes could be made in the above constructions without departing from the broad scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | A pneumatic conveying system is disclosed for conveying a granular product, such as grain, from a grain inlet device to a selected one of a plurality of grain bins or other storage vessels. The system includes a blower for forcing air under pressure into a conveyor piping system. A grain inlet device is located downstream from the blower. The piping system has a portion leading from the grain inlet to an inlet in a first one of the vessels. A discharge/bypass valve is connected to a portion of the piping system leading from the grain inlet so as to receive the granular product being conveyed therethrough with the valve having a discharge outlet for discharging the granular product into the vessel. The valve is installed on the vessel such that the discharge outlet is in communication with the interior of the vessel. The valve further has an inlet coupling operatively connected to the piping system and an outlet coupling operatively connected to another portion of the piping system downstream of the valve leading to another of the vessels. The valve has a sleeve movable between a discharge position in which the inlet coupling is disconnected from the outlet coupling such that the granular product is discharged from the piping system into the valve and then is discharged into the vessel and a by-pass position in which the inlet and outlet couplings are operatively connected so that the granular product is conveyed through the valve and into the piping system downstream from the valve.
A method of pneumatically conveying such a granular material to any one of a plurality of bins or other storage vessels is also disclosed. | 8 |
[0001] This application claims foreign priority to Canadian Patent Application No. 2,764,364, filed on Jan. 16, 2012.
FIELD
[0002] The described embodiments relate to systems and methods for optimizing resources for emulation.
BACKGROUND
[0003] An emulation system operates to imitate a computer product in an emulation session. The imitated computer product can then be provided to a host device, The computer product can be a computer system, an operating environment, a software application, and/or one or more hardware and software components. The emulation system facilitates the emulation session by translating and processing instructions received from the host device into a format compatible with the emulated computer product.
[0004] The operation of existing emulation systems is limited. For example, certain operating systems require specific resources to be available in order to boot up. Emulation systems without access to these specific resources would not be able to emulate these operating systems. Android™-based devices, for example, require a camera component to boot up.
[0005] Emulation systems can, therefore, benefit from improved access to resources available at the host device.
SUMMARY
[0006] In accordance with an embodiment of the invention, there is provided a method of providing an emulation session to emulate a computer product for a host device, the host device comprising a host processor and a plurality of host resources. The method comprises the steps of: a) providing a communication link between the host device and an emulation bridge module provided on an emulation server separate from the host device, the emulation server comprising a server storage module and a server processor: b) providing a host resource library file including a list of the plurality of resources available on the host device to the emulation bridge module; c) operating the emulation bridge module to determine a plurality of emulation session resources required to provide the emulation session; d) selecting at least one of the host device and the emulation server for providing each required emulation session resource in the plurality of emulation session resources required to provide the emulation session, the step of selecting including: in response to determining a required emulation session resource corresponds to a resource listed in the host resource library file, selecting the host device for providing the required emulation session resource: and in response to determining a required emulation session resource does not correspond to a resource listed in the host resource library file, selecting the emulation server for providing the required emulation session resource; and e) providing the emulation session using the plurality of required emulation session resources provided by at least one of the host device and the emulation server.
[0007] In accordance with another embodiment of the invention, there is provided a system for providing an emulation session to emulate a computer product for a host device, the host device comprising a host processor and a plurality of host resources. The system comprises: a host bridge module for installing on the host device, the host bridge module being configured to operate the host processor when installed on the host device, to provide a host resource library file including a list of the plurality of resources available on the host device; and at least one emulation server comprising m emulation bridge module, a server storage module and a server processor; the at least one emulation server being separate from the host device and being configured to: determine a plurality of emulation session resources required to provide the emulation session; receive the host resource library file from the host bridge module via a communication link between the host device and the at least one emulation server; select at least one of the host device and the at least one emulation server for providing each required emulation session resource in the plurality of emulation session resources required to provide the emulation session; in response to determining a required emulation session resource corresponds to a resource listed in the host resource library file, select the host device for providing the required emulation session resource: in response to determining a required emulation session resource does not correspond to a resource listed in the host resource library file, select the emulation server for providing the required emulation session resource; and provide the emulation session using the plurality of required emulation session resources provided by at least one of the host device and the at least one emulation server.
[0008] In accordance with another embodiment of the invention, there is provided a method for providing an emulation session to emulate a computer product using at least one host resource of a plurality of host resources on a host device, the host device comprising a host processor. The method comprises; a) providing a host resource library file including a list of the plurality of resources available on the host device to an emulation server separate from the host device, the emulation server providing the emulation session; b) receiving, from the emulation server, a selected host resource list, the selected host resource list corresponding to a list of resources selected from the host resource library file to be provided by the host device for the emulation session: and c) enabling each host resource in the plurality of host resources corresponding to a resource in the selected host resource list to be accessible by the emulation server to provide the emulation session.
[0009] In accordance with another embodiment of the invention, there is provided a host device for providing at least one host resource for an emulation session to emulate a computer product provided by an emulation server, the emulation server being separate from the host device. The host device comprises: a host processor; a plurality of host resources comprising at least one of a hardware component and a software component; and a host bridge module configured to: provide a host resource library file including a list of the plurality of host resources available on the host device to the emulation server; receive, from the emulation server, a selected host resource list, the selected host resource list corresponding to a list of resources selected torn the host resource library file to be provided by the host device for the emulation session; and enable each host resource in the plurality of host resources corresponding to a resource in the selected host resource list to be accessible by the emulation server to provide the emulation session.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A preferred embodiment of the present invention will now be described in detail with reference to the drawings, in which:
[0011] FIG. 1 is a block diagram illustrating a host device in communication with an emulation system, in accordance with an example embodiment;
[0012] FIG. 2 is a flowchart illustrating a process for optimizing resources for an emulation session, in accordance with an example embodiment; and
[0013] FIG. 3 is a screenshot of a device selection interface, in accordance with an example embodiment.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0014] The embodiments of the systems, processes and methods described herein can be implemented in hardware or software, or a combination of both Alternatively, these embodiments can also be implemented in computer programs executed on programmable computers (c)ach comprising at least one processor (e.g., a microprocessor), a data storage system (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. For example and without limitation, the programmable computers (referred to below as computing devices) can be a personal computer, laptop, personal data assistant, cellular telephone, smart-phone device, tablet computer, and/or wireless device. For any software components, program code is applied to input data to perform the functions described herein and generate output information. The output information is applied to one or more output devices.
[0015] Each software component or program can be implemented in a high level procedural or object oriented programming and/or scripting language to communicate with a computer system. However, the programs can be implemented in assembly or machine language, if desired. In any case, the language can be a compiled or interpreted language. Each such computer program is preferably stored on a storage media or a device (e.g. ROM) readable by a general or special purpose programmable computer, for configuring and operating the computer when the storage media or device is read by the computer to perform the procedures described herein. The subject system can also be considered to be implemented as a computer-readable storage medium, configured with a computer program, where the storage medium so configured causes a computer to operate in a specific and predefined manner to perform the functions described herein.
[0016] Furthermore, the processes and methods of the described embodiments are capable of being distributed in a computer program product comprising a computer readable medium that bears computer usable instructions for one or more processors. The medium can be provided in various forms, including one or more diskettes, compact disks, tapes, chips, wireline transmissions, satellite transmissions, internet transmission or downloadings, magnetic and electronic storage media, digital and analog signals, and the like. The computer useable instructions can also be in various forms, including compiled and non-compiled code.
[0017] It will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals can be repeated among the figures to indicate corresponding or analogous elements.
[0018] In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. Also, this description and the drawings are not to be considered as limiting the scope of the embodiments described herein in any way, but rather as merely describing the implementation of the various embodiments described herein,
[0019] The various embodiments described herein generally relate to a system (and related methods) for optimizing resources for an emulation session provided by an emulation server in an emulation system. The emulation session is provided for a host device. The host device includes one or more resources that can be available to be used for providing an emulation session. The host device can provide the emulation server with a list of available resources so that the emulation server can select to use any of the resources in that list that correspond to a resource required for providing the emulation session.
[0020] Reference is first made to FIG. 1 , which illustrates a block diagram 100 of a host device 110 in communication with an emulation system 160 .
[0021] As illustrated in FIG. 1 , the host device 110 can communicate with the emulation system 160 over a network 130 . For ease of exposition, only one host device 110 is illustrated in FIG. 1 but it will be understood that one or more host devices 110 can communicate with the emulation system 160 at any given time.
[0022] The host device 110 can generally be any computing device capable of network communication For example, and without limitation, the host device 110 can be a personal computer, laptop, personal data assistant, cellular telephone, smart-phone device, tablet computer, and/or wireless device. The host device 110 can include one or more components or modules that operate based on software and/or hardware. For example, as illustrated in FIG. 1 , the host device 110 includes a host processor 112 , a host bridge module 114 and a resource module 116 .
[0023] The host processor 112 can operate with one or more other modules on the host device 110 for enabling operation of the host device 110 . Also, the host processor 112 can operate with the host bridge module 114 and/or the resource module 116 for identifying resources available at the host device 110 and enabling use of those resources for providing an emulation session.
[0024] The resource module 118 can include one or more software components and/or hardware components. The software components can include computer programs and/or applications that enable functionality on the host device 110 . The software components can operate with and/or enable the hardware components to provide functionality. For example, the software components can include an e-mail client application, a calculator application and/or a camera processing application.
[0025] The hardware components can include any physical components that enable operation of the host device 110 . For example, the hardware components can include a communication module for receiving and/or transmitting data with external components and/or other devices (e.g., via a USB connection, serial port connection, parallel port connection, HDMI port connection, radio-frequency connection, Bluetooth™ connection, a wireless connection, a mobile network connection, audio data connection, video data connection and any other data connections), a storage module (e.g., a hard disk drive, a random-access memory, and/or other computer data storage components), a navigation module (e.g., a Global Positioning System (GPS)), a multimedia module (e.g., a sound card, a video card, etc.), one or more user interface components (e.g., a touch screen, a keyboard, a display, etc.), and/or other modules for providing additional features (e.g., a motion detection module including a Gyroscope, etc.).
[0026] The network 130 can include a mobile network and/or the internet. In some embodiments, the network 130 can be a virtual channel within a remote desktop protocol (RDP) stack.
[0027] The host bridge module 114 can be provided as a software component. For example, the host bridge module 114 can be provided to the host device 110 over the network 130 or a pre-installed program on the host device 110 .
[0028] The host bridge module 114 includes a host bridge application. The host bridge application can be a standalone software application, part of another software application, and/or built on a software development kit (SDK) available on the host device 110 .
[0029] For example, the host bridge application can be provided onto the host device 110 as part of an installation of a mobile application, such as a word processor application, to be emulated on the Android system. When the mobile application is downloaded onto the host device 110 , the host bridge application can be downloaded onto the host device 110 as part of that mobile application.
[0030] The host bridge module 114 can generally operate to identify resources available at the host device 110 and/or to enable one or more of the identified resources to be used by the emulation system 160 for providing an emulation session.
[0031] The resources available at the host device 110 can be provided as a list of resources in a host resource library file. The list of resources will generally include the software and hardware components provided in the resource module 116 . in some embodiments, the hardware components can include a sound card, a camera, a keypad, a GPS module, Bluetooth module, a Near Field Communication module, and one or more other hardware modules, in some embodiments, the software components can include an e-mail client application, a calculator application, and one or more other software modules.
[0032] After the host bridge module 114 generates the host resource library file, the host bridge module 114 can store the host resource library file at the host device 110 in, for example, the storage module.
[0033] In some embodiments, the host bridge module 114 can request permission from a user of the host device 110 before being able to retrieve the list of resources. The host bridge module 114 can request access to the operating system of the host device 110 for retrieving the list of resources.
[0034] The host bridge module 114 can also request permission to access one or more other components available at the host device 110 . For example, the host bridge module 114 can request access to the communication module in order to provide the host resource library file to the emulation system 160 . In another example, the host bridge module 114 can request access to one or more hardware and/or software components within the resources module 116 so that these hardware and/or software components can be used by the emulation system 160 for providing an emulation session.
[0035] When the host bridge module 114 is denied permission by the user, the host bridge module 114 can respond accordingly. In some embodiments, the host bridge module 114 can generate an error message and display the error message on the user interface of the host device 110 . In some further embodiments, the host bridge module 114 can also indicate to the emulation system 160 that any future emulation sessions that are requested by the host device 110 are to rely on resources provided by the emulation system 160 alone.
[0036] In some embodiments, the host bridge module 114 can provide a user interface from which user inputs can be received from a user of the host device 110 for customizing the content of the host resource library file. For example, the user inputs can include an input specifically designating resources that can be used by the emulation system 160 and resources that may not be used by the emulation system 160 . The user inputs can further include an input for manually adding and/or removing resources from the host resource library file. The user input can further include an input for designating one or more resources within the host resource library file to be used for a particular emulation session. The user input can also include an input designating a communication port on the host device and/or communication protocol with which a resource on the host device can send and receive data from the emulation system 160 . The communication protocol can include any known data communication protocols, such as Transmission Control Protocol (TCP)/lnternet Protocol (IP), User Datagram Protocol (UDP), or Stream Control Transmission Protocol (SCTP).
[0037] The host bridge module 114 can designate the communication ports and/or communication protocols for a resource to be shared with the emulation system 160 based on a variety of factors. The variety of factors can include the operating system of the host device 110 , availability of the communication ports on the host device 110 , a level of power consumption by the resource to be used for providing the emulation session, and other operational factors.
[0038] The host bridge module 114 can also provide the host resource library file to the emulation system 160 , By providing the host resource library file to the emulation system 160 , the use and availability of resources that are required for an emulation session can be optimized and enhanced, in order to provide the host resource library file to the emulation system 160 , the host bridge module 114 establishes communication with the emulation system 160 via the network 130 .
[0039] As illustrated in FIG. 1 , the emulation system 160 can include one or more emulation servers 170 . The emulation servers 170 generally operate to provide an emulation session for emulating a computer product as identified in a request received from the host device 110 .
[0040] Each emulation server 170 can be used for providing emulation sessions to the host device 110 . An emulation server 170 can include a server processor, an emulation bridge module, a server storage module, an emulation resources module and a server communication module. For ease of exposition, only emulation servers 170 a, 170 b, and 170 c are illustrated. It will be understood that a fewer or greater number of emulation servers could be provided in the emulation system 160 .
[0041] The emulation system 160 can be a remote system connected to the host device over the network 130 such as the internet or a mobile network.
[0042] The example emulation server 170 a includes a server processor 172 , an emulation bridge module 174 , a server storage module 176 , an emulation resources module 178 and a server communication module 180 . Emulation servers 170 b and 170 c can be similarly configured as the emulation server 170 a.
[0043] The server processor 172 can operate with one or more other modules on the emulation server 170 for enabling operation of the emulation server 170 , Also, the server processor 172 can operate with the emulation bridge module 174 and/or the emulation resources module 178 for determining resources required for providing an emulation session and for determining whether a resource can be provided by the host device 110 .
[0044] The server storage module 176 can store data related to emulations that can be provided by the emulation server 170 a. For example, the server storage module 176 can store one or more computer products to be provided in an emulation session by the emulation server 170 a and also, a corresponding list of resources that are required for emulating any of those one or more computer products.
[0045] The server communication module 180 provides a communication interface for the emulation server 170 a. The server communication module 180 can receive from and/or transmit data to external components and/or other devices.
[0046] The emulation bridge module 174 includes an emulation bridge application. The emulation bridge application enables communication between the host bridge module 114 on the host device 110 and the emulation server 170 .
[0047] As described above, the host bridge module 114 can provide the host resource library file to the emulation system 160 so that the emulation system 160 can optimize use of any resources that can be available at the host device 110 for providing an emulation session. As a result, the emulation server 170 can minimize the resources that the emulation resources module 178 may need to emulate in order to provide an emulation session, and thus, can avoid wasting resources at the emulation server 170 . Also, by using resources available at the host device 110 , the emulation system 160 can extend the functionality and/or utility of an emulation session.
[0048] For example, in an emulation session requiring voice and/or audio data from a user at the host device 110 , such as an emulated application for testing a telephone call or an emulated application involving voice recognition functions, the sound card resource on the host device 110 can be used in order to extend the functionality of that emulation session. In another example, an emulation session can be provided for testing an operability of a communication port, such as an HDMI port, at the host device 110 .
[0049] FIG. 2 is a flowchart 200 illustrating a process for optimizing resources for an emulation session.
[0050] At step 210 , the emulation server 170 receives an emulation session request from the host device 110 .
[0051] The emulation session request can include, at least, an identifier corresponding to a computer product that is to be emulated. In some embodiments, the emulation session request can be provided to the emulation server 170 when the host bridge module 114 receives and/or initializes the host bridge application. In some embodiments, the emulation session request can be provided to the emulation server 170 when the host device 110 receives a user input for initializing emulation of the computer product.
[0052] At Step 220 , in response to receiving the emulation session request from the host device 110 , a communication link can be provided between the host bridge module 114 and the emulation bridge module 174 .
[0053] Generally, the emulation bridge module 174 communicates with the host bridge module 114 over the network 130 . In some embodiments, the communication link can first be established between the host bridge module 114 and the emulation bridge module 174 before any data is provided between the host device 110 and the emulation server 170 . For example, a communication link is successfully established if the host bridge module 114 sends a test signal to the emulation bridge module 164 and that test signal is appropriately returned from the emulation bridge module 164 . In some further embodiments, the host bridge module 114 and the emulation bridge module 164 can continue to send each other synchronization signals in order to maintain the communication link for future data transfer.
[0054] At step 230 , the host bridge module 114 can provide the host resource library file to the emulation bridge module 174 .
[0055] As described above, the host resource library file can be provided to the emulation bridge module 174 via the communication link provided over the network 130 .
[0056] At step 240 , the emulation bridge module 174 determines emulation session resources required for providing the emulation session corresponding to the received emulation session request.
[0057] The received emulation session request includes, at least, an identifier corresponding to a computer product that is to be emulated. Using the computer product identifier provided in the received emulation session request, the emulation bridge module 174 can retrieve from the server storage module 176 a list of resources required for providing the emulation session for that computer product. In some embodiments, the list of resources can be retrieved by the server storage module 176 from an external database.
[0058] At step 250 , the emulation bridge module 174 selects the host device 110 or the emulation server 170 for providing each of the resources required for providing the emulation session.
[0059] For each resource in the list of required resources, the emulation bridge module 174 determines it a corresponding resource is available at the host device 110 from the host resource library file. If the emulation bridge module 174 determines that a required resource corresponds to a resource in the host resource library file, the emulation bridge module 174 can select the resource in the host resource library file so that the host device 110 is selected for providing that required resource. However, if the emulation bridge module 174 fails to identify a resource in the host resource library file that corresponds to a required resource, the emulation bridge module 174 can select the emulation server 170 for providing that required resource. The emulation resources module 178 on the emulation server 170 can instead emulate that required resource.
[0060] In some embodiments, the emulation bridge module 174 provides the host bridge module 114 with a list of resources that the emulation bridge module 174 has selected the host device 110 to provide. On receipt of the list of resources, the host bridge module 114 can respond by initializing the selected resources.
[0061] In some embodiments, the host bridge module 114 can further configure the selected resources to be used for an emulation session. The host bridge module 114 can operate with the resource module 116 so that the selected resources have prioritized access to one or more hardware and software components in the resource module 116 . For example, the host bridge module 114 can operate with a communication module in the resource module 116 so that the selected resources have prioritized access to the communication ports at the host device 110 for communicating with the emulation server 170 . In another example, for an emulation session requiring voice data input from the user, the host bridge module 114 can configure the communication module so that data received by a microphone at the host device 110 has priority.
[0062] In some embodiments, the host bridge module 114 can further configure the selected resources to be used for an emulation session to be prioritize between one or more different emulation sessions. For example, the host device 110 can be connected to two concurrent emulation sessions that both require access to a microphone at the host device 110 , The host bridge module 114 can configure the microphone so that one of the emulation sessions has prioritized access to the microphone over the other emulation session,
[0063] FIG. 3 illustrates a screenshot 300 of a device selection interface 310 for a dictation application provided at an emulation server 170 . It will be understood that the illustrated user interface text and controls are provided as examples only and are not meant to be limiting. Other suitable user interface elements can be used.
[0064] The dictation application requires, at least, a microphone and one or more software components in order to operate. The resources used for providing the
[0065] emulation session of the dictation application is generally illustrated as 320 for resources provided by the host device 110 (“Host”) and generally illustrated as 330 for resources provided by the emulation server 170 (“Server”). As generally shown at 320 , a microphone is available at the host device 110 and has also been selected by the emulation bridge module 174 for use in the emulation session of the dictation application. Similarly, as generally shown at 330 , the software components for providing the dictation application is provided by the emulation server 170 .
[0066] At step 260 , the emulation server 170 provides the emulation session to the host device 110 .
[0067] The emulation server 170 provides the emulation session corresponding to the received emulation session request using resources provided by the host device 110 and the emulation server 170 , as determined at step 250 . It will be generally understood that multiple emulation sessions can be provided on each emulation server 170 as long as sufficient resources are available.
[0068] In some embodiments, the emulation session can be provided using a Software Development Kit (SDK), the host device 110 , an operating system of the emulation server 170 , the host bridge module 114 including a host bridge application, and the emulation bridge module 174 including an emulation bridge application. The emulation session can be provided so that resources at the host, device 110 can be accessible to the emulation server 170 . The emulation session can be enhanced from the limited options otherwise available from the host device 110 .
[0069] In some embodiments, the host bridge module 114 can be installed on the
[0070] host device 110 . When the host bridge module 114 is initialized, the host bridge module 114 operates to search for resources on the host device 110 and to record a current host resource library file. The host bridge module 114 can also designate one or more of the resources on the host device 110 to be shared. The host bridge module 114 can prioritize access to any of the resources that have been designated to be shared between one or more emulation sessions and use for operations at the host device 110 . The host bridge module 114 can designate one or more communication ports on the host device 110 and one or more communication protocols to be used for sharing a resource at the host device 110 . To establish a communication link with the emulation system 160 , the host bridge module 114 can set up and test a synchronization signal by sending the synchronization signal to the emulation bridge module 174 .
[0071] In some embodiments, the emulation bridge module 174 can be installed on one of the emulation servers 170 . When the emulation bridge module 174 is initialized, the emulation bridge module 174 , can accept the synchronization signal from the host bridge module 114 and also receive the current host resource library file from the host bridge module 114 . The emulation bridge module 174 can also indicate to the host bridge module 114 one or more desired resources at the host device 110 to be shared. The emulation bridge module 174 can prioritize access to the one or more resources to be shared from the host device 110 between use by one or more of applications to be provided in an emulation session and use by the emulation server 170 . The emulation bridge module 174 can designate one or more communication ports on the emulation server 170 and one or more communication protocols to be used for using a resource at the host device 110 .
[0072] In some embodiments, the user can select, at the emulation bridge module 174 , one or more resources from the current host resource library file that can be to shared. The user can further select desired prioritization of access to these resources to be shared between use by one or more applications to be provided in emulation sessions and use by the emulation server. The user can further designate a communication interface, such as, e.g., a port and/or protocol, on the emulation server 170 for sharing the resource at the host device 110 .
[0073] In some embodiments, the SDK can be installed on the emulation server 170 . The host bridge module 114 can indicate to the SDK that one or more resources that are to be shared with the emulation server 170 exist at the host device 110 and are accessible through the emulation bridge module 174 . The emulation bridge module 174 can provide an emulation operating system resource interface from which access to the one or more resources that are designated to be shared can be provided.
[0074] In some embodiments, the SDK can be installed in an operating system of a host device 110 . The host bridge module 114 can provide an installation interface line variable for receiving inputs from a user of the host device 110 inputs for indicating that one or more resources can be shared. The resources that can be shared can be provided in an option list. The option list can be presented to the emulation server 170 and can be accessible via the emulation bridge module 174 .
[0075] When the option list is received at the emulation server 170 , the emulation bridge module 174 receives an indication that the resources in the option list (for example, a sound card for an emulation of a smartphone) exists at the host device 110 and therefore, do not need to be provided by the emulation system 160 , the emulation bridge module 174 also receives a notification indicating that the one or more resources in the option list are accessible by the emulation bridge module 174 , regardless of the communication interface of the emulation server 170 (for example, clipped pins to the emulation audio ports, restricted access from the emulation manager).
[0076] In some embodiments, an operating system of the emulation server 170 is designed to enable selections according to installation criteria of the SDK. The standard SDK set up can therefore be enhanced. For example, emulation sessions of applications that would otherwise stop loading due to the absence of a sound card, or an indication that the sound card is off, can now load and seek sound card resources via the emulation bridge module 174 .
[0077] In some embodiments, the emulation bridge module 174 is set up after the host bridge module 114 . The host bridge module 114 can be installed on the host device 110 . The host bridge module 114 reviews the resources available at the host device 110 and records the current host resource library file. The current host resource library file can be accessible by the user of the host device so that the user can designate which of the resources in the resource module 116 can be shared with one or more emulation servers 170 .
[0078] In some embodiments, the host bridge module 114 can also prioritize access to resources selected to be shared with the emulation server 170 between one or more emulation sessions and the host device 110 in accordance with a request received from the user.
[0079] In some embodiments, the host bridge module 114 can permit the user of the user device 110 to designate a communication interface, such as, e.g., a communication port and/or communication protocol, on the host device 110 for sharing the host resource. The types of communication ports can include serial, parallel, Bluetooth, wifi, USB, data, audio, video, networking, and com1. The types of communication protocols can include TCP, UDP, and SCTP.
[0080] In some embodiments, resources can be shared between the communication interfaces selected by the host bridge module 114 and the emulation bridge module 174 . The communication interfaces can be selected from the set up options provided in each of the host bridge module 114 and the emulation bridge module 174 . The SDK kit installation interface line variables can be modified according to the current host resource library file.
[0081] In some embodiments, resources at the host device 110 can be accessed as an extension of a function or an application to be provided by the emulation system 160 depending on a configuration of the emulation system 160 , the host bridge module 114 , and the emulation bridge module 174 . For example, a sound card at the host device 110 can be used in an emulation session as a microphone and/or speaker when testing a telephone application, a voice recognition application, a gaming application, and so on.
[0082] In some embodiments, resources at the host device 110 can be accessed for control by a function or an application to be provided by the emulation system 160 . For example, a HDMI output port at the host device 110 can be accessed for testing the ability of the emulation system 160 to control the HDMI output during an emulation session.
[0083] It will be understood that the systems and methods described above are flexible and can be modified for use with a wide range of communication interfaces, communication ports, and communication protocols and a large variety of host devices 110 , SDKs, emulation sessions.
[0084] The present invention has been described here by way of example only. Various modification and variations can be made to these exemplary embodiments without departing from the spirit and scope of the invention, which is limited only by the appended claims. | Methods and systems for providing an emulation session to emulate a computer product for a host device. A method and system involve providing a communication link between the host device and an emulation bridge module provided on an emulation server separate from the host device; providing a host resource library file including a list of the plurality of resources available on the host device to the emulation bridge module; operating the emulation bridge module to determine emulation session resources required to provide the emulation session; selecting at least one of the host device and the emulation server for providing each required emulation session resource in the emulation session resources required to provide the emulation session: and providing the emulation session using the required emulation session resources provided by at least one of the host device and the emulation server. | 6 |
FIELD OF INVENTION
[0001] The present invention relates to new compositions and methods of manufacture for structural sheathing panels and in particular to panels and processes which reduce the energy required to manufacture such structural sheathing panels when compared to the energy required to manufacture traditional gypsum or wood-based structural sheathing panels.
BACKGROUND OF THE INVENTION
[0002] In the field of building construction, structural sheathing is a crucial element in suitable building design. Structural sheathing may serve many functions associated with the purpose and integrity of the assembly, including strengthening the building to lateral forces; providing a base wall to which finish siding can be nailed; acting as thermal insulation; and, in some cases, acting as a base for further thermal insulation. Structural sheathing, in the form of thin, rigid panels, is nailed directly onto the framework of the building. Some common types of sheathing include wood boards or slats, oriented strand board (OSB) panels, plywood panels, and gypsum panels.
[0003] Before the acceptance of performance-rated cellulose panels such as oriented strand board (OSB), plywood was the sheet product of choice for constructing wood shear walls. Plywood panels are very flexible and appropriate for a variety of building designs. The panel thickness, panel grade, nail type, and nail spacing could be combined in different ways to achieve a wall with the right design strength. In the 1970s, with the advent of performance-rated products based on waferboard technology, plywood was largely replaced with composite wood panels such as OSB. Today, all of the model building codes in the United States and Canada recognize OSB panels for the same uses as plywood on a thickness-by-thickness basis and they are used interchangeably, based on price and availability.
[0004] More recently, gypsum sheathing panels have been used as structural sheathing panels. Gypsum sheathing is most commonly manufactured with a water-resistive treated core but may also be available in a non-treated core. Treated core gypsum sheathing is intended for use as a substrate sheathing under a variety of exterior wall claddings in any climate. Non-treated core gypsum sheathing is intended for use only in dry climates. As with their wood counterparts, both types of gypsum sheathing (i.e. treated core and non-treated core) are designed to be mechanically attached to the outside surface of exterior wall framing using either nails, or screws, or staples. Gypsum sheathing is manufactured in a range of lengths and widths similar to those of both plywood and OSB.
[0005] The sheathing layer is designed with several system properties and requirements in mind. Of particular importance are the shear resistance imparted by the layer, the water vapor permeance of the layer, the weather resistance of the layer, and finally, the environmental impact (and associated greenhouse gases) involved with the manufacture of the sheathing layer. First, an appropriate structural building design requires that the panel reliably transfer shear forces (typically from wind shear or earthquake loads) from the body of the structure to its foundation. The performance of a panel in a building design is subject to many design elements including the material's Young's modulus, the panel thickness, the type and configuration of the structural framing and the type and spacing of the panel fasteners. All of these combine for a rated shear resistance in units of pounds per foot (lb/ft). Materials are tested via American Society of Testing and Materials (ASTM) test methods E2126 or E564. Further information may be found on the Internet at http://www.astm.org.
[0006] A second, important material property of the sheathing panel is the panel's role in the moisture management across the building envelope. The problems associated with excessive moisture in building wall cavities and the resulting mold growth, are well documented in the national outcry over unhealthy buildings and poor indoor air quality. As a result, building science has established best practices for minimizing the probability of mold growth in buildings. Walls between areas of differing temperature are the primary structures for these problems. Preventing condensation is of particular importance with regard to the exterior walls of homes or other buildings, where temperature extremes are likely to be greater than between interior walls. Wetting of exterior building surfaces and rainwater leaks are major causes of water infiltration, but so is excessive indoor moisture generation. Moisture may be present within a structure due to occupancy and use by humans, use of wet materials during construction, air leaks, or transfer from external wall materials.
[0007] A figure of merit for the measurement of the transport of water vapor across a component such as a panel or a wall assembly, is its permeance, or “perms”. One perm is defined as the transport of one grain of water per square foot of exposed area per hour with a vapor pressure differential of 1-inch of mercury (Hg). Vapor pressure is a function of the temperature and relative humidity (RH) of the air to which a test structure is exposed, and may be found in many standard data tables. The vapor pressure at any certain RH is found by the product of the RH and the vapor pressure for saturated air at a certain temperature. For example, at 70 degrees Fahrenheit the saturated vapor pressure is 0.7392 Hg and the vapor pressure at fifty per cent RH is 0.3696. The testing methodology varies depending upon the subject material. Data presented for sheathing panel products is typically taken using the ASTM E96 “dry cup” method. Further information may be found on the Internet at http://www.astm.org.
[0008] The Department of Energy (DOE) and the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) and other building science organizations have established recommended wall designs that specify the proper location of a vapor retarder within the wall. A vapor retarder is defined by the building codes as a material having a permeance rating of 1.0 or less. Wall designs are dependant upon the regional climate of the building. In cooling-dominated climates, it is recommended that a vapor retarder be installed on the exterior of the thermal insulation—at the typical location of the structural sheathing. In hot and humid climates, such as along the Gulf coast and in Florida, the vapor barrier should be placed in this exterior location in the wall. Conversely, in heating dominated climates it is recommended that a vapor retarder be installed on the interior side of the thermal insulation—against the interior wallboard. In mixed zones, climates with both significant heating and cooling requirements, design recommendations suggest the omission of the vapor retarder altogether. If these guidelines are not observed, the structure is at risk of allowing water vapor condensation within the wall cavity and eventual water damage and mold growth. To avoid such an outcome, one must know the permeability of the wall components and use only appropriate materials.
[0009] For example, the rate of water vapor transmission of OSB is approximately two (2) perms. For sheathing grade plywood, of ½ to 1 inch thickness, the transmission rate is approximately ten (10) perms. Gypsum sheathing typically has an average vapor permeance of approximately twenty (20) perms. Therefore, plywood and gypsum are above the accepted minimum water vapor transmission rate of five (5) perms specified for a wall with a “U” value less than 0.25 and a vapor retarder not exceeding one (1) perm installed on the interior side of the framing. A double vapor retarder condition is avoided. However, OSB would be deemed unacceptable in the same assembly.
[0010] A third important material feature is weather resistance. Gypsum sheathing is designed for use as a substrate that is covered by an exterior wall cladding. Local weather conditions will dictate the length of time gypsum sheathing may be left exposed; however, it should perform satisfactorily if exposed to the elements for one month or less. Treated core gypsum sheathing should be covered immediately with a weather-resistive barrier, such as building felt or equivalent, if exposure time will exceed one month or weather conditions will be severe. Plywood can typically endure a similar period of weather exposure, while OSB can not. Non-treated core gypsum sheathing should be covered immediately after installation with a weather-resistive barrier. Gypsum sheathing does not hold peel and stick water barrier well.
[0011] Another final important consideration in the design and manufacture of construction materials is their potential negative environmental impact. Environmental impact can take many forms including the depletion of non-renewable natural resources (such as fossil fuels, for example), the generation of harmful chemicals or compounds, or the creation of greenhouse gasses. For a complete assessment as to the long term suitability of a construction material, the existing offering of sheathing materials should be considered in this context as well.
[0012] Unfortunately, the structural integrity of plywood is dependent upon the inclusion of quality wood laminates harvested from mature, large diameter trees, at least 30 years old. Their manufacture puts stress on old growth forests and existing woodland areas. As a result, much of the U.S. softwood plywood industry has shifted from the Pacific Northwest to the South and Southeast, to pine plantations on private lands. These small pines produce a lower quality panel than from the previously abundant older trees. In addition, their costs have risen over the last decade, making them less desirable as a mainstay construction material. OSB has at least two distinct advantages over traditional plywood panels. First, they do not require old growth forests, or decades old trees for their manufacture. OSB is derived from younger aspen trees of a much smaller relative diameter. Although the aspen wood is not a rapidly renewable resource, it does lessen the OSB's impact of endangered woodlands. Second, OSB extends the use of potentially dangerous resins such as phenol formaldehydes listed by the International Agency for Research on Cancer (IARC) as a potential carcinogen that may be released as an undesirable volatile organic compound (VOC) during the OSB's service life.
[0013] Gypsum sheathing panels do not require the use of wood and therefore do not share the concerns associated with tree harvesting. Instead, the manufacture of gypsum sheathing represents an astounding amount of embodied energy as a construction material. The term ‘embodied energy’ is defined as “the total energy required to produce a product from the raw materials stage through delivery” of finished product. Several of the steps (drying gypsum, calcining gypsum (dehumidification), mixing the slurry with hot water and drying the manufactured boards) involved in the manufacture of gypsum sheathing take considerable energy. Greenhouse gasses, particularly CO 2 , are produced from the burning of fossil fuels and the calcining of certain materials, such as gypsum. Thus the gypsum manufacturing process generates significant amounts of greenhouse gasses due to the requirements of the process.
[0014] According to the National Institute of Standards and Technology (NIST—US Department of Commerce), specifically NISTIR 6916, the manufacture of gypsum sheathing panel requires 8,196 British Thermal Units (BTU) per pound. With an average ⅝′ gypsum sheathing board weighing approximately 75 pounds, this equates to over 600,000 BTU's per board total embodied energy. Other sources suggest that embodied energy is less than 600,000 BTU's per board, while others suggest it may be even more. It has been estimated that embodied energy constitutes over 50% of the cost of manufacture. As energy costs increase, and if carbon taxes are enacted, the cost of manufacturing sheathing panel from calcined gypsum will continue to go up directly with the cost of energy. Moreover, material producers carry the responsibility to find less-energy dependent alternatives for widely used products as part of a global initiative to combat climate change.
[0015] For comparison, the same energy study (NISTIR 6916) found that a total of 18600 BTU's per panel are required for the wood harvesting and manufacture of plywood sheathing. OSB sheathing requires a similar amount of energy in its manufacture. Report NISTIR 6916 calculated 27100 BTU's per panel for OSB sheathing.
[0016] In summary, a product's potential negative environmental impact can take many forms, including a depletion of natural resources such as trees, potable water and materials in short supply, or the negative impact may be in the form of a significant consumption of energy during the product's manufacture and the resulting generation of greenhouse gases from its production.
[0017] Thus, it would be highly desirable to meet all of the performance requirements of a structural sheathing panel while reducing the environmental impact of its manufacture by reducing the harvesting of trees, reducing the use of harmful chemicals, and reducing the generation of dangerous greenhouse gases via a high embodied energy.
SUMMARY OF INVENTION
[0018] In accordance with the present invention, new methods of manufacturing novel sheathing panels (defined herein as “EcoRock™” sheathing panels), are provided. The resulting novel EcoRock sheathing panels can replace plywood, OSB, and gypsum sheathing panels in most construction applications. Sheathing panels formulated and manufactured in accordance with this invention maintain the structural integrity, water vapor permeance, and weather resistance required for building applications. Water vapor permeance is enabled and controlled by the introduction of one or more of various filler fibers. These fibers may be hollow glass fibers and/or alternatively, water soluble fibers. These crucial performance features are maintained while significantly reducing the environmental impact associated with the other existing sheathing materials, thus substantially reducing future harm to the environment.
[0019] This invention will be fully understood in light of the following detailed description taken together with the drawings.
DRAWINGS
[0020] FIG. 1 is a perspective view of a sheathing panel according to a preferred embodiment of the invention.
[0021] FIG. 2 shows an EcoRock sheathing slurry tank 202 with fibers 206 oriented in a preferential direction to allow for optimal water vapor transmission following manufacture.
[0022] FIG. 2A shows a cured EcoRock sheathing brick 212 being cut into slices to create a series of panels with optimal water vapor transmission.
[0023] FIGS. 3 and 3A show an EcoRock sheathing panel 304 molded as a continuous slab designed for further fabrication steps to allow for optimal water vapor transmission and a cross-section of this panel, respectively.
[0024] FIG. 4 shows an EcoRock molded sheathing panel 406 lowered into a liquid bath to dissolve the embedded liquid soluble fibers.
[0025] FIG. 5 shows the EcoRock sheathing panel manufacturing steps which require little energy.
[0026] FIG. 6 shows the EcoRock sheathing panels 100 installed to framed structure.
DETAILED DESCRIPTION
[0027] The following detailed description of embodiments of the invention is illustrative only and not limiting. Other embodiments will be obvious to those skilled in the art in view of this description. The example embodiments are in such detail as to clearly communicate the invention. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; but, on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. Various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention. The detailed descriptions below are designed to make such embodiments obvious to a person of ordinary skill in the art.
[0028] The novel processes and materials described herein for manufacturing a low embodied energy sheathing panel lessen the environmental impact created by traditional processes and materials. In comparison to wood products (such as plywood and OSB) there is no depletion of trees as a natural resource. As an alternative to gypsum, the disclosed processes eliminate the most energy intensive prior art processes in the manufacture of current gypsum sheathing panels such as gypsum drying, gypsum calcining, the generation of hot water, and board drying. The new processes allow a sheathing panel to be formed from non-calcined materials which are plentiful and safe and which can react naturally to form a strong, shear resistant board that is also weather hardy and with acceptable water vapor permeability.
[0029] The new EcoRock sheathing panel contains a binder of one or more of magnesium oxide (MgO), calcium oxide, calcium hydroxide, iron oxide (Hematite or Magnetite) and a solution of alkali phosphate salt (sodium phosphate, potassium phosphate, monopotassium phosphate, tripotassium phosphate, triple super phosphate, calicium dihydrogen phosphate, dipotassium phosphate or phosphoric acid). The selected binder materials, often in conjunction with fillers, are mixed together at the start of the particular EcoRock manufacturing process or processes selected to be used to form the EcoRock sheathing panel or sheathing panels. Prior to the addition of liquids, such as water, this mix of binder and filler powders is termed a “dry mix.” The MgO may be calcined or uncalcined. However uncalcined MgO may be less expensive and provide significant energy savings over calcined MgO. Thus there is no need to use calcined MgO, even though calcined MgO can be used in the EcoRock sheathing panel processes.
[0030] In U.S. patent application Ser. No. 11/652,991 Surace et al. describe novel interior gypsum wallboard replacements using such an EcoRock formulation. While there are many binder ingredients in the Surace et al. panels similar to the binder ingredients used in the present EcoRock sheathing panel, the present sheathing panel as intended for use in building construction has features which optimize the water vapor transmission of the panel, a property which is an important characteristic of sheathing panels. This water vapor transmission capability is not present in the Surace et al. panels.
[0031] Many different configurations of materials are possible in accordance with this invention, resulting in improved strength, hardness, score/snap capability, paper adhesion, thermal resistance, weight, and fire resistance. The binder is compatible with many different fillers including calcium carbonate (CaCO 3 ), wolastinite (calcium silicate,) cornstarch, ceramic microspheres, perlite, flyash, waste products and other low-embodied energy materials. Uncalcined gypsum may also be used as a filler material. By carefully choosing low-energy, plentiful, biodegradable materials as fillers, such as those listed above, the sheathing panel begins to take on the best characteristics of wood-based and gypsum sheathing panels. These characteristics (structural strength, acceptable weight so as to be able to be carried, water vapor permeability, and the ability to be nailed or otherwise attached to other materials such as studs) are important to the marketplace and may be required to make the product a commercial success as a traditional sheathing panel replacement.
[0032] Calcium carbonate (CaCO 3 ), an acceptable alternate filler material, is plentiful and represents an environmentally favorable choice. Cornstarch, made from corn, is plentiful and non toxic. In addition, ceramic microspheres are a waste product of coal-fired power plants, and can reduce the weight of materials as well as increase thermal and fire resistance of the sheathing panels that incorporate these materials. The dry mix can include up to 60% by weight of ceramic microspheres. Such a dry mix may be successfully incorporated in EcoRock sheathing panels. Concentrations of greater than sixty percent (60%) by weight of ceramic microspheres in the dry mix increase cost and can reduce strength below acceptable levels. Fly ash is also a waste product of coal-fired power plants which can be effectively utilized in the dry mix. The dry mix can include up to 80% by weight of fly ash. Such a dry mix has been successfully incorporated into EcoRock sheathing panels; however very high concentrations of fly ash can increase weight, darken the core color, and harden the core beyond a level that may be desirable. Biofibers (i.e. biodegradable plant-based fibers) are used for tensile and flexural strengthening in this embodiment; however other fibers, such as cellulose or borosilicate glass fibers, may also be used. The use of specialized fibers in cement boards is disclosed in U.S. Pat. No. 6,676,744 and is well known to those practicing the art.
[0033] In a preferred embodiment of the present invention, a dry mix of powders plus water is created using the materials listed in TABLE 1 by both volume and weight:
[0000]
TABLE 1
Material
% Volume
% Weight
Notes
Oxide
7.0%
5.4%
Magnesium Oxide
Phosphate
13.0%
16.0%
Monopotassium Phosphate
Filler
11.%
12.0%
Calcium Silicate
Fibers
2.0%
0.50%
Biofibers
Lightener
32.0%
30.0%
Microspheres
Retarder
0.20%
0.20%
Boric Acid
Water
34.8%
35.9%
Water
[0034] Monopotassium phosphate and magnesium oxide together form a binder in the slurry and thus in the to-be-formed core of the EcoRock sheathing panel. Calcium carbonate, cornstarch and ceramic microspheres form a filler in the slurry while the biofibers strengthen the core, when the slurry has hardened. Boric acid is a retardant to slow the exothermic reaction and thus slow down the setting of the slurry.
[0035] In terms of manufacturing steps, the water, equivalent to about thirty six (36%) of the dry mix by weight, is added to the dry mix to form a slurry. The wet mix (termed the “initial slurry”) is mixed by the mixer in one embodiment for three (3) minutes. Mixers of many varieties may be used, such as a pin mixer, provided the mix can be quickly removed from the mixer prior to hardening.
[0036] In order to meet all of the sheathing material requirements, the bulk EcoRock may not have a water vapor permeability acceptable for all wall designs. For this reason, several embodiments of the invention involve fibers or tubes that allow for transmission of water vapor from one surface of the panel to the opposite surface. The tubes can be observed as a number of pores across the panel from one surface to the other surface. A representation of such a porous surface is shown in FIG. 1 in a perspective view.
[0037] FIG. 1 shows a proposed embodiment of the present invention whereby the novel cement mixture is formed into water vapor permeable panels. Panel 100 is of typical construction panel dimensions of approximately 4 feet by 8 feet by ⅝ inch thick, or 4 feet by 12 feet by 1 inch thick, or another set of dimensions typical to the construction industry. The panel 100 features an array of through penetrations (pores) 102 with a prescribed hole diameter and spacing to ensure the proper water vapor transmission while maintaining the structural integrity of panel 100 . Example hole counts are from 50 to 5000 per 4 foot by 8 foot panel. The diameter of the holes ranges from 0.2 mm to 2 mm.
[0038] FIG. 2 shows a proposed embodiment of a manufacturing step for production of panel 100 . A cement slurry 204 is poured into a forming tank 202 . The slurry 204 contains a prescribed number or amount of hollow or soluble fibers 206 . The liquid cement mixture is allowed to cure in the forming tank 202 . The dimensions of the tank are chosen to optimize the manufacturing efficiency and yield of construction panels of typical dimensions from approximately 2 feet by 8 feet to approximately 4 feet by 12 feet. In one embodiment, the tank dimensions could be a height 208 of 26 inches by a width 210 of 97 inches, by tens of feet long, depending only on the total weight constraints. The fibers 206 may be of various lengths and diameters. They may also be straight or bent or curled along their length. In one embodiment, the fibers 206 consist of hollow glass tubes approximately 60 mm long with an inside diameter of 200 microns. Such tubes are available from Accu-Glass of St. Louis, Mo. In another embodiment, the fibers 206 are glass tubes about 150 mm long with an inside diameter of about 1 mm. These tubes are also available from Accu-Glass of St. Louis, Mo. In another embodiment, the fibers 206 may consist of a soluble polymer 60 mm long and 200 microns in diameter. Soluble Polymer fibers are disclosed in U.S. Pat. Nos. 3,066,999, 3,689,469, 4,942,089, 5,181,966, 5,187,226, 6,780,832 and 7,001,976 and U.S. published application No. WO/2003/097703. In another embodiment, the fibers 206 are approximately 150 mm long and approximately 1 mm in diameter. In another embodiment, the fibers 206 may consist of a material such as paraffin with a melting point below 200 degrees Celsius, approximately 60 mm long and approximately 200 microns in diameter. In another embodiment, the fibers are made from another soluble material such as starch as disclosed in U.S. Pat. No. 4,853,168. The low melting point fiber material may be paraffin, olefin, PVA, or another similar material. Many different fiber lengths and fiber diameters are possible in accordance with this invention.
[0039] FIG. 2A shows the cured cement mixture as a single large ingot 212 following extraction from the forming tank. Individual sheathing panels 214 are created by slicing the ingot at prescribed intervals 216 . The interval distance is selected according to the desired panel thickness. It is important to note that the panels 214 have fibers 218 oriented in parallel with the thickness dimension (i.e. the fibers extend through each panel from one surface to the other surface). This allows for transport of water vapor.
[0040] One resulting panel is shown in FIG. 3 . The extended surfaces of sheathing panel 300 show a large number of pores 304 . These are the exposed ends of the filler hollow tubes or soluble fibers 306 . The holes are again of a number and diameter according to the preferred panel permeance of 10-20 perms without allowing the transmission of liquid water. Practical hole diameters range from 0.2 to 2 mm. The panel is shown in cross section in FIG. 3A where the holes 304 and traversing fibers 306 are visible.
[0041] If the fibers consist of a soluble material such as a water soluble polymer, the panel must be dipped in a liquid bath for a selected time to dissolve the fibers. In one embodiment, the fibers are water soluble and the solvent liquid is water. This process is shown in FIG. 4 where a liquid bath 402 , a dissolving liquid (water) 404 and the sheathing panel to be treated 406 are shown in relationship to each other. The panel may be dipped for a time range from seconds to days depending upon the soluble polymer, the solvent liquid, and the physical arrangement (e.g. number and diameter) of the fibers. Alternately, the panels may pass horizontally through a liquid shower or mist as necessary. The panels are fabricated of such materials that dipping the panels in water does not degrade the structural integity of the panels after the water soluble polymer has been dissolved. A suitable fiber that is currently commercially available is one made from polyvinyl alcohol (PVA). These fibers are available from multiple suppliers of polyvinyl alcohol (PVA) including Sinopec Shanghai Petrochemical Company Limited of Shanghai, China, Nantong Yimian Textile Co., Ltd. of Jiangsu, China, Texchem Materials of Subang Jaya, Malaysia, Kuraray Co., Ltd. of Osaka, Japan and others. PVA fibers are in common use in carpets and textiles. Their typical water dissolution temperature is from 20 to 90 degrees Celsius with a dissolving time of several minutes to several hours, depending on their particular chemistry and geometry.
[0042] The processing of the slurry may occur using several different techniques depending on a number of factors such as quantity of boards required, manufacturing space and familiarity with the process by the engineering staff. An example of such a process is given in FIG. 5 .
[0043] In the processes of this invention, an exothermic reaction between the binder components starts naturally once water is added to the dry mix to form a slurry and the exothermic reaction heats the slurry. The reaction time can be controlled by many factors including total composition of slurry, percent (%) binder by weight in the slurry, the fillers in the slurry, the amount of water or other liquids in the slurry and the addition of a retarder such as boric acid to the slurry. Retarders slow down the reaction. Alternate retardants can include borax, sodium tripolyphosphate, sodium sulfonate, citric acid and many other commercial retardants common to the industry.
[0044] FIG. 5 shows the simplicity of the two-step process of this invention: namely mixing the slurry with unheated water and then forming the wallboards from the slurry. An optional third step is shown in FIG. 5 wherein the third step involves dipping the wallboard produced in the second step into a liquid (water if the soluble fibers are water soluble) to remove the soluble fibers thereby to create the desired perm value for the sheathing panel. The actual perm value of the sheathing is a function of the number of soluble fibers, the lengths and diameters of the soluble fibers and the number of the soluble fibers which extend across the complete thickness of the panel. Only a fraction of the total number of soluble fibers will extend across the panel from one surface to the other surface and thereby affect the vapor transmission through the panel. When the soluble fibers which extend from one surface to the other surface of the panel are dissolved, the volume occupied by these fibers then is available to allow the transmission of vapor from one side to the other side of the panel. It should be recognized that even fibers which extend to only one surface of the panel will also be dissolved by the liquid. Some moisture will pass along the channels previously occupied by these fibers and will ultimately diffuse through the remaining portions of the panel to the opposite surface. However, the effect on the vapor transmissivity of the panel is small because the perm rating of the panel is basically controlled by the number of soluble fibers which extend from one surface to the other surface of the panel, for the number of soluble fibers in the slurry used to form the panel being in excess of ten thousand fibers per panel.
[0045] The third step in FIG. 5 can be avoided if the fibers added to the panel are hollow.
[0046] The wallboards can either be formed in molds or formed using a conveyor system of the type used to form gypsum wallboards and then cut to the desired size.
[0047] In the process of FIG. 5 , the slurry starts thickening quickly, the exothermic reaction proceeds to heat the slurry and eventually the slurry sets into a hard mass. Typically maximum temperatures of 40° C. to 90° C. have been observed depending on filler content and size of mix. The hardness can also be controlled by fillers, and can vary from extremely hard and strong to soft (but dry) and easy to break. A range of suitable formulations with varied filler content is given in Table 2. Set time, the time necessary to achieve a slurry strength sufficient to remove the cured slurry (i.e.“cement”) from forming tanks, can be designed from twenty (20) seconds to days, depending on the additives or fillers. For instance, boric acid can extend the set time from seconds to hours where powdered boric acid is added to the binder in a range by weight of 0% (seconds) to 4% (hours). While a set time of twenty (20) seconds leads to extreme productivity, the slurry may begin to set too soon for high quality manufacturing, and thus the set time should be adjusted to a longer period of time typically by adding boric acid. The use of one and two tenths percent (1.2%) by weight of boric acid gives approximately a four minute set time.
[0000]
TABLE 2
Final
mixture
Percentage
strength (psi)
filler by
per ASTM
Filler Material
volume (%)
C109
Dualite Microspheres
0%
7000
1%
3000
2%
1625
3%
1000
5%
450
Fillite 500 Microspheres
0%
7000
10%
4500
20%
2750
30%
2000
40%
900
Perlite
0%
7000
3%
3500
6%
2000
9%
1050
12%
750
[0048] An exothermic reaction will begin almost immediately after removal of the slurry from the mixer and continue for several hours, absorbing most of the water in the slurry into the reaction. Boards can be cut and removed in less than 30 minutes, depending on handling equipment available. All of the water has not yet been used in the reaction, and some absorption of the water will continue for many hours. Within 24-48 hours, the majority of water has been absorbed, with some evaporation occurring as well. This can be accomplished on racks at room temperature with no heat required. Drying time will be faster at higher temperatures and slower at lower temperatures above freezing. Residual drying will continue to increase at higher temperatures, however it is not beneficial to apply heat (above room temperature) due to the need of the exothermic reaction to utilize the water that would thus be evaporated too quickly.
[0049] The resulting boards (the “finished product”) have strength characteristics similar to or greater than the strength characteristics of gypsum sheathing panels, and can be easily installed in the field.
[0050] As a feature of this invention, the ratio of one binder component to the other binder component by weight can be varied to minimize the cost of materials. A combination of 10% of one binder ingredient to 90% of the other has been mixed demonstrating an acceptable exothermic reaction.
[0051] As illustrated in FIG. 6 , the EcoReock sheathing panel 100 is mounted is mounted to the building's structural framing 604 . A typical concrete foundation 602 supports the framing 604 , both constructed in a manner prescribed by the local or national building code. The EcoRock sheathing panel 100 is placed across the exterior face of the framing members 604 and fastened with mechanical fasteners 606 such as nails or screws. The specific type and spacing is determined by local or national building codes. For the purposes of clarity, the array of very small through pore or penetrations 102 across the face of the panel 100 are not shown in this figure.
[0052] Other embodiments of this invention will be obvious in view of the above disclosure. | Sheathing panels are produced by methods which do not require natural resources such as wood and use significantly reduced embodied energy when compared with the energy used to fabricate gypsum sheathing panels. A novel binder, consisting in one embodiment of monopotassium phosphate and magnesium oxide, and combined with various fillers, is incorporated with hollow tubes or water soluble fibers to create a gypsum board-like core which can be formed into a suitable sheathing panel handled and installed in a typical manner. The panel is manufactured to have a desirable shear resistance and water vapor permeability, important performance elements in building envelope design. The manufacturing process results in a panel that does not require mature trees as source material, does not off gas, and involves much lower greenhouse gas emissions than the processes used to make traditional wood or gypsum-based sheathing panels. | 4 |
FIELD OF THE INVENTION
The present invention relates to a process and apparatus for screening and fractionating pulp suspensions.
BACKGROUND OF THE INVENTION
At some point in the process of creating paper from a pulp formed from wood or some other substance, it is often desirable to "screen" the pulp. This term is used to mean the filtration of the pulp to rid it of impurities and undesirable fibers. This screening is done by applying the aqueous pulp suspension or slurry against a screen or other filter device. The fiber that is considered acceptable for papermaking passes through the screen and the undesirable fiber is retained on the screen and rejected.
In addition to, or apart from screening, it is often desirable to fractionate pulp. "Fractionation" is used to mean the process by which pulp is sorted into different fiber lengths. The fractions of pulp resulting from fractionation each contain fibers of relatively uniform length. The process of fractionation is identical to that of screening, with one difference: in fractionation, the fibers are sorted by fiber characteristics, rather than accepted or rejected on the basis of desirability.
One way to categorize the screening/fractionation devices (hereinafter "fractionation devices") in the prior art is by the type of force used to pass the pulp suspension through the screen.
One class of fractionation devices uses the force of gravity by placing the pulp suspension on a screen and collecting the acceptable fiber beneath it.
Another class of fractionation devices uses centrifugal force to pass pulp suspension through the screen. A widely used device of this class may be described as follows: a cylindrical screen is used to filter pulp suspension, and a rotatable shaft is located coaxially through the screen. Attached to the rotatable shaft, extending radially, are one or more blades or foils, whose outer edges are very close to the screen. Pulp suspension is introduced into the cylinder defined by the screen and occupied by the rotatable shaft and blades or foils, and the shaft is rotated. As a result of this rotation, the blades or foils attached to the shaft move the suspension in a circular motion, creating a centrifugal force which pulls the pulp suspension outward. The blades or foils entrain the pulp away from the center of the separation chamber and press it against the screen, through which the smaller particles and fibers escape.
In addition to forcing smaller particles and fibers through the screen, the foils prevent longer fibers from escaping end-first, by the creation of a low-pressure area or "shear force" between the edge of the foils and the screen. This shear force has the effect of pulling any undesirable fibers escaping through the screen back toward the shaft. Since longer fibers require more time to escape than shorter ones, their escape is more likely to be interrupted by the passage of a blade or foil, and the consequent pulling effect of the shear force. As the frequency by which the foils pass a given point on the screen ("tip frequency") increases, the less likely it is for a longer fiber to escape successfully. The tip frequency can be altered either by varying the rotational speed of the shaft, or by varying the number of foils or blades on the shaft.
Multiple stages are often desirable in screening as well as in fractionation applications. "Series screening" is often used to more completely purify a pulp suspension. This process consists of screening the suspension through a plurality of similar or slightly dissimilar devices to ensure the complete removal of undesired elements. Multi-stage fractionation is used when more than two fractions are desired.
A need for improved multi-stage fractionation and screening devices ("multi-stage fractionation devices") has arisen with the development of new processes for producing paper pulp. These processes treat the fibers so that the fibers develop "fibrils," small spiral hairs or threads along the fibers' length.
Conventional multi-stage fractionation devices pump the slurry being treated from stage to stage. Such systems therefore require, between the stages, piping, a pump inlet box, a pump, and equipment for level regulation with an automatic valve at the pressure side of the pump. The mechanical working of the fiber, by pumping from one stage to another, causes some fibrils to come loose from the fibers, degrading the quality of the pulp. The more stages in which the pulp is treated, the more the quality of the pulp is degraded.
The loose fibrils themselves also negatively affect pulp quality. They, together with other small particles, form undesirable "fines," which degrade the quality of the pulp and reduce the capacity of subsequent treating machinery, e.g., dewatering equipment.
Conventional processing also reduces the capacity of dewatering equipment by introducing air, through the open inlet box of each pump, which mixes with the pulp.
Additionally, in conventional multi-stage fractionation devices it is difficult to remove, add, or replace stages. Such operations typically require long periods of "down time."
SUMMARY OF THE INVENTION
The apparatus of the present invention carries out multi-stage fractionation in a completely closed system, whose different stages can be easily replaced, added on to, or taken away. Gravity effects pulp transfer between interchangeable modular stages, supplemented by the action of the separating machinery. Inter-stage pumps are eliminated, avoiding undue mechanical working of the fiber and ensuring maintenance of pulp quality.
Specifically, in a principal aspect, the invention includes an apparatus for screening pulp comprising a housing, means forming a plurality of interchangeable modular compartments in the housing, screening means in each compartment dividing each compartment into an inner separation chamber and an outer filtrate chamber, inlet means for furnishing a pulp suspension to each separation chamber, a rotatable shaft extending through the separation chambers, entrainment means in each separation chamber attached to the shaft for entraining suspension furnished to said chamber during rotation of the shaft, and for causing a first fine fraction of the suspension to pass through the screening means, a coarse fraction outlet leading out of each compartment for discharging a coarse fraction from each separation chamber, a fine fraction outlet leading out of each filtrate chamber for discharging a fine fraction therefrom, and means connecting an outlet of one compartment to the inlet of another, for gravity transfer of suspension.
In another aspect, the invention includes a method for fractionating pulp suspensions which comprises furnishing a pulp slurry to a first separation chamber, forcing a first fine fraction of said slurry through a screen into a filtrate chamber, leaving a second, coarser fraction in said separation chamber, conveying, without substantial mechanical working of the pulp therein, at least one of said first and second fractions to a second separation chamber, and forcing a portion of the slurry in said second separation chamber through a second screen to form a third fraction, leaving a fourth fraction in said second separation chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a vertical cross-section of a two-stage fractionation apparatus of the invention, in which the fine fraction from a first stage is treated further in a second stage.
FIG. 2 is a horizontal cross-section taken along line II--II of FIG. 1, showing one half of the apparatus.
FIG. 3 is a vertical cross-section of a two-stage fractionation apparatus of the invention, in which the coarse fraction from a first stage is treated further in a second stage.
FIG. 4 is a horizontal cross-section taken along line IV--IV of FIG. 1.
FIG. 5 is a horizontal cross-section taken along line V--V of FIG. 3.
FIG. 6 is a horizontal cross-section of a modification of the embodiment shown in FIG. 4, showing one half of the apparatus.
FIG. 7 is a vertical cross-section of an apparatus of the invention which includes three fractionation stages, the second stage of which treats the fine fraction from the first stage, and the third stage of which treats the coarse fraction from the second stage.
FIG. 8 is a vertical cross-section of a modification of the embodiment shown in FIG. 3.
FIG. 9 is a vertical cross-section of a modification of the embodiment shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIGS. 1, 2 and 4, a fractionation device according to the invention comprises a housing 10 forming two interchangeable modular treating compartments 11 and 12, the compartment 11 being placed directly above compartment 12. An inlet chamber 13 is positioned above the compartment 11 and a tangential inlet pipe 14 is provided for delivering a feed stream of pulp slurry to the inlet chamber 13.
Inlet chamber 13 is separated from compartment 11 by a plate 15. A central orifice 16 in plate 15 provides communication between inlet chamber 13 and compartment 11.
Compartment 11 is divided into a central separation chamber 17 and an annular filtrate chamber 18 by a cylindrical screen 19. Compartment 11 further includes a central connecting chamber 20 located at the bottom of the compartment. Screen 19 is seated in a circular channel 21 formed in the lower surface of the plate 15 and in a circular channel 22 formed in a plate 23 defining the bottom of separation chamber 17.
A plate 24 forms the bottom of compartment 11 and the top of compartment 12. A plate 25 having a central cylindrical crown 25a and a side flange 25b is positioned on plate 24 and with plate 23 forms the connecting chamber 20. A cylindrical sleeve 26 rests on the horizontal side flange 25b of plate 25 and supports plate 23. A duct 27 connects the filtrate chamber 18 with the connection chamber 20. A tangential inlet duct 20a (FIG. 4) leads into the connection chamber 20 for supplying diluent liquid thereto.
A series of holes 23a in plate 23 connect separation chamber 17 with the annular space 28 between the crown 25a of plate 25 and the sleeve 26. An outlet pipe 9 permits material from this annular space to be withdrawn from the device.
An orifice 24a in bottom plate 24 permits material from connecting chamber 20 to pass into the lower compartment 12.
The compartment 12 is formed by the cylindrical wall 29 which extends downwardly toward a bottom plate 30. A hat shaped plate 31 having a crown section 31a and a flange section 31b is positioned at the bottom of compartment 12. Its flange section 31b lies on plate 30 and between plate 30 and the bottom of cylindrical wall 29.
A cylindrical screen 32 is positioned in compartment 12 fitting into a channel 33 in the bottom of plate 24 and a channel 34 in the top of plate 31. The screen 32 divides the compartment 12 into a central separation chamber 35 and an outer annular filtrate chamber 36. Holes 37 are provided in plate 31 to connect the separation chamber 35 with a connecting chamber 38 formed inside the crown of hat shaped plate 31. An outlet 39 is provided in the bottom plate 30 for material in chamber 38. An outlet 40 is provided for the filtrate chamber 36. A tangential inlet duct 38a is provided for furnishing diluent liquid to chamber 38.
A hollow shaft 41 is positioned to extend downwardly through the device from inlet chamber 13 through bottom plate 30. Bearings 42 and 43 in the top of inlet chamber 13 and bottom plate 30 accommodate the shaft 41 and packing (not shown) is provided on plates 23 and 31 to seal the passage of the shaft through those plates. An inlet 44 for water or other diluent liquid is provided at one end of the shaft 41 and drive means 45 including, for example, a motor 45a for rotating the shaft are also provided. Holes 46 along the length of the shaft permit liquid to be delivered to the separation chambers 17 and 35.
It will be understood that the various elements described may be attached to another by welding or by bolts, as convenient. For simplicity these have not been shown in the drawing.
Attached to the shaft in each separation chamber 17 and 35, and rotatable with the shaft, are a plurality of entraining devices in the form of radially extending blades or foils 47.
In operation, a pulp slurry is supplied to inlet chamber 13 through inlet pipe 14. It passes via orifice 16 into separation chamber 17, the flow being entirely by gravity. In the separation chamber 17 diluting liquid may be furnished from shaft 41 via holes 46. Shaft 41 is rotated, giving the suspension in separation chamber 17 a relatively high rotational speed, generating centrifugal force on the fibers in the suspension. This, in conjunction with the low pressure zone between screen 19 and the edges of the foils 47, causes a volume of liquid and relatively fine particles to pass through screen 19 into filtrate chamber 18. The fine fraction so created flows from the filtrate chamber 17 via duct 27 into the connecting chamber 20. From chamber 20 the fine fraction leaves the first fractionation stage and is delivered, again by gravity, via orifice 24a into the separation chamber 35 of the second treating compartment 12.
A similar separation occurs in the second treating compartment 12. The finer components of the material from the first compartment are forced through screen 32, but in this case are received as a product through outlet 40.
The coarser fraction left behind in separation chamber 17 passes through holes 23a into annular space 28 and is removed through outlet 9. The coarser fraction in separation chamber 35 passes through holes 37 into connecting chamber 38 and is removed through outlet 39.
The device described in FIGS. 1, 2 and 4 thus permits the fractionation of a pulp stream into three fractions of varying degrees of fineness. The slurry being treated is moved from stage to stage without pumping and the mechanical working of the slurry which pumping entails. Moreover the modular construction of the assembly permits stages to be added or replaced with a minimum of disruption and effort.
Referring now to FIGS. 3 and 5, another fractionation device according to the invention comprises a housing 60, upper modular treating compartment 61, lower modular treating compartment 62, an inlet chamber 63, and a hollow shaft 64, all located in like manner to the analogous components described in FIG. 1.
The differences between the device described in FIGS. 3 and 5 and the device described in FIGS. 1, 2 and 4 lie in the general construction of compartment 61 and in the manner in which entraining devices are attached to the shaft 64.
In FIGS. 3 and 5, inlet chamber 63 is separated from compartment 61 by a plate 65. A central orifice 66 in plate 65 provides communication between inlet chamber 63 and compartment 61. Compartment 61 is divided into a central separation chamber 67 and an annular filtrate chamber 68 by a cylindrical screen 69. A plate 71 forms the bottom of compartment 61 and the top of compartment 62. A central connecting chamber 70, located at the bottom of compartment 61, is defined by plate 71, which forms its bottom, and a hat shaped plate 72 having a crown section 72a, which defines its top and sides. Plate 72 also has a flange section 72b which lies on plate 71.
Screen 69 is seated in a circular channel 73 formed in the lower surface of plate 65, and in a circular channel 74 formed in the top of section 72a of plate 72. Holes 75 are provided in plate 72 to connect the separation chamber 67 with the connecting chamber 70. An orifice 76 in bottom plate 71 permits material to pass from connecting chamber 70 into the lower compartment 62. An outlet 77 is provided for the filtrate chamber 68. A tangential inlet duct 78 is provided for furnishing diluent liquid to connecting chamber 70.
Lower compartment 62 comprises a cylindrical screen 94, a separation chamber 91, a filtrate chamber 89, a connecting chamber 93, an outlet 90 leading from filtrate chamber 89, and holes 92 providing communication between separation chamber 91 and connecting chamber 93, all situated in like manner as their analogous components in compartment 61. An outlet 95 leads from connecting chamber 93 to remove pulp slurry therefrom.
Extending from shaft 64 near the top of upper compartment 61 is a flange 79. A flange 80 extends from shaft 64 near the bottom of separation chamber 67. A cylindrical hub 81 is mounted on flanges 79 and 80, and is rotatable with shaft 64. Entraining devices in the form of radially extending blades or foils 82 are attached to hub 81 and are rotatable therewith.
Hub 81 contains holes 83 which permit liquid to be delivered to separation chamber 67.
Two flanges 84 and 85, a cylindrical hub 86, blades or foils 87, and holes 88 are located in lower compartment 62 in identical fashion to their analogous components in compartment 61.
The remainder of the device described in FIGS. 3 and 5 is identical to the device described in FIGS. 1, 2 and 4, and is likewise identical in operation, except for the flow of filtrate and residual slurry in upper compartment 61 (FIG. 3). After separation of the slurry in chamber 67, the fine fraction in filtrate chamber 68 is removed from the device through outlet 77. The coarse fraction left in separation chamber 67 flows through holes 75 into connecting chamber 70, and is supplied with diluent liquid from inlet duct 78.
From chamber 70, the coarse fraction passes through orifice 76 into lower compartment 62, where it undergoes a further separation. The fine fraction resulting from this separation is removed from filtrate chamber 89 via outlet 90. The coarse fraction left in separation chamber 91 passes through holes 92 into connecting chamber 93 and thence out of the device through outlet 95.
The device described in FIGS. 3 and 5 thus produces from a pulp slurry three fractions of varying fineness, the second stage fractionating the coarse fraction of the first stage.
Referring now to FIG. 6, an interchangeable modular treating compartment according to the invention includes a housing 100, a tangential inlet duct 101 leading into a filtrate chamber 102 for supplying diluent liquid thereto, and a duct 103, substantially tangential to a connecting chamber 104, which connects the filtrate chamber 102 with the connection chamber 104.
The compartment described in FIG. 6 is identical to the compartment described in FIG. 4, except that duct 103 (FIG. 6) leads tangentially from filtrate chamber 102 to connecting chamber 104, and inlet duct 101 leads into filtrate chamber 102 instead of into connecting chamber 104.
In operation, a fine fraction of pulp slurry in filtrate chamber 102 is supplied with diluent liquid via inlet duct 101. Since duct 101 is tangential, the diluent liquid supplied tends to move the pulp slurry in a circular motion. The slurry enters chamber 104 via duct 103, which is tangentially oriented to accommodate and take advantage of the circular motion of the slurry. Since diluent liquid has already been supplied to the fine fraction slurry via inlet duct 101, no inlet duct leads into connecting chamber 104. In all other ways, the compartment described in FIG. 6 operates identically to the compartment of FIG. 4.
Referring now to FIG. 7, another fractionation device according to the invention comprises a housing 110 forming three interchangeable modular treating compartments 111, 112 and 113, compartment 111 being placed directly above compartment 112, and compartment 112 being placed directly above compartment 113. An inlet chamber 114, of identical construction to inlet chamber 13 (FIG. 1), is positioned above compartment 111. A hollow shaft 115 is positioned to extend downwardly through the device from inlet chamber 114 through compartment 113. Hollow shaft 115 is of identical construction to hollow shaft 41 (FIG. 1), except that the former is longer by the height of compartment 113, contains holes 116 to permit liquid to be delivered to compartment 113, and has attached to it a plurality of additional foils 117 which extend into compartment 113.
Compartment 111 is of identical construction to compartment 11 (FIG. 1). Compartment 113 is of identical construction to compartment 12 (FIG. 1). Compartment 112 is of identical construction to compartment 61 (FIG. 3), except that foils 118 in compartment 112 are not mounted upon a hub, but are directly attached to shaft 115.
The device described in FIG. 7 operates similarly to the device described in FIG. 1, except that the former includes an additional fractionation stage. Pulp slurry entering through inlet chamber 114 is separated in compartment 111, the coarser fraction exiting the device through an outlet pipe 119. The finer fraction flows into compartment 112 via an orifice 124, where it undergoes further separation. The finer fraction from the second-stage separation is removed through an outlet pipe 120. The coarser fraction from the second-stage separation flows via an orifice 123 into compartment 113 where it undergoes a third separation. The coarser fraction resulting from the third-stage separation is removed from the device through an outlet pipe 121, and the finer fraction is removed through an outlet pipe 122.
The device described in FIG. 7 thus permits the fractionation of a pulp stream into four fractions of varying degrees of fineness.
Referring now to FIG. 8, another fractionation device according to the invention comprises a hollow shaft 140, an inlet chamber 141, an upper modular treating compartment 142, and a lower modular treating compartment 143, all situated in like manner to the analogous components of the device described in FIG. 2. Inlet chamber 141 is identical to inlet chamber 63 (FIG. 3). Compartment 143 is identical to compartment 62 (FIG. 3). Shaft 140 is identical to shaft 64 (FIG. 3), except that the former is slightly shorter than the latter, since upper compartment 142 lacks a central connecting chamber.
Compartment 142 is divided into a central separation chamber 144 and an outer annular filtrate chamber 145 by a cylindrical screen 146. A plate 147 defines the bottom of compartment 142, separation chamber 144, and filtrate chamber 145. The screen 146 is fixed into position at its bottom by a circular channel 148 formed in the top of plate 147, and at its top by a circular channel 151 found in the bottom of a plate 152, which forms the top of compartment 142.
A plurality of holes 149 in bottom plate 147 connect separation chamber 144 to a separation chamber 150 in compartment 143.
In all other respects, the device described in FIG. 8 is identical to the device described in FIG. 3. The two devices are likewise identical in operation, except that the coarser fraction of slurry from upper compartment 142 (FIG. 8) leaves separation chamber 144 via holes 149 and enters directly into separation chamber 150, without passing through an intermediate central connecting chamber.
Referring now to FIG. 9, another fractionation device according to the invention comprises an inlet chamber 160, an upper modular treating compartment 161, a lower modular treating compartment 162, and a hollow shaft 163.
Upper compartment 161 contains a filtrate chamber 164, a separation chamber 172, and a central connecting chamber 165, all located in like manner to the analogous components of compartment 11 (FIG. 1). A plate 169 forms the bottom of compartment 161 and central connecting chamber 165. The top of connecting chamber 165 is formed by a plate 173, which also forms the bottom of separation chamber 172. The sides of connecting chamber 165 are formed by a cylindrical plate 174. A flange 168 extends from the bottom of plate 174, and lies on bottom plate 169. A cylindrical sleeve 175 is situated outside of and concentrically to plate 174, forming an annular space 176 between the plates. Sleeve 175 rests on flange 168.
A diagonally oriented duct 166 connects filtrate chamber 164 to a separation chamber 167 of lower compartment 162, passing through flange 168, a bottom plate 169, and sleeve 175. Unlike compartment 11 (FIG. 1), no duct exists to connect filtrate chamber 164 to connecting chamber 165.
In all other respects, the device described in FIG. 9 is identical to the device described in FIGS. 1, 2, and 4. It's operation is likewise identical, except that the fine fraction of slurry in filtrate chamber 164 (FIG. 9) does not enter connecting chamber 165. Rather, it directly enters separation chamber 167 of lower compartment 163 via diagonal duct 166. Connecting chamber 165 performs the sole function of supplying diluent liquid to separation chamber 167 via an orifice 170 in bottom plate 169. Diluent liquid is supplied to connecting chamber 165 via a tangential inlet duct 171.
Given the interchangeable nature of the compartments, it will be readily appreciated that other combinations of the different fractionation stages are encompassed by the invention.
The different stages, although preferably placed directly one on top of the other, may be placed in other positions, so long as subsequent stages are placed at sufficiently lower levels than preceding stages to ensure gravitational flow of slurry from one stage to another. | An improved apparatus and process for fractionating pulp suspensions consists of multiple interchangeable modular treating compartments stacked atop one another. Pulp suspension is fractionated in the first compartment, and one of the two resulting fractions flows gravitationally to a second compartment where it is fractionated further. Any of the resulting fractions may be fractionated still further in subsequent compartments as many times as desired. The treating compartments are interchangeable, so removal, addition, or replacement of compartments is relatively easy and quick. Fractionation in each compartment is carried out through centrifugal force. | 3 |
PRIORITY INFORMATION
This application is a divisional application which claims priority from U.S. patent application Ser. No. 11/578,023, filed on Jun. 12, 2007, which claims priority from International Application No. PCT/US2005/011869, filed on Apr. 8, 2005.
FIELD OF THE INVENTION
The present invention is in the field of apparatus and methods used in fracturing an underground formation in an oil or gas well, and producing hydrocarbons from the well or injecting fluids into the well.
BACKGROUND OF THE INVENTION
In the drilling and completion of oil and gas wells, it is common to position a liner in the well bore, to perforate the liner at a desired depth, to fracture the formation at that depth, and to provide for the sand free production of hydrocarbons from the well or the injection of fluids into the well. These operations are typically performed in several steps, requiring multiple trips into and out of the well bore with the work string. Since rig time is expensive, it would be helpful to be able to perform all of these operations with a single tool, and on a single trip into the well bore.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a tool and method for perforating a well bore liner, fracturing a formation, and producing or injecting fluids, all in a single trip. The apparatus includes a tubular tool body having a plurality of radially outwardly telescoping tubular elements, with a mechanical means for selectively controlling the hydrostatic fracturing of the formation through one or more of the telescoping elements and for selectively controlling the sand-free injection or production of fluids through one or more of the telescoping elements. The mechanical control device can be either one or more shifting sleeves, or one or more check valves.
One embodiment of the apparatus has a built-in sand control medium in one or more of the telescoping elements, to allow for injection or production, and a check valve in one or more of the telescoping elements, to allow for one way flow to hydrostatically fracture the formation without allowing sand intrusion after fracturing.
Another embodiment of the apparatus has a sleeve which shifts between a fracturing position and an injection/production position, to convert the tool between these two types of operation. The sleeve can shift longitudinally or it can rotate.
The sleeve can be a solid walled sleeve which shifts to selectively open and close the different telescoping elements, with some telescoping elements having a built-in sand control medium (which may be referred to in this case as “sand control elements”) and other telescoping elements having no built-in sand control medium (which may be referred to in this case as “fracturing elements”).
Or, the sleeve itself can be a sand control medium, such as a screen, which shifts to selectively convert the telescoping elements between the fracturing mode and the injection/production mode. In this embodiment, none of the telescoping elements would have a built-in sand control medium.
Or, the sleeve can have ports which are shifted to selectively open and close the different telescoping elements, with some telescoping elements having a built-in sand control medium (which may be referred to in this case as “sand control elements”) and other telescoping elements having no built-in sand control medium (which may be referred to in this case as “fracturing elements”). In this embodiment, the sleeve shifts to selectively place the ports over either the “sand control elements” or the “fracturing elements”.
Or, the sleeve can have ports, some of which contain a sand control medium (which may be referred to in this case as “sand control ports”) and some of which do not (which may be referred to in this case as “fracturing ports”). In this embodiment, none of the telescoping elements would have a built-in sand control medium, and the sleeve shifts to selectively place either the “sand control ports” or the “fracturing ports” over the telescoping elements.
The novel features of this invention, as well as the invention itself, will be best understood from the attached drawings, taken along with the following description, in which similar reference characters refer to similar parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 through 3 show an embodiment of the invention having a shifting sleeve, some sand control elements, and some fracturing elements, arranged to apply fracturing pressure both above and below a production or injection zone;
FIGS. 4 through 6 show an embodiment of the invention having a shifting sleeve, some sand control elements, and some fracturing elements, arranged to apply fracturing pressure only below a production or injection zone;
FIGS. 7 through 9 show an embodiment of the invention having no shifting sleeve, but with some sand control elements, and some fracturing elements having a mechanical check valve;
FIGS. 10 and 11 show an embodiment of the invention having a solid walled shifting sleeve, some sand control elements, and some fracturing elements;
FIGS. 12 and 13 show an embodiment of the invention having a shifting sleeve incorporating a sand control medium, where none of the telescoping elements have a sand control medium;
FIGS. 14 and 15 show an embodiment of the invention having a shifting sleeve with ports, some sand control elements, and some fracturing elements; and
FIGS. 16 and 17 show an embodiment of the invention having a shifting sleeve with some sand control ports, and some fracturing ports.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1 , in one embodiment, the tool 10 of the present invention has a plurality of telescoping elements 12 , 14 . All of these telescoping elements 12 , 14 are shown retracted radially into the body of the tool 10 , in the run-in position. A first group of these elements 12 have no sand control medium therein, while a second group of these elements 14 have a sand control medium incorporated therein. The sand control medium prevents intrusion of sand or other particulate matter from the formation into the tool body. FIG. 2 shows the telescoping elements 12 , 14 extended radially outwardly from the body of the tool 10 to contact the underground formation, such as by the application of hydraulic pressure from the fluid flowing through the tool 10 . If any of the elements 12 , 14 fail to fully extend upon application of this hydraulic pressure, they can be mechanically extended by the passage of a tapered plug (not shown) through the body of the tool 10 , as is known in the art. After extension of the telescoping elements 12 , 14 to contact the formation, a proppant laden fluid is pumped through the tool 10 , as is known in the art, to apply sufficient pressure to fracture the formation and to maintain the formation cracks open for the injection or production of fluids. This proppant laden fluid will pass through the fracturing elements 12 , but it will not damage the sand control elements 14 . After fracturing, a shifting sleeve 16 is shifted longitudinally, in a sliding fashion, as shown in FIG. 3 , to cover the fracturing elements 12 , while leaving the sand control elements 14 uncovered. Shifting of the sleeve 16 can be by means of any kind of shifting tool (not shown) known in the art. It can be seen that in this case, the fracturing elements 12 are arrayed in two fracturing zones 18 , both above and below the desired production/injection zone where the sand control elements 14 are arrayed. When the upper and lower fracturing zones 18 are fractured, the formation cracks will propagate throughout the depth of the injection/production zone therebetween.
FIGS. 4 through 6 show a similar type of tool 10 to that shown in FIGS. 1 through 3 , except that the fracturing zone 18 is only below the injection/production zone 20 . This type of arrangement might be used where it is not desired to fracture a water bearing formation immediately above the injection/production zone 20 .
FIGS. 7 through 9 show another embodiment of the tool 10 which has no shifting sleeve. This embodiment, however, has a different type of mechanical control device for controlling the fracturing and production/injection through the telescoping elements 12 , 14 . That is, while as before, each of the sand control elements 14 incorporates a built-in sand control medium, each of the fracturing elements 12 incorporates a check valve 22 therein. So, in this embodiment, once the tool 10 is at the desired depth, and the telescoping elements 12 , 14 have been extended, the fracturing fluid passes through the check valves in the fracturing elements 12 into the formation. Thereafter, the hydrocarbon fluids can be produced from the formation through the sand control elements 14 , or fluid can be injected into the formation through the sand control elements 14 .
It can be seen that in FIGS. 7 through 9 , the fracturing elements 12 alternate both above and below the sand control elements 14 , instead of being grouped above or below as shown in two different types of arrangement in FIGS. 1 through 6 . It should be understood, however, that any of these three types of arrangement could be achieved with either the shifting sleeve type of tool or the check valve type of tool.
Other embodiments of the apparatus 10 can also be used to achieve any of the three types of arrangement of the telescoping elements 12 , 14 shown in FIGS. 1 through 9 . First, a longitudinally sliding type of shifting sleeve 16 is shown in FIGS. 10 and 11 . In this embodiment, the shifting sleeve 16 is a solid walled sleeve as before, but it can be positioned and adapted to shift in front of, as in FIG. 10 , or away from, as in FIG. 11 , a single row of fracturing elements 12 , as well as the multiple row coverage shown in FIG. 3 . It can be seen that the fracturing elements 12 have an open central bore for the passage of proppant laden fracturing fluid. The sand control elements 14 can have any type of built-in sand control medium therein, with examples of metallic beads and screen material being shown in the Figures. Whether or not the shifting sleeve 16 covers the sand control elements 14 when it uncovers the fracturing elements 12 is immaterial to the efficacy of the tool 10 .
A second type of shifting sleeve 16 is shown in FIGS. 12 and 13 . This longitudinally sliding shifting sleeve 16 is constructed principally of a sand control medium such as a screen. FIG. 12 shows the sleeve 16 positioned in front of the telescoping elements 12 , for injection or production of fluid. FIG. 13 shows the sleeve 16 positioned away from the telescoping elements 12 , for pumping of proppant laden fluid into the formation. In this embodiment, none of the telescoping elements has a built-in sand control medium.
A third type of shifting sleeve 16 is shown in FIGS. 14 and 15 . This shifting sleeve 16 is a longitudinally shifting solid walled sleeve having a plurality of ports 24 . The sleeve 16 shifts longitudinally to position the ports 24 either in front of or away from the fracturing elements 12 . FIG. 14 shows the ports 24 of the sleeve 16 positioned away from the fracturing elements 12 , for injection or production of fluid through the sand control elements 14 . FIG. 15 shows the ports 24 of the sleeve 16 positioned in front of the fracturing elements 12 , for pumping of proppant laden fluid into the formation. In this embodiment, the fracturing elements 12 have an open central bore for the passage of proppant laden fracturing fluid. The sand control elements 14 can have any type of built-in sand control medium therein. Here again, whether or not the shifting sleeve 16 covers the sand control elements 14 when it uncovers the fracturing elements 12 is immaterial to the efficacy of the tool 10 .
A fourth type of shifting sleeve 16 is shown in FIGS. 16 and 17 . This shifting sleeve 16 is a rotationally shifting solid walled sleeve having a plurality of ports 24 , 26 . A first plurality of the ports 26 (the sand control ports) have a sand control medium incorporated therein, while a second plurality of ports 24 (the fracturing ports) have no sand control medium therein. The sleeve 16 shifts rotationally to position either the fracturing ports 24 or the sand control ports 26 in front of the telescoping elements 12 . FIG. 16 shows the fracturing ports 24 of the sleeve 16 positioned in front of the elements 12 , for pumping of proppant laden fluid into the formation. FIG. 17 shows the sand control ports 26 of the sleeve 16 positioned in front of the telescoping elements 12 , for injection or production of fluid through the elements 12 . In this embodiment, all of the telescoping elements 12 have an open central bore; none of the telescoping elements has a built-in sand control medium.
It should be understood that a rotationally shifting type of sleeve, as shown in FIGS. 16 and 17 , could be used with only open ports, as shown in FIGS. 14 and 15 , with both fracturing elements 12 and sand control elements 14 , without departing from the present invention. It should be further understood that a longitudinally shifting type of sleeve, as shown in FIGS. 14 and 15 , could be used with both open ports and sand control ports, as shown in FIGS. 16 and 17 , with only open telescoping elements 12 , without departing from the present invention.
While the particular invention as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages hereinbefore stated, it is to be understood that this disclosure is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended other than as described in the appended claims. | An apparatus and method for perforating a liner, fracturing a formation, and injection or producing fluid, all in one trip with a single tool. The tool has a plurality of outwardly telescoping elements ( 12, 14 ) for perforation and fracturing. The tool also has a mechanical control device for selectively controlling the fracturing of the formation and the injection or production of fluids through the telescoping elements. | 4 |
BACKGROUND OF THE INVENTION
The U.S. government has rights in this invention pursuant to contract number W-7405-eng-48 between the U.S. Department of Energy and the University of California.
This invention relates generally to grids of the type used in electrical apparatus to control the electrical potential or electrical field configuration at a predetermined region while providing openings for the passage of ions, electrons or the like through the region. More particularly, this invention relates to electrical grids having cooling means for removing heat from the grid during operation.
A variety of electrical systems include one or more grids formed of spaced apart conductors to which a controlled voltage is applied. Such grids enable control of the electrical potential and electrical field configuration across a predetermined region while providing openings through which charged particles or the like may pass through the controlled region.
Grid heating tends to occur in many systems as a result of the impact of high energy charged particles on the grid conductors or from heat received from adjacent high temperature components or from other causes. If not counteracted, overheating may occur and cause a variety of adverse effects. For example, thermal expansion may distort the grid conductors and thereby disrupt critical alignments and spacings with respect to other grids or other components of the system. Unwanted thermionic emission of electrons may occur if the grid material is heated to incandescence and the released electrons may neutralize or otherwise disrupt charged particle beams that are being transmitted through the grid. In extreme cases, structural failure of the grid conductors may occur from overheating.
Avoidance of the above described problems is in part a matter of providing for cooling of the grid conductors. Known grid cooling techniques tend to be inherently inefficient at least in many contexts. A common practice has been simply to rely on the radiation of heat from the grid conductors and on heat conduction along the grid conductors into the support members to which the conductors are attached. Where this is inadequate, it is also a known practice to circulate fluid coolant through the supports or frame to which the grid conductors attach.
Unfortunately, heat elimination by radiation from the grid conductors may be minimal or even negative if surrounding elements are at high temperatures. Heat removal by conduction is also inhibited in most cases as grid elements tend to be very lengthy in relation to their transverse dimensions. That configuration is not conducive to rapid heat tranfer by conduction. While heat removal is increased where a fluid coolant is passed through the frame, prior fluid cooled grid constructions remain basically dependent on the inefficient process of heat conduction along the elongated grid elements.
Consequently known grid constructions do not provide for heat dissipation at a rate which would be desirable in many systems in which grids are employed. Pulse length or duty cycle may have to be limited simply to avoid overheating of grid electrodes.
Under the best of circumstances it is often not possible to maintain an electrical grid at constant temperature and thereby avoid dimensional changes from thermal cycling. In a pulsed electrical apparatus, for example, heat input to a grid occurs primarily during the pulse periods and usually drops substantially during the intervals between pulses. Consequently, in addition to providing for cooling, avoidance of certain of the problems discussed above is also in part a matter of accommodating to expansion and contraction in such a way as to minimize misalignments of grid conductors with other elements in the system which can arise from thermally induced distortion. In many instances some axial extension and contraction of grid conductors is tolerable while lateral displacements of any sizable degree may not be. Accordingly, in some prior grid constructions one or both ends of the grid conductors are slidable relative to the supports and thus are free to move to a limited extent in the axial direction relative to the supporting structure while being rigidly restrained against sideward movement. While this minimizes the more undesirable forms of thermally induced distortion, it also tends to inhibit heat transfer by conduction from the end of the conductor to the support. Thus the problems of limiting heating of an electrical grid and of accommodating to the often inevitable thermal distortions and displacements are closely related matters but efforts to minimize one problem by known techniques may aggravate the other.
As a practical matter the limited capabilities of prior grid structures with respect to resolving problems caused by heat seemingly place undesirable restrictions on the operation of certain systems in which such grids may be employed. Considering a specific example, neutral beam fuel injection systems in certain forms of reactor for initiating, containing and controlling thermonuclear fusion reactions require the extraction of a high energy beam of ions from an electrical plasma generator, an example of such a system being described in U.S. Pat. No. 4,140,943 of Kenneth W. Ehlers, issued Feb. 20, 1979 and entitled "Plasma Generating device with Hairpin Shaped Cathode Filaments". In such systems, the ion beam is extracted from the plasma by an electrical field established by a series of spaced apart grids. Current fuel injection systems of this type are designed to operate with longer ion pulses than has heretofore been the case and conceivably on a D.C. or continuous basis. As a result, grid heating problems of the kind discussed above are greatly aggravated. Known grid constructions do not provide for heat removal at a rate adequate for such usages.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide for more efficient cooling of electrical grid structures.
It is another object of this invention to provide for direct convective cooling of the spaced apart conductors of an electrical grid.
It is still another object of this invention to minimize the undesirable effects of thermally induced distortions in an electrical grid without inhibiting heat dissipation from the grid conductors.
Still a further object of this invention is to provide for the transmission of charged particle beams of very high average energy density through electrical grid structures.
It is still another object of the invention to enable more precise control of electrical potential and electrical field configuration, in a region through which charged particle beams are transmitted, by reducing thermal distortions of grid elements.
Additional objects, advantages and novel features of the invention will be set forth in part in the discussion which 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 obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects and in accordance with an embodiment of the invention as described herein, a fluid cooled electrical grid structure has a plurality of electrical conductors spaced apart to define a plurality of openings through the grid structure and has conductor support means for supporting the conductors while enabling axial extension and contraction of the conductors in response to temperature changes. The conductors are provided with internal flow passages and convective cooling means are provided for directing a flow of fluid coolant through the internal flow passages of the conductors.
In another aspect of the invention, the grid structure includes support means for the conductors which enables individual extension and contraction of each of the conductors relative to the others thereof. In still another aspect, the support means enables independent longitudinal expansion and contraction of each of the conductors while being relatively resistant to movement of the conductors towards each other.
In still another aspect of the invention, the support means includes a plurality of flexible conductor supports to which the conductors are secured, each of the supports being flexible independently of the others and wherein each of the flexible conductor supports has a coolant passage communicated with the internal flow passage of the associated one of the conductors, and wherein the convective cooling means circulates fluid coolant within the conductors through the coolant passages of the supports.
By providing for an internal flow of fluid coolant within the spaced apart conductors of an electrical grid, the invention enables rapid removal of large quantities of heat. The grid may be operated in a very high temperature environment and/or in the presence of charged particle beams of very high energy density with minimal adverse effects from heating. Thermally caused distortions of the grid members are reduced. To the extent that such distortions cannot be eliminated, the invention in a preferred embodiment enables axial extension and contraction of the grid conductors while resisting undesirable lateral distortions and this is accomplished without interfering with the highly efficient convective cooling. Consequently, in the preferred embodiment, grid conductor locations may be maintained within predetermined tolerances under severe operating conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings which are incorporated in and form a part of the specification, illustrate preferred embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:
FIG. 1 is a perspective view of an electrical grid structure in accordance with an embodiment of the invention with the fluid coolant circuit being depicted diagrammatically.
FIG. 2 is a broken out side view of a charged particle accelerator for producing a high energy ion beam and which includes a series of charged electrical grids in accordance with embodiments of the invention.
FIG. 3 is a plan view of a portion of the electrical grid structure of FIG. 1 and which further depicts, in schematic form, details of the fluid coolant circuit for the grid structure.
FIG. 4 is a section view of a portion of the grid structure of FIG. 3 taken along line IV--IV thereof.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the present preferred embodiment of the invention, which is illustrated in the accompanying drawings.
Referring initially to FIG. 1, an electrical grid 11 in accordance with an embodiment of the invention includes a plurality of electrical conductors or rails 12 which are spaced apart to define a series of openings 13 through the grid to allow passage of ions, electrons or the like through the grid region. Most typically, as in this example, the portion of the grid 11 which includes conductors 12 and openings 13 is planar and thus the conductors 12 are linear and disposed in parallel relationship with each other although other grid configurations and thus other conductor configurations may be required in some instances. In the present example the region of the conductors 12 and openings 13 is rectangular and thus the conductors 12 are each of equal length although the invention is adaptable to other grid geometries by utilizing spaced apart conductors having differing lengths.
The grid 11 further includes support means 14 for the conductors 12 for securing the conductors in place in the grid structure and which provide for mounting of the grid in the apparatus in which it is to be used. As will hereinafter be described in more detail, the support means 14 also enables individual movement of each of the conductors 13 relative to the others thereof. For this purpose, the support means 14 includes a plurality of flexible support elements 16 of which an individual one is situated at each end of each of the conductors 13.
Also in accordance with the invention, convective cooling means 17 are provided for directing a flow of fluid coolant through conductors 13 as will also hereinafter be described in more detail.
Grids 11 embodying the invention may be employed in a variety of different types of electrical apparatus and the configuration of the support means 14 may be varied to accommodate to the specific context in which the particular grid 11 is used. Referring now to FIG. 2 the grid 11 of the present example was designed to function as one of a series of essentially similar grids including additional grids 18, 19 and 21 which are situated within an ion beam accelerator 22 of the general type described in the hereinbefore identified U.S. Pat. No. 4,140,943.
The accelerator 22 is a component of a neutral beam fuel injector for systems of the type which initiate and magnetically contain controlled thermonuclear fusion reactions for power production or other purposes. In this context the grids 11, 18, 19 and 21 are situated within an evacuated cylindrical insulator 23 between an electrical plasma generator 24 and an ion beam output tabulation 26. Grid 18, termed the source grid, is adjacent plasma generator 24 while grids 19, 11 and 21 respectively constituting a gradient grid, suppressor grid and exit grid are progressively more distant from the plasma generator in the direction of the output tabulation 26. The final or exit grid 21 is electrically grounded while a pulsed direct current high voltage source 27 applies a high positive voltage to a source grid 18, a somewhat smaller positive voltage to gradient grid 19 and, to enhance beam focussing, a relatively small negative voltage to the suppressor grid 11.
In this example, the voltages applied to grid 18, 19 and 11 are respectively +120 kV, +100 kV, and -2 kV. Plasma generator 24, into which hydrogen or other gas is admitted, is at the same high positive potential as source grid 18. Thus the series of grids, 18, 19, 11 and 21 electrostatically extract and accelerate positive ions of hydrogen or other elements from the plasma generator 24 and cause a high energy beam 28 of such ions to be directed into the output tabulation 26 for delivery to the fusion reaction containment apparatus through an ion neutralizer.
To optimize the ion extraction and acceleration process and to minimize ion beam disruption and heat generation from ion impacts on components of the system, the corresponding conductors 12 of the successive grids 18, 19, 11 and 21 should be maintained in alignment with each other and with predetermined spacings from each other. As plasma generator 24 produces a substantial amount of heat and as ion impacts on components of the grids cannot be wholly avoided, grid heating occurs in operation. This in turn tends to cause thermally induced distortions and displacements of the conductors 13 that interfere with maintenance of the preferred spacings and alignments. Referring again to FIG. 1, the grid 11 construction including convective cooling means 17 minimizes such effects and optimizes efficiency of the beam production process.
With reference to FIG. 1, in order to accommodate to the above described specific use context, the support means 14 of the grid 11 of this example has a circular frame member 29 with a central opening 31 which is of rectangular configuration to conform with that of the grid conductors 12 and grid openings 13 although the opening 31 is preferrably larger than the area occupied by the grid conductors.
Conductor support elements 16 are parts of a conductor mounting assembly 32 having a flange portion 33 that conforms in configuration with frame member 29 and which is secured to the frame member by suitable means such as screws 34. Support elements 16 in this example extend outward from the flange portion 33 of the mounting assembly 32 and are arranged in first and second columns 16a and 16b respectively which extend along opposite ends of the conductors 12. The support elements 16 of each column 16a, 16b are in side by side parallel relationship with each other and are preferrably angled relative to frame member 29 to cause the two columns to be somewhat convergent in the outward direction from the frame member. A separate one of the support elements 16 is adjacent each end of each of the conductors 12. As may best be seen by reference to FIG. 3, each end of each conductor 12 is secured to the adjacent one of the support elements 16, close to the outer extremities of the support elements, the ends of the conductors being brazed to the support elements in this example as this facilitates replacement of a conductor in the event of burnout. The thin slots 36 between adjacent ones of the support elements 16 enable independent flexing of each such support element relative to the adjacent ones.
Referring now to FIG. 4, the support elements 16 in this example are formed of a resilient electrically conductive metal such as stainless steel for example and to provide the degree and kind of resilient flexibility which are desired, a notch or recess 37 is cut out of each such support element to provide an inner wall portion 38 of reduced thickness relative to the other portions of the support element, the recess being situated close to flange portion 33 of the conductor mounting assembly 32 and away from the associated grid conductor 12. Thus as indicated by dashed line 16' in FIG. 4, the support element may flex outwardly and inwardly, primarily at wall portion 38, to accommodate to thermally induced axial expansion and contraction of the associated grid conductor 12 while being relatively resistant to lateral displacements of the grid conductor towards the adjacent grid conductor. The degree of flexing depicted by dashed line 16' in FIG. 4 is greatly exaggerated, for clarity of illustration, relative to what typically occurs in the course of operation, deflections of small fractions of a millimeter being more typical.
Referring again to FIG. 1, the conductor mounting assembly 32 further includes a pair of conductive endwalls 39a and 39b which extend outward from flange portion 33 of the assembly adjacent opposite ends of the two columns 16a and 16b of support elements 16, the endwalls being parallel to the grid conductors 12. Endwalls 39a and 39b each have an edge 40 adjacent an end one of the conductors 12, the edge being angled to extend towards and partially cover the adjacent conductor.
To facilitate manufacture, the conductor mounting assembly 32 is formed of four separate components having juxtaposed parallel end surfaces. The four components include first and second conductor mounting members 32a and 32b respectively and the endwall members 39a and 39b. Preferably, one half of the conductors 12 and support elements 16 are on one member 32a and the other half of the conductors and support elements are on the other member 32b.
The construction of the grid 11 as described to this point provides for positive securing of the ends of the grid conductors 12 to support elements 16 while accommodating to axial growth and shrinkage of the conductors from thermal cycling. In order to reduce such dimensional changes and to enable operation of the grid 11 under more severe temperature conditions than would otherwise be practical, the convective cooling means 17 directs a flow of fluid coolant which may typically be water, into each support element 16 at one end of the grid conductors 12. The flow then passes through each of the grid conductors 12 and is discharged through the support elements 16 at the opposite ends of the conductors.
Considering the convective cooling means 17 in more detail, with reference to FIG. 3, the grid conductors 12 are hollow tubes and thus each such conductor has an internal flow passage 41 extending axially between the ends of the conductor. Coolant from a reservoir 42 is delivered by a pump 43 to inlet manifold chambers 44 in the flange portion 33 of each conductor mounting member 32a and 32b through an adjustable flow control valve 46 and flow line 47. To smooth pressure pulsations, an accumulator 45 is communicated with the outlet of pump 43.
Referring to FIG. 4 in conjunction with FIG. 3, each of the support elements 16 of column 16a has an internal coolant passage 48 communicated with the one of the inlet manifold chambers 44 which is in the same conductor mounting member 32a or 32b. The coolant passage 48 of each support element 16 communicates with the internal flow passage 41 of the grid conductor 12 which the element 16 supports.
As seen in FIG. 4 in particular, the portion of the coolant passage 48 of each support element 16 which extends across the recess 37 of the support element is formed by an extendable and contractable fluid transmitting element 51 which accommodates to the previously described flexing of the support element about the reduced thickness portion 38. In the present example the extendable and contractable fluid transmitting elements 51 are hollow tubular bellows having ends brazed to the opposite walls of the recesses 37.
Referring again to FIG. 3, the flexible support elements 16 of the column 16b at the opposite ends of the grid conductors 12 are of the same construction described above and transmit the fluid coolant flow to an outlet manifold chambers 52 in the opposite flange portions 33 of the conductor mounting members 32a and 32b.
In the present example of the invention the fluid coolant is returned to reservoir 42 for recirculation through the grid. For this purpose a return flow line 53 communicates outlet manifold chambers 52 with reservoir 42 through a flow meter 54, a back pressure valve 56 and heat exchanger 57 all of which may be of known constructions. Back pressure valve 56 is of the form which constricts or in extreme cases blocks the return flow path 53 to the extent necessary to maintain a predetermined minimum pressure within the internal flow passages 41 of the grid conductors 12. This assures that coolant is always present in the grid conductors 12 and inhibits the formation of steam pockets or films within the grid conductors that can otherwise reduce heat transfer into the fluid coolant. Heat exchanger 57 recools the fluid coolant for recirculation through the grid 11. Where the coolant is water as in this example, it is advantageous if at least a portion of the return flow from heat exchanger 57 to reservoir 42 is diverted through a demineralizer and oxygen scrubber 58 which may be of known construction. This reduces corrosion and possible clogging of flow paths in the fluid coolant circuit. For similar reasons it is preferable that the reservoir 42 be of the type which is charged with an inert gas such as nitrogen rather than with air.
As the grid 11 may be operated at very high voltages at least in some cases, and as may be seen by reference to each of the figures, it is advantageous in such contexts if the various external edges, corners and the like of components of the grid are formed with rounded contours to the extent possible as this acts to inhibit arcing and corona discharges. Referring to FIGS. 1 and 4 in particular, avoidance of sharp external edges in the region of the recesses 37 and bellows 51 of the support elements 16 is provided for by closure means which in this example are flat rectangular cover plates 59 that also serve to protect the bellows 51 from possible mechanical damage or possible damage from stray electrical plasma. Cover plates 59 are engaged in the support elements 16 in a manner which does not block the desired flexing of the support elements. In particular and as may be seen in FIG. 4, opposite edges of the cover plates are beveled and slidingly engage in matching grooves 61 and 62 which extend along the opposite facing surfaces of support element recesses 37. Although not apparent in FIG. 4 because of the scale of the drawing, the depth and spacing of the grooves 61 and 62 is slightly greater than is required simply to receive the cover plate 59 so that the support element 16 may flex in the manner indicated in an exaggerated fashion by dash line 16' without constraint by the cover plate. As may be seen in FIG. 1, an individual one of the cover plates 59 in this example extends along one half of the support elements 16 of each column 16a and 16b. The cover plates 59 are implaced prior to fastening of the conductor mounting members 32a and 32b to frame member 29 and after assembly of the grid 11, the cover plates are held in place by abutment against each other and against end walls 39a and 39b.
Certain characterisics of the grid 11 as herein described are adaptations to the particular specific usage of the described grid as depicted in FIG. 2 and the construction may be varied to adapt to usages in other contexts. Thus in the above described embodiment, the length of the support elements 16 and the angling of such support elements and also the outer diameter of the grid 11 as a whole and the length of the grid conductors 12 have been selected to adapt to the preferred positions and spacing of the several grids 18, 19, 11 and 21 within the ion beam source 22. In this particular context, the preferred grid positions are such that the grids 18, 19, 11 and 21 are of progressively smaller extent with progressively shorter grid conductors 12 but also having progressively longer support elements 16 so that the several grids may be disposed in a nested assembly of grids. Other variations in configuration may be made to accommodate to other specific usages.
In operation, with reference to all figures of the drawings, heat produced within the grid 11 or received from external sources is efficiently removed from the grid by the circulating fluid coolant which provides for direct convective heat transfer within the grid conductors 12. Insofar as the temperature of the grid conductors 12 cannot be maintained constant, dimensional growth and contractions of the grid conductors 12 are accommodated to by flexing of the support elements 16 notwithstanding the fact that the grid conductors are positively secured to the supporting structure at each end. Continuity of the fluid coolant circuit is maintained during such flexing of the support elements by the bellows 51 which expand or contract as necessary to accommodate to the movement. While enabling axial expansion and contraction of the grid conductors, the support elements 16 resist lateral displacements of significant extent such as might interfere with critical alignment of the grid conductors with those of other grids or other components of the system.
The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modification and variations are possible in the light of the above teaching. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical application and thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular uses contemplated. It is intended that the scope of the invention be defined by the claims appended hereto. | Undesirable distortions of electrical grid conductors (12) from thermal cycling are minimized and related problems such as unwanted thermionic emission and structural failure from overheating are avoided by providing for a flow of fluid coolant within each conductor (12). The conductors (12) are secured at each end to separate flexible support elements (16) which accommodate to individual longitudinal expansion and contraction of each conductor (12) while resisting lateral displacements, the coolant flow preferably being directed into and out of each conductor through passages (48) in the flexible support elements (16). The grid (11) may have a modular or divided construction which facilitates manufacture and repairs. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to ophthalmic lens surfacing tools with particular reference to means for adapting blocked lenses to lens surfacing machinery.
2. Description of the Prior Art
Blocked ophthalmic lenses having semifinished surfaces requiring final precision grinding and polishing are traditionally pressed against preformed tools (laps) and oscillated thereover with force applied to the block. The block being customarily aligned with the optical center of the lens and thereby geometrically decentered in cases of larger lens sizes results in forces applied to the block being unevenly distributed over the lens-tool surfacing interface. This in turn causes uneven grinding and polishing of the lens surface. Uneven pressure in grinding, tends to introduce prismatic error into the ophthalmic correction desired to be provided by the finished lens while uneven pressure during polishing produces areas of incomplete finishing where least pressure is applied and/or requires prolonged polishing cycles. Incomplete polishing produces what is often referred to as "gray" areas rendering the lenses consumer rejectable while lengthy polishing times uneconomically tie up both equipment and manpower.
The problem being identifiable as a need to apply pressure uniformly over a lens-tool surfacing interface has heretofore lacked a practical solution. For example, deblocking after lens surface milling or generating and reblocking on geometrical center for fine grinding (lapping) and polishing would be unduly time consuming and uneconomical.
Lens blocking methods and apparatuses such as are disclosed in U.S. Pat. Nos. 2,603,922 and 2,748,548 for example suggest that more than one recess may be provided in a lens block for reception of block holding means during lens grinding. These references, however, fail to offer or suggest the universality needed to accurately geometrically center applied grinding or polishing forces in decentered blocking situations.
Accordingly, it is a principle object of the present invention to accomplish universal geometrical centering and distribution of grinding and polishing forces uniformly over lens-tool surfacing interfaces in all situations of lens block decentering normally encountered in the art.
To this end, it is an object of the invention to provide universally adjustable lens block adaptor means designed to receive and direct lens surfacing pressure geometrically centrally and uniformly over a lens-tool surfacing interface.
Other objects and advantages of the invention will become apparent from the following description.
SUMMARY OF THE INVENTION
The foregoing objects and their correlaries are accomplished by the provision of a universally adjustable lens block adaptor designed to receive and distribute a lens surfacing pressure uniformly over a lens-tool interface in grinding and polishing operations performed with preformed tools more particularly of the type known and referred to in the art as laps.
In the usual fashion of placing a surface of a lens to be fine ground and polished against a preformed lap for oscillation over the surface of the lap during application of a grinding or polishing medium thereto, the lens has thereon the block originally used to rough grind, i.e. mill or generate, the surface to be finally worked according to the present invention. As is customary, such a block is centered with the intended optical center of the ophthalmic lens to be produced from the blank and as in most cases encountered in present day practice, optical centering of the block results in its being geometrically decentered. Accordingly, application of a grinding and polishing force to such a decentered block results in uneven distribution of the applied force over the lens-tool surfacing interface. This in turn causes uneven grinding and polishing during the final lens surfacing operation. In fine grinding, a resulting greater removal of lens material beneath the geometrically decentered block than diametrically oppositely thereof introduces prismatic error into the ophthalmic correction intended to be provided by the finished lens. In similar fashion, an uneven pressure at a lens-tool surfacing interface during final polishing tends to produce incompletely finished areas wherever least pressure is applied and/or require unduly prolonged polishing times, i.e. of sufficient duration to polish out these areas under least pressure so as to prevent occurrence of what is referred to in the art as "gray" areas.
The universally adjustable adaptor of the present invention comprises a first member designed to be readily detachably applied to the customary lens block and an overlying second member which may be selectively adjusted in all lateral directions over the first member to a point where it becomes centered with the geometrical center of the lens. With this adaptor, a force applied centrally to its second member will be directed geometrically centrally against the lens blank and evenly distributed over the lens-tool surfacing interface. Adjoining faces of the first and second members are specially knurled or otherwise provided with interlocking protrusions and recesses respectively to prevent their relative lateral and rotational displacement following the aforesaid adjustment and application of a grinding and/or polishing force thereagainst.
Details of the invention will become more readily apparent from the following description when taken in conjunction with the accompanying drawings.
IN THE DRAWINGS
FIG. 1 is a diagrammatic illustration, in front elevation, of a spectacles frame which will be used hereinafter to demonstrate the purpose and accomplishment of the present invention;
FIG. 2 is a top plan view of a blocked lens blank which is typical of a workpiece to which the invention has particular applicability;
FIG. 3 is a partially cross-sectioned diagrammatic illustration of a typical lens surface generating operation following which fine grinding and polishing according to the present invention is required;
FIG. 4 is a fragmentary partially cross-sectional view of an arrangement of blocked lens and tool used in prior art fine grinding and polishing operations and wherewith the present invention, as depicted in subsequent figures of these drawings, can be readily demonstrated and understood;
FIG. 5 is a similarly partially cross-sectioned illustration of an arrangement of blocked lens and tool incorporating a preferred embodiment of the invention;
FIGS. 6 & 7 are plan views respectively of the normally interfacially connected surfaces of the lens block adaptor which is illustrated in the arrangement of the FIG. 5 apparatus;
FIG. 8 is an enlarged fragmentary cross-section view of the lens block adaptor; and
FIGS. 9 and 10 are similar greatly enlarged fragmentary cross-sectional view of modifications of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more particularly to FIG. 1, there is diagrammatically illustrated in full lines a pair of spectacles 10 including ophthalmic lenses 12 which for purposes of illustration only have been shown as incorporating near vision segments 14.
In order to illustrate as simply as possible situations in the art which create the particular difficulties in finishing ophthalmic lens surfaces which are overcome by the present invention, lenses 12 have been depicted as circular and as having geometrical centers 16 which are coincident with their respective optical centers and spaced apart a distance PD equal to the intended wearers interpupillary distance. While this would be the ideal situation for fitting ophthalmic spectacles to a patient, it should be understood that it is extremely rare for ophthalmic lens finishing and spectacles fitting to bring the geometrical centers of lenses into coincidence with their optical centers and at the same time have optical centers spaced a distance apart exactly equal to the patients interpupillary distance, i.e. after fitting with bridge 18 over the nose of a patient.
More usual is the situation where a lens geometrical center is displaced from its optical center, the optical center being the point on a lens intended to be supported directly in front of or coaxially with a patients eye and where meridians of cylinder and spherical correction intersect. Optical center decentration which is the more usual and nearly always occurring situation in present day ophthalmic optics is demonstrated in FIG. 1 by dot-dash outline which represents a lens 20 of greater diametral dimension than either of lenses 12.
It can be seen that for a practitioner to fit a patient with an interpupillary distance PD using bridge 18, it would be required that the optical center of lens 20 be coincident with center 16 of lens 12 which is to be replaced by lens 20. This accordingly displaces the optical center of lens 20 from its geometrical center 22.
Since, as pointed out above, it is essential that prescriptive surface curvatures to be provided on a lens such as lens 20 be centered with the intended optical center of the lens (i.e. the apex of a spherical surface to be produced or the intersection of spherical and cylinder meridians of a toric surface to be produced) it becomes necessary to block the lens on optical center. In this respect, lens 20 is shown in full line illustration in FIG. 2, as having block 24 concentric with optical center 26. Lens 20 has geometrical center 22.
Since it is immaterial to the present invention as to how block 24 may be formed and/or applied to lens 20 and the various techniques usually used such as casting a block directly in place with low temperatures melting alloys or cementing preformed blocks thereinplace, details of blocking procedures per se will not be discussed. Those interested in such details however may refer to U.S. Pat. Nos. 2,580,507; 2,253,954 and 3,195,197; 3,118,198.
It is to be understood that use of the term "lens" herein is intended to include the blank of either glass or plastic from which the finished ophthalmic lens product is formed.
Having blocked a particular lens such as lens 20 of FIG. 2 to be surface finished, it is traditionally first rough ground to approximately its desired meniscus configuration, whether spherical or toroidal. Exemplary of such an operation is the arrangement depicted in FIG. 3 wherein blocked lens 20 is supported by block 24 in a machine tool holder 28. Generating of the exposed surface of lens 22 to curvature 30 is then accomplished by swinging a conventional cutting tool T about point 32 at a radial distance R equal to the curvature desired along one meridian, e.g. curvature 30, of lens 20 while the angular disposition (angle a) of tool T relative to axis X determines the radius of curvature produced in a second meridian normal to that of curvature 30. This lens generating operation is typical of one commonly used in the art and described in U.S. Pat. No. 2,548,418, for example. While the surface curvature desired for final ophthalmic correction is closely approximated by this operation it is as is well known in the art, attended by eliptical error resulting from the angular presentation of tool T.
Removal of this eliptical error by fine grinding of the resulting generated surface 34 and polishing requires separate surfacing operations to which the present invention is especially directed.
For a clearer understanding of problems overcome by the present invention the arrangement used heretofore for final lens grinding and polishing is depicted in FIG. 4. A tool holder 36 supports tool (lap) 38 having its surface 40 preformed to precisely the finished shape desired upon surface 34 of lens 20. Tool 38 is engaged by blocked lens 20 substantially as illustrated. Blocked lens 20 is oscillated over surface 40 while an abrasive slurry selected for grinding or a metallic oxide slurry selected for polishing is applied to the lens 20 - tool 38 interface. The operation requires the application of pressure to the lens-tool interface by means of a force F applied to surfacing machine drive pin P and block 24 during movement of lens 20 over tool 38.
As it can be seen in FIG. 4 the force F applied to block 24 is displaced from the geometrical center 22 of lens 20. It is displaced to one side of axis Y of lens 20 by an amount approximately equal to distance z. Accordingly the distribution of the pressure resulting from force F over the lens 20 - tool 38 interface is nonuniform. It is greatest beneath block 24 and least at the extreme diametrically opposite side of lens 20.
As illustrated by dot-dash line 42, a greater extent of fine grinding and/or polishing will take place beneath lens block 24 or adjacent the edge of lens 20 nearest thereto while less grinding or polishing action will be effected diametrically oppositely of block 24, i.e. adjacent the right side of lens 20 as it is illustrated in FIG. 4.
In the case of a fine grinding operation wherein a slurry of emery particles or other abrasive means is applied to the lens 20 - tool 38 interface, the resulting greater wearing away of surface 34 beneath lens block 24 which is depicted by line 42 will produce a prism error effect in the final lens product. In similar fashion but with less wearing away of lens surface 34, the use of a metallic oxide polishing medium will produce earlier finishing beneath lens block 24 and tend to leave relatively unfinished portions or "gray" areas beneath the segments of the lens 20 - tool 38 interface which receive less pressure, e.g. adjacent the right hand edge of lens 20 as it is depicted in FIG. 4.
DETAILS OF THE INVENTION
In overcoming the drawbacks of prior art lens fine grinding and polishing operations such as that illustrated in FIG. 4, the invention contemplates an incorporation of a two part lens block adaptor A, FIG. 5. The tool holder, tool or lap, lens and block depicted in FIG. 5 are intended to represent the parts already shown in FIG. 4 and accordingly, are identified by the same reference numerals so that a direct comparison of details of the present invention with the prior art system of FIG. 4 may be made. For example, it can now be seen that a force F applied to adaptor A according to the invention will be directed along axis Y which is the axis of lens 20 rather than to one side thereof as in FIG. 4. Thus, the pressure is applied to the lens 20-tool 38 interface uniformly thereover as depicted by arrows 44 in the FIG. 5 embodiment of the invention. By such means problems of introducing errors of prism and/or unpolished "gray" areas during final surfacing of lens 20 are obviated.
Adaptor A comprises a first member 46 constructed and arranged to intimately fit over lens block 24 and become locked against rotational displacement thereon by keying to tab 48 also shown in FIG. 2. Surface 50 of member 46 is right-angularly knurled to provide a uniform pattern of upwardly directed projections 52 substantially as illustrated in FIG. 7 and against which a surface 54 of the second member 56 of adaptor A is positioned. In order to interlock members 46 and 56 at preselected relative positions of interfacial alignment which brings the center of component 56 coincident with axis Y, and at the same time prevent lateral slippage between members 46 and 56, knurling preferably in the pattern depicted in FIG. 6 is applied to surface 54. This knurling scheme provides for a section 58 which is knurled or ridged in one direction only and remaining sections 60 which are knurled or ridged in another right-angular direction. All knurling or ridging of surface 54 is of such shape and size as to accurately interfit with the right-angular knurling of surface 50 of component 46. As illustrated in the enlarged fragmentary cross-sectional view of FIG. 8, the knurled and/or ridged configuration of surfaces 50 and 54 provide for an interlocking interfacial engagement of components 46 and 56 at any and all preselected overlapping positions thereof. The fineness of knurling and/or ridging is determinative only of the minimum extent of incremental adjustment permitted in any one lateral direction to move one component relative to another from one interlocked position to a next interlocked position.
Referring more particularly to FIG. 8, it can be seen that if surface 54 of component 56 were right angularly knurled exactly as surface 50 of component 46, interfitting of the two surfaces would be possible but slippage in one or both of the right angular directions of knurling would not be prevented. In the present instance of special knurling or ridging used for surface 54, it can be seen from FIG. 8 that the knurling or ridging of sections 60 prevents slippage of one component 46 or 56 relative to the other in directions into and out of the sheet of drawings while knurling or ridging 58 similarly prevents slippage of the aforesaid components in directions left and right across the sheet of drawings.
Modifications of the surface treatment illustrated in FIGS. 5 - 8 are illustrated in FIGS. 9 and 10. In FIG. 9, surfaces 50' and 54' are respectively provided with recesses 62 and protrusions 64 which are so correspondingly geometrically patterned as to all simultaneously interfit when the two surfaces 50' and 54' are brought together at a point of adjustment of adaptor A'. By such means lateral slippage is again prevented once adaptor A' is set for use. In similar fashion, semicircular recesses 66 and protrusions 68 may be provided in place of any of the aforesaid schemes as shown in the drawing of adaptor A" (FIG. 10). It should be understood that conical, triangular, rectangular or other variously shaped matching recesses and protrusions may be employed at the discretion of the artisan.
With attention given once again to FIG. 5, it can be seen that the problems of prior art lens fine grinding and polishing which are exemplified in FIG. 4 are overcome by the present invention through provision for shifting the surfacing force from the usual center of a decentered block by an amount z sufficient to locate and direct the applied force F along axis Y of the lens so that even distribution of this force over the lens-tool surfacing interface is accomplished as represented by arrows 44.
Those skilled in the art will readily appreciate that there are various other forms and adaptations of the invention which may be made to suit particular requirements. Accordingly, the foregoing illustrations are not to be interpreted as restrictive of the invention beyond that necessitated by the following claims. | Ophthalmic lens surfacing with preformed tools (laps) requires the traditional blocking and pressing of a lens against the tool with force applied to the block. Lens blocks being thereby geometrically decentered in many of larger diameter lenses causing force applied to the block to be unevenly distributed over the lens-tool surfacing interface. This being detrimental to final lens surface shape and finish is avoided according to the present invention by the provision of a universally adjustable lens block adaptor designed to receive and distribute the surfacing pressure uniformly over the lens-tool interface. | 1 |
This is a divisional application of application Ser. No. 08/002,958 filed Jan. 11, 1993 now U.S. Pat. No. 5,375,535.
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to improvements in the operation and configuration of long rotary cement kilns. More particularly it is directed to a method and apparatus for enhancing the capacity and efficiency of cement clinker production in conventional wet or dry process long rotary kilns. A portion of the kiln gases is withdrawn from the rotary vessel at a point upstream, relative to kiln gas flow, of the mineral drying zone and pre-heating zone to form a kiln gas bypass stream.
In the widely used commercial process for the manufacture of cement, the steps of drying, calcining, and clinkering cement raw materials are accomplished by passing finely divided raw materials, including calcareous minerals, silica and alumina, through a heated, inclined rotary vessel or kiln. In what is known as conventional long dry or wet process kilns the entire mineral heating process is conducted in a heated rotating kiln cylinder, commonly referred to as a "rotary vessel." The rotary vessel is typically 12 to 15 feet in diameter and 400-700 feet in length and is inclined so that as the vessel is rotated, raw materials fed into the upper end of the kiln cylinder move under the influence of gravity toward the lower "fired" end where the final clinkering process takes place and where the product cement clinker is discharged for cooling and subsequent processing. Gas temperatures in the fired clinkering zone of the kiln range from about 1300° to about 1600° C. Kiln gas temperatures are as low as about 250° to 350° C. at the upper mineral receiving end of so-called wet process kilns. Somewhat higher gas temperatures exist in the upper end of long dry process kilns.
Generally, skilled practitioners consider the cement making process within the rotary kiln to occur in several stages as the raw material flows from the cooler gas exit mineral feed end to the fired/clinker exit lower end of the rotary kiln vessel. As the mineral material moves down the length of the kiln it is subjected to increasing kiln gas temperatures. Thus in the upper portion of the kiln cylinder where the kiln gas temperatures are the lowest, the in-process mineral materials first undergo a drying process and thereafter move into the hotter calcining zone and finally into the portion of the kiln where the kiln gas temperatures are the hottest, the clinkering zone adjacent to the fired lower end of the kiln cylinder. The kiln gas stream flows counter to the flow of in-process mineral materials from the clinkering zone, through the intermediate calcining zone and the mineral drying zone and out the upper gas exit end of the kiln into the kiln dust collection system. The flow of kiln gases through the kiln can be controlled to some extent by a draft induction fan positioned in the kiln gas exhaust stream.
The drying/pre-heat zone of a long process kiln is defined as that part of the kiln in which sufficient heat transfer takes place from the kiln gas stream to the mineral bed to eliminate moisture from the mineral raw material feed. In the drying zone, the mineral material is heated to a temperature of up to approximately 1500° F., the temperature at which mineral carbonates begin to calcine (release carbon dioxide). To facilitate the transfer of heat in the drying/pre-heat zone, chain curtains are provided. As mineral material is introduced and travels down the length of the drying zone, the chains continually rotate between the hot kiln gas phase and the mineral material phase transferring heat from the gases to the raw materials.
One of the shortcomings of the use of conventional long kilns for cement manufacture derives from the significant quantities of dust generated in the drying zone of the kiln and carried out of the kiln in the kiln gas stream. On the average about 7-10% (but as high as about 17%) of the raw material feed on a dry basis is blown back from the drying zone as dust. The high dust loss associated with the manufacture of cement clinker in long wet or dry process kilns places long kiln operators at a significant economic disadvantage relative to cement manufacturers using the newer pre-heater/pre-calciner kilns. High dust loss not only means loss of efficiency of use of raw materials--dust recovery is limited because of contamination by volatile alkali salts --but it also requires greater capital investment in dust collection equipment and loss of energy efficiency. Every ton of raw material lost as dust consumes significant amounts of heat energy during drying. Further the long kiln operator is burden by the cost of handling/disposal of waste dust.
Another disadvantage suffered by cement manufacture in conventional long kilns relative to that in pre-heater/pre-calciner kilns derives from the internal cycling of volatile alkali salts. As the in-process mineral travels down the kiln to the hotter zones, alkali salts such as potassium and sodium sulfates in the mineral are volatilized into the kiln gas stream and carried as an alkali fume into the coolest zones of the kiln, including particularly the dust generating drying zone where the alkali fume condenses on the dust and either falls back into the in-process mineral bed or is carried out of the kiln in the kiln gas stream and collected with the kiln dust in the dust collection system. It is the presence of the significant quantities of condensed alkali salts in the kiln dust that prohibits the return of the dust to the process--adding the alkaline dust to the mineral raw material can disrupt the alkali salt recirculation equilibrium and cause unacceptably high alkalinity in the cement product.
During cement kiln operation there is significant recirculation of alkali salts from the mineral bed to the kiln gas stream and back to the mineral bed. At equilibrium conditions where the alkali salts are carried out of the kiln at the same rate at which they are introduced in fuels and raw materials, it is estimated that there is 90% trapping of the volatilized alkali. The internal cycling of high quantities of alkali salts during kiln operation constitutes a significant energy burden on the process. Large quantities of high grade heat in the hotter zones of the kiln (where the heat is needed most) are lost to alkali volatilization only to be returned to the process as low grade heat during condensation in the lower temperature zones where excess heat is not needed. The configuration of pre-heater/pre-calciner kilns allows facile installation of alkali bypass conduits through which a portion of the alkali fume-laden kiln gas stream can be withdrawn before it becomes contaminated with entrained kiln dust, thereby not only reducing the alkali load in the internal cycle, but also providing means for recovery of a product highly enriched in the volatile alkaline salts. Until recently, there has been no means for establishing an alkali bypass for conventional long wet or dry process kilns.
There are many existing long kiln cement manufacturing operations, not only in the United States but in many other countries as well around the world. A method/apparatus for reducing dust loss and for enhancing control of the internal alkali cycling in long kiln cement manufacturing operations is disclosed in copending U.S. patent application Ser. No. 07/913,587 which is incorporated herein by reference. The invention disclosed in the '587 application enables long kiln operators to be more economically competitive with pre-heater/pre-calciner kiln operators.
The '587 application discloses modifying the kiln to allow withdrawal of a portion of the kiln gases from the rotary vessel at a point upstream, relative to kiln gas flow, of the mineral drying zone. By removing a portion of the kiln gas from the calcining zone, or more particularly from a point upstream, relative to kiln gas flow, of the mineral drying zone (most particularly the chain curtain section) and downstream of the hottest portions of the calcining zone, there is achieved a substantial reduction in dust generated and lost from the drying zone. Reduced dust loss derives not only from reduced kiln gas velocities in the drying zone, but also from the resultant extension of the drying zone itself. Removing a portion of the hot kiln gas stream results in an extended drying zone--the raw feed will have a greater moisture content through the chain curtain section of the kiln, effectively reducing the generation of dust in the drying zone.
Preferably the bypass is designed to withdraw at least about 10% of the hot kiln gases at a point upstream of the mineral drying/pre-heat zone. The bypass gases are cooled, for example, by mixing with ambient air and either returned to the kiln gas stream upstream of the kiln dust collection system, including for example, an electrostatic precipitator, or directed to an independent dust collection system.
A 10% reduction of kiln gas flowing through the drying zone is expected to result in an average velocity reduction in the drying zone of about 20% by the combined action of reduced mass and temperature. With that velocity reduction, the amount of dust blown by the gas stream out the upper gas exit end of the kiln will decrease significantly. The reduced dust loss allows an associated reduction in the amount of raw material for the same amount of clinker production. Of course, reduced dust loss also means less dust requiring disposal by the kiln operator and less of a dust load on the dust collection system.
A shortcoming associated with the bypass system disclosed in the '587 is that condensed alkali tends to build up inside bypass inlet tube as the kiln gas cools in the inlet tub. An air cannon is used periodically during kiln operation to clear condensed alkali from the port and the bypass inlet tube during kiln operation without perturbation of the on-going cement manufacturing process. An industrial 8-gauge shotgun utilizing No. 4 zinc shot can be substituted for air cannon or used in combination therewith to clear condensed alkali from port and bypass inlet tube.
An object of the present invention is to reduce or prevent buildup of condensed alkali inside a bypass inlet tube of a long kiln bypass system.
According to one aspect of the present invention, an improved design for bypass apparatus is provided for use with a long cement kiln. The long cement kiln comprises a cylindrical rotary vessel in which a kiln gas stream flows countercurrent to in-process mineral. The bypass apparatus comprises an annular bypass plenum, a port in the wall of the rotary vessel in gas flow communication with said plenum, means for preventing passage of in-process mineral through said port, and means for inducing flow of at least a portion of the kiln gas stream to form a bypass stream through said port and into the annular bypass plenum. The improvement of the present invention comprises means for mixing controlled amounts of ambient air with said bypass stream before it passes through said port in the wall of the rotary vessel.
The means for preventing passage of in-process mineral through the port includes a draft tube having a first end communicating with the port and a second end communicating with the kiln gas stream. The means for mixing ambient air with the bypass stream includes means for delivering ambient air to the second end of the draft tube. The ambient air delivery means includes an air conduit for directing ambient air to the second end of the draft tube and means for controlling ambient air flow through said conduit.
The air conduit is in gas flow communication with at least a portion of an annular space defined by the outer surface of the rotary vessel and a sealing sleeve mounted on the rotary vessel in axial alignment with the port. The portion of the annular space in gas flow communication with the air conduit is further in gas flow communication with a windbox comprising an annular plenum and the means for controlling air flow into the air conduit includes a variable speed fan in air flow communication with the annular plenum of the windbox.
In the illustrated embodiment, the air conduit for directing ambient air to the second end of the draft tube comprises an annular channel defined by the draft tube and a draft tube sleeve surrounding the draft tube. The draft tube sleeve extends into the rotary vessel beyond the second end of the draft tube. The draft tube sleeve includes a radially inwardly extending flange having an upturned lip for deflecting ambient air toward the second end of the draft tube.
According to another aspect of the present invention, a method is provided for enhancing the capacity and efficiency of clinker production of an operating conventional wet or dry long rotary kiln. The kiln comprises a rotary vessel having a fired lower end and an adjacent clinkering zone, an upper gas exit end and an adjacent mineral drying zone, and an intermediate calcining zone along its length and a kiln gas stream flowing from the clinkering zone through the intermediate calcining zone and mineral drying zone out the gas exit end to a kiln dust collection system. The method comprises the steps of withdrawing a portion of the kiln gases through a port formed in a wall of the rotary vessel at a point upstream, relative to kiln gas flow, of the mineral drying zone to form a kiln gas bypass stream, and mixing controlled amounts of ambient air with said kiln gas bypass stream to cool the kiln gas bypass stream and to precipitate alkali fume in the bypass stream before it passes through the port in the wall of the rotary vessel.
The method further includes the step of further cooling or quenching the gas bypass stream after the gas bypass stream passes through the port in the wall of the rotary vessel to cool said gas bypass stream to a predetermined operating temperature. The bypass stream is preferably further cooled (quenched) by its mixture with ambient air optionally in combination with a water spray after the kiln gas bypass stream passes through the port in the wall of the rotary vessel. The illustrated method further includes the steps of collecting at least a portion of precipitated alkali fume from the cooled gas bypass stream and recombining the quenched kiln gas bypass stream with the kiln gases upstream, relative to kiln gas flow, of the kiln dust collection system.
According to yet another aspect of the present invention, an apparatus is provided for enhancing the capacity and efficiency of clinker production of a conventional wet or dry long rotary kiln. The kiln comprises a rotating vessel having a fired lower end and an adjacent clinkering zone, an upper kiln gas exit end and an adjacent mineral drying zone, and an intermediate calcining zone along its length and a kiln gas stream flowing from the clinkering zone through the intermediate calcining zone and upper mineral drying zone to a kiln dust collection system. The apparatus includes a port formed in the rotary vessel at a point upstream, relative to kiln gas flow, of the mineral drying zone. The apparatus also includes a draft tube for preventing passage of in-process mineral through the port. The draft tube has a first end communicating with the port and a second end communicating with the kiln gas stream. The apparatus further includes an annular plenum in alignment with the port axially along the length of the rotary vessel, in gas flow communication with said port and having located thereon an air inlet damper valve. The apparatus still further includes means for creating reduced pressure in said annular plenum to draw air into said air inlet and to withdraw at least a portion of the kiln gas stream through the draft tube to form a kiln gas bypass stream which passes into said annular plenum. In addition, the apparatus includes means for mixing controlled amounts of ambient air with said the kiln gas bypass stream before it enters the second end of the draft tube to cool the kiln gas bypass stream and to precipitate alkali fume in the kiln gas bypass stream before it enters the second end of the draft tube to reduce build up of condensed alkali inside the draft tube.
According to a further aspect of the invention, an apparatus is provided for enhancing the capacity and efficiency of clinker production of a conventional wet or dry long rotary kiln. The kiln in operation comprises a rotary vessel having a fired lower end and an adjacent clinkering zone, an upper kiln gas exit end and an adjacent mineral drying zone, and an intermediate mineral calcining zone along its length and a kiln gas stream flowing from the clinkering zone through the intermediate calcining zone and upper mineral drying zone to a kiln dust collection system. The apparatus includes a solid fuel charging port and a gas bypass port formed in the rotary vessel. The fuel charging port is located at a point along the length of the vessel wherein fuel charged through the port will enter the calcining zone. The bypass port is located at a point on the vessel downstream, relative to kiln gas flow, from said fuel charging port. The apparatus also includes means for preventing in-process mineral from passing through each of said fuel charging and bypass ports, and an annular plenum in alignment with the bypass port axially along the length of the rotary vessel and in gas flow communication with said bypass port. The apparatus further includes means for creating reduced pressure in said annular plenum to withdraw at least a portion of the kiln gas stream through the bypass port and into said annular plenum to form a kiln gas bypass stream, and means cooperating with the charging port for charging solid fuel into the calcining zone. The apparatus still further includes means for mixing controlled amounts of ambient air with said bypass stream to quench the kiln gas stream to precipitate alkali fume in the bypass stream before it passes through the bypass port in the wall of the rotary vessel.
According to a still further aspect of the invention, an apparatus is provided for enhancing the capacity and efficiency of clinker production of a conventional wet or dry long rotary kiln. The kiln comprises a rotating vessel having a fired lower end and an adjacent clinkering zone, an upper kiln gas exit end and an adjacent mineral drying zone, and an intermediate calcining zone along its length and a kiln gas stream flowing from the clinkering zone through the intermediate calcining zone and upper mineral drying zone to a kiln dust collection system. The apparatus of the present invention includes a port formed in a wall of the rotary vessel. The port is located axially between the calcining zone and the mineral drying zone. The apparatus also includes a sealing sleeve mounted on the rotary vessel in axial alignment with the port. The sealing sleeve defines an annular space between an outer surface of the rotary vessel and the sealing sleeve. The sealing sleeve is formed to include an aperture therein. A draft tube has a first end which is coupled to the aperture formed in the sealing sleeve. The draft tube extends through the port and into the rotary vessel a predetermined distance which is longer than the maximum depth of in-process mineral in the rotary vessel. The draft tube has a second end in communication with the kiln gas stream. A first annular plenum is located in axial alignment with the port and the aperture in the sealing sleeve. The first annular plenum is in gas flow communication with the port and the aperture in the sealing sleeve. A blower fan is coupled to the first annular plenum for creating reduced pressure in the first annular plenum to withdraw at least a portion of the kiln gas stream through the draft tube and into the first annular plenum to form a kiln gas bypass stream. The apparatus further includes a draft tube sleeve having a first end coupled to the port in the rotary vessel. The draft tube sleeve extends into the rotary vessel and surrounds the draft tube to define an annular channel therebetween for directing ambient air to the second end of the draft tube. The apparatus still further includes a windbox having a second annular plenum in gas flow communication with the annular space between the outer surface of the rotary vessel and the sealing sleeve. In addition, the apparatus includes means for controlling ambient air flow through the second annular plenum, through the annular space between the outer surface of the rotary vessel, and through the annular channel between the draft tube sleeve and the draft tube to mix controlled amounts of ambient air with said kiln gas bypass stream before it enters the second end of the draft tube to cool the kiln gas bypass stream and to precipitate alkali fume in the kiln gas bypass stream before it enters the draft tube to reduce build up of condensed alkali inside the draft tube.
Use of the present bypass apparatus of the present invention in long kilns provides multiple advantages to the cement manufacturing process. The operation of the present bypass system will allow the drying zone of the kiln to operate somewhat independently of the rest of the process. The energy demands of the calcining process are such that more than sufficient energy remains at the process boundary between the calcining and drying/pre-heating zones to accomplish the drying/pre-heating step. By rerouting a portion of the kiln gas around the drying/pre-heating zone through the bypass duct, the amount of energy supplied to the drying/pre-heating zone will more closely match the process requirements of this zone. Consequently, the volume of gases passing through this zone will be reduced, thereby resulting in lower gas velocity. The lower velocity will in turn reduce the amount of in-process material that will be entrained in the kiln gas stream and exit the kiln as cement kiln dust. The reduced velocity of the gas stream in the drying zone during operation of the bypass system results in a 40-72% reduction of kiln dust lost from the kiln, thereby resulting in increased process economy.
Pieces of chain are suspended in the drying/pre-heating zone as an internal heat exchange device. The suspended chains also trap some of the volatile salts (e.g., K 2 SO 4 ) in the process until equilibrium is reached and an internal cycle of volatile constituents is established in which these constituents leave the process at the same rate at which they are introduced in fuels and raw materials. An internal cycle of alkali salts can cause operating problems such as the buildup of material rings in the kiln. By rerouting a portion of the hot kiln gas containing the gaseous volatile constituents around the chain system, the magnitude of the internal cycle will be reduced, thus improving kiln operation. During operation of the bypass, "bypass gas" will be extracted prior to the gas entering the turbulence of the chain system. As a result, it is expected that there will be little suspended particulate matter in this bypass gas; however, the hot bypass gas will contain the alkali fume and other volatilized components--one target of the bypass arrangement. When the bypass gas stream is recombined with the exit gas from the drying/pre-heating zone of the kiln prior to its entry into the air pollution control (dust collection) system, the thermal energy in the bypass gas ensures that the temperature of the gas is above the dew point even if the kiln exit gas itself is at or below the dew point.
Under 40 C.F.R. 266.104(g), monitoring of CO and THC in a bypass duct is allowed as a means of complying with CO and THC limits, provided that: (1) hazardous waste is fired only into the kiln and not at any location downstream from the kiln exit relative to the direction of gas flow (i.e., downstream from the bypass); and (2) the bypass diverts a minimum of 10% of the kiln off-gas into the duct. The preamble to the BIF regulation (56 F.R. 7159, Feb. 21, 1991) acknowledges that a rationale for allowing monitoring in a bypass duct is that a bypass would preclude the interference of non-fuel THC emissions from raw materials. In long kilns, the raw material is heated in the drying/pre-heating zone to a temperature sufficient to evaporate the hydrocarbons contained therein. The hydrocarbons from that heating process are contained in the kiln exit gases. The bypass duct will draw gas from the kiln prior to its entry into the drying/pre-heating zone; therefore, gases will not have been affected by the raw material heating process. Thus, the monitoring of the bypass gases is a true representation of the gases from the combustion process without interference from hydrocarbons in the raw material.
The present invention also enables enhanced clinker production capacity in long kilns. There are two limiting factors in the production of cement in long wet process kilns: (1) the kiln gas velocity in the drying zone causing dust loss; and (2) thermal loading in the sintering zone. Inherently these factors work to limit the amount of heat energy that can be delivered into the kiln for transfer for the in-process mineral. The impact of the first of those limiting factors can be minimized by use of the present bypass apparatus. Subject to the limitations imposed by factor (2) above, the bypass apparatus can be used to reduce kiln gas stream velocities in the drying zone even with significantly higher energy input into the process.
It has recently been reported in the art that conventional long kilns can be modified to provide an environmentally safe and economically advantageous use of solid waste fuels. Apparatus and methods for delivering solid fuels, especially solid waste fuels, are known in the art. See, for example, U.S. Pat. Nos. 4,930,965, 4,969,407, 4,850,290, 5,078,594 and 5,083,516. The delivery of solid fuel into the calcining zone in accordance with the teachings of those patents tends to increase the temperature of the kiln gas stream, and concomitantly kiln gas stream velocity, through the drying zone with potential enhanced dust loss. The present long kiln bypass method and apparatus can be utilized in conjunction with use of the art-recognized methods and apparatus for burning combustible solids, particularly combustible waste solids, as supplemental fuel in long kilns.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiments exemplifying the best mode of carrying out the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of an improved long rotary kiln in accordance with the present invention showing mineral flow in a downhill direction through the drying, calcining and clinkering zones in a rotary vessel, hot kiln gas flow in an uphill direction in the rotary vessel, a kiln gas bypass for withdrawing a portion of the hot kiln gases through a draft tube to produce a kiln gas bypass stream, and a windbox located adjacent the kiln gas bypass for supplying primary quench air to a primary quench tube to a draft tube sleeve to quench the hot kiln gas bypass stream before it passes through the draft tube.
FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1 illustrating a preferred embodiment of a venting apparatus component of this invention with portions broken away.
FIG. 3 is a sectional view taken along lines 3--3 of FIG. 2 illustrating the interface of an annular bypass plenum and the windbox with the rotary kiln vessel.
FIG. 4 is a sectional view taken along lines 4--4 of FIG. 3 illustrating the configuration of the draft tube located within the draft tube sleeve.
FIG. 5 is a top elevational view of a portion of the rotary kiln vessel illustrating air flow between the windbox and the primary quench tube.
DETAILED DESCRIPTION OF THE INVENTION
An improved long rotary kiln 10 for converting mineral materials 12 into cement clinker 14 is illustrated in FIG. 1. The kiln 10 includes an inclined rotary vessel 16 and means (not shown) for rotating the rotary vessel 16 about its longitudinal axis. Mineral materials 12 from mineral supply 18 are charged into mineral inlet 20 at upper end 22 of the rotary vessel 16. As rotary vessel 16 is rotated, mineral materials 12 move under the influence of gravity through a mineral drying/pre-heat zone 24, a calcining zone 26 and a clinkering zone 28 before being discharged as cement clinker 14 from lower end 30 of rotary vessel 16 into cooling chamber 32.
Fuel from fuel supply 34 is combined with combustion air 36 pre-heated as it is drawn through cooling chamber 32 and burned using burner 33 in the clinkering zone 28 of rotary vessel 16. A chain system or the like (not shown) is used to improve the efficiency of heat transfer from the hot kiln gases flowing through the mineral drying/pre-heat zone 24 to the mineral materials 12. The chains are exposed to the hot kiln gases and deliver heat to the mineral bed 12 during rotation of rotary vessel 16. The hot kiln gas stream illustrated by arrows 38 and 40 generated by fuel combustion at burner 33 in clinkering zone 28 flows toward upper end 22 of rotary vessel 16 under influence of negative pressure created by fan 41. The kiln gas stream 40, after exiting upper end 22 of rotary vessel 16 is directed to kiln dust collection system 46 including an electrostatic precipitator or other suitable gas cleaning system to separate kiln dust into dust storage 52 and an environmentally acceptable air stream delivered into the atmosphere through stack 50.
The configuration of the elements of the mineral feed components and the kiln gas processing components at the upper end 22 of rotary vessel 16 are well known those skilled in the art and it should be appreciated that such elements are shown diagrammatically in FIG. 1 to illustrate their relationship and cooperation in operation of rotary kiln 10. It will be understood that any of a wide variety of mineral loading and kiln gas handling systems may be incorporated into the kilns modified in accordance with the present invention.
Further with reference to FIG. 1, a kiln gas bypass system 54 is provided for withdrawing a portion of the kiln gas stream from rotary vessel 16 during kiln operation to produce a kiln gas bypass stream 64 which is delivered through bypass conduit 62 to the kiln gas stream in kiln gas exhaust conduit 42 after the gas stream exits the upper end 22 of rotary vessel 16. Bypass system 54 includes a venting apparatus 56 in gas flow communication with the kiln gas stream 38 in rotary vessel 16 and with bypass conduit 62. Venting apparatus 56 is located at a point along the axial length of rotary vessel 16 upstream, relative to kiln gas flow, of the mineral drying/pre-heat zone 24. It can be located a point in alignment with the calcining zone 26 or more preferably at a point corresponding to the downstream (relative to kiln gas flow) end portion of the calcining zone 26. The venting apparatus 56 can be located on the rotary vessel 16 at a point intermediate between the chain system (not shown) in mineral drying zone 24 and a downstream portion of the calcining zone 26. The preferred location of the venting apparatus can be stated alternatively as between the chain system (not shown) in the mineral drying zone 24 and the middle of rotary vessel 16--functionally between the chain system of the mineral drying zone 24 and the hottest portions of the calcining zone 26. Most preferably, the venting apparatus 56 is located at a point on the rotary vessel that is about one kiln diameter upstream relative to kiln gas flow, of the chain system in the mineral drying zone 24.
In operation kiln bypass system 54 is utilized to withdraw a portion of the kiln gas stream from rotary vessel 16 to reduce the velocity (and mass) of kiln gases flowing through the mineral drying zone 24 thereby reducing the amount of dust that is discharged from upper end 22 of rotary vessel 16 during kiln operation. The bypass gas stream 64 is returned to the kiln gas stream at a point downstream of the mineral drying zone 24 and upstream of the kiln dust collection system 46. The resultant reduced kiln gas velocities in mineral drying zone 24 effects a significant reduction in dust lost during cement manufacture. The reduced dust loss enhances the efficiency of cement clinker production not only by decreasing the raw material/clinker production ratio but concomitantly allows for enhanced energy/fuel efficiency.
Bypass system 54 also includes a windbox 58 located adjacent venting apparatus 56. As discussed below in detail windbox 58 delivers a supply of primary quench air to venting apparatus 56 to quench the kiln gas stream before the kiln gas stream is withdrawn from rotary vessel 16. Ambient air is supplied to windbox 58 by fan 59 through conduit 60 coupled to windbox 58.
The formation of a bypass stream from an operating long wet or dry process rotary kiln in accordance with the present invention offers multiple advantages to the cement making process. Firstly, as mentioned above, formation of the bypass stream reduces the mass/velocity of kiln gases traversing the mineral drying zone 24. That works in at least two ways to reduce dust lost. It reduces the amount of energy delivered to the drying zone thereby extending the drying zone in the chain system--the more moisture retained by the mineral in the chain system, the less the tendency of the drying mineral to produce dust. Further, and perhaps more directly, the formation of a bypass stream upstream of the drying zone 24 reduces the velocity of the kiln gas stream flowing through the drying zone and concomitantly reduces its ability to carry dust out the upper gas exit end of the operating kiln.
Further, the formation of a bypass stream can be used to regulate the temperature of kiln gas stream exiting the upper end 22 of the rotary vessel. The bypass system of the present invention can also be used to remove alkali from the cement making process. Alkali components are volatilized in the calcining and clinkering zones of the kiln. Without use of the bypass system alkali components volatilized into the kiln gas stream condense on the dust particles in the kiln drying zone and either fall back into the mineral bed or contaminate the kiln dust blown out of the kiln by the kiln gas stream to the extent that it cannot be added back to supplement the mineral material for the cement making process. The bypass system allows the kiln operator not only to reduce dust lost, but as well, to reduce the alkali content of the dust that exits the back of the kiln that is produced during use of the bypass system. Further, the bypass stream can be processed to remove at least a portion of the alkali fume before it is returned to the kiln gas stream upstream of the kiln dust collection system. The high alkali dust isolated from the quenched bypass stream can be collected and used as a source of alkali (potassium, sodium and other volatile metal salts).
FIGS. 2 and 3 illustrate a preferred bypass system 54 in accordance with this invention located on a rotary vessel 16 to enable formation of a kiln bypass stream by withdrawal of a portion of the kiln gas stream at a point upstream of the mineral drying zone during kiln operation. Venting apparatus 56 is located axially on rotary vessel 16 to enable withdrawal of about 10% to about 35% of the kiln gas stream at a point upstream of the mineral drying zone during kiln operation. Venting apparatus 56 includes a refractory-lined plenum 66 in gas flow communication with the inside of rotary vessel 16 (having refractory liner 17) through bypass inlet tube assembly 68 and bypass port 70 (FIG. 6) in rotary vessel 16. Annular plenum 66 is extended in its lower portion to form a dust collection funnel 72 for directing kiln dust into conduit 74 through double tipping valve (not shown) and flexible boot (not shown) into a dust collector 65 illustrated diagrammatically in FIG. 1. Annular plenum 66 is provided with a sealable service hatch 76 to permit access to bypass port 70 and bypass inlet tube assembly 68 for cleaning or repair. Bypass inlet tube assembly 68 extends into rotary cylinder 16 from port 70 to prevent loss of mineral material 12 through port 70. The length of the bypass inlet tube assembly 68 is preferably selected to be the minimum length necessary to assure that the tube penetrates the load to prevent escape of in-process mineral through the port 70 during kiln rotation.
Annular plenum 66 is provided with bypass gas exit 78 having plenum isolation damper 80 for controlling gas flow communication between plenum 66 and bypass conduit 62. Plenum 66 is lined with refractory 82 and formed to include air damper valve 84 to allow secondary kiln-gas-quenching air to enter plenum 66 through conduit 85 in the direction of arrow 86. Air damper valve 86 is located on plenum 66 diametrically opposed to bypass gas exit 78 to optimize quenching of kiln gases exiting vessel 16 into annular plenum 66. A kiln gas bypass stream is formed by withdrawing at least a portion of the kiln gas stream in rotary vessel 16 through bypass inlet tube assembly 68 and port 70 and into the annular plenum 66 under the influence of a negative pressure (relative to that in rotary vessel 16) induced by bypass fan 41. Hot bypass stream 64 mixes with ambient air inside interior region 67 of annular plenum 66. Ambient air is drawn through air damper valve 84 under the influence of negative pressure from bypass fan 41. Valve 84 is operated manually or automatically to control ambient air flowing into air conduit 85 in the direction of arrow 86. Therefore, a secondary quench of the kiln bypass stream is provided through conduit 85 in communication with interior region 67 of annular plenum 66. The secondary quench further reduces the temperature of the bypass stream to a predetermined operating temperature.
Conduit 85 and damper valve 84 are preferably sized so that the ratio of the volume of ambient air flowing through conduit 85 to the volume of gas bypass stream is about 1:1 to about 5:1, the lower ratios (and thus higher bypass gas temperatures) being preferred to keep the volume of the bypass stream to a minimum. Air damper valve 84 and bypass fan 41 can be controlled to adjust the ratio of ambient air to the bypass gas stream.
The ambient air-quenched gas bypass stream can be processed to remove at least a portion of the alkali fume precipitated from the bypass stream before the bypass stream is returned to the kiln gas stream. The extent of quenching is dictated principally by the operating temperature limits of the materials used for construction of the bypass system and the need to control the condensation of the volatile alkali components of the bypass stream. If a bypass fan is required (it is optional where fan 41 is capable of inducing sufficient bypass flow through the venting apparatus and bypass conduits), the bypass temperature is usually limited by the operating temperature limits for the fan. Typically, industrial fans specified for this type of operation have a maximum operating temperature of about 800° F., but fans having a higher maximum operating temperature are available at much greater capital cost. Typically there will be a certain amount of air in leakage (and quenching) in the annular plenum due to the inherent air leakage characteristic of the seal between the plenum and the rotary vessel.
Air infiltration at the interface of the annular plenum 66 and windbox 59 with rotating vessel 16 is controlled by use of a sealing system 88 best shown in FIG. 3. Sealing system 88 includes a sealing sleeve 90 supported by spacers 92 on the surface 93 of rotary vessel 16 to define an open annular air space 94 which allows radiant and convective cooling of the axial portion of the surface 93 of rotary vessel 16. Sealing system 88 further comprises leaf seals 96 which are mounted on opposite lateral edges 97 and 98 of annular plenum 66 and on opposite lateral edges 99 and 100 of windbox 59 in wiping/sealing contact with sealing sleeve 90. Leaf seals 96 can be formed of one or more overlapping layers of stainless steel or mild steel leaves.
A shortcoming associated with the bypass system disclosed in copending U.S. patent application Ser. No. 07/913,587 which is incorporated herein by reference is that condensed alkali tends to build up inside bypass inlet tube as the kiln gas cools in the inlet tube. In the bypass system disclosed in the '587 application, an air cannon is used periodically during kiln operation to clear condensed alkali from the port and the bypass inlet tube during kiln operation without perturbation of the on-going cement manufacturing process. An industrial 8-gauge shotgun utilizing No. 4 zinc shot can be substituted for air cannon or used in combination therewith to clear condensed alkali from port 93 and bypass inlet tube 94. The present invention advantageously reduces buildup inside the inlet tube and therefore eliminates the need for an air cannon.
Operation of bypass system 54 is best illustrated in FIGS. 2-5. With reference to FIG. 3, bypass inlet tube assembly 68 includes a draft tube 102 and a draft tube sleeve or primary air quench tube 104 which surrounds draft tube 102. Draft tube 102 includes a first end 106 coupled to an aperture 108 formed in sealing sleeve 90. Therefore, the open first end 106 of draft tube 104 is in communication with interior region 67 of annular plenum 66. A second end 110 of draft tube 102 extends into the rotary vessel 16 and is in communication with kiln gas flowing through rotary vessel 16 in the direction of arrow 38. A first end 112 of primary air quench tube 104 is coupled to aperture 70 formed in outer wall of rotary vessel 16. A second end 114 of primary air quench tube 104 extends below second end 110 of draft tube 102. Second end 114 of primary air quench tube 104 includes a radially inwardly extending flange 116. Flange 116 has an upturned lip 118 which deflects air toward open second end 110 of draft tube 102 as explained below. As illustrated in FIG. 4, a plurality of ribs 119 are coupled between draft tube 102 and primary air quench tube 104 to provide support therebetween. An annular air flow channel 121 is defined between draft tube 102 and primary air quench tube 104.
As rotary vessel 16 rotates, annular plenum 66 and windbox 58 remain stationary. Leaf seals 96 engage sealing sleeve 90 to prevent air from passing from annular plenum 66 and windbox 59 to the atmosphere. As best illustrated in FIGS. 2 and 3, air flow between windbox 59 and annular plenum 66 is blocked throughout most of the circumference of rotary vessel 16. A barrier 120 best illustrated in FIG. 2 blocks air flow between windbox 58 and annular plenum 66. Barrier 120 extends substantially around the entire circumference of rotary vessel 16. However, a portion of open annular air space 94 adjacent bypass inlet tube assembly 68 is not blocked by barrier 120 to permit air flow between windbox 58 and annular channel 121 of draft tube assembly 68 through an air flow channel 122.
FIG. 5 illustrates air flow channel 122 surrounding bypass inlet tube assembly 68. A barrier 124 is provided to block air flow beyond barrier 124 inside air flow channel 122. Air flow channel 122 is therefore defined between barrier 124 and supports 126 and 128. Center supports 123, 125 and 127 are spaced apart from barrier 124 to permit air flow between supports 126 and 128 in the area adjacent draft tube assembly 68.
In operation, the primary quench air is supplied to interior region 130 of windbox 58 through conduit 60 by fan 59. Illustratively, fan 59 is driven by a motor having a variable frequency drive. Primary quench air enters interior region 120 of windbox 58 in the direction of arrows 132. Primary quench air is blocked by barrier 120 throughout most of the circumference of rotary vessel 16. However, primary quench air flows through annular channel 122 in the direction of arrows 134. Barrier 124 blocks air flow within air flow channel 122 as discussed above. Primary quench air then flows through annular channel 121 defined between draft tube 102 and primary air quench tube 104 toward the second ends 110 and 114 of draft tube 102 and primary air quench tube 104, respectively. Kiln gas is drawn through open end 114 of primary air quench tube 104 and through open end 110 of draft tube 102 in the direction of arrows 136 to form a kiln gas bypass stream. Primary quench air is deflected toward open end 110 of draft tube 12 by upturned lip 118 of flange 116. Therefore, the primary quench air mixes with the kiln gas bypass stream as the bypass stream is drawn into open end 110 of draft tube. 102. Kiln gases are drawn into open end 110 of draft tube 102 by negative pressure in interior region 67 of annular plenum 66 caused by fan 41.
In the previous bypass system disclosed in the '587 application, volatile constituents present in the kiln gas stream condense upon the interior side wall of the draft tube. It is known that this solid material will continue to grow within the inside dimension of the draft tube until the tube is completely closed such that a condition of zero flow through the tube is achieved.
Once kiln gases are cooled below a predetermined temperature, the liquid phase of the volatiles solidifies. Because bypass system 54 of the present invention mixes controlled amounts of ambient air with the kiln gas bypass stream before it enters draft tube 102, an initial quench of the kiln gas bypass stream is provided to form a mobile dispersion of precipitated alkali in the bypass stream. Therefore, the volatile constituents do not stick to the interior side wall of draft tube 102. The present invention cools the kiln gases prior to withdrawing the kiln gases through draft tube 102 to substantially reduce buildup of solids in the draft tube. Ambient air introduced into windbox 58 is substantially cooler than the kiln gases flowing through rotary vessel 16. The primary quench air is directed through air flow channel 22 and through annular channel 121 defined between draft tube 102 and primary air quench tube 104. The primary air is introduced to the draft tube 102 concurrent with the entrance of hot kiln gases so that a primary quench of hot kiln gases is achieved at the point of entry of draft tube 102. Preferably the bypass gas should be quenched in the annular plenum to a temperature of less than about 950° F. to minimize build up of condensed alkali salts.
Travel of primary quench air through annular channel 121 also provides cooling air contact with an outer surface of a side wall of draft tube 102 and with the inner surface of a side wall of quench tube 104. This increases the life cycle of draft tube 102 and quench tube 104.
As shown diagrammatically in FIG. 1, in one preferred embodiment of the present invention, a solid fuel charging apparatus 140 is provided for charging solid fuel or the like into the calcining zone 26 or in downstream portions of the clinkering zone 28 through port 142 in the rotary vessel 16. Methods and apparatus for modification of long kilns for burning solid fuels, preferably solid waste derived fuel as supplemental fuel in operating cement kilns is described in U.S. Pat. Nos. 4,930,965, issued Jun. 5, 1990; 5,078,594, issued Jan. 7, 1992; and 5,083,516, issued Jan. 28, 1992, which patents are expressly incorporated herein by reference. Use of the bypass for long kilns in accordance with the present invention can be used in combination with the methods and apparatus described and claimed in those patents to provide optimum control and efficiency of cement manufacture in long wet or dry process kilns. Indeed, it is anticipated that use of the presently described bypass technology in conjunction with the recently developed technology for burning solid waste derived combustibles as supplemental fuel for long kilns will not only allow long kiln operators to extend the operating life of their long kilns but as well enable them to continue to compete favorably in the market place with cement manufacturers using more fuel efficient pre-heater/pre-calcining facilities.
Construction of the bypass and its associated components, including particularly bypass inlet tube 102, annular plenum 66, and primary quench tube 104 should be of materials which will withstand the thermally harsh conditions inherent in operation of the bypass. The temperature of the kiln gas adjacent inlet tube assembly 68 can be as high as 1800° F. Thus, bypass inlet tube 102 and primary quench tube 104 are typically constructed using high temperature resistant alloy materials. Plenum 66 is constructed of hot rolled steel and lined with castable refractory. Leaf seals 96 on annular plenum 66 and windbox 58 should be capable of maintaining sealing engagement with the annular sealing sleeve 90 mounted on rotary vessel 16 during kiln operation. Seals 96 can be constructed, for example, of graphite, capable of maintaining sealing engagement with the annular sealing sleeve 90 during rotation of rotary vessel 16.
Use of the venting apparatus of the present invention to enable enhanced control of the kiln gas stream in long wet or dry process cement kilns offers many advantages to the kiln operator, not only in terms of reduced dust loss and alkali volatiles management, but as well in the profound benefits of the enhanced clinker production capacity and enhanced energy and raw material utilization efficiency. There is a significant economic incentive for long kiln modification in accordance this invention. Yet as illustrated hereinabove and in copending U.S. application Ser. No. 07/913,587 which has been incorporated by reference, there are multiple variations in the use and processing of the bypass stream itself--even without regard to the alternatives for additional enhanced efficiencies through utilization of mid-kiln firing and tertiary air injection. It is understood that the improved bypass design of the present invention may be used with other bypass arrangements illustrated in the '587 patent application or elsewhere.
Although the invention has been described and defined in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and claimed in the following claims. | A bypass system is provided for a long cement kiln. The long cement kiln includes a cylindrical rotary vessel in which a kiln gas stream flows countercurrent to in-process mineral. The bypass system includes an annular bypass plenum, a port in the wall of the rotary vessel in gas flow communication with said plenum, and a draft tube for preventing passage of in-process mineral through said port. A blower fan induces flow of at least a portion of the kiln gas stream to form a bypass stream through the draft tube and the port and into the annular bypass plenum. The bypass system also includes an apparatus for mixing controlled amounts of ambient air with the bypass stream to cool the kiln gas bypass stream and to precipitate alkali fume in the kiln gas bypass stream before it passes through the draft tube and the port in the wall of the rotary vessel to reduce build up of condensed alkali inside the draft tube. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is the national phase of DE 10 2014 007 786.1, filed May 23, 2014, the content of which is incorporated herein in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a method for controlling the temperature of the calibration volume of a device for comparative calibrating of temperature sensors to a target temperature, wherein said calibrating apparatus comprises heat sources and/or heat sinks which are in thermal contact with the calibration volume through one or more heat conducting parts, as well as a device for regulating the temperature of a calibration volume of a device for comparative calibrating of temperature sensors to a target temperature, wherein the device consists at least of an electronic data processing unit that through an interface can receive measurement data of at least one temperature sensor located in the calibration device.
BACKGROUND OF THE INVENTION
[0003] The predominant number of temperature sensors used in industry and research are secondary thermometers. This means that the corresponding sensors, such as e.g. resistance thermometers or thermocouples must be repeatedly calibrated at least prior to their first use and usually also in the course of their regular use. For this purpose the temperature-sensitive sensors or temperature-stabilized switches to be calibrated are compared in furnaces or baths with a standard thermometer. Devices that temper a corresponding calibration volume to a predetermined constant target temperature are known. These so-called temperature calibrators can be designed as heavy immobile devices or, as they are described in the document U.S. Pat. No. 3,939,687 A, as compact portable calibrators.
[0004] In order to ensure optimum thermal coupling of the samples to the calibration or test volume, various insert sleeves or sockets that are adapted to the sensors to be tested can be introduced as solid bodies into the calibration volume of the temperature calibrator. For the calibration of sensors with complicated geometries, the calibration volume can be filled with liquid, gaseous or granular calibration media. In order to achieve spatial temperature distribution as constant as possible within the calibration volume, the calibration medium should have the highest possible thermal conductivity. To guarantee a very constant temperature curve, i.e., a high temperature stability, the calibration medium should have the highest possible thermal capacity. Since the calibration volume is to be tempered to the target temperature set by the user, heat can be removed from or added to the calibration volume through a thermally conductive body surrounding the volume. This body is typically designed in immobile calibrators as a tank and in portable calibrators typically as a metallic block and is in thermal contact with heat sinks, such as Peltier elements operated as cooling elements as described in DE 2005 006 710 U1, or the colder ambient air and heat sources, such as a resistance heating or warmer ambient air.
[0005] This leads to the question with which intensity or power the adjustable cooling and heating elements (control and manipulated variables) must be operated so that the temperature of the calibration volume (process variable) reaches the desired temperature value (setpoint) as quickly as possible and also holds it as stable as possible even with temporal changes such as the ambient air (disturbance parameter). The regulation technology problem of setting the control variables as a function of the temperatures measured in the calibration volume or in the heat conduction member (measurands) is solved by the present invention.
[0006] A well-known approach for controlling heating and cooling systems is the use of one or more associated PID controllers, as described in DE 2023130 B. A general disadvantage of the use of PID controllers is that, at least to achieve optimal control performance, i.e. a high stability of the temperature of the calibration volume, a very fine adjustment or complicated determination of the control parameters is necessary.
[0007] Another drawback in the case of the control of a temperature calibrator is that the optimal control parameters are dependent on environmental conditions, such as the ambient temperature, humidity or power supply. However, the main difficulty in the control of temperature calibrators is the large inertia of the controlled system, which extends from the heat sources and heat sinks over the heat conduction part to the calibration volume. Thus, even with relatively slow variations due to the high heat capacity of the heat conduction part, which may be designed as a metal block, and the calibration volume, which can be designed as a metallic insert bushing, the heating power with a frequency of less than 0.1 Hz, a phase lag of the temperature of the calibration volume for the heating capacity of nearly 3π can be observed. Accordingly, a stable control that responds to changes in environmental conditions within about seconds is not possible by means of one or several PID controllers or only after an extensive determination of appropriate control parameters. This has the consequence that the achievable temperature stability for target temperatures above 500° C. with the temperature calibrators available on the market at the time is about ±30 mK, and thus almost an order of magnitude worse than that necessary for high-precision temperature calibrations stability of ±5 mK.
[0008] One way to achieve both a high level of temperature homogeneity and a temporal temperature stability is the integration of one or more fixed-point cells in the block of a temperature calibrator as described in the document WO 2013/113683 A2. A disadvantage of the solution is that the constancy of the temperature of the fixed-point cell over the period of the phase transformation is given only for a phase transition temperature of the fixed-point cell used. At the same time the fixed-point cells are expensive so that a device for calibration at different temperature points stabilized by corresponding fixed-point cells would be associated with very high costs.
[0009] The dynamic calibration procedure described in document KR 100991021 B1 operates without costly temperature control. Instead, the temperature in the calibration volume near the calibration temperature to be observed is intentionally lowered or increased, and the resulting temperature offset between the normal thermometer and the samples is compensated by a time offset calculation. A disadvantage of this calibration is that the additional uncertainty resulting from the compensation is of the order of ±20 to ±40 mK and thus is significantly larger than the desired ±5 mK. A further disadvantage of the dynamic calibration is that the calibration is not performed at a temperature point, but rather within a temperature interval whose extent cannot be neglected and its location relative to the calibration point under consideration is not defined.
SUMMARY OF THE INVENTION
[0010] According to the invention, a model-based control method is used to control the temperature of the calibration volume to reach a target temperature. The required model of the dynamics of the controlled system preferably includes control and manipulated variables, such as the intensity or power of the adjustable cooling and heating elements, disturbances, such as the ambient temperature or variations in the supply voltage, and process variables, such as temperatures within the calibration volume or their changes over time.
[0011] The model can be implemented as a calculating rule on an electronic data processing unit, for example on a microcontroller within or outside of the calibrator. The thus formed model can calculate future values of the process variables as a function of possible values of the disturbance, control and manipulated variables.
[0012] The model can exist for example in the form of one or more transfer functions. It is advantageous that the associated transfer functions can be easily measured, because temperature measuring points are already integrated at the relevant positions in the temperature calibrator or there are corresponding sensor receptacles.
[0013] Alternatively, the model can also exist in the state-space representation. The corresponding model equations can then for example be derived from the known heat equation. Since a solution to the heat equation can usually be done only numerically for the geometry of a real temperature calibrator and is very expensive, it is advantageous to derive only the structure of the model equations from the heat equation and to determine the free parameters of the model by means of a measurement of the transfer functions.
[0014] In the case of a continuous-time modeling of the state dynamics, the model is preferably formulated as a linear system of differential equations
[0000]
x
_
(
t
)
t
=
A
x
_
(
t
)
+
B
u
_
(
t
)
,
[0000] wherein x (t) denotes the vector of the thermal state of the calibrator and the ambient environment and ū(t) denotes the vector of the control and manipulated variables.
[0015] The elements of the state vector are preferably formed of temperatures at the positions in the calibration volumes, temperatures at the positions in the heat conduction part of the calibrator, temperatures around or inside the housing of the calibrator and systematic differences in the temperature readings of temperature sensors.
[0016] Furthermore, the state vector may also include heat flows or temporal changes of temperatures. The elements of the vector of control and manipulated variables are preferably formed from the activation level or the power of heating and cooling elements. The values of matrices A and B can for example be determined by measuring the corresponding transfer functions.
[0017] In the case of a discrete-time modeling of the dynamics of states for the time points t n =t n−1 +θ with a suitable time increment θ, the model is preferably formulated as a linear difference equation x n =F· x n−1 +G·ū n−1 for the states x n = x (t n ). Here, the coefficients of the matrices F and G are preferably calculated by numerical or analytical integration of said differential equation system rather than by an implementation of the computation rule, and then implemented on a microcontroller or other compact electronic data processing unit. The resulting calculation rule in the form of a linear difference equation with constant-time matrices or matrices with constant-time coefficients can be carried out very quickly so that the model can also be used for fast control of the temperature calibrator with time increments of less than 100 ms.
[0018] In a preferred embodiment, the coefficients of the matrices F(T) and G(T) are calculated in dependence on the temperature of the calibration volume, and during the control of the calibration volume to a target temperature T target for modeling the dynamics of the states the matrices with constant time coefficients F(T target ) and G(T target ) are used. Due to this procedure, the temperature dependence of thermal conductivity and heat capacity caused by nonlinearity of the dynamics of states is sufficiently taken into account without increasing the complexity of the model because the associated computation rule is still a linear difference equation with time-constant coefficients.
[0019] The formulation of the model as a linear difference equation for the states x n = x (t n ) has the further advantage that it is identical with the prediction equation of the discrete Kalman filter which is preferably used for the estimation of states x n = x (t n ). In this case, the calculation result of the Kalman filter is referred to as an estimate, because it includes not only the actual values for the state but also the associated uncertainty estimation. The calculated estimated uncertainties lie in the case of temperature sensors used for temperature calibration typically in the range of a few milli-Kelvin so that in the scope of the invention, the estimation result of the Kalman filter is of sufficient accuracy for controlling the temperature of the calibration volume. The indirect determination of a temperature, for example at a place with difficult access in a furnace, by measuring a temperature at another easily accessible position by using a Kalman filter is a known method and was described by Mouzinho et al. [L. F. Mouzinho, J V FonsecaNeto, B. A. Luciano and R C S Freire, “INDIRECT MEASUREMENT OF THE TEMPERATURE VIA KALMAN FILTER” XVIII IMEKO World Congress, Metrology for a Sustainable Development, 17 to 22 Sep. 2006 Rio de Janeiro, Brazil].
[0020] It has been found that for achieving a high quality of control of the state vector, it must include a variety of temperatures at up to 20 different positions in the heat conducting part of the calibrator, which for example may be formed from the metal block of a portable dry-block calibrator. A measurement of the temperature at many positions is technically possible but correspondingly expensive. For this reason, temperatures are measured preferably only at one or two places in the heat conduction part by means of one or two integrated internal reference sensors and from them the remaining temperatures in the state vector are calculated by means of the Kalman filter. Subsequently, the estimate of the temperature condition can be improved by the use of the temperature measurement values of the temperature sensors located in the calibration volume. For this purpose, in addition to the measured values of the internal reference sensors, the measured values of one or more external reference sensors are preferably supplied to the Kalman filter.
[0021] It has further been found that the application of the Kalman filter described by Mouzinho et al. to estimate the temperatures at positions in the heat conduction part and in the calibration volume results in errors that may be in the order of some 10 mK. Although such deviations can be neglected for conventional indirect temperature measurements in industrial environments, they are not acceptable in the regulation of calibration devices for highly accurate temperature sensors. These deviations occur when the readings of more than one temperature sensor are supplied to the Kalman filter and are due to the fact that because of the uncertainty, two sensors in their calibration have a small but finite and, in particular, different systematic error in the measurements displayed. To control a temperature calibrator, these deviations cannot be neglected even with the use of high-precision traceable reference sensors.
[0022] According to an advantageous embodiment of the invention, using the Kalman filter, these deviations in the state estimation are taken into account in that a temperature sensor is selected in the calibrator, and the systematic deviations of the temperature readings from the other sensors are added relative to this reference sensor as being estimated time constant temperature differences of the state vector.
[0023] This has the consequence that while temperature values in the calibration volume and the heat conduction part estimated by the Kalman filter still have a bias based on the international temperature scale, this offset is the same for all temperatures and in all positions. This property is of central importance for the temperature control, because different systematic errors in the temperature values would result in systematically wrong heat flux predictions and thus to systematically wrong temperature estimates.
[0024] The reference sensor is preferably selected such that the measurement values exhibit the smallest systematic measurement deviation from the international temperature scale so that all of the temperature values calculated by the Kalman filter have this systematic error.
[0025] In an embodiment for quick calibration of temperature sensors, the temperature readings of the samples are supplied to the Kalman filter and the respective systematic deviations of the measured values in relation to the reference sensor are added to the state vector as the temperature offset to be estimated. The systematic deviation of the sample measurement values from the measured values of the reference standard is exactly the temperature offset to be determined by the calibration. This temperature offset of interest is usually determined by expensive comparison of the temperature measurement curves of the sample and the reference standard for a period of typically 30 minutes after reaching a stable temperature levels in the vicinity of the target temperature. According to an embodiment of the invention, the temperature offset calculated by the Kalman filter is available as an element of the state vector at any time during the calibration process and can be directly read or displayed. The displayed value for the temperature offset between the specimen and the reference standard is sufficiently stable typically after a few minutes after reaching the desired temperature and then corresponds to the offset of the temperature of the specimen relative to the reference standard, which is obtained by comparing the measured temperature curves over a longer period.
[0026] From the knowledge of the state of the calibrator estimated using the Kalman filter and the environment, it can be calculated, using the model of the dynamics of the states, how the control and manipulated variables must be set in the future for the future behavior of the process variables to come as close as possible to the desired behavior of the process variables. This optimal setting of the control and manipulated variables then results in an optimal behavior of the control variables.
[0027] If, for example, the goal is that the calibration volume be heated in the next 100 seconds to a nominal temperature of exactly 50° C., it can be calculated using a continuous-time model in the form of the above linear differential equation which temperatures T0 and T1000 will be reached when the heating power at this time is 0 or 1 kW. Due to the linearity of the differential equation, the optimum heat output in the observed 100 seconds is then (50° C.−T0)/(T1000−T0)*1 kW. The disadvantage of this approach is that, if the appropriate performance is even adjustable, although the desired 50° C. can be achieved exactly in 100 seconds, both before and after significant deviations from the target temperature can occur both before and after, e.g. in the form of overshoots.
[0028] Preferably, therefore, the desired behavior is specified as a minimum mean square deviation of the process variables from the reference values over a period of length τ instead of at a single point in time. To solve the resulting quadratic optimization problem quickly and with a sufficient optimization result, preferably a discrete-time model of the dynamics of the states in the form of a linear difference equation is used to calculate the resulting process variables and the number of the values considered as to be set for the control and manipulated variables is reduced to a small finite number greater than 1. Thus, the number of the temporal sequences of the control and manipulated variables to be considered in the optimization and the number of the resulting mean square deviations to be calculated by the model become finite.
[0029] It has been found that in order to avoid overshoots in the temperature behavior of the calibration volume, the time horizon τ, over which the course of the process variables is considered, is preferably longer than 10 seconds.
[0030] With a time horizon of only 15 seconds and only one control variable, which can assume only the values 0 or 1 and whose setting can be changed only every 0.5 second, there result 2̂30 and thus more than a billion possible timings of the control variable within this time horizon. Preferably, therefore, the number of the mean deviations of the process variables from the set point to be calculated is further reduced by not considering all possible timings of the control variables during the optimization, but rather only an appropriately selected subset. The resulting pseudo-optimal setting of the control variables is the timing of the control variables whose resulting mean square deviation is not greater than some mean-square deviation resulting from a different settings of the considered subset.
[0031] The subset is preferably selected as such number of settings, which deviate little from the optimal or pseudo optimal timing, which has been calculated in a previous optimization step.
[0032] The model-based control of the temperature of the calibration volume preferably includes the following four steps, which are repeated periodically in the order shown, with the associated cycle duration preferably less than one second. In the first step, a measurement of a subset of the current thermal state variables is performed. In the second step, the whole of the actual state variables is estimated on the basis of the values measured in the first step, a previous estimate of the total of the state variables and the previous values of the control and manipulated variables, preferably by means of a discrete Kalman filter.
[0033] In the third step, the optimal or pseudo-optimal values of control and manipulated variables, for which the future behavior of the process variables comes sufficiently close to the desired behavior of the control variables, is calculated, preferably by means of a discrete-time thermal model for the dynamics of the states. In the fourth step, the optimal values of the control and manipulated variables are set for the current time.
[0034] A particular advantage of the model-based control according to the invention is that for target temperatures above 500° C. it allows to reach temporal temperature stabilities which with about ±3 mK are better in the order of magnitude than the stabilities previously achieved for this temperature range. Thus, a highly accurate calibration can be performed in the region of high temperatures of up to 700° C.
[0035] Another advantage of the model-based predictive control of the temperature of the calibration volume is that overshoots are avoided in the process variable by calculating the deviations at several points in time in the future. Thereby, the temporal stability of the temperature of the calibration volume is reached faster.
BRIEF DESCRIPTION OF THE FIGURES
[0036] Further advantages, features and details emerge from the following description of an embodiment in conjunction with the drawings. In the drawings:
[0037] FIG. 1 shows a thermal model of a portable metal block calibrator having a metallic heat conduction part 2 and the calibration volume 3 , wherein in the first of the nine elements of the model 11 , 12 , . . . , 19 is a heat source 1 , in the fifth element of the model is an internal reference sensor 6 , and in the ninth element of the model is an external reference sensor 7 ;
[0038] FIG. 2 shows the Bode plot of amplitude 61 and phase 66 of the internal transfer function which results from a thermal model adapted to the amplitude measurement values 60 and phase measurement values 65 ;
[0039] FIG. 3 shows the Bode plot of amplitude 71 and phase 76 of the external transfer function that results from a thermal model adapted to the amplitude values 70 and phase measurements 75 ;
[0040] FIG. 4 shows temperature values 77 measured by means of the external reference sensor 7 , which values result during the control of the temperature of the calibration volume 3 of a metal block calibrator to a target temperature of 600° C. using an adapted thermal model.
DETAILED DESCRIPTION OF THE INVENTION
[0041] FIG. 1 shows a thermal model of a portable metal block calibrator, on whose basis hereinafter the control of the temperature of the calibration volume 3 of the metal block calibrator to a target temperature is performed.
[0042] Into the calibration volume 3 can be inserted metallic sleeves adapted to temperature sensors to be checked, with receiving bores 4 for the samples. The temperature of the calibration volume 3 is measured by means of an external reference sensor 7 . The indicator of the internal reference sensor 6 is the only source of information on the temperature distribution in the heat transfer part 2 which is designed as a metal block. To control the temperature of the calibration volume 3 to the desired target value, the heat sources 1 designed as heating elements can be activated or deactivated with an electronic control system. The outer sides of the heat conduction part 2 fulfill the function of a heat sink 5 . For modeling the dynamics of the thermal states, the cross section of the metal block calibrator is notionally divided into triangular elements of the same size and the temperature distribution in heat conduction part 2 and in the calibration volume 3 is represented by the temperatures of the individual elements of the thermal network. Due to the symmetry of the arrangement of the heat sources 1 designed as heating elements, it is sufficient to model only the illustrated three-side surface as a thermal network with the nine elements 11 , 12 , . . . , 19 , taking into account in the following that thermal energy from the network can flow only into the heat sink 5 . The thermal network of the nine elements 11 , 12 , . . . , 19 is supplied heat only via the heat source 1 in the first element 11 .
[0043] The temporal change of the temperature in an element is then given by the equation
[0000]
m
i
k
T
i
t
=
Q
i
.
[0000] Here m i is the mass of the element, k is the specific heat capacity of the metal used and Q l is the heat flow in the element. It results from the temperature differences from the adjacent elements and the associated heat transfer coefficient α ij , and contact surfaces L ij according to the equation Q l =α ij (T j −T i )+α il L il (T l −T l )+α in L in (T n −T i ).
[0044] For the state vector T (t) of the nine temperatures relative to ambient temperature thus results a linear system of differential equations
[0000]
T
_
(
t
)
t
=
A
T
_
(
t
)
+
Bu
(
t
)
[0000] with the control variable u(t) and the matrix B, which contains the free parameter p in the Form [p 0 0 0 0 0 0 0 0]′ because heat energy is supplied only into the first element 11 . It is assumed that the coefficients of heat transfer between all elements of the heat conduction part 2 designed as a metal block or all of the elements of the calibration volume 3 filled with the metallic insert sleeve are equal to each other.
[0045] However, they can differ both from the coefficient of heat transfer from the elements in the heat conduction part 2 to the heat sink 5 and from the coefficients of heat transfer from the elements in the heat conduction part 2 to the elements in the calibration volume 3 . If in addition, based on the geometric model uncertainty, one admits that the mass of an element in the calibration volume 3 is greater by a factor d than the mass of an element in the heat conduction part 2 of the metal block calibrator, the result for matrix A is the structure
[0000]
(
-
a
-
b
b
0
0
0
0
0
0
0
b
-
a
-
b
-
b
2
b
2
0
0
0
0
0
0
0
b
2
b
(
-
2
-
2
)
b
0
b
0
0
0
0
0
b
-
2
b
b
0
0
0
0
0
0
0
b
-
2
b
-
c
b
0
c
0
0
0
b
0
b
b
(
-
2
-
2
)
b
2
0
0
0
0
0
0
0
b
2
-
a
-
b
2
0
0
0
0
0
0
c
d
0
0
-
c
-
b
d
b
d
0
0
0
0
0
0
0
b
d
-
b
d
)
[0000] with the four free parameters a, b, c and d.
[0046] In order to determine the total free parameters p, a, b, c, and d of the thermal model, the amplitude values 60 and the phase values 65 of both the internal transfer function, i.e. the transfer from the heat source 1 to the temperature of the internal reference sensor 6 , and the amplitude values 70 and the phase values 75 of the external transfer function, i.e. the transfer from the internal reference sensor 6 to the temperature of the external reference sensor 7 , are measured for selected frequencies.
[0047] Subsequently, the transfer functions resulting from the linear system of differential equations for different values of the free parameters of the model are calculated and compared with the measured data. At a temperature of the calibration volume of 600° C. there results a good agreement with the measured values for p=0.11 K/s, a=0.0044 l/s, b=0.11 l/s, c=0.071 l/s and d=2.1, both for the Bode diagram of the internal transfer function with amplitude response 61 shown in FIG. 2 and phase response 66 as well as for the Bode diagram of the external transfer function shown in FIG. 3 with amplitude response 71 and phase characteristic 76.
[0048] In order to suitably reformulate the present thermal model, known as a linear system of differential equations with constant coefficients and known constant matrices A and B, for use in a discrete Kalman filter, an increment of time e of 100 ms for discrete-time modeling is chosen in this embodiment. From the amplitude 61 in the Bode diagram of the internal transfer function shown in FIG. 2 it can be concluded that due to the large thermal inertia of the heat conduction part 2 with an on/off control of the heat sources 1 with an associated clock frequency 1/θ of 10 Hz, a resolution significantly better than 1 μK can be achieved for the control of the temperature in the immediate vicinity of the internal reference sensor.
[0049] In the considered embodiment, in order to estimate the thermal conditions, the temperature readings of both the internal reference sensor 6 and the external reference sensor 7 with a refresh rate of 10 Hz are fed to the discrete Kalman filter. The signal noise 2σ of both reference sensors is about 4 mK.
[0050] The continuation of the thermal states to be estimated
[0000]
x
n
=
(
T
_
(
t
n
)
T
U
(
t
n
)
T
Offset
)
[0000] includes, in addition to the temperatures T (t n ) of the nine members of the thermal network at the points in times t n =t n−1 +100 ms, also the time-dependent ambient temperature T U (t n ) and the time-independent systematic offset T Offset between the measured temperature values of the internal reference sensor 6 and the external reference sensor 7 . This produces for the states the linear stochastic difference equation x n =F·x n−1 +G·u n−1 +w n−1 , from which result the matrices F and G with time-constant coefficients by integration of linear differential equation system with the previously determined time constant matrices A and B over a period of θ=100 ms with u(t)=0 (heat sources to) and u(t)=1 (heat sources from). The random variables w n represent the system noise and are assumed to be normally distributed with zero mean and covariance matrix Q. The temperature readings of the two references Θ In (t n ) and Θ Ex (t n ) result from the
[0000]
z
n
=
(
Θ
in
(
t
n
)
Θ
Ex
(
t
n
)
)
=
H
·
x
n
+
v
n
[0000] measurement equation with the measurement matrix
[0000]
H
=
[
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
]
.
[0000] The random variables v n represent the measurement noise and are assumed to be normally distributed with zero mean and covariance matrix R.
[0051] The central component and the main advantage of the discrete Kalman filter used in this embodiment is that in addition to the estimation of a state x n , the uncertainty of this estimate is always calculated in the form of the estimation error covariance matrix P n .
[0052] In the predicting step for the point in time t n−1 are determined both the estimator for the state and the associated covariance matrix initially only using the estimation results for the point in time t n−1 according to the first model equation in the form of a linear difference equation with a time constant coefficients {circumflex over (x)} n − =F·{circumflex over (x)} n−1 +G·u n−1 and the second model equation of the Kalman filter P n − =F·P n−1 ·F′+Q. In the following sub-step of the Kalman filter, this prediction is corrected, with consideration of temperatures (Θ In , Θ Ex ) t =z n measured at the point in time t n , according to the correction equations {circumflex over (x)} n ={circumflex over (x)} n − +K n (z n −H{circumflex over (x)} n − ) and P n =(I−K n ·H)·P n − . The so- called Kalman gain is given by K n =P n − ·H t ·(H·P n − ·H t +R) −1 .
[0053] After the estimate of the current thermal condition x n in the previous process step the first model equation of the Kalman filter can be used again in the form of a linear difference equation with time-constant coefficients to estimate, for each bit sequence (u n , u n+1 , . . . , u n+N ) of the future values (0/1) of the control variable u (t) over the time horizon t=30 s, which chronology ({circumflex over (T)} Ex (t n+1 ), {circumflex over (T)} Ex (t n+2 , . . . , {circumflex over (T)} Ex (t n+N+1 ) would result in the temperature readings of the external reference 7 from the associated heating profile of the heat sources. In order to achieve a fast and stable control, such a sequence of bits is now set, from which such a time sequence results, at which within the horizon τ the mean square deviation of the temperature of the external reference from the set temperature is as small as possible.
[0054] In order to obtain within the selected time increment θ of 100 ms a sufficient result of the quadratic optimization in the form of a pseudo optimal bit sequence, the bit sequence, which has been calculated in the previous control period as the pseudo optimal, is used as a starting sequence of the optimization and, by randomly inverting individual bits of this starting sequence, more bit sequences are generated so that an appropriate subset of all possible settings of the control variable is created, on which then the dynamics of the states and quadratic optimization can be predicted.
[0055] The discrete-time thermal model in the form of a linear difference equation with time-constant coefficients derived for the metal block calibrator considered in the embodiment is used in this manner both in the process step to estimate the thermal state and in the process step to determine the (pseudo) optimal setting of the control variable. This exemplary model-based control method yielded for the regulation of the calibration volume 3 of the metal block calibrator modeled in the embodiment to a target temperature of 600° C. in FIG. 4 a very stable control performance with a double standard deviation of the displayed temperature values 77 of the external reference sensor of 2σ≦3 mK.
LIST OF REFERENCE NUMBERS
[0000]
1 Heat Source
2 Heat conducting part
3 Calibration volume
4 Receiving bore for the sample
5 Heat sink
6 Internal reference sensor
7 External transducer
11 1 . Element of the model
12 2 . Element of the model
13 3 . Element of the model
14 4 . Element of the model
15 5 . Element of the model
16 6 . Element of the model
17 7 . Element of the model
18 8 . Element of the model
19 9 . Element of the model
60 Amplitude measurement values for the internal transfer function
61 Amplitude characteristic of the internal transfer function
65 Phase measurement values for the internal transfer function
66 Phase response of the internal transfer function
70 Amplitude measurement values for the external transfer function
71 Amplitude characteristic of the internal transfer function
75 Phase measurement values for the external transfer function
76 Phase response of the external transfer function
77 Displayed temperature values of the external reference sensor | The invention relates to a method for regulating the temperature of the calibration volume of an apparatus for comparative calibration of temperature sensors to a target temperature, wherein said calibration device comprises heat sources and/or heat sinks, which are in thermal contact via a heat conducting part or a plurality of heat conducting parts with the calibration volume, wherein in at least one process step the real thermal state is calculated, wherein the Kalman filter is fed the measurement values of a temperature sensor located in the calibration device, and in at least one more process step the future thermal state is calculated using a thermal model of the dynamics of states. | 6 |
The Government has rights in this invention pursuant to Contract No. F19628-80-C0002, awarded by the U.S. Air Force.
CROSS REFERENCE TO RELATED APPLICATION
The present application is related to the copending application of Hwang, Chen and Ragonese entitled A DIGITALLY CONTROLLED WIDEBAND PHASE SHIFTER, Ser. No. 735,990 filed May 20, 1985, now U.S. Pat. No. 4,638,190 assigned to the Assignee of the present invention, and filed concurrently herewith.
BACKGROUND OF THE INVENTlON
1. Field of the lnvention
The invention relates to stepped signal scaling and more particularly to a metal semiconductor field effect transistor (MESFET) designed for operation at frequencies ranging from a fraction of a gigahertz to many gigahertz, the signal transfer (gain and/or attenuation) being stepped in discrete steps over a given range of transfer values. Signal scaling finds major application to antenna arrays.
2. Description of the Prior Art
Monolithic microwave integrated circuit (MMIC) technology has proven useful in electronic circuitry operating at frequencies in the gigahertz range. The technology relies largely on the definition of the active and passive components and their interconnections by a precise, and repeatable photolithographic technique on a monolithic substrate. A preferred substrate material is gallium arsenide. Application of the technology results in a compact and electrically efficient design. The circuits and devices fabricated from this material function well at these frequencies and are capable of precise engineering characterization.
Typically, signal gain in the transmission or reception of signals involving antenna arrays must be adjusted either row by row or element by element. The adjusting means depending upon the number of rows or elements of the array, must be of such accuracy as to preserve the accuracy inherent in focusing or the steering of the array. The adjusting means should be sufficiently broadband as not to distort the signal, often broadband, which is being processed.
It has been proposed that a dual gate MESFET be used for signal gain control. In this application, the signal is applied to the number 1 gate, the gate closest to the source, and a gain control voltage is applied to the number 2 gate, the gate closest to the drain. The control effected by this means is highly non-linear in the conventional device. In addition, because there are many variables effecting the signal transfer value, this approach has lacked precision and repeatability.
An inherent problem in the referenced design is that when the voltage applied to the control gate is changed, both the gain and the phase of the output signal also change. The complex transfer value is additionally dependent upon the biasing, upon the geometry, and upon process dependent characteristics of the device. The result is that the device is difficult to characterize in practice, and when characterized, difficult to employ without compensation. Thus, it has become desirable to find an approach to signal scaling in which the signal gain or attenuation may be adjusted largely independently of phase, and in which the transfer function is precise and repeatable.
SUMMARY OF THE INVENTION
An object of the invention is to provide an improved signal scaling MESFET in which the small AC signal transfer is adjustable in selected discrete steps.
It is another object of the invention to provide an improved signal scaling MESFET for use at frequencies ranging from tenths of a gigahertz to tens of gigahertz.
It is a further object of the invention to provide a stepwise signal scaling MESFET for use at gigahertz frequencies wherein changes in amplitude may be achieved without a substantial change in phase.
It is an additional object of the invention to provide an accurate signal scaling MESFET for use at gigahertz frequencies applicable to signals of wide bandwidth.
It is still another object of the invention to provide a stepwise adjusted, signal scaling MESFET for use at gigahertz frequencies, which has a substantially constant input impedance at each setting to reduce reflective signal loss due to impedance mismatching.
It is another object of the invention to provide a small AC signal scaling MESFET for use at gigahertz frequencies having improved input/output isolation.
These and other objects are achieved in accordance with the invention in a monolithically integrated MESFET having a small AC signal transfer which is adjustable in discrete steps. The MESFET is an active MESFET, subdivided into an n-fold plurality of selectively activated MESFET segments, each of a predetermined width, with dual gates for each segment.
The MESFET is provided with a single terminal for application of an AC input signal to the first gates of all n segments, a drain terminal for application of drain potentials and derivation of an AC output signal (from all n segments), a source terminal for application of source potentials, and an n-fold plurality of segment activating terminals for selective application of DC control potentials to the second, activating gate of each of the n segments.
The MESFET segments each include an electroded source region, an electroded drain region, and a gate region. The gate region of each segment is provided with a signal gate, connected in common with the signal gates of all the other segments, and disposed between the source and the second, activating gate electrode. The signal gate electrode is designed to modify the output signal current of the MESFET segment as a function of its transconductance, the transconductance being substantially proportional to the width of the segment. The gate region has a second, activating gate electrode individually connected to a segment activating terminal, and disposed between the signal gate and the drain. The activating gate electrode is designed to turn current flow in the individual segment "ON" and "OFF". These conditions correspond respectively to substantial cut-off and substantial saturation of the segment.
The n-fold MESFET segment transconductances are weighted such that when the segments are activated in successive combinations, a desired series of MESFET transfer values is achieved. The MESFET transfer values are each substantially constant in a small AC signal sense and successive values are stepped at intervals depending upon the application. For instance, in the event that it is desired to provide a linearly scaled output, in which the gain is stepped in proportion to a series of consecutive integers, one may use binary scaling in which successive segments are of twice the transconductance of the preceeding segment (i.e. 1, 2, 4, etc. achieved by doubling the width of succeeding segments). In this manner, consecutive transconductances proportional to 0, 1, 2, 3, 4, 5, 6, 7, etc. may be achieved, under the control of a conventional binary coded signal of three bits (or more). The transconductance of successive combinations may also be scaled for logarithmically or arbitrarily stepped values.
In accordance with a further aspect of the invention, vernier or trimming steps may be achieved, either to extend the range or to increase the resolution, by using a voltage divider for applying the signal to the segments representing the smaller steps. This allows the width of the smaller width segment to be increased in proportion to the division ratio while not increasing the equivalent transconductance, a practice which restores the signal transfer to the desired value, while avoiding the disadvantages of unduly narrow gates.
The segmented dual MESFET is fabricated ussing monolithic microwave integrated circuit (MMIC) techniques on a semi-insulating substrate having locally active semiconductor regions. A preferred substrate material is gallium arsenide. The MESFET (including segment electrodes and segment interconnections), and the electrical connections and signal paths to the MESFET, the essential passive components connected to the MESFET for signal coupling and filtering are formed on the substrate and defined by a photolithographic process.
The technique permits very compact minimum reactance segment interconnections reducing deleterious parasitics, facilitating virtual unitary MESFET operation to very high frequencies, and broadband scaling.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel and distinctive features of the invention are set forth in the claims. The invention itself, however, together with further objects and advantages thereof may best be understood by reference to the following description and accompanying drawings in which:
FIGS. 1A and 1B are plan views of a novel monolithically integrated segmented dual gate MESFET designed for accurate signal scaling;
FIG. 1A is a plan view of the MESFET at an intermediate stage in the assembly illustrating the electrodes of individual segments of the MESFET and the pads at the perimeter of the semiconductor substrate; and
FIG. 1B is a plan view of the MESFET of FIG. 1A at a later stage in the assembly, after connections between electrodes and pads are complete;
FIG. 2 is a circuit diagram of the MESFET illustrated in FIG. 1; and
FIGS. 3A and 3B are simplified equivalent circuit models of a segment of the signal scaling MESFET illustrated in FIGS. 1A and 1B corresponding to operation in the "ON" and "OFF" states, respectively;
FIGS. 4A and 4B are graphs illustrating the performance of the embodiment illustrated in FIGS. 1A and 1B;
FIG. 4A illustrates the constancy of the output signal magnitude with frequency and the constancy of the scaling ratios; and
FIG. 4B illustrates the constancy of phase with frequency and more particularly the independance of the phase, at a given frequency, with respect to scaling ratios;
FIG. 5 is a circuit diagram of an attenuator suitable for use from UHF to X-band wherein a second segmented dual gate MESFET is provided in series with a first device for providing additional vernier steps to supplement the coarser steps provided by the initial device; and
FIG. 6 is a plan view of the MESFET illustrated in FIG. 5, at an intermediate stage in the assembly at which electrodes and pads are in place, but before bridges have been added.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A novel monolithically integrated signal scaling MESFET embodying the invention is shown in FIGS. 1A, 1B and 2. The MESFET is of a segmented dual gate design having a first gate (G1) for signal input and a second gate (G2) for activation of each segment into which the total MESFET is divided. The individual segments, which are fully functional active MESFET devices, have the widths noted in the circuit diagram of FIG. 2. The metallizations of the individual source, drain and gate segments of the MESFET and of the pads for external connection are as shown in FIG. 1A. Afterwards, air bridges and serial resistances are added, as shown in FIG. 1B, to complete the connections between segments and between segments and the external pads.
The signal scaling MESFET provides an accurately stepped voltage transfer function to an applied small AC signal over broad microwave bandwidths. The stepped transfer function, which consists of a series of constant transfer values, is achieved by dividing the MESFET into a plurality of individual segments and by activating or inactivating individual segments to achieve a desired active gate width. In the first embodiment, the control is achieved in sixteen steps by selective activation of four individual segments (A, B, C, D) having respective gate widths of 50, 100, 200, and 400 microns. Selective activation of the segments allows the MESFET to exhibit sixteen active gate widths from 0 to 750 microns in 50 micron increments. The equivalent transconductances, which may be obtained approximately by multiplying the active gate widths by a constant, is thus also available in sixteen steps.
The signal scaling MESFET, since it is an active MESFET device, may be designed to provide a signal transfer of moderate gain or attenuation. Larger devices provide higher gain and better accuracy, but do so at the cost of larger substrate areas and greater DC power consumption. In typical designs, the signal transfer value (gain) is one, or a few decibels below one, at the highest transconductance setting.
The metallizations and a principal portion of the substrate of the MESFET are shown in FIGS. 1A and 1B. For high frequency operation (up to at least 10 gHz), the substrate is preferably of gallium arsenide, a semi-insulating material capable of being modified to form semiconducting regions suitable for transistor formation. The two most prevalent methods of transistor formation are direct ion implantation or the provision of an expitaxial layer which is semiconducting and which is etched away to form localized mesas suitable for semiconductor activity. The MESFET is formed on a square GaAs substrate approximately 800 microns by 800 microns, with pads P1-P7 for external connection being provided around the periphery of the substrate. The semiconducting region of the substrate is generally rectangular in shape, being approximately 200 by 260 microns, and may be identified by five relatively broad, mutually parallel rectangular metallizations 17, 18, 19, 20, and 21-22 (the lowermost metallizations having two parts). The remainder of the substrate (beyond the 200 by 260 micron region) is semi-insulating permitting conductor runs, transmission lines, capacitors and resistors to be formed on the substrate without significant loss. The MESFET and the circuitry leading to and including the pads at the perimeter of the substrate are formed on the substrate and defined by a lithographic process.
The metallizations 17-31, which are parts of the source, drain and gate electrodes of the FET, are arranged in an interdigitated design. The three broad metalizations 17, 19 and 21-22, at the top, middle and bottom respectively of the electrode set, are part of the drain electrodes for all of the individual segments. The remaining broad metallizations 18 and 20 are a part of the source electrodes for all of the individual segments. The very narrow line-like metallizations which run in parallel between adjoining source and drain metallizations [e.g. (17-18); (18-19); etc.] and which occur in pairs, are the first and second gate electrodes shown in the circuit diagram of FIG. 2. Numbered in pairs from top to bottom, the gate metallizations are (23,24), (25,26), (27,28) and in the bottom most set (29, (30, 31)) where 29 is the continuous upper gate metallization and 30 is the lower gate metallization to the left and 31 for the lower gate metallization to the right.
The pads P1 to P7 are connected to the metallizations 17 to 31 as follows. The pad P1 is the signal input pad. As seen in FIG. 2, the signal input pad is connected to the input signal gate of all four segments of the segmented MESFET. The input signal gate (per FIG. 2) is the gate nearest the source and for that reason may be referred to as the number 1 gate. The pad P1 is provided with two Y-shaped metallizations 32 and 33 respectively at the left edge. The bases of the Y-shaped metallizations 32, 33 abut the pad P1 and the branched ends lead to the full length line-like input signal gate metallizations 24, 25, 28, 29. More particularly, the upper branch of the upper Y metallization 32 is connected to the input signal gate metallization 24 and the lower branch of 32 is connected to the input signal gate metallization 25. The upper branch of the lower Y metallization 33 is connected to the input signal gate metallization 28 and the lower branch is connected to the input signal gate metallization 29.
The pad P2 (per FIG. 2) is the signal output connection for the drains of all four segments of the segmented MESFET. As best seen in FIG. 1B, the drain pad P2 leads upwards toward a connection to the lowermost right drain metallization 22. An air bridge 34 connects the drain metallization 22 to the other lowermost drain metallization 21. An air bridge 35, connects the centrally disposed drain metallization 19 via 22 to the drain pad P2. Finally, an air bridge 36 connects the uppermost drain metallization 17 via 19, via 22 to the drain pad P2.
The pad P3 is the source pad and makes connection (per FIG. 2) to the sources of all four segments of the segmented MESFET. As best seen in FIG. 1B, the source pad P3 leads downwards toward an air bridge 37 spanning the uppermost metallization 17 (a drain) and making contact to the upper source metallization 18. A second air bridge 38 leading downward from metallization 18 spans the metallization 19 and makes contact with the lower source metallization 20, completing the path between pad P3 and metallization 20.
The remaining pads P4, P5, P6, P7 provide independent connections to the line-like metallizations (23, 26, 27, 31, 30) of the activating gates of each MESFET segment via individual 2000 ohm resistors. (The activating gate is furthest from the source and may be referred to as the number two gate.) The activating gates provide a visual means of identifying on FIGS. 1A and 1B the individual A, B, C, and D segments of the MESFET.
As shown in FIG. 1A, the pad P4, which is associated with the A segment, leads upwardly via a 2000 ohm resistance 40, which has short pads at either end. The short line-like activating gate metallization 30 which extends to the right from the upper resistance pad has a "width" of approximately one-quarter the length of the source and drain metallization (17-20) and is of the least width. Activating gate 30 is coextensive in width with and defines the 50 micron wide A segment of the MESFET.
The pad P5 in the lower right corner of FIG. 1A is associated with the B segment and is connected via a 2000 ohm resistance 41, which has pads at either end, to the line-like activating gate metallization 31. The gate metallization 31 which extends to the left from the upper resistance pad has a "width" of approximately one-half the length of the source and drain metallizations (17-20). Activating gate 31 is coextensive in width with and defines the 100 micron wide B segment of the MESFET.
The pad P6 at the left center of FIG. 1A is associated with the C segment and is connected via a 2000 ohm resistance 42, which has pads at either end, to the line-like activating gate metalization 27. The gate metallization 27, which is disposed to the right of the rightmost resistance pad, is approximately the length of the principal source and drain metallizations (17-20). Activating gate 27 is coextensive in width with and defines the 200 micron wide C segment of the MESFET.
The pad P7 in the upper left corner of FIG. 1A is associated with the D segment and is connected via a 2000 ohm resistance 43 and via a U-shaped metallization 44 to the two part line-like activating gate metallizations 23, 26. In particular, the "base" of the U-shaped metallization 44, abuts the right pad of the resistance 43. The upper branch of the "U" is connected to the gate metallization 23 and the lower branch of the "U" is connected to the gate metallization 26. The two metallizations 23 and 26 each extend for the length of the principal source and drain metallizations and by virtue of being connected together have a combined width of 400 microns. They define the width of the D segment of the MESFET as being 400 microns and equal to twice the length of the source and drain metallizations (17-20).
The individual segments (A, B, C, and D) are fully electroded, fully functional MESFET devices which may be activated selectively to determine the transfer value (scaling factor) applied to the input signal as it progresses to the signal output terminal (drain) of the MESFET. The transfer value is attributable to the transconductance of the MESFET, which is the parameter controlling the scaling of the signal, and which is in turn controlled by the width of individual segments. FIGS. 3A and 3B are simplified equivalent circuit models of a dual gate MESFET segment; FIG. 3A representing the "ON" state and FIG. 3B the "OFF" state. The equivalent circuit model is applicable to the transmission of small AC signals in the operating frequency range and is applicable to the segments individually and in combinations.
The MESFET segment is represented in both FIGS. 3A and 3B as a device with four external terminals (not including ground). The pad P1 is the ungrounded signal input terminal leading to the first gate of the segment. The pad P2 is the signal output terminal leading from the segment drain. The pad P3 is the terminal for connection to the segment source and the pad Pn is the terminal to the activating gate of the (nth) segment combination. The equivalent circuit representations are applicable over two or three decades of frequency (i.e. from hundreds of megahertz to tens or perhaps hundreds of gHz). The diagram includes a substantial number of parasitic resistances and capacitances whose value remains substantially the same in the "ON" and "OFF" states of the segment; and a transconductance (Gm) and a drain-source conductance (Gds) which vary between the "ON" and "OFF" states.
More particularly, the equivalent circuit of the MESFET segment combination in FIGS. 3A, 3B includes a gate resistance Rg, a gate to drain capacitance Cgd and a drain resistance Rd in the series path between pads P1 and P2. A first shunt path interconnected between the Rg-Cgd terminal and source pad P3 comprises the gate to source capacitance Cgs, an intrinsic resistance Ri and source resistance Rs. The active region of the MESFET segment is further represented in FIG. 3A by three elements including the transconductance Gm "ON", the drain to source conductance Gds "ON" and the drain to source capacitance Cds, each mutually connected in shunt between the Cgd-Rd terminal and the Ri-Rs terminal. The active region of the MESFET segment is further depicted in FIGS. 3A and 3B by the notations "ON" and "OFF" applicable to the transconductance, (Gm) and to the drain to source conductance (Gds), which are different for the "ON" and "OFF" states. The second gate region is depicted as the drain to G2 resistance Rdg2 shunted by the drain to G2 capacitance Cdg2, the combination being connected between the Cgd-Rd terminal and the activating pad Pn (n denoting the nth segment combination). An external capacitance Ce, which appears at the pad Pn, is useful to explaining device operation.
The equivalent circuit representations of FIGS. 3A and 3B are designed to illustrate the MESFET segment in the "ON" state wherein the device is operated between saturation and "pinch-off". The MESFET devices may be operated in principle in either the depletion mode or enhancement mode, but those herein illustrated are designed for depletion mode operation.
The model and in particular the Gm prediction can be scaled with substantial accuracy with gate width provided that the geometry, terminal voltage and external impedances remain the same. The MESFET is operated with practical loads and accordingly a given Gm will produce a signal transfer (gain or attenuation) in that load which reflects the Gm, but which may not be exactly proportional to Gm as the Gm is scaled. If exact signal scaling ratios are desired, then the Gm values must be tailored to fit the practical application. The tailoring may be regarded as being attributable to the loading effect from parallelled devices exhibiting finite output impedances, the back-gating effect from the non-ideal nature of the substrate, and fringing fields at the smaller gate widths. The scaling may approach the ideal by using good material, good design rules and accurate simulating software. The scaling, when under binary digital control, is readily applied with 4, 5, or 6 bit accuracy. Certain procedures such as the one illustrated in FIGS. 5 and 6 may be used to extend the range up to 10 bit accuracy.
The performance of the segmented dual gate MESFET so far described is illustrated in FIGS. 4A and 4B. FIG. 4A illustrates the magnitude of the output signal under test conditions over the band of 1,000 to 1,500 megahertz at each of the five settings of the activating control (0000,0001, 0010, 0100, and 1000). The illustrated magnitudes are constant and in constant relative proportions (i.e. scaling) to one part in a hundred. FIG. 4B illustrates the phase versus frequency performance of the first embodiment. In particular, the phase is examined over the frequency range of 1,000 to 1,500 megahertz at each of the active settings of the scaler. It may be seen that the phase, which is at approximately 144.2° at 1,000 megahertz is substantially the same (within 1%) at each setting of the activating gates within the illustrated frequency ranges and drifts less than 10% (16°) over the illustrated frequency range.
The embodiment illustrated in FIGS. 1A and 1B provides a step wise linear count of relative transconductance values in integers from zero to seven. One may also implement non-linear steps such as that required for trigonometric functions. A particularly simple approximation of trigonometric scaling may be provided by a three segment gate controlled by a four bit signal. The gate width ratios of the three channels are one to four to eight which by suitable combinations achieves a divide by 13 scheme (i.e. 0/13, 5/13, 9/13, 12/13, 13/13) to provide sine or cosine values at 22.5° intervals between 0° and 90°. For 111/4° intervals between 0° to 90°, a divide by 50 approximation controlled by a 5-bit signal may be employed in which the successive effective segment widths have the values of 0/50, 10/50, 19/50, 29/50, 35/50, 41/50, 46/50, 49/50 and 50/50. In both examples, the error of the approximation is never greater than 2%. The same two approximations may be computer optimized. If the weights of the three segment MESFET for the 221/2° intervals are in the proportions of 1:3.613:7.524, an error of less than 1/2% is to be expected. If the weights of the five segment MESFET for 111/4° intervals are in the proportions of 1:1.45535:2.14035:5.25838:10.95002 then an error of less than 0.8% is to be expected. The application of the scaler and the choice of scaling weights for phase shifting is the subject of the above cited patent application to Messrs Hwang and Chen.
An attenuator having logarithmic scaling suitable for use from UHF to X-band is illustrated in FIGS. 5 and 6. The attenuation varies from zero to greater than 10 db under digital control utilizing 6 coarse (greater than 1 db) settings and four fine (0.2 db) settings. The coarse settings are produced by a first relatively large, four segment MESFET 51 while the fine settings are produced by a three segment MESFET 56 having a first segment width of 169 microns followed by a voltage divider coupling the signal to two smaller segments of 20 and 40 microns width respectivly. The circuit associated with the three segment device 56, illustrates the provision of high resolution attenuation steps.
FIG. 5 in particular provides an electrical circuit diagram of both the coarse and trimmer sections of the attenuator. The drawing indicates the circuit values and the gate widths utilized in the trimmer section. FIG. 6 illustrates the layout of the trimmer section.
As shown in FIG. 5, the input signal to the attenuator is coupled to the signal input pad 50 which is coupled via a 4 picofarad capacitor to the number 1 signal input gates of the segments T1, T2, T3, T4 of the first MESFET 51. The signal input gates are returned via a 2000 ohm resistance to the pad 63 connected to the negative gate supply voltage. The sources of the MESFET segments T1, T2, T3, T4 are connected to substrate ground and the number 2 activating gates are connected through 2K resistances to activating control terminals 52, 53, 54, 55 respectively. The drains of the segments T1, T2, T3 and T4 are connected together and lead via a first load resistance RL1 of 50 ohms to a positive drain source terminal 62, which is bypassed by a 10 picofarad capacity C10, to ground.
The signal from the drain of the MESFET 51 (continuing to trace the circuit diagram of FIG. 5) is then coupled via a 4 picofarad capacitor C2 to the signal gate, common to the three segments of the MESFET 56 in the vernier section of the attenuator. The capacitor-terminal connected to the T5 signal gate, is connected via a 200 ohm resistance to the number 1 signal gates of the T6 and T7 segments and via a 2000 ohm resistance to the pad 63 connected to the negative source supply voltage. A second resistance of 50 ohms connects the signal gates of T6-T7 to the negative source, and forms a voltage division (having a ratio of 5 to 1) of the signal coupled to the attenuator segments T6-T7. The sources of the segments T5, T6, and T7 are connected together and to substrate ground. The three number 2 activating gates of T5, T6, T7 are connected to activating control terminals 57, 58, 59 respectively. The drains of the three segments T5, T6, T7 are connected via a 50 ohm load resistance RL2 to the B+ supply terminal 61 which is bypassed to ground with a 10 picofarad capacitor C12. The signal output appears at the common drain connection of T5, T6, T7 and is coupled via a four picofarad capacitor C3 to the signal output terminal 60.
The logarithmic attenuator of FIG. 5 was fabricated using monolithic microwave circuit fabrication techniques on a gallium arsenide substrate having overall dimensions of approximately 1400 microns by 1600 microns. The MESFETS of the FIG. 5, 6 embodiment have a linear non-interdigitated layout. In the trimmer section, the set of segments T5, T6, and T7 of MESFET 56 are in line, and have the same azimuthal orientation. In the "in line" design, the source, number 1 gate, number 2 gate and drain metallizations occur in the same order along the same coordinate (i.e. from top of the drawing to the bottom).
In the orientations of FIG. 6, the three MESFET segments T5, T6, and T7 of the trimmer section of the attenuator are shown in the center of the substrate with pads for external connection being shown along the top edge, right edge and bottom edge of the illustrated portion of the substrate. Each of the segments is oriented with the drain being uppermost, the number 2 activating gate being next below, the number 1 signal gate being below that, and the drains being lowermost. Each segment of the MESFET 56 is formed on a localized semiconducting region formed on the semi-insulating gallium arsenide substrate. The surrounding semi-insulating region supports inter-segmental connections, DC and signal connections to the MESFET, and passive components such as the signal coupling capacitors (C2, C2 and voltage divider (R1 R2); and filtering and power supply components (RL1, C12). Each feature is formed on the gallium arsenide substrate and defined by a photolithographic process.
The path of the signal proceeds generally from left to right in the FIG. 6 illustration being introduced at the left edge of the substrate via the metallization 66 which leads to the capacitor C2. The capacitor C2 is then connected via a short metallization to the number one signal gate of T5 and then via the voltage divider R1, R2 to the number one signal gates of segments T6 and T7. The attenuator output signal is derived from a metallization 67 coupled to the drains of T5, T6 and T7, which is coupled upward via a filter network consisting of load resistance RL2 and bypass capacitor C12 to the pad 61 for application to a source of positive drain potentials. The signal from metallization 67 is coupled via the capacitor C3 via a downward extending metallization 68 to the signal output pad 60. The sources of the devices T5, T6, and T7 are illustrated connected together to substrate ground. The number 1 signal gates of MESFET T5, are coupled via the resistance R3 to the pad 63 at the lower left corner of the substrate. The segment activating gates are each coupled via a 2000 ohm resistance to the pads 57, 58 and 59 at the top edge of the substrate.
The "in line" design has a process advantage with devices of smaller geometries. For instance, an error in mask positioning, which offsets all of the gates along a coordinate perpendicular to the gate, will produce the same effect on all MESFET segments. In the interdigitated structure, assuming that the order of the source and drain are interchanged in half of the segments, the same mask displacement will place one set of gates closer to the source and the alternate set of gates closer to the drain. The result is that alternate devices will have differing operating characteristics. This problem is most severe at the higher resolutions, but at lower resolutions is only one of many factors which must be taken into account when establishing a satisfactory MMIC layout.
The present invention provides a method of scaling the gain of a MESFET by partitioning the MESFET into segments of differing width dimensions, and selectively activating different combinations of segments. The scaling therefor becomes proportional to the transconductances of the activated segments, which in turn are dependent on the respective widths of the segments. Since the segments are operated in an "ON/OFF" mode (i.e. "activated"), the scaling retains its accuracy irrespective of changes in bias, in temperature and in many process variations. These changes, which affect each segment proportionately, do not--to a first order at least--affect the scaling which the dual gate segmented MESFET produces.
The scaling range or the finess of the resolution may be increased by the use of the voltage divider illustrated in the FIGS. 5, 6 embodiment. Without the use of the 5 to 1 step down voltage divider, the gates subject to the step down ratio would have had to be one-fifth the gate width finally employed. Because of fringing effects and inaccuracies, gate width scaling down to gate widths of a few microns (normally less than 10 microns) is often impractical. With the voltage divider having a division ratio of 5 to 1, the gate widths may be multiplied by a factor of approximately 5, which increases the transconductance by a factor of five to achieve approximately the same overall gain. Thus with the use of a supplemental voltage divider, the voltage scaling can assume a wider scaling range or finer resolution when fixed input and output impedances are assumed.
As earlier noted, with binary segment scaling, 4, 5, and 6 bit signal scaling is quite practical, while with the use of the voltage division technique, the scaling may be extended several more bits, depending on application.
The vernier principle may be applied within a MESFET to apply to the finer segments or it may be applied between two MESFETS, one designed for coarse steps and the other designed for the finer steps.
The signal transfer of the segmented dual gate MESFET may provide either a stepped attenuation, a stepped gain, or stepped signal scaling in which the range incompasses both attenuation and gain. At a signal at a given frequency within the range of application of the invention, whether narrow band or broad band, a change in signal amplitude is not accompanied by a substantial change in phase.
In principle, the scaling property is dependent upon scaling the transconductance of the individual segments, which is achieved by adjusting the widths of the individual segments. The signal gain may be calculated as a function of the input signal voltage, the transconductance which produces a corresponding output signal current, and a load resistance in which the output signal current flows and produces an output signal voltage. In practical applications, exact gate width dimensions are obtained by taking into account those parameters significantly impacting the signal transfer calculation.
The use of a dual gate design for the individual MESFET segments has two further advantages in most practical applications. The presence of the second, activating gate acts as a shield between the signal input gate and the signal output drain and greatly enhances the input-output isolation. The isolation gives greater accuracy in scaling by reducing the feedthrough capacity. In addition, the dual gate design tends to retain a substantially constant input impedance due to the fixed nature of the parasitics in the equivalent circuit at the first gate which change very little between the active and inactive states. Thus the segmental dual gate MESFET devices, when inserted in a circuit, may be designed to match the characteristic impedances of the connecting transmission lines (e.g. 50 ohms), and will preserve the match throughout the range of settings of the attenuator. Thus signal losses due to reflections of the attenuator will remain quite low.
The segmented dual gate MESFET herein described is a broad band device often operable over an octave of the frequency spectrum in practical realizations. In principle, there is no lower frequency limit. However, in practice the VHF frequencies may represent the lower limit at which the design has practical advantages over competing techniques. The upper frequency limit is established by the gain and parasitics of a given device viewed as an amplifier. A current upper limit using gallium arsenide devices with 1 micron gates is approximately 10 gigahertz. The bandwidth of the device is ordinarily measured in terms of the tolerable change in relative phase at different settings of the scaler. Accordingly, assuming a system application in which a 5 degree error in relative phase is tolerable, a bandwidth of 10% can be achieved at 5 gigahertz. Since the phase error increases at the upper limits of operation and decreases at the lower limits, a full octave of operation below these frequencies is ordinarily available without a significant increase in the phase error.
As previously stated, the scaler herein described makes use of the extraordinary characteristics of a method of circuit fabrication currently known as "MMIC" (monolithic microwave integrated circuit) technology. In current usage, the term "MMIC" implies a circuit fabrication technique in which active and passive components are formed by a photolithographic process on an insulating substrate having both electrically active regions, in which transistors may be formed, and electrically passive regions, in which conductive runs, transmission lines, inductors, capacitors and resistors may be formed. The fabrication technique, except for external connections to the pads made at the perimeter of the MMIC component, is throughout a photolithographic process controlled by large scale masks which may be generated by computer aided methods and which lend themselves to an automated mode of fabrication.
The word "monolithic" in the term "MMIC" implies the use of a single crystal, insulating, semi-insulating or semiconductor substrate upon which passive and active circuit elements may be fabricated and interconnected in accordance with one of several competing semiconductor technologies. At higher frequencies, the substrate material currently preferred for its semiconducting properties is gallium arsenide which has a high carrier (electron) mobility. In addition, gallium arsenide classified as a semi-insulator is available with the high bulk resistivity required to support low loss transmission lines and low loss conductive paths and required to provide good isolation between components. Gallium arsenide has a high dielectric instant (13.0) which is a factor, not always beneficial, influencing the transmission path design.
The word "microwave" in the term "MMIC" generally expresses the frequencies at which integrated circuits incorporating this technology are functional. Commonly the word implies circuit functionality at frequencies of 300 megahertz to 300,000 megahertz (Webster's New World Dictionary, p. 898). While some definitions may recognize no upper limit (e.g. "from about 1000 megahertz upwards" IEEE Standard Dictionary of Electronic and Electrical Terms, 3rd Edition, 1984), the word is also used to imply suitability for applications at much lower operating frequencies where high frequency response (at microwave frequencies) can improve circuit performance.
Functionality of an integrated circuit over the "microwave" portion of the radio frequency spectrum requires both good transistors in the active regions of the substrate as well as good passive devices and good point to point connections in the passive regions. In respect to the latter, the microwave transmission paths should be of reasonable efficiency and the conductive runs should be of low loss and good crossover techniques essential to any general circuit strategy such as "air bridges" should be present.
The term "integrated circuit" in the term "MMIC" implies that circuit components are formed integrally with the substrate by the photolithographic techniques discussed earlier, and that the circuit comprises pluralities of interconnected components, at least some of which are active.
MMIC technology is to be distinguished from "hybrid" monolithic integrated circuit technology. The dimensions of MMIC components, whether passive or active, are orders of magnitude smaller than lumped discrete components characteristic of the "hybrid" monolithic integrated circuit technology. In hybrid MIC technology, IC chips, transistor chips, capacitors, and resistors, etc. are treated as discrete components to be interconnected by wire bonds or similar non photolithographic techniques. Wire bond interconnections pose both the problem of creating electrical discontinuities at high frequencies by unwanted parasitic reactances and of introducing a variability in electrical characterization not present in a photolithographically defined interconnection technique.
The smaller dimensions characteristic of MMIC technology often reduces the phase delays in conductive paths and transmission lines to near negligibility. For instance, a differential signal path length of 200 microns, reasonable for the devices herein described, corresponds to a phase aberration of less than 2° at 10 gigahertz, where 10° would be tolerable. The smaller sizes and shorter distances between components characteristic of MMIC technology also reduce the parasitic capacitances and inductances within the active devices and in the interconnections between passive and active devices. These factors permit operation at frequencies as high as C-band (5-6 gigahertz) and often beyond with little difficulty.
Finally, both passive and active components can be matched with precision more economically with MMIC technology than with discrete technology. Large area metallizations, such as are used for capacitor plates or high current transmission lines are of course, highly accurate in an absolute sense. While absolute values may be somewhat more variable in small area devices, "tracking" or "matching" is often present. The symmetry attributable to common design rules in computer assisted layouts used in forming comparable devices contributes to this high degree of matching. In addition, the technology, which uses methods such as mask defined conductor runs and air bridges provides accuracy in conductor layouts with a repeatability which is not present in any other process.
In practical terms, MMIC technology has made possible the fabrication of the scaler herein described which is functional at frequencies as high as 5 gigahertz. In the embodiment of the scaler illustrated in FIG. 6, multiple active MESFET segments cooperate as parts of a unitary active MESFET with accurately formed resistive and capacitive elements and with efficient signal paths in close association with the MESFET to achieve a high frequency performance that cannot be matched by the discrete MIC technology.
While the monolithically integrated active MESFET herein described has particular advantage at very high frequencies, it is inherently a broadband device capable of working from DC to the very high microwave regions. At low frequencies, the segmented MESFET exhibits high input and output impedances due to low device capacitances and a very low feedback capacitance. This permits the device to be used at lower frequencies for high precision applications because of its low circuit loading and low internal feedback. For example, at lower frequencies attenuators having up to 60 db of attenuation or five bit phase shifters with less than five degrees of phase error can be built using MMIC technology. | A novel signal scaling MESFET of a segmented dual gate design is disclosed. The MESFET, which is monolithically integrated on a semi-insulating substrate capable of localized surface modification to form active semiconductor regions using MMIC (monolithic microwave integrated circuit) techniques, has a small AC signal transfer which is adjustable in selected discrete steps. For operation in the gigahertz range, the substrate is preferably of gallium arsenide.
In applying the MMIC technique, the MESFET, including segment electrodes and segment interconnections, and the electrical connections, signal paths, and passive components connected to the MESFET are formed on the substrate and defined by a photolithographic process. The technique permits reproducable feature definition and very compact minimum reactance segment interconnections, reducing deleterious parasitics and facilitating virtual unitary MESFET operation to very high frequencies.
The signal scaling MESFET is an active MESFET subdivided into an n-fold plurality of selectively activated MESFET segments, each of a predetermined width, with dual gates for each segment. The AC input signal is applied to the first gates of all n segments and a DC control potential is selectively applied to the second activating gate of each of the n segments to turn current flow "ON" or "OFF" in selected segments. The MESFET transfer values so formed are each substantially constant in a small AC signal sense and successive values are stepped at intervals suitable for linear, trigonometric, logarithmic or arbitrary scaling functions. | 7 |
BACKGROUND
[0001] Today's social networks revolve primarily around a reference point of a particular user. This model allows a user to express and share opinions and content/media with their direct connections (sometimes referred to as “friends” or “connections”). Having a flat model removes the ability to have contextual interactions. For example, people that have a lot of “friends” in their network could get bombarded with posts from people that are not really that close or important; thus obscuring other interactions (e.g., posts) that may be more important. Disclosed are systems and methods to address these and other issues via embodiments of a contextual social network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] Example embodiments of the present disclosure will be more readily understood from reading the following description and by reference to the accompanying drawings, in which:
[0003] FIG. 1 illustrates a typical flat social network model.
[0004] FIG. 2 illustrates a contextual social network according to one or more disclosed embodiments.
[0005] FIG. 3 illustrates roles in a contextual social network according to one or more disclosed embodiments.
[0006] FIG. 4 illustrates an example of context member types in a contextual social network according to one or more disclosed embodiments.
[0007] FIG. 5 illustrates a possible association of a user with a context of a contextual social network according to one or more disclosed embodiments.
[0008] FIG. 6 illustrates an association of one context with another context in a contextual social network according to one or more disclosed embodiments.
[0009] FIG. 7 illustrates a network boundary definition in a contextual social network according to one or more disclosed embodiments.
[0010] FIG. 8 illustrates a network definition for a first and second user with different policies for a first context and a second context according to one or more disclosed embodiments.
[0011] FIG. 9 illustrates a “network-all” boundary definition according to one or more disclosed embodiments.
[0012] FIG. 10 illustrates context and sub-context types according to one or more disclosed embodiments.
[0013] FIG. 11 illustrates an example contextual network for families and parents raising children according to one or more disclosed embodiments.
[0014] FIG. 12 illustrates an example of the contextual social network applied for an enterprise example according to one or more disclosed embodiments.
[0015] FIG. 13 illustrates an example of a school as a context according to one or more disclosed embodiments.
[0016] FIG. 14 illustrates an example of a class context connected with a school context according to one or more disclosed embodiments.
[0017] FIG. 15 illustrates an example of a family & children as a context associated with other contexts (e.g. class) according to one or more disclosed embodiments.
[0018] FIG. 16 illustrates formation of a contextual network through invitations and accepts according to one or more disclosed embodiments.
[0019] FIG. 17 illustrates communication and interaction for a parent in a children centric contextual network according to one or more disclosed embodiments.
[0020] FIG. 18 illustrates communication/coordination for a teacher in a children centric contextual network according to one or more disclosed embodiments.
[0021] FIG. 19 illustrates communication/interaction for a school administrator in a children centric contextual network according to one or more disclosed embodiments.
[0022] FIG. 20 illustrates a communication stream in a children centric contextual network according to one or more disclosed embodiments.
[0023] FIG. 21 illustrates interactions in trusted boundaries according to one or more disclosed embodiments.
[0024] FIG. 22 illustrates interactions with users belonging to multiple trusted boundaries according to one or more disclosed embodiments.
[0025] FIG. 23 illustrates a teacher interacting with peers through a trusted boundary in the context of a school according to one or more disclosed embodiments.
[0026] FIG. 24 illustrates a parent interacting in a trusted boundary in the context of her son's class according to one or more disclosed embodiments.
[0027] FIG. 25 illustrates relevance/meaning in interactions—parent example according to one or more disclosed embodiments.
[0028] FIG. 26 illustrates relevance/meaning in calendar events according to one or more disclosed embodiments.
[0029] FIG. 27 illustrates transience concepts relative to a contextual social network according to one or more disclosed embodiments.
[0030] FIG. 28 illustrates a transience example for a parent before re-association according to one or more disclosed embodiments.
[0031] FIG. 29 illustrates a transience example for a parent after re-association according to one or more disclosed embodiments.
DETAILED DESCRIPTION
[0032] Having a social network model that is flat removes the ability to have contextual interactions. This limits the ability of these types of networks to be applicable in the real world, where most interactions are contextual. We have our lives where the people we interact with at work, family, school, social environments, etc. are each very different. And we have conversations and interactions specific to each of these “worlds” and the flatness of today's social networks causes several limitations (e.g.,):
Removes this context; and Limits the interactions due to lack of trust boundaries.
[0035] Disclosed are embodiments of a model for a social network that allows interactions between users on a social network based, in part, on contexts so that their interactions have more relevance and meaning to the users. This model enhances the user experience by allowing interactions that preserve the “trust” and “environmental” boundaries that are present in the real world interactions between users when taking into account a context for the relationship.
[0036] Terminology
[0000]
User
Any user of a social network with an identity (for
example a user identified by an email address).
Context
A primitive that brings together a group of users around a
subject that is meaningful to those users.
Relationship
How a user or a context is associated with another user or
context.
Interaction
Any content that is created and shared in the context -
could be text messages, photographs, events, static
information, etc.
Trust Boundary
Defines who can participate in an interaction on a
context.
Relevance/
Defines why a user sees an interaction (e.g., contextual
Meaning
association).
[0037] FIG. 1 illustrates a simple model ( 100 ) for a flat “user-based” social network. In this model, a given user is illustrated by a shaded circle ( 105 ). Users u1 ( 107 ) and u2 ( 109 ) are connected through a simple relationship “r” ( 108 ). In a real world this relationship could just be a “friend” type relationship.
[0038] As the network grows, many users can establish relationships with other users and each user could have a set of connections to interact with (a simple example is illustrated by graph 115 ). Connections can bring an “order” to the relationships. For example in the network represented in graph 115 , these relationships may be represented by attributes of Table 1 shown below:
[0000]
TABLE 1
Interactions in a flat social network
Third Order
First Order
Second Order
(Friend of Friend
User
(Friend)
(Friend of Friend)
of Friend)
u1
u4, u2
u3, u6
u6, u5
u2
u1, u6
u4, u3, u5
u3, u4
[0039] FIG. 2 illustrates, via graphical representation, an example of a contextual social network. In this particular model a user “u” ( 205 ) is only associated with another user through a context “C” ( 210 ). This is as opposed to being directly related to another user as is typical in the “flat” social network of FIG. 1 . There are at least two types of relationships possible within the disclosed contextual social network model. First, a user can be connected to a context as shown in relationship 215 . Second, a context can be connected to another context as shown in relationship 220 .
[0040] These two types of relationships can permit interactions between users to have the following properties in addition to the properties available for users of a social network with only flat interactions:
Trusted Boundary (Who can see this?) Relevance/Meaning (Why am I seeing this?)
[0043] For example, Table 2 below describes some sample interactions for the users in the contextual social network outlined in graphical representation 225 .
[0044] When a user u11 ( 230 ) creates an interaction with a boundary definition of “1”, or one level of context, the user who can participate in that interaction is u12 ( 235 ). For user u12 ( 235 ), the relevance/meaning is represented by the Context “C1” ( 240 ). For example if the user u11 ( 230 ) creates a message to be shared into the context C1 ( 240 ), the trusted boundary definition decides who can see that message, and the receivers of the message can know why they are seeing that message (e.g., “they are associated with the same context as the user who created that message”). In some embodiments, the information providing context of the message is prominently presented to the user when the message is received and thus enhances the message by providing the contextual association (e.g., reason for the message).
[0045] When the user u11 ( 230 ) creates an interaction with a boundary definition of “2”, or two levels of context, the users who can participate in this interaction are u12 ( 235 ), u31, u32, u41, u42. For example, when a user u11 ( 235 ) shares a photograph with the trusted boundary definition of two, the users who can see this photograph are associated with contexts that are in turn associated with the context C1 ( 240 ) user u11 ( 230 ) is associated with, and their Relevance/Meaning describes the contextual association path. For example user u31 is able to see this photograph because of the association with C3 which is in turn associated with C1 ( 240 ). Also the Relevance/Meaning that user u31 sees attached to that photograph can be derived from “C3←C1”, which represents the context path for the contextual relationship (e.g., contextual association path).
[0000]
TABLE 2
Interactions in a contextual social network
Boundary
Users in Trusted
User
Definition
Boundary
Relevance/Meaning
u11
1, C1
u12
u12: C1
u11
2, C1, C3, C4
u12, u31, u32,
u12: C1
u41, u42
u31: C3←C1
u32: C3←C1
u41: C4←C1
u42: C4←C1
[0046] There also exist possible extensions to the basic Context Model disclosed above. The following “hard” rules are according to one example embodiment and could be varied in other embodiments without departing from the scope of this disclosure:
[0047] Roles (e.g., Special Relationships with Contexts).
[0048] Contexts are always associated with at least one user (i.e., there are no “orphaned” contexts). There are at least three basic types of users who may have a special role relationship with a given context. These are illustrated graphically in FIG. 3 graph 300 . First there can be an “Owner” relationship ( 305 ) where the context can have a single owner that has permissions to create/update/delete all interactions and memberships associated with the context and its relations with other contexts. The owner is the only role that can delete a context, or transfer the ownership of the context to another user. Second, there can be an “Administrator” relationship ( 310 ) where the administrator may create/update/delete all interactions and memberships associated with the context and its relations with other contexts. The administrator cannot delete the context or transfer the ownership of the context. Third, there can be a “Member” relationship ( 315 ) where the member of a context may create interactions associated with the context, and may update/delete them based on the context policies. A member does not have the rights to manage the memberships or the association of the context with other contexts. Throughout this document a member of a context under the “normal” member relationship is also referred to as a “user associated with” the context.
[0049] Membership Types
[0050] The members of a Context may be further grouped or partitioned by member types. This can provide a further level of managing trust and connectivity with respect to a context. For example in FIG. 4 , the interaction ( 405 ) created by user u1 ( 410 ) in the Context C ( 415 ) may be visible only to user u2 ( 420 ), because both u1 ( 410 ) and u2 ( 420 ) are members of Context C ( 415 ) via membership type m2 ( 440 ). Interaction ( 405 ) will not be visible to users u3 ( 430 ) and u4 ( 435 ) because they are associated with the Context C ( 415 ) through membership type m1 ( 440 ). However all interactions are visible to the owner “o” ( 445 ) and administrator “a” ( 450 ) per the “Role” policy discussed above. Because a context may be associated with other contexts, a membership type may also be used to facilitate how one context is associated with another context. For example, in FIG. 4 , C2 ( 455 ) is associated with C ( 415 ) through the membership type m1 ( 440 ). This can allow users (not shown) who are associated with C2 ( 455 ) to participate in interactions of C2 ( 455 ) that are limited to membership type m1 ( 440 ). For example, the owner o ( 455 ) of C ( 415 ) may want to post a message that is limited to all members who are connected to C ( 415 ) through m1 ( 440 ). This will be available now to members of C2 ( 455 ), who may then respond to it, or participate in that interaction in another manner.
[0051] Associations
[0052] The association of a user with a context or that of a context with another context is typically done through invitations. For example in FIG. 5 diagram 500 , the owner “o” ( 505 ) of a context “C” ( 510 ) invites a user “u” ( 515 ) to be associated with C ( 510 ) with membership type “m” ( 520 ) (step-1 530 ). When a user “u” ( 515 ) accepts (Step-2 540 ), the association “a” ( 525 ) between user u ( 515 ) and context C ( 510 ) can be created.
[0053] A similar method can be adopted to create an association between contexts. For example in FIG. 6 diagram 600 , the owner “o1” ( 605 ) of a context “C1” ( 610 ) invites owner “o2” ( 615 ) of another context “C2” ( 620 ), for C2 ( 620 ) to be associated with C1 ( 610 ) through membership type m (Step-1 640 ). When o2 ( 615 ) accepts the invitation, then an association “a” ( 630 ) between C2 ( 620 ) and C1 ( 610 ) can be created (Step-2 650 ).
[0054] Network Boundary
[0055] In a contextual network, the definition of “a network” for a user could be defined at the level of a set of contexts, and based on the role of a user for those context(s). For example, in FIG. 7 , contexts C1 ( 705 ), C2 ( 710 ), and C3 ( 715 ), all have policies that allow all their memberships to be visible to two levels of association. So the network for user u11 consists of users (u12, u21, u22, u31 & u32).
[0056] In FIG. 8 , contexts C2 ( 805 ) and C3 ( 810 ) have a more restrictive policy—that only their Owners are visible to the second level of context associations. In this case the network definition of u11 will be (u12, O2, and o3), where o2 is the owner of the context C2 ( 805 ) and o3 is the owner of the context C3 ( 810 ). Similarly, the network definition of U12 would be (u11, o2, and o3).
[0057] Network all Boundary
[0058] A special type of network boundary may be made available for a special type of interaction that allows interactions to be visible across connected contexts without any limitation to the depth of association (e.g., any number of levels can exist between the connected contexts). These may also be controlled using a policy attribute of a context. For example in FIG. 9 contexts C2 ( 905 ), C3 ( 910 ), and C4 ( 915 ) each have policies that allow interactions marked as “Networked-ALL” to be passed to all their members (users and contexts). In this case an interaction created by user u11 ( 920 ) marked “Network-ALL” will be visible to u42 ( 925 ) (associated with Context C4 915 ), because contexts C3 ( 910 ) and C4 ( 915 ) both have policies that allow Network-ALL interactions to be passed on without consideration of the depth of context associations.
[0059] Context Types
[0060] Contexts may be classified based on whether they contain sub-Contexts or not. For example in FIG. 10 , the Context C ( 1005 ) is a simple context which does not contain sub-Contexts. FIG. 10 also shows a context C′ ( 1010 ) that contains two sub-contexts c1 ( 1015 ) and c2 ( 1020 ). Sub-Contexts can derive their ownerships and administrators from their parent-context. For example in FIG. 10 , “o” ( 1025 ) is the owner of the context C′ ( 1010 ), and hence also the owner of sub-contexts c1 ( 1015 ) and c2 ( 1020 ). Memberships may also be inherited by the sub-contexts. For example all users of C′ ( 1010 ) are also users of sub-contexts c1 ( 1015 ) and c2 ( 1020 ). However a user specific to sub-context c1 (for example, u1 ( 1030 )) is not a member of c2 ( 1020 ). Further refinements of these models are possible to allow for flexibility in the construction of a contextual social network targeted at specific applications.
[0061] Context Policies
[0062] Contexts can have several policies associated with them.
[0000] Basic policies such as:
Only the owner can delete the context; and Only the owner can transfer the ownership of the context.
Membership policies such as:
Allow other contexts to associate or only users.
Network boundaries can be defined at the context level such as:
Allow visibility to memberships based on network depth; Allow visibility to memberships based on membership types; and Allow Network-All visibilities.
[0069] The following sections illustrate example Applications of a Contextual Social Network.
[0070] Families and Community Around Children
[0071] This use-case example for a contextual network model describes how parents, families and communities around children could come together will well defined trust boundaries to share privately and schedule/coordinate to reduce the chaos in their lives and focus on what's important—raising children.
[0072] An example model 1100 for such a network is shown in FIG. 11 . The number of users shown in this network is limited for simplicity, and the network is likely to be much larger in a real world example consisting of many schools, leagues, classes, teams, families, etc.
[0073] Some highlights of this example network 1100 include:
[0074] Users:
Three sets of parents—Mom1 ( 1105 ), Dad1 ( 1110 ), Mom2 ( 1115 ), Dad2 ( 1120 ), Mom3 ( 1125 ), and Dad3 ( 1130 ). Teacher1 ( 1135 ) & Teacher 2 ( 1140 )—school teachers. Principal 1 ( 1145 )—principal of a school. School District Administrator 1 ( 1150 )—manages a school district. Coach 1 ( 1155 )—coaches a team. League Administrator 1 ( 1160 )—manages a league with multiple teams.
The following are the “Contexts” in example network 1100 :
Families—F1 ( 1165 ), F2 ( 1170 ), and F3 ( 1175 ). Children belonging to these families—c11, c12, c21, c22, c31, and c32. An extended family ( 1180 )—“Ext Family 1.” A Close Friends context ( 1185 )—“Close Friends 1.” Classes—Class1, Class2, Class3 and “other classes.” Teams—Team1, and Team2. School—School 1 and “other schools.” League—League 1 School District—School District 1 Sports League—League 1
[0091] Trusted boundary examples relative to example network 1100 .
[0092] A picture of c11 shared by Dad1 ( 1110 ) with a boundary definition of one would be shared with Mom1 1105 (via context F1 ( 1165 )), Mom2 1115 (via context Ext Family 1 ( 1180 )), Mom3 1135 (via context Close Friends 1 ( 1185 )). Teacher 1 ( 1135 ) could share a lesson plan with Mom1 ( 1105 ) via the context path (c11←Class1). Mom1 ( 1105 ) could then comment on the lesson plan within the context of family F1 ( 1165 ). A message to all principals of School District 1 could be sent by School District Administrator 1 ( 1150 ).
[0093] Relevance/meaning examples relative to example network 1100 .
[0094] Mom1 ( 1105 ) can see a photo of c11 posted by Teacher 1 ( 1135 ) in the Class 1 context, with the context path “c11←Class1” providing relevance/meaning. Dad1 ( 1110 ) can see an event scheduled by the School District Administrator 1 ( 1150 ) with the context path “c11←Class1←School1←School District1.” Dad2 ( 1120 ) could receive a special message about c21 from League Administrator 1 ( 1160 ) that carries the context path “c21←Team1League1.” When the same message is re-shared by Dad2 ( 1120 ) with Dad1 ( 1110 ), Dad1 ( 1110 ) sees that message with a context path “Close Friends1” ( 1185 ).
[0095] Transience examples relative to example network 1100 .
[0096] When c11 moves from Class 1 to Class 3, the connection with other parents of Class1, Teacher1 and Principal1(School1) can be automatically removed and new connections with Class 3, and the new School can be automatically established without the need to “unfriend” or remove all the individual transient associations in c11's network.
[0097] Enterprise organizations could also benefit by using a contextual social network that mirrors the organizational structure. FIG. 12 shows an example network 1200 of the contextual social network applied for an example enterprise. As enterprises evolve from outdated communication models centered around email and file-sharing, applying social collaboration models that have trusted boundaries and relevance/meaning in interactions can become increasingly important for productivity and efficiency.
[0098] A typical business organization is organized by key functions. This example shows how such a functionally organized enterprise may be setup using a contextual social network. The network shown in this example can be extended all the way down to each employee of the enterprise, each connected locally to the respective contexts but also connected across the enterprise through the context network.
[0099] Users in this example network include:
The CEO ( 1205 ). The Board members ( 1210 ). The heads of the various functions—Head of Sales ( 1215 ), Chief Marketing Officer (CMO ( 1220 )), and Chief Technical Officer (CTO ( 1225 )) of Products. The next level of executives (e.g., Vice Presidents) for each of these functions 1230 . etc. (e.g., employees 1235 and other lower level contexts)
The following are some of the “Contexts” in this sample network
The company 1250 . Sales ( 1255 ), Sales-US ( 1260 ), and Sales-Europe ( 1265 ). Marketing ( 1270 ), Corporate Marketing ( 1275 ), and Product Marketing ( 1280 ). Products ( 1285 ), Engineering ( 1290 ), Quality ( 1295 ), and Manufacturing ( 1296 ).
[0109] Trusted boundary examples relative to example network 1200 .
[0110] The board consists of the CEO ( 1205 ), Head of Sales ( 1215 ), and other board members ( 1210 ). The Head of Sales 1215 and other board members are connected to the “The Company” context ( 1250 ) via the member type “Board”. The CEO ( 1205 ) is a member of the member type “Board” in this example because he is the owner of the company context 1250 . All interactions by members of the board in this example network are in the context of the company, but may reside in the trusted boundary defined by the membership type board because of their membership association (and the CEO's ( 1205 ) context ownership).
[0111] When the CEO ( 1205 ) initiates a message/post for that he wants to send to all employees of the company, he can mark the interaction as “Network-ALL”. All the contexts in the example network 1200 are configured by their policy to pass the Network-ALL interactions, so these interactions are available to all employees. When the Head of Sales ( 1215 ) would like to discuss the monthly sales for US he can create a message in the “Sales” context ( 1255 ) for the members of the context “US” ( 1260 ).
[0112] Relevance/meaning examples with respect to example network 1200 .
[0113] Employees all receive the message from CEO 1205 and see the message from the CEO relative to the network path traversed via the levels of contexts. This path information can provide significant relevance/meaning for the message. All US sales representatives can see the message from Head of Sales ( 1215 ) while the European sales team will not see that same message.
[0114] Transience examples relative to example network 1200 .
[0115] When/if VPS1 of US changes jobs with VPS2 of Europe only those two connections need to be updated and the contextual network model retains its meaning.
[0116] Network of contexts relative to example network 1200 .
[0117] The disclosed contextual social network provides a network of contexts, instead of just users. This can allow the ability to apply the platform for any vertical application and make the experience meaningful/relevant.
[0118] Examples of one possible user interface via screen shot samples:
[0119] A network of school, classes, and children built in the way communications flows with the ability to attach children to classes and snap multiple classes into a single organization. See FIG. 13 screenshot 1300 . The school administration (superintendent and principal here) have a network of classes by grade level. Eric Stephens is the Principal (OWNER) of the school St. John's School (CONTEXT) 1305 , and has his School Organized by grades Pre-K 1310 , Kinder 1315 etc. (MEMBER GROUPS).
[0120] The respective teachers/classes associated with his school by their grade specific member groups. For example Erica Miller, a Kinder teacher is the OWNER of a class Ms. Miller's Kinder Class (CONTEXT) and is associated to St. John's School (CONTEXT) via the member group Kinder.
[0121] Each class has a network of children (and parents through their children) connected to the teacher and ultimately the school. Here, the teacher is the class administrator and the school administrator has been added as second administrator or assistant giving them administrative privileges for managing the class connections.
[0122] FIG. 14 screenshot 1400 shows Erica Miller (OWNER) of a class, Ms. Miller's Kinder Class (CONTEXT) associated with St. John's School (another CONTEXT). The parents of the various children in the class are associated with the class through the member group called “Children”. Here for example, Carrie Marshall who is the mother of Sam 1405 is associated with Ms. Miller's Kinder Class through the member group “Children”.
[0123] Parents are connected to the school in the context of their child's class. For example in FIG. 15 screenshot 1500 , Carrie Marshall, mom, is the OWNER of the CONTEXT “Marshall Family”. Eric Marshall, dad, is an ADMINISTRATOR of the Marshall Family Context. There are three children (SUB-CONTEXTS, as described with respect to FIG. 10 )—Peter 1505 , Ashley 1510 , and Sam 1515 . Sam 1515 is associated with Ms. Miller's Kinder Class (as in FIG. 14 above), and with three other contexts—Turtles Soccer, Cowboys Football, and Heat Volleyball (see 1520 ). Please note that each of these contexts (teams) may be associated with other contexts (example a League). The association of a context and users can be formed through invitations and accepts (outlined described above with respect to FIG. 6 ). For example, in FIG. 16 screenshot 1600 shows an interface where a parent could accept an invite into a team (“Sporty Soccer”) and possibly into the league for that team, both relationships are in the context of the selected children.
[0124] The network of contacts can be used for communications, interactions, scheduling and messaging within the network that comes together around children (parents, teachers, coaches, principals, league administrators, etc.) from children up through the respective organizations in the context of the child, class, team and ultimately the school/league. Each user is able to see their connection and the context of the communication, event, etc. The parent is able to see class/team/group connections for each child—a contextual network. See FIG. 17 screenshot 1700 .
[0125] The teacher sees the group she owns (her class) and the organization to which her class belongs (the school). She is able to communicate and create events in the context of either or both. See FIG. 18 screenshot 1800 .
[0126] The school administrator is connected to each class and able to communicate through to the parents based on the contextual network. See FIG. 19 screenshot 1900 .
[0127] Communication stream carried out through network of contacts and contextual relevance. See FIG. 20 screenshot 2000 .
[0128] Trusted Boundary
[0129] The disclosed contextual social network provides an ability to create trusted boundaries for its users in a natural way as their application demands, and in a way that mimics the real world interactions in these example verticals.
[0130] In FIG. 21 , screenshot 2100 illustrates that the principal is able to interact with other users in his contextual network across trusted boundaries very easily. For example, when posting a message to a specific groups of users exposed in the user interface via a drop down menu. Using the same option the principal can also communicate with more than one set of users by multi-selecting the options in the drop down ( FIG. 22 screenshot 2200 ).
[0131] As a teacher within a school like St. Johns, there are options to communicate (Posts/Events) in the context of their class, or with a group of peers. For example, FIG. 23 screenshot 2300 illustrates a group event. Only the members in the Kinder Staff group will be able to see this event. All the teachers of Kinder classes are associated with St. Johns through the Kinder Staff Member group and this forms a trusted boundary.
[0132] As a Parent, there are similar options to communicate (Posts/Events) with your immediate and extended families, as well as within the context of a group that their child is connected to. This is illustrated in FIG. 24 screenshot 2400 .
[0133] Relevance/Meaning
[0134] Relevance and meaning in interactions is built into the core of the platform (in contrast with trying to extract the meaning after the fact based on data mining these interactions). This also mimics the real world—the conversations we have at the work place are very different from those we have with the teacher of our child, or our doctors because the context is different. We don't try to derive the meaning based on the content of these conversations, but because of the context in which these interactions take place (school, doctor's office, workplace, etc.).
[0135] In the example illustrated in FIG. 25 screenshot 2500 , a parent is interacting with the users in her contextual network. The interactions (in this case conversations or messages) carry the context with them so that the meanings of the conversations are implicit. The parent can easily determine the relevance of these interactions instead of having to figure out how they are connected with the creator of these messages.
[0136] In this example, the contexts of posts are shown not only in posts on the conversations page, but within the shared calendar as well. Both of these areas share the same sharing construct, so the same aspect of context is carried through to both. This is illustrated in FIG. 26 screenshot 2600 .
[0137] Transience
[0138] Relationships are formed based on contexts as opposed to being static. For example, your child's second grade friends and their parents are going to be very different from when she goes to third grade. This does not mean that you have to “friend” all her kindergarten friend's parents and then “unfriend” them when she goes to the first grade. These networks should be automatically formed based on the context (i.e. kindergarten, first grade, etc.). The disclosed contextual social network can make these transitions natural, seamless and automatic relative to any context connection updates.
[0139] The example below illustrates how this aspect of transience manifests for a parent in the context of her son. FIG. 27 screenshot 2700 shows an example of a class (Ms. Millers), and the current members. As children change teams, classes, and youth groups, so can the network of connections they have within a contextual social network. Once a class ends, the connections with the other parents in that class can also end, and the access (from that class's context) to your child ends. In FIG. 28 screenshot 2800 , Sam, who is Carrie's (mom) son is shown attached to Ms. Miller's Kinder Class. Carrie's contacts will include all the users who are connected through Ms. Miller's class (Other parents of children in that class, the teacher, the principal of the school that Ms. Miller is associated with, etc.). As connections change, they can also change under the view of each child. Only current connections will show. Once a connection to a group ends, it is no longer shown. This is illustrated in FIG. 29 screenshot 2900 , where now Sam is in Julie Sayer's class, and is no longer connected with Ms. Miller's class. So the connections and other interactions can change accordingly.
[0140] The foregoing description and disclosed embodiments can be implemented on one or more computer processors specifically configured to support users in a contextual social network. Infrastructure networks can contain one or more computer networks. Computer networks can include many different types of computer networks available today such as the Internet, a corporate network or a Local Area Network (LAN). Each of these networks can contain wired or wireless devices and operate using any number of network protocols (e.g., TCP/IP). Networks are typically connected to gateways and routers, end user computers and computer servers. Also, infrastructure networks can include cellular networks for use with cellular communication. As is known in the art, cellular networks support cell phones and many other types of devices (e.g., tablet computers, PDAs or lap top computers, etc.). Obviously cell phones can be smart phones or other devices of similar capabilities.
[0141] Example processing devices for use in providing disclosed contextual social network interactions according to one embodiment include different levels of processing power relative to their functions. Servers hosting and maintaining the contextual social network may be server class hardware as opposed to an end-user interface which could be implemented in a browser or handheld computer (e.g., cell phone) for example. | Disclosed are systems and methods to implement a contextual social network. A contextual social network adds a relationship based at least in part on a context of the relationship. For example, a child may be a student at a school and in turn a student in a particular kindergarten class at that school. As of the next school year the child can maintain the relationship with the school but replace the relationship with the kindergarten class to a relationship with a first grade class. When the child goes to a different school the original school relationship can be replaced with a new one. While the child is in a particular school or class at school the parents of the child have an indirect relationship (e.g., through their child) with the same school and class. The indirect relationship can automatically change as the relationship of the child to the school changes. | 7 |
This application is a continuation application of the U.S. patent application Ser. No. 09/482,052, filed on Jan. 13, 2000, now U.S. Pat. No. 6,273,853 which is a continuation of U.S. Application Ser. No. 08/940,766, filed on Sep. 30, 1997 now U.S. Pat. No. 6,102,854.
FIELD OF THE INVENTION
The present invention relates to the field of cardiac surgery instrumentation and more specifically to the surgical method and apparatus optimized for coronary bypass operations.
BACKGROUND OF THE INVENTION
Direct coronary artery revascularization on a beating heart was conducted, both experimentally and clinically, in the 1950's and the 1960's, without stabilization.
Challenges associated with this surgical technique are as follows:
complete anastomosis is very difficult to achieve due to the motion of the beating heart;
the technique is limited to vessels of a minimum diameter—again due to difficulty in the anastomosis technique on a beating heart;
lifting of the heart for revascularization of posterior arteries results in a precipitous drop in arterial pressure;
the learning curve for surgeons performing this technique is very high; negotiating the learning curve may represent significant surgical morbidity and mortality.
The development of the cardio-pulmonary machine for extracorporeal circulation (ECC) enables coronary operations on an arrested heart. This allows the surgeon to operate on a perfectly still heart and to manipulate the heart to expose the target artery.
At the present time, the standard coronary artery bypass graft (CABG) procedure typically requires a full median sternotomy and extracorporeal circulation through a cardio-pulmonary machine.
Even with the constant technological improvements achieved during the last twenty-five years, the advantages offered with ECC have been offset by morbidity and mortality related to the ECC itself. The inflammatory response, as well as systemic. microembolisms generated by ECC, induce to some extent a dysfunctional state of the brain, lungs and kidneys, which tends to increase with the aging of the patient. Furthermore, evidence suggests that when ECC can be avoided, the left ventricular function is better preserved, thereby reducing risk of post-operative complications.
As a result, alternate CABG procedures that do not rely on the use of ECC offer distinct advantages.
Recently, minimally invasive surgery, involving a partial sternotomy or mini-thorocotomy, has generated much interest since it removes precisely the need for ECC. This surgery does, however, have its limitations. It is adequate for only one or two coronary bypass grafts. Moreover, it does not provide access to the posterior descending or circumflex arteries, and impairs both the anastomosis and the surgeon's vision due to the limited heart exposure.
These limitations may lead to future, more-invasive surgical interventions through partial or full sternotomy, if “blockages” progress in those arteries which were not accessible via minimally invasive procedures.
Therefore, partial revascularization may lead to re-intervention which not only represents a disadvantage to the patient but a financial burden to the health care system.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a surgical apparatus allowing to perform coronary surgery, in particular coronary artery revascularization, without the need for extra-corporeal circulation.
It is a further object of the invention to provide a surgical apparatus to perform complete revascularization of coronary arteries without the need for extra-corporeal circulation.
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, on a beating heart.
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, enabling grafting on all arteries of the heart and their respective branches, most particularly the right coronary (RC), the posterior descending artery (PDA), the left anterior descending artery (LAD) and diagonals, the branches of the circumflex artery (Cx) namely the obtuse marginal (1 through 4) and the postero-lateral branches.
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, provided with positioning means being capable of being mounted in a plurality of locations on a sternum retractor or any other adequate support.
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, simplifying the grafting process.
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, with reduced costs associated with shorter time of surgery, reduced costs of surgical equipment, reduced surgical staff, significantly reduced risk of medical complications, and shorter hospital recovery stay.
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, that is easy to utilize for surgeons and representing an evolution of current proven practice without the need for long retraining period.
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, enabling surgeons to operate on all patients, especially those not well suited to minimally invasive techniques or well suited to conventional coronary artery bypass grafting (CABG) with extra corporeal circulation (ECC).
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, with a risk reduced procedure for the patient, a cost effective solution to reducing health care expenses, and an ergonomic layout enhancing the efficiency of surgeons.
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, that is ergonomic, easy to deploy, easy to sterilize, and time efficient with respect to the multitude of attachments which might be needed during the course of open chest surgery.
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, which optimizes accessibility to all different arteries requiring grafting irrespective of variations in personal physiology from one patient to another.
It is a further object of the invention to provide a surgical apparatus for performing coronary surgery, in particular coronary artery revascularization, that can be used with known types retractors, as a retrofit arrangement.
Another object of the invention is to provide positioning means for a surgical apparatus, in particular a heart stabilizer for performing coronary surgery, particularly coronary artery revascularization, without the need for extra-corporeal circulation.
Another object of the invention is to provide contacting means for a surgical apparatus, in particular a heart stabilizer for performing coronary surgery, particularly coronary artery revascularization, without the need for extra-corporeal circulation.
Another object of the invention is to provide a sternum retractor for performing coronary surgery, particularly coronary artery revascularization, without the need for extra-corporeal circulation.
As embodied and broadly described herein, the invention provides a surgical apparatus for coronary surgery on a patient comprising contacting means being capable of providing a mechanical force against at least a portion of the patient's coronary organs according to its positioning with regard to said organs, positioning means to set said contacting means in a given substantially stable spatial position and orientation within a given volume, said contacting means being pivotingly connected to a sternum retractor via said positioning means.
This surgical apparatus enables performing coronary surgery, particularly coronary artery revascularization, without the need for extra-corporeal circulation. That is to say, the operation can be realized on a beating heart There is no need to use a cardio-pulmonary machine, which considerably reduces the costs of the operation. Without extra-corporeal circulation, mortality and morbidity rates are also reduced.
The surgery and graft process can be performed by only one surgeon and one assistant, as opposed to standard coronary artery bypass graft surgery which usually requires two surgeons and a perfusionist for ECC.
As embodied and broadly described herein, the invention also provides positioning means for a heart stabilizer for use in coronary surgery, said heart stabilizer comprising contacting means intended to provide a mechanical force against at least a portion of the patient's coronary organs according to its positioning with regard to said organs, said positioning means being intended to set contacting means in a given substantially stable spatial position and orientation within a given volume and being connectable in at least one location to a sternum retractor, said contacting means being connectable to a movable free portion of said positioning means.
The contacting means can therefore be positioned in an almost unlimited number of positions and orientations to facilitate the intervention on any artery. This also brings high flexibility, as any patient, whatever the morphology may be, can be treated. Moreover, the adaptability of the apparatus facilitates the grafting process. For example, the right coronary artery is most accessible when the positioning means are mounted on the rack bar. The left anterior descending artery and diagonal arteries are most accessible when positioning means are mounted in the ending portion of the spreader arms. Access to the circumflex artery and posterior descending artery is enhanced when positioning means are mounted on the right side of the retractor, patient's view.
Preferably, the positioning means comprise a sliding member providing relative movement between said sternum retractor and said positioning means. This provides great flexibility and facilitates the surgical manipulations.
As embodied and broadly described herein, the invention also provides positioning means for a heart stabilizer for use in coronary surgery, said heart stabilizer comprising contacting means intended to provide a mechanical force against at least a portion of the patient's coronary organ according to its positioning with regard to said organs, said positioning means being intended to set contacting means in a given substantially stable spatial position and orientation within a given volume and being connectable in at least one location to a sternum retractor, wherein said positioning means comprise an articulation member for providing displacement of a member connected thereof with at least one degree of freedom, a positioning rod connectable to said articulation member, said contacting means being connectable to said positioning rod.
More specifically, under this preferred embodiment, the positioning means comprise a second articulation member for providing displacement of a member connected thereof, with at least one degree of freedom, said positioning rod being connectable to said second articulation member. The articulation member can advantageously be made of a resilient material.
In a specific example, the articulation member comprises at least one partly spherical member pivotingly maintaining a positioning rod member between two hollow cylindrical bodies. In another specific example, the articulation member comprises at least one partly spherical member pivotingly maintaining positioning rod member between two clamping members.
In another specific example, the “quick-assembly” parts allow the positioning means to be placed in at (east six different orientations with respect to the sternum retractor, and consequently the patients heart: four orientations along the perimeter of the retracted chest cavity, and two cross-corner diagonal orientations. This maximizes the options for optimum accessibility to the target artery. It also provides the surgeon with flexibility during delicate surgical tasks like suturing, as he has access to strategic sections of the chest cavity that are free from all devices.
As embodied and broadly described herein, the invention also provides positioning means for a heart stabilizer for use in coronary surgery, said heart stabilizer comprising contacting means intended to provide a mechanical force against at least a portion of the patient's coronary organs according to its positioning with regard to said organs, said positioning means being intended to set contacting means in a given substantially stable spatial position and orientation within a given volume and being connectable in at least one location to a sternum retractor, wherein said positioning means further comprise an articulation member for providing displacement of a member connected thereof with at least one degree of freedom, a positioning rod connectable to said articulation member, a second articulation member for providing displacement of a second member connected thereof with at least one degree of freedom, a second positioning rod connectable to said second articulation member, said contacting means being connectable to said second positioning rod.
As embodied and broadly described herein, the invention also provides contacting means being capable of providing a mechanical force against at least a portion of the patient's coronary organs according to its positioning with regard to said organs within a given volume and comprising two substantially elongated contacting arms defining therebetween an arterial window.
As embodied and broadly described herein, the invention also provides a sternum retractor for use in coronary artery surgery, comprising: a rack bar extending transversally between the ending portions of a fixed spreader arm and a movable spreader arm, these arms both extending longitudinally in a direction substantially normal with regard to the rack bar, said movable arm being capable of being displaced along the rack bar and said spreader arms being provided with blades, contacting means intended to provide a mechanical force against at least a portion of the patient's coronary organs according to its positioning with regard to said organs, positioning means intended to set contacting means in a given substantially stable spatial position and orientation within a given volume and being connectable in at least one location to a sternum retractor, said contacting means being connectable to a movable free portion of said positioning means.
All interfaces are intended and designed to keep the open chest cavity as ergonomic and accessible as possible, free from all peripheral tubing and connectors. All interfaces, design features and components are easy to sterilize.
The surgical equipment described herein can be used to perform multiple revascularizations on any of the coronary arteries or branches without repositioning the sternum retractor after initial deployment. The interfaces between the positioning means and the retractor are preferably designed to permit retractor spreader arm readjustment without disconnecting the positioning means setup. It can be used to perform multiple revascularizations by surgeons experienced in standard on-pump CABG with minimal training. It also can be used to perform revascularizations for both initial surgeries and reoperative cases.
The surgical equipment described herein provides the surgeon with visibility equal to that of standard CABG. Furthermore, in cases where unforeseen complications develop during surgery, the method described herein is not disadvantaged with the delays and complications associated with conversion from a minimally invasive CABG technique to full open chest surgery in cases. It is also not required for the patient to be placed on single lung ventilation, as is the case in some minimally invasive techniques.
The surgical apparatus described herein reduces the costs associated with standard CABG in particular in the following specific areas:
a cardio-pulmonary machine is not required;
a perfusionist to operate the cardio-pulmonary machine is not required;
less highly trained surgical staff is required to perform the surgery (one surgeon and assistant, compared to two surgeons);
reduced hospital stay is required because ECC is not used;
reduction in frequency of complications and associated costs;
reduction in operating time due to ergonomic design features of apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will further be described, by way of example only, with reference to the accompanying drawings wherein:
FIG. 1A is a perspective view illustrating a first embodiment of the surgical apparatus according to the invention;
FIG. 1B is a perspective view illustrating working volume W and motion degrees of freedom of the surgical apparatus according to the invention;
FIG. 2 is a top view of the embodiment illustrated in FIG. 1A;
FIG. 3 is an exploded view of the first articulation member used in FIG. 1A;
FIG. 4A is an exploded view of FIG. 1;
FIG. 4B is a cut away view of the articulation member illustrated in FIG. 4A;
FIG. 4C is a side elevational view of the knob of articulation member illustrated in FIG. 4B;
FIG. 5A is a perspective view illustrating a second embodiment of a surgical apparatus according to the invention;
FIG. 5B is a perspective view (partly cut away) of the articulation members used in FIG. 5A;
FIG. 6 is a side elevational view of the embodiment illustrated in FIG. 5A;
FIG. 7 is a variant of the embodiment in FIG. 5A;
FIG. 8 is another variant of the embodiment of FIG. 5A;
FIG. 9 is a variant of the embodiments of FIG. 1 A and FIG. 5A;
FIGS. 10A to 10 F are perspective views according to the invention;
FIG. 11 is another embodiment of the surgical apparatus;
FIG. 12 is a perspective view of a sternum retractor variant;
FIGS. 13A to 13 F illustrate examples of several setting possibilities of the positioning members on a sternum retractor, as illustrated on FIG. 12;
FIG. 14 is a perspective view partly exploded and schematically illustrating an example of a retrofit system according to the invention;
FIGS. 15A to 15 F illustrate several examples of support members for retrofit systems according to the invention, as illustrated in FIG. 14;
FIG. 16 is a perspective view illustrating a further embodiment of the surgical apparatus according to the invention, using easy to connect/disconnect articulation members;
FIG. 17 is a fragmentary top view of a sternum retractor according to the invention;
FIGS. 18A to 18 C are examples of variants of the embodiment described in FIG. 5A;
FIGS. 19 and 20 illustrate variants of the embodiment of FIG. 1A;
FIGS. 21A to 21 D illustrate further variants of the embodiment of FIG. 1;
FIG. 22A is a perspective view of a sternum retractor illustrated in FIG. 1A;
FIGS. 22B-22F illustrate examples of rail profiles used on a sternum retractor illustrated in FIG. 22A;
FIGS. 23A and 23B illustrate perspective views of the surgical apparatus according to the invention, in use during a coronary artery revascularization;
FIG. 24 illustrates a push type configuration according to the invention;
FIG. 25 illustrates a pull type configuration according to the invention;
FIGS. 26 to 29 illustrate perspective views of contacting means according to the invention;
FIGS. 30A to 30 G illustrate variants of contacting means provided with different types of attachment means;
FIGS. 31A to 31 F illustrate variants of contacting means provided with different types of textures;
FIG. 32 illustrates a variant of a positioning rod.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The surgical apparatus according to the invention is provided to be used with a sternum retractor. Single purpose sternum retractors, which only serve to retract the patient's sternum and ribcage, are well known in the art. They are mainly used for retracting the mediastinum in order to perform coronary artery revasculatizations, heart valve replacement, and other cardiac interventions.
Such a sternum retractor 1 comprises a rack bar 2 extending transversally, a fixed spreader arm 3 , and a moveable spreader arm 4 . Both arms extend longitudinally in a direction substantially normal with regard to the rack bar. The movable arm 4 can be displaced along the rack bar, using a crank 5 activated by a pinion mechanism (not shown) through shaft 6 . Two blades 7 are provided underneath the spreader arms.
This invention introduces an improved retractor specifically designed to provide attachment interfaces for a variety of positioning means and any other equipment used during the course of open chest cardiac surgery.
In broad terms, the surgical procedure related to this invention consists of:
1. Full or partial sternotomy;
2. Isolation and removal of either internal saphenous vein(s) or of internal thoracic artery(ies);
3. Strategic positioning and manipulation of beating heart with regard to the artery to be bypassed;
4. Locally immobilizing and stabilizing the portion of the beating heart around the grafting site;
5. “Pinching” the target artery upstream and downstream of occluded site to restrict blood flow during grafting;
6. Grafting of bypass veins and/or arteries;
7. Verifying blood flow through newly grafted bypass artery;
8. Draining of chest cavity;
9. Closing of chest cavity.
In the course of an operation, a surgeon needs to perform certain tasks within the volume defined by the rack bar 2 , the arms 3 and 4 and the chest cavity, such as reaching the target arteria, suturing, etc. The volume in which the surgeon needs to perform these different tasks, will be called herein the working volume W. This volume also comprises a buffer zone extending beyond the perimeter of open chest cavity (see FIG. 1 B). The present invention provides positioning means 20 allowing the surgeon or an assistant to place and secure a specific surgical instrument, namely the contacting means 30 , within this working volume, to perform revascularizations on a beating heart more easily, quickly and effectively. The above mentioned type of retractor is preferably used to set the positioning means. However, other retractor types, for example chest retractor or thoracic retractor, or other supports, for example a bed or a crane, can also be used.
FIG. 1A illustrates a first embodiment in which the positioning means comprise a unique articulation member. FIG. 1B schematically depicts the flexibility and versatility of the surgical apparatus through the motion degrees of freedom listed below:
S displacement of articulation member 50 along rails 40 of retractor;
R 1 axial displacement along centerline of first positioning rod 60 through articulation member 50 ;
R 2 displacement along centerline of second positioning rod 70 through articulation member 80 ;
α rotation about centerline of articulation member assembly 50 ;
A 1 angular displacement through rotation α;
β angle between centerline of first positioning rod 60 and centerline of articulation member assembly 50 ;
P 1 displacement along z axis achieved through rotation β;
ε angle between first positioning rod 60 and second positioning rod 70 in the plane formed by their two axes;
φ angular rotation of second positioning rod 70 in the plane normal to the centerline of first positioning rod 60 ;
A 2 angular displacement of contacting means 30 about the centerline of second positioning rod 70 .
The fixed spreader arm and movable spreader arm are preferably provided with rails 40 , disposed axially along said arms, for example on top of blades 7 . Any known type of rail can be used. FIGS. 22A to 22 F illustrate various examples of rail profiles. Other types can also be used like, for example, a rod type rail.
A first articulation member 50 is slidingly and pivotingly engaged in said rails. This first articulation member is easily removable from the rails and can therefore be placed on any of the rails. It can also be set in any axial position on said rails or, alternatively on the rack bar slot as shown on FIG. 17 . This first articulation member also serves as a support for a first positioning rod 60 . The rod 60 and the articulation member 50 are arranged to allow the free end portion of the rod to be placed in any position within said working volume W. This rod 60 can be easily displaced first with the sliding motion S of the articulation member 50 along any of said rails 40 , corresponding to a displacement along the Y axis. Secondly, with an angular motion A 1 of the articulation member 50 about its own centerline, the rod 60 can be placed along a given angle α. Thirdly, the rod 60 can be shifted axially (R 1 ) through the member 50 in order to get closer or farther from said member. Finally, the member 50 can also provide a first height positioning P 1 , allowing the rod 60 to pivot vertically, to reach a given β angle.
The ending portion of this first positioning rod within the working volume is provided with a second articulation member 80 . This second articulation member mainly serves as a holding member for a second positioning rod 70 . One ending portion of this second positioning rod is provided with a contacting means 30 . This second articulation member allows advantageously four types of displacements; first, an axial sliding motion R 2 to allow the positioning of the contacting means 30 along the centerline axis of rod 70 , within the working volume W; second, an angular displacement A 2 of a contacting means 30 about the centerline of positioning rod 70 ; third, an angular orientation of the second positioning rod 70 with respect to first positioning rod 60 through angle ε; fourth, an angular rotation φ of the second positioning rod 70 in a plane normal to the centerline of the first positioning rod 60 . According to a preferred variant, member 50 provides a coarse adjustment whereas member 80 provides a fine adjustment.
In this way, the contacting means can be placed very accurately in practically any position and orientation within said volume W. The position is preferably obtained with displacement S, R 1 , A 1 , P 1 , and R 2 . The orientation of the contacting means is mainly achieved with the displacement A 1 , A 2 , P 1 , φ and ε. Of course, many variants of the invention can be provided, only by adding or removing a given articulation or displacement possibility. For example, the first transmission member 50 could be provided so that rod 60 rotates along its own axis, or contacting means 30 could be provided with a pivot at its junction with rod 70 , etc. Furthermore, the positioning means extends advantageously beyond the perimeter of the open chest cavity.
Different types of articulations may be used for the first articulation member 50 and second articulation member 80 . For example, known types of articulations like resilient articulations or spherical bearing articulations, etc, may be used without departing from the spirit of the invention. The articulations used with the embodiment illustrated in FIG. 1A are shown in details in FIGS. 3 and 4A.
FIG. 3 illustrates an exploded view of an example of a first articulation member, such as the one used in the embodiment of FIG. 1, with reference 50 . A hollow cylindrical body 55 is provided along its longitudinal wall with two opposite oval windows 551 . A top cover 552 on the upper end is provided with a central aperture 553 . A bottom hollow cylindrical member 52 is provided with two opposite lateral openings 522 . The front portion is open to cooperate with other components. The inner top and bottom portions are shaped with opposite concave profiles 524 and 523 . Two opposite semi-sphere like adaptors 56 and 54 are provided with a cylindrical hollow. A top hollow cylindrical member 53 is provided with lateral openings corresponding susbtantially to those of the hollow cylindrical member 52 so that it can cooperate with the bottom member 52 . On top of member 53 a screw member 533 is provided. The inner bottom portion is shaped with a concave profile corresponding to the lower semi-sphere like adaptor. The positioning rod is engaged through the hollow portion of the two semi-sphere like adaptors to create an assembly.
This assembly is placed in the cavity formed by the cooperating members 52 and 53 . The upper and lower adaptors 56 and 54 cooperate respectively with the concave inner portion 524 and the concave inner portion 532 . This allows easy pivoting of the rod, not only vertically, but also laterally. All these components are maintained together in the cylindrical body 55 . The rod extends through windows 551 . Screw member 533 extends through aperture 553 and cooperates with set screw 51 . A flange 521 provided at the bottom of member 52 allows easy engagement of the assembly within rails 40 or any attachment means, that do not necessarily provide sliding possibilities.
When the set screw is loose, cooperating components allow pivoting movement of the rod and eventually a rotational movement of the latter along its own axis. When the screw is tightened, a compression stress is generated with the inner portion 532 of member 53 pressing against adaptors 54 and 56 and inner portion 524 of member 52 . A tight fit is therefore created into the cylinder body 55 . This mechanical stress avoids any relative movement of the components. Moreover, the body 55 is pressed against the spreader arm or rail or the like on which it is engaged, creating a locking effect. The articulation is then slidingly and pivotingly locked.
FIGS. 4A to 4 C illustrate views of an example of an articulation member such as the one used in the embodiment of FIG. 1, with reference 80 . The figures shows two elongated and opposite clamping members 82 , each one provided with an inner seat portion 83 to cooperate with a ball end 61 on rod 60 , and an aperture 84 for engagement of set screw member 81 . An inner annular groove 85 is also provided for engagement of the second positioning rod 70 . The groove 85 is arranged in a direction substantially perpendicular with regard to the longitudinal axis of the clamping members 82 . A preload spring 62 ensures that the members 82 and 61 are properly maintained as an assembly. Moreover, the two members 82 are tightened together with screw member 81 .
They provide a housing for ball end 61 and a portion of rod 70 . Depending on the tightening of screw member 81 , the articulation maintains the rods 60 and 70 in a locked or mobile arrangement. The angular movements ε and φ of positioning rod 70 are achieved through relative movement of members 82 with respect to 61 . Screw member 81 is preferably provided with an arrangement that gives the possibility to adjust the positioning by using either side of screw member 81 . This feature is advantageous because the working area W is in general very small and the access to a specific side of the screw member 81 is limited for the surgeon.
FIGS. 4B and 4C illustrate such an arrangement. Left side knob 801 extends longitudinally with threaded rod 802 through the left clamping member 82 and is screwed to the right clamping member which is provided with inner thread 806 . The end portion of rod 802 and the corresponding inner portion of knob 801 are shaped with two opposite flat surfaces 803 , allowing torque transmission from the knob to the rod. Locking balls 805 provided in a circular groove in the inner portion of right side knob and maintained with a set screw 804 keep the components together. With such an arrangement, the surgeon tightens or untightens the two clamping members 82 by actuating any of the two knobs 801 . The rotational movement allows inner threads 806 to create a translational movement of corresponding right clamping member 82 , that will therefore get closer or farther from the other facing clamping member, resulting in a tightening and loosing effect.
With these various adjustment possibilities, the contacting means 30 can easily be positioned very accurately with regard to the target arteria of the heart. Moreover, according to a variant, a coarse adjustment is performed with one articulation member (for instance the first articulation member 50 ) and a fine adjustment is achieved with the other articulation member (for instance the second articulation member 80 ).
FIG. 5A illustrates a second preferred embodiment according to the invention. The sternum retractor arrangement is similar to the previously described one. However, the positioning means 20 slightly differs from the first embodiment. According to this second embodiment, two articulation members 150 and 250 are provided. These articulations may be in many aspects similar to those described above.
FIG. 5B is a perspective view, partly cut away, illustrating the articulation members 150 and 250 , and the first positioning rod 60 . One articulation member is arranged to allow a sliding movement of the positioning rod through it. An inner rod member 151 is provided with a transversal hole 152 seated in a hollow cylindrical body 153 , with two open ends 156 . A threaded portion 155 extends upwardly beyond the body for engagement with a set screw 51 . The bottom portion extends downwardly beyond the body and is provided with a flange 154 for engagement with rails 40 .
When set screw 51 is tightened, a tensile strain causes the bottom edge of the cylinder body 153 to press against the edge of windows 156 through which rod 60 extends. The same strain causes the bottom edge of the cylinder body 153 and the upper edge of flange 154 to press against the rails 40 in opposite directions. The assembly is therefore locked. When set screw is loose, no strain acts against the components. The rod can slide through the articulation and the articulation is capable of sliding and/or pivoting along the rails. The opposite articulation member 250 can be similar to the one described above or can be simplified by having rod 60 in a fixed configuration on relative to articulation member 250 . This can be achieved with an assembly comprising an inner rod member 151 and a cylinder body 153 similar to those previously described. The rod is then attached to the cylinder body. This allows sliding and/or pivoting movement of the articulation member 250 along the rail 40 . One or both articulations can be displaced along the rails or placed on discrete locations on the retractor, if no rails are provided.
The articulations can be set in a symetric disposition, with each articulation having an identical position with respect to the rack bar. They can also be arranged in asymetrical disposition, on the same arm, etc., as shown in FIG. 13 . The translational motion of the rod 60 through the articulation 150 remains an advantageous feature of this embodiment. For example, if during surgery, the sternum retractor opening must be modified, the rod 60 can slide through one of the articulations (for instance, the articulation engaged in the movable spreader arm), allowing the second positioning rod 70 and the contacting means 30 to remain in substantially the same position with regard to the heart This allows efficient readjustment of the surgical apparatus without complete disassembly of the positioning means.
Of course, with such an embodiment, the second articulation member 80 is slightly different from the one described above (shown in FIG. 2 ). This second articulation member allows advantageously five types of displacements: first, an axial sliding motion R 3 to allow the positioning of the second rod 70 along the centerline axis of rod 60 ; second, an axial sliding motion R 4 to allow the positioning of the second rod 70 through articulation member 80 ; third, an angular rotation of the contacting means 30 about the rod 70 axis; fourth, in the plane defined by the axes of the rods 60 and 70 , angular orientation of said rods; fifth, angular rotation of rod 70 around the axis of rod 60 . The set screw 81 allows for easy setting and readjustment of rod 70 with respect to rod 60 . The contacting means 30 is provided at the end portion of the rod 70 , within the working volume W. The rails 40 can eventually be extended with a separate rail portion placed on the rack bar.
FIG. 6 illustrates a transversal view of this embodiment. From this drawing, it can be seen that the contacting means 30 has a very specific shape. In this particular embodiment, the slightly curved profile allows the positioning of the contacting means with regard to the heart, so that the heart is placed in the concave side of the contacting means. With such an arrangement, the positioning means is capable of producing a pulling force against the heart. These features will be described thoroughly herein below.
FIG. 7 shows a variant of the previous embodiment According to this variant, the rod 60 is bent to form a U-shape with regard to the two articulation members. Such a shape gives additional adjustment possibilities to position the contacting means with regard to the heart.
FIG. 8 illustrates a further variant of the embodiment illustrated in FIG. 5A According to this variant, the rod 60 is shaped in the form of a circular arc. The letter “R” on the figure illustrates the radius of the corresponding virtual circle. Once again, this particular shape allows a very accurate positioning of the contacting means with regard to the target artery.
FIG. 9 illustrates a top view of a variant whereas one or both blades 7 are rotatably mounted on the retractor arms. The remaining features being similar to those already described are not illustrated. This variant is advantageous while it gives a possibility to adapt the blade arrangement to the sternum of the patient to be treated, without affecting the remaining components of the apparatus. For example, one blade could be installed slightly rotated with regard to the other one.
According to the invention, the surgical apparatus advantageously provides anchoring means disposed in discrete positions along the arms 3 and 4 or possibly at any other location on the device. FIGS. 10A through F illustrate different variants of such anchoring means. These anchoring means serve many purposes, for example to attach “in-process” sutures that are strategically used to position tissue or organs away from primary surgical operation; to attach Silastic™ rubber bands, or silicon loops, utilized during myocardial mobilization, or pericardial traction; to attach sutures or silicon rubber loops, serving to “brace” the positioning means rod in significantly overhung orientations with respect to the retractor; and to secure any peripheral equipment used during operation to keep uncluttered chest cavity during surgery. These anchoring means are intended to allow a quick assembly and disassembly of the wire, suture, Silastic™ rubber bands, etc.
FIG. 10A shows an example of an arrangement with such means preferably disposed along a rail. FIG. 10B illustrates an example of an anchoring means with a “V” shaped aperture in which the wire can be inserted very quickly. At the base of the “V”, a slightly enlarged opening provides a seat to lock the wire. Each side of the “V” shape is provided with a blade, retaining the wire that is wounded-up around the body of the means.
FIG. 10C illustrates a different shape of anchoring means with a nail like head. FIG. 10D illustrates another variant which is shaped like an inclined rod. FIG. 10E illustrates anchoring means consisting of T-shape apertures provided in the spreader arm or in any other location of the surgical apparatus. FIG. 10F illustrates a pin type anchoring means. As illustrated the pin is advantageously slidingly arranged.
FIG. 11 illustrates a third embodiment of a heart stabilizer according to the invention. This simplified embodiment uses a standard sternum retractor. The positioning means 20 are connected to the sternum retractor through an articulation member 250 attachable to the rack bar of the retractor. According to the embodiment illustrated in FIG. 11, the articulation member consists of a “U” shaped sliding member, laterally inserted into the rack bar 2 . A set screw 251 allows to lock or unlock the articulation member on the rack bar. The unlocked position allows the surgeon to slide the assembly on either side of the bar. It also permits him to slide the first positioning rod 60 axially. It also allows him to slidingly and pivotingly set rod 60 with respect to rack bar 2 through articulation member 250 . The set screw 251 allows an easy longitudinally positioning of the assembly.
The axial positioning can be set either with the articulation member through set screw 251 or with the second articulation member 180 through a set screw 181 , though this second articulation member mainly serves to angularly position a second positioning rod 70 . This angular position can be easily modified as the two clamps are pivotally connected together. The contacting member 30 is provided at the ending portion of this rod located within the working volume W.
The characteristics related to the rods and second articulation member are similar to the second embodiment illustrated in FIG. 5 A and described above. This very simple attachment means allows the use of a heart stabilizer according to the invention with an existing sternum retractor. Such a “retro-fit” is very advantageous while most hospitals or clinics are already equipped with retractors. This existing equipment can thus be updated. This embodiment can also feature quick connect/disconnect articulations, as described below.
FIGS. 12 to 15 illustrate a further embodiment particularly suited to retrofit applications but not exclusively reserved for them. A known type sternum retractor 1 may be used. According to the invention, the retractor is easily modified to provide attachment means, such as for example attachment holes 8 preferably located by each end portion of the spreader arms and/or arranged in discrete locations along the retractor.
Different types of stabilizer can then be used to complete the arrangement. For example, a stabilizer with positioning means such as described above for the embodiments of FIG. 1A or 5 A The attachment means could serve to attach rails, that for example are similar to those of FIG. 1 or 5 , or an assembly without rails, the articulation member being attachable to any of the retractor holes 8 .
FIGS. 14, 15 , and 16 illustrate examples of attachments to the retractor. FIG. 14 shows an example with two supports onto which the rail is attached. The rail could be of a rod type, as shown in FIG. 14, or sliding type as shown in FIG. 1A, or any other appropriate type. FIG. 15A illustrates an example of a support provided with a rubber boot 101 , a rod 102 , and a locking system actuated by a cam-lock. The system is illustrated in the locked mode, in which the rubber expansion fills the surrounding cavity creating thus a locking effect.
FIG. 15B illustrates a magnetic type of support which offers the advantage to avoid the holes on the retractor in the previous examples. The holes are replaced by a magnetic insert 111 , on which the magnetic support can be placed. The magnetic support 110 preferably comprises a layer arrangement with alternate layers of magnetic 112 and non-magnetic 113 alloy. A portion of the layer assembly is transversally movable with regard to the remaining portion. Buttons 114 allow the surgeon or user to set the assembly onto the retractor by placing the two portions in magnetized or unmagnetized positions.
FIG. 15C illustrates a threaded type support which can easily be set using conventional tooling. FIG. 15D illustrates a spring loaded ball bearing type support adjustable in a locked or unlocked position depending on the lateral position of the balls. The figure illustrates the locked mode, in which the balls are projected and maintained in a locking arrangement by cooperating with a grooved portion of the retractor. In the unlocked position, the groove is free and the support can be removed. FIG. 15E illustrates a hydraulic deployment arrangement A set screw acts on a piston arrangement which can cause a lateral flexible membrane expansion or retraction under the effect of an inner oil pressure increase or decrease respectively. FIG. 15F illustrates a mechanical wedge type support.
The above variants are only examples of attachment means that could be provided. Other types of variants may be used, without departing from the spirit of the invention.
According to the invention, the positioning means could be positioned at least in six different orientations with respect to the sternum retractor, and consequently the patient's heart (see FIGS. 13A to 13 E illustrating examples of rail configuration): four orientations along the perimeter of the retracted chest cavity, and two cross-corner diagonal orientations. This maximizes the options for optimum accessibility to the target artery. Of course, according to the respective longitudinal position of the articulations along the arms, a plurality of other positions is also possible. Furthermore, if two rails are used, the possibilities will still be increased.
FIG. 16 shows a variant with easy to connect/disconnect positioning means. Such a variant could be used with any embodiment, with or without rails. A resilient dip assembly 300 of known type could be provided. Such an arrangement enables the surgeon to place the contacting means with more flexibility and allows an easier access to the working volume, which is in general a small volume, difficult to access as many complex instruments obstruct the cavity. This embodiment allows easy access without having to proceed to many adjustments; these adjustments are advantageously performed after the contacting means are well placed. The figure also illustrates an example of rod type rails on which an annular articulation can be slidingly placed. The quick assembly/disassembly function can also be achieved via variety of interfaces (cam-type locking devices, toggle devices, screw type devices, mechanical magnets, etc.).
FIG. 17 shows a variant in which the positioning means, and namely the articulation member, are attached to the sternum retractor via a slot provided on the rack bar. Such a slot can be realized on an existing retractor, resulting in a retrofit arrangement. It can also be provided on a retractor specifically as per the invention.
FIGS. 18A to 18 C ilustrate a variant where the articulation members 650 are bent in such a way to place the rod member 60 laterally distant from the sternum retractor 1 . With such an arrangement, the working area is of easy access and with enhanced ergonomy.
FIGS. 19 and 20 show variants of the embodiment previously described and illustrated in FIG. 1A The articulation members and rods of the embodiment of FIG. 1A are replaced by known-type arms capable of providing rotation, pivoting and translational motions or the like. These arms types are similar to those encountered in desk lamps. These variants are advantageously simple to manufacture, quick and easy to adjust. Other variants offering similarities to these ones can also be provided, sometimes with less positioning capabilities, for example without rotation, without pivoting movement, etc.
FIGS. 21A to 21 D illustrate variants of shapes for the positioning rods. Shapes in a straight line, curved, elbowed or double elbowed, etc. These are only examples of an almost unlimited type of shapes that can be used without departing from the spirit of the invention.
FIGS. 22A and 22F illustrate examples of different shapes of rails that can be used to provide the sliding movement of the positioning means: rectangular, dovetail, etc. These are only examples of an almost unlimited type of shapes that can be used without departing from the spirit of the invention.
FIGS. 23A and 23B illustrate the contacting means 30 when placed against the heart surface. Two elongated contacting arms 31 defining therebetween an arterial window 32 are provided. The two arms are preferably substantially parallel and the slot defined by their inner edge is used as an arterial window. That is to say that the target artery TA will be aligned between these two arms when the contacting means is adequately placed. The arms are shaped to be capable to press against the heart surface HS immediately surrounding the target artery. In this way, the target artery becomes easily accessible for the surgery purpose. As a result, the heart stabilizer locally prevents the heart from moving around the target artery, allowing thus direct coronary bypass surgery on a beating heart. In areas where the arteries are incrusted in the heart surface, the contacting arms provide a way to raise the target artery through the arterial window, thereby increasing access for the purpose of the surgery.
This aspect of the invention can be clearly seen in FIG. 23 B. The target artery TA is engaged between the arms 31 . The surgeon can thus advantageously attach the Silastic™ wire SL to the portions of the target artery that are upstream and downstream of the grafting site. This provides a very efficient way of restricting the blood flow. The surgeon can then cut the artery and realize the grafting process. Attachment means 310 are preferably provided on the non-contacting surface side in order to set the Silastic™ wire in an optimum position. For example, slotted walls can be provided on the contacting arms 31 . These attachment means 310 are spaced sufficiently apart on said contacting arms to allow the grafting process. These attachment means can eventually be adjustable, for example axially with lard to the arms and/or angularly.
The angle of the attachment means 310 with respect to the contact arm 31 can be determined to coincide with the angle of the Silastic™ wire with respect to said arm as it wraps around the target artery. Furthermore, the walls or the like are preferably capable of being oriented so that the wire penetrates in a substantially normal direction with regard to the walls plane, that is to say a preferred angle γ (see FIG. 30A) between 25 and 80 degrees.
FIGS. 30B to 30 G illustrate variants provided with attachment means 310 of different profiles and shapes, respectively “slotted blade type”, “clip type”, “spring type”, “slotted hemisphere type”, “hanger type”, and “plate-like type”. These examples clearly illustrate that the Silastic™, siliconed rubber, silicone elastomer or elastic wire (or other type of wire) can be attached by a plurality of attachment means types.
In order to facilitate the surgery, it is preferable to first set the contacting means against the heart surface in the required position to free the target artery and secondly to secure the contacting means and positioning means assembly to the sternum retractor. To remove the assembly, it is preferable to first disengage the contacting means from the positioning means, thereby easing the separation of the contacting means from the heart surface and minimizing the risk of damage to the newly sutured bypass vessel. Otherwise, the positioning means could also be disengaged first form the retractor, to allow easy separation of the contacting means from the heart surface. In all embodiments, open ended articulation means and/or clamps for the second positioning rod help achieve this quickly and effectively (see FIG. 16 ).
The profile characteristics of the contacting means are very important. For example, as shown in FIG. 23B, the ending portion of the arms 31 is preferably curved. The arms are advantageously provided with a ski-like shape with the tip portion oriented to be away from the heart surface to prevent damage during involuntary contact, avoiding trauma to the heart surface.
FIGS. 24 and 25 illustrate two “families” of contacting means. These families originate from the position of the contacting means with regard to the heart during the surgery and/or the type of force resulting from this position. FIG. 24 shows a “push type” arrangement, whereas FIG. 25 shows a “pull type” arrangement. From these figures, it can easily be seen that the positioning means plus contacting means assembly provides respectively a pushing force (see also FIGS. 23A and 23B) and a pulling force (see also FIG. 6 ). The “push type” and “pull type” are prefered for use with the anterior and posterior arteries respectively. In all embodiments, the motion degrees of freedom of the second articulation means provide the adaptability to cater for push and pull arrangements in a manner to maximize ergonomics of surgery (FIGS. 24 and 25 ).
The contacting means profile is preferably adapted in function of these two families. FIGS. 26, 27 and 28 show examples of “push type” profiles. The attachment means 310 are then provided on the upper portion of the arms 31 . The illustrated example in FIG. 26 is advantageously of oval shape. This facilitates the access to certain arteries that would otherwise be difficult to reach.
Many other profiles are advantageously provided, each one of them matching with a specific area of the heart. FIGS. 27 and 28 illustrate further examples with spoon-like profiles: FIG. 27 with standard spoon configuration (convex contact) and FIG. 28 with concave contact. Adapted profiles are preferable for maximum surface coverage, thereby minimizing heart trauma. Moreover, the interface surface with the beating heart is optimized to maximize stability while minimizing risk of damage to the heart.
FIGS. 29A and 29B show a variant of “pull type” arrangement, in which a given angle is provided between the positioning rod and the contacting means.
FIGS. 31A to 31 F show variants of the contacting means with textured surfaces favoring adherence between the arms 31 and the heart surface, to ensure minimum slip with regard to the heart tissue for example caused by the heart pulsation. Various types of textures can be provided, like for example, (from FIGS. 31A to 31 F respectively) with grooves, with dimples/pedestals, with holes, with perimeter fence, with jagged outer contour, with covalently bonded surface treatment, etc. This helps to prevent “skidding” or “slipping” on either side of target artery during grafting. The contacting means are provided to be in relation with the cardiac organs, in particular the heart. The terms “cardiac organs” comprise the heart, but also the surrounding vessels and tissues, in particular the mediastinum, the pericardium, the thymus; the area between two lungs, etc.
To simplify the surgeon's task and to free the cavity for better ergonomics, the positioning rods may also provide different features, like holes or grooves, or the like.
FIG. 32 illustrates an example in which grooves and holes are used as anchoring points. Those features can also be used with Silastic™ wire, suturing wire, suturing silk, silicon loops or the like inserted through said holes and/or said grooves, and attached to anchoring means on the sternum retractor to brace and maintain the assembly as rigidly as possible.
The different parts and components of the present invention can be manufactured from either a biocompatible plastic, for example medical grade ABS, for single use, or in surgical stainless steel or any other biocompatible sterilizable material to allow for repeat usage.
The above description of the preferred embodiments should not be interpreted in any limiting manner since variations and refinements are possible without departing from the spirit of the invention. | An articulation member for use in a surgical apparatus is provided. The articulation member includes a fitting for mounting to a support structure, a socket for receiving an arm of a surgical tool and a clamp moveable between a loosened position and a tightened position. In the loosened position the clamp permits movement between the fitting and the support structure, and permits rotation of the socket. In the tightened position, the clamp secures the fitting and the arm relative to the support structure. | 0 |
REFERENCE TO RELATED APPLICATION
This application is a Continuation-In-Part of my application Ser. No. 06/773,871, filed Sept. 9, 1985, titled SECTIONALIZED CONTOUR RAZOR, now abandoned.
SUMMARY OF THE INVENTION
The present invention relates to a flexible razor system for shaving large, rounded or variably contoured shaving surfaces such as legs, arms, thighs, underarms and head. Much like trying to peel an apple with a straight-edged knife, the conventional straight-edged razor takes relatively many strokes to accomplish a thorough shave on a rounded or contoured surface because of the relatively short contact length between the straight-edged razor and a curved shaving surface. This makes the shaving of any large, rounded or contoured body surface time-consuming and tedious.
The present invention teaches the use of a sectionalized razor system in which a plurality of rigid, individual blade-housings are used. Said razor system is adapted to automatically flex in order to closely conform to the contoured surface being shaved. The use of a plurality of individual blade-housings achieves a very wide shaving swath on any rounded or contoured surface that is far wider than it is possible to achieve with a straight-edged razor. Additionally, the wider shaving swath provided by the present invention requires far fewer strokes than a conventional razor in order to accomplish thorough shaving of rounded or variably contoured surfaces. Also, there is less likelihood of inadvertently missing ribbons of shaving surface because of the much longer cutting swath of the razor system versus that of a conventional straight-edged razor.
A primary object of this invention is to provide a flexible sectionalized razor system that, in any single stroke, is able to produce a dramatically wider, uniform shaving swath on any rounded or contoured surface than any other prior art razor. This much wider shaving swath greatly reduces the time necessary to shave large, contoured areas of the body because fewer strokes are required.
A second object of this invention is to provide a flexible sectionalized razor system using a plurality of individual blade-housings in which each of said blade-housings is free to tilt or move in order to closely follow its own local shaving surface contour.
A third object of this invention is to provide a way of achieving essentially equal contact forces for each of said plurality of blade-housings against any rounded or contoured shaving surface. This is very important because too much force on any one of said blade-housings will cut or abrade the skin being shaved, while too little force will leave the skin improperly shaved. The configurations shown in the present inventions inherently make all the forces on said plurality of blade-housings approximately equal. The razor system user may, therefore, select and control any desired overall shaving force without disturbing the inherent equality of each individual blade-housing's force against the shaving surface.
As a result, the razor system provides a uniform and thorough shaving of any rounded or contoured shaving surface.
Various other features and advantages of the invention will be brought out in the balance of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a razor system embodying the present invention.
FIG. 2 is an elevational view of a portion of the embodiment shown in FIG. 1.
FIG. 3 is a sectional view on the line 3--3 of FIG. 2.
FIG. 4 is a sectional view on the line 4--4 of FIG. 2.
FIG. 5 is a side view of a portion of the embodiment shown in FIG. 1.
FIG. 6 is a perspective view of a handheld embodiment of the invention employing finger loops.
FIG. 7 is a perspective view of an alternative handheld embodiment of this invention employing resilient plastic foam.
FIG. 8 is a perspective view of another embodiment of this invention embodying a flexible strap and a long continuous slab of resilient plastic foam.
FIG. 9 is a perspective view, partially in section, of an alternative embodiment of this invention employing a flexible strap and a plurality of individual resilient plastic foam sections.
FIG. 10 shows a view, partially in section, on line 10--10 of the embodiment shown in FIG. 8.
FIG. 11 shows an embodiment of this invention employing two rows of angularly positioned, overlapping blade-housings.
FIG. 12 shows a perspective view of another embodiment of this invention employing resilient foam attached to a rigid housing.
FIG. 13 is a sectional view of an alternative dual-bladed housing variation, for use in any of the embodiments shown in this invention.
FIG. 14 is a perspective view, partially in section, of an alternative embodiment to that shown in FIG. 15, employing flexible and resilient foam sections acting as omnidirectional swivels.
FIG. 15 is a perspective view of another embodiment of this invention employing long, resilient ribs.
FIG. 16 is a perspective view, partially in section, of an alternative embodiment to that shown in FIG. 15, employing ball-joint swivels.
FIG. 17 is a view on line 17--17, partially in section, of the embodiment shown in FIG. 15.
FIG. 18 is an elevational view of a portion of the embodiment of FIG. 15.
FIG. 19 is an elevational view showing a hingeless alternative embodiment of the blade housings that are shown in FIG. 18.
FIG. 20 is an elevational view of another embodiment of this invention showing a single row of angularly positioned, overlapping blade-housings.
FIG. 21 is a perspective view of an embodiment of this invention employing spring means attached to a rigid housing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of this invention is shown in FIGS. 1 through 5. In this embodiment, the blade-housings 12 are injection-molded or mechanically attached to two plastic straps 20 and 22 containing v-grooved hinges 53. Swivel brackets 51 are hinged 54 to the ends of razor housing straps 20 and 22 in order to allow these straps to flex about swivel brackets 51 during shaving. While strap 22 contains only blade-housings 12, strap 20 contains blade-housings 12 plus two "dummy" housings 71 and 72. Said "dummy" housings act to fill in the resulting spaces that are created by the fact that the blade-housings 12 in FIG. 3 are staggered with respect to those in FIG. 4. This keeps the ends of strap 20 from buckling during shaving.
The front row gaps 56 between blade-housings 12 shown in FIG. 4 cause unshaved ribbons during shaving. These unshaved ribbons are shaved by the staggered blade-housings 12 of the rear row shown in FIG. 3.
FIG. 1 shows how handle 55 swivels about blade-housings 12 by means of swivels 59, which are attached to swivel brackets 51 by pins 60. This allows handle 55 to swivel about pins 60 via ribs 57 during shaving. To shave a concave surface, such as the underarms, the user simply grasps handle 55 and pushes straps 20 and 22 outward as shown by arrows 61 to position 65 with a forefinger and/or an index finger.
A lady may shave her legs while standing erect by employing a long extension-handle (not shown) attached to the end of handle 55 of FIGS. 1, 8 or 15. This approach is only practical with the very wide, contour-hugging swath of this invention, while the narrow swath and the sliding askew tendency of a conventional straight-edged razor would make said extension-handle impractical.
Another embodiment of this invention is shown in FIG. 6 as a handheld, compact version. Blade-housings 12 and plastic straps 20 and 22 are similar to those in FIG. 1. However, rather than employing a single handle 55, two loops 75 which comprise handle and rib means in this embodiment are attached to brackets 51 via pins 60. This allows the user to put a thumb through one loop and a little finger through the other loop while grasping the tops of the blade-housings 12 with the remaining fingers. The user's fingers act as additional rib means and provide the necessary forces to keep all blade-housings 12 in contact with a contoured surface during shaving.
Another handheld, compact embodiment of this invention is shown in FIG. 7. This embodiment employs blade-housings 12 in a similar manner to that shown in FIG. 6. However, loops 75, straps 20 and 22 have been eliminated. Polyurethane foam 27 is added and is glued to the tops of blade-housings 12. Optionally, a flexible, resilient cover 58 may be added and then glued to the top of said foam 27. The user simply cups this handheld version in the palm of her hand and proceeds to shave. The palm's pressure causes polyurethane foam 27 to compress and thus evenly distributes the force to all parts of blade-housings 12. This enables uniform shaving of all contoured shaving surfaces.
Another embodiment of this invention is shown in FIG. 8. This embodiment is similar to that shown in FIG. 1. However, FIG. 8 shows a wide flexible thin strap 15 glued to a long slab of polyurethane foam 27. Each individual blade-housing 68 of the group of blade-housings 12 is glued to said polyurethane foam 27 which is very pliant and resilient. This characteristic enables individual blade-housings 68 to tilt in any direction that is dictated by the contour of the shaving surface 16, virtually independent of the tilting of any of the other blade-housings 68. Holes 31 enable shavings and lather to escape without clogging.
FIG. 10 shows a view on line 10--10 of the embodiment shown in FIG. 8. Here, one can better see the exit path of the shavings and lather. After the hairs are cut by blade 7 as it shaves the surface 16, the shavings and lather pass up through a hole 18 in the roof of blade-housing 68 and then through a hole 48 in foam 27 and finally through exit hole 31 in flexible cover 15.
An alternative embodiment of this invention to that shown in FIG. 8 is shown in FIG. 9. Here, the long slab of polyurethane foam 27 shown in FIG. 8 has been cut into individual sections 37 for each blade-housing 68. This allows the blade-housings to tilt even further and more easily as compared to employing the long foam slab 27 shown in FIG. 8.
FIG. 11 shows an embodiment of this invention showing an alternative arrangement of blade-housings 12 to that shown in FIG. 8. Here, blade-housings 12 overlap and therefore, leave no unshaved ribbons. Additionally, said blade-housings 12 are inclined to the direction of the shaving stroke so as to more easily slice and cut the hairs on the shaving surface. The blade-housings 12 of the first row are inclined in an opposite direction to the blade-housings 12 of the second row in order to minimize lateral movement during shaving.
FIG. 12 shows another embodiment of this invention. Here, handle 52 is connected to a rigid razor-housing cover 42. Foam 27 is resilient and pliable and is attached to rigid razor-housing cover 42 on one side and blade-housings 12 on the opposite side. During shaving of a contoured shaving surface, blade-housings 12 tilt and/or move as dictated by the slope of said contoured shaving surface. Foam 27 expands and contracts in a resilient, pliable fashion in order to accommodate said blade-housings movement.
FIG. 13 shows another conventional option of using dual blades 8 and 10 instead of single blade 7 shown in FIG. 10 for each of said blade-housings 12.
FIG. 14 shows an alternative embodiment of this invention to the embodiment shown in FIG. 16. Rubbery, resilient, flexible sections 77 may be made of polyurethane foam, soft rubber or other similar material. Said foam sections 77 attach blade-housings 12 to flexible, resilient ribs 11. The cross-section of ribs 11 shown here are circular, but any cross-sectional shape may be used. Foam sections 77 provide low-cost, omnidirectional swivels for blade housings 12. Said swivels allow each of blade-housings 12 to flex in any direction in order to remain perpendicular to any rounded or variably contoured shaving surface during shaving. Thus, a much lower force may now be applied by the user to the razor handle in order to achieve said perpendicular shaving result versus the no-swivel approach shown in FIG. 15. Additionally, said resilient foam sections 77 furnish a return-to-center position force to each of blade-housings 12 when the razor is disengaged from the shaving surface.
Referring to the embodiment shown in FIGS. 15, 17 and 18, the flexible, sectionalized razor system shown is used for shaving any rounded or variably contoured shaving surface 16. The user simply grasps handle 5, and pushes the razor towards said shaving surface 16. Thus, ribs 11, which are flexible and resilient rods carried by handle 5, bend during each shaving stroke and force each of blade-housings 12 into perpendicular contact with shaving surface 16. Blade-housings 12 are connected together by v-grooved plastic hinges 29. Hinges 29 extend along the side of each blade-housing 12 and each hinge consists of a thin, flexible strip of plastic that is attached to an adjacent blade-housing. Blade-housings 12 flex about hinges 29 as dictated by the contour of shaving surface 16. Since each of blade housings 12 is individually connected to handle 5 by means of long, resilient ribs 11, each blade-housing 12 is pushed with substantially equal force toward the shaving surface 16, independently. Therefore, blade-housings 12 will flex and move automatically so as to follow any contour of the shaving surface, since ribs 11 act as resilient, flexible springs. The v-grooved plastic hinges 29 prevent any of blade-housings 12 from slipping askew on very steeply contoured portions of the shaving surface 16.
Blade-housings 12 are arranged in two parallel rows, as shown in FIGS. 15 and 18. The blade-housings 12 in one of these rows are staggered relative to those of the other row to insure that the gaps 14 between blade-housings 12 that would cause ribbons of shaving surface to be missed are properly shaved. As shown in FIG. 18, typical blade-housings 22, 26 and 28 are in the front row and are staggered relative to typical blade-housings 20 and 24 which are in the rear row. This staggered procedure is continued for all the other blade-housings 12 shown in FIG. 18.
FIG. 16 shows an alternative embodiment of this invention to that shown in FIG. 15, wherein ball-joint swivels 34 connect ribs 11 to blade-housings 12. This allows the flexing and/or pitching motion of blade-housings 12 during contour shaving to be achieved in a more efficient way. That is, less rib-bending force is now required by the user when pushing handle 5 towards the shaving surface 16. With less force required, the user is able to enjoy a more effortless shave.
Referring to FIG. 17, blade 7 is attached to body 21 by means of screw 19. Used shavings and lather exit through ports 18 through covers 17. Safety guard 23 is conventional and keeps razor blade 7 at a fixed distance from shaving surface 16.
FIG. 19 shows yet another embodiment of this invention which is similar to that of FIG. 18, the primary difference being that plastic hinges 29 are deleted. This approach may be used in low-priced systems where the cost factor is paramount and where some slipping askew of blade-housings 12 on steep contours is judged to be acceptable.
Another embodiment of the invention is shown in FIG. 20, wherein the blade-housings 41 are oriented angularly relative to the direction of shaving. Compared to FIG. 15, fewer blade-housings are required with this approach. Now, adjacent blade-housings 41 in only a single row are able to shave the shaving surface without leaving unshaved ribbons between adjacent blade-housings.
FIG. 21 shows another embodiment of this invention. Here, handle 52 is connected to a rigid razor-housing cover 42. Resilient springs 43 are attached to said rigid razor-housing cover 42 on one side and blade-housings 12 on the opposite side. During shaving of a contoured shaving surface 16, blade-housings 12 flex and/or move as dictated by the slope of said shaving surface. Springs 43 compress and expand in order to accommodate said blade-housings 12 movement. | A flexible, sectionalized razor system is provided for shaving rounded or variably contoured shaving surfaces. The system includes a plurality of individual blade-housings, each of which carries a separate blade, wherein the blade-housings are connected by connecting means of either ribs, resilient foam, soft rubber or spring means to a handle. In the preferred embodiment, the blade housings are arranged in such a fashion so as to avoid unshaved ribbons of the shaving surface caused by gaps between adjacent blade-housings. The blade-housings may be mounted peripendicularly to the direction of shaving or angularly to the direction of shaving. Another embodiment provides two parallel rows of blade-housings wherein one row is staggered with respect to the other row. | 1 |
FIELD OF THE INVENTION
The invention lies in the field of toys and games.
BACKGROUND
Throwing and catching games have long been a popular form of exercise and entertainment. They are also an excellent method for developing hand and eye coordination. Throwing and catching games typically require more than one player if they are to be played in a challenging and entertaining manner. This is because a person playing catch alone is limited to a small radius in which they can feasibly run after throwing the ball alone, and because there is little challenge in catching a ball when you know where you have thrown it. Thus, a solo-player throw and catch game is not usually expected to be very challenging or entertaining.
SUMMARY
The claimed device seeks to provide a throw and catch game that can be entertainingly played by one person. It is a further object to provide a game that automates the throwing and scoring parts of the game, allowing one or multiple players to focus on the challenge of catching.
The Applicant herein describes a game that launches balls automatically and at unpredictable directions and speeds. The launching and catching are incorporated into a single handheld device, making it fully entertaining and challenging even when played by only one person. The claimed device also comprises a hand-held target with a variable-size aperture for catching the ball. The size of the opening can be made large or small to change the difficulty of the game. Thus, the game features two types of difficulty to entertain the single player: variation in ball-launching, and variation in catching difficulty. The game can be played by multiple players who catch balls from the other player's launching device, and another embodiment of the game comprises a standalone automatic launcher from which one or more players can catch launched balls.
The claimed device incorporates electronic scorekeeping, including electronic detection of scores and electronic display of scores. As such, the game facilitates score-tracking and competing with other players. It can also incorporate speakers and LED to add sound and visual reward factors when the player makes successful catches. Finally, the game is convenient for storage and play, by incorporating ball storage and launching in one handheld unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of the handheld game.
FIG. 2 is a side view of the handheld game.
FIG. 3 is a top plan view of a horizontal cross-section of the handheld game.
FIG. 4 is front view of a cross-section of a standalone ball launcher.
DETAILED DESCRIPTION
This is a paddle-type catching game that is playable by a single player, easy to store, and incorporates randomness into the game play. The game is a handheld device comprising a handle 11 and a target frame 1 . The frame holds an adjustable target 10 , such that the goal of the game is to catch balls through the target 10 . The balls are launched directly from the handheld game itself by an automatic launcher 6 , and moreover the frame is hollow to facilitate storage of the balls and also to feed the balls directly to the automatic launcher. The automatic launcher, described in more detail below, incorporates randomness into the game play, such as by varying the direction of launch, the number of balls launched, and the speed of launch.
The handheld game also comprises electronic scoring and control, including, but not limited to, a sensor 12 to detect catches through the target 10 and a display 8 showing the score. Display 8 may show any additional information readily programmable by one of ordinary skill in the art given the electronic functionalities herein described, and may be located anywhere on the handheld device. Catch information can also be recorded and uploaded to a server via a Bluetooth or wireless controller, allowing the user to track their progress. The sensor 12 may include one or more sensors including infrared sensors located on the underside of the handheld apparatus in order to sense a projectile passing through the target area, piezoelectric sensors for detecting additional weight within a net 13 , and may also include touch sensors and motion sensors such as gyroscopes. The handheld device may also comprise readily programmable elements such as LEDs and/or speakers to light up and/or make noises on player “misses,” such as the ball hitting the frame and missing the target. These electronic additions can also be used to show and/or play rewarding visuals and/or music when the balls are successfully caught. LEDs can also be used to decorate the frame, or the frame may have glow-in-the-dark elements.
The frame 1 may be circular, as depicted, to exemplify a paddle-type game, but may be any shape of frame. The frame encircles or holds a target 10 whose aperture diameter is adjustable, thus changing the difficulty of the game. The target may comprise a plate that is insertable into the frame, the plate comprising one or more openings of different shapes and/or diameters. Multiple interchangeable, insertable targets allow customization for different levels of difficulty and entertainment. The target may also comprise an adjustable diameter aperture constructed as a mechanical iris. For instance, as in typical mechanical irises, the target may comprise a set of blades 19 that are pivotable and anchored to the frame, and an actuating ring disposed within the frame that causes the blades to rotate and thereby open and close the target aperture 10 .
The frame is hollow to facilitate the storage of balls, which can be inserted directly into the frame via window 2 . Furthermore, this storage lane facilitates the feeding of balls directly to the automatic launcher via launching area 5 , as illustrated in FIG. 3 . Balls fall into launching area 5 whenever it is empty, such as when the automatic launcher is loaded. Launching area 5 may be located anywhere on the device but is optimally located where handle 11 meets frame 1 , particularly when automatic launcher 6 is incorporated into the handle. The automatic launcher may be spring-loaded, as described below, but may rely on other types of force, including, but not limited to, mechanical, pneumatic or hydraulic. The game does not require specially constructed projectiles and can be used with existing balls such as ping pong balls.
As illustrated in FIG. 3 , a cross-sectional view from the top of the handheld game, the automatic launcher 6 may be implemented with a spring driven plunger 7 . Catch areas such as notch 16 allow for the plunger to be loaded and held in place by trigger release 18 , which is released when trigger 15 is activated. Multiple catch areas may be built into the plunger to allow the automatic launcher to be activated at differing amounts of force. In another embodiment, the automatic launcher releases one ball first, then another ball moments later, increasing the challenge and unpredictability of the game.
Additional variation and randomness may be incorporated into the automatic launcher. In the mechanical version depicted in FIG. 3 , a wedge-shaped head 4 is coupled to spring 14 causing the wedge to bobble or rotate. When automatic launcher is activated, the bobbling wedge causes the ball to be launched in unpredictable directions. The wedge design of the head furthermore causes the ball to be launched at unpredictable angles. In another embodiment, the game is also supplied with balls of different weights and sizes, resulting in variable launch speeds.
In another embodiment, depicted in FIG. 4 , the automatic launcher may be separate from the hand-held catcher. Ball storage unit 60 can be used to store balls and cause them to automatically fall into position when automatic launcher 70 is loaded. As noted previously, the automatic launcher may be spring-loaded, as described below, but may rely on other types of force, including, but not limited to, mechanical, pneumatic or hydraulic. As previously described, the automatic launcher 70 may be implemented with a spring driven plunger 20 . Catch areas such as notch 90 allow for the plunger to be loaded and held in place by trigger 30 , such that the plunger launches the ball into the air when the trigger is activated. Multiple catch areas may be built into the plunger to allow the automatic launcher to be activated at differing amounts of force. Additional variation and randomness may be incorporated using a wedge-shaped head 4 coupled to spring 14 causing the wedge to bobble or rotate. When automatic launcher is activated, the bobbling wedge causes the ball to be launched in unpredictable angles and directions. The standalone embodiment enables a multi-player version of the game in which players, each using a personal hand-held catcher, compete to catch randomly launched balls. | A catching game that is challenging even when played by one player. The catching game is a paddle-sized hand-held device that preferably incorporates an automatic launcher and an adjustable aperture catcher on the same hand-held device. The automatic launcher incorporates randomness into the launching mechanism, in order to increase the challenge to the player(s). The game also incorporates an electronic sensor to determine when a catch has been made. | 0 |
[0001] This application is a Continuation-In-Part of application Ser. No. 13/538,068, filed Jun. 29, 2012.
BACKGROUND-PRIOR ART
[0002] The following is a tabulation of some prior art that presently appears relevant:
[0000]
U.S. Patents
Pat. No.
Kind Code
Issue Date
Patentee
7,493,974
B1
2009-02-24
Boncodin
5,856,629
1999-01-05
Grosch et al.
6,343,534
B1
2002-02-05
Khanna et al.
2,005,392
1933-04-18
Remus
4,589,341
1986-05-20
Clark
4,519,543
1985-05-28
Szuminski
6,216,740
2001-04-17
Bunya
[0003] This invention relates to a solar charging, battery powered, unmanned mine defeat vehicle. Current situations in specific geographic regions of the world have created a new need for defeating underground mines in desert-like terrain. This vehicle is especially to be used on existing paths in sand environments worldwide to protect against death and dismemberment, a long-time priority issue and establishes an effective tool for safe passage and security monitoring and creating secure zones. Both the facts of presence of underground mines as well as the importance of deterrence and prevention of positioning new mines are widely available to individuals. The necessity for addressing the issue of travel protection by foot on paths consisting of bare ground is the focus of the new vehicle as presented. The invention has the advantage of operating with Green Technology only and in areas that do not have conventional AC (alternating current) for charging or common petroleum based fuel sources for conventional gas engines.
[0004] The unfilled need for defeating mines in environments such as opens fields, village passages and trails between villages has always needed a method of solution. As the use of mines was common for numerous years, millions of mines are located and placing an equivalent number of humans at risk. Many solar powered vehicles exist but do not comprehensively address mines. Many methods exist for the protection from mines for personnel vehicles. Recent studies have indicated that a new degree of effort must be made spent into the success of what is first step to defeat of mines, that of limiting the placement of them. Thus creating the benefit of secure areas. Proactive security and containment is simultaneously performed as the vehicle functions to prevent further placements of mines.
[0005] In order to connect rural areas for trade, commerce, travel and ensure village stability, establishing and maintaining safe pathways is a central strategic objective. So as to achieve this objective in harsh environments and terrain this mobile platform facilitates missions making logistically supportable operations to provide security. This will provide a new force element for establishing and for continued physical security within and between villages or in developing areas. Integrating existing and future screening programs allows for more comprehensive and safer processes. In becoming part of the force structure, this equipment adds function and strength to achieve current and future missions. With basic instruction for operation, communication skills, improvised explosive device detection, biometric identification and checkpoint procedures the defeat system participates by providing simultaneous combined activities. The necessity of having a capable defensive security underlies the ability of a village to protect and sustain itself. Villager and soldier perceptions of security are an important contributing health factor as the nuance of safety is required for stability and growth in the area. The robot machine would integrate well working forward in platoon and squad sized forces. Additional consideration is given toward the positive contributions provided in riot conditions to monitor, assess, contain, capture and control situations which are in areas of immediate importance.
[0006] Several types of solar vehicles and minesweepers for detection and destruction of mines are known, each with a disadvantage. Many solar powered vehicles exist but do not comprehensively address mines. Many methods exist for the protection from mines for personnel vehicles and utilizing unmanned robots. The previous patent for a solar vehicle U.S. Pat. No. 7,493,974 to Boncodin is for human transportation. A minesweeping vehicle, U.S. Pat. No. 5,856,629 granted to Grosch et al. is for wide-open spaces. The U.S. Pat. No. 6,343,534 to Khanna et al utilizes many latest methods for detection without a simultaneous in place trigger and containment system or marking process. The previous U.S. Pat. No. 2,005,392 to Remus addresses the use of a deflector with the disadvantage of flat surface use only. U.S. Pat. No. 4,589,341 to Clark discusses a chute but is for foam use. The U.S. Pat. No. 4,519,543 to Szuminski describes nozzles on a jet aircraft. The patent of Bunya, U.S. Pat. No. 6,216,740 acts to only control the manifold operation.
[0007] This application is a Continuation-In-Part of application Ser. No. 13/538,068, filed Jul. 29, 2012. This invention improvement relates to the assemblies for use where economy of energy must be achieved for the controlled pressure application, dissipation and vehicle stability for the mine defeat system. There are several elements which are additive and independent included for various levels of performance. The particular machine described in the application is presented in its best mode for a single pathway clearing system as described in this specification. Synergy exists in the assembly of apparatus by first being blast triggered by the closer initial offset distance towards the mounted blast plate at the rear of assembly which is strut mounted to the vehicle platform. The pressure field is relieved and dissipated by the system of energy absorbing struts, billows curtains and expanding canopy. The machine reacts rearward and upward as the pressure is relieved in the pressure wave direction and each side flexible face, functioning as a 3D dissipating containment system.
[0008] This equipment clears a minimum, substantial 32 inch wide path, for personnel in single file traversing pathways with detection, verification, sensors, surveillance, disarming, detonation, containment and path marking all in one process. This method of defeating a mine keeps people and personnel at a distance from the hazard with prevention, simultaneously. Pressure wave, fire and fragmentation from all mines occur within milliseconds of triggering the device and it is necessary to defeat this type of device from placement to containment, specifically anti-personnel type mines. The one vehicle makes available the necessary functions of soft protection methods and direct mechanized means. This addresses the two-part problem of mines, protection from initial placement while also providing safe detection, removal and containment, a combined comprehensive approach to defeating mines.
SUMMARY
[0009] It is the objective of the present invention to create a new use for a solar powered vehicle to provide a improved combined compact mine detector, monitor and sweeper and containment apparatus in the most austere environments to run without conventional fuel driven power using only Green Technology. The vehicle is a battery based DC (direct current) motor drive recharged with a solar module attached onto the forward sloping frame. It does not require daily fueling. Introducing equipment that is designed to be small in size and intended to be durable and cost sacrificial utilizing mechanical and detection means having the advantage of self-contained capabilities. The goals and approach are solely based on control of spaces at risk to mine placement and provide a cost-effective, high performance solution with known survivability limitations and budget-sacrificial equipment loss and only life saving and casualties reduction made as a variables of measured value.
[0010] Operation speed and maneuvering including tight turning is afforded by the fact of equal wheel base to track width yielding nearly a zero turning radius. Any of the customary control methods are possible, including remote or wired joystick as leader-follower arrangement, satellite, or run automatically on memory-learned pathways for routine path mine checking.
[0011] Common current field practice operating unmanned vehicle involves avoiding and maneuvering around debris and small stones and rocks, which lay in a straight-line path between two points of the objective route. In order to remedy this in an efficient condition of operation, an alternative method is made available as an option to drive in more direct pathways. A preferred method of ground preparation is to produce a near free of debris surface as possible. As an advantage, a debris deflector that has multiple panel segments, which naturally track downward onto the existing path cross-section, carries out ground preparation. The self-leveling debris deflector is counterweighted for a net self-weight of approximately a 3-pound net downward force per segment. The assembly remotely retracts for transportation to site. The assembly remotely retracts for protection during deactivation attempts or detonation.
[0012] Remote retractable robotic arm is deployed from recessed chamber to execute disarming when desired. An air tube routed to the deflector base from the gas ejection system is a tool for air blasting sand to uncover mines. Optional sensors read incoming path profile and controls deflector and probe assembly. The feedback loop created maintains a telemetry system for all ground sensors. Procedure also may include sidestepping mine and installing a flag for the affected area.
[0013] For normal conditions, the vehicle travels and a simultaneous area proofing and containment countermeasure system operates, a new countermeasure for field use. A specifically arranged configuration and assembly for replicating foot motion and pressure with a compound articulating mechanism is employed. A controlled pressure (0 to 30 psi) vertical reciprocating system for mine activation is utilized for positive soil contact and pressure to be delivered across the width of the vehicles pathway. A curtain billows, plate and canopy system for detonation dampening for expansion is utilized. A secondary fast response counter deployment system for canopy ejection is also presented.
[0014] The various elements that work together or individually in turn function together in an accumulating efficient manner reducing battery load requirements to operate the vehicle mechanical functions and computer systems. The components and assemblies are described as a prestage gas ejection detector, probe head boot, a strut probe assembly to impart a minimum of downward force, a timed pressure manifold for strut(s) and a strut energy dissipating canopy with chute.
[0015] As the prevention of mine accidents is paramount, longer operating times for the mine defeat system are preferred increasing daily service time. Each element described contributes to lowering energy demand and/or vehicle stability.
[0016] As the vehicle has its vertical probe assembly attached to the vehicle for clearing mines from a pathway, a strut can be used to provide a downward force. This force is used to drive the reciprocating probe which has the added potential of drawing dynamic energy from its' speed in impacting the ground. A constant pressure control is introduced in a timed manner through the use of the pressure manifold and relay to achieve the lower reaction force when the probe is not in extension mode for each cycle.
[0017] The pressure manifold and relay is located in an area away from the containment space. It combines the signaling of the probe head cycle for probe extension with the opening and closing of volume space in the strut(s). The function of controlled volume is provided with the primary feature of strut rod movement. Additional mine detectors will enhance the triggering to dissipation process.
[0018] The ability of the machine's probing units to move along will be improved by utilizing carbon fiber or other blast resistant material wrapped around the base of the probe or shoe acting as a flexible boot. A positioning of a mine detector will allow for prestage gas ejection. The probe head assembly may utilize a control ball knuckle for limited directional range of motion.
[0019] The placement prevention of mines is simultaneously done in an active format through constant motion and personnel verification using a 360-degree turret to create safe-zones, which is a primary focus for all countries. In each typical village, small areas shall benefit, primarily villages and village connecting trails. Rotation of the camera of 45 degrees to left and right provides 360 degree of coverage with the turret operational. The majority of mines are delivered and set in place by individuals or groups who reside outside the community or village at risk. As an advantage in the self-contained and efficient capabilities, the vehicle is able to continuously perform motion detection and identification checking, through this simple but new effective data gathering technique.
[0020] At the rear of the containment plate are mounted three trailing hooks left, center and right.
[0021] A path marking system for centerline and low spot paint applicator is the last apparatus mounted.
[0022] Green Energy recharging methods may be assembled in various arrays and modules with concentrating prism lenses to add to the recharging abilities.
[0023] As an improvement accessory, where the surrounding terrain requires a better traction, the vehicle has the ability of use of additional flexible tracks to be field installed.
[0024] Adjustment for width of path utilizing all or any these devices is possible for wider or narrower path requirements.
DRAWINGS
Figures
[0025] FIG. 1 is a perspective schematic view of a green energy powered minesweeping vehicle according to the preferred embodiment of the invention.
[0026] FIG. 2 is an interior schematic section showing the chassis-body-drive arrangement.
[0027] FIG. 3 is a side elevation schematic view depicting the configuration of the mine countermeasure system.
[0028] FIG. 4 is a rear perspective schematic view of the exterior of vehicle.
[0029] FIG. 5 is a rear perspective schematic view of the vehicle.
[0030] FIG. 6 is a partially exposed rear view.
[0031] FIG. 7 is a plan schematic depicting the Green Energy Thermal Electric Generator/Gas Reactor Module.
[0032] FIG. 8 depicts one alternative for a gas ejection system.
[0033] FIG. 9 is a perspective schematic view of a powder actuated warning flag.
[0034] FIG. 10 depicts an isometric view of the electromagnetic charge system.
[0035] FIG. 11 depicts the integrated shutter, cartridge cell and TEC assembly.
[0036]
[0000]
Drawings - Reference Numerals
1
turret
2
canopy
3
camera
4
slide black Box
5
rear Blast plate
6
flag deployment system
7
vertical reciprocating system
8
concealed robotic arm system
9
self leveling system
10
detector
11
deflector
12
thermal electric chips
13
turbines
14
energy conversion housing
15
photo voltaic cells
16
wheels
17
chassis-body
18
DC motors
19
batteries
20
turret
21
chassis-body
22
gas tank system
23
gas nozzles
24
gyro
25
curtain billows
26
rear blast plate
27
mounting rod
28
hinged sliding spline control bracket
29
strut-cartridge
30
foil lever
31
control volume solenoid valve
32
vertical reciprocating power-head
33
axial actuator
34
charge assembly
35
remote deployable flag
36
open edge
37
trigger
38
anchor base
39
powder actuated anchor
40
recoil rod
41
optional additional anchor base
42
spring to rod connections
43
pressure activation lines
44
pressure system
45
apron
46
probe boot
47
probe shoe mine detector
48
electromagnetic coils
49
gas cells
50
chute
DETAILED DESCRIPTION OF EMBODIMENTS
[0037] As shown in FIG. 1 , is a new use non-conventional sized battery powered, solar charged, unmanned vehicle that is sized so as to create a clearing path for people travelling on foot. The first apparatus 11 is the self-leveling debris deflector. The primary chassis contains a solar panel 14 with a high resistant and magnification surface 13 . From FIG. 2 , a vertical interior section view looking down with the four drive wheels 16 can be found. Inside the chassis 17 are normal DC drive motors 18 , current controller means and the battery set 19 . The top of the chassis provides space for an optional bio-fuel power-plant that is not necessary but would provide added daily service hours that may be of advantage. In front of the chassis is an optical camera 3 for close in monitoring of operation of robotic arm that is stored in a recessed chamber 8 and for warning flag 6 positioning. Above the chassis is a structural frame, which acts to support the green energy module 14 . This panel is secured to the frame with isolation attachments should an event causing toppling occur. The panel surface is damage resistant.
[0038] Many types of Green energy sources are possible for energy conversion for power and recharging in the industry's current technology. The differentiating detail noted in the following method is the aspect of energy being created by both solar and gas means for recharging purposes. The system is not limited to energy generation by heat reclamation from internal processes. The following embodiments of green energy use are described in sufficient detail to enable those skilled in the art to practice the invention. One or more multi-stage systems may be used in parallel are contained in a protective housing that is field replaceable as a unit for maintenance or from damage with quick connect frame attachments and energy cables.
[0039] The proposed system has the following process to convert both thermal and light energy using sunlight and gas. Contained in a protective container are several elements which transform energy. The simplest form is the photovoltaic cells which may have a magnification prism or lens for intensification. These are distributed in the container around all other elements which are of irregular geometry. They provide immediate voltage from sunlight exposure.
[0040] Another electrical generating method contained is a liquid to gas vapor system wherein the vaporized fluid is channeled through a turbine generator 13 . The time controlled heating of fluid to gaseous phase is accomplished by a set of shutters. A magnification lens focuses sunlight to vaporize the working fluid. One way pressure valves control the flow of fluid in the system from the fluid chamber to the heating chamber through the turbine to the vapor chamber for reliquification.
[0041] The working fluid may be methanol, ammonia or acetone although other fluids may be used. The vapor is reliquified in the heat transfer device for use in the system again. The heat dissipation device may include elements such as fins or rods that provide large surface for providing spreading and dissipating heat 12 including volume expansion devices. Other effective means such as capillary channels may be used to improve efficiency for vapor reliquification. The primary effective manner of phase change rate is to provide a permeable membrane to make an efficient mass transfer process. The process makes use of capillary transport force acting on the interface of the porous material thereby increasing the rate of vapor venting and removal of corresponding heat flux. A classical evaporator and condenser system may also provide for to maximize the reliquification process.
[0042] An additional method for turbine generated energy is included by the introduction of either pure gas such as propane by pressure cylinder vessels or concentrated solid pellets with known dissociation kinetics can create a reaction cell 49 for daily use. The pellets may be of any size which maximizes the liquid gas reaction. The pellet would then combine with an adequate solution and/or catalyst to facilitate the gas expansion phase in the cell. A series of cells forming a cartridge like insert, FIG. 11 is possible for cell by cell depletion having the individual cells connected into a parallel manifold pipe. Each of the cells having a pressure sensitive orifice disk which ruptures at a predetermined pressure or temperature. Each cell being activated by automated timed sunlight shutters with magnifier lens. Upon depletion of the cells gas concentration, the sunlight shutter is directed towards the next full pellet cell. This pressurized gas then passes through the turbine for additional electric charge. In line flow restrictors control any overpressure. These pure gas methods are utilized by providing a by-pass tube allowing for venting externally away from the evaporator condenser process elements.
[0043] The total package delivers an effective optimized combined multi-process for exploiting green energy. The combined Thermoelectric Generator 12 /Gas Reactor charging system will allow for longer daily use of the system.
[0044] In addition to the previous discussed energy methods for conversion. The current state of the art allows for other various methods of conversion. Additional capabilities may be achieved by the use of hydrogen cell power conversion charging stations. These stations can greatly extend the network and range of coverage for the individual containment robots. Each station would allow for overnight charging which would make the daily duty rating increase. The typical station can be a standalone protected structure for the power generator and containment robot. The primary low demand and low cost continuous refueling requirements would be vessels of water, hydrogen and routine maintenance.
[0045] The supporting frame is also a shock cage, which has internally telescoping cylinders for force dampening. Above the shock cage is the turret 1 which is able to swivel horizontally 355 degrees. The turret 1 contains two optical cameras 3 , one forward that creates 3D vision when synchronized with the lower chassis camera 12 and one to the rear for real time monitoring and motion detection and verification. Motion to identity security containment and control is accomplished. This significantly protects those registered in the safe zones and residing in the secured areas with personnel and civilians using IC Card verification. A simultaneous process of motion detection with verification of safe zone identification signals is read by computer hardware in the black box 4 . Establishing this security process in any area of mine placement activity defends against further mines from being placed. The onboard capacity contains the logistics that would assemble information into a centralized database for use with and for field personnel to access this remote mobile vehicle. Information integration and analysis becomes real time. Verifying ID, document check, and controlling a single identification is extremely crucial as the ease of multiple identities is wide spread. Selective biometric applications involving identification cards containing radio frequency capacity technology for control movement in secured zones. Modernization programs rely on individual identification cards being required to carry. The following soft approach abilities for data gathering are presented for use in an efficient integrated fashion at low cost. Each optical camera is included in a self-contained blast resistant removable black-box 4 , one on each side of the turret, which contain operational control and communications integrated circuits and hardware. The turret is also supported from the rear by the back wall, hinged at the top, for additional dampening benefit.
[0046] The self-leveling and retractable debris deflector 11 is illustrated in FIG. 1 . Each panel section is slightly angled from the vertical and from the path centerline forward, so as to give a rolling momentum impact force out and away from the path of vehicle. Each panel segment is connected by a simple hinge-pin mounted at mid-panel height. The panels are overlapped so as to create uniform coverage while sloping up or down on the path's surface. From the existing ground surface, tines are placed which act to catch and clear individual stones larger than ¾ inch round in size. The deflector panel assembly is fitted with guide rollers, which produce very little downward force when not mechanically controlled with a height sensor controlled system. The assembly is supported by two side arms that act to maintain a controlled forward projected distance from the chassis and allow for upward rotation retractability when not in use. The total assembly creates a self-leveling effect. Immediately behind deflector panel assembly is mounting table and detection device 9 . Within any of the pivot mechanism sections, a net may be contained and remotely deployed by any method known in the art. The top of the sensor assembly may have a secondary canopy mounted over.
[0047] The primary countermeasure system is illustrated in FIG. 1 and is a new assembly or unique apparatus for simultaneous triggering and containment of mines. The three features are shown at the rear of the vehicle. The vehicle may work in reverse direction where hazards are extremely high to maximize containment advantages. At the rear of the vehicle a vertical reciprocating system is shown 7 , followed by a containment plate 5 and covered by a canopy deployment system 2 .
[0048] From FIG. 3 , the rear of the vehicle can be seen. At the ground surface, each reciprocating foot 32 assembly has a determined width, which applies the appropriate pressure based upon the range of in-situ soil shear strength present where mine detection is to take place. The advantageous feature being created is that the reciprocating system assembly self-propels itself in two distinct ways. First, the individual line of action is inclined a few degrees from vertical, as a foot does. Secondly, the lower control arm has an axial actuator, which has a controlled advance throughout the timed cycle of operation. Each foot has a power head that provides a means of rotation and a controlled variable positive soil displacement, which acts to alter soil at or below surface and accomplish the mine trigger objective by simulating foot pressure and motion. Accomplishing triggering, ignition or downward force may be by any means known in the art which may include, but not limited to, plasma, rollers and electric inductance or electromagnetic means.
[0049] The modular, preloaded feet with reciprocating probes are signaled to cycle in a timed fashion for maximizing the net downward force. Downward force for each assembly is provided by a preloaded pressurized strut 30 , supported by a vertical spline control bracket 28 , which limits horizontal range. The configuration of this apparatus is designed to remain in a horizontal orientation for existing ground undulations of plus or minus three inches and maintain continual ground contact.
[0050] From FIG. 3 , an improved embodiment may be utilized in the form of a dissipating strut and probe assembly for the clearing of mines from pathways. To ultimately reduce the drag for motion and improve vehicle stability, a plurality of elements are utilized to work together or can be used separately.
[0051] In this embodiment for said dissipating struts 30 , an improved strut performance can be realized. Each strut utilizes a control volume for manipulating the amount of gas/fluid to be displaced during extension and compression. While the reciprocating function of the probes are under way, the control of downward force is controlled in a cycled manner from a lower pressure value to a timed and synchronized higher value. Both values are able to be controlled by the predetermined size of vessel and the internal rate of displacement from the rod extending or compressing when entering and exiting the strut cylinder. The cycling operation is activated by the use of an internal solenoid valve 31 mounted into the control volume wall which when activated opens and closes the additional internal control volume within the strut chamber. The cycling timing of the solenoid valves is accomplished by the computer or a separate controller which sequences the strut high pressure level with the probe extension.
[0052] In another embodiment, a pressure system 44 with accumulator and manifold has pressure activation lines 43 connecting from the dissipating struts to a timed pressure manifold and relay system which combine electrical signals and line energy to open and close manifold valve ports, extend each probe assemblies, being branched and controlled separately to sufficiently cycle the probe extension with high strut pressure in a sequential manner. A controller sends signals to the relay of the manifold and to activate the probes together in a cycled and sequential manner of operation. Activation lines may be energized in an air, electrical and/or hydraulic manner. A combination of the two methods may be utilized for maintaining redundancy and improving reliability.
[0053] The strut controls the amount of downward force on the probe head. The overall assembly may be raised or lowered by rotation through a hinge located on the spline bracket and may be by hydraulic means. The spline plate brackets may be used independently for each strut and probe assembly or mounted on a single plate. The movable plates and their positions have a maximum load rating in the extended down operation position that freely release upon detonations by means of a breakaway link, load failure device or other load limiting mechanism that may incorporate an axial piston or other suitably fashioned device to relieve over-pressure. The primary combined feature is a piston lowering the hinged plate and upon a specified overload pressure, the plate rotates closed and simultaneously slides up for a short distance. This combined mechanism and load path creates a deadening effect for the short duration of the pressure wave.
[0054] As an alternative, another possible arrangement for the probe head connection and to maintain vertical orientation of the probe action is through the use of a modified connection, a spherically seated control knuckle providing a limited range of rotation. This may allow for more extended use in the field should damage occur. In this embodiment, the base of the strut rod is connected in a vertical plane hinged manner, with a slight degree of out-of-plane deflection possible, to follow the existing ground profile. One embodiment of the connection is to use a control knuckle which has a ball or spherical shape connecting to a similar shaped receiving yoke type socket mounted vertically into the top or side of the probe head surface. The top of either type ball shape used is further guided and controlled in a single vertical plane direction with limited angular range of motion in both rotational directions, accomplished by having a rectangular opening in the top of the socket face and attached to the probe head. The load exerted through such an assembly causes forces to be transmitted normal to the plane, perpendicular to that mounted plane which achieves a desired inherent self-balancing downward force. Said knuckle design may allow for single connection to probe head should damage occur to other links. This forged spindle ball joint has a controlled seat.
[0055] The strut assembly may have a critical break-joint design feature to have a planned strut loss to enhance vehicle stability. The break joint may consist of a reduced section of the strut rod or an equivalent means for high load failure. A plurality of mounted dissipating strut assemblies are possible. Each strut assembly may have a pressure limit valve or blow-off for relief of pressure in or on the strut housing for relief activation during the mine event.
[0056] To further absorb energy and in order to minimize energy, the configuration of certain element may be introduces into the configuration of the strut probe head assembly. A unique arrangement of benefit may be utilized. The probe head or other triggering mechanism may be configured so as to have a slightly cupped face facing towards the imminent blast point. The effect of concentrating a calculated percentage of force through the strut would be directed into the recoil bore assembly. Additionally, a portion of the pressure wave will be redirected. The probe head face plate may have a V shape or other shape to direct forces. To increase the pressure rise time a layer of viscous material may be added onto the face plate of the triggering mechanism.
[0057] The strut assembly having a central rod becomes driven through the strut housing. The strut rod and housing assembly may be conventionally axial in action or be curvilinear and may have a pivot connection. As a method to slow the instantaneous effect of the blast, the strut rod may be made longer to achieve a better time of dampening forces. Absorption of energy is treated as recoil except the gas or fluid orifice pressures would be containing the rod force at the end of its travel acting as a shock isolator. The first rod distance traveled acting as a common shock absorber and after a predetermined overpressure an internal valve would open and the full range of rod travel into a secondary gas or fluid pressure chamber. Any series of orifices, secondary cylinder walls for relief volume may be used to increase the duration of recoil impulse and absorb energy and momentum.
[0058] The assembly may have a mounted or body formed muzzle for replaceable reaction charges. The charge 34 may be initiated by a direct connection or signal from the probe of the head assembly to the charge in the breech upon triggering a mine. The reaction of these charges may be of various sizes and will be directed so as to counteract the upward force from the mine onto the machine. Establishing the exact position and direction for this feature will be accomplished by those skilled in the art.
[0059] The probe head contains the means for providing a reciprocating probe element. Additional mine detectors will enhance the triggering to dissipation process with an advance signal to start. This may be created by positioning the mine detector sensor on or near to the probe head. In operation, as the machine is in motion, a mine detected or located near to the probe head mine detector sensor 47 sends a feedback loop signal for gas ejection to start a few moments before the probe detonates the mine.
[0060] Any type mine detector known to exist and in the art may be attached and located in any position on the vehicle which would assist in the determination of the specific location of below or above ground mines. Mine detectors are commonly located as close to the ground as practicable. Guide roller surfaces may be included in the induction field circuit. Mine detectors may be added at the base of the deflector segments in a variety of connection means such as attachment to the individual deflector segments and probe head shoes through the use of small connection tables, brackets and shelves as well as a more ruggedized, potentially molded integral assembly, whereby the individual parts, such as but not limited to the deflector plate segments, sensors or probe head shoes form an integral, composite or a detachable-attachable assembly. The individual mine detector sensors can be hinged with springs to allow further improved ground clearances, pitch and angle of incidence and be attached by any practicable means known in the art including as a slide or snap on component.
[0061] The combined elements of probe head, probe head shoe, probe and prestage detector or parts thereof may be covered for ease of sliding motion over the ground as well as protection, by a flexible carbon fiber or blast resistant material acting as a boot 46 or jacket element for additional guarding against sand and foreign elements. The material of the boot shall be flexible to allow for the repeated probe extension cycles.
[0062] The attached mine detector mounted on the front of the vehicle locates mines. As these mines are located, a signal is sent through the feedback loop and are recorded for relative location which also may include positioning by satellite in the on-board computer located in the blackbox. The location of the vehicle is converted into data by two methods. The first is by common GPS positioning. The second is by surveyed range locators that are read by sensors on the vehicle for grid locating and stored on the computer. Other means for determining and storing distance travelled and grid location, along with user remote control exist to those skilled in the art. The blackbox protects these remote controlled, automatic and guidance control features for operation. The machine having possession of this information, along with its inherent motion tracking, calculates by means of computer when the mine shall approach the rear probe assembly with mine detector. As the machine is working its' way forward or backwards and nears the located mine, the gas ejection system is activated at a predetermined time or manually before detonation. Detonation may be accomplished by any of the known methods available known to those skilled in the art.
[0063] When the mine detector encounters a mine, an electrical signal is sent to the computer for creating a grid location using known range locators. Satellite positioning data for longitude, latitude and elevation is recorded in the computer. The gas ejection system 22 is started for the release of gas. The gas may be stored in vessels under high pressure in a protective enclosure mounted to the vehicle. The mine detector sensor signals the computer via the feedback loop and activates the solenoid valves or other means of automated valve opening actuation being electronically controlled by the detector sensors or the computer located in the blackbox. The overall operation of the machine is synchronized by the onboard computer using integrated circuits which may be remotely operated. Any means of directing gas common to the art may be used, openings, ports or nozzles 23 to control and direct the flow of gas upward, such as a plurality of ports, outlets, tubes or nozzles which effectively direct the gas jet in the directions desired. Upward directed gas shall deploy canopy and have detonation balancing force and horizontal force to either assist to propel in the forward or rearward direction. Control of gas ejection in any direction is controlled by the computer or remotely for thrust and exhaust velocity. As an example of control of gas, a series of electronically controlled automated valves controlling the gas in each direction can synchronize the control of gas in the desired directions. Other means of gas ejection exist in the art which create sufficient gas ejection and downward force to assist in the counterbalancing of the machine or vehicle before, during and after detonations for improving vehicle stability.
[0064] The combined elements of probe head, probe head shoe, probe and prestage detector or parts thereof may be covered for ease of sliding motion over the ground as well as protection, by a flexible carbon fiber or blast resistant material acting as a boot 46 or jacket element for additional guarding against sand and foreign elements. The material of the boot shall be flexible to allow for the repeated probe extension cycles. The Green Energy Mine Defeat System improved components enhance the performance and stability while reducing maintenance time for longer durations in-service.
[0065] In order to improve planar stability, one or more gyroscopes 24 may be employed. A lightweight disk of sufficient weight may be mounted and spun on the structure so as to resist toppling. The axes of rotation shall be set so as to contribute to maintain controlled lift along with roll and topple forces from the event. The action of starting the gyro would commence before and reach full speed before the event. Each Gyro may be supported with isolators of viscoelastic materials or other materials known in the art. The skilled in the art will adjust the global attitude of each gyro assembly to maximize the affect for vehicle stabilization.
[0066] Behind the vehicle chassis 21 is a containment blast plate 26 , positioned upon status change to encompass the projected inverted conical zone of pressure, fire and fragmentation. Connecting the chassis to the blast plate is one variant of gas-fluid cartridges 29 with stepped release (0-200-800 lbs), which are body to plate connected, used as a dampening struts. The entire assembly is raised and lowered when not in use.
[0067] In another embodiment, an internal foil lever 30 creating a means of combined baffle and absorption are described. Within the stages of shock waves and fragmentation the rear blastplate is first moved rearward. In milliseconds after this action the pressure wave travels vertically upwards and strikes a plate of normal or curved geometry forming a foil and lever. As the pressure wave impinges upon the foil face it is pushed upward pulling on the connected energy absorbing struts which are in turn connected to the rear blastplate or other containment space element. This arrangement of a foil lever may be organized in such a way in the containment space in any multiple of times in any suitable arrangement to maximize energy absorption. At the leading face of these foil levers may include a suitable face to reduce velocity to subsonic speeds. The foil angle may be adjusted at any angle to manage forces that will contribute to balancing the overall stability of the machine. To assist in this action of flow control, a Lorentz force induced by an electromagnetic field may be used to improve any lift effect on the foil lever.
[0068] The billows 25 and curtain 25 are attached and assembled in accordion like manner on and along the sides of the containment space. The canopy 24 is attached in a folded parachute manner. Both are of a blast resistant material such as carbon fiber or better. As the mine is triggered, the blast plate and vehicle are lifted and sent in different directions. The blast travel distance is slightly less in distance to the blast plate 26 . Therefore, initially causes a reverse direction of the total assembly. Through this action and the gas-fluid cartridges 29 , energy is dissipated with a reaction being centrally resisted by the mass and size of the reciprocating system.
[0069] As those reciprocating system parts that are in ground contact and above are broken away as a reaction to the mine detonation, a feedback loop is broken and a fail safe signal located along the feet is tripped on, when the connection is broken. The connecting arms are limit rated and are subject to the first and highest levels of stress. Upon the signal being sent to the optional gas ejection system 22 , a propelled inert gas and fire suppression 23 system is activated for canopy deployment in an upward and reverse impulse direction. The canopy chute 24 path and speed is maximized upward for containment and canopy deployment from the top of assembly. A conventional set of three trailing hooks, left, center and right edges of the rear containment plate of the vehicle are employed to activate underground trigger mechanisms for offset hazards of aboveground, concealed mines.
[0070] In another embodiment, the canopy may have an intermediate or top section that is modified to mitigate the resulting pressure, fire and fragmentation. In this arrangement a single or multiple series of rectangular rings consisting of extensible rods, corner bars, and struts are used to form a strut ring. Other shapes to establish containment strut rings such as ovals, triangles, circles, polygons or curvilinear outlines are also possible. The resultant grouping from pressure wave reactions are established, the corresponding best shape fit which best dissipates the shock, pressure wave and fragmentation event.
[0071] The corners of the rectangle form reaction points. The corners have connectable ends which are able to make connection with pressure relieving struts 49 , which may be telescopic. These components may be either for multiple use or replaceable. The principle of use is that the rectangles form a frame that the blast resistant material is connected onto in a billows curtain 48 method and the curtain is so connected, possibly unevenly pleated, from side to side, so as to slide along the lengths of the rectangle ring sides into a fully expanded manner. Therefore, as the canopy rectangle is propelled upward and subjected to any force, it has the ability to expand and be subjected to the stress and strain in the horizontal plane through the struts along the respective sides and further being contained by the expanding billows curtain sides. The unfolding nature of the canopy with the rectangular frames with struts included as described have the ability to be stacked in repetition.
[0072] As a later stage failsafe method of energy dissipation and to reduce the number of elements involved for energy dissipation, a top canopy breakaway section may be used. The principle of locating internal fragmentation baffles before top liftoff would provide a means of relieving overpressure with an overall smaller canopy.
[0073] A chute 50 may be introduced as a possible arrangement for gas and pressure flow. This chute can be functional by having a side wall opening but with directional control. A chute opening may be placed on any side. The chute is a projectile proof mesh with either horizontal or downward orientation. Internal baffles as well as tension bands may also be incorporated in the internal compartment so as to control and dampen forces as desired. Internal foils and baffles are positioned to have the greatest effect to collapse, deflect and absorb energy.
[0074] A blast gate for any chute may be positioned at the entrance of a chute or foil. The gate acts as an initial pressure wave brake resisted by energy absorbing struts mounted to the gate plate and to the containment space. The gate orientation may be positioned so as to cause reactions from the pressure wave into the machine so as to absorb or contribute to stabilization. The chute may have a foil inside for reaction from lift. The concept of blast through structure provides for possibility of minimization of event reaction forces.
[0075] In a separate embodiment, a combined complementing element may be employed for vehicle and machine stabilizing and absorption requirements. As the triggering takes place, staged reactions are started and the pressure wave comes into contact with the internal mechanisms. In order to further dissipate the energy from the leading shockwave, a magneto flux sandwich system may be used FIG. 10 .
[0076] The pressure wave acting upward and outward reacts against any surface in proximity. The containment space so proportioned with triggering mechanisms present, create contact surfaces. The net result is to cause instability and overturning to the vehicle and machine. In aim to balance all forces, it is advantageous to compensate for these forces. A series of high strength conductive plates may be arranged in a sandwich configuration for an immediate impulse reaction. These sandwich assemblies may be sized, shaped, arranged and hinged in multiple positions in the containment zone so as to maximize energy dissipation and deflection. The entire assembly configuration may be fixed or shock strut connected to the vehicle or machine. Formations imparting couples into the frame may be realized.
[0077] The system power source may be by an onboard generator and assisted from a gyro fitted for current generation. A current field is generated and wired to the system. The system comprises two or more rigid or semi rigid plates with conductive strips, poles 48 or surfaces for providing current field induction. Permanent magnets may be incorporated into the plate surface. Each surface is connected so as to allow limited freedom of movement out of plane as well as in plane, each surface forming a plate that has any array of openings.
[0078] The complimentary offset plate or surface has a mated array of openings which may contain an inverted or planar opposite set of shaped ducts. The planar angle of each duct may be of any angle so as to maximize the effect of pressure wave reduction. As a second stage to the system, the surfaces or plates may be conductive so as create a magnetic field for attractive or repulsive force which may be from permanent magnets or electromagnetic means. The magnetic field and corresponding magnetic flux may be varied and is provided at a desired strength for resistance, opening and or closing and may be area attenuated. The plate movement action may be actuated from voltage from a capacitor source. The plates may be layered with dielectric material so as to maximize repulsion and attraction effects. The plates may be held at a distance relative to another by any mechanical means. Each plate may have any percentage of surface area open for pressure wave passage.
[0079] In one reaction case, the pressure field strikes the first plate and is pressed towards the secondary plate. As this motion takes place the magnetic field between the two plates is turned on, the plates acting into the direction of the pressure wave. In another reaction case, a second plate, having complimentary meshed ducts, is repulsed with sufficient flux density. As the pressure wave impacts the primary front plate the magnetic field is closed and the plates slam together. In both cases the opening or closing of the plates with the corresponding openings and ducts deflects and diverts pressure wave forces. Further reaction force can be provided by the use of pressure sensitive encased charges at the bottom of each port stub. The total amount of reaction force can be staged to react to the uplift force encountered.
[0080] Leading edges of surfaces and openings may have modified ridges for drag and velocity reduction. A plate may have no openings. A third plate may be sandwiched for additional deflecting effects. In order to improve the plate deflection characteristics, the use of baffles creating a leading drag layer of suitable material strength may be placed in front of the plates. Sensors, pressure transducers and relays may be used to control any advance or delay required to optimize controlling change of the flux density of the magnetic field in the system.
[0081] The combined components in the bottom containment system and the canopy top containment are so arranged to dissipate the energy field with respect to its vector and by stage of the mine event and respond in a predetermined and controlled manner. A split blast plate with pressure struts can be used. As is the case with many structures that may encounter pressure waves, dissipating, collapsible and compressible medium in layers may contribute to protection of the intended space and surfaces or vacuum control volume may be incorporated on the surfaces or within the containment space in order to mitigate forces to be resisted or deflected. Each of the absorbing elements and mechanism are positioned and analyzed in a global vector summary around the machine centroid to arrive at the best use to resolve the set of forces to achieve overall stability.
[0082] A centerline path marking system mounted at the rear containment plate is provided whereby a path centerline is prepared with wheel brush and air system and marking with specialized material/paint at coded spaced intervals. The system also automatically paints low spots and where not proofed, unchecked or for skipped locations.
[0083] FIG. 1 shows the warning flag tube 6 mounted on the top of the vehicles chassis. FIG. 9 illustrates the detail for the self-contained, remote deployed warning flag system. The vehicle carries a remote deployed powder actuated anchored unfolding warning flag 4 in the top or on the side of the lower chassis body. At this location or mounted onto the side of the chassis a single to several warning flags tubes can be stored. This self-contained function allows the administration of possible deactivation or detonation to be controlled in a more efficient manner in addition to keeping personnel involvement to a minimum for marking the hazard by remotely placing near to located hazards.
[0084] The individual flag 35 becomes upright when removed from tube and expand automatically with the individual sides being of flexible spring-to-rod 42 connections. Upon locating the anchor base 38 to its desired location by the operator, the base is positioned and trigger 37 discharged by the use of the robotic arm, securing it into the ground by the powder actuated anchor 39 making the flag spiked into the ground. An additional automatic trigger for discharge may be used at the far base location 41 . To aid in the ability to weather wind conditions, the top and base are vented 36 & 40 open to reduce blow over affect.
[0085] Through the progress of technology, the geometry and configuration of machine structure and components may be more streamlined and efficient. This process of development may include the energy dissipation, force balancing and containment elements being located anywhere in or through the structure, possibly within the wheelbase. The methods stated herein apply science and engineering result in a planned staged dynamic hysteresis through a vehicle or machine with mechanisms to trigger, absorb and contain a landmine blast.
[0086] The invention has been described with respect to particular embodiments, modifications and substitutions within the spirit and scope of the invention and will be apparent to those of skill in the art that individual elements identified herein as belonging to a particular embodiment, may be included in other embodiments of the invention as well. The present invention may be embodied in other specific forms without departing from the attributes herein described. The illustrated embodiments and examples of use should be considered in all respects as examples and illustrative and not restrictive. The devices described herein, individually or in combination may be advantageously be fixed as attachments for or onto other vehicles to achieve desired results which are needed. | A semi-continuous duty, Green Technology 14 , robotic vehicle providing protection and security from underground mines. A deflector blade 11 follows natural existing contours to maintain straight line paths, while simultaneously carrying a mine detector 10 , a vertical reciprocating ram set 30, 32 and 33 that preloads soil while also creating forward motion, followed by an energy dissipation, reaction system and containment canopy system 22, 24, 26 & 29. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to sliders for sliding clasp fasteners or zippers and has particular reference to an automatic locking slider of the type which generally comprises a slider body, a pull tab and a locking spring member.
2. Prior Art
A typical example of conventional sliders of the type described incorporates a locking spring member secured to the slider body in such a manner that a portion of the spring member can, under the control of the pull tab, move into and out of the passage of the sliding clasp fastener elements within a channel defined by and between the upper and lower shields or wings which constitute the slider body. The locking spring member is made of a resilient material, usually a stainless steel such that can provide sufficient resiliency to retain the slider in locked position against accidental displacement with respect to the fastener.
Known locking sliders however have a drawback in that when their associated fastener stringers are attached to a relatively heavy, hard article such as jeans, canvas, leather and the like, the slider is liable to get loose and forced out of its locked position under the influence of severe stresses tending to split the fastener stringers laterally apart or toss them up. This is primarily due to insufficient mechanical strength and resiliency of the locking spring member. However, the choice of stainless steel for the locking member that has sufficiently high cold rolling modulus and spring coefficient to withstand such stresses is often limited by the bending and shearing operation involved in shaping the material into a relatively small, complicated configuration. If a given strip of steel is subject to bending in a complicated manner, the strip would often become fractured during its bending.
SUMMARY OF THE INVENTION
With the above-noted difficulties of the prior art sliders in view, it is the primary object of the invention to provide an improved automatic locking slider having a locking member which is easy to bend to shape, yet highly resilient to retain the slider in locked position even under the influence of increased stresses.
According to the invention, there is provided an automatic locking slider of the class described comprising a slider body having an upper wing member and a lower wing member positioned in spaced, opposed relation and connected at one end by an integral neck portion to provide a substantially Y-shaped channel therebetween, a locking spring member formed from a strip of stainless steel and supported on said upper wing member, and a pull tab having a transversely extending trunnion pivotally disposed between said locking spring member and said upper wing member, said locking member having a first section secured to the slider body adjacent said neck portion and a second section including a locking prong movable into and out of said Y-shaped channel, said first section having a groove formed by cold press and being higher in the cold rolling modulus at an area adjacent to said groove than said second section.
The invention will be better understood from the following description taken with reference to the accompanying drawings which illustrate by way of example certain preferred embodiments which the invention may assume in practice.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an automatic locking slider provided in accordance with a preferred embodiment of the invention;
FIG. 2 is a perspective view of a locking member forming a part of the slider of FIG. 1;
FIG. 3 is an enlarged sectional view taken on the line III--III of FIG. 2;
FIG. 4 is a perspective view of a modified form of slider according to the invention; and
FIG. 5 is a perspective view of a locking member to be built into the slider of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and FIG. 1 in particular, there is shown an automatic locking slider 10 constructed in accordance with the invention, the slider 10 generally comprising a slider body 11 constituted by an upper wing member 12 and a lower wing member 13 connected together at one end in spaced, opposed relation by an integral neck portion 14 to provide a substantially Y-shaped channel 15 therebetween for the passage of rows of fastener elements (not shown). Flanges 16 and 17 extend inwardly from the upper and lower wing members 12, 13, respectively and serve to retain the fastener elements in the Y-shaped channel 15 during longitudinal movement of the slider 10 along a fastener (not shown) to open or close the latter in the well known manner.
Upon the upper wing member 12 at one or forward end adjacent the neck portion 14, there are provided a pair of opposed retaining lugs 18, 18' for retaining a locking spring member, later described, in cooperation with a supporting projection 19 extending upwardly from the outer surface of the wing 12.
A locking spring member designated at 20 and shown in particularity in FIG. 2 is operatively associated with a pull tab, later described, for releasably locking the slider 10 into position on the fastener. The locking spring member 20, which constitutes an important aspect of the invention, is made of a suitable resilient material such as stainless steel initially in the form of a blank strip, and consists of a first section 20a and a second section 20b which have different cold rolling moduli with a view to facilitating the bending or other shaping work of the blank and at the same time to affording increased resiliency and strength to a final form of locking member. The first section 20a is bent downwardly at substantially right angles and constitutes an arm 21 which is provided with an elongated groove 31 extending at the center and substantially throughout the length of the arm 21 and having at one end laterally projecting ears 22, 22'. The first section 20a is of a high cold rolling modulus at an area adjacent to the groove 31. The second section 20b is of a low cold rolling modulus, and is generally greater in width than the first section 20a or arm 21, and includes a flat seat portion 23 integral with the after end of the arm 21, a bearing portion 24 rising above the seat portion 23 for pivotally supporting a pull tab, a recess 25 formed in the back of the bearing portion 24 for receiving the supporting projection 19, and a locking prong 26 extending downwardly from the bearing portion 24 and adapted to pass through an aperture (not shown) in the upper wing 12 into the Y-shaped channel 15.
Designated at 27 is a pull tab having a transversely extending trunnion portion 28 which is, as shown in FIG. 1, interposed between the locking spring member 20 and the outer surface of the upper wing 12 and supported within the bearing portion 24 for pivotal movement of the pull tab 27 to actuate the locking member 20 in the well known manner.
There is provided an elongated recess 29 in the outer surface of the neck portion 14, which recess is configured to conform with the contour of the arm 21 of the locking member 20 and thus adapted to receive and anchor the arm 21 or first section 20a therein. To further ensure retention of the arm 21, there are provided a pair of opposed cavities 30, 30' for receiving the ears 22, 22' of the locking member 20.
The second section 20b of the locking member 20, which is lower in the cold rolling modulus at an area adjacent to the groove 31 than the first section 20a, is supported movably slightly in the vertical direction relative to the slider body, with the seat portion 23 borne against and retained by the retaining lugs 18, 18' and with the recess 25 engaged with the supporting projection 19.
FIG. 1 illustrates the slider 10 in its locked position wherein the pull tab 27 is flipped down flat against the upper wing 12 with the locking prong 26 urged by the tension in the locking spring member 20 into the channel 15 to engage in the space between adjacent fastener elements in a manner well known. As the pull tab 27 is rotated about the trunnion 28 and lifted against the tension of the locking member 20, the locking prong 26 is pulled out of engagement with the fastener elements, whereby the slider 10 is allowed to move therealong in a direction to open or close the fastener in the well known manner.
A preferred method of providing a locking spring member having two different cold rolling modulus sections or areas as above described, is to use a stainless steel strip of ordinary cold rolling modulus, and first bend a portion of the strip corresponding to the arm 21 or first section 20a to shape by cold press whereupon the pressure exerted by press creates an increase in the modulus at areas surrounding the groove 31 as shown by thickened oblique lines in FIG. 3. Thereafter, the remaining portions of the strip are bent to shape as desired. Since the arm 21 is not hardened at areas adjacent the opposite sides of the groove 31 and comparable in the cold rolling modulus to the second section 20b, the arm 21 can be punched out to shape easily by cutting along those unhardened areas. The locking spring member 20 may be further annealed to uniformity for enhanced spring quality. The resulting spring member 20 thus can store sufficient resiliency at the first section 20a or arm 21 to withstand severe stresses tending to pull the locking prong 26 out of engagement with the partner elements.
FIGS. 4 and 5 illustrate a modified form of slider 10 in which a locking spring member 32 is bent along a grooved portion 33 substantially into a U-shaped configuration, with an elongated locking prong 34 depending normally at substantially right angles to the plane of the slider body. Further detailed explanation of this modification will not be required, as the exact form and construction advanced herein do not constitute any positive part of the invention, the important features thereof being in the provisions of two different cold rolling modulus areas in the locking member 20, 32 for the purposes which have been described in connection with the first embodiment shown FIGS. 1, 2 and 3.
Although various minor modifications may be suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent warranted hereon, all such embodiments as reasonably and properly come within the scope of our contribution to the art. | A locking slider for sliding clasp fasteners is provided with a locking spring member for locking the slider into position on the fastener. The locking spring member is formed from a strip of stainless steel into a desired shape, the strip having an area higher in the cold rolling modulus than the remaining areas, such that the resiliency inter alia of the formed locking member is increased to an extent sufficient to withstand severe external stresses. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the Korean Patent Application No. 10-2014-0076794 filed on Jun. 23, 2014, which is hereby incorporated by reference as if fully set forth herein.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] Embodiments of the present invention relate to a touch panel, and more particularly, to a touch panel enabling both touch force sensing and touch point sensing, and an apparatus for driving thereof.
[0004] 2. Discussion of the Related Art
[0005] A touch panel is a type of input device that is included in image displaying devices such as Liquid Crystal Displays (LCDs), Field Emission Displays (FEDs), Plasma Display Panel (PDPs), Electroluminescent Displays (ELDs), Electrophoretic Display (EPDs), and Organic Light Emitting Devices (OLEDs), and allows a user to input information by pressing or touching a touch sensor of a screen with a finger, a pen or the like while a user looks at the screen of the image displaying device.
[0006] Recently, the touch panel is widely used for an input device of portable information devices such as smart phone and table PC, and also used for an input device of electronic equipment such as computer monitor, monitor and television.
[0007] According to a touch sensing method, the touch panel may be classified into a resistive type, a capacitance type, and an infrared sensing type. The capacitance touch panel has attracted great attentions owing to advantages of easy manufacturing method and sensitivity. The capacitance touch panel may be classified into a mutual capacitance type and a self capacitance type. In comparison to the self capacitance type touch panel, the mutual capacitance type touch panel is advantageous in that it enables a multi-touch input.
[0008] In case of a general touch panel, a touch point may be sensed by the use of finger or pen. However, it is difficult to sense a touch force, that is, touch pressure. Accordingly, U.S. Patent Application Publication Number 2014/0062933 published on Mar. 6, 2015 (hereinafter, referred to as “'933 Patent Document”) discloses a capacitance touch panel which senses both touch force and touch point.
[0009] As shown in FIG. 1 , in case of the capacitance touch panel disclosed in the '933 Patent Document, a touch force is sensed by a change of capacitance (Cm 1 ) in accordance with the decrease of distance in between a pair of force sensing electrodes 12 and 22 being overlapped with each other and being parallel to each other, and a touch point is sensed by a change of capacitance (Cm 2 ) in accordance with a fringe field in between a pair of point sensing electrodes 14 and 24 being not overlapped with each other and crossing each other.
[0010] However, the capacitance touch panel disclosed in the '933 Patent Document has the following disadvantages.
[0011] The force sensing electrodes 12 and 22 for sensing the touch force are separated from the point sensing electrodes 14 and 24 for sensing the touch point so that it causes a complicated electrode structure. In addition, a touch resolution is lowered due to the point sensing electrodes 14 and 24 crossing each other.
[0012] Also, efficiency of sensing the touch force is proportional to an area of the force sensing electrodes 12 and 22 facing each other. Thus, if the force sensing electrodes 12 and 22 are decreased in size so as to improve the touch resolution, the efficiency of sensing the touch force is lowered.
[0013] In order to improve the touch resolution, if the point sensing electrodes 14 and 24 are overlapped with each other, the capacitance (Cm 2 ) formed between the point sensing electrodes 14 and 24 is maintained at a constant value without regard to a touch of conductive object, whereby the efficiency of sensing the touch point is lowered.
SUMMARY
[0014] Accordingly, embodiments of the present invention are directed to a touch panel that substantially obviates one or more problems due to limitations and disadvantages of the related art, and an apparatus for driving thereof.
[0015] An aspect of embodiments of the present invention is directed to provide a touch panel which facilitates to improve both efficiency of sensing a touch force and efficiency of sensing a touch point, and an apparatus for driving thereof.
[0016] In one or more embodiments, a touch panel includes first electrodes and second electrodes separated from and intersecting the first electrodes. The first electrodes are applied with a touch driving pulse during a first sensing mode and a second sensing mode. The second electrodes sense a first touch sense signal responsive to the touch driving pulse in the first sensing mode. A subset of the second electrodes senses a second touch sense signal responsive to the touch driving pulse in the second sensing mode.
[0017] In one or more embodiments, the touch panel further includes an elastic dielectric member disposed between the first electrodes and the second electrodes.
[0018] In the first sensing mode, the second electrodes may sense the first touch sense signal based at least in part on a first capacitance between the first electrodes and the second electrodes responsive to the touch driving pulse. In the second sensing mode, the subset of the second electrodes may sense the second touch sense signal based at least in part on a second capacitance between the first electrodes and the subset of the second electrodes responsive to the touch driving pulse, where the second capacitance is less than the first capacitance.
[0019] In one or more embodiments, the second electrodes include touch sensing electrodes and adjacent electrodes adjacent to the touch sensing electrodes. The subset of the second electrodes may include the touch sensing electrodes but may exclude the adjacent electrodes. The adjacent electrodes may have an elongated rectangular shape in parallel with the touch sensing electrodes.
[0020] In the first sensing mode, the first touch sense signal from at least one of the touch sensing electrodes and one or more of the adjacent electrodes adjacent to said one of the touch sensing electrodes may be sensed to determine a force of the touch on the touch panel. In the second sensing mode, the second touch sense signal from said one of the touch sensing electrodes but excluding the adjacent electrodes adjacent to said one of the touch sensing electrodes may be sensed to determine a location of the touch on the touch panel.
[0021] In the first sensing mode, the one or more adjacent electrodes may be electrically coupled to said one of the touch sensing electrodes. In the second sensing mode, the one or more adjacent electrodes may be electrically decoupled from said one of the touch sensing electrodes. In the second sensing mode, the one or more adjacent electrodes may be in an electrically floating state.
[0022] In one or more embodiments, the adjacent electrodes include first adjacent electrodes and second adjacent electrodes, where each of the touch sensing electrodes is disposed between one of the first adjacent electrodes and one of the second adjacent electrodes. Said one of the first adjacent electrodes and said one of the second adjacent electrodes may be physically connected to each other. The touch panel may further include first routing lines and second routing lines. Each of the first routing lines may be connected to corresponding one of the touch sensing electrodes and each of the second routing lines may be connected to corresponding one of the first adjacent electrodes.
[0023] In one or more embodiments, responsive to determining the location of the touch in the second sensing mode, one or more selected electrodes from the first electrodes corresponding to the location of the touch are applied with the touch driving pulse to determine the force of the touch individually one at a time.
[0024] In one or more embodiments, responsive to failing to determine the location of the touch in the second sensing mode, a group of electrodes from the first electrodes are applied with the touch driving pulse to determine the force of the touch simultaneously.
[0025] In one or more embodiments, responsive to determining the force of the touch through the group of electrodes, one or more selected electrodes from the group of electrodes may be applied with the touch driving pulse to determine the location and the force of the touch individually one at a time. Responsive to failing to determine the force of the touch through the group of electrodes, the first electrodes may be applied with the touch driving pulse to determine the location of the touch in the second sensing mode.
[0026] Additional advantages and features of embodiments of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of embodiments of the invention. The objectives and other advantages of embodiments of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0027] It is to be understood that both the foregoing general description and the following detailed description of embodiments of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
[0029] FIG. 1 is a cross sectional view illustrating a simplified arrangement of electrodes in a touch panel disclosed in the '933 Patent Document;
[0030] FIG. 2 illustrates a simplified structure of a touch panel according to the first embodiment of the present invention;
[0031] FIG. 3 is a cross sectional view of the touch panel along I-I′ shown in FIG. 2 ;
[0032] FIG. 4 is a graph for explaining a change of capacitance in accordance with a distance of electrodes overlapping each other with an elastic dielectric member interposed therebetween, shown in FIG. 2 ;
[0033] FIGS. 5A and 5B are cross sectional views of the touch panel shown in FIG. 2 illustrating a change of capacitance among electrodes overlapping each other with an elastic dielectric member interposed in-between in a touch force sensing mode and a touch point sensing mode, respectively;
[0034] FIG. 6 illustrates a modified example of the touch panel according to the first embodiment of the present invention;
[0035] FIG. 7 illustrates a simplified structure of a touch panel according to the second embodiment of the present invention;
[0036] FIG. 8 is a cross sectional view of the touch panel along II-II′ shown in FIG. 7 ;
[0037] FIG. 9 illustrates a driving apparatus of a touch panel according to one embodiment of the present invention;
[0038] FIG. 10 is a block diagram for explaining a touch driving circuit of FIG. 9 ;
[0039] FIG. 11 illustrates a modified example of the touch panel in the driving apparatus according to one embodiment of the present invention; and
[0040] FIG. 12 is a flow chart for explaining a driving method of the touch panel according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0042] Advantages and features of the present invention, and implementation methods thereof will be clarified through following embodiments described with reference to the accompanying drawings. The present invention may, however, be embodied in 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 present invention to those skilled in the art. Further, the present invention is only defined by scopes of claims.
[0043] A shape, a size, a ratio, an angle, and a number disclosed in the drawings for describing embodiments of the present invention are merely an example, and thus, the present invention is not limited to the illustrated details. Like reference numerals refer to like elements throughout. In the following description, when the detailed description of the relevant known function or configuration is determined to unnecessarily obscure the important point of the present invention, the detailed description will be omitted. In a case where ‘comprise’, ‘have’, and ‘include’ described in the present specification are used, another part may be added unless ‘only˜’ is used. The terms of a singular form may include plural forms unless referred to the contrary. In construing an element, the element is construed as including an error region although there is no explicit description.
[0044] In description of embodiments of the present invention, when a structure (for example, an electrode, a line, a wiring, a layer, or a contact) is described as being formed at an upper portion/lower portion of another structure or on/under the other structure, this description should be construed as including a case where the structures contact each other and moreover, a case where a third structure is disposed therebetween.
[0045] In describing a time relationship, for example, when the temporal order is described as ‘after˜’, ‘subsequent˜’, ‘next˜’, and ‘before˜’ a case which is not continuous may be included unless ‘just’ or ‘direct’ is used.
[0046] It will be understood that, although the terms “first”, “second”, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention.
[0047] Features of various embodiments of the present invention may be partially or overall coupled to or combined with each other, and may be variously inter-operated with each other and driven technically as those skilled in the art can sufficiently understand. The embodiments of the present invention may be carried out independently from each other, or may be carried out together in co-dependent relationship.
[0048] Hereinafter, a touch panel according to the embodiment of the present invention and an apparatus for driving thereof will be described with reference to the accompanying drawings.
[0049] FIG. 2 illustrates a simplified structure of a touch panel according to the first embodiment of the present invention. FIG. 3 is a cross sectional view of the touch panel along I-I′ shown in FIG. 2 .
[0050] Referring to FIGS. 2 and 3 , a touch panel 100 according to the first embodiment of the present invention is disposed (or attached to) on a display panel of an image displaying device (not shown). The touch panel 100 according to the first embodiment of the present invention generates touch point sensing data and/or touch force sensing data in accordance with a user's touch, and provides the generated data to an external host system (not shown). For example, if a display panel is a liquid crystal display panel (or organic light emitting display panel) including an upper polarizing film, the touch panel 100 may be disposed on the upper polarizing film, or may be disposed between an upper substrate and the upper polarizing film. The touch panel 100 may include a first substrate 110 with a touch driving electrode (Tx), a second substrate 120 with a touch sensing electrode (Rx) and first and second dummy electrodes (Dxa, Dxb), and an elastic dielectric member 130 disposed between the first and second substrates 110 and 120 .
[0051] The first substrate 110 may be formed of a transparent plastic material. The first substrate 110 may be attached to an upper surface of display panel by the use of transparent adhesive (not shown).
[0052] The touch driving electrode (Tx) is provided in a first direction (X) on the first substrate 110 , wherein the touch driving electrode (Tx) is formed in a bar shape with a predetermined area. The touch driving electrode (Tx) is connected with a touch driving circuit (not shown) through a driving routing line (RL 1 ), and is supplied with a touch driving pulse from the touch driving circuit.
[0053] In the same manner as the first substrate 110 , the second substrate 120 may be formed of the transparent plastic material. The second substrate 120 and the first substrate 110 face each other, and the elastic dielectric member 130 is interposed between the first substrate 110 and the second substrate 120 . In addition, a cover window (not shown) may be attached to an upper surface of the second substrate 120 by the use of transparent adhesive.
[0054] The touch sensing electrode (Rx) is provided in a second direction (Y) on the second substrate 120 being overlapped with the touch driving electrode (Tx), and the touch sensing electrode (Rx) is formed in a bar shape with a predetermined area. In this case, with respect to a longitudinal direction, a width of the touch sensing electrode (Rx) is smaller than a width of the touch driving electrode (Tx). The touch sensing electrode (Rx) is connected with the touch driving circuit through a sensing routing line (RL 2 ), whereby the touch sensing electrode (Rx) is used as a touch point/force sensing electrode for sensing a touch point or touch force.
[0055] The first dummy electrode (Dxa) is formed in a bar shape with a predetermined area, and is provided in parallel to one side of the touch sensing electrode (Rx) along the second direction (Y) on the second substrate 120 being overlapped with the touch driving electrode (Tx). In this case, with respect to the longitudinal direction, the first dummy electrode (Dxa) may be provided at a predetermined interval from one side of the touch sensing electrode (Rx), and a width of the first dummy electrode (Dxa) may be smaller than a width of the touch driving electrode (Tx), or may be the same as a width of the touch sensing electrode (Rx). As the first dummy electrode (Dxa) is connected with the touch driving circuit through a first dummy routing line (RL 3 ), the first dummy electrode (Dxa) may be floating by the touch driving circuit or may be electrically connected with the touch sensing electrode (Rx) or sensing routing line (RL 2 ). In more detail, the first dummy electrode (Dxa) may be electrically floating in a touch point sensing mode, or the first dummy electrode (Dxa) may be electrically connected with the touch sensing electrode (Rx) in a touch force sensing mode. Accordingly, the first dummy electrode (Dxa) is used as a touch force sensing electrode for sensing the touch force, and the first dummy electrode (Dxa) is also used as a floating electrode to enable sensing the touch point.
[0056] The second dummy electrode (Dxb) is formed in a bar shape with a predetermined area, and the second dummy electrode (Dxb) is provided in parallel to the other side of the touch sensing electrode (Rx) along the second direction (Y) on the second substrate 120 being overlapped with the touch driving electrode (Tx). In this case, with respect to the longitudinal direction, the second dummy electrode (Dxb) may be provided at a predetermined interval from the other side of the touch sensing electrode (Rx), and a width of the second dummy electrode (Dxb) may be smaller than a width of the touch driving electrode (Tx), or may be the same as a width of the touch sensing electrode (Rx) or first dummy electrode (Dxa). As the second dummy electrode (Dxb) is connected with the touch driving circuit through a second dummy routing line (RL 4 ), the second dummy electrode (Dxb) may be maintained in the floating state by the touch driving circuit, or may be electrically connected with the touch sensing electrode (Rx). In more detail, the second dummy electrode (Dxb) may be electrically floating for the touch point sensing mode, or may be electrically connected with the touch sensing electrode (Rx) or sensing routing line (RL 2 ) for the touch force sensing mode. Accordingly, the second dummy electrode (Dxb) is used as a touch force sensing electrode for sensing the touch force, and the second dummy electrode (Dxb) is used as a floating electrode to enable sensing the touch point.
[0057] In FIGS. 2 and 3 , each of the first and second dummy electrodes (Dxa, Dxb) is formed in one bar shape, but is not limited to this shape. In order to improve a transmittance of light emitted from the display panel, each of the first and second dummy electrodes (Dxa, Dxb) may be formed in a line structure, a mesh structure or a ladder structure including a plurality of dummy electrodes electrically connected with one another, or may include a plurality of slits at fixed intervals or a plurality of openings arranged in a grid pattern.
[0058] The elastic dielectric member 130 is interposed between the first substrate 110 and the second substrate 120 . In this case, the elastic dielectric member 130 may be attached to an upper surface of the first substrate 110 or a lower surface of the second substrate 120 by the use of transparent adhesive. The elastic dielectric member 130 may be formed of a material with elasticity and high dielectric constant. For example, the elastic dielectric member 130 may be formed of PDMS (polydimethylsiloxane), acrylic or poly-urethane material, but not be limited to these materials. The elastic dielectric member 130 may be formed of any material with elasticity and high dielectric constant.
[0059] The elastic dielectric member 130 forms a capacitance (Cm 1 , Cm 2 , Cm 3 ) among the touch sensing electrode (Rx), each of the first and second dummy electrodes (Dxa, Dxb), and the touch driving electrode (Tx). Specifically, the elastic dielectric member 130 is changed in its elasticity by a user's touch force, and thus changed in its thickness, to thereby change the capacitance (Cm 1 , Cm 2 , Cm 3 ). In this case, the capacitance (Cm 1 , Cm 2 , Cm 3 ) may be changed in accordance with each distance among the touch sensing electrode (Rx), each of the first and second dummy electrodes (Dxa, Dxb), and the touch driving electrode (Tx), as shown in FIG. 4 . In this case, as the capacitance (Cm 1 , Cm 2 , Cm 3 ) is inversely proportional to each distance among the electrodes, the touch force may be sensed by a force level algorithm for modeling an increased variation of the capacitance (Cm 1 , Cm 2 , Cm 3 ) in accordance with the touch force.
[0060] As the elastic dielectric member 130 with elasticity and high dielectric constant is interposed between the first and second substrates 110 and 120 , a first touch sensor (Cm 1 ) for sensing the touch point or touch force is formed at an intersection of the touch driving electrode (Tx) and the touch sensing electrode (Rx). The first touch sensor (Cm 1 ) is formed by a dielectric constant of the elastic dielectric member 130 , and a capacitance based on an overlapping area between the touch driving electrode (Tx) and the touch sensing electrode (Rx) and a distance between the touch driving electrode (Tx) and the touch sensing electrode (Rx). In this case, an electric charge corresponding to a touch driving pulse supplied to the touch driving electrode (Tx) is charged in the first touch sensor (Cm 1 ), and the electric charge of the first touch sensor (Cm 1 ) is discharged to the touch sensing electrode (Rx). An amount of electric charge in the first touch sensor (Cm 1 ) varies according to whether or not there is a user's touch.
[0061] As shown in FIG. 5A , when the first dummy electrode (Dxa) is electrically connected with the touch sensing electrode (Rx) or sensing routing line (RL 2 ) in accordance with the touch force sensing mode, the first dummy electrode (Dxa) functions as the touch force sensing electrode which is identical to the touch sensing electrode (Rx), whereby a second touch sensor (Cm 2 ) for sensing the touch force is formed at an intersection between the touch driving electrode (Tx) and the first dummy electrode (Dxa).
[0062] The second touch sensor (Cm 2 ) is formed by a dielectric constant of the elastic dielectric member 130 , and a capacitance based on an overlapping area between the touch driving electrode (Tx) and the first dummy electrode (Dxa) and a distance between the touch driving electrode (Tx) and the first dummy electrode (Dxa). As shown in FIG. 4 , the capacitance of the second touch sensor (Cm 2 ) varies in accordance with the distance between the touch driving electrode (Tx) and the first dummy electrode (Dxa). In this case, an electric charge corresponding to a touch driving pulse (Tx_PWM) supplied to the touch driving electrode (Tx) is charged in the second touch sensor (Cm 2 ), and the electric charge of the second touch sensor (Cm 2 ) is discharged to the first dummy electrode (Dxa). An amount of electric charge in the second touch sensor (Cm 2 ) varies in accordance with the distance between the touch driving electrode (Tx) and the first dummy electrode (Dxa) by a user's touch force.
[0063] Meanwhile, as shown in FIG. 5B , when the first dummy electrode (Dxa) is electrically floating without being connected with the touch sensing electrode (Rx) in accordance with the touch point sensing mode, the capacitance (Cm 2 ) is not formed between the touch driving electrode (Tx) and the first dummy electrode (Dxa). Accordingly, the capacitance of the first touch sensor (Cm 1 ) formed between the touch driving electrode (Tx) and the touch sensing electrode (Rx) is changed in accordance with the touch by the use of conductive object, whereby it is possible to sense the touch point, and furthermore to improve sensing efficiency of the touch point.
[0064] As shown in FIG. 5A , when the second dummy electrode (Dxb) is electrically connected with the touch sensing electrode (Rx) or sensing routing line (RL 2 ) in accordance with the touch force sensing mode, the second dummy electrode (Dxb) functions as the touch force sensing electrode which is identical to the touch sensing electrode (Rx), whereby a third touch sensor (Cm 3 ) for sensing the touch force is formed at an intersection between the touch driving electrode (Tx) and the second dummy electrode (Dxb). The third touch sensor (Cm 3 ) is formed by a dielectric constant of the elastic dielectric member 130 , and a capacitance based on an overlapping area between the touch driving electrode (Tx) and the second dummy electrode (Dxb) and a distance between the touch driving electrode (Tx) and the second dummy electrode (Dxb). As shown in FIG. 4 , the capacitance of the third touch sensor (Cm 3 ) varies in accordance with the distance between the touch driving electrode (Tx) and the second dummy electrode (Dxb). In this case, an electric charge corresponding to a touch driving pulse (Tx_PWM) supplied to the touch driving electrode (Tx) is charged in the third touch sensor (Cm 3 ), and the electric charge of the third touch sensor (Cm 3 ) is discharged to the second dummy electrode (Dxb). An amount of electric charge in the third touch sensor (Cm 3 ) varies in accordance with the distance between the touch driving electrode (Tx) and the second dummy electrode (Dxb) by a user's touch force.
[0065] Meanwhile, as shown in FIG. 5B , when the second dummy electrode (Dxb) is electrically floating without being connected with the touch sensing electrode (Rx) in accordance with the touch point sensing mode, the capacitance (Cm 3 ) is not formed between the touch driving electrode (Tx) and the second dummy electrode (Dxb). Accordingly, the capacitance of the first touch sensor (Cm 1 ) formed between the touch driving electrode (Tx) and the touch sensing electrode (Rx) is changed in accordance with the touch by the use of conductive object, whereby it is possible to sense the touch point, and furthermore to improve sensing efficiency of the touch point.
[0066] Additionally, each of the touch driving electrode (Tx) and the touch sensing electrode (Rx) may be formed in a circular or diamond shape, and each of the first and second dummy electrodes (Dxa, Dxb) may be formed to surround the touch sensing electrode (Rx) on halves. Preferably, each of the electrodes (Tx, Rx, Dxa, Dxb) is formed in the bar shape in order to sufficiently secure the capacitance for sensing the touch point and the capacitance for sensing the touch force, as mentioned above.
[0067] The touch panel 100 according to the first embodiment of the present invention facilitates to improve the sensing efficiency of the touch point by electrically floating the first and second dummy electrodes (Dxa, Dxb) in accordance with the touch point sensing mode, and also to improve the sensing efficiency of the touch force by increasing the area of the force sensing electrode for sensing the touch force through the electrical connection between the touch sensing electrode (Rx) and the first and second dummy electrodes (Dxa, Dxb). Hence, a larger capacitance is charged between the touch driving electrode (Tx) and a combination of the touch sensing electrode (Rx) and the first dummy electrode (Dxa) and/or the second dummy electrode (Dxb) in the touch force sensing mode, compared to a capacitance charged between the touch driving electrode (Tx) and the touch sensing electrode (Rx) in the touch point sensing mode. Large capacitance charged between the touch driving electrode (Tx) and the combination of the touch sensing electrode (Rx) and the first dummy electrode (Dxa) and/or the second dummy electrode (Dxb) in the touch force sensing mode enables accurate sensing of touch force. In addition, less capacitance charged between the touch driving electrode (Tx) and the touch sensing electrode (Rx) in the touch point sensing mode enables enough fringe field to be formed between the touch driving electrode (Tx) and the touch sensing electrode (Rx) to allow accurate sensing of touch point (or whether a specific electrode is touched or not). Eventually, the touch panel 100 according to the first embodiment of the present invention enables to improve both the touch force sensing efficiency and the touch point sensing efficiency.
[0068] FIG. 6 illustrates a modified example of the touch panel according to the first embodiment of the present invention, wherein one side of the first dummy electrode is electrically connected with one side of the second dummy electrode. Hereinafter, only the first and second dummy electrodes will be described in detail as follows.
[0069] One side of the first dummy electrode (Dxa) is electrically connected with one side of the second dummy electrode (Dxb) through a dummy bridge electrode (Dxc).
[0070] The dummy bridge electrode (Dxc) is provided at a predetermined interval from one side of the touch sensing electrode (Rx) while being in parallel to one side of the touch sensing electrode (Rx), whereby the dummy bridge electrode (Dxc) is electrically connected with both one side of the first dummy electrode (Dxa) and one side of the second dummy electrode (Dxb). Accordingly, the dummy bridge electrode (Dxc) and the first and second dummy electrodes (Dxa, Dxb) are provided in shape of “⊂” or “⊃”.
[0071] Additionally, one side of the first dummy electrode (Dxa) is electrically connected with one side of the second dummy electrode (Dxb) through the dummy bridge electrode (Dxc), whereby it is possible to omit any one of the first and second dummy routing lines (RL 3 , RL 4 ). Accordingly, a width of edge in the touch panel 100 provided with the routing line is reduced so that a bezel width of the touch panel 100 is reduced.
[0072] FIG. 7 illustrates a simplified structure of a touch panel 200 according to the second embodiment of the present invention. FIG. 8 is a cross sectional view of the touch panel 200 along II-II′ shown in FIG. 7 .
[0073] As shown in FIG. 7 , a touch panel 200 according to the second embodiment of the present invention is obtained by providing the touch driving electrode (Tx) on a lower surface of the elastic dielectric member 130 , and providing the touch sensing electrode (Rx) and the first and second dummy electrodes (Dxa, Dxb) on an upper surface of the elastic dielectric member 130 in the aforementioned touch panel 100 according to the first embodiment of the present invention. That is, in case of the touch panel 200 according to the second embodiment of the present invention, the aforementioned first and second substrates 110 and 120 are removed from the touch panel 200 . Except that the first and second substrates 110 and 120 are removed from the touch panel 200 , the touch panel 200 according to the second embodiment of the present invention is identical in electrode structure to the touch panel 100 of FIG. 6 , whereby it is possible to sense both the touch point and the touch force, and to realize a thin profile of the touch panel by the simplified structure.
[0074] In FIGS. 7 and 8 , one side of the first dummy electrode (Dxa) is electrically connected with one side of the second dummy electrode (Dxb) through the dummy bridge electrode (Dxc), but is not limited to this structure. That is, it is possible to omit the dummy bridge electrode (Dxc). In this case, the electrode structure of the touch panel 200 according to the second embodiment of the present invention may be identical to the electrode structure of the touch panel 100 shown in FIG. 2 , whereby the touch driving electrode (Tx) may be formed on the lower surface of the elastic dielectric member 130 , and the touch sensing electrode (Rx) and the first and second dummy electrodes (Dxa, Dxb) may be formed on the upper surface of the elastic dielectric member 130 .
[0075] The lower surface of the touch panel 200 according to the second embodiment of the present invention, that is, the touch driving electrode (Tx) may be attached to the upper surface of the display panel by the use of transparent adhesive. The upper surface of the touch panel 200 according to the second embodiment of the present invention, that is, the touch sensing electrode (Rx) and the first and second dummy electrodes (Dxa, Dxb) may be covered with the cover window by the use of transparent adhesive.
[0076] In the aforementioned first and second embodiments of the present invention, each of the touch panels 100 and 200 includes the first and second dummy electrodes (Dxa, Dxb), but is not limited to this structure. According to a modified example of the present invention, each of the touch panels 100 and 200 may include the first and second dummy electrodes (Dxa, Dxb), wherein any one of the first and second dummy electrodes (Dxa, Dxb) may be electrically floating without regard to the sensing mode, and another thereof may be electrically floating or connected with the touch sensing electrode in accordance with the sensing mode. According to another modified example of the present invention, each of the touch panels 100 and 200 may include any one of the first and second dummy electrodes (Dxa, Dxb). In this case, it may cause the decrease in the area of electrode used as the touch sensing electrode for sensing the touch force in accordance with the touch force sensing mode, however, it also may cause the increase in the area of electrode used as the touch sensing electrode for sensing the touch point in accordance with the touch point sensing mode, to thereby improve the efficiency for sensing the touch point.
[0077] FIG. 9 illustrates a driving apparatus of touch panel according to one embodiment of the present invention. FIG. 10 is a block diagram for explaining a touch driving circuit of FIG. 9 .
[0078] Referring to FIGS. 9 and 10 , the driving apparatus of touch panel according to one embodiment of the present invention may include a touch panel 300 and a touch driving circuit 400 .
[0079] The touch panel 300 may include first to n-th touch driving electrodes (Tx 1 ˜Txn), an elastic dielectric member (See FIG. 2 ) disposed on the first to n-th touch driving electrodes (Tx 1 ˜Txn), and first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) disposed on the elastic dielectric member, and respectively overlapped and intersected with the respective first to n-th touch driving electrodes (Tx 1 ˜Txn).
[0080] The first to n-th touch driving electrodes (Tx 1 ˜Txn) are provided at fixed intervals in a first direction (X) on a touch sensing area 300 a of the touch panel 300 . The first to n-th touch driving electrodes (Tx 1 ˜Txn) are connected with a touch driving circuit 400 through a pad portion (PP) and corresponding driving routing line (RL 1 ) formed in a first edge of the touch panel 300 . The first to n-th touch driving electrode (Tx 1 ˜Txn) may be formed on the first substrate (See FIG. 2 ), or may be formed on the lower surface of the elastic dielectric member (See FIG. 7 ).
[0081] The elastic dielectric member may be formed of a material with elasticity and dielectric constant, and may be disposed on the first to n-th touch driving electrodes (Tx 1 Txn). This elastic dielectric member is the same as the elastic dielectric member 130 shown in FIGS. 2 and 3 , whereby a detailed description for the elastic dielectric member will be omitted.
[0082] The first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) are formed at fixed intervals in a second direction (Y) on the touch sensing area 300 a of the touch panel 300 , wherein the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) respectively intersect with the first to n-th touch driving electrodes (Tx 1 ˜Txn). The first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) may be formed on the second substrate (See FIG. 2 ), or may be formed on the upper surface of the elastic dielectric member (See FIG. 7 ).
[0083] Each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) may include the touch sensing electrode (Rx), first dummy electrode (Dxa) and second dummy electrode (Dxb).
[0084] The touch sensing electrode (Rx) is used as a touch point/force sensing electrode for sensing a touch point or touch force. The touch sensing electrode (Rx) is connected with the touch driving circuit 400 through the pad portion (PP) and sensing routing line (RL 2 ) formed in a second edge of the touch panel 300 . The touch sensing electrode (Rx) is identical to the touch sensing electrode (Rx) shown in FIGS. 2 and 3 , wherein a detailed description for the touch sensing electrode (Rx) will be omitted.
[0085] The first dummy electrode (Dxa) may be used only as the touch force sensing electrode for sensing the touch force. The first dummy electrode (Dxa) is connected with the touch driving circuit 400 through the pad portion (PP) and first dummy routing line (RL 3 ) formed in the second edge of the touch panel 300 . That is, the first dummy electrode (Dxa) for each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) may be electrically floating by the touch driving circuit 400 , or may be electrically connected with the touch sensing electrode (Rx) or sensing routing line (RL 2 ). The first dummy electrode (Dxa) is identical to the first dummy electrode (Dxa) shown in FIGS. 2 and 3 , whereby a detailed description for the first dummy electrode (Dxa) will be omitted.
[0086] The second dummy electrode (Dxb) may be used only as the touch force sensing electrode for sensing the touch force. The second dummy electrode (Dxb) is connected with the touch driving circuit 400 through the pad portion (PP) and second dummy routing line (RL 4 ) formed in the second edge of the touch panel 300 . That is, the second dummy electrode (Dxb) for each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) may be electrically floating by the touch driving circuit 400 , or may be electrically connected with the touch sensing electrode (Rx) or sensing routing line (RL 2 ). The second dummy electrode (Dxb) is identical to the second dummy electrode (Dxb) shown in FIGS. 2 and 3 , whereby a detailed description for the second dummy electrode (Dxb) will be omitted.
[0087] The touch driving circuit 400 is provided on a flexible circuit film 500 attached to the pad portion (PP) of the touch panel 300 , and is connected with each of the routing lines (RL 1 , RL 2 , RL 3 , RL 4 ) through the pad portion (PP). Alternatively, the touch driving circuit 400 may be provided on a printed circuit board (not shown). In this case, the touch driving circuit 400 may be connected with each of the routing lines (RL 1 , RL 2 , RL 3 , RL 4 ) through a flexible circuit film (not shown) connected between the printed circuit board and the pad portion (PP) of the touch panel 300 .
[0088] The touch driving circuit 400 supplies a touch driving pulse (Tx_PWM) to each of the first to n-th touch driving electrodes (Tx 1 ˜Txn), and also senses a touch sense signal indicating a change of capacitance through each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm). For example, the touch driving circuit 400 drives the touch panel 300 by a time division method in accordance with the touch point sensing mode or touch force sensing mode, to thereby generate touch point sensing data (Pdata) or touch force sensing data (Fdata).
[0089] For the touch point sensing mode, after the touch driving circuit 400 electrically floats the first and second dummy electrodes (Dxa, Dxb) for each of the plurality of touch sensing electrode groups (Rx_G 1 ˜Rx_Gm), the touch driving circuit 400 sequentially supplies the touch driving pulse (Tx_PWM) to each of the first to n-th touch driving electrodes (Tx 1 ˜Txn), and simultaneously senses the touch sense signal indicating the change of charge amount in the first touch sensor (Cm 1 , See FIG. 5B ) through the touch sensing electrode (Rx) for each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm), to thereby generate touch point sensing data (Pdata).
[0090] For the touch force sensing mode, after the touch driving circuit 400 electrically connects the first and second dummy electrodes (Dxa, Dxb) to the touch sensing electrode (Rx) in a unit of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm), the touch driving circuit 400 sequentially supplies the touch driving pulse (Tx_PWM) to each of the first to n-th touch driving electrodes (Tx 1 ˜Txn), and simultaneously senses the touch sense signal indicating the change of charge amount in the first to third touch sensors (Cm 1 , Cm 2 , Cm 3 ) through the touch sensing electrode (Rx) for each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm), to thereby generate touch force sensing data (F data).
[0091] The touch driving circuit 400 according to one embodiment of the present invention may include a timing generating part 410 , a driving pulse supplying part 420 , an electrode connecting part 430 , a sensing part 440 and a sensing data processing part 450 . The touch driving circuit 400 of the above structure may be integrated as one ROIC (Readout Integrated Circuit) chip. However, the sensing data processing part 450 may be implemented as MCU (Micro Controller Unit) of host system without being integrated with the ROIC chip.
[0092] The timing generating part 410 generates a sensing start signal (PHT) in response to a touch mode signal (TMS) supplied from the MCU of host system, and controls a driving timing for each of the driving pulse supplying part 420 and the sensing part 440 . In this case, the touch mode signal (TMS) may be any one selected among a touch point sensing mode signal, a touch force sequential sensing mode signal, a touch force partial sensing mode signal and a touch force group sensing mode signal. Accordingly, the timing generating part 410 may generate touch control signals including sensing start signal (PHT), Tx channel setup signal, electrode connection signal (ECS), Rx channel setup signal and touch report synchronization signal (TRSS) on the basis of touch mode signal (TMS).
[0093] The driving pulse supplying part 420 supplies the touch driving pulse (Tx_PWM) to the touch driving electrode (Tx 1 ˜Txn) on the basis of sensing start signal (PHT) and Tx channel setup signal supplied from the timing generating part 410 . That is, the driving pulse supplying part 420 selects a TX channel, to which the touch driving pulse (Tx_PWM) is to be output, in response to the TX channel setup signal of the timing generating part 410 , generates the touch driving pulse (Tx_PWM) synchronized with the sensing start signal (PHT), and supplies the touch driving pulse (Tx_PWM) to the corresponding touch driving electrode (Tx 1 ˜Txn) through the driving routing line (Tx 1 ˜Txn) connected with the selected Tx channel. For example, in case of the touch point sensing mode or touch force sequential sensing mode, the driving pulse supplying part 420 may sequentially supply the touch driving pulse (Tx_PWM) to the first to n-th touch driving electrodes (Tx 1 ˜Txn). In case of the touch force partial sensing mode, the driving pulse supplying part 420 may sequentially supply the touch driving pulse (Tx_PWM) to the plurality of touch driving electrodes partially selected among the first to n-th touch driving electrodes (Tx 1 ˜Txn). The touch force partial sensing mode herein refers to a mode in which one or more touch driving electrodes (TX) are driven individually one at a time. In case of the touch force group sensing mode, the driving pulse supplying part 420 may sequentially supply the touch driving pulse (Tx_PWM) to a plurality of groups, wherein each group may include the two or more touch driving electrodes among the first to n-th touch driving electrodes (Tx 1 ˜Txn). The touch force group sensing mode herein refers to a mode in which touch driving electrodes (TX) in a group are driven simultaneously.
[0094] In response to the electrode connection signal (ECS) supplied from the timing generating part 410 , the electrode connecting part 430 electrically floats the first and second dummy electrodes (Dxa, Dxb) in a unit of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) or electrically connects the first and second dummy electrodes (Dxa, Dxb) to the touch sensing electrode (Rx). For example, the electrode connecting part 430 electrically floats the first and second dummy routing lines (RL 3 , RL 4 ) for each of the first to m-th touch sensing electrodes groups (Rx_G 1 ˜Rx_Gm) in response to the electrode connection signal (ECS) in accordance with the touch point sensing mode, whereby the first and second dummy electrodes (Dxa, Dxb) are electrically floating in a unit of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm). Also, the electrode connecting part 430 electrically connects the first and second dummy routing lines (RL 3 , RL 4 ) to the sensing routing line (RL 2 ) in a unit of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) in response to the electrode connection signal (ECS) in accordance with the touch force sequential sensing mode, the touch force partial sensing mode and the touch force group sensing mode.
[0095] The sensing part 440 generates a sensing signal obtained by sensing the change of charge amount in the touch sensor through the touch sensing electrode (Rx) for each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) connected with the electrode connecting part 430 on the basis of sensing start signal (PHT) and Rx channel setup signal, and generates touch point sensing data (Pdata) or touch force sensing data (Fdata) by an analog-to-digital conversion of the sensing signal. For example, in case of the touch point sensing mode, the sensing part 440 senses the change of charge amount in the touch sensor (Cm 1 , See FIG. 5B ) through the touch sensing electrode (Rx) for each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm), and generates the touch point sensing data (Pdata) based on the change of charge amount. Also, in case of the touch force sequential sensing mode, touch force partial sensing mode and touch force group sensing mode, the sensing part 440 senses the change of charge amount in the touch sensor (Cm 1 , Cm 2 and Cm 3 , See FIG. 5A ) through the first and second dummy electrodes (Dxa, Dxb) and touch sensing electrode (Rx) for each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm), and generates the touch force sensing data (Fdata) based on the change of charge amount.
[0096] The sensing part 440 according to one embodiment of the present invention may generate the sensing signal by amplifying a difference of the signals from the adjacent two Rx channels, and sampling the amplified signal. The sensing part 440 according to one embodiment of the present invention amplifies the difference between the signals of the adjacent two touch sensing electrodes and reduces noise ingredient input due to a parasitic capacitance of the touch panel 300 , to thereby improve a signal-to-noise ratio. To this end, the sensing part 440 according to one embodiment of the present invention may include an integrator comprising a differential amplifier.
[0097] The sensing part 440 according to another embodiment of the present invention may compare a signal received from one Rx channel with a reference voltage, and may generate the sensing signal based on the comparison result. In this case, the sensing part 440 according to another embodiment of the present invention may include a comparator.
[0098] The sensing data processing part 450 receives the touch point sensing data (Pdada) or touch force sensing data (Fdata) from the sensing part 440 , sequentially stores the received data in an internal memory, and transmits the touch point sensing data (Pdata) or touch force sensing data (Fdata) stored in the internal memory to the MCU of host system in response to the touch report synchronization signal (TRSS) in accordance with a preset interface method.
[0099] The MCU of host system receives the touch point sensing data (Pdata) from the sensing data processing part 450 , compares the received touch point sensing data (Pdata) with a preset point sensing threshold value to determine whether or not there is a user's touch and the touch point coordinates. In one aspect, the MCU determines that a coordinate of the touch panel is touched, if the touch point sensing data corresponding to the coordinate is larger than the point sensing threshold value. That is, the MCU calculates the touch point coordinates value (XY coordinates) based on point information (X-coordinate) of the touch sensing electrode (Rx) with the touch point sensing data (Pdata) and point information (Y-coordinate) of the touch driving electrode (Tx) being driven. In addition, the MCU may calculate the number of touch points from the calculated touch point coordinates, calculate the number of times being touched by counting the calculated number of touch points in a unit time period, or calculate a touch continuance time in a unit time period.
[0100] Also, the MCU of host system receives the touch force sensing data (Fdata) from the sensing data processing part 450 , compares the received touch force sensing data (Fdata) with a preset force sensing threshold value, and calculates the touch point coordinates and a size of touch force by the use of touch force sensing data, if the touch force sensing data is larger than the force sensing threshold value. That is, the MCU calculates the touch force coordinates value (XY coordinates) based on point information (X-coordinate) of the touch sensing electrode (Rx) with the touch force sensing data (Fdata) and point information (Y-coordinate) of the touch driving electrode (Tx) being driven, and also calculates the size of touch force based on a size of the touch force sensing data (Fdata).
[0101] Additionally, the touch driving circuit 400 may comprise a touch MCU which calculates whether or not there is a user's touch, the touch point coordinates and the size of touch force by the use of touch point sensing data (Pdata) and/or touch force sensing data (Fdata), and transmits the calculated results to the MCU. In this case, the MCU of the host system may only execute an application program linked to the touch point coordinates and the size of touch force provided from the touch MCU of host system.
[0102] Meanwhile, as shown in FIGS. 6 and 11 , each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) may further include the dummy bridge electrode (Dxc) for electrically connecting one side of the first dummy electrode (Dxa) with one side of the second dummy electrode (Dxb). In this case, one side of the first dummy electrode (Dxa) is electrically connected with one side of the second dummy electrode (Dxb) through the dummy bridge electrode (Dxc) in a unit of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm), whereby any one of the first and second dummy routing lines (RL 3 , RL 4 ), for example, the second dummy routing line (RL 4 ) may be omitted. Accordingly, the electrode connecting part 430 of the touch driving circuit 400 electrically floats the first dummy routing line (RL 3 ) in response to the electrode connection signal (ECS) in accordance with the touch point sensing mode, whereby the electrode connecting part 430 electrically floats the first and second dummy electrodes (Dxa, Dxb) for each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm). The electrode connecting part 430 electrically connects the first dummy routing line (RL 3 ) with the sensing routing line (RL 2 ) in response to the electrode connection signal (ECS) in accordance with the touch force sequential sensing mode, the touch force partial sensing mode and the touch force group sensing mode, whereby the first and second dummy electrodes (Dxa, Dxb) are electrically connected with the corresponding touch sensing electrode (Rx) in a unit of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm).
[0103] FIG. 12 is a flow chart for explaining a driving method of the touch panel according to one embodiment of the present invention.
[0104] In connection with FIGS. 9 and 10 , FIG. 12 is a flow chart for explaining the driving method of the touch panel according to one embodiment of the present invention.
[0105] First, after the touch driving circuit 400 electrically floats the first and second dummy electrodes (Dxa, Dxb) for each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) in accordance with the touch point sensing mode, the touch driving circuit 400 sequentially supplies the touch driving pulse (Tx_PWM) to each of the first to n-th touch driving electrodes (Tx 1 ˜Txn), and simultaneously senses the change of charge amount in the first touch sensor (Cm 1 , See FIG. 5B ) through the touch sensing electrode (Rx) for each of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm), to thereby generate the touch point sensing data (Pdata) (S 100 ).
[0106] For the touch point sensing mode, the MCU determines whether or not there is the touch point sensing on the basis of preset point sensing threshold value and touch point sensing data (Pdata) supplied from the touch driving circuit 400 (S 200 ). Based on the determination result, if there is the touch point sensing (′Yes' of S 200 ), touch point area information is generated, and the touch force partial sensing mode signal is generated and is supplied to the touch driving circuit 400 .
[0107] Thereafter, after the touch driving circuit 400 electrically connects the first and second dummy electrodes (Dxa, Dxb) to the touch sensing electrode (Rx) in a unit of the touch sensing electrode group (Rx_G 1 ˜Rx_Gm) corresponding to the touch point area information in response to the touch force partial sensing mode signal and the touch point area information supplied from the MCU, the touch driving circuit 400 sequentially supplies the touch driving pulse (Tx_PWM) to one or more of the touch driving electrode (Tx 1 ˜Txn) corresponding to the touch point area information individually one at a time, and simultaneously senses the change of charge amount in the first to third touch sensors (Cm 1 , Cm 2 and Cm 3 , See FIG. 5A ) through the touch sensing electrode (Rx) of the corresponding touch sensing electrode group (Rx_G 1 ˜Rx_Gm), to thereby generate the touch force sensing data (Fdata) (S 110 ).
[0108] For the touch force partial sensing mode, the MCU determines whether or not there is the touch force sensing on the basis of touch force sensing data (Fdata) and preset force sensing threshold value (S 210 ). Based on the determination result, if there is the touch force sensing (‘Yes’ of S 210 ) by the touch force sensing data (Fdata), the touch point coordinates based on the touch point sensing data (Pdata) and the size of touch force are calculated and are supplied to the host system (S 220 ). Meanwhile, if there is no touch force sensing (‘No’ of S 210 ) by the touch force sensing data (Fdata), the touch point coordinates based on the touch point sensing data (Pdata) generated by the prior touch point sensing mode is calculated and is provided to the host system (S 230 ).
[0109] In the step S 200 of the touch point sensing mode, if the MCU determines that there is no touch point sensing (‘No’ of S 200 ), the touch force group sensing mode signal is generated and is provided to the touch driving circuit 400 .
[0110] After the touch driving circuit 400 electrically connects the first and second dummy electrodes (Dxa, Dxb) to the touch sensing electrode (Rx) in a unit of the first to m-th touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) in response to the touch force group sensing mode signal supplied from the MCU, the touch driving circuit 400 sequentially supplies the touch driving pulse (Tx_PWM) to the plurality of touch driving electrode groups, wherein each touch driving electrode group comprises the two or more touch driving electrodes that are supplied with the touch driving pulse simultaneously, and senses the change of charge amount in the first to third touch sensors (Cm 1 , Cm 2 and Cm 3 , See FIG. 5A ) through the touch sensing electrode (Rx) of the corresponding touch sensing electrode group (Rx_G 1 ˜Rx_Gm), to thereby generate the touch force sensing data (Fdata) (S 120 ).
[0111] For the touch force group sensing mode, the MCU determines whether or not there is the touch force sensing on the basis of touch force data (Fdata) and force sensing threshold value (S 240 ). Based on the determination result, if there is the touch force sensing (‘Yes’ of S 240 ) by the touch force sensing data (Fdata), touch force area information based on the touch force sensing data (Fdata) is generated, and the touch force partial sensing mode signal is generated and supplied to the touch driving circuit 400 .
[0112] After the touch driving circuit 400 electrically connects the first and second dummy electrodes (Dxa, Dxb) to the touch sensing electrode (Rx) in a unit of the touch sensing electrode group (Rx_G 1 ˜Rx_Gm) corresponding to the touch force area information in response to the touch force partial sensing mode signal and the touch force area information supplied from the MCU, the touch driving circuit 400 sequentially supplies the touch driving pulse (Tx_PWM) to the touch driving electrode (Tx 1 ˜Txn) corresponding to the touch force area information individually one at a time, and senses the change of charge amount in the first to third touch sensors (Cm 1 , Cm 2 and Cm 3 , See FIG. 5A ) through the touch sensing electrode (Rx) of the corresponding touch sensing electrode group (Rx_G 1 ˜Rx_Gm), to thereby generate the touch force sensing data (Fdata) (S 130 ).
[0113] For the touch force partial sensing mode, the MCU calculates the touch point coordinates and the size of touch force, if touch force sensing data (Fdata) supplied from the touch driving circuit 400 is larger than the preset force sensing threshold value, and provides the calculated touch point coordinates and the size of touch force to the host system (S 250 ).
[0114] In the step S 240 of the touch force group sensing mode, if the MCU determines that there is no touch force sensing (′No′ of S 240 ), the MCU generates the touch point sensing mode signal for the touch point sensing mode of the step S 100 , and supplies the generated signal to the touch driving circuit 400 .
[0115] In the aforementioned apparatus and method for driving the touch panel according to one embodiment of the present invention, each of the touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) of the touch panel 300 includes the first and second dummy electrodes (Dxa, Dxb), but is not limited to this structure. According to a modified example, each of the touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) may include the first and second dummy electrodes (Dxa, Dxb), wherein any one of the first and second dummy electrodes (Dxa, Dxb) may be electrically floating without regard to the sensing mode, and another thereof may be electrically floating or connected with the touch sensing electrode in accordance with the sensing mode. According to another modified example, each of the touch sensing electrode groups (Rx_G 1 ˜Rx_Gm) may include any one of the first and second dummy electrodes (Dxa, Dxb). In this case, it may cause the decrease in the area of electrode used as the touch sensing electrode for sensing the touch force in accordance with the touch force sensing mode, however, it also may cause the increase in the area of electrode used as the touch sensing electrode for sensing the touch point in accordance with the touch point sensing mode, to thereby improve the efficiency for sensing the touch point.
[0116] For the touch point sensing, the first and second dummy electrodes (Dxa, Dxb) are electrically floating, and then the touch point sensing mode is carried out so that it is possible to improve the efficiency for the touch point sensing. For the touch force sensing, the area of the sensing electrode is increased by electrically connecting the first and second dummy electrodes (Dxa, Dxb) with the touch sensing electrode (Rx), and then the touch force sensing mode is carried out so that it is possible to improve the efficiency for the touch force sensing. Specifically, the touch point sensing and the touch force sensing are carried out in the time division driving method, wherein the touch force sensing is carried out dividedly by the touch force group sensing and the touch force partial sensing, whereby it is possible to overcome a problem of the increase in touch driving time caused by the time division driving method.
[0117] According to the embodiments of the present invention, the area of the touch sensing electrode overlapped with the touch driving electrode is adjusted in accordance with the touch point sensing and the touch force sensing so that it is possible to improve both touch point sensing efficiency and touch force sensing efficiency.
[0118] Also, even though the time division driving method is used for the touch point sensing and the touch force sensing, the partial sensing or group sensing is selectively carried out so that it is possible to overcome the problem of the increase in touch driving time caused by the time division driving method.
[0119] It will be apparent to those skilled in the art that various modifications and variations can be made to embodiments of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | Embodiments relate to a touch panel and a method of operating the touch panel. The touch panel includes first electrodes and second electrodes separated from and intersecting the first electrodes. The first electrodes are applied with a touch driving pulse during a first sensing mode and a second sensing mode. The second electrodes sense a first touch sense signal responsive to the touch driving pulse in the first sensing mode. A subset of the second electrodes senses a second touch sense signal responsive to the touch driving pulse in the second sensing mode. | 6 |
This invention is a continuation-in-part of Ser. No. 07/513,539 filed Apr. 24, 1990, now U.S. Pat. No. 5,091,449 which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates to preparing stable suspensions of particulate materials.
Suspending mediums are commonly used for oil field additives, lubricants, coatings and paints. The industry goal has been, and still is, to improve the stability of these suspending mediums to extend the shelf life of products which contain suspended particulate materials. Settling out of the suspended particulate materials is a pronounced problem with materials which have high specific gravities such as tin or zinc particles. Those suspensions which do resist settling tend to be too viscous to pour.
Attempts to meet the above stated goals have been made in the art. Such efforts have employed a wide variety of agents including mixtures of organophyllic clays and water or oils, and polyethylene and mineral oil. Although these suspending mediums or compositions individually and collectively have improved on the art, the ultimate goal of providing an ideal suspension, i.e. one which resist settling, is pourable, easy to manufacture and is useable over a wide temperature range, remains to be solved.
SUMMARY OF THE INVENTION
It is a general object of this invention, to provide a suspension which resists settling and is readily pourable.
It is also another object of this invention to provide a process for forming stable liquid suspensions which are resistant to settling and are readily pourable.
In accordance with the present invention a stable liquid suspension is provided comprising an oil, an oil soluble resin and a non oil soluble particulate material selected from the group consisting of lime (calcium oxide in its various forms such as quicklime, hydrated lime, and hydraulic lime), sodium bicarbonate (NaHCO 3 ), sodium carbonate (Na 2 CO 3 ), molybdenum disulfide (MoS 2 ), sodium hydroxide (NaOH), graphite, zinc, tin, quebracho, lignin, lignite, caustisized lignite, lignosulfonate, chrome lignosulfonate, napthalenesulfonate, uintahite (gilsonite), and polyvinylalcohol.
In accordance with another embodimemt of the present invention there is also provided a method for forming a stable liquid suspension comprising mixing the following constituents: an oil, an oil soluble resin and a non oil soluble particulate material selected from the group consisting of lime (calcium oxide in its various forms such as quicklime, hydrated lime, and hydraulic lime), sodium bicarbonate (NaHCO 3 ), sodium carbonate (Na 2 CO 3 ), molybdenum disulfide MoS 2 , sodium hydroxide (NaOH), graphite, zinc, tin, quebracho, lignin, lignite, caustisized lignite, lignosulfonate, chrome lignosulfonate, napthalenesulfonate, uintahite (gilsonite), and polyvinylalcohol, in a manner which facilitates forming a stable liquid suspension.
DETAILED DESCRIPTION OF THE INVENTION
We have discovered that a very stable suspension may be formed by mixing a suitable oil, suitable oil soluble resin, and at least one non oil soluble particulate material. We originally developed this suspension for suspending water soluble polymer but have subsequently discovered that the suspending medium is capable of suspending a variety of other very different compounds. Surprisingly, the suspension medium is able to suspend particulate material having high densities, such as molybdenum disulfide, lime, zinc and tin. Further, the composition does not generally require additional processing in order to be used. Because of its exceptional stability the liquid suspension of the invention can be prepared and shipped to customers ready to use and does not need to be remixed before use in the field.
The oils useful in the practice of this invention broadly include hydrocarbon oils including but not limited to vegetable oils, crude oil, diesel oils, kerosene, pentane, decane, soybean oil, corn oil and combinations of two or more thereof. However, the preferred oils for purposes of this invention are kerosene, diesel oil, light diesel oil, heating oil, mineral oil, end iso-paraffins. Most particulary preferred are the iso-paraffins including but not limited to tetradecane, hexadecane, dodecane, mixed iso-paraffins (such as mixed C 13 -C 14 iso-paraffins), C 14 1 iso-paraffins, and C 16 iso-paraffins.
Generally, oil soluble resins are useful in the practice of this invention. Examples of suitable oil soluble resins are those selected from the group consisting of styrene-isoprene copolymers, hydrogenated styrene-isoprene block copolymers, styrene ethylene/propylene block copolymers, styrene isobutylene copolymers, styrene butadiene copolymers, polybutylene and polystyrene, polyethylene-propylene copolymers, include copolymers and block copolymers such as poly(styrene-co-isoprene), hydrogenated block-copoly(styrene/isoprene), block-copoly(styrene/ethylene/propylene), poly(styrene-co-isobutylene), copolymer(styrene-co-butadiene), polybutylene, polystyrene, copolymer(polyethylene-co-propylene), and combinations of two or more thereof. These oil soluble resins should have a molecular weight in tile range of from about 40,000 to about 100,000. Preferred, however, are block copolymers, examples of which include but are not limited to block-copoly(styrene/ethylene/propylene), hydrogenated block-copoly(styrene/isoprene) and block-copoly(styrene/butadiene). Most particularly preferred are hydrogenated (styrene-isoprene) copolymers and styrene-butadiene copolymers examples of which include but are not limited to materials sold under the trademarks "BARARESIN VIS"(trademark of Baroid Corporation), "SHELLVIS 40" and "SHELLVIS 50" (both trademarks of Shell Chemical Company).
Suitable non oil soluble particulate materials for suspending in the liquid suspension medium are particles which are not soluble in the suspending medium. It is preferred that the average diameter of the particles be in the range of from about 2000 microns to about 0.1 microns. It is also preferred that the particulate materials have a density of in the range of from about 1.5 g/cm 3 to about 7 g/cm 3 . It is currently believed that the more dense particulate materials will be suspended for longer periods of time if the particle size of these materials is reduced in proportion to the materials' increasing density. For example, tin can be suspened for longer periods of time if the particle size of the tin particles is less than 100 microns in size. As shown in the Examples tin can be susupended in excess of 30 days without settling occurring with a particle size of less than 100 microns. Examples of suitable non oil soluble particulate materials for the practice of the present invention include but are not limited to particles selected from the group consisting of lime (calcium oxide in its various forms such as quicklime, hydrated lime, and hydraulic lime), sodium bicarbonate (NaHCO 3 ), sodium carbonate (Na 2 CO 3 ), molybdenum disulfide (MoS2), sodium hydroxide (NaOH), graphite, zinc, tin, quebracho, lignin, lignite, caustisized lignite, lignosulfonate, chrome lignosulfonate, napthalenesulfonate, uintahite sulfonated asphalt, sulfomethylated tannin (gilsonite), and polyvinylalcohol. As discussed above the choice of the appropriate particle size for the particular particulate material in each suspension can be readily determined by systematicly testing a variety of particle sizes in the suspending medium to achieve an optimum stablity.
The ranges of the ingredients listed above useful in the practice of this invention are as shown in Table 1 below.
TABLE 1______________________________________Composition Broad Preferred MostComponents.sup.(b) (%).sup.(a) (%) Preferred (%)______________________________________Oil 40-95 55-60 57-59Resin 0.2-10 1.8-5 2-2.5Non oil soluble 3-60 37-45 38-40ParticulateMaterial______________________________________ .sup.(a) All weights in Table I are in weight percent wherein the total weight percent totals 100 weight percent. .sup.(b) The ranges of the composition components shown in Table I are al physical mixtures.
The mixing conditions for carrying out the practice of the invention are as follows: The temperature is generally in the range of about-10° C. to about 200° C., with a preferred range of about 0° C. to about 150° C., and a most preferred range of about 60° C. to about 70° C. The mixing time is generally in the broad range of about 0.05 hours to about 200 hours, with a preferred range of about 0.25 hours to about 20 hours, and a most preferred range of about 1 hour to about 2 hours. It is noted that the mixing time is generally inversely proportional to the reaction temperature i.e., the lower the temperature the more time is required.
In one embodiment, the process of this invention comprises introducing a suitable oil into a suitable mixing device and adding a suitable resin to the oil in the mixing device. The oil-resin mixture is then mixed for about 30-45 minutes at a temperature range of about 60° C. to about 70° C. To this oil-resin mixture is then added a suitable non oil soluble particulate material.
The end product of this process is a stable liquid suspension which can then be collected by any technique known in the art. While the order of mixing is not a critical aspect of this invention, it is preferred to add the oil first and non oil soluble particulate material last.
The addition of an antioxidant, a surfactant, a biocide, or hydrophobic fumed silica to these basic ingredients is an option which can be exercised by those of skill in the art. When added hydrophobic fumed silica can be in an amount in the range of up to 10 weight percent.
The product of this invention normally has a gel strength that is capable of suspending particulate matter. Additionally, this gel strength develops very rapidly or almost immediately and is of the type referred to in the art as flat gels. By this is meant that unlike normal gels, its gel strength stays constant or increases only slightly with time and that it has desirable fragile properties evidenced by the ease with which it pours.
The product of this Invention is primarily tested by observation for syneresis, pour point, and stability over a wide temperature range. Syneresis can be measured by means of a ruler or other such graduated device. This can be accomplished by inserting the ruler or graduated device through the clear liquid portion of the suspension until it contacts the interface that separates this portion, from the layer containing suspended solids. The thickness of the clear liquid layer, the measure of syneresis, can then be determined directly on the ruler or graduated device.
The following examples further illustrate the various aspects of this invention.
EXAMPLE 1
This composition contains the following components:
______________________________________light isoparrafin oil (1) 560 goil soluble resin (2) 20 gsulfonated asphalt (3) 387 gTotal 967 g______________________________________ (1) A C.sub.13 -C.sub.14 isoparaffin mixture available under the brand "SOLTROL 170" (0.778 g/ml), from Phillips Petroleum Company. (2) A hydrogenated styreneisoprene copolymer available under the brand "SHELL VIS 40", from Shell Chemical Company. (3) Available under the brand "SOLTEX", from Phillips Petroleum Company.
The oil soluble resin was sheared into the light isoparrafin oil with a Ross mixer at a setting of 5 until the temperature reached 62° C. The mixer was then shut off and the mixture allowed to cool to near room temperature. Shearing was then continued until all of the oil soluble resin was incorporated (visual observation). The sulfonated asphalt was then blended into the mixture.
The sample was then split. One sample was placed into the freezer at-20° F. (-29° C.) until the temperature stabilized in order to test for the pour point. No syneresis or settling was observed and the sample remained pourable. The other sample was placed In the oven 120° F. (49° C.) and static aged for twelve months. No syneresis or settling was reported.
This demonstrated that a stable liquid suspension of a sulfonated asphalt was obtained.
EXAMPLE 2
This composition contains the following components:
______________________________________light isoparrafin oil (1) 560 goil soluble resin (2) 20 gsulfomethylated tannin (3) 387 gTotal 967 g______________________________________ (1) A C.sub.13 -C.sub.14 isoparaffin mixture available under the brand "SOLTROL 170" (0.778 g/ml), from Phillips Petroleum Company. (2) A hydrogenated styreneisoprene copolymer available under the brand "SHELL VIS 40", from Shell Chemical Company. (3) Available under the brand "DESCO", from Phillips Petroleum Company.
The oil soluble resin was sheared into the light isoparrafin oil with a Ross mixer at a setting of 5 until the temperature reached 62° C. The mixer was then shut off and the mixture allowed to cool to near room temperature. Shearing was then continued until all of the oil soluble resin was incorporated (visual observation). The sulfomethylated tannin was then blended into the mixture.
The sample was then split. One sample was placed into the freezer at-20° F. (-29° C.) until the temperature stabilized in order to test for the pour point. No syneresis or settling was observed and the sample remained pourable. The other sample was placed in the oven at 120° F. (49° C.) and static aged for twelve months. No syneresis or settling was reported.
This demonstrated that a stable liquid suspension of a sulfomethylated tannin was obtained.
EXAMPLE 3
This composition contains the following components:
______________________________________light isoparrafin oil (1) 560 goil soluble resin (2) 20 gpowdered tin metal (3) 387 gTotal 967 g______________________________________ (1) A C.sub.13 -C.sub.14 isoparaffin mixture available under the brand "SOLTROL 170" (0.778 g/ml), from Phillips Petroleum Company. (2) A hydrogenated styreneisoprene copolymer available under the brand "SHELL VIS 40", from Shell Chemical Company. (3) 200 mesh.
The oil soluble resin was sheared into the light isoparrafin oil with a Ross mixer at a setting of 5 nntil the temperature reached 62° C. The mixer was then shut off and the mixture allowed to cool to near room temperature. Shearing was then continued until all of the oil soluble resin was incorporated (visual observation). The powdered tin metal was then blended into the mixture.
The sample was then split. One sample was placed into the freezer at-20° F. (-29° C.) until the temperature stabilized in order to test for the pour point. No syneresis or settling was observed and the sample remained pourable. The other sample was placed in the oven at 120° F. (49° C.) and static aged for two weeks. 3/4 inch of syneresis was noted at that time. The sample remained in the oven for another 3 1/2 months without showing further signs of syneresis. No hard settling was observed.
This demonstrated that a stable liquid suspension of a powdered tin metal was obtained.
EXAMPLE 4
This composition contains the following components:
______________________________________light isoparrafin oil (1) 560 goil soluble resin (2) 20 glime powder (3) 387 gTotal 967 g______________________________________ (1) A C.sub.13 -C.sub.14 isoparaffin mixture available under the brand "SOLTROL 170" (0.778 g/ml), from Phillips Petroleum Company. (2) A hydrogenated styreneisoprene copolymer available under the brand "SHELL VIS 40", from Shell Chemical Company. (3) "BREAKER 3700" lime powder from Nowsco Well Service, Ltd Calgary, Canada.
The oil soluble resin was sheared into the light isoparrafin oil with a Ross mixer at a setting of 5 until the temperature reached 62° C. The mixer was then shut off and the mixture allowed to cool to near room temperature. Shearing was then continued until all of the oil soluble resin was incorporated (visual observation). The lime powder was then blended into the mixture.
The sample was then split. One sample was placed into the freezer at-20° F. (-29° C.) until the temperature stabilized in order to test for the pour point. No syneresis or settling was observed and the sample remained pourable. The other sample was placed in the oven at 120° F. (49° C.) and static aged for three months. No syneresis or settling was reported.
This demonstrated that a stable liquid suspension of a lime powder was obtained.
While this invention has heed described in detail for the purpose of illustration, it is not to be construed as limited thereby but is intended to cover all changes and modifications within the spirit and scope thereof. | A new stable liquid suspension of a non soluble particulate material, and a method of preparation of same are provided. Such compositions comprise at least one oil, one oil soluble resin and a non oil soluble particulate material mixed together In the appropriate quantities and conditions. | 2 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a method for separating and purifying lactoferrin, which is a pharmacologically important milk protein having various physiological activities, from milk containing lactoferrin.
(2) Description of the Prior Art
Lactoferrin is an iron-binding glycoprotein present in an exocrine liquid such as milk and has a variety of physiological activities such as bateriostasis against pathogenic bacteria, adjusting function of leukocyte differentiation, build-up function of germicidal power, multiplicative function of lymphocyte and adjusting function of iron absorption. For that reason, it can be said that lactoferrin is a milk protein which is important not only from a nutritional viewpoint but also a pharmacological viewpoint.
As a result, many attempts have heretofore been made to develop methods for separating and purifying lactoferrin from milk. However, since lactoferrin is a protein having a very reactive molecular structure and interacting with other milk proteins, it has been difficult to separate and purify lactoferrin in a high purity and in a high yield by a simple and easy operation.
In other words, in order to separate high-purity lactoferrin, an intricate process and a long period of time is necessary. In addition, the recovery efficiency of lactoferrin is disadvantageously low.
Recently, a separating and purifying method for lactoferrin has been reported in which a raw liquid is passed through an affinity column where heparin having physiological affinity to lactoferrin is fixed on a carrier for chromatography such as Cephalose CL-6B (made by Pharmacia Labs., Inc.) with the aid of CNBr or the like, whereby lactoferrin is separated and purified therefrom (Blackberg, L. et al, FEBS LETT., 109, p. 180, 1980).
However, heparin is extracted and purified from the livers or intestines of pigs, cattle or the like, and differences in the source of extraction lead to differences in heparin properties. For this reason, it is hard to obtain a great deal of heparin having uniform properties. Further, heparin is expensive. As a result, the method of separating and purifying lactoferrin from milk by the use of the affinity carrier for chromatography having heparin bound and fixed thereto can be practiced only on an experimental scale. In other words, the above suggested known method is impracticable on an industrial scale. Further, the above method has the problem that heparin fixed on the carrier might be peeled therefrom and inconveniently mixed with separated lactoferrin on occasion.
SUMMARY OF THE INVENTION
A first object of the present invention is to provide a method for separating and purifying lactoferrin from milk on an industrial scale by a simple and easy operation. A second object of the present invention is to provide a method for separating and purifying lactoferrin from milk extremely effectively in a high yield and a high purity.
The present invention is characterized by bringing raw milk containing lactoferrin into contact with a sulfuric ester of a crosslinked polysaccharide so that lactoferrin may be adsorbed by the sulfuric ester, then eluting and recovering the thus adsorbed lactoferrin therefrom.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A sulfuric ester of a crosslinked polysaccharide used in the present invention has physiological affinity to lactoferrin in common with heparin and is superior in physical stability to heparin. This sulfuric ester can be prepared in quantity by esterifying, with anhydrous sulfuric acid or chlorosulfonic acid, a polysaccharide such as agarose, cellulose or chitin which has been crosslinked with a crosslinking agent (e.g., epichlorohydrin). The above crosslinked polysaccharide is commercially available.
However, since agarose is soft, it is liable to deforming. Thus in considering manufacturing lactoferrin on an industrial scale, a carrier such as cellulose or chitin is preferably used.
Since the sulfuric ester of such crosslinked polysaccharides is insoluble in an aqueous solvent and is excellent in physical stability, an affinity column charged with this sulfuric ester can sufficiently withstand the passage of a raw liquid on an industrial scale.
Examples of the sulfuric esters of the cross-linked polysaccharides include sulfated Cellulofine prepared by esterifying crosslinked cellulose (having an amino group) with sulfuric acid, and sulfated Chitopearl prepared by esterifying crosslinked chitosan (which is crosslinked via an amino group) with sulfuric acid.
The separation and purification of lactoferrin from milk by the use of the sulfuric ester of a crosslinked polysaccharide may be suitably carried out by passing raw milk through a column charged with a sulfuric ester carrier, or by mixing raw milk with the sulfuric ester and then stirring the resulting mixture.
In the present invention, the contact of the sulfuric ester with raw milk containing lactoferrin is conducted at a temperature of 50° C. or less, preferably at room temperature. First, raw milk is passed through the column, and the fraction which has not been adsorbed by the column is then eluted. Afterward, the column is washed with a 0.3M aqueous sodium chloride solution or a 0.01-0.02M buffer solution of, for example, sodium phosphate, tris-HCl, ammonia-HCl or Veronal (trade name), which contains a 0.3M aqueous sodium chloride solution and which has a pH of 5.0 to 9.0. Next, a 0.4M-1.5M aqueous sodium chloride solution, preferably a 1.0M aqueous sodium chloride solution or the above-mentioned buffer solution containing a 1.0M aqueous sodium chloride solution, is passed through the column, so that lactoferrin adsorbed on the column is eluted, whereby lactoferrin can be separated from the milk.
Alternatively, in the present invention, lactoferrin can be separated as follows: First, raw milk is mixed with the sulfuric ester, and this ester is then recovered by means of decantation or centrifugation. The thus recovered sulfuric ester on which lactoferrin is adsorbed is washed with a 0.3M aqueous sodium chloride solution or a buffer solution containing a 0.3M aqueous sodium chloride solution and having a pH of 5.0 to 9.0, and the ester is then again recovered by means of decantation or centrifugation. A 0.4-1.5M aqueous sodium chloride solution or the above buffer solution containing a 0.4-1.5M aqueous sodium chloride solution is added to the thus recovered ester, and washing is carried out. Afterward, the mixture is allowed to stand. By means of decantation or centrifugation, a supernatant liquid containing lactoferrin is collected, whereby lactoferrin is separated from the milk.
The thus separated lactoferrin is desalted by the use of an electrodialysis (ED) apparatus or a reverse osmosis (RO) apparatus, then freeze-dried, and afterward preserved at 40° C. or less, preferably at 4° C. In this regard, reproduction of the ester from which lactoferrin has been separated can be achieved by washing the ester with a 2M aqueous sodium chloride solution and then passing a 0.15M aqueous sodium chloride solution through it.
The thus-obtained lactoferrin has a purity of 95% or more, as confirmed by a chart of SDS electrophoresis.
Examples of the raw milks used in the present invention include colostrum, transitional milk, ordinary milk and final milk of mammals such as humans, cattle and sheep as well as low temperature-sterilized milk and whey.
When lactoferrin is separated and refined from these raw milks in accordance with the present invention, there are no problems such as the necessity of a long treatment time and a low recovery of lactoferrin which can be attributed to the complicated operation and processes of conventional methods.
In other words, according to the present invention, lactoferrin can be recovered in a high purity and in a high yield. In particular, the present invention is intended to adsorb lactoferrin present in milk by a crosslinked polysaccharide sulfuric ester alone, which is excellent in physical stability, and therefore there are no problems as in the conventional method in which an affinity carrier for chromatography containing the fixed heparin is used, one of the above problems being that heparin is peeled from the carrier. In the present invention, since adsorbed lactoferrin can be easily eluted by using an aqueous sodium chloride solution alone, the separation of lactoferrin can be performed very efficiently.
In addition, since the crosslinked polysaccharide sulfuric ester used in the present invention can be prepared by esterifying, with sulfuric acid, a crosslinked polysaccharide, a raw material of which is cellulose or chitin abundant in nature, this ester can be manufactured in quantity and is conveniently available at a low cost.
From results measured in accordance with the process suggested by Woodworth et al. (Protides Biol. Fluids Proc. Colloq., 14, p. 37, 1969), it has been shown that the lactoferrin separated by the present invention has an iron-binding capacity of 1.3 to 2.1 milligrams of Fe per gram of lactoferrin, which proves that the lactoferrin possesses its original iron-binding capacity intact. Therefore, the lactoferrin obtained by the present invention can be utilized as a preventive medicine to protect infants from pathogenic bacteria which require iron and as a therapeutic medicine against various symptoms based on the pathogenic bacteria.
Moreover, in the present invention, the lactoferrin solution separated and purified by the process described above may be mixed with ferric chloride directly and then stirred, and the mixture may be then passed through a ED apparatus or an RO apparatus in order to separate iron-saturated lactoferrin therefrom with ease. Accordingly, the present invention is particularly useful to facilitate the absorption of iron in the intestine. In this regard, it has been already reported that iron-saturated lactoferrin has the effect of improving the absorption of iron in the intestine (Cox, T. M. et al., Biochim. Biophys. Acta, 588, p. 120, 1979).
The present invention will now be described in detail by way of examples.
EXAMPLE 1
Commercially available Cellulofine (trade name), which is a crosslinked cellulose, was esterified with anhydrous sulfuric acid in a conventional manner to form sulfated Cellulofine, and a column having a diameter of 2 cm and a length of 20 cm was charged with 50 ml of the thus sulfated Cellulofine. Through this column, 50 ml of defatted human colostrum was then passed at a rate of 10 ml/minute. Afterward, the column was washed with 300 ml of a 0.3M aqueous sodium chloride solution, and lactoferrin adsorbed on the column was then eluted with 100 ml of a 1.0M aqueous sodium chloride solution. The thus-obtained lactoferrin solution was subjected to dialysis in exchange for a sufficient amount of deionized water, followed by freeze-drying, thereby obtaining 110 mg of human lactoferrin. The purity of the recovered human lactoferrin was measured at 97% by a chart of SDS polyacrylamide gel electrophoresis, and the amount of combined iron was measured at 0.2 mg of Fe per gram of protein by means of a serum iron measuring kit (made by Wako Junyaku Co., Ltd.). Further, it was confirmed by the Woodworth process that the total iron bonding capacity was 100%.
EXAMPLE 2
Commercially available Chitopearl (trade name), which is a crosslinked chitosan was esterified with anhydrous sulfuric acid in a conventional manner to form sulfuric acid-esterified chitopearl, and a column having a diameter of 8 cm and a length of 20 cm was charged with 1 liter of the thus sulfated Chitopearl. Through this column, 50 liters of defatted bovine milk was then passed at a rate of 20 liters/hour. Afterward, the column was washed with 5 liters of a 0.3M aqueous sodium chloride solution, and lactoferrin adsorbed on the column was then eluted with 3 liters of a 1.0M aqueous sodium chloride solution. The thus-obtained lactoferrin solution was desalted by a small-sized type ED apparatus (TS-210; made by Tokuyama Soda Co., Ltd.), and was concentrated tenfold by a UF apparatus (DH-2; made by Amicon Co., Ltd.), followed by freeze-drying.
The amount of the thus recovered lactoferrin was 6 g. The purity of the lactoferrin was measured at 95%, and the amount of combined iron was 0.2 mg of Fe per gram of protein. Further, it was confirmed that the total iron bonding capacity was 98%.
EXAMPLE 3
In this example, lactoferrin was separated and purified by a batch system by mixing raw milk with a sulfuric ester.
Through the sulfated Chitopearl used in Example 2, first a 2.0M aqueous sodium chloride solution and then a 0.15M aqueous sodium chloride solution were passed to reproduce the sulfated Chitopearl.
One liter of the thus reproduced sulfated Chitopearl was mixed with 100 liters of cheese whey and then stirred for 1 hour, and the resulting mixture was washed with 5 liters of a 0.3M aqueous sodium 13 chloride solution. Afterward, lactoferrin adsorbed on the sulfated Chitopearl mixture was eluted with 3 liters of a 1.0M aqueous sodium chloride solution. To the thus obtained lactoferrin solution, 50 mg of ferric chloride was added, followed by further stirring. After a reverse osmosis apparatus (MRG 10 moled; made by Mitsubishi Rayon Co., Ltd.) was used to perform desalting and concentration (tenfold), freeze-drying was carried out to obtain 4.8 g of iron-saturated bovine lactoferrin. The purity of the recovered bovine lactoferrin was 95%, and the amount of combined iron was 1.3 mg of Fe per gram of protein. Further, it was confirmed that the saturation degree of iron was 93% or more. | A method for separating and purifying lactoferrin from milk is disclosed, which method comprises the steps of bringing raw milk containing lactoferrin into contact with a sulfuric ester of a crosslinked polysaccharide so that lactoferrin may be adsorbed by the sulfuric ester, and then eluting the adsorbed lactoferrin. The elution of the adsorbed lactoferrin is preferably conducted by the use of a buffer solution containing a 0.4-1.5 M aqueous sodium chloride solution. | 8 |
This application is a continuation of a provisional application No. 60/100,602 filed Sep. 16, 1998.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to a method for adding two or more power amplifiers in parallel, and balancing the current between the parallel joined amplifiers.
2. Prior Art
Paralleling of amplifiers (fast four quadrant DC to AC power converters) has been done for some time, but presently, the amplifiers are changing from linear to switch-mode technology. Also the environment in which they operate is continuing to demand larger amounts of power. When parallel amplifiers do not share current, costly inefficiencies arise.
At first paralleling of amplifiers was done by using simple passive ballasting. Linear amplifiers had wide bandwidth and fairly small phase errors which led to substantial conformity of gain and phase characteristics. High frequency circulating currents were reduced by using a highly coupled center tapped inductor whose center tap joined to the loads and whose ends attached to an amplifier output. If the amplifiers are delivering equal currents, such as inductor will store no net energy and thus no signal voltage will be lost to inductance. It is important not to loose signal voltage as the cost of generating large amounts of power are also large.
When the demands on the ballast resistors grew to more than 250 Watts of dissipation, negative current feedback was used to synthesize an effective amplifier output resistance (lossless). This constituted a second and improved generation of paralleling design.
With the advent of high efficiency switch-mode amplifiers additional issues have arisen. Output currents are typically larger and the gain and phase characteristics are now much looser in tolerance, potentially making current sharing more difficult.
One of the preferred uses of the subject paralleled amplifiers is in the medical industry, for use with magnetic resonance imaging (MRI), where the load on the system is the gradient coil of the MRI device. This environment is relatively hostile for gradient signal processing, because the MRI device has large amounts of peak RF power (<=20 KW) supplied to coils which are immediately inside the gradient coils. With such intimate coupling, it is necessary to place low-pass filters in the feed lines to the gradient coils to contain the RF currents. These filters tend to aggravate an already bad situation for establishing wide bandwidth negative current feedback. Large phase response lags within the amplifiers and distributed capacitances in the gradient coils already have limited the amounts of feedback that can be used to control the system. Any controls added to effect current sharing dare not corrupt the output signal as there is insufficient feedback to correct any significant injected non-linear errors. Therefore some of the methods practiced by the DC to DC converter industry for current sharing are not applicable here.
What is desired is a lossless means of sensing circulating (unbalance) currents caused by mismatched parallel power converters and introducing output corrections in such a manner as to not influence the net output available to the load. This implies that the entire method is lossless and also has no net output inductance added to the load circuit.
SUMMARY OF THE INVENTION
The objects of the invention have been accomplished by providing a system of two or more (n) parallel joined power converters which use current sensors to directly measure the circulating currents and by use of negative feedback regulates the circulating current to zero. Preferably this system uses passive magnetic devices to facilitate current sharing, which devices are each designed to store no magnetic energy when under balanced excitation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an N of 2 paralleled balanced output amplifiers, showing specific circuitry for the novel features and characteristics; and
FIG. 2 is a schematic view of a further embodiment of the invention, including an N of 3 paralleling method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With respect first to FIG. 1, and N of 2 paralleled balanced amplifier circuit is shown generally as reference numeral 2 which is generally used for the purpose of providing balanced output to a load 4 , such as a gradient coil 4 . With reference still to FIG. 1, the circuit 2 would further include an assembly of state of the art circuitry shown generally at 6 , which would encompass input amplifiers and filters, current control feedback and output monitors, and the like. The circuit 2 would also include first and second power modules 8 and 10 which comprise individual amplifiers 8 a, 8 b and 10 a and 10 b respectively. The circuit 2 further comprises current sensing transducers 12 and 14 and passive devices 16 and 20 . A main current transducer 22 is provided medially positioned between the load and the passive device 20 providing a feedback loop to the state of the art circuitry 6 .
With respect still to FIG. 1, an input signal is provided to the power modules 8 and 10 via buses 24 and 26 , while the input to individual amplifiers 8 a and 8 b is via buses 28 a and 28 b respectively; and to amplifiers 10 a and 10 b via buses 30 a and 30 b respectively. Meanwhile, the outputs of amplifiers 8 a and 8 b are interconnected to current sensing transducers 12 and 14 via buses 32 a and 32 b respectively, while the outputs of amplifiers 10 a and 10 b are directed through current sensing transducers 12 and 14 via buses 34 a and 34 b. The current sensing transducer 12 is interconnected to the passive device 16 , while the passive device 16 is interconnected to the load 4 by way of a bus 38 . Likewise the current sensing transducer 14 is joined to the passive device 20 , which in turn is interconnected to the main current transducer 22 by way of bus 42 , and then directly to the load by way of bus 44 .
With reference still to FIG. 1, pre-amps 46 and 48 are interconnected to the transducers 12 , 14 and then to further amp circuits 50 and 52 , by way of buses 54 and 56 . The output at 55 of amp 50 is then diverted to summing amp circuits 60 , 62 via buses 55 a, 55 b, respectively. Meanwhile, the output at 57 from amp 52 is diverted to summing amp circuits 64 , 66 via buses 57 a, 57 b. The loop is closed when the output is again joined to the main power amps 8 a, 10 a by buses 28 a, 30 a; and when the output of the amps 64 , 66 is again joined to the power amps 8 b, 10 b by buses 28 b, 30 b.
With reference now to FIG. 1, the operation of the invention will be described relative to its diagrammatic sketch, and in relation to the preferred embodiment of the invention. It should be understood that, one of the preferred modes of operation for the invention is for use in the amplification within magnetic resonance imaging (MRI) devices, but the invention is not so limited to such a use. It should also be understood that while this specific application, that is for use with an MRI, requires a full bridge configuration, that the invention is its broadest sense is not so limited, but rather could be used in some applications in a half bridge configuration, for example, for use in driving a poly-phase motor, etc. FIG. 1 shows by way of the dashed line, the symmetry line for the half bridge configuration. It should also be appreciated that there are two balancing signals involved because there are two half bridge pairs coming together, that is, two half bridge pairs that are going to be combined, that is amplifiers 8 a and 10 a.
When these two signals are not balanced, there will not be perfect gain coming to the load and a circulating current will be formed which flows around the loop through the passive device 16 . For this reason, sensor 12 is precisely placed within the circuit, is actually sensing the difference current in buses 32 a and 34 a. It is therefore represented with a positive mark and a negative mark because of the passing through in opposite directions; so that twice the different is actually sensed by its core. The core then reports that as a dc coupled signal which is then amplified by the error amplifier 46 , 50 which integrates, and which error signal is sent back to become part of the input signal to the amplifier. It should be appreciated that the identical course of action is true on the opposite half-bridge, that is through transducer 14 , sensing the difference current through buses 32 b and 34 b.
It should be appreciated from FIG. 1, that two current sharing methods are introduced, where the first has been described in relation to the current sensing balance transducers 12 , 14 ; and which are for use at low frequencies. At high frequencies, the coupled magnetic device 16 , 20 are used to provide a module to module inductance, without adding to the output inductance of the pair. With reference now to FIG. 2, the sizing of the current sensors such as 12 , 14 ; and the passive devices 16 , 20 will now be described in greater detail.
Each one of these amplifiers 160 , 162 , 163 , 164 , 166 and 167 is shown now with three input ports, where each has a main input port, each shown as the center port, 160 a, 162 a, and so on. On these ports, that is these main ports, the coefficients of gain are approximately equal, and the value of the coefficient is immaterial. Each amplifier, 160 - 167 , has two remaining ports, a b-port and a c-port, which receive balancing signals, and are symmetric as it relates to their gain coefficients. The gain coefficients of the two remaining ports are characterized by two gain coefficients, a and b, with the gain coefficients being distributed according to the following table:
Gain Coefficients
Coefficient a
Coefficient b
Amplifier Ports
160b, 162b, 162c, 163c,
160c, 163b, 164c, and
164b, 166b, 166c and 167c
167b
The relationship between Gain Coefficients a and b, is the following:
a=−b/2 when b=k, and where k is an arbitrary constant.
The relationship between a and b is important for the balancing, that is upon the error correcting signals coming back into the summing amplifiers 160 - 167 . With reference still to FIG. 2, the current sensing transducers 112 a and 112 b, 114 a, and 114 b, and their internal wiring will now be described in detail. It should first be noted that the current transformers 112 a, 112 b, 114 a, 114 b form a low pass structure, whereas the passive members 116 , 120 form a high pas structure.
Now with respect to the low pass structure, the number of current sensing transducers required is related to the number of amplifiers (N) in the system being paralleled, such that the number of sensors required equals (N−1). With respect now to the wiring, where “t” is the number of turns in the sensor, the sensors 112 a and 114 a will have 2 t windings in the primary, and 1 t windings in the remaining windings, with the latter windings poled the same way. With respect to sensors 112 b and 114 b, the windings are opposite to those of sensors 112 a and 114 a, as shown in FIG. 2 . The resulting signals represent a pair of difference equations; differencing the outputs of amplifiers 108 , 110 and 111 .
Now with respect to the passive system, the system is comprised of inductors 116 and 120 , which could be a small toroidal core which are shared by all the windings. In the case of the passive system, the geometry is not important, but just as in the active system, that is sensors 112 and 114 , the numbers of windings and polings is. As shown in FIG. 2, the number of windings is shown for each passive device as either M or 2M, where M is the number of turns taken on some common shared magnetic circuit. As mentioned above, the geometry is not the issue, but how the windings are poled and what the relative number of flux lines that are generated that is important. As the currents are matched flowing through these the three separate sections of the passive device, there will be no field in the core because the current will be in balance.
In summary, the low frequency loop comprised of the current sensors 112 , 114 monitors imbalance to make sure low frequencies, don't persist on the cores. But the low pass loop has limited bandwidth, and is not capable of tracking rapid errors allowing for rapid errors or short term errors that exist between the voltages found at the outputs of these amplifiers. The passive device can as it is a high pass structure. Further advantageously, there is not net inductance created, nor is there any excess volume of core material having any net flux stored in the core. This also keeps its core small and it keeps its cost low.
As mentioned above, the same winding rules apply to (N−1) magnetic cores as are applied to the current sensing transducers which produce the desired result. In this situation, the turns multiplier for all the current carrying windings may be an integer greater than 1. Each of the cores will have one winding driven with reverse poling that has (n−1) times the turns as do any of the others. Each core's windings are seriesed with those of the next core's until each of the (n−1) amplifiers has one and only one core that represents it with a counter-poled winding. A master amplifier will have no such core and will have passed through identical minimal windings in all (N−1) cores. Care should be used to keep the net resistance similar in all of the wiring including the so-called passive master. Note that the amplifier which is declared to be the master in the passive system is not required to be the pseudo-master in the active balance system.
Advantageously, the passive balance impedance can more practically be created with simply inductors where (N) is large. The impact on the net inductance output source impedance is diluted by (N) regardless. For a small (N) such as 2 or 3, the added output inductance is more of a concern. In this case, lower mu core materials will be used to simple inductor design to minimize the saturation effects. The case of larger (N) also dilutes the need for this type of active balancing system as the noise of (N)'s simple active ballast feedback system is reduced by the square root of (N). Noise is thereby seen to be less improved by large (N) than is the output impedance for the simple inductor case. | A generalized method for balancing paralleled power converters is disclosed wherein (N) power converters, generally voltage amplifiers, are parallel and have current sensors positioned so as to form a differencing equation for the circulating current, and use that difference current as feedback to the paralleled power converters to force the circulating current to zero. The current sensors are current transforming transducers, where (N−1) transducers are included and where the feedback from the (N−1) transducers is distributed to summing amplifiers, which according to their gain distribution, balances the power converters. The system also includes passive magnetic devices to facilitate current sharing, where the devices are generally inductors which are designed to store no magnetic energy when under balanced excitation. | 7 |
FIELD OF INVENTION
[0001] The present invention relates in general to the packaging of novelty items to be included with products. The novelty items include promotional materials such as gaming cards, t-shirts, hats, frisbees, etc. and the packing comprises a clear PVC tray that can be adhered to a box.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to display packaging. It has become increasingly popular for manufacturers to use promotional items to enhance sales of their product. Manufacturers of product with direct competition commonly apply a “Value Add” or “Incentive” with purchase to induce the customer to buy their product versus the competitors. For example, logo'd t-shirts and baseball caps are often used to promote products such as beer, soft drinks and other products, even tractors! These items are often distributed by salespeople at their discretion and it requires them to ensure that the promotional items are easily accessible in spaces where storage may be a minimum. This also requires having appropriate stock of the promotional item for the amount of stock of the product. Furthermore, these “Value Add” products typically do not have a uniform shape and thus do not allow for stackability of the cases yet cases of product are typically stacked high for shipping and retail purposes. An example would be, if the manufacturer applies a flash light as an incentive to the top of a case of beer, the manufacturer would not be able to stack another case on the top because of it's smaller rounded size. For this reason, “value adds” have typically been dropped inside the case. However, then the consumer cannot see the item and may not be enticed to buy the product.
[0003] Thus, there remained a need for better ways to ensure that the promotional item is properly distributed along with the product. The present invention addresses this need by providing a novel type of packaging assembly that ensures each piece of merchandise has a promotional item associated with it in a manner that does not interfere with normal storage or stacking of product. In addition, with the packaging system of the present invention, the consumer is visually stimulated by the value-added item which is displayed on the topside or side of the case which still allows the manufacturer to stack items on the top of the cases.
SUMMARY OF THE INVENTION
[0004] The present invention provides a novel way of displaying promotional items along with a product by adding on a display package. The promotional item is displayed on the product packaging in a clear PVC display panel that includes well(s) to retain the position of the item(s). The display panel is attached to the product packing along at least two sides of the panel.
[0005] In one aspect of the invention, the display panel for attaching a promotional item to a box comprises a clear support surface and at least two side attachment means. The support surface comprises at least one well for supporting and retaining a promotional item. Within the display panel a well may be upwardly opening or downwardly opening. The well may be a snap-fit type of well. Alternatively, the promotional item may be retained within the well by the surface of the box or by a sheet covering. The sheet covering could be a clear panel over an upwardly open well or it could be a cardboard backing under a downwardly open well. In a preferred embodiment, the cardboard backing would be printed with promotional matter. The combination of the support surface and the sheet covering may provide a reusable case for the promotional items.
[0006] In one preferred embodiment, the display panel includes wells adapted to receive the paraphernalia associated with poker. It includes a well adapted to retain playing cards and several wells adapted to retain poker chips. It may also include a well to retain a “Dealer” button.
[0007] The display panel may include wells of different sizes and shapes adapted to retain all types of promotional items. For example, without limiting the scope of the invention the wells may be adapted to retain a T-shirt, calendar, Frisbee, sunglasses, darts, cap, toque, scarf, CD, DVD, keychain, bottle opener and the like as well as combinations of different items. The display panel is preferably attached to a box containing a product using side attachment means that typically comprise a strip of PVC disposed along one side of the display panel. The strip of PVC includes an adhesive strip. The attachment means is wrapped around the side of the box and when it adheres the display panel is held in position on top of the box.
[0008] While the following description with regard to the figures focuses on adhering the display panel to the top of a box, it is clearly apparent to one skilled in the art that the display panel could also be adhered to the side of a box using the same mechanisms. It is also clearly apparent that while the description has focused on a generally rectangular panel for attachment to a rectangular box, the display panel can be provided in different shapes. Furthermore the display panel could, under certain circumstance be applied directly to a product that is not boxed. For example, the display panel could be directly attached to a product having a flat surface by adhering the attachment means to the surface. The display panel can even be configured to attach to surfaces that are not flat (i.e. rounded).
[0009] In another aspect of the invention, a novel method of attaching a promotional item to a product is provided. The method comprises: obtaining a display panel as described above, inserting the promotional item into a well adapted to retain it, placing the display panel on top of a box, and adhering the attachment means to at least two sides of the box.
[0010] This summary of the invention does not necessarily describe all features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein:
[0012] FIG. 1 is a perspective view of a packaging tray according to one embodiment of the invention mounted on a box;
[0013] FIG. 2 is a side elevation of the embodiment shown in FIG. 1 ;
[0014] FIG. 3 is a perspective view of another embodiment of a display tray according to the present invention;
[0015] FIG. 4 is a side view of the embodiment illustrated in FIG. 3 ;
[0016] FIG. 5 is a perspective view of yet another embodiment of the invention;
[0017] FIG. 6 is a side view of the embodiment shown in FIG. 5 ;
[0018] FIG. 7 is a perspective view of yet another embodiment of the display tray of the invention;
[0019] FIG. 8 is a side view of that embodiment; and
[0020] FIG. 9 is a side elevation of one embodiment before it is applied to a box;
DETAILED DESCRIPTION
[0021] The present invention provides a novel packaging system for the containment and display of promotional items. The packaging system of the present invention comprises a clear plastic display panel which includes wrap around sides that can be adhered to the sides of a box. The display panel comprises wells into which the promotional items are fitted. The wells may be formed on the outer or user-facing surface of the display panel or they may be formed on the inner or box-facing side of the display panel. In other words, the wells can be upwardly or downwardly open.
[0022] The display tray of the present invention provides a novel way to display promotional items. Manufacturers of consumer products such as beer, shoes, toys, etc. often provide promotional items along with their product. For example, beer producers may also include a beer bottle opener with each case of beer that is sold. Likewise, manufacturers of toys often provide as a promotional item, playing cards depicting the characters of the toys. The display panel of the present invention provides a novel way of combining promotional items with a product. The display case includes wrap around sides that fit over the side edges of a box. These side edges may comprise hard surfaces that fit snuggly over the edges of the box or they may include flexible strips that fold over the side of the box and that can be adhered to the side of the box. The display panel includes at least two side panels that interact with the box. In some embodiments, the display panel may include four overlapping side panels that interact with the box. The display panels can be configured to fit various sizes and shapes of boxes. For example, it may be sized to fit over a beer case. Alternatively it could be sized to fit over a shoe box a picnic basket, or any other shaped box. The display panel comprises at least one well that is configured to receive and hold in position a promotional item. While the display has been shown in the accompanying drawings fitted over the top of a box, it is clearly apparent that in other situations the display panels can be adapted to fit over the side of a box and adhere along those sides. The well(s) of the display case can be sized to fit any variety of promotional item. The display panel of the present invention may optionally include a cardboard backing. The cardboard backing may be printed with advertising that can be seen through the clear top of the display case.
[0023] Referring now to the Figures, FIG. 1 illustrates one embodiment of a display tray according to the present invention. In this embodiment, the display tray 10 comprises a generally rectangular well 12 and five circular wells 14 disposed in a support surface 16 . The rectangular well 12 is configured to hold a deck of playing cards. The circular wells 14 are sized and shaped to hold poker chips. The display tray may optionally include another circular well 18 which is sized to receive a dealer button. In this embodiment the display tray 10 is sized to fit over the top of a beer case 20 . At least two sides of the display tray include means for attaching the tray to the box. FIG. 2 is a side view of the display tray mounted on a box whereby adhesive sides are shown attached adhered to the sides of the box. In the illustrated embodiment, the items are snap fitted into the wells and held in place by internal lips. Finger holes are provided to help the consumer remove the promotional items from the tray.
[0024] FIG. 3 illustrates another embodiment of the display tray 10 of the present invention. In this embodiment, the tray comprises one large well 40 that is adapted to fit a calendar 42 . The calendar can be viewed through the clear plastic top of the display case. FIG. 4 is a side view of the embodiment shown in FIG. 3 . The large central well can be seen here accommodating a calendar.
[0025] FIG. 5 illustrates yet another embodiment of the display tray according to the present invention. In this embodiment, the display tray 10 is adapted to hold a T-shirt 44 . The different display trays may be applicable to different advertising opportunities. For example, a maker of athletic footwear may wish to include a t-shirt on top of a box of their shoes. In this embodiment, the display case comprises a well 46 that has been adapted in size and shape to receive a t-shirt. FIG. 6 is a side view of this embodiment showing the t-shirt folded within the well of the display tray. Once again, you can see that the display tray is adhered to the top of the box.
[0026] In FIG. 7 , another embodiment of the invention is illustrated. This embodiment demonstrates that the display device may include a variety of different shaped wells adapted to receive specifically shaped promotional items. In the illustrated embodiment, the tray has been adapted to include a well 50 for a frisbee and a pair of sunglasses. A side view of this embodiment is shown in FIG. 8 .
[0027] FIG. 9 illustrates the display panel before it is attached to a box. Along at least two sides 24 , 26 of the support surface 16 attachment means are provided. In this embodiment, the attachment means comprise strips 28 of clear PVC that have an adhesive coating 30 on the underside. In use these strips are wrapped around the side of the box and adhered as shown in FIG. 2 .
[0028] The present invention has been described with regard to one or more embodiments. However, it will be apparent to persons skilled in the art that a number of variations and modifications can be made Without departing from the scope of the invention as defined in the claims. | A display panel for associating a promotional item with a product is provided. The display panel includes wells to retain the promotional item in a fixed location. The display panel also includes side attachment means for adhering the panel to the associated product. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to a capo for guitars and particularly to a capo that has a snap trigger and adjustable clamp opening to facilitate tune setting.
BACKGROUND OF THE INVENTION
[0002] Capo is mounted onto frets of a guitar to adjust high and low pitches. Refer to FIGS. 1 and 2 for two types of conventional capos. In FIG. 1 , a string press bar 1 a has an extension arm 2 a connecting to a positioning clamp 3 through a spring 5 . When a handgrip 4 receives a force, the spring 5 can be moved. When in use, a performer needs a greater force to clip the fret, thus is difficult to move to the desired fret or remove therefrom, especially to female users.
[0003] FIG. 2 illustrates another type of capo designed to overcome the drawback of the aforesaid capo. It has an adjustment screw 6 running through a holding plank 7 and connecting to a positioning clamp 8 to incorporate with a string press bar 1 b equipped with an extension arm 2 b to provide desired function. It provides an improvement by turning the screw. However, screw turning involves tedious movement and impairs performance. A capo mentioned above is needed to be set on a desired fret to adjust the high or low pitch.
[0004] All these show that the conventional techniques still leave a lot of room for improvement. How to make tuning of guitars faster and easier is an issue still pending to be resolved.
SUMMARY OF THE INVENTION
[0005] Therefore, the primary object of the present invention is to provide a capo that can be quickly and easily moved and clamped on the frets of a guitar.
[0006] To achieve the foregoing object, the capo according to the invention includes a string press element, a trigger and a lever clamp. The string press element has two ends, one is a string press end and the other end extended upwards to form an arm with an action end. The arm has a trigger slot at one side remote from the string press end with two side walls formed thereon. The action end has a first axle hole formed on the two side walls.
[0007] The trigger is held in the trigger slot, and has a second axle hole pivotally coupled in the trigger slot. The trigger is an elongate plank with an upper end and a lower end. The upper end is a sliding end. The lower end is an operating end. The lever clamp has a clamping end at one end and an adjustment end at another end. The adjustment end is located above the sliding end of the trigger and has a screw hole run through by an adjustment screw. Below the lever clamp has a first trenched axle. The first trenched axle and an elastic element are hinged on the first axle hole. The clamping end and the string press end form a clamping opening.
[0008] The capo thus formed provides many benefits, notably:
[0009] 1. The first axle hole, sliding end and second axle hole form triangular fulcrums. Incorporating with the lever clamp and a roller, the trigger, lever clamp and the string press element form the clamping opening. Such a design provides labor-saving and easier clamping adjustment regardless different sizes and heights of guitar frets. Through the trigger, performers can easily and quickly move the clipping location on the strings. It helps the performers to get a smoother performance.
[0010] 2. Aside from providing improved practicality, the invention also offers more aesthetic appeal. First, the trigger slot is provided to hold the trigger; second, the first trenched axle allows the lever clamp to be hinged on the first axle hole. Hence the whole profile is neat, elegant and simpler. It is more helpful and appealing to performers.
[0011] The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying embodiments and drawings. The embodiments serve merely for illustrative purpose and are not the limitation of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic view of a first conventional capo.
[0013] FIG. 2 is a schematic view of a second conventional capo.
[0014] FIG. 3 is a side view of the invention.
[0015] FIG. 4 is sectional side view of the invention.
[0016] FIG. 5 is an exploded view of the invention.
[0017] FIG. 6 is a sectional side view of the invention in a use condition.
[0018] FIG. 7 is a schematic view of another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Please refer to FIGS. 3 , 4 and 5 , the present invention provides a capo. It includes a string press element 10 , a trigger 20 and a lever clamp 30 . The string press element 10 has two ends, one is a string press end 11 and the other end extended upwards to form an arm 12 with an action end 121 . The arm 12 has a trigger slot 122 at one side remote from the string press end 11 with two side walls 123 . The action end 121 has a first axle hole 125 formed on the two side walls 123 .
[0020] The trigger 20 is held in the trigger slot 122 . The trigger slot 122 has a housing space 124 through the two side walls 123 . The trigger 20 is held in the housing space 124 . The trigger 20 is hinged in the trigger slot 122 through a second axle hole 21 . The trigger 20 is an elongate plank with an upper end and a lower end. The upper end is a sliding end 22 . The lower end is an operating end 23 . The sliding end 22 has a roller 24 hinged thereon to facilitate sliding. The operating end 23 is jutting below the string press end 11 to facilitate triggering.
[0021] The lever clamp 30 has a clamping end 31 and an adjustment end 32 . The adjustment end 32 is located above the sliding end 22 of the trigger 20 , and has a screw hole 33 run through by an adjustment screw 34 . The adjustment end 32 further is coupled with a pressing washer 37 run through by the adjustment screw 34 to form a firm fastening with the screw hole 33 . The lever clamp 30 has a first trenched axle 35 at a lower side. The first trenched axle 35 and an elastic element 36 are hinged on the first axle hole 125 . The clamping end 31 and the string press end 11 jointly form a clamping opening 40 . The string press end 11 and the clamping end 31 have respectively a rubber pad 50 located thereon facing each other.
[0022] The elastic element 36 is a returning spring with two holding ends 361 . The arm 12 has a first holding spot 126 at one side close to the string press end 11 and below the first axle hole 125 . The lever clamp 30 has a second holding spot 311 located below the clamping end 31 . The first and second holding spots 126 and 311 aim to hold the two holding ends 361 of the elastic element 36 . When the clamping end 31 is moved downwards to do clamping, the second holding spot 311 also stops two detent edges 351 formed on the first trenched axle 35 .
[0023] The invention further has a butting element 60 with a butting end 61 at one end and a hinge end 62 at the other end. The hinge end 62 is clamped and coupled with the first trenched axle 35 from both sides. The butting end 61 is interposed between the sliding end 22 and the adjustment end 32 . The hinge end 62 further has a second trenched axle 621 narrower than the first trenched axle 35 to be clipped therein. The second trenched axle 621 also is pivotally coupled with the elastic element 36 . The butting end 61 has a leaning surface 611 and a butting surface 612 . The butting surface 612 allows the sliding end 22 to slide thereon. The leaning surface 611 allows the adjustment screw 34 to rest thereon for adjustment.
[0024] Refer to FIG. 6 for the invention in use and FIG. 7 for another embodiment. When in use, the operating end 23 of the trigger 20 is moved away from the arm 12 , the roller 24 of the sliding end 22 slides on the butting surface 612 and enters the housing space 124 of the trigger slot 122 . Through the first trenched axle 35 and the elastic element 36 , the adjustment end 32 and the butting element 60 are moved downwards, and the clamping end 31 is moved upwards. As a result, the clamping opening 40 becomes larger so that the string press element 10 and the clamping end 31 can clamp the frets of a guitar. By adjusting the distance of adjustment screw 34 on the leaning surface 611 , it can be used on the frets of different guitars. The string press end 11 can be either a flat or a curved surface. FIG. 3 shows the string press end 11 formed with a flat surface for use on frets of classic music guitars, while FIG. 7 shows the string press end 11 formed with a curved surface for use on frets of folk music guitars.
[0025] As a conclusion, the invention provides the first axle hole 125 , sliding end 22 and second axle hole 21 that form triangular fulcrums. Incorporating with the lever clamp 30 and roller 24 , the clamping opening 40 can be adjusted easier and simpler to do clamping. Compared with the conventional techniques, it offers a lot of improvements, such as: first, with movements of the string press element 10 and the lever clamp 30 , and the trigger 20 , the clamping opening 40 is formed to provide clamping as desired. Users can easily and quickly move the operating end 23 single-handed with less effort. It greatly helps performers to provide smooth performance. Moreover, the roller 24 at the sliding end 22 can slide easily on the butting surface 612 and reduce wearing of the butting surface 612 . Second, through the butting element 60 and adjustment screw 34 , the clamping opening 40 can be easily adjusted through the lever clamp 30 . Third, when the clamping opening 40 clamps a fret of a guitar, the two detent edges 351 of the first trenched axle 35 are stopped by the first holding spot 126 to prevent too much compression on the elastic element 36 that might cause elastic fatigue or damage of the lever clamp 30 . Fourth, the pressing washer 37 allows the adjustment screw 34 to be fastened firmer that prevents loosening of the adjustment screw 34 caused by sound wave vibration during playing of the guitar. Noise generation also can be reduced.
[0026] In addition to improvement of practicality, the invention also provides a greater aesthetic appeal. The trigger 20 can be easily held in the trigger slot 122 . The first trenched axle 35 allows the lever clamp 30 to be hinged easily. The whole profile is neat and simpler, and provides an elegant match with performers to enhance appeal. | A capo has a string press element with an arm and a lever clamp that are coupled to form a clamping opening. The lever clamp has an adjustment end to adjust the size of the clamping opening. A trigger is provided to implement clamping operation. The clamping opening can clamp frets of a guitar. The capo can be quickly and easily deployed by a user single-handed through the trigger during playing the guitar. The capo is formed in a simple and neat profile, and provides a desirable match with performers or female performers to enhance appeal. | 6 |
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/194,065, filed Jul. 29, 2005, which claims priority to U.S. provisional application No. 60/592,412, filed Jul. 30, 2004, the contents of which are incorporated herein by reference.
BACKGROUND
[0002] 2′-Deoxynucleosides and their analogues are therapeutically important agents. For example, 2′-deoxy-2,2′-difluorocytidine hydrochloride can be used to treat viral infection and cancer (see, e.g., U.S. Pat. Nos. 4,526,988 and 4,808,614).
[0003] In general, 2′-deoxynucleosides each have more than one chiral center and can occur as multiple stereoisomers. Not all stereoisomers are therapeutically active. Several stereoselective synthetic routes for 2-deoxy-β-nucleosides have been developed. However, none of them are satisfactory. There is a need to develop a more effective route for stereoselectively synthesizing 2′-deoxynucleosides.
SUMMARY
[0004] This invention is based on an unexpected finding that (R) 4-formyl-2,2-dimethyldioxolane reacts with α-bromoacetate in the presence of Zn and a Zn activating agent (e.g., I 2 ) to give a 3(R)-hydroxy compound with high enantiomeric purity, i.e., an enantiomeric excess of about 98%. The 3(R)-hydroxy compound is an essential starting material for stereoselective synthesis of certain 2′-deoxynucleosides.
[0005] Thus, this invention relates to a process of reacting an aldehyde of the following formula:
wherein each of R 1 and R 2 independently is H, halo, or alkyl; or R 1 and R 2 together with the carbon atom to which they are attached are a 5 or 6-membered ring; with an ester of the following formula:
wherein each of R 3 and R 4 independently is H, halo (e.g., F), alkyl, or aryl; R 5 is alkyl or aryl, and W is Br or I; in the presence of Zn and a Zn activating agent (e.g., 1,2-dibromoethane, 1,2-diiodoethane, or I 2 ) to form an alcohol of the following formula:
wherein R 1 , R 2 , R 3 , R 4 , and R 5 are defined above.
[0006] The above reaction can be carried out with microwave, UV, or ultrasound.
[0007] To produce a nucleoside, the process includes one or more of the following steps:
[0008] (1) transforming the alcohol to a lactone of the following formula:
wherein R 3 and R 4 are as defined above;
[0009] (2) protecting the hydroxy groups of the lactone to form a protected lactone of the following formula:
wherein each of R 3 and R 4 are as defined above; and each of R 6 and R 7 , independently, is a hydroxy protecting group, or R 6 and R 7 , together, are C 1-13 alkylene;
[0010] (3) reducing the protected lactone to a furanose of the following formula:
wherein R 3 , R 4 , R 6 , and R 7 are as defined above;
[0011] (4) converting the furanose to a furan compound of the following formula:
wherein R 3 , R 4 , R 6 , and R 7 are as defined above and L is a leaving group;
[0012] (5) reacting the furan compound with a compound of the following formula:
in which R 8 is H, alkyl, or aryl; R 9 is H, alkyl, alkenyl, halo, or aryl; X is N or C—R′, R′ being H, alkyl, alkenyl, halo, or aryl; Y is an amino protecting group, and Z is a hydroxy protecting group; to produce a β-nucleoside compound of the following formula:
in which R 3 , R 4 , R 6 , and R 7 are as defined above; and B is
in which R 8 and R 9 are as defined above; and
[0013] (8) deprotecting the β-nucleoside to form a 3,5-dihydroxy β-nucleoside of the following formula:
in which R 3 , R 4 , and B are defined as above.
[0014] The term “alkyl” refers to a straight or branched hydrocarbon, containing 1-6 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, and t-butyl. The term “alkoxy” refers to an O-alkyl radical. Examples of alkoxy groups include, but are not limited to, methoxy, ethoxyl, and butoxy. The term “alkylene” refers to a alkyl diradical group. Examples of “alkylene” include, but are not limited to, methylene and ethylene.
[0015] The term “alkenyl” refers to a straight or branched hydrocarbon having one or more carbon-carbon double bonds. Examples of alkenyl groups include, but are not limited to, ethenyl, 1-butenyl, and 2-butenyl.
[0016] The term “aryl” refers to a 6-carbon monocyclic, 10-carbon bicyclic, 14-carbon tricyclic aromatic ring system. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, and anthracenyl.
[0017] The term “alkoxycarbonyl” refers to an alkyl-O-carbonyl radical. Examples of alkoxycarbonyl groups include, but are not limited to, methoxycarbonyl, ethoxycarbonyl, and t-butoxylcarbonyl. The term “aroxycarbonyl” refers to an aryl-O-carbonyl radical.
[0018] Examples of aroxycarbonyl groups include, but are not limited to, phenoxycarbonyl and 1-naphthalenoxycarbonyl. The term “aminocarbonyl” refers to a (R)(R′)N-carbonyl radical in which each of R and R′ independently is H, alkyl, or aryl. Examples of aminocarbonyl groups include, but are not limited to, dimethylaminocarbonyl, methylethylaminocarbonyl, and phenylaminocarbonyl.
[0019] Alkyl, aryl, alkenyl, and alkoxy mentioned herein include both substituted and unsubstituted moieties. Examples of substituents include, but are not limited to, halo, hydroxyl, amino, cyano, nitro, mercapto, alkoxycarbonyl, amido, carboxy, alkanesulfonyl, alkylcarbonyl, carbamido, carbamyl, carboxyl, thioureido, thiocyanato, sulfonamido, alkyl, alkenyl, alkynyl, alkyloxy, aryl, heteroaryl, cyclyl, and heterocyclyl, in which the alkyl, alkenyl, alkynyl, alkyloxy, aryl, heteroaryl, cyclyl, and heterocyclyl may be further substituted.
[0020] The term “furanose” refers to a five-membered cyclic acetal form of a sugar.
[0021] Other features, objects, and advantages of the invention will be apparent from the description and the claims.
DETAILED DESCRIPTION
[0022] Referring to Scheme 1, it was unexpectedly discovered that reacting (R) 4-formyl-2,2-dimethyldioxolane 1 with an α-bromoacetate 2 in the presence of Zn and a Zn activating agent (e.g., I 2 ) gives 3(R)-hydroxy compound 3 with high enantiomeric purity, i.e., enantiomeric excess about 98%.
[0023] Thus, this invention also features a synthetic process for stereoselectively preparing (R) 3-hydroxy compound 3 and its analogues. The synthetic process includes reacting (R) 4-formyl-2,2-dialkylldioxolane with an alkyl α-Br or α-I substituted acetate in the presence of Zn and a Zn activating agent. The Zn activating agent is a substance that activates Zn metal by reducing any oxidized Zn to atomic Zn. Examples of Zn activating agents include, but are not limited to, I 2 , 1,2-dibromoethane, or 1,2-diiodoethane.
[0024] The reactants required in this process are commercially available or can be made by methods well known in the art. To practice this process, one can mix the required reactants and a Zn activating agent in a solvent. Examples of suitable solvents include, but are not limited to, dichloromethane, tetrahydrofuran (THF), benzene, chloroform, toluene, xylene, chlorobenzene, hexane, heptane, cyclohexane, hexane, heptane, cyclohexane with ethyl acetate, isopropyl acetate, n-butyl acetate, acetonitrile, 1,2-dichloroethane, and a combination thereof. The Zn activating agent may be employed in a catalytical amount, an equimolar amount, or an excess amount, relative to one of the reactants. The reaction can be carried out at −10 to 30° C. To facilitate this reaction, microwave, UV, or ultrasound can be used. As an example, the reaction vessel can be placed in an ultrasound bath during the reaction. As recognized by those skilled in the art, the reaction time varies depending on the types and the amounts of the reactants, the reaction temperature, and the like.
[0025] The product of the above reaction, i.e., 3(R)-hydroxy compound 3, is an important starting material to stereoselectively synthesize certain nucleoside compounds. See, e.g., Chou et al. U.S. Pat. Nos. 4,965,374 and 5,434,254. Scheme 2 below illustrates a synthetic route to 2′-deoxy-2,2′-difluorocytidine from 3(R)-hydroxy compound 3.
[0026] Enantiomerically pure 3(R)-hydroxy compound 3 is hydrolyzed to form a lactone 4, namely, 2-deoxy-2,2′-difluoro-1-oxoribose, which is also enantiomerically pure. Lactone 4 has two active hydroxy groups. Before being further reacted, lactone 4 is protected by converting the two hydroxy groups into inactive groups. The protected lactone was then reduced to furanose 5 having a new hydroxy group. The reduction reaction introduces an additional chiral center at the anomeric carbon atom. As a result, 5 furanose 5 is an anomeric mixture. The new hydroxy group of furanose 5 is converted into a leaving group, e.g., methanesulfonate (see compound 6 below), and replaced with cystosine to afford protected 2′-deoxy-2,2′-difluorocytidine. The product is deprotected and purified by column chromatograph to afford the desired β anomer 7.
[0027] In the above process, several conventional chemical techniques are applied. These techniques include, e.g., introduction of a leaving group, protection and deprotection. A leaving group is a functional group that can depart, upon direct displacement or ionization, with the pair of electrons from one of its covalent bonds (see, e.g., F. A. Carey and R. J. Sundberg, Advanced Organic Chemistry, 3 rd Ed. Plenum Press, 1990). Examples of leaving groups include, but are not limited to, methanesulfonate, triflate, p-toluenesulfonate, iodide, bromide, chloride, and trifluoroacetate. Protecting groups refer to those that prevent the protected active groups from interference and can be removed by conventional methods after the reaction. Examples of hydroxy protecting groups include, but are not limited to, alkyl, benzyl, allyl, acyl (e.g., benzoyl, acetyl, or HOOC—X—CO—, X being alkylene, alkenylene, cycloalkylene, or arylene), silyl (e.g., trimethylsilyl, triethylsilyl, and t-butyldimethylsilyl), alkoxylcarbonyl, aminocarbonyl (e.g., dimethylaminocarbonyl, methylethylaminocarbonyl, and phenylaminocarbonyl), alkoxymethyl, benzyloxymethyl, and alkylmercaptomethyl. Examples of amino protecting groups include, but are not limited to, alkyl, acyl, and silyl. Hydroxy and amino protecting groups have been discussed in T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 2d. Ed., John Wiley and Sons (1991).
[0028] For the synthetic process described above, completion of the reaction can be monitored by any conventional method, e.g., ultra-violent spectrum, infrared spectrum, nuclear magnetic resonance, thin layer chromatography, gas chromatography, and high performance liquid chromatography. After the reaction is complete, the product can be separated from the reaction mixture by one or more conventional separation methods, such as chromatography, recrystalation, extraction, and distillation. It may be further purified to give higher enantiomeric purity by methods well known in the art. See, e.g., U.S. Pat. No. 5,223,608.
[0029] Without further elaboration, it is believed that the above description has adequately enabled the present invention. The following actual example is, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. All of the publications cited herein, including patents, are hereby incorporated by reference in their entirety.
Preparation of a 2,2-difluoro-3(R)-hydroxy-3-(2,2-dimethyldioxolan-4-yl)propionate
[0030] Zn (3.6 g, 57.5 mmol) and 12 (144 mg, 0.6 mmol) was added to a solution of (R)-4-formyl-2,2-dimethyldioxolane (3 g, 23 mmol) and ethyl bromodifluoroacetate (4.7 g, 23 mmol) in THF (50 mL) at 25° C. The reaction vessel was agitated in an ultrasonic bath at 5-10° C. for 12 h. A solution of ethyl bromodifluoroacetate (4.7 g, 23 mmol) in THF (5 mL) was added and the resulting solution was irradiated for additional 12 h at 10° C. The reaction was quenched by a saturated aqueous NH 4 Cl solution. The solution was filtered and concentrated in vacuo to ca. 5 mL, diluted with EtOAc (150 mL), washed with brine (15 mL), dried over Na 2 SO 4 , and concentrated in vacuo to give a crude product. The crude product was purified by flash column chromatography with 10-20% EtOAc-hexane to give a single compound of 2,2-difluoro-3(R)-hydroxy-3-(2,2-dimethyldioxolan-4-yl)propionate (4.4 g, 75% yield) as a yellow liquid.
[0031] R f =0.25 in 25% EtOAc-hexane;
[0032] 1 H NMR (500 MHz, CDCl 3 ): δ 4.05-4.335 (m, 4H), 4.01-4.04 (m, 2H), 3.29 (br, 1H), 1.32 (t, 3H, J=8 Hz), 1.30 (s, 3H), 1.29 (s, 3H);
[0033] 13 C NMR(125 MHz, CDCl 3 ): δ 163.122 (t, C, J C-F =30.5 Hz), 113.99 (dd, C, J C-F =252 Hz, 254 Hz), 109.70 (C), 73.37 (CH), 71.56(t, CH, J C-F =23 Hz), 65.60 (CH 2 ), 63.06 (CH 2 ), 26.09 (CH 3 ), 24.94 (CH 3 ), 13.74 (CH 3 ).
OTHER EMBODIMENTS
[0034] All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.
[0035] From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. For example, a 5-membered cyclic compound structurally analogous to the nucleoside compound mentioned above can also be made according to the process of the present invention. Thus, other embodiments are also within the claims. | This invention relates to a process of stereoselectively synthesizing an alcohol of the following formula:
wherein R 1 , R 2 , R 3 , R 4 , and R 5 are defined in the specification. The process includes reacting (R) 4-formyl-2,2-dimethyldioxolane with α-bromoacetate in the presence of Zn and a Zn activating agent. | 2 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to computer programming. More particularly, it relates to the production and use of optimised object code from object oriented source code.
[0002] [0002]FIG. 1 of the accompanying drawings illustrates a programming process. In order to develop a program, a computer is required, with an editor 10 and compiler 20 , in addition to a processor 30 and operating system. The operating system provides an interface to the computer's hardware, so as to enable reading and writing to the computer's disk (memory), managing the files, etc. It also enables the programmer to activate editor and compiler software. The programmer writes a sequence of instructions using editor 10 . These instructions are collectively known as source code, and are generally in ASCII format. This source code is input to the compiler 20 . The compiler performs two functions. Firstly, it checks the validity of the source code and indicates syntax errors. Then, once any errors have been corrected, and the source code has been successfully compiled, the compiler translates the source code into compiled code. This compiled code takes the form of machine instructions of the computer's processor. This developed program is executed (run) by the computer's processor 30 , which activates it through the operating system. During the development process, the results are checked for any errors in the program's logic, and the process repeated, if necessary.
[0003] The processor 30 used to run a program may be a processor of a particular platform (e.g. Macintosh, Pentium). In such a case, the compiler 20 translates the source code into machine code specific for that processor. Consequently, different object code is required for different platforms. However, alternatively, the processor 30 may be a virtual machine. A virtual machine may take the form of software installed on a computer to run a particular set of bytecodes that are platform independent. Programs may be run on the same computer on which they are written, or on another computer. If it is to be run on a different computer, the program may be loaded onto that computer or accessed remotely. FIG. 2 of the accompanying drawings illustrates a network of computers, terminals 21 - 24 and host 25 , through which remote accessing is possible. Assuming that the computers are of the same type (or they comprise a virtual machine), then the object code can be sent to and from any of the computers. For example, in an Internet scenario, if each of the terminals 21 to 24 has a Java enabled browser, then the host 25 sends Java over the net in object code format, known as bytecode. The virtual machine in each terminal's browser can understand the bytecode and interpret it into commands for the operating system of the recipient terminal (e.g., Windows, Macintosh, Solaris).
[0004] Alternatively, if, say, terminals 21 and 22 are of different types, then either the source code would need to be sent and compiled by the recipient terminal, or the host would need to determine the type of the recipient terminal and send the appropriate object code for that type.
[0005] [0005]FIG. 3 illustrates an alternative computer in the form of a handheld device 30 . As in the example of FIG. 2, object code may be stored on this device, or the device may be a wireless terminal which can access object code over a communications network 31 , 32 . The host may form part of the wireless or fixed network.
SUMMARY OF THE INVENTION
[0006] According to one aspect of the present invention there is provided an algorithm for optimising object code having a call chain of first, second and third methods, at least two of which are constructor methods, the algorithm comprising: determining whether the second method only calls the first method, and if so replacing the call from the third method to the second method with a call from the third method to the first method.
[0007] According to another aspect of the present invention there is provided a method of optimising object code, the method comprising: identifying non-operative constructors within the class hierarchy; and replacing a call to a non-operative constructor with a call to the first operative constructor in the call chain; and/or eliminating a call to a non-operative constructor when all the constructors in the call chain are non-operative.
[0008] According to a further aspect of the present invention there is provided an optimiser for optimising object code having a call chain of first, second and third methods, at least two of which are constructor methods, the optimiser comprising: a code analyser for determining whether the second method only calls the first method, and a code modifier for replacing the call from the third method to the second method with a call from the third method to the first method if the second method does only call the first method.
[0009] According to yet another aspect of the present invention there is provided an optimiser for optimising object code, the optimiser comprising: a constructor type identifier for identifying non-operative constructors within the class hierarchy; and a code modifier for replacing a call to a non-operative constructor with a call to the first operative constructor in the call chain; and/or eliminating a call to a non-operative constructor when all the constructors in the call chain are non-operative.
[0010] Aspects of the invention also extend to a device and/or system comprising an optimiser of the invention, as well as to a computer program for performing the algorithm/method of the invention and carrier, optimiser and device comprising such a program.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, of which:
[0012] [0012]FIG. 1 illustrates the programming process;
[0013] [0013]FIG. 2 illustrates a network in which a program may be run;
[0014] [0014]FIG. 3 illustrates an alternative network to that shown in FIG. 2;
[0015] [0015]FIG. 4 illustrates a program consisting of a number of classes;
[0016] [0016]FIG. 5 illustrates a modified programming process according to an embodiment of the present invention; and
[0017] [0017]FIG. 6 illustrates a terminal device according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention is concerned with alleviating overheads inherent in object oriented programs. A brief summary of the fundamentals of object oriented programming is outlined below, so as to facilitate understanding of the present invention. Java is used as an exemplary object oriented programming language, but it will be appreciated that the invention may extend to other languages.
[0019] A Java program consists of classes, as illustrated in FIG. 4. The program in FIG. 4 has four classes: Object, Mammal, Feline and Cat. Each class inherits from the class above it. For example, Cat inherits from Feline.
[0020] The properties of a class include its name, structure (data members) and capabilities (methods). Take, for example, the code in Example 1. public class Mammal indicates the class name as Mammal, and that the class inherits from class Object (classes inherit from class Object by default, as is the case here; inheritance from other classes can be specified by the keyword extends). Next, the class includes a declaration private int numLegs=2, which is an integer number. The declaration sets aside storage in the computer's memory for each instance of this class, the amount of which depends on the type. Finally the class comprises a method public int legs ( ). That is, the method is called legs. A method definition includes the method name, return type and any parameters, followed by declarations and statements (instructions). In Example 1, the method legs has a return type statement, return numLegs. Other statement types include assignment, invocation, repetition, selection and exception.
[0021] The structure of a Java program includes a class name, followed by a main method including any declarations and statements. In Example 1 the program has the class name createMammal. The main method is a void static method, indicating that it is a class method and doesn't return anything. It invokes a method callA that, in turn, creates an instance of Mammal (named myMammal) and invokes the legs method of class Mammal on this instance. When the Java virtual machine (JVM) is activated, it is given the name of the class containing the main method (createMammal in this case), and then looks for the method named main in that class and starts running it from there.
EXAMPLE 1
[0022] [0022] //Mammal.java public class Mammal { private int numLegs = 2; public int legs () { return numLegs; } } //createMammal.java public class createMammal { public static void main (String args []) { callA (); } public static void callA () { Mammal myMammal = new Mammal (); myMammal.legs (); } }
[0023] Java has a number of mechanisms dedicated to ensuring proper initialisation of objects. One such mechanism is a constructor. A constructor is called when an object is created in the program. In source code, a constructor looks like a method declaration that does not have a return type. The programmer may define constructors. In the absence of constructors defined by the programmer, the compiler will add a default constructor, a constructor that takes no parameters and simply invokes the superclass constructor without arguments. Example 2 illustrates source code with no constructors for class Mammal. As in the previous example, public class Mammal indicates the class name as Mammal, and that the class inherits from class Object. Since class Mammal comprises no explicit constructor, the compiler adds a default constructor that simply invokes the constructor of class Object without arguments. Thus, class Mammal is compiled as if the programmer had defined an empty constructor:
public class Mammal { public Mammal () { } } or, even more explicitly: public class Mammal { public Mammal () { super (); } }
[0024] A constructor always takes the name of the class. The createMammal class has a method callA that creates myMammal as a Mammal which inherits features of its superclass. When the new operator (e.g. Mammal myMammal=new Mammal( )) is called, the JVM allocates memory for a new object, prepares the memory with well-known values, and initialises that memory by calling a constructor. Thus, the JVM ensures that initialisation code is run before the newly allocated memory can be used.
EXAMPLE 2
[0025] [0025] //Mammal.java public class Mammal { } //createMammal.java public class createMammal { public static void main (String args []) { callA (); } public static void callA () { Mammal myMammal = new Mammal (); } }
[0026] A constructor of a class may invoke another constructor of the same class. This is achieved using the this ( ) statement. This is shown in Example 3. In this case, the constructor with no parameters (public Mammal ( )) invokes the other constructor (public Mammal (int legs)) and passes 2 to the other constructor, which assigns that value to numlegs.
[0027] When a class is compiled, the Java compiler generates an instance initialisation method for each constructor in that class. This method is given a reserved name, <init>, and has the constructor return type (void) and parameters of the constructor from which it is generated.
EXAMPLE 3
[0028] [0028] //Mammal.java public class Mammal { private int numLegs; public Mammal () { this (2); } public Mammal (int legs) { numLegs = legs; } }
[0029] The <init> method is not actually part of the Java language, but is something which the JVM expects to see in a Java class file. Hence, it should be understood here that when the term <init> method is used, it is synonymous with constructor method.
[0030] The first statement (instruction) in an <init> method will be a call (invocation) to another <init> method in the same class (the this( ) invocation), or a call to the superclass's <init> method (the super( ) invocation). (The only exception to this rule is that class Object's <init> method does not call its superclass's <init> method because Object has no superclass; Object's <init> method actually does nothing.)
[0031] Taking the class hierarchy in FIG. 4, when constructing an instance of Cat (with new Cat ( )), the following methods will be called in the order as listed (assuming for simplicity that there is only one constructor per class): Cat.<init>, Feline.<init>, Mammal.<init>, Object.<init>.
[0032] Naturally, constructors can perform other tasks than calling their superclass's constructor. However, the constructors often contain no other code than the call to the superclass's constructor (super( )). This is inefficient both in terms of speed and space.
[0033] The present invention addresses this. FIG. 5 illustrates a modified programming process according to an embodiment of the present invention. As can be seen, the process involves a Java editor 50 , a compiler 51 and a processor (JVM) 53 as in the prior art of FIG. 1. However, it also comprises an optimiser 52 . The compiler of this embodiment of the invention is a conventional compiler comprising a conventional syntax error checker 510 , translator 511 and code generator 512 . Accordingly, the compiler checks the validity of the source code, indicates any compilation or syntax errors, and once the errors have been corrected and the source code successfully recompiled, it translates and generates the object code (.class file). However, rather than forwarding this object code directly to the JVM 53 , the code generator 512 forwards it to the optimiser 52 . The optimiser optimises the object code, for example, using one of the techniques explained below, and outputs an optimised object code (.class2 file) to the JVM 53 . The JVM 53 , in turn, executes the program.
[0034] Whilst the optimiser is illustrated as separate from the compiler in FIG. 5, it will be appreciated that it could actually form part of the compiler.
[0035] The optimiser 52 aims to alleviate constructor overhead on the following basis. Firstly, it can be determined statically from the bytecode whether a constructor performs any function other than calling its superclass's constructor. Secondly, it can also be determined statically, from anywhere in the code, which class's constructor is being called. The latter is true in Java, for example, because the constructors are called only by the instruction invokespecial, which is specified to be statically resolved. In an embodiment of the present invention, this principle may be implemented by the optimiser 52 in accordance with the following routine.
[0036] Optimiser Routine
[0037] (1) Starting from the top of the class hierarchy, each <init> method of each class is examined. Let's call such a method “init 1”.
[0038] If init 1 contains no other code than a call to another <init> method that takes no parameter, then init 1 is marked as non-operative.
[0039] Follow the chain of <init> method calls from init 1, and
[0040] If all the methods in that chain were marked earlier as non-operative, eliminate the call to <init> in init 1;
[0041] Otherwise, replace the call to <init> in init 1 with a call to the first <init> method in the call chain that was not marked as non-operative.
[0042] (2) Examine all other methods than <init> methods. In these methods, examine each call to an <init> method. Let's call such a call “call 1”.
[0043] If call 1's callee was not marked as a non-operative method in step 1 , processing of call 1 is stopped;
[0044] Otherwise, call 1's callee is examined. In this case:
[0045] If call l's callee has a call to an <init> method, then we know that that <init> method was not marked as a non-operative method in step 1 : hence call 1 is replaced with a call to that <init> method;
[0046] Otherwise, call1 is eliminated.
[0047] (3) Since the constructors marked as non-operative are not used any further, then they may optionally be removed altogether (assuming that they form a closed set and cannot be called by other classes; otherwise, this step must not be performed).
[0048] This technique removes all the non-operative constructors from Java class files. Thus, the resultant modified Java class file (e.g. .class2 file in FIG. 5) is smaller than the original (e.g. class file in FIG. 5), resulting in space savings. In addition, many object constructions are considerably sped up because only the useful parts of the constructors of the original Java class file are retained by the optimiser in the modified file.
[0049] The optimiser that implements this routine may form part of any of the communications devices in FIGS. 2 and 3. In a preferred embodiment, the optimiser forms part of a terminal device, for example as illustrated in FIG. 6. The terminal device 60 of FIG. 6 may download files of object code from the communications network and also retrieve local files stored in the device's memory 61 .
[0050] Code received from the network (e.g. class file) is input to the JVM's verifier 632 and is verified prior to input to the optimiser 62 . The optimiser 62 , in turn, optimises the code in accordance with the present invention, and the resultant optimised code (e.g. .class2 file) is then forwarded to the JVM's interpreter 631 for interpretation and execution.
[0051] In contrast, local files are preprocessed once by the optimiser 62 for optimisation according to the present invention. They are then stored, in optimised format in memory 61 . It is usual practice for a JVM verifier 632 to be run on downloaded files, but not local ones. Hence, in this embodiment the optimised local files (e.g. .class2 files) are forwarded directly to the interpreter 631 for interpretation and execution, bypassing the verifier 632 .
[0052] In an alternative embodiment, the optimiser may form part of an MSC/BSC. In this case, the MSC/BSC may receive and/or store object code (e.g. class file) and optimise that code in accordance with the present invention (e.g. .class2 file), prior to transmitting it to the recipient terminal. The recipient terminal may then run the received optimised code. Such a solution is advantageous if the recipient terminal is a dummy terminal (in that it receives all object code from a remote server), as it eliminates the need for an optimiser in such a terminal. However, either the optimised code would need to bypass verification (e.g. by turning the verifier of a conventional JVM off) in order for it to run, or a conventional verifier would need to be modified to exclude the current requirement that an <init> method (except Object.<init>) must start with a call to an <init> method.
[0053] Of course, a hybrid arrangement is also possible in which the optimiser is provided both in the network (e.g. MSC/BSC) for downloaded files and in the terminal for local files.
[0054] Optimising code according to an embodiment of the present invention will now be described with reference to an example (Example 4).
[0055] Let us note that since the constructors of classes A, C and D contain no statement in the source code, the programmer could leave them out. In this case, the compiler would automatically generate constructors (default constructors) identical to the ones shown here, resulting in exactly the same bytecodes.
[0056] In the programming process of FIG. 5, the source code of Example 4 may be output from the Java editor 50 and forwarded to the compiler 51 . As mentioned above, the compiler of this Figure comprises a conventional syntax error checker 510 , translator 511 , and code generator 512 . Accordingly, the compiler checks the validity of the source code, indicates any compilation or syntax errors, and once the errors have been corrected and the source code successfully recompiled, it translates and generates the object code (.class file), the bytecodes of which are shown below. (The files Object.class, A.class, etc., actually contain binary data; only their disassembled form is shown here.)
EXAMPLE 4
Source Code
[0057] [0057] // Object.java class Object { Object() {} [...] } // A.java class A extends Object { A() { } // B.java class B extends A { B() { System.out.println(“Hello!”); } } // C.java class C extends B { C() {} } // D.java class D extends C { D() {} } // App.java class App { public static void main(String[] args) { B b = new B(); D d = new D(); A a = new A(); } }
EXAMPLE 4
Bytecode
[0058] [0058] // Object.class (disassembled) .class public java/lang/Object .method public <init>()V return .end method // A.class (disassembled) .class A .super java/lang/Object .method <init>()V aload_0 invokespecial java/lang/Object/<init>()V return .end method // B. class (disassembled) .class B .super A .method <init>()V aload_0 invokespecial A/<init>()V getstatic java/lang/System/out Ljava/io/PrintStream; ldc “Hello!” invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V return .end method // C. class (disassembled) .class C .super B .method <init>()V aload_0 invokespecial B/<init>()V return .end method // D. class (disassembled) .class D .super C .method <init>()V aload_0 invokespecial C/<init>()V return .end method // App. class (disassembled) .class App .super java/lang/Object .method public static main([Ljava/lang/String;)V new B dup invokespecial B/<init>()V astore_1 new D dup invokespecial D/<init>()V astore_2 new A dup invokespecial A/<init>()V astore_3 return .end method
[0059] Example 4 illustrates the class hierarchy Object.java, A.java, B.java, C.java, D.java and App.java.
[0060] The Object class, which is part of the Java library, contains a constructor with no parameters, Object( ). Since class Object has no superclass, Object( ) does not invoke any superclass constructor; instead, this constructor just returns. (The Object class has a lot of code in addition to Object( ), but that code is not relevant to our discussion and therefore is not shown.)
[0061] The A class inherits from the Object class, by virtue of the code class A extends Object. The A class is declared to have a single method. Since this method, A( ), is a constructor, it takes on the name of the class. Furthermore, it invokes a constructor of the next class in the hierarchy (i.e. of the class Object in this example). (Let us recall that since the statement super ( ) is not explicitly stated in this method, it is automatically generated by the compiler to invoke Object ( ))
[0062] The B class inherits from the A class, by virtue of the code class B extends A. The class itself comprises a constructor, B ( ), with no parameter. This constructor has a statement, System.out.print1n(“Hello!”);, which prints a string onto the standard output. In addition, this constructor invokes a constructor of the next class in the hierarchy (i.e. of the class A in this example).
[0063] The C class inherits from the B class, by virtue of the code class C extends B. The C class is declared to have a single method. Since this method, c ( ), is a constructor, it takes on the name of the class. Furthermore, it invokes a constructor of the next class in the hierarchy (i.e. of the class B in this example).
[0064] The D class inherits from the C class, by virtue of the code class D extends C. The D class is declared to have a single method. Since this method, D ( ), is a constructor, it takes on the name of the class. Furthermore, it invokes a constructor of the next class in the hierarchy (i.e. of the class C in this example).
[0065] The App class contains the program. It comprises a method, namely the main method. When the JVM is activated, it is given the name of the class, and then looks for the method named main in that class and starts running it from there (main must be declared public, static and returning void). This method contains three object creations, creating new instances of classes B, D and A.
[0066] In the programming process of FIG. 5, after the compiler has successfully generated the object code (.class file), it forwards it to the optimiser 52 . Let us now expose how the optimiser routine described above works in Example 4.
[0067] In step 1 of the optimiser routine described above, the optimiser optimises the object code by examining each individual .class file, in the order Object, A, B, C, D, looking for constructors that only call the superclass's constructor (or even, in the case of Object ( ), do nothing but return), marking these methods as non-operative in the .class file and following the chain of constructor calls to replace calls to a respective superclass's constructor with a call to the first operational constructor above it in the hierarchy.
[0068] Step 1 is shown below for Example 4.
EXAMPLE 4
Optimiser (Step 1 )
[0069] [0069] // Object.class (disassembled) .class public java/lang/Object .method public <init>()V NON-OPERATIVE return .end method // A.class (disassembled) .class A .super java/lang/Object .method <init>()V NON-OPERATIVE aload_0 invokespecial java/lang/Object/<init>()V this call is eliminated return .end method // B. class (disassembled) .class B .super A .method <init>()V OPERATIVE aload_0 invokespecial A/<init>()V this call is eliminated getstatic java/lang/System/out Ljava/io/PrintStream; ldc “Hello!” invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V return .end method // C. class (disassembled) .class C .super B .method <init>()V NON-OPERATIVE aload_0 invokespecial B/<init>()V this call is left unchanged return .end method // D. class (disassembled) .class D .super C .method <init>()V NON-OPERATIVE aload_0 invokespecial C/<init>()V this call is replaced by: invokespecial B/<init>()V return .end method // App. class (disassembled) .class App .super java/lang/Object .method public static main([Ljava/lang/String;)V new B dup invokespecial B/<init>()V astore_1 new D dup invokespecial D/<init>()V astore_2 new A dup invokespecial A/<init>()V astore_3 return .end method
[0070] The constructor of class Object (Object.<init>) does nothing but returns. Therefore, it is marked as non-operative.
[0071] The constructor of class A (A.<init>) contains no other code than a call to another <init> method. Therefore, it is marked as non-operative. Furthermore, since the chain of <init> methods called from A.<init> consists solely of Object.<init>, and since Object.<init> was marked as non-operative, the call to Object.<init> (and its associated instruction a_load0) is eliminated from A.<init>.
[0072] The constructor of class B (B.<init>) contains other code than a call to another <init> method. Therefore, it is not marked as non-operative (i.e., it is marked as operative). Furthermore, since the chain of <init> methods called from B.<init>consists of A.<init> and Object.<init>, and since both A.<init> and Object.<init> were marked as non-operative, the call to A.<init> (and its associated instruction a_load0) is eliminated from B.<init>.
[0073] The constructor of class C (C.<init>) contains no other code than a call to another <init> method. Therefore, it is marked as non-operative. Furthermore, since the chain of <init> methods called from C.<init> consists of B.<init>, A.<init> and Object.<init>, and since one of these <init> methods, B.<init>, was marked as operative, the call to B.<init> (and its associated instruction a_load0) is not eliminated from C.<init>. And then, since the first <init> method that was not marked as non-operative in the chain of <init> methods called from C.<init> is B.<init>, the call to B.<init> is replaced by itself; that is, the call to B.<init> is left unchanged in C.<init>.
[0074] The constructor of class D (D.<init>) contains no other code than a call to another <init> method. Therefore, it is marked as non-operative. Furthermore, since the chain of <init> methods called from D.<init> consists of C.<init>, B.<init>, A.<init> and Object.<init>, and since one of these <init> methods, B.<init>, was marked as operative, the call to C.<init> (and its associated instruction a_load0) is not eliminated from D.<init>. And then, since the first <init> method that was not marked as non-operative in the chain of <init> methods called from D.<init> is B.<init>, the call to C.<init> is replaced by a call to B.<init>.
[0075] The disassembled bytecodes for Example 4 after step 1 are shown below.
EXAMPLE 4
Optimiser (After Step 1 )
[0076] [0076] // Object.class (disassembled) .class public java/lang/Object .method public <init>()V NON-OPERATIVE return .end method // A.class (disassembled) .class A .super java/lang/Object .method <init>()V NON-OPERATIVE return .end method // B. class (disassembled) .class B .super A .method <init>()V OPERATIVE getstatic java/lang/System/out Ljava/io/PrintStream; ldc “Hello!” invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V return .end method // C. class (disassembled) .class C .super B .method <init>()V NON-OPERATIVE aload_0 invokespecial B/<init>()V return .end method // D. class (disassembled) .class D .super C .method <init>()V NON-OPERATIVE aload_0 invokespecial B/<init>()V return .end method // App. class (disassembled) .class App .super java/lang/Object .method public static main([Ljava/lang/String;)V new B dup invokespecial B/<init>()V astore_1 new D dup invokespecial D/<init>()V astore_2 new A dup invokespecial A/<init>()V astore_3 return .end method
[0077] In step 2 of the optimiser routine described above, the optimiser optimises the object code by examining all other methods than <init> methods in each individual .class file, in any order, looking for calls to <init> methods, and possibly replacing these calls by more efficient ones.
[0078] Step 2 is shown below for Example 4.
EXAMPLE 4
Optimiser (Step 2 )
[0079] [0079] // Object.class (disassembled) .class public java/lang/Object .method public <init>()V NON-OPERATIVE return .end method // A.class (disassembled) .class A .super java/lang/Object .method <init>()V NON-OPERATIVE return .end method //B. class (disassembled) .class B .super A .method <init>()V OPERATIVE getstatic java/lang/System/out Ljava/io/PrintStream; ldc “Hello!” invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V return .end method // C. class (disassembled) .class C .super B .method <init>()V NON-OPERATIVE aload_0 invokespecial B/<init>()V return .end method // D. class (disassembled) .class D .super C .method <init>()V NON-OPERATIVE aload_0 invokespecial B/<init>()V return .end method // App. class (disassembled) .class App .super java/lang/Object .method public static main([Ljava/lang/String;)V new B dup invokespecial B/<init>()V this call is left unchanged astore_1 new D dup invokespecial D/<init>()V this call is replaced by: astore_2 invokespecial B/<init>()V new A dup invokespecial A/<init>()V this call is eliminated astore_3 return .end method
[0080] In this example, all the calls to <init> methods from non <init> methods are located in App.main. Let us review each of these three calls.
[0081] B.<init> was marked as operative. Therefore, the call to B.<init> is left unchanged in App.main.
[0082] D.<init> was marked as non-operative. Furthermore, D.<init> contains a call to B.<init>. Therefore, the call to D.<init> is replaced by a call to B.<init> in App.main.
[0083] A.<init> was marked as non-operative. Furthermore, A.<init> contains no call to any <init> method. Therefore, the call to A.<init> (and its associated instruction dup) is eliminated from App.main.
[0084] The disassembled bytecodes after step 2 are shown below.
EXAMPLE 4 Optimiser (after step 2) // Object.class (disassembled) .class public java/lang/Object .method public <init>()V NON-OPERATIVE return .end method // A.class (disassembled) .class A .super java/lang/Object .method <init>()V NON-OPERATIVE return .end method // B. class (disassembled) .class B .super A .method <init>()V OPERATIVE getstatic java/lang/System/out Ljava/io/PrintStream; ldc “Hello!” invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V return .end method // C. class (disassembled) .class C .super B .method <init>()V NON-OPERATIVE aload_0 invokespecial B/<init>()V return .end method // D. class (disassembled) .class D .super C .method <init>()V NON-OPERATIVE aload_0 invokespecial B/<init>()V return .end method // App. class (disassembled) .class App .super java/lang/Object .method public static main([Ljava/lang/String;)V new B dup invokespecial B/<init>()V astore_1 new D dup invokespecial B/<init>()V astore_2 new A astore_3 return .end method
[0085] In step 3 of the optimiser routine described above, the optimiser optimises the object code by removing all the <init> methods that were marked as non-operative. (Let us recall that this step is optional and may only be performed if the classes to be modified form a closed set, because if not the <init> methods could be called by other classes and therefore cannot be removed.)
[0086] Step 3 is shown below for Example 4.
EXAMPLE 4
Optimiser (Step 3 )
[0087] [0087] // Object.class (disassembled) .class public java/lang/Object [<init>()V removed] // A.class (disassembled) .class A .super java/lang/Object [<init>()V removed] // B.class (disassembled) .class B .super A .method <init>()V getstatic java/lang/System/out Ljava/io/PrintStream; ldc “Hello!” invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V return .end method // C. class (disassembled) .class C .super B [<init>()V removed] // D. class (disassembled) .class D .super C [<init>()V removed] // App. class (disassembled) .class App .super java/lang/Object .method public static main([Ljavallang/String;)V new B dup invokespecial B/<init>()V astore_1 new D dup invokespecial B/<init>()V astore_2 new A astore_3 return .end method
[0088] The present invention includes any novel feature or combination of features disclosed herein either explicitly or any generalisation thereof irrespective of whether or not it relates to the claimed invention or mitigates any or all of the problems addressed.
[0089] In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention. | The present invention concerns an algorithm for optimising object code having a call chain of first, second and third methods, at least two of which are constructor methods. The algorithm comprises determining whether the second method only calls the first method, and if so replacing the call from the third method to the second method with a call from the third method to the first method. This code optimising algorithm is performed by an optimiser (52), which may for example, be implemented in a communications device, such as a terminal device (60) | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to the recovery of alkanolamines from wash or scrubbing streams used to remove acid gasses from gas streams. More particularly, the present invention relates to such a process in which carbamates formed during the gas scrubbing operation are converted back to the alkanolamine.
BACKGROUND OF THE INVENTION
[0002] The removal of acid gases, e.g. hydrogen sulfide, carbonyl sulfide, and carbon dioxide, from industrial and natural gas streams is an important and frequently encountered operation in the process industry. It is known that in these processes, certain of the alkanol amines used react with carbon dioxide to form carbamate precursors. The formation of the carbamate precursors is detrimental to the scrubbing process since they can cause corrosion, have no acid gas removal properties and reduce solution capacity.
[0003] Historically, thermal reclaimers have been used to remove nonvolatile contaminants from the used scrubbing or wash solution. However, these thermal reclaimers pose difficulties in that high temperatures, long residence time, and dehydrating environment are typically encountered in such reclaimers. Moreover, there are many problems with conventional reclaimer designs and operations. In particular, in the high temperature dehydrating environment encountered in conventional thermal reclaimers, the carbamate precursors can be converted into amino ethers with permanent, concomitant loss of the alkanolamine. This presents a large problem since major loss of the alkanolamine translates into significant chemical replacement costs in the overall gas scrubbing operation. It is known that the production of these amine ethers in conventional recovery processes is accelerated by increased temperature and exposed residence times in the reclaimer.
[0004] Using diglycolamine (DGA) as an example, in the scrubbing operation, the DGA reacts with CO2 to form a carbamate precursor. The carbamate precursor can react with DGA to form N,N,bis(hydroxyethoxyethyl)urea (BHEEU). The BHEEU, at the high temperatures in a typical thermal reclaimer, can irreversibly degrade to morpholine, an amino ether, and DGA. Accordingly, there is a net loss of DGA from the system.
[0005] The equations below show the reaction sequence:
[0000]
[0006] FIG. 3 is a graph taken from a paper entitled Saudi Arabian Experience with DGA Units and Related Sulfur Plants, by Lewis G. Harruff, Saudi Arabian Oil Co. It shows the relationship between morpholine make, temperature and residence time.
SUMMARY OF THE INVENTION
[0007] In one aspect, the present invention provides a continuous process for recovering an alkanolamine from a wash or scrubbing stream used to remove acid gases from gas streams.
[0008] In another aspect, the present invention provides a dynamic process which maximizes recovery of an alkanolamine from a wash or scrubbing stream used to remove acid gases from gas streams.
[0009] In yet another aspect, the present invention provides a combined reaction/reclaiming process for the recovery of an alkanolamine from a scrubbing or washing solution used to remove acid gases from gas streams.
[0010] These and further features and advantages of the present invention will become apparent from the following detailed description, wherein reference is made to the figures in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a schematic flow sheet of one embodiment of the process of the present invention.
[0012] FIG. 2 shows a schematic flow sheet of another embodiment of the process of the present invention.
[0013] FIG. 3 is a graph showing the effect of morpholine formation as a function of temperature.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] While the invention will be described with respect to the recovery of DGA from a wash solution used to scrub acid gases from gas streams, particularly hydrocarbon streams, it will be understood that it is not so limited.
[0015] The process of the present invention can be used to recover any alkanolamine used in a gas scrubbing operation to remove acid gases from gas streams wherein in the reclaiming process to recover the alkanolamine for further use, the alkanolamine can react with carbamate precursors formed during the gas scrubbing operation to irreversibly produce compounds e.g., amine ethers which consume the alkanolamine. Non-limiting examples of alkanolamines include monoethanolamine (MEA), diethanolamine (DEA), diglycolamine (DGA), methydiethanolamine (MDEA) as well as mixed amines, e.g., mixtures of MDEA and DEA or MEA. It is well known for example that MDEA based mixtures are used to increase the CO 2 pickup in cases where the MDEA is allowing too much CO 2 to slip overhead in the absorber. Accordingly, spiking the MDEA with MEA or DEA provides advantages.
[0016] Referring now to the figures and particularly FIG. 1 , a spent gas scrubbing medium comprising DGA, water, carbamate precursors and other contaminants and byproducts removed from the scrubbing operation is introduced via line 10 and pump 12 into reaction vessel 14 , the feed stream in line 10 passing through an exchanger 16 where it is preheated prior to entering the reaction zone in vessel 14 . Exchanger 16 can be heated in any suitable fashion well known to those skilled in the art.
[0017] The reaction zone in vessel 14 is conducted at a positive pressure which can range up to 250 psig and at a temperature of from about 250° F. to about 400° F. depending upon the composition of the feed stream. A product stream is removed from the reaction zone in vessel 14 via line 18 and is pumped by pump 20 through an exchanger 22 into a product tank 24 . A portion of the product stream in line 18 is recycled via line 26 to the incoming feed stream in line 10 prior to heat exchanger 16 .
[0018] An overhead stream of CO 2 , water and some DGA is removed from vessel 14 and transferred via line 28 and exchanger 30 into product tank 24 . In exchanger 30 , carried over DGA is condensed and in this regard the cooling medium can comprise the feed stream being introduced via line 10 . This feed stream can also be used as the cooling medium in exchanger 22 . CO 2 is vented from product tank 24 via line 32 while product in product tank 24 is removed via line 34 and pumped via line 36 into storage for further use or back into the gas scrubbing process.
[0019] As noted above from this description, the feed stream is being recirculated in the reaction zone in vessel 14 by virtue of the recycle loop comprised of line 18 , pump 20 , and line 26 . It is this recycle loop which controls the residence time of the feed mixture in the reaction vessel 14 and which ensures that the amount of amine ethers being made is minimized and that there is maximum recovery of the DGA. It will be recognized that the residence time is also controlled by the composition of the feed mixture. In this regard, the incoming feed can be monitored to determine the amount of BHEEU. Alternatively, or concomitantly, the product stream exiting reaction vessel 14 via line 18 can also be monitored to determine its composition so as to increase or decrease temperature and the recycle time as necessary.
[0020] Accordingly, temperature, recycle rate and hence residence time in the reaction zone in reaction vessel 14 are optimized to, in the case of the use of DGA, minimize the make of morpholine.
[0021] In this regard, the reactor provides sufficient residence time, e.g. from about 0.5 to 1 hour, to allow the reaction of BHEEU to DGA to go to completion. As was noted above, the reaction of BHEEU to form DGA and morpholine is favored at high temperatures. Accordingly, it has been found that one of the better methods to control temperature in the reaction zone is by the use of steam at about 100 to 175 psig to ensure that temperatures of 400° F., preferably 365° F., or higher are avoided. If higher pressure (hotter) steam or alternate heat mediums are used then the temperature must be carefully controlled. All in all, the system is operated such that overheating in the reaction zone is avoided.
[0022] Referring now to FIG. 2 , there is shown another embodiment of the present invention wherein reaction vessel 14 is used as a pressurized flash tank. The feed stream comprising DGA, water, carbamate precursor and other contaminants from the gas scrubbing operation is introduced via line 38 , pump 40 and exchanger 42 into flash tank 46 . As noted, flash tank 46 is operated under pressure and the residence time of the circulating feed mixture in vessel 46 will generally be as described above with respect to the embodiment shown in FIG. 1 , i.e., residence times will again be maintained to be within 0.5 to 1 hour, as discussed above, vessel 46 being operated in a temperature range of from about 330° F. to about 380° F. to ensure best conversion and hydrolysis of the BHEEU. Heat exchanger 42 requires either 250° F., 250 psig steam or some alternate heating medium, such as hot oil, and will operate at about 388° F. (in general greater than 330° F.) to provide the additional heat of vaporization required in flash vessel 46 . In operation, the feed stream in flash vessel 46 is flashed and is therefore held at a substantially constant temperature of from about 330° F. to about 375° F., preferably about 360° F.
[0023] The overhead flashed stream from flash vessel 46 is removed via line 48 and transferred through cooling condenser 50 into product tank 52 . To maximize DGA recovery and handle residue, a bottoms stream is removed from flash vessel 46 via line 54 and transferred via pump 56 into a wiped film evaporator 58 . A portion of the stream in line 54 is recycled via recycle line 60 into feed stream 38 and then into flash vessel 46 .
[0024] It may be necessary to introduce a caustic solution into flash vessel 46 . To this end, there is a line 41 having a valve 43 such that the amount of caustic or alkaline solution introduced into flash vessel 46 can be controlled.
[0025] It will be appreciated that the bottoms stream leaving flash vessel 46 via line 54 , although containing primarily unwanted residue, also contains significant amounts of DGA. Accordingly, the liquid from the flash tank 46 leaving via line 54 is treated in wiped film evaporator 58 . Wiped film evaporator 58 is operated under vacuum, e.g., from about 760 to 1 TOR. In wiped film evaporator 58 , the residue is further concentrated and removed as a waste stream 62 and sent for suitable disposal. In most cases, about 20% of the feed to flash tank 46 is slip streamed into wiped film evaporator 58 to provide additional concentration of residue. Vacuum conditions in wiped film evaporator 58 are provided by a vacuum system, shown generally as 64 , via line 66 . It will be appreciated that the vacuum can be provided by steam jets, a vacuum pump, etc. and that vacuum system 64 can include the usual vacuum train to recover materials removed from wiped film evaporator 58 .
[0026] Since wiped film evaporator 58 has an integral condenser, the DGA is condensed and transferred via line 68 and pump 70 into product tank 52 . Again, product tank 52 is provided with a vent 72 for CO 2 and any other uncondensable gases. Product from product tank 52 can be transferred via line 72 and pump 74 back into the gas processing operation or for storage and later use. It will be appreciated that the vacuum system 64 may recover waste products which can be transferred to waste stream 62 for appropriate disposal. It will further be appreciated that various valves, gauges, etc., commonly used have not been shown for simplicity's sake.
[0027] As can be seen from the above, the present invention provides a dynamic reaction process which avoids loss of DGA by maximizing the conversion of BHEEU and the subsequent recovery of the DGA. Additionally, the present invention provides such a dynamic reaction system in conjunction with a waste recovery system, using a wiped film evaporator, to further recover DGA and remove waste from the system for proper disposal.
[0028] Although specific embodiments of the invention have been described herein in some detail, this has been done solely for the purposes of explaining the various aspects of the invention, and is not intended to limit the scope of the invention as defined in the claims which follow. Those skilled in the art will understand that the embodiment shown and described is exemplary, and various other substitutions, alterations and modifications, including but not limited to those design alternatives specifically discussed herein, may be made in the practice of the invention without departing from its scope. | A process for recovering an alkanolamine from a used gas scrubbing stream wherein a dynamic reaction system is employed to maximize conversion of bis-urea compounds typically formed in the gas scrubbing operation into the alkanolamine and minimize the formation of amino ethers which irreversibly convert the alkanolamine. A method of removing waste products from the system by the use of a wiped film evaporator. | 2 |
TECHNICAL FIELD
[0001] The technical field generally relates to slurry hydrocracking, and more particularly to methods and systems for slurry hydrocracking with reduced feed bypass.
BACKGROUND
[0002] Slurry hydrocracking methods involve the processing of a heavy feed stock, such as vacuum residues, and fine particulate catalyst in an upflow reactor in a hydrogen-rich environment. This reaction environment facilitates the very high conversion of the heavy feed stock to liquid products, particularly distillate boiling-range components.
[0003] A typical slurry hydrocracking method includes introducing a heated heavy feed stock into a slurry hydrocracking (SHC) reactor. An effluent from the SHC reactor is directed to a separation zone (which may include, e.g., vacuum distillation) for recovery of light ends, naphtha, diesel range distillate, vacuum gas oils and unconverted heavy feed (pitch).
[0004] Conventional slurry hydrocracking methods, however, present several challenges. For instance, toluene insoluble material can accumulate in the SHC reactor leading to increased coking. Further, an amount of unconverted pitch and vacuum gas oils may leave the SHC reactor before being converted into more desirable components. That is, a portion of the effluent leaving the slurry reactor typically includes an amount of unconverted pitch (that may have a boiling point greater than about 975° C.) and vacuum gas oil that may be as much as 1-3% of the feed.
[0005] Accordingly, it is desirable to provide methods and systems that allow for reducing toluene insoluble material, an in particular mesophase materials, in the SHC reactor. In addition, it is desirable to provide methods and systems that reduce feed bypass. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and appended claims, taken in conjunction with the accompanying drawings and this background of the invention.
BRIEF SUMMARY
[0006] Methods and systems for slurry hydrocracking with reduced feed bypass, and methods for modulating an amount of toluene insoluble material, and in particular mesophase material, present in a slurry hydrocracking reactor are provided. An exemplary slurry hydrocracking method comprises the steps of: combining a hydrocarbon feed and a slurry hydrocracking catalyst or catalyst precursor to generate a slurry hydrocracking feed, and introducing the slurry hydrocracking feed to a slurry hydrocracking reactor in the presence of hydrogen and under hydrocracking conditions suitable to generate a first product stream comprising one or more of naphtha, middle distillate, light vacuum gas oil, heavy vacuum gas oil, and pitch. A drag stream comprising a hydrocarbon, mesophase material, and solid catalyst particles is also drawn from the slurry hydrocracking reactor. The drag stream is separated into a first separated stream and a recycle stream. The first separated stream comprises mesophase material and solid catalyst particles, and the recycle stream comprises the hydrocarbon. The recycle stream is directed back to the slurry hydrocracking reactor.
[0007] In another embodiment, methods of modulating an amount of toluene insoluble material, and in particular mesophase material, present in a slurry hydrocracking reactor are provided. In an exemplary embodiment, a method includes the steps of: introducing a first hydrocarbon hydrogen, and a slurry hydrocracking catalyst into a slurry hydrocracking reactor under hydrocracking conditions suitable to generate a slurry hydrocracking effluent. In this embodiment, the hydrocracking conditions further result in generation of toluene insoluble material, including mesophase material and catalyst solids, in the reactor. A drag stream is drawn from the slurry hydrocracking reactor, wherein the drag stream comprises a second hydrocarbon, mesophase material, and solid catalyst particles. The drag stream is separated into a first separated stream and a recycle stream, with the first separated stream comprising mesophase material and solid catalyst particles, and the recycle stream comprising the second hydrocarbon. The amount of mesophase material and catalyst particles in the recycle stream is reduced relative to an amount present in the drag stream. The recycle stream is directed back to the slurry hydrocracking reactor.
[0008] In another embodiment, systems for slurry hydrocracking are provided. In an exemplary embodiment, a system comprises: a slurry hydrocracking reactor configured to receive a slurry under hydroprocessing conditions effective to form a product effluent. The slurry comprises a first hydrocarbon, and the product effluent comprising one or more of naphtha, middle distillate, light vacuum gas oil, heavy vacuum gas oil, and pitch. The slurry hydrocracking reactor is further configured to provide a drag stream from a lower third of the slurry hydrocracking reactor, with the drag stream comprising a second hydrocarbon, mesophase material, and solid catalyst particles. The system also comprises first and second separation zones in fluid communication with the slurry hydrocracking reactor. The first separation zone is configured to fractionate the product effluent into a plurality of product streams. The second separation zone is configured to receive and separate the drag stream into a first separated stream and a recycle stream. The first separated stream comprises mesophase material and solid catalyst particles, and the recycle stream comprises the second hydrocarbon. The slurry hydrocracking reactor and second separation zone are further configured to deliver the recycle stream from the second separation zone to the slurry hydrocracking reactor. In this embodiment, an amount of mesophase material and catalyst particles in the recycle stream is reduced relative to an amount present in the drag stream.
BRIEF DESCRIPTION OF THE DRAWING
[0009] The various embodiments will hereinafter be described in conjunction with the following drawing FIGURE, wherein:
[0010] FIG. 1 is a block diagram illustrating a system and process for slurry hydrocracking in accordance with an exemplary embodiment.
DETAILED DESCRIPTION
[0011] The following detailed description is merely exemplary in nature and is not intended to limit the various embodiments or the application and uses thereof. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
[0012] Various embodiments contemplated herein relate to methods and systems for slurry hydrocracking (SHC) with reduced feed bypass. The exemplary embodiments taught herein generally involve passing a hydrocarbon feedstock through a SHC reaction zone in the presence of hydrogen and a suitable SHC catalyst to generate a SHC effluent stream. In some embodiments, the hydrocarbon feedstock comprises one or more of vacuum residue (VR), atmospheric residue (AR), deasphalted oil (DAO), and clarified slurry oil (CSO), vacuum gas oil (VGO) and coker gas oil (CGO). In some embodiments, the hydrocarbon feedstock is present in a heterogeneous slurry catalyst system in the SHC reactor, in which the catalyst is in the form of a solid particulate. The SHC reaction is carried out in the presence of hydrogen and under conditions suitable to crack at least a portion of the hydrocarbon feedstock to a lighter-boiling SHC distillate fraction that is recovered from the SHC effluent stream in a separation zone. The hydrogen may be provided as fresh hydrogen introduced to the SHC reactor with the hydrocarbon feed stream, and/or may include a hydrogen-rich stream recovered from the SHC effluent stream (e.g., as a gas stream recovered from a high pressure separator).
[0013] Representative conventional slurry hydrocracking methods are described, for example, in U.S. Pat. Nos. 5,755,955 and 5,474,977. In some methods, such as those described in U.S. Published Applications 2011/0303580 and 2014/0045679, recovered heavy vacuum gas oil (HVGO) may be at least partially recycled back to the slurry reactor for further conversion. However, the hydrocracking conditions used in these and other conventional slurry hydrocracking methods lead to accumulation of toluene insoluble material in the reactor. Toluene insoluble materials that accumulate in the reactor may include mesophase materials and catalyst solids. The build-up of toluene insoluble materials, and in particular mesophase materials, can lead to coking and feed bypass. Methods and systems described herein utilize a drag stream drawn from a lower portion of the reactor to continuously or intermittently remove toluene insoluble material, including mesophase material, from the reactor during reactor operation. As discussed in detail below, hydrocarbons captured in the drag stream are separated and returned to the reactor, thus reducing feed bypass and increasing conversion and yield.
[0014] Referring now to the representative flow scheme shown in FIG. 1 , in an embodiment, slurry 110 formed of a heavy hydrocarbon feedstock, hydrogen, and particulate catalyst is introduced into a SHC reaction zone 120 . As used herein, the term “zone” can refer to an area of an apparatus or system that includes one or more equipment items and/or one or more sub-zones. Equipment items can include reactors or reactor vessels, heaters, exchangers, pipes, pumps, compressors, controllers, etc. Additionally, an equipment item, such as a reactor, dryer, or vessel, can further include one or more zones or sub-zones.
[0015] The SHC reaction zone 120 comprises a SHC reactor, through which the slurry 110 is upwardly passed. The slurry 110 generally has a solid particulate content from about 0.1% to about 10% by weight. The solid particulate content generally comprises a compound of a catalytically active metal, or a metal in elemental form, either alone or supported on a refractory material such as an inorganic metal oxide (e.g., alumina, silica, zirconia, and mixtures thereof). As will be understood by those of skill in the art, other refractory materials, such as carbon, coal, clays, zeolite and non-zeolite molecular sieves, etc., may be used.
[0016] Catalytically active metals for use in hydroprocessing include those from Group IVB, Group VB, Group VIB, Group VIIB, or Group VII of the Periodic Table, which are incorporated into the slurry 110 in amounts effective for catalyzing the desired hydrotreating and/or hydrocracking reactions to provide, for example, lower boiling hydrocarbons. Specific representative metals include iron, nickel, molybdenum, vanadium, tungsten, cobalt, ruthenium, and mixtures thereof. The catalytically active metal may be present as a solid particulate in elemental form, or as an organic compound, or an inorganic compound such as a sulfide (e.g., iron sulfide) or other ionic compound. Metal or metal compound nanoaggregates may also be used to form the solid particulates.
[0017] In some embodiments it may be desired to form such metal compounds as solid particulates in situ from a catalyst precursor that decomposes or reacts in the hydroprocessing reaction zone environment, or in a pretreatment step, to form a desired, well-dispersed and catalytically active solid particulate. Thus, in some embodiments, the slurry 110 may not comprise a solid particulate catalyst at the time it is introduced into the SHC reaction zone 120 . Rather, the solid particulate catalyst may form in the slurry 110 , after introduction into the SHC reaction zone 120 and exposure to the hydroprocessing conditions therein.
[0018] In some embodiments, a catalyst precursor is a metal sulfate (e.g., iron sulfate monohydrate) that decomposes or reacts to form the catalytically active solid particulate (e.g., iron sulfide). Alternatively, precursors may include oil-soluble organometallic compounds containing the catalytically active metal of interest that thermally decompose to form the solid particulate (e.g., iron sulfide) having catalytic activity. Such compounds are generally highly dispersible in a heavy hydrocarbon feedstock and normally convert under pretreatment or hydroprocessing reaction zone conditions into the solid particulate that is contained in the slurry 110 . Other suitable precursors include metal oxides that may be converted to catalytically active (or more catalytically active) compounds such as metal sulfides. In a particular embodiment, a metal oxide containing mineral may be used as a precursor of a solid particulate comprising the catalytically active metal (e.g., iron sulfide) on an inorganic refractory metal oxide support (e.g., alumina). Bauxite represents a particular precursor in which conversion of iron oxide crystals contained in this mineral provides an iron sulfide catalyst as a solid particulate, whereby the iron sulfide after conversion is supported on the alumina that is predominantly present in the bauxite precursor.
[0019] The SHC reaction zone 120 includes a SHC reactor operating under conditions to affect the upgrading of the heavy hydrocarbon feedstock to provide a lower boiling component, namely an SHC distillate fraction, in an SHC effluent 130 exiting the SHC reaction zone 120 . For example, the SHC reactor may operate at a temperature from about 343° C. (about 650° F.) to about 538° C. (about 1000° F.). In another example, the SHC reactor may operate at a pressure from about 3.5 MPa (about 500 psig) to about 28 MPa (about 4000 psig). In a further example, a SHC reactor may operate at a space velocity from about 0.1 to about 30 volumes of heavy hydrocarbon feedstock per hour per volume of the SHC reactor.
[0020] In some embodiments, and as seen in FIG. 1 , upon exiting the SHC reaction zone 120 , the SHC effluent 130 is directed to a first separation zone 150 where a gas stream 160 (including hydrogen and/or light ends) is separated from a liquid stream 170 of the SHC effluent 130 . As used herein, the term “stream” can be a stream including various hydrocarbon molecules, such as straight-chain, branched, or cyclic alkanes, alkenes, alkadienes, and alkynes, and optionally other substances, such as gases, e.g., hydrogen, or impurities, such as heavy metals, and sulfur and nitrogen compounds. A stream may also include a mixture of aromatic and non-aromatic hydrocarbons. Moreover, hydrocarbon molecules may be abbreviated herein as C1, C2, C3, . . . Cn where “n” represents the number of carbon atoms in the one or more hydrocarbon molecules. In some embodiments, the SHC effluent 130 comprises one or more of naphtha, middle distillate, light vacuum gas oil, heavy vacuum gas oil, and pitch. As used herein, the term middle distillate is used to describe a hydrocarbon stream collected within a cutpoint range of about 204° C. (about 400° F.) to about 343° C. (650° F.). As such, the middle distillate may include hydrocarbons falling within the diesel or kerosene ranges. After separation of the SHC effluent 130 into gas stream 160 and liquid stream 170 , liquid stream 170 may comprise one or more of naphtha, middle distillate, light vacuum gas oil, heavy vacuum gas oil, and pitch.
[0021] The first separation zone 150 may use any suitable separation technique (e.g., high pressure separation, flash separation, vacuum distillation, etc.). In a particular embodiment, the first separation zone 150 comprises a high pressure separator. Although not shown in FIG. 1 , the first separation zone 150 may further include a sub-system for the recovery and recycling of hydrogen from the SHC effluent 130 into the slurry 110 .
[0022] In some embodiments, and as seen in FIG. 1 , liquid stream 170 is directed to a second separation zone 180 for fractionation into a low boiling stream 190 and a high boiling steam 200 . The second separation zone 180 may operate under conditions such that the low boiling stream 190 is separated from the high boiling stream 200 at a distillation endpoint above that of naphtha. For instance, the low boiling stream 190 may be recovered as a fraction up to a distillation endpoint temperature of about 204° C. (about 400° F.) to about 399° C. (about 750° F.), and such as about 260° C. (about 500° F.) to about 343° C. (about 650° F.), with the high boiling stream 200 comprising higher boiling compounds from the liquid stream 170 . Again, the second separation zone 180 may use any suitable separation technique (e.g., high pressure separation, flash separation, vacuum distillation, etc.). In a particular embodiment, the second separation zone 180 comprises a fractionation column. In some embodiments, the separation zone 180 is operated under conditions such that the lower boiling stream 190 comprises naphtha and one or more hydrocarbons from the middle distillate. In some embodiments, the separation zone 180 is operated under conditions such that the higher boiling stream 200 comprises one or more of one or more hydrocarbons from the middle distillate, light vacuum gas oil, heavy vacuum gas oil, and pitch. As will be understood, the compositions of the low boiling stream 190 and high boiling stream 200 can vary somewhat depending on the separation conditions, e.g., the distillation endpoint temperature, employed.
[0023] In some embodiments, and as seen in FIG. 1 , high boiling stream 200 is directed to a third separation zone 210 for separation into a light vacuum gas oil (LVGO) stream 220 , a heavy vacuum gas oil (HVGO) stream 230 , and a pitch stream 240 . Again, the third separation zone 210 may use any suitable separation technique (e.g., high pressure separation, flash separation, vacuum distillation, etc.). In a particular embodiment, the third separation zone 210 comprises a vacuum distillation column. In some embodiments, the LVGO stream 220 has a boiling point of about 343° C. (about 650° F.) to about 427° C. (about 800° F.). In some embodiments, the HVGO stream 230 has a boiling point of about 427° C. (about 800° F.) to about 524° C. (about 975° F.). In some embodiments, the pitch stream 240 has a boiling point of greater than about 480° C. (about 900° F.), such as greater than about 523° C. (about 975° F.).
[0024] In some embodiments, and as seen in FIG. 1 , the HVGO stream 230 is added, at least in part, to a recycle stream 250 for reintroduction into the SHC reaction zone 120 . In some embodiments, the recycle stream 250 is directly introduced into the SHC reactor. Alternatively, the recycle stream 250 may be admixed with slurry 110 prior to introduction into the SHC reaction zone 120 .
[0025] Low boiling stream 190 may optionally be separated into various sub-streams. In some embodiments, the low boiling stream 190 is fractionated, e.g., to yield naphtha and diesel fuel components having varying distillation endpoints. In some embodiments, such as in the exemplary embodiment seen in FIG. 1 , the low boiling stream 190 is directed to a fourth separation zone 260 , where the low boiling stream 190 is separated, e.g., by extractive distillation with a sulfolane solvent, into an aromatic stream 270 comprising aromatics such as benzene, toluene, and xylene, and a non-aromatic stream 280 comprising paraffinic hydrocarbons, particularly paraffinic hydrocarbons in the gasoline and diesel ranges.
[0026] In the methods and systems provided herein, a drag stream 140 is additionally directed from a SHC reactor in the SHC reaction zone 120 to a fifth separation zone 290 . In some embodiments, the SHC reactor is configured such that the drag stream 140 is drawn from the bottom third of the SHC reactor, such as from a point at or near the bottom of the SHC reactor. Configured as such, the drag stream 140 contains a large proportion of heavier materials that collect at the bottom of the reactor, such as mesophase material, solid catalyst particles, unreacted feed (including vacuum gas oil), and pitch. The fifth separation zone 290 comprises a separation system that allows for separation of fluids based on a density difference. In an exemplary embodiment, the fifth separation zone 290 comprises a vortex contactor/decanter or a settler/coalescer/precipitator. Vortex contactor/decanters are known in the art and utilize a centrifugal mechanism to separate fluids of different densities. Settler/coalescer/precipitator are also known in the art, and may be used to separate a liquid phase from a solid phase via precipitation and settling of solids entrained in a liquid phase. Thus, in the embodiments provided herein, the fifth separation zone 290 is used to separate the drag stream 140 into a recycle stream 300 comprising pitch and vacuum gas oil and a first separation stream 310 comprising catalyst solids and mesophase material. As a result, the amount of catalyst solids and mesophase material in recycle stream 300 is reduced relative to the amount of those materials in the drag stream 140 .
[0027] In some embodiments, the amount of catalyst solids and mesophase material in recycle stream 300 is less than about 50%, such as less than about 20%, such as less than about 10%, such as less than about 5%, such as less than about 1%, of the amount of catalyst solids and mesophase material in the drag stream 140 . That is, the amount of catalyst solids and mesophase materials in recycle stream 300 is about 0% to about 50%, such as about 0% to about 20%, such as about 0% to about 10%, such as about 0% to about 5%, such as about 0% to about 1%, of the amount of catalyst solids and mesophase material in the drag stream 140 . In some embodiments, the presence of catalyst solids and mesophase material in the recycle stream 300 is not avoided entirely. That is, in some embodiments, the amount of catalyst solids and mesophase material in recycle stream 300 is greater than 0%, but less than about 50%, such as less than about 20%, such as less than about 10%, such as less than about 5%, such as less than about 1%, of the amount of catalyst solids and mesophase material in the drag stream 140 .
[0028] Recycle stream 300 is then directed to the recycle stream 250 for reintroduction into the SHC reaction zone 120 . First separation stream 310 is captured for disposal or is optionally subjected to further processing for recapture/recycle of catalyst solids (not shown in FIG. 1 ). In embodiments where the first separation stream 310 is subjected to further processing for recapture/recycle of catalyst solids, the catalyst solids may be recovered or regenerated and optionally mixed with the fresh catalyst in a catalyst preparation unit (not shown).
[0029] In some embodiments, drag stream 140 is continuously pulled from the SHC reaction zone 120 . Alternatively, in some embodiments, drag stream 140 is intermittently pulled from the SHC reaction zone 120 . In either case, drag stream 140 may be pulled at intervals and amounts sufficient to stabilize and/or reduce the amount of toluene insoluble material, and in particular mesophase materials, present in the SHC reactor. In some embodiments, the drag stream 140 is pulled at intervals and amounts necessary to keep total toluene insoluble material present in the SHC reactor at less than about 25% by weight, such as less than about 10% by weight, such as less than about 5% by weight, of the contents of the SHC reactor. In some embodiments, the drag stream 140 is pulled at intervals and amounts necessary to keep the amount of mesophase materials present in the SHC reactor at less than about 25% by weight, such as less than about 10% by weight, such as less than about 5% by weight, of the contents of the SHC reactor. Prevention of the continued accumulation of toluene insoluble material (and in particular mesophase material) in the SHC reactor helps to avoid coking. This, along with the recycling of stream 300 , reduces coking, feed bypass, and improves system/process conversion and yield.
[0030] In some embodiments, an aliquot of the drag stream 140 may be collected prior to introduction of the drag stream 140 into the fifth separation zone 290 . The collected aliquot may be subjected to any of a variety of analytical techniques including but not limited to ash balance determination, elemental analysis, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), temperature programmed oxidation (TPO), nuclear magnetic resonance (NMR), mass spectroscopy (MS), two-dimensional gas chromatography (GC×GC), high-performance liquid chromatography (HPCL), x-ray diffraction (XRD), polarized light microscopy (PLM), and simulated distillation by gas chromatography (SIMDIS). This analysis of the drag stream 140 provides information to an operator regarding the contents of the SHC reactor. Information gained from this analysis may be used by the operator to determine appropriate flow rates (for continuous or intermittent schemes) and time of flow and time between flows (for intermittent schemes) for the drag stream 140 to achieve a desired level of total toluene insoluble or mesophase material present in the SHC reactor. As indicated above, in some embodiments, the flow rate, time of flow, and time between flows is determined such that the amount of total toluene insoluble or mesophase material present in the SHC reactor is less than about 25% by weight, such as less than about 10% by weight, such as less than about 5% by weight, of the contents of the SHC reactor.
[0031] Similarly, in some embodiments, an aliquot of the recycle stream 250 may be collected prior to reintroduction into the SHC reaction zone 120 . Again, the collected aliquot may be subjected to any of a variety of analytical analyses including but not limited to ash balance determination, elemental analysis, TEM, TGA, TPO, NMR, MS, GC×GC, HPLC, XRD, PLM, and SIMDIS. Analysis of the recycle stream 250 provides information to the operator regarding the composition of the recycle stream 250 and the SHC reaction zone 120 . Such information, alone or in combination with analytical results for the drag stream 140 (if collected), may facilitate adjustment of any of the above described reaction and separation conditions via one or more feedback control loop systems (not shown) to ensure robust and efficient operation.
[0032] While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims. | Methods and systems for slurry hydrocracking with reduced feed bypass and methods for modulating an amount of toluene insoluble material present in a slurry hydrocracking reactor are provided. An exemplary slurry hydrocracking method comprises the steps of: combining a hydrocarbon feed and a slurry hydrocracking catalyst or catalyst precursor to generate a slurry hydrocracking feed; introducing the slurry hydrocracking feed to a slurry hydrocracking reactor under hydrocracking conditions suitable to generate a first product stream; drawing a drag stream from the slurry hydrocracking reactor, the drag stream comprising a hydrocarbon, mesophase material, and solid catalyst particles; separating the drag stream into a first separated stream and a recycle stream, with the first separated stream comprising mesophase material and solid catalyst particles, and the recycle stream comprising the hydrocarbon; and directing the recycle stream into the slurry hydrocracking reactor. | 2 |
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